Datasets:

factored

/

pinecone_hackathon

like 0

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 14/863,055 filed on Sept. 23, 2015 that is a continuation of U.S. patent application Ser. No. 14/057,428 filed Oct. 18, 2013 and titled Method and Apparatus for Coviewing Video that claimed priority to both U.S. Provisional Application 61/715,553 filed Oct. 18, 2012 and U.S. Provisional Application 61/798,034 filed Mar. 15, 2013, the contents of which are all herein incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates generally to integrated telecommunications and multimedia systems and applications and, more particularly, to a method and apparatus for integrating provider video content with phone call communications in real time. [0004] 2. Description of the Prior Art [0005] Television (or “TV”) services which provide live video or recorded video content through channels such as over air broadcasts, cable TV systems, and satellite TV systems (“provider video content” or “TV style video content”) are well known. Over air broadcasts have been offered for decades, but typically only permit access to a few channels (five to ten). Cable TV and satellite systems have grown in popularity over the past few decades and typically offer a greater number of channels, in the range of tens or hundreds, as well as interactive services aimed at improving aspects of the user's viewing experience such as recording and playback and premium content for purchase. Recently, access to TV style video content has additionally been availed through the Internet, where such video can often be streamed for real time viewing and/or downloaded for subsequent viewing. On the Internet, many of the service enhancements which have been introduced by Cable TV and satellite systems are present in some form. In addition, due to the nature of the Internet and its delivery protocols, there remain opportunities to further enhance or supplement TV style video content provided over the Internet. [0006] Similarly, various telephone and voice communication services which facilitate remote audio or audio/video communications (“phone call” or “phone call communications”) over wired or wireless networks are well established. Traditional wired telephone networks date back more than a century and, more recently, wireless networks and Voice over Internet Protocol (“VoIP”) have introduced new communication protocols which provide increased functionality and often decrease costs. Notably, the rise in phone call communications through VoIP (and thus over the Internet) has largely coincided with the rise in the delivery of provider video content delivered over the Internet. A problem which still exists, however, is phone call communications and provider video content have remained largely separate services, unable to provide users with enhanced, integrated functionality. While users in remote locations can engage in a phone call and watch the same provider video content from the same source, the users cannot participate in an service wherein their phone call and provider video content viewing are integrated and synchronized together. Thus, there remains a need for a method and apparatus which could provide a coviewing system that would allow users in remote locations to engage in a phone call which was integrated with and occurring in conjunction with the viewing of the same provider video content. It would be helpful if such a coviewing system was structured to enable the synchronization of the video content being viewed by each user. It would be additionally desirable for such a coviewing system was structured to utilize smart echo cancellation which simultaneously accounted for audio from the provider video content and from the phone call. [0007] The Applicant's invention described herein provides for a system adapted to allow coviewing of provider video content such that phone call communications between a plurality of users has been integrated with a provider video content viewing session. The primary components of Applicant's method and apparatus for coviewing include a coviewing control system and a plurality of user interfaces which include audio and video inputs and audio and video outputs. When in operation, the method and apparatus for coviewing allows users in remote locations to engage in an phone call and provider video content viewing session simultaneously, whereby the phone call communications and provider video content have been integrated into a unified and synchronized interface to be broadcast by a output device simultaneously. As a result, many of the limitations imposed by the prior art are removed. SUMMARY OF THE INVENTION [0008] A method, apparatus and system to provide the ability for a user to make audio and/or audio-video calls simultaneously while watching (co-viewing) the same provider video (e.g. program, movie or sporting event). The calls may be to PSTN destinations or internet based destinations. Calls made or received may be bridged to other services such as Google Voice, Skype, Facebook and others. [0009] The invention incorporates multiple user interfaces. The interfaces include video displays. Each display may have a camera, whereby the camera may provide images of the respective user. Each video display includes a call transmitter and call receiver. The transmitter and receiver may be the same element. [0010] Video can be displayed as an overlay on a display such as Picture in Picture. TV program can be ‘squeezed-back’ on a display from a video call or other transmitted text. Video can also be placed on an ‘edge’ (top, bottom, left, right) of a display. Video can also be overlaid in windows such, so called ‘picture in picture’ or PIP. The invention includes the optional provision of the ability to synchronize playback of TV programming so both parties watch the same video ‘scene/play’ at the same time. The invention may also include intelligent echo cancellation that suppresses both normal audio echo as well as the audio associated with the TV program. [0011] Call setup may be performed through a Coviewing Control System (“CCS”). The CCS may be a dedicated system or leverage an existing telephony, conferencing or other system. Video from media may be routed directly or through some form of NAT traversal, or through the control system [0012] It is an object of this invention to provide a coviewing system which would allow users in remote locations to engage in an audio only or audio/video phone call which was integrated with and occurring in conjunction with the viewing of the same provider video content. [0013] It is another object of this invention to provide a coviewing system structured to enable the synchronization of the video content being viewed by each user. [0014] It is yet another object of this invention to provide a coviewing system structured to utilize smart echo cancellation which simultaneously accounted for audio from the provider video content and from the phone call. [0015] These and other objects will be apparent to one of skill in the art. BRIEF DESCRIPTION OF THE DRAWINGS [0016] FIG. 1 shows a general process flow according to the present invention. [0017] FIG. 2 is a block diagram of the components of a set top box adapted for coviewing and built in accordance with the present invention. [0018] FIG. 3 depicts the coviewing set up process according to the present invention. [0019] FIG. 4 depicts an exemplary user interface of a coviewing session according to the present invention. [0020] FIG. 5 depicts a user interface of a video content overlay coviewing session according to the present invention. [0021] FIG. 6 depicts a user interface of a video content squeeze back coviewing session according to the present invention. DETAILED DESCRIPTION OF THE INVENTION [0022] Referring now to the drawings and in particular FIG. 1 , a system overview of the operating components of a method and apparatus for coviewing is shown. A coviewing control system 10 is provided to perform server and administrator functions for a plurality of set top boxes 11 that perform client functions and provide user interfaces. The coviewing control system 10 is utilized to provide a call manager, which is implemented through a hardware and/or a software configuration. The call manager is used to provide phone call address information required for phone call setup and may work in conjunction with the processor of set top boxes 11 for setting up all calls, both incoming and outgoing, between set top boxes 11 or a set top box 11 and another device. It is contemplated that the call manager may be implemented through a dedicated system or by leveraging existing telephony or conferencing systems. [0023] The coviewing control system 10 and the set top boxes 11 are configured to maintain a network connection to the Internet 12 . In this manner, the coviewing control system 10 and the set top boxes 11 are adapted to communicate data in real time with each other as well as access data from or transmit data to any specific location on the Internet 12 . For example, the set top boxes 11 may utilize existing protocols to access provider video content through its connection to the Internet, whether at the direction of or independent of any action of the coviewing control system 10 . Similarly, set top boxes 11 may connect phone calls through a VoIP interface to publically switched telephone network destination or an Internet based destination. In this regard, it is contemplated that set top boxes 11 may be configured to handle incoming and outgoing phone calls or bridge such phone calls to services such as Google Voice, Skype, and Facebook. [0024] Referring now to FIG. 2 , the primary components of a set top box 11 built in accordance with the present invention are defined as interface components and processing components. The interface components include a networking interface 100 , an output interface 101 , a content input interface 102 , an audio input interface 103 and a video input interface 104 . The network interface 100 provides the network connection between the set top box 11 and the Internet so as to enable the set top box 11 to communicate data to locations on the world wide web. The network interface 100 is defined as a single connection which provides Internet access to a plurality of components in the set top box 11 in one embodiment. In alternate embodiments, the network interface 100 defines a plurality of connections which include wired connections, wireless connections or possibly wired and wireless connections. In other embodiments, connection protocols such as USB, Ethernet, WiFi, LTE, WiMax, 3G/4G/Cellular data may be utilized in addition or in the alternative by the network interface 100 . It is contemplated that other categories of media players/receives can be utilized in the alternative to, or in addition to, a set top box 11 . Alternative media players/receivers, such as game consoles, Internet media players/receives, and TVs configured to include media playing/receiving components may be configured in accordance with the present invention as described above. [0025] The output interface 101 is configured to provide signals which would allow a television or other audio/video display device to display and otherwise output audio and video signals relating the provider video content, phone call communications, or other content received from the Internet. In one embodiment, the output interface 101 is defined as a HDMI outlet. In alternate embodiments, audio and video outputs may be provided through the output interface 101 via a single or multiple connectors which may be wired, wireless, or a combination of wired and wireless. In other embodiments, connection protocols such as coaxial, USB, Ethernet, WiFi, WiMax, TOSLINK, SP/DIF, HDMI, component, and composite may be used by the output interface 101 to deliver audio and video signals to the desired audio/video display device. [0026] The content input interface 102 provides a supplementary input for provider video content which is not being received directly from the Internet 12 through the network interface 100 . The content input interface 102 utilizes one or more connection ports such as coaxial, component, composite, HDMI, SCART, TOSLINK, SP/DIF to receive input signals from providers of provider video content, such as Cable TV signals, satellite signals, analog or digital antenna inputs. It is contemplated that a plurality of one or more these connection ports may be provided. This signal can be used supplement a provider video content signal which is being received from the Internet 12 . In the alternative, the set top box 11 can directly use the broad video content signal from the content input interface 102 while supplementing that signal with data from the Internet 12 . [0027] The audio input interface 103 allows for audio from the area surrounding the set top box 11 to be captured and utilized in the operations of the set top box 11 . The audio input interface 103 defines an audio pick up device, which may be a single microphone or a microphone array to enable additional echo cancelling capability. In one embodiment, the audio pick up device is an internal component of the set top box 11 while in other embodiments, the audio pick up device is an external component connected to the set top box or a combination of internal and external components. [0028] The video input interface 104 captures video from the area surrounding the set top box 11 to be utilized in the operations of the set top box 11 . The video input interface 104 is defined in one embodiment by a internally mounted video camera. In other embodiments, the video camera may be externally disposed and connected to the set top box 11 via a connection, which may be either wired, or wireless, or a combination of both. [0029] The processing components include a central processing unit 105 , a local video encoder 106 , a local audio preamp 107 , a echo canceller 108 , a content decoder 109 , a transmission encoder 110 , an audio video decoder component 111 , an audio video combiner 112 , a combiner/mixer 113 , a call in filter 114 , coviewing audio video filter 115 , a graphics processor 116 , and a third party app processor 117 . In operation, the central processing unit 105 acts as a gatekeeper/taskmaster and regulates the system to ensure all interactions are taking place at the correct time and in the correct order. [0030] To handle the initial processing of locally generated inputs, the local video encoder 106 receives and encodes video signals from the video input interface 104 and then transmits the encoded local video signal to the audio video combiner 112 . In addition, the local audio preamp 107 is connected to the audio input interface 103 so as to receive audio signals from the audio input interface 103 , amplify them, and transmit the amplified signals to the echo canceller 108 . Furthermore, the content decoder 109 receives encoded provider video content from the content input interface 102 , decodes it, and transmits the decoded signals to the echo canceller 108 . [0031] To handle the initial processing of remotely generated inputs, the call in filter 114 filters out data relating to active, requested or pending phone calls in the signals received from the Internet through the networking interface 100 . This phone call data is then transmitted to the audio video decoder component 111 to be decoded and sent to the echo canceller 108 and the combiner/mixer 113 . The coviewing audio video filter 115 filters out data relating active requested, or pending coviewing sessions to enable it to be directed to the audio video decoder component 111 to be decoded and sent to the echo canceller 108 and the combiner/mixer 113 . The graphics processor 116 provides menu overlay information to the combiner/mixer 113 to enable the display of the same on the local video output. The third party app processor 117 enables the operation of third party apps which provide additional provider video content on the set top box 11 . The third part app processor 117 transmits received provider video content to the audio video decoder component 111 to be decoded and sent to the echo canceller 108 and the combiner/mixer 113 . It is contemplated that the audio video decoder component may be embodied as a single decoder or a plurality of audio/video decoders. [0032] Once the locally and remotely generate inputs are received and initially processed, the outputs of the set top box 11 are configured through the echo canceller 108 , the transmission encoder 110 , audio/video combiner 112 , and the combiner/mixer 113 . The echo canceller 108 receives audio data from a plurality of sources relating to noise which is being generated around the set top box 11 generates a signal which enables echo cancellation and unwanted noise suppression. When a point to point audio call, audio/visual call, or co-viewing call is made the echo canceller 108 takes the audio signal that would emit from the television or display device, or audio system that is outputting an audio signal coming through the set top box 11 , and generate a cancelling signal that would mix with the signal coming into the set top box 11 via the audio pick up device, thus cancelling the unwanted audio signal and preventing unwanted feedback. [0033] The transmission encoder 110 encodes data from the echo canceller 108 so as to prepare it to be transmitted to a desired networked target. The audio/video combiner 112 merges the audio and video outbound feeds together. This is accomplished by taking the audio signals from the echo canceller 108 and combining them with the video signal generated by the local video encoder 106 . In other embodiments, the transmission encoder 110 is not included and the audio and video feeds are transmitted as separate signals. [0034] The combiner/mixer 113 combines different sources of the audio/video signals which are to be provided to the television 118 or desired display device and routes the combined signal to the output interface 101 . It is contemplated that SMS, gaming audio/video, audio call, video call, video/audio call, interactive menu displays, co-viewing displays, and others may be provided to the output interface 101 by the combiner/mixer 113 . In some embodiments, the combiner/mixer 113 includes an encoder, while in other embodiments, an encoder is provided in the output interface 101 . [0035] Referring now to FIG. 3 , the process of initiating a coviewing session between two devices built in accordance with the present invention begins with a first user requesting a coviewing phone call connection with a second user at a specified or otherwise specific location (such as phone number, email address, or other unique identifier) on the first user's device interface. The request is transmitted to the coviewing control system, which locates the second user's through the provided unique identifier. The request is sent to the second user's device interface, and an option to accept or decline the request to provided to the second user's device interface. If the request is not accepted on the second user's device interface, the coviewing control system terminates the request and notifies the first user's device interface that the request has been unfulfilled. If the second user's device interface accepts the request, the coviewing control system begins provisioning the call request. Such provisioning enables a phone call signal which will be exchanged in real time by the respective user's device interfaces to be generated. [0036] During the provisioning of the phone call request, the coviewing control system notifies each user's device interface that a call is provision and causes the display a message advising that the call is connecting. Upon receiving this notification, each user's device interface transmits information relating to any provider video content currently being displayed by the respective user's device interface. This information typically includes the current program, the current channel and a time stamp indicating where in program duration wise the user's device interface is. The coviewing control system processes this information by generating a signal which synchronizes the provider video content being watched on the user's respective device interface. The synchronized provider video content signal is then integrated with the phone call signal to form an integrated coviewing signal. The coviewing signal is then transmitted to each user's device interface, which causes the user's device interface to each actuate a coviewing session. In actuating a coviewing session, the user's device interfaces begin to display or otherwise play the provider video content and phone call communications as directed by the coviewing control system and transmit capture phone call related audio and video information to the coviewing control system. [0037] In one embodiment, the coviewing control system merely integrates a pointer to a source of provider video content in the step of integrating provider video content and phone call. In such an embodiment, the provider video content is provided to each of the user's device interfaces directly from a provider or through a form of network address translation traversal. [0038] In one embodiment, the step of processing provider video content includes allowing the user's device interfaces to select a particular program or channel to watch during the coviewing session. [0039] Referring now to FIG. 4 , when a coviewing session is active, a user in a first location 400 and a user in a second location 401 can watch the same program and/or channel on a television screen 402 while having a video phone call, wherein the program and the video feed 403 a, 403 b from the other user are both visible on the user's respective television screen 402 . In embodiments where video call is not provided for, users can still utilize coviewing to participate in a phone call while watching synchronized provider video content in remote locations. [0040] Referring now to FIG. 5 , in one embodiment, the video 500 from the phone call communication of a coviewing session is displayed as an overlay on top of the provider video content 501 being displayed on the display device 502 . In some embodiments, the coviewing session provides in addition to the remotely generated phone call communication video 500 the locally generated video 503 . [0041] Referring now to FIG. 6 , in another embodiment, during a coviewing session, the provider video content video 600 is squeezed back on the display device 601 to provide a space in which the video 602 from the phone call communication of a coviewing session is displayed. It is contemplated that the video can be squeezed back on the edge of a display device so as to provide space on an opposing edge or squeezed back to a more centrally located position on the display device to provide space along the perimeter of the provider video content 600 . In this embodiment, the coviewing session may again provides in addition to the remotely generated phone call communication video 602 the locally generated video 603 . [0042] In one embodiment, the provider video content and/or user interfaces and/or video from phone call communications may be selectively displayed on a selected device or a plurality of selected devices. For example, a coviewing system may enable the video from provider video content to be displayed on a first display device, such as a mobile electronic device (tablet, smartphone, etc.), while the video from the phone call communication of a coviewing session is displayed on a second display device, such as a TV. Similarly, a coviewing system may enable menus and other user interface elements on a mobile device and video on a TV. Further, a coviewing system may enable all video and user interfaces to be displayed on a mobile device. [0043] The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art.

A method, apparatus, and system to provide the ability for a user to make audio and/or audio-video phone calls simultaneously while watching (co-viewing) provider video content in remote locations. A control system is provided to set up call, direct provider video content, and provide for the phone calls and video content to be delivered and then synchronized. The phone calls may be routed by the control system to PSTN destinations or Internet based destinations and calls made or received may be bridged to other Internet based sources. The provider video content may be provided directly from its source or routed through NAT traversal or through the control system.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electro-luminescent display (ELD) and a method of manufacturing thereof. More specifically, the present invention relates to an active ELD including an organic luminescent layer. 2. Discussion of the Related Art An ELD is a luminescent device that emits light when electrons and holes that are injected into a luminescent layer recombine. The emission of light by the recombination of electrons and holes eliminates the need for a back-light in the ELD. Thus, it is easy to manufacture a very thin panel using an ELD. Further, the ELD has the added advantage of low power consumption. Additionally, an organic ELD, having a light-emitting layer with an organic electro-luminescent (EL) substance, is characterized by a low driving voltage, high light-emitting efficiency, and low process temperature. However, organic EL substances are vulnerable to moisture so that the patterns are defined by a method that prevents the organic EL substance from contacting moisture directly, unlike conventional photolithography. In an active ELD, a plurality of pixels are defined by providing a plurality of scanning lines that cross with a plurality of signal lines, and also such that a power supply line is arranged in the same direction as the signal line in each of the pixels. Each pixel includes a storage capacitor, an EL portion, and at least one switching device such as a thin film transistor (TFT). When the pixel includes two TFTs, an excitation signal for the EL portion is distinguished from the scanning signal. The EL portion is selected by a logic TFT which is the first TFT, and the excitation signal for the EL portion is controlled by the second TFT. The storage capacitor then maintains the excitation power in the EL portion of the selected cell. FIGS. 1A to FIGS. 1D illustrate a method of manufacturing an ELD according to a related art method. Referring to FIG. 1A, polysilicon is deposited on an insulating substrate 11 having a switching part and a pixel part, via a chemical vapor deposition (CVD) process. Then an active layer 13 is formed by patterning the polysilicon via a photolithography process. An insulating substance such as silicon oxide, silicon nitride, or other similar substances are then deposited on the insulating substrate 11 to cover the active layer 13 . Next, an electrically-conductive substance is deposited on the insulating substance. Then, a gate insulating layer 15 and a gate electrode 17 is formed by sequentially patterning the electrically-conductive substance and the insulating substance so that they remain on the middle portion of the active layer 13 . Note that a scanning line (not shown in the drawing) that is connected to the gate electrode 17 may be provided as soon as the gate electrode 17 is formed. A source region 19 and a drain region 21 are then formed by heavily doping the exposed portions of the active layer 13 with either n type or p type impurities with the gate electrode 17 functioning as a mask. Note that the middle portion of the active layer 13 , which is not doped with impurities, becomes a channel region. Referring to FIG. 1B, a first insulating interlayer 23 is then provided and covers the active layer 13 , the gate electrode 17 , and the scanning line by depositing an insulating substance such as silicon oxide, silicon nitride, or other similar substances on the insulating substrate 11 . Next, the first insulating interlayer 23 is patterned to expose the source region 19 and the drain region 21 , and a source electrode 25 and a drain electrode 27 are connected electrically with the exposed source region 19 and exposed drain region 21 , respectively, by depositing and then patterning a known conductive substance. Thus, a TFT that functions as a switching device is manufactured. Note that a signal line (not shown in the drawing) may be defined on the insulating interlayer 23 at the same time the source electrode 25 and the drain electrode 27 are provided. Referring to FIG. 1C, a second insulating interlayer 29 is provided and covers the source electrode 25 and the drain electrode 27 and the signal line by depositing silicon oxide or silicon nitride on the first insulating interlayer 23 . A contact hole 30 exposes the drain electrode 27 and is provided by patterning the second insulating interlayer 29 . Next, a transparent conductive substance is deposited so as to contact the exposed portion of the drain electrode 27 through the contact hole 30 that is provided in the second insulating interlayer 29 . Then, an anode electrode 31 is formed by patterning via a photolithography process the transparent conductive substance so that the anode electrode 31 remains in the pixel portion of the second insulating interlayer 29 . Note that the anode electrode 31 is electrically connected to the drain electrode 27 , and is isolated electrically from other anode electrodes in adjacent pixel cells. Referring to FIG. 1D, a passivation layer 33 covers the anode electrode 31 by the deposition of silicon oxide or silicon nitride on the second insulating interlayer 29 . Alternatively, the passivation layer 33 may be formed with an organic substance such as BCB (benzocyclobutene), SOG(spin-on glass), and other similar substances. Note that the passivation layer 33 made of an organic substance may be relatively thick in order to provide an even surface. Next, the passivation layer 33 is patterned via a photolithography process, including a dry etching process, so as to expose the anode electrode 31 . An organic EL layer 35 , which emits a predetermined color such as red, blue, or green, is provided on the passivation layer 33 by an evaporation process. Note that the organic EL layer 35 just contacts the anode electrode 31 and the exposed pixel portion. Next, a cathode electrode 37 , which functions as a common electrode, is disposed on the organic EL layer 35 . As mentioned in the above description, the ELD of the related art carries out the switching operation by selecting a TFT that has an n-type channel in a certain pixel, which has a predetermined signal line (not shown in the drawing) crossing with a predetermined scanning line (not shown in the drawing), such that a ‘high’ signal is applied to the predetermined scanning line while a ‘high’ signal is applied to the predetermined signal line. Thus, the selected TFT turns on and transfers the signal of the predetermined signal line to the drain electrode by which holes are injected into the organic EL layer via the anode electrode and electrons are injected into the organic EL layer via the cathode electrode. Thus, the pixel achieves light-emission through the recombination of electrons and holes. Unfortunately, in the structure and method of the related art, the exposed portion of the anode electrode is easily damaged by the collision of the ions when dry-etching the passivation layer for exposing the anode electrode. Further, contaminant particles, albeit a small amount, remain on the exposed portion of the anode electrode after the etching process. Thus, the damage to the anode electrode caused by the collision of the ions during the etching process and the remaining contaminant particles on the anode electrode after the etching process creates a barrier interface between the anode electrode and the EL layer that hinders the efficient transport of charge carriers such as holes. Therefore, the expected life span, brightness, and efficiency of the ELD suffers greatly from the structure and method of the related art. SUMMARY OF THE INVENTION To overcome the problems described above, preferred embodiments of the present invention provide an ELD and a method of manufacturing the ELD that improves the expected life span, brightness, and efficiency of the ELD by preventing the generation of a barrier interface between the anode electrode and the organic EL layer, which hinders the transport of charge carriers such as holes across the interface. A preferred embodiment of the present invention includes a substrate having a pixel portion and a switching portion, an active layer on the switching portion of the substrate including a source region on a first end of the active layer, a drain region on a second end of the active layer, and a channel region at a middle portion of the active layer and in between the drain region and the source region, a gate insulating layer on the channel region, a gate electrode on the gate insulating layer such that the gate insulating layer is disposed between the gate electrode and the active layer, an insulating interlayer on the substrate covering the gate electrode, wherein the insulating interlayer does not substantially cover the source and drain regions so that substantial portions of the source and drain regions are exposed, a source electrode and a drain electrode in contact electrically with the exposed portions of the source and drain regions, respectively, a passivation layer on the insulating interlayer, wherein the passivation layer covers the source electrode and the drain electrode, a connect hole in the passivation layer, wherein the connect hole substantially exposes the drain electrode, an anode electrode on the passivation layer, wherein the anode electrode is in contact electrically with the drain electrode through the connect hole, an organic electro-luminescent layer on the passivation layer and covering the anode electrode, and a cathode electrode on the organic electro-luminescent layer. Another preferred embodiment of the present invention includes a substrate, a plurality of layers on the substrate, wherein the plurality of layers includes source and drain electrodes, a passivation layer on the substrate and covering the source and drain electrodes, a connect hole in the passivation layer and exposing the drain electrode, an anode electrode on the passivation layer and in contact with the drain electrode, and an organic electro-luminescent layer on the passivation layer covering the anode electrode. In another preferred embodiment of the present invention, a method of manufacturing an ELD includes the steps of providing a substrate, separating the substrate into a switching portion and a pixel portion, forming an active layer on the switching portion, forming a gate insulating layer and a gate electrode on a middle portion of the active layer, forming a source region and a drain region on exposed portions of the active layer by doping the exposed portions of the active layer heavily with impurities while using the gate electrode as a mask, disposing an insulating interlayer on the substrate and covering the active layer and the gate electrode, patterning the insulating interlayer so as to expose the source and drain regions, forming a source electrode and a drain electrode that is in contact with the exposed portions of the source and drain regions, forming a passivation layer on the insulating interlayer, defining a contact hole in the passivation layer for exposing the drain electrode, defining an anode electrode on the passivation layer, and covering the drain electrode so as to be in contact with the drain electrode, forming an organic electro-luminescent layer on the passivation layer and covering the anode electrode, defining a cathode electrode on the organic electro-luminescent layer. Therefore, preferred embodiments of the present invention provide an ELD structure and method of manufacturing an ELD which achieve the advantages of increasing the expected lifespan, increasing the brightness, and improving the efficiency of the ELD by preventing the generation of a barrier interface between the anode electrode and a electro-luminescence layer by eliminating a subsidiary layer between the anode electrode and the electro-luminescence layer thereby removing the need to etch the subsidiary layer for allowing the anode electrode and the electro-luminescence layer to have excellent contact therebetween. Other features, elements and advantages of the present invention will be described in detail below with reference to preferred embodiments of the present invention and the attached drawings. BRIEF DESCRIPTION OF THE ATTACHED DRAWINGS The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus do not limit the present invention and wherein: FIGS. 1A to FIGS. 1D illustrate a method of manufacturing an ELD according to a related art; FIG. 2A is a general diagram of an ELD according to a preferred embodiment of the invention; FIG. 2B is a cross-sectional view of a portion of an ELD according to a preferred embodiment of the present invention; and FIG. 2A is a general diagram of an ELD and FIG. 2B is a cross-sectional view of an ELD according to a preferred embodiment of the present invention. As shown in FIG. 2A, the ELD includes a plurality of pixels each pixel 100 including: a switching TFT (Qs) having a gate electrode connected to a gate line 120 and a source electrode connected to a data line 140 ; a driving TFT (Qd) having a gate electrode connected to a drain of the switching TFT, a source electrode connected to a power line Vdd, and a drain electrode connected to an electro-luminescent diode Ed; and a capacitor C connected between the gate electrode and the source electrode of the driving TFT. Referring to FIG. 2B, each pixel of the ELD according to the present invention includes an active layer 43 preferably made of polysilicon and preferably having a thickness of about 500 Å to about 1000 Å disposed on a predetermined portion of a switching portion of an insulating substrate 41 made of a transparent substance such as quartz, glass, or other similar substance, and having a switching portion and a pixel portion. A source region 49 and a drain region 51 , which are doped heavily with either n-type impurities such as P or, As, or p-type impurities such as B, are provided at both ends of the active layer 43 . The approximate central portion of the active layer 43 is not doped with impurities and defines a channel region. A gate insulating layer 45 , which is preferably made of an insulating substance such as silicon oxide, silicon nitride and other similar substances and preferably about 800 Å to 1500 Å thick, is provided on the channel region of the active layer 43 . A gate electrode 47 , which is made of an electrically-conductive substance such as Al, Al alloy or other similar substances having a low resistance and preferably about 4000 Å to 5000 Å thick, is provided on the gate insulating layer 45 . FIG. 3A to FIG. 3D illustrate a method of manufacturing an ELD according to another preferred embodiment of the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 2 is a cross-sectional view of an ELD according to a preferred embodiment of the present invention. Referring to FIG. 2, an ELD includes an active layer 43 preferably made of polysilicon and preferably having a thickness of about 500 Å to about 1000 Å disposed on a predetermined portion of a switching portion of an insulating substrate 41 made of a transparent substance such as quartz, glass, or other similar substance, and having a switching portion and a pixel portion. A source region 49 and a drain region 51 , which are doped heavily with either n-type impurities such as P or, As, or p-type impurities such as B, are provided at both ends of the active layer 43 . The approximate central portion of the active layer 43 is not doped with impurities and defines a channel region. A gate insulating layer 45 , which is preferably made of an insulating substance such as silicon oxide, silicon nitride and other similar substances and preferably about 800 Å to 1500 Å thick, is provided on the channel region of the active layer 43 . A gate electrode 47 , which is made of an electrically-conductive substance such as Al, Al alloy or other similar substances having a low resistance and preferably about 4000 Å to 5000 Å thick, is provided on the gate insulating layer 45 . In the present preferred embodiment, the gate electrode 47 may have two layers such that a refractory metal such as Cr, Mo, Ti, Ta, or other similar metals are deposited on a low resistance metal such as Al, Al alloy or other similar metals. Also, the gate electrode 47 may be formed as soon as a scanning line (not shown in the drawing), which is connected to the gate electrode 47 , is provided. Next, an insulating interlayer 53 that exposes the source region 49 and the drain region 51 are defined on the insulating substrate 41 and covers the gate electrode 47 . The insulating interlayer 53 which is preferably about 4000 Å to 5000 Å thick is defined preferably by depositing an insulator such as silicon oxide, silicon nitride and other similar substances. Then, a source electrode 55 and a drain electrode 57 , which are preferably in contact electrically with the exposed portions of the source region 49 and the drain regions 51 , respectively, are provided on the insulating interlayer 53 . The source electrode 55 and the drain electrode 57 are preferably made of a single layer of conductive metal such as Al, Al alloy, or other similar substances having a low resistance. Note that a signal line (not shown in the drawing) that is connected to the source electrode 55 may be formed on the insulating interlayer 53 at the same time that the source electrode 55 is formed. A passivation layer 59 that covers the source electrode 55 and the signal line, but which exposes the drain electrode 57 through a hole 60 , is provided on the insulating interlayer 53 . The passivation layer 59 is provided preferably by depositing silicon oxide or silicon nitride and having a thickness preferably about 4000 Å to about 5000 Å, and then coating the deposited silicon oxide or silicon nitride with an organic substance such as BCB (Benzocyclobutene), SOG(Spin On Glass), or other similar substances, wherein the coating is preferably about 1 μm to 3 μm thick. Note that in preferred embodiments of the present invention, the degradation from steps in the layers is less since the passivation layer 59 is relatively thick and includes the organic substance to provide a smooth surface thereon. Next, an anode electrode 61 that is in contact electrically with the exposed portion of the drain electrode 57 through the hole 60 is provided on the passivation layer 59 of the pixel portion. Note that the anode electrode 61 , which is defined preferably by depositing a transparent conductive substance such as an ITO (Indium Tin Oxide), TO(TiN Oxide), or other similar substances and is preferably about 1000 to 2000 Å 0 thick, is isolated electrically from the other anode electrodes in the neighboring pixels. An organic EL layer 63 is then provided on the passivation layer 59 and preferably covers the anode electrode 61 . Note that the organic EL layer 63 is preferably about 1000 to 2000 Å thick, and is defined by depositing a substance that emits a light having a red, blue, or green color as electrons and holes recombine. Then, a cathode electrode 65 , which is preferably used as a common electrode connected to ground, is defined on the organic EL layer 63 . The cathode electrode 65 is defined preferably by depositing a metal having a low work function, such as Al, Al alloy, Ka, Na, Ca, Li, or other similar substances, to make it easy for electrons to be injected into the organic EL layer 63 , and is preferably about 1000 Å to about 3000 Å thick. Note that the organic EL layer 63 also includes a hole injecting and transporting region that is in contact with the anode electrode 61 , and an electron injecting and transporting region that is in contact with the cathode electrode 65 , and a luminescent layer that emits light. The hole or electron injecting/transporting regions may be provided with a single substance or with multiple substances. The light emission occurs in the hole and electron injecting/transporting region as the transported electrons and holes recombine in the luminescent layer. Note that in preferred embodiments of the present invention, the organic EL layer 63 is defined on the entire anode electrode 61 and is in contact with the entire anode electrode without a subsidiary layer (e.g., layer 33 in FIG. 1) located in between. Therefore, the surface of the anode electrode 61 is not damaged since an etching process is not necessary for the organic EL layer 63 to contact the anode electrode 61 . Further, the etch remainders or the contaminant particles that are contained in etchant do not exist on the anode electrode 61 . Therefore, the expected life span, brightness, and efficiency of the ELD is improved dramatically as charge carriers such as holes are transported with ease at the interface between the anode electrode 61 and the organic EL layer 63 . FIG. 3A to FIG. 3D illustrate a method of manufacturing an ELD according to a preferred embodiment of the present invention. Referring to FIG. 3A, an active layer 43 is provided preferably by depositing a polysilicon layer preferably about 500 Å to 1000 Å thick on an insulating substrate 41 having a switching portion and a pixel portion preferably via a CVD process and then patterning the polysilicon layer preferably via a photolithography process. The insulating substrate 41 is preferably made of a transparent substance such as quartz, glass, or other similar substances. An insulating substance preferably about 800 Å to 1500 Å thick such as silicon oxide, silicon nitride, and other similar substances is deposited on the insulating substrate 41 preferably via a CVD process and preferably covers the active layer 43 . Next, a conductive metal preferably about 4000 Å to 5000 Å thick, and preferably having low resistivity, such as Al, Al alloy, or other similar metals is deposited on the insulating substance preferably via a sputtering method. Next, a gate electrode 47 and a gate insulating layer 45 are then provided by patterning, preferably via a photolithography process, the conductive metal and the insulating substance so that they remain on the middle portion of the active layer 43 . In the above-described method, the gate electrode 47 may preferably have two layers such that a refractory metal, which is made of Cr, Mo, Ti, Ta, or other similar substances, is disposed preferably on a low resistance metal such as Al, Al alloy or other similar substances. Note that the gate electrode 47 may be provided as soon as a scanning line (not shown in the drawing) that is connected to the gate electrode 47 is formed. A source region 49 and a drain region 51 , both of which are preferably doped heavily with either n-type impurities such as P, As, or p-type impurities such as B, are defined preferably at the two exposed ends of the active layer 43 . The middle portion of the active layer 43 , which is not doped with impurities, defines a channel region of the active layer 43 . Referring to FIG. 3B, an insulating interlayer 53 is provided on the insulating substrate 41 and preferably covers the gate electrode 47 , the active layer 43 , and the scanning line by dispersing an insulating substance preferably about 4000 Å to 5000 Å thick such as silicon oxide, silicon nitride and other similar substances. The insulating interlayer 53 is then preferably patterned so as to expose the source region 49 and the drain region 51 . Next, a source electrode 55 and a drain electrode 57 , which are in contact electrically with the exposed portions of the source region 49 and the drain region 51 , respectively, are defined on the insulating interlayer 53 . The source electrode 55 and the drain electrode 57 are formed preferably by depositing and then patterning the conductive metal having a low resistance such as Al, Al alloy, or other similar substances preferably via a sputtering method and then preferably via a photolithography process, respectively. The resultant structure is a thin film transistor that functions as a switching device. Note that the source electrode 55 and the drain electrode 57 are preferably made from a single layer of a conductive metal such as Al, Al alloy, or other similar substances having a low resistance. Also, a signal line (not shown in the drawing) is connected to the source electrode 55 , and may be defined on the insulating interlayer 53 at the same time as the source electrode 55 and the drain electrode 57 are formed. FIGS. 3A to FIGS. 3D illustrate a method of manufacturing an ELD having the configuration as shown in FIG. 2 according to a preferred embodiment of the present invention. Referring to FIG. 3A, an active layer 43 is provided preferably by depositing a polysilicon layer preferably having a thickness of about 500 Å to about 1000 Å on an insulating substrate 41 having a switching portion and a pixel portion preferably via a CVD process and then patterning the polysilicon layer preferably via a photolithography process. The insulating substrate 41 is preferably made of a transparent substance such as quartz, glass, or other similar substances. An insulating substance, preferably having a thickness of about 800 Å to about 1500 Å, such as silicon oxide, silicon nitride, and other similar substances is deposited on the insulating substrate 41 preferably via a CVD process and preferably covers the active layer 43 . Next, a conductive metal preferably having a thickness of about 4000 Å to about 5000 Å, and preferably having low resistivity, such as Al, Al alloy, or other similar metals is deposited on the insulating substance preferably via a sputtering method. Next, a gate electrode 47 and a gate insulating layer 45 are then provided by patterning, preferably via a photolithography process, the conductive metal and the insulating substance so that they remain on a portion (e.g., middle portion) of the active layer 43 . In the above-described method, the gate electrode 47 may preferably have two layers such that a refractory metal, which is made of Cr, Mo, Ti, Ta, or other similar substances, is disposed preferably on a low resistance metal such as Al, Al alloy or other similar substances. Note that the gate electrode 47 may be provided as soon as a scanning line (not shown in the drawing) that is connected to the gate electrode 47 is formed. A source region 49 and a drain region 51 , both of which are preferably doped heavily with either n-type impurities such as P, As, or p-type impurities such as B, are defined preferably at the two exposed ends of the active layer 43 . The middle portion of the active layer 43 , which is not doped with impurities, defines a channel region of the active layer 43 . Referring to FIG. 3D, an organic EL layer 63 is provided and preferably covers the anode electrode 61 . Next, a cathode electrode 65 , which functions as a common electrode, is provided on the organic EL layer 63 . The cathode electrode 65 is preferably about 1000 Å to 3000 Å thick, and is provided by depositing a metal with a low work function such as Al, Al alloy, Ka, Na, Ca, Li, or other similar metals for easier injection of electrons into the organic EL layer 63 . The organic EL layer 63 is preferably about 1000 Å to 2000 Å thick, and is provided by depositing a substance that emits light as electrons and holes recombine, the light being either red, blue, or green. The organic EL layer 63 preferably includes a hole injecting and transporting region that is in contact with the anode electrode 61 , an electron injecting and transporting region that is in contact with the cathode electrode 65 , and a luminescent layer that emits light. Note that the hole and electron injecting/transporting regions may be defined with a single substance or with multiple substances. Light-emission occurs in the hole and electron injecting/transporting regions as the transported electrons and holes recombine in the luminescent layer. Note that in the ELD of preferred embodiments of the present invention, the organic EL layer 63 is provided on the anode electrode 61 and in contact with the anode electrode without a subsidiary layer disposed in between. Thus, the surface of the anode electrode 61 is not damaged because an etching step is not performed to allow the organic EL layer 63 to be in contact with the anode electrode 61 . Further, etch remainders or contaminant particles contained in the etch gases do not accumulate on the surface of the anode electrode 61 . Accordingly, there does not exist a barrier interface between the anode electrode and organic EL layer which would hinder the transport of carriers such as holes. Therefore, the expected life span, the brightness, and the efficiency of the ELD are greatly improved as the holes are transported through the interface between the anode electrode and organic EL layer with ease. While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the present invention.

An electro-luminescent display and a method of manufacturing thereof prevents the formation of a barrier interface between the anode electrode and the electro-luminescent layer by placing the electro-luminescent layer directly on the anode electrode so that there is no need to etch a subsidiary layer so that the electro-luminescent layer and the anode electrode have excellent electrical contact. The elimination of this etching step prevents damage to the anode electrode caused by collision of ions with the anode electrode during the etching process. Further, etch remainders or contaminant particles that exist in the etchant gas are prevented from accumulating on the anode electrode. Thus, the charge carriers of the anode are easily transported across the interface between the anode electrode and the electro-luminescent layer so as to greatly improve the expected life span, the brightness, and the efficiency of the electro-luminescent display.

TECHNICAL FIELD [0001] The present invention relates to an assembly of forming elements which together define in a papermaking apparatus a discontinuous supporting surface for a papermaking suspension to permit drainage and micro-turbulence to be accurately controlled, and to the papermaking apparatus per se. BACKGROUND OF THE INVENTION [0002] In the papermaking industry, various forming elements are deployed to promote the drainage of water from paper stock in its transformation from a papermaking suspension (or slurry) of fibres, water and chemicals (eg fillers) into a self-supporting web of cellulose fibres commonly referred to as a sheet (ie a sheet of paper or board). De-watering takes place in the forming area at the “wet end” of a papermaking apparatus, a typical one of which is illustrated schematically by way of example in FIG. 1 . Thus in FIG. 1 , parallel papermaking wires 1 (or mesh or a belt) move in direction A and are supported from beneath by discrete forming elements which include forming boards 2 , spaced apart foils 3 and low vacuum blades 4 . Suction box covers 5 together with Uhle box covers 8 constitute dewatering elements. [0003] Crucial to the formation of the sheet of paper (or board) in the forming area is the drainage of the papermaking suspension and the micro-turbulence generated in the papermaking suspension which serves to eliminate agglomeration thereby enhancing the uniformity of the papermaking suspension. The harmonic pitch of the papermaking apparatus is the spacing on the paper table of the forming board, forming foils and gravity foils which together determine the natural harmonics of the wet end of the papermaking apparatus and which is established at the time that the papermaking apparatus is designed to give the desired drainage and micro-turbulence. It can be a disadvantage of conventional papermaking apparatus that the design is specified in accordance with certain grades of paper (or board) and certain types or quality of pulp. [0004] Referring again to FIG. 1 , the papermaking suspension is ejected from a flow box or head box (not shown) onto the papermaking wire 1 . Commonly the forming board 2 which is a solid unitary element may do little more than help to direct the papermaking suspension flow onto the moving papermaking wires 1 prior to de-watering. However the forming board 2 may be provided with grooves or slots to generate micro-turbulence. GB-A-2190932 discloses a solid forming board (known commercially as the TURBOFORM™ board) in the surface of which one or more transverse, open-ended slots are provided. The depth of the slots may be varied by an insert to achieve the requisite degree of micro-turbulence in the papermaking suspension whilst permitting limited drainage. However the TURBOFORM™ board is able to take little or no account of the natural harmonic pitch of a papermaking apparatus. Moreover the TURBOFORM™ board is generally of little use in a slow speed papermaking apparatus. SUMMARY OF THE INVENTION [0005] The present invention seeks to improve the versatility of a papermaking apparatus by introducing into the forming area an assembly of forming elements which together define a discontinuous supporting surface for the papermaking suspension. More particularly, the present invention relates to an assembly of forming elements which takes account of and enhances the natural harmonic pitch of the papermaking apparatus to accurately control in the forming area the drainage of and micro-turbulence in the papermaking suspension thereby satisfying a demand from customers for improved paper quality (eg improved fibre and fines dispersal throughout the sheet). [0006] Thus viewed from one aspect the present invention provides an assembly of forming elements including: a primary blade capable of being positioned adjacent one or more supply means at the wet end of a papermaking apparatus; a first secondary support blade coupled to a leading face of the primary blade by a first drainage deckle; and optionally n consecutive additional secondary support blades and n consecutive additional drainage deckles, wherein a trailing face of the first additional secondary support blade is coupled to a leading face of the first secondary support blade by the first additional drainage deckle and a trailing face of the second to n th additional secondary support blades is coupled respectively to a leading face of the first to n-1 th additional secondary support blades by the second to n th additional drainage deckle respectively, wherein n is an integer of one or more, whereby the upper surface of the primary blade, the first secondary support blade, the first drainage deckle, the n additional drainage deckles and the n additional secondary support blades together define a discontinuous surface for supporting a papermaking suspension being carried by a carrier from the wet end to an output end of the papermaking apparatus. [0010] Viewed from a further aspect the present invention provides a papermaking apparatus capable of making a sheet of paper (or board) from a papermaking suspension, said apparatus comprising: [0011] one or more supply means for introducing the papermaking suspension into a wet end of the apparatus; [0012] a carrier for carrying the papermaking suspension from the wet end to an output end of the apparatus; and [0013] an assembly of forming elements which include: a primary blade positioned adjacent the one or more supply means; a first secondary support blade coupled to a leading face of the primary blade by a first drainage deckle; and optionally n consecutive additional secondary support blades and n consecutive additional drainage deckles, wherein a trailing face of the first additional secondary support blade is coupled to a leading face of the first secondary support blade by the first additional drainage deckle and a trailing face of the second to n th additional secondary support blades is coupled respectively to a leading face of the first to n-1 th additional secondary support blades by the second to n th additional drainage deckle respectively, wherein n is an integer of one or more, whereby the upper surface of the primary blade, the first secondary support blade, the first drainage deckle, the n additional drainage deckles and the n additional secondary support blades together define a discontinuous surface for supporting the papermaking suspension. [0017] It will be apparent that the assembly of forming elements largely making up the forming area of the papermaking apparatus of the invention may be advantageously extended to any desired length to achieve the requisite formation characteristics simply by adding additional secondary support blades and additional drainage deckles (ie by increasing n). Moreover, in sharp contrast to conventional rigid forming boards, the forming elements of the papermaking apparatus of the invention may be assembled into the papermaking apparatus quite straightforwardly to the desired length. To exemplify its improved versatility, the papermaking apparatus may be used with a broader range of paper (or board) grades (eg varying in weight) than has hitherto been possible irrespective of the carrier speed. [0018] The upper surfaces of the forming elements together present a discontinuous supporting surface (paper table) to the papermaking suspension. This discontinuous surface serves intrinsically to generate micro-turbulence in the papermaking suspension. For this purpose, the profile, thickness and/or relative positioning of the primary blade, the first secondary support blade, the first drainage deckle, the n additional drainage deckles and the n additional secondary support blades may be varied to suit the requirements of the papermaking process. Typically the discontinuous supporting surface is irregularly discontinuous. For example the discontinuous supporting surface may be stepped (eg irregularly stepped). [0019] Preferably the upper surfaces of the primary blade, the first secondary support blade and the n consecutive additional secondary support blades are substantially coplanar at a first height and the upper surface of at least one (preferably each) of the first drainage deckle and n consecutive additional drainage deckles is at a height different from the first height. Particularly preferably the upper surfaces of the primary blade, the first secondary support blade and the n consecutive additional secondary support blades are substantially coplanar at a first height and the upper surface of each of the first drainage deckle and n consecutive additional drainage deckles is at a height different from the first height whereby to define a discontinuous surface which is stepped. More preferably the upper surfaces of the first drainage deckle and n consecutive additional drainage deckles are substantially coplanar at heights different from each other and from the first height whereby to define a discontinuous surface which is substantially irregularly stepped. Alternatively (if desired) the upper surfaces of the first drainage deckle and n consecutive additional drainage deckles are substantially coplanar at a common height different from the first height whereby to define a discontinuous surface which is substantially regularly stepped [0020] Alternatively or additionally the upper surfaces of at least one of (preferably each of) the first drainage deckle and n consecutive additional drainage deckles is angled (eg angled at a height different from the first height). Typically the upper surface is angled downwardly from trailing to leading edges of the upper surface. The difference between the first and second height and any degree of angling may be judiciously chosen to generate the desired micro-turbulence into the papermaking suspension. For example, each of the first drainage deckle and n consecutive additional drainage deckles may be angled at a different angle to fine tune the micro-turbulence. Typically the angle is in the range 1-4° from the horizontal. [0021] Additionally or alternatively at least one (preferably more than one eg each) of the first drainage deckle and n consecutive additional drainage deckles generates micro-turbulence in the papermaking suspension by extrinsic means. In a preferred embodiment, at least one (preferably more than one eg each) of the first drainage deckle and n additional drainage deckles is adapted to transmit a means for generating micro-turbulence in the papermaking suspension. Preferably the means for generating micro-turbulence is sourced externally and may be a physical means or electromagnetic radiation. For example, the means for generating micro-turbulence may be pulses of fluid (eg gas or liquid such as water) or vibrations (eg sonic vibrations). [0022] Preferably the upper surface of at least one (preferably more than one eg each) of the first drainage deckle and n consecutive additional drainage deckles comprises a groove adapted to transmit fluid (eg water) onto its upper surface. Typically the groove is a closed end groove (ie a groove extending downwardly from and transversely along the upper surface remote from its opposing edges). The transverse end walls of the groove may be curved (eg semicircular). [0023] Preferably the groove is adapted to transmit pulses of fluid (eg water) onto its upper surface. Preferably to an end wall of at least one (preferably more than one eg each) of the first drainage deckle and n consecutive additional drainage deckles extends a transverse slot (eg a transverse substantially circular slot) outwardly from a transverse end wall of the groove. Particularly preferably to a first and second end wall of at least one (preferably more than one eg all) of the first drainage deckle and n consecutive additional drainage deckles extends respectively a first and a second transverse slot (eg a transverse substantially circular slot) outwardly from a first and second transverse end wall of the groove respectively. The or each transverse slot is in fluid communication with the groove and therefore with the upper surface so that pulses of fluid (eg water) may be transmitted therethrough onto the upper surface. The depth of the groove, the nature of the means for generating micro-turbulence and the manner in which the means for generating micro-turbulence is applied may be judiciously chosen to refine the micro-turbulence generated intrinsically in the papermaking suspension (eg by dampening or amplifying the micro-turbulence imparted by the natural harmonic pitch of the forming elements) which in turn assists fibre formation and dispersal of fines throughout the sheet (ie improves sheet quality). [0024] The first drainage deckle and n additional drainage deckles may couple the leading and trailing faces of a first and second consecutive forming element in any convenient manner. Preferably the leading and trailing faces of the drainage deckle engage the first and second consecutive forming elements through male and female portions (eg interlocking male and female portions) of any convenient coupling arrangement. The male and female portions may be a tongue and groove or a dovetail-type arrangement. Preferably the male and female portions are a tongue and groove. More preferably the trailing face of the drainage deckle bears a tongue adapted to engage a complementarily shaped groove on the leading face of the first forming element and the leading face of the drainage deckle bears a groove adapted to be engaged by a complementarily shaped tongue on the trailing face of the second forming element. [0025] The thickness and/or profile of the first drainage deckle and n additional drainage deckles may be different but are preferably largely the same and may (in practice) be judiciously chosen to accurately control drainage of and micro-turbulence in the papermaking suspension as discussed above. Typically the trailing and leading faces of the drainage deckle are substantially perpendicular to the upper and lower surfaces. The upper edge of the leading face typically comprises a shoulder and the upper edge of the trailing face is chamfered. [0026] The primary blade may be positioned immediately after the one or more supply means and support the carrier substantially at the point where (in use) the papermaking suspension flows onto the carrier. Typically the trailing face of the primary blade tapers downwardly and forwardly and the leading face is substantially non-tapered (ie substantially perpendicular to the upper and lower surfaces) and incorporates the male or (preferably) female portion (eg a groove) of any convenient male/female coupling arrangement (eg a tongue and groove). The upper edge of the leading face typically comprises a shoulder and the upper edge of the trailing face is chamfered. The primary blade is normally (but not necessarily) the same thickness as each of the first and n additional secondary support blades. The lower face may be adapted to enable the primary blade to be mounted on the forming box (eg by incorporating the male or (preferably) female portion of any convenient male/female coupling arrangement such as a dovetail type arrangement or (preferably) T-bars/T-slots). [0027] The carrier may be a wire (or wires), belt, mesh or other arrangement driven between the wet end and the output end in a conventional manner. The carrier may be at least partly composed of fabric, metal or plastic which may be woven or otherwise manipulated. [0028] The one or more supply means may be head boxes or flow boxes as desired. [0029] The first secondary support blade and n optional additional secondary support blades (which may be different but are preferably the same) support the carrier largely in the area where sheet formation takes place (the forming area). Typically the trailing face of the first secondary support blade and n optional additional secondary support blades is substantially perpendicular to the upper and lower surfaces and incorporates the female or (preferably) male portion (eg a tongue) of any convenient male/female coupling arrangement (eg a tongue and groove). The upper edge of the leading face typically comprises a shoulder and the upper edge of the trailing face is chamfered. The first secondary support blade and n optional additional secondary support blades are normally (but not necessarily) the same thickness as the primary blade. The lower face may be adapted to enable the first secondary support blade and n optional additional secondary support blades to be mounted on the forming box (eg by incorporating the male or (preferably) female portion of any convenient male/female coupling arrangement such as a dovetail type arrangement or (preferably) T-bars/T-slots). [0030] By substituting the forming elements of a conventional papermaking apparatus with the assembly as hereinbefore defined, the natural harmonic pitch of the conventional papermaking apparatus is advantageously enhanced in a controlled manner. [0031] Viewed from a yet further aspect the present invention provides a method for constructing a papermaking apparatus as hereinbefore defined comprising: [0032] (a) obtaining a conventional papermaking apparatus comprising one or more conventional forming elements in the forming area; [0033] (b) substituting at least one (preferably all) of the one or more conventional forming elements with an assembly of forming elements which include: a primary blade positioned adjacent the one or more supply means; a first secondary support blade coupled to a leading face of the primary blade by a first drainage deckle; and optionally n consecutive additional secondary support blades and n consecutive additional drainage deckles, wherein a trailing face of the first additional secondary support blade is coupled to a leading face of the first secondary support blade by the first additional drainage deckle and a trailing face of the second to n th additional secondary support blades is coupled respectively to a leading face of the first to n-1 th additional secondary support blades by the second to n th additional drainage deckle respectively, wherein n is an integer of one or more, [0037] whereby the upper surface of the primary blade, the first secondary support blade, the first drainage deckle, the n additional drainage deckles and the n additional secondary support blades together define a discontinuous surface for supporting the papermaking suspension. [0038] In accordance with an embodiment of the method of the invention, the conventional forming elements include a conventional forming board and the primary blade of the assembly functionally replaces the conventional forming board. The primary blade may be (but is not necessarily) the same width as the forming board and is generally the same length. [0039] In accordance with an embodiment of the method of the invention, the conventional forming elements include one or more forming foils and the first and n optional additional secondary support blades functionally replace the one or more forming foils. In this embodiment, n will be determined by the user in accordance with the demands of the application. [0040] In a preferred embodiment of the method of the invention, the forming elements are mounted individually on existing T-bars of the forming box of the conventional papermaking apparatus thereby retaining the harmonic pitch of the conventional papermaking apparatus but refining it accordingly. In contrast, the rather more cumbersome rigid TURBOFORM™ board is mounted in the conventional papermaking apparatus on at least two T-bars simultaneously. [0041] Viewed from an even yet further aspect the present invention provides a kit of parts comprising one or more of the forming elements selected from the group consisting of a primary blade as hereinbefore defined, a first secondary support blade as hereinbefore defined, n additional secondary support blades as hereinbefore defined and n consecutive additional drainage deckles as hereinbefore defined, said one or more of the forming elements capable of being assembled into an assembly as hereinbefore defined. [0042] The present invention will now be described in a non-limitative sense with reference to the accompanying Figures in which: BRIEF DESCRIPTION OF THE DRAWINGS [0043] FIG. 1 is a side perspective view illustrating the present invention; [0044] FIG. 2 illustrates schematically an isolated side view of a first embodiment of the assembly of forming elements of the invention; [0045] FIG. 3 illustrates schematically an isolated side view of a second embodiment of the assembly of forming elements of the invention; [0046] FIG. 4 illustrates a primary blade; [0047] FIG. 5 illustrates a secondary blade; [0048] FIG. 6 illustrates a drainage deckle of the first embodiment; [0049] FIG. 7 illustrates a drainage deckle of the second embodiment; [0050] FIG. 8 illustrates a conventional papermaking apparatus in use; and [0051] FIG. 9 illustrates a papermaking apparatus of the invention in use. DETAILED DESCRIPTION OF THE INVENTION [0052] FIG. 2 illustrates schematically an isolated side view of the assembly of forming elements 1 of a first embodiment of a papermaking apparatus of the invention. The assembly of forming elements 1 includes a primary blade 2 positioned immediately after the one or more supply means (not shown), a first secondary support blade 3 , first and second consecutive additional secondary support blades 4 a and 4 b , a first drainage deckle 5 and first and second additional drainage deckles 6 a , 6 b . The assembly of forming elements 1 defines a discontinuous upper surface for supporting the papermaking suspension carried by a papermaking wire 7 . [0053] The primary blade 2 is illustrated alone in FIG. 4 . A trailing face 42 a of the primary blade 2 tapers downwardly and forwardly. A leading face 41 a of the primary blade 2 is perpendicular to the upper and lower surfaces and is provided with a shoulder 42 at its upper edge. The lower surface incorporates T-shaped slots 49 a , 49 b which engage T-shaped bars on the forming box. [0054] The first secondary support blade 3 and first and second additional secondary support blades 4 a , 4 b are the same and are illustrated alone in FIG. 5 . A trailing face 2 la of the first secondary support blade 3 and first and second additional secondary support blades 4 a , 4 b is perpendicular to the upper and lower surfaces and is provided with a chamfer 500 at its upper edge. A leading face 21 b of the first secondary support blade 3 and first and second additional secondary support blades 4 a , 4 b is perpendicular to the upper and lower surfaces and is provided with a shoulder 501 at its upper edge. The first secondary support blade 3 and first and second additional secondary support blades 4 a , 4 b are the same thickness as the primary blade 2 . The lower surface incorporates a T-shaped slot 59 a which engages a T-shaped bar on the forming box. [0055] The upper surfaces of the primary blade 2 , the first secondary support blade 3 and the first and second consecutive additional secondary support blades 4 a and 4 b are substantially coplanar at a first height. [0056] The first drainage deckle 5 , first additional drainage deckle 6 a and second additional drainage deckle 6 b are essentially (but not precisely) the same and are illustrated alone in perspective view in FIG. 6 . The upper surfaces 65 of each of the first drainage deckle 5 , first additional drainage deckle 6 a and second additional drainage deckle 6 b are at heights different from the common height of the primary blade 2 , the first secondary blade 3 and the first and second additional secondary support blade 4 a , 4 b whereby to define a discontinuous surface which is substantially irregularly stepped. Moreover the upper surface 65 of each of the first drainage deckle 5 , first additional drainage deckle 6 a and second additional drainage deckle 6 b is angled at a different angle in the range 1-4°. The difference between the heights creates voids 11 a , 11 b and 11 c . The voids 11 a , 11 b and 11 c and the variable angling of the upper surfaces 65 of the first drainage deckle 5 , first additional drainage deckle 6 a and second additional drainage deckle 6 b contribute to the generation of micro-turbulence in the papermaking suspension. [0057] The trailing face 21 a of the first additional secondary support blade 4 a is coupled to the leading face 21 b of the first secondary support blade 3 by the first additional drainage deckle 6 a and the trailing face 21 a of the second additional secondary support blade 4 b is coupled to the leading face 21 b of the first additional secondary support blade 4 a by the second additional drainage deckle 6 b . The trailing face 1 a of the first secondary support blade 3 is coupled to the leading face 41 a of the primary blade 2 by the first drainage deckle 5 . [0058] The first drainage deckle 5 and first and second additional drainage deckles 6 a , 6 b couple the leading and trailing faces of the forming elements by a tongue and groove arrangement. [0059] For example, a trailing face 71 a of the drainage deckle 5 bears a tongue 72 adapted to engage a complementarily shaped groove 73 on the leading face 41 a of the primary blade 2 and the leading face 74 a of the drainage deckle 5 bears a groove 75 adapted to be engaged by a complementarily shaped tongue 76 on the trailing edge of the first secondary support blade 3 . [0060] FIG. 3 illustrates schematically an isolated side view of the assembly of forming elements 31 of a second embodiment of a papermaking apparatus of the invention which is particularly useful in slow speed papermaking apparatus. The assembly 31 is largely the same as the assembly 1 described for the first embodiment hereinbefore but has a different first drainage deckle 35 and first and second additional drainage deckles 36 a , 36 b (see FIG. 7 ). Each of the first drainage deckle 35 and first and second additional drainage deckles 36 a , 36 b is adapted to introduce micro-turbulence into the papermaking suspension by extrinsic means. Each of the first drainage deckle 35 and first and second additional drainage deckles 36 a , 36 b comprises a closed end groove 301 extending downwardly from and transversely along the upper surface 300 . To an end wall 302 of each of the first drainage deckle 35 and first and second additional drainage deckles 36 a , 36 b extends a first transverse circular slot 303 outwardly from the groove 301 . To an opposing end wall 304 of each of the first drainage deckle 35 and first and second additional drainage deckles 36 a , 36 b extends a second transverse circular slot 305 outwardly from the groove 301 . Through the slots 303 , 305 may be transmitted pulses of water which reach the upper surface 300 through the groove 301 and generate micro-turbulence in the papermaking suspension. [0061] To illustrate the general improvements in the generation of micro-turbulence, FIGS. 8 and 9 illustrate respectively a papermaking suspension during dewatering in a conventional papermaking apparatus and a papermaking apparatus of the invention. [0062] It will be understood that this disclosure, in many respects, is only illustrative. Changes may be made in details, particularly in matters of shape, size, material, and arrangement of parts without exceeding the scope of the invention. Accordingly, the scope of the invention is as defined in the language of the appended claims.

The present invention relates to an assembly of forming elements which together define in a papermaking apparatus a discontinuous supporting surface for a papermaking suspension to permit drainage and micro-turbulence to be accurately controlled, and to the papermaking apparatus per se.

BACKGROUND [0001] 1. Field [0002] The present disclosure relates generally to microprocessor-based drivers for light emitting diode (LED) bulbs, and more specifically to microprocessor-based drivers for LED bulbs that enable the LED bulb to emit light at different levels of brightness. [0003] 2. Description of Related Art [0004] Conventional incandescent light bulbs that have three lighting levels (“three-way light bulbs”) include two filaments; in the minimum illumination setting a low wattage filament is energized, in the medium illumination setting a medium wattage filament is energized, in the high illumination setting both filaments are energized. The illumination setting is selected by energizing a first input connected to the low wattage filament, energizing a second input connected to the medium filament, or energizing both the first and second inputs. [0005] The conventional incandescent three-way light bulb has three electrical contacts, hot1, hot2, and neutral. A switch, contained in the lamp base, connects terminal hot1 to mains power (e.g., a 120 VAC 60 Hz signal in the United States) in the low power case, connects hot2 to mains power in the medium power case, and connects both hot1 and hot2 to mains power in the high power case. Terminal hot1 is connected to the low wattage filament and terminal hot2 is connected to the medium wattage filament. Thus, either or both filaments may be selected to provide three levels of illumination. [0006] One method for reproducing the same functionality of the incandescent three-way light bulb in an LED bulb is to have two sets of LEDs with each set having its own driver connected to a different hot input. However, this requires having two driver circuits, which increases costs and increases space requirements that are limited when implementing LED bulbs in typical form factors of standard light bulbs. Therefore, it is desirable to connect multiple hot inputs to a single driver circuit. However, this requires the driver circuit to sense which of two terminals are energized and set the supply current of the LEDs accordingly. This could be done by inserting a component in series with each input and sensing the voltage drop across this series component. While this technique may work in principle, it would introduce power losses in the series component. Additionally, this technique requires many additional parts to amplify and detect the voltage. These parts increase the cost of the LED bulb, and are therefore undesirable. BRIEF SUMMARY [0007] A light emitting diode (LED) bulb is described. The LED bulb comprises a shell, a plurality of LEDs within the shell, and a driver circuit. The driver circuit is configured to operate the plurality of LEDs at a plurality of brightness levels. The driver circuit comprises a first input configured to receive alternating current (AC), a second input configured to receive AC, a neutral input, a converter circuit connected to the plurality of LEDs, a first rectifier circuit, a second rectifier circuit, one or more detector circuits, and a signal processing circuit. The first rectifier circuit is connected to the first input and the neutral input. The first rectifier circuit is configured to rectify the AC received at the first input into direct current (DC). The second rectifier circuit is connected to the second input and the neutral input. The second rectifier circuit is configured to rectify the AC received at the second input into DC. The one or more detector circuits are connected to the first rectifier circuit and the second rectifier circuit. The signal processing circuit has a first processor input and a second processor input. The signal processing circuit is connected to the one or more detector circuits. The signal processing circuit is configured to produce a chop signal with a duty cycle. The duty cycle is based on whether the first input is hot and whether the second input is hot. The converter circuit powers the plurality of LEDs at a driving current. The driving current is based on the chop signal. DESCRIPTION OF THE FIGURES [0008] FIG. 1 depicts an exemplary LED bulb that may be used with the exemplary LED driver circuit for brightness control. [0009] FIG. 2 depicts a block schematic of an exemplary LED driver circuit for brightness control. [0010] FIG. 3A depicts an exemplary graph of the output of an SMPS power converter in an exemplary LED driver circuit. [0011] FIG. 3B depicts an exemplary graph of Vchop in an exemplary LED driver circuit. [0012] FIG. 3C depicts an exemplary graph of the output of an AND gate in an exemplary LED driver circuit. [0013] FIG. 4 depicts an exemplary circuit topology for an LED driver circuit. DETAILED DESCRIPTION [0014] The following description is presented to enable a person of ordinary skill in the art to make and use the various embodiments. Descriptions of specific devices, techniques, and applications are provided only as examples. Various modifications to the examples described herein will be readily apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other examples and applications without departing from the spirit and scope of the various embodiments. Thus, the various embodiments are not intended to be limited to the examples described herein and shown, but are to be accorded the scope consistent with the claims. [0015] An exemplary LED driver circuit that can drive one or more LEDs at three different brightness levels by driving the LEDs at three different currents is described below. The driver circuit uses a microcontroller to sense the input line voltages from a three-way switch. This reduces the number of required parts. Accordingly, the driver circuit is suitable for use in an LED bulb. [0016] FIG. 1 depicts an exemplary LED bulb 100 . The LED bulb maybe liquid-filled. LED bulb 100 includes a base 110 and a shell 101 encasing the various components of LED bulb 100 . The shell 101 is attached to the base 110 forming an enclosed volume. An array of LEDs 103 are mounted to support structures 107 and are disposed within the enclosed volume. The enclosed volume may be filled with a thermally conductive liquid 111 . [0017] For convenience, all examples provided in the present disclosure describe and show LED bulb 100 being a standard A-type form factor bulb. However, as mentioned above, it should be appreciated that the present disclosure may be applied to LED bulbs having any shape, such as a tubular bulb, globe-shaped bulb, or the like. [0018] Shell 101 may be made from any transparent or translucent material such as plastic, glass, polycarbonate, or the like. The shell 101 may be clear or frosted to disperse light produced by the LEDs. Shell 101 has a geometric center and an apex located at the top of the LED bulb 100 as it is drawn in FIG. 1 . [0019] As noted above, light bulbs typically conform to a standard form factor, which allows bulb interchangeability between different lighting fixtures and appliances. Accordingly, in the present exemplary embodiment, LED bulb 100 includes connector base 115 for connecting the bulb to a lighting fixture. In one example, connector base 115 may be a conventional light bulb base having threads 117 for insertion into a conventional light socket. However, as noted above, it should be appreciated that connector base 115 may be any type of connector for mounting LED bulb 100 or coupling to a power source. For example, connector base may provide mounting via a screw-in base, a dual-prong connector, a standard two- or three-prong wall outlet plug, bayonet base, Edison Screw base, single pin base, multiple pin base, recessed base, flanged base, grooved base, side base, or the like. [0020] In some embodiments, LED bulb 100 may use 6 W or more of electrical power to produce light equivalent to a 40 W incandescent bulb. In some embodiments, LED bulb 100 may use 18 W or more to produce light equivalent to or greater than a 75 W incandescent bulb. Depending on the efficiency of the LED bulb 100 , between 4 W and 16 W of heat energy may be produced when the LED bulb 100 is illuminated. [0021] The LED bulb 100 includes several components for dissipating the heat generated by LEDs 103 . For example, as shown in FIG. 1 , LED bulb 100 includes one or more support structures 107 for holding LEDs 103 . Support structures 107 may be made of any thermally conductive material, such as aluminum, copper, brass, magnesium, zinc, or the like. In some embodiments, the support structures are made of a composite laminate material. Since support structures 107 are formed of a thermally conductive material, heat generated by LEDs 103 may be conductively transferred to support structures 107 and passed to other component of the LED bulb 100 and the surrounding environment. Thus, support structures 107 may act as a heat-sink or heat-spreader for LEDs 103 . [0022] Support structures 107 are attached to bulb base 110 allowing the heat generated by LEDs 103 to be conducted to other portions of LED bulb 100 . Support structures 107 and bulb base 110 may be formed as one piece or multiple pieces. The bulb base 110 may also be made of a thermally conductive material and attached to support structures 107 so that heat generated by LED 103 is conducted into the bulb base 110 in an efficient manner. Bulb base 110 is also attached to shell 101 . Bulb base 110 can also thermally conduct with shell 101 . [0023] Bulb base 110 also includes one or more components that provide the structural features for mounting bulb shell 101 and support structure 107 . Components of the bulb base 110 include, for example, sealing gaskets, flanges, rings, adaptors, or the like. Bulb base 110 also includes a connector base 115 for connecting the bulb to a power source or lighting fixture. Bulb base 110 can also include one or more die-cast parts. [0024] LED bulb 100 may be filled with thermally conductive liquid 111 for transferring heat generated by LEDs 103 to shell 101 . The thermally conductive liquid 111 fills the enclosed volume defined between shell 101 and bulb base 110 , allowing the thermally conductive liquid 111 to thermally conduct with both the shell 101 and the bulb base 110 . In some embodiments, thermally conductive liquid 111 is in direct contact with LEDs 103 . [0025] Thermally conductive liquid 111 may be any thermally conductive liquid, mineral oil, silicone oil, glycols (PAGs), fluorocarbons, or other material capable of flowing. It may be desirable to have the liquid chosen be a non-corrosive dielectric. Selecting such a liquid can reduce the likelihood that the liquid will cause electrical shorts and reduce damage done to the components of LED bulb 100 . [0026] LED bulb 100 may include a mechanism to allow for thermal expansion of thermally conductive liquid 111 contained in the LED bulb 100 . In the present exemplary embodiment, the mechanism is a bladder 120 . The outside surface of the bladder 120 is in contact with the thermally conductive liquid 111 . [0027] The LED bulb 100 further contains the driver circuit. Connector base 115 may include two hot contacts and a neutral contact. In exemplary LED bulb 100 , the driver circuit may be driver circuit 200 discussed below with respect to FIG. 2 and is substantially contained within connector base 115 . In this context, substantially contained means that the majority of the driver circuit is within connector base 115 , but portions of driver circuit components may be protruding from connector base 115 . For example, portions of the driver circuit may protrude above connector base 115 into bulb base 110 or shell 101 . Similarly, the driver circuit may be substantially contained within bulb base 110 . [0028] The driver circuit may be integrated onto a single printed circuit board, which fits within the LED bulb 100 . In one case, the driver circuit is integrated on a single printed circuit board and fits substantially within the bulb base or connector base of the LED bulb 100 . [0029] FIG. 2 depicts a block schematic of an exemplary LED driver circuit 200 for brightness control. Driver circuit 200 may be used in an LED bulb to power one or more LEDs 228 . Driver circuit 200 takes as input an input line voltage (e.g., 120 VAC, 60 Hz in the U.S.) from a three-way switch connected to input 202 , which includes hot input 202 a, hot input 202 b , and neutral input 202 c. At output 226 , driver circuit 200 outputs a current suitable for powering the one or more LEDs 228 . The three-way switch will energize hot input 202 a only, hot input 202 b only, or both hot inputs 202 a and 202 b at the same time. The one or more LEDs 228 will not be illuminated when the three-way switch does not energize any of hot inputs 202 a and 202 b. [0030] As will be described in more detail below, driver circuit 200 includes rectifier circuits 204 and 206 , detector circuits 208 and 210 , signal processing circuit 212 , diodes 214 , SMPS power converter circuit 216 , AND gate 218 , FET switch 220 , and converter circuit 222 . Not all elements of driver circuit 200 are required. For example, some or all of the diodes 214 may be omitted. [0031] The rectifier circuits 204 and 206 are configured to convert the alternating currents (AC) from the hot inputs 202 a and 202 b into direct currents (DC). For example, the rectifier circuits 204 and 206 may each be a full-wave bridge rectifier circuit. Alternatively, a single rectifier circuit may be configured to convert the AC from the hot inputs 202 a and 202 b into DC. When hot input 202 a is energized, the rectifier circuit 204 outputs a continuous stream of half-sine waves, which are detected by detector circuit 208 . Similarly, when hot input 202 b is energized, the rectifier circuit 206 outputs a continuous stream of half-sine waves, which are detected by detector circuit 210 . [0032] The detector circuits 208 and 210 detect the state of the input lines as being above or below a threshold. In this example, detector circuits 208 and 210 are voltage level detector circuits that detect whether the voltage at their input is above or below a determined threshold voltage value. The detector circuits 208 and 210 output a high voltage signal when their inputs are above the determined threshold and output a low voltage signal when their outputs are below the determined threshold. The high voltage signal is relatively higher voltage than the low voltage signal. In one example, detector circuits 208 and 210 may each include a voltage splitter and a clamp. The voltage splitter portion of each detector circuit 208 and 210 reduces the voltage to a level useable by the signal processing circuit 212 . The clamp portion of each detector circuit serves to fix the signal to a determined DC value, such as for a high voltage signal or a low voltage signal. Additionally, the detector circuits 208 and 210 may optionally include a comparator for providing a further level of accuracy. [0033] The outputs of the detector circuits 208 and 210 are output to signal processing circuit 212 . For example, the signal processing circuit may be a microprocessor, a state machine, a customized integrated circuit, or other logic circuit. The signal processing circuit 212 processes the input signals received from the detector circuits 208 and 210 to determine whether only hot input 202 a, only hot input 202 b, or both hot inputs 202 a and 202 b at the same time are energized. The signal processing circuit 212 may have two inputs, called a first processor input and a second processor input. For each of the first processor input and the second processor input, the signal processing circuit 212 determines whether a received processor signal at the processor input is active (on) or inactive (off). For each of the first processor input and the second processor input, the received signal is time-integrated to protect against noisy conditions. A processor signal into the signal processing circuit 212 is determined to be active by the signal processing circuit 212 when the ratio between the duration of a high voltage signal and the duration of a low voltage signal is above an active threshold value. Similarly, a processor signal into the signal processing circuit 212 is determined to be inactive by the signal processing circuit 212 when the ratio between the duration of a high voltage signal and the duration of a low voltage signal is below the active threshold. The status of the processor signal at each processor input is indicative of the status of a corresponding hot input. For example, when the processor signal at the first processor input is active, it indicates that hot input 202 a is energized. When the processor signal at the second processor input is active, it indicates that hot input 202 b is energized. [0034] Various methods may be employed by the signal processing circuit 212 to determine the status of a processor signal. For example, a processor signal at a processor input may be determined to be active by the signal processing circuit 212 when the duration of a continuous high voltage signal exceeds a determined time. In another example, a processor signal at a processor input may be determined to be active by the signal processing circuit 212 when the duration of a continuous low voltage signal is less than a determined time. In another example, a processor signal at a processor input may be determined to be inactive by the signal processing circuit 212 when the duration of a continuous low voltage signal exceeds a determined time. In yet another example, a processor signal at a processor input may be determined to be inactive by the signal processing circuit 212 when the duration of a continuous high voltage signal is less than a determined time. Based on one or more of these durations at each processor input, the signal processing circuit 212 determines whether each of the hot inputs 202 a and 202 b are energized. [0035] The signal processing circuit 212 is configured performing time integration on the processor signals at a processor input of the signal processing circuit 212 . Time integration helps avoid incorrect results due to noisy conditions. It is advantageous to perform the time integration over two or more cycles before the signal processing circuit 212 makes a determination about the state of the hot inputs 202 a and 202 b. [0036] Based on the determination of the states of the hot inputs 202 a and 202 b, the signal processing circuit 212 outputs a chopped signal, named Vchop. For example: when only hot input 202 a is energized, the duty cycle of the output signal of the signal processing circuit 212 , Vchop, is set to 25% (low illumination of LEDs); when only hot input 202 b is energized, the duty cycle of the output signal of the signal processing circuit 212 , Vchop, is set to 50% (medium illumination of LEDs); when both hot inputs 202 a and 202 b are both energized, the duty cycle of the output signal of the signal processing circuit 212 , Vchop, is set to 100% (high illumination of LEDs). [0037] The signal processing circuit 212 sets the duty cycle of Vchop by performing pulse width modulation (PWM). Thus, at a high level, the signal processing circuit 212 selects between various duty cycles based on whether only hot input 202 a, only hot input 202 b, or both hot inputs 202 a and 202 b at the same time are energized. Accordingly, the signal output by the signal processing circuit 212 is pulse width modulated with a duty cycle based on the inputs 202 a and 202 b. As discussed above, this pulse width modulated signal produced by the signal processing circuit 212 is called Vchop. [0038] It is advantageous for Vchop to have a PWM switching frequency that is at least 10 times higher than the frequency of the combined output at diode connection 224 . Assuming, for example, an input line frequency of 60 Hz at the hot inputs 202 a and 202 b, the combined output at diode connection 224 is a 120 Hz half sine wave. This 120 Hz signal is produced at diode connection 224 by combining the outputs of the bridge rectifier circuits 204 and 206 . Thus, the minimum Vchop PWM switching frequency is 10 times higher than 120 Hz, which is 1.2 kHz. It is beneficial for Vchop to have a PWM switching frequency that is at least 10 times the frequency of the combined hot inputs 202 a and 202 b in order to reduce visible flickering in the illumination of the one or more LEDs 228 . Similarly, the maximum Vchop PWM switching frequency is one-tenth the frequency of the signal produced by the SMPS power converter circuit 216 . For example, assuming a frequency of 120 kHz for the signal produced by the SMPS power converter circuit 216 , the maximum Vchop PWM frequency is 12 kHz. [0039] The combined output at diode connection 224 is fed into the SMPS power converter circuit 216 . The SMPS power converter circuit 216 performs a second PWM. For example, the SMPS power converter circuit 216 may perform PWM at a frequency of between 65 kHz and 120 kHz. This output of the SMPS power converter circuit 216 is used to drive current to the one or more LEDs 228 . [0040] The two pulse width modulated signals, Vchop and the output of the SMPS power converter circuit 216 , are input into AND gate 218 . The AND gate 218 combines the two signals as illustrated in FIG. 3 . The output of the AND gate 218 controls FET switch 220 . The FET switch 220 is connected to converter circuit 222 . The converter circuit 222 may be a step-down DC to DC converter that converts the combined output at diode connection 224 into a voltage configured to drive the LEDs 228 . In this example, converter circuit 222 is a buck-mode topology. Alternatively, the converter circuit 222 may be a flyback topology or other similar converter. [0041] While FIG. 2 depicts a particular configuration of blocks, it should be understood that the blocks may be configured differently or some blocks may be omitted without deviating from embodiments of the present invention. [0042] To further improve performance, the PWM switching frequency of Vchop can be dithered or varied. Dithering or varying the PWM switching frequency of Vchop improves power factor effects and total harmonic distortion effects by spreading the noise over a frequency range. For example, the PWM switching frequency of Vchop can be varied from 1 kHz to 3 kHz. In another example, the PWM switching frequency can be dithered to a range of frequencies, such as by switching among various PWM switching frequencies. The circuit may be configured to switch among the various PWM switching frequencies after a set number of periods. [0043] FIG. 3 depicts graphs showing exemplary outputs at the output of the SMPS power converter circuit 216 , at Vchop, and at the output of AND gate 218 . For example, the SMPS output is a signal with a frequency of 100 kHz, as illustrated in FIG. 3A , and Vchop is a signal with a PWM switching frequency of 2 kHz, as illustrated in FIG. 3B . [0044] For Vchop in FIG. 3B , the duty cycle is the percent of time that Vchop is ON as a fraction of the total period of the signal. In this example, the duration that Vchop is ON is the same as the duration for which Vchop is OFF. Thus, Vchop has a duty cycle of 50% and is said to be chopped at 50%. This case, where the duty cycle of Vchop is 50%, may exemplify the circumstance when only hot input 202 b is energized. When Vchop and the output of the SMPS power converter circuit 216 are combined at the output of the AND gate 218 , as illustrated in FIG. 3C , the result is a signal used for driving the one or more LEDs 228 with a medium intensity illumination. Similarly, a Vchop signal with a duty cycle of 25% would result in a signal that is ON for 25% of the signal period, and may exemplify the circumstance when only hot input 202 a is energized. [0045] FIG. 4 illustrates an exemplary circuit topology 400 for an LED driver circuit. One of ordinary skill in the art will readily appreciate that different values of components may be used, that some components can be removed, some components can be added, and that some components may be re-arranged while maintaining a functional driver circuit. [0046] Line 402 is a hot1 input, line 404 is a hot2 input, and line 406 is a neutral input. Components 408 and 410 are resistors. Components 412 and 414 are capacitors. Components 416 and 418 are rectifiers, which convert AC to DC. Components 420 and 422 are capacitors. Component 424 is a microchip, such as a PIC10F320. Components 426 , 428 , 432 are resistors. Component 430 is a capacitor. Components 434 and 436 are diodes. Components 438 , 440 , 442 , and 444 are resistors. Components 446 and 448 are diodes. Component 450 is a resistor. Components 452 and 454 are inductors. Components 456 and 458 are capacitors. Component 460 is diode. Components 462 , 464 , 466 , 468 , 470 , 472 , 474 , 476 , 478 , and 480 are resistors. Components 482 , 484 , 486 , and 488 are capacitors. Components 490 and 492 are diodes. Component 494 is a resistor. Components 496 and 498 are transistors. Component 500 is an LED driver chip that outputs a pulse width modulated signal. Component 502 is an inductor. Component 504 is a capacitor. Component 506 is a diode. Outputs 508 may be connected to one or more LEDs to power the LEDs in one of three states: low, medium, and high illumination. [0047] Although a feature may appear to be described in connection with a particular embodiment, one skilled in the art would recognize that various features of the described embodiments may be combined. Moreover, aspects described in connection with an embodiment may stand alone.

An LED bulb is described, comprising LEDs within a shell and a driver circuit to operate the LEDs at a plurality of brightness levels. The driver circuit comprises first and second inputs to receive AC, a neutral input, a converter circuit, first and second rectifier circuits, a detector circuit, and a processing circuit. The first rectifier circuit is connected to the first and neutral inputs and rectifies the AC received. The second rectifier circuit is connected to the second and neutral inputs and rectifies the AC received. The detector circuit is connected to the first and second rectifier circuits. The processing circuit has a first and a second processor input, and is connected to the detector circuit. The processing circuit produces a chop signal with a duty cycle based on whether the first or second input is hot. The converter circuit powers the LEDs based on the chop signal.

CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/666,292, filed on Jun. 29, 2012, the content of which is incorporated by reference herein in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to a door drive mechanism of a climate control system for a vehicle, and more particularly, relates to a door drive mechanism of the climate control system that actuates doors for heating, ventilating, and air conditioning applications using a gear mechanism. BACKGROUND OF THE INVENTION [0003] A motor vehicle typically includes a climate control system to maintain a temperature within a passenger compartment of the vehicle at a comfortable level by providing heating, cooling, and ventilation. Comfort can be maintained in the passenger compartment by an integrated system, referred to as a heating, ventilating, and air conditioning (HVAC) air-handling system. The HVAC air-handling system conditions air flowing therethrough and distributes the conditioned air throughout the passenger compartment. [0004] The design of an HVAC air-handling system can include features that control air flow volume, air temperature, and one or more air flow paths, for example. Performance of the HVAC air-handling system may be designed to comply with particular targets including temperature linearity, wherein linearity is a predictable rate of change in temperature. For all operating states, it can be desirable to manipulate hot air streams and cold air streams to produce the proper temperatures and a predictable rate of change in temperature. [0005] To comply with the desired linearity targets, HVAC air-handling systems can include features such as baffles, conduits, mixing plates, and/or climate control doors, or the like, to facilitate mixing of hot air streams with cold air streams. Undesirably, addition of these features and/or components can reduce airflow, degrade flow efficiency, increase noise, and increase the cost and weight of the system. Further issues can arise with a rate at which one or more ventilation conduits or climate control doors are opened and closed in the HVAC air-handling system. For example, mixing and delivery of air streams of various temperatures can be controlled by adjusting the rate at which a climate control door within a ventilation conduit is rotated throughout a range between a fully opened position and a fully closed position. [0006] An issue with HVAC air-handling systems is that certain designs do not have the ability to rotate a climate control door at a rate of speed (deg/s) that is less than a rate of speed (deg/s) of a drive gear mechanism that is rotating a gear set attached to the climate control door without increasing the total time of rotation beyond a desired target. One way to address this issue is by using a linear pitch gear set with a constant gear ratio that reduces the rate of door rotation relative to the rate of actuator or motor rotation. While this method is effective, it requires additional actuator rotation and additional rotation time. [0007] Another way to address this issue is by using a cam mechanism (kinematics) that involves a cam and pin interface that reduces the rate of door rotation relative to the rate of actuator or motor rotation. While this method is effective, it requires additional actuator rotation, additional rotation time, extra package space and, sometimes, extra components. Accordingly, improvements in ways to provide HVAC door rotation are desirable to optimize HVAC air-handing system operation. SUMMARY OF THE INVENTION [0008] Concordant and consistent with the present invention, an improved mechanism for a climate control system door drive mechanism for a vehicle that minimizes actuator rotation and rotation times to optimize air-handling system operation has surprisingly been discovered. [0009] According to the invention, a gear pair for a motor vehicle climate control system door drive mechanism includes a drive gear and a driven gear. The drive gear and the driven gear cooperate to form a gear pair, wherein the gear pair is constructed so that a gear ratio of the gear pair transitions from a linear gear ratio to a non-linear gear ratio. The non-linear gear ratio may be proportional to an exponential function. In one embodiment, the driven gear includes a first toothed portion having a substantially linear pitch radius and a second toothed portion having a pitch radius derived from an exponential function. [0010] In another embodiment, a door drive mechanism for a vehicle climate control system includes an actuator rotatably coupled to an actuator gear about an actuator axis of rotation. The actuator gear includes a toothed portion having a first plurality of teeth. A door gear includes a toothed portion having a second plurality of teeth intermeshed with the first plurality of teeth, the door gear rotatably connected to a vehicle climate control door about a door axis of rotation to drive the door upon rotation of the actuator. A first portion of the first plurality of teeth is arranged having a first constant pitch radius from the actuator axis of rotation and a second portion of the first plurality of teeth is arranged having a first variable pitch radius from the actuator axis of rotation. The variable pitch radius may be non-linear, and may further be derived from an exponential function. Additionally, the variable pitch may include a first portion having a substantially linear pitch and a second portion having a substantially non-linear pitch. [0011] The present invention therefore provides a climate control door drive mechanism that has the ability to slowly rotate climate control doors at a rate of speed necessary to meet design requirements while also providing the ability to still meet total rotation time requirements. As a result, a climate control door rotation speed may be linearly or non-linearly controlled when there is a need to meet temperature door linearity performance, and the climate control door rotation speed may also be increased to meet total temperature door rotation time performance. BRIEF DESCRIPTION OF THE DRAWINGS [0012] The above, as well as other advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, particularly when considered in the light of the drawings described herein. [0013] FIG. 1 is a perspective view of a prior art mechanism having a gear set with a constant linear pitch. [0014] FIG. 2 is a perspective view of a prior art cam mechanism. [0015] FIG. 3 is a perspective view of a non-linear, variable pitch gear set in a first door position according to an embodiment of the invention. [0016] FIG. 4 is a perspective view of the non-liner, variable pitch gear set of FIG. 3 in a second door position according to an embodiment of the invention. [0017] FIG. 5 is a graphical depiction of certain non-linear, variable pitch gear profiles according to an embodiment of the invention. DETAILED DESCRIPTION [0018] The following detailed description and appended drawings describe and illustrate various embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. [0019] A prior art mechanism 100 using a linear pitch gear set having a constant gear ratio is shown with reference to FIG. 1 . An actuator gear 112 includes an actuator gear hub 114 that is configured to receive an output shaft of an actuator mechanism (not shown). It is understood that the actuator mechanism may include a manually rotatable shaft, a motor, or other device having a rotational output. The actuator gear hub 114 is typically integrally attached to the actuator gear 112 so that a rotational force applied in the actuator gear hub 114 is translated directly to the actuator gear 112 . The actuator gear 112 includes a plurality of teeth 116 located on a predetermined portion of the circumference 118 . As shown in FIG. 1 , the actuator gear 112 has a fan shape that has an arcuate outer peripheral part 120 corresponding to a portion of the circumference 118 . A door gear 122 having a plurality of teeth 124 meshed with the plurality of teeth 116 of the actuator gear 112 is secured to a rotatable shaft 126 . The rotatable shaft 126 is attached to a gear door (not shown) that rotates integrally with the rotatable shaft 126 . The plurality of teeth 124 of the door gear 122 is included along an outer circumference 128 of the door gear 122 . Additionally, as shown in FIG. 1 , the outer circumference 128 of the door gear 122 may be less than 360 degrees. [0020] The actuator gear hub 114 defines an axis of rotation 130 about which the actuator gear 112 rotates. The outer circumference 118 of the actuator gear 112 is a fixed distance, or constant radius, R 1 from the axis of rotation 130 of the actuator gear 112 . The constant radius R 1 of the actuator gear 112 results in the actuator gear 112 having a fixed pitch radius from the axis of rotation 130 . [0021] Similarly, the rotatable shaft 126 of the door gear 122 defines an axis of rotation 132 about which the door gear 122 rotates. The outer circumference 128 of the door gear is a fixed distance, or constant radius, R 2 from the axis of rotation 132 of the door gear 122 . The constant radius R 2 of the door gear 122 results in the door gear 122 having a fixed pitch radius from the axis of rotation 132 . [0022] As a non-limiting example, in one configuration the door gear 122 may have a constant radius R 2 equal to about 60 mm, while the actuator gear 112 may have a constant radius R 1 equal to about 20 mm. When intermeshed as shown in FIG. 1 , the mechanism 100 develops a 3:1 gear ratio, meaning that for every 3 degrees of rotation of the actuator gear 112 , the door gear 122 rotates 1 degree. Due to the fixed pitch radii of both the actuator gear 112 and the door gear 122 , the rate of rotation by the door gear 122 is fixed in the 3:1 ratio. In this example, therefore, the actuator gear 112 must rotate 270 degrees to achieve a total rotation of 90 degrees by the door gear 122 (and by the gear door, not shown). The prior art design shown in FIG. 1 therefore provides for linear control of the gear door and the ability to rotate an air door at a rate of speed (deg/s) that is less than a rate of speed (deg/s) of an actuator, but only by adding considerable rotation distance and time to the mechanism 100 . [0023] Another known mechanism that provides the ability to rotate an air door at a rate of speed less than a rate of speed of a drive gear mechanism attached to a rotating gear door without increasing the total time of rotation beyond a desired target is shown in FIG. 2 . A cam drive mechanism 200 includes a cam 210 attached to a door lever 212 . The cam 210 includes an actuator hub 214 integrally formed thereon that is configured to receive an output shaft of an actuator mechanism (not shown). It is understood that the actuator mechanism may include a manually rotatable shaft, a motor, or other device having a rotational output. The actuator hub 214 is typically integrally attached to the cam 210 so that rotational force applied in the actuator hub 214 is translated directly to the cam 210 . The door lever 212 is attached to an air door (not shown) proximate a first end 216 , while a second end 218 of the door lever 212 is coupled to the cam 210 . A separate cam bracket 220 is used to mount the cam 210 to the actuator (not shown), and may further be useful to retain the cam 210 and the door lever 212 in proper alignment. As a non-limiting example, the cam 210 shown in FIG. 2 may be rotated by the actuator (not shown) through approximately 120 degrees of rotation, translating approximately 70 degrees of rotation to the air door (not shown) through the door lever 212 . The cam mechanism 200 therefore is able to provide effective temperature linearity control, but it may require additional actuator rotation and additional rotation time. The cam mechanism 200 also requires the extra cam bracket 220 , increasing the part count while adding weight, package volume, and cost. [0024] A door opening mechanism 300 is shown in FIGS. 3 and 4 that addresses the shortcomings of the prior art. In particular, FIG. 3 demonstrates the door opening mechanism 300 in a starting position, or a full hot door position, while FIG. 4 demonstrates the door opening mechanism 300 in an ending position, or a full cold door position. The door opening mechanism 300 includes an actuator gear 312 and a door gear 322 . The actuator gear 312 includes an actuator gear hub 314 that is configured to receive an output shaft of an actuator mechanism (not shown). It is understood that the actuator mechanism may include a manually rotatable shaft, a motor, or other device having a rotational output. The actuator gear hub 314 is typically integrally attached to the actuator gear 312 so that a rotational force applied in the actuator gear hub 314 is translated directly to the actuator gear 312 . The actuator gear 312 includes a plurality of teeth 316 located on a predetermined portion of the circumference 318 of the actuator gear 312 . As shown in FIG. 3 , the actuator gear 312 has a fan shape that has an arcuate outer peripheral part 320 corresponding to at least a portion of the circumference 318 . It is understood that the actuator gear 312 may have any desired shape that presents the arcuate outer peripheral part 320 . [0025] The door gear 322 includes a plurality of teeth 324 meshed with the plurality of teeth 316 of the actuator gear 312 and is secured to a rotatable shaft 326 . The rotatable shaft 326 is attached to a gear door (not shown) that rotates integrally with the rotatable shaft 326 . The plurality of teeth 324 of the door gear 322 is included along an outer circumference 328 of the door gear 322 . Additionally, as shown in FIGS. 3 and 4 , the door gear 322 has a fan shape that has an arcuate outer peripheral part 330 corresponding to at least a portion of the circumference 328 . The outer circumference 328 of the door gear 322 may be less than 360 degrees, and it is understood that the door gear 322 may have any desired shape that presents at least the arcuate outer peripheral part 330 that includes the plurality of teeth 324 intermeshed with the plurality of teeth 316 of the actuator gear 312 . [0026] The actuator gear 312 and the door gear 322 may be made from any suitable material, without limitation. Typically one gear material can be polyoxymethylene (POM) and the other gear material can be 40% mineral filled Nylon. However, it is understood that other materials and combinations of materials can be used. [0027] The actuator gear hub 314 defines an axis of rotation 332 about which the actuator gear 312 rotates. Similarly, the rotatable shaft 326 of the door gear 322 defines an axis of rotation 334 about which the door gear 322 rotates. Further, the axis of rotation 332 of the actuator gear 312 is separated from the axis of rotation 334 of the door gear 322 by a fixed center-to-center distance CD. It is understood that the actuator gear 312 and the door gear 322 are sized and shaped so that the actuator gear 312 rotates about the axis of rotation 314 and the door gear 322 rotates about the axis of rotation 334 while maintaining intermeshing of the plurality of teeth 316 of the actuator gear 312 with the plurality of teeth 324 of the door gear 322 , and while maintaining the fixed center-to-center distance CD. [0028] The exemplary door opening mechanism 300 of FIGS. 3 and 4 may be distinguished from the prior art, however, by an ability to provide a non-linear predefined variable gear pitch in at least a portion of the gear pair travel. As non-limiting examples, the door opening mechanism 300 may provide a transition from a linear to a non-linear gear pitch near the start of gear travel. The door opening mechanism may also be configured to provide a transition from a non-linear gear pitch to a linear gear pitch near the start of gear travel. Also, the door opening mechanism may be configured to provide both transitions from linear to non-linear gear pitch and from non-linear to linear gear pitch at any point of the gear travel. [0029] A variable gear pitch is provided in the door opening mechanism 300 by providing a predefined variable gear pitch for both the actuator gear 312 and the door gear 322 . With reference to the actuator gear 312 , the arcuate outer peripheral part 320 includes a first actuator gear arcuate portion 340 and a second actuator gear arcuate portion 342 . In FIGS. 3 and 4 , the first actuator gear arcuate portion 340 includes that portion of the arcuate outer peripheral part 320 closest to the axis of rotation 332 of the actuator gear hub 314 having a constant pitch radius R ac , while the second actuator gear arcuate portion 342 includes that portion of the arcuate outer peripheral part 320 farthest away from the axis of rotation 332 of the actuator gear hub 314 having a variable pitch radius R av . It is understood, however, that other configurations of the arcuate outer peripheral part 320 may be used, as desirable. With reference to the door gear 322 , the arcuate outer peripheral part 330 includes a first door gear arcuate portion 350 and a second door gear arcuate portion 352 . In FIGS. 3 and 4 , the first door gear arcuate portion 350 of the door gear 322 includes that portion of the arcuate outer peripheral part 330 farthest away from the axis of rotation 334 of the door gear 322 having a constant pitch radius R dc , while the second door gear arcuate portion 352 of the door gear 322 includes that portion of the arcuate outer peripheral part 330 closest to the axis of rotation 334 of the door gear 322 having a variable pitch radius R dv . It is understood, however, that other configurations of the arcuate outer peripheral part 330 may designed, as desirable [0030] FIG. 3 shows the door opening mechanism in a starting position corresponding to a full hot mixing position of the gear door. The first actuator gear arcuate portion 340 of the actuator gear 312 having constant pitch radius R ac corresponds to approximately the first 30 degrees of rotation by the actuator gear 312 in the clockwise direction. The first door gear arcuate portion 350 of the door gear 322 having a constant pitch radius R dc corresponds to approximately the first 10 degrees of rotation by the door gear 322 in the counter-clockwise direction. It is understood that other degrees of rotation can be used as desired. As the actuator gear 312 rotates through the first actuator gear arcuate portion 340 that also corresponds to the first door gear arcuate portion 350 , the door gear 322 , fixed to the air door (not shown), rotates at a constant speed of 1 degree for every 3 degrees of rotation by the actuator gear 312 , corresponding to a 1:3 gear ratio. [0031] The second actuator gear arcuate portion 342 of the actuator gear 312 having variable pitch radius R av corresponds to approximately the next 130 degrees of rotation by the actuator gear 312 in the clockwise direction as shown in FIG. 3 . The second door gear arcuate portion 352 of the door gear 322 having a variable pitch radius R dv corresponds to approximately the next 80 degrees of rotation by the door gear 322 in the counter-clockwise direction. It is understood that other degrees of rotation can be used as desired. Thus, for the next 130 degrees of actuator gear rotation, the pitch between the two gears changes until the door rotates an additional 80° of rotation. In the embodiment shown in FIGS. 3 and 4 , the variable pitch radius R av of the actuator gear 312 and the variable pitch radius R dv of the door gear 322 change exponentially to achieve the example door gear movement. [0032] Using the non-linear, variable pitch gear pair, for example, a user can operate a temperature control knob for an HVAC air-handling system that is coupled to the actuator gear. A rotation of the knob throughout a portion of a temperature range may provide a corresponding movement of the door gear, while rotation of the knob throughout another portion of the temperature range may provide an increase or decrease in the corresponding movement of the door gear. [0033] The door opening mechanism 300 may include corresponding non-linear, variable pitch actuator gears 312 and door gears 322 (gear pairs) having a multitude of variable profiles. For example, Table 1 shows two exemplary gear profiles. According to Example 1, a first arcuate portion of the gear pair may include a constant 2(actuator):1(door) linear profile gear ratio in the direction rotating from full hot to full cold, a second arcuate portion of the gear pair may include a non-linear profile until the gear pitch reaches a 1.5:1 gear ratio, after which a third arcuate portion of the gear pair maintains the 1.5:1 linear profile gear ratio. The total amount of Example 1 temperature actuator rotation is approximately 155 degrees, while the total amount of door rotation is approximately 90 degrees. [0034] According to the Example 2 of Table 1, a gear pair may be designed having a first arcuate portion with a constant 3(actuator):1(door) linear profile gear ratio in the direction rotating from full hot to full cold, and a second arcuate portion having a non-linear variable pitch gear profile until the end, at which the gear profile may specify, for example a 0.8:1 gear ratio. The total amount of the variant of Example 2 temperature actuator rotation is approximately 160 degrees. The total amount of door rotation is approximately 94 degrees. [0000] TABLE 1 Pitch Definition Example Start (FH) Middle End (FC) reason 1 constant: 2:1 variable constant: 1.5:1 Packaging and improve- ment of temp. linearity while maintaining the rotation time require- ment. 2 constant: 3:1 variable variable: 0.8:1 Improvement of temp. linearity while maintain- ing the rotation time requirement. [0035] Several reference non-linear profiles for exemplary gear pairs are also shown graphically in FIG. 5 . In particular, FIG. 5 shows a slope of the gear profile as the pitch radius changes from start to finish over 130° of rotation. The function that defines the slope in this case is an exponential function, but it is understood that any applicable function may be utilized to establish appropriate gear pair profiles. The curve 360 closest to the origin (X,Y of 0,0) in FIG. 5 shows a first minor exemplary profile. The second closest curve 362 to the origin shows a base exemplary profile. The third closest curve 364 to the origin shows an exemplary actuator pitch profile. The fourth closest curve 366 to the origin shows an exemplary major profile. The curve 368 furthest from the origin shows a reference circle. [0036] According to one embodiment, the gear pitch radius curves in FIG. 5 may be derived using exponential functions. For example, the actuator gear variable pitch radius R av and rotation angle Θ may have the form of Equation 1: [0000] R av =Ae kθ   Equation 1 [0000] where R av is the pitch radius of the actuator gear, θ is the angle of actuator rotation and A and k are chosen constants. Similarly, for a given center-to-center distance CD, a corresponding door gear variable pitch radius Rdv may have the form of Equation 2: [0000] R dv =CD−R av   Equation 2 [0000] where R dv is the pitch radius of the door gear. Equation 3 may then be used to determine a door gear rotation angle Ø, where: [0000] Ø=1 /k*In [( CD−Ae kΘ )/ A]   Equation 3 [0037] In Equations 1-3, CD, k, A and Θ are inputs and R av , R dv and Ø are outputs. [0038] According to the invention, the non-linear, variable pitch gear pair design can be used with climate control door drives in a motor vehicle air-handling system. Using this non-linear gear technology, it is possible to reduce the rate of speed of the climate control door rotation relative to the rate of speed of the actuator output shaft rotation in those locations where the climate control door is sensitive to temperature control curve linearity. Then, at other climate control door locations, where the climate control door position is less sensitive to temperature linearity, the rate of the climate control door rotational speed relative to that of the actuator output shaft speed can be increased to a speed that reduces a time necessary to completely rotate the door. Furthermore, by reducing the rate of speed of the door rotation at the sensitive end of rotation, it is possible to reduce the need for ventilation conduits or shades. The reduction in shade use can thereby increase the amount of cross section for airflow. Therefore, improved temperature linearity can be achieved with an increased cross section in airflow without increasing the time needed to rotate the door from one end of rotation to the other. [0039] While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes may be made without departing from the scope of the disclosure, which is further described in the following appended claims.

A gear pair for a motor vehicle climate control system door drive mechanism includes a drive gear and a driven gear. The drive gear and the driven gear cooperate to form a gear pair, wherein the gear pair is constructed so that a gear ratio of the gear pair transitions from a linear gear ratio to a non-linear gear ratio. The non-linear gear ratio may be proportional to an exponential function. The gear pair is applied to linearly control a climate control door rotation speed when there is a need to meet temperature door linearity performance, and is applied to increase the climate control door rotation speed to meet total temperature door rotation time performance.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a process for the preparation of oleum having a concentration of 10 to 45% by weight of SO 3 and sulphuric acid having a concentration of 94 to 100% by weight by joint combustion of sulphur with atmospheric oxygen and if appropriate SO 2 -containing and (NO) x -containing gases from the thermal cleavage of sulphuric acid, conversion of the SO 2 -containing gases to SO 3 -containing gases in the presence of vanadium catalysts and absorption of the SO 3 -containing gases to produce oleum and/or sulphuric acid. 2. Brief Description of the Prior Art The literature discloses differing processes for the preparation of oleum and sulphuric acid. In the thermal processes (sulphur combustion using atmospheric oxygen, metal sulphide roasting, sulphuric acid cleavage, sulphate processes), in addition to sulphur-dioxide-containing gases, there are also formed nitrogen oxides, (NO) x , which are produced directly from nitrogen and oxygen above 1 000° C. Additional (NO) x is introduced by the starting products themselves. Under the combustion conditions, (NO) x is without exception NO. The (NO) x is absorbed, as are also the sulphur-trioxide-containing gases which are formed from the SO 2 -containing gases in the presence of the vanadium catalyst, so that the sulphuric acid formed or the oleum is contaminated with absorbed (NO) x in the form of nitrosylsulphuric acid. It is assumed that (NO) x is converted to nitrosylsulphuric acid in the following manner: NO+SO 3 →NO 2 +SO 2   Equation 1 NO+NO 2 +H 2 SO 4 →NOHSO 4 +H 2 O  Equation 2 Nitrosylsulphuric acid, which is analytically detectable by hydrolysis with water to give HNO 2 , is a powerful corrosive agent for steel and chrome-nickel stainless steels and leads to considerable surface erosion on apparatuses and piping. To reduce the nitrosylsulphuric acid content, therefore, according to a known proposal, 40% strength dihydrazine sulphate solution is introduced. DE-A-4 002 465 describes a process by means of which up to 95% by weight of the total nitrogen oxides can be removed. DE-A-4 002 465 relates to a process for the continuous preparation of oleum at a concentration of 10 to 45% by weight SO 3 and/or H 2 SO 4 by combustion of sulphur with atmospheric oxygen by the principle of superstoichiometric and substoichiometric combustion, cooling the resultant sulphur-dioxide-containing gases to 390° C. to 480° C., catalytic conversion of these gases to sulphur-trioxide-containing gases in the presence of a vanadium-containing catalyst using the principle of single or double contact catalysis, absorption of the sulphur-trioxide-containing gases after cooling, if appropriate removal of liquids from the gases after absorption and energy production, the combustion of sulphur with atmospheric oxygen being carried out with the addition of dry SO 2 -containing gases which contain up to 5 000 ppm of (NO) x , preferably less than 2 000 ppm of (NO) x , calculated as NO. The SO 2 -containing dry gases, which can contain up to 5 000 ppm of (NO) x , calculated as NO, used are cleavage gases from the thermal cleavage of waste sulphuric acids, with these cleavage gases being able to contain 5 to 10% by volume of O 2 , 5 to 8% by volume of SO 2 , <200 ppm of CO, <1 000 ppm of (NO) x , <50 ppm of hydrocarbon compounds and 82 to 90% by volume of H 2 O, N 2 and CO 2 . Using these processes, the dry SO 2 -containing gases can be introduced directly into the combustion chamber in which sulphur is burnt with oxygen, or can be introduced into the combustion chamber after mixing with combustion air. It is important that the SO 2 -containing gases (nitrous SO 2 -containing gases) are burnt jointly with sulphur. In a temperature variant, sulphur is burnt at temperatures between 500° C. and 1 000° C. (measured at the outlet of the combustion chamber upstream of gas cooling), chiefly between 700° C. and 950° C. The known process has the disadvantage that a breakdown of up to 95% by weight of (NO) x occurs. However, the residual amounts of (NO) x , as may be seen from the examples, lead to concentrations of >25 mg of NO/m 3 (S.T.P.). In practice this means that in the preparation of oleum of high concentrations of 30 to 45% by weight, as is required for the preparation of pure sulphur trioxide and oleum 65%, virtually all of the (NO) x was absorbed in the form of nitrosylsulphuric acid and led to a high accumulation in the oleum cycles of the oleum distillation. Not until the concentration is below 27% free SO 3 does the degree of absorption of (NO) x decrease noticeably. It is an object of the present invention, therefore, in the existing process, to decrease the (NO) x content considerably below 95% to contents of <5 mg of NO/m 3 (S.T.P.). Surprisingly, this object is achieved by the inventive process. The advantages of the inventive process are the reduction of the nitrosylsulphuric acid content, the reduction of the maintenance costs which are caused by corrosion, and the complete avoidance of the use of dihydrazine sulphate solution within the meaning of the objective according to section 37 of the German Dangerous Substance Act of replacing carcinogenic working materials. SUMMARY OF THE INVENTION The invention therefore relates to an improved process for the continuous preparation of oleum of a concentration of 10 to 45% by weight of SO 3 and/or sulphuric acid of a concentration of 94 to 100% by weight of H 2 SO 4 by combusting sulphur with atmospheric oxygen according to the principle of superstoichiometric combustion, cooling the resultant sulphur-dioxide-containing gases to 350° C. to 500° C., catalytically converting the cooled gases to give sulphur-trioxide-containing gases in the presence of a vanadium-containing catalyst using single or double contact catalysis, absorbing the sulphur-trioxide-containing gases after cooling, optionally removing liquids from the gases after absorption and energy recovery, the improvement comprising injecting liquid sulphur into the hot combustion gas stream perpendicular to the main direction of flow in the form of a fan using one or more bimodal fan-type nozzles. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 a shows a possible arrangement of fan-type nozzles (Nozzles in step A to B) in two combustion levels of an upright boiler 1 . FIG. 1 b shows section A-B of the fan type nozzles. FIG. 2 shows graphically a selection of operating sequences of a fan-type nozzle to be implemented. FIG. 2 a shows operation with two constant operating states during an atomization period. FIG. 2 b shows a possible operating state in which an injection period is composed only of a pause and 2-component injection. FIG. 2 c shows a sequence consisting only of 2-component injection. FIG. 3 shows qualitative throughput diagrams of two fan-type nozzles of differing size and output. FIG. 4 shows a process diagram of embodiment of the inventive process, without the inventive process being restricted thereto. FIG. 5 shows a nozzle arrangement in according to the present invention. DETAILED DESCRIPTION OF THE INVENTION In the achievement of the inventive object, the sulphur is burnt in a special combustion chamber suitable for the combustion of liquid sulphur having a cooled oven wall. The combustion chamber is cooled via a steam boiler, typically via an externally mounted boiler wall, which consists of individual tubes welded together. The sulphur is introduced in a single-stage and/or multistage manner via a plurality of special nozzles which are installed peripherally in the combustion space and have an atomization aid. Typically, the combustion gas stream enters the combustion space without swirl or with low swirl and flows through this combustion space in the form of back-flow-free and low-turbulence plug flow into the combustion space. The combustion gas of atmospheric oxygen usually contains dry SO 2 -/(NO) x -containing gases from the thermal cleavage of sulphuric acid, which can contain up to 5 000 ppm of (NO) x , calculated as NO. Preferably, the SO 2 -containing gases used are dry cleavage gases from the thermal cleavage of waste sulphuric acids. These cleavage gases preferably contain 4 to 10% by volume of O 2 , 2 to 9% by volume of SO 2 , <200 ppm of CO, <2 000 ppm of (NO) x , <50 ppm of hydrocarbon compounds and 82 to 90% by volume of N 2 and CO 2 . In a further variant of the process, the SO 2 -containing dry gases which can contain up to 5 000 ppm of (NO) x used are combustion gases from the combustion of sulphur-containing materials. Preferably, the ratio of the amount of SO 2 from the gases added from the thermal cleavage to the amount of SO 2 from the combustion of sulphur is between 1:5 and 3:1. To carry out the process in accordance with the invention, the dry SO 2 -containing gases can be introduced directly into the combustion chamber in which the combustion of the liquid sulphur with oxygen is carried out, or they can be introduced into the combustion chamber after mixture with the combustion air. It is important that the SO 2 -containing gases which can contain up to 5 000 ppm of (NO) x (nitrous SO 2 -containing gases) are burnt together with the sulphur. The NO content at the inlet of the combustion chamber can therefore be between 0 and 5 000 ppm. The combustion gas is preheated using heat of reaction from the catalyst system and customarily enters the combustion space at a temperature of 250 to 350° C. The sulphur can be burnt in the inventive process in a manner known per se in a single stage or in a plurality of stages, preferably in 2 stages. By means of the special injection technique, in combination with the cooled combustion space and a two-stage arrangement, the flame temperature is kept in a range from 500° C. to 700° C., depending on the combustion output. The (NO) x present in the combustion air is chemically decomposed and the formation of new “thermal” (NO) x is prevented. By means of a heat exchange surface design known to those skilled in the art in the evaporator and integrated superheater, it is ensured that the gas outlet temperature at the top of the apparatus can be adjusted between 350 and 500° C. In the novel process, the liquid sulphur is injected in the shape of a fan into the combustion gas stream using special two-component nozzles. Preferably, here, the fan-type nozzles are pulse-operated at a frequency of 5 s −1 to 70 s −1 . Pulsed operation of the fan-type nozzles is carried out in an alternating cycle between dilution of liquid sulphur and impinging with dry air compressed to 2 to 10 bar and heated to 120° C. to 150° C., nitrogen or a corresponding combustion gas mixture. This pulse operation is usually termed “bimodal operating mode”. As a result of this pulse operation, the injection constantly alternates between pressure injection and two-component injection. The fan-type nozzles are arranged in the form of a ring in the combustion chamber in groups each of 3 to 8, preferably 4. Between the combustion stages the SO 2 -containing gases are cooled in each case via evaporator surfaces. After each combustion stage, the gas is preferably cooled to 400 to 600° C. SO 2 - and air-containing gas mixture enters from the bottom of, and into a vertically arranged combustion chamber. The wall of the combustion chamber consists of the tube wall of a natural circulation evaporator or forced circulation evaporator. The evaporation takes place in principle superstoichiometrically, that is to say with sufficient air excess, in a single to multistage manner, preferably single or two-stage manner. The air excess is preferably a molar ratio of O 2 :SO 2 of 1.1 to 0.9. In accordance with the objective of not forming nitrogen oxides in the combustion and reducing nitrogen oxides present in the combustion air, the bimodally atomizing fan-type nozzles are adapted. The following facts are taken into account for optimal atomization: thermal (NO) x formation depends on the temperature peaks present in the flame, their temperature and exposure time, the reduction of existing and formed (NO) x depends on the surface area of the reducing sulphur and its uniform area distribution over the combustion chamber cross section. For injecting the sulphur the following applies: to distribute the sulphur as far as possible over the entire cross section in such a manner that the local release of heat per unit area and combustion air pass through is of equal size, to achieve the lowest possible combustion temperature, as far as possible to prevent turbulent mixture. This is achieved if the sulphur is atomized perpendicularly to the flow of low-turbulence influent combustion air of the same velocity (plug flow) via a plurality of fan-type nozzles distributed peripherally on the circumference of the combustion chamber. In instances where the total amount of the sulphur to be injected is split and introduced successively with intermediate heat removal, it is possible, at low combustion temperatures, to increase the SO 2 -content independently of the combustion temperature. The invention is further described with reference to the figures but without limitation thereto. FIG. 1 shows a possible arrangement of fan-type nozzles in two combustion levels of an upright boiler 1 . Sulphur 4 is injected using atomizing gas 5 into the (NO) x -containing combustion air 2 flowing in plug flow into the boiler 1 via a plurality of nozzles 3 having a fan-type injection pattern in the combustion level I. The section A-B shows the arrangement of nozzles at the circumference of the boiler in level I. After the combustion of the sulphur, heat is removed from the flowing gas by means of a first heat exchanger 6 . Further downstream the remaining sulphur is injected into the combustion level II using hybrid nozzles 8 which can differ from the hybrid nozzles 3 of the combustion level I in number, output, spray angle and atomizing fineness. The subsequent heat exchanger typically represents the apparatuses required for steam generation and combustion air preheating. The SO 2 -containing and denox-treated process gas 9 passes to the double-contact catalyst. In accordance with the invention where the combustion temperature is to be the same or substantially the same at each point of the flame carpet, the heat release and thus the sulphur concentration per unit area must be identical or substantially identical. Accordingly, in the vicinity of the combustion chamber inner wall, because of the area which increases with the square of the radius, a different amount of sulphur is introduced in a uniformly distributed manner to that in the centre of the flame carpet. If the entire combustion chamber cross section is considered to be composed of an inner circle having diameter d and the annulus between the inner circle and inner combustion chamber wall having diameters D and d, and if it is further assumed that d is half of D, only one quarter of the sulphur passes into the inner surface enclosed by d, as opposed to three-quarters of the sulphur into the annulus. FIG. 2 shows graphically a selection of operating sequences of a fan-type nozzle to be implemented. FIG. 2 a shows operation with two constant operating states during an atomization period. The liquid is injected during a period between the pauses in which only atomizing gas leaves the hybrid nozzle. In this operating point, the ratio of mass flow rates of atomizing gas and liquid κ has the value infinity (κ=∞). After the end of the pause, the 2-component injection starts firstly with a large amount of atomizing gas and very little liquid. With advancing time the liquid proportion increases and the proportion of atomizing gas becomes less up to κ=0, the point at which the fan-type nozzle operates as a pure pressure nozzle and this state is maintained for a short time. Thereafter the 2-component injection begins again, characterized by a variable mass flow ratio κ. At κ=∞, the operating state “pause” is achieved; this completes an injection period. As a result of the changing operating states, injection with a very large droplet size spectrum, up to 1:1 000, takes place. The finest droplets are produced at the start and at the end of the 2-component injection, and the largest during the pressure nozzle period. During the two phases of the 2-component injection, the size of the mean droplet diameter d50 changes constantly with the change in κ. The greatest throw distance is achieved with large droplets by pressure nozzle operation. The number of droplets generated and thus the proportion of droplets penetrating into the cross-flow gas can be influenced by varying pressure and pulse frequency. FIG. 2 b shows a possible operating state in which an injection period is composed only of a pause and 2-component injection. As a result not only the mean droplet size d50 but also the maximum droplet diameter decrease. The injection becomes finer and the throw distance decreases. FIG. 2 c shows a sequence consisting only of 2-component injection. During one period, neither the operating state achieves a pause nor does pressure injection take place. FIG. 3 shows qualitative throughput diagrams of two fan-type nozzles of differing size and output. Using the mass flow rate of the liquid as a parameter, for both nozzles the volumetric flow rate of the atomizing gas is plotted against the pressure drop Δp of the fan-type nozzle. The two arrows pointing steeply downward give the direction of the increasing mass flow rate of the liquid. At a constant pressure drop, the increasing liquid mass flow rate m, the mean droplet diameter d50 increases; the mass flow rate ratio κ behaves in the opposite manner, it decreases. Another factor influencing spray fineness is the spray angle φ. Since measurements of the droplet size for fan-type nozzles as a function of the spray angle φ are only known to date patchily, the effect of spray angle φ in fan-type nozzles whose gap width changes with the spray angle can only be estimated assuming that the relationship known from the pressure nozzle atomization in the case of nozzles having circular nozzle outlet such as d50˜d bore hole and d50˜1/Δp 0.33 also applies to the fan-type nozzle. Based on a mean spray angle of φ=90°, a change in the mean droplet diameter of up to 1% per 1° spray angle deviation from a mean spray angle φ=90 would be expected. The effect of the mass flow rate ratio κ on the atomization fineness in 2-component injection can be described to a first approximation with the e function d50˜1/e κ . Since the fan-type nozzle is usually operated in the range 0.05≦κ0.25, small changes of κ lead to relatively large changes of the mean droplet diameter d50. The atomization fineness is affected, as mentioned previously, by the gap width of the outlet slot which in the present embodiment is rectangular in silhouette. Higher throughputs require larger nozzles and thus also larger outlet slots with correspondingly wider gap. Since, as already mentioned, the gap width substantially influences the atomization fineness, d50 increases with κ=const. with the use of larger nozzles. In the practice of the invention, interventions for adjusting injection fineness, droplet size spectrum and throw distance, the change in atomization fineness during operation by varying the pressure drop Δp at the nozzle, and, with the use of a plurality of lances distributed around the circumference, the possibility of changing nozzle during operation, the fan-type nozzle injection meets the requirements for (NO) x -free sulphur combustion and additional denox treatment of the nitrogen oxides present in the combustion air better than the known prior art. FIG. 4 shows an illustrative embodiment of the inventive process, without the inventive process being restricted thereto: 1 Air dryer 2 Gas dryer 3 Fan 4 Heat exchanger 5 Sulphur burner/steam boiler 6 Heat exchanger 7 Primary contact catalyst 8 Heat exchanger 9 Heat exchanger 10 Oleum absorber 1 11 Oleum absorber 2 12 Intermediate absorber 13 Filter 14 Secondary contact catalyst 15 Heat exchanger 16 Final absorber 17 Filter 18 Air 19 Sulphur 20 SO 2 -/(NO) x -containing gas from thermal cleavage of sulphuric acid or other sources 21 Oleum 22 Sulphuric acid 23 Stack off-gas The inventive process is to be described in more detail below with reference to the following examples, without a restriction to be understood herein. EXAMPLES Example 1 In an industrial plant for producing oleum of concentration 15 to 38% by weight of free SO 3 and sulphuric acid of concentration 96.5 to 99.5% by weight H 2 SO 4 , based on the combustion of liquid sulphur employing superstoichiometric sulphur combustion, and the 3+2 double contact catalyst process, 38 000 m 3 (S.T.P.) of air are dried in a gas dryer at 65° C. In a combustion chamber, liquid sulphur is burnt via 4 two-component nozzles which are installed in the combustion space symmetrically together with an ignition nozzle, injected with the dried air and burnt to form SO 2 -containing gas of a temperature of 651° C. The gas is fed to a 3-tray primary contact catalyst. The NO content in the comparative experiment without additional metering is below the limit of detection of the online measuring instrument of <2 mg of NO/m 3 (S.T.P.). The gas is processed in a known manner, as shown in FIG. 1 , to give sulphuric acid 98.5% and oleum 35%. The nozzles are arranged as shown in FIG. 1 in section A-B. The nozzles had an output, based on water, of 500 l/h (cross section DN 50 ). The outer protective air which does not participate in the injection was 30 m 3 /h per nozzle. In 4 nozzles, 3 450 kg of sulphur/h were injected at a pressure of 4.9 bar and 130° C. together with a total of 1 000 m 3 /h atomizing air at 130 degrees. The flame length extends to the opposite side, so that the total area of the combustion space is covered. The flame pattern of the bright white flame is uniform. As a result of introducing the air by means of radially arranged air boxes, the flame rolls, which causes a certain gas slip. Upstream of the fan, varying amounts of NO gas are introduced into the dried air from a gas cylinder. The resultant measured values at the steam boiler outlet are shown in the following Table 1: mg of NO/m 3 Continuous feed of (S.T.P.) at the oven Degradation rate in % NO gas in [l/h] outlet based on the amount used   0  1 not applicable 1 000 10 72 2 000 20 71 2 500 26 71 In the 2 nd combustion level, similarly to the above-mentioned, at an original concentration of 100 mg of NO/m 3 (S.T.P.), 9 mg can reliably be achieved, equivalent to a degradation rate of 91%. Example 2 In an experiment as above, plug flow was produced, however, by introducing air perpendicularly to the lame plane. The sulphur nozzles were arranged as shown in FIG. 5 . Nozzle 5 in FIG. 5 is an ignition nozzle (self-ignition of sulphur by means of hot air approximately 500° C.). a) Combustion with 2 Nozzles and Ignition Nozzle No. 5. Using sulphur nozzles No. 1 (580 kg/h), No. 2 (830 kg/h) and No. 5 (590 kg/h), in total 2 000 kg of sulphur/h were burnt. The total air rate of approximately 25 550 m 3 (S.T.P.)/h were preheated to 270° C. After the combustion, an SO 2 -containing gas resulted at 440° C. having an SO 2 content of 5.48% by volume of SO 2 . The sulphur pressure at the nozzles was 5.6 bar. The compressed air rate was in total 430 m 3 /h. Continuous mg of NO/m 3 feed (S.T.P.) mg of NO/m 3 Degradation rate of NO gas in in the combustion air (S.T.P.) in % based on the [l/h] (calculated) at oven outlet amount used   0  0  0 Not applicable 2 500 131  68 48 3 500 183 116 37 4 500 236 147 38 b) Combustion with 3 Nozzles and Ignition Nozzle No. 5. Using the sulphur nozzles No. 1 (660 kg of S/h), No. 2 (610 kg of S/h), No. 3 (900 kg of S/h) and No. 5 (410 kg of S/h), in total 2 580 kg of sulphur/h were burnt. The total air rate of approximately 36 330 m 3 (S.T.P.)/h was preheated to 160° C. After the combustion, an SO 2 -containing gas resulted at 913° C. having an SO 2 content of 5.01% by volume of SO 2 . The sulphur pressure at the nozzles was 5.6 bar. The compressed air rate was in total 430 m 3 /h. Continuous mg of NO/m 3 feed (S.T.P.) mg of NO/m 3 Degradation rate of NO gas in in the combustion air (S.T.P.) in % based on the [l/h] (calculated) at oven outlet amount used   0  0  0 Not applicable 2 500  92  0 100  3 500 129 36 72 4 500 165 68 59 c) Combustion with 4 Nozzles and Ignition Nozzle No. 5. Using the sulphur nozzles No. 1 (810 kg of S/h), No. 2 (780 kg of S/h), No. 3 (490 kg of S/h), No. 4, (830 kg of S/h), No. 5 (690 kg of S/h), in total 3 600 kg of sulphur/h were burnt. The total air rate of approximately 44 800 m 3 (S.T.P.)/h was preheated to 70° C. After the combustion, an SO 2 -containing gas resulted at 835° C. having an SO 2 content of 5.48% by volume of SO 2 . The sulphur pressure at the nozzles was 5.6 bar. The compressed air rate was in total 460 m 3 /h at a pressure of 5.5 bar. Continuous mg of NO/m 3 feed (S.T.P.) mg of NO/m 3 Degradation rate of NO gas in in the combustion air (S.T.P.) in % based on the [l/h] (calculated) at oven outlet amount used   0  0 0 not applicable 4 000 120 0 100

The invention relates to a process for the continuous preparation of oleum of a concentration of 10 to 45% by weight of SO 3 and/or sulphuric acid of a concentration of 94 to 100% by weight of H 2 SO 4 by combustion of sulphur with atmospheric oxygen according to the principle of superstoichiometric combustion, cooling the resultant sulphur-dioxide-containing gases to 350° C. to 500° C., catalytic conversion of these cooled gases to give sulphur-trioxide-containing gases in the presence of a vanadium-containing catalyst using single or double contact catalysis, absorption of the sulphur-trioxide-containing gases after cooling, if appropriate removal of liquids from the gases after absorption and energy recovery, with liquid sulphur being injected into the hot combustion gas stream perpendicular to the main direction of flow in the form of a fan using one or more bimodal fan-type nozzles.

BACKGROUND OF THE INVENTION The present invention relates to skylights, and more particularly to tubular skylights, which include a reflective tube extending downwardly from the dome. Tubular skylights have acquired increasing popularity as a means of introducing natural light into a building interior. These skylights include a dome mounted on the building roof, a light diffuser mounted in the building ceiling, and a reflective tube interconnecting the dome and the diffuser. Natural light entering the skylight through the dome reflects downwardly through the tube to the diffuser. The tube in a sense acts as a gigantic optical fiber. Typically, the domes are fabricated of acrylic; and the tube is fabricated of reflective aluminum. A tubular skylight of this type is sold by ODL, Incorporated, the assignee of the present invention, under the trademark EZ LIGHT. The efficiency of such skylights (i.e. the amount of natural light reaching the building interior) is primarily a function of the amount of light passing through the dome into the tube and of the reflective efficiency of the tube. It is desirable to channel or steer as much light as possible downwardly through the tube to illuminate the building interior. One such approach includes positioning a reflector inside the dome above the roof to reflect light downwardly into the tube. A tubular skylight of this type is illustrated in U.S. Pat. No. 5,099,622, issued Mar. 31, 1992, to Sutton, and entitled "Skylight." However, this approach is relatively complex structurally, relatively expensive, and aesthetically deficient. Further, the reflector may actually decrease the performance of the skylight when no direct sunlight is present, because the reflector blocks a portion of the ambient light. SUMMARY OF THE INVENTION The aforementioned problems are overcome in the present invention wherein the dome of a tubular skylight includes an exterior surface having a prismatic portion to reflect light downwardly into the tube. Preferably, the prismatic portion is located on the northern portion of the dome. Consequently, sunlight entering the southern portion, and to a lesser extent the eastern and western portions, of the dome at relatively low angles is reflected by the prismatic surface downwardly into the tube. In the disclosed embodiment, the dome is hemispherical including a base and an apex. The prismatic surface includes a plurality of vertical grooves each extending between the base and the apex along great circles passing through the apex. The grooves begin at the base and terminate short of the apex. Further preferably, the grooves are located in an angular segment of the hemispherical dome. The prismatic surface increases the amount of light directed or steered downwardly through the tube. The enhancement is most notable when the sun is relatively low in the sky as in the morning, the late afternoon and evening, and during the winter months. The dome also increases both the portion of the day and the number of seasons during which the skylight provides effective interior lighting. These and other objects, advantages, and features of the invention will be more fully understood and appreciated by reference to the detailed description of the preferred embodiment and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a tubular skylight having the dome of the present invention mounted within a building; FIG. 2 is a perspective exploded view of the tubular skylight; FIG. 3 is a top plan view of the dome; FIG. 4 is a sectional view of the dome taken along line IV--IV in FIG. 3; FIG. 5 is a fragmentary sectional view of the prismatic portion of the dome showing the grooves in the exterior surface; FIG. 6 is a schematic illustration of noon-day sun rays at the vernal and autumnal equinoxes; and FIG. 7 is a schematic illustration of morning sun rays at the vernal and autumnal equinoxes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A tubular skylight constructed in accordance with a preferred embodiment of the invention is illustrated in FIGS. 1 and 2 and generally designated 10. As perhaps most clearly illustrated in FIG. 2, the skylight includes a dome assembly 12, a diffuser assembly 14, and a tube assembly 16 interconnecting the dome and diffuser assemblies. The skylight 10 is installed in a building B having roof R and ceiling C. More particularly, the dome assembly 12 is mounted within the roof R; and the diffuser assembly 14 is mounted within the ceiling C. The tubular assembly 16 extends between the dome assembly 12 and the diffuser assembly 14 to channel light from the dome to the diffuser. With the exception of the dome, the skylight 10 is generally well known to those skilled in the art. The dome assembly 12 includes a dome 20 and a roof flashing 22. The dome 20, which is new, will be described in greater detail below. The flashing 22 mounts within a building roof R to provide a structural support for the dome 20. The roof flashing 20 includes a curb 24 and an integral flashing flange 26 extending therefrom. The roof flashing 22 is available in a variety of constructions to accommodate shingle roofs, tile roofs, and other selected applications. The diffuser assembly 14 includes a diffuser 30, a ceiling trim ring 32, and a tube/ring seal 34. The diffuser 30 is a prismatic light diffuser. The ceiling trim ring 32 supports the diffuser 30 within the ceiling C. The tube/ring seal 34 fits about the tube assembly 16 as will be described and provides a mechanical interlock between the tube assembly and the diffuser assembly 14. The tube assembly includes upper and lower adjustable tubes 40 and 42, respectively, and an interconnecting adjustable tube 44. The upper adjustable tube 40 fits within the roof flashing 22, and the lower adjustable tube 42 connects to the diffuser assembly 14 by way of the tube/ring seal 34 as will be described. The adjustable tube 44 telescopically interfits with both of the adjustable tubes to accommodate a variety of heights of the roof R above the ceiling C. Additional adjustable tubes 44 can be used as necessary to accommodate unusual heights between the roof and the ceiling. Again, as thus far described, the tubular skylight components are conventional and generally well known to those in the relevant art. The novelty of the present invention resides in the dome 20 to be described hereinafter. The dome 20 is illustrated most clearly in FIGS. 3 and 4. The dome includes a circular base 60 and a generally hemispherical portion 62 extending upwardly therefrom and reaching an apex 63. The base 60 includes steps 64 and 65 that fit over and receive the stepped curb 24 of the roof flashing 22 (see FIG. 2). The second step 65 rests on the top of the curb and is defined by four pairs of fingers 66 located at 90° intervals around the circumference of the base 60. Holes 67 are provided to receive fasteners to secure the dome to the curb. The generally hemispherical dome portion 60 includes an interior surface 70 and an exterior surface 72. The exterior surface includes a prismatic surface or portion 68 and a nonprismatic surface or portion 69. The prismatic portion is illustrated perhaps most clearly in FIG. 3 and includes the patterned surface covering somewhat less than the left half of the dome in a pattern as described below. The interior surface 70 has a radius 72, and the exterior surface 74 has a radius 76 in the nonprismatic portion and a radius 78 in the prismatic portion. The radius 76 is slightly greater than the radius 78. The nonprismatic portion 69 is generally uniform in thickness between the inner surface 70 and the exterior surface 74. The dome portion 60 has an increased thickness in the prismatic portion 68. Because the prismatic surface is uneven (i.e. grooved) the distance between the interior surface and the exterior surface varies. The minimum thickness in the prismatic portion 68 is approximately equal to the thickness in the nonprismatic portion 69, and the maximum thickness in the prismatic portion is approximately twice the thickness in the nonprismatic portion. The shape and configuration of the prismatic portion 68 is perhaps best illustrated in FIG. 3. The prismatic portion 68 includes a plurality of grooves 71 that molded, cut, or otherwise formed in the exterior surface 74. Each of the grooves 71 extends along a great circle passing through the apex 63. Each of the grooves 71 extends from the base 64 to a location short of the apex 63. In the preferred embodiment, 37 first grooves 71 are formed at 4° intervals, and 38 second grooves 71 are formed at 4° intervals offset 2° from the first set of grooves so that each first groove is bracketed by a pair of second grooves. As currently contemplated, the grooves 71 are formed by molding; however, other forming techniques, such as cutting, can be used. The exterior angle between the walls of a groove 71 when using the preferred material is preferably in the range of 86° to 94°, with the most preferred angle being 92°. The groove angles may change with other materials depending on their indices of refraction. The angle is selected so that direct light from the dome interior is reflected by the internal reflection of the prism--not refracted--as it strikes the interior side of the groove walls. The structure and effect of the described technique is disclosed in U.S. Pat. No. 4,839,781, issued Jun. 13, 1989 to Barnes et al, and entitled "Reflector/Refractor." The prismatic portion 68 comprises an angular segment of the hemispherical dome. In the preferred embodiment, this segment is approximately 148° of the 360° circumference. The grooves 71 stopping short of the apex leaves a pie-shaped portion 82 surrounding the apex of the dome that is part of the nonprismatic portion 69 of the exterior surface. The entire dome 20 is fabricated of a single piece of acrylic. The currently preferred material is that sold under the designation V825UVA-5A by Rohm & Haas. For a dome 10 inches in diameter, the dome portion 60 is 0.114 inch thick in the nonprismatic portion and up to 0.204 inch thick in the prismatic portion. Other materials suitable for skylight domes may be used and include polycarbonates and nylons. Other materials may be used if they provide the light transmittance and strength characteristics required in skylight domes. The particular pattern of the prism will depend on the performance desired and the anticipated location of the skylight. The illustrated dome has been designed for use at 40° latitude as representative of a "normal" U.S. location. The pattern follows the highest path of the sun, which of course occurs during the summer. The light reflectance provided by the prismatic portion 68 is perhaps best illustrated in FIG. 5. Each of the grooves 71 provides two apparent reflective surfaces to light rays striking the surfaces from inside the dome because of the high index of refraction. Consequently, light impinging on the grooves 71 from the interior of the dome are reflected back into the interior of the dome. Turning specifically to FIG. 5, a light ray L from the interior of the dome passes through the interior surface 70, then reflects off the surfaces of two grooves 71 to be returned to the dome interior. Consequently, light at low angles which would pass directly through the dome is instead reflected back into the dome interior. The prismatic portion 68 does not significantly block ambient light from passing through the dome. Therefore, the dome does not significantly reduce the amount of ambient light; and the dome does not decrease the amount of direct light passing into the skylight. The only losses (approximately 8% in the preferred material) are due to the material from which the dome is fabricated. Assembly and Operation The tubular skylight 10 is installed within a building in conventional fashion. Vertically aligned holes are cut in the roof R and the ceiling C. The roof flashing 22 is installed in the roof. The upper adjustable tube 40 is fitted within the curb 24 of the roof flashing 22 and slid downwardly until the upper edges of both are aligned. The dome 20 is fitted over the curb 24 (with the upper adjustable tube 40 fitted therein) and secured in position using screws (not shown). The ceiling trim ring 32 is secured to the underside of the ceiling C. The tube/ring seal 34 is placed over the lower adjustable tube 42, and the assembly is pushed into the ceiling trim ring from above the ceiling C. The extension tube 44 is then slid as necessary to a connecting position between the upper and lower adjustable tubes 40 and 42. All seams are taped with duct tape. Finally, the diffuser 30 is installed within the trim ring 32 using a partial-turn coupling. FIGS. 6 and 7 illustrate the functional performance of the new dome 20. Turning first to FIG. 6, the dome 20 and tube assembly 16 are schematically illustrated. Direct light rays 90 are shown entering the skylight at a 50° angle from the horizontal, which is the angle of the sun at 40° latitude and 98° longitude on the vernal and autumnal equinoxes. When the sun is at this angle, virtually all of the direct rays 90 pass through the nonprismatic portion of the dome 20 to enter the skylight 10 in conventional fashion. The reflected rays 90' are illustrated in dotted lines and illustrate how the light is reflected downwardly through the skylight assembly. FIG. 7 illustrates the performance of the skylight dome when the sun is relatively low in the sky. Specifically, the direct sunlight rays 90 arrive at the skylight dome basically on the horizontal. The direct rays 90 pass directly through the nonprismatic portion 69. Without the prismatic portion 68 of the present invention, the direct rays 90 would continue to pass through the skylight dome so that none of those rays would pass downwardly into the tube. Instead, the prismatic portion 68 reflects the direct rays 90 downwardly through the dome at a variety of angles. The reflected rays 90' are illustrated as dashed lines and pass downwardly at a variety of reflected angles. The object of the present invention is to direct light downwardly through the tube at virtually any angle on the premise that all of the downwardly directed light enhances, even in some small fashion, the light exiting the bottom of the tube. Additionally, as can be seen, some of the rays pass directly through the tube without further reflection off the tube wall to the bottom of the tube assembly 16. The present invention greatly enhances the performance of the tubular skylight by directing or steering a larger percentage of the available light downwardly through the tube. The prismatic portion 68 enhances the performance of the skylight tube particularly when the sun is relatively low in the sky as occurs in the morning, the late afternoon, and the winter. The above description is that of a preferred embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents.

A tubular skylight having an improved dome improving the efficiency of the skylight. The dome includes an integral prism in a portion of its outer surface to reflect light downwardly through the skylight. The dome is hemispherical, and the prism includes a plurality of grooves extending along great circles that pass through the apex of the dome. The prism covers only an angular segment of the hemispherical dome; and the grooves stop short of the apex of the dome.

This is a United States patent application being filed under 37 C.F.R. 1.53(b) claiming priority to GB9921396.9 filed Sep. 11, 1999 in the United Kingdom; for which GB0014451.9 was filed Jun. 13, 2000 and GB0018654.4 was filed Jul. 28, 2000 in the United Kingdom. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pharmaceutical formulation for use in the administration of medicaments by inhalation. In particular, this invention relates to a pharmaceutical formulation of fluticasone propionate for use in metered dose inhalers (MDI's). The invention also relates to methods for their preparation and to their use in therapy. 2. Description of the Background Art Inhalers are well known devices for administering pharmaceutically active materials to the respiratory tract by inhalation. Such active materials commonly delivered by inhalation include bronchodilators such as β2 agonists and anticholinergics, corticosteroids, anti-allergics and other materials that may be efficiently administered by inhalation, thus increasing the therapeutic index and reducing side effects of the active material. (6a, 11b, 16a, 17a)-6, 9-difluoro-11-hydroxy-16-methyl-3-oxo-17-(1-oxopropoxy) androsta-1, 4-diene-17-carbothioic acid, S-fluoromethyl ester was described as an anti-inflammatory steroid by U.S. Pat. No. 4,335,121. This compound is also known by the generic name of fluticasone propionate and has since become widely known as a highly effective steroid in the treatment of inflammatory diseases, such as asthma and chronic obstructive pulmonary disease (COPD). Metered dose inhalers (MDI's) are the most common type of a wide range of inhaler types and utilise a liquefied propellant to expel droplets containing the pharmaceutical product to the respiratory tract as an aerosol. MDI formulations are generally characterised as solution formulations or suspension formulations. The most commonly used aerosol propellants for medicaments have been Freon 11 (CCl 3 F) in admixture with Freon 12 (CCl 2 F 2 ) and Freon 114 (CF 2 Cl.CF 2 Cl). However, these propellants are now believed to provoke the degradation of stratospheric ozone and their use is now being phased out to eliminate the use of all CFC containing aerosol propellants. There is thus a need to provide an aerosol formulation for medicaments which employ so called ‘ozone-friendly’ propellants. Hydrofluoroalkanes (HFAs; known also as hydrofluorocarbons or HFCs) contain no chlorine and are considered less destructive to ozone and these are proposed substitutes for CFCs. In particular, 1,1,1,2-tetrafluoroethane (HFA 134a) and 1,1,1,2,3,3,3-heptafluoropropane (HFA 227) have been acknowledged to be the best candidates for non-CFC propellants. The efficiency of an aerosol device, such as an MDI, is a function of the dose deposited at the appropriate site in the lungs. Deposition is affected by several factors, of which one of the most important is the aerodynamic particle size. Solid particles and/or droplets in an aerosol formulation can be characterised by their mass median aerodynamic diameter (MMAD, the diameter around which the mass aerodynamic diameters are distributed equally). Particle deposition in the lung depends largely upon three physical mechanisms: 1. impaction, a function of particle inertia; 2. sedimentation due to gravity; and 3. diffusion resulting from Brownian motion of fine, submicrometer (<1 μm) particles. The mass of the particles determines which of the three main mechanisms predominates. The effective aerodynamic diameter is a function of the size, shape and density of the particles and will affect the magnitude of forces acting on them. For example, while inertial and gravitational effects increase with increasing particle size and particle density, the displacements produced by diffusion decrease. In practice, diffusion plays little part in deposition from pharmaceutical aerosols. Impaction and sedimentation can be assessed from a measurement of the MMAD which determines the displacement across streamlines under the influence of inertia and gravity, respectively. Aerosol particles of equivalent MMAD and GSD (geometric standard deviation) have similar deposition in the lung irrespective of their composition. The GSD is a measure of the variability of the aerodynamic particle diameters. For inhalation therapy there is a preference for aerosols in which the particles for inhalation have a diameter of about 0.5 to 5 μm. Particles which are larger than 5 μm in diameter are primarily deposited by inertial impaction in the orthopharynx, particles 0.5 to 5 μm in diameter, influenced mainly by gravity, are ideal for deposition in the conducting airways, and particles 0.5 to 3 μm in diameter are desirable for aerosol delivery to the lung periphery. Particles smaller than 0.5 μm may be exhaled. Respirable particles are generally considered to be those with aerodynamic diameters less than 5 μm. These particles, particularly those with a diameter of about 3 μm, are efficiently deposited in the lower respiratory tract by sedimentation. It has been recently demonstrated in patients with mild and severe airflow obstruction that the particle size of choice for a β2 agonist or anticholinergic aerosol should be approximately 3 μm (Zaanen, P. et al, Int. J. Pharm. (1994) 107, 211-217, Int. J. Pharm. (1995) 114, 111-115, Thorax (1996), 51, 977-980.) Many of the factors relevant to the MMAD of particles are relevant to droplets and the additional factors of rate of solvent evaporation, and surface tension are also important. In suspension formulations, particle size in principle is controlled during manufacture by the size to which the solid medicament is reduced, usually by micronisation. However, if the suspended drug has the slightest solubility in propellant, a process known as Ostwald Ripening can lead to particle size growth. Also, particles may have tendency to aggregate, or adhere to parts of the MDI eg. canister or valve. The effect of Ostwald ripening and particularly of drug deposition may be particularly severe for potent drugs (including fluticasone propionate) which need to be formulated in low doses. Solution formulations do not suffer from these disadvantages, but suffer from different ones in that particle or droplet size is both a function of rate of evaporation of the propellant from the formulation, and of the time between release of formulation from canister and the moment of inhalation. Thus, it may be subject to considerable variability and is generally hard to control. Besides its impact on the therapeutic profile of a drug, the size of aerosol particles has an important impact on the side effect profile of a drug. For example, it is well known that the orthopharynx deposition of aerosol formulations of steroids can result in side effects such as candidiasis of mouth and throat. Accordingly, throat deposition of such aerosol formulations is generally to be avoided. Furthermore, a higher systemic exposure to the aerosol particles due to deep lung penetration can enhance the undesired systemic effects of certain drugs. For example, the systemic exposure to certain steroids can produce side effects on bone metabolism and growth. SUMMARY OF THE INVENTION Thus, according to the present invention we provide a pharmaceutical aerosol formulation for use in a metered dose inhaler, comprising (i) fluticasone propionate and (ii) a hydrofluoroalkane (HFA) propellant; and characterised in that the fluticasone propionate is completely dissolved in the formulation. DETAILED DESCRIPTION OF THE INVENTION The formulation according to the invention will generally contain a solubilisation agent to aid solubilisation of the fluticasone propionate in the formulation. Suitable solubilisation agents include propylene glycol and ethanol, preferably ethanol. Other suitable solubilisation agents include ethers (eg dimethyl ether). Alkanes may also be of use. A further solubilisation agent of interest is dimethoxymethane (methylal) which has good solvency properties. We have also found ethylacetate to be a solubilising agent with good solvency properties. As a particular aspect of the present invention we provide a pharmaceutical aerosol formulation comprising (i) fluticasone propionate, (ii) a hydrofluoroalkane (HFA) propellant, (iii) a low volatility component to increase the mass median aerodynamic diameter (MMAD) of the aerosol particles on actuation of the inhaler and (iv) a solubilisation agent in sufficient quantity to solubilise the fluticasone propionate in the formulation. The presence of the low volatility component in the solution formulation increases the fine particle mass (FPM) as defined by the content of stages 3-5 of an Andersen Cascade Impactor on actuation of the formulation relative to solutions formulations which omit this component. Solution formulations which omit the higher volatility component generally give rise to a particle size distribution which have a higher content of finer particles; such distributions generally do not match the distribution of the existing commercialised suspension formulations which contain CFC's and may therefore not be bio-equivalent. Examples of HFA propellants include 1,1,1,2-tetrafluoroethane (HFA134a) and 1,1,1,2,3,3,3-heptafluoro-n-propane (HFA227) and mixtures thereo'. The preferred propellant is 1,1,1,2-tetrafluoroethane (HFA134a). An alternative propellant of interest is 1,1,1,2,3,3,3-heptafluoro-n-propane (HFA227). The preferred low volatility component is glycerol, propylene glycol or polyethyleneglycol (eg PEG 200 or PEG 400), especially glycerol. Polyethylene glycol is also of particular interest, especially PEG400. Preferably it is present in an amount of 0.5 to 3% (w/w), especially around 1% (w/w). The preferred solubilisation agent is ethanol. More specifically, the present invention can be defined as a pharmaceutical aerosol formulation which comprises: (i) fluticasone propionate; (ii) 1,1,1,2-tetrafluoroethane (HFA 134a); (iii) 0.5-3% (w/w) glycerol; and (iv) a solubilisation agent (particularly ethanol) in sufficient quantity to solubilise the fluticasone propionate in the formulation. We prefer the formulation to be suitable for delivering a therapeutic amount of fluticasone propionate in one or two actuations. Preferably, the formulation will be suitable for delivering 25-250 μg per actuation, especially 25 μg, 50 μg, 125 μg or 250 μg per actuation. However, as mentioned in the foregoing, the amount of ethanol required to dissolve high concentrations of fluticasone propionate may tend to depress the vapour pressure of the propellant to an undesirable degree. The vapour pressure should desirably remain above around 50 psi. Therefore the formulation is most suitable for delivering 25-125 μg per actuation, especially 25-50 μg per actuation. The formulation according to the invention will be used in association with a suitable metering valve. We prefer that the formulation is actuated by a metering valve capable of delivering a volume of between 50 μl and 100 μl, eg 50 μl or 63 μl. 100 μl is also suitable. When a 50 μl metering volume is used, the final concentration of fluticasone propionate delivered per actuation would be 0.1% w/v (which equates to 0.1 g of fluticasone propionate per 100 ml of formulation) or approx. 0.083% w/w (which equates to 0.083 g of fluticasone propionate per 100 g of formulation) for a 50 μg dose, 0.25% (w/v) or approx. 0.21% (w/w) for a 125 μg dose, 0.5% (w/v) or approx. 0.42% (w/w) for a 250 μg dose and 0.05% (w/v) or approx 0.042% (w/w) for a 25 μg dose. Wherein a 63 μl metering volume is used, the final concentration of fluticasone propionate delivered per actuation would be 0.079% (w/v) or approx. 0.067% (w/w) for a 50 μg dose, 0.198% (w/v) or approx. 0.167% (w/w) for a 125 μg dose, 0.397% (w/v) or approx. 0.333% (w/w) for a 250 μg dose and 0.04% (w/v) or approx. 0.033% (w/w) for a 25 μg dose. When a 100 μl metering volume is used, the final concentration of fluticasone propionate delivered per actuation would be 0.05% w/v (which equates to 0.05 g of fluticasone propionate per 100 ml of formulation) or approx. 0.042% w/w (which equates to 0.042 g of fluticasone propionate per 100 g of formulation) for a 50 g dose, 0.125% (w/v) or approx. 0.11% (w/w) for a 125 μg dose, 0.25% (w/v) or approx. 0.21% (w/w) for a 250 μg dose and 0.025% (w/v) or approx 0.021% (w/w) for a 25 μg dose. The previously quoted w/w figures are approximate in that they do not compensate in the mismatch in density between HFA134a and ethanol, however the precise figures may be readily determined. The formulation is most suitable for concentrations of fluticasone propionate in the range 0.025 to 0.25% (w/v), preferably 0.025 to 0.15% (w/v), more preferably 0.035 to 0.15% (w/v), particularly 0.04 to 0.1% (w/v). A concentration of 0.025 to 0.04% (w/v) is also of particular interest. Formulations of the present invention containing such low concentrations of fluticasone propionate may have particular physical stability advantages relative to suspension formulations containing the same wherein particles of fluticasone propionate may be susceptible to Ostwald ripening or to drug deposition on the canister wall or on parts of the valve as discussed above. Drug deposition is especially problematic in low strength fluticasone propionate suspension formulations because the amount of drug lost through deposition on internal surfaces of the metered dose inhaler can represent a significant proportion of the total available drug and therefore have a significant effect on dosing uniformity through the life of the product. The solution formulations of the present invention overcome or substantially mitigate such disadvantages. Use of a larger metering chamber eg 100 μl will generally be preferred. We prefer the formulation to contain between 0.5 and 2% w/w, more preferably between 0.8 and 1.6% w/w, particularly between 1.0 and 1.6% w/w glycerol. Another range of particular interest is 0.5-1% (w/w) glycerol. We especially prefer to use 1.3% (w/w) glycerol. We also especially prefer to use 1.0% w/w glycerol. Depending on the final concentration of fluticasone propionate in the formulation, the propellant, and the precise amount of low volatility component, the concentration of solubilisation agent (eg ethanol) required will vary. So as not to suppress the vapour pressure of the propellant to an undesirable extent, the amount of ethanol should preferably not exceed around 35%. The amount of ethanol will more preferably be in the range 5 to 30%, particularly 5 to 20%, more particularly 10 to 20%. A range of 7 to 16% wow is also particularly preferred, more particularly 7 to 11% w/w. When the concentration of fluticasone propionate is around 0.1% w/v and the propellant is 1,1,1,2-tetrafluoroethane, an amount of ethanol of 16-24% w/w eg 16-18% w/w, especially around 16% w/w is particularly suitable but is more preferably 20-22% w/w especially around 21% w/w. When the concentration of fluticasone propionate is around 0.05% w/v and the propellant is 1,1,1,2-tetrafluoroethane, an amount of ethanol of 7-11% w/w eg 7-8% w/w, especially around 7% w/w is particularly suitable but is more preferably 9-11% w/w especially around 10% w/w. When the concentration of fluticasone propionate is around 0.079% w/v and the propellant is 1,1,1,2-tetrafluoroethane, an amount of ethanol of 15-17% w/w especially around 16% is suitable. When the concentration of fluticasone propionate is around 0.198% w/v and the propellant is 1,1,1,2-tetrafluoroethane, an amount of ethanol of 34-36% w/w eg around 35% is suitable. When the concentration of fluticasone propionate is around 0.025% w/v and the propellant is 1,1,1,2-tetrafluoroethane, an amount of ethanol of 7-9% w/w especially around 8%, more preferably around 7% is suitable. When the concentration of fluticasone propionate is around 0.0250% w/v and the propellant is 1,1,1,2,3,3,3-heptafluoro-n-propane, an amount of ethanol of 13-15% w/w especially around 14% is suitable. When the concentration of fluticasone propionate is around 0.05% w/v and the propellant is 1,1,1,2,3,3,3-heptafluoro-n-propane, an amount of ethanol of 17-19% w/w especially around 18% is suitable. When the concentration of fluticasone propionate is around 0.05% w/v and the propellant is 1,1,1,2-tetrafluoroethane, an amount of ethylacetate as solubilisation agent of 13-16% w/w especially around 15% is suitable. When the concentration offluticasone propionate is around 0.05% w/v and the propellant is 1,1,1,2-tetrafluoroethane, an amount of dimethoxymethane (methylal) as solubilisation agent of 13-16% w/w especially around 15% is suitable. The above generally described formulations are particularly preferred in conjunction with 1.0-1.6% w/w glycerol, particularly 1.0% w/w glycerol or 1.3% w/w glycerol. Formulations according to the invention which are free of surfactants are preferred. Formulations according to the invention which are free of all excipients besides the solubilisation agent (eg ethanol), low volatility component (such as glycerol) and the propellant are particularly preferred. Formulations according to the invention will preferably contain fluticasone propionate as the only medicament. However formulations which contain medicaments in addition to fluticasone propionate such as beta adrenergic agonists and anti-cholinergic compounds may also be contemplated. The pharmaceutical composition according to the present invention may be filled into canisters suitable for delivering pharmaceutical aerosol formulations. Canisters generally comprise a container capable of withstanding the vapour pressure of the HFA propellant, such as plastic or plastic-coated glass bottle or preferably a metal can, for example an aluminium can which may optionally be anodised, lacquer-coated and/or plastic-coated, which container is closed with a metering valve. It may be preferred that canisters be coated with a fluorocarbon polymer as described in WO 96/32151, for example, a co-polymer of polyethersulphone (PES) and polytetrafluoroethylene (PTFE). Another polymer for coating that may be contemplated is FEP (fluorinated ethylene propylene). The metering valves are designed to deliver a metered amount of the formulation per actuation and incorporate a gasket to prevent leakage of propellant through the valve. The gasket may comprise any suitable elastomeric material such as for example low density polyethylene, chlorobutyl, black and white butadiene-acrylonitrile rubbers, butyl rubber and neoprene. Thermoplastic elastomer valves as described in WO92/11190 and valves containing EPDM rubber as described in WO95/02651 are especially suitable. Suitable valves are commercially available from manufacturers well known in the aerosol industry, for example, from Valois, France (eg. DF10, DF30, DF60), Bespak pic, UK (eg. BK300, BK356, BK357) and 3M-Neotechnic Ltd, UK (eg. Spraymiser™). The DF31 valve of Valois, France is also suitable. Valve seals, especially the gasket seal, and also the seals around the metering chamber, will preferably be manufactured of a material which is inert to and resists extraction into the contents of the formulation, especially when the contents include ethanol. Valve materials, especially the material of manufacture of the metering chamber, will preferably be manufactured of a material which is inert to and resists distortion by contents. of the formulation, especially when the contents include ethanol. Particularly suitable materials for use in manufacture of the metering chamber include polyesters eg polybutyleneterephthalate (PBT) and acetals, especially PBT. Materials of manufacture of the metering chamber and/or the valve stem may desirably be fluorinated, partially fluorinated or impregnated with fluorine containing substances in order to resist drug deposition. Valves which are entirely or substantially composed of metal components (eg Spraymiser, 3M-Neotechnic) are especially preferred for use according to the invention. Conventional bulk manufacturing methods and machinery well known to those skilled in the art of pharmaceutical aerosol manufacture may be employed for the preparation of large scale batches for the commercial production of filled canisters. Thus, for example, in one bulk manufacturing method a metering valve is crimped onto an aluminium can to form an empty canister. The medicament is added to a charge vessel and a mixture of ethanol, low volatility component and liquefied propellant is pressure filled through the charge vessel into a manufacturing vessel. An aliquot of the formulation is then filled through the metering valve into the canister. Typically, in batches prepared for pharmaceutical use, each filled canister is check-weighed, coded with a batch number and packed into a tray for storage before release testing. In an alternative process, an aliquot of the liquified formulation is added to an open canister under conditions which are sufficiently cold that the formulation does not vaporise, and then a metering valve crimped onto the canister. In an alternative process an aliquot of medicament dissolved in the solubilising agent and any low-volatility component is dispensed into an empty canister, a metering valve is crimped on, and then the propellant is filled into the canister through the valve. Typically, in batches prepared for pharmaceutical use, each filled canister is check-weighed, coded with a batch number and packed into a tray for storage before release testing. Each filled canister is conveniently fitted into a suitable channelling device prior to use to form a metered dose inhaler for administration of the medicament into the lungs or nasal cavity of a patient. Suitable channelling devices comprise, for example a valve actuator and a cylindrical or cone-like passage through which medicament may be delivered from the filled canister via the metering valve to the nose or mouth of a patient eg. a mouthpiece actuator. In a typical arrangement the valve stem is seated in a nozzle block which has an orifice leading to an expansion chamber. The expansion chamber has an exit orifice which extends into the mouthpiece. Actuator (exit) orifice diameters in the range 0.15-0.45 mm particularly 0.2-0.45 mm are generally suitable eg 0.15, 0.22, 0.25, 0.30, 0.33 or 0.42 mm. We have found that it is advantageous to use a small diameter eg 0.25 mm or less, particularly 0.22 mm since this tends to result in a higher FPM and lower throat deposition. 0.15 mm is also particularly suitable. The dimensions of the orifice should not be so small that blockage of the jet occurs. Actuator jet lengths are typically in the range 0.30-1.7 mm eg 0.30, 0.65 or 1.50 mm. Smaller dimensions are preferred eg 0.65 mm or 0.30 mm. Metered dose inhalers are designed to deliver a fixed unit dosage of medicament per actuation or ‘puff’, for example in the range of 25 to 250 μg medicament per puff. Administration of medicament may be indicated for the treatment of mild, moderate or severe acute or chronic symptoms or for prophylactic treatment. Treatment may be of asthma, chronic obstructive pulmonary disease (COPD) or other respiratory disorder. It will be appreciated that the precise dose administered will depend upon the age and condition of the patient, the quantity and frequency of administration will ultimately be at the discretion of the attendant physician. Typically, administration may be one or more times, for example from 1 to 8 times per day, giving for example 1,2,3 or 4 puffs each time. The preferred treatment regime is 1 or 2 puffs of 25, 50, 125 or 250 μg/puff fluticasone propionate, 2 times per day. The filled canisters and metered dose inhalers described herein comprise further aspects of the present invention. A still further aspect of the present invention comprises a method of treating respiratory disorders such as, for example, asthma or chronic obstructive pulmonary disease (COPD), which comprises administration by inhalation of an effective amount of a formulation herein before described. A further aspect of the present invention comprises the use of a formulation herein before described in the manufacture of a medicament for the treatment of respiratory disorders, eg. asthma or chronic obstructive pulmonary disease (COPD). As mentioned above the advantages of the invention include the fact that formulations according to the invention may be more environmentally friendly, more stable, less susceptible to Oswald ripening or drug deposition onto internal surfaces of a metered dose inhaler, have better dosing uniformity, deliver a higher FPM, give lower throat deposition, be more easily or economically manufactured, or may be otherwise beneficial relative to known formulations. The invention is illustrated with reference to the following examples: EXAMPLES 1 AND 2 Formulations may be prepared with compositions as follows: Fluticasone propionate: 0.1% w/v 0.05% w/v Ethanol: 16% w/w 7% Glycerol: 1.3% w/w 1.3% 1, 1, 1, 2-tetrafluoroethane: to 100% to 100% These solution formulations may be filled into an aluminium canister under pressure and fitted with a metering valve having a 50 μl metering chamber. These formulations are suitable for delivering 50 μg or 25 μg fluticasone propionate per actuation respectively. EXAMPLE 3 Formulations were prepared with compositions as follows: Form. 3a Form. 3b Form. 3c Fluticasone propionate: 0.1% w/v 0.079% w/v 0.05% w/v Ethanol: 21% w/w 16% w/w 10% Glycerol: 1.0% w/w 1.0% w/w 1.0% 1, 1, 1, 2-tetrafluoroethane: to 100% to 100% to 100% These solution formulations were filled into aluminium canisters (120 actuations/canister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chambers of volume 50 μl, 63 μl and 100 μl respectively. These formulations are suitable for delivering 50 μg fluticasone propionate per actuation. EXAMPLE 4 Formulations were prepared with compositions as follows: Form. 4a Form. 4b Form. 4c Fluticasone propionate: 0.1% w/v 0.079% w/v 0.05% w/v Ethanol: 21% w/w 16% w/w 10% 1, 1, 1, 2-tetrafluoroethane: to 100% to 100% to 100% These solution formulations were filled into aluminium canisters (120 actuations/canister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chambers of volume 50 μl, 63 μl and 100 μl respectively. These formulations are suitable for delivering 50 μg fluticasone propionate per actuation. EXAMPLE 5 A formulation was prepared with compositions as follows: Fluticasone propionate: 0.198% w/v Ethanol: 35% w/w Glycerol: 1.0% w/w 1,1,1,2-tetrafluoroethane: to 100% This solution formulation was filled into an aluminium canisters (120 actuations/canister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chamber of volume 63 μl. This formulation is suitable for delivering 125 μg fluticasone propionate per actuation. EXAMPLE 6 A formulation was prepared with compositions as follows: Fluticasone propionate: 0.198% w/v Ethanol: 35% w/w 1,1,1,2-tetrafluoroethane: to 100% This solution formulation was filled into an aluminium canisters (120 actuations/canister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chamber of volume 63 1 μl. This formulation is suitable for delivering 125 μg fluticasone propionate per actuation. EXAMPLE 7 Formulations were prepared with compositions as follows: Form. 7a Form. 7b Form. 7c Fluticasone propionate: 0.05% w/v 0.05% w/v 0.05% w/v Ethanol: 10% w/w 10% w/w 10% w/w Glycerol: 0.5% w/w 2% w/w 3% w/w 1, 1, 1, 2-tetrafluoroethane: to 100% to 100% to 100% These solution formulations were filled into aluminium canisters (120 actuations/canister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chamber of volume 100 μl. These formulations are suitable for delivering 50 μg fluticasone propionate per actuation. EXAMPLE 8 Formulations were prepared with compositions as follows: Fluticasone propionate: 0.025% w/v 0.025% w/v Ethanol: 8% w/w 7% w/w Glycerol: 1.0% w/w 1.0% w/w 1, 1, 1, 2-tetrafluoroethane: to 100% to 100% These solution formulations were filled into an aluminium canisters (120 actuations/canister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chamber of volume 100 μl. These formulations are suitable for delivering 25 μg fluticasone propionate per actuation. EXAMPLE 9 Formulations were prepared with compositions as follows: Formulation 9a: Fluticasone propionate: 0.05% w/v Dimethoxymethane: 15% w/w 1,1,1,2-tetrafluoroethane: to 100% Formulation 9b: Fluticasone propionate: 0.05% w/v Ethylacetate: 15% w/w 1,1,1,2-tetrafluoroethane: to 100% Formulation 9c: Fluticasone propionate: 0.05% w/v Dimethoxymethane: 15% w/w Glycerol: 1% w/w 1,1,1,2-Letrafluoroethane: to 100% Formulation 9d: Fluticasone propionate: 0.05% w/v Ethylacetate: 15% w/w Glycerol: 1% w/w 1,1,1,2-tetrafluoroethane: to 100% These solution formulations were filled into aluminium canisters (120 actuations/canister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chamber of volume 100 μl. These formulations are suitable for delivering 50 μg fluticasone propionate per actuation. EXAMPLE 10 Formulations were prepared with compositions as follows: Formulation 10a: Fluticasone propionate: 0.05% w/v Ethanol: 10% w/w Glycerol: 1%w/w 1,1,1,2-tetrafluoroethane: to 100% Formulation 10b: Fluticasone propionate: 0.05% w/v Ethanol: 10% w/w PEG 200: 1% w/w 1,1,1,2-tetrafluoroethane: to 100% Formulation 10c: Fluticasone propionate: 0.05% w/v Ethanol: 10% w/w PEG 400: 1%w/w 1,1,1,2-tetrafluoroethane: to 100% Formulation 10d: Fluticasone propionate: 0.05% w/v Ethanol: 10% w/w Propylene glycol: 1% w/w 1,1,1,2-tetrafluoroethane: to 100% Formulation 10e: Fluticasone propionate: 0.05% w/v Ethanol: 18% w/w 1,1,1,2,3,3,3-heptafluoro-n-propane: to 100% Formulation 10f: Fluticasone propionate: 0.05% w/v Ethanol: 18% w/w Glycerol: 1% w/w 1,1,1,2,3,3,3-heptafluoro-n-propane: to 100% Formulation 10g: Fluticasone propionate: 0.025% w/v Ethanol: 14% w/w 1,1,1,2,3,3,3-heptafluoro-n-propane: to 100% Formulation 10h: Fluticasone propionate: 0.025% w/v Ethanol: 14% w/w Glycerol: 1% w/w 1,1,1,2,3,3,3-heptafluoro-n-propane: to 100% Formulation 10i: Fluticasone propionate: 0.025% w/v Ethanol: 7% w/w 1,1,1,2-tetrafluoroethane: to 100% Formulation 10j: Fluticasone propionate: 0.025% w/v Ethanol: 7% w/w Glycerol: 1% w/w 1,1,1,2-tetrafluoroethane: to 100% These solution formulations were filled into aluminium canisters (120 actuations/canister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chamber of volume 63 μl. These formulations are suitable for delivering 31.5 μg (10a-10e) or 15.75 μg (10f,10g) fluticasone propionate per actuation. However the performance of these formulations is a model for formulations that would deliver 50 μg and 25 μg fluticasone propionate using a metering valve of 100 μl. Andersen Cascade Impaction Data Formulations as described in Examples 3, 4, 5 and 6 were profiled using an Andersen Cascade Impactor, using a 0.22 mm (orifice)×0.65 mm O(et length) actuator from Bespak (BK621 variant). Testing was performed on canisters at “beginning of use” (BoU) and delivered drug from 10 actuations was collected in the instrument after 4 priming actuations were fired to waste. Results are shown in Tables 1-4 and FIGS. 1-4 and 11. For comparison, data from a Flixotide Evohaler (trademark) (particulate fluticasone propionate suspensed in HFA134a (excipient free) 50 μg per actuation) product is also shown in some figures. The 0.079% w/v fluticasone propionate products of Examples 3 and 4 (50 μg per actuation; 63 μl metering chamber) were profiled using an Andersen Cascade Impactor in a study to see the effect of actuator orifice diameter and length. Three actuators were used: 0.50 mm diameter orifice×1.50 mm jet length 0.33 mm diameter orifice×1.50 mm jet length 0.22 mm diameter orifice×0.65 mm jet length Results are shown in Table 5 and FIGS. 5 to 9 . For comparison, data from a Flixotide Evohaler (trademark) (particulate fluticasone propionate suspensed in HFA134a (excipient free) 50 μg per actuation) product is also shown in some figures. The results show the best performance (as indicated by highest FPM) in products containing a relatively low concentration of ethanol (say around 10%) and containing glycerol (say around 1%). A small actuator orifice diameter (say around 0.22 mm) is also seen to be preferred. The solubility of fluticasone propionate in ethanol in the presence of HFA134a is shown in FIG. 10 . A study was performed on the 0.05% w/v fluticasone propionate formulations (HFA134a/10% ethanol) of Examples 3 (Formulation 3c), 4(Formulation 4c) and 7 (Formulations 7a, 7b and 7c) with a 0.22 mm×0.65 mm actuator using an Andersen Cascade Impactor to consider the effect of glycerol content on the following properties: (i). MMAD, (ii) throat deposition, and (iii) stage 3-7 deposition. The results are shown in FIGS. 12-14 . For maximum deposition in the desired region without excessive throat deposition the optimal glycerol concentration appears to be around 0.8-1.6% w/w, particularly 1.0-1.6% w/w. A study was performed using an Andersen Cascade Impactor to compare the properties of formulations containing different solubilising agents. An actuator of dimensions 0.22 mm×0.65 mm was used for the study. The results of the analysis of the formulations of Example 9 Formulations 9a, 9b, 9c and 9d and a comparison with the formulations of Example 3 Formulation 3c and Example 4 Formulation 4c are shown in Table 6 and FIG. 15 . The ethanol with glycerol profile clearly appears the most attractive since it demonstrates the highest FPM content in view of the high dosing in stages 4 and 4 relative to the other profiles. Nevertheless the methylal profiles also looked of significant interest in view of the very low throat deposition. The addition of 1% glycerol shifted the methylal profile to lower stages only to a small extent, perhaps in view of its greater volatility than ethanol. A higher percentage of glycerol would be expected to increase the magnitude of the shift. A study was performed using an Andersen Cascade Impactor to compare the properties of formulations containing different low volatility components. An actuator of dimensions 0.22 mm×0.65 mm was used for the study. The results of the analysis of the formulations of Example 10 Formulations 10a to 10d are shown in Table 7 and FIG. 16 . Particularly good profiles are shown by glycerol and PEG400 which demonstrate relatively low throat deposition and high dosing in stages 4 and 5. A study was performed using an Andersen Cascade Impactor to study the properties of 0.05% fluticasone propionate formulations containing 1,1,1,2,3,3,3-heptafluoro-n-propane (HFA227) as propellant. An actuator of dimensions 0.22 mm×0.65 mm was used for the study. The results of the analysis of the formulations of Example 10 Formulations 10e and 10f are shown in Table 8 and FIG. 17 . Comparison with the HFA134a aerosol formulation of Formulation 10a is shown. A study was performed using an Andersen Cascade Impactor to study the properties of 0.025% fluticasone propionate formulations containing 1,1,1,2-tetrafluoroethane (HFA134a) or 1,1,1,2,3,3,3-heptafluoro-n-propane (HFA227) as propellant. An actuator of dimensions 0.22 mm×0.65 mm was used for the study. The results of the analysis of the formulations of Example 10 Formulations log to 10j are shown in Table 9 and FIGS. 18 and 19. The HFA134a product with ethanol shows a particularly attractive profile eg as shown by a high total delivered dose and a relatively low throat deposition. BRIEF DESCRIPTION OF THE DRAWINGS Table 1: Effect of valve on FPM in fluticasone propionate HFA134a solution aerosols (50 μg/actuation) Table 2: Effect of different levels of ethanol on FPM in fluticasone propionate/HFA134a solution aerosols Table 3: Effect of different levels of ethanol on FPM in fluticasone propionate/HFA134a solution aerosols (valve size effect ignored) Table 4: Cascade impaction analysis of fluticasone propionate/HFA134a solution aerosols (125 μg/actuation) containing 35% ethanol or 35% ethanol and 1% glycerol Table 5: Cascade impaction analysis of fluticasone propionate/HFA134a solution aerosols (50 μg/actuation) containing 16% ethanol or 16% ethanol and 1% glycerol Table 6: Cascade impaction analysis of fluticasone propionate/HFA134a solution aerosols (50 μg/actuation) containing various solubiling agents with and without 1% glycerol Table 7: Cascade impaction analysis of fluticasone propionate/HFA134a solution aeroscis (50 μg /actuation) containing various low volatility components Table 8: Cascade impaction analysis of fluticasone propionate solution aerosols (50 μg/actuation) containing various propellants Table 9: Cascade impaction analysis of fluticasone propionate solution aerosols (25 μg/actuation) containing various propellants FIG. 1 : Effect of valve size and glycerol on FPM in fluticasone propionate solution aerosols in HFA134a (50 μg/actuation) FIG. 2 : Effect of level of ethanol on FPM in various fluticasone propionate/HFA134a solution aerosols with no addition of glycerol FIG. 3 : Effect of level of ethanol on FPM in various fluticasone propionate/HFA134a solution aerosols with addition of 1% glycerol FIG. 4 : Effect of glycerol on FPM in fluticasone propionate 125 μg/HFA134a solution aerosols containing 35% ethanol or 35% ethanol and 1% glycerol FIG. 5 : Effect of actuator dimensions on FPM and throat in fluticasone propionate/HFA134a solution aerosols (50 μg/actuation) containing 16% ethanol FIG. 6 : Effect of actuator dimensions on FPM and throat in fluticasone propionate/HFA134a solution aerosols (50 μg/actuation) containing 16% ethanol and 1% ethanol FIG. 7 : The effect of addition of glycerol on FPM in fluticasone propionate 50 g/HFA134a solution aerosols containing 16% ethanol or 16% ethanol and 1% glycerol (0.22 mm diameter actuator orifice) FIG. 8 : The effect of addition of glycerol on FPM in fluticasone propionate 50 μg/HFA134a solution aerosols containing 16% ethanol or 16% ethanol and 1% glycerol (0.33 mm diameter actuator orifice) FIG. 9 : Effects of addition of glycerol and actuator dimensions on FPM in fluticasone propionate 50μg/HFA134a solution aerosols containing 16% ethanol or 16% ethanol and 1% glycerol (all actuator variants) FIG. 10 : Solubility of fluticasone propionate in ethanol/HFA134a FIG. 11 : Effects of addition of glycerol and actuator dimensions on FPM in fluticasone propionate 50 μg/HFA134a solution aerosols containing 10% ethanol or 10% ethanol and 1% glycerol FIG. 12 : Effects of addition of glycerol on MMAD in fluticasone propionate 50 μg/HFA134a solution aerosols containing 10% ethanol FIG. 13 : Effects of addition of glycerol on throat deposition in fluticasone propionate 50μg/HFA134a solution aerosols containing 10% ethanol FIG. 14 : Effects of addition of glycerol on stage 3-7 deposition in fluticasone propionate 50 μg/HFA134a solution aerosols containing 10% ethanol FIG. 15 : Cascade impaction analysis of fluticasone propionate/HFA134a solution aerosols (50 μg/actuation) containing ethanol, methylal or ethylacetate as solubilising agent, with and without 1% glycerol FIG. 16 : Cascade impaction analysis of fluticasone propionate/HFA134a solution aerosols (50 μg/actuation) containing various low volatility components and 10% ethanol FIG. 17 : Cascade impaction analysis of fluticasone propionate/HFA227 solution aerosols (50 μg actuation) containing 18% ethanol with and without 1% glycerol and comparison with HFA134a aerosol FIG. 18 : Cascade impaction analysis of fluticasone propionate in HFA227 or HFA134a solution aerosols (25 μg actuation) containing ethanol FIG. 19 : Cascade impaction analysis of fluticasone propionate in HFA227 or HFA134a solution aerosols (25 μg actuation) containing ethanol and 1% glycerol Throughout the specification and the claims which follow, unless the context requires otherwise, the word ‘comprise’, and variations such as ‘comprises’ and ‘comprising’, will be understood to imply the inclusion of a stated integer or step or group of integers but not to the exclusion of any other integer or step or group of integers or steps. Above mentioned patents and patent applications are hereinbefore incorporated by reference. Abbreviations FPM fine particle mass FP fluticasone propionate m/c metering chamber BoU beginning of use PEG polyethyleneglycol Form. Formulation MMAD mass median aerodynamic diameter TABLE 1 The effect of valve on FPM in FP50 μg solution aerosols All data generated with 0.22 mm actuator, except HFA134a suspension product tested with 0.50 mm actuator μg Resuts Cascade Impaction Formulation Ethanol only Ethanol and 1% glycerol HFA134a* Ethanol conc. 10% w/w 16% w/w 21% w/w 10% w/w 16% w/w 21% w/w — Valve size 100 μl 63 μl 50 μl 100 μl 63 μl 50 μl 50 μl Product FP FP FP FP FP FP FP Product strength 50 μg 50 μg 50 μg 50 μg 50 μg 50 μg 50 μg Device 5.7 4.3 5.3 5.2 4.1 5.2 6.6 Throat 12.7  15.2  21.2  16.0  17.1  23.1 13.5  Stage 0 4.5 2.2 2.8 3.4 3.1 2.9 1.6 Stage 1 0.3 0.3 0.3 0.7 0.5 0.6 0.8 Stage 2 0.2 0.2 0.2 1.1 0.9 0.8 1.1 Stage 3 0.3 0.2 0.3 5.4 3.9 3.8 3.2 Stage 4 0.9 0.6 1.0 7.6 5.9 5.2 9.8 Stage 5 9.8 6.5 7.0 8.5 7.3 5.3 11.2  Stage 6 8.6 6.8 5.6 2.4 1.6 1.6 1.4 Stage 7 5.5 3.4 2.8 1.4 1.0 0.8 0.3 Filter 4.7 2.7 2.1 0.9 0.7 0.5 0.2 Total 53.2  42.4  48.6  52.6  46.1  49.8  48.0  Total ex-device 47.5  38.1  43.3  47.4  42.0  44.6  43.3  FPM, St3 + St4 + St5 11.0  7.3 8.3 21.5  17.1  14.3  15.7  FPM, St5 + St6 + St7 23.9  16.7  15.4  12.3  9.9 7.7 8.8 *Flixotide Evohaler suspension formulation TABLE 2 Effect of different levels of Ethanol on FPM in FP/HFA134a solution aerosols All fitted with 63 μl m/c and tested with 0.22 mm actuator % Results Cascade Impaction Formulation Ethanol only Ethanol and 1% glycerol Ethanol conc. 16% w/w 35% w/w 16% w/w 35% w/w Valve size 63 μl 63 μl 63 μl 63 μl Product FP FP FP FP Product strength 50 μg 125 μg 50 μg 125 μg Device 10.1 12.1 8.6 12.6 Throat 35.8 62.6 38.8 63.1 Stage 0 5.2 6.5 6.3 5.8 Stage 1 0.7 0.0 1.0 1.0 Stage 2 0.5 0.0 1.7 1.0 Stage 3 0.5 0.9 8.2 2.9 Stage 4 1.4 1.9 12.6 4.9 Stage 5 15.3 6.5 15.9 4.9 Stage 6 16.0 4.7 3.3 1.9 Stage 7 8.0 1.9 2.1 1.0 Filter 6.4 2.8 1.4 1.0 Total 100.0 100.0 100.0 100.0 Total ex-device 89.9 87.9 91.4 87.4 FPM St3 + St4 + St5 17.2 9.3 36.7 12.6 FPM, St5 + St6 + St7 39.3 13.1 21.3 7.8 TABLE 3 Effect of different levels of Ethanol on FPM in FP/HFA134a solution aerosols (valve size effect ignored) All tested with 0.22 mm actuator, except HFA134a suspension product tested with 0.50 mm actuator % Results Cascade Impaction Formulation Ethanol only Ethanol and 1% glycerol HFA134a* Ethanol conc. 10% w/w 16% w/w 21% w/w 35% w/w 10% w/w 16% w/w 21% w/w 35% w/w — Valve size 100 μl 63 μl 50 μl 63 μl 100 μl 63 μl 50 μl 63 μl 50 μl Product FP FP FP FP FP FP FP FP FP Product strength 50 μg 50 μg 50 μg 125 μg 50 μg 50 μg 50 μg 125 μg 50 μg Device 10.7 10.1 10.9 12.1 9.9 8.6 10.4 12.6 13.3 Throat 23.9 35.8 43.6 62.6 30.4 38.8 46.4 63.1 27.2 Stage 0 8.5 5.2 5.8 6.5 6.5 6.3 5.8 5.8 3.2 Stage 1 0.6 0.7 0.6 0.0 1.3 1.0 1.2 1.0 1.6 Stage 2 0.4 0.5 0.4 0.0 2.1 1.7 1.6 1.0 2.2 Stage 3 0.6 0.5 0.6 0.9 10.3 8.2 7.6 2.9 6.4 Stage 4 1.7 1.4 2.1 1.9 14.4 12.6 10.4 4.9 19.7 Stage 5 18.4 15.3 14.4 6.5 16.2 15.9 10.6 4.9 22.5 Stage 6 16.2 16.0 11.5 4.7 4.6 3.3 3.2 1.9 2.8 Stage 7 10.3 8.0 5.8 1.9 2.7 2.1 1.6 1.0 0.6 Filter 8.8 6.4 4.3 2.8 1.7 1.4 1 1.0 0.4 Total 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100 Total ex-device 89.3 89.8 89.1 87.8 90.1 91.3 89.6 87.4 86.7 FPM, St3 + St4 + St5 20.7 17.2 17.1 9.3 40.9 36.7 28.6 12.7 48.7 FPM, St5 + St6 + St7 44.9 39.3 31.7 13.1 23.5 21.3 15.4 7.8 25.9 *Flixotide Evohaler Suspension Formulation TABLE 4 Cascade Impaction analysis of FP/HFA134a 125 μg solution aerosols containing 35% ethanol or 35% ethanol and 1% glycerol (0.22 mm actuator 63 μl m/c Valois valve) Formulation Ethanol only Ethanol and glycerol Stage of Use BoU (act. 1-10) BoU (act. 1-10) Sample ID FP125/A3/1 FP125/A3/1 Mean FP125/A3/1 FP125/A3/2 Mean Device 13.6 10.7 12.2 14.4 10.9 12.7 Throat 59.2 73.9 66.6 64.7 64.4 64.6 Stage 0 6.8 6.9 6.9 5.6 5.9 5.8 Stage 1 0.5 0.3 0.4 0.5 0.5 0.5 Stage 2 0.3 0.1 0.2 0.6 0.8 0.7 Stage 3 0.5 0.4 0.5 2.4 2.6 2.5 Stage 4 2.2 1.7 2.0 4.8 5.0 4.9 Stage 5 8.5 6.1 7.3 5.5 5.0 5.3 Stage 6 5.2 4.1 4.7 2.0 1.7 1.9 Stage 7 2.4 1.8 2.1 1.1 0.8 1.0 Filter 2.1 2.7 2.4 0.7 0.5 0.6 Total 101.3 108.7 105.0 102.3 98.1 100.2 Tota ex-device 87.7 98.0 92.9 87.9 87.2 87.6 FPM, St3 + St4 + St5 11.2 8.2 9.7 12.7 12.6 12.7 FPM, St5 + St6 + St7 16.1 12.0 14.1 8.6 7.5 8.1 All means, Totals and FPMs were calculated by Excel on rounded individual data A3 = Actuator 0.22 mm × 0.65 mm TABLE 5 Cascade Impaction analysis of FP/HFA134a 50 μg solution aerosols containing 16% ethanol or 16% ethanol and 1% glycerol (63 μl m/c Valois valve DF60 MK37) Formulation Ethanol only Stage of Use BoU (act. 1-10) Product FP50 FP50 FP50 FP50 FP50 FP50 Actuator 0.50 mm 0.50 mm Mean 0.33 mm 0.33 mm Mean 0.22 mm 0.22 mm Mean Device 4.2 4.2 4.2 5.3 4.2 4.8 5.2 3.3 4.3 Throat 32.4 32.3 32.4 25.1 25.9 25.5 13.9 16.4 15.2 Stage 0 1.4 1.4 1.4 1.0 1.7 1.4 2.3 2.1 2.2 Stage 1 0.1 0.1 0.1 0.1 0.1 0.1 0.3 0.3 0.3 Stage 2 0.0 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 Stage 3 0.1 0.1 0.1 0.1 0.3 0.2 0.2 0.2 0.2 Stage 4 0.3 0.3 0.3 0.3 0.5 0.4 0.7 0.5 0.6 Stage S 1.8 2.0 1.9 3.6 3.9 3.8 6.4 6.5 6.5 Stage 6 1.5 1.6 1.6 3.5 3.5 3.5 6.8 6.8 6.8 Stage 7 0.9 1.0 1.0 2.1 2.0 2.1 3.4 3.4 3.4 Filter 1.3 1.4 1.4 2.1 2.6 2.4 2.7 2.7 2.7 Total 44.0 44.5 44.3 43.3 44.8 44.1 42.1 42.4 42.3 Total ex-device 39.0 39.0 39.0 37.0 40.0 38.5 36.0 38.0 37.0 FPM, St3 + St4 + St5 2.0 2.0 2.0 4.0 4.0 4.0 7.0 7.0 7.0 FPM, St5 + St6 + St7 4.2 4.6 4.4 9.2 9.4 9.3 16.6 16.7 16.7 Ethanol and glycerol FP/134a 50 μg BoU (act. 1-10) Initial, BoU FP50 FP50 FP50 FP50 Mean 0.33 mm 0.33 mm Mean 0.22 mm 0.22 mm Mean 0.50 mm Device 4.7 4.4 4.6 4.4 3.7 4.1 6.6 Throat 26.2 28.5 27.4 16.3 17.8 17.1 13.5 Stage 0 1.0 1.3 1.2 3.6 2.6 3.1 1.6 Stage 1 0.2 0.4 0.3 0.6 0.4 0.5 0.8 Stage 2 0.3 0.4 0.4 1.0 0.7 0.9 1.1 Stage 3 1.4 1.5 1.5 4.3 3.5 3.9 3.2 Stage 4 2.6 2.5 2.6 6.2 5.5 5.9 9.8 Stage 5 4.0 3.5 3.8 7.5 7.0 7.3 11.2 Stage 6 1.0 0.9 1.0 1.8 1.4 1.6 1.4 Stage 7 0.6 0.5 0.6 1.0 0.9 1.0 0.3 Filter 0.5 0.4 0.5 0.7 0.6 0.7 0.2 Total 42.5 44.3 43.4 47.4 44.1 45.8 44.9 Total ex-device 38.0 39.0 38.5 44.0 43.0 43.5 43.3 FPM, St3 + St4 + St5 8.0 8.0 8.0 18.0 17.0 17.5 17.3 FPM, St5 + St6 + St7 5.6 4.9 5.3 10.3 9.3 9.8 9.6 All means, Totals and FPMs were calculated by Excel on rounded individual data *Flixotide Evohaler suspension formulation TABLE 6 Cascade Impaction analysis of FP/HFA134a 50 μg solution aerosols containing various solubilising agents (100 μl Valois valve, Bespak 0.22mm x 0.65mm actuator) Formulation FP 50ug FP 50pg FP 50 μg Stage of Use BoU (act. 1-10) BOU (act. 1-10) BoU (act. 1-10) Valve 100 μl 100 μl 100 μl 100 μl 100 μl 100 μl LVC — 1% glycerol — 1% glycerol — 1% glycerol Solvent 15% methylal* 15% methylal 15% ethyl acetate 15% ethyl acetate 10% ethanol 10% ethanol Device 5.9 6.2 9.0 6.4 4.3 4.4 Throat 5.8 6.3 5.3 13.8 15.2 14.0 Stage 0 1.4 3.9 1.2 1.6 2.2 3.3 Stage 1 0.5 0.8 0.5 0.6 0.3 0.7 Stage 2 0.6 0.7 0.5 0.8 0.2 1.0 Stage 3 0.9 1.4 1.1 1.7 0.2 5.3 Stage 4 1.6 2.3 0.8 1.8 0.6 8.1 Stage 5 6.9 10.3 1.9 9.2 6.5 8.8 Stage 6 8.8 7.6 5.0 6.2 6.8 2.4 Stage 7 6.0 3.8 4.4 3.2 3.4 1.3 Filter 4.8 2.0 3.0 2.0 2.7 0.7 Total 43.2 45.1 32.4 47.1 42.3 49.8 Total ex-device 37.3 39.0 23.4 40.7 37.0 45.5 FPM, St3 + St4 + St5 9.4 13.9 3.7 12.7 7.0 22.2 *Result based on one can only (can 2 data rejected as an atypical result) LVC = low volatility component TABLE 7 Cascade Impaction analysis of FP/HFA134a 50 μg solution aerosols containing various low volatility components (63 μl m/c Valois valve DF60 or 100 μl Valois valve, Bespak 0.22 mm × 0.65 mm actuator) Formulation FP50 μg HFA134a Stage of Use BoU (act. 1-10) FP50 μg HFA134a FP50 μg HFAI34a FP50 μg HFAI34a Valve Normalised BoU (act. 1-10) BoU (act. 1-10) BoU (act. 1-10) 63 μl for 100 μl Normalised Normalised Normalised LVC 1% propylene 1% propylene 63 μl for 100 μl 63 μl for 100 μl 63 μl for 100 μl glycol glycol 1% PEG200 1% PEG200 1% PEG400 1% PEG400 1% glycerol 1% glycerol Solvent 10% ethanol 10% ethanol 10% ethanol 10% ethanol 10% ethanol 10% ethanol 10% ethanol 10% ethanol Device 2.2 3.5 2.3 3.7 2.0 3.1 1.7 2.7 Throat 7.3 11.6 6.1 9.7 5.5 8.7 5.5 8.7 Stage 0 0.7 1.1 0.8 1.3 0.9 1.4 1.2 1.9 Stage 1 0.3 0.5 0.3 0.5 0.2 0.4 0.3 0.5 Stage 2 0.6 1.0 0.6 1.0 0.6 1.0 0.7 1.1 Stage 3 3.1 4.9 3.5 5.6 2.9 4.6 3.0 4.8 Stage 4 3.6 5.7 4.7 7.5 5.2 8.3 5.5 8.7 Stage 5 3.7 5.9 5.7 9.0 6.4 10.2 5.2 8.3 Stage 6 1.0 1.6 1.7 2.7 1.7 2.7 1.5 2.4 Stage 7 1.4 2.2 0.9 1.4 1.0 1.5 0.7 1.1 Filter 0.6 1.0 0.1 0.2 0.6 0.9 0.4 0.8 Total 24.3 38.6 26.5 42.1 27.0 42.8 25.4 40.3 Total ex-device 22.1 35.1 24.2 38.4 25.0 39.7 23.8 37.8 FPM, St3 + St4 + St5 10.3 16.3 13.8 21.9 14.5 23.0 13.6 21.6 LVC = low volatility component TABLE 8 Cascade Impaction analysis of FP 50 μg solution aerosols containing various propellants (64 μl m/c Valois valve DF60 or 100 μl Valois valve, Bespak 0.22 mm × 0.65 mm actuator) Formulation FP50 μg HFA227ea FP50 μg HFA227ea FP50 μg HFA134a Stage of Use BoU (act. 1-10) BoU (act. 1-10) BoU (act. 1-10) Valve Normalised Normalised Normalised 63 μl for 100 μl 63 μl for 100 μl 63 μl for 100 μl LVC — — 1% glycerol 1% glycerol 1% glycerol 1% glycerol Solvent 18% ethanol 18% ethanol 18% ethanol 18% ethanol 10% ethanol 10% ethanol Device 2.4 3.8 2.4 3.8 1.7 2.7 Throat 14.4 22.9 13.8 21.8 5.5 8.7 Stage 0 2.0 3.2 2.3 3.7 1.2 1.9 Stage 1 0.3 0.5 0.4 0.6 0.3 0.5 Stage 2 0.2 0.3 0.7 1.1 0.7 1.1 Stage 3 0.2 0.3 2.4 3.7 3.0 4.8 Stage 4 0.4 0.6 2.9 4.6 5.5 8.7 Stage 5 3.0 4.8 2.4 3.8 5.2 8.3 Stage 6 2.7 4.3 0.6 1.0 1.5 2.4 Stage 7 1.4 2.2 0.3 0.5 0.7 1.1 Filter 1.2 1.9 0.1 0.2 0.4 0.6 Total 28.1 44.6 28.2 44.8 25.4 40.3 Total ex-device 25.7 40.8 25.8 41.0 23.8 37.8 FPM, St3 + St4 + St5 3.6 5.7 7.7 12.1 13.6 21.6 LVC = low volatility component TABLE 9 Cascade Impaction analysis of FP 25 μg solution aerosols containing various propellants (63 μl m/c Valois valve DF60 or 100 μl Valois valve, Bespak 0.22 mm × 0.65 mm actuator) Formulation FP25 μg HFA134a FP25 μg HFA134a FP25 μg HFA134a FP25 μg HFA134a Stage of Use BoU (act. 1-10) BoU (act. 1-10) BoU (act. 1-10) BoU (act. 1-10) Valve Normalised Normalised Normalised Normalised 63 μl for 100 μl 63 μl for 100 μl 63 μl for 100 μl 63 μl for 100 μl LVC — — 1% glycerol 1% glycerol — — 1% glycerol 1% glycerol Solvent 7% ethanol 7% ethanol 7% ethanol 7% ethanol 14% ethanol 14% ethanol 14% ethanol 14% ethanol Device 1.3 2.1 1.1 1.7 1.1 1.7 1.0 1.6 Throat 1.3 2.1 1.6 2.5 4.2 6.7 4.5 7.1 Stage 0 0.1 0.2 0.3 0.5 1.1 1.7 1.5 2.4 Stage 1 0.0 0.0 0.1 0.2 0.1 0.2 0.3 0.5 Stage 2 0.0 0.0 0.2 0.3 0.1 0.2 0.4 0.6 Stage 3 0.0 0.0 1.1 1.7 0.1 0.2 1.6 2.5 Stage 4 0.1 0.2 2.7 4.3 0.1 0.2 1.9 3.0 Stage 5 1.0 1.6 4.1 6.5 1.9 3.0 1.5 2.4 Stage 6 2.8 4.4 1.3 2.1 2.4 3.8 0.4 0.6 Stage 7 2.4 3.8 0.6 1.0 1.4 2.2 0.2 0.3 Filter 1.9 3.0 0.3 0.5 1.0 1.6 0.2 0.3 Total 10.8 17.1 13.3 21.1 13.3 21.1 13.3 21.1 Total ex-device 9.5 15.1 12.2 19.4 2.3 19.5 12.3 19.5 FPM. St3 + St4 + 1.1 1.7 7.8 12.4 2.1 3.3 4.9 7.8 St5 LVC = low volatility component

There is provided according to the invention a pharmaceutical aerosol formulation which comprises: (i) fluticasone propionate and (ii) a hydrofluoroalkane (HFA) propellant, characterised in that the fluticasone propionate is completely dissolved in the formulation. The invention also provided canisters containing the formulation and uses thereof.

BACKGROUND OF THE INVENTION [0001] 1. Field of Invention [0002] The invention relates to a self-contained bubble generating apparatus, and more specifically to battery powered aquatic toys using pumps to aerate a fluid to generate bubbles for use in water such as in a bathtub. [0003] 2. Prior Art [0004] Toys, which resemble aquatic animals or aquatic vehicles and provide an electronically powered function, are well known. Such toys in the prior art tend to have their functionality limited to simple movement, spitting water, or making entertaining displays of lights and sounds. The toys in the prior art which include functionality for movement through the water do induce some surface effects on the water, but said effects are merely coincidental to the nature of disturbing water. [0005] It is therefore an object of the present invention to provide a self-contained aquatic toy with an electrically powered gas expulsion that aerates the surface of a fluid with micro pockets of gas, for the purpose of dense bubble generation. [0006] It is further an object to provide a gas expulsion system that provides a gentle motive for propulsion as if the accumulation of bubbles is pushing away the body of the present invention. [0007] These objects are attained according to the present invention in a self-contained aquatic toy with an enclosed pump that aerates near the surface of a fluid to generate bubbles on a surface bearing a surfactant while simultaneously providing propelled motion, wherein said device maintains the shape of an aquatic animal or object for the purposes of entertainment. SUMMARY OF THE INVENTION [0008] The present invention is a floating apparatus for aerating a fluid having a body with a buoyant shell, water sealing removable underside battery tray with water sensing contacts, waterproof inner compartment containing: electronic power and control logic board, gas & liquid pumping system, wherein the pumping system comprises of inlet ports, exhaust ports, inlet tubing, and exhaust tubing. One example of a buoyant shell is a duck. An example of an electrical control logic scheme is an on-off cycle for the pump triggered by the status of the water sensing contacts. BRIEF DESCRIPTION OF THE DRAWINGS [0009] FIG. 1 is a see-through view of complete assembly of invention. [0010] FIG. 2 is an isometric partially exploded view. [0011] FIG. 3 is an isometric view that is further exploded to show all components. [0012] FIG. 4 is an isometric view of the sub-assembly with components housed in 20 . [0013] FIG. 5 is an underside view of isolated housing 10 . [0014] FIG. 6 is a top, rear near-isometric view, showing the isolated housing 10 . [0015] FIG. 7 is a specific alternative embodiment of 10 . [0016] FIG. 8 is a specific alternative embodiment of 10 . [0017] FIG. 9 . is a cross section view of the completely assembled invention taken at exact center of body. DETAILED DESCRIPTION [0018] Turning now to the drawings in which like reference characters indicated corresponding elements throughout the several views. The main structure of this embodiment of invention, as shown in FIG. 2 , is comprised of the modules: 10 , the top of the aesthetic design shell; 20 , the carrier component housing the crucial electronic components; 30 , the aesthetic design shell bottom with pump discharge outlet; 40 , the on/off button. [0019] Looking at FIG. 2 the outer shell 10 and bottom shell 30 work, when water tightly fused, to form the aesthetic characteristics of a desired shape. Outer shell 10 , can be of a typical construction prevalent in many toy designs being generally made of a soft child safe plastic, one method of manufacture is rotational molding. In this case, the design of bottom shell 30 is such that in assembly the carrier component 20 and it's housed subcomponents, shown in FIG. 3 , 50 , 60 , 70 , 75 , 80 , 90 , and 95 are immovably affixed to the bottom shell 30 before the entire sub assembly consisting of 20 , 30 , 50 , 60 , 70 , 75 , 80 , 90 , and 95 , is immovably affixed to the outer shell 10 forming the final assembled form 100 as shown in FIG. 1 ; The arrows 1 through 4 , shown in FIGS. 2 and 4 , depict this assembly to be taken in the order of the arrow integer designations. This final assembled embodiment of invention leaves a water and air tight final assembly 100 with one point of ingress, 11 in FIG. 6 , and one point of egress, 31 in FIG. 9 . [0020] Operation of the invention is best illustrated by FIG. 9 . Activation of power could be made via an on/off switch 40 actuated via pinching pressure applied to a convenient surface on the outer shell 10 , such as the beak of a duck 12 . Actuation of switch 40 turns on power to the fluid/gas pump 75 , generally of a water and gas capable style, that sucks air from inlet 11 through inner inlet piping 90 to the sealed pump 75 and then accelerates out this air first through inner exhaust piping 95 and then out through nozzle 31 to form bubbles behind the floating aesthetic outer shell 10 in a liquid that has agents capable of forming bubbles. The arrow 8 shows the flow of air into inlet 11 and the arrow 9 shows the flow of exhaust gases out the exhaust nozzle into the area of bubble formation. The flexible exhaust tube 95 is substantially secured and sealed to the exhaust nozzle 34 and 75 in a manner appropriate of a device where water tightness is critical. The flexible inlet tubing 90 is substantially secured and sealed to the inlet nozzle 11 and 75 in a manner appropriate of a device where water tightness is critical. [0021] Looking now at FIG. 5 we see an isolated view of the outer shell 10 ; it is comprised of a thin walled material manufactured in a variety of methods suiting thin walled construction, rotational molding as an example. The design of the outer shell is subject to artistic freedom of a designer but with some restrictions on the feasibility of a shape from an engineering standpoint, mainly that it must be stable and float in a body of water. There generally exists two holes in the outer shell 10 ; the first being on the top portion 11 , best shown in FIG. 6 to allow an inlet of generally low in water mixture of air for said pump 75 ; the second hole 13 on the bottom portion of the thin walled shell is large enough to allow the entrance of the component carrier 20 and is sealed closed by the bottom shell 30 in assembly. Design alterations to this generally flat bottom structure of the outer shell 10 when combined with the bottom portion of the shell 30 may be made to increase the total volume of water displaced to increase the buoyant force applied to the invention to give more desirable floating and stability effects. A possible design alteration is shown in FIG. 7 : a boat like bottom hull 120 . The general purpose of these alterations of the invention are to increase the buoyant force on the body by increasing the amount of water displaced with added effect of increased water surface tension area and a lowering of the center of gravity and center of pressure on device into a more stable sub water line position. Likewise a design alteration 130 of outer shell 10 is seen in FIG. 8 showing modification that increases the surface area resting on the top of water for an increase in both buoyant force and surface tension. [0022] Directing attention to FIG. 3 we will now break down the factors of design on the bottom portion of the outer shell 30 . The bottom portion of outer shell 30 is a generally thin component matching in thickness and material as the outer shell 10 . Any standard plastic manufacturing process is suited for this component; Plastic Injection molding as an example. The generally flat shape of 30 can be adjusted in altered designs when needed for engineering requirements discussed earlier and the alterations to meet this design can be seen in FIGS. 7 and 8 . An alternate embodiment of the invention comprises a change in the setup of said battery 70 , by making component 34 removably affixed to 10 by a sealed gasket with the addition of a battery tray, thus making a removable battery alternative. The components attached to the outer shell bottom 30 rely on its shape for their general base design and layout and shall be adjusted around the general shape of outer shell bottom 30 . These components of whom are children, in design to 30 , are generally: the component carrier 20 along with all intricacies, the recharger contact plate 50 , and the layout of components 60 , 70 , 75 , 80 , 90 , and 95 . The component 30 contains a number of raised standard bosses 32 that are used to immovably affix the component carrier 20 to the bottom outer shell 30 . Attention turning to FIG. 9 , a depression 33 from the shape of outer shell bottom 30 of same general wall thickness is typically included to allow a nozzle like form for exhaust gas/fluids to exit away from the body. This depression generally has an inward facing raised boss 34 that connects in a standard male to female type to the outlet tubing 95 coming from the pump 75 . The end, or water facing surface of the depression 33 is capped with an outlet nozzle 31 with a number of arranged holes whose size, shape and quantity are allowed to vary to separate the exhaust flow into a certain number of varying size and flow rate bubble streams; the exact design of 31 is generally dependent on the components used in manufacture of this invention and the desired end result in produced bubble density. As shown in FIG. 3 , Holes 34 are slotted into 30 to allow for the recharger contact points 51 to pass through the thin walls of the material and make contact with an external recharger. The recharger contact plate 50 consists of two metal contacts 51 in the shape of an external re-charger's terminal points with a thin intermediary body whose shape matches the contours of the bottom outer shell 30 . The recharger contact plate is immovably and substantially affixed to the inner portion of 30 with methods of adhesion appropriate in creating a waterproof seal. An alternative embodiment for sending a power signal to said pump 75 comprises a modification of said contacts 51 to be water sensing power cycle triggers. [0023] Turning attention primarily to FIG. 4 , immovably fixed in assembly to the bottom Shell is the carrier component sub assembly 20 . This component is guided in assembly, arrow 2 , to the intended location and affixed via extrude pins 23 on the bottom shell and hollow extrusions 24 on the carrier component 20 located at corner points that insure non movement of the parts when fully assembled. The hollow extrusions 27 are shown in this depiction of invention as having ribs 28 added to better support stresses on the structure and crucially prevent warping from uneven cooling during a plastic injection process, a possible method of manufacture for said carrier component 20 . The inside surface of the hollowed extrusion 27 is substantially fixed to the extrusion 32 by means of either friction, a hook and latch system, chemical welding, molecular welding, plastic welding, or other appropriate forms of adhesion. The carrier component 20 is a thin walled plastic device that houses the crucial components of: Vacuum or mixed fluid and gas pump 75 , battery 70 , battery 70 terminal connector 80 , re-charger connector plate 50 , PCB board 60 that contains all the necessary electronic components for operation of the invention, inlet pipe 90 , and the outlet pipe 95 . Electronic connectors to all components are not represented in the three dimensional Figs. Carrier component 20 is split into two halves 21 and 22 for assembly purposes and to allow the component to be manufactured using methods that require drafting and/or split lining. The components within the carrier sub assembly are held in place by various ribs 29 added to the thin shelled walls of 21 and 22 in positions that substantially hold the previously mentioned components within the carrier assembly 20 . The halves 21 and 22 of 20 are substantially affixed together with the interface of the cylindrical extrusions 23 and the hollow extrusions 24 , whose inner diameter is matched to the outer diameter of feature 23 . [0024] The components housed within the carrier component, during the assembly process are generally placed into one side either 21 or 22 of the carrier component 20 and held in the various and appropriately positioned ribs 29 by gravity as long as the half being used for this assembly process is turned up at an appropriate angle, arrow 1 shows this process. The other half can then be attached, immovably securing the components in their holding enclosures created by the ribs 29 , arrow 2 shows this process. This assembly is then immovably affixed to the bottom outer shell 30 , as shown by arrow 3 in FIG. 2 , before being brought into the insides of 10 along arrow 4 where the hole 13 , shown in FIG. 5 , and the outer edge of 30 , shown in FIG. 3 , are sealed by a reliable welding or adhesion method including: chemical welding, ultrasonic welding, plastic/simple thermal welding, or by effective means of adhesion. [0025] The above described total embodiment of invention has numerous uses not to be limited to but included: an aquatic toy that floats on a surface and generates bubbles around it. It is to be understood that the foregoing description and specific embodiments are merely illustrative of a specific mode of the invention and the principles thereof, and that various modifications and additions may be made to the apparatus by those skilled in the art, without departing from the spirit and scope of this invention, which is, therefore, understood to be limited only by the scope of the appended claims.

A floating apparatus for aerating a fluid having a duck shaped body with a buoyant shell, water sealing removable underside battery tray with water sensing contacts, waterproof inner compartment containing: electronic power and control logic board, gas & liquid pumping system, wherein the pumping system comprises of inlet ports, exhaust ports, inlet tubing, and exhaust tubing. An electrical control logic scheme is an on-off of a pump which is triggered by the status of water sensing contacts.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This Patent Application claims priority to U.S. Patent Application Ser. No. 62/310,435 titled Wearable Impact Protection and Force Channeling Device filed Mar. 18, 2016, the entire contents of which is herein incorporated by reference in its entirety. BACKGROUND [0002] 1. Field [0003] The present inventive concept relates to a wearable safety device configured to protect a user from brain and neck trauma by preventing direct impact to the user's head. More particularly, the present inventive concept provides a wearable impact protection and force channeling device operable to transfer force received via impact from a head of the user to a body of the user, thereby utilizing an entire mass of the user to lessen rapid momentum change of the head. [0004] 2. Description of Related Art [0005] The brain has natural shock absorbers in the form of three layers of meninges membranes and cerebrospinal fluid, but these can be overwhelmed when subjected to excessive force. Brain-skull contact is most likely under two conditions, i.e., first at an initial impact, e.g., from being struck, when the skull rapidly gains momentum and is driven into the brain due to its inertia lag, or second when the skull comes suddenly to rest, e.g., from striking the ground, but the momentum of the brain causes it to continue its movement and strike the skull. Thus, to limit the momentum/inertia imbalance that causes brain-skull contact, an acceleration/deceleration inhibitor for the head must be integrated into any head protection device. [0006] Conventional helmets are worn to reduce impact induced head injuries in various industries such as sports, e.g., football, lacrosse, BMX, NASCAR, rally racing and construction. Conventional helmets are operable to be secured to a user's head in an attempt to reduce direct impact damage. [0007] A problem with such conventional helmets is that, among other things, such allow impact forces to be concentrated on the head of the user, thereby creating sudden acceleration and/or deceleration of the head of the user. Such sudden acceleration and/or deceleration can result in a concussion, which occurs when the user's brain impacts an interior of the user's skull. Further, such sudden acceleration and/or deceleration can result in impact induced movement of the head independent of the body, which creates stress concentrations along the neck and spinal cord. Such stress concentrations can result in paralysis. [0008] When conventional helmets are used in sports, such allow the kinetic force of an impacting opposing player, which consisting of one half of their entire mass times their velocity squared, to be concentrated initially at the moment of impact onto the much lesser head mass of the impactee helmet user. The overall ratio of the total mass of the opposing player vs. the helmet user's head mass usually exceeds 10 : 1 in normally proportioned individuals and may exceed 20:1 in professional athletes who are larger and more muscular. Thus, by the limitation of their design, conventional helmets are required to initially resist an order of magnitude imbalance between the impacting force and the resisting force caused by the disproportion of the total mass of the impacting player and the limited mass of the head of the impactee. This force imbalance results in excessive acceleration of the helmet user's head imparted by the momentum of the opposing player, which can result in concussion if the sudden acceleration or deceleration causes their brain to strike the inside of the skull. Additionally, even though conventional helmets may prevent direct damage to the user's skull, they do nothing to resist force concentration to the neck of the impactee, which may also result in paralyzing injury. [0009] Accordingly, there is a need for a device that does not suffer from the limitations of conventional helmets, is operable to protect a user's neck as well as a user's head, is operable to channel forces received from both acceleration and deceleration away from a user's neck and head, has a simple design that is easy to use, and is economical to manufacture. SUMMARY [0010] The following brief description is provided to indicate the nature of the subject matter disclosed herein. While certain aspects of the present inventive concept are described below, the summary is not intended to limit the scope of the present inventive concept. Embodiments of the present inventive concept provide an inventive concept for a wearable impact protection and force channeling device operable to transfer force received via impact from a head of a user to a body of the user, thereby utilizing an entire mass of the user to lessen rapid momentum change of the head. The present inventive concept does not suffer from and remedies the deficiencies of conventional devices such as those previously set forth herein. [0011] Instead of a helmet being fastened to the head of the user as a protective shell while still allowing direct impact to the helmet/head and subsequent force concentrations to the neck, the present inventive concept provides a device that encases both the head and neck via a protective dome that is fastened to the body of the user, thereby preventing direct contact with the head and neck, and channeling or transferring the force of the impact to the body of the user. In this manner, the device of the present inventive concept allows the entire mass of the user to resist the impact force, thereby reducing acceleration, as opposed to conventional helmets that allow an impact to be concentrated on just the user's head mass. [0012] It is an object of the present inventive concept to channel or transfer impact force to the body of the user instead of the direct contact with the head that conventional helmet technology allows. [0013] It is an object of the present inventive concept to protect the neck, thereby reducing the chance of spinal injuries. [0014] It is an object of the present inventive concept to provide a protective device that can be used in various applications including, but not limited to sports protective gear, e.g., football in secondary school, college and NFL, and hockey, lacrosse, BMX, NASCAR and/or the like. [0015] The device of the present inventive concept generally includes three components, i.e., a protective transparent dome that encapsulates a head of a user, a body harness that fastens to the body of the user and is operable to securely support the dome, and an inflatable restraint system to limit head and neck movement, which serves a dual purpose of dampening head acceleration and preventing impact of the user's head with the inside of the dome and collar. When the first component is affixed to the second component, the combination prevents direct impact contact with the neck and head, and transfers impact forces to the body of the user. [0016] Depending upon application of the device of the present inventive concept, the dome may be made of either a completely transparent material or a combination of one or more transparent and opaque materials. [0017] The dome is semi-spherical in shape, the surface of which is treated with an anti-fogging coating supplemented with anti-fogging ventilation slits near the crown, and either a threaded slatted flange or a slatted horizontal flange at its base for insertion into the mounting collar of the body harness. If the optical characteristics of the dome material adversely affect the performance of the user, the dome may be optionally equipped with an open viewport. [0018] The body harness consists of a shell with front and back plates that has its inside surface lined with compression pads to facilitate a tight fit when secured, that is strapped tight to the body of the user and to which existing football shoulder pad technology can be affixed, a mounting collar with a slotted receiver ring that allows the insertion and rotation of the corresponding slatted flange of the dome, a front opening in the mounting collar for access to the user's mouth, a locking mechanism consisting of a spring tensioned pin that secures the dome once it is inserted into the receiver ring, a loop on the spring tensioned locking pin to enable the attachment of a mouth guard and to facilitate the manual depression of the pin, a restraint system consisting of an inflatable bladder encased within multi-densities of compression foam to limit head movement (to resist head impact with the dome and prevent neck injury), and a recessed valve to allow for the inflation of the restraint system. A compression ring option may be installed in the collar to allow yielding of the dome-collar assembly upon impact, so as to lessen the chance of injury to opposing players when they are struck by the assembly. [0019] The aforementioned may be achieved in one aspect of the present disclosure by providing a protective device operable to transfer force from a first portion of a user to a second portion of a user. The device may include a first component operable to encapsulate a first portion of a user. The first component may be entirely, mostly, or partially transparent to permit the user to view through the first component, thereby providing a user with visibility through the device. The device may also include a second component operable to secure the first component to a second portion of the user. The device may also include a third component secured to the second component. The third component may be operable to limit movement of the user relative to the second component. [0020] The first component may be entirely or partially curved or dome-shaped. The second component may include a harness and is able to function as a body harness. The third component may be entirely or partially inflatable, e.g., via introduction of air into the third component via a valve or the like. [0021] The device may further include a circulation system operable to (i) permit gas to enter and/or exit the first component, and/or (ii) maintain a degree of visibility through the portion of the first component. The circulation system may include at least one vent in and/or extending entirely through the first component. [0022] The device may further include at least one interior compression pad having an inflatable bladder on the second component and/or the third component. The device may further include an access port on the second component operable to allow a user access to the third component to inflate the third component. The device may further include at least one inflation valve accessible via the access port on the second component. The at least one inflation valve may be in communication with the inflatable bladder. The inflation valve may be recessed relative to an outermost surface of the second component. [0023] The device may further include at least one front opening in the second component. The device may further include at least one mounting collar on the second component. The at least one mounting collar may be resiliently secured to the second component so that the at least one mounting collar is biased away from the second component, e.g., via one or more resilient elements or springs. [0024] The device may further include at least one locking mechanism operable to secure the first component to the second component. The device may further include at least one release mechanism operable to enable detachment of the first component from the second component when actuated. The device may further include a mounting loop operable to secure a mouth guard to the device. [0025] The device may further include at least one fastener on the second component. The device may further include at least one shoulder pad and/or chest plate on the second component. The first component may be operable to be secured to the second component by insertion of the first component into the second component. The first portion of the user may be a head of the user. The second portion of the user may be a body of the user. [0026] The foregoing and other objects are intended to be illustrative of the present inventive concept and are not meant in a limiting sense. Many possible embodiments of the present inventive concept may be made and will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof. Various features and subcombinations of the present inventive concept may be employed without reference to other features and subcombinations. Other objects and advantages of this present inventive concept will become apparent from the following description taken in connection with the accompanying drawings, which set forth by way of illustration and example, an embodiment of this present inventive concept and various features thereof. BRIEF DESCRIPTION OF DRAWINGS [0027] A preferred embodiment of the present inventive concept, illustrative of the best mode in which the applicant has contemplated applying the principles, is set forth in the following description and is shown in the drawings. [0028] FIG. 1 is a top, left, front perspective view of a wearable impact protection and force channeling device of the present inventive concept; [0029] FIG. 2 is an elevated front view of the device of FIG. 1 fitted on a user; [0030] FIG. 3 is a magnified cross-sectional elevated side view of a locking mechanism of the device of FIG. 2 ; [0031] FIG. 4 is a cross-sectional elevated side view of the device of FIG. 2 fitted on the user; [0032] FIG. 5A is an exploded side view of the device of FIG. 1 with a first component removed from a second component and the second component in cross section; [0033] FIG. 5B is a magnified side view of a compression ring of the device of FIG. 5A ; [0034] FIG. 6A is an exploded side view of another embodiment of the device of FIG. 1 with a first component removed from a second component and the second component in cross section; [0035] FIG. 6B is a magnified side view of a retainer ring of the device of FIG. 6A ; [0036] FIG. 6C is a magnified top plan side view of the retainer ring of the device of FIG. 6A ; [0037] FIG. 7A is an exploded side view of another embodiment of the device of FIG. 1 with a first component removed from a second component; and [0038] FIG. 7B is a magnified front view of the device of FIG. 7A with the first component secured to the second component and the first and second components in cross section. [0039] The drawings do not limit the present inventive concept to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed on clearly illustrating principles of certain embodiments of the present inventive concept. DETAILED DESCRIPTION [0040] The following detailed description references the accompanying drawings that illustrate various embodiments of the present inventive concept. The illustrations and description are intended to describe aspects and embodiments of the present inventive concept in sufficient detail to enable those skilled in the art to practice the present inventive concept. Other components can be utilized and changes can be made without departing from the scope of the present inventive concept. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the present inventive concept is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled. [0041] I. Terminology [0042] In the description, terminology is used to describe features of the present inventive concept. For example, references to terms “one embodiment,” “an embodiment,” “the embodiment,” or “embodiments” mean that the feature or features being referred to are included in at least one aspect of the present inventive concept. Separate references to terms “one embodiment,” “an embodiment,” “the embodiment,” or “embodiments” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated and/or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, process, step, action, or the like described in one embodiment may also be included in other embodiments, but is not necessarily included. Thus, the present inventive concept may include a variety of combinations and/or integrations of the embodiments described herein. Additionally, all aspects of the present disclosure as described herein are not essential for its practice. [0043] The term “user” is generally used synonymously herein to represent a user of the device. For purposes herein, the user may be an athlete or a construction worker. [0044] Lastly, the terms “or” and “and/or” as used herein are to be interpreted as inclusive or meaning any one or any combination. Therefore, “A, B or C” or “A, B and/or C” mean “any of the following: A; B; C; A and B; A and C; B and C; A, B and C.” An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive. [0045] As the present inventive concept is susceptible to embodiments of many different forms, it is intended that the present disclosure be considered as an example of the principles of the present inventive concept and not intended to limit the present inventive concept to the specific embodiments shown and described. [0046] II. General Architecture [0047] Turning to the drawings and particularly FIGS. 1-6C , a wearable impact protection and force channeling device 10 is illustrated. The device 10 includes a first component 12 operable to be detachably secured to a second component 14 . In the exemplary embodiment, the first component 12 is a protective semi-spherical, dome-shaped element operable to be received over and encompass a user's head. It is foreseen that the first component 12 can be variably sized to accommodate heads of different sizes and may not be perfectly semi-spherical, but may have an oblong shape or be shaped as an elliptical sphere without deviating from the scope of the present inventive concept. For instance, an average head is approximately 9 inches long, 6 inches wide, and 9 inches tall. In the exemplary embodiment, the first component 12 is sized and shaped to provide at least 3 inches of clearance between an average-sized head and an inner surface of the first component 12 , thus is approximately 15 inches long, 12 inches wide, and 8 inches tall, given a portion of the second portion encloses the head. [0048] The first component 12 includes a viewing area 16 made of a transparent material operable to allow the user to see through the first component 12 . The viewing area 16 is sized and shaped to allow the user of the device 10 to have a full viewing range so that the device 10 does not block any portion of a user's field of vision including peripheral vision. In the exemplary embodiment, the first component 12 is entirely made of the transparent material such as polycarbonate or other similar high-strength impact-resistant material. [0049] The device 10 of the present inventive concept includes one or more of the following features to prevent fogging caused by, for example, the user's breath, perspiration, and/or heat. It is foreseen that a portion of the first component 12 , i.e., a 16 , may be provided through the first component so that the user's head is encapsulated by the device 10 except for a portion aligned with a forward view of the user. Alternatively or in addition to the viewport 16 , a circulation system may be provided via a plurality of vent holes 17 in the first component 12 to prevent fogging of the first component 12 . Alternatively or in addition to the viewport 16 and/or vent holes 17 , an inner surface of the first component 12 may include an anti-fogging coating to prevent fogging of the first component 12 . [0050] The first and second components 12 , 14 are secured together via a flange 18 formed at a base of the first component 12 and a mounting collar 20 on the second component 14 . The collar 20 has an inverted conical shape with an opening at the top defined by a circumferential receiver 22 and an opening at the bottom, which is attached to a remainder portion of the second component 14 . The openings permit the user to extend his/her head through the collar 20 . The collar 20 is substantially made of hard impact resistant plastic, which may be opaque or color infused, with various fittings and other portions of the collar 20 made of steel. It is foreseen that the collar 20 may be made of another material such as, but not limited to, polycarbonate, carbon fiber material, or other high strength material without deviating from the scope of the present inventive concept. [0051] In the exemplary embodiment, the mounting collar 20 is operable to receive the flange 18 within the circumferential receiver 22 , which extends around an uppermost portion of the mounting collar 20 . The receiver 22 includes a circumferential groove 24 formed by a circumferential lip 26 with a plurality of slots 28 . The slots 28 are evenly spaced from each other about a substantial portion of the lip 26 and angled downwardly, e.g., between twenty and thirty degrees relative to a plane defined by the groove 24 , and preferably at twenty-five degrees. Each of the slots 28 is sized and shaped to receive one of a plurality of extensions 30 , which also extend from a circumferential surface of the flange 18 at a downward, e.g., between twenty and thirty degrees and preferably at twenty-five degrees, form a portion of the flange 18 . As with the slots 28 , the extensions 30 are also evenly spaced from each other about a substantial portion of the flange 18 so that each of the slots 28 are sized and shaped to be securely received in one of the slots 28 . [0052] The first component 12 may be secured to the second component 14 via a number of various engagements. In the exemplary embodiment, the first component 12 is secured to the second component 14 via (i) nesting the first component 12 into the second component 14 so that a tip of each of the extensions 30 extends into one of the slots 28 and (ii) rotating the first component 12 so each of the extensions 30 is wedged or threaded into and become seated within one of the slots 28 so that the extensions 30 are entirely housed within the slots 28 . When the first component 12 is rotated, the mating of the extensions 30 and slots 28 causes the first component 12 to be drawn closer to the second component 14 . In the exemplary embodiment, each of the extensions 30 are approximately 2 inches long, and the first component 12 is rotated approximately 18 degrees to cause the extensions 30 to become threaded into the slots 28 . It is foreseen that the extensions 30 may be shorter or longer, e.g., be 1.75 to 2.25 inches long, and/or be variably sized without deviating from the scope of the present inventive concept. To increase friction between the slots 28 and the extensions 30 , the extensions 30 are tapered and have a wedge-shape, with (i) a smaller width at a leading edge of each of the extensions 30 that is first introduced into one of the slots 28 , and (ii) a larger width at a trailing edge of each of the extensions 30 . In this manner, the extensions 30 engage the slots 28 , upon counter-clockwise rotation of the first component, via a friction fit engagement, thereby securing the first component 12 to the second component 14 . The first component 12 is removed from the second component via clockwise-rotation of the first component 12 relative to the second component 14 , which causes the components 12 , 14 to be pushed away from each other and the extensions 30 to be removed from the slots 28 . [0053] When the first component 12 is secured to the second component 14 , a locking mechanism 32 positioned at a front of the collar 20 is operable to prevent one of the extensions 30 from being removed from one of the slots 28 . The locking mechanism 32 includes a locking pin 33 that is biased upwardly and toward the first component 12 to a locked position via a spring 34 . The pin 33 includes a sloped surface 35 . The locking mechanism 32 includes a 90 degree pivot range, and is operable to be rotatably actuated, via a handle 36 , from a locked position at one end of the pivot range, i.e., with the handle 36 extending laterally relative to a user and the device 10 , and an unlocked position at another end of the pivot range, i.e., with the handle 36 extending away from the user and the device 10 . With the locking mechanism 32 in the unlocked position, the flange 18 is received into the groove 24 , which causes one of the extensions 30 to engage and force the pin 33 downwardly from its original position as illustrated by FIG. 3 , which causes the spring 34 to become compressed. Once compressed, the first component 12 is rotated as previously discussed so the extensions 30 engage the slots 28 . Once engaged, the trailing edge of the one of the extensions 30 clears the pin 33 , which allows the pin 33 to return to its original position due to resilient bias of the spring 34 . Finally, the handle 36 is rotated 90 degrees to extend laterally relative to the user, which causes the locking mechanism 32 to lock the flange 18 within the groove 24 . The handle 36 may be designed to extend at least partially through a mouth port 76 when in the unlocked position and be flush with or recessed within the mouth port 76 when in the locked position. [0054] While the device 10 of the present inventive concept is operable to protect the user against impact to the user's head and neck, the device 10 could present a danger of injury to others, e.g., opponents when used during a sporting event, if the user uses the device 10 to “spear” impact them. While steps should be taken to modify rules of the sporting event to penalize such action, it is beneficial to provide a means of yielding within the collar 20 to dissipate or absorb the force of such impacts. For this purpose, the collar 20 includes a compression ring 39 . The compression ring 39 includes a spring loaded channel and flange. The compression ring 39 is located around a perimeter of the base of the collar 20 and biases the collar 20 away from a remainder portion of the second component 14 . The compression ring 39 is operable to allow the collar 20 to compress approximately 1 inch toward the portion of the remainder portion of the second component 14 when a compression force is applied to a portion, e.g., a top, of the collar 20 . [0055] It is foreseen that the flange 18 could be formed on the second component 14 and the receiver 22 could be formed on the first component 12 without deviating from the scope of the present inventive concept. [0056] The second component 14 includes an outermost surface 40 that is at least partially contoured to a body of the user, e.g., a torso and shoulders. For example, a chest or front plate 41 of the second component 14 includes contoured portions 42 that are sized and shaped to correspond to a chest of the user, while a back plate 43 of the second component 14 is curved to correspond to a back of the user. The second component 14 includes a pair of openings 44 on either side of the second component 14 that are each operable to surround an uppermost portion of a shoulder of the user so that a portion of the shoulder and an arm of the user can extend from the second component 14 of the device 10 . In this manner, the second component 14 is operable to allow an unimpaired full range movement of the arms of the user. [0057] Each of the openings 44 include a body harness or fastener 46 secured at opposing ends 48 , 50 of the second component 14 . In the exemplary embodiment, the fastener 46 is a strap or belt and a buckle with the belt secured to the end 48 and the buckle secured to the end 50 , but it is foreseen that another type of securing mechanism may be used without deviating from the scope of the present inventive concept. The fasteners 46 are operable to allow ends 48 , 50 of the openings 44 to be selectively expanded away from each other and contracted toward each other by the user, e.g., when the user is taking the device 10 on or off, and to be secured together, e.g., during use of the device 10 . The fasteners 46 are operable to be secured at one of a plurality of points, thereby allowing the ends 48 , 50 to be secured at various distances with respect to each other. In this manner, the fasteners 46 allow the device 10 to accommodate various user body types. [0058] The second component 14 houses a third component 60 , i.e., an inflatable restraining system, positioned on one or more interior surfaces 62 of the collar 20 . The third component 60 includes at least one compression pad or inflatable component 64 that is operable to be inflated by introducing air into a bladder 66 of the inflatable component 64 via a recessed valve 68 located on a side of the collar 20 . The valve 68 is operable to be selectively opened and closed by the user, and is in communication with the bladder 66 to enable inflation and deflation of the bladder 66 . The valve 68 is accessible via an access port 70 that extends through the collar 20 of the second component 14 . [0059] In the exemplary embodiment, the third component 60 is sized and shaped to encompass a neck and a portion of the head of the user, i.e., donut shaped. The third component 60 is operable to receive air into the bladder 66 and expand to snugly fit around the neck and the portion of the head of the user. The third component 60 includes an indent 72 sized and shaped to receive a chin of the user, and an opening 74 at the front that is positioned to align with the mouth port 76 at a front of the collar 20 . The opening 74 and the mouth port 76 provide access to a mouth of the user. [0060] The second component 14 also includes a plurality of pads 80 operable to diffuse and distribute force received on the device 10 from an impact. Each of the plurality of pads 80 are secured to an interior surface 82 of the second component 14 so that the interior surface 82 is substantially lined by the pads 80 and the interior surface 82 is spaced from the user by the pads 80 . In the exemplary embodiment, the pads 80 are made of foam. It is foreseen, however, that the pads 80 may be made of rubber or the like without deviating from the scope of the present inventive concept. [0061] The handle 36 also can be used as a mouthpiece ring 90 given its location on a side of the collar 20 and accessibility via the mouth port 76 . The ring 90 is operable to provide a connecting point for a mouthpiece guard. [0062] In this manner, the second component 14 is operable to function as a body harness, stabilizes and secures the mounting collar 20 to the body of the user, and allows the transference of force from impact on the first component 12 to the body of the user. The second component 14 is sized and shaped to allow traditional football shoulder pads to be fastened to the second component 14 . In the exemplary embodiment, the second component 14 is made of high impact resistant plastic, which may be opaque or color infused. It is foreseen that the second component 14 may be made of another material such as, but not limited to polycarbonate, a carbon fiber material, or the like without deviating from the scope of the present inventive concept. [0063] To use the device 10 , the user disconnects the fasteners 46 and expands the openings 44 . Then, wearing a tight, form-fitting t-shirt or the like, or no clothing, the user extends his/her head through a central hole 86 formed in part by the plates 41 , 43 in the second component 14 , through the collar 20 , and into the first component 12 until the shoulders of the user abut shoulder portions 88 of the second component 14 . When worn, the collar 20 encompasses the neck and lower head portion of the user and the circumferential receiver 22 of the collar 20 transcribing an imaginary line from below the nose to roughly the rear base of the skull of the user. Then, the user contracts the openings 44 via the fastener 46 to one of the plurality of positions provided by the fastener until the pads 80 abut the chest and back of the user or the t-shirt of the user. Then, the valve 68 is opened and air is introduced into the bladder 66 of the inflatable component 64 until the inflatable component abuts the neck and head of the user, at which point the valve 68 is closed to lock or trap the air in the bladder 66 . In this manner, the third component 60 is tightly fitted around the neck and lower head portion of the user, and provides a shock absorber and prevents any contact between the head of the user and the collar 20 and the first component 12 . [0064] As mentioned, the first component 12 may be secured to the second component 14 via a number of various engagements. For instance, in an alternative embodiment, as illustrated by FIGS. 6A-6C , a first component 112 , with vent holes 117 , is secured to the second component 114 via only vertical nesting without rotating the first component 112 . In this embodiment, a flange 118 of the first component 112 includes a plurality of extensions 130 that extend horizontally from a bottom surface 132 of the first component 112 to the define an upwardly-facing abutment surface 134 and a downwardly-facing abutment surface 136 . In this embodiment, the extensions 130 are spaced approximately 2 inches apart, but it is foreseen that the extensions 130 could be otherwise spaced without deviating from the scope of the present inventive concept. For instance, it is foreseen that the extensions 130 may be shorter or longer, e.g., be 1.75 to 2.25 inches long, and/or be variably sized without deviating from the scope of the present inventive concept. [0065] To secure the first component 112 to the second component 114 , the first component 112 is vertically placed onto the second component 114 so that each of the extensions 130 extends into one of a plurality of openings 138 in a rotatable ring 140 with each of the downwardly-facing abutment surfaces 136 abutting a top of the collar 120 . The ring 140 is secured to the collar 120 via corresponding ridges 142 and grooves 144 on each of the collar 120 and the ring 140 . In this embodiment, the ring 140 forms a “T” shaped portion that extends into a corresponding “T” shaped portion of the collar 120 of the second component 114 . It is foreseen, however, that the ring 140 could have an “L” shaped portion operable to extend into a corresponding “L” shaped portion of the collar 120 of the second component 114 or other correspondingly-shaped portions without deviating from the scope of the present inventive concept. In this manner, the ring 140 is rotatably secured to the collar 120 of the second component 114 . The ring 140 includes tabs 146 spaced from each other by spacer bars 148 . After the first component 112 has been placed on the collar 120 , the ring 140 is rotated so that each of the tabs 146 extends over one of the extensions 130 to abut the upwardly-facing abutment surface 134 and at least partially conceal each of the extensions 130 . In this manner, the components 112 , 114 are secured together via a friction-fit engagement. [0066] Turning to FIGS. 7A and 7B , a first component 212 is secured to the second component 214 via only horizontal nesting without rotating the first component 212 , the second component 214 , or any portion thereof. The first component 212 is shaped as a quarter dome as opposed to the semi-spherical dome of the first component 12 . An uppermost portion of the second component 214 is also shaped as a quarter dome that, in combination with the first component 212 , collaboratively form a semi-spherical dome. In this embodiment, a vertical flange 218 and a horizontal flange 220 of the first component 212 is sized and shaped to be slidably received within vertical slot 230 and horizontal slot 234 , respectively. In this manner, the components 112 , 114 are secured together via a friction-fit engagement. [0067] In another embodiment, the first component 12 may include a male thread and the second component may include a female thread that is sized and shaped to correspond to the male thread. The components 12 , 14 may be secured together by (i) nesting the first component 12 into the second component 14 and (ii) rotating the first component 12 so the threads engage each other. In another embodiment, the first component 12 may have a portion that is sized and shaped to be slidably received into a groove a portion of include a male thread and the second component may include a female thread. The components 12 , 14 may be secured together by (i) nesting the first component 12 into the second component 14 and (ii) rotating the first component 12 so the threads engage each other. [0068] Accordingly, the device 10 of the present inventive concept provides impact protection to the user of the device 10 by channeling force received from an impact during an activity of the user such as, but not limited to participating in sports, e.g., football, lacrosse, BMX, NASCAR, and rally racing, or at a jobsite, e.g., construction, thereby decreasing the likelihood the user will be injured or killed by the impact. [0069] Having now described the features, discoveries and principles of the present inventive concept, the manner in which the present inventive concept is constructed and used, the characteristics of the construction, and advantageous, new and useful results obtained; the new and useful structures, devices, tools, elements, arrangements, parts and combinations, are set forth in the appended claims. [0070] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the present inventive concept herein described, and all statements of the scope of the present inventive concept which, as a matter of language, might be said to fall there between.

A wearable impact protection and force channeling device operable to transfer force received via impact from a head of the user to a body of the user, thereby utilizing an entire mass of the user to lessen rapid momentum change of the head.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a printing apparatus to detect multi-feeding of sheets transferred along a sheet transfer route. [0003] 2. Description of the Related Art [0004] A printing apparatus circulates a plurality of sheets separately by feeding one by one from a stack of sheets in a sheet feed rack of a feeding mechanism. Meanwhile, the plurality of sheets may be overlapped and transferred together when passing through a printing mechanism. This is so-called “multi-feeding of sheets”. Japanese Patent Laid-Open Publication No. 2001-063872 discloses a technology for detecting multi-feeding of sheets by means of a light transmission sensor as a multi-feed detection sensor provided on a sheet transfer route. The light transmission sensor measures the amount of light transmission of a sheet on the sheet transfer route so as to detect the multi-feeding of sheets since the amount of light transmission is dependent on a thickness of a sheet. [0005] FIG. 1A shows one example of conventional arrangements of light transmission sensors used for detecting multi-feeding of sheets. In this figure, a sheet from a sheet feeding side is transferred to register rollers 750 to pause for positioning a front edge part of the sheet. Then, the sheet is guided to print heads 712 by the register rollers 750 . [0006] In the sheet transfer route, a light transmission sensor 760 composed of a light emitter 762 and a light-receiving sensor 764 is provided on the sheet feeding side of the register rollers 750 . While, a light transmission sensor 770 composed of a light emitter 772 and a light-receiving sensor 774 is provided on a sheet exit side of the register rollers 750 . The light transmission sensor 760 serves as a register sensor to detect a sheet entering the register rollers 750 . The light transmission sensor 770 serves as an edge part detection sensor to detect edge parts of the sheet further transferred to the print heads 712 . [0007] The light transmission sensor 760 provided on the sheet feeding side of the register rollers 750 also serves as a multi-feed detection sensor in order to detect multi-feeding of sheets on the feeding side as quickly as possible. SUMMARY OF THE INVENTION [0008] The register rollers 750 are used for positioning a front edge part of sheets, and for adjusting oblique sheets. A sheet P enters the register rollers 750 with an excessive feed slightly toward the print head side by sheet feeding rollers not shown in the figure. Then, the sheet P pauses loosely at the register rollers 750 as shown in FIG. 1B in order for an adjustment of a sheet obliqueness. The light transmission sensor 760 as a multi-feed detection sensor is provided on the sheet feeding side of the register rollers 750 as mentioned above. Accordingly, the light transmission sensor 760 detects the amount of light transmission of the loose sheet. [0009] In such a case, the light transmission sensor 760 may detect the amount of light transmission variously per sheet since a loose state differs in each fed sheet. In addition, when there are several feeding mechanisms in a printing apparatus, there are also several feeding routes to transfer a sheet to the register rollers 750 per feeding mechanism. Thus, the light transmission sensor 760 may also detect the amount of light transmission variously per sheet (feeding route). As a result, the conventional multi-feed detecting method as shown in FIG. 1A may not be able to stabilize the accuracy of multi-feed detection. [0010] The present invention has been made to solve the above-mentioned issues. It is an object of the present invention to improve the accuracy of multi-feed detection. [0011] To achieve the above-mentioned object, according to an aspect of the present invention, a printing apparatus comprises: a printing mechanism forming an image on a sheet transferred in a sheet transfer route; a sheet feeding mechanism feeding sheets to the sheet transfer route; a register provided between the sheet feeding mechanism and the printing mechanism on the sheet transfer route so as to position a sheet fed from the sheet feeding mechanism and adjust an obliqueness of the sheet; an edge part detector provided on the sheet transfer route having a detecting section configured between the register and the printing mechanism so as to detect edge parts of a sheet transferred to the printing mechanism by the register, the edge part detector is configured to serve as a multi-feed detector to detect multi-feeding of sheets. [0012] According to the present invention, the edge part detector provided so as to detect edge parts of a sheet in a detecting section configured between the register and the printing mechanism is also used as a multi-feed detector. Therefore, it is possible to detect multi-feeding of sheets with more stable behavior in the detecting section compared with sheets transferred from the feeding mechanism to the register. Thus, the accuracy of multi-feed detection can be improved. BRIEF DESCRIPTION OF THE DRAWINGS [0013] FIGS. 1A and 1B are views showing one example of conventional arrangements of light transmission sensors used for detecting multi-feeding of sheets. [0014] FIG. 2 is a block diagram showing one example of configurations of a printing apparatus mainly including feeding mechanisms, a discharge mechanism and a printing mechanism. [0015] FIG. 3 is a view showing a positional relationship among register rollers, light transmission sensors and print heads. [0016] FIGS. 4A and 4B are views showing the received light amount of a sheet passing through light transmission sensors. [0017] FIG. 5 is a block diagram showing a configuration of an edge part and multi-feeding sheet detection system. [0018] FIG. 6 is a view showing detection blocks and sampling points for multi-feed detection. [0019] FIG. 7 is a flow chart showing multi-feed determination processing of first sheet feeding. [0020] FIG. 8 is a flow chart showing multi-feed determination processing after first sheet feeding. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0021] We now describe an embodiment of the present invention with reference to the drawings. FIG. 2 is a block diagram showing one example of configurations of a printing apparatus 10 mainly including feeding mechanisms, a discharge mechanism and a printing mechanism according to the present embodiment. As shown in the figure, the printing apparatus 10 has the sheet feeding mechanisms including a sheet feed rack 320 a , a first feed tray 320 b , a second feed tray 320 c and a third feed tray 320 d , and the sheet discharge mechanism including a face-down discharge tray 330 a In addition, the printing apparatus 10 may have optional discharge trays. The printing apparatus 10 may concurrently have some functions such as punching and stapling afterward, and may have a face-up discharge tray. [0022] The printing apparatus 10 has a sheet transfer route TR that includes a system of feeding routes FR for feeding a sheet, a discharging route DR for discharging the sheet, a normal transfer route PR for transferring the sheet received from the system of feeding routes FR to the discharging route DR, and an inverting route (switchback) SR branched from the normal transfer route PR, for inverting the sheet between front and back sides received from the normal transfer route PR to re-feed to the normal transfer route PR. The inverting route SR cooperates with the normal transfer route PR to constitute a looped sheet circulating transfer route CR. [0023] The printing apparatus 10 executes printing on a sheet fed from any feeding mechanism at print heads 312 , and discharges the sheet to the face-down discharge tray 330 a . The face-down discharge tray 330 a is provided at an upper part of a side surface of the printing apparatus 10 , to which the printed sheet is discharged with a printed side down. [0024] The printing apparatus 10 has the printing mechanism including a plurality of print heads 312 , each of which is provided with multiple nozzles formed perpendicular to a sheet transfer direction. Each of the print heads 312 propels droplets of black or color ink for printing in color bylines. The printing apparatus 10 has a controller 110 composed of a substrate with a mounted CPU, memories, etc., an operation panel 150 for interfacing user operations, and other components not illustrated in the figure. [0025] A sheet is fed one by one from any feeding mechanism and transferred along the system of feeding routes FR in a casing by an associated drive mechanism such as rollers, and guided to a register R. The register R is located near a junction of the system of feeding routes FR and the normal transfer route PR. The register R is composed of a pair of register rollers for positioning a front edge of the fed sheet. The fed sheet pauses at the register R for an adjustment of a sheet obliqueness. The fed sheet enters the register R with a slightly excessive feed and pauses loosely by means of sheet feeding rollers of the feeding mechanism from which the sheet is fed in order for the adjustment of the sheet obliqueness. The adjusted sheet is transferred to the normal transfer route PR provided with the printing mechanism at a controlled timing. [0026] In the sheet transfer route TR, a first light transmission sensor 160 is provided on a sheet feeding side of the register R, and a second light transmission sensor 170 is provided on a sheet exit side of the register R. The first light transmission sensor 160 serves as a register sensor to detect a sheet being fed to the register R. The second light transmission sensor 170 serves as a sheet edge part detection sensor, and also, as a multi-feed detection sensor. [0027] FIG. 3 is a view showing a positional relationship among register rollers 250 composing the register R, the first light transmission sensor 160 , the second light transmission sensor 170 and the print heads 312 . As shown in the figure, the first light transmission sensor 160 as a register sensor includes a light emitter 162 and a light-receiving sensor 164 . Also, the second light transmission sensor 170 as a sheet edge part and multi-feed detection sensor includes a light emitter 172 and a light-receiving sensor 174 . [0028] The second light transmission sensor 170 detects edge parts of a sheet P transferred to the print heads 312 , and detects multi-feeding of sheets. According to the present embodiment, the sheet edge part detection sensor, which is provided on the sheet exit side of the register rollers 250 , is also used as a multi-feed detection sensor. The sheet P pauses at the register R, and is transferred to the print heads 312 by the register rollers 250 . Therefore, the sheet P passing through the second light transmission sensor 170 is not influenced in the multi-feed detection by sheet looseness at the register R and a distinction of feeding routes. Thus, the second light transmission sensor 170 can examine each sheet evenly with less variability in the multi-feed detection. As a result, the accuracy of multi-feed detection can be enhanced. [0029] FIG. 4A is a view showing one example of the received light amount of the sheet P detected at the light-receiving sensor 174 of the second light transmission sensor 170 provided on the sheet exit side of the register rollers 250 . FIG. 4B is a view showing one example of the received light amount of the sheet P detected at the light-receiving sensor 164 of the second light transmission sensor 160 provided on the sheet feeding side of the register rollers 250 . [0030] As shown in the figures, the received light amount of the sheet P detected at the light-receiving sensor 174 of the second light transmission sensor 170 is kept at an approximately constant value throughout a part from a front edge to a back edge of the sheet. While, the received light amount of the sheet P detected at the light-receiving sensor 164 of the second light transmission sensor 160 varies precariously throughout the sheet. In particular, the received light amount of the sheet P varies in a stepwise manner when the front edge part of the sheet P passes through the sensor. Thus, the accuracy of multi-feed detection can be improved due to the light-receiving sensor 174 of the second light transmission sensor 170 provided on the sheet exit side of the register rollers 250 . [0031] As shown in FIG. 2 again, a sheet is transferred at a controlled speed depending on printing conditions by a transfer belt 352 that is looped and provided facing an ink-droplet-propelling side of the print heads 312 . While, an image is formed on the sheet by ink droplets propelled from the print heads 312 by lines. The transfer belt 352 has a transfer belt move-down mechanism 354 capable of moving the transfer belt 352 downward. The transfer belt move-down mechanism 354 moves the transfer belt 352 downward so that sheets around the transfer belt 352 are easily removed when a transfer jam and multi-feeding of sheets is detected. [0032] For one-side printing, a sheet printed on a front side is transferred in the casing by drive mechanisms such as rollers. Then, the sheet is guided to the face-down discharge tray 330 a to be discharged by a route selecting mechanism 386 , and stacked on the face-down discharge tray 330 a with a printed side down. [0033] The face-down discharge tray 330 a is formed in a shape of a tray protruding from the casing with a certain thickness. The face-down discharge tray 330 a is inclined to a lateral wall of the casing. Thus, the discharged sheet is slid down along an inclination of the face-down discharge tray 330 a so as to tidily pile up on the face-down discharge tray 330 a in due course. [0034] The face-down discharge tray 330 a has a prearranged sheet pile-up capacity. Thus, the face-down discharge tray 330 a is provided with a tray full sensor 332 a to detect whether sheets being piled up on the face-down discharge tray 330 a reaches a predetermined level near the maximum pile-up capacity. Concurrently, the face-down discharge tray 330 a is provided with a tray empty sensor 334 a to detect whether the face-down discharge tray 330 a is empty. [0035] For both-side printing, assuming “a front side” as the side to be printed first and “a back side” as the side to be printed next, a sheet printed on the front side is to be transferred in the casing without being guided to the face-down discharge tray 330 a by the route selecting mechanism 386 . The sheet is transferred to the inversion route SR to be switched back for inversion between the front side and the back side. The sheet is re-fed to the register R by the drive mechanisms such as rollers. After a pause at the register R, the sheet is transferred to the printing mechanism at a controlled timing. [0036] Then, the sheet is to have an image formed on the back side in a similar manner to the front side. The sheet with images on both sides is discharged to and piled on the face-down discharge tray 330 a. [0037] In the printing apparatus 10 , an internal space of the face-down discharge tray 330 a is used to implement a switchback for both-side printing. The space in the face-down discharge tray 330 a is enclosed to keep sheets from being taken from outside in the course of the switchback. This prevents the sheets from being pulled out by a mistake of user in the course of the switchback. The face-down discharge tray 330 a , which is an inherent member to the printing apparatus 10 , affords to eliminate provision of an extra space for the switchback in the printing apparatus 10 . This permits the casing to be kept from being enlarged in size. The inverting route SR that is separated from the face-down discharge tray 330 a allows for parallel operations between a sheet to be switched back and another sheet to be discharged. [0038] FIG. 5 is a block diagram showing a configuration of an edge part and multi-feeding sheet detection system, which serves as a detector to detect edge parts and multi-feeding of sheets. As shown in the figure, the edge part and multi-feed sheet detection system is composed of the second light transmission sensor 170 , an edge part detector 180 , a multi-feed determiner 190 and an encoder 196 . As described above, the second light transmission sensor 170 is provided on the sheet exit side of the register rollers 250 . The encoder 196 outputs a one-shot pulse signal when the register rollers 250 are rotated a predetermined length of a sheet sent thereby. [0039] The second light transmission sensor 170 includes the light emitter 172 , and the light-receiving sensor 174 provided so as to receive light emitted from the light emitter 172 and output an electrical signal according to the amount of the received light. The light emitter 172 can be composed of a light-emitting diode, a laser diode, a lamp, and the like. The light-receiving sensor 174 can be composed of, for instance, a photo diode. [0040] When there is no sheet between the light emitter 172 and the light-receiving sensor 174 , the light-receiving sensor 174 directly receives light emitted from the light emitter 172 . While, the light-receiving sensor 174 indirectly receives light emitted from the light emitter 172 through a sheet (or sheets) when there is any sheet therebetween. Therefore, the received light amount of the light-receiving sensor 174 is dependent on the presence or absence of sheet, the number of sheets, a sheet thickness, etc. Thus, the passage of a front edge part, the passage of a back edge part and the multi-feeding of sheets are detectable based on the electrical signal transmitted from the light-receiving sensor 174 . Note that other types of sensors, such as a light reflection sensor, may be appropriately used instead of a light transmission sensor. [0041] The edge part detector 180 includes a comparator 182 . The comparator 182 compares an output signal from the light-receiving sensor 174 with a predetermined voltage value to determine the presence or absence of sheet. Then, the comparator 182 outputs the comparative result as an edge part detection signal. Thus, the edge part detector 180 can detect front and back edge parts of a sheet passing through the second light transmission sensor 170 by monitoring a rising edge and a trailing edge of the edge part detection signal from the comparator 182 . [0042] The multi-feed detector 190 includes an analog amplifier circuit 191 , an A/D converter 192 , a sampling circuit 193 , a memory 194 and a judging circuit 195 . Those functional components are realized as hardware by means of the controller 110 composed of a CPU, RAM, ROM, integrated circuit, and the like. [0043] The analog amplifier circuit 191 amplifies an output signal based on the received light amount of the light-receiving sensor 174 so as to transmit to the A/D converter 192 . The A/D converter 192 converts the signal from the analog amplifier circuit 191 into a digital signal based on the analog value so as to transmit to the sampling circuit 193 . The sampling circuit 193 samples the digital signal from the A/D converter 192 at a controlled timing based on a one-shot pulse signal from the encoder 196 so as to store in the memory 194 . [0044] Next, we explain a method of multi-feed detection of the present embodiment. According to the present invention as shown in FIG. 6 , a sheet P is segmented into “N” detection blocks along a sheet transfer direction. Then, each detection block is assigned with “n” sampling points. The number “N” of the detection blocks is determined depending on the length of the sheet P along the sheet transfer direction. Preferably, the sheet P is segmented so as to leave a certain margin at a mostfront edge part on the sheet P in view of a response lag of the light-receiving sensor 174 . [0045] Then, an output signal from the A/D converter 192 per sampling point in one detection block is sampled to obtain sampling data. After every sampling data of the sampling points in the detection block is obtained, an average value of the sampling data in the detection block is calculated. [0046] By comparing the calculated average value with a reference value preliminarily assigned in the detection block, the possibility that multi-feeding happens in the detection block is predicted. When there are two sequential detection blocks predicted to have a possibility from multi-feeding, a multi-feed detection signal is transmitted due to the determination of multi-feeding of sheets. The judging circuit 195 serves as a component to execute calculation processing of the average value of sampling data, prediction processing of a possibility for multi-feeding, and determination processing of multi-feeding. [0047] Next, we explain a reference value in prediction processing of a possibility for multi-feeding. After first sheet feeding, the average value of sampling data per detection block calculated in first sheet feeding is used as a reference value of each corresponding detection block of a second sheet and the following sheets. In other words, multi-feeding of sheets after first sheet feeding is determined based on sampling data of a first sheet P. For the first sheet P, it is employed a predetermined common initial value as a reference value for each detection block. Such an initial value as a reference value varies based on types of sheets. Thus, for instance, several initial values may be arranged in advance according to the type of the sheet P. [0048] Therefore, the memory 194 has a section to store “n” sampling data to be calculated per detection block, a section to store “N” reference values of respective detection blocks, and a section to preliminarily store an initial reference value. [0049] Then, we describe a flow of multi-feed determination processing in the multi-feed determiner 190 . FIG. 7 is a flow chart showing multi-feed determination processing in first sheet feeding. [0050] When the second light transmission sensor 170 detects a front edge part of a first sheet after feeding (S 101 : Yes), a sampling point in a first detection block is determined based on a one-shot pulse signal transmitted from the encoder 196 (S 102 ). Then, an output signal from the A/D converter 192 on the sampling point is sampled so as to store in the memory 194 as sampling data (S 103 ). After “n” sampling data are stored in the memory 194 by repeating such a sampling per sampling point in the detection block (S 104 : Yes), the average value of the sampling data in the detection block is calculated (S 105 ). [0051] When the calculated average value in the detection block is less than a predetermined initial reference value (i.e. the received light amount is small) (S 106 : Yes), a possibility from multi-feeding is predicted. In such a case, the possibility is further judged whether to meet a multi-feed determining condition (S 109 ). The multi-feed determining condition is defined as a condition that when there are two sequential detection blocks predicted to have a possibility for multi-feeding, it is determined that multi-feeding of sheets occurs. Note that other multi-feed determining conditions may be applicable. For instance, multi-feeding of sheets may be determined when more than half of detection blocks are determined as ones having a possibility for multi-feeding. [0052] When the multi-feed determining condition is met as a result of the judgment (S 109 : Yes), a multi-feed detection signal is transmitted (S 110 ). According to the transmitted signal, the printing apparatus 10 executes multi-feed control processing (S 111 ). Multi-feed control processing means for instance that sheet feeding is stopped so as to move the transfer belt 253 downward by the transfer belt move-down mechanism 354 . Thus, sheets are placed on the transfer belt moved downward so that a user can easily remove the sheets from the printing apparatus 10 . [0053] When the calculated average value in the detection block is more than the predetermined initial reference value (i.e. the received light amount is large) (S 106 : No), or when the multi-feed determining condition is not met (S 109 : No), the calculated average value is stored in the memory 194 as a reference value of the detection block (S 107 ). [0054] Then, the multi-feed determiner 190 executes multi-feed determination processing repeatedly (starting from the step S 102 ) until a back edge part of the sheet is detected (S 108 ). When the second light transmission sensor 170 detects the back edge part of the sheet (S 108 : Yes), multi-feed determination processing in first sheet feeding is completed. [0055] Next, we explain multi-feed determination processing of a following sheet after first sheet feeding with reference to a flow chart in FIG. 8 . [0056] When the second light transmission sensor 170 detects a front edge part of a following sheet after first sheet feeding (S 201 : Yes), a sampling point in a first detection block is determined based on a one-shot pulse signal transmitted from the encoder 196 (S 202 ). Then, an output signal from the A/D converter 192 on the sampling point is sampled so as to store in the memory 194 as sampling data (S 203 ). After “n” sampling data are stored in the memory 194 by repeating such a sampling per sampling point in the detection block (S 204 : Yes), the average value of the sampling data in the detection block is calculated (S 205 ). [0057] When the calculated average value in the detection block is less than the reference value of the corresponding detection block determined in first sheet feeding (i.e. the received light amount is small) (S 106 : Yes), a possibility for multi-feeding is predicted. In such a case, the possibility is further judged whether to meet a multi-feed determining condition (S 209 ). Note that the similar multi-feed determining condition to the first sheet can be employed in this feeding. [0058] When the multi-feed determining condition is met as a result of the judgment (S 209 : Yes), a multi-feed detection signal is transmitted (S 210 ). According to the transmitted signal, the printing apparatus 10 executes multi-feed control processing (S 211 ). Note that multi-feed control processing similar to the first sheet can be employed in this feeding. [0059] When the calculated average value in the detection block is more than the reference value (i.e. the received light amount is large) (S 206 : No), or when the multi-feed determining condition is not met (S 209 : No), the multi-feed determiner 190 executes multi-feed determination processing repeatedly (starting from the step S 202 ) until a back edge part of the sheet is detected (S 207 ). When the second light transmission sensor 170 detects the back edge part of the sheet (S 207 : Yes), the multi-feed determiner 190 determines whether a sheet is still following (S 208 ). When there is another following sheet (S 208 : Yes), the multi-feed determiner 190 repeats multi-feed determination processing starting from front edge part detection processing (S 201 ). While, when there is no following sheet (S 208 : No), multi-feed determination processing after first sheet feeding is completed. [0060] According to the present embodiment as described above, the printing apparatus 10 employs the second light transmission sensor 170 as a multi-feed detection sensor provided on the sheet exit side of the register rollers 250 in order to detect edge parts of a sheet. Thus, it is possible to improve the accuracy of multi-feed detection. [0061] While preferred embodiments of the present invention have been described using specific terms, such description is for illustrative purposes, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims. [0062] This application is based upon the Japanese Patent Application No. 2008-226285, filed on Sep. 3, 2008, the entire content of which is incorporated by reference herein.

A printing apparatus includes: a printing mechanism forming an image on a sheet transferred in a sheet transfer route; a sheet feeding mechanism feeding sheets to the sheet transfer route; a register provided between the sheet feeding mechanism and the printing mechanism on the sheet transfer route so as to position a sheet fed from the sheet feeding mechanism and adjust an obliqueness of the sheet; an edge part detector provided on the sheet transfer route having a detecting section configured between the register and the printing mechanism so as to detect edge parts of a sheet transferred to the printing mechanism by the register, wherein the edge part detector is configured to serve as a multi-feed detector to detect multi-feeding of sheets.

This is a division of application Ser. No. 380,614, filed on July 14, 1989, now U.S. Pat. No. 5,076,838, issued Dec. 31, 1991. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an apparatus and process for producing strong degradation-resistant agglomerates or pellets of mineral ore and, more specifically, to such an apparatus and process which includes passing the agglomerates or pellets through an oxidation zone on a traveling grate prior to being discharged into a kiln having a reducing atmosphere. Once in the kiln, the agglomerates or pellets are first advanced through an induration zone of the kiln in order to provide sufficient strength to the agglomerates or pellets passing therethrough to enable them to better withstand stress in a reduction zone of the kiln in order to improve the physical characteristics of the pellets and, therefore, the yield. 2. Description of the Prior Art U.S. Pat. No. 3,753,682 is directed to a ported rotary kiln process for direct reduction of oxides and sulfides of metallic materials to increase the metallic content thereof. In particular, the apparatus and process disclosed therein is for pre-reduction of mineral ore including a controlled admission of hydrocarbon fuel and oxidizing gases into a rotary kiln for an oxygen reduction treatment which is not intended to produce liquid metal but is intended to increase the metallic content of a particle, pellet or agglomerate in a generally solid state by reducing the oxygen content thereof. The oxygen content is reduced in order to provide a pretreated charge material having increased utility in chemical processes requiring a mineral in metallic form or for increasing the capacity and fuel efficiency of subsequent smelting and refining processes. Although the process is primarily used, as suggested above, for metallic materials, those skilled in the materials processing art will recognize that other material may include compounds of elements which are not metallic that can be reduced in a similar manner. Accordingly, references hereinbelow to the reduction of metallic material or to the increase of metal content are equally applicable to other material including compounds of elements which are not actually a metal in order to increase the content of at least one of the elements thereof. In the preferred process taught in U.S. Pat. No. 3,753,682, finely divided iron ore and coal along with bentonite are mixed and rolled into suitable agglomerates or particles by a balling drum which may be of the type shown in U.S. Pat. Nos. 1,994,718 and 2,411,873. The resulting properly-sized green balls, agglomerates or pellets are deposited on the feed end of an oxidizing traveling grate in the oxidizing atmosphere of an oxidation zone. In the oxidation zone, fully oxidized, afterburner exhaust gas from the reduction process is utilized to dry and preheat the green balls or pellets on the grate in successive process regions. Upon leaving an initial drying region of the oxidation zone, the balls may be fully dry but may not be strong enough to survive the transfer into the kiln which has a reduction zone including a reducing atmosphere for reducing the balls or pellets. The traveling grate carries the dry balls or agglomerates or pellets into a preheat region of a higher temperature than the drying region. The pellets or agglomerates can be partially oxidized by their passage through the preheat region and, in turn, can be strengthened for the grate-to-kiln transition and early stages of reduction. The preheated pellets or agglomerates from the oxidation zone are transferred via an enclosed chute from the grate to the reduction zone in a rotary kiln. The prior art rotary kiln is inclined downwardly at a slight angle below horizontal so that, upon rotation, the pellets in a bed at the upper, inlet end of the kiln will tumble and mix as they advance through the kiln. The kiln has axial burners and peripheral ports and may be of a type described in U.S. Pat. No. 3,182,980. With the kiln being disposed at a slight downward angle, the pellets or agglomerates can tumble through the kiln to a chute for discharge to a cooler. Gas flow through the kiln is in the opposite direction of the movement of the pellets or agglomerates therethrough. The gas flow preferably results from fuel and air alternatively being injected into the kiln respectively through the peripheral ports located around and along the length of the kiln. Fuel is only injected into the bed of pellets in the kiln while air is only injected above the bed of pellets. In U.S. Pat. No. 3,753,682, the preferred reducing agent is natural gas which is primarily introduced into the kiln through the peripheral ports located below the bed of the pellets or agglomerates. As the pellets or agglomerates move axially through the kiln, the fuel ports in the periphery of the kiln pass beneath the bed of pellets or agglomerates. Natural gas, substantially free of any oxidizing gases, is passed through the ports and into the bed to make initial and intimate contact with the pellets or agglomerates which are at a temperature of about 2000 degrees Fahrenheit. The contact of such gases with the pellets or agglomerates in an oxide form at such a high temperature causes a portion of the gas to quickly pyrolytically decompose with an amount thereof being reformed as a strong reducing agent including, for example, carbon monoxide and hydrogen. At the same time, air is introduced into the peripheral ports above the bed in order to support combustion of the non-oxidized products of reduction that issue from the charge. This combustion provides heat to sustain operating temperature in the kiln and, because of the remaining chemical energy in exhaust gases therefrom, furnishes the necessary fuel for the afterburner and subsequent heat for the oxidation on the traveling grate in the oxidation zone. After reduction in the kiln, the pellets or agglomerates which contain significantly increased metallic fractions are directed to a cooler. After being cooled, the resulting material is screened, sized and separated for determining what portion of the material is properly processed and what portion must be discarded or recycled. Another apparatus disclosed in U.S. Pat. No. 3,753,682 uses prehardened agglomerates or particles which are provided to a hopper and then fed through a hood into the upper end of a ported rotary kiln. The kiln is provided with an unported preheat section followed by the reduction zone thereof which is provided with the peripheral ports for the introduction of natural gas and air. The kiln may be of the type described in U.S. Pat. No. 3,182,980 and the contents thereof may be discharged to an indirect cooler which may be of the type shown in U.S. Pat. No. 2,792,298. The pellets or agglomerates may be previously heat hardened by such systems as are disclosed in U.S. Pat. Nos. 2,750,272: 2,750,273: 2,750,274 or 2,925,336. It is also suggested in U.S. Pat. No. 3,753,682 that either of the embodiments disclosed therein may incorporate an addition of coal with the ore as the ore leaves the oxidation zone of the traveling grate before the pellets are reduced in the reduction zone of the kiln. Additional and more detailed features of the preferred ported rotary kiln system are disclosed in "The Direct Reduction of Iron Ores With The ACCAR SYSTEM" and "Five Hundred Tonne Per Day ACCAR Direct Reduction Plant at Orissa, India" which were published by the Allis-Chalmers Corporation. ACCAR and ACCAR SYSTEM were trademarks of the Allis-Chalmers Corporation and are presently the trademarks of Boliden Allis, Incorporated. The systems disclosed in these publications can employ gases, liquid or solid fuels singly or in combination to obtain the desired reduction of iron ores. In both systems, coal is preferably fed to the inlet of the rotary kiln with the ore charge. Additionally, these publications include an explanation of the use of a coal slinger at the outlet end of the rotary kiln for the introduction of a quantity of coal to the interior thereof. Still further, additional details are provided to explain the screening, magnetic separation of the unburned coal (char) and reduced pellets, and distribution of the material after it is discharged from the cooler. "GRATE-CAR Direct Reduction System From Allis-Chalmers" and "GRATE-CAR System For Pyro-processing Ferrous And Other Ores With Solid And/Or Fluid Fuels" were published by Allis-Chalmers Corporation to disclose an improved overall system for the direct reduction for material therein. GRATE-CAR was a trademark of Allis-Chalmers Corporation and is presently the trademark of Boliden Allis, Incorporated. As discussed in these publications, direct reduction feed stock traditionally included lump ore and/or iron oxide pellets which were fed at ambient temperature to a reduction vessel. This required that part of the vessel, whether a rotary or shaft kiln, be used as a preheater to elevate the feed stock to reaction temperature. As explained therein, conventional iron ore pelletizing and reduction processes employed two separate plants. In the pelletizing plant, the pelletized concentrate was heat treated and cooled. The pellets at ambient temperature were then fed to a reduction plant. With the development of the GRATE-CAR system, the pelletizing plant cooler was eliminated to result in a capital cost saving and a simplified process flow sheet. The charging of hot pellets to a rotary kiln also resulted in an energy savings. Still further, a smaller rotary kiln could be employed because additional kiln volume for pellet preheating would no longer appear to be required. Generally, the GRATE-CAR system disclosed in the aforementioned publications consists of a traveling grate, a ported or nonported rotary kiln and a cooler connected in series. Pelletized concentrate is fed to the oxidizing traveling grate for drying and preheating in order to provide strength to the pellets. The hot preheated pellets are then fed directly into the rotary kiln. Solid fuel such as coal or other processing agents can be added to the grate discharge along with the pellets to the rotary kiln. In the case of a ported kiln, natural gas, oil or other fluid fuels can be introduced through the ports. Pellets discharging from the lower end of the kiln are cooled in a cooler. One aspect of the GRATE-CAR system employs a kiln firing hood at the lower, discharge end of the rotary kiln which is designed to include a coal slinger. The coal slinger includes a pneumatic coal injection system which delivers coal to the downhill one-third or one-half of the kiln. The purpose of injecting the coal in this manner is to supplement the coal fed with the preheated pellets and to maximize the use of coal volatiles in the kiln. The reduced product and char discharge from the kiln into a rotary cooler where the material is cooled to about fifty degrees centigrade. The main control factors in the process are kiln temperature, exhaust gas composition and product quality. The optimum reducing condition for the kiln is maintained by adjusting the quantity of fuel and air inputs until a balance is achieved between the solids retention time in the kiln, temperature and product quality. A specific installation which serves as an example of the GRATE-CAR system is described and disclosed in a publication entitled "Ilmenite Direct Reduction Project In Norway Using The GRATE-CAR Process" and published by Boliden Allis, Inc. It should be recognized that some particular ores may be capable of being reduced by the prior art processes without producing any unacceptable fines which must be discarded or reprocessed. However, for many such ores, throughout the reduction processes described hereinabove, there is continuing concern regarding the strength and integrity of the pellets as they are passing through the oxidizing zone and into the reduction zone. Generally, throughout the reduction processes discussed hereinabove, there are various temperature, porosity and chemical changes to such green balls, pellets, or agglomerates which significantly affect their overall physical characteristics such as strength and subsequent ability to be properly reduced in order to produce a product of high metal content. Although the reduction in the systems described above is preferably provided in a ported or non-ported rotary kiln which is downwardly inclined to advance the pellets therethrough, the use of other kiln systems with other means for advancing the pellets would also depend on the integrity of the pellets for proper reduction. Accordingly, there remains a need for any apparatus or process which can be employed to further improve the overall physical characteristics, such as the overall strength, of the pellets to further insure their proper integrity as they are reduced in a kiln and subsequently discharged in a form having a higher metal content. The above listed patents and publications are incorporated by reference as if the entire contents thereof were fully set forth herein. OBJECTS OF THE INVENTION It is an object of the present invention to provide a process and apparatus for the reduction of pellets including means for improving the physical characteristics of the pellets prior to subjecting the pellets to a reducing environment. It is another object of the invention to provide such a process and apparatus which will increase the pellet yield of the material by minimizing the degradation of the pellets during the reduction. It is still a further object of the invention to provide such a process and apparatus which will provide heat hardening of the pellets of material prior to their being reduced. It is yet another object of the invention to provide a process and apparatus to reduce the fine contents resulting from the reduction process. SUMMARY OF THE INVENTION These and other objects of the invention are provided in a preferred process for directly reducing pellets without melting the material. The process includes the steps of drying and preheating the pellets with an oxidizing gas on a traveling grate; discharging the pellets from the oxidizing traveling grate to a substantially adjacent first end of a kiln; and advancing the pellets through the kiln from the first end to the second end thereof. The advancing of the pellets includes initial advancing of the pellets through an induration zone of the kiln having an environment and being at a temperature to indurate the pellets. The induration zone of the kiln is adjacent to the first end and remote from the second end and extends for a substantial portion of the kiln from the first end. The process also includes the steps of indurating the pellets in the induration zone during the initial advancing. There is further advancing of the pellets from the induration zone after the indurating through a reduction zone of the kiln extending substantially from a downstream end of the induration zone to the second end of the kiln. Additional steps include injecting a reducing agent into the reduction zone for contact with the pellets in the reduction zone and reducing the pellets during the further advancing through the reduction zone. The indurating of the pellets includes retaining the pellets in the induration zone during the initial advancing therethrough with the pellets being substantially free of contact with the reducing agent. Other objects of the invention are provided by a preferred apparatus for directly reducing pellets of material without melting the material. The apparatus includes a heating and oxidizing component and an element for transporting the pellets through the heating and oxidizing component for heating and oxidizing the pellets. A kiln has a first end and a second end with the first end being substantially adjacent to the heating and oxidizing component. The pellets are discharged from the heating and oxidizing component to the first end of the kiln. There is an arrangement for advancing the pellets through the kiln from the first end to the second end thereof. An induration zone in the kiln is for indurating the pellets and the induration zone is adjacent to the first end and remote from the second end and extends for a substantial portion of the kiln from the first end. The kiln includes a reduction zone extending from the downstream end of the induration zone to the second end of the kiln. There is included devices for injecting a reducing agent into the reduction zone of the kiln for making contact with the pellets advancing through the reduction zone and for assisting in the reduction of the pellets in the reduction zone. The pellets are advanced through the induration zone during induration thereof with the pellets therein being substantially free of contact with the reducing agent. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic, simplified view of the prior art GRATE-CAR system for generally pelletizing, drying, preheating, reducing, and cooling pellets of metal bearing material. FIG. 2 is a schematic view of a portion of an apparatus for reducing metal bearing material without melting the material including a preferred induration zone and various features of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS As seen in FIG. 1, the GRATE-CAR system 11 of the prior art includes the combination of a binder to ore fines for forming green balls in a balling drum. The green balls of metal bearing material are deposited on a traveling grate for conveyance through a drying and preheating region of an oxidation zone 13. The preheated pellets of the material are then transported to the adjacent end 15 of a rotary kiln. In the rotary kiln, fuel and air are added to cause a reduction of the pellets as they slowly advance by rotation from the first end 15 to the second end 17 of the inclined rotary kiln. The hot pellets of reduced material are then transferred to a rotary cooler to reduce the temperature thereof. The output from the rotary cooler is then advanced for proper screening, separation and collection of the desired finished product and various by-products. Although the schematic view of FIG. 1 generally represents the major components of the prior art GRATE-CAR system, additional features clearly shown in the patents and documents incorporated by reference and discussed above should be discussed prior to a description of the preferred invention. For example, after the pellets are basically formed in the balling drum and prior to advancement to the traveling grate, the green balls are properly sized at 19 in a roller classifier with oversized balls being fractured and returned into the feed bins. The traveling grate and the oxidation zone 13 are primarily divided into drying and preheating sections or regions. Although not always required, the drying section may include an updraft drying portion where the gases flow upwardly therethrough and a downdraft drying portion where the gases flow downwardly therethrough. The preheat portion of the oxidation zone 13 is intended, after drying, to further raise the temperature and improve the physical characteristics of the pellets of material therein for preventing shock and degradation upon entry into the rotary kiln. Again, although not shown in detail in FIG. 1, the exhaust gases from the rotary kiln are generally removed at a chute area 21 between the traveling gate and the first end 15 of the kiln rather than being passed directly to the traveling grate. However, the exhaust gases are at least partially used, after being fully oxidized, for flow through the preheat region of the oxidation zone of the traveling grate and for the updraft drying and downdraft drying regions thereof. Additionally, between the traveling grate and the rotary kiln, as the pellets are being transferred in the chute area 21 from the traveling grate to the first end 15 of the rotary kiln, fuel, preferably in the form of coal, is added in order to be mixed with the pellets to provide the primary source of the reducing agent for reducing the pellets or particles of material in the rotary kiln. Additionally, fuel in the form of gas or liquid may be added to the rotary kiln through ports in the lower region thereof for flow through the bed of pellets or particles in the kiln. Air is supplied to the interior of the rotary kiln through the ports above the bed. The air is used to combust the exhaust reduction gases in the kiln to produce sufficient heat in the system for proper reduction in the kiln and for drying and preheating the pellets on the traveling grate in the oxidation zone. Still further, some installations include a coal slinger at the second, lower end 17 of the rotary kiln for the injection of coal. The coal slinger injects the coal about one-third to about one-half of the length of the kiln from the second end 17 thereof. As generally described, the GRATE-CAR system of the prior art utilizes the traveling grate to dry and preheat balled concentrate prior to its transfer into the ported or non-ported rotary kiln. The hot pellets, which have improved physical strength because of the drying and preheating, are typically accompanied by an addition of solid fuel in the transfer chute 21 between the traveling grate and the first end 15 of the rotary kiln to allow the reduction reaction to proceed almost upon entry into the rotary kiln. The exhaust gases exhausting from the rotary kiln at the first end 15 thereof are combusted in an afterburner chamber (not shown) so that an oxidizing gas stream is available for process requirements associated with the drying and preheating sections of the oxidizing traveling grate 13. As seen in FIG. 2, the preferred system 8 includes additional means for further improvement of the physical characteristics, such as strength, of the pellets prior to subjecting the pellets to an intimate reducing environment and the ensuing pellet stresses attendant with that environment while further improving the potential for a significantly higher pellet yield. It should be recognized that some of the components shown in FIG. 2 are in simplified form and may be altered or modified to include specific features or equipment as suggested by the various patents and publications incorporated by reference hereinabove. In the preferred embodiment, green balls or pellets 10 are deposited on an oxidizing traveling or moving grate 12 which advances through an oxidizing or oxidation zone 14. The green balls or pellets 10 are preferably formed by a balling drum and a roller classifier as discussed above. The pellets 10 advance on the grate 12 through a drying region 16 and a preheat region 18 of the oxidation zone 14. In order to properly dry and preheat the pellets 10, the preferred oxidation zone 14 basically uses exhaust gases from the reduction zone 38. Generally, the exhaust gases are fully oxidized by the use of an afterburner 20 in an exhaust gas stack 22. At least a portion of the fully oxidized exhaust gas is directed by flow lines 24 and associated fans 26 to cause the heated gas to flow through the preheat region 18 and the drying region 16. It should be kept in mind that the embodiment shown in FIG. 2 is in simplified form and some installations may include the introduction of outside air into the system for proper control of the temperature and/or to provide an excess quantity of oxygen to insure full oxidation of the gases to be used on the grate in the oxidation zone 14. Still further, other modifications may include the exhaust gases (with the ambient air added thereto) initially passing through the preheat region 18 and then being further directed to an updraft drying region and/or a downdraft drying zone of the drying section 16. Generally, exhaust gases which have been used for preheating and drying as well as the remainder of the exhaust gases from the afterburner 20 are combined for further processing, heat removal and cleaning prior to discharge to the atmosphere. After the pellets 10 have advanced through the drying region 16 and the preheat region 18 of the grate 12 in the oxidation zone 14, they proceed to a transition chute 28 between the grate 12 of the oxidation zone 14 and a preferred rotary kiln 30. As discussed above, some of the systems described in the prior art patents and publications incorporated by reference employ a transition chute for the addition of a solid fuel such as coal directly to the preheated pellets for combined entry into the first end of the rotary kiln. The amount of solid fuel added by this means can vary but may include as much as fifty to one hundred percent of the total fuel employed in the reduction process. Consequently, the introduction of the solid fuel or coal in this manner in the prior art caused the reduction reaction to proceed almost upon entry into the first end of the rotary kiln. However, the preferred invention includes an induration zone 34 in the rotary kiln 30 at a first end 32 thereof to provide further stabilization and strengthening of the pellets prior to them being brought into intimate contact with any reducing agent. As will be seen, the pellets are heat hardened in the induration zone 34. The heat which directly contributes to induration is also needed for the reduction in the reduction zone 38 when the pellets 10 are in intimate contact with a reducing agent. If the reducing agent were present in the induration zone 34, the material in the heated pellets would begin to reduce. Accordingly, rather than introducing coal or any other reducing agent at the transition chute 28, the preferred invention includes means for initially advancing the pellets 10 through the induration zone 34, including an initial portion of the kiln 30, in a stabilizing, heated environment substantially free of either oxidation or reduction by insuring that the pellets are substantially free of any contact with coal or any other reducing agent. As a result, the reducing agent, which is in the form of coal in the preferred embodiment, is injected into the kiln by a coal slinger (not shown) or other type of coal-propelling system discussed hereinabove. A discharge end 36 of the coal slinger extends into the rotary kiln 30 for discharge into the interior of the rotary kiln at the first end 32 thereof. The coal leaving the discharge end 36 at the first end 32 is provided sufficient velocity to propel the coal inwardly of the rotary kiln beyond the induration zone 34 to the reduction zone 38 of the kiln 30. As a result, the pellets 10 will advance through the induration zone 34 with substantially no coal in the bed of pellets 10 for contact and possible reaction therebetween. Coal slingers of the type described are well known in the minerals processing art and may be of the same type discussed in the patents and publications incorporated by reference for the introduction of coal to the second or discharge end of a rotary kiln. Allowing the pellets 10 to form the bed at the first end 32 of the rotary kiln 30 without the inclusion of any reducing agent therein provides further strength improvement of the pellets after they have discharged from the preheat region 18 of the traveling grate. Accordingly, the pellets 10 are heat hardened in the induration zone 34. Advancing the pellets for some time in the induration zone 34 without the presence of a reducing agent insures further induration or strengthening of the pellets 10 prior to their reduction in the reduction zone 38 of the rotary kiln 30. The rotating action of the rotary kiln will cause the pellets 10 at the upper end of the kiln to be continuously mixed as they slowly progress down the inclined interior surfaces thereof. The slow advancement of the pellets through the induration zone 34 provides the desired time after the preheating on the grate in the oxidation zone 14 for the pellets 10 to be further strengthened prior to their advancement into the reduction zone 38. Heat is required for both the induration and the reduction of the pellets. In the preferred process, the rotary kiln 30 is a ported rotary kiln which allows the introduction of air into the upper or overbed region of the reduction zone 38 of the rotary kiln 30. The air is introduced through a series of nozzles 40 arranged around and along the rotary kiln. A control system (not shown) insures that the air is directed to the region above the bed rather than through the bed of pellets 10. The air is used to combust the reduction exhaust gases so that the resulting heat, in the form of hot reduction exhaust gas, will pass through the interior of the kiln and out the exhaust gas stack 22. The heated exhaust gas provides the heat required for proper induration and, as discussed above, also provides heat for the drying region 16 and preheat region 18 of the traveling grate in the oxidizing zone 14. As the hot exhaust gases pass over the bed of pellets 10 in the induration zone 34, there is no significant chemical reaction therebetween as the heat is simply absorbed by the pellets 10 for the desired induration period. Still further, the heated pellets 10 from the induration zone are at a sufficient temperature for proper reduction in the reduction zone 38 when the pellets 10 are brought into intimate contact with the reducing agent. Accordingly, once the pellets 10 are by continuous advancement delivered to the reduction zone 38 of the rotary kiln 30, the addition of the coal, or other reducing agent, into the continuously mixing bed of heated pellets 10 provides proper contact therebetween for reduction of the pellets. Although the preferred system employs the reducing agent in the form of coal, it should be recognized that ported rotary kilns of the type described can also be used for the introduction of a reducing agent in the form of gas or oil or any combination thereof including the coal. For this purpose, the preferred ported rotary kiln 30 includes an array of nozzles 42 at the lower region of the rotary kiln 30 in the reduction zone 38 for the introduction of gas or oil. The gas or oil is supplied by a control system (not shown) to the array of nozzles 42 which are below the bed of pellets 10 to insure that the reducing agent will filter and pass through the pellets 10 for intimate contact therebetween in the reduction zone 38. Still further, as mentioned above, coal could be provided to the reduction zone through a coal slinger or the like (not shown) at the discharge end of the rotary kiln 30. Such a coal slinger would not be expected to project the coal beyond the center region of the kiln and therefore would not be expected to project the coal to the induration zone 34. Reduction of the pellets in the reduction zone 38 in the manner described, after their having been strengthened and heat hardened in the induration zone 34, enables the pellets 10 to further withstand the tumbling and advancing action of the rotary kiln throughout the reduction process in the reduction zone 38. Consequently, more of the pellets are properly reduced for subsequent cooling and collection upon exit from the rotary kiln 30 and the reduction zone 38 thereof. As a result, the preferred invention increases the pellet yield so that more of the highly concentrated material is in a proper pellet form for effective use in subsequent processes. In order to better understand the preferred embodiment of the invention as discussed above, it is appropriate to discuss some details of an existing process which is being used in Tyssedal, Norway and could be altered to include the improvements of the present invention if the pellets discharging from the grate were determined to have an inferior physical quality. Specifically, the detailed process employed in Tyssedal, Norway is disclosed in the publication entitled "Ilmenite Direct Reduction Project In Norway Using The GRATE-CAR Process" and discussed hereinabove. Generally, in this process, pelletized ilmenite concentrate is fed to a traveling grate where the pellets are dried and preheated using fully oxidized kiln exhaust gas. The hot preheated pellets are fed directly to a ported kiln for eventual reduction of the iron oxide to metallic iron in the presence of lump coal. The reduced pellets and coal char are discharged from the kiln to an indirect rotary drum cooler. The purpose of the plant is to prepare pellet products having a high metallic content for use as feed stock to an electric arc smelting furnace. A primary product of this particular plant includes titanium slag containing 70%-75% titanium dioxide (TiO 2 ). The slag is shipped to users where it is further processed into a titanium dioxide pigment for use as a whitener in paint, paper and plastic products. The by-product of the smelting operation is a pig iron which is sold to steelmakers and foundries. In order to determine the proper coal to be used in the process, coal ranging from lignites to high quality bituminous was tested. The results of the test demonstrated that all coals were acceptable with respect to the quality of product achieved. However, the test data confirmed that no usable recyclable char could be retrieved from the use of lignite because of the severe degradation. However, with one pass through the kiln, the bituminous coals did generate coarse char with the amount and quality of char fractions substantial enough to consider it for use by recycling. Generally, the ilmenite ore is passed through a grinding mill and pumped to a slurry tank to form a 62% solid slurry. The slurry is pumped through filters to form filter cakes containing about 9.5% moisture. About seven and one-half kilograms of bentonite are mixed with each ton of filter cake and conveyed to a balling feed bin. The mixture is then fed to a long rubber lined balling drum for green ball formation. The drum discharge is deposited into a roller classifier which eventually results in properly sized 9 by 16 mm green balls which can be directed to the traveling grate. The preferred grate is about 2.8 m wide and about 21 m long for carrying a bed of green balls 225 mm deep. The preferred process gas used in the various zones on the grate is generated in an afterburner chamber mounted vertically at the grate-kiln interface. The afterburner chamber receives kiln exhaust gas laden with unburned coal volatiles. This exhaust gas is at a temperature of about 800° C. to about 900° C. Air is radially blown into the afterburner to completely oxide the volatiles and to maintain this gas at a temperature of about 800° C. to about 1100° C. The resultant waste gas contains about 8% to about 10% oxygen as it leaves the afterburner chamber. Approximately 35% of the gas is used in the oxidizing zone on the grate with the balance being sent to the waste gas handling system. However, prior to the gas reaching the pellet bed, it is tempered with a bleed-in of ambient air to about 700° C. to about 800° C. In this particular example, the gas in this system is cooled by the pellets and then is split into two streams and induced through a downdraft and an updraft drying zone before being recombined with the balance of the afterburner exhaust gas. In the Tyssedal, Norway process, the preferred rotary kiln has an overall diameter of about 5.8 m and may be from about 71.5 m to about 100 m long with tapered feed and discharge ends. The induration zone would include about 10% to about 35% of the overall length of the kiln which might vary from as little as 50 m to as much as about 110 m depending on the type of material being processed. The reduction zone would include about 65% to about 90% of the overall length of the kiln. The preferred kiln is lined with about 228 mm thick castable refractory. The kiln is erected at a slope of about 2 percent as it slightly extends downwardly from the first or feed end and is supported by a plurality of carrying rollers. The kiln can include a plurality of ports which are spaced in an orderly pattern along the length of the reduction zone of the kiln and around the girth of the kiln. Preferably, the ports are arranged in a plurality of rows with each port extending through the kiln shell and ending at the inside refractory surface. The purpose of the ports is to deliver radially directed process air along the length of the reduction zone of the kiln. This air combusts the gas which evolves from the coal in the bed of the kiln. The amount and placement of the air through the ports determines the shape of the temperature profile in the kiln. The total air flow is simultaneously injected through selected numbers of rows of ports which are positioned above the bed depending upon the demand of the current operation. Typically, the rotary kiln will rotate at a speed between 0.25 rpm and 0.75 rpm with the pellets typically requiring 7 to 8 hours to advance therethrough. The total time the pellets remain in the kiln can depend on the material being reduced therein and could range from as low as two hours to as high as ten hours. As a result, it would be expected for the pellets to preferably remain in the induration zone for a period of time ranging from about one hour to two hours. However, depending on the ore being processed, it would not be unusual for the pellets to remain in the induration zone for a period of time ranging from about one-fourth of an hour to about three-and-one-half hours. For example, some material may be preferably indurated for one-half to one hour while others for one and one-half to two-and-one-half hours or for two to three hours. Downstream of the preferred kiln is a 4.1 m diameter by 66 m long rotary cooler. Cooling of the product is done indirectly by water flow on the outside of the cooler shell. As a result, the product is cooled from about 1000° C. to about 50° C. While the process described hereinabove for Tyssedal, Norway provides a specific example of the application of the present invention for the formation of pellets having a high concentration of iron, it should be recognized to those skilled in the minerals processing art that any number of other materials might be used in the preferred process of the present invention. For example, it should be clear that the preferred process and apparatus could be employed for improving the metallic content of lumps, particles, briquettes, or agglomerates of material selected from a group consisting of the oxides and sulfides of iron, nickel, zinc, copper, manganese, and chrome. It would, for example, be possible to include briquettes which are as large as 2 inches by 2 inches by 2 inches for proper oxidation, induration and reduction in the above-described process. It may also, for example, be possible for the preferred process to be employed for material including oxides and/or sulfides of titanium and/or phosphorus. Depending on the type of material being oxidized and reduced, the temperature of the traveling grate may range from about 600° C. to about 1000° C. The temperature produced in the reduction zone would typically be 1000° C. to 1100° C. but, again, depending on the particular metal being processed may be as low as 700° C. or as high as 1200° C. to 1500° C. For example, some material may be properly reduced at temperatures between 800° C. and 900° C., 900° C. and 1000° C., or 1100° C. and 1200° C. in order to drive the reduction reaction to a desired completion. The addition of the air to the reduction zone produces oxidation of the reduction gases for heating of the reduction zone and the induration zone. The amount of air remaining in the exhaust reduction gases after such oxidation would typically be less than 1% as it passes through the induration zone. The exhaust gases in the reduction zone do not generally react chemically with the pellets in the induration zone but simply transfer heat to the pellets in the bed as it passes through the upper region thereof prior to entrance into the afterburner. Although the example and the preferred embodiment mentioned hereinabove employ a coal delivery slinger system for the introduction of solid fuel in the form of coal through the induration zone for mixing with the pellets in the reduction zone, it should be recognized that typical reduction processes of the type described can be performed by the use of a reducing agent in the form of oil, gas or a solid reducing material or any combination thereof. Clearly, the introduction of any of these types of reducing agents should be limited to the reduction zone so that the pellets passing through the induration zone are substantially free of any contact of the reducing agent in the induration zone. The preferred process discussed hereinabove is intended to produce chemically proper agglomerates or pellets with a desired metal content but are, as mentioned above, also intended to produce such agglomerates or pellets which have sufficient physical or structural integrity for further processing after the oxidation-reduction process discussed above. Accordingly, the primary intent of such an oxidation-reduction process is to maximize the pellet yield by insuring that there is a minimum amount of fines produced during the process. In some such systems, it would not be uncommon for the fines to include 3% to 10% of the product yield. On the other hand, depending on the material being processed, yields which may include 20% fines would be undesirable and the use of the preferred process as discussed hereinabove could reduce such undesired fines to about 5% of the total yield of the oxidation-reduction process. The invention as described hereinabove in the context of a preferred embodiment is not to be taken as limited to all of the provided details thereof, since modifications and variations thereof may be made without departing from the spirit and scope of the invention.

An apparatus for directly reducing pellets of material without melting the material includes the transporting of the pellets through drying and preheating zones on an oxidizing traveling grate and reduction in a ported rotary kiln. There is a kiln having a first end and a second end with the first end being substantially adjacent to the heating and oxidizing component for receipt of the pellets therefrom. The kiln is inclined downwardly and is rotated to advance the pellets through the kiln from the first end to the second end therefrom. The kiln includes an induration zone for indurating the pellets. The induration zone is adjacent to the first end and remote from the second end and extends for a substantial portion of the kiln from the first end. The kiln includes a reduction zone extending from the downstream end of the induration zone to the second end. A device is used to inject a reducing agent into the reduction zone of its kiln for making contact with the pellets advancing through the reduction zone. The kiln is heated to assist in a reduction of the pellets in the reduction zone. The pellets advancing through the induration zone are substantially free of contact with the reducing agent. The invention also includes the process for directly reducing the pellets of material.

CROSS-REFERENCE TO A RELATED APPLICATION The invention described and claimed hereinbelow is also described in European Patent Application EP 07023808.4 filed Dec. 8, 2007. This European Patent Application, subject matter of which is incorporated herein by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d). BACKGROUND OF THE INVENTION One known device for regulating a medium (European Patent Disclosure EP 1 536 169 A1) has a valve housing with a valve inlet and a valve outlet as well as a valve opening, located between the valve inlet and the valve outlet, that is surrounded by a valve seat. The valve opening and the valve seat are located in a valve chamber. The valve seat, for opening and closing the valve opening, cooperates with a valve member that is secured to the face end of an armature of an electromagnet, the armature protruding into the valve chamber. The armature is guided axially displaceably in a guide sleeve, which in turn is inserted into the valve chamber and is sealed off in it from the chamber wall. A valve closing spring is located in a blind bore of the armature and is braced on one end on the armature and on the other on an adjusting pin that is accessible from the outside, and when the electromagnet is not excited, the valve closing spring, via the armature, presses the valve member against the valve seat. When current is supplied to the electromagnet, the armature is displaced axially counter to the spring force of the valve closing spring, and the armature lifts the valve member from the valve seat, thus uncovering the valve opening, and depending on the stroke of the valve member, a greater or lesser quantity of a medium flows from the valve inlet to the valve outlet via the valve chamber. The valve chamber is constantly filled with medium, so that the valve member and the face end of the armature are always bathed by the medium. SUMMARY OF THE INVENTION The object of the invention is to disclose a device for regulating the flow of a liquid or gaseous medium of the type defined at the outset, which with strict separation from the medium of the actuating device for the valve member that controls the flow of the medium, is sturdy and has a long service life. The device according to the invention has the advantage of a structurally stable valve member, and by the subdivision into a closing body, bathed by the medium, and a frame separated from the medium, the actuating device engaging the frame, to the magnitude of the flow of medium, does not come into contact with the flow of the medium for actuating the closing body. Thus the device can be used with long service lives for the regulating the flow of aggressive gaseous or liquid media. The valve member can be manufactured economically, especially whenever, in a preferred embodiment of the invention, the frame and the support of the closing body as well as the ribs that join the frame and the support are manufactured as a one-piece stamping from a metal sheet, and the regions of the valve member exposed to the medium, that is, the support, are covered with a coating, for instance of plastic, rubber, an elastomer, or the like. Further special characteristics of the invention and features of the subject of the invention will become apparent from the further claims and the ensuing description. In an advantageous embodiment of the invention, a further valve inlet and a further valve opening, surrounded by a further valve seat, are provided in the valve housing. Two sealing faces cooperating with both valve seats are embodied, transversely spaced apart from ribs, on the coating of the closing body. With the pivot bearing of the valve member in the valve housing, done via the ribs, a double-seat valve controlled by a single valve member and having two separate valve inlets and one common valve outlet can be implemented in a simple way, and the valve inlets can be made to communicate in alternation with the valve outlet. The invention is described in further detail below in terms of an exemplary embodiment shown in the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view of a device for regulating the flow of a fluid; FIG. 2 is a longitudinal section through a device in FIG. 1 ; FIG. 3 is a view from below of a valve member of the device in the direction of the arrow III in FIG. 2 ; and FIG. 4 is a section taken along the line IV-IV in FIG. 3 . DESCRIPTION OF THE PREFERRED EMBODIMENT The device shown in FIGS. 1 and 2 for regulating the flow of a fluid or flowing medium, such as a liquid or gaseous medium, has a two-part valve housing 11 , which is composed of an upper housing part 12 and a lower housing part 13 . The medium flows through the lower housing part 13 , while in the upper housing part 12 , an actuating device 14 , separated from the medium, is received at least partly for regulating the flow of the medium. In the lower housing part 13 of the valve housing 11 , on sides facing away from one another, two valve inlets 15 , 16 and one valve outlet 17 located between them are provided. Between the valve inlet 15 and the valve outlet 17 , there is a first valve opening 18 , and between the valve inlet 16 and the valve outlet 17 , there is a second valve opening 19 . The axes of the two valve openings 18 , 19 are oriented parallel to one another. Both valve openings 18 , 19 are located in a valve chamber 20 , which is embodied at the interface between the upper housing part 12 and the lower housing part 13 ; an upper part of the valve chamber 20 is machined into the upper housing part 12 , and a lower part of the valve chamber 20 is machined into the lower housing part 13 . The first valve opening 18 is surrounded by a first valve seat 21 , and the second valve opening 19 is surrounded by a second valve seat 22 , in each case concentrically. The two valve openings 18 , 19 are controlled by a single valve member 23 , and in alternation, one valve opening 18 is uncovered and the other valve opening 19 is closed. The valve member 23 is actuated by the actuating device 14 , which will be described in further detail hereinafter; when the actuating device 14 is inactive, the valve member 23 closes the first valve opening 18 and uncovers the second valve opening 19 , as is shown in FIG. 2 . The valve member 23 has a closing body 24 , located in the valve chamber 20 , that cooperates with the valve seats 21 , 22 , and it also has a frame 25 , separated from the medium and surrounding the closing body 24 with spacing, that is solidly joined to the closing body 24 . The frame 25 is located in a hollow chamber 26 surrounding the valve chamber 20 . The hollow chamber 26 is likewise located at the interface between the two housing parts 12 , 13 ; an upper part of the ringlike hollow chamber 26 is machined into the upper housing part 12 , and a lower part of the hollow chamber 26 is machined into the lower housing part 13 . The valve chamber 20 and the hollow chamber 26 are hermetically separated from one another by a closed-ringlike seal 27 that is fixed between the two housing parts 12 , 13 . The closing body 24 has a flat cross-shaped support 28 and a coating 29 , for instance of plastic, rubber, an elastomer, or the like, that sheathes the support 28 . The frame 25 is rigidly joined to the two shorter arms of the crosslike support 28 via ribs 30 , 31 , for instance two in number, diametrically opposite one another centrally on the frame 25 , and the ribs 30 , 31 penetrate the seal 27 transversely to its longitudinal direction, and after fastening of the seal 27 between the two housing parts 12 , 13 , they form a pivot bearing for the valve member 23 . Holes 32 and 33 are made on the ends of each of the two longer arms of the cross in the support 28 . In the production of the coating 29 that sheathes the support 28 , the holes 32 , 33 are filled with plastic, and in the region of the holes 32 , 33 on the underside of the coating 29 , facing toward the valve seats 21 , 22 , sealing faces 34 , 35 are embodied that cooperate with the valve seats 21 , 22 . The valve seats 21 , 22 , on sides of the pivot bearing of the valve member 23 facing away from one another and located at the same spacing from it and offset from one another, are plane and have different vertical spacings from the pivot bearing; the vertical spacing of the second valve seat 22 is greater than that of the first valve seat 21 . The term vertical spacing is understood to mean the spacing of the plane, in which the plane valve seat 21 or 22 is located, from the pivot bearing. The sealing face 34 cooperating with the first valve seat 21 is oriented parallel to the plane of the frame 25 and support 28 , while the sealing face 35 that cooperates with the second valve seat 22 , which is offset relative to the first valve seat 21 , is oriented at an acute angle to the plane of the frame 25 and support 28 . The positioning angle of the sealing face 35 corresponds to the pivot angle of the valve member 23 by which the valve member 23 , is pivoted in order to close the second valve opening 19 and uncover the first valve opening 18 . The frame 25 , the support 28 , and the two ribs 30 , 31 joining them to one another are produced in one piece as a stamping from a metal sheet. The coating 29 is advantageously produced by extrusion coating of the support 28 , for instance with plastic, rubber, an elastomer, or the like. In the extrusion coating of the support 28 , simultaneously the closed-ringlike seal 27 , which covers the ribs 30 , 31 on both sides that extend from the frame 25 to the support 28 and are in one piece with the frame 25 and the support 28 , is produced jointly from the same material. It is understood that it is possible to provide the valve housing 11 with only one valve inlet, such as the valve inlet 15 , and the valve outlet 17 , with the valve member 23 remaining unchanged, but in that case the second sealing face 35 is omitted. The valve member actuating device 14 , placed on the upper housing cap 12 of the valve housing 11 and received partly in the upper housing part 12 , has a valve closing spring 36 and an actuator 37 , with a drive member 38 for the valve member 23 , the drive member operating counter to the force of the valve closing spring 36 . The actuator 37 is placed on the upper housing part 12 and with a guide sleeve 44 for the drive member 38 it dips into a receiving chamber 45 embodied in the upper housing part 12 . A pressure fork 39 with two tines 391 is located on the face end of the drive member 38 . The two tines 391 , as a result of the spring force of the valve closing spring 36 engaging the drive member 38 , rest on two points of the frame 25 , which are diametrically opposite one another at the first valve opening 18 . In FIG. 3 , solely for the sake of clarity, these two points are shown in dashed lines on the frame 25 and are marked 251 . In the exemplary embodiment shown, the pressure fork 39 is inserted loosely into a central face-end recess 40 . At the same time, a further pressure fork 41 is guided axially displaceably with two tines 411 ( FIGS. 1 and 2 ) in a guide shaft 42 that is machined into the upper housing part 12 of the valve housing 11 . The tines 411 of the further pressure fork 41 also rest on the frame 25 , specifically at two points 252 opposite one another at the second valve opening 19 , and are pressed against the frame 25 by a compression spring 43 , which is slipped onto the stem of the pressure fork 41 , and are braced on one end on the pressure fork 41 and on the other on the housing. The spring force of the compression spring 43 is less than the spring force of the valve closing spring 36 , and thus the further pressure fork 41 is not capable of pressing the valve member 23 , with the sealing face 35 , onto the second valve seat 22 until, by axial displacement of the drive member 38 , the closing force of the valve closing spring 36 , acting on the valve closing member 23 at the site of the first valve opening 18 , has been rescinded. A cover plate 46 , placed on the top of the upper housing part 12 and screwed in the valve housing 11 , closes off both the receiving chamber 45 , with fixation of the guide sleeve 44 , and the guide shaft 42 of the further pressure fork 41 , and the compression spring 43 seated on the pressure fork 41 is braced on the cover plate 46 . If the actuator 37 is inactive, then the valve member 23 assumes its position in FIG. 2 , in which the sealing face 34 is pressed by the valve closing spring 36 against the first valve seat 21 at the first valve opening 18 , and the sealing face 35 is lifted from the second valve seat 22 at the second valve opening 19 . In this case, a flow course is opened up from the valve inlet 16 to the valve outlet 17 , and the flow course from the valve inlet 15 to the valve outlet 17 is blocked. If the actuator 37 is activated, then the drive member 38 is displaced upward, counter to the force of the valve closing spring 36 . By the spring force of the compression spring 43 , the pressure fork 41 pivots the valve member 23 about the pivot bearing at the ribs 30 , 31 and presses the valve member 23 , with the sealing face 35 , onto the second valve seat 22 at the second valve opening 19 . The flow course from the valve inlet 16 to the valve outlet 17 is blocked, and the flow course from the valve inlet 15 to the valve outlet 17 is opened. In the exemplary embodiment described here, the actuator 37 is embodied as an electromagnet 47 , with an exciter coil 48 surrounding the guide sleeve 44 , a magnet core 49 that dips into the guide sleeve 44 , and an armature 50 that is axially displaceable in the guide sleeve 44 and that forms the drive member 38 of the actuator 37 . However, a piezoelectric, magnetostrictive, pneumatic, or similarly functioning actuator may be used as the actuator 37 instead. In the described device for regulating the flow of a liquid or gaseous medium, manual actuation for uncovering the first valve opening 18 in the event of failure of the actuator 37 or for starting up the device without auxiliary energy is provided for. The manual actuation may be a rotatable, locking, or similar motion. In the exemplary embodiment shown with sliding actuation, the manual actuation involves has a sliding key 52 , which is displaceable counter to the force of a restoring spring 51 and which has a sliding wedge. When the sliding key 52 is pressed inward counter to the force of the restoring spring 51 , the sliding wedge slides underneath the pressure fork 39 and lifts it from the valve member 23 counter to the force of the valve closing spring 36 , so that by means of the compression spring 43 , the valve member 23 can be pivoted, thereby uncovering the first valve opening 18 .

The invention relates to a device for regulating the flow of a liquid or gaseous medium, having a valve housing ( 11 ), which has at least one valve inlet ( 15, 16 ) and a valve outlet ( 17 ) as well as at least one valve opening ( 18, 19 ), located between the two and surrounded by a valve seat ( 21, 22 ); having a valve member ( 23 ) controlling the valve opening ( 18, 19 ); and having a valve member actuating device ( 14 ), which has a valve closing spring ( 36 ) and an actuator ( 37 ) operating counter to the valve closing spring. For creating a robust device with a long service life, and in which the valve member actuating device ( 14 ) is hermetically separated from the medium, the valve member ( 23 ) has a closing body ( 24 ), cooperating with the at least one valve seat ( 21, 22 ), and a frame ( 25 ), separated from the medium, for engaging the valve member actuating device ( 14 ), which frame surrounds the closing body ( 24 ) and is solidly joined to it.

RELATED APPLICATIONS This application relates to, incorporates by reference, and claims priority from, U.S. Provisional Patent Application Ser. No. 60/112,803 entitled, “Method and Apparatus for Executing Multiple JAVA Applications on a Single JAVA Virtual Machine”, filed Dec. 18, 1998, having inventor Dr. Jürgen G. Kienhöfer. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the field of improved execution environments for software applications running in the JAVA(™) language. In particular, the invention relates to improvements designed to support the operation of multiple unmodified JAVA(™) applications on an unmodified JAVA(™) Virtual Machine. 2. Description of the Related Art 1. Description of Problem JAVA(™) applications are transportable byte codes that can be executed on a number of platforms. The execution environment for JAVA(™) applications is a JAVA(™) Virtual Machine (JVM). For each platform a JVM must be available to execute the JAVA(™) applications. The specification of, and the implementation of, a JVM is described in documents such as “JAVA(™) Virtual Machine”, John Meyer and Troy Downing, O'Reilly and Associates, 1997. Additionally, the book “The JAVA(™) Virtual Machine Specification”, Tim Lindholm and Frank Yellin, Addison Wesley, 1997, also describes a JVM. For each JAVA(™) application that a user wishes to run on a JAVA(™) Virtual Machine, a separate JVM must be run together with a separate execution environment. This execution environment includes an object store in memory, also referred to as a JAVA(™) heap, for storing JAVA(™) objects and data. Also, the environment includes a “garbage collector” that deletes unused objects and compacts the JAVA(™) heap. This arrangement consumes large amounts of system memory or each JVM, and thus each application. When used, as JAVA(™) was originally designed on a client computer, this is riot a problem as a user is typically running only one or two applications at a time. Further, the user's computer is dedicated to running those applications. In contrast, server computers may require that multiple JAVA(™) applications be running simultaneously. For example, a server might be deployed to handle processing for a large number of client computers. If the JAVA(™) standard is followed, each of running JAVA(™) application on the server would need to run in separate JVM's, each with an associated execution environment. Thus, each application would have its own JAVA(™) heap and separate garbage collection process. The multiplicity of the garbage collection processes across all of the JVM's can consume significant amounts of processor time and lead to decreased performance. The JAVA(™) Virtual Machine could be rewritten in its entirety to support multiple applications at one time. However, such an approach would require major re-architecting of the JAVA(™) and/or JVM standards and specifications. Additionally, JAVA(™) applications could be rewritten in source code to support multiple applications on a single JVM. 2. Prior Art JAVA(™) Execution Environment Turning to FIG. 1 , and the prior art JAVA(™) execution environment, the execution environment includes a JAVA(™) Virtual Machine 100 , including JAVA(™) base classes 102 and a primordial class loader 104 . An optional application class loader 106 is depicted as well as a single JAVA(™) application 108 . This is the typical JAVA(™) execution environment according to the prior art. In the normal operation of a JVM, a JAVA(™) application compiled to run on the JVM arrives in a sequence of byte codes arranged in class files. The class files, which can be remotely or locally accessed, are loaded by class loaders and executed in a threaded environment by the JVM. Execution of JAVA(™) applications take place in threads, which are part of thread groups, and invokes calls to methods of the associated objects. Each thread that is created from a thread in a given thread group also belongs to that thread group. Executions of thread causes the creation of objects, which are stored in portions of the JAVA(™) heap during run time. An application is able to run on a JAVA(™) execution environment with a large set of JAVA(™) base classes, which are sometimes considered part of the JVM. The base classes received calls from the application to enable many basic functions. Object creation during execution within the JVM utilizes a class loader architecture. There are two types of class loaders in the JAVA(™) execution environment. The first type is a “primordial” class loader, e.g. the primordial class loader 104 . The primordial class loader is considered part of the JVM itself and is designed to load certain class loaders. Usually the primordial class loader 104 is used to load classes of the application. Another type of class loader is available for loading objects. This type of class loader is a JAVA(™) class loader object written in JAVA(™). This type of class loader can be installed by a JAVA(™) application into a thread. When this type of class loader is installed into a thread other application objects within that thread are loaded using that class loader. Notably the prior art JVM does not allow for a hierarchy of application class loaders. Thus, a JAVA(™) application such as the JAVA(™) application 108 cannot install additional application class loaders. 3. Conclusion The prior techniques do not permit the execution of multiple unmodified JAVA(™) applications on a single unmodified JAVA(™) Virtual Machine. Further, the prior techniques do not support shared usage of the JAVA(™) base classes by applications running on the JVM. Accordingly, what is needed is a method and apparatus for supporting multiple unmodified JAVA(™) applications on a single JVM using a single copy of the base classes for all of the JAVA(™) applications. SUMMARY OF THE INVENTION A modified JAVA(™) execution environment is described. The modified environment supports multiple JAVA(™) applications on a single JAVA(™) virtual machine (JVM). This modified environment provides significant memory and performance improvements when running multiple applications on a single computer system. Notably, no changes are needed to the source code of an application to take advantage of the modified environment. Further, embodiments of the invention may support shared access to base classes through the use of overlays. Additionally, system resource permissions can be enforced based upon the user permissions associated with a running application. Notably, embodiments of the invention allow multiple applications to share the abstract window toolkit (AWT) on a per display basis. Since only a single garbage collection routine is necessary, applications see improved performance relative to running in different JVMs. Further, the shared base classes eliminate significant memory overhead. According to some embodiments of the invention, a class loader and a thread group is dynamically generated for each application to be run in the modified environment. This class loader defines a name space for the application. Additionally, the thread group defines the set of threads for that application. The class loader also loads the application classes into the JVM. The application itself can have an application class loader, an application security manager, and/or create additional thread groups. As necessary, when the overlaid base classes are called, the calling application can be determined. Two approaches are used by some embodiments of the invention. In the first approach, the class loader of the calling method is determined. This in turn allows the identification of the application through reference to data associated with the class loader. Another approach is to scan the thread group hierarchy of the JVM to identify a thread group with which application information has been associated by the class loader. Once the application is identified, the underlying base class functionality can be implemented using the appropriately selected files, resources, variable values, etc. Additionally, embodiments of the invention can support system resource permissions, e.g. user access rights, on a per application basis. Each application can be associated with a user. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 illustrates a JAVA(™) Virtual Machine environment according to the prior art. FIG. 2 illustrates a JAVA(™) Virtual Machine environment according to one embodiment of the invention. DETAILED DESCRIPTION The modified JAVA(™) execution environment supported by embodiments of the invention will be described with reference to FIGS. 1 and 2 . FIG. 1 shows the JAVA(™) execution environment according to the prior art and was described above. FIG. 2 shows the JAVA(™) execution environment according to one embodiment of the invention and will now be described in greater detail. FIG. 2 shows the modified JAVA(™) execution environment according to one embodiment of the invention. Elements of FIG. 2 that are found in FIG. 1 are designated with the same reference numerals. For example, FIG. 2 includes the JVM 100 . The JVM 100 used in FIG. 2 may be identical to the JVM 100 used in FIG. 1 , but should at least be a substantially unmodified JVM. The term “substantially unmodified” as used in this application refers to a JVM or JAVA(™) application suitable for use in the prior art JAVA(™) execution environment of FIG. 1 . For example, a JVM supporting just in time (JIT) that can execute substantially unmodified JAVA(™) applications would be a substantially unmodified JVM. One further example may be instructive. A JAVA(™) application 108 is substantially unmodified, if it can be used in the execution environment of FIG. 1 without the need for source code—or byte code—modifications to run in the execution environment of FIG. 2 . Examples of substantially unmodified JVMs usable according to embodiments of the invention include JVMs from Sun Microsystems, Mountain View, Calif.; JVMs from Microsoft Corporation, Redmond, Wash.; JVMs from Apple Computer Corporation, Cupertino, Calif.; and/or other available JVMs. For the purposes of this discussion it will be assumed that the JAVA(™) Virtual Machine complies with a JAVA(™) standard and that the JAVA(™) applications similarly comply with a JAVA(™) standard. The elements of FIG. 2 will now be described in greater detail. The substantially unmodified JVM 100 supports the modified execution environment of FIG. 2 . The substantially unmodified JVM 100 includes base classes 102 . The base classes 102 are substantially unmodified base classes suitable for use in a standard JAVA(™) execution environment such as the JAVA(™) execution environment of FIG. 1 . Additionally, FIG. 2 includes base class overlays 200 . The base class overlays 200 provides support for multiple JAVA(™) applications using only a single copy of the base class 102 . The base class overlays 200 , allow multiple applications to reference the base classes 102 without conflicts due to different access privileges and/or base class definitions that inhibit sharing. The base class overlays 200 will be described in further detail below. The modified JAVA(™) execution environment also includes a primordial class loader 104 that is substantially unmodified and suitable for use according to the prior art JAVA(™) execution environment. The modified JAVA(™) execution environment includes a multiple application class loader 206 . This class loader provides support for multiple applications. Additionally, a security manager 204 provides for different degrees of access to different applications based on privileges. The multiple application class loader 206 handles the class loading of JAVA(™) applications within the modified execution environment of FIG. 2 . Compare this to the standard execution environment of FIG. 1 , where the primordial class loader 104 would load the JAVA(™) application 108 . According to the modified execution environment of FIG. 2 , the multiple application class loader 206 would invoke the JAVA(™) application 108 . In order to support the launch of multiple applications, a launch interface 202 is provided. The launch interface 202 may itself be a JAVA(™) application. The launch interface 202 may provide a command line interface or other interface for invoking the execution of JAVA(™) applications within the modified execution environment of FIG. 2 . The launch interface 202 may itself be loaded by the multiple applications class loader 206 as a JAVA(™) application running within the modified JAVA execution environment. In some embodiments, the launch interface may respond to remote procedure invocations, or some other type of message, and execute applications according to parameters specified in the message. In some embodiments, the launch interface 202 provides a UNIX-style command line interface with log in and security procedures. The depiction of the multiple application class loader 206 as a single class loader for all applications is a simplification. In fact, a class loader is dynamically generated for each application. Thus, the launch interface 102 , the JAVA(™) application 108 , and the JAVA(™) application 108 B each has a dynamically generated multiple application class loader 206 responsible for loading the appropriate application classes. Each of the dynamically generated multiple application class loaders can define its own namespace within which the loaded applications will execute. As shown in FIG. 2 , once invoked from the launch interface 202 , JAVA(™) applications (e.g. the JAVA(™) application 108 ) can have their respective classes loaded within the modified execution environment of FIG. 2 . Similarly a second application, the JAVA(™) application 108 B could be loaded within the modified execution environment of FIG. 2 . These two applications would be sharing the same JAVA(™) Virtual Machine 100 and the same base classes 102 . However, the multiple application class loader 104 would place them in separate namespaces and would place them in different thread groups. The base class overlays 200 ensure appropriate behavior of the base classes 102 for each of the applications. Notably, neither the JAVA(™) application 108 nor the JAVA(™) application 108 B need to be modified at the source code level to operate within the modified execution environment. The environment of FIG. 2 is transparent to JAVA(™) applications running in the environment. The modified execution environment of FIG. 2 only needs a single garbage collection process and a single copy of the base classes 102 . This provides significant memory and speed savings. In some experiments, this reduced the memory overhead to enable execution of over one hundred JAVA(™) applications on a single JVM—on a single server computer, which would otherwise support only fourteen of these applications at the same time. See also, Jürgen G. Kienhöfer, “Java Junction: Perkup, SCO Server Side Java Technology”, in SCO Coredump, Summer 1999, Number 13, page 8, also available at <http://www.sco.com/developer/core13/perkup.htm>. The security manager 204 is an addition to the inherent security models of JAVA(™). Prior art JVMs were typically invoked on client machines by a specific user and the single application ran with that user's privileges. In contrast, the execution environment of FIG. 2 would typically be invoked with system privileges such as “root” on UNIX-like systems. As a result, each running application would, without additional security, be capable of accessing the entire system. Therefore, a security manager 204 can be provided to enforce operating system security—or other security—requirements. In one embodiment of the invention, the security manager 204 uses parameters provided via the launch interface 202 to control the permissions granted to running applications. For example, if using the launch interface 202 an application is invoked using the privileges of “user 1”, the security manager 204 would enforce operating system file permissions and resource permissions for that application according to the privileges granted to “user 1”. Examples of enforced requirements include those for: reading, writing, creating, deleting, modifying, or examining system resources such as files and sockets; listening or accepting network connections to a reserved port; executing a program on the system or starting a sub process terminating the JAVA(™) run time environment of FIG. 2 loading dynamic libraries and native methods. Thus if the permissions on a particular file “x” indicate that it is owned by “user 2” and not readable by other users, an attempt by a JAVA(™) application running as “user 1” to read the file may be denied. Each application running in the environment of FIG. 2 may also have its own security management policies—for example, a set of JAVA(™) sandbox policies. Part of the base class overlays 200 involves the separation of certain resources that are not effectively shared between different programs. For example, the standard java.lang.system class uses static variables to define the input, output and errors streams. As a result, it is not possible to share that class without modification of the base classes. In this instance, the base class can be overlaid with modifications that can use two possible processes—possibly in conjunction with one another—to determine the current application and provide appropriate access to the shared base class. One process used by overlaid, or shared, classes to identify the correct application is to identify the class loader for the calling thread. If the class loader is an instance of the dynamically generated multiple application class loader, then it together with the namespace can be used to identify the application. Consequently, the correct resource permissions, list of accessible files, input and output devices, etc., are identified for use by the shared class. The above approach may fail if the class loader for the object accessing the overlaid class is the primordial class loader 104 . In that instance, the associated namespace may not provide adequate information to suitably identify the application and needed information. Therefore, a second approach to determining the calling process can be used. In this case, the thread data structures within the JVM 100 can be examined to determine the calling object's thread. Then, the group for the thread can be identified. Information associated with the thread group about the application and its properties can then be identified. If necessary, the thread group hierarchy can be recursively examined until a thread group is found that is associated with information about the process. As seen in the execution environment of FIG. 2 , the multiple application class loader 206 does extend the JVM 100 to support application class loaders in addition to the multiple application class loader 206 . In some embodiments, it is necessary to configure the JVM not check for multiple class loaders to enable this capability. In other embodiments this change is not necessary if the JVM itself already supports hierarchies of class loaders. The base class overlays 200 may involve adding checks for resource permissions. For example, the procedures for reading file must be overlaid to include identification of the user for the application, as described above, as well as verification of the user's rights with respect to that file. These changes to the base classes may be implemented in the base class overlays 200 , in the security manager 204 , or in a combination of the two. The terms “program”, or “computer program”, as used in this application, refers to any sequence of instructions designed for execution on a computer system. A program may include a subroutine, a function, a procedure, an object method, an object implementation, an executable application, an applet, a servlet, a source code, an object code, and/or some other sequence of instructions designed for execution on a computer system. The base class overlays 200 , the multiple application class loader 206 , and the security manager 204 may be embodied as one or programs included in one or more computer usable media such as CD-ROMs, floppy disks, or other media. Some embodiments of the invention are included in an electromagnetic wave form. The electromagnetic waveform comprises information such as base class overlays, a multiple application class loader, and a security manger for use in a modified JAVA(™) execution environment. The electromagnetic waveform may include the multiple application class loader accessed over a network. The foregoing description of various embodiments of the invention has been presented for purposes of illustration and description. It is not intended to limit the invention to the precise forms disclosed. Many modifications and equivalent arrangements will be apparent.

A modified JAVA(™) execution environment is described. The modified environment supports multiple JAVA(™) applications on a single JAVA(™) virtual machine (JVM). This modified environment provides significant memory and performance improvements when running multiple applications on a single computer system. Notably, no changes are needed to the source code of an application to take advantage of the modified environment. Further, embodiments of the invention may support shared access to base classes through the use of overlays. Additionally, system resource permissions can be enforced based upon the user permissions associated with a running application. Notably, embodiments of the invention allow multiple applications to share the abstract window toolkit (AWT) on a per display basis. Since only a single garbage collection routine is necessary, applications see improved performance relative to running in different JVMs. Further, the shared base classes eliminate significant memory overhead.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention pertains generally to devices adapted to being mounted on the wheels of a vehicle to improve traction on slippery surfaces and, more particularly, to an apparatus which can be installed and removed without raising or moving the vehicle and which can easily be adjusted to fit a variety of sizes of vehicle wheels. 2. Description of the Background Art Various devices have been developed for installation on the wheels of a vehicle to improve traction on slippery surfaces. For example, U.S. Pat. No. 3,249,143 issued to Scott on May 3, 1966 discloses a traction device for mounting on vehicle tires without jacking the vehicle. It comprises arms extending from the wheel axis and radially spaced around the tire. The portion of the arm which extends to the tire surface is offset to extend around the tire surface. The arms are adjustable to account for spacing differences. Once installed and the arms are extended, a cover plate is attached over the wheel hub to lock the arms into position. U.S. Pat. No. 4,886,100 issued to Parker, III on Dec. 12, 1989 discloses an anti-skid device adapted to be mounted on vehicle tires comprising hooks which fit around the surface of the tire. The hooks are attached to arms which extend over the outside of the tire and which are held in place by a ring chain. In addition, the hooks can be fitted with cleats, studs and other devices to increase traction on snow and ice. German Patent No. 2,262,011 issued to Gomez on Dec. 19, 1972 discloses a traction device for vehicle tires having cleats spaced radially along the surface of the tire and connected to arms which are connected to a centrifugal hub. The arms rotate in guides when the tire spins and tighten the cleats against the tire surface. U.S. Pat. No. 3,935,891 issued to McCloud et al. on Feb. 3, 1976 discloses a traction device for vehicle tires which generally comprises a clamping device mounted on the tire and having a gripping surface on the outer periphery, an adapter plate to which the clamping device is attached, and an optional extension which adds traction surface to the device. The adapter plate is mounted on the wheel of the vehicle and a plurality of clamping devices are attached to the adapter plate, the same being evenly spaced around the tire. The clamping device can have various types of gripping surfaces ranging from cleated plates to studs. U.S. Pat. No. 4,089,359 issued to Jones on May 16, 1978 discloses an assembly mounted on a vehicle tire which comprises a plurality of arms extending radially from the center of the tire to the outer surface, the ends of which have cleats which wrap around the surface of the tire. The arms to which the cleats are attached are telescoping for proper positioning. U.S. Pat. No. 2,598,851 issued to Spevak on Jun. 3, 1952 discloses an emergency traction device which generally comprises a circular plate attached to the wheel of a vehicle and "L" shaped brackets which are in turn attached to the circular plate and extend over the surface of the tire. U.S. Pat. No. 3,045,738 issued to Lombardi on Jul. 24, 1962 discloses a traction device which comprises a circular hub which attached to the wheel of a vehicle and which has "finger brackets" to which "L" shaped clamping brackets containing cleats are attached. U.S. Pat. No. 3,151,654 issued to Minutilla on Oct. 6, 1964 discloses a traction devise comprising a plurality of radially disposed arms which are adjustable to the size of the tire so that they firmly grip the tire adjacent to the road surface but will expand as they leave the road surface. U.S. Pat. No. 3,117,612 issued to Minutilla on Jan. 14, 1964 discloses a traction device which has radially spaced cleats which are locked and retained at high speeds by using centrifugal force to lock them in their guide channels. U.S. Pat. No. 4,278,122 issued to Vagias on Jul. 14, 1981 discloses a traction device comprising a circular hub to which a plurality of traction fingers on supporting shanks are attached and which are equally spaced around the tire. The foregoing patents reflect the state of the art of which the applicant is aware and are tendered with the view toward discharging applicant's acknowledged duty of candor in disclosing information which may be pertinent in the examination of this application. It is respectfully stipulated, however, that none of these patents teach or render obvious, singly or when considered in combination, applicant's claimed invention. SUMMARY OF THE INVENTION The present invention pertains to an apparatus adapted for installation on the outer hub of a wheel on a vehicle for improving traction on slippery surfaces, such as when the road surface is covered with mud, snow, or ice. Unlike conventional chains or snow tires, the apparatus can be installed and removed without having to move or raise the wheels of the vehicle, and can be easily adjusted to fit a variety of sizes of vehicle wheels. By way of example and not of limitation, the apparatus generally comprises a plurality of rectangular traction members which are positioned at evenly spaced points around the tread portion of a tire. The traction members extend transversely across the tread-wall portion of the tire and contain cleat-like surfaces which face outwardly from the tire so as to contact the road surface. These cleats are attached to rectangular arms which are in turn attached to the outer hub of the wheel of the vehicle. Attachment of the support arms to the wheel is made by means of wheel lug extensions and an adapter plate. Once the apparatus is installed, the traction members are adjusted to fit the size of the wheel and tire by means of an adjusting sleeve. Unlike the devices heretofore described, the present invention is universally adaptable to a variety of wheel and tire sizes. Furthermore, the present invention can be more easily removed and installed than the devices disclosed. An object of the invention is to provide an apparatus which will improve traction of the tires of a vehicle when operating on slippery road surfaces. Another object of the invention is to provide a tire traction apparatus which can be easily installed and removed from the wheel of the vehicle. Still another object of the invention is to provide a tire traction apparatus which can be installed and removed from the wheel of a vehicle without having to raise the wheel. Another object of the invention is to provide a tire traction apparatus which can be installed and removed from the wheel of the vehicle without having to move the vehicle. Another object of the invention is to provide a tire traction apparatus which is universally adaptable to the wheels of a variety of vehicles. Another object of the invention is to provide a tire traction apparatus which is unaffected by the thickness of the tire of the vehicle. Still another object of the invention is to provide a tire traction apparatus in which slippage of the apparatus is of no detrimental consequence. Still another object of the invention is to provide a tire traction apparatus which can be stored on a spare tire in a vehicle. Still another object of the invention is to provide a tire traction apparatus with replaceable parts. Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only: FIG 1 is an exploded view of the preferred embodiment of the present invention for use with the wheel and tire assembly shown in phantom. FIG. 2 is a side elevational view of one of the traction members of the apparatus depicted in FIG. 1. FIG. 3 is an exploded view of the locking sleeve mechanism used to fix the position of the traction members of the apparatus depicted in FIG. 1. FIG. 4 is a cross-sectional view of the locking sleeve mechanism shown in FIG. 3. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG. 1. It will be appreciated that the apparatus may vary as to configuration and as to details of the parts without departing from the basic concepts as disclosed herein. FIG. 1 shows the present invention and its use in combination with a vehicle wheel. Wheel 10 may be of conventional form and may include a metal support rim commonly used in vehicles. As schematically illustrated in the exploded view of FIG. 1, an adapter plate 12 is securely fastened to wheel 10 by first installing a plurality of lug extensions 14 on lugs 16 of wheel 10. Lug extension 14 includes a threaded receptacle 18, the threads of which mate with the threads on lug 16, so that lug extension 14 can be securely fastened to lug 16. Adapter plate 12 is secured to wheel 10 by placing openings 20 over the threaded end 22 of lug extensions 14 and fastening nut 24 on lug extension 14 to rigidly secure adapter plate 12 to wheel 10. In the embodiment shown, three lug extensions 14 are used. In selecting the appropriate number to be used, the relative sizes of wheel 10 and adapter plate 12 are taken into consideration. It is desirable to have the weight and force components which are transmitted to adapter plate 12 to be distributed over a number of lugs 16. For most passenger type vehicles and light trucks, three lug extensions 14 are adequate. Adapter plate 12 is a triangular shaped plate with openings 20 located therein as shown. By making openings 20 elongated and positioning them on adapter plate 12 as shown, adapter plate 12 becomes universally mountable to any size of wheel and any lug spacing or configuration commonly found in passenger type vehicles and light trucks. Note, however, that openings 20 can be otherwise positioned on adapter plate 12 as is desirable to fit wheel 10. A plurality of support members 26 are securely fastened to adapter plate 12 by placing openings 28 over mounting post 30 on adapter plate 12. Mounting post 30 is a threaded stud which extends from adapter plate 12 in a direction which is substantially perpendicular to the face of adapter plate 12. Wing nut 32, which includes threaded barrel 34, is then fastened to mounting post 30 to rigidly secure support members 26 to adapter plate 12. Note that threaded barrel 34 extends completely through wing nut 32 so that the length of mounting post 30 is not critical. Support member 26 is elongated and rectangular in shape as shown. The preferred mounting configuration is to join two support members 26 at or near their centers by fitting openings 28 over mounting post 30. It is also preferred to position support members 26 at right angles to each other, thus forming a right angular cross as shown. This is done by positioning support members 26 such that the longitudinal axis between each end of a first support member 26 is substantially perpendicular to the longitudinal axis between each end of a second support member 26. By doing so, traction members 36 will be evenly spaced around tire 38 thereby providing uniform traction. In order to facilitate positioning support members 26 in this configuration, a plurality of guides 40 are attached to support member 26 as shown. Typically, guides 40 are rectangular or square metal tabs placed on each side of opening 28 to form a channel roughly equivalent in width to the width of support member 26. Where support member 26 is made from metal, which is preferred, guides 40 can be welded or otherwise rigidly fastened to support member 26. Alternatively, guides 40 can be formed as an integral part of support member 26 when a casting process is used. Support member 26 may typically be fashioned from one-quarter inch thick metal. Positioned at each end of support member 26 is brace 42 as shown. Brace 42 is a "U-shaped" channel including lips 44a, 44b as its side walls. Lip 44a of brace 42 is located at the end of support member 26 in a direction substantially perpendicular to the face of support member 26. Brace 42 may be made from metal and welded or otherwise rigidly fastened to support member 26, or casted as an integral part of support member 26. Referring now to FIG. 1 and FIG. 2 together, traction member 36 is attached to support member 26 by means of an elongated shank 46 which extends through holes in lips 44a, 44b of brace 42. Shank 46 may be cylindrical or rectangular without affecting operation, but must is preferably cylindrical and three-eights of an inch in diameter. Shank 46 must also slidably engage lips 44a, 44b so that it can be adjusted into the desired position. Shank 46 extends from and is perpendicular to one face of traction member 36, and can be welded to or otherwise attached to traction member 36. Providing stability and preventing rotational movement of traction member 36 are elongated support shafts 48 which are similarly attached to traction member 36 and extend through holes in lips 44a, 44b. Support shafts 48 may also be cylindrical or rectangular in shape so long as they slidably engage lips 44a, 44b and can be moved freely. Referring more specifically to FIG. 3 and FIG. 4, to lock traction member 36 into position sleeve 50 is placed over the end of shank 46 which is toward the center of support member 26. Lock bolt 52 is threaded into a hole in sleeve 50 which has been drilled and tapped to accept lock bolt 52. One end of lock bolt 52 is tabbed for manual rotation whereas the other end is pointed and can be tightened up against shank 46. In the preferred embodiment shank 46 is threaded so that the pointed end of lock bolt 52 can engage the threads in shank 46 as shown in FIG. 4. Adjustment of the position of traction member 36 is straightforward. The user slides traction member 36 in a direction toward the center of wheel 10 until the back face of traction member 36 rests against the tread-wall portion of tire 38. Sleeve 50 is then adjusted to a position which slightly compresses spring 54 which is threaded onto shank 46 between lip 44 and sleeve 50. Spring 54 provides automatic fine adjustment of traction member 36 by retracting traction member 36 toward the center of wheel 10. For quick removal of the apparatus, the user can also pull traction member 36 away from tire 38 because of the spring action and remove the apparatus without having to completely remove traction member 36 or readjust sleeve 50. Quick installation is also facilitated in a similar manner. It is important to note that traction member 36 is typically elongated and rectangular in shape as shown in FIG. 1. In this manner, the width of tire 38 does not require re-sizing of the apparatus as would be required if traction members fit around and over the entire tread-wall portion of tire 38. Traction member 36 extends longitudinally over sufficient surface area of the tread-wall portion of tire 38 so as to permit relatively complete coverage across the tread-wall portion of tire 38. Additionally, traction member 36 has a frictional surface 56 so as to engage the road surface and provide additional traction. Frictional surface 56 may be formed in any manner which provides less than smooth engagement of the road surface. In the preferred embodiment, traction member 36 contains cleats 57 to form frictional surface 56. In operation, slippage of traction members 36 around the surface of tire 38 after engaging the road surface would has no detrimental effect because traction member 36 would still engage the road surface at some point. Instead, such slippage would tend to increase frequency with which traction members 36 actually engage the road surface. Therefore, as an alternative embodiment, bushing 58 could be installed over mounting post 30 and inside of hole 28 as shown in FIG. 1. By using a sealed rotating bushing, bushing 58 would permit rotation of support members 26 around mounting post 30 instead of rigidly attaching support members 26 to adapter plate 12. In this manner, after traction member 36 engages the road surface, the centrifugal force from rotation would pull on spring 54, moving traction member 36 away from the tread-wall portion of tire 38, and thus permitting support member 26 to rotate until another traction member 36 contacts the road surface. Accordingly, it will be seen that this invention provides a universal tire traction apparatus which can be used to improve the traction of vehicles while operating on slippery surfaces. Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of this invention should be determined by the appended claims and their legal equivalents.

A universal tire traction apparatus adapted to being mounted on the outer hub of the wheel of a vehicle generally comprising a plurality of cleat-like members extending transversely to the tread-wall portion of a tire while being supported by a brace assembly attached to an adapter plate mounted on the wheel. The cleat-like members are adapted to be slidably adjustable to fit a variety of wheel and tire sizes.

CROSS REFERENCE AND STATEMENT OF INCORPORATION [0001] This patent application is a continuation-in-part of previously filed co-pending application Ser. No. 12/112,833, filed Apr. 30, 2008, the entire contents of which is incorporated by reference herein. This patent application also relates to co-pending application Ser. No. 11/343,677 filed 31 Jan. 2006 entitled, “SUBCUTANEOUS ICD WITH SEPARATE CARDIAC RHYTHM SENSOR,” the entire contents of which is also incorporated by reference herein. FIELD [0002] The disclosure pertains to cardiac resynchronization therapy (CRT) delivery pacing systems that deliver fusion-based CRT via ventricular pre-excitation. BACKGROUND [0003] It has been shown that in certain patients exhibiting symptoms resulting from congestive heart failure (CHF), cardiac output is enhanced by timing the delivery of a left ventricular (LV) pacing pulse, typically via a lead disposed in a portion of the great cardiac vein to evoke a depolarization of the LV in fusion with the intrinsic depolarization of the right ventricle (RV). The fusion depolarization enhances stroke volume in those hearts in which the RV depolarizes first due to intact atrio-ventricular (AV) conduction, but wherein the AV conducted depolarization of the LV is unduly delayed. The fusion depolarization of the LV is attained by timing the delivery of the LV pace (LVp) pulse to follow the intrinsic depolarization of the RV but to precede the intrinsic depolarization of the LV. [0004] However, due to a number of factors related to the complexity of typical CRT pacers and particularly to the placement of multiple transvenous leads, current CRT systems may not always effectively deliver CRT. The cost and complexity of programming and implanting triple-chamber devices can also pose a barrier to some patients obtaining chronic CRT delivery. [0005] A need therefore exists in the art to simply, efficiently and chronically deliver CRT to patients suffering from various cardiac conduction abnormalities who might not otherwise receive the benefits of CRT therapy. SUMMARY [0006] According to this disclosure, a non-transvenous pacing and, optionally defibrillation device is implanted subcutaneously and oriented to provide pacing therapy from non-transvenous electrodes using leads located exterior to the heart. “Non-transvenous” electrodes include electrodes that are implanted without the need to pas electrode-bearing leads through the vasculature and into the heart. Such leads may include, for example, subcutaneous, pericardial, epicardial and/or myocardial electrodes of any type known to the art. A subject receiving a device according to this disclosure is monitored to confirm a relatively stable bundle branch block or delayed activation of one ventricle. The subcutaneous device having electrodes disposed on the housing and/or having an electrode on a subcutaneous medical lead is oriented so that the pacing vector impinges mainly upon the one ventricle. A preferred mechanism to accomplish this result comprises placement of an electrode on or adjacent the pericardium or epicardium or in the myocardium of the ventricle to be stimulated. [0007] A single pacing stimulus is then delivered upon expiration of an AV interval timed from at least one prior intrinsic atrial event, represented herein as “As” determined from at least one prior “As” that resulted in an intrinsic sensed ventricular event (Vs). The triggering event, As, can emanate from the right atrium (RA) or the left atrium (LA) and the “single” ventricular pacing stimulus is timed to pre-excite the one ventricle so that intra-ventricular mechanical synchrony results. The mechanical synchrony results from the fusing of the two ventricular depolarization wave fronts (i.e., one “paced” and the other more or less intrinsically-conducted). Accordingly, delivery of a single “ventricular” pacing stimulus occurs upon expiration of a fusion-AV or, herein referred to as the pre-excitation interval (“PEI”). One way to express this relationship defines the PEI as being based on an intrinsic AV interval or intervals from an immediately prior cardiac cycle or cycles. Thus, the PEI can be expressed as PEI=AV n−1 −V pei , wherein the AV interval represents the interval from an A-event (As) to the resulting intrinsic depolarization of a ventricle (for a prior cardiac cycle) and the value of PEI equals the desired amount of pre-excitation needed to effect ventricular fusion (expressed in ms). For a patient with LBBB conduction status (for a current cardiac cycle “n”) the above formula can be expressed as: A-LVp n =A-RV n−1 −LV pei and for a patient suffering from RBBB conduction status the formula reduces to: A-RVp n =A-LV n−1 −RV pei . [0008] As noted above, the timing of the single pacing stimulus is an important parameter when delivering therapy according to the foregoing. While a the interval between a single, immediately prior atrial event to a sensed ventricular depolarization can be utilized to set the PEI and derive the timing for delivering pacing, more than a single prior sensed AV interval, a prior PEI, a plurality of prior sensed AV intervals or prior PEIs can be utilized (e.g., mathematically calculated values such as a temporal derived value, a mean value, an averaged value, a median value and the like). Also, a time-weighted value of the foregoing can be employed wherein the most recent values receive additional weight. Alternatively, the PEI can be based upon heart rate (HR), a derived value combining HR with an activity sensor input, P-wave to P-wave timing, R-wave to R-wave timing and the like. Again, these values may be time-weighted in favor of the most, or more, recent events. Of course, other predictive algorithms could be used which would account for variability, slope or trend in AV interval timing and thereby predict AV characteristics. [0009] Among other aspects, this provides an energy-efficient manner of providing single ventricle, pre-excitation fusion-pacing therapy delivered from a non-transvenously implanted medical device generally. A non-contacting (e.g. subcutaneous) electrode pair, for example as disclosed in US Patent Application Publication No. US 2006/0122649 A1 by Ghanem, et al., incorporated herein by reference in its entirety may also be used to practice the invention. Other non-transvenous electrode configurations which deliver a pacing stimulus which can be directed to stimulate a desired ventricle can also be employed, including electrodes associated with a stimulation pulse generator located an or adjacent the outer wall of the heart, as disclosed in U.S. Pat. No. 5,814,089, issued to Stokes, et al. and incorporated herein by reference in its entirety. [0010] In one preferred embodiment, a single epicardial, pericardial or myocardial pacing electrode or electrode pair is deployed to contact with the last-to-depolarize ventricle. The implant procedure for an extra-cardiac ICD (e.g. sub-Q or sub-muscular) used to practice the foregoing—in the pectoral region or infra-clavicular region, in conjunction with the present invention, allows for chronic application of CRT. Preexisting implant leads and tools have been developed that make transcutaneous implants of such electrodes feasible using a sub-xiphoid or infra-clavicular approach. For example U.S. Pat. No. 3,737,579, issued to Bolduc and U.S. Pat. No. 4,010,758, issued to Rockland, et al., both incorporated herein by reference in their entireties disclose such devices. The challenge with regard to obtaining CRT by simply placing an electrode or electrode pair configured to stimulate a single ventricle is that proper CRT can only be delivered if the ventricular pacing pulse is timed to the intrinsic atrial activity and/or the activity of the other ventricle. [0011] A preferred embodiment disclosed herein comprises a single lead extra-vascular system, with the lead electrode or electrodes placed on the LV. Fusion based CRT may be delivered in response to by far-field sensed atrial and ventricular signals (P-waves and R-waves). Fusion pacing algorithms whose basic concepts have already been disclosed could then be applied, for example by monitoring intrinsic A-V intervals and pacing the LV at shorter A-VP intervals. A triggered pacing mode could be a backup mode to fusion if reliable P-waves cannot be detected, triggering an LV pace off of a far-field ventricular sense. Special signal processing (e.g., filtering) techniques are used to accurately determine the P-wave, including detecting an R-wave and then looking back over a window where the P-wave is detected. Additional electrode/lead locations may be used to pick up P-wave and R-wave activity, including extra-vascular leads passing around the chest to the posterior of a subject. [0012] Some features of the disclosure may include: delivery of fusion pacing to a single ventricle using non-transvenously implanted electrodes and far-field sensing of the P-waves; computation of a Fusion A-V pacing interval (P-AV delay) al based on a periodic evaluation of a sensed A-V interval and the use of a pre-excitation interval (PEI); and/or titration of the PEI or detection point on the P-wave based on the resulting paced fusion beat; and a switch from Fusion to triggered pacing if P-waves cannot be reliably detected. The lead attached to the heart may optionally include defibrillation coils to assist in lowering DFTs. Addition of a second non-transvenous lead to deliver biventricular (BiV) pacing is also an option. Substitution of a remote-controlled stimulator mounted to the outer wall of a ventricle for the non-transvenous lead or leads is also possible. [0013] The foregoing and other aspects and features of the present disclosure will be more readily understood from the following detailed description of the embodiments thereof, when considered in conjunction with the drawings which like reference numerals indicate similar structures throughout the several views, and with reference to the claims appearing at the end of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIG. 1 is a schematic diagram of an exemplary subcutaneous device in which the present disclosure may be usefully practiced. [0015] FIG. 2 is a perspective view of a system according to certain embodiments of the disclosure. [0016] FIG. 3A is an exemplary schematic diagram of electronic circuitry within a hermetically sealed housing of a subcutaneous device of the present disclosure. [0017] FIG. 3B is a schematic diagram of signal processing aspects of a subcutaneous device according to an exemplary embodiment of the present disclosure. [0018] FIG. 3C illustrates exemplary subcutaneous and filtered electrogram signals as employed by an exemplary embodiment of the present disclosure. [0019] FIG. 4 illustrates an embodiment of the energy efficient, single-pacing stimulus, ventricular pre-excitation pacing mode according to the present disclosure. [0020] FIG. 5 depicts a process for periodically ceasing delivery of the pre-excitation, single ventricular pacing therapy to determine the cardiac conduction status of a patient and performing steps based on the status. [0021] FIG. 6 illustrates an alternative embodiment to the invention as illustrated in FIGS. 1 and 2 . [0022] FIG. 7 illustrates a second alternative embodiment to the invention as illustrated in FIGS. 1 and 2 . DETAILED DESCRIPTION [0023] In the following detailed description, references are made to illustrative embodiments for carrying out an energy-efficient, single-pacing stimulus, ventricular pre-excitation pacing mode according to the present disclosure. It is understood that other embodiments may be utilized without departing from the scope of the disclosure. For example, examples are disclosed in detail herein in the context of an intrinsically-based or AV sequential (evoked) uni-ventricular pacing system with remote ventricular sensing. This provides an efficient pacing modality for restoring electromechanical ventricular synchrony based upon either atrial-paced or atrial-sensed events particularly for patients with some degree of either chronic, acute or paroxysmal ventricular conduction block (e.g., intraventricular, LBBB, RBBB). A system according to the disclosure efficiently can provide cardiac resynchronization therapy (CRT) with a single pacing stimulus per cardiac cycle. [0024] The following issued U.S. patents are hereby incorporated into this disclosure as if fully set forth herein; namely, U.S. Pat. No. 6,871,096 to Hill, entitled, “System and Method for Bi-Ventricular Fusion-pacing;” issued U.S. Pat. No. 7,254,442 to Pilmeyer and van Gelder entitled, “APPARATUS AND METHODS FOR ‘LEPARS’ INTERVAL-BASED FUSION-PACING;” and U.S. Pat No. 7,181,284 to Burnes and Mullen entitled, “APPARATUS AND METHODS OF ENERGY EFFICIENT, ATRIAL-BASED BI-VENTRICULAR FUSION-PACING.” [0025] FIG. 1 is a schematic diagram of an exemplary device in which the present disclosure may be usefully practiced. As illustrated in FIG. 1 , a device 14 according to an embodiment of the present disclosure is subcutaneously implanted outside the ribcage of a patient 12 , anterior to the cardiac notch. Further, a subcutaneous sensing and cardioversion/defibrillation therapy delivery lead 18 in electrical communication with subcutaneous device 14 is tunneled subcutaneously into a location adjacent to a portion of a latissimus dorsi muscle of patient 12 . Specifically, lead 18 is tunneled subcutaneously from the median implant pocket of the subcutaneous device 14 laterally and posterior toward the patient's back to a location opposite the heart such that the heart 16 is disposed between the subcutaneous device 14 and the distal electrode coil 24 and distal sensing electrode 26 of lead 18 . Lead 19 , carrying electrode 21 may be any known type of epicardial or myocardial electrode bearing lead known to the art. Electrode 21 is illustrated as located on the patient's left ventricle. [0026] It is understood that while the subcutaneous device 14 is shown positioned through loose connective tissue between the skin and muscle layer of the patient, the term “subcutaneous device” is intended to include a device that can be positioned in the patient to be implanted using any non-intravenous location of the patient, such as below the muscle layer or within the thoracic cavity, for example. [0027] Further referring to FIG. 1 , a programmer 20 is shown in telemetric communication with subcutaneous device 14 by an RF communication link 22 . Communication link 22 may be any appropriate RF link such as Bluetooth, WiFi, MICS, or as described in U.S. Pat. No. 5,683,432 “Adaptive Performance-Optimizing Communication System for Communicating with an Implantable Medical Device” to Goedeke, et al. and incorporated herein by reference in its entirety. [0028] Subcutaneous device 14 includes a housing 15 that may be constructed of stainless steel, titanium or ceramic as described in U.S. Pat. Nos. 4,180,078 “Lead Connector for a Body Implantable Stimulator” to Anderson and 5,470,345 “Implantable Medical Device with Multi-layered Ceramic Enclosure” to Hassler, et al, both incorporated herein by reference in their entireties. The electronics circuitry of SubQ ICD 14 may be incorporated on a polyimide flex circuit, printed circuit board (PCB) or ceramic substrate with integrated circuits packaged in leadless chip carriers and/or chip scale packaging (CSP). [0029] Optional subcutaneous lead 18 as illustrated includes a defibrillation coil electrode 24 , a distal sensing electrode 26 , an insulated flexible lead body and a proximal connector pin 27 (shown in FIG. 2 ) for connection to the housing 15 of the subcutaneous device 14 via a connector 25 . In addition, one or more electrodes 28 (shown in FIG. 2 ) are positioned along the outer surface of the housing to form a housing-based subcutaneous electrode array (SEA). Distal sensing electrode 26 is sized appropriately to match the sensing impedance of the housing-based subcutaneous electrode array. [0030] It is understood that while device 14 is shown with electrodes 28 positioned on housing 15 , according to an embodiment of the present disclosure electrodes 28 may be alternatively positioned along one or more separate leads connected to device 14 via connector 25 . Atrial sensing is accomplished via the subcutaneously located electrodes. Ventricular sensing may be accomplished using any of the electrodes, including the subcutaneous electrodes and/or electrodes located on or adjacent the heart as described below. [0031] Continuing with FIG. 2 , electrodes 28 are welded into place on the flattened periphery of the housing 15 . In the embodiment depicted in this figure, the complete periphery of the SubQ ICD may be manufactured to have a slightly flattened perspective with rounded edges to accommodate the placement of the electrodes 28 . The electrodes 28 are welded to housing 15 (to preserve hermaticity) and are connected via wires (not shown) to electronic circuitry (described herein below) inside housing 15 . Electrodes 28 may be constructed of flat plates, or alternatively, may be spiral electrodes as described in U.S. Pat. No. 6,512,940 “Subcutaneous Spiral Electrode for Sensing Electrical Signals of the Heart” to Brabec, et al. and mounted in a non-conductive surround shroud as described in U.S. Pat. Nos. 6,522,915 “Surround Shroud Connector and Electrode Housings for a Subcutaneous Electrode Array and Leadless ECGs” to Ceballos, et al. and 6,622,046 “Subcutaneous Sensing Feedthrough/Electrode Assembly” to Fraley, et al, all incorporated herein by reference in their entireties. The electrodes 28 of FIG. 2 can be positioned to form orthogonal or equilateral signal vectors, for example. [0032] The electronic circuitry employed in subcutaneous device 14 can take any of the known forms that detect a tachyarrhythmia from the sensed ECG and provide cardioversion/defibrillation shocks as well as post-shock pacing as needed while the heart recovers. A simplified block diagram of such circuitry adapted to function employing the first and second cardioversion-defibrillation electrodes as well as the ECG sensing and pacing electrodes described herein below is set forth in FIG. 3A . It will be understood that the simplified block diagram does not show all of the conventional components and circuitry of such devices including digital clocks and clock lines, low voltage power supply and supply lines for powering the circuits and providing pacing pulses or telemetry circuits for telemetry transmissions between the device 14 and external programmer 20 . [0033] FIG. 3A is an exemplary schematic diagram of electronic circuitry within a hermetically sealed housing of a subcutaneous device according to an embodiment of the present disclosure. As illustrated in FIG. 3A , subcutaneous device 14 includes a low voltage battery 153 coupled to a power supply (not shown) that supplies power to the circuitry of the subcutaneous device 14 and the pacing output capacitors to supply pacing energy in a manner well known in the art. The low voltage battery 153 may be formed of one or two conventional LiCF x , LiMnO 2 or Lil 2 cells, for example. The subcutaneous device 14 also includes a high voltage battery 112 that may be formed of one or two conventional LiSVO or LiMnO 2 cells. Although two both low voltage battery and a high voltage battery are shown in FIG. 3A , according to an embodiment of the present disclosure, the device 14 could utilize a single battery for both high and low voltage uses. [0034] Further referring to FIG. 3A , subcutaneous device 14 functions are controlled by means of software, firmware and hardware that cooperatively monitor the ECG, determine when a cardioversion-defibrillation shock or pacing is necessary, and deliver prescribed cardioversion-defibrillation and pacing therapies. The subcutaneous device 14 may incorporate circuitry set forth in commonly assigned U.S. Pat. Nos. 5,163,427 “Apparatus for Delivering Single and Multiple Cardioversion and Defibrillation Pulses” to Keimel and 5,188,105 “Apparatus and Method for Treating a Tachyarrhythmia” to Keimel for selectively delivering single phase, simultaneous biphasic and sequential biphasic cardioversion-defibrillation shocks typically employing ICD IPG housing electrodes 28 coupled to the COMMON output 123 of high voltage output circuit 140 and cardioversion-defibrillation electrode 24 disposed posteriorly and subcutaneously and coupled to the HVI output 113 of the high voltage output circuit 140 . Outputs 132 of FIG. 3A is coupled to sense electrode 26 . [0035] The cardioversion-defibrillation shock energy and capacitor charge voltages can be intermediate to those supplied by ICDs having at least one cardioversion-defibrillation electrode in contact with the heart and most AEDs having cardioversion-defibrillation electrodes in contact with the skin. The typical maximum voltage necessary for ICDs using most biphasic waveforms is approximately 750 Volts with an associated maximum energy of approximately 40 Joules. The typical maximum voltage necessary for AEDs is approximately 2000-5000 Volts with an associated maximum energy of approximately 200-360 Joules depending upon the model and waveform used. The subcutaneous device 14 of the present disclosure uses maximum voltages in the range of about 300 to approximately 1000 Volts and is associated with energies of approximately 25 to 150 joules or more. The total high voltage capacitance could range from about 50 to about 300 microfarads. Such cardioversion-defibrillation shocks are only delivered when a malignant tachyarrhythmia, e.g., ventricular fibrillation is detected through processing of the far field cardiac ECG employing the detection algorithms as described herein below. [0036] In FIG. 3A , sense amp 190 in conjunction with pacer/device timing circuit 178 processes the far field ECG sense signal that is developed across a particular ECG sense vector defined by a selected pair of the subcutaneous electrodes 24 , 26 and 28 , or, optionally, a virtual signal (i.e., a mathematical combination of two vectors) if selected. In some embodiments, sensing of ventricular depolarizations can be accomplished using an electrode 21 , located on or adjacent the outer wall of the ventricle being paced. The selection of the sensing electrode pair is made through the switch matrix/MUX 191 in a manner to provide the most reliable sensing of the ECG signals of interest, which, in the present invention includes both R-waves (ventricular depolarizations) and P-waves (atrial depolarizations). The sense amp 190 thus serves as means for sensing both atrial and ventricular depolarizations. [0037] The far field ECG signals are passed through the switch matrix/MUX 191 to and sense amplifier 190 to the pacer/device timing circuit 178 , which, in conjunction with the control circuit 144 evaluates the sensed ECG signals. Bradycardia, or asystole, is typically determined by an escape interval timer within the pacer timing circuit 178 and/or the control circuit 144 . Pacer/device timing circuitry 178 , in conjunction with control circuitry provide means for analysis of detected atrial and ventricular depolarization waveforms and timing, for selecting the mode of therapy provided by the device and for determining the timing intervals involved in the delivery of pacing therapies. [0038] Pace Trigger signals from pacer device/timing circuitry 178 , under control of the control circuitry 144 , are applied to the pacing pulse generator 192 . Ventricular pacing stimulation pulses are delivered via switch matrix 191 to electrode 21 , with any of the other electrodes serving as an indifferent electrode. Fusion-pacing therapy according to the disclosure is delivered via this circuitry. The pulse generator circuitry thus serves as a means for the delivery of the desired pacing therapy according to the invention. Bradycardia pacing when the interval between successive R-waves exceeds the escape interval may be provided both as part of the fusion pacing therapy according to the present invention and to maintain cardiac output after delivery of a cardioversion-defibrillation shock that may cause the heart to slowly beat as it recovers back to normal function. Sensing subcutaneous far field signals in the presence of noise may be aided by the use of appropriate denial and extensible accommodation periods as described in U.S. Pat. No. 6,236,882 “Noise Rejection for Monitoring ECGs” to Lee, et al. and incorporated herein by reference in its entirety. [0039] Detection of a malignant tachyarrhythmia is determined in the Control circuit 144 as a function of the intervals between R-wave sense event signals that are output from the pacer/device timing 178 and sense amplifier circuit 190 to the timing and control circuit 144 . and thence to the microprocessor 142 . It should be noted that the present disclosure utilizes not only interval based signal analysis method but also supplemental sensors and morphology processing method and apparatus as described herein below. Analysis of morphologies of detected depolarizations for purposes of the present invention may take place in the microprocessor circuitry 142 . The microprocessor circuitry comprises a means for morphology analysis, for determination of reliability of atrial sensing and detection of reverse remodeling as discussed below. In conjunction with the control circuitry 144 It also serves as a means for controlling the various switching operations between pacing therapies, for measuring time interval and for controlling the duration of the delay between detected atrial depolarizations and delivery of ventricular pacing pulses as described below. [0040] Control circuitry 144 may take the form of a microprocessor controlled circuit as illustrated operating under a stored instruction set which defines the various operations associated with delivery of pacing therapies according to the present invention. Alternatively, fixed purpose analog or digital circuitry incorporated within the control and/or timing circuitry may perform some or all of these operations. The form of circuitry chosen is not critical to the invention so long as it is capable of performing the required operations (method steps) associated with the invention. Correspondingly, the specific division of functions between the microprocessor circuitry 142 , the control circuitry 144 and the timing circuitry 178 is not critical to the invention, so long as the circuitry as a whole is capable of performing the required operations (method steps) associated with the invention [0041] Supplemental sensors such as tissue color, tissue oxygenation, respiration, patient activity and the like may be used to contribute to the decision to apply or withhold a defibrillation therapy as described generally in U.S. Pat. No. 5,464,434 “Medical Interventional Device Responsive to Sudden Hemodynamic Change” to Alt and incorporated herein by reference in its entirety. Sensor processing block 194 provides sensor data to microprocessor 142 via data bus 146 . Specifically, patient activity and/or posture may be determined by the apparatus and method as described in U.S. Pat. No. 5,593,431 “Medical Service Employing Multiple DC Accelerometers for Patient Activity and Posture Sensing and Method” to Sheldon and incorporated herein by reference in its entirety. Patient respiration may be determined by the apparatus and method as described in U.S. Pat. No. 4,567,892 “Implantable Cardiac Pacemaker” to Plicchi, et al. and incorporated herein by reference in its entirety. Patient tissue oxygenation or tissue color may be determined by the sensor apparatus and method as described in U.S. Pat. No. 5,176,137 to Erickson, et al. and incorporated herein by reference in its entirety. The oxygen sensor of the '137 patent may be located in the subcutaneous device pocket or, alternatively, located on the lead 18 to enable the sensing of contacting or near-contacting tissue oxygenation or color. [0042] Certain steps in the performance of the detection algorithm criteria are cooperatively performed in microcomputer 142 , including microprocessor, RAM and ROM, associated circuitry, and stored detection criteria that may be programmed into RAM via a telemetry interface (not shown) conventional in the art. Data and commands are exchanged between microcomputer 142 and timing and control circuit 144 , pacer timing/amplifier circuit 178 , and high voltage output circuit 140 via a bi-directional data/control bus 146 . The pacer timing/amplifier circuit 178 and the control circuit 144 are clocked at a slow clock rate. The microcomputer 142 is normally asleep, but is awakened and operated by a fast clock by interrupts developed by each R-wave sense event, on receipt of a downlink telemetry programming instruction or upon delivery of cardiac pacing pulses to perform any necessary mathematical calculations, to perform tachycardia and fibrillation detection procedures, and to update the time intervals monitored and controlled by the timers in pacer/device timing circuitry 178 . [0043] When a malignant tachycardia is detected, high voltage capacitors 156 , 158 , 160 , and 162 are charged to a pre-programmed voltage level by a high-voltage charging circuit 164 . It is generally considered inefficient to maintain a constant charge on the high voltage output capacitors 156 , 158 , 160 , 162 . Instead, charging is initiated when control circuit 144 issues a high voltage charge command HVCHG delivered on line 145 to high voltage charge circuit 164 and charging is controlled by means of bi-directional control/data bus 166 and a feedback signal VCAP from the HV output circuit 140 . High voltage output capacitors 156 , 158 , 160 and 162 may be of film, aluminum electrolytic or wet tantalum construction. [0044] The negative terminal of high voltage battery 112 is directly coupled to system ground. Switch circuit 114 is normally open so that the positive terminal of high voltage battery 112 is disconnected from the positive power input of the high voltage charge circuit 164 . The high voltage charge command HVCHG is also conducted via conductor 149 to the control input of switch circuit 114 , and switch circuit 114 closes in response to connect positive high voltage battery voltage EXT B+ to the positive power input of high voltage charge circuit 164 . Switch circuit 114 may be, for example, a field effect transistor (FET) with its source-to-drain path interrupting the EXT B+ conductor 118 and its gate receiving the HVCHG signal on conductor 145 . High voltage charge circuit 164 is thereby rendered ready to begin charging the high voltage output capacitors 156 , 158 , 160 , and 162 with charging current from high voltage battery 112 . [0045] High voltage output capacitors 156 , 158 , 160 , and 162 may be charged to very high voltages, e.g., 300-1000V, to be discharged through the body and heart between the electrode pair of subcutaneous cardioversion-defibrillation electrodes 113 and 123 . The details of the voltage charging circuitry are also not deemed to be critical with regard to practicing the present disclosure; one high voltage charging circuit believed to be suitable for the purposes of the present disclosure is disclosed. High voltage capacitors 156 , 158 , 160 and 162 may be charged, for example, by high voltage charge circuit 164 and a high frequency, high-voltage transformer 168 as described in detail in commonly assigned U.S. Pat. No. 4,548,209 “Energy Converter for Implantable Cardioverter” to Wielders, et al. Proper charging polarities are maintained by diodes 170 , 172 , 174 and 176 interconnecting the output windings of high-voltage transformer 168 and the capacitors 156 , 158 , 160 , and 162 . As noted above, the state of capacitor charge is monitored by circuitry within the high voltage output circuit 140 that provides a VCAP, feedback signal indicative of the voltage to the timing and control circuit 144 . Timing and control circuit 144 terminates the high voltage charge command HVCHG when the VCAP signal matches the programmed capacitor output voltage, i.e., the cardioversion-defibrillation peak shock voltage. [0046] Control circuit 144 then develops first and second control signals NPULSE 1 and NPULSE 2 , respectively, that are applied to the high voltage output circuit 140 for triggering the delivery of cardioverting or defibrillating shocks. In particular, the NPULSE 1 signal triggers discharge of the first capacitor bank, comprising capacitors 156 and 158 . The NPULSE 2 signal triggers discharge of the first capacitor bank and a second capacitor bank, comprising capacitors 160 and 162 . It is possible to select between a plurality of output pulse regimes simply by modifying the number and time order of assertion of the NPULSE 1 and NPULSE 2 signals. The NPULSE 1 signals and NPULSE 2 signals may be provided sequentially, simultaneously or individually. In this way, control circuitry 144 serves to control operation of the high voltage output stage 140 , which delivers high energy cardioversion-defibrillation shocks between the pair of the cardioversion-defibrillation electrodes 113 and 123 coupled to the HV- 1 and COMMON output as shown in FIG. 3A . [0047] Thus, subcutaneous device 14 monitors the patient's cardiac status and initiates the delivery of a cardioversion-defibrillation shock through the cardioversion-defibrillation electrodes 24 and 28 in response to detection of a tachyarrhythmia requiring cardioversion-defibrillation. The high HVCHG signal causes the high voltage battery 112 to be connected through the switch circuit 114 with the high voltage charge circuit 164 and the charging of output capacitors 156 , 158 , 160 , and 162 to commence. Charging continues until the programmed charge voltage is reflected by the VCAP signal, at which point control and timing circuit 144 sets the HVCHG signal low terminating charging and opening switch circuit 114 . Typically, the charging cycle takes only fifteen to twenty seconds, and occurs very infrequently. The subcutaneous device 14 can be programmed to attempt to deliver cardioversion shocks to the heart in the manners described above in timed synchrony with a detected R-wave or can be programmed or fabricated to deliver defibrillation shocks to the heart in the manners described above without attempting to synchronize the delivery to a detected R-wave. Episode data related to the detection of the tachyarrhythmia and delivery of the cardioversion-defibrillation shock can be stored in RAM for uplink telemetry transmission to an external programmer as is well known in the art to facilitate in diagnosis of the patient's cardiac state. A patient receiving the device 14 on a prophylactic basis would be instructed to report each such episode to the attending physician for further evaluation of the patient's condition and assessment for the need for implantation of a more sophisticated ICD. [0048] Turning to FIG. 3B , the subcutaneous ECG signal (ECG 1 ) is applied to ECG morphology block 232 , filtered by a 2-pole 23 Hz low pass filter 252 and evaluated by DSP microcontroller 254 under control of program instructions stored in System Instruction RAM 258 . ECG morphology is used for subsequent rhythm detection/determination (to be described herein below). [0049] Subcutaneous device 14 desirably includes telemetry circuit (not shown in FIG. 3A ), so that it is capable of being programmed by means of external programmer 20 via a 2-way telemetry link 22 (shown in FIG. 1 ). Uplink telemetry allows device status and diagnostic/event data to be sent to external programmer 20 for review by the patient's physician. Downlink telemetry allows the external programmer via physician control to allow the programming of device function and the optimization of the detection and therapy for a specific patient. Programmers and telemetry systems suitable for use in the practice of the present disclosure have been well known for many years. Known programmers typically communicate with an implanted device via a bidirectional radio-frequency telemetry link, so that the programmer can transmit control commands and operational parameter values to be received by the implanted device, so that the implanted device can communicate diagnostic and operational data to the programmer. Programmers believed to be suitable for the purposes of practicing the present disclosure include the Models 9790 and CareLink® programmers, commercially available from Medtronic, Inc., Minneapolis, Minn. [0050] Various telemetry systems for providing the necessary communications channels between an external programming unit and an implanted device have been developed and are well known in the art. Telemetry systems believed to be suitable for the purposes of practicing the present disclosure are disclosed, for example, in the following U.S. patents: U.S. Pat. No. 5,127,404 to Wyborny et al. entitled “Telemetry Format for Implanted Medical Device”; U.S. Pat. No. 4,374,382 to Markowitz entitled “Marker Channel Telemetry System for a Medical Device”; and U.S. Pat. No. 4,556, 063 to Thompson et al. entitled “Telemetry System for a Medical Device”. The Wyborny et al. '404, Markowitz '382, and Thompson et al. '063 patents are commonly assigned to the assignee of the present disclosure, and are each hereby incorporated by reference herein in their respective entireties. [0051] FIG. 3B is a schematic diagram of signal processing aspects of a subcutaneous device according to an exemplary embodiment of the present disclosure. The transthoracic ECG signal (ECG 1 ) detected between the distal electrode 26 of subcutaneous lead 18 and one of electrodes 28 positioned on the subcutaneous device 14 are amplified and band pass filtered (2.5-105 Hz) by pre-amplifiers 202 and 206 located in Sense Amp 190 of FIG. 3A . The amplified EGM signals are directed to A/D converters 210 and 212 , which operate to sample the time varying analog EGM signal and digitize the sampled points. The digital output of A/D converters 210 and 212 are applied to temporary buffers/control logic, which shifts the digital data through its stages in a FIFO manner under the control of Pacer/Device Timing block 178 of FIG. 3A . Virtual Vector block 226 selects one housing-based ECG signal (ECG 2 ) from any pair of electrodes 28 as described, for example, in U.S. Pat. No. 5,331,966 “Subcutaneous Multi-Electrode Sensing System, Method and Pacer” to Bennett, et al. or, alternatively, generates a virtual vector signal under control of Microprocessor 142 and Control block 144 as described in U.S. Pat. No. 6,505,067 “System and Method for Deriving Virtual ECG or EGM Signal” to Lee, et al; both patents incorporated herein by reference in their entireties. ECG 1 and ECG 2 vector selection may be selected by the patient's physician and programmed via telemetry link 22 from programmer 20 . [0052] According to an embodiment of the present disclosure, in order to automatically select the preferred ECG vector set, it is necessary to have an index of merit upon which to rate the quality of the signal. “Quality” is defined as the signal's ability to provide accurate heart rate estimation and accurate morphological waveform separation between the patient's usual sinus rhythm and the patient's ventricular tachyarrhythmia. [0053] Appropriate indices may include P-wave amplitude, R-wave amplitude, R-wave peak amplitude to waveform amplitude between R-waves (i.e., signal to noise ratio), low slope content, relative high versus low frequency power, mean frequency estimation, probability density function, or some combination of these metrics. [0054] Automatic vector selection can be done at implantation or periodically (daily, weekly, monthly) or both. At implant, automatic vector selection may be initiated as part of an automatic device turn-on procedure that performs such activities as measure lead impedances and battery voltages. The device turn-on procedure may be initiated by the implanting physician (e.g., by pressing a programmer button) or, alternatively, may be initiated automatically upon automatic detection of device/lead implantation. The turn-on procedure may also use the automatic vector selection criteria to determine if ECG vector quality is adequate for the current patient and for the device and lead position, prior to suturing the subcutaneous device 14 device in place and closing the incision. Such an ECG quality indicator would allow the implanting physician to maneuver the device to a new location or orientation to improve the quality of the ECG signals as required. The preferred ECG vector or vectors may also be selected at implant as part of the device turn-on procedure. The preferred vectors might be those vectors with the indices that maximize rate estimation and detection accuracy. There may also be an a priori set of vectors that are preferred by the physician, and as long as those vectors exceed some minimum threshold, or are only slightly worse than some other more desirable vectors, the a priori preferred vectors are chosen. Certain vectors may be considered nearly identical such that they are not tested unless the a priori selected vector index falls below some predetermined threshold. [0055] Depending upon metric power consumption and power requirements of the device, the ECG signal quality metric may be measured on the range of vectors (or alternatively, a subset) as often as desired. Data may be gathered, for example, on a minute, hourly, daily, weekly or monthly basis. More frequent measurements (e.g., every minute) may be averaged over time and used to select vectors based upon susceptibility of vectors to occasional noise, motion noise, or EMI, for example. [0056] Alternatively, the subcutaneous device 14 may have an indicator/sensor of patient activity (piezo-resistive, accelerometer, impedance, or the like) and delay automatic vector measurement during periods of moderate or high patient activity to periods of minimal to no activity. One representative scenario may include testing/evaluating ECG vectors once daily or weekly while the patient has been determined to be asleep (using an internal clock (e.g., 2:00 am) or, alternatively, infer sleep by determining the patient's position (via a 2- or 3-axis accelerometer) and a lack of activity). [0057] If infrequent automatic, periodic measurements are made, it may also be desirable to measure noise (e.g., muscle, motion, EMI, etc.) in the signal and postpone the vector selection measurement when the noise has subsided. [0058] Subcutaneous device 14 may optionally have an indicator of the patient's posture (via a 2- or 3-axis accelerometer). This sensor may be used to ensure that the differences in ECG quality are not simply a result of changing posture/position. The sensor may be used to gather data in a number of postures so that ECG quality may be averaged over these postures or, alternatively, selected for a preferred posture. [0059] In the preferred embodiment, vector quality metric calculations would occur a number of times over approximately 1 minute, once per day, for each vector. These values would be averaged for each vector over the course of one week. Averaging may consist of a moving average or recursive average depending on time weighting and memory considerations. In this example, the preferred vector(s) would be selected once per week. [0060] Continuing with FIG. 3B , a diagnostic channel 228 receives a programmable selected ECG signal from the housing based subcutaneous electrodes and the transthoracic ECG from the distal electrode 26 on lead 18 . Block 238 compresses the digital data, the data is applied to temporary buffers/control logic 218 which shifts the digital data through its stages in a FIFO manner under the control of Pacer/Device Timing block 178 of FIG. 3A , and the data is then stored in SRAM block 244 via direct memory access block 242 . [0061] The two selected ECG signals (ECG 1 and ECG 2 ) are additionally used to provide R-wave interval sensing via ECG sensing block 230 . IIR notch filter block 246 provides 50/60 Hz notch filtering. A rectifier and auto-threshold block 248 provides R-wave event detection as described in U.S. Pat. No. 5,117,824 “Apparatus for Monitoring Electrical Physiologic Signals” to Keimel, et al; publication WO2004023995 “Method and Apparatus for Cardiac R-wave Sensing in a Subcutaneous ECG Waveform” to Cao, et al. and U.S. Publication No. 2004/0260350 “Automatic EGM Amplitude Measurements During Tachyarrhythmia Episodes” to Brandstetter, et al, all incorporated herein by reference in their entireties. The rectifier of block 248 performs full wave rectification on the amplified, narrowband signal from band pass filter 246 . A programmable fixed threshold (percentage of peak value), a moving average or, more preferably, an auto-adjusting threshold is generated as described in the '824 patent or '350 publication. In these references, following a detected depolarization, the amplifier is automatically adjusted so that the effective sensing threshold is set to be equal to a predetermined portion of the amplitude of the sensed depolarization, and the effective sensing threshold decays thereafter to a lower or base-sensing threshold. A comparator in block 248 determines signal crossings from the rectified waveform and auto-adjusting threshold signal. A timer block 250 provides R-wave to R-wave interval timing for subsequent arrhythmia detection (to be described herein below). The heart rate estimation is derived from the last 12 R-R intervals (e.g., by a mean, trimmed mean, or median; for example); with the oldest data value being removed as a new data value is added. [0062] FIG. 3C depicts a typical subcutaneous ECG waveform 402 and waveform 404 depicts the same waveform after filtering and rectification. A time dependant threshold 406 allows a more sensitive sensing threshold temporally with respect to the previous sensed R-wave. Sensed events 408 indicate when the rectified and filtered ECG signal 404 exceeds the auto-adjusting threshold and a sensed event has occurred. [0063] Some of the operating modes of the device circuitry of FIG. 3A are depicted in the flow charts ( FIGS. 4-5 ) and described as follows. The particular operating mode is a programmed or hard-wired sub-set of the possible operating modes as also described below. For convenience, the algorithm of FIGS. 4-5 is described in the context of determining the PEI delay and computing A-VP intervals to optimally pace the LV chamber to produce electromechanical fusion with the corresponding intrinsic depolarization of the RV chamber. The RV chamber depolarizes intrinsically so that the pre-excited electromechanical fusion occurs as between the intrinsically activated RV chamber and the pre-excitation evoked response of the LV chamber. As noted below, the algorithm can be employed to determine an optimal PEI delay that results in an A-VP interval producing ventricular synchrony (i.e., CRT delivery via a single ventricular pacing stimulus). Of course, the methods according to the present disclosure are intended to be stored as executable instructions on any appropriate computer readable medium although they may be manually or performed by dedicated purpose analog and/or digital electronic circuitry as well. [0064] FIG. 4 illustrates one embodiment of the present disclosure wherein the IPG circuit 300 includes a method 400 beginning with step 402 that is periodically performed to determine the intrinsic ventricular delay. In conjunction with step 402 the first-to-depolarize ventricle is understood to be the RV and the second-to-depolarize ventricle is understood to be the LV. In step 402 , the device measures an A-V interval extending between an atrial depolarization sensed via the chosen pair of far-field sensing electrodes ( 26 , 28 , FIGS. 2 , 3 ) and the following sensed ventricular depolarization. As discussed in conjunction with FIG. 3C , the ventricular depolarization is sensed when the amplitude of the filtered electrogram exceeds the detection threshold. The sensed A-V interval (AVI) is stored. [0065] In step 404 , AVI is decremented by the PEI to generate the A-VP delay for delivering pacing stimulus to the LV chamber. The magnitude of the PEI depends on several factors, including internal circuitry processing delay, location of sensing electrodes, location of pacing electrodes, heart rate, dynamic physiologic conduction status (e.g., due to ischemia, myocardial infarction, LBBB or RBBB, etc.). The inventors have found that a PEI of approximately 20-40 milliseconds (ms) oftentimes provides adequate pre-excitation to the LV chamber resulting in electromechanical fusion of both ventricles. However, a reasonable range for the PEI runs from about one ms to about 100 ms (or more). [0066] The PEI may be fixed or variable dependent upon the sensed AVI duration, sensed heart rate (HR), a derived value combining HR with an activity sensor input, P-wave to P-wave timing, R-wave to R-wave timing and the like. PEI values may be calculated as a mathematical function of the various measured values or may be selected from a look-up table correlating desired PEI values to measured values. [0067] Optionally, an iterative subroutine for adjusting the PEI can be used and/or a clinical procedure utilized to help define optimum values for the magnitude of the decrease in the A-VP delay. The values of PEI may be optimized, for example, based upon the waveforms of the sensed ventricular depolarizations following delivery of the pacing pulses. For example, a mechanism for varying timing of ventricular pacing pulses to minimize R-wave width as described in U.S. Pat. No. 6,804,555, issued to Warkentin and incorporated by reference in its entirety may be employed before implant to initialize the value of PEI or automatically by the device after implant to update the value of PEI as the patient's condition changes over time, as discussed in more detail below. A look-up table relating stored optimal PEI values to corresponding AVI values may thereafter be used to select the value of PEI corresponding to a sensed AVI value at step 404 . [0068] Following the decrementing step 404 the A-VP (pacing) delay interval is set and in step 406 pre-excitation pacing therapy is delivered to the LV chamber upon expiration of the A-VP interval for a defined series of cardiac cycles or for a defined time period. In the context of the atrial-synchronized ventricular fusion pacing mode described, it should also be understood that the device may also pace in the ventricle in response to the expiration of an underlying ventricular escape interval and/or in response to sensed ventricular depolarizations not preceded by associated sensed atrial depolarizations. [0069] In the presently illustrated embodiment of the disclosure, pre-excitation pacing therapy delivery using the derived A-VP delay and PEI values continues until at step 408 : (i) a pre-set number of cardiac cycles occur, (ii) a pre-set time period expires, (iii) a loss of capture occurs in the LV chamber, or another physiologic response trigger event occurs. The number of cardiac cycles or period for events (i) and (ii) may be set to any clinically appropriate value, given the patient's physiologic condition, for example Alternative indicators that the delivered fusion pacing therapy is ineffective may be used as a physiologic event response trigger. Physiological response event triggers might, for example, include excessively wide R-waves associated with delivered pacing pulses, indications if inadequate cardiac performance from an associated subcutaneous or other type of hemodynamic sensor or just the expiration of a time interval or a given number of pacing pulses greater than those associated with events (i) or (ii), respectively. If a loss of capture in the LV chamber is detected it could indicate that the ventricular pacing stimulus is being delivered too late (e.g., during the refractory period of the LV chamber) or that the LV pacing electrodes have malfunctioned or become dislodged. The pre-excitation pacing therapy could alternatively be terminated as a response to a loss of capture, under the assumption that the electrodes have become dislodged. [0070] With respect to the physiologic response trigger step 410 an iterative process for determining appropriate PEIs may be performed. Instep 410 , the current PEIs and derived A-VP delays are directly manipulated from prior operating values while one or more physiologic responses, for example R-wave widths as discussed above, are monitored and/or measured and stored. PEI values may be varied associated with various measured AVIs to derive a look up table associating the most desirable PEIs for each AVI. Such a look up table, as periodically updated, may be used at step 404 to decrement the measured AVIs to derive A-VP delays. After storing the physiologic response data (and corresponding PEIs used during data collection) at step 412 the data is compared and the PEI corresponding to the most favorable physiologic response at the current AVI is then programmed as the operating PEI. The process then proceeds back to step 406 and the LV chamber receives pre-excitation pacing therapy based on the updated, physiologically-derived PEI. [0071] In FIG. 5 , a process 600 for periodically ceasing delivery of the pre-excitation, atrial-synchronized single ventricular pacing therapy to switch to an alternative pacing therapy, or to allow normal sinus rhythm to continue chronically is illustrated. The process 600 can be implemented as a part of steps 402 or 410 - 412 ( FIG. 4 ) or can be performed independently. In either case, process 600 is designed to help reveal improvement (or decline) of a patient's condition. In the former case, if so-called “reverse remodeling” of the myocardium occurs resulting in return of ventricular synchrony and improved hemodynamics and autonomic tone, pre-excitation therapy delivery may be temporarily or permanently terminated. The patient may, in the best scenario, be relieved of pacing therapy delivery altogether (programming the pacing circuitry to an ODO monitoring-only “pacing modality”). Assuming the patient is not chronotropically incompetent, normal sinus rhythm may emerge permanently for all the activities of daily living. Additionally, the process 600 may be employed to search for a change in conduction status, e.g., shortening if inter-ventricular conduction delay times. In conjunction with this process, pre-excitation pacing therapy ceases for one or more cardiac cycles and the intrinsic, normal sinus rhythm is allowed to emerge. At step 604 the morphology (e.g. width) of the intrinsic ventricular depolarization(s) is monitored and stored in memory. At step 606 an analysis of ventricular depolarization waveforms (R-waves) depolarization comparison is performed, for example by comparing the morphologies (e.g. widths) of the detected depolarization morphologies with a reference value indicative of normal ventricular synchrony. The reference value may be pre-programmed or, for example, may correspond to a best obtained result employing the pre-excitation therapy of the present invention. In the event that the intrinsic ventricular depolarization morphology indicates that return of ventricular synchrony has occurred at step 608 , normal sinus rhythm is allowed to continue or a non-pre-excitation pacing therapy is initiated at step 610 . Otherwise, pre-excitation pacing therapy according to the present invention may be resumed at step 612 . [0072] The process of FIG. 6 may be employed to switch from and atrial-synchronized pre-excitation ventricular pacing therapy to a non-atrial synchronized triggered ventricular pacing therapy responsive to loss of accurate atrial sensing. The process 700 can be implemented as a part of steps 402 or 410 - 412 ( FIG. 4 ) or can be performed independently. In this aspect of the invention, the device periodically checks at step 702 to determine if a reliable pattern of atrial sensing has is ongoing. The device may, for example, evaluate the regularity of atrial sensing (regularity of the timing of sensed P-waves) and/or the frequency with which ventricular pacing pulses are generated or ventricular depolarizations (R-waves) are sensed absent prior associated atrial sensed depolarizations (P-waves). If atrial sensing is determined to be reliable at step 704 , the device simply continues pacing using the atrial-synchronized pacing modality discussed above at 706 . If not, the device may switch to a non-atrial-synchronized mode at 606 . For example, the device may thereafter act as a triggered ventricular pacemaker (known to the art as the VVT pacing mode), stimulating the ventricle in response to either a sensed ventricular depolarization or expiration of an underlying ventricular pacing interval. [0073] FIG. 6 illustrates an alternative embodiment of the present invention employing a subcutaneous electrode array as described in US Patent Application No. US 2006/0122649, by Ghanem, et al, as discussed above. Numbered elements correspond to identically numbered elements in FIG. 1 , with the exception that a subcutaneous electrode array 721 , located on subcutaneous lead 719 is substituted for electrode 21 on lead 19 of FIG. 1 . Electrodes on array 721 are selected to steer stimulation energy to the left ventricle, using the techniques described in the Ghanem, et al application. The electrode array could alternately be located on the enclosure 15 of the device 14 . In this embodiment, some or all of the same electrodes may be used for both pacing and sensing. Location of the electrode array in an infra-clavicular position may be desirable to reduce stimulation thresholds. [0074] FIG. 7 illustrates an additional alternative embodiment of the present invention employing a leadless stimulation electrode array as described in U.S. Pat. No. 5,814,089, issued to Stokes, et al., as discussed above. Numbered elements correspond to identically numbered elements in FIG. 1 , with the exception that a leadless electrode-bearing device 821 , located on the left ventricle, is substituted for electrode 21 on lead 19 of FIG. 1 . Electrodes on array 821 deliver stimulation energy to the left ventricle, using the techniques described in the Stokes, et al. patent. Stimulation is triggered by the device 14 , using an RF or other communication link 819 . Energy to power the pulse generation circuitry within the leadless electrode device 821 may also be transmitted using link 819 or by other mechanisms, also as disclosed in the Stokes, et al. patent. [0075] It should be understood that, certain of the above-described structures, functions and operations of the pacing systems of the illustrated embodiments are not necessary to practice the present disclosure and are included in the description simply for completeness of an exemplary embodiment or embodiments. It will also be understood that there may be other structures, functions and operations ancillary to the typical operation of an implantable pulse generator that are not disclosed and are not necessary to the practice of the present disclosure.

According to this disclosure, a non-transvenous pacing and, optionally defibrillation, therapy device is implanted subcutaneously and oriented to provide cardiac sensing from electrodes spaced from a heart and deliver pacing and/or defibrillation from one or more non-transvenous electrodes (e.g., an epicardial or pericardial electrode or electrode patch). A subject receiving a device according to this disclosure is monitored to confirm a relatively stable bundle branch block (i.e., delayed activation) of one ventricle. The subcutaneous device has electrodes disposed on the housing and/or having an electrode on a subcutaneous medical lead is oriented so that the pacing (and sensing) vector impinges mainly upon the one ventricle, and/or optionally an epicardial or pericardial lead is deployed to a last-to-depolarize ventricle (e.g., a left ventricle) so that single-ventricular pacing is delivered to achieve fusion depolarization of both ventricles.

The present application claims priority from Japanese applications JP 2007-211791 filed on Aug. 15, 2007, the content of which is hereby incorporated by reference into this application. BACKGROUND OF THE INVENTION The present invention relates to a display device, and more particularly to a display device which includes thin film transistors (TFT) made of poly-silicon (poly-crystalline silicon). As a kind of liquid crystal display device, conventionally, there has been known an active-matrix-type liquid crystal display device which includes an active element for every pixel, and operates the active element by switching. As a kind of the active-matrix-type liquid crystal display device, there has been known a TFT-method active-matrix-type liquid crystal display module which uses a thin film transistor having a semiconductor layer made of poly-silicon (hereinafter, also referred to as a poly-silicon thin film transistor) as an active element. In a liquid crystal display panel of the liquid crystal display module which uses the poly-silicon thin film transistor as the active element (hereinafter, referred to as a Poly-SiTr-TFT liquid crystal display module), the poly-silicon thin film transistors are arranged and formed on a quartz or a glass substrate in a matrix array. Further, an operation speed of the poly-silicon thin film transistor is higher than an operation speed of a thin film transistor having a semiconductor layer made of amorphous silicon. Accordingly, in the liquid crystal display panel of the Poly-SiTr-TFT liquid crystal display module, it is possible to form a peripheral circuit on the same substrate. SUMMARY OF THE INVENTION The above-mentioned poly-silicon thin film transistor is formed on the glass substrate using a low-temperature poly-silicon technique or the like. However, with respect to the poly-silicon thin film transistor formed on the glass substrate which has low heat radiation property, during an ON-operation time of the transistor, due to a high gate voltage of 10V or more and a high drain voltage of 10V or more applied to the transistor, a drain current on the order of 500 μA or more flows in the transistor and hence, a temperature of the transistor is elevated to 100° C. or more. Accordingly, there has been a drawback that the characteristic of the poly-silicon thin film transistor is fluctuated attributed to such self-heating thus deteriorating the reliability of a product. The present invention has been made to overcome the above-mentioned drawback of the related art, and it is an object of the present invention to provide a technique on a display device which can prevent the fluctuation of characteristic of a thin film transistor having a semiconductor layer made of poly-silicon formed on a substrate having low heat radiation property attributed to self-heating of the transistor. The above-mentioned and other objects and novel features of the present invention will become apparent from the description of this specification and attached drawings. To briefly explain typical invention among inventions disclosed in this application, they are as follows. The present invention is directed to a display device including a display panel which forms a plurality of sub pixels on a substrate thereof, and a drive circuit which is configured to drive the plurality of sub pixels, the drive circuit having a thin film transistor formed on the substrate (for example, glass substrate with low heat radiation property), and the thin film transistor having a semiconductor layer made of poly-silicon, wherein the thin film transistor includes a source electrode, a semiconductor layer and a drain electrode which are formed on the substrate, a gate insulation film which is formed on the source electrode, the semiconductor layer and the drain electrode, a gate electrode which is formed on the gate insulation film and above the semiconductor layer, an insulation film which is formed on the gate electrode, and a metal layer which is formed on the insulation film in a state that the metal layer covers at least a portion of the gate electrode. Due to such a constitution, in the present invention, by radiating heat which is generated when the thin film transistor is in an ON-operation state by way of the metal layer, it is possible to suppress the fluctuation of characteristic of the transistor. To briefly explain advantageous effects obtained by the typical invention among inventions disclosed in this application, they are as follows. According to a display device of the present invention, with respect to the thin film transistor which is formed on the substrate having low heat radiation property and has the semiconductor layer made of poly-silicon, it is possible to prevent the fluctuation of characteristic of the thin film transistor attributed to self-heating of the thin film transistor. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing an equivalent circuit of a liquid crystal display panel of a liquid crystal display module of an embodiment according to the present invention; FIG. 2 is a plan view showing the electrode structure of a poly-silicon thin film transistor which uses a semiconductor layer made of poly-silicon in a peripheral circuit of the embodiment according to the present invention; FIG. 3 is a cross-sectional view showing the cross-sectional structure taken along a line A-A′ in FIG. 2 ; FIG. 4 is a cross-sectional view showing another example of the cross-sectional structure taken along a line A-A′ in FIG. 2 ; FIG. 5 is a plan view showing another example of the electrode structure of a poly-silicon thin film transistor which uses a semiconductor layer made of poly-silicon in a peripheral circuit of the embodiment according to the present invention; FIG. 6 is a cross-sectional view showing the cross-sectional structure taken along a line A-A′ in FIG. 5 ; FIG. 7 is a cross-sectional view showing another example of the cross-sectional structure taken along a line A-A′ in FIG. 5 ; FIG. 8 is a plan view showing another example of the electrode structure of a poly-silicon thin film transistor which uses a semiconductor layer made of poly-silicon in a peripheral circuit of the embodiment according to the present invention; FIG. 9 is a cross-sectional view showing the cross-sectional structure taken along a line A-A′ in FIG. 8 ; FIG. 10 is a plan view showing another example of the electrode structure of a poly-silicon thin film transistor which uses a semiconductor layer made of poly-silicon in a peripheral circuit of the embodiment according to the present invention; FIG. 11 is a cross-sectional view showing the cross-sectional structure taken along a line A-A′ in FIG. 10 ; and FIG. 12 is a plan view showing another example of the electrode structure of a poly-silicon thin film transistor which uses a semiconductor layer made of poly-silicon in a peripheral circuit of the embodiment according to the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention is explained in detail in conjunction with drawings. Here, in all drawings for explaining the embodiment, parts having identical functions are given same numerals and their repeated explanation is omitted. FIG. 1 is a view showing an equivalent circuit of a liquid crystal display panel of a liquid crystal display module of the embodiment according to the present invention. In FIG. 1 , numeral 100 indicates a display part, numeral 110 indicates a horizontal shift register circuit (also referred to as a video line shift register circuit), and numeral 120 indicates a vertical shift register circuit (also referred to as a scanning line shift register circuit). The display part 100 includes sub pixels arranged in a matrix array, and each sub pixel is arranged in an intersecting region (a region surrounded by four signal lines) between two neighboring scanning lines (gate signal lines or horizontal signal lines) (G 0 to Gm) and two neighboring video lines (drain signal lines or vertical signal lines) (D 1 to Dn). Each sub pixel includes a pixel transistor (TFT), and the pixel transistor (TFT) is formed of a thin film transistor having a semiconductor layer made of poly-silicon. Drain electrodes of the pixel transistors (TFT) in each column of the respective sub pixels arranged in a matrix array are connected with each video line (D 1 to Dn) and, further, a source electrode of each pixel transistor (TFT) is connected with sub pixel electrode (PX). Here, naming of the drain electrode and the source electrode is determined based on a bias polarity between these electrodes originally, and in the liquid crystal display module of this embodiment, the bias polarity is reversed during operation and hence, the drain electrode and the source electrode are interchangeable with each other during operation. However, in this specification, for the sake of brevity, the explanation is made by assuming one electrode as the drain electrode and another electrode as the source electrode. Further, with respect to the gate electrodes of the pixel transistors (TFT) for each row of the respective sub pixels arranged in a matrix array, the gate electrodes of the pixel transistors (TFT) for every row are respectively connected with the scanning lines (G 0 to Gm), and the scanning lines (G 0 to Gm) are connected with the horizontal shift register circuit 110 . The respective pixel transistors (TFT) are turned on when a positive bias voltage is applied to the gate electrodes, and is turned off when a negative bias voltage is applied to the gate electrodes. Further, a liquid crystal layer is arranged between the pixel electrode (PX) and the counter electrode (CT) and hence, liquid crystal capacitance (LC) is equivalently connected with the respective pixel electrodes (PX), and holding capacitance (Cadd) is connected between the scanning line (G 0 to Gm) in a preceding stage and the pixel electrode (PX). The horizontal shift register circuit 110 and the vertical shift register circuit 120 shown in FIG. 1 are circuits arranged in the inside of the liquid crystal display panel (hereinafter, referred to as peripheral circuits). These peripheral circuits are respectively constituted of a thin film transistor using a semiconductor layer made of poly-silicon (hereinafter, referred to as poly-silicon thin film transistor) in the same manner as the pixel transistor (TFT) which constitutes the active element of each sub pixel. These poly-silicon thin film transistors are formed simultaneously with the pixel transistors (TFT) constituting the active elements of the respective sub pixels. In this embodiment, a scanning-line selection signal is sequentially outputted to the respective scanning lines (G 0 to Gm) from the vertical shift register circuit 120 for every 1 H period (scanning period). Accordingly, the pixel transistors (TFT) which have the gate electrodes thereof connected with the scanning line (G 0 to Gm) are turned on during 1 H period. Further, in this embodiment, switching transistors (SW 1 to SWn) are formed for the respective video lines (D 1 to Dn). The switching transistors (SW 1 to SWn) are sequentially turned on in response to a shift output of H level outputted from the horizontal shift register circuit 110 during 1H period (scanning period) so as to connect the video lines (D 1 to Dn) and a video signal line (SO) with each other. Hereinafter, the manner of operation of the liquid crystal display panel of this embodiment is briefly explained. The horizontal shift register circuit 110 shown in FIG. 1 sequentially selects the scanning lines (G 0 to Gm) in response to a start pulse and a vertical driving clock signal and outputs a positive bias voltage to the selected scanning line (G 0 to Gm). Accordingly, the pixel transistors (TFT) having the gate electrodes thereof connected with the selected scanning line (G 0 to Gm) are turned on. Further, the horizontal shift register circuit 110 sequentially turns on the switching transistors (SW 1 to SWn) during 1H period (scanning period) in response to the start pulse and the horizontal driving clock signal and connects the video lines (D 1 to Dn) and the video signal lines (SO) with each other. Accordingly, the video signals (voltages of the video signals) on the video signal lines (SO) are outputted to the video lines (D 1 to Dn), fetched video signals (voltages of the video signals) are written in the sub pixels whose pixel transistors (TFT) having the gate electrodes thereof connected with the selected scanning lines (G 0 to Gm) are turned on so that an image is displayed on the liquid crystal display panel. FIG. 2 is a plan view showing the electrode structure of the poly-silicon thin film transistor which is arranged in the peripheral circuit of this embodiment and uses the semiconductor layer made of poly-silicon, and FIG. 3 is a cross-sectional view showing the cross-sectional structure taken along a line A-A′ in FIG. 2 . As shown in FIG. 2 and FIG. 3 , the poly-silicon thin film transistor in the peripheral circuit of this embodiment is constituted of a source electrode 22 , a semiconductor layer 21 and a drain electrode 23 which are formed on a substrate (for example, a glass substrate) 24 , a gate insulation film 25 which is formed on the source electrode 22 , the semiconductor layer 21 and the drain electrode 23 , a gate electrode 1 which is formed on the gate insulation film 25 and above the semiconductor layer 21 , an interlayer insulation film 26 which is formed on the gate electrode 1 , a source line layer 3 , a gate line layer 2 and a drain line layer 4 which are formed on the interlayer insulation film 26 , and a protective film 27 which covers the gate line layer 2 , the drain line layer 4 and the source line layer 3 . Here, the source line layer 3 is connected with the source electrode 22 via a contact hole 6 formed in the gate insulation film 25 and the interlayer insulation film 26 , and the drain line layer 4 is connected with the drain electrode 23 via a contact hole 6 formed in the gate insulation film 25 and the interlayer insulation film 26 . Further, the gate line layer 2 is connected with the gate electrode 1 via a contact hole 6 formed in the interlayer insulation film 26 . Further, the source line layer 3 , the gate line layer 2 and the drain line layer 4 are formed of a metal layer (for example, aluminum layer, molybdenum layer or a tungsten layer). The poly-silicon thin film transistor shown in FIG. 2 and FIG. 3 is characterized in that the gate electrode 1 which is formed on the semiconductor layer 21 is covered with the gate line layer 2 which is made of metal such as, for example, aluminum, molybdenum or tungsten exhibiting high heat conductivity by way of the interlayer insulation film 26 . Due to such a constitution, heat which is generated during operation by the poly-silicon thin film transistor into which an electric current on the order of 500 μA or more flows during operation can be radiated by way of the gate line layer 2 and hence, it is possible to prevent the fluctuation of characteristic of the poly-silicon thin film transistor attributed to the self-heating of the poly-silicon thin film transistor. That is, although the self-heating of operation of the poly-silicon thin film transistor may become a cause of the fluctuation of the transistor characteristic such as a threshold value voltage (Vth), due to the above-mentioned structure of this embodiment, it is possible to prevent the fluctuation of transistor characteristic. Accordingly, the circuit operation lifetime can be prolonged thus enhancing the reliability of a product. Here, not only the structure in which the gate line layer 2 covers the whole gate electrode 1 but also the structure in which the gate line layer 2 covers a portion of the gate electrode 1 can acquire the above-mentioned advantageous effect. Accordingly, provided that an end portion of the gate line layer 2 is arranged within the gate electrode as shown in FIG. 4 , that is, provided that the end portion of the gate line layer 2 is arranged within the gate width (w) as viewed in the direction orthogonal to the substrate 24 , it is possible to acquire the above-mentioned advantageous effect. Here, FIG. 4 corresponds to a cross-sectional structure taken along a line B-B′ in FIG. 2 . FIG. 5 is a plan view showing another example of the electrode structure of the poly-silicon thin film transistor which uses a semiconductor layer made of poly-silicon in a peripheral circuit of this embodiment, and FIG. 6 is a cross-sectional view showing the cross-sectional structure taken along a line A-A′ in FIG. 5 . The poly-silicon thin film transistor shown in FIG. 5 and FIG. 6 is characterized in that the gate electrode 1 which is formed on the semiconductor layer 21 is covered with the source line layer 3 which is made of metal such as, for example, aluminum, molybdenum or tungsten exhibiting high heat conductivity by way of the interlayer insulation film 26 . The structure shown in FIG. 5 and FIG. 6 can also acquire the above-mentioned advantageous effect. Here, not only the structure in which the source line layer 3 covers the whole gate electrode 1 but also the structure in which the source line layer 3 covers a portion of the gate electrode 1 can acquire the above-mentioned advantageous effect. Accordingly, provided that an end portion of the source line layer 3 is arranged within the gate electrode as shown in FIG. 7 , that is, provided that the end portion of the source line layer 3 is arranged within a gate length (L) as viewed in the direction orthogonal to the substrate 24 , it is possible to acquire the above-mentioned advantageous effect. FIG. 8 is a plan view showing another example of the electrode structure of the poly-silicon thin film transistor which uses a semiconductor layer made of poly-silicon in the peripheral circuit of this embodiment, and FIG. 9 is a cross-sectional view showing the cross-sectional structure taken along a line A-A′ in FIG. 8 . The poly-silicon thin film transistor shown in FIG. 8 and FIG. 9 is characterized in that the gate electrode 1 which is formed on the semiconductor layer 21 is covered with the drain line layer 4 which is made of metal such as, for example, aluminum, molybdenum or tungsten exhibiting high heat conductivity by way of the interlayer insulation film 26 . The structure shown in FIG. 8 and FIG. 9 can also acquire the above-mentioned advantageous effect. Here, not only the structure in which the drain line layer 4 covers the whole gate electrode 1 but also the structure in which the drain line layer 4 covers a portion of the gate electrode 1 can acquire the above-mentioned advantageous effect. Accordingly, provided that an end portion of the drain line layer 4 is arranged within the gate electrode, that is, provided that the end portion of the drain line layer 4 is arranged within the gate length (L) shown in FIG. 7 as viewed in the direction orthogonal to the substrate 24 , it is possible to acquire the above-mentioned advantageous effect. FIG. 10 is a plan view showing another example of the electrode structure of the poly-silicon thin film transistor which uses a semiconductor layer made of poly-silicon in the peripheral circuit of this embodiment, and FIG. 11 is a cross-sectional view showing the cross-sectional structure taken along a line A-A′ in FIG. 10 . The poly-silicon thin film transistor shown in FIG. 10 and FIG. 11 is characterized in that the gate electrode 1 which is formed on the semiconductor layer 21 is covered with the source line layer 3 and the drain line layer 4 which are made of metal such as, for example, aluminum, molybdenum or tungsten exhibiting high heat conductivity by way of the interlayer insulation film 26 . In this case, the source line layer 3 and the drain line layer 4 are arranged on the gate electrode with a predetermined distance therebetween. The structure shown in FIG. 10 and FIG. 11 can also acquire the above-mentioned advantageous effect. Here, provided that an end portion of the source line layer 3 and an end portion of the drain line layer 4 are arranged within the gate length (L) shown in FIG. 7 as viewed in the direction orthogonal to the substrate 24 , it is possible to acquire the above-mentioned advantageous effect. FIG. 12 is a plan view showing another example of the electrode structure of the poly-silicon thin film transistor which uses a semiconductor layer made of poly-silicon in the peripheral circuit of this embodiment. The poly-silicon thin film transistor shown in FIG. 12 is a poly-silicon thin film transistor which adopts the diode connection for allowing the source electrode or the drain electrode to have the same potential as the gate electrode, and is characterized in that the gate electrode 1 formed on the semiconductor layer 21 is covered with the drain line layer 4 which is made of metal such as, for example, aluminum, molybdenum or tungsten exhibiting high heat conductivity by way of the interlayer insulation film 26 . The structure shown in FIG. 12 can also acquire the above-mentioned advantageous effect. Here, provided that an end portion of the drain line layer 4 is arranged within the gate width (w) shown in FIG. 4 or the gate length (L) shown in FIG. 7 as viewed in the direction orthogonal to the substrate 24 , it is possible to acquire the above-mentioned advantageous effect. As has been explained heretofore, according to this embodiment, the gate electrode of the poly-silicon thin film transistor which is formed on the substrate (for example, the glass substrate having low heat radiation property) is covered with the metal layer exhibiting high heat conductivity (for example, the gate line layer, the source line layer or the drain line layer) by way of the insulation film and hence, the heat generated when the poly-silicon thin film transistor is in an ON operation state can be radiated by way of the metal layer whereby it is possible to suppress the fluctuation of characteristic of the thin film transistor. Accordingly, the circuit operation lifetime can be prolonged thus enhancing the reliability of the product. Here, the above-mentioned structure of this embodiment can be particularly effectively applicable to the poly-silicon thin film transistor which generates heat by itself when an electric current of 500 μA or more flows therein during a normal circuit operation. Further, the substrate 24 is not limited to the glass substrate. That is, even when a substrate having the substantially same thermal expansion coefficient as the glass substrate is used as the substrate 24 , by applying the above-mentioned structure of this embodiment to such a substrate, it is possible to prevent the fluctuation of characteristic attributed to the self-heating of the poly-silicon thin film transistor. Further, although the above-mentioned explanation has been made with respect to the embodiment in which the present invention is applied to the liquid crystal display device, it is needless to say that the present invention is not limited to the above-mentioned embodiment and is also applicable to an EL display device which uses an organic EL element or the like, for example. Although the invention made by the inventors of the present invention have been specifically explained in conjunction with the embodiment heretofore, it is needless to say that the present invention is not limited to the above-mentioned embodiment and various modifications are conceivable without departing from the gist of the present invention.

A display device includes a display panel which forms a plurality of sub pixels on a substrate thereof, and a drive circuit which is configured to drive the plurality of sub pixels, wherein the drive circuit has a thin film transistor formed on the substrate, and the thin film transistor has a semiconductor layer made of poly-silicon. The thin film transistor includes: a source electrode, a semiconductor layer and a drain electrode which are formed on the substrate; a gate insulation film which is formed on the source electrode, the semiconductor layer and the drain electrode; a gate electrode which is formed on the gate insulation film and above the semiconductor layer; an insulation film which is formed on the gate electrode; and a metal layer which is formed on the insulation film in a state that the metal layer covers at least a portion of the gate electrode.

REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to EP Application No. 07113705.3 filed Aug. 2, 2007, entitled DEVICE, SYSTEM AND METHOD FOR TARGETING AEROSOLIZED PARTICLES TO A SPECIFIC AREA OF THE LUNGS, and is incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention is directed to the administration of aerosolized particles to specific areas of the lungs, and in particular to the targeted delivery of aerosolized pharmaceutical formulations to specific areas of the lungs. More specifically, the present invention relates to devices and methods for depositing aerosolized particles to specific areas of the lungs by regulating aerosolization parameters of the device. The present invention also relates to devices, systems and methods for disease management, where the aerosolization parameters are adjusted based on monitoring at least one health parameter. BACKGROUND OF THE INVENTION [0003] Effective drug delivery to a patient is a critical aspect of any successful drug therapy. Of particular interest to the invention are pulmonary delivery techniques which rely on the inhalation of a pharmaceutical formulation by the patient so that a drug or active agent within the formulation can reach the lungs. Pulmonary delivery techniques can be advantageous for certain respiratory diseases in that it allows selective delivery of optimal concentrations of pharmaceutical formulations to the airways while causing less side effects than systematic administration. Nevertheless, many patients have experienced significant side effects caused by the necessary dosage for drugs commonly used in pulmonary delivery. Therefore, there is still a need to eliminate undesirable side effects, which in some case may include an increased risk for heart attack. For reducing these side effects, a pharmacologic approach has been taken. However, in some cases, the new found drugs are significantly more expensive thereby representing a major disadvantage to patients from poorer socioeconomic populations. Therefore, it would be advantageous to provide an alternative to the pharmacologic approach, whereby commonly used drugs can be delivered in an effective manner without the undesirable side effects. [0004] It has been found that the efficacy of drug delivery can be improved by targeting the aerosolized medication to certain areas of the lungs. Delivery and deposition of aerosols are determined by both the aerosol characteristics and by patient's breathing characteristics. Many existing inhalation devices can deliver aerosolized particles to the lungs, yet lack the ability to target the delivery to certain areas of the lungs. [0005] U.S. Pat. No. 5,906,202 describes a device and method for directing aerosolized mist to a specific area of the respiratory tract. By determining the particle size of the aerosols in combination with determining the volume of aerosol and aerosol free air allowed into the respiratory tract, it is possible for the described device to target a particular area of the respiratory tract. The device can allow the subject to inhale a predetermined volume of unaerosolized air followed by a predetermined volume of aerosol after which flow can be shut off completely or followed by additional aerosol free air. To this end, inspiratory flow rate measurements are made in order to determine a desired flow rate. The device then comprises a switch for releasing the predetermined volume of aerosol and aerosol free air at the desired flow rate. However, if the subject is unable to control their inspired flow rate to the set value, she/he will never receive the drug. This represents a disadvantage. It is also well known that the inspired flow can affect aerosol deposition independent of inspired volume. Since the described device requires that the subject breathe at a specific flow to trigger the aerosol, if the subject changes their flow immediately at the point of aerosol triggering, the deposition can be significantly altered, thereby representing another disadvantage. Further, there is still a need for a simpler device which enables lower costs for manufacture. SUMMARY OF THE INVENTION [0006] It is an object of the present invention to provide improved devices, methods and systems which overcome the various aforementioned drawbacks of the prior art. [0007] It is also an object of the present invention to provide a method and device for depositing aerosolized particles to specific areas of the lungs which enables effective treatment using lower doses of the drug. [0008] It is also an object of the present invention to provide a disease management system which enables the aerosolization parameters of the device to be adapted depending on measurement of at least one health parameter. For example, the measurement may be a spirometer for measuring a pulmonary function parameter indicative of the subject's inhalation or exhalation capacity. The monitor may also be a cardio-sensor for measure heart rate. The monitor may also be a glucose sensor for invasively or non-invasively measuring blood glucose levels. [0009] The present invention relates to novel methods and devices for targeting aerosolized particles, preferably aerosolized pharmaceutical formulations, to specific areas of the lungs. The pharmaceutical formulations that may be aerosolized include powdered medicaments, liquid solutions or suspensions and the like and may include an active agent. [0010] The inventors have found that effective targeting of aerosol particle deposition can be achieved by presetting certain aerosolization parameters of the device. The methods and devices of the present invention enable effective treatment to be maintained with notable reduction in the normally required amount of drug thereby possibly reducing or eliminating side effects. Targeting can be achieved by altering aerosol parameters, such as volume, particle size, timing and flow rate. As for timing, the present invention allows or introduces particle free air for a first predefined time period, then introduces a certain amount of aerosolized particles, also commonly referred to as an aerosol bolus, followed by a second predefined period of aerosol particle free air. [0011] The first predefined period of particle free air is optional, as the device can be adapted to activate the introduction of the aerosolized particles or aerosol bolus upon sensing the subject's inhalation. This might be desirable in cases where the aerosolized particles should be deposited to the lower regions (alveolar regions) of the lungs. The object of introducing particle free air in the first predefined period is to direct air to the lower regions of the lungs. This helps to support ventilation (removal of carbon dioxide). The volume capacity of the lower regions of the lungs will vary depending on the subject. The first time period could represent the amount of estimated time that it takes to fill the lower regions of the lungs. This time period is generally preset depending on the subject's data and can be adjusted depending on what best suits the subject. [0012] For targeting of bronchial areas within the lungs preferably, the first predefined time period of aerosol particle free air is set to be up to about 10 seconds. Most preferably, the first predefined time period of aerosol particle free air is up to 6 seconds, in particular 1 to 5 seconds, 2 to 4 seconds. Preferably, the first predefined time period enables a predefined volume of aerosol particle free air, the predefined volume being up to 6 liters. Most preferably, the predefined volume of aerosol particle free air is about 0.1 to 3 liters, in particular 0.1 to 0.8 liters. [0013] For targeting of peripheral areas within the lungs, the first predefined time period of aerosol particle free air is set to be up to 3 seconds. Most preferably, the first predefined time period of aerosol particle free air is up to 0.2 seconds, in particular up to 0.06 seconds. Preferably, the first predefined time period enables a predefined volume of aerosol particle free air, the predefined volume being up to 0.4 liters. Most preferably, the predefined volume of aerosol particle free air is up to 0.04 liters, in particular 0.01 liters. [0014] The device is adapted to administer a desired volume of aerosolized particles and can be adapted to administer the aerosolized particles within a predetermined time period. This volume is determined by the amount of pharmaceutical formulation that should be deposited in the lungs. Preferably, the predefined volume of aerosolized particles or aerosol bolus is set to be up to about 3000 ml. Most preferably, the pre-set volume of aerosolized particles is about 50 to 1300 ml. in particular 100 to 300 ml. The predefined volume of aerosolized particles can be introduced into the flow path for a preset time period. The loading dosage of pharmaceutical formulation to be aerosolized corresponding to the aerosol bolus can vary. Preferably, the amount of pharmaceutical formulation is less than 500 mg, most preferably about 1 to 600 μg, in particular about 10 to 300 μg. [0015] After release of the predefined volume of aerosolized particles, a volume of aerosol particle free air is introduced for a predefined time period. The object of this time period of particle free air is to clear the upper region and extrathoracic airway region, respectively, (e.g., mouth, pharynx, and trachea) of the lungs to thereby drive the aerosol bolus to the central region (bronchial) or peripheral region of the lungs. Preferably, this predefined time period of aerosol particle free air is set to be up to about 10 second. Most preferably, this time period of aerosol particle free air is about 0.2 to 8 seconds, in particular 0.3 to 2 seconds. Preferably, this predefined time period enables a predefined volume of aerosol particle free air, the predefined volume being preferably up to 3 liters. Most preferably, this volume of aerosol particle free air is about 0.01 to 0.8 liters, in particular 0.05 to 0.3 liters. [0016] The length of the time periods can vary depending on which area of the lung is targeted for deposition. [0017] The present invention provides a device comprising a flow rate limiter or controller for limiting inhalation flow rate in a flow path to a preset flow rate range; and a timer to initiate, once a subject begins inhalation and has inhaled a first predefined time period of aerosol particle free air, a predefined volume of aerosolized particles to be introduced into the flow path, and to initiate after said predefined volume of aerosolized particles a second predefined time period of aerosol particle free air, such that the aerosolized particles are directed to the central airways of the lungs. [0018] The timer of the present invention serves to initiate the periods of aerosol particle and particle free flow. The timer can be in any form suitable in the field. Preferably, the timer is an electronic device which can be programmed or set with the predefined time periods. Preferably, the timer is adapted to indicate to the subject to stop inhaling after the subject has inhaled for the second predefined time period of aerosol particle free air or the device may further comprise an indicator to alert the subject to stop inhaling after the subject has inhaled for the second predefined time period of aerosol particle free air. The indicator may be an audible indicator that produces a tone or a visual indicator that flashes a light or changes color for alerting the subject. [0019] The flow limiter or controller of the present invention is for limiting or controlling inhalation flow rate in a flow path to be in a preset flow rate range. Preferably, the flow rate limiter is a discretely or continuously variable flow limiter or a controllable valve. Most preferably, the flow limiter has the features of the flow limiting device of U.S. Pat. No. 6,681,762, the control means of U.S. Pat. No. 6,571,791, or the controllable valve of US 2007/0006883 A1, the disclosures of which are incorporated herein by reference. [0020] In one embodiment of the flow limiter, the inspiratory flow is controlled by rigid and flexible walls that change cross sectional area as a function of the differential pressure across the orifices. [0021] For example, U.S. Pat. No. 6,681,762 describes a preferred embodiment of the flow limiter, wherein the flow passage is configured to have a flat elongate cross-section which is formed to have opposing large-area walls. This configuration enhances the inward bending of the walls for a reduction of the cross-section of the passage. The opposing walls are open on their outside, at least in the central area between the aspiration and inhalation orifices, to the environment, with each wall having preferably one chamber section on its outside, which is open via a bore to the environment, at least in the central area between the aspiration and inhalation orifices. With these structural provisions the required pressure equalization is ensured when the walls are contracted. [0022] In another embodiment, the flow limiter comprises a stratified structure for the flow passage, which comprises preferably a closed wall, a frame-shaped partition of the same size, and a wall of equal size with an aspiration and inhalation orifice, with the opposite walls being fastened on the sides of their edges in the housing. Any flexible and biologically tolerable material is suitable for configuring the flow passage, which material is flexible and can also be returned into its original shape after bending. It is preferred that at least the large-area passage walls, preferably also the partition, consist of silicone mats or foils whilst the housing is made of a preferably biologically tolerable material. [0023] In another embodiment of the flow limiter, the material layers of the flow passage are fastened for exchange between two housing sections. With such a structure, it is possible in a simple manner to use one flow limiter for different flow rate limiting parameters with a correspondingly associated flow passage. Each of the large-area passage walls has preferably the same thickness. [0024] In another embodiment of the flow limiter, provisions are made for a flow rate limitation independent of the environmental pressure, wherein each wall comprises on its outside a chamber section with a bore at least in the central area between the aspiration and inhalation orifices, which bores communicate with the aspiration orifice through a passage or a hose, respectively. With these provisions the differential pressure between the aspiration and inhalation orifices is measured, which is decisive for control, and flow rate limitation could also be operated in a closed system. [0025] According to a further embodiment of the flow limiter, the flow passage may have an annular cross-section, instead of a flat elongate cross-section, with the flow passage being preferably symmetrically disposed in a cylindrical housing at a spacing from the inside cylinder wall, between radial disks. These retainer disks are preferably provided with aspiration and inhalation orifices having the shape of ring segments, with the retainer disk having pressure equalizing bores for the cylindrical inside area and the annular zone surrounding the flow passage. This annular flow passage is preferably formed of silicone. [0026] In another embodiment of the flow limiter, provisions are made for the formation of the flow region between a central inhalation orifice and aspiration orifices radially surrounding them which region presents star-shaped or radial webs extending from a common bottom surface to the flexible wall and forming flow passages which can be restricted. With these provisions, the device can be designed with an extraordinarily compact structure that is easy to manufacture and to replace. [0027] The webs forming flow passages may have different lengths so that in the region of the longer webs a wider flow passage will be formed which then splits into several flow passages at intermediately arranged shorter webs. The cross-section of the webs may be constant in a radial direction. The webs flare outwardly over their width, with one aspiration orifice being preferably provided between two adjacent webs. [0028] In another embodiment, the flow limiter has a disk-shaped basic body wherein webs are integrally formed between flat recesses. Inhalation orifices are formed on the edge side in the recesses. The flow limiter has a thin flexible mat with a central aspiration orifice, which rests on the webs and is fastened in the edge region of the basic body. The mat may be adhesively fastened or welded, respectively, or clamped by means of an annular assembly element in the edge region of the basic body. The thin flexible mat is preferably made of silicone, silicone rubber, Viton, latex, natural rubber or any other elastomer. [0029] The flow limiter of the present invention may also be a control means as described in U.S. Pat. No. 6,571,791, wherein flow rate limiting is achieved by an adjustable channel height. In one embodiment, a flow channel is delimited preferably by two flexible walls arranged in parallel and spaced apart from each other, which, depending on the negative pressure, bends towards the inside and thus reduce the cross section of the channel, thereby limiting the flow. Other embodiments of the control means described in U.S. Pat. No. 6,571,791 are also suitable as flow limiters for the present invention and are enclosed herein by reference. [0030] The flow limiter of the present invention may also be a controllable valve as disclosed in US 2007/0006883. In one embodiment, the controllable valve comprise a housing, a membrane, an optional pressure plate, a closure element, a set piston and an adjusting screw, wherein the housing is essentially tubular and comprises a plurality of radially arranged webs, one web being longer than the others. On one side of the webs, the housing is designed so as to adjustably receive the set piston. On the opposite side so as to receive the membrane, the optional pressure plate and the closure element. The controllable valve allows for continuous or gradual flow control. Other embodiments of the controllable valve described in US 2007/0006883 are also suitable as flow limiters for the present invention and are enclosed herein by reference. [0031] In one embodiment of the present invention, the flow limiter is a control valve actuated by an inflatable balloon. [0032] In another embodiment of the present invention, the flow limiter is a piezo-controlled flow limiter, for example, comprising a flow channel having a height that is adjustable using a piezoelectric mechanism. [0033] Preferably, the device of the present invention comprises air control means responsive to the timer and adapted to seal the flow path after the subject has inhaled the second predefined time period of aerosol particle free air. Preferably, the air control means is an air shut off valve, air shut off channel, air control valve or the like. Preferably, the device comprises an air control valve for enabling a pre-settable volumetric flow of compressed air. Preferably, the air control means comprises a piezo-controlled valve, diaphragm-activated motor, solenoid, air piston and/or a mechanical valve operable with a timer. [0034] The device of the present invention preferably comprises a sensor in any suitable form for detecting when a subject is inhaling through the flow path. Preferably, the sensor comprises a pressure gauge responsive to suction pressure due to the subject's inhalation. In another embodiment, the sensor comprises a diaphragm responsive to sound waves caused by of the subject's inhaling. The diaphragm is preferably a microphone. In yet another embodiment, the sensor comprises a mechanical switch. In yet another embodiment, the sensor comprises a piezo membrane. Preferably, the sensor is placed at or within the inhaling channel of the device. [0035] The device of the present invention may be designed to receive a variety of detachable components, such as a mouthpiece, nebulizer or the like, and at least one cartridge or the like containing the pharmaceutical formulation. [0036] The device of the present invention may comprise a mouthpiece connected in fluid communication with the inhalation flow path. The mouthpiece may be a permanent part of the housing or a detachable part. [0037] Preferably, the device of the present invention comprises at least one orifice connectable to a source of aerosolized particles. The aerosolized particle source is preferably releasably or detachably connected to the device by any suitable means known in the art. The aerosolized particle source may be a powder dispersion device which utilizes a compressed gas to aerosolize a powder. The aerosolized particle source may be a nebulizer or the like, for aerosolizing solid or liquid particles. The nebulizer may be an ultrasonic nebulizer, a vibrating mesh nebulizer, a jet nebulizer or any other suitable nebulizer or vaporizer known in the field. These nebulizers can be separate components which can be attached to the device before use. [0038] The device of the present invention may also comprise a controller having a memory for storing a subject's individual parameters and/or aerosol depositing parameters. The timer of the present invention may be a component of the controller or a separate component connectable to the controller for receiving and/or sending information and/or data relating to the subject's aerosolization parameters. [0039] The device of the present invention may also comprise a reader for reading a memory means having a subject's individual parameters and/or aerosol depositing parameters stored thereon. The memory means can be in the form of any computer readable storage medium known in the art, such as but limited to a storage stick, memory disk or electronic data card, such as a smart card. The reader can be in any form as known in the art. For example, the reader can be an interface or port, e.g. a USB port or the like, for receiving a storage stick or a drive for receiving a memory or electronic data card. [0040] The device of the present invention may also comprise at least one communication means for receiving and/or sending data associated with a subject's individual parameters and/or aerosol depositing parameters. The communication means may be a wired connection or wireless connection sending and/receiving data via infrared, microwave or radio frequency, optical techniques or any suitable manner known in the art. The communication means may be a telephone connection or jack. This would be advantageous if a health provider, e.g. a doctor, would like to adjust the aerosol parameters from a remote location. For example, the first predefined time period, the second predefined time period, the predefined volume of aerosolized particles and/or the diameter size of the particle to be aerosolized could be adjusted remotely. [0041] The device of the present invention may also comprise at least one monitor for measuring a health parameter. The monitor may be a sensor or component, as known in the art, having suitable means for measuring a physiological factor. For example, the monitor may be a spirometer for measuring a pulmonary function parameter indicative of the subject's inhalation or exhalation capacity. The monitor may also be a cardio-sensor for measure heart rate. The monitor may also be a glucose sensor for invasively or non-invasively measuring blood glucose levels. [0042] The device of the present invention can be in any suitable form, such as a table-top device. Preferably, the device of the present invention is hand-held and portable. [0043] The present invention also relates to disease management methods and systems for monitoring and adapting the parameters for such targeting. The disease management system of the present invention provides at least the advantage of monitoring the health condition of the patient and being able to adjust the present device based on the subject's condition, thereby providing a more effective treatment in most cases. [0044] To this end, the system of the present invention comprises the device of the present invention and at least one monitor for measuring a health parameter, wherein the device is adaptable in response to measurements from one of said at least one monitor. [0045] The monitor may be any apparatus as known in the art for measuring a physiological factor. For example, the monitor may be a spirometer for measuring a pulmonary function parameter indicative of the subject's inhalation or exhalation capacity. The monitor may also be a cardio-sensor for measure heart rate. The monitor may also be a glucose sensor for invasively or non-invasively measuring blood glucose levels. The monitor may be a hand-held device. [0046] Preferably, the system comprises a base station having means for receiving and/or holding the device of the present invention and the at least one monitor. The receiving holding means can be a cradle. The base station preferably has a display for displaying any data and/or information. For example, the status or settings of the base station, device and/or monitor can be displayed. Preferably, the base station has control buttons for changing settings for the base station, device and/or monitor. [0047] The base station of the system also preferably has at least one communication means for receiving and/or sending data associated with a subject's individual parameters and/or aerosol depositing parameters and/or settings for the base station. The communication means may be a wired connection or wireless connection sending and/receiving data via infrared, microwave or radio frequency, optical techniques or any suitable manner known in the art. [0048] The present invention is also directed to methods for operating the aforedescribed devices and systems of the present invention. [0049] Further, the present invention is directed to a method of targeting aerosol particles to a specific area of the lungs comprising at least the steps of a) delivering a predefined volume of aerosolized particles to be inhaled into the flow path; and b) providing a predefined time period of aerosol particle free air into the lungs at a flow rate within the preset flow rate range to move the aerosolized particles to a targeted area of the lungs. [0050] For targeting aerosol particles to the central airways of the lungs, the method of the present invention may comprise a step before step a) of providing a first predefined time period of aerosol particle free air through a flow path into the lungs at a flow rate within a preset flow rate range. [0051] The method may further comprise a step of d) preventing flow through the flow path after providing the second predefined time period of aerosol particle free air. [0052] The method may further comprise a step of d) providing indication to the subject to stop inhaling after providing the second predefined time period of aerosol particle free air for the preset time period. [0053] Preferably, the method comprises a step of detecting when the subject is inhaling through the flow path. [0054] The method of the present invention may further comprise steps of measuring and adapting the first predefined time period, the second predefined time period and/or the predefined volume of aerosolized particles based on measurements of at least one health parameter. [0055] The present invention is also directed to a method for depositing aerosol particles to the central airways of the lungs comprising: a) providing a first predefined time period of aerosol particle free air through a flow path into the lungs at a flow rate within a preset flow rate range; b) delivering a predefined volume of aerosolized particles to be inhaled into the flow path; and c) providing a second predefined time period of aerosol particle free air into the lungs at a flow rate within the preset flow rate range to move the aerosolized particles out of the upper airway region. [0056] Preferably, the method further comprises d) preventing flow through the flow path after providing the second predefined time period of aerosol particle free air. Preferably, the method comprises d) providing indication to the subject to stop inhaling after providing the second predefined time period of aerosol particle free air for the preset time period. [0057] The method may also comprise detecting when the subject is inhaling through the flow path. [0058] Preferably, the flow rate is a predetermined fixed flow rate. Preferably, the first predefined time period of aerosol particle free air is up to about 10 seconds, the second predefined time period of aerosol particle free air is up to about 10 seconds and the predefined volume of aerosolized particles is up to about 3000 ml. Preferably, the first predefined time period enables a predefined volume of aerosol particle free air, the predefined volume being up to about 6 liters. Preferably, the second predefined time period enables a predefined volume of aerosol particle free air, the predefined volume is up to about 3 liters. [0059] Preferably, the predefined volume of aerosolized particles is introduced into the flow path for a preset time period. [0060] Preferably, the method further comprises steps of measuring and adapting the first predefined time period, the second predefined time period and/or the predefined volume of aerosolized particles based on measurements of at least one health parameter. [0061] The term “pharmaceutical formulation” as used herein, includes active ingredients, drugs, medicaments, compounds, compositions, or mixtures of substances bringing about a pharmacological, often advantageous, effect. It includes food, food supplements, nutrients, medicaments, vaccines, vitamins, and other useful active ingredients. Moreover, the terms, as used herein, include any physiologically or pharmacologically active substances, bringing about a topical or systemic effect in a patient. The active ingredient lending itself to administration in the form of an aerosol can be an antibody, antiviral active ingredient, anti-epileptic, analgesic, anti-inflammatory active ingredient, and bronchodilator or can be an organic or inorganic compound, which without any restrictions can also be a medicament having an effect on the peripheral nervous system, adrenergic receptors, cholinergic receptors, skeletal muscles, cardiovascular system, unstriated muscles, circulatory system, neuronal connections, pulmonary system, respiratory system, endocrine and hormonic system, immune system, reproductive system, skeletal system, food supply system and excretory system, histamine cascade or central nervous system. Suitable active ingredients are for instance polysaccharides, steroids, hypnotics and sedatives, activators, tranquilizers, anticonvulsives (antispasmodics) and muscle35 relaxants, anti-Parkinson-substances, analgesics, anti-inflammatory agents, antimicrobial active ingredients, antimalarial agents, hormones, including contraceptives, symphatocomimetics, polypeptides and proteins producing physiological effects, diuretics, substances regulating the lipometabolism, anti-androgenic active ingredients, antiparasitics, neoplastic and antineoplastic agents, antidiabetics, food and food supplements, growth-promoters, fats, stool-regulators, electrolytes, vaccines and diagnostics. [0062] The invention is particularly suited for inhalation application of different active ingredients, such as the following ones (without being restricted thereto): Insulin, calcitonin, erythropoietin (EPO), factor VII, factor IX, cylcosporin, granulozyte colony stimulating factor (GCSF), alpha-1-proteinase inhibitor, elcatonin, granulocyte macrophage colony stimulating factor (GMCSF), growth hormones, human growth hormone (HGH), growth hormone releasing hormone (GHRH), heparin, low molecular weight heparin (LMWH), interferon alpha, interferon beta, interferon gamma, interleukin-2, luteinizing hormone releasing hormone (LHRH), somatostatin, somatostatin-analogs, including octreotides, vasopressin analogs, follicle stimulating hormone (FSH), insulin-like growth factor, insulintropin, interleukin-I receptor antagonist, interleukin-3, interleukin-4, interleukin-6, macrophage colony stimulating factor (M-CSF), nerve growth factor, parathryoid hormone (PTH), thymosin alpha 1, IIb/IIIa inhibitor, alpha-1 antitrypsin, antibodies against respiratorily syncytic virus, cystic fibrosis transmembrane regulator gene (CFTR), desoxyribonuclease (Dnase), bactericides, permeability increasing protein (BPI), anti-CMV antibodies, interleukin-1-receptor, retinol, retinyl-ester, tocopherols and their esters, tocotrienols and their esters, carotinoids, in particular beta carotin and other natural and synthetic antioxidants, retinol acids, pentamides, albuterolsulfate, metaproterenolsulfate, beclomethasonedipropionate, triamcinolonacetamide, budesonidacetonides, ipratropium bromide, salbutamols, formanilides, flunisolides, fluticasones, cromolyn potassium, ergotamine tartrate and the analogs, agonists and antagonists of the above-mentioned substances. [0063] Moreover, active ingredients can be nucleic acids in the form of pure nucleic acid molecules, viral vectors, associated viral particles, nucleic acids associated with or contained in lipids or a lipid containing material, plasmid DNA or plasmid RNA or other constructs from nucleic acids, which are suitable for cell transfection or cell transformation, in particular in the case of cells of the alveolar region of the lung. [0064] The active ingredient can be present in different forms, such as soluble or insoluble, charged or uncharged molecules, components of molecular complexes or pharmacologically acceptable inactive ingredients. The active ingredient can consist of naturally occurring molecules or their recombinant products, or the molecules can be analogs of the naturally occurring or recombinantly produced active ingredients to which or from which one or more amino acids have been added or deleted. Moreover, the active ingredient can contain attenuated live vaccines or killed viruses for vaccination purposes. If the active ingredient is insulin, it includes naturally extracted human insulin, recombinant human insulin, insulin extracted from cattle and/or swine, recombinant porcine or bovine insulin and mixtures of the above-mentioned insulins. The insulin can be present in a substantially purified form, but can also contain usual commercial extracts. The term “insulin” also includes analogs, to which or from which one or more amino acids of the naturally occurring or recombinant insulin have been added or deleted. BRIEF DESCRIPTION OF THE DRAWINGS [0065] Some embodiments of the invention will be described with reference to the figures: [0066] FIG. 1 is a perspective view of an embodiment of a system according to the present invention. [0067] FIG. 2 is a front view of the system shown in FIG. 1 . [0068] FIG. 3 is an exploded view of components of the system shown in FIG. 1 . [0069] FIG. 4 is a top view of the system shown in FIG. 1 . [0070] FIG. 5 is a perspective view of another embodiment of a system according to the present invention. [0071] FIG. 6 is a front view of the system shown in FIG. 5 . [0072] FIG. 7 is an exploded view of components of the system shown in FIG. 5 . [0073] FIG. 8 is a top view of the system shown in FIG. 5 . [0074] FIG. 9 is a graph of measurements of forced expiratory volume versus time from experimental data comparing the present invention with prior art device and method. [0075] FIG. 10 is a graph of measurements of heart rate versus time from experimental data comparing the present invention and a prior art device and method. DESCRIPTION OF THE PREFERRED EMBODIMENT [0076] In FIGS. 1 to 4 , one embodiment of a system according to the present invention is illustrated. In this embodiment, system A comprises a device 10 according to the invention, a monitor 20 for measuring a health parameter and a base station 30 for receiving the device 10 and/or monitor 20 . [0077] As depicted, the device 10 can be hand-held, portable device. The device 10 has a housing with a mouthpiece 11 . The mouthpiece 11 may be removed or replaced by a compatible mouthpiece. To this end, a connection is provided in the housing of device 10 for enabling a detachable connection with the mouthpiece 11 . Alternatively, mouthpiece 11 may be an integral part of the housing of the device 10 . Device 10 is also adapted to receive a cartridge or receptacle 40 holding the pharmaceutical formulation or drug. For example, the housing of device 10 can be manufactured such that cartridge 40 can simply be inserted into the top of the device as shown in FIG. 3 . [0078] The monitor 20 can also be a hand-held, portable device as shown. Monitor 20 may also have control buttons for controlling the operations of the monitor and/or a display for showing measured results and/or settings. Monitor 20 can be a spirometer for measuring a lung function parameter, for example the inhalation or the exhalation capacity of the subject. [0079] The base station 30 includes cradles 32 , or the like, for holding the device 10 and monitor 20 . The base station 30 may also serve as a charger for recharging any batteries provided in device 10 and/or monitor 20 . To this end, cradles 32 may include an interface enabling an electronic connection with device 10 or monitor 20 . The interface could also enable the transfer of data between the base station 30 and the device 10 or monitor 20 . As depicted, base station 30 may also have a display 31 for displaying any desired information or data, for example the status of the base station 30 , device 10 and/or monitor 20 . Base station 30 may optionally include a slot 34 for receiving a memory card, e.g. a smart card, having data with the subject's aerosol parameters. In this respect, multiple users could use the base station 30 for adapting their inhalation devices 10 . Base station 30 may also include an additional reader for reading a storage medium like a memory stick. Although not shown, base station 30 may include communication means for enabling wired or wireless telecommunication and/or data transfer to and from a remote location. [0080] FIGS. 5 to 8 show an alternative embodiment of the system of the present invention. In this embodiment, system B comprises a device 100 according to the invention and a base station 300 for receiving device 100 . The device 100 and base station 300 can have the same features as device 10 and base station 30 respectively. Different from device 10 , device 100 also comprises a monitor or monitoring means and can function as both inhalation device and health parameter monitor. For example, device 100 can be an integrated inhalation device and spirometer as shown in FIGS. 5 to 8 . As shown in FIG. 7 , device 100 can also be configured to receive at least one drug cartridge 40 . [0081] In FIGS. 1 to 8 , exemplary systems are shown for respiratory disease management (RDM). However, modifications of the present system are possible for other types of disease management. Also, variations of illustrated systems A and B are possible. For example, the base station 30 of system A may be used for receiving device 100 having an integrated spirometer and an additional monitor for measuring a health parameter such as a cardio-monitor measuring heart beat rate for example. [0082] An experiment was performed to test the effectiveness of targeting aerosolized particles to specific areas of the lungs using the methods and devices of the present invention. The experiment was made using albuterol, a drug commonly used to treat asthma as an aerosol. Although commonly used in the field of asthma treatment, many patients have reported several undesirable side effects including palpitations, tremors and nervousness. It has been found in the field that the side effects of albuterol are directly related to the dose delivered and absorbed in the blood stream. [0083] As indication of the degree of bronchodilation, a spirometer was used to measure the forced expiratory volume per sec (FEV1) at several points in time. As an indication of the side effects of the drug, the heart rate of the subject was measured. Tremor effects were measured by a finger accelerometer. For the experiment, a nebulizer was used. The nebulizer was built around a small vibrating disk that has 4,000 laser precision drilled holes in it. The disk was vibrated on the surface of the Albuterol at more than 100,000 times per second. This pulled the liquid through the holes to form droplets of precise uniform size. [0084] In the experiment, data was measured for five different cases; A, B, C, D and E, each having different aerosol parameters: [0085] In Case A, a conventional device and method were used, and no targeting of the aerosolized particles was performed. A 2500 μg albuterol formulation was nebulized, which represents approximately the typical adult dose used in conventional nebulizers for achieving maximal bronchodialation. [0086] In Cases B, C, D and E, the device and methods of the present invention were used. [0087] In Case B, the aerosolized particles were targeted to the large airways of the lungs using a 6-micron diameter particle size and 104 μg albuterol loaded into the device with 50 μg deposited. [0088] In Case C, the aerosolized particles were targeted to the large and small airways of the lungs using a 3.5-micron diameter particle size and 188 μg albuterol loaded into the device with 50 μg deposited. [0089] In Case D, the aerosolized particles were targeted to the alveolar airways of the lungs using a 3.5-micron diameter particle size and 98 μg albuterol loaded into the device with 50 μg deposited. [0090] In Case E, the aerosolized particles were targeted to the large and small airways of the lungs using a 3.5-micron diameter particle size and 282 μg albuterol loaded into the device with 75 μg deposited. [0091] Referring to FIGS. 9 and 10 , the experimental results of the measured FEV1 and heart rate over a period of time are depicted for Cases A, B, C, D and E. Although Case A exhibited a maximal bronchodilation, the heart rate significantly increased thereby representing a heart attack risk for the subject. [0092] Case B resulted in a notable bronchodilation, yet significantly less than the degree of bronchodilation achieved with Case A. However, in contrast to Case A, the heart rate remained stabile. [0093] With Case C, a very good bronchodilation was achieved, which was approximately equivalent to that of Case A. In contrast to Case A, the heart rate remained stabile. Also, a significantly lower amount of albuterol was sufficient for achieving similar degree of bronchodilation as that of Case A. [0094] In Case D, the same amount of albuterol was used as Case C. However, the lower region (alveolar) of the lungs was targeted. The degree of bronchodilation was significantly lesser than that of Case A. However, in contrast to Case A, the heart rate remained stabile. [0095] For Case E, the large and small airways were targeted as in Case C. However, the deposited dose of albuterol was increased by 50 percent to 75 μg. Case E resulted in very good bronchodilation with FEV1 measurements being almost equivalent to those of Case A. However, in contrast to Case A, the heart rate remained stabile. [0096] Also, as can be seen in FIGS. 9 and 10 , Cases C and E had the same duration of effect as Case A. Cases B, C, D and E lead to less tremor effects as Case A. Hence, the experimental data suggest that, using significantly less than the normal dose, the present invention provides equivalent bronchodilation, equivalent duration of effect and induces less cardiac stimulation and tremor effects In particular, the experimental results show that the efficacy of a pharmaceutical formulation can be notably increased, without involving a significantly increase in dose amounts and side effects, by targeting the aerosolized formulation to certain areas of the lungs using the device of the present invention. This provides valuable advantages for the subject, especially in terms of reducing possible health risks associated with various pharmaceutical formulations. Subjects would benefit by needing only a small percentage of the typical drug dose to attain the same therapeutic effects. [0097] The various embodiments and experimental results presented in the specification are used for the sake of description and clarification of the invention, and thus should not be interpreted as limiting the scope of the invention as such. Moreover, the present invention is realized by the features of the claims and any obvious modifications thereof. LIST OF REFERENCE NUMERALS [0000] A system 10 device 11 mouthpiece of device 20 spirometer 30 base station 31 display 32 cradle 34 slot for reader 40 drug cartridge B system 100 device 110 mouthpiece of device 300 base station 310 display 320 cradle

The present invention is directed to the administration of aerosolized particles to specific area of the lungs, and in particular to the targeted delivery of aerosolized pharmaceutical formulations to a specific area of the lungs. More specifically, the present invention relates to devices and methods for depositing aerosolized particles to a specific area of the lungs by regulating aerosolizing parameters of the device. The present invention also relates to devices, systems and methods for disease management, where the aerosolizing parameters are adjusted based on monitoring at least one health parameter.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention concerns a process for pretreating high temperature, petroleum containing formations so petroleum may be recovered therefrom by the use of temperature sensitive polymers. 2. Description of the Prior Art Many subterranean, petroleum containing formations contain natural energy in the form of an active bottom water drive, solution gas drive, or a gas cap drive, in sufficient quantity to drive the petroleum through the formation to the production well from which it may be recovered to the surface of the earth. This phase of oil recovery, commonly known as primary recovery, recovers only a small portion of petroleum originally in place. When the natural energy source has been depleted, or in those formations where insufficient natural energy was originally present to permit primary recovery, some form of supplemental treatment is required to recover additional petroleum from the formation. Water flooding is by far the most economical and widely practiced supplemental recovery procedure and involves injecting water into the formation by one or more injection wells. The injection water displaces or moves the petroleum toward one or more production wells, where it is transported to the surface of the earth. Although considerable additional oil is usually recovered as a consequence of water flooding, as a general rule around 50% or more of the oil originally present in the formation remains in the formation after termination of water flooding. It is well known in the field of oil recovery that the inclusion of even a small amount of a hydrophilic polymer in the flood water will increase the displacement efficiency by a substantial amount. Many materials have been proposed for use in polymer flooding oil recovery processes. Polyacrylamides and polysaccharides are very effective for use in oil recovery operations in dilute concentrations, i.e., from 200 to 1000 parts per million. Sulfated, ethoxylated alkyl or alkylaryl compounds are also effective in slightly higher concentrations. Although it has been demonstrated in laboratory tests and published in the art, that the inclusion of a hydrophilic, viscosity increasing material in flood water will recover substantial amounts of additional petroleum from petroleum formations under ideal conditions, there are many conditions existing in subterranean petroleum containing formations which significantly degrades the performance of polymer solution injection. One of the most serious problems is the temperature limitation of most polymers. Most of the polymers proposed up to the present time for use in polymer flooding oil recovery processes will hydrolyze or otherwise deteriorate in aqueous solution when exposed to temperatures in excess of 150° F-200° F for long periods of time. Since a great many subterranean petroleum containing formations are hotter than 150° F-200° F, and since the polymer solution injected into a subterranean, petroleum-containing formation will ordinarily be in the formation for a period of many months or even years, the hydrolysis or other degradation of this polymer material reduces the polymer flooding recovery efficiency substantially. In our U.S. Pat. No. 3,924,682 issued Dec. 9, 1975, there is disclosed a method for treating a subterranean oil formation to reduce it's temperature to permit use therein of a temperature sensitive surfactant. In view of the foregoing discussion, it can be appreciated that there is a substantial, unfulfilled need for a method for conducting a polymer oil recovery process in subterranean, petroleum containing formations whose temperature is in excess of 150° F-200° F. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates the formation temperature at the injection well at three values of cooling fluid injection rates. FIG. 2 illustrates the temperature in a formation at various distances from the point of injection of a 70° F cooling liquid at seven different injection rates. SUMMARY OF THE INVENTION We have discovered that it is possible to cool a subterranean, petroleum containing formation to a temperature below the temperature limits of the hydrophilic polymer solution to be employed in a polymer oil recovery process in the formation. It is possible to achieve the temperature reduction in some cases by injection of surface ambient temperature water into the formation for a period of time substantially longer than would ordinarily be accomplished in a conventional water flooding operation, i.e. for long periods of time past the point when the produced fluid is essentially 100% water. In another embodiment, the water or other aqueous fluid being injected into the subterranean formation is cooled to a temperature lower than surface ambient temperature prior to injection of the aqueous fluid into the formation. Mechanical refrigeration, gas adsorption, or direct evaporization in air in arid climates may be utilized to cool the water prior to injection into the formation. If the reservoir parameters are known, the time necessary to inject an aqueous fluid of any available or preselected temperature into the formation in order to reduce the temperature of the formation to the desired level may be calculated by means disclosed herein below. The aqueous cooling fluid may also contain chemicals for the purpose of accomplishing other desired chemical pretreatment of the formation, such as adjusting the salinity and/or hardness of the formation water to the point at which optimum polymer response is achieved, or sacrificial adsorption reagents may be included for the purpose of accomplishing other desired chemical pretreatment of the formation, such as adjusting the salinity and/or hardness of the formation water to the point at which optimum polymer response is achieved, or sacrificial adsorption reagents may be included for the purpose of adsorbing on the formation surfaces to prevent polymer adsorption, or incorporating a chemical to control water sensitive clay materials contained in the formation so as to prevent loss of formation permeability. DESCRIPTION OF THE PREFERRED EMBODIMENT Briefly, the process of our invention involves introducing a fluid into a subterranean, petroleum containing formation, the fluid being at a lower temperature than the formation and passing the cooling fluid through the formation for a period of time sufficient to reduce the formation temperature so that the temperature sensitive polymers may be injected safely into the formation for oil recovery purposes. The temperature of the cooling fluid should be substantially less than the maximum temperature at which the polymer is stable. Preferably the temperature of the cooling fluids is at least 50° F less than the maximum temperature at which the polymer is stable. Water injection or water flooding is, of course, well known in the art of oil recovery, and when surface temperature water is injected into a subterranean, petroleum-containing formation for the purpose of displacing the petroleum toward the production well in a conventional waterflood operation, a limited amount of cooling of portions of the formation occurs as a necessary consequence of water injection. It is common practice in water flooding, however, to terminate water injection when the water-oil ratio begins to increase to the point that further fluid production is no longer economically feasible. As a general rule, the water-oil ratio will be quite low initially since a bank of oil is formed in the formation as a consequence of water injection, and little or no water is produced along with the oil during the time that this bank of oil is being produced. Once the trailing edge of the bank reaches the production well, the percentage of water produced increases rapidly. Once the water-oil ratio is above about 25 or 30, further injection of water and production of water and oil from the production well is no longer economically feasible in the ordinary context of secondary recovery, and so water injection is terminated and further production of fluids from the production wells is similarly terminated. Since the production is terminated shortly after water reaches the production well, very little cooling water will have passed through the formation in the immediate vicinity of the production well, and so the formation cooling effect in conventional water flooding is restricted to the portion of the formation immediately adjacent to the water injection well and does not extend sufficiently far into the formation to accomplish the desired result of reducing the over all formation temperature so temperature-sensitive polymers may be utilized therein. Frequently polymers are used in combination with surfactants and formation cooling will be required if either the surfactant or the polymer is unstable at the natural formation temperature. If both the surfactant and the polymer are temperature sensitive, then the formation temperature must be reduced to a value less than the lower of the temperatures limits of surfactant and polymer. It is often possible to achieve the desired formation temperature reduction by continuing injection of surface ambient temperature water such as is used in water flooding operations for a much longer period of time than would ordinarily be done in a conventional water flood operation. This requires that water injection must continue long after the fluid being produced at the production well goes to substantially 100% water. The produced water may be recirculated to minimize water disposal problems, but in that event it will usually be necessary to cool the water prior to reinjecting it since the water temperature exiting from the production well will naturally be considerably higher than the temperature of the water being injected due to its' contact with the hot formation. If a convenient disposal area is available for the water, and an abundant supply of suitable injection water is available, the desired temperature reduction may be achieved by simply continuing injecting surface-ambient temperature water into the formation. In any event, it will be necessary to determine the time duration of water injection, and this will be accomplished in essentially the same manner as if the water is cooled prior to being injected. The method for calculating the injection time necessary to achieve a desired temperature reduction will be given hereinafter below. In some situations, the practice of the process of our invention involves a cooling process whereby the temperature of the water is reduced either below surface ambient temperature or below the temperature of the water being produced from the production well in the case where produced water is recycled. Water may be cooled by the use of mechanical refrigeration or a gas fired adsorption process. If the operation is being conducted in an fairly arid region, it is satisfactory to pass the water through a cooling tower or some similar device to expose the water to dry air so that the water will be cooled by evaporation. Direct heat exchangers may also be used in the instance of application of the process of our invention during winter months or in cold climates. Whenever possible, it is preferred to use air evaporation or direct air heat exchangers to avoid the use of mechanical refrigeration because of the higher operational costs involved in mechanical cooling processes. The fluid may be cooled to any temperature above its freezing point and substantially less than, preferably at least 50° F less than the maximum temperature at which the polymer to be used is stable for the period of time it will be in the formation. The calculation of the time which water injection is required to achieve the desired temperature drop involves first calculating the heat gained by the injected cold water as it passes down the injection well bore and then from the point of injection radially outward into the formation. The problem then becomes essentially the same as one of calculating the heat loss in the instance of injecting a thermal fluid, which problem has been quite well worked out for steam injection situations. The only difference is that heat is gained as the fluid passes down the injection well bore and outward into the formation, rather than being lost as is the case for steam flooding. The heat loss-gain problem becomes one more readily handled if it is subdivided into the two principal steps: 1. The heat gained as the cold fluid is injected down the injection well bore, and; 2. The heat gained as the fluid passes from the point of injection radially outward into the formation. In the first step of calculating the heat gained by the injected cold fluid, consider the passage of the fluid through a radial injection well bore. The heat gained by the flowing fluid may be expressed by means of the following equation (1). Q.sub.G = H.sub.out - H.sub.in = q.sub.w C.sub.w w (T.sub.out - T.sub.in) (1) where Q G = heat gained by the fluid passing down the injection well bore. H in = enthalpy of the water at the inlet end of the injection well bore. H out = enthalpy of water at the outlet end of the injection well bore. q w = volumetric water injection rate C w = the specific heat capacity of water w = water density T in = tubing temperature at the inlet end T out = tubing temperature at the outlet end. Assuming that the amount of heat transferred across the well annulus from the formation to the fluid passing through the injection well is instantaneously supplied from the formation gives equation (2): Q.sub.G = UA.sub.to (T.sub.c - T.sub.t) = πD.sub.c LΦ(2) the middle term represents an overall heat transfer across the annulus: U = overall heat transfer coefficient A to = total heat transfer area T t = average tubing temperature, (T out - T in )/2 T c = average casing temperature The right hand side represents conductive heat transfer from the formation around the well bore: D c = casing diameter L = casing length of the controlled segment Φ = heat flux determined by a superposition method based on the variation of T c with time. By considering that the injection well is divided along its long axis into a number of segments, equation 1 is solved for each segment from the well head to the sand face by a trial and error method to determine the injected water temperature at the sand face. Since in most formations, there is a relatively constant thermal gradient between the surface and the formation, the calculations are relatively straightforward. The second step involves determining the heat gained by the injection fluid as it passes outward from the point of injection into the formation. Assuming essentially radial spreading of the injected fluid uniformly throughout the full formation thickness, gives equation (3): ##EQU1## i.e. Heat Accumulation = Heat Conduction In -- Heat Conduction Out + Heat Flux from Bonding Formation + Heat Convection In -- Heat Convection Out, where r = radial coordinate h = reservoir thickness (ρC)p = composite heat capacity of pay zone ΔT = temperature increment k p = pay zone thermal conductivity Δt = time increment z = vertical coordinate k s = bonding formation thermal conductivity i w = water injection rate H cw = enthalpy of injected cold water H w = enthalpy of water at reservoir temperature T cw = injected water temperature (sand face) T o = reservoir temperature The above equation may be solved numerically to obtain the temperature distribution in the reservoir as a function of injection time. Solutions of this equation for a series of preselected values of time of injection and water temperature yield a series of curves similar to that given in the attached FIG. 2 for a particular application. Any one curve gives the temperature in the formation as a function of distance from the point of injection. EXAMPLES Mathematical calculations based on the above formula were performed using field data from the Caillou Island Field in Louisiana. The reservoir properties and completion data are listed in Table I. TABLE I______________________________________RESERVOIR AND COMPLETION DATACaillou Island FieldDepth 11,000 ft.Formation Thickness 27 ft.Reservoir Temperature 214° FPermeability 2,400 millidarciesPorosity 27%Oil Saturation 65%Oil Viscosity 0.10 centipoise at 214° FWater Viscosity .28 centipoise at 214° F______________________________________ The calculations were made on the assumption that a 30 acre inverted five spot pattern was used, that the injection tubing was three inches internal diameter and the casing was five inches internal diameter. Calculations were made for injection rates of 300, 600, and 1,000 barrels of water per day, at an assumed injection water temperature of 70° F. In the first step, the water at the injection well point of entrance into the formation, e.g. the sand face temperature was calculated for each of the three injection rates, and the results are shown graphically in FIG. 1. The sand face temperature as a function of time for the three injection rates are given in FIG. 1. It can be seen that the sand face temperature drops dramatically in the first 10 days of cold water injection, and thereafter levels off to a nearly constant value quite rapidly. The value at which it becomes constant is, however, a function of the cold water injection rate, with the sand face constant temperature being lower with high injection rates. The formation temperature at any point away from the injection well is shown in FIG. 2 for the 600 barrel per day injection rate case. As can be seen, depending on the number of days of injection, one can determine the temperature at any particular distance from the injection well. All of the temperature profile lines tend to approach the original formation temperature, but the distance from the injection well at which they reach the original formation temperature increases with increasing periods of cold (70° F in this case) water injection. At greater injection rates, the formation temperature reduction to the desired level can be extended further into the formation away from the point of injection. For example, at a water injection rate of 1,000 barrels per day and an injection period of 1600 days, the reservoir temperature 200 ft. from the injection well can be lowered from 214° F to less than 150° F. It can be seen from the above that the cooling effect may be increased by injecting colder water, or for constant temperature water, by injecting at a higher rate or for longer periods of time. Of course, the polymer solution should be injected at or near the same temperature as the cooling fluid solution in order to maintain the reduced temperature effect within the formation. The temperature profile lines shown in the attached figures are dynamic conditions, and the temperature at any point in the formation will increase with time after the injection of cold fluid into the formation is terminated. Accordingly, any fluids injected prior to the polymer solution or the polymer solution itself should similarly be reduced in temperature to the desired cooling fluid temperature in order to ensure that the polymer solution is not subjected to temperatures greater than its decomposition level. It is generally preferable to cool any subsequent water injection after injecting the polymer solution to avoid a temperature rise at the trailing edge of the polymer solution, and surface ambient temperature water may be used to displace the polymer solution through the formation so long as a suitable quantity of cold fluid has been injected subsequent to the polymer solution. Field Example The following field example is offered for purposes of additional disclosure only and is not intended to be in any way limitative or restrictive of our invention. A polymer flood is contemplated in a reservoir having the following properties: ______________________________________Depth 1,646 meters (5,400 ft.)Thickness 10.4 meters (34 ft.)Reservoir Temperature 52° C (154° F)Permeability 0.3 μm.sup.2 (315 md.)Porosity 27%Initial Oil Saturation 58%Oil Viscosity .0021 Pa-s (2.1 centipoise)at the formation temperature______________________________________ In the first step, heat gain calculations are performed as given above assuming 70° F water temperature, and it is determined that at an injection rate of 300 barrels of 70° F water per day the temperature at the sand face drops initially as described previously, and then levels out at approximately 102° F. At 600 barrels of 70° F water per day, the sand face temperature becomes constant at about 90° F; at 1000 barrels of 70° F water per day, the sand face temperature levels out at about 80° F; at 3000 barrels of 70° F water per day, the constant level is about 75° F; and at 5000 barrels of water per day, about 70° F. The formation temperature at depth was determined for the 1000 barrels of water per day injection rate case assuming the injection water temperature is 70° F. The formation temperature is reduced to 125° at 50 ft. distance in 50 days; at approximately 75 ft. in 80 days; at approximately 105 ft. in 160 days; at 164 ft. in 400 days; at 210 ft. in 1200 days; and 240 ft. in 2000 days. Based on the above calculations, the flood is performed as follows. Cold water at a temperature of 70° F is injected into the formation at an injection rate of 1000 barrels per day for 400 days, until a total of 400,000 barrels of cold water has been injected. Thereafter a 102,816 barrel slug of polymer solution is injected into the formation at 1000 barrels per day. The fluid used comprises 500 parts per million of a partially hydrolyzed polyacrylamide. The temperature of the polymer solution is also maintained at 70° F in order to maintain the dynamic cooling conditions in the formation. After conclusion of the polymer solution injection phase, 70° water is injected into the formation to displace the polymer solution through the formation. The above calculations are based on a five acre, five spot pattern. Using a five acre, five spot pattern, an additional 34.6 percent of the reservoir is swept, resulting in a like increase in amount of oil recovered. In using a 30 acre pilot, only six additional percent is recovered because of the difficulty in cooling the greater areas involved using the same water temperature and injection rate. Thus we have disclosed and shown how a subterranean petroleum containing formation may be exploited by means of polymer flooding even though the safe temperature limit of the polymer is substantially below the formation temperature if the formation is first preconditioned by injecting cold fluid such as water at a temperature well below the polymer temperature limit into the formation for a suitable period of time to reduce the formation temperature to a safe limit. While our invention has been described in terms of a number of illustrative embodiments, it is not so limited since many variations thereof will become apparent to persons skilled in the art of supplemental oil recovery without departing from the true spirit and scope of our invention. Similarly, while a mechanism has been described to explain the benefits resulting from the use of our process, it is not necessarily represented hereby that this is the only or even the principal mechanism responsible for these benefits, and we do not wish to be bound by any particular explanation of the mechanism involved. It is our intention and desire that our invention be restricted and limited only by those limitations and restrictions as appear in the Claims appended hereinafter below.

Polymer flooding is an effective means of increasing the sweep efficiency of a displacement process for recovering petroleum from a subterranean, petroleum containing formation; however, most polymers suitable for use in flooding operations hydrolyze or otherwise decompose at temperatures above about 150° F to 200° F, and the temperature of many subterranean petroleum-containing formations is in excess of 150° F-200° F. Polymers may be employed in tertiary recovery in formations whose temperatures are greater than the temperature stability limit of the polymer if the formation temperature is first reduced by introducing an aqueous fluid such as water at a temperature substantially below the temperature limit of the polymer into the formation for a period of time sufficient to reduce the formation temperature to a value at or below the temperature tolerance level of the polymer.

[0001] This invention relates to nonwoven fabrics and to fabric laminates which comprise multiconstituent fibers formed from a select combination of polyolefin polymers. The invention more particularly relates to nonwoven fabrics and laminates of the type described having improved fabric properties and processing characteristics. [0002] Nonwoven fabrics produced from spun polymer materials are used in a variety of different applications. Among other uses, such nonwoven fabrics are employed as the cover sheet for disposable diapers or sanitary products. There is considerable interest in making disposable diapers more comfortable and better fitting to the baby. An important part of the diaper comfort is the softness or hardness of the nonwovens used to make the diaper, including the diaper topsheet, barrier leg cuffs, and in some advanced designs, the fabric laminated to the backsheet film. In some diaper designs, a high degree of fabric elongation is needed to cooperate with elastic components for achieving a soft comfortable fit. [0003] One approach to improved diaper topsheet softness is to use linear low density polyethylene (LLDPE) as the resin instead of polypropylene for producing spunbonded diaper nonwoven fabrics. For example, Fowells U.S. Pat. No. 4,644,045 describes spunbonded nonwoven fabrics having excellent softness properties produced from linear low density polyethylene. However, the above-described softness of LLDPE spunbonded fabric has never been widely utilized because of the difficulty in achieving acceptable abrasion resistance in such products. The bonding of LLDPE filaments into a spunbonded web with acceptable abrasion resistance has proven to be very difficult. Acceptable fiber tie down is observed at a temperature just below the point that the filaments begin to melt and stick to the calender. This very narrow bonding window has made the production of LLDPE spunbond fabrics with acceptable abrasion resistance very difficult. Thus, the softness advantage offered by LLDPE spunbonded fabrics has not been successfully captured in the marketplace. [0004] The present invention is based upon the discovery that blending a relatively small proportion of polypropylene of a select class with the polyethylene imparts greatly increased abrasion resistance to a nonwoven fabric formed from the polymer blend, without significant adverse effect on the fabric softness properties. It is believed that the polyethylene and the polypropylene form distinct phases in the filaments. The lower-melting polyethylene is present as a dominant continuous phase and the higher-melting polypropylene is dispersed in the dominant polyethylene phase. [0005] A number of prior publications describe fibers formed of blends of linear low density polyethylene and polypropylene. For example, U.S. Pat. No. 4,839,228 and EP 394,954 teach that useful fibers are formed from blends which are predominantly polypropylene. WO 90/10672 describes that useful fibers are prepared from blends of polypropylene and polyethylene, especially LLDPE, where the ratio of polypropylene to polyethylene is from 0.6 to 1.5. U.S. Pat. No. 4,874,666 describes fibers formed from a blend of LLDPE and high molecular weight crystalline polypropylene of melt flow rate below 20 g/10 minutes. U.S. Pat. Nos. 4,632,861 and 4,634,739 describe fibers formed from a blend of a branched low density polyethylene blended with from 5 to 35 percent polypropylene. SUMMARY OF THE INVENTION [0006] In accordance with the present invention, nonwoven fabrics and nonwoven fabric laminates are formed from fibers of a select blend of specific grades of polyethylene and polypropylene which give improved fabric performance not heretofore recognized or described, such as high abrasion resistance, good tensile properties, excellent softness and the like. Furthermore, these blends have excellent melt spinning and processing properties which permit efficiently producing nonwoven fabrics at high productivity levels. [0007] The nonwoven fabrics of the present invention are comprised of fibrous material in the form of continuous filaments or staple fibers of a size less than 15 dtex/filament formed of a dispersed blend of at least two different polyolefin polymers. The polymers are present as a lower-melting dominant continuous phase and at least one higher-melting noncontinuous phase dispersed therein. The lower-melting continuous phase forms at least 70 percent by weight of the fiber. The physical and rheological behavior of these blends is part of a phenomenon observed by applicants wherein a small amount of a higher modulus polymer reinforces a softer, lower-modulus polymer and gives the blend better spinning, bonding and strength characteristics than the individual constituents. The lower melting, relatively low molulus polyethylene provides desirable properties such as softness, elongation and drape; while the higher-melting, higher modulus polypropylene phase imparts one or more of the following properties to the dominant phase: improved ability to bond the web; improved filament tie-down (reduces fuzz); improved web properties-tensiles, and/or elongation and/or toughness; rheological characteristics which improve spinning performance and/or web formation (filament distribution). [0008] According to one advantageous and important aspect of the present invention, the lower-melting continuous phase comprises a linear low density polyethylene polymer of a melt index of greater than 10 (ASTM D1238-89, 190° C.) and a density of less than 0.945 g/cc (ASTMD-792). At least one higher-melting noncontinuous phase comprises a polypropylene polymer with melt flow rate of greater than 20 g/10 min (ASTM D1238-89, 230° C.). [0009] In one of the preferred embodiments of the invention, the lower-melting continuous phase forms at least 80 percent by weight of the fiber and comprises a linear low density polyethylene having a density of 0.90-0.945 g/cc and a melt index of greater than 25 g/10 minutes. [0010] In another preferred embodiment, said lower-melting polymer phase comprises linear low density polyethylene as described above and said higher-melting polymer phase comprises an isotactic polypropylene with a melt flow rate greater than 30 g/10 minutes. [0011] In still another preferred embodiment said lower-melting polymer phase comprises at least 80 percent by weight low pressure, solution process, linear short chain branched polyethylene with a melt index of greater than 30 and a density of 0.945 g/cc and said higher-melting polymer phase comprises 1 to 20 percent by weight of isotactic polypropylene. [0012] In another embodiment of the invention, said lower-melting polymer phase comprises linear low density polyethylene with a melt index of 27 and said higher-melting polymer phase comprises an isotactic polypropylene with a melt flow rate of 35 g/10 minutes. [0013] According to another aspect of the present invention, the lower-melting dominant continuous phase is blended with a higher-melting noncontinuous phase of propylene co- and/or ter- polymers. When propylene co- and/or ter-polymers are used as the higher-melting noncontinuous phase, the lower melting continuous phase may be comprised of one or more polyethylenes selected from the group consisting of low density polyethylene, high pressure long chain branched polyethylene, linear low density polyethylene, high density polyethylene and copolymers thereof. BRIEF DESCRIPTION OF THE DRAWINGS [0014] In the drawings which form a portion of the original disclosure of the invention: [0015] [0015]FIG. 1 diagrammatically illustrates one method and apparatus for manufacturing the nonwoven webs according to the invention; [0016] [0016]FIG. 2 is a fragmentary plan view of a nonwoven web of the invention; [0017] [0017]FIG. 3 is a diagrammatical cross-sectional view of a nonwoven fabric laminate in accordance with the invention; and [0018] [0018]FIG. 4 is a diagrammatical cross-sectional view of a laminate of the nonwoven fabric of FIG. 2 with a film. DETAILED DESCRIPTION [0019] Linear low density polyethylene (LLDPE) is produced in either a solution or a fluid bed process. The polymerization is catalytic. Ziegler Natti and single-site metallocene catalyst systems have been used to produce LLDPE. The resulting polymers are characterized by an essentially linear backbone. Density is controlled by the level of comonomer incorporation into the otherwise linear polymer backbone. Various alpha-olefins are typically copolymerized with ethylene in producing LLDPE. The alpha-olefins which preferably have four to eight carbon atoms, are present in the polymer in an amount up to about 10 percent by weight. The most typical comonomers are butene, hexene, 4-methyl-1-pentene, and octene. The comonomer influences the density of the polymer. Density ranges for LLDPE are relatively broad, typically from 0.87-0.95 g/cc (ASTM D-792). [0020] Linear low density polyethylene melt index is also controlled by the introduction of a chain terminator, such as hydrogen or a hydrogen donator. The melt index for a linear low density polyethylene can range broadly from about 0.1 to about 150 g/10 min. For purposes of the present invention, the LLDPE should have a melt index of greater than 10, and preferably 15 or greater for spunbonded filaments. Particularly preferred are LLDPE polymers having a density of 0.90 to 0.945 g/cc and a melt index of greater than 25. [0021] Examples of suitable commercially available linear low density polyethylene polymers include the linear low density polyethylene polymers available from Dow Chemical Company, such as the ASPUN series of Fibergrade resins, Dow LLDPE 2500 (55 MI, 0.923 density), Dow LLDPE Type 6808A (36 MI, 0.940 density), and the Exact series of linear low density polyethylene polymers from Exxon Chemical Company, such as Exact 2003 (31 MI, density 0.921). [0022] The higher-melting polypropylene component can be an isotactic or syndiotactic polypropylene homopolymer, or can be a copolymer or terpolymer of propylene. The melt flow rate of the polypropylene should be greater than 20 g/10 min., and preferably 25 or greater. Particularly suitable are polypropylene polymers having an MFR of 35 to 65. Examples of commercially available polypropylene polymers which can be used in the present invention include SOLTEX Type 3907 (35 MFR, CR grade), HIMONT Grade X10054-12-1 (65 MFR), Exxon Type 3445 (35 MFR), Exxon Type 3635 (35 MFR) AMOCO Type 10-7956F (35 MFR), and Aristech CP 350 J (melt flow rate approximately 35). Examples of commercially available copolymers of propylene include Exxon 9355 which is a random propylene copolymer with 3% ethylene, 35 melt flow rate; and co- and ter-polymers of propylene from the Catalloy™ series from Himont. [0023] The lower-melting polyethylene component and the higher-melting polypropylene component can be present in proportions ranging from 70 percent by weight polyethylene and 30 percent polypropylene to 99 percent by weight polyethylene and 1 percent polypropylene. In these proportions, the lower-melting polyethylene component is present as a substantially continuous phase and the higher-melting polypropylene is present as a discontinuous phase dispersed in the polyethylene phase. [0024] Appropriate combinations of polymers are combined and blended before being melt-spun into fibers or fibrous webs. A high degree of mixing is used in order to prepare blends in which the polypropylene component is highly dispersed in the polyethylene component. In some cases such mixing may be achieved in the extruder as the polymers are converted to the molten state. However, in other cases it may be preferred to use an extra mixing step. Among the commercially available mixers that can be used are the Barmag 3DD three-dimensional dynamic mixer supplied by Barmag AG of West Germany and the RAPRA CTM cavity-transfer mixer supplied by the Rubber and Plastics Research Association of Great Britain. [0025] The blended polymer dispersion is then either melt-spun into fibers, which may be formed into a web for instance by carding, airlaying, or wetlaying, or melt-spun directly into fibrous webs by a spunbonding or meltblowing process. The web can then be bonded to form a strong, soft biconstituent-fiber nonwoven fabric. Webs of the blended polymer dispersion can be made according to any of the known commercial processes for making nonwoven fabrics, including processes that use mechanical, electrical, pneumatic, or hydrodynamic means for assembling fibers into a web, for example carding, wetlaying, carding/ hydroentangling, wetlaying/hydroentangling, and spunbonding. The webs of the blended polymer dispersion can then be bonded by a multiplicity of thermal bonds to give the webs sufficient strength and abrasion resistance to be useful in, for example, diaper applications. Preferably the bonds are thermal bonds formed by heating the fibers so that via a combination of heat and pressure they become tacky and fuse together at point of contact between the fibers. The thermal bonds may be formed using any of the techniques known in the art for forming discrete thermal bonds, such as calendering. Other thermal bonding techniques, such as through-air bonding and the like, may also be used. [0026] [0026]FIG. 1 is a diagrammatical view of an apparatus, indicated generally by the reference number 10 , for producing a spunbonded nonwoven web in accordance with the present invention. Various spunbonding techniques exist, but all typically include the basic steps of extruding continuous filaments, quenching the filaments, drawing or attenuating the filaments by a high velocity fluid, and collecting the filaments on a surface to form a web. The spunbonding apparatus 10 is illustrated as a slotdraw type spunbonding apparatus, although, as will be appreciated by the skilled artisan, other spunbonding apparatus may be used. Spunbonding apparatus 10 includes a melt spinning section including a feed hopper 12 and an extruder 14 for the polymer. The extruder 14 is provided with a generally linear die head or spinneret 16 for melt spinning streams of substantially continuous filaments 18 . The substantially continuous filaments 18 are extruded from the spinneret 16 and typically are quenched by a supply of cooling air 20 . The filaments are directed to an attenuation device 22 , preferably in the form of an elongate slot which includes downwardly moving attenuation air which can be supplied from forced air above the slot, vacuum below the slot, or eductively within the slot, as is known in the art. In the attenuation device 22 , the filaments become entrained in a high velocity stream of attenuation air and are thereby attenuated or drawn. The air and filaments are discharged from the lower end of the attenuation device 22 and the filaments are collected on a forming wire 24 as a nonwoven spunbond web W. [0027] The web W is conveyed to a bonding station 26 to form a coherent bonded nonwoven fabric. In the embodiment shown, the web is thermally bonded using a pair of heated calender rolls 27 and 28 . Thermal bonds are formed by heating the filaments so that they soften and become tacky, and fuse together contacting portions of the filaments. The operating temperature and the compression force of the heated rolls 27 and 28 should be adjusted to a surface temperature and pressure such that the filaments present in nonwoven web soften and bind the fibrous nonwoven web to thereby form a coherent nonwoven fabric. The pattern of the calender rolls may be any of those known in the art, including point bonding patterns, helical bonding patterns, and the like. The term point bonding is used herein to be inclusive of continuous or discontinuous pattern bonding, uniform or random point bonding, or a combination thereof, all as are well known in the art. [0028] Although bonding station 26 has been illustrated in FIG. 1 as heated calender rolls, the rolls can, in other embodiments of the invention, be replaced by other thermal activation zones. For example, the bonding station may be in the form of a through-air bonding oven, a microwave or other RF treatment zone. Other bonding stations, such as ultrasonic welding stations, can also be used in the invention. In addition other bonding techniques known in the art can be used, such as adhesive bonding. [0029] The thermally bonded nonwoven fabric is then wound by conventional means onto roll 29 . The nonwoven fabric can be stored on roll 29 or passed to end use manufacturing processes, for example for use as a component in a disposable personal care article such as diapers and the like, medical fabrics, wipes, and the like. [0030] [0030]FIG. 2 illustrates a thermally bonded spunbonded nonwoven fabric W produced in accordance with the present invention. The nonwoven fabric W may be laminated into structures having a variety of desirable end-use characteristics. FIG. 3 is a diagrammatical cross-sectional view of a nonwoven fabric laminate in accordance with one embodiment of the invention. In this embodiment, the laminate, generally indicated at 40 , is a two-ply laminate. Ply 41 comprises a web which may be a meltblown nonwoven web, a spunbonded web, or a web of staple fibers. Ply 42 comprises a nonwoven web formed of a highly dispersed blend of polyolefin polymers, such as the nonwoven fabric W produced as described above. [0031] The plies may be bonded and/or laminated in any of the ways known in the art. Lamination and/or bonding may be achieved, for example, by hydroentanglement of the fibers, spot bonding, through-air bonding and the like. For example, when ply 41 is a fibrous web, lamination and/or bonding may be achieved by hydroentangling, spot bonding, through-air bonding and the like. In the embodiment shown in FIG. 3, plies 41 and 42 are laminated together by passing through a heated patterned calender to form discrete thermal point bonds indicated at 43 . It is also possible to achieve bonding through the use of an appropriate bonding agent, i.e., an adhesive. The term spot bonding is inclusive of continuous or discontinuous pattern bonding, uniform or random point bonding or a combination thereof, all as are well known in the art. [0032] The bonding may be made after assembly of the laminate so as to join all of the plies or it may be used to join only selected of the fabric plies prior to the final assembly of the laminate. Various plies can be bonded by different bonding agents in different bonding patterns. Overall, laminate bonding can also be used in conjunction with individual layer bonding. [0033] Laminates of a spunbond web from the highly blended polymer dispersion as described above with a web of meltblown microfibers have utility as barrier fabrics in medical applications, protective clothing applications, and for hygiene applications such as barrier leg cuffs. Of particular utility for hygiene applications are spunbond/meltblown laminates of reduced basis weight, such as made with a 17 grams per square meter (gsm) spunbonded web of this invention and 2-3 gsm meltblown web. Such barrier laminates could be used, for example, as barrier leg cuffs in diapers. [0034] Another type of nonwoven fabric laminate may be made by combining nonwoven web of this invention with a film, for example a film of a thermoplastic polymer, such as a polyolefin, to make barrier fabrics useful for hygiene applications such as barrier leg cuffs and diaper backsheets. FIG. 4 illustrates one such laminate, which includes a ply or layer 42 ′ comprising a nonwoven web formed of a highly dispersed blend of polyolefin polymers, such as the nonwoven fabric W of FIG. 2, laminated to a polyolefin film layer 44 , such as for example a polyethylene film of a thickness of 0.8 to 1 mil. Lamination and/or bonding of the nonwoven layer 42 ′ to the film layer 44 can be achieved by adhesive lamination using a continuous or discontinuous layer of adhesive. This adhesive approach may yield a diaper backsheet with superior softness and hand. The nonwoven fabric laminate could also be produced by thermal lamination of the nonwoven fabric of this invention and film webs together. This approach has the advantage of eliminating the cost of the adhesive. It may also be desirable to utilize coextruded film webs that include a sealing/bonding layer in combination with a polyolefin layer in the film web that, when combined with the nonwoven fabrics of the invention, maximize softness and good thermal bonding characteristics. The nonwoven fabric laminate could also be produced by direct extrusion of the film layer 44 on ply 42 ′. EXAMPLE 1 [0035] Ninety percent by weight of a linear low density polyethylene (LLDPE) with a melt flow of 27 (Dow 6811 LLDPE) and ten percent by weight of a polypropylene (PP) polymer with a melt flow approximately 35 (Aristech CP 350 J) were dry blended in a rotary mixer. The dry-blended mixture was then introduced to the feed hopper of an extruder of a spunbond nonwoven spinning system. Continuous filaments were meltspun by a slot draw process at a filament speed of approximately 600 m/min and deposited upon a collection surface to form a spunbond nonwoven web, and the web was thermally bonded using a patterned roll with 12% bond area. For comparison purposes, nonwoven spunbond fabrics were produced under similar conditions with the same polymers, using 100% PP and 100% LLDPE. [0036] As shown in table 1, the 100% LLDPE spunbond samples exhibited superior softness (75 and 77.5) compared to the 100% polypropylene spunbond sample ( 30 ). However, the abrasion resistance of the 100% LLDPE sample, as seen from the fuzz measurement, was relatively high (12.5 and 2.4) compared to the 100% PP sample (0.3). The nonwoven fabric formed from the 90% LLDPE/10% PP blend had a high softness (67.5) only slightly less than the 100% LLDPE fabric, and had abrasion resistance (fuzz value) of 1.0 mg., which is significantly better than the values seen for 100% LLDPE. The blend sample also showed improved CD tensile compared to products made with 100% LLDPE. TABLE 1 Sample A B C D C = comparison I = invention C C C I Composition: % polypropylene 100  0  0  10 % polyethylene  0 100 100  90 filament dia. (microns) 17.5 20.9 20.9 22.5 Basis weight (gsm) 1 23.1 25.2 24.6 24.8 Loft @ 95 g/in 2 (mils) 2  9.8  9.0  7.8  9.3 Fuzz (mg) 3  0.3 12.5  2.4  1.0 Softness 4  30 75 77.5 67.5 Strip Tensile (g/cm) 5 CD 557 139 157 164 MD 1626  757 639 467 Peak Elongation (%) CD 90 116 129 108 MD 93 142 106 119 TEA (in. g./in CD 852 297 346 354 MD 2772  2222  1555  1389  #TEA, Total Tensile Energy Absorption, is calculated from the area under the stress-strain curve generated during the Strip Tensile test. EXAMPLE 2 [0037] (Control) [0038] A control fiber was made by introducing 100% Dow LLDPE 2500 (55 MI, 0.923 density) to a feed hopper of a spinning system equipped with an extruder, a gear pump to control polymer flow at 0.75 gram per minute per hole, and a spinneret with 34 holes of L/D=4:1 and a diameter of 0.2 mm. Spinning was carried out using a melt temperature in the extruder of 215° C. and a pack melt temperature of 232° C. After air quench, the resulting filaments were drawn down at a filament speed of approximately 1985 m/min using an air aspiration gun operating at 100 psig to yield a denier of 3.01 and denier standard deviation of 0.41. EXAMPLE 3 [0039] Ninety parts by weight of Dow LLDPE Type 2500 (55 MI, 0.923 density) and ten parts of Himont X10054-12-1 polypropylene (65 MFR) were dry blended in a rotary mixer and then introduced to the feed hopper of the spinning system described in Example 2. Spinning was carried out using a pack melt temperature of 211° C. After air quench, the resulting filaments were drawn down at a filament speed of approximately 2280 M/Min using an air aspiration gun operating at 100 psig to yield a denier of 2.96 and a denier standard deviation of 1.37. EXAMPLE 4 [0040] Ninety parts by weight of Dow LLDPE Type 2500 (55 MI, 0.923 density) and ten parts of Soltex 3907 polypropylene (35 MFR, 1.74 die swell, CR grade) were dry blended in a rotary mixer and then introduced to the feed hopper of the spinning system described in Example 2. Spinning was carried out using a pack melt temperature of 231° C. and an extruder melt temperature of 216° C. After air quench, the resulting filaments were drawn down at a filament speed of approximately 2557 M/Min using an air aspiration gun operating at 100 psig to yield a denier of 2.64 and a denier standard deviation of 0.38. EXAMPLE 5 [0041] Ninety parts by weight of Dow LLDPE Type 6808A (36 MI, 0.940 density) and ten parts of Soltex 3907 polypropylene (35 MFR, 1.74 die swell, CR grade) were dry blended in a rotary mixer and then introduced to the feed hopper of the spinning system described in Example 2. Spinning was carried out using a pack melt temperature of 231° C. and an extruder melt temperature of 216° C. After air quench, the resulting filaments were drawn down at a filament speed of approximately 2129 M/Min using an air aspiration gun operating at 100 psig to yield a denier of 3.17 and a denier standard deviation of 2.22. [0042] The quality of spinning for a given formulation has been found to roughly correlate with the denier standard deviation. A reduced standard deviation suggests more stable or higher quality spinning. Thus it is unexpected and contrary to the teaching of the prior art that the blend using a 35 MFR polypropylene in Example 4 yielded a more stable spinning than seen with the corresponding LLDPE control in Example 2. EXAMPLE 6 [0043] Eighty parts by weight of a linear low density polyethylene pellets of 55 melt index and 0.925 g/cc density and twenty parts by weight polypropylene pellets of 35 melt flow rate were dry blended in a rotary mixer. The dry-blended mixture was then introduced to the feed hopper of a spinning system equipped with an extruder with a 30:1 l/d ratio, a static mixer, and a gear pump for feeding the molten polymer to a heated melt block fitted with a spinneret. Filaments were extruded from the spinneret and drawn using air aspiration. EXAMPLE 7 [0044] Samples of continuous filament spunbonded nonwoven webs were produced from blends of a linear low density polyethylene with a melt flow rate of 27 (Dow 6811A LLDPE) and a polypropylene homopolymer (Appryl 3250YR1, 27 MFR) in various blend proportions. Control fabrics of 100 percent polypropylene and 100 percent polyethylene were also produced under similar conditions. The fabrics were produced by melt spinning continuous filaments of the various polymers or polymer blends, attenuating the filaments pneumatically by a slot draw process, depositing the filaments on a collection surface to form webs, and thermally bonding the webs using a patterned calender roll with a 12 percent bond area. The fabrics had a basis weight of approximately 25 gsm and the filaments had an average mass/length of 3 dtex. The tensile strength and elongation properties of these fabrics and their abrasion resistance were measured, and these properties are listed in Table 2. As shown, the 100 percent polypropylene control fabric had excellent abrasion resistance, as indicated by no measurable fuzz generation; however the fabrics had relatively low elongation. The 100 percent polyethylene control fabric exhibited good elongation properties, but very poor abrasion resistance (high fuzz values and low Taber abrasion resistance) and relatively low tensile strength. Surprisingly, the fabrics of the invention made of blends of polypropylene and polyethylene exhibited an excellent combination of abrasion resistance, high elongation, and good tensile strength. It is noted that the CD elongation values of the blends actually exceeded that of the 100% polyethylene control. This surprising increase in elongation is believed to be attributable to the better bonding of the filaments of the blend as compared to the bonding achieved in the 100% polyethylene control, which resulted in the fabrics of the invention making good use of the highly elongatable filaments without bond failure. TABLE 2 MECHANICAL PROPERTIES OF POLYPROPYLENE (PP)/POLYETHYLENE (PE) BLEND FABRICS 25/75 15/85 Fabric 100% PP PP/PE PP/PE 100% PE MD Tensile (g/cm) 6 925 764 676 296 CD Tensile (g/cm) 6 405 273 277  63 MD Elongation (%) 6  62 170 199 168 CD Elongation (%) 6  70 190 224 131 Fuzz (mg) 7 0.0 0.3 0.5 19.0 Taber Abrasion 8  40  32  22  10 (cycles - rubber wheel) Taber Abrasion 8 733 200 500  15 (cycles - felt wheel)

Nonwoven fabrics and fabric laminates are formed from continuous filaments or staple fibers of a select blend of specific grades of polyethylene and polypropylene which give improved fabric performance not heretofore recognized or described, such as high abrasion resistance, good tensile properties, excellent softness and the like. Furthermore, these blends have excellent melt spinning and processing properties which permit efficiently producing nonwoven fabrics at high productivity levels. The polymers are present as a lower-melting dominant continuous phase and at least one higher-melting noncontinuous phase dispersed therein. The lower-melting continuous phase forms at least 70 percent by weight of the fiber and comprises a linear low density polyethylene polymer of a melt index of greater than 10 and a density of less than 0.945 g/cc. At least one higher-melting noncontinuous phase comprises a polypropylene polymer with melt flow rate of greater than 20 g/10 min.

CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/281,399 tiled on Jan. 21, 2016, the entire contents of which are incorporated herein by reference. FIELD [0002] The invention relates to tools and methods for pulling a utility line through a borehole. SUMMARY [0003] An assembly is formed from a bit and a connector. The bit has a body and a plurality of hardened cutting elements supported on the body. The body has an internal passage extending therethrough. The connector extends through the passage. The connector is formed from a first member and a second member. The first member has an elongate neck and an enlarged head formed at one end of the neck. The second member is pivotally connected to the neck. [0004] A kit is formed from a bit, a first connector element, and a second connector element. The bit has a body and a plurality of hardened cutting elements supported on the body. The body has an internal passage extending therethrough. The first connector element has an elongate neck and an enlarged head formed at one end of the neck. The elongate neck is sized to be closely received within the passage, The second connector element is configured for pivotal connection to the neck. BRIEF DESCRIPTION OF THE DRAWINGS [0005] FIG. 1 is a perspective view of a pullback adapter formed from a shackle pivotally connected to a connector member. [0006] FIG. 2 is a side elevation view of the connector member of FIG. 1 . [0007] FIG. 3 is a perspective view of the connector member of FIG. 1 . [0008] FIG. 4 is a perspective view of a bit. [0009] FIG. 5 is an exploded view of a pullback assembly formed from the pullback adapter of FIG. 1 attached to the bit of FIG. 4 . [0010] FIG. 6 is a perspective view of the pullback assembly of FIG. 5 in which an upper side of the bit is shown. [0011] FIG. 7 is a perspective view of the pullback assembly of FIG. 5 in which a lower side of the bit is shown. [0012] FIG. 8 is a side elevation view of the pullback assembly with an alternate bit. [0013] FIG. 9 is a side elevation view of a beacon connected to the pullback assembly of FIG. 8 . [0014] FIG. 10 is a perspective view of the beacon and assembly of FIG. 9 . [0015] FIG. 11 is a front elevation view of the pullback assembly of FIG. 5 . [0016] FIG. 12 is a system for pulling a utility line through a borehole using the pullback adapter, bit, and beacon shown in FIG. 9 . [0017] FIG. 13 is an enlarged view of a portion of the system of FIG. 12 , showing the connection between the utility line and the pullback adapter. DETAILED DESCRIPTION [0018] Shown in FIG. 12 is a system 10 for pulling a utility line 12 through a borehole 14 . The system 10 comprises a drilling rig 16 , a drill string 18 , a beacon 20 , a bit 22 , a pullback adapter 24 , and the utility line 12 . The utility line 12 may be a pipe, a cable, or any structure suitable for pulling through a borehole. Prior to installation, the utility line 12 may be stored on a spool 26 . [0019] The drill string 18 begins drilling the borehole 14 at a surface entrance point 28 and follows a path underground to a surface exit point 30 . At the exit point 30 the pullback adapter 24 is connected to the bit 22 and the utility line 12 . The drilling rig 16 pulls the drill string 18 back through the borehole 14 . Since the pullback adapter 24 connects the utility line 12 to the drill string 18 , the utility line 12 is pulled through the borehole 14 as the drill string 18 is retracted by the drilling rig 16 . [0020] With reference to FIGS. 1-3 , the pullback adapter 24 comprises a first connector member 32 . The first connector member 32 is formed from a strong and durable material, such as steel. The first connector member 32 has an elongate neck 34 and an enlarged head 36 . [0021] The elongate neck 34 has opposed first and second ends 38 , 40 . A passage 42 is formed in the first end 38 of the elongate neck 34 opposite the enlarged head 36 . The first end 38 of the elongate neck 34 may terminate in a free end 44 that is curved, as shown in FIGS. 1-3 . In another embodiment, the elongate neck 34 may terminate in a free end 44 having a planar surface. In the embodiment of FIGS. 1-3 , the elongate neck 34 has the shape of a rectangular prism. However, in another embodiment the elongate neck 34 may have the shape of prism formed from a non-rectangular polygonal base, such as a triagonal prism, a pentagonal prism, or a hexagonal prism. In yet another embodiment, the elongate neck 34 may have the shape of a cylinder or a shape formed from a partial cylindrical base, such as a semicylinder. [0022] The enlarged head 36 is formed at the second end 40 of the elongate neck 34 . The enlarged head 36 has at least one flanged portion projecting radially outward from the elongate neck 34 . At the flanged portion, the enlarged head 36 has a width larger than the width of the elongate neck 34 . In the embodiment of FIGS. 1-3 , the enlarged head 36 has a top surface 46 having the shape of a convex curve. However, the top surface 46 of the enlarged head 36 may have a shape that is flat or concave. [0023] The pullback adapter 24 further comprises a second connector member attached to the first connector member 32 . The second connector member is formed from a strong and durable material, such as steel. The second connector member may attach to the first connector member 32 through the passage 42 formed in the first end 38 of the first connector member 32 . Preferably, the second connecter member is pivotally connected to the first connector member [0024] As shown in FIGS. 1 and 5 , the second connector member is a shackle 50 comprising a link 52 and a bolt 54 . The link 52 has two arms 56 each having an opening 58 . Preferably, the arms 56 are internally threaded within the openings 58 . [0025] Continuing with FIGS. 1 and 5 , the bolt 54 has a shaft 60 and a head 62 . The shaft 60 is sized to be received within the openings 58 of the arms 56 . Preferably, the shaft 60 has a threaded portion 64 complementary to the arms' internal threads so that the bolt 54 may be threaded onto the link 52 . Also preferably, the head 62 has a plurality of flat gripping surfaces 66 to facilitate threading the bolt 54 onto the link 52 . The gripping surfaces 66 facilitate threading by providing purchase for a hand or tool that will rotate the bolt 54 . The shackle 50 is assembled by passing the bolt 54 through the openings 58 of the arms 56 . The assembled shackle 50 has an aperture 68 defined by the space enclosed by the link 52 and the bolt 54 . [0026] Referring to FIGS. 4-8 , the bit 22 is formed from a strong and durable material, such as steel. The bit 22 has an elongate body 70 having an upper side 72 and a lower side 74 . The bit 22 is characterized by a plurality of recessed areas 76 formed in the bit body 70 . The body 70 is formed from a first leg 78 and a second leg 80 . The first leg 78 has an upper surface 82 , a lower surface 84 , and a pair of tapering side surfaces 86 . Preferably, the tapering side surfaces 86 converge to a point 88 at the first leg's free end. The second leg 80 has an upper surface 90 and a lower surface 92 . [0027] The first leg 78 and the second leg 80 join at a bend 94 . The bend 94 creates a steering face so that the drilling direction can be changed. As shown in FIGS. 7 and 8 , on the bit's lower side 74 , the first leg 78 bends away from the second leg 80 . The lower surface 84 of the first leg 78 and the lower surface 92 of the second leg 80 form an included angle θ measuring greater than 180 degrees and less than 220 degrees. Preferably, the included angle θ is 190 degrees. [0028] With reference to FIGS. 4, 6 and 7 , a plurality of passages 96 are formed in the body 70 and extend between the bit's upper and lower sides 72 , 74 . Preferably, the passages 96 are formed in both the first leg 78 and the second leg 80 of the bit body 70 . As best shown in FIGS. 4 and 5 , at least one of the passages 96 is a first leg passage 98 that is sized to closely receive the elongate neck 34 of the first connector member 32 . The shape of the first leg passage 98 may be circular, or it may be complementary to the shape of the elongate neck 34 . In the embodiment of FIG. 4 , the first leg passage 98 has an oblong shape and is sized to closely receive the elongate neck 34 characterized by the shape of a rectangular prism. [0029] Sizing the first leg passage 98 to closely receive the elongate neck 34 prevents the enlarged head 36 from entering the passage 98 . Moreover, the tight fit between the passage 98 and the neck 34 combined with the oblong shape of the passage 98 prevents rotation of the rectangular neck 34 within the passage 98 . Were the neck 34 permitted to rotate, the shackle 50 that it carries could move away from a centered position and toward the walls of the borehole 14 . The shackle 50 and the utility line 12 could become mired in the borehole walls as a result. [0030] Referring to FIGS. 4-8 , the bit 22 further comprises a plurality of hardened cutting elements 100 supported on the body 70 . The cutting elements 100 are formed from a strong and durable material, such as diamond or carbide. Preferably, the cutting elements 100 are polycarbonate diamond compact (PDC) cutters. The cutting elements 100 may be situated in the recessed areas 76 of the bit body 70 . Preferably, the cutting elements 100 are positioned on both the first and second legs 78 , 80 of the bit body 70 . [0031] As best shown in FIG. 5 , a pullback assembly 102 is assembled by passing the elongate neck 34 of the first connector member 32 through the first leg passage 98 of the bit body 70 . The shackle 50 is positioned so that the openings 58 in the arms 56 overlay the passage 42 in the elongate neck 34 . The bolt 54 is passed through the openings 58 and the passage 42 . Preferably, the shackle 50 is pivotally connected to the neck 34 . Also preferably, the bolt 54 is threaded onto the link 52 . However, the bolt 54 may be attached to the link 52 using any suitable fastener, such as a nut or a pin. [0032] Shown in FIGS. 6-8 is the assembled pullback assembly 102 comprising the pullback adapter 24 attached to the bit 22 . Preferably, the pullback adapter 24 is attached to the first leg 78 of the bit body 70 . Also preferably, the enlarged head 36 of the first connector member 32 is situated on the upper side 72 of the bit body 70 , and the shackle 50 is situated on the lower side 74 of the bit body 70 . By situating the shackle 50 on the lower side 74 of the bit body's first leg 78 , the shackle 50 is located on the side of the bit 22 that faces toward the surface exit point 30 , which is the point from which the utility line 12 is pulled. Such configuration allows the shackle 50 and the utility line 12 to be biased toward the center of the borehole 14 during the pulling process. Such centering is advantageous because a centered shackle 50 and utility line 12 are less likely to become caught or mired within the borehole walls during the pulling process. [0033] In FIGS. 9, 10, and 12 , the pullback assembly 102 is shown attached to the beacon 20 . The beacon 20 is carried by the drill string 18 so that the position of a downhole drilling tool can be monitored and adjusted. The beacon 20 is configured to transmit a low frequency dipole magnetic field, which can be detected by an above ground tracker. A tracker operator follows above the beacon 20 and transmits steering information back to a drill rig operator. [0034] With reference to FIGS. 6 and 9-12 , the beacon 20 has a housing 104 having an outer circumference 106 and opposed first and second ends 108 , 110 . The beacon's first end 108 is threaded onto the drill string 18 . The beacon's second end 110 is connected to the bit body 70 . The beacon 20 may be fastened to the bit body 70 by a plurality of fasteners passing through the plurality of passages 96 formed in the bit body's second leg 80 . The bit body 70 may be positioned in oblique relationship to the longitudinal axis of the beacon 20 . [0035] FIG. 13 shows an enlarged view of the beacon 20 , pullback assembly 102 , and utility line 12 of FIG. 12 positioned with respect to a pulling axis 112 of the drill string 18 . The pulling axis 112 is collinear with the force applied to the shackle 50 during the process of pulling the utility line 12 through the borehole 14 . An included angle a is formed between the pulling axis 112 and the second leg 80 . The bit body 70 may be positioned on the beacon 20 such that the included angle α is greater than 0 degrees and less than 25 degrees. Preferably, the included angle a is between about 8 and about 10 degrees. [0036] Continuing with FIG. 13 , an included angle β is formed between the pulling axis 112 and the bit body's first leg 78 . The bit body 70 may be positioned so that the included angle β is greater than 0 degrees and less than 25 degrees. Preferably, the included angle is between about 18 and about 20 degrees. [0037] With reference to FIGS. 6, 11, and 13 , the shackle 50 is situated in the borehole 14 in collinear relationship with the pulling axis 112 . The aperture 68 of the shackle 50 opens perpendicular to the pulling axis 112 . A coupler 114 may be passed through the shackle's aperture 68 in order to connect the utility line 12 to the pullback adapter 24 . The coupler 114 may be a shackle, a pulling grip, a pulling clevis, or any suitable pulling tool, such as a puller having a threaded portion configured for connection to the utility line. The coupler 114 may comprise a swivel. [0038] FIGS. 11 and 13 shows the position of the shackle 50 relative to the borehole 14 and the beacon 20 . The borehole 14 has a circumference 118 defined by the outermost reach of the bit's cutting elements 100 . Because of the position of the bit body 70 relative to the beacon 20 , the beacon's outer circumference 106 is not centered within the borehole's circumference 118 . By situating the shackle 50 on the lower side 74 of the bit body 70 , the shackle 50 is biased toward the center of the borehole 14 , even though the beacon 20 is not centered within the borehole 14 . [0039] Shown in FIGS. 12 and 13 is the system 10 for pulling the utility line 12 through the borehole 14 in which the shackle 50 is positioned on the pulling axis 112 . The pullback adapter 24 is connected to the bit 22 , which is carried by the drill string 18 . The pullback adapter 24 is also connected to the utility tine 12 . As the drill string 18 is retracted, the utility line 12 is pulled through the borehole 14 . Since the shackle 50 is centered on the pulling axis 112 , the attached utility tine 12 is also biased to the pulling axis 112 . [0040] Changes may be made in the construction, operation and arrangement of the various parts, elements, steps and procedures described herein without departing from the spirit and scope of the invention as described in the following claims.

A drill string with a bit at one end is used to dig an underground borehole. When the drill string exits the borehole at a surface exit point, a pullback adapter is used to interconnect the bit with an above-ground utility line. A drilling rig retracts the drill string from the borehole. As the drill string is pulled back through the borehole, the trailing utility line follows along its underground path. As the utility line is pulled through the borehole, the connector biases the utility line to the center of the borehole. Such biasing reduces the risk of ensnaring of the connector and utility line by the borehole walls during the pulling process.

FIELD OF THE INVENTION This invention relates to the field of portable paint spraying equipment, more particularly to equipment suitable for spraying lines on parking lots and the like. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a left-side elevation view of a portable paint spraying apparatus in a non-line-striping configuration. FIG. 2 is a left-side elevation view of the portable paint sprayer apparatus of FIG. 1 coupled to a line sprayer accessory and arranged in a line-striping configuration. FIG. 3 is a simplified top plan view of a portion of the cart of FIG. 1. FIG. 4 is a perspective view of the line striper accessory suitable for use with the paint sprayer of FIG. 1. FIG. 5 is a top plan view of the line striper accessory. FIG. 6 is a bottom plan view of the line striper accessory. FIG. 7 is a right-hand side elevation view of the line striper accessory. FIG. 8 is a rear elevation view of the line striper accessory with spray gun attached for line striping duty. FIG. 9 is a front elevation view of the line striper accessory of FIG. 8. FIG. 10 is a detailed view of a locking mechanism for the castor assembly of the present invention. FIG. 11 is a fragmentary section view taken along 11--11 of FIG. 10. FIG. 12 is a detailed view of the paint gun clamp and actuator seen from below. DETAILED DESCRIPTION Referring now to the figures, and most particularly to FIG. 1, a portable paint sprayer 10 may be seen. Sprayer 10 preferably includes a cart 12, having a pair of wheels 14 spaced apart (see FIG. 3). Wheels 14 are preferably carried by an axle 16. In a conventional painting configuration such as shown in FIG. 1, cart 12 also rests on a pair of legs 18. In this configuration, a spray gun 20 is supplied with paint via hose 22, but is otherwise unrestrained so as to permit operator to grasp gun 20 and move it to apply paint as desired. In the configuration shown in FIG. 1, paint is drawn from a bucket 24 via a paint pump intake 26. Referring now also to FIG. 3, cart 12 preferably also has a transverse support 28 extending parallel to axle 16. Referring now most particularly to FIGS. 2 and 4, a line striper accessory 30 may be seen. Line striper 30 preferably includes an elongated support frame 32 having a first end 34 and a second end 36. Accessory 30 also has a castor assembly 38 located at the first end 34 of frame 32. Castor assembly has a vertical castor axis 40 about which castor assembly 38 may swivel. Assembly 38 has at least one and preferably two wheels 42 mounted in a yoke 44. Wheels 42 preferably have a horizontal axle 46. The line striper 30 also preferably has a locking mechanism 48 (see FIGS. 10 and 11) which is operable to a first position (as shown in FIGS. 10 and 11) to prevent swiveling the castor assembly when the castor wheel axle 46 is transverse to frame 32. Locking mechanism 48 is movable to alternate locking positions to position the castor assembly 38 to provide a fixed turning radius for the line striper 30. In the first position, a spring biased releasable pin 50 located on frame 32 is engageable with one of a plurality of apertures 52 in yoke 44. In the second position of locking mechanism 48, pin 50 is retracted or disengaged from yoke 44. Pin 50 is actuated by a flexible cable 54 connected to a hand grip actuator for selectively activating the locking mechanism 48. Line or paint striper 30 also preferably has handlebars 58, 60 which include hand grips 62, 64. It is to be understood that handlebars 58, 60 extend from frame 32 to grips 62, 64 to permit an operator to grasp and propel the line striper 30. Line striper 30 also has cart securing means positioned along the frame 32 for securing the cart 12 to the frame such that the combined cart and frame (as shown in FIG. 2) is supported by wheels 14 of the cart 12 and the castor assembly 38. In particular, the cart securing means includes a first supporting means in the form of a V-shaped channel 66. Channel 66 supports transverse member 28 of cart 12 on frame 32 proximate the second end 36 of frame 32. The cart securing means also includes a second supporting means for supporting the frame 32 on the cart 12 (more particularly on axle 16) intermediate the first and second ends 34, 36 of frame 32. A pair of U-clamps 68 may be received around axle 16 and secured to slots 70 in frame 32. Line striper accessory 30 also preferably has a receptacle portion 72 adapted to hold paint bucket 24. Receptacle 72 is made up of a transverse base plate 74 and a surrounding frame 76. Line striper 30 also preferably includes a spray gun mounting apparatus 80 as is shown most clearly in FIGS. 4 and 12. Apparatus 80 includes a first tubular extension 82 which may be secured to frame 32 via a thumb screw 84. A right angle clamp 86 joins a second extension 88 to first extension 82. A gun mounting block 90 is preferably mounted to second extension 88 and secured thereto via a thumb screw 92. A further thumb screw 94 may be used to clamp gun 20 in block 90. A transverse projecting finger 96 engages a trigger 98 in gun 20 when gun 20 is mounted in block 90. Finger 96 is biased to the position shown in FIG. 12 via a pair of springs 100, 102 and is selectively capable of being retracted towards block 90 via flexible cable 104. As may be seen most clearly in FIG. 4, cable 104 is actuatable via a handlebar actuator 106 when it is desired to stripe paint by actuating gun 20. Referring now again to FIG. 2, it may be seen that an extended suction set 110 may be used to draw paint from bucket 24 when the combination of sprayer 10 and accessory 30 is configured for line striping. This permits a close approach to a curb 112 which would not be possible with the paint bucket 24 in the configuration shown in FIG. 1, even though such configuration would be possible for striping because bucket 24 is supported by bail 114 on hook 116 when the sprayer 10 is elevated as shown in FIG. 2. In other words, if it is not required to have a close approach to curb 112, direct suction of paint may be utilized, as indicated in FIG. 1, even while sprayer 10 is configured on striper 30 as shown in FIG. 2. It is also to be understood that additional spray guns may be mounted on apparatus 80 to spray parallel lines or, alternatively, one or more additional spray guns may be mounted on a second apparatus (not shown) which would extend from alternate extension 118 (see FIG. 4) which is secured by thumb screw 120. In FIG. 4, extension 118 is shown in a storage position or configuration. It is also to be understood that it is preferable, although not necessary, to rotate handle 122 of sprayer 10 from the position shown in FIG. 1 to that of FIG. 2 to permit ready access to the receptacle portion 72 when it is desired to insert a bucket, add paint or solvent, or remove bucket 24. The invention is not to be taken as limited to all of the details thereof as modifications and variations thereof may be made without departing from the spirit or scope of the invention.

A line striper accessory for combining with a conventional paint sprayer mounted on a wheeled cart utilizing the cart wheels and a castor assembly to support the combined cart and line striping accessory. The accessory includes handlebars having actuators to selectively actuate a locking mechanism and the spray gun mounted on the accessory for providing paint stripes on the surface over which the striper is rolled.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims benefit to U.S. Provisional Application Ser. No. 60/316,276, filed on Sep. 4, 2001, and to German Patent Application Ser. No. 101 39 062.9, filed on Aug. 9, 2001, both of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a process for the fermentative preparation of L-amino acids, in particular L-lysine and L-glutamic acid, using coryneform bacteria in which one or more genes chosen from the group consisting of the otsB gene, treY gene and treZ gene are attenuated. [0004] 2. Description of the Background [0005] L-Amino acids, in particular L-lysine and L-glutamic acid, are used in human medicine and in the pharmaceuticals industry, in the foodstuffs industry and very particularly in animal nutrition. [0006] It is known that amino acids are prepared by fermentation from strains of coryneform bacteria, in particular Corynebacterium glutamicum. Because of their great importance, work is constantly being undertaken to improve the preparation processes. Improvements to the process can relate to fermentation measures, such as, for example, stirring and supply of oxygen, or the composition of the nutrient media, such as, for example, the sugar concentration during the fermentation, or the working up to the product form by, for example, ion exchange chromatography, or the intrinsic output properties of the microorganism itself. [0007] Methods of mutagenesis, selection and mutant selection are used to improve the output properties of these microorganisms. Strains which are resistant to antimetabolites, such as, for example, the lysine analogue S-(2-aminoethyl)-cysteine, or are auxotrophic for metabolites of regulatory importance and produce L-amino acids are obtained in this manner. [0008] Methods of the recombinant DNA technique have also been employed for some years for improving the strain of Corynebacterium glutamicum strains which produce L-amino acids, by amplifying individual amino acid biosynthesis genes and investigating the effect on the L-amino acid production. SUMMARY OF THE INVENTION [0009] The inventors had the object of providing new fundamentals for improved processes for the fermentative preparation of L-amino acids, in particular L-lysine and L-glutamic acid, with coryneform bacteria. [0010] It is another object of the invention to provide nucleotide sequences which may be used to accomplish this object. [0011] The objects of the invention may be accomplished with an isolated polynucleotide from coryneform bacteria, containing a polynucleotide sequence which codes for trehalose phosphatase and/or a polynucleotide sequence which codes for maltooligosyl-trehalose synthase and/or a polynucleotide sequence which codes for maltooligosyl-trehalose trehalohydrolase, wherein each sequence is lengthened by approximately 600 base pairs before the start codon and after the stop codon. [0012] The invention provides also a process for the fermentative preparation of L-amino acids using coryneform bacteria in which at least the nucleotide sequence which codes for trehalose phosphatase and/or the nucleotide sequence which codes for maltooligosyl-trehalose synthase and/or the nucleotide sequence which codes for maltooligosyl-trehalose trehalohydrolase is or are attenuated, in particular eliminated or expressed at a low level. [0013] The present invention also provides a process for the fermentative preparation of L-amino acids, in which the following steps are carried out: (a) fermentation of the L-amino acid-producing coryneform bacteria in which at least the nucleotide sequence which codes for trehalose phosphatase and/or the nucleotide sequence which codes for maltooligosyl-trehalose synthase and/or the nucleotide sequence which codes for maltooligosyl-trehalose trehalohydrolase is or are attenuated, in particular eliminated or expressed at a low level; (b) concentration of the L-amino acids in the medium or in the cells of the bacteria; and (c) isolation of the desired L-amino acids, constituents of the fermentation broth and/or the biomass optionally remaining in portions or in their total amounts in the end product. [0017] A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following Figures in conjunction with the detailed description below. BRIEF DESCRIPTION OF THE FIGURES [0018] FIG. 1 : Map of the plasmid pCR2.1otsBint, [0019] FIG. 2 : Map of the plasmid pCR2.1treYint, [0020] FIG. 3 : Map of the plasmid pCR2.1treZint. [0021] The abbreviations and designations used have the following meaning. [0022] KmR: Kanamycin resistance gene [0023] BamHI: Cleavage site of the restriction enzyme KpnI [0024] EcoRI: Cleavage site of the restriction enzyme EcoRI [0025] EcoRV: Cleavage site of the restriction enzyme EcoRV [0026] PstI: Cleavage site of the restriction enzyme PstI [0027] SalI: Cleavage site of the restriction enzyme SalI [0028] otsBint: Internal fragment of the otsB gene [0029] treYint: Internal fragment of the treY gene [0030] treZint: Internal fragment of the treZ gene [0031] ColE1: Replication origin of the plasmid ColE1 DETAILED DESCRIPTION OF THE INVENTION [0032] Where L-amino acids or amino acids are mentioned in the following, this means one or more amino acids, including their salts, chosen from the group consisting of L-asparagine, L-threonine, L-serine, L-glutamic acid, L-glycine, L-alanine, L-cysteine, L-valine, L-methionine, L-isoleucine, L-leucine, L-tyrosine, L-phenylalanine, L-histidine, L-lysine, L-tryptophan and L-arginine. L-Lysine and L-glutamic acid are particularly preferred. [0033] When L-lysine or lysine are mentioned in the following, not only the bases but also the salts, such as e.g. lysine monohydrochloride or lysine sulfate, are meant by this. [0034] When L-glutamic acid or glutamic acid are mentioned in the following, the salts, such as e.g. glutamic acid hydrochloride or glutamic acid sulfate are also meant by this. [0035] The strains employed preferably already produce L-amino acids, in particular L-lysine and L-glutamic acid, before the attenuation of the otsB gene, which codes for trehalose phosphatase, and/or the treY gene, which codes for maltooligosyl-trehalose synthase, and/or the treZ gene, which codes for maltooligosyl-trehalose trehalohydrolase. [0036] The term “attenuation” in this connection describes the reduction or elimination of the intracellular activity of one or more enzymes (proteins) in a microorganism which are coded by the corresponding DNA, for example by using a weak promoter or using a gene or allele which codes for a corresponding enzyme with a low activity or inactivates the corresponding gene or enzyme (protein), and optionally combining these measures. [0037] By attenuation measures, the activity or concentration of the corresponding protein is in general reduced to 0 to 75%, 0 to 50%, 0 to 25%, 0 to 10% or 0 to 5% of the activity or concentration of the wild-type protein or of the activity or concentration of the protein in the starting microorganism. These ranges include all specific values and subranges therebetween, such as 2, 3, 8, 12, 15, 20, 30, 40, 60, and 70% of the activity or concentration of the wild-type protein or of the activity or concentration of the protein in the starting microorganism. [0038] The microorganisms provided by the present invention can prepare amino acids from glucose, sucrose, lactose, fructose, maltose, molasses, starch, cellulose or from glycerol and ethanol. They can be representatives of coryneform bacteria, in particular of the genus Corynebacterium. Of the genus Corynebacterium, there may be mentioned in particular the species Corynebacterium glutamicum, which is known among experts for its ability to produce L-amino acids. [0039] Suitable strains of the genus Corynebacterium, in particular of the species Corynebacterium glutamicum, are in particular the known wild-type strains Corynebacterium glutamicum ATCC13032 Corynebacterium acetoglutamicum ATCC15806 Corynebacterium acetoacidophilum ATCC13870 Corynebacterium melassecola ATCC 17965 Corynebacterium thermoaminogenes FERM BP-1539 Brevibacterium flavum ATCC14067 Brevibacterium lactofermentum ATCC13869 and Brevibacterium divaricatum ATCC14020 and L-amino acid-producing mutants or strains prepared therefrom such as, for example, the L-lysine-producing strains Corynebacterium glutamicum FERM-P 1709 Brevibacterium flavum FERM-P 1708 Brevibacterium lactofermentum FERM-P 1712 Corynebacterium glutamicum FERM-P 6463 Corynebacterium glutamicum FERM-P 6464 and Corynebacterium glutamicum DSM 5715. [0054] It has been found that coryneform bacteria produce L-amino acids in an improved manner after attenuation of the otsB gene, which codes for trehalose phosphatase (EC:3.1.3.12), and/or the treY gene, which codes for maltooligosyl-trehalose synthase, and/or the treZ gene, which codes for maltooligosyl-trehalose trehalohydrolase. [0055] The nucleotide sequence of the gene which codes for the trehalose phosphatase of Corynebacterium glutamicum can be found in the patent application WO 01/00843 under Identification Code RXA00347 as SEQ ID No. 1139. [0056] The nucleotide sequence of the gene which codes for the maltooligosyl-trehalose synthase of Corynebacterium glutamicum can be found in the patent application WO 01/00843 under Identification Code FRXA01239 as SEQ ID No. 1143. [0057] The nucleotide sequence of the gene which codes for the maltooligosyl-trehalose trehalohydrolase of Corynebacterium glutamicum can be found in the patent application WO 01/00843 under Identification Code RXA02645 as SEQ ID No. 1145. [0058] The nucleotide sequences are also deposited in the gene library under Accession Number AX064857, AX064861 and AX064863. [0059] The nucleotide sequences of the present invention, of the genes which code for trehalose phosphatase, for maltooligosyl-trehalose synthase and for maltooligosyl-trehalose trehalohydrolase, shown in SEQ ID No. 1, SEQ ID No. 3 or SEQ ID No. 5 are lengthened compared with the sequences known from the publications cited above by in each case preferably up to 700 base pairs before the start codon and after the stop codon of the gene. [0060] The lengthenings compared with the sequence known from the publications cited above comprise base pairs 1 to 500 and 1392 to 1977 in SEQ ID No. 1. [0061] In SEQ ID No. 3 the lengthenings compared with the sequence known from the publications cited above comprise base pairs 1 to 500 and 3057 to 3636. [0062] In SEQ ID No. 5 the lengthenings compared with the sequence known from the publications cited above comprise base pairs 1 to 500 and 2454 to 3033. [0063] The amino acid sequences of the associated gene products are shown in SEQ ID No. 2, SEQ ID No. 4 or SEQ ID No. 6. [0064] It has been found that attenuation processes which are known per se can be employed particularly successfully with the aid of the lengthened sequences thus provided. [0065] Such a process is the method of gene replacement. In this, a mutation, such as e.g. a deletion, insertion or base exchange, is established in vitro in the gene of interest. The allele prepared is in turn cloned in a vector which is not replicative for C. glutamicum and this is then transferred into the desired host of C. glutamicum by transformation or conjugation. After homologous recombination by means of a first “cross-over” event which effects integration and a suitable second “cross-over” event which effects excision in the target gene or in the target sequence, the incorporation of the mutation or of the allele is achieved. This method was used, for example, in EP: 00110021.3 to eliminate the secG gene of C. glutamicum. [0066] The lengthening of the sequences employed is not limited to 600 base pairs before the start codon and after the stop codon. It is preferably in the range from 300 to 700 base pairs, but can also be up to 800 base pairs. These ranges include all specific values and subranges therebetween, such as 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700, 725, 750, and 775 base pairs. The lengthenings can also contain different amounts of base pairs. [0067] The sequences described in the text references mentioned which code for trehalose phosphatase, maltooligosyl-trehalose synthase and maltooligosyl-trehalose trehalohydrolase can be used according to the invention. Alleles of trehalose phosphatase, maltooligosyl-trehalose synthase or maltooligosyl-trehalose trehalohydrolase which result from the degeneracy of the genetic code or due to “sense mutations” of neutral function can furthermore be used. [0068] To achieve an attenuation, either the expression of the gene which codes for trehalose phosphatase and/or the expression of the gene which codes for maltooligosyl-trehalose synthase and/or the expression of the gene which codes for maltooligosyl-trehalose trehalohydrolase or the catalytic properties of the gene products can be reduced or eliminated. The two measures are optionally combined. [0069] The gene expression can be reduced by suitable culturing or by genetic modification (mutation) of the signal structures of gene expression. Signal structures of gene expression are, for example, repressor genes, activator genes, operators, promoters, attenuators, ribosome binding sites, the start codon and terminators. The expert can find information on this e.g. in the patent application WO 96/15246, in Boyd and Murphy (Journal of Bacteriology 170: 5949 (1988)), in Voskuil and Chambliss (Nucleic Acids Research 26: 3548 (1998), in Jensen and Hammer (Biotechnology and Bioengineering 58: 191 (1998)), in Pátek et al. (Microbiology 142: 1297 (1996)) and in known textbooks of genetics and molecular biology, such as e.g. the textbook by Knippers (“Molekulare Genetik”, 6th edition, Georg Thieme Verlag, Stuttgart, Germany, 1995) or that by Winnacker (“Gene und Klone”, VCH Verlagsgesellschaft, Weinheim, Germany, 1990). [0070] Mutations which lead to a change or reduction in the catalytic properties of enzyme proteins are known from the prior art; examples which may be mentioned are the works by Qiu and Goodman (Journal of Biological Chemistry 272: 8611-8617 (1997)), Sugimoto et al. (Bioscience Biotechnology and Biochemistry 61: 1760-1762 (1997)) and Möckel (“Die Threonindehydratase aus Corynebacterium glutamicum: Aufhebung der allosterischen Regulation und Struktur des Enzyms”, Reports from the Jülich Research Centre, Jül1-2906, ISSN09442952, Jülich, Germany, 1994). Summarizing descriptions can be found in known textbooks of genetics and molecular biology, such as e.g. that by Hagemann (“Allgemeine Genetik”, Gustav Fischer Verlag, Stuttgart, 1986). [0071] Possible mutations are transitions, transversions, insertions and deletions. Depending on the effect of the amino acid exchange on the enzyme activity, “missense mutations” or “nonsense mutations” are referred to. Insertions or deletions of at least one base pair in a gene lead to “frame shift mutations”, as a consequence of which incorrect amino acids are incorporated or translation is interrupted prematurely. Deletions of several codons typically lead to a complete loss of the enzyme activity. Instructions on generation of such mutations are prior art and can be found in known textbooks of genetics and molecular biology, such as e.g. the textbook by Knippers (“Molekulare Genetik”, 6th edition, Georg Thieme Verlag, Stuttgart, Germany, 1995), that by Winnacker (“Gene und Kione”, VCH Verlagsgesellschaft, Weinheim, Germany, 1990) or that by Hagemann (“Allgemeine Genetik”, Gustav Fischer Verlag, Stuttgart, 1986). [0072] A common method of mutating genes of C. glutamicum is the method of “gene disruption” and “gene replacement” described by Schwarzer and Pühler (Bio/Technology 9, 84-87 (1991)). [0073] In the method of gene disruption a central part of the coding region of the gene of interest is cloned in a plasmid vector which can replicate in a host (typically E. coli ), but not in C. glutamicum. Possible vectors are, for example, pSUP301 (Simon et al., Bio/Technology 1, 784-791 (1983)), pK18mob or pK19mob (Schäfer et al., Gene 145, 69-73 (1994)), pK18mobsacB or pK19mobsacB (Jager et al., Journal of Bacteriology 174: 5462-65 (1992)), pGEM-T (Promega Corporation, Madison, Wis., USA), pCR2.1-TOPO (Shuman (1994). Journal of Biological Chemistry 269:32678-84; U.S. Pat. No. 5,487,993), pCR®Blunt (Invitrogen, Groningen, Holland; Bernard et al., Journal of Molecular Biology, 234: 534-541 (1993)) or pEM1 (Schrumpf et al, 1991, Journal of Bacteriology 173:4510-4516). The plasmid vector which contains the central part of the coding region of the gene is then transferred into the desired strain of C. glutamicum by conjugation or transformation. The method of conjugation is described, for example, by Schäfer et al. (Applied and Environmental Microbiology 60, 756-759 (1994)). Methods for transformation are described, for example, by Thierbach et al. (Applied Microbiology and Biotechnology 29, 356-362 (1988)), Dunican and Shivnan (Bio/Technology 7, 1067-1070 (1989)) and Tauch et al. (FEMS Microbiological Letters 123, 343-347 (1994)). After homologous recombination by means of a “cross-over” event, the coding region of the gene in question is interrupted by the vector sequence and two incomplete alleles are obtained, one lacking the 3′ end and one lacking the 5′ end. This method has been used, for example, by Fitzpatrick et al. (Applied Microbiology and Biotechnology 42, 575-580 (1994)) to eliminate the recA gene of C. glutamicum. [0074] In the method of “gene replacement”, a mutation, such as e.g. a deletion, insertion or base exchange, is established in vitro in the gene of interest. The allele prepared is in turn cloned in a vector which is not replicative for C. glutamicum and this is then transferred into the desired host of C. glutamicum by transformation or conjugation. After homologous recombination by means of a first “cross-over” event which effects integration and a suitable second “cross-over” event which effects excision in the target gene or in the target sequence, the incorporation of the mutation or of the allele is achieved. This method was used, for example, by Peters-Wendisch et al. (Microbiology 144, 915 -927 (1998)) to eliminate the pyc gene of C. glutamicum by a deletion. [0075] A deletion, insertion or a base exchange can be incorporated in this manner into the gene which codes for trehalose phosphatase and/or the gene which codes for maltooligosyl-trehalose synthase and/or the gene which codes for maltooligosyl-trehalose trehalohydrolase. [0076] In addition, it may be advantageous for the production of L-amino acids to enhance, in particular over-express, one or more enzymes of the particular biosynthesis pathway, of glycolysis, of anaplerosis, of the citric acid cycle, of the pentose phosphate cycle, of amino acid export and optionally regulatory proteins, in addition to the attenuation of the gene which codes for trehalose phosphatase and/or the gene which codes for maltooligosyl-trehalose synthase and/or the gene which codes for maltooligosyl-trehalose trehalohydrolase. [0077] The term “enhancement” or “enhance” in this connection describes the increase in the intracellular activity of one or more enzymes or proteins in a microorganism which are coded by the corresponding DNA, for example by increasing the number of copies of the gene or genes, using a potent promoter or a gene which codes for a corresponding enzyme or protein with a high activity, and optionally combining these measures. [0078] By enhancement measures, in particular over-expression, the activity or concentration of the corresponding protein is in general increased by at least 10%, 25%, 50%, 75%, 100%, 150%, 200%, 300%, 400% or 500%, up to a maximum of 1000% or 2000%, based on that of the wild-type protein or the activity or concentration of the protein in the starting microorganism. [0079] Thus, for the production of amino acids, in particular L-lysine or L-glutamic acid, in addition to the attenuation of the gene which codes for trehalose phosphatase and/or the gene which codes for maltooligosyl-trehalose synthase and/or the gene which codes for maltooligosyl-trehalose trehalohydrolase, one or more of the genes chosen from the group consisting of the lysC gene which codes for a feed-back resistant aspartate kinase (Accession No.P26512, EP-B-0387527; EP-A-0699759; WO 00/63388), the dapA gene which codes for dihydrodipicolinate synthase (EP-B 0 197 335), the gap gene which codes for glyceraldehyde 3-phosphate dehydrogenase (Eikmanns (1992). Journal of Bacteriology 174:6076-6086), at the same time the pyc gene which codes for pyruvate carboxylase (DE-A-198 31 609), the mqo gene which codes for malate:quinone oxidoreductase (Molenaar et al., European Journal of Biochemistry 254, 395-403 (1998)), (attenuation or enhancement???) the zwf gene which codes for glucose 6-phosphate dehydrogenase (JP-A-09224661), at the same time the lysE gene which codes for lysine export (DE-A-195 48 222), the zwa1 gene which codes for the Zwa1 protein (DE: 19959328.0, DSM 13115) the tpi gene which codes for triose phosphate isomerase (Eikmanns (1992), Journal of Bacteriology 174:6076-6086), and the pgk gene which codes for 3-phosphoglycerate kinase (Eikmanns (1992), Journal of Bacteriology 174:6076-6086), can be enhanced, in particular over-expressed. [0090] It may furthermore be advantageous for the production of amino acids, in particular L-lysine or L-glutamic acid, in addition to the attenuation of the gene which codes for trehalose phosphatase and/or the gene which codes for maltooligosyl-trehalose synthase and/or the gene which codes for maltooligosyl-trehalose trehalohydrolase, at the same time for one or more of the genes chosen from the group consisting of the pck gene which codes for phosphoenol pyruvate carboxykinase (DE 199 50 409.1, DSM 13047), the pgi gene which codes for glucose 6-phosphate isomerase (U.S. Ser. No. 09/396,478, DSM 12969), the poxB gene which codes for pyruvate oxidase (DE: 1995 1975.7, DSM 13114), [0094] the zwa2 gene which codes for the Zwa2 protein (DE: 19959327.2, DSM 13113), the horn gene which codes for homoserine dehydrogenase (EP-A-0131171) and the thrB gene which codes for homoserine kinase (Peoples, O. W., et al., Molecular Microbiology 2 (1988): 63-72) to be attenuated, in particular for the expression thereof to be reduced. [0097] Finally, it may be advantageous for the production of amino acids, in addition to the attenuation of the gene which codes for trehalose phosphatase and/or the gene which codes for maltooligosyl-trehalose synthase and/or the gene which codes for maltooligosyl-trehalose trehalohydrolase, to eliminate undesirable side reactions (Nakayama: “Breeding of Amino Acid Producing Micro-organisms”, in: Overproduction of Microbial Products, Krumphanzl, Sikyta, Vanek (eds.), Academic Press, London, UK, 1982). [0098] The invention also provides the microorganisms prepared according to the invention, and these can be cultured continuously or discontinuously in the batch process (batch culture) or in the fed batch (feed process) or repeated fed batch process (repetitive feed process) for the purpose of production of L-amino acids. A summary of known culture methods is described in the textbook by Chmiel (Bioprozesstechnik 1. Einführung in die Bioverfahrenstechnik (Gustav Fischer Verlag, Stuttgart, 1991)) or in the textbook by Storhas (Bioreaktoren und periphere Einrichtungen (Vieweg Verlag, Braunschweig/Wiesbaden, 1994)). [0099] The culture medium to be used must meet the requirements of the particular strains in a suitable manner. Descriptions of culture media for various microorganisms are contained in the handbook “Manual of Methods for General Bacteriology” of the American Society for Bacteriology (Washington D.C., USA, 1981). [0100] Sugars and carbohydrates, such as e.g. glucose, sucrose, lactose, fructose, maltose, molasses, starch and cellulose, oils and fats, such as e.g. soya oil, sunflower oil, groundnut oil and coconut fat, fatty acids, such as e.g. palmitic acid, stearic acid and linoleic acid, alcohols, such as e.g. glycerol and ethanol, and organic acids, such as e.g. acetic acid, can be used as the source of carbon. These substances can be used individually or as a mixture. [0101] Organic nitrogen-containing compounds, such as peptones, yeast extract, meat extract, malt extract, corn steep liquor, soya bean flour and urea, or inorganic compounds, such as ammonium sulfate, ammonium chloride, ammonium phosphate, ammonium carbonate and ammonium nitrate, can be used as the source of nitrogen. The sources of nitrogen can be used individually or as a mixture. [0102] Phosphoric acid, potassium dihydrogen phosphate or dipotassium hydrogen phosphate or the corresponding sodium-containing salts can be used as the source of phosphorus. The culture medium must furthermore comprise salts of metals, such as e. g. magnesium sulfate or iron sulfate, which are necessary for growth. Finally, essential growth substances, such as amino acids and vitamins, can be employed in addition to the abovementioned substances. Suitable precursors can moreover be added to the culture medium. The starting substances mentioned can be added to the culture in the form of a single batch, or can be fed in during the culture in a suitable manner. [0103] Basic compounds, such as sodium hydroxide, potassium hydroxide, ammonia or aqueous ammonia, or acid compounds, such as phosphoric acid or sulfuric acid, can be employed in a suitable manner to control the pH of the culture. Antifoams, such as e.g. fatty acid polyglycol esters, can be employed to control the development of foam. Suitable substances having a selective action, such as e.g. antibiotics, can be added to the medium to maintain the stability of plasmids. To maintain aerobic conditions, oxygen or oxygen-containing gas mixtures, such as e.g. air, are introduced into the culture. The temperature of the culture is usually 20° C. to 45° C., and preferably 25° C. to 40° C. Culturing is continued until a maximum of the desired product has formed. This target is usually reached within 10 hours to 160 hours. [0104] Methods for the determination of L-amino acids are known from the prior art. The analysis can thus be carried out as described by Spackman et al. (Analytical Chemistry, 30, (1958), 1190) by anion exchange chromatography with subsequent ninhydrin derivatization, or it can be carried out by reversed phase HPLC, for example as described by Lindroth et al. (Analytical Chemistry (1979) 51: 1167-1174). EXAMPLES [0105] Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified. Example 1 Preparation of Integration Vectors for Integration Mutagenesis of the otsB, treY and treZ Genes [0106] From the strain ATCC 13032, chromosomal DNA is isolated by the method of Eikmanns et al. (Microbiology 140: 1817-1828 (1994)). [0107] On the basis of the sequence of the otsB, treY and treZ genes known for C. glutamicum (WO 01/00843), the following oligonucleotides are chosen for the polymerase chain reaction: otsB-int1: 5′ GTC CGA TTT TGA TGG AAC C 3′ otsB-int2: 5′ GGA GCT GAT GGA GTA TTC G 3′ treY-int1: 5′ TTT TCC GTG AAT ACG TTG G 3′ treY-int2: 5′ GCG ACT AAT TCG ATG ATG G 3′ treZ-int1: 5′ TGG TTC GAA GAT TTT CAC G 3′ treZ-int2: 5′ GGC GAG CTG TAG ATA ATG G 3′ [0108] The primers shown are synthesized by MWG Biotech (Ebersberg, Germany) and the PCR reaction is carried out by the standard PCR method of Innis et al. (PCR Protocols. A Guide to Methods and Applications, 1990, Academic Press) with the Taq-polymerase from Boehringer Mannheim (Germany, Product Description Taq DNA polymerase, Product No. 1 146 165). With the aid of the polymerase chain reaction, the primers allow amplification of an internal fragment of the otsB gene 463 bp in size, an internal fragment of the treY gene 530 bp in size and an internal fragment of the treZ gene 530 bp in size. The products amplified in this way are tested electrophoretically in a 0.8% agarose gel. [0109] The amplified DNA fragments are ligated with the TOPO TA Cloning Kit from Invitrogen Corporation (Carlsbad, Calif., USA; Catalogue Number K4500-01) in each case in the vector pCR2.1-TOPO (Mead at al. (1991) Bio/Technology 9:657-663). [0110] The E. coli strain TOP10 is then electroporated with the ligation batches (Hanahan, In: DNA Cloning. A Practical Approach. Vol. I, IRL-Press, Oxford, Washington D.C., USA, 1985). Selection for plasmid-carrying cells is made by plating out the transformation batch on LB agar (Sambrook et al., Molecular Cloning: A Laboratory Manual. 2 nd Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989), which had been supplemented with 50 mg/l kanamycin. Plasmid DNA is isolated from in each case one transformant with the aid of the QIAprep Spin Miniprep Kit from Qiagen and checked by restriction with the restriction enzyme EcoRI and subsequent agarose gel electrophoresis (0.8%). The plasmids are called pCR2.1otsBint, pCR2.1treYint and pCR2.1treZint and are shown in FIG. 1 , FIG. 2 and FIG. 3 . [0111] The following microorganisms are deposited as a pure culture on 24 Apr. 2001 at the Deutsche Sammlung für Mikroorganismen und Zellkulturen (DSMZ=German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany) in accordance with the Budapest Treaty: Escherichia coli Top 10/pCR2.1otsBint as DSM 14259, Escherichia coli Top 10/pCR2.1treYint as DSM 14260, Escherichia coli Top 10/pCR2.1treZint as DSM 14261. Example 2 Integration Mutagenesis of the otsB Gene in the Strain DSM 5715 [0115] The vector pCR2.1otsBint mentioned in example 1 is electroporated by the electroporation method of Tauch et al.(FEMS Microbiological Letters, 123:343-347 (1994)) in Corynebacterium glutamicum DSM 5715. The strain DSM 5715 is an AEC-resistant lysine producer. The vector pCR2.1otsBint cannot replicate independently in DSM5715 and is retained in the cell only if it has integrated into the chromosome of DSM 5715. Selection of clones with pCR2.1otsBint integrated into the chromosome is carried out by plating out the electroporation batch on LB agar (Sambrook et al., Molecular cloning: A Laboratory Manual. 2 nd Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.), which had been supplemented with 15 mg/l kanamycin. [0116] For detection of the integration, the otsBint fragment is labelled with the Dig hybridization kit from Boehringer by the method of “The DIG System Users Guide for Filter Hybridization” of Boehringer Mannheim GmbH (Mannheim, Germany, 1993). Chromosomal DNA of a potential integrant is isolated by the method of Eikmanns et al. (Microbiology 140: 1817-1828 (1994)) and in each case cleaved with the restriction enzymes EcoRI, SalI and PstI. The fragments formed are separated by means of agarose gel electrophoresis and hybridized at 68° C. with the Dig hybridization kit from Boehringer. The plasmid pCR2.1otsBint mentioned in example 3 has been inserted into the chromosome of DSM5715 within the chromosomal otsB gene. The strain is called DSM5715::pCR2.1otsBint. Example 3 Integration Mutagenesis of the treY Gene in the Strain DSM 5715 [0117] The vector pCR2.1treYint mentioned in example 1 is electroporated by the electroporation method of Tauch et al.(FEMS Microbiological Letters, 123:343-347 (1994)) in Corynebacterium glutamicum DSM 5715. The strain DSM 5715 is an AEC-resistant lysine producer. The vector pCR2.1treYint cannot replicate independently in DSM5715 and is retained in the cell only if it has integrated into the chromosome of DSM 5715. Selection of clones with pCR2.1treYint integrated into the chromosome is carried out by plating out the electroporation batch on LB agar (Sambrook et al., Molecular cloning: A Laboratory Manual. 2 nd Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.), which had been supplemented with 15 mg/l kanamycin. [0118] For detection of the integration, the treYint fragment is labelled with the Dig hybridization kit from Boehringer by the method of “The DIG System Users Guide for Filter Hybridization” of Boehringer Mannheim GmbH (Mannheim, Gerrnany, 1993). Chromosomal DNA of a potential integrant is isolated by the method of Eikmanns et al. (Microbiology 140: 1817-1828 (1994)) and in each case cleaved with the restriction enzymes EcoRI, BamHI and PstI. The fragments formed are separated by means of agarose gel electrophoresis and hybridized at 68° C. with the Dig hybridization kit from Boehringer. The plasmid pCR2.1treYint mentioned in example 3 has been inserted into the chromosome of DSM5715 within the chromosomal treY gene. The strain is called DSM5715::pCR2.1treYint. Example 4 Integration Mutagenesis of the treZ Gene in the Strain DSM 5715 [0119] The vector pCR2.1treZint mentioned in example 1 is electroporated by the electroporation method of Tauch et al.(FEMS Microbiological Letters, 123:343-347 (1994)) in Corynebacterium glutamicum DSM 5715. The strain DSM 5715 is an AEC-resistant lysine producer. The vector pCR2.1treZint cannot replicate independently in DSM5715 and is retained in the cell only if it has integrated into the chromosome of DSM 5715. Selection of clones with pCR2.1treZint integrated into the chromosome is carried out by plating out the electroporation batch on LB agar (Sambrook et al., Molecular cloning: A Laboratory Manual. 2 nd Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.), which had been suppimented with 15 mg/l kanamycin. [0120] For detection of the integration, the treZint fragment is labelled with the Dig hybridization kit from Boehringer by the method of “The DIG System Users Guide for Filter Hybridization” of Boehringer Mannheim GmbH (Mannheim, Germany, 1993). Chromosomal DNA of a potential integrant is isolated by the method of Eikmanns et al. (Microbiology 140: 1817-1828 (1994)) and in each case cleaved with the restriction enzymes EcoRI, EcoRV and PstI. The fragments formed are separated by means of agarose gel electrophoresis and hybridized at 68° C. with the Dig hybridization kit from Boehringer. The plasmid pCR2.1treZint mentioned in example 3 has been inserted into the chromosome of DSM5715 within the chromosomal treZ gene. The strain is called DSM5715::pCR2.1treZint. Example 5 Preparation of Lysine [0121] The C. glutamicum strains DSM5715::pCR2.1otsbint, DSM5715::pCR2.1treYint and DSM5715::pCR2.1treZint obtained in example 2, example 3 and example 4 are cultured in a nutrient medium suitable for the production of lysine and the lysine content in the culture supernatant is determined. [0122] For this, the strains are first incubated on an agar plate with the corresponding antibiotic (brain-heart agar with kanamycin (25 mg/l) for 24 hours at 33° C. Starting from this agar plate culture, in each case a preculture is seeded (10 ml medium in a 100 ml conical flask). The complete medium CgIII is used as the medium for the preculture. Medium Cg III NaCl 2.5 g/l Bacto-Peptone 10 g/l Bacto-Yeast extract 10 g/l Glucose (autoclaved separately) 2% (w/v) The pH is brought to pH 7.4 [0123] Kanamycin (25 mg/l) is added to this. The precultures are incubated for 16 hours at 33° C. at 240 rpm on a shaking machine. In each case a main culture is seeded from these precultures such that the initial OD (660 nm) of the main cultures is 0.1. Medium MM is used for the main culture. Medium MM CSL (corn steep liquor) 5 g/l MOPS (morpholinopropanesulfonic acid) 20 g/l Glucose (autoclaved separately) 50 g/l Salts: (NH 4 ) 2 SO 4 25 g/l KH 2 PO 4 0.1 g/l MgSO 4 * 7H 2 O 1.0 g/l CaCl 2 * 2H 2 O 10 mg/l FeSO 4 * 7H 2 O 10 mg/l MnSO 4 * H 2 O 5.0 mg/l Biotin (sterile-filtered) 0.3 mg/l Thiamine * HCl (sterile-filtered) 0.2 mg/l Leucine (sterile-filtered) 0.1 g/l CaCO 3 25 g/l [0124] The CSL, MOPS and the salt solution are brought to pH 7 with aqueous ammonia and autoclaved. The sterile substrate and vitamin solutions are then added, and the CaCO 3 autoclaved in the dry state is added. [0125] Culturing is carried out in a 10 ml volume in 100 ml conical flasks with baffles. Kanamycin (25 mg/l) was added. Culturing is carried out at 33° C. and 80% atmospheric humidity. [0126] After 72 hours, the OD is determined at a measurement wavelength of 660 nm with a Biomek 1000 (Beckmann Instruments GmbH, Munich). The amount of lysine formed is in each case determined with an amino acid analyzer from Eppendorf-BioTronik (Hamburg, Germany) by ion exchange chromatography and post-column derivatization with ninhydrin detection. [0127] The result of the experiment is shown in table 1. TABLE 1 Strain OD Lysine HCl DSM5715 7.3 12.48 DSM5715::pCR2.1otsBint 7.5 13.45 DSM5715::pCR2.1treYint 7.5 13.13 DSM5715::pCR2.1treZint 8.1 13.84 [0128] Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. [0129] All of the publications cited above are incorporated herein by reference.

A process for the preparation of L-amino acids, in which the following steps are carried out: (a) fermentation of the coryneform bacteria which produce the desired L-amino acid and in which at least the gene which codes for trehalose phosphatase and/or the gene which codes for maltooligosyl-trehalose synthase and/or the gene which codes for maltooligosyl-trehalose trehalohydrolase is or are attenuated, (b) concentration of the desired L-amino acid in the medium or in the cells of the bacteria, and (c) isolation of the L-amino acid, and optionally bacteria in which further genes of the biosynthesis pathway of the desired L-amino acid are addtionally enhanced are employed, or bacteria in which the metabolic pathways which reduce the formation of the desired L-amino acid are at least partly eliminated are employed.

FIELD OF THE INVENTION This invention relates to an ultraviolet radiation/oxidation apparatus for the decontamination of fluids using a high intensity, directed light source and a fluid container made of high tensile strength material. BACKGROUND OF THE INVENTION The combination of ultraviolet radiation and oxidant is a powerful tool for the removal of organic and microbial contaminants from fluids, particularly water. Ultraviolet radiation/oxidation systems are faster and capable of oxidizing more types of chemicals than systems using ultraviolet radiation or oxidant alone. Both hydrogen peroxide and ozone are suitable oxidants for use in ultraviolet radiation/oxidation systems, but ozone is more economical and therefore more often used. Ozone alone is a strong oxidizing agent that can react with all oxidizable contaminants in the fluid; however, the rate of oxidation can be enhanced by the simultaneous application of ultraviolet radiation. According to equation 1, ultraviolet radiation accelerates the decay of ozone dissolved in water to the hydroxyl radical (.OH), one of the most powerful oxidants known. ##STR1## Oxidation of organic contaminants by ultraviolet radiation and ozone ultimately yields non-harmful products, carbon dioxide, water and oxygen according to Equation 2. The application of ultraviolet radiation and ozone for control of microbial contamination is also a very efficient process because the cell wall of the microorganism is ruptured, killing the organism. ##STR2## Known ultraviolet radiation/oxidation systems suffer a serious disadvantage, however. Typically a germicidal ultraviolet lamp is enclosed in a sleeve which is immersed in the fluid to be treated so that the ultraviolet radiation propagates through the fluid. In prior art systems these sleeves have been made of quartz, one of the few materials that is transparent to the high energy, short wavelength ultraviolet light that promotes the reactions described above Quartz sleeves often require cleaning due to water caused fouling. A film tends to accumulate on the quartz sleeve which decreases transmission of the ultraviolet radiation to the fluid. The frequent mechanical or chemical cleaning which is required to remove the film is extremely inefficient since it requires shutting down the fluid decontamination system and draining the fluid to reach the surfaces needing cleaning. Furthermore, quartz which is subjected to ultraviolet light is solarized, producing a slightly tan color in the quartz which also reduces transmission. Most importantly, quartz sleeves are fragile and expensive. Immersion of the quartz sleeve in the fluid to be treated disrupts the straight forward flow of the fluid through the reaction vessel and creates eddies and subcurrents such that all the fluid is not irradiated or exposed to the oxidant to an equal extent. Therefore, the contaminants are inefficiently treated. SUMMARY OF THE INVENTION According to this invention an ultraviolet radiation/oxidation apparatus is provided which minimizes the disadvantages associated with quartz and immersion of a quartz sleeve into the fluid to be treated. In addition, the ultraviolet radiation/oxidation apparatus of this invention allows fluid treatment at high or low pressures and it tolerates sudden pressure changes. One embodiment of this invention provides a high tensile strength alloy or steel container with a reflective interior surface that is lined with an inert, non-sticking material which is transparent to ultraviolet radiation, such as fluorinated ethylene propylene. The non-stick nature of fluorinated ethylene propylene prevents fouling of the container's interior which simplifies cleaning and maintenance of the ultraviolet radiation/oxidation apparatus. An oxidant is injected into the fluid which is irradiated with ultraviolet light while in the container. A high intensity, directed beam of ultraviolet radiation enters the container through an ultraviolet transparent window, and because the beam is directed, the window can be small. If the window is quartz, its small size simplifies cleaning and reduces the expense associated with prior art quartz sleeves. The quartz window may be lined with, or otherwise protected by, fluorinated ethylene propylene to prevent fouling of the window, further simplifying maintenance of the apparatus. The use of a directed, high intensity light source rather than a diffuse light source, such as the germicidal lamps used in the prior art, eliminates the need for reflectors or some other system of collecting and directing the diffuse light. Most importantly, the use of high intensity light according to this invention directs more the desired oxidation more efficiently, leading to shorter reaction times. The reflective interior surface of the container repeatedly reflects the ultraviolet radiation, thereby irradiating a substantial portion of the container's volume. The ultraviolet transparent lining which covers the reflective interior surface allows this reflection. The high tensile strength material forming the container allows the treatment of fluids at high or low pressures and tolerates sudden pressure changes. By avoiding immersion of an ultraviolet lamp and its quartz sleeve into the fluid, the apparatus according to this invention allows straightforward flow of the fluid, and therefore avoids the generation of eddies and subcurrents that can cause some portions of the fluid to be inefficiently treated. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of one embodiment of an ultraviolet radiation/oxidation apparatus according to this invention. FIG. 2 is a side view of the assembled apparatus shown in FIG. 1. FIG. 3 shows a typical mated flange for joining the sections of the apparatus in FIG. 2. FIG. 4 is a schematic view of a laser system for producing a directed beam of ultraviolet light. FIG. 5 shows one embodiment of ridges formed by routing of the container. DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, fluid enters a high tensile strength alloy or steel container 1 from inflow source 2. Fluid exits the container 1 through an out-flow chamber 3 having one or more dispersing pipes, shown here as pipes 3a and 3b, also made of a high tensile strength material. Outflow chamber 3 and container 1, which may form a "Y," are joined as described below. The reaction vessel of an apparatus according to this invention comprises container 1, inflow source 2 and out-flow chamber 3. At the base of the converging pipes 3a and 3b, a window 6 is seated in an opening which is sealed like a port-hole with an ozone impervious gasket 5 and the necessary plates (not shown). The light source 7 produces a high intensity ultraviolet light beam directed toward window 6 which is made of a material transparent to ultraviolet radiation, such as quartz. The interior of container 1 is formed with a surface 9 that is highly reflective to ultraviolet radiation, such as polished aluminum. The light beam from light source 7 passes through window 6 and is repeatedly reflected by the interior of container 1 so that a substantial portion of the volume of container 1 is irradiated. Window 6 can be formed so that the light beam from light source 7 is flared by passing through window 6, thereby irradiating a substantial portion of the container's volume. Alternatively, the light may be scattered throughout container 1 by ridges 1a formed by routing the interior of container 1. Reflective surface 9 covers the entire interior of container 1, both the ridged and routed areas. The interiors of container 1 and out-flow chamber 3 are lined with a material that is chemically inert under conditions encountered by the apparatus during oxidation of organic contaminants. The material lining the interior of container 1 should also be transparent to ultraviolet radiation so that the lining does not prevent reflection of ultraviolet radiation by surface 9. The lining 10 will protect container 1 and inflow 2, and lining 4 will protect out-flow chamber 3, from corrosion and fouling caused by the similarly protected by cone shaped lining 8 which can be integrally formed lining 4. The cone shape of lining 8 will facilitate fluid flow and aid in the prevention of eddies and subcurrents by directing the fluid flow to pipes 3a and 3b. The linings 10, 4 and 8 may be attached to the reaction vessel by any suitable, fluid-tight means as described below. Fluoridated ethylene propylene can provide the non-wetting, non-sticking, but ultraviolet transparent linings 10, 4 and 8 required. This material prevents film accumulation on the interior walls of container 1 and outflow chamber 3 caused by contaminants in the fluid being treated, thereby simplifying cleaning and maintenance of the apparatus. Prevention or removal of film accumulated on the interior of container 1 is important because the film would decrease the reflectivity of reflective surface 9, and therefore would decrease the efficiency of ultraviolet light transfer throughout container 1. In addition, fluorinated ethylene propylene is chemically inert to most substances and it will not deteriorate under long exposure to ultraviolet light. The base of inflow 2 has an injection port 11 for injecting an oxidant such as hydrogen peroxide or ozone. Ozone can be produced as needed with an ozone generator according to well known methods. A plurality of injection ports may be used to increase the quantity and the rate of oxidant addition. FIG. 2 illustrates a side view of the apparatus described above. Container 1 and inflow 2 are assembled from two half shells, upper half 12 and lower half 13, both of which have flanged edges 15 which are mated and securely fastened with bolts 16. Out-flow chamber 3 is a solid, one piece unit also having a flange 15 which mates with a flange of assembled container 1 and is fastened to container 1 with bolts 16. A typical mated flange 15 is shown in FIG. 3. Gasket 17 made of a material which is impervious to ozone, such as teflon, is positioned to form a fluid-tight seal between the joined, bolted sections. The bolt 16 is inserted through bolt hole 18. Because the apparatus can be disassembled and the interior is easily accessible, this construction simplifies cleaning and maintenance of the interior, including replacement of the linings 10 and 4 and of the window 6. The lining 10 can be formed in 2 pieces which fit halves 12 and 13 so that each half will be lined by one continuous segment of fluorinated ethylene propylene material. The lining 4, integrally formed with cone shaped lining 8, can be formed as a one piece unit which conforms to the one-piece out-flow chamber 3. The linings 10 and 4 may extend to a position between mated flanges 15 so that the linings act as a gasket. This configuration also insures secure attachment of the linings 10 and 4 to the container 1 and the out-flow chamber 3, respectively. Ridges 1a formed by routing the interior of container 1 will also stabilize placement of the lining 10 in container 1. The ridges are preferably arranged in a criss-cross, diamond pattern. Lining 10 is pressed or molded to fill the routed areas and covers the ridges so that the interior of container 1 presents a smooth, lined surface. Consequently, lining 10 is formed with a varying thickness having indentations corresponding to the ridges 1a of container 1. The coupling of these ridges and indentations prohibits any movement of lining 10 relative to container 1 by locking the lining in place. The smooth surface of lining 10 facilitates direct fluid flow, as is necessary to prevent the generation of eddies and subcurrents in the reaction vessel. The light source 7 may be a laser or a configuration of lasers according to FIG. 4. High pulse energy Nd:YAG laser 20 produces a beam with a wavelength of 355 nm which acts as a pump source for the pulsed dye laser 21. The dye for pulsed dye laser 21 is chosen to allow the laser configuration according to FIG. 4 to ultimately produce an output beam in the ultraviolet range. The frequency of the beam from pulsed dye laser 21 is doubled using a barium-borate crystal 22 to achieve the desired wavelength spectrum. A microprocessor scan control unit 23 is connected to both the pulsed dye laser 21 and the barium-borate crystal 22 to control the final wavelength of light produced. With this configuration of lasers a beam with a wavelength of 254 nm can be produced and directed through window 6 into container 1. This wavelength, which is diffusely produced by germicidal lamps, is known to be effective for promoting the oxidation of organic contaminates in the presence of an oxidant. This apparatus can be operated with a continuous flow of fluid. Alternatively, longer reaction times may be achieved by recirculating the fluid from the dispersing pipes 3a and 3b to the inflow 2 or by holding the fluid in container 1 while continuing oxidant injection and ultraviolet irradiation. The flow rate of the fluid, the rate of oxidant injection and the wavelength of the laser output beam can be adjusted to achieve optimum results, meaning minimum residual contamination in practically short reaction times. The optimum conditions will depend on the degree of initial contamination, the desired level of purification, the nature of the contaminants and the amount of fluid to be treated.

An ultraviolet radiation/oxidation fluid decontamination apparatus is provided which includes a container made of high tensile strength material through which the fluid to be treated flows, a high intensity, directed beam light source, a small ultraviolet transparent window through which the directed beam propagates, and an oxidant injection port. The container interior is lined with a reflective surface which distributes the light throughout the container and a non-sticking surface which prevents fouling of the container. Organic contaminates are oxidized to carbon dioxide, water and other nonharmful products during the fluid treatment carried out by this apparatus.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a complete and reproducible process for obtaining new strains of yeasts for bread making. It also relates to the novel strains of yeast thus prepared as well as to fresh or dried yeast for bread making prepared from said new strains. 2. Description of the Prior Art Quick strains of yeasts are already known which are adapted to maltose--that is to say, enabling the preparation of yeasts which release a large amount of CO 2 with doughs constituted by flour and water--and which remain active with doughs of little sweetness, that is to say, not containing more than 5% by weight of sugar with respect to the flour, namely less than 3.3% by weight with respect to the dough. It is found that these strains exhibit performances which drop appreciably when the sugar content of the dough increases and notably when it exceeds 10% by weight with respect to the flour. Now, such doughs represent a non-negligeable part of bread-making in certain countries. Moreover, these strains, whose use has been generalised in yeast making for about 10 years, are rapidly inhibited as soon as the dough contains significant concentrations of acetic, sorbic or propionic acids or their salts. Acid or sour doughs occur in the manufacture of rye bread, leavened bread and others, whose acidity, corresponding to a pH below 4.7, is contributed by a mixture of about 10-50% by weight of acetic acid and about 50 to 90% by weight of lactic acid and which are rarely sweetened, represent also a non-negligeable part of bread making. Finally, in all countries, there is added to the products of bread making intended to have a long period of preservation or a preservation under difficult conditions, mould-inhibiting agents such as acetic, sorbic, propionic acids and their salts, and this whatever the proportion of sugar contained in the dough. It is known that a bread making yeast resistant to acetic acid, that is to say, whose fermenting power is not inhibited significantly in the presence of undissociated acetic acid, has generally the same property, that is to say, a better resistance, with respect to inhibiting doses of undissociated propionic or sorbic acid. To overcome the inadequacies of the prior art with regard to bread-making yeast strains, it is an object of the invention to provide a process adapted to permit the obtaining, in simple and reproducible manner, of novel strains of yeast adapted to maltose, characterised by the fact that the yeast, both fresh and dried, of which they enable the preparation and of which certain at least constitute novel industrial products, are: either still better adapted to maltose, or active with sweetened doughs, that is to say with dough containing at least 5% by weight of sugar with respect to the flour, or active with acid doughs, or endowed, preferably, with two of the three abovementioned properties and preferably with all three. In order to do this, the specialist in the field has the choice between: on the one hand, modifying the processes of propagation of yeast, that is to say, its processes of cultivation and, on the other hand, obtaining novel strains by mutation and/or hybridation. Modification of the cultivation processes is laborious and difficult to put into practice and often magnifies one property more or less to the detriment of another. Research for novel strains by hybridation and mutation poses complex problems. It is highly uncertain if the objectives and the phenomena in play are not well mastered and if the crossing plans or the mutation process are not clearly defined. It results in any case in the obligation to test thousands even tens of thousands of colonies, which is impossible in practice by means of tests with release of gas under specific conditions (flour, sugar or organic acid mediums), said tests requiring cultivation in a fermenter of some liters as described in Example 1 of French patent application no. 75 20943, the harvesting of this yeast and at least five measurements of gas release according to tests of type A which will be considered below. The problem is complicated by the fact that the results obtained are reproducible with difficulty; for example, a slight modification, difficult to master in the conditions of cultivation can result in considerable variations in respect to the criteria measured. Nevertheless, research for novel strains is theoretically the best solution, all the more as the employment of specific cultivation conditions can only improve, reinforce the natural properties possessed by the hybrids or mutants. The two routes of research are in fact complementary and not concurrent. GENERAL DESCRIPTION OF THE INVENTION The process according to the invention is characterised in that by means of the first and of at least one other screening test selected from a group of screening tests not calling upon any measurement of gaseous release, the desired strains are selected from a group of diploid strains previously prepared either by hybridation, or by mutation of the existing strains, the tests of said group of tests being constituted by: a first test consisting of measuring the mean or average multiplication coefficient of a given strain by following the variation of the optical density of a standard medium seeded by a suspension of cells obtained from this strain, a second test consisting of measuring in the same manner the mean multiplication coefficient of said strain in the presence of an inhibitor acid added to the standard medium, a third test consisting of measuring the maltose adaptation of said strain in the presence of glucose by the determination of the amount of maltose subsisting in a standard medium after a known amount of glucose added to this medium has been completely consumed, a fourth test consisting of measuring the invertase content of said strain, the invertase unit being defined as production of a micromole of reducing sugars in five minutes per mg of yeast dry matter at 30° C. and at pH 4.7, without plasmolysis of the yeast, namely a demi-micromole of invert saccharose, a fifth test consisting of measuring the latent time of said strain, that is to say the delay in the starting of multiplication, by following the variation in the optical density of the yeast suspension applied in the first test after having conferred on this suspension a sugar concentration of at least 20%. In the abovesaid process, for the first test, it is possible to produce a preculture of 48 hours at 30° C. in a test tube containing 10 ml of a medium having the following composition: ______________________________________yeast extract 1%peptone 2% YEP Mediumsaccharose 2%______________________________________ denoted in the following description by the name "YEP medium". The preculture can also be made in other media. A known amount of this preculture serves then for seeding an optical flask containing 30 ml of a medium identical with or equivalent to the YEP medium. The growth curve of the yeast is then established by measurement of the optical density every hour at 600 mμ. From this curve, it is possible to calculate the mean multiplication coefficient μ given by: ##EQU1## where x represents the cellular population at the time t This first test has a double advantage in the sense that it can serve as a control for the other tests and that it permits the elimination of all the diploid strains not having a sufficient multiplication coefficient, that is to say, capable of giving in sufficient yield or of having too low a gaseous release, as for example strains which have been treated too severely during a mutation treatment. Again in the above-mentioned process, for the second test, the inhibitor acid added to the cultivation medium consists of acetic acid or of a mixture of acetic acid and lactic acid in an amount and in proportions such that it inhibits to a ratio comprised between 50% and 90% the growth of a control strain showing on dough containing inhibiting organic acids and/or on sweetened dough, a considerable reduction in its power of CO 2 release. It has, in fact, been found that there existed a non-negligeable probability that the strains which, in a medium containing an amount of acetic acid inhibiting in a large proportion the growth of known quick yeast hybrids adapted to maltose, show a better growth than these hybrids, and exhibit a least fermentation inhibition with acid doughs (more than 50% of chances), or, and are more active and often distinctly more active with sweetened doughs than said quick hybrids, adapted to maltose. Again in the abovementioned process for the third test, the yeast strain is placed in the presence of a sugar solution containing a known amount of glucose and of maltose. The amount of glucose is selected so that it is entirely consumed at the end of the test which lasts generally one hour. At the end of the test, the reaction is stopped by cold centrifugation and the sugar remaining in the supernatant liquid is determined. The percentage of maltose consumed by the yeast is deduced therefrom. It was found that the percentage of maltose consumed generally well manifested the more or less good adaptation of the tested strain to the fermentation of maltose and also the speed of the strain. A modification consists of following as a function of time the disappearance of the glucose and of the maltose added together. The disappearance of the total sugars is followed by determination with anthrone and that of the glucose by specific enzymatic determination, the amount of maltose being determined by difference. It was observed that the strains not adapted to maltose did not ferment, in this test, the maltose as long as glucose remained; on the other hand, the strains adapted to maltose ferment more or less rapidly the maltose even when there is still glucose. The abovesaid test is carried out by starting with a known amount of dry material obtained from the yeast strain tested. This known amount of dry yeast material can for example be obtained by filtration of the yeast present in the optical flask at the end of the first test, or by filtration of an amount of yeast obtained within the scope of a similar shaken culture and by determination of the dry material in this cake, which dry material is generally of the order of 20%. The adaptation to the maltose can also be estimated semi-quantitatively by recovering colonies of tested strains spaced regularly on a petri dish by a filter paper soaked in a maltose solution, for example 0.1 Molar and in Bromo-Cresol Purple acidity type indicator dye and by monitoring the colorimetric change at the end of a given time. This coarse test is a first possible approach, essentially after mutation. In any case, the methods described above must always be employed to refine this first possible selection. Again in the above mentioned process there is indicated, in connection with the fourth test, that the invertase unit may be determined for example in the following manner. It starts with a known amount of dry yeast material of the order of 0.1 to 0.4 mg which can be obtained by filtration of the yeast present in the optical flask at the end of the first test. This amount of dry yeast material is placed in the presence of saccharose at a final 0.1 Molar concentration in a test tube in a buffered medium, buffer acetate at pH 4.7 placed in a water bath at 30° C. At the end of five minutes, the inversion reaction of the saccharose is blocked by the addition of a reactant sodium dinitrosalycilate which serves to determine the reducing sugars formed, by colorimetric reaction. The greater or lesser richness in invertase can also be evaluated semi-quantitatively by colonies of strains tested on a petri dish, by covering the dish with a filter paper soaked in saccharose and the necessary reactant for the enzymatic determination of the glucose formed, by colorimetric reaction (O--dianisidine, for example). This test is a first possible approach, essentially after mutation. It can, in some cases, permit a first very rough selection. In any case, the simple and practical method described above must always be employed to refine this first selection. It has been found that a strong probability exists that all strains of yeast having less than 35 invertase units, preferably less than 30 units and, more preferably still, less than 20 invertase units, are active on sweetened doughs especially if they have given good results in the first test and in the third test. By way of indication it is to be recalled that the hybrids of quick yeast adapted to maltose, employed until now in yeast making, have an invertase content which is always greater than 40. Again, in the above mentioned process, it is pointed out, with respect to the fifth test, that the shorter the latent time, the more likely the tested strain is to be osmotolerant, that is to say, active with sweetened doughs. In conclusion, it is emphasized that the conjugate use of the first and third tests can either permit the selection of strains which are even quicker and better adapted to maltose than those which have been used hitherto, or permit the selection, when it is coupled with at least one of the other tests described, of strains adapted to maltose and more active with sweetened doughs or, preferably, with acid doughs. Thus, it has been found that a selection effected by using in conjugated manner, the first screening test (the criterion taken being that any strain selected should have a multiplication coefficient equivalent to that of the best commercial baker's yeast), the third test (the criterion taken being that any strain selected should have an adaptation to maltose corresponding to an amount of maltose consumed equal to at least 50% of the maltose consumed in the operational method taken with the best strains of commercial yeast adapted to maltose) and the fourth test (the criterion taken being that any strain selected should have an invertase content less than 35 units, preferably less than 30 units, and more preferably still, less than 20 units), leads to strains better adapted to maltose and/or more active with sweetened doughs. All the strains thus selected have novel characteristics with respect to all previously known strains. It has also been found that a selection effected by using in conjugated manner the first screening test (the criterion taken being that any strain selected should have a multiplication coefficient equivalent to that of the best strains of commercial baker's yeasts), the third test, (the criterion taken being that any strain selected should have an adaptation to maltose corresponding to an amount of maltose consumed equal to at least 50% of the maltose consumed by the best strains adapted to maltose) and the second test (criterion taken being that any strain selected should have less inhibition of the culture in the presence of acetic acid added to the standard medium), leads to strains better adapted to maltose and/or more active with acid doughs and/or often equally more active also with sweetened doughs. All the strains thus selected have novel characteristics with respect to all previously known strains. A selection effected by means of a combination of the four first tests described above leads to strains having at least two and mostly three of the following properties: improved adaptation to maltose, better activity with sweetened doughs having from 1 to 20% of sugar, better activity with doughs containing undissociated acetic acid. All the strains thus selected have novel characteristics with respect to all previously known strains. The fifth test (the selection criterion taken being the search for as short as possible a latent time when there is added to the standard medium of the first test an amount corresponding to a concentration of saccharose in the medium of 30%) can serve to confirm the significance of the results of the fourth test (low invertase content). It can also serve, associated with the first test, and preferably also with the fourth test (the selection criterion taken being an invertase content less than 20 units) for seeking strains particularly active with doughs with 10-25% of saccharose. Accordingly and still in the above mentioned process, the hybridation according to the invention consists essentially of systematic crossings of haploids derived from strains of quick saccharomyces cerevisiae adapted to maltose and haploids derived from very slow strains, not adapted to maltose, but well adapted to sweetened doughs and sometimes also to acid doughs belonging to the Saccharomyces genus, and notably to the Saccharomyces cerevisiae species. As indicated above, these strains of quick saccharomyces cerevisiae baker's yeasts adapted to maltose, are well known and are generally those which serve at present for the manufacture of fresh yeast marketed throughout the world. Such yeasts are for example described in British Patents 868 621 (strain ATCC 13 601), 868633 (strain ATCC 13 602), 989247 (strains CBS Ng 740 and Ng 1777), etc. This list of patents and of strains deposited at the collection centres such as ATCC (American Type Culture Collection), the CBS (Centraalbureau voor Schimmel Cultures de Baarn) or NCYC (National Collection of Yeast Cultures Agricultural Research Council's Food Research Institute, Colney Lane, Norwich, Norfolk NR4 7UA, ENGLAND) is not limiting nor complete. Slow yeast-making strains Saccharomyces cerevisiae, other strains of Saccharomyces with an osmotophile character, like for example strains of Saccharomyces rosei, Saccharomyces rouxii, are available at the principal collection centres such as the ATCC, CBS or the NCYC. It has been found that certain slow yeast-making strains, used at other times in Europe, and certain distillery strains, like for example the isolate which is deposited at the NCYC under no. R30 and which is described in French Patent No. 75 20943, were extremely interesting materials for this crossing operation. Sporulation of the starting strains, the obtaining of the haploids, and the conjugation of these haploids are carried out according to the techniques described in Chapter 7 of "Sporulation and Hybridization of Yeasts" by R. R. FOWELL in the book "The Yeasts", volume 1, edited by Anthony H. ROSE and J. S. HARRISON, 1969, Academic Press, London and New York. The hybridation technique adopted between haploids of Saccharomyces Cerevisiae was the mass-mating technique. Micro-manipulation may be the preferred method for crossings in which haploids of other Saccharomyces than Saccharomyces Cerevisiae take part. In this way the strains are obtained which meet the criteria taken in the first and third tests, as well as the criteria taken in one or several of the three other tests. It has been verified that the large majority of yeasts obtained from strains selected by means of the group of tests of the process according to the invention had at different successive stages of cultivation, namely at the three liter cultivation stages, and then cultivation in a pilot fermenter, the calculated fermentative properties, these properties being measured by means of tests A (carried out by means of the BURROWS and HARRISON fermentometer) and tests B (carried out by means of the CHOPIN zymotachygraph) which are described below. Again in the above mentioned process, the mutation according to the invention which constitutes a completely novel route for producing industrial strains of bread-making yeast, which route it has been possible to take due to the group of tests of the same process, consists essentially of a mutagenesis carried out on the haploid or on the diploid and applying mutagenic agents such as ethylmethane sulfonate and N-methyl, N-nitro, N-nitrosoguanidine or NTG, the haploids obtained at the end of the mutagenic treatment being taken utilisable as crossing material in the hybridation operations. Preferably, recourse is had to mutagenesis with NTG resulting in a survival rate comprised between 2% and 80%. The survival rate selected must be higher operating with haploids than when operating with diploids so that these haploids retain their aptitude to be conjugated. The survival rates generally selected for working with haploids have been comprised between 40% and 80%. This being the case, the novel quick strains, adapted to maltose, obtained by the application of the process according to the invention, may be characterized by the fact that they enable the preparation of both fresh and dried yeast, themselves characterized by their release of gas that they give within the scope of a certain number of tests denoted by the references A (A 1 , A' 1 , A 2 , A' 2 , A 3 , A' 3 , A 4 , A' 4 , A 5 , A' 5 ) carried out by means of the BURROWS and HARRISON fermentometer and by the references B (B 1 , B' 1 and B' 3 ) carried out by means of the CHOPIN zymotachygraph and which will be defined below. Test A 1 (fresh compressed yeast) To 20 g of flour incubated at 30° C., is added a weight of compressed yeast corresponding to 160 mg of dry material, this yeast being diluted in 15 ml of water containing 27 g of NaCl per liter and 4 g (NH 4 ) 2 SO 4 per liter; it is kneaded by means of a spatula for 40 seconds, so as to obtain a dough which is placed on a waterbath regulated to 30° C.; 13 minutes after the beginning of kneading, the vessel containing the dough is hermetically closed; the total amount of gas produced is measured after 60, and then 120 minutes; this amount is expressed in ml at 30° C. and under 760 mm of Hg, Test A' 1 (dry yeast) Identical with test A 1 , but prior to kneading, the dry yeast is rehydrated in distilled water, at 38° C.; for this purpose 40% of the volume of water of hydration applied is used; the complement of water, supplemented with 405 mg of NaCl, is added at the end of the 15 minutes of rehydration, Test A 2 (fresh compressed yeast) Test identical with test A 1 , but there is added to the flour 100 mg of saccharose; the total amount of gas produced is measured after 60 minutes, Test A' 2 (dry yeast) Test identical with test A' 1 , but there is added to the flour 100 mg of saccharose; the total amount of gas produced is measured after 60 minutes, Test A 3 (fresh compressed yeast) Test identical with test A 1 , but there is added to the flour 2 g of saccharose; the total amount of gas produced is measured after 60 minutes, Test A' 3 (dry yeast) Test identical with test A' 1 , but there is added to the flour 2 g of saccharose; the total amount of gas produced is measured after 60 minutes. Test A 4 (fresh compressed yeast) Test identical with test A 1 , but to the flour is added 5.5 g of saccharose; the total amount of gas produced is measured after 60 minutes, Test A' 4 (dry yeast) Test identical with test A' 1 , but to the flour is added 5.5 g of saccharose; the total amount of gas produced is measured after 60 minutes, Tests A 5 and A' 5 Tests identical respectively with tests A 1 and A' 1 , with the difference that there is added to the yeast suspension, just before the addition of the latter to the flour, an amount of 0.15 ml of a mixture constituted by 15 g of acetic acid and 80 g of lactic acid, these 0.15 ml being substituted for 0.15 ml of dilution water, Test B 1 (fresh compressed yeast and instant dry yeasts not needing prior rehydration) To 250 g of flour, is added a weight of compressed yeast or instant dry yeast corresponding to 1.6 g of yeast dry material, and 150 ml of salted water (50 g of salt/1.51 of water); it is kneaded for 6 minutes; the temperature of the dough must be 27° C. at the end of kneading; the dough is placed in the apparatus and 6 minutes, measured exactly, after the end of kneading the chamber thermostatted to 27° C. is placed under pressure; the total release recorded on the graph, in ml, is measured after 1 hour and 3 hours, Test B' 1 (dry yeasts requiring rehydration) Tests identical with Test B 1 but prior to kneading, the dry yeast is rehydrated in distilled water at 38° C. (50 ml) for 15 minutes; the complement of water and of salt is added at the end of the 15 minutes of rehydration, Test B' 3 Test identical with test B' 1 , with the difference that there is added to the yeast suspension obtained after dilution of the fresh yeast or after rehydration of the dry yeast, just before kneading, an amount of 2 ml of a mixture constituted by 15 g of acetic acid and 80 g of lactic acid, these 2 ml substituted for 2 ml of diluting water. The novel strains obtained can hence be characterised by the commercial yeasts whose production they permit and which will be defined below. 1. Strains giving fresh yeasts active with sweetened doughs and characterised by the fact that they give rise to: a gas release equal to or greater than 112 and, preferably, to 115 ml of CO 2 in test A 1 in 2 hours, a gas release equal to or greater than 1500 ml of CO 2 in test B 1 in three hours and, preferably, equal to or greater than 135 ml of CO 2 in test A 1 and 1700 ml in test B 1 , a gas release equal to or greater than 53, preferably to 55 ml of CO 2 in 1 hour in test A 2 and, more preferably again, equal to or greater than 60 ml in this test in 1 hour, a gas release equal to or greater than 50 ml of CO 2 in 1 hour in test A 3 and, preferably, equal to or greater than 55 ml in test A 3 in 1 hour, a gas release equal to or greater than 25 ml of CO 2 in test A 4 and, preferably, equal to or greater than 30 ml of CO 2 in 1 hour and more preferably again, equal to or greater than 35 ml of CO 2 , the yeast reaching the preferred values for two of the abovesaid tests being particularly preferred. 2. Strains giving dry yeast active with sweetened doughs and characterised by the fact that they give rise to: a gas release equal to or greater than 98, preferably to 100 ml of CO 2 in test A' 1 in 2 hours, greater than or equal to 1350 CO 2 in test B 1 in 3 hours and, preferably, equal to or greater than 115 of CO 2 in test A' 1 and to 1500 ml of CO 2 in test B 1 in 3 hours, a gas release equal to or greater than 46, preferably to 48 ml of CO 2 in test A' 2 in 1 hour, and, preferably, equal to or greater than 52 ml in test A' 2 , a gas release equal to or greater than 44 ml of CO 2 in test A' 3 and, preferably, equal to or greater than 47 ml of CO 2 in test A' 3 , a gas release equal to or greater than 21 ml of CO 2 in test A' 4 and, preferably, equal to or greater than 26 ml of CO 2 . 3. Strains giving fresh yeast active with acid doughs and characterised by the fact that they give rise to: gas release equal to or greater than 115 ml of CO 2 in test A 1 in 2 hours and equal to or greater than 1500 ml of CO 2 in test B 1 in 3 hours and, preferably, equal to or greater than 135 ml of CO 2 in test A 1 and to 1700 ml of CO 2 in test B 1 , a gas release equal to or greater than 40 ml of CO 2 in test A 5 in 1 hour and, preferably, equal to or greater than 45 ml of CO 2 in test A 5 in 1 hour, a gas release equal to or greater than 900 ml of CO 2 in test B' 3 in three hours and, preferably, equal to or greater than 1000 ml of CO 2 in this test B' 3 in 3 hours. 4. Strains giving dry yeasts active with acid doughs and characterised by the fact that they give rise to: a gas release equal to or greater than 100 ml of CO 2 in test A' 1 in 2 hours, greater than 1350 ml of CO 2 in test B 1 in 3 hours and, preferably, equal to or greater than 115 of CO 2 in test A' 1 and to 1500 ml in test B 1 in three hours, a gas release greater than or equal to 32 ml of CO 2 in test A' 5 in 1 hour and, preferably, equal to or greater than 38 ml of CO 2 in test A' 5 ; a gas release equal to or greater than 750 ml of CO 2 in test B' 3 in 3 hours and, preferably, equal to or greater than 820 ml of CO 2 in test B' 3 . 5. Strains giving fresh yeast, on the one hand, and dry yeast, on the other hand, active with sweetened doughs and with acid doughs and characterised by the fact that the first give rise simultaneously to gas releases shown by the abovementioned fresh yeast, active with sweetened doughs and by the abovesaid fresh yeasts active with acid doughs and the second give rise simultaneously to the releases shown by the abovesaid dry yeasts active with sweetened doughs and by the abovesaid dry yeasts active with acid doughs. In the foregoing, there has generally been denoted by fresh yeasts, those which have a content of dry material of about 28 to 35% and by dry yeasts those which have a content of dry material higher than 92%. The nitrogen content of these yeasts has generally been selected within the following ranges: about 7.5 to 8.5 for fresh compressed yeast, about 7.2 to about 8.2 for dry yeast. Once the strain sought is available, it is possible to prepare the fresh compressed yeast corresponding, having a content of dry matter in the neighbourhood of 28 to 35% by resorting to a conventional propagation scheme adapted to provide fresh yeast stable in preservation and stable on drying. These yeasts can then be dried to about 92% of dry material or more by means of a particularly gentle drying process. Preferably, the cultivation of the yeast is conducted so as to obtain a fresh yeast with 28-35% of dried matter haing the following characteristics: p an amount of budding below 5% and, preferably, less than 1%, cryoscopic lowering of the water external to the yeast below 0.5° C. and, preferably, below 0.3°. It is pointed out that, to measure the cryoscopic lowering of the external water of a fresh compressed yeast, a cream is produced with 100 g of the pressed yeast and 30 g of completely demineralised water, this cream is centrifuged and cryoscopic lowering of the supernatant liquid obtained is measured, for example, by means of a BECKMAN type cryoscope (PROLABO no. 0329 600). The lowering of the freezing point measured is proportional to the amount of gram-molecules of dissolved substances in the external water. If it is desired to obtain very quick yeast, fairly high nitrogen contents are selected 8-8.5% of nitrogen to dry matter, even a little more. If it is desired to obtain yeast having more particular characteristics as for example, stabilty to drying, the following characteristics are rather to be sought: protein content corresponding to the optimum of the strain cultivated taking into account the desired characteristics; this content varies according to the strains and the desired characteristics for the yeast but for relatively quick strains it is of the order of 7.5% to 8% of nitrogen to dry matter or even less; the optimum of the nitrogen content for stability to drying may be defined as being the value above which any increase in this content no longer gives more than a slight gain in activity but, after drying, an additional loss in activity equal to or greater than this gain. This optimum depends much on the strain, on the conditions of culture, on a reference test (with sugar, without sugar). It can only be determined experimentally case by case. It is of course obvious to the specialist that all the values of nitrogen to dry matter given above are only indicative; ##EQU2## Preferably, it will be particularly sought to provide the culture medium with the growth factors of which each strain has a need: biotin, group B vitamins etc. To the yeast intended for drying, is preferably added a fine emulsion constituted by a suitable emulsifier, such as, for example, sorbitol esters, polyglycerol esters in the proportion of 1.5 to 2% of dry yeast matter and if necessary a thickening agent. Yeast intended for drying, of 30-35% dry matter, is extruded through a grid of mesh width 0.5 to 3 mm, and, preferably, 0.5 to 1 mm. It is then dried to about 92% of dry matter or more, preferably to a content of dry matter comprised between 94 and 97% by a particularly gentle drying. This can be a fast pneumatic drying, a fluidised bed drying or a combination of these two methods of drying. Preferably, the drying will be conducted so that the temperature of the yeast does not exceed 30° C. at the beginning of the drying and 40° C. at the end of drying. To enable the invention to be better understood, there are described below, be means of some examples, the production of some strains of yeast according to the invention, the preparation of fresh yeasts and dry yeasts from these strains and the properties of the fresh yeasts and dry yeasts thus obtained. DESCRIPTION OF PREFERRED EMBODIMENTS EXAMPLE 1 Two quick strains, adapted to maltose, stable to drying, deposited by applicants at the N.C.Y.C. under nos. N.C.Y.C. 875 and N.C.Y.C. 876, were sporulated. Two slow strains, very osmotolerant, that is to say, very active with sweetened doughs, deposited by applicants at the N.C.Y.C. under nos. R30 and N.C.Y.C. 877, were sporulated. For each group of strains, ten haploids of mating type a and ten haploids of mating type α, were isolated. By mass-mating each haploid of one group was then conjugated with all the haploids of the opposite mating type of the other group. In this way 196 hybrids were obtained. These 196 hybrids were tested with the first, the second, and the third screening tests and the fourth screening test. The growth curves of the first and second tests were effected in optical flasks, flasks provided with a calibrated tube enabling colorimetric reading without sampling of the medium. The YEP culture medium was composed of 1% yeast extract, 2% of peptone and 2% saccharose and it was seeded with 0.3 to 0.5 ml of a stirred pre-culture of the hybrid to be tested in a liquid medium with 1% of sugar. The second test was practised by adding to the culture medium of the first test a glacial acetic acid in the proportion of 0.13 and 0.14 ml, namely 0.433% and 0.466%. The third and the fourth test were carried out on the yeast harvested by centrifigation or filtration of the culture practised in the scope of the first test. The yeast harvested was washed to remove the amount of sugar from the culture medium, which sugar could falsify the results of the third test. The third test was carried out in an 0.01 M phosphate buffer medium, pH 6.5, the reaction mixture comprising: Yeast: 20 to 25 mg of dry matter Glucose: 4 mg Maltose: 2 mg. The reaction is carried out at 30° C. for one hour and it is arrested by sudden cooling and cold centrifugation. The determination of the supernatant sugar is done by the anthrone colorimetric method. The fourth test is practised on 0.1 to 0.4 mg of dry yeast matter which are placed in the presence of saccharose at a final concentration of 0.1 Molar, in a test tube in a buffered medium with acetate buffer at pH 4.7, placed in a water bath at 30° C. At the end of 5 minutes, the saccharose inversion reaction is blocked by the addition of the reactant with sodium dinitrosalicylate which serves to determine reducing sugars formed, by colorimetric reaction. Within the scope of the first screening test, can be determined the coefficient μ: increase in population per unit time and per unit mass of population of quick commercial yeast strains or starting strains, the control value found being denoted by μ t . Within the scope of the first test, there are eliminated all hybrids for which: μ<0.9μ t . Within the scope of the second test, it is observed that all the quick strains, adapted to maltose employed have a: μ in 0.433% acetic acid <0.4μ t and a μ in 0.466% acetic acid <0.25μ t but that a slow strain, very osmotolerant and rather insensitive to acetic acid like the strain N.C.Y.C. R30, has a μ in 0.433% acetic acid >0.6μ t and a μ in 0.466% acetic acid >0.4μ t . Within the scope of this second test, will be considered as kept for subsequent examination are all strains giving: μ in 0.433% acetic acid >0.55μ t and a μ in 0.466% acetic acid >0.32μ t . Within the scope of the third test, it is observed that quick strains considered as adapted to maltose, consume 60-80% of the maltose present, but that, on the other hand, a slow strain like N.C.Y.C. R.30 consumes lss than 20% of the maltose present. Within the scope of this test, there are eliminated all strains consuming less than 35% of the maltose present and the strains consuming more than 60% of the maltose are retained. The strains consuming between 35% and 60% of the maltose present are only retained if they have been retained according to the criteria of the second test or according to the criteria of the fourth test. In the fourth test, all the strains are kept which titrate less than 35 invertase units and, preferably, less than 30 invertase units and, more preferably, less than 20 invertase units. Within the scope of the selection as described above, 10 hybrids of the 196 obtained by crossing were kept. It is remarkable that the hybrids selected having the following properties: growth curve equivalent to the controls in the first test, adaptation to maltose characterised by a consumption of at least 35% of the maltose present in the second test, that is to say at least 50% of the maltose consumed by the control quick strains adapted to maltose, invertase content less than 35 units and, preferably, less than 30 units and, more preferably, less than 20 units in the fourth test, or/preferably and growth in the presence of acetic acid characterised by a: μ in 0.433% of acetic acid >0.55μ t and/or a μ in 0.466% of acetic acid >0.32μ t , that is to say lesser inhibition in the presence of acetic acid than the control quick strains adapted to maltose, are novel strains for the production of yeast for breadmaking, no strain used in the breadmaking yeast industry combining these three or four characteristics. These ten selected hybrids are then tested by conventional means: cultivation in fermenters of three liters such as described in Yeast Technology, J. White (1954) pages 103 to 106 where the culture medium has a total volume of 1100 ml, the sugar is added in the form of molasses, the air is filtered through a diaphragm of the Millipore type at the rate of 1 m 3 /hour and seeding is carried out by 300 mg of yeast obtained by anerobic cultivation in flasks, culture aerated and stirred on a battery of the New Brunswick Scientific Company of 5 liters of useful volume 3/3.5 liters, then drying the yeast harvested, or culture in a battery of pilot fermenters of 80 liters useful volume such as described in Example 2 of French Patent No. 75 20943, then drying. The cultures at the stage of the WHITE type 3 liter fermenter established that 5 of the 10 hybrids selected have most interesting novel characters. In Table 1 are given the results obtained in the same series of experiments for these 5 hybrids, several hybrids of quick yeast adapted to maltose, taken as controls, and a slow strain, namely N.C.Y.C. R30 which is particularly active. TABLE 1______________________________________Strains Invertase Test A.sub.1used units 1 hour Test A.sub.2 Test A.sub.3 Test A.sub.4______________________________________Controls(hybrids ofquick yeastadapted tomaltose) 45 to 140 57 64 46 8 to 16N.C.Y.C.R30 25 29 46 56 26Hybrid 1 23 52 61 55 24Hybrid 2 37 58 68 51 17Hybrid 3 35 65 72 56 18Hybrid 4 32 56 67 62 23Hybrid 5 29 52 62 60 25______________________________________ After tests in batteries of fermenters of greater volume and after tests in factories, it was hybrids 3 and 5 which were kept and filed at N.C.Y.C. Hybrid no. 3 received the no. N.C.Y.C. 848 and hybrid no. 5 received no. N.C.Y.C. 847. In Table 2 are given the results obtained by these two hybrids in the factory after culture of 100 m 3 leading to a harvest of about 25 tons of fresh yeast, conducted so as to obtain: a nitrogen content in the dry material of about 8%, a P 2 O 5 content in the dry material of about 2.3%, a trehalose content in the dry material of about 13%, a ratio of buds of the order of 1%, a cryoscopic lowering of the external water of the yeast of the order of 0.3° C. By way of comparison there are given the results obtained with a hybrid yeast adapted to maltose and the N.C.Y.C. R30 (table II as regards fresh yeast and table III as regards the dry yeast). TABLE II__________________________________________________________________________ FRESH YEASTS B.sub.1 B.sub.3 'Strain A.sub.1 A.sub.2 A.sub.3 A.sub.4 A.sub.5 1 h 3 h 1 h 3 h__________________________________________________________________________Quick yeasthybrid adapted 55 + 80 = 135 59 49 22 28 350 1700 60 400to maltoseNCYC R 30 37 + 48 = 85 52 56 40 33 260 1200 120 650NCYC 848 60 + 80 = 140 64 53 33 53 420 1780 200 1160NCYC 847 55 + 75 = 130 63 57 37 50 400 1700 250 1200__________________________________________________________________________ TABLE III__________________________________________________________________________ DRY YEASTS B.sub.1 B.sub.3 'Strain A.sub.1 ' A.sub.2 ' A.sub.3 ' A.sub.4 ' A.sub.5 ' 1 h 3 h 1 h 3 h__________________________________________________________________________Quick yeasthybrid adaptedto maltose 48 + 70 = 118 50 41 18 24 300 1500 45 300NCYC R30 32 + 43 = 75 45 47 32 29.5 230 1050 90 500NCYC 848 51 + 68 = 119 53 45 25 43 350 1550 120 830NCYC 847 46 + 61 = 107 53 48 28 38 300 1470 110 830__________________________________________________________________________ The principal taxonomic characteristics of the strains of Saccharomyces Cerevisiae N.C.Y.C. 847 and N.C.Y.C. 848 are shown in Table VI. EXAMPLE 2 To try to obtain strains with a low invertase content, the haploids of slow strains obtained within the scope of Example 1 which seemed most interesting, were crossed with haploids of quick strains adapted to maltose which had undergone a mutation treatment intended to lower their invertase content. The mutagenic treatment was conducted in the following manner: the haploid strain derived from a fresh preculture was reinjected into the culture medium and brought to the exponential phase of growth. The yeast was harvested sterilely by centrifugation and resuspended in Tris buffer of pH 6.6. The final concentration of cells was 10 7 to 10 8 cells per ml. The nitrosoguanidine mutagenic agent was added to a final concentration of 200 to 400 micrograms/ml. The reaction was carried out at 30° C. for a period of 15 to 60 minutes. At the end of the reaction, after dilution with a large amount of salt water, it was centrifuged cold. The treated haploid cells were then brought to a suitable dilution and spread over a gelose medium in a petri dish. According to the treated haploid strain, survival rates of 10 to 80% were obtained. The haploids treated in the treatment which gave a survival rate higher than 40% were retained for screening. As the screening test, to select these haploids, the first test and the fourth test were employed: invertase content less than 20 units. This work was carried out until the production of: 5 mutant haploids of mating type a, 5 mutant haploids of mating type α responding positively to these two tests and for which it has been checked by means of the third test that their adaptation to maltose is retained. These hybrids were crossed with: 6 haploids derived from slow strains of mating type a, 4 haploids derived from slow strains of mating type alpha In this way 50 hybrids were obtained which were tested by means of the first test, the fourth test (invertase content less than 20 units) and the third test as described in example 1. 7 hybrids were selected by means of these screening tests. After WHITE cultivation, tests in NEW BRUNSWICK type fermenters and tests on the factory scale, 1 hybrid was kept. This hybrid was deposited at the N.C.Y.C. under no. N.C.Y.C. 878. The results obtained with this hybrid in test fermenters of the WHITE type of 3 liters, and in factory tests are reported in Table IV. TABLE IV__________________________________________________________________________ Test A Total Test Test Test Test Invertase 1 hour 2 hours A.sub.2 A.sub.3 A.sub.4 A.sub.5__________________________________________________________________________Results of yeasts 15 43 53 61 28with 32% dry matterafter cultivationin WHITE typefermenters.Results of freshyeasts after 5 42 + 70 112 53 61 44 35factory trials.__________________________________________________________________________ Test A.sub.1 ' A.sub.2 ' A.sub.3 ' A.sub.4 ' A.sub.5 '__________________________________________________________________________Results of dry yeastsafter factory trials 37 + 62 = 99 47 48 35 31__________________________________________________________________________ EXAMPLE 3 The most interesting strains obtained in examples 1 and 2 were made to sporulate. The haploids obtained from these noval strains of yeast were crossed with the haploids which were most interesting, that is to say those which led once or, preferably, several times to selected strains. In this way 110 crossings were carried out which led to 21 hybrids retained after selection according to the first test, the fourth test and the third test, all the three applied as in example 1. After trials, 2 hybrids were finally retained and deposited at the N.C.Y.C. under nos. N.C.Y.C. 879 and N.C.Y.C. 880. The results obtained with these two hybrids in WHITE type fermenters of 3 liters in tests are reported in table V below. Their taxonomic characteristics are reported in table VI. The 5 hybrids obtained within the scope of these examples were all identified as Saccharomyces Cerevisiae, by the NCYC, where the hybrids are deposited. TABLE V______________________________________Results with culture Test A.sub.1in WHITE type in 1 Test Testfermenters Invertase hour Test A.sub.2 A.sub.3 A.sub.4______________________________________N.C.Y.C. 879 21 48 58 63 28N.C.Y.C. 880 16 42 54 64 31______________________________________ These two strains N.C.Y.C. 879 and 880 have properties close to those of strain N.C.Y.C. 878, that is to say they are quicker in all the tests than N.C.Y.C. R30 including Test A 4 corresponding to a very sweet dough. EXAMPLE 4 Throughout the work described in examples 1 to 3, it became recognisable that a certain number of haploids were of particular interest leading to selected hybrids and recognised as having interesting novel properties. 5 of these particularly active haploids were deposited at the N.C.Y.C. These were the haploids: ______________________________________Ha 1 haploid of mating type a which has received no.N.C.Y.C. 881Ha 2 haploid of mating type a which has received no.N.C.Y.C. 882Hα3 haploid of mating type α which has received no.N.C.Y.C. 883Hα4 haploid of mating type α which received no.N.C.Y.C. 884Hα5 haploid of mating type α which has received no.N.C.Y.C. 885______________________________________ These haploids were all obtained by sporulation of Saccharomyces Cerevisiae strains. These haploids cultivated in WHITE type fermenters gave the following results: ______________________________________ contentInvertase 1 hourA.sub.1 inTest 1 hourA.sub.4 inTest ##STR1##______________________________________Ha.sub.118 41 29 121Ha.sub.211 29 17 109Hα.sub.385 50 13 75Hα.sub.4 33 15 89Hα.sub.513 26 35 139______________________________________ The two first haploids Ha 1 (N.C.Y.C. no. 881) and Ha 2 (N.C.Y.C. no. 882) were particularly remarkable: since they have quick characters, that is to say adaptation to maltose, and osmotolerant, that is to say adaptation to high sugar content, since they impose the low invertase characteristic after conjugation, that is to say they give systematically diploid strains with low invertase. They gave interesting results when they were conjugated with haploids derived from quick yeasts as well as when they were conjugated with haploids derived from slow yeasts. The two haploids Hα 3 (N.C.Y.C. no. 883) and Hα 4 (N.C.Y.C. no. 884) are interesting and act as examples of haploids derived from non-osmotolerant quick yeasts. Haploid Hα 5 is a good example of a haploid having characters of very good adaptation to sweetened doughs; haploid Hα 5 has N.C.Y.C. no. 885. TABLE VI Results of identification tests carried out by the NCYC (National Collection of Yeast Cultures) on the deposited strains Indication of some particular results on each strain Growth Identi- Size of cells in microns Number of Galactose Assimilation in medium Strains fication Liquid medium Solid medium ascospores ferment- α Methyl- without tested result 24 h 72 h 72 h per ascus ation Trehalose Melezitose Inulin Erythrol glucoside vitamines NCYC 847 Saccharomyces (3.5-5) × (2-5) × (2-4) × 1 to 4 + + + + - + - Cerevisiae (6.5-9) (3.5-7.5) (3-7) latent NCYC 848 S accharomyces (2.5-4.5) × (3-4.5) × (2.5-4.5) × 1 to 4 + + + + - + weakly + Cerevisiae (4.5-6.5) (4-7) (3-8) NCYC 873 Saccharom yces (3-5) × (2.5-5) × (2-4) × 1 to 4 + + + + - + - Cerevisiae (5-8) (4-6) (4-8) NCYC 879 Saccharomyces (3-5.5) × (2-6) × (3-5) × 1 to 4 + + + + - + ± Cerevisiae (4-7) (3-8.5) (3-7) NCYC 830 Saccharomyces 2 to 4 + + + + - + ± Cerevisiae latent NCYC 875 Saccharomyces (3.6-6) × (1.5-5.5) × 1 to 4 + + + + - + - Cerevisiae (4-8) (3.5-8) latent latent latent NCYC 876 Saccharomyces (3-7) × (3-5) × 1 to 4 + + + + - ± - Cerevisiae (4-10) (4-11) latent latent NCYC 877 Saccharomy ces (2-4.5) × (1.5-4.5) × 2 + + + + - + weak Cerevisiae (3-6) (2.5-9) latent latent NCYC R 30 Saccharomyces (1.5-8) × (1.5-8) × (2.9-8) × 1 to 2 + + + - - + - Cerevisiae (2-7) (2-6) (2.5-7) 3 weeks Remarks: The nine strains described have been characterised as belonging to the Saccharomyces Cerevisiae species. The other characters described in this table are secondary characters, without technological significance. Their reproductibility within the scope of the tests practised (J.LODDER tests) is not always ensured. The latter example shows that the screening tests described lead rapidly to defining particularly active haploids, which can impose the desired characters such as for example low invertase content. These haploids, due to the fact that they have led once or preferably several times to selected diploid strains constitute a genetic starting material which is particularly interesting. It is possible to characterize them by means of conventional tests according to their properties as haploids and in a more advantageous way according to the properties they confer on the diploids after crossing. Whatever the embodiment adopted there are thus provided: on the one hand, novel strains of yeasts, on the other hand, fresh and compressed yeasts obtained from these novel strains and constituting novel industrial products, these novel strains as well as the fresh and dried yeasts derived therefrom, having, with respect to those existing hitherto, numerous advantages explained in the description. The invention relates also, by way of novel industrial products, to the breadmaking products by means of the fresh yeasts and the dry yeasts produced by means of the novel strains of yeasts obtained. It is self-evident and as is already consequent upon the foregoing, the invention is in no way limited to the embodiments and adaptations which have been more especially envisaged; it encompasses, on the contrary, all modifications.

A complete and reproducible process for producing novel strains of yeast, comprises making a first screening test and at least one other screening test selected from a group of screening tests which do not resort to any measurement of gas release, selecting by means of said first and at least one other said screening test the desired strains from a group of diploid strains prepared previously either by hybridation, or by mutation of existing strains. The tests are as follows: A first test consists of measuring the average multiplication coefficient of a given strain by following the optical density variation of a standard medium seeded by a suspension of cells obtained from this strain. A second test consists of measuring in the same manner the average multiplication coefficient of the said strain in the presence of an inhibitor acid added to the standard medium. A third test consists of measuring the maltose adaptation of said strain in the presence of glucose by determining the amount of maltose subsisting in a standard medium after a known amount of glucose added to this medium has been completely consumed. A fourth test consists of measuring the invertase content of said strain. A fifth test consists of measuring the latent time of said strain. The hybridation can consist of systematic haploid crossings derived from quick Saccharomyces Cerevisiae strains adapted to maltose and haploids derived from very slow strains not adapted to maltose, but well adapted to sweet doughs and sometimes also to acid doughs.

This application is a division of application Ser. No. 09/928,183 filed Aug. 10, 2001, now allowed. BACKGROUND OF THE INVENTION 1 Field of the Invention The present invention is broadly concerned with improved systems for enhancing oil recovery by increasing the efficiency of injection wells. More particularly, the invention is concerned with a method and corresponding apparatus for operating an injection well having a well bore extending downwardly through geographical strata with higher and lower permeabilities respectively, wherein a downhole booster pump is employed to generate higher and lower pressure output streams which are directed to the lower and higher permeability strata. 2. Description of the Prior Art When hydrocarbon producing wells are drilled, initial hydrocarbon production is usually attained by natural drive mechanisms (water drive, solution gas, or gas cap, e.g.) which force the hydrocarbons into the producing well bores. If a hydrocarbon reservoir lacks sufficient pore pressure (as imparted by natural drive), to allow natural pressure-driven production, artificial lift methods (pump or gas lift, e.g.) are used to produce the hydrocarbon. As a large part of the reservoir energy may be spent during the initial (or “primary”) production, it is frequently necessary to use secondary hydrocarbon production methods to produce the large quantities of hydrocarbons remaining in the reservoir. Water flooding is a widespread technique for recovering additional hydrocarbon and usually involves an entire oil or gas field. Water is injected through certain injection wells selected based on a desired flood pattern and on lithology and geological deposition of the pay interval. Displaced oil is then produced into producing wells in the field. Advancements in secondary hydrocarbon producing technology has led to several improvements in waterflood techniques. For example, the viscosity of the injected water can be increased using certain polymer viscosifiers (such as polyacrylamides, polysaccharides, and biopolymers) to improve the “sweep efficiency” of the injected fluid. This results in greater displacement of hydrocarbons from the reservoir. The ability to displace oil from all the producing intervals in a hydrocarbon reservoir is limited by the lithological stratification of the reservoir. That is, there are variations in permeability in different geological strata which allow the higher permeability zones to be swept with injected fluid first while leaving a major part of the hydrocarbon saturation in the lower permeability intervals in place. Continued injection of flooding fluid results in “breakthrough” at the producing wells at the high permeability intervals which can render continued injection of the flooding medium uneconomical. A number of approaches have been used in the past to increase the efficiency of injection well practice and to avoid “breakthrough.” This has involved use of gel treatments to decrease the permeability of a higher permeability strata and thereby improve the sweep efficiency. Attempts have also been made to use polymer gels having selective penetration properties which will preferentially enter high permeability strata. However, these polymers are rare and expensive. SUMMARY OF THE INVENTION The present invention is broadly directed to systems for operating injection wells having a well bore extending downwardly through geological strata or zones having higher and lower fluid permeabilities, and includes the steps of injecting a fluid into the well bore at a pressure P i , and using the injected fluid to generate first and second higher and lower pressure output streams at pressures P h and P l , respectively, whereupon such streams are directed out of the well bore and into the appropriate geological stratum. In preferred forms, the injected fluid is directed to a fluid-actuated downhole engine and pump assembly, and a first portion of the injected fluid is delivered to the engine which creates work with consequent reduction in the pressure of the first fluid portion to a level below the initial pressure P i . Some of the created work is transferred to the pump to generate the high pressure output stream. A second portion of the injected fluid is delivered to the pump and is pressurized therein, the pressurized pump output comprising at least a part of the high pressure output stream. In practice, the engine and pump assembly is located within the well bore proximal to the strata to be treated, typically by placing the assembly within a tubing string. In order to permit passage of the output streams through the geological strata, the well casing is divided with appropriately located and sized output openings. The preferred engine and pump assembly includes a primary block having a valve chamber, an engine piston chamber, a pump piston chamber, an injected fluid inlet, and high and low pressure fluid delivery outlet openings. The primary block also includes an elongated operator shaft extending along the length of the block from the valve chamber and through the engine and piston pump chambers. This shaft supports an engine piston slidable within the engine chamber and a pump piston slidable within the pump piston chamber. A movable valve member is also located within the valve chamber. In order to direct the incoming injected stream and deliver the desired outputs, the primary block has an injected fluid passageway system operably coupling the valve chamber and the engine piston chamber for alternate delivery of injected fluid into the engine piston chamber on opposite sides of the engine piston, in response to the location of the valve member. This injected fluid passageway system also couples the injected fluid inlet and the pump piston chamber for alternate delivery of injected fluid to the pump piston chamber on opposite sides of the pump piston. The injected fluid passageway system is in communication with the low pressure fluid delivery opening, whereas the high pressure fluid delivery opening of the block is in operative communication with the pump piston chamber. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional, partially fragmentary view illustrating the preferred injection well assembly of the invention positioned within a well bore adjacent geological strata of higher and lower fluid permeabilities and operable to generate high and low pressure output streams for delivery into the strata; FIG. 2 is an enlarged, somewhat schematic vertical sectional view depicting the internal construction of the engine and pump assembly used in the injection well assembly, and illustrating the engine and pump assembly at the beginning of the upstroke thereof; FIG. 3 is a view similar to that of FIG. 2, but illustrating the engine and pump assembly at the beginning of the downstroke thereof; FIG. 4 is a block diagram schematically illustrating the injection fluid flow to the engine and pump assembly, as well as the higher and lower pressure output streams therefrom; and FIG. 5 is a block diagram schematically illustrating a prior art injection and pump assembly used in production wells to assist in recovery from the production wells. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to the drawings, and particularly FIG. 1 an injection well assembly 10 is illustrated in use within a well bore 12 extending downwardly through the earth 14 and through a geological strata 16 and 18 of higher and lower permeability, respectively. Broadly speaking, the well assembly 10 includes a well casing 20 , an elongated, sectionalized tubing string 22 ending in a tubing nipple 24 , and a fluid-actuated engine and pump assembly 26 telescoped within nipple 24 . In more detail, casing 20 is essentially conventional sectionalized well casing, but includes a first series of apertures 28 adjacent higher permeability strata 16 , and a second series of apertures 30 adjacent low permeability strata 18 . Tubing string 22 is also conventional and is made up of a number of end-to-end interconnected tubular sections 22 a as well as nipple 24 presenting an open outlet end 32 . As illustrated, nipple 24 is threadably secured to the next adjacent section 22 a , and has a series of circumferentially spaced outlet slots 34 . String 22 is positioned within casing 20 by means of vertically spaced apart packing rings 36 . The inner face of nipple 24 has appropriate grooves 38 and connectors 39 to insure proper positioning of assembly 26 therein. Although nipple 24 is illustrated in the drawing figures as being disposed at the lower terminal end of tubing string 22 , additional tubing sections can be coupled to the lower end of nipple 24 and extend downwardly therefrom. Referring now to FIGS. 2 and 3, engine and pump assembly 26 has a primary block 40 , an upper inlet block 42 , a lower cap block 44 , and an outer tubular wall 46 coupled with cap block 44 and extending upwardly past block 42 . Primary block 40 includes, from top to bottom, an injection fluid inlet 48 , a valve chamber 50 , a bore section 52 , an engine piston chamber 54 , a bore section 56 , a piston pump chamber 58 , a high pressure fluid chamber 60 and a high pressure outlet chamber 62 . Additionally, block 40 has an injected fluid passageway system broadly referred to by the numeral 64 and made up of: a passageway 66 extending from inlet 48 downwardly and communicating with an annular passageway 68 formed between the outer surface of block 40 and wall 46 ; upper and lower passageways 70 and 72 in communication with passageway 68 and extending to a point above and below chamber 58 ; a passageway 74 extending between the upper end of valve chamber 50 and communicating with the upper end of engine piston chamber 54 ; and a passageway 76 extending from valve chamber 46 to communication with engine piston chamber 54 adjacent the lower end thereof. Block 40 further has a low pressure fluid passageway system including a dogleg passageway 78 extending between valve chamber 50 and an annular passageway 80 formed between the outer surface of block 40 and wall 46 ; and a passageway 82 extending between the lower end of valve chamber 50 and communicating with passageway 80 . Finally, block 40 has high pressure fluid outlets 83 and 83 a respectively extending from the upper and lower ends of chamber 58 and communicating with chamber 60 . It will be observed that annular passageway 68 and 80 are separated by an intermediate sealing ring 84 , whereas a lower sealing ring 86 defines the bottom extent of passageway 68 and an upper sealing ring 88 defines the upper boundary of passageway 80 . A shiftable operator 90 is housed within block 40 and extends between upper valve chamber 50 and lower piston pump chamber 58 . Operator 90 includes an elongated shaft 92 having a continuous axial bore 94 . A pair of spaced apart recesses 96 and 98 are formed in the upper end of shaft 92 and are important for purposes to be described. Shaft 92 also supports an engine piston 100 which is slidable within chamber 54 and a pump piston 102 slidable within chamber 58 . It will be noted that a cup-like injection fluid-retaining cup member 104 is affixed to the upper surface of chamber 60 and receives the lowermost end of shaft 92 . The valving system within block 40 includes a shiftable, annular valve member 106 situated within chamber 50 . Valve member 106 includes an upper, annular recess 108 formed in the outer sidewall thereof, as well as a lateral bore 110 . Valve member 106 is vertically shiftable within chamber 50 , with the lower end of valve member 106 located outboard of bore section 52 . The valving system further includes a check valve assembly 112 adjacent piston pump chamber 58 . Specifically, a pair of upper check valves 114 , 116 are located above chamber 58 and in communication therewith. Check valve 114 also communicates with passageway 70 , while check valve 116 communicates with passageway 83 . A pair if lower check valves 118 , 120 are adjacent the bottom of chamber 58 and communicate with the latter as well as passageways 72 and 83 a , respectively. Engine and pump assembly 26 is located within nipple 24 by conventional means, including a pair of sealing rings 122 , 124 located on opposite sides of output slots 34 . Rings 122 , 124 are also located on opposite sides of a series of openings 126 provided through tubular wall 46 . Inlet block 42 is positioned above primary block 40 and includes an elongated, a central inlet passageway 128 which communicates with inlet 48 of primary block 40 . Although not shown in FIGS. 2 and 3, it will be understood that passageway(s) are provided throughout the entire tubing string 22 so as to permit injection of fluid. Lower cap block 44 includes a caged ball check valve 130 including an apertured housing 132 and a check ball 134 captively retained within housing 132 . Housing 132 is concentric with a pressurized fluid outlet port 136 formed through cap block 44 . The principle operation of the preferred injection well assembly 10 can be understood from a consideration of FIG. 4 . That is, injection fluid at pressure P i is delivered to engine and pump assembly 26 , with a first portion of the injection fluid being directed to the engine for operation thereof, whereas a second portion of the injection fluid is directed to the pump in order to pressurize the second portion. Thus, engine and pump assembly 26 produces two output streams, namely an output stream of pressure P l (which is lower than P i ) from the engine, and an output stream of pressure P h (which is higher than P i ) from the pump. The preferred engine and pump assembly 26 is a modified version of an assembly 138 illustrated in FIG. 5 . Such prior art equipment is used in production wells (rather than injection wells) and is operated by injection fluid at pressure P i , producing a lower pressure engine output stream at pressure P o . The engine in turn operates the pump which pumps well fluid at an inlet pressure of P w and an outlet pressure of P h (P h being higher than P w ). In normal practice, the output streams from the engine and pump are comingled to yield a single output stream of intermediate pressure between P o and P h . The detailed operation of injection well assembly 10 is best understood from a consideration of FIGS. 2 and 3. FIG. 2 depicts engine and pump assembly 26 at its lowermost position, at the start of the upstroke, whereas FIG. 3 depicts the assembly at its uppermost position, at the beginning of the downstroke. In the ensuing discussion, it will be assumed that the assembly 26 is fully primed and is operating normally. Referring first to FIG. 2, at the beginning of the upstroke, the injection fluid at pressure P i is present in the following: inlet passageway 128 , inlet 48 , bore 94 of shaft 92 , cup member 104 , valve chamber 50 between the valve and adjacent portions of shaft 92 , the lower righthand generally L-shaped section of the valve chamber 50 located below valve member 106 , the lower lefthand region of valve chamber 50 located below valve member 106 , passageway 66 , annular passageway 68 between sealing rings 84 and 86 , lateral passageways 70 and 72 , check valve 118 and the area within chamber 58 below piston 102 , lateral valve bore 110 , passageway 76 and the region within chamber 54 below piston 100 . Low pressure fluid at pressure P l is present in the following: passageway 74 and the region of chamber 54 above piston 100 , passageway 82 and annular passageway 80 between sealing rings 84 and 88 , dog-leg passageway 70 , openings 126 , the annular space between sealing rings 122 , 124 , and outlet slots 34 . Finally, high pressure fluid at pressure P h is present in the following: the region of chamber 58 above piston 102 , check valves 114 , 116 and 120 , passageways 83 and 83 a , chambers 60 and 62 , check valve 130 , the region below the assembly 26 , and in the annular space between tubular wall 46 and nipple 24 up to the level of seal 124 . As the injection fluid is delivered to engine piston chamber 54 , the piston 100 is moved upwardly, owing to the fact that the fluid above the piston 100 is at the lower pressure P l below P i . This upward movement of the piston serves to eject the low pressure fluid through passageways 74 and 78 for ultimate delivery out through slots 34 . At the same time, because pistons 100 and 102 are coupled, piston 102 moves upwardly to eject the high pressure fluid above the piston 102 through conduit 83 to be finally outputted through check valve 130 . In this respect, the imbalance of forces created by differential pressures and/or differential areas on lower and upper pistons 102 , 106 together with the direct coupling of the two pistons allows the high pressure fluid to be ejected in this manner. At the top of the stroke, engine and pump assembly 26 assumes the position illustrated in FIG. 3 . It will be observed that in this position valve member recess 108 serves to communicate passageway 76 and passageway 78 and that bore 110 is shifted out of communication with passageway 76 . In this uppermost position, the injection fluid at pressure P i is present in the following: inlet passageway 128 , inlet 48 , shaft bore 94 and cup member 104 , the inner free volume of the valve chamber 50 between the inner valve surfaces and shaft 92 including bore 110 , passageway 66 and annular passageway 68 , upper and lower passageways 70 and 72 , check valve 114 and the region within chamber 58 above piston 102 , passageway 74 and the region within chamber 54 above piston 100 . The lower pressure fluid at pressure P l is present in the following: the region within chamber 54 below piston 100 , passageway 76 , recess 108 , dog-leg passageway 78 , annular passageway 80 , openings 126 , the annular region between seals 122 and 124 , and slots 34 , passageway 82 and recess 98 . The higher pressure fluid at pressure P h is present in the following: the region within chamber 58 below piston 102 , check valves 116 , 118 and 120 , passageways 83 and 83 a , chambers 60 and 62 , outlet port 136 , check valve 130 and the region below the assembly 126 , and the annular space around assembly 26 up to seal 124 . During the downstroke, the lower pressure fluid at pressure P l is delivered through passageway 76 , recess 108 , dog-leg passageway 78 , openings 126 and slots 34 . At the same time, pressurized fluid at pressure P h is delivered through passageway 83 a for ultimate passage through the check valve 130 . Cycling of the assembly 26 as described above thus creates, both during upstroke and downstroke, a low pressure P l output delivered through slots 34 and a high pressure P h output delivered through check valve 130 . Again referring to FIG. 1, it will be seen that these respective outputs pass through apertures 28 and 30 into strata 16 and 18 . It should be understood that the system described above can be easily reconfigured to accommodate situations in which the lower permeability strata is located above the higher permeability strata. In such a scenario, the entire engine and pump assembly can simply be physically inverted or, alternatively, the flow of the injection fluid in the assembly can be re-routed so that the high pressure fluid exits at a point above the low pressure fluid. The preferred forms of the invention described above are to be used as illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention. The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.

An apparatus and method for enhancing oil recovery through improved injection well performance is provided, wherein a fluid is injected into the well bore at a pressure P i , and a downhole fluid-actuated engine and pump assembly is employed as a booster in order to generate a high pressure output at pressure P h greater than P i and a low pressure output at pressure P l lower than P i ; the respective output streams are directed to lower and higher permeability geological strata adjacent the well bore in order to increase production.

This is a continuation-in-part of application Ser. No. 09/174,858, filed Oct. 19, 1998 now abandoned, which is a continuation-in-part of U.S. Ser. No. 09/075,067 filed May 8, 1998, now abandoned, which is a continuation-in-part of U.S. Ser. No. 08/947,530 filed Oct. 2, 1997, now abandoned. BACKGROUND OF THE INVENTION U.S. Pat. No. 4,422,887 to Spitzer et al discloses aerosol synthetic polymer—liquefied propellant compositions which when expelled from an aerosol container form cold pad polymeric foamed structures whose temperature is initially at least 30° C. below the ambient temperature at which the cold formed structure is formed, said formed structures containing open and/or closed cells which may contain an additive which is deposited in the pores and/or walls of the foamed structure as the foamed structure is formed. The aforedescribed prior art aerosol compositions when expelled on a surface exert a pronounced cooling effect on said surface until the propellant component thereof is completely evaporated. The essential ingredients of the aerosol compositions of the above-mentioned U.S. Pat. No. 4,422,887 are: a. a film-forming synthetic polymer in an amount within the range from about 2% to about 30% by weight of the composition; b. at least one liquefied propellant boiling below −10° C.; c. the total propellant being in an amount within the range from about 50% to about 90% by weight of the composition; and having a heat vaporization of at least 55 calories per gram; the propellant being capable of dissolving the synthetic polymer at least in the presence of a co-solvent that is soluble in the propellant and in solutions of the synthetic polymer in the propellant at ambient temperature; and d. at least one nonsolvent that is soluble in the propellant but in which the synthetic polymer is insoluble in an amount within the range from about 1% to about 85% by weight of the composition; the composition forming on volatilization of propellant at ambient temperature a coherent formed structure containing open and/or closed cells, and having a temperature at least 30° C. below ambient temperature. SUMMARY OF THE INVENTION The present invention relates to an aerosol composition consisting essentially of the ingredients of an ointment-liquefied propellant composition which when expelled from an aerosol container onto damaged tissue provides a cold ointment which exerts a therapeutic effect on said tissue in contact therewith. The cooling effect provided by the expelled composition of this invention is controlled so as to provide relief of pain for a desirable period of time but not too cold to cause discomfort or tissue damage. Thus, an object of this invention is to provide a therapeutic ointment composition which when expelled from an aerosol container is cold enough to provide a cooling effect for pain relief but not too cold as to cause discomfort to damaged tissue to which the ointment is applied, said ointment also exerting a therapeutic effect on damaged tissue in contact therewith. A further object is an ointment that can deliver appropriate medication as well as a cooling effect where it is applied. Another object of the invention is to provide a cold ointment for the temporary relief of hemorrhoids which when applied to the swollen inflamed tissue provides a cooling effect and quickly relieving pain and itching as well as effecting shrinking of swollen inflamed tissue. A still further object of the invention is an ointment for the treatment of sunburn. Another object of the invention is a cold anti-itch ointment as well as one that provides relief from arthritic pain. Another object of the invention is an antifungal ointment. An object of this invention is an antibacterial ointment. An additional object of the invention is to provide a cold ointment that is initially unctious, but dries to leave a deposit that is neither greasy nor oily. More particularly, the present invention relates to novel aerosol compositions that enhance the therapeutic action of an ointment by instantly producing, upon topical application thereof, a sustained cooling effect which provides fast relief from pain and itching as well as a tendency to shrink swollen, inflamed tissue in advance of the slower action of any medication present in the ointment, said aerosol composition consisting essentially of from about 10 to about 60 percent by weight of ointment ingredients and from about 40 to about 90 percent by weight of liquefied propellant that is predominantly a non-polar propellant, i.e., at least about 80% by weight of the non-polar propellant and where the sum of the ointment ingredients and the propellant equals 100 percent by weight of the composition. In another embodiment, applicants' invention is directed to a therapeutic aerosol composition for topical use consisting of (a) from about 10 to about 60 percent by weight of the ingredients of an ointment and (b) from about 40 to about 90 percent by weight of liquefied propellant, where at least about 80 percent by weight of the liquefied propellant is a non-polar propellant or mixture of non-polar propellants selected from the group consisting of a hydrocarbon propellant and a fluorocarbon propellant and the sum of ingredients from (a) and (b) equals 100 percent by weight of the composition, the composition when expelled from an aerosol device containing the composition depositing as an ointment having a solid or semi-solid consistency and a temperature between about −5° C. and +5° C. Preferably, the ointment ingredients constitute from 35 to 100 percent by weight of an oil phase and from 0 to about 65 percent by weight of an aqueous phase based on the weight of the ointment ingredients and the oil phase of the ointment does not flow below about 35° C. The oil phase includes ingredients selected from the group consisting of oils, and oil soluble ingredients, the oil soluble ingredients including adjuvants, topical therapeutic agents, oil soluble emulsifiers, and thickening agents for the oils and oil soluble ingredients, where the oils and oil-soluble ingredients are soluble in the propellant. The aqueous phase includes water, water-soluble emulsifying agents and may also include topical therapeutic agents, humectants and alcohols. Also, the present invention relates to a novel method for enhancing the therapeutic effect of a solid or semi-solid ointment which consists of dissolving and/or dispersing: (a) from about 10 to about 60 percent by weight of an ointment that contains an oil phase and may contain an aqueous phase in the form of an emulsion, where the oil phase of the ointment does not flow below about 35° C., in (b) about 40 to about 90 percent by weight of a liquefied propellant that is at least 80 percent non-polar propellant in an aerosol container, whereby a solid or semi-solid deposit is formed when a portion of the composition is expelled and this deposit placed in contact with injured tissue it provides instant relief from pain and itching as the result of its sustained cold, thereby enhancing the performance of the ointment with its slower action medications. The compositions used in the practice of this invention consist essentially of an ointment, i.e., a solid or semisolid component, dissolved and/or dispersed in a liquefied propellant in a suitable aerosol container. The product is expelled from the aerosol container either as a deposit confined to a small area or as a spray covering a wider area, depending on the application. Thus, to relieve hemorrhoids the deposit should be confined to a small area, while to relieve sunburn a wider area is likely to be more convenient. The expelled therapeutic composition for this invention will feel cold due to the evaporation of the propellant. A substantial portion of the propellant that is expelled should initially be part of the deposit, so that there is a continuing cooling action as the propellant gradually evaporates. It is also important that the deposit have a comparatively high density and that it be applied thickly. The temperature of the expelled deposit should be initially in the range of about −5° C. to about +5° C. In this range the deposit can have the therapeutic effects that are the objects of this invention while not being so cold as to cause pain or tissue damage. Suitable liquefied nonpolar propellants that can be used in aerosol compositions of this invention to obtain a deposit falling within this temperature range include the hydrocarbon propellants, e.g., n-butane, isobutane and propane; the fluorocarbon propellants, e.g., 1,1-difluoroethane; and mixtures of these liquefied nonpolar propellants. It has now been found that n-butane is the preferred propellant for use in the compositions of this invention. n-Butane has a vapor pressure of 17 p.s.i.g. and a boiling point of −0.5° C. and will tend to maintain the deposit at about that temperature. If the deposit gets much cooler, further cooling by evaporation will slow substantially. The deposit will remain in the required temperature range until the proportion of n-butane in the deposit has become quite low. If a significant amount of liquefied propellant remains with the deposit when it reaches the substrate, the temperature of the deposit will approximate the boiling point of the propellant. Once it reaches that temperature, the rate of evaporation will slow and absorption of heat from the substrate will prevent it from falling much lower. One reason for preferring n-butane is that a deposit containing it is not likely to become objectionally cold. In contrast, isobutane with a boiling point of −11.7° C. is likely to be unpleasantly cold, if the deposit contains a significant amount of liquefied isobutane. A related reason for preferring n-butane is that it has a lower vapor pressure than the more widely used liquefied propellants: isobutane and propane. The lower vapor pressure assures that less propellant will be lost through evaporation as the exudate travels from the aerosol valve to the substrate upon which it is to be deposited. However, for those products that are likely to be used at lower ambient temperatures, where n-butane does not provide sufficient pressure to expel the composition properly, it is advantageous to combine n-butane with a lesser amount of a higher vapor pressure propellant, e.g., isobutane, propane, 1,1-difluorethane or dimethyl ether. However, higher vapor pressure (lower boiling point) propellants can be used under conditions when little if any liquefied propellant remains with the deposit when it reaches the substrate so that the temperature of the deposit is in the required range of −5° C. to +5° C. This can be done by reducing the percent propellant in the composition. A beneficial feature is that the higher the vapor pressure (lower the boiling point) of the propellant, the greater the tendency to flash off before reaching the substrate. Nonetheless, in general, the higher vapor pressure propellants are not as effective as n-butane, the preferred propellant. The distance of the spray path as well as the characteristics of the package play a role in determining how much propellant will be lost as the exudate travels to the substrate upon which it will be deposited. It is evident that the longer the spray path, the more propellant will be lost by evaporation before reaching the substrate and the less propellant will be available for sustained cooling. It has also been found that restrictions in the delivery system also promote early evaporation of propellant by reducing the flow rate of the exudate. However, with some compositions a restricted delivery system is beneficial, since it results in a heavier-bodied deposit. Also, where layering of the composition occurs within the container, it is advantageous to employ a capillary dip tube, i.e., a dip tube with an inside diameter of 1 mm., to minimize the amount of separated material that is released after first shaking the container. Shaking is not effective in mixing material that is in the dip tube. The dynamic physical characteristics of the composition play an important role in determining the amount of propellant in the deposit and the amount of time it will remain in the deposit to provide sustained cooling. The aerosol compositions of this invention consist of the ingredients of an ointment that generally contains a thickening agent in a solution of an oil, and often one or more medicinal ingredients, dispersed and/or dissolved in an appropriate propellant so that the expelled deposit is initially in the range of about −5° C. to about +5° C. As product is expelled there is some loss of propellant accompanied by cooling of the exudate. If the deposit had been a liquid rather than an ointment, it would have spread rapidly whereby expiration of the propellant would occur too quickly and one would not obtain the desired sustained cooling effect. The compositions of this invention deposit as solids or semi-solids. The thickness of the deposit helps to provide sustained therapeutic cooling. It has been found that the oil phase of the ointment should have a flow temperature that is at least about 35° C.; otherwise, the deposit will liquefy readily and not provide sufficient cooling. It is advantageous that the flow temperature of the oil phase of the ointment not exceed about 60° C., otherwise manufacture becomes more difficult. The preferred compositions contained in an appropriate aerosol container in accordance with this invention contain from about 10 to about 60 percent by weight of the ingredients of an ointment and from about 40 to about 90 percent by weight of a propellant that is at least 80% by weight n-butane. Also preferred are aerosol compositions of this invention that consist essentially of from about 50% to about 75% by weight of a non-polar propellant or mixture of non-polar propellants and 25% to 50% by weight of ingredients of an ointment. DETAILED DESCRIPTION OF THE INVENTION The ointment ingredients of the composition contained in an aerosol container in accordance with the present invention includes such medically active ingredients, petroleum jellies, oils, volatile liquids, thickening agents, surfactants, and dispersed solids as may be present in the composition. Adjuvants such as known fragrances, corrosion inhibitors, preservatives, and coloring agents may also be present as ointment ingredients. Oils that may be used in the compositions include mineral oils, silicone oils, vegetable oils such as corn oil, safflower oil, soya oil, cod liver oil, and shark liver oil and synthetic oils such as isopropyl myristate, butyl stearate and dimethyl sebacate. Volatile organic liquids boiling below about 250° C. may be used as partial or complete replacements of the oils, to provide an ointment component that dries to leave a non-greasy, non-oily residue. The polydimethylcyclosiloxanes having 3 to 5 silicone atoms are particularly useful, because of their low potential to cause irritation. Thickening agents that may be used include mineral waxes such as paraffin and microcrystalline waxes, animal and vegetable waxes such as beeswax, wool wax, spermaceti and bayberry wax, synthetic waxes such as hydrogenated caster oil, glyceryl monostearate, cetyl palmitate and cetyl alcohol; polymers such as polyethylene and polyisobutylene and metallic soaps such as aluminum distearate. The thickening agent(s) for oils and oil soluble ingredients present in the ointment is/(are) present in the aerosol composition of this invention in a sufficient amount such that the composition when expelled from an aerosol device, deposits as a solid or semi-solid ointment. The aerosol composition of this invention may contain between 10% and 60% by weight of thickening agent(s) based on the weight of the oil phase, as part of the oil-phase ingredients of the ointment. Water may also be included in the ointment component in the form of a water-in-oil emulsion. Water is useful in a number of ways. It can act as a solvent or a dispersion medium for an active imgredient. It evaporates so that less residue remains on the skin. It reduces costs by replacing more expensive ingredients. When a portion of the aerosol composition is expelled, the deposit is a cold ointment-like structure that is a water-in-oil emulsion. When water is included in the composition, emulsifying agents are also added to facilitate the formation of a water-in-oil emulsion. Generally, a water-soluble and an oil-soluble emulsifier are used in combination. Oil-soluble emulsifiers include the di- and tri-ethanoxy esters of lauric, myristic, palmitic and stearic acids, and the di and tri-ethanoxy ethers of lauryl alcohol, cetyl alcohol, oleyl alcohol and lanolin alcohols. Glyceryl monostearate also serves as an oil-soluble emulsifier. Water-soluble emulsifiers include the decylethanoxy esters and ethers of the above acids and alcohols, respectively; water-soluble soaps, such as potassium palmitate; anionic surfactants, such as sodium lauryl sulfate, sodium lauroyl sarcosinate and sodium stearoyl lactate; amphoteric surfactants, such as the sodium salts of the imidazoline monocarboxyl stearyl derivative and the imidazoline dicarboxyl coconut derivative; and cationic surfactants, such a cetyltrimethylammonium bromide. When water, along with water-soluble emulifiers, are used in the compositions, it is necessary that they be used judiciously so that an aqueous foam is not formed when product is released from the container. An aqueous foam will neither produce nor sustain the required temperature when n-butane is used as the propellant. Including the water in the ointment in the form of a water-in-oil emulsion assures that an aqueous foam will not form. Under certain conditions, the ointment ingredients used in the preparation of the aerosol composition can be an oil-in-water emulsion. The necessary condition is that the combination of hydrophilic and hydrophobic emulsifiers be balanced so that the type of emulsion, whether water-in-oil or oil-in-water, will depend on the volume ratio of the oil phase and the water phase. Thus, adding water to the water-in-oil emulsion will convert it to an oil-in-water emulsion. Alternatively, adding a hydrophobic liquid to an oil-in-water emulsion will convert it to a water-in-oil emulsion. In the instant invention, ointment ingredients that produce an oil-in-water emulsion are combined with a hydrophobic or non-polar propellant, i.e., n-butane, to form a water-in-oil emulsion. This emulsion may be unstable, due to the dilution effect of the relatively large volume of propellant on the emulsifiers. When a portion of the composition is expelled from the aerosol containers, the propellant component starts to evaporate. Initially, the deposit on the skin should contain sufficient propellant that it is a solid or semi-solid water-in-oil emulsion. As the deposit is rubbed into the skin, the remainder of the propellant evaporates, causing the residue to revert back to an oil-in-water emulsion that can be rinsed off with water. Thus, the conditions necessary for the use of ointment ingredients that make an oil-in-water emulsion are: (a) the emulsifier system should be balanced so that the type of emulsion that forms depends on the volume ratio of oil and water phases, (b) sufficient liquefied propellant should be present in the deposit initially so that the deposit is a solid or semi-solid water-in-oil emulsion, and (c) the oil phase of the ointment ingredients of the composition should be non-flowable below about 35° C. When water is included in the composition, it is sometimes beneficial to include ethyl alcohol or isopropyl alcohol. Humectants, such as propylene glycol, glycerine or sorbitol may also be used. Preservatives, such as sorbic acid, methyl paraben and propyl paraben may be included. Also, corrosion inhibitors, such as sodium benzoate, may be used. Various therapeutic agents may also be included in the composition. These include local anesthetic ingredients such as benzocaine, dibucaine, lidocaine and pramoxine hydrochloride; antipruritic agents such as menthol and camphor; vasoconstrictors such as ephedrine sulfate, epinephrine and phenylephrine hydrochloride; antiseptics such as hexyl resorcinol, bithionol and triclocarban; antibiotics such as bacitracin, polymyxin, mystatin and neomycin; anti-inflammatory agents such as hydrocortisone; counter-irritants such as methyl salicylate; rubefacients such as methyl nicotinate; and antifungal agents such as micronazole and ketoconazole nitrates. Preferably, therapeutic agents are included in the aerosol composition in an therapeutically effective amount. For the preparation of the compositions of this invention, ointments are prepared in the conventional manner. Generally, the ingredients are combined and heated with stirring until all ingredients have dissolved, except for those ingredients that are not soluble or are heat sensitive. These are added after the ointment has cooled sufficiently. The ointment is stirred while cooling. It is dosed into the aerosol containers at a temperature above its flow temperature. When an aqueous phase is part of the ointment composition, ingredients that are soluble or dispersible in that phase are combined with it. Preferably, the aqueous phase is then blended with the non-aqueous phase at a temperature above the flow temperature of the non-aqueous phase to form an emulsion. The two phases, either separately or as a preformed emulsion, are dosed into the aerosol containers at a temperature above their flow temperatures. Vacuum is applied to the containers to remove air and the propellant is added either before or after clinching of the valves. Either before or after adding the actuators and cover caps, the packages are passed through a water bath that is warm enough to raise the temperature of the composition above the flow temperature of the oil phase of the ointment component. Shaking causes the ointment to blend with the propellant. The studies that resulted in this invention were conducted using compositions packaged in aerosol containers fitted with valves with one or two 0.5 mm. diameter orifices and 1 mm. inside diameter dip tubes. The actuator had a spout with a 1 mm. diameter opening. From 2.5 to 5.0 grams of composition were expelled onto a paper held 2.5 cm. from the spout. The temperature was measured starting within 30 seconds from the time the material was expelled, and the minimum temperature of the deposit was determined using an electronic thermometer with the probe inserted in the deposit with the paper folded so that as much of the deposit as possible surrounded the temperature probe. These test conditions were used in establishing the preferred temperature range and in determining how long the temperature was sustained. To study various physical effects, actuators, valves and dip tubes with different size openings were used. Tests were also conducted when the distance between the actuator and the paper substrate were varied. The following Examples 1-15 illustrate preferred embodiments of the invention: EXAMPLE 1 Aerosol Ointment Composition For Treatment Of Hemorrhoids Parts By Weight Petroleum jelly (1) 26.4 Microcrystalline wax (2) 6.6 Epinephrine 0.01 Pramoxine hydrochloride 1.0 n-Butane 66.0 (1) flow temperature = 41° C. (2) melting point = 74° C. Ointment flow temperature = 48° C. This example illustrates an aerosol composition for the relief of hemorrhoids. It was prepared by first milling the pramoxine hydrochloride with the petroleum jelly until the dispersion was complete. The dispersion was then combined with the wax and heated with stirring until the wax had dissolved in the petroleum jelly. The composition was then cooled to 55° C. and the epinephrine mixed in. The fluid solution was added to the aerosol cans, valves were clinched on, vacuum was applied to remove air in the cans and n-butane was added under pressure. The filled cans were placed in a heated water bath to check for leaks and to bring the composition to a temperature above the flow temperature of the ointment. Spout actuators with a 1 mm. opening were placed on the valves and the cans were shaken to dissolve and/or disperse the ointment in the n-butane. To use, the container was shaken and then held with the actuator close to a double layer of toilet tissue. About a 2 gram deposit was expelled onto the tissue. The ointment on the tissue was held against the hemorrhoids until it no longer felt cold. The sustained cold had the immediate effect of providing relief from burning and itching, while simultaneously the inflamed tissue appeared to shrink and recede to its normal position. These immediate beneficial effects due to the sustained cold were continued by the actions of the local anaesthetic and the vasoconstrictor present in the ointment. EXAMPLE 2 Aerosol Ointment Composition For Treatment Of Sunburn Parts By Weight Glyceryl monostearate (1) 11.6 Isopropyl myristate 17.4 Camphor 1.0 n-Butane 70.0 (1) melting points = 57.5° C. Ointment flow temperature = 44° C. Example 2 illustrates an ointment composition for treatment of sunburn. It was prepared by heating with stirring to dissolve the glyceryl monostearate and camphor in the isopropyl myristate. The solution was cooled to 50° C. and dosed into aerosol cans. Valves were crimped onto the cans, a vacuum was drawn and the propellant was added under pressure. The filled cans were placed in a heated water bath to check for leaks and to bring the composition above the flow temperature of the ointment. The cans were then shaken. The molten ointment mixes readily with the propellant in which it is dissolved and/or dispersed. Spray actuators with a 0.5 mm. diameter opening were fitted on the valves. To use, the container was shaken and held only a few cm. from the sunburned area before spraying. The sustained cold quickly relieved burning and itching sensations due to the sunburn. The ointment was then spread to more uniformly cover the sunburned area. The antipruritic agent present in the composition continues the therapeutic effect. EXAMPLE 3 Aerosol Ointment Composition For Treatment Of Arthritic Pain Parts By Weight Glyceryl monostearate (1) 17 Methyl salicylate 17 n-Butane 66 (1) melting point = 57.5° C. Ointment flow temperature = 38° C. This example illustrates an aerosol composition for the relief of arthritic pain. The glyceryl monostearate and methyl salicylate were combined and heated to dissolve the glyceryl monostearate. The remainder of the procedure was the same as example 2, except that spout actuators with a 1 mm. diameter opening were used instead of spray actuators. To use, the aerosol can was shaken and a small amount of the cold ointment was expelled and spread over the arthritic area. The sustained cold provided quick relief. The ointment was then rubbed into the area. As it was being rubbed in, the warm counter-irritant action of the methyl salicylate could be felt through the cold. EXAMPLE 4 Aerosol Ointment Composition For Treatment For Relieving Itching Parts By Weight Glyceryl monostearate (1) 10 2 Hexyldecanol 15 Hydrocortisone  1 n-Butane 64 Isobutane 10 (1) melting point = 57.5° C. Ointment flow temperature = 40° C. The hydrocortisone aerosol composition provides instant relief from itching. The glyceryl monostearate, 2-hexyldecanol and hydrocortisone were combined and heated with stirring to obtain a clear solution. The remainder of the procedure was the same as in example 2, except that spout actuators with a 1 mm. opening were used. When the aerosol ointment was applied, itching quickly stopped due to the sustained cold. The antipruritic effect continued throughout the day, presumable due to the action of the hydrocortisone. EXAMPLE 5 Aerosol Ointment Composition For The Relief Of Itching Parts By Weight Glyceryl monostearate (1) 5.0 Dimethylcyclopolysiloxane (2) 12.0 Hydrocortisone 1.0 Disodium cocoamphodipropionate 0.2 Water 15.8 n-Butane 66.0 (1) melting point = 57.5° C. (2) DC 245 Fluid (Dow Corning Corp.) Ointment flow temperature = 45° C. Example 5 illustrates a hydrocortisone ointment composition for the relief of itching, where the ointment component is a water-in-oil emulsion. It was prepared by combining the oil-soluble components, heating to dissolve the glyceryl monostearate, and then cooling with mixing until it started to thicken. The water-soluble surfactant was dissolved in the water and heated to the temperature of the oil mixture. The aqueous solution was mixed into the oil phase to form a water-in-oil emulsion, which was heated until it flowed, and then dosed into aerosol cans. The remainder of the procedure was the same as in Example 1. EXAMPLE 6 Aerosol Ointment Composition For The Relief of Muscle Aches Parts By Weight Glyceryl monostearate (1) 8.6 Dimethylcyclopolysiloxane (2) 6.5 Mineral oil 6.5 Menthol 2.0 Disodium cocoamphodipropionate 0.15 Water 9.8 n-Butane 66.45 (1) melting point = 57.5° C. (2) DC 245 Fluid (Dow Corning Corp.) Ointment flow temperature = 41° C. Example 6 illustrates an ointment composition for the relief of muscle aches, where the ointment component is a water-in-oil emulsion. The procedure is the same as in Example 5. The benefit derived from using compositions based on water-in-oil emulsions, especially when part of the oil phase is volatile, is that when applied topically the residue is not greasy or oily. EXAMPLES 7 AND 8 Aerosols Composition Containing Ointments That Are Oil In Water Emulsions Parts By Weight 7 8 Part A Glyceryl monostearate (1) 4.2 4.2 Cetyl alcohol (2) 1.0 1.0 Mineral oil 11.5 11.5 Part B Mackam 2CSF-70 (3) 1.0 — Pluronic F68 (4) — 1.0 Water 15.6 15.6 Part C n-Butane 66.7 66.7 (1) melting point = 57.5° C. (2) melting point = 45-50° C. (3) 70% disodium cocoamphodipropionate in propylene glycol (4) polyoxyethylene-polyoxypropylene flow temperature of part A = 39-40° C. Before preparing each example, the water phase (part B) was added in increments to 10 g. of the oil phase (Part A), stirring and heating as required to maintain the molten oil phase as a liquid. It was found for example 7 that 10 g. of the water phase was required to convert the water-in-oil emulsion that formed initially to an oil-in-water emulsion. For example 8, the formation of a water-in-oil emulsion followed by its conversion to an oil-in-water emulsion required 7 g. In the same manner, each example was prepared by adding part B to part A in increments with stirring, heating as required. The propellant was added through the valve. The can was then placed in a water bath at 50° C. and kept there for a sufficient period to bring the contents of the can to 45° C. Then, it was removed form the water bath and shaken. The valve stem was fitted with an actuator. Subsequently, examples 7 and 8 were evaluated. Both examples gave cold semi-solid deposits of an ointment-like consistency when small amounts were applied to the skin. There was no evidence of aqueous foam formation with either example, as would have been the case if they had been expelled as oil-in-water emulsions. They spread smoothly on the skin, and could be rinsed off with water. EXAMPLES 9 AND 10 Aerosol Ointment Compositions Containing Antifungal And Antibacterial Agents, Respectively Parts By Weight Example 9 Example 10 Antifungal Antibacterial Part A Glyceryl monostearate (1) 2.8 3.9 Cetyl alcohol (2) 0.9 1.3 Menthol 0.3 0.4 Dimethyl cyclosiloxane 3.0 4.2 Isopropyl myristate 1.7 3.4 Mineral oil 1.1 3.3 Petroleum jelly 1.3 Methyl paraben 0.07 0.07 Propyl paraben 0.03 0.03 Part B Polysorbate 20 0.33 0.5 Polysorbate 40 0.33 Neomycin 0.17 Water 20.6 16.0 Part C Micronazole nitrate 0.67 Magnesium stearate 0.2 Part D n-Butane 66.6 66.7 (1) melting point = 57.5° C.; (2) melting point = 45-50° C.; (3) DC 345 Fluid Flow temperature of Part A = 42° C. Preparation Parts A and B are separately prepared by combining ingredients and heating with stirring to dissolve. Both parts are heated to 50-55° C. and part B is slowly added to part A with stirring to form an emulsion. Without cooling, part C is mixed in and homogenized. With the emulsion at 45-50° C., the emulsion is dosed into aerosol cans. Valves are clinched on the cans and part D is added. The cans are placed in a heated water bath to bring the contents in the cans to 45° C. or higher. The cans are shaken well on a vibrator or a case shaker. The aerosol ointment preparation of Examples 9 and 10, respectively, when expelled from an aerosol can, provides a cold semi-solid or solid deposit initially between about −5° C. and +5° C. EXAMPLE 11 Aerosol Composition Useful For The Relief Of Sunburn The aerosol composition is prepared as in example 8, except that 0.3 parts by weight of water are replaced with 0.3 parts by weight of pramoxine hydrochloride. The aerosol ointment preparation of Example 11 when expelled from an aerosol can, provides a cold semi-solid or solid deposit initially between about −5° C. and +5° C. EXAMPLE 12 Aerosol Composition Useful As A Topical Antiseptic. The aerosol composition is prepared as in example 7, except that 0.3 parts by weight of mineral oil are replaced by 0.3 parts by weight of bithional. The aerosol ointment preparation of Example 12 when expelled from an aerosol can, provides a cold semi-solid or solid deposit initially between about 5° C. and +5° C. EXAMPLE 13 Aerosol Composition Useful As An Antipruritic The aerosol composition is prepared as in example 10, except that 0.17 parts by weight of neomycin and 0.17 parts by weight of water are replaced by 0.34 parts by weight of pramoxine hydrochloride. The aerosol ointment preparation of Example 13 when expelled from an aerosol can, provides a cold semi-solid or solid deposit initially between about 5° C. and +5° C. EXAMPLES 14 AND 15 Aerosol Compositions Useful For Relief of Hemorrhoids The following examples 14 and 15 illustrate the use of isobutane and a mixture of propellants that includes propane for the preparation of aerosol compositions that may be used for the relief of hemorrhoids. Propane has too high a vapor pressure to be used alone in retail aerosol products. Instead, it is commonly used in combination with isobutane, which has a lower vapor pressure. The vehicles used in these examples may also be used for other product applications, often by simply changing the active ingredient or by adding an additional active ingredient. For instance, by replacing 0.5 parts by weight of water with menthol in the preparation, Example 14 illustrates an aerosol composition preparation that, when expelled from an aerosol can, provides a solid or semi-solid ointment that is effective as an antipruritic. Example 14 may be used to prepare an aerosol composition preparation that, when expelled from an aerosol can, is effective for the relief of sunburn, by replacing 0.5 parts of water with cetyl pyridinium chloride in the preparation. Parts by Weight Example 14 Example 15 Part A Glyceryl monostearate (1) 3.6 9.2 Cetyl alcohol (2) 1.8 4.6 Isopropyl myristate 3.6 9.2 Mineral oil 9.0 23.0 Part B Polysorbate 20 0.8 — Pramoxine hydrochloride 0.5 — Water 25.7 — Part C Isobutane 55.0 — A 46 (3) — 54.0 (1) melting point = 57.5° C.; (2) melting point = 45-50° C. (3) mixture of propane and isobutane with a vapor pressure of 46 p.s.i.g. Flow temperature of part A is 43° C. Preparation Parts A and B are prepared separately by combining ingredients and heating with stirring to dissolve the ingredients in oil or water, respectively. Both parts A and B are brought to a temperature of 50-55° C. and part B is slowly added to part A with stirring to form an emulsion. With the emulsion at a temperature of 45-50° C., the emulsion is dosed into aerosol cans. Valves are clinched on the aerosol can and part C is added to the aerosol cans. The cans are placed in a heated water bath to bring the contents in the aerosol cans to a temperature of 45° C., or higher. The cans are shaken well on a vibrator or case shaker. The aerosol composition preparations of Examples 14 and 15, when expelled from an aerosol can, provide a cold solid or semi-solid deposit initially between about −5° C. and +5° C. Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

Aerosol compositions are provided that enhance the therapeutic action of ointments by producing, upon topical application thereof, a sustained cooling effect that provides fast relief form pain and itching as well as a tendency to shrink swollen, inflamed tissue. The compositions contain oils, thickening agents for the oils, and propellant. Aqueous solutions, therapeutic ingredients and various adjuvants may also be present. The specific propellant and the proportion used are selected to provide a deposit with a temperature of about −5° C. to about +5° C. In this temperature range, the deposit is cold enough for the required therapeutic effect, but not so cold as to cause pain or tissue damage. The choice and proportion of thickening agents used are selected to provide a deposit that does not flow or spread. Were the deposit to spread, it would present a large surface area from which propellant present in the deposit would evaporate rapidly. By avoiding spreading, the propellant evaporates more slowly and the cooling effect is more sustained.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0001] Not Applicable. BACKGROUND OF THE INVENTION [0002] Because of its importance to a large segment of this population, or compared to other conditions, coronary heart disease has been the subject of particular attention during the 20th century from the standpoint of understanding the root causes of various diseases and what steps can be taken to prevent the same. A century ago, physicians generally did perceive a link between obesity and heart disease. However, the general view was that the large bulk of an obese individual represented an excessive load for an overburdened heart, in much the same way as excessive exercise during a short period of time could damage the heart. [0003] Even by the middle of the 20th century, the protocol for lowering the incidence of coronary heart disease was relatively simple. Patients were told to eliminate, or at least reduce, smoking, and limit the intake of foods. As far as cardiac patients were concerned, calorie counting was the primary tool on the dietary front. [0004] Gradually, however, the picture became increasingly complex. It emerged that cholesterol was an important factor in assessing the risk of coronary heart disease. Exercise, likewise, came to be recognized as an important factor in lowering cholesterol. Fats were also recognized as a dietary component which could be problematic. Accordingly, patients were counseled to reduce fat intake. It then emerged that all fats are not equal in terms of the potential damage that they can do to the heart. Differing impacts on the heart for unsaturated, saturated, monounsaturated and polyunsaturated fats came to be known. It was also learned that cholesterol, per se, is not the best indicator of risk, and that cholesterol in the body can be divided between HDL (high density lipoprotein) cholesterol, and LDL (low density lipoprotein) cholesterol. In addition, triglycerides were found to be a part of the factors involved in an assessment of risk of cardiac disease. Thus, the assessment of risk of cardiac heart disease reached a higher degree of complexity, when it was recognized that not all forms of cholesterol increase the risk of heart disease. In particular, it was recognized that, to the contrary, HDL cholesterol (a high density material packaged by the body for elimination and less likely to adhere to interior coronary sidewalls), if present in sufficient quantities, appeared to lower the risk of myocardial infarction and coronary death. [0005] Still another complicating factor has been the availability of cholesterol-lowering medications. Many specialists in the field believe that such medications should be almost universally administered. Others question efficacy in such a diverse population, and point to cost concerns, which are no longer strangers to medical care. [0006] Given the wealth of information data, the problem then became one of properly assessing the data. The Report of the National Cholesterol Educational Program sought to outline a strategy for primary prevention of coronary heart disease in persons with high levels of low-density lipoprotein (LDL) cholesterol (greater than or equal to 160 milligrams per deciliter) or those with borderline-high LDL cholesterol (130-159 milligrams deciliter) and multiple (i.e. two or more) risk factors. [0007] The Second Report of the Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults repeated this approach and added the intensive management of LDL cholesterol in persons with established chronic heart disease, setting a new lower LDL cholesterol goal of less than or equal to 100 milligrams per deciliter for chronic heart disease patients. [0008] The Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATP III) attempted to deal with continuing difficulties being experienced by the medical community in assessing and evaluating all the new information and treatment options. [0009] Thus, unlike other conditions, in the case of a great part of the population, the causes of heart disease are better understood today and effective prevention strategies are, at least from a theoretical viewpoint, available. Nevertheless, heart disease remains one of the leading health problems in the United States. The situation is exacerbated due to the fact that the prosperity, which our country now enjoys, increases the incidence of heart disease in the general population on account of the impact of richer diets and sedentary life styles. [0010] ATP III builds upon the Second Report, and adds the facet of focusing on primary prevention in persons with multiple risk factors. In particular, for many persons with multiple risk factors, ATP III recommends aggressive LDL-lowering treatments as compared to the Second Report. In addition, numerous other refinements have been introduced, including treating persons with diabetes but without coronary heart disease as having a risk level comparable to that of persons with coronary heart disease. Likewise, the Framingham projections of ten-year absolute cardiac heart disease risk to identify patients with multiple risk factors for more intensive treatment, as well as to identify persons with multiple metabolic risk factors as candidates for intensified therapeutic lifestyle changes are implemented. [0011] In accordance with ATP III, a complete glycoprotein profile including measurements of total cholesterol, LDL-cholesterol, HDL cholesterol and triglycerides is the preferred initial test. This compares with the prior approach of screening for total cholesterol and HDL cholesterol during the initial testing of a patient. [0012] ATP III represents the latest attempt to logically approach the very complex interrelationships between relevant cardiac heart disease risk factors and balance the same in crafting an effective treatment regimen. The same is achieved using the Framingham factors. Alternative approaches implement a mathematical formula treating various risk factors or an estimation approach based on points. [0013] More particularly, in accordance with the Adult Treatment Panel III (ATP III) guidelines for clinical cholesterol management, medical professionals are provided with a specific methodology to assess risk and improve coronary heart disease outcomes in their patients. A complex nine step approach has been detailed as part of a National Cholesterol Education Program spearheaded by the United States Department of Health and Human Services. [0014] The first step is the determination of glycoprotein levels using a complete glycoprotein profile after a 9 to 12 hour patient fast. LDL-cholesterol is measured as the primary target of the therapy, with optimal levels being below 100 milligrams per deciliter. Total cholesterol levels are desirably below 200 milligrams per deciliter with HDL's desirably greater than 60 milligrams deciliter. [0015] The next step is the identification of any clinical atherosclerotic disease, which carries a high risk of coronary heart disease. [0016] The physician then determines the presence of other major risk factors (other than LDL-cholesterol). These include cigarette smoking, hypertension, and a family history of premature coronary heart disease (premature being defined as before the age of 55 in the case of a male first-degree relative and below the age of 65 in a female first-degree relative). [0017] If there are two or more risk factors present, the Framingham tables are used to assess the ten-year (short-term) coronary heart disease risk, unless coronary heart disease or coronary heart disease risk equivalent (an event) is present. [0018] In a fifth step, risk category is determined by establishing a goal for LDL-cholesterol level, determining the need for therapeutic lifestyle changes and determining whether a particular level of cholesterol-lowering drug therapy should be considered. More particularly, the establishment of LDL goals in ATP III are listed at less than 100 milligrams for deciliter for coronary heart disease risk equivalents or coronary heart disease risk greater than 20 percent. Where risk is below 20 percent and two or more risk factors are present, LDL goals are set at less than 130 milligrams deciliter. Finally, where there are one or fewer risk factors, listed LDL goals are below 160 milligrams deciliter. [0019] The next step is to initiate therapeutic lifestyle changes if LDL cholesterol is above the goal. These include reduction in the dietary intake of saturated fats, introduction of viscous fiber into the diet and treatment with plant stanols/sterols, together with weight management and increased physical activity. [0020] Step 7 involves consideration of drug therapy if LDL cholesterol exceeds the above step 5 levels. More particularly, and drug therapy should be considered together with implementation of therapeutic lifestyle changes for coronary heart disease and coronary heart disease problems. Alternatively, consideration should be given to ending drug therapy after three months of therapeutic lifestyle changes and an evaluation of progress. [0021] The next step involves the identification of metabolic syndrome and treatment of the same, if present, after three months of therapeutic lifestyle changes. Determination of metabolic syndrome involves assessing abdominal obesity, high triglyceride levels, low HDL cholesterol levels, high blood pressure and testing for glucose. Different cutoff points for these factors are involved for men and women. [0022] The last step is a treatment of elevated serum triglycerides with all ranges being below 150 milligrams deciliter and very high ranges extending above 500 milligrams deciliter. This is combined with treatment of elevated triglycerides and treatment of low HDL cholesterol. [0023] As noted above, the evaluation of the risk of coronary heart disease is done using point scores associated with the age of the patient, total cholesterol, whether the patient is a smoker or non-smoker, the level of HDL cholesterol, and systolic blood pressure. In accordance with the Framingham points scored technique, points are edited and depending upon point total risk is estimated. For example, for men, 0 points carries a less than 1 percent risk of heart disease over a ten-year period, and 10 points carries a 6 percent risk of heart disease and 17 or more points carries a risk of heart disease greater than or equal to 30 percent. Assignation of point scores and assessment of risk on the basis of total points is different for women. [0024] Alternatively, a mathematical formula developed on the basis of the Framingham Study may be used to assess risk. [0025] As can be seen from the above, the determination of risk, determination of treatment strategy, testing treatment options and determination of alternate approaches, where necessary, has become a complex task. Moreover, the mathematics associated with the assessment of long-term risk, and the mental distraction and/or overload associated therewith is impeding the quality generation of patient-specific methodologies of treating the patient's condition. In addition, the increasing pressure to provide treatment to more and more patients, and the time pressures associated therewith is increasing the likelihood of less than optimal judgments by medical practitioners. [0026] Particularly in the last few years, in addition to the difficulties posed by the complexity of the tasks required to provide quality medical care in the cardiac field, the dominating presence of managed care has exerted substantial economic pressure on the practice of medicine. Hospitals and doctors are being forced to regulate the amount of time being spent by an individual physician with his patient. The combination of time pressure, sometimes difficult patients, distractions, and other factors all contribute, together with the increased complexity of the problem, to the difficulty of a quality assessment of a patient's coronary heart disease risk, and development of an appropriate treatment strategy. SUMMARY OF THE INVENTION [0027] Perhaps more seriously for the future, is the likelihood that the situation is expected to become increasingly complex in the future. For example, new research is beginning to indicate that certain LDL cholesterols are associated with extremely high levels of risk. Thus, in the future, additional tests will indicate the levels of these very high risk LDL cholesterols, and appropriate more complex weighting, or other risk evaluation methodology, will have to be applied, before treatment strategies, strategy testing and strategy amendments will have to be determined. Thus, the future appears to hold increasingly higher likelihood of coronary risk assessment complexity, economic and time pressures, and consequential higher likelihood of less than optimal treatment option determination and evaluation. [0028] In accordance with the invention, risk evaluation, treatment options, and assessment of tested treatment options is implemented by the use of specialized computing device. In addition, reducing likelihood that the inventive method will not be implemented on account of the difficulty of introducing a computer into a typical physician-patient clinical setting is mediated by implementation on a handheld device which can unobtrusively be used by the physician in the presence of the patient and with ease, and without being so obvious to disturb the patient into believing that judgments are being made by a computer. [0029] At the same time, in accordance with a preferred embodiment, treatment options are provided in suggestion form in order to avoid automatic implementation of suggestions without the necessary input of physician judgment. [0030] It is an object of the present invention to achieve the above advantages without the inherent unreliability of personal computing systems. The same is achieved by a dedicated computing device. Costs are controlled by a minimally sized display and input keypad. The result is a computing device which also has very low power consumption, and thus extended battery-powered life, thus providing additional degrees of convenience and reliability. [0031] In accordance with a particularly preferred embodiment of the invention, information on various patients is stored in random access memory contained in the inventive device and downloaded to a conventional personal computer by way of an infrared port, Blue Tooth communications protocol, a USB connection or other hard wired or wireless communications technique. [0032] In accordance with the invention, a method of determining a regimen for the treatment of individuals with elevated risks of developing coronary heart disease comprises receiving and electronically storing risk factor information respecting the sex, age, blood chemistry and lifestyle of an individual, electronically executing an algorithm on said risk factor information, and displaying at least one result of said execution of said algorithm on said risk information. [0033] An inventive method of reducing the risk of coronary heart disease in the general population comprises presenting on a handheld computing device a series of questions relating to risk factors for coronary heart disease respecting the sex, age, blood chemistry and lifestyle of an individual. The handheld computing device is used to receive and electronically store risk factor information input by a physician. An algorithm is electronically executed on a dedicated electronic device by using the input risk factor information. At least one result of said execution of the algorithm evaluating said risk information is output by the handheld device in the form of a message identifying a potential therapy for consideration. [0034] The inventive method of reducing the risk of coronary heart disease in the general population, also contemplates the possible funding of distribution of dedicated electronic devices by selling advertising physically associated with the dedicated electronic devices. Such advertising may be associated with possible treatments for reducing the risk of coronary heart disease. BRIEF DESCRIPTION OF THE DRAWINGS [0035] The inventive method and apparatus may be understood from the description below, taken together with the drawings, in which: [0036] [0036]FIG. 1 illustrates an input device constructed in accordance with the present invention and which is adapted to implement the method of the present invention; [0037] [0037]FIG. 2 is a view of the reverse side of the inventive device illustrated in FIG. 1; [0038] [0038]FIG. 3 is an alternative embodiment of the inventive device; [0039] FIGS. 4 - 18 illustrates the use of the inventive device to practice the inventive method during the data input phase; [0040] [0040]FIG. 19 is a flow diagram illustrating the method of the present invention; [0041] FIGS. 20 - 22 illustrate the inventive device during part of the data output phase of the inventive method; and [0042] FIGS. 23 - 25 illustrate the alternative inventive device illustrated in FIG. 3 during data entry steps of the inventive method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0043] In accordance with the present invention, an inventive input device 10 is used to input data during implementation of the inventive method. Input device 10 includes a display 12 for indicating what information should be input into device 10 , and for outputting results. The key pad is formed by a plurality of keys, including numerical keys 14 , special-purpose input keys 16 and 18 , and a “results” key 20 . [0044] In addition to the electronic functions implemented by keys 14 - 18 , in accordance with the preferred embodiment of the invention, funding for the device is achieved through the use of advertising, in this case the inclusion of the trademark 22 of a drug “BanHDL”. In the instant case, the manufacturer of the drug BanHDL pays money or other consideration to the person or organization distributing the inventive input device 10 . Alternatively, the inventive input device 10 may be distributed by the drug manufacturer. In addition to the above, and in order to build value into the inventive input device 10 , information respecting the drug, or other products maybe provided in the form of alphanumeric printing 24 on the reverse side of data input device 10 , as illustrated in FIG. 2. Such alphanumeric printing 24 may be imprinted in any fashion, such as a silk screen technique, by being adhered after being printed on a self-adhesive transparent or opaque label using a computer printer, or the like, or other process. [0045] In accordance with the invention, the inventive data input device is also provided with a “clear/clear entry” key 30 which when depressed once clears an entry, and when pressed twice clears all entries and returns the user to the initial screen. And “enter” key 32 is depressed in order to enter information input into the system using keys 14 . [0046] In accordance with the present invention, alternative arrangements of keys and screen and the like, may be implemented, as illustrated, for example, in FIG. 3, by data input device 110 , which will be described in greater detail below. [0047] Generally, however, in this embodiment, the output of screen 112 is set up to cooperate with keys 116 and 118 which may or may not be marked with alphanumeric data. Special purpose keys 16 and 18 have been replaced by keys 116 and 118 . More particularly, in accordance with the invention it is contemplated that region 126 will carry information respecting the function of special-purpose key 116 , and region 128 will carry information respecting the function of special-purpose key 118 . [0048] Referring to FIGS. 4 - 18 , the inventive method commences with the actuation of key 20 . In accordance with the preferred embodiment, keys 14 - 20 are pushbutton keys and may be activated by simply being pressed. When key 20 is pressed, the first data input screen is presented, as illustrated in FIG. 4. [0049] Alternatively, when key 20 is pressed, optionally, a welcome screen may be presented saying, for example: “Welcome to risk calculation” or, perhaps more elaborately: “Welcome. We will guide you step-by-step to calculate risk of cardiac heart disease.” After a period of time, the welcome screen will disappear and the first data input screen will be presented. [0050] In accordance with the invention, the inventive data input device 10 facilitates the assessment by a physician of a patient's coronary heart disease risk factors, and simply calculates 10-year risk coronary heart disease based on the individual patient's coronary heart disease risk factors, as well as to establish a risk category and suggest an LDL-cholesterol goal for the patient, as well as help the physician determine the best treatment options to reach that goal and thus reduce the risk of coronary heart disease events. [0051] As illustrated by the data input screens illustrated in FIGS. 4 - 18 , the inventive process 210 (FIG. 19) begins by collecting data from the patient, initially by way of physical examination, blood tests and the like. These include such things as waste measurements, weight, LDL-cholesterol, HDL cholesterol, total cholesterol, triglycerides, whether the patient smokes, and so forth, as recommended by the ATP III guidelines and the general practice of the physician, which items of data are utilized by the method and apparatus of the present invention as detailed below. [0052] The inventive calculator, once activated by depression of key 20 , at step 212 , and the optional presentation of a welcome screen at step 214 , begins by asking the physician a series of questions about the patient's laboratory results, lifestyle risk factors, medical history, and so forth, as per the above collection of information, as will be detailed below. The requested information is input into the data input device 10 using the special purpose and numeral keys as appropriate. If the data has been successfully entered, the physician then presses the “Enter” key 32 to enter the information and cause data entry device 10 to display the next screen. The “Clear” key may be used to clear the current screen, if necessary, by being pressed once. Pressing the “Clear” key more than once causes the system to be completely cleared and to present the welcome screen to the physician for the input of a complete set of data as detailed below. [0053] Referring to the data input screens illustrated in FIGS. 4 - 18 , at the first data input screen display 34 (FIG. 4), presented at step 216 , the system asks the physician to input the sex of the patient. The system may simply display: “1. Sex?”. A more elaborate message may be used on the screen (and any of the other screens that are described below), such as: “Enter patient's sex and press ‘Enter’”. In response, the physician depresses key 16 , if the patient is male, or key 18 , if patient is female. Enter key 32 is then pressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0054] In accordance with the present invention, each of the screens is assigned a screen number (in the case of the screen of FIG. 4, the screen number “1”). In the case of FIGS. 4 - 18 , the screen number appears in the form of a question number (in the case of FIG. 4, the question number is “1”), which appears on the screen together with the request for information (i.e. the “question”). In similar fashion, when data is output by the system, such data is also associated with a screen number which is displayed on the display. The function of the screen number is to identify the screen by number allowing correlation of printed instructional information to each particular screen, as appears more fully below. [0055] Referring to FIG. 5, at step 218 , the system presents the next data input screen display 36 , reading: “2. Age in Years?” (question number 2 at screen number 2). In response, the physician enters in the age of the patient using numerical keys 14 . Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0056] Referring to FIG. 6, at step 220 , the system presents the next data input screen display 38 , reading: “3. Total Chol in mg/dl?” (question number 3 at screen number 3). In response, the physician enters the total cholesterol level of the patient in mg per dl using keys 14 . Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0057] Referring to FIG. 7, at step 222 , the system presents the next data input screen display 40 , reading: “4. LDL Chol in mg/dl” (question number 4 at screen number 4). In response, the physician enters the cholesterol of the patient in mg per dl using keys 14 . Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , for later use by the system together with the other data input by the physician, as will be described in detailed below. After this, the next screen is presented at the next step. [0058] Referring to FIG. 8, at step 224 , the system presents the next data input screen display 42 , reading: “5. HDL chol in mg per dl?” (question number 5 at screen number 5). In response, the physician enters the HDL cholesterol level for the patient using keys 14 . Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0059] Referring to FIG. 9, at step 226 , the system presents the next data input screen display 44 , reading: “6. Triglyc in Mg/Dl?” (question number 6 at screen number 6). In response, the physician enters the triglycerides level of the patient using keys 14 . Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0060] Referring to FIG. 10, at step 228 , the system presents the next data input screen display 46 reading: “7. CHD/PAD/AAA/ctd dz?” (question number 7 at screen number 7). The object of this query is to determine whether the patient has been diagnosed with any one of the following conditions: coronary heart disease (CHD), peripheral arterial disease (PAD), abdominal aortic aneurysm (AAA) or carotid artery disease (symptomatic, or asymptomatic with greater than 50 percent stenosis) (ctd dz). In response, the physician enters a “Yes” or “No” for the patient using keys 16 and 18 , depending upon whether or not any one of these conditions has been diagnosed in the patient. Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0061] Referring to FIG. 11, at step 230 , the system presents the next data input screen display 48 , reading: “8. Diabetes?” (question number 8 at screen number 8). In response, the physician enters whether the patient has diabetes using either the “Yes” and “No” keys 16 and 18 . Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. In accordance with an alternative embodiment of the invention, whenever “Yes” or “No” keys 16 and 18 are depressed, the next screen may be presented without the necessity of pressing enter key 32 . [0062] Referring to FIG. 12, at step 232 , the system presents the next data input screen display 50 , reading: “9. Glucose?” (question number 9 at screen number 9). In response, the physician enters the fasting glucose level of the patient using keys 14 . Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0063] Referring to FIG. 13, at step 234 , the system presents the next data input screen display 52 , reading: “10. Fam Hist F<55 or M<45” (question number 10 at screen number 10). In response, the physician enters a “Yes” by using keys 16 if a male first-degree relative (father or brother) of the patient had a heart attack before the age of 45, or a female first-degree relative (mother or sister) of the patient had a heart attack before the age of 55 using key 16 , as per the ATP III guidelines. Otherwise, a “No” is entered into the system using key 18 . Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0064] In accordance with a preferred embodiment of the invention, whenever the “yes” or “no” buttons are depressed or a number entered, the same appears on screen 12 , as illustrated in FIGS. 14 and 15, respectively. [0065] Referring to FIG. 14, at step 236 , the system presents the next data input screen display 54 , reading: “11. Smoker? Cigs Past Mo?” (question number 11 at screen number 11). In response, the physician enters a “Yes” or “No” for the patient, depending upon whether the patient has smoked cigarettes within the last month. This is done using keys 16 and 18 . Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0066] Referring to FIG. 15, at step 238 , the system presents the next data input screen display 56 , reading: “12. Systolic BP in mm Hg?” (question number 12 at screen number 12). In response, the physician enters the systolic blood pressure of the patient in millimeters of Hg using keys 14 . Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0067] Referring to FIG. 16, at step 240 , the system presents the next data input screen display 58 , reading: “13. Diastolic BP in mm Hg?” (question number 13 at screen number 13). In response, the physician enters the diastolic blood pressure of the patient in millimeters of Hg using keys 14 . Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0068] Referring to FIG. 17, at step 242 , the system presents the next data input screen display 60 , reading: “14. Blood Pressure Medication?” (question number 14 at screen number 14). In response, the physician enters a “Yes” or “No” using keys 16 or 18 , respectively, depending upon whether the patient is on medication to reduce high blood pressure or not. Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0069] Referring to FIG. 18, at step 244 , the system presents the next data input screen display 62 , reading: “15. Waist Circum in Inches” (question number 15 at screen number 15). In response, the physician enters the circumference of the waist of the patient in inches using keys 14 . Enter key 32 is then depressed to enter the data into the random access memory of data input device 10 , and the next screen is presented at the next step. [0070] When the enter key is pressed to enter the waist of the patient, and, optionally (depending upon design specifications) the results key 20 is pressed, the system proceeds to step 246 . At step 246 , the system, in accordance with the inventive method, retrieves information input in response to question 7 at screen number 7. If the answer which the physician entered into the system for question number 7 was positive, that is that the patient had been diagnosed with coronary heart disease (CHD), peripheral arterial disease (PAD), abdominal aortic aneurysm (AAA) or carotid artery disease (symptomatic, or asymptomatic with >50 percent stenosis) (ctd dz), the system proceeds to step 248 . At step 248 risk is assessed in accordance with the method which will be detailed below. [0071] If, after retrieving the answer to question 7 from random access memory, it is determined that such disease is not exist, the system proceeds to step 250 , where the system consults random access memory to determine whether the patient has been diagnosed with diabetes. In the answer entered by the physician is that the patient has been diagnosed with diabetes, the system proceeds to step 248 for a determination of risk. If the answer is “No”, the system proceeds to step 252 to identify and assess major risk factors. [0072] At step 252 , the system determines the number of major risk factors by adding points. More particularly, if the responses to questions one and two show that the patient is a male over 45 or a female over 55, one point is assigned and added to the total of other applicable points. If the data entered into the system by the physician in response to question 5 indicates that the HDL cholesterol of the patient is below 40, another point is added to the total. However, if the HDL cholesterol is greater than or equal to 60, a point is subtracted from the total. In similar fashion, if the answer to question 10 shows a family history of early heart disease, another point is headed to the total. If the patient is a smoker, as indicated by the answer entered into the system in response to question 11, another point is added to the total. Finally, if the answer to question 12 indicates that systolic blood pressure is above 140, or that diastolic blood pressure is about 90, or that the patient is on blood pressure medication to lower blood pressure, another point is added to the total. Thus, if the patient is male and above 55, has an HDL cholesterol level below 40 milligrams per dl, has a family history of heart disease, is a smoker and has a systolic blood pressure above 140, the total is five major risk factors and the same is disclosed, at step 254 , on the display screen 12 of input device 10 , which displays “16. Five major risk factors” (screen number 16). [0073] When results key 20 is pressed again, if the number of risk factors displayed on screen number 16 is less than two, the system proceeds to step 248 . If the number risk factors displayed on screen number 16 is greater than two, the system proceeds to step 258 . [0074] At step 258 the ten-year risk of heart disease events (myocardial infarction and CHD death) is calculated using one of two equations, depending upon the sex of the patient. In particular, if the patient is a male, the probability of myocardial infarction and CHD death within the ten year period after which the data is collected is calculated using the equation: exp ( X− 172.3002) [0075] probability=1−0.9402, [0076] where: [0077] X=52.009610*1n(AGE)+20.014077*1n(TOTALCHOLESTEROL)−0.905964*1n(HDL CHOLESTEROL)+1.305784*1n(SYSTOLIC BP)+0.241549 (BP MEDS?)+12.096316 (SMOKING?)−4.605038*1n(AGE)*1n(TOTAL CHOLESTEROL)−2.843670*1n(AGE)*(SMOKING?) −2.933230*(1n(AGE) 2 ) [0078] The variable BPMEDS? is given the value 1 if the patient is on blood pressure lowering medicine, otherwise it is zero. The variable SMOKING? is given the value 1 if the patient smokes, otherwise it is 0. [0079] It is noted that if the age of the male patient is greater than 70, then the term 2.843670*1n(AGE)*(SMOKING?) becomes 2.843670*1n(70)*(SMOKING?). [0080] If the patient is female, then the probability of a coronary heart disease incident within the next ten years is calculated using the formula: exp( X− 146.5933) [0081] Probability=1−0.98767, [0082] X=31.764001*1n(AGE)+22.465206*1n(TOTAL CHOLESTEROL)−1.187731*1n(HDL CHOLESTEROL)+2.552905*1n(SYSTOLIC BP)+0.420251*1n(BP MEDS?)+ 13 . 075430 (SMOKING?) −5.060998*1n(AGE)*1n(TOTAL CHOLESTEROL)−2.996945*1n(AGE)*(SMOKING?) [0083] If the age of the female patient is greater than 78, then the term 2.996945*1n(AGE)*(SMOKING?) becomes 2.996945*1n(78)*(SMOKING?). [0084] The symbol “*” is used herein to denote multiplication. [0085] After the ten-year probability of heart disease events (myocardial infarction and CHD death) is calculated, the same is multiplied by 100 to show the percentage of risk and shown, at step 260 , on display screen 12 , as screen number 17, for example: “17.10 Year Risk: 21%”, as illustrated in FIG. 20. The system then proceeds to step 248 for the determination of risk category. [0086] In accordance with the invention, one of three risk categories, as defined by ATP III, are displayed by the system after results key 20 is depressed. More particularly, risk categories are defined as category 1 denoting the highest risk, category 2 denoting serious risk, and category 3 denoting relatively low risk. [0087] Risk is determined in accordance with ATP III guidelines based on a four rule algorithm: [0088] The first rule is that if the answer to question 7 (chronic heart disease or risk equivalent) is “Yes” or the answer to question 8 (diabetes) is “Yes” then the risk category is 1. [0089] The second rule is that if the answer to question 7 (chronic heart disease or risk equivalent) is “No” and the answer to question 8 (diabetes) is “No” and the sum from Screen 16 (the number of major risk factors) is less than 2 then the risk category is 3. [0090] The third rule is that if the answer to question 7 (chronic heart disease or risk equivalent) is “No” and the answer to question 8 (diabetes) is “No” and the sum from Screen 16 (the number of major risk factors) is greater than or equal to 2 and the calculation from Screen 17 (10-year risk) is greater than 20 percent, then the risk category is 1. [0091] The fourth rule is that if the answer to question 7 (chronic heart disease or risk equivalent) is “No” and the answer to question 8 (diabetes) is “No” and the sum from Screen 16 (the number of major risk factors) is greater than or equal to 2 and the calculation from Screen 17 (10-year risk) is greater than or equal to 20%, then the risk category is 2. [0092] After risk category has been determined at step 248 and displayed at screen 18 , for example in the case of a category 3 risk as “18. Risk Category 3”, the same is displayed on input device 10 at step 248 . After results key 20 has been pressed again, the system then proceeds to calculate the LDL-cholesterol goal at step 262 and display the LDL-cholesterol goal in ml/deciliter at step 264 . The LDL-cholesterol goal is determined in accordance with ATP III guidelines based on a three rule algorithm: [0093] The first rule is that if the risk category is 1, then the LDL-cholesterol goal is less than 100 mg per deciliter. [0094] The second rule is that if the risk category is 2, then the LDL-cholesterol goal is less than 130 mg per deciliter. [0095] The third rule is that if the risk category is 3, the LDL-cholesterol goal is less than 160 mg per deciliter. [0096] By way of example, if the patient has a risk category of 2, then display screen 12 presents screen number 19 as: “19. LDL goal <100 mg/dL”. [0097] When device 10 is showing screen number 19, the LDL-cholesterol goal, pressing of the results key 20 causes the system, i.e. the electronics contained within device 10 , to calculate the percentage of LDL-cholesterol reduction required to bring the patient from the current level of LDL-cholesterol to the goal. After the calculation is completed, screen number 20 is presented on display screen 12 at step 266 . For example, if the patient must reduce LDL-cholesterol by 25 percent, screen number 20 reads: “20. 25% LDL reduction”. Depression of results key 20 during display of screen number 20 causes the system to execute a nine rule algorithm (in accordance with ATP III guidelines) which causes the system to determine ATP III recommended therapeutic options and present the same, at step 270 , as screen number 21 on display screen 12 : [0098] The first rule is that if the risk category is 1 and the patient's LDL is less than or equal to 100 mg/dL, then screen number 21 reads “21. TLC, cons LDL Rx now.” Note use of the term “cons” (meaning “consider”)(in this case consider LDL lowering medication), as it is the objective of the invention to spark physician thought, and not provide a substitute therefore. Such a display is shown in FIG. 21. [0099] The second rule is that if the risk category is 1 and the patient's LDL is greater than 100 mg/dL, then screen number 21 reads “21. TLC, LDL Rx opt”. “Opt” means optional; in the instant case, LDL lowering medication is optional. [0100] The third rule is that if the risk category is 2 and the patient's LDL is greater than or equal to 160 mg/dL and the patient's 10-year risk<10%, then screen number 21 reads “21. TLC, cons LDL Rx 3 mo>160”. [0101] The fourth rule is that if the risk category is 2 and the patient's LDL is greater than or equal to 130 mg/dL, and the patient's 10-year risk of a cardiac event, as defined above, 10-20%, then screen number 21 reads “21. TLC, cons LDL Rx 3 mo>129”, directing the physician to direct therapeutic life style changes and cholesterol lowering drugs in three months if the LDL does not drop below 130. [0102] The fifth rule is that if the risk category is 2 and the patient's LDL is in the range 130-159 mg/dL and the patient's 10-year risk is less than 10% , then screen number 21 reads “21. TLC”. [0103] The sixth rule is that if the risk category is 2 and the patient's LDL is greater than 130 mg/dL, then screen number 21 reads “21. LDL @ goal, followup”. [0104] The seventh rule is that if the risk category is 3 and the patient's LDL is greater than or equal to 190 mg/dL, then screen number 21 reads “21. TLC cons Rx 3 mo>190 opt>159”, indicating more likely need of LDL medication if the LDL is 160 or higher and strong likelihood of the need from LDL cholesterol lowering drugs if the LDL is above 190. The eighth rule is that if the risk category is 3 and the patient's LDL is in the range 160-189 mg/dL, then screen number 21 reads “21. TLC, LDL Rx opt 3 mo>159”. [0105] The ninth rule is that if the risk category is 3 and the patient's LDL is less than 160 mg/dL, then screen number 21 reads “21. LDL @ goal, followup”. [0106] When the screen number 21 is being displayed, results key 20 may be depressed again, which causes the system to determine whether or not the patient is suffering from metabolic syndrome and display results in the form of screen number 21 at step 272 with a display screen which reads “22. Metabolic syndrome: Y” (as illustrated in FIG. 22) or “22. Metabolic syndrome: N”, respectively. [0107] The presence of metabolic syndrome is determined if three or more of the following conditions apply to the patient on the basis of the data entered by the physician into device 10 and stored in the random access memory of device 10 : [0108] Condition 1: The answer to question 1 (sex) is male and the answer to question 5 (HDL) is greater than 40 or the answer to question 1 (sex) is female and the answer to question 5 (HDL) is greater than 50. [0109] Condition 2: The answer to question 1 (sex) is male and the answer to question 15 (waist circumference) is greater than 40 inches or the answer to question 1 (sex) is female and the answer to question 15 (waist circumference) is greater than 35 inches. [0110] Condition 3: The answer to question 6 (triglycerides) is greater than or equal to 150. [0111] Condition 4: The answer to question 19 (fasting glucose) is greater than or equal to 110. [0112] Condition 5: The answer to question 12 (systolic b.p.) is greater than or equal to 130 or the answer to question 13 (diastolic b.p.) is greater than or equal to 85. [0113] If more than three of the above conditions are present, in accordance with ATP III guidelines, then the display on display screen 12 is: “22. Metabolic syndrome: Y”. If, on the other hand, less than three of the above conditions are present, then the display on display screen 12 reads: “22. Metabolic syndrome: N”. [0114] When screen number 22 is being displayed on display screen 12 , results key 20 may be depressed again, which causes the system to determine whether the level of triglycerides for the patient is high, borderline high or normal. This is done with three rules: [0115] The first rule is that if the answer to question 6 (triglycerides) is greater than or equal to 200 mg/dL, then screen number 23 reads: “Triglyc: High”. [0116] The second rule is that if the answer to question 6 (triglycerides) is in the range 150-199 mg/ dL, then screen number 23 reads: “Triglyc: Borderline High”. [0117] The third rule is that if the answer to question 6 (triglycerides) is greater than 150 mg/dL, then screen number 23 reads: “Triglyc: Normal”. [0118] When screen number 23 is being displayed on display screen 12 , results key 20 may be depressed again, which causes the system to display: “End”. This indicates to the physician that the physician has completed the cycle of giving and receiving information. In the course of using the inventive device 10 , it is contemplated in accordance with the invention that the physician will have on hand the patient's chart in order that the relevant information may be entered into device 10 during the data entry portion of the inventive process. Likewise, during the portion of the inventive process where the results key is being depressed and the physician is being provided with information, it is contemplated in accordance with the present invention that the physician will be entering onto the patient's chart his treatment decisions. Likewise, it is contemplated that the patient's chart may be an electronic document and the entry of the information into the chart will automatically generate a memorandum to the chart to the patient with and containing the recommended course of treatment. [0119] In accordance with the invention, it is contemplated that the inventive input and output device 10 will be accompanied by an instructional card intended to guide the physician in the use of the inventive device 10 . A suitable text for use on an instructional card, and which may further elaborate on the above, may read as follows: [0120] With the touch of a few buttons, the ATP III calculator helps you assess an individual patient's coronary heart disease (CHD) risk factors, calculate the 10-year risk for CHD events (myocardial infarction and CHD death) in patients with two or more CHD risk factors, establish a risk category and LDL cholesterol goal for the patient, and determine the best treatment options to reach that goal and reduce the risk for CHD events. [0121] The calculator summarizes and makes accessible the risk calculations and treatment recommendations contained in the Adult Treatment Panel III (ATP III) guidelines for clinical cholesterol management, which were developed by the National Heart, Lung, and Blood Institute's National Cholesterol Education Program. The calculation of CHD risk uses risk equations derived by the Framingham Heart Study. [0122] Step 1: Enter Patient Information [0123] The calculator begins by asking you a series of 15 questions about your patient's laboratory results, lifestyle risk factors, and medical history. Input the requested information using the “A,” “B,” and numeral keys as appropriate, and press the “Enter” key to enter the information and move to the next screen. Use the “Clear” key to clear the current screen if necessary. [0124] Questions 3 , 4 , 5 , and 6 : Enter your patient's total cholesterol, LDL, HDL, and triglyceride levels, respectively. [0125] Question 7: Enter “A” if your patient has been diagnosed with any of the following conditions: coronary heart disease (CHD), peripheral arterial disease (PAD), abdominal aortic aneurysm. (AAA), or carotid artery disease (symptomatic, or asymptomatic with >50% stenosis) (ctz dz). [0126] Question 8: Enter “A” if your patient has been diagnosed with diabetes. [0127] Question 9: Enter your patient's fasting glucose level. [0128] 1. Question 10: Enter “A” if your patient's father or brother developed CHD before age 55, or the patient's mother or sister before age 65. [0129] Question 11: Enter “A” if your patient has smoked any cigarettes within the last month. [0130] Question 14: Enter “A” if your patient is currently taking medication for high blood pressure. [0131] Question 15: Enter your patient's waist circumference, in inches. [0132] Step 2: Find Results [0133] Press the “Results” key. You will be led through a sequence of screens depending on the answers you provided to the questions above. (Throughout this sequence, you can also use the “Review” key to return to the previous results screen.) [0134] If your patient has established CHD or conditions that confer a risk of CHD events equal to that of established CHD (vascular disease, diabetes)—that is, if you answered “Yes” to Question 7 or 8—the calculator immediately takes you to Screen 18 and assigns the patient to Risk Category 1, indicating high risk for CHD (see below). [0135] If you answered “No” to both Questions 7 and 8, the calculator determines how many major risk factors for CHD (other than LDL cholesterol level) your patient has [Screen 16]. [0136] If you are in Screen 16, press the “Results” key again. [0137] If your patient has fewer than two risk factors, the calculator takes you directly to Screen 18 and assigns the patient to Risk Category 3, indicating low risk for CHD (see below). [0138] If your patient has 2 or more risk factors, the calculator determines your patient's 10-year CHD risk [Screen 17]. (NOTE: The calculation of 10-year risk for CHD is intended to be performed before initiating cholesterol-lowering therapy. The calculator is not intended for assessing 10-year CHD risk in patients who are already on treatment or for tracking changes in CHD risk over time.) [0139] If you are in Screen 17, press the “Results” key again to place your patient in one of three CHD risk categories (1=High; 2=Moderate, 3=Low) [Screen 18]. [0140] Once assigned to a Risk Category [Screen 18], all patients are taken through the same series of remaining screens: [0141] Press the “Results” key again. Based on the patient's risk category, the calculator assigns an LDL goal for the patient [Screen 19]. [0142] Press the “Results” key to determine the percent reduction necessary to achieve the patient's LDL goal [Screen 20]. [0143] Press the “Results” key to determine the recommended treatment to achieve the patient's LDL goal [Screen 21]. The recommended treatment depends on the patient's risk category and current LDL level. [0144] For all patients with elevated LDL cholesterol, the recommended treatment includes TLC, or therapeutic lifestyle changes. These consist of: [0145] TLC diet [0146] Saturated fat<7% of calories [0147] Cholesterol<200 mg/day [0148] Consider increased viscous (soluble) fiber (10-25 g/day) and plant [0149] stanols/sterols (2 g/day) as therapeutic options to enhance LDL lowering [0150] Weight management [0151] Increased physical activity [0152] For patients with LDL levels above certain cutpoints for their Risk Category, the treatment recommendations also encourage you to consider LDL-lowering drug treatment (“LDL Rx” on the screen). A summary of drug classes, available doses, and other information about LDL-lowering drug treatment is found in the ATP III Guidelines At-A-Glance Quick Desk Reference. The decision to use drug treatment is a matter for the physician's clinical judgement and discussion with the patient. The best choice of drug depends on the individual patient's medical history and percent LDL reduction necessary. [0153] The recommendations concerning LDL-lowering drug treatment that appear on the calculator screen are as follows: [0154] cons LDL Rx now—Consider LDL-lowering drug treatment now. [0155] cons LDL Rx 3 mo>129—Consider LDL-lowering drug treatment if the patient's LDL is greater than 129 mg/dL after 3 months of TLC. [0156] cons LDL Rx 3 mo>160—Consider LDL-lowering drug treatment if the patient's LDL is greater than 160 mg/dL after 3 months of TLC. [0157] cons Rx 3 mo>190 opt>159—Consider LDL-lowering drug treatment if the patient's LDL is greater than 190 mg/dL after 3 months of TLC. LDL-lowering drug treatment is optional if the patient's LDL is greater than 159 mg/dL after 3 months of TLC. [0158] LDL Rx opt—LDL-lowering drug treatment is optional. [0159] LDL Rx opt 3 mo>159—LDL-lowering drug treatment is optional if the patient's LDL is greater than 159 mg/dL after 3 months of TLC. [0160] LDL @ goal, followup—The patient's LDL is at goal for his or her Risk Category. Nevertheless, you should recommend that the patient undertake increased physical activity and other lifestyle changes as appropriate. Control of other risk factors and other follow-up as appropriate are also recommended. [0161] Press the “Results” key to determine whether your patient has the characteristics of Metabolic Syndrome [Screen 22]. Treatment for this condition focuses first on weight control and increased physical activity. Further details are provided in the ATP III Guidelines At-A-Glance Quick Desk Reference, Step 8. [0162] Press the “Results” key to determine whether your patient has high triglycerides [Screen 23]. For patients with high triglycerides>/=200 mg/dL, after the LDL goal is met therapy to reduce non-HDL cholesterol should be considered. Further treatment details are provided in the ATP III Guidelines At-A-Glance Quick Desk Reference, Step 9. [0163] As noted above, the input device illustrated FIG. 3 may be used to practice the inventive method. In this case, special purpose keys 116 and 118 would be used to serve multiple functions and those functions would be labeled in areas 126 and 128 of screen display 112 . For example, as illustrated FIG. 23, question number 1, “1. Sex?”, may be answered using special purpose keys 116 and 118 to indicate that the patient is male or female, respectively. As illustrated FIG. 23, areas 126 and 128 , respectively, include the designations “Male” and “Female”, and these designations serve as labels for special purpose keys 116 and 118 , respectively. Alternatively, the letters “M” and “F” may be used. [0164] In similar fashion, as illustrated in FIG. 24, special purpose keys 116 and 118 may be labeled to perform as “Yes” and “No” keys. Here question number 7 appears on display 112 and the question may simply be answered by the physician with a yes or no has indicated in areas 126 or 128 . It is noted that a pair of downward pointing arrows are used in regions 126 and 128 to indicate the position of the applicable special purpose keys 116 and 118 . [0165] In the case of questions requiring a numerical entry, such as question number 9, the special purpose keys 116 and 118 perform no function and the numerical data may simply be entered using the numerical keys 114 . This is illustrated FIG. 25. [0166] While an illustrative embodiment of the invention has been described, it is understood that various modifications will be apparent to those of ordinary skill in the art. Such modifications are within the spirit and scope of the invention which is limited and defined only by the appended claims.

A method for risk evaluation, determining treatment options, and the assessment of tested treatment options is implemented by the use of specialized computing device. Reducing likelihood that the inventive method will not be implemented on account of the difficulty of introducing a computer into a typical physician-patient clinical setting is mediated by implementation on a handheld device which can unobtrusively be used by the physician in the presence of the patient and with ease, and without being so obvious to disturb the patient into believing that judgments are being made by a computer. Treatment options are provided in suggestion form in order to avoid automatic implementation of suggestions without the necessary input of physician judgment. The above advantages are achieved without the inherent unreliability of personal computing systems by use of a dedicated computing device. Costs are controlled by a minimally sized display and input keypad.

BACKGROUND [0001] One of the inventions disclosed herein relates to the field of apparatus and methods for conducting discussion groups, and more specifically, to apparatus and methods for conducting motion-picture discussion clubs. [0002] Many people enjoy getting together with others for social aspects. In some cases, groups are formed for people having similar interests. For example, book clubs have been formed for people who enjoy reading so that they can get together and discuss a book that each member of the group has read. [0003] Many people enjoy seeing motion-pictures, such as movies, tv shows, streaming video, shorts, etc. Some of these people enjoy recommending these motion-pictures to others and discussing portions of the motion-picture with others who have seen the same motion-picture. [0004] Some people, such as immigrants for whom the predominant language is there second language, find it difficult to read or do not enjoy reading. Other people cannot read or do not have the time that it takes to read the books that are assigned by a book discussion group. Others may just not want to make the significant time commitment to read each assigned book if they do not find some of the assigned books to be very interesting. [0005] Additionally, book discussion groups can suffer from the difficulty in each member obtaining copies of the assigned book if the book is expensive, not available at the library, or out of stock at the local bookstore. Indeed, particularly popular books may be sold out at several local bookstores and members may not be able to obtain a book in sufficient time by placing the book on order. [0006] Therefore, a need exists for apparatus and methods to allow the easy formation and operation of a discussion group. SUMMARY [0007] The disclosed apparatus and methods avoid some of the disadvantages of prior apparatus and methods while affording additional advantages. BRIEF DESCRIPTION OF THE DRAWINGS [0008] For the purpose of facilitating an understanding of the subject matter sought to be protected, there are illustrated in the accompanying drawings embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages should be readily understood and appreciated. [0009] FIG. 1 is a flow chart depicting one form of a system for providing motion-picture discussion club packets. [0010] FIG. 2 is a block diagram of one form of the motion-picture discussion club packet. [0011] FIG. 3 depicts the contents of one form of the host's manual of the motion-picture discussion club packet of FIG. 2 . [0012] FIG. 4 depicts the contents of one form of the club member's topic list of the motion-picture discussion club packet of FIG. 2 . [0013] FIG. 5 depicts the contents of one form of the written interpretive comments of the motion-picture discussion club packet of FIG. 2 . [0014] FIG. 6 is a flow chart depicting the steps of one form of producing motion-picture discussion club packets of FIG. 1 . DETAILED DESCRIPTION [0015] Referring to FIG. 2 , there is shown one form of a Motion-picture Discussion Club Packet (MDCP) 200 , such as a motion picture discussion event packet. Motion-picture Discussion Club Packet 200 includes a plurality ( 12 , for example) of motion-picture media copies 201 and at least one discussion group media copy 202 . Media copies 201 and 202 each contain a copy of the motion-picture that is the subject for a motion-picture discussion event. Host media copy 202 can also include additional information, such as interviews with the director, writer, actors or producer, and is often designed to be shown at the meeting of the motion-picture discussion club. [0016] Media copies 201 and 202 can be any appropriate form of media that can be easily distributed, such as DVDs, VHS cassettes, VCDs, electronic files, electronic signals, etc. One or more of media copies ( 201 and/or 202 ), can be manufactured to allow only a single viewing, a set number of viewings, or unlimited viewings within a certain time period after activation. Such activation may occur, for example, automatically when the media copy is first viewed. [0017] In some forms, where appropriate, the Motion-picture Discussion Club Packet 200 includes a distribution apparatus, such as DVD media mailers 203 , that can be used by the host (or others) to distribute the media copies 201 to other members of a discussion club or participants in a scheduled motion-picture discussion. However, other forms of appropriate distribution apparatus can be used such as distributing electronic files of the motion-picture over a network, such as the Internet or an Intranet. In one form, emails can be sent that contain a link to a website from which the motion-picture can be downloaded. In another form, the club members could be notified of the motion-picture that will be the topic of the next meeting and the motion-picture distribution can involve each club member either renting a DVD or videotape, by downloading an electronic file of the motion-picture over the Internet or another network, ordering the motion-picture on a pay per view basis (or on-demand basis) on a cable network or satellite service, watching a scheduled showing of the motion-picture over the television airwaves, or any other appropriate method of distribution. [0018] Referring also to FIGS. 3 and 4 , a host manual 204 and club member's manual 205 can be provided in Motion-picture Discussion Club Packet 200 . Club member's manual 205 can include a club member's topic list 402 and tips for preparing for, or making the most of, Motion-picture Discussion Club Packet. Topic list 205 can include a list of topics 403 regarding certain scenes, themes, characters or other aspects of the motion-picture for discussion. It can also include a record portion 404 where the member can record notes for later use at the meeting, such as recording notes responsive to the topics and/or the members overall impression of the motion-picture. [0019] Host manual 204 can include instructions on how to host motion-picture discussion club meetings 302 , which can include tips on successfully hosting a Motion-picture Discussion Club, tips on moving the meeting and conversations along, and tips to make the overall experience more enjoyable. Host manual 204 can also include at least some of the same or similar information as that found in the club member's manual or topic list 205 , such as the same topics 403 . Additionally, host manual 204 can include additional information for the club meeting, such as a list of trivia question and/or answers 306 about the motion-picture. Host manual 204 can also include a record portion for the host to record notes, such as summaries or interpretations 304 responsive to the topics 403 . Alternatively or additionally, preprinted summaries or interpretations responsive to the topics 403 can be included in host manual 204 . [0020] Interpretive comments 207 can be included in the Motion-picture Discussion Club Packet 200 . Interpretive comments 207 can include some by those involved in the making of the particular motion-picture, such as the director's comments, the writer's comments, the actor's comments. Critic's comments could also, or alternatively, be included. The various interpretive comments 207 may include an analysis of particular themes, and/or sections or scenes in the motion-picture. In one form, interpretive comments 207 could be written and included in Host Manual 204 . In another form, the club member's manual or topic list 205 can also include these written interpretive comments 207 . In yet another form, discussion group media copy 202 may include interpretive comments 207 in either a displayed written form or can include actual interviews of the individual's giving their interpretive comments 500 . Alternatively, interpretive comments 207 can be a standalone document as shown in FIG. 2 . [0021] An opinion document 206 can be included in the Motion-picture Discussion Club Packet 200 . The opinion card can include survey questions, questions asking for specific opinions, and or a space for entering an opinion on any subject that the person who fills out opinion document 206 desires. For example, opinion document 206 can request a person suggest other motion-pictures, such as movies or series episode, to make available in another Motion-picture Discussion Club Packet 200 . In one form, opinion document 206 can include a pre-addressed postage paid mailing, such as a postcard or an envelope for returning the opinion document 206 to the manufacturer, seller or one of their agents. In another form, opinion document 206 can be a form on a webpage that a customer can fill out. In yet another form, opinion document 206 can be in the form of an electronic document, such as an email or an electronic file, that is provided to a customer. [0022] Referring to FIG. 1 , there is shown a form of the manufacturing and/or distributing 100 a Motion-picture Discussion Club Packet 200 . A production portion, or production end 101 , includes a motion-picture production operation 102 , such as any of the big movie production studios, that makes the actual motion-picture. The motion-picture then goes to a media manufacturer or a media recording entity (which can be the motion-picture production operation 101 , such as DVD manufacturer or recorder 103 , that makes copies of the motion-picture media copies 201 and the discussion group media copy 202 . These media copies 201 and 202 include copies of the motion-picture that is the subject of the motion-picture discussion club packet 200 . A printer (or publisher) prints (or publishes) the associated printed materials that are included with the discussion club packet 200 . Such materials can include the manuals 204 , 205 , media mailers 203 , opinion document 206 , interpretive comments 207 , and any artwork used on the media 201 , 202 or on the packaging for the Motion-picture Discussion Club Packet 200 . A packager/distributor 105 then packages and distributes Motion-picture Discussion Club Packet 200 . [0023] A retail portion, or retail end 106 , is also provided. In one form motion-picture discussion club host 111 , or an individual, can purchase or otherwise obtain the Motion-picture Discussion Club Packet 200 directly from the packager/distributor 105 (or even directly from the motion-picture production operation). Alternatively, discussion club host 111 can purchase or otherwise obtain the Motion-picture Discussion Club Packet 200 through various retail establishments, such as online retailers 107 , retail video stores 108 , music stores 109 , and book stores 110 . Club host 111 can then distribute media copies 201 to each of motion-picture discussion club members 112 . [0024] Referring to FIG. 6 , there is shown a method of manufacturing and distributing the motion-picture discussion club packets 200 . A motion-picture production studio produces 600 a motion-picture. Media copies 201 , 202 containing the motion-picture are produced 602 and associated containers or packaging are also produced. Media mailers 203 , manuals 204 , 205 , opinion documents 206 and/or interpretive comments 207 are written, published and/or printed 604 . The motion-picture discussion club packets 200 are assembled 606 . Then, motion-picture discussion club packets 200 are provided to motion-picture discussion club websites or individuals hosting a motion-picture discussion party through websites, retailers, on-line retailers, etc. 608 . The motion-picture discussion club packets 200 are then sold to, purchased by, or otherwise made available to motion-picture discussion clubs and individuals hosting a motion-picture discussion party or event. The motion-picture discussion club host 111 makes media copies 201 available to motion-picture club members 112 at 612 . In one form, club host 111 mails media copies 201 and manual 205 to club members 112 inside media mailers 203 . [0025] In another form, club host 111 can download electronic copies of the motion-picture over a network (such as the internet) from online retailer 107 and then distribute those copies over the same, or another, network by attaching a copy to an email and sending it to each club member 112 . In one form, the club host 111 can distribute media copies 201 by sending emails including a link and/or code for downloading a copy of the motion-picture from the online retailer over a network. [0026] In another form, the club host 111 can distribute media copies 201 by providing identifying information concerning each club member 112 and providing identifying information concerning the subject motion-picture to a commercial distributor or retailer, who then provides each club member with the ability to obtain a media copy 201 or view the motion-picture. For example, the email addresses of club members 112 could be provided to an online retailer, which then sends each an email with a link or password that allows the club member 112 to obtain a copy 201 (or access to a copy) of the motion-picture over the internet, cable network or satellite television network. Alternatively, identifying information, such as names and addresses of the club members 112 , could be provided to a television network company, such as a cable network, which then allows each of the club members 112 to obtain access to an electronic copy of the motion-picture in a manner similar to a pay per view service or on demand service. In another form, identifying information of the club members 112 could be provided to a retail video store which could then be used to reserve (and/or prepay for) media copies (such as rental copies) of the motion-picture for each club member 112 . [0027] In one form, each club may have an account or other identifying information stored by a retailer, such as Netflix. Such retailer could be provided with updated information as new members join or old members leave. The club host 111 can then provide the retailer with the club identifying information and information identifying the subject motion-picture. The retailer can then provide each club member 111 a media copy of the subject motion-picture or access to a copy of the subject motion-picture, such as by mailing them a copy of a DVD. The club members 111 may then have to eventually return the media copy at some point. [0028] In any form where a physical media copy is provided to each member for a limited period of time, such as through a video rental outlet like blockbuster or Netflix, the host may provide the retailer with a preference list of motion-pictures that are desired as the topic of a movie-discussion event. The video rental outlet (or other distributor) can then check to see if the appropriate number of copies of physical media are available for the first preference, then the second, nth, etc. until coming to the highest preference with the appropriate number of media copies available. Then the copies can be reserved for the members of the club. In one form, each member of the club could pick up a copy at the video rental outlet. In another form, the distributor would deliver a media copy to each member (from member identifying information provided by the host or from member identifying information stored on file). In a modified form involving chain video rental outlets, members identifying information and local video rental outlets or favorite video rental outlets are provided to the chain and the chain checks to see if the appropriate number of physical media are available at the neighborhood or favorite locations of each member. In other words, if each member has a different neighborhood or favorite location from each of the others, then each of such locations would only require one media copy for the particular individual in the neighborhood. [0029] Typically, individuals would form a motion-picture discussion club to hold multiple motion-picture discussion parties or events, each typically involving a different motion-picture. However, it is also contemplated that only one party or event may occur for the particular motion-picture discussion club. [0030] Typically, the club host 111 (or planner) and club members 112 (participants) would each watch the motion-picture that is the subject of the next motion-picture party or event. The club host 111 and club members 112 can then review the manuals 204 and/or 205 for instructions and to review the listed topics for discussion and make any notes. The club will then meet or otherwise communicate (such as telephonically, via email, posting on a website, etc.) to discuss the motion-picture or otherwise provide there comments and contribution to other club members. Normally, the club members will focus on the topics listed in the manuals 204 and/or 205 . After this communication or meeting, the club members can then watch the host media copy 202 to learn, for example, whether their interpretation of the movie or a particular scene matches what the director intended to convey or what another person involved in the movie or a critic thought. Interviews with the director and any of these others can be included that contains a discussion or interpretation of the section or scenes on which the club members will be instructed to focus particular attention. [0031] In one form, the motion-picture discussion club packets 200 can be marketed primarily to small clubs formed by individuals interested in viewing and then meeting to discuss classic and contemporary films. The motion-picture discussion club packets 200 could be offered for sale via a toll-free telephone number, a website or by purchase at retail outlets such as book stores (e.g. Borders, Barnes & Noble, Crown), Music stores (e.g. Tower Records, Musicland), video stores (e.g. Blockbuster, Hollywood Video) or on-line retailers (e.g. Amazon.com). [0032] The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of applicants' contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.

A discussion apparatus and method is shown that is particularly useful for holding motion-picture discussion clubs and providing the members with the motion-picture that is the subject of an upcoming motion-picture discussion event. Copies of the motion-picture are made available to each of the club members using one or more methods of distribution. Topics of conversation are provided for each of the members to focus on for the motion-picture discussion event.

CROSS-REFERENCE [0001] Copending Application (Attorney Docket No. AUS920050248US1), Ser. No. ______, Rutkowski et al, assigned to common assignee, filed ______, This reference is hereby incorporated by reference. TECHNICAL FIELD [0002] The present invention relates to data encryption, and particularly to managing encrypted content using logical partitions by associating title keys with binding information for encrypting said title keys. BACKGROUND OF RELATED ART [0003] The past decade has been marked by a technological revolution driven by the convergence of the data processing industry with the consumer electronics industry. The effect has, in turn, driven technologies that have been known and available but relatively quiescent over the years. A major one of these technologies is Internet related distribution of documents. The Web or Internet, which had quietly existed for over a generation as a loose academic and government data distribution facility, reached, “critical mass” and commenced a period of phenomenal expansion. With this expansion, businesses and consumers have direct access to all matter of documents and media through the Internet. [0004] With the advent of consumer digital technology, content such as music and movies are no longer bound to the physical media that carry them. Advances in consumer digital technology present new challenges to content owners such as record labels, studios, distribution networks, and artists who want to protect their intellectual property from unauthorized reproduction and distribution. Recent advances in broadcast encryption offer an efficient alternative to more traditional solutions based on public key cryptography. In comparison with public key methods, broadcast encryption requires orders of magnitude less computational overhead in compliant devices. Compliant devices are those which follow the key management protocol defined to govern the behavior of devices participating in a particular content protection system, and which have not been altered or used in attacks designed to compromise that system. In addition, broadcast encryption protocols are one-way, not requiring any low-level handshakes, which tend to weaken the security of copy protection schemes. However, by eliminating two-way communications, the potentially expensive return channel on a receiver may be eliminated, lowering overhead costs for device manufacturers and users. [0005] IBM has developed a content protection system based on broadcast encryption called eXtensible Content Protection, referred to as “xCP.” xCP supports a trusted domain called a ‘cluster’ that groups together a number of compliant devices. Content can freely move among these devices, but it is useless to devices that are outside the cluster. Other examples of broadcast encryption applications include Content Protection for Recordable Media (CPRM) media, Content Protection for Pre-Recorded Media (CPPM) media, and Advanced Access Content System (AACS) next-generation media. [0006] Broadcast encryption schemes bind a piece of content to a particular entity, such as a piece of media (e.g. a compact disk or DVD), a server, a group of authorized devices, or a user. Broadcast encryption binds the content by using a media key block (also known as a key management block KMB or session key block) that allows compliant devices to calculate a cryptographic key (the media or management key) using their internal device keys while preventing circumvention (non-compliant) devices from doing the same. One example of a binding scheme is binding to a specific receiver in standard PKI applications wherein content is encrypted with a session key, which is then encrypted with a receiver's public key. The content can only be retrieved with the receiver's private key. Another example of a binding scheme is binding to a specific media in CPRM and AACS Media wherein content is encrypted with a title key, which is then encrypted with a key resulting from a one-way function of a media identifier and a media key (calculated from the media key block described above). A third example of a binding scheme is binding to a specific group of devices in a user's domain, as in xCP Cluster Protocol, wherein content is encrypted with a title key, which is then encrypted with a key resulting from a one-way function of the user's cluster authorization table and binding ID and the user's current management key (calculated from the user's current media key block). [0007] Broadcast encryption does not require authentication of a device and can be implemented with symmetric encryption, allowing it to be much more efficient than public key cryptography. After calculating a media key by processing the media key block (KMB), the scheme uses the media key to bind the content to an entity with a binding identifier, resulting in the binding key. An indirection step occurs when a title key is then chosen and encrypted or decrypted with the binding key, resulting in an encrypted title key or an encrypted indirected key. The content itself may then be encrypted with the title key and the encrypted content may be stored with the encrypted title key. A compliant device that receives the encrypted content and the encrypted title key may use the same KMB and the binding identifier to decrypt the encrypted title key and then to use that title key to decrypt the content. The compliant device first must reproduce the binding key using the KMB, the binding identifier and its device keys, and then decrypt the title key from the encrypted title key using the binding key. Once the compliant device has the title key, it may decrypt the content itself. A circumvention device will not have device keys that can be used to process the KMB and thus will not be able to reproduce the binding key or be able to decrypt the content. Also, if the content has been copied to a different entity with a different identifier by a non-compliant device, the compliant device with valid device keys will not be able to calculate the correct binding key because the binding identifier is different than the original one. [0008] Under prior art systems, all content would be encrypted with a title key which would itself be encrypted with the binding key. Said content items are owned by a single participant in this key management binding scheme, and is responsible for the re-encryption of said title keys when indirections change that result in a new binding key. For example, the introduction of a new device into an existing network cluster causes an update to an authorization table, i.e. an indirection mechanism on the binding key. Ideally, implementations using broadcast encryption perform a re-encryption procedure on all title keys affected by the binding change. Optimally, re-encryption of said title keys occurs in a timely manner so as not to delay a user's access to associated content. Implementations typically attempt to re-encrypt affected title keys immediately, or without regard to use patterns. If the number of content items affected is large, as can often be the case for devices with entertainment content, the operation is time consuming and causes delay to the user. Additionally, devices that manage content can go offline or be disconnected from the network, either as a matter of normal use or due to some device failure. These failures can occur while rebinding title keys. When the device becomes reconnected, it is responsible for recovering and continuing to rebind the title keys it managed at the point it failed with no loss of content. [0009] The present invention is directed to solving this problem by providing a means to manage title keys by establishing logical partitions of title keys with the same binding information. The method of the present invention provides a means that supports delayed and background processing of title keys when binding information changes. The present invention also supports proper accounting for devices required to recover rebinding processing when devices fail or go offline unexpectedly during said processing. [0010] Therefore, there is a need for an effective and efficient system of managing encrypted content using logical partitions. SUMMARY OF THE PRESENT INVENTION [0011] The present invention provides a solution to the previously recited problems by a system, method and related computer program for managing encrypted content using logical partitions of the encrypted content's encrypted title keys. More particularly, the present invention provides a means for supporting delayed and background processing of encrypted title keys when binding information changes, as well as support proper accounting for devices recovering the state of the rebinding processing when devices fail or go offline unexpectedly during processing. The present invention controls access to and storage of encrypted content and their associated encrypted title keys by content provider service, which can partition title keys based upon binding contexts that identify the unique set of binding information used to encrypt the set of title keys in a given partition. The content provider need not store the encrypted content with their associated encrypted title keys directly as long as the content provider can maintain an association between the encrypted title key and the encrypted content. The content binding service has the ability to determine “currency” of binding information from the information contained within the binding context and is able to use the information within the context to reference the actual binding information needed to decrypt encrypted title keys. When access to encrypted content is requested the content provider identifies the logical partition of which requested content's encrypted title key is a member. The content binding service can use the binding context associated with the partition to determine if binding information used for encryption of title keys in that partition is outdated. If the context binding information is current, the encrypted title key and the encrypted content are returned to the content binding service, which decrypts the encrypted title key and then decrypts the encrypted content itself using the title. Decrypted content is then provided to a rendering service on a device. If the context binding information is outdated, the content provider requests that the content binding service re-encrypt the title key with the current set of binding information. The binding service has the ability to reference or recreate the older sets of binding information from information contained within the binding contexts associated with the partitions to which encrypted title keys belong. The content binding service can then decrypt the title with an older set of binding information and re-encrypt the title key with the current set of binding information. The content provider service can then re-partition the encrypted title key with the current set of binding information into a partition associated with the current binding context by associating the newly encrypted title key with the current partition, removing association of the content from previous partition, and monitoring remaining content associated with requested content which is in a partition with outdated content context. If a logical partition with the current binding information does not yet exist it can be created at this time. The content provider reserves the right to rebind the remaining title keys in the outdated partition to which the requested title key previously belonged or mark the partition as “outdated” and schedule the partition to rebind the remaining title keys at a later time. In the present invention, content context for partition associated with current binding information for device is retrieved via content binding service. Access to the content can also be through the content provider directly as long as the content provider has access to the content binding service to perform the same rebinding operations prior to granting access to a renderer. Please note that if the content does not need to be rendered (i.e. viewed or played), but simply transferred to other devices that have access to the same binding scheme and provides for the same processing as described within this invention, the encrypted title keys do not need to be rebound to succeed in a transfer since the other device's binding service can perform the same rebinding operations when rendering is required at a later time. This type of transfer of encrypted content can be performed by the content provider directly or indirectly via the content binding service. BRIEF DESCRIPTION OF THE DRAWINGS [0012] The present invention will be better understood and its numerous objects and advantages will become more apparent to those skilled in the art by reference to the following drawings, in conjunction with the accompanying specification, in which: [0013] FIG. 1 is a line drawing of an exemplary network architecture in which methods and systems according to embodiments of the present invention may be implemented; [0014] FIG. 2 is a generalized view of a system that may be used in the practice of the present invention; [0015] FIG. 3 is an illustrative flowchart describing setting up of the functions for managing encrypted content using logical partitions of the present invention; and [0016] FIG. 4 is a flowchart of an illustrative run of the program set up according to FIG. 3 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0017] Referring to FIG. 1 , a line drawing of exemplary network architecture is shown in which methods and systems according to embodiments of the present invention may be implemented. While the present invention is operable with various binding schemes, such as binding to a specific receiver in standard PKI applications, binding to a specific media in CPRM and AACS Media, FIG. 1 shows the binding scheme wherein the binding is to a specific user's content in xCP Cluster Protocol. The network of FIG. 1 includes an xCP compliant network cluster 32 that includes several xCP compliant network devices including a cellular telephone 18 , a television 10 , a DVD player 16 , a personal computer 14 , and an MP3 player 20 . The network may be any type of wired or wireless network, such as Local Area Network (LANS) or Wide Area Networks (WANS). Content may be any data deliverable from a source to a recipient and may be in the form of files such as an audio data file, a video data file, a media data file, a streaming media file, an application file, a text file, or a graphic. An encryption system allows receiving devices within the home network to freely share and utilize encrypted content between them while preventing non-compliant devices from decrypting the encrypted content. A receiving device may optionally be able to record content onto a recorded device for use outside the home network. [0018] The network cluster supports a key management block 38 for the cluster, an authorization table 12 that identifies all the devices currently authorized to join in the cluster, a binding key 36 for the cluster, and a cluster ID 46 . The key management block 38 is a data structure containing an encryption of a management key with every compliant device key. That is, the key management block contains a multiplicity of encrypted instances of a management key, one for every device key in the set of device keys for a device. The binding key 36 for the cluster is calculated as a cryptographic one-way function of a management key and a cryptographic hash of a cluster ID and a unique data token for the cluster. The management key for the cluster is calculated from the key management block 38 and device keys. [0019] The network of FIG. 1 includes a content server 31 that is capable of encrypting content with title keys provided to it by content providers, content owners, or a legal licensing authority. Content server 31 is also capable of calculating a binding key for a cluster, given enough information about the cluster, and using the binding key 36 to encrypt a title key and package it with encrypted contents. More particularly, content server 31 may control broadcast encryption of content for a network cluster 32 from outside the cluster by receiving from a network device in the cluster a key management block 38 for the cluster 32 , a unique data token for the cluster 32 , and an encrypted cluster ID. The content server is capable of using the key management block 38 for the cluster 32 , the unique data token for the cluster 32 , and the encrypted cluster ID to calculate the binding key for the cluster. [0020] The network of FIG. 1 further includes a digital rights server 39 that is capable of storing rights objects that define rights for the broadcast encryption content. In addition, a digital rights server 39 is also capable of calculating a binding key for a cluster, given enough information about the cluster, and using the binding key to encrypt a title key and insert it into a rights object. More particularly, if a third party DRM solution exists, the present invention is compatible with said third party DRM solution to control broadcast encryption of content for a network cluster 32 from outside the cluster by encrypting a title key with a binding key 36 , and inserting the encrypted title key into the rights object. At this point, an external check could be made to the third party DRM solution prior to making content available from a participating device. If a DRM solution is present, access is granted or denied based upon unique identification of encrypted content from the requesting device. A digital rights server may be capable of using a key management block 38 for the cluster 32 , a unique data token for the cluster 32 , and an encrypted cluster ID to calculate a binding key for the cluster. [0021] A generalized diagram of an encryption management system that may be used in the practice of the present invention is shown in FIG. 2 . The cryptographic system may be any combination of hardware and/or software that may perform one or more of such tasks as encrypting or decrypting, and attaching a key to content. A typical cryptographic system may be a general purpose computer with a computer program that, when loaded and executed, carries out the methods described herein. Alternatively, cryptographic system may be a specific use computer system containing specialized hardware for carrying out one or more of the functional tasks of the cryptographic system. A specific use computer system may be part of a receiving device, for example, such as an encryption/decryption module associated with a DVD player. Cryptographic system may include one or more central processing units (CPUs 19 ), an input/output (I/O) interface 22 , a user application 26 that includes a binding calculation object 28 wherein a context key 40 , indirection key(s) 42 , and encryption key 44 are found, external devices 24 , and a database 49 . [0022] Cryptographic system may also be in communication with a source 57 or a recipient 47 . Source 57 may be the source of any content to be encrypted or decrypted or any entity capable of sending transmissions, such as a content owner, a content service provider, or a receiver in a home network. Information received from a source 57 may include any type of information, such as encrypted content, content, content usage conditions, a KMB, encrypted title keys, or binding identifiers. Similarly, a recipient 47 may be any entity capable of receiving transmissions or that is a destination for any encrypted content or other information, such as a receiver in a home network. [0023] CPU 19 may include a single processing unit or may be distributed across one or more processing units in one or more locations, such as on a client and server or a multi-processor system. I/O interface 22 may include any system for exchanging information with an external source. External devices 24 may include any known type of external device, such as speakers, a video display, a keyboard to other user input device, or a printer. Database 49 may provide storage for information used to facilitate performance of the disclosed embodiment. Database 49 may include one or more storage devices, such as a magnetic disk drive or optional disk drive. [0024] User application 26 may include components of application specific information, such as media ID, or authorization table. Binding calculation object 28 may include a context key 40 that is set up via a user's specific information, one or more indirection keys 42 , and a final encryption key 44 used to encrypt content. The binding calculation object 28 can be reused in several various applications and is a standard defined mechanism. This standard defined mechanism can be used to create trusted entities that handle a state of a binding transaction for an application. Secret information, such as title keys, media keys, or session keys, can be kept inside these trusted entities (binding calculation objects) decreasing the security risks of transmitting sensitive information in application components. Specific measures can be taken to detect and prevent decryption of title keys outside of the trusted entities. [0025] The binding calculation object or trusted cryptography object 28 can be implemented as a trusted software component that executes in a trusted operating system environment. For example, a computer system could be supplied with a trusted Java Virtual Machine (Java is a trademark of Sun Microsystems, Inc.) whose execution options are known and controlled by the system owner. In the alternative, binding calculation object 28 can be embodied in a read only memory device or application specific hardware device to ensure that no compromising operations can be performed. The advantage is that the decrypted secret information such as the title key is always maintained in the binding object 28 with external access blocked and thus cannot be compromised. [0026] FIG. 3 is a flowchart showing the development of a process according to the present invention for managing encrypted content using logical partitions. Means are provided for managing encrypted content using logical partitions of title keys encrypted with binding information, step 70 . Means are provided for requesting access to content on a compliant device stored by content provider service, step 71 . A user can choose to manage the encrypted title keys of the encrypted content in these partitions. A user may choose to manage the encrypted content in these partitions, but can also have a reference to the encrypted content in another location. Means are provided for identifying content partition of which requested content is a member, step 72 . One binding scheme that could be used with the present invention is xCP. Means are provided for retrieving content binding context for identified partitions, step 73 . Means are provided for determining if binding context represents most current set of binding information for device, step 74 . Means are provided for restoring binding information using the content binding context, step 75 . Means are provided for allowing for rebinding title keys to current cluster binding information level, step 76 . [0027] The content binding service can allow users to provide preferences when content can optimally be rebound, e.g. at times of low usage. The provider can allow for time intervals to be set by the user that when the period occurs, a binding currency check is made for content contexts associated with content partitions it manages. Re-encryption of large sets of title keys can occur on different threads at lower priorities to match the device's processing capabilities or to defer to times when the device's processing capabilities permit. [0028] A simplified run of the process set up in FIG. 3 will now be described in with respect to the flowchart of FIG. 4 . First, a determination is made regarding whether to manage encrypted content using logical partitions, step 80 . If No, the process ends since we only describe a process using logical partitions with regard to FIG. 4 . If Yes, access is requested to content stored by content provider service, step 81 . When content is acquired by a device and stored directly or indirectly (e.g. from a content server via the content binding service) to the content provider, the content provider is always provided the encrypted content, encrypted title key, and the binding context which it can use to partition the encrypted content and encrypted title keys. It should be noted that partitions can be actual physical partitions mapped to physical storage media or logical partitions which can maintain an association to the physical location where the actual content and title keys reside. The partition is identified of which requested content is a member, step 82 . A determination is made regarding whether the binding information used for encryption of title keys is outdated using the binding context associated with that partition, step 83 . If Yes, the content provider requests that the title key encrypted with outdated binding information be re-encrypted by content binding service, step 84 . The content provider presents the outdated binding context associated with the logical partition the title key was a member of to the binding service, step 85 . The content binding service uses the outdated binding context to recover outdated binding material and uses it to decrypt the outdated title key, step 86 . The binding service then re-encrypts the title key with the current set of binding information for the cluster, step 87 . The content binding service returns the re-encrypted title key and current binding context to the content provider, step 88 . The content provider re-partitions the title key to the “current” logical partition, creating a “current” partition if one does not yet exist, step 89 , and either chooses to rebind each title key in the outdated partition or marks the partition as being outdated and defers its binding (on a schedule determined by the compliant device or user). [0029] Further in FIG. 4 , when the content provider service identifies the partition with current content context, the content and newly encrypted title key are associated with the partition. Association of the content and keys are removed from the previous partition, and remaining content associated with requested content which is in a partition with outdated content context is marked and monitored. The content binding service can comprise a notification system for the content provider service to provide real time determination of binding changes. A content provider can opt to rebind (as in steps 84 - 89 ) the title keys within partitions at the time of notification by the content binding service's notification system. Alternatively, a content provider can opt to defer rebinding title keys at the time of the notification by the content binding service's notification system flagging the partition and associated content and title keys for a future update interval. [0030] If No, the binding information used for encryption of title keys is not outdated, then the encrypted title key and encrypted content is returned to content binding service, step 90 , and title key is decrypted by content binding service with current binding information, step 91 . Then the decrypted title key is used to decrypt the content itself, step 92 . Decrypted content is provided to the rendering service (including but not limited to audio and/or video) on the compliant device (e.g. DVD player, MP3 player, or the like), step 93 , then the process ends. [0031] The present invention is described in this specification in terms of methods for the secure and convenient handling of cryptographic binding state information. One skilled in the art should appreciate that the processes controlling the present invention are capable of being distributed in the form of computer readable media of a variety of forms. The invention may also be embodied in a computer program product, such as a diskette or other recording medium, for use with any suitable data processing system. Embodiments of a computer program product may be implemented by use of any recording medium for machine-readable information, including magnetic media, optical media, or other suitable media. Persons skilled in the art will immediately recognize that any computer system having suitable programming means will be capable of executing the steps of the method of the invention as embodied in a program product. Although certain preferred embodiments have been shown and described, it will be understood that many changes and modifications may be made therein without departing from the scope and intent of the appended claims.

The present invention provides a means for managing title keys by establishing logical partitions of title keys encrypted with the same binding information. The invention supports delayed and background processing of title keys when binding information changes. This invention supports proper accounting for devices required to recover rebinding processing when devices fail or go offline unexpectedly during processing. The invention uses binding context which represents a set of data that can be used to determine if the binding information used to encrypt a set of title keys is outdated and allow for rebinding to the current cluster binding information level.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of and claims the benefit of the priority of U.S. patent application Ser. No. 10/624,085, filed Jul. 21, 2003, and entitled “SYSTEM AND METHOD FOR AN ADAPTIVE USER COMMUNICATIONS DEVICE,” which claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 60/398,215 entitled “SYSTEM AND METHOD FOR AN ADAPTIVE USER COMMUNICATIONS DEVICE” filed Jul. 23, 2002, each of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention relates to the adaptive behavior in a communications device, and, more specifically, to the personalization of, and targeting of content, such as advertisements, to, a mobile communication device. [0004] 2. Description of the Background [0005] The sending of messages, content, and/or advertisements for products and services to potential consumers, such as via handheld wireless communication devices, is well known. These messages, content, and/or advertisements are, in general, sent with the hope that the received message, content, or advertisement will be relevant to the needs of the handheld wireless device user, and thus will generate a desired response from the user, such as by a purchase by the user of the advertised product. Messages or content may be targeted to a potential consumer based, for example, on the location of the wireless device. These messages may provide the consumer with advertisements for the local community wherein the handheld wireless device is located, for example. [0006] Unfortunately, messages and advertisements may be ignored by the potential customer due to a lack of then-current interest in the product or service. This may result from a poor selection of messages and/or advertisements, such as messages and/or advertisements for products or services that the potential consumer does not need or desire. Improvement to the targeting is necessary to more effectively select messages that have a greater probability of being favorably received by the consumer. This improvement in targeting necessitates an increased knowledge of the potential customer's buying habits, interests, background, advertising responsiveness, location, and schedule. [0007] Thus, a need exists to improve knowledge of a customer's buying habits, interests, background, advertising responsiveness, location, schedule, and propensities in order to more effectively target messages and/or advertisements to the customer operating a communications device. SUMMARY OF THE INVENTION [0008] A targeting system for adapting a device to a user is disclosed. The targeting system includes at least one communications device in communication with at least one network, a virtual database accessible to at least one of the at least one communications device over the at least one network, and a searcher that provides content to the communications device over the at least one network, in accordance with the virtual database. The at least one communications device may include a wireless communications device. [0009] A communication network for providing a personalized targeted message to a user is disclosed. The network includes a communications device operated by the user, a virtual database including at least one characteristic about the user, a searcher having access to a plurality of targeted messages and to the virtual database, wherein the searcher filters at least one of the targeted messages that is of interest to the user according to at least one of the at least one characteristics, and wherein the searcher communicates the at least one targeted message of interest to the communications device for provision to the user. [0010] A method of targeting content to a user of a communications devices is disclosed. The method includes building a virtual database of information regarding the user, modeling at least one probabilistic behavior of the user, in accordance with the virtual database, searching for content targeted to the at least one modeled probabilistic behavior, and providing the content to the communications device. [0011] Thus, the present invention provides improved knowledge of a customer's buying habits, interests, background, advertising responsiveness, location, schedule, and propensities in order to more effectively target messages, content, and/or advertisements to the customer operating a communications device. BRIEF DESCRIPTION OF THE DRAWINGS [0012] Understanding of the present invention will be facilitated by consideration of the following detailed description of the present invention taken in conjunction with the accompanying drawings, in which like numerals refer to like parts, and wherein: [0013] FIG. 1 is a block diagram of the present invention; [0014] FIG. 2 is a block diagram of the present invention; [0015] FIG. 3 is a block diagram of the present invention; and [0016] FIG. 4 is a flow diagram of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0017] It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, many other elements found in a typical communications system and method. Those of ordinary skill in the art will recognize that other elements are desirable and/or required in order to implement the present invention. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein. [0018] FIG. 1 is a block diagram illustrating a targeting system for adapting a device to a user. The targeting system may include a communications device in communication with a network, such as an internet, an intranet, a direct dial-in network, a wireless network, or the like, a virtual database, which may include a heuristic modeler, a virtual searcher, and a content filter. [0019] The communication device 102 , 108 , 124 displays personalized messages, content, and/or advertisements to the user of the device. The communication device may be a computer, television, wireless device, or the like, for example. The wireless device 108 may be, for example, a cellular telephone, a programmable digital assistant, a short range wireless device, or other wireless device, such as a web-enabled wireless device. The wireless device 108 may preferably be a mobile, hand-held device, although it may be a laptop computer having a wireless modem, for example. Additionally, the communications device may be a terminal-only device, such as a television set or network terminal. [0020] Use of the communication device 102 , 108 , 124 may populate the virtual database 104 , which may include a heuristic modeler. A virtual database, as used herein, may include, for example, a database, a relational database, a database server, a server farm, or the like. Searcher 126 produces information relevant to the user in accordance with information in database 104 . Information may be entered into the virtual database 104 over network 106 , such as by the user, such as via a personal computer, or other type of computer terminal, connecting to a network access point, such as access point 103 , 125 , such as an internet connection, and thereby connecting to network 106 . A virtual database interface 105 may communicatively connect the virtual database to the network 106 , via, for example, a one or a two way communicative connection. It should be noted that although the network 106 is shown as a single line with a distinct number of nodes, it will be apparent to one skilled in the art that a network, such as the internet, may have a great number of available nodes, ports and/or lines. For example, the user may, via the network 106 , log onto a site that is associated with and/or communicatively connected to the virtual database 104 via any available methodology, and may subsequently be allowed to generate a personal profile for storage into the virtual database 104 . More specifically, for example, the user may communicate with the virtual database 104 via the air interface link 114 via the wireless base station 110 via the network 106 . The air interface link may be, for example, an RF, optical, or other format or protocol known to those of skill in the art. [0021] Information about a device, such as wireless device 108 , may be exchanged between an intermediary, such as the wireless base station 110 , and a time and location monitor 116 , via a link 118 . It will be apparent to those skilled in the art that link 118 may be a wired link, wherein the time and location monitor is co-located with, for example, the base station 110 , or may be a networked or wireless link. The time and location monitor 116 may provide time and/or location information to the virtual database 104 over a link, such as link 120 , as will be apparent to those skilled in the art. This time and/or location information may relate to the then-current time and location of a device, such as wireless device, as assessed at the wireless device 108 , or at the at least one base station 110 , or may relate to a batched history of time and/or location information for at least one device, such as wireless device 108 . Time and/or location information may include times of telephone operation, time of calls, time of calls to particular numbers, and/or time of calls for particularly assessed purposes, or time of internet use, or time of internet sites visited, or times of television watching, or particular television programs watched at particular times, or particular channels watched at particular times, and/or location at which, or to which, activities occur, thereby allowing for the virtual database 104 to include time and position sensitive information, such as patterns of travel over time, or approximate hours of awakening, sleeping, working, playing, and the like, or when, to where, how often, and to whom cellular calls are made, or emails are sent, for example. [0022] Time and location monitor 116 is an exemplary embodiment of a monitoring device 122 . A monitoring device 122 may include, for example, a web-enabled device, or a wireless device, or a T 1 or other hard-wired connection device, such as a television channel monitoring device, to record the activity on a television 124 in order to provide information on viewing habits, for example, or a telephone monitor to record telephonic activity, such as over a landline telephone 124 , or an internet monitor to record internet viewing habits over a computer 124 , or a purchasing monitor, such as a credit card machine 124 , to track purchases at a particular store or stores by a particular user or users, or a monitor to track inter-relations between users, such as by telephone or over the internet. Communications device, such as device 124 , may provide data to the monitoring device 122 via a link, such as link 123 , via, for example, a wireless or a hard-wired connection. Monitoring device 122 may provide data to the virtual database 104 via link 125 , such as an internet link 125 through the network 106 . A networked link, or a non-wired link, or a non-networked link, including an RF or optical link, may couple the monitor 122 to the virtual database 104 . The data provided may include, for example, portions of television programs, or television advertisements or internet advertisements, viewed, skipped over, or fast-forwarded through, such as via the use of tracking technologies, such as TiVo®, for example. Device monitors will be apparent to those of ordinary skill in the art, and each device monitor may include therein, for example, at least one database, such as a relational database, and/or at least one storage memory, and/or at least one batching memory. [0023] Virtual database 104 may include therein a plurality of memories, processors, databases, comparators, or models, such as at least one overall model of at least one user, for example. Virtual database 104 may house data collected from user input on communications devices 108 , 102 , 124 , and/or data on actual transactions of the user using the devices, as assessed via monitors 116 , 122 . The virtual database 104 may additionally include user profile information, wherein the user is uniquely known based on the user profile information, and wherein the profile information is entered by the user, such as in response to a series of registration questions to register for wireless service, or Internet service, or internet site and/or over a wireless device, or wherein the profile information is entered, for example, by a registration agent receiving information from a registering user. User information may include the name, address, date of birth, marital status, economic, social, education, and/or responses to additional questions that will be apparent to those skilled in the art. Alternatively, the use of user profile questions may be minimized in an embodiment wherein certain user information may be hueristically estimated, as set forth further hereinbelow, or wherein the maintenance of detailed personal information is not desired. For example, in certain embodiments of the invention herein, detailed personal information necessary may be minimized, such as wherein the invention employs only age, or only location, or only time information to make decisions on the needs and/or desires of the user, such as decisions on desired searches of the user. Data forwarded to the database 104 may be permanently stored, or may be real time cached, such that actual incoming data is stored only for a time period necessary to update an overall model within the virtual database, as set forth more fully hereinbelow. [0024] Questions may be posed from and/or by the virtual database 104 to discover information and trends about buying habits or interests, such as questions inquiring about the typical mode of dress, or hobbies, for a user. Questions may additionally include the time, content and location of meals normally eaten by the user, or the time and location of hobbies that the user enjoys, for example. Questions may additionally include the timing, location, and frequency of services that the user usually employs, such as hair care, automobile maintenance, home improvement or maintenance, dry cleaning, food service, pet grooming, home or office cleaning, and/or banking services, for example. Additional questions may include the geography and timing of daily travels, such as a work and home location, or repetitious visitations to friends, family, business associates, and the like. Questions may, for example, assess specific tastes in certain products, such as shoes, clothing, meals, housing, types of flowers or other gifts for family, friends, or business associates, or the special dates that the user may deem important such as birthdates, anniversaries, graduation dates, vacations and holidays. Other question types will be apparent to those skilled in the art. [0025] Responses to questions may be permanently stored, such that questions need not be responded to repeatedly, and questions may be updated, or new questions may be added, periodically. Alternatively, question responses may be used only to build an overall model, as discussed hereinbelow, and those responses that change or contribute to the overall model may not be stored apart from the changes to the overall model. Additionally, as set forth hereinabove and hereinbelow, certain questions may be eliminated in an embodiment wherein responses to certain questions may be heuristically estimated, or questions may be minimized or eliminated in an embodiment wherein minimal information is necessary, or wherein a majority of information is automatically or heuristically provided, in order to provide the overall model for selection of a particular search. For example, a user may be located as to time and geography, as set forth hereinabove, and may be asked only whether the user is hungry. If the user replies with a restaurant suggestion request, or if the user automatically receives a restaurant suggestion message in response to a “Yes, I am hungry” response, and/or positively responds by engaging in eating at the suggested restaurant, as assessed by a device monitor, the overall model of that person as a late night eater may be updated, and the actual time, location, and positive restaurant response may, or may not, be permanently stored, or real-time cached for a period sufficient to allow for an updating of the overall model to include “late-night eater”. [0026] It will be apparent to those skilled in the art that privacy of profile information is protected in the present invention, using methodologies known to those skilled in the art. For example, the information provided to the virtual database is preferably not directly accessible outside of services provided by the present invention, or outside of those providing the services and/or apparatus of the present invention, to thereby ensure privacy of information, and may, in certain embodiments, not be forwarded to third parties for purposes not approved by a user. Information may additionally be protected, for example, through the use of data encrypting or proxy servers, such as over links, including those links between network 106 and virtual database 104 . [0027] The virtual database 104 thus may include personal habit, travel, buying, and other highly tailored information criteria for each user within the database 104 , to thereby allow for targeting by searcher 126 , or may include minimal information necessary to identify at least one user for message targeting by searcher 126 . If the user does not provide all necessary and/or desired information to the database 104 , such as wherein the user is reluctant to provide such information, heuristic model within and/or in communication with the database 104 may collect behavioral data of the user via the communicative transactions with the communication monitors 116 , 122 , for example, or may access generally available data, and may use this information to estimate user responses to unanswered and/or unasked questions. The heuristic model adaptively modifies the virtual database 104 , in accordance with user behavior, such as in accordance with known similar behavior patterns. The heuristic model adapts the virtual database 104 to the actual transactional behavior of the user, or to an estimated transactional behavior based upon the actual transactional behavior. For example, by knowing the location of the home and office of a user, the heuristic model may estimate a route that the user may travel from office to home, and thereby may prompt generation of a traffic alert message to that user in accordance with traffic information assessed, for example, via the searcher 126 , in accordance with the heuristically generated data, as set forth more fully hereinbelow. The heuristic model may include, for example, a plurality of databases including heuristic data, accessible to at least one database including user specific data, which access may be provided relationally, such as through a comparator, for example. [0028] Referring now to FIG. 2 , a block diagram is shown illustrating, with more particularity, a virtual database 104 for use in the system of FIG. 1 . The database of FIG. 2 includes a plurality of network and/or device interfaces 204 , 206 , 212 , a searcher interface 208 , a storage database 210 , and a controller 202 . [0029] The controller 202 may control operation of the virtual database 104 , and entry of information passing to the virtual database into storage database 210 . The controller may be a controller known to those skilled in the art, such as a DSP, comparator, bus controller, or the like, for example. The controller may be resident as hardware or software, as will be apparent to those skilled in the art, and may be programmable. The controller 202 accesses data from at least one data source within, and/or associated with, the virtual database 104 . For example, the storage database 210 is controlled by controller 202 , and may include data entered by a user, and/or data obtained via the transaction monitors 122 , 116 , and/or may include an overall model of the user, and/or may include a cache for the temporary storage of incoming information. The cache may retain the data within the storage database at least until the updating of the overall model. The user may enter data via the controller 202 by, for example, entry over a network interface 204 , such as by typing or voice over-IP, or entry over a wireless interface 206 , such as by voice recognition or keypad entry on a cellular telephone 108 . Data entry may be performed by the user in response to a data entry menu, or similar data entry request. A data entry request may be presented to the user upon a first use of a device, such as in response to entry of a username and/or password, or upon each use of the device. The data entry menu may provide for multiple choice answers, or multiple choice selections, for at least one polling questions, such as “are you hungry: Y or N?”, and answers may be selected by click and select, by key press, by a drop down menu, and/or by voice recognition. The data entry menu may allow for entry of any data, such as by text response, numeric response, or speaking response. Data entry may include, for example, a direct data entry, a user request for search entry, or modification of current data by the user. [0030] Network interface 204 may be in communication with controller 202 , and may be connected via link 105 to provide access to information entered, for example, by the user, such as from a personal computer or a device monitor. Controller 202 may accept information from a wireless communication device via, for example, link 112 and the wireless data interface 206 , as interactive input, as entered data, or as data batched data at, or directly from, a device monitor, such as a base station 110 or a time and location monitor 116 . Controller 202 may additionally accept information from the time and location monitor 116 via a dedicated time and location interface 212 , such as time and location of at least one transaction. This time and location may be assessed directly, or over the network, by the monitor 116 . [0031] For example, the user may utilize the wireless device to access profile information and enter a preference for black shoes to be purchased every 2 months. If the user is to receive a targeted message about a particular item, such as, for example, the shoes, the user may enter the word “shoes” into the wireless device, and interface 206 may accept that information as a search request data entry, pass the information to the search interface 208 , and may accept a returned messages from the searcher 126 , wherein a tailored message or advertisement is returned to the user in accordance with black shoes, and may additionally be targeted at a shoe purchase within two months of a previous shoe purchase. This information may additionally be generated heuristically, such as wherein the heuristic model within the virtual database 104 assesses that the user makes a call from a location proximate to a given shoe store approximately every two months, and, according to the transaction monitor 122 , purchases black shoes every two months, and therefore the user is estimated to purchase black shoes from that given shoe store every two months, thus necessitating a targeted message from searcher 126 regarding those shoes in that time frame at that location. A search for targeted messages may be performed by searcher 126 , in accordance with the information, in order to locate black shoes on sale at that store in the two month interval, and in order to convey the results of that search to the user. Alternatively, if the targeted message sent to the user was confirmed as received by the user, and was recorded as acted upon by the user, such as by the monitoring of a purchase transaction, that selection may be entered as a preference in the storage database 210 , such as by entry into the overall model for that user. [0032] The controller 202 and/or the storage database 210 may include therewithin a simulator of human responses, such as a heuristic modeler 226 . This heuristic modeler 226 may be programmed as software, and may have associated therewith a plurality of comparison information, or may include hardware, such as a comparator, in conjunction with the programming, or may reside in hardware only. In the example hereinabove, the controller may cause a simulation of selection of data, which selection may be based on known user preferences, and may interpret that simulated selection data in order to predict the actions of a person associated with those known preferences in the storage database 210 . Heuristic predictions may thus be based on the data gathered by the user input, and/or user transaction monitoring, entered by controller 202 to storage database 210 . For example, for a user that has entered that a hobby is baseball, and/or that has recently purchased a baseball card for a player on the San Diego Padres baseball team, and/or that frequently watches or listens to San Diego Padres baseball game telecasts on radio, television, or internet, according to the transaction monitoring, and that is then-present in San Diego, according to the time and location monitor, the controller 202 may cause the storage database to assess that the user is a fan of Padres baseball, by comparison to data of other parties that engage in similar transactions, and may consequently cause, via searcher interface 208 , a search to be performed by searcher 126 as to whether the Padres are playing a game, that day, in San Diego. If that search results in an affirmative response, a targeted message may be sent to that user suggesting a trip to a Padres game that evening. [0033] The heuristic model may be co-located in the controller 202 and the storage database 210 , and may include a plurality of predictive rules as to human behavior. The heuristic model may accept direct data, as well as monitored data obtained by monitoring the transactions, locations, such as times of transmissions and/or transactions from and by the user, such as from the wireless device 108 . In an exemplary embodiment, a weighting may be assigned to actual direct data and transaction monitoring data, such as approximately 80% for a particular user, in the overall model. This percentage may be dependent, for example, on the amount of information about that user currently available within the storage database 210 . For example, if only two data items are present with respect to a particular user, and wherein ten data items are desired for the overall model, the 80% weighting may be adjusted to reflect that only 20% of the direct data desired is available. In such an embodiment, the 80% weighting might be adjusted to a 16% weight (80%×20%). The remaining percentage of the overall model may be heuristically defined, such as by the application of the plurality of predictive rules within the storage database 210 and/or the controller 202 , by the controller 202 , to the direct and monitored data. The predictive rules may include, for example, data on known general behavioral patterns of other persons, which general behavioral data may be gained by data entry to the controller, such as by a system controller, by monitoring, such as over the Internet, by financial monitoring, such as monitoring of all purchases by a category of persons, or by monitoring of multiple users of the system of the present invention, for example. The overall model may thus be used to generate a probabilistically desirable search for the searcher 126 on behalf of the user. [0034] Probabilistic entries may, for example, be generated by subjecting to a statistical probability analysis, as will be known to those skilled in the art, data resident in the storage database 210 , as compared to, for example, the predictive rules on general behavior. For example, a plurality of statistical databases may be included in the storage database 210 , and such databases may be relational in form. For example, an entry may be made that includes information that 80% of all persons interested in art are also interested in theater. This probabilistic data may be entered, via the controller 202 , to the storage database 210 by, for example, a controller interface, wherein the relations and the data entered are of interest to the targeted message generators, such as vendors. These relations of interest may be directly entered by a targeted message generator programmer, or by at least one vendor via a vendor access 129 , for example, or may be assessed via, for example, an automated Internet data search, such as a spidering search. [0035] In the example hereinabove, the monitor 116 may repeatedly locate a user as being within a local art museum, such as by monitoring cell phone call origination location, or by monitoring purchase of museum tickets, for example. This repeated locating may implicate a rule that, if a user is assessed as being at an art museum more than twice in a two week time period, that user is interested in art. The controller may then apply the heuristic rule stated hereinabove to assess that there is an 80% chance that the particular user repeatedly located in the art museum is also interested in theater, and, in response to this high probability, the controller may generate a command to the searcher to search for theater performances at a given time, such as 30 minutes after the museum closes, in a given area, such as within 2 miles of the art museum. Thus, the predictive rule may not only be implicated, but additionally may be “intelligently” applied in a manner to allow for sufficient time for a then-current activity to end, or sufficient time for user convenience, such as by assessing the proximity of the two perceived locations of interest. For example, the heuristic rule may state that 80% of all persons eat dinner between 6 pm and 8 pm, and that 90% of all art museum patrons have an annual salary in excess of $60,000, and that 70% of all patrons of 4 star and 5 star restaurants also have an annual salary in excess of $60,000, and that 90% of all art museums close between 5 pm and 6 pm, and, consequently, that there is a 45% probability (80%×90%×70%×90%) that a search should be generated for a targeted message to the current user at the museum for a or 5 star restaurant, within 5 miles of the art museum, between 6 pm and 7 pm. This heuristic model that contributes to the overall model may additionally include limitations as to minimum probabilities, such as 50% or greater, before a search is allowed to be generated. [0036] For example, the heuristic modeler may include a series of inter-related relational databases. An actual user characteristic obtained from the user, and/or via device monitor may be used to locate a high probability event in a first database. Location of a high probability event in the first database may cause the location, within the storage database, of relationally high probability events in that first database, or other of the inter-related databases. [0037] In an exemplary embodiment, data may be taken as to the location of a user at certain times of the day, week or month. If the time and location of the user is assessed as periodic, statistical analysis may draw a conclusion from the data, and may enter the conclusion as new data into the storage database 210 . That is, if the data indicates that it is statistically significant that a user will be in a certain location at a specific day and time, that conclusion may be entered into the storage database 210 as data associated with an appropriate probability. That data and the resulting probability of that event may then be accessed as included in an overall model by the search engine 126 . [0038] In general, the highest probability of success for a targeted message occurs if the location or interests or needs or desires of the user can be predicted at a specific time, and if only the most relevant messages are transmitted to the user at, or slightly prior to, that predicted time. Thus, heuristic model statistical analysis within the overall model in the storage database 210 may be used to predict the locations, interests, needs, and/or desires of the user to within a specific probability, and to target messages accordingly. Should the user engage in behavior not predicted by the heuristic model of the overall model, the probability of the predicted event may be adjusted appropriately based upon the actual user behavior recorded in the direct and monitored data of the overall model within the storage database 210 . [0039] A Kalman filter predictor predicts the error of a prediction as compared to data actually encountered. In the case of the virtual database 104 , the error of a prediction is in the occurrence or non-occurrence of a user engaging in a predicted transaction, or the user being at a predicted location. If the user changes patterns significantly, the heuristic estimations and the probability of the estimated occurrence may be corrected to bring the prediction within acceptable error, such as in accordance with known Kalman filters. Also in accordance with known error prediction filters, the predictive error decreases as more actual observation data is gained in the present invention. [0040] In general, select types of user periodic behavior may be predicted with very high accuracy through the use of the present invention, and such high accuracy periodic behaviors may improve the predictive error of other behaviors. For example, the occurrence of anniversaries and birthdates for family, friends, and business associates, once known to the storage database 210 , can be predicted with high accuracy, and are predictably recurrent. As such, these events may have a probability of nearly 1.0 within the overall model. In an exemplary embodiment wherein an anniversary occurs on October 25, and flowers are purchased for two consecutive anniversaries, the recurrent nature of the anniversary allows for a high probability prediction that the anniversary will occur again on the following October 25, and the monitored behavior leads to a prediction that flowers will be desired, and, as such, a direction may be forwarded via the searcher interface 208 to search for messages regarding flowers, such as in a then-current location of the user. [0041] The controller 202 may sort, classify, and/or store data entered by the user, and entered by the transaction monitors. The controller 202 may additionally cause the generation of, sort, classify, and/or store, predictive data resulting from the transactions of the user, and the probabilities related thereto. These actions of the controller form the overall model of the particular user in virtual space, which virtual user is stored in the storage database 210 . The stored data of the storage database 210 may be used to generate messages through delegation by the controller 202 to the searcher 126 . In order to generate a delegation to the searcher, the controller 202 utilizes the searcher interface 208 , via link 128 , to access the searcher. The controller may be in communication with the monitor interfaces 204 , 206 , 212 , and the searcher interface 208 , over, for example, a bus architecture including a bus 214 with interfaces 215 a - f , thereby providing direct access by the monitor interfaces and the searcher interface to the overall model in the storage database 210 . [0042] As set forth hereinabove, the storage database 210 , in conjunction with controller 202 , may allow for a plurality of input modes, selectable by the data gatherer, or by the user. In a data input mode, the user may add, delete, or modify user data in the storage database 210 . A menu for the user may be presented by the controller in accordance with the selected input mode, and may allow the user to select the category of information that the user wishes to change or enter. Once a data category is selected, the user may be provided with any existing data for review. The user may then enter new or modified information, using methodologies apparent to those skilled in the art, such as a mouse, keyboard, keypad, stylus, or voice, for example, on a networked computer, personal digital assistant, or wireless communications device, for example. Other data entry formats and methodologies will be apparent to those skilled in the art. [0043] In a message request mode, or search mode, the user may wish to make a query. It should be noted that, wherein the user enters a query, the controller may forward the request to the searcher via the searcher interface 208 , similarly to an embodiment wherein a search request is hueristically generated. The transference of the query to the searcher from the controller 202 is preferably transparent to the user. The user may enter a specific, or a general, message request, via interfaces known to those skilled in the art, which request may be forwarded to controller 202 via device interfaces 204 , 206 . For example, the user may enter a request for an advertisement for “pizza”. The nearest pizza parlor to the then-current location of the user, that is open at the current time, as assessed, for example, via the time and location monitor 116 over the interface 212 , that can accommodate the user, might then be returned from the searcher 126 , via interfaces 208 and 206 , in response to the query. Additionally, for example, if the user entered the word “suit”, a targeted message regarding a suit from a local retailer might be provided, wherein the location of the local retailer, the hours of operation of the retailer, and the type of suit available from the retailer might be in accordance with the overall model. [0044] Returning now to FIG. 1 , the present invention processes a message request via the searcher 126 , which message request may be controlled directly by the user, and/or may be controlled in accordance with the overall model, and via the controller 202 , as set forth hereinabove. Vendor data access 129 is also preferably in communication with, and/or exerts control over, the virtual database 104 . [0045] Vendor data access 129 may include information for messages and advertisements, as entered and/or controlled by vendors, and is preferably accessible by searcher 126 via link 127 . Vendor data access 129 may include, for example, databases, such as in relational format, links, such as internet links or hyper-links, or other textual information. Vendor data access 129 may be a compilation of vendor supplied data that is available for searcher 126 use, and the vendor data therein may be prioritized for return in a search by searcher 126 . For example, each participating vendor may pay a fee, and the amount of the fee paid may allow a vendor access to vendor data access 129 , or may cause a particular vendor to be returned in the first position in response to a particular search, a particular vendor to be returned second, and so on. Thus, particular vendors may have a “most favored”, or a “more favored” status. Vendors subscribing may provide specific messages, and/or may provide basic data for generation of messages by searcher 126 . A vendor may provide data, for example, via a network connection to a network site 132 , or via an alternative link 134 , such as a wireless link, such that a vendor may push data into the vendor data access. Alternatively, the vendor data access 129 may query the vendor via connections 132 , 134 for updated messages. Links 132 , 134 may tie one or more vendors to a private or semi-private network, such as for vendor data polling. Additionally, vendors may enter particular characteristics of users to which the vendors wish to target messages, such as particular characteristics in storage database 210 . More current data, and more current targeting data, from a vendor will, in general, generate a more positive response by users to messages from vendors. [0046] Searcher 126 preferably utilizes the overall model to respond to, and/or to predict, the needs or desires of the user. For example, if it is known by the storage database 210 that the user gets a haircut once every five weeks, a prediction may be made in the overall model within the virtual database 104 as to when the next haircut is needed, and a search may be generated for the searcher 126 , either automatically, such as every 4 weeks, or in accordance with a user request. The search generated may be for any haircut vendors, such as by accessing an internet search or an internet search engine by searcher 126 , for any hair cut vendors having a targeted message, for local vendors having a targeted messages, or for any local vendors, and may particularly be for local vendors offering specific discounts, and/or for local vendors within 5 miles of the home of the user, or local vendors within 5 miles of the then-current location of the user, and/or local vendors specializing in a particular style of haircut, for example. The instructions for these priorities for the search are forwarded by the controller 202 , and may be in accordance with user instructions, and/or in accordance with data in the storage database 210 entered by the user and/or heuristically generated, such as data in the overall model. [0047] Matching results, having sufficient probabilities, may be returned by the searcher 126 . The searcher 126 may present all matching results, or may weight results for presentation, or may weight results for pseudo-random selection. For example, a first matching result may receive two points for return, due to the payment of a higher fee by the providing vendor, for example, and second and third vendors may each receive one point for return, due to the payment of lower fees by the providing respective vendors. Thus, in an embodiment wherein a single message is to be returned, the first vendor may have a 50% chance of random selection (2 points out of 4 total), and the second and third vendors may each have a 25% chance of selection (1 point each out of the 4 total). [0048] FIG. 3 is a block diagram illustrating an exemplary embodiment of the searcher 126 . The searcher 126 is accessible to, and may be controlled by, virtual database 104 . The searcher 126 may include filter 302 that identifies messages relevant to an inquiry, and that may tailor messages to a particular request or to a particular user profile. The filter 302 accesses vendor data or basic message information from subscribing vendors at vendor access 129 via the vendor data interface 304 , and may access generally available information, such as internet information, over interface 306 . The internet interface 306 may be utilized to access general information from the internet such as weather information, transportation schedules, and accident reports, either by a search performed by filter 302 , or by accessing available Internet search engines known to those skilled in the art. Data that is accessed may be placed into memory 308 for accessibility, such as for subsequent searches, in order to expedite those subsequent searches. Memory 308 may be any memory apparent to those skilled in the art, such as a cache, RAM, ROM, or the like. [0049] The virtual database interface 310 of searcher 126 may communicate with the virtual database 104 via link 128 , and may communicate directly with storage database 210 . Link 128 may include a buffer for buffering requested, or pushed, user data. A message buffer 312 may store, include, or construct a message, or a targeted message, from a vendor or other data source. A bus 313 using links 313 a - f may be used to interconnect the elements of the searcher 126 . [0050] The filter 302 may scan available resources, such as vendor services, and may locate opportunities for advertisements or messages in accordance with instructions received from controller 202 . It will be apparent to those skilled in the art that searcher 126 may include a controller independent from controller 202 , or that controller 202 may be included entirely within, or partially within, the searcher, rather than entirely within the virtual database 104 . The filter 302 may filter search results in accordance with additional received instructions, in addition to the search instruction or request, such as time, date, location, hours of operation, or transaction type constraints, which additional instructions may be accessed from vendor-entered data, such as in a database separate from search instructions. The filter 302 may acquire these additional instructions at any time prior to, or simultaneously with, generation of a search result, such as upon entry by the user, or by a vendor, upon assessment by a device monitor, or concurrently with receipt of the search instruction. In an embodiment wherein the additional instructions are received prior to the search instruction, the additional instructions may be stored in the message buffer 312 . In an exemplary embodiment of additional instructions, the time and location of the user, and the location of at least one vendor, and the operating hours of that vendor, may be necessary in order to assess the availability of vendor messages from that vendor to that user on a search topic. For example, additional instructions may include that messages may be available, with priority granted to the most current messages, such that the current time and location of the user may optimally be proximate to the location and operating hours of the vendor or the services. [0051] Thus, available vendor messages may be matched with a location and the time of day, and/or with other additional instructions, and/or with at least one aspect of the overall model in the virtual database 104 , in order to match a potential message with the needs and/or desires of the user. As user response to messages may be tracked by the vendors, such as by the device monitors, vendor access 129 may additionally be used to indirectly and continuously update the overall model in virtual database 104 . Further, the filter 302 may match a message against a probability of success of that message, based upon a perceived success of other or similar messages, in order to select a message. A high probability is indicative of a high likelihood that the message may be favorably received by the user. For example, the messages having the highest probability of success may receive a highest priority for transmission to the user. [0052] FIG. 4 is a flow diagram illustrating an exemplary heuristic method of performing message searches. The method begins 400 with the building of the virtual database and overall model. The user may log into a personal site to enter user information, and a controller may accept the data entries of the personal data 402 , and may store that information into the virtual database 410 . The information in the virtual database may be analyzed 412 , and transactional habit and personal preference data and events may be extracted or extrapolated by a heuristic model. The probability associated with a new behavior is calculated and appended to the derived data 418 , and the virtual data base and overall model are updated 420 . Alternatively, an input may be accepted from the device information 404 , and time and location information 406 may be acquired. Time and location may be stored in the virtual database, or may be interactively exchanged to assess whether and/or when and/or where the user seeks to make a direct request for information 408 . [0053] If a direct request is made 408 , the controller may provide an interactive dialogue with the user on the wireless device. This interactive exchange may include the presentation of mode selection 422 , or the acceptance of instructions for a topical or terminology search. If a search is requested, then a searcher may assume control of the exchange 424 in order to provide search functions. [0054] FIG. 5 is a flow diagram illustrating a heuristic methodology for use in the present invention. Upon initiation 500 , the controller assesses user time and location, and/or transaction, information 502 . The searcher may be initiated automatically when the user device monitored in step 502 is activated. Activation may be defined as a turning-on, or the transmittal of a user action, such as a search, or a call or dial-in. The controller may access vendor messages 504 via, for example, a vendor data access point. The time and location and/or transactional data may be compared 506 with the available vendor messages, and a determination off message applicability may then be made. If the comparison results in a potential message, the virtual model 508 may be accessed to gain insight into the applicability of the message to that user. The results are compared 510 , and if a favorable match to the profile is available, the probability of success 512 of the message may be assessed. [0055] If the probability of a successful event is sufficiently high, the message may be constructed 514 and sent to the user communication device 516 . Upon selection of a message, the message may be personalized for the preferences or the needs of the user. For example, the format of the message may be adjusted to fit the display of the user communications device during construction 514 or issuance 516 . After the message is sent, the response by the user is awaited 518 for success or failure, such as by monitoring a transaction monitor at the vendor associated with the message, or by querying the user to assess an interest level of the user, to thereby provide system feedback. If received, the feedback is recorded 520 in order to assist in predicting future transactions. [0056] It will be apparent to those skilled in the art that, in the course of selection and construction of messages, the probability of success may be assessed differently with respect to different modes of operation, or different types of messages or advertisements. For example, automobile advertisements may be considered highly successful if the advertisements meet a 5% probability of success, while restaurant advertisements must meet a 30% probability of success. Additionally, if the user requests an advertisement, messages may be sent freely, highest probability first, for example, due to the overall high probability that the user desires the information. On the other hand, only messages meeting a minimum probability of success may be selected in an embodiment wherein a message is selected automatically, such as in accordance with a time, date, and location of the user. [0057] The search capabilities of the present invention may include an open request mode, wherein the user requests delivery of messages associated with a term, and with the profile of that user, rather than searching for a specific term. For example, a user might enter the term “food”, and the search might proceed to locate restaurants, in the area then-local to the user, having messages available. Additionally, for example, if a user were in the East end of a town, and selected the open request mode, and entered a blank search, all advertisements of interest to that profile, location, and time might be located. If multiple messages were located, the messages might be sent to the user in a priority order based upon the relative probabilities of success. [0058] It will be noted that assessing the location of the user in the present invention may be accomplished by a variety of methods, as will be apparent to those skilled in the art, such as, but not limited to, a global positioning system, geo-location using triangulation, such as with telephone towers, internet IP addresses, and/or landline telephone caller identifications. Similarly, assessing the time of user transactions and predictions may be accomplished in a variety of ways, as will be apparent to those of ordinary skill in the art, such as by a device clock in communication with a device monitor, an external system clock, internet time, or global position time. [0059] It will be apparent to those skilled in the art that various modifications and variations may be made in the apparatus and process of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modification and variations of this invention provided that those modifications and variations come within the scope of the appended claims and the equivalents thereof.

A system and method for providing a personalized advertisement for a good or service for display to a user is described. The system includes a communications device operated by the user; a virtual person database comprising information about the user; and a search engine useful for finding advertisements of interest to the user and generating personalized advertisements for display on the communications device.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to novel thermosetting resin compositions composed of isopropenyl phenol linear polymers and epoxy resins, and to the cured products thereof. 2. Description of the Prior Art Thermosetting resin compositions composed of high molecular compounds containing at least two epoxy groups in one molecule, i.e., epoxy resins, and phenolic compounds have been known, which find utility in the fields of paints, moldings and laminates. The thermosetting resin compositions composed of isopropenyl phenol linear polymers and epoxy resins and cured products thereof, however, have been entirely unknown. SUMMARY OF THE INVENTION An object of the present invention is to provide novel compositions which give, upon thermosetting, cured products with excellent heat resistance and chemical resistance, and also to provide such cured products. Another object of the invention is to provide novel compositions the curing speed of which is variable over an extremely broad range according to the intended use, and also the cured products thereof. The invention provides, accordingly, novel thermosetting resin compositions composed of isopropenyl phenol linear polymers and epoxy resins, and the cured products thereof. The isopropenyl phenol linear polymers to be used in this invention are the linear polymers of ortho- and/or meta- and/or para-isopropenyl phenol having the following formula (1) and/or (2) and/or (3): ##STR1## (in which m and n are zero or positive integers of 1-10,000). According to the invention, the isopropenyl phenol linear polymers may contain up to 20% by weight of the cyclic dimers of isopropenyl phenol of the formula (4): ##STR2## and the ring-substituted compounds of those illustrated by the formulae (1), (2), (3) and (4). As the epoxy resins to be blended with the isopropenyl phenol linear polymers, any of the compounds known as "epoxy resin" containing at least two epoxy groups in one molecule can be used, examples of such compounds including bisphenolic epoxy resins, halogenated bisphenolic epoxy resins, novolak type epoxy resins, polyphenolic epoxy resins, polyhydroxybenzene epoxy resins, polyglycolic epoxy resins, aromatic carboxylic acid epoxy resins, alicyclic epoxy resins, and nitrogen- or metal-containing epoxy resins. The epoxy equivalent of those epoxy resins are not particularly limited, but the suitable range is from 100 to 1,000. As the bisphenolic epoxy resins, for example, the reaction product of bisphenol A with epichlorohydrin may be named, which can be illustrated by the general formula (5): ##STR3## which suitably has the molecular weight of 300 to 10,000. Furthermore, this type of epoxy resins include those illustrated by the following formula (6) and (7). ##STR4## Examples of the halogenated bisphenolic epoxy resins are the compounds of the above formulae (5), (6) and (7) having halogen substituents on the aromatic rings. Examples of the novolak type epoxy resins include the reaction product of phenol-formaldehyde novolak with epichlorohydrin, which can be illustrated by the formula (8): ##STR5## As the polyglycolic epoxy resins, for example, those illustrated by the general formulae (9), (10), (11) and (12) may be named. (In the formulae (9), R stands for a hydrogen or an alkyl group.) ##STR6## As the alicyclic epoxy resins, for example, those illustrated by the general formula (13) through (18) may be used: ##STR7## Also as the polyphenolic epoxy resins, for example, the compounds of the general formulae (19) and (20) can be used: ##STR8## Examples of the useful polyhydroxybenzene epoxy resins are those covered by the formulae (21) and (22): ##STR9## As the epoxy resins of aromatic carboxylic acid type, for example, the compounds of the formulae (23) may be used: ##STR10## As the nitrogen-containing epoxy resins, for example, the compounds covered by formula (24) and (25) may be used: ##STR11## (in the formula (24), R stands for a hydrogen atom or methyl group; in the formula (25), R 1 and R 3 stand for hydrogen atoms or methyl groups, and R 2 denotes an isopropyl or methyl group). The compositions of the present invention are prepared by homogeneously mixing isopropenyl phenol linear polymers with epoxy resins, at various ratios according to the purpose. If the ratio between the number of hydroxyl groups of the isopropenyl phenol linear polymer and the number of epoxy groups of the epoxy resin in a composition (the ratio being hereinafter abbreviated as R, i.e., R=hydroxyl groups/epoxy groups) is too high, however, the crosslinking density becomes small. If R is too low, on the other hand, the composition gives a thermoplastic cured product. Thus in either case the improvements in physical properties of the cured products is hardly achieved. It is desirable, therefore, that the R of the composition should be within the range of 0.2 to 5, preferably from 0.5 to 2. The compositions of the present invention may take various forms, with the R's within the above-specified range. That is, the composition may be a liquid or solid, depending on the forms of the isopropenyl phenol linear polymer and epoxy resin employed as the starting materials. The composition may be made liquid, by adding thereto an organic solvent which can dissolve the isopropenyl phenol linear polymer and epoxy resin but does not react therewith, such as a ketone, e.g., acetone or methyl ethyl ketone; an ester, e.g., methyl acetate or ethyl acetate; or a vinyl monomer such as styrene or methyl methacrylate. Furthermore, other additives such as a dyestuff, pigment, plasticizer, reinforcing material, filler and the like may also be blended into the composition. The curing of the compositions of this invention is effected by heating them at a temperature not lower than 100° C. for 30 minutes to 10 hours. The heating at 150°-250° C. is preferred, for shortening the curing time and obtaining the characteristic properties of the cured products. While the compositions of this invention are curable by heating alone, without the concurrent use of a curing accelerator, the curing may be promoted by prior adding to the composition of a curing accelerator conventionally used for curing epoxide-phenolic compositions, (for example, tertiary amines or the compounds containing Lewis acid), DESCRIPTION OF THE PREFERRED EMBODIMENTS Of the isopropenyl phenol linear polymers useful for the present invention, the linear dimers of the general formulae (1) and (2) in which m equals zero and which have hydroxyl groups at their para-positions, can be obtained by heating a mixture of p-isopropenyl phenol oligomers containing no more than 10% by weight of phenol to 80°-150° C. The starting mixture in turn is obtained by distilling the phenol off from the reaction product of base-catalized cleavage reaction of bisphenol A, which is composed of phenol, p-isopropenyl phenol and the oligomers thereof (Japanese Patent Publication No. 10869/77). The linear dimers may also be obtained by heating and dimerizing isopropenyl phenol monomer (Japanese Patent Application Disclosure No. 63360/78). The compounds of the general formulae (1), (2) and (3) in which n≧1 can be obtained by polymerizing isopropenyl phenol monomer and/or the linear dimer thereof, in the presence of an acid catalyst. Particularly the linear polymers of p-isopropenyl phenol can be produced by the concurrent use of the cationic polymerization catalysts well known and used per se and solvents. As such a catalyst, tin tetrachloride or boron trifluoride-ether complex show an excellent effect, and as the solvent acetonitrile gives favorable results. A linear polymer of p-isopropenyl phenol having an average molecular weight of 5,000-100,000 can be obtained from such a polymerization system, at a temperature of -50°-0° C., for the polymerization period of 15-60 minutes. Or, when an acetate of p-isopropenyl phenol is polymerized in methylene chloride, in the presence of BF 3 .OEt 2 catalyst, at -20° C. for 60 minutes, and then the product is hydrolyzed, poly(p-isopropenyl phenol) having an average molecular weight of 10,000 can be obtained. Hereinafter a few of the more specific examples of the polymer preparation will be given. Preparation of p-isopropenyl phenol linear polymer: 1 17.1 grams of p-isopropenyl phenol were dissolved in 200 ml of acetonitrile which had been dehydrated with molecular sieve 4A, and the solution was cooled to -25° C. Then 0.5 mol% of SnCl 4 was added thereto with a syringe, to cause the polymerization for 60 minutes. Thereafter the reaction mixture was introduced into a large quantity of water, and the resulting precipitate was recovered and dried. The dry product weighed 13.3 g. Its molecular weight was determined by GPC. The average molecular weight was 56,000, and the maximum molecular weight was 300,000. Preparation of p-isopropenyl phenol linear polymer: 2 50 grams of an acetate of p-isopropenyl phenol were dissolved in 100 ml of methylene chloride, and the solution was cooled to -50° C. A 40% ether solution of BF 3 .OEt 2 was added thereto with a syringe, to have a mole ratio of BF 3 .OEt 2 to p-isopropenyl phenol monomer of 0.5%. After 60 minutes, the reaction mixture was neutralized with a 10% aqueous ammonia. The methylene chloride was removed, and the remaining product was dissolved in acetone and inserted into water. Thus a white polymer was obtained, which was hydrolized with a 10% aqueous solution of sodium hydroxide at 90° C., for 24 hours, followed by a neutralization with 10% HCl. The white polymer thereupon precipitated was collected by filtration, and weighed 30.2 g. The GPC analysis of the polymer showed that its average molecular weight was 14,000, and the maximum molecular weight 200,000. As aforesaid, the isopropenyl phenol linear polymers to be employed in the present invention are those of the general formulae (1), (2) and (3) in which m or n ranges form 0 to 10,000, the oligomers of said formulae in which m≦8 and n≦7 being particularly preferred. Another unexpected advantageous feature of the subject compositions is that their curing conditions allow a wide range of selection. For example, the compositions of this invention are curable by heating at temperatures not lower than 100° C. for 30 minutes to 10 hours as aforesaid, but the curing time can be drastically shortened by the concurrent use of an accelerator. The effect of the curing accelerators is surprisingly great, and could not be predicted from the action of same accelerators in the curing of bisphenol A having a chemical structure analogous to that of the compounds (1) and/or (2) of the present invention. This novel discovery enables the utilization of subject compositions in novel fields of applications. Specific examples of the curing accelerators useful for shortening the curing time of the subject compositions include tertiary amines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, N,N-dimethylbenzylamine and N,N-dimethylaniline; nitrogen-containing heterocyclic compounds such as pyridine and imidazole; complexes of boron trifluoride with aniline, ethylamine, diethylamine, triethylamine, pyridine and imidazole; and salts of Lewis acid with amine. Obviously, primary and secondary amines may also be used. By the concurrent use of such curing accelerators, the curing time can be shortened from one-third to one-tenth. The compositions of this invention have a wide variety of applications such as coatings, moldings, laminates and other composite materials, and can be used in various forms. For example, a composition of this invention can be dissolved in a suitable solvent and coated on a substrate, dried and heated, to form a smooth coating film on said substrate. An equivalent effect can be achieved by compressing a powdery composition of this invention, placing it on a substrate and heating the same. Also upon melting the composition at a temperature that will not cure it, pouring the molten composition into a mold and heating it at curing temperatures, cast articles can be obtained. Composite materials can also be prepared from the compositions of this invention. For instance, a composition of this invention may be melted at temperatures below its curing point, or dissolved in an organic solvent, and caused to impregnate into a reinforcing material such as organic fibers, graphite fiber, asbestos, glass fiber, woven or non-woven glass fabric, or slag wool; and when it is used in solution, the organic solvent employed is evaporated to provide impregnated products such as bulk molding compound, sheet molding compound, prepreg, and the like, which show no tackiness at room temperature excellent storage stability and are easy to handle. The impregnated product is then placed into a mold by a suitable method, and cured by heating under elevated pressure. Thus a composite material strengthened by the reinforcing material is obtained. Furthermore, copper-clad laminate sheets for printed circuits can be obtained by superposing a plurality of prepregs, and heating and pressurizing the same together with copper foil. The heating temperature in that case may be that for curing the composition of this invention, but preferably the heating is effected at 150°-200° C. for 1-2 hours under an elevated pressure, and then at 180°-250° C. for 2-4 hours for post-curing. It should be obvious that inorganic fillers or the like may be concurrently used in the preparation of composite materials, similarly to the conventional reinforced plastics. In the compositions of the present invention, the olefinic double bonds in the compounds of the general formulae (1), (2) and (3), particularly the oligomers in which n≦8, can be still more effectively utilized for certain specific uses. That is, a curing reaction using the olefinic double bond or a crosslinking reaction by copolymerization with an olefinic compound or compounds can be induced, simultaneously with the curing of epoxy resins with the phenolic hydroxyl groups. Such compositions according to this invention can be prepared by homogeneously mixing the isopropenyl phenol linear polymer, particularly the linear oligomers, an epoxy resin, and a compound which releases free radical or acid upon heating, photo radiation or radiant ray radiation. The compounds which release free radicals or acids are the known radical polymerization initiators and the salts or complexes of Lewis acid. More specifically, examples of the compounds which release free radicals include azobis-isobutyronitrile, azobis-cyclohexanenitrile, benzoyl peroxide, ditertiary butyl peroxide and tertiary butylhydroperoxide. As the compounds which release acids, boron trifluoride-ethylamine complex, boron trifluoride-di-secondary-butylamine complex, boron trifluoride-diethylamine complex, boron trifluoride-N,N-dimethylaniline complex, boron trifluoride-pyridine complex, boron trifluoride-imidazole complex, boron trifluoride-piperazine complex, imidazoleacetic acid complex, aniline-boron trifluoride complex, triethylamine-boron trifluoride complex, magnesium hydroxide, and zinc chloride may be named. It is possible to use more than one of the above compounds concurrently. It should be understood that the scope of this invention is not limited to the above-named compounds. It is preferred, furthermore, that of the said compounds, those which release acids upon heating, photo radiation or radiant ray radiation, be blended. Again of the compounds which release acid, boron trifluoride-amine complex acts also as a curing accelerator in the curing of the epoxy resin by the phenolic hydroxyl group as aforesaid. In one embodiment of the subject compositions, first an isopropenyl phenol linear polymer and an epoxy resin are mixed under heating to cause a partial reaction between the two compounds, and thereafter, for example, boron trifluoride-amine complex is homogeneously mixed into the resulting mixture. When the aforesaid R of the subject composition is too small, it gives a thermoplastic cured product, and the characteristic features of this invention are not obtained. Similarly, neither an excessively high R gives favourable results. The composition of this invention, therefore, desirably has an R within the range of 0.2-5, and contains 0.1-10% by weight, preferably 1-5% by weight, of a compound or compounds which generate free radicals or acids upon heating, photo radiation or radiant ray radiation. The curing mechanism of the subject compositions has not yet been entirely clarified, but presumably it is because the active double bonds in the aliphatic chains in the compounds of the general formulae (1), (2) and (3) are readily converted to carbonium cations to participate in the splitting of epoxy rings. In fact, it has been discovered that an infrared absorption spectrum of the product cured by boron trifluoride-amine complex shows that its double bond content is drastically reduced. Hereinafter the invention will be more fully explained with reference to the working examples, in which the parts are by weight. EXAMPLE 1 Forty (40) parts of a linear polymer of p-isopropenyl phenol (average molecular weight, 2500) and 60 parts of Epikote 828 (a bisphenolic epoxy resin manufactured by Shell International Chemicals, Corp., having an epoxy equivalent of 190) were mixed under heating at 60°-80° C., to provide a composition. The R of said compositions was 0.93. The composition was poured into a silicon rubber mold and heated at 150° C. for an hour, and at 180° C. for two additional hours. Thus a light reddish brown and transparent cured product was obtained. EXAMPLE 2 To 40 parts of one linear polymer of p-isopropenyl phenol (average molecular weight, 2,500), 90 parts of Epikote 828 and a part of a boron trifluoride-piperidine complex dissolved in a minor amount of acetone were added, and mixed under heating at 60°-80° C. The resulting composition had an R of 0.62. The composition was poured into a silicon rubber mold and heated at 150° C. for 30 minutes, and at 180° C. for an hour, to give a cured product similar to that obtained in Example 1. EXAMPLE 3 Forty (40) parts of a linear trimer of p-isopropenyl phenol (99% purity) and 80 parts of Epikote 828 were mixed under agitation at 130°-150° C. for approximately an hour. Thus a homogeneous and transparent composition was obtained, which had an R of 0.70 and an epoxy equivalent of 280. When 50 parts of this composition was homogeneously mixed with a part of an imidazole-acetic acid complex and heated to 150° C., the mixture was cured in 3-5 minutes. When the above complex was replaced by 0.2 parts of triethylamine and heated at 150° C., the mixture was cured in 1-3 minutes. EXAMPLE 4 A mixture of p-isopropenyl phenol and its oligomer (composed of 72% of p-isopropenyl phenol linear dimer, 2.5% of its monomer, 4.3% of its linear trimer, 2.1% of its linear tetramer, 0.9% of its linear pentamer, 1.5% of its linear hexamer and higher order oligomers and 16.7% of other components) was used as the polymer component, the (percentages being by weight, which is commercially available as "Parmanol 200" (manufactured by Mitsui Toatsu Chemicals, Inc., Japan). Said Parmanol 200 and Epikote 828 were mixed at 100° C. at various ratios, making compositions having the R of, respectively, 0.5, 1.0 and 1.5. To each of the compositions dicyandiamide was added in an amount of 5% by weight based upon the amount of Epikote 828. Their gelation time on a hot plate kept 160° C. was measured (shown in Table 1). COMPARATIVE EXAMPLE 1 Example 4 was repeated except that Parmanol 200 was replaced by bisphenol A, and the gelation time of the resulting compositions was measured (also shown in Table 1). TABLE 1__________________________________________________________________________Variation in Gelation Time Pharmanol Bisphenol Epikote 828 Dicyandiamide Gelation 200 (parts) A (parts) (parts) R (parts) time (min.)__________________________________________________________________________ -- -- 100 -- 5 75 42 -- 100 0.5 5 15Example 4 84 -- 100 1.0 5 8 125 -- 100 1.5 5 5 -- 30 100 0.5 5 25Comparative -- 60 100 1.0 5 14Example 1 -- 90 100 1.5 5 10__________________________________________________________________________ As it can be seen from Table 1, the time required for curing is markedly shortened with the compositions of this invention, compared with the results of Comparative Example 1. EXAMPLE 5 A linear polymer of p-isopropenyl phenol having an average molecular weight of 2500 (A), p-isopropenyl phenol linear trimer (B), Parmanol 200 (C) and bisphenol A (D) were each mixed with Epikote 828 at such ratios as would make the R of the composition 1.0. Using 1% by weight of boron trifluoride-piperidine complex, the compositions were cured in the same manner as in Example 2. Test pieces were sampled from the thus obtained cured products, and their HDT (Heat Distortion Temperature, see JIS K-7207) was measured. The results were as in Table 2, from which it can be understood that the compositions according to this invention (A, B and C) show considerably improved heat resistance, compared with the comparative (D). TABLE 2______________________________________HDT of Cured ProductsCuring Agents Epikote 828 BF.sub.3 Piperidine HDT(parts) (parts) R (part) (°C.)______________________________________A 36 50 1.0 0.9 185B 36 50 1.0 0.9 145C 42 50 1.0 0.9 135D 30 50 1.0 0.8 120______________________________________ EXAMPLE 6 One-hundred (100) parts of p-isopropenyl phenol linear polymer (average molecular weight, 4,500), 400 parts of Epikote 1004 (a bisphenolic epoxy resin manufactured by Shell International Chemicals Corp., having an epoxy equivalent of 940), and 110 parts of Epikote 828 were dissolved in acetone to form a 50% solution (liquid A). Separately, 20 parts of Parmanol 200 and 3 parts of boron trifluoride-piperidine complex were dissolved in acetone to form a 60% solution (liquid B). A glass cloth (a satin weave microglass ES-21NH, manufactured by Nihon Glass Co., Japan) was immersed in the liquid B, squeezed to an approximately 60-70% pick-up, and air-dried. The same cloth was then immersed in the liquid A, squeezed to approximately 100-120% pick-up, air-dried, further dried at 60° C. for 10 minutes and at 80° C. for 5 minutes, to provide a prepreg. Ten sheets of this prepreg cloth were laid one over the other, and pressed under normal pressure at 180° C. for 30 minutes and further under a pressure of 20 kg/cm 2 for 30 minutes. The hot-pressed prepregs were post-cured for 3 hours at 180° C., to provide a laminate (laminate I). Using a 50:50 (by weight) mixture of the liquids A and B (liquid C) and an identical glass cloth, a laminate was obtained by procedures identical with the above-described, except that the liquid pick-up was made 140-160% (laminate II). Sample pieces were cut from the laminate, and their strength retention after a heat-treatment was measured (shown in Table 3). TABLE 3______________________________________Bending Strength Rentention Bending Strength* Bending Modulus*Laminate kg/mm.sup.2 % kg/mm.sup.2 --______________________________________I Normal state 40.0 100 1720 100 200° C./100 hrs. Heat- treatment 36.4 91 1280 75II Normal state 39.3 100 1700 100 200° C./100 hrs. Heat- treatment 35.0 89 1240 73______________________________________ *Both properties were measured in accordance with JIS K6911. EXAMPLE 7 One-hundred (100) parts of the composition prepared and 3 and 5 parts of boron trifluoride-piperidine complex were used as a 50% acetone solution, which was applied onto a zinc phosphate-treated steel plate, dried at room temperature and baked at 150° C. for 15 minutes, to provide a coated film. The thus obtained coated plate was divided and either immersed in methyl ethyl ketone for 24 hours, or left in methyl ethyl ketone under reflux for 3 hours, to evaluate the curing degree of the coated film. In both cases the curing degree of the coated film was satisfactory. The pencil hardness test (JIS K-5400) of the film resulted in H˜HB, and the checkers test, 96/100. Incidentally, the checkers test was performed as follows; An area of 1 cm 2 on the cured, coated film surface was cut into one-hundred, 1 mm 2 -wide checkers, and extruded from the reverse side with an Erichsen tester. A Cellotape (One-side tacky tape manufactured by Nichiban Co., Japan) was carefully applied to the checkers with hands, and the cellotape was then peeled off. The numerator in the test result is the number of checkers remaining after the cellotape was removed, as they could not be pulled off with said tape. EXAMPLE 8 Epikote 828 was mixed with linear polymers of p-isopropenyl phenol having various molecular weights, each at such a ratio as would make the R equal to 1.0, under by heating at 100° C. To each of the mixtures 5% by weight based on the Epikote 828 of an imidazole-acetic acid complex was added, and the compositions were hot-cured at 180° C. for 3 hours. The HDT's of the obtained cured products were as shown in Table 4. TABLE 4______________________________________HDT of Cured Product Molecular Weight of p-Isopropenyl HDTNo. Phenol Polymer R (°C.)______________________________________1 268 1.0 1362 402 1.0 1423 1,050 1.1 1594 2,500 1.1 1835 4,500 1.0 1826 14,000 1.0 1907 56,000 1.0 189______________________________________ EXAMPLES 9-12 A linear trimer of p-isopropenyl phenol (molecular weight 402) was mixed at 100° C. with various epoxy resins as specified in Table 5, each at such a ratio as would make the R equal to 1.0. Further to each of the mixtures, one part of an imidazole-acetic acid complex was added per 100 parts of the employed epoxy resin as the curing accelerator, and was homogeneously mixed. By heating the compositions at 170° C. for 2 hours under elevated pressure, cured products were obtained. TABLE 5______________________________________Blend Ration in The Compositions Amount of p-Isopropenyl Epoxy Equi- Phenol TrimerExample valent of (parts/100 partsNo. Type of Epoxy Resin Resin) of epoxy resin)______________________________________ 9 Novolak type.sup.(Note 1) 180 7510 Halogenated bisphenol 360 37 type.sup.(Note 2)11 Alicyclic type.sup.(Note 3) 138 9612 Polyglycol type.sup.(Note 4) 260 50______________________________________ .sup.(Note 1) The resin having the structure of formula (8), is the reaction product of a phenolformaldehyde novolak of an average molecular weight approx. 700, with epichlorohydrin. .sup.(Note 2) ##STR12## .sup.(Note 3) Tradename: CX221, a product of Chisso Co., Japan ##STR13## .sup.(Note 4) ##STR14## ##STR15##

The compositions composed by blending isopropenyl phenol linear polymers with epoxy resins containing at least two epoxy groups in one molecule, give cured products with excellent heat resistance and chemical resistance. With these compositions the curing speed is variable over an extremely broad range depending on the intended use, by optionally employing an accelerator.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a Non-provisional application claiming priority to U.S. Provisional Application Ser. No. 60/580,863, entitled, “Collapsible Folding Cooler,” by John Maldonado, filed Jun. 17, 2004, hereby incorporated by reference in its entirety herein. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates generally to the field of coolers and, more specifically, to a cooler that can be folded to facilitate storage. More particularly, the present invention relates to a softside cooler that can hold items while in an expanded state, but that can be collapsed when not in use to require less storage space. [0004] Softside coolers typically comprise coolers made of fabric providing thermal insulation for a cavity that may hold food and/or beverages. Softside coolers tend to be popular because they are often collapsible and may be more fashionable than a hardside cooler as a softside cooler may contain pockets or allow that attachment of accessories or gadgets. [0005] 2. Description of the Related Art [0006] Generally, insulated containers, sometimes referred to as coolers and/or ice chests, have been used for many years to transport food and beverages between locations while keeping the contents at a desired temperature. Typically, the insulated coolers are used to carry cold items such as soda, beer, sandwiches, ice cream, fish, meat, and so on. Alternatively, the insulated coolers can be used to transport hot items such as casseroles, lasagna, vegetables, and so on. [0007] Coolers may typically be categorized as hardsided or softsided. Hardsided coolers include coolers having an outside body made from hard plastic, such as blow molded or injection molded plastics. These hardsided coolers offer protection for the contents therein; however, the use of hard plastics hampers the ability of the hardsided coolers from having any external storage. Further, hardsided coolers maintain their shape, whether or not the coolers are in use. This has resulted in the need for excess storage space, as the hard coolers occupied their full volume even when not in use. [0008] Various attempts have been made to address this storage space issue. U.S. Pat. No. 6,736,309 B1 (issued May 18, 2004) describes a quick erecting, disposable cooler that is supplied as a flat blank of corrugated material. U.S. Pat. No. 5,853,121 (issued Dec. 29, 1998) describes a foldable laminated paperboard chest for transporting and storing food products, and a one-piece laminated paperboard blank from which such the chest is constructed. While these products can be stored flat, they are not easily reusable. Additionally, these products do not provide any external storage or versatility of the internal cavity. [0009] In contrast to hardside coolers, softside coolers typically comprise coolers made of a pliable material, such as fabric, and may include thermal insulation between the pliable material and the contents contained in the inside cavity, such as food and/or beverages. Softside coolers tend to be popular because they are collapsible and may contain external storage, such as pockets, for accessories. [0010] Although softside coolers may be collapsible, often the coolers do not stay in a compact, collapsed state due to the insulated fabric used. Thus, to decrease the volume of the collapsed cooler and maintain the minimum required storage space often an additional object, such as a heavy box, must be placed on top of the softside cooler. While this may be acceptable while storing the cooler in a semi-permanent place such as a garage, it would be inconvenient to bring such an object while traveling or on a family outing. [0011] An example of a collapsible cooler utilizing a hook and loop attachment mechanism (i.e. a fastening mechanism offered under the brand name VELCRO), is shown in the final figures of this disclosure, FIGS. 8 A-C. A strap “S” is adapted to secure the cooler in the collapsed state via hook “H” and loop “L” fasteners. As shown in FIG. 8B , a portion of the hook and loop mechanism is secured to the cooler (in this case the hook portion “H”). When expanded, the hook portion of the fastening mechanism remains visible and may be considered unsightly to some. Further, the hook and loop feature provides mono-functionality: to secure the cooler in the collapsed state. It would be advantageous to provide a fastening means which is esthetically pleasing, and further provides dual functionality of securing an object, such as a newspaper or towel, to the cooler when expanded. [0012] In light of the foregoing, it would be desirable to provide a cooler that is collapsible, provides external storage, has a versatile internal cavity, effectively maintain the temperature of their contents, and includes a mechanism to maintain the compressed volume of the cooler for ease of storage until the cooler is needed again. Further, it would be desirable to provide a collapsible cooler where the mechanism to maintain the cooler in a compressed state could also provide utility while the cooler was in an expanded state. Finally, it would be advantageous if the same mechanism that maintained the cooler in the compressed state could have a dual function of supporting accessories, such a beach towels, for example, onto the cooler in the expanded state. SUMMARY OF THE INVENTION [0013] The insulated cooler described herein is a collapsible insulated cooler that attempts to overcome some of the disadvantages described above. In some embodiments, the cooler may be comprised of fabric and an insulating material such as closed cell foam. The cooler may have a securing mechanism for maintaining the cooler in its compressed, folded state when not in use. The cooler may include a waterproof liner to prevent leakage, as well as other convenience features such as handles, shoulder straps, pockets, and so on. [0014] In some embodiments, the cooler comprises a bottom, a top, at least one side made of substantially pliable material, and means for securing the cooler in a collapsed state. In some embodiments, the means for securing the cooler in a collapsed state may comprise an elastic band or elastic shock cord. In an alternative embodiment, the means for securing the cooler in a collapsed state may comprise a strap with snaps or hook and eye closures. The means for securing the cooler may also be able to secure an item, such as a towel, to the exterior of the cooler. In some embodiments, the top may be reversibly attachable to the cooler by a zipper or elastic fitting. In one embodiment, the cooler may include a waterproof cavity. Additionally, the cooler may include an internal divider or internal pocket. In an alternative embodiment, at least of the one of the top, side, or bottom of the cooler may comprise a substantially rigid material. In one embodiment, the cooler contains a cylindrical cavity defined by a top, bottom, and at least one side. [0015] In one embodiment, the cooler may include both an expanded and compressed state and comprise a rectangular cross-section having four sides, a top, and a bottom. Further, the four sides, top, and bottom may comprise softside material and be collapsible. The cooler may include means for retaining the cooler in a compressed state such as an elastic strap or shock cord attachable to the top. In an alternative embodiment, the elastic strap or shock cord may secure an item to the exterior of the cooler while the cooler is in an expanded state. In another embodiment, the cooler may include an interior ice pack packet. The cooler may also include a heat sealed liner. [0016] In another embodiment, the cooler may comprise a bottom, at least one side, and top where one of the bottom, at least one side, and top comprises a substantially pliable material such that the cooler may be collapsed from an expanded state. The cooler may include an elastomeric band or strap to retain the cooler while in the collapsed state. In some embodiments, the elastomeric band or strap has a dual function: the elastomeric band or strap may also be utilized to selectively secure an object, such as a beach towel, onto the cooler, while the cooler is in the expanded state. DESCRIPTION OF THE FIGURES [0017] The following figures form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these figures in combination with the detailed description of specific embodiments presented herein. [0018] FIG. 1A shows a perspective view of an embodiment of the present disclosure of a cooler 1 having a rectangular cross section in an expanded state. [0019] FIG. 1B shows a perspective view of the embodiment of FIG. 1A of the present disclosure of the cooler in a compressed state. [0020] FIG. 2 shows a side view of the embodiment of FIG. 1B of the present disclosure. [0021] FIG. 3A shows a front view of an embodiment of the present disclosure of a cooler 1 in a compressed state and a securing mechanism 5 in an unfastened position. [0022] FIG. 3B shows a front view of the embodiment of FIG. 3A of the present disclosure of the cooler in a compressed state and the securing mechanism retaining the cooler in the compressed state. [0023] FIG. 4A shows a perspective view of an embodiment of the present disclosure of a cooler 1 having one side 3 with the cooler 1 in an expanded state. [0024] FIG. 4B shows a perspective view of the embodiment of FIG. 4A of the present disclosure in a collapsed state. [0025] FIG. 5A shows a perspective view of an embodiment of the present disclosure of a cooler 1 in an expanded state with a securing mechanism 5 attached to a retention device 12 . [0026] FIG. 5B shows a perspective view of the embodiment of FIG. 5B of the present disclosure with the securing mechanism in an unfastened position. [0027] FIG. 6A shows a rear view of an embodiment of the present disclosure of a cooler 1 in an expanded state. [0028] FIG. 6B shows a rear view of the embodiment of FIG. 6A of the present disclosure having a securing mechanism 5 not attached to a retention device 12 . [0029] FIG. 7 shows an embodiment of the present disclosure showing the dual functionality of a securing mechanism [0030] FIG. 8 shows a prior art collapsible cooler, utilizing a hook and loop system. [0031] While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims. DETAILED DESCRIPTION OF THE INVENTION [0032] Illustrative embodiments of the invention are described below as they might be employed in the use of designs for collapsible softside coolers. As used herein, cooler may be utilized interchangeably with cooler, ice chest, insulated container, and the like, and each term (cooler, ice chest, insulated container) is to be given its ordinary meaning. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. [0033] Further aspects and advantages of the various embodiments of the invention will become apparent from consideration of the following description and drawings. [0034] While articles are described in terms of “comprising” various components (interpreted as meaning “including, but not limited to”), the articles can also “consist essentiall of” or “consist of” the various components and steps, such terminology should be interpreted as defining essentially closed-member groups. [0035] As shown in FIG. 1A , the cooler 1 may comprise a bottom 2 , at least one side 3 , a top 4 , and a securing mechanism 5 . The bottom 2 , at least one side 3 , and top 4 define an interior space 6 . One or more of the bottom 2 , at least one side 3 , and top 4 can be made of an insulated material. The bottom 2 , at least one side 3 , and top 4 may all be made of an insulated material. The bottom 2 , at least one side 3 , and top 4 can independently be made of a solid, hard material (“hard sided”) or of a flexible material (“soft sided”). Various combinations of materials can be used as well. For example, the bottom 2 and top 4 can be hard sided, while the at least one side 3 can be soft sided. Example materials include plastic, polyvinylchloride (“PVC”), nylon, fabric, foam, and so on. [0036] As shown in FIG. 1A , the exterior of the cooler 1 may include a handle 7 , shoulder strap 9 , and/or pocket 10 . The top 4 of the cooler 1 may include a retention device 12 , connectable to a securing mechanism 5 . The retention device 12 may comprise a knob, or hook, could be used to connect to the securing mechanism 5 . In some embodiments, the retention device 12 may cause the securing mechanism to remain taut when not in use to retain the cooler 1 in a collapsed state. [0037] As shown in FIG. 1B , cooler 1 may be compressed by bringing the top 4 together with at least one side 3 causing a bottom 2 and any remaining sides 3 to collapse. The cooler 1 may include a securing mechanism 5 to retain the cooler 1 in its compressed state. The securing mechanism 5 may be a shock cord or elastic cord attachable to the top 4 as shown in FIG. 3A . [0038] FIG. 2 shows the side view of the cooler 1 in a compressed state. The bottom 2 and three sides have been collapsed allowing the top 4 and one side 3 to come together. The volume of inner cavity 6 (not shown) is decreased as illustrated in FIGS. 1B and 2 in comparison to FIG. 1A . The cooler 1 may include a retention mechanism 5 to maintain the cooler 1 in a compressed state. [0039] FIGS. 3A and 3B show the front view of one embodiment of a cooler 1 in a collapsed state. As shown in FIG. 3B , a securing mechanism 5 may be attached to the top 4 of the cooler 1 and be extended around cooler 1 to maintain the cooler 1 in a collapsed state. In FIG. 3B the securing mechanism 5 is shown in an unfastened position. [0040] One embodiment of the present disclosure having one side is generally round (cylindrical) or oval in cross section as shown in FIGS. 4A-4B . The cooler 1 may include a securing mechanism 5 that is connected to a retention mechanism 12 while the cooler 1 is expanded. In some embodiments, the cooler 1 may have only one side 3 that may include a pocket 10 , handle 7 , and/or shoulder strap 9 (not pictured). The cooler 1 may be compressed by folding in the one side 3 while bringing the top 4 and the bottom 2 together. In the embodiment shown in FIG. 4A , the cooler 1 may take a circular shape when in the collapsed state as shown in FIG. 4B and the securing mechanism 5 may be used to maintain the cooler 1 in the collapsed state. [0041] As would be apparent to one skilled in the art, the number of side of the cooler 1 can generally be any number, such as 1 , 3 , 4 , 5 , 6 , and so on. As shown in FIGS. 4A-4B and discussed above, embodiments having 1 side generally would have a circular or oval cross section. Alternative embodiments having three sides can be triangular in cross section (such as right triangular, isosceles, scalene). Other embodiments having four sides can have various cross sections such as square, rectangular, trapezoid, or other shapes. [0042] In one embodiment, the top 4 of cooler 1 can be reversibly attached to the top edge(s) of the one or more sides 3 . The reversible attachment allows the top 4 to be quickly and easily opened to allow access to the interior space 6 of the cooler where various items can be stored. The reversible attachment can generally be any type of reversible attachment such as a zipper or an elastic fitting. FIGS. 5A and 5B show an embodiment of the present disclosure wherein a cooler 1 has a top 4 reversibly attached to the cooler 1 by a zipper 15 . [0043] FIGS. 6A and 6B show a rear view of an embodiment of a cooler 1 that has no pockets or handles on the back side 3 of cooler 1 . In some embodiments, cooler 1 may include a side slip pocket 11 , handle 7 , and/or should strap 9 on a side of the cooler. [0044] In each embodiment a cooler 1 can be collapsed to occupy a smaller overall volume than when it is in its expanded state. The expanded state is used when transporting contents such as food or beverages. The collapsed state can be used when the cooler is not in use in order to conserve storage space. One or more of the sides or lid can be folded or otherwise manipulated to collapse the cooler. For example, in one embodiment a square or rectangular cooler can be collapsed by bringing the leading edges of the bottom and the top towards each other, collapsing the front and two sides. The collapsed state in this example would be a roughly flat square or rectangle. The securing mechanism 5 could be used to hold the cooler 1 in its collapsed state. In an alternative example, a cooler 1 having one side 3 and a circular cross section could be collapsed by bringing the bottom 2 and the top 4 together, with the side 3 collapsing between them. The collapsed state in this example would be a roughly flat circle. Again, the securing mechanism 5 could be used to hold the cooler 1 in its collapsed state. [0045] The volume of the expanded state can generally be any volume. Larger volumes are preferred when the user needs to carry large quantities of materials, while smaller volumes are preferred when the user needs to carry smaller quantities of materials. Coolers are frequently described in terms of their ability to hold a particular number of beverage cans. For example, a cooler may be able to hold 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, or more beverage cans. A typical soda can is a cylinder about 5 inches in height by 2.5 inches in diameter (12.7 cm in height by 6.35 cm in diameter). [0046] The securing mechanism 5 can generally be any securing mechanism effective to hold the cooler in its collapsed state. In some embodiments, as described with respect to FIG. 8 , the securing mechanism 5 provides dual functionality or utility, by providing a method of securing an object to the cooler in the expanded state. The securing mechanism 5 is preferably easily released in order to facilitate conversion of the cooler from the collapsed state to the expanded state. Examples of securing mechanisms include elastic bands, elastic shock cords (“bungee cords”), straps with snap closure mechanisms, straps with hook and eye closures, and so on. The securing mechanism 5 preferable does not interfere with the opening and closing of the top 4 while the cooler is being used in its expanded state. The securing mechanism 5 can also provide additional functionality while the cooler is in its expanded state. For example, an elastic shock cord could be used to hold towels, napkins, cups, or other items against the cooler 1 as a form of external storage. [0047] Referring to FIG. 7 , the cooler 1 is shown in the expanded state. An object “O” is shown secured to the top, in this example, of the cooler 1 . Of course, the object “O” could be a towel as shown, or a newspaper, umbrella, or any other type object the user may want to carry along with the cooler 1 . The securing mechanism 5 is shown sandwiching the object O to the top of the cooler now selectively secured to the top 4 of the cooler 1 by being stretched such that an end connects to retention device 12 . Of course, as described above, the retention device 12 could be placed elsewhere such that the object O may be sandwiched against a side or bottom of the cooler or generally anywhere against the cooler 1 . In this way, the securing mechanism 5 provides the cooler with dual utility or functionality. [0048] The cooler can further comprise various features such as a waterproof liner, one or more handles 7 , a shoulder strap 9 , one or more external pockets 10 , a side slip pocket 11 , one or more internal partitions, one or more internal pockets suitable for holding an ice pack, and so on. [0049] An alternative embodiment of the invention is a cooler comprising one wall that confers a spherical shape to the cooler when in its expanded form. The cooler can comprise a linear or curved opening through which the user can access the interior space 6 of the cooler. The opening can generally be any shape, such as a line, an arc, a “C” shape, and so on. The opening can be reversibly closed by use of a reversible attachment. The reversible attachment can generally be any type of reversible attachment such as a zipper or an elastic fitting. A user can collapse the cooler into a compact ball shape for storage. The cooler can comprise a securing mechanism 5 effective to hold the cooler in its collapsed state. The securing mechanism 5 can be any of those previously discussed. The cooler can further comprise any of the various features discussed in the previous paragraph. [0050] All of the articles disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the articles of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the articles described herein without departing from the concept and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the scope and concept of the invention. [0051] Although various embodiments have been shown and described herein, the invention is not so limited and will be understood to include all modifications and variations as would be apparent to one skilled in the art.

An insulated cooler that can be collapsed is disclosed. The cooler has a securing mechanism that allows a user to maintain the cooler in collapsed state indefinitely as well as reversibly convert the cooler from a collapsed state for storage to an expanded state for use. The securing mechanism may also allow a user to secure an item, such as a towel, to the exterior of the cooler while in the expanded state. The cooler can have a bottom, one or more sides, and a top. The shape of the coolers can be determined by selecting an appropriate number of side faces. The exterior of the cooler may have pockets, handles, or adjustable straps to increase the usefulness of the cooler. The securing mechanism may also be used to selectively secure an object or item onto the cooler when the cooler is in an expanded state.

CROSS REFERENCE TO PRIOR APPLICATIONS [0001] This application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2009/001393, filed on Feb. 27, 2009 and claims benefit to European Application No. EP 08003832.6, filed on Feb. 29, 2008. The International Application was published on Sep. 3, 2009 as WO 2009/106334 under PCT Article 21 (2). FIELD [0002] The invention relates to a component having an element made of elastomeric material, whereby the element is provided with a marking BACKGROUND [0003] Such components are known from European patent application EP 1 354 304 B1. There, a method is described for marking components by applying a counterfeit-proof marking. For this purpose, a label is provided with detectable particles that are distributed in a random pattern on the label. These particles are detected by an optical system and stored, and they can be once again unambiguously associated by repeatedly reading them out. By way of an example, this application describes the marking of a tire by means of a label. When it comes to machine elements, the aspects of security against counterfeiting and the traceability of the production are becoming more and more important since, for example, counterfeit inferior-quality seals can wear out prematurely or not even provide the requisite sealing effect, thereby causing tremendous damage. SUMMARY OF THE INVENTION [0004] An aspect of the present invention is based on applying a durable and counterfeit-proof marking on components with sealing materials. [0005] In an embodiment, the element, which is made of a sealing material, is provided with a marking that is incorporated as a topographic marking into the element. Sealing materials as set forth in the invention are polymer materials with elastomeric or elastic properties. Such materials are, for example, rubber-like materials, elastomers, thermoplastic elastomers, thermoplastic polyurethanes or polytetrafluoroethylene. The marking that is incorporated as a topographic marking deep into the material of the element contains data in encoded form about the product, the manufacturer as well as additional information. The encoding allows the marking and counterfeit-proof identification of the component as well as an unambiguous association of the component with a manufacturer and also, if applicable, information about production batches. Thus, the marking forms an authenticity feature. Preferably, the marking is incorporated into the element by means of laser processing, since the laser marking is applied directly onto the component, thereby marking the actual material itself. The laser treatment removes material down to a preselected depth. As a result, it is not possible to remove the marking from the component without damaging the component. Furthermore, it is advantageous that the laser marking takes place contact-free, so no deformation of the component can occur with a resultant distortion of the marking Moreover, the marking is applied after the production of the finished product. Therefore, production data such as the date of manufacture and the batch number as well as other quality features can be subsequently applied as additional information onto the component. The laser marking is applied onto the surface, as a result of which it is very easy to apply and to detect. Moreover, no foreign matter is introduced into the component that could be released and cause undesired effects. The marking can be read out with relatively simple optical means. Particularly when compared to electronic identifiers such as, for example, integrated memory modules, optical marking by means of a laser is cost-effective and thus also suitable for inexpensive mass-produced components. The optical marking is especially well-suited for marking curved, three-dimensional surfaces. Conceivable components that can be provided with the marking according to the invention are, for example, radial shaft seal rings, O-rings, X-rings, quad rings, rubber bellows, membranes, hydraulic seals, pneumatic seals and similar components. [0006] The marking can contain redundant information multiple times. Redundant means that the information is contained in the marking multiple times and in various forms. Thus, it is still possible to read out the marking, even if a large part of the marking has been destroyed, for example, by wear and tear. [0007] The marking can be incorporated into a functional surface of the element. Particularly with sealing components, it is necessary to mark their non-metal constituent. Seals are often made of a composite consisting of sealing material and metal, whereby original metal parts can be re-used for counterfeit products. Therefore, it is not advantageous to mark the metal part but rather it is advantageous to mark the element made of sealing material, which is responsible and much more critical for the sealing function and which is more prone to wear and tear and, under some circumstances, to also mark the functional surface. Surprisingly, it was found that the function of a seal is not impaired if a functional surface is provided with a laser marking that is applied onto the surface and that causes removal of material. In particular, it was found that components marked according to the invention also meet high hygienic requirements and that no impermissible bacterial growth occurs in the marking. Seals marked in this manner can especially be configured as sealing rings having various cross sections, as radial shaft seal rings, flat seals or valve stem seals. Especially in the case of O-rings and similar sealing elements, it is advantageous to be able to incorporate the marking into a functional surface, since it is not possible to determine ahead of time which surface section will be essential for the sealing function once the O-rings have been installed. [0008] The depth of the marking can be less than 100 μm, preferably less than 50 μm. Experiments have shown that markings can also be read whose depth is a mere 2 μm if the original surface roughness is below this value. However, in the case of such a slight depth, the legibility will diminish due to friction as the component ages, so that the markings of some components are no longer legible. As far as the legibility is concerned, it is advantageous when the depth of the marking is a deep as possible. However, some components of sealing components have developed a failure of the sealing function if the depth of the marking was more than 100 μm. An especially advantageous balance between the legibility and the sealing function is attained at a depth of less than 50 μm. If the sealing function is to meet stringent requirements or if unfavorable conditions prevail, then a depth of less than 25 μm is especially advantageous. It has also been found that the marking was still very legible, even after substantial swelling of the sealing material. [0009] A layer can be arranged over the marking This layer can be non-opaque, that is to say, transparent, or else opaque, that is to say non-transparent. In the case of an opaque layer, the layer has to be thinner than the depth of the marking so as to ensure the legibility. Advantageously, the thickness of the layer is maximally 50% of the depth of the marking With a transparent layer, which can be made, for instance, of clear lacquer, it is also possible to first apply the layer and to subsequently apply the marking through the layer by means of a laser treatment. In this process, the layer remains virtually unchanged. Here it is advantageous that the marking is protected by the layer against outside influences. Thus, the layer is especially well-suited for applications that call for a high level of security in terms of the marking. [0010] In an embodiment, the layer ( 5 ) is transparent. [0011] In an embodiment, the laser treatment is carried out through the layer ( 5 ). [0012] In an embodiment, the layer ( 5 ) is opaque. [0013] The component can be configured as a composite component made of metal and an elastomeric constituent. In addition to the above-mentioned seals, it is also particularly possible to provide a marking on shock absorbers, hydromounts, uncoupling elements and similar components. With these components, it is also advantageous for the elastomeric part to be provided with a marking instead of the metal part, since, in contrast to the elastomeric part, the metal part is easy to re-use. BRIEF DESCRIPTION OF THE DRAWINGS [0014] Several embodiments of the component according to the invention are explained in greater depth below with reference to the figures. The figures schematically show the following: [0015] FIG. 1 a marked O-ring; [0016] FIG. 2 a marked radial shaft seal ring. DETAILED DESCRIPTION [0017] FIG. 1 shows a component 1 , in this embodiment an O-ring, with an ring-shaped element 2 , the base, made of elastomeric material. The element 2 is provided with a topographic marking 3 that has been made in the element by means of a laser treatment. The marking 3 contains information in counterfeit-proof, encoded form about the product, the manufacturer, the production location, the date of manufacture and the material employed. In addition, information about material properties and limitations on use can be incorporated there. The information is applied onto the component 1 multiple times in different forms, as a result of which the information is contained in the marking 3 multiple times and redundantly. In this embodiment, the depth of the marking 3 is 24 μm. Since the entire circumference of an O-ring can be used as a functional surface 4 , the marking 3 is also made in the functional surface 4 of the element. The marking 3 is covered with a transparent layer 5 , whereby the marking 3 was applied into the element 2 through the layer 5 . [0018] FIG. 2 shows a component 1 , in this embodiment a radial shaft seal ring. The radial shaft seal ring consists of a carrier made of metal material and of a sealing lip that is applied onto the carrier. The sealing lip forms the element 2 which is made of elastomeric material. The sealing lip can also be made of other sealing materials such as, for example, PTFE. Therefore, the radial shaft seal ring is a component 1 configured as a composite part with metal. The topographic marking 3 is made in the elastomeric element 2 , that is to say, the sealing lip, by means of a laser and it has a depth of 30 μm. The marking 3 contains information in counterfeit-proof, encoded form about the product, the manufacturer, the production location, the date of manufacture and the material employed. Here, the information is applied onto the component 1 multiple times in different forms, as a result of which the information is contained in the marking 3 multiple times and redundantly. In this context, the marking 3 can be applied onto the element 2 in such a way that it can also be recognized and read out after being installed. Consequently, the component 1 can always be checked without being destroyed in the process. The marking is provided with an opaque layer 5 whose thickness is about 50% of the depth of the marking 3 .

A component includes at least one element made of a sealing material, wherein a topographic marking is incorporated into the at least one element,

[0001] This application claims priority to provisional application 61/095,682, filed Sep. 10, 2008. FIELD OF THE INVENTION [0002] This invention is a method of boosting the pressure in a compressed gas cylinder while dispensing from another with hydraulic pressurization equipment in order to maintain a constant cylinder pressure throughout the gas dispensing operation. BACKGROUND OF THE INVENTION [0003] Compressed natural gas (CNG) is any natural gas that has been processed and treated for transportation, in bottles or cylinders, at ambient temperature and at a pressure approaching the minimum compressibility factor. [0004] Natural gas is colorless, odorless, and lighter than air, and it easily dissipates into the atmosphere when it leaks. It burns with a flame that is almost invisible, and it has to be raised to a temperature above 620° C. in order to ignite. By way of comparison, it should be noted that alcohol ignites at 200° C. and gasoline at 300° C. For safety reasons, natural gas is odorized with sulfur for marketing purposes. [0005] Natural gas is an alternative to oil and therefore, it has great strategic importance, since it is a fossil fuel found in porous subsurface rock. It usually has low levels of pollutants, similar to nitrogen, carbon dioxide, water and sulfur compounds that remain in a gaseous state at atmospheric pressure and ambient temperature. Compressed natural gas is stored at a pressure of 220 bars or 3190 psi and is transported in trailers of varying volumetric capacity, depending on legislation and customer/project requirements. [0006] The principal advantage of using natural gas is the preservation of the environment. In addition to economic benefits, it is a non-polluting fuel and it burns cleanly, so its combustion products that are released into the atmosphere do not need to be treated. [0007] The great need to transport and store natural gas has contributed to increasing gas research around the world. Various methods have been proposed for storing and transporting compressed gases, such as natural gas, in pressurized vessels for overland transportation. The gas is typically stored and transported at high pressure and low temperature to maximize the amount of gas contained in each gas storage system. For example, compressed gas must be in a dense single-fluid state characterized as a very dense gas with no liquid. [0008] CNG is typically transported over land in tanker trucks or tank wagons. Tankers have storage containers such as pressurized metal vessels. These storage vessels have high burst strengths and withstand the ambient temperature at which CNG is stored. [0009] Storage vessels or cylinders are filled with compressed gas, typically using a compressor. A byproduct of the compression of the gas is heat, which ultimately raises the temperature of the gas in the cylinder. When a cylinder is filled to a specific pressure at a charging facility, for example 220 bar, that pressure will drop as the heat dissipates and the cylinder cools. When a series of cylinders reaches a dispensing location, the temperature of the cylinders has dropped, and as a result, the pressure of the cylinders has also dropped. Before gas can be dispensed from these cylinders, the gas pressure must be increased to the desired dispensing pressure, for example, 220 bar. [0010] A new technique is necessary in order to ensure minimal delay in charging a cylinder to a desired dispensing pressure once it arrives at a dispensing location. The following technique may solve one or more of these problems. The present technique exceeds the deficiencies described by providing hydraulic pressurization equipment that is capable of servicing the motor vehicles efficiently while maintaining a substantially constant desired pressure at all times. A system is utilized to boost the pressure in a cylinder while dispensing from another. SUMMARY OF THE INVENTION [0011] A fixed and/or stationary modular unit consists of a hydraulic fluid tank, a pressurization pump, and a compressed gas transportation system consisting of a set of cylinders. Each cylinder has two ports, a hydraulic fluid charging port and a gas dispensing port, with actuated valves positioned at each port. A valve is connected at the dispensing port of each cylinders with the valves at the dispensing ports of each cylinder also being connected to one another. [0012] Gas is dispensed from the dispensing port of the cylinder by opening the valve at the dispensing port. The dispensing activity is monitored until a specified idle period has been met. The valves at the dispensing ports of at least two of the cylinders are opened and compressed gas is bled from one cylinder to another cylinder or plurality of cylinders. A pressure sensor monitors the pressure of the cylinder that compressed gas is being bled from and indicates when the pressure inside the cylinder has dropped. The valve connected to the incoming hydraulic fluid line is opened and hydraulic fluid is pumped from the tank into the cylinder to maintain a substantially constant desired pressure within the cylinder. Compressed gas is bled from one cylinder to another cylinder or plurality of cylinders until the other cylinder or plurality of cylinders have reached the desired dispensing pressure. BRIEF DESCRIPTION OF THE DRAWINGS [0013] FIG. 1 is a schematic of a compressed gas filling system It illustrates the operation of the hydraulic pressurization equipment (HPU) connected to an over-the-road semi trailer. [0014] FIG. 2 is a flow chart of the operating steps of the system for pressurizing a compressed gas cylinder while dispensing from another. [0015] FIG. 3 is a schematic of an example of the system for pressurizing a compressed gas cylinder while dispensing from another. DETAILED DESCRIPTION OF THE INVENTION [0016] FIG. 1 illustrates a compressed gas dispensing system consisting of a hydraulic pressurization unit (HPU) 10 , which is connected to an over-the-road compressed gas semi trailer 40 . [0017] As illustrated by FIG. 1 , HPU 10 consists of a hydraulic fluid tank 11 , a hydraulic level gauge 13 , a particle filter 16 , a motor 21 , a coupling 23 , a pump 25 , a check valve 26 , a pressure sensor 27 , an outgoing fluid line 33 , and a fluid return line 91 . Additionally, HPU 10 consists of a capacity control sensor 93 , a photoelectric control sensor 95 , an incoming gas line 110 , a pressure sensor 111 , an actuated ball valve 112 , a hydraulic fluid separator 113 , a coalescing filter 115 , and an outgoing gas dispensing line 117 . An electric/electronic control panel (not visible), and programmable logic controller software complete HPU 10 . HPU 10 ensures that the compressed gas cylinders are charged to a specific pressure throughout the dispensing operation. In order to accomplish this, HPU 10 pumps hydraulic oil into the cylinders as gas is dispensed, in order to maintain a specific pressure. [0018] FIG. 1 also illustrates HPU 10 connected to an over-the-road compressed gas semi trailer 40 comprised of a gas cylinder module 39 , of which each module may consist of grouped sets of horizontal (tubular) cylinders (for example 61 a - d ), each with the same volume capacity. Cylinders carry compressed gas such as compressed natural gas (CNG), hydrogen, and other gases. Each module has a charging end 50 and a dispensing end 70 . Pressure gauges 41 , 55 , and a set of valves consisting of manual ball valves 43 , 57 , and actuated ball valves 51 a - d, 52 a - d are connected at the charging end 50 of module 39 . The upstream connection from actuated ball valves 51 a - d is connected to an incoming fluid line 37 . The upstream connection from actuated ball valves 52 a - d is connected to a fluid return line 81 . [0019] A set of valves consisting of actuated ball valves 71 a - d, a manual ball valve 75 , and a pressure relief valve 73 are connected at dispensing end 70 of cylinder module 39 . The downstream connection from actuated ball valves 71 a - d is connected to an outgoing gas line 83 . The over-the-road semi trailer is charged with compressed gas at another location. [0020] Cylinders are filled with compressed gas, typically using a compressor. A byproduct of the compression of the gas is heat, which ultimately raises the temperature of the gas in the cylinder. When a cylinder is filled to a specific pressure at a charging facility, for example 220 bar, that pressure will drop as the heat dissipates and the cylinder cools. When a series of cylinders reaches a dispensing location, the temperature of the cylinders has dropped, and as a result, the pressure of the cylinders has also dropped. Before gas can be dispensed from these cylinders, the gas pressure must be increased to the desired dispensing pressure, for example, 220 bar. In order to ensure minimal delay in charging a cylinder to a desired pressure once it arrives at a dispensing location, a system is utilized to boost the pressure in a cylinder while dispensing from another, [0021] Once cylinder module 39 is filled with compressed gas, the gas is transported to a gas dispensing station where HPU 10 is installed. The over-the-road compressed gas semi trailer 40 is connected to HPU 10 with three hoses: an outgoing fluid hose 35 , a return fluid hose 85 , and a gas hose 87 . [0022] In order to dispense gas from cylinder module 39 , the start button on the control panel (not visible) is pushed and HPU 10 begins unloading gas from the first cylinder 61 a in compressed gas module 39 on over-the-road semi trailer 40 . The electronic control panel (not visible) sends a signal to actuated ball valve 112 on HPU 10 and actuated ball valve 71 a on dispensing end 70 of module 39 , causing the valves to open, allowing the gas in cylinder 61 a to be dispensed. The gas dispensed from module 39 flows through outgoing gas line 83 and gas hose 87 until it reaches gas line 110 of HPU 10 . When the gas reaches line 110 of HPU 10 , the gas flows through pressure sensor 111 , actuated ball valve 112 , hydraulic fluid separator 113 , through coalescing filter 115 , through dispensing line 117 , and into gas line 120 . As the gas is dispensed from cylinder 61 a of module 39 , pressure sensor 27 , located downstream of check valve 26 , senses the hydraulic pressure drop in cylinder 61 a. When the pressure reaches a selected level, such as 210 bar or less, sensor 27 sends an electrical signal to the control panel (not visible). The control panel then sends a signal that simultaneously actuates motor 21 and opens actuated ball valve 51 a on the charging end 50 of cylinder 61 a. [0023] Motor 21 suctions the hydraulic fluid from tank 11 , forcing it through particle filter 16 to pump 25 . Pump 25 forces the hydraulic fluid through check valve 26 , outgoing fluid line 33 , and outgoing fluid hose 35 , until it reaches incoming fluid line 37 of the over-the-road semi trailer 40 . The hydraulic fluid flows through actuated ball valve 51 a and into cylinder 61 a, forcing the gas from cylinder 61 a out the dispensing end 70 of the module 39 . Once pressure sensor 27 senses the gas pressure has reached a selected pressure, such as 220 bar or 3190 psi, an electronic signal from the control panel (not visible) switches off motor 21 . Check valve 26 prevents hydraulic fluid from flowing back into tank 11 . [0024] As gas is being dispensed from cylinder 61 a, the pressure in cylinder 61 b is below the desired dispensing pressure due to the temperature drop and subsequent pressure drop experienced during transport of the cylinders from the charging station to the dispensing location. In order to charge cylinder 61 b to the desired dispensing pressure, cylinder 61 b is charged using a method comprised by the invention, and as outlined in the flow chart of FIG. 2 . The method requires bleeding gas from one cylinder into another. For example, referring to FIG. 3 , cylinder 61 a is being dispensed from, and cylinder 61 b will follow once cylinder 61 a is exhausted. In order to ensure that cylinder 61 b is at the desired pressure by the time cylinder 61 a is depleted, the pressure in cylinder 61 b is boosted at intervals by gas from cylinder 61 a. The boosting is controlled by the control panel (not visible). The control panel monitors the dispensing activity of module 39 , and in particular cylinder 61 a. When there has been a specified idle period in dispensing activity (i.e., actuated ball valve 112 is closed), the control panel sends a signal to actuated ball valves 71 a, 71 b, which had been closed and now open. The control panel monitors the flow of gas from cylinder 61 a to cylinder 61 b, and sends a signal to actuated ball valves 71 a, 71 b closing them after a specified amount of time. The amount of gas transferred from cylinder 61 a to cylinder 61 b is closely controlled and monitored by the control panel (not visible) to ensure that any pressure drop in cylinder 61 a caused by the boosting of cylinder 61 b is minimal. [0025] When pressure sensor 27 senses a drop in pressure in cylinder 61 a, it sends a signal to the control panel, which then functions as previously discussed, causing hydraulic oil to be pumped into cylinder 61 a until it reaches a desired pressure. The boosting process continues in this cycle, until pressure sensor 27 does not sense a drop in pressure when charging cylinder 61 b. If no pressure drop is detected, boosting is complete and cylinder 61 b has been charged to the desired pressure. The boosting of cylinder 61 b is done in small increments over an extended amount of time in order to minimize pressure drop in cylinder 61 a, and subsequently, to reduce charging time for cylinder 61 a. After cylinder 61 b has been charged to the desired pressure, the boosting process continues by boosting the pressure in the next available cylinder, for example cylinder 61 c. [0026] When cylinder 61 a is depleted, and gas is dispensed from cylinder 61 b, the boosting process continues with gas from cylinder 61 b boosting the remaining cylinders in the series that have not yet been boosted to the desired pressure. The process illustrated above continues until all of the cylinders in a series are boosted to a desired pressure. [0027] The gas is dispensed and the dispensing process discussed above is repeated until cylinder 61 a has been depleted. The hydraulic fluid is discharged from cylinder 61 a as discussed in U.S. patent application Ser. No. 12/435,078, herein incorporated by reference. [0028] When the discharge of hydraulic fluid from cylinder 61 a begins, the control panel begins unloading gas from cylinder 61 b (beginning another cycle). The cycle is repeated for each cylinder in a module until the entire module has been exhausted. The number of cylinders in a module, and the number of modules depends solely on the volume of gas that needs to be transported and the manufacturing standards of the over-the-road semi trailer. [0029] The invention has significant advantages. The boosting system is a cost effective means of increasing the efficiency of the dispensing activity by minimizing delay times associated with charging a cylinder to a desired dispensing pressure. The boosting system allows for timely and efficient transition from one cylinder to another within a module. [0030] While the invention has been shown in only a few of its forms, it should be apparent to those skilled in the art that it is not so limited but is susceptible to various changes without departing from the scope of the invention. For example, compressed gas may simultaneously be dispensed from more than one cylinder. Additionally, compressed gas may be bled from more than one cylinder simultaneously, and more than one cylinder may be boosted to a desired dispensing pressure simultaneously.

A fixed and/or stationary modular unit consists of a hydraulic fluid tank and a pressurization pump. A compressed gas transportation system consists of a set of cylinders. Each cylinder has a charging port and a dispensing port. A valve is connected at the dispensing port of each cylinder. Each of the valves at the dispensing ports of the cylinders are connected to one another. After an idle period of dispensing activity, the valves on the dispensing ports of the cylinders are opened and compressed gas is bled from one of the cylinders into at least one of the other cylinders in the set until the at least one of the other cylinders reaches a desired dispensing pressure. Hydraulic fluid is pumped from the tank into the cylinder being bled from to maintain a substantially constant pressure within the cylinder.

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The invention lies in the printing technology field. More specifically, the invention relates to an offset printing unit and a corresponding offset printing method. In rotary offset printing, the image to be printed is offset from a form cylinder onto a rubber blanket, and it is subsequently offset from the rubber blanket to the surface to be printed. Typically, the form cylinder is a plate cylinder, i.e., a roller which carries a printing plate onto which ink and water is applied in accordance with the image pattern on the plate. The rubber blanket typically forms the peripheral surface of a rubber blanket cylinder with the same diameter as the plate cylinder. Japanese patent application JP 7-266533 discloses a printing press in which the rubber blanket is formed by a blanket belt which is guided about two blanket rollers. The two blanket rollers have the same diameter as the plate cylinder. One of the guide rollers defines the offset nip between the plate cylinder and the blanket, and the other guide roller defines the printing nip (the line along which the ink is transferred onto the paper) between the blanket and the paper web. The object pursued by the Japanese disclosure, is to move the respective printing nips of the various printing units closer towards one another so as to reduce the disadvantageous effect of fan-out registration errors. Since, in the Japanese disclosure, the diameters of the blanket cylinders are equal to the diameters of the plate cylinder, and each of the printing units (each unit prints one color) thus require six such full-diameter cylinders for double-sided web printing, the construction costs for that printing press and the attendant space requirements are enormous. German published patent application DE 44 42 983 discloses a sheetfed printing machine with two plate cylinders which transfer a first and a second color to a common blanket belt. The blanket belt is guided about two blanket cylinders with the same diameter as the plate cylinders. The system is used to reduce the number of transfer cylinders for the paper sheets, but it does not have a bearing on the fan-out registration problem. The number of necessary cylinders (i.e., plate cylinders and blanket cylinders) is not reduced relative to the conventional prior art machines and the space needed for the printing units is the same as in conventional sheetfed printing units with conventional rubber blanket rollers. U.S. Pat. No. 5,907,997 discloses a satellite printing unit with four print and blanket cylinder couples that are arranged around a central impression cylinder. The system requires a substantial amount of space and, importantly, it can only be implemented with short ink trains and dampener trains. Moreover, the number of equal-diameter plate and blanket cylinders is not reduced. The term fan-out registration is a term used in the art to describe the effect of paper web expansion during the printing operation. As the paper web travels through the individual printing units, a considerable amount of ink and water are offset onto the web. The water thereby causes the web to expand. The primary expansion, due to the prevalent longitudinal alignment of the paper fibers in the web, is in the lateral direction, i.e., transverse to the web travel direction. This can lead to considerable misregistration among the various printing units, with the misregistration between the color of the first unit and the color of the last unit naturally being the most noticeable. The fan-out problem becomes especially pronounced in very wide printing machines, such as the four page wide machines with rollers having an axial length of more that 60 inches. Fan-out misregistration has conventionally been compensated for by a (predicted) shifting of the downline printing plates into better registration. That is, plate register pins are moved so that the position of the plate relative to the centerline of the printing machine will coincide with the predicted position of the preceding color after the expected amount of growth. Additionally, it has been known to subject the web to so-called bustle wheels just upline of each of the following printing units. The bustle wheels cause a slight crumpling and shrinking of the web just prior to its entry into the following printing nip (see, for example, U.S. Pat. Nos. 5,794,829 and 6,105,498). These counter-measures are only static solutions which compensate for predicted errors. They do not account for dynamic changes in the press such as varying web properties or varying print coverages. SUMMARY OF THE INVENTION It is accordingly an object of the invention to provide a rotary offset printing machine with a rubber blanket belt, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which reduces or eliminates fan-out registration errors and is enabled to reduce or eliminate color registration errors during make-ready without causing paper waste. With the foregoing and other objects in view there is provided, in accordance with the invention, an offset printing unit for printing a material web, comprising: a first form cylinder for transferring a first color, the first form cylinder having a form cylinder diameter; a second form cylinder for transferring a second color, the second form cylinder having the form cylinder diameter; a plurality of guide rollers respectively disposed in vicinity of the first and second form cylinders and of a material web to be imprinted, the guide rollers having a diameter smaller that the form cylinder diameter and/or a mass that is less than that of the form cylinders; and an endless blanket belt disposed to revolve around the guide rollers and to form with the first and second form cylinders respective offset nips at which the blanket belt receives the first color from the first form cylinder and the second color from the second form cylinder, and to form an impression nip with the material web at which the material web receives the first and second colors from the blanket belt. In accordance with an added feature of the invention, the first and second form cylinders are plate cylinders. In accordance with an additional feature of the invention, a third and a fourth form cylinder are disposed mirror-symmetrically to the first and second form cylinders across the material web, a further plurality of guide rollers disposed opposite the guide rollers across the material web, and a further endless blanket belt disposed to revolve about the further guide rollers, to form respective offset nips with the third and fourth form cylinders, and to offset colors received from the third and fourth form cylinders onto the material web across from the first above-mentioned impression nip. In accordance with an alternative embodiment of the invention, a third and a fourth form cylinder disposed to form respective offset nips with the blanket belt for offsetting onto the blanket belt a third and a fourth color respectively, and whereby the blanket belt simultaneously imprints onto the material web up to four colors at the impression nip. In accordance with another feature of the invention, the form cylinders have a diameter substantially twice the diameter of the guide rollers. In accordance with a further feature of the invention, two H-type units are stacked one above the other, each comprising at least two form cylinders, and wherein the guide rollers are disposed to form respective impression nips of the two H-type units at a spacing distance less than twice the form cylinder diameter. In accordance with a preferred embodiment of the invention, a camera is disposed at a location downline from the second form cylinder in a blanket belt travel direction and configured to record a coverage of the first and second color on the blanket belt, and a computer connected to the camera and to the form cylinders for setting a register of the first and second colors on the blanket belt in response to a signal received from the camera. With the above and other objects in view there is also provided, in accordance with the invention, an offset printing method, which comprises: providing an endless rubber blanket belt disposed to revolve about a plurality of guide rollers; offsetting a plurality of colors onto the blanket belt at respective offset nips formed between the blanket belt and a plurality of form cylinders disposed along a travel path of the blanket belt; ascertaining a register between the plurality of colors and continuing the offsetting step until register has been attained; and after register between the plurality of colors has been attained, throwing on the blanket belt onto a material web and simultaneously printing the plurality of colors at a single impression nip formed between the blanket belt and the material web. In accordance with again an added feature of the invention, four colors are offset onto each of two blanket belts disposed on opposite sides of the material web, and both sides of the web are simultaneously printed each with up to four colors. In accordance with a concomitant feature of the invention, four blanket belts are provided and each is configured to have offset thereon at least two colors. In this case, the material web is imprinted with at least two of the four blanket belts at respective impression nips disposed in close vicinity along the material web. The primary advantageous feature of the invention is thus the use of a single blanket from which at least two colors can be transferred from two form cylinders onto the print material. The problem of fan-out registration is therefore eliminated between the two colors. The blanket belt, furthermore, is guided about small-diameter guide rollers, which leads to a substantial savings in material cost and space requirement. The novel system no longer requires equal diameter plate and blanket cylinders and the system is not limited to short inkers. It has been found to be a further, yet substantial, advantage of the invention, that it is possible with the new system to completely adjust the register of different colors on the blanket belt before the belt is brought into contact with the paper web. Accordingly, the color register can be completely during make-ready, without wasting any paper. Due to the light-weight and smaller diameter construction of the guide rollers (two of which also form the impression rollers), it is possible to very quickly react to a web break. In that case, the low-mass rollers can be quickly retracted out of contact with the paper web. It is yet a further advantage of the invention that the number of motors can be reduced. For example, in a five high printing tower (CMYB, plus an extra color) with three motor drives, it is possible to save four motors and the plate cylinders can be evenly spaced along the printing units. Several auxiliary units can be dispensed with in accordance with the invention. For example, only a single blanket washer is required for each belt. If the belt is used as a four-color offset blanket, for example, three blanket washers can be eliminated as compared with the prior art system. Finally, by utilizing segmented blanket belts which can be selectively lengthened and shortened, it is possible to change over among a variety of systems, as will become clear from the following description of the preferred embodiments. Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a printing machine with a rubber blanket belt, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. The construction of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of the specific embodiment when read in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic side view of a stack of two H-type printing units; FIG. 2 is a side view of the two printing after conversion to separate and independent printing; FIG. 3 is a diagrammatic side view of a stack of two printing units with a common blanket belt for multicolor offset; and FIG. 4 is a partial diagrammatic side view of the impression nips with separate counter pressure rollers; DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is seen a first H-type printing unit 1 and a second H-type printing unit 2 stacked on the first printing unit 1 . The H-type units are to be understood as exemplary only. The inventive concept applies to a variety of configurations, such as to arch-type printing units, and the like. A web 3 travels centrally in the printing units, entering unprinted (0/0) at the bottom and exiting with up to four colors on each side (4/4) at the top. Each of the printing units 1 , 2 in FIG. 1 includes four plate cylinders. The plate cylinders that carry the image of one side of the web 3 (the left side) in four colors are successively identified as C 1 , C 2 , C 3 , and C 4 . The image on the other side of the web 3 (the right side) is defined by the cylinders C 5 , C 6 , C 7 , and C 8 . Each of the plate cylinders is assigned a dampener train 4 and an ink train 5 . Only one such system is illustrated for clarity. An endless rubber blanket belt 6 revolves about guide rollers 7 , 8 , and 9 . Print couples are formed between each of the plate cylinders and the belt 6 . The two colors which are offset onto the blanket belt 6 at the print couples 7 /C 2 and 8 /C 1 are transferred to the web 3 at a blanket belt to web nip 10 . As seen in FIG. 1, the horizontally mirrored configuration of the belt 6 of the printing unit 2 assures that a blanket belt to web nip 11 is located in close vicinity to the nip 10 . Furthermore, the smaller diameter of the guide rollers 9 and 12 , as well as 9 ′ and 12 ′, allows the impression nips to be located very close to one another with reference to the imprint location on the web 3 . This is important with regard to fan-out registration. By imprinting at the nip 11 immediately after imprinting at the nip 10 , the web 3 is not able expand to any appreciable degree, and fan-out registration errors are thus avoided. It is seen as critical, with regard to fan out registration, that the diameters of the guide rollers 9 and 12 ( 9 ′ and 12 ′) be chosen to be smaller than the diameters of the form cylinders C 1 . . . C 8 . The embodiment illustrated in FIG. 1 utilizes the guide roller 12 as the counter-pressure roller for the imprint on the front side of the web 3 . The roller 9 , conversely, is utilized as the counter-pressure roller for the imprint on the back side of the web 3 . Referring now to FIG. 2, the two printing units 1 and 2 can also be operated independently of one another. In this case, the web 3 that enters the printing unit 1 from below exits from between the two units 1 and 2 after having been imprinted with a maximum of two colors 2/2 on each side. A web 3 ′ is fed into the space between the printing units 1 and 2 and runs through the upper printing unit 2 . From there the web 3 ′ exits with a maximum of two colors 2/2 on each side. Referring now to FIG. 3, there is illustrated a further variation of the inventive concept. Here, four colors are offset onto the blanket belt 6 and the four colors are simultaneously imprinted onto the web 3 in a single blanket to web nip. Due to the simultaneity of the multi-color imprint, the registration problems associated with the fan-out phenomenon are completely eliminated in this embodiment. It is also advantageous that only a single blanket washer 17 is necessary per blanket belt. A further advantage becomes apparent: It is possible with this embodiment of the invention to completely set the color register during make-ready without wasting any paper. For this purpose, a camera 13 is positioned downstream of the last print couple 8 /C 1 in the travel direction of the web, i.e., between the last print couple and the blanket belt to web nip. The camera 13 is connected to a color control processor or the printing unit controller. The camera provides the necessary information with regard to location of the four colors that have been offset from the cylinders C 4 , C 3 , C 2 , and C 1 as the blanket belt 6 travels by in the counter-clockwise direction. The information signal from the camera 13 is processed and corresponding signals are sent to the various setting actuators from the printing unit processor, so that the register and the proper color controls may be set. During the make-ready registration process, the guide rollers 9 and 12 are thrown off (dashed positions 9 ′ and 12 ′) so that the blanket belt 6 does not touch the web 3 . The web 3 , therefore, stands still during the make-ready operation and no paper is wasted. FIG. 4 illustrates an embodiment of the invention which allows selective one-sided printing on the web 3 without taxing the opposite-side blanket belt as a counter-pressure element. The guide roller 9 (which defines the front-side blanket to web nip) here is countered by a counter-pressure roller 14 and the guide roller 12 (which defines the backside blanket to web nip) is countered by a counter-pressure roller 15 . The rollers 14 and 15 are preferably soft rubber rollers, or the like. The blanket belt 6 , furthermore, is suitable deflected by a guide roller 16 . In this embodiment, therefore, it is possible to imprint the web 3 only on one side, and throw off the guide roller for the opposite blanket belt for make-ready of a further print job. The blanket washer 17 is placed so that the belt is washed after it leaves the impression nip and before it reaches the first plate cylinder C 4 , C 8 . Any number of tension control elements 18 are strategically distributed along the run of the blanket belt 6 . Only one web tensioner 18 is illustrated in FIG. 3 . As noted above, the fact that the diameter of the blanket belt guide rollers 9 and 12 is smaller than the diameter of the form cylinders C 1 . . . C 8 is critical with regard to fan out registration. Similarly, it is critical with regard to quick throw-off and offset stoppage upon a web break or other print interruption that the guide rollers 7 , 8 , 9 , 12 , 7 ′, 8 ′, 9 ′, 12 ′ (and 14 , 15 ) about which the blanket web travels have a smaller mass than the form rollers. In this case, it is not necessary that the guide rollers have a smaller diameter, but merely that they have less mass. Specifically in the embodiment illustrated in FIG. 3 —with a single impression nip for all colors—the smaller diameter of the guide rollers is not as critical as their smaller mass.

The web-fed rotary offset printing machine utilizes a blanket belt onto which two or more colors are offset and which prints the two or more colors at once onto a material web. The blanket belt travels about guide rollers which have a lesser mass and/or a lesser diameter than the form cylinders which offset the colors onto the blanket belt. If several impression nips—blanket to web nips—are formed along the travel path of the material web, they are located so close to one another that fan out register errors cannot occur.

FIELD OF THE INVENTION [0001] The invention relates to an automatic cleaner for submerged surfaces, particularly in a swimming pool. BACKGROUND TO THE INVENTION [0002] Automatic swimming pool cleaners of various types are widely known. One group of these has driven wheels, which carry them across submerged surfaces. They may either be suction or pressure operated. [0003] As with all such automatic cleaners, the ongoing quest is to provide random navigation, without a repeated pattern, and to avoid the cleaner getting trapped against obstacles. [0004] U.S. Pat. No. 6,782,578 which is limited to a pressure operated pool cleaner suggests at temporarily lifting one wheel or propping one side of the cleaner away from the pool surface to interrupt synchronous rotation of first and second wheels on the pool surface. The suggestion is anticipated by U.S. Pat. No. 5,197,158. The earlier patent discloses a random travel mechanism, located centrally between front and rear wheels and to one side of the cleaner. The mechanism periodically lifts the wheels on that side to cause a skewing of the direction of travel. These teachings with regard to such steering or interrupting mechanisms are respectively insufficient and complicated. From a commercial point of view, it is submitted that there remains room for improvement. OBJECT OF THE INVENTION [0005] It is an object of the present invention to provide a swimming pool cleaner of the kind referred to which at least partially satisfies the quest. SUMMARY OF THE INVENTION [0006] In accordance with this invention there is provided a swimming pool cleaner having a pair of side wheels connected to be driven by a turbine to move the cleaner in a direction of travel along a submerged surface with a cam adjacent at least one of the wheels to intermittently extend a gripping formation beyond the operatively supporting surface of the at least one wheel. [0007] The invention further provides for the gripping formation to impart movement to the cleaner opposite to the direction of travel. [0008] Further features of the invention provide for the cam to be rotatably mounted on an axle for the at least one wheel; for the cam to be rotated in the opposite direction to the at least one wheel; for the cam to be arcuate with at least one radial gripping formation on its outer surface; and for the gripping formations to be removably securable to the cam. [0009] Further features of the invention provide for the cam to be driven in a cycle retarded relative to that of the wheels; for a turbine drive shaft to be connected through gearing to an axle connecting the side wheels, which axle is connected through gearing to a ring gear on the cam; and for a cam to be provided adjacent each of the side wheels. [0010] Further features of the invention provide for the wheels to be adapted to receive a flotation or ballast body; for the wheels to have tread that securably engages over hub-caps; and for the cleaner to have a second pair of wheels also driven by the turbine. [0011] Further features of the invention provide for the turbine to be in a housing having an inlet at the underside of the cleaner with a skirt arranged around the inlet to extend downwardly from the underside of the cleaner with at least part of the skirt movably suspended so its free edge is movable inwardly against a resilient bias. [0012] In accordance with another aspect of this invention there is provided a swimming pool cleaner having a pair of side wheels connected to be driven by a turbine, with a cam adjacent at least one of the wheels to intermittently extend a gripping formation beyond the operatively supporting surface of the at least one wheel and in which the cam is rotatably mounted on an axle for the at least one wheel. BRIEF DESCRIPTION OF THE DRAWINGS [0013] These and other features of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: [0014] FIG. 1 shows a plan view of a swimming pool cleaner; [0015] FIG. 2 shows a part cutaway perspective view of the cleaner; [0016] FIG. 3 shows a side cross-sectional view; [0017] FIG. 4 shows a bottom perspective view; [0018] FIG. 5 shows an exploded view of a wheel for the cleaner; [0019] FIG. 6 shows a turning cam for a swimming pool cleaner; and [0020] FIG. 7 shows a bottom perspective view of a cleaner with an alternative skirt arrangement. DETAILED DESCRIPTION OF THE INVENTION [0021] Referring to the drawings, a swimming pool cleaner in accordance with this invention is indicated generally by reference numeral ( 1 ). The cleaner ( 1 ) is shown without any body panels. [0022] The cleaner ( 1 ) includes a frame ( 2 ), in the form of a pan, which has a pair of side wheels ( 3 ) adjacent its rear end. The rear wheels ( 3 ) have tread ( 4 ) of flexibly resilient material and are fixedly mounted on an axle ( 5 ). The axle ( 5 ) is connected through gears ( 6 ) to the drive shaft ( 7 ) extending from a turbine ( 8 ). The turbine ( 8 ) is mounted in a housing ( 9 ) on the frame ( 2 ). [0023] Extending upwardly at the top of the housing ( 9 ) is an outlet ( 10 ). The outlet ( 10 ) is connectable to a swimming pool filter pump by a line of flexible hose (not shown) in the usual manner. An opening ( 11 ) in the frame ( 2 ) below the housing ( 9 ) provides an inlet. [0024] Mounted rotatably about the wheel axle ( 5 ) is a pair of annular cams ( 12 ). Each is adjacent and inwardly of a side wheel ( 3 ). The cams ( 12 ) are of a smaller diameter than the wheels ( 3 ), but carry radial gripping formations ( 13 ) on part of their circumference. These formations ( 13 ) extend beyond the tread ( 4 ) on the wheels ( 3 ). [0025] Each cam ( 12 ) includes a disc ( 14 ) carrying a ring gear ( 16 ) extending laterally towards the frame ( 2 ). The outer periphery of the gear ( 16 ) is formed as a channel (not shown) which removably receives the gripping formations ( 13 ). The number, size and position of such formations ( 13 ) on the cam ( 12 ) are thus variable. [0026] A layshaft ( 17 ) supported at the rear end of the frame ( 2 ) extends between the cams ( 12 ) and has sprockets ( 18 ) at its ends which engage the teeth of the gear ( 16 ) to provide rotation of the cams ( 12 ) in the opposite direction to that of the wheels ( 3 ). A further pair of gears ( 19 ) connects the axle ( 5 ) and layshaft ( 17 ) to transmit rotation imparted to the axle ( 5 ) from the turbine ( 8 ). [0027] The side edges of the frame ( 2 ) are provided with walls ( 20 ) that extend along the length of the frame ( 2 ). A pair of front wheels ( 21 ) is also mounted at the sides of the cleaner ( 1 ). The wheels ( 21 ) have the same tread ( 4 ) and are connected by a front axle ( 22 ). A connecting shaft ( 23 ) extends between the rear axle ( 5 ) and front axle ( 22 ). A pair of cooperating bevel gears ( 24 ) and ( 25 ) respectively at the front and rear ends of the shaft ( 23 ) transmits rotation from the rear ( 5 ) to the front ( 22 ) axle. This arrangement drives the front wheels ( 21 ). The sidewalls ( 20 ) curve upwardly at the front and rear of the frame ( 2 ). The front and rear are shaped so as not to extend beyond the four wheels ( 3 ) and ( 21 ) to any significant degree. [0028] At the front of the frame ( 2 ) is a bumper ( 26 ). The bumper ( 26 ) is mounted spaced apart forwardly from the cleaner ( 1 ) on a pair of supports ( 27 ). The front edge of the bumper ( 26 ) is curved, from the middle, rearwardly towards the two front wheels ( 21 ). The sidewalls ( 20 ) of the frame ( 2 ) extend downwardly to adjacent the operatively supporting surfaces at the bottom of the four wheels ( 3 ) and ( 21 ). Across the width at the front and rear of the frame ( 2 ) are downwardly extending movable flaps ( 28 ). The sidewalls ( 20 ) and flaps ( 28 ) provide a skirt ( 29 ) around the inlet ( 11 ) at the periphery of the frame ( 2 ). The flaps ( 28 ) are hinged to the frame ( 2 ) at ( 30 ). Extending from the flaps ( 28 ) adjacent the hinges ( 30 ) are levers ( 31 ). The levers ( 31 ) have spaced apart transverse grooves ( 32 ), each of which can removably receive a catch ( 33 ) at the free end of a spring ( 34 ). The other end ( 35 ) of the spring ( 34 ) is anchored to the frame ( 2 ). The tension in the spring ( 34 ) is variable by adjusting the position of the catch ( 33 ) between the grooves ( 32 ). The springs ( 34 ) resiliently bias the lower edges ( 36 ) of the flaps ( 28 ) downwardly. The flaps ( 28 ) adjacent their free, lower edges ( 36 ) are curved inwardly and upwardly. It will thus be understood that part of the skirt ( 29 ) is hingedly suspended so its free edge ( 36 ) is movable inwardly. Furthermore, the parts or flaps ( 28 ) are resiliently biased into their downwardly extending position. [0029] The wheels ( 3 ) and ( 21 ) are provided with a cavity ( 37 ) to receive an annular body ( 38 ) therein. The body ( 38 ) will either be provided as a float or as ballast, depending on the required tuning of the cleaner ( 1 ). A circlip ( 39 ) engages on the end of the axle ( 5 ; 22 ) to secure the wheels ( 3 ; 21 ) in place. The body ( 38 ) can then be located in the cavity ( 37 ) of the wheel ( 3 ; 21 ) after which a hub-cap ( 40 ) is positioned against the outer edge of the wheel ( 3 ; 21 ). At the outer edge of the tread ( 4 ), an inwardly extending annular lip ( 41 ) is provided. The resiliently flexible lip ( 41 ) is located over the peripheral edge of the hub-cap ( 40 ) to retain it in place over the body ( 38 ). [0030] In use, the flow of water from the inlet ( 11 ) to the outlet ( 10 ) under action of the pump rotates the turbine ( 8 ) to drive the side wheels ( 3 ) and ( 21 ), which will impart forward motion to the cleaner ( 1 ). The gearing ( 19 ) that drives the cams ( 12 ) is selected so that their cycle of rotation is slower than that of the wheels ( 3 ). The gripping formations ( 13 ) of the reverse rotation cams ( 12 ) intermittently extend beyond the bottom of their respective wheels ( 3 ). The cleaner ( 1 ) advances in a fixed direction along an operating surface until one of the gripping formations ( 13 ) comes into contact with the surface. The wheel ( 3 ) adjacent the cam ( 12 ) is then lifted off the surface. The lifting also inhibits the traction of the front wheel ( 21 ) on the same side of the cleaner ( 1 ). The gripping formation ( 13 ) on the cam ( 12 ) imparts movement to the tilted side of the cleaner ( 1 ) which is opposite to that resulting from the forwardly rotating wheels ( 3 ) and ( 21 ). The cleaner ( 1 ) thus turns under the influence of the cam ( 12 ) and the wheels ( 3 ) and ( 21 ) on the opposite side of the cleaner ( 1 ). With the other wheels ( 3 ) and ( 21 ) in contact with the pool surface, the cleaner ( 1 ) pivots under the resulting turning moment created about the cam ( 12 ). [0031] The gripping formations ( 13 ) of the two cams ( 12 ) are located at different relative positions so that they will not engage the surface and lift both rear wheels ( 3 ) at the same time. [0032] When the cleaner ( 1 ) engages an obstacle, the wheels ( 3 ) and ( 21 ) will spin until one of the cams ( 12 ) turns the cleaner ( 1 ) away from the obstruction. The turning is facilitated by the curved bumper ( 26 ), which assists the front end of the cleaner ( 1 ) to disengage the obstacle. [0033] The skirt ( 29 ) contains a low pressure area below the frame ( 2 ) under the suction of water through the inlet ( 11 ) by the pump. This provides a force on the cleaner ( 1 ) to hold it against submerged surfaces and thus afford traction to the wheels ( 3 ). This also enables the cleaner ( 1 ) to climb vertical walls. The pivotable flaps ( 28 ) of the skirt ( 29 ) serve to prevent the cleaner ( 1 ) from getting stuck by creating a vacuum on, for example, a bump on the floor of a pool. [0034] Dirt or debris in the immediate vicinity of the cleaner ( 1 ) and specifically within the area under the skirt ( 29 ) is sucked through the inlet ( 11 ), past the turbine ( 8 ) and to the filter pump. [0035] The gripping formations ( 13 ) on the cams ( 12 ) can be adjusted as required for specific conditions, such as the size of a pool to be cleaned. It will be appreciated that by varying the size, number and position of the gripping formations ( 13 ) so too will the movement pattern of the pool cleaner ( 1 ) be varied. The gearing that drives the wheels ( 3 ; 21 ) and cams ( 12 ) will determine their relative speeds of rotation and this will also affect the pattern of movement. [0036] FIG. 6 shows a cam ( 12 ) which has three lipped projections ( 42 ). One of these is shown fitted with an engaging formation ( 13 ). The formation ( 13 ), which is made of flexibly resilient material, has a slot (not shown) which provides an interference fit onto the projection ( 42 ). A pair on these cams ( 12 ) will be fitted to a pool cleaner ( 1 ) with the projections offset from each other to avoid simultaneous lifting of the rear wheels ( 3 ). It will be appreciated that the projections ( 42 ) themselves do not extend beyond the tread of the wheels ( 3 ) when the cam ( 12 ) is in place on the cleaner ( 1 ). [0037] Different arrangements for securing gripping formations to the arcuate cams will be within the design competence of a suitably skilled person. [0038] The embodiment of the cleaner ( 1 ) shown in FIG. 7 has an alternative skirt ( 29 ) arrangement around the inlet opening ( 11 ). Front and rear flaps ( 43 ) are made from flexibly resilient elastomeric material. Each flap ( 43 ) has four holes ( 44 ) spaced apart adjacent one edge, opposite to the free edge. These holes ( 44 ) will be pressed onto co-operating enlarged formations (not shown) located on the bottom of the frame ( 2 ). The flaps ( 43 ) are movable within the sidewalls ( 20 ) of the cleaner ( 1 ), under the inherent nature of the material from which they are made. This movement is subject to the configuration of the flaps ( 43 ) with the positioning of ribs ( 45 ) and outer lips ( 46 ) to limit movement in these areas. [0039] In addition, sidewalls ( 20 ) are recessed between the wheels ( 21 ) and ( 3 ) to receive side flaps ( 47 ). These flaps ( 47 ), which extend laterally between the wheels when in place on the cleaner ( 1 ), are made of the same flexibly resilient material as flaps ( 43 ). Four upward extensions ( 48 ) on each flap ( 47 ) provide an interference fit to corresponding holes (not shown) in the bottom of the frame ( 2 ). The side flaps ( 47 ) assist in maintaining the low pressure area below the frame ( 2 ). The flaps ( 47 ) are cured inwardly at ( 49 ) to allow passage of the formations ( 13 ) on the cams ( 12 ). [0040] It is common to have the float of a pool cleaner spaced apart from the surface engaging portion thereof. The ballast or weight is normally located close to the surface engaging portion. The combination of a weight and a float are balanced to hold the cleaner in a required orientation when submerged during operation. This often results in a turning moment between these spaced apart components which tends to break contact between the cleaner and the surface being cleaned under certain circumstances. Wheels ( 3 ; 21 ) of the construction shown enable tuning with flotation material or ballast which can be used to mitigate the problem of a turning moment. It will be appreciated that depending on the nature of the body ( 38 ), either a float or a weight can be secured to the frame ( 2 ) of the cleaner ( 1 ). [0041] The pool cleaner ( 1 ) also has a collapsible wheel assembly, which may include both flexibly resilient wheel components and a flexibly resilient wheel suspension. In the embodiment shown in the drawings, it is the wheel tread ( 4 ) that contributes to the flexibly resilient construction. The arrangement supports the underside of the cleaner ( 1 ) off a surface but gives way under any substantial load when the underside of the frame ( 2 ) provided by the lower edges of the sidewalls ( 20 ) will be pressed against the surface. This protects the components against damage. The cams ( 12 ) will, like the wheels ( 3 ), also add a degree of resilience to the suspension. [0042] It will be appreciated by suitably skilled persons that a number of variations may be made to the features of the described embodiment without departing from the scope of the invention. [0043] The cams ( 12 ) need not be annular, and a number of different gear and transmission arrangements for the wheels ( 3 ) and cams ( 12 ) may be used. For example, in a variation of the cam operation, a foot can be driven to extend an inwardly biased engaging formation to engage the operating surface. The formation can extend forwardly from the frame at a suitably inclination to lift an adjacent wheel and to impart the required rearward movement to the frame as it extends. Such an engaging formation could be mounted on an elongate arm which may be curved. As a further alternative, the gripping formation may be provided on an arm having the teeth of a rack along it. The cam will be provided as a co-operating pinion with corresponding teeth on only part of its circumference. The cam will engage the rack only intermittently to extend the engaging formation against an inward bias. [0044] The cleaner may alternatively be of the pressure operated kind, wherein dirt is entrained and carried into a collection net in known manner.

The invention relates to a swimming pool cleaner which is intermittently-turned from its path of travel along an underwater surface. A pair of side wheels ( 3 ) connected to be driven by a turbine ( 8 ) to move the cleaner in a direction of travel. A cam ( 12 ) is provided inwardly of and adjacent to each of the wheels. The cams are rotatably mounted on the wheel axles ( 5 ). Each cam intermittently extends a gripping formation ( 13 ) beyond the operatively supporting surface of the wheel. The cams and gripping formations are arranged so that, when they engage the pool surface, they impart movement to the cleaner which is in the opposite direction to the direction of travel. The cams are preferably arcuate, with at least one radial gripping formation. The rotation of the cams is opposite to that of the wheels and they are driven in a cycle retarded relative to that of the wheels. The gripping formations are removably securable for adjustment on the cams.

BACKGROUND OF THE INVENTION The present invention is directed generally to the use of porous solids as harborages for crawling terrestrial animals such as roaches, ants, and mice, and more particularly to the use of porous solids comprising a three dimensional array of cages connected to each other in such a manner as to present said terrestrial animals with a minimum of three alternative openings whenever said terrestrial animals are in contact with said harborages. THE PRIOR ART Harborages in the forms of bait stations and sticky traps are employed by homeowners, professional pest control technicians and other persons who are interested in the control of roaches, rats, mice and other crawling vermin. These pest control harborages of the known art offer the advantages of decreased hazard to man, pets and the environment; sticky traps use no pesticides at all, and bait stations use a very small amount of pesticide which is enclosed in a relatively tamper-proof metal or plastic housing. However, despite their advantages of safety and convenience, pest control harborages of the prior art are relatively unattractive to the target animals in the limited range of physical environments in which they can be used and are therefore little used in comparison to more common, but potentially more hazardous pest control methods such as spraying, dusting and the application of loose baits. There is therefore a need for a pest control harborage with a broader range of applications and greater acceptability to target animals in the terrestrial environment. Harborages for crawling terrestrial animals are also employed in the pet industry, particularly as tubular artificial habitats for hamsters, rats, mice and the like. These artificial habitats have the advantages of being transparent and permitting easy observation of pets as they crawl through them. However, these tubular artificial habitats are difficult to clean, are limited in their organizational complexity and soon cease to stimulate exploratory activity in hamsters and other pets. When the exploratory activity of the pets decreases, the entertainment value of the pets is thereby lessened. There is therefore a need for an artificial habitat for hamsters, rats, mice and the like that is easy to clean and which can be arranged in structures of sufficient and varying complexity as to continue to stimulate exploratory activity in hamsters and other pets for a longer period of time, thereby increasing the entertainment value of the pets for their owners. Heretofore, artificial harborages intended for crawling terrestrial animals have been constructed in the forms of bait stations, traps or tubular habitats. These harborages of the prior art have the disadvantages of presenting target animals with only a few rigid openings through which the animals must pass in order to enter the interior of the harborage. Animals which explore the exteriors of harborages of the known art encounter only one or two alternative openings at any one time. Terrestrial crawling animal harborage designs of the prior art do not anticipate a harborage constructed according to the present invention which is comprised of a porous solid and which presents the target animals with a choice of several discrete openings through which the animals may attempt to enter the harborage when they explore the harborage from without. Furthermore, terrestrial crawling animal harborage designs of the prior art do not anticipate a harborage constructed according to the present invention which invention presents target animals with a sequence of discrete openings arranged in a manner that allows the target animals to perceive a series of openings arranged at increasing distances from their bodies whether the target animals are inside or outside the harborage. Surprisingly, cockroaches were observed to use their antennae to reach inside harborages of the present invention and to explore openings at depths within the harborage equivalent to one to several body lengths of the target animals. This exploratory behavior demonstrates the surprising attractiveness of a complex array of openings presented at a variety of angles by a harborage of the present invention, which openings can be readily explored by the sensory organs of crawling animals. Examples of such sensory organs of crawling animals are the antennae, mouthparts, legs and cerci of insects; and the vibrissae, guard hairs and tails of mice and other rodents. In addition, harborage designs of the prior art do not anticipate a harborage constructed according to the present invention which allows the harborage to be used in high temperature environments. Moreover, harborage designs of the prior art do not anticipate a flexible harborage constructed according to the present invention which is useful in irregular spaces and around moving parts of machinery, motorized equipment and the like. When used in pest control, harborages of the known art typically contain a solid or liquid toxic bait in an interior tray or chamber. Alternatively, they may have an adhesive or toxicant on their internal surfaces. The toxicants used in harborages of the prior art are intended to control the pest animals themselves and, in some embodiments, to control parasites of the pest animals. It will therefore be understood by those skilled in the art of pest control that harborages of the present invention may be used in conjunction with biologically active agents belonging to the group consisting of adhesives, attractants, toxicants, sterilants, growth regulators, pheromones, parasiticides, nematodes, viruses, bacteria and fungi. IMPORTANCE OF ENTRANCES Bait stations of the prior art intended for roaches and other crawling arthropods have been constructed with up to six entrances, all of which are in the same plane. Bait stations and tubular habitats of the prior art intended for rats, mice and other small mammals have been constructed with from one to several entrances. Stations of the prior art which employ a single large entrance have the advantage of allowing target animals to enter from a wide variety of directions but are nevertheless surprisingly unattractive to target animals. Accordingly, artificial harborages or stations of the prior art which are constructed with smaller entrances have entrances which are individually more attractive than the entrances of stations with single large entrances. However, stations of the known art with small entrances are nevertheless rendered relatively ineffective by the restrictions which a small number of entrances places on the directions from which the stations may be entered by target animals. Despite the fact that the foregoing facts are well known to those skilled in the art, harborages of the prior art have not been designed to provide a high level of attractiveness to target animals approaching them from a wide range of directions. Moreover, harborages constructed according to the prior art do not anticipate a harborage of the present invention which is highly attractive to target animals approaching from a wide range of directions. In addition, harborages of the prior art fail to lure target animals away from naturally occurring harborages such as cracks, crevices and the like without the use of chemical attractants. Furthermore, harborages of the prior art require the use of adhesives, baits, arrestants and the like in order to encourage animals to remain inside for more than a brief time. Typical of rodent bait stations of the prior art are those described in U.S. Pat. No. 4,619,071 to Willis, 1986 Oct. 28, in U.S. Pat. No. 4,637,162 to Sherman, 1987 Jan. 20, and in U.S. Pat. No. 4,660,320 to Baker et al, 1987 Apr. 28 each of which present only two openings through which rodents may enter. U.S. Pat. No. 4,769,942 to Copenhaver 1988 Sep. 13, U.S. Pat. No. 4,768,305 to Sackett 1988 Sep. 6 and U.S. Pat. No. 4,630,392 to Ferraro 1986 Dec. 23 present only one small opening through which rodents may enter. Typical of roach bait stations of the prior art are U.S. Pat. No. 4,048,747 to Shanahan et al 1977 Sep. 20 which describes a trap suitable for mounting along the bottom of a wall and having only a single exterior opening running in a straight line along its lower side, U.S. Pat. No. 3,704,539 to Alvarez 1972 Dec. 5 which describes a station with only a single exterior opening running around its circumference. Typical examples of roach harborages having more than one exterior opening are given in U.S. Pat. No. 2,328,590 to Weil 1943 Sep. 7, U.S. Pat. No. 2,328,591 to Weil 1943 Sep. 7, U.S. Pat. No. 2,340,255 to Weil 1944 Jan. 25, U.S. Pat. No. 2,340,256 to Weil 1944 Jan. 25 and U.S. Pat. No. 4,696,127 to Dobbs 1987 Sep. 29 which describe stations with two openings, U.S. Pat. No. 4,400,905 to Brown 1983 Aug. 30 which describes a station with two or three openings, U.S. Pat. No. 4,044,495 to Nishimura et al 1977 Aug. 30 which describes a station with two or four openings, and U.S. Pat. No. 1,566,199 to Gaskins 1925 Dec. 15 which describes a station with four openings. U.S. Pat. No. 4,350,122 to Shotwell 1982 Sep. 21 describes a tubular collar with various arrangements of openings along its interior margin and intended as a non-toxic trap for fleas on dogs, cats and the like. None of the embodiments of the device described in U.S. Pat. No. 4,350,122 to Shotwell 1982 Sep. 21 offers target animals a series of alternative openings arranged in depth as do harborages of the present invention. Therefore, target animals entering or inside a harborage of type described in U.S. Pat. No. 4,350,122 to Shotwell 1982 Sep. 21 are only able to perceive one opening or entrance at any one time instead of the multiple openings or entrances that can be perceived by target animals entering or inside a harborage of the present invention. Furthermore, U.S. Pat. No. 4,350,122 to Shotwell 1982 Sep. 21 does not anticipate the importance of the relationship between the size of the openings and the effective exploring distances of the target animals as described in the present invention. Moreover, U.S. Pat. No. 4,350,122 to Shotwell 1982 Sep. 21 does not anticipate use of the disclosed harborage as an artificial habitat for pet rodents. Finally, U.S. Pat. No. 4,350,122 to Shotwell 1982 Sep. 21 does not anticipate the value of terrestrial animal harborages of the present invention in high temperature environments. U.S. Pat. No. 4,947,791 to Laier et al 1990 Aug. 14 describes a system of flexible, buoyant devices suitable for use as artificial reefs for fish. The devices disclosed in U.S. Pat. No. 4,947,791 to Laier et al 1990 Aug. 14 are not intended to be in contact with the substrate and are therefore not suitable for attraction of crawling animals such as roaches, ants and rodents as are the harborages of the present invention. Furthermore, the devices disclosed in U.S. Pat. No. 4,947,791 to Laier et al 1990 Aug. 14 are unstable and will move in response to water currents, thereby making them less attractive to crawling animals than harborages of the present invention which are firmly fixed on the substrate. Moreover, the devices disclosed in U.S. Pat. No. 4,947,791 to Laier et al 1990 Aug. 14 are comprised of plastics materials and are therefore not suitable for use in high temperature environments as are the harborages of the present invention. Furthermore, those skilled in the art of pest control will appreciate that adhesives will run out of the devices described in U.S. Pat. No. 4,947,791 to Laier et al 1990 Aug. 14 much more easily, for example under conditions of high temperature or high humidity, than the same adhesives will run out of the more porous harborages of the present invention. Those skilled in the art of pest control will further appreciate that the loss of adhesive from the devices described in U.S. Pat. No. 4,947,791 to Laier et al 1990 Aug. 14 will render the devices ineffective in pest control and will contaminate the substrate with unwanted adhesive. In addition, U.S. Pat. No. 4,947,791 to Laier et al 1990 Aug. 14 does not anticipate the important relationship between the sizes of openings into and out of the device and the effective exploratory distance of the animals it is intended to harbor. Furthermore, the devices disclosed in U.S. Pat. No. 4,947,791 to Laier et al 1990 do not anticipate the importance of thigmotaxis to the attractiveness of such devices to crawling animals as is described in connection with harborages of the present invention. Finally, the devices disclosed in U.S. Pat. No. 4,947,791 to Laier et al 1990 Aug. 14 do not anticipate use for control of crawling animals such as insects and rodents or use as harborages for pet rodents as is described for harborages of the present invention. U.S. Pat. No. 3,561,402 to Ishida et al 1971 Feb. 9 describes an elongate tubular artificial reef for fish comprised of various arrangements of perforated plates loosely held together by rings. The loose fitting rings which connect the porous plates of the devices described in U.S. Pat. No. 3,561,402 to Ishida et al 1971 Feb. 9 allow these plates to be moved by water currents or by the activity of animals crawling over them, thereby making the devices described in U.S. Pat. No. 3,561,402 to Ishida et al 1971 Feb. 9 less attractive to such crawling animals than are the stable harborages of the present invention. Furthermore, the porous plates and rings of the devices described in U.S. Pat. No. 3,561,402 to Ishida et al 1971 Feb. 9 are not suitable for use with adhesives as are the harborages of the present invention. Those skilled in the art of pest control will recognize that adhesives will be much more likely to run out of the structures illustrated in U.S. Pat. No. 3,561,402 to Ishida et al 1971 Feb. 9, for example under conditions of high temperatures or high humidity, than the same adhesives would be likely to run out of the more porous harborages of the present invention. Those skilled in the art of pest control will appreciate that the loss of adhesive from the structures illustrated in U.S. Pat. No. 3,561,402 to Ishida et al 1971 Feb. 9 will render the structures ineffective in controlling pests and will contaminate the substrate with unwanted adhesive. Moreover, addition of an adhesive to the interior surfaces of the device in FIG. 3 of Ishida et al 1971 Feb. 9, would prevent opening and use of the device. In addition, U.S. Pat. No. 3,561,402 to Ishida et al 1971 does not anticipate the important relationship between the sizes of openings into and out of the device and the effective exploratory distance of the animals it is intended to harbor. Furthermore, the devices disclosed in U.S. Pat. No. 3,561,402 to Ishida et al 1971 do not anticipate the importance of thigmotaxis to the attractiveness of such devices to crawling animals as is described in connection with harborages of the present invention. Finally, the devices disclosed in U.S. Pat. No. 3,561,402 to Ishida et al 1971 do not anticipate use for control of crawling animals such as insects and rodents or use as harborages for pet rodents as is described for harborages of the present invention. U.S. Pat. No. 3,864,867 to Dry 1975 Feb. 11 describes a cylindrical pest control device for both roaches and rodents having as many as twenty diamond-shaped openings arranged in three tiers around its circumference. However, the device disclosed in U.S. Pat. No. 3,864,867 to Dry 1975 Feb. 11 was intended only as a holder for poison baits and fumigants and does not envision use of the device as a station for arthropods and rodents. Furthermore, the device disclosed in U.S. Pat. No. 3,864,867 to Dry 1975 Feb. 11 does not envision use of the device as a habitat for rodents. Moreover, unlike harborages of the present invention which offer target animals an array of openings arranged in depth, the device described in U.S. Pat. No. 3,854,867 to Dry 1975 Feb. 11 presents only one layer of openings to the target animals. Furthermore, only certain of the openings in the embodiments described in U.S. Pat. No. 3,864,867 to Dry 1975 Feb. 11 were envisioned as being of a size sufficient to permit an animal standing outside the container to reach a poison bait inside. Moreover, unlike harborages of the present invention which offer target animals an array of openings arranged in depth, the device described in U.S. Pat. No. 3,854,867 to Dry 1975 Feb. 11 presents only one layer of openings to the target animals. U.S. Pat. No. 3,996,348 to Greenberg 1976 Dec. 7 describes a device formed as a flat solid with a porous surface which is not intended to be a harborage for animals, but is instead intended to release a pesticidally effective amount of a gas into the surrounding air. Unlike harborages of the present invention which offer target animals an array of openings arranged in depth, the device described in U.S. Pat. No. 3,996,348 to Greenberg 1976 Dec. 7 presents only one layer of openings to the target animals. Furthermore U.S. Pat. No. 3,996,348 to Greenberg 1976 Dec. 7 does not anticipate any contact between the pores of the device and the target animals, whether as a harborage as is described in devices of the present invention or otherwise. Finally, the device described in U.S. Pat. No. 3,996,348 to Greenberg 1976 Dec. 7 does not allow a target animal which has entered the device to perceive more than one additional orifice as is described in devices of the present invention. U.S. Pat. No. 1,921,945 to Robertson 1933 Aug. 8 describes an irregularly shaped solid body comprised of blast furnace slag and which contains many pores on its surface which are suitable sites for settling of oyster spat. As FIG. 1 of U.S. Pat. No. 1,921,945 to Robertson 1933 Aug. 8 illustrates, the purpose of the pores on the blast furnace slag is to serve as attachment points for the developing oysters which rest on the surface of the slag and do not enter the pores. It will be clear to those skilled in the art of oyster culture that the pores in the slag are not suitable as a harborage for the developing oysters for if the developing larvae were to settle in the pores they would not have sufficient space to grow and reproduce. It is therefore clear that although equipped with surface pores, the slag in U.S. Pat. No. 1,921,945 to Robertson 1933 Aug. 8 is not intended as a harborage for animals and does not anticipate a porous harborage for crawling animals as is described in the present invention. In addition, those skilled in the art of oyster culture will understand that the porous solid described in U.S. Pat. No. 1,921,945 to Robertson 1933 Aug. 8 is not intended to attract crawling animals as are the harborages of the present invention, but is instead intended to retain swimming oyster larvae which settle on it at random after reaching the appropriate stage of morphological development. Furthermore, FIG. 3 of U.S. Pat. No. 1,921,945 to Robertson 1933 Aug. 8 shows that the pores of the blast furnace slag do not connect with each other to form internal cages as is described in harborages of the present invention. Moreover, porous solids of the type described in U.S. Pat. No. 1,921,945 to Robertson 1933 Aug. do not allow target animals to perceive three or more alternative openings after entering the porous solid as is the case in harborages of the present invention. Finally, U.S. Pat. No. 1,921,945 to Robertson 1933 Aug. 8 does not anticipate use of the disclosed device for control of crawling insects and rodents and as an artificial habitat for pet rodents. U.S. Pat. No. 2,340,256 to Weil 1944 Jan. 25 describes an elongate rectangular station with a single opening at each end and containing an interior mass of twisted fibers such as animal fibers, straw and metal shavings which is held within the station by an adhesive. Although U.S. Pat. No. 2,340,256 to Weil 1944 Jan. 25 describes a station which presents multiple openings to animals once they have entered the station, the device described in U.S. Pat. No. 2,340,256 to Weil 1944 Jan. 25 presents only two large external openings to animals inspecting it from outside. In addition, the adhesive used to stabilize the internal fibers described in U.S. Pat. No. 2,340,256 to Weil 1944 Jan. 25 allows the fibers to shift or compress when roaches and other animals walk on them, thereby reducing the stability of the fiber mass and its attractiveness as a harborage. Furthermore, the fiber mass described in U.S. Pat. No. 2,340,256 to Weil 1944 Jan. 25 does not offer exploring animals a series of alternative openings arranged in depth as do harborages of the present invention. Finally, U.S. Pat. No. 2,340,256 to Weil 1944 January 25 does not anticipate use of the disclosed harborage for control of crawling insects and rodents and as an artificial habitat for pet rodents. Soviet patent SU 1,373,383-A to Pacific Fish Industries 1988 Feb. 15 describes a tangled mass of randomly intertwined flat undulating elastic filaments which is intended for use as a substrate for developing prelarvae of salmon and similar fishes. The tangled mass of filaments described in patent SU 1,373,383-A to Pacific Fish Industries 1988 Feb. 15 is not intended to attract free living mobile animals away from competitive environments as is the case with harborages of the present invention but is, instead, intended to retain the developing pre-larvae of fishes which have been deposited into the tangled mass of filaments by their mother or by means of some other agent such as man. In addition, since the mass of filaments described in patent SU 1,375,383-A to Pacific Fish Industries 1988 Feb. 15 is intended for use with fish eggs which lack organs with which to sense the surrounding environment, patent SU 1,375,383-A to Pacific Fish Industries 1988 Feb. 15 fails to anticipate the importance of sensory perception of openings and their sizes and relationships to the effective exploring distances of the target animals as is made apparent in the case of animal harborages of the present invention. Furthermore, the mass of filaments described in patent SU 1,373,383-A to Pacific Fish Industries 1988 Feb. 15 is not intended to retain free living mobile animals within its structure as is the case with harborages of the present invention but is, instead, intended to encourage the developing fish to escape from the mass of filaments back into the outside environment. Moreover, the mass of filaments described in patent SU 1,373,383-A to Pacific Fish Industries 1988 Feb. 15 is intended to move with currents in the water and is not designed to be stable on the substrate as are harborages of the present invention. Those skilled in the biology of crawling animals will appreciate the importance of the stability of a harborage on the substrate to the attractiveness of the harborage to target crawling animals. Furthermore, the mass of filaments described in patent SU 1,373,383-A to Pacific Fish Industries 1988 Feb. 15 is not suitable for use with an adhesive as are animal harborages of the present invention. Those skilled in the art of pest control will appreciate that addition of an adhesive to the flexible mass of filaments described in patent SU 1,373,383-A to Pacific Fish Industries 1988 would stick the filaments together, thereby eliminating the openings and rendering the mass ineffective as a harborage. Finally, patent SU 1,373,383-A to Pacific Fish Industries 1988 Feb. 15 does not anticipate use of the disclosed harborage for control of crawling animals such as insects and rodents and as an artificial habitat for pet rodents. Importance of Harborage Dimensions Many students of insect and rodent behavior and those skilled in the arts of insect and rodent control suspect that there is a relationship between the dimensions of harborages and their effectiveness in attracting and holding various sizes of insects and rodents. For example, it is well known to those skilled in the art of rodent control that rodents prefer to enter harborages with openings approximating the cross sectional diameters of their bodies while preferring to feed within harborages or stations which allow them to sit up while eating. Nevertheless, discussions of preferred harborage dimensions in the prior art have failed to recognize the importance of the dimension of depth as a factor determining the acceptability of a harborage to target animals and have considered only the height and width of the total harborage and the size and shape of only the external openings. Surprisingly, the dimension of depth has been found to be an important contributor to the success of harborages of the present invention. As an example of a discussion of harborage dimensions in the prior art, U.S. Pat. No. 4,395,842 to Margulies 1983 Aug. 2 gives a range of 4 to 10 mm for the height of exterior openings and a range of about 10 to 20 mm for the width of suitable exterior openings. In addition to failing to consider the dimension of depth, studies of harborage dimensions in the prior art have also failed to recognize and appreciate the importance of the distances between both the exterior and interior openings of harborages and the number and arrangement of openings perceived by animals both before entering and after entering harborages. Surprisingly, the closeness of alternative openings and their spatial arrangement both on the exterior and in the interior of harborages have been found to be important contributors to the success of harborages of the present invention. Moreover, discussions of preferred harborage dimensions in the prior art have defined the preferred dimensions of a harborage in absolute terms such as millimeters and have failed to recognize that a better method for determining the preferred dimensions of a harborage is to measure the critical dimensions in relation to the body size of the target animals and to the distances that target animals can explore and perceive before and after entering a harborage. The importance of defining the dimensions of harborages in terms of the body sizes and exploratory capabilities of the target animals has been recognized in the present invention. As an example of a discussion of harborage dimensions in the prior art, U.S. Pat. No. 4,395,842 to Margulies 1983 Aug. 2, American roaches are said to be most likely to enter an opening which is about 19 mm to about 22 mm across whereas German roaches are said to be most likely to enter an opening about 5 mm to about 10 mm across. However, Mizuno and Tsuji 1974 Japanese Journal of Sanitary Zoology Volume 24 Number 3 pages 237-240 report that not all roaches of a given species prefer openings of the same size and that there are, in fact, clear differences between the heights of rectangular harborages preferred by adult roaches as opposed to those preferred by earlier developmental stages of American, German and Japanese roaches. Importance of Effective Exploring Distance It will therefore be clear to those skilled in the art that a comprehensive description of the relationships between body size and optimal harborage dimensions has not yet been developed f or insects, rodents and other crawling animals. Recent reviews in the prior art do not even mention the relationships between the sizes and exploratory abilities of target animals and the dimensions of harborages most suitable for them; particularly the importance of the number, depth and arrangement of openings that can be perceived by the target animals both before and after entering harborages. Surprisingly, the number, depth and arrangement of openings that can be perceived by the target animals both before and after entering harborages have been found to be important to the success of harborages of the present invention. The distance that target animals can explore and perceive before entering and after entering a harborage of the present invention is termed the effective exploring distance. The effective exploring distance as considered in the present invention is important to the success of any animal harborage, including harborages of the present invention. It will be understood by those skilled in the art that effective exploring distance will vary among different types of crawling animals, being different among different species of roaches and other insects, and among different species of mice and other rodents. It will be further understood that effective exploring distance for a given type of animal will also depend upon such factors as the age, size, sex, reproductive condition and the locations and sensitivities of the sensory organs of the target animal. Results obtained with harborages of the present invention show that animals with larger effective exploring distances prefer harborages with greater absolute depths while animals with smaller effective exploring distances prefer harborages with lesser absolute depths. Although the preferred depths are different in the two cases when measured in absolute terms, the preferred depths may be substantially similar when measured in relative terms, for example, in terms of effective exploring distance or body length. Thus, minimally acceptable harborage dimensions for larger animals of the same body type, such as older roaches for example, will be larger than minimally acceptable harborage dimensions for smaller animals of the same body type such as younger roaches. Furthermore, it will be clear to those skilled in the art that a substantially similar relationship will hold between effective exploring distances and the sizes of adult and immature mice and other rodents. Importance of Flexibility In addition to failing to recognize the importance of the preferred depth of an animal harborage and its relationships to animal size, exploring reach and minimal harborage size, studies in the prior art have also failed to recognize the value of a flexible harborage as exemplified in the present invention. The exteriors of harborages described in the prior art are relatively rigid and are not intended to be flexed and formed to fit into irregular spaces and around moving parts of mechanical equipment and the like as is described in the present invention. It is well known to homeowners, pest control operators, farmers and others who use harborages of the prior art that compressing or bending harborages of the prior art will damage them and reduce their effectiveness. Surprisingly, harborages of the present invention retain their effectiveness after being bent and compressed. OBJECTS OF THE INVENTION Accordingly, a primary object of the present invention is to provide an improved harborage that is more attractive to target animals which crawl in search of shelter and more particularly to crawling arthropods such as roaches and other insects and to crawling mammals such as rats, mice and hamsters. Another object is to provide a harborage that is less hazardous to use for control of roaches and the like than are harborages of the known art. Another object is to provide a harborage that is manufactured from natural, biodegradable components. Another object is to provide a harborage that is highly effective for control of insects such as roaches and the like. Another object is to provide a harborage that is highly attractive to young roaches. Another object is to provide a harborage that is less hazardous to use for control of rats and mice and the like than are harborages of the known art. Another object is to provide a harborage that is highly effective for control of rats and mice and the like. Another object is to provide a harborage that is highly effective for control of the endoparasites and ectoparasites of rats and mice and the like. Another object is to provide a harborage that is well accepted as a habitat by rats, mice, hamsters and the like. Another object is to provide a harborage that retains adhesives at an effective degree of tackiness without running or dripping and over a wide range of temperatures and humidities. Another object is to provide a harborage that is highly effective for control of roaches and the like in high temperature environments such as around ovens, furnaces, incinerators and the like. Another object is to provide a harborage that can be used effectively in irregular spaces. Another object is to provide a harborage that can fit snugly into a wide range of openings such as under and around appliances and the like. Another object is to provide a harborage that can be used effectively in contact with moving parts of machinery and equipment. Another object is to provide a harborage that can be expanded into a larger, more complex structure by the addition of modular components. Another object is to provide a harborage that is easy to clean. Another object is to provide a harborage that combats urine and other pet odors. Another object is to provide a harborage which is simple in construction and economical to produce. Further objects and advantages of the present invention will become apparent from a consideration of the ensuing description of it. SUMMARY OF THE INVENTION These and other objects are achieved by the use of porous solids of the present invention as harborages wherein the target animals are continuously confronted by a multiplicity of attractive openings arrayed in three dimensions. This three dimensional array of attractive openings is presented to the target animals in such a way that the animals can perceive at least three sets of openings at increasing distances, thereby increasing the attractiveness of the harborage. Additionally, the arrangement of the openings in the harborage of the present invention makes the harborage more attractive to target animals by providing them with a gradual gradient in critical environmental factors such as light, temperature and humidity. This gradual shift between the less attractive exterior and the more attractive interior helps to draw the animals deeper into the harborage. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a perspective view of a basic version of a terrestrial animal harborage comprised of a porous solid of the present invention. FIG. 2 shows a perspective view of a basic version of the cage, an internal cavity of the terrestrial animal harborage of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS This invention relates to the use of certain porous solids as devices f or attracting animals which crawl in search of shelter and, more particularly, to crawling arthropods such as roaches and other insects and to crawling mammals such as mice, rats and hamsters. The harborage of the present invention is surprisingly attractive and effective despite striking differences in construction from harborages of the prior art. It will be understood from consideration of the previous examples and Figs that a harborage of the present invention of any desired size and shape may be constructed by assembling the required components from the group consisting of web segments 3, webs 1 and cages. It will be further understood that the color, opacity, dimensions, surface features, tensile strength and other physical and chemical properties of a harborage of the present invention and its components may be varied in such a manner as to produce cages of different dimensions and cages and harborages with openings of differing sizes. FIG. 2 is intended for illustrative purposes only and is not intended to limit the number, size and shape of openings 2 which may be included in a cage, the number, size and shape of webs 1, and the number, size and shape of web segments 3. Those skilled in the arts of pest control and pet management will appreciate that a harborage of the present invention can be used in the same fashion as stations, traps and artificial habitats of the prior art. It will be further understood by those skilled in the art that the minimum length and thickness of the webs in a particular embodiment of the present invention will depend upon the physical properties of the web material such as tensile strength, rigidity and the like and the behavioral preferences of the target animals for thickness, surface texture, color, stability and the like of the web material. In a preferred embodiment, a harborage of the present invention comprising a single body contains within itself all of the webs 1 and openings 2 of the harborage. It will be understood that a variety of useful embodiments of the harborage of the present invention may be constructed using a plurality of components such as webs 1, web segments 3, cages and partial cages in various combinations and joined together by suitable means. In another preferred embodiment, a harborage of the present invention comprises a three-dimensional array of openings 2 of a sufficient size, number and arrangement so as to present target animals with a minimum of three openings 2 through which the target animals may attempt to crawl at any time during which they are in contact with the harborage, while both inside the harborage and outside it. The maximum number of openings 2 presented by a harborage of the present invention is defined by the minimum length and thickness of the webs 1 which surround the openings 2 in the harborage, and the effective exploring distance of the target animals. The effective exploring distance as considered in the present invention is important to the success of animal harborages and has not been appreciated by the prior art. It will be understood by those skilled in the art that effective exploring distance varies among different species of roaches, mice and other animals and depends upon such factors as their size, sex, reproductive condition and the locations and sensitivities of their sensory organs. It will be further understood that the preferred dimensions of the cage in harborages of the present invention are likewise defined by the dimensions of the webs and the maximum exploring reach of the target animals. Another preferred embodiment of the present invention comprises a harborage that presents target animals with at least two cages in at least one dimension. Another preferred embodiment comprises a harborage having at least one dimension equal to the effective exploring distance of the target animal. Surprisingly, it has been found in the present invention that an array of openings of differing sizes enhances the attractiveness of harborages to crawling animals, such as insects, rodents and the like. This improvement in acceptability is evidenced by the ability of a single harborage of the present invention constructed with openings of different sizes to attract different sizes of roaches with equal effectiveness. It will be understood from the previous examples that the improved harborage of the present invention may be used alone as a habitat for pet rodents such as rats, mice, hamsters and the like. Surprisingly, harborages constructed according to the present invention are highly attractive to target animals such as roaches, mice, rats, hamsters and the like. Such animals remain inside harborages of the present invention without the use of adhesives, baits or attractants, often turning back when they reach an exit hole and continuing to explore the interior of the harborage. In another preferred embodiment, the harborage of the present invention contains an odorant, odor mask, deodorant or odor neutralizer to combat urine and other pet odors. In another preferred embodiment, the harborage of the present invention comprises an assembly of modular components assembled by appropriate means. Such modular components comprise one or more members of the group consisting of cages, webs and web segments, which components may be disassembled easily to facilitate cleaning of the harborage. It will be understood that the surface of all or part of the harborage of the present invention may be used for the purpose of trapping roaches, rats, mice and the like according to methods familiar to those skilled in the art of pest control. The increased complexity of the interior surface of the harborage of the present invention requires less adhesive than adhesive traps of the known art and reduces leaking and running of adhesives at high temperatures and humidities. In another preferred embodiment, a substantial part of the harborage of the present invention is comprised of one or more different kinds of baits. Rodents have been observed to gnaw the edges of the webs 1 in harborages of the present invention, thereby making all or part of harborages of the present invention surprisingly useful as carriers of baits. In another preferred embodiment, the harborage of the present invention incorporates one or more suitable biologically active agents chosen from the group consisting of insecticides, rodenticides, parasiticides and attractants by processes known to those skilled in the art, including such methods as dusting, dipping and spraying. In another preferred embodiment, the harborage of the present invention is constructed from one or more members of the group of flexible substances including rubber, flexible plastics and the like that are familiar to those skilled in the art. Such a flexible harborage is suitable for fitting snugly under appliances and the like and in contact with moving parts of machinery. In another preferred embodiment, the harborage of the present invention is constructed f rom the group consisting of various reticulated porous ceramics including lithium alumina silicate, mullite and otherwise suitable substances known to those skilled in the art. Such harborages of the present invention are suitable for control of roaches and the like around ovens, furnaces, incinerators and the like. All or part of such harborages may be treated with a heat resistant pesticide such as boric acid by methods known to those skilled in the art. In another embodiment, a harborage of the present invention may be fitted with a lid or bottom with means for attachment to walls, ceilings, underside of shelves and the like. In another preferred embodiment, a harborage of the present invention is combined with a harborage of the known art in such a manner as to allow a rodent station to control cockroaches and to allow a roach station to kill rodents and rodent ectoparasites. In another preferred embodiment, a harborage of the present invention comprises a maze or filter that traps the target animals. In another preferred embodiment, a harborage of the present invention is constructed with openings of a size that excludes larger animals while allowing smaller, younger members of the population of the same species to enter. A harborage of this type can be used to protect the young of pet rodents from predation from larger animals. Similarly a harborage of this type can decrease the time needed to control a pest population by controlling smaller, less dominant individuals which would otherwise not be eliminated until after the larger, more dominant members of the pest population had been removed by bait stations and the like of the prior art. While the above descriptions contain many specificities, these should not be construed as limitations on the scope of the present invention, but rather as exemplifications of several preferred embodiments thereof. Many other variations are possible. The following examples are intended to illustrate, but not limit the present invention. EXAMPLE I In order to demonstrate the effectiveness of a animal harborage of the present invention suitable for use under conditions of high temperature, a rigid, cylindrical harborage of the present invention was constructed by dipping a mullite (Hi-Tech Ceramics Inc. P.O. Box 1105, Alfred, N.Y. 14802) ceramic matrix 76 mm in diameter by 10 mm in thickness in an insecticide solution of 500 parts per million of 1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea (diflubenzuron) insecticide in water. The harborage was then placed in a container with egg cases of German roaches. When the eggs hatched, the young roaches readily entered the harborage. The harborage contained approximately 45 openings per sq cm with an average opening diameter of 1 mm of which openings approximately 30 percent were sufficiently large to allow the roaches to crawl through them, resulting in a total number of useable openings many thousands of times greater than those presented by harborages of the known art. The webs of the harborage were approximately circular in cross section, generally 1 to 2 mm in length and 0.5 to 1 mm in diameter. These web lengths were generally 0.5 to 1.0 body lengths for first instar German roaches. The web diameters were generally 0.25 to 0.5 body lengths for first instar German roaches. The cages of the harborage were roughly spherical and had diameters ranging from about 2 mm to about 8 mm. These diameters are roughly equivalent PG,31 to 1 to 4 body lengths for first instar German roaches. All of the young roaches were killed by the harborage before reaching their second instar. In addition to providing the benefit of effective operation after exposure to high temperatures, the harborage of this embodiment also provides the additional advantages of a harborage that is surprisingly attractive to first instar roaches, a life stage that is not readily attracted to harborages of the prior art. The harborage is also less hazardous than harborages of the known art, is highly effective, is capable of retaining adhesives better than harborages of the prior art, is capable of being used in computers, microwave ovens and other electrical equipment, can be expanded into larger more complex structures by the addition of modular components and is simple in construction and economical to produce. EXAMPLE II In order to demonstrate the effectiveness of a flexible harborage of the present invention, an irregularly shaped, flexible harborage was constructed by treating the interiors of six pieces of polystyrene packing with an insecticide solution of 0.1 percent isopropyl(E,E)-(RS)-11-mehoxy-3,7,11-trimethyldodeca-2,4-dienoate (methoprene) insecticide sterilant and ectoparasiticide, 0.075 percent perchloro-1,1'-bicyclopenta-2,4-diene (dienochlor) miticide, and 0.57 percent (1RS,3RS;1RS,3SR)-2,2-dimethyl-3-(2-methylprop-1-enyl)=cyclopropanecarbozylate (resmethrin) repellent insecticide. The packing pieces were each approximately 50 mm long by 20 mm wide by 3 mm thick and contained two oval orifices approximately 13 mm in maximum diameter. The treated packing pieces were then glued together so as to form a single irregular harborage of the present invention. Twenty untreated packing pieces were then glued to the exterior of the mass of treated pieces to create a larger irregular harborage with an untreated exterior and a insecticidal interior. The larger harborage was readily compressible and resilient, returning to its original form after the pressure was withdrawn. The resilient harborage was then placed in a container with 5 third instar German roaches. The harborage presented 1 opening per 12 to 15 mm resulting in more than 100 openings of a size that could be entered by the roaches. The webs were roughly rectangular in cross section, 3 mm thick and 20 mm long. These web lengths were approximately equal to 2 body lengths for third instar German roaches. The web diameters were approximately equal to 0.3 body lengths for third instar German roaches. The cages of the harborage were roughly spherical and had diameters ranging from about 20 mm to about 40 mm. These diameters are equivalent to about 2 to about 4 body lengths for third instar German roaches. The roaches remained outside the harborage for two weeks during which time the repellent action of resmethrin decreased. The roaches then entered the harborage readily. All of the resulting adult roaches were sterilized by exposure to the harborage. In addition to providing the benefit of a flexible harborage, the harborage of this embodiment was also less hazardous to children and pets than harborages of the known art. Moreover, the harborage was highly effective, capable of being used in irregular spaces, capable of fitting snugly into a wide range of spaces, capable of effective use in contact with moving parts of machinery and equipment, capable of being expanded into larger, more complex structures by the addition of modular components, simple in construction and economical to produce. EXAMPLE III In order to demonstrate the effectiveness of a harborage of the present invention which has been impregnated with an insecticide, 50 rectangular pieces of plastic flea collar approximately 3 mm by 3 mm by 20 mm impregnated with 9.4 percent propoxur insecticide were placed together so as to form a harborage of the present invention having an irregular shape and approximately 40 mm in maximum diameter. Approximately 70 percent of the exterior of the harborage was covered with masking tape which served to hold the plastic pieces in place. There were approximately 4 openings of various sizes per cm on the exterior surf aces of the harborage that were not covered with tape. The sides of the openings were straight, resulting in openings that were shaped like polygons such as triangles, rectangles and the like. The webs were rectangular in cross section, approximately 3 mm wide by 20 mm long by 3 mm deep. These web lengths were approximately equivalent to 10 body lengths for first instar German roaches. The web diameters were approximately 1.5 to 2 body lengths for first instar German roaches. The cages of the harborage were approximately cubical and had diameters of approximately 3 mm. This diameter is approximately equivalent to 1.5 body lengths for first instar German roaches. The harborage contained more than 100 openings of various sizes. The harborage was placed in a container with 5 first instar German roaches. All of the roaches entered the harborage and died within one hour. Two of the roaches died inside the harborage. In addition to providing the benefit of a rapidly acting toxic harborage, the harborage of this embodiment was also highly attractive to young roaches, capable of incorporating a wide variety of biologically active agents, capable of effective use in irregular spaces, capable of use in a wide range of spaces such as under and around appliances, capable of being expanded into larger, more complex structures by the addition of modular components, simple in construction and economical to produce. EXAMPLE IV In order to demonstrate the effectiveness of a harborage of the present invention when constructed of natural, biodegradable materials, a section of dried loofa gourd was cut so as to give a harborage of the present invention of roughly triangular exterior dimensions approximately 25 mm thick and approximately 65 mm in diameter. A globular piece of peanut butter approximately 5 mm in diameter was placed as a bait in the center of the section of loofa gourd. The webs of the harborage were circular to flatly oval in cross section, approximately 3 mm to 30 mm in length and varied from approximately 0.5 to 2.0 mm in diameter. These web lengths were approximately 0.38 to 3.75 body lengths for second instar American roaches and approximately 0.25 to 2.5 body lengths for third instar American roaches. The web diameters were approximately 0.07 to 0.25 body lengths for second instar American roaches and approximately 0.04 to 0.16 body lengths for third instar American roaches. The cages of the harborage were irregular in size and shape. The maximum dimensions of the cages varied widely ranging from approximately 2 mm to approximately 25 mm. These dimensions are equivalent to approximately 0.25 to 3.13 body lengths for second instar American roaches and approximately 0.16 to 2.08 body lengths for third instar American roaches. More than 100 openings of a size suitable for entry were present in the harborage. Five second and third instar American roaches were placed in a container with the harborage. The roaches entered the harborage almost immediately and continued to hide in and explore it for several days, feeding on the peanut butter and climbing through the cages formed by the dried loofa fibers. In addition to providing the benefit of a harborage composed of natural, biodegradable materials, the harborage of this embodiment also provided the additional advantages of increased attractiveness to a variety of sizes of target animals, including young roaches, less hazardous in use than harborages of the known art, and better an more economical retention of adhesives. Furthermore, the harborage capable of effective use in irregular spaces and of fitting snugly into a wide range of openings and was capable of being expanded into a larger structure by the addition of modular components. Moreover, the harborage was simple in construction and economical to produce. EXAMPLE V In order to demonstrate the effectiveness of a harborage of the present invention as an artificial habitat for small rodents, 30 cardboard tubes approximately 2 mm thick, 25 mm in diameter and 20 mm in depth were glued together to produce a roughly rectangular harborage of the present invention. The webs of the harborage were rectangular in cross section, approximately 2 mm thick, and approximately 20 mm long. These web lengths are approximately 0.2 to 0.3 body lengths for an adult house mouse. The web cross sections were approximately 0.02 to 0.03 body lengths for an adult house mouse. The openings were curvilinear portions of circles of various sizes, more than 40 of which exceeded 13 mm inch in minimum diameter and could be entered by an adult house mouse. The cages of the harborage had diameters ranging from about 20 mm to about 80 mm. These diameters are equivalent to about 0.33 to about 0.44 body lengths for an adult house mouse. The harborage was placed in a cage along with a plastic bait station designed for house mice and of a type described in U.S. Pat. No. 4,637,162 to Sherman, 1987 Jan. 20. This particular station is considered by those skilled in the art to be a highly effective bait station. The mouse investigated the openings of the station of the known art but did not enter it. The mouse then investigated the harborage of the present invention, squeezed through one of the initial openings and then began to crawl through the harborage, poking its head out from time to time and then returning to explore the harborage. This behavior continued for more than an hour, after which the mouse began gnawing at the edges of the openings of the harborage of the present invention in an apparent effort to enlarge the cages and improve the suitability of the harborage as a nesting or resting place. In addition to providing the benefit of an effective artificial habitat for small rodents, the harborage of this embodiment also provided the additional advantages of being more attractive to small rodents than harborages of the known art, less hazardous to use than harborages of the known art, highly effective for control of rats and mice, highly effective for control of the ectoparasites and endoparasites of rats and mice, capable of retaining adhesives more effectively than harborages of the known art, capable of effective use in irregular spaces, capable of being expanded into larger more complex structures by the addition of modular components, easy to clean, capable of incorporating agents to combat urine and other pet odors, simple in construction and economical to produce. Other embodiments of the present invention will be apparent to those skilled in the art. Accordingly, the scope of the invention should be determined not by the embodiments described, but by the appended claims and their legal equivalents.

Use of porous solids having a multiplicity of external and internal openings as harborages for crawling animals. The harborages are readily fabricated and are extremely attractive to crawling insects such as cockroaches and ants and to small crawling mammals such as rats, mice and hamsters. The harborages are particularly effective as traps for the control of insect and rodent pests and as habitats for pet rodents.

TECHNICAL FIELD This invention relates to dye-donor elements used in thermal dye transfer, and more particularly to the use of a certain subbing layer between a polymeric support and a dye layer comprising a dye dispersed in a binder. BACKGROUND OF THE INVENTION In recent years, thermal transfer systems have been developed to obtain prints from a color video camera. According to one way of obtaining such prints, an electronic picture is first subjected to color separation by color filters. The respective color-separated images are then converted into electrical signals. These signals are then operated on to produce cyan, magenta and yellow electrical signals Then the signals are transmitted to a thermal printer. To obtain the print, a cyan, magenta and yellow dye-donor element is placed face-to-face with a dye receiving element. The two are then inserted between a thermal printing head and a platen roll. A line-type thermal printing head is used to apply heat from the back of the dye-donor sheet. The thermal printing head has many heating elements and is heated up sequentially in response to the cyan, magenta and yellow signals. The process is then repeated for the other two colors. Further details of this process and an apparatus for carrying it out are contained in U.S. Pat. No. 4,621,271 by Brownstein entitled "Apparatus and Method For Controlling A Thermal Printer Apparatus," issued Nov. 4, 1986, the disclosure of which is hereby incorporated by reference. Titanium alkoxides (such as Tyzor TBT® (titanium tetra-n-butoxide of duPont)) have been used as subbing layers between a polyester support and a dye-layer. While these materials are excellent subbing layers for adhesion purposes, problems have arisen with hydrolytic instability and they are difficult to coat in a reproducible manner. It has also been observed that degradation of dyes in the dye-donor can occur when titanium alkoxides are used as a subbing layer. This problem is particularly prevalent with arylidene pyrazolone yellow dyes. The subbing layers of the prior art may also have problems in that when a thin layer of polyester support is used for the dye-donor there is a greater tendency for layer delamination, particularly when multiple prints are attempted from a single donor. U.S. Pat. No. 4,695,288 is directed to a dye-donor element for thermal dye transfer comprising a subbing layer comprising recurring units of an ethylenically unsatuated monomer and recurring units of an ethylenicaly unsatuated carboxylic acid. SUMMARY OF THE INVENTION It is therefore an object of this invention to provide a subbing layer for a dye-donor element that greatly reduces the tendency for dye layer delamination. Another object of the invention is to provide a dye-donor element having a subbing layer that improves dye layer stability. Accordingly, for accomplishing these and other objects of the invention, there is provided a dye donor element for thermal dye transfer comprising a polymeric support having thereon, in order, a subbing layer and a dye layer comprising a dye dispersed in a binder, and wherein the subbing layer comprises a copolymer having a glass transition temperature below 50° C., comprising recurring monomer units derived from at least one linear vinyl copolymer comprising: ##STR2## wherein: each R 1 is, independently, H or methyl; R 2 and R 3 each, independently, represents a substituted or unsubstituted alkyl group of 1 to 6 carbon atoms, such as, methyl, ethyl, propyl, butyl or hexyl, or a substituted or unsubstituted cycloalkyl group of 5 to 8 carbon atoms, such as cylcohexyl; R 4 represents: a) a substituted or unsubstituted alkyl group of 2 to 4 carbon atoms substituted with at least 1 hydroxyl group; or b) from 2 to about 20 ethoxy groups substituted with at least 1 hydroxyl group; R 5 represents a substituted or unsubstituted alkyl group of 1 to 12 carbon atoms, such as, methyl, ethyl, propyl, butyl, hexyl, lauryl, or 2-ethylhexyl, or a substituted or unsubstituted cycloalkyl group of 5 to 8 carbon atoms, such as cyclohexyl; w represents 5 to 50 weight-percent; x represents 0 to 40 weight-percent; and y represents 50 to 95 weight-percent. DETAILED DESCRIPTION OF THE INVENTION In a preferred embodiment of the invention, the copolymer comprises recurring units of: monomer J wherein R 1 is hydrogen and R 2 and R 3 are each methyl; monomer B wherein R 1 is methyl and R 4 is 2-hydroxyethyl; and, monomer D wherein R 1 is hydrogen and R 5 is butyl. In another preferred embodiment, the glass transition temperature of the copolymer is 20° C. In still another preferred embodiment, the concentration of both monomers J and B in the copolymer is 25 weight-percent. In another preferred embodiment, the copolymer comprises monomer J, wherein R 1 is hydrogen, R 2 and R 3 both methyl, present in the copolymer at about 25 weight-percent; and, monomer D, wherein R 1 is hydrogen and R 5 is butyl, present at about 75 weight-percent. The glass transition temperature of this copolymer is -10° C. The copolymer may also be described as J n D 100-n . Although these two monomers are required, the inclusion of one or more other monomeric units, such as B monomer, is permitted provided they do not alter the essential properties of the copolymer. The copolymer J n D 100-n is such that n is 5 to 40 weight-percent, preferably 20 to 30 weight percent. The balance of the copolymer represented by D alone or D with one or more other copolymerizable monomers is present in the copolymer in an amount representing the difference from the J component. The copolymer J n D 100-n of the present invention may be used alone as the subbing layer or may be used in combination with a Group IVA or IVA metal alkoxide or an acid or amine cross-linking catalyst such as p-toluene sulfonic acid or propanediamine. Two particularily favored B-monomers for copolymerization with the J-monomer are 2-hydroxyethyl methacrylate and 2-hydroxyethyl acrylate. The following copolymers are included within the scope of the invention: J is the methyl 2-acrylamido-2-methoxy acetate component: ##STR3## The subbing layer of the invention may be employed at any concentration which is effective for the intended purpose. In general, good results have been obtained at about 0.01 to 0.3 g/m 2 total coverage of composite, preferably 0.02 to 0.1 g/m 2 . Any polymeric binder may be employed in the dye donor element of the invention. In a preferred embodiment, the binder contains hydroxyl, amino, thio, amido, and/or carboxyl groups. For example there may be employed cellulosic binders, such as cellulose acetate, cellulose triacetate (fully acetylated) or a cellulose mixed ester such as cellulose acetate butyrate, cellulose acetate hydrogen phthalate, cellulose acetate formate, cellulose acetate propionate, cellulose acetate pentanoate, cellulose acetate hexanoate, cellulose acetate heptanoate, or cellulose acetate benzoate. The polymeric binder in the dye-donor element of the invention may be employed at any concentration which is effective for the intended purpose. In general, good results have been obtained at about 0.05 to about 5 g/m 2 of coated element. Any polymeric material can be used as the support for the dye-donor element of the invention provided it is dimensionally stable and can withstand the heat of the thermal printing head. Such materials include polyesters such as poly(ethylene terephthalate); polyamides; polycarbonates; cellulose esters such as cellulose acetate; fluorine polymers such as polyvinylidene fluoride or poly(tetrafluoroethylene-co-hexafluoropropylene); polyethers such as polyoxymethylene; polyacetals; polyolefins such as polystyrene, polyethylene, polypropylene or methylpentene polymers; and polyimides such as polyimide-amides and polyether-imides. The support generally has a thickness from about 5 to about 30 mm. Any dye can be used in the dye layer of the dye-donor element of the invention provided it is transferable to the dye-receiving layer by the action of heat. Especially good results have been obtained with sublimable dyes such as anthraquinone dyes, e.g., Sumikalon Violet RS® (product of Sumitomo Chemical Co., Ltd.), Dianix Fast Violet 3R-FS® (product of Mitsubishi Chemical Industries, Ltd.), and Kayalon Polyol Brilliant Blue N-BGM® and KST Black 146® (products of Nippon Kayaku Co., Ltd.); azo dyes such as Kayalon Polyol Brilliant Blue BM®, Kayalon Polyol Dark Blue 2BM®, and KST Black KR® (products of Nippon Kayaku Co., Ltd.), Sumickaron Diazo Black 5G® (product of Sumitomo Chemical Co., Ltd.), and Miktazol Black 5GH® (product of Mitsui Toatsu Chemicals, Inc.); direct dyes such as Direct Dark Green B® (product of Mitsubishi Chemical Industries, Ltd.) and Direct Brown M® and Direct Fast Black D® (products of Nippon Kayaku Co. Ltd.); acid dyes such as Kayanol Milling Cyanine 5R® (product of Nippon Kayaku Co. Ltd.); basic dyes such as Sumicacryl Blue 6G® (product of Sumitomo Chemical Co., Ltd.), and Aizen Malachite Green® (product of Hodogaya Chemical Co., Ltd.); ##STR4## or any of the dyes disclosed in U.S. Pat. Nos. 4,541,830; 4,698,651; 4,695,287; 4,701,439; 4,757,046; 4,743,582; 4,769,360; and 4,753,922; the disclosures of which are hereby incorporated by reference. The above dyes may be employed singly or in combination. The dyes may be used at a coverage of from about 0.05 to about 1 g/m 2 and are preferably hydrophobic. The reverse side of the dye-donor element may be coated with a slipping layer to prevent the printing head from sticking to the dye-donor element. Such a slipping layer would comprise either a solid or liquid lubricating material or mixtures thereof, with or without a polymeric binder or a surface active agent. Preferred lubricating materials include oils or semi-crystalline organic solids that melt below 100° C. such as poly(vinyl stearate), beeswax, perfluorinated alkyl ester polyethers, poly(capro-lactone), silicone oil, poly(tetrafluoroethylene), carbowax®, poly(ethylene glycols), or any of those materials disclosed in U.S. Pat. Nos. 4,717,711; 4,717,712; 4,737,485; and 4,738,950. Suitable polymeric binders for the slipping layer include poly(vinyl alcohol-co-butyral), poly(vinyl alcohol-co-acetal), poly(styrene), poly(vinyl acetate), cellulose acetate butyrate, cellulose acetate propionate, cellulose acetate or ethyl cellulose. The amount of the lubricating material to be used in the slipping layer depends largely on the type of lubricating material, but is generally in the range of about 0.001 to about 2 g/m 2 . If a polymeric binder is employed, the lubricating material is present in the range of 0.1 to 50 weight-percent, preferably 0.5 to 40, of the polymeric binder employed. The dye-receiving element that is used with the dye-donor element of the invention usually comprises a support having thereon a dye image-receiving layer. The support may be a transparent film such as a poly(ether sulfone), a polyimide, a cellulose ester such as cellulose acetate, a poly(vinyl alcohol-co-acetal) or a poly(ethylene terephthalate). The support for the dye-receiving element may also be reflective such as baryta-coated paper, polyethylene-coated paper, an ivory paper, a condenser paper or a synthetic paper such as duPont Tyvek®. Pigmented supports such as white polyester (transparent polyester with white pigment incorporated therein) may also be used. The dye image-receiving layer may comprise, for example, a polycarbonate, a polyurethane, a polyester, polyvinyl chloride, poly(styrene-co-acrylonitrile), poly(caprolactone), a poly(vinyl acetal) such as poly(vinyl alcohol-co-butyral), poly(vinyl alcohol-co-benzal), poly(vinyl alcohol-co-acetal) or mixtures thereof. The dye image-receiving layer may be present in any amount which is effective for the intended purpose. In general, good results have been obtained at a concentration of from 1 to about 5 g/m 2 . As noted above, the dye-donor elements of the invention are used to form a dye transfer image. Such a process comprises imagewise-heating a dye-donor element as described above and transferring a dye image to a dye-receiving element to form the dye transfer image. The dye-donor element of the invention may be used in sheet form or in a continuous roll or ribbon. If a continuous roll or ribbon is employed, it may have alternating areas of other different dyes or combinations, such as sublimable cyan and/or yellow and/or magenta and/or black or other dyes. Such dyes are disclosed in U.S. Pat. No. 4,541,830, the disclosure of which is hereby incorporated by reference. Thus, one-, two-, three- or four-color elements (or higher numbers also) are included within the scope of the invention. Thermal printing heads which can be used to transfer dye from the dye-donor elements of the invention are available commercially. There can be employed, for example, a Fujitsu Thermal Head (FTP-040 MCSOO1), a TDK Thermal Head F415 HH7-1089 or a Rohm Thermal Head KE 2008-F3. A thermal dye transfer assemblage of the invention comprises a) a dye-donor element as described above, and b) a dye-receiving element as described above, the dye-receiving element being in a superposed relationship with the dye-donor element so that the dye layer of the donor element is in contact with the dye image-receiving layer of the receiving element. The above assemblage comprising these two elements may be preassembled as an integral unit when a monochrome image is to be obtained. This may be done by temporarily adhering the two elements together at their margins. After transfer, the dye-receiving element is then peeled apart to reveal the dye transfer image. When a three-color image is to be obtained, the above assemblage is formed three times using different dye-donor elements. After the first dye is transferred, the elements are peeled apart. A second dye-donor element (or another area of the donor element with a different dye area) is then brought in register with the dye-receiving element and the process repeated. The third color is obtained in the same manner. The invention will be further clarified by a consideration of the following examples, which are intended to be purely exemplary of the use of the invention. EXAMPLE 1 Yellow dye-donor elements were prepared by coating the following layers in order on a 6 micron poly(ethylene terephthalate) support. 1) subbing layer as specified (0.11 g/m 2 )of the indicated copolymer indicated below and illustrated above from methanol. 2) Dye layer containing the yellow dye identified below (0.15 g/m 2 ), and cellulose acetate propionate binder (2.5% acetyl and 45% propionyl) (0.37 g/m 2 ) coated from a toluene, methanol and cyclopentanone solvent mixture (65/30/5). ##STR5## On the backside of the dye-donor element was coated: a slipping-layer of Emralon 329 polytetrafluoroethylene dry film lubricant (Acheson Colloids) (0.54 g/m 2 ) from a n-propyl acetate, toluene, and methanol solvent mixture. Control dye-donors were prepared as described above except a different subbing layer (at 0.11 g/m 2 ) was coated underneath the dye layer: ##STR6## The following comparison polymers all involve methyl 2-acrylamido-2-methoxy acetate, J, as a monomer, but are outside the definition of the invention, primarily because of high T g (all ratios are weight ratios) ##STR7## All dye-donor coatings including those with the control subbing layers were dried at 40° C. for 50 sec and then 65° C. for 200 sec to insure crosslinking of the polymer. A dye-receiving element was prepared by coating the following layers in the order recited over a white reflective support of titanium dioxide-pigmented polyethylene overcoated paper stock: 1) a subbing layer of poly(acrylonitrile-co-vinylidene chloride-co-acrylic acid) (14:79:7 wt. ratio) (0.08 g/m 2 ) coated from butanone; 2) a dye-receiving layer of Makrolon 5700, a bisphenol A-polycarbonate resin (Bayer AG) (2.9 g/m 2 ), Tone PCL-300 polycaprolactone (Union Carbide) (0.38 g/m 2 ), and 1,4-didecoxy-2, 6-dimethoxyphenol (0.38 g/m 2 ) coated from methylene chloride; and 3) overcoat layer of Tone PCL-300 polycaprolactone (Union Carbide) (0.11 g/m 2 ), FC-431 fluorocarbon surfactant (3M Corp.) (0.011 g/m 2 ) and DC-510 Silicone Fluid (Dow Corning) (0.01 g/m 2 ) coated from methylene chloride. The dye-side of a dye-donor element strip approximately 10 cm×13 cm in area was place in contact with the image-receiver layer side of a dye-receiver element of the same area. This assemblage was clamped to a stepper-motor driven 60 mm diameter rubber roller. A TDK Thermal Head L-231 (thermostated at 23.5° C.) was pressed with a spring at a force of 36N against the dye-donor element side of the assemblage pushing it against the rubber roller. The imaging electronics were activated causing the donor-receiver assemblage to be drawn through the printing head/roller nip at 6.9 mm/sec. Coincidentally the resistive elements in the thermal print head were pulsed for 20 μsec/pulse at 128 μsec intervals during the 33 msec/dot printing time. A stepped density image as generated by incrementally increasing the number of pulses/dot from 0 to 255. The voltage supplied to the printing head was approximately 24.5 volts, resulting in an instantaneous peak power of 1.4 watts/dot and maximum total energy of 10.5 mJoules/dot. The Status A Blue maximum density of each of the stepped images was read and recorded. Using the same area of receiver, a stepped image using an unused yellow dye donor area was recorded on top of the first stepped image. Note was made of any sticking when the donor was separated from the receiver. This was repeated for up to twelve or more printings of dye-donor onto the same receiver. Sticking of the donor to the receiver, and retention of part or all of the donor dye layer on the receiver indicated a poor adhesion and weak bond for the subbing layer. The number of transfers that could be made to the receiver before sticking occurred was also recorded as "prints to fail". To evaluate dye stability of the dye-donor, the Status A Blue transmission density of the dye-donor was read as coated and again after incubation for one week in the dark at 49° C. and 50% RH. The percent decrease in density was calculated as indicative of dye loss. The following results were obtained: TABLE 1______________________________________ Maximum IncubationSUBBING LAYER Density Status Prints Dye LossCopolymer T.sub.g A Blue to Fail (Percent)______________________________________E-1 20° C. 2.8 >12 4 E-1* 20° C. 2.5 >12 <4E-2 1° C. 2.6 >12 <4E-3 -17° C. 2.5 >12 <4E-4 15° C. 2.6 >12 <4E-5 -10° C. 2.5 >12 <4E-6 -5° C. 2.6 >12 <5C-1 (none) 2.5 3 <4C-2 (control) (See U.S. 2.6 >12 18Pat. No. 4,737,486)C-3 (control) 2.6 4 46C-4 (control) (See U.S. 2.4 >12 66Pat. No. 4,700,208)C-5 (control) 2.3 1 <4C-6 (comparison) 2.5 1 <4Tg = 124° C.C-7 (comparison) 2.5 3 <4Tg = 124° C.C-8 (comparison) 2.8 4 <4Tg = 88° C.C-9 (comparison) 2.5 3 <4Tg = 70° C.______________________________________ *This is the same polymer as E1 (0.11 g/m.sup.2), but also contained 10 weight percent Tyzor TBT ®. The results show that the subbing layer of the invention coated between the support and dye layer provide both improved adhesion (greater number of prints before separation failure) and less loss of dye due to decomposition within the dye-donor itself than the control subbing layers of the titanium alkoxide or a prior art poly(alkyl acrylate ester). Dye donors with polymers above T g 50° C. either gave low transferred dye density or low number of repeat prints before separation failure. EXAMPLE 2 This example is similar to Example 1 but shows the effectiveness of the subbing layer is maintained at different coverages of the copolymers of the invention. Dye donor elements were prepared as in Example 1. Dye receiver elements were prepared as in Example 1. Data for maximum transferred density, repeat printing sticking, and dye-density loss of the donor were evaluated as in Example 1. The following results were obtained: TABLE 2______________________________________ Sub Layer Maximum Incubation Coverage Density Status Prints Dye LossCopolymer (g/m.sup.2) A Blue to Fail (Percent)______________________________________E-1 0.054 2.9 3 <4E-1 0.011 2.9 5 <4E-1 0.022 2.9 6 <4E-1 0.054 2.9,2.8 >12 <4E-1 0.11 2.8,2.8 >12 <4,9E-1 0.22 2.7 >12 <4E-6 0.054 2.8 >12 <4E-6 0.11 2.7 >12 <4E-6 0.22 2.7 >12 <4E-7 0.01 2.5 >12 <4E-8 0.01 2.8 >12 <4______________________________________ The above illustrates the invention at different polymer coverages. The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

Dye donor elements and assemblages for thermal dye transfer processing comprising a polymeric support having thereon, in order, a subbing layer and a dye layer comprising a dye dispersed in a binder, and wherein the subbing layer comprises a copolymer having recurring monomer units derived from at least one linear vinyl copolymer comprising: ##STR1## wherein: each R 1 is, independently, H or methyl; R 2 and R 3 each, independently, represents: a) a substituted or unsubstituted alkyl group of 1 to 6 carbon atoms; or b) a substituted or unsubstituted cycloalkyl group of 5 to 8 carbon atoms; R 4 represents: a) a substituted or unsubstituted alkyl group of 2 to 4 carbon atoms substituted with at least 1 hydroxyl group; or b) from 2 to about 20 ethoxy groups substituted with at least 1 hydroxyl group; R 5 represents: a) a substituted or unsubstituted alkyl group of 1 to 12 carbon atoms; or b) a substituted or unsubstituted cycloalkyl group of 5 to 8 carbon atoms; w represents 5 to 50 weight-percent; x represents 0 to 40 weight-percent; and y represents 50 to 95 weight-percent.

RELATED APPLICATION [0001] This application is a nonprovisional and claims the benefit of priority of U.S. Provisional Application No. 62/107,690, filed Jan. 26, 2015. FIELD OF THE INVENTION [0002] This invention relates therapeutic wraps, and, more particularly, to a wrap that contains an integral thermal media array and supports transcutaneous electrical nerve stimulation. BACKGROUND [0003] Transcutaneous electrical nerve stimulation (TENS) uses electrical stimuli to stimulate nerves for therapeutic purposes. A TENS unit connects to the skin using two or more electrodes. A typical battery-operated TENS unit is able to modulate pulse width, frequency and intensity of the electrical energy supplied through the electrodes. The electrodes usually consist of a conducting gel, which may be adhesive or coated with an adhesive. A cable or lead extends from the TENS unit to each electrode. The electrodes deliver the electrical stimulus. [0004] Heating and cooling are useful for relieving sore aching muscles and post surgical treatment. Cooling and heating wraps typically consist of a garment with pockets that contain a bulky sack containing a liquid or gel cooling or heating substance. When frozen, the sack forms a solid brick-like mass. [0005] As both TENS and thermal therapy may benefit the same parts of the body, it is desirable to have a device that supports both and delivers electrical stimulation with heating or cooling. Unfortunately, units developed heretofore utilize bulky thermal media sacks that tend to interfere with placement and adherence of TENS electrodes. What is needed is a wrap with an integral thermal media that distributes weight and maintains its form throughout the thermal therapy, while allowing attachment of TENS electrodes and a coupled TENS unit. [0006] The invention is directed to overcoming one or more of the problems and solving one or more of the needs as set forth above. SUMMARY OF THE INVENTION [0007] To solve one or more of the problems set forth above, in an exemplary implementation of the invention, a wrap includes an integral thermal media array and supports transcutaneous electrical nerve stimulation. The wrap has a thermal media laminate containing an array of spaced apart cells of thermal media sandwiched between a plastic film and fabric. The cellular laminate is flexible, foldable and wrappable. Areas in the laminate are provided for attaching electrodes. The laminate is attached to a backing. Apertures in the laminate and backing allow passage of wire leads from the electrodes. Elastic bands with hook fasteners extend from the backing. The hook fasteners releasably attach to loop material of the backing. A TENS unit clips onto one or more of the bands. The leads attach to the TENS unit. [0008] In one embodiment, a wearable nerve-stimulating thermal wrap according to principles of the invention includes a thermal media laminate comprised of a web of plastic film sealed at a plurality of locations to a web of fabric with spaces between the sealed locations comprising cells. Each cell is a pocket surrounded by locations at which the plastic film is sealed to the web of fabric. Each cell contains an absorbent solid state thermal medium. The thermal media laminate further comprises at least one electrode area, each electrode area being devoid of cells and being sized and shaped to receive a transcutaneous electrical nerve stimulation electrode. An insulating backing is attached to the plastic film opposite the web of fabric. A transcutaneous electrical nerve stimulation electrode is attached to at least one electrode area. A wire lead extends from the transcutaneous electrical nerve stimulation electrode. A first aperture is provided in the thermal media laminate at one of the locations at which the plastic film is sealed to the web of fabric adjacent to one of the at least one electrode area. A second aperture is provided in the insulating backing in alignment with the first aperture. The wire lead of the transcutaneous electrical nerve stimulation electrode extends through the first aperture and the second aperture. An attachment band is attached to the thermal media laminate. The attachment band is sized to releasably secure the thermal media laminate to a wearer. A transcutaneous electrical nerve stimulation unit is operably coupled to the wire lead of the transcutaneous electrical nerve stimulation electrode. The at least one electrode area may comprise a fenestration in the thermal media laminate. The absorbent solid state thermal medium may comprise a superabsorbent, multiply-cross-linked polymer. BRIEF DESCRIPTION OF THE DRAWINGS [0009] The foregoing and other aspects, objects, features and advantages of the invention will become better understood with reference to the following description, appended claims, and accompanying drawings, where: [0010] FIG. 1 is a plan view of an exemplary thermal media laminate for use with a wrap according to principles of the invention; and [0011] FIG. 2 is a perspective view of an exemplary thermal media laminate for use with a wrap according to principles of the invention; and [0012] FIG. 3 is a plan view of an exemplary thermal media laminate equipped with electrodes for use with a wrap according to principles of the invention; and [0013] FIG. 4 is a perspective view of an exemplary thermal media laminate equipped with electrodes for use with a wrap according to principles of the invention; and [0014] FIG. 5 is a plan view of an exemplary wrap according to principles of the invention; and [0015] FIG. 6 is a perspective view of an exemplary wrap according to principles of the invention; and [0016] FIG. 7 is a bottom view of an exemplary wrap according to principles of the invention; and [0017] FIG. 8 is a bottom perspective view of an exemplary wrap according to principles of the invention; and [0018] FIG. 9 is a side view of an exemplary wrap, wrapped around a wearer's limb, according to principles of the invention. [0019] Those skilled in the art will appreciate that the figures are not intended to be drawn to any particular scale; nor are the figures intended to illustrate every embodiment of the invention. The invention is not limited to the exemplary embodiments depicted in the figures or the specific components, configurations, shapes, relative sizes, ornamental aspects or proportions as shown in the figures. DETAILED DESCRIPTION [0020] Referring to FIGS. 1 through 4 , various views of an exemplary thermal media laminate 100 for use with a wrap according to principles of the invention is provided. The laminate 100 consists of a web of plastic film (e.g., an impervious plastic sheet such as a polyester film) sealed to a web of non-woven fabric (e.g., a non-woven porous polypropylene) at parallel and perpendicular strips, thus forming a grid of, for example, two inch by two inch (2″×2″) cells 125 - 160 or pockets across the web. The cellular arrangement facilitates bending and wrapping. Sealing may be performed using a tacky, sealant or adhesive layer (e.g., ethylene-methyl-acrylate (EMA)), or using a heat sealing tape, or other suitable sealants for merging plastic and fabric. A small volume of a solid state thermal medium, such as a superabsorbent, multiply-cross-linked polymer is provided within each such cell. The solid thermal medium is adhesively fixed to areas of the plastic film destined to comprise cells 125 - 160 . Each cell resembles a thin pillow when dehydrated and a puffy pillow when hydrated. The sealed strips 185 not only define the peripheries of the laminate 100 and each cell, but also provide substantially flat areas suitable for stitching the laminate 100 to a cover, as discussed below. [0021] The laminate 100 also includes an area (“electrode area”) for mounting each of a plurality of electrodes 205 - 220 . Each such electrode area 105 - 120 may comprise a fenestration (e.g., a cutout or window) or a planar area without any thermal medium. Each electrode area 105 - 120 is sized and shaped to receive a TENS electrode 205 - 220 , and positioned to locate each electrode 205 - 220 in a desired position on a wearer's body when the wrap is worn and used. The number and position of electrodes may vary without departing from the scope of the invention. The wrap may be used with and without electrodes, in accordance with the invention. [0022] Passages 165 - 180 for wire leads 265 - 280 from the electrodes 205 - 220 are also provided in the laminate 100 . By way of example and not limitation, a passage may be provided in a sealed strip 185 adjacent to an electrode area 105 - 120 . In the figures, grommets define the passages. Wires 265 - 280 extending from the electrodes 205 - 220 pass through these grommets and corresponding apertures. As the electrodes 205 - 220 are replaceable, the passages 165 - 180 allow withdrawal of the received wires 265 - 280 . Thus, the passages 165 - 180 are sized and positioned to allow passage of the electrode wires 265 - 280 . [0023] Referring now to FIGS. 5 through 8 , the laminate 100 of the wrap 300 is attached to a backing 305 305 . The backing 305 provides an insulating and protective cover. It also facilitates attaching the wrap. The backing 305 may comprise neoprene laminated with a nylon low pile soft loop fabric, which is compatible with hook fasteners. The plastic side of the laminate 100 abuts the neoprene backing 305 . The loop fabric side of the neoprene, which provides a surface for attachment of hook elements of a hook and loop fastener, faces away from the laminate 100 . The fabric side of the laminate 100 , which will abut a wearer, faces away from the backing 305 . The laminate 100 may be attached to the backing 305 by stitching and/or bonding. In a preferred embodiment, the laminate 100 is stitched to the backing 305 , with stitching along the sealed strips 185 . [0024] The backing 305 includes a plurality of apertures aligned with the apertures and grommets of the laminate 100 . The wire leads 265 - 280 of the electrodes 205 - 220 extend through the apertures of the backing 305 . [0025] A plurality of elastic bands 310 - 320 extend from an edge of the backing 305 . The side of each band 310 - 320 facing the laminate 100 includes hook elements 325 - 350 of a hook and loop fastener. When the wrap 300 is wrapped around a limb, the hook elements 325 - 340 are attachable to the loop fabric side of the neoprene backing 305 . Elasticity of the bands 310 - 320 allows considerable adaptation for attachment to various body parts. The plurality of elastic bands 310 - 320 do not have to extend from the same edge. One or more bands 310 - 320 may extend from an edge that is orthogonal to or opposite from an edge from which one or more other bands 310 - 320 extend. [0026] A TENS unit 400 attaches to one or more bands 310 - 320 . The back of most commercially available TENS units is equipped with a clip 405 for attachment to a belt. The bands 310 - 320 are sufficiently wide and supportive to securely hold the TENS unit. The wire leads 265 - 280 of the electrodes 205 - 220 extend through the apertures in the laminate 100 and backing 305 and connect to the TENS unit 400 . [0027] To prepare the wrap 300 for use, the electrodes are removed from the wrap. Then the laminate 100 is hydrated using water. Tap water at room temperature works well. The polymer media contained in the laminate 100 absorbs the water and expands. After a few minutes of hydration, the hydrated wrap 300 is frozen in a freezer or heated in a microwave. Then the electrodes are installed, with leads extending through the laminate 100 and backing 305 to the TENS unit 400 . Then the wrap 300 is wrapped around a user's limb or other body part to be treated. The TENS unit 400 is clipped to one or more bands 310 - 320 , as conceptually illustrated in FIG. 9 . Then the TENS unit 400 is activated for a session, during which the treated area simultaneously receives electrical stimulation and thermal therapy. Of course, the TENS unit 400 and electrodes may be used without hydrating and/or freezing or heating the laminate 100 . Likewise, the frozen or heated laminate 100 may be used without the TENS unit 400 . However, used together, the thermal media and electrical stimulus are believed to provide a superior therapy session. [0028] While an exemplary embodiment of the invention has been described, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. With respect to the above description then, it is to be realized that the optimum relationships for the components and steps of the invention, including variations in order, form, content, function and manner of operation, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. The above description and drawings are illustrative of modifications that can be made without departing from the present invention, the scope of which is to be limited only by the following claims. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents are intended to fall within the scope of the invention as claimed.

A wrap has a thermal media laminate containing an array of spaced apart cells of thermal media sandwiched between a plastic film and fabric. Areas in the laminate are provided for attaching electrodes. The laminate is attached to a backing. Apertures in the laminate and backing allow passage of wire leads from the electrodes. Elastic bands with hook fasteners extend from the backing. The hook fasteners releasably attach to loop material of the backing. A TENS unit clips onto one or more of the bands. The leads attach to the TENS unit.

FIELD OF THE INVENTION [0001] The present invention is in the field of Chemical Vapor Deposition (CVD), including Plasma Enhanced Chemical Vapor Deposition (PECVD) and related processes ,and pertains more particularly to methods and apparatus for controlling flux uniformity for gas delivery. BACKGROUND OF THE INVENTION [0002] In the field of Thin Film Technology, used extensively in manufacture of integrated circuits, requirements for thinner deposition layers, better uniformity over larger surfaces, and larger production yields have been, and are, driving forces behind emerging technologies developed by equipment manufactures. As semiconductor devices become smaller and faster, the need for greater uniformity and process control in layer thickness, uniformity, resistivity and other film properties rises dramatically. [0003] Various technologies are well known in the art for applying thin films to substrates in manufacturing steps for integrated circuits (ICs). Among the more established technologies available for applying thin films is Chemical Vapor Deposition (CVD), which includes Plasma Enhanced Chemical Vapor Deposition (PECVD). These are flux-dependent applications requiring specific and uniform substrate temperature and precursors (chemical species) to be in a state of uniformity in the process chamber in order to produce a desired film properties on a substrate surface. These requirements become more critical as substrate size increases, and as device size decreases (i.e. line width) creating a need for more complexity in chamber design and gas flow techniques to maintain adequate uniformity. [0004] CVD systems use a variety of known apparatus for delivering precursor gases to target substrates. Generally speaking, gas delivery schemes for CVD and PECVD processes are designed specifically for one particular application and substrate size. Therefore variations in theme of such delivery apparatus and methods will depend on the particular process parameters and size of substrates being processed in a single reactor. Prior art gas manifolds and diffusers have been manufactured from a variety of materials and are widely varied in design. For example, some gas delivery manifolds are long tubes that are either straight or helical with a plurality of small, often differently sized, gas delivery holes spaced longitudinally along the manifold. Most diffusers and showerheads are basically baffle-type structures having a plurality of holes placed in circular or spiral type arrangements on opposite facing plates or surfaces. Often the holes are contained in a series of expanding radii circles on each plate. Often such apparatus is adapted only for one type of process and cannot be used with other processes using the same CVD equipment. [0005] One characteristic that is generally required in CVD gas delivery apparatus is that hole sizes and spacing between the holes is strictly controlled such that a uniform gas distribution or zone is maintained over a particular surface area. Uneven gas flow often results if some holes are inadvertently made too large in comparison with a mean size, or placed in wrong positions. If a larger substrate is used in a same or different chamber, then the gas delivery apparatus must often be exchanged for one that is designed and adapted for the variance in substrate size and/or chamber parameters. Improvements made to manifold and diffuser designs depend largely on empirical methods in the field resulting in numerous cases of product expenditure through batch testing. [0006] Uniform gas delivery remains a formidable challenge in the CVD processing of substrates. If gas delivery uniformity cannot be strictly controlled, layer thickness will not be uniform. The problem progresses with increased target size and as more layers are added. Moreover, many substrates to be coated already have a complex topology introducing a requirement for uniform step coverage. PECVD in many cases has advantages over CVD in step coverage by virtue of delivering more reactive chemical precursors, energized by the plasma. However, to this date, methods for gas delivery in CVD, including PECVD type systems, have much room for improvement. [0007] One problem with many diffusing showerhead systems relates to limited gas flow dynamics and control capability. For example, gas delivered through a typical showerhead covers a diffusion zone inside the chamber that is produced by the array of diffusion holes placed in the showerhead. If a system is designed for processing a 200-mm wafer or wafer batch, the gas diffusion apparatus associated with that system will produce a zone that is optimum for that size. If the wafer size is increased or reduced beyond the fixed zone capability of a particular showerhead, then a new diffusion apparatus must be provided to accommodate the new size. There are typically no conventions for providing more than a few zones or for alternating precursor delivery for differing size substrates in one process. [0008] In an environment wherein different sizes of substrates are commonly processed, it is desired that diffusing methods and apparatus be more flexible such that multi-zone diffusing on differing size substrates is practical using one showerhead system. This would allow for less downtime associated with swapping equipment for varying situations, and better uniformity by combining and alternating different zones during diffusion. Prior art diffusing methods and apparatus do not meet requirements for this type of flexibility. [0009] Another problem in this technology is that various gases of different characteristics are mixed for a particular process. There are variations in density, temperature, reactivity and the like, such that perfect uniformity in gas mixture composition and density at delivery still does not produce precise uniformity in layer deposition. In some processes an intentional non-uniformity of gas delivery will be required to produce layer uniformity. [0010] What is clearly needed is an enhanced precursor-delivery apparatus and method that allows for a strict and combined control of gas distribution over multiple target zones in a reactor, and has several degrees of freedom in gas mixing, delivery, and uniformity control. Such a system would provide a capability for adjusting gas flow in a manner that point-of-process reaction uniformity may be achieved, providing superior film property uniformity. Such a system may be adapted to function in a wide variety of CVD and PECVD applications. SUMMARY OF THE INVENTION [0011] In a preferred embodiment of the present invention a showerhead diffuser apparatus for a CVD process is provided, comprising a first channel region having first plural independent radially-concentric channels and individual gas supply ports from a first side of the apparatus to individual ones of the first channels; a second channel region having second plural independent radially-concentric channels and a pattern of diffusion passages from the second channels to a second side of the apparatus; a transition region between the first channel region and the second channel region having at least one transition gas passage for communicating gas from each first channel in the first region to a corresponding second channel in the second region; and a vacuum seal interface for mounting the showerhead apparatus to a CVD reactor chamber such that the first side and supply ports face away from the reactor chamber and the second side and the patterns of diffusion passages from the second channels open into the reactor chamber. [0012] In preferred embodiments the second side comprises a flat surface such that the diffusion passages from the second channels open into the reactor chamber on a plane. Also in preferred embodiments the vacuum seal interface comprises a flange having bolt holes and an o-ring for mounting to and sealing to a wall of the reactor chamber. [0013] To enhance gas diffusion and mixing in embodiments of the invention the supply ports into the first channels and the transition passages from the first channels into second channels are offset in position such that no supply port is aligned with a transition passage. In preferred embodiments there are also coolant passages in the second channel region facing the inside of a reactor chamber, for protecting the showerhead apparatus from heat from within the chamber, and for impeding process film deposition on the showerhead face. [0014] In another aspect of the invention a CVD reactor system is provided, comprising a reactor chamber having an opening for a showerhead apparatus; a support in the chamber adjacent the opening, the support for a substrate to be processed; and a showerhead diffuser apparatus for a CVD process, the showerhead having a first channel region having first plural independent radially-concentric channels and individual gas supply ports from a first side of the apparatus to individual ones of the first channels, a second channel region having second plural independent radially-concentric channels and a pattern of diffusion passages from the second channels to a second side of the apparatus, a transition region between the first channel region and the second channel region having at least one transition gas passage for communicating gas from each first channel in the first region to a corresponding second channel in the second region, and a vacuum seal 5 interface for mounting the showerhead apparatus to a CVD reactor chamber such that the first side and supply ports face away from the reactor chamber and the second side and the patterns of diffusion passages from the second channels open into the reactor chamber. In the reactor system the second side comprises a flat surface such that the diffusion passages from the second channels open into the reactor chamber on a plane. [0015] In another aspect of the invention a method for distributing gases to a wafer in a CVD coating process is provided, comprising steps of (a) introducing gases for the process via individual supply ports into individual ones of plural radially-concentric first channels of a first channel region of a showerhead apparatus; (b) flowing the gases from the first channels via transition passages into corresponding radially-concentric second channels in a second channel region; and (c) diffusing the gases from the second channels through diffusion passages opening through a flat surface of the showerhead apparatus parallel to and adjacent the wafer to be coated. [0016] In yet another aspect of the invention a method for adjusting gas flux distribution over a wafer in a CVD coating operation is provided, comprising steps of (a) introducing gases for the coating operation via individual supply ports into individual ones of plural radially-concentric first channels of a first channel region of a showerhead apparatus; (b) flowing the gases from the first channels via transition passages into corresponding radially-concentric second channels in a second channel region; (c) diffusing the gases from the second channels through diffusion passages opening through a flat surface of the showerhead apparatus parallel to and adjacent the wafer to be coated; and (d) adjusting the gas flux distribution over the wafer by individually metering mass flow to individual ones of the individual supply ports to the first channels. [0017] In the embodiments of the invention for the first time a diffuser is provided with flexibility to adjust gas distribution flux in a number of different ways, allowing a diffuser to be dialed-in to account for many gas parameters such as reactivity and the like. Various embodiments of the invention are taught in enabling detail below. BRIEF DESCRIPTION OF THE DRAWING FIGURES [0018] [0018]FIG. 1 is an isometric view of a multi-zone diffuser according to an embodiment of the present invention. [0019] [0019]FIG. 2 is a section view of the multi-zone diffuser of FIG. 1 taken along the section line A-A. [0020] [0020]FIG. 3 is a diagram illustrating upper gas zones and gas transition passage locations according to an embodiment of the present invention. [0021] [0021]FIG. 4 is a diagram illustrating lower gas zones and gas diffusion passages according to an embodiment of the present invention. [0022] [0022]FIG. 5 is a block diagram illustrating three gas separation stages in the apparatus of FIG. 1 according to an embodiment of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0023] As described in the background section, obtaining consistent and uniform material layering in semiconductor manufacturing is paramount to producing high quality semiconductor devices. However, there are many limitations inherent to prior-art diffusing apparatus that continue to plague manufacturers using CVD or CVD-variant applications. The inventor provides in this disclosure a unique apparatus and method for enhancing process uniformity by utilizing multi-zone capabilities and strictly controlled gas delivery methods. The method and apparatus of the present invention is described in enabling detail below. [0024] [0024]FIG. 1 is an isometric view of a multi-zone diffuser 9 according to an embodiment of the present invention. Diffuser 9 is adapted for delivering gas precursors and inert gases for the purpose of depositing films in CVD or CVD-variant processes. [0025] Diffuser 9 is an assembly comprising in this embodiment three basic components, being an upper diffusion channel assembly 11 , a gas transition baffle-plate 13 , and a lower diffusion channel assembly 15 . Components 11 , 13 , and 15 are, in a preferred embodiment, rigidly integrated into a whole by brazing or other joining method. [0026] Diffuser 9 is designed and adapted to be fitted by a flange and suitable sealing elements to a process reactor (not shown) for the purpose of dispensing process gasses over a suitable substrate within. In one preferred embodiment Diffuser 9 engages through a lid of a single-wafer processing system. A lower portion (not visible in this view) of channel assembly 15 extends into a reactor when diffuser 9 is properly mounted. A plurality of through holes 19 on the flange portion of lower coil-assembly 15 are for bolts used in mounting to a lid of a reactor chamber, and holes 20 are provided for mounting an RF electrode in an alternative embodiment within a reactor for striking and maintaining plasma if required for any purpose, such as (PECVD. [0027] Diffuser 9 , by virtue of the above-described components, allows metered supply of gases to CVD or CVD-variant processes according to pre-calculated parameters. The features of diffuser 9 are designed to produce multiple radial gas-zones over a target in order to achieve an enhanced uniformity controllability in layer deposition that has not previously been achieved with prior-art systems. Diffuser 9 further provides an ability to supply a wide variety of gases in metered fashion to some or all of the defined gas zones either alternately or in combination. This unique capability allows manufacturers to easily fine-tune layer uniformity in process to achieve optimum and repeatable layer uniformity over simple and complex topologies. [0028] Upper coil-assembly 9 has a plurality of gas-supply passages 17 passing through an upper plate-surface. Each supply passage 17 feeds to one of multiple gas zones defined by a plurality of radial channels provided within assembly 11 , shown in further FIGS. and descriptions below. Gas supply tubes and fittings adapted to conduct gases to passages 17 are not shown here for simplicity. Coolant delivery tubes 21 (an inlet and an outlet) are provided on the upper surface of coil-assembly 11 and are adapted to allow coolant to circulate through coolant channels in diffuser 9 . More detail about diffuser 9 and internal components is provided below. [0029] [0029]FIG. 2 is a section view of diffuser 9 of FIG. 1 taken along the section line AA. Upper channel assembly 11 has a plurality of radial gas zones that are of differing diameters and are positioned in spaced concentric fashion. In this example, there are a total of thirteen zones 23 , however there may be more or fewer zones 23 without departing from the spirit and scope of the present invention. [0030] Each zone 23 is an independent circular channel, and is supplied by one gas supply passage 17 , four of which are shown in this section view. BY this arrangement different gases may be supplied to different gas zones 23 independently with no gas mixing or crosstalk from one zone to another. Moreover, because there is no crosstalk between individual zones 23 , differing flow pressures may be applied to each specific zone. For example, a low metered flow may be provided to a channel closer to the center of the diffuser while a higher metered flow may be applied to a zone closer to the outer periphery. In addition, zones 23 may be used in alternate fashion. For example, by selectively shutting off gas supply to any one or a combination of gas supply passages 17 , associated zones 23 may be shut off without affecting gas flow to other zones. This allows process operators much more flexibility when introducing separate gases into a process. [0031] Lower channel assembly 15 has concentric channels in the same radial geometry as upper channel assembly 11 , and baffle plate 13 , which forms a center portion of diffuser 9 , has a plurality of elongated gas transition passages 25 strategically placed therethrough, feeding gas from each upper channel to a corresponding lower channel. Baffle plate 13 is preferably manufactured of one solid metal piece. There may be any number and spacing of transition passages 25 through baffle element 13 for each pair of upper and lower channels without departing from the spirit and scope of the present invention. For example, an outer channel pair may have many more transition passages than in inner channel pair. [0032] Transition passages 25 are significantly elongated by virtue of the thickness of plate 13 and substantially smaller in diameter than supply passages 17 . Transition passages 25 may, as in this example, all be of the same diameter, or may be of differing diameters such as may be determined to effect specific desired gas flow characteristics. In addition to the length and diameter of transition passages 25 , zone specific orientation of and number of holes 25 per zone may vary according to calculated determinates, which may be obtained through computer modeling, and are intended to produce optimum uniformity characteristics. These calculated determinates also determine the thickness of baffle assembly 13 , thus defining the length of passages 25 . [0033] Channels 27 in assembly 15 are in this embodiment somewhat deeper (height) than channels 23 of assembly 11 . This feature aids in further diffusing of gasses before they are passed into a reactor. A plurality of gas diffusion passages 31 are provided through a lower portion of channel assembly 15 into a reactor. Passages 31 are for allowing gases to pass from channels 27 into the reactor. The gases passing through passages 31 into the reactor are optimally distributed according to pre-determined parameters. The number of gas diffusion passages 31 per channel is typically substantially greater in embodiments of the invention than the number of gas transition passages 25 per channel. For example, an outer-most channel 27 may have three transition passages 25 (inlet to channel) and, perhaps 30 diffusion passages 31 (outlet from channel). [0034] In embodiments of the invention an RF barrier ring 29 is provided one for each channel 27 . RF rings 29 are designed and adapted to baffle the passages from channels 27 into the reactor chamber in a manner that a plasma struck in the chamber will not migrate into channels 27 of diffuser 9 . RF rings 29 are made of a suitable electrically-conductive metal, and each RF ring 29 is preferably welded in each channel 27 just above the bottom surface of the channel, leaving space on the sides as shown, so gases passing from each channel 27 into a passage 31 must traverse a convoluted path of dimensions small enough to quench any plasma. In practice rings 29 are formed with three or more dimples facing downward at positions not aligned with passages 31 , the rings are positioned with the bottom surface of these dimples touching a surface slightly above the bottom of the respective channels, and the rings are then spot welded in the bottom of the channels to that mounting surface. [0035] Water passages 33 are provided in the walls separating channels 27 in channel assembly 19 allowing water cooling, as substrates to be processed are typically heated to a high temperature on a hearth in the chamber. Tubes 21 provide an inlet and outlet for coolant as previously described. [0036] It will be apparent to one with skill in the art that diffuser 9 may be manufactured in many different diameters having different numbers of gas zones and channels without departing from the spirit and scope of the present invention. In preferred embodiments, diffuser 9 is manufactured to accommodate a specific semiconductor wafer size, such as a 200 mm or 300 mm wafer. In practical application a diffuser made for one wafer size may be used for wafers of a smaller size by closing gas supply to outer channels and tuning gas supply to remaining channels. [0037] It will also be apparent to one with skill in the art that a diffuser according to embodiments of the present invention may be manufactured according to dimensional determinates derived from computer modeling of gas flow dynamics. In this way, extensive field testing of uniformity characteristics normally required in prior-art process applications can be avoided. However, fine-tuning uniformity characteristics such as by adjusting flow rates to specific gas zones, shutting down certain gas zones, and the like may be practiced during process by operators using diffuser 9 . [0038] [0038]FIG. 3 is a diagram illustrating arrangement of upper gas channels 23 and exemplary locations of gas transition passages 25 according to an embodiment of the present invention. Channels 23 are in a concentric arrangement in relation to one another as previously described. Each channel 23 communicates with specific gas transition passages 25 , which are machined through baffle-plate 13 . For example, the centermost channel 23 has one gas transition passage 25 . A third channel 23 (counting out from center) has two gas transition passages 25 . Progressing toward the periphery, each successive channel thereafter has three gas transition passages 25 . This specific arrangement in terms of number of passages 25 for each channel 23 is not to be construed as a limitation, but simply that centermost gas channels will typically require less gas flow than outer channels. [0039] Transition passages 25 are, in this embodiment, arranged in an equally-spaces formation (120-degree placement) with respect to each channel 23 having three passages per channel. Each formation of transition passages 25 has an offset orientation from passage locations in adjacent channels This helps to facilitate even gas dispersal from upper channels 23 to lower channels 27 , however, it is not required to practice the present invention. Computer modeling in different embodiments provides optimum data for quantity and positioning of transition passages 25 to facilitate optimum gas flow dynamics. [0040] Diffuser 9 provides at least four degrees of freedom for facilitating graduated transition of gases from outer to inner gas channels. One option is regulating passage dimensions for transition passages 25 and by providing a constant number of passages 25 for each channel 23 , with the passages for the channels closer to center having smaller passages and increasing the passage size (diameter) for passages in channels from channel to channel toward the outer diameter of the diffuser. Another option is to provide a constant number of transition passages per channel, but to regulate channel capacity by providing wider channels toward the center and narrower channels toward the outer diameter of the diffuser. Limiting the number of transition passages toward the center, as is shown here, is yet another option. Still another option is simply metering gas flow rates to each independent channel by virtue of channel-independent supply lines. [0041] [0041]FIG. 4 is a diagram illustrating placement of gas diffusion passages in lower channel-assembly 15 according to an embodiment of the present invention. Each channel 27 has a plurality of equally-spaced diffusion passages arranged in a circular pattern. Only two channels 27 are illustrated herein with diffusion passages 31 to avoid confusion, however, all zones may be assumed to have diffusion passages 31 . [0042] A marked difference between the arrangement of transition passages 25 as shown in FIG. 3 and diffusion passages 31 is that there are far more diffusion passages 31 than transition passages 25 . In this embodiment, passages 31 are placed one about every 12 degrees or 30 holes 31 per channel 27 . Page: 14 [0043] The hole spacing is not necessarily based on azimuthal location in all embodiments. In one embodiment the holes are based on maintaining a 0.375 distance between any hole and all the holes around it, including the holes on the next higher and/or lower radius. Current design has 69 holes on the outer most zone. The 300 mm based design has 125 on its outer most zone. Zone spacing is based on maintaining the same 0.375 distance. However, the number of diffusion passages may be more or fewer, and the number per channel may vary as well. [0044] The same flexibility regarding passage dimensions, channel width, channel combination or alternate use, quantity of passages, and so on is attributed to lower channel assembly 15 as was described above regarding baffle plate 13 and upper channel assembly 11 . Gas flow through diffusion passages 33 in any one channel 27 may be adjusted by metering gas to independent gas supply lines entering diffuser 9 . In most embodiments, diffusion passages 33 will be smaller than transfusion passages 25 and supply passages 17 . Each stage increases gas diffusion without turbulence thus obtaining better gas distribution and uniform flow. [0045] [0045]FIG. 5 is a diagram illustrating the three gas separation stages utilized by diffuser 9 according to an embodiment of the present invention. Diffuser 9 , as previously described, has an upper diffusion stage provided by upper channel assembly 11 . Gas is supplied to upper channel assembly 11 through zone-independent gas-supply lines 17 , represented here by an arrow labeled Gas In. In the upper diffusion stage, gas is introduced and diffuses in channels 23 (FIG. 3) before passing through baffle-plate 13 . [0046] A gas transition stage is performed by baffle-plate 13 with transition passages 25 . Gas in channels 23 is further diffused and directed as it passes through plate 13 . A lower diffusion stage is performed in channel assembly 15 . In the final stage the gases are further diffused as they pass through lower channel assembly 15 . In a chamber, the introduced gases conform to multiple radial gas zones created therein by virtue of diffusion hole placement and positioning. Also by virtue of the long and convoluted passages of gases into the reactor chamber, the gases finally enter the chamber without any sudden expansion or turbulence. In this way, a substrate may be uniformly interfaced to the gas flux facilitating uniform layer formation. Fine-tuning may be performed to further enhance uniformity by adjusting gas flow to separate channels, using some channels but not others, and so on. [0047] It will be apparent to one with skill in the art that the method and apparatus of the present invention provides a unique enhancement and control for process operators not provided by prior art diffusing apparatus used in CVD processes. The provision of multiple but separate gas delivery channels over a target is a significant enhancement over the prior art. [0048] It will further be apparent to a skilled artisan that because computer modeling of gas flow dynamics is performed to determine optimum parameters for dimensions of elements of diffuser 9 , such parameters may be varied for different types of processes. Such parameters may also change due to different determinates derived from improved modeling techniques. Therefore, the method and apparatus of the present invention should be afforded the broadest scope. The spirit and scope of the present invention is limited only by the claims that follow.

A showerhead diffuser apparatus for a CVD process has a first channel region having first plural independent radially-concentric channels and individual gas supply ports from a first side of the apparatus to individual ones of the first channels, a second channel region having second plural independent radially-concentric channels and a pattern of diffusion passages from the second channels to a second side of the apparatus, and a transition region between the first channel region and the second channel region having at least one transition gas passage for communicating gas from each first channel in the first region to a corresponding second channel in the second region. The showerhead apparatus has a vacuum seal interface for mounting the showerhead apparatus to a CVD reactor chamber such that the first side and supply ports face away from the reactor chamber and the second side and the patterns of diffusion passages from the second channels open into the reactor chamber. In preferred embodiments the supply ports, transition passages, and diffusion passages into the chamber do not align, and there is a special plasma-quenching ring in each of the second channels preventing plasma ignition within the channels in the showerhead. methods and systems using the showerhead are also taught.

CROSS REFERENCE TO RELATED APPLICATION [0001] Applicant claims the benefit of U.S. provisional patent application Ser. No. 61/588,207, filed Jan. 19, 2012. FIELD OF THE INVENTION [0002] This invention generally concerns an improved method and apparatus for installing an earthen well for retrieving and channeling water and other liquids or fluids. In addition, this method and apparatus will be used in the relief of hydrostatic earthen water pressure. BACKGROUND OF THE INVENTION [0003] When digging a typical well, well drillers usually use a tool that utilizes augered flighting, so that when the tool is moved into engagement with the surface of the earth and rotated the auger moves the tool into the earth and removes the surrounding material to the surface of the earth. This forms an open well shaft in the earth. When the well shaft is completed, the augered tool is removed from the well shaft and well casing and internal components can be built into the excavated shaft formed by the augered tool. [0004] Once the well bore is drilled, the driller installs well casing and well screens and fills the annulus around the casing with a gravel (filter) pack. The gravel pack prevents sand and fine particles from moving from the aquifer formation into the well. [0005] At the surface of the well, a surface casing is commonly installed to facilitate the installation of the well seal. The surface casing and well seal protect the well against contamination of the gravel pack and keep shallow materials from caving into the well. [0006] It is problematic that the excavated well shaft will collapse if the surrounding soil is not stable. When the well shaft is to be excavated at an angle other than vertical, there is even a greater risk of well collapse due to gravity. To avoid a well collapse, well drillers often use drilling fluids such as bentonite to help maintain the shape and integrity of the shaft. Also, the excavated well usually develops debris during the digging activities that tends to fall into the excavated shaft that may form an obstruction to placement of the well casing into the well excavated shaft. Well drillers usually must remove the debris from the excavated shaft before the well casing is placed in its final position within the shaft. To remove the debris well drillers typically use fluids that circulate in the excavated well shaft. Use of these materials and the associated labor increase the costs of the well installation, and in some situations may cause the well drillers to move the site of the well. SUMMARY OF THE INVENTION [0007] This disclosure concerns a direct torque segmented helical displacement well formed in preassembled sections that are moved to the well site for their assembly. The helical displacement well includes a penetrator tube that functions as a leading drill conduit as it is being installed in the ground, and includes extension tubes that are mounted coaxially on the penetrator tube at the well site. [0008] The penetrator tube includes external helical plates that draw the conduit segments of the well into the ground in response to rotating the well conduit segments. The helical plates remain affixed on the penetrator tube and function to thrust and stabilize the penetrator tube and extension tubes in the ground. The assembly may include a closed penetrating end cap that covers the bottom opening of the penetrator tube and is shaped to assist in penetrating the earth and retarding the movement of earth into the well segments. [0009] The penetrator tube is configured for passing ground water from different types of wells including Artesian wells upwardly toward ground surface. The helical plates remain affixed to the penetrator tube in the bore hole of the well for the life of the well. [0010] This is a disclosure of a helical displacement well that utilizes prefabricated tubular segments to form the well structure with the lowermost well segment having externally protruding helical plates that extend into the earth and support the assembled well in the earth. The upper end of the cylindrical penetrator tube is fitted to receive a coupling capable of resisting torque necessary to turn the penetrator tube into the ground, to accommodate an open annulus and provide a positive means of fixed retraction of the well structure from the ground. [0011] The helical well system of this disclosure can be installed in just minutes as compared to hours with conventional means. Readily available construction equipment typically used for installing helical piles is all that is needed to install the helical displacement well disclosed herein into the earth. [0012] The penetrator tube of the helical displacement well assembly acts as a direct torque penetrator tube that functions as a lead conduit that remains insitu with the earth and forms the leading end of the well casing that supports other components of the well. The helical displacement well penetrator tube includes a cylindrical casing with laterally extending helical plates mounted to the exterior of the casing that are angled so that when the casing is rotated the helical plates move the well casing into the ground, creating thrust for the installation of subsequent well casing. Subsequent tubes known as extension tubes are affixed to the penetrator tube and to each other to complete the insitu well casings in place as they are turned into the earth. [0013] The helical plates and the well casing that supports the helical plates tend to compact the adjacent earth that is being displaced during the penetration process, instead of moving the displaced earth to the surface of the ground as done by the typical augered shaft installations. The compaction of the earth adjacent the well casing provides additional support and stability of the helical displacement well. [0014] When the helical plates of the penetrator tube reach the desired depth in the ground they extend laterally into the adjacent soil and become anchors for the well structure. This is in contrast to the function of an auger that has a continuous blade that wraps continuously about the shaft and moves the adjacent soil to the surface of the excavated well and that must be removed and disposed of. The internal components of an auger excavated well are placed into the confines of the penetrator tube and extension tubes of the excavated well after it has been excavated. By contrast, the segments of the helical displacement well, including the penetrator tube and extension tubes, have their internal components placed inside their casings prior to moving these well segments into the ground. [0015] Once the prior art excavated wells have been constructed, even those utilizing drilling fluids, the subsequent purging and flushing development of the well is accomplished by utilizing air and/or water in order to create a clean flow. By contrast, when the helical displacement well as disclosed herein is used, drilling fluids may be eliminated and the well development phase is either eliminated or substantially reduced. [0016] In the helical displacement well the penetrator tube becomes part of the well casing and functions similar to a helical pile of the types used as foundation support elements. The helical plates about the well casing creates thrust through the soils, pulling the shaft of the helical casing into and through the soil until the helical plates enter resistant soils. The helical plates eventually may be bored into a rigid soil matrix at which time the resistance due to the stiffness of the soils allows the helical plates to support the load of the well casing in either compression or tension. The designed load in either compression or tension is supported as the helical plates rest within the more rigid soil matrix and is transferred through the shaft of the helical well casing through and into the soils dense enough and strong enough to support the specified load and length. [0017] Installation of the helical displacement well can be accomplished from an external or internal means in much the same manner as helical piles are currently installed. Hydraulic drill motors are used to torque the helical displacement well into the ground. Torque indicators usually are used to monitor the torque during installation in order to provide sufficient data to verify that the helical displacement well is properly installed since there is a direct correlation to load capacity and torque. [0018] A natural subterranean Artesian well may be created due to hydrostatic pressure. In the typical Artesian well, the water is trapped beneath impervious or semi-impervious layers of soil or rock and placed under pressure by a higher elevated aquifer. Artesian wells usually include an open ended pipe casing drilled into the earth and into or through these impervious or semi-impervious soil and rock layers. The pipe creates a relief artery for the water to escape. The helical displacement well of this invention that is hydraulically driven into the soil creates an excellent means of providing a controlled Artesian well, especially in shallow applications. [0019] Another application of this invention is the relief of deep hydrostatic groundwater pressure behind earthen retaining walls. There are times when civil design engineers must overdesign these structures when there is a reason to believe that the existing hydrostatic groundwater pressure deep behind the retaining wall creates an unknown and undetermined problem. The helical pipe casings may be drilled on an angle or horizontally behind the wall to provide a relief conduit for the pressure imposed upon the wall to relieve itself. The relief can happen in the form of direct pressure from the hydrostatic head itself or from the gravity of the groundwater. [0020] The installation of this direct torque helical displacement well that relieves the pressure in the instances described above results in additional benefit for the owner, contractor and engineer when the system is installed as described herein. Since the well displaces the soil as it is penetrating the earth, the soil is compacted adjacent and along the longitudinal axis of the pipe conduit which improves the soil strength along and around its axis. The helical displacement well results in a two-fold benefit of removing the hydrostatic groundwater pressure effect on the wall and making it a stronger section where it has been installed. [0021] Sometimes existing walls such as retaining walls have been constructed utilizing underground drainage systems in their construction. There are times when problems result from poor workmanship in the construction of the drainage systems behind these walls. There may be times where the hydrostatic ground water pressures are not taken into consideration or they may be unknown at the time the wall was designed. The hydrostatic groundwater pressure relief aspect of this invention allows its pipe conduit to be installed after the wall has been constructed, allowing for a method of correction after a problem has occurred and has been identified. [0022] Another such application of the direct torque helical displacement well may be the relief of hydrostatic groundwater pressure from the seepage in, around and underneath a levee. Levees, sometimes referred to as dikes, usually are permanent earthen embankments built adjacent rivers or waterways in order to confine the flow of a river which might result in higher and faster water flow. They are also used to prevent flooding of adjacent lowland countryside and to slow natural course changes in a waterway in order to provide reliable shipping lanes for maritime commerce. [0023] In the past, potential levee breeches caused by seepage have been repaired or reinforced with sandbags used to increase and maintain the water seepage caused by hydrostatic groundwater pressure by increasing the height of the water flow in an attempt to equalize the pressure. Often times in the past, relief water wells have been installed in order to help remediate the seepage and to reduce or redirect the hydrostatic head flow. [0024] In utilizing the direct torque helical displacement well and hydrostatic relief system device and methodology of this disclosure, relief wells can be installed in and around sand boils which are telling signs of hydrostatic groundwater pressure in and around levees. The helical displacement wells are used to equalize, reduce or redirect the water flow without the pitfalls of current well construction and excavation techniques and the difficulties caused by constantly churning and flowing ground water. The utilization of this apparatus and methodology provides a quick, economical and sound way of fighting potential floods until the proper corrections can be made to repair the damaged levees. [0025] Time savings and equipment savings result in money saving advantages in this type of well installation. An additional advantage is that there are virtually no soils removed during the installation process which saves the time and effort of having to deal with those materials which may sometimes be contaminated. [0026] Another advantage is that the helical displacement well itself can be retracted, cleaned and reused at another location. Yet another advantage is that the wells can be installed in limited access, low overhead areas as well, and in remote locations where it would be cost prohibitive to move specialized well drilling equipment to a site, and would allow a more economical means of installing a well by utilizing readily available equipment to do so. [0027] The helical well technique as disclosed herein could be categorized as an entirely new method which may not even require the same permitting as currently required for well installation. The fact that the well can be installed in tight quarters, remote locations utilizing standard readily available construction equipment would make it valuable in many instances. [0028] Some advantages of the helical displacement well of this invention include the well functioning with virtually no soil excavated from the well hole, resulting in little or no required removal of displaced soil. There are no soils removed or spoils to dispose of: The well may be retractable from the ground since the helical casing can be rotated in the reverse direction in which it was installed, and may be reused The structure of the well is segmental in installation No specialized equipment is required and the well utilizes smaller readily available construction equipment The well is less expensive to install than with currently available well technology installations The well provides “Instant” well access The well can be produced with commonly available materials capable of withstanding the torques required for installation. The well substantially eliminates the need for expensive drilling mud and its costly maintenance and disposal, and minimizes the amount of flushing required due to the elimination of residual drilling mud or other drilling fluids during well development. The well allows for the end of the well to be sealed or capped in place as part of the drilled casing installation. The well provides a means of inserting a prepackaged gravel pack around the well screen and inserted into the helical pipe casing. The well can provide a larger diameter well as a “direct torque” means of installation over current “direct push” technologies which are limited by a reaction weight only. The well results in lower mobilization costs to and from the well site. The well minimizes the need for consumables, such as bentonite, sand and grout in most applications. [0041] A special coupling may be used to mount the extension tube on the penetration tube which eliminates the need for bolts to be placed through the conduit sections to resist the applied torque and keep the conduits linked together. This keeps the internal annulus of the pipe open at the coupling points, providing the necessary space to receive a well screen, pump and other interior apparatus, material, medium or equipment, to allow moving a liquid from one position to another. This technique will also allow a liquid to flow freely through the conduit shaft of the unit and gravity feed as a drainage vessel without obstruction through the shaft. [0042] Holes fabricated into the appropriate sections of the well casing will allow water or any other liquid to infiltrate and migrate to the interior regions of the conduit and pool at the ground water level. An exception might be from an Artesian well whereas the water is hydraulically forced into, through and out of the conduit by earth pressure, to a level higher than the ground level. [0043] Since there are variable requirements of installation for the conduits, the conduits will be capable of installation at different angles from vertical, from the horizontal to the vertical, depending upon the application. The segments of the conduit may be fitted with a sectional, multiple or single length well screen sleeves or other types of filter media in order to assist in filtering the water as it enters the conduit. [0044] The segmented well disclosed herein also may be used in combination as a pile, and as a means of providing drainage for various soil conditions and applications and also to provide water wells capable of being utilized to remove and/or treat or monitor insitu water levels. The helical displacement conduit can also serve as a structural element providing a potential dual purpose. [0045] Another advantage of this well installation method includes the capability of retraction from the ground at any time during installation or after the well is of no further use. [0046] Yet another advantage of this method of installation would be that upon extraction, the well can be cleaned and reutilized which would offer significant potential savings to the end user. The helical displacement well would be an excellent means of water monitoring in environmentally sensitive soils, or providing shallow access to water in remote locations economically. [0047] Other objects, features and advantages of this invention will become apparent upon reading the following specification when taken in conjunction with the accompanying drawing. BRIEF DESCRIPTION OF THE DRAWINGS [0048] FIG. 1 is a schematic view of the Direct Torque Helical Displacement Well showing the hydraulic equipment utilized to rotate the well assembly as it penetrates the earth. [0049] FIG. 2 is a side elevational view of the helical displacement well, showing its lower portion with the helical plates buried in the ground, and a detail of an open annulus coupling that connects the well segments together. [0050] FIG. 3 is a perspective view of the lower portion of the helical displacement well, showing the helical plates and a cut-away of the external tube to expose the geofabric, gravel pack, filter pipe and pump inlet screen. [0051] FIGS. 4 a , 4 b and 4 c are illustrations of a non-rotatable coupling that connects the segments of the external conduit together so that the segments rotate in unison. [0052] FIGS. 5 a , 5 b and 5 c are similar to FIGS. 4 a , 4 b , and 4 c , but show a modified coupling. [0053] FIGS. 6 a , 6 b and 6 c illustrate yet another type of modified coupling, similar to FIGS. 51 , 5 b , 5 c and FIGS. 4 a , 4 b and 4 c. [0054] FIGS. 7 a , 7 b , and 7 c illustrate a modified shear key type coupling. [0055] FIGS. 8 and 9 illustrate adjacent external conduits, with FIG. 8 showing the lower conduit with water openings formed therethrough and FIG. 9 showing a similar conduit but without water openings that would be used higher up in the well structure. [0056] FIGS. 10 a and 10 b are side views of segments of the helical displacement well, showing how the helical plates are mounted to the external steel conduit, and a rotated view revealing the end cap and port spacing. [0057] FIGS. 11 a . 11 b and 11 c illustrate a means of manufacturing an integral closed pile point from the lower end of the penetrator tube. [0058] FIGS. 12 , 13 , and 14 illustrate the different configurations of the seal cap pile point that may be used at the lower end of the penetrator tube. [0059] FIG. 15 illustrates a weep hole extension outlet. [0060] FIG. 16 illustrates a check valve attachment. [0061] FIG. 17 shows a side elevational view of the helical displacement well as it is installed in the ground. [0062] FIG. 18 is a side elevational view of an environmental monitoring well that is used for evaluating groundwater. [0063] FIG. 19 is a side elevational view of a helical displacement well installed in the ground and in application as an Artesian well. [0064] FIG. 20 is a side elevational view of a helical displacement well in an environmental recovery application where contaminants may be treated or extracted from the ground. [0065] FIG. 21 is a side elevational view, in cross section, showing a hydrostatic head relief well that is installed horizontally through a vertical concrete wall structure for drainage purposes. [0066] FIG. 22 is another side elevational view, showing the hydrostatic pressure relief well installed through a vertical soil nail wall application. [0067] FIG. 23 is a side elevational view, showing the hydrostatic relief well utilized behind a vertical block retaining wall. [0068] FIG. 24 is a side elevational view, showing the hydrostatic relief well utilized in conjunction with a soldier pile and lagging retaining wall. [0069] FIG. 25 is a side elevational view, showing the helical displacement wells being used in both hydrostatic groundwater pressure relief as well as a stabilizing internal structural element within the sloped embankment. [0070] FIG. 26 is a side elevational view of a helical displacement well showing how the well can be installed at an angle beneath a body of water. [0071] FIG. 27 is a side elevational view of a helical displacement well positioned behind a levee embankment intersecting a line of seepage underneath the levee caused by hydrostatic pressure resulting in an Artesian flow and thusly acting as a hydrostatic pressure relief system. DETAILED DESCRIPTION [0072] Referring now in more detail to the drawings, with like numbers referring to the same parts in the several views, FIGS. 1 and 2 illustrate embodiments of the assembled direct torque helical displacement well 1 which may be used as a well or as a hydrostatic pressure relief conduit. FIG. 1 shows how the well is being installed in the ground by an applied direct torque force exerted upon it by a hydraulic drive mechanism 7 to a penetrator tube 2 which is a rectilinear cylindrical tube and is rotated by the hydraulics from the hydraulic installation equipment 11 . The hydraulic drive mechanism is considered to be prior art and is available from Eskridge and is identified as an anchor drive. [0073] The helical displacement well 1 may include a leading external steel conduit penetrator tube 2 that makes the initial penetration in the soil and usually at least one external steel conduit extension tube mounted to the upper end of the leading penetrator tube 2 . Helical plates 4 are mounted to the external surface of the penetrator tube and extend outwardly from the penetrator tube. The helical plates are tilted with respect to the longitudinal central axis of the penetrator tube so as to act in an augering manner when the penetrator tube is rotated. This forces the penetrator tube axially through the surrounding earth. [0074] The hydraulic drive mechanism 7 is connected to a torque monitoring device 9 . The torque monitoring device is prior art and is fitted with digital readout gauges on the unit or a remote control device 10 to the upper end of the penetrator tube that allows the field personnel to monitor the amount of torque that is being applied to the helical displacement well 1 . This monitors the applied force in order to make field decisions as to the proper depth and soil resistance required to insure that the installation is completed in the correct manner. [0075] The drive tooling 8 of FIG. 1 includes the transition attachment from the torque monitoring device 9 to the helical displacement well and hydrostatic pressure relief device 1 , allowing the torqueing force from the hydraulic drive mechanism 7 to be uniformly applied as the helical displacement well is being inserted into the earth. [0076] As shown in FIGS. 1 and 2 , the helical plates 4 are affixed to the lower penetrating end section of the penetrator tube and the bottom opening of the penetrator tube is closed by the attachment of a penetrator cap 5 , also known as a pilot drive point, that also eliminates the likelihood of soil entering the penetrator tube. The helical plates create longitudinal thrust as the plates are torqued into the earth, pulling the external steel penetrator tube 2 into and through the earthen soil cap 26 and penetrating the ground water table 27 . [0077] The open annulus coupling 6 connects adjacent ends of the penetrator tube 2 and extension tube 3 , and additional extension tubes may be connected in like manner until the proper depth or torque limitation has been reached. The water ports 3 P may be drilled into the lower extremities of the external steel extension tubes 3 which allow for the penetration of the ground water 27 into the open annulus of the assembled conduits as the system reaches the ground water table beneath the surface of the earth. [0078] FIG. 2 is a closer elevation and perspective view of the helical displacement well or hydrostatic pressure relief vessel, the open annulus coupling and the installation tool train. Shown in a more detailed perspective is the helical displacement well or hydrostatic pressure relief conduit. Drive tooling 8 and a direct torque monitoring device 9 are fitted between the hydraulic drive equipment and the top of the penetrator tube or the top of an extension tube. The drive tooling 8 is temporarily affixed to the conduit in order to hydraulically turn the penetrator tube 2 and helical plates 4 into the ground. [0079] The penetrator cap 5 affixed to the insertion end of the external steel conduit 2 guides the assembly as it is driven into the earth. [0080] The helical plates that are affixed to the lower section of the penetrator tube create axial thrust to the assembled penetrator and extension tubes, thus pulling the assembled segments of the helical displacement well into the soil. The helical plates 4 are sized according to the anticipated strength of the soils being penetrated in order to provide maximum thrust and to maximize the depth as to which steel conduits 2 are pulled into the earth for each rotation of the helical plates. [0081] As shown in FIG. 1 , the penetrator tube 2 penetrates the soil cap 26 and the soil containing the ground water 27 and the ground water 27 enters the water inlet ports 2 P of the penetrator tube 2 and is extracted or monitored through the steel conduit 2 and extension tube 3 and the open annulus coupling 6 from ground level above. Additional steel extension conduit sections 3 may be added at certain intervals of downward movement of the assembled section of the helical well in order to obtain additional depth of the well. Optionally, the extension tubes may be fitted with water inlet ports 3 P. [0082] FIG. 3 illustrates an expanded perspective view of the helical displacement well or, depending on its use, the hydrostatic pressure relief conduit, showing the external steel conduit “casing” that represents the “lead section” or initial length of steel conduit known as the penetrator tube 2 that penetrates and enters the earth. The penetrator tube is fitted with the penetrator cap 5 that functions as a pile point, shown apart for clarity purposes, which creates a seal of the lower end of the assembled penetrator tube and extension tubes. This causes the water of the well bore to enter the well casings via the water inlet ports 3 P and into the annulus of the steel penetrator tube 2 , and provides a leading point to penetrate and guide the steel conduits 2 into the earth. [0083] As shown in FIG. 3 , the penetrator tube and extension tubes are prefabricated with filter inserts that filter the liquid entering through the inlet ports 2 P and 3 P. These filter inserts may include concentric tubular shapes of geofabric 12 , gravel pack 13 , PVC filter pipe 14 that includes filter slits 15 , and pump inlet screen 16 . The water entering through water inlet ports 2 P and 3 P engage and pass through the inserts. The perforated pump inlet screen 16 may be manufactured from stainless steel in order to reduce corrosion when the well is used for drinking water. [0084] When additional filtration is required at the lower extremities of the well, a prepackaged gravel pack 13 encapsulated within a geofabric 12 may be inserted telescopically and utilized to further the filtration process. [0085] The pump inlet screen 16 of FIG. 3 may be telescopically received within the PVC filter pipe 14 . The pump inlet screen 16 is cylindrical and may be inserted into the penetrator tube 2 of the well structure by itself, without the filter pipe, and may be made of stainless steel when the well is producing drinking water. [0086] The segments of the helical displacement well 1 are connected together by a non-rotatable coupling so that the penetrator tube 2 and the extension tubes 3 always rotate in unison. For example, FIGS. 4 a , 4 b and 4 c illustrate an open annulus spine coupling 24 that joins the adjacent ends of the penetrator tube and the extension tube, and for connecting the adjacent ends of additional extension tubes. The couplings define a central opening or “annulus” that allows for passage of liquid and objects such as water filters. The parts of the connector are shown separated in FIG. 4 a , coupled together in FIG. 4 b , and in cross-sectional view taken along the length of the coupled section in FIG. 4 c . The female coupling body 24 of the coupling is fabricated with internally facing splines 34 , and the adjacent ends of both tubes have complementary externally facing splines 35 that fit between the female splines 34 . Typically, the female coupling body will be mounted on the upper ends of both the penetrator tube and extension tubes prior to reaching the well site. When a tube is to be added to a previously installed tube, the tube to be added will have its open end connected to the coupling that was previously mounted on the prior tube. [0087] The spline coupling 24 may have internal protrusions as shown in FIG. 4C that stop the movement of the ends of the tubes into the coupling so that the ends of the tubes abut each other and avoid forming an obstruction to the movements of the filter inserts and liquid passing through the aligned tubes and maintain the inserts aligned from one tube to its adjacent tube. [0088] This spline design maintains the adjacent ones of the assembled tubes to be non-rotatably connected to one another and allows for multiplied torque resistance during installation. [0089] As shown in FIGS. 4 a , 4 b , and 4 c , the steel pipe conduit of the penetrator tube 2 is inserted within the female coupling and may be welded at 36 to make a positive connection. At the same time, buttress welds 22 are made parallel to the longitudinal axis in order to increase the torque resistance necessary for installation. [0090] As shown in FIG. 4 b , upon insertion of the male protrusion into the female receiver's matching splines, the coupling is made complete and the interior pipe diameters abut each within the coupling, allowing for a continuous open annulus of the steel conduit. A threaded recess tension bolt hole 33 is formed in the female coupling and becomes aligned with a matching smooth recessed tension bolt hole 32 formed in the male protrusion section of the coupling. A recessed tension bolt 31 is then inserted into the threaded tension bolt hole 33 with the end of the recessed tension bolt 31 protruding into the recessed tension bolt hole 33 of the no further than the interior surface of the open annulus pipe coupling 24 . Said recessed tension bolt 31 serves as a safety device for tension capacity in excess of what the coupling itself can afford during extraction of the steel conduit sections 2 . The recessed tension bolts also eliminate additional drag during the installation due to its unexposed bolt head not dragging through the soil as the steel conduits 2 penetrate the earth. [0091] FIGS. 5 a , 5 b and 5 c are another example of how the open annulus spline coupling 24 may be made. The female coupling body 24 is fitted interiorly with splines and spline receivers 34 along its full length. Positioned along the female coupling body which is open on both ends, are two (2) threaded recessed tension bolt holes 33 for receiving recessed tension bolts 31 . Recessed tension bolts 31 reduce the drag caused during installation of an exposed bolt head as the steel conduits penetrate the soil. In this application, there are two male protrusion ends fitted into the steel pipe conduit 2 that have matching splines 35 and intermediate spline receivers. Each of the male protrusion ends are equipped with a recessed tension bolt hole 32 that mirror the threaded tension bolt holes of the coupling body which receive the full length of the recessed tension bolts but no further than the interior surfaces of the steel pipe conduit sections 2 . [0092] FIG. 5 b shows this coupling technique in its coupled state and the recessed tension bolts 31 inserted and flush with the exterior surfaces of the coupling body. [0093] FIG. 5 c is a cross-sectional view of the open annulus spline coupling taken along its longitudinal axis and across the recessed tension bolts 31 in a coupled configuration. [0094] FIGS. 6 a , 6 b and 6 c illustrate another female coupling structure that joins the ends of adjacent aligned penetrator tube and extension tube together, using splined ends of another form. The inter fitting splines 35 lock the ends of the tubes 2 in a non-rotational relationship so that the application of torque to the upper end of the upper tube at ground level is passed through the tubes to the helical plates of the penetrator tube in the ground. [0095] FIGS. 7 a , 7 b and 7 c further illustrate a female coupling structure that joins the ends of adjacent aligned ends of the tubes, with the inner fitting splines locking the ends of the tubes in non-rotational relationship. [0096] FIGS. 8 and 9 illustrate two forms of the extension tubes, with FIG. 8 showing a tube with ports 3 P that admit water from outside the tube, and FIG. 9 showing a tube without ports. [0097] FIGS. 10 a and 10 b illustrates penetrator tubes, with FIG. 10 a showing the seal cap penetration point closing the angled end of the penetrator tube, and FIG. 10 b showing the same tube turned 90 degrees. [0098] FIGS. 11 a , 11 b , 11 c , 12 , 13 and 14 show other forms of the end caps, all of which tend to be aggressive penetrators of the soil when the penetrator tube is rotated and the helical plates force the penetrator tube into the ground. [0099] FIG. 15 shows the bottom of a penetrator tube and a weep hole extension 29 with a weep hole flap 38 applied to the end opening of the penetrator tube by weep hole sleeve connector 39 , showing this attachment both in an expanded view and in a closed view. [0100] FIG. 16 shows the end of a penetrator tube that includes a hydrostatic pressure relief check valve 30 that prevents debris from entering the end of the penetrator tube and that opens in response to the internal fluid pressure that exceeds the pressure about the valve for the purpose of expelling fluid in the lower end of the penetrator tube. [0101] As shown in FIGS. 17 and 20 , a pump may be connected to a pipe and the pipe extended down into the assembled segments of the helical displacement well. The pump draws the liquid from the well. [0102] As shown in FIG. 18 , the well may be closed at its upper end and used as an environmental monitoring well, extend down through free product 28 and into ground water 27 . [0103] As shown in FIG. 19 , a pipe may be inserted down into the helical well that is an Artesian well and the pressure of the natural source of the water moves the water up the pipe. [0104] FIGS. 21-25 illustrate the helical displacement well used horizontally to reach and relieve water trapped behind retaining walls or other vertical structures, while improving the strength of the soil matrix behind the structure or within an embankment. [0105] FIG. 26 illustrates the helical displacement well used horizontally to reach subterranean water that has strayed from a larger body of water, such as a lake or a river. [0106] FIG. 27 illustrates the helical displacement well utilized to relieve hydrostatic groundwater pressure behind a levee due to seepage. [0107] Should the helical displacement well not find water, it can be removed from the earth by rotating it in the opposite direction of installation so that the helix will tend to lift itself out of the earth. This avoids having to abandon parts of assembly in the earth and the time and efforts involved in boring the well shaft when not finding water. The device can be reused as may be desired. [0108] The external surfaces of the casing of the penetrator tube may be coated with an abrasive resistant friction reduction coating of water based silicon epoxy, capable of reducing the amount of surface friction encountered by the surfaces of ground penetrator tube and extension tube during installation into the earth. A suitable coating product as described above is a product known as Slickcoat produced by Foundation Technologies, Inc. of Lawrenceville, Ga., U.S.A. [0109] It will be obvious to those skilled in the art that variations and modifications of the disclosed embodiment can be made without departing from the spirit and scope of the invention as set forth in the following claims.

A helical displacement well with preassembled segments includes a preassembled shaft-forming penetrator tube including helical plates mounted to its exterior that may be rotated to propel the casing into the ground. A hydraulic drill motor rotates the penetrator tube and as it moves deeper into the ground. Extension tubes may be added to and coupled to the penetrator tube. A hydraulic drill motor is attached to the upper end of the extension tubes in order to continue the rotation of the assembled helical displacement well. The filter screen and the piping are installed concurrently with the addition of the extension tubes at the surface of the ground.

CROSS REFERENCE TO RELATED APPLICATIONS This application is an application filed under 35 U.S.C. §111 (a) claiming benefit pursuant to 35 U.S.C. §119(e) (1) of the filing date of the Provisional Application 60/075,585 filed Feb. 23, 1998 pursuant to 35 U.S.C. §111(b). FIELD OF THE INVENTION The present invention relates to a novel ascorbic acid derivative, a vitamin C preparation containing the same and a composition containing the same, such as a cosmetic preparation. The present invention also relates to a novel process for producing the ascorbic acid derivative. BACKGROUND OF THE INVENTION The effects of ascorbic acid include the inhibition of lipid peroxidation, acceleration of collagen formation, retardation of melanin formation, enhancement of immune functions and the like. For these purposes, ascorbic acid has hitherto been used in the fields of medical preparations, agricultural chemicals, animal drugs, foods, feeds, cosmetic preparations and the like. However, ascorbic acid has poor aging stability and poor liposolubility. Accordingly, the cumulative amount thereof in cells after permeating through the cell membrane is limited, and the physiological actions of vitamin C cannot be achieved to a satisfactory extent. To cope with this, various derivatives have been proposed, where the hydroxyl group present in the enediol part at the 2- or 3-position, which is easily oxidized, is transformed into a phosphoric acid ester (as described, for example, in JP-B-52-1819 (the term "JP-B" as used herein means an "examined Japanese patent publication") and JP-A-02-279690 (the term "JP-A" as used herein means an "unexamined published Japanese patent application")) so as to improve stability, or is acylated with a fatty acid to thereby improve liposolubility (as described, for example, in JP-A-59-170085). Of the conventional ascorbic acid derivatives, compounds having satisfactorily improved stability (for example, magnesium L-ascorbic acid 2-phosphate) still lack adequate liposolubility. JP-A-58-222078 proposes a 6-O-alkanoyl-ascorbic acid-2- or -3-phosphoric acid ester as a novel compound having increased stability and an appropriate solubility in lipoid. The alkanoyl group thereof has less than eleven carbon atoms, and only a pivaloyl group is disclosed as an example thereof. The compound of the present invention cannot be obtained by the production process disclosed in JP-A-58-222078. Furthermore, the novel compound disclosed therein does not have both sufficiently improved stability and liposolubility. JP-A-61-152613 describes a cosmetic material containing a 6-O-higher acylascorbic acid-2-phosphoric acid ester. In this patent publication: first, transformation into a sulfuric acid ester but not into a phosphoric acid ester is described; second, the ascorbic acid derivative thus obtained is not identified; and third, the results of the working examples thereof are closely similar to those of the working examples of JP-A-61-151107 where the same experiment is performed except for using a 6-O-higher acylascorbic acid-2-sulfuric acid ester. Taking these facts into account, it can be concluded that the ascorbic acid derivative used in JP-A-51-152613 neither discloses nor suggests a 6-O-higher acylascorbic acid-2-phosphate. EP0339486and German Patent Publication DE4000397A1 propose compounds such as 6-O-octadecanoyl-2-(O*,O*-diethyl-phosphoryl)-ascorbic acid. However, these compounds are intended to capture active oxygen, and the ethyl group or the like remains bonded to the phosphoric acid group. Therefore, these compounds have deficient stability, are hardly susceptible to the action of phosphatase, and are not easily biotransformed into ascorbic acid. As described in the foregoing, various L-ascorbic acid derivatives have been proposed, however, an ascorbic acid derivative having sufficiently high stability, appropriate liposolubility, and which is capable of satisfactorily attaining an increased ascorbic acid intracellular cumulative amount has not yet been obtained. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a novel ascorbic acid derivative having both sufficiently improved stability and liposolubility and facilitated cellular uptake. It is also an object of the present invention to provide an industrial method for easily producing the derivative, and furthermore, a composition capable of effectively bringing out the action of vitamin C, for use in medical preparations, agricultural chemicals, animal drugs, foods, feeds or cosmetic preparations. Under these circumstances, the present inventors have conducted extensive investigations. As a result, it has been found that the ascorbic acid derivative of the present invention, described below, is a stable compound having an appropriate liposolubility and which is transformed into ascorbic acid with an enzyme in vivo. Also, the compound of the present invention can increase intracellular cumulative amounts because its uptake into cells is facilitated and can effectively provide the physiological action of vitamin C. The present invention has been achieved based on the above findings. Namely, the above objectives of the present invention have been achieved by providing: 1. An ascorbic acid derivative which is a compound represented by the following formula (1) or a salt thereof: ##STR2## wherein R represents an acyl group having eleven or more carbon atoms and n is 0, 1 or 2. 2. The ascorbic acid derivative as described in 1 above, wherein n is 0. 3. The ascorbic acid derivative as described in 1 or 2 above, wherein R in formula (1) is selected from the group consisting of a lauroyl group, a myristoyl group, a palmitoyl group and a stearoyl group. 4. The ascorbic acid derivative as described in 1, 2 or 3 above, wherein the salt is a salt of a metal selected from the group consisting of alkali metals, alkaline earth metals, aluminum, iron, zinc and bismuth. 5. A process for producing an ascorbic acid derivative which is a compound represented by formula (1) above or a salt thereof, which comprises reacting an ascorbic acid-2-phosphoric acid ester or 2-pyrophosphoric acid ester or 2-triphosphoric acid ester and/or a salt thereof with at least one of a fatty acid, a fatty acid ester thereof and a salt thereof to produce a compound represented by formula (1) or a salt thereof, wherein R represents an acyl group having eleven or more carbon atoms and n is 0, 1 or 2. 6. A process for producing an ascorbic acid derivative which is a compound represented by the following formula (2) or a salt thereof, which comprises reacting an ascorbic acid-2-phosphoric acid ester and/or a salt thereof with at least one of a fatty acid, a fatty acid ester thereof and a salt thereof to produce a compound represented by the following formula (2) or a salt thereof: ##STR3## wherein R represents an acyl group having eleven or more carbon atoms. 7. The process for producing an ascorbic acid derivative as described in 5 or 6 above, wherein said reacting step comprises reacting in the presence of a condensing agent. 8. The process for producing an ascorbic acid derivative as described in 5 or 6 above, wherein said reacting step comprises reacting in concentrated sulfuric acid. 9. A vitamin C preparation containing the ascorbic acid derivative as described in 1 to 4 above as an effective ingredient. 10. A cosmetic preparation, agricultural chemical preparation, animal drug preparation, food or feed composition containing the ascorbic acid derivative as described in 1 to 4 above. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is described in detail below. The ascorbic acid derivative of the present invention is a compound represented by the following formula (1) or a salt thereof: ##STR4## wherein R represents an acyl group and n is 0, 1 or 2. This compound is stable and difficultly oxidized because the 2-position is esterified. Furthermore, this is a monoester of a higher fatty acid having 11 or more carbon atoms, preferably from 12 to 28 carbon atoms. Therefore, the compound can have appropriate liposolubility and facilitated cellular uptake. Furthermore, because the phosphoric acid group at the 2-position is readily hydrolyzed by phosphatase in vivo, and because the higher fatty acid ester is an ester with a primary alcohol (6-position) susceptible to the action of lipase or esterase, the compound of the present invention is easily biotransformed into ascorbic acid. The compound represented by formula (1) or a salt thereof of the present invention can be produced according to the following reaction scheme (in the case of n=0 in formula (1)): ##STR5## wherein R represents an acyl group having eleven carbon atoms or more and R' represents hydrogen, a cation or an alkyl group. More specifically, an ascorbic acid-2-phosphate (3) and/or a salt thereof is reacted with (4) which is at least one of a fatty acid, an ester thereof and a salt thereof to produce an ascorbic acid-2-phosphate-6-fatty acid ester (2) or a salt thereof. This reaction is preferably conducted in the presence of a condensing agent. For example, when sulfuric acid is used as the condensing agent, concentrated sulfuric acid, an ascorbic acid-2-phosphate and a fatty acid or an ester or salt thereof are mixed and reacted. The fatty acid ester (wherein in formula (4), R' is analkyl group) is preferably a lower alkyl ester such as a methyl ester or an ethyl ester. The starting materials may be used in equimolar amounts. However, as long as no problems occur during purification or isolation, one part may be present in slight excess. The reaction time and the reaction temperature vary depending on whether the fatty acid is a free acid, an ester or a salt, or the kind and the amount of the condensing agent. However, the reaction time is generally from 1 to 120 hours, preferably from 10 to 60 hours, and the reaction temperature is generally from 5 to 70° C., preferably from 15 to 30° C. The amount of water carried over from the starting materials or catalyst into the reaction solution is suitably 10% or less, preferably 2% or less. Where a solvent is used in this reaction, the sulfuric acid as the condensing agent may be used concurrently as the solvent, or the solvent may be selected from other solvents which can dissolve the starting materials. The purification or isolation may be performed using a known method such as solvent extraction, washing, salting out or column chromatography. For example, the ester or salt thus obtained may be isolated or purified by ether extraction or hexane washing. If desired, the ester or salt thus obtained may further be isolated or purified by reverse phase chromatography or the like. The salt of the compound represented by formula (2) can be obtained as a salt with the corresponding base by neutralizing the ascorbic acid-2-phosphate-6-higher fatty acid ester thus obtained with an appropriate base (e.g., sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, ammonia, monoethanolamine, diethanolamine, triethanolamine, dicyclohexylamine), for example, in a solvent capable of dissolution, such as water or methanol. Preferred examples of the salt include alkali metals, alkaline earth metals, aluminum, iron, zinc and bismuth. Of these, alkali metals such as sodium and potassium, and alkaline earth metals such as calcium and magnesium are more preferred. In the compound represented by formula (2), the hydroxyl group at the 3- or 4-position may be protected by a conventionally known group which can be easily transformed to a hydroxyl group, and the present invention includes compounds having such a protective group. This reaction can be applied not only to the production of the 6-O-higher fatty acid ester of an ascorbic acid-2-phosphate of the present invention, but also to the production of 6-O-lower fatty acid esters thereof. The ascorbic acid derivative of the present invention exhibits vitamin C activity having both remarkably improved stability and liposolubility as compared with conventionally known ascorbic acid derivatives. Accordingly, vitamin C can be supplied from a preparation having incorporated therein the ascorbic acid derivative of the present invention. Furthermore, when the ascorbic acid derivative of the present invention is blended in a medical preparation, agricultural chemical, food, feed or cosmetic preparation, vitamin C can be effectively supplied. The ascorbic acid derivatives of the present invention may be used in various medical preparations, for example, as an anti-arhythmic agent, an anti-cerebral infarction agent or an anti-disorder improving agent. These derivatives may be administered orally or parenterally in the form of conventionally used pharmaceutical formulations including, for example, tablets, capsules, liquid preparations or injections. The dosing level depends on the subject to be treated and the manner of administration, but is usually preferably about 0.05 mg/kg to 100 mg/kg body weight, more preferably about 0.5 mg/kg to 25 mg/kg body weight per day for oral administration, and preferably about 1 mg/kg to 10 mg/kg body weight for parenteral administration, and preferably about 0.05 mg/kg to 10 mg/kg body weight per day when administered by injection. The ascorbic acid derivatives of the present invention are also useful as a cancer metastasis inhibitor and in a pharmaceutical preparation or composition thereof, the ascorbic acid derivative as an active component is generally contained in an amount of from 0.01 to 100% by weight. Examples of the composition for peroral administration further include a tablet, pill, granule, powder, capsule, syrup, emulsion, suspension and nebula. These compositions can be produced by a known method using a carrier or excipient such as lactose, starch, sucrose or magnesium stearate. For parenteral administration, for example, an injection, a suppository, a plaster, an ophthalmic solution or a preparation for external application may be used. The injection is usually filled in an appropriate ampule. The suppository includes an endorectal suppository and a vaginal suppository. The preparation for external application includes an ointment, a nasal administration agent and a peroral administration agent. For formulating a preparation for external application, the composition of the present invention can be formed into a solid, semisolid or liquid solvent thereof according to a known method. For example, in the case of a solid, the composition of the present invention is processed into a powder composition as such or after adding and mixing thereto an excipient (e.g., glycol, mannitol, starch, microcrystal, cellulose) or a thickener (e.g., natural gum, cellulose derivative, acryl polymer). Similar to the case of an injection, the liquid can be formed as an oily or aqueous suspension. In the case of a semisolid, an aqueous or oily gel or an ointment is preferred. In any case, a pH adjusting agent (e.g., carbonic acid, phosphoric acid, hydrochloric acid, sodium hydroxide) and an antiseptic (e.g., para-hydroxybenzoic acid esters, chlorobutanol, benzalkonium chloride) may be added. For obtaining a suppository, the composition of the present invention may be formed into an oily or aqueous solid, semisolid or liquid suppository according to a known method. The ascorbic acid derivatives of the present invention may be blended in various cosmetic preparations as suppliers of vitamin C. Such cosmetic preparations may preferably be used for skin-makeup in the form of a skin-cream, pack or milky lotion. The ascorbic acid derivatives of the present invention may be blended preferably in a range of 0.05 to 5 weight % of the cosmetic preparation. Components which are generally used in cosmetic preparations may be blended in cosmetic preparations together with the ascorbic acid derivatives, so long as the effect of the present invention is obtained. Such components include oils and fats, waxes, hydrocarbons, fatty acids, alcohols, synthetic esters, surface active agents, thickening agents, inorganic chemicals, vitamins, perfumaries and water. Of the ascorbic acid derivatives of the present invention, the L-form is preferred in view of its vitamin C activity. Particularly, in view of liposolubility, the higher fatty acid ester at the 6-position is preferably a lauric acid ester, a myristic acid ester, a palmitic acid ester or a stearic acid ester. EXAMPLES The present invention is described below by reference to the following Examples, however, the present invention should not be construed as being limited thereto. Example 1 L-Ascorbic acid-2-phosphate-6-palmitate 10 mmol (3.8 g) of magnesium L-ascorbic acid-2-phosphate was dissolved in 60 ml of concentrated sulfuric acid and to the resulting solution, 15 mmol (3.8 g) of palmitic acid was added. The mixed solution thus obtained was homogeneously stirred and after standing at room temperature for 24 hours, the reaction mixture was poured into about 300 ml of ice water. The precipitate was extracted twice with 200 ml of diethyl ether. The extracts were combined and washed with 300 ml of 2N hydrochloric acid containing 30% isopropanol, and the diethyl ether was removed by distillation under reduced pressure. The deposit was washed twice with about 200 ml of n-hexane and then dried under reduced pressure to obtain 3.2 g of L-ascorbic acid-2-phosphate-6-palmitate (yield: 65%). Various analytic data of the compound thus prepared are shown below. MS m/z=493 [M-H], 495 [M+H], 517 [M+Na] 1 H-NMR (400 MHz, CD 3 OD) δ: 0.90 (3H, t, J=6.9 Hz, 7-H), 1.29 (24H, s, 6-H), 1.63 (2H, hep, J=7.3 Hz, 5-H), 2.38 (2H, t, J=7.4 Hz, 4-H), 4.12-4.30 (3H, m, 2, 3-H), 4.87 (1H, t, J=1.7 Hz, 1-H) The assignment numbers of the 1 H-NMR peaks are as follows. ##STR6## 13 C-NMR (100 MHz, CD 3 OD) δ: 14.4 (1C, s, 13-C), 23.7 (1C, 12-C), 25.9 (1C, s, 11-C), 30.2-30.7 (10C, s, 10-C), 33.0 (1C, s, 9-C), 34.9 (1C, s, 8-C), 65.5 (1C, s, 7-C), 67.9 (1C, s, 6-C), 77.2 (1C, s, 5-C), 115.3 (1C, d, J=5.7 Hz, 4-C), 160.4 (1C, d, J=3.8 Hz, 3-C), 170.5 (1C, d, J=6.1 Hz, 2-C), 175.1 (1C, s, 1-C) The assignment number of the 13 C-NMR peaks are as follows. ##STR7## Example 2 L-Ascorbic acid-2-phosphate-6-palmitate The reaction was performed in the same manner as in Example 1, except for using sodium L-ascorbic acid 2-phosphate in place of magnesium L-ascorbic acid-2-phosphate. As a result, 3.7 g of L-ascorbic acid-2-phosphate-6-palmitate was obtained (yield: 75%). Example 3 L-Ascorbic acid-2-phosphate-6-stearate The reaction was performed in the same manner as in Example 1, except for using methyl stearate in place of palmitic acid to obtain 4.2 g of L-ascorbic acid-2-phosphate-6-stearate (yield: 81%). Various analytic data of the compound thus obtained are shown below. MS m/z=521 [M-H], 523 [M+H], 545 [M+Na] 1 H-NMR (400 MHz, CD 3 OD) δ: 0.90 (3H, t, J=6.8 Hz, 7-H), 1.29 (28H, s, 6-H), 1.61 (2H, hep, J=7.2 Hz, 5-H), 2.37 (2H, t, J=7.3 Hz, 4-H), 4.11-4.31 (3H, m, 2, 3-H), 4.86 (1H, t, J=1.7 Hz, 1-H) The assignment numbers of the 1 H-NMR peaks are as follows. ##STR8## 13 C-NMR (100 MHz, CD 3 OD) δ: 14.4 (1C, s, 13-C), 23.7 (1C, s, 12-C), 26.0 (1C, s, 11-C), 30.2-30.7 (12C, s, 10-C), 33.0 (1C, s, 9-C), 34.8 (1C, s, 8-C), 65.6 (1C, s, 7-C), 68.0 (1C, s, 6-C), 77.3 (1C, s, 5-C), 115.3 (1C, d, J=6.1 Hz, 4-C), 160.3 (1C, d, J=3.8 Hz, 3-C), 170.5 (1C, d, J=6.1 Hz, 2-C), 175.1 (1C, s, 1-C) The assignment numbers of the 13 C-NMR peaks are as follows. ##STR9## Example 4 L-Ascorbic acid-2-phosphate-6-laurate The reaction was performed in the same manner as in Example 1, except for using sodium laurate in place of palmitic acid. As a result, 2.2 g of L-ascorbic acid-2-phosphate-6-laurate was obtained (yield: 50%). Various analytic data of the compound thus prepared are shown below. MS m/z=439 [M+H], 461 [M+Na], 483 [M+2Na], 505 [M+3Na] 1 H-NMR (400 MHz, CD 3 OD) δ: 0.90 (3H, t, J=6.9 Hz, 7-H), 1.29 (16H, s, 6-H), 1.63 (2H, hep, J=7.3 Hz, 5-H), 2.38 (2H, t, J=7.3 Hz, 4-H), 4.11-4.30 (3H, m, 2, 3-H), 4.86 (1H, t, J=1.7 Hz, 1-H) The assignment numbers of the 1 H-NMR peaks are as follows. ##STR10## 13 C-NMR (100 MHz, CD 3 OD) δ: 14.4 (1C, s, 13-C), 23.7 (1C, s, 12-C), 25.9 (1C, s, 11-C), 30.1-30.7 (6C, s, 10-C), 33.0 (1C, s, 9-C), 34.8 (1C, s, 8-C), 65.5 (1C, s, 7-C), 67.9 (1C, s, 6-C), 77.2 (1C, s, 5-C), 115.2 (1C, d, J=5.4 Hz, 4-C), 160.5 (1C, d, J=3.8 Hz, 3-C), 170.5 (1C, d, J=6.1 Hz, 2-C), 175.1 (1C, s, 1-C) The assignment numbers of the 13 C-NMR peaks are as follows. ##STR11## Example 5 L-Ascorbic acid-2-phosphate-6-palmitate magnesium salt The L-ascorbic acid-2-phosphate-6-palmitate of the present invention was added to purified water to a concentration of 2 mM, and magnesium oxide was gradually added thereto while stirring to effect neutralization (pH: about 8). As a result, L-ascorbic acid-2-phosphate-6-palmitate magnesium salt was obtained. Example 6 L-Ascorbic acid-2-phosphate-6-palmitate sodium salt The L-ascorbic acid-2-phosphate-6-palimitate of the present invention was dissolved in methanol to a concentration of 20 mM, and the same volume of a 60 mM sodium hydroxide methanol solution was mixed therewith while stirring. The mixed solution was filtered and the precipitate was collected, washed with a small amount of methanol and dried under reduced pressure to obtain L-ascorbic acid-2-phosphate-6-palmitate sodium salt as a powder product. Test Example 1 The 2 mM L-ascorbic acid-2-phosphate-6-palmitate magnesium salt obtained in Example 5 and a 2 mM aqueous solution of L-ascorbic acid-2-phosphate magnesium salt having excellent stability were allowed to stand at room temperature for 10 days. Then, their residual ratios (concentration after storage/initial concentration) were determined by HPLC through a column Shodex Asahipak NH2P-50 4E (trade name, manufactured by Showa Denko KK) to evaluate stability. The results are shown in Table 1. TABLE 1______________________________________Ascorbic Acid (derivative) Stability (%)______________________________________L-ascorbic acid-2-phosphate-6-palmitate 98 magnesium salt L-ascorbic acid-2-phosphate magnesium salt 97______________________________________ The ascorbic acid derivative of the present invention thus has a stability similar to L-ascorbic acid-2-phosphate magnesium salt. Test Example 2 About 6×10 5 cells of a normal human adult mamma epidermal Keratinocyte (available from Kurashiki Boseki KK) were sowed on a 60 mm plate and cultured in a serum-free culturing medium (manufactured by Kurashiki Boseki KK) for 2 hours, and after displacing with the same culturing medium having added thereto from 2 to 50 μM of an ascorbic acid or a derivative thereof, further cultured for 20 hours. The cells were collected by trypsin treatment, and the number of cells was counted by a Coulter Counter Model DN (trade name, manufactured by Coulter Electronics). The cells thus collected were washed with Hank's equilibrium salt solution, pulverized in an ultrasonic homogenizer, filtered through a Mol-cut II (UFPlLCC) (trade name, produced by Nippon Milipore KK) and analyzed by HPLC through a column Shodex Asahipak NH2P-50 4E (trade name, produced by Showa Denko KK). The amount of ascorbic acid and derivatives thereof was measured to determine the intracellular cumulative amount. As a control, culturing was performed in the same manner as above except for not adding ascorbic acid or a derivative thereof, and the ascorbic acid was quantitatively determined. The difference in the intracellular ascorbic acid cumulative amount between the case where ascorbic acid or a derivative thereof was added and the case where ascorbic acid or a derivative thereof was not added is shown in Table 2. The L-ascorbic acid-2-phosphate-6-fatty acid esters or salts thereof thus used were prepared by or in accordance with the methods described in the respective Examples. The 6-O-pivaloyl-L-ascorbic acid-3-phosphate was prepared by the method described in JP-B-3-55470. The 2-O-D-glucopyranosil-L-ascorbic acid was extracted from UV White (trade name, produced by Shiseido Co., Ltd.). Other reagents used herein were commercially available products. TABLE 2______________________________________ Intracellular Cumulative Amount Ascorbic Acid (Derivative) and Addition Amount Pmole/cell______________________________________L-Ascorbic acid 2-phosphate-6-palmitate 2 μM 0.0042 L-Ascorbic acid 2-phosphate-6-palmitate 2 μM 0.0040 sodium salt L-Ascorbic acid 2-phosphate-6-laurate 2 μM 0.0042 L-Ascorbic acid 2-phosphate-6-laurate 2 μM 0.0033 magnesium salt L-Ascorbic acid 2-phosphate-6-stearate 2 μM 0.0034 L-Ascorbic acid 2 μM <0.0002 L-Ascorbic acid 50 μM 0.0003 L-Ascorbic acid-2-phosphate sodium salt 2 μM <0.0002 L-Ascorbic acid-2-phosphate magnesium salt 2 μM <0.0002 L-Ascorbic acid-2-phosphate magnesium salt 50 μM 0.0022 6-O-Pivaloyl-L-ascorbic acid-3-phosphate 2 μM 0.0005 L-Ascorbic acid-2-phosphate sodium salt 2 μM <0.0003 2-O-D-Glucopyranosil-L-ascorbic acid 2 μM <0.0002 L-Ascorbic acid-6-palmitate 2 μM 0.0009 L-Ascorbic acid-2,6-dipalmitate 2 μM <0.0002 Not added 0.0000______________________________________ The derivatives of the present invention can yield an ascorbic acid intracellular cumulative amount equal to or greater than that attained when ascorbic acid or a conventional ascorbic acid derivative (for example, ascorbic acid-2-phosphate magnesium salt) is used, with a very low concentration (1/10 or less as compared with conventional derivatives). These results show that the effect of vitamin C can be very easily obtained using the ascorbic acid derivative of the present invention. Example 7 Feed Composition Product 30 g of L-ascorbic acid-2-phosphate-6-palmitate sodium salt of the present invention and 15 g of "Lucarotene 10%" (produced by BASF, β-carotene content: 10%) and wheat flour were mixed to make a total amount of 300 g. The mixture thus obtained was fed together with 30 ml of water to an extruder, kneaded, extruded into a stick, cut and dried to produce vitamin C enriched pellets for livestock, poultry and marine animals, each having a diameter of 3.2 mm and a length of 5 mm. Example 8 Skin Cream ______________________________________squalene 5.0 wt % cetyl alcohol 1.5 polyoxyethylene (20) sorbitan monostearate 2.0 polyoxyethylene (20) cetyl ether 1.5 vaseline 6.0 1,3-buylene glycol 7.5 L-Ascorbic acid 2-phosphate-6-palmitate 4.5 sodium citrate 0.5 methyl p-hydroxybenzoate 0.2 perfumary 0.01purified water remainder______________________________________ This mixture was stirred at 80° C. and then cooled to produce a skin-cream. Example 9 Milky Lotion ______________________________________squalene 3.0 wt % vaseline 2.0 microcrystaline wax 1.0 stearyl alcohol 0.5 dl-α-tocopherol 1.0 sorbitan fatty acid ester 1.5 polyoxyethylene (20) sorbitan monooleic 2.0 acid ester glycerol 5.0 L-Ascorbic acid 2-phosphate-6-laurate 1.5 perfumary 0.01purified water remainder______________________________________ This mixture was stirred at 70° C. and then cooled to produce a milky lotion. The novel ascorbic acid derivative of the present invention has facilitated cellular uptake, and can increase the ascorbic acid intracellular cumulative concentration with a small dose. By using the ascorbic acid derivative of the present invention, vitamin C can be effectively supplied and its action can be easily brought about. While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

A novel ascorbic acid derivative having both sufficiently improved stability and liposolubility, and facilitated cellular uptake. Also disclosed is a process for producing the derivative and a composition capable of effectively providing the action of vitamin C, for use in medical preparations, agricultural chemicals, animal drugs, foods, feeds or cosmetic preparations. The ascorbic acid derivative is a compound represented by the following formula (1) or a salt thereof: ##STR1## wherein R represents an acyl group having eleven or more carbon atoms and n is 0, 1 or 2.

FIELD OF THE INVENTION [0001] The present invention relates to a bay-filling member, and more particularly, to a bay-filling member for an electronic device. BACKGROUND OF THE INVENTION [0002] Electronic devices need to meet varying requirements depending on the particular installation and such requirements may change over time. Thus, electronic devices such as computers or servers typically contain a number of expansion bays that can be used to increase functionality, enlarge capacity, or accommodate further upgrades in the future. [0003] For example, a network server usually comprises a plurality of bays for hard disk drives, wherein each bay encloses a fixed storage space allowing a hard drive to be inserted for usage. Quite often, the actual needs of a particular installation do not require insertion of hard drives into all available bays. Any free bays will then be filled by a hard drive casing or the like, so as to avoid having openings in the free bays that could affect the heat dissipating airflow and adversely influence the operation of the server, and also to prevent external objects or contamination such as dust and debris from entering the server. [0004] Normally, in the conventional filling technique, the size of a hard drive casing employed to fill the free bays and the size of the casing of an ordinary hard drive are the same. Thus, the original mounting tracks or rails of the server can be used for inserting the hard drive casing into the free bay. However, implementing this conventional technique requires fabricating an entire hard drive casing. Thus, not only is the structure more complicated but also the cost of production is higher. [0005] In addition, implementing the conventional technique requires similar processes for assembling an ordinary hard drive during disassembly, only in reverse. Therefore, the process of disassembly is complicated and cannot be simplified, thereby making such implementation unfavorable. Further, as the hard drive casing employed in the conventional technique has the same size as an ordinary hard drive casing, the space required for storage after dissembly is therefore relatively larger. [0006] A conventional computer 1 , for example as shown in FIGS. 1A and 1B , comprises a panel 10 formed at the opening of a bay 12 , wherein the panel 10 is a thin slice and the size thereof corresponds to the size of the opening of the bay 12 . Inner-facing areas 102 near the vertical edges of the panel 10 comprise hook portions 103 respectively. During installation, the panel is aligned with the bay 12 and the hook portions 103 are pushed into corresponding positions of the bay 12 , so that it can be fastened to the bay 12 to provide cover. [0007] However, when the computer 1 needs a new hard disk drive to be installed therein, the panel 10 will then need to be disassembled from the bay 12 . But as the hook portions 103 are located in the interior of the main case of the computer 1 , the disassembling process is thus very inconvenient. If the panel 10 is forcibly pulled out from the edge of the panel 10 , it will damage the panel 10 very easily and the panel 10 will not be re-useable, thereby wasting resources and potentially affecting the structure of the case of the computer 1 . The conventional technique as such is not ideally suited to the intended usage. [0008] Due to the drawbacks of the conventional technique having a complicated structure, higher cost of production, an inconvenient and labor-consuming disassembly process, requirement for a larger storage space when not in use, and, more notably, the potential to damage the structure of the main case, it is desirable to develop a bay-filling member for an electronic device so as to simplify the structure, reduce the cost of production, simplify the disassembly process, and to reduce storage space, while safe-guarding the internal structure of the main case. SUMMARY OF THE INVENTION [0009] In light of the above prior-art drawbacks, a primary objective of the present invention is to provide a bay-filling member for an electronic device capable of simplifying the structure thereof. [0010] Another objective of the present invention is to provide a bay-filling member for an electronic device that can effectively reduce the cost of production. [0011] Still another objective of the present invention is to provide a bay-filling member for an electronic device that can simplify the disassembly process. [0012] A further objective of the present invention is to provide a bay-filling member for an electronic device that can reduce storage space when not installed. [0013] In accordance with the foregoing and other objectives, the present invention proposes a bay-filling member being filled into an electronic device having free bays in which the free bays have at least a first securing portion and a second securing portion, wherein the bay-filling member comprises at least a casing, a third securing portion, a fourth securing portion and elastic portions. The casing comprises a first side, a second side corresponding to the first side, a third side connecting to the first side and the second side, and a fourth side corresponding to the third side. The third securing portion is formed at the first side of the casing and correspondingly coupled to the first securing portion. The fourth securing portion is formed at the second side of the casing and correspondingly coupled to the second securing portion. The elastic portions are formed on at least one of the third side or the fourth side for being press-fit into the bay. [0014] Preferably, the casing further comprises a panel, wherein the panel may be a plastic panel. Further, the panel may comprise an operating portion and a heat-dissipating portion, wherein the operating portion may be a finger hole and the heat-dissipating portion may be an opening. The third securing portion may be a protrusion. The fourth securing portion may be a protrusion as well. The elastic portions may have a plurality of resilient strips and may further form junctions so as to be press-fit into the bay and provide grounding at the same time. [0015] Compared with the conventional bay-filling techniques, the bay-filling member in the present invention is designed to have the shorter length of a hard drive casing than the conventional one, so as to solve the complicated structural defects resulting from employing conventional casings for filling the free bays in the conventional techniques, and thus to correspondingly reduce the cost of production. Meanwhile, the third securing portion and the fourth securing portion are designed to correspond to the pre-formed securing structures of the bays, so that the elastic portions can be used to achieve the packing effect. The user only needs to use fingers, without any tool, to perform the disassembly process, thereby solving the problems of such an arduous and complicated disassembly process in the conventional process. In addition, as the length of the bay-filling member in the present invention is shorter, the defects of requiring larger storage spaces for the conventional hard disk drive after disassembly can thus be solved. [0016] Accordingly, the present invention is capable of simplifying the structure of a bay-filling member of an electronic device, reducing the cost of production, simplifying the disassembling process, and minimizing the storage requirement, so as to solve the shortcomings of the conventional bay-filling technique. BRIEF DESCRIPTION OF THE DRAWINGS [0017] The present invention can be more fully understood by reading the following detailed description of the preferred embodiments with reference made to the accompanying drawings, wherein: [0018] FIG. 1A and 1B (PRIOR ART) are schematic views showing the conventional technique, wherein FIG. 1A is a schematic view showing the structure of a board and FIG. 1B is the exploded view showing a board of FIG. 1A assembled with an electronic device; [0019] FIGS. 2A to 2 D are schematic views showing the structure of a bay-filling member of the preferred embodiment according to the present invention, wherein FIG. 2A is the front view of the bay-filling member, FIG. 2B is the right side view of FIG. 2A , FIG. 2C is the left side view of FIG. 2A and FIG. 2D is the bottom view of FIG. 2A ; and [0020] FIGS. 3A and 3B are the three-dimensional views at different angles showing the structure of a bay-filling member of the preferred embodiments according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0021] Preferred embodiments of a bay-filling member proposed in the present invention are described in detail as follows with reference to FIGS. 2A to 2 D and FIGS. 3A to 3 B. The present invention can be implemented or applied by other embodiments, and the details of the specification can also be reviewed and applied for modification and alternation without departing from the spirit of the present invention. It should be noted that in the preferred embodiments the bay-filling member is filled into an electronic device having free bays with at least a first securing portion and a second securing portion. Using a server as the electronic device having a bay openings not occupied with a hard disk drive as an example, both sides of the bay comprise a first securing portion such as a concave or a hole and a second securing portion such as a protrusion. Since such a structure is a common design for a server and the structures and the mechanism of a server and a hard disk drive are also well known, drawings for these are therefore not shown in the specification for the sake of simplicity and clarity of the characterized features and the structures of the present invention. [0022] FIGS. 2A to 2 D are perspective views of the structures of bay-filling member according to the present invention. The bay-filling member 2 comprises at least a casing 21 , a third securing portion 23 correspondingly coupled to the first securing portion, a fourth securing portion 25 correspondingly coupled to the second securing portion, and elastic portions 27 that engage a side of the bay by pressure. [0023] The casing 21 comprises a first side 211 , a second side 213 corresponding to the first side 211 , a third side 215 connecting to the first side 211 and the second side 213 , and a fourth side 217 corresponding to the third side 215 , wherein the size of the casing 21 is about the size of an ordinary hard disk drive but having a shorter length and being hollow so as to simplify the structure and to reduce the material used and the cost of production. As shown in FIG. 2A , the casing 21 may further comprise a panel 219 , wherein the panel 219 may be a plastic panel or any other panel capable of being adapted to an ordinary hard disk drive exposed on the surface of a server. Further, the panel 219 may comprise an operating portion 2191 and a heat dissipating portion 2193 . In this preferred embodiment, the operating portion 2191 may be a finger hole so that the user can insert a finger into the operating portion 2191 and pull out the casing 21 from that bay, whereas the heat-dissipating portion 2193 is equivalent to the heat-dissipating opening of the panel for an ordinary hard disk drive so as to maintain an equivalent way of heat dissipating when an ordinary hard disk drive is inserted. [0024] As shown in FIG. 2B , the third securing portion 23 is formed on the first side 211 of the casing 21 . In the preferred embodiment, the third securing portion 23 may be a protrusion corresponding to the first securing portion. The first securing portion such as a concave or a hole allows the bay-filling member 2 to be set in the bay while inserting thereinto so as to provide a securing effect; however, the bay-filling member 2 can still be pulled out readily with a bit of force if the bay-filling member 2 is to be removed from the bay. Moreover, it should be noted that the third securing portion 23 is designed to adapt to the structure of the first securing portion of a free bay. Therefore, if the first securing portion is modified into another design, the third securing portion 23 can be changed accordingly. For instance, when the first securing portion is a protrusion, the third portion 23 may be a concave or a hole, and is not limited to the aforementioned disclosure of the preferred embodiment. [0025] As shown in FIG. 2C , the fourth securing portion 25 is formed on the second side 213 of the casing 21 . In the preferred embodiment, the fourth securing portion 23 may be a protrusion corresponding to the second securing portion, and can be held or stopped by the second securing portion of the bay upon inserting the bay-filling member 2 into the bay. For example, as the second securing portion may be a protruded stopper and the size of the casing 21 is about the size of an ordinary hard disk drive with a relative shorter length thereof, by combining the fourth securing portion 25 with the second securing portion, the bay-filling member 2 undergoing insertion will therefore not be over-inserted in the bay; and further, the surface of the panel of bay-filling member 2 can be exposed from the bay and maintain approximate unity of appearance for the surface of various bays. Similarly, the fourth securing portion 25 is also designed to adapt to the structure of the second securing portion of a free bay. Therefore, if the second securing portion is modified to another design, the fourth securing portion 25 can be changed accordingly. As any person having ordinary skill in the art can do these kind of modifications, such variations are not further described. [0026] As shown in FIG. 2D along with FIGS. 3A and 3B , the elastic portions 27 are formed on the third side 215 and the fourth side 217 of the casing 21 , and may have a plurality of resilient strips. In the preferred embodiment, the elastic portions 27 may further form protruded parts such as junctions 217 so as to be pressure-fit into the bay and provide grounding at the same time. It is to be noted that in this preferred embodiment the elastic portions 27 are formed on the third side 215 and the fourth side 217 of the casing 21 respectively; however, in other embodiments the elastic portions 27 can be formed only either the third side 215 or the fourth side 217 . Also, although the elastic portions 27 are placed equidistance from each other in this preferred embodiment, the location, quantity, and the arrangement of the elastic portion 27 can be modified in other embodiments. As any person having ordinary skill in the art can do these kinds of modifications, such modifications are not further illustrated. [0027] Therefore, when the bay-filling member 2 is to be inserted into the bay, the casing 21 can be inserted as in the orientation shown in FIG. 3B until the third securing portion 23 correspondingly couples with the first securing portion and the fourth securing portion 25 correspondingly couples to the second securing portion, enabling the bay-filling member 2 to be quickly inserted and assembled into the bay. At the time, the elastic portions 27 can also provide useful frictional force so as to pressure-fit the bay-filling member 2 into the bay. Meanwhile, as the casing 21 is a hollow casing and has a heat dissipating portion 2193 equivalent to the heat dissipating hole on the panel of an ordinary hard disk drive, an equivalent way of heat dissipating can therefore be maintained when an ordinary hard disk drive is inserted; so as to avoid the openings of the free bays affecting the heat flow and heat dissipating and influencing the operation of the server, and also to prevent external objects such as dust and debris from entering the server machine. [0028] Alternately, when the bay-filling member 2 is to be removed from the bay, it is only required to insert the finger(s) into the operating portion 2191 and pull out the bay-filling member using a low but sufficient force to overcome the frictional forces of the coupled members and the elastic members with the bay, thus providing a bay-filling member that is readily removable. [0029] Compared with the conventional bay-filling techniques, the bay-filling member of the present invention is designed to have a shorter length casing than an ordinary hard disk drive and to adapt to the structure of the free bays, so as to simplify the structure and reduce the cost of production. Meanwhile, only the hand is required to perform the assembly/disassembly operations of the present invention of inserting or pulling out the bay-filling member, thereby simplifying the assembly and disassembly processes. In addition, as the length of the casing in the present invention is shorter than an ordinary hard disk drive, the storage space when not in use is thus correspondingly reduced. [0030] Accordingly, the present invention can provide a structurally simplified bay-filling member adapted for the structure of a free bay, having effects such as reducing the cost of production and the storage space required, and being capable of assembly and disassembly without any tools, so as to solve the shortcomings of the conventional bay-filling technique. [0031] The invention has been described using exemplary preferred embodiments. However, it is to be understood that the scope of the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements. The scope of the claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.

The invention provides a bay-filling member for an electronic device employed to fill-in empty, currently unused bays of the electronic device in which such bay have at least first and second securing portions, wherein the bay-filling member has a casing, a third securing portion correspondingly coupled to the first securing portion, a fourth securing portion correspondingly coupled to the second securing portion, and elastic portions for being press-fit into the bay so as to allow the bay-filling member to adapt to the structure of free bays to simplify the structure of the bay-filling member, in order to address the shortcomings of conventional techniques.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a Divisional of application Ser. No. 09/534,009 filed on Mar. 24, 2000 now U.S. Pat. No. 6,481,415; and claims the benefit of the earlier filing date of U.S. Provisional Application No. 60/126,199, filed on Mar. 25, 1999, which is incorporated by reference herein in its entirety. BACKGROUND OF THE INVENTION The present invention relates, in general, to mechanical linkages, and has applications in the fields of automotive, general mechanical, and civil engineering. In the field of automotive engineering, the present invention has particular applications in automotive power train engineering and engine throttles. BACKGROUND OF THE INVENTION A mechanical linkage having two ends can be used to transfer an input force at one end to an output force at the other end. In applications that require a varying force at the output end of a mechanical linkage, a varying force can be provided at the input end by a variable torque actuator or motor attached to the input end. However, variable torque motors are expensive and can be difficult to operate for providing the desired variable output force. Therefore, in applications that require a varying output force, there is a need for a mechanical linkage system that can provide a varying output force without the use of expensive variable torque motor. In the field of automotive engineering, engine throttle control typically requires a variable torque motor operatively connected to a throttle valve in an automotive throttle. An automotive throttle for regulating the delivery of intake air to the manifold of an internal combustion engine generally comprises a throttle body with a butterfly valve rotatably mounted within its bore. The configuration of the throttle body and the butterfly valve have been identified as apparently giving rise to mechanical resistances when the valve is close to the bore of the throttle body (i.e. when the valve is nearly fully closed), the plane of the valve approaching perpendicularity relative to the longitudinal axis of the throttle body. The resistances are believed to be due to ice or other contamination that can form in the small clearance between the butterfly valve and the throttle body inside diameter when the valve is nearly fully closed. Furthermore, the pressure drop across the valve approaches its maximum value when the valve approaches the nearly closed position. Therefore, to overcome the above mentioned mechanical resistances of the butterfly valve in the nearly closed position, the butterfly valve can be operatively connected to a variable torque motor. The variable torque motor can be configured to provide a relatively greater amount of torque at the valve nearly closed position than the torque needed at a valve partially or fully opened positions. However, there still remains a need for a throttle control system that can operatively control the butterfly valve in an automotive throttle without the use of expensive variable torque motors. SUMMARY OF THE INVENTION The present invention offers a solution to the foregoing problems by providing an assembly for providing a variable output torque based upon a constant input force. The assembly includes an actuator for providing a constant input force and at least one link operatively coupled to the actuator and to a pivot point such the constant input force is converted to the variable output torque. The present invention also provides an assembly for providing a variable output torque based upon a constant input force. The assembly comprises first and second links each having a first end pivotally mounted about a respective axis and each having a second end operatively coupled together an additional link, each of the first and second links having a different angular orientation relative to an imaginary line extending between the axes; and an actuator driving the first link pivotally about its axis at the constant input such that the second link is driven pivotally about its axis at the variable output. The present invention also provides an assembly for controlling the position of a throttle valve rotating about a first axis between a first position and a second position. The assembly comprises a motor for moving an actuator between two positions; and at least one link coupling the actuator and to the valve and imparting to the valve a first torque when the valve is in the first position and a second torque when the valve is in the second position, the second torque being less than the first torque. The present invention also provides a method for controlling the position of a throttle valve. The valve is pivotal about an axis of rotation. The method comprises applying a first torque with an actuator to the valve when the valve is in a first position; and applying a second torque with the actuator to the valve when the valve is in a second position. The present invention also provides a method for determining the position of a valve in a throttle. The valve is driven by an electric motor and a relationship has been established between the current drawn by the motor and the position of the valve. The method comprises measuring the current drawn by the motor; and determining the position of the valve from an established relationship between the current drawn by the motor and the position of the valve. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate presently preferred embodiments of the invention and, together with the general description given above and the detailed description given below, serve to explain features of the invention. FIG. 1 shows an embodiment of a mechanical linkage for providing a variable output torque based upon a constant input torque. FIG. 2 shows an embodiment of an electronic throttle control assembly according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the mechanical linkage assembly 100 according to the present invention includes a linear actuator 102 , pivoted about fixed pivot point 103 and operatively connected to a first end of link 104 at location 101 . Second end of link 104 is pivotally connected at second ends of links 106 and 108 at pivot point 107 . Link 106 , is also pivotally mounted at fixed pivot point 105 . First end of link 108 is pivotally connected to second end of link 112 at pivot point 109 . First end of link 112 is fixedly attached to link 111 at fixed pivot point 110 , thereby allowing simultaneous rotation of links 112 and 111 about fixed pivot point 110 . In operation, when a linear upward force is imparted on link 104 by linear actuator 102 , a clockwise torque is imparted on link 106 about fixed pivot point 105 . Similarly, a clockwise torque is imparted through link 108 onto links 111 and 112 about fixed pivot point 110 . As link 104 travels upward by means of the linear actuator 102 , it can be seen that because of the fixed locations of pivot points 103 , 105 and 110 , linear actuator 102 will pivot clockwise about fixed pivot point 103 . Additionally, as link 104 travels upward, the overall translation of pivot point 107 to position 116 relative to its original location at position 115 is initially greater in the vertical direction than in the horizontal direction. Therefore, the magnitude of the torque at fixed pivot point 110 is greater when pivot point 107 is at position 115 than that at position 116 . For translation from position 116 to position 117 , the magnitude of the torque at fixed pivot point 110 is greater when pivot point 107 is at position 116 than that at position 117 . Therefore, by providing a linear actuator 104 operatively mounted to two out-of-phase links 106 and 112 , a constant input torque about fixed pivot point 105 is transformed into a variable output torque about fixed pivot point 110 , without the use of a variable force actuator or a variable torque motor. It should be noted that an angular actuator could be used in place of the linear actuator 102 . Similarly a constant torque motor with a rotary shaft could also be used in place of the linear actuator 102 as will be described in detail below. Referring to FIG. 2, the throttle control assembly 200 according to the present invention includes an electronic torque motor having a shaft with centerline A, and a pivot point 201 offset from and rotating about the centerline A, which torque motor is secured adjacent to a throttle. The throttle includes a butterfly valve 205 , which rotates about a centerline B. A fixed crank 210 , having a pivot point 215 , is coupled to butterfly valve 205 . A link 220 of fixed length connects pivot point 215 with pivot point 201 . Pivot point 201 is offset from the centerline A of the motor and is fixed to an actuator 225 of the motor. The range of motion of the electronic throttle control assembly 200 includes three positions of interest. With the pivot point 201 in position 1 , the electronic throttle control assembly 200 is in a “limp home position.” In this position, in which the assembly 200 will reside when no electrical current is applied to the torque motor, the throttle is partially open, providing a fast idle engine speed only. When the pivot point 201 is moved to position 2 , a “hot idle position”, the assembly 200 rotates the butterfly valve 205 to provide the minimum airflow through the throttle. When the assembly 200 is moved to position 3 , it drives butterfly valve 205 to a vertical position (parallel with the longitudinal axis of the throttle body), such that the assembly 200 and the throttle are in a “wide open throttle position”. The assembly 200 according to the present invention provides an “over-center” link arrangement, which provides a very high force (torque) to the butterfly valve 205 at the point where the valve is close to the bore of the throttle body. Maximum torque is required at this point to overcome ice/contamination, which can form between the small clearance between the butterfly valve 205 and throttle body inside diameter when the assembly 200 is in this position. Also, when the butterfly valve 205 approaches the fully closed position, the pressure drop across it approaches a maximum, resulting in a high force on the butterfly valve 205 and the shaft. In addition to the over-center link according to the present invention providing high torque when required, the over-center link also allows the available torque to diminish as it becomes less necessary. Specifically, when butterfly valve 205 is in the wide open throttle position, minimal contact is possible between the butterfly valve 205 and the inside diameter of the throttle body. Also, as the butterfly valve 205 approaches the wide open throttle position 3 , the pressure drop across the valve approaches zero, under which condition the forces acting on the mechanism of butterfly valve 205 are minimal. An additional inventive feature of the assembly 200 according to the present invention provides a valuable redundant means of determining the position of the throttle, supplemental to the information provided directly by the throttle position sensor (not shown). Specifically, there is an accurate correlation between the electrical current draw by the torque motor and the signal output of a position sensor (not shown) typically attached to the throttle shaft. Thus the torque motor current can be measured, recorded and continuously updated in the engine control module (not shown) and compared with the shaft position sensor output to detect the failure of either means of measuring position. This inventive feature is not limited to application in the context of the illustrated embodiment, not even to torque motors, but rather is applicable to electronically controlled throttles generally. While the invention has been disclosed with reference to certain preferred embodiments, numerous modifications, alterations, and changes to the described embodiments are possible without departing from the sphere and scope of the invention, as defined in the appended claims and their equivalents thereof. Accordingly, it is intended that the invention not be limited to the described embodiments, but that it have the full scope defined by the language of the following claims.

The present invention provides an assembly for providing a variable output torque based upon a constant input force. The assembly includes an actuator for providing a constant input force and at least one link operatively coupled to the actuator and a pivot point such the constant input force is converted to the variable output torque.

TECHNICAL FIELD A fluid treatment assembly is already known, which assembly comprises, on the one hand, a filter constituted of at least one filtering element, and on the other hand, a centrifuging device which device comprises a rotary centrifuging enclosure provided with an admission conduit. In this known treatment assembly, the centrifuging treatment device is separated from the filter and is connected therewith via conduits external to each of said two treatment and filtering devices. Such a treatment assembly is bulky, its cost price is high and it is subject to accidents, particularly where the external connection conduits are concerned. Moreover, the filter is generally a filter with disposable filtering elements. BACKGROUND OF THE INVENTION It is the object of the present invention to overcome said drawbacks by providing a filter that comprises a device for cleaning each filtering element including a rotary distributor driven by a motor and designed to periodically isolate one part of the filtering surface in order to enable the cleaning thereof with clean fluid flowing backwards through each filtering element and then into the centrifuging device, for purifying same, via an evacuation conduit. Therefore according to the invention, the filtering element or element and the centrifuging enclosure are contained in a single casing, while the evacuation conduit for the cleaning fluid filled with impurities issues directly into the admission conduit of the rotary enclosure. The advantageous following dispositions are also preferably adopted: one end of one of the evacuation conduits is fitted in one end of the other of said two conduits, while the other end of the admission conduit is fixed on said single casing; said other end of the admission conduit is fixed to said casing via a bolt which, at the same time, obturates said other end; the centrifuging enclosure communicates with the inside of the casing via at least one outlet nozzle for the centrifuged fluid, which nozzle is oriented substantially perpendicularly to a radius passing through the axis of rotation of said centrifuging enclosure, in such a way that said centrifuging enclosure is driven in rotation by the reaction of the fluid coming out of said outlet nozzle or nozzles with respect to the fluid contained in the casing; said evacuation conduit is provided in the rotaty distributor; receiving chambers for receiving the fluid filtered by the filtering elements of the filter and the fluid treated by the centrifuging treatment device, are provided in said single casing, said chambers being separated one from the other by a fluidtight partition wall. DISCLOSURE OF INVENTION The invention offers the following main advantages: compactness of the treatment assembly, reliability of said assembly, and reduced production costs compared with the prior constructions. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more readily understood and secondary characteristics and their advantages will emerge from the following description of one example of embodiment. It is to be understood that the description and drawings are only given by way of indication and non-restrictively. Reference will be made to the accompanying drawings, in which: FIG. 1 is an axial section of a treatment assembly according to the invention, FIG. 2 is a section along II--II of FIG. 1, and FIG. 3 is a section along III--III of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The fluid treatment assembly illustrated in the figures comprises a filter and a centrifuging treatment device, both of them being contained in a single casing 1 made up of two parts 1A, 1B, assembled by bolts. The filter, which is contained in part 1A of the casing, comprises: two transversal end walls 2, 3 between which is provided a stack 4 of filtering elements 5, each one of which is shaped into a filtering disk 9, with two screens 6; a central axis 7; aligned bores 8, having the same diameter, and being coaxial to axis 7, each bore belonging to one of the filtering disks 9, in tight contact with the cylindrical external face 10 of a liner 11, which liner comprises a bore 15 co-axial to the axis 7; a central fluid distributor 12, mounted for rotation about axis 7, in tight contact with a bore 13 provided in the intermediate wall 2, said wall being itself tightly assembled to pans 1A and 1B of the casing; a U-section sector 14, provided in the fluid distributor 12, the periphery 16 of which bears tightly against the bore 15 of the liner 11, and which communicates with an evacuation conduit 17 provided in the fluid distributor 12, coaxial to axis 7; a driving fork 18, situated at the axial end of the fluid distributor 12 opposite the intermediate wall 2; a receiving chamber for receiving the filtered fluid 19, which chamber is provided inside the part 1A of the casing, contains the stack 4 of filtering elements 5 and is equipped with a connector 20 for the evacuation of the filtered fluid; an admission chamber 21 for admitting the polluted fluid to be filtered, said chamber being equipped with an admission connector 22 for admitting the fluid to be filtered; a motor 23, in this particular example, a hydraulic motor, for driving the fluid distributor 12 in rotation, said motor being fixed on the part 1A of the casing and being equipped with a driving member 24 operationally coupled to the fork 18 for driving the fluid distributor 12 in rotation. Each filtering element 5 comprises a plurality, counting twelve in the embodiment illustrated in FIG. 2, of angular sectors 41 which, through orifices 25 provided in the liner 11 and in the bores 8, are adapted, successively, to create a communication between the inside space 27 defined by the parts of the two screens 6 of the sector considered, and a conduit 26 which is provided in sector 14 of the fluid distributor 12 and which issues into the evacuation conduit 17, which latter is a blind conduit at the end of the fluid distributor 12 facing the wall 2. The centrifuging treatment device is contained in part 1B of the casing and comprises: a central admission conduit 28 for admitting the fluid to be centrifuged, of which one end 29 is constituted by an endpiece fitted in the open (non-blind) end 30 of the evacuation conduit 17, while the other end 31 is constituted by a female thread for fixing in an obturating bolt 32; the bolt 32 itself constitutes the end of a plug 33 screwed 34 into a transversal end plate 35 which defines, in part 1B of the casing, a chamber 36 for receiving the centrifuged fluid, which chamber is tightly separated from the chamber 19 receiving the filtered fluid, by the intermediate wall 2; a centrifuging enclosure 37 is mounted for rotating, via rings forming smooth bearings, about axis 7, which axis 7 is also the axis of the admission conduit 28 and of its external face 28A, said conduit therefore forming also a rotary shaft for the centrifuging enclosure 37; orifices 38 creating a communication between the admission conduit 28 and the inside 39 of the enclosure 37. A transversal bottom 40, which is perpendicular to the axis 7, defines the part of the centrifuging enclosure 37 which is placed in facing relationship to the transversal wall 2. Said centrifuging enclosure 37 is totally isolated from the receiving chamber 36 receiving the centrifuged fluid except for the communication created by two outlet nozzles 43, which are substantially diametrically opposite, and whose outlet orifices are directed so as to be substantially perpendicular to a diameter passing through the axis 7, and in two opposite directions. The treatment assembly works as explained hereinbelow. The fluid to be treated, which is admitted into the admission chamber fills in the inner spaces 27 of all the sectors of the various filtering elements 5, with the exception of the space inside the sector 41 of each filtering element which is temporarily isolated from the other sectors 41 by the U-section sector 14 which is, itself, in communication with the conduit 26. This fluid to be filtered, which is contained in said spaces 27, flows through the screens 6 of said sectors, depositing on the inner faces thereof, the impurities that it contains, and being received when cleared of its impurities, into the receiving chamber 19 receiving the filtered fluid which is ready to be used again. Conversely, as regards the sectors 41 of the various filtering elements which only communicate with the conduit 17, the pressure of the already filtered fluid which is contained in the chamber 19, causes past of said fluid to flow through the corresponding parts of the filtering screens 6, this enabling the impurities which have deposited on the inner faces of the screens to be periodically detached therefrom and to be driven into the evacuation conduit 17. The function of the motor 23 is to drive stepwise, sector 41 by sector 41, the distributor 12 in rotation so as to ensure that each angular sector 41 of the various filtering elements is periodically placed in communication with the evacuation conduit 17. Said fluid filled with impurities is conveyed directly via the evacuation conduit 17 and the admission conduit 28 towards the centrifuging enclosure 37, where it is received therein 39 and where, by centrifuging, it is cleared of its impurities. The purified fluid is then evacuated out of the enclosure 37 through the nozzles 43 and is received into the chamber 36 wherefrom it is released towards an application unit, via an outlet connector 44 provided in part 1B of the casing. It should be observed that the rotation of the centrifuging enclosure 37 is induced by the effect of reaction, with respect to the fluid contained in the enclosure 37, of the fluid escaping from the inside 39 of the enclosure 37 through the conduits 42 of the nozzles 43. Said reaction effect is sufficient to drive the centrifuging enclosure in rotation at a rotation speed--of the order of 6000 rpms--at which the centrifuging is effectively performed. As a reminder, the speed of rotation reached by the motor 23 is around 2 to 3 rpms. The advantage of the described embodiment resides in the compactness and light weight of the assembly; in the elimination of any leaks from the external connections between filter and centrifuging device, due to the elimination of said external connections; in the elimination of any risks of the external conduits breaking up, as these conduits have also been eliminated; and finally, in the obtained reduction of the assembly manufacturing costs. It is understood that the invention is not limited to the embodiment of filters equipped with disks or pads as filtering elements, but also covers the case of any other filters such as, for example, those having cylindrical screens. The motor 23, which is advantageously a hydraulic type motor, may also, as a variant, be of another type, such as electric. Finally, at least one nozzle 43 should be provided, and preferably an even number of diametrically opposite nozzles. The invention finds an application in the treatment of lubricating oils for "Diesel" type engines, or even in the purification of certain fuels used by said engines. The invention is not limited to the described embodiment, and on the contrary covers any variants that can be made thereto without departing from its scope or its spirit.

The invention relates to a fluid treatment assembly comprising a filter (4) which itself comprises filtering elements (5) and a cleaning device (12) for periodically cleaning each filtering element including a conduit (17) for the evacuation of the cleaning fluid filled with impurities resulting from the cleaning, the treament assembly further comprising a centrifuging device which itself comprises a rotary enclosure (37) connected to a fluid admission conduit (28). According to the invention, the filtering elements (5) and the enclosure (37) are contained in a single casing (1A-1B), while the admission conduit (28) is directly connected (29-30) to the conduit (17) for evacuating the cleaning fluid. The invention finds an application in the construction of a compact and reliable assembly.

BACKGROUND [0001] Many computer mainframes in use distribute power through a high-voltage bus from a centralized bulk power supply to one or more low-voltage, DC to DC converters located near associated components such as microprocessor boards and memory boards. By using localized DC to DC converters, the converters themselves may be constructed smaller as they need not contain energy storage elements (e.g., input capacitors) for voltage regulation and isolation from a utility power supply. Furthermore, the use of a high voltage distribution bus to feed localized, low-voltage DC to DC converters minimizes resistive power losses on the voltage busses. For example, a 1000 watt, high-density multichip module (MCM) operating at a supply voltage of 2 volts will draw 500 amperes (A) of current. Therefore, the distribution resistance on the low voltage bus will dissipate 250,000 W/Ω (since power dissipated =I 2 R). In contrast, the same amount of power distributed across a 350 volt bus is dissipated at only 8 W/Ω, a difference of over 30,000 times less power lost. [0002] In the event that one of the localized DC to DC converters in a computer system should happen to fail, the server and high voltage bus could be overloaded. An overload on the common high voltage bus, in turn, can affect other components dependent thereupon. Accordingly, a means is typically employed to prevent an electrical overload of a common high voltage bus. Specifically, an electronic or solid state circuit breaker (SSCB) connected to an active bus, such as a computer bus, will interrupt or limit the flow of current through the bus when it is sensed that the current exceeds a predefined value (i.e., a fault condition). A current sensing device may provide an input to a differential amplifier for comparison with a reference voltage. If an overcurrent condition is detected for a certain period of time, the output of the differential amplifier (coupled with a timing circuit) causes a shutdown latch or circuit to turn off a power transistor, thereby disconnecting the bus from the load circuitry. [0003] However, in the event of a sudden fault, such as experienced during a short circuit condition, the resulting fault current can quickly overshoot the desired maximum value before a typical SSCB can respond in time to thereafter limit the current. Because of this, the SSCB may itself be damaged, in addition to an overload of the common bus. BRIEF SUMMARY [0004] In an exemplary embodiment of the invention, a solid state circuit breaker is disclosed for use in connection with a voltage bus, the voltage bus supplying electrical current to a load. The solid state circuit breaker includes a current controller for controlling the magnitude of current supplied by the voltage bus. A first current sensor senses the magnitude of the electrical current supplied by the voltage bus, the first current sensor having an output in communication with the current sensor. An inductor is included within the first current sensor, the inductor providing a back electromotive force on the voltage bus. The back electromotive force is proportional to the rate of change of current flowing through the voltage bus. [0005] In one embodiment, the first current sensor further includes a differential amplifier, the differential amplifier having an inverting input terminal connected to the voltage bus and a non-inverting terminal connected to a first reference voltage. The differential amplifier further has an output connected to the current controller, wherein the differential amplifier provides a signal to the current controller, causing the current controller to limit the magnitude of current flowing through the voltage bus when the differential amplifier senses an increase in current flowing through the voltage bus during an overcurrent condition. BRIEF DESCRIPTION OF THE DRAWINGS [0006] Referring to the exemplary drawings wherein like elements are numbered alike in the several Figures: [0007] [0007]FIG. 1 is a schematic diagram of an existing solid state circuit breaker (SSCB); [0008] [0008]FIG. 2 is a current versus time waveform illustrating the performance of the SSCB shown in FIG. 1; [0009] [0009]FIG. 3 is a schematic diagram of an improved SSCB in accordance with an embodiment of the invention; and [0010] [0010]FIG. 4 is a current versus time waveform diagram illustrating the performance of the SSCB shown in FIG. 3. DETAILED DESCRIPTION [0011] Referring initially to FIG. 1, a existing solid state circuit breaker (SSCB) 10 is illustrated. SSCB 10 is shown connected in series with a load 12 fed by a high-voltage DC voltage bus 14 , which may provide a supply voltage of about 350 volts DC. The SSCB 10 features a current controller 11 , comprising an n-channel, enhancement mode power MOSFET (FET) Q 1 having a source terminal connected to current sensing resistor R S , and a drain terminal connected to load 12 . The gate of Q 1 is connected to the output of a buffer element 16 , which provides a driving voltage to the gate of Q 1 in response to an input signal applied thereto. Field effect transistors such as depicted by Q 1 are commonly used in SSCBs due to their low “on” resistances, which help to maintain good efficiency. [0012] A first current sensor 18 includes a differential amplifier 20 having a non-inverting terminal (+) connected to a first reference voltage, V 1 REF . The inverting terminal (−) of the differential amplifier is connected to the source terminal of Q 1 and R S though resistor 22 . The output of differential amplifier 20 is fed to an overcurrent timer 24 , as well as to the input of buffer element 16 , through resistor 26 . In addition, the output of differential amplifier 20 is also fed back to the inverting terminal (−) thereof through a zener diode 28 . Finally, a shutdown latch 30 receives an input signal from the overcurrent timer 24 and has an output connected to the input of buffer element 16 through diode 32 . [0013] During normal operation of the SSCB 10 in FIG. 1, Q 1 is fully turned on as a result of a high output state of differential amplifier 20 . Differential amplifier 20 is in a high output state during normal operation, since the current flowing through RS is less than the set threshold level of differential amplifier 20 as determined by V 1 REF /R S . Typically, V 1 REF is on the order of a few tenths of a volt in order to minimize the power lost in R S . Zener diode 28 regulates the output voltage of differential amplifier 20 , keeping it in the linear region and preventing it from saturating, thereby allowing differential amplifier 20 to quickly respond to an overload condition. Furthermore, zener diode 28 limits the gate voltage applied to Q 1 . In doing so, zener diode 28 thus limits the amount of charge that must be removed from the gate of Q 1 in order to turn Q 1 off during an overload. [0014] In the event that an overload condition occurs, an increased current initially flows through R S which triggers a change (decrease) in the output voltage of differential amplifier 20 . As a result, differential amplifier 20 adjusts the gate voltage of Q 1 in order to maintain the fault current at the desired value determined by V 1 REF /R S . For example, the desired maximum fault current value may be about 12.5 amperes (A). At the same time, overcurrent timer 24 is triggered to begin timing the duration that the overcurrent condition exists. If the overcurrent condition continues to exist after a predetermined or “hold” period, the overcurrent timer 24 will send a signal to shutdown latch 30 , which then completely shuts off Q 1 by providing a path from the gate of Q 1 to ground through diode 32 . [0015] One problem with the above described SSCB 10 , however, arises in the situation where a severe overload condition occurs, such as a short circuit. In such a case, the resulting fault current will actually exceed the maximum desired value for a certain period of time due to the finite time delay inherent in the SSCB 10 , which delay prevents an instantaneous response. A resulting current overshoot could then damage the voltage bus 14 or the SSCB 10 itself. [0016] By way of example, FIG. 2 illustrates a current waveform 34 generated in response to a sudden short circuit condition when the voltage bus 14 is protected by the SSCB 10 shown in FIG. 1. Prior to t=0 seconds, no current is flowing though load 12 or bus 14 , as the bus 14 is disconnected from load. Then, at t=0 seconds, a short circuit condition is introduced on bus 14 and through SSCB 10 . As is evident from viewing FIG. 2, a large current spike 36 results immediately upon the short circuit condition. Although the graph shown in FIG. 2 only goes up to 70 amperes (A), the actual peak value of the current spike was approximately 81.2 A. After approximately t=8 μs, the fault current drops to a steady state value of approximately 12.5 A, as defined by V 1 REF /R S . Finally, after the overcurrent timer 24 has detected a fault level amount of current for a predetermined period of time, it sends a signal to shutdown latch 30 to completely turn off Q 1 at about t=128 μs. [0017] Because of the inherent delay in the response of the first current sensor 18 , and in particular differential amplifier 20 , the SSCB 10 and voltage bus 14 sustained a current spike of about 81 amperes for a duration of nearly 8 μs, before differential amplifier 20 was able to regulate the fault current at the desired level. This condition is undesirable and can potentially result in damage to the voltage bus 14 or SSCB 10 , as explained earlier. [0018] Accordingly, in response to the aforementioned drawbacks, an improved SSCB 40 in accordance with an embodiment of the invention is shown in FIG. 3. For ease of description, like elements appearing in FIG. 1 and FIG. 3 are shown with the same reference numerals and component designations. In addition to the elements previously described, SSCB 40 further includes a second current sensor 42 having a voltage comparator 44 connected in parallel with differential amplifier 20 . Specifically, voltage comparator 44 has an inverting terminal (−) connected to the inverting terminal (−) of differential amplifier 20 , and an output connected to the input of buffer element 16 . However, voltage comparator 44 has its non-inverting terminal (+) connected to a second reference voltage, V 2 REF , which is approximately twice the value of V 1 REF . Thus configured, voltage comparator 44 is an amplifier which operates in the saturation region. [0019] An inductor, L S , is connected between Q 1 and R S . The inductance value of L S is preferably on the order of about 20 nanohenries (nH), which is roughly equivalent to the inductance of an inch of wire. Accordingly, this inductance value may be attained by appropriately increasing the length of the associated printed circuit board wiring trace. Alternatively, a powered-iron toroid core having a single turn can provide sufficient inductance. Finally, a third current sensor 46 includes bipolar transistor Q 2 having its base terminal connected the source terminal of Q 1 , while the collector of Q 2 is connected to the gate of Q 1 . The emitter of Q 2 is connected to ground so that the gate of Q 1 is pulled to ground whenever Q 2 is switched on. Q 2 is switched on when its base to emitter voltage V BE exceeds a threshold value of approximately 0.7 volts. [0020] With the configuration of the SSCB 40 as shown in FIG. 3, an improved current limiting function is realized. Inductor L s , resisting any sudden changes in current, provides a back electromotive force proportional to the rate of change of current (di/dt). As such, differential amplifier 20 will begin to reduce the gate voltage at Q 1 , even before the current level reaches the programmed threshold, if a sudden increase in current is detected. However, in the event that the rate of current increase exceeds V 2 REF /L S , then the voltage comparator 44 will act more quickly than differential amplifier 20 to adjust the gate voltage at Q 1 and hold the fault current to the desired value. Finally, for yet an even faster rate of current change that exceeds V BE /L S , Q 2 will immediately turn on and pull the gate of Q 1 to ground. [0021] Referring now to FIG. 4, the performance of the SSCB 40 in accordance with the schematic in FIG. 3 is illustrated. Once again, a short circuit condition is introduced into high-voltage bus 14 at t=0 seconds. This time, however, the resulting current spike 48 has peaked at about 16.4 amperes for approximately 2 μs. Immediately thereafter, the current is completely pinched off since the back electromotive force created by the current spike 48 through L S drives V BE of Q 2 to its threshold value, turning Q 2 on and Q 1 off. At approximately t=10 μs, the current begins to rise to the desired fault current level. Because there is no longer a rapid change in current through L S , the voltage thereacross will drop until Q 2 is switched off. At the same time, differential amplifier 20 and/or voltage comparator 44 will have had the opportunity to regulate the input voltage applied to Q 1 for operation in the linear region. Thus, as Q 2 is turned off, Q 1 will turn on again, but will only conduct current to the extent allowed by amplifier 20 . [0022] A smooth rise in current is seen after Q 1 is turned on in its linear region. At about t=28 μs, the current reaches a steady state value of about 12.5 A (again, defined by V 1 REF /R S ), until the overcurrent timer 24 causes the shutdown latch 30 to completely cut off Q 1 at about t=140 μs. [0023] It will readily be appreciated that by adding the second & third current sensors 42 , 46 , while at the same time improving the response performance of the first current sensor 18 with inductor L S , the presently disclosed SSCB 40 provides improved protection against the high current transients associated with severe faults such as short circuit conditions. While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

A solid state circuit breaker is disclosed for use in connection with a voltage bus, the voltage bus supplying electrical current to a load. The solid state circuit breaker includes a current controller for controlling the magnitude of current supplied by the voltage bus. A first current sensor senses the magnitude of the electrical current supplied by the voltage bus, the first current sensor having an output in communication with the current controller. An inductor is included within the first current sensor, the inductor providing a back electromotive force on the voltage bus. The back electromotive force is proportional to the rate of change of current flowing through the voltage bus.

The present invention relates generally to Static Random Access Memory (SRAM) cells, and specifically to SRAM memory cells having improved robustness and reduced size. This application claims priority from U.S. Provisional Patent Application No. 61/129,570, filed Jul. 7, 2008, U.S. Provisional Patent Application No. 61/136,659, filed Sep. 23, 2008, and U.S. Provisional Patent Application No. 61/193,503, filed Dec. 4, 2008. BACKGROUND OF THE INVENTION Static Random Access Memory (SRAM) cells are one of the most popular ways to store data in electronic systems. Accordingly, embedded SRAM cells are vital building blocks in integrated circuits. SRAM cells are popular to implement because they provide high operational speed, robust data storage, and ease of integration. SRAM arrays often occupy a significantly large portion of a chip's die area, making an SRAM cell an important block in terms of area, yield, reliability and power consumption. With increasing demand for highly integrated System on Chip (SoC) design, improving various aspects of embedded SRAM cells has received a significant interest. The most popular SRAM cell configuration is a six transistor (6T) SRAM cell, due largely to its high operational speed and robust data storage. Referring to FIG. 1 a , the 6T SRAM cell is illustrated. The 6T SRAM cell comprises four transistors configured to provide a pair of complementary storage nodes and two dedicated access transistors, each configured to access a corresponding one of the storage nodes. Accordingly, a four transistor (4T) SRAM cell has been developed. Referring to FIG. 1 b , the 4T SRAM cell is illustrated. The 4T SRAM cell comprises two drive transistors configured to provide a pair of complementary storage nodes and two dedicated access transistors, each configured to access a corresponding one of the storage nodes. Although the 4T SRAM cell reduces the space required to implement the SRAM cell, using only two drive transistors results in poor stability. Specifically, in this configuration the stability of the SRAM cell depends on the relative leakage through dedicated access and driver transistors. Therefore, threshold voltage fluctuations of transistors can affect the stability of the cell significantly. In extreme situations, the SRAM cell may lose its data. Although the 6T SRAM cell is the most common memory cell, other cells have been created with the goal of higher stability and robustness. For example, referring to FIG. 10 , a prior art ten-transistor (10T) soft error robust (SER) SRAM cell is shown. When ionizing radiation consisting of energetic cosmic neutrons and alpha particles strike an SRAM cell they generate a large number of electron hole pairs. Depending on the location of the particle strike, the deposited charge may be collected by a node in the SRAM cell. If sufficient charge is collected the SRAM cell can switch its logical state, which is called a soft error. Accordingly, the illustrated circuit comprises eight transistors configured to provide two pairs of complementary storage nodes. The redundant storage nodes provide the 10T SRAM cell with a robustness to soft errors. In addition to the core eight transistors which create the robust storage cell, two dedicated access transistors are provided to couple two of the four nodes in the storage cell to a pair of bitlines (BL and BLB). Yet further, referring to FIG. 16 , a state-of-the-art dual-interlocking storage cell (DICE cell) DICE cell also provides robustness to soft errors. Data is stored on multiple nodes and the DICE cell is immune to single node upsets. However, the DICE cell requires twice as many transistors to implement as the standard 6T SRAM circuit, making it expensive in terms of both area and power. Irrespective of the storage cell which holds the data it is desirable to implement an SRAM cell with a minimal number of transistors while maintaining stability at the storage nodes. SUMMARY OF THE INVENTION A new SRAM cell configuration is introduced. The SRAM cell configuration allows for a variety of storage cells to be accessed with fewer transistors compared with traditional implementations by allowing for data to be written into and read from a storage cell without requiring the use of dedicated access transistors. In accordance with an aspect of the present invention there is provided a Static Random Access Memory (SRAM) cell comprising a plurality of transistors configured to provide at least a pair of storage nodes for storing complementary logic values represented by corresponding voltages, the transistors comprising: at least one bitline transistor configured to selectively couple one of the storage nodes to at least one corresponding bitline, the bitline for being shared by SRAM cells in one of a common row or column; at least one wordline transistor configured to selectively couple another of the storage nodes to at least one corresponding wordline, the wordline for being shared by SRAM cells in the other of the common row or column; and at least two supply transistors configured to selectively couple corresponding ones of the storage nodes to a supply voltage; the bitline transistor being further configured to actively maintain a logic value at the one of the storage nodes and the wordline transistor being further configured to actively maintain a complementary logic value at the other of the storage nodes. In accordance with an aspect of the present invention there is provided a Static Random Access Memory (SRAM) cell comprising a plurality of transistors configured to provide four storage nodes configured as two pairs of complementary storage nodes for storing complementary logic values represented by corresponding voltages, the transistors comprising: two bitline transistors configured to selectively couple a first pair of complementary storage nodes to corresponding bitlines, the bitlines for being shared by SRAM cells in one of a common row or column; two wordline transistors configured to selectively couple a second pair of complementary storage nodes to the corresponding wordlines, the wordlines being shared by SRAM cells in the other of the common row or column; and four supply transistors configured to selectively couple the four storage nodes to a power supply. In accordance with an aspect of the present invention there is provided a Static Random Access Memory (SRAM) cell comprising a plurality of transistors configured to provide four complementary storage nodes as two pairs of complementary storage nodes for storing complementary logic values represented by corresponding voltages, the transistors comprising: two bitline transistors configured to selectively couple two complementary storage nodes to corresponding bitlines, the bitlines for being shared by SRAM cells in one of a common row or column; four wordline transistors configured to selectively couple the remaining two complementary storage nodes to corresponding wordlines, the wordlines shared by SRAM cells in the other of a common row or column; and the two supply transistors coupling corresponding ones of the two complementary storage nodes to the supply voltage. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present invention will now be described by way of example only with reference to the following drawings in which: FIG. 1 a is a schematic diagram of a prior art 6T SRAM cell; FIG. 1 b is a schematic diagram of a prior art 4T SRAM cell; FIG. 2 is a schematic diagram of a 4T SRAM cell in accordance with an embodiment of the present invention; FIG. 3 is a block diagram illustrating an array of 4T SRAM cells; FIG. 4 is a flow chart illustrating a read operation on the 4T SRAM cell; FIG. 5 is a series of simulation waveforms illustrating a read operation when the 4T SRAM stores a logic 1; FIG. 6 is a flow chart illustrating a write operation for writing a logic 0 to the 4T SRAM cell; FIG. 7 is a series of simulation waveforms illustrating the write operation of FIG. 6 ; FIG. 8 is a flow chart illustrating a write operation for writing a logic 1 to the 4T SRAM cell; FIG. 9 is a series of simulation waveforms illustrating the write operation of FIG. 8 ; FIG. 10 is a schematic diagram of a prior art 10T SRAM cell; FIG. 11 is a schematic diagram of an 8T SRAM cell in accordance with an embodiment of the present invention; FIG. 12 is a block diagram illustrating an array of 8T SRAM cells; FIG. 13 is a flow chart illustrating a read operation for the 8T SRAM cell of FIG. 11 . FIG. 14 is a series of simulation waveforms illustrating the read operation of FIG. 13 ; FIG. 15 is a flow chart illustrating a write operation for writing a logic 0 to the 8T SRAM cell; FIG. 16 is a schematic diagram of a prior art DICE SRAM cell; FIG. 17 is a schematic diagram of an 8T DICE SRAM cell in accordance with an embodiment of the present invention; FIGS. 18 a and b are schematic diagrams illustrating the condition of the 8T DICE SRAM cell in static condition; FIG. 19 is a block diagram illustrating an array of 8T DICE SRAM cells; FIG. 20 is a flow chart illustrating a read operation for the 8T DICE SRAM cell of FIG. 17 ; FIG. 21 is a series of simulation waveforms illustrating the read operation of FIG. 20 ; FIG. 22 is a flow chart illustrating a write operation for the 8T DICE SRAM cell; FIG. 23 is a series of simulation waveforms illustrating the write operation of FIG. 22 ; FIG. 24 is a series of simulation waveforms illustrating the write operation of FIG. 22 on a half-selected cell; FIG. 25 is a schematic diagram of a 10T DICE SRAM cell in accordance with an embodiment of the present invention; FIG. 26 a is schematic diagram of a 10T DICE SRAM cell having a read assist circuit in accordance with an embodiment of the invention; FIG. 26 b is schematic diagram of a 10T DICE SRAM cell having an alternate read assist circuit to that shown in FIG. 26 a; FIG. 27 a is a flow chart for the read operation on the cell illustrated in FIG. 26 a; FIG. 27 b is a flow chart for the read operation on the cell illustrated in FIG. 26 b ; and FIG. 28 is a schematic diagram of an alternate configuration for the 8T SRAM illustrated in FIG. 11 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS For convenience, like structures in drawings will be referenced by like numerals in the description. Memory cells are described in which the number of transistors have been reduced in comparison to traditional memory cells by providing direct access to the storage node via the bitlines and wordlines, without requiring dedicated access transistors. The following describes embodiments of memory cells using three different storage cell configurations: the back-to-back inverter storage cell (4T SRAM), the 8T robust storage cell and the 8T DICE storage cell. Referring to FIG. 2 , a 4T SRAM cell in accordance with an embodiment of the present invention is illustrated generally by the numeral 200 . The 4T SRAM cell 200 comprises two re-channel transistors N 1 and N 2 , two p-channel transistors P 1 and P 2 and two internal nodes A and B. Transistors N 1 and P 1 and N 2 and P 2 are connected in a cross-coupled latch configuration. The source terminal of transistor N 1 is connected to a bitline BL while the source terminal of transistor N 2 is connected to a wordline WL. The source terminals of transistors P 1 and P 2 are connected to a nominal supply voltage VDD. Because transistors N 1 and N 2 are coupled to the bitline BL and wordline WL, respectively, they will be referred as line transistors. Because transistors P 1 and P 2 are coupled to the supply voltage VDD, the will be referred to as supply transistors. In the present embodiment, VDD is 1.0V. In steady state, the voltage on the wordline WL and the voltage (V BL ) of the bitline are kept at a low voltage V L . In the present embodiment, V L is approximately 200 mV. Therefore, the SRAM cell 200 is able to retain logic data as long as it is powered. Further, transistor N 1 also acts as an access transistor, connecting the internal node A to the bitline BL if the gate-to-source voltage V GS of transistor N 1 is raised above its threshold voltage V T . Referring to FIG. 3 , a sample array of SRAM cells 200 is illustrated generally by numeral 300 . The array 300 comprises M rows and N columns of SRAM cells 200 . A bitline BL is shared among the cells located in a given column. A wordline WL node is shared among all cells in a given row. In addition to the array 300 , a memory will also contain blocks such as address decoders, timing and control, sensing and column drivers. These blocks are similar to those found in state-of-the-art SRAM configurations, and therefore are not described in detail. Alternatively, the bitline BL may be shared among the cells located in a given row and the wordline WL node may be shared among all cells in a given column. Referring to FIG. 4 , a flow chart illustrating the steps for a read operation is illustrated by numeral 400 . At step 402 , the wordline WL is raised from the low voltage V L to read voltage ΔV 1 . A typical value of the read voltage ΔV 1 is chosen to be higher that the threshold voltage V T of transistor N 1 . In addition the read voltage ΔV 1 , together with transistor sizes, is chosen for ensuring a non-destructive read operation. Finally, the read voltage ΔV 1 is a compromise between the read current and read data stability. At step 404 , the bitline voltage V BL is kept at its nominal value of V L . At step 406 , the voltage stored at internal node A is reflected on the bitline BL. An example of a read operation when a logic 1 is stored in the SRAM cell 200 will be described with reference to the timing diagrams illustrated in FIG. 5 . When storing a logic 1, the voltage at internal node A is “high” and the voltage at internal node B is “low”. As described in step 402 and illustrated in FIG. 5 a , the wordline WL is raised from the low voltage V L to the read voltage ΔV 1 . At step 404 , transistor N 1 turns on. At step 406 , the voltage stored at node A cause an increase in the voltage on the bitline BL, as illustrated in FIG. 5 b . This voltage increase on the bitline BL is interpreted by a sense amplifier (not shown) as a logic 1. Further, referring to FIG. 5 c , although the voltage stored at node A drops and the voltage stored at node B increases, once the wordline WL is returned to the low voltage V L , both nodes A and B return to their pre-read operation voltage levels. Thus, the cell is able to retain its data through the read operation. When the SRAM cell 200 stores a logic 0, the voltage at internal node A is low and the voltage at internal node B is high. Since transistor N 2 is off, raising the voltage of the wordline WL to the read voltage ΔV 1 will not affect the operation of the SRAM cell 200 . Accordingly, with transistor N 1 switched on, the bitline voltage V BL remains at approximately V L , which is interpreted by a sense amplifier (not shown) as a logic 0. Further, since the voltages at nodes A and B do not significantly differ during the read operation, the cell is able to retain its data. FIG. 5 d illustrates the effect of a read operation on the storage nodes in cells 200 in the same column as the target cell 200 , but in a different row. As expected, since these cells 200 do not share a common wordline WL with the target cell 200 , there is no effect on the node voltages throughout the read operation. Similarly, FIG. 5 e illustrates the effect of a read operation on the storage node in cells 200 in a different row and different column as the target cell 200 . By contrast, FIG. 5 f illustrates the effect of a read operation on the storage nodes in cells 200 in the same row as the target cell, but in a different column. As expected, since these cells 200 share a wordline WL with the target cell 200 , the voltage at storage node A drops slightly and the voltage at storage node B increases close to the read voltage ΔV 1 . However, since the cells are in a different column from the target cell, the corresponding sense amplifier is not activated and the voltage change on the bitline BL is not recorded. Once the read operation is complete, both nodes A and B return to their pre-read operation voltage levels. Thus, the cell is able to retain its data through the read operation. Referring to FIG. 6 , a flow chart illustrating the steps for writing a logic 0 to the SRAM cell 200 is illustrated by numeral 600 . It is assumed that node A has high voltage V H and node B has low voltage V L . At step 602 , the bitline voltage V BL is pulled down from the low voltage V L to the ground potential (0V). At step 604 , the wordline WL voltage is raised from the low voltage V L to a write voltage ΔV 2 . Similar to the read operation, the value of the write voltage ΔV 2 is chosen such that the gate-to-source voltage V GS of transistor N 1 is higher than its threshold voltage V T . Simulation shows that a write voltage ΔV 2 of 0.4V is sufficient to write a logic 0 into the cell. A higher value for the write voltage ΔV 2 , such as the 0.6V used for the read voltage ΔV 1 , will also facilitate the logic 0 write operation. At step 606 , transistor N 1 turns on. Further, the absolute value of gate-to-source voltage V GS of transistor P 1 is reduced while the absolute voltage of gate-to-source voltage V GS of transistor P 2 is increased. Because of the reduction of the gate-to-source voltage V GS of transistor P 1 and increase of the gate-to-source voltage V GS of transistor P 2 , the static noise margin of the SRAM cell 200 is reduced significantly. Accordingly, at step 608 transistor P 1 turns off, node A is pulled down to ground, transistor P 2 is turned on and transistor N 2 is turned off. Thus, the SRAM cell 200 is overwritten with a logic 0. At step 610 , the wordline WL is reduced to its nominal voltage V L while the bitline voltage V BL is increased to its nominal value of V L . An example of writing a logic 0 to the SRAM cell 200 will be described with reference to the timing diagrams illustrated in FIG. 7 . As shown in FIG. 7 a , the wordline WL voltage is raised to the write voltage ΔV 2 . As shown in FIG. 7 b , the bitline voltage V BL is pulled down to ground potential (0V). As shown in FIG. 7 c , the voltages stored at nodes A and B are inversed and the cell has gone from storing a logic 1 to storing a logic 0. FIG. 7 d illustrate the effect of the write operation on the storage nodes in cells 200 in the same column as the target cell 200 , but in a different row. As expected, since these cells 200 do not share a common wordline WL with the target cell 200 , there is no effect on the node voltages throughout the write operation. Similarly, FIG. 7 e illustrates the effect of the write operation on the storage node in cells 200 in a different row and different column as the target cell 200 . By contrast, FIG. 7 f illustrates the effect of a write operation on the storage nodes in cells 200 in the same row as the target cell, but in a different column. As expected, since these cells 200 share a common wordline WL with the target cell 200 , the voltage at storage node A drops slightly and the voltage at storage node B increases close to the read voltage ΔV 1 . However, since the cells are in a different column from the target cell 200 , the corresponding bitlines BL are not pulled down to ground potential. Once the write operation is complete, both nodes A and B return to their pre-read operation voltage levels. Thus, the cell is able to retain its data through the write operation. Similarly, a logic 1 can also be written into the SRAM cell 200 . Referring to FIG. 8 , a flow chart illustrating the steps for writing a logic 1 to the SRAM cell 200 is illustrated by numeral 800 . It is assumed that node A has a low voltage V L and node B has a high voltage V H . At step 802 , the bitline voltage V BL is pulled up from the low voltage V L to write voltage ΔV 3 which is high enough voltage to write logic 1. In the present embodiment, the write voltage is 0.5V, although other voltages may be used, as will be appreciated by a person of ordinary skill in the art. At step 804 , the wordline WL voltage is lowered from the low voltage V L to the ground potential. This leads to an increase in the gate-to-source voltage V GS of transistor N 2 while the gate-to-source voltage V GS of N 1 transistor is reduced. In this fashion, the static noise margin of the cell is reduced significantly, and the cell is overwritten with logic 1. Accordingly, at step 806 transistor N 2 turns on, node B is pulled down to ground, transistor N 1 is turned off and transistor P 1 is turned on, and transistor P 2 is turned off. Thus, the SRAM cell 200 is overwritten with a logic 1. At step 808 , the wordline WL is increased to its nominal voltage V L while the bitline voltage V BL is reduced to its nominal value of V L . An example of writing a logic 1 to the SRAM cell 200 will be described with reference to the timing diagrams illustrated in FIG. 9 . As shown in FIG. 9 a , the wordline WL voltage is pulled down to ground potential. As shown in FIG. 9 b , the bitline voltage V BL is increased to a write voltage ΔV 3 or 0.5V. As shown in FIG. 9 c , the voltages stored at nodes A and B are inversed and the cell has gone from storing a logic 0 to storing a logic 1. FIG. 9 d illustrate the effect of the write operation on the storage nodes in cells 200 in the same column as the target cell 200 , but in a different row. As expected, since these cells 200 do not share a common wordline WL with the target cell 200 , there is no effect on the node voltages throughout the write operation. Similarly, FIG. 6 e illustrates the effect of the write operation on the storage node in cells 200 in a different row and different column as the target cell 200 . By contrast, FIG. 9 f illustrates the effect of a read operation on the storage nodes in cells 200 in the same row as the target cell, but in a different column. As expected, since these cells 200 share a common wordline WL with the target cell 200 , the voltage at storage node B drops slightly. However, since the cells are in a different column from the target cell 200 , the corresponding bitlines BL are not pulled up to the write voltage ΔV 3 . Accordingly, once the write operation is complete, both nodes A and B return to their pre-read operation voltage levels. Thus, the cell is able to retain its data through the write operation. Referring to FIG. 11 , an eight-transistor (8T) SER SRAM cell in accordance with an embodiment of the invention is illustrated generally by numeral 1100 . The configuration of the 8T SER CELL 1100 is similar to the 10T SER cell shown in FIG. 10 , with the exception that it does not require the use of dedicated access transistors. Accordingly, the proposed 8T SER SRAM cell 1100 cell provides the stability and SER robustness of the 10T SRAM cell but uses fewer transistors. The 8T SER SRAM cell 1100 comprises four NMOS transistors N 1 , N 2 , N 3 , N 4 and four PMOS transistors P 1 , P 2 , P 3 , P 4 . As is standard in the art, the 8T SER SRAM cell 1100 is connected in a quad-latch configuration. The configuration also provides four storage nodes A, B, C, D, which interlock. The storage nodes A, B, C, D are used to store two complementary states. Nodes A and C store one logical value and nodes B and D store the complementary logical value. Transistors P 1 , P 2 , P 3 , P 4 are supply transistors and are coupled at their source to a power supply VDD. Transistors N 1 and N 2 are line transistors and coupled at their respective sources to one of a differential bitline pair BL and BLB. Transistors N 3 and N 4 are line transistors and are both coupled at their source to a wordline WL. The 8T SRAM cell 1100 is accessed differentially using two transistors N 1 and N 2 . The source of the two cross-coupled NMOS transistors N 3 and N 4 is controlled in order to turn on transistors N 1 and N 2 and enable read and write operations. Accordingly, as will be explained below, the 8T SER SRAM cell 1100 is able retain logic data in a similar fashion to the 10 SER SRAM cell so long as it is powered. Referring to FIG. 12 , a sample array of SRAM cells 1100 is illustrated generally by numeral 1200 . The array 1200 comprises M rows and N columns of SRAM cells 1100 . A bitline pair BL and BLB is shared among the cells located in a given column. A wordline WL is shared among all cells in a given row. In addition to the array 1200 , a memory will also contain blocks such as address decoders, timing and control, sensing and column drivers. These blocks are similar to those found in state-of-the-art SRAM configurations, and therefore are not described in detail. Alternatively, the bitline pair BL and BLB may be shared among the cells located in a given row and the wordline WL may be shared among all cells in a given column. Referring to FIG. 13 the read operation on the 8T SRAM cell 1100 is illustrated generally by numeral 1300 . In the present embodiment, it is assumed that the supply voltage VDD is 1V, the initial voltage at nodes A and C is 1V value and the initial voltage at nodes B and D is 0V. Thus, the cell 1100 stores a logic 1. At step 1302 , the differential bitline pair BL and BLB are pre-charged to 0V and the allowed to float. At step 1304 , the wordline WL voltage is raised to a read voltage ΔV 4 value which is greater than the threshold voltage of transistors N 1 and N 2 . In this embodiment, the read voltage ΔV 4 is 0.4V. As the wordline WL voltage is raised, the voltage at node B is also raised to 0.4V. The read voltage ΔV 4 , together with transistor sizes, are chosen for ensuring a non-destructive read operation. Finally, in the present embodiment, the read voltage ΔV 4 is a compromise between the read current and read data stability. At step 1306 , the increased voltage at node B causes transistor N 1 to be weakly turned on. At step 1308 , current flows from the supply, through transistors P 1 and N 1 and onto the bitline BL. At step 1310 , the current flowing into the bitline BL, or the resulting voltage increase, is sensed by a sense amplifier (not shown). Since the cell is differential, the read operation will be similar when the stored value is reversed and the initial voltage at nodes A and C is 0V value and the initial voltage at nodes B and D is 1V. However, in such an embodiment node C would be raised to 0.4V, which would result in transistor N 2 being weakly turned on. This, in turn, would result in a current flowing onto the bitline BLB. That it will be appreciated the logic state of a cell can be read by determining which of the bitline pair BL or BLB is determined to have an increased current activity. An example of a read operation when a logic 1 is stored in the 8T SRAM cell 1100 will be described with reference to the timing diagrams illustrated in FIG. 14 . As illustrated in FIG. 14 a , a column select signal activates a corresponding bitline pair BL and BLB by pulling them to ground and allowing the signals to float. As illustrated in FIG. 14 c , the wordline WL is increased to the read voltage ΔV 4 . Accordingly, as illustrated in FIG. 14 d , the voltage at node B also increases to the read voltage ΔV 4 , which turns on transistor N 1 . FIG. 14 b illustrates the differential voltage across the bitline pair BL and BLB detected by the sense amplifier. Referring to FIG. 15 , a flow chart illustrating the steps for writing a logic 0 to the 8T SRAM cell 1100 is illustrated by numeral 1500 . In this example, a logic 1 is stored in the 8T SRAM cell 1100 so the initial voltage at nodes A and C is 1V and that the initial voltage at nodes B and D is 0V. At step 1502 the bitline pair is set so that bitline BL is set to 0V and bitline BLB is set to 1V. At step 1504 , the voltage on the wordline WL is increased to a write voltage ΔV 5 . The write voltage ΔV 5 is greater than the threshold voltage of the NMOS transistors N 1 , N 2 , N 3 , N 4 , which is 0.4V in this example. As the WL voltage increases, the voltage at node B also increases 0.4V. At step 1506 , the increased voltage at node B causes transistor N 1 to be weakly turned on. At step 1508 , since the bitline BL signal is 0V, node A will discharge through transistor N 1 . Node C is not affected by the increase in the wordline WL voltage, staying at 1V and keeping transistor N 2 fully on. Since the bitline BLB is at 1V and transistor N 2 is on, at step 1510 the voltage at node D begins charging up from 0V. At step 1512 , the voltage at node D has increased to the point where the gate-to-source voltage Vgs of transistor N 2 is less than its threshold voltage Vt, in this example approximately 0.6V, and transistor N 2 turns off. By this time nodes A and D have been sufficiently changed to low and high voltages respectively, that the internal feedback of the 8T SRAM cell 1100 takes over and, at step 1514 completes the process by changing nodes B and C to high and low voltages, respectively. At step 1516 , the bitline pair BL and BLB are returned to their nominal voltages and the write to the 8T SRAM cell 1100 is complete. Since the cell is differential, writing a logic 1 to an 8T SRAM cell 1100 storing a logic 0 operates in a similar fashion to that described with reference to FIG. 15 . However, in this example, the initial voltage at nodes A and C is 0V and that the initial voltage at nodes B and D is 1V. Accordingly, in order to write a logic 1 the bitline pair is set so that bitline BL is set to 1V and bitline BLB is set to 0V. Thus, when the voltage of the wordline WL is increased to the write voltage ΔV 5 , the bitline BL charges node A and the bitline BLB discharges node D, partially flipping the cell. The internal feedback takes over and completes the flip and hence the logic 1 is written. Accordingly, the 8T SRAM cell 1100 reduces the number of transistors required for a traditional SER cell. Further, the 8T SRAM 1100 is also robust to soft-errors. In the present example, the 8T SRAM cell stores a logic 0, 1, 0, 1 at nodes A, B, C, D, respectively. Accordingly, transistors N 1 , P 3 , N 4 , and P 2 are on and transistors N 2 , P 1 , N 3 and P 4 are off. If a particle strike were to strike node A and cause the state of node A to flip to a logical 1 state, transistors P 2 and P 3 would turn off. However, this does not result in any other node changing state. Node B is still at logical state 1 and hence transistor N 1 is still on. This means that in time node A will discharge and the cell will return to its original state. The concepts described above with reference to the 4T SRAM Cell 200 and the 8T SER SRAM cell 1100 can further be applied to a state-of-the-art dual-interlocking storage cell (DICE cell), illustrated in FIG. 16 . As is know in the prior art, the DICE cell has a further improved robustness to soft errors. Data is stored on multiple nodes and the DICE cell is immune to single node upsets. However, the DICE cell requires twice as many transistors to implement as the standard 6T SRAM circuit, making it expensive in terms of both area and power. Accordingly, as illustrated in FIG. 17 , an 8T DICE SRAM cell in accordance with the present embodiment is illustrated generally by numeral 1700 . The core of the 8T DICE SRAM cell is similar to the state-of-the-art DICE SRAM cell. Specifically, the 8T DICE SRAM cell comprises four NMOS transistors N 1 , N 2 , N 3 and N 4 and four PMOS transistors P 1 , P 2 , P 3 and P 4 , which are connected such that they form four internal nodes A, B, C, D. The internal nodes A, B, C, D are used to store two complementary states. Nodes A and C store the same logical value and nodes B and D store the same logic value. The logic value stored at nodes A and C are complementary to the logic value stored at nodes B and D. In the static condition the DICE cell can be view as two independent half latches, as shown in FIGS. 18 a and 18 b . As shown in FIG. 18 a , if the cell stores a logic 1, 0, 1, 0 at nodes A, B, C, D, then transistors N 4 and P 1 form one half-latch and transistors N 2 and P 3 form another half-latch. Transistors N 1 , P 2 , N 3 , and P 4 are turned off. As shown in FIG. 18 b , if the cell stores a logic 0, 1, 0, 1 at nodes A, B, C, D, then transistors N 1 and P 2 form one half-latch and transistors N 3 and P 4 form another half-latch. Transistors N 2 , P 1 , N 4 , and P 3 are turned off. In both examples, the latches store the data independently, and it is difficult, if not impossible, to write into both nodes of either half-latch by corrupting only one node. Moreover, the half-latches are regenerative, such that if any single node is corrupted the cell will recover the original data in time. However, the 8T DICE SRAM cell 1700 differs from the prior art implementation in that it also comprises bitline pair BL and BLB and wordline pair WL+ and WL− coupled directly to the 8T DICE SRAM, thereby eliminating the need for dedicated access transistors. Rather, transistors P 1 and P 4 are supply transistors and are coupled at their source to the power supply VDD. Transistors P 2 and P 3 are line transistors and are coupled at their source to the wordline WL+. Transistors N 1 and N 4 are line transistors and each is coupled at its source to a corresponding one of the bitline pair BL and BLB, respectively. Transistors N 2 and N 3 are line transistors and are coupled at their source to the wordline WL−. Referring to FIG. 19 , a sample array of 8T DICE SRAM cells 1700 is illustrated generally by numeral 1900 . The array 1900 comprises M rows and N columns of 8T DICE SRAM cells 1700 . A bitline pair BL and BLB is shared among the cells located in a given column. A wordline pair WL+ and WL− is shared among all cells in a given row. In addition to the array 1900 , a memory will also contain blocks such as address decoders, timing and control, sensing and column drivers. These blocks are similar to those found in state-of-the-art SRAM cells, and therefore are not described in detail. Alternatively, the bitline pair BL and BLB may be shared among the cells located in a given row and the wordline pair WL+ and WL− may be shared among all cells in a given column. The row and column signal can be switched for all arrays described herein. In another embodiment, bitline pair BL and BLB, and wordline WL+ may be shared among cells in a column while wordline WL− is shared among the cells in a row. Referring to FIG. 20 , a flow chart illustrating a read operation for the 8T DICE SRAM cell 1700 is illustrated generally by numeral 2000 . At step 2002 , the bitline BL is pre-charged to ground potential (0V), the bitline BLB is coupled to ground potential (0V) and the wordline WL+ is connected to the supply voltage VDD. At step 2004 , the read operation is enabled by raising the voltage on the wordline WL− to a read voltage ΔV 6 . The read voltage ΔV 6 is greater than the threshold voltage of the NMOS transistors. In this example ΔV 6 is set to 0.5V, however it would be possible to have a different implementation with a different voltage ΔV 6 . If the state of node A is a logic 1, then at step 2006 the increased voltage on node B causes transistor N 1 to be weakly turned on. At step 2008 current flows from the supply voltage VDD, through transistors P 1 and N 1 and onto the bitline BL. At step 2010 , this current, or the resulting voltage increase on BL, can be sensed by a sense amplifier (not shown) and determined to be logic 1. If the state of node A is ‘0’ then at step 2012 no current flows through transistor N 1 and the voltage on BL remains constant. In this case, at step 2014 , the output of the sense amplifier can be determined to be logic 0. Referring to FIGS. 21 a and 21 b , a series of timing diagrams illustrates the read operation for sensing logic 1 and a logic 0, respectively. As illustrated, raising the bitline WL− enables the read operation. As illustrated in FIG. 21 a , the increase in voltage on bitline BL indicates logic 1. As illustrated in FIG. 21 b , there is no increase in the voltage on bitline BL, which indicates a logic 0. Referring to FIG. 22 , a flow chart illustrating a write operation for the 8T DICE SRAM cell 1700 is illustrated generally by numeral 2200 . At step 2202 , the wordline pair WL+ and WL− are connected to a common voltage. In this example the common voltage is VDD/2 however in other implementations a different common voltage could be applied to WL+ and WL−. This sufficiently weakens the cell 1700 to enable a write operation by limiting the ability of nodes B and C to affect the state of nodes A and D. At step 2204 , the appropriate different data is driven on the bitline pair BL and BLB. That is, in the present embodiment, the supply voltage VDD is applied to bitline BL and ground potential is applied to BLB for a logic 1, and vice versa for a logic 0. These voltages are able to change the state of nodes A and D. Once the states of nodes A and D are changed, the write event propagates to nodes B and C. Finally, at Step 2206 , the bitlines BL and BLB are returned to the ground potential, wordline WL− is also connected to ground, and wordline WL+ is re-connected to the supply voltage VDD. Once the write operation is complete the 8T DICE SRAM cell 1700 holds the new data and returns to the static condition. In addition to the flow chart, the write operation is shown by a series of simulation waveforms illustrated in FIG. 23 . Accordingly, in the present embodiment, in order to write to the 8T DICE SRAM cell 1700 , both the bitline pair BL and BLB and the wordline pair WL+ and WL− are enabled. If only one of the bitline pair or the wordline pair is enabled it is referred to as a half-selected cell. The affect of the write operation on a half-selected cell is shown by a series of simulation waveforms illustrated in FIG. 24 . As illustrated, data is not written into a cell which is half-selected. Accordingly, it will be appreciated that the 8T DICE SRAM cell 1700 reduces the number of transistors required to implement a cell. Further, the 8T SRAM DICE cell 1700 is robust to soft errors. For example, consider a particle strike on node A. In this example, the initial logical state at nodes A and C is 0 and that the initial logical state at nodes B and D is 1. Initially transistors N 1 , P 2 , N 3 , and P 4 are on, and transistors N 2 , P 1 , N 4 and P 3 are off. The charge collected by the particle strike causes the state of node A to flip, such that it is now at a logical 1 state. This has the effect of turning off transistors P 2 and turning on transistor N 4 . Turning on transistor N 4 will cause node D to change state from 1 to 0. At this point the error can propagate no further. N 1 eventually overpowers P 1 , returning node A to zero. This in turn turns off N 4 , node D returns to ‘1’, and the cell has recovered. If the error occurs on node B the situation is similar. Node B flips from state 1 to state 0. This causes P 3 to turn on and N 1 to turn off. If P 3 can overpower N 3 then node C will change state to 1. At this point, the error can propagate no further and the cell returns to the original state. Referring to FIG. 25 , an alternate embodiment of the 8T DICE SRAM cell 1700 is illustrated. In the present embodiment, a 10T DICE SRAM cell 2500 is provided. The 10T DICE SRAM cell 2500 is similar to the 8T DICE SRAM cell 1700 , with the addition of a read assist circuit 2502 . The read assist circuit 2502 comprises a pair of transistors and is configured to improve the read time of the 8T DICE SRAM cell 1700 . Accordingly, it will be appreciated that the improved speed comes at the cost of additional transistors. It will also be appreciated that the use of a read assist circuit to improve the speed of the read operation can be applied to other embodiments, as desired. Referring to FIG. 26 a , one embodiment of the read assist circuit 2502 is illustrated. In the present embodiment, the read assist circuit 2502 comprises one NMOS transistor N READ and one PMOS transistor P READ coupled in series. The source of transistor P READ is coupled to the power supply VDD and the source of transistor N READ is an output signal out. Transistor P READ is gated by node D and transistor N READ is gated by a read enable signal RE. Accordingly, referring to FIG. 27 a , a flow chart illustrating the read operation of the 10T DICE SRAM cell 2500 having a read assist circuit as described with reference to FIG. 26 a is illustrated generally by numeral 2700 . At step 2702 , output signal out is precharged to ground potential and the read enable signal RE is turned on. In the present embodiment, the 10 DICE SRAM cell 2500 is defined as holding a logic 1 if nodes A, B, C, D hold a 1, 0, 1, 0, respectively. Therefore, if the 10T DICE SRAM cell 2500 holds a logic 1 then at step 2704 the voltage at the output signal out will increase. If, however, the 10T DICE SRAM cell 2500 holds a logic 0 then at step 2706 the output signal out will remain at ground potential. It will be appreciated that transistor P READ can be gated by any one of nodes A, B, C or D. However, it should be noted that what represent a logic 1 depends on which node is used. For example, node B will yield similar results to node D. However, if either of nodes A and C are used to gate P READ , the output signal out will increase if the 10T DICE SRAM cell 2500 holds a logic 0 and remain at ground potential if it holds a logic 1. Referring to FIG. 26 b , an alternate embodiment of the read assist circuit 2502 is illustrated by numeral 2502 ′. In the present embodiment, the read assist circuit 2502 ′ comprises one NMOS transistor N READ and one PMOS transistor P READ coupled in series. The source of transistor N READ is coupled to ground potential and the source of transistor P READ is the output signal out. Transistor N READ is gated by node D and transistor P READ is gated by a read enable signal RE. Accordingly, referring to FIG. 27 b , a flow chart illustrating the read operation of the 10T DICE SRAM cell 2500 having a read assist circuit as described with reference to FIG. 26 b is illustrated generally by numeral 2710 . At step 2712 , output signal out is precharged to the supply voltage VDD and the read enable signal RE is turned on. In the present embodiment, the 10 DICE SRAM cell 2500 is defined as holding a logic 1 if nodes A, B, C, D hold a 1, 0, 1, 0, respectively. Therefore, if the 10T DICE SRAM cell 2500 holds a logic 1 then at step 2714 the voltage at the output signal out remains at the supply voltage VDD. If, however, the 10T DICE SRAM cell 2500 holds a logic 0 then at step 2716 the output signal out is pulled to ground potential. Similar to the previous embodiment, it will be appreciated that transistor N READ can be gated by any one of nodes A, B, C or D. However, it should be noted that what represents a logic 1 depends on which node is used. For example, node B will yield similar results to node D. However, if either of nodes A and C are used to gate N READ , the output signal out will remain the same if the 10T DICE SRAM cell 2500 holds a logic 0 and get pulled to ground potential if it holds a logic 1. Both of the embodiments described above provide the same number of NMOS and PMOS transistors, which can be beneficial for circuit layout. However, this need not be the case. For example, in yet an alternate embodiment the read assist circuit 2502 comprises two NMOS transistors N 1 READ and N 2 READ coupled in series. The source of transistor N 1 READ is coupled to ground potential and the drain of transistor N 2 READ is the output signal out. Transistor N 1 READ is gated by one of the nodes of the 10T DICE SRAM cell 2500 and transistor N 2 READ is gated by the read enable signal RE, or vice versa. The output signal out is precharged to the supply voltage VDD. In yet an alternate embodiment the read assist circuit 2502 comprises two PMOS transistors P 1 READ and P 2 READ coupled in series. The source of transistor P 1 READ is coupled to the supply voltage VDD and the drain of transistor P 2 READ is the output signal out. Transistor P 1 READ is gated by one of the nodes of the 10T DICE SRAM cell 2500 and transistor P 2 READ is gated by the read enable signal RE, or vice versa. The output signal out is precharged to the ground potential. The previous embodiments describe the storage nodes as being coupled to the bitline or wordline through the NMOS transistors and to the power supply through the PMOS transistors. However, it will be appreciated that because of the symmetry of the cells, the opposite is also possible. That is, the storage nodes can be coupled to either the bitline or the wordline through the PMOS transistors and to the power supply through the NMOS transistors. Referring to FIG. 28 , an 8T SRAM cell similar to the one described in FIG. 11 is illustrated generally by numeral 2800 . As illustrated, the storage nodes A, B, C and D are coupled to power supply VSS via transistors N 1 , N 3 , N 4 and N 2 , respectively. Further, the storage nodes A and D are coupled to the wordline WL via transistors P 1 and P 2 , respectively. Storage node B is coupled to bitline BL via transistor P 3 and storage node C is coupled to bitline BLB via transistor P 4 . In the present embodiment, VSS is 0V. Although only the 8T SRAM cell is illustrated, it will be appreciated by a person of ordinary skill in the art that other embodiments can also be implemented in this manner. Further, although the previous embodiments have been described with a particular configuration of storage node voltages for logic 1 and complementary voltages for logic 0, it will be appreciated that the inverse may also be the case. That is, a storage node configuration described as logic 1 could, instead, be defined as logic 0, and vice versa. Accordingly, it will be appreciated that all of the embodiments described above provide examples of an SRAM memory cell having fewer transistors than tradition implementation, thereby improving cell size. Further, reducing the number of transistors by removing the dedicated access transistors allows the core configuration of the storage nodes to remain the same, thereby providing a minimal difference in reliability. Further, although preferred embodiments of the invention have been described herein, it will be understood by those skilled in the art that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.

A Static Random Access Memory (SRAM) cell without dedicated access transistors is described. The SRAM cell comprises a plurality of transistors configured to provide at least a pair of storage nodes for storing complementary logic values represented by corresponding voltages. The transistors comprise at least one bitline transistor, at least on wordline transistor and at least two supply transistors. The bitline transistor is configured to selectively couple one of the storage nodes to at least one corresponding bitline, the bitline for being shared by SRAM cells in one of a common row or column. The wordline transistor is configured to selectively couple another of the storage nodes to at least one corresponding wordline, the wordline for being shared by SRAM cells in the other of the common row or column. The supply transistors are configured to selectively couple corresponding ones of the storage nodes to a supply voltage.

CROSS REFERENCE TO RELATED APPLICATIONS This application is the United States national stage filing of corresponding international application number PCT/EP2004/051190, filed on Jun. 22, 2004, which claims priority to and benefit of European Application No. 03425436.7, filed on Jul. 1, 2003, each of which is hereby incorporated herein by reference. FIELD An algorithm for projecting information data belonging to a multidimensional space into a space having fewer dimensions, a method for the cognitive analysis of multidimensional information data based on said algorithm, a program comprising said algorithm stored on a recordable support, and an apparatus having artificial intelligence. The invention relates to an algorithm for projecting information data belonging to a multidimensional space into a space having fewer dimensions. The invention relates particularly to the field of artificial intelligence and the aim is to allow a machine able to carry out computational tasks to analyze complex n-dimensional data in order to represent these data in a two or three dimensional space and so to evaluate these data for cognitive tasks, for example to create a simplified and representable image of the data or to evaluate the existence of relationships between a group of data records, which relationships cannot be represented by exact computable or mathematical functions or for computational tasks, in order to solve a problem, which is not based on exact mathematical functions. BACKGROUND As it is known, nature cannot be always represented by functions having an exact solution or by a system of equations having a mathematical solution. In the exact sciences a model may be constructed for simplifying the relationships and helping the mathematical inspection to be carried out in order to achieve a mathematical representation of the relationships between data or a correlation among data appearing as not correlated, and a mathematical tool for evaluating the degree or level of the correlation of the data. Furthermore the models may consist in recognizing and constructing images or structures and provide for a graphic representation. Further to the problem of having tools for apparati having artificial intelligence, in order to better understand, classify and evaluate the physical or chemical world and nature, it has to be noted that artificial intelligence is not limited to the analysis and inspection of nature only relatively to exact scientific or technical problems or structures but must be also confronted with social problems which are far most difficult to be represented by the mathematical tools or by exact computable functions. In this case, the apparatus is confronted with individuals having a specific behavior and acting on their own mind or by means of reactions to instincts, which actions cannot be described by mathematical models because there is no mathematical model and also because there is no clear and univocal rule defining the relations between events whichever kind they are and the behavior. Human beings have the capacity of analyzing environmental stimuli and deciding to carry out an action as a response to said stimuli also when apparently the stimuli have no relationship among them or are not correlated. This process is carried out sometimes in a non-conscious way giving rise to logically non-predictable actions if considering the known relationship of the stimuli if one ever exists. Nevertheless the action is often correct or approximately correct or leads to a certain successful effect. Such kind of behavior which we can define as intuition or the like seems not to have any logical basis or seems not to be caused by a logical thought. Since artificial intelligence is based on computational machines there is the need of instruments which may help these machines to analyze or transform information data in such a way as to be simply handled and used by the machine and in such a way as to allow the machine to recognize and/or generate relationship functions which are easier to handle from the mathematical or computational point of view without distorting or leaving information and giving thus the opportunity to simulate at least at a certain degree the “intuitive” behavior of the human intelligence. Records of a database may be represented as points in a space, the position of the points being determined by variables values which describes the records of the database. In principle the representation may also be reversed in the sense that the variables are represented as points in a space, while the position of each variable is defined by the records. This projection brings certain advantages. As a first technical advantage, certain relationship may be discovered which were hidden in the n-dimensional space of the information data being not intelligible either by human beings nor by machines, since the relative position of the records and/or of the variables in the space where the records or the variables are represented by points is a measure of their similarity or difference. A second technical advantage is that the simplifying of the information data helps in transforming the data in data which may subjected to a computational evaluation and thus to help the machine to analyze the data to determine an appropriate response to the data and to carrying out its computational job in a more rapid and simple way. One might not forget that for mathematical or computational problems there might be theoretically a solution, which cannot be computed in practice. The solution of a mapping problem allowing to reduce a three dimensional space for the data in a two dimensional space without losing or distorting the information represented by the data has also a great relevance if one considers for example a machine, which collects image data from the environment and which has to generate an image recognizing the objects or at least discriminating certain objects between objects constituting obstacles and objects which do not constitute obstacles and also between objects that might constitute obstacles at a later time. In this case a machine which has the possibility of reducing information about physical objects placed in a three dimensional space and which have a three dimensional extension in a two dimensional map would allow to dramatically simplify the machine construction and to dramatically reduce the computational burden. The above described technical advantages are present already if one considers non humanoid machines having artificial intelligence. Considering for example humanoid machines such like humanoid robots, the advantages become more important since such a machine has a large number of sensors and a very high computing and evaluation burden is sent to the processing units. The algorithm to which the present invention relates has not only relevance for artificial intelligence, but can also help human intelligence in inspecting and analyzing the relationships between information data belonging to a n-dimensional space, where n is bigger then 3 by projecting the data onto a two or three dimensional space. This is a representation which can be understood by human intelligence having its senses constructed to sense a three dimensional or two dimensional space. Thus a representation of data in this space can help human intelligence to understand and find out relationships which could be not be recognized in a four or more dimensional space. A known algorithm for projecting data from a n-dimensional space into a less dimensional space, and particularly onto a three or two dimensional space, uses a predetermined characteristic projection function for computing the position of each point in the projection space. An example for such kind of projection algorithm is the so called Principal Component Analysis, briefly PCA which is described in H. Hotelling “Analysis of a Complex of Statistical Variables into Principal Components” J. Educ. Psychol., 24:498-520, 1933. This algorithm provides the steps of defining N factors and N new variables which are orthogonal. Using this base of new variables a reorganisation of the data is carried out by attempting to put as much information as possible in the first factors under the constraint of linearity. The mapping consist in rewriting the observations/variables using the computed factors and in plotting each one on a two dimensional map using as coordinates the computed factors F 1 /F 2 , F 3 /F 4 and so on. This kind of projection algorithm working only on the base of linear projections determines that some information will be lost during the projection. In order to understand this situation consider a normal projection from a three dimensional space onto a two dimensional space. In a linear projections two points having a certain distance along one of the three dimensions might appear very near if the two dimensional projection space is perpendicular to the third dimension along which the two points are spaced apart. In a very simplified manner this situation takes place using a PCA algorithm. The result of the known technique is that, in the less dimensional space where the information data has been projected, the data relationships is distorted in a dramatic way and the distortion can go so far as to cancel or abnormally enhance relationships between data. SUMMARY The algorithm according to the present invention has the aim of projecting N-dimensional information data onto a less dimensional, particularly onto a two or three dimensional space without distorting in an excessive manner the relationships between the data. The algorithm according to the present invention has the following steps: Providing a database of N-dimensional data in the form of records having a certain number of variables; Defining a metric function for calculating a distance between each record of the database; Calculating a matrix of distances between each record of the database by means of the metric function defined at the previous step; Defining a n−1 dimensional space in which each record is defined by n−1 coordinates; Calculating the n−1 coordinates of each record in the n−1 dimensional space by means of an evolutionary algorithm; Defining as the best projection of the records onto the n−1 dimensional space the projection, in which the distance matrix of the records in the n−1 dimensional space best fits or has minimum differences with the distance matrix of the records calculated in the n-dimensional space. As evolutionary algorithms so called genetic algorithms may be used. Such kind of algorithm provides new solutions based on a starting parent population of solutions, which may be computed according to various ways such as for example casual attempts. The solutions of the parent populations are combined in a way that follows the basic combination of genes in genetics, thus giving new and different solutions, in which a fitness score, for example in this case the error or difference from the distance matrices of the n- and the n−1-dimensional spaces, is evaluated for giving a certain relevance to the solution, which will influence the possibility of combination with other solutions of the new generation for generating a further generation. This kind of computation makes use of an evolutionary algorithm in order to compute the position of the points in the projection space in such a way to minimize the error with respect to the distances of the points in the original space and is always independent on the specific structure of the information data. Thus, contrary to the PCA algorithm of the state of the art the algorithm according to the present invention does not use a predetermined characteristic projection function which computes the position of the points in the projection space. The algorithm according to the present invention combines the projection of the information data with a particular evolutionary algorithm, which will be described with greater detail in the following description of the examples. More in detail and referred for simplicity to a projection into a two dimensional space, the mathematical problem which the present algorithm solves is the following: Given N points and their distances in a L dimensional space, find into a 2 dimensional space the optimal distribution of these points according to the matrix of their constrained distances. In strict mathematical language the above mentioned problem may be expressed as follows: Defining a Map Distance in the two dimensional space such as for example: Md j = ( Px i - Px j ) 2 + ( Py i - Py j ) 2 3 Where Md is the map distance and i and j are the number of the points and where Px and Py are the coordinates of the point in the two dimensional space. Defining also a Vector Distance such as Vd i ⁢ ⁢ j = ∑ k = 1 L ⁢  P ⁢ ⁢ v i ⁢ ⁢ k - P ⁢ ⁢ v j ⁢ ⁢ k  Where Vd is the vector distance i and j are the indices of the different points and v k are the vector components. Thus the mathematical problem is to carry out the following optimization: min ⁢ ⁢ E ; E = 1 C · ∑ i = 1 N - 1 ⁢ ∑ j = i + 1 N ⁢  Md i ⁢ ⁢ j - Vd i ⁢ ⁢ j  ; C = N · ( N - 1 ) 2 Due to the reduction of the number of dimensions in the projection, there might be a situation in which two points might not be separated one from the other if the projection is carried out in a classical way. Thus no exact projection can be carried out from the mathematical point of view if information has to be not distorted or maintained at least partially in the less dimensional space. The present algorithm solves the above problem by encoding each individual record represented by a point having coordinate X and Y. A set of different X and Y coordinates for each point is defined forming a first population of projections onto the less dimensional space, usually a two or three dimensional space. For each of the projections of this first population, the fitness score is calculated by using as the fitness function the matrix of distances of the single points in the originally N dimensional space. The population of projections is then subjected to combination according to the combination rules of the genetic algorithm thus producing a first generation population of projections which comprises X and Y coordinates for the points which are a combination of the coordinates provided in two projections of the parent generation. The fitness score of the projections of the first generation is evaluated and again a new generation is formed based on the first generation. Using certain combinatory criteria of the projections of the parent generation based on the fitness score of this parent generation, the genetic algorithm at each generation, calculates the solution having a better fitness scores thus converging against the best solution. Several genetic or evolutionary algorithm are known, which differ one from the other mostly in the combinatory criteria of the parents in order to generate the next generation of solutions. This criteria relates to the admitted or forbidden “marriages” of two individuals of the parent population and in the mechanism with which the two parents individuals combine their set of data, in this case the different coordinates of the points in the less dimensional map. As an example a particular genetic algorithm used according to the invention is the so called Genetic Doping Algorithm disclosed in detail in BUSCEMA, 2000: M. Buscema, Genetic Doping Algorithm GenD), Edizioni Semeion, Technical Paper 22e, Rome 2000 and Massimo Buscema & Semeion Group “Reti neurali artificiali e sistemi sociali complessi”, Year 1999, Edizioni Franco Angeli s.r.l. Milano, Italy, chapter 21, which disclosures are considered to be part of the present specification. Briefly summarized, the GenD algorithm provides for special modified rules for generating the new individuals of a following generation from the parents population. As usual in the genetic algorithm, as a first step, GenD calculates the fitness score of each individual, depending on the function that requires optimisation, in this case the distribution function of the data records in the general data set onto the training set and the testing set. The average health score of the entire population is then computed. Average health constitutes the criterion firstly of vulnerability, and secondly of recombination, of all the individuals of the population, for each generation. All individuals whose health is lower than or equal to the average health of the population are entered in a vulnerability list. This individuals are not eliminated, but continue to take part in the process being only marked out. The number of vulnerable individuals automatically establishes the maximum number of marriages permitted for that generation. The number of possible marriages for each generation thus varies according to the average health of the population. At the third step GenD algorithm couples the individuals. The entire population participate to this possibility. The maximum number of random coupling calls corresponds to half the number of individuals marked out as vulnerable. For coupling purposes and the generation of children both the candidate individuals must have a fitness value close to the average fitness value of the entire population. Furthermore each couple of individuals may generate off-springs since it is sufficient for marriage that at least one of the two individuals of the couple enjoy health values close to the health average of the entire population or even higher. According to another recombination rule GenD algorithm does not consider possible marriages between two individuals of which one has a very low health value and the other a very high health value in comparison to the average health value of the population. This means that too weak individuals and too healthy individuals tend not to marry themselves. Recombination by coupling does not mean classic crossover of the genes of the parents individuals. GenD algorithm effects selective combination of the parents genes by means of two types of recombination; a logic crossover; when repetitions are allowed and an opportunistic crossover; when repetitions are not allowed. The logic crossover considers four cases: 1. Health of the father and mother are greater than average health of the entire population; 2. Health of both parents is lower than the average health of the entire population; b 3. and 4. The Health of one of the parents is less than the average health, while the health of the other of the parents is greater than the average health of the entire population. If the case 1 does occur than recombination will be effected with a traditional crossover. If the second case occurs, than the generation of the two children occurs through the rejection of parent's genes. If case 3 or 4 occur, than the genes of the more healthy parent are transmitted to the children, while the genes of the less healthy parent are rejected. In the above the definition of rejection does not mean that the rejected genes are cancelled but only that these genes are substituted. Genes substitution is not random but is carried out by means of a sliding window criterion. Each gene may have different genetic options or states. In this case substitution by a sliding window means that the actual rejected gene will be substituted by the same gene but having another state as the original one. So during substitution the criterion used by the GenD algorithm provide only the substitution of the state of that gene which assumes a different state as the gene had in the parent individual. Relating to the opportunistic crossover, this crossover works when repetition are not allowed. In this case the parents have overlapping genes with respect to a random crossover point. In this case an offspring is generated selecting the more effective gene of the parents. The mechanism is repeated until all the off-springs are completed. A further criterion of the GenD algorithm rely upon a final opportunity criterion which is a mechanism that enables weak individuals being marked out and having never had the opportunity to be part of a marriage to re-enter the coupling mechanism thanks to a mutation. The number of possible mutations is calculated as the difference of the number of potential marriages and the number of marriages carried out. Mutations occur to those individuals which are present and marked out in the vulnerability list. In this way individuals that had never the opportunity to be part of a generation process are given a final opportunity to enter the evolutionary process. From the above short explanation of the principal features of this special genetic algorithm, it appears clearly that in the GenD algorithm the number of marriages and of mutations are not external parameters, but adaptive self-definable internal variables, taking into account the global tendencies of the population system. Furthermore, it appears also clearly that the basic unit of the GenD algorithm is not the individual, unlike the classic Genetic Algorithm, but the species, which acts on the evolution of individuals in the form of the average health of the entire population of each generation. The feedback loop between individuals and the average health of the population enables the present algorithm to transform in evolution terms the population as a whole from a list of individuals into a dynamic system of individuals. As a further improvement step of the algorithm according to the present invention, a so called hidden point may be defined. This hidden point whose existence is only guessed is added in the parent population by giving to it position coordinates X hi and Y hi in the projection. The calculation of the evolutionary algorithm may be carried out in parallel with the hidden point and without the hidden point and the best fit projections obtained by the two parallel calculations may be compared. Hidden points might help in better appreciating the peculiarities of the real positions of the points in the N-dimensional space and so better approximate these positions in the less dimensional projection. FIG. 1 summarizes briefly the mechanism of the present algorithm relatively to the evaluation with and without the hidden unit. Although the example has been described in relation to a projection from a L dimensional space into a two dimensional space, it is clear that the algorithm works similarly also from projections in a three dimensional space or in a L−1 dimensional space. Usually the projections in a two or three dimensional space are the preferred ones since the data representation can be better understood by human beings. When using the present invention for giving more cognitive capacity to apparati provided with artificial intelligence, also four or more dimensional spaces can be used if it is needed for carrying out the tasks for which the apparatus has been designed. The projection carried out with the present algorithm may be on a Euclidean two or three dimensional space. Alternatively the way the algorithm calculates the projection might be understood as projecting the points for example not in a two dimensional plane but on a two dimensional surface, which is somehow curved and nevertheless represented graphically on a plane. Given a certain database comprising a certain number of records each one characterized by a certain number of variables, the present algorithm might be applied for projecting the database in two different ways. A first way is to consider the records as being points and the variables as being the coordinates of the points. The second way is symmetrically reverse this situation by considering the records as variables. The two spaces are defined as observation and variable spaces and the projections can bring to discovering relations between records and/or between variables. In the following description of different examples it will be possible to appreciate the effectiveness of the present algorithm and the information which might be recovered by means of the hidden point and also by means of the two projections. From the specific examples the technical meaning of the present algorithm will also appear clearly, which goes beyond the fact of allowing to calculate in a very rapid way the less dimensional map of the points in a fully independent way from the structure and meaning of the information data represented by each point or record. In the field of artificial intelligence and thus, for example, robotics, this technical meaning resides in the fact that a computational machine may be able to analyze information data and to recognize or define relationships despite their complexity. The recognitions of relationships of information data in complex problems are important for giving the machine not only computational power but also allowing the machine to take decisions relating the particular tasks the machine is destined to carry out. The algorithm according to the present invention can be used for providing a method for the cognitive analysis of multidimensional information data. After providing a database comprising a certain number of records each one representing the relationship between one feature and a certain number of variables, a distance matrix of the records in the N-dimensional space defined by the number of variables characterizing each record is calculated according to a certain metric function. This matrix is taken as the fitness matrix for the projection of the records or the variables into a less dimensional space, particularly a two or three dimensional space using the algorithm described above. The representation of the records or of the variables in a two or three dimensional space may be used for recognizing certain relationships among the records or among the variables. An example of a particular problem to which the present method can be applied relates to the fact of determining the structure of a certain molecule when distances between at least some atoms forming the molecules are known. This problem is of the kind so called not bound optimization problem. The method can calculate a three or two dimensional projection of the structure of the molecule which may be graphically represented in an intelligible way for human beings. Furthermore relating to this problem when analyzing complex molecules, the projection can be carried out by adding the hidden individual, which in this case could be a hidden atom and thus offering a tool for inspecting molecular composition and structures of highly complex molecules. The method according to the present invention being independent on the structure of the information data can handle also non-mathematical problems such as for example sociological problems. A first step of giving a numeric scale of evaluation of the different social variables considered might be provided in this case. Normally this is not a critical problem since such kind of variables often are characterized by different states, which can be defined by the value true, not true and not present so that the scale in this case could be defined as 1, (−1), and 0. According to a further feature of the method, the algorithm according to the present invention, used for projecting the information data from the N-dimensional space onto a less dimensional space, particularly a two or three dimensional space, may be applied in combination with other kind of projection algorithms, which are somehow more sensitive to the information data structure. A particular algorithm which can be used in combination with the present projection algorithm is the so called “SOM” Self Organizing Map) algorithm which is a clustering algorithm. The SOM is a known algorithm which is described in more details in KOHONEN, 1995: T. Kohonen, Self Organising Maps, Springer Verlag, Berlin, Heidelberg 1995 or Massimo Buscema & Semeion Group “Reti neurali artificiali e sistemi sociali complessi”, Year 1999, Edizioni Franco Angeli s.r.l. Milano, Italy, chapter 12. SOM assumes a prior definition of the projection grid and projects codebooks of records in this grid via a competitive algorithm where dominant variables prevail over others. The SOM projections gives rise to data clusters, so called Kohonen units. The SOM algorithm is thus used to perform a first elaboration of the information data, while the algorithm according to the present invention is then used to reproject the Kohonen units emerging from the first elaboration in a coordinated and more detailed manner on its own map. This procedure allows to take advantage of the peculiarity of the SOM algorithm to consider the significance of the variables and to take also advantage of the features of the present projection algorithm, which can evaluate the fitness score of the projection performed by referring to the fitness function which is the distance matrix of the points representing the information data in the N-dimensional space and which can also consider hidden units. Thus the reproduction accuracy in the less dimensional space is ensured and a more complex projection, which can provide for greater information, is performed. FIG. 2 schematically illustrates the combination of SOM algorithm with the present algorithm. Thanks to the present algorithm the advantages of the SOM algorithm are combined with the fact that the present algorithm can dynamically deform the original projections space by hidden units increasing the reconstruction accuracy of the projection. The invention relates also to a method for constructing two or three dimensional structural images of molecules starting from complete or incomplete data about the distances of the atoms of the molecule. The invention relates also to a machine having artificial intelligence which is able to carry out actions based on processes simulating the “intuitive” reasoning of human intelligence when subjected to apparently not correlated data of non chemical or physical nature and/or collected physical or chemical data from the environment. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a diagram of the architecture of the projection algorithm according to the present invention. FIG. 2 illustrates a diagram of the combination of the algorithm according to the present invention with a SOM algorithm. FIG. 3 is a database of highway distances between Italian cities according to example I. FIG. 4 is the two dimensional projection map of the cities of the database according to the database of FIG. 3 . FIG. 5 is a database of flight distances between US cities according to example II. FIG. 6 is the two dimensional projection map of the cities of the database according to the database of FIG. 5 . FIG. 7 is a database of the European Countries Food Consumption in 1994 according to example III FIG. 8 is the two dimensional diagram of the projection of database of FIG. 7 in the variable space which has been elaborated by the algorithm according to the present invention. FIG. 9 is the two dimensional diagram of the projection of database of FIG. 7 in the observation space which has been elaborated by the algorithm according to the present invention. FIG. 10 is a table of 13 variables and their complement of a fourth example. FIG. 11 is the result of the projection of the variables according to the table of FIG. 10 on a two dimensional plane with the algorithm according to the invention. FIG. 12 illustrates the connection between the variables and the complements on the map according to FIG. 1 . FIG. 13 illustrates a fifth method according to the present invention in which the projection algorithm is used in combination with a so called Self Organizing Map. FIG. 14 is a further diagram illustrating the method according to FIG. 14 and the table of codebooks prototypes of the groups of variables defined by the projection of the database on the two dimensional map. FIG. 15 is a block diagram of an apparatus according to the invention having artificial intelligence. FIG. 16 is a graphic representation of an extremely simplified example of a situation where the apparatus having artificial intelligence, for example a robot, according to the invention can provide a correct response action. FIGS. 17 to 19 illustrate an example of the method according to the present invention for generating two or three dimensional images of the structure of a molecule form incomplete data of the distance of the atoms forming said molecule. DETAILED DESCRIPTION Example I Example I clarifies the way the algorithm operates in order to generate a map from data relating to distances between objects. In FIGS. 3 and 4 there is described a first example of dataset and two dimensional mapping using the algorithm according to the present invention. A dataset comprising ten Italian cities and their highway distances is provided. The highway distances are not true two dimensional distances in an Euclidean Space, since every highway distance has three kind of alteration namely: a longitudinal alteration, an altitude alteration and a structural alteration. Thus creating a two dimensional map of the cities where the cities are placed considering only the highway distances using a linear algorithm would determine a distortion of the position of the cities with respect to their real relative position. The city of Arezzo is not given to the algorithm with its distances from the other cities, but free determinable distances values are given to the algorithm so that the algorithm is called to look for a hidden city of which the existence is assumed and of witch the position is not known. A first randomized distance value of the hidden city can be given in the distance matrix for the hidden city so that the algorithm can be initialised and can start to correct the randomized initial position of the hidden city. As it appears clearly from FIG. 4 a comparison of the map drawn by the algorithm according to the invention with a geographical map allows to identify the hidden city as the city of Arezzo. Using the algorithm according to the present invention which carries out a non linear projection also the other cities being defined by their distances in the database are placed onto the two dimensional map by optimising their relative position with respect to the matrices of their relative distances. The distortion relative to the real position is very low and the solution is illustrated in FIG. 4 . Example II Example II is a similar mapping problem as example I. In this case the database comprises twelve US cities and their relative flight distances. No hidden unit has been provided. Also in this case the flight distances are affected by alterations similar to example I. Also in this case a linear projection of the cities onto a two dimensional map would not take correctly care of the above mentioned alterations and the position of the cities on the map would be distorted relatively to reality. The result obtained by the present algorithm is a map which is illustrated in FIG. 6 and where the positioning of the cities has an error of only 3.07% with respect to the matrix of distances while the positions of the cities is very close to the real geographical position. Example III Example III is a more complex one. This example clarifies how the algorithm works in order to generate relations or correlations among data which apparently have no logical relationship. The database relates to the European Countries Food Consumption in nineteen ninety four. It comprises nine variables relating to the food kind, namely: cereals, rice, potatoes, sugar, vegetables, meat, milk, butter, eggs. Sixteen observations where made relating to sixteen countries, namely: Belgium, Denmark, Germany, Greece, Spain, France, Ireland, Italy, Netherlands, Portugal, Great Britain, Austria, Finland, Island, Norway, Sweden. The database was evaluated with the algorithm according to the present invention and the map according to FIG. 8 was obtained. In the two dimensional map the circles indicates geographical areas to which the countries belong. The projection carried out by the present algorithm has shown that there are different groups of countries having similar food consumption and which countries belong to the same geographical area. Furthermore, the two dimensional projection has also highlighted that Ireland has a food consumption behaviour which is very different from that of all the other countries and particularly from the countries of the geographical area to which it belongs. FIG. 9 illustrates the projection of the database made by considering the records as variables, i.e. the observation countries as variables which has been defined as the observation space. The projection was also carried out by means of the algorithm according to the present invention and the map of FIG. 9 indicates also a relation which was not apparent from the database. From the above it appears clearly that the algorithm according to the present invention carries out a projection which due to its non linearity does not lead to hidden information. The PCA algorithm needs to illustrate the information data onto two different maps for not losing information, while the projection according to the present algorithm does not hide information and relationships between the data. Entering more in detail, the degree of correlation between data is established by the present algorithm by means of a so called “share information” equation. This equation sizes the degree of association between two points in the map. This equation expresses the “share information” between two points representing two different data records of a database in the original multidimensional space in term of probability. Thus the present method defines the degree of association between two pints in the map as a probability of association: A ij = ∑ k = 1 L ⁢ ( 1 - P ⁢ ⁢ v i , k ) · P ⁢ ⁢ v j , k L · ∑ k = 1 L ⁢ ( 1 - P ⁢ ⁢ v j , k ) · P ⁢ ⁢ v i , k L ∑ k = 1 L ⁢ P ⁢ ⁢ v j , k · P ⁢ ⁢ v i , k L · ∑ k = 1 L ⁢ ( 1 - P ⁢ ⁢ v j , k ) · ( 1 - P ⁢ ⁢ v i , k ) L ⁢ P ⁢ ⁢ v ∈ [ 0 , 1 ] ⁢ A ∈ [ - ∞ , + ∞ ] Returning to the capability of the present mapping algorithm in finding out hidden units this capability can be used for solving further technical problems as for example for drawing two or three dimensional maps of complex molecules also in the case where the list of atoms is incomplete or where the matrix of the distances is incomplete. It has to be noticed that as disclosed above, the database can also be incomplete, this means that despite knowing the presence of certain atoms the distances of this ones may not be known. Thanks to the ability of considering hidden units the algorithm according to the present invention can place the known atom of which the distances where not known in the distance matrix in a correct or most probable position relatively to the other atoms of the molecule. According to another way of using the capability of considering hidden units relating to this last example, the algorithm according to the present invention is also capable of considering the presence of unknown atoms in a molecule of which the composition is not completely known and further to this the algorithm is also capable of producing an hypothesis about the most probable position of this atom relatively to the other known atoms thus helping the further study of the molecular structure. Example IV In FIG. 10 the table of 13 variables and their complement is illustrated. The 13 variables relates to anagraphic data and medical data of a certain number of individuals, more precisely of 117 individuals. The aim is to analyse the database in order to find out relations which are somehow connected to the Alzheimer disease or to the probability of developing the Alzheimer disease. Starting from the 13 variables the complement of this variables are defined. The complement being a complementary value of the variables. Using the aforementioned database the data has been projected onto a two dimensional plane. The result is illustrated in FIG. 11 . From this map the following conclusion can be drawn: The more two variables are nearest, more their information is high and therefore the two variables are similar. In FIG. 12 the connection lines between each variable on the map and each complementary variable has been drawn in order to establish their relative distance. From the mathematical point of view it can be demonstrated that the more the connecting segment is long the more the variable is significative in the database since his standardized variance is bigger. Example V FIG. 13 illustrates a diagram of a combined projection algorithm comprising two different algorithm one of which is a projection algorithm according to the present invention. A database of different variables for a certain number of individuals comprises 19 variables of medical, anagraphical and social kind. The records of the database are elaborated with an algorithm known as Self Organising Map (SOM). This algorithm clusters the records into cells or units The database is an enlarge version of the one of Example IV. The algorithm according to the present invention is applied to the units computed by the SOM in order to distribute said units and the records clustered in it in an optimal way on a two dimensional map. Codebooks prototypes can be computed as the average of the codebooks of each unit taking part to a group. The groups of units on the two dimensional map created by the projection algorithm are evaluated by means of their clustering on the map. It appears evident that the projection algorithm according to the invention will stress the existence of a fourth group. FIG. 14 illustrates a diagram in which starting form the database comprising said 19 variables and subjecting the database to the SOM and afterwards to the projection algorithm four groups are generated on the projection map each group having is specific codebooks prototypes which are listed on the right table. The variables considered are variables which can be involved in some way with the Alzheimer disease. The number of subjects considered has been of 117 patients. The different groups are characterised by different percentage of patients having developed the Alzheimer disease. The codebooks prototypes can give insight in the relevance of certain medial variables and/or certain anagraphic variables and/or certain social variables for determining the risk of developing the Alzheimer disease by an individuum. It is interesting to notice that the age is not relevant while social variables such as intellectual level or level of schooling, physical exercise and other variables attaining to the behaviour has a high influence in differentiating the four groups and thus the risk of developing Alzheimer disease. With increasing level of schooling and/or with increasing level of physical exercise and with increasing educational and cultural level the percentage of individual having developed the disease becomes lower, despite the presence of certain pathological variables or medical variables which seems not to be relevant for differentiating the groups one from the other. From the above mentioned projection different suggestion may be extrapolated: Alzheimer disease at histological level starts independently from Tangles in Hippocampus or Plaques in NeoCortex, and arrives to Tangles in NeoCortex passing through Plaques in Hippocampus with different transition probabilities. This suggestion is supported by evidences coming from the projection algorithm according to the present invention and SOM Systems. Severe Braak Stages are related to two different and unrelated pathologies (evidences supported by SOM System). Plaques in NeoCortex and Tangles in Hippocampus distribution are connected with two different kind of subjects in SOM System MMSE, ADL, BOSTON, and CNPR are strongly connected among them, in the same way that WRCL and VRBF are connected to each other. Evidences supported by the mapping through the projection algorithm according to the present invention which puts these two groups of tests in two different areas. Education Years are strongly connected with the Alzheimer disease pathology features (evidences supported by the algorithm according to the present invention). The integrated use of different Unsupervised Organisms, allows the identification of four natural clusters of subjects with specific codebooks prototype. Example VI Example VI relates to a method for determining the conformation of a molecule of which the distance at least of certain of the atoms form at least other atoms forming the molecule are known. In this case the method uses an algorithm according to the present invention for generating a map of the molecules which has the best fit in accordance to the known distances. Thus a structure of the molecule can be drawn which does not lose, hide or distort information. A database is formed which database comprises as variables the distances of the atoms from another atom of the molecule. The database is illustrated as a matrix in FIG. 17 . This database can be obtained by means of measurements carried out on the molecule as for example using radiographic inspection which is a common technique in Solid state physics for determining the lattice structure of crystals or other current measurement means. Once data has been achieved from the measurements, a database is generated in the form of a matrix were each row and each column having identical row and column index identify an atom. The distances between each couple of atoms each one identified by row and column index are listed in the matrix and the result is a matrix where the diagonal elements have each one zero value and which is symmetric relatively to said diagonal. Were no data about the relative distance between two atoms is present a predefined value is given to the matrix elements. In the example the value (−1) has been chosen. As a next step the algorithm according to the invention and to the previous description for generating a map either in a two dimensional or in a three dimensional space is applied to the database. The results are shown in FIGS. 18 e 19 , respectively for the two and for the three dimensional map. In several experiments a fitness score and an error of the generated maps relatively to the experimental data in the database of the measured distances has been calculated. Fitness scores in the range of 0.96 to 0.98 has been reached. Relating to the error, two kinds of errors has been computed according to the below listed equations: ERROR 1 being defined as ∑ i ⁢ abs ⁡ ( DistI i - DistR i ) and ERROR 2 being defined as ∑ i ⁢ abs ⁡ ( DistI i - DistR i ) DistR i were ERROR 1 is the sum of the absolute value of the difference of the euclidean distances in the computed map DistI j and the measured distances of the database DistR j and were ERROR2 is the sum of the absolute values of difference of the percentual error of the euclidean distances in the computed map DistI j relatively to the measured distances of the database DistR j . It has to be noticed that any variant of the algorithm described above also in combination with different examples can be used. In the present case the drawing of two dimensional or three dimensional molecular maps, these means the relative location as a projection in a two dimensional or in a three dimensional space, of the atoms of a molecule is a problem which is analogous to the one of drawing a geographical map described in the previous examples. Starting from this reasoning a further improvement of the method for determining the structure of a molecule can also provide the steps of defining one or more virtual or hypothetic atoms hereinafter indicated as hidden atoms, which might exist in the structure of the molecule but have not been determined experimentally. This further step or improvement is analogous of the one of the hidden city in the mapping example, were the city of AREZZO was introduced in the database without giving any distance value from other cities. Thus carrying out the method according to the present example, the algorithm will consider this one or more atoms and indicate them in the map. The hidden atoms can be highlighted in the structural map of the molecule determined by the present method. As a result the method will provide for a prediction of the coordinates and/or of the distances of this one or more hidden atoms in the structure of the molecule form the other atoms and the results can be used for deeper and more specific experimental inspections and structural analysis of the molecule which are aimed to verify the real existence of this one or more predicted hidden atoms. From this point of view the present method is thus alternatively also a method for carrying out an analysis of the structure of a molecule and for predicting the existence of further atoms in the molecule. Please consider that the virtual molecule of the example has only 25 atoms which is a very low number of atoms if one considers organic chemistry or biochemistry were very big macromolecules are studied which have a much greater number of atoms. From a general point of view the method for determining the structure of a molecule or a geographic map or for inspecting the structure of a molecule or a geographic map in order to investigate about the presence of a further “hidden” element and to predict its position relatively to the other known elements of the structure of the molecule or of a map can be considered as a general method for generating maps and or a general method for predicting the existence of an hypothetical element of the map which is not apparent and which position relatively to the other elements is not known. A further example of this method supporting its general principle is the generation of sky maps or star maps and the prediction of the existence of a star or another astronomical object and its position relatively to other astronomical objects based on data relating to the relative distances of a certain number of stars or other astronomical objects. This kind of inspection avoid complex computations based on the observations, measurements and evaluations of orbital perturbations of objects and can give a first indication about the probability of the presence of an astronomical object which cannot be seen or is hidden. The present invention relates also to an apparatus having artificial intelligence being capable of evaluating data which cannot be considered having a relation or correlation and for providing a reaction behavior to environmental stimuli which is similar to the human intuition processes. As already described, environmental data may not show a direct or explicit correlation or relation. So these data and the corresponding reaction to them of a machine having artificial intelligence may not be computable or evaluated by said machine causing the machine to enter a state of inactivity or blocking the machine. Nevertheless human beings are capable of evaluating these apparently not correlated stimuli by determining in any case a reaction to them which might be either passive or active. If one considers machines having artificial intelligence such as robots or the like which have to interact with an ambient not being created or adapted for them (for example by eliminating unnecessary stimuli for the tasks these machines have to carry out), then the skill of the robots has to increase dramatically in evaluating incoming stimuli which are disordered and which apparently have no relation or no immediate recognizable relation among them and further to the evaluation in determining which reaction has to be carried out as a response to the collected stimuli. Thus a capacity of the machine or robot to simulate a sort of “intuitive” behaviour of human beings can be of great technical importance. The apparatus according to the present invention is illustrated in FIG. 15 and comprises a processing unit 1 . The processing unit can be similar to a conventional computer for the parts relating to the electronics. The housing is formed in this case by at least part of the case or of the body of the apparatus. The processing unit is associated to a memory 2 for a program running the apparatus, which program is carried out by the processing unit. A further memory 3 is provided for data which may be configuration data of the apparatus relating to input and output devices and to actuators or functional operating units or tools with which the apparatus is equipped and which are all driven by the processing unit 1 . The input devices can be of different kind and are summarised by the box 4 in FIG. 15 . Input devices may be different relatively to the tasks the apparatus is designed for. So in a very improved robotized apparatus such as an humanoid robot, the input device can be sensors interacting with physical and chemical stimuli such as any kind of mechanical, electric, acoustic electromagnetic or chemical stimulus. The number and kind of such sensors may vary depending on the conditions in which the apparatus has to operate. Other input devices can be provided such as input interfaces as a keyboard or reader for portable memory devices, on which data is saved which cannot be sensed directly by the apparatus by means of its sensors. The program saved in the program memory 2 has a plurality of routines or sections each one dedicated for carrying out a certain task and a plurality of routines for driving the actuators or operating devices or units and also routines for collecting the data acquired by the sensors and feeding said data to an evaluation routine. If one considers a highly improved apparatus having artificial intelligence, such as a robot which must have the capacity of carrying out basic functions simulating a human being, than considering the simple situation of such an apparatus passing in a street with a normal conditions of traffic, it can be understood that the number of stimuli to which the apparatus is subjected are very high and that conditions may be present in which two stimuli of different kind having the same origin will arrive to the sensors of the apparatus in a condition in which the relation of having the same origin is not immediately or explicitly recognizable. FIG. 16 explains this condition graphically. Consider two vehicles A and B having a parallel path (indicated by the arrows 10 , 11 ) considering a reflecting barrier on one side of the paths such as buildings 12 , 13 or the like and considering also that a robotized apparatus 15 is located on the opposite side of the vehicles path as referred to the reflecting barrier. The apparatus has two visual sensors 115 , such as two cameras and two acoustic sensors 215 such as microphones. This provides for collecting three dimensional image information and three dimensional acoustic information. The acoustic waves generated and represented by the circles will arrive directly to the apparatus as acoustic stimuli indicated by the arrows 16 and 17 . These stimuli will also arrive in the form of reflected acoustic waves as indicated by the arrow 18 , furthermore the direct and reflected acoustic waves of the two vehicles will also superpose or mix up. In this condition the input data collected by the robotized apparatus 15 will provide a certain number of variables, the relation of which is not immediately and directly apparent. Thus forming a database in which the records consist in the collected input data and carrying out the mapping algorithm according to the present invention as described before would provide a map in which the vicinity of the mapped data in the map would give to the apparatus a measure of the relation of the data one with respect to the other. Thus the apparatus is able to correctly relate the acoustic stimuli and the visual stimuli by recognizing which sound is to be associated to the vehicle A and which sound is to be associated to the vehicle B. This is evaluation step provided by the algorithm according to the invention is an analogous process as explained in the examples III, IV and V. Furthermore considering the fact that reflected acoustic waves can be interpreted as a source of acoustic waves, by providing a hidden acoustic wave generator in the database, and using the algorithm of the present invention, the apparatus will be able to determine a map in which the reflectors are identified and their position and movement can be evaluated and also their relationship to the acoustic stimuli attaining to the reflected waves. Combining the mapping with the measure of relation, it could be also possible for the apparatus to identify to which one of the vehicles A or B the major component of the reflected wave has to be referred. Thus applying the method according to the present invention in the form of an algorithm which is coded in a program which is executable by a processing unit of an apparatus having artificial intelligence allows in the example described above to identify a relation between visual or image stimuli and acoustic stimuli, which relation was not directly recognizable from the stimuli sensed by the apparatus. Although if constructing an appropriate model the above example could be solved by an equation describing the process based on the physical laws, it has to be understood that these ways of solving the problem need at least an approximated a priori knowledge of the conditions of the ambient on which the model has to be constructed, which is a very hard limitation. Furthermore in increasing the number of stimuli the problem might not be treated anymore by exact physical functions since with a very large number of variables an exact solvable computational problem may become not solvable. The apparatus according to the present invention includes at least a processing unit 1 and a program memory 2 , in which a program consisting in the present algorithm is saved for being carried out by the processing unit 1 , so as to provide for a data processing method according to the present invention, and would in any case avoid an a priori knowledge of the conditions of the ambient in which the apparatus is located and would obviate the necessity of generating exact mathematical models describing situations to which the apparatus may be subjected. Furthermore it would give the apparatus a possibility to operate also when it is subjected to a high number of stimuli. The processing unit carries out the algorithm according to the present invention in the form of an executable program and generates the output map and the vicinity values as parameters related to the shared information as defined in the above description of the preceding examples. This output is evaluated and used as input for decisional programs which drive the functions of the actuators of the apparatus. It is also possible to provide learning programs for saving the event as experience of the apparatus, thus refining the further computational tasks.

An algorithm for projecting information data belonging to a multidimensional space into a space having fewer dimensions, a method for the cognitive analysis of multidimensional information data based on said algorithm, and a program comprising said algorithm stored on a recordable support. An algorithm for projecting information data belonging to a multidimensional space into a space having fewer dimensions including the following steps: Providing a database of N-dimensional data in the form of records having a certain number of variables; Defining a metric function for calculating a distance between each record of the database; Calculating a matrix of distances between each record of the database by means of the metric function defined at the previous step; Defining a n−1 dimensional space in which each record is defined by n−1 coordinates; Calculating the n−1 coordinates of each record in the n−1 dimensional space by means of an evolutionary algorithm; Defining as the best projection of the records onto the n−1 dimensional space the projection in which the distance matrix of the records in the n−1 dimensional space best fits or has minimum differences with the distance matrix of the records calculated in the n-dimensional space. The method and the program apply the aforementioned algorithm.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention relates to a method of removing organic-containing materials such as photoresists, high temperature organic layers, and organic dielectric materials from a substrate surface of a flat panel display or solar cell array or other large scale substrate (a substrate which is typically larger than about 0.5 meter by 0.5 meter). [0003] 2. Brief Description of the Background Art [0004] The information in this Background Art portion of the application is provided so that the reader of the application can better understand the invention which is described subsequently. The presence of information in this Background Art portion of the application is not an admission that the information presented or a that a combination of the information presented is prior art to the invention. [0005] The fabrication of electronic device structures is complicated by the number of different materials which are used, both to provide the elements of the functional device, and as temporary process structures during fabrication of the device. Since most of the devices involve the formation of layers of inter-related, intricate, patterned structures, photoresists and high temperature organic masking materials are commonly used during patterning of underlying layers of material which are present over large area (typically about 0.25 m 2 or greater) surfaces. A patterned photoresist is one of the temporary processing structures and must be removed once work on the underlying structure through openings in the photoresist is completed. Therefore, there is a need for an efficient and inexpensive method of removing, stripping, or cleaning of organic photoresists, as well as other organic layer residues, from large substrate surfaces. Due to the varying composition of a substrate underlying a photoresist, for example, it is important that a method used to remove the photoresist not be reactive with (corrosive to) surfaces underlying the photoresist. One problem has been the presence of metallic materials and the tendency of these materials to oxidize and dissolve the oxidized layer. [0006] To be useful in processing of large surface areas, it is helpful to have the stripping and cleaning material be a non-corrosive fluid. The fluid should be minimally affected by the presence of an ambient atmospheric condition. It is also helpful when the removal process can be carried out at room temperature, or at least below about 80° C. Finally, it is always desirable that the fluid used for removal of the organic material be environmentally friendly. [0007] In order to remove an organic material such as a photoresist for example, and specifically to strip photoresist from large substrate surfaces, a number of techniques have been used. Representative techniques for removing photoresists, as well as their advantages and disadvantages, are described below. [0008] A Piranha solution, which consists of sulfuric acid (H 2 SO 4 ) and hydrogen peroxide (H 2 O 2 ), typically in a volumetric ratio of 4:1, works well for photoresist removal, but cannot be used on substrate surfaces which include exposed metal, because it will etch the metal. Also, because it is very viscous, the Piranha solution is difficult to rinse off a substrate surface after a photoresist removal process. Further, the H 2 SO 4 H 2 O 2 solution cannot be recovered or re-used many times, as it decomposes rapidly. Finally, the solution needs to be applied at relatively high temperatures of at least 70° C., and typically about 120° C. [0009] Several other techniques for removal of organic photoresists are based on the use of organic solvent-based strippers, such as monoethanolamine (MEA), dimethylsulfoxide (DMSO), n-methylpyrrolidone (NMP), propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate, and methylethylketone (MEK). Unlike the Piranha solution, these organic solvent strippers can be used when metals are present. However, these organic solvent strippers cannot be easily recovered after saturation with dissolved photoresist, because the photoresist is difficult to separate from the organic solvent. Therefore, the saturated organic solvent strippers must be disposed of, creating an environmental problem, or recovered for recycling using a distillation technique which is cumbersome and expensive. Like the Piranha solution, these solvents are typically heated prior to use, but to somewhat lower temperatures than the Piranha solution, typically around 50-65° C. [0010] Japanese Patent Publication No. 59125760, of Tanno et al., published Jan. 10, 1986, describes dissolving ozone in an organic acid (such as formic acid or acetic acid) and using the ozonated organic acid to remove contamination from semiconductor substrates. Any heavy metal on the wafer is said to form a formate or an acetate, and any organic contaminant is decomposed by ozone, so that stains on the surface of the substrate can be removed. [0011] T. Ohmi et al., in an article entitled “Native Oxide Growth and Organic Impurity Removal on Si Surface with Ozone-Injected Ultrapure Water” ( J. Electrochem. Soc., Vol. 140, No. 3, March 1993), describe the use of ozone-injected ultrapure water to remove adsorbed organic impurities from a wafer surface prior to other wafer cleaning procedures. Ozone concentration in the water was 1-2 ppm. The process described by Ohmi et al. was said to be capable of effectively removing organic contaminants from the wafer surface in a short time at room temperature. Processing waste from the process was said to be simple, and the chemical composition of the ozone-injected ultrapure water was said to be easily controllable. [0012] U.S. Pat. No. 5,464,480, issued Nov. 7, 1995, to Matthews et al., and entitled “Process and Apparatus for the Treatment of Semiconductor Wafers in a Fluid”, describes a process for removing organic materials from semiconductor wafers using chilled deionized water (1° C. -15° C.). The amount of ozone dissolved in the water is temperature-dependent. Lowering the temperature of the water is said to have increased the concentration of ozone in the water and to have increased the photoresist strip rate using the ozone/chilled water solution. [0013] U.S. Pat. No. 5,632,847, issued May 27, 1997, to Ohno et al., and entitled “Film Removing Method and Film Removing Agent”, describes a method of removing a film (e.g., an organic or metal-contaminated film) from a substrate surface by injecting ozone into an inorganic acid aqueous solution (e.g., a mixed solution of dilute HF and dilute HCl) and bringing bubbles formed by the ozone injection into direct contact with the film. Each bubble is said to be composed of an inside ozone bubble and an outside acid aqueous solution bubble. The Ohno et al. reference recommends an acid aqueous solution of 5 weight % or less, kept at room temperature, where the ozone concentration is within a range from 40,000 ppm to 90,000 ppm. Ozone has also been dissolved in sulfuric acid for use in cleaning semiconductor surfaces, as described, for example, in U.S. Pat. Nos. 4,917,123 and 5,082,518. [0014] U.S. Pat. No. 5,690,747, issued Nov. 25, 1997, to Doscher, and entitled “Method for Removing Photoresist with Solvent and Ultrasonic Agitation”, describes a method for removing photoresist using liquid organic solvents which include at least one polar compound having at least one strongly electronegative oxygen (such as ethylene diacetate) and at least one alicyclic carbonate (such as ethylene carbonate). [0015] European Patent Publication No. 0867924, of Stefan DeGendt et al., published Sep. 30, 1998, and entitled “Method for Removing Organic Contaminants from a Substrate”, describes the use of an agent to remove the organic contaminants, where the agent comprises water vapor, ozone, and an additive acting as a scavenger. Use of a liquid agent comprising water, ozone, and an additive acting as a scavenger is also discussed. The additive is recommended to be an OH radical scavenger, such as a carboxylic or phosphoric acid or a salt thereof. Preferred examples are acetic acid and acetate, as well as carbonate and phosphate. Although carboxylic acids as a whole are mentioned, there is no data for any carboxylic acid other than acetic acid. The authors describe how the ozone level of an aqueous ozone solution increases upon the addition of acetic acid to the water-based solution. They also disclose that photoresist strip rate increases upon the addition of acetic acid to an aqueous ozone solution. This publication is incorporated by reference in its entirety. [0016] U.S. Pat. No. 6,080,531, issued Jun. 27, 2000, to Carter et al., and entitled “Organic Removal Process” describes a method of photoresist removal in which a treating solution of ozone and bicarbonate (or other suitable radical scavenger) is used to treat a substrate for use in an electronic device. The concentration of bicarbonate ion or carbonate ion in the treating solution is said to be approximately equal to or greater than the ozone concentration. The method is said to be suited to removal of photoresist (as well as other organic materials) where metals such as aluminum, copper, and their oxides are present on the substrate surface. [0017] Japanese Patent Publication No. 2002/025971, published Jan. 25, 2002, and assigned to Seiko Epson Corp. and Sumitomo Precision Prod. Co., teaches the use of ozonated water with acetic acid and ultraviolet radiation to remove photoresist. Ozonated water containing acetic acid is continuously supplied to the center portion of a rotating substrate. The ultraviolet rays from a UV lamp are irradiated onto the substrate to remove resist adhering to the surface of the substrate. The process is said to remove organic substances such as resist adhering onto the substrate without need for high temperature heat treatment. [0018] U.S. Patent Application Publication No. 2002/0066717 A1, of Verhaverbeke et al., published Jun. 6, 2002, and entitled “Apparatus for Providing Ozonated Process Fluid and Methods for Using Same”, describes apparatus and methods for wet processing of electronic components using ozonated process fluids. Verhaverbeke et al. teach that it is desirable to have as high an ozone concentration as possible to achieve rapid cleaning of electronic components. Verhaverbeke et al. achieved ozone concentrations in water up to 300 g/m 3 by using a closed vessel with recirculated ozonated liquid, which is supplied under pressure. Verhaverbeke et al. describe the use of various chemically reactive process fluids which may be used in combination with ozone, including inorganic acids, inorganic bases, fluorinated compounds, and acetic acid. The Verhaverbeke et al. reference also provides an overview of the literature on the use of ozonated deionized water for photoresist removal from electronic component surfaces. This published patent application is incorporated by reference in its entirety. [0019] U.S. Patent Publication No. 2002/0173156 A1, of Yates et al., published Nov. 21, 2002, and entitled “Removal of Organic Material in Integrated Circuit Fabrication Using Ozonated Organic Acid Solutions”, describes the use of organic acid components to increase the solubility of ozone in aqueous solutions which are used for removing organic materials, such as polymeric resist or post-etch residues, from the surface of an integrated circuit device during fabrication. Each organic acid component is preferably said to be chosen for its metal-passivating effect. Such solutions are said to have significantly lower corrosion rates when compared to ozonated aqueous solutions using common inorganic acids for ozone solubility enhancement, due to a surface passivating effect of the organic acid component. [0020] U.S. Pat. No. 6,551,409, issued Apr. 22, 2003, to DeGendt et al., and entitled “Method of Removing Organic Contaminants from a Semiconductor Surface”, describes a method for removing organic contaminants from a semiconductor surface, where the semiconductor is held in a tank which is filled with a gas mixture comprising water vapor and ozone. DeGendt et al. teach that the use of gas phase processing, where the substrate surface is contacted with an ozone/water vapor mixture, enables an increase in ozone concentration near the wafer surface. [0021] U.S. Pat. No. 6,674,054, issued Jan. 6, 2004, to Boyers et al., and entitled “Method and Apparatus for Heating a Gas-Solvent Solution”, describes a method of quickly heating a gas-solvent solution from a relatively low temperature T 1 to a relatively high temperature T 2 , such that the dissolved gas concentration at T 2 is much higher than if the gas had originally been dissolved into the solvent at T 2 . The example of gas-solvent solution is an ozone gas in water solution. The objective is to heat a cold ozone-water solution using an in-line heater just prior to application of the solution to a substrate surface, to increase the reaction rate at the substrate surface. Table A in Col. 33 shows the solubility of ozone gas in water as a function of temperature and pressure. This '054 patent is incorporated by reference in its entirety. [0022] U.S. Pat. No. 6,696,228, issued Feb. 4, 2004, to Muraoka et al., and entitled “Method and Apparatus for Removing Organic Films”, describes a method and apparatus for removing an organic film such as a resist film from a substrate surface using a treatment liquid which can be recycled and re-used. The treatment liquid is typically formed from liquid ethylene carbonate, liquid propylene carbonate, or a mixture thereof, and typically contains dissolved ozone. Since ethylene carbonate is a solid at room temperature, this photoresist removal method requires the use of elevated temperatures, in the range of about 50-120° C. [0023] U.S. Pat. No. 6,699,330, issued Mar. 2, 2004, to Muraoka, and entitled “Method of Removing Contamination Adhered to Surfaces and Apparatus Used Therefor”, describes a method of removing surface-deposited contaminants from substrates for electronic devices. The method includes bringing an ozone-containing treating solution into contact with the surface of a treating target (such as a semiconductor substrate) on which contaminants have deposited. The ozone-containing treating solution comprises an organic solvent having a partition coefficient to ozone of 0.6 or more, where the partition coefficient refers to a partition or division of gaseous ozone between an organic solvent that is in a liquid phase at standard temperature and pressure and an inert gas in a gaseous phase which comes in contact with the organic solvent. Any organic solvents are said to be useful in the invention, so long as they provide the desired partition coefficient. Preferably organic solvents are fatty acids, including acetic acid, propionic acid, and butyric acid. Enabling embodiments are provided for acetic acid. Ozonated acetic acid is used in a closed system with a constant ozone partial pressure above the system to keep a high concentration of ozone in the acetic acid and to minimize evaporation of the acetic acid. [0024] Although high concentrations (≧200 ppm) of ozone can be obtained in acetic acid, and ozonated acetic acid may provide a rapid photoresist strip rate (≧1 μm/min), there are major drawbacks to the use of ozonated acetic acid for photoresist removal. One of the primary considerations is corrosivity. The presence of acetic acid has been observed to cause corrosion in metals, in particular, copper and molybdenum. These metals are commonly used in the flat panel display industry. Further, acetic acid is a solid at temperatures below about 16.7° C., which can cause problems under some desired processing conditions. [0025] In view of the above, there is a need for an improved method of stripping and cleaning organic materials from electronic device surfaces, particularly when metals are present. In particular, there is a need for a stripping and cleaning method which has universal applicability with respect to the surface composition of the substrate. Due to the common presence of metals in semiconductor device substrates, flat panel display substrates, and solar cell arrays, methods of stripping and cleaning organic materials which are harmful when metals are present are not attractive. [0026] Further, with respect to the manufacture of large flat panel substrates (such as those used for AMLCD or AMOLED panels, and in some instances solar panels), there is a need for a stripping and cleaning solution that can be applied over a stationary object or on an object that is moving on a conveyor belt in an atmospherically exhausted environment. [0027] In addition, it would be highly desirable if the stripping and cleaning solution could be re-used over multiple processing cycles, without the need for frequent replenishment or filtering of the solution. It would also be advantageous if such an improved method for the removal of organic materials could be performed at room temperature. SUMMARY OF THE INVENTION [0028] Described herein is method of removing an organic-containing material from an exposed surface of a large substrate (at least 0.25 m 2 ). The exposed surface of the substrate may comprise an electronic device. The exposed surface is treated with a stripping solution comprising ozone (O 3 ) in a solvent, where the solvent comprises acetic anhydride. The method has a number of advantages, including but not limited to the following: A rapid organic material removal rate of at least 0.5 μm/min, and typically greater than about 2 μm/min is typically obtained. Low corrosivity with respect to metals such as copper, molybdenum, and tungsten is observed, where the corrosion rate has been observed at about 1 nm/min. for copper, to 0.6 nm/min. for molybdenum, to 0 nm/min. for tungsten. The reagent solution (“stripping solution’) used to remove the organic-containing material is designed to avoid or minimize reactivity with metals to any extent which affects the overall electronic performance of the metal after the stripping process. The stripping process can be performed at room temperature (about 25° C.) if desired. Further, the stripping process may be performed in an atmospheric pressure exhausted system, if desired, in view of the volatility of the stripping solution. The stripping solution can be recycled over multiple processing cycles, so that it needs to be refreshed only about every 24 hours, or longer. In addition, the stripping solution is easily cleaned off the substrate surface using a water rinse. [0029] The stripping solution comprises ozone (O 3 ) in a solvent, where the solvent comprises acetic anhydride. The stripping solvent used to form the stripping solution may comprise a mixture of acetic anhydride with a co-solvent selected from the group consisting of a carbonate containing 2-4 carbon atoms, ethylene glycol diacetate, and combinations thereof. In some instances, the stripping solution may contain only acetic anhydride and ozone, where the ozone concentration is typically about 300 ppm or greater. When a co-solvent is used, the stripping solution comprises acetic anhydride, ozone, and a co-solvent which may be present at a concentration ranging from about 20% by volume to about 80% by by volume of the stripping solution. When the co-solvent is a mixture of a carbonate with ethylene glycol diacetate, the ratio of carbonate to ethylene glycol diacetate may range from about 1:1 up to about 3:1. [0030] The method of the invention may be used to strip organic materials from the surface of a substrate without concern that an exposed metal will be harmed in a manner which substantially affects the performance of a device which relies on performance of the metal. [0031] The concentration of ozone in the stripping solution typically ranges from about 50 ppm to about 600 ppm; more typically from about 100 ppm to about 500 ppm; and often from about 300 ppm to about 500 ppm. If the stripping solution contains too little ozone, the organic material removal rate will be unacceptably slow. With minimal experimentation, one skilled in the art will be able to determine an appropriate ozone concentration, based on the composition of the substrate surface. Because the solubility of ozone in an acetic anhydride-containing stripping solution increases as the concentration of acetic anhydride increases, the concentration of acetic anhydride in the stripping solution is often the maximum possible, depending on the composition of the substrate beneath the organic material which is being removed. When the stripping solution includes a co-solvent with the acetic anhydride, the co-solvent must not react with the acetic anhydride or the substrate beneath the organic material. Co-solvents which work particularly well include ethylene carbonate and ethylene glycol diacetate. [0032] When the stripping solution comprises acetic anhydride with at least one co-solvent of the kind described above, the concentration of ozone in the stripping solution typically ranges from about 50 ppm to about 300 ppm. [0033] Pure acetic anhydride exhibits a vapor pressure of about 500 Pa at 20° C. An acetic anhydride-comprising stripping solvent typically exhibits a vapor pressure within the range of about 100 Pa to about 600 Pa; more typically, from about 100 Pa to about 500 Pa. [0034] Acetic anhydride exhibits a vapor pressure which is about one third that of acetic acid at 20° C. As a result, there is a much more mild odor when acetic anhydride is used as a stripping solvent than when acetic acid is used as a stripping solvent. An anhydride-comprising stripping solvent can be used in an atmospheric pressure exhausted environment. [0035] Acetic anhydride is a liquid at standard temperature (25° C.) and pressure, since the melting point of acetic anhydride is approximately −73° C. As a result, the problems which may occur when acetic acid is used as a stripping solvent (acetic acid has a melting point of about 16.7° C. at standard pressure) do not occur when acetic anhydride is used as a stripping solvent. Since the solubility of ozone in acetic anhydride is essentially the same as the solubility in acetic acid, there are definite advantages to using acetic anhydride as the principal ingredient in a stripping solvent. Use of an acetic anhydride-comprising stripping solvent at room temperature is advantageous. When pure acetic anhydride is used as the solvent portion of the stripping solvent, the recommended temperature range for removing organic materials from the substrate ranges from about 15° C. to about 80° C. More typically, the stripping temperature will be the range of about 20° C. to about 40° C. [0036] The recommended temperature ranges are based on a combination of factors, including the time required for stripping and cleaning (removal) of the organic material and the decomposition rate of the organic material which is being stripped in the stripping solution, the volatility of the stripping solution, and the melting points of the ingredients of the stripping solution. When the stripping solvent comprises acetic anhydride in combination with about 20% by volume to about 80% by volume of one of a carbonate containing from 2 to 4 carbons (such as ethylene carbonate), ethylene glycol diacetate, or a combination thereof, a typical temperature range for removal of the organic material from the substrate is about 15° C. to about 80° C. In one typical embodiment, the stripping solvent comprises about 20% by volume acetic anhydride, about 40% by volume ethylene carbonate, and about 40% by volume ethylene glycol diacetate. One skilled in the art will be able to optimize the stripping temperature range for a specific application after minimal experimentation based on the present disclosure. [0037] Since organic compounds actually decompose (rather than just dissolve) in ozonated anhydride stripping solutions, the stripping solution can be re-used over multiple processing cycles. The number of cycles for which the stripping solution can be re-used will depend on the maximum concentration of organic material residue which is tolerable in the stripping and cleaning solution. Typically a production line for stripping organic materials from a substrate can be operated for at least one day without the need to refresh the stripping solution. [0038] The addition of a carbonate, or ethylene glycol diacetate, or a combination of these co-solvents to an acetic anhydride/ozone stripping solution both reduces the odor of the stripping solution and the minor corrosivity exhibited by the anhydride-comprising stripping solution. However, the solubility of ozone in the stripping solution is reduced by the co-solvent. BRIEF DESCRIPTION OF THE DRAWINGS [0039] The drawings which follow may be used in combination with the detailed description to aid in understanding of the invention. Identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. [0040] FIG. 1 is a graph showing the concentration of dissolved ozone (in mg/L i.e. ppm) as a function of deionized water temperature (in ° C.), when the water surface is in contact with ozone gas in oxygen at a concentration of 240 mg/L. [0041] FIG. 2A shows a schematic of one embodiment of an organic material stripping system of the kind which can be used to process large substrate in a relatively open, vented system. The stripping solution is sprayed onto a substrate surface as the substrate moves along a conveyor. [0042] FIG. 2B is a schematic showing an interior view of enclosed stripping area 204 of FIG. 2A , with a large flat panel display substrate, such as a glass-comprising substrate 210 , passing under an overhead stripping solution supply conduit 213 . The stripping solution is applied by spray 215 from spray nozzles 214 . [0043] FIG. 3 is a schematic of an exemplary stripping solution preparation system 300 , where an anhydride-comprising solvent is ozonated, to provide an ozonated anhydride-comprising stripping solution. [0044] FIG. 4A is a simplified schematic of a bubbler apparatus which can be used to generate vaporous ozonated anhydride-comprising stripping solution from a liquid ozonated anhydride-comprising stripping solution of the kind produced by the preparation system 300 shown in FIG. 3 . [0045] FIG. 4B is a schematic showing a nozzle 412 scanning over the surface 405 of a substrate 406 which is a rotating wafer. This is an embodiment method of applying a stripping solution over a substrate surface, where the anhydride-comprising stripping solution is in vapor form 407 as it exits nozzle 412 . [0046] FIG. 4C is a schematic showing a vapor distribution plate 430 used in combination with a bubbler 424 which generates a vapor form of an anhydride-comprising stripping solution. The vapor distribution plate 430 distributes the stripping vapor 432 evenly over a substrate 434 surface 433 . [0047] FIG. 5A is a schematic front-view of an alternative embodiment system 500 for applying either a liquid stripping solution or a liquid rinse for removing stripping solution residue to a substrate 504 surface 502 . The liquid is sprayed 508 upon the surface 502 as the substrate 504 moves past a spray applicator 506 . [0048] FIG. 5B is a schematic side view of the alternative embodiment system shown in FIG. 5A . The substrate 504 is positioned at an angle θ from horizontal, so that spray 508 from spray applicator 506 will be pulled toward the bottom of substrate 504 , using gravity assist to remove the liquid stripping solution or liquid rinse. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS [0049] As a preface to the detailed description presented below, it should be noted that, as used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents, unless the context clearly dictates otherwise. The term “about”, as used herein, refers to a value or range which may encompass plus or minus 10% of a particular cited value or range. [0050] FIG. 1 is a graph 100 showing the concentration on axis 102 of dissolved ozone in deionized (DI) water (in mg/L, i.e. in ppm) a function of the (DI) water temperature shown on axis 104 , when the DI water surface is in contact with ozone gas at a concentration of 240 mg/L in oxygen. It is readily apparent that the solubility of ozone in deionized water at room temperature (approximately 25° C.) is only about 40 mg/L. This requires the use of chilled (below room temperature) temperatures when a stripping solution of dissolved ozone in DI water is used, just to obtain a more helpful ozone concentration in the stripping solution. [0051] Ozone concentration in deionized water, acetic acid, and acetic anhydride solvents, where the solvent temperature is 19° C., and the solvent surface is in contact with ozone in oxygen at a concentration of about 240 mg/L at 19° C. is presented in Table One, below. TABLE ONE Ozone Concentration in Various Solvents at 19° C. Dissolved O 3 Concentration Solvent (mg/L) DI Water 55 Acetic Acid 503 Acetic Anhydride 503 [0052] As described in several of the publications referenced in the “Brief Description of the Background Art” section above, the concentration of ozone in an aqueous solution can be increased by adding acetic acid to the solution. Ozone can also be dissolved in pure acetic acid. Ozone dissolved in acetic acid or formic acid can be used to remove organic contamination and to strip photoresist from electronic device substrates. However, as previously discussed, acetic acid and formic acid are corrosive with respect to metals such as copper and molybdenum, which are used in flat panel display electronic elements. Copper and molybdenum are often present at the surface of a substrate at the time it is desired to remove an organic material from the surface of the substrate. [0053] The use of an acetic anhydride solvent rather than an acetic acid solvent makes it possible to reduce the corrosion of copper and molybdenum by a surprising amount. Table Two below shows a comparison of metal corrosion rates for copper, molybdenum and tungsten when exposed to a stripping solution of ozone in acetic acid, compared with a stripping solution of ozone in acetic anhydride. The concentration of ozone present in each solution was 300 mg/L and the exposure temperature was 20° C., with an exposure time period of one minute. TABLE TWO Metal Corrosion Rates in Ozone Solutions, in nm/min Copper Molybdenum Tungsten Corrosion Rate Corrosion Rate Corrosion Rate Stripping Solvent (nm/min.) (nm/min.) (nm/min.) Acetic Acid/Ozone 20 4 0 Acetic Anhydride/ 1 0.6 0 Ozone [0054] Clearly, there is a surprising reduction in the corrosion rate when the ozonated acetic acid stripping solvent is replaced by an ozonated acetic anhydride stripping solvent. This difference in corrosion rate enables a more complete removal of an overlying organic material while maintaining the performance capability of a metal-comprising device structure which is exposed on the surface of a substrate from which the overlying organic material is being removed. [0055] Table Three below illustrates other important physical property differences between acetic acid and acetic anhydride which show that acetic anhydride is a preferred stripping solvent when compared with acetic acid. TABLE THREE Physical Property Comparison, Acetic Acid and Acetic Anhydride Physical Property Acetic Acid Acetic Anhydride Vapor Pressure 11 3.75 (mm Hg at 20° C.) Flash Point (° C.) 40 54 Melting Point (° C.) 16.7 −73 Boiling Point (° C.) 118 139 [0056] Table Three shows a lower vapor pressure for acetic anhydride. This helps to reduce odor in the workplace attributable to presence of the stripping solvent. The higher flash point of acetic anhydride reduces the fire danger when acetic anhydride/ozone is used as the stripping solvent. The lower melting point of acetic anhydride ensures that the stripping solvent will remain a liquid under the conditions at which it is used. [0057] Ozonated acetic anhydride, at an ozone concentration of about 300 mg/L, when used as a liquid stripping agent at about 20° C., can remove 1 μm of photoresist from the surface of a semiconductor substrate (of the kind used to produce flat panel displays) in a time period of 60 seconds. Since organic compounds, including photoresists, typically decompose (rather than just dissolve) in ozonated solutions comprising acetic anhydride, a considerable amount of the decomposition products are volatilized and easily removed. As a result, the stripping solution can be recycled for re-use over multiple processing cycles. The number of cycles for which the stripping solution can be re-used will depend on the maximum concentration of organic material residue which is tolerable in the stripping and cleaning solution. Distilled water or deionized water is frequently used to wash off residual stripping solution from a substrate surface. Other solvents may be used to wash off residual stripping solution, depending on ease of handling in a particular application, and it is not intended that deionized water be the only rinse solution which may be used. [0058] However, since acetic anhydride is converted to acetic acid when exposed to water, use of a water rinse to remove residual ozonated anhydride-comprising stripping solution from the semiconductor substrate is easy. The required rinse time, using a sprayed-on rinse solution, is in the range of about 30 seconds; and, the rinse can be easily processed to remove dissolved organic materials, with the acetic acid being recovered from the rinse if desired. [0059] The corrosiveness and volatility of acetic anhydride, can be further reduced by mixing the anhydride with another organic solvent which is even less corrosive. The other non-corrosive organic solvent should be non-reactive with ozone and should exhibit a volatility which is typically less than about 30% higher than the volatility of acetic anhydride. Solvents which are non-corrosive to metals, which have little or no reactivity with ozone, which exhibit very limited reactivity with anhydrides, which are soluble in acetic anhydride, and which are liquid at room temperature when mixed with the anhydride are most desirable. Solvents which meet these criteria include (for example and not by way of limitation) ethylene carbonate, propylene carbonate, and ethylene glycol diacetate. [0060] Ethylene carbonate is a colorless, odorless solid with a flashpoint of 143.7° C. and a freezing point of 36.4° C. In its pure state, ethylene carbonate is a solid at room temperature. Ethylene carbonate is non-reactive to ozone, non-corrosive to metals, and is miscible in acetic anhydride. [0061] Like ethylene carbonate, propylene carbonate is odorless and colorless. Propylene carbonate is a liquid at room temperature. The disadvantage of propylene carbonate is that it is less soluble in water than ethylene carbonate, and thus it is more difficult to rinse residual propylene carbonate off a stripped substrate surface. [0062] Like ethylene carbonate and propylene carbonate, ethylene glycol diacetate is colorless and low in odor. Ethylene glycol diacetate is a liquid at room temperature. [0063] The solubility of ozone in ethylene carbonate or propylene carbonate is considerably less than the solubility of ozone in acetic anhydride (about 40 ppm ozone in ethylene carbonate, as opposed to roughly 500 ppm ozone in acetic anhydride, at 20° C.). Because of this decrease in ozone solubility, addition of a carbonate to the stripping solution would be used only when the substrate from which the organic material is being stripped is particularly sensitive to corrosion by the stripping solution. [0064] To provide an acceptable organic material removal rate and to maximize corrosion protection, a balance must be achieved between the concentration of the acetic anhydride and the concentration of a co-solvent used in the stripping solution. Typically, the carbonate co-solvent containing from 2 to 4 carbons is added in an amount so that the stripping solvent comprises between about 10 and about 90 volume % of this co-solvent; more typically, the carbonate comprises between about 20 and about 70 volume % of the stripping solvent; and often the carbonate comprises between about 30 and about 40 volume %, of the solvent. [0065] The present method of removing organic-containing material can be performed in a simple atmospheric pressure exhausted environment, since a solvent comprising anhydride, alone or in combination with a co-solvent of the kind described above is not particularly volatile or offensive in odor at temperatures of about 40° C. or lower. Due to their relatively low volatility of acetic anhydride and the co-solvents mentioned herein, the ozonated stripping solution can be sprayed without excessive evaporation, and in most instances can be applied at room temperature, which is typically far below the flammability point of acetic anhydride, as previously mentioned. [0066] Ideally, the ozone will decompose or oxidize the organic material completely to CO 2 or a carboxylic acid, which then is either vented through an exhaust system or is retained within the solvent. However, minimal quantities of non-oxidizable organic material components may remain after an organic material removal process. These non-oxidizable components will eventually begin to build up in the stripping solution comprising acetic anhydride and ozone. Solid contaminants which remain in the stripping solution upon recycling can be filtered out of the solution. From time to time (possibly only once a day, or even longer in most instances, depending on the solvent system), the stripping solution may need to be refreshed to flush out any residues which are accumulating. Organic residues may be removed using a “bleed-and-feed” process of the kind known in the art. [0067] Ozonated acetic anhydride-comprising stripping solution is very easily removed from the substrate by rinsing with deionized water, as previously described, because the acetic anhydride is converted to acetic acid, which is completely miscible with water. Following an organic-containing material removal process, a final treatment with deionized water or ozonated deionized water can be used to rinse off the residual stripping solution. The ozonated deionized water is used only when there is no corrosion problem on the surface of the substrate. The ozonated deionized water is helpful in removing any residual organic materials on the substrate surface which contain single carbon-to-carbon bonds. In one embodiment of the method, a substrate surface is first sprayed with a liquid ozonated acetic anhydride-comprising stripping solution, to remove organic material from the substrate surface, followed by a second spraying with a liquid ozonated deionized water to remove any remaining organics, and to rinse off the ozonated stripping solution. Optionally, a final step may be used, in which deionized water is used to remove residue from the first rinse. [0068] In another embodiment of the present method, the stripping solvent is applied to the substrate surface as a vapor (rather than as a liquid). In the case of vapor application, the use of pure acetic anhydride/ozone stripping solution (as opposed to use of a co-solvent ) simplifies recycling of the stripping solution. One skilled in the art will recognize that use of a combination of ingredients typically causes the vapor concentration to be different than the liquid concentration. Typically, the volatilizing temperature of the solvent is within a range of about 20° C. to about 150° C. The solvent vapor is brought into contact with the substrate to be stripped of organic-containing material. The solvent vapor may then be condensed on the substrate surface, leaving a layer of condensed stripping solvent on the substrate surface, followed by contacting the condensed layer with ozone gas. The ozone dissolves into the stripping solvent to form a condensed layer of ozonated acetic anhydride-comprising stripping solution that will remove the organic-containing material. [0069] In another embodiment, ozone gas may be used as a carrier gas to bring vaporized acetic anhydride-comprising solvent to the workpiece surface. In this instance, the stripping solvent is more easily a combination of ingredients, as long as these ingredients can be entrained in the ozone carrier gas, to provide an ozonated stripping solution at the substrate surface. I. APPARATUS FOR PRACTICING THE INVENTION [0070] FIG. 2A shows one apparatus embodiment which may be used for stripping of organic-comprising materials from the surface of large flat panels of the kind used for flat panel display products. The apparatus 200 makes use of a spray application of stripping solvent to the surface of the substrate from which the organic-comprising material is to be removed. The apparatus illustrated in FIG. 2A is useful for processing substrates which may be as large as several meters in width and length. The processing environment is open at the entry conveyor location 202 and is exhausted in areas where the stripping solvent is applied, such as in enclosed stripping area 204 . FIG. 2A shows a stripping apparatus 200 where a substrate (not shown) is loaded onto an open entry conveyor 202 , and enters into an enclosed stripping area 204 through an opening 206 at the leading end 208 of the enclosed stripping area. The substrate enters enclosed (and exhausted, not shown) stripping area 204 , where stripping solvent (not shown)is applied from supply 201 through conduits 203 . FIG. 2B shows a close-up schematic of the interior of enclosed stripping area 204 , in which a flat panel substrate 210 is moving across conveying rollers 212 , while stripping solution 215 is sprayed onto the surface 216 of substrate 210 through spray nozzles 214 . The spray nozzles 214 are arranged so that the entire surface 216 of the substrate 210 will be uniformly coated with the stripping solution. [0071] After application of the stripping solution 215 , the substrate passes into enclosed area 205 where a rinse (not shown) is used to wash off residual stripping solvent from the substrate. The rinse may be applied in a manner similar to that shown for the stripping solvent in FIG. 2B . After application of the rinse to the substrate surface, the substrate is passed into a drying area 207 , where the substrate is dried in a manner known in the art, such as by the application of gas flow across the substrate surface, use of heating lamps, or other commonly known techniques. After drying of the substrate, the substrate passes onto exit conveyor 209 for further handling. [0072] FIG. 3 is a schematic of an exemplary apparatus 300 for the preparation of an ozonated acetic anhydride-comprising stripping solution. The ozonated acetic anhydride-comprising stripping solution may be supplied to a spray dispenser (such as that shown in FIG. 2B ), by way of example and not by way of limitation. The ozone used for ozonation of a stripping solution which comprises acetic anhydride is typically generated in an ozone generator 304 which is supplied by an oxygen source 302 (which may provide O 2 or air). The ozone is generated by applying a silent discharge (a discharge between 2 electrodes which is not self sustaining) to the oxygen or air, to produce an ozone containing gas . The ozone-containing gas is supplied to a solution preparation tank 314 through line 310 , which feeds a sparger/mixer 316 which dispenses ozone into a liquid acetic acid-comprising solvent (not shown) which is present in solution preparation tank 314 . Also included in the ozonated acetic anhydride-comprising stripping solution preparation apparatus 300 are (for example, and not by way of limitation) an acetic anhydride supply system, which may supply acetic anhydride and other co-solvents (not shown). [0073] In one embodiment, by way of example and not by way of limitation, acetic anhydride in liquid form is fed, from line 306 and a co-solvent of the kind previously described is fed from line 308 , respectively, into a common line 312 which feeds into stripping solution supply tank 314 . When stripping solution supply tank 314 is not being filled, acetic anhydride from line 306 may be fed into common line 312 , and from there to common line 322 and into line 324 , which may be used to feed a stripping apparatus (not shown) in a process which makes use of acetic anhydride stripping solvent which is not ozonated. Common line 322 may also be used to drain residual ozonated acetic anhydride-comprising solution from solution preparation tank 314 through drain line 326 . The system may optionally include additional solvent supply apparatus (not shown) for optional co-solvents to be used in combination with an anhydride stripping solvent (such optional solvents may be a carbonate containing from 2-4 carbons, or ethylene glycol diacetate, as previously discussed, by way of example and not by way of limitation). [0074] As previously discussed, the acetic anhydride-comprising stripping solution may alternatively be applied to a substrate surface in the form of a vapor. FIG. 4A is a simplified schematic of a bubbler apparatus 400 which can be used to prepare and apply a vaporous acetic anhydride-comprising stripping solution to a substrate 406 surface 405 . For example (and not by way of limitation), a solution 403 comprising acetic anhydride (and potentially other optional solvents in admixture with the acetic anhydride) in a tank 402 is heated using heater 404 . Ozone gas is supplied to tank 402 through an ozone intake 408 . Vaporous ozonated acetic anhydride-comprising stripping solution 407 is supplied through line 410 and nozzle 412 to the surface 405 of a substrate 406 . The temperature of the vaporous ozone saturated acetic anhydride-comprising stripping solution 407 is kept higher than the temperature of the wafer 406 surface 405 . Ozone-saturated acetic anhydride-comprising stripping solution vapor 407 condenses on the cooler surface 405 of substrate 406 . To increase mass transfer of ozone at to the substrate surface 405 , fresh ozone is continuously introduced into the acetic anhydride-comprising solution 403 in tank 402 . The layer of stripping solution (not shown) on the substrate surface 405 is very thin, so that ozone diffuses through the layer rapidly. [0075] FIG. 4B is an illustration of the application of the vaporous stripping solution 407 , where an application nozzle 412 (for example and not by way of limitation, as several nozzles may be used) is scanned over the surface 405 of substrate 406 . The substrate is typically rotated as shown by arrow 414 in FIG. 4A , to aid in distributing the constant feed of condensing ozonated anhydride-comprising stripping solvent (not shown) over substrate surface 405 . [0076] FIG. 4C shows a simplified schematic of another vaporous stripping solvent application apparatus 420 , where ozone is fed through ozone intake line 422 into a bubbler tank 424 containing at least one anhydride solvent (and potentially other co-solvents) 423 . The ozonated solvent present in bubbler tank 424 is heated using heater 426 to produce a vapor which is fed through a line 428 into a distribution plate 430 , from which stripping vapor 432 is dispensed onto a flat panel substrate 434 which is moving under distribution plate 430 in the manner shown, on a conveyor (not shown). The vapor condenses on substrate 434 surface 433 to produce a condensed stripping solvent 435 on the surface 433 of substrate 434 . One skilled in the art will recognize that the substrate 430 could be stationary, with the distribution plate 430 moving past the substrate 430 . II. EXAMPLES Example One Removal of Photoresist from a Substrate Surface Using [0077] Ozonated Acetic Anhydride [0078] A layer of a deep ultra-violet (DUV) photoresist which is sensitive to 248 nm radiation (UV 6, available from Shipley, Marlborough, Mass.) was applied to a thickness of approximately 10,000 Å (1,000 nm) onto the surface of a single-crystal silicon wafer. The photoresist was applied using a spin-on process, then baked for 30 minutes at 95° C. Ozonated acetic anhydride (100% acetic anhydride) stripping solution containing about 300 ppm (mg/L) of ozone was sprayed onto the surface of the photoresist-coated substrate at room temperature (25° C.) using a dispensing system such as that shown in FIG. 2B . The ozonated acetic anhydride was allowed to react with the photoresist for a period of 30, 60, or 120 seconds, then rinsed off the substrate surface by spraying with deionized water for a period of 10 to 20 seconds. [0079] A series of six substrate samples were tested, where 1 μm of photoresist was present on each substrate, and the exposure time to stripping solution was varied from 30 seconds to about 120 seconds. Subsequent to the photoresist stripping procedure, each sample was examined and measured for residual photoresist. It was discovered that the 1 μm of photoresist was removed after 30 seconds (or less) from all of the substrates. Example Two Corrosivity of Ozonated Acetic Anhydride on Aluminum [0080] A layer of aluminum was deposited to a thickness of about 10,000 Å onto the surface of a single-crystal silicon wafer using a physical vapor deposition (PVD) process of the kind known in the art. To test the corrosivity of ozonated acetic anhydride stripping solution on aluminum, ozonated acetic anhydride (100% acetic anhydride) stripping solution containing about 300 ppm (or mg/L) of ozone was sprayed onto the surface of the aluminum-coated substrate at room temperature (25° C.) using a dispensing system such as that shown in FIG. 2B . The ozonated acetic anhydride stripping solution was allowed to react with the aluminum for a period of 30, 60, or 120 seconds, then rinsed off the substrate surface by spraying with deionized water for a period of 10 to 20 seconds. [0081] Within the accuracy of our ability to measure, aluminum was not removed by the ozonated acetic anhydride stripping solution. There appears to be a slight increase in the thickness of the aluminum layer, but the amount of increase in inconsistent with time. The increase in thickness of the aluminum layer may be due to the formation of Al 2 O 3 on the surface of the aluminum layer due to exposure to O 3 . However, the amount of change in aluminum thickness due to exposure to the stripping solution is so minor, less than 0.3 percent, that it may be within experimental error of the method of measurement. This indicates virtually no corrosion of the aluminum over a 120 second exposure time to the stripping solution. In the event it is determined that any significant amount of aluminum oxide is formed, one skilled in the art may use techniques known in the art to treat the surface of the substrate to remove oxide to the extent necessary to permit device function in the end use application. Example Three Corrosivity of Ozonated Acetic Anhydride a Copper Surface [0082] A layer of copper was deposited to a thickness of 8,000 Å (800 nm) to 19,000 Å (1,900 nm) onto the surface of a single-crystal silicon wafer. The copper was deposited using a physical vapor deposition (PVD) process, followed by electrochemical plating. In order to test the corrosivity of ozonated acetic anhydride stripping solution on copper, ozonated acetic anhydride (100% acetic anhydride) containing at least 300 ppm (or mg/L) of ozone was sprayed onto the surface of the copper-coated substrate at room temperature (25° C.) using a dispensing system such as that shown in FIG. 2B . The ozonated acetic anhydride stripping solution was allowed to react with the copper surface for a period of 30, 60, or 120 seconds, then rinsed off the substrate surface by spraying with deionized water for a period of 10 to 20 seconds. [0083] Table Four, below, shows the thickness of the titanium nitride layer before and after treatment with an ozonated acetic anhydride stripping solution containing 300 ppm (or mg/L) of ozone at room temperature (25° C.). TABLE FOUR Corrosivity of Ozonated Propionic Acid Cleaning Solution on Copper Change in Pre-Treatment Post-Treatment Cu Layer Treatment Cu Thickness Cu Thickness Thickness Sample # Time (sec) (Å) (Å) (Å) 12 30 18,266 18,293 +26 13 60 8,636 8,619 −17 14 120 9,777 9,726 −51 [0084] Within the accuracy of our ability to measure, the data in Table Four indicate that the thickness of the copper layer decreased only slightly upon exposure to ozonated acetic anhydride stripping solution. [0085] While the invention has been described in detail above with reference to several embodiments, various modifications within the scope and spirit of the invention will be apparent to those of working skill in this technological field. Accordingly, the scope of the invention should be measured by the appended claims.

Described herein is a method of removing an organic-containing material from an exposed surface of a large substrate (at least 0.25 m 2 ). The substrate may comprise an electronic device. The exposed surface is treated with a stripping solution comprising ozone (O 3 ) in a solvent, where the solvent comprises acetic anhydride. The stripping solvent used to form the stripping solution may comprise a mixture of acetic anhydride with a co-solvent selected from the group consisting of a carbonate containing 2-4 carbon atoms, ethylene glycol diacetate, and combinations thereof. In some instances, the stripping solution may contain only acetic anhydride and ozone, where the ozone concentration is typically about 300 ppm or greater.

[0001] The present invention relates to a process for growing bulk monocrystalline gallium nitride (GaN) from solution. In particular, the invention relates to the method for growing GaN single crystals by recrystallizing GaN from a solution with (applying) temperature gradient at moderate pressures and temperatures. [0002] Nitrides of In, Ga, and Al and their compounds are used in both high power and light emitting devices. However, the efficiency of these devices is hampered by vertical shorts stemming from defects which propagate from the substrate into device active layers and often originate from heteroepitaxial growth. The need and importance (benefit) of using low defect GaN monocrystalline material as a native substrate for further progress in III-N device applications is described elsewhere. [0003] One of the techniques presently used for production of gallium nitride substrates is hydride vapor-phase epitaxy, which has been used to grow GaN wafers up to about 2 inches in diameter. The dislocation density of the best of such samples is approximately 10 5 /cm 2 . [0004] Another known technique for single-crystal growth involves deposition of gallium nitride from a liquid phase. Growth from the liquid phase has resulted in gallium nitride single crystals with dislocation densities of less than 10 2 /cm 2 . Some of the liquid phase techniques are done using high pressures and high temperatures. High nitrogen pressure counters the gallium nitride decomposition that occurs above 1500° C. required to dissolve nitrogen in gallium. These high-pressure/high-temperature techniques have been used to grow gallium nitride crystal platelets of up to 1.5 cm in lateral size. Since crystal growth requires pressures on the order of 10 kbar or more and the rates of crystal growth are low, the routine growth of 2 inch-diameter wafers on a production scale is a daunting challenge for the high temperature high pressure techniques. [0005] Gallium nitride has also been grown at lower temperatures/pressures by a sodium flux method. This flux method uses elemental gallium, gaseous nitrogen and either elemental sodium metal or sodium with additives of alkali or alkaline earth metals to increase reactivity and solubility of nitrogen in gallium. In the sodium flux method, the gaseous nitrogen reacts with the flux/elemental gallium to saturate the solution and deposit crystals. For these flux techniques, it has been difficult to establish and control growth of large gallium nitride crystals because the composition of the melt is not well controlled. [0006] Small gallium nitride crystals have been grown in supercritical ammonia NH 3 in pressure vessels. These supercritical ammonia growth processes exhibit slow growth rates, and thus do not enable commercial production of large gallium nitride crystals. Also, the pressure vessels limit these gallium nitride growth processes and it is difficult to maintain the purity of the grown crystals. [0007] The known gallium nitride crystal production processes are not believed to provide an economical process that enable moderate-cost low defect density and high purity gallium nitride crystal production. [0008] Therefore, a gallium nitride crystal growth process that produces large gallium nitride crystals of high quality is needed. Further, a gallium nitride crystal growth process that can produce moderate cost large gallium nitride crystals of high quality is needed. [0009] This invention provides improved control over Group III nitrides, particularly gallium nitride, single crystal growth. [0010] This invention can be used to prepare single crystal gallium nitride (GaN) at moderate temperature and near atmospheric pressure. [0011] This invention can be used to use GaN as a feedstock (source) to grow single crystal GaN on a seed at near atmospheric pressure in a process characterized by a temperature gradient or a temperature difference. [0012] This invention can grow a GaN single crystal using GaN as a source, prepared in situ during the same growth run—self-developing process. [0013] This invention can use a source prepared in situ during the same growth run and using a solvent prepared in situ during the same growth run to dissolve GaN feedstock and to grow single crystal GaN—self-developing process. [0014] This invention can be used to grow single crystal gallium nitride of a large size exceeding about one inch. [0015] This invention can be used to grow commercial size and commercial grade single crystal gallium nitride for use in electronic devices. [0016] This invention can grow single crystal gallium nitride by a moderate temperature and moderate pressure process with a dislocation density in the crystals of fewer than about 10 4 dislocations per square centimeter. [0017] These and other aspects of this invention can be accomplished by a process of growing single crystal gallium nitride at nitrogen pressure and temperature in the region of the phase diagram where gallium nitride is thermodynamically stable. This process includes using solid gallium nitride as a feedstock for growing single crystal gallium nitride from the solution by applying a temperature gradient. This gallium nitride feedstock is synthesized in situ during the same growth run (self-developing process, in situ source formation). Synthesized gallium nitride feedstock dissolves in the solvent, which is also produced in situ during the same growth run (self-developing process, in situ solvent formation), and then precipitates from the solution as a GaN crystal. By using solid GaN as a feedstock we eliminate the dissolution of gaseous nitrogen in a liquid, and thereby eliminate a change in the solution's composition during the growth of single crystal gallium nitride. In situ synthesized gallium nitride is porous with high surface area and simultaneously is high purity material. These combined properties of the in situ synthesized gallium nitride source are very beneficial for growth. High surface area of the in situ prepared gallium nitride promotes dissolution of the feedstock, and creates better growth conditions in terms of ease of feeding the solution with source gallium nitride or III-Nitride. Porous material with high surface area which is exposed to atmosphere is contaminated with oxygen and moisture which may be incorporated into the growing crystal. In situ prepared gallium nitride source is not exposed to atmosphere and is not contaminated with oxygen and moisture from the atmosphere. By using the disclosed proper solvent, prepared in situ during the same growth run, gallium nitride source can be dissolved at moderate pressure and moderate temperature and then the gallium nitride crystal grows from the self developed (created) solution at moderate pressure and near atmospheric temperature. [0018] In practice this invention includes the steps of selecting components for a reactor to provide a predetermined temperature gradient under operating conditions and assembling these components and enclosing a reaction vessel and charge therein. This charge includes (1) a Group IA or/and Group IIA element nitride (an alkali metal or/and alkaline earth metal nitride) layer located in a region of the reaction vessel, which under growth conditions will have a temperature at or near the high end of the temperature gradient, and (2) a layer of gallium or composition of gallium with an alkali metal or/and alkaline earth metal interposed between the Group IA or/and Group IIA nitride and the deposition site, and (3) also may include at least one seed crystal located in the deposition site (a region of the reaction vessel, which under growth conditions will have a temperature at or near the low end of the aforementioned temperature gradient); simultaneously subjecting the reaction vessel and the charge therein both to pressure and temperature in the gallium nitride-stable region of the phase diagram of gallium nitride and first to heat to a temperature of the reaction point between a Group IA or/and Group IIA nitride and gallium, whereby Group IA or/and Group IIA nitride and gallium are first reacted to substitute Group IA or/and Group IIA metal in nitride with gallium and formed gallium nitride feedstock (source), and at the same time the released Group IA or/and Group IIA element is mixed with residual gallium and forms a solvent for gallium nitride, then at the predetermined growth temperature and pressure the aforementioned formed gallium nitride feedstock is dissolved in the formed molten solvent within the hotter part of the reaction vessel, and precipitates from the solution to grow a single crystal either self seeded or on a seed if one (or more) was included in a cooler part of the reaction vessel. BRIEF DESCRIPTION OF THE DRAWINGS [0019] FIG. 1 is a schematic cross sectional view showing an example of GaN growth reactor: (a) before the reaction, (b) after the reaction and growth. [0020] FIG. 2 is a schematic cross sectional view showing an example of GaN growth reactor with seed located at the bottom of the reaction vessel (a) before the reaction, (b) after the reaction and growth. [0021] FIG. 3 is a schematic cross sectional view of the growth reactor with the substrate at the bottom of the reaction vessel (a) before the reaction, (b) after the reaction and growth. [0022] FIG. 4 is an optical image of (a) the seed—HVPE GaN polycrystalline aggregate before growth run, (b) the seed—HVPE GaN polycrystalline aggregate after growth run with grown GaN crystals, (c) and (d) zoomed images of the crystals shown on the FIG. 2 c, arrow indicates m direction, (e) grown crystals are separated from the seed. [0023] FIG. 5 is room temperature micro-Raman spectrum of the GaN crystal grown on the polycrystalline GaN seed in the backscatter geometry. [0024] FIG. 6 is XRD rocking curve of the (0004) reflection for the GaN crystal grown on the polycrystalline GaN seed. [0025] FIG. 7 is (a) low temperature PL spectra of crystals grown on polycrystalline aggregate seed, (b) reduction of yellow band in the grown crystals compared to the seed. [0026] FIG. 8 is (a) image of the HVPE GaN template used as a seed with epitaxially grown GaN layer, (b) omega-2theta space map of the symmetric (0004) reflection for the (a) as-received GaN seed and (b) Ga-face of the GaN grown crystal. DETAILED DESCRIPTION [0027] This disclosure pertains to a process for growing single crystal gallium nitride which process is characterized by the use of a solvent that dissolves gallium nitride feedstock or source of gallium nitride and the application of a temperature gradient to control dissolution of solid gallium nitride in the solvent and precipitation of gallium nitride from the solution on a seed or on another nucleation site to grow gallium nitride single crystal. [0028] One essential part of the invention is the formation of the gallium nitride feedstock during the first stage of the growth run (self-developing process). The gallium nitride feedstock is formed by the exchange reaction of Group IA or/and Group IIA element (alkali metal or/and alkaline earth metal) nitride with gallium. [0029] Another essential part of the invention is a solvent formation during the exchange reaction between Group IA or/and Group IIA element nitride and gallium (self-developing process). As a result of this reaction Group IA or/and Group IIA element is released and creates a compound with an initial composition. The new composition serves as a solvent for the GaN source. [0030] More specifically, the process for growing single crystal gallium nitride includes the following steps. Group IA or/and Group IIA element nitride is placed in a region of the reaction vessel, which under operating conditions will have a temperature at or near the high end of the temperature gradient, and a layer of material comprised of gallium or gallium with alkali metal or/and alkaline earth metal composition interposed between the Group IA or/and Group IIA nitride and the deposition site (a region of the reaction vessel, which under operating conditions will have a temperature at or near the low end of the aforementioned temperature gradient), and also may include at least one seed crystal located within the deposition site. The reaction vessel with the charge is placed in the reactor filled with nitrogen, simultaneously subjecting the reaction vessel and the charge therein both to pressure and temperature in the gallium nitride-stable region of the phase diagram of gallium nitride. Pressure of nitrogen during the growth run is maintained in the range from 0.1 MPa to 20 MPa, but not limited to within this range. The charge is heated under nitrogen atmosphere to the temperature when the reaction between Group IA or/and Group IIA element nitride and gallium occurs. As a result of this exchange reaction part of the gallium replaces Group I and/or Group II element in the nitride and gallium nitride feedstock is created. Released from the nitride Group IA or/and Group IIA element is mixed with residual gallium or its said composition and forms a compound which serves as a solvent for gallium nitride source. The next step of the process is to maintain the growth temperature and pressure with a temperature gradient between the formed GaN feedstock and the nucleation site. The formed gallium nitride feedstock is dissolved by the solvent in a region of the reaction vessel, which under operating conditions has a temperature at or near the high end of the temperature gradient and said dissolved gallium nitride precipitates as a single gallium nitride crystal within the deposition site, which under operating conditions has a temperature at or near the low end of the aforementioned temperature gradient. The deposition site may have at least one GaN seed or the gallium nitride crystal can start to grow by spontaneous nucleation. The heat is kept for the time required to grow the desired gallium nitride crystal and then the heating step is discontinued. [0031] The process involves the use of a Group IA (alkali metal) nitride or/and a Group IIA (alkaline earth metal) nitride. Of the alkali nitrides, lithium nitride is preferred. [0032] The temperature gradient inside the molten solvent between the gallium nitride source (hotter region of reaction vessel) and the growing single crystal gallium nitride (cooler region of reaction vessel) promotes dissolution of the gallium nitride source, creating a supersaturated solution of gallium nitride in the solvent, and precipitation of the gallium nitride either on the coldest parts of the reaction vessel, containing the solution and the source of gallium nitride or on one or more seed crystals located in a deposition zone. [0033] Disclosure of the process here is made in connection with the equipment, shown in FIG. 1 a, b, where reactor 11 with nitrogen inlet 12 is shown containing furnace 13 with reaction vessel 14 disposed therein containing solid Group IA or/and Group IIA element nitride 15 at the bottom thereof and gallium or gallium with alkali metal or/and alkaline earth metal composition 16 disposed thereover. Optional holder 17 holding optional seed gallium nitride crystal 18 may be immersed in or in contact with the solvent 21 . Operation of the equipment shown in FIG. 1 typically involves disposition of Group IA or/and Group IIA element nitride 15 and gallium or gallium with alkali metal or/and alkaline earth metal composition 16 in the reaction vessel 14 , heating the charge to the temperature of the reaction between Group IA or/and Group IIA element nitride and gallium, creating gallium nitride source 20 and solvent 21 by exchange reaction of Group IA or/and Group IIA element nitride 15 with gallium 16 , maintaining growth temperature and providing a temperature gradient whereby temperature of the solvent 21 (formed during the exchange reaction) nearby the gallium nitride source is higher than temperature of the molten solvent nearby the place where gallium nitride single crystal 19 is growing, all under pressure of a gas, containing nitrogen, in the reactor 11 , precipitating single crystal gallium nitride 19 and cooling the charge. [0034] In another embodiment of this invention, shown in FIG. 2 , a seed of gallium nitride 18 is placed at the bottom of the reaction vessel 14 , covered with gallium or gallium with alkali metal or/and alkaline earth metal composition 16 and solid Group IA or/and Group IIA element nitride 15 disposed thereover. In this case, the gallium nitride source 21 is formed during the exchange reaction at the top of the charge located within the reaction vessel and solvent 20 is formed under the source, providing the temperature gradient has opposite direction compared to the previous embodiment, shown in FIG. 1 . [0035] Instead of using a small gallium nitride seed, a gallium nitride template can be used as a substrate for growing a thick gallium nitride layer, as shown in FIG. 3 . [0036] During the process of gallium nitride growth, the formed solvent is in a molten state at a temperature in the range of 700-900° C., more typically 750-850° C. and the nitrogen pressure in the growth reactor is typically above atmospheric, more typically 0.1-1.0 MPa. The temperature gradient, i.e., the temperature difference inside the solvent between the gallium nitride source and the growing crystal, is typically 1-100° C. across the thickness of the solvent, and more typically 5-50° C. [0037] In an embodiment of this process with a seed crystal, the seed crystal is typically the coldest spot in the reaction vessel within the reactor when precipitation of single crystal gallium nitride takes place. Due to the driving force imparted to the gallium nitride dissolved in the solvent, gallium nitride leaves the solvent when the solvent becomes supersaturated with gallium nitride and precipitates on the seed crystal, thereby growth of gallium nitride propagates on the seed crystal. If the process is carried out without the seed crystal, nucleation and growth of gallium nitride takes place within the colder parts of the reaction vessel containing the solvent. The resulting crystals typically have single crystal structure. [0038] Having described the invention, the following examples are given as a particular embodiment thereof and to demonstrate the practice and advantages thereof. It is understood that the example is given by way of illustration and is not intended to limit the specification of the claims in any manner. EXAMPLE 1 [0039] This example demonstrates preparation of single crystal gallium nitride at moderate temperature and moderate pressure using lithium nitride and gallium in the set-up shown in FIG. 1 where the reaction vessel (crucible) 14 contained a lithium nitride pill 15 with the gallium 16 disposed thereover. All material preparations of the charge were carried out inside a glove box under a nitrogen atmosphere with moisture and oxygen content below 1 ppm. [0040] In carrying out the process, a layer of commercially available lithium nitride, which was preliminarily compacted into a pill of approximately 1.2 g, was placed at the bottom of the reaction vessel. On top of the lithium nitride pill 15.0 g of gallium was placed. After the crucible was filled with the charge, it was placed into the reactor 11 . The reactor was evacuated to a vacuum level of 10 −3 Torr, filled with nitrogen of 99.999% purity to a pressure of 0.1 MPa and then evacuated to a vacuum level of 10 −3 Torr once more. After the evacuation, the furnace was filled with nitrogen of 99.999% purity to a pressure of 0.24 MPa. Then the crucible was heated by the furnace 13 . During heating, part of the gallium reacted with lithium nitride, and gallium nitride source was formed at the bottom of the crucible as a result of this exchange reaction. At the same time, the lithium released during the exchange reaction, mixed with residual liquid gallium and formed a solvent for gallium nitride. After the completion of the reaction the temperature of the lower end of the reaction vessel was maintained at 800° C. and the temperature at the higher end of the solvent was maintained at 790° C., resulting in a temperature difference of 10° C. inside the solvent in the reaction vessel. Gallium nitride source started to dissolve in the created solvent, saturating the solution. To create a precipitation site, a piece of polycrystalline gallium nitride seed ( FIG. 4 ) was immersed from the top into the solution when the temperature at the bottom reached 800° C. The growth conditions of the process were maintained for 65 hours following which, the polycrystalline seed was pulled out, the reactor was cooled to room temperature and the nitrogen pressure was allowed to be reduced to atmospheric. [0041] After cleaning the remaining solution from the seed, grown crystals of different orientations were found on the immersed portion of the seed. Most of the crystals formed as an epitaxial expansion of the crystallites of the aggregate ( FIG. 4 b,d ). Some crystals were nucleated as twins on the very edge of the crystallites and developed as freestanding crystals ( FIG. 4 b,c ). Most of the crystals grew epitaxially with the highest growth rates in the m-direction ( FIG. 4 d ). All of the grown crystals were transparent and colorless, with well-defined hexagonal morphology. Micro-Raman measurements were performed at room temperature in the backscattering geometry, in order to characterize the structural quality of the sample. Examination of the grown crystals with μRS spectroscopy in the geometry showed the first-order allowed E 2 1 , E 2 2 and A 1 (LO) phonons with full width at half-maximum (FWHM) of 0.26, 3.1 cm −1 and 6.9 cm −1 , respectively ( FIG. 5 ). The sharp linewidths indicate high structural quality and low impurity concentrations [ 13 ]. [0042] High crystallinity of the grown crystals was also confirmed by X-ray diffraction (XRD). FWHM of about 16 arc-sec was obtained for the (0004) rocking curve, excluding the additional dispersion and convolution corrections that would only enhance this number slightly ( FIG. 6 ). [0043] Low temperature PL (LT-PL) measurements were performed to evaluate the optical and electronic quality of the grown crystals. The position and intensity of the PL spectral peaks provide information about the type and concentration of the impurities, respectively. A dominant peak at 3.47 eV was observed in the spectra of crystals grown on polycrystalline aggregate seed (shown in FIG. 7 a ) and has been attributed to excitons bound to neutral shallow donor impurities (XD 0 or D 0 X). High crystalline quality of the grown crystals was verified by improved XD 0 line shape and linewidth, as compared with that of the seed. Reduction of the yellow band (YB) intensity, shown in FIG. 7 b, is consistent with lower native defects and/or residual impurity concentration in the growth crystal, as compared with that of the seed. EXAMPLE 2 [0044] A layer of commercially available lithium nitride, which was preliminarily compacted into a pill of approximately 1.2 g was placed at the bottom of the reaction vessel. On top of the lithium nitride pill 14.0 g of gallium was placed. After the reaction vessel was filled with the charge, it was placed into the reactor 11 . The reactor was evacuated to a vacuum level of 10 −3 Torr, filled with nitrogen of 99.999% purity to a pressure of 0.1 MPa and then evacuated to a vacuum level of 10 −3 Torr once more. After the evacuation, the furnace was filled with nitrogen of 99.999% purity to a pressure of 0.25 MPa. Then the crucible was heated by the furnace 13 . During heating, part of the gallium reacted with lithium nitride, and gallium nitride source was formed as a result of this exchange reaction. At the same time, the lithium released during the exchange reaction mixed with residual liquid gallium and formed a solvent for gallium nitride. After the exchange reaction, the temperature of the lower end of the reaction vessel was maintained at 800° C. and the temperature at the higher end of the solvent was maintained at 790° C., thereby resulting in a temperature difference of 10° C. inside the solvent in the reaction vessel. Gallium nitride source started to dissolve in the created solvent, saturating the solution. A seed of quasi single crystal HVPE gallium nitride was partly immersed from the top into the solution when the temperature at the bottom reached 800° C. The growth conditions of the process were maintained for 126 hours following which, the seed was pulled out, the system was cooled to room temperature and the nitrogen pressure was allowed to be reduced to atmospheric. A homoepitaxial layer of gallium nitride single crystal was grown on the immersed part of the seed. The image of the gallium nitride seed with epitaxially grown gallium nitride layer is shown in FIG. 8 a. [0045] The nearly 100-μm thick homoepitaxially grown layer showed a two order-of-magnitude reduction in the full-width-at-half-maximum (FWHM) of the (0004) XRD diffraction peak. FWHM of the X-ray rocking curve measured on both the Ga- and N-face of the sample are 111 and 127 arcsec, respectively, compared to 2.15 degree and 2.45 degree for the Ga- and N-face of the GaN seed, respectively. It is unprecedented result of the improvement of the crystalline quality in the epitaxially grown GaN layer. FIG. 8 b,c displays an omega-2theta space map of the symmetric (0004) reflection for the Ga-face ( 8 b ) as-received GaN seed and ( 8 c ) GaN grown crystal. [0046] While presently preferred embodiments have been shown of the novel process, and of the several modifications discussed for the purpose of illustration, the foregoing description should not be deemed to be a limitation of the scope of the invention. Accordingly, persons skilled in this art will readily appreciate that various additional changes and modifications may be made without departing from the spirit of the invention as defined and differentiated by the following claims.

A process for making gallium nitride crystals comprising the steps of charging a reaction vessel with a layer of one selected from a Group IA element nitride, a Group IIA element nitride, and combinations thereof, adding a layer of gallium, applying nitrogen pressure to prevent dissociation or decomposition, forming in situ a gallium nitride source by heating the charged reaction vessel to render the one selected from the group reacted with the gallium, forming in situ a solvent comprising the gallium and the one selected from the group released by an exchange reaction between the gallium and the one selected from the group, providing a temperature when formed gallium nitride will be dissolved in the formed solvent and providing a temperature difference in the solvent between the formed gallium nitride source and the growing single crystal gallium nitride, and growing a single crystal gallium nitride.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a semiconductor memory device, and more specifically, it relates to a semiconductor memory device having a structure capable of supplying a stable power supply voltage. [0003] 2. Description of the Prior Art [0004] The structure of a conventional semiconductor memory device 9000 is described with reference to FIG. 20. The semiconductor memory device 9000 shown in FIG. 20 has an internal circuit group 990 including memory cells and a synchronous circuit 995 generating an internal clock. The synchronous circuit 995 is driven by an operation start trigger signal and generates the internal clock deciding operation timing in the internal circuit group 990 . The synchronous circuit 995 is formed by a PLL circuit or the like, for example. [0005] As shown in FIG. 20, the synchronous circuit 995 and the internal circuit group 990 share a power source 900 , to operate with a power supply voltage received from the power source 900 and a ground voltage GND as operating voltages. [0006] The operating voltages must be stable so that the synchronous circuit 995 performs a synchronous operation in high precision. [0007] When the internal circuit group 990 operates, however, noise originates following current consumption to disadvantageously swing the power supply voltage. In the structure of the conventional semiconductor memory device 9000 , therefore, precision of the internal clock is disadvantageously damaged following the internal operation. [0008] When the internal circuit group 990 is defective, the power supply voltage or a signal voltage similarly swings. Therefore, influence following a failure of the internal circuit group 990 must be suppressed not only for circuits in the same chip but also for another device connected through the same wire. SUMMARY OF THE INVENTION [0009] Accordingly, an object of the present invention is to provide a semiconductor memory device having a large operation margin in a high-frequency operation by supplying a stable power supply voltage. [0010] Another object of the present invention is to provide a semiconductor memory device capable of guaranteeing a stable operation of an apparatus connected through the same wire while suppressing influence exerted by a failure. [0011] A semiconductor memory device according to an aspect of the present invention comprises an internal circuit including a memory cell array, a voltage supply node, a synchronous circuit operating on the basis of an operating voltage received from the voltage supply node for generating an internal clock deciding operation timing of the internal circuit, a power source for supplying a voltage to the internal circuit and the voltage supply node, and a voltage stabilizing circuit stabilizing the voltage of the voltage supply node. [0012] Preferably, the voltage stabilizing circuit includes a detection circuit detecting change of the voltage of the voltage supply node and a circuit supplying the voltage from the power source to the voltage supply node in response to an output of the detection circuit. [0013] According to the aforementioned semiconductor memory device, therefore, a precise synchronous operation is guaranteed by arranging a circuit eliminating power supply noise and supplying a stable operating voltage to the synchronous circuit also when the synchronous circuit and the internal circuit use the same power source. [0014] Preferably, the power source includes a first power source corresponding to a first voltage and a second power source supplying a second voltage lower than the first voltage, the voltage supply node includes a first voltage supply node corresponding to the first power source and a second voltage supply node corresponding to the second power source, the voltage stabilizing circuit is provided between the first power source and the first voltage supply node, and the semiconductor memory device further comprises a dummy current generation circuit feeding a dummy current from the first voltage supply node to the second voltage supply node at prescribed timing. More preferably, the dummy current generation circuit includes a transistor provided between the first voltage supply node and the second voltage supply node and rendered conductive at prescribed timing. [0015] The dummy current is fed between the power source supplying an internal voltage to the synchronous circuit and a GND side. Thus, the operation of the detection circuit (differential amplifier) arranged on the side of the power source for detecting change of the operating voltage is stabilized. [0016] Preferably, the power source includes a first power source corresponding to a first voltage and a second power source supplying a second voltage lower than the first voltage, the voltage supply node includes a first voltage supply node corresponding to the first power source and a second voltage supply node corresponding to the second power source, the voltage stabilizing circuit is provided between the first power source and the first voltage supply node, and the semiconductor memory device further comprises a high impedance element raising the impedance between the second voltage supply node and the second power source. [0017] A high impedance component is arranged on the GND side, thereby preventing a ground voltage from mixture with noise. [0018] Preferably, the semiconductor memory device further comprises a voltage change circuit provided between the first voltage supply node and the second voltage supply node for changing the voltages of the first and second voltage supply nodes in the same direction. More preferably, the voltage change circuit includes a capacitive element provided between the first voltage supply node and the second voltage supply node. [0019] The operating voltage of the synchronous circuit can be kept constant by changing the power source side and the GND side in the same direction. [0020] More preferably, the semiconductor memory device further comprises a filter provided between the power source and the voltage stabilizing circuit. [0021] A more stable operating voltage can be supplied to the synchronous circuit by serially connecting the filters between the power source and the synchronous circuit. [0022] A semiconductor memory device according to another aspect of the present invention comprises a pin, an internal circuit, including a memory cell array, operating on the basis of an input from the pin, and a leakage current prevention circuit provided between the pin and the internal circuit for detecting a leakage current from the internal circuit and electrically disconnecting the pin and the internal circuit from each other. [0023] Preferably, the leakage current prevention circuit includes a detection circuit detecting change of an operating voltage of the internal circuit following the leakage current, and a circuit electrically disconnecting the pin and the internal circuit from each other in response to an output of the detection circuit. [0024] Therefore, the aforementioned semiconductor memory device detects an abnormal current (leakage current) generated in the internal circuit and disconnects the pin and the internal circuit from each other. Thus, influence exerted on an external device by the leakage current can be suppressed. [0025] More preferably, the circuit includes a voltage supply circuit supplying an operating voltage to the internal circuit on the basis of a voltage supplied from the pin, and the voltage supply circuit stops supply of the operating voltage to the internal circuit in response to the output of the detection circuit. [0026] Operations of another chip using the same power supply line can be guaranteed by stopping supply of the operating voltage on the basis of a result of detection of the leakage current. [0027] A semiconductor memory device according to still another aspect of the present invention comprises a pin receiving an input from an external device, an internal circuit, including a memory cell array, operating in response to an input from the pin in a normal mode, a voltage supply node, a synchronous circuit operating on the basis of an operating voltage received from the voltage supply node for generating an internal clock deciding operation timing of the internal circuit, and a voltage supply control circuit supplying a voltage from the pin to the voltage supply node in a test mode. [0028] Thus, the aforementioned semiconductor memory device employs the pin used in the normal mode as a power supply pin for the synchronous circuit in the test mode. When a plurality of chips receive the same signal or voltage through the same signal line or power supply line and a leakage current is generated in any of the chips, for example, reduction of the voltage level of the signal line or the power supply line can be prevented by stopping activation of circuits included in the defective chip. [0029] Preferably, the pin includes a first pin corresponding to a first voltage and a second pin supplying a second voltage lower than the first voltage, the voltage supply node includes a first voltage supply node corresponding to the first pin and a second voltage supply node corresponding to the second pin, and the voltage supply control circuit includes a first voltage supply control circuit supplying the voltage from the pin to the first voltage supply node in the test mode and a second voltage supply control circuit supplying the voltage from the pin to the second voltage supply node in the test mode. More preferably, the first voltage supply control circuit operates to stabilize the voltage of the first voltage supply node, and the second voltage supply control circuit operates to stabilize the voltage of the second voltage supply node. [0030] The operating voltage can be stably supplied to the synchronous circuit in the test mode by providing control circuits for supplying the voltage on a power supply side and a GND side respectively. [0031] Preferably, the voltage supply control circuit includes a generation circuit generating a prescribed signal in the test mode, and a switching circuit supplying the input from the pin to the synchronous circuit and an output of the generation circuit to the internal circuit respectively in the test mode while supplying the input from the pin to the internal circuit in the normal mode. More preferably, the switching circuit includes a first switch provided between the pin and the synchronous circuit and turned on in the test mode, a second switch provided between the pin and the internal circuit and turned on in the normal mode, and a third switch provided between the generation circuit and the internal circuit and turned on in the test mode. [0032] In the test mode, the input received from the pin can be supplied to the synchronous circuit as a power supply voltage by employing the internally generated signal in place of a signal received from the normally used pin. [0033] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0034] [0034]FIG. 1 is a diagram for illustrating the structure of a principal part of a semiconductor memory device according to a first embodiment of the present invention; [0035] [0035]FIG. 2 is a timing chart for illustrating operations of a synchronous circuit 101 ; [0036] [0036]FIG. 3 is a diagram for illustrating another structure of the principal part of the semiconductor memory device according to the first embodiment of the present invention; [0037] [0037]FIG. 4 is a diagram for illustrating the structure of a principal part of a semiconductor memory device according to a second embodiment of the present invention; [0038] [0038]FIG. 5 is a schematic diagram for illustrating a parallel test on a plurality of chips mounted on the same board; [0039] [0039]FIGS. 6 and 7 are diagrams for illustrating structures of a principal part of a semiconductor memory device according to a third embodiment of the present invention; [0040] [0040]FIG. 8 is a diagram for illustrating another exemplary structure of a circuit for detecting a leakage current; [0041] [0041]FIG. 9 illustrates the relation between check currents and internal voltages in normal and defective chips respectively; [0042] [0042]FIG. 10 is a diagram for illustrating still another exemplary structure of the circuit for detecting a leakage current; [0043] [0043]FIG. 11 is a diagram showing a circuit structure for latching an output of a comparator 127 ; [0044] [0044]FIG. 12 is a diagram for illustrating a semiconductor memory device according to a fourth embodiment of the present invention; [0045] [0045]FIG. 13 is a diagram for illustrating a logic circuit block 1001 shown in FIG. 12; [0046] [0046]FIG. 14 is a diagram showing an exemplary structure of a memory core part 1000 shown in FIG. 12; [0047] [0047]FIG. 15 is a diagram for illustrating the structure of a memory part 20 ; [0048] [0048]FIG. 16 is a diagram showing an outline of the structure of a reference voltage control circuit 13 ; [0049] [0049]FIG. 17 is a diagram showing an exemplary structure of the reference voltage control circuit 13 ; [0050] [0050]FIGS. 18 and 19 are diagrams showing exemplary association between a synchronous circuit 101 and an internal circuit group 102 ; and [0051] [0051]FIG. 20 is a diagram for illustrating a power source in a conventional semiconductor memory device. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0052] Embodiments of the present invention are now described with reference to the drawings. Parts identical or corresponding to each other are denoted by the same reference numerals, and redundant description is not repeated. [0053] [First Embodiment] [0054] The structure of a semiconductor memory device according to a first embodiment of the present invention is described with reference to FIG. 1. The semiconductor memory device shown in FIG. 1 comprises a synchronous circuit 101 , an internal circuit group 102 , a delay circuit 103 and a one-shot pulse generation circuit 104 . [0055] The synchronous circuit 101 is formed by a PLL (phase locked loop) circuit, a DLL (delay locked loop) circuit or the like. The synchronous circuit 101 is activated by an operation start trigger signal (a clock enable signal CKE going high upon activation of a chip in an SDRAM), initialized by an initialization pulse and thereafter generates an internal clock in response to a reference clock (e.g., an external clock). [0056] The delay circuit 103 delays and outputs the operation start trigger signal. The one-shot pulse generation circuit 104 generates a one-shot initialization pulse in response to the output from the delay circuit 103 . When a power supply voltage VCC goes high at a time t 0 , the clock enable signal CKE forming the operation start trigger signal goes high at a time t 1 , as shown in FIG. 2. Thus, the one-shot initialization pulse is generated. The synchronous circuit 101 starts a synchronous operation upon application of the initialization pulse, and generates the internal clock. [0057] Referring again to FIG. 1, the synchronous circuit 101 and the internal circuit group 102 are arranged between a power source 100 and a ground power source (ground voltage) GND. For simplifying the illustration, the power source 100 and the ground power source GND are hereinafter referred to as a power supply side and a GND side respectively. The internal circuit group 102 is formed by a memory cell array, a circuit controlling the operation of the memory cell array, an input/output buffer and the like. [0058] Exemplary association between the synchronous circuit 101 and the internal circuit group 102 is described with reference to FIG. 18. FIG. 18 shows an SDRAM including a clock buffer 1101 capturing an external clock ext.CLK and outputting an internal clock, a control signal buffer 1102 capturing an external control signal (e.g., a row address strobe signal /RAS) on the basis of the output from the clock buffer 1101 , an address buffer 1103 capturing an address signal A on the basis of the output from the clock buffer 1101 , a control circuit 1104 selecting a memory cell on the basis of the output from the clock buffer 1101 in response to outputs of the control signal buffer 1102 and the address buffer 1103 , a memory cell array 1105 including a plurality of memory cells, an input/output buffer 1106 connected with a data input/output pin DQ for outputting data from the selected memory cell or externally receiving data written in the selected memory cell, and an internal clock signal generation circuit 1110 receiving the external clock ext.CLK and generating an internal clock CLK repeating high and low states in a desired phase. Symbols VCC and VSS denote power supply pins. The input/output buffer 1106 operates with reference to the internal clock CLK. The internal clock signal generation circuit 1110 is formed by a PLL circuit or a DLL circuit. The synchronous circuit 101 shown in FIG. 1 corresponds to the internal clock signal generation circuit 1110 , for example. [0059] Referring again to FIG. 1, a VDC (voltage down convertor) circuit 200 including a differential amplifier 105 and a PMOS transistor 106 is arranged on the power supply side (voltage supply node NA) of the synchronous circuit 101 . The synchronous circuit 101 is supplied with an internal voltage from the node NA through the VDC circuit 200 . [0060] The PMOS transistor 106 is connected between the power source 100 and the node NA. The differential amplifier 105 has a positive input terminal connected with the node NA and a negative input terminal supplied with a reference voltage vref The differential amplifier 105 is activated in response to the clock enable signal CKE and operates on the basis of a voltage supplied from the power source 100 . The PMOS transistor 106 is rendered conductive in response to an output of the differential amplifier 105 . [0061] An NMOS transistor 109 for generating impedance is arranged on the GND side (voltage supply node NB) of the synchronous circuit 101 . The NMOS transistor 109 is connected between the ground power source GND and the node NB, and supplied with the power supply voltage in its gate. [0062] A capacitor 107 is arranged between the nodes NA and NB for stabilizing the voltage supplied to the synchronous circuit 101 . The capacitor 107 may be formed by a parallel flat capacitor, a MOS capacitor, a junction capacitor or a memory cell capacitor corresponding to a DRAM. [0063] A PMOS transistor 108 for feeding a dummy current is arranged between the node NA and the ground power source GND. The PMOS transistor 108 is rendered conductive in response to an inverted clock enable signal /CKE obtained by inverting the clock enable signal CLK. [0064] A VDC circuit 210 including a differential amplifier 110 and a PMOS transistor 111 is arranged on the power supply side (voltage supply node NC) of the internal circuit group 102 . The internal circuit group 102 is supplied with an internal voltage from the node NC through the VDC circuit 210 . [0065] The PMOS transistor 111 is connected between the power source 100 and the node NC. The differential amplifier 110 has a positive input terminal connected with the node NC and a negative input terminal supplied with the reference voltage vref. The PMOS transistor 111 is rendered conductive in response to an output of the differential amplifier 110 . A capacitor 112 is arranged between the node NC and the ground power source GND. [0066] The VDC circuit 200 and 210 are thus arranged on the power supply side thereby preventing the voltage of the voltage supply node NA from vibrating in association with noise generated following the operation of the internal circuit group 102 . Thus, the synchronous circuit 101 can be supplied with a stable voltage. [0067] Also when the node NA is influenced by noise, the voltages of the nodes NA and NB can be changed in the same direction due to the coupling effect of the capacitor 107 arranged between the power supply side and the GND side of the synchronous circuit 101 . In other words, the operating voltage (voltage between the nodes NA and NB) of the synchronous circuit 101 is kept constant. [0068] Further, the operation of the differential amplifier 105 for generating the voltage of the node NA is stabilized due to the provision of the path (the presence of the PMOS transistor 108 ) for feeding the dummy current. The differential amplifier 105 can stably operate against noise. [0069] The synchronous circuit 101 operates in a chip active period when the clock enable signal CKE goes high. Therefore, the dummy current, which is fed in response to the clock enable signal CKE, is cut while the clock enable signal CKE is low (power down state) for reducing current consumption. Thus, the inverted clock enable signal /CKE is supplied to a gate electrode of the PMOS transistor 108 . [0070] The GND side may also be influenced by noise. Therefore, the ON-state NMOS transistor 109 is arranged. The node NB is prevented from influence by noise through such on-state resistance. The NMOS transistor 109 raises the impedance of the node NB, thereby causing the coupling effect by the capacitor 107 . [0071] Another exemplary structure in the first embodiment of the present invention is described with reference to FIG. 3. The structure shown in FIG. 3 includes a PMOS transistor 113 , arranged between a power source 100 and a VDC circuit 200 , receiving a ground voltage GND in its gate. [0072] A filter utilizing on-state resistance of the PMOS transistor 113 is arranged for the power source 100 supplying a voltage to the VDC circuit 200 . The VDC circuit 200 serves as a filter for a synchronous circuit 101 against the power source 100 . [0073] Thus, two filters are serially arranged between the power source 100 and a node NA. Consequently, not only noise in a high-frequency operation but also noise over a wide frequency domain can be cut. [0074] [Second Embodiment] [0075] The structure of a semiconductor memory device according to a second embodiment of the present invention is described with reference to FIG. 4. After packaging a chip, it is difficult to separately provide an input pin for supplying a new power supply voltage to a test-system circuit. According to the second embodiment of the present invention, a normally used pin (pin used in a mode other than a test mode) is employed as a power supply pin for the test-system circuit. In the second embodiment of the present invention, a synchronous circuit 101 formed by a DLL circuit or the like outputs an internal clock, which is used only in the test mode (the output of the synchronous circuit 101 is hereinafter referred to as an internal test clock). [0076] A VDC circuit 200 , a capacitor 118 and a PMOS transistor 114 are arranged on a power supply side of the synchronous circuit 101 . According to the second embodiment of the present invention, a differential amplifier 105 included in the VDC circuit 200 operates in response to a test mode signal TEST. A PMOS transistor 106 is connected between a node NA and one conducting terminal of the PMOS transistor 114 . The capacitor 118 is connected between the node NA and a ground voltage GND. [0077] The PMOS transistor 114 is connected between a signal input pin PA receiving a signal A and the PMOS transistor 106 . The PMOS transistor 114 is rendered conductive in response to a test mode signal /TEST obtained by inverting the test mode signal TEST. [0078] An NMOS transistor 116 is arranged on a GND side of the synchronous circuit 101 . The NMOS transistor 116 is connected between a node NB and a signal input pin PB, and rendered conductive in response to the test mode signal TEST. [0079] In the structure shown in FIG. 4, the synchronous circuit 101 operates when the test mode signal TEST goes high (a specific test mode) and outputs the internal test clock. [0080] A circuit 115 provided for the signal input pin PA captures the signal A in response to the test mode signal /TEST and outputs an internal signal. A circuit 117 provided for the signal input pin PB captures a signal B in response to the test mode signal /TEST and outputs an internal signal. An internal circuit group 102 operates in response to the internal signal in a normal operation mode. A power supply structure for the internal circuit group 102 is identical to that described with reference to the first embodiment. [0081] The signal input pin PA is supplied with the signal A for a normal internal signal system (circuit 115 ) in the normal mode and supplied with the signal A of the power supply voltage level in the test mode. The signal input pin PB is supplied with the signal B corresponding to a normal internal signal system (circuit 117 ) in the normal mode and supplied with the signal B of the ground voltage level in the test mode. [0082] Thus, the signal input pins PA and PB can be used as power supply pins for the synchronous circuit 101 defining the test-system circuit. In this case, the internal signals are internally generated if necessary. Alternatively, a pin corresponding to an internal signal not used in the test mode is used as a power supply pin. [0083] Exemplary association between the synchronous circuit 101 and the internal circuit group 102 is described with reference to FIG. 19. In a semiconductor memory device shown in FIG. 19, a logic circuit block 1120 electrically interfacing with an external device, a memory core part 1122 including a memory cell array 1126 transmitting/receiving signals to/from the logic circuit block 1120 are formed on the same substrate. The logic circuit block 1120 transmits/receives signals to/from a device (not shown) through a plurality of external pins P 0 to Pn. The memory core part 1122 includes the memory cell array 1126 , a data input/output circuit 1128 , a controller 1124 controlling operations of the memory cell array 1126 and the data input/output circuit 1128 on the basis of signals received from the logic circuit block 1120 and an internal clock signal generation circuit 1130 . The internal clock signal generation circuit 1130 generates an internal test clock in a test mode. For example, the controller 1124 and the data input/output circuit 1128 operate with reference to the internal test clock output from the internal clock signal generation circuit 1130 in the test mode. [0084] In the test mode for the memory cell array 1126 , no signal may be input in the logic circuit block 1120 . After writing data once, for example, no pin is required for inputting data. At this time, signal supply on the side of the logic circuit block 1120 can be stopped. Therefore, the signal input pins P 0 and P 1 used for circuit operations of the logic circuit block 1120 in a normal mode are used as power supply pins for the internal clock signal generation circuit 1130 , generating the internal test clock in the test mode, included in the memory core part 1122 . [0085] The power supply structure for the synchronous circuit 101 is applicable not only to the synchronous circuit 101 but also to all test-system circuits driven only in a test mode. [0086] Thus, power supply pins in the test-system circuit can be dedicated by employing normally used pins not used in the test mode as power supply pins for the test-system circuit. Consequently, the test-system circuit is stabilized in operation, whereby a precise synchronous operation is implemented particularly in the synchronous circuit. [0087] [Third Embodiment] [0088] A parallel test for simultaneously testing a plurality of semiconductor memory devices mounted on the same board is now described. FIG. 5 is a schematic diagram for illustrating the parallel test testing a plurality of chips mounted on the same board. Symbols L 0 # 0 to L 0 # 2 denote signal lines and symbols L 1 # 0 to L 1 # 2 and L 2 # 0 to L 2 # 2 denote power supply lines respectively. [0089] A plurality of chips mounted on the same board and subjected to a parallel test share a power source and a signal (row address strobe signal RAS or the like). FIG. 5 representatively shows a plurality of chips 120 # 0 to 120 # 11 sharing the signal lines L 0 # 0 to L 0 # 2 and the power supply lines L 1 # 0 to L 1 # 2 and L 2 # 0 to L 2 # 2 . [0090] The signal lines L 0 # 0 to L 0 # 2 are coupled with each other and transmit the same signal to the chips 120 # 0 to 120 # 11 . The power supply lines L 1 # 0 to L 1 # 2 are coupled with each other and supply a voltage of the same level to the chips 120 # 0 to 120 # 11 . Similarly, the power supply lines L 2 # 0 to L 2 # 2 are coupled with each other and supply a voltage of the same level to the chips 120 # 0 to 120 # 11 . [0091] If part of the chips 120 # 0 to 120 # 11 is defective, the voltage of the shared power supply lines L 1 # 0 to L 1 # 2 and L 2 # 0 to L 2 # 2 or the voltage level of the shared signal lines L 0 # 0 to L 0 # 2 is reduced in the parallel test due to a leakage current flowing from this chip into the signal lines L 0 # 0 to L 0 # 2 or the power supply lines L 1 # 0 to L 1 # 2 and L 2 # 0 to L 2 # 2 . Such change of the voltage level disadvantageously influences the results of the test. In other words, a correct test cannot be made. [0092] Therefore, circuits for coping with generation of an abnormal current (leakage current) for each chip are provided as shown in FIG. 6. A circuit structure according to a third embodiment of the present invention shown in FIG. 6 is now described. [0093] A comparator 127 is arranged for comparing the voltage of a node NC with a prescribed voltage (vref/2 in FIG. 6). A differential amplifier 110 of a VDC circuit 210 operates in response to an output of an AND circuit 128 receiving an output from an output node NX of the comparator 127 and a clock enable signal CKE. [0094] A VDC circuit 130 is arranged for the node NC. The VDC circuit 130 includes a differential amplifier 131 and a PMOS transistor 132 . The differential amplifier 131 has a positive input terminal connected with the node NC and a negative input terminal supplied with a reference voltage vref. The PMOS transistor 132 is connected between a power source and the node NC and rendered conductive in response to an output of the differential amplifier 131 . The VDC circuit 130 is previously formed to be capable of limiting the quantity of current suppliable to an internal circuit group 102 . [0095] A differential amplifier 105 of a VDC circuit 200 operates in response to an output of an AND circuit 124 receiving the output of the node NX and a test mode signal TEST. [0096] When executing a parallel test on the plurality of chips in the arrangement shown in FIG. 5, the VDC circuit 130 is turned on while turning off the VDC circuits 200 and 210 for normal operations in a standby state. The “standby state” indicates a state after starting the parallel state and before activating the chips 120 # 0 to 120 # 11 . [0097] When the chip is normal, the VDC circuit 130 can normally supply an internal voltage. Therefore, the voltage of the node NX goes high due to comparison of the voltage of the node NC and the prescribed voltage vref/2. Consequently, the VDC circuit 210 for a normal operation is turned on when the chip is activated. When entering a specific test mode (the signal TEST goes high), the VDC circuit 200 is turned on to activate the synchronous circuit 101 . [0098] If the internal circuit group 102 is defective and generates a leakage current, however, the VDC circuit 130 cannot supply a sufficient current for supplementing the leakage current. Therefore, the voltage of the node NC is reduced. The voltage of the node NX goes low due to comparison of the voltage of the node NC and the prescribed voltage vref/2. In other words, generation of the leakage current is detected. [0099] When the leakage current is detected, the VDC circuit 210 is not turned on to activate the internal circuit group 102 even if the chip is activated. Also when entering the specific test mode (the signal TEST goes high), the VDC circuit 200 is not turned on to activate the synchronous circuit 101 . [0100] Therefore, the VDC circuits 210 and 200 are turned off for a defective chip in the parallel test. Thus, the remaining chips sharing the power supply lines and the signal lines can be prevented from influence by generation of the leakage current. [0101] When outputting presence/absence of generation of the leakage current, an output latch 122 is so formed as to latch data (data read from a memory cell) received from a general path and a signal of the node NX indicating presence/absence of generation of the leakage current (output of the comparator 127 ). Thus, presence/absence of generation of the leakage current is output through an output buffer 123 receiving data from the output latch 122 . [0102] While the determination level in the comparator 127 is vref/2 in the above description, the determination level is not restricted to this but can be arbitrarily set. A voltage for the determination level in the comparator 127 may be externally input or may be internally generated at an arbitrary level. [0103] The structure of the VDC circuit 130 is not restricted to that shown in FIG. 6 but a structure shown in FIG. 7 is also employable. Referring to FIG. 7, a VDC circuit 135 including PMOS transistors 136 and 137 is arranged in place of the VDC circuit 130 . The PMOS transistor 136 is connected between a power source and a node receiving an input from outside the chip, while the PMOS transistor 137 is connected between the power source and a node NC. Gates of the PMOS transistors 136 and 137 receive a signal from outside the chip. The PMOS transistors 136 and 137 form a current mirror circuit. Thus, the value of a check current for checking a leakage current can be switched by an external input. [0104] The VDC circuits 130 and 135 shown in FIGS. 6 and 7 are dedicated for leakage current detection. It is also possible to apply a general VDC circuit for supplying a small standby current provided on a chip to leakage current detection. [0105] [0105]FIG. 8 shows an exemplary VDC circuit for supplying a small standby current. The circuit shown in FIG. 8 includes a differential amplifier 131 and circuits 141 and 144 . [0106] The circuit 141 includes a PMOS transistor 142 rendered conductive in response to an external set switching signal and a PMOS transistor 143 rendered conductive in response to an output of the differential amplifier 131 . The PMOS transistors 142 and 143 are serially connected between a power source and the node NC. [0107] The circuit 144 includes a PMOS transistor 145 rendered conductive in response to the external set switching signal and a PMOS transistor 146 rendered conductive in response to the output of the differential amplifier 131 . The PMOS transistors 145 and 146 are serially connected between the power source and the node NC. [0108] Suppliability to the node NC is switched by selectively activating the circuits 141 and 144 in response to the set switching signal. [0109] When a leakage current is generated, an internal voltage is reduced due to insufficient current supply for holding the internal voltage. At this time, the internal voltage abruptly changes from a certain check current value, as shown in FIG. 9. Therefore, a defective chip can be readily detected by properly setting the check current value. [0110] In the aforementioned structure, the VDC circuits 200 and 210 do not operate in chip activation (specific timing) due to reduction of the internal voltage detected in the standby state. However, the present invention is not restricted to this but the detection may be performed in a prescribed test mode for latching the result of this detection so that the VDC circuits 200 and 210 are not turned on in chip activation. [0111] For example, the differential amplifier 131 is driven in response to a test mode signal ITST specifying a specific test mode, as shown in FIG. 10. The “test mode” indicates a mode for a current check test, which is different from the test mode in the parallel test. [0112] [0112]FIG. 11 illustrates a circuit structure for latching the output of the comparator 127 . Referring to FIG. 11, a switch 150 , an invertor 151 , a NAND circuit 152 and an invertor 153 are arranged for the comparator 127 . The switch 150 is turned in response to the test mode signal ITST for connecting a latch circuit formed by the invertor 151 and the NAND circuit 152 with the output of the comparator 127 . The NAND circuit 152 forming the latch circuit is reset in response to a reset signal RESET. The invertor 153 inverts an output of the latch circuit. The differential amplifier included in the VDC circuit is driven in response to the output of the invertor 153 . [0113] Thus, the semiconductor memory device according to the third embodiment of the present invention can detect a leakage current of a defective chip and prevent the leakage current from flowing out. Therefore, operations of the remaining chips arranged on the same board are guaranteed particularly in a parallel test. [0114] [Fourth Embodiment] [0115] An outline of a semiconductor memory device according to a fourth embodiment of the present invention is described with reference to FIGS. 12 to 15 . In the following description, it is assumed that signals provided with symbol “/” are those obtained by inverting signals provided with no such symbol “/”. [0116] As shown in FIG. 12, the semiconductor memory device according to the fourth embodiment of the present invention comprises a memory core part 1000 including a DRAM (dynamic random access memory) and a logic circuit block 1001 . The memory core part 1000 and the logic circuit block 1001 are formed on the same chip 1002 . An SRAM, a gate array, an FPGA, a nonvolatile RAM, a ROM and the like are also carried on the chip 1002 , although these elements are not illustrated. [0117] As shown in FIG. 13, the logic circuit block 1001 and the memory core part 1000 transmit/receive signals through connection nodes 2 a to 2 m. The logic circuit block 1001 transmits commands, addresses and data to the DRAM, while the DRAM responsively transmits data to the logic circuit block 1001 . [0118] The logic circuit block 1001 receives an external clock signal CLK, a command CMD and a reference voltage vref from pins 1 a , 1 b and 1 d respectively. The logic circuit block 1001 further inputs/outputs data DATA through a pin 1 c. [0119] The logic circuit block 1001 logically processes input signals and outputs corresponding signals to the memory core part 1000 . The reference voltage vref received through the pin 1 d is output to the node 2 m as such. [0120] As shown in FIG. 14, the memory core part 1000 is supplied with the following signals through the connection nodes 2 a to 2 k : The node 2 a supplies clock signals CLK and /CLK. The node 2 b supplies a clock enable signal CKE. The node 2 c supplies control signals, i.e., a signal ROWA indicating activation of a word line, a signal PC related to resetting (precharging) of the word line, a signal READ related to a read operation of a column related circuit, a signal WRITE related to a write operation of the column related circuit, a signal APC instructing an auto precharge operation, a signal REF related to a refresh operation and signals SRI and SWO related to a self refresh mode. [0121] Four commands of the signals ROWA, PC, READ, WRITE in total can be simultaneously generated at the maximum. [0122] The node 2 d supplies act bank signals AB 0 to AB 7 . The act bank signals AB 0 to AB 7 specify banks to be accessed in access to row and column respectively. The node 2 e supplies precharge bank signals PB 0 to PB 7 . The node 2 f supplies read bank signals RB 0 to RB 7 , and the node 2 g supplies write bank signals WB 0 to WB 7 . [0123] The node 2 h supplies act address signals AA 0 to AA 10 , the node 2 i supplies read address signals RA 0 to RA 5 , and the node 2 j supplies write address signals WA 0 to WA 5 . [0124] The node 2 k supplies input data DI 0 to DI 511 . Output data DQ 0 to DQ 511 from the memory core part 1000 are transmitted to the logic circuit block 1001 through the node 21 . [0125] The memory core part 1000 includes buffers 3 a to 3 l, a mode decoder 4 , an act bank latch 5 d , a precharge bank latch 5 e , a read bank latch 5 f , a write bank latch 5 g , a row address latch 5 h , a read address latch 5 i , a write address latch 5 j , a self refresh timer 6 , a refresh address counter 7 , a multiplexer 8 , predecoders 9 , 10 and 11 , a mode register 12 , a reference voltage control circuit 13 and a synchronous circuit 14 . [0126] The buffer 3 a receives the clock signals CLK and /CLK and outputs internal clock signals int.CLK and /int.CLK. Each of the buffers 3 c to 3 k is supplied with the reference voltage vref from the reference voltage control circuit 13 . The buffer 3 b receives the clock enable signal CKE. The buffer 3 c operates in response to an output of the buffer 3 b and captures the control signals received in the node 2 c . The mode decider 4 receives an output of the buffer 3 c and outputs internal control signals (signals ROWA, COLA, PC, READ, WRITE, APC and SR). [0127] The act bank latch 5 d latches the act bank signals AB 0 to AB 7 through the buffer 3 d . The precharge bank latch 5 e latches the precharge bank signals PB 0 to PB 7 through the buffer 3 e . The read bank latch 5 f latches the read bank signals RB 0 to RB 7 through the buffer 3 f . The write bank latch 5 g latches the write bank signals WB 0 to WB 7 through the buffer 3 g . The row address latch 5 h latches the act address signals AA 0 to AA 10 through the buffer 3 h . The read address latch 5 i latches the read address signals RA 0 to RA 5 through the buffer 3 i . The write address latch 5 j latches the write address signals WA 0 to WA 5 through the buffer 3 j. [0128] The buffer 3 k captures the input data DI 0 to DI 511 . The buffer 31 captures data output from a data input/output circuit 15 and outputs the same to the node 21 . [0129] The self refresh timer 6 receives the signal SR output from the mode decoder 4 and starts an operation. The refresh address counter 7 generates an address for performing a refresh operation in accordance with an instruction of the self refresh timer 6 . The multiplexer 8 outputs the output from the row address latch 5 h in a normal operation, while outputting the output of the refresh address counter 7 in a self refresh operation. The predecoder 9 predecodes a row address received from the multiplexer 8 . The predecoder 10 decodes a column address received from the read address latch 5 i . The predecoder 11 decodes a column address received from the write address latch 5 j . The mode register 12 holds information (e.g., data corresponding to a burst length) corresponding to a prescribed operation mode in response to the output of the row address latch 5 h. [0130] A global data bus GIO 1 transmits data read from a memory part 20 to the data input/output circuit 15 . A global data bus GIO 2 transmits input data received in the data input/output circuit 15 to the memory part 20 . [0131] The memory part 20 is divided into banks BANK 0 to BANK 7 , as shown in FIG. 15. Each bank includes a plurality of memory cells arranged in rows and columns, a plurality of word lines arranged in correspondence to the rows, and a plurality of bit lines arranged in correspondence to the columns. Each memory cell is formed by a memory cell capacitor storing information in the form of charges and a memory cell transistor having a gate electrode connected with a corresponding word line, a first conducting terminal connected with a corresponding bit line and a second conducting terminal connected with the memory cell capacitor. [0132] A row decoder 21 and a column decoder 22 are arranged for each bank. The row decoder 21 selects a corresponding row direction in response to the output of the predecoder 9 . The column decoder 22 selects the corresponding column direction in response to the outputs of the predecoders 10 and 11 . [0133] The banks BANK 0 to BANK 7 transmit/receive data to/from the global data buses GIO 1 and GIO 2 through an I/O port 23 . [0134] Each bank is controlled by a bank address. The bank address exists in correspondence to each command. For example, a word line of the corresponding bank is activated in accordance with the signal ROWA and the act bank signal ABn (n=0 to 7). The word line of the corresponding bank is reset in accordance with the signal PC and the precharge bank signal PBn (n=0 to 7). Data is read from a sense amplifier of the corresponding bank in accordance with the signal READ and the read bank signal RBn (n=0 to 7). Data is written in the sense amplifier of the corresponding bank in accordance with the signal WRITE and the write bank signal WBn (n=0 to 7). [0135] The relation between the reference voltage control circuit 13 and the synchronous circuit 14 is now described. The synchronous circuit 14 formed by a PLL circuit or the like generates an internal test clock in a test mode. [0136] In the test mode, the memory core part 1000 operates with reference to the internal test clock in place of the internal clock int.CLK output from the buffer 3 a , for example. Alternatively, a partial circuit (data input/output circuit 15 ) operates with reference to the internal test clock in place of the internal clock int.CLK. [0137] As shown in FIG. 16, the reference voltage control circuit 13 includes a vref generation circuit 40 and a switching circuit 41 . The vref generation circuit 40 generates a reference voltage in response to the test mode signal TEST. [0138] In the test mode, the switching circuit 41 connects the pin 1 d (node 2 m ) with a power supply line L 3 for supplying a voltage to the synchronous circuit 14 and electrically connects an internal vref line L 4 supplying the reference voltage to the buffers 3 c to 3 k with an output node of the vref generation circuit 40 . In a normal mode, the switching circuit 41 electrically connects the pin 1 d with the internal vref line L 4 . [0139] In the normal mode, the reference voltage vref input from the pin 1 d (external) decides the threshold voltages of the input buffers 3 c to 3 k . At this time, the synchronous circuit 14 , which is a test-system circuit, is stopped. In the test mode, the pin 1 d is used as a pin for supplying a power supply voltage to the synchronous circuit 14 . At this time, the internally generated reference voltage is supplied to the buffers. [0140] A specific example of the reference voltage control circuit 13 is described with reference to FIG. 17. The switching circuit 41 is formed by NMOS transistors 30 , 31 and 32 . Each of the NMOS transistors 30 and 32 receives the test mode signal TEST in its gate, while the NMOS transistor 31 receives the test mode signal /TEST in its gate. [0141] The NMOS transistor 30 is arranged between the internal vref line L 4 and the output node of the vref generation circuit 40 . The NMOS transistor 32 is arranged between the pin 1 d (node 2 m ) and the power supply line L 3 . The NMOS transistor 31 is arranged between the pin 1 d (node 2 m ) and the internal vref line L 4 . The vref generation circuit 40 generates a prescribed reference voltage vref in response to the test mode signal TEST. [0142] The voltage of the internal vref line L 4 changes in response to a signal output from the vref generation circuit 40 when the test mode signal TEST goes high, and changes in response to the reference voltage vref received in the pin 1 d when the test mode signal TEST goes low in the normal mode. [0143] When the test mode signal TEST goes high, the voltage of the power supply line L 3 changes in response to the voltage received in the pin 1 d. [0144] Thus, the pin 1 d used in the normal mode can be used as a pin for supplying the power supply voltage without separately providing an input pin for supplying the power supply voltage to the test-system circuit (synchronous circuit). Consequently, a stable power supply voltage can be supplied to the test-system circuit. [0145] Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.

The inventive semiconductor memory device comprises a synchronous circuit formed by a PLL circuit requiring precise operations, an internal circuit group and a VDC circuit. The VDC circuit, a capacitor, a PMOS transistor for a dummy current and an NMOS transistor serving as a high impedance element are arranged for the synchronous circuit. The VDC circuit is arranged for the internal circuit group. The VDC circuit eliminates power supply noise. The PMOS transistor stabilizes the operation of a differential amplifier of the VDC circuit. The capacitor keeps potential difference between a power supply side and a GND side constant. The NMOS transistor stabilizes the voltage on the GND side.

CROSS REFERENCE TO RELATED APPLICATION [0001] The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 2010-0086825 (filed on Sep. 6, 2010), which is hereby incorporated by reference in its entirety. BACKGROUND OF THE INVENTION [0002] 1. Technical Field [0003] The present disclosure relates to an outdoor unit for an air conditioner. [0004] 2. Description of the Related Art [0005] Generally, the air conditioner is an apparatus for cooling or heating air based on a refrigeration cycle including a compressor, a condenser, an evaporator and an expansion member. [0006] One of the condenser and the evaporator that is placed outdoors is heat-exchanged with outside air and the heat exchanger placed outdoors is called an outdoor unit. [0007] The heat exchanger situated inside the outdoor unit and an outdoor fan suctioning outdoor air to the inside of the outdoor unit and discharging to the outside of the outdoor unit are mounted. [0008] For a general outdoor unit, the outdoor fan is mounted in the rear of the discharge port and the heat exchanger performing a function of the condenser or the evaporator is placed in the rear of the outdoor fan. [0009] A grille is formed in the discharge port of the outdoor unit, such that the introduction of foreign substance from the outside or the entrance of person's hands is prevented. Since the discharge port of an existing outdoor unit is maintained in opened condition regardless of whether or not the operation of the outdoor, when the outdoor unit is not operating, there is a disadvantage that the foreign substance is introduced into the inside of the outdoor unit via the discharge port. Particularly, in the desert regions, small particles of sand is introduced into the inside of the outdoor unit to degrade the operating performance of the outdoor unit. SUMMARY OF THE INVENTION [0010] The disclosure proposed to improve above disadvantage is to provide opening and closing structure of the discharge port of the outdoor unit in which the discharge port of the outdoor unit is closed when not operating the outdoor unit and is opened only when operating the outdoor unit. [0011] An outdoor unit for an air conditioner according to an exemplary embodiment of the disclosure to achieve above objects, comprising: a case forming shape and having a suction port suctioning outside air and a discharge port discharging the suctioned air; a heat exchanger accommodated inside the case; a fan that is accommodated inside the case and forcibly circulate air; and a louver assembly rotatably mounted in the case so as to selectively open and close the discharge port. [0012] An outdoor unit for an air conditioner according to an exemplary embodiment of the disclosure including above configuration may obtain the same effects as below. [0013] First, since the discharge port of the outdoor unit is opened only when operating the outdoor unit, the introduction of the foreign substance may be prevented via the discharge port when not operating the outdoor unit. [0014] Further, when the discharge port of the outdoor unit is selectively closed by the louvers and the louvers close the discharge port of the outdoor unit, an advertisement or a picture may be attached to the surface of the louver, such that there is an advantage that may beautifully design a shape of the outdoor unit. In other words, there is a advantage that may use the front of the outdoor unit as an advertising board. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 is a front perspective view of an outdoor unit showing a condition in which a discharge port is opened, as an outdoor unit for an air conditioner according to an exemplary embodiment of the disclosure. [0016] FIG. 2 is a front perspective view of an outdoor unit showing a condition in which a discharge port is closed. [0017] FIG. 3 show a louver structure according to a first embodiment of the disclosure, as a cross-sectional view taken along line I-I of FIG. 2 . [0018] FIG. 4 shows schematically a louver driving mechanism according to a second embodiment of the disclosure. [0019] FIG. 5 shows a portion of the rear of the outdoor unit case equipped with the louver driving mechanism. [0020] FIG. 6 shows schematically a form in which the louver is connected to the louver driving mechanism. [0021] FIG. 7 is a front view of the outdoor unit showing schematically the louver driving mechanism according to a third embodiment of the disclosure. [0022] FIG. 8 is a cross-sectional view showing a process in which the louvers close the discharge port of the outdoor unit, as a cross section view taken along line II-II of FIG. 7 . [0023] FIG. 9 is a cross-sectional view showing a condition when the louvers close perfectly the discharge port of the outdoor unit. [0024] FIG. 10 shows the louver structure according to a fourth embodiment of the disclosure DESCRIPTION OF THE PREFERRED EMBODIMENTS [0025] Hereinafter, an outdoor unit of an air conditioner in an exemplary embodiment of the disclosure will be described in detail with reference to the drawings. [0026] FIG. 1 is a front perspective view of an outdoor unit showing a condition in which a discharge port is opened, as an outdoor unit for an air conditioner according to an exemplary embodiment of the disclosure and FIG. 2 is a front perspective view of an outdoor unit showing a condition in which a discharge port is closed. [0027] In FIG. 1 and FIG. 2 , an outdoor unit 10 for an air conditioner of an exemplary embodiment of the disclosure includes a case 11 forming a shape, a heat exchanger (not shown) accommodated inside the case, and a fan 14 (refer to FIG. 3 ) arranged in front of the heat exchanger. [0028] In detail, an discharge port 111 is formed in a front of the outdoor unit 10 and a suction port (not shown) is formed in a side of the outdoor unit 10 . Further, a discharge grille 12 is formed in the discharge port 111 and blocks putting your hands or entering bulky foreign substance from the outside. The discharge grille 12 may be composed by a combination of a plurality of ribs extending in all directions from a center of the discharge port 111 and a plurality of circular ribs having a diameter different from each other. However, it is revealed that the discharge grille 12 is not limited to the same structure as above. In addition, the discharge grille 12 is fixed to the front of the case 11 i.e. an edge of the discharge port 111 . Alternatively, the discharge grille 12 may be made in one body with the case 11 . [0029] In addition, a plurality of louvers 13 can be installed rotatably in the front of the discharge grille 12 . When not driving the outdoor unit 10 , the upright louvers 13 close perfectly the discharge ports 111 , and the outdoor unit 10 rotates frontward during its driving process to allow the discharge port 111 to be opened. [0030] Hereinafter, the structure and operations of the louvers 13 will be described in detail with reference to drawings. [0031] FIG. 3 shows a louver structure according to a first embodiment of the disclosure, as a cross-sectional view taken along line I-I of FIG. 2 . [0032] In FIG. 3 , the plurality of louvers 13 can be placed horizontally or vertically. In addition, the louvers 13 close perfectly the discharge port 111 under condition parallel to the front of the case 11 . [0033] In detail, both ends of each of the plurality of louvers 13 are rotatably connected to the edge of the discharge port 111 . First, it is described that the plurality of louvers 13 are placed in the horizontal direction and arranged adjacently to each other in the vertical direction. [0034] When the plurality of louvers 13 are placed in the horizontal direction, a rotation axis may be protruded from both side ends of each louver 13 . In addition, the rotation axis may be formed in the top end of the side end of the louvers 13 . According to such a structure, when the fan 14 is driven and the suctioned outdoor air is discharged to the discharge port 111 , the louvers 13 rotate frontward by air pressure to be discharged above. Further, if the fan 14 is stopped, each of the louvers 13 returns to its original position by gravity to maintain an upright condition. When the louvers 13 is in the upright condition, the discharge port 111 is completely closed. Therefore, there is a advantage that a separate driving mechanism rotating the louvers 13 is not needed. [0035] In addition, since the discharge grille 12 is arranged in the rear of the louvers 13 , when the fan 14 is stopped, a phenomenon that the louvers 13 rotate inside the outdoor unit 10 can be prevented by wind blowing into the inside of the outdoor unit 10 from the outside of the outdoor unit 10 . [0036] On the other hand, when the louvers 13 are vertically combined to the discharge port 111 , since it is impossible to rotate due to gravity of the louvers 13 , the rotation axis of the louvers 13 is equipped with elastic members such as a torsion spring at this time. In other word, when wind pressure generated by driving of the fan 14 acts to the louvers 13 , the louvers 13 rotate frontward. Then, when the fan 14 is stopped, the louvers 13 may return to its original position by force of restoration of the elastic member (refer to FIG. 10 ). [0037] Alternatively, the driving mechanism to allow the louvers 13 to rotate selectively will be applied. The description about this will be described with reference to the drawings below. [0038] FIG. 4 shows schematically a louver driving mechanism according to a second embodiment of the disclosure, FIG. 5 shows a portion of the rear of the outdoor unit case equipped with the louver driving mechanism and FIG. 6 shows schematically a form in which the louvers are connected to the louver driving mechanism. [0039] In FIG. 4 to FIG. 6 , A connection bar 22 is extended to one or both ends of the louvers 13 and a pinions 21 is mounted in the end of the connection bar 22 . In addition, a racks 20 may be arranged in the front or rear of the pinions 21 . Further, the pinions 21 may be gear-coupled with the racks 20 . The racks 20 is formed with lengths that may be gear-coupled with both of the pinions 21 connected to uppermost louvers 13 and the pinions 21 connected to lowermost louvers 13 . Further, the racks 20 may be mounted inside the case 11 to enable reciprocal movement along the length of the racks 20 . [0040] Further, a driving motor M may be connected to any one of the pinions 21 connected to the louvers 13 , for example, the lowermost or uppermost pinions 21 . [0041] According to such a configuration, when the driving motor M is operated, the pinions 21 connected to the driving motor M rotates. Further, the racks 20 engaged with the pinions 21 is moved upward or downward on the drawings. Therefore, another pinions gear-coupled with the rack 20 rotate together, too, such that the entire louvers 13 rotate at the same rotational speed and the discharge port 111 is opened or closed selectively. [0042] On the other hand, another mechanism in addition to the rack and pinion structure may be applied as a method for rotating simultaneously a plurality of the pinion 21 connected to the louvers 13 , respectively. For example, time belt type belts may be applied instead of the rack 20 . In other words, gear teeth are formed in inner principal plan of the belt and the plurality of pinions 21 may be engaged with the gear teeth formed in inner principal plan of the belt. Further, when the driving motor is connected to the uppermost or the lowermost pinion 21 , another pinions 21 also rotate at the same speed according to the rotation of the belt. [0043] Further, in addition to the time belt type belt, a chain type sprocket assembly may be applied. [0044] The pinion described above is called “a first power delivery member” and the rack, the time belt or the sprocket assembly is called “a second power delivery member”. [0045] FIG. 7 is a front view of the outdoor unit showing schematically the louver driving mechanism according to a third embodiment of the disclosure, FIG. 8 is a cross-sectional view showing a process in which the louvers close the discharge port of the outdoor unit, as a cross section view taken along line II-II of FIG. 7 and FIG. 9 is a cross-sectional view showing a condition when the louvers close perfectly the discharge port of the outdoor unit. [0046] Referring to FIG. 7 to FIG. 9 , the discharge port 111 of the outdoor unit 10 according to the disclosure may be selectively closed by the plurality of louvers 13 extending in all directions. The plurality of louvers 13 may be arranged to be overlapped with each other. In other word, a portion of one louver may be arranged to be vertically overlapped with a portion of another louver (refer to FIG. 8 ). [0047] Specifically, the driving motor may be mounted in the center of the discharge grille 12 and the louver assembly having a fan type may be mounted in the front of the discharge grille 12 . In other words, the louver assembly, in which the plurality of louvers 13 having the fan type are connected to each other, is mounted and the inner end of the louver 13 connected to its edge is connected to the rotation axis of the motor M. According to this configuration, as shown in FIG. 7 and FIG. 8 , when the driving motor M is rotated to rotate the louvers 13 connected to the edge, the discharge port 111 is closed while unfolding the plurality of louvers 13 in a fan type. [0048] Further, the discharge port 111 may be perfectly closed by unfolding one louver assembly circularly and as shown in FIG. 7 , short louver assemblies are provided in combined type to enable the discharge port 111 to be closed. For example, the discharge port 111 is to be quartered and four louver assemblies may be circularly surrounded in the inside of the discharge port 111 . Further, each louver 13 situated at the edge are connected to the rotation axis of the driving motor M. In this condition, when the driving motor M rotates, four louver assemblies cover by ¼ of the discharge port 111 area to perfectly close the discharge port 111 in total. [0049] On the other hand, one side of each louver 13 is convexly rounded as shown in FIG. 8 and FIG. 9 and the other side is concavely rounded. Then, when the louver assembly is in fully unfolded condition as shown in FIG. 9 , there is no gap between adjacent louvers. In other words, the plurality of louvers may be arranged in one column side by side without overlapping with each other. [0050] In addition, when the louver assembly is in the folding process, one of the louvers 13 is smoothly sled along the side of the adjacent louvers 13 so as to be positioned on the rear of the adjacent louvers 13 . [0051] FIG. 10 shows the louver structure according to a fourth embodiment of the disclosure. [0052] In the FIG. 10 , the louvers 13 according to the fourth embodiment of the disclosure may be rotatably coupled with the discharge port 111 vertically. [0053] The louvers 13 are provided with the rotation axis 17 forming the rotation center of the louvers 13 . An elastic member 18 providing force of restitution to the louvers 13 is coupled with the rotation axis 17 . The elastic member 18 includes a torsion spring. [0054] When the fan 14 rotates, the louvers 13 overcome the elastic force of the elastic member 18 so as to rotate with one direction. Further, the discharge port 111 is opened and air of the inside of the outdoor unit 10 is discharged outside. [0055] On the other hand, when the driving of the fan 14 is stopped, the louvers 13 rotate at its original position by force of restoration of the elastic member 18 so as to close the discharge port 111 . [0056] In summary, when wind pressure generated by driving of the fan 14 acts to the louvers 13 , the louvers 13 rotates frontward. Then, when the fan 14 is stopped, the louvers 13 may return to its original position by force of restoration of the elastic member. [0057] In such a configuration, opening and closing of the louvers 13 may be easily achieved by a simple configuration.

An outdoor unit for an air conditioner according to an exemplary embodiment of the disclosure, comprising: a case forming shape and having a suction port suctioning outside air and a discharge port discharging the suctioned air; a heat exchanger accommodated inside the case; a fan that is accommodated inside the case and forcibly circulate air; and a louver assembly revolvably mounted in the case so as to selectively open and close the discharge port.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to secondary image forming type finder optical devices and, more particularly, to secondary image forming type finder optical devices provided with an objective lens solely used therefor separately from the photographic lens and having a predetermined optical total length, which devices are suited to, for example, electronic still cameras or video cameras. 2. Description of the Related Art Recently, a variety of kinds of photographic systems on the electronic still camera which magnetically records video information in the small-sized floppy disc have been proposed. Of these proposals, particularly for the finder optical device, various types are adopted. The electronic still camera differs largely from the conventional camera for silver halide photosensitive material in the shape of the entirety of the camera depending on how to arrange the floppy disc in the camera body. For example, in the case of containing the floppy disc in a chamber whose plane is parallel to the optical axis of the photographic lens, the shape becomes an axially elongated one as in the motion video camera of the unified type of recorder and reproducer, or the like. The so-called reverse Galilean finder optical device which has so far been suited well to the external finder optical device for the silver halide camera, and the real image finder optical device of the primary image forming type using the prism for non-reverse erecting image, when applied to the electronic still camera, etc., because of their optical total length being too short, have given rise to, for example, the following problems. That is, to secure a sufficiently long eye point by arranging the eyepiece lens of the finder optical device at or near the rear plane of the camera, the shortage of the optical total length of the finder optical device causes the front vertex of the objective lens to be arranged in a considerably secluded position from the front plane of the camera. For this reason, to secure the finder light beam without eclipse, the size of the opening portion for the finder optical device in the front panel of the camera housing must be increased, which calls for an increase of the distance from the optical axis of the photographic lens to that of the finder optical device. Thus, a problem of intensifying the finder parallax and others arose. The conventional secondary image forming type finder optical devices for use in the video cameras or the like, on the other hand, generally become too long in the axial direction. Hence, they are not very suited to be used in, for example, electronic still cameras. SUMMARY OF THE INVENTION An object of the present invention is to provide a secondary image forming type finder optical device wherein light from a finder image formed by an objective lens unit is further focused by a relay lens unit or the like to form a non-reverse erecting finder image to be observed through an eyepiece lens unit, and wherein the construction and arrangement and the refractive powers of the constituent lenses of each lens unit are so properly designed that the optical total length takes a desired value, while still permitting the possibility of observing a finder image of high quality. Another object is to provide a secondary image forming type finder optical device suited to the electronic still camera or video camera. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to FIG. 3 are lens block diagrams illustrating numerical examples 1-3 of the invention. FIG. 4 to FIG. 6 are aberration curves corresponding to the numerical examples 1-3, respectively, with an object distance of 3 m. FIG. 7 to FIG. 9 are lens block diagrams illustrating numerical examples 4-6 of the invention. FIG. 10 to FIG. 12 are aberration curves corresponding to the numerical examples 4-6, respectively, with an object distance of 3 m. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 to FIG. 3 and FIG. 7 to FIG. 9 schematically show numerical examples 1 to 6 of embodiments of finder optical devices according to the invention, respectively. It should be noted that the finder optical device of the invention is arranged separately from the photographic lens (not shown). In FIG. 1 to FIG. 3, T is an objective lens unit comprising two positive lenses Ta and Tb arranged so that their lens surfaces of strong curvature face each other. Incidentally, the lens Tb plays chiefly the role of a field lens. A relay lens unit R comprises a negative lens Ra and a positive lens Rb. A field lens unit F is arranged in the neighborhood of a secondary image plane Q, and comprises a positive lens convex toward the front. An eyepiece lens unit E comprises two positive lenses Ea and Eb arranged so that their lens surfaces of strong curvature face each other. In the secondary image forming type finder optical device in this embodiment, at first, the objective lens unit T forms a first finder image on a primary image plane P, and the relay lens unit R and the field lens unit F then focus the light from the first finder image to form a non-reverse erecting second finder image on a secondary image plane Q. And, the non-reverse erecting second finder image formed on the secondary image plane Q is made to be observed by the eyepiece lens unit E. The finder optical device of the invention satisfies the following conditions: 1.0<f.sub.R /f.sub.T <1.8 . . . (1) 1.0<f.sub.F /f.sub.E <1.7 . . . (2) where f T , f R , f F and f E are respectively the focal lengths of the objective lens unit T, the relay lens unit R, the field lens unit F and the eyepiece lens unit E. The inequalities of condition (1) concern with the refractive power arrangement of the relay lens unit R and the objective lens unit T, which is most important in the present embodiment. Now, on the assumption that the focal length of the photographic lens and the finder field rate are constant, it is possible that, as the composite focal length f T of the objective lens unit T increases, the finder magnification increases. But, because the magnification at the primary image plane P becomes large, the secondary image forming system comprised of the relay lens unit R and the field lens unit F gets harder to correct for aberrations. Meanwhile, the secondary image forming system, when the image magnification is unity, has a shortest optical total length, taking a value of about 4f R . Thus, the shorter the focal length of the relay lens unit R, the more advantageously the optical total length is shortened, but the more difficult the aberration correction becomes. On account of such a reason as described above, in the present embodiment, the focal lengths of the objective lens unit T and the relay lens unit R are made so determined that their ratio or f R /f T satisfies the condition (1). When the lower limit of the inequalities of condition (1) is exceeded, it is advantageous for the finder magnification and the shortening of the optical total length, but the Petzval image surface gets harder to correct well. When the upper limit is exceeded, on the other hand, the optical total length is increased objectionably, although the aberrations can advantageously be corrected. The inequalities of condition (2) have a main aim to minimize the diameter of the relay lens unit R. In this embodiment, the focal lengths of the field lens unit F and the eyepiece lens unit E are made so determined that the principal ray of the off-axis pupil which is to pass through the center of the observation pupil passes through almost the center of the relay lens unit R. Therefore, despite the strengthening of the refractive power of the relay lens unit R, the light beam which would otherwise be refracted from the marginal zone of the lens can be avoided. Hence, the good quality can be secured over the entire area of the observation pupil. When the upper limit of the inequalities of condition (2) is exceeded, the diameter of the relay lens unit R increases largely, and the diameter of the eyepiece lens unit E also becomes larger. Conversely when the lower limit of the inequalities of condition (2) is exceeded, the diameter of the relay lens unit R becomes larger, the curvature of field produced in the field lens unit F becomes impossible to correct. Next, when the relay lens unit R is constructed in the cemented form as shown in FIGS. 1 to 3, conditions for preserving good optical performance are given below. They are for the refractive indices N N and N P of the materials of the negative lens Ra and the positive lens Rb of the relay lens unit R respectively, the Abbe numbers ν N and ν P of the materials of the negative lens Ra and the positive lens Rb of the relay lens unit R respectively and the radius of curvature RA of the cemented lens surface of the relay lens unit R to satisfy the following conditions: ##EQU2## Particularly, the relay lens unit R is constructed so as to satisfy the conditions (3) to (5), and the objective lens unit T and the eyepiece lens unit E each are constructed with the two lenses whose confronting surfaces are of strong curvature, so that the various aberrations are well canceled in each lens unit itself, thus achieving good balance of aberration correction. The inequalities of condition (3) concern with the radius of curvature of the cemented lens surface of the relay lens unit R. When the upper limit is exceeded, the curvature of field becomes difficult to correct. Conversely when the lower limit is exceeded, the spherical aberration on the secondary image plane Q becomes over-corrected. The inequalities of conditions (4) and (5) concern with the refractive indices and Abbe numbers of the materials of the negative lens Ra and the positive lens Rb constituting the relay lens unit R. Mainly the condition (4) concerns with the refractive index difference for enabling the curvature of field to be corrected well, and the condition (5) concerns with the Abbe number difference for enabling, among others, the longitudinal chromatic aberration to be corrected. When the condition (4) is violated, the curvature of field toward the marginal zone of the image frame becomes larger. Also, when the condition (5) is violated, the chromatic aberration increases. In any case, it becomes difficult to obtain the good finder image. It should be noted that of the singlet lenses constituting the objective lens unit, the field lens unit and eyepiece lens unit, arbitrary one or ones may otherwise be constructed in cemented form, comprising a positive lens and a negative lens cemented together. According to this, a finder optical device better corrected for chromatic aberrations and other aberration and having a higher grade of optical performance can be achieved. Next, desirable conditions in another embodiment which is different from the embodiment of FIGS. 1 to 3 in that the relay lens unit of the finder optical device is divided as shown in FIGS. 7 to 9 are shown. It should be noted that this embodiment, too, satisfies the above-described conditions (1) and (2). The objective lens unit T comprises two positive lenses Ta and Tb arranged so that their lens surfaces of strong curvature face each other. Incidentally, the lens Ta may be made up by a plurality of lenses for the purpose of improving aberration correction. Also, the lens Tb plays the role of a field lens. Hence the primary image is formed in the neighborhood of the lens Tb. The relay lens unit R comprises a lens Ra of positive refractive power and a lens Rb of negative refractive power. An air lens is formed between the lenses Ra and Rb. The curvature of one of lens surfaces of the lens Ra of positive refractive power which faces the lens Rb of negative refractive power is stronger than that of the other surface. The field lens unit F comprises one positive lens turning its strong convexity to the object side. A secondary image is formed in the neighborhood of the field lens unit F. The eyepiece lens unit E comprises two positive lenses Ea and Eb, the surfaces of strong curvature of the lenses Ea and Eb facing each other. What is important in this embodiment is the refractive power arrangement of the relay lens unit R. In a case where the focal length of the photographic lens and the finder field rate are constant, a longer composite focal length of the objective lens unit T enables the finder magnification to be greater, but causes the size at the primary image plane to get larger. Thus, the difficult point is in the aberration correction of the secondary image forming system. Meanwhile, the secondary image forming system, when the image magnification is unity, becomes shortest in the total length. The shorter the focal length of the relay lens unit R, the more advantageously the total length can be shortened, but the more difficult the aberrations become to correct. Next, conditions for maintaining the desired optical performance are set forth as follows: ##EQU3## where f P is the focal length of the lens Ra of positive refractive power of the relay lens unit R, ν P is the Abbe number of its material, R P is the radius of curvature of its lens surface of strong curvature, f N is the focal length of the lens Rb of negative refractive power of the relay lens unit R, ν N is the Abbe number of its material, and R N is the radius of curvature of its lens surface of strong curvature. The inequalities of condition (6) represent a preferable range on aberration correction for the focal lengths of the positive lens Ra and the negative lens Rb constituting the relay lens unit R when a shortening of the total length by strengthening the refractive power of the relay lens unit R is achieved. Since the composite focal length of the relay lens unit R has a positive refractive power, when the refractive power of the positive lens Ra becomes strong as exceeding the lower limit, although it is advantageous to shortening the total length, because the diverging action in the relay lens unit R weakens, under-corrected spherical aberration is produced. Meanwhile, when the refractive power of the negative lens Rb strengthens as exceeding the upper limit, it gets harder to achieve a shortening of the total length while well correcting the spherical aberration. The inequality of condition (7) concerns with the difference between the Abbe numbers of the materials of the positive lens Ra and the negative lens Rb constituting the relay lens unit R. When the difference between the Abbe numbers becomes smaller than the limit, correction of longitudinal chromatic aberration gets harder. The inequalities of condition (8) are to determine the shape of an air lens between the positive lens Ra and the negative lens Rb constituting the relay lens unit R. Incidentally, this air lens has a negative refractive power. When the upper limit is exceeded, spherical aberration and curvature of field both get under-corrected. Conversely when the lower limit is exceeded, both of the spherical aberration and the curvature of field get over-corrected objectionably. It will be appreciated from the foregoing discussion and is even apparent from the aberration curves of FIG. 10 to FIG. 12 that according to this embodiment, the relay lens unit R of the secondary image forming system is divided into the positive lens Ra and the negative lens Rb, and their refractive powers are properly arranged, whereby an increase of the degree of freedom on aberration correction and a shortening of the optical total length can be achieved. Another advantage arising from the use of the divided form of the relay lens R into the positive lens Ra and the negative lens Rb is that it becomes even possible to choose synthetic resin or the like as the optical material. Next, numerical examples 1 to 6 of the invention are shown. In the numerical examples 1 to 6, Ri is the radius of curvature of the i-th lens surface counting from front, Di is the i-th lens thickness or air separation counting from front, and Ni and νi are respectively the refractive index and Abbe number of the glass of the i-th lens element counting from front. Also, the relations of each of the before-described conditions (1) to (5) with the various numerical values in the numerical examples 1 to 3 are shown in Table-1. ______________________________________Numerical Example 1 (FIGS. 1 and 4):Exit Pupil Diameter φ3; Max. Emergence Angle tan Θ = 0.17______________________________________R1 = 33.14 D1 = 2.00 N1 = 1.49171 ν1 = 57.4R2 = -9.63 D2 = 9.43R3 = 7.79 D3 = 4.28 N2 = 1.49171 ν2 = 57.4R4 = ∞ D4 = 31.40R5 = 25.85 D5 = 0.72 N3 = 1.84666 ν3 = 23.9R6 = 7.24 D6 = 2.43 N4 = 1.77250 ν4 = 49.6R7 = -22.44 D7 = 29.00R8 = 10.62 D8 = 3.20 N5 = 1.49171 ν5 = 57.4R9 = ∞ D9 = 24.86R10 = ∞ D10 = 1.50 N6 = 1.49171 ν6 = 57.4R11 = -20.00 D11 = 0.15R12 = 20.00 D12 = 1.50 N7 = 1.49171 ν7 = 57.4R13 = ∞______________________________________ Note: The eye point lies 16 mm behind the vertex of the lens surface R13. f.sub.T = 11.35, f.sub.R = 18.0, f.sub.F = 21.61, f.sub.E = 20.37 ______________________________________Numerical Example 2 (FIGS. 2 and 5):Exit Pupil Diameter φ3; Max. Emergence Angle tan Θ = 0.17______________________________________R1 = ∞ D1 = 1.80 N1 = 1.77250 ν1 = 49.6R2 = -12.44 D2 = 9.60R3 = 7.85 D3 = 2.80 N2 = 1.49171 ν2 = 57.4R4 = -148.41 D4 = 28.89R5 = 17.85 D5 = 0.80 N3 = 1.84666 ν3 = 23.9R6 = 7.27 D6 = 2.60 N4 = 1.71300 ν4 = 53.8R7 = -18.74 D7 = 25.07R8 = 11.09 D8 = 2.40 N5 = 1.49171 ν5 = 57.4R9 = ∞ D9 = 22.01R10 = 144.93 D10 = 1.80 N6 = 1.49171 ν6 = 57.4R11 = -20.70 D11 = 0.15R12 = 20.70 D12 = 1.80 N7 = 1.49171 ν7 = 57.4R13 = - 144.93______________________________________ f.sub.T = 11.34, f.sub.R = 15.39, f.sub.F = 22.56, f.sub.E = 18.61 ______________________________________Numerical Example 3 (FIGS. 3 and 6):Exit Pupil Diameter φ3; Max. Emergence Angle tan Θ = 0.17______________________________________R1 = 5458.52 D1 = 2.60 N1 = 1.49171 ν1 = 57.4R2 = -8.01 D2 = 9.09R3 = 8.01 D3 = 2.60 N2 = 1.49171 ν2 = 57.4R4 = -5458.52 D4 = 32.92R5 = 17.72 D5 = 0.80 N3 = 1.84666 ν3 = 23.9R6 = 7.24 D6 = 2.60 N4 = 1.69680 ν4 = 55.5R7 = -20.84 D7 = 27.93R8 = 12.13 D8 = 2.40 N5 = 1.49171 ν5 = 57.4R9 = ∞ D9 = 22.07R10 = 389.49 D10 = 1.80 N6 = 1.49171 ν6 = 57.4R11 = -19.15 D11 = 0.15R12 = 19.15 D12 = 1.80 N7 = 1.49171 ν7 = 57.4R13 = -389.49______________________________________ f.sub.T = 11.30, f.sub.R = 17.0, f.sub.F = 24.68, f.sub.E = 18.66 TABLE 1______________________________________ Numerical ExampleCondition 1 2 3______________________________________(1) f.sub.R /f.sub.T 1.59 1.36 1.50(2) f.sub.F /f.sub.E 1.06 1.21 1.32(3) |RA|/f.sub.R 0.40 0.47 0.43(4) N.sub.N -N.sub.P 0.074 0.134 0.150(5) ν.sub.P -ν.sub.N 25.7 29.9 31.6______________________________________ ______________________________________Numerical Example 4 (FIGS. 7 and 10):Exit Pupil Diameter φ3; Max. Emergence Angle tan Θ = 0.17______________________________________R1 = 33.142 D1 = 2.00 N1 = 1.49171 ν1 = 57.4R2 = -9.632 D2 = 9.43R3 = 7.799 D3 = 4.28 N2 = 1.49171 ν2 = 57.4R4 = 0.000 D4 = 30.49R5 = 20.766 D5 = 2.43 N3 = 1.69680 ν3 = 55.5R6 = -7.369 D6 = 0.15R7 = -6.828 D7 = 0.72 N4 = 1.58347 ν4 = 30.2R8 = -45.349 D8 = 31.19R9 = 10.627 D9 = 3.20 N5 = 1.49171 ν5 = 57.4R10 = 0.000 D10 = 24.86R11 = 0.000 D11 = 1.50 N6 = 1.49171 ν6 = 57.4R12 = -20.000 D12 = 0.15R13 = 20.000 D13 = 1.50 N7 = 1.49171 ν7 = 57.4R14 = 0.000______________________________________ Note: The eye point lies 16 mm behind the vertex of the lens surface R14. f.sub.p = 8.09 f.sub.N = -13.87 ______________________________________Numerical Example 5 (FIGS. 8 and 11):Exit Pupil Diameter φ3; Max. Emergence Angle tan Θ = 0.17______________________________________R1 = 5032.000 D1 = 2.60 N1 = 1.49171 ν1 = 57.4R2 = -8.086 D2 = 9.05R3 = 8.086 D3 = 2.60 N2 = 1.49171 ν2 = 57.4R4 = -5032.000 D4 = 29.78R5 = 10.078 D5 = 0.80 N3 = 1.84666 ν3 = 23.9R6 = 6.343 D6 = 0.15R7 = 6.986 D7 = 2.45 N4 = 1.49171 ν4 = 57.4R8 = -11.800 D8 = 25.07R9 = 11.091 D9 = 2.40 N5 = 1.49171 ν5 = 57.4R10 = -5032.000 D10 = 23.13R11 = 144.930 D11 = 1.80 N6 = 1.49171 ν6 = 57.4R12 = -20.709 D12 = 0.15R13 = 20.709 D13 = 1.80 N7 = 1.49171 ν7 = 57.4R14 = -144.930______________________________________ f.sub.P = 9.33 f.sub.N = -22.41 ______________________________________Numerical Example 6 (FIGS. 9 and 12):Exit Pupil Diameter φ3; Max. Emergence Angle tan Θ = 0.17______________________________________R1 = 5458.520 D1 = 2.60 N1 = 1.49171 ν1 = 57.4R2 = -8.017 D2 = 9.09R3 = 8.017 D3 = 2.60 N2 = 1.49171 ν2 = 57.4R4 = -5458.520 D4 = 32.72R5 = 15.012 D5 = 0.72 N3 = 1.58347 ν3 = 30.2R6 = 4.807 D6 = 0.15R7 = 4.936 D7 = 2.50 N4 = 1.49171 ν4 = 57.4R8 = -11.802 D8 = 27.67R9 = 12.135 D9 = 2.40 N5 = 1.49171 ν5 = 57.4R10 = 0.000 D10 = 22.07R11 = 389.490 D11 = 1.80 N6 = 1.49171 ν6 = 57.4R12 = -19.154 D12 = 0.15R13 = 19.154 D13 = 1.80 N7 = 1.49171 ν7 = 57.4R14 = -389.490______________________________________ f.sub.P = 7.44 f.sub.N = -12.44

A secondary image forming type finder opitcal device having an objective lens solely used therefor, comprising, from front to rear, an objective lens unit including at least one positive lens, a relay lens unit formed by arranging a lens of positive refractive power and a lens of negative refractive power in spaced relation, a field lens unit consisting of a positive lens whose front surface is of strong curvature, and an eyepiece lens unit consisting of two positive lenses whose confronting surfaces are of strong curvature, satisfying the following conditions: ##EQU1## where f P is the focal length of the lens of positive refractive power of the relay lens unit, ν P is the Abbe number of its material, R P is the radius of curvature of a lens surface of the lens of positive refractive power of the relay lens unit which is of strong curvature and faces the lens of negative refractive power of the relays lens unit, f N is the focal length of the lens of negative refractive power of the relay lens unit, ν N is the Abbe number of its material, and R N is the radius of curvature of a lens surfaces of the lens of negative refractive power of the relay lens unit which is of strong curvature and faces the lens of positive refractive power of the relay lens unit.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ink-jet recording methods and recording apparatuses capable of providing high-quality images on a recording medium, and in particular, to an ink-jet recording method for discharging a printing-characteristic improving liquid causing recording ink on a recording medium and coloring material in the recording ink to become insoluble or to aggregate, and a recording apparatus for practicing the ink-jet recording method, which both enable high-speed printing. The ink-jet recording method and the apparatus are applicable specifically to office equipment with the recording apparatus as output means, such as printers, photocopiers and word processors, and manufacturing equipment such as textile printers for printing on textiles. 2. Description of the Related Art The ink-jet recording technique is conventionally used in printers, photocopiers and so forth because of that technique has advantages such as low noise, and reduced-size recording units. When an image is formed on a recording material of the type known as "plain paper" using a recording apparatus employing ink-jet recording, the image formed is not water-fast; the image may run if it becomes wet. When a color image is formed by ink-jet recording, it is practically impossible to produce a highly concentrated image without feathering and without blurring between colors. Thus, a color image having the desired image durability and quality cannot be obtained. In order to improve the water resistance of an image, ink having waterproof coloring material has recently been used for practical use. However, since in principle the ink still has insufficient water resistance, and becomes almost insoluble in water after it is dried, the ink easily clogs recording-head nozzles. Accordingly, to prevent such clogging, the recording apparatus structure must be complicated. A number of techniques for improving the durability of a recording medium have been disclosed. In Japanese Patent Laid-Open No. 53-24486, there is disclosed a technique for changing dye into color lake to fix by the postprocessing of dyed material in order to improve the dyed material durability against humidity. In Japanese Patent Laid-Open No. 54-43733, there is disclosed a method in which recording is performed by the ink-jet recording method using two or more components for increasing film-formation ability in touching mutually at normal temperature or when they are heated. This provides a print having a film strongly adhered to the recording medium when the components on the recording medium are caused to touch one another. In Japanese Patent Laid-Open No. 55-150396, there is disclosed a method for providing a waterproof agent for forming color lake after performing ink-jet recording with water-dye ink. In Japanese Patent Laid-Open No. 58-128862, there is disclosed an ink-jet recording method for recording by sequentially providing recording ink and processing liquid after recognizing in advance the position of an image to be recorded. According to the ink-jet recording method, recording is performed with the processing liquid after using the recording ink, the processing liquid being applied to the recording ink previously provided, or the recording ink being applied to the previously provided processing liquid before providing fresh processing liquid thereon. In the above Japanese Patent Applications there are not disclosed restoration means for maintaining discharging reliability, a head structure, a container structure, printing modes for improving a recording image quality, and so forth, which are characteristic in the ink-jet recording apparatus. In addition, images can be printed at high speed using a bi-directional printing method which scans by moving a carriage in two directions. Such bi-directional printing causes an image-quality difference due to the shift in the position of ink provided by bi-directional scanning, and a color difference due to the different order in which the several different color inks are applied. When a recording head for the processing liquid and a recording head for the ink are arranged in the main-scan direction, the order in which the processing liquid and the ink are provided is reversed from one direction of scan to the other. The processing liquid often causes the ink color to change. The ensuing color variation is readily seen when one compares the case where recording is performed by applying the processing liquid before the ink and the case where recording is performed by applying the ink before the processing liquid. For the foregoing reasons, when part of an image printed in one direction and an adjacent part of the image is printed in another direction, the color and image-quality difference between the adjacent parts appear strongly, which disadvantageously causes noticeable image-quality deterioration. According to Japanese Patent Laid-Open No. 2-233275, a break (blank image portion) in an image is detected so that a region to be printed in another direction is not adjacent to the break, which enables bi-directional printing. In this method the printing direction is not reversed unless the break is detected. Printing continues in the same direction as the previous printing direction until the break is detected. One example is shown in FIG. 10. Region a' is printed in the direction from left to right (the "forward" direction). Since a break is not detected between regions a' and b', region b' is printed in the same direction in which region a' was printed. A break exists between regions b' and c'. Thus, when region c' is printed, a carriage moves in the direction opposite to the direction in which the previous region was printed. In other words, region c' is printed in the direction running from right to left (the "backward" direction). Since a break is not detected between regions c' and d', region d' is printed in the same direction in which region c' was printed. The above method is effective in reducing the difference between the forward-printed color and the backward-printed color or a shift in the position of printed ink and performing the bi-directional printing. In addition, the present inventors have found that, when a combination of a material having an increased amount of a surface active agent and another material having a reduced amount of a surface active agent, or no surface active agent, is selected from combinations of ink and a print-characteristic improving liquid including a material for improving print characteristics (such as water resistance) of the ink when the ink is provided to a recording medium, an irregular image is generated at the region between scans due to the order of shooting the ink and the print-characteristic improving liquid. The phenomenon and the mechanism of this occurrence will be described below. The main cause of the irregular image at the region between the scans is a phenomenon in which the concentration of the ink has a distribution such as to form a whitish portion, which is hereinafter referred to as a "white blur" phenomenon. It is thought that the white blur phenomenon is caused by the surface active agent. FIGS. 8A to 8D illustrate the white blur phenomenon caused by the distribution of the ink concentration on an image border. FIG. 8A shows an example in which a liquid-A printing region and a liquid-B printing region are mutually in contact. Ink with a relatively high amount of surface active agent is used as liquid A, while ink with a reduced amount of the surface active agent is used as liquid B. As shown in FIG. 8A, the white blur phenomenon occurs in the liquid-A printing region. In general, adding a surface active agent reduces a liquid's surface tension and increases the liquid's permeability. Ink having high surface tension and low permeability is unlikely to produce the phenomenon of "feathering" in which ink expands along fibers of paper, which means the border between printed part and non-printed part will be clear. Accordingly, ink having low permeability is frequently used as black ink for printing characters. In contrast, ink to which increased amounts of surface active agent have been added has low surface tension and high permeability. Such ink is likely to cause feathering but quickly permeates the recording medium. Thus, this ink causes little ink mixing (called "bleeding") at the contact border between different colors, and is preferably fixative. This type of ink is frequently used as an ink having a color other than black. In many cases, liquid having high permeability is used as the print-characteristic improving liquid in consideration of fixation improvement, discharge characteristics, and so forth. FIGS. 8B to 8D show the mechanism by which white blur is thought to occur. As shown in FIG. 8C, when liquid (ink) A having low permeability contacts liquid (ink) B having low permeability, the liquids having been applied to a recording medium as shown in FIG. 8B, a surface active agent included in liquid B reaches the edge of liquid A which in contact with liquid B. As a result, liquid A has a region (region 11) where an increased amount of surface active agent is added and there is also a region (region 12) where the amount of surface active agent is reduced. The influence of the inflowing surface active agent causes liquid A, which originally had high surface tension and low permeability, to have low surface tension and high permeability. The high surface tension-portion (region 11) in liquid A concentrates at the center of the liquid-A drop due to the high surface tension itself. Accordingly, the concentration of liquid A has a distribution. Region 11 has a high concentration, while region 12 has a low concentration. The influence of the surface active agent causes liquid A in region 12 to quickly permeate the recording medium, with the low concentration of region 12 being unchanged. As a result, coloring material in the liquid A hardly remains on the surface of the recording medium, and the surface looks whitish, as shown in FIG. 8D. The white blur occurs not only in the contact border in the main-scan direction in which a recording head and a recording medium are relatively moved in a recording mode but also between different rows in the sub-scan direction in which the recording head and the recording medium are relatively moved in a non-recording mode. In addition, the occurrence of the white blur is not limited to the case that the liquid-B printing region is formed with only a single liquid. For example, the white blur occurs also when a liquid with a surface active agent and a liquid without a surface active agent are simultaneously put on the liquid-B printing region. FIGS. 9A to 9E show the occurrence of white blur when black ink (liquid-A type without a surface active agent) and a print-characteristic improving liquid (liquid-B type with a surface active agent) are simultaneously applied. FIG. 9A schematically shows a monochrome-printing recording head provided with a print-characteristic-improving-liquid (S) discharge outlet represented by diagonal lines and a black ink (Bk) discharge outlet represented by black. The recording head moves on a recording medium in the directions denoted by arrows so that an image is recorded on the recording medium. FIG. 9B shows a case in which the recording head shown in FIG. 9A performs recording for two rows by moving from right to left on a print region. In this case, a black record image and a print-characteristic-improving-liquid record image overlap. In other words, the print-characteristic improving liquid is ejected after the ink has been ejected. When recording with the print-characteristic improving liquid is performed after performing recording with the ink, white blur is generated on the border between the print regions as shown in FIG. 9B. Region 21 is an area formed by the previous scan, in which the ink and the print-characteristic improving liquid mix, and the effect of the print-characteristic improving liquid causes coloring material in the ink to be insoluble or aggregate. Since the print-characteristic improving liquid has been applied in region 21, its surface active agent exists. With the recording head moving from right to left, the ink is initially ejected onto the recording medium, and after a lapse of a predetermined time determined by the head width and the moving speed of a carriage, the print-characteristic improving liquid is ejected to form an area where the black ink and the print-characteristic improving liquid mix. Region 22 is a region where nothing is printed. Region 23 is a print region where only the ink is used. Regions 24 is a print region where both the print-characteristic improving liquid and the ink are used, similar to region 21. FIG. 9D schematically shows a condition just before the white blur seen in FIG. 9B occurs, namely, the same condition as shown in FIG. 8B in the section taken on line 9D--9D shown in FIG. 9B. Region 21 has a large part of the surface active agent included in the print-characteristic improving liquid. Since only the black ink forms region 23, no surface active agent is included in region 23. Region 21 and region 23 come into contact, and the surface active agent in region 21 moves to region 23. Consequently, the distribution (white blur) of the ink concentration is generated on the edge of region 23 as shown in FIG. 9B. In other words, the section shown in FIG. 9D changes consequently to the condition shown in FIG. 8C. After white blur is generated in black ink in a region, even if a print-characteristic improving liquid is ejected in the region, the white blur cannot be improved. Instead, the effect of the print-characteristic improving liquid causes coloring material to be insoluble or aggregate, with the distribution of the ink concentration unchanged. FIG. 9C shows the reverse of the case shown in FIG. 9B in which the recording head shown in FIG. 9A performs recording for two rows by moving from left to right. In this case a black record image and a print-characteristic-improvement-liquid record image overlap. In other words, the print-characteristic improving liquid is ejected before the ink. When recording with the print-characteristic improving liquid is performed before performing recording with the ink, white blur as shown in FIG. 9B is not generated on the border between the print regions. Region 25 shown in FIG. 9C is an area formed by the previous scan, in which the ink and the print-characteristic improving liquid mix. Since the print-characteristic improving liquid is included in region 25, its surface active agent is also included. With the motion of the recording head from left to right, the print-characteristic improving liquid is initially ejected, and after a lapse of a predetermined time, the black ink is ejected to form a region where the black ink and the print-characteristic improving liquid mix. Region 26 is, similar to region 25, a print region in which both the print-characteristic improving liquid and the ink are used. Region 27 is a print region where only the print-characteristic improving liquid is used. Region 28 has no recording. FIG. 9E schematically shows the section taken on line 9E--9E shown in FIG. 9C. The print-characteristic improvement liquids have been ejected in both regions 25 and 27. Thus, surface active agents are present in regions 25 and 27. The black ink is applied in the print region (region 27) where only the print-characteristic improving liquid is used. However, unlike the case shown in FIG. 9B, when the black ink reaches the recording medium, the print-characteristic improving liquid has been already applied. Accordingly, the concentration of the surface active agent has no distribution, and when the ink comes into contact with the print-characteristic improving liquid, the coloring material becomes insoluble or aggregates quickly, so that white blur cannot occur. The foregoing cases have been described in connection with monochrome printing. However, a similar phenomenon also occurs when color ink not having a surface active agent is selected. As described above, the present inventors have found that, when ink is ejected before ejecting a print-characteristic improving liquid, the image quality of a border in contact with a region including the print-characteristic improving liquid may deteriorate remarkably in the main-scan direction and the sub-scan direction. SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing problems. Accordingly, it is an object of the present invention to provide an ink-jet recording apparatus and method which detect a blank (break) of an image and enable forward printing only when detecting blanks at the top and bottom ends of a region capable of being printed by one scan, whereby the ink-jet recording apparatus and method prevent irregular images caused by consecutive rows printed by the forward printing, and execute forward and backward printing while reducing the color difference between the printing directions so that high-quality output can be obtained at high speed. One aspect of this invention pertains to an ink-jet recording method for recording an image by applying ink and print-characteristic improving liquid for improving a print-characteristic of the ink to a recording medium. The ink and print-characteristic improving liquid are applied to the recording medium at a single identical region on the recording medium. This method divides a recording range into regions before either a first step of applying the print-characteristic improving liquid and then the ink to each divided region, in that order, or a second step of applying the ink and then the print-characteristic improving liquid, in that order, determining if an image which is continuous over adjacent regions exists on a border between the adjacent regions. The second step is used to make one region to be used for recording recordable when it is determined in the determining step that the continuous image does not exist on the border between the one region without recording and the one region with recording performed, and that the continuous image does not exist on the border between the one region without recording and the one region to be used for the subsequent recording. This invention also concerns an ink-jet recording apparatus for recording an image by applying ink and print-characteristic improving liquid for improving a print-characteristic of the ink to a recording medium. The ink and print-characteristic improving liquid are applied to the recording medium at a single identical region on the recording medium by discharging the ink and print-characteristic improving liquid from a recording head. Recording is performed by dividing a recording range into plural regions before either a first step of applying the print-characteristic improving liquid and then the ink to each divided region, in that order, or a second step of applying the ink and then the print-characteristic improving liquid, in that order. The ink-jet recording apparatus has a determination means for determining if an image which is continuous over adjacent regions exists on a border between the adjacent regions, and a recording control means. The recording control means uses the second step to make one region to be used for recording recordable when it is determined by the determination means that the continuous image does not exist on the border between the one region without recording and the one region with recording performed, and that the continuous image does not exit on the border between the one region without recording and one region to be used for the subsequent recording. The print-characteristic improving liquid consists of liquids including a material which enables the ink to provide preferable characteristics such as water resistance when the print-characteristic improving liquid is provided on the recording medium together with the ink. The liquids include a liquid which, when it contacts the ink, causes the ink to act so that coloring material in the ink becomes insoluble or aggregate, a liquid causing the coloring material in the ink to be insoluble, and a liquid for dispersing coloring material in the ink to break. Causing the coloring material in the ink to be insoluble is, for example, a phenomenon in which anion groups included in a dye in the ink and the cation groups of cationic material included in the print-characteristic improving liquid react mutually as ions to form ionic bonds, and the ionic bonds cause the dye uniformly dissolved in the ink to separate from the solution. The term "aggregate" means "causing the coloring material in the ink to be insoluble" when the coloring material used in the ink is a water soluble dye having anion groups. When the coloring material used in the ink is a pigment, the term "aggregate" means that a pigment dispersion agent or the surface of the pigment and the cation groups of the cationic material included in the print-characteristic improving liquid react mutually as ions to disperse the pigment to break, and the diameter of each pigment particle is extremely enlarged. Normally, in accordance with the above-described aggregation, the viscosity of the ink increases. The above-described invention prevents image deterioration due to the distribution of ink concentration on the border between a region printed in one scan and another printing region, and executes bi-directional printing while reducing the color difference between printing directions, so that a high-quality output can be obtained at high speed. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart showing a process for determining the printing direction, according to an embodiment of the present invention. FIGS. 2A and 2B are charts illustrating the relationship between image data and the printing direction in an embodiment of the present invention. FIG. 3 is a block diagram showing a method for managing print data, according to an embodiment of the present invention. FIG. 4 is a flowchart showing a detailed process for performing a one-page printing operation, according to an embodiment of the present invention. FIG. 5 is a perspective view showing an ink-jet recording apparatus according to an embodiment of the present invention. FIG. 6A is a perspective view showing a recording head unit according to the present invention. FIGS. 6B to 6E are plan views showing discharge-outlet surfaces for a recording head according to the present invention. FIG. 7 is a block diagram showing a recording apparatus according to an embodiment of the present invention. FIGS. 8A to 8D are charts illustrating white blur generated in an image border. FIGS. 9A to 9E are charts illustrating the relationship between the occurrence of white blur and a printing direction. FIG. 10 is a chart illustrating one example of the relationship between image data and a printing direction when bi-directional printing is performed by a conventional recording method. FIG. 11 is a block diagram showing a case in which a recording apparatus according to the present invention serves as a recording means for an information processing system having word-processor, personal computer, facsimile and photocopier functions. FIG. 12 is a perspective view showing the exterior of the information processing system shown in FIG. 11. FIG. 13 is a perspective view showing one example in which a recording apparatus of the present invention serves as a recording means for an information processing system. DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings. The direction in which printing with a printing-characteristic improving liquid is performed before printing with ink is hereinafter referred to as the "forward direction". The reverse direction in which printing with the printing-characteristic improving liquid is performed after printing with the ink is hereinafter referred to as the "backward direction". And, the direction in which either the forward or the backward direction is arbitrarily selected for printing is hereinafter referred to as the "arbitrary direction". Also, the scan operation in which printing is about to start is hereinafter referred to as "the present scan". Scanning in which printing was performed just before the present scan is hereinafter referred to as "the previous scan". And, the scan operation in which printing will start just after the present scan is hereinafter referred to as "the subsequent scan". In addition, a region having no image data is hereinafter referred to as a "break". FIG. 1 shows a flowchart illustrating a process for determining the printing direction. In determination step S1, the process determines whether or not a break exists between the previous scan and the present scan. If the break exists, the process proceeds to the next determination step S2. If the break does not exist, the printing direction in the present scan is determined to be the forward direction. In determination step S2, the process determines whether or not a break is included in a break determination region with the present scan performed. Depending on the type of image data, there is a case where the whole of a region capable of being printed by one scan is not printed, but the forward and backward printing improves the throughput even if the printable region with one scan is reduced. Accordingly, the break determination region for determining the presence or absence of the break is provided in the present scan. If the break is included in the break determination region, the process proceeds to step S5, in which the image data up to the detected break is recorded in the arbitrary direction. The arbitrary direction is selected so that recording by the present scan can be performed in the shortest time. In an ink-jet recording apparatus, not only a scanning operation for normal recording but also a preliminary discharging operation for discharging ink outside a printing region and a suction-restoration operation for sucking and evacuating the ink from a discharging outlet are performed in order to improve the reliability of recording. In many cases, the positions of units for performing the operations are fixed, while a carriage moves. When the carriage does not move in order to perform the preliminary discharging operation and the suction-restoration operation, the direction in which the present-scan printing can be performed in the shortest time is the reverse direction with respect to the printing direction in the previous scan. When the carriage moves between the previous scan and the present scan, the same direction as in the previous scan may be the direction in which recording can be performed in the shortest time. In determination step S2, if the process has determined that the break is not included in the break determination region in the present scan, the process proceeds to determination step S3, where a determination of whether or not a break is found at the start of the subsequent scan is made. If a break is found, the process proceeds to step S5, in which recording is performed in the arbitrary direction. If a break is not found, the process proceeds to step S4, in which recording is performed in the forward direction. A process for detecting the break will be described below. FIGS. 2A and 2B show examples of printing. Regions a to h are areas where printing is performed by scanning one time with a recording head in the main-scan direction. Tables in FIGS. 2A and 2B show whether the break is present or missing between the present scan and the previous scan or the subsequent scan in regions a to h. Image data as shown in FIG. 2A are all recorded in the forward direction. Since there is no break at the connection between regions a and b, regions a and b are recorded in the forward direction. There is a break at the connection between regions b and c, but there is no break at the connection between regions c and d. Thus, both regions c and d are recorded in the forward direction. Image data as shown in FIG. 2B are partly recorded in the arbitrary direction. Since there is no break at the connection between regions e and f, regions e and f are recorded in the forward direction. There is a break at the connection between regions f and g, and there is a break at the connection between regions g and h. Thus, region g is recorded in the arbitrary direction. There is no break at the connection between region h and the subsequent region to be scanned. Thus, region h is recorded in the forward direction. Next, specific examples of a data management method and a data processing method for performing the printing operation will be described below. FIG. 3 shows a block diagram illustrating a method for managing print data according to the embodiment of the present invention. A printable range for one scan by the printing head is managed by being divided into blocks #1 to #N, and the printing data corresponding to the respective blocks are separately stored in a printing buffer memory 2. The printing data stored in the printing buffer memory 2 is sent to a printing head 1 via a data-transfer control circuit 3. The data-transfer control circuit 3 can control the data output to the printing head 1 block by block, and can selectively determine whether or not to record each block. In this embodiment, by referring to the data stored in the printing buffer memory 2 corresponding to each block, the data-transfer control circuit 3 determines whether or not printing data for each scan is successive, and uses the result to control the printing direction. When the printing data is not successive, there is a break, namely, a blank in an image. The simplest way to detect whether or not there is a break between the printing region with the present scan and the printing region with the subsequent scan is to detect whether or not printing data is included in block #N as the end block of the printing data of N blocks capable of being printed by the present scan and block #N+1 as the subsequent block. However, if a break is detected and the forward direction printing can be performed, N blocks capable of being printed by the present scan are not all printed. Instead, the printing time can be shortened by printing the upper blocks rather than the break-detected block by the present scan, and printing the lower blocks and the break-detected block by the subsequent scan. For example, when blocks #N to #N+1 have printing data, printing all blocks #N to #N+1 by the present scan hinders the printing regions with the present scan and the subsequent scan from separating. However, for example, when block #N-1 has no printing data, by printing block #N-1 by the subsequent scan without printing block #N-1 by the present scan, the printing regions with the present scan and the subsequent scan can be separated. According to this embodiment, M blocks from the bottom among N blocks capable of being printed are used as a range from which a break is detected. In a case where there is block #X having no printing data in blocks #N-(M-1) to #N+1, only blocks #1 to #X-1 are printed with the present scan by setting the data-transfer control circuit 3, and the printing regions with the present scan and the subsequent scan are separated by printing the blocks after block #x+1 in the subsequent scan. Thereby, the forward printing can be performed to shorten the printing time. Here the region of M blocks from the bottom where a break is detected corresponds to "the break determination region" appearing in the above-described step S2 shown in FIG. 1. FIG. 4 shows a flowchart of a detailed process for performing one-page printing operation. In step S11, before the one-page printing operation, both a previous-scan continuation flag and a subsequent-scan continuation flag in a work memory are set to be false. The previous-scan continuation flag represents whether or not the printing data is continuous in the printing region with the present scan performed and the printing data in the printing region with the previous scan performed. The subsequent-scan continuation flag represents whether or not the printing data is continuous over the printing region with the present scan performed and the printing data in the subsequent scan performed. In step S12, when the printing by one scanning starts, a paper feeding operation is executed so that the start of data which has not been printed comes at the position of block #1. In step S13, by referring to the printing data stored in the printing buffer from the bottom block #N+1 to the upper blocks, the process detects whether or not there is a block having no printing data among blocks #N+1 to #N-(M-1). In step S14, if the block having no printing data is not detected, a condition is found in which the printing data in the present scan and the subsequent scan is continuous. Accordingly, in this case, in step S15, the subsequent-scan continuation flag is set to be true, and in step S16, N representing the bottom block of the printing head is substituted in the place of variable X representing the bottom block to be printed by the present scan. If, however, in step S14, if the block having no printing data is detected, the printing data in the present scan and the subsequent scan can be separated with the data block as a boundary. In this case, in step S17, the subsequent-scan continuation flag is set to be false. In step S18, a number obtained by subtracting one from the number of the block having no recording data, initially detected in step S13, is substituted in the place of variable X representing the bottom block to be printed by the present scan. In the above manner, detection of whether the present scan and the subsequent scan are continuous or there is a break between them is performed, and the result determines the value of the subsequent-scan continuation flag. In addition, the previous-scan continuation flag has been determined to represent whether or not the present scan and the previous scan are continuous. Thus, in step S19, by verifying whether or not both the previous scan flag and the subsequent scan flag are false, the process can determine whether or not the present scan is independent from the previous scan and the subsequent scan. In step S20, if both the previous scan flag and the subsequent scan flag are false, the present scan is independent from the previous scan and the subsequent scan. Thus, blocks #1 to #X are printed in the arbitrary direction. In addition, in step S19, if either the previous-scan continuation flag or the subsequent scan continuation flag is true or both flags are true, printing in the arbitrary direction cannot be performed. Thus, in step S21, blocks #1 to #X are printed in the forward direction. After printing by scanning one time, the subsequent-scan continuation flag can be used as the previous-scan continuation flag in the printing operation by the subsequent scan. Thus, in step S22, the previous-scan continuation flag is updated with the subsequent-scan continuation flag. By repeating steps S12 to S22 a required number of times for scanning until the answer to determination in step S23 is yes, recording for one page is completed. It will be appreciated that those skilled in the art of computer programming, especially computer programming of the type now used to control ink jet printers, would, in view of the foregoing flowcharts and discussion, be able to implement this recording method. That is, and ink jet printer controller could be suitably programmed using known techniques to implement the recording method of this invention, in view of this disclosure. FIG. 5 shows an ink-jet recording apparatus according to an embodiment of the present invention. In the ink-jet recording apparatus 100, a recording medium 106 inserted at a feeding position 111 is fed by a feeding roller 109 to the recording region of a recording head unit 103. Platen 108 is provided beneath the recording medium in the recording region. A carriage 101 provided so as to move in the direction determined by two guide shafts 104 and 105 scans the recording region back and forth. The carriage 101 is provided with recording heads for discharging a plurality of color inks and print-characteristic improving liquid (S), and the recording head unit 103 including an ink tank for supplying the recording heads with the inks and the print-characteristic improving liquid (S). The ink-jet recording apparatus according to this embodiment uses the following four color inks: black (Bk), cyan (C), magenta (M) and yellow (Y). There is a restoration system unit 110 at the lower left-end of the region in which the carriage 101 can move. When recording is not performed, the restoration system unit 110 positioned at the lower left end of the region in which the carriage 101 caps the discharge outlet of the recording head, and so forth. The left end is called the "recording-head home position". Switching/display units 107 consist of a switching unit used to switch the main power of the recording apparatus 100, and a switching unit for displaying the condition of the recording apparatus 100. FIG. 6A shows a perspective view of the recording head unit 103, in which all the containers for the inks Bk, C, M and Y, and the print-characteristic improving liquid S are independently replaceable. The carriage 101 is provided with recording heads 102, the Bk container 20K, the C container 20C, the M container 20M, the Y container 20Y, and the print-characteristic-improving-liquid container 21. The containers 20K, 20C, 20M, 20Y and 21 are connected to the recording heads, and their outlets are supplied with the inks and the print-characteristic improving liquid. Alternatively, the print-characteristic-improving-liquid container 21 and the Bk container 20K may be incorporated as a single structure. FIG. 6B shows the discharge-outlet surface (opposed to the recording medium) of the recording heads 12. Recording heads 30K, 30C, 30M and 30Y respectively discharge Bk, Ck, M and Y inks, and a head 31 discharges the print-characteristic improving liquid. In addition, according to the present invention, a head 32 incorporating the C, M and Y heads as shown in FIG. 6C, or a head 33 formed by incorporating the Bk, C, M and Y heads as shown in FIG. 6D may be used. Alternatively, a monochrome head 30K as shown in FIG. 6E may be used. In any of the head structures the recording-ink discharge heads and the print-characteristic-improving-liquid discharge head are arranged in parallel in the main-scan direction. The heads may be incorporated by combining single heads, or one head may be provided with a plurality of discharge outlets for inks. FIG. 7 shows a block diagram of the ink-jet recording apparatus 100 according to the embodiment of the present invention. Image data to be recorded is input from a host computer to a receiving buffer 401 in the ink-jet recording apparatus 100. Data enabling confirmation of whether or not the image data is normally transferred, and data for notification of the operating condition of the recording apparatus 100 are output to the host computer. The image data stored in the receiving buffer 401 is transferred to a memory unit 403 under control of a controller 402 including a central processing unit (not shown), and is temporarily stored in the random access memory (not shown) of the memory unit 403. In accordance with a command from the controller 402, a mechanism controller 404 drives a mechanical unit 405 such as a carriage motor or a line-field motor. A sensor/switch (SW) controller 406 sends a signal from a sensor/SW unit 407 to the controller 402. A display device controller 408 controls a display device including light emitting diodes and a liquid-crystal display device of display panels in accordance with a command from the controller 402. A (recording) head controller 410 controls (recording) heads 411 in accordance with a command from the controller 402, and transmit information such as temperature information representing the condition of the heads 411, to the controller 402. Ink-jet recording methods applicable to the present invention include a method in which devices (e.g., electric heat converter, and a laser) for generating heat energy as energy used to discharge ink are used, and a change in the condition of the ink is caused by the heat energy. The method can achieve high-density, highly-detailed recording. For example, the basic principles disclosed in U.S. Pat. Nos. 4,723,129 and 4,740,796 are preferably used as the typical structure and principle of the above-mentioned method. The above-mentioned method can be applied to either a on-demand type or continuous type recording device. In particular, in the case of the on-demand type device, by applying at least one driving signal, corresponding to recording information, for providing a rapid temperature rise exceeding film boiling, to an electric heat converter disposed to correspond to a liquid (ink)-held sheet or liquid path, heat energy can be generated in the electric heat converter, and film boiling can be generated on a surface on which the recording head heat acts. This is effective because a bubble in the liquid (ink) corresponding to the applied signal can be formed. By using the growth and contraction of the bubble to discharge the liquid (ink) via the discharge opening, at least one drop is formed. If the driving signal is in the form of pulses, the bubble can be instantaneously and properly grown and contracted. This enables liquid (ink) to be discharged in a highly responsive manner, which, it will be understood, is quite desirable. Concerning the pulse-form driving signal, signals such as those described in U.S. Pat. Nos. 4,463,359 and 4,345,262 are proper. In addition, by employing conditions like those described in U.S. Pat. No. 4,313,124 with regard to the temperature rise rate on a surface on which recording heat acts, more superior recording can be performed. Concerning the structure of the head 411 used with this invention, not only a combination (linear liquid path or perpendicular liquid path) of the structures of a discharge outlet, a liquid path and an electric converter as disclosed in each of the above United States patents but also structures disclosed in U.S. Pat. Nos. 4,558,333 and 4,459,600 on the arrangement of a heat-acted surface in a bending region are suitable. In addition, the present invention may be constructed in the manner of Japanese Patent Laid-Open No. 59-123670 disclosing a structure in which slots common to a plurality of electric heat converters are used as the discharge outlets of the electric heat converters, and Japanese Patent Laid-Open No. 59-38461 disclosing a structure in which an opening for absorbing electric-heat pressure waves is correlated with a discharge outlet. In addition, an exchangeable chip-type recording head which can be electrically connected to the recording-apparatus body and which can be supplied with ink from the recording-apparatus body when the recording head is mounted upon the recording-apparatus body, or a cartridge-type recording head with an ink container incorporated therein may be used. Moreover, the mode of the recording apparatus of the present invention may be one used as the image output terminal of an information processing apparatus like a computer, a photocopier combined with a word processor, a reader and so forth, and the recording means of a facsimile apparatus having transmission and receiving functions. FIG. 11 is a block diagram of showing information processing apparatus having functions as a word processor, a personal computer, a facsimile apparatus and a photocopier, in which the recording apparatus of the present invention is used. A controller 1801 including a central processing unit (CPU) and various types of input/output ports controls other units by outputting control signals and data signals to the other units, and receiving control signals and data signals input from the other units. A display 1802 projects various menus, document information and image data read with an image reader 1807 on its display screen. A transparent pressure-sensitive touch panel 1803 is mounted on the display 1802. By pressing the surface of the touch panel 1803, items and coordinate positions can be input on the display 1802. A frequency modulation (FM) sound unit 1804 stores music information made with a music editor in a memory 1810 or an external storage unit 1812, and reads the stored information from them in order to perform the frequency modulation of it. An electric signal from the FM sound unit 1804 is converted to audio sound by a speaker 1805. A printer 1806 is an output terminal as recording means for word processor, personal computer, facsimile and photocopier functions, to which the recording apparatus of the present invention is applied. The image reader 1807 is provided in the middle of a carrier path, for input by photoelectrically reading subject-copy data, and reads various types of subject copies such as a facsimile subject copy and a reproduction original copy. A facsimile (FAX) trans-receiver 1808 having an interface function with the exterior performs the facsimile transmission of the subject copy read by the image reader 1807, and receives and decodes transmitted facsimile signals. A telephone unit 1809 has various types of functions such as an ordinary telephone function and an automatic answering function. The memory 1810 includes a read-only memory (ROM) holding a system program, a manager program, applications, character fonts, dictionaries, and so forth, and a random access memory (RAM) holding applications, document information and video information, loaded from the external storage unit 1812. A key board 1811 is used to input document information, various commands, and so forth. The external storage unit 1812 uses a floppy disc or hard disc as a storage medium. Information such as document information, music or sound information, and/or the user's applications are stored in the external storage unit 1812. FIG. 12 shows the schematic exterior of the information processing apparatus shown in FIG. 11. On a flat-panel display 1901 using liquid crystal or the like, various menus, figure information, document information and so forth are projected. The touch panel 1803 shown in FIG. 11 is mounted on the display 1901. By pressing the surface of the touch panel 1803, coordinates and items can be input. A handset 1902 is provided so that a telephone function can be used. A key board 1903 is connected to the main body by a cord so as to be taken off from the main body, and enables inputting various document information and various data. The key board 1903 is provided with various function keys 1904. An insertion opening 1905 allows a floppy disc, which is a form of external storage unit 1812 shown in FIG. 11, to be used. A subject-copy holder 1906 is used to hold a subject copy to be read by the image reader 1807. The read subject copy is ejected from the back of the information processing apparatus. When facsimile transmission is received, an ink-jet printer 1907 prints the transmitted image. The display 1802 may comprise a cathode-ray tube. However, it is preferable to use a flat-panel type such as a liquid crystal display using ferroelectric liquid crystals because it enables not only size reduction and thickness reduction but also weight reduction. When the information processing apparatus functions as a personal computer or word processor, various information input from the key board 1811 is processed in accordance with predetermined programs by the controller 1801, and the processed information is output as an image by the printer 1806. When the information processing apparatus functions as a facsimile receiver, facsimile information input from the FAX trans-receiver 1808 via a communication line is processed for receiving in accordance with predetermined programs by the controller 1801, and the processed information is output as a received image by the printer 1806. When the information processing apparatus functions as a photocopier, the subject copy is read by the image reader 1807, and the read subject copy is output as a copy image by the printer 1806 via the controller 1801. When the information processing apparatus functions as a facsimile transmitter, subject-copy data read by the image reader 1807 is processed for transmission in accordance with predetermined programs, and the processed data is transmitted to the communication line by the FAX trans-receiver 1808. As shown in FIG. 13, the above-described information processing apparatus may have a built-in structure in which the ink-jet printer is included in the information processing apparatus, which enhances portability. In FIG. 13, portions having functions identical to those shown in FIG. 12 are denoted by the corresponding reference numerals. As described above, by applying the ink-jet printer of the present invention to the multi-functional information processing apparatus, a high-quality printed image can be obtained at high speed, with low noise. Thus, the functions of the above-described information processing apparatus can be further improved. According to the present invention, the presence or absence of consecutive data selects the printing direction, which enables printing in two directions. Thus, a high-quality image can be obtained at high speed.

An ink-jet recording method and a recording apparatus used in the method detect a blank region of an image, and enable backward printing only when detecting those blanks at the top and bottom ends of a region where printing can be performed by one scan. The ink-jet recording method and the recording apparatus prevent irregular images, that would otherwise be caused by consecutive rows printed by the backward printing, and execute forward and backward printing while reducing the color difference between the printing directions so that a high-quality output can be obtained at high speed. As a result, when ink is ejected before the ejection of a print-characteristic improving liquid, the image quality of a border in contact with a region including the print-characteristic improving liquid in the main-scan direction and the sub-scan direction can be improved.

RELATED APPLICATION This application claims the benefit of the filing date under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 60/429,811, filed Nov. 27, 2002, the entire contents of which is incorporated herein by reference. BACKGROUND The present invention relates generally to a window assembly. More specifically, the invention relates to a window guard to protect an edge in an opening of a window. While the primary functional purpose of such a sliding window assembly in a vehicle is primarily intended for ventilation, it is not uncommon for users to take advantage of the window as a pass-thru opening for supporting lengthy cargo and thereby minimize rearward extension of the cargo outside the vehicle. The downward force exerted by resting such cargo on the exposed edge of the window opening should, in most cases, not be of major concern by itself, since the compressive strength of glass is generally quite good. However, lateral forces (fore & aft), abrasion, and/or impact forces resulting from such cargo resting on the glass could be of concern. From the above, it is seen that there exists a need for protection of certain exposed edges in a window opening. BRIEF SUMMARY OF THE INVENTION In overcoming the above mentioned and other drawbacks, the present invention provides a window assembly, such as the slider backlight assembly commonly found on pick-up truck vehicles, having a fixed window with an opening, a slidable panel that slides relative to the fixed window to cover or expose the opening in the fixed window, and a covering to protect the lower edge of the window opening. The covering may be a protective sheet attached at one end to a lower member or portion of the window assembly. The other end remains unattached so as to create a flexible flap of material. When needed, the protective cover is simply placed over the exposed bottom edge of the opening to protect the edge from damage by objects resting on the edge, and when not in use the cover is allowed to hang freely or otherwise fastened out of the way below the window opening. The protective material could be suitably colored and textured to coordinate with adjacent interior trim materials. The covering is a flexible, durable sheet. The fixed end of the covering may be attached to the interior or exterior of the fixed window with a suitable connection means. Various attachment means, both permanent and releasable, can be used to secure the cover in place. The cover may be a substantially U-shaped clip that covers the edge in a removable manner. Further features and advantages will become apparent from the detailed description and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, incorporated in and forming a part of the specification, illustrate several aspects of the present invention. The components in the figures are not necessarily to scale, emphasis instead being placed on illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the views. In the drawings: FIG. 1A is a back view of a sliding window assembly in an open position with a protective edge cover flap in accordance with an embodiment of the invention. FIG. 1B is a perspective view of a portion of the sliding window assembly. FIG. 2 is a perspective view of a portion of a sliding window assembly in an open position with a protective edge cover flap in accordance with another embodiment of the invention. DETAILED DESCRIPTION FIGS. 1A and 1B depict a sliding window assembly 10 with a fixed panel 12 and a slideable panel 14 . In one example, the panels 12 and 14 are both of glass and are used as part of the backlight assembly of a vehicle, e.g., a pickup truck. Alternatively, either panel 12 or 14 or both can be made from a plastic. In operation, the slideable panel 14 slides back and forth relative to the fixed panel 12 along a pair of rails 13 so that a user, such as the driver or passenger, can move the panel 14 between an open position and a closed position. In accordance with an embodiment of the invention, the window assembly 10 is also equipped with a protective edge cover 16 placed over an otherwise exposed edge 18 of an opening 20 in the fixed panel 12 . The edge cover 16 can be a detachable. In the embodiment illustrated in FIGS. 1A and 1B , the edge cover 16 is a “U”-shaped clip of rubber (or some other suitable durable material) that fits snugly over the edge 18 . Thus, the U-shaped cover 16 can simply be inserted over the edge 18 of the panel 12 , and thereby isolate or insulate the exposed edge 18 of the panel 12 from direct contact with cargo that might come to rest on the edge of the glass when the sliding panel 14 is in the open position. When the protective function of the cover 16 is not desired, the user removes the cover 16 by simply pulling the cover 16 away from the edge 18 , and the user can then move the sliding panel 14 to the closed position and lock the sliding panel in place with a pair of latches 15 that mate with a pair of attachments mechanisms 17 on the panel 12 . In its closed position, the slideable panel 14 covers the opening 20 in the fixed panel 12 . In its open position, the slideable panel is moved to the side to uncover the opening 20 . A user may then place cargo in the bed of the truck such that the cargo extends through the opening 20 into the cab of the truck and rests on top of the cover 16 . As mentioned above, the cover 16 functions as a protective cover for the lower edge 18 of the opening 20 . Accordingly, the edge 18 is protected from impact forces and abrasion from the cargo extending through the opening 20 . Thus, the user can place cargo on the edge 18 , for example, the lower edge of an opening in a sliding glass backlight assembly of a pickup truck, without concern for damaging the panel 12 . Referring now to FIG. 2 , the cover 16 can be a protective sheet integrated into the design of the window assembly 10 . In this configuration, the cover 16 cannot become separated and lost or displaced. The cover 16 can be equipped with attachment features, for example, protrusions or snaps, which mate with attachment features formed on the fixed panel 12 or on the support structure in which the fixed panel 12 is mounted. The attachment features of the cover 16 are releasable from those on the fixed panel 12 or the nearby support structure of the cab in which the fixed panel is mounted. The attachment features can be configured for attaching the cover 16 either to the inside or outside of the fixed panel 20 or to both sides. In one implementation, the cover 16 has one end 22 coupled, for example, to the fixed panel 12 or the support structure for the fixed panel 12 by a hinge, adhesive, screw, or other suitable fastening mechanism 23 . The other end 24 of the cover 16 is equipped with a releasable fastening feature 26 , for example, a snap, hook and loop fastener, latch, or VELCRO and the panel 12 or support structure is equipped with a corresponding fastener feature 28 located on the opposite side of the panel 12 from the fastening mechanism 23 . The fastener feature 28 mates with the fastening feature 26 in a releasable manner. To use the cover 16 , the user pulls the end 24 of the cover 16 and extends it through the opening 20 to cover the edge 18 . The user then secures the fastening features 26 with the respective fastening features 28 to hold the cover 16 in place. The implementation shown in FIG. 2 can be configured with the fixed end 22 coupled either to the outside or inside of the panel 12 . Thus, in certain arrangements, the protective edge cover flap 16 can be pulled from outside the cab, and in other arrangements, the cover 16 is pushed from inside the cab through the opening 20 . While the above description contains specificities, these should not be construed as limitations on the scope of the invention, but merely as examples of the presently preferred embodiments. Other variations are possible within the teachings of the invention. For example, the protective material of the cover 16 can be made from polyurethane, or polyvinyl and KEVLAR, or any other suitable abrasion resistant material. The cover 16 can have any suitable thickness that isolates impact forces from being imparted on the bottom edge of the panel by the cargo. Moreover, the protective material can be suitably colored and textured to coordinate with passenger compartment trim materials.

The present invention provides a window assembly having a fixed window with an opening, a slidable panel that slides relative to the fixed window to cover or expose the opening in the fixed window, and a covering to protect the lower edge of the window opening.

BACKGROUND OF THE INVENTION The present invention concerns a web dryer operating according to the air floating principle, comprising a plurality of nozzle members by which air, or an equivalent gaseous fluid, is blown into contiguity with the web that has to be dried, and which is at the same time supported without mechanical contact, and said nozzle members having a supporting surface producing said supporting effect. Means which are based on the blowing of gas and operate according to the air float principle are employed on paper manufacturing and processing machines for contactless cleaning, drying and stabilizing of the web. In the operations mentioned, the gas is introduced with the aid of various nozzle means on one or both sides of the web under treatment, the gas being thereafter drawn off before the next nozzle for reuse. The dryers known in prior art for contactless treatment of the web (float dryers) are composed of a plurality of nozzles from which are directed against the web a gas flow supporting and drying the web. The nozzles of the prior art used in said dryers can be divided into two groups: overpressure nozzles and nozzles with subatmospheric pressure. The operation of the former type is based on the so-called air cushion principle, wherein the air jet causes a static overpressure in the space between the nozzle and the web. The group of subatmospheric pressure nozzles includes the so-called airfoil nozzles, which attract the web and stabilize the running of the web. The attraction acting on the web is well known to derive from a flow field of the gas parallelling the web, causing a static under-pressure between the web and the supporting surface of the nozzle, or the so-called carrying surface. It is frequent that the so-called Coanda phenomenon is employed in overpressure as well as subatmospheric pressure nozzles to guide the air in desired direction. The overpressure nozzles in float dryers of the prior art direct sharp air jets substantially against the web. Such a localized impingement of the air jet on the web significantly enhances the heat transfer at the point where the jet and the web meet, thus giving rise to non-uniform distribution of the heat transfer coefficient in the longitudinal direction of the web, and this may cause quality defects in the web that is being treated. A further detriment when overpressure nozzles are being used is that because of the over-pressure feature they may not be used in one-sided treatment of the web. Regarding the patent literature associated with the present invention, reference is made to the following patents: U.S. Pat. No. 3,711,960, Finnish Pat. No. 42 522 and German publicizing print No. 2 020 430. The design of the dryers known through the said U.S. Pat. No. 3,711,960 and the German publicizing print No. 2 020 430 and of their subatmospheric pressure nozzles, is characterized by the feature that the nozzle slit opening on the side of the entry margin of the nozzle's carrying surface is extended onto a curved flow guiding surface connecting to the front margin of the carrying surface, so that the flow can be made to follow the carrying surface. These dryers of the prior art present the drawback that the blowing action parallel to the web tends to eject drying gas that has already been cooled in the preceding suction space, thereby lowering the differential temperature between the web and the drying gas and as a consequence reducing the heat transfer capacity. In dryers known in the art, the distance of the web from the carrying surface will be quite small (2-3 mm), which imposes high requirements on the smoothness and straightness of the drying surface (the carrying surface). This implies major requirements to be imposed on the design in the manufacturing of great width (over 3 m) dryers spanning the whole web. Through the above-mentioned Finnish Pat. No. 42 522 a dryer is known by the nozzles of which the air is blown on one side of the web in the form of jets parallelling it and which in the breadth direction of the web give rise to discontinuities, for which reason a non-uniform heat transfer capacity is experienced. For the same reason the web stability is also poor, and this dryer cannot be used to handle thin webs, owing to the fluttering which is produced in their case. It is also impossible in this nozzle to employ high blowing rates, and the nozzle is not usable in two-sided web treatment. In connection with modern, high output paper manufacturing and conversion machines the dryers considered will be bulky, space-consuming and expensive. Owing to the low stabilizing power of the carrying surface in dryers of prior art, it is further noted that the one-sided treatment of heavy material webs has previously only been possible in the horizontal plane, with blowing from underneath the web. This fact has tended to restrict the designing of the dryer and to increase the apparatus size. SUMMARY OF THE INVENTION The object of the present invention is to avoid the drawbacks mentioned and to create a dryer wherein it is possible to improve considerably the evaporating and stabilizing capacity from what they have been in prior art. It is further an object of the invention to produce a dryer of the type in question which has a specific energy consumption considerably lower than those of prior art. In order to achieve the objects mentioned, the invention is mainly characterized in that the carrying surface of the dryer is defined by a plurality of separate nozzle members disposed in the direction of travel of the web after each other and side by side and which present a substantially annular nozzle slit, and a carrying surface associated with the nozzle members into contiguity with which the drying gas is conducted in a substantially radial flow field in directions substantially parallel to the web. The higher than previous specific evaporating capacity of the dryer fulfilling the criteria mentioned is mainly based on the higher heat transfer coefficient between the web and the drying gas achieved with its aid. Three partial factors contributing to an improved heat transfer factor may be mentioned. The first partial factor is that as a result of the radial flow field applied on the carrying surface of the dryer of the invention, one achieves a smaller distance between the web and the carrying surface than is obtained in conventional apparatus. Another partial factor is that owing to the radial flow pattern, its flow cross section varies in configuration and the turbulence introduced thereby improves the heat transfer. The third partial factor is that in the dryer of the invention no ejection of air to the next nozzle is encountered. The reduction of the specific energy consumption in the dryer of the invention is partly due to the lower specific resistance, compared with other equivalent designs, of the nozzle slit applied in the invention and partly to the circumstance that in the invention no flow guiding members are needed which would dissipate pressure (i.e., energy). The higher stabilizing capacity of the carrying surface in the dryer of the invention, compared with dryers of prior art, is partly a result of the avoidance, already mentioned, of ejection into the air space of the next nozzle, and partly is due to the fact that the radial flow field applied in this dryer binds the web symmetrically in all directions. DESCRIPTION OF THE DRAWINGS In the following, the invention is described in detail with reference being made to certain embodiment examples of the invention, presented in the figures of the attached drawing, but to the details of which the invention is not confined. FIG. 1 displays, axonometrically, partly in section a view of the air-supported dryer of the invention. FIG. 2 shows, viewed from above, part of the web supporting plane consisting of nozzle members, in a dryer of the invention. FIG. 3 presents a central axial section through the nozzle member employed in the floating dryer of the invention. FIG. 4 shows another embodiment of the invention, presented as in FIG. 2, the nozzle elements in this embodiment consisting directly of specially shaped portions of the top wall of the distributor headers. FIG. 5 shows the section carried along line V--V in FIG. 4. DESCRIPTION OF THE PREFERRED EMBODIMENTS The floating dryer presented in FIG. 1 consists of a box-type frame part 10, with the carrying plane T--T of the dryer spaced the distance H from its top margin 10a (FIG. 3). The material web to be dried, W, (a paper web for instance) is conducted to pass over the carrying plane T--T, using means known in the art, which need not be more fully described in this connection. As shown in FIG. 1, there has been arranged in the housing 10 an entry passage 11a for the drying gas (air for instance) and on the other end of the housing 10, a drying gas exit passage 11b. The entrance of the drying gas is indicated by the arrow A and its exit by arrow E. Over the passages 11a and 11b have been fitted distribution headers 12a, 12b, 12c etc. transversal to the direction of travel F of the web. The distribution headers 12 open at one end, on the underside, into the entry duct 11a, the other end being closed. Connected with the distribution headers 12 is a set of nozzle members 22 presenting, as taught by the invention, an annular nozzle slit, and these nozzle members communicating by respective connecting pipes 26 with the distribution header 12. The carrying surfaces 24 of the nozzle members 22 define the carrying plane T--T of one air-supported dryer, and there is a plurality of such nozzle members 22 arranged are after the other in the direction of web travel and side by side, i.e., transverse to the direction of web travel. The disposition of the nozzle members 22 with reference to each other is illustrated in FIG. 2, and FIG. 3 illustrates the detailed design of a typical one of the nozzle members 22. As shown in FIG. 3, the nozzle member 22 is constituted by an outer member 50 having an upwardly and outwardly extending frusto-conical surface comprising the carrying surface 24 and defining a central aperture and which terminates in a downwardly extending skirt 27 and an inner guiding member 23 located in the aperture defined by the carrying surface 24, also having a frusto-conical configuration. The carrying surface 24 has an integral portion having a radius of curvature R which communicates with the connecting pipe or gas supply tube 26 of the nozzle member 22 which itself is in fluid communication with the header 12. An annular nozzle slit s is defined between the inner surface of outer member 50 and the outer surface of the inner member 23. As noted above, the carrying surface of the nozzle member is frusto-conical, its angle α being preferably between 1° and 10°. The radius of curvature R of the outer member 50 is preferably considerably larger than the radius of curvature r of its outer margin. The inner guiding member 23 guides the entering flow, and as shown in FIG. 3 this member is plate-like so that it has on its margins, upwardly turned edges defining a frusto-conical surface having an angle β preferably about 45°. The central part of the guiding member 23 has been provided with perforations 25, which communicate with a pipe 28 running inside the tube 26. The guiding member 23 may also be carried out e.g. so that it directly communicates on its underside with the tube 26 of the nozzle member 22. The operation of the nozzle member 22 may be regulated, for instance, by making the guiding member 23 adjustably controllable horizontally and/or vertically. In this way one is able to influence not only the air flow rate but also the configuration of the annular flow field b discharging through the nozzle element 22. In FIG. 3, the central axis of the nozzle member 22 has been denoted by K--K and the air-guiding parts of the nozzle member display circular symmetry with reference to the central axis K--K. In the floating dryer of the invention, the central axes K--K of the nozzle members 22 are perpendicular with respect to the carrying plane T--T of the dryer. It is possible according to the invention also to use nozzle elements of a kind deviating from FIG. 3, for instance nozzle members which display elliptical symmetry with reference to the axis corresponding to axis K--K. It is possible in that case, by orienting in a suitable manner the longer and shorter diameter directions of the elliptical annular carrying surface, with reference to the direction of travel F of the web W, to influence the air distribution and also the web stabilizing. FIG. 2 illustrates one example of the mutual location of the nozzle members 22 of the invention with respect to each other. In this particular configuration there are nozzle members in rows transversal to the direction of travel F of the web W, arranged in a zigzag fashion so that the imaginary triangle obtained by joining the central axes of three mutually adjacent nozzle members 22 (in the carrying plane T--T) is substantially equilateral. The air-borne drier present in the figures and its nozzle members 22 operate as follows. The drying gas flow is introduced through the entrance passage 11a into the distribution headers 12a, 12b, 12c etc. whence it is divided as flow B,C into the tubes 26 of the nozzle members 22 and thereby as flow a further to the radial flow b in contiguity with the carrying surface 24. This flow b causes between the carrying surface 24 and the web W the carrying effect known in prior art. More particularly, by the gas flow discharging from the nozzle slits s in the radial directions illustrated as b in FIGS. 2 and 3 by virtue of the known Coanda effect discussed above in substantially parallel relationship to the web, an extremely efficient web-stabilizing effect is produced on the web due to the subatmospheric pressure created thereby. By virtue of the above, it is only necessary to effect such action on one side of the web while, additionally, the increased flow area resulting from the radial direction of the gas flow increases the turbulence of the flow and thereby improves the transfer of heat into the web. The radial flows b turn, after the edge 27, into downwardly directed flows c, and from the interstices 30 of the distribution headers 12 the gases are directed as flows D through the gratings 29 to the exit passage 11b, as exit flow E. As shown in FIGS. 2 and 3, also at the flow guide member 23 gases are brought into contiguity with the web W. As shown in FIG. 3, this is accomplished in that through the pipe 28 there is directed onto the web a flow field e, which is entrained along with the flow b, producing favourable effects. In the invention the angle α of the annular part formed by the carrying surface 24 is so selected that the cross section of the radial flow b is substantially constant at various points of the carrying surface 24. One may furthermore shape the annular flow passage between the inner part of the annular part with radius of curvature R and the guiding member 23, in view of appropriate air distribution in the radial flow field b. One may also arrange lands between the parts 24 and 23 for confining the flow, e.g. so that the flow in the field b is more strongly directed to those points where the vertical flow c has a larger cross section in the interstices of the nozzle members 22. It is even otherwise possible to shape the configuration of the carrying surface 24, both in the sections parallelling the flow b and in sections at right angles thereto, with a view to obtaining for the flow field b the most favourable shape possible and the best distribution, considering the uniform supporting and stability of the web W and the drying efficiency. The air has been conducted into the distribution headers 12a', 12b' etc. of the embodiment of the invention illustrated in FIGS. 4 and 5 similarly as in FIG. 1. The nozzles of FIGS. 4 and 5 lack the air tubes 26 described above, instead of which the carrying surfaces 24' of the nozzles are directly formed by the cover parts 31 of the distribution headers 12a', 12b' etc., there having been formed in these cover parts, in a row, annular nozzle slits so that these are confined on the inside starting from the inner part of the distribution headers by parts 32 with radius of curvature R, their immediate continuation consisting of conical parts constituting the carrying surface 24' and which have been shaped of the material of the distribution header cover 31. In the manner described above there is formed in connection with said carrying surfaces 24', an array of substantially radially disposed flow fields b', which turn to become flows c' in the interstices 30 of the distribution headers 12a', 12b' etc. As shown in FIGS. 4 and 5, the flow is guided by saucer members 23' which in this case are unperforated; thus in this embodiment of the invention no central air is used in the nozzles. The saucer parts 23' attach by projections 32 to the carrying surfaces 24', where appropriate grooves or recesses have been provided for the projections 32. The projections 32 may be so dimensioned and placed that they confine the flow field b' in such manner that two adjacent nozzles will not blow straight against each other. The flow e; e' coming from the site of the guiding members 23a; 23b may be employed, for instance, to regulate the distance H at which the web W is held from the carrying surface. The nozzle members 22 are placed in appropriate manner relative to each other, keeping in mind a uniform supporting action and drying, e.g. so that the streaking of the web can be avoided and the highest uniformity is achieved in the moisture profile. In such case the placement of the nozzle members 22 may differ e.g. from that which has been shown in FIGS. 1, 2 and 4.

Apparatus for drying a web, such as a paper web, including a plurality of nozzle members successively located one after the other both in and transverse to the direction of travel of the web, each of the nozzle members defining a substantially annular slit and a carrying surface associated with the slit for directing gaseous drying fluid substantially contiguous with the carrying surface in a substantially radial flow field relative to the annular slit and in a direction substantially parallel to the web.

This patent application claims priority to U.S. patent application 60/118,904, filed on Feb. 5, 1999, and to International patent application PCT/US00/02954 filed on Feb. 4, 2000, copies of which are incorporated by reference. The United States Government may have rights to this invention pursuant to the National Institute of Health (NIH), National Center for Research Resources, Grant No. RR-08119. FIELD OF THE INVENTION This invention relates to nanoparticle cadmium sulfide (CdS) fluorescent probes. Preferably, this invention relates to CdS nanoparticles formed in the presence of an amine-terminated dendrimer and/or polyphosphate-stabilized CdS particles both with average diameters or other critical dimensions (CDs) of several nanometers (nm). BACKGROUND There is presently widespread interest in the physical and optical properties of semiconductor particles with average diameters or CdS measured in nanometers. These particles are often called nanoparticles or quantum dots. The optical properties of such particles depends on their size [Martin, C. R.; Mitchell, D. T., Anal. Chem . (1998) 322A-327A]. Such particles display optical and physical properties which are intermediate between those of the bulk material and those of the isolated molecules. For example, the optical absorption of bulk CdSe typically extends to 690 nm. The longest absorption band shifts to 530 nm for CdSe nanoparticles with 4 nm average diameters [Bawendi, M. G.; et al., Annu. Rev. Phys. Chem . (1990) 41, 477-496]. Sizes of nanoparticies are usually measured by average diameters of equivalent spherical particles. For particles that are not at least approximately spherical, the smallest dimension (called critical dimension or CD) is often used. In nanoparticles a large percentage of the atoms are at the surface, rather than in the bulk phase. Consequently, the chemical and physical properties of the material, such as the melting point or phase transition temperature, are affected by the particle size. Semiconductor nanoparticles can be made from a wide variety of materials including, but not limited to CdS, ZnS, Cd 3 P 2 , PbS, TiO 2 , ZnO, CdSe, silicon, porous silicon, oxidized silicon, and Ga/InN/GaN. Semiconductor nanoparticles frequently display photoluminescence and sometimes electroluminescence. For example see Dabbousi, B. O., et al., Appl. Phys. Lett . (1995) 66(11), 1316-1318; Colvin, V. L., et al., Nature , (1994) 370, 354-357; Zhang, L., et al., J. Phys. Chem. B . (1997) 101 (35), 874-6878; Artemyev, M. V., et al, J. Appl. Phys ., (1997) 81(10), 6975-6977; Huang, J., et al., Appl. Phys. Lett . (1997) 70(18), 2335-2337; and Artemyev, M. V., et al., J. Crys. Growth , (1988) 184/185, 374-376. Additionally, some nanoparticles can form self-assembled arrays. Nanoparticles are being extensively studied for use in optoelectronic displays. Photophysical studies of nanoparticles have been hindered by the lack of reproducible preparations of homogeneous size. The particle size frequently changes with time following preparation. Particle surface is coated with another semiconductor or other chemical species to stabilize the particle [Correa-Duarte, M. A., et al., Chem. Phys. Letts . (1998) 286, 497-501; Hines, M. A., et al., J. Phys. Chem . (1996) 100, 468-471; and Sooklal, K., et al., J. Phys. Chem . (1996) 100, 4551-4555]. There are several examples of fluorescing cadmium sulfide nanoparticles. Tata, et al. use emulsions [Tata, M., et al., Colloids and Surfaces , 127, 39 (1997)]. Fluorescence of CdS nanocrystals have been observed by low temperature microscopy. Blanton, et al. show fluorescence from 5.5 nm diameter CdS nanocrystals with excitation of 800 nm and emission centered around 486 nm [Blanton, S., et al., Chem. Phys. Letts ., 229, 317 (1994)]. Tittel, et al. noticed fluorescence of CdS nanocrystals by low temperature confocal microscopy [Tittel, J., et al., J. Phys. Chem. B , 101(16) (1997) 3013-3016]. A 64 branch poly(propylene imine) dendritic box can trap a Rose Bengal molecule (i.e., a polyhalogenated tetracyclic carboxylic acid dye) to allow it to strongly fluoresce since it is isolated from surrounding quenching molecules and solvents [Meijer, et al., Polym. Mater. Sci. Eng ., (1995) 73, 123]. While the absorption and emission spectra of nanoparticles have been widely studied, the scope of these measurements were typically limited to using the optical spectra to determine the average size of the particles. There have been relatively few studies of the time-resolved photophysical properties of these particles. The emission from silicon nanoparticles has been reported as unpolarized [Brus, L. E., et al., J. Am. Chem. Soc . (1995) 117, 2915-2922] or polarized [Andrianov, A. V., et al., JETP Lett . (1993) 58, 427-430; Kovalev, D., et al., Phys. Rev. Letts . (1997) 79(1), 119-122; and Koch, F., et al., J. Luminesc ., (1996) 70, 320-332]. Polarized emission has also been reported for CdSe [Chamarro, M., et al., Jpn. J. Appl. Phys . (1995) 34, 12-14; and Bawendi, M. G., et al., J. Chem. Phys . (1992) 96(2), 946-954]. However, in these cases the polarization is either negative or becomes negative in a manner suggesting a process occurring within the nanoparticle. Such behavior would not be useful for a fluorescence probe for which the polarization is expected to depend on rotational diffusion. The increasing availability of homogeneous sized nanoparticles suggests more detailed studies of their photophysical properties, which in turn could allow their use as biochemical probes. The first reports of such particles as cellular labels have just appeared [Bruchez, M., et al., Science (1998) 281, 2013-2016; and Chan, W., et al., Science (1998) 281, 2016-2018]. CdS particles have also been synthesized which bind DNA and display spectral changes upon DNA binding [Mahtab, R., et al., J. Am. Chem. Soc . (1996) 118, 7028-7032; and Murphy, C. J., et al., Proc. Materials Res. Soc . (1997) 452, 597-600]. U.S. Pat. No. 5,938,934 to Balogh et al., describes use of dendrimers as hosts for many materials including semiconductors. However the nanoparticles are somewhat large for use as a probe based on size. Only example 15 discloses cadmiums sulfide. However dangerous sulfide gas is used over prolonged periods of time. SUMMARY This invention describes fabrication methods, spectroscopy, probes and other applications for semiconductor nanoparticles. The preferred embodiments are two types of cadmium sulfide (CdS) nanoparticles. CdS nanoparticles formed in the presence of an amine-terminated dendrimer show blue emission. The emission wavelength of these nanoparticles depends on the excitation wavelength. These CdS/dendrimer nanoparticles display a new constant positive polarized blue emission. Polyphosphate-stabilized CdS nanoparticles are described that display a longer wavelength red emission maximum than bulk CdS and display a zero anisotropy for all excitation wavelengths. Both nanoparticles display strongly heterogeneous intensity decays with mean decay times of 93 ns and 10 μs for the blue and red emitting particles, respectively. Both types of nanoparticles were several times more photostable upon continuous illumination than fluorescein. In spite of the long decay times the nanoparticles are mostly insensitive to dissolved oxygen but are quenched by iodide. These nanoparticles can provide a new class of luminophores for use in chemical sensing, DNA sequencing, high throughput screening, fluorescence polarization immunoassays, time-gated immunoassays, time-resolved immunoassays, enzyme-linked immunosorbent assay (ELISA) assays, filtration testing, and targeted tagging and other applications. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows absorption and emission spectra for the blue emitting CdS/dendrimer nanoparticle in methanol at room temperature. The excitation spectrum of this nanoparticles overlaps with the absorption spectrum. Also shown are the excitation and emission anisotropy spectra, also in methanol at room temperature. FIG. 2 shows photostability tests of the CdS/dendrimer and polyphosphate-stabilized (PPS) nanoparticles. The sample was contained in a standard 1 cm×cm (4 mL) cuvette. The incident power was 30 mW at 405 nm from a frequency-doubled Ti:Sapphire laser, 80 MHz, 200 fs, which was focused with a 2 cm focal length lens. Also shown is the intensity from fluorescein, pH 8, under comparable conditions. When illuminated with the output of a 450 W xenon lamp (385 nm for blue and 405 nm for red nanoparticles) there was no observable photobleaching. FIG. 3 shows emission spectra of the CdS/dendrimer composite for different excitation wavelengths. Also shown as the dashed line is the transmission profile of the filter used for the time-resolved measurements. FIG. 4 shows a frequency-domain intensity decay of the CdS/dendrimer nanoparticle for excitation at 395 nm (top) and 325 nm (bottom). This solid line shows the best three decay time fit to the data. FIG. 5 shows time-dependent intensity decays of the nanoparticles reconstructed from the frequency-domain data (Tables I and II). FIG. 6 shows a frequency-domain anisotropy decay of the CdS/dendrimer nanoparticle for excitation at 395 nm, at room temperature in methanol. FIG. 7 shows absorption (A) and emission (F) spectra of the CdS/PPS nanoparticles. In this case the emission spectra were found to be independent of excitation wavelengths from 325 to 450 nm. The dashed line shows the transmission of the filter used to record the time-resolved data. FIG. 8 shows excitation anisotropy spectra of the CdS/PPS nanoparticles in 80% glycerol at −60° C. (dots). Also shown are the temperature dependent spectra in 80% glycerol. FIG. 9 shows a frequency-domain intensity decay of the CdS/PPS nanoparticles for excitation at 442 nm (top) and 325 nm (bottom). The solid lines show the best three decay time fits to the data. FIG. 10 shows the effect of oxygen on the emission spectra of the CdS/dendrimer and CdS/PPS nanoparticles. FIG. 11 shows the effect of acrylamide and iodide on the emission spectra of the CdS/dendrimer and CdS/PPS nanoparticles. FIG. 12 shows intensity decays of the CdS/dendrimer (top) and CdS/PPS nanoparticles (bottom) in the absence and presence of 0.2 M acrylamide or 0.2 M iodide. These measurements were done independently of those presented in FIGS. 4 and 9. For the CdS/dendrimer nanoparticle (top panel) the recovered average lifetimes (τ=Σf i τ i ) are: 106.0 ns for not quenched (), 73.7 ns in presence of 0.2 M acrylamide (∘) and 36.7 ns in presence of 0.2 M KI (▾). For the CdS/PPS nanoparticles (lower panel) average lifetimes are 9.80 μs for not quenched (), 8.45 μs in presence of 0.2 M acrylamide (not shown), and 4.09 μs in presence 0.2 M KI (▾). DETAILED DESCRIPTION This invention describes detailed studies of the steady state and time-resolved emission semiconductor nanoparticles. The preferred embodiments are two types of stabilized CdS particles. The first type of CdS nanoparticles were fabricated in the presence of a dendrimer and display blue emission. The second type of CdS particles were stabilized with polyphosphate and display red emission. Semiconductor nanoparticles with fluoresce and/or luminesce more intensely and often at wavelengths shifted from their bulk counterparts. The nanoparticles of the present invention luminesce most strongly when they have average diameters and/or critical dimensions less than 5 nm. The nanoparticles of the present invention have a very narrow distribution of diameters and/or critical dimensions. In the preferred mode of this invention, at least 90% of a nanoparticle powder has critical dimensions of no more than +/−15% from the average diameter and/or critical dimension of the powder. This narrow particle size distribution is extremely important for maximizing emission intensity and other fluorescent properties. The semiconductor nanoparticles of the present invention may be only one semiconductor, composites of several materials in each nanoparticle, and/or mixtures of different nanoparticles (e.g., powders, agglomerates, and/or aggregates). The individual nanoparticles can be uncoated, coated, partially coated, attached to a molecule, and/or trapped in a nanoscopic volumetric area. In one contemplated example, a semiconductor nanoparticle is coated with another semiconductor. The coating preferably has a higher bandgap than the core nanoparticle. In another contemplated example, electrically non-conductive coatings or anchor molecules control the size and spacing of the semiconductive nanoparticles. Coatings can also be used to protect the core nanoparticle from other effects such as, but not limited to, certain wavelengths, oxidation, quenching, size changes, size distribution broadening, and electronic conductivity. There may be more than one coating layer and/or material. The nanoparticles of the present invention have at several important improvements. First, the dendrimer-based and other types of template-based nanoparticles show polarized emission. Polarization offers many advantages and an additional variable over prior fluorescent nanoparticle spectroscopy. Second, the nanoparticles of the present invention are very resistant to quenching by oxygen or other dissolved species. This important advance avoids the quenching problems that plague much of fluorescence spectroscopy. Third, the nanoparticles of the present invention have long wavelength emission. Emission wavelengths of above 500 nm possible with the present invention are especially suitable for biological sensing and minimize autofluorescent noise. Fourth, the nanoparticles of the present invention have long lifetimes. Lifetimes of 30 ns to well over 100 ns are possible with this invention even in the presence of fluorescence quenchers. Long lifetimes allow use of smaller and less expensive spectrometers, sensors and detectors. The combination of long lifetimes with long fluorescence decay times are particularly valuable. This invention's preferred mode describes solution phase nanofabrication of semiconductor nanoparticles. Solution phase nanofabrication is much less expensive than most types of nanofabrication using vacuum systems, electrochemistry, special ball mills, electric arcs, gas phase chemistry, etc. This invention's nanoparticles can be made in bulk or within a template such as, but not limited to, a dendrimer membrane or dendrimer-modified optical fiber. This invention avoids the use of dangerous and expensive reactive gases such as sulfide gas. CdS/Dendrimer Nanoparticle FIG. 1 shows the absorption and emission spectra of the CdS/dendrimer particles. There is a substantial Stokes' shift from 330 to 480 nm. Such a large Stokes' shift is a favorable property because the emission of the nanoparticles will be observable without homo-energy transfer between the particles. Also, because of the substantial shift it should be relatively easy to eliminate scattered light from the detected signal by optical filtering. The term nanoparticle in this invention is meant to include nanocomposites, clusters of nanoparticles, agglomerates of generally electrically isolated nanoparticles and surface-modified nanoparticles as well as single material particles. The emission intensity of the blue nanoparticles is relatively strong. The relative quantum yield is estimated by comparing the fluorescence intensity with that of a fluorophore of known quantum yield, and an equivalent optical density at the excitation wavelength of 350 nm. A solution of coumarin 1 in ethanol with a reported quantum yield of 0.73 was used as a quantum yield standard. This comparison yields an apparent or a relative quantum yield of 0.097. This value is not a molecular quantum yield because there is no consideration of the molar concentration of the nanoparticles. However, this value does indicate the relative brightness of the particles as compared to a known fluorophore. This value is somewhat lower than the previously reported quantum yield of approximately 0.17 [Murphy, C. J., Brauns, E. B., and Gearheart, L. (1997), Quantum dots as inorganic DNA-binding proteins, Proc. Materials Res. Soc . 452, 597-600]. It is possible that the quantum yields differ for different preparations of the nanoparticles. For use as a luminescent probe the signal from the nanoparticles must be stable with continual illumination. The emission intensities and/or emission spectra of nanoparticles occasionally depend on illumination. In contrast, the CdS/dendrimer particles appear to be reasonably stable and about two-fold more stable than fluorescein (FIG. 2 ). In these stability tests the fluorescein and nanoparticles were illuminated with the focused output of a frequency-doubled Ti:Sapphire laser. No changes in the emission intensity of the nanoparticles were found when illuminated with the output of a 450W xenon lamp and monochromator. For use as a biophysical probe of hydrodynamics a luminophore must display polarized emission. Since most nanoparticles are thought to be spherical, the emission is not expected to display any useful polarization. Importantly, the CdS/dendrimer nanoparticles of the present invention display high anisotropy (FIG. 1 ). This anisotropy increases progressively as the excitation wavelength increases across the long wavelengths side of the emission, from 350 to 430 nm. The emission anisotropy is relatively constant across the emission spectra. These properties, and the fact that the anisotropy does not exceed the usual limit of 0.4, suggest that the emission is due to a transition dipole similar to that found in excited organic molecules. The high and non-zero anisotropy also suggests that the excited state dipole is oriented within a fixed direction within the nanoparticles. A fixed direction for the electronic transition suggests the presence of some molecular features which define a preferred direction for the transition moment. While most nanoparticles are thought to be spherical, the shape of the CdS inside of the CdS/dendrimer nanoparticle is not known. Electron micrographs show that the particles and dendrimers exist as larger aggregates rather than as isolated species. Unfortunately, the presence of aggregates prevented determination of the particle shape. Our observation of a large non-zero anisotropy for these particles suggests an elongated shape for the quantum-confined state. This is the first constant positive polarized emission from CdS nanoparticles. The results in FIG. 2 suggest that CdS/dendrimer nanoparticles can serve as hydrodynamic probes for rotational motions on the 50 to 400 ns timescale (see FIG. 4 below). If the particle preparation has a single particle size, the emission spectra are expected to be independent of excitation wavelength. Hence we recorded the emission spectra for the CdS/dendrimer particles for a range of excitation wavelengths (FIG. 3 ). Longer excitation wavelengths results in a progressive shift of the emission spectra to longer wavelengths. This effect is reminiscent of the well-known red edge excitation shift observed for organic fluorophores in polar solvents. However, the molecular origin of the shift seen in FIG. 3 is different. In this case the shifts are probably due to the wavelength-dependent excitation of a selected sub-population of the particles at each wavelength. In particular, longer excitation wavelengths probably results in excitation of larger particles with a longer wavelength emission maximum. Hence this particular preparation of CdS/dendrimer particles appears to contain a range of particle sizes. However, we cannot presently exclude other explanations for the wavelength-dependent spectra seen in FIG. 3 . We examined the time-resolved intensity decay of the CdS/dendrimer particles using the frequency-domain (FD) method [J. R. Lakowicz and I. Gryczynski, Topic in Fluorescence Spectroscopy, Vol I, Techniques, Plenum Press, New York, pp 293-355]. The frequency responses were found to be complex (FIG. 4 ), indicating a number of widely spaced decay times. The FD data could not be fit to a single or double decay time model (Table I). Three decay times were needed for a reasonable fit to the data, with decay times ranging from 3.1 to 170 ns. The mean decay time is near 117 ns. There seems to be a modest effect of excitation wavelength. The mean decay time decreases from 117 ns for excitation at 395 nm to 93 ns for excitation at 325 nm. Such long decay times are a valuable property for a luminescent probe, particularly one which can be used as an anisotropy probe. The long decay time allows the anisotropy to be sensitive to motions on a timescale comparable to the mean lifetime. Hence, it is envisioned to use these nanoparticles as probes for the dynamics of large macro molecular structures, or even as model proteins since the nanoparticle size is comparable to the diameter of many proteins. To better visualize the intensity decays, the parameters (α i and τ i ) recovered from the least-squares analysis in Table I were used to reconstruct the time-dependent intensity decays (FIG. 5 ). The intensity is multi- or non-exponential at early times (insert), but does not display any long-lived microsecond components. While the intensity decay could be fit to three decay times, it is possible that the actual decay is more complex, and might be more accurately represented as a distribution of decay times. In the frequency-domain anisotropy decay of the CdS/dendrimer particles (FIG. 6 ), the differential polarized phase angles are rather low, with the largest phase angles centered near 1.0 MHz, suggesting rather long correlation times for the particles. Least squares analysis of the FD anisotropy data revealed a correlation time near 2.4 μs (Table I). Such a long correlation time is consistent with the observation that the CdS nanoparticles are aggregated with the dendrimers, or somehow present in a composite structure. Much shorter correlation times would be expected for particles with sizes near 2 nm that would be consistent with the optical properties. The time-zero anisotropy recovered from the FD anisotropy data is consistent with that expected from the excitation anisotropy spectra and the excitation wavelength. This agreement suggests that the anisotropy of these particles decays due to overall rotational motion, and not due to internal electronic properties of the particles. It is envisioned that these nanoparticles (especially when not aggregated) are useful as analogues of proteins or other macromolecules, and as internal cellular markers which could report the rate of rotational diffusion. Dendrimers are macromolecules such as poly(amidoamine-organosilicon) containing hydrophilic and hydrophobic nanoscopic domains. The dendrimer have a dense star architecture which is a macromolecular structure with chains that branch from a central initiator core. Dendrimers have narrow molecular weight distributions with specific sizes and shapes. The dendrimers grow larger with each generation. For example, a generation 4 dendrimer is smaller than a generation 5 dendrimer. Dendrimers also have highly functional and accessible terminal surfaces. In the preferred embodiment of this invention, this terminal surface has amine which can bind cadmium. In the present invention, each dendrimer preferably holds a plurality of cadmium sulfide or other semiconductor nanoparticles. Creating semiconductor nanoparticles in dendrimer-based nanoscopic molecular sponges and dendrimer-based network materials (e.g., elastomers, plastomer, coatings, films and membranes) are also envisioned. The present invention can any non-conductive system having nanoscopic domains capable of binding a semiconductor. Envisioned examples include, but are not limited to, dendrimers, star polymers, self-assembling polymers, and zeolites. Polyphosphate-Stabilized CdS Nanoparticles Other CdS nanoparticles in this invention, called CdS/PPS, have surfaces stabilized with polyphosphate (PPS). Absorption and emission spectra of these particles are shown in FIG. 7 . Compared to the CdS/dendrimer nanoparticles, these stabilized nanoparticles absorbs and emit at much longer wavelengths. Their average diameter was estimated to be 4 nm±15% by transmission electron microscopy. The spectra and intensities were found to be stable with prolonged illumination and at least four-fold more stable than fluorescein (FIG. 2 ). The emission intensity of these red-emitting particles is considerably weaker than the blue particles. The apparent quantum yield of the red particles was measured relative to 4-(dicyanomethylene)-2-methyl-6-(4-dimethylamino-styryl)-4H-pyran (DCM) in methanol, with an assumed quantum yield of 0.38. For equivalent optical densities at the excited wavelength of 442 nm, these particles display an apparent quantum yield of 0.015, and are thus less bright than the blue-emitting CdS/dendrimer nanoparticles. Compared to the blue-emitting nanoparticles, these red emitting particles display simpler properties. The emission spectra are independent of excitation wavelength, suggesting a narrow size distribution. The excitation spectrum (not shown) overlapped with the absorption spectrum. These nanoparticles can be made to have a long wavelength absorption above 480 nm. The absorption and excitation spectra of the CdS/dendrimer particles also appeared to be identical (FIG. 1 ). Excitation and emission anisotropy spectra of these polyphosphate-stabilized nanoparticles show zero anisotropy for all excitation and emission wavelengths. The zero anisotropy values could be due to rotational diffusion of the particles during these long luminescence decay (below). However, time-dependent decay of the anisotropy is not detected, as seen from the frequency-domain anisotropy data. The nanoparticles in 80% glycerol at −60° C. also show the anisotropies to be zero for excitation from 350 to 475 nm (FIG. 8 ). These results suggest that polarized emission is not a general property of nanoparticles, but requires special conditions of synthesis or stabilizers. The frequency-domain intensity decay of the PPS-stabilized nanoparticles is shown in FIG. 9 . The intensity decay is complex, again requiring at least three decay times to fit the data (Table Ii). The intensity decay in the time domain is shown in FIG. 5 . The decay times range from 150 ns to 25.3 μs, with a mean decay time near 9 μs. Once again there was an effect of excitation wavelength, but less than seen with the blue-emitting CdS/dendrimer nanoparticles. Observation of microsecond decay times for these red emitting particles is an important result. There is currently considerable interest in using red or near infrared (NIR) probes for non-invasive and/or in-vivo measurements. Most such probes display relatively short decay times, typically less than 1 ns. While a few metal-ligand complexes are known to emit in the red and to display long lifetimes the choice of probes with long lifetimes are limited. These intensity decay data for the polyphosphate-stabilized nanoparticles suggest that such nanoparticle probes can provide a new class of luminophores with both long wavelength emission and long decay times. Commonly used quenchers sometimes do not affect nanoparticle emission. The effect of oxygen are shown in FIG. 10 . Dissolved oxygen had a modest effect on the intensity from the CdS/dendrimer particles, with the emission being quenched by about 40% for equilibration at one atmosphere of oxygen (top). Remarkably, dissolved oxygen had no effect on the emission from the CdS/PPS particles (lower panel). This is particularly surprising given the long intensity decay time of these particles. The absence of quenching by oxygen could be a valuable result. For instance, the absence of oxygen quenching is a valuable property of the lanthanides, allowing long decay times in samples exposed to air. These results suggest that some nanoparticles may be insensitive to oxygen, and thus useful for high sensitivity gated detection as is used in the lanthanide-based immunoassays. The CdS/dendrimer nanoparticles were quenched by both iodide and acrylamide (FIG. 11, top). The CdS/PPS particles were quenched by iodide but not significantly by acrylamide (bottom). The quenching observed for both types of nanoparticles seems to be at least partially dynamic, as seen by the decrease in mean decay time (Table III). Many potential applications of nanoparticles as luminescent probes are envisioned. Red-NIR emitting probes with long decay times and optionally resistance to oxygen quenching are envisioned. A favorable property of the nanoparticles is the long intensity decay times. This allows those particles which display anisotropy to be used in hydrodynamic probes on the timescales ranging from hundreds of nanoseconds to microseconds. This is a timescale not usually available to fluorescence without the use of specialized luminophores. The luminescence decay times can be adjusted by changes in nanoparticles and nanoparticle composition, morphology, size, shape and surface modifications. It is envisioned that the nanoparticles of the present invention could display resonance energy transfer. For example, the nanoparticles could display resonance energy transfer to absorbing dyes or could display Förster transfer. Sensors incorporating the nanoparticles of the present invention are also envisioned for chemical, biological, optical and other applications. Preferred embodiments are sensors for important species such as Ca 2+ , pH and/or chloride. Attachment of analyte-dependent absorbers to the nanoparticles are envisioned for analyte-dependent emission. Preferred methods of making the nanoparticles of the present invention are described in Examples 1-2. Preferred methods of spectroscopic measurements of the nanoparticles of the present invention are described in Example 3. EXAMPLE 1 Nanofabrication of CdS/dendrimer Nanoparticles The blue emitting CdS particles were prepared in the presence of poly(aminoamine) STARBURST® dendrimer, generation 4.0 (bow Corning, Midland, Mich.; Dendritech™, Inc., Midland, Mich.; Michigan Molecular Institute, Midland, Mich.; Aldrich, Allentown, Pa.). The STARBURST® dendrimer (PAMAM) of generation 4.0 was purchased from Aldrich. This dendrimer is expected to have 64 surface amino groups. Based on the manufacturer's value of the dendrimer weight fractions in methanol, and the known dendrimer densities, we prepared dendrimer stock solutions of 1.14×10 −4 M in methanol under a N 2 atmosphere at 10° C. The 2.0 mM stock solutions of Cd 2+ and S 2− were prepared by dissolving 62 mg of Cd(NO 3 )2.4H 2 O (Baker) in 100 mL of methanol, and by dissolving 15 mg Na 2 S (Alfa) in 100 mL of methanol. The Cd 2+ and S 2− stock solutions were freshly prepared. In the standard incremental addition procedure, an 0.50 mL aliquot of Cd 2+ stock solution was added to 10 mL of the dendrimer stock solution at 10° C., followed by addition of an 0.50 mL aliquot of S 2− stock solution. The Cd 2+ and S 2− additions were repeated 10 times. The resulting solution was colorless and glowed bright blue under UV Illumination. The product was stored in a freezer and did not show any evidence of precipitation for months. This nanoparticle dendrimer composite was stable for long periods of time in neutral methanol. EXAMPLE 2 Nanofabrication of CdS/PPS Nanoparticles The red emitting particles are also composed of CdS, but stabilized with polyphosphate [Mahtab, R., Rogers, J. P., and Murphy, C. J. (1995), Protein-sized quantum dot luminescence can distinguish between “straight”, “bent,” and “kinked” oligonucleotides, J. Am. Chem. Soc . 117, 9099-9100]. For the polyphosphate-stabilized (PPS) CdS/PPS nanoparticles, 2×10 −4 M Cd(NO 3 ) 2 .4H 2 O in degassed water was mixed with an equivalent amount of sodium polyphosphate, Na 6 (PO 3 ) 6 . Solid Na 2 S was added, with vigorous stirring, to yield 2×10 −4 M sulfide. The solution immediately turned yellow. Under UV light, the solution glowed red-orange. EXAMPLE 3 Spectroscopic Measurements Frequency-domain (FD) intensity and anisotropy decays were measured with a fluorescence spectrometer and standard fluorescence techniques [J. R. Lakowicz and I. Gryczynski, Topic in Fluorescence Spectroscopy, Vol I, Techniques, Plenum Press, New York, pp 293-355]. The excitation source was a HeCd laser with an emission wavelength of 325 nm or 442 nm. The continuous output of this laser was amplitude modulated with a Pockels' cell. The FD data were interpreted in terms of the multi-exponential model: l     ( t ) = ∑ i     α i     exp     ( - t / τ i ) ( 1 ) where α i are the pre-exponential factors and τ i are the decay times. The fractional contribution of each decay time component to the steady state emission is given by f i = ( α i  τ i ) / ( ∑ j     α j  τ j ) ( 2 ) Frequency-domain anisotropy decay data were measured and analyzed as described previously [Lakowicz, J. R., Cherek, H., Kusba, J., Gryczynski, I., and Johnson, M. L. (1993), Review of fluorescence anisotropy decay analysis by frequency-domain fluorescence spectroscopy, J. Fluoresc . 3, 103-116] in terms of multiple correlation times: r     ( t ) = ∑ k     r 0  k     exp     ( - t / θ k ) ( 3 ) In this expression r 0k is the fractional anisotropy amplitude which decays with a correlation time θ k . The foregoing examples are illustrative embodiments of the invention and are merely exemplary. A person skilled in the art may make variations and modification without departing from the spirit and scope of the invention. All such modifications and variations are intended to be included within the scope of the invention as described in this specification and the appended claims. TABLE I Frequency-domain intensity and anisotropy decays of the CdS/dendrimer nanoparticles Exc. (nm) n a τ (ns) α i f i X 2 R 395 1 61.8 1.0 1.0 1,136.9 2 6.2 0.747 0.137 116.0 0.253 0.863 32.0 3 3.1 0.748 0.090 50.2 0.163 0.319 169.8 0.089 0.591 1.1 325 1 52.3 1.0 1.0 991.5 2 7.8 0.705 0.160 97.9 0.295 0.890 37.5 3 2.7 0.699 0.080 39.5 0.205 0.341 142.8 0.096 0.579 1.7 a Number of exponents At an excitation of 395 nm and an n a of 1, the following anisotropy decay values are seen: θ k =2,430.5 ns; r 0k =0.228; and X 2 R =0.6 TABLE II Frequency-domain intensity decay of the Cd 2+ enriched nanoparticles Exc. (nm) n a τ (ns) α i f i X 2 R 442 1 597.50 1.00 1.00 1,656 2 290.40 0.932 0.448 4,907 0.068 0.552 242.90 3 150.00 0.749 0.188 1,171 0.243 0.476 25,320 0.008 0.336 2.70 325 1 680.20 1.00 1.00 1212.30 2 425.00 0.932 0.474 6,471 0.068 0.526 93.50 3 241.60 0.717 0.227 1,173 0.273 0.421 27,783 0.010 0.352 2.90 a Number of exponents TABLE III Intensity decay of the nanoparticles with and without quenchers. τ(avgas) τ 1 τ 2 τ 3 Compound/Conditions (ns) α 1 (ns) α 2 (ns) α 3 (ns) X 2 R blue, no quencher 106.0 0.698 4.91 0.256 57.7 0.046 214.2 2.2 blue + 0.2 M acrylamide 73.7 0.737 1.07 0.190 18.0 0.073 105.9 4.2 blue + 0.2 M iodide 36.7 0.786 1.11 0.175 11.2 0.039 67.3 4.6 red, no quencher 9.80 0.652 232.5 0.337 1073.3 0.011 2580 3.8 red + 0.2 M acrylamide 8.54 0.761 229.3 0.229 1173.0 0.010 2349 1.9 red + 0.2 M iodide 4.09 0.738 56.3 0.243 673.7 0.019 858.2 3.2 b The excitation was 325 nm. The emission filter for the blue particles was an interference filter 500 +/− 20 nm. The emission filter for the red particles was a long pass filter at 580 nm.   c  τ  ( avgas ) = ∑ i       f i     τ  ( avgas )  i ; f i = α i  τ i / ( ∑ i       α j  τ j )

The steady state and time resolved luminescence spectral properties of two types of novel CdS nanoparticles and nanoparticles are described. CdS nanoparticles formed in the presence of an amine-terminated dendrimer show blue emission. The emission wavelength of these nanoparticles depended on the excitation wavelength. The CdS/dendrimer nanoparticles display polarized emission with the anisotropy rising progressively from 340 to 420 nm excitation, reaching a maximal anisotropy value in excess of 0.3. A new constant positive polarized emission from luminescent nanoparticles is also described. Polyphosphate-stabilized CdS nanoparticles are described that display a longer wavelength red emission maximum than bulk CdS and display a zero anisotropy for all excitation wavelengths. Both nanoparticles display strongly heterogeneous intensity decays with mean decay times of 93 ns and 10 μs for the blue and red emitting particles, respectively. Both types of nanoparticles were several times more photostable upon continous illumination than fluorescein. In spite of the long decay times the nanoparticles are mostly insensitive to dissolved oxygen but are quenched by iodide. These nanoparticles can provide a new class of luminophores for use in chemical sensing, DNA sequencing, high throughput screening and other applications.

FIELD OF THE INVENTION The field of the invention is papermaking. More particularly, the invention relates to a process for improving the dewatering of paper as it is being made. BACKGROUND OF THE INVENTION Paper is made by applying processed paper pulp to a fourdrenier machine. In order to remove the paper produced, it is necessary to drain the water from the paperstock thereon. The use of colloidal silica together with cationic starch has proved beneficial in providing drainage. It would be advantageous to provide a drainage method with improved results. SUMMARY OF THE INVENTION The invention is a method for dewatering used in a papermaking process. The method includes applying a low molecular weight cationic polymer to pulp (including recycled paperpulp); and then adding a colloidal silica and a high molecular weight charged acrylamide polymer. The low molecular weight (LMW) cationic polymers will be positively charged polymers having a molecular weight of at least 2000. Although polymers having molecular weights of 200,000 are acceptable. Preferred polymers include epichlorohydrin/dimethylamine (epi/DMA) and ethylene dichloride/ammonia copolymer (EDC/NH 3 ), diallyldimethylammonium chloride (polyDADMAC) copolymers and acrylamido N,N-dimethyl piperazine quaternary/acrylamide co-polymer. The broadest range afforded the low molecular weight polymers are 1000 to 500,00 Mw. The high molecular weight (HMW) charged polymers are preferably acrylamide polymers which can include either cationic monomers or anionic monomers. Generally they will have a Mw of at least 500,000. Higher molecular weight polymers having a molecular weight greater than 1,000,000 are most preferred. The low molecular weight cationic polymer preferably will be fed on a dry basis at 0.1 to 25 #/ton furnish. More preferably the low molecular weight polymer will be fed at 0.2 to 10 #/ton furnish. The high molecular weight charged acrylamide copolymer should be fed at 0.1 to 5 #/ton furnish on a dry basis. More preferably at 0.2 to 3 #/ton furnish. DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment, a low molecular weight cationic polymer is added to paper feedstock. This low molecular weight cationic polymer tends to neutralize the charge on the paper feedstock to facilitate coagulation thereof. Subsequent to this addition of low molecular weight polymer, a high molecular weight polyacrylamide and colloidal silica should be added to the paper feedstock. The process will work irregardless of the order of addition of the silica and the high molecular weight polymer with respect to each other. However, the order may be important for optimization of performance and that optimal order can vary with the mill system being treated. ANIONIC HIGH MOLECULAR WEIGHT FLOCCULANTS The high molecular weight anionic polymers are preferably water-soluble vinylic polymers containing monomers from the group acrylamide, acrylic acid, AMPS and/or admixtures thereof., and may also be either hydrolyzed acrylamide polymers or copolymers of acrylamide or its homologues, such as methacrylamide, with acrylic acid or its homologues, such as methacrylic acid, or perhaps even with monomers, such as maleic acid, itaconic acid or even monomers such as vinyl sulfonic acid, AMPS, and other sulfonate containing monomers. The anionic polymers may be homopolymers, copolymers, or terpolymers. The anionic polymers may also be sulfonate or phosphonate containing polymers which have been synthesized by modifying acrylamide polymers such a way as to obtain sulfonate or phosphonate substitution, or admixtures thereof. The most preferred high molecular weight copolymer are acrylic acid/acrylamide copolymer; and sulfonate containing polymers, such as 2-acrylamido-2-methylpropane sulfonate/acrylamide; acrylamido methane sulfonate/acrylamide; 2-acrylamido ethane sulfonate/acrylamide; 2-hydroxy-3-acrylamide propane sulfonate/acrylamide. Commonly accepted counter ions may be used for the salts such as sodium ion, potassium ion, etc. The acid or the salt form may be used. However, it is perferble to use the salt form of the charged polymers disclosed herein. The anionic polymers may be used in solid, powder form, aqueous, or may be used as water-in-oil emulsions where the polymer is dissolved in the dispersed water phase of these emulsions. It is preferred that the anionic polymers have a molecular weight of at least 500,000. The most preferred molecular weight is at least 1,000,000 with best results observed when the molecular weight is between 5-30 million. The anionic monomer should represent at least 2 mole percent of the copolymer and more preferably the anionic monomer will represent at least 20 mole percent of the over-all anionic high molecular weight polymers. By degree of substitution, we mean that the polymers contain randomly repeating monomer units containing chemical functionality which when dissolved in water become anionically charged, such as carboxylate groups, sulfonate groups, phosphonate groups, and the like. As an example a copolymer of acrylamide (AcAm) and acrylic Acid (AA) wherein the AcAm:AA monomer mole ratio is 90:10, would have a degree of substitution of 10 mole percent. Similarly copolymers of AcAm:AA with monomer mole ratios of 50:50 would have a degree of anionic substitution of 50 mole percent. CATIONIC HIGH MOLECULAR WEIGHT POLYMER FLOCCULANTS The cationic polymers used are preferably high molecular weight water soluble polymers having a weight average molecular weight of at least 500,000, preferably a weight average molecular weight of at least 1,000,000 and most preferably having a weight average molecular ranging from about 5,000,000 to 25,000,000. Exemplary high molecular weight cationic polymers include diallyldimethylammonium chloride/acrylamide copolymer; 1-acryloyl-4-methyl-piperazine methyl sulfate quat/(AMPIQ) acrylamide copolymer; dimethylaminoethylacrylate quaternary/acrylamide copolymer (DMAEA); dimethyl aminoethyl methacrylate quaternary (DMAEA)/acrylamide copolymer, methacrylamido propyl trimethylammonium chloride homopolymer (MAPTAC) and its acrylamide copolymer. It is generally preferred that the cationic polymer be an acrylamide polymer with a cationic comonomer. The cationic comonomer should represent at least 2 mole percent of the overall polymer, more preferably, the cationic comonomer will represent at least 20 mole present of the polymer. THE DISPERSED SILICA Preferably, the cationic or anionic polymers are used in combination with a dispersed silica having an average particle size ranging between about 1-100 nanometers (nm), preferably having a particle size ranging between 2-25 nm, and most preferably having a particle size ranging between about 2-15 nm. This dispersed silica, may be in the form of colloidal, silicic acid, silica sols, fumed silica, agglomerated silicic acid, silica gels, and precipitated silicas, as long as the particle size or ultimate particle size is within the ranges mentioned above. The dispersed silica is normally present at a weight ratio of cationic coagulant (i.e. LMW cationic polymer) to silica of from about 100:1 to about 1:1, and is preferably present at a ratio of from 10:1 to about 1:1. This combined admixture is used within a dry weight ratio of from about 20:1 to about 1:10 of high Mw polymer to silica, preferably between about 10:1 to about 1:5, and most preferably between about 8:1 to about 1:1. The following examples demonstrate the method of this invention. EXAMPLE 1 500 mls. paper stock mixed with the additives in the following order of addition: 1. low molecular weight cationic polymer; 2. high molecular weight polymer 3. colloidal silica. These samples were mixed after each addition of chemicals in a 500 ml. graduated cylinder, then the samples received 3 seconds mixing at 1000 rpm. The samples were then drained through a laboratory drainage tester; the first 5 seconds of filtrate being collected for testing. The results are provided in Table I. TABLE I__________________________________________________________________________HMW (lb/ton)* LMWPolymer Cationic Polymer Colloidal DrainageProductDry(lb/ton) Starch Product Dry(lb/ton) Silica 270 mLs/5 sec__________________________________________________________________________110 0.5 200 1.3 175110 0.75 200 1.3 190110 0.75 200 3.75 275110 1.0 200 1.3 180110 0.75 200 1.3. 0.75 195110 0.75 200 1.3. 0.75 200110 0.75 200 2.6. 0.75 205110 0.75 200 3.75. 0.75 295110 0.4 200 1.3. 0.75 1.3 195110 0.75 260 1.3 3.75 1.3 220120 0.5 200 1.3 205120 0.75 200 1.3 205120 1.0 200 1.3 0.75 240l20 0.75 200 1.3 0.75 340110 0 20 3.75 230110 0.75 20 3.75 280__________________________________________________________________________ *Pounds per ton 110 HMW acrylamide, acrylic acid copolymer, anionic, Mw ˜10 to 15 million 120 HMW acrylamide, DMAEA copolymer, cationic Mw ˜5 to 10 million 200 Crosslinked epi/DMA, LMW cationic Mw ˜50,000 260 Linear epi/DMA, LMW cationic polymer Mw ˜20,000 Colloidal silica 4-5 nm 270 Poly aluminum chloride and 260 (95:5 mole ratio) Cationic Starch Cationic potato starch, 0.035 degree of substitution EXAMPLE 2 500 mls. paper stock mixed with the following additives added while mixing the sample at 1000 rpm. The additives were added at 5 second intervals. 1. Low molecular weight cationic polymer. 2. High molecular weight polymer 3. Colloidal silica. The samples were then drained through a laboratory drainage tester with the first 5 seconds of filtrate being collected for testing. The results are provided in Table II. TABLE II__________________________________________________________________________HMW LMWPolymer Polymer Colloidal DrainageProduct Dry(lb/Ton) Product Dry(lb/Ton) Silica(lb/Ton) mLs/5 sec__________________________________________________________________________ 0.5 0 0 155110 0.75 200 1 2 245110 0.75 200 2 2 325110 0.75 200 3 2 340110 0.75 200 1 0 210110 0.75 200 2 0 265110 0.75 200 3 0 295110 0.75 210 1 230110 0.75 210 2 310110 0.75 210 2 305110 0.75 210 3 340110 0.75 210 2 2 365110 0.75 220 1 260110 0.75 220 2 285110 0.75 220 3 305110 0.75 230 1 265110 0.75 230 2 285110 0.75 230 3 315110 0.75 240 1 265110 0.75 240 2 2 295110 0.75 240 3 295110 0.75 250 1 140110 0.75 250 2 150110 0.75 250 3 180110 0.75 260 1 195110 0.75 260 2 230110 0.75 260 3 235110 0.75 270 1 170110 0.75 270 2 220110 0.75 270 3 250__________________________________________________________________________ LMW Cationic Polymers: 200 Crosslinked epi/DMA, LMW cationic Mw ˜50,000 260 Linear epi/DMA, LMW cationic polymer Mw ˜20,000 210 EDC/ammonia copolymer Mw ˜30,000 220 polyDADMAC, ˜100,000 MW 230 PolyDADMAC, ˜150,000 MW 240 PolyDADMAC, ˜200,000 MW 250 Acrylamide, DMAEM MCQ copolymer, HMW (MCQ=methyl chloride quat), Mw ˜10 to 15 million 270 Poly aluminum chloride and 260 (95:5 mole ratio) Colloidal Silica 4-5 nm, dosage on dry basis 110 Acrylic acid, acrylamide copolymer, HWM anionic, Mw ˜10 to 15 million EXAMPLE 3 Plant A has a six vat, cylinder machine currently producing recycled board for various end uses. Weights range from 50 to 150 lb/3000 sq. ft. with calipers in the 20-40 pt. range. The furnish is 100% recycled fiber. The current program consists of the following: 1. LMW 200 as a coagulant fed to the machine chest at dosages typically between 1 and 6 #/ton as needed to control the charge in the vats between -0.02 and 0.01 MEQ./ML. 2. HMW 110 fed as a flocculant after the screens to each individual vat through a bank of rotometers to control dosage. Dosages are typically in the range of 1 to 4 #/ton as needed for retention and drainage profile modification. 3. Colloidal silica fed directly into the post-dilution water for the HMW 110. After mixing with the dilution water and the HMW 110, passes through a static mixer, a distribution header and then through the rotometers mentioned above and onto the machine. Typical dosages to date have been in the range of 0.5 to 1.0 dry pounds per ton. 4. A cationic pregellatinized potato starch with 0.025 d.s. is added on one very high strength grade at 40 #/ton for added Ply-Bond. Bags of the starch are normally thrown into the beater at 15 minute intervals (depending on production rate) by the beater engineer. With the addition of the colloidal silica in the 0.5 to 1.0 #/ton (all colloidal silica dosages should be assumed to be in Dry #/ton unless stated otherwise) to dual polymer program we have seen the following results: 1. Within 10 minutes of adding the silica sheet moisture dropped from 7.5% to 1.5% moisture. This in turn resulted in the backtender reducing the stream in the high pressure dryers from 120 to 70 PSI. 2. After moistures were again in line, the machine was sped up to 10 to 15% without putting all the steam back in. On some of the heavier weights we have actually run out of stock before reaching their normal steam limited condition. On the lighter weight grades we normally run out of turbine speed before running out of steam. Steam savings even on the lighter grades are significant, normally 10 to 30%. 3. Vat drainage rates increased 30 to 50%. In general the vat drainages went from an initial 35 to 40 Schoppler-Riegler Freeness to a 15 to 20 level. The same results were seen using a laboratory drainage tester which increased from 150 mL/5 sec. to nearly 300 mL/5 sec. for a 500 ml. sample at 0.5-1.0% consistency. The vat level controls responded by adding more dilution water which lowered the proud consistency and resulted in a much improved sheet formation. 4. Retentions improved from a typical 85 to 92% up as high as 99% on the heavier weights. In general retention was improved significantly, to the point in fact that there were so few solids going to the saveall that we were having a very difficult time forming a mat without sweetener stock. On the lightest weight grades retention improvements of 10 to 25% were achieved over and above a reasonably well optimized dual polymer program. 5. Ply bonding, Mullen, and cockling were also improved as a result of the addition of silica. On their heavily refined grades they generally have to slow way back due to severe cockling and slow drying. The addition of the silica eliminated much of this problem and they have been able to speed up to record production rates on these grades. Ply Bond and Mullen also improved 10 to 30 points primarily due to better formation. 6. It is very important to note that the addition of starch is in no way necessary to the performance of this program. We have run both with and without starch and have never seen the starch have any bearing on program performance.

A method of enhancing the dewatering of paper during the papermaking process which includes adding a low molecular weight cationic coagulant and then colloidal silica and a high molecular weight flocculant.

BACKGROUND OF THE INVENTION This invention relates to an improved velocity transducer and more particularly to an angular velocity transducer for use in applications generally utilizing spinning rotor rate gyros. Errors have been experienced in the past in fluid filled instruments when thermal gradients are created within the fluid mass. A slight variation in density results throughout the fluid mass which when subjected to acceleration causes thermal currents to flow within the fluid mass. Internal forces from the thermally induced currents produce motion of internal moving members resulting in output in the absence of the normal input stimulus. External magnetic fields may also interact with the internal construction of a transducer producing output in the absence of the normal input stimulus. In shock and vibration environments, moving member motion in a preferred direction, normally referred to as rectification, may occur unless the moving member is effectively isolated from the instrument mounting base when it is subjected to such environments. Further errors may arise in an angular sensor if the moving member is not perfectly balanced about the pivot axis. The summation of these errors is generally much greater than tolerable system error. There is, therefore, a need for a velocity sensor for use in linear and angular velocity measurement applications, which is free from the errors induced by internal thermal gradients, external magnetic fields, external shock and vibration environments, and, in the case of angular transducers, imbalance about the pivot axis of the moving member. SUMMARY AND OBJECTS OF THE INVENTION A velocity transducer having a base member which is separable, with internal walls forming an internal closed channel when assembled. A fluid mass is disposed within the closed channel. A paddle assembly is pivotally mounted relative to the base member having a paddle member extending into the closed channel with the broad surfaces of the paddle member obstructing flow of the fluid mass through the channel. Electrical means are provided for retaining the paddle assembly in a predetermined position relative to the base member and for providing an electrical output related to movement of the paddle member. A return path for magnetic flux completely surrounds the means for retaining the paddle assembly serving to complete the magnetic circuit therein and to shield the assembly from induced electrical noise in the output caused by stray magnetic flux. An integrator receives the output providing an integrated output related to velocity of the base member relative to a predetermined axis. Means are provided in the integrator for preventing saturation of the integrator output in the absence of velocity applied to the base member. The integrated output has a pass band limited at the high frequency end by the sensing assembly mechanical response and the electrical characteristics of the output circuit. The pass band is limited at the low frequency end by the electrical characteristics of the integrator. Leaf spring pivot supports are disposed between the paddle assembly and the base member for stabilizing the paddle member during shock and vibration environments applied to the base member. In general, it is an object of the present invention to provide a velocity transducer substantially free from errors due to internal thermal gradients, external flux field effects, or externally applied shock vibration. Another object of the present invention is to provide a velocity transducer which may be modified to sense either linear or angular velocity. Another object of the present invention is to provide a velocity transducer which senses angular velocity and which is substantially insensitive to linear velocity. Another object of the present invention is to provide a velocity transducer which is operational substantially immediately after application of power. Another object of the present invention is to provide a velocity transducer utilizing AC power input and providing AC signal output with substantially no output phase error referenced to the input over the operating temperature range. Another object of the present invention is to provide a velocity transducer having self test features. Another object of the invention is to provide a velocity transducer which provides inhibited output following electrical failure modes. Additional objects and features of the invention will appear from the following description of which the preferred embodiment has been set forth in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of the velocity transducer. FIG. 2 is an isometric view of the assembled velocity transducer. FIG. 3 is a side elevation sectional view of the velocity transducer. FIG. 4 is a sectional view along the line 4--4 of FIG. 3. FIG. 5 is a sectional view along the line 5--5 of FIG. 3. FIG. 6 is an electrical schematic showing interrelation between the fast automatic null circuit, the output inhibit circuit, the timer circuit, and the self test circuit. FIG. 7 is a self test current diagram. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The improved velocity transducer provides an instrument which is relatively insensitive to errors induced by fluid thermal gradients normally present within floated instruments, adjacent magnetic fields external of the instruments, and shock and vibration environments applied to the instrument outside case. The external configuration of one embodiment of the transducer allows direct replacement of some conventional spinning rotor angular velocity transducers. Referring to FIG. 1, a block diagram of the improved velocity sensor is shown having an accelerometer section 11 for sensing an acceleration input. A rate module 12 receives output from accelerometer section 11 and provides a signal related to velocity to a DC-to-AC signal inverter 13. Rate module 12 has an automatic nulling circuit 14 in a feedback loop around the rate module 12 and a fast automatic null circuit 15 in a parallel feedback loop around rate module 12. An AC to DC power converter 16 receives AC and DC power and is connected to a timer 17 which in this embodiment provides a 2 second output under certain conditions. A fail-passive circuit 18 monitors the output of rate module 12 and under predetermined conditions provides an output to timer 17 which inhibits DC to AC signal inverter 13. A self test circuit 19 is connected to accelerometer module 11 and is controlled externally. FIG. 2 shows the external configuration of the improved velocity transducer having a base member 20 parted along a line 21 forming an upper and lower half 20a and 20b respectively. The lower half 20b of the base member 20 has disposed at each end a bellows 22 which provides for expansion of the internally contained fluid over the operating temperature range. The lower base member 20b also has electrical terminals 23 isolated from the base member 20 and externally accessible on one end for providing electrical power to circuits contained inside base member 20. Holes 24a are shown formed at each of the four corners of the upper base member 20a which provides for clearance of screws (not shown) which enter threaded holes 24b in the lower base member 20b for securing the upper and lower halvesof base member 20 together. A fill plug 25 is disposed in a fill hole 26 located in the top of upper base member 20a. Fill plug 25 is safety wired in place following fluid filling by placing wires (not shown) through holes 27 formed in the walls of a pair of cutouts 28 in upper base members 20a. One configuration of a mounting member 29 is shown in FIG. 2 having mounting holes 30. Clearance holes 31 in mounting member 29 overlie threaded holes 32 in lower base member 20b for receiving screws (not shown) for fastening mounting member 29 to base member 20. Mounting member 29 has additional clearance holes 33 for allowing electrical terminals 23 to pass for connection with an electronics package 34. Mutually perpendicular axes X, Y and Z are shown indexed to the mounting member 29. For description of the internal configuration of the improved velocity sensor, reference is made to FIG. 3. The upper and lower halves 20a and 20b of the base member 20 are shown joined together by screws 35 passing through holes 24a to engage threads in threaded holes 24b in the lower base member 20b. An O-ring 36 is disposed in an O-ring groove 37 formed in upper base member 20a at the surface in juxtaposition with the lower base member 20b. Chambers 38 are formed at either end of lower base member 20b to sealably receive bellows 22. A path 39 connects the two chambers 38 and holes 40 extend from chambers 38 to the surface of lower base member 20 in juxtaposition with upper base member 20a. The fill plug 25 is held in place by safety wire 41 which is shown disposed in holes 27. A fluid mass 42 is disposed at the inner surfaces of bellows 22, completely filling all interior volume defined between upper and lower base members 20a and 20b. A paddle assembly shown generally at 43 is contained in a seismic cradle assembly 47 which is mounted in a bore 44 formed in a boss 45 on the surface of lower base member 20b adjacent to upper base member 20a. Screws 46 retain the seismic cradle assembly 47 in bore 44. An upper and lower pivot and jewel bearing assembly 48 and 49 respectively supports paddle assembly 43 in the seismic cradle 47. The paddle assembly 43 contains the moving and restoring system which includes a paddle member 50 and a rectangular moving coil 51 that forms a part of a torque motor 52 for applying a restoring torque directly to the paddle member 50. The moving coil 51 is disposed in an air gap formed between a magnet 53 and a cylindrical soft iron shell 54 completely surrounding rectangular moving coil 51 and having internally projecting pole pieces 55. The jewels in the upper and lower pivot and jewel bearing assemblies 48 and 49 are mounted on a leaf spring 56, as best shown in FIG. 5, which is fastened to seismic cradle assembly 47 in a cantilevered fashion by means of screws 57. A coil spring 58 backs up each leaf spring 56 and bears against the back up screw 59 disposed in threaded holes 60 in seismic cradle assembly 47. The pivots in the upper and lower pivot and jewel bearing assemblies 48 and 49 are attached to the paddle assembly. Upper and lower hairsprings 61 are provided at each end of paddle assembly 43 to provide for power connection to the moving coil 51. Balance weights 62 may be applied to the moving coil 51 until paddle assembly 43 is substantially insensitive to linear accelerations in any direction. Balance weights 62 are only utilized in the angular velocity transducer as will be hereinafter explained. Electrical conductors connect hair springs 61 to terminal 63 at the top of seismic cradle assembly 47. Additional electrical conductors 64 connect terminal 63 to terminals 23 mounted in base member 20. As best seen in FIG. 4 a continuous passageway 66 is formed by internal walls 67 in upper base member 20a and by boss 45 on lower base member 20b. Paddle members 50 extend through slots 68 in boss 45 into passageway 66. Means is provided for sensing the position of the paddle member 50 about the pivot axis and consists of a pick off coil 69 carried by a mounting block 71 disposed in a hole 72 in boss 45. Mounting block 71 is secured in holes 72 by means of a set screw 73. A second hole 74 in boss 45 may mount a dummy pick off block 76 or an additional pick off block 71 carrying a second pick off coil 69. In some applications it may be advantageous to have the second pick off coil 69 mounted in a hole similar to holes 72 or 74 on the opposite side of boss 45 and spaced from the opposite paddle 50. In either event block 71 or 76 is secured in hole 74 by an additional set screw 73. Electronics module 34 and mounting member 29 are shown mounted in the configuration of FIG. 2. The electronic module 34 may also contain electrical means for receiving AC power input, providing DC power for the transducers, and for receiving the transducer DC output for converting it into an AC output substantially in phase with the AC power input over the operating temperature range. Referring to FIG. 6 certain specific features of the electrical circuitry contained in module 34 and base member 20 will now be described. The acceleration sensing module 11 provides a signal related to acceleration which is connected to a load R L . A self-test circuit 77 having an externally accessible terminal 78 is connected to the load R L . The self-test circuit includes a capacitor C1 connected in series with a resistor R1 which is connected to the output side of R L . A resistor R2 is connected between terminal 78 and external system common. The output of the acceleration module is also sent to the input of the rate module 12. Pertinent portions of the rate module circuit are shown which includes an integrator 79 having parallel feedback paths containing R12 and C2. The output of integrator 79 provides a signal related to velocity which may be sent to a filter 81 contained in electronics package 34. The output from integrator 79 has a pass band limited at the high frequency end by the mechanical response of acceleration module 11 and the electrical characteristics of the module output circuitry. The pass band is limited at the low frequency end by the electrical characteristics of the integrator 79. A timer 82 is included which is connected through a resistor R8 to the gate of a chopper field effect transistor Q1. A transistor Q2 has a bias resistor R6 between emitter and base and a resistor R7 from the base through capacitor C4 to the negative supply voltage -V. A resistor R11 is connected from the collector of Q2 to the negative supply -V. Voltage is placed on the emitter of Q2 at turn on. A fast automatic null circuit 83 receives the output from timer circuit 82. A resistor R3 is in an automatic nulling feedback loop shown at 85. A pair of field effect transistors (FET) Q3 and Q4 have their sources and drains connected across integrator feedback capacitor C2 and the resistor R3, respectively. The output from timer circuit 82 is connected through resistor R4 and R5 to the gates of FET's Q3 and Q4. Capacitor C5 is located between R4 and R5. R13 ensures that Q3 transistor is normally off. A fail passive circuit 84 is a four leg bridge having a diode D1 through D4 in each leg. The velocity signal from integrator 79 is connected to one terminal of the bridge and the opposite side is at signal ground. The intermediate bridge terminals have a light emitting diode connected therebetween in series with a Zener diode D5, such light emitting diode acting as a light source for photo transistor Q5. Turning to the operation of the velocity transducer, the angular velocity sensor will be functionally described. The angular velocity transducer is sensitive about the Y axis of FIG. 2. Sensitivity about this axis relative to the base member 20 provides an angular velocity sensor, or rate sensor, which is interchangeable with spinning rotor type rate gyros now in service in a wide variety of applications. With initial angular velocity about the Y axis serving as a zero reference a change in angular velocity may only occur in the presence of an angular acceleration by definition. The Y axis in FIG. 2 is parallel to the axis of rotation of the fluid mass 42 in the continuous passageway, or annular flow path 66. When the base member 20 is subjected to angular acceleration about the sensitive Y axis, a positive error signal is generated by the accelerometer as the fluid rotor 42, due to its inertia, tends to lag behind the accelerating base member 20. The paddle member 50 disposed in the annular passageway 66 serves to constrain the fluid mass 42 and to cause it to move with the base member 20. As soon as the fluid mass 42 causes slight movement of the paddle member 50 the movement is sensed by pick off coil 69, as explained in copending patent application for "Bias and Scale Factor Temperature Compensation Network", Ser. No. 307,109 filed Nov. 16, 1972. The variation in spacing between the paddle member 50 and the pick off coil 69 modulates the output amplitude which is detected and changed to a high level signal. A signal is supplied to the moving coil 51 to restore the paddle member 50 to its zero or null position, thus causing the fluid mass 42 to move in synchronism with the base member 20. The electrical current flowing into the moving coil 51 is thereby related to the acceleration to which the fluid mass 42 is subjected. Thus, the fluid mass 42 serves as the inertial mass in the accelerometer and is closely coupled to the low inertia torque motor 52. Torque motor 52 operates in a closed-loop fashion to sense the angular motion of the fluid mass 42 and to provide the torque necessary to constrain the mass 42 to move with the base member 20. The torque motor 52 has a centrally disposed magnet 53 and an air gap for the moving coil 51 formed between the magnet 53 and the soft iron cylindrical shell 54 which completely surrounds magnet 53 and moving coil 51. The cylindrical shell 54 has inwardly extending pole pieces 55 to create as narrow an air gap as possible between them and magnet 53. The remainder of cylindrical shell 54 functions as a return flux path for the torque motor 52 and also serves to shield torque motor 52 from any noise signals which might be generated within the moving coil 51 by stray lines of flux from external magnetic fields. Leaf springs 56, as best seen in FIG. 5, provide some compliance for the paddle assembly 43 along the Y axis. Coil springs 58 and back up screws 59 provide a preload adjustment for the upper and lower pivot and jewel bearing assemblies 48 and 49. Leaf springs 56 stabilize the pivots and jewels, minimizing disturbance from shock and vibration to which the base member 20 is subjected. Balance weights 62 on moving coil 51 are installed while the paddle member 50 is mounted within seismic cradle assembly 47 and after pivot and jewel assemblies 48 and 49 have been finally adjusted. Balance of the paddle member 50 within the fluid mass 42 reduces sensitivity to linear acceleration to a low level heretofore not obtainable. The continuous passageway or annular flow path 66 is formed of walls 67 within the upper and lower base member 20a and 20b. Base members 20a and 20b are relatively massive parts and provide for ready heat conduction from any portion of the base member 20 to all other portions. Thus, the walls 67 of the annular flow path 66 are substantially the same temperature at any point. Since there is substantially no temperature differential internally of the base member 20, no temperature gradient can exist within the fluid mass 42 which is in direct contact with base member 20. There are no thermal currents set up within fluid mass 42 which would tend to cause motion of paddle member 50. Therefore, the output signal is substantially free of errors induced by thermal currents within the fluid mass 42. Moreover, paddle members 50 are completely contained within the walls of annular path 66 and are therefore subject only to motion of the fluid mass 42 within the path 66. Electronics package 34 contains AC to DC power converter 16 receiving AC input power. The AC power input is converted by conventional means to DC power and supplied to the electronics described above for energizing the pick off coil 69 and torque motor 52. The output related to angular annular rate from rate module 12 is chopped and formed into a sine wave by a conventional circuit providing an output which is synchronized with the AC power input. Therefore, the normal phase shift relative to the input phase experienced in the normal AC pick off device is substantially eliminated. Change in phase shift as a function of operating temperature over wide temperature ranges is also substantially eliminated. By way of example such phase shift stability has been maintained over the range of -50°C to +90°C. The magnitude of phase shift compensation is limited only by the quality and type of passive components used; e.g. using metal film resistors with low temperature coefficients gives improved performance if they replace carbon resistors with high temperature coefficients. The circuit of FIG. 6 shows those sections which are necessary to a description of the improved velocity sensor disclosed herein. At the time power is turned on to the velocity transducer, voltages +V and -V are placed on the emitter and collector, respectively, of transistor Q2 in timer circuit 82. Fast automatic true null is obtained as follows: capacitor C4 charges through resistors R6 and R7 providing a bias voltage low enough at the base of Q2 to cause conduction thorugh Q2 and R11 to -V. This places +V at the collector of Q2 which is connected to the gates of Q3 and Q4 in fast auto null circuit 83 causing them to conduct. C2 and R3 introduce relatively long time constants in integration performed by integrator 79 and automatic nulling performed by feedback loop 85. C2 and R3 are thereby short circuited for the time determined by circuit 82 which removes the time delay components C2 and R3 long enough for the circuit to quickly null out DC signals at the output of integrator 79. Q3 is turned on through the differentiating coupling network C5, R4 and R13 for a short time, typically 0.2 seconds. The timer circuit 82 is typically set to provide a 2 second conduction at Q2 by choosing R6, R7 and C4 properly, turning on Q4 for a like interval of time. Timer circuit 82 also turns on Q1, simultaneously inhibiting production of an output signal. Means are provided in the integrator for preventing saturation of the integrator output in the absence of velocity applied to the base member. As may be seen from the circuit of FIG. 6, a steady state input to integrator 79 from acceleration module 11 will provide an ever increasing output from integrator 79. The long time constant introduced in the integration simply slows the output signal response resulting from an input signal arriving from acceleration module 11. A low level steady state signal, such as a bias error signal, from acceleration module 11 will provide therefore, a relatively slow response increasing output from integrator 79. This slow response signal may be seen to be fed back through R3 and automatic nulling feedback loop 85 to the other input polarity of integrator 79, thereby cancelling the steady state input signal. Since the auto null feedback loop is also a relatively slow response circuit, as determined by the magnitude of R3, inputs to integrator 69 having frequencies above a predetermined frequency as determined by R3 and C2, will produce output from integrator 79 which will be presented as system output as described above, before the relatively slow response auto null feedback loop 85 is able to produce a cancelling signal. Fail passive circuit 84 monitors the output related to velocity from integrator 79. Any time a signal greater than a predetermined value referenced to signal ground appears at the output of integrator 79, a switch such as photo transistor Q5 is actuated as follows: A voltage at the output of integrator 79 more negative than the sum of the forward voltage drops of D4 and D1 and the Zener voltage of D5 will complete a circuit through the light emitting diode associated with Q5, serving to turn on Q5. An integrator output higher than the sum of the forward voltage drops of D2 and D3 plus the Zener voltage of D5 will also excite the light emitting diode turning on Q5. When Q5 is turned on C4 is shorted and current is drawn through R6, R7 and R10 to -V dropping the base voltage of Q2 to a point to bias Q2 to a conducting condition. The DC voltage +V is placed on the gate of Q1 turning it continuously on. Since the DC output from integrator 79 is no longer chopped by Q1 and the output is transformer coupled, the transducer output is inhibited. The self-test circuit 77 is connected to the top of R L . An external test switch is connected between terminal 78 and a DC test voltage, +28VDC in this embodiment. When the test switch is closed a positive current pulse related to a predetermined acceleration for a predetermined time, as seen in FIG. 7, is directed through the load R L . When the test switch is released a negative current pulse as seen in FIG. 7 is directed through the load R L . The integrator 79 integrates the consequent load voltage change the same as it would an output from acceleration module 11. Thus, a predictable rate or velocity output indicative of normal operation is produced by the transducer having one polarity for closing the external test switch and the opposite polarity for opening the switch. The magnitude of the test velocity output is predetermined by the values of C1, R1 and the test voltage. The angular rate sensor described above may be modified into a linear velocity transducer by rendering the paddle member 50 pendulous. The balancing operation utilizing balancing weights 62 on moving coil 51 is eliminated and a certain degree of pendulosity in paddle assembly 43 is intentionally imposed. Baffling is also installed in continuous passageway 66 to remove the tendency for fluid mass 42 to display inertial properties about the Y axis of FIG. 2 independent of the base member 20. In the linear velocity configuration all components operate as described above with the exception of paddle assembly 43 and the fluid mass 42. In the linear velocity transducer modification, paddle assembly 43 serves as the inertial mass instead of fluid mass 42. Fluid mass 42 serves as a flotation medium and a damping medium only. As shown in FIG. 2, a component of linear velocity along the Z axis is sensed. As described above the linear velocity sensor may function with or without the AC power input and AC signal output circuitry, or the self-test 77, fast auto null 83, timer 82, or fail passive circuit 84. A velocity transducer has been disclosed which is substantially free from errors induced by internal thermal gradients, external magnetic fields, or environmental shock and vibration loads, and which may be used with slight modification to sense angular or linear velocity. Immediate operating capability after turn-on, as well as self test, and fail passive features have been shown.

A velocity sensor which may be modified to perform a sensing function for either angular velocity or linear velocity. The sensor has a base member which is split into upper and lower halves which are shaped to form internal walls defining an internal channel when joined together. A fluid is disposed in the internal channel and a paddle member is placed in communication with the fluid. Sensing means are present to detect the position of the paddle member as it is urged into motion by the inertia of the fluid mass in the angular embodiment and by the inertia of the paddle member in the linear. An electrical output is provided which is related to the urge to move imparted to the paddle member. The output is used to electrically restrain the motion of the paddle member. The output related to paddle member motion is also integrated to provide a signal related to velocity. Saturation of the integrated output unrelated to velocity is prevented by additional electrical means. AC input, DC internal operation, and AC output is provided as well as fast automatic nulling after application of power, self test means and an inhibited output in the event of electrical failure within the unit. The fluid mass flow path being integral with the base member substantially eliminates thermal gradients within the fluid mass, removing error arising from fluid flow due to thermal gradients. Linear acceleration sensitivity in the angular velocity sensor embodiment is eliminated by paddle member balance about the pivot axis within the fluid mass during assembly. Pivot stabilization during shock and vibration loads is provided by adjustable leaf spring supports disposed between the paddle and the base member. The AC output phase shift relative to the AC input is substantially eliminated over the operational temperature range as compared with conventional instruments of this type.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Continuation-In-Part of and claims the benefit of application Ser. No. 29/162,790 filed on Jun. 20, 2002, now U.S. Pat. No. D. 475,193 and incorporates the disclosure of same by reference. BACKGROUND OF THE INVENTION The present invention relates to apparel folding devices. More particularly, the present invention relates to a manually operated device for folding shirts and other articles of apparel in a quick and consistent manner. The device consists of a plurality of panels upon which an unfolded garment may be placed. By successively folding and unfolding the panels in a predetermined pattern, a user may fold the article. In both a commercial and personal setting, it is often desirable to quickly and efficiently fold shirts, for example, in a compact and uniform matter. In the commercial setting, such folding enables employees to quickly set up aesthetically pleasing garment displays. Also, it is well known that shoppers routinely disrupt the uniform appearance of folded garments on display while browsing through stores. It is thus very important for an employee to be able to recompile clothing displays quickly and efficiently, throughout the shopping day. Other commercial settings also call for the quick and efficient folding of shirts. For example, a commercial silk screener may have an order for a number of shirts in which a particular design may be placed. Prior to packaging and delivering the shirts, it is often desirable to fold the shirts in a uniform manner, perhaps even with the silk screened image exposed. Thus, when received by the final customer, a neat and orderly appearance is maintained. In the personal setting, many homemakers are also desirous of folding shirts quickly, efficiently and in a uniform manner. This is especially true where shirts may be placed on shelves, which are visible to the home's occupants and guests, but may also be the case where such shirts are to be placed in a drawer. For large families, the need for efficiency is increased. Various devices have been created to assist with the folding of garments in a quick, efficient and uniform manner. Despite these devices, there remains a need for a simple, inexpensive and efficient apparel folding device. There also remains a need for an apparel folding device that may be shipped in a compact manner. SUMMARY OF THE INVENTION The present invention addresses these needs. One embodiment of the apparel folding device of the present invention comprises a panel having first and second side edges, a first side panel hingedly engaged with the panel along its first side edge, and a second side panel hingedly engaged with the panel along its second side edge. At least one of the first side panel and the second side panel includes a handle member, such as a lipped handle, that extends above the surface of the respective side panels. An article of apparel may be folded using the apparel folding device by placing the article of apparel on the device and successively flipping and unflipping the first side panel and second side panel. The apparel folding device may also comprise first and second end edges with a bottom panel hingedly engaged to the panel along its second end edge. If so provided, at least one of the bottom panel, the first side panel, and the second side panel may include a handle member that extends above the surface of the respective panel. An article of apparel may be folded using the apparel folding device by placing the article on the device and successively flipping and unflipping the first side panel, said second side panel and bottom panel. The bottom panel may include a handle member that extends above the surface of the bottom panel. If so provided, at least one of the first side panel and the second side panel may include a cut out adapted to permit the handle member of the bottom panel to protrude therefrom when the respective side panel is folded. The first side panel may comprise a first upper side panel and a first lower side panel and a second side panel may comprise a second upper side panel and a second lower side panel. The first upper side panel may be capable of being connected to the first lower side panel and the second upper side panel may be capable of being connected to the second lower side panel. The first upper side panel may also be detached from the first lower side panel and the second upper side panel may also be detached from the second lower side panel. The first side panel may also comprise a first upper side panel and a first lower side panel and the second side panel may comprise a second upper side panel and a second lower side panel where the first upper side panel is hingedly engaged with the first lower side panel and the second upper side panel is hingedly engaged with the second lower side panel. The first upper side panel may include a raised plateau forming a plurality of voids and the first lower side panel may include a plurality of self-locking protrusions extending therefrom. The self-locking protrusions may engage the voids to firmly attach the first upper side panel to the first lower side panel. The self-locking protrusions may include a first extension and a second extension. The first extension may comprise an elongated first extension first section adjacent to the first lower side panel at its proximal end and a first under cut at its distal end. The first extension and second extension may be separated by a gap. The raised plateau may be placed above the first lower side panel in engagement with the self-locking protrusions such that the voids are located completely below the under cuts. As previously stated, the first side panel may comprise a first upper side panel and a first lower side panel and the second side panel may comprise a second upper side panel and second lower side panel. The first upper side panel may be hingedly engaged with the first lower side panel and the second upper side panel may be hingedly engaged with the second lower side panel. At least one of the panel, first side panel or second side panel of the apparel folding device may include a display surface. If so provided, the bottom panel may also include a display surface. The first side panel and the second side panel may form apertures therein. If so provided, the bottom panel may also form apertures therein. In another embodiment, an apparel folding device comprises a panel having first and second side edges, a first side panel hingedly engaged with the panel along the first side edge, and a second side panel hingedly engaged with the panel along the second side edge. The first side panel may comprise a first upper side panel and a first lower side panel and the second side panel may comprise a second upper side panel and a second lower side panel. The first upper side panel and the first lower side panel may be capable of being stacked on one another to form a first stack and the second upper side panel and second lower side panel may be capable of being stacked on one another to form a second stack. The first stack and second stack may be capable of being placed on the panel to facilitate shipping and storage of the apparel folding device. The first upper side panel and first lower side panel may be hingedly engaged to each other at all times. Similarly, the second upper side panel and second lower side panel may be hingedly engaged to each other at all times. In other embodiments, the first upper side panel may be separated from the first lower side panel and the second upper side panel may be separated from the second lower side panel. The panel of the apparel folding device of this embodiment may also comprise first and second end edges. There may also be provided a bottom panel hingedly engaged with the panel along the second side edge. If so provided, the bottom panel may be capable of being placed upon the panel to facilitate shipping and storage of the apparel folding device. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of an apparel folding device in accordance with the first embodiment of the present invention. FIG. 2 is an enlarged side elevational view of a self locking protrusion of the present invention; FIG. 3 is a top perspective view of an apparel folding device in accordance with the second embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the following is described the embodiments of the apparel folding device of the present invention. In describing the embodiments illustrated in the drawings, specific terminology will be used for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. In this context, the apparel folding device may be constructed of any relatively rigid material such as various plastics, metals, woods, or the like. For purposes of this application, however, the apparel folding device will be referred to as if constructed of plastic. Similarly, many types of garments may be folded using this device. However, this application will generally refer to shirts. Yet, it is to be understood that this device may be used to fold sweaters, pants, shorts and scarves, among other garments. Finally, it is to be understood that although the invention is hereinafter described with two-part hinges, many hinges may be utilized. For example, depending on the panel material, living hinges may be utilized. Such hinges are commonly known in the industry. They are generally created by the placement of a thin portion of material bridging two heavier portions of the same material. They provide the ability to flex repeatedly without the use of a mechanical hinge. Other hinges contemplated include butt hinges, slip hinges, continuous hinges, flag hinges, liftoff hinges, and many other hinges generally known in the industry. Preferably, the hinges are detachable to facilitate shipping of the apparel folding device. Referring to the figures, FIG. 1 depicts an exploded perspective view of an apparel folding device in accordance with the first embodiment of the present invention. The apparel folding device 2 preferably comprises a first panel 4 , bottom panel 6 , and first 8 and second 10 opposing side panels. The first panel 4 comprises a continuous edge 12 . The continuous edge 12 comprises a first edge 14 and an opposing second edge 16 . A third edge 18 and opposing fourth edge 20 are oriented transverse to the first and second edges 14 , 16 of the first panel 4 . The first edge 14 is adjacent to the first side panel 8 , the fourth edge 20 is adjacent to the bottom panel 6 , and the second edge 16 is adjacent to the second side panel 10 . On each of the first edge 14 , fourth edge 20 , and second edge 16 , there is preferably located a pair of receiving hinges 21 A through 21 F. More particularly, receiving hinges 21 A and 21 B are located on first edge 14 , receiving hinges 21 C and 21 D are located on fourth edge 20 , and receiving hinges 21 E and 21 F are located on second edge 16 . As will be described hereinafter, the receiving hinges mate with hinged members of the other panels to permit rotation of these other panels relative to the respective edges of the first panel 4 . It will also be appreciated that a single hinge of the types previously discussed, particularly living hinges, may be used. First panel 4 may also preferably contain a series of apertures 22 extending therethrough. The apertures 22 provide weight and material savings while still permitting the panel to have sufficient rigidity for its intended purpose. In addition, the apertures 22 facilitate the folding of apparel when the apparel folding device is in use by permitting air to flow therethrough. This air penetration prevents garments (not shown) from adhering to the panel 4 as it is unfolded. Although shown as slots, the apertures 22 may be in the form of virtually any shape including circles, squares, stars, and the like. The apertures may be dispersed in a uniform pattern, as shown in the figures, or may be randomly dispersed. First panel 4 also may preferably comprise a display surface 24 . The display surface may be utilized to display any number of graphical images, but is typically utilized to display the name of the apparel folding device product 2 and information regarding the manufacturer. Rotatably engaged along the fourth edge 20 of first panel 4 is bottom panel 6 . Bottom panel 6 comprises a first edge 26 and an opposed second edge 28 . Third edge 30 and opposed fourth edge 32 are oriented transverse to the first 26 and second 38 edges. The third edge 30 , located adjacent to the fourth edge 20 of first panel 4 , contains a pair of hinged members 34 A and 34 B which rotatably engage receiving hinges 21 C and 21 D of first panel 4 . This rotatable engagement permits bottom panel 6 to rotate relative to fourth edge 20 of first panel 4 , when so desired. Along the fourth edge 32 of bottom panel 6 is preferably located lipped handle 36 . The lipped handle 36 is a crescent shaped member, which rises from the surface of bottom panel 6 . The lipped handle 36 is designed to enable a user to easily grasp bottom panel 6 to facilitate rotation of same. By providing such a raised handle 36 , bottom panel 6 may lie completely flat against a work surface (not shown), yet still permit a user to easily grasp it of course, feet capable of lifting the panel 6 may also be provided. As with first panel 4 , bottom panel 6 also comprises a series of apertures 38 and a display surface 39 . The apertures 38 are typically identical to the apertures 22 of first panel 4 , although they need not be. Further, the display surface 39 of bottom panel 6 is typically similar to the display surface 24 of first panel 4 . However, this display surface 39 generally includes graphically illustrated instructions designed to teach a user how to use the apparel folding device 2 . As shown in FIG. 1, adjacent to the first edge 14 of first panel 4 is located first 'side panel 8 . In the first, and preferred embodiment of the present invention, side panel 8 is comprised of a first upper side panel 40 and a first lower side panel 42 . This permits the panel to be shipped as two separate pieces, thus reducing the length of the package required to ship the device. The first upper side panel 40 comprises a first edge 44 located parallel and adjacent to the first edge 14 of first panel 4 . The first upper side panel 40 also comprises a second edge 46 extending perpendicular to the first edge 44 . A third edge 48 extends from the end of the second edge 46 opposite to the first edge 44 along an arcuate path and ends at the opposite end of first edge 44 . Each of the three edges 44 , 46 , 48 combine to form an essentially square first upper side panel 40 . The first lower side panel 42 comprises a first edge 50 located parallel and adjacent to the first edge 26 of bottom panel 6 . The first lower side panel 42 also comprises a second edge 52 extending perpendicular to the first edge 50 , and adjacent to second edge 46 of first upper side panel 40 . A third edge 54 extends from the end of the second edge 52 opposite to the first edge 50 along an arcuate path and ends at the opposite end of first edge 50 . As shown in FIG. 1A, each of the edges 50 , 52 , 54 , combine to form an essentially square first lower side panel 42 . As with the previous panels, first upper side panel 40 and first lower side panel 42 also preferably contain a series of apertures 56 . The apertures 56 are typically identical to the apertures 22 of first panel 4 and 38 of bottom panel 6 , although they need not be. First lower side panel 42 is provided with a lipped handle 58 and an arcuate cutout 60 along its third edge 54 . The lipped handle 58 is typically crescent shaped, similar to lipped handle 36 of bottom panel 6 . In this regard, the lipped handle 36 is designed to enable a user to easily grasp first lower side panel 42 to facilitate rotation of same. By providing such a raised handle 58 , first lower side panel 42 may lie completely flat against a work surface (not shown) of course, feet may also be provided. The arcuate cutout 60 is preferably provided in first lower side panel 42 so that when the panel 42 is rotated towards first panel 4 and bottom panel 6 , lipped handle 36 of bottom panel 6 may protrude therethrough. This enables first side panel 8 to lie completely flat against first panel 4 and bottom panel 6 , when in a folded condition. As is show in FIG. 1, the second edge 46 of first upper side panel 40 is raised from the third edge 48 and the first edge 44 . The second edge 46 is raised a distance equal to the thickness of first lower side panel 42 , and results in the formation of a raised plateau 61 extending from second edge 46 . Plateau 61 contains a plurality of circular apertures 62 . Along second edge 52 of first lower side panel 42 are disposed a plurality of self locking protrusions 64 . Each self locking protrusion 64 is aligned with an aperture 62 on plateau 61 . First upper side panel 40 may be connected to first lower side panel 42 by placing the protrusions 64 of the first lower side panel through the circular apertures 62 of the first upper side panel 40 . Such placement will lock the two panels 40 , 42 together. It will be appreciated that when the panels 42 , 44 are connected, the apparel folding device 2 lays completely flat against a work surface (not shown), when in its open condition, unless feet are provided. FIG. 2 depicts a detailed illustration of a self locking protrusion 64 . Each self locking protrusions 64 preferably consists of two extensions 66 extending normal to the upper surface of first lower side panel 42 . Each extension preferably begins with a first section 68 extending from the first lower side panel 42 and ends with a second section 70 . The second section 70 contains an undercut 72 . Between each extension 66 lies a gap 74 . In order to connect first upper panel 40 to first lower side panel 42 , the circular apertures 62 are placed above the self locking protrusions 64 . Upon the application of pressure along the plateau 61 of first upper panel 40 , each extension 66 will flex inwards to close gap 74 and the circular apertures will pass over the undercuts 72 to a point adjacent to first section 68 . Once the undercuts 72 are cleared, the extensions 66 will spring back to their natural state and the undercuts 72 will prevent first upper side panel 40 from becoming separated from first lower side panel 42 as the undercuts are of a greater diameter than the apertures 62 when in their natural, unflexed condition. It will be appreciated that to achieve the tightest fit possible, the first section 68 of each self locking protrusion 64 is of a length only slightly greater than the thickness of plateau 61 . Referring back to FIG. 1, the first edge 44 of first upper side panel 40 contains a pair of hinged members 76 A, 76 B. The hinged members 76 A, 76 B of first upper side panel 40 rotatively engage receiving hinges 21 A and 21 B of first panel 4 . This engagement allows first side panel 8 to freely rotate relative the first edge 14 of first panel 4 . Second side panel 10 is constructed in much the same manner as first side panel 8 . However, it will be appreciated that second side panel 10 is located adjacent to second edge 16 of first panel 4 . In the first, and preferred embodiment of the present invention, side panel 10 is comprised of a second upper side panel 80 and second lower side panel 82 . The second upper side panel 80 comprises a first edge 84 located parallel and adjacent to the second edge 16 of first panel 4 . The second upper side panel 80 also comprises a second edge 86 extending perpendicular to the first edge 84 . A third edge 88 extends from the end of the second edge 86 opposite to the first edge 84 along an arcuate path and ends at the opposite of first edge 84 . As shown in FIG. 1, each of the three edges 84 , 86 , 88 combined to form an essentially square second upper side panel 80 . The second lower side panel 82 comprises a first edge 90 located parallel and adjacent to the second edge 28 of bottom panel 6 . The second lower side panel 82 also comprises a second edge 92 extending perpendicular to the first edge 90 , and adjacent to the second edge 86 of second upper side panel 80 . A third edge 94 extends from the end of the second edge 92 opposite to the first edge 90 along an arcuate path and ends at the opposite end of first edge 90 . As shown in FIG. 1, each of the edges 90 , 92 , 94 combine to form an essentially square second lower side panel 82 . As with the previous panels, second upper side panel 80 and second lower side panel 82 also contain a series of apertures 96 . The apertures 96 are typically identical to the apertures 22 of first panel 4 , the apertures 38 of bottom panel 6 , and the apertures 56 of first upper side panel 40 and first lower side panel 42 , although they need not be. Second lower side panel 82 is also preferably provided with a lipped handle 98 and an arcuate cutout 100 along its third edge 94 . The lipped handle 98 is typically crescent-shaped, similar to the lipped handle 36 of bottom panel 6 , and the lipped handle 58 of first lower side panel 42 . In this regard, the lipped handle 98 is designed to enable a user to easily grasp second lower side panel 82 to facilitate rotation of same. By providing such a raised handle 98 , second lower side panel 82 may lie completely flat against a work surface (not shown), if feet are not provided. The arcuate cutout 100 is preferably provided in second lower side panel 82 so that when the panel 82 is rotated towards first panel 4 and bottom panel 6 , lipped handle 36 of bottom panel 6 may protrude therethrough. This enables second side panel 10 to lie completely flat against first panel 4 and bottom panel 6 , when in its folded condition. Although the invention has been described as preferably including crescent-shaped lipped handles 36 , 58 , 98 , it will be appreciated that any member which extends beyond the upper surface of the respective panel will suffice. Crescent-shaped lipped handles are merely preferable. As with first upper side panel 40 , in the preferred embodiment, the second edge 86 of second upper side panel 80 is raised from the third edge 88 and the first edge 84 . The second edge 86 is raised a distance equal to the thickness of the lower side panel 82 , and results in the formation of a raised plateau 101 extending from second edge 86 . Plateau 101 contains a plurality of circular apertures 102 . Along second edge 92 of second lower side panel 82 are disposed a plurality of self locking protrusions 104 . Each self locking protrusion is aligned with an aperture 102 on plateau 101 . Second upper side panel 80 may be connected to second lower side panel 82 by placing the protrusions 104 of the second lower side panel through the circular apertures 102 of the second upper side panel 80 , thus locking the two panels 80 , 82 together. It will be appreciated that in the preferred embodiments, when the panels 80 , 82 are connected, the apparel folding device 2 lays completely flat against a work surface (not shown), when in its open condition. Of course, feet may be provided on the bottom of the panels, if so desired. The self locking protrusion 84 of second lower side panel 82 are identical to the self locking protrusions 64 of first lower side panel 42 , as shown in FIG. 2 . The first edge 84 of second upper side panel 80 contains a pair of hinged members 106 A and 106 B. The hinged members 106 A and 106 B of second upper side panel 80 rotatingly engage receiving hinges 21 E and 21 F of first panel 4 . This engagement allows second side panel 10 to freely rotate relative the second edge 16 of first panel 4 . While FIG. 1 depicts a top prospective view of an apparel folding device in accordance with the first embodiment of the present invention, FIG. 3 depicts a prospective view of a folding device in accordance with the second embodiment of the present invention. In this embodiment, first side panel 8 and second side panel 10 are each formed from a single sheet of material. Typically, this is a result of a single monolithic pour of material. As with the previous embodiment, the apparel folding device of the second embodiment lays completely flat when in its opened condition, unless feet are provided. The preferred embodiment has the advantage of being shipped in a more compact manner than the second embodiment. For example, in the preferred embodiment, the apparel folding device 2 may be shipped in a box (not shown) which is substantially the same size as first panel 4 . In this regard, first upper side panel 40 and first lower side panel 42 will either not be connected to each other, or will be folded along second edge 46 of first upper side panel 40 and second edge 52 of first lower side panel 42 . Likewise, second upper side panel 80 and second lower side panel 82 will either be shipped apart from each other, or will be folded together along second edge 86 of second upper side panel 80 and second edge 92 of second lower side panel 82 . The four side panels 40 , 42 , 80 , 82 may then be placed upon first panel 4 in a stacked configuration. Finally, bottom panel 6 may be similarly placed on the stack. It will be appreciated that this stack may then be placed in a box (not shown) which is not substantially larger than first panel 4 . In the second embodiment, the apparel folding device 2 must be shipped in a larger box. This box will be approximately the same size as first side panel 8 and first side panel 10 , as these side panels are not separable. In a third embodiment, the apparel folding device 2 may only comprise three panels, namely, first panel 4 , first side panel 8 and second side panel 10 . It will be appreciated that the remaining aspects of each of these panels may coincide with those found in the first and second embodiments. In this regard, first side panel 8 may comprise first upper side panel 40 and first lower side panel 42 , as in the first embodiment, or may be a single panel as in the second embodiment. Similarly, second side panel 10 may comprise second upper side panel 80 and second lower side panel 82 , as in the first embodiment, or may be a single panel as in the second embodiment. To use the apparel folding device 2 , a user should place the garment, for example a shirt (not shown), on the unfolded device. After centering the garment (not shown), the user may successively fold and unfold each side panel 8 , 10 , and then the bottom panel 6 (if provided). This will result in the garment (not shown) being folded. It will be appreciated that to facilitate a user grasping the panels 6 (if provided), 8 , 10 , each is provided with a lipped handle 36 , 58 , 98 . Apertures 38 , 56 , 96 may also be provided to permit air to flow through the panels 6 (if provided), 8 , 10 . This prevents the garment from adhering to the panels 6 (if provided), 8 , 10 as they are being unfolded. Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.

An apparel folding device suitable for folding apparel in a quick and consistent manner is disclosed. The device comprises a first panel hingedly connected to two side panels located on opposing sides. A bottom panel hingedly connected to the first panel may also be provided between the two side panels. The bottom panel and two side panels may each include a lipped handle. In addition, each of the two side panels may be constructed from two sub-panels. This permits the device to be shipped in a more compact and smaller package. The entire apparatus lays flat against a work surface when in its unfolded condition. The bottom panel and two side panels may include a raised member to facilitate grasping of the panel. By manipulating the panels in a predetermined order, apparel may be folded.

FIELD OF THE INVENTION This invention relates to a process for removing flow-restricting material from a wellbore in a subterranean formation which has been treated with a particulate material coated with a curable phenolic resin. BACKGROUND OF THE INVENTION Subterranean formations surrounding oil wells, gas wells, water wells and other similar bore holes, are frequently treated with particulate material such as sand which has been coated with a curable phenolic resin. The type of treatments vary but can include hydraulic fracturing, sand consolidation, and gravel pack completion. In these treatments the coated particulate material is injected into the well and into the geological formation surrounding the bore hole. The curable phenolic resin coating on the particulate material is cured in the formation to bond the particulate material together. This gives a permeable filter which prevents small sand particles and other finely divided material from blocking the perforations in the well casings and from damaging the pumping and other handling equipment. Occasionally an excess of the resin coated particulate material is pumped down into the well and fills the wellbore above the perforations in the well casing. If the resin coating on the particulate material cures within the wellbore, it firms a consolidated mass which drastically impedes the flow of liquid from the well. When the occurs, it is often necessary to employ a special boring rig to remove the consolidated material to obtain satisfactory production from the well. Such a procedure is both time-consuming and expensive. We have now discovered that certain solvents will break up the consolidated material permitting its removal from the wellbore without the need to resort to the costly boring procedure. SUMMARY OF THE INVENTION In accordance with this invention there is provided a process for removing from a wellbore in a subterranean formation particulate material which has been bonded together by a cured phenolic resin. This process comprises contacting the bonded particulate material with a solvent composition containing a liquid selected from the group N,N-dimethylformamide, N-methyl-2-pyrrolidone, and mixtures thereof for a sufficient time to break up the particulate material. The separated material is then removed from the wellbore. DETAILED DESCRIPTION OF THE INVENTION As mentioned previously, wells are frequently treated with particulate material coated with a curable phenolic resin. The particulate materials used for this purpose include, for example, sand, sintered bauxite, zircon and glass beads. The curable phenolic resins used to coat the particulate material are either novolak or resole resins. As is well known in the art, the resole resins can cure and harden by heat alone. On the other hand, the novolak resins require the presence of a curing agent such as hexamethylenetetramine to make them heat curable. When an excess of the resin coated material is pumped down the well it may fill the wellbore to a level above the perforations in the well casing. This is known in the industry as a screenout. When a screenout occurs, the flow rate from the well is greatly reduced. If the resin coating on the particulate material has not yet cured it is sometimes possible to remove the excess material from the wellbore by means of a water jet. However, the resin coating on the particulate material may cure due to the elevated temperature in the well. In the curing process, resin coating one particle cross-links with resin coating adjacent particles thereby binding the particulate material into a flow-restricting, consolidated mass. When this occurs it is almost impossible to remove this flow-restricting material by a water jet. It has been necessary to resort to an expensive drilling to open up the wellbore. In the practice of the present invention a solvent composition is used to dissolve part of the cured resin which binds the particulate material together. Enough of the resin is dissolved to cause the solid mass to disintegrate. The loosened particulate material can then be pumped from the well. Most of the common solvents are unsuitable for this purpose. The present invention is based on the discovery that two liquids, N,N-dimethylformamide and N-methyl-2-pyrrolidone, are capable of breaking up the solid mass. The solvent compositions used in the practice of this invention can be the foregoing liquids without dilution (neat) or the liquids can be diluted with from about 1% to about 40% by volume of a diluent. Various diluents, including water, may be used for this purpose. In carrying out the process of this invention, the solvent composition is pumped into the well to contact the material which has been bonded together with the cured phenolic resin. The solvent composition is maintained in contact with the flow-inhibiting material for a sufficient time to cause this material to soften or break up and become flowable. The mixture of solvent and flowable material is then displaced from the well by means of water or other displacingfluid. The solvent compositions used in the practice of this invention are most effective when they are maintained in contact with the flow-inhibiting material at temperatures of from about 40° C. to about 150° C. Such temperatures are usually present in the subterranean formation where this invention is practiced. In certain applications it may be desirable to warm the solvent composition before it is placed in the well. The following examples illustrate the invention. It is to be understood that the examples are illustrated only and are not intended to limit the invention in any way. In the examples all parts and percentages are by weight unless otherwise indicated. EXAMPLE 1 A slurry of resin coated sand in 2% aqueous KCl solution was packed in polypropylene tubing, sealed and heated at 93° C. for 24 hours. This caused the resin coating to cure, bonding together the sand particles to form a slug of about 0.64×5 cm. The resin coated sand was ACFRAC CR 20/40, a sand coated with a curable phenolic resin available from the Acme Resin Corporation, Westchester, Ill. Slugs composed of sand bonded together by the cured resin coated sand were contacted with N-methyl-2-pyrrolidone at various temperatures and the time at which disintegration of the slug occurred was noted. The experiments were repeated using N-methyl-2-pyrrolidone diluted with varying amounts of water. The results given in Table I demonstrate that N-methyl-2-pyrrolidone is capable of separating the bonded sand particles even when the solvent is diluted with water. TABLE I______________________________________EFFECT OF N--METHYL-2-PYRROLIDONE (MPD) ONSAND PARTICLES BONDED WITH A PHENOLIC RESIN ContactSolvent Temp. (°C.) Time (hrs) Results______________________________________MPD (neat) 21 48 No Apparent Effect 66 3 Slug Disintegrated 93 1 Slug DisintegratedMPD/H.sub.2 O 21 72 Slug Disintegrated75/25 (vol) 66 3 Slug Disintegrated 93 2 Slug DisintegratedMPD/H.sub.2 O 21 48 No Apparent Effect50/50 (vol) 93 48 No Apparent Effect______________________________________ EXAMPLE 2 The general procedure of Example 1 was followed except that N,N-dimethylformamide was used instead of N-methyl-2-pyrrolidone. The results given in Table II show that this solvent, either neat or diluted with water, is effective in separating the bonded sand particles. TABLE II______________________________________EFFECT OF N,N--DIMETHYLFORMAMIDE (DMF) ONSAND PARTICLES BONDED WITH A PHENOLIC RESIN ContactSolvent Temp. (°C.) Time (hrs) Results______________________________________DMF (neat) 21 16 Slug Softened 66 1 Slug Disintegrated 93 1 Slug DisintegratedDMF/H.sub.2 O 21 72 Slug Softened75/25 (vol) 66 4 Slug Disintegrated 93 1 Slug DisintegratedDMF/H.sub.2 O 21 48 No Apparent Effect50/50 (vol) 93 48 No Apparent Effect______________________________________ Thus it is apparent that there has been provided, in accordance with the invention, a process for removing flow-restricting material from a wellbore in a subterranean formation that fully satisfies the objective, aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to include all such alternatives, modifications, and variations as set forth within the spirit and scope of the appended claims.

An improved process for removing from a wellbore in a subterranean formation particulate material bonded together by a cured phenolic resin. The material is contacted with a solvent composition comprising a liquid selected from the groups: N,N-dimethylformamide, N-methyl-2-pyrrolidone and mixtures thereof for a sufficient time to separate the particulate material and then the separated material is removed from the wellbore.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a National Stage Application of PCT/US2008/000162 filed Jan. 3, 2008 under 35 USC §371(a), which claims priority of U.S. Provisional Patent Application Ser. No. 60/878,484 filed Jan. 3, 2007 the entire contents of which are hereby incorporated by reference. BACKGROUND 1. Field of the Disclosure The present disclosure generally relates to surgical instruments for performing laparoscopic and endoscopic surgical procedures, and, more particularly, relates to a surgical trocar incorporating a novel magnetically active component for facilitating alignment and insertion of magnetically responsive surgical instruments during use in a surgical environment. 2. Description of the Related Art In laparoscopic and endoscopic surgical procedures, a small incision or puncture is made in the patient's body to provide access for a surgical system which is inserted into the patient's body to permit viewing of the surgical site or for the insertion of instruments used in performing the surgical procedure. The surgical system may be in the form of a trocar cannula assembly incorporating an outer cannula and an obturator which is positioned in the outer cannula. The obturator includes a sharpened point or tip which is used create a path to the surgical site. The obturator is then removed leaving the cannula in place to maintain access to the surgical site. Once the cannula is in place, various surgical instruments such as graspers, scissors, dissectors, retractors or the like, may be inserted by a surgeon to perform the surgery. Typically, these surgical instruments are constructed from ferrous metals such as stainless steel, carbon steel, alloy steel or the like, and, thus, are inherently magnetically responsive. SUMMARY A surgical portal apparatus for receiving medical instrumentation includes a portal member adapted for passage through tissue for providing access to an underlying tissue site, and having a longitudinal opening extending therethrough. The portal member has a magnetic material for creating a magnetic field adapted to urge magnetically responsive instrumentation at least toward the longitudinal opening to permit passage therethrough and use of the instrumentation in performing a medical procedure adjacent the tissue site. The portal member may include a housing and a sleeve extending from the housing with the magnetic material being disposed at least within the housing. The magnetic material may be at least partially disposed within an interior surface of the housing. The interior surface containing the magnetic material may at least partially define the longitudinal opening. The magnetic material may be coaxially arranged about the longitudinal axis. Preferably, the interior surface defines a tapered arrangement relative to the longitudinal axis. Alternatively, the magnetic material is disposed within the sleeve. The portal member may include an electromagnet. The electromagnet may define a coiled arrangement. In another embodiment, a surgical portal apparatus for receiving medical instrumentation includes a portal member adapted for passage through tissue for providing access to an underlying tissue site. The portal member includes a portal housing and a portal sleeve extending distally from the portal housing. The portal sleeve defines a longitudinal axis and has a longitudinal opening extending through the proximal and distal ends. The portal housing is adapted to establish a magnetic field to urge magnetically responsive instrumentation at least toward the longitudinal opening to permit passage therethrough and use of the instrumentation in performing a medical procedure adjacent the tissue site. The portal member also may be adapted to establish a second magnetic field distal of the first magnetic field to facilitate advancement of the instrumentation through the portal member. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiment(s) given below, serve to explain the principles of the disclosure, wherein: said FIG. 1 is a perspective view of a surgical trocar assembly in accordance with the principles of the present disclosure including a cannula and an obturator assembled within the cannula; FIG. 2 is a perspective view of the surgical trocar assembly of FIG. 1 illustrating the cannula and the obturator removed from the cannula; and FIG. 3 is a side cross-sectional view of the cannula of the surgical trocar assembly of FIG. 1 . DETAILED DESCRIPTION The portal apparatus contemplates the introduction and manipulation of various types of instrumentation. Examples of instrumentation include clip appliers, graspers, dissectors, retractors, staplers, laser probes, photographic devices, endoscopes and laparoscopes, tubes and the like. Such instruments will be collectively referred to herein as “instruments or instrumentation”. In many instances, these instruments incorporate ferromagnetic material such as stainless steel and titanium, particularly, within the end effector area, which would inherently cause at least the end effector area of the respective instrument to be attracted to magnetically charged elements. In this regard, and in accordance with the present disclosure, the portal apparatus incorporates a magnetically charged material or portion which may facilitate introduction and/or advancement of the instrument within and through the portal apparatus. In the following description, as is traditional, the term “proximal” refers to the portion of the instrument closest to the operator while the term “distal” refers to the portion of the instrument remote from the operator. Referring now to the drawings, in which like reference numerals identify identical or substantially similar parts throughout the several views, FIGS. 1-2 illustrate the portal apparatus 10 of the present disclosure. Portal apparatus 10 may be in the form of a trocar assembly including cannula assembly 100 and obturator assembly 200 which is positionable within the cannula assembly 100 . For example, in one embodiment, portal apparatus 10 is a laparoscopic trocar assembly particularly adapted for use in laparoscopic surgery where the peritoneal cavity is insulated with a suitable gas, e.g., CO 2 , to raise the cavity wall from the internal organs therein. Specifically, cannula assembly 100 with obturator assembly 200 positioned therein is applied against the body cavity or abdominal wall. Once obturator assembly 200 penetrates through the abdominal wall, the obturator assembly 200 is removed from the cannula assembly 100 to permit introduction of surgical instrumentation through the remaining cannula assembly 100 to perform the procedure. Referring now to FIGS. 1-2 , in conjunction with FIG. 3 , cannula assembly 100 includes cannula sleeve 102 and cannula housing 104 mounted to an end of the sleeve 102 . Any means for mounting cannula sleeve 102 to cannula housing 104 are envisioned including threaded arrangements, bayonet coupling, snap-fit arrangements, adhesives, etc. Cannula sleeve 102 and cannula housing 104 may be integrally formed. Cannula sleeve 102 defines a longitudinal axis “a” extending along the length of sleeve 102 . Sleeve 102 further defines an internal longitudinal passage 106 dimensioned to permit passage of surgical instrumentation. Sleeve 102 defines collar 108 which is mounted to cannula housing 102 and an inner tapered wall 110 adjacent the collar 108 . The sloped configuration of tapered wall 110 may assist in guiding the inserted instrument into longitudinal passage 106 . Sleeve 102 may be formed of stainless steel or other rigid materials such as a polymeric material or the like. Sleeve 102 may be clear or opaque. The diameter of sleeve 102 may vary, but, typically ranges from about 10 mm to about 15 mm. Cannula housing 104 includes port opening 114 and luer fitting 116 positioned within the port opening 114 . Luer fitting 116 is adapted for connection to a supply of insufflation gaseous is conventional in the art and incorporates valve 118 ( FIGS. 1-2 ) to selectively open and close the passage of the luer fitting 116 . Cannula housing 104 further includes duckbill or zero closure valve 120 which tapers distally and inwardly to a sealed configuration. Closure valve 120 defines slit 122 which opens to permit passage of the surgical instrumentation and closes in the absence of the instrumentation. Closure valve 120 is preferably adapted to close upon exposure to the forces exerted by the insufflation gases in the internal cavity. Other zero closure valves are also contemplated including single or multiple slit valve arrangements, trumpet valves, flapper valves, etc. Closure valve 120 rests upon internal shelf 124 of cannula housing 104 when assembled. Obturator assembly 200 includes obturator housing 202 and elongated obturator 204 extending from the obturator housing 202 . Elongated obturator 204 may include penetrating tip 206 dimensioned to pierce, penetrate or incise tissue. Penetrating tip 206 may be bladed, pyramidal in shape or blunt. Portal apparatus 10 may also incorporate seal assembly 300 . Seal assembly 300 may be a separate component from cannula assembly 100 and, accordingly, adapted for releasable connection to the cannula assembly 100 . Alternatively, seal assembly 300 may be incorporated as part of cannula assembly 100 . Seal assembly 300 includes a seal housing, generally identified as reference numeral 302 , and gimbal mount 304 which is disposed within the seal housing 302 . Seal housing 302 houses the sealing components of the assembly and defines the outer valve or seal body of the seal assembly 300 . Seal housing 302 defines central seal housing axis “b” which is preferably parallel to the axis “a” of cannula sleeve 302 and, more specifically, coincident with the axis “a” of the cannula sleeve 302 . Seal housing 302 may incorporate multiple housing components, or may be a single unit. Seal housing 302 defines inner guide wall 308 and outer wall 310 disposed radially outwardly of the inner guide wall 308 . Inner guide wall 308 defines central passage 312 which is dimensioned to receive a surgical instrument and laterally confine the instrument within seal housing 302 . Inner guide wall 308 defines sloped or tapered portion 314 adjacent its proximal end. Sloped portion 314 is obliquely arranged relative to seal housing axis “b” and extends radially inwardly relative to the seal housing axis “b” in the distal direction. Sloped portion 314 assists in guiding the inserted instrument into central passage 312 , particularly, when the instrument is non-aligned or off-axis relative to the seal housing axis “b”, or introduced at an angle relative to the seal housing axis “b”. Sloped portion 314 provides more flexibility to the surgeon by removing the necessity that the instrument be substantially aligned with the seal housing axis “b” upon insertion. Gimbal mount 304 is mounted in a manner to permit angulation and/or rotational movement of the gimbal mount 104 relative to, or about, seal housing axis “b”. Specifically, gimbal mount 304 is free to angulate relative to seal housing axis “b” through a range of motion within seal housing 302 . Further details of gimbal mount 104 may be ascertained by reference to commonly assigned U.S. Patent Publication No. 2006/0224120 to Smith, the entire contents of which are incorporated herein by reference. Referring now to FIG. 3 , the aspects of the ferromagnetic capabilities of trocar assembly 10 and the features provided thereby in guiding and facilitating introduction and passage of instrumentation will be discussed. In one embodiment, seal housing 302 includes magnetically active member 316 adjacent sloped portion 314 to attract a magnetically responsive object such as, for example, the tip of a medical instrument “i.” In one embodiment, magnetically active member 316 is a coiled or annular arrangement disposed on the surface of sloped portion 314 or embedded therewithin, and extending a predetermined distance along the seal axis “b”. The annular arrangement of magnetically active member 316 provides a magnetic force (indicated by arrows 318 ) which is sufficient to urge a magnetically responsive object, such as, for example, the tip of medical instrument “i”, in general alignment with axes “a” and “b”, into central passage 312 and distally along the longitudinal axis “a”. In this manner, a surgeon need only position medical instrument “i” within the proximity of central passage 312 . Thereafter, surgical instrument “i” is aligned via the magnetic forces 318 and advanced through central passage 312 and cannula sleeve 102 . Moreover, the surgeon may advance surgical instrument “i” through cannula assembly 200 with one hand without having to steady cannula assembly 200 with the other hand as is typically necessary to facilitate alignment of instrumentation with the passageway to the surgical site. As a further alternative, cannula assembly 100 may include a second magnetically active member distal of the first mentioned magnetically active member 316 . In one embodiment, collar 108 of cannula sleeve 102 incorporates magnetically active member 112 disposed on the surface or embedded within the collar 108 . Magnetically active member 112 defines a magnetic field creating a magnetic force (as indicated by directional arrows 115 ) along the longitudinal axis “a” in a general distal direction. This magnetic field assists in attracting and passing the instrument “i” along the longitudinal axis “b” through sleeve 102 and also into central alignment with the longitudinal axis “a”. It is envisioned that magnetically active member 112 may be embedded within cannula housing 104 . Magnetically active members 112 , 316 may incorporate any magnetic material suitable for the intended purpose of attracting a ferromagnetic material of the instrument “i” as appreciated by one skilled in the art. Magnetically active members 112 , 316 may be in the form of a permanent magnet or may be an electromagnet. In the embodiment incorporating an electromagnetic, an electromagnetic generator 400 is provided and in electrical communication with the magnetically active members 112 , 316 to create the respective magnetic field on demand. In use, an instrument is positioned adjacent the portal apparatus 10 and advanced through cannula sleeve 102 as facilitated by either or both magnetically active members 112 , 316 as discussed hereinabove. The instrument “i” may be used to perform a desired procedure. When the instrument “i” is not in use, the clinician may, in one embodiment, release the instrument “i”. The released instrument “i” may remain unattended within cannula sleeve 102 , i.e., be retained with the cannula sleeve 102 , through the created magnetic fields. It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

A surgical portal apparatus for receiving medical instrumentation includes a portal member adapted for passage through tissue for providing access to an underlying tissue site, and having a longitudinal opening extending therethrough. The portal member has a magnetic material for creating a magnetic field adapted to urge magnetically responsive instrumentation at least toward the longitudinal opening to permit passage therethrough and use of the instrumentation in performing a medical procedure adjacent the tissue site.

The present invention is a continuation-in-part application of U.S. patent application Ser. No. 259,230, filed Apr. 30, 1981 in the name of Robert A. Young abandoned which is a continuation-in-part application of U.S. patent application Ser. No. 238,275, filed Feb. 25, 1981 now U.S. Pat. No. 4,377,749 which relates generally to a photoionizer and more specifically to a photoionization detector of trace species which uses a sealed light source in the detector and a photoionization source for a mass spectrometer which uses the same light source. BACKGROUND OF THE INVENTION The use of sealed light sources for various purposes is discussed and illustrated in U.S. Pat. Nos. 3,902,064, 3,902,808, 3,904,907, 3,946,235 3,946,272, 3,984,727, 4,002,922 and 4,024,131 as well as other patents which all issued in the name of the present inventor. Reference is hereby made to these patents for background information relative to the basic operation of such lamps. In the present invention, the type of lamp generally shown in the above-identified patents is modified so that the central hollow dielectric electrode which has one end enclosed is modified to extend completely through the lamp bulb. Accordingly, the front window which exists in the referenced patents is not used in the present invention. It is effectively replaced by a cylindrical window which will be described below. In the present application, the use of the word "torus" will be basically understood from the dictionary definition which refers to the surface of a solid shape which is normally formed by a revolving plane closed curve about a line in its plane. The structure forming the torus may be shaped by continuous (but not uniform) deformation such that it can be transformed into a torus whose enclosed cross section can be outlined by any plain curve, with or without a tube connecting to the inner wall of the torus. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of one embodiment of the invention; FIG. 2 is a schematic diagram of the detecting circuit used relative to the output of FIG. 1; FIG. 3 is a schematic illustration of the interaction between the electrodes and the electric fields relating thereto; FIG. 4 is a schematic illustration of a modified electrode configuration; FIG. 5 is a partial cutaway schematic of a modification of the device of FIG. 1; FIG. 6 is an illustration of a further shape which may be assumed by the torus of the present invention; FIG. 7 is a schematic illustration of a modification of FIG. 1 showing means for separating surface currents from volume ion currents; FIGS. 8 and 9 are modified schematics of the embodiment of FIG. 1; FIGS. 10 and 11 are cross-section areas taken along the lines 10--10 and 11--11 of FIG. 8; and FIG. 12 is a simplified schematic of the embodiment of FIG. 8. BRIEF DESCRIPTION OF THE INVENTION The present invention provides a photoionizer which includes a light source comprising a hollow torus, an ultraviolet transmitting window substantially surrounding a passage through the torus, a gas filling within the torus, and means for creating an electrical discharge within said torus. It further includes an electrode means within said passage through said torus for collecting, or extracting, the ions produced by the said light source striking a gas within said passage, means for passing a preselected gas sample through said passage containing said electrode means, and means connected to said electrode means for measuring the interaction between said light source and said gas sample or extracting means able to project a beam of ions from the ionization region to an ion image outside the ionization region. Electrodes occur in pairs between which a potential difference is applied. In one case, an AC potential difference is applied to cause a discharge in the gas in the photoionization light source and in another case, a stable, or slowly varying, potential (relative to that causing a discharge) is applied to electrodes to collect or extract ions from a region near the light source window. These electrodes may be physically different, or one electrode of the AC potential pair may be composed of a physically distant pair between which a stable or slowly varying potential is applied while both are at nearly the same AC potential. In addition, the electrodes may perform other functions such as securing the light source or heating the light source. The photoionizer is operated in two modes; (1) when the gas sample being ionized is at high density so that the resulting ions have a mean free path smaller than a typical dimension of the ionization region, and (2) when the gas pressure is small such that the ion mean free path is large relative to a typical dimension of the dimension region. Ions are collected at high sample pressure and the device is used to measure the amount of parent gas in the sample from which ions are made by photoionization. At low pressure, the ions are extracted from the ionization region and projected or focused through an aperture for analysis and measurement as by a mass spectrometer or other means. In the use of this photoionizer, it is essential that ionizable species be introduced into the ionizing region. Some of these species, both in their natural and ionized form, become attached to the surface of the ionizer and its electrode structure. Often these react to form more complex species (such as crosslinked polymers), which are not subsequently released and flushed out of the ionizer. These residues form films which absorb the photoionization light and insulate the conducting surfaces of the electrodes. Both are undesirable, because they decrease the efficiency of the ionizer and increase its instabilities. These films are often insoluable in ordinary solvents and are difficult to remove. However, they do react with free radicals such as O, O 3 , H, OH, and others to form various gaseous products. In this way, complex hydrocarbons are removed as CO, CO 2 , OH, etc. when O is present and as CH, CH 2 , H 2 , etc. when H is present. The free radicals O, and H are easily produced by photolysis of oxygen and H 2 O by the photoionization radiation from the lamp, or by an electrical discharge produced in the gas which flows through the ionization region. Special provision can be made for this to occur by properly placing electrodes in or near the gas in the ionization region and by adding special cleaning gases containing O 2 and/or H 2 O or other simple compounds which will break down into free radicals. To insure that the free radicals react with the surface films, it may be required to reduce or increase the density of the gas in the ionization region or to dilute the species from which radicals are generated with a non-reactive gas, such as a rare gas. There are occasions when the ionizable constituents (or other species associated with these ionizable constituents) have a low, vapor pressure. To prevent them from condensing on the elements of the ionizer, the elements must be heated, perhaps to 300° C. This can be accomplished by utilizing some of the electrodes already present or by mounting the ionizer within a heated and thermally insulated region. Provision for this is also made without interfering with the normal operation of the ionizer. It is imperative that only photoionization occurs in the region from which ions are extracted or collected. To insure this, there must not be large fields in this region. The DC, or slowly varying ion collection potentials are, hence, small enough such that electrons or ions produced by photoionization are not accelerated to high enough energy to cause additional ionization by collision. When the ion collection electrodes are also used as the high voltage AC electrode for causing a discharge in the torus, it is essential that they be at the same high AC potential so as not to cause a large field inside the ion collection region. In addition, these electrodes must be so located near the dielectric envelope and far from other electrodes near the photoionization region, that the high AC fields are located inside the torus or in a region outside that from which ions are collected. All material is conductive, insulator or not and all surfaces conduct electric current. Such a basic physical fact is known and understood in all of the arts of electrical conductivity. For example, commercial electrometers, such as Keithley Instruments, Model 610C, incorporates special circuits to operate guard electrodes to intercept surface currents. This device is thoroughly discussed in its accompanying instruction manual. Texts on general experimental techniques such as "Procedures in Experimental Physics" by John Strong, Prentice Hall Inc., Inglewood Cliffs, N.J. 1938; Chapter 6: Electrometers and Electroscopes, pps. 217-259; and "The Physics of Experimental Methods", by H. J. J. Braddick, Reinhold Publishing Corporation, New York, N.Y. 1963, Chapter 6 which also discusses surface currents in guard electrodes. Experimentation has indicated that some materials become conductive when illuminated by UV or VUV radiation and in some instances this conductivity is a function of the concentration of ionizable species present in a fluid in contact with the material surface. This can produce a surface current to the electrodes (if they are in contact with such material) which are meant to collect ions produced in the gas by photoionization and so distort these measurements or contribute noise or offsets to them. It is clear that the surface conductivity and hence the surface current increases as the length between electrodes in contact with the surface decreases and as the length of the surface perpendicular to the applied field increase. However, the current derived from the ionization within the volume bounded by the surface photoconductor increases as this volume increases. The volume increase on the square of the length of the surface perpendicular to the applied electric field and so more rapidly than does the surface current while the volume ion current increases with an increase in surface length while the surface currents decrease. Hence, a large and long photoionization region favors volume currents relative to surface currents while short and small ionization volume favor surface currents relative to volume currents. However, surface currents can be eliminated by means which either intercept or interrupt the surface currents by guard rings or non-conductive segments of the surface such that the surface currents are not measured by the electrodes intended to measure the rate of ion production in the fluid itself. Part of the surface conduction path can be rendered non-conductive either by shielding it from UV or VUV radiation or by making a portion of this path of a material which does not show this photoconductivity effect. Alternatively, the ion collection electrodes may be mounted so as to make the surface conductive path very long and of small cross-section so as to decrease its conductivity to negligable importance. For alternative measurements, it may be desireable to favor the surface currents so that they may be used to measure the concentration of constituents in a fluid. In this method, the ionization volume is purposely made small in cross-section and short in length. Otherwise, this device can be identical to that discussed here except provisions to suppress or divert the surface currents are not employed. In fact when a guard electrode is employed in this configuration to divert surface currents from the volume ionization device, this same device can be used to measure the constituents in a fluid by surface current measurements and to divert volume ionization currents from the current measuring device by connecting the current measuring device to the guard electrode and using the volume current electrode to shunt the volume ion currents around this detector. When the electrodes used to collect ions produced from a weakly ionized gas are such that the electrodes do not "see" each other, because of an intervening dielectric "screen", it has been found that the measured current, I, is proportional to the applied voltage, V, between the electrodes. This behavior is characteristic of a resistor of resistance R, just as in ohms law, V=IR. In the geometry of this invention, it is observed that R -1 is approximately proportional to the rate of ionization occuring in the region between the electrodes. Since this rate is proportional to the density of ionizable species, along with other factors, a measure of I/V, or of I since V is fixed, constitutes a measure of the amount of ionizable species present in the ionizing region. This phenomenon has the characteristics of a surface conductivity effect, but is not. This mode of operation can be prevented by removing the dielectric screen. One physical device can be used to measure the concentration of an ionizable specie in a fluid either by surface conductivity while bypassing volume ionization currents or by measuring volume ionization currents while bypassing surface currents. It is also possible, by a choice of geometry, to measure the concentration of an ionizable specie in a fluid above some level (for example, 10 ppb) by volume photoionization current measurement and below this level by surface photoconductive current measurements. DETAILED DESCRIPTION OF THE INVENTION Turning now more specifically to the drawings, there is shown in FIG. 1 lamp 11 consisting of a torus 13 as defined and having a UV or VUV transmitting window 15 which is part of the central inner wall of the torus. The torus is hollow and includes a gas filling 17 and may have a gas source side arm 19 with an associated heating means 20 and a second side arm 22 containing a gettering material. There is also shown a pump stem 21 which is used to fill the torus with the particular design gas filling and which is subsequently sealed off after such filling process is complete. If required, heater 900 in conjunction with insulation 901 can be used to maintain the ionizer at an elevated temperature. In the embodiment shown in FIG. 1, a passage 23 is created by means of molding a wall 24 so as to conform to the inner passage of the torus. As shown, UV or VUV transparent material 15 is secured so as to form a section of the inner wall of the torus. Electrode structure 25, consisting of a cylindrical metal element, is secured adjacent said transparent material and is designed so as to have many openings. Element 25, as shown in the embodiment in FIG. 1, is a helical spring. However, it should be noted that a metal mesh could be used as well as a deposited electrode structure. Such structure will be referred to hereinafter as a semi-transparent electrode. A thin central electrode 27 passes centrally through the passage 23 and is substantially aligned in the axis of such passage. The two electrodes 27 and 25 are electrically insulated from one another. In the embodiment shown in FIG. 1, electrode 27 is maintained in the passage by means such as a glass ball 29 in which the electrode 27 is imbedded. Electrode 27 also passes through a spring compression unit 31 whereby the compression unit is adjusted within passage 23 so as to maintain the ball 29 nestled firmly against helical electrode 25 and also to maintain electrode 27 under tension. Spring compression unit 31 has passages 33 therethrough so that the gas may pass outwardly therefrom and, additionally, so that the outer electrode lead 35 may be passed outwardly from the detector. Electrode 100, in contact with the outer wall of the torus, holds the torus and is an electrical conductor at AC and DC ground. This electrode structure has two functions: First, it acts as a high AC voltage electrode to cause a discharge, preferably in the range of 50 KHz and 5000 MHz, between electrode 25 and electrode 100 in the torus which surrounds it and, secondly, it collects positive ions on the central electrode which are formed in the gas passing through the passage 23 by optical radiation from the discharge in the torus. FIG. 2 illustrates the circuitry used for accomplishing this purpose. Outer electrode 25 is connected to an AC resonance circuit 35 comprised of capacitor C5 and coil L1 as is the standard procedure in the above-identified patents. In the present useage, the circuit is modified whereby DC decoupling capacitor C1 is used so that the outer conductor 25 and the series resonant circuit composed of C5 and L1 can have an arbitrary DC voltage impressed upon it. This coil L2 and capacitor C4 which, together with the use of capacitor C1, isolates the RF and DC circuits. Central electrode 27 is connected to an electrometer circuit 37 which includes resistor R6. This connection is made through coil L4, and the RF voltage is filtered out by coil L5 and capacitor C3. Positive ions are collected on the central electrode where they are neutralized by electrons which pass from ground through resistance R6 of the electrometer, with the electrometer measuring the current which equals the rate of positive ion collection by the central electrode and, thus, relates to the amount of the particular ionizable gas which is passed through passage 23. An unwanted background is produced by electrons ejected from the conductive electrodes. Since the outer electrode is positive, any electrons ejected from it are collected by it and no current flows in the exterior circuit. However, electrons ejected from the negative central electrode move to the outer electrode and are therefore measured by the electrometer. This unwanted current may be minimized by making the central electrode wire as small as 0.001 inches in diameter so as to minimize the area from which electrons can be ejected compared to the volume of gas from which positive ions may be collected. The above configuration of the torus and the arrangement of the electrodes together with the circuitry has the following advantages. (1) The UV or VUV radiation from the bulb which surrounds the ionization region is efficiently coupled into that region. (2) The volume of this region is all effectively used and can be made small. (3) Photoelectron currents are made small due to the small area of the negative electrode. (4) Excitation of the dischare is effective, as is ion collection, while both use some of the same electrode structure. (5) Gas passage through the ionization region is direct and simple. In a slightly altered configuration the AC connections to electrode 25, via connector 35, is removed and connection 35 attached directly to DC generator 101 which is shunted by C4 so that electrode 25 is at AC ground, but at an arbitrary DC potential, and electrode 100 is connected to the juncture between C4 and L1 where connector 35 has been removed. Now C1 may be shorted and L2 removed. This configuration has the advantage that the electrodes used to collect ions do not have any AC voltages applied to them. This configuration can be further modified by physically replacing electrode 100 by a flat metal strip wound around envelope 13 so as to constitute coil L1. In this embodiment, electrode 100 becomes identical to coil L1. The gas filling the torus can be varied according to particular requirements, one of which is the desired wavelength distribution of the radiation. It may contain at least one rare gas or at least two rare gases. Further, it may contain at least one rare and one halogen containing compound. The material from which the torus is constructed is a dielectric such as glass, quartz, purified SiO 2 , Pyrex, Potash glass, or of an alkali metal resistant glass such as 1720 glass, 1723 glass and Gehlinite. The window itself may be sealed to the torus by a sealing compound which may be selected from the list consisting of epoxy resins, Silvac or AgCl/Ag pair, or a low melting sealing glass. Turning now to FIG. 3, there is shown a schematic illustration of the operation and the effects thereof within the passageway of the torus of a different electrode structure. The downward decending arrows indicate the discharge which occurs from the torus. A current generator G is connected to both the helical electrode 25 and, in this illustrative case, electrode 41. The resulting current in the helix establishes a uniform electric field along the axis of the electrode structure. This electric field causes the positive ions to pass in the direction as shown to the ground electrode 43 and the negative ions to pass in the reverse direction. The output from electrode 43 is connected to the electrometer. Accordingly, the resulting output to the electrometer will be indicative of the characteristics and the amount of the particular gas which is being examined. This usually is done at a high sample gas pressure. Electrodes 41 and 43 must permit gas to flow through them and, so, are of a mesh or grid structure. If electrode 43 is as described, or is a ring or short cylinder adjacent to the torus wall, and the sample gas pressure is low, ions will be extracted from the ionization region and projected along the electrical system axis. If the electrode 43 is complex so as to form an ion lens, the ions will be formed into an image at some distant point. FIG. 4 shows another and simpler electrode configuration. The discharge (vertical arrows) occurs between the outside ground electrode 201 and cylindrical electrode 204 when AC generator 202 is operating. When DC generator 203 applies a positive potential to electrode 204, positive ions are repelled to wire electrode 209 where they are collected and measured by an electrometer (not shown) after the AC signal is removed by coil L11 and capacitor C11. There are several variations in the size, shape, and positioning of the ion collection electrodes. These variations are meant to facilitate manufacture or assembly, to reduce photoelectron currents from the electrodes, to optimize the discharge in the light source, to minimize interference of the AC potential in the measuring of the ion currents, or to optimize the extraction and/or focusing of ions from the ionization region. FIG. 5 shows a configuration in which the electodes causing the discharge in the torus (47 and 110) are physically different from the electrodes (204, 209 or 41, 25 and 43) used for collection or extraction of ions from the region illuminated by the light source. In this case, there is less need for decoupling the ion collection potentials since they are coupled only indirectly by the capacitance between the separate electrode structures. Electrode 47, in conjunction with one of the other electrodes, if it is grounded, can be used to cause a discharge inside the sample gas so as to create free radicals for cleaning deposits from surfaces. Additionally, a discharge can be generated between electrodes 47 and 48. FIG. 6 illustrates one of the many configurations which the torus may assume. This can be formed easily in the process of making the device, and any particular configuration may be obtained from a practical standpoint. FIG. 7 shows an embodiment in which part of the surface conduction path is shielded from UV or VUV illumination by forming self-shielding corrugations in its shape. This same figure indicates how a conductive film (guard electrode) could be applied and connected so as to bypass the current paths from ion collection electrodes to its measuring device. Although, surface currents flow, they are not measured by the device which measure the currents which flow in the fluid within the ionization region. Not shown, but easily invisioned, are electrodes mounted on insulating mounts so as to increase the length of surface current path and so decrease its conductivity until it becomes unimportant. Referring specifically to FIG. 7, tungsten or platinum feed through 401 is a metal wire passing through the glass wall and making contact with platinum paint electrode 420 which would normally be the anode. Platinum paint 424 around this feed through provides an alternative means of contacting it. Corrugations 425 and 426 do not need to be of precise dimensions so long as a small region such as 427 is shadowed from UV or VUV radiation passing through the MgF 2 window 434. Platinum film electrodes 436 may completely surround the Kr gas filled space 438 and be connected to a AC high voltage source to cause a discharge in the Kr gas as it can be in the form of a coil, as shown, formed from flat strips and replace coil L1 in FIG. 2. Window 434 may be sealed to the glass with a AgCl seal. This may be accomplished by coating both sides of the proposed seal with platinum and melting (near 450° C.) the AgCl to flow over these surfaces to form a seal. Alternatively, a silver segment may be employed between the window and the glass tube forming part of the central gas passageway. Other sealing methods such as special glass slurries may be employed. Cathode 446 as shown in FIG. 7 may be a platinum film coating a portion of the entire central gas passageway 448 and in contact with feed through 449, (which is identical to feed through 401) by way of a platinum film strip so that electrode 451 is not contacted. A guard ring electrode 453 is shown on the window side of electrode 446 to intercept surface currents which are then conducted to feed through 451 by means of connection 455 which may be a wire or conducting film if it can bypass electrode 446 either by passing over it (after applying an insulating film on electrode 446 where it passes) or by configuring electrode 446 so as to leave a passageway for a platinum film strip to reach electrode 451. Also shown is a non-photoconducting material 461 which can also serve to prevent the surface currents from reaching the central electrode 446. All these devices are not used simultaneously and are shown together in FIG. 7 for economy of exposition. For example, no current would reach the guard electrode 453 if corrugations 425 and 426 are present or non conducting material 461 are present. FIG. 7 does not show the getter side arm or the source side arm which may be required and which would then be used. The corrugations 425 and 426 can also serve another important purpose by relieving the stress generated because of the mismatch of thermal expansion coefficients of the VUV window 434 and the material of the discharge bulb it is attached to. The flexure of the corrugations compensate for this mismatch. An alternative configuration would put the corrugations on the outer surface of the envelope. This configuration has the advantage that there are no "backwaters" in the sample flow path which would disturb the measurement of its content. Such exterior corrugations, although not shown in other figures, should be considered present if needed by the thermal characteristics of the material of the VUV window and the bulb envelope. FIGS. 8 through 11 show a preferred modification of the device of FIG. 1 which employs the method as described in FIG. 7 wherein the central gas passageway 500 and conduit 501 have been modified but all other components of the device remain substantially the same. In this embodiment, MgF 2 window 503 is shown as thicker and projecting into the central gas passageway. It is shown sealed to the material of the passageway by a AgCl seal 504, but any other method of fabrication could be used. Anode 505, is again a platinum film strip although many other means of forming it could be employed; for example, it could be a thin stamped metal insert. Anode 505 is connected to feed through 510 by a platinum film, but other means (such as a wire) are also possible. The feed through is a sealed wire passing through the material of the central gas passageway and can be identical to those shown in FIG. 7. The cathode in FIG. 8 is a press fit composite unit 550 (not shown) which buts against the projection of window 503 and guard electrode 508 and consists of 507 and 502 and shields cathode surface 507 from radiation passing through window 503 and insulates cathode surface 507 from surface guard ring 508 which is a platinum film strip on the inner edge of the window 503 projection into the central gas passageway. Cathode surface 507 contacts platinum film conductor strip 511 by a pressure contact between the conducting parts 507 and 511 which in turn contacts feed through 561. Guard electrode 508 contacts feed through 562. The orientation of cathode insert 550 prevents cathode surface 507 from being in contact with guard electrode 508 or its extension to feed through 562. Theportion of the conducting films, 511 and 508, used to reach feed throughs 561 and 562 which are somewhat removed from cathode insert 550 are coated with an insulating film 506 to prevent photoelectron emission. The extent of the window 503 projection into the central gas passageway 500 may be much less than shown or absent altogether. All components can be altered if they perform the functions alloted to them. FIGS. 9, 10 and 11 show these details more clearly. FIG. 12 is a diagrammatic illustration of a simpler version of the device of FIG. 8 which does not attempt to shield the cathode from UV and VUV radiation passing through MgF 2 window. The central gas passageway 600 contains, in order proceding from left to right, an electrical feed through 620 connected to anode 601 on the glass wall 603 of the passageway, MgF 2 window 602, guard electrode 606, connected to feed through 608, cathode 605 connected to feed through 607. A getter arm 601 is also illustrated. As to the getter, various materials may be used such as processed barium azide, barium metal or sintered metal. Further, if radiation characteristics of species other than the rare gas is required, this species can be generated by thermal decomposition of UrH 3 , UrD 3 , KMnO 4 , LiN 3 , ZnCO 3 , CuS0 4 .nH 2 O, AuCl 3 , AuI 3 , and AuBr 3 or as disclosed in the referenced patents. The heater can take many configurations and is schematically illustrated as a simple electric heater. However, it would preferably be a metal-film-on-plastic or ceramic resistor with a heat conducting material held in place by means such as a teflon shrink sleeve and/or an outer-inner insulating layer held in place by a second teflon shrink sleeve. Any means which accomplishes the thermal decomposition is satisfactory, but selection would be governed primarily by size and weight. It is obvious that any type of structural support may be used for retaining the device of the present invention in position, so long as it does not affect the electrical characteristics or block the gas or the discharge in the torus. The above description and drawings are illustrative only since equivalents may be substituted for various components described. Accordingly, the invention is to be limited only by the scope of the following claims.

There is provided a photoionizer which includes a light source comprising a hollow torus, an ultraviolet transmitting window substantially surrounding a passage through the torus, a gas filling within the torus, and means for creating an electrical discharge within said torus. The photoionizer further includes an electrode means within said passage through said torus for collecting, or extracting, the ions produced by the said light source striking a gas within said passage, means for passing a preselected gas sample through said passage containing said electrode means, and means connected to said electrode means for measuring the ions collected by said electrode means resulting from the interaction between said light source and said gas sample or extracting means able to project a beam of ions from the ionization region or from an ion image outside the ionization region. Means are also provided for either intercepting or measuring surface currents.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die including a slide cam. 2. Description of Related Art In the ordinary die, a lower die and an upper die are mounted respectively on a bed and a ram of a pressing machine so that piercing and forming processings can be accomplished by ascending and descending the upper die. Since the upper die is moved up and down, the transverse machining is effected by converting the vertical machining force to a horizontal machining force by using a cam member. This will be explained by the example of piercing the side wall of the work with the die including the cam member. As shown in FIG. 5 and FIG. 6, a positioning member 104 which positions the work 103 on a base plate 102 is scured to the lower die 101. At a position opposing a hole 105 to be pierced in the side wall of the work 103, a driven cam 107 including a punch 106 is slidably disposed. A heel 108 is secued to the rear side of the driven cam 107. A coil spring 109 is installed around the top side of the rod 110 which is threaded into the driven cam 107 inserted through the heel 108, and one end of the coil spring 109 is contacted with the heel 108, and a nut 112 is screwed onto the other end of the coil spring 109 via a washer 111 to urge such that the driven cam 107 is drawn back after piercing the work 103. A driving cam 118 is secured to a base plate 117 of the upper die 116 at a position opposing the driven cam 107. When the upper die 116 is descended, the driving cam 118 moves the driven cam 107 forward against the biasing force of the coil spring 109 to pierce the hole 105 in the work 103 by the punch 106 and a die 125, and when the upper die 116 is ascended, the driven cam 107 is moved rearward by the biasing force of the coil spring 109. For piercing the side wall of the work 105, as aforementioned, the driven cam 107 inculuding a punch 106 slides on the base plate 102 while approaching to and parting from the work 104. The driving cam 107 has to slide accurately to pierce by the punch 106 and die 125, therefore, flanges 121 are projected on lower opposite sides of the driven cam 107, and side guide plates 122 and upper guide plates 123 for guiding the flanges 121 are fixed to the base plate 102. In the aforementioned die, in order to allow the driving cam 107 to slide between predetermined positions, the side guide plates 122 for guiding the side faces of the flanges 121 projected on the sides of the driven cam body 107a, and the upper guide plates 123 for guiding the upper faces of the flanges 121 are disposed. Since these flanges 121, side guide plates 122 and upper guide plates on 123 are provided, a length l is projected respectively on opposite sides of the body portion 107a of the driven cam 107, the length l being usually about 100 to 150 mm at a minimum, whereby a large space is occupied on the base plate 102 of the lower die 101 of the press die. Accordingly, a large space is occupied when a cam mechanism is provided on the die. Since the large space is occupied by providing the cam mechanism, the die size is restricted by the bed area of the pressing machine and the necessary members may not be installed on the die, therefore, sometimes the machining processes must be increased and the die has to be added. A wear plate 124 provided on the tip of the flange 121 projected on the side of the body portion 107a of the driven cam 107 wears as the driven cam 107 repeats the sliding operations, producing a gap between the side guide plates 122, whereby the driven cam 107 cannot slide linearly and tends to meander by the existence of the gap. The punch 106 installed on the driven cam 107 also moves similarly in a serpentine fashion, thus the punch 106 is unable to punch in the state wherein a proper clearance is maintained circularly around the die 125, producing burrs around the punched hole, thus a high quality punching is impossible. Besides, due to the punching by the punch 106 and die 125 which produce the burrs, edges of the punch 106 and die 125 become damaged. SUMMARY OF THE INVENTION Therefore, in view of the aforementioned circumstances, the present invention is directed to a die including a cam member, which can be compactly designed in addition to the necessary function given as the cam member, and in order to accomplish high quality machining without moving the cam member in a serpentine fashion, the die includes a slide cam comprising: a slide cam base on the tip of which a polyhedral guide portion is formed, the slide cam which holds and supports the polyhedral guide portion of the slide cam base and slides along the polyhedral guide portion, and onto which machining tools such as a punch and a trimming edge are mounted; an elastic body interposed between the slide cam base and the slide cam for urging the slide cam, and a driving cam contacted to the slide cam for moving the same. The slide cam, when the upper die is descended, moves transversely between the driving cam and the slide cam base for pressing works such as piercing and trimming. When the works are completed and the upper die is ascended, the slide cam urged by the elastic body is returned. Furhter scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications with the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein; FIG. 1 is a longitudinal sectional view of a die including a slide cam of one specific embodiment of the present invention at a bottom dead point; FIG. 2 is a sectional view taken in the direction of the arrows substantially along the line II--II of FIG. 1; FIG. 3 is a sectional view taken in the direction of the arrows substantially along the line III--III of FIG. 1; FIG. 4 is a longitudinal sectional view of a cam mechanism of the present invention at a top dead point; FIG. 5 is a front view of a press die using a conventional cam mechanism; and FIG. 6 is a side view of FIG. 5. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The present invention will be particularly described as follows, referring to one specific embodiment shown in FIGS. 1 through 4 of the accompany drawings. FIG. 1 is a longitudinal sectional view of a die including a slide cam of one specific embodiment of the present invention at a bottom dead point, FIG. 2 is a sectional view taken in the direction of the arrows substantially along the line II--II of FIG. 1, FIG. 3 is a sectional view taken in the direction of the arrows substantially along the line III--III of FIG. 1, and FIG. 4 is a longitudinal sectional view of a top dead point. An example described in the embodiment involves a work pierced and trimmed at its lower end. On a base plate 2 of a lower die 1, a positioning member 4 which positions the work 3 is fixed by means of bolts 5. In the vicinity of the positioning member 4, a driving cam 8, onto which a guide member 6 whose upper surface is formed into an inclined plane which slants the positioning member 4 so as to contact with a V-shaped groove, is installed with bolts 7, and is fixed by bolts 9. On a base plate 12 of an upper die 11 opposing the driving cam 8, a slide cam base 13 is secured by bolts 14. The top of the slide cam base 13 is formed into a tetrahedral guide portion 16, which is generally quadrangular in cross section and provided with a crest line 15 at the lower end, and having an inclined plane which, symmetrically with the inclined plane of the driving cam 8, slants upward as approaching the positioning member 4. A slide cam 17 slidably holds and supports the tetrahedral guide portion 16 of the slide cam base 13, and slides on the guide member 6 of the driving cam 8. The slide cam 17 comprises a machining member 19 onto which a V-shaped groove member 18, punch and cutting edge are installed. The V-shaped groove member 18 is positioned by a key 20 driven into an opposing face of the machining member 19, and fixed by bolts 22 by raising a stopper 21. The upper end of the slide cam 17 is formed into a V-shaped groove which has the same inclined plane as that of the tetrahedral guide portion 16 of the slide cam base 13 for receiving the tetrahedral guide portion 16, and is provided with wear plates 23 fixed with bolts 24 to support lower planes 25 of the tetraheral guide portion 16, of the slide cam base 13. Upper planes 26 are urged by biasing plates 28 fixed by bolts 27 to the slide cam 17, which is disposed slidably on the tetrahedral guide portion 16 of the slide cam base 13. On the lower surface of the slide cam 17, a sliding member 29 which slides on the guide member 6 of the driving cam 8 and having its V-shaped groove in contact therewith is fixed by bolts 30. On the work machining side of the slide cam 17, a mounting plate 41 is installed by a bolt 42. A punch 43 is installed by fixing a punch plate 44 to the mounting plate 41 by means of a bolt 45. A trimming edge 51 is fixed to the mounting plate 41 by means of a bolt 46. A stripper plate 47 is provided against which a rubber cushion 48 is urged by the work 3 before the work 3 is pierced and trimmed. The numeral 49 generally indicates a die which is engaged with the punch 43 for piercing, and the numeral 50 denotes a cutting edge which trims the edges of the work 3 in cooperation with the trimming edge 51. A retaining hole 61 is formed at the rear end portion of the tetrahedral guide portion 16 of the slide cam base 13 for retracting the slide cam 17 after machining, and a support plate 62 is disposed at a position opposing the retaining hole 61 and secured to the slide cam 17 by means of a bolt 63. An elastic body 64 such as a coil spring is provided between the retaining hole 61 and the support plate 62. When the upper die 11 is ascended, the slide cam 17 is retracted by biasing force of the elastic body 64. For the purpose of stopping the retraction of the slide cam 17, the stopper 21 raised on the slide cam 17 is engaged with an end portion 65a of a stopping groove 65 formed in the crest line at the lower portion of the tetrahedral guide portion 16 of the slide cam base 13. And, for safety purposes, a safety stopper 66 is screwed into the retaining hole 61 to fix the position of the coil spring, and at the same time, the safety stopper 66 is extended through the support plate 62 and provided with a head portion 66a at its end, so as to stop the stopper 21 by the support plate 62 which collides aganist the head portion 66a, in case the stopper 21 does not stop at the end portion 65a of the stopping groove 65. Also, for retracting the slide cam 17 forcibly when the upper die 11 is ascended, a return plate 71 is secured to the slide cam 17 with bolts 72, and engaged with the driving cam 8 at the lower end thereof. Next, the operation of the die will be described. As shown in FIG. 4, the work 3 is placed on the positioning member 4 and the upper die 11 is descended. FIG. 4 shows a top dead point, where the slide cam 17 disposed slidably on the tetrahedral guide portion 16 of the slide cam base 13 installed on the base plate 12 of the upper die 11, is in contact with the stopper 21. When the upper die 11 is descended from this state, the sliding member 29 of the slide cam 17 contacts the guide member 6 of the driving cam 8, and the slide cam 17 proceeds toward the work 3 between the driving cam 8 and the slide cam base 13 as the upper die 11 is descended, to pierce the work 3 by the punch 43 and to trim the lower portion of the work 3 with the trimming edge 51. The state wherein piercing and trimming are effected by the punch 43 and trimming edge 51, and the upper die 11 is at the bottom dead point is shown in FIG. 1. Thereafter, when the upper die 11 is ascended, the urging force of the elastic body 64 is transmitted to the slide cam 17 from the support plate 62 to retract the slide cam 17, which is prevented by its stopper 21 from contacting the end portion 65a of the stopping groove 65. Since the return plate 71 is provided on the slide cam 17, when the slide cam 17 fails to retract, the return plate 71 is engaged with the driving cam 8 to forcibly retract the slide cam 17. In the aforementioned embodiment, though the example in which the slide cam base 13, slide cam 17 and driving cam 8 are arranged in order from top to bottom is described, they may be arranged in order of the driving cam 8, slide cam 17 and slide cam base 13 from top to bottom. That is, a unit comprising the slide cam base 13, slide cam 17 and the driving cam 8 may be used reversely. Furthermore, though the example of piercing and trimming was described in the embodiment, it is to be understood that the present invention may by applied to other forming and bending processings. Besides, when size of the slide cam base 13, slide cam 17 and driving cam 8 are standardized, machining of works having various sizes can be performed immediately. As described heretofore, since the present invention is directed to a die including a slide cam compressing: a slide cam base on the top of which a polyhedral guide portion is formed; the slide cam which holds and supports the polyhedral guide portion of the slide cam base and slides along the polyhedral guide portion, and onto which machining tools such as a punch and a trimming edge are mounted; an elastic body interposed between the slide cam base and the slide cam for urging the slide cam; and a driving cam contacted to the slide cam for driving the same, a cam mechanism can be constituted without disposing cam guiding flanges, side guide plates and upper guide plates, and the cam mechanism can be provided on the die in a minimum amount of space. Since a large space is occupied by the conventional cam mechanism, the size of die is restricted by the bed area of the pressing machine, so that the necessary members cannot be provided on the die, thus the machining processes must be increased and the die has to be added, but in the present invention, for reasons aforementioned, it is not necessary to add the die. In the cam mechanism of the present invention, since little space is occupied, for the work having a curved surface, machining can be effected from the direction suitable to the curved surface or from the normal direction to the curved surface, so that in case of piercing or forming a circular hole, it can be finished in a true circle and not in an ellipse, improving machining quality. Also, in the present invention, a die can be made smaller and lighter at low cost in a short period of time. Since the die is small, it is can be machined with small-sized machine tools and cranes in die machining facilities. Moreover, in the die of the present invention, since the slide cam is slidably held and supported by the slide cam base, even when the sliding portion is worn by extended use of the die, the cam does not meander as the conventional die, but moves linearly, thus a high quality pressing work can be accomplished. Besides, since the slide cam base moves precisely in the linear direction, edges of the punch, die and cutting edge do not break. In the embodiment of the present invention, since the sliding faces of the slide cam and the driving cam are formed into the V-shaped groove, there is no possibility that the cam meanders. Also, in the present invention, as a sliding mechanism is provided in the center portion of the cam, it can be divided into small sections, and as compared with the conventional cam in which the flanges are protected on opposite sides, the cam divided into the small sections can be held and supported at many locations, so that when compared with the conventional large member which can be held only on both sides, the cam can be held securely. Meanwhile, when cam parts are standardized, the present invention can be applied immediately to the machining of the works having various sizes. Though abrasion tests were run by the inventor for 300,000 times, using the die including the slide cam having the construction of the embodiment shown; the wear rate was aout (1.5 to 2.5)×1/100 mm and the wear rate of the ordinary slide cam was about 5/100 mm×1/3, showing good results.

In a die including a cam member, which can be compactly designed in addition to the necessary function given to a cam member, in order to accomplish high quality machining without moving the cam member in a serpentine fashion, the die includes a slide cam having a slide cam base on the top of which a polyhedral guide portion is formed, the slide cam which holds and supports the polyhedral guide portion of the slide cam base being slidable along the polyhedral guide portion, and onto which machining tools such as a punch and a trimming edge are mounted, an elastic body interposed between the slide cam base and the slide cam for urging the slide cam, and a driving cam contacting the slide cam for driving the same.

TECHNICAL FIELD This invention relates to voice messaging systems, and more specifically, to a system and method for selecting particular announcements provided by voice messaging systems. BACKGROUND OF THE INVENTION Because of the wealth of features offered by voice messaging systems, the last few years have witnessed an explosive growth in the use of such systems to meet communication needs that do not require direct person-to-person interactions. In such systems, the caller is ordinarily invited by a personalized or system announcement to leave a message because the called party is busy or unavailable. Alternatively, an announcement can provide a caller with various types of information, such as an initial prompting command or an alternate telephone number at which the called party may be reached. Typically, these announcements are pre-recorded in a particular language by the voice messaging system administrator or the called party. Unfortunately, the inflexibility of this approach prevents voice messaging systems users who do not share a common language to take full advantage of the communications benefits of such systems. The effects of this deficiency are manifested when an international caller is greeted by an incomprehensible foreign language announcement from a voice message system. As a result of the somewhat obscure nature of the greeting or announcement, the international caller and the called party are deprived of the full benefit of the voice messaging system. For example, callers are unable to verify that they have reached the right called party and consequently, may forego the opportunity to leave messages of a personal or confidential nature, notwithstanding the expense of the call. Similarly, any information provided by the announcement falls on "deaf ears". This one-language limitation of the prior art takes on particular significance when one considers a) the increasing use of voice messaging systems in international communications (especially between countries with significant time zone differences) and b) the wide variety of languages spoken by users of voice messaging systems. SUMMARY OF THE INVENTION This invention is directed to the selection by a voice messaging system of a pre-recorded announcement to be played to a caller in a language determined, based on source information that is associated with the call and that is indicative of where the call originated. In an illustrative embodiment of the invention, a voice messaging system receives the caller's Calling Line Identity (CLI) or equivalent information, such as the originating country code, and/or the area code. The voice messaging system a) compares the originating country code of the caller to a stored language code selection list that associates particular call origination locations with predominant language(s) spoken at those locations, and b) based on the results of the comparison, delivers the system's messages to the caller in the language that is most likely understood by the caller. In accordance with a feature of the invention, the voice messaging system may invite a caller from a multilingual country to select a preferred language for an announcement from a list of languages derived from matching the caller's country code and/or area code to corresponding fields in a stored selection table. Language selection is offered to the caller, via short prompting announcements delivered by the voice messaging system, in descending order of language dominance. When the caller selects a particular language, the voice messaging system thereafter delivers all further system messages in that language. BRIEF DESCRIPTION OF THE DRAWING In the drawing: FIG. 1 illustrates the connectivity between a) a telecommunications network which routes a call from a caller to a called party, and b) a voice messaging system arranged in accordance with our invention to receive source information associated with a call and to deliver announcement(s) in the language of the caller, FIG. 2 shows the different fields that may be represented in the source information; FIG. 3 illustrates an exemplary arrangement for the voice messaging system of FIG. 1 comprised of hardware components and software programs needed to implement our invention; FIG. 4 is a table illustrating a list of countries with corresponding country codes and dominant languages that may be stored in a database of the voice messaging system; FIG. 5 illustrates an exemplary language priority table that may be stored in the database, and that indicates the order of language dominance for different regions of a particular country; and FIG. 6 is a table illustrating a list of some countries in the North American Dialing Plan with corresponding country codes and dominant languages that may be stored in a database of the voice messaging system; FIGS. 7 and 8, and 9 represent flow charts illustrating the process followed in voice messaging system 113 to implement the language selection features afforded by this invention. DETAILED DESCRIPTION FIG. 1 shows the connectivity between a) a telecommunications network which routes a call from a caller at station set 101 to a called party at station set 110 or 111, and b) voice messaging system 113 arranged in accordance with our invention to receive source information associated with a call and to deliver announcement(s) in the language of the caller. As shown in FIG. 1, a call placed by a caller at station set 101 is routed along with the dialed digits to originating communications network 103 via local loop transmission facility 102. Communications network 103 includes means, such as local, toll and international gateway switches, and a signaling network, to process and route local, long distance and international telephone calls. In this example, the dialed digits indicate to originating communications network 103 that the call is destined for a different communications network at a distant location, such as a foreign country. Accordingly, communications network 103 generates control signals, including a) connection request signals, and b) destination and source information associated with the call, to establish a connection to a destination communications network 107 which includes similar means to those found in communications network 103. Communications network 107 uses the destination information received from originating communications network 103 via, for example, an out-of-band signaling channel of trunk 105, to route the call to voice switching system 109, which may be a PBX or a central office switch. In addition, destination communications network 107 uses its signaling network to forward source information associated with the call to voice switching system 109 via, for example, an out-of-band signaling channel of trunk 108. Voice switching system 109 then applies a ringing tone to the called party's station set, say station 111. The logic in voice switching system 109 is arranged so that a busy tone or ring-no-answer condition at station set 111, for example, triggers voice switching system 109 to forward not only the call but also source information associated with the call to voice messaging system 113. Typically, voice messaging system 113, upon receiving a call, greets the caller with either an announcement inviting him or her to leave a message, or a prompting announcement soliciting information from the caller in order to select further announcements. In accordance with our invention, the languages in which announcements or messages are transmitted to a caller are selected based on the source information received by voice messaging system 113, as fully described below. The aforementioned source information associated with a call is generated in communications networks 103 and/or 107, and passed along with the call to voice messaging system 113 of FIG. 1. FIG. 2 illustrates different fields that may typically be included in the source information. Originating country code 21 is a numeric field (typically one to three digits) indicating the region or country from which the call originated. Area or trunk code 22 is also a numeric field (typically one to three digits) designating a regional area served by a particular switching center or a trunk group. Local loop subscriber number 23 represents a numeric field (typically four to seven digits) representing the local telephone number of the caller. Source information comprising all three fields described above is commonly called "Calling Line Identity" (CLI) by persons skilled in the art. By contrast, when only area/trunk code field 22 and local loop subscriber number field 23 are included in the source information, the latter is referred to as "Automatic Number Identification" (ANI). The type of source information received by voice messaging system 113 depends upon a) the specific capabilities of the switches and signaling networks within communications networks 103 and 107, gateway switches 104 and 106, and b) the "relationship" of the locations of communications networks 103 and 107. For example, when two countries (such as the United States and Canada) have a common originating country code (001) because they participate in a common numbering plan (North American Dialing Plan), originating communications network 103 forwards the ANI as opposed to the CLI to destination communications network 107. On the other hand, the source information may contain only the originating country code in other situations. For example, when a caller dials an international toll-free number that is forwarded by originating communications network 103 to destination communications network 107, the latter can extract the country code from the received dialed digits prior to translating them into a network routing number. Alternatively, when a call is received through the facilities of a dedicated trunk linking two countries exclusively, destination communications network 107 can identify the originating country code from a particular trunk subgroup number of that dedicated trunk. FIG. 3 illustrates an arrangement of voice messaging system 113 designed in accordance with our invention for announcement language selection, based on source information associated with a call. Voice messaging system 113 may be implemented using as a hardware platform, a personal computer or a minicomputer running software programs designed to perform specialized functions, such as delivering, recording, retrieving and storing voice messages. One well-known voice messaging system, which may be used with appropriate modifications to implement our invention, is the AT&T audio exchange (AUDIX) system. A voice messaging system arrangement similar to the architecture of the AUDIX system is disclosed in U.S. Pat. No. 4,790,003 issued to G. D. Kepley, et al. on Dec. 6, 1988 which is incorporated herein by reference. As shown in FIG. 3, voice messaging system 113 includes controller 301, random access memory 302, database 303, signal processing unit 304, and digital interface unit 305, all interconnected by a bus 300. Database 303 includes, inter alia, program instructions which, when loaded into random access memory 302, are accessed and executed by controller 301, which is a central processing unit. Controller 301 supervises the operations of, and directs data traffic to and from, all the other components of the system via bus 300. In particular, controller 301, under the control of programs stored in database 303 manages the establishment and tearing down of connections between voice messaging system 113 and voice switching system 109 through the hardware and software facilities of digital interface unit 305. Additionally, controller 301 can issue instructions to query database 303 to retrieve a) records from the tables shown in FIGS. 4 and 5 (about to be described) and b) voice files representing system announcements or messages recorded in a plurality of languages, in accordance with the invention, and stored therein, advantageously in compressed format. Signal processing unit 304 is provided to decode and expand stored voice files into 64 kbps speech which is output to callers via digital interface unit 305. Illustrated in FIG. 4 is a table stored in database 303 containing a list of different countries or geographic areas identified by name (country name) and country code (meaning originating country code described above). In FIG. 4, each row represents a record called a "national announcement selection record". This type of record is retrieved, for example, when the source information contains only the originating country code. The national announcement selection record is comprised of the country name, the country code, the number of dominant languages and the dominant language fields. The last two fields represent national linguistic information. More specifically, a significant number of countries have one dominant language which is indicated by a value of "1" in the number of dominant languages field. Some countries like Belgium, for example, have two dominant languages, namely French and Flemish listed in the dominant language(s) column in descending order of dominance. FIG. 5 illustrates an exemplary language priority table stored in database 303 indicating the order of language dominance for different regions of a particular country. In FIG. 5, each row represents a record called a "regional announcement selection record" comprising the country name, the number of dominant languages spoken in that country, the area/trunk code, and the language priority array. This type of record is used for example when the source information contains only the ANI or when detailed regional linguistic information is needed for a multilingual country. The language priority array column lists, in descending order of dominance, languages spoken in areas of a country identified by the area/trunk codes. FIG. 6 is a table illustrating a list of some countries in the North American Dialing Plan with corresponding country codes and dominant languages that may be stored in a database of the voice messaging system. In FIG. 6, the list of area codes for Canada is divided into two groups reflecting the order of language dominance for regions of Canada served by those area codes. For example, Quebec, a Canadian province in which French is the most dominant language, is served by area codes 514, 418 and 819. In all the other provinces of Canada, English is the most dominant language. Referring to FIG. 7, the process contemplated by our invention, which is carried out under the control of controller 301, is initiated in step 701 when voice messaging system 113 receives the caller's source information (ANI, CLI or originating country code) in response, for example, to a busy or ring-no-answer condition at the called party's station set. In step 702, the received source information is analyzed to determine whether it contains an originating country code. Upon an affirmative answer to that inquiry, originating country code 21 is analyzed in step 703, to determine whether the call originated from a country or region participating in the North American Dialing Plan. As mentioned earlier, a value of "001" for originating country code 21 is indicative of a country's or region's participation in the North American Dialing Plan. If originating country code 21 has a value of "001", the steps described in FIG. 9 (discussed below) are executed by voice messaging system 113. Otherwise, database 303 is queried, in step 704, to retrieve the particular one of the national announcement selection records of FIG. 4 that is associated with the received country code. If originating country code 21 is not present in the source information, the latter is analyzed, in step 709, to determine whether area/trunk code 22 is included therein. If area/trunk code 22 is present in the source information, database 303 is queried in step 711, using the area/trunk code as a search key to retrieve the particular one of the regional announcement selection records (illustrated in FIG. 5) and that is associated with the received area/trunk code. In steps 705 and 706, voice messaging system 113 examines the number of dominant languages field to determine whether the country/geographical area is multilingual. The multilingual test is passed when the number of dominant languages field has any value greater than one. For a value of "1" in the number of dominant languages field, database 303 is queried to retrieve a stored message in the dominant language code indicated in the announcement selection record. The message may be a compressed binary file which is a digital representation of a pre-recorded announcement. In step 707, database 303 forwards the retrieved binary voice file via bus 300 to signal processing unit 304, which decodes and expands the file into a 64 kbps speech output signal played to the caller. Note that other types of voice storage can also be used. If the number of dominant languages field has a value greater than "1", the instructions illustrated in FIG. 8 are executed. However, the regional announcement record is first retrieved in step 708 if it was previously determined in step 702, that the originating country code is available. It is worth noting that a regional announcement selection record is retrieved even in the case where no area code is available since there is an entry in the regional announcement selection record for that eventuality. If neither the originating country nor the area code is included in the source information, voice messaging system 113, in step 710, plays a standard system message to the caller. Referring to FIG. 8, voice messaging system 113, in step 801, retrieves the first language in the language priority array from the record of FIG. 5. Using the techniques described above, voice messaging system 113, in step 802, plays a "prompting announcement" in the designated language. By prompting announcement, we mean a message inviting the caller to select a preferred language. In step 803, voice messaging system 113 determines within a predetermined time period whether the caller responds to the prompting announcement or ignores it. The latter alternative is indicative of the likely inability of the caller to understand the language in which the announcement was delivered. Thus, if silence of a predetermined duration, as opposed to a response to the prompting announcement, is detected, the logic in voice messaging system 113 is arranged to conclude that the caller cannot understand the prompting announcement in that language. As a result, in step 804, voice messaging system 113 determines whether there is another language entry left in the array. Upon an affirmative answer to that inquiry, steps 801 to 803 are repeated, playing prompting announcement(s) in another (other) language(s). If the caller, however, responds to the prompting announcement by entering, for example, dual tone multiple frequency (DTMF) signals (commonly known as touch tones), voice messaging system 113, in step 805 delivers a prerecorded system message using the same language in which the prompting announcement was played and to which the caller responded. The prerecorded system message may provide, for example, general information to the caller, such as an alternate telephone number for the called party to be reached. If the caller does not respond to any prompting announcement and there is no entry left in the array, voice messaging system 113, in step 806 delivers the system message several times in different languages, in descending order of language dominance prevalent for the entire population of the country/geographical area. As mentioned earlier, if originating country code 21 has a value of "001", the instructions described in FIG. 9 are executed by voice messaging system 113. Referring to FIG. 9, voice messaging system 113 in step 901 determines whether area/trunk code 22 is included in the source information. Upon an affirmative answer to that inquiry, database 303 is queried, in step 902, to retrieve the North American announcement selection record of FIG. 6 associated with the received area/trunk code. In step 903, voice messaging system 113 examines the number of dominant languages field to determine whether the country/geographical area is multilingual. For a value of "1" in the number of dominant languages field, database 303 is queried, in step 904 to retrieve a stored message in the dominant language indicated by the dominant language field. For a value greater than "1" in the number of dominant languages field, the instructions illustrated in FIG. 8 and described above are executed by voice messaging system 113. If the source information does not include the area code, voice messaging system 113, in step 905, plays the system announcement in English. To illustrate the operations of the multilingual aspect of our invention, let us take the example of a Canadian wholesaler placing a call to an exporter in Germany. Voice messaging system 113, upon receiving the caller's CLI, determines from country code 21 and area code 22 that the caller is located in Quebec, where the dominant language is French. An exemplary prompting announcement may convey the following message to the caller "Si vous parlez francais, pressez la touche 1", followed by a short pause, and the additional message "If you speak English, press 2". The first part of the announcement can be translated into English as follows: "If you speak French, press 1". If the caller presses 1, the system message is then played in French. Similarly, if the caller enters 2, the system message announcement is played in English. By contrast, if voice messaging system 113 determines, based on the area code, that the caller is from an English-speaking province of Canada, the prompting announcement is first played in English followed by a short pause and the French prompting announcement. The above description is to be construed as only an illustrative embodiment of this invention. Persons skilled in the art can easily conceive of alternative arrangements providing functionality similar to our invention without any deviation from the fundamental principles or the scope of this invention.

A voice messaging system is designed to select an announcement for a caller based on source information associated with a call initiated by that caller. The voice messaging system a) compares at least a portion of the source information to a stored language code selection list that associates particular call origination locations with predominant language(s) spoken at those locations, and b) based on the results of the comparison, delivers the system's message to the caller in the language that is most likely understood by the caller.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 12/327,941, entitled Cascading Definition and Support of EDI Rules, filed Dec. 4, 2008, now allowed, which is a continuation of U.S. Ser. No. 11/232,839, entitled System and Method for the Cascading Definition And Support Of EDI Rules, filed Sep. 22, 2005, now U.S. Pat. No. 7,475,051, which claims the benefit of U.S. Provisional Application Ser. No. 60/612,140, filed Sep. 22, 2004, the entire disclosures of which are incorporated by reference herein. BACKGROUND [0002] For speed of communications and cost effectiveness, individuals, businesses, and other organizations frequently exchange electronic data through e-mail, the Internet, and other networks and systems. Companies increasingly rely on third-party applications on the Internet to accomplish a wide range of intended purposes, often involving the exchange of electronic documents. [0003] Electronic Data Interchange (EDI) [0004] To help establish compatibility for electronic data exchanges, the American National Standards Institute (ANSI) Accredited Standards Committee (ASC) has developed a set of standards for electronic data interchange (EDI) called the X12 standards, which defines the content and structure for data contained in electronic data files. For example, in EDI X12, a standard HIPAA (Health Insurance Portability and Accountability Act) “837P” interchange document represents an electronic data file used for filing patient claims to a health insurer. [0005] Example of an EDI Document [0006] An EDI document is a flat list of text, the divisions of which are not easy to determine. The following, abbreviated code shows a typical EDI interchange document: [0000] ISA*00* *00*   *ZZ*WEBIFYSE  *ZZ*00AAA *020220*1243*U*00401*100000034*0*T*:~GS*HS*WEBIFYSE*00AAA*20020220*2314 *123456789*X*004010X092Al~ST*270*3120~BHT*0022*13*10001234*19990501*103045 *RT~HL*1**20*1~NM1*PR*2*Sample BCBS*****FI*999999999~HL*2*1*21*1~NMI*1P*2*Sample Clinic*****FI*888888888~REF*1J*0035~HL*3*2*22*0~TRN*1*93175- 012547*9323233345~NMl*IL*1*SMITH*JOHN*M***MI*333440623~DMG*D8*19510918 ~DTP*472*RD8*20031201- 20031201~EQ*30**FAM*GP~SE*14*3120~GE*1*123456789~IEA*1*100000034~ [0007] In this interchange document, the elements ST and SE represent the start and end of a business transaction that may contain many additional elements. [0008] An EDI document may be associated with more than one entities. [0009] Example of EDI Transaction Segment [0010] The following line shows a typical segment of an EDI business transaction in an 837P interchange document: [0011] NM1*H*DOE*JOHN*78747 [0012] In this example, the letters “DOE” might represent the last name of a specific individual. The field where “DOE” appears might indicate the last name of a patient submitting a claim. Similarly, the numbers “78747” might represent a specific individual's zip code and the field where “78747” appears might indicate the zip code of a patient filing a claim. [0013] Implementation Guides [0014] To promote standardization in the formats used in EDI documents, the Workgroup for Electronic Data Interchange (WEDI) organization has created implementation guides of standard rules. For example, the implementation guide for an EDI document might stipulate that for NM 1, a valid zip code of five characters needs to exist. An implementation guide requirement for a different part of the same EDI document might be that a payer identification number needs to be 45 characters long. [0015] Companion Guides [0016] Implementation guides, however, do not cover the different, often changing requirements of regulatory bodies and individual companies. For example, the states of Florida and Texas would require different ranges of zip code numbers in patient claims. The American Medical Association may have guidelines for patient claims that change over time. And requests to different companies would, of course, require different company names or payer identification numbers. If a company changes its name, a different name or identification number might have to be supplied in patient claims. [0017] To be able to use the EDI documents they receive, companies therefore typically create rulebooks, for example companion guides, to be used on top of implementation guides, to stipulate their particular requirements and the requirements of the bodies that govern them. In FIG. 1 , for example, the company at payer server 1 170 may have companion guide 1 410 . The company at payer server 2180 may have a different companion guide 420 . [0018] Companion guides, which are usually PDF files, are not machine readable, and each, may contain thousands of rules, making them difficult to read and comply with. For example, with over 600 insurance companies in the United States alone, companies that have to send EDI documents to numerous insurance companies have great difficulty identifying and meeting all the requirements in different companion guides. Moreover, other types of EDI documents in other areas of business have similar implementation guides and companion guides for different companies services, so that that challenge of interoperability through different industries is quite large. [0019] Clearing Houses [0020] Business entities, such as health insurance payers, often use third party clearing houses to validate that the EDI documents being sent to the entities from companies such as health care providers comply with the entities' rulebooks or companion guides. [0021] Typically these clearing houses manually write programs or use manually programmed third party engines to identify the requirements in each companion guide and then to automatically analyze each EDI document to discover whether the EDI document meets the requirements of the appropriate companion guide. Such a process is unnecessarily laborious, expensive, and time consuming, because the rules shared among many companion guides have to be written many times. [0022] Therefore there is a need for a method and system that provides a more automatic method to validate the compliance of EDI documents with companion guides. BRIEF SUMMARY [0023] According to various aspects of the present invention, computer program products and systems are provided to validate a plurality of electronic data interchange (EDI) documents, where each EDI document is associated with at least one of a plurality of entities. [0024] Aspects of the present invention relate to a system for validating EDI documents that includes computer system having a processor, a memory, a storage device, a network interface, and a bus for exchanging information therebetween In particular, the memory stores computer usable program code executed by the processor to a) provide an inventory of all rules, the inventory including a common set of rules for a plurality of entities; b) dynamically adjust the inventory of all rules based upon entity specific rules where the entity specific rules are derived from a plurality of companion guides, each companion guide associated with one of the plurality of entities; and c) create a rules analyzer to analyze content of the plurality of companion guides and to build an organizer of companion guide rules. The memory further stores additional computer usable program code that is executed by the processor to employ the organizer of companion guide rules to add companion guide rules to the inventory of all rules; create a profiles engine to create a respective, current rule set for each of said plurality of entities; and to create a companion guide profile for each of the plurality of entities where each companion guide profile indicates that entity's companion guide rules and provides pointers to the rules in the inventory of all rules that are associated with the respective, current rule set of that entity. Ultimately the system creates a runtime checker engine to validate an EDI document by comparing the EDI document to the respective, current rule set associated with a corresponding one of the plurality of entities, by forwarding the EDI document to the corresponding one of the plurality of entities if the EDI document matches its current rule set, wherein the EDI document is validated and by returning the EDI document to a sender if the EDI document does not match the respective, current rule set, wherein the EDI document is invalidated. The computer usable program code of this system can be embodied on a computer readable storage medium as well in order to provide a corresponding computer program product. [0025] Additional aspects of the present invention relates to a system for determining EDI rules to enforce. In particular, the system includes a computer system having a processor, a memory, a storage device, a network interface, and a bus for exchanging information therebetween. More particularly, the memory stores computer usable program code that is executed by the processor to a) determine entity-specific rules from corresponding companion guides for each of a plurality of entities; b) express each entity-specific rule in a neutral and machine readable format; c) classify each of the entity-specific rules; and d) convey results of classifying the entity-specific rules. In particular, classifying each of the entity-specific rules, includes determining for each entity-specific rule whether the entity-specific rule is common with at least one other entity-specific rule, or whether the entity-specific rule is similar to at least one other entity-specific rule, or whether the entity-specific rule is unique. Also, conveying the results of classifying the entity-specific rules includes creating an inventory of rules, the inventory including a common set of rules for the plurality of entities; dynamically adjusting said inventory of the rules based upon the entity-specific rules where the entity specific rules are derived from a plurality of companion guides, each companion guide associated with one of the plurality of entities; storing the inventory of rules in a storage according to the classification of each rule as common, similar, or unique; creating a respective, corresponding pointer to the entity-specific rules in the inventory of rules associated with at least one of the plurality of entities; and storing the corresponding pointer in a storage for use in retrieving an appropriate current rule set when validating an EDI document for the at least one of the plurality of entities. The computer usable program code of this system can be embodied on a computer readable storage medium as well in order to provide a corresponding computer program product. BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS [0026] The following embodiment of the present invention is described by way of example only, with reference to the accompanying drawings, in which: [0027] FIG. 1 is a block diagram showing an operating environment in which embodiments of the present invention may be employed; [0028] FIG. 2 is a flow chart showing a process for validating the compliance of EDI documents with companion guides; [0029] FIGS. 3A and 3B are flow charts showing a process for setting up a system to validate the compliance of EDI Documents with companion guides; [0030] FIG. 4 is a flow chart showing a process for employing an organizer of CG rules; [0031] FIG. 5 is a flow chart showing a process for using a rule set to validate an EDI document; and [0032] FIG. 6 is a block diagram that illustrates a typical computer system, representing a server on which embodiments of the present invention can be implemented. DETAILED DESCRIPTION [0033] The following description explains a system to provide an automatic method to validate the compliance of EDI documents with rulebooks such as companion guides. The details of this explanation are offered to illustrate the present invention clearly. However, it will be apparent to those skilled in the art that the concepts of present invention are not limited to these specific details. Commonly known elements are also shown in block diagrams for clarity, as examples and not as limitations of the present invention. [0034] Operating Environment [0035] An embodiment of the operating environment of the present invention is shown in FIG. 1 . A party uses server 1 100 to operate a clearing house service for providers such as provider server 1 150 and provider server 2 160 and entities such as payer server 1 170 and payer server 2 180 . [0036] Payer 1 170 has companion guide 1 410 that stipulates its particular requirements for EDI documents and the requirements of the bodies that govern it. In the same way, payer server 2 180 has companion guide 2 420 . [0037] Provider server 1150 has EDI document 1 310 and provider server 2 160 has EDI document 2 320 . [0038] Server 100 can communicate with servers 150 , 160 , 170 , and 180 via a wired or wireless link 142 , a wired or wireless network 130 , and wired or wireless links 144 , 145 , 146 , and 148 . The servers 100 , 150 , 160 , 170 , and 180 may be personal computers or larger computerized systems or combinations of systems. [0039] The network 130 may be the Internet, a private LAN (Local Area Network), a wireless network, a TCP/IP (Transmission Control Protocol/Internet Protocol) network, or other communications system, and can comprise multiple elements such as gateways, routers, and switches. Links 142 , 144 , 145 , 146 , and 148 use technology appropriate for communications with network 130 . [0040] Through the operating environment shown in FIG. 1 , a clearing house service at server 1 100 can be used to validate that EDI documents, such as 310 and 320 , sent from providers, such as 170 and 180 , comply with payers' companion guides, such as companion guide 1 410 and companion guide 2 420 and the rules of the associated implementation guide. [0041] Process [0042] The following discussion explains an embodiment of a process to validate the compliance of EDI documents with companion guides. As shown in FIG. 2 , the process employs the following main steps: Step 1000 in FIG. 2 —Setting up a system to validate the compliance of EDI documents with companion guides; Step 2000 in FIG. 2 —Employing an organizer of CG rules 520 to add rules to the inventory of rules 620 ; Step 3000 in FIG. 2 —Using the organizer of CG rules 520 to create CG profiles 610 ; Step 4000 in FIG. 2 —Validating an EDI document 310 . [0047] Setting Up a System to Validate the Compliance of EDI Documents with Companion Guides [0048] An embodiment of a process for setting up a system on server 100 , shown in FIG. 1 , to validate the compliance of EDI Documents with companion guides is shown in FIG. 3A and FIG. 3B . [0049] Step 1002 in FIG. 3A —Creating a validation application 900 . [0050] A validation application 900 is a proprietary software program used to validate the compliance of an EDI document with a payer's companion guide 410 . For the data transfers in this process, validation application 900 uses a controller 190 . [0051] Step 1004 in FIG. 3 A—Setting up a portal Web page 200 . [0052] A portal Web page 200 is a Web page that payers can access to review and modify their CG profiles 610 , as explained below. [0053] Step 1006 in FIG. 3 A—Creating an organizer of CG (companion guide) rules 520 . [0054] An organizer of CG rules 520 is a proprietary software program that contains human-readable hierarchies of rules from companion guides and their associated implementation guide and that is used for efficiently creating CG profiles 610 for payers. [0055] Step 1008 in FIG. 3 A—Creating a rules analyzer 522 . [0056] A rules analyzer 522 is a proprietary software program used by the organizer of CG rules 520 to help analyze the content of companion guides 410 and 420 and to build an organizer of CG rules 520 . [0057] Step 1010 in FIG. 3 A—Employing a companion guide analyzer 540 . [0058] In an embodiment, a companion guide (CG) analyzer 540 is a human operator who uses the organizer of CG rules 520 and his or her own efforts to analyze companion guides 410 and 420 for common and different rules and uses this information to create and update the entries in the inventory of rules 620 . In another embodiment, a companion guide analyzer 540 may comprise a fully automated software program. [0059] Step 1012 in FIG. 3 A—Creating a profiles engine 560 . [0060] A profiles engine 560 is a proprietary software program used to create a current rule set 720 for a payer. [0061] Step 1014 in FIG. 3 A—Setting up a metadata storage 600 . [0062] A metadata storage 600 may comprise non-volatile storage used to store CG profiles 610 and an inventory of rules 620 . [0063] Step 1016 in FIG. 3 A—Creating CG profiles 610 . [0064] CG profiles 610 are one or more files 612 and 614 that indicate payers' companion guide rules and the associated implementation guide rules, providing pointers to the rules stored in the inventory of rules 620 , which is described below. [0065] Step 1018 in FIG. 3 B—Creating a runtime checker engine 700 . [0066] A runtime checker engine 700 is a proprietary software program used to validate an EDI document such as 310 by comparing it to the current rule set 720 and CG profile 612 for a payer's companion guide 410 . [0067] Step 1020 in FIG. 3 B—Creating an inventory of rules 620 . [0068] An inventory of rules 620 is a proprietary software program that contains all the rules defined by the organizer of CG rules 520 . [0069] Step 1022 in FIG. 3 B—Creating a rule set 720 . [0070] In an embodiment, a rule set 720 is an instance in a cache 710 that shows the current set of rules required by a payer's companion guide 410 . A rule set 720 is created by the profiles engine 560 the first time a CG profile 612 is accessed during the validation process and is used subsequently each additional time that CG profile 612 is accessed. Each time CG profile 612 is updated, a new rule set 720 is created, which becomes the current rule set. [0071] Step 1024 in FIG. 3 B—Employing an implementation guide 800 . [0072] An implementation guide 800 is a set of standard rules for EDI documents in an industry and is available from the WEDI Web site. [0073] Step 1026 in FIG. 3 B—Employing a controller 190 . [0074] A controller 190 is a software program that controls data transfers for validation application 900 . [0075] In other embodiments, these elements may be located separately in more widely dispersed systems involving multiple servers. Moreover, in another embodiment these elements could be located on a payer's server 170 , shown in FIG. 1 , and the validation process could be carried out by the payer and without a clearing house. [0076] Employing an Organizer of CG Rules 520 [0077] FIG. 4 shows an embodiment of a process for employing an organizer of CG rules 520 . [0078] Step 2002 in FIG. 4 —Downloading an implementation guide. [0079] In an embodiment, the clearing house at server 100 , shown in FIG. 1 , downloads an electronic copy of an implementation guide 800 for a specific industry, such as health care insurance, from the WEDI Web site. [0080] Step 2004 in FIG. 4 —Adding implementation guide rules to the organizer of rules 520 . The validation application 900 uses the CG analyzer 540 to add the rules from the implementation guide 800 to the organizer of CG rules 520 . For the example, if the implementation guide 800 contains 1000 rules, these 1000 rules will form the base content of the organizer of CG rules 520 . [0081] Step 2006 in FIG. 4 —Analyzing companion guides 410 , 420 . [0082] Subsequently, the clearing house at server 100 receives a copy of a companion guide 1 410 from payer server 1 170 in electronic form. Validation application 900 then uses the rules analyzer 522 and the companion guide analyzer 540 to analyze the contents of companion guide 410 for the following contents in comparison with the content of the organizer of CG rules 520 : [0083] Content not found [0084] Similar content [0085] Identical content [0086] For example, companion guide 1 410 may contain 10 new rules not covered in the 1000 rules from the implementation guide 800 . The rules analyzer 522 and the companion guide analyzer 540 thus add the 10 new rules to the organizer of CG rules 520 . The current organizer of CG rules 520 then contains 1010 rules. [0087] Later, the clearing house at server 100 receives a copy of companion guide 2 420 from payer server 2 180 in electronic form. Validation application 900 then uses the rules analyzer 522 and the companion guide analyzer 540 to analyze the contents of companion guide 2 420 in comparison with the current contents of the organizer of CG rules 520 . For example, companion guide 2 420 may use only five of the ten new rules found in companion guide 1 410 and two new rules in addition. The rules analyzer 522 and the companion guide analyzer 540 thus add the two new rules from companion guide 2 420 , so that the current organizer of CG rules 520 contains 1012 rules. The same process continues with any additional companion guides that the clearing house at server 100 receives. [0088] Example—Entities with Common, Similar, and Unique Rules [0089] The following example illustrates one embodiment of a rules analyzer portion of the current invention. [0090] In this example, there are 600 entities designated as e 1 , e 2 , e 3 e . . . e 600 . Each entity has about 200 rules. Entity e 1 has 200 rules, entity e 2 has 195 rules, entity e 3 has 202 rules, and e 600 has 200 rules. [0091] The table below shows a small portion of the approximately 120,000 rules set from all entities and all rules. The first column “reference” is used for discussion of this example. The second column “rule” is designated as e i r j where “i” represents an entity and “j” represents a particular rule. [0000] Reference Rule Description 1 e 1 r 1 X > 50 2 e 1 r 2 Y = ‘abc’ . . . 200 e 1 r 200 AA = 1800 201 e 2 r 1 X > 50 202 e 2 r 2 Y = ‘def’ . . . 395 e 2 r 195 BB = 2000 396 e 3 r 1 X > 50 397 e 3 r 2 Y = ‘ghi’ . . . 597 e 3 r 202 Z = 100 . . . 119,801 e 600 r 1 X > 50 119,802 e 600 r 2 Y = ‘rstuv’ . . . 119,999 e 600 r 199 Z = 100 120,000 e 600 r 200 CC = 2100 [0092] In this example, the number of rules can be dramatically decreased to facilitate rules checking and update functions. [0093] Expressing the Rules in a Neutral Format [0094] The rules are first put into a neutral format that is machine readable so that they can be further processed. [0095] Classifying and Categorizing the Rules [0096] Many of the rules are “common” for two are more entities, such as reference numbers (1, 201, 396, 119801) and (597, 119999). [0097] Many rules are “similar” where the rule structure is the same, but the values differ, such as (2, 202, 397, 119802). [0098] Rules which are not common or similar are “unique”, such as (200, 395, 120000). [0099] By grouping the rules according to common, similar, and unique rules, the number of entries may be reduced from 120,000 to perhaps less than 50,000 rules. The table below shows a grouping of rules where the “Ref” column is for discussion of the example. [0100] In the table, Ref A is for a common rule shared by entities e 1 , e 2 , e 3 , and e 600 . [0101] Ref B is for a common rule shared by entities e 3 and e 600 . [0102] Ref C is for a similar rule of entities e 1 , e 2 , e 3 , and e 600 . [0103] Ref D, E, and F are for unique rules of entities e 1 , e 2 , and e 600 , respectively. [0104] This arrangement is one of many different ways to compile the rules in a rules analyzer. Once the rules are compiled, then all rules for an entity can be determined, such as by a column in the table below. The table also provides an improved method of updating rules to provide a current rule set. For instance if reference rule 202 (e 2 r 2 ) changed from Y=‘def’ to Y=‘lmnp’, the single entry at Ref C may be changed to update the table. [0000] Entity Ref Desc e 1 e 2 e 3 . . . e 600 A X > 50 * * * * B Z = 100 * * C Y ‘abc’ ‘def’ ‘ghi’ ‘rstuv’ D AA 1800 E BB 2000 F CC 2100 [0105] Step 2008 in FIG. 4 —Storing the rules. [0106] The organizer of CG rules 520 stores in the inventory of rules 620 all the rules it has identified. [0107] After its initial creation, the organizer of CG rules 520 can thus serve as a dynamic base for efficiently analyzing all new companion guides sent to the clearing house at server 100 , so that programmers do not have to manually create an entirely new set of rules for each new companion guide but only have to add the rules not previously covered. Moreover, the organizer of CG rules 520 may be sent to other servers for use with other systems. [0108] In other embodiments the clearing house at server 100 can receive hard copy companion guides in hard copy format and scan them into electronic format. [0109] In addition, multiple organizers of CG rules 520 may be created from the implementation guides and companion guides of separate industries, for example the health insurance and financial industries. [0110] Using the Organizer of CG Rules to Create CG Profiles [0111] After the organizer of CG rules 520 has been created, the organizer of CG rules 520 efficiently creates a CG (companion guide) profile such as 612 for each companion guide that has been analyzed through the process described above. CG profile 612 identifies all the rules employed by its associated companion guide 410 and is stored in metadata storage 600 . [0112] After a CG profile 610 has been created, the associated payer can use the portal Web page 200 to update the CG profile 610 . [0113] It is important to note that CG profile 612 contains pointers to those rules stored in the inventory of rules 620 that are used in companion guide 410 and not the actual code for the rules. Take, for example, the case where companion guide 1 410 contains 10 new rules in addition to the 1000 rules from the implementation guide 800 . CG profile 612 then would contain pointers to the code for Rule 1 , Rule 2 , etc.,—all the way to Rule 1010 , which is stored in the inventory of rules 620 . [0114] Continuing the example given above, companion guide 2 420 uses the 1000 rules of implementation guide 800 , only five of the ten new rules found in companion guide 1 410 , and two new rules in addition. The corresponding CG profile 614 for companion guide 2 412 may then contain pointers to the code for Rule 1 , Rule 2 , etc,—all the way to Rule 1000 , for Rules 1005 - 1010 , and for Rules 1011 and 1012 , which is stored in the inventory of rules 620 . [0115] Thus, when subsequent content changes are made to the fields for rules contained in the implementation guide and companion guides, the organizer of CG rules 520 can be used to easily and efficiently update the rules stored in the inventory of rules 520 without having to update individual CG profiles, whose pointers remain accurate. This makes the process of managing the large number of rules, and the changing nature of the rules, associated with implementation guides and companion guides much more manageable. [0116] Validating an EDI Document [0117] FIG. 5 shows an embodiment of a process for using a rule set 720 to validate an EDI document 310 . [0118] Step 5002 in FIG. 5 —Check the payer identification code. [0119] After an EDI document such as 310 reaches the clearing house at server 100 , the runtime checker engine 700 reads the payer identification code in the EDI document 310 and checks metadata storage 600 for a current rule set 720 for the payer. [0120] In an embodiment, a rule set 720 is a file stored in cache 710 , which shows the current set of rules required by a payer's companion guide 410 . A rule set 720 is created by the profiles engine 560 the first time a CG profile 612 is accessed during the validation process and is used subsequently each additional time that CG profile 612 is accessed. Each time a CG profile 612 is updated, the profiles engine 560 creates and stores a new rule set 720 for the CG profile 612 , and that new set becomes the current rule set 720 . [0121] Step 5004 in FIG. 5 —Document matches payer's rule set? [0122] The runtime checker engine 700 then attempts to validate the EDI document 310 by comparing it to the current rule set 720 for a payer's companion guide 410 . [0123] Step 5006 in FIG. 5 —Send to payer. [0124] If the EDI document 310 matches the rule set 720 , the validation application 900 validates the EDI document 310 and sends it to the payer 170 . [0125] Step 5008 in FIG. 5 —Return to provider. [0126] If the EDI document 310 does not match the rule set 720 , the validation application 900 invalidates the EDI document 310 and sends it back to the provider 150 . [0127] Computer System Overview [0128] FIG. 6 is a block diagram that illustrates a typical computer system 1400 , well known to those skilled in the art, representing a server 100 , shown in FIG. 1 , on which embodiments of the present invention can be implemented. This computer system 1400 , shown in FIG. 6 , comprises a network interface 1402 that provides two-way communications through a wired or wireless link 142 to a wired or wireless communications network 130 that uses any applicable communications technology. For example, the network 130 can comprise a public telephone network, a wireless network, a local area network (LAN), and any known or not-yet-know applicable communications technologies, using correspondingly applicable links. The network 130 in turn provides communications with one or more host computers 150 and, through the Internet 1424 , with one or more servers 103 . [0129] The network interface 1402 is attached to a bus 1406 or other means of communicating information. Also attached to the bus 1406 are the following: [0130] a processor 1404 for processing information; [0131] a storage device 1408 , such as an optical disc, a magneto-optical disc, or a magnet disc, for storing information and instructions; [0132] main memory 1410 , which is a dynamic storage device such as a random access memory (RAM) that stores information and instructions to be carried out by processor 1404 ; [0133] a bios 1412 or another form of static memory such as read only memory (ROM), for [0134] storing static information and instructions to be carried out by processor 1404 ; [0135] a display 1414 , such as a liquid crystal display (LDC) or cathode ray tube (CRT) for displaying information to user of the computer system 1400 ; and [0136] an input device 1416 , with numeric and alphanumeric keys for communicating information and commands to processor 1404 . In another embodiment a mouse or other input devices can also be used. [0137] The computer system 1400 is used to implement the methods of the present invention in one embodiment. However, embodiments of the present invention are not limited to specific software and hardware configurations. Computer system 1400 can receive data from computer 150 and server 103 through a network 130 such as the Internet, and appropriate links 142 , such as wired or wireless ones, and its network interface 1402 . It can of course transmit data back to computers over the same routes. [0138] Computer system 1400 carries out the methods of the present invention when its processor 1404 processes instructions contained in its main memory 1410 . Another computer-readable medium, such as its storage device 1408 , may read these instructions into main memory 1410 and may do so after receiving these instructions through network interface 1402 . Processor 1404 further processes data according to instructions contained in its storage device 1408 . Data is relayed to appropriate elements in computer system 1400 through its bus 1406 . Instructions for computer system 1400 can also be given through its input device 1416 and display 1414 . [0139] “Computer-readable medium” refers to any medium that provides instructions to processor 1404 , comprising volatile, non-volatile, and transmission media. Volatile media comprise dynamic memory, such as main memory 1410 . Non-volatile media comprise magnetic, magneto-optical, and optical discs, such as storage device 1408 . Transmission media comprise a wide range of wired and unwired transmission technology, comprising cables, wires, modems, fiber optics, acoustic waves, such as radio waves, for example, and light waves, such as infrared, for example. Typical examples of widely used computer-readable media are floppy discs, hard discs, magnetic tape, CD-ROMs, punch cards, RAM, EPROMs, FLASH-EPOMs, memory cards, chips, and cartridges, modem transmissions over telephone lines, and infrared waves. Multiple computer-readable may be used, known and not yet known, can be used, individually and in combinations, in different embodiments of the present invention. Alternate Embodiments [0140] It will be apparent to those skilled in the art that different embodiments of the present invention may employ a wide range of possible hardware and of software techniques. For example the communication between servers could take place through any number of links, including wired, wireless, infrared, or radio ones, and through other communication networks beside those cited, including any not yet in existence. [0141] Also, the term computer is used here in its broadest sense to include personal computers, laptops, telephones with computer capabilities, personal data assistants (PDAs) and servers, and it should be recognized that it could include multiple servers, with storage and software functions divided among the servers. A wide array of operating systems, compatible e-mail services, Web browsers and other communications systems can be used to transmit messages among servers. [0142] Furthermore, in the previous description the order of processes, their numbered sequences, and their labels are presented for clarity of illustration and not as limitations on the present invention.

Electronic data interchange (EDI) documents are validated by creating an inventory of all rules, dynamically adjusting the inventory based upon entity specific rules derived from a plurality of companion guides, determining a profile containing pointers to select rules in the inventory for each companion guide and storing the profile for each companion guide in a storage. A runtime checker can then be used to check a received EDI document with a corresponding rule set, forward the EDI document if the EDI document matches its current rule set and return the EDI document if the EDI document does not match its current rule set. EDI rules may be enforced, for example, by determining entity-specific rules from corresponding companion guides, by expressing each rule in a neutral and machine readable format, by classifying the rules and/or by creating an inventory of rules and pointers to entity-specific rules.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to cryogenic fluids. In another aspect, the present invention relates to methods and apparatus for processing, transporting and/or storing cryogenic fluids. In even another aspect, the present invention relates to receiving and/or dispensing terminals for cryogenic fluids and to methods of receiving, dispensing and/or storing cryogenic fluids. In still another aspect, the present invention relates to methods and apparatus for processing, transporting and/or storing liquified natural gas (“LNG”). 2. Description of the Related Art Interest in the use of liquified natural gas (LNG) as a fuel for motor vehicles has increased dramatically in recent years. Entire fleets of government and industrial vehicles have successfully been converted to natural gas. Some privately-owned vehicles have been converted as well. Congress has passed an energy bill that requires increased use of alternative fuels in government and private fleets. Several factors have influenced this increasing use of LNG as a fuel in motor vehicles. LNG is relatively inexpensive. In addition, it burns very cleanly, making it much easier for fleets to meet more restrictive pollution emission standards. And, in terms of reducing dependence on imported oil, natural gas is abundantly available in the United States. Most conveniently, natural gas is transported from the location where it is produced to the location where it is consumed by a pipeline. However, given certain barriers of geography, economics, and/or politics, transportation by pipeline is not always possible, economic or permitted. Without an effective way to transport the natural gas to a location where there is a commercial demand, the gas may be burned as it is produced, which is wasteful. Liquefaction of the natural gas facilitates storage and transportation of the natural gas (a mixture of hydrocarbons, typically 65 to 99 percent methane, with smaller amounts of ethane, propane and butane). When natural gas is chilled to below its boiling point (in the neighborhood of −260° F. depending upon the composition) it becomes an odorless, colorless liquid having a volume which is less than one six hundredth ( 1/600) of its volume at ambient atmospheric surface temperature and pressure. Thus, it will be appreciated that a 150,000 cubic meter LNG tanker ship is capable of carrying the equivalent of 3.2 billion cubic feet of natural gas. When LNG is warmed above its boiling point, it boils reverting back to its gaseous form. The growing demand for natural gas has stimulated the transportation of LNG by special tanker ships. Natural gas produced in remote locations, such as Algeria, Borneo, or Indonesia, may be liquefied and shipped overseas in this manner to Europe, Japan, or the United States. Typically, the natural gas is gathered through one or more pipelines to a land-based liquefaction facility. The LNG is then loaded onto a tanker equipped with cryogenic compartments (such a tanker may be referred to as an LNG carrier or “LNGC”) by pumping it through a relatively short pipeline. After the LNGC reaches the destination port, the LNG is offloaded by cryogenic pump to a land-based regasification facility, where it may be stored in a liquid state or regasified. If regasified, the resulting natural gas then may be distributed through a pipeline system to various locations where it is consumed. Of the known liquid energy gases, liquid natural gas is the most difficult to handle because it is so intensely cold. Complex handling, shipping and storage apparatus and procedures are required to prevent unwanted thermal rise in the LNG with resultant regassification. Storage vessels, whether part of LNG tanker ships or land-based, are closely analogous to giant thermos bottles with outer walls, inner walls and effective types and amounts of insulation in between. LNG storage tanks in the United States have heretofor been built mostly above the ground with some frozen pit facilities properly characterized as mostly above the ground. Most such tanks have been enclosed by a low rising earthen dike. Such dikes were sized and placed to enclose an area and volume at least as great as the storage capacity of the largest tank (if not all of the tanks) within the diked area. In addition, National Fire Protection Association (NFPA) guidelines (NFPA 59A, Para 108) for spill containment require impounding areas that hold the entire LNG capacity of the station in the event of a catastrophic spill. Furthermore, in accordance with NFPA guidelines, electrical controls must either be designed for explosion-proof conditions or be situated in designated safe areas outside of the impoundment area generally several hundred feet away. As explosion-proof controls are costly, the latter option is preferable. Thus, LNG to be regasified is generally pumped to a heating device situated outside the impoundment area several hundred feet away in a designated safe area. In spite of the presence of insulation, storage tanks will still cool if not freeze any ground in direct contact with the tank. Thus, an electrical heating element is placed in the ground to counter any cooling by the tank. A number of patents relate to the processing, transporting, and storing of LNG. U.S. Pat. No. 3,675,431 issued Jul. 11, 1972 to Jackson, discloses a partially submerged offshore storage tank for liquified energy gases. That patent described an insulated tank which was prefabricated, floated to a suitable offshore site and then sunk until its submerged base rested on the floor of the sea. An upper above-the-water domed metal cylinder extended from a concrete base. Insulation lined the interior of the tank. A thin and flexible membrane inside the insulation provided the required liquid tight interior lining of the tank. The insulation lining the submerged portion of the tank was said to be thinned, so that a layer of ice formed around the outside of the concrete base when the tank was filled with liquified gas. In accordance with the invention claimed in the patent, the ice layer supposedly acted as an outer seal for the submerged concrete. U.S. Pat. No. 3,727,418, issued Apr. 17, 1973, to Glazier, discloses an LNG storage facility having an insulated interior membrane. A balancing fluid, said to be isopentane (2-methyl butane) transferred hydrostatic pressure from surrounding ambient water to the LNG contents. U.S. Pat. No. 3,828,565, issued Aug. 13, 1974 to McCabe, discloses an insulated buoyant tank moved telescopically up and down in a larger receiver tank containing seawater, oil or other liquid in accordance with the quantity of LEG at atmospheric pressure stored therein from time to time. U.S. Pat. No. 4,041,722, issued Aug. 16, 1977, to Terlesky et al., discloses an impact resistant tank for storing cryogenic fluids, includes an inner metal tank having a metal side wall and a metal bottom and a concrete outer wall around the inner metal wall and having reinforcement therein to resist impact loads thereon, and to serve as a secondary containment for the cryogenic fluid. U.S. Pat. No. 4,209,267, issued Jun. 24, 1980, to Gnaedinger, proposes an improvement over the traditional earthen dike system around LNG storage tanks. Specifically, the storage system comprises a dike, impounding wall or drainage channel constructed of compacted earth, concrete, metal and/or other suitable substance surrounding an aboveground steel insulated tank used to store the liquefied gas. A drop shaft is used to communicate the diked area with an underground tunnel for temporary accumulation and subsequent safe disposal of liquid which has escaped from the storage tank. U.S. Pat. No. 4,374,478, issued Feb. 22, 1983, to Secord et al., discloses tanks for land storage of liquefied gas at low temperature at or above atmospheric pressure. The invention provides a storage tank of the kind in which the walls are formed by a multiplicity of connected, parallel, part-cylindrical lobes presenting outwardly convex arcuate surfaces, which is characterized in that the side and end walls thereof are provided by a single tier of connected lobes, in that said lobes extend in one common direction over the tank, in that the end walls of the tank comprise part-spherical knuckles closing off the ends of the part-cylindrical lobes, and in that a separating plate is provided at each lobe connection to strengthen the tank against internal pressure and to divide it into separate storage compartments. U.S. Pat. No. 5,682,750, issued Nov. 4, 1997, to Preston et al., discloses a portable self-contained delivery station for liquid natural gas (LNG) is provided on a movable skid frame and equipped with an instant on delivery system which may initiate LNG delivery immediately to a use vehicle. The skid is equipped with a spill containment feature such that the LNG may be contained in the event of spillage. A variable speed pump both controls LNG dispensing and saturation levels of the stored LNG. The pump is submerged in a sump tank which is separate from the bulk storage tank. The sump tank is flooded with an amount of LNG such that the pump is submerged. Delivery of LNG may thus occur instantly, without pre-cooling of the pump or associated meter. U.S. Pat. No. 6,640,554, issued Nov. 4, 2003, to Emmer et al., discloses a portable self-contained liquid natural gas (LNG) dispensing system is housed in a container featuring opposing side and end walls and a bottom panel. The container is divided into a ventilated portion and a covered portion. A roof is over the covered portion while the ventilated portion features an open top. A bulk tank positioned within the container contains a supply of LNG with a head space thereabove and a pump is submerged in LNG within a sump that is also positioned within the container and communicates with the bulk tank. The container is lined with stainless steel sheets to define a containment volume that is capable of holding the entire supply of LNG in the bulk tank. A vent valve communicates with the head space of the bulk tank and is positioned under the open top of the ventilated portion of the container. The electric controls are positioned on the lower portion of the end wall of the covered portion of the container so as to be located in accordance with the appropriate safety guidelines. All of the patents cited in this specification, are herein incorporated by reference. However, in spite of the above advancements, there still exists a need in the art for apparatus and methods for processing, transporting, and/or storing LNG. This and other needs in the art will become apparent to those of skill in the art upon review of this specification, including its drawings and claims. SUMMARY OF THE INVENTION It is an object of the present invention to provide for improved apparatus and methods for processing, transporting, and/or storing LNG. This and other objects of the present invention will become apparent to those of skill in the art upon review of this specification, including its drawings and claims. According to one embodiment of the present invention, there is provided an apparatus that includes a tank positioned on a foundation and a vaporizer in liquid communication with the tank. The vaporizer has a heat exchange medium inlet stream, and a heat exchange medium outlet stream. The heat exchange medium outlet stream is routed through the foundation. In a further embodiment of this embodiment, at least a portion but not all of the heat exchange medium inlet stream is routed through the foundation. In an even further embodiment of this embodiment, the system further comprises a containment wall surrounding the tank, with the vaporizer supported by the containment wall. In a still further embodiment, the system further comprises a containment wall surrounding the tank and defining a containment area between the tank and wall, with the vaporizer positioned within the containment area. In a yet further embodiment, the system comprises liquified natural gas contained within the tank. According to another embodiment of the present invention, there is provided an apparatus that includes a tank surrounded by a containment wall defining a containment area between the tank and wall, and a vaporizer in liquid communication with the tank. The vaporizer includes a heat exchange medium inlet stream, and a heat exchange medium outlet stream. The heat exchange outlet stream is routed to discharge into the containment area. According to further embodiments of this embodiment: (1) the tank is positioned on a foundation, the apparatus further comprising a blower positioned to intake from the containment area and to discharge through the foundation; (2) the vaporizer is supported by the containment wall; (3) the vaporizer is positioned in the containment area; and/or liquified natural gas is contained within the tank. According to even another embodiment of the present invention, there is provided an apparatus that includes a tank positioned on a foundation, and surrounded by a containment wall defining a containment area between the tank and wall, and a vaporizer in liquid communication with the tank. The vaporizer further comprises a heat exchange medium inlet stream, and a heat exchange medium outlet stream, with a first portion of the heat exchange outlet stream routed through the foundation, and a second portion of the heat exchange outlet stream routed to discharge outside the containment area. According to further embodiments of this embodiment: (1) the vaporizer is mounted on the containment wall; (2) the vaporizer is positioned in the containment area; (3) at least a portion but not all of the heat exchange medium inlet stream is routed through the foundation; and/or (4) liquified natural gas is contained within the tank. According to still another embodiment of the present invention, there is provided a method of vaporizing a cryogenic liquid contained within a tank positioned on a foundation. The method includes the steps of passing the cryogenic liquid from the tank to a vaporizer; introducing an inlet steam comprising heat exchange medium into the vaporizer to gasify the cryogenic liquid and cool the heat exchange medium; and, passing the cooled heat exchange medium through the foundation. According to further embodiments of this embodiment the method also includes: (1) passing at least a portion by not all of the inlet steam through the foundation; and/or (2) having the cryogenic liquid be liquified natural gas. According to yet another embodiment of the present invention, there is provided a method of vaporizing a cryogenic liquid contained within a tank supported by a foundation and surrounded by a wall defining a containment area between the tank and the wall. The method includes the steps of passing the cryogenic liquid from the tank to a vaporizer; introducing an inlet steam comprising a heat exchange medium into the vaporizer to gasify the cryogenic liquid and cool the heat exchange medium; and, discharging the cooled heat exchange medium stream into the containment area. According to further embodiments of this embodiment the method also includes: (1) passing at least a portion by not all of the inlet steam through the foundation; (2) blowing air from the containment area through the foundation; and/or (3) having the cryogenic liquid be liquified natural gas. According to even still another embodiment of the present invention, there is provided a method of vaporizing a cryogenic liquid contained within a tank supported by a foundation, and surrounded by a wall defining a containment area between the tank and the wall. The method includes the steps of passing the cryogenic liquid from the tank to a vaporizer; introducing an inlet steam comprising a heat exchange medium into the vaporizer to gasify the cryogenic liquid and cool the heat exchange medium; passing a first portion of the cooled heat exchange medium through the foundation; and, discharging a second portion of cooled heat exchange medium stream outside of the containment area. Further embodiments of this embodiment includes variations as shown herein for the other embodiments. These and other embodiments of the present invention will become apparent to those of skill in the art upon review of this specification, including its drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, it should be understood that like reference numbers refer to like members. FIG. 1 shows a prior art cryogenic storage tank 10 , having safety valve 13 and a suitable freestanding pipe tower 16 for supporting the required piping for filling 21 and piping for emptying 23 tank 10 , and schematically shows pump 25 for pumping LNG from tank 10 , and vaporizer 31 for vaporizing the LNG into natural gas. FIG. 2 shows a schematic representation of one non-limiting embodiment of cryogenic storage system 100 of the present invention and method of the present invention, showing cryogenic tank 10 , emptying liquid LNG line 23 , pump 25 , vaporizer 31 , and ground heater 22 . FIG. 3 shows a schematic representation of another non-limiting embodiment of cryogenic storage system 100 of the present invention, showing cryogenic tank 10 , containment wall 12 defining impoundment area 15 , emptying liquid LNG line 23 , pump 25 , and vaporizer 31 . FIG. 4 shows a schematic representation of even another non-limiting embodiment of cryogenic storage system 100 of the present invention, showing cryogenic tank 10 , containment wall 12 defining impoundment area 15 , emptying liquid LNG line 23 , pump 25 , and vaporizer 31 . FIG. 5 is a schematic of another non-limiting embodiment of cryogenic storage system 100 of the present invention, showing cryogenic tank 10 , containment wall 12 defining impoundment area 15 , emptying liquid LNG line 23 , pump 25 , and vaporizer 31 mounted on containment wall 12 . FIG. 6 is a schematic of another non-limiting embodiment of cryogenic storage system 100 of the present invention, showing cryogenic tank 10 , containment wall 12 defining impoundment area 15 , emptying liquid LNG line 23 , pump 25 , and vaporizer 31 mounted on support structure 32 and positioned within impoundment area 15 . DETAILED DESCRIPTION OF THE INVENTION While some descriptions of the present invention may make reference to liquified natural gas (“LNG”), it should be understood that the present invention is not limited to utility with LNG, but rather has broad utility with cryogenic fluids in general, preferably cryogenic fluids formed from flammable gases. The apparatus of the present invention will find utility for processing, storing, and/or transporting (i.e., including but not limited to, receiving, dispensing, distributing, moving) cryogenic fluids, a non-limiting example of which is liquified natural gas (“LNG”). The apparatus of the present invention includes cryogenic storage apparatus. The apparatus of the present invention also includes apparatus for cryogenic processing and/or transporting. The present invention will be explained by first making reference to the prior art. Referring first to FIG. 1 , there is shown a prior art cryogenic storage tank 10 , having safety valve 13 and a suitable freestanding pipe tower 16 for supporting the required piping for filling 21 and piping for emptying 23 tank 10 . Schematically shown are pump 25 for pumping LNG from tank 10 , and vaporizer 31 for vaporizing liquid LNG stream 23 into natural gas stream 23 G. Vaporizer 31 , shown with heating media inlet stream 35 A and heating media outlet stream 35 B, is situated outside the impoundment area several hundred feet away in a designated safe area. Vaporizer 31 may be any suitable heat exchange device, most commonly an open rack vaporizer or ambient air vaporizer. Completely surrounding tank 10 and defining impoundment area 15 is low rising containment dike 12 . As is well known in the prior art, and as shown in FIG. 1 , the height of containment dike 12 is significantly less than the height of tank 10 . The impoundment area (more accurately “volume”) 15 is defined between containment dike 12 and tank 10 , and is sized sufficient to hold the entire contents of tank 10 . The present invention will now be discussed by reference to FIGS. 2–4 , in which it should be understood that like reference numbers refer to like members. Referring now to FIG. 2 , there is shown one non-limiting embodiment of cryogenic storage system 100 of the present invention and method of the present invention, showing cryogenic tank 10 , emptying liquid LNG line 23 , pump 25 , vaporizer 31 , and ground heater 22 . In operation, pump 25 is engaged to pump liquid LNG to be vaporized through emptying line 23 to vaporizer 31 . Heat necessary to vaporize the LNG is provided by inlet line 35 A carrying the heat exchange medium (most commonly air or water). Vaporizer 31 is operated in such a manner that the cooled heat exchange medium stream 35 B still has sufficient heat to be used to warm the ground beneath tank 10 . Generally, this means that the cooled heat exchange medium is sufficiently above the freezing point of water to keep the ground thawed. Thus, cooled heat exchange medium then proceeds via outlet piping 35 B to be circulated beneath tank 10 forming heater 22 . Any suitable arrangement of piping may be utilized for heater 22 . For example, heat 22 piping may form a spiral pattern, or run beneath tank 10 in a back-and-forth manner, or any other suitable pattern or arrangement. While the simplest manner of forming heater 22 will be to form piping into a suitable patter or arrangement, it is also contemplated that specialized baffles, manifolds or other heat exchange equipment as is known to those of skill in the heat exchange art may be utilized. It should be understood that heater 22 may be used to completely replace the traditional electrical heaters used beneath LNG tanks, or may be used to supplement such traditional heaters. It should also be understood that it is not necessary to be vaporizing LNG in vaporizer 31 in order to operate heater 22 . As an alternative optional embodiment, optional piping 35 C can be provided to allow all or part of stream 35 A to by-pass vaporizer 31 , for those instances where more heat is required in heater 22 , or in those instances when vaporizer 31 is not vaporizing LNG. This optional piping can be utilized on the embodiments as shown in FIGS. 3 and 4 . With this embodiment, and those discussed below, rather than locate vaporizer 31 several hundred feet away from tank 10 , only to then pipe vaporizer outlet 35 B all the way back to tank 10 , optionally, it is preferred to locate vaporizer 31 as close to tank 10 as possible. As shown in FIG. 2 , one embodiment of the method of the present invention, includes pumping the cryogenic fluid away from the tank in which it is stored, vaporizing the cryogenic fluid with a heat transfer medium in a manner sufficient to forming a cooled heat transfer medium that is still above 32° F., and then contacting this cooled heat transfer medium with the ground beneath the tank. Optional method steps include a partial or full by-pass of the vaporizer. Referring now to FIG. 3 , there is shown another non-limiting embodiment of cryogenic storage system 100 of the present invention, showing cryogenic tank 10 , containment wall 12 defining impoundment area 15 , emptying liquid LNG line 23 , pump 25 , and vaporizer 31 . Unlike the low rising earthen containment walls of the prior art, containment wall 12 will generally be at least about 25% the height of tank 10 , preferably in the range of about 25% to about 75% the height of tank 10 , more preferably in the range of about 30% to about 50% the height of tank 10 . While not wishing to be limited to exact heights, for many existing tanks which are on the order of 100 ft high, wall 12 will be in the range of about 30 ft to about 50 ft high. With a higher containment wall 12 , it should be understood that containment wall 12 may be positioned closer to tank 10 while still defining an impoundment volume 15 sufficient to hold the contents of tank 10 . As in the above embodiment shown in FIG. 2 , pump 25 is engaged to pump liquid LNG to be vaporized through emptying line 23 to vaporizer 31 . Heat necessary to vaporize the LNG is provided by inlet line 35 A carrying the heat exchange medium (which in this embodiment is a gas, preferably air or an otherwise environmentally inert gas). In many instances, the cooled gas of outlet line 35 B is sufficiently cooler than the ambient air, for example, on the order of 20° F. to 40° cooler, that environmental concerns might not allow for its discharge directly back to the environment. To both use this cooled gas and to slightly heat it, cooled gas outlet line 35 B can be discharged into impoundment area 15 where it serves to cool impoundment area 15 and thereby improve the cooling efficiency of tank 10 . As a further optional embodiment, cryogenic cooling system 100 may further include blower 26 positioned to blow air from impoundment area 15 to be circulated in piping beneath tank 10 forming heater 22 and warming the ground beneath tank 10 . As discussed above, rather than locate vaporizer 31 several hundred feet away from tank 10 , only to then pipe vaporizer outlet 35 B all the way back to tank 10 , optionally, it is preferred to locate vaporizer 31 as close to tank 10 as possible. Preferably, vaporizer 31 , pump 25 and all related components are positioned within impoundment wall 12 . Referring now to FIG. 6 , there is shown a schematic of another non-limiting embodiment of cryogenic storage system 100 of the present invention, showing cryogenic tank 10 , containment wall 12 defining impoundment area 15 , emptying liquid LNG line 23 , pump 25 , and vaporizer 31 mounted on support structure 32 and positioned within impoundment area 15 . More preferably, rather than providing a separate support structure for vaporizer 31 , it is mounted on containment wall 12 as shown in FIG. 5 . Even more preferably, vaporizer 31 is mounted in a convenient position on containment wall 12 . As shown in FIG. 3 , another embodiment of the method of the present invention, includes pumping the cryogenic fluid away from the tank in which it is stored, vaporizing the cryogenic fluid with a heat transfer medium in a manner sufficient to forming a cooled heat transfer medium, and then discharging this cooled heat transfer medium into the impoundment area around the tank. Optional method steps include a partial or full by-pass of the vaporizer. Referring now to FIG. 4 , there is shown even another non-limiting embodiment of cryogenic storage system 100 of the present invention, showing cryogenic tank 10 , containment wall 12 defining impoundment area 15 , emptying liquid LNG line 23 , pump 25 , and vaporizer 31 . As in the above embodiments, pump 25 is engaged to pump liquid LNG to be vaporized through emptying line 23 to vaporizer 31 . Heat necessary to vaporize the LNG is provided by inlet line 35 A carrying the heat exchange medium (which in this embodiment is preferably a liquid, most preferably water or an aqueous solution). Vaporizer 31 is operated in such a manner that the cooled heat exchange medium stream 35 B still has sufficient heat for further uses. Thus, outlet piping stream splits into cooled heat exchange medium stream 38 , which is most likely heated and then recycled to vaporizer 31 , and cooled heat exchange medium stream 39 is circulated beneath tank 10 thru heater 22 , and then also most likely heated and then recycled to vaporizer 31 . Optionally, valves 42 and 41 may be provided to regulate streams 38 and 39 , respectively. Control of valves 42 and 41 may be manual, or by optional controller 55 , shown in communication with valves 42 and 41 by communication lines 53 and 52 , respectively (although wireless signals may also be utilized). As shown in FIG. 4 , even another embodiment of the method of the present invention, includes pumping the cryogenic fluid away from the tank in which it is stored, vaporizing the cryogenic fluid with a heat transfer medium in a manner sufficient to forming a cooled heat transfer medium, and then discharging a first portion of the cooled heat transfer medium outside the impoundment area around the tank, and contacting a second portion of the cooled heat transfer medium with the ground beneath the tank. It is anticipated, that cryogenic system 100 of the present invention may be incorporated into an LNG transportation system, most notably to store LNG at locations remote to the LNG plant while it awaits subsequent use or further transportation. For example, one or more cryogenic systems 100 make be incorporated into an LNG terminal that receives LNG from marine vessels, rail, truck, air, or other transport. The cryogenic storage system 100 of the present invention may also find utility when incorporated into an LNG plant, specifically for storing the output of an LNG plant. While the illustrative embodiments of the invention have been described with particularity, it will be understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and descriptions set forth herein but rather that the claims be construed as encompassing all the features of patentable novelty which reside in the present invention, including all features which would be treated as equivalents thereof by those skilled in the art to which this invention pertains.

A cryogenic fluid storage/processing system which includes a tank for storing the cryogenic fluid, and a containment wall surrounding the tank and defining an impoundment area. The system further includes a vaporizer for regasification of the cryogenic fluid. Piping is discharges the vaporizer heating medium into the impoundment area, and/or routes it beneath the tank to heat the ground beneath the tank. Further, the system provides for all liquid hydrocarbons to be contained within the impoundment area with the pumps inside and the vaporizers mounted on the containment walls.

RELATED APPLICATIONS [0001] This application is a continuation of International application PCT/DE2009 001752 filed on Dec. 14, 2009. FIELD OF THE INVENTION [0002] The present invention relates to a device for filling containers, in particular bottles or beakers with food products, in particular liquid to paste-like dairy and fat products, juices, waters and similar, including an upper main element, a lower main element and lateral elements connecting the upper and the lower main element, and a plurality of support elements which are moved on rollers in an endless manner through the device past operating stations along the upper main element, the lateral element and the lower main element, wherein the support elements include receivers for containers arranged transversal to the feed direction in series. BACKGROUND OF THE INVENTION [0003] A device of this type is known e.g. from EP 1 134 182. It is an automated filling device which fills food products like for example dairy products into beakers or bottles. Thus, the support elements also designated as cell plates run through the device in an endless manner while being supported at a chain. Typically the operating stations which sterilize, dry, fill and close the containers are arranged along the upper main element. Through a first lateral element, the support elements then run into the lower main element arranged below the upper main element and are fed again to the upper main element through a second lateral element. [0004] In most of the filling devices currently available in the market, the number of containers filled depends on the processing time of the slowest operating station of the chain. The chain feed is provided in a timed manner so that in a simple version, always those containers are treated which are jointly supported on a support element. However, there are also so-called double step devices in which the containers of two support elements are simultaneously treated at the operating stations. [0005] The chain drive technique is tried and tested and has been used reliably for a long time though it has substantial disadvantages. Initially there is the basic problem that the chain elongates during operations. Consequently, the distance measured in feed direction between the support elements and thus also between the containers supported by the support elements increases over time. This is problematic since dosing sterilization agents, blowing in drying air, filling the containers and also closing at particular operating stations requires a comparatively exact positioning of the containers. Consequently, centering devices are required for chain operated devices. [0006] The support elements are pulled through the device on sliding rails; furthermore a support that is approximately central in feed direction is required above a certain size of the support elements. The mass inertias that have to be overcome in combination with the movement velocities of the support elements through the device require strong and thus heavy chains. The drive wheels and motors are also sized accordingly. Thus, a device of this type includes very massive and heavy components. [0007] For quite a while, persons skilled in the art have discussed how to design a chainless drive for a device of this type. In this context, for example, the German utility model DE 210 79 U1 has been published. Herein, a lantern pinion teething is shown which directly engages the support elements and pushes the support elements through the device. Thus the lateral elements are configured as arcuate rail systems connecting the upper main element and the lower main element. The support elements are provided with spacers for moving through the lateral elements. [0008] From EP 1 495 A1 additional drive concepts are known through which the support elements, cell plate adjoining cell plate, can be pushed through a device of this type. Among other things, a worm drive conveyor is proposed in this context. [0009] Pushing the cell plates through the device has the essential advantage that a chain which has elongation problems can be omitted. As a matter of principle however, there remains the problem that excessive friction forces have to be overcome and typically a support that is central in feed direction is still required for the cell plates. Furthermore, also when pushing the cell plates through the device it is not assured that the distances of the support elements or containers in feed direction are constant. As a matter of principle there is the risk that contaminating particles collecting between the support elements, for example production residues, can add up to form considerable total deviations. [0010] Also though EP 1 495 997 A1 proposes for friction minimization to push the cell plates through the device on rollers, besides the recited summation errors, the problem remains that the support proposed for the cell plates therein cannot be used in the machine for filling bottles. Bottles are typically supported at the bottleneck when moved through the filling device. Thus, the support elements are approximately cut in halves along a row of container receivers. For inserting the bottles, the support element halves are lifted and are moved apart parallel to the feed direction. The bottle is typically inserted from above into the opening thus widened. Subsequent thereto, the support element halves are moved back into their starting positions and enclose the bottle neck. [0011] Besides the fact that splitting the support elements into support element halves augments the problem of summation errors and thus the problem of exact alignment of the support elements under the operating stations, EP 1 495 997 A1 does not permit the predescribed opening of the cell plates for inserting the bottles. BRIEF SUMMARY OF THE INVENTION [0012] Thus, it is an object of the invention to configure a device with a chainless drive and support elements supported on rollers so that an exact positioning of the containers at the operating stations is provided. [0013] The object is achieved by a device with the features of claim 1 , in particular with the characterizing features, according to which at least two support elements are arranged on a common frame and are run by the frame on rollers in an endless manner through the device. [0014] It is an essential advantage of the invention that at least two, preferably four support elements are arranged on a common frame and positioned relative to one another. Insofar the possible summation error through collecting contaminations between the support elements is reduced at least by a factor of 2; in an advantageous embodiment it is even reduced by a factor of 4. [0015] It is provided in a particularly preferred embodiment that the rollers are arranged at the common frames of the support elements and the frames are run through the rollers on running tracks through the device. [0016] The essential advantage here is in the maintenance of the rollers. In case of a roller defect, a support element unit can simply be removed and can be replaced by a unit provided with intact rollers. The roller replacement can then be performed subsequently thereto without having to stop production. [0017] It is furthermore provided that frames are connected with one another through connection elements at least during the movement of the support elements along the operating stations. [0018] The high acceleration during feeding, thus when moving the support elements on their frames in feed direction, due to the substantial friction reduction, can have the effect that the frames do not come to a standstill at the next operating station. This generates small clearances between the particular frames which causes considerable noise during machine operation when frames contact one another. Furthermore, jolts of this type introduce high levels of stress into materials. Coupling the frames to one another, besides facilitating controlled acceleration, also provides controlled braking and positioning of the frames relative to the operating stations. Thus, a device with connected frames in this respect implements advantages of a chain drive. [0019] Thus, it is required that the connection of the frames with one another, besides the required fit clearance between the connection elements, has no clearance. [0020] In order to simplify moving the support elements on their frames from the upper main element into the lower main element, for example through a lifting device, it is provided that the connection elements arrange the frames at one another in horizontal direction; however a relative vertical movement of two adjacent frames relative to one another disengages the connection. [0021] In order to facilitate clean coupling and decoupling of the frames at one another and in order to simultaneously provide a connection of the frames with one another that essentially doesn't have any clearance, it is provided that the connection elements respectively include a groove with concave sidewalls and a respective coupling member, wherein the coupling member of a first connection element is inserted without clearance in the groove of a second connection element between the apex lines of the concave groove sidewalls. [0022] In particular the concave sidewalls of the groove expand in upward direction and in downward direction like a funnel so that a clean insertion of the coupling member is provided. Simultaneously the coupling member is run through this geometry self-acting to the tightest location of the groove in the portion of the apex lines of the sidewalls where it is inserted without clearance. [0023] The geometry for connecting the frames supporting the support elements can be substantially improved in that the coupling member includes convex side lobes aligned parallel to the groove sidewalls, wherein an arrangement of the apex line of the concave groove sidewalls approximately at the same levels and of the convex coupling member sidewalls of intermeshing connection elements provides a connection of the frames with one another that is essentially without clearance. [0024] The support elements supported on frames form an essential prerequisite that the device according to the invention can also be used for filling bottles. Consequently, it is provided that the support elements are split in half along a row, that each support element half includes partial recesses, and that partial recesses oriented towards one another of adjacent support element halves jointly form a receiver for containers, and wherein the support elements are configured vertically raisable on the common frame and are laterally movable in raised position for opening the receivers for inserting the containers. [0025] Insofar only supporting the support element halves on a common frame facilitates opening and closing the support elements analogous to prior art chain driven devices. [0026] Besides exact alignment of the containers in feed direction, the so-called longitudinal centering, also an alignment transversal to the feed direction (transversal centering) has to be provided for correct operations of the device. [0027] In chain driven filling machines which pull the support elements through the machine, essentially a correct position of the chain suffices for the transversal orientation. [0028] In devices with a chainless drive in which the support elements are essentially pushed through the device like in EP 1 495 997 A1, each support element by itself has to be transversally centered. Thus it is an object of the invention to provide a technical device that is configured accordingly. [0029] The object is achieved by a device with the features of claim 10 in particular with the features of the body of claim 10 according to which the rollers include a centering device through which the support elements are oriented transversal to the feed direction. Thus, it is provided in particular that the rollers roll on rolling paths when the support elements are fed in an endless manner and rollers and rolling track interact in a centering manner. [0030] When the rollers through which the support elements are movable through the device include the centering device themselves, a continuous centering can be provided in a manner that is technically particularly simple. It is for example conceivable that the rollers for centering run in a groove or include a separate centering arm which is supported at a groove. [0031] It is particularly preferred, however, when the rollers center the support elements in a transversal manner by interacting with the running paths. This is provided in particular in that the cross-sectional contour of the running surfaces of the rollers forms the centering device by interacting with the running surface contour of the running tracks. [0032] This type of centering is provided through the feed movement itself and is therefore continuous and permanent. Should a support element, while being fed through the device, be pressed out of its transversally centered position, e.g. through a foreign object, the feed movement by itself already provides re-centering. The centering device is provided in a technically very simply manner and has low maintenance and low wear. [0033] In a particularly preferred embodiment, it is provided that the cross-sectional contour of the running surfaces of the rollers is approximately V-shaped and the running surface contour of the running tracks is cambered in a partial circle, wherein it is presumed that the running tracks are formed by a running bar that has a circular cross-section. [0034] However, also the geometric reversal is conceivable where the running path forms an approximately V-shaped groove in which the running rollers roll with a running surface that has a cross-section of a partial circle. [0035] As described supra, it is known in the art to increase the throughput of a filling device in that the containers of two support elements are simultaneously treated at the operating stations. Thus, in the prior art, two support element halves of two support elements are moved apart parallel to the transport direction. This also is called opening the cell plates. The bottles are moved from above through the open cell plates into the contact plane of the cell plates on the chain. Subsequently, the cell plate halves are moved back again until they contact the drive chain. This is called closing the cell plates. When closing the cells, the partial recesses of the support element halves envelop the bottle neck and support the bottle. [0036] Since the cell plates have to move very far apart in order to allow the bottle element to pass through, the bottles are not inserted into two directly adjacent support elements. Instead, always two cell plates are opened that are offset from a closed cell plate. During insertion of the bottles into the support elements, the bottles are supported in their positions by suction elements. [0037] Therefore, the prior art bottle feed device with the feed devices arranged above the upper main element and the suction elements arranged below the upper main element are configured rather complex. Eventually also the time requirement for the opening movement of the support element halves is detrimental since it limits the machine timing and thus the machine throughput. [0038] Thus, it is an object of the invention to provide a novel container feed device which facilitates a quicker opening movement of the support elements with substantial configuration simplification. [0039] The object is achieved by a device with the features of claim 16 , in particular with the features of the body of claim 16 according to which the container feed device feeds the containers from below to the support elements. [0040] Differently from the prior art, the inventors have recognized that it is a substantial configuration disadvantage of the prior art bottle feeds that the entire body of the bottle has to be passed through between the support elements in order to eventually support the bottleneck that has a relatively small diameter. This type of prior art bottle feed has the consequence that the necessary large opening width causes the opening time that limits the operating cycle. Furthermore this type of feed is also the reason that support element halves have to be moved apart which are not directly adjacent to one another but are offset by at least one support element. This causes a comparatively long extension of the bottle feed device in transport direction. Also, the comparatively long movement path of the suction elements stabilizing the bottles is caused by the bottle feed from above. [0041] Based on this the inventors have recognized that the container feed from below to the support elements has essential advantages. Since only the bottle neck still has to be inserted between the support element halves, the necessary movement space and the movement time for the opening support element halves is substantially reduced. Consequently, at least two directly adjacent support elements can be outfitted with bottles. The installation space necessary for the container feed device in feed direction is substantially reduced. Also the vertical movement space for the bottles can be substantially reduced. [0042] A device is particularly advantageous which is characterized in that the container feed device lifts the containers for inserting into the container receivers and the lifting process induces the opening movement of the support element halves. [0043] In order to provide a solution with a particularly simple configuration, the container feed device is joined with the device for opening the support element halves. Thus, it is provided that the vertical lifting movement through which the bottles are moved in a direction towards the support elements at least induces the opening movement. It is provided in particular that the container feed device includes a lifting device wherein the vertical movement of the lifting device impacting the support element halves causes the opening movement of the support element halves through raising the support element halves. [0044] In one embodiment in which the support element halves include support members which engage device side slotted links and control the opening movement of the support element halves, the container feed device is the container feed device which also causes the opening of the support element halves. For this only a vertical movement is necessary which raises the support element halves. Through the interaction of support members and slotted links, the vertical movement is transformed into an opening movement of the support element halves. [0045] Thus, it is particularly advantageous that raising the containers, in particular the bottles and the vertical movement of the lifting device for opening the support element halves can be provided through a common drive. [0046] For this purpose it is only necessary that the lifter is movement coupled with the platform but arranged so that it is movable relative to the platform. [0047] Eventually the present invention also relates to a method for feeding containers to a container filling device, in particular for bottles or beakers with food products, in particular liquid to paste-like dairy and fat products, juices, waters and similar, including an upper main element, a lower main element and lateral elements connecting the upper and the lower main element, a plurality of support elements which are moved on rollers in an endless manner through the device past operating stations along the upper main element, the lateral element and the lower main element, wherein the support elements include receivers for containers arranged transversal to the feed direction in series. [0048] This method achieves the object according to which the container feeding shall be simplified through the characterizing method steps: [0049] a) feeding support elements arranged on a platform with containers; [0050] b) moving the platform to a location of the device where the containers are inserted into the support elements; [0051] c) lifting the support element halves from its contact plane for performing the opening movement; [0052] d) lifting the containers into the contact plane of the support elements; [0053] e) lowering the support element halves into the contact plane for performing a closing movement and for safely supporting the containers in the container receivers. [0054] In a particular embodiment of the method, it is provided that a raising of the platform is performed for method step c) which raising brings a lifting device into contact with the support element halves, wherein the lifting device moves the support element halves into an open position through a vertical movement relative to the platform. [0055] It is furthermore provided that the lifting device is lowered for method step e). BRIEF DESCRIPTION OF THE DRAWINGS [0056] Additional advantages of the invention can be derived from the subsequent description of advantageous embodiments of the invention illustrated in drawing figures, wherein: [0057] FIG. 1 illustrates an overview of the device according to the invention; [0058] FIG. 2 illustrates a partial view of the device according to FIG. 1 ; [0059] FIG. 3 illustrates a perspective view of the support elements arranged at a frame; [0060] FIG. 4 illustrates a top view according to FIG. 3 ; [0061] FIG. 5 illustrates a perspective view from below of the frame according to FIG. 3 ; [0062] FIG. 6 illustrates a bottom view of the frame according to FIG. 3 ; [0063] FIG. 7 illustrates a sectional view of the frame according to section line VII in FIG. 6 ; [0064] FIG. 8 illustrates a partial view of the cut frame according to FIG. 7 ; [0065] FIG. 9 illustrates a perspective view of the frame according to FIG. 3 sitting on running rails; [0066] FIG. 10 illustrates a detail view of the connection element of a frame according to FIG. 3 ; [0067] FIG. 11 illustrates an interaction of roller and running rail; [0068] FIG. 12 illustrates a top view of a frame according to FIG. 3 ; [0069] FIG. 13 illustrates a sectional view of the frame according to section line XIII in FIG. 12 ; [0070] FIG. 14 illustrates a frame vertically cut parallel to the feed direction and equipped with containers; [0071] FIG. 15 illustrates an overview of a container feed device according to the invention; [0072] FIG. 16 illustrates a slotted link sliding block according to FIG. 15 ; [0073] FIG. 17 illustrates a vertical sectional view of the container feed device according to FIG. 15 transversal to the feed device; [0074] FIG. 18-20 illustrates a container feed device according to FIG. 15 in a vertical sectional view performed parallel to the feed device in different operating positions. DETAILED DESCRIPTION OF THE INVENTION [0075] A device for filling container with food products is overall designated with the reference numeral 10 in the figures. [0076] FIG. 1 illustrates the device 10 in its entirety. The filling device for the containers 10 includes an upper main element OT, a lower main element UT offset there from and two lateral elements ST. [0077] Along the arrow direction X the support elements that are not designated in more detail in FIG. 1 are supported along various operating stations 11 in the upper element OT so that it is transferable through a first lateral element ST into the lower element UT. In the lower element UT the support elements move in arrow direction Y to the second lateral element ST in order to be moved from there back into the upper main element OT. In this respect the support elements run through the device 10 in an endless manner. The operating stations 11 illustrated in FIG. 1 are in particular a sterilization- and drying unit 12 , dosing stations 13 , a cap placement station 14 and a cap screwing station 15 . [0078] FIG. 2 illustrates a top view of a partial section of the upper main element OT in which plural support elements 16 which are also designated as cell plates are arranged behind one another in feed direction. Each support element 16 includes a plurality of container receivers 17 arranged transversal to the feed direction X. Consequently the container receivers are arranged adjacent to one another in rows R. The container receivers of plural support elements 17 arranged behind one another in feed direction X form tracks B arranged parallel to the feed direction X. [0079] FIG. 3 illustrates a frame 3 which includes two longitudinal profiles 19 arranged offset from one another and parallel with respect to the feed direction X. The support elements 16 , four in this instance contact the longitudinal profiles 19 with their ends. In the present embodiment the support elements 16 include two support element halves 20 which are provided through splitting the support elements 16 approximately in half along a row R. The longitudinal profiles 19 are arranged at one another through transversal profiles 21 and furthermore carry support rollers 22 on which the frame 18 is run through the device 10 . The longitudinal profiles 19 form connection elements 23 and their ends, wherein the connection elements are subsequently described in more detail and through which plural frames 18 can be coupled with one another. [0080] From FIG. 4 which provides a top view of the frame illustrated in FIG. 3 the configuration is illustrated in more detail. Besides the components described supra support members 24 are provided at the ends of the support elements halves 20 arranged parallel to the feed direction X, wherein the support members 24 are used for controlling the opening movement of the support elements halves 20 . [0081] A bottom view of the frame 18 from below according to FIG. 3 is illustrated in FIG. 5 . From this illustration it is apparent that the transversal profiles 21 support a support rail 25 below the support elements 16 . The support rail 25 is arranged approximately central between the longitudinal profiles 19 of the frame 18 . The contact rail 25 is used for stabilizing the support elements 16 so that the support elements 16 due to their own weight or the weight of the filled container do not sag in the center. The transversal profile 18 as evident from this figure is configured as a T profile for static reasons. [0082] FIG. 6 illustrates the top view of the bottom side of the frame 18 . This figure is supplemented over FIG. 5 with the illustration of the position of the sectional plane VII along which the frame 18 according to FIG. 7 is vertically cut. [0083] From the sectional view of FIG. 7 it is initially evident that each roller 22 is rotatably arranged on a roller axis 26 . The roller axis 26 in turn is anchored in the longitudinal profile 19 of the frame. It is furthermore evident from FIG. 7 that the rollers 22 of the frame 18 contact running bars 27 of the device 10 . [0084] FIG. 8 illustrates a detail of the sectional view according to FIG. 7 . From this detail it is particularly evident that the roller 22 includes a circumferential V-shaped or roof shaped groove 28 . Consequently the cross section contour of the running surface 29 of the roller 22 is also approximately V-shaped. The running track configured as running bar 27 includes a circumferential cross section. The running surface 30 of the running bar 27 is formed by the surface portion oriented towards the roller 22 . As evident from FIG. 8 the running bar 27 with its running surface 30 is inserted into the V shaped groove of the roller 22 so that the running surfaces 29 and 30 contacts one another. [0085] The illustration of FIG. 9 illustrates a frame 18 which contacts the running bars 27 of the device 10 . The running bars 27 are arranged in the upper main element OT and in the lower main element UT so that the frames 18 with the support elements 16 are run on the running bars 27 through the device 10 in an endless manner. [0086] FIG. 10 illustrates a cut out detail based on which the configuration of the connection element 23 of the longitudinal profile 19 is described in more detail. The connection element 23 forms a portion of the longitudinal profile 19 and is respectively arranged at ends of the longitudinal profile 19 oriented towards an adjacent frame 18 . The connection element initially includes a vertically aligned groove 31 with approximately concave groove side walls 32 . Directly adjacent to the groove 31 the longitudinal profile 19 forms a coupling member 33 . The side lobes 34 of the coupling member 33 which side lobes are aligned parallel to the groove side walls 32 are configured convex. [0087] In the embodiment illustrated in FIG. 10 the groove 31 and the coupling member 33 are configured so that the concave groove side wall 32 adjacent to the coupling member 33 simultaneously forms the convex side lobes 34 of the coupling member 33 . The side lobe 34 oriented away from the groove simultaneously forms the face wall of the longitudinal beam 19 . The grooves 31 thus offset the coupling members 33 from the support elements 16 . It is appreciated that connection elements 23 oriented towards one another of adjacent frames 18 are configured in a mirror image to each other. [0088] The connection elements 23 of adjacent frames 18 engage one another during a movement along the upper and lower main component OT/UT. Adjacent frames 18 are connected with one another in this manner. Thus, the frames 18 that are moved in a timed manner through the device 10 can be accelerated and decelerated in a controlled manner. The coupling member 33 in its width measured in movement direction is sized in the portion of the apex lines of the convex side walls 34 so that it is essentially inserted into the groove 31 without clearance when the apex lines of the groove side walls 32 are approximately arranged in one plane with the apex lines of the side lobes 34 . This prevents excessive noise generation when accelerating and decelerating the frames 18 through a contact of connection elements 23 of adjacent frames 18 . [0089] The coupling of the frames 18 is separated in that adjacent frames 18 are moved vertically toward one another. Thus, the coupling elements 33 slide out of the grooves 31 . This vertical movement occurs when a frame 18 switches through the lateral element ST into the lower main element UT. [0090] Compared to the prior art in which the support elements 16 contact one another, arranging the support elements directly on the frames 18 has substantial advantages. In the first place the summation errors which lead to an erroneous faulty orientation of the support elements relative to the operating stations are reduced by a factor which corresponds to the number of the support elements 16 mounted on the frames. Summation errors of this type occur when contaminants adhere between adjacent support elements 16 according to the prior art. [0091] Since according to the invention plural support elements 16 are arranged on a frame 18 and are moved through the device 19 through the frames 18 the summation errors are substantially reduced. In the frames illustrated in the embodiment which support four support elements 16 the summation error is reduced by a factor of 4. [0092] In FIG. 11 the frame 18 that is run on the running rail 27 through the device 10 is illustrated in a perspective detail view. Special emphasis is put on a centering interaction of roller 22 and running rail 27 . The geometry of the running surfaces 29 is approximately V-shaped. The running surface 30 of the running rail 27 that has a cross section of a partial circle is disposed in the V-shaped groove of the roller which forms the roller side running surfaces 29 . It is evident that during a movement of the frame 18 through the device the running rail 27 as a matter of principle is arranged as deep as possible in the V-shaped groove of the roller 22 . In case no transversal forces occur the roller 22 is supported on the running rail 27 in a centered manner. Thus, a secure centering of the frames 18 is provided transversal to the feed direction which assures that the frames 18 , in particular the support elements 16 are correctly aligned with their container receivers 17 relative to the operating stations 11 . [0093] In case transversal forces caused by interferences impact the frames 18 during operation of the device wherein the transversal forces move the frames off center, the frames 18 immediately slide back into their correct positions due to the interfacing geometries of the running rails 27 and the rollers 22 after the transversal forces cease. [0094] FIG. 13 is a sectional view of the frame 18 along the longitudinal profile 19 according to sectional line XIII in FIG. 12 . The support element halves 20 are supported by the pins 35 , but they are moveably arranged in vertical direction on the frames. The pins 34 are inserted into bore holes 36 formed by the longitudinal profile 19 . The vertically moveable support of the support element halves 20 is required in particular for such filling devices 10 that are used for filling bottles. [0095] The bottles 37 engaged in FIG. 14 in the support elements 16 of a frame 18 include a bottle element 38 which transitions into a bottle neck 39 through a taper of the bottle diameter. The bottle neck 39 is provided with a radially protruding bottle collar 41 proximal to the bottle opening 40 . The bottles 37 are respectively inserted into a bottle receiver 17 with their bottle necks 39 . Thus, the bottle element 38 is arranged below the support elements 16 ; the bottle collar 41 contacts the support element 16 . For inserting the bottles into the bottle receiver 17 of the support elements 16 the invention proposes a novel container feed device which is designated with the reference numeral 50 in its entirety. This is subsequently described with reference to FIGS. 15-20 . [0096] FIG. 15 illustrates the container feed device 50 below a frame 18 provided with support elements 16 . As illustrated in the figures the support elements 16 respectively include two support element halves 20 which are respectively provided with partial recesses. Corresponding partial recesses oriented towards one another in pairs jointly form a container receiver 17 . [0097] The container feed device 50 includes a base plate 51 above which a bottle lifting plate 52 is arranged. Above the bottle lifting plate 52 a bottle support 53 is arranged in turn. On the bottle support plate 53 sleeve shaped bottle supports 54 are applied corresponding to the number of container receivers 17 . On the bottle support plate 53 furthermore support element lifting devices 55 are arranged. The bottles 37 to be inserted into the support elements 16 are arranged within the bottle holders 54 . In the portion of the container feed device 50 the device 10 includes slotted link sliding blocks 56 which are arranged parallel to the longitudinal beams 19 of the frame 18 and above the support elements 16 . The base plate 51 , the bottle lifting plate 52 and the bottle support plate 53 are vertically moveable through a drive that is not illustrated, wherein all of the plates 51 - 53 are vertically moveable relative to one another. [0098] According to FIG. 16 each of the sliding blocks 56 includes a slotted link 57 support which includes a vertically oriented insertion section 58 for the support members 24 of the support element halves 20 . Two respective adjacent slotted links 57 form a slotted link pair. The slanted sections 59 adjoining the vertical insertion section 58 of each slotted link pair are oriented opposite to one another. Therefore each slotted link pair includes slotted link guides 57 which are configured as mirror images relative to one another. [0099] In FIG. 17 the container feed device 50 is illustrated in a vertical sectional view, wherein the cutting plane is arranged transversal to the feed direction. From this sectional view it is apparent that the bottle support plate 53 in the portion of each bottle support 54 includes a cutout 60 . In each cutout 60 a bottle lifting device 61 arranged which is attached to the bottle lifting plate 52 . The bottle lifting device 61 includes a vertically aligned bottle lifting support 62 that is attached at one end to the bottle lifting plate 52 and a bottle lifting plate 63 attached at another end to the bottle lifting support 62 . The bottle 37 sits on the bottle lifting plate 63 with its bottle base. [0100] The function of the container feed device 50 is now described with reference to FIGS. 17-20 . In the portion of a container feeding which is arranged outside of the upper main element OT or the lower main element UT at the device the bottle supports 54 of the container feed device 50 are loaded with bottles 37 . Then the container feed device is moved into the portion of the upper main element OT or the lower main element UT where the bottles 37 are inserted into the support elements 16 . In the start position of the container feed device 50 illustrated in FIG. 17 the lifting devices 55 contact the bottom side of the support element halves 20 . The bottle necks 39 are arranged below the support elements 16 . [0101] FIGS. 18-20 illustrate a vertical sectional view through a frame 18 and a container feed device 50 arranged there under, wherein the sectional plane is arranged parallel to the feed direction. Contrary to the starting position of the container feed device which is illustrated in FIG. 17 the opening position is illustrated in FIG. 18 . The unit including the bottle lifting plate 52 and the bottle lifting plate 53 has been vertically raised relative to the base plate 51 . The lifting devices 55 not illustrated in FIG. 18 consequently move the support elements 20 also in vertically upward direction. The support element halves 20 leave the operating portion of the pins 35 . Simultaneously support members 24 engage the vertical insertion sections 58 of the slotted ink sliding blocks 56 . Subsequently the support members 24 move into the slanted sections 59 of the slotted links 57 which transform the vertical movement of the support element halves 20 into a lateral movement. Consequently the support element halves 20 of a support element 16 are offset from one another which widens the container receivers 17 . Thus, the support element halves 20 are moved from their contact plane A, E (the plane in which they contact the longitudinal beam 19 ) into the opening plane OE. Widening the container receivers 17 or the lateral movement of the support element half 20 controlled by the slotted links is evident in particular from their positions relative to the transversal profile 21 . While the transversal profiles 21 are arranged in the sectional view of FIG. 13 between two support elements 16 the adjacent support element halves 20 of two support elements 16 cover the transversal profiles 21 when they are arranged in the opening plane OE. [0102] It can be furthermore derived from FIG. 18 that the bottle necks 39 with their bottle collars 41 have a smaller diameter d than the widened container receivers 17 with its opening width D. [0103] Through the joint vertical movement of bottle lifting plate 52 and the bottle support plate 53 the bottle necks 39 move into the contact plane AE. This provides that the bottle collars 41 are arranged above the contact plane AE. Overall the unit including bottle lifting plate 52 and bottle support plate 53 was moved in vertically upward direction by the distance between contact plane AE and the opening plane OE of the support elements halves 20 . [0104] FIG. 19 illustrates the bottle insertion position of the container feed device 50 . As evident in comparison with FIG. 18 the bottle lifting plate 52 in order to reach this position was moved vertically upward relative to the bottle support plate 53 . Through the bottle lifting devices 61 coupled with the bottle lifting plate 52 the bottles 37 are also moved vertically upward, wherein the bottle lifting devices 61 penetrate the bottle holders 54 . Through the vertical movement of the bottle lifting plate 52 the bottle necks 39 are moved into the opening plane OE of the support element halves 20 . Thus the bottle colors 41 are arranged above the support element halves 20 . [0105] FIG. 20 illustrates the closed position of the container feed device 50 . The unit including bottle support plate 53 and bottle lifting plate 52 moves downward in its entirety relative to the base plate 51 in order to reach the closed position in FIG. 20 . The support element halves 20 supported on the lifting devices 55 not illustrated herein follow the downward movement. Thus, the slotted link guide 57 in which the support members 54 are supported provides the closing movement of the support element halves 20 which is opposite to the opening movement. After the closing movement is completed the support element halves 20 are placed into the contact plane AE again. The lateral reverse movement of the support element halves 20 in turn is evident from the positions of the support element halves relative to transversal profiles 21 . The transversal profiles 21 are now arranged at the same levels between the support element halves 20 of two adjacent support elements 16 . The performed relative downward movement is evident from the comparison of FIGS. 19 and 20 and the distance between the upper opening 64 of the bottle supports 54 and the transversal profile 19 . [0106] After completion of the closing movement the bottle lifting plate 52 is lowered far enough so that the bottle lifting plates 63 are again arranged in the plane of the bottle support plate 53 . Subsequently the container feed device 50 is lowered far enough so that the bottle supports 54 release the bottles 37 . [0107] It is evident that the container feed device 50 described supra is also useable as a container extraction device when the movement path is reversed. In this case FIG. 20 forms the starting position. The bottles 37 are inserted into the bottle holder 54 . The bottle lifting device 61 already supports the bottle base. Differently from FIG. 19 the unit including bottle support plate 53 and bottle lifting plate 52 is moved vertically upward so that the lifting devices 55 not illustrated in FIG. 20 but contacting the bottom side the support element halves 20 move the support element halves in vertically upward direction. Due to the engagement of the support members 24 into the sliding link guides 57 a lateral movement of the support element halves 20 and thus an opening of the container receivers 17 is provided. Subsequently thereto and transitioning to FIG. 18 the bottle lifting plate 52 moves downward relative to the bottle support plate 53 . The bottles are consequently lowered relative to the support element halves 20 . A subsequent movement of bottle lifting plate 52 and bottle support plate 53 by the same amount downward relative to the base plate 51 also moves the lifting devices 55 downward which are not illustrated in FIG. 18 . After the movement of the lifting device the support element halves 20 follow and thereafter the support element halves which are guided by the slotted link guides 57 close again. After the closing movement the container extraction device is in the position illustrated in FIG. 17 relative to the frame 18 , wherein the position was described therein as a starting position of the container feed device 50 . In order to complete the extraction process the container extraction device now has to leave the extraction location in the upper or lower main element. The bottles are removed from the bottle supports 54 by another device that is not described in more detail and the bottles are assembled into interconnections for subsequent transportation. [0108] In summary initially a solution was presented in which the support elements 17 for the containers 37 which are run on rollers 22 through the support device 10 can be centered transversal to the feed direction. The centering is configured in a particularly simple manner through a form locking engagement of the roller 22 and the running rail 27 . [0109] Furthermore a frame 18 was presented on which the support elements 16 are moveable through the device 10 wherein the support elements are arranged in groups. This is a considerable improvement with respect to the alignment of the support elements 16 in feed direction since the support elements 16 are pushed through the device 10 , support element 16 adjacent to support element 16 , which substantially reduces the possible summation error through contaminations between the support elements 16 . Furthermore frames 18 according to the invention facilitate a coupling to one another which facilitates a controlled acceleration and deceleration. [0110] Eventually a new container feed device 50 is disclosed which is also suitable to be used as a container extraction device. It is an essential advantage of the container feed device 50 to reduce the opening travel of the support element halves 20 due to the container feed to the support element 16 from below. Consequently directly adjacent support elements 16 can be simultaneously fed with containers 37 . Furthermore it is possible compared to the double step machines known from the prior art to provide more than two support elements 16 simultaneously with containers 37 while only requiring acceptable installation space. Consequently the throughput and also the cost effectiveness of a filling device 10 can be substantially increased. REFERENCE NUMERALS AND DESIGNATIONS [0111] 10 device [0112] 11 operating station [0113] 12 sterilization- and drying unit [0114] 13 dosing station [0115] 14 cap placement station [0116] 15 cap screwing station [0117] 16 support elements [0118] 17 container receivers [0119] 18 frames [0120] 19 longitudinal profiles of 18 [0121] 20 support element halves [0122] 21 transversal profile of 18 [0123] 22 rollers of 18 [0124] 23 connection elements of 19 [0125] 24 support members [0126] 25 support rail [0127] 26 roller axis [0128] 27 running bar [0129] 28 V-shaped or roof shaped groove of 22 [0130] 29 running surface of 22 [0131] 30 running surface of 27 [0132] 31 groove [0133] 32 groove side wall of 31 [0134] 33 coupling member [0135] 34 side lobes of 33 [0136] 35 pin [0137] 36 bore hole [0138] 37 bottle [0139] 38 bottle element [0140] 39 bottle neck [0141] 40 bottle opening [0142] 41 bottle collar [0143] 50 container feed device [0144] 51 base plate [0145] 52 bottle lifting plate [0146] 53 bottle support plate [0147] 54 bottle support [0148] 55 lifting device [0149] 56 slotted link sliding blocks [0150] 57 slotted link guide [0151] 58 vertical insertion section of 57 [0152] 59 slanted section [0153] 60 cut out of 53 [0154] 61 bottle lifting device [0155] 62 bottle lifting device support [0156] 63 bottle lifting device plate [0157] 64 upper opening of 54 [0158] AE contact plane [0159] OE opening plane [0160] OT upper main element [0161] UT lower main element [0162] ST lateral element [0163] R series of container receivers 17 of a support element 16 [0164] B tracks of container receiver 17 [0165] X movement direction of the support elements in upper main element [0166] Y movement direction of the support elements in the lower main element

A device for filling containers, in particular bottles and beakers with food products, in particular with low viscosity to pasty dairy and fat products, juices, waters and similar, comprising: an upper main element, a lower main element and lateral elements connecting the upper main element and the lower main element; and a plurality of support elements which are endlessly supported on rollers through the device past operating stations along the upper main element, the lateral element and the lower main element, wherein the support elements include receivers for containers which receivers are arranged in series transversal to a feed direction, wherein at least two support elements are arranged on a common frame and are run by the frame on rollers through the device in an endless manner.

RELATED APPLICATIONS [0001] This application claims the priority benefit under 35 U.S.C. § 119(e) of Provisional Application No. 60/645,581, filed on Jan. 18, 2005 and Provisional Application No. 60/656,832, filed Feb. 24, 2005, the entire contents of these applications are hereby incorporated herein by reference in their entirety BACKGROUND OF THE INVENTION [0002] The present invention relates to equipment for chemical processes. In particular, the present invention relates to equipment for growing a thin film in a reaction chamber. Description of the Related Art [0003] There are several vapor deposition methods for depositing thin films on the surface of substrates. These methods include vacuum evaporation deposition, Molecular Beam Epitaxy (MBE), different variants of Chemical Vapor Deposition (CVD) (including low-pressure and organometallic CVD and plasma-enhanced CVD), and Atomic Layer Epitaxy (ALE), which is more recently referred to as Atomic Layer Deposition (ALD). [0004] ALD is a known process in the semiconductor industry for forming thin films of materials on substrates such as silicon wafers. ALD is a type of vapor deposition wherein a film is built up through self-saturating reactions performed in cycles. The thickness of the film is determined by the number of cycles performed. In an ALD process, gaseous precursors are supplied, altematingly and repeatedly, to the substrate or wafer to form a thin film of material on the wafer. One reactant adsorbs in a self-limiting process on the wafer. A subsequent reactant pulse reacts with the adsorbed material to form a single molecular layer of the desired material. Decomposition may occur through reaction with an appropriately selected reagent, such as in a ligand exchange or a gettering reaction. In a typical ALD reaction, no more than a molecular monolayer forms per cycle. Thicker films are produced through repeated growth cycles until the target thickness is achieved. [0005] In an ALD process, one or more substrates with at least one surface to be coated and reactants for forming a desired product are introduced into the reactor or deposition chamber. The one or more substrates are typically placed on a wafer support or susceptor. The wafer support is located inside a chamber defined within the reactor. The wafer is heated to a desired temperature above the condensation temperatures of the reactant gases and below the thermal decomposition temperatures of the reactant gases. [0006] A characteristic feature of ALD is that each reactant is delivered to the substrate in a pulse until a saturated surface condition is reached. As noted above, one reactant typically adsorbs on the substrate surface and a second reactant subsequently reacts with the adsorbed species. As the growth rate is self-limiting, the rate of growth is proportional to the repetition rate of the reaction sequences, rather than to the temperature or flux of reactant as in CVD. [0007] To obtain self-limiting growth, vapor phase reactants are kept separated by purge or other removal steps between sequential reactant pulses. Since growth of the desired material does not occur during the purge step, it can be advantageous to limit the duration of the purge step. A shorter duration purge step can increase the available time for adsorption and reaction of the reactants within the reactor, but because the reactants are often mutually reactive, mixing of the vapor phase reactants should be avoided to reduce the risk of CVD reactions destroying the self-limiting nature of the deposition. Even mixing on shared lines immediately upstream or downstream of the reaction chamber can contaminate the process through parasitic CVD and subsequent particulate generation. SUMMARY OF THE INVENTION [0008] To prevent the vapor phase reactants from mixing, ALD reactors may include an “inert gas valving” or a “diffusion barrier” arrangement in a portion of a supply conduit to prevent flow of reactant from a reactant source to the reaction chamber during the purge step. Inert gas valving involves forming a gas phase, convective barrier of a gas flowing in the opposite direction to the normal reactant flow in the supply conduit. See T. Suntola, Handbook of Crystal Growth III, Thin Films and Epitaxy, Part B: Growth Mechanisms and Dynamics, ch. . 14, Atomic Layer Epitaxy, edited by D. T. J. Hurle, Elsevier Science V. B. (1994), pp. 601-663, the disclosure of which is incorporated herein by reference. See especially, pp. 624-626. Although such prior art arrangements have been successful in preventing vapor phase reactants from mixing, there is still room for improvement. In particular, experimental studies have indicated that within the reactor chamber there are dead pockets and/or recirculation cells that are difficult to purge. Accordingly, a portion of previous reactant pulse may remain in the reaction chamber during the subsequent reactant pulse. This may disadvantageously lead to CVD growth within the reaction chamber and on the substrate itself. CVD growth within the reaction chamber may disadvantageously lead to increased particle emissions. [0009] A need therefore exists for an improved reactor design which is easier to purge and eliminates or significantly reduces dead pockets in which reactants may remain after a purging step. [0010] Accordingly, one embodiment of the present invention comprises an atomic deposition (ALD) thin film deposition apparatus that includes a deposition chamber configured to deposit a thin film on a wafer mounted within a space defined therein. The deposition chamber comprises a gas inlet that is in communication with the space. A gas system is configured to deliver gas to the gas inlet of the deposition chamber. At least a portion of the gas system is positioned above the deposition chamber. The gas system includes a mixer configured to mix a plurality of gas streams. A transfer member is in fluid communication with the mixer and the gas inlet. The transfer member comprising a pair of horizontally divergent walls configured to spread the gas in a horizontal direction before entering the gas inlet. [0011] Another embodiment of the present invention comprises an atomic layer deposition (ALD) thin film deposition apparatus that comprises a deposition chamber configured to deposit a thin film on a wafer mounted within a space defined therein. The deposition chamber includes a gas inlet that is in communication with the space. The deposition chamber further comprising a sealing portion that includes a sealing surface. A susceptor is configured to support the wafer within the space. The susceptor configured to move vertically with respect to the deposition chamber between a first position in which the susceptor seals against the sealing surface and a second, lower position in which the susceptor no longer seals against the sealing surface. In the first position, a vertical distance between the interface between the sealing surface and the susceptor and the wafer positioned on the susceptor is less than about 2 millimeters. [0012] Another embodiment of the present invention comprises a substrate support for processing semiconductor substrates. The substrate support comprises a top surface with a recess. The recess is configured such that the top surface of the substrate support only contacts the substrate along an edge portion of the substrate. [0013] Another embodiment of the present invention comprises an deposition (ALD) thin film deposition apparatus that includes a deposition chamber configured to deposit a thin film on a wafer mounted within a space defined therein. The deposition chamber comprises a gas inlet that is in communication with the space. The deposition chamber further comprises a sealing portion that includes a sealing surface. A susceptor is configured to support the wafer within the space. The susceptor is configured to move vertically with respect to the deposition chamber between a first position in which the susceptor seals against the sealing surface and a second, lower position in which the susceptor no longer seals against the sealing surface. The susceptor is configured such that when the wafer is positioned on the susceptor in the first position, the leading edge of the wafer, with respect to gas flow, is positioned further from the sealing surface as compared to the trailing edge of the wafer. [0014] These and other objects, together with the advantages thereof over known processes and apparatuses which shall become apparent from the following specification, are accomplished by the invention as hereinafter described and claimed. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1A is front, top and left side a perspective view of an atomic layer deposition (ALD) device. [0016] FIG. 1B is a bottom, back and left side perspective view of the ALD device from FIG. 1A . [0017] FIG. 2 is a cut-away perspective of the ALD device of FIG. 1 , cut along lines 2 - 2 . [0018] FIG. 3 is a perspective view of the gas distribution system within the ALD device of FIG. 1A (partially visible in FIG. 2 ). [0019] FIG. 4 is a top plan view of the reactant gas lines coupled to an upstream member of the mixer assembly of the gas distribution system from FIG. 3 showing a buffer region in each reactant gas line. [0020] FIG. 5 is a schematic cross-sectional view through a portion of the gas-distribution system and reactor chamber of the ALD device of FIG. 1A . [0021] FIG. 6 is a perspective view of a portion of a modified embodiment of a gas distribution system that is coupled to a top plate of a reaction chamber within an ALD device. [0022] FIG. 7 is a top plan view of the gas distribution system of FIG. 6 . [0023] FIG. 8 is a top plan view of the top plate of FIG. 6 with the gas distribution system removed. [0024] FIG. 9 is a cross-sectional view taken along line 9 - 9 of FIG. 7 . [0025] FIG. 9A is an enlarged view of a portion of FIG. 9 . [0026] FIG. 10 is a schematic illustration of a susceptor, a substrate and a bottom plate of a reactor within the ALD system of FIG. 1 . [0027] FIG. 11 is a cross-sectional view similar to FIG. 9 but also illustrating a susceptor and bottom plate of the ALD device. [0028] FIG. 12 is a partial top perspective view of the susceptor and bottom plate of FIG. 11 . [0029] FIG. 13 is a top perspective view of the susceptor of FIG. 11 rotated 180 degrees. [0030] FIG. 14 is a cross-sectional view taken through line 14 - 14 of FIG. 13 and further illustrating a substrate positioned on the susceptor. [0031] FIG. 15 is a schematic cross-sectional illustration of an edge portion of an embodiment of a lift pin and susceptor arrangement. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0032] FIG. 1A is a perspective view of an embodiment of an ALD device 100 . The ALD device 100 comprises a top member 110 , a bottom member 112 , and a front member 118 , which together form a portion of a housing for the ALD device 100 . In the embodiment illustrated in FIG. 1A , an upper heater 114 extends through the top member 110 . The upper heater 114 is configured to maintain the temperature in the upper portion of the ALD device 100 . Similarly, a lower heater 116 extends through the bottom member 112 . The lower heater is configured to maintain the temperature in the lower portion of the ALD device 100 . [0033] The front member 118 , which serves as a gate valve, of the ALD device 100 covers an opening 120 . A dashed line outlines the opening 120 in FIG. 1A . Once the front member 118 is removed, the opening 120 can receive a wafer to be processed by the ALD device 100 . In this way, the received wafer is placed in a deposition chamber within the ALD device 100 . Once processing is complete, the wafer can be removed from the deposition chamber via the same opening 120 . [0034] An ALD control system (not shown) is configured to control the ALD device 100 during processing of the wafer. For example, the ALD control system can include a computer control system and electrically controlled valves to control the flow of reactant and buffer gases into and out of the ALD device 100 . The ALD control system can include modules such as a software or hardware component, such as a FPGA or ASIC, which performs certain tasks. A module may advantageously be configured to reside on the addressable storage medium of the computer control system and be configured to execute on one or more processors. [0035] FIG. 1B is a perspective view of the ALD device 100 showing the bottom member 112 . The ALD device 100 further comprises a set of couplings 102 ( a ), 102 ( b ), 104 ( a )-( d ). In this exemplary configuration, ALD device 100 includes four separate reactant vapor sources. Two of these reactant vapor sources are connected to the ALD device 100 via couplings 102 ( a ), 102 ( b ). These gas sources can be pressurized or not. These vapor sources can be, for example, solid sublimation vessels, liquid bubblers or gas bombs. The third and fourth reactant vapor sources are connected to the ALD device 100 via couplings 104 ( b ), 104 ( c ). [0036] In one embodiment, each reactant vapor source has an associated inert gas source, which can be used to purge the reactant vapor lines after pulsing the reactant. For example, the inert gas sources that are associated with the reactant vapor sources connected to couplings 102 ( a ) and 102 ( b ) can be connected to couplings 104 ( a ) and 104 ( d ), respectively. The inert gas sources associated with the reactant vapor sources connected to couplings 104 ( b ) and 104 ( c ) can also connected to couplings 104 ( b ) and 104 ( c ), respectively. These inert gas sources can be pressurized or not. These inert gas sources can, be, for example, noble or nitrogen gas sources. The ALD control system (not shown) controls one or more valves to selectively allow or prevent the various gases from reaching the ALD device 100 . [0037] The ALD device 100 can be configured to deposit a thin film on the wafer when the wafer is inserted in the deposition chamber. In general, the ALD device 100 can receive a first reactant gas via one of the couplings 102 ( a ), 102 ( b ) or one of the couplings 104 ( b ), 104 ( c ). The ALD device 100 can also receive inert gas via the couplings 104 ( a )- 104 ( d ). In one embodiment, the inert gas enters the deposition chamber with the first reactant gas to adsorb no more than a monolayer of the first reactant on the wafer. By switching the appropriate valves (not shown), the flow of the first reactant gas is stopped preferably via an inert gas valving (IGV) arrangement and the deposition chamber and the gas lines are then purged with the inert gas from couplings 104 ( a ), 104 ( b ), 104 ( c ), and 104 ( d ). After the deposition chamber and gas lines are purged, the deposition cycle is continued with one or more of the other reactant gases. In one embodiment, the reactants from alternated pulses react with each other on the substrate or wafer surface to form no more than a single monolayer of the desired product in each cycle. It should be noted that variations of true ALD operation can increase deposition speed above one monolayer per cycle with some sacrifice to uniformity. [0038] In embodiments of the ALD device 100 , more than two reactant gases can be sequentially flowed (separated by periods of purging) through the ALD device 100 in each cycle to form compound materials on the wafer. Excess of each reactant gas can be subsequently exhausted via gas exit 106 ( FIG. 1B ) after adsorbing or reacting in the deposition chamber. The gas exit 106 may be connected to a vacuum pump to assist in the removal of the gases from the deposition chamber and provide a low pressure condition in the deposition chamber. Furthermore, the entire ALD device 100 can be pumped down to a low pressure by connecting any of the other couplings on the bottom member 112 to a vacuum pump. [0039] FIG. 2 is a cut-away section view of the ALD device 100 from FIG. 1A taken along line 2 - 2 . Within the ALD device 100 is a gas distribution system 202 (shown in more detail in FIG. 4 ) and a deposition chamber 200 , which is formed by a top or cover plate 314 , bottom or base plate 206 , susceptor or wafer support 204 and exhaust launder 316 . Located on upper and lower sides of the gas distribution system 202 and the deposition chamber 200 are one or more reflector plates 208 , 210 . The ALD device 100 further includes a wafer support 204 , a wafer support heater 216 , and a thermal switch 218 . [0040] The wafer support 204 is located within the ALD device and is configured to support a substrate or wafer during the deposition process. The wafer support 204 can be adapted to rotate within the deposition chamber 200 . The wafer support heater 216 can be configured to heat the wafer support 204 . The thermal switch 218 can be provided on the top member 110 . The thermal switch 218 can be configured to monitor the temperature of the top member 110 . It will be understood that the system 100 includes other temperature sensor and control mechanisms to maintain various surfaces of the system at desired temperatures. [0041] The illustrated embodiment includes upper reflector plates 208 that provide a thermal barrier between the upper portion of the gas distribution system 202 and the top member 110 . Similarly, lower reflector plates 210 provide a thermal barrier between the lower portion of the deposition chamber 200 and the bottom member 112 . The reflector plates 208 and 210 are also used to assist in radiatively heating the deposition chamber within a low pressure environment. As illustrated in FIG. 2 , the upper heater 114 is coupled to coils 212 which extend through the upper reflector plates 208 . The coils 212 are configured to provide heat through radiation to the upper portion of the gas distribution system 202 . Similarly, the lower heater 116 is coupled to coils 214 which extend through the lower reflector plates 210 and heat the lower portion of the deposition chamber 200 . Alternatively, other heating systems can be employed. [0042] The gas distribution system 202 is configured to route reactant gases entering via the couplings 102 ( a ), 102 ( b ), 104 ( b ), 104 ( c ) and inert gases entering via couplings 104 ( a )-( d ) through the ALD device 100 (see FIG. 1B ). The gas distribution system 202 is further configured to selectively mix one or more of the inert gases entering via couplings 104 ( a )-( d ) with one of reactant gases entering via couplings 102 ( a ), 102 ( b ), 104 ( b ), 104 ( c ) during a given pulse. The resulting mixture enters the deposition chamber 200 . After each pulse, the gas distribution system 202 exhausts any unreacted reactant and inert gases from the deposition chamber via gas exit 106 , such as through purging. The term coupling is used to describe a gas flow connection between one or more gas lines. The locations of the couplings shown herein are for illustrative purposes only and can be located at different locations along a gas line. Moreover, a gas line associated with a given coupling can be configured to flow gas into or out of the gas distribution system 202 . As will be described below, the various couplings in the exemplary embodiments described herein are designated to flow gases into or out of the gas distribution system 202 . However, the invention is not limited to the exemplary embodiments disclosed herein. [0043] The order that the reactant gases are cycled through the ALD device 100 depends on the desired product. To minimize any interaction between one or more reactant gases prior to each gas entering the deposition chamber 200 , the inert gas entering via couplings 104 ( a )-( d ) is periodically cycled or continuously flowed through the ALD device 100 between pulses of the reactant gases. In this way, the inert gases purge the deposition chamber 200 . As will be explained below, various reactant gases and inert gases are systematically cycled through the ALD device 100 so as to form a deposit on the wafer inserted through the opening 120 . [0044] FIG. 3 is a perspective view of the deposition chamber 200 and the gas distribution system 202 from the ALD device 100 of FIG. 1A . The gas distribution system 202 comprises a plurality of gas lines, a mixer assembly 304 , a transfer tube 310 , and an intake plenum or manifold 312 . The deposition chamber 200 includes a cover plate 314 , a base plate 206 , and an exhaust launder 316 . The gas distribution system 202 is connected to the deposition chamber 200 at the intake plenum 312 [0045] As best seen in FIG. 4 , in this example, the plurality of gas lines include four reactant lines 300 , 303 , 309 , 315 and eight buffer lines 301 , 302 , 305 , 307 , 311 , 313 , 317 , and 319 . Each reactant line is coupled with two of the buffer lines. Reactant line 300 is coupled to buffer lines 301 , 302 . Reactant line 303 is coupled to buffer lines 305 , 307 . Reactant line 307 is coupled to buffer lines 311 , 313 . Reactant line 315 is coupled to buffer lines 317 , 319 . The gas distribution system 202 can include greater or fewer reactant lines and buffer lines depending on the configuration of the ALD device 100 . Moreover, each reactant line may or may not be coupled to two buffer lines. For example, one or more of the reactant lines may be coupled to the buffer lines while another reactant line is not. The reactant line that is not coupled to buffer lines could be shut off by other means. [0046] Each reactant gas line includes four couplings within the gas distribution system 202 . Reactant gas line 300 comprises couplings 300 ( a ), 300 ( b ), 300 ( c ), and 300 ( d ). Reactant gas line 303 comprises couplings 303 ( a ), 303 ( b ), 303 ( c ), and 303 ( d ). Reactant gas line 309 comprises couplings 309 ( a ), 309 ( b ), 309 ( c ), and 309 ( d ). Reactant gas line 315 comprises couplings 315 ( a ), 315 ( b ), 315 ( c ), and 315 ( d ). The couplings for each reactant gas line are described below. [0047] Coupling 300 ( a ) couples the reactant gas line 300 with the coupling 102 ( b ) that leads to a reactant source (see FIG. 1B ). Coupling 300 ( b ) couples the reactant gas line 300 with the buffer line 302 . Coupling 300 ( c ) couples the reactant gas line 300 with the buffer line 301 . Coupling 300 ( d ) couples the reactant gas line 300 with the mixer assembly 304 . [0048] Coupling 303 ( a ) couples the reactant gas line 303 with the coupling 104 ( b ) that leads to another reactant source (see FIG. 1B ). Coupling 303 ( b ) couples the reactant gas line 303 with the buffer line 307 . Coupling 303 ( c ) couples the reactant gas line 303 with the buffer line 305 . Coupling 303 ( d ) couples the reactant gas line 303 with the mixer assembly 304 . [0049] Coupling 309 ( a ) couples the reactant gas line 309 with the coupling 104 ( c ) that leads to another reactant source. (see FIG. 1B ). Coupling 309 ( b ) couples the reactant gas line 309 with the buffer line 313 . Coupling 309 ( c ) couples the reactant gas line 309 with the buffer line 311 . Coupling 309 ( d ) couples the reactant gas line 309 with the mixer assembly 304 . [0050] Coupling 315 ( a ) couples the reactant gas line 315 with the coupling source 102 ( a ) that leads to still another reactant source (see FIG. 1B ). Coupling 315 ( b ) couples the reactant gas line 315 with the buffer line 319 . Coupling 315 ( c ) couples the reactant gas line 315 with the buffer line 317 . Coupling 315 ( d ) couples the reactant gas line 315 with the mixer assembly 304 . [0051] Buffer lines 301 , 302 , 305 , 307 , 311 , 313 , 317 , and 319 comprise couplings 301 ( a ), 302 ( a ), 305 ( a ), 307 ( a ), 311 ( a ), 313 ( a ), 317 ( a ), and 319 ( a ), respectively. [0052] In the embodiment illustrated in FIGS. 3 and 4 , each coupling 301 ( a ), 305 ( a ), 311 ( a ), and 317 ( a ) provides a flow path into the gas distribution system 202 . The coupling 301 ( a ) couples the buffer line 301 with the coupling 104 ( a ) (see FIG. 1B ). The coupling 305 ( a ) couples the buffer line 305 with the coupling 104 ( b ) (see FIG. 1B ). The coupling 311 ( a ) couples the buffer line 311 with the coupling 104 ( c ) (see FIG. 1B ). The coupling 317 ( a ) couples the buffer line 317 with the coupling 104 ( d ) (see FIG. 1B ). [0053] Each coupling 302 ( a ), 307 ( a ), 313 ( a ), and 319 ( a ) provides a flow path between the gas distribution system 202 and the exhaust launder 316 via connectors 320 ( a )-( d ). Connector 320 ( a ) connects coupling 302 ( a ) with the exhaust launder 316 . Connector 320 ( b ) connects coupling 307 ( a ) with the exhaust launder 316 . Connector 320 ( c ) connects coupling 313 ( a ) with the exhaust launder 316 . Connector 320 ( d ) connects coupling 319 ( a ) with the exhaust launder 316 . These connections contribute to the operation of inert gas valving (IGV). [0054] In the embodiment shown in FIG. 3 , the reactant gas lines 300 , 303 , 309 , and 315 route reactant gases to the mixer assembly 304 . The buffer lines 301 , 305 , 311 , and 317 route inert gases to the mixer assembly 304 . The resulting mixture (one reactant at a time with an inert gas) flows through a transfer tube 310 to an intake plenum 312 . The intake plenum 312 distributes the mixture in a transverse direction with respect to the flow path through the transfer tube 310 . The mixture exits the intake plenum 312 into the deposition chamber 200 through the cover plate 314 . As shown in FIGS. 2 and 3 , the cover plate 314 lies adjacent to the base plate 206 and the two plates form a flow path there between for the mixture to flow over the substrate or wafer placed on the wafer support 204 . The base plate 206 and the cover plate 314 have substantially rectangular outer perimeters. [0055] While traversing the deposition chamber 200 , the mixture pulse saturates the surface of the substrate. Adsorption or reaction occurs between the current mixture and the surface of the substrate as left by the previous pulse may occur. After passing through the deposition chamber 200 , the mixture flows towards the exhaust launder 316 . The exhaust launder 316 is configured to collect excess of the mixture and any byproduct after the mixture has saturated the wafer. In an embodiment, a region within the exhaust launder 316 is at a lower pressure than the pressure in the deposition chamber 200 . A negative pressure source or vacuum can be in flow communication with the exhaust launder 316 and/or gas exit 106 to draw the mixture from the deposition chamber 200 . The exhaust launder 316 is in flow communication with the gas exit 106 . The collected mixture exits the deposition chamber 200 via the gas exit 106 . [0056] Still referring to FIG. 3 , the mixer assembly 304 includes an upstream member 306 and a downstream member 308 . The upstream member 306 is in flow communication with the reactant gas lines and the buffer lines. The upstream member 306 is configured to mix the reactant gas with the inert gas prior to the mixture entering the downstream member 308 . The downstream member 308 funnels the mixture between the upstream member 306 and the transfer tube 310 . the downstream member 308 is generally configured to minimize the tendency of the mixture to re-circulate within the downstream member 308 by continually reducing cross-sectional area of the flow path for the mixture. [0057] FIG. 4 is a top plan view of the reactant gas lines coupled to the buffer lines and the upstream member 306 of the mixer assembly. Between couplings 300 ( c ) and 300 ( b ), a buffer region 400 ( a ) is formed in the reactant gas line 300 . Between couplings 303 ( c ) and 303 ( b ), a buffer region 400 ( b ) is formed in the reactant gas line 303 . Between couplings 309 ( c ) and 309 ( b ), a buffer region 400 ( c ) is formed in the reactant gas line 309 . Between couplings 315 ( c ) and 315 ( b ), a buffer region 400 ( d ) is formed in the reactant gas line 315 . The buffer lines 301 , 305 , 311 , and 317 , which form flow paths into the gas distribution system 202 , couple to their associated gas lines downstream of couplings 300 ( b ) 303 ( b ), 309 ( b ), and 315 ( b ). In this way, gas entering via couplings 301 ( a ), 305 ( a ), 311 ( a ), and 317 ( a ) enters the reactant lines 300 , 303 , 309 , 315 downstream of the reactant lines couplings with the buffer lines 302 , 307 , 311 , and 319 . Fixed orifices can be placed at couplings 302 ( a ), 307 ( a ), 313 ( a ) and 319 ( a ). [0058] As seen in FIG. 3 , couplings 302 ( a ), 307 ( a ), 313 ( a ) and 319 ( a ) are in communication with the exhaust launder 316 . The orifices create a higher resistance path for the gases to flow to the exhaust launder 316 and bypass the deposition chamber 200 . In this way, during the pulse of a reactant gas, a small portion of the reactant gas entering via couplings 300 ( a ), 303 ( a ), 309 ( a ) or 315 ( a ) bypasses the deposition chamber and flows directly to the exhaust launder 316 . The restriction created by the orifice limits the amount of shunted reactant. During the purge step, at least a portion of the inert gas entering via couplings 301 ( a ), 305 ( a ), 311 ( a ), and 317 ( a ) creates a reverse flow towards couplings 300 ( b ) 303 ( b ), 309 ( b ), and 315 ( b ) to form the buffer regions 400 ( a )-( d ) within the reactant gas line. The buffer regions keep the reactant gases from diffusing into the reactor during the purge steps or during reactant flow of a reactant from one of the other reactant lines into the mixer assembly 304 . [0059] For example, during an ALD processing step, reactant gas flows through reactant line 300 towards the upstream member 306 of the mixer assembly. A small amount of this reactant gas is diverted to the buffer line 302 and out through coupling 302 ( a ) into the exhaust launder 316 . The amount of gas that is diverted to the buffer line is dependent of the size of the fixed orifice at coupling 302 ( a ). The size of the fixed orifice can be changed to divert more or less of the gas into the exhaust launder 316 . The remaining reactant gas flows through the buffer region 400 ( a ) to the coupling 300 ( c ). [0060] Inert gas may or may not be introduced through coupling 301 ( a ) to push the reactant gas into the upstream member 306 . If inert gas is introduced through coupling 301 ( a ), the inert gas joins the reactant gas at coupling 300 ( c ) and flows to the upstream member 306 . After the pulse step, the reactant gas is purged from the gas line. Purging of the gas line can be accomplished by, for example, shutting off the flow of the reactant gas from coupling 300 ( a ) and/or using the inert gas to impede the diffusion of any remaining reactant gas into the upstream member 306 . The shutoff valve can be located outside of the heated area and can be used to shut off the flow of the reactant gas. The inert gas can be introduced through coupling 301 ( a ) in an inert gas valving (IGV) process as described generally in U.S. patent publication number 2001/0054377, published on Dec. 27, 2001, the disclosure of which is hereby incorporated herein by reference. [0061] A first portion of the stream of inert gas flow enters the buffer region 400 ( a ) and flows upstream or backwards towards the coupling 300 ( b ). A second portion of the stream of gas flows downstream towards the upstream member 306 . The first portion exits the reactant line 300 at the end of the buffer region 400 ( a ) and enters the buffer line 302 . While the first portion is flowing through the buffer region 400 ( a ), the remaining reactant gas between the shutoff valve upstream of coupling 300 ( a ) and coupling 300 ( b ) is blocked from flowing or diffusing to the upstream member 306 without subjecting physical valves (which are remote) to the wear caused by high temperatures. The first portion forms a buffer or diffusion barrier (or inert gas valve) that impedes the flow of the reactant gas through the reactant line 300 to the mixer assembly 304 . By cycling the shutoff valve upstream of coupling 300 ( a ), the ALD control system is able to control between flowing and not flowing the inert gas in the buffer line 301 . In this way, the ALD control system is able to quickly control whether the reactant gas entering the reactant line 300 via coupling 300 ( a ) reaches the upstream member 306 . Furthermore, during the purge step and subsequent pulses of other reactant gases, the reactant gas in a “dead space” which is located between the shutoff valve upstream of the coupling 300 ( a ) and coupling 300 ( b ) can be kept from diffusing into the upstream member 306 . This may be advantageous for ALD since the different reactant gases are kept separated and only react on the surface of the substrate and not in the gas phase. [0062] Whether the reactant gas entering the gas distribution system 202 via the coupling 303 ( a ) reaches the upstream member 306 is similarly controlled by flowing a gas through the buffer line 305 and into the reactant line 303 at coupling 303 ( c ) and using a shutoff valve upstream of coupling 303 ( a ). A first portion of the gas entering the reactant line at coupling 303 ( c ) forms the buffer 400 ( b ). In this way, the first portion of the gas impedes the reactant gas entering via the reactant line 303 from entering the upstream member 306 . A second portion of the gas entering the reactant line at coupling 303 ( c ) flows away from the buffer region 400 ( b ) and towards the upstream member 306 . [0063] Whether the reactant gas entering the gas distribution system 202 via the coupling 309 ( a ) reaches the upstream member 306 is similarly controlled by flowing a gas through the buffer line 311 and into the reactant line 309 at coupling 309 ( c ) and using a shutoff valve upstream of coupling 309 ( a ). A first portion of the gas entering the reactant line at coupling 309 ( c ) forms the buffer 400 ( c ). In this way, the first portion of the gas impedes the reactant gas entering via the reactant line 309 from entering the upstream member 306 . A second portion of the gas entering the reactant line at coupling 309 ( c ) flows away from the buffer region 400 ( c ) and towards the upstream member 306 . [0064] Whether the reactant gas entering the gas distribution system 202 via the coupling 315 ( a ) reaches the upstream member 306 is similarly controlled by flowing a gas through the buffer line 317 and into the reactant line 315 at coupling 315 ( c ) and a shutoff valve upstream of coupling 315 ( a ). A first portion of the gas entering the reactant line at coupling 315 ( c ) forms the buffer 400 ( d ). In this way, the first portion of the gas impedes the reactant gas entering via the reactant line 315 from entering the upstream member 306 . A second portion of the gas entering the reactant line at coupling 315 ( c ) flows away from the buffer region 400 ( d ) and towards the upstream member 306 . [0065] As mentioned above, the first portions of the gases which enter the gas distribution system 202 via buffer lines 301 , 305 , 311 , and 317 and form the buffer regions 400 ( a )-( d ), exit via buffer lines 302 , 307 , 313 , and 319 . The gas exiting via buffer lines 302 , 307 , 313 , and 319 enter the exhaust launder 316 without passing through the deposition chamber 200 . In this way, the first portions of the inert gases bypass the deposition chamber 200 and are collected by the exhaust launder 316 downstream of the deposition chamber 200 . [0066] As mentioned above, the second portions of each gas which enter the gas distribution system 202 via buffer lines 301 , 305 , 311 , and 317 flow away from the buffer regions 400 ( a )-( d ) and enter the mixer assembly 304 . During reactant pulses, the second portions mix with one or more reactant gases from other reactant lines, which reach the mixer assembly 304 . Thus, the second portions flow through the deposition chamber 200 . Depending on the current ALD processing step, gases may periodically flow through their respective buffer lines 301 , 305 , 311 , and 317 . [0067] A reactant gas which the ALD control system desires to reach the deposition chamber 200 flows through its respective reactant line and into the mixer assembly 304 . The ALD control system forms buffer regions 400 in the reactant lines associated with the reactant gases which the ALD control system does not want to reach the deposition chamber 200 . The reactant gas which flows through the reactant line which does not have a buffer region 400 mixes with the second portions of the one or more inert gases which are simultaneously flowing through the other reactant lines and into the mixer assembly 304 . As explained above, the first portions of these gases form buffer regions in the other reactant lines and bypass the deposition chamber 200 . [0068] In one embodiment of the ALD device 100 which comprises four reactant gas lines, each reactant gas alternates in reaching the mixer assembly 304 . In this embodiment the reactant gas selected by ALD control system flows into the mixer assembly 304 while inert or “buffer” gas flows in the remaining three reactant lines. Continuing with this embodiment, the second portions of the gases flowing away from the buffer regions enter the mixer assembly 304 . The reactant gas of the pulse of interest then mixes with the inert gas of the second portions in the mixer assembly 304 . [0069] Further aspects and feature of the illustrated embodiment of the ALD device 100 can be found in U.S. patent application Ser. No. 10/841,585, filed May 7, 2004, the entirety of which is hereby incorporated by reference herein. [0070] FIG. 5 is a cross-sectional view of an embodiment of the transfer tube 310 , the plenum 312 , the top plate 314 and the bottom plate 206 described above. In particular, this figure shows the gas path from the mixer assembly 304 to the deposition chamber 200 . As shown in FIG. 5 , a shim 500 can be positioned between the plenum 312 and the top plate 314 . The shim 500 can be provided with a series of small injection holes 501 , which are provided to create sufficient back pressure in the plenum 312 to provide uniform flow across the deposition chamber 200 . However, as shown in FIG. 5 , this design can result in numerous recirculation cells 502 between the deposition chamber 200 and transfer tube 310 . Within these recirculation cells 502 , reactants from the subsequent pulses may collect. This may lead to CVD deposition within the deposition chamber 200 . Such CVD deposition is generally undesirable and can lead to particle buildup within the deposition chamber 200 . In addition, the shim 500 can produce a sharp contraction and then expansion of the gas flow. This can cause a sharp decrease in the temperature of the gas leading to condensation of the precursors in the gas stream. [0071] FIGS. 6-9A illustrate an embodiment of a transfer member 510 and top (cover) plate 514 . This embodiment seeks to reduce or eliminate the recirculation cells in the gas path by smoothing out the expansion and contraction of the gas flow. FIGS. 6 and 7 are top perspective and plan views of the transfer member 510 and the top plate 514 , respectively. FIG. 8 is a top plan view of the top plate 514 with the transfer member 510 removed. FIG. 9 is a cross-sectional view taken through line 9 - 9 of FIG. 7 and FIG. 9A is an enlarged view of a portion of FIG. 9 . [0072] As shown, the transfer member 510 forms a generally triangular shaped flow path that provides for gradual expansion of the gas from the mixer 304 . As best seen in FIGS. 8-9 , the transfer member 510 in the illustrated embodiment includes a first portion 518 that is generally adjacent to the mixer 304 and a second portion 520 that is generally adjacent an opening 522 in the top plate 514 . As shown in FIGS. 7 and 8 , the first portion 518 includes a pair of horizontally divergent walls 519 that expand in the horizontal direction at an angle A while the second portion 520 includes a pair of horizontally divergent walls 521 that expand in the horizontal direction at an angle B. In one embodiment, angle B is larger than angle A. In one embodiment, A is between about 5 to 45 degrees and B is between about 30 to 75 degrees. In the illustrated embodiment, the horizontally divergent walls are substantially straight. However, in a modified embodiment, the horizontally divergent walls can be curved, arced, continuously varying and/or segmented. In such an embodiment, the divergent walls can have average or mean divergent angle in the ranges described above. [0073] As shown in FIG. 9 , the transfer member 510 includes a top wall 523 which defines, in part, the height of a gas passage 511 defined by the walls 519 , 521 , the top wall 523 and a top surface 525 of the top plate 514 . In one embodiment, in the first portion 518 , the height hl of a gas passage 511 is preferably substantially constant. In the second portion 520 , the height h 2 of the gas passage 511 gradually decreases in the direction of the gas flow. In this manner, the volume of the second portion 520 adjacent the opening 522 can be reduced as compared to the plenum 312 of FIG. 5 . In addition, as the transfer member 510 expands in the horizontal direction, the height of the gas path is reduced to smooth out the expansion of the gas flow and increase back pressure which aid in spreading the gas flow across the chamber width. In the illustrated embodiment, the gas path defined by the passage 211 is generally parallel and opposite to the gas path in the deposition chamber 200 (see e.g., FIG. 11 ). [0074] Another advantage of the illustrated embodiment is that the gas passage 511 is formed between the transfer member 510 and a top surface 525 of the top plate 514 . This “clamshell” arrangement makes it easier to clean and refurbish the transfer member 511 as compared, for example, to a tube. Specifically, when removed from the top plate 514 , a large opening is created, which exposes the inner surfaces of the transfer member 511 facilitating cleaning and refurbishing. [0075] With reference now to FIGS. 8, 9 and 9 A, the top plate 514 is provided with the opening 522 to receive gas from transfer member 510 . In one embodiment, the opening 522 has a cross-sectional area that is substantially equal to the cross-sectional area (with respect to gas flow) of the end of the second portion 520 . In this manner, a smooth gas flow from the transfer member 510 into the top plate 514 is promoted. The opening 522 can have a generally elongated rectangular shape. See FIG. 8 . [0076] As shown in FIG. 9A , from the opening 522 , the top plate 514 includes a gradual contraction portion 524 that is connected to a narrowed region 526 . The contraction portion 524 includes a tapered or sloped wall 525 , which gradually reduces the cross-sectional area of the gas flow. In the illustrate embodiment, the narrowed region 526 comprises a generally rectangular slit of substantially constant cross-sectional area that extends in a generally vertical direction down through the top plate 514 . The narrowed region 526 is the portion of the gas flow between the mixer 304 and the deposition chamber 200 with the smallest cross-sectional area (with respect to gas flow). The narrowed region 526 is configured to create sufficient back pressure to provide uniform flow, particularly along the width w (see FIG. 8 ) of the deposition chamber 200 . The end of the narrowed 526 is in communication with an expansion portion 528 . The expansion portion 528 includes a slowed or tapered wall 529 that is configured to increase the cross-sectional area of the gas flow such that the gas gradually expands as it enters the deposition chamber 200 . The outlet 530 of the expansion portion 528 is in communication with deposition chamber 200 . [0077] Advantageously, the narrowed region 526 is vertically and horizontally elongated (a three-dimensional path) across the deposition chamber 200 (see FIG. 8 ) as compared to individual holes (a substantially two-dimension path) in the shim 500 described with reference to FIG. 5 . For example, as compared to the individual holes, recirculation cells and dead spaces in the x-plane (i.e. between holes) and in the z-direction (i.e., beneath the holes) are eliminated or reduced. Advantageously, this arrangement of the transfer member 510 , plenum 512 and top plate 514 also takes the gas from the mixer 304 and extends it over a portion of the deposition chamber 200 . The gas flow is then turned 180 degrees as it flows into deposition chamber 200 . [0078] Within the deposition chamber 200 , dead volumes and/or recirculation cells can also be formed. For example, FIG. 10 is a schematic illustration of the substrate S and susceptor plate 204 of the deposition chamber 200 of FIG. 1-4 . As shown, there exists a gap g 2 between the substrate S and the susceptor plate 204 and a gap g 1 between the susceptor plate 204 and the base plate 206 . In certain circumstances, these gaps g 1 , g 2 can be difficult to purge and may harbor recirculation cells and/or be dead volumes. [0079] FIG. 11 is a partial cross-sectional view of a modified embodiment of the bottom plate 600 and susceptor 602 of the deposition chamber 200 taken along a line similar to line 9 - 9 of FIG. 7 . FIG. 12 is a partial perspective view of the bottom plate 600 and susceptor 602 . As shown, in this embodiment, the base plate 600 has a sealing portion 604 with a thickness t. The lower surface 605 of the sealing portion 604 seals against the susceptor 602 to seal the reaction chamber. In one embodiment, the end 606 of the sealing portion 604 has a thickness t that is approximately equal to the thickness of the substrate positioned on the susceptor 602 . Depending on the thickness of the substrate, the sealing portion 604 can have a thickness in the range from about 0.5 to about 3 millimeters. In this manner, as the gas flows over the bottom plate 600 towards the substrate, the gas is only exposed to a shallow step, which has a depth approximately equal to the thickness of the substrate. This reduces the size of or eliminates recirculation zones and facilitates purging the deposition chamber 200 . [0080] Another advantage of the bottom plate 600 and susceptor 602 arrangement illustrated in FIGS. 11 and 12 is that the seal or contact surface between the bottom plate 600 and the susceptor 602 is elevated as compared the arrangement of FIG. 10 . For example, in the illustrated embodiment, the lower surface 605 of the sealing portion 604 and the substrate are positioned substantially at the same vertical elevation. In one embodiment, the difference in elevation between the lower surface 605 and the substrate is between about 0 to about 2 millimeters. This arrangement advantageously reduces the volume of the dead space between the substrate and the bottom plate 604 and prevents or reduces the formation of recirculation cells in the deposition chamber 200 . [0081] FIGS. 13 and 14 illustrates in more detail the susceptor 602 . FIG. 13 is a top perspective view of the susceptor 602 , which has been rotated 180 degrees with respect to the orientation shown in FIGS. 11 and 12 . FIG. 14 is a cross-sectional view of the susceptor 602 with a substrate positioned thereon. [0082] In this embodiment, the susceptor 602 is configured such that the substrate S can be positioned off-center with respect deposition chamber 200 . In this manner, the gap g 3 between the substrate and the interface between the susceptor 602 and the bottom plate 600 can be displaced further away from the leading edge (with respect to gas flow) of the substrate S. In general, the leading edge of the substrate is positioned near the inlet into the deposition chamber 200 as compared to a trailing edge of the substrate, which is positioned near on outlet (exhaust) of the deposition chamber 200 . [0083] In another embodiment, the substrate can be centered (or substantially centered) on the susceptor. In such an embodiment, the susceptor can be oversized to increase the distance between the interface between susceptor 602 and the bottom plate 600 and the edge of the substrate. In one embodiment, the susceptor 602 has a diameter that is at least about 10% greater than the diameter of the substrate. In another embodiment, this diameter of the susceptor is at least about 25% greater than the diameter of the substrate. In another embodiment, the diameter of the susceptor is between about 10% and about 25% greater than the diameter of the substrate. Such embodiments also provide for more space between the leading edge of the substrate and the interface between the susceptor and sealing surface. The oversized susceptor described above can also be used alone or in combination with the offset features described in this paragraph to provide even more space the leading edge of the substrate and the interface between the susceptor and sealing surface. [0084] Advantageously, for a susceptor of equivalent width and/or size, the gap g 3 between the leading edge of the substrate and the interface between the susceptor 602 and the bottom plate 600 can be increased. In this manner, any recirculation cells caused by discontinuities between the susceptor 602 and the bottom plate 600 are displaced further from the leading edge of the substrate S. Thus, in one embodiment, the center of the substrate positioned on the susceptor 602 is positioned asymmetrically and/or off-center with respect to the interface or seal between the susceptor 602 and the bottom plate 600 . In a modified embodiment, the susceptor can have a non-round or asymmetrical shape to further distance the leading edge of the substrate from discontinuities between the susceptor 602 and the bottom plate 600 . [0085] As shown in FIG. 11 , the susceptor 602 can include a plurality of pins 609 that extend from the top surface of the susceptor 602 to constrain or confine movement of the substrate on the susceptor. The pins 609 can replace shoulders or ridges (see e.g., the shoulder that creates the gap g 2 in FIG. 10 ) that are sometimes used to constrain or confine movement of the substrate. Such shoulders or ridges can disadvantageously create recirculation and/or dead zones. Thus, in one embodiment, a top area of the susceptor between the interface between the sealing surface and the susceptor is substantially flat and does not include such shoulders or ridges. Such an arrangement can eliminate or recirculation and/or dead zones. [0086] With continued reference to FIG. 13 and with reference to FIG. 14 , the susceptor can include a recessed region 610 , which is configured such that the substrate is only (or substantially only) contacted on its edges (see FIG. 14 ). This embodiment helps to reduce wafer curvature and/or susceptor doming from becoming problematic. In particular, wafer curvature and/or doming can cause a gap to form between the edge of the substrate and the susceptor. Gases can become trapped in this gap making purging inefficient and causing backside deposition. By contacting the substrate along its edges as shown in FIG. 14 , wafer curvature and/or doming will not cause a gap to form between the edge of the substrate S and the susceptor 602 . This eliminates or reduces the tendency for gases to become trapped between the substrate and the susceptor. In one embodiment, the recess region 610 has a depth between about 0.2 to 0.5 millimeters. In another embodiment, the substrate S and susceptor 602 are configured such that a continuous or substantially continuous seal is formed along the edge of the substrate S. [0087] With continued reference to FIG. 13 , the recess 610 can have a generally circular shape such that the seal between the susceptor 602 and the substrate is also generally circular. In addition, as shown, the center c of the recess 610 can be positioned “off-center” with respect to the outer edge of the generally circular susceptor 602 . In this manner, the leading (with respect to gas flow) edge of the substrate can be distanced from the sealing portion 604 of the bottom plate 600 as compared to the trailing edge as described above. This allows the wafer to be placed a greater distance from the recirculation cells in front of the wafer. Since the gas is swept across the wafer in a cross flow reactor, re-circulation cells on the rear seal between the susceptor and base plate do not affect deposition uniformity as much. [0088] FIG. 15 illustrates partial cross-sectional view of embodiment of an edge contact lift pin 620 that could be used in combination with the susceptor 602 described above. As shown, the pin 620 can include a pin head 622 that includes a notch 624 or beveled edge for securing the substrate S. The pin head 622 is configured to contact the edge of the substrate and lies generally at the interface between the susceptor 602 and the recess region 610 . The pin head 622 can be coupled to a pin shaft 626 , which extends through openings 628 in the susceptor. [0089] The pin 620 can be configured such that when the susceptor 602 is raised into the deposition chamber 200 , the pin head 622 becomes recessed within a recessed region 630 formed in the susceptor 602 . As the susceptor is lowered, the pin head 622 can be raised with respect to the susceptor 602 . For example, as described in co-pending U.S. patent application Ser. No. ______ filed on Jan.______, 2006 under Attorney Docket No. ASMEX.532A (the entirety of which is incorporated by reference herein), in one embodiment, to the raise the pin 620 from a “lowered” position seated in the recess 630 , the substrate is moved downward by a lifting mechanism. This downward movement causes the bottom surface the support pin 620 to contact a connector (not shown) positioned below the susceptor 602 . The contact of the pin 620 with the connector compresses a spring (not shown) surrounding a lower portion of the shaft 626 . As the spring is compressed while the susceptor 602 is moved downward, the spring attains a restoring force that will facilitate relative “lowering” of the pin 620 when the susceptor 620 is lifted next time. Accordingly, the combination of the spring and the platform or “floor” for downward pin movement provided by the connector permits the pin to remain relatively fixed while the susceptor 602 moves up and down, without requiring the pin to be fixed relative to the deposition chamber 200 . [0090] Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In addition, while a number of variations of the invention have been shown and described in detail, other modifications, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combine with or substituted for one another in order to form varying modes of the disclosed invention. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow.

An atomic deposition (ALD) thin film deposition apparatus includes a deposition chamber configured to deposit a thin film on a wafer mounted within a space defined therein. The deposition chamber comprises a gas inlet that is in communication with the space. A gas system is configured to deliver gas to the gas inlet of the deposition chamber. At least a portion of the gas system is positioned above the deposition chamber. The gas system includes a mixer configured to mix a plurality of gas streams. A transfer member is in fluid communication with the mixer and the gas inlet. The transfer member comprising a pair of horizontally divergent walls configured to spread the gas in a horizontal direction before entering the gas inlet.

FIELD OF INVENTION [0001] The present invention relates to master for creating a magnetic pattern on a magnetic media. BACKGROUND [0002] Magnetic disks and disk drives are conventionally employed for storing data in magnetizable form. Preferably, one or more disks are rotated on a central axis in combination with data transducing heads positioned in close proximity to the recording surfaces of the disks and moved generally radially with respect thereto. Magnetic disks are usually housed in a magnetic disk unit in a stationary state with a magnetic head having a specific load elastically in contact with and pressed against the surface of the disk. Data are written onto and read from a rapidly rotating recording disk by means of a magnetic head transducer assembly that flies closely over the surface of the disk. Preferably, each face of each disk will have its own independent head. [0003] Disc drives at their most basic level work on the same mechanical principles as media such as compact discs or even records, however, magnetic disc drives can write and read information much more quickly than compact discs (or records for that matter!). The specific data is placed on a rotating platter and information is then read or written via a head that moves across the platter as it spins. Records do this in an analog fashion where the disc's grooves pick up various vibrations that then translate to audio signals, and compact discs use a laser to pick up and write information optically. [0004] In a magnetic disc drive, however, digital information (expressed as combinations of “0's” and “1's”) is written on tiny magnetic bits (which themselves are made up of many even smaller grains). When a bit is written, a magnetic field produced by the disc drive's head orients the bit's magnetization in a particular direction, corresponding to either a 0 or 1. The magnetism in the head in essence “flips” the magnetization in the bit between two stable orientations. In currently produced hard disc drives, longitudinal recording is used. In longitudinal recording, the magnetization in the bits is flipped between lying parallel and anti-parallel to the direction in which the head is moving relative to the disc. [0005] Newer longitudinal recording methods could allow beyond 100 gigabits per square inch in density. A great challenge however is maintaining a strong signal-to-noise ratio for the bits recorded on the media. When the bit size is reduced, the signal-to-noise ratio is decreased, making the bits more difficult to detect, as well as more difficult to keep stable. [0006] Perpendicular recording could enable one to record bits at a higher density than longitudinal recording, because it can produce higher magnetic fields in the recording medium. In perpendicular recording, the magnetization of the disc, instead of lying in the disc's plane as it does in longitudinal recording, stands on end perpendicular to the plane of the disc. The bits are then represented as regions of upward or downward directed magnetization (corresponding to the 1's and 0's of the digital data). [0007] Increasing areal densities within disc drives is no small task. For the past few years, technologists have been increasing areal densities in longitudinal recording at a rate in excess of 100% per year. But it is becoming more challenging to increase areal densities, and this rate is expected to eventually slow until new magnetic recording methods are developed. [0008] To continue pushing areal densities in recording and increase overall storage capacity, the data bits must be made smaller and put closer together. However, there are limits to how small the bits may be made. If the bit becomes too small, the magnetic energy holding the bit in place may become so small that thermal energy may cause it to demagnetize over time. This phenomenon is known as superparamagnetism. To avoid superparamagnetic effects, disc media manufacturers have been increasing the coercivity (the “field” required to write a bit) of the disc. [0009] In magnetic disk, “servo sectors” are pre-written to define data tracks. Traditionally, servo-sectors were written by a tool called servo-track writer. There is also a method to write servo sectors by means of magnetic-contact printing, to which the RAIL invention is related to. In magnetic disk media, there is a sector called “servo-sector” where the disk manufacturer prints data for the operation of the disk using a master by an imaging process. The servo-sector typically occupies about 5-10% of the disk capacity. As the areal density increases it is also desirable to decrease the size of the servo-sector. This decrease in the size of the servo-sector could be brought about by increases in the imaging process, known as patterning, for making the master. [0010] Patterning is an operation that removes specific portions on the surface of the master. Photolithography is one of the terms used to identify the operation of patterning. Other terms used are photomasking, masking, microlithography and interference lithography. [0011] Patterning is one of the important operations in disk media manufacturing. The goal of the operation is twofold. First, is to create in and on the master surface a pattern whose dimensions are as close to as the resolution of the images on the master. The pattern dimensions are referred to as the feature sizes or image sizes of the pattern. The second goal is the correct placement (called alignment or registration) of the pattern on the master. The entire pattern must be correctly placed on the master and the individual parts of the pattern must be in the correct positions relative to each other. [0012] Lithography is a pattern transfer process similar to photography and stenciling. In the field of mastering the servo-patterned media (SPM), laser-beam and electron beam lithography are mature technologies. The system consists of an electron source that produces a small-diameter spot and a “blanker” capable of turning the beam on and off. The exposure must take place in a vacuum to prevent air molecules from interfering with the electron beam. The beam passes through electrostatic plates capable of directing (or steering) the beam in the x-y direction on the SPM. This system is functionally similar to the beam steering mechanisms of a television set. Precise direction of the beam requires that the beam travel in a vacuum chamber in which there is the electron beam source, support mechanisms, and the substrate being exposed. Since the pattern required generates from the computer, there is no mask. The beam is directed to specific positions on the surface by the deflection subsystem and the beam turned on where a photoresist (also called a resist) is to be exposed. Larger substrates are mounted on an x-y stage and are moved under the beam to achieve full surface exposure. This alignment and exposure technique is called direct writing. [0013] The pattern is exposed in the resist by either raster or vector scanning. Raster scanning is the movement of the electron beam side-to-side and down the wafer. The computer directs the movement and activates the blanker in the regions where the resist is to be exposed. One drawback to raster scanning is the time required for the beam to scan, since it must travel over the entire surface. In vector scanning, the beam is moved directly to the regions that have to be exposed. At each location, small square or rectangular shaped areas are exposed, building up the desired shape of the exposed area. [0014] However, with the x-y stage-based lithography tools, accurate r-θ position control was difficult which led to the development of the electron-beam recorder with a rotating stage and a linear controller, which provided with an accurate r-θ position control. The r-θ position controlled lithography also made it possible to define small features, determined mainly by the beam-spot size, which is important for making a master for SPM as the density increases. One requirement for the SPM master is an accurate trackpitch control. It is affected by factors such as vibration, random beam deflection due to disturbances, precision and stability of linear actuator control. Despite extensive engineering efforts, it is difficult to achieve trackpitch variation (3σ) less than 10 nm, which is required for the SPM master for hard disks at 200 kTPI (tracks per inch). The limitation is mainly due to inability to control the beam position relative to the wafer (substrate) accurately, affected by the factors mentioned above. Another disadvantage of the e-beam lithography is the slow throughput. [0015] On the other hand, there exists a technology called interferometric lithography. It can make fine periodic patterns, but it could not make patterns required for the SPM master, consisting of synchronous fields, position-error-signal (PES) bursts, and so on, in an arc shape representing head movement with a rotary actuator in a hard-disk drive. SUMMARY OF THE INVENTION [0016] This invention preferably relates to a rotary apertured interferometric lithography (RAIL) system that includes interferometric lithography tools, a mask with a slit, preferably with an arc shape, and a rotating stage. One embodiment is a rotary apertured interferometric lithography (RAIL) system comprising an interferometric tool, a rotating stage and a mask having an aperture that creates a servo pattern in a master for magnetic-contact printing. Preferably, the servo-pattern tracks a recording-head trajectory of a hard disk drive. Another embodiment of the RAIL system further comprises a phase shifter that controls a position of an interference fringe. Preferably, the aperture is an arc-shaped slit. Preferably, the RAIL system comprises a laser beam and the system forms a trackpitch determined by a wavelength of a laser of the laser beam and an incident angle of the laser beam. Preferably, the master has a feature having a size of less than 0.35 micron and a standard deviation of a period of less than 1 nm. [0017] Another embodiment is a master having a feature having a standard deviation of a period of less than 1 nm, the master being a master for magnetic-contact printing. Preferably, the master contains a servo-pattern that tracks a recording-head trajectory of a hard disk drive. Preferably, the feature has a size of less than 0.35 micron. [0018] Yet another embodiment is a method of manufacturing a master comprising applying a resist to a substrate, patterning the resist by interferometric lithography to form a patterned resist, and depositing a metal on the patterned resist, wherein the master has a feature having a standard deviation of a period of less than 1 nm and the master is a master for magnetic-contact printing. Preferably, the depositing a metal comprises sputtering depositing a metal layer and subsequently electroplating a metal film on the metal layer. Further preferably, the patterning the resist comprises exposing the resist to a laser beam and developing the resist. In one embodiment, the patterned resist contains depressions of different depths. [0019] Another embodiment is a method of forming a servo-sector in a magnetic disk medium comprising contacting a master having a feature having a standard deviation of less than 1 nm to the magnetic disk medium and exposing the master to a magnetic field. Preferably, the exposing the master to a magnetic field creates a magnetic pattern in a magnetic layer of the magnetic disk medium. [0020] Additional advantages of this invention will become readily apparent to those skilled in this art from the following detailed description, wherein only the preferred embodiments of this invention is shown and described, simply by way of illustration of the best mode contemplated for carrying out this invention. As will be realized, this invention is capable of other and different embodiments, and its details are capable of modifications in various obvious respects, all without departing from this invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive. BRIEF DESCRIPTION OF THE DRAWINGS [0021] FIG. 1 shows a side view of an embodiment of the RAIL system. [0022] FIG. 2 shows a top view of an embodiment of the RAIL system. [0023] FIG. 3 shows one embodiment of the resulting patterns formed on a photoresist by the RAIL system. [0024] FIG. 4 shows another embodiment of the resulting patterns formed on a photoresist by the RAIL system. DETAILED DESCRIPTION [0025] This invention differs from prior systems by allowing precise trackpitch determined by the wavelength of the laser used and the incident angle of two beams, with much better trackpitch variation than the prior systems. It can make patterns required for the master for Contact-print Servo Patterned Media (CSPM). [0026] The method of performing RAIL and calibrating MR head geometry in self-servo writing disc drives is described in the U.S. Pat. No. 6,317,285 incorporated herein by reference. [0027] For the master of CSPM, one preferred requirement is the trackpitch variation, and it is determined by the interference optics and not affected by the environmental disturbance significantly in the present invention. [0028] The present invention has an additional benefit of reducing the time required for recording a master, since it can be done in a single rotation of the rotating stage, as opposed to hundreds of thousands of rotations required in the prior arts using a LBR or EBR. [0029] Briefly, the RAIL process is the following. The required pattern is first formed in reticles or photomasks and transferred into the surface layer(s) of master through a photomasking steps. The transfer takes place in several steps. First, the pattern on the mask is transferred into a layer of a photoresist spread out on a smooth, solid surface such as that of a silicon wafer or a glass plate. Photoresist is a light-sensitive material similar to the coating on a regular photographic film. Exposure of light (or laser) causes changes in its structure and properties. In one type, for example the negative photoresist, the photoresist in the region exposed to the light is changed from a soluble material to an insoluble material. The soluble portions are removed with chemical solvents (developers) leaving a hole in the resist layer corresponding to the pattern on the mask. [0030] The second transfer takes places from the photoresist layer into the master surface layer as follows. The patterned photoresist layer is sputter coated with a layer of metal. Then a metal film such as a nickel film is electroplated on the sputter deposited metal layer. The metal film is peeled off and it has a topography pattern corresponding to the pattern on the mask. This metal film is used as the master. The master is laid on a magnetic disk and exposed to a magnetic field to create a magnetic pattern in the magnetic layer of the magnetic medium. [0031] The selection of a photoresist depends on several factors. The primary driving force is the dimensions required on the master surface. The resist must first have the capability of producing those dimensions. Beyond that it must also function as an etch barrier during the etching step, a function that requires a certain thickness for mechanical strength, it must be free of pinholes, which also requires a certain thickness. In the embodiment described above, an etch process is not necessarily required. However, the master has a certain thickness. In addition, it must adhere to the top wafer surface or the pattern will be distorted, just as a paint stencil will give a sloppy image if it is not taped tight to the surface. These, along with process latitude and step coverage capabilities, are resist performance factors. In the selection of a resist, one often must make trade-off decisions between the various performance factors. The photoresist is one part of a system of chemical processes and equipment that must work together to produce the image results and be productive, that is, an acceptable cost of ownership for the whole patterning process. [0032] Resolution capability: The smallest opening or space that can be produced in a photoresist layer is generally referred to as its resolution capability. The smaller the line produced, the better the resolution capability. Resolution capability for a particular resist is referenced to a particular process including the exposing source and developing process. Changing the other process parameters will alter the inherent resolution capability of the resist. Generally, smaller line openings are produced with a thinner resist film thickness. However, a resist layer must be thick enough to function as an and be pinhole-free. The selection of a resist thickness is a trade-off between these two goals. The capability of a particular resist relative to resolution and thickness is measured by its aspect ratio. The aspect ratio is calculated as the ratio of the resist thickness to the image opening. Positive resists have a higher aspect ratio compared to negative resists, which means that for a given image-size opening, the resist layer can be thicker. The ability of positive resist to resolve a smaller opening is due to the smaller size of the polymer. It is a little like the requirement of using a smaller brush to paint a thinner line. [0033] Adhesion capability: In its role as an etch barrier, a photoresist layer must adhere well to the surface layer to faithfully transfer the resist opening into the layer. Lack of adhesion results in distorted images. Resists differ in their ability to adhere to the various surfaces used in chip fabrication. Within the photomasking process, there are a number of steps that are specifically included to promote the natural adhesion of the resist to the wafer surface. Negative resists generally have a higher adhesion capability than positive resists. [0034] Photoresist exposure speed, sensitivity, and exposure source: The primary action of a photoresist is the change in structure in response to an exposing light or radiation. An important process factor is the speed at which that reaction takes place. The faster the speed, the faster the wafers can be processed through the masking area. Negative resists typically require 5 to 15 seconds of exposure time, while positive resists take three to four times longer. The sensitivity of a resist relates to the amount of energy required to cause the polymerization or photosolubilization to occur. Further, sensitivity relates to the energy associated with specific wavelength of the exposing source. Understanding this property requires a familiarization with the nature of the electromagnetic spectrum. Within nature we identify a number of different types of energy: light, short and long radio waves, x-rays, etc. In reality they are all electromagnetic energy (or radiation) and are differentiated from each other by their wavelengths, with the shorter wavelength radiation having higher energies. [0035] Common positive and negative photoresists respond to energies in the ultraviolet and deep ultraviolet (DUV) portion of the spectrum. Some are designed to respond to particular wavelength peaks within those ranges. Some resists are designed to work with x-rays or electron beams (e-beam). Resist sensitivity, as a parameter, is measured as the amount of energy required to initiate the basic reaction. The units are milijoules per square centimeter (mJ/cm 2 ). The specific wavelengths the resist reacts to are called the spectral response characteristic of the resist. The peaks in the spectrum are regions (wavelengths) that carry higher amounts of energy. [0036] Process latitude: While reading the sections on the individual masking process steps, the reader should keep in mind the fact that the goal of the overall process is a faithful reproduction of the required image size in the wafer layer(s). Every step has an influence on the final image size and each of the steps has inherent process variations. Some resists are more tolerant of these variations, that is, they have a wider process latitude. The wider the process latitude, the higher the probability that the images on the wafer will meet the required dimensional specifications. [0037] Pinholes: Pinholes are microscopically small voids in the resist layer. They are detrimental because they allow to seep through the resist layer and etch small holes in the surface layer. Pinholes come from particulate contamination in the environment, the spin process, and from structural voids in the resist layer. [0038] The thinner the resist layer, the more pinholes. Therefore, thicker films have fewer pinholes but they also make the resolution of small openings more difficult. These two factors present one of the classic trade-offs in determining a process resist thickness. One of the principal advantages of positive resists is their higher aspect ratio, which allows a thicker resist film and a lower pinhole count for a given image size. [0039] Particle and contamination levels: Resists, like other process chemicals must meet stringent standards for particle content, sodium and trace metal contaminants, and water content. [0040] Thermal flow: During the masking process there are two heating steps. The first, called soft bake, evaporates solvents from the resist. The second one, hard bake, takes place after the image has been developed in the resist layer. The purpose of the hard bake is to increase the adhesion of the resist to the wafer surface. However, the resist, being a plastic-like material, will soften and flow during the hard bake step. The amount of flow has an important effect on the final image size. The resist has to maintain its shape and structure during the bake or the process design must account for dimensional changes due to thermal flow. [0041] The goal of the process engineer is to achieve as high a bake temperature as possible to maximize adhesion. This temperature is limited by the flow characteristics of the resist. In general, the more stable the thermal flow of the resist, the better it is in the process. [0042] The performance factors outlined above are related to a number of physical and chemical properties of the resist. A photoresist is a liquid that is applied to the wafer by a spinning technique. The thickness of resist left on the wafer is a function of the spin step parameters and several resist properties: solids content and viscosity. [0043] The surface tension of a resist also influences the outcome at spin. Surface tension is a measure of the attractive forces in the surface of the liquid. Liquids with high surface tension flow less readily on a flat surface. It is the surface tension that draws a liquid into a spherical shape on a surface or in a tube. [0044] The optical properties of the resist play a role in the exposure mechanism. One property is refraction or the bending of light as it passes through a transparent or semitransparent medium. The index of refraction is a measurement of the speed of light in a material compared to its speed in air. It is calculated as the ratio of the reflecting angle to the impinging angle. Preferably for photoresists, the index of refraction is close to that of glass, approximately 1.45. [0045] Embodiments of this invention are shown in FIGS. 1 to 4 . FIGS. 1 and 2 show the side and top views of an embodiment of a RAIL system. In FIG. 1 , two laser beams interfere and expose a photoresist to form a pattern on the photoresist. A beam splitter splits a laser beam into two interfering beams. The RAIL system also preferably has a phase shifter that controls a position of an interference fringe. The photoresist is then chemically developed to create a resist pattern with different depths in the pattern. [0046] Interference lithography (IL) is the preferred method for fabricating periodic and quasi-periodic patterns that must be spatially coherent over large areas. IL is a conceptually simple process where two coherent beams interfere to produce a standing wave, which can be recorded in a photoresist. The spatial-period of the grating can be as fine as half the wavelength of the interfering light, allowing for structures on the order of 100 nm from UV wavelengths, and features as small as 30-40 nm using a deep UV ArF laser, for example. [0047] In particular, it is preferable to control the flexure of the substrate during exposure of the resist. For example, a controlled flexure of the substrate during exposure can reduce the distortion of the pattern from 2 dimensions to 1 dimension as well as reduce the magnitude of the distortions by about a factor of 5. [0048] For spatial periods of the order of 100 nm, one could use a 193 nm wavelength ArF laser. To compensate for the limited temporal coherence of the source, one could utilize an achromatic scheme in which the spatial period of the printed grating is dependent only on the period of the parent gratings used in the interferometer, regardless of the optical path or the wavelength and coherence of the source. Thus, gratings and grids produced with such a tool are extremely repeatable. A 100 nm-period grid can be produced using achromatic interferometric lithography (AIL) on a photoresist. The RAIL system could use AIL, which could be used to produce 50 nm period gratings and grids, or 25 nm lines and spaces using reflection gratings with a 58.4 nm helium discharge source. [0049] The basic principle is that features in crosstrack direction are defined by interference fringes created by two coherent laser beams. It will create a periodic pattern (lines and spacing), the period of which is determined by [0000] period = λ 2   sin   θ [0000] where λ is the wavelength of the laser and θ is an angle as shown in FIG. 1 . For example, with λ=257 nm and θ=80°, the period can be 130 nm, which is sufficient for 390 kTPI. The period is twice the trackpitch of the servo patterns as shown in FIG. 3 , wherein the period is measured from the leading edge of one track to the leading edge of another adjacent track. However, the period could also be measured from any other defined location on one track to another similarly defined location on an adjacent track. For example, the period could be measured from the trailing edge (or center) of one track to the trailing edge (or center) of another adjacent track. [0050] The features in downtrack direction are defined by a slit of the mask confining the exposed area of the beam spot, and the resolution is limited by the diffraction. The patterns as shown in FIGS. 3 and 4 can be made by the combination of the blanking of the laser beam and the incremental rotation of the wafer, for example. The downtrack length of the features is not necessarily as small as the crosstrack length, and can be on the order of μm, which is sufficient for the master for printed-pattern assisted self-servo write. [0051] Shifting the phase of one of the laser beams can make the checkerboard-like patterns as shown in FIG. 3 , such that the positions of the constructive and destructive interference change as desired. Only one beam with double intensity, for example, could also be used to make synchronous field patterns. For a printed-pattern assisted self-servo write master, it is not necessary to record gray code fields. Preferably, the shape of the slit can be an arc to mimic the head trajectory in a drive with a rotary actuator. [0052] The master has a substantially uniform period of the pattern with a standard deviation of the period being less than 1 nm, preferably less than 0.5 nm. Current e-beam method results in a standard deviation of the period of about 3-5 nm. The present invention uses an interference method to create the pattern, which will give a standard deviation of the period of less than 1 nm, preferably, less than 0.1 nm. Also, the pattern by the RAIL system has a feature size of less then 0.35 microns, preferably less than 0.3 microns, and more preferably less than 0.25 microns. Current photolithography methods result in a feature size of more than 0.35 microns. [0053] This application discloses several numerical ranges in the text and figures. The numerical ranges disclosed inherently support any range or value within the disclosed numerical ranges even though a precise range limitation is not stated verbatim in the specification because this invention can be practiced throughout the disclosed numerical ranges. [0054] The above description is presented to enable a person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, this invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. Finally, the entire disclosure of the patents and publications referred in this application are hereby incorporated herein by reference.

A rotary apertured interferometric lithography (RAIL) system that includes interferometric lithography tools, a mask with a slit preferably with an arc shape, and a rotating stage is disclosed. The RAIL system could create a servo pattern of a recording-head trajectory of a hard disk drive in a master for magnetic-contact printing. The master can could be used to form arrays of sub-micron sized magnetic elements on a magnetic disk media for high-density magnetic recording applications.

BACKGROUND OF THE INVENTION This invention relates to an improved process for preparing calcined gypsum and more particularly pertains to the formation of low consistency calcium sulfate hemihydrate produced by atmospheric calcination processes, particularly continuous kettle operations. Ordinarily calcined gypsum from good quality gypsum by atmospheric processes, known under various names, such as stucco, plaster of Paris, molding plaster, building plaster and the like, consists of the beta hemihydrate of calcium sulfate, CaSO 4 .1/2H 2 O. This material is capable of being reconverted into calcium sulfate dihydrate, CaSO 4 .2H 2 O, by mixing it with proper amounts of water. The theoretical water required to convert the stucco to gypsum dihydrate is only 18.7 parts by weight per 100 parts of pure hemihydrate CaSO 4 .1/2H 2 O. However, in order to produce a workable aqueous slurry in a modern automated gypsum board plant the stucco will be mixed with amounts of water in excess of that required for hydration. Thus the mixing water required may vary from about 85-100 parts of water per 100 parts of the calcined gypsum by weight. The excess, about 67 to about 82 parts of water, present in the slurry will be removed by drying the board. Ordinarily, gypsum board dryers in automated gypsum board manufacturing lines will remove this water, for example, by maintaining a drying air temperature at about 400° F. and requiring a drying time of about 40 minutes. Of course, the time-temperature relationship is variable from one processing plant to another primarily depending upon the particular gypsum source and processing equipment available. Continuously calcined gypsum stucco, prepared in a kettle or a rotary calciner for example, processed in the usual manner comprises stucco particles with innumerable fissures and imperfections resulting from the violent dehydration process occuring under the harsh conditions of atmospheric calcination. These particles when added to the water and agitated, as during the slurry mixing process step, break up into smaller fragments thus exposing large surface areas of calcium sulfate, and therefore requiring a high amount of mixing water to obtain a fluid slurry. The additional water forms voids upon evaporation and thus greatly impairs the strength of products formed from this stucco. It has become the custom in the gypsum industry to describe the amount of water, expressed in cubic centimeters or grams required to be added to 100 grams of calcined gypsum to produce a slurry with a standard fluidity such as the amount in a given time to flow through a standardized container as the "consistency" of that plaster. This is usually expressed by merely a number, it being understood, however, that the number means cubic centimeters or grams of water per 100 grams of that stucco. In addition, it has further become the custom in the gypsum industry to delineate particular consistencies for particular mixing conditions such as a "7 second consistency" wherein the stucco is dispersed by mechanical mixing in a laboratory mixer at a high sheer intensity and for a standard time of 7 seconds. For many years various additives have been admixed with ordinary calcined gypsum for the purpose of producing a lower consistency than that which is characteristic of the particular calcined gypsum. Such materials may be exemplified by various ligno sulfonates and synthesized non-lignin based high molecular weight sulfonates as being a class of stucco dispersants having particular efficacy. These chemicals are considered chemical consistency reducers and apparently they act to reduce the interaction between the stucco fragments in aqueous suspension thus requiring less water to make a slurry of standard fluidity. Such segmented stuccos ordinarily have a consistency of around 68-79 cc. DESCRIPTION OF THE PRIOR ART In U.S. Pat. Nos. 4,117,070 and 4,153,373, there are described various apparatus and processes for continuously treating calcined gypsum so as to lower the water demand and provide a treated calcined gypsum mass which may be continuously fed into the slurry mixer of an automated gypsum board line. The treatments comprise thoroughly blending small amounts of water into the dry stucco, resulting in a damp but dry appearing material; and allowing it to "heal" before usage in gypsum board manufacture. By "healing" is meant allowing the small amounts of free water to remain on the particle's surface for about 1-10 minutes or more during which time large fissures on the particle may fuse so as to resist subsequent disintegration into micron sized factions upon mixing the treated material with water for hydration to gypsum dihydrate. In U.S. patent application by Eugene O'Neill under Ser. No. 939,624 now U.S. Pat. No. 4,201,595 there is disclosed a process which is an improvement over said patents by grinding the water treated material, generally up to about 4 times, in order to recapture physical properties lost during the water treatment. Copending U.S. Ser. Nos. 939,624 and 054,069 relating to improvements in U.S. Pat. No. 4,117,070 recite that following the rapid water treatment and healing of the calcined gypsum, the water treated calcined gypsum may be combined with conventional additives such as "fluidizing agents" for use in making gypsum wallboard or bagged plaster products. Thus, U.S. Ser. No. 939,624 recites that the common chemical dispersing or fluidizing agents for calcined gypsum such as the lignins, ligno sulfates, ligno sulfonates and condensation polymerization products thereof may be included with the treated stucco in minor amounts to enable the use of even less mixing water in addition to the water reducing effects accomplished by the prior rapid water treatment steps. U.S. Pat. No. 3,770,468 discloses treating freshly burnt plaster of Paris containing considerable quantities, e.g. 50% of anhydrite III (an unstable, very soluble form which almost instantly converts back to much more stable hemihydrate) with aqueous solutions of retarders and/or wetting agents to stabilize that plaster. Such burnt plaster may be encountered in European flash calcination processes but is uncharacteristic to atmospheric continuous kettle or even continuous rotary calcining operations. It is uncommon for these latter operations to produce plasters containing more than a few percent of such anhydrite at which levels the ordinary cooling in moisture laden air usually accomplishes almost complete instantaneous conversion to the hemihydrate. SUMMARY OF THE INVENTION This invention relates to an improvement in processes for preparing calcined gypsum (stucco) by rapidly water treating continuously calcined gypsum to a healed calcium sulfate hemihydrate having the property of lowered water demand, which improvement provides increased effectiveness of rapid water treatment to the damp but dry appearing stucco and, quite surprisely, easier flowability of the damp but dry appearing treated stucco and easier grindability of the treated stucco. The process involves treating the stucco with a dilute aqueous solution of a sulfonate instead of with plain water for the rapid water treatment. Laboratory scale and full-sized plant trials indicate thereby that easier flowability and grindability of the treated stucco as a powder and in aqueous slurry results without impairing the ability of the treated calcined gypsum to produce acceptable properties in products such as gypsum board, industrial plasters and building plasters. Further, this change in addition sequence appears to require less excess water. At present it is not known whether these result from a more effective coating of the stucco particles with the water during the water treatment or whether they result from the more efficient water treatment, i.e., fusing of more and/or smaller fissures and or fractures to a greater depth in the conglomerate's surface. But in any case, merely changing the order of addition on the use of the same amounts of the same materials resulted in less surface area irregularity and improved rheological properties in the so treated stucco. Thus, principal objects and advantages of the present invention are the provisions of an improved process for treating calcined gypsum so as to lower the water demand of the stucco while maintaining the material's ability to produce acceptable physical and rheological properties in such products as gypsum board, building plasters and industrial plasters. In one preferred embodiment of the present invention, it was found the above objects and advantages and others were accomplished by the steps by forming a dilute aqueous solution of one or more sulfonated lignin salts or polymerized salts of sulfonic acid similar to the natural lignin materials; blending a small amount of the solution thoroughly with stucco so as to admix around 20-200 lbs. (preferably 40-60 lbs.) of water from the solution per ton (2,000 lbs.) of stucco and on a dry weight solids basis around 1/2-5 lbs. (preferably 1-3 lbs.) of sulfonate from the solution per ton (2,000 lbs.) of stucco; allowing the solution treated stucco to heal for about 1-10 minutes or more (preferably 3-30 minutes); optionally drying the healed stucco; optionally grinding the healed stucco to increase strength properties of the treated stucco; and for the manufacture of gypsum board therefrom the additional steps of mixing the healed stucco with additional water, the additional water being in an amount to provide from about 50 to about 85 parts of water including water adding in the sulfonate solution per 100 parts of the healed stucco; mixing the water and healed stucco to form a homogeneous slurry; feeding the slurry to a gypsum board making machine to form a wet gypsum board, passing the wet gypsum board to a drier to dry the wet board, and recovering dry gypsum board. BRIEF DESCRIPTION OF THE DRAWINGS The FIGURE presents a graphic representation of the correlation in specific surface areas of particles treated by the present invention to power consumed in treating the particles. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS It has been found in the present invention that solution treatment with a small but effective amount of a ligno sulfonate or synthesized high molecular weight sulfonic acid derivative equivalent to the natural lignin, for the rapid water treatment instead of using plain water provides a lubricity or lack of attraction forces between the treated particles so that the treated stucco moves more easily, e.g., requires less energy in mixing and conveying the treated material for further processing. The process also results in making the treated stucco easier to meter accurately in the further processing of the stucco so as to overcome problems in surging, sticking and like related handling problems in board formation. The sulfonates usable in the present invention comprise a wide range of readily available commercial gypsum dispersing agents that may be referred to as water soluble salts of sulfonic acid. Typically, they are anionic wetting agents that are sulfonated lignins or high molecular weight polymerized salts of sulfonic acid. In general they are either by-products of the paper and pulp industry or polymerized salts of sulfonic acid similar to the natural lignin raw material derived agents. Table A lists a number of commercially available ligno sulfonates or polymerized synthetic sulfonates similar thereto which may be utilized in the practice of the present invention. TABLE A______________________________________TradeName Manufacturer Composition______________________________________Orzan Crown Zellerback Corp. Ammonium ligno sulfonateOrzan Crown Zellerback Corp. Sodium ligno sulfonateSL (liquid)Sodalig International Paper Co. Sodium ligno sulfonate (liquid)Reax Westvaco Chemical Div. Sodium salt of sulfonated88-B modified kraft ligninLignosol Reed Chemical Co. Sodium ligno sulfonateXD (spray dried)Lignosol Reed Chemical Co. Ammonium ligno sulfonateTSD (spray dried)Lignosol Reed Chemical Co. Sodium ligno sulfonateSFX (desugarized, spray dried)Daxad 19 W.R. Grace & Co. Sodium alkyl naphthalene sulfonic acid salt highly polymerizedMara- American Can Co. Sodium ligno sulfonatesperse (sulphite paper process41-g-3 lignin)Norlig American Can Co. Ammonium ligon sulfonateA (sulphite lignin)Norlig American Can Co. Calcium ligno sulfonate412 (sulphite lignin)Norlig American Can Co. Calcium ligno sulfonate415 (modified sulphite paper process lignin)Lomar Diamond Shamrock Potassium alkyl naphtha-HP lene sulfonic acid salt highly polymerized (spray dried)______________________________________ In general, any sulfonate selected from the class consisting of alkali metal ligno sulfonates, alkaline earth metal ligno sulfonates, ammonium ligno sulfonates and corresponding synthesized high molecular weight polymerized water soluble salts of sulfonic acid may be used in the present invention. In addition manganese, chromium, iron and/or zinc salts may be used in the present invention. Generally, the ligno sulfonates and synthesized sulfonates described hereinabove will be available in aqueous solution or in powder form very readily dissolvable in the water for the normal rapid water treatment of the stucco. Thus, in general the dry stucco will be thoroughly blended with water in amounts of from about 1-10%, and more preferably 2% to 4% by weight of dry stucco. In forming a dilute solution of the sulfonate for use in the present invention, the forms of sulfonate available as solids will be dissolved in the rapid water treatment water and those forms available as liquids will be diluted in the water to be used in the rapid water treatment step. The amount of sulfonates to be added to the treatment water will generally be about 1/25 lbs., or preferably 1-3 lbs. by weight on a solids basis of sulfonate per ton of the dry stucco to be treated. Of course, it is also possible to admix the dry stucco to be treated with the sulfonate and then rapidly water treat this mixture. But in any event, rapid water treating the dry stucco with a solution of the sulfonate results in treated particles of stucco that have improved rheological and powder flow behavior characteristics. Any method to provide small, limited amounts of the sulfonate and free water on the surface of the stucco may be employed. Thus, the materials may be combined in any order of addition in any of a number of apparatus for the purpose; however it is preferred at present to spray a solution of the sulfonate onto a rapidly moving and tumbling mass of stucco for thorough blending. The solution treated stucco is allowed to briefly heal, generally for about 1-10 minutes or more, and more preferably around 2-15 minutes, immediately after solution treatment and before further processing. Of course, the duration of the healing depends upon the particular manner of the solution addition and the amounts of solution being added. That is, the addition of greater amounts of water in the range herein will generally require less healing time, which for a solution adding about 3% by weight of water and 1% by weight of sulfonate will be on the order of about 3 minutes. The stucco feed material for the present invention may be any beta hemihydrate product of conventional batch or continuous calcination from any gypsum source, such gypsum sources being for example high quality natural rock or gypsum derived from chemical processes, including blends of natural rock gypsum and chemical process gypsum. If the solution treated and healed material is not to be used immediately in production, as when bagged industrial or building plasters are to be made with the addition of further ingredients before the bagging operation, it is preferable to thoroughly dry the material before it is stored for any prolonged period of time. If the solution treated and healed stucco is to be used immediately, as in the production of gypsum board, then it is usually not necessary to dry the material. However, some drying may be desired, particularly if more than the optimum water has been added during the solution treatment or in the event of a shut down in the continuous board making line since drying will enable the healed material to be stored without excessive localized hydration and subsequent impairment of the physical and chemical characteristics. Any drying temperature and time conditions should be selected so as not to remove the chemically combined water in the solution treated and healed stucco. Further, optionally, the solution treated and healed stucco may be ground to increase the surface area of the treated material generally from about 2.5 to 4 times or more the surface area of the untreated stucco. Depending upon the particular starting stucco, the method of water incorporation and the proposed usage for the material, grinding of the solution treated and healed stucco may or may not be desirable. Generally, for the manufacture of gypsum board from a high purity natural gypsum rock source in a continuous operation, such will not be desirable, and immediate passage of the treated stucco to the processing line, e.g., the slurry mixer of a continuous board forming machine, is appropriate. The following examples will illustrate various specific embodiments of the process of the present invention. Of course, it is to be understood that the following examples are by way of illustration only and in no way are to be construed as limitations on the present invention. For example, the hereinafter specific examples in most cases utilized neat stucco, e.g., pure continuously calcined beta hemihydrate without additives conventional to normal processing to various industrial bagged plasters, bagged building plasters or additives in conjunction with gypsum board formation. EXAMPLE 1 In a series of comparative evaluations, continuously calcined beta hemihydrate stuccos produced at different times were treated in laboratory bench scale tests to either incorporate about 3% by weight of free moisture and/or 1 lb. of sulfonate per ton of stucco. In the evaluations, set forth in Table B, the "Rapid Water Treatment" (RWT) stuccos were treated by thoroughly blending 3% by weight based on the weight of the dry stucco of water into the beta hemihydrate calcium sulfate, allowing the water treated stucco to heal for approximately 1-15 minutes, and then drying the healed material at a temperature of 110° F. in an air circulating oven for 12 hours. For the other evaluations, the procedure remained the same except that the indicated amount of a sulfonate was either added to the gauging water (mixing water for hydration of the calcium sulfate hemihydrate to a set gypsum dihydrate) or incorporated into the RWT water. From Table B it can be clearly seen in this instance with these particular stuccos and sulfonates that merely changing the order of addition so that the material was treated with a solution of the same sulfonate resulted in much lower normal consistencies than if the stucco was treated with plain water and the sulfonate added in the gauging water or if no sulfonate was added at all. TABLE B______________________________________ 7 Second Dispersed ConsistencyTreatment Sulfonate 1 Sulfonate 2______________________________________Rapid Water Treatment(RWT) with 3% plain water 72 cc. 77 cc.(RWT) with 3% plain waterplus 1 lb./ton sulfonateadded to gauging water 70 73(RWT) with 3% plain waterplus 1 lb./ton sulfonate 68 70added to RWT water______________________________________ Sulfonate 1 = Norlig 412 sulfonate Sulfonate 2 = Reax 88B sulfonate. During the treatments described in Table B, visual examination of the solution treated rapid water treatment (RWT) stuccos indicated that the moist but dry appearing stuccos in both cases were less lumpy in appearance than the RWT stuccos treated with plain water; thus indicating less agglomeration and sticking between the individual particles and therefore greater ease of handling, conveying and metering the solution treated material with a minimum surging of the material flow rates in continuous board making or bagging operations. EXAMPLE 2 In a full-sized plant trial for the production of gypsum board, a plant operating line was modified to insert in the stucco feed conveying line, between the continuous calcination equipment and the board slurry mixer, a rapid water treatment mixer of the continuous paddle mixer type to add about 1-4% of water to the dry stuccos. The calcination and gypsum board lines were operated for a brief period of time so as to produce 5/8 inch gypsum board at a rate of 50 ft. per minute with 2% by weight plain water treatment of the stucco, on a dry weight basis, and 2 lb. per ton of Raylig sulfonate being added to the gauging water for the gypsum board slurry mixer. Then the water for the RWT was modified to contain from 0.5 to 1 lb. per ton of stucco, on a dry solids basis, of Reax 88B sulfonate and the board making operation visually observed for effectiveness of using a sulfonate solution for the RWT water. It was visually observed that flow rate and handleability of the RWT treated material with sulfonate solution was at least as good if not better including meterability of the treated material to the board mixer and general handling and conveyability of the treated material during processing. Chemically and physically satisfactory board was produced. EXAMPLE 3 The process of the present invention was applied in another series of evaluations to Southard Oklahoma stucco using different sulfonates and different amounts of sulfonate addition as set forth under Example 1. In the first series of this evaluation, 4 different sulfonates were added at the rate of 2 lbs., solids weight basis, of the sulfonate per ton of dry stucco and one of the sulfonates was also added at 1 lb. and 4 lbs. per ton rates, with results as set forth in Table C. TABLE C______________________________________ Seconds Max. Rate of Dispersed Tem. Temp. RiseTreatment Consistency Rise Set during Set______________________________________Stucco with 2%water treatment 74 18 minutes 5° F./minuteStucco with 2%water treatmentwith sulfonate solu-tions: -2 lb/ton LomarHP sulfonate 71.sup.a (69).sup.b 16 (18) 5 (4.3)2 lb/ton Daxad 19sulfonate 69 (68) 17 171/2) 4.5 (4.0)2 lb/ton Lignosol SFXsulfonate 72 (71) 171/2 (19) 4.8 (4.3)2 lb/ton Norlig 415sulfonate 70 (70) 233/4 (193/4) 3.5 (3.9)1 lb/ton Norlig 415sulfonate 73 (73) 213/4 (191/2) 3.2 (4.1)4 lb/ton Norlig 415sulfonate 69 (69) 21 (211/2) 3.6 (3.6)______________________________________ .sup.a Solution added in RWT water. .sup.b Solution added in gauging water. TABLE D______________________________________ Power Con- Surface sumption in Area B.E.T. CTreatment RWT Mixer cm.sup.2 /gm Intercepts value______________________________________Untreated -- 68,000 0.005885 120 C% Plain Water 970 watts 30,610 .00893 159 C% Norlig 415sulfonate solution 821 watts 28,110 .0104 104 C% Lomar HPsulfonate solution 746 watts 26,290 .0149 110 C______________________________________ As can be seen from Table C for some inexplicable reason within this portion of evaluations addition of like amounts of sulfonates to the gauging water appeared in two instances to give slightly better results but in most cases consistency, maximum rate of temperature rise during set and set times (which are additional measures of stucco activity during hydration) were better on addition of the sulfonate to the rapid water treatment water. In a second series of the evaluations of this example accurate specific surface areas for certain of the samples were determined by a standard nitrogen adsorption method, generally known as the B.E.T. surface area determination method which is quite accurate for particles with cracks, fissures and/or pores and much more complete for such particles, than the Blaine surface area measurements. In addition, the power consumption of the mixing device used for the rapid water treatment of the continuously calcined stucco for the samples was also determined by power readings on the mixer. The results of the specific surface areas and power consumptions are set forth in Table D. The results set forth in Table D are shown diagrammatically in the FIGURE. From the FIGURE it is apparent that with treatment according to the present invention using increasingly more efficient sulfonates at the same level that the energy required to move the wet mass decreased directly as the surface area of the treated particle decreased. The decreased surface areas (by about 1/5th or so of the plain water treated particle's surface area) are due to the increased healing of fissures and fractures in the particles surface as a result of the present invention.

A process for preparing calcined gypsum (stucco) which comprises treating a mass of calcined gypsum by adding, with thorough blending, small portions of an aqueous solution of ligno sulfonate; allowing the treated stucco to heal; and optionally drying the healed stucco and further optionally grinding the healed stucco. If the treated calcined gypsum is not to be used shortly after the healing procedure, it should be dried to provide storage stability. If further strength is desired the treated stucco should be ground to expose fresh crystal faces. The process is particularly useful in gypsum board manufacture and production of bagged building and industrial plasters.

CROSS-REFERENCE TO RELATED U.S. APPLICATIONS [0001] Not applicable. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not applicable. NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT [0003] Not applicable. REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC [0004] Not applicable. BACKGROUND OF THE INVENTION [0005] 1. Field of the Invention [0006] The present invention relates, in general, to a cage for construction work with an extendable function and, more particularly, to a cage for construction work with an extendable function, which is formed so as to have both extendibility and safety by allowing for lateral extension of a cage used in finish work for the outer wall of a structure when constructing the structure, and integrally forming a guard net for preventing falls from an upper part thereof. [0007] 2. Description of Related Art [0008] Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98. [0009] Recently, it is a general trend that, in regions such as cities in which the density of the structures is high and the land is also expensive, the demand for increasing the number of floors of the structure is sharply increasing so that the land can be effectively used. [0010] As such, as the number of floors of the structures increases, there is a risk that various construction materials, working tools, dust, etc. can fall down from the interior of the structure to the outside thereof during the construction work. Accordingly, in order to prevent human damage, property damage and environmental pollution due to such a sudden falling or dropping trouble, various type of safety guard nets are already used in the art. [0011] In using such a safety guard net for construction work, a method for binding a tent or a dust proof net to the outer side of the framework of the structure or installing a frame on the outer side and then fixing a dust proof net to the frame, etc. is mainly adapted. [0012] Furthermore, as is well known in the art, in construction methods for large scale structures such as apartments, buildings or hospitals, low regions (first to third floors) are firstly constructed using a normal mould. A cage for the mould is mounted on the structures using a tower crane, and then concrete is poured to construct the large scale structure while moving the cage upward. [0013] Then, in order to improve the urban view by variously modifying the outer wall of the structures and to receive effectively natural lighting, only the frame and slab works which erect the framework of the structures are done using concrete, and the other parts of the structures are separately constructed using exterior finishing material such glass for the finishing work. [0014] As an example of the finishing work of the structures mentioned above, a structure construction method (Korea Patent No. 895614) invented by the present applicant is disclosed. This structure construction method includes a construction method (SWC; Safety Working Cage) in which a process for constructing the framework of the structure by pouring concrete and a process for finishing the outer wall of the structure are simultaneously performed at intervals of two floors or three floors. Equipment capable of protecting workers doing finishing work on the lower floors is required by the above construction method. [0015] Further, the cage used for finishing work can be obtained by modifying the cage for pouring concrete. Therefore, there is a problem that the working space is limited and thus not enough working space can be secured for the worker doing the finishing work to work smoothly. [0016] Further, since there is no safety facility to provide adequate protection against falling things and dust generated from the concrete pouring work in the upper side, the worker working on the lower floors is likely to be damaged by the falling things. [0017] Recently, various types of structures incorporating a special design have been constructed. For this reason, when constructing the building having the special design at irregular intervals of several floors, a cage for finishing work which can rapidly respond to special design needs is strongly required. [0018] The present invention is developed in consideration of the problems associated with the related art. An object of the present invention is to provide a cage for construction work with an extendable function, which can rapidly respond to the special design of the structure and, in particular, can rapidly respond to the grooves or protrusions on the outer wall of the structures. [0019] Further, another object of the present invention is to provide a cage for construction work with an extendable function, which is capable of improving the work environment, allowing the finishing work to be safer and preventing the worker or the workers' tools from falling down, by making a walking plate to be extendable in the cage used for the finishing work such as on a curtain wall of the structures. [0020] In addition, yet another object of the present invention is to provide a cage for construction work with an extendable function, which is capable of preventing the worker or the workers' tools from falling down a short distance and that can minimize human damage and property damage, by integrally forming a vertical guard net on the upper part of a cage for finish work. [0021] Further, another object of the present invention is to provide a cage for construction work with an extendable function, which is capable of maximizing the work efficiency by responding suitably to the special design of the structures and being able to undergo self-modification. Also, the cage can reduce the number of cages and material cost by making the cage extendible in a lateral direction, and save on costs related to safety facilities in the work field. BRIEF SUMMARY OF THE INVENTION [0022] In order to achieve the above objects, according to one aspect of the present invention, there is provided a cage for construction work with an extendible function. The cage includes a frame formed by connecting a vertical bar and a horizontal bar to each other and integrally formed at an upper side thereof with a frame for vertical guard net, a walk plate provided on the upper surface of the horizontal bar, a guard net assembled to the upper and lower surfaces of the frame for the vertical guard net, and an extending frame formed at the lower part of the frame. The extending frame is assembled to the frame so as to move in lateral direction by a slide means. [0023] According to another aspect of the present invention, an auxiliary walk plate rotating through a hinge and a wire regulating the rotational radius of the auxiliary walk plate are further provided on one side of the extending frame. Thus, the auxiliary walk plate has an extendable function. [0024] According to yet another aspect of the present invention, the slide means includes a fixing body and a guide rail. The fixing body is assembled to the vertical bar through a bolt insertion hole and includes a rolling wheel at the inner surface thereof. The guide rail surrounds the outer surface of the rolling wheel in a “C” shape and is assembled to a position corresponding to the fixing body outside of the extending frame. [0025] According to another aspect of the present invention, a set of three fixing bodies are assembled to the outer surface of a pair of corresponding horizontal bars. [0026] According to yet another aspect of the present invention, the slide means includes an H-shaped guide rail assembled to the lower surface of the horizontal bar and a moving body assembled to the upper surface of the extending frame. The upper wheel of the moving body is slidably assembled to the guide rail while making close contact therewith. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0027] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: [0028] FIG. 1 is a perspective view illustrating a cage for construction work with an extendable function, according to the present invention; [0029] FIG. 2 is a perspective view illustrating an extending frame of a cage for construction work with an extendable function, according to the present invention; [0030] FIG. 3 is a partial magnified perspective view illustrating the frame part of a cage for construction work with an extendable function, according to the present invention; [0031] FIG. 4 is a magnified view illustrating the “A” portion shown in FIG. 1 ; [0032] FIG. 5 is a magnified side view illustrating a slide means of a cage for construction work with an extendable function, according to the present invention; [0033] FIG. 6 is a side view illustrating another example of the slide means in a cage for construction work with an extendable function, according to the present invention; and [0034] FIG. 7 is a front view illustrating an application example of the cage for construction work with an extendable function, according to the present invention. DETAILED DESCRIPTION OF THE INVENTION [0035] Hereinafter, preferred embodiments of the present invention will be described in details with reference to the accompanying drawings. The embodiments of the present invention can be changed in various forms and thus the present invention is not limited to the embodiments disclosed hereinafter. [0036] FIG. 1 is a perspective view illustrating a cage for construction work with an extendable function, according to the present invention. [0037] As shown in FIG. 1 , a cage 100 (hereinafter, referred to as “cage”) for construction work with an extendable function, according to the present invention, mainly includes a frame 10 , an extending frame 20 and a slide means 30 . A vertical protection frame 11 is integrally formed with the upper part of the frame 10 . The extending frame 20 is movably assembled to the lower part of the frame 10 . The slide means 30 can stably move the extending frame away from the frame 10 in lateral direction. [0038] The frame 10 has a box form of a rectangular parallelepiped shape formed by connecting a vertical bar 12 , a horizontal bar 13 and a connecting bar 14 to each other, and a walk plate 15 is assembled to the upper surface of the connecting bar 14 , so that workers can easily perform work. [0039] That is, one box-shaped frame 10 is formed by connecting the vertical bar 12 and the horizontal bar 12 to form a flat plate and connecting a pair of the flat plates to each other by the connecting bar 14 . [0040] Also, the upper part of the frame 10 is integrally formed with a frame 11 for vertical guard net bent toward the outside of the structure. A guard net 16 is assembled to the frame 11 and the uppermost horizontal bar 13 of the frame 10 , so that a safety facility to prevent dropped things from falling is formed. [0041] Further, an extending frame 20 capable of moving in lateral direction by the slide means 30 is formed at the lower part of the frame 10 . [0042] As shown in FIG. 2 , in the extending frame 20 , a horizontal bar 21 , a vertical bar 22 and a connecting bar 23 are connected to each other so as to form a box form. A walk plate 24 is formed at the bottom surface of the extending frame. And, one or more guide rail 25 on outer side and an auxiliary walk plate on one side are rotatably assembled to each other by a hinge 28 . [0043] That is, the extending frame 20 in one box form is formed, by connecting the horizontal bar 21 and the vertical bar 22 to obtain two plates and then connecting two plates to each other by the connecting bar 23 , as in the frame 10 . [0044] In addition, the rotation range of the auxiliary walk plate 26 is regulated by a wire 27 connected to the extending frame 20 . [0045] Next, the process for sliding the extending frame 20 away from the frame 10 will be explained in detail, by referring to FIGS. 3 and 4 . [0046] As shown in FIGS. 3 and 4 , the slide means 30 is constituted by slidably connecting the rolling wheels 32 of several fixing bodies 31 formed at the lower part of the frame 10 and a guide rail 25 assembled to the outside of the extending frame 20 . [0047] That is, several fixing bodies 31 are integrally bolted to the lower part of the vertical bar 12 of the frame 10 . Preferably, two fixing bodies are connected to the upper side thereof and one fixing body is connected to the lower side thereof. By doing so, two fixing bodies in the upper side can allow the extending frame 20 to move smoothly in the lateral direction and the one fixing body in the lower side can prevent the extending frame from being shaken, when the extending frame is moved. [0048] Further, by providing the fixing body 31 only on one place in the lower side, it is possible to prevent the worker's legs from being interfered with by the rail when the auxiliary walk plate 26 is extended. The fixing body 31 is assembled to the vertical bar 12 of the frame 10 having the box form as mentioned above, and then the extending frame 20 is slidably fitted and assembled to the fixing body from one side thereof. This becomes possible by inserting the rolling wheel 32 of the fixing body 31 into the guide rail 25 formed at the outer peripheral surface of the extending frame 20 for allowing the sliding movement the extending frame 20 . [0049] In addition, several bolt inserting holes 33 are formed at the back surface of the fixing body 31 so as to surround or penetrate the vertical bar 12 and to assemble firmly the fixing body 31 . [0050] On the other hand, it is preferred that the guide rail 24 is formed at one side thereof with a separation prevention means (not shown) such as a fixing pin or engaging jaw capable of controlling the lateral movement in order not to be separated from the frame following excessive movement. [0051] FIG. 6 is a side view illustrating another example of the slide means in a cage for construction work with an extendable function, according to the present invention. [0052] As shown in figures, a guide rail 41 in a form of “H” is assembled to the lower surface of the horizontal bar 14 , and the rolling wheel 42 a of the moving body 42 assembled to the upper surface of the extending frame 20 is closely assembled to the outer peripheral surface of the guide rail 41 . [0053] The slide means 40 as mentioned above can prevent the front and rear parts of the extending frame 20 from being clogged and thus provide a better work environment. [0054] FIG. 7 is a front view illustrating an application example of the cage for construction work with an extendable function, according to the present invention. As is apparent from FIG. 7 , the finish work for the space between adjacent cages can be performed with no difficulty, by connecting the extending frame into a space between two cages. [0055] That is, according to the above embodiment, it is possible to respond rapidly to the special designs of the structures such as protrusions, when the structures are constructed. Accordingly, various types of the structures can be smoothly constructed and additional costs stemming from changing the form of the structures is not generated. [0056] Further, it is possible to save the installation cost by reducing the number of the cages used when the structures are constructed. And it is also possible to save costs and strengthen the safety facility by assigning the function of a safety guard net to the cage for finish work. [0057] As apparent from the above description, the cage for construction work according to the present invention provides advantages in that, it is possible to provide a guard net at the safest height and at a location capable of preventing the danger of falls by forming the vertical guard net integrally with the upper part of the cage for finish work, so that the falling of the worker or the workers' tools can be prevented. In particular, it is possible to prevent the worker from falling down and thus to minimize the human harm. [0058] Further, the cage for construction work according to the present invention provides advantages in that, since the cage includes the extending frame formed at the lower part of the cage and the auxiliary walk plate spread auxiliary for increasing the rotating radius thereof, workers can safely perform the finish work in a state of a maximum amount of work space being secured. [0059] In addition, the cage for construction work according to the present invention provides advantages in that, since the cage includes the extending frame, the spaces between adjacent cages, can be easily shortened and lengthened by protruding parts of the structure. Accordingly, the work efficiency can be maximized, the number of the cages can be reduced and construction work for the structures having special design needs can be safely performed. [0060] Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

A cage for construction work is provided with an extendable function. More particularly, a cage for construction work with an extendable function is provided which is formed so as to have both extendibility and safety by allowing for lateral extension of a cage used in finish work for the outer wall of a structure when constructing the structure and integrally forming a guard net for preventing falls on an upper part thereof.

TECHNICAL FIELD OF THE INVENTION This invention relates to reciprocating compressors for transporting natural gas or other gases, and more particularly to a method for reducing pulsations in the compressor system associated with such compressors. BACKGROUND OF THE INVENTION To transport natural gas from production sites to consumers, pipeline operators install large compressors at transport stations along the pipelines. Natural gas pipeline networks connect production operations with local distribution companies through thousands of miles of gas transmission lines. Typically, reciprocating gas compressors are used as the prime mover for pipeline transport operations because of the relatively high pressure ratio required. Reciprocating gas compressors may also be used to compress gas for storage applications or in processing plant applications prior to transport. Reciprocating gas compressors are a type of compressor that compresses gas using a piston in a cylinder connected to a crankshaft. The crankshaft may be driven by a motor or an engine. A suction valve in the compressor cylinder receives input gas, which is then compressed by the piston and discharged through a discharge valve. Reciprocating gas compressors inherently generate transient pulsating flows because of the piston motion and alternating valve motion. Various devices and control methods have been developed to control these pulsations. An ideal pulsation control design reduces system pulsations to acceptable levels without compromising compressor performance. A specific challenge when using high-horsepower, high-speed, variable-speed compressors is pulsations in the cylinder nozzle. The cylinder nozzle is the section of pipe that connects the cylinder to the suction or discharge side of the compressor, typically to a filter bottle. This section of pipe can provide significant resonance responses. Currently, one solution to attenuating cylinder nozzle pulsations is the installation of an orifice in the cylinder nozzle. For example, a plate with a flow restricting hole may be placed across the circumference of the nozzle. However, a drawback to use of the orifice is that it causes a pressure drop that requires the supply of additional horsepower. This burden can be significant on large horsepower units. BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein: FIG. 1 is a block diagram of a reciprocating gas compressor system. FIG. 2 illustrates a multi-chamber pulsation absorber installed at a cylinder valve cap in accordance with the invention. FIG. 3 is a perspective view of the multi-chamber pulsation absorber. FIG. 4 is a cut-away view of the multi-chamber pulsation absorber. FIG. 5 illustrates the cutaway view of the absorber of FIG. 4 , with the absorber installed in place of a valve cap, as in FIG. 2 , so that it communicates with gas internal to the cylinder. DETAILED DESCRIPTION OF THE INVENTION The following description is directed to a multi-chamber pulsation absorber for reducing pulsations of a compressor system. The absorber, mounted at a cylinder valve cap and having properly designed acoustic dimensions, is capable of altering the acoustically resonant frequencies of the cylinder internals as well as of the cylinder nozzle. The absorber eliminates the need for a nozzle orifice and reduces the cylinder internal pulsations such that associated vibrations, valve life problems, and/or efficiency problems associated with those pulsations are nearly eliminated. As stated in the Background, pulsation absorbers may be attached to the cylinder nozzle. However, these absorbers address only the cylinder nozzle response frequency. Other resonances associated with the cylinder internal gas passages are not addressed with the single volume and choke. FIG. 1 is a block diagram of the basic elements of a reciprocating gas compressor system 100 . The elements of compressor system 100 are depicted as those of a typical or “generic” system, and include a driver 11 , compressor 12 , suction filter bottle 18 a , discharge filter bottle 18 b , suction and discharge piping connections, and a controller 17 . In the example of FIG. 1 , compressor 12 has three compressor cylinders 12 a - 12 c . In practice, compressor 12 may have fewer or more (often as many as six) cylinders. Further, it may have either an integral or separate engine or motor driver 11 . The output of driver 11 (motor or engine) may be variable speed and power, unloaded through the compressor. The driver 11 is often an internal combustion engine. The following description is written in terms of the “generic” compressor system 100 . However, the same concepts are applicable to other compressor configurations. A typical application of compressor system 100 is in the gas transmission industry. The compressor station operates between two gas transmission lines. The first line, at an initial pressure, is referred to as the suction line. The second line, at the exit pressure for the station, is referred to as the discharge line. The suction and discharge lines are also referred to in the industry as the “lateral piping”. The pressure ratio (discharge pressure divided by suction pressure) may vary between 1.15 to 4.0 or more, depending on the pipeline operation requirements and the application. Filter bottles 18 a and 18 b are placed between the compressor and the lateral piping, on the suction or discharge side or on both sides. Filter bottles such as these are installed as a common method for pulsation control. They operate with surge volumes, and are commonly implemented as volume-choke-volume devices. They function as low-pass acoustic filters, and attenuate pulsations on the basis of a predetermined Helmholtz response. Controller 17 is used for control of parameters affecting compressor load and capacity. The pipeline operation will vary based on the flow rate demands and pressure variations. The compressor must be capable of changing its flow capacity and load according to the pipeline operation. Controller 17 is equipped with processing and memory devices, appropriate input and output devices, and an appropriate user interface. It is programmed to perform the various control tasks and deliver control parameters to the compressor system. Given appropriate input data, output specifications, and control objectives, algorithms for programming controller 17 may be developed and executed. FIG. 2 illustrates a nozzle pulsation absorber 30 installed at a cylinder valve cap 32 in accordance with the invention. Although only one cylinder 31 and one absorber 30 are shown, additional absorbers 30 may be installed on more than one cylinder, and they may be installed on the suction side and/or the discharge side of the cylinder(s). The cylinder nozzle 35 is a section of pipe that connects the cylinder 31 to the discharge or suction side of the compressor. Compressor valves (not explicitly visible in FIG. 2 ) are installed on each cylinder 31 to permit one-way flow into or out of the cylinder volume. In the example of FIG. 2 , cylinder 31 is illustrated as having two suction valves and two discharge valves, with valve caps 32 on three valves and an absorber 30 at one of the discharge valves. As explained below, nozzle pulsation absorber 30 is a multi-chamber side branch absorber, having multiple choke tubes and volumes. In accordance with the invention, absorber 30 can be designed to dampen multiple pulsation frequencies, including (but not limited to) the cylinder internal (valve-to-valve) response, the response of the cylinder nozzle, and the cylinder internal cross-mode. FIG. 3 is a perspective view of the absorber 30 . Its housing 39 provides the outer shell for two or more internal chambers, as explained below in connection with FIG. 4 . The housing is typically cylindrical in shape, but other geometries are possible. The longitudinal axis of housing 39 extends vertically from the compressor valve opening. A flange 37 is a large ring at one end of housing 39 , and facilitates attachment of the absorber 30 to the valve cap opening. The absorber may be integrated with the cylinder valve cap, so that the valve cap and absorber are a single assembly. In some cases it may be necessary to attach the absorber to a modified valve cap. Therefore, the absorber is installed in place of or attached to a valve cap. The attachment of the absorber on the compressor cylinder is a sealed attachment, with the cylinder's internal gas passage open only to the absorber's internal choke tubes. A bottom plate 38 has three openings, each corresponding to an open end of an internal choke tube (see FIG. 4 ). These openings are in communication with gases expelled from or inducted into the associated compressor cylinder, via the valve port. FIG. 4 is a cut-away view of the absorber 30 . In the example of FIG. 4 , absorber has three chambers 41 a , 42 a , and 43 a , and three internal choke tubes 41 b , 42 b , and 43 b . As illustrated, two partitions within the housing 39 divide the internal volume of the housing into the three chambers. The partitions are horizontal, such that the chambers are “stacked” vertically along the vertical axis of the housing 39 . The choke tubes are small sections of piping with two open ends. A choke tube is associated with (paired with) each chamber (volume), and each choke tube has a first end open to the compressor cylinder valve port and a second end open to the associated chamber. Each choke tube and chamber pairing is designed to dampen a different resonant frequency of the compressor system. In other embodiments, absorber 30 may have only two, or more than three, choke tubes and chamber pairings. As is known in the art of side branch absorbers (also known as Helmholtz resonators) for other applications, the physical dimensions of each choke tube and its associated surge volume are not the same as their acoustic dimensions. The desired acoustic dimensions and the resulting physical dimensions are determined by various known calculation and acoustic modeling techniques. The internal volume of the chamber and the length and diameter of the choke tube are variables that can be used to “tune” the resonance of each choke tube and chamber pairing. The acoustic dimensions of each choke tube and chamber pairing vary depending on the pulsation frequency to be dampened by that pairing. The resonant frequency to be damped may be determined by various measurement or predictive techniques. More specifically, the diameter and size of each choke tube and the size of its associated chamber determine an acoustic natural frequency. Each choke tube and chamber pairing is designed to dampen a different resonant frequency of the compressor system. At least one pairing is specifically designed to dampen cylinder internal (valve-to-valve) pulsations. Another is specifically designed to dampen nozzle pulsations. Additional choke tube and chamber pairings may be designed to dampen other internal cylinder pulsations. In operation, two or more target frequencies to be damped are identified. Each choke tube and chamber pairing of the absorber is designed so that its acoustic response frequency matches that of the target frequency. Calculations for Helmholtz resonators may be used, and are well documented. Compressor system models may be used for further refinement of the absorber response. The absorber is then installed in place of or attached to the valve cap, such that each chamber, via its associated choke tube, is in fluid communication with the cylinder gas passage. FIG. 5 illustrates the cutaway view of the absorber of FIG. 4 , with the absorber installed in place of a valve cap, as in FIG. 2 , so that it communicates with gas internal to the cylinder. As stated above, the absorber is installed such that each chamber, via its associated choke tube, is in fluid communication with the valve's internal gas passage. In other words, the openings at the bottom ends of the choke tubes are in communication with gases expelled from or inducted into the cylinder.

A multi-chambered pulsation absorber for attachment over the valve cap opening of a compressor cylinder. Each chamber is in fluid communication with the valve cap opening (or cylinder internal gas passages) via an associated choke tube. Each pairing of a chamber with a choke tube is tuned, in the manner of a Helmholz resonator, to attenuate and nearly eliminate a different cylinder-related pulsation frequency, such as those resulting from internal cylinder pulsations or cylinder nozzle pulsations.

FIELD OF THE INVENTION [0001] The present invention relates to a pyrolytic method and apparatus for upgrading residual hydrocarbons, and asphaltenic hydrocarbons in particular. BACKGROUND [0002] Upgrading of heavy oil refers to any process of fractionation or treatment of bitumen to increase its value. About one-half of bitumen can be recovered by atmospheric and vacuum distillations, leaving heavy residual hydrocarbons with contaminants. These residual hydrocarbons and other heavy hydrocarbons from various sources can be cracked to give smaller molecules which are more valuable products. [0003] Conventional upgrading technologies include catalytic cracking and thermal cracking or pyrolysis. Catalytic cracking of residual hydrocarbons, particularly asphaltenic hydrocarbons, is difficult as large molecular weight hydrocarbons have low diffusivity into catalyst pores and channels. As well, residual hydrocarbons are rich in coke precursors and catalyst poisons, which severely restrict effective utilization of catalysts. As a result, catalytic methods are less common, and pyrolytic methods are more commonplace in residue upgrading. [0004] Thermal cracking is the oldest and, in a way, the simplest cracking process. It basically aims at the reduction of molecular size by application of heat without any additional sophistication such as catalyst or hydrogen. At temperature levels exceeding about 370° C., the larger hydrocarbon molecules become unstable and tend to break into smaller molecules. By varying the reaction time, temperature and pressure under which a particular feedstock remains under cracking conditions, the desired degree of cracking (conversion) can be controlled. [0005] Coking is a widely-implemented form of thermal cracking, where light products are formed together with significant amounts of coke. Coking, like all pyrolytic methods, is an endothermic process and it is well known that the rate of reaction increases rapidly with increased temperature. However, because coke formation and fouling of heat transfer surfaces also increase rapidly with temperature, viable operating temperatures are conventionally limited to a lower range. Therefore, reaction rates and effectiveness of conventional pyrolytic methods, such as thermal cracking and coking processes are limited. [0006] Additionally, the rate of heating affects coke production. If a feedstock is gradually heated to a pyrolytic temperature, coke formation is significantly higher than if the feedstock is rapidly brought to the same temperature. In U.S. Pat. No. 3,481,720 issued to Bennett on Dec. 2, 1969, a method of pyrolysis of oil shale or oil sands in a concentric reactor-combustor unit is disclosed. Hot “spent” oil shale or oil sands is combined with cold feed oil shale or oil sands to recover heat energy and preheat the feedstock. With oil shale or oil sands, a significant amount of energy is required to heat the shale or sands to reaction temperatures; therefore, heat exchange between the hot “spent” shale or sands with the cold feedstock is essential for energy economy. However, such gradual heating of the feedstock drastically increases coke formation and fouling when processing residual hydrocarbon feedstock, and would be impractical for asphaltenes or residues with high asphaltene contents. [0007] Therefore, there is a need in the art for a process that can achieve fast and selective pyrolysis of heavy hydrocarbons, with high yields of valuable light oils and gases, while significantly reducing coke formation and fouling that constrain conventional pyrolysis. SUMMARY OF THE INVENTION [0008] The present invention provides a process of pyrolysis of heavy hydrocarbons that provides relatively fast and selective upgrading into light oils and gases. The process may operate at higher temperatures than conventional pyrolytic processes, without significant adverse coke formation and fouling. The process of this invention operates at temperatures typically about 100° to 300° C. higher than conventional coking processes, preferably in the range of 500° to 800° C., and more preferably greater than 650° C., in the front end of the reactor. As a result, in one preferred embodiment, the intrinsic reaction rates of the present invention may be about 2 orders of magnitude higher than conventional pyrolysis processes, with lower coke make and sustainable operation without severe fouling. [0009] Therefore, in one embodiment, the invention comprises a method of pyrolytic upgrading of hydrocarbons, comprising the steps of: (a) flash cracking a hydrocarbon feedstock in a reaction zone with particulate solids heated to a temperature at least about 500° C., producing vapour products and coke, with typically a coke:CCR ratio of about 1.0 or less; (b) removing vapour products from the reaction zone; (c) transporting the solids from the reaction zone to a combustion zone where the solids are heated by combustion of accumulated coke; (d) transporting heated solids from the combustion zone to the reaction zone; (e) recovering the vapour products. [0015] In another aspect, the invention comprises an apparatus for pyrolysis of heavy hydrocarbons comprising: (a) a reaction chamber having a feed inlet and a vapour outlet; (b) a combustion chamber; (c) a thermal mass comprising particulate solids disposed within the reaction chamber and the combustion chamber; (d) transfer means for transporting heated solids from the combustion chamber to the reaction chamber and recycling solids from the reaction chamber back to the combustion chamber; (e) vapour recovery means connected to the vapour outlet. [0021] In one embodiment, the reaction chamber and combustion chamber are horizontally disposed in a single cylindrical vessel. BRIEF DESCRIPTION OF THE DRAWINGS [0022] The invention will now be described by way of an exemplary embodiment with reference to the accompanying simplified, diagrammatic, not-to-scale drawings where [0023] FIG. 1 is a schematic representation of a reactor/combustor vessel of the present invention and [0024] FIG. 2 is a schematic representation of a quench tower of the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0025] One embodiment of the invention will now be described, with reference to the schematic process flow schemes shown in FIG. 1 and FIG. 2 . In the following description, undefined terms have the meaning commonly recognized by those skilled in the art. The process and apparatus described herein are used to upgrade hydrocarbons, and heavy hydrocarbons in particular, including residual hydrocarbons and asphaltenes. The feedstock for the present invention may comprise any hydrocarbon which forms valuable products if upgraded or cracked. [0026] As shown in FIG. 1 , the primary process unit or vessel ( 10 ) comprises a reaction chamber or reactor ( 12 ) and a combustion chamber or combustor ( 14 ). In principle, it is possible to use separate reaction and combustion vessels, or one vessel with reaction and combustion zones and the present invention includes all such alternatives within its scope. In a preferred embodiment, the invention comprises a single vessel with separate and horizontally disposed reaction ( 12 ) and combustion ( 14 ) chambers. [0027] A secondary process unit or quench tower ( 20 ) may be used to quench the produced hot vapour products, as shown in FIG. 2 . The hot vapour may be quenched with incoming liquid feed (F), which also serves to flash the feed before it enters the reactor ( 12 ). [0028] The reactor ( 12 ) and the combustor ( 14 ) each comprise a bed of heated solid particles (S). In one embodiment, as the vessel rotates, internal lifters (not shown) attached to the vessel wall in both the reactor ( 12 ) and the combustor ( 14 ) lift the solid particles from the beds and subsequently dump back the particles as the lifters rise above the beds. As will be described below, flow of solids from the reactor ( 12 ) to the combustor ( 14 ) and back to the reactor ( 12 ) is a feature of the present invention. In one embodiment, the two chambers are substantially horizontally disposed and cylindrical. The vessel ( 10 ) is rotatable to effect solid flow from one chamber to the other using helical transfer coils ( 16 , 18 ). In an alternative embodiment, the chambers can be stacked vertically with solid flow achieved by mechanical means, or a combination of mechanical means and gravitation flow. The chambers may also be contained in separate vessels, and solid flow achieved by mechanical means. [0029] The feed (F) may comprise hydrocarbons in either liquid or solid form. In either case, the feed is fed into the reactor ( 12 ) to directly contact the solid particles (S) by either an injection sprayer ( 6 ), or a solids transfer device ( 8 ), or both. [0030] When processing liquid hydrocarbons, the feed is sprayed into the reactor bed in the front end. Preferably, the feed spray should avoid the hot reactor wall. The liquid droplets should be small enough to improve even distribution over the hot solids, but not atomized to avoid entrainment by the vapour product produced within the reactor. In one embodiment, feed temperature should be maintained below 400° C., preferably below 300° C. for asphaltenic residue, until the feedstock exits the feed injection sprayer(s). [0031] The liquid feedstock can be routed directly to the reactor ( 12 ), or it can be first fed to the quench tower ( 20 ), where it is flashed by contact with hot vapour products. The flashed heavy bottoms ( 24 ) can then be routed to the reactor ( 12 ) via stream ( 26 ), with an optional particulate clean up process ( 28 ), where solid contaminants may be removed using conventional or novel methods. [0032] When solid asphaltene particles are used as feedstock, the feedstock can be transported pneumatically, for example by using recycled light hydrocarbon gas products, or mechanically. Preferably, the temperature of the particulate asphaltene feedstock is maintained below its softening point, which is feedstock dependent. Accordingly, in one preferred embodiment, the asphaltene feedstock is maintained below about 100° C. until it exits the transfer device ( 8 ). Most solid asphaltene feedstock will not soften significantly below 100° C. If the asphaltene feed melts, it forms an extremely viscous liquid, which may lead to very rapid coking. An asphaltene feedstock will melt if it is gradually heated to reaction temperature. [0033] In one preferred embodiment, the asphaltene feed comprises porous asphaltene aggregates with occluded moisture, which shatter on entry to the hot reaction zone, forming fine particles leading to fast reactions and lower formation of coke. [0034] The bed (S) of hot solid particles is used to provide the heat necessary to drive the endothermic cracking in the reaction zone. Solid bed levels are maintained to effect sufficient hot solid circulation for heat supply from the combustion zone ( 14 ) to the reaction zone ( 12 ) to sustain the cracking reactions, while maintaining a vapour headspace within the reactor. In one embodiment, the hot solid particles are transferred by means of a helical coil or coils ( 16 ), as shown schematically in FIG. 1 . As is apparent, when the vessel is rotated about its longitudinal axis, material within the coil will be transported from the outlet end ( 32 ) of the combustor in the combustion chamber to the inlet end ( 34 ) in the reactor ( 12 ). At the same time, transfer line ( 18 ) coils in the direction to transport materials from the reactor ( 12 ) to the combustor ( 14 ). In this manner, solids heated in the combustion chamber are transferred to the reaction chamber, and are returned to the combustion chamber, driven by rotation of the vessel ( 10 ). [0035] Additionally, it is possible to transfer hot solids from the outlet end of the combustor ( 14 ) to the inlet end of the combustor ( 14 ) by means of a separate coil or coils (not shown), to raise the temperature at the combustor inlet end, if necessary or desired. [0036] In one embodiment, solids enter outlet ( 32 ) at the end of the combustion chamber ( 14 ) near the flue gas exit, and enters the reaction chamber ( 12 ) at inlet ( 34 ) disposed close to the feedstock inlet. Solids leave the reaction chamber ( 12 ) through outlet ( 36 ) disposed at the opposite end of the reaction chamber to inlet ( 34 ), and enters the combustion chamber ( 14 ), at the end ( 38 ) opposite the outlet ( 32 ). Although one set of coils ( 16 , 18 ) is illustrated in FIG. 1 , a plurality of coils may be used, which may increase operational smoothness. [0037] On exit from the transfer device ( 8 ) in the case of solids, or upon injection into the reaction chamber ( 12 ) in the case of liquids, the feed comes into direct contact with the very hot solids, rises rapidly in temperature and cracks thermally. It is desirable that the solid temperature is high enough to ensure very fast vaporization of the heaviest desirable products. [0038] Therefore, the hot solids may be in the range of 500° to 800° C. upon entry into the reaction chamber. Preferably, the hot solids are above about 650° C., at the entry of the reactor chamber. Fast vaporization of primary cracked products reduces close contact of reactive intermediates, thereby reducing coke formation by condensation reactions of such reactive intermediates. This fast cracking and vaporization is referred to herein as “flash cracking”. [0039] Upon vaporization, the products in gas phase in the reactor ( 12 ) are no longer in close contact with the hot solids. This, together with the much lower gas phase residence time (τ G ), vs solid residence time (τ s ), result in lower secondary cracking and hence lower gas make and high liquid yield. The unconverted heavy hydrocarbons stay with and continue to be heated by the hot solids (S), which continues to drive endothermic pyrolysis, and continue to thermally crack with a residence time (τs) much higher than (τG). [0040] Within the reactor ( 12 ), the hot solids (S) move away from the feed inlet end towards the vapour outlet end. The solid movement, in the reactor ( 12 ) or combustor ( 14 ), can be effected by controlling the angle of repose of the solid bed, and enhanced if desired by inclining the reaction-combustion vessel ( 10 ), or by internal means to positively move the bed forward towards the outlet end, such as by auguring plates or angled lifters (not shown). [0041] With flash cracking conditions described above, with gas residence time lower than solid residence time, coke make may be lower than conventional coking. For conventional delayed coker processes, coke/CCR (Conradson Carbon Residue) ratio is usually 1.2 to 1.8. With implementation of the present invention, coke/CCR ratio may be significantly lower, less than about 1.0, and may be in the range of about 0.5 to 0.8. Therefore, it is a feature of the present invention that the coke/CCR ratio does not exceed about 1.0 and is preferably below about 0.8. [0042] Any coke that is formed is predominantly deposited on the hot solids forming the thermal mass. The coked solids exit the reaction zone ( 36 ) and transported via the helical coil ( 18 ) or other means to the combustion zone ( 38 ), where the coke is combusted to generate energy required for the process. Feedstock and vapour products which contact the vessel wall may result in coke deposits on the walls. One feature of the present invention is a self-cleaning mechanism. Coke deposited on the reactor wall is continuously scoured by the solids within the vessel as the vessel rotates. [0043] The hydrocarbon vapour stream ( 40 ), comprising the cracked products, exits the reaction zone through a pipe ( 42 ), which is preferably routed through the combustion zone ( 14 ). As a result, the central pipe ( 42 ) walls could be very hot and coking might occur on the internal surfaces of the pipe ( 42 ). To minimize vapour coking on very hot pipe wall, it is preferable to provide an insulating gap between the pipe ( 42 ) and the combustion zone ( 14 ). An insulating gap may be formed by wrapping the pipe ( 42 ) in a concentric pipe jacket ( 44 ), forming an annular space there between. In one embodiment, steam may be injected through the annular gap. The steam enters from line ( 46 ), exits the outer pipe, and enters the reaction zone at ( 41 ), mixes with vapour products in the reactor and then enters the inner pipe ( 42 ) together with the hot vapour products. The steam insulates the pipe ( 42 ) from very high temperatures in the combustion zone. As it enters the vapour pipe ( 42 ), the steam accelerates gas velocity within the vapour pipe ( 42 ), reducing coking/fouling inside the pipe ( 42 ). [0044] Additionally, in a preferred embodiment, the steam becomes super-heated on its way through the outer jacket and promotes steam cracking of the vapour products in the reaction zone and in the exit pipe ( 42 ). [0045] In an alternative embodiment, the insulation can be achieved by flowing combustion air through the concentric pipe jacket ( 44 ) instead of steam, and directing the combustion air into the combustor ( 14 ). In this embodiment, the concentric pipe jacket does not open into the reactor ( 12 ); instead, the air is directed into the inlet end of the combustor ( 14 ). Steam may be injected by alternate means ( 46 A) into the reactor, if desired or necessary. [0046] In one embodiment, a counter-current operating mode implemented, where the vaporized products exit at the feed inlet end of the reactor, assisted if desired by steam injection. This mode of operation may provide higher liquid yield, but with higher liquid density. [0047] The thermal mass comprising hot solid particles (S) serves to provide a large surface area for rapid heat transfer to the feedstock. Additionally, the thermal mass serves as a heat carrier to deliver heat from the combustion zone to the reaction zone, and directly to the feedstock by contact. In a preferred embodiment, the circulating hot solids comprise limestone particles. In addition to serving as a heat carrier, the limestone will continuously scour coke from the hot wall surfaces without damaging wall surfaces. The limestone is calcined in the combustion zone forming CaO, which assists in removing sour gases. Limestone makeup, with or without lime addition for enhanced sour gas removal, can be injected into the combustion zone ( 47 ) or reaction zone ( 48 ). The limestone particles may be less than about 10 cm in size, and preferably less than about 1 cm. The smaller the particle size, the greater the surface area presented to the feedstock. However, if the particle size is too small, the particles may become entrained in the gas phase of the reactor and carried out with the flue gas. [0048] Inorganic fines and some coke fines can be carried out by the flue gas and removed by cyclones or other suitable means. Inorganics are also deposited on the hot solid carrier, and the level can be controlled by spent solid removal ( 50 ) with solids makeup ( 47 , 48 ) at a controlled rate. [0049] The coked solids entering the combustor ( 14 ) at inlet ( 38 ) may be burnt in the presence of air ( 52 ), which is preferably preheated. In one embodiment, the air is directed through the concentric pipe jacket ( 44 ) to the front end of the combustor ( 14 ). Coke burning is well known to those skilled in the art. The coke combustion rate is a function of temperature, oxygen concentration and coke surface area exposed to oxygen. The extent of combustion depends on exposure time of coked surfaces to oxygen. [0050] In a solid bed, only the bed surface exposed to air is active in combustion. Fluidized coke bed with upward air flow is commonly used in combustion, which is rather restrictive in particle size control. In one embodiment of this invention, enhancement of exposure of the coked surfaces to air is achieved by mechanically lifting the hot solids from the solid bed by lifters, and dumping the hot solids in a controlled fashion as the lifters move out of the bed and rise upwards. The solid surface areas of the particles in flight and the flight or exposure times can be precisely calculated and controlled, leading to controllable combustion rate. Depending on coke make, complete or partial oxidation can be desirable. With partial combustion, the flue gas ( 54 ) can be routed to a CO-boiler or furnace (not shown). [0051] For mechanical design purposes, the reaction and combustion zones are practically at atmospheric pressure. It may be preferable to maintain the reaction zone pressure at slightly below external pressure to avoid hydrocarbon vapour leakage, as a safety consideration. TABLE 1 Illustrative Yields of Asphaltene conversion Asphaltenes produced Natural from Alberta Asphaltenes Oil Sands Feedstock from US Midwest Bitumen Form fine powder aggregates C 5 asphaltene  70+% w  80+% w YIELDS C 1 -C 3 13.6% w 12.6% w C 4 + oil 78.1% v 77.3% v (36.6 API) Coke 23.8% w 29.6% w [0052] Having described specific embodiments of the invention, it will be apparent to those skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the scope of the invention claimed herein.

A process and apparatus for upgrading heavy hydrocarbons such as asphaltenes to lighter oil and gas components is disclosed. The process provides a reaction environment that promotes fast and selective cracking of heavy hydrocarbons, while minimizing coke formation and fouling and enhancing product yields.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention pertains broadly to a device for collecting soil samples, and more particularly to such a device which is mechanized and mounted upon a vehicle for enabling a single operator to rapidly and accurately collect a series of individual test samples and place the collected samples in receptacles for subsequent analysis. 2. Description of the Prior Art In the field of agricultural production, farmers are constantly challenged in an ever changing economy to seek ways to increase efficiency and profitability of production. One routine commonly employed to that end is the carrying out of a soil testing program to determine the proper rates of application of fertilizers and herbicides. In order to achieve more accurate fertilizer application, and thus better utilization, it is highly desirable to assess the soil fertility throughout a field. This requires intensive soil sampling, for example on a field grid basis, involving collection of many soil samples for separate laboratory analysis. As will be readily apparent the success of such a program depends upon the proper and inexpensive collection of soil samples. The samples must consistently represent the true soil conditions of an area to be treated. For example, the samples must represent the true available nutrient status of an area to be fertilized, or other appropriate parameters for areas to be treated with herbicides, insecticides and the like. The majority of technological advances in this field has been in the development of nutrient and herbicide application equipment, and the technique of soil sampling has not kept pace. Many suppliers currently using computer-controlled fertilizer and herbicide applicators still collect soil samples by means of a hand operated hollow tube probe, with no depth indication. Consequently, the soil sampling is highly subjective and operator dependent. The benefits of sophisticated computer-controlled fertilizer and herbicide application cannot be fully utilized unless the precision and accuracy of soil sampling is improved. As heretofore indicated soil sampling has in the past, and still largely is, done by manually inserting a hollow tube probe into the ground a certain distance, and then withdrawing the probe containing collected soil. The collected soil is then removed from the probe for subsequent analysis. As can be readily appreciated, this is a laborious and time consuming task not conducive to intensive soil sampling. Furthermore, due to resistance to penetration under certain soil conditions and obstructions such as rocks beneath the surface, the samples tend to be taken at different depths so as to produce inconsistent test results. Various types of mechanical soil samplers have been proposed, a number of them incorporating hollow tube probes into mechanism supplying weight and power for causing the probe to penetrate hard soils. Examples of such devices are disclosed in U.S. Pat. Nos. 3,464,504, 4,284,150, 4,333,541, 4,685,339, and 4,828,047. Other mechanical samplers employ a rotatably driven auger shaft which bores into the soil and withdraws a sample into a receptacle. Such devices are disclosed, for example in U.S. Pat. Nos. 3,593,809, 4,482,021, 4,534,231 and 5,076,372. These devices are of substantial size and complexity and are generally designed-to be operatively mounted upon a large vehicle such as a tractor or a heavy duty pickup truck. While the devices may eliminate the back breaking work of manual probing, each involves either the time consuming step of the operator frequently dismounting the vehicle for sample collection, or the services of two workers, one operating the vehicle and the other operating the soil collection device, to achieve greater speed in sample collecting. The rate of sample collection and efficient use of labor were apparently not of particular significance in the design of the devices. In addition, the prior art vehicle-mounted samplers are limited to use under weather and soil conditions which permit operation of the carrier vehicle, that is, the tractor or pickup truck in the field. The prior art devices thus do not entirely satisfy the requirements of present day agricultural practices for a soil sampling device which will make possible accurate and rapid collection of soil samples efficiently and inexpensively. SUMMARY OF THE INVENTION In accordance with the present invention there is provided a mechanized soil sampler which is easy to use, capable of rapidly collecting samples, labor efficient, relatively inexpensive, and allows for use under a wide variety of field conditions. The soil sampling unit is mounted upon a suitable mobile unit, preferably a four wheel all-terrain vehicle (ATV) or the like, whereby an operator can operate the sampling unit from the seat of the mobile unit without dismounting. The sampling unit includes a sampler arm pivotably affixed at one end to a base mounted upon the mobile unit. At its remote end the sampler arm pivotably carries a soil auger and soil accumulator container. An actuator is coupled to the sampler arm for swinging the arm between a lowered soil collecting position and a retracted accumulator container discharge position. A power unit is provided for rotating the soil auger, and the auger is adapted to be extended through the bottom of the accumulator container and into the earth as the container engages the ground surface upon lowering of the sampler arm. As the auger rotates the soil sample is drawn upwardly into the accumulator container by the auger flights. Spring loaded depth control spacers operate in conjunction with the accumulator container to limit the depth to which the auger penetrates the soil to a predetermined distance. With the sampler arm in the retracted position the soil accumulator container is positioned over a funnel device mounted on and positioned above the base. The floor of the accumulator container comprises a hinged trap door which is readily manipulatable by the seated operator for discharging the collected soil sample into the funnel. A suitable receptacle such as a box or bag is positioned beneath the funnel for receiving one or more of the collected soil samples from the accumulator container. A holder may be provided on the base for storing empty receptacles awaiting use and receptacles containing collected samples. A separate power unit may be mounted upon the mobile unit for operating the sampler arm and the soil auger. Alternatively, the sampler arm and auger unit may suitably be powered by the engine of the mobile unit. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, wherein like numerals refer to like part throughout: FIG. 1 is a side elevational view of a soil sampling device in accordance with the invention, mounted upon an all terrain vehicle or ATV; FIG. 2 is a top plan view of the device of FIG. 1; FIG. 3 is an enlarged fragmentary side elevational view of the drilling unit of the invention, with parts broken away; FIG. 4 is a sectional view taken substantially along line 4--4 of FIG. 3; FIG. 5 is a sectional view taken substantially along line 5-5 of FIG. 3; and FIG. 6 is a sectional view taken substantially along line 6--6 of FIG. 3. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and particularly to FIG. 1, there is shown generally at 10 a mobile soil sampling unit embodying the invention. More particularly, the mobile unit comprises a soil sampling unit 12 operably mounted as upon a conventional four wheel all-terrain vehicle or ATV, identified generally at 14. A power unit 16 is provided on the vehicle for operating the sampling unit 12. An ATV-type vehicle is ideally suited as the mobile platform for the sampling unit due to its maneuverability, light weight, relatively low cost and ability to operate under difficult field conditions. However, it is fully contemplated that the sampling unit may as well be adapted for mounting upon and use with other and different mobile units such as a pickup truck or tractor, or it may be mounted upon a trailer to be towed behind other vehicles. The all terrain vehicle 14 may be of a conventional type widely commercially available and the details of which do not form part of the invention. Such vehicles include a chassis shown generally at 18 mounted upon pairs of forward and rear wheels 20 and 22, respectively, which are adapted for carrying the vehicle over terrain under a wide variety of adverse field conditions. The rear wheels 22 are driven by a suitable power unit (not shown) and the forward wheels 20 are mounted so as to enable an operator (not shown) riding on a seat 24 to steer the vehicle as by handle bars 26. Clutch and brake pedals 28 and 30 and a gear shift lever 32 are conventionally provided for operating the vehicle. The soil sampling unit 12 is mounted on the chassis 18 at the forward end of the vehicle 14 so as to be readily operable and clearly visible by an operator from the seat 24. The operator is thus able to maneuver the vehicle into position for collecting a soil sample, and to then collect the sample and deposit it in a collection receptacle while remaining seated. To that end the sampling unit 12 comprises a base plate 34 for mounting as upon a framework 36 carried by the chassis 18 of the vehicle 14. A sampling arm 38 is attached at one end by means of a pivot pin 40 to a mounting bracket 42 affixed to the base plate, for pivotal swinging movement in a vertical plane. At its remote end the sampling arm carries a soil boring and collecting unit, identified generally at 44. The arm 38 is adapted to be swung between the lowered, soil-collecting and the raised, soil-discharge positions as illustrated in broken lines and as indicated by the arrows in FIG. 1. By way of example, the sampling arm may be adapted to swing through an arc on the order of 105°. To that end a suitably controlled linear actuator such as a conventional double acting hydraulic cylinder 46 is coupled to the sampling arm. The cylinder is pivotably connected at one end to a bracket 48 affixed to the base plate 34, and includes an extensible piston rod conventionally coupled by a pivot pin 52 to a bracket 54 affixed to the arm 38. Thus, by suitably manipulating the cylinder 46 as will be described, the piston rod can be extended and retracted to swing the arm 38 through an arc on the order of 105° between the lowered and raised positions as shown in broken lines in FIG. 1. Of course, while the linear actuator in its preferred form has been described as a hydraulic cylinder, it is fully contemplated that other and different devices such as, for example, an air cylinder or a motorized screw drive may be employed. As best seen in FIGS. 2 through 6, the boring and collecting unit 44 is pivotally carried for free swinging movement at the remote end of the sampling arm 38 so as to assume a vertical orientation regardless of the angular attitude of the arm. To that end, as will be seen in FIG. 6 a tubular sleeve 56 extending laterally from the sampling arm axially receives a bushing 58 within which a post 60 is journalled for rotation. The post is retained within the bushing as by a snap ring 62, and the bushing is retained within the sleeve by means of a set-screw 64 threaded through the sleeve and extending into an annular recess 66 within the bushing. The post, in turn, extends from a collar 68 affixed to a carrier plate 70. The boring and collecting unit 44 depends from a channel section 72 affixed to the carrier plate. It is contemplated that for purposes of cluster sampling, that is, collecting several samples within a small area at once, a plurality of the boring and collecting units may be mounted upon the sampling arm. The boring and collecting unit is designed so that as the sampling arm 38 is lowered the base of the unit will engage and be urged into contact with the surface of the soil, and the auger will then be urged into the soil to a limited, predetermined depth. Accordingly, slide rods 74 depend downwardly from the opposite flanges 76 of the channel section 72, and extend slidably through openings 78 in wing extensions 80 of a base plate 82. Nuts 84 threaded on the ends of the slide rods beneath the base plate retain the base plate on the rods. Compression springs 86 surrounding the slide rods 74 cooperate with depth sleeves 88 on the slide rods for limiting the depth to which the auger will penetrate the soil as will be described. The depth sleeves can be readily removed and replaced with sleeves of selected lengths for permitting penetration to desired depths by the auger. A rotary power unit 90 is mounted on the channel section 72 with its output shaft 92 projecting downwardly through the web 94 of the channel section. In a preferred form as illustrated, the power unit may be a conventional hydraulic motor. However, other and different units such as, for example, air motors and electric motors may be employed as well. A drive shaft 96 of hexagonal or other irregular cross section is telescopically received within a mating recess (not shown) in the end of the output shaft 92 and secured therein as by a pin 98. The drive shaft is journalled within and is axially slidable through a bearing unit 100 mounted in a central opening in the base plate 82. For purposes of further stabilizing the drive shaft 96 as it rotates, a second bearing unit 102 is mounted in a bearing plate 104 affixed in spaced relation beneath the base plate 82 as by bolts 106 and spacers 108. The drive shaft is journalled within and axially slidable through the second bearing unit 102. The upper end of a soil auger 110 of suitable conventional design is telescopically received within an axially extending opening (not shown) at the lower end of the drive shaft and secured therein by a suitable pin or bolt 112. The auger may, of course, be of different types as called for by varying soil and operating conditions. Oppositely disposed pairs of side bars 114, secured at their upper ends by the bolts 106 to the bearing plate 104, depend downwardly and are affixed at their lower ends to a soil accumulator container 116 defined by side walls 118 and a trap door or floor 120. In order to permit dumping of collected soil the floor is connected to the wall 118 along its rear edge, that is, the edge opposite the operator's station, by a hinge 122. A latch mechanism is provided along the edge of the receptacle 116 opposite the hinge for selectively latching the trap door in a closed position and allowing it to pivot downwardly for discharging collected soil. The latch mechanism is adapted to be readily manipulated by the operator from the seat with the sampling arm in the retracted position as shown in FIG. 1, and may obviously comprise any of various devices commonly employed for similar purposes such as a spring clip or a spring loaded latch. In the illustrated embodiment a latch member 124 is pivotably carried within a sleeve 126 affixed to the side wall 118 of the receptacle. The latch member includes a finger 128 for engaging beneath the trap door 120 in its closed position and a handle extension 130 by which the latch member can be manually pivoted between the door retaining closed position as shown in FIGS. 3 and 4, and the door released position illustrated in broken lines in FIG. 1. In order to accommodate the soil auger 110 as it is extended from the receptacle 116 for gathering a soil sample, the trap door 120 is provided with a central opening 132 having a slightly greater diameter than that of the auger. The rotating auger may tend to displace soil laterally at the soil surface-trap door interface as it bores into the soil, particularly if the soil surface is uneven so that the trap door does not seat firmly against the surface. To obviate this condition an annular collar 134 is affixed within the aperture 132 or to the underside of the trap door surrounding the aperture. As the boring and collecting unit 44 is lowered by the arm 38, the collar is depressed into the soil to avoid any gap between the soil surface and the trap door, and thereby to prevent lateral displacement of soil by the auger. The rotating auger will, of course, tend to deflect laterally as its free end advances into the soil, and in so doing will engage the collar 134 or the wall surrounding the aperture 132 in the trap door. In order to reduce wear on the auger and prolong the life of the trap door and the annular collar, the collar may be fabricated of a hard wood or other suitable wear-resistant material. Also, a bushing 135 of similar material may be suitably mounted on the top surface of the trap door surrounding the central aperture 132. As best seen in FIGS. 1 and 2, for purposes of depositing collected soil samples in individual containers there is mounted on the base plate 34 in the path of the receptacle 116 as the sampling arm is retracted, a funnel-shaped collecting hopper 136. The hopper comprises side walls 138 converging downwardly to a central spout outlet 140. The hopper is mounted on the base 34 plate by means of leg assemblies 142 whereby the outlet from the spout is sufficiently elevated to permit insertion of an open topped container 144 therebeneath. The spout outlet may also be provided with means for holding plastic or other types of bags for receiving the collected soil samples. A box 146 is mounted on a holder 148 affixed to the base plate 34 for storing a supply of the empty containers 144 and for receiving and storing filled containers. Both the funnel shaped hopper 136 and the box 146 are positioned so as to be readily accessible to the operator from the seat 24. The trap door 120 can likewise be operated with the receptacle 116 in the discharge position over the hopper. As heretofore indicated the cylinder 46 for operating the sampling arm 38 and the rotary power unit 90 may advantageously be hydraulically driven. To that end, the power unit 16 includes a hydraulic pump and reservoir unit 150 driven by a gasoline engine 152. The hydraulic pump provides fluid under pressure through a conduit 154 to a two way control unit 156 mounted along side the cylinder 46. The control unit is manually operable by a lever 158 to selectively supply fluid under pressure to and return fluid from the double acting cylinder 46 on opposite sides of a piston (not shown) connected to the piston rod 50 through conduits 160 and 162. Thus by manipulation of the lever 158, the piston rod can be selectively extended and retracted to move the sampling arm 38 through its range of motion as illustrated in FIG. 1. In order to operate the rotary power unit 90 of the boring and collecting unit 44, a conduit 164 delivers hydraulic fluid under pressure from the control unit 156 to a second two way control unit 166 conveniently mounted on the base plate 34. Conduits 168 and 170 connect the control unit to the rotary power unit 90 and provide a flow path for hydraulic fluid from the control unit through the power unit and back to the control unit. A control lever 172 on the control unit is manually operable by the operator for directing hydraulic fluid through the conduits 168 and 170 to selectively rotate the power unit 90, and thus the auger 110, in either direction. A hydraulic fluid return conduit 172 connects the control unit 166 with the pump and reservoir unit 150. As will be readily appreciated, separate hydraulic fluid supply and return conduits (not shown) may alternatively be provided between the pump and reservoir unit 150 and each of the two way control units 156 and 166 in place of interconnecting the control units by means of the conduit 164. Reviewing briefly operation of the invention, in preparation for collecting soil samples the depth to which sampling is desired is determined, and depth sleeves 88 of appropriate length are installed on the slide rods 74 below the compression springs 86. A supply of the sample boxes or containers 144, appropriately marked with field locations, is stored in the box 146 on the vehicle. The operator drives the ATV to a selected sampling location and, upon reaching the location, engages the rotary power unit 90 by means of the control lever 172 to rotate the soil auger 110 in the appropriate direction. Various procedures may be employed in selecting sampling locations. For example, it is contemplated that a global positioning system (not shown) may conventionally be employed for directing the vehicle to predetermined sampling locations. With the hinged trap door 120 closed and latched, the piston rod 50 is extended by manipulating the lever 158 to swing the sampling arm 38 downwardly and lower the boring and soil collecting unit 44 until the bottom or trap door engages the soil surface. As the arm is further lowered, the springs 86 are compressed to embed the annular collar into the soil and urge the trap door firmly against the soil surface. As the arm 38 is further lowered the springs continue to compress and the drive shaft 96 pushes the spinning auger into the soil. When the springs are fully compressed between the depth spacers 88 and the channel section 72, further penetration is prevented. The soil augerings are, of course, brought up into the receptacle 116 by the auger flighting. With the auger preferably still spinning the arm 38 is raised by manipulating the lever 158 to retract the piston rod 50. If a composite sample is to be collected, that is, if multiple borings are to be combined for a single sample, the arm need only be raised enough for the bottom of the unit 44 to clear any terrain and debris. The operator then moves the ATV to the next sampling location. The procedure is repeated for each individual sample collected in the composite. When sample collection is completed the piston rod 50 is retracted to retract the arm 38 over center to the position shown in broken lines in FIG. 1, with the receptacle 116 directly over the funnel-shaped hopper 136. With the receptacle thus positioned over the hopper, rotation of the auger is discontinued. The operator then releases the latch member 124 to open the trap door 120. The collected soil drops into the hopper and subsequently into the container 144. Any soil which may tend to cling to the auger or receptacle 116 can be easily manually dislodged to drop into the container. Also, the auger may be rotated in the opposite direction to assist in dislodging soil. The container 144 is then removed from beneath the hopper and closed, and placed in the storage box 146. The trap door is closed and latched by the operator and the sampling unit is ready to repeat the soil sample collecting procedure. It is to be understood that the forms of the invention herewith shown and described are to be taken as illustrative preferred embodiments only of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention.

A vehicle mounted mechanized soil sample collecting unit including a sampler arm pivotably affixed to a base mounted upon the vehicle. At its remote end the sampler arm pivotably carries a soil auger and soil accumulator container. An actuator is coupled to the sampler arm for swinging the arm between a lowered, soil-collecting position and a retracted container discharge position. A power unit rotates the soil auger, which is adapted to advance through the bottom of the container and into the earth as the container engages the surface of the earth upon lowering of the sampler arm. As the auger rotates the soil sample is drawn upwardly into the accumulator container by the auger flights. With the sampler arm in the retracted position the accumulator container is positioned over a funnel device into which collected soil is deposited through a bottom trap door of the accumulator container for reception in a sample container beneath the funnel outlet.

BACKGROUND OF THE INVENTION [0001] (a) Field of the Invention [0002] The present invention relates to a display system, and in more detail, to a display system that can select a two-dimensional (2D) display mode or a three-dimensional (3D) display mode by using Integral Imaging Technology (Integral Imaging, known as II, or Integral Photography, known as IP). [0003] (b) Description of the Related Art [0004] Lippmann, in 1908, first proposed using a lens array method with II, which is a kind of display system to achieve a 3D display, and this has since been gradually improved upon but this method cannot attract much public attention because of the limitation in the quality of pick up devices and display devices. Recently however, research has become brisk due to advances in camera devices that have high resolving power and display devices that have high resolution. [0005] A conventional 3D display device using II displays a captured image as a 3D image using a lens array, or displays a 3D image based on elemental images formed by computer graphics. [0006] However, the conventional 3D display system has a critical defect in that it can display only 3D images, not 2D images. SUMMARY OF THE INVENTION [0007] The present invention has been made in an effort to provide a display device convertible between 2D and 3D. [0008] Also, the present invention has been made in an effort to provide a convertible display device that can enhance the depth of an image based on II. [0009] According to one aspect of the present invention, a convertible display device comprises: an image processing unit that provides elemental images for display of a three-dimensional image or provides a two-dimensional image for display of a two-dimensional image; a transmission-type image display unit that shows the elemental images or the two-dimensional image provided by the image processing unit; an array forming unit that forms a point light source array including a plurality of point light sources, the light from the point light sources being transmitted to the transmission-type image display unit; and a variable diffuser that controls the diffusion rate of the light from the point light source array so that the image displayed by the transmission-type image display unit is displayed as a three-dimensional image or a two-dimensional image. [0010] In displaying a three-dimensional image, the variable diffuser controls the diffusion rate to be lower than a predetermined value, the image processing unit provides the elemental images for the three-dimensional image, and the transmission-type image display unit displays the elemental images. [0011] In displaying a two-dimensional image, the variable diffuser controls the diffusion rate to be higher than the predetermined value, the image processing unit provides and transmits the two-dimensional image as it is to the image display unit, and the transmission-type image display unit displays the two-dimensional image. ADVANTAGEOUS EFFECT [0012] The present invention provides a convertible display device that can display a 2D or a 3D image, depending on the mode, on a transmission-type display device by adjusting a diffusion rate of a variable diffuser. [0013] In particular, a 3D mode of the present invention has the conventional advantage of integral imaging, such as supporting continual perpendicular parallax or horizontally parallax within a fixed viewing angle based on the principle of integral imaging method. However, compared to the conventional integral imaging method, it can increase a cubic effect when displaying both a real 3D image and a virtual 3D image without adjusting a distance between a point light source array and a transmission-type display device according to the depth of the 3D image. [0014] Also, a 2D mode of the present invention has an advantage of displaying a 2D image with perfect resolution and field angle by using a transmission-type display device itself, similar to the structure of a general liquid crystal display, by illuminating the transmission-type display panel with diffusion light. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 shows the basic concept of conventional Integral Imaging (II). [0016] FIG. 2 shows the basic concept of Computer-Generated integral imaging (CGII). [0017] FIG. 3 shows the concepts of real Integral Imaging and virtual Integral Imaging. [0018] FIG. 4 shows the basic concept of the present invention. [0019] FIG. 5 shows a diagram of the 3D/2D convertible display device according to a first preferred embodiment of the present invention. [0020] FIG. 6 and FIG. 7 , respectively show a mechanism of the 3D mode and the 2D mode of the 3D/2D convertible display device according to the first preferred embodiment of the present invention. [0021] FIG. 8 shows how elemental images are generated when the 3D/2D convertible display device displays a 3D image according to the first preferred embodiment of the present invention. [0022] FIG. 9 shows a diagram of the 3D12D convertible display device according to a second preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS [0023] In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. [0024] First, Integral Imaging (II) will be described in order to understand the 3D/2D convertible display device according to the present invention. [0025] FIG. 1 shows the fundamental concept of conventional II. The system for achieving the II method basically includes two functional parts, a pick up part and a display part, as shown FIG. 1 . The pick up part is composed of a lens array that makes an elemental image of a three-dimensional object and a pick up device that saves the elemental image formed by the lens array. The display part is composed of a display device that displays the elemental image picked up by the pick up device and a lens array that forms and displays a three-dimensional image using the elemental image displayed at the display device. Each lens array is composed of a plurality of elemental lenses. [0026] In the pick up part, elemental images for the three-dimensional object are formed by each elemental lens of the lens array and saved by the pick-up device. In the display part, the process of the pick up part is reversed and the saved elemental images are displayed by the display device. The elemental images are integrated and displayed as a three-dimensional image at the position of the original three-dimensional object passing through the lens array. The integrated elemental images by the lens array can be called as an integrated image. [0027] CGII (Computer-Generated Integral Imaging), which generates an elemental image by a computer calculation instead of by the pick up process, is proposed. [0028] FIG. 2 shows the structure of a CGII system. FIG. 2 shows the basic concept of a CGII system. Elemental images, which have information of a virtual three-dimensional object, are generated by a computer and the images is transferred to a display device, for example a liquid crystal display (LCD) panel, that displays the three-dimensional image through a lens array. In this situation, the formed position of the integrated image alters according to the distance between the lens array and the panel of the display device, which can be easily shown by the following equation. [0000] 1 /d+ 1 /g= 1 /f   [Equation 1] [0029] In the above equation, d is the distance between the integrated image and the lens array, g is the distance between the lens array and the LCD panel, and f is a focal length of the elemental lenses that compose the lens array. [0030] When the distance between the lens array and the LCD panel is longer than the focal length of the elemental lens, the distance value between the formed image and the lens array is a positive number and then the integrated image is formed as a real image in front of the lens array (real image II). On the hand, when the distance between the lens array and the LCD panel is shorter than the focal length of the elemental lens, the distance value between the formed image and the lens array is a negative number and then the integrated image is formed as a virtual image at the back of the lens array (virtual image II). [0031] In FIG. 3 , the two kinds of display method, i.e., real image II and virtual image II, are shown for comparison. In the case of virtual image II, observers have the benefit of a wider viewing angle since the distance between the integrated image and the observer is longer than in that of real image II. As shown in FIG. 3 , the embodiment method of virtual image II is similar to that of real image II except that the elemental image of virtual image II is an erect image unlike the elemental image of the real image II. [0032] In the case of two kinds of II display methods, if the distance between the lens array and the LCD panel is fixed, then the integrated image is formed on a specific plane. Consequently, if the object to be displayed is a 3D object, the resolution of the image is optimized at the central depth plane of the 3D image. Resolution is decreased as the distance between the central depth plane and the image increases because the distance between the lens array and the LCD panel is set based on the central depth plane of the 3D object. The II method therefore has a limit of restricting a displayable thickness of a 3D object. Moreover, for real image II, the distance between the lens array and the LCD panel must be longer than the focal length of the lens array. For virtual image II, the distance between the lens array and the LCD panel must be shorter than the focal length of the lens array. Consequently, in a conventional II method, displaying a real image and a virtual image simultaneously is impossible. [0033] As shown in FIG. 1 and FIG. 2 , the observer must look at a 3D image formed and integrated by a lens array because the lens array is in front of the LCD panel in the conventional II method. Undoubtedly, it is possible to display a flat image on any depth plane but, in this case, the resolution and the viewing angle of the displayed image are significantly worse than those of conventional and commercial 2D display systems. [0034] Accordingly, the embodiment of the present invention provides a display device convertible between 2D and 3D. Also, in displaying a 3D image, the convertible display device can enhance the depth of the image based on the II. [0035] FIG. 4 shows the basic concept of the convertible display device according to an embodiment of the present invention. [0036] The embodiment of the present invention uses a point light source array and a transmission-type display device rather than the display device and the lens array of conventional II, and electrically controls the generation of the point light source array using a variable diffuser. [0037] The convertible display device according to the embodiment of the present invention shown in FIG. 4 includes an array forming unit 10 that forms a point light source array having a divergence angle, an image processing unit 20 that provides elemental images for display of a 3D image or provides a 2D image for display of a 2D image, a transmission-type image display unit 30 that shows the elemental images or the 2D image provided by the image processing unit, and a variable diffuser 40 that is placed in front of, or behind, the point light source array and controls the generation of the point light source array. The convertible display device further includes a mode selecting unit 50 that controls a diffusion rate of the variable diffuser 40 according to a mode. [0038] The image processing unit 20 computes and forms elemental images according to information for displaying a 3D image, or provides a 2D image, such as an image captured by an image capturing device, without special processing to the image display unit. That is, the elemental images may be images that the image processing unit 20 generates itself through a special process based on some information. The 2D image may be provided from the outside. [0039] The variable diffuser 40 is a device that electrically controls the diffusion rate of the incident light. The diffusion rate of the variable diffuser may be minimized when a 3D image is displayed, while it may be maximized when a 2D image is displayed. [0040] The mode selecting unit 50 may control the diffusion rate by inputting a voltage to the variable diffuser 40 . [0041] Now, a convertible display device according to a first embodiment of the present invention will be described based on the concept above. [0042] The first embodiment of the present invention provides a 3D/2D convertible display device in which a polymer-dispersed liquid crystal is used as an electrically variable diffuser and the array forming unit generates the point light source array by utilizing parallel light and a lens array. [0043] FIG. 5 shows a diagram of the convertible display device according to the first preferred embodiment of the present invention. [0044] In the convertible display device according to the first preferred embodiment of the present invention, the transmission-type image display unit 30 receives an image signal from the image processing unit 20 and displays it. The transmission-type image display unit 30 is a common 2D display device, such as a spatial light modulator or an LCD with the backlight unit removed. This embodiment uses a spatial light modulator as a transmission-type display unit. [0045] The array forming unit 10 includes a lens array 11 . The distance between the lens array 11 and the transmission-type image display unit 30 may be any length that is longer than the focal length of the lens array but shorter than twice the focal length of the lens array. The variable diffuser 40 may be located at any position between the lens array 11 and the transmission-type image display unit 30 or right behind the lens array 11 . Here, the transmission-type image display unit 30 is assumed to be g_lens_slm(f<g_lens_slm≦2f) distant from the lens array 11 with a focal length of f, and the variable diffuser 40 is assumed to be right behind the back of the lens array 11 . [0046] The convertible display of the first embodiment of the present invention has two action modes, a 3D mode and a 2D mode. Hereafter, the action of each mode will be explained. [0047] FIG. 6 and FIG. 7 , respectively show the mechanism of a 3D mode and a 2D mode of the convertible display device according to the first preferred embodiment of the present invention. [0048] First of all, FIG. 6 shows the action of the 3D mode. The diffusion rate is adjusted to the lowest value in the 3D mode. The diffusion rate may be controlled by applying a constant voltage to a PDLC (polymer-dispersed liquid crystal) when it is used as the variable diffuser 40 , as in the first embodiment. The diffusion rate of the variable diffuser 40 in the 3D mode should be small enough that almost all of the incident parallel light passes through the variable diffuser 40 without being diffused or scattered significantly. When the variable diffusion rate is small enough, the incident parallel light passes through the variable diffuser 40 and is focused at the focal plane of the lens array 11 . In this case, focuses of lenses of the lens array 11 are formed at the focal plane and then a point light source array DA composed of point light sources, the number of point light sources being the same as the number of lenses in the lens array 11 , is formed at the focal plane of the lens array 11 . The light emitted from the point light source array DA formed in this way builds a 3D image after passing through the transmission-type image display unit 30 . At this time, elemental images are generated by the image processing unit 20 and are displayed on the transmission-type image display unit 30 . The image processing unit 20 calculates elemental images from the 3D information of the 3D image and transmits the elemental images to the transmission-type image display unit 30 . A specific explanation of the generation of the elemental images in the image processing unit 20 is given below. [0049] If the transversal position of a point P on the 3D image is (x, y) in the Cartesian coordinate system, the depth (i.e., the distance between the plane of the point light source array and the position of the image) is z (z being positive when P is in front of the plane of the point light source array and negative when P is behind the plane of the point light source array), the coordinate of the center of the point light source that is i th from the left and j th from the top is (pls_x[i][j], pls_y[i][j]) (this coordinate is the same as the central coordinate of the elemental lens that is forming the point light source), the distance in the X direction between each point light source of the point light source array is Lx, the distance in the y direction between each point light source of the point light source array is Ly (Lx is the same as the distance in the X direction between the central coordinates of the elemental lenses and Ly is the same as the distance in the Y direction between the central coordinates of the elemental lenses), the focal length of the lens array is f, and the distance between the lens array and the transmission-type image display unit is g_lens_slm. Since the point light source array is generated on the focal plane of the lens array, the distance ‘g_pls_slm’ between the point light source array and the image display unit is calculated by the following equation. [0000] g — pls — sim=g _lens — slm — −f   (Equation2) [0050] Here, the elemental image of the point P of the object for the point light source that is i th from the left and j th from the top becomes E_ij, and the position coordinate is expressed as in Equations 3 and 4. [0000] Elemental_image — x[i][j]=pls — x[i][j ]+(( g — pls — slm ) z )*( x−pls — x[i][j ])  (Equation 3) [0000] Elemental_image — y[i][j]=pls — y[i][j ]+(( g — pls — slm )/ z )*( y−pls — y[i][j ])  (Equation 4) [0051] The equations above can be easily obtained using the proportional relation of the two similar triangles shown in the FIG. 8 which shows the concept of the elemental image generation. However, the point E_ij, which is obtained from Equations 3 and 4, cannot be the elemental image for the point light source that is i th from the left and j th from the top unless it satisfies the following two conditions. [0000] − Lx/ 2<Elemental_image — x[i][j]−pls — x[i][j]<Lx/ 2  (Condition 1) [0000] − Ly/ 2<Elemental_image — y[i][j]−pls — y[i][j]<Ly/ 2  (Condition 2) [0052] If the calculated value of Equation 3 and Equation 4 does not satisfy both Condition 1 and Condition 2 simultaneously, then the E_ii point cannot be the elemental image of point P. Making the elemental image using all the calculated points of Equation 3 and Equation 4 without considering Condition 1 and Condition 2 critically decreases the quality of the displayed 3D image by mutual interference in the elemental images of the point light sources. In this way, we can generate the elemental image for point P and we can get all the elemental images by executing the above calculation for all points of the 3D object and overlapping the calculated elemental images for each point. In the overlapping of the elemental images of each point of the 3D image, we must overlap the elemental images by retrograde order of depth, i.e., the elemental image for a larger z being placed on the elemental image for a smaller z. By the above process, we can prevent the 3D image from becoming pseudoscopy, that is, the same as with conventional computer-generated integral imaging (CGII) or computer-generated integral photography (CGIP). Another remarkable point of the embodiment of the present invention is that we do not consider the position of the observer when calculating the elemental image. The above remarkable point means that the 3D mode of the convertible display device according to the embodiment of the present invention has distinction from the conventional multi-view 3D display method using a point light source array. Namely, the conventional multi-view 3D display method using a point light source array assumes positions of the observer and generates images to be displayed on the transmission-type image display unit so that the observer can observe a corresponding image at each position. Then, the observer feels the cubic sense by binocular perspective. However, in the 3D mode of the convertible display device according to the embodiment of the present invention, the light from the point light source array is transmitted to the transmission-type image display unit. Then the light is appropriately modulated by the elemental image and formed to a real 3D image in a space. Therefore the observer feels perspective continuously in a fixed viewing angle regardless of the position of the observer. Accordingly, the 3D mode of the convertible display device according to the embodiment of the present invention is not a general multi-view 3D display but a sort of integral imaging. The general multi-view 3D display method concluding the way using point light source array considers the position of the observer (i.e., the position and the number of viewing points) when calculating an image to be displayed at the transmission-type image display unit. However, the 3D mode of the convertible display device according to the embodiment of the present invention only considers the information of the 3D object not the position of the observer as mentioned above when generating the elemental images. [0053] The elemental images generated by this method are displayed at the transmission-type image display unit 30 and the light from the point light source array DA generated by the lens array 11 is appropriately modulated according to the elemental images displayed at the transmission-type image display unit 30 , thereof forming a 3D image. [0054] In the conventional integral image method, a 3D image is displayed by forming the elemental image using the lens array, and then the depth, direction, and position (z) of 3D image to be optimized and displayed according to the distance between the lens array and the image display unit is induced by Equation 1. In that case, the 3D image having limited depth can be displayed at around the position (z). Moreover, when displaying a real 3D image (z>0), the distance between the lens array and the image display unit should be longer than the focal length of the lens array according to Equation 1, and when displaying a virtual 3D image (z<0), the distance between the lens array and the image display unit should be shorter than the focal length of the lens array. Therefore, the conventional integral image method can only display one of a real 3D image and a virtual 3D image. However, according to the 3D mode of the convertible display device of the embodiment of the present invention, a 3D image is displayed not by formed images of elemental images but modulating light from point light sources through elemental images. Therefore, regardless of the depth, direction, and position (z) of the 3D image, and moreover, regardless of whether it is a real image (z>0) or a virtual image (z<0), the distance between the lens array and the image display unit is fixed. However, the elemental images displayed on the transmission-type image display unit can be altered and therefore the 3D mode of the convertible display device can display a real 3D image and a virtual 3D image simultaneously without any mechanical movement. As a result, the 3D mode of the convertible display device according to the embodiment of the present invention has a merit of greatly increasing a depth sense of a 3D image when compared with conventional integrated image processing. [0055] The operation of a 2D mode of the convertible display according to the present invention will now be described. [0056] FIG. 7 shows the operation of a 2D mode of the convertible display device according to the first preferred embodiment of the present invention. The 2D mode displays a 2D image and a diffusion rate is adjusted to a larger value in the 2D mode. [0057] The parallel light coming from the rear is diffused by a variable diffuser and transmitted through the lens array in a condition of being irregularly spread in a wide angel without a regular direction. In this case, the distance between the variable diffuser and the lens array 11 is too short so that the lens array 11 cannot form the light spread by the variable diffuser 40 but only transmit it to the transmission-type image display unit 30 . Therefore the light spread without a regular direction illuminates the transmission-type image display unit 30 and the observer just looks at a 2D image displayed on the transmission-type image display unit 30 . As mentioned above, the image processing unit 20 in the 2D mode just transmits the 2D image to the transmission-type image display unit 30 without any special image processing and the observer just looks at the 2D image. In the embodiment of the present invention, the structure of the spread light illuminating the image display unit is the same as a general 2D display using a transmission-type display panel (e.g., an LCD). Therefore the observer can look at a 2D image with perfect resolution and viewing angle on the transmission-type image display unit 30 of the convertible display according to the embodiment of the present invention used in the 2D mode. [0058] As mentioned above, in the first embodiment of the present invention, a 3D image with improved depth sense and a 2D image with a high resolution can be displayed by generating a point light source array using a lens array and parallel light and electrically adjusting the diffusion rate of a variable diffuser. [0059] Next, a second embodiment of the present invention will be described. [0060] The second embodiment of the present provides a method of structuring a 3D/2D convertible display by using a point light source array generated using an optical fiber array instead of the lens array and parallel light. [0061] FIG. 9 shows the convertible display device according to the second embodiment of the present invention. As shown in FIG. 9 , the structure of the convertible display device according to the second embodiment of the present invention is the same as that of the first embodiment except for the structure of the array forming unit 10 . [0062] In the convertible display device according to the second embodiment of the present invention the array forming unit 10 includes an optical fiber array 12 having at least one optical fiber transmitting light from one or more point light sources, instead of the lens array of the first embodiment. The variable diffuser 40 is located between the tip of the optical fiber array 12 and the transmission-type image display unit 30 . [0063] The light from the point light sources is transmitted to the transmission-type image display unit 30 through the optical fiber array 12 . At this time, the light illuminated to the optical fiber array 12 from the point light sources moves according to the optical fibers of the optical fiber array 12 and spreads at the tips of the optical fibers. Therefore the tip of each optical fiber may be considered to be one point light source. The number of optical fibers and the distance between the optical fibers are respectively the same as the number of point light sources and the distance between the point light sources. Also, the distance between the tip of the optical fiber array 12 and the transmission-type image display unit 30 is the same as the distance ‘g_pls_slm’ in the first embodiment between the point light source array and the image display unit because the surface generated by the point light source array is the same as the surface formed at the tip of the optical fiber array. [0064] Therefore the diffusion rate of the variable diffuser 40 may be lowest in the 3D mode of the convertible display device according to the second embodiment of present invention and the image processing unit 20 displays a 3D image by generating the elemental image as in the first embodiment using the Equations 3 and 4 and the Conditions 1 and 2 and then displaying the 3D image at the transmission-type image display unit 30 . In the 2D mode, the light from the tip of the optical fiber array 12 is diffused with an increased diffusion rate by the variable diffuser 40 to illuminate the transmission-type image display unit 30 and so the convertible display device can display a 2D image on the surface of the transmission-type image display unit 30 . [0065] While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

A display device convertible between two-dimensional (2D) and three-dimensional (3D) is provided. The convertible display device is based on integral imaging (II) or integral photography (IP) and displays 2D or 3D images. An image processor generates and transmits elemental images to reconstruct a 3D image or transmits a desired two-dimensional image, and a transmission-type display device displays the image received from the image processor. At this time, a diffusion rate (or haze rate) of light illuminated from a point light source array that is made of a plurality of point light sources is controlled by a variable diffuser and as the light illuminates the transmission-type display device, the device displays 2D or 3D images. According to the present invention, a point light source array is generated by controlling a variable diffuser and as a result a display device convertible between 3D and 2D is achieved. Moreover, a 3D image can be made by spatially modulating the light illuminated from a point light source array and, thereby, an available depth region is dramatically improved.

CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. provisional application 61/586,134 filed Jan. 13, 2012 and hereby incorporated in its entirety by reference. FIELD OF THE INVENTION [0002] The present invention relates to washing appliances such as dishwashers and clothes washing machines which provide a sealable chamber for washing, and in particular to an air handling system for reducing humidity in such appliance chambers. BACKGROUND OF THE INVENTION [0003] Dishwashers, such as those found in many homes, provide a washing chamber holding one or more racks sized to support eating utensils and cookware for cleaning. The washing chamber may be sealed by a door opening at the front of the washing chamber to allow loading and unloading of the chamber. The door is closed during a washing cycle to prevent the escape of water sprayed within the volume of the washing chamber during the washing of items placed in the racks. Upon completion of the washing cycle, a drying cycle is initiated during which water is drained from the washing chamber and moist air is discharged through a vent. Cool air, pulled by convection or by a fan into the chamber through a lower vent, flows upward, augmented by natural convection to dry the heated dishes. [0004] Recent dishwasher designs may employ a one-piece tub, for example of stainless steel, which defines the washing chamber and, when closed by the door, is sealed from communication with the outside air. The sealed nature of this chamber makes the promotion of air circulation for proper venting particularly difficult. [0005] U.S. Pat. No. 7,887,643 entitled: “Dishwasher With Counter-Convection Air Flow”, assigned to the same assignee as the present invention and hereby fully incorporated by reference, describes a downdraft venting system in which low-turbulence down-flow is created within the washing chamber to more efficiently remove moisture-laden air from the washing chamber and dishes. In one embodiment, a relatively small fan placed at the top of the washing chamber draws dry air into the washing chamber to push moist air out of existing vents near the bottom of the washing machine door. [0006] The greater efficiency of this downdraft design in removing moisture from the washing chamber and contained dishes can create condensation problems when high humidity air is exhausted from the dishwasher and contacts cool surfaces, such as a metal-faced dishwasher door. This condensation may cause the undesirable collection of water on surfaces near the vent outlet. [0007] U.S. Pat. No. 7,909,939, entitled: “Humidity Reducing Exhaust Duct for Dishwasher”, assigned to the same assignee as the present invention and hereby fully incorporated by reference, describes an exhaust duct designed to handle the higher humidity air provided by more efficient low turbulence down-flow venting or the like. The duct provides a mixing chamber to mix cool dry air with the warm humid air and a reservoir for accumulating condensation before exit from the duct into the environment around the dishwasher. This reservoir may be dried by continued fan operation after the venting is complete. [0008] Clothes washing machines, and in particular water-saving, front-loading washing machines, may provide a sealed door preventing the escape of water during the washing cycle. If this door is closed after completion of the washing cycle and removal of the washed clothes, residual humidity can be trapped in the washing chamber, risking the growth of mold or the generation of musty odors. SUMMARY OF THE INVENTION [0009] The present invention provides an improved mixing chamber for a humidity reducing duct system for dishwashers, washing machines, or other similar appliances. The mixing chamber employs a jet pump allowing a single fan to promote the mixing of moist air from the washing chamber with dry outside air. In one embodiment, an electric blower provides high velocity jet into the mixing chamber which draws moist air from the washing chamber as displaced by dry air diverted from the same electric blower. [0010] Specifically, the present invention provides a vent system for a washing appliance having a mixing chamber providing a first and second inlet spaced from an outlet of the mixing chamber, the first and second inlet configured to provide a jet pump action where a first airstream through the first inlet draws a second airstream through the second inlet to mix therewith and be discharged through the outlet. First ducting communicates between the mixing chamber and a washing chamber of a washing appliance so that one of the first and second inlets receives moist air through the ducting from the mixing chamber, and the other of the first and second inlets receives relatively drier air from outside of the washing chamber of the washing appliance. An electric blower communicates with the mixing chamber to produce a pressure difference generating the first airstream. [0011] It is thus a feature of at least one embodiment of the invention to provide for a powered venting of a washing appliance washing chamber in which a single fan can provide for the movement and intermixing of both dry and moist airstreams. [0012] The ducting may attach to the second inlet and the electric blower may be positioned at the first inlet to intake the drier air from outside the air washing chamber and discharge it through the first inlet. [0013] It is thus a feature of at least one embodiment of the invention to provide design that allows the electric blower to be isolated from moist air. [0014] The electric blower may communicate with the first inlet through a bifurcated passageway having a first branch attached to the first inlet and a second branch communicating with second ducting communicating between the second branch and the washing chamber of the washing appliance. [0015] It is thus a feature of at least one embodiment of the invention to provide a positive displacement of moist air from the washing appliance with a single fan that moderates pressure build up within the washing chamber by balancing airflows and pressures into and out of the washing chamber. [0016] The first ducting may communicate with the washing chamber at a position substantially below all racks holding items for washing in the washing chamber and the second ducting may communicate with the washing chamber at a position substantially above all racks holding items for washing in the washing chamber to provide for a counter-convection airflow. [0017] It is thus a feature of at least one embodiment of the present invention to provide superior moisture extraction from the washing appliance washing chamber as obtained by counter-convection nonturbulent airflow. [0018] The mixing chamber may include a condensation reservoir for collecting water condensing out of the moist air. [0019] It is thus a feature of at least one embodiment of the invention to extract and retain excess moisture in the vented air to prevent condensation outside of the washing appliance and vent system. [0020] The electric blower may be displaced upward on the mixing chamber with respect to the condensation reservoir. [0021] It is thus a feature of at least one embodiment of the invention to provide a condensation system that shields the electric motor and fan from moisture. [0022] The mixing chamber may provide for a substantially horizontal airflow. [0023] It is thus a feature of at least one embodiment of the invention to provide a system that promotes a directing airflow away from the washing appliance adaptable to a shallow extended horizontal moisture collection reservoir. [0024] The outlet of the mixing chamber may be preceded by a passageway directing airflow out of the outlet at an upward angle from horizontal during operation of the mixing chamber. [0025] It is thus a feature of at least one embodiment of the invention to provide a venting system that may fit beneath the washing appliance to discharge moist air therefrom while reducing condensation on the floor. [0026] The vent system may use only a single fan communicating with the mixing chamber. [0027] It is thus a feature of at least one embodiment of the invention to provide for a low cost but effective venting system that reduces exhausted moisture. [0028] The electric blower may include a brushless DC motor and a centrifugal fan. [0029] It is thus a feature of at least one embodiment of the invention to permit the use of energy-efficient low noise fans. [0030] The ducting may be polymer tubing presenting inwardly extending circumferential ridges over an axial length of at least 12 inches. The polymer tubing may have an average internal diameter of between 0.6 and two inches. [0031] It is thus a feature of at least one embodiment of the invention to provide for noise reduction with respect to noise escaping from the washing appliance during washing operations without the need for mechanically actuated doors over the vent openings. The inward ridges on the ducting provide an acoustic muffler without undue airflow resistance. [0032] The inwardly extending ridges may be in the form of circumferential pleats in an outer wall of the tubing. [0033] It is thus a feature of at least one embodiment of the invention to provide ducts that provide both acoustic muffling and improved flexibility. [0034] The tubing may be formed to provide at least one upwardly extending loop in the tubing between the chamber outlet and the exhaust port. [0035] It is thus a feature of at least one embodiment of the invention be able to position the vent connections to the washing appliance without concern for escaping water which is returned by the trapping action of the loops. [0036] Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features. BRIEF DESCRIPTION OF THE DRAWINGS [0037] FIG. 1 is a left-side perspective view of a washing chamber housing of a dishwasher (removed from outer dishwasher structure)generally representative of a washing appliance, showing the dishwasher door in phantom and further showing the position of a first vent of the present invention on the left vertical wall of the washing chamber housing; [0038] FIG. 2 is a right-side perspective view of a washing chamber housing showing the position of a second vent of the present invention on the right vertical wall of the washing chamber housing; [0039] FIG. 3 is a simplified elevational front cross-sectional view of the washing chamber showing airflow between the first and second vents per FIGS. 1 and 2 and showing an alternative second vent location; [0040] FIG. 4 is a fragmentary partial cross-section of a vent tube connected to the vents providing a corrugated surface for noise suppression and flexibility; [0041] FIG. 5 is a perspective view of the vents and tubes connected to a blower assembly with the washing chamber removed for clarity; [0042] FIG. 6 is a detailed perspective view of the blower assembly showing positioning of a single upstream blower; [0043] FIG. 7 is a figure similar to FIG. 6 showing the blower assembly with the top housing of the blower assembly removed to reveal a jet pump; [0044] FIG. 8 is a simplified diagram of the airflow paths provided by the venting system of the present invention; and [0045] FIG. 9 is an elevational side cross-section of a discharge vent of the blower assembly showing an internal reservoir and an angle of the discharge vent to project humid air away from the floor and door. [0046] Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0047] Referring now to FIGS. 1 and 2 , a dishwasher 10 may include a washing chamber 12 into which dishes and cutlery 14 may be placed for washing on racks 16 . The washing chamber 12 may be defined by a generally rectangular housing 15 , for example, of drawn stainless steel or injection molded thermoplastic, providing a single piece sealable volume open at the front to be covered by a door 18 that seals against a front lip 20 of the housing 15 . [0048] A first vent 22 providing an opening through the left side wall of the housing 15 may be positioned at a level 24 above the highest rack 16 and preferably at or above the level of projecting dishes and cutlery 14 . [0049] Referring now to FIGS. 2 and 3 , a second vent 26 also providing an opening through the housing 15 , but on a right side wall of the housing 15 , may be positioned at a level 28 below the lowermost rack 16 . Airflow 30 between the first vent 22 and the second vent 26 will be generally conducted in a downdraft or downward direction to flow smoothly and completely across the dishes and cutlery 14 in the racks 16 . In an alternative embodiment, the second vent 26 ′ may be placed on the left side wall of the housing 15 also at level 28 to create a functionally similar downdraft airflow 30 ′ completely across the dishes and cutlery 14 in a slightly arcing or helical pattern. [0050] Referring now to FIGS. 1 , 2 , and 4 , the vents 22 and 26 may be connected to flexible tubes 32 and 34 respectively. These tubes 32 and 34 proceed upward from the vent openings of vents 22 and 26 by a short length (3 to 6 inches) and then downward to connect with the blower assembly 36 as will be described below. These short upward sections provide a water trap causing water passing through the vent 22 or vent 26 from the volume of the housing 15 , during the washing cycle of the dishwasher 10 , to be trapped in the short upward length of the tubes 32 and 34 to drain back into the housing 15 . This trap eliminates the need for an electrically controlled door closing the vents 22 or 26 during the washing cycle. [0051] The tubes 32 and 34 are preferably corrugated plastic tube having a diameter of 0.6 to 1¾ or 2 inches and an axial length of several feet (and at least 12 inches). The corrugations are characterized by a bellows construction of alternating larger and smaller outside and inside diameters. This corrugation allows increased flexibility of the tubing and importantly decreases the noise transmitted through the tubing from the volume of the housing 15 during the washing cycle, in the manner of a muffler, to prevent excess noise from escaping the housing 15 during the washing cycle even in the absence of a door covering the vents 22 and 26 during the washing cycle. It is believed that the corrugations further provide for improved water condensation both in terms of the increased area, the heat conduction of the thinwall plastic material, and the turbulence provided by the corrugated surface. [0052] Referring now to FIG. 5 , the tubes 32 and 34 pass from respective vents 22 and 26 to the blower assembly 36 and mixing chamber 37 (as shown in FIG. 1 ) positioned beneath the housing 15 . The blower assembly 36 includes a blower 38 configured to provide air as indicated by arrow 40 through tube 32 and out of vent 22 and to draw air as indicated by arrow 42 from vent 26 into the mixing chamber 37 to exit an exhaust slot 44 in the mixing chamber 37 positioned beneath the door 18 to the front of the housing 15 as shown in FIG. 1 . The flow of air into the volume of the housing 15 from vent 22 may be substantially matched to the air drawn from the volume through vent 26 to prevent excess pressure buildup in the volume of the housing 15 such as may promote leakage of water out of the door seals. [0053] Referring now to FIGS. 6 , 7 and 8 , the blower 38 may provide a generally centrifugal pump having an impeller 46 rotating about a vertical axis as driven by a motor 47 , the impeller 46 having radially extending vanes 48 and fitting within an involute-like housing 50 . In one embodiment, the motor 47 is a brushless DC motor having a permanent magnet rotor to provide for long life and low noise operation. [0054] Rotation of the impeller 46 draws dry and cool air into an axial inlet 52 from outside of the housing 15 and exhausts this air from an exhaust opening 54 into a bifurcated coupling dividing the exhausted air into two diverging branches. A first branch provides a relatively lower pressure airstream through a dry air conduit 56 leading to tube 32 and to the washing chamber 12 . [0055] A second branch of the air exiting the exhaust opening 54 provides a relatively higher pressure airstream diverted to pass through a nozzle 58 communicating with a moist air conduit 60 joined at one end with the tube 34 and at the other end with an exhaust slot 44 providing an outlet of the mixing chamber 37 . The nozzle 58 provides an exit port 62 of high velocity air adjacent to the moist air conduit 60 and directed along an axis of the moist air conduit 60 into the mixing chamber 37 toward the exhaust slot 44 . The high-pressure stream from the nozzle 58 provides a jet pump that draws air from tube 34 to exhaust through the exhaust slot 44 providing essentially a pumping action while shielding the blower 38 from contact with any moisture from the humid air. [0056] The term “jet pump” is intended to generally include pumps that operate to cause the movement of a pumped stream of fluid as affected by motion of a pumping stream of fluid without moving mechanical elements such as may operate under the venturi principle or in the manner of an eductor-jet pump or injector pump all of which create a low pressure zone to draw a fluid from a source reservoir. [0057] The air exiting the exit port 62 further mixes with the humid air from the tube 34 to reduce its humidity and temperature before that air exits from the exhaust slot 44 . [0058] Referring now to FIG. 9 , the portion of the moist air conduit 60 near the exhaust slot 44 tips upward by an angle “A” of approximately 10 to 35 degrees with respect to a horizontal plane of the floor 64 to guide the residual humidity of the air being exhausted through exhaust slot 44 away from the floor 64 and the door 18 to reduce condensation thereon. This upward sloping of the exhaust slot 44 creates a reservoir area 66 in a bottom wall of the mixing chamber 37 which collects water precipitating in the moist air conduit 60 caused by its lowered temperature in the mixing with air from the nozzle 58 (shown in FIG. 7 ). This liquid in the reservoir area 66 may be dried by running the blower 38 for a period of time after the reservoir area 66 of the washing chamber 12 is fully dried so as to prevent the accumulation of water for any period of time under the control of the cycle timer (not shown). [0059] The blower 38 may be driven by a permanent magnet DC motor or other motors of types well known in the art and provides generally a high-pressure operation that reduces fan noise by reducing the necessary rotational velocity of the fan impeller 46 . [0060] Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. [0061] When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. [0062] References to an electric blower can be understood to include propeller type fans, squirrel cage type centrifugal air pumps, and the like unless otherwise noted. [0063] It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties. Various features of the invention are set forth in the following claims. It should be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth herein. The invention is capable of other embodiments and of being practiced or carried out in various ways. Variations and modifications of the foregoing are within the scope of the present invention. It also being understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention.

A humidity reducing vent for a washing appliance such as a dishwasher or washing machine employs a jet pumping action allowing a single electric blower to move and mix humid air exhausted from the washing appliance washing chamber and external dry air streams together prior to discharge so as to reduce condensation outside of the washing appliance.

BACKGROUND OF THE INVENTION This application relates generally to injection molding apparatus and more particularly to injection molding apparatus having a cavity insert with a cooling fluid flow channel therein. Injection molding apparatus having cooling fluid channels or conduits are well known. For instance, the applicant's U.S. Pat. No. 5,427,519 which issued Jun. 27, 1995 shows a thermal setting application wherein a cooling fluid channel extends around a central liquid molding material channel in a nozzle. The applicant's U.S. Pat. No. 5,443,381 which issued Aug. 22, 1995 shows hot runner apparatus having cooling fluid conduits extending through a gate insert. Canadian Patent Application Serial Number 2,228,931 filed Feb. 2, 1998 by Mold-Masters Limited is another example of a gate insert having helical cooling fluid conduits or passages. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to at least partially overcome the disadvantages of the prior art by providing a cavity insert with inner and outer portions integrally joined together with a cooling fluid flow channel extending between the inner and outer portions. To this end, in one of its aspects, the invention provides injection molding apparatus having a cavity with an outer surface extending in a mold and a hollow cavity insert having an inner surface mounted in the mold, wherein the inner surface of the cavity insert forms the outer surface of the cavity. The cavity insert has a hollow inner portion and a hollow outer portion integrally joined together. The outer portion has an inner surface and the inner portion has an outer surface. The inner portion fits inside the outer portion with the outer surface of the inner portion adjacent the inner surface of the outer portion. Either the outer surface of the inner portion or the inner surface of the outer portion has a groove therein to form a cooling fluid flow channel extending between the inner portion and the outer portion. The cooling fluid flow channel extends from a cooling fluid inlet to a cooling fluid outlet in a predetermined configuration around the cavity. Further objects and advantages of the invention will appear from the following description taken together with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a portion of a multi-cavity injection molding system showing a cavity insert according to a preferred embodiment of the invention, FIG. 2 is an exploded isometric view showing the three portions of the cavity insert seen in FIG. 1 in position for assembly, and FIG. 3 is a sectional view of the cavity insert seen in FIG. 2 with the three portions integrally joined together. DETAILED DESCRIPTION OF THE INVENTION Reference is first made to FIG. 1 which shows a portion of a multi-cavity injection molding system or apparatus used for molding beverage bottle preforms having an elongated fluid cooled hollow cavity insert 10 according to a preferred embodiment of the invention. In this configuration, a number of heated nozzles 12 are mounted in openings 14 in a mold 16 with the rear end 18 of each heated nozzle 12 abutting against the front face 20 of a steel melt distribution manifold 22 . Each nozzle 12 is heated by an integral electrical heating element 24 and has a thermocouple element 26 extending into its front end 28 to monitor and control the operating temperature. Each heated nozzle 12 has a cylindrical locating flange 30 seated in a circular locating seat 32 in the opening 14 . This provides an insulative air space 34 between the heated nozzle 12 and the surrounding mold 16 , which is cooled by pumping cooling water through cooling conduits 36 . The melt distribution manifold 22 is also heated by an integral electrical heating element 38 . The melt distribution manifold 22 is mounted between a manifold plate 40 and clamp plate 42 which are secured together by bolts 44 . The melt distribution manifold 22 is located by a central locating ring 46 and a number of insulative spacers 48 which provide an insulative air space 50 between it and the surrounding cooled mold 16 . A melt passage 52 extends from a central inlet 54 in an inlet portion 56 of the melt distribution manifold 22 and branches in the melt distribution manifold 22 to extend through a central melt bore 58 in each of the heated nozzles 12 . The melt passage 52 extends through a two-piece nozzle seal 60 aligned with a gate 62 extending through a cooled gate insert 64 to an elongated cavity 66 . This cavity 66 for making beverage bottle preforms extends between the cavity insert 10 and thread split inserts 68 on the outside and a cooled mold core 70 on the inside. The gate insert 64 and the cavity insert 10 are seated in an opening 72 in a cavity plate 74 through which cooling water lines 76 extend to the cooled gate insert 64 . The cooled mold core 70 has an elongated hollow inner part 78 extending inside an elongated hollow outer part 80 . The mold core 70 has an outer surface 82 extending from a dome shaped front end 84 to a rear end 86 . The outer surface 82 of the elongated mold core 70 has a front portion 88 and a rear portion 90 . The front portion 88 forms the inner surface 92 of the cavity 66 , and the rear portion 90 extends rearwardly from the cavity 66 through an opening 94 through a core lock member 96 which is secured to a core backing plate 98 by bolts 100 . The core lock member 96 in turn extends through an opening 102 through a slide member 104 and a wear plate 106 which is secured to a stripper plate 108 by screws 110 . Cooling fluid supply and return lines 112 , 114 extend in the core backing plate 98 and are connected respectively to a central cooling fluid duct 116 extending longitudinally through the inner part 78 and a cylindrical outer cooling fluid duct 118 extending between the inner part 78 and the outer part 80 of the mold core 70 . The rear portion 90 of the outer surface 82 of the mold core 70 has a tapered part 120 which tapers inwardly towards the rear end 86 of the mold core 70 . As can be seen, the opening 94 through the core lock member 96 has an inner surface 122 with a tapered part 124 which also tapers inwardly towards the rear end 86 of the mold core 70 and matches the tapered part 120 of the rear portion 90 of the outer surface 82 of the mold core 70 . The rear portion 90 of the outer surface 82 of the mold core 70 also has a threaded part 126 onto which a cylindrical nut 128 is screwed. The nut 128 is seated in a seat 130 in the rear face 132 of the core lock-member 96 and is tightened by a spanner wrench which fits in holes 134 to secure the mold core 70 to the core lock member 96 with the tapered part 120 of the outer surface 82 of the mold core 70 abutting against the matching tapered part 124 of the inner surface 122 of the opening 94 through the core lock member 96 . Also referring to FIGS. 2 and 3, the cavity insert 10 has an elongated hollow inner portion 136 , an elongated hollow outer portion 138 , and a base portion 140 . The outer portion 138 has an outer surface 142 and a cylindrical inner surface 144 . As can be seen, the outer surface 142 tapers inwardly towards the front and fits in the matching tapered opening 72 extending through the cavity plate 74 . The outer portion 138 also has a rear end 148 which fits in a circular seat 150 in the base portion 140 . The base portion 140 has holes 152 through which screws 154 extend into holes 156 in the cavity plate 74 to secure the cavity insert 10 in place. In this embodiment, the inner portion 136 of the cavity insert 10 has a cylindrical inner surface 158 which forms the outer surface 160 of the cavity 66 and an outer surface 162 with a groove 164 therein which fits inside the outer portion 138 , with the outer surface 162 of the inner portion 136 adjacent the inner surface 144 of the outer portion 138 . The groove 164 in the outer surface 162 of the inner portion 136 extends in a predetermined configuration to form a cooling fluid flow channel 166 extending between the inner portion 136 and the outer portion 138 from a cooling fluid inlet 168 and a cooling fluid outlet 170 , both of which extend through the outer portion 138 to supply and return lines 172 , 174 respectively in the cavity plate 74 . In this embodiment, the outer portion 138 of the cavity insert 10 is longer than the inner portion 136 to also receive the gate insert 64 therein. Reference is now made to FIGS. 2 and 3 in describing the method of making the cavity insert 10 according to the invention. First, the inner portion 136 , the outer portion 138 and the base portion 140 seen in FIG. 2 are machined of steel with the groove 164 shaped to provide turbulent flow extending in the outer surface 162 of the inner portion 136 . Then, a bead of nickel alloy brazing paste is applied around the circular seat 150 in the base portion 140 , and the inner portion 136 , the outer portion 138 and the base portion are assembled as seen in FIG. 3 . Another bead of nickel alloy brazing paste is applied around the front end 176 of the inner portion 136 . The assembled inner portion 136 , outer portion 138 and base portion 140 are then gradually heated in a vacuum furnace to a temperature of approximately 1925° F. which is above the melting point of the nickel alloy. As the furnace is heated, it is evacuated to a relatively high vacuum to remove substantially all of the oxygen and then partially backfilled with an inert gas such as argon or nitrogen. When the melt point of the nickel alloy is reached, it melts and flows by capillary action between the inner and outer portions 136 , 138 and the base portion 140 to integrally braze the three portions together to form the integral one-piece cavity insert 10 shown in FIG. 3 . Brazing them together this way in the vacuum furnace provides a metallurgical bonding between them to maximize the strength of the cavity insert 10 and prevent leakage of the cooling fluid from the cooling fluid flow channel 166 . In use, after the system has been assembled as shown in FIG. 1, electrical power is applied to the heating elements 24 , 38 to heat the nozzles 12 and the melt distribution manifold 22 to a predetermined operating temperature. A suitable cooling fluid such as water is also circulated by pumps (not shown) through the cooling conduits 36 in the mold 16 and the lines 76 in the cavity plate 74 leading to the gate inserts 64 . Usually a cleaner cooling fluid such as glycol is pumped in closed loop cooling systems through the supply and return lines 112 , 114 to circulate through the mold cores 70 and through the supply and return line 172 , 174 to circulate through the cavity inserts 10 . Pressurized melt from a molding machine (not shown) is then introduced according to a predetermined injection cycle into the central inlet 54 of the melt passage 52 of the melt distribution manifold 22 , from where it flows through the central melt bore 58 in each of the heated nozzles 12 and the two-piece nozzle seals 60 and through the gates 62 to fill the cavities 66 . After the cavities 66 are full, injection pressure is held momentarily to pack and then released. After a short cooling period, the mold 16 is opened to eject the product. After ejection, the mold 16 is closed and the injection pressure is reapplied to refill the cavity 66 . This cycle is repeated continuously with a cycle time dependent upon the size of the cavities 66 and the type of material being molded. While the description of the cooled cavity insert 10 having a cooling fluid flow channel 166 extending between integral inner and outer portions 136 , 138 has been given with respect to a preferred embodiment, it will be evident that various other modifications are possible without departing from the scope of the invention as understood by those skilled in the art and as provided in the following claims.

Injection molding apparatus having a cavity insert ( 10 ) with integral inner and outer portions ( 136, 138 ) having a cooling fluid flow channel ( 166 ) extending therebetween. In a preferred embodiment, the cooling fluid flow channel ( 166 ) is formed by a groove ( 164 ) machined in the outer surface ( 162 ) of the inner portion ( 136 ). This brings the cooling fluid flow closer to the cavity ( 66 ) and improves cooling efficiency and reduces cycle time.

FIELD OF THE INVENTION The present invention relates to amide derivatives of 2-(p-aminobenzyl)-butyric acid and esters thereof having the general formula (1) ##STR4## wherein R, R' together represent the group ##STR5## or R is a hydrogen atom and R' represents a group ##STR6## and R" is a hydrogen atom or a 1 to 6 C alkyl group, preferably an ethyl group. Said compounds can all be structurally derivatives from 2-(p-aminobenzyl)-butyric acid through amidation of the amine group and they form a novel class of hypocholesterolemizing and hypolipidemizing agents. DESCRIPTION OF THE PRIOR ART Drugs having a hypolipidemizing activity are known. Among these Fenbutyramide, Xenbucin and β-benzalbutyric acid can be cited, having the formula, respectively ##STR7## The above drugs however show a low activity. It is also known from the literature (Chapman J. M. et al, J. Med. Chem. 26: 237-243; 1983) that phthalimide and the derivatives thereof show hypocholesterolemizing activity, which however has not led to a commercial use due to the low level of such activity. It is also known that Bezafibrate ##STR8## and Clofibrate ##STR9## have the ability to decrease the hematic levels of cholesterol and triglycerides (see R. Zimmerman et al: Atherosclerosis 29: 477; 1978; M. M. A. Hassan, A. A. Elazzouny: Analytical Profiles of Drug Substances vol. 11; K. Florey, Ed. Academic Press New York; 1982, pages 197-224). Among the phthalimide derivatives, o-(N-phthalimido)acetophenone ##STR10## has been found to be more active than Clofibrate in reducing the serum cholesterol percentage and the triglyceride level. The o-(N-phthalimido)-acetophenone activity appears to occur possibly in various ways, of which the inhibiting activity in vivo is cited on the hepatic enzymes involved in the biosynthesis de novo of the triglycerides and moreover the ability to speed up the excretion of cholesterol with the bile and to decrease the cholesterol absorption at the intestinal level. Additional hypolipidemizing drugs of interest are Procetofene of formula ##STR11## as well as the compound ##STR12## which show a hypolipidemizing activity lower than that of Bezafibrate. SUMMARY OF THE INVENTION The compounds of formula (1) which are an object of the present invention, have shown to have a hypocholesterolemizing as well as hypolipidemizing activity higher than that of Bezafibrate and Clofibrate, together with an extraordinary low toxicity which makes said compounds extremely interesting from a therpeutic viewpoint. Accordingly, object of the present invention are the compounds of formula (1) as well as pharmaceutical compositions for lowering the lipid and cholesterol level in blood, containing a pharmaceutically effective amount of said compounds. DETAILED DESCRIPTION OF THE INVENTION The compounds corresponding to formula (1) wherein group R(R')N-- is a phthalimide group are represented by 2-(p-phthalimidobenzyl)-butyric acid of formula (2) ##STR13## and the ethyl ester thereof of formula (3) ##STR14## Further amide derivatives according to the present invention correspond to formulae (4), (5) and (6) ##STR15## The compounds (2), (3), (4), (5) and (6) show a particularly high hypocholesterolemizing and hypolipidemizing activity, as confirmed by pharmacological tests, the results of which are referred to hereinafter. Compound preparation The preparation of compounds (2), (4) and (5) was carried out starting from 2-(p-aminobenzyl)-butyric acid ethylester, as obtained by cathalytic reduction with hydrogen in the presence of 10% Pd/C of 2-(p-nitrobenzyl)-butyric acid ethylester, as described in the chemical literature (Lellman, E. Scheich C., 20, 438, 1887). Ethyl-2-(p-aminobenzyl)-butyrate forms the ethylester (3) by a fusion treatment with phthalic anhydride. This reaction can also be carried out in suitable high-boiling solvents in the presence of dehydrating agents, if any. The preparation of compound (4) was carried out starting again from ethyl 2-(p-aminobenzyl)-butyrate by reaction with p-chlorobenzoic acid chloride in anhydrous THF and in the presence of triethylamine. This reaction could also be carried out in a protic or aprotic medium in the presence of an organic or inorganic base depending on the medium which is used. The amidation of ethyl-2-(p-aminobenzyl)-butyrate with 4-(1-pyrryl)phenylacetic acid to obtain the ester (5) was effected in anhydrous THF in the presence of N,N'-carbonyldiimidazole. Acid (3) was obtained by alkaline saponifcation of ester (2) with 4% aqueous sodium hydroxide. Compound (6) was formed as an intermediate which provides acid (2) by heating above the melting point. ##STR16## EXAMPLES OF PREPARATION The preparation of compounds (2), (3), (4), (5) and (6) was practically effected as referred hereinafter: EXAMPLE 1 Preparation of 2-(p-aminobenzyl)-butyric acid ethyl ester 28 g of 2-(p-nitrobenzyl)-butyric acid ethyl ester are dissolved in 200 ml ethyl acetate. The solution is added with 1 g of 10% Pd/C and hydrogenated in a Parr apparatus until complete absorption of hydrogen. After filtering and evaporation from solvent about 25 g of product are obtained as a sufficiently pure oil for the successive reactions. EXAMPLE 2 Preparation of 2-(p-phthalimidobenzyl)-butyric acid ethyl ester (compound 3) A mixture of ethyl-2-(p-aminobenzyl)-butyrate (4.4 g) and phthalic anhydride (3 g) is heat melted until ceasing of water evolution (5 minutes). After cooling, the solid as obtained is crystallized from ethanol. Yield: 4.8 g (68.6%); m.p. 86°-87° C. Analysis: C 21 H 21 NO 4 (351.39) calc. %: C 71.78; H 6.02; N 3.99; found: C 71.64; H 6.19; N 4.10. EXAMPLE 3 Preparation of 2-(p-phthalimidobenzyl)-butyric acid (compound 2) A suspension of ethyl-2-(p-phthalimidobenzyl)-butyrate (4.2 g) in 18 ml NaOH 1N is reflux heated for one hour. After decoloration on bone black, the solution is made acidic with concentrated HCl. The so separated oil is extracted with ethyl acetate dried on anhydrous Na 2 SO 4 . By solvent evaporation a solid is obtained which, when recrystallized from benzene-ethyl acetate (1:1), provides 1.7 g of a compound with m.p. 133°-135° C. Such compound is 2-(p-phthalylaminobenzyl)-butyric acid (compound 6). Analysis: C 19 H 19 NO 5 (341.35) calc. %: C 66.75; H 5.61; N 4.10; found %: C 66.98; H 5.57; N 4.16. This acid, by heating above the melting point, is transformed into 2-(p-phthalimidobenzyl)-butyric acid (compound 2) after crystallisation from aqueous ethanol. Analysis: C 19 H 17 NO 4 (323.33) calc. %: C 70.56; H 5.30; N 4.33; found: C 70.85; H 5.57; N 4.16. EXAMPLE 4 Preparation of 2-[4-(p-chlorobenzamido)-benzyl]-butyric acid ethyl ester (compound 4). A solution of ethyl-2-(p-aminobenzyl)-butyrate (3.3 g) and triethylamine (1.5 g) in anhydrous THF (70 ml) is slowly (10 minutes) addioned with a solution of p-chlorobenzoylchloride (2.6 g) in 30 ml of anhydrous THF. It is stirred for an hour at room temperature, then filtered and the solution as obtained is vacuum evaporated. The obtained solid residue is crystallized from methanol providing 4 g amide with m.p. 119°-120° C. Analysis: C 20 H 22 ClNO 3 (359.89) calc. %: C 66.74; H 6.17; Cl 9.85; N 3.89; found: C 66.44; H 6.21; Cl 9.78; N 4.01. EXAMPLE 5 Preparation of 2-{4-[4-(1-pyrryl)-phenylacetamido]-benzyl}-butyric acid ethyl ester (compound 5). A solution of 4-(1-pyrryl)phenylacetic acid (3 g) in anhydrous THF (50 ml) is additioned with a solution of carbonyldiimidazole (2.9 g) in THF (80 ml). After 45 minutes a solution of ethyl-2-(p-aminobenzyl)-butyrate (3.3 g) in THF (30 ml). is added. It is reflux heated for an hour, then dried and the residue is dissolved in dichloromethane. The organic solution is washed, first with NaOH 1M, then with HCl 1M and lastly with water. After drying on anhydrous sodium sulfate it is filtered and dried. A yellow solid (1.4 g) is obtained which melts at 100°-102° C. Analysis: C 25 H 28 N 2 O 3 (404.49) calc. %: C 74.23; H 6.98; N 6.93; found: C 74.28; H 6.97; N 7.0l. PHARMACOLOGICAL PROPERTIES From tests effected with amide derivatives of 2-(p-aminobenzyl)-butyric acid and the esters thereof corresponding to the general formula (1), it results that such compounds have pharmacological properties suitable for therapeutic utilization in some pathological conditions. In particular the experimental tests have been effected with the compounds (2), (3), (4), (5) and (6). The preparations administered "in vivo" by oral route, comprise a 0.5% suspension of carboxymethylcellulose in a neutral pH normal physiological saline for the compounds (3), (4) and (5), while for the compounds (2) and (6) the preparation comprises a solution in NaOH (0.1N) at pH 7-7.5. The compounds of the invention have shown a high hypolipidemizing activity. This pharmacotherapeutic effect was obtained with dosages and methods of administration which have not caused significant toxic effects. The hypolipidemizing activity was compared with Bezafibrate and Clofibrate. HYPOLIPIDEMIZING ACTIVITY The hypolipidemizing activity of the substances under test was evaluated as the ability to decrease the hematic levels of triglycerides and total cholesterol in animals made hyperlipidemic by administration of Triton (antihyperlipidemic agents, J. N. Moss, Screening Methods in Pharmacology, Ed. Robert A. Turner and P. Hebborn, volume II, Academic Press, pages 121-143). The test was carried out on two animal species: rat and mouse. Male Wistar rats and Swiss mice were used, held at a normal diet, the former weighing 200-260 g, the latter weighing about 26-30 g. The compounds (2), (3), (4), (5) and (6) and the Bezafibrate and Clofibrate of control were administered per os at a dose of 500 mg/kg, simultaneously with a 10% solution in normal saline of Triton WR-1339 endoperitoneally at a rate of 2 ml/kg body weight. After treatment, the animals were divided into lots of eight, and held fasting for 18 hours and then sacrificed. The hematic levels of triglycerides total cholesterol are measured on the serum by enzymatic methods (Test-Combination Triglycerides, Boehring Mannheim GmbH) and and colorimetric methods (Test-Combination Cholesterol, Boehring Mannheim GmbH). The results on the hypolipidemizing activity of the compounds under test in rat and mouse are referred in tables I and II. TABLE I______________________________________Hypolipidemizing activity in rate of the amidederivates of 2-(p-aminobenzyl)-butyric acid andesters thereof: Total cholesterol TriglyceridesCompounds % mg % variation % mg % variation______________________________________Carrier 270 -- 520 --Bezafibrate 210 -22 415 -20Clofibrate 218 -19 420 -19Compound (2) 176 -35 360 -31Compound (3) 189 -30 390 -25Compound (4) 200 -26 400 -23Compound (5) 205 -24 410 -21Compound (6) 180 -32 380 -28______________________________________ TABLE II______________________________________Hypolipidemizing activity in mouse of the amidederivatives of 2-(p-aminobenzyl)-butyric acid andesters thereof: Total cholesterol TriglyceridesCompounds % mg % variation % mg % variation______________________________________Carrier 209 -- 147 --Bezafibrate 139 -33 100 -32Clofibrate 152 -27 115 -22Compound (2) 130 -38 60 -59Compound (3) 140 -33 64 -56Compound (4) 129 -38 90 -39Compound (5) 130 -38 80 -45Compound (6) 130 -38 64 -56______________________________________ TOXICITY DL 50 was evaluated after administration of the compounds (2), (3), (4), (5) and (6) alone in male albine Swiss mice weighing 27±3 g, using the oral route. The animals were held under observation by checking the mortality and pain signs, if any, for 15 days. The DL 50 values (mg/kg) are referred in table III. TABLE III______________________________________Acute toxicity in mouse of the amide derivativesof 2-(p-aminobenzyl)-butyric acid and esters thereof:compounds (2), (3), (4), (5) and (6).Compounds DL.sub.50 (mg/kg)/os______________________________________(2) >2000(3) >1700(4) >2000(5) >2000(6) >2000Clofibrate 1280.sup.x______________________________________ .sup.x Value as reported in literature: G. Metz et al, Arzneimittel Forschung, 27: 1173; 1977. The data referred in tables I, II show the pharmacotherapeutic effect of the amide derivatives of 2-(p-aminobenzyl)-butyric acid and esters thereof, which are the object of the present invention. The compounds (2), (3), (4), (5) and (6) show an interesting ability to decrease the hematic levels of cholesterol and triglycerides within the tested dosages and with respect to the control products. The low toxicity (table III) of said compounds gives them a high therapeutic index. Indeed the acute toxicity values are by several factors higher than the values used for reaching pharmaceutically active dosages. At the dosages and with the methods used and specified in the above tests, the administration to healthy animals has not brought about mortality at a long or short-term, nor evidence of toxic effects. The results referred in tables I, II and III document the therapeutic interest of a pharmaceutical composition according to the invention. The patients in need of a hypolipidemizing and hypocholesterolemizing pharmaceutical treatment will be orally administered with a pharmaceutical composition comprising an effective amount of a compound of formula (1). The dosage of this compound will generally be comprised between about 200 and about 600 mg/kg body weight/day, although larger and smaller dosages can be administered by having regard to the age, weight and general conditions of the patient. The compounds according to the invention can be administered in the form of tablets, capsules, solutions, suspensions, together with pharmaceutically compatible, non-toxic carriers and excipients.

Amide derivatives of 2-(p-aminobenzyl)-butyric acid and esters thereof having a hypolipidemizing and hypocholesterolemizing pharmaceutical activity and their preparation are described. Included are compounds of the formula ##STR1## wherein R and R' together represent the group ##STR2## or the group ##STR3## and R" is hydrogen or a 1 to 6 carbon alkyl group.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a hammer drill including a clockwise and counterclockwise driven tool spindle, a drive pinion operatively connectable with the tool spindle for transmitting a torque thereto, a separate control handle for selecting one of drill functions including a pure drilling operation, a pure percussion operation, and a drilling or rotary and percussion operation, and a switching device adjustable in accordance with the position of the control handle. [0003] 2. Description of the Prior Art [0004] Hammer drills of the type described above are very operator-friendly because switching between all three drill functions with the same control handle is possible. Moreover, the control handle can be easily arranged in such a way that switching of the drill functions takes place at an easily accessible and well visible location. [0005] German Publication DE-195 45 260 discloses a hammer drill in which switching between a pure drilling operation, a rotary-percussion operation, and a pure percussion operation is effected with a single rotary switch. The rotary switch is connected with a rotatable body for joint rotation therewith. The rotatable body displaces a shifting bushing arranged on an intermediate shaft and shifting sleeve arranged on the tool spindle. The percussion mechanism of the hammer drill is actuated and deactuated dependent on the position of the shifting bushing. Simultaneously, dependent on the position of the shifting sleeve, the tool spindle rotates or is secured to the housing without a possibility of rotation. Further, the hammer drill has an actuation member which is provided on an on-off switch and which serves for switching between clockwise and counterclockwise rotation of the tool spindle by changing the polarity of the drive motor. [0006] The drawback of the known hammer drill consists in that a separate switch should be provided for effecting the clockwise and counterclockwise operations and which is poorly visible. Further, in such a hammer drill, because of two rotational directions of the motor, the fan likewise should be adapted for operation in opposite directions. This reduces the power of the fan and thereby its cooling effect. [0007] Accordingly, an object of the present invention is to provide a hammer drill in which the drawbacks of the known hammer drill are eliminated and the operating convenience is increased. SUMMARY OF THE INVENTION [0008] This and other objects of the present invention, which will become apparent hereinafter are achieved by providing a hammer drill in which the switching device is shiftable by the control handle in a clockwise rotation position for effecting a pure drilling operation in a clockwise direction and in a counterclockwise rotation position for effecting a pure drilling operation in a counterclockwise direction. [0009] With such a switching device, the switching between clockwise and counterclockwise operations can be effected with the same control handle that is used for selection of an operational function, which insures a better handling of the hammer drill. Further, the switching between the clockwise and counterclockwise operations is clearly visible and, generally, the operating convenience of the hammer drill is increased. [0010] Advantageously, the switching device includes clockwise gear means and counterclockwise means for alternating forming a clockwise rotational connection and a counterclockwise rotational connection between the tool spindle and the drive pinion in the pure drilling operation. Such gear drive means for switching of a rotational direction can be particularly easy, in comparison with the switching of the rotational direction by changing the polarity of the drive motor, integrated in the switching device for performing an additional switching function. In addition, the switching of the rotational direction with the same function—selecting control handle reduces manufacturing and operational costs, which further increases the operating convenience of the hammer drill. Moreover, with switching of the rotational direction with drive gear means, the motor and the fan, which is driven by the motor, can be operated only in one direction. Thereby, the shape of the fan, in particular, the shape of the fan lamellas can be optimized in order to achieve a better cooling efficiency. [0011] Advantageously, the switching device is brought by the control handle in an additional position in which both the clockwise and counterclockwise drive gear means occupies a position in which both the clockwise rotational connection and the counterclockwise rotational connection between the drive pinion and the tool spindle are broken, and the tool spindle is rotatable relative to a hammer drill housing. [0012] Thus, the control handle provides an adjusting or set-up position of the switching device in which the tool used in the hammer drill, e.g., a flat or spade-shaped chisel, can be rotated relative to the hammer drill into a desired position. [0013] According to a particular advantageous embodiment of the present invention, the clockwise drive gear means and the counterclockwise gear means include, respectively, a first drive gear and a second drive gear both driven by the drive pinion and both having, respectively, tooth surfaces arranged opposite each other. In this way, an easy switching between clockwise and counterclockwise rotational directions with the control handle can be effected. [0014] Advantageously, both first and second drive gears are permanently engaged with the drive pinion, and are alternatively rotatably connected with the tool spindle by the switching device. Thereby, an easy and disturbance-free switching between clockwise and counterclockwise rotational directions becomes possible. [0015] Advantageously, the switching device has a sleeve-shaped shifting member for rotatably connecting the tool spindle alternatively with one of the first and second drive gears. The shifting member is supported on the tool spindle for joint rotation therewith and for axial displacement relative thereto. Thereby, different positions of the switching device can be precisely and reliably retained. [0016] Advantageously, the switching device has a chiselling position in which a pure chiseling operation takes place in which the tool spindle is operatively connected to the hammer drill housing without a possibility of rotation relative thereto. Thereby, in a simple way, rotation of a chisel tool during a chiseling operation is prevented so that a precise chiseling operation can be carried out. [0017] Advantageously, the shifting member has engagement means engaging matching engagement means fixedly secured to the housing in the chiseling position of the switching device for preventing rotation of the tool spindle relative to the housing. Thereby, a particularly reliable securing of a chisel tool against rotation is achieved. [0018] It is particularly advantageous when the percussion mechanism is operated by an eccentric member driven by a drive member. Between the eccentric member and the drive member, there is provided separable coupling means operated by the switching device. Thereby, an easy actuation and deactivation of the percussion mechanism with the switching device is achieved. [0019] It is advantageous when the coupling means is formed as a coupling member permanently rotatably connected with one of the eccentric member and the drive member and rotatably disconnected from another of the eccentric member and the drive member in a switch-off position. Thereby, a disturbance-free actuation and deactuation of the percussion mechanism becomes possible. [0020] According to a particularly advantageous embodiment of the coupling means, the coupling member has a ramp profile that can be abutted by a movable bearing region of the switching device and which presses the coupling member back in an axial direction upon its rotation. Thereby, in a simple way, a separation movement of the coupling member for decoupling the eccentric member from the drive member is generated. [0021] Advantageously, the bearing region is formed on a shift plate supported in the hammer drill for linear displacement and which is displaceable by the control handle. This likewise insures a disturbance-free actuation and deactuation of the percussion mechanism. [0022] It is particularly advantageous when the shift plate is translationally connected with the sleeve-shaped shifting member of the switching device. Thereby, the shift plate is used for both switching the drive gears and for actuation and deactuation of the percussion mechanism, which noticeably simplifies the construction of the switching device and reduces the manufacturing costs. [0023] Further, the shift plate advantageously has a tooth profile connected, directly or indirectly, with a rotatable matching tool profile provided on the control handle. This insures a particularly precise shifting of the switching device and thereby a reliable switching between the different hammer drill functions. [0024] The novel features of the present invention, which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however, both as to its construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of preferred embodiment, when read with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0025] The drawings show: [0026] FIG. 1 a side view of a hammer drill according to the present invention; [0027] FIG. 2 a side, partially cross-sectional view of the eccentric drive of the hammer drill shown in FIG. 1 in its operational position in a set-up according to FIGS. 8 and 9 ; [0028] FIG. 3 a side, cross-sectional view of a switching device with the eccentric drive according to FIG. 2 in a set-up according to FIG. 5 ; [0029] FIG. 4 a side view of the shifting member of the switching device shown in FIG. 3 ; [0030] FIG. 5 a side, partially cross-sectional view of the switching device shown in FIG. 3 in a chiseling position; [0031] FIG. 6 . a side, partially cross-sectional view of the switching device shown in FIG. 3 in a position during shifting to the chiseling position; [0032] FIG. 7 . a side, partially cross-sectional view of the shift in device according to FIG. 3 in a position for effecting a drilling and percussion operational; [0033] FIG. 8 . a side, partially cross-sectional view of the switching device shown in FIG. 3 in a clockwise drilling position; and [0034] FIG. 9 a side, partially cross-sectional view of the switching device shown in FIG. 3 in a counterclockwise drilling position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0035] A hand-held, electrically driven hammer drill 2 according to the present invention, which is shown in FIG. 1 , has a housing 4 on which there is provided a control handle 6 in form of a rotary switch for setting up a desired drill function. The control handle 6 , together with an arrow symbol P, can be rotated relative to the housing 4 , to one of five switching positions which are shown with corresponding symbols on the housing 4 . Each switching position corresponds to a different drill function. There are provided chiseling position M, shifting-to-chiseling position MV, rotary-percussion position HB, clockwise drilling position RB, and counterclockwise drilling position LB. [0036] As shown in FIGS. 2 and 3 , the control handle 6 is used for actuation for a switching device 8 . The switching device 8 has a pinion 10 connected with the control handle 6 for joint rotation therewith and engaging a tooth profile 12 provided on a shift plate 14 . The shift plate 14 has an elongate opening 16 through which a guide member 18 , which is fixedly secured to the housing extends. In this way, the shift plate 14 is supported for a linear displacement relative to the housing 4 along a displacement path SR. [0037] At its rear, with respect to the operational direction AR of the hammer drill 2 , end, the shift plate 14 of the switching device 8 forms a bearing region 20 . At a corresponding positioning, the shift plate 14 lies on a ramp profile 22 that is formed on a displaceable coupling member 24 of an eccentric drive 26 . [0038] The eccentric drive 26 forms part of a percussion mechanism (not shown in detail) that applies blows to a tool spindle 28 in the operational direction AR upon its reciprocal movement during chiseling and rotary-percussion operations. The eccentric drive 26 includes an eccentric member 30 which, upon its rotation applies a reciprocating movement to a piston rod 32 in the operational direction AR. [0039] The coupling member 24 connects the eccentric member 30 with a drive member 34 for joint rotation therewith. The drive member 34 is permanently engaged with a pinion 38 of a motor 36 . As shown in FIG. 2 , the coupling member 24 engages, with a rib 40 , in a groove 42 that is formed in an axle 44 connected with the eccentric member 30 for joint rotation therewith. The drive member 34 is rotatably supported on the axle 44 . The torque transmission from the drive member 34 to the eccentric member 30 takes place only when the coupling member 24 is displaced along the groove 42 into a position in which an engagement member 46 of the coupling member 24 engages the matching engagement element 48 of the drive member 34 . The coupling member 24 is preloaded in the engagement position with a spring 50 . [0040] As further shown in FIG. 3 , the shift plate 14 has, at its front, with respect to the operational direction AR of the hammer drill 2 , end, an adjusting region 52 that is translationally connected with a sleeve-shaped shifting member 54 of the switching device 8 . E.g., the adjusting region 52 applies a sidewise pressure to the shifting member 54 when, simultaneously, a biasing force is applied to its opposite side. As shown in FIG. 3 , the adjusting region 52 is engageable with the shifting member 54 on both side of the operational direction AR. In this way, the shifting member 54 is displaceable on the tool spindle 28 by the adjusting region 52 of the shift plate 14 . [0041] The shifting member 54 is shown in detail in FIG. 4 . As shown in FIG. 4 , there are provided, on the circumferential surface of the shifting member 54 , engagement bays 56 . There are further provided, on one end surface of the shifting member 54 , engagement cams 58 and on the other, opposite end surface thereof, there is provided a crown formed of engagement elements 60 . [0042] As shown in FIGS. 2-3 , in a respective position of the shifting member 54 , the crown with engagement elements 60 can be brought into engagement with matching engagement elements 62 which are formed on an intermediate ring 64 secured to the housing 4 . The shifting member 54 is supported on the tool spindle 28 for joint rotation therewith. Thereby, the tool spindle 28 can be secured against rotation by the shifting member 54 when the engagement elements 60 to engage the matching engagement elements 62 that are provided on the intermediate ring 64 which is fixedly secured to the housing 4 . [0043] The shifting member 54 also connects the tool spindle 28 with first or second drive gear 66 , 68 which are connected by a drive pinion 70 with the motor pinion 38 . The first drive gear 66 has a tooth surface 67 that is arranged opposite a tooth surface 69 of the second drive gear 68 . The drive pinion 70 extends between the two surfaces 67 , 69 and permanently engages the first and second drive gears 66 , 68 , forming a clockwise drive with the first drive gear 66 and counterclockwise drive with the second drive gear 68 . [0044] FIGS. 5-9 show functioning of the switching device 8 in separate shift positions. [0045] FIG. 5 shows the switching device in a position corresponding to chiseling operation of the hammer drill 2 , which position is also shown in FIG. 3 . This position is obtained by switching the control handle 6 into a chiseling position M. The switching of the control handle 6 leads to rotation of the rotation of the pinion 10 which is engaged with a tooth profile 12 of the shift plate 14 . As a result of rotation of the pinion 10 , the shift plate 14 is displaced in the displacement direction SR until it reaches its outmost position in the operational direction AR. Upon its displacement, the shift plate 14 displaces, with its adjusting region 52 , the shifting member 54 in the operational direction AR, resulting in engagement of the elements 60 with the engagement elements 62 of the intermediate ring 64 . This results in connection of the tool spindle 28 with the housing 4 , so that the tool spindle 28 cannot rotate relative to the housing 4 . In this position of the spindle 28 , the drive gears 66 , 68 are rotationally decoupled from the shifting member 54 , and no rotational coupling exists between the drive pinion 70 and the tool spindle 28 with which a torque can be transmitted to the tool spindle 28 . [0046] Simultaneously, the displaceable coupling member 24 of the eccentric drive 26 is biased by the spring 50 into engagement with the drive member 34 in this position of switching device 8 . With the motor 36 being turned on, a torque is transmitted to the eccentric member 30 via the motor pinion 38 , drive member 34 , coupling member 24 , and the axle 44 , and the eccentric member 30 actuates the percussion mechanism that is (not shown). [0047] In this position, the hammer drill 2 has a pure chiseling function at which the tool spindle 28 performs only the percussion movement in the operational direction AR, without being rotated. [0048] Upon rotation of the control handle 6 into the shifting-to-chiseling position MV, the switching device 8 assumes a position shown in FIG. 6 . In this position of the switching device 8 , the shift plate 14 is displaced by the pinion 10 in a direction opposite the operational direction AR. Simultaneously, the shifting member 54 becomes disengaged from the intermediate ring 64 . In this position, the shifting member 54 is rotationally decoupled from the drive gears 66 , 68 , and no torque is transmitted to the tool spindle 28 . [0049] In this position, the hammer drill 2 has a shifting-to-chiseling function at which a chisel (not shown) is inserted into the tool spindle 28 that can be pivoted to any arbitrary position. Thereby, e.g., a flat or spade-shaped chisel can be so aligned with respect to the hammer drill 2 that the hammer drill 2 is conveniently held during operation. [0050] Upon rotation of the control handle 6 to the rotary-percussion position, the switching device 8 occupies a position shown in FIG. 7 . In this position of the switching device 8 , the shift plate 14 is displaced even further in the direction opposite the operational direction AR, and the shifting member 54 is displaced so far that the engagement cams 58 engage the matching engagement profile 72 of the first drive gear 66 . In this way, a clockwise rotational connection is formed between the motor pinion 38 and the tool spindle 28 via the drive pinion 70 , the first drive gear 66 , and the shifting member 54 , which insures a clockwise rotational movement of the tool spindle 28 . Simultaneously, the motor 36 also drives the percussion mechanism. [0051] In this position, the hammer drill 2 performs both drilling and percussion functions, so that both clockwise rotation and percussion movement in the operational direction AR are imparted to the tool spindle 28 . [0052] Upon rotation of the control handle 6 to the clockwise drilling position RB, the switching device 8 occupies a position shown in FIG. 8 . In this position of the switching device 8 , the clockwise rotational connection of the tool spindle 28 with the motor pinion 38 is retained, but the shift plate 14 is displaced so far in the direction opposite the operational direction AR that its bearing region 20 abuts the ramp profile 22 . During the rotation of the eccentric drive 26 , the coupling member 24 applies pressure to the bearing region 20 only through the ramp profile 22 and is displaced out of the engagement with the drive member 34 against the biasing force of the spring 50 . In this way, the eccentric member 30 becomes rotationally disengaged from the drive member 34 , and the percussion mechanism is deactivated. [0053] In this position of the switching device 8 , the hammer drill 2 has a clockwise drilling function at which the tool spindle 28 performs a simple clockwise rotation. [0054] Upon rotation of the control handle 6 to the counterclockwise rotation position LB, the switching device 8 occupies a position shown in FIG. 9 . In this position of the switching device 8 , the eccentric member 30 remains rotationally decoupled from the drive member 34 . The shifting member 54 is in its outmost position in the direction opposite the operational directional AR. In this position of the shifting member 54 , the engagement cams 58 are disengaged from the matching engagement profile 72 of the first drive gear 66 , and only the engagement bays 56 form an engagement connection with the matching engagement profile 74 of the second drive gear 68 . Thereby, only a counterclockwise rotational connection is formed between the motor pinion 38 and the tool spindle 28 via the drive pinion 70 , the second drive gear 68 , and the shifting member 54 , which results in the counterclockwise rotation of the tool spindle 28 . [0055] In this position of the switching device 8 , the hammer drill 2 has a counterclockwise drilling function at which the tool spindle simply performs a counterclockwise rotational movement. [0056] Though the present invention was shown and described with references to the preferred embodiment, such is merely illustrative of the present invention and is not to be construed as a limitation thereof and various modifications of the present invention will be apparent to those skilled in the art. It is therefore not intended that the present invention be limited to the disclosed embodiment or details thereof, and the present invention includes all variations and/or alternative embodiments within the spirit and scope of the present invention as defined by the appended claims.

A hammer drill ( 2 ) includes a clockwise and counterclockwise driven tool spindle ( 28 ), a drive pinion ( 70 ) operatively connectable with the tool spindle ( 28 ) for transmitting a torque thereto, a separate control handle ( 6 ) for selecting one of the hammer drill functions including a pure drilling operation, a pure percussion operation, and a rotary-percussion operation), and a switching device ( 8 ) which is adjustable in accordance with a position of the control handle ( 6 ) and which is shiftable by the control handle ( 6 ) in a clockwise rotation position for effecting a pure drilling operation in a clockwise direction and in a counterclockwise rotation position for effecting a pure drilling operation in a counterclockwise direction.

This is a continuation of application 08/270,971, filed Jul. 5, 1994, now abandoned. FIELD OF THE INVENTION The present invention deals with burst size optimization for any projectile-based system designed to defeat multiple targets presenting eminent threats. An optimum probability of defeating the threats is achieved by scheduling the number of rounds needed to kill each target. The invention utilizes logic steps and routines which are integrated with fire control computers, target acquisition radar and communication systems to enable assessment of eminent threats and assign responsive measures to defeat the threats. SUMMARY OF THE INVENTION The gun salvo scheduler is a computer based target information acquisition, threat assessment and appropriate response initiating system which maximizes a cumulative probability of kill against the target and schedules rounds accordingly. The salvo scheduler utilizes a closed looped routine to schedule rounds so that the predicted probability of kill is maximized. The routine, iteratively, compares the preferred threshold of probability of kill and adjusts it based on availability of rounds and limitations of response time. Specific advances, features and advantages of the present invention will become apparent upon examination of the following description and drawings dealing with several specific embodiments thereof. BRIEF DESCRIPTION OF THE DRAWINGS 1. FIG. 1 is a flow chart in which the routine assesses the population of the threat; the availability of rounds; the fire rate or time between rounds; the probability of killing the threat and determines the best solution, by determining the number of rounds to fire at each target. 2. FIG. 2 is a flow chart showing how the optimal burst routine fits in with the other functions in a fire control computer to detect, track, queue, schedule, and engage incoming targets 3. FIG. 3 is a block diagram showing the interaction of the salvo scheduler with other units and the communication thereof. 4. FIG. 4 is a depiction of how the salvo scheduler protects assets by attacking in-coming threats. DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention provides a computer integrated algorithm which maximizes the likelihood of surviving a missile/aircraft attack against a high value asset defended by a gun weapon system. Referring now to FIG. 1, a flow chart is shown in which algorithmic logic steps are set. Probability of kill (PK) and target count (TARG CNT) 10 initiates the target counter and subsequent logic steps and routines. Initially the target count is set at zero. This communicates with the Bullet and Target count logic step 12. The bullet count is set at zero, initially. Consecutive logic step 14 sets bullet count, first motion time and gun delay time. Further, logic step 14 sets first motion time equal to the sum of start fire, gun delay time and time between bullets. Logic step 16 compares and confirms if first motion time is greater than last motion time or target count. If the response to logic step 16 is affirmative, the routine advances to logic step 18 which decreases the desired PK hurdle by an established quantity. The target count is set to zero and when the probability of kill is equal to unity, the result is directed back into logic step 12. If the answer to logic step 16 is in the negative, the routine proceeds to logic step 24. Logic step 24 includes intercept range calculations; probability of kill for a single shot (SS) calculations as well as calculations for cumulative probability of kill. Consecutive logic step 26 inquires if the cumulative probability of kill is greater than the probability of hurdle or if the bullet count is greater than the maximum burst size allowable. If the answer to any of these is negative the logic routine reverts behind logic step 14. If the answer is positive the routine proceeds to logic step 28 to set the start fire time which is equal to first motion time. Subsequently, the routine advances to logic step 30 wherein the system checks if the target count is equal to the maximum targets observed. If the target count does not yield the maximum number of targets, the logic reverts back to logic step 12. On the other hand, if the target count yields the maximum number of threat targets, the routine advances to logic step 32 wherein the system returns the number of bullets to fire at each threat. Logic steps 10 through 32 discussed hereinabove, comprise the logical sequence and steps required to set up probability of kill and eminent threat target count. In subsequent discussions, as in FIG. 2, logic steps 10 through 32 will be referred to as "Routine A" 56. Referring now to logic steps of FIG. 2, the unique aspects of Routine A 56 are shown integrated with other logic as shown. More specifically, logic step 38 sets the target search. Consecutive logic step 40 interrogates if a target has been detected. If no target detection has been noted the routine is directed back to target search logic step 38. However, if a target has been detected the routine is directed to logic step 42 wherein a target track file is created. The routine proceeds to logic step 44 which determines whether the new target should be considered part of the current raid. If the new target is not part of the current raid, it is placed in a queue for future scheduling and is set under logic step 46. If a new target is considered part of the current raid the routine proceeds to logic step 52 to decide if a maximum burst size could be launched at each target. If a maximum burst size could not be launched at each target the system reverts to Routine A 56 (See FIG. 1) and accordingly, the burst size for each target is determined. In the alternate, if a maximum burst size could be launched at each target, the system proceeds to logic step 58 where the open fire time is determined. Consecutive logic step 60 determines the time to open fire. Upon confirming to open fire the routine proceeds to logic step 66 where fire is opened on the scheduled threat. If the time is not ripe to open fire the routine proceeds to logic step 68 which checks if new track files have been created. In the absence of new track files the routine reverts back to logic step 60 as shown. Further, it should be noted that logic step 60 is communicative with Routine A 56, such that the burst size for each target is determined simultaneously with the proposal to whether it is time to open fire. Logic step 66 advances to logic step 70 where the current raid is checked to be the last threat in the current raid. If the response is negative, the routine goes back to logic step 68. In the alternate, if the response is positive, the routine advances to logic step 72 where the existence of threats in the queue is checked. If there are threats in the queue, the routine advances to logic step 52. On the other hand, if there are no threats in the queue, the routine goes back to logic step 38 where a target search and consecutive logic are initiated. Referring now to FIG. 3, a communicative system comprising fire control computer 74, gun weapon system and salvo scheduler 76, target acquisition radar 78 and communication link 80 are shown. FIG. 4 shows the general and conceptual operation of the present invention. In-coming threats or missiles 84 and 84' are shown directed at assets 86. Gun system 88, fires rounds 92 and 92', using the salvo scheduler of the present invention to defeat the incoming threats. The description hereinabove relates to some of the most important features which set and determine, inter alia, the structural parameters of the present invention. The operations of the present invention, under a best mode scenario, are discussed hereinbelow. As disclosed in the logic flow chart of FIG. 1, (Routine A) one of the most important aspects of the present invention includes the ability to set and calculate the burst size directed to each threat thereby maximizing probability of eliminating all threats. Primarily, target acquisition radar 78 provides input to gun weapon system and salvo scheduler 76 that a threat target has been identified. With specific reference to FIGS. 2 and 3, target search in logic step 38 communicates with target acquisition radar 78 via communication link 80. Once the presence of a target is confirmed, a target track file is created under logic step 42. Further, the target is classified as either a part of the current raid or a non-current raid target under logic step 44. If the new target is not part of the current raid, the data is placed in queue for future scheduling under logic step 46. The routine proceeds to allocate a maximum burst size per target if the threat is identified as part of the current threat. This is executed under logic step 52. However, if the maximum burst size cannot be launched at each target, the logic flow advances to Routine A, logic step 56, to determine the burst size required to defeat each target. Further, gun weapon system and salvo scheduler 76 communicate with fire control computer 74 to determine the open fire time 58. Thence, the routine proceeds to logic step 60 to confirm if it is time to open fire. If the system's readiness to open fire is confirmed, fire is opened on the scheduled threat, under logic step 66. Further, for every threat being fired upon, the routine confirms if this is the last threat in the current raid under logic step 70. When the last of the current threats is confirmed, the routine proceeds to check if there are any threats in the queue under logic step 72. Continuous communications with target acquisition radar 78 provide information on both queued and current threat data. If the last of the current threats is dealt with, and there are no threats resident in the queue, the routine goes back to logic step 38 to search for new targets. Referring now to FIGS. 3 and 4, the overall system function is represented. Here, gun weapon system and salvo scheduler 76 is incorporated in gun system 88. Further, fire control computer 74 is also incorporated in gun system 88. Gun system 88 communicates with target acquisition radar 78 via communication link 80. In-coming threats 84 are detected by radar 78 and the information is communicated to salvo scheduler 76 in gun system 88. The salvo scheduler 76 goes through the iteration and logic steps disclosed in FIGS. 1 and 2 and discussed hereinabove. The salvo scheduler 76 of the present invention commands the fire control against the scheduled threat and rounds 92 are deployed to engage threats 84. More specifically, the salvo scheduler of the present invention prioritizes threats according to most eminent threat arrival. Thus, the gun system engages threats 84 first. A specific number (burst size) of rounds 92 are allocated and deployed to destroy the eminent threats 84. Further, gun system 88 switches over to in-coming threats 84' (refer to phantom lines) to engage these threats on a second priority or temporally sequenced basis. Thus, the salvo scheduler determines the open fire time and allocates the optimum number of rounds to defeat a threat. More specifically, the present invention enables the optimization of probability of kill based on threat characteristics. Accordingly, the protection of assets 86 is significantly enhanced by the unique features and functions resident in the present invention. While a preferred embodiment of the gun salvo scheduler has been shown and described, it will be appreciated that various changes and modifications may be made therein without departing from the spirit of the invention as defined by the scope of the appended claims.

This disclosure relates to a computer based eminent and dormant threat acquisition, assessment and defense system. Threats are classified as to eminence and incidence of detection and rounds are optimally scheduled to defeat the threats based on inventory of defensive rounds, response time and probability of kill.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to United States Provisional Application Serial No. 60/178,421, filed Jan. 27, 2000, entitled “Apparatus for Regulating Power to an Integrated Circuit.” TECHNICAL FIELD [0002] The present invention generally relates to microelectronic devices. More particularly, the present invention relates to microelectronic devices suitable for regulating power. BACKGROUND OF THE INVENTION [0003] Regulators are often employed to provide a desired, regulated power to microelectronic devices such as microprocessors. For example, switching regulators such as buck regulators are often used to step down a voltage (e.g., from about 3.3 volts) and provide suitable power to a microprocessor (e.g., about 10-30 amps and about 2-3 volts). [0004] To increase speed and reduce costs associated with microprocessors, microprocessor gate counts and integration generally increase, while the size of the microprocessor per gate generally decreases. As gate counts, speed, and integration of microprocessors increase, supplying requisite power to microprocessors becomes increasingly problematic. For example, a current required to drive the processors generally increases as the number of processor gates increases. Moreover, as the gate count increases per surface area of a processor, the operating voltage of the processor must typically decrease to, among other reasons, reduce overall power consumption of the processor. Furthermore, as the microprocessor speed increases, the microprocessors demand the higher current at faster speeds. [0005] Although buck regulators are generally suitable for controlling power to some microprocessors, such regulators are not well suited to supply relatively high current (e.g., greater than about 30 amps) at relatively high speed (e.g., greater than about 500 MHz.). One reason that buck regulators have difficulty supplying high current at high speed to the microprocessor is that the current supplied from the regulator to the processor has to travel a conductive path that generally includes a portion of a printed circuit board that couples the processor to the regulator. The relatively long conductive path between the processor and the regulator slows a speed at which the regulator is able to supply current to the processor. In addition, as microprocessor speed and current demands increase, the buck controller simply cannot provide the desired amount of current at the desired rate. [0006] Yet another problem with buck regulators is that they are generally configured to supply power to within about ±5% of a desired value. While this range may be acceptable for processors running at relatively low currents, this range becomes decreasingly acceptable as the current requirements of microprocessors increase. Thus, as microprocessor gate counts and clock speeds increase, improved methods and apparatus for supplying high current at high speed and low voltage are desired. Furthermore, methods and apparatus for supplying the relatively high current within a relatively tight tolerance is desired. SUMMARY OF THE INVENTION [0007] The present invention provides improved apparatus and techniques for providing regulated power to a microelectronic device. More particularly, the invention provides improved devices and methods suitable for supplying electronic devices with relatively high, regulated current at relatively high speed. [0008] The way in which the present invention addresses the deficiencies of now-known regulators and power supply systems is discussed in greater detail below. However, in general, the present invention provides an array of power regulators that provides power to a single microelectronic device. [0009] In accordance with one exemplary embodiment of the present invention, an array of regulators is configured to provide power to a microprocessor. In accordance with one aspect of this embodiment, the array is formed as an integrated circuit on a semiconductor substrate. In accordance with a further aspect of this embodiment, the circuit is coupled to the microprocessor through a relatively short conductive path (e.g., by coupling the circuit to the device via bump interconnects). In accordance with yet a further aspect of this embodiment, the array circuit is formed on a silicon germanium (SiGe) substrate to facilitate faster current supply to the device. In accordance with a further exemplary embodiment of the present invention, a tiered power regulation system is configured to provide power to a microelectronic device. The tiered system includes at least two levels of power regulation. In accordance with an exemplary aspect of this embodiment, a first level of power regulation includes a switching regulator and a second level of regulation includes a linear regulator. In accordance with a further aspect of this embodiment, the second level of regulation includes an array of linear regulators. BRIEF DESCRIPTION OF THE DRAWINGS [0010] [0010]FIG. 1 illustrates a power regulation system in accordance with an exemplary embodiment of the present invention; [0011] [0011]FIG. 2 illustrates a power regulation system in accordance with alternative embodiment of the present invention; and [0012] [0012]FIG. 3 schematically illustrates a portion of a regulator array in accordance with an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS [0013] The present invention generally relates to microelectronic power regulators. More particularly, the invention relates to regulators suitable for providing high current, high speed power to microelectronic devices and to electronic systems including the regulators. Although the present invention may be used to provide power to a variety of microelectronic devices, the invention is conveniently described below in connection with providing power to microprocessors. [0014] An exemplary power supply system 100 in accordance with the present invention is schematically illustrated in FIG. 1. As illustrated, system 100 includes an intermediate regulator 110 , a regulator array 120 , including regulators 120 ( a )- 120 ( n ), and a microprocessor 130 . System 100 may also suitably include a power converter 140 and one or more discrete electronic components, collectively represented as components 150 . [0015] In general, system 100 is configured to provide relatively high current (e.g., 30 to more than 100 amps) at relatively low voltage (e.g., down to about 1 volt or less) with a relatively short response time. As discussed in greater detail below, in accordance with the present invention, system 100 provides the high current power to microprocessor 130 by distributing the power regulating duty to a plurality of regulators (e.g. regulator 110 and/or regulators 120 ( a )- 120 ( n )) [0016] Converter 140 of system 100 is generally configured to convert alternating current (AC) power obtained from a typical AC power outlet to direct current (DC) power to, for example, provide suitable DC power for a motherboard of a computer. For example, in accordance with one exemplary embodiment of the present invention, converter 140 is configured to convert 110 volt AC power to about 3.3 volts to about 15 volts DC power at about 1 amp to about 20 amps. In accordance with one aspect of this embodiment, converter 140 includes multiple DC power outputs—e.g., about 12 volts at about 1 amp, about 5 volts at about 5 amps, at about 3.3 volts at about 30 amps to supply the power to, for example, various types of microelectronic devices which may be coupled to the motherboard. In accordance with alternative embodiments of the present invention, converter 140 may include any number of DC power outputs, and the amount of power associated with each output may vary in accordance with a type of device coupled to the output of converter 140 . [0017] Intermediate regulator 110 is a DC-to-DC converter, which is designed to convert output from converter 140 to higher current, lower voltage power. In accordance with one exemplary embodiment of the present invention, regulator 110 receives power (e.g. 3.3 volts at 30 amps) from converter 140 and converts the power to about 1.15 volts at about 100 amps. Regulator 110 may be a linear regulator, a switching regulator, or any other suitable type of power controller; however, in accordance with one exemplary embodiment of the present invention, regulator 110 comprises a switching regulator such as a buck regulator. [0018] System 100 may also optionally include discrete components 150 to facilitate rapid response power transfer from regulator 110 to array 120 . In particular, components 150 may include capacitors to store an appropriate charge and discharge the energy as array 120 calls for power from regulator 110 . [0019] Regulator 120 is generally configured to provide high current (e.g., up to 100 amps or more) power at a relatively low response time (e.g., at speeds of 500 MHz and above) to microprocessor 130 . In accordance with an exemplary embodiment of the present invention, array 120 includes one or more power regulators (e.g., regulators 120 ( a )- 120 ( n )) configured to transform power received from regulator 110 and/or components 150 and convert the power into higher current, lower voltage power suitable for microprocessor 130 . [0020] Array 120 may include any number of regulators, which may be configured and coupled to processor 130 in a variety of ways. For example, array 120 may include a number (n) of substantially identical regulators, wherein each regulator is configured to provide processor 130 with 1/n the operation power of processor 130 . However, in accordance with alternate embodiments of the invention, array 120 may be configured with regulators of various sizes that are configured to provide power to various portions of processor 130 . For example, array 120 may include relatively high current regulators to provide power to input/output buffers and relatively low current regulators to supply power to logic units of the microprocessor. [0021] [0021]FIG. 2 illustrates a power supply system 200 in accordance with an alternative embodiment of the invention. Similar to system 100 , system 200 generally includes an intermediate regulator 210 , a regulator array 220 , including regulators 220 ( a )- 220 ( n ), a microprocessor 230 , and optionally a power converter 240 and components 250 . [0022] System 200 is configured such that a portion of power supplied to microprocessor 230 may be derived from regulator 210 . For example, in accordance with one aspect of this embodiment, regulator 210 supplies power to input/output contacts of microprocessor 230 and/or a floating point contact of microprocessor 230 . However, the invention is not so limited; system 200 may suitably be configured such that regulator 110 provides power to any portion of microprocessor 230 . [0023] [0023]FIG. 3 is a schematic illustration of an array 300 , showing regulators 310 , 320 , 330 , and 340 coupled to a common voltage reference 350 in accordance with an exemplary embodiment of the present invention. In accordance with the embodiment illustrated in FIG. 3, each regulator 310 - 340 is configured to supply substantially the same power (at the reference voltage) to a microprocessor—e.g., microprocessor 130 . [0024] Regulators 310 - 340 may include switching regulators, linear regulators, combinations thereof, or other suitable devices for controlling power. In accordance with one exemplary embodiment of the present invention, regulators 310 - 340 are linear regulators and each regulator 310 - 340 suitably includes a transistor (e.g., bipolar transistors 312 , 322 , 332 , and 342 ), an error amplifier (e.g., error amplifier 314 , 324 , 334 , and 344 ), and a voltage source (e.g., sources 316 , 326 , 336 , and 346 ). [0025] As noted above, regulators 310 - 340 are generally configured to provide output power to processor 130 at a voltage substantially equivalent to voltage reference 350 . However, regulators 310 - 340 may suitably be trimmed such that the output voltage can be set to about ±1% of the reference voltage. In accordance with alternative embodiments of the present invention, array 300 may include multiple voltage references at various voltages, with one or more regulators tied to each reference. Use of multiple voltage references allows for power regulation at the various voltage levels to various portions of microprocessor 130 . [0026] In accordance with one exemplary embodiment of the invention, all regulators (e.g., regulators 310 , 320 , 330 , and 340 ) are suitably coupled together in parallel such that, in addition to each regulator being tied to a common reference voltage, each regulator array 300 is tied to a common collector structure. The parallel coupling of regulators within an array allows for a total current output of array 300 which is equal to the sum of current outputs from each regulator within array 300 . Thus, time delays associated with larger regulators are mitigated because smaller regulators within an array are used to provide current to a portion or portions of microprocessor 130 . In other words, microprocessor 130 does not depend on a single, large regulator to supply requisite current. [0027] A conductive path between array 120 and microprocessor 130 , or a portion thereof, is preferably relatively short to reduce the effects of parasitic inductance between an array (e.g., array 120 ) and microprocessor 130 . Providing a relatively short conductive path between array 120 and microprocessor 130 is additionally advantageous because parasitic inductance between array 120 and processor 130 is generally reduced as the distance between the components is reduced. One technique for providing a relatively short conductive path between array 120 and microprocessor 130 in accordance with the present invention is to couple array 120 to processor 130 using conductive bumps such as C 4 (Controlled Collapse Chip Connection) bumps. In accordance with various aspects of this embodiment, array 120 may be coupled directly to microprocessor 130 , or array 120 may suitably be coupled to a package containing microprocessor 130 . [0028] To facilitate fast power delivery from regulators 120 ( a )- 120 ( n ) of array 120 to processor 130 , regulators 120 ( a )- 120 ( n ) are formed on a semiconductor substrate having relatively high electron mobility such as silicon germanium (SiGe), Gallium Arsenide (GaAs), or the like. Forming regulators on SiGe or similar substrates that have relatively high electron mobility allows relatively quick power transfer (e.g., on the order of GHz speed) between regulator 120 and microprocessor 130 . In addition, semiconductive substrates such as SiGe exhibit a relatively high current density, compared to conventional semiconductor materials, which allows for formation of more transistors per surface area of SiGe compared to substrates having lower current density such as silicon. [0029] In accordance with an alternative embodiment of the present invention, a regulator array and microprocessor 130 are formed on a single semiconductive substrate formed of, for example, SiGe, or other suitable semiconductive materials. Integrating an array and a microprocessor on a single substrate allows for even faster power supply from the array to the microprocessor. The integral array may provide power to all or a portion of the microprocessor and may be in addition to or in lieu of an array, such as array 120 illustrated in FIG. 1. [0030] Although the present invention is set forth herein in the context of the appended drawing figures, it should be appreciated that the invention is not limited to the specific form shown. For example, while the invention is conveniently described above in connection with providing power to a discrete microprocessor, the present invention may suitably be used provide power to a plurality of microelectronic devices. Various other modifications, variations, and enhancements in the design and arrangement of the method and apparatus set forth herein may be made without departing from the spirit and scope of the present invention as set forth in the appended claims.

A regulator system for supplying power to a microelectronic device is disclosed. The system includes an array of a plurality of regulators, where each regulator provides a portion of power required to operate the device. The system may further include an intermediate power regulator that supplies power to the array of regulators.

BACKGROUND [0001] Quantum cascade lasers provide a tunable mid-infrared (MIR) light source that can be used for spectroscopic measurements and images. Many chemical components of interest have molecular vibrations that are excited in the MIR region of the optical spectrum, which spans wavelengths between 5 to 25 microns. Hence, measuring the absorption of MIR light at various locations on a sample can provide useful information about the chemistry of the sample as a function of position on the sample. [0002] One class of imaging spectrometers measures the light directly reflected from the sample as a function of position on the sample and wavelength of the illuminating MIR light. The amount of light that is reflected depends on both the chemical and physical attributes of the sample. Hence, comparing spectra generated with direct reflection to absorption with known chemical absorption spectra that are available in libraries presents significant challengers. SUMMARY [0003] The present invention includes a scanner and an attenuated total reflection (ATR) objective for use in such scanners. The scanner includes a light source that generates a first collimated light beam and an ATR objective. The ATR objective includes first and second optical elements and an input port. The first optical element includes a planar face, characterized by a critical angle. The input port is adapted to receive a first input collimated light beam characterized by a central ray, the input port being characterized by a pivot point through which the central ray passes and an orientation direction that passes through the pivot point. The second optical element focuses a portion of the first input collimated light beam to a point on the planar surface such that substantially all of that portion is reflected by the planar face and no portion of the input beam strikes the planar face at an angle greater than the critical angle. The second optical element generates a first output collimated light beam from light reflected from the planar face. The first output optical beam is characterized by a central ray that is coincident with the central ray of the first input collimated light beam. A first detector measures an intensity of light in the first output collimated light beam. The scanner also includes a light beam converter that receives the first collimated light beam and generates the first input collimated light beam therefrom in response to an orientation signal that determines an orientation between the orientation direction and the central ray of the input collimated light beam. [0004] In one aspect of the invention, the scanner includes a controller that generates the orientation signal and causes the light beam converter to sequence through a predetermined set of different orientations between the orientation direction and the central ray of the input collimated light beam. [0005] In one aspect of the invention, the light beam converter includes first and second parabolic reflectors and a beam deflector. The beam deflector receives the first collimated light beam and deflects that light beam to a point on the first parabolic reflector, the point being determined by the orientation signal. The second parabolic reflector is positioned to receive light reflected from the first parabolic reflector and collimate the received light to generate the first input collimated light beam. [0006] In another aspect of the invention, the scanner also includes a reflective objective having an input port, an optical element, and a third parabolic reflector. The input port is configured to receive a second input collimated light beam characterized by a central ray. The optical element focuses the second input collimated light beam to a spot at a predetermined point. The optical element receives light reflected from the predetermined point and forms a second output collimated beam therefrom. The second output collimated beam is characterized by a central ray that is coincident with the central ray of the second input collimated light beam. The third parabolic mirror intercepts light reflected from the first parabolic mirror and generates the second input collimated light beam therefrom when the third parabolic minor is in a first position. The third parabolic mirror does not intercept light from the first parabolic mirror when the third parabolic mirror is in a second position. The position of the parabolic material is determined by an actuator that is responsive to a mode signal. [0007] In another aspect of the invention, the scanner also includes an actuator that moves the reflective objective in relationship to a specimen stage such that the spot moves in a line parallel to the stage. The controller causes the beam deflector to move the point on the first parabolic reflector such that the spot moves in a direction orthogonal to the line. [0008] In another aspect of the invention, the scanner includes a second detector that measures an intensity of light in the first collimated light beam. [0009] An ATR objective according to the present invention includes first and second optical elements, an input port and a mask. The first optical element includes a planar face. The input port is adapted to receive a collimated beam of light characterized by a central ray, the input port being characterized by a pivot point through which the central ray passes. The mask divides the collimated beam of light into first and second portions, the mask preventing light in the first portion from reaching the planar face. The second optical element focuses the second portion on a point on the planar face such that substantially all of the second portion is reflected from the planar face, the second optical element collecting light reflected from the planar face and collimating the collected light into an output beam that leaves the input port in a collimated beam having a central ray coincident with the central ray of the input collimated light beam. [0010] In one aspect of the invention, the mask absorbs light in the first portion. [0011] In another aspect of the invention, the first optical element is transparent to light having a wavelength between 3 and 20 microns. In another aspect, the first optical element is transparent to light having a wavelength between 5 and 12.5 microns. [0012] In another aspect of the invention, the first optical element includes a crystalline material, and the planar face is a facet of a crystal of the crystalline material. [0013] In another aspect of the invention, the first optical element includes a glass that is transparent to light having a wavelength between 3 and 20 microns. In another aspect, the first optical element is a glass that is transparent to light having a wavelength between 5 and 12.5 microns. [0014] In another aspect of the invention, the second optical element is a refractive element. In another aspect, the second optical element is a reflective element. [0015] In another aspect of the invention, the input port is characterized by a direction that passes through the pivot point and wherein the point on the planar face depends on an orientation of the central ray of the collimated beam relative to the direction. BRIEF DESCRIPTION OF THE DRAWINGS [0016] FIG. 1 illustrates one embodiment of a direct MIR imaging system. [0017] FIG. 2 is a cross-sectional view of an interface crystal that can facilitate the measurement of the absorption of light by a sample in the reflective geometry mode. [0018] FIGS. 3A-3D illustrate a scanning ATR objective for a MIR microscope. [0019] FIG. 4 illustrates an ATR objective that utilizes a reflective optical element to image the input collimated light beam. [0020] FIG. 5 illustrates the collimated beam motion used to scan the focus point over the reflective face of an ATR objective. [0021] FIG. 7 illustrates a parabolic mirror that utilizes two moving mirrors to cause a collimated light beam to scan in two dimensions. [0022] FIG. 8 illustrates one embodiment of a dual mode MIR spectrometer according to the present invention. [0023] FIG. 9 illustrates a scanning reflective objective that can be used in the spectrometer shown in FIG. 8 . DETAILED DESCRIPTION [0024] The manner in which the present invention provides its advantages can be more easily understood with reference to FIG. 1 which illustrates one embodiment of a direct MIR imaging system. Imaging system 10 includes a quantum cascade laser 11 that generates a collimated light beam 18 having a narrow band of wavelengths in the MIR. In one aspect of the invention, quantum cascade laser 11 is a quantum cascade laser having a tunable wavelength that is under the control of controller 19 . The intensity of light from quantum cascade laser 11 is controlled by a variable attenuator 11 a that is also under the control of controller 19 . Collimated light beam 18 is split into two beams by a partially reflecting mirror 12 . Light beam 18 a is directed to a lens 15 that focuses that beam onto a specimen 16 that is mounted on xyz-stage 17 that can position specimen 16 relative to the focal point of lens 15 . Light that is reflected back from specimen 16 is collimated into a second beam that has a diameter determined by the aperture of lens 15 and returns to partially reflecting mirror 12 along the same path as light beam 18 a. While the first and second beams are shown as having the same cross-section in FIG. 1 , it is to be understood that the second beam could have a different cross-section than the first beam. A portion of the second beam is transmitted through partially reflecting mirror 12 and impinges on a first light detector 13 as shown at 18 b. Light detector 13 generates a signal related to the intensity of light in beam 18 b. Controller 19 computes an image as a function of position on specimen 16 by moving specimen 16 relative to the focal point of lens 15 using xyz-stage 17 . [0025] Controller 19 also monitors the beam intensity of the light in collimated light beam 18 using a second light detector 14 that receives a portion of the light generated by quantum cascade laser 11 through partially reflecting mirror 12 . Quantum cascade laser 11 is typically a pulsed source. The intensity of light from pulse to pulse can vary significantly, and hence, the pixels of the image are corrected for the variation in intensity by dividing the intensity measured by light detector 13 by the intensity measured by light detector 14 . In addition, since the light intensity from quantum cascade laser 11 is zero between pulses, controller 19 only sums the ratio of intensities from light detectors 13 and 14 during those times at which the output of light detector 14 is greater than some predetermined threshold. This aspect of the present invention improves the signal-to-noise ratio of the resultant image, since measurements between pulses contribute only noise, which is removed by not using measurements between pulses. [0026] Ideally, the input wavelength could be varied over an appropriate range of wavelengths and the light absorbed by the sample determined from the reflected light signal. That absorption spectrum could then be compared to standard absorption spectra from a library to provide information about the chemical composition of the sample at the point being illuminated. The difference in light intensity between the input beam that strikes the specimen and the light that is reflected from the specimen depends on the light that is absorbed by the specimen. Unfortunately, part of the light striking the sample is scattered. A significant fraction of the scattered light does not reach light detector 13 . The scattered light depends on the surface properties of the specimen. For example, a specimen having crystals embedded in its surface will specularly reflect the incoming light in a direction that depends on the angles of the crystal facets with respect to the incoming light. To compare the light losses as a function of wavelength with standard libraries, the contribution of the scattered light must be known or an arrangement in which the scattered light intensity is minimal must be used. [0027] One type of reflection spectroscopy that does not suffer from the problems associated with scattered light is referred to as ATR spectroscopy. ATR functions can be more easily understood with reference to FIG. 2 , which is a cross-sectional view of an interface crystal that can facilitate the measurement of the absorption of light by a sample in the reflective geometry mode. Crystal 21 has a high index of refraction. Light beam 26 enters crystal 21 thorough port 22 and strikes facet 23 at an angle that is greater than the critical angle. The light beam is totally reflected from facet 23 and exits the crystal through port 24 . At the point at which the light beam is reflected from facet 23 , the electric field associated with the light beam extends outside the crystal as shown at 25 . If the medium under facet 23 absorbs light at the wavelength of light beam 26 , the evanescent field will interact with the medium and energy will be transferred from the light beam to the medium. In this case, the energy in the beam leaving crystal 21 will be reduced. The difference in intensity between the input and output beams as a function of wavelength is a spectrum that matches a high-quality transmission spectrum and can easily be used for matching conventional spectra for various chemical compounds. [0028] While an interface crystal of the type discussed above is useful in measuring a MIR spectrum of a point on a sample, it presents challenges if an image of an area on the specimen is needed, particularly if the surface of the specimen is not smooth. To form an image, the interface must be moved relative to the specimen. To prevent the interface crystal from damaging the specimen, the specimen must be moved vertically to allow the crystal to be located at the next point of interest. The time for such point to point measurements makes a combination imaging and spectrometer instrument impractical unless very long times are available to generate a spectrum at each point on a specimen in high resolution. [0029] The present invention reduces the scanning time for ATR measurements by utilizing an ATR objective and a scanning MIR beam that allows small areas on the sample to be measured in ATR mode without moving the ATR objective of the specimen stage. Refer now to FIGS. 3A-3D , which illustrate a scanning ATR objective for a MIR microscope. Refer first to FIGS. 3A and 3B . FIG. 3A is a cross-sectional view through an ATR objective 30 , and FIG. 3B is a top view of ATR objective 30 as “seen” by a collimated light beam 39 entering ATR objective 30 at a non-normal angle to the top surface of ATR objective 30 . ATR objective 30 includes a crystal 32 having a high index of refraction for light in the MIR. Crystal 32 has a facet 34 that is parallel to the plane of specimen 16 . ATR objective 30 includes an optical component 31 which focuses the collimated light onto facet 34 . A beam blocker 33 prevents light from the center of collimated light beam 39 from striking facet 34 at an angle less than the critical angle, and hence, entering specimen 16 . The light reflected from facet 34 is collimated by optical component 31 and leaves ATR objective 30 along the same beam path as collimated light beam 39 . When light reflects from facet 34 , the evanescent field extends into the specimen. The energy absorbed by specimen 16 reduces the intensity of the light reflected from facet 34 . [0030] The details of the optical system that directs light into ATR objective 30 will be discussed in more detail below. For the purposes of the present discussion, it is sufficient to note that the position of spot 38 a is determined by the angles at which the collimated light beam 39 enters port 35 . The direction of collimated light beam 39 relative to ATR objective 30 can be specified by the two angles shown at 36 and 37 . Consider the XYZ coordinate system shown in the figure. Angle 36 is the angle between the normal to port 35 and the direction of collimated light beam 39 . Angle 37 is the angle between the x-axis and the projection of the direction of collimated light beam 39 on the xy plane. By changing these two angles, the point at which the light beam is focused on facet 34 can be varied. [0031] Refer now to FIGS. 3C-3D , which illustrate ATR objective 30 for a different input direction for collimated light beam 39 . FIG. 3C is the same cross-sectional view of ATR objective 30 shown in FIG. 3A , and FIG. 3D is the same top view of ATR objective 30 as shown in FIG. 3B . In this case, the direction of collimated light beam 39 has changed such that angle 37 is 180 degrees larger than angle 37 shown in FIG. 3B . The point, 38 b, at which the collimated light is focused on facet 34 has now moved as shown in FIG. 3C . [0032] An ATR objective according to the present invention is defined to be an optical subsystem having an optical element with a reflection face that internally reflects an input collimated light beam from the reflection face. The reflection face is parallel to the plane of the surface of a specimen being imaged. The collimated input beam is focused to a point on the reflection face at a location that is determined by the angular orientation of the collimated input beam relative to the orientation direction that characterizes an input port to the ATR objective. By changing the angular orientation of the input collimated light beam while maintaining the central ray of the input collimated light beam such that the central ray passes through a pivot point associated with the ATR objective, the point on the reflection face at which the light is focused is changed. In addition, the ATR objective also includes a mask that prevents light from the input beam from striking the reflection face at an angle less than the critical angle for the material from which the optical element is constructed, and thus prevents light from the input beam from directly entering the specimen. Finally, the optical subsystem collects light reflected from the reflection face, collimates that reflected light, and causes that collimated light to exit the ATR objective on a path that is coincident with the path at which the input collimated light beam entered the ATR objective. [0033] The output optical beam is collimated; however, the central portion of that beam is devoid of light, since the light that would have filled that portion of the output optical beam was removed by the mask. To increase the signal-to-noise in the detector that measures the intensity of light in the output optical beam, the detector can be configured as an annular detector to match the cross-section of the output optical beam with a central region that is insensitive to light. [0034] The optical element must be transparent to the MIR light. In one aspect of the invention, the optical element is transparent to light from 3 to 20 microns. In another aspect, the optical element is transparent to light between 5 and 12.5 microns. The later range is sufficient for many chemical identification applications while reducing the cost of the optical element. [0035] In addition, a material with a large index of refraction is preferred to minimize the amount of light that must be blocked to prevent the focused light beam from directly passing into the specimen. in one aspect of the present invention, the preferred optical element is a crystal of a material that is transparent to light in the desired scanning range and which has a planar facet that can be utilized as the face. However, a crystalline material for the optical element is not required. For example, a glass that was transparent to the MIR light could be utilized. In one aspect of the invention, the crystal is chosen from the group consisting of ZnS2, Diamond, ZnS, Ge, Thallium bromide, and Si. Chalcogenide glasses which are transparent to light over a broad range of infrared wavelengths are available commercially. [0036] The embodiment of an ATR objective shown in FIGS. 3A-3D utilizes a refractive optical component 31 to perform the imaging of the input collimated light beam onto the crystal facet. However, a reflective optical element could also be utilized. Refer now to FIG. 4 , which illustrates an ATR objective that utilizes a reflective optical element to image the input collimated light beam. To simplify the drawing, the housing that supports the components discussed below and the specimen have been omitted from the drawing. ATR objective 40 includes a first reflector 41 having a parabolic reflective inner surface 42 that focuses light reflected from a second parabolic reflector 43 . Second parabolic reflector 43 also serves the masking function provided by beam blocker 33 described above. Light in the center portion of collimated light beam 39 is blocked from being imaged onto reflective face 45 . The area of the second parabolic reflector that does not reflect light that reaches point 46 is preferably coated with a light absorbing material to prevent light reflected by that area from being reflected back in the direction of collimated light beam 39 . [0037] The light reflected from parabolic reflective inner surface 42 is focused to a point 46 on reflective face 45 of optical element 44 . The light reflected from reflective face 45 is collimated back into a beam that traverses the same path as collimated light beam 39 . The location of point 46 depends on the orientation of collimated light beam 39 relative to the aperture of input port 47 . [0038] Refer now to FIG. 5 , which illustrates the collimated beam motion used to scan the focus point over the reflective face of an ATR objective. In general, an ATR objective has an input port 52 that is characterized by a point 51 at which the central ray 53 of the collimated input beam intersects the plane of the input port. The scanning motion causes the input collimated light beam to change orientation with respect to input port 52 in a manner in which the intersection of central ray 53 with input port 52 maintains central ray 53 such that central ray 53 always passes through point 51 . That is, central ray 53 pivots about point 51 . The orientation of central ray 53 can be characterized by the angle 55 of central ray 53 with an axis that passes through point 51 and is normal to the input port plane, and by an angle 56 between an axis in the plane of input port 52 and the projection of central ray 53 onto the plane of input port 52 . Hence, to cause the focus point on the reflective surface to scan the reflective surface, an optical system that maintains the central ray of the input beam such that it pivots through point 51 but varies angles 55 and 56 is required. [0039] Refer now to FIG. 6 , which illustrates a scanning spectrometer according to one embodiment of the present invention. Light from laser 61 is split by beam splitter 62 into two beams. The first beam is directed to detector 63 a, which measures the intensity of the laser pulse. The second beam is directed to position modulator 64 which adjusts the point of illumination of the beam on an off-axis parabolic reflector 65 . The position of illumination determines the position at which the light from parabolic reflector 65 strikes a second off-axis parabolic reflector 66 . Parabolic reflector 66 re-collimates the beam and sets the diameter of the beam to match the input aperture of ATR objective 67 . The inclination of the beam entering ATR objective 67 is determined by the point of illumination on parabolic reflector 65 . The light reflected back by ATR objective 67 retraces the path of the incoming light and a portion of that light is directed by beam splitter 62 into detector 63 b. Controller 69 can then determine the amount of light that was lost in the reflection from ATR objective 67 , and hence, determine the amount of light absorbed by specimen 16 . To image another small area on specimen 16 , controller 69 operates a three axis stage 68 . [0040] The above-described embodiments utilize a position to cause a collimated light beam to scan the surface of a parabolic mirror. In one aspect of the invention, a parabolic mirror is constructed from two moving mirrors. Refer now to FIG. 7 , which illustrates a parabolic mirror that utilizes two moving minors to cause a collimated light beam to scan in two dimensions. Parabolic mirror 70 includes a first mirror 72 that causes the input beam 71 to scan in a first direction, X′, and a second mirror 73 that causes the output of the first mirror to scan in a second direction, Y′. Minors 72 and 73 are caused to rotate about axes 74 and 75 , respectively, by actuators 76 and 77 , respectively. The actuators can be constructed from galvanic actuators that cause a single mirror to rotate back and forth. The actuators can also be constructed from a polygon scanning mirror that rotates continuously. A MEMS resonator that deflects a single minor with respect to two axes can also be utilized. [0041] Other forms of optical deflectors could also be utilized to cause the beam to scan in two dimensions. For example, acoustic-optical deflectors and electro-optical scanners are also known to the art. In addition, deflectors based on piezo-actuator are known. [0042] It would be advantageous to combine the ability to perform ATR imaging spectroscopy with that of a MIR reflective spectrometer such as imaging system 10 described above with respect to FIG. 1 . In one aspect of the invention, the ATR imaging spectrometer 60 shown in FIG. 6 is modified to include a second MIR objective to provide a dual mode scanning spectrometer. Refer now to FIG. 8 , which illustrates one embodiment of a dual mode MIR spectrometer according to the present invention. Spectrometer 80 is similar to ATR imaging spectrometer 60 in operation when ATR imaging is utilized, and hence, the components of spectrometer 80 that serve the same functions as components of ATR imaging spectrometer 60 are given the same numerical labels and will not be discussed further here. Spectrometer 80 includes a moveable parabolic mirror 82 which is moved such that moveable parabolic mirror 82 intercepts the light from parabolic reflector 65 , collimates that light, and directs the collimated light beam to a MIR objective 81 that focuses the collimated beam on specimen 16 . Parabolic reflector 65 is moved via an actuator that is part of parabolic reflector 65 and controlled by controller 69 . To simplify the drawing, the actuator and connection to controller 69 have been omitted from the drawing. [0043] When position modulator 64 modulates the position of the light beam striking parabolic reflector 65 , the resulting motion causes collimated beam 83 to alter its orientation relative to the input aperture of MIR objective 81 , and hence, scan a small area on specimen 16 . To scan a larger area, the sample must be repositioned relative to MIR objective 81 . The repositioning can be performed by stage 68 or another mechanism that enhances the speed with which MIR objective 81 moves with respect to specimen 16 . [0044] To scan a large area on a sample using ATR mode, the large area must be divided into smaller areas that are scanned by positioning the ATR objective over the area of interest and then moving the ATR objective such that it touches the sample surface. This motion requires the stage to be moved in at least two directions between scan areas. In contrast, when scanning in the MIR reflective mode, the sample does not have to be in contact with the objective. Hence, when moving from one small area to the next, the sample and stage need only move in one direction with respect to one another. The mass of the objective is much less than the mass of the stage, and hence, it is advantageous to move the objective in one direction rather than moving the stage in that direction. [0045] Refer now to FIG. 9 , which illustrates a scanning reflective objective that can be used in the spectrometer shown in FIG. 8 . Objective 91 is mounted on a rail 92 that moves in the Y-direction. Objective 91 includes a mirror 93 that directs a collimated beam of light to a optical system 94 that focuses that light to a point on specimen 16 . To simplify the drawing a single lens is shown in the drawing; however, it is to be understood that the optical system can involve a number of lens elements. The mass of objective 91 is much smaller than that of stage 98 , and hence, stage 98 can be moved at a much faster speed. Rail 92 includes a linear actuator 95 that couples to objective 91 to provide the required motion 97 . A mirror 96 moves collimated beam 83 shown in FIG. 8 to objective 91 . In one aspect of the invention, position modulator 64 shown in FIG. 8 can be operative during the scanning with objective 91 to provide a small scanning amplitude in the X-direction while objective 91 is moved in the Y-direction. This aspect of the invention allows the spectrometer to image in a spatial band, and hence, reduce the number of Y-positions that must be provided by stage 98 to scan a given area. [0046] The above-described embodiments of the present invention have been provided to illustrate various aspects of the invention. However, it is to be understood that different aspects of the present invention that are shown in different specific embodiments can be combined to provide other embodiments of the present invention. In addition, various modifications to the present invention will become apparent from the foregoing description and accompanying drawings. Accordingly, the present invention is to be limited solely by the scope of the following claims.

A scanner and an attenuated total reflection (ATR) objective for use in such scanners are disclosed The ATR objective includes first and second optical elements and an input port. The input port receives an input collimated light beam that is focused to a point on a planar face of the first optical element by the second optical element such that substantially all of that portion is reflected by the planar face and no portion of the input beam strikes the planar face at an angle greater than the critical angle. The second optical element also generates an output collimated light beam from light reflected from the planar face that is characterized by a central ray that is coincident with the central ray of the input collimated light beam. A light beam converter receives the first collimated light beam and generates the input collimated light beam therefrom.

FIELD OF THE INVENTION This invention relates to systems and processes for the dry laying or forming of a web of textile fibers commonly called airlay web formers, and more particularly to the systems and processes for providing the air to the airlay web formers. BACKGROUND AND SUMMARY OF THE INVENTION In the airlay web forming process in use by E.I. du Pont de Nemours and Company (DuPont) in the manufacture of spunlaced fabrics sold under the trademark Sontara®, fiber is carried by a relatively fast moving air stream to a screen conveyor forming a web of randomly arranged fibers. The commercial process is disclosed and described in U.S. Pat. No. 3,797,074 to Zafiroglu. While the Zafiroglu arrangement has been in successful use for a number of years, the webs formed thereby are generally not uniform, and the edges are often completely unacceptable. At the edges, as much as six to eight inches at both sides must be separated and removed from the web because of the irregularities and defects which will lead to defects in the final product. Typically, the edge portions of the fiber are vacuumed away to render relatively clean cut edges of the batt. While the fiber is recovered to be subsequently reformed into the web, the inability to utilize the full width of the manufacturing capability has reduced the productivity of the system. Upon investigation, it has been hypothesized that the air flow which carries the fiber to the screen conveyor has vortices or turbulence at the peripheral sides which renders the unsatisfactory product. In accordance with Zafiroglu, the air that is used to carry the fiber is introduced through a system of large conduits and fans. Prior to receiving the fiber, the air flow is directed through screens and straighteners to provide a uniform flow substantially free of large-scale turbulence and vortices. Thereafter, the large volume, relatively slow moving air flow is accelerated through a converging section or nozzle into a reduced cross sectional area conduit which is substantially flat and wide to be suited for laying down a wide web. It is believed that the Zafiroglu designed acceleration nozzle creates, or allows the creation of, the vortices and turbulence at the peripheral sides which is believed responsible for the edge defects. Accordingly, it is an object of the present invention to provide an airlay web former arrangement which substantially reduces the edge defects of the web and overcomes the drawbacks of the present arrangements as described above. It is a more particular object of the present invention to provide an arrangement for accelerating an airstream for an airlay web former which provides a substantial improvement over present designs in avoiding the creation or development of large scale turbulence and vortices. The above and other objects of the invention are achieved by the provision of an acceleration device which comprises a duct having a generally rectangular cross sectional inlet portion having generally flat straight portions at all of the top, bottom and sides thereof and a generally rectangular cross sectional outlet portion having generally flat straight portions at all of the top, bottom and sides thereof. The cross sectional area of the outlet portion is smaller than the cross sectional area of the inlet portion. The device further comprises an acceleration portion between the inlet and outlet portions wherein all of the top, bottom and sides converge inwardly from the cross sectional shaped inlet portion to the cross sectional shaped outlet portion. The invention may also be characterized by the converging portions of the device having a shape wherein the converging portions have a continuously differentiable curvature. BRIEF DESCRIPTION OF THE DRAWINGS Some of the objects of the invention have now been stated and others may become apparent as the description of the invention proceeds. The invention may be more easily understood by reference to the accompanying drawings in which: FIG. 1 is a perspective view of a preferred embodiment of an airlay web former including an improved air acceleration arrangement which is at the heart of the present invention; FIG. 2 is a fragmentary cross sectional view of the air acceleration arrangement taken along line 2--2 of FIG. 1; FIG. 3 is a fragmentary cross sectional view of the air acceleration arrangement taken along line 3--3 of FIG. 1; FIG. 4 is an enlarged fragmentary view of the air acceleration arrangement taken along FIG. 4--4 of FIG. 1; FIG. 5 is an enlarged fragmentary cross sectional view of the air acceleration arrangement taken along FIG. 5--5 of FIG. 1; FIG. 6 is an enlarged fragmentary view of the area defined by oval 6 in FIG. 3 particularly to illustrate the contour of the side wall of the acceleration nozzle of the present invention; and FIG. 7 is a graphical representation of the curvature of the side wall of the acceleration nozzle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to FIG. 1, an airlay web former is generally indicated by the number 10. More detailed descriptions of arrangements for airlay web formers are set forth in U.S. Pat. Nos. 3,768,120 (Miller) and 3,797,074 (Zafiroglu), which are hereby incorporated by reference herein. The web former 10, as illustrated, utilizes a flow of air which is provided through a duct 15. Within the duct 15, as is more clearly shown in FIG. 2, there are included filters 16 and straighteners 17 to eliminate or substantially reduce large-scale turbulence and vortices that may have been created by a fan or impeller or by the duct work, etc. The air flow through the duct 15 is preferably rather slow to permit effective straightening thereof. Accordingly, the duct 15 has a rather large cross section to permit a large volume of air to move slowly therethrough. An acceleration arrangement 20 (sometimes referred to as a nozzle) is connected to the end of the duct 15 and has a reducing cross section to increase the velocity of the air passing therethrough. The particulars of the acceleration arrangement 20 will be described in more detail below. An airlay duct 40, which has a size corresponding to the outlet of the acceleration arrangement 20, is connected to the end of the nozzle which is arranged to convey the air flow along a path which accepts the fiber to be laid into a web and lay down the fibers. The airlay duct 40 is arranged in conjunction with a disperser roll 45 which feeds fibers from a batt 55 into the air stream. The fibers are carried down the airlay duct 40 to a screen conveyor belt 50 and deposited thereon to form the web W. The air which carries the fiber preferably passes through the foraminous belt 50 and is collected in the collection duct 60. The collection duct 60 carries the air out of the airlay equipment to be vented to the atmosphere or recycled to lay more fiber. Turning now to the particulars of the acceleration arrangement 20 in FIGS. 2 and 3, the nozzle comprises top and bottom panels 21 and 22 and opposite side panels 23 and 24. The acceleration arrangement 20 has an inlet end 25 connected to the conduit 15 and an outlet end 26 connected to the airlay duct 40. The nozzle is preferably formed of galvanized sheet metal which is welded along the seams. The preferred arrangement also includes external reinforcement, which is not shown for illustration purposes, for reducing the flexing of the panels. Clearly, there are many useful materials and construction techniques which could be used to construct the invention, as would be apparent to those skilled in the art of manufacturing air ducts and other similar industrial equipment. Since the acceleration arrangement 20 forms the nucleus of the present invention there are several features thereof that should be highlighted. For example, the acceleration arrangement 20 is arranged to have a discharge end 26 that is smaller in both width and height than it is at its inlet end 25. In the prior arrangement, the width dimension remained the same while the height dimension alone was substantially reduced. In addition, the specific contours of the top, bottom and side walls 21, 22, 23, and 24 of the acceleration arrangement 20 have been substantially engineered and refined to reduce the creation of large-scale turbulence and vortices. In particular, the contours are arranged to be curving such that the curvature is continuously differentiable between the ends. Another feature worthy of being highlighted is that the seams at which the walls intersect are provided with fillets to provide a smoother surface along which the air can move. In the preferred arrangement, the fillets gradually increase in dimension from the inlet to the outlet end of the nozzle. The first highlighted feature is that all of the panels 21, 22, 23, and 24 are inwardly curving to reduce the dimension from the inlet to the outlet in both width and height as is best illustrated in FIGS. 1, 2 and 3. This is quite in contrast to the prior arrangement which has straight and parallel side panels such that only the vertical dimension of the conduit is reduced. In the preferred embodiment, all the panels deviate or converge approximately the same amount or dimension: however, it is certainly not necessary that the side panels 23 and 24 converge to the same degree as the top and bottom panels 21 and 22. It is not certain how much the lateral convergence of the nozzle in addition to the vertical convergence has contributed to the success of the present design, but since most of the improvement in the new design has focused on the lateral edges of the wide fibrous web formed by the airlay process, it is believed that this is an important feature of the present invention. The second highlighted feature of the new arrangement is that the panels have a contour which has a continuously differentiable curvature between it ends. Continuously differentiable curvature is a curve that has a particular smoothness or that changes curvature gradually. The present invention has a continuously differentiable curvature and is best illustrated in FIG. 6 where it is enlarged compared to the other drawing figures. Continuously differentiable curvature may be more easily understood when considered mathematically. Curvature for an algebraically defined curve is generally calculated by the following formula: ##EQU1## wherein: K(x) = the curvature of the curve as a function of a position x along a reference line. ##EQU2## It is noted that the curve is most easily considered if it is a simple algebraically defined curve. However, the first and second derivatives may still be determined at various points along the curve and thus the curvature may be plotted therefrom. Considering a plot of the curvature as seen in FIG. 7, and comparing it to the contoured panel as seen in FIG. 6, it should be seen that a continuously differentiable curve does not have abrupt changes in curvature. The contour or curve of the panels of the present invention can be described as having several key areas. Consider first, the end points 71 and 72. At the first end point 71, the angle θ is zero so that the panel is essentially parallel to the corresponding wall of the conduit 15. The curvature is also zero as seen in FIG. 7. From the end point 71, the curvature of the panel then increases rapidly to a peak at a first maximum curvature point 74. By referring now to the plot in FIG. 7, a peak curvature should be noted at the left portion of the plot which would be associated with the curvature of the first maximum curvature point 74. The curvature of the panel thereafter begins to decrease. At about a midpoint 73, the panel reaches an inflection where the curve changes to the opposite direction. This is about where the maximum angle θ of the panel is achieved and where the curvature will equal zero. As should be particularly noted in the plot in FIG. 7, the curvature smoothly decreases or settles to a value of zero at the inflection point 73 rather than an abrupt change to zero curvature. This smooth or gradual change in curvature is a significant feature of the present invention. The plot indicates that the curvature gradually increases again after the inflection in a manner similar to the way the curvature decreased to zero. Again, this is the continuously differentiable curvature. As noted above, the contour has a certain symmetry which is best illustrated in the plot of the curvature. The maximum curvature is again attained at a second maximum curvature point 75 before decreasing to zero curvature at the end point 72. Also at the end point 72, the angle θis equal to zero so that the panel is essentially parallel to the corresponding wall of the airlay duct 40. As such, continuously differentiable curvature should be understood to mean that the curvature changes gradually or that a plot of the curvature of the curve would not have abrupt changes. It is believed that a conveyor nozzle having continuously differential curvature panels provide for continuously varying boundary pressure from the inlet portion to the outlet portion. The feature of the symmetry referred to above, may be best seen for the panel by considering that it may be rotated end for end about an axis extended transversely through the inflection point 73 such that the end point 72 would be in the position of the first end point 71. One feature that is probably not very apparent from the drawings or from the plot of the curvature, but which is also believed to substantially contribute to the minimization of large-scale turbulence and vortices, is the maximum angle of the panel to the centerline. In the prior arrangements the maximum angle θwas approximately 25 degrees. In the present invention, the maximum angle is about 16.7 degrees. As such, the lower slope provides a more gradual acceleration of the air flow while still providing a curved transition at the inlet and outlet ends 25 and 26 of the nozzle. It is recognized that the curvature is greater near the ends of the panels (as shown by the high peaks in the curvature in the plot in FIG. 7), but this apparently does not offset the better performance of the lower slope. In the prior existing arrangement, the contour of the top and bottom panels is a combination of a straight section which converges toward the centerline with curved transition portions at the inlet and outlet ends. The transition portion from the straight inlet end is more dramatic (greater curvature) than the more gradual transition back to the straight outlet end (less curvature). This provided a greater angle θbetween the panel and the centerline of the prior existing nozzle. The curve of the panel of the preferred embodiment of the present invention has been defined mathematically by a seventh order polynomial equation such as illustrated as follows: y=ax.sup.7 +bx.sup.6 +cx.sup.5 +dx.sup.4 +ex.sup.3 +fx.sup.2 +gx +h By defining the location of the end points, the angle θof the end portion of the panels being zero, the curvature of the end portions being zero, and the curve being symmetrical about its transverse axis, the coefficients of seventh order polynomial can be determined. Since the end points are defined by the particular installation which will be defined by the needs of the particular airlay system, the coefficients of the polynomial equation will be different although the various curves will have a rather similar appearance. In the present invention, the non zero value of "a" in the above seventh order polynomial, in large part, provides the gradual changes in curvature at the inflection point. The fillets 27 are provided to further alleviate potential causes of large-scale turbulence and vortices. As noted above, the prior existing nozzle design provided for the panels to intersect in sharp perpendicular seams. In the preferred embodiment the fillets 27, which are essentially concave chamfers inside the duct, are provided to grow or increase in size from the inlet end 25 toward the outlet end 26. Thus, the fillets 27 have a smaller radius near the inlet 25 and a larger radius nearer to the outlet 26. The fillets are generally indicated by the number 27, but are indicated 27a and 27b in FIGS. 4 and 5 to show how the fillets are larger nearer the outlet end 26. In accordance with this preferred arrangement, the airlay conduit 40 may also be provided with fillets that correspond in size to the fillets 27b near the intersections of the nozzle and the airlay conduit. The foregoing description is intended to provide a clear understanding of the invention and not to limit the scope of protection provided by any patents issued for this invention. The scope of the invention is set forth in the following claims.

This invention relates to an improved air acceleration nozzle for use in airlay web formers which reduce the creation of large scale vortices and turbulence. The nozzle accelerates the air by reducing the cross sectional area of the conduit. The size of the conduit for the air is reduced in both lateral dimensions, and more preferably, both dimensions are reduced with smoothly curving, low angle peripheral walls.

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims the benefit of Netherlands Patent Application Serial No. 1035066, filed Feb. 22, 2008 which is hereby incorporated by reference in its entirety. FIELD OF THE INVENTION The invention is in the field of radar and similar ranging techniques, which detect remote targets and determine target parameters such as range and radial velocity. The invention relates to the signal structure and associated processing technique that estimates the target range and radial velocity. BACKGROUND OF THE INVENTION The remote detection systems determine target parameters such as range and radial velocity by transmitting a waveform and comparing, through various processing methods, the transmitted waveform and the received signal that is echoed from the target. The range of the target is determined through the measurement of the time of arrival of the echo and the radial velocity is measured from the Doppler effect, which is caused by the signal echoing from a target with non-zero radial velocity. The Doppler effect manifests itself as a shift in the frequency in single carrier radars when the narrow band signal approximation is valid. To measure the Doppler effect, the phase of the received echo is compared to the phase of the transmitted signal. The technique used for measuring the frequency shift depends on the radar waveform. The important attributes of a radar system, among others, are the range and radial velocity resolution and ambiguity. The resolution is the minimum parameter spacing between the two targets so that they are identified by the radar system as distinct targets. Ambiguity is the case when the measured waveform parameter value may correspond to more than one target parameter value. With the choice of waveform and processing technique determining the resolution and ambiguity, the goal is to measure the target parameters unambiguously for a given maximum range and velocity with high resolution. Current tendency in radar systems is to form networks of radars to improve the system performance through data fusion. Such networking must be accomplished through a communication system that is independent of the commercial communication infrastructure for reliability requirements. Wireless communication is preferable for the same reason. Embedding the communication into the radar signal is considered as a solution that enables the double use of the radar transmitter, with increased communications security. In pulsed Doppler radars, the ambiguity in the radial velocity is solved by varying the pulse repetition frequency (PRF) or the carrier frequency (RF) from burst to burst. The maximum unambiguous radial velocity is related to the pulse repetition frequency and the carrier frequency through the equation v u , max = 1 2 ⁢ f p ⁢ λ , where f p is the pulse repetition frequency and λ is the carrier wavelength. Varying any of two results in a different maximum ambiguous velocity. The velocity obtained from Doppler processing can be written as v=v 0 +nv μ,max , where v is the actual velocity, v 0 is the measured velocity that is smaller than the maximum unambiguous velocity, and n is an integer number. When two different maximum unambiguous velocities are obtained through varying the PRF or RF, the actual velocity can be determined through the equation above. The choice of PRF affects the range ambiguity as well. The maximum unambiguous range that can be measured with given PRF is R u , max = 1 2 ⁢ c f p . Similar to the Doppler ambiguity, the range measurement obtained from the range processing can be written as R=R 0 +nR μ,max , where R is the actual velocity, R 0 is the measured velocity that is smaller than the maximum unambiguous velocity, and n is an integer number. Pulsed radars have limited transmission power capability due to the low duty cycle required for unambiguous and high-resolution range measurement. Pulse compression techniques increase the average transmitted power by spreading the pulse energy over a longer portion of the pulse period. One pulse compression technique is the phase coding of the transmitted waveform, where phase codes can be arranged to produce favorable range profiles with lower range sidelobes. The range is measured by the correlation of the transmitted phase coded waveform with the received echo. The correlation peaks correspond to the locations of the significant reflectors, and the phase variation of the correlation peaks from pulse to pulse is used to measure the radial velocity of the reflectors. Another pulse compression technique is to transmit a chirp pulse that sweeps a frequency band for the pulse duration. As the beat frequency, resulting from the mixing of the replica of the transmitted signal and the received echo, is governed by both the delay and the frequency shift due to target radial velocity, the range and radial velocity measurements are coupled to each other in linear FM pulsed radar. The radial velocity ambiguity persists, since the phase variation of the correlation peaks from pulse to pulse is used to measure the radial velocity of the reflectors as in phase coded pulsed radar. Continuous wave (CW) radars can have phase-coded or frequency modulated signals, similar to pulsed radars. Mathematically the CW radar signal can be considered as a pulse train composed of pulses with 100% duty cycle. The same pulse compression and Doppler measurement techniques apply to the CW radar. U.S. Pat. No. 6,392,588 discloses multi-carrier radar signal with the emphasis on reduction of the range sidelobes and low peak to mean envelope power ratio, provided by the use of specific phase sequences for modulating the carriers. The phase sequences proposed in the patent, named Multifrequency Complementary Phase Coded (MCPC) signal, are based on the modulation of M sub-carriers by sequences of length M that comprise a complementary set. The range sidelobes are controlled through frequency weighting and use of additional pulses so that sequences along a carrier constitute a complementary set in time. The Doppler tolerance of multi-carrier radar signal is inspected in the article: G. E. A. Franken, H. Nikookar, P. van Genderen, “ Doppler Tolerance of OFDM - Coded Radar Signals ”, Proc. 3 rd European Radar Conference, September 2006, Manchester UK. The degradation of the pulse compression gain for the OFDM waveform is demonstrated in the article, with the proposal of a bank of Doppler filters, responses of which intersect at 1 dB compression loss. The filter bank is proposed to be constructed by using reference signals in the compression filter that are frequency shifted to obtain the response explained above. Dual use of OFDM as the radar waveform and for communications is inspected in the article: D. Garmatyuk, J. Schuerger, T. Y. Morton, K. Binns, M. Durbin, J. Kimani, “Feasibility Study of a Multi-Carrier Dual-Use Imaging Radar and Communication System,” in Proc. 4 th European Radar Conf, 2007, pp. 194-197. The inspection considers the SAR imaging with OFDM waveform and communications through OFDM separately. U.S. Pat. No. 6,720,909 discloses processing technique for single carrier pulsed Doppler radar waveform. The technique solves the Doppler and range ambiguity by staggering the pulse positions. The staggering enables the solving of the range ambiguity caused by the pulse interval being shorter than the maximum range of interest. The staggering also increases the maximum unambiguous radial velocity to a higher value, which is determined by the lowest bisector of the staggered pulse intervals. In pulsed Doppler radar systems the pulse repetition frequency or the carrier frequency is varied from burst to burst to resolve the ambiguity in radial velocity. However, as the radial velocity resolution is determined by the time on target, the parameter change can be realized only after the required resolution is achieved with the current pulse burst. This, in turn, requires the radar beam to spend longer time on target. The pulse compression techniques based on phase coding of the transmitted pulse are intolerant to Doppler; the compression gain rapidly decreases with the increasing Doppler effect. The exacerbating of the pulse compression depends on the phase shift introduced by the Doppler effect during one phase chip in the pulse, and significant range side lobe deterioration is reported for phase shifts exceeding 30-40 degrees per chip in the article: R. M. Davis, R. L. Fante, R. P. Perry, “ Phase - Coded Waveforms for Radar ”, IEEE Trans. Aerospace and Electronic Systems, vol. 43, No. 1, January 2007. In the article above the use of shorter compression pulses or multiple pulse compression filters with each filter tuned to a different Doppler frequency is proposed for mitigating the Doppler intolerance. Shorter compression pulses correspond to higher pulse repetition frequency if the peak and average power levels are to be kept constant, which in turn causes ambiguity in range. The second approach in the article is to use a bank of pulse compression filters with each filter matched to the replicas of the transmitted waveform with different Doppler frequency. In the article the use of the filters is restricted to the mitigating of the compression loss; data from different coherent processing intervals is needed to solve the ambiguity in radial velocity, which corresponds to using multiple trains of pulses. U.S. Pat. No. 6,392,588, which discloses the multicarrier MCPC waveform, does not address the radial velocity resolution, ambiguity arising from the use of the pulsed waveform, the deterioration of pulse compression due to the Doppler effect and possible solutions to the Doppler intolerance of the pulse compression. The article: G. E. A. Franken, H. Nikookar, P. van Genderen, “ Doppler Tolerance of OFDM - Coded Radar Signals ”, Proc. 3 rd European Radar Conference, September 2006, Manchester UK, does not propose any solution to the Doppler ambiguity. The proposed technique aims to mitigate the compression loss resulting from the Doppler effect only. Furthermore, no structure to implement the Doppler shifted filters is proposed. A Doppler radar using two multi-carrier pulses is proposed in the article: J. Duan, Z. He, C. Han, “ A Novel Doppler Radar Using only Two Pulses ”, Radar 2006, CIE '06, October 2006. The differential phase between the two pulses for each carrier is measured to determine the radial velocity of the target. While the article addresses the unambiguous measurement of the radial velocity, the Doppler resolution is not considered. Moreover, the carriers are assumed to be recoverable independently after the range gate alignment, which does not take in to account that the frequency components are not orthogonal anymore when the receiving frame is not aligned with the reflected echo. Possibility of coding on the carriers is not mentioned, assuming the transmission of the same pulse twice without any coding. Such pulses have very high Peak to Average Power Ratio (PAPR), leading to very low average transmitted power and possibly distortion due to the amplifier entering the saturation region. In the article: D. Garmatyuk, J. Schuerger, T. Y. Morton, K. Binns, M. Durbin, J. Kimani, “Feasibility Study of a Multi-Carrier Dual-Use Imaging Radar and Communication System,” in Proc. 4 th European Radar Conf, 2007, pp. 194-197, the Doppler effect is not considered, as the Doppler information is of no interest for the intended SAR application. Thus, the focus in the article is on cross-range imaging. U.S. Pat. No. 6,720,909 is related to the single carrier pulsed Doppler radar waveforms, where the duty cycle and the average transmitted power is low. Pulse compression techniques to improve the average transmitted power are not considered. An embodiment of the invention disclosed here solves the Doppler ambiguity by means of Doppler compensation before the pulse compression, at the same time improving the average power and enabling high signal bandwidth thanks to the multi-carrier structure. Failing at combining the multiple functionalities that exist individually, the prior art teaches that consecutive pulse trains with different RF or different PRF must be used to solve the radial velocity ambiguity. This is one of the problems that an embodiment of the present invention aims at solving. The method given in the article: J. Duan, Z. He, C. Han, “ A Novel Doppler Radar Using only Two Pulses ”, Radar 2006, CIE '06, October 2006 cannot be applied on the other multi-carrier waveform schemes that do not consider the Doppler effect. The proposed method requires transmission of the same multi-carrier waveform twice without any coding on the carriers, while the other methods require specific coding of the carriers. The guard interval is not considered in the indicated previous art. Guard interval is a crucial component of the multi-carrier waveform. The multi-path effects are eliminated from the waveform when the guard interval duration is longer than the channel length. Multi-path effects introduce inter-symbol interference and inter-carrier interference, leading to high bit error rate in communications. Introducing cyclic repetition of the waveform as the guard interval may introduce range ambiguity, a problem that is solved inherently in an embodiment of the present invention due to the receiving scheme being designed to utilize the cyclic prefix. The cyclic prefix is utilized in the embodiment as in a communications waveform, with the duration of the cyclic prefix being longer than the response time from the maximum range of interest. Such timing constraint enables the recovery of the carriers' starting phases, which enables both the Doppler frequency shift compensation and the pulse compression. SUMMARY OF THE INVENTION An embodiment of the present invention aims to provide a processing technique that is applicable to a pulse compression waveform with multi-carrier structure, which includes an OFDM waveform. The proposed waveform and the corresponding processing technique measures the radial velocity using a pulse train, without the need for using consecutive pulse trains with different RF or different pulse repetition frequencies to solve the radial velocity ambiguity. An important idea of the processing technique is based on the deteriorating pulse compression gain due to the Doppler effect manifesting itself as RF frequency shift. According to one of its aspects, an embodiment of the present invention may provide a method for measuring the radial velocity of a target with a radar. The method includes a step of transmitting an OFDM waveform including N frequency carriers (p m ) °m°ε°{0, . . . , N−1} transmitted simultaneously, where N°≧°2, the frequency carriers (p m ) °m°ε°{0, . . . , N−1} being coded in order to improve the Doppler response. The waveform p includes OFDM chips and guard time intervals that are transmitted successively to form a continuous wave transmission, the duration T cyc of the guard time intervals being longer than 2 ⁢ R max c , where c is the speed of the light, which is the time necessary for the waveform p to be reflected from a maximum range of interest R max . The method also includes a step of receiving the waveform echoed from the target. The initial phase φ m of each frequency carrier p m is recovered from the waveform echoed. The recovered initial phase φ m of each frequency carrier p m is cyclically shifted in order to compensate for the Doppler effect. The recovered initial phase φ m of each frequency carrier p m is decoded. A compressed pulse is synthesized from the decoded initial phases (φ m ) °m°ε°{0, . . . , N−1} . Preferably, the initial phase φ m of each frequency carrier p m may be recovered from the waveform echoed by virtue of a Discrete Fourier Transform, which includes multiplying a vector s containing samples of the waveform echoed by a Discrete Fourier Transform matrix ℑ, and which can be implemented through a Fast Fourier Transform (FFT) algorithm. The recovered initial phase φ m of each frequency carrier p m may be cyclically shifted by a processing, which includes multiplying the output from the preceding algorithm by a matrix C −1 , the matrix C representing the shifting of the frequency carriers (p m ) °m°ε°{0, . . . , N−1} due to the Doppler effect. The recovered initial phase φ m of each frequency carrier p m may be decoded by a processing, which includes multiplying the output from the preceding processing by a matrix P=diag {φ°} where φ T =[φ 0 φ 1 φ 2 . . . φ N−1 ]. The compressed pulse may be synthesized from the decoded initial phases by virtue of an Inverse Discrete Fourier Transform, which includes multiplying the output from the preceding processing by the matrix ℑ −1 , and which can be implemented through an Inverse Fast Fourier Transform (IFFT) algorithm. For example, the frequency carriers (p m ) °m°ε°{0, . . . , N−1} may be coded in phase by uniformly distributing their initial phases (φ m ) °m°ε°{0, . . . , N−1} over a [0; 2π[ interval. The frequency carriers (p m ) °m°ε°{0, . . . , N−1} may also be coded in amplitude by applying a set of weightings. For example, the set of weightings may be a set of Hamming coefficients. Preferably, the OFDM waveform may include OFDM chips and guard time intervals that may be transmitted successively to form a continuous wave transmission. The duration T cyc of the guard time intervals being longer than 2 ⁢ R max c , where c is the speed of the light, which is the time necessary for the OFDM waveform to be reflected from a maximum range of interest R max . Then, the recovered initial phases φ m of each frequency carrier p m may preferably be cyclically shifted so as to cover all velocities of interest. This may enable to generate Doppler profiles that cover only the velocity range corresponding to the cyclic shift, thus solving the Doppler ambiguity. Preferably, the energy in the ambiguity corresponding to f d = ( s + 1 ) ⁢ Δ ⁢ ⁢ f ( 1 + α ) may be lowered down to A s , OFDM =  sin ⁢ ⁢ c ⁡ ( s ⁢ ⁢ π 1 + α )  , where s is a positive integer and α is the ratio of the duration T cyc of the guard time interval to the duration of the OFDM chip. BRIEF DESCRIPTION OF THE DRAWINGS Non-limiting examples of the invention are described below with reference to the accompanying drawings in which: FIG. 1 illustrates a pulse burst Doppler processing scheme; FIG. 2 illustrates a comparison of timing and range profile; FIG. 3 illustrates a modification of the ambiguities in the case of a uniform pulse train, in the case of a single OFDM chip and in the case of an OFDM pulse train; FIG. 4 illustrates an example of scenario; FIG. 5 illustrates range profiles for Doppler Fast Fourier Transform (FFT) outputs; FIG. 6 illustrates a Doppler processing solving the ambiguity, overall response; FIG. 7 illustrates a Doppler processing solving the ambiguity, FFT for different Doppler compensation; FIG. 8 illustrates a Doppler processing solving the ambiguity, Doppler compensation response; FIG. 9 illustrates a Doppler processing solving the ambiguity, ambiguity in the FFT response. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The signal structure utilizes multiple carriers forming the OFDM waveform. The OFDM waveform p(n) is the sum of carriers p k (n), presented in discrete form as p ⁡ ( n ) = ∑ m = 0 N - 1 ⁢ x m ⁢ exp ⁢ { jϕ m } ⁢ exp ⁢ { j2π ⁢ ⁢ m ⁢ ⁢ Δ ⁢ ⁢ f ⁡ ( n N - 1 ) ⁢ T } , ( 1 ) where x m exp{jφ m } is the amplitude and phase of the complex symbol modulating the carrier m, N is the number of carriers, and T=1/Δf is the symbol duration with Δf the carrier spacing. Thus, carrier m has amplitude x m and initial phase φ m . The complex symbols modulating each carrier can be considered as being transmitted in parallel. The processing method presented here imposes no limitations on the choice of the phases of the symbols, covering all phase coding schemes as applied in radar and communication applications. The carriers are said to be orthogonal under the relation: c k = ∑ n = 0 N - 1 ⁢ ∑ m = 0 N - 1 ⁢ x m ⁢ exp ⁢ { jϕ m } ⁢ exp ⁢ { j2π ⁢ ⁢ m ⁢ ⁢ Δ ⁢ ⁢ f ( n N - 1 ) ⁢ T } ⁢ exp ⁢ { - j2 ⁢ ⁢ π ( n N - 1 ) ⁢ k } . ( 2 ) The mathematical relationship between the orthogonal carriers hold only when the waveform, which is called an OFDM chip, is of duration T=1/Δf. Thus, the carriers are orthogonal at the receiver when the received frame is of duration T and completely overlaps with the transmitted chip. To provide robustness against the multipath effects in the communication applications, the OFDM chip is preceded by a guard time interval, which has time duration longer than the channel response. The guard time interval is usually generated by copying a section with the required time duration from the end of the OFDM chip. Such guard time interval is called a cyclic prefix. The timing of the transmission and reception, and their comparison with the range profile is given in FIG. 2 . The transmitted OFDM chip is preceded by the cyclic prefix with duration T cyc ≥ 2 ⁢ R max c , ( 3 ) where R max is the maximum target range that the radar has to detect the target, and c is the speed of the light. The OFDM chips constituting the pulse burst are transmitted successively without any interruptions; the transmitted waveform is actually continuous wave. The received echo from a point target after down-conversion is s ⁡ ( t ) = ∑ m = 1 N - 1 ⁢ exp ⁢ { j2 ⁢ ⁢ π ⁢ ⁢ m ⁢ ⁢ Δ ⁢ ⁢ f ⁡ ( 1 - 2 ⁢ v c ) ⁢ ( t - 2 ⁢ R c ) - j2 ⁢ ⁢ π ⁢ ⁢ f c ⁢ 2 ⁢ R c - j2 ⁢ ⁢ π ⁢ ⁢ f c ⁢ 2 ⁢ v c ⁢ ( t - 2 ⁢ R c ) } ⁢ exp ⁢ { jϕ m } ( 4 ) where R is the range and v is the radial velocity of the point target, and f c is the RF carrier frequency. In this expression the time t starts at the beginning of the transmission of the actual OFDM chip. The receiving of the echoes starts as soon as the cyclic prefix ends and the actual chip starts being transmitted, and the receiving duration is equal to the chip duration. A key element of the OFDM scheme disclosed here is the carrier's being orthogonal to each other. The cyclic prefix extends the waveform duration such that that the echo received from the most distant target constitutes a complete OFDM chip during the received frame. The pulse compression is accomplished by compensating the carriers for their initial phases. This operation concentrates the energy in the received echo around the time domain sample corresponding to the range of the target; thus, the OFDM waveform with zero initial phases on all carriers can be regarded as a pulse in time domain. Most of the energy of the waveform is concentrated on a narrow time span, which is determined by the bandwidth of the waveform. As in pulsed Doppler radar, the Doppler profiles are obtained as the outputs of the DFT over the compressed pulses for each range bin, since the phase variation from the peak of one pulse to the next gives the Doppler shift of the waveform. OFDM waveform is composed of a number of orthogonal carriers, and the Doppler effect on the OFDM waveform can be considered as the shift of the spectrum by an amount determined by the radial velocity of the reflector. The spectrum property of the OFDM enables the Doppler compensation in a straightforward manner by implementing a cyclic shift of the FFT output in the receiver. In this manner no separate hardware is needed to implement the Doppler compensated matched filtering banks or to generate frequency shifted replicas of the reference signal. The Pulse Burst Doppler processing scheme is presented in FIG. 1 . The Pulse Burst Doppler processing is presented here in matrix form. The received samples can be organized into a vector s such that s = ψΓβ ⁢ ⁢ A ⁢ ⁢ φ , ⁢ where ( 5 ) ψ = exp ⁢ { - j2 ⁢ ⁢ π ⁢ ⁢ f c ⁡ ( 1 - 2 ⁢ v c ) ⁢ 2 ⁢ R c } , ⁢ Γ = diag ⁢ { 1 , γ , γ 2 , … ⁢ , γ N - 1 } ⁢ ⁢ and ⁢ ⁢ γ = exp ⁢ { - j2 ⁢ ⁢ π ⁢ ⁢ f c ⁢ 2 ⁢ v c ⁢ 1 N ⁢ ⁢ Δ ⁢ ⁢ f } , ⁢ β = [ 1 1 1 … 1 1 β β 2 β N - 1 1 β 2 β 4 B 2 ⁢ ( N - 1 ) ⋮ ⋱ ⋮ 1 β N - 1 β 2 ⁢ ( N - 1 ) … β ( N - 1 ) 2 ] ⁢ ⁢ and ⁢ ⁢ β = exp ⁢ { - j2 ⁢ ⁢ π ⁢ ⁢ ( 1 - 2 ⁢ v c ) ⁢ 1 N } , ⁢ A = diag ⁢ { 1 , α , α 2 , … ⁢ , α N - 1 } ⁢ ⁢ and ⁢ ⁢ α = exp ⁢ { j2 ⁢ ⁢ π ⁢ ⁢ Δ ⁢ ⁢ f ⁡ ( 1 - 2 ⁢ v c ) ⁢ 2 ⁢ R c } , ⁢ φ T = [ ϕ 0 ϕ 1 ϕ 2 … ϕ N - 1 ] . ( 6 ) where [ ] T is the transpose. The shifting of the carriers due to the Doppler effect is apparent in Γ and β matrices. The β matrix is the same as an Inverse Discrete Fourier Transform (IDFT) matrix when 2v/c<<1. The received signal model includes the time scaling due to the Doppler effect, which modifies the IDFT matrix in the OFDM transmitter scheme. The time scaling is neglected here by replacing β with the IDFT matrix ℑ −1 . The Doppler compensation aims to compensate for this shifting of the carriers due to the Doppler effect coming from the high frequency carrier. The Doppler compensation is accomplished by cyclically shifting the carriers back into their true locations. The received vector s is processed as y=PC −1 ℑs,   (7) where P is the phase compensation matrix, C −1 is the inverse cyclic shift matrix, and ℑ is the Discrete Fourier Transform (DFT) matrix, which is implemented by the FFT algorithm. Submitting s in (5) into (7) yields y=ΨPC −1 ℑΓℑ −1 Aφ   (8) For the velocities: 2 ⁢ v c = k ⁢ f c Δ ⁢ ⁢ f , ( 9 ) where k is an integer, multiplication of ℑ with Γ from the right, as seen in (8), is equivalent to cyclical shifting of the rows of ℑ. The cyclical shifting of the rows of the IDFT matrix can be represented in another form as y=ΨPC −1 Cℑℑ −1 Aφ,   (10) where C is the cyclic shift matrix. The cyclic shift matrix C represents the shifting of the carriers due to the Doppler effect. The IDFT matrix is implemented by an Inverse Fourier Transform (IFFT) algorithm. Hence, the inverse cyclic shift compensates for the effects of the Doppler, enabling the compensation of the initial phases correctly. The phase compensation matrix P is such that P =diag{φ*}  (11) where [ ]* is the complex conjugate. A matrix being diagonal allows the changing of the orders of the A and P matrices. As a result, the phase compensation cancels the beginning phases and only the elements of the matrix A is left in the resulting vector y, which is processed by an IDFT matrix. This processing technique is valid when the received waveform is oversampled in the frequency domain by zero padding before the FFT. The deterioration of the pulse compression gain due to the Doppler effect is exploited to solve the ambiguity arising from the pulse repetition frequency of the pulse burst waveform. The change in the pulse compression gain due to Doppler shift can be determined by considering the ambiguity function of the OFDM waveform. The ambiguity function is defined as χ ⁡ ( τ , f d ) = ∫ - ∞ ∞ ⁢ p ⁡ ( t ) ⁢ p * ( t - τ ) ⁢ ⁢ exp ⁢ { j2 ⁢ ⁢ π ⁢ ⁢ f d ⁢ t } ⁢ ⅆ t ( 12 ) where p(t) is the transmitted waveform, τ is the delay and f d is the Doppler frequency. The processing method disclosed here is equivalent to the discrete form of the ambiguity function. Given in the matrix form in (5), s(n) is equivalent to the delayed and Doppler shifted version of the p(n). Thus, we may write the ambiguity function for single OFDM chip as χ ⁡ ( τ , f d ) = ∫ 0 T ⁢ ( ∑ k = 0 N - 1 ⁢ exp ⁢ { - jϕ k } ⁢ exp ⁢ { - j2 ⁢ ⁢ π ⁢ ⁢ k ⁢ ⁢ Δ ⁢ ⁢ ft } ∑ m = 0 N - 1 ⁢ exp ⁢ { j2 ⁢ ⁢ π ⁢ ⁢ m ⁢ ⁢ Δ ⁢ ⁢ f ⁡ ( t - 2 ⁢ R c ) - j2 ⁢ ⁢ π ⁢ ⁢ f c ⁢ 2 ⁢ R c - j2 ⁢ ⁢ π ⁢ ⁢ f c ⁢ 2 ⁢ v c ⁢ ( t - 2 ⁢ R c ) } ⁢ exp ⁢ { jϕ m } ) ⁢ ⅆ t ( 13 ) which can be written as χ ⁢ ( τ , f d ) = ⁢ ∑ k = 0 N - 1 ⁢ ∑ m = 0 N - 1 ⁢ ∫ 0 T ⁢ ( exp ⁢ { j2 ⁢ ⁢ π ⁢ ⁢ m ⁢ ⁢ Δ ⁢ ⁢ f ⁡ ( t - 2 ⁢ R c ) - j2 ⁢ ⁢ π ⁢ ⁢ f c ⁢ 2 ⁢ R c - j2 ⁢ ⁢ π ⁢ ⁢ f c ⁢ 2 ⁢ v c ⁢ ( t - 2 ⁢ R c ) } exp ⁢ { jϕ m } ⁢ exp ⁢ { - jϕ k } ⁢ exp ⁢ { - j2 ⁢ ⁢ π ⁢ ⁢ k ⁢ ⁢ Δ ⁢ ⁢ ft } ) ⁢ ⅆ t = ⁢ ∑ k = 0 N - 1 ⁢ ∑ m = 0 N - 1 ⁢ ∫ 0 T ⁢ ( exp ⁢ { j2 ⁢ ⁢ π ⁢ ⁢ Δ ⁢ ⁢ f ⁡ ( ( m - k ) ⁢ t - 2 ⁢ R c ) - j2 ⁢ ⁢ π ⁢ ⁢ f c ⁢ 2 ⁢ R c - j2 ⁢ ⁢ π ⁢ ⁢ f c ⁢ 2 ⁢ v c ⁢ ( t - 2 ⁢ R c ) } exp ⁢ { jϕ m } ⁢ exp ⁢ { - jϕ k } ) ⁢ ⅆ t ⁢ ⁢ ⁢ where ⁢ ⁢ ⁢ f d ⁢ = 2 ⁢ ⁢ v c ⁢ f c , ⁢ ⁢ and ⁢ ⁢ ⁢ τ = 2 ⁢ ⁢ R c . ( 14 ) When completely random phases are used such that the expected value of the phase vectors in the complex plane is zero, the terms where m≠k are eliminated. χ ⁡ ( τ , f d ) = ⁢ ∑ m = 0 N - 1 ⁢ exp ⁢ { - j2 ⁢ ⁢ π ( Δ ⁢ ⁢ f + f c ) ⁢ 2 ⁢ R c } ⁢ ∫ 0 T ⁢ exp ⁢ { - ⁢ j2 ⁢ ⁢ π ⁢ ⁢ f c ⁢ 2 ⁢ v c ( t - 2 ⁢ R c ) } ⁢ ⅆ t = ⁢ ∑ m = 0 N - 1 ⁢ exp ⁢ { - j2 ⁢ ⁢ π ( Δ ⁢ ⁢ f + f c ( 1 - 2 ⁢ v c ) ) ⁢ 2 ⁢ R c } ⁢ ∫ 0 T ⁢ exp ⁢ { - ⁢ j2 ⁢ ⁢ π ⁢ ⁢ f c 2 ⁢ v c ⁢ t } ⁢ ⁢ ⅆ t , ( 15 ) The magnitude of the ambiguity function can be simplified further to  χ ⁡ ( τ , f d )  = ⁢  ∑ m = 0 N - 1 ⁢ exp ⁢ { - j2 ⁢ ⁢ π ⁡ ( Δ ⁢ ⁢ f + f c ( 1 - 2 ⁢ v c ) ) ⁢ 2 ⁢ R c } ∫ 0 T ⁢ exp ⁢ { - j2 ⁢ ⁢ π ⁢ ⁢ f c ⁢ 2 ⁢ v c ⁢ t } ⁢ ⁢ ⅆ t  = ⁢  ∑ m = 0 N - 1 ⁢ exp ⁢ { - j2 ⁢ ⁢ π ⁡ ( Δ ⁢ ⁢ f + f c ( 1 - 2 ⁢ v c ) ) ⁢ 2 ⁢ R c }  ⁢  sin ⁢ ⁢ c ⁡ ( π ⁢ ⁢ f d ⁢ T )  = ⁢ N ⁢  sin ⁢ ⁢ c ⁢ { π ⁢ ⁢ f d ⁢ T )  , ( 16 ) This ambiguity function for single OFDM chip forms the basis for the ambiguity function of the pulse burst  χ ⁡ ( τ , f d )  B =  sin ⁢ ⁢ c ⁡ ( π ⁢ ⁢ f d ⁢ T )  ⁢  sin ⁡ ( π ⁢ ⁢ f d ⁢ KT ⁡ ( 1 + α ) ) K ⁢ ⁢ sin ⁡ ( π ⁢ ⁢ f d ⁢ T ⁡ ( 1 + α ) )  , ( 17 ) which is derived in N. Levanon, “Radar Principles”, Wiley 1988. The compression gain modifies the ambiguity that is associated with the pulse repetition frequency of the pulse train, as depicted in FIG. 3 . In the figure, the ambiguities associated with the pulse burst are separated by f d = Δ ⁢ ⁢ f ( 1 + α ) , ( 18 ) where α is the ratio of the guard time interval to the actual OFDM chip length T=1/Δf, while the nulls of the sinc(x)=sin(x)/x function are separated by f d =Δf. The ambiguities resulting from the use of the uniform pulse train are modified by the ambiguity of the single OFDM chip, which is a sinc function in the zero delay cut due to the use of completely random phases. The improvement is related to α, the ratio of the guard time interval to the actual OFDM chip length, through the equation A s , OFDM = | sin ⁢ ⁢ c ⁡ ( s ⁢ ⁢ π 1 + α ) | , ( 19 ) where A s,OFDM is the amplitude of the ambiguity corresponding to f d = ( s + 1 ) ⁢ Δ ⁢ ⁢ f ( 1 + α ) , s being a positive integer called the number of the ambiguity. The ambiguity occurs at each multiple of the pulse repetition frequency. The first ambiguity corresponds to s=1. While with no guard time interval the ambiguities seem to be eliminated, the carriers of the OFDM waveform are not orthogonal anymore in that case. The pulse compression scheme, which relies on the carriers' being orthogonal, does not work anymore. The Doppler compensation's acting as a filter provides a way of solving the ambiguity using one burst of pulses. As the pulse compression gain deteriorates with mismatched Doppler compensation, the ambiguous velocities requiring different Doppler compensation are separated from each other. Thus, the Doppler compensation provides a means to both improve the pulse compression by the compensation for the Doppler shift and solve the Doppler ambiguity in the final Doppler profiles resulting from the very low PRF. Further improvement of the range response is possible by the proper selection of the initial phases of the carriers instead of uniformly distributed random phases and by applying weighting on the carrier amplitudes. Initial phases can also be arranged so as to reduce the PAPR. The standard frequency tapering techniques can be applied as weighting of the carriers. Such tapering of the spectrum reduces the relative level of the range sidelobes. An example of such tapering techniques is Hamming window applied on the carriers. The Hamming weighting coefficients are generated through the equation A n = 0.54 - 0.46 ⁢ cos ⁡ ( 2 ⁢ π ⁢ ⁢ n N - 1 ) , ( 20 ) where n={0, 1, 2, . . . , N−1} is the carrier number and A n is the coefficient corresponding to the carrier n. Lower sidelobes are observed with widening of the main lobe of the zero Doppler delay cut of the ambiguity function, while the zero delay Doppler cut is not modified significantly. The maximum velocity that can be measured unambiguously by this processing technique corresponds to the Doppler frequency that is equal to the bandwidth of the transmitted OFDM signal, v u = f d ⁢ c 2 ⁢ f c = cN ⁢ ⁢ Δ ⁢ ⁢ f 2 ⁢ f c . ( 21 ) At this point the FFT coefficients are cyclically shifted by N to their original positions, which correspond to zero radial velocity. Following is an example of the OFDM waveform and the results of the processing according to an embodiment of the invention. The waveform parameters and the target parameters used in the example are given in the tables 1 and 2 below. The scenario for the example is given in FIG. 4 . TABLE 1 Waveform parameters Parameter Description Value N No of carriers 1024 M No of samples 4 * N = 4096 f c RF carrier 10 GHz Δf Carrier spacing 1 kHz R max Maximum range 37.5 km. T pulse Pulse period 1.25 ms. TABLE 2 Target parameters Parameter Description Value R 1 Target 1 range 4000 m R 2 Target 2 range 20000 m R 3 Target 3 range 20000 m v 1 Target 1 velocity 3 m/s v 2 Target 2 velocity −3 m/s v 3 Target 3 velocity 21 m/s The unambiguous Doppler defined for conventional pulse burst processing is given as v unam = ± ⁢ cf p 4 ⁢ f c , where f p is the pulse repetition frequency and f c is the high frequency carrier. For the continuous waveform including OFDM chips and cyclic prefix guard time intervals, the unambiguous Doppler is modified to v unam = ± c ⁢ ⁢ Δ ⁢ ⁢ f 4 ⁢ ⁢ f c ⁡ ( 1 + α ) , where Δf is the carrier spacing and α is the ratio of the length of the cyclic prefix to the actual chip length. For the numerical values given in Tables 1 and 2, the unambiguous velocity for the pulse burst Doppler processing is given as v unam = 3 × 10 8 × 10 3 4 × 10 10 × 1.25 = ± 6 ⁢ ⁢ ⁢ m ⁢ / ⁢ s . The unambiguous radial velocity for the single pulse Doppler processing is not defined, for the phenomenon observed in that processing technique is high sidelobes, which resemble the Sinc shape. The resolution is related to the time on target through the equation v res = c 2 ⁢ T dwell ⁢ f c For single pulse processing with the parameters as given above in Table 1, the radial velocity resolution is v res = 3 × 10 8 × 10 3 2 × 10 10 = 15 ⁢ ⁢ m ⁢ / ⁢ s and for pulse burst Doppler processing the radial velocity resolution is v res = 3 × 10 8 × 10 3 2 × 1.25 × K × 10 10 = 12 K ⁢ ⁢ m ⁢ / ⁢ s , where K is the number of pulses. The processing scheme as seen in FIG. 1 generates range profiles for each pulse and for different amounts of cyclic shift, denoted by Sfft. The process can be implemented such that the acquired data is arranged in a 3-D matrix structure, where each row holds the information for one pulse, each column corresponds to one range bin and each page corresponds to an Sfft value. Thus, the output of the FFT for each pulse is stored in the memory of the receiver; to be shifted cyclically and processed further to extract radial velocity information after all the pulses are received. The range profiles for the Doppler FFT outputs, corresponding to the velocities of the targets, are given in FIG. 5 . Summing the Doppler FFT outputs for all Sfft's that are searched generates the range profiles. The target ranges R 1 =4000 m and R 2 =R 3 =20000 m are visible in the range profiles. The cyclic shift by Sfft functions by decreasing the pulse compression gain for targets with radial velocities mismatched to the Sfft value. The absolute value of the outputs of the Doppler processing FFT along K=12 pulses for the range bin corresponding to R=20000 m are arranged to give the pulse compression gain behavior for the targets 2 and 3 for Sfft values in FIG. 6 . The figures are generated with 8 times over-sampling by the zero-padding block before the FFT. The views of FIG. 6 from different directions are given in FIG. 7 , FIG. 8 , and FIG. 9 for clarity. The contours in FIG. 7 show the two distinct peaks for the two targets at ambiguous velocities. The velocity ambiguity is evident from the peaks being located at v=−3 m/s, which can be observed in FIG. 9 , and the ambiguity is resolved in the Sfft axis due to the change in the pulse compression gain, as seen in FIG. 8 , where the sinc shaped pulse compression gain behavior is apparent. For this example, the maximum unambiguous velocity that can be measured is v u = ⁢ f d ⁢ c 2 ⁢ f c = ⁢ cN ⁢ ⁢ Δ ⁢ ⁢ f 2 ⁢ f c = ⁢ 3 × 10 8 × 10 3 × 1024 2 × 10 10 = ⁢ 15360 ⁢ ⁢ m ⁢ / ⁢ s , when the cyclic shift equals to the number of carriers and is equivalent to applying no cyclic shift.

An embodiment of the invention includes a step of transmitting an OFDM waveform including several frequency carrier signals transmitted simultaneously, the frequency carrier signals being coded in order to improve the Doppler response. An embodiment of the invention includes a step of receiving the echoed waveform from the target. The initial phase of each frequency carrier signal is recovered from the echoed waveform. The recovered initial phase of each frequency carrier signal is cyclically shifted in order to compensate for the Doppler effect and subsequently decoded. A compressed pulse is synthesized from the decoded initial phases.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to methods for treating pancreatic tumors. More particularly, the present invention is directed to methods for treating both benign and malignant pancreatic tumors with peptide YY and analogs thereof. 2. Description of Related Art Pancreatic tumors result in the death of more than 95 percent of afflicted patients. Isselbacher, et al. (ed.) Harrison's Principles of Internal Medicine, 1532-34 (13th ed., 1994). In 1993, approximately 25,000 patients died of pancreatic cancer, making it the fifth most common cause of cancer-related mortality. Cancer Facts and Figures, American Cancer Society (1993). Pancreatic tumors occur twice as frequently in the pancreatic head (60 percent of cases) as in the body (15-20 percent) or tail (about 5 percent) of the gland. Cotran, et at. (ed.) Rubbins Pathologic Basis of Disease, 988-992 (4th ed. 1989). Currently, complete surgical resection of pancreatic tumors offers the only effective treatment of this disease. Surgical resection, however, is limited, for all practical purposes, to those individuals having tumors in the pancreatic head and in whom jaundice was the initial symptom. Even with the operation, the five year survival rate for these patients is only five percent. Isselbacher, et al. (ed.) Harrison's Principles of Internal Medicine, 1532-34 (13th ed., 1994). SUMMARY OF THE INVENTION The present invention involves a method for treating pancreatic tumor cells to reduce the proliferation of such cells. The method is applicable to both benign and malignant tumors. In addition, the method is useful in both in vivo and in vitro environments. In accordance with the present invention, it was discovered that peptide YY is an effective anti-proliferation agent which, when contacted with pancreatic tumor cells, is useful in reducing the degree to which the tumor cells proliferate. As a further feature of the present invention, it was discovered that certain analogs of peptide YY are also effective anti-pancreatic tumor agents. The method includes the step of contacting the proliferating pancreatic tumor with an effective amount of peptide YY or an analog of peptide YY which are also referred to herein as peptide YY agonists. The contacting step can be carded out according to any of the known procedures for administering drugs to pancreatic tumors including parenteral delivery, e.g. administered to the tumor in a subject intravenously, subcutaneously, by implantation of a sustained release formulation (e.g. near the pancreas), transdermally (e.g. topically or by iontophoretic path), by implantable or external infusion pump, or by perfusion (e.g. of the pancreas). In other embodiments, the contacting step may also be effected externally or transmucously. The types of benign pancreatic tumor cells which may be treated in accordance with the present invention include serous cyst adenomas, microcystic tumors, and solid-cystic tumors. The method is also effective in reducing the proliferation of malignant pancreatic tumor cells such as carcinomas arising from the ducts, acini, or islets of the pancreas. Both definition and exemplification of peptide YY, and analogs of peptide YY, i.e. "peptide YY agonist" are set forth in the DESCRIPTION OF THE PREFERRED EMBODIMENTS below. It was discovered that dosage levels on the order of a few pmol/kg/hour were effective in reducing cell proliferation. Higher dosages ranging up to 1000 pmol/kg/hour and even higher may be used provided that side effects are not too adverse. The most common adverse side effect of administration of peptide YY and its analogs is vomiting. In general the amount of peptide YY or peptide YY analog required to achieve desired therapeutic effectiveness will depend upon the condition being treated, the route of administration chosen, and the specific activity of the compound used, and ultimately will be decided by the attending physician or veterinarian by routine dosage adjustments. Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof, and from the claims. Abbreviations: Aib=aminoisobutyric acid Anb=α-aminonormalbutyric acid Bip=4,4'-biphenylalanine Bth=3-benzothienyalanine Dip=2,2-diphenylalanine Nat=2-napthylalanine Orn=Ornithine Pcp=4-chlorophenylalanine Thi=2-thienylalanine Tic=tetrahydroisoquinoline-3-carboxylic acid DESCRIPTION OF THE PREFERRED EMBODIMENTS Peptide YY and Its Agonists: Peptide YY (PYY) is a 36 amino acid residue peptide amide isolated originally from porcine intestine and localized in the endocrine cells of the gastrointestinal tract and the pancreas (Tatemotu et al., 79 Proc. Natl. Acad. Sci. 2514 (1982)). The amino acid sequences of porcine and human PYY are as follows: porcine PYY--YPAKPEAPGEDASPEELSRYYASLRHYLNLVTRQRY (SEQ. ID. NO. 1) human PYY--YPIKPEAPGEDASPEELNRYYASLRHYLNLVTRQRY (SEQ. ID. NO. 2) The amino acid sequence for dog PYY and rat is the same as porcine PYY. PYY is believed to inhibit gut motility and blood flow (Laburthe, 1 Trends Endocrinol. Metab. 168 (1990)), to mediate intestinal secretion (Cox et at., 101 Br. J. Pharmacol. 247 (1990)); Playford et at., 335 Cancer 1555 (1990)), and stimulate net absorption (MacFayden et at., 7 Neuropeptides 219 (1986)). Novel analogs have been prepared in order to emulate and preferably enhance the duration of effect, biological activity, and selectivity of the natural peptide. Many of these analogs are derived from biologically active peptide fragments of PYY (e.g., PYY 22-36 and PYY 25-36 ). Such analogs, which inhibit the proliferation of pancreatic tumors, will be called peptide YY agonists herein. Peptide YY agonists which can be used to practice the therapeutic method of the present invention include, but are not limited to, those covered by the formulae or those specifically recited in the publications set forth below, all of which are hereby incorporated by reference. Balasubramaniam, et al., 1 Peptide Research 32 (1988); Japanese Patent Application 2,225,497 (1990); Balasubramaniam, et al., 14 Peptides 1011 (1993); Grandt, et at., 51 Reg. Peptides 151 (1994); and PCT U.S. application Ser. No. 94/03380 (1994). Peptide YY agonists which can be used to practice the therapeutic method of the present invention also include the closely related peptide neuropeptide Y (NPY) as well as derivatives, fragments, and analogs of NPY. The amino acid sequences of porcine and human NPY are as follows: human NPY--YPSKPDNPGEDAPAEDMARYYSALRHYINLITRQRY (SEQ. ID. NO. 3) porcine NPY--NPY YPSKPDNPGEDAPAEDLARYYSALRHYINLITRQRY (SEQ. NO. 4) The amino acid sequence for rat NPY, rabbit NPY, and guinea pig NPY are the same as human NPY. Examples of NPY analogs include but are not limited to, those covered by the formulae or those specifically recited in the publications set forth below, all of which are hereby incorporated by reference. German Patent Application DE 3811193A1 (1989); Balasubramaniam et al., 265 J. Biological Chem., 14724-14727 (1990); Cox et al., 101 Br. J. Pharmacol., 247-252 (1990); PCT Application WO 91/08223 (1991); U.S. Pat. No. 5,026,685 (1991); Balasubramaniam et al., 267 J. Biological Chem., 4680-4685 (1992); European Patent Application 0355793 A3 (1992); Dumont et al., 238 European J. Pharmacol., 37-45 (1993); Kirby et al., 36 J. Med. Chem., 3802-3808 (1993); PCT Application WO 94/00486 (1994); Fournier et al., 45 Molecular Pharmacol., 93-101 (1994). Balasubramaniam et al., 37 J. Med. Chem., 811-815 (1994); Polter et al., 267 European J. Pharmacol., 253-262 (1994); and U.S. Pat. No. 5,328,899 (1994). Preferred peptide YY agonists of the invention is of the formula: ##STR1## wherein: X is a chain of 0-5 amino acids, inclusive, the N-terminal one of which is bonded to R 1 and R 2 Y is a chain of 0-4 amino acids, inclusive, the C-terminal one of which is bonded to R 3 and R 4 R 1 is H, C 1 -C 2 alkyl (e.g., methyl), C 6 -C 18 aryl (e.g., phenyl, napthaleneacetyl), C 1 --C 12 acyl (e.g., formyl, acetyl, and myristoyl), C 7 -C 18 aralkyl (e.g., benzyl), or C 7 -C 18 alkaryl (e.g., p-methylphenyl); R 2 is H, C 1 -C 12 alkyl (e.g., methyl), C 6 -C 18 aryl (e.g., phenyl, naphthaleneacetyl), C 1 -C 12 acyl (e.g., formyl, acetyl, and myristoyl), C 7 -C 18 aralkyl (e.g., benzyl), or C 7 -C 18 alkaryl (e.g., p-methylphenyl); A 22 is an aromatic amino acid, Ala, Aib, Anb, N-Me-Ala, or is deleted; A 23 is Ser, Thr, Ala, N-Me-Ser, N-Me-Thr, N-Me-Ala, or is deleted; A 24 is Leu, lie, Vat, Trp, Gly, Aib, Anb, N-Me-Leu, or is deleted; A 25 is Arg, Lys, homo-Arg, diethyl-homo-Arg, Lys-ε-NH-R (where R is H, a branched or straight chain C 1 -C 10 alkyl group, or an aryl group), Orn, or is deleted; A 26 is His, Thr, 3-Me-His, 1-Me-His, β-pyrozolylalanine, N-Me-His, Arg, Lys, homo-Arg, diethyl-homo-Arg, Lys-ε-NH-R (where R is H, a branched or straight chain C 1 -C 10 alkyl group, or an aryl group), Orn, or is deleted; A 27 is an aromatic amino acid other than Tyr; A 28 is Leu, Ile, Vat, Trp, Aib, Aib, Anb, or N-Me-Leu; A 29 is Asn, Ala, Gln, Gly, Trp, or N-Me-Asn; A 30 is Leu, Ile, Val, Trp, Aib, Anb, or N-Me-Leu; A 31 is Vat, Ile, Trp, Aib, Anb, or N-Me-Val; A 32 is Thr, Ser, N-Me-Set, or N-Me-Thr; R 3 is H, C 1 -C 12 alkyl (e.g., methyl), C 6 -C 18 aryl (e.g., phenyl, naphthaleneacetyl), C 1 -C 12 acyl (e.g., formyl, acetyl, and myristoyl), C 7 -C 18 aralkyl (e.g., benzyl), or C 7 -C 18 alkaryl (e.g., p-methylphenyl); R 4 is H, C 1 -C 12 alkyl (e.g., methyl), C 6 -C 18 aryl (e.g., phenyl, naphthaleneacetyl), C 1 -C 12 acyl (e.g., formyl, acetyl, and myristoyl), C 7 -C 18 aralkyl (e.g., benzyl), or C 7 -C 18 alkaryl (e.g., p-methylphenyl), or a pharmaceutically acceptable salt thereof. Particularly preferred agonists of this formula to be used in the method of the invention include: N-α-Ala-Ser-Leu-Arg-His-Trp-Leu-Asn-Leu-Val-Thr-Arg-Gln-Arg-Tyr-NH.sub.2 (Analog #1) (SEQ. ID. NO. 5). Also preferred peptide YY agonists of the invention is of the formula: ##STR2## wherein: the N-terminal amino acid bonds to R 1 and R 2 ; Y is a chain of 0-4 amino acids, inclusive the C-terminal one of which bonds to R 3 and R 4 ; R 1 is H, C 1 -C 12 alkyl, C 6 -C 18 aryl, C 1 -C 12 acyl, C 7 -C 18 aralkyl, or C 7 -C 18 alkaryl; R 2 is H, C 1 -C 12 alkyl, C 6 -C 18 aryl, C 1 -C 12 acyl, C 7 -C 18 aralkyl, or C 7 -C 18 alkaryl; A 25 is Arg, Lys, homo-Arg, diethyl-homo-Arg, Lys-ε-NH-R (where R is H, a branched or straight chain C 1 -C 10 alkyl group, or an aryl group), Orn, or is deleted; A 26 is Ala, His, Thr, 3-Me-His, 1-Me-His, β-pyrozolylalanine, N-Me-His, Arg, Lys, homo-Arg, diethyl-homo-Arg, Lys-ε-NH-R (where R is H, a branched or straight chain C 1 -C 10 alkyl group, or an aryl group), Orn or is deleted; A 27 is an aromatic amino acid; A 28 is Leu, Ile, Val, Trp, Aib, Anb, or N-Me-Leu; A 29 is Asn, Ala, Gln, Gly, Trp, or N-Me-Asn; A 30 is Leu, Ile, Val, Trp, Aib, Anb, or N-Me-Leu; A 31 is Val, Ile, Trp, Aib, Anb, or N-Me-Val; A 32 is Thr, Set, N-Me-Set, or N-Me-Thr or D-Trp; R 3 is H, C 1-C 12 alkyl, C 6 -C 18 aryl, C 1 -C 12 acyl, C 7 -C 18 aralkyl, or C 7 -C 18 alkaryl; and R 4 is H, C 1 -C 12 alkyl, C 6 -C 18 aryl, C 1 -C 12 acyl, C 7 -C 18 aralkyl, or C 7 -C 18 alkaryl, or a pharmaceutically acceptable salt thereof. Note that, unless indicated otherwise, for all peptide YY agonists described herein, each amino acid residue, e.g., Leu and A 1 , represents the structure of NH--C(R)H--CO--, in which R is the side chain. Lines between amino acid residues represent peptide bonds which join the amino acids. Also, where the amino acid residue is optically active, it is the L-form configuration that is intended unless D-form is expressly designated. Synthesis of PYY Agonists: Human PYY, homologues, fragments, and analogs thereof, can be purchased commercially (Bachem California 1993-94 Catalogue, Torrance, Calif.; Sigma Peptides and Amino Acids 1994 Catalog, St. Louis, Miss.). The PYY analogs of the present invention may also be synthesized by many techniques that are known to those skilled in the peptide art. An excellent summary of the many techniques so available may be found in Solid Phase Peptide Synthesis 2nd ed. (Stewart, J. M. and Young, J. D., Pierce Chemical Company, Rockford, Ill. 1984). Analog #1 (Sequence ID No. 5), obtained from the University of Cincinnati, Cincinnati, Ohio, was synthesized as follows. Peptide synthesis was performed on an Applied Biosystems® (Forster City, Calif.) Model 430A synthesizer. Amino acid and sequence analyses were carried out using Waters® (Milford, Mass.) Pico-Tag and Applied Biosystems® Model 470A instruments, respectively. The peptide was purified using a Waters Model 600 solvent delivery system equipped with a Model 481 Spectrophotometer and U6K injector according to standard protocols. Peptide mass spectra were determined at the University of Michigan, Protein Chemistry Facility, An Arbor, Michigan according to standard methods. All Boc-L-amino acid derivatives, solvents, chemicals and the resins were obtained commercially and used without further purification. Paramethylbenzhydrylamine (MBHA) resin (0.45 mmol/gm, -NH 2 ) was placed in the reaction vessel of the peptide synthesizer and the protected amino acid derivatives were sequentially coupled using the program provided by the manufacturers modified to incorporate a double coupling procedure (see, e.g., Balasubramaniam et at., Peptide Research 1: 32, 1988). All amino acids were coupled using 2.2 equivalents of preformed symmetrical anhydrides. Arg, Gln and Asn, however, were coupled as preformed 1-hydroxybenzotriazole (HOBT) esters to avoid side reactions. At the end of the synthesis, the N-α-Boc group was removed and in some instances the free α-NH2 was acetylated by reaction with acetic anhydride (2 equivalents) and diisopropyl ethylamine until a negative ninhydrin test was obtained (Anal. Biochem. 34:595, 1970). The peptide resin (˜1.0 g) was then treated with HF (10 ml) containing p-cresol (˜0.8 g) for 1 h at -2 to -4° C. The HF was evaporated and the residue was transferred to a fritted filter funnel with diethyl ether, washed repeatedly with diethyl ether, extracted with acetic acid (2×15 ml) and lyophilized. The crude peptides thus obtained were purified by semipreparative RP-HPLC. Other PYY analogs of the invention can be prepared by making appropriate modifications, within the ability of a person of ordinary skill in this field, of the synthetic methods disclosed herein. While it is possible for peptide YY and peptide YY analogs to be administered as the pure or substantially pure compounds, it is preferable that they be administered as pharmaceutical formulations or preparation. The formulations to be used in the present invention, for both humans and animals, include peptide PYY any of the analogs set forth above, together with one or more pharmaceutically acceptable carriers therefor, and optionally other therapeutic ingredients. The carrier must be "acceptable" in the sense of being compatible with the active ingredient(s) of the formulation (and preferably, capable of stabilizing peptides) and not deleterious to the subject to be treated. The formulations may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy. All methods include the step of bringing the active ingredient(s) into association with the carrier which constitutes one or more accessory ingredients. In general, the formulations for tablets or powders are prepared by uniformly and intimately blending the active ingredient with finely divided solid carriers, and then, if necessary, as in the case of tablets, forming the product into the desired shape and size. Formulations suitable for intravenous administration, on the other hand, conveniently comprise sterile aqueous solutions of the active ingredient(s). Preferably, the solutions are isotonic with the blood of the subject to be treated. Such formulations may be conveniently prepared by dissolving solid active ingredient(s) in water to produce an aqueous solution, and rendering said solution sterile. The formulation may be presented in unit or multi-dose containers, for example, sealed ampules or vials. Formulations suitable for sustained release formulations include biodegradable polymers (e.g. U.S. Pat. Nos. 4,678,189 and 4,767,628, hereinafter incorporated by reference). Examples of suitable biodegradable polymers include L-lactic acid, D-lactic acid, DL-lactic acid, glycolide, glycolic acid, and any optically active isomers, racements, or copolymers thereof. Peptide YY and peptide YY agonists are administered to pancreatic tumors using the same procedures which are well-known for use in introducing chemotherapeutic agents to pancreatic tumors. The particular route of administration will vary depending upon tumor type, location, extent of growth and other factors. By routine experimentation, the preferred route of administration and dosage regimen can be established on an individual basis. As mentioned previously, the administration routes include: intravenous introduction to the tumor; subcutaneous introduction by implantation of a sustained release device near the tumor; transdermal introduction by topical or ion phoretic application; direct introduction to the tumor by an implantable or external infusion pump; or by perfusion. All of the above administration routes are well-known to those of ordinary skill in the art and have been used in pancreatic tumor treatment protocols using other chemotherapeutic agents. In order to achieve maximum dosage levels with minimum side-effects, it is preferred that administration techniques be used which introduce peptide YY or peptide YY agonists directly to the tumor. Direct infusion and perfusion are examples. The dosage level may be varied widely depending upon the patients tolerance to the particular peptide YY or analog being administered. Initial trial infusion or perfusion dosages on the order of two to four hundred pmol/kg/hour are preferably used. The dosage level is adjusted upward or downward depending upon patient tolerance and tumor response. Preferably the dosage level is increased to a level which provides a significant (i.e. at least 15 %) reduction in cell proliferation without causing adverse side effects, such as vomiting, abdominal pain or constipation. The method of the present invention is preferably carried out continuously over extended periods of time to achieve maximum effectiveness. Sustained release devices located adjacent to the tumor are well-suited for providing continual application. Infusion and perfusion is preferably carded out continually for 6 hours up to 168 hours. Patient and tumor response to the treatment is continually monitored during the treatment period with adjustments in dosage levels being made, if necessary. Treatment is terminated when desired levels of reduction in minor cell proliferation are achieved or the patient experiences adverse side effects. It is preferred that treatment times, like dosages, be maximized to achieve maximum reduction in cell proliferation without creating adverse side effects. Examples of practice are as follows: EXAMPLE 1 Demonstration of Anti-Proliferative Activity In Vitro In this example, the effectiveness of PYY and Analog #1 in reducing proliferation of two different pancreatic ductal adenocarcinomas in vitro is demonstrated. PANC-1 and MiaPaCa-2 are two human pancreatic adenocarcinomas cancer cell lines which are available commercially from suppliers such as American Type Culture Collection, ATCC (Rockville, Md.). For this example, the two tumor cells were grown in RPMI-1640 culture media supplemented with 10% fetal bovine serum, 29.2 mg/L of glutamine, 25 μg gentamicin, 5 ml penicillin, streptomycin, and fungizone solution (JRH Biosciences, Lenexa, Kans.) at 37° Celcius in a NAPCO water jacketed 5 % CO 2 incubator. All cell lines were detached with 0.25 % trypsin (Clonetics, San Diego, Calif.) once to twice a week when a confluent monolayer of tumor cells was achieved. Cells were pelleted for 7 minutes at 500 g in a refrigerated centrifuge at 4 ° Celcius, and resuspended in trypsin free fortified RPMI 1640 culture media. Viable cells were counted on a hemocytometer slide with trypan blue. Ten thousand, 20,000, 40,000 and 80,000 cells of each type were added to 96 well microculture plates (Costar, Cambridge, Mass.) in a total volume of 200 μl of culture media per well. Cells were allowed to adhere for 24 hours prior to addition of the PYY or Analog #1 peptides. Fresh culture media was exchanged prior to addition of peptides. In vitro incubation of pancreatic tumor cells with either PYY or Analog #1 was continued for 6 hours and 36 hours in length. PYY was added to cells at doses of 250 pmol, 25 pmol, and 2.5 pmol per well (N =14). Analog #1 was added to cells cultures at doses of 400 pmol, 40 pmol, and 4 pmol per well. Control wells received 2 μl of 0.9% saline to mimic the volume and physical disturbance upon adhered tumor cells. Each 96 well plate contained 18 control wells to allow for comparison within each plate during experimentation. Ninety-six (96) well plates were repeated 6 times with varying concentrations of PYY and Analog #1 in both the PANC-1 and MiaPaCa-2 cells. At the end of the incubation period, 3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium Bromide, MTr tetrazolium bromide (Sigma, St. Louis, Mo.) was added to fresh culture media at 0.5 mg/ml. Culture media was exchanged and tumor cells were incubated for 4 hours with MTT tetrazolium bromide at 37° Celcius. At the end of incubation, culture media was aspirated. Formazon crystal precipitates were dissolved in 200 μl of dimethyl sulfoxide (Sigma, St. Louis, Mo.). Quantitation of solubilized formazon was performed by obtaining absorption readings at 500 nm wavelength on an ELISA reader (Molecular Devices, Menlo Park, Calif.). The MTT assay measures mitochondrial NADH dependent dehydrogenase activity, and it has been among the most sensitive and reliable method to quantitative in vitro chemotherapy responses of tumor cells. (Alley, M. C., Scudiero, D. A., Monk, A., Hursey, M. L., Dzerwinski, M. J., Fine, D. L., Abbott, B. J., Mayo, J. G., Shoemaker, R. H. and Boyd, M. R., Feasibility of drug screening with panels of human tumor cell lines using a microculture tetrazolium assay Cancer Res., 48:589-601, 1988; Carmichael, J., DeGraff, W. G., Gazdar, A. F., Minna, J. D. and Mitchell, J. B., Evaluation of a tetrazolium-based semiautomated colorimetric assay: Assessment of chemosensitivity testing. Cancer Res., 47:936-942, 1987; McHale, A. P., McHale, L., Use of a tetrazolium based colorimetric assay in assessing photoradiation therapy in vitro. Cancer Lett., 41:315-321, 1988; and Saxton, R. E., Huang, M. Z., Plante D., Fetterman, H. F., Lufkin, R. B., Soudant, J., Castro, D. J., Laser and daunomycin chemophototherapy of human carcinoma cells. J. Clin. Laser Med. and Surg., 10(5):331-336, 1992.) Analysis of absorption readings at 550 nm were analyzed by grouping wells of the same test conditions and verifying differences occurring between control and the various peptide concentration treatments by one-way ANOVA. Once statistical significance was achieved, P <0.05, each test group was compared to its paired control group by Student's T-test within each 96 well plate. A statistical significance was considered when P <0.05 was achieved. The results of the MTT viability assays for PANC-1 and MiaPaCa-2 36 hours after exposure to either PYY or BIM-43004-1 are shown in the following Table. Percent reduction in cell growth is described as compared to control cell growth with normal saline inoculation. TABLE I______________________________________Percent Reduction in Tumor Growth(%)Compound Compared to ControlPEPTIDE CONCENTRATION PANC-1 Mia PaCa-2______________________________________PYY 250 pmol 25.7% 15.4%PYY 25 pmol 14.7% 12.8%PYY 2.5 pmol 9.8% 0.5%Analog #1 400 pmol 18.2% 37.1%Analog #1 40 pmol 21.3% 33.6%Analog #1 4 pmol 10.5% 28.3%*P < 0.05 by ANOVA______________________________________ As shown in the above Table, the MTT assay confirmed a significant decrease in the cell growth of both pancreatic tumor cell lines when PYY and Analog #1 were added to the cells. EXAMPLE 2 Demonstration of Anti-Proliferative Activity In Vivo In this example, the effectiveness of PYY and Analog #1 in reducing proliferation of a pancreatic ductal adenocarcinoma in vivo is demonstrated. The human pancreatic ductal adenocarcinoma Mia Paca-2 was examined for in vivo growth inhibition by peptide YY and Analog #1. Seventy thousand to 100,000 human Mia PaCa-2 cells were orthotopically transplanted into 48 male athymic mice. After one week, the animals were treated with either PYY or Analog #1 at 200 pmol/kg/hr via mini-osmotic pumps for four weeks. The paired cultures received saline. At sacrifice, both tumor size and mass were measured. Control mice had significant human cancer growth within the pancreas as evidenced by histologic sections. At 9 weeks, ninety percent (90%) of control mice had substantial metastatic disease. Tumor mass was decreased by 60.5 % in Analog #1 treated mice and 27% in PYY treated mice. EXAMPLE 3 Intravenous Treatment of Benign Pancreatic Tumor In Vivo A patient having a pancreatic serous cyst adenoma is treated as follows in accordance with the present invention: A sterile saline or distilled water solution containing from 7200 pmol to 864,000 pmol PYY or Analog gl in 1000 cc of total volume is administered intravenously to the patient at a rate of 12 to 24 ml/hour. The solution is administered so as to provide a delivery rate of PYY or Analog #1 on the order of about 200 pmol/kg/hour to about 400 pmol/kg/hour. The intravenous administration is conducted for 6 to 36 hours at a time depending upon patient tolerance. Standard intravenous delivery equipment is utilized. The treatment is repeated as required to achieve reduction in tumor cell proliferation. EXAMPLE 4 Perfusion Treatment of Benign Pancreatic Tumor In Vivo A patient having a pancreatic solid-cystic tumor is treated as follows in accordance with the present invention: A sterile saline or distilled water solution containing from PYY or Analog #1 is administered by directly perfusing the solution into the tumor site. The concentration of PYY or Analog #1 in the solution and the delivery rate are chosen to provide delivery of 200 pmol/kg/hour to 400 pmol/kg/hour. Perfusion is accomplished using Alzet Mini-Osmotic pumps implanted subcutaneously which are connected to a polyethylene catheter tunneled through the abdominal musculature. EXAMPLE 5 Implantation Treatment of Malignant Pancreatic Tumor In Vivo A patient having a carcinoma arising from a pancreatic duct is treated as follows in accordance with the present invention: An implant device is prepared which is capable of delivering from 100 pmol to 1000 pmol of PYY or Analog #1 directly to the tumor for periods of up to 2 weeks. The device is implanted adjacent to the tumor in accordance with standard implant insertion procedures. EXAMPLE 6 Intravenous Treatment of Malignant Pancreatic Tumor In Vivo A patient having a carcinoma arising from a pancreatic islet is treated as follows in accordance with the present invention: A sterile saline solution containing PYY or Analog #1 is administered intravenously to the patient via a peripheral venous catheter or central venous catheter. The delivery rate is selected so as to provide a dosage of from about 200 pmol/kg/hour to about 400 pmol/kg/hour of either PYY or Analog #1. EXAMPLE 7 Perfusion Treatment of Malignant Pancreatic Tumor In Vivo A patient having a carcinoma arising from a pancreatic acini is treated as follows in accordance with the present invention: A sterile saline solution containing PYY or Analog #1 is administered by directly perfusing the solution into the tumor site. The same perfusion procedure used in Example 4 is followed. The concentration of PYY or Analog #1 and perfusion rate are selected to provide delivery of 200 pmol/kg/hour to 404 pmol/kg/hour of either peptide YY or Analog #1. The publications and other reference materials referred to herein to describe the background of the invention and to provide additional details regarding its practice are all hereby incorporated by reference. The foregoing description has been limited to specific embodiments of this invention. It will be apparent, however, that variations and modifications may be made to the invention, with the attainment of some or all of the advantages of the invention. Such embodiments are also within the scope of the following claims. __________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 5(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 36 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(vi) ORIGINAL SOURCE:(A) ORGANISM: porcine peptide YY(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:TyrProAlaLysProGluAlaProGlyGluAspAlaSerProGluGlu151015LeuSerArgTyrTyrAlaSerLeuArgHisTyrLeuAsnLeuValThr202530ArgGlnArgTyr35(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 36 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(vi) ORIGINAL SOURCE:(A) ORGANISM: HUMAN PEPTIDE YY(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:TyrProIleLysProGluAlaProGlyGluAspAlaSerProGluGlu151015LeuAsnArgTyrTyrAlaSerLeuArgHisTyrLeuAsnLeuValThr202530ArgGlnArgTyr35(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 36 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(vi) ORIGINAL SOURCE:(A) ORGANISM: HUMAN NEUROPEPTIDE Y(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:TyrProSerLysProAspAsnProGlyGluAspAlaProAlaGluAsp151015MetAlaArgTyrTyrSerAlaLeuArgHisTyrIleAsnLeuIleThr202530ArgGlnArgTyr35(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 36 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(vi) ORIGINAL SOURCE:(A) ORGANISM: PORCINE NEURAL PEPTIDE Y(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:TyrProSerLysProAspAsnProGlyGluAspAlaProAlaGluAsp151015LeuAlaArgTyrTyrSerAlaLeuArgHisTyrIleAsnLeuIleThr202530ArgGlnArgTyr35(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 15 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(vi) ORIGINAL SOURCE:(A) ORGANISM: peptide YY analog #1(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:AlaSerLeuArgHisTrpLeuAsnLeuValThrArgGlnArgTyr151015__________________________________________________________________________

A method of inhibiting proliferation of pancreatic tumors. The method involves contacting the pancreatic tumor with an effective amount of peptide YY or an analog of peptide YY. The method may be used either in vitro or in vivo to reduce tumor cell proliferation. The method is also effective in treating both benign and malignant tumors.

FIELD OF THE INVENTION [0001] The present invention relates to methods for electrospinning fibrous biodegradable and/or bioabsorbable biomaterials and keratin membranes and scaffolds for medical applications. BACKGROUND [0002] The present invention is directed to products and methods having utility in medical applications. In one embodiment, the fibrous articles of the invention are polymeric membranes. [0003] Electrospinning is a simple and low cost electrostatic self-assembly method capable of fabricating a large variety of fibers approximately 40 nm to 2 μm in diameter, in linear, 2-D and 3-D architecture. Electrospinning techniques have been available since the 1930's (U.S. Pat. No. 1,975,504). In the electrospinning process, there is a high voltage electric field between oppositely charged polymer fluid contained in a glass syringe with a capillary tip and a metallic collection target. As the voltage is increased to a critical value, the charge overcomes the surface tension of the suspended polymer cone formed on the capillary tip of the syringe of the glass pipette and a jet of ultrafine fibers is produced. As the charged fibers are splayed, the solvent quickly evaporates and the fibers are accumulated randomly on the surface of the collection screen. This results in a nonwoven mesh of nano and micron scale fibers which has very large surface area to volume ratios and small pore sizes. Recently, electrospinning techniques have been developed and applied to the production of scaffolds in tissue engineering (Duan B, Yuan XY, et al. “A nanofibrous composite membrane of PLGA-chitosan/PVA was prepared by electrospinning”, European Polymer Journal 2006; 42: 2013-2022). [0004] In the present invention, electrospinning is used to produce fibrous composite from biomaterials and keratins for fabrication of membranes or scaffolds for medical applications. Examples of biodegradable and/or bioabsorbable biomaterials include, but are not limited to, poly(lactic acid), poly(glycolic acid), poly(lactic-co-glycolic acid). Food and Drug Administration (FDA) have approved these polymers for some human clinical applications, such as surgical sutures and implantable devices. One of their potential advantages is that their degradation rate can be adjusted to match the rate of regeneration of the new tissue. They can keep the framework until the new tissue forms because of their sufficient mechanical strength. They can also be fabricated to be the same complicated shapes or structures as the tissues or organs to be replaced. However, these are still some disadvantages, such as hydrophobicity, the lack of cell-recognition signals. These results that no sufficient cell attach on the surface of these polymer materials. The interaction between the host environment and these biomaterials still has much potential for improvement. Keratins are the major structure fibrous proteins constructing hair, wool, nail and so on, which are characteristically abundant in cysteine residues (7-20 number % of the total amino acid residues). As alternative natural proteinous biomaterials for collagen, wool keratins have been demonstrated to be useful for fibroblasts and osteoblasts, owing to their cell adhesion sequences, arginine-glycine-aspartic acid (RGD) and leucine-aspartic acid-vlaine (LDV), biocompatibility for modification targets. Moreover, they are biodegradable in vitro (by trypsin) and in vivo (by subcutaneous embedding in mice). Keratin sponges with controlled pore size and porosity was fabricated by a compression-modeling/particulate-leaching method. [0005] The fibrous composite of biopolymers and keratins could combine their advantages together and have potential medical applications. [0006] It is an object of the present invention to overcome the disadvantages and problems in the prior art. SUMMARY OF THE INVENTION [0007] The present invention uses electrospinning to prepare fibrous membranes and scaffolds of biodegradable and/or bioabsorbable biomaterials and keratin. BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIG. 1 is an SEM micrograph of PLLA electrospun membrane; [0009] FIG. 2 is an SEM micrograph of wool keratin particles; [0010] FIG. 3 is an SEM of electrospun PLLA/keratin fibrous membrane; [0011] FIG. 4 is an FTIR spectra of wool keratin; [0012] FIG. 5 is an FTIR spectra of fibrous PLLA membranes; [0013] FIG. 6 is an FTIR spectra of electrospun PLLA/keratin membrane; [0014] FIG. 7 shows the percentage change of keratin in PLLA/keratin; [0015] FIG. 8 shows XPS wide scan spectra; [0016] FIG. 9 shows the atomic change of the surface of PLLA/keratin membranes with degradation time; [0017] FIG. 10 is an SEM micrograph of osteoblasts on PLLA/keratin fibrous membrane; [0018] FIG. 11 is an SEM micrograph of osteoblasts on pure PLLA fibrous membrane. DESCRIPTION [0019] The present invention is directed to biodegradable and/or bioabsorable materials and keratin fibrous articles and cell culturing on these articles for medical applications. In one aspect, the invention relates to biodegradable and bioabsorbable fibrous articles formed by electrospinning of biodegradable and/or bioabsorbable materials. In another aspect, the articles contain composites of different biodegradable and/or bioabsorbable fibers. In yet another aspect, the articles can also include fibers of at least one biodegradable and/or bioabsorbable material which contains keratin. [0020] A biodegradable material is intended to be broken down (usually gradually) by the body of an animal, e.g. a mammal. A bioabsorable material is intended to be absorbed or resorbed by the body of an animal, such that it eventually becomes essentially non-detectable at the site of application. [0021] By the terminology “biodegradable and/or bioabsorable material” means that the material which is biocompatible, as well as biodegradable and/or bioabsorable, and capable of being formed into fibers. The material can be formed into a fibrous article which is suitable for medical application and capable of being biodegraded and/bioabsorbed by the animal. [0022] In a preferred embodiment, the biodegradable and/or bioabsorbable polymer was produced from a monomer selected from the group consisting of a glycolide, lactide, dioxanone, caprolactone, trimethylene carbonate, ethylene glycol, and lysine. The polymer can be a homopolymer, random or block co-polymer or hetero-polymer containing any combination of these monomers. The material can be a random copolymer, block copolymer or blend of homopolymers, copolymers, and/or heteropolymers that contain these monomers. [0023] In one embodiment, the biodegradable and/or bioabsorbable polymer contains bioabsorbable and biodegradable linear aliphatic polyesters such as poly(lactic acid) (PLA), poly(glycolic acid) (PGA) and their copolymer poly(glycolic-co-lactic acid)(PLGA). These polymers have been approved by FDA for use in surgical applications, including medical sutures. These synthetic absorbable materials have an advantage that is their degradability by simple hydrolysis of the ester backbone in aqueous environments. The final metabolin of these degradation products are carbon dioxide and water or can be excreted via the kidney. [0024] Some useful biodegradable and/or bioabsorbable polymers include poly(lactic acid), poly(glycolic acid), polycarprolactone, polydioxane, and their random and block copolymers. [0025] By the terminology “composite of different biodegradable and/or bioabsorbable fibers” means that a fibrous matrix contains different fibers interleaved with each other which can be in the form of a membrane or scaffold. [0026] By the terminology “different biodegradable and/or bioabsorbable fibers” means that the article contains fibers of different biodegradable and/or bioabsorbable materials, fibers of different diameters, or fibers of different biodegradable and/or bioabsorbable materials with different diameters. [0027] In one embodiment, the article contains different fibers having diameters in the range from a few nanometers up to 50 microns, more preferably about 50 nanometers up to about 20 microns and most preferably about 1 to about 10 microns. [0028] By the terminology “biodegradable and/or bioabsorbable material which contains keratin” is intended at least one of the biodegradable and/or bioabsorbable fibers in the article contains keratin. [0029] In one embodiment, the keratin particles were prepared from wool. The weight ratio of polymer and keratin is in the range of 0.1 to about 50, more preferably about 0.5 to 20. [0030] The membranes of the present invention may be employed as substrates for cell culture. Examples of uses of the membrane of the present invention include, but are not limited to, culturing osteoblasts. [0031] The polymer material for electrospinning is first dissolved in a solvent. The solvent can be any solvent which is capable of dissolving the polymer and providing a conducting fluid capable of being elecrospun. The solvent is preferably selected from tetrohydrofuran (THF), N—N-dimethyl acetamide (DMAc), N,N-Dimethyl formamide (DMF), chloroform, methylene chloride, dioxane, ethanol, or mixtures of these solvents. [0032] The concentration of polymer solution is in the range of about 0.1 to about 50 wt %, more preferably about 1 to about 10 wt %. The viscosity of the conducting fluid is in the range of about 50 to about 2000 mPas, more preferably about 200 to about 700 mPas. [0033] The range of electric field created in the electrospinning process is in a range of about 5 to about 100 kilovolts (kV), more preferably about 10 to about 50 kV. The feed rate of the conducting fluid to the spinneret will preferably be in the range of about 0.1 to about 500 ml/min, more preferably about 1 to about 100 microliters/min. EXAMPLES Example 1 [0034] A membrane was prepared as follows: a 1 wt % PLLA/chloroform/N,N-dimethyl formamide (DMF) solution was prepared by slowly dissolving PLLA pellets (inherent viscosity of 7.0 dl/g, PURAC, Netherlands) into a chloroform solvent at room temperature with stirring. After PLLA was completely dissolved, 10 wt % DMF was added. The solution was then loaded into the 20 ml syringe fitted with a needle, and delivered to an electrode. The solution was pumped and controlled by a syringe pump at a flow rate of 0.3 ml/min. A 10 kV positive high voltage was applied on the electrode. The distance from the tip of the electrode to the grounded collecting plate was 15 cm. A tiny electrospinning jet was formed and stabilized in 30 seconds under these conditions. The collecting plate was movable and controlled by a stepper motor. The collecting plate was continually moved at a rate of 1 mm/sec until a membrane having a relatively uniform thickness of about 100 microns was obtained. Electrospun membranes were sputtered with gold, and their morphology was observed under a scanning electron microscopy (SEM). [0035] The morphology of electrospun fibers is influenced by various parameters such as applied voltage, solution flow rate, distance between capillary and collector, and especially the properties of polymer solutions including concentration, surface tension and the nature of the solvent. A SEM image of PLLA membrane is shown in FIG. 1 . Example 2 [0036] A biodegradable and bioabsorbable membrane with keratin according to the present invention, fabricated by an electrospinning process, was prepared as follows: 1 wt % keratin powders ( FIG. 2 ) were dispersed in the PLLA/chloroform/DMF solution. The solution was then electrospun at 12 kV. The fibrous membrane was collected at 16 cm ( FIG. 3 ). The membrane was examined by FTIR and SEM. [0037] Except the parameters mentioned about, the concentration of keratin in the polymer solution also influences the fiber shape. The applied voltage, solution flow rate, distance between capillary and collector are adjusted accordingly. [0038] FIG. 4 is FTIR spectra of wool keratin. Wavenumbers from 3250 to 3300 cm −1 are the N—H stretch which is in resonance with amide II overtone. Wavenumbers at 1600-1700 cm −1 are mainly the C═O stretching. Wavenumber at 1550 cm −1 is the N—H bending coupled with C—N stretching. FTIR spectra of pure PLLA have no peaks from 1700 to 1500 cm −1 . For PLLA and keratin composite membrane, two peaks appeared at 1600-1700 cm −1 and 1550 cm −1 which belong to keratin. With increasing of keratin in the composite, these two peaks increase correspondingly ( FIG. 5 ). Example 3 [0039] PLLA/keratin (1:1) membranes were immersed phosphate buffer saline (PBS, pH 7.4) at 37° C. for various time periods up to 4 weeks. The degradation medium was changed daily for the first week, one at day 10 and day 14, and then weekly for the rest of the remaining period. Samples were taken out at the end of each sampling time point, i.e., at three hour, 1, 3, 7, 14, and 28 days. The samples removed from the PBS were first rinsed with distilled water and then vacuum dried for 24 h. PLLA/keratin samples before and after degradation were examine by Fourier transform infrared (FTIR) and X-ray photoelectron spectroscope (XPS) The characterizing peaks of PLLA and keratin were used to calculate their ratios after different degradation periods. Along with degradation period, the characterization peaks of keratin decreased correspondingly ( FIG. 6 ). According to the reducing of absorbance in FTIR spectra, the change of keratin in composite was calculated ( FIG. 7 ). In XPS wide scan spectra ( FIG. 8 ), it was found that (1) XPS spectra of pure PLLA showed only carbon and oxygen peaks, as expected; (2) a peak with binding energy at 400 eV corresponding to nitrogen (NIs) was detected. It is well known that it is characteristics amino acid residues in the keratin; (3) peaks corresponding to N appeared on the spectra of electrospun PLLA/keratin membrane; (4) the signals of nitrogen (N1s), the characteristics elements of keratin, were present in the spectra of PLLA/keratin composite after 3 hours degradation. [0040] The chemical compositions of the PLLA/keratin membranes after different degradation periods were calculated from the XPS survey scan spectra and showed in FIG. 9 . The nitrogen content of PLLA/keratin (8.9%) was lower than that of pure keratin (12.6%) because of zero nitrogen content in PLLA. At the first degradation stage, the N content decreased significantly. Along with degradation time, the content of N decreased because of the lost of keratin. After 28 days degradation, nevertheless 3% atomic of N was still detected which was contribute by keratin on the PLLA fibers. Example 4 [0041] MC3TS osteoblasts were cultured at 37° C. in a humidified atmosphere of 5% CO 2 in air, in flasks containing 6 ml Dulbecco's modified Eagle's medium (DMEM; Gibco), 10.0% fetal bovine serum (FBS; Gibco) and 1% penicillin/streptomycin. The medium was changed every third day. After 7-day culture, the MC3TS cells were removed from the flask, using trypsin, centrifuged, and resuspended in DMEM medium to adjust cell density to 4×10 6 cells/ml. 25 μl (about 1×10 5 cells) of the cell suspensions were seeded evenly into the PLLA/wool keratin (1:4 in weight) membranes with a micropipette. The seeded membranes were maintained in incubator for 2 h and culture medium was added to the wells. The medium was changed every 2 days. After incubation, any non-adherent cells on the samples were removed by aspirating the medium and washing with PBS solution. [0042] After 7 days of culture, cellular constructs were harvested, rinsed twice with PBS to remove non-adherent cells and subsequently fixed with 2.5% glutaraldehyde at 4° C. for 4 h. After that, the samples were dehydrated through a series of graded ethanol solutions and air-dried overnight. Dry cellular constructs were sputtered with gold and observed by SEM. [0043] SEM results showed that more cells were observed on PLLA/wool keratin membranes ( FIG. 10 ) than that on PLLA membrane control ( FIG. 11 ). [0044] Having described embodiments of the present system with reference to the accompanying drawings, it is to be understood that the present system is not limited to the precise embodiments, and that various changes and modifications may be effected therein by one having ordinary skill in the art without departing from the scope or spirit as defined in the appended claims. [0045] In interpreting the appended claims, it should be understood that: [0046] a) the word “comprising” does not exclude the presence of other elements or acts than those listed in the given claim; [0047] b) the word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements; [0048] c) any reference signs in the claims do not limit their scope; [0049] d) any of the disclosed devices or portions thereof may be combined together or separated into further portions unless specifically stated otherwise; and [0050] e) no specific sequence of acts or steps is intended to be required unless specifically indicated.

The present invention relates to a process of making biodegradable and/or bioabsorbable biomaterials and keratin nonwoven fibrous articles by electrospinning fibers from a blend of biomaterials and keratin dissolved in organic solvents includes generating a high voltage electric field between oppositely charged biomaterials and keratin fluid in a syringe with a capillary tip and a metallic collection roller and causing a jet to flow to the roller as solvent evaporates and collecting fibrous membranes or scaffolds on the roller. Keratin increased the cell affinity of biomaterial scaffolds which have potential medical applications.

BACKGROUND Present embodiments relate to a roll-up door. More specifically, present embodiments relate to a guard for a roll-up door which inhibits damage to the door or door shroud from objects passing through the doorway, such as fork lifts for example. Roll-up doors are utilized for a variety of functions. One usage is to allow passage through firewall openings within a building or warehouse. The roll-up door is opened during most usage but is lowered during fire conditions to inhibit spread of or contain a fire. However, during operation of a warehouse, for example, forklifts and hand trucks are used on a regular basis and pass through these openings in the firewall. Often the forks of the forklifts for example are in a raised condition when the vehicle is moving. During passage through openings, the forks, the load or otherwise elevated structure can impact the door or door shroud of the roll-up door assembly. This has two results. First, the shroud may be damaged, which may result in the roll-up door being inoperable. Second, if the impact is severe enough, the door may be damaged as well as the shroud. This will also adversely impact door operation. In either instance, the damage to the shroud or the door and shroud may preclude use of the door which presents an undesirable fire hazard. Specifically, the door cannot be closed in a fire condition which, as a result, allows the spread of fire through the building housing the roll-up door. As may be seen by the foregoing, there is a need to provide a structure for inhibiting damage to the door shroud and the roll-up door from equipment passing through the doorway. SUMMARY According to some embodiment, a roll-up door guard assembly comprises a first guard mount for positioning adjacent a first end of a roll-up door assembly and a second guard mount for positioning along a second end of said roll-up door assembly, a sleeve mounted to each of the first guard mount and the second guard mount, a bar extending between the first sleeve and the second sleeve, the bar capable of being positioned forward of the roll-up door assembly. The roll-up door guard assembly wherein the sleeves are formed to receive the bar. The roll-up door guard assembly wherein the sleeves are formed to be received by the bar. The roll-up door guard assembly wherein the sleeves are removably connected to the first and second guard mounts. The roll-up door guard assembly wherein the sleeves are integrally connected to the first and second guard mounts. The roll-up door guard assembly wherein the roll-up door guard is configured for connection to said roll-up door assembly. The roll-up door guard assembly wherein the roll-up door guard is configured for connection to a wall adjacent the door cover assembly. The roll-up door guard assembly wherein the bar is of a length equal to a distance between the first guard mount and the second guard mount. The roll up door guard assembly wherein the bar is welded to the first guard mount and said second guard mount. The roll-up door guard assembly wherein said bar is welded to the first sleeve and the second sleeve. The roll-up door guard assembly wherein the bar is of a length greater than a distance between the first sleeve and the second sleeve. The roll-up door guard assembly wherein the bar is captured between the first sleeve and the second sleeve. The roll-up door guard assembly further comprising a set screw connecting the bar to the first and second sleeves. The roll-up door guard assembly wherein the sleeves and the bar are square-shaped in cross-section. According to some other embodiments, a roll-up door guard assembly comprises a bar extending between a first sleeve and a second sleeve, a first guard mount at a first end of the bar and a second guard mount at a second end of the bar, the first sleeve extends from the first guard mount and the second sleeve extends from the second guard mount, the first and second guard mounts being connectable to a roll-up door assembly. The roll-up door guard assembly wherein the bar is hollow. The roll-up door guard assembly wherein the bar is disposed adjacent a storage area for a roll up door. The roll-up door guard assembly wherein the first sleeve and the second sleeve are L-shaped. The roll-up door guard assembly may be U-shaped. According to still other embodiments, a roll-up door guard assembly, comprises a first guard mount and a second guard mount capable of being mounted at ends of a roll-up door, a bar extending between the first guard mount and the second guard mount, the roll up door disposed between the bar and a wall to which the roll-up door is connected, the guard mounts connected to one of a wall and said roll-up door. The roll-up door guard assembly wherein the guard mount further comprises a sleeve. The roll-up door guard assembly wherein the bar is one of removably or fixedly connected to the sleeve. All of the above outlined features are to be understood as exemplary only and many more features and objectives of the roll-up door guard assembly may be gleaned from the disclosure herein. Therefore, no limiting interpretation of this summary is to be understood without further reading of the entire specification, claims, and drawings included herewith. BRIEF DESCRIPTION OF THE ILLUSTRATIONS The above-mentioned and other features and advantages of this disclosure, and the manner of attaining them, will become more apparent and the roll-up door guard will be better understood by reference to the following description of embodiments taken in conjunction with the accompanying drawings, wherein: FIG. 1 is an isometric view of the roll-up door at the doorway and a roll up door guard assembly. FIG. 2 is an isometric view of the roll-up door with the guard assembly exploded away. FIG. 3 is an isometric view of an exemplary roll-up door guard assembly. FIG. 4 is a top view of an exemplary door guard assembly. FIG. 5 is an alternate embodiment of a door guard assembly. DETAILED DESCRIPTION Reference now will be made in detail to embodiments provided, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation, not limitation of the disclosed embodiments. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present embodiments without departing from the scope or spirit of the disclosure. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to still yield further embodiments. Thus it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. Referring now to FIGS. 1-5 , a roll-up door guard assembly is depicted in various embodiments. The roll-up door guard assembly allows for positioning adjacent to a rollup door assembly such that when the roll-up door is in the up position allowing passage through the doorway, vehicles loading equipment or loads having a substantial height cannot directly contact the roll-up door assembly and cause damage to the door or shroud. Instead the guard receives the contact and precludes damage to the roll-up door which would otherwise occur without the door assembly. Referring now to FIG. 1 , a doorway 10 is depicted defined by a wall 12 having an opening 13 and a header 14 extending above the opening 13 . The doorway 10 has a first track 20 in a second track 22 adjacent the wall 12 along the opening 13 and extending vertically to guide roll up or down of a door 24 . A floor 16 is depicted below the header 14 and a threshold 18 is defined between the walls 12 and across the opening 13 wherein the door 24 may be seated when in the closed position. The door 24 is shown partly open, merely for illustration. One skilled in the art will understand that the door 24 will likely be in the fully open position when traffic, such as moving machinery is passing therethrough. In case of a fire, the door is closed to inhibit spread of fire through the building. Above the doorway 10 is a roll-up door assembly 30 . The door assembly 30 comprises a first door bracket 32 and a second door bracket 34 which provide two functions. First the brackets 32 , 34 allow connection of the roll-up assembly 30 to the wall 12 . Second, the brackets allow for rotation of the assembly allowing the door 24 to move up and down for opening and closing. The roll-up door assembly 30 further includes a door shroud cover 36 wherein the door 24 is housed when in the up or open position. The roll up door assembly 30 includes a pivot assembly 40 at each end of the assembly 30 which allows rotation of the door 24 during the roll up or roll down function to open or close the doorway 10 . The pivot assembly 40 may include a biasing structure which is not shown for clarity purpose but may include, for example, a coil or torsion spring to aid in lifting or lowering the door and controlling the weight thereof. Positioned in front of the door assembly 30 is a door guard assembly 50 . The guard assembly 50 is positioned in front of the roll up door assembly 30 in order to inhibit machines from damaging the door assembly 30 when passing through the doorway 10 . In use within a warehouse, or manufacturing facility, forklifts or other load movers tend to utilize structure which is moveable through a range of heights. As such mover or loading equipment raises the load or equipment, the may exceed the maximum height allowed for clearance by the roll-up door assembly 30 . When this occurs and the driver does not correct the situation, the equipment will strike the roll-up door assembly 30 . The result is that at a minimum that the cover 36 is dented. More typically though, the cover is damaged inhibiting operation of the door 24 or the strike is so severe as to damage the door 24 in addition to the cover 36 . The guard assembly 50 is positioned forward of the roll up door assembly 30 in order to protect from such damage. The guard assembly 50 receives the impact from the moving equipment passing through the doorway 10 rather than the roll-up door assembly 30 . This guard assembly 50 therefore will reduce repair and replacement costs for door assemblies 30 and related components. Referring now to FIG. 2 , an exploded view of the rollup door assembly 30 and the guard assembly 50 is depicted in isometric view. The guard assembly 50 includes a first mounting member 52 and a second mounting member 54 position for mounting at axial ends of the roll-up door assembly 30 . Each of the mounting members 52 , 54 have a first end which is mounted toward the wall 12 wherein the doorway 10 is positioned and a second end spaced away from the first end. The mounting members 52 , 54 may be of various shapes and may be formed of steel or other fire rated high strength materials which allow for mounting in a variety of ways. The mounting members 52 , 54 are shown as generally rectangular in shape, however the members 52 , 54 may vary in shape and may alternatively be formed of various materials. Connected to the first and second mounting members 52 , 54 are sleeves 56 , 58 . Each sleeve 56 , 58 has a first end spaced toward the corresponding mounting member 52 , 54 and a second end spaced away from the mounting member. The exemplary sleeves 56 , 58 in combination with the mounting member 52 , 54 form an L-shaped structure. However, such description should not be considered limiting, but instead merely exemplary. The sleeve 56 is shown with a square cross-section of may be any of various shapes which may or may not correspond to a bar structure 60 which, discussed further here in. According to some exemplary embodiments, the sleeve 56 , 58 is shown as receiving the bar 60 and therefore is at least partially hollow in shape. Alternatively, the sleeves 56 , 58 may be sized and configured so that the bar 60 receives the sleeves 56 , 58 opposite to the depicted embodiment. The combination of the mounting number 52 , 54 and each sleeve 56 , 58 forms an L-shaped according to the instant embodiment. However various configurations may be formed with this configuration. Additionally, the sleeves 56 and 58 may be permanently connected to mounting members such as by welding or integrally forming such as by molding or cast forms. In a further embodiment, the sleeves 56 , 58 may be removably attached to the mounting number 52 , 54 effectively. For example, a set screw 59 may be used retain bar 60 within sleeves 56 , 58 . Referring now to FIG. 3 , an exploded view of the sleeves 56 , 58 and bar 60 . The sleeves 56 , 58 receive the bar 60 at hollow ends of the sleeve 56 , 58 . As described previously, various shapes may be sued to form the sleeves 56 , 58 and the corresponding shape of the bar 60 . For example, circular bar stock may be used instead of the square bar. Additionally, the bar 60 may be hollow or may be solid. Weight requirements related to mounting as well as the width or span of the doorway 10 may dictate the type of bar 60 used and the size of sleeves 56 , 58 . According to some embodiments the bar 60 may be formed hollow and large enough to receive the sleeves 56 , 58 . Referring now to FIG. 4 , a top view of the guard assembly 50 is shown in the assembled configuration. According to one embodiment, the sleeves 56 , 58 are spaced apart a distance d 1 . The bar 60 is accordingly cut to a length d 2 which is either equal to or greater than the distance d 1 . The receiving ends of the sleeves 56 , 58 may be spaced apart a distance d 1 . The bar 60 is cut to a length equal to d 1 wherein the bar is welded to the sleeves 56 , 58 . In an alternative, the bar 60 is a length d 2 that is greater than the distance d 1 . In this embodiment, the bar 60 may be slidably positioned within the sleeves 56 , 58 or may be positioned exteriorly thereof. As shown in the depicted embodiment, the broken lines within the sleeves 56 , 58 show the oversized bar length. In this embodiment, the oversized length of the bar 60 results in capture of the bar 60 so that it cannot be removed when the mounting members 52 , 54 are fixedly mounted. In addition, for example, the bar 60 may or may not additionally be welded to the sleeves 56 , 58 . Alternatively, the bar may be locked by a set screw passing through sleeves 56 , 58 . Additionally shown in FIG. 4 , along the mounting members 52 , 54 are flanges 53 which may be used to connected the mounting members 52 , 54 to the roll-up door assembly 30 . The flange 53 may be positioned at any location along the members 52 , 54 . In the alternative, a fastener aperture 55 ( FIG. 2 ) may be disposed in the members 52 , 54 . This will allow for multiple mounting options to accommodate for various roll-up door assemblies. As shown in FIG. 5 , alternative mounting members 152 , 154 are shown. In this embodiment, flanges 53 are disposed at ends of the members in order to allow mounting of the members to a wall. This embodiment is used to connected the guard to a wall as opposed to or in addition to the roll-up door assembly. While multiple inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the invent of embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure. Examples are used to disclose the embodiments, including the best mode, and also to enable any person skilled in the art to practice the apparatus and/or method, including making and using any devices or systems and performing any incorporated methods. These examples are not intended to be exhaustive or to limit the disclosure to the precise steps and/or forms disclosed, and many modifications and variations are possible in light of the above teaching. Features described herein may be combined in any combination. Steps of a method described herein may be performed in any sequence that is physically possible. All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms. The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.” The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited. In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

A roll-up door guard assembly includes a first guard mount and a second guard mount capable of being mounted at ends of a roll-up door, a bar extending between the first guard mount and the second guard mount, the roll up door disposed between the bar and a wall to which said roll-up door is connected, the guard mounts connected to one of a wall and the roll-up door.

FIELD OF THE INVENTION The invention generally relates to a substantially seamless brassiere, and a blank and method for making the brassiere. More specifically, the invention relates to a substantially seamless criss-cross brassiere which can be readily and easily manufactured, to have a variety of visual appearances. BACKGROUND OF THE INVENTION Brassieres are generally designed to be close-fitting, and can represent a source of significant discomfort to the wearer. For example, in addition to being constrictive, the seams and narrow straps often forming a part of the brassieres can tend to press uncomfortably into the wearer's flesh, particularly after they have been worn for a length of time or when the wearer has been physically active. Because societal norms generally require that such garments should be worn, and many women must rely on them to provide a degree of support and coverage, the discomfort associated with them is typically viewed as something which must simply be tolerated. Furthermore, because the production of brassieres is generally a labor intensive process, their manufacturing costs can be relatively high. Therefore, manufacturers have attempted to find ways for simplifying the production of brassieres in order to reduce the costs associated therewith, in addition to looking for ways to improve wearer comfort. For example, commonly-assigned U.S. Pat. Nos. 5,479,791 and 5,553,468 to Osborne, the subject matter of which is incorporated herein by reference, describe circularly knit brassieres which, in addition to being capable of simplified manufacture, also provide enhanced wearer comfort. To this end, the brassieres described in the Osborne patents are each produced from a substantially seamless circularly knit tubular blank having a turned welt at one end thereof, with portions of the tubular portion of the blank being removed to define neck and arm openings, and the front and back sections of the tubular portions of the blank being sewn together at the shoulders. Banding is then provided at the neck and arm openings to form a finished brassiere. Another brassiere is described in U.S. Pat. No. 4,531,525 to Richards. The Richards patent describes a brassiere blank made on a circular knitting machine and having a torso portion with a pair of breast cups and straps knit integrally with the torso portion and having turned welt portions at each end of the cylindrical blank. The tubular blank is slit on one side, laid flat for cutting neck and arm openings, and seamed at each side to form a brassiere. The brassieres described in this patent therefore have side seams which can tend to cause discomfort to the wearer. SUMMARY OF THE INVENTION The instant invention provides a brassiere which has only a minimal number of seams, and which can be readily and easily manufactured. In addition, the instant invention enables the individual support of each of the breasts of the wearer, thereby providing unique comfort and support. Furthermore, the instant invention enables the provision of unique visual and aesthetic properties to the brassieres. Initially, it is to be noted that while the garment is referred throughout this application as being a “brassiere”, this term is meant in a broad sense to thereby encompass any type of relatively close-fitting upper torso covering garment. For example, the brassiere can be worn under other items of clothing in the form of an undergarment, as a camisole, athletic top, bathing suit top, dancewear, shirt, halter top, or the like. The instant invention desirably has a crisscross construction, and is capable of being produced without side seams (which might bear uncomfortably on the wearer). In fact, in one aspect of the invention, the brassiere has two shoulder straps (one for covering each of the respective shoulders of the wearer), and only a single seam is provided along each of the shoulder straps, thereby resulting in a substantially seamless brassiere. As will be discussed more fully below, the seams can be provided to correspond to the tops of the wearer's shoulders, or they can be offset from the tops of the wearer's shoulders (such as by making the front strap portions longer than the rear strap portions or vice versa), so that when the ends of the strap portions are joined together, the seams are offset from the tops of the wearer's shoulders and positioned forwardly or rearwardly thereof. The substantially seamless brassiere is achieved by way of the blank being circularly knit in a substantially continuous manner to include a first series of knit courses defining a first tubular portion, a second series of courses integrally knit with the first series of courses and forming a cylindrical tubular portion (e.g., in the form of a turned welt), and a third series of courses defining a second tubular portion knit to the second series of courses. The resulting blank is in the form of an elongate, generally continuous tubular structure having a cylindrical welt extending outwardly from a central portion of the tube to thereby encircle the tubular structure. Portions of each of the first tubular portion and the second tubular portion are then removed to define right and left body covering portions, and one of the right and left body covering portions is inverted so that each of the right and left body covering portions extends from the cylindrical welt in generally the same direction. In order to minimize material waste in these portions which are to be removed during transformation of the blank into a brassiere, the portions designed to be removed are, in some aspects of the invention, formed so as to require less material input. For example, the stitches in these areas can be lengthened to produce a meshy fabric in the areas which will become waste, a less expensive yarn could be used to knit those areas, etc. Edges of the right and left body portions are finished, to thereby form a brassiere. As mentioned above, in one form of the invention, the right and left body covering portions include both front and rear portions, with these front and rear portions being secured together to form shoulder straps for the brassiere. In another aspect of the invention, the right and left body covering portions could include front covering portions which are adapted to cover both of the wearer's breasts, and which are adapted to be secured together to form a generally halter-shaped structure. Also, it is to be noted that the steps of inverting and finishing of the edges of the right and left body covering portions can be performed in any order found to be efficient by the manufacturer, within the scope of the instant invention. The blank can also include regions which are knit differently from other regions, to form discrete regions with more or less stretch than other of the regions of the respective blank portion, to provide select regions of more or less support. Furthermore, the first tubular portion can be knit so as to be visually distinct from the second tubular portion, for example, by using yarns of different colors in each of the regions, knitting in a visual pattern in one of the tubular portions, varying the knit stitch pattern or the like, etc., such that one breast cup of the brassiere has a different visual appearance from the other breast cup. Also, plating of the yarns could be used to provide different visual characteristics to each of the respective first and second tubular portions, whereby brassieres can be produced having different visual characteristics on each of the right and left sides. For example, one tubular portion could be knit to have stripes, while the other is knit as a solid color, to thereby produce a brassiere having a striped first breast covering side and a solid second breast covering side. As a further alternative, a spandex yarn could be plated while knitting the first and second tubular portions, such that when one of the portions is inverted to form the finished brassiere, one side has a shimmery effect due to the spandex appearing on the outer fabric surface of that side of the brassiere. As illustrated, because of the construction and manufacturing process forming a part of the instant invention, the provision of unique aesthetic appearances is enabled, while also providing a brassiere having the comfort of a generally seamless brassiere. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a blank made according to the instant invention; FIG. 2 is a cross-sectional view taken along the line 2 — 2 of FIG. 1, illustrating the manner in which the welt is secured to the first and second tubular portions; FIG. 3 is a perspective view of the blank shown in FIG. 1, illustrating the lines along which the blank can be cut to form one embodiment of the invention; FIG. 4 is a perspective view of the blank shown in FIG. 3 after it has been cut along the lines shown in FIG. 3, and showing where banding can be added to finish the edges; FIG. 5 is a perspective view illustrating how the blank shown in FIG. 4 can be inverted and the front and rear portions seamed together; and FIG. 6 is a perspective view of a finished brassiere according to the invention. DETAILED DESCRIPTION OF THE INVENTION The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. With reference to the drawings, FIG. 1 illustrates a blank, shown generally at 10 , formed according to the instant invention. The blank 10 is desirably circularly knit to include a first tubular portion 12 having a first length a. A tubular, cylindrical welt 14 is integrally knit to the first tubular portion 12 so that it extends outwardly from the first tubular portion a distance b. In a preferred form of the invention, the tubular, cylindrical welt 14 will be in the form of a turned welt, such terminology being known to those having ordinary skill in the art. Such welts are generally formed by holding a set up course, drawing the fabric away until a sufficient length has been knit to form the double-thickness welt, then transferring the held course back onto the needles so that it is knit into the structure. A second tubular portion 16 is integrally knit to the tubular, cylindrical welt 14 . This second tubular portion 16 has a second length c. In many embodiments of the invention, this length c of the second tubular portion 16 will be approximately equal to the length a of the first tubular portion 12 . Each of the tubular portions 12 , 16 and the tubular cylindrical portion 14 desirably has a circumference which is sized to correspond with the size of the wearer who is expected to wear a brassiere made from the particular blank. In other words, the tubular circumference of the blank will generally be on the order of the same size as the circumference of a torso of a wearer for whom a brassiere is designed to fit, or somewhat smaller than the intended wearer's torso such that when the knit fabric gives through its natural extensibility, it provides a close fit about the wearer. For example, some extensibility may be provided through the particular knit stitch construction used, while stretch may also be provided by way of the incorporation of stretch yarns in the fabric, in addition to or instead of the stretch provided through the knit structure itself. Furthermore, it is noted that the amount of stretch can be varied at discrete points throughout the dimension of the tubular portions 12 , 16 and the cylindrical tubular portion 14 , for either aesthetic purposes or to vary the physical characteristics thereof. For example, it may be desirable to knit-in regions of less stretch to provide supplemental support regions on the finished brassiere, etc. As illustrated more clearly in FIG. 2, which is a cross-section taken along lines 2 — 2 of FIG. 1, the cylindrical welt 14 extends outwardly from the first and second tubular portions 12 , 16 , thereby defining a length b (with the actual length of fabric forming the welt being about two times length b). It is noted that the knit stitches illustrated have been simplified for purposes of clearly illustrating that the tubular, cylindrical welt 14 is formed by way of knit stitches and integrally formed with the first and second tubular portions 12 , 16 by way of the knitting process. Other knit fabric and stitch structures can be utilized within the scope of the instant invention. In fact, it is desirable that this tubular, cylindrical welt portion 14 is fashioned so as to be more resistant to stretch than the tubular portions 12 , 16 , since the welt portion 14 will form the lower band portion of the finished brassiere once it is fashioned from the blank 10 . The resistance to stretch can be done through alteration of the knit stitch construction, the feeding or floating in of additional stretch yarn(s) such as those made from spandex, natural rubber, or the like, or other methods conventionally known in the art for varying the stretch of knit fabrics. As noted above, the first tubular portion 12 and second tubular portion 16 desirably have lengths a and c which are substantially equal to each other in length. In this way, when a brassiere is cut from the blank 10 , it is relatively easy to ensure that the right and left portions of the brassiere are similarly sized, and that waste is minimized. As illustrated in FIG. 3, the tubular blank is desirably cut along lines 22 a , 22 b , 24 a , 24 b along first tubular portion 12 with portions 30 , 32 being removed as waste. Similarly, second tubular portion 16 of the blank 10 is cut along lines 26 a , 28 a , and in corresponding mirror image on the rear side of the tubular blank in the same manner as with the first tubular portion 12 . Following cutting, pieces 34 , 36 of the second tubular portion 16 are removed as waste. The cut edges formed at 22 a and 22 b will form one arm opening on one side of a finished brassiere, while the cut edges formed at 24 a and 24 b will form a portion of a neck opening on the finished brassiere. Likewise, the cut edge formed at 26 a and its corresponding edge on the rear side of the blank will form a second arm opening in the finished blank, while the cut edge formed at 28 a and the corresponding one on the rear of the blank will define a portion of a neck opening of the brassiere. As shown more clearly in FIG. 4, the remaining portions of the blank can then be finished to form a completed brassiere. In particular, the blank now defines a front right strap portion 40 and a rear right strap portion 42 formed from first tubular portion 12 while corresponding left front strap portion 44 and left rear strap portion 46 are formed from second tubular portion 16 . It is noted that in order to minimize waste, the portions 30 , 32 , 34 , 36 which are designed to be removed during the transformation of the blank into a brassiere, can be formed so as to include less yarn than the portions of the blank which will remain to form portions of the brassiere. For example, methods such as lengthening the stitches, using different-sized or less expensive yarns to form these waste portions, or the like (e.g. lessening the waste material in a manner like that described in the aforementioned U.S. Pat. Nos. 5,479,791 and 5,553,468) will desirably be utilized. The front and rear right strap portions 40 , 42 are then sewn or otherwise secured together, as shown at 66 , for example, so as to form a shoulder strap 60 . Likewise, the left front and rear strap portions 44 , 46 are sewn together to form a left shoulder strap 62 . In the illustrated embodiment, the front and rear right strap portions 40 , 42 , and likewise the front and rear left strap portions 44 , 46 are illustrated as being substantially the same size. Therefore, when the ends of the strap forming portions remote from the cylindrical welt 14 are sewn together, it results that the seam 66 formed by the securement of the straps together is positioned generally on top of a wearer's shoulder in the finished article. However, it is noted that the strap forming portions could be secured together at other portions such that the seam is offset from the top portion of the wearer's shoulder. Furthermore, they can be secured together in a releasable fashion as opposed to a more permanent fashion such as sewing. However, in the preferred embodiment of the invention, the front and rear right strap forming portions are sewn together at their respective strap forming portion ends and the left strap forming portions are sewn together in like manner. The cut edges of the blank are then finished, preferably by sewing elastic banding to each of the cut regions, i.e., along cut region 50 (formed by cutting along lines 22 a and 22 b ) to form a right arm hole 68 and along line 52 (formed by cutting along lines 26 a and the corresponding line on the rear of the blank) to form a left arm hole 69 and along line 54 (formed by cutting along lines 24 a and 24 b ) to form the edge of the right strap portion and a portion of neck opening 72 , and along line 56 (formed by cutting along line 28 a and the corresponding line on the rear of the blank) to form the edge of the left strap portion and a portion of neck opening 72 . It is to be noted that the order in which the finishing steps are performed is a matter of manufacturing choice: for example, the strap forming portions can be secured together, then the banding added, or the banding can be secured to the cut edges first, and then the strap-forming portions secured together. Furthermore, the inverting step (discussed more specifically below) can be performed at any point during the process, the order being determined according to which achieves the most optimal manufacturing efficiencies for the particular manufacturer. One of the strap forming portions is inverted so that both straps extend upward from the turned welt 14 in the same direction in the manner shown in FIGS. 5 and 6. For example, in FIGS. 5, the left strap portion 62 is shown being inserted through the center of the tubular cylindrical welt 14 so that the right and left strap forming portions 60 , 62 , respectively are extending away from the tubular cylindrical welt in the same direction. The finished brassiere 70 provides individual breast support for the wearer, and is readily and easily manufactured. Furthermore, as illustrated in FIG. 6, because of the criss-cross construction, in some embodiments of the invention the left portion of the brassiere can be shaped so that it crosses to provide under-breast support for the wearer's right breast, and the right portion of the brassiere can be likewise shaped so that it crosses to provide under-breast support for the wearer's left breast. In the shoulder strap version of the invention, the brassiere 70 desirably includes a right strap 60 , a left strap 62 , a right arm opening 68 , a left arm opening 69 , and a neck opening 72 . Alternatively, the right and left front portions could be tied or otherwise operatively secured together to form a halter-shaped brassiere. In one aspect of the invention, the first tubular portion 12 and second tubular portion 16 are formed from different colored yarns. In this way, when the finished brassiere is completed, one of the strap portions and breast cups has a first visual appearance while the other has a second distinct visual appearance. For example, yarns can be plated (e.g. with spandex appearing on one fabric surface) so that when one portion of the blank is inverted, the resulting garment has one side with a visually distinct appearance from the other (e.g. the spandex provides a more shimmery appearance.) Similarly, one side (e.g. the right side) can be knit to have polka dots or stripes, while the other side (e.g. the left side) is knit from a solid color. As will be appreciated by those of ordinary skill in the art, various other combinations of visual colors, patterns, etc. can be used within the scope of the instant invention. As a result, a virtually limitless range of visual appearances can readily and easily be provided to the brassiere. Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

A brassiere having a minimal number of seams and allowing for independent breast support is described. The brassiere is produced from a circularly knit blank having a first tubular portion, and integrally knit cylindrical tubular welt portion, and an integrally knit second tubular portion. Portions of each of the first and second tubular portions are cut and removed to define right and left front portions, and the remaining portion of one of the first or second tubular portions is inverted so that the remaining parts of each of the first and second tubular portions extend away from the welt portion in generally the same direction. Banding can be attached to form neck and arm openings, and, where applicable, the front and rear strap portions can be secured together, thereby forming a finished brassiere. In this way, substantially seamless brassieres having right and left breast covering portions made to have visually distinct appearances can be readily and easily produced.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the stabilization of pyrolysis gasoline (“pygas”), and more particularly to the first stage hydrogenation of pygas. 2. Description of the Prior Art Crude oil fractions such as a straight run naphtha from a crude oil still are conventionally steam cracked in an olefins unit to produce light olefins and aromatics, valuable chemicals in their own right. Pygas is a valuable by-product of such steam cracking because it is generally high octane and within the general gasoline boiling range of from about 100 to about 435° F., and can be used as a finished gasoline blending stream after undergoing certain processing before blending. Because pygas is derived from steam cracking complex hydrocarbon streams such as naphthas, it can carry with it a large amount of widely varying catalyst poisons that interfere with the aforesaid pre-blending processing of pygas. The amount and severity of pygas poisons is unusually severe as compared to other gasoline producing streams, e.g., gasolines from catalytic cracking units. This makes pygas pre-blending processing quite detrimental to catalyst life during such processing. Also unlike other gasoline streams used for finished gasoline blending, pygas, before first stage hydrotreating contains substantial amounts of gum precursors, and has poor oxidation stability. Accordingly, pygas is challenging to stabilize and otherwise process before gasoline blending is undertaken. The first stage of pygas processing before blending is often hydrotreating over a Group VIII metal catalyst (iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum) to selectively hydrogenate gum precursors such as diolefins, acetylenics, styrenics, dicyclopentadiene, and the like while not hydrogenating significant amounts of mono-olefins, aromatics, and other gasoline octane enhancers. Competitive adsorption causes diolefins and acetylenics to be hydrogenated preferentially over mono-olefins and aromatics thus removing gum tendencies while maintaining octane value. Paraffins are left unchanged or mildly isomerized which can help gasoline value. Sometimes several stages of selective hydrogenation are carried out. Second stage hydrotreating is often done on a BTX (benzene, toluene, and xylenes) fraction of pygas for removal of sulfur and other impurities. The poison severity usually found in pygas can severely reduce first stage hydrogenation catalyst activity and catalyst life. For example, while sulfur, carbonyls, basic nitrogen, and gums/coking tend to be temporary catalyst poisons, arsenic, mercury, lead, and phosphorous tend to be more permanent poisons. Other permanent poisons include trace silicon oxide and corrosion metal oxide dusts which tend to plug catalyst pores. Also polysiloxanes thermally decompose and permanently poison palladium or nickel catalysts. Guard beds can be employed upstream of a first stage hydrotreater to remove such poisons, but this is an expensive approach, and it is not always physically possible or otherwise practical to install guard beds and regeneration capability. Thus, it is very desirable to have a pygas first stage hydrogenation catalyst that remains robust as to both selective hydrogenation activity and catalyst life when exposed to the pygas poison severity without resorting to a guard bed or other processing to remove or neutralize poisons before such first stage hydrotreating. Group I B metals (gold, silver, and copper) have heretofore been used as a catalyst for the selective hydrogenation of unsaturates, see U.S. Pat. No. 5,068,477 to Berrbi. Berrbi's patent does not suggest directly or indirectly the use of promoters to make a pygas first stage hydrogenation Group VIII metal catalyst more robust to poisons carried in the pygas. Group I B metals have also been suggested to be used with Group VIII metal on a support of silicon dioxide to remove alkynes, dienes and mono-olefins from olefin streams for polymerization over a metallocene catalyst or from pyrolysis gases produced in plastic recycling plants, see U.S. Pat. No. 6,204,218 to Flick et al. This patent also does not relate to the rendering of pygas hydrotreating catalyst more robust by the use of promoters. European Patent No. EP O 738 540 Al to Zisman et at. discloses a method for the selective hydrogenation of acetylene in the gas phase using a catalyst containing alkali metal, chemically bound fluorine, and a support. Zisman et al. disclose that when the atomic ratio of fluorine to alkali metal is in (the range of 1.3:1 to 4:1 the catalyst is more resistant to deactivation to sulfur impurities. Zisman et al. optionally include silver in their catalyst but not as a promoter against sulfur poisons since Zisman et al. achieve their desired protection against sulfur deactivation when silver is not present in their catalyst. U.S. Pat. No. 4,404,124 to Johnson et al. also discloses a method for the selective hydrogenation of acetylene in the gas phase using a catalyst containing palladium, silver, and alumina. Johnson et al. disclose that a high loading of the catalyst “is expected” to make the catalyst less sensitive to arsenic in the gaseous feed. Thus, Zisman et al. and Johnson et al. 1) teach the use of silver as an active catalytic part of a catalyst for the selective hydrogenation of gaseous acetylene; 2) lead away from the use of silver as a promoter for sulfur poisons; and 3) only speculate as to the effect of silver high loading in respect of arsenic in the context of an acetylene selective hydrogenation catalyst. Further, neither of these patents suggest directly or indirectly the use of promoters to make a hydrogenation catalyst for normally liquid pygas more robust in the presence of the wide variety of poisons (which include sulfur poisons) normally found in a pygas feed. DETAILED DESCRIPTION OF THE INVENTION In accordance with this invention, conventional first stage pygas hydrotreating Group VIII metal catalyst is rendered more robust to the severity of poisons carried by pygas by employing said Group VIII metal on an alumina based support and adding to said catalyst at least one promoter selected from metals of Group I B (silver, gold, copper), zinc, Group VI B (chromium, molybdenum, tungsten), manganese, rhenium and/or oxides thereof. Presently preferred promoters are silver, gold, copper, and manganese in their reduced (elemental) state with the remainder of the materials being in an oxidized state. More preferred promoters include silver, gold, zinc, chromium, molybdenum, manganese, and copper. Of these preferred promoters, zinc, chromium, and molybdenum will be in the oxide form, and the others in the reduced state. The promoter or combination of promoters is employed in an amount effective preferentially to trap at least one poison in said pygas and thereby separate same from said pygas before said poison reaches an active Group VIII metal site thereby leaving said Group VIII metal site active and available for said selective hydrogenation. Accordingly, the amount of promoter or promoters used can vary widely based on the amount, nature, and variety of poisons carried in the particular pygas being treated, but will generally be from about 0.01 to about 40, preferably from about 0.3 to about 15.0, weight percent based on the total weight of the catalyst. The alumina based support of this invention is at least one of the group comprising alumina, deactivated alumina, amorphous silica-alumina, and crystalline silica aluminate. Silica by itself is not useful, contrary to Flick et al. cited hereinabove. Preferably all supports employed in this invention have slight or no acidity as measured by the conventional ammonia adsorption test, see Journal of Catalysis, Volume 2, pages 211-222, 1963. Still more preferably the support(s) has a Hammett function, H 0 in the range of −3.0 to 5.0 where H 0 =−log[a H *f B /f HB ]. a H is defined as proton activity of the support and f B , f HB are activity coefficients of the basic and acid forms of the support. The catalyst for the promoter can be employed on the surface of the support, in the interior pores of the support, or a combination of both. Although some of the metals set forth above as promoters have been used as catalysts heretofore, they are not employed in a manner to serve as catalysts in this invention. Rather they are employed to serve as a promoter to maintain the Group VIII metal active to serve as the catalyst in the process of this invention. For example, when palladium is used in a catalyst according to this invention, it provides the active catalyst sites for the desired selective hydrogenation diolefins and acetylenics in the pygas. If silver was used as the promoter on a palladium catalyst, the silver would be many orders lower in activity as a catalyst than palladium or nickel and would serve primarily as a poison trap rather than as a catalyst. Similarly, if hydrogen sulfide (H 2 S) is a prevalent poison in a particular pygas, zinc is an especially efficient H 2 S getter (adsorbent) and could, pursuant to the inventive concept of this invention, be employed as a promoter along with silver, or in lieu of silver, on, for example, a palladium/alumina catalyst used in the first stage hydrotreating of that particular pygas. Also, silver or gold promoted palladium is particularly selective for the hydrogenation of acetylinics to their corresponding olefin. The catalyst of this invention can be made in any conventional manner well known in the art. One such preparation method is the well known “incipient wetness” process wherein, for example, a salt of the catalyst metal in an aqueous solution is applied on an alumina support form such as an extrudate. The catalyst metal impregnated wet extrudate is dried, leaving catalytically active metal on the extrudate. The dried catalyst is then calcined. The active metals in the catalyst need to be reduced to their metallic state and in the case of nickel be partially sulfided in order to get the catalyst into the desired state for use in the pygas hydrotreating/stabilizing operation. The support impregnation process can be repeated as desired to add additional catalyst metals or promoters to the support. The same process steps are used to add one or more promoters of this invention to the same support. For more information for the preparation of catalysts, see Catalyst Manufacture, Chemical Industries, Volume 14, published by Marcel Dekker (1983). The feed material for this invention is any liquid phase pygas stream, whether full range or a fraction thereof, formed from any hydrocarbon steam cracking process. Such pygas feeds can have a wide variety of poisons and in varying amounts. Generally, they will have from about 30 ppb to about 500 ppm cumulative of a variety of catalyst poisons such as mercury, arsenic, lead, alkalai metal, phosphorus, silicon, iron oxide containing rouge dust (stainless steel corrosion products such as chromium oxide, nickel oxide and the like), sulfur, coke, halides (metal, particularly alkali and alkaline earth metal, chlorides, bromides and fluorides), siloxanes, sulfur containing compounds, nitrogen containing compounds, silica, carbonyls, and mixtures of two or more thereof. Mercury, arsenic, alkali metals, phosphorus, lead, iron oxide, sulfur, hydrogen sulfide, ammonia, and siloxanes are often present together in the same pygas fuel. The particular combination of catalyst metal(s) and promoter(s) will vary widely as will the amounts of each employed on a single support depending on the hydrogenation selectivity desired and the variety and amount of poisons in the pygas feed. For example, palladium tends to be more selective for gum precursor hydrogenation and loses less octane in so doing, but it is quite vulnerable to poisons. It can be promoted with gold and/or silver to be more selective for acetylene hydrogenation and at the same time with zinc oxide if H 2 S is a particularly prevalent poison. The less acidic alumina supports of this invention reduce undesirable oligomerization reactions that lead to gums and coke fouling. Also adding to the challenge of promoting the catalyst is that some of the poisons tend to be temporary while others tend to have a permanent poisoning effect. Temporary poisons include sulfur, carbonyls, and basic nitrogen. More permanent poisons include caustic, arsenic, mercury, lead, chlorides, phosphorous, transition metals from corrosion dust (Fe, Ni, Mn, Cr). Trace amounts of silicon as siloxanes from their use upstream as emulsion breakers can permanently poison palladium and nickel hydrogenation catalysts. Siloxanes (—O—Si(R 2 )—O—Si(R 2 )—O—), can be straight-chain or cyclic, e.g., hexamethylcyclotrisiloxane and octamethyl-cyclotetrasiloxane. Also the tolerance of various catalyst metals to different poisons varies considerably. For example, in comparing a palladium based catalyst and a sulfided nickel based catalyst, the tolerances are (1) for siloxane, 500 ppm on 0.3 weight (wt.) % palladium versus several wt. % silicon on 12-18 wt. % NiS; (2) for arsenic and mercury, 6,000 ppm on 0.3 wt. % palladium to end of life versus 10 to 100 times more tolerance for nickel; (3) for H 2 S, temporary poison for palladium but permanent for NiS; for basic nitrogen (ammonia), 1 to 100 ppm is a temporary poison to both palladium and NiS; and (4) phosphorus and sodium tend to be permanent poisons for both catalysts. Accordingly, it is most difficult, if not impossible, to define the amount of each promoter used with a given catalyst for a particular pygas composition, but one skilled in the art and apprised of the inventive concept of this invention can readily determine which promoter or combination of promoters and in what amount for each promoter will appropriately protect against a particular set of poisons and amount of each poison in a specific pygas feed. Accordingly, as can be seen from the foregoing, it is particularly difficult to determine how much of the cumulative amount of poisons in a given feed will be removed but in every case a significant reduction of cumulative poisons, e.g., at least about 10 wt. % and up to about 100 wt. % based on the total weight of the cumulative poisons, will be realized, and a lengthening of the active life of the catalyst will be realized. The operating conditions of the method of this invention will, in view of the foregoing, vary widely as well, but will generally be from about 120 to about 450° F., at from about 100 to about 500 psig, and a weight hour space velocity (WHSV) feed rate of from about 1 to about 15 h −1 . EXAMPLE A full boiling range liquid pygas feed having about 40 wt. % C 3 -C 10 hydrocarbons (saturates, olefins, and diolefins); about 54 wt. % of a mixture of benzene, ethylbenzene, toluene, and xylenes; and about 4 wt. % styrene, with the remainder being essentially C 11 and heavier hydrocarbons and containing about 100 ppm of a mixture of arsenic, mercury, sodium, phosphorus, organo-sulfur, H 2 S, ammonia, and siloxanes is subjected to first stage hydrogenation/stabilization in a conventional liquid phase hydrotreater. The hydrotreater carries a hydrogenation catalyst prepared by conventional incipient wetness procedures comprising an alumina support having a Hammett acidity indicator of less Ho of about −1.0. The support carries about 0.3 wt. % palladium based on the total weight of the catalyst. The catalyst also carries elemental silver, zinc oxide, and reduced manganese as a promoter package, said package being about 3.0 wt. % of the total weight of the catalyst. The silver/zinc oxide/manganese can be present in the promoter package in a range of ratios 0-100/0-100/0-100, respectively. The pygas feed is passed through the foregoing reduced and otherwise activated catalyst at temperatures in the hydrotreater varying from about 150 to about 300° F. at a pressure of about 380 psig, at a WHSV of about 12 h −1 . The pygas feed leaving the hydrotreater contains about 10% less of the foregoing poisons based on the total weight of the poisons, and the active catalyst life is significantly extended by at least 10% of what it would have been had no promoter package been employed. Thus, in accordance with the inventive concept of this invention by employing a combination of a Group VIII catalyst on an alumina based support with at least one promoter as aforesaid, pygas can be selectively hydrogenated with improved tolerance to pygas poison severity.

A method for stabilizing pyrolysis gasoline by hydrogenating same over a Group VIII metal catalyst wherein the catalyst is promoted against poisoning by at least one metal from Groups I B, VI B, VII B, and zinc. Poisons preferentially bind with the promoters and not with the active catalytic metals.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 13/063,816 filed Mar. 14, 2011 now U.S. Pat. No. 8,686,104, currently pending, which is a national stage filing under 35 U.S.C. §371 of international application PCT/CA2009/001472 filed Oct. 16, 2009, which claims the benefit of U.S. Provisional Patent Application U.S. Ser. No. 61/193,081 filed Oct. 27, 2008, the entire contents of both of which are herein incorporated by reference. FIELD OF THE INVENTION The present invention relates to organic polymers, particularly to ladder polymers as materials for membrane gas separation and to processes for producing such ladder polymers. BACKGROUND OF THE INVENTION Polymeric microporous materials have had a great impact on academic research and industrial applications. To date, several types of microporous polymeric materials have been reported, for example solvent swollen crosslinked polymers (e.g., hypercrosslinked polystyrenes) [Davankov 1990; Tsyurupa 2002], rigid polymer networks [Budd 2003; McKeown 2006b; Webster 1992; Urban 1995; Wood 2007; McKeown 2002], rigid non-network polymers such as poly(1-trimethylsilyl-1-propyne) [Masuda 1983; Nagai 2001], certain polyimides [Tanaka 1992; Weber 2007], and a number of fluorinated polymers [Yu 2002] or polymers with bulky structural units [Dai 2004; Dai 2005]. Such microporous materials are of potential use in applications such as adsorbents, separation materials, and catalysis, since they combine high internal surface area (comparable with conventional microporous materials, such as zeolites or activated carbons) with the processability of polymers. Polymer membrane gas separation is a dynamic and rapidly growing field of separation technology [Stem 1994; Maier 1998] because it can offer a number of advantages, such as low energy use and capital cost [Pandey 2001]. In recent years, much effort has been devoted to the design and preparation of membrane materials whose transport properties are improved by overcoming the “trade-off” behavior between permeability and selectivity [Kim 1988; Lee 1988; Robeson 1991; Robeson 1994]. Recently, Budd and co-workers described a novel class of high-free volume polymeric microporous materials derived from nitrile monomers termed “polymers of intrinsic microporosity” (PIMs) whose rigid and randomly contorted structures increase high-free volume and surface area while decreasing chain packing efficiently and pore collapse in the solid state [Budd 2004a; Budd 2004b; Budd 2005a; Budd 2005b; McKeown 2005]. Compared to conventional gas separation polymers, the profound significance of these polymers is that they simultaneously display both very high gas permeability and good selectivity, contrary to the normal trade-off behavior of many traditional thermoplastic polymers. These microporous materials are soluble in several common solvents and can be readily fabricated into thin films. Consequently, they have attracted great interest as outstanding membrane materials which have a high potential for gas separation [Budd 2004b; Budd 2005b], adsorption of small molecules such as hydrogen [McKeown 2006b; Ghanem 2007; Budd 2007; McKeown 2007], heterogeneous catalysis [Budd 2003; McKeown 2006c] and as adsorbents for organic compounds [Budd 2003; Maffei 2006]. One important structural feature of PIMs is the presence of kinks in the repeat units. For example, PIM-1, the most studied PIM having a high molecular weight, is prepared from a dioxane-forming reaction between commercially available 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethylspirobisindane (TTSBI), and 2,3,5,6-tetrafluoroterephthalonitrile (TFTPN). Although McKeown and Budd suggested several compounds which include a spiro-contorted site as PIMs monomers [McKeown 2006a] there are only a few such monomers reported that provide PIMs for which gas permeabilities have been measured [Ghanem 2008; Carta 2008; Kricheldorf 2006; Budd 2004a]. These few PIMs have been synthesized using a controlled low temperature aromatic nucleophilic substitution polycondensation of tetraphenol monomers with tetrahalogenated monomers containing nitrile or imine electron-withdrawing groups. Among these polymers, they reported the gas permeability coefficients of some ladder polymers such as PIM-1 and PIM-7. PIM-1, is prepared from commercially available 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethylspirobisindane (TTSBI) and 2,3,5,6-tetrafluoroterephthalonitrile (TFTPN) by an efficient double aromatic nucleophilic substitution (SNAr) polycondensation. Few PIM structures with high molecular weight have been reported to date due to the few choices of available monomers and the inability of available monomers to produce sufficiently high molecular weight polymers. The latter is an important consideration in using these materials for membrane gas separation, where materials with high molecular weight are required for coating onto supports and for fabricating free-standing films. As is well known, the chemical structure and physical properties of membrane materials influence permeability and selectivity [Pandey 2001; Aoki 1999; Dai 2004; George 2001]. Many studies have shown that an improvement in gas transport properties could be obtained by modifying or tailoring the polymer structure. Considerable attention has been devoted to the preparation of new classes of partially fluorinated polymers because of their unusual properties. Trifluoromethyl groups (—CF 3 ) have been reported to significantly improve permeability and selectivity by increasing chain stiffness and reducing interchain interactions such as charge-transfer complexes (CTCs) [Banerjee 1999; Dai 2005]. In addition, —CF 3 groups in a polymer backbone serve several other purposes, such as enhancing polymer solubility (commonly referred to as the fluorine effect) without forfeiting thermal stability, lowering dielectric constants and water absorption, increasing the fractional free volume (FFV) of polymers, and increasing glass transition temperature (T g ) with concomitant decrease and/or elimination of crystallinity. The phenylsulfonyl group (—SO 2 C 6 H 5 ) is also a useful group which is employed beneficially in polymers used for gas separation. In general, the sulfonyl group (—SO 2 —) raises T g through increasing rigidity of the polymer chain and reduces FFV and permeability, while increasing selectivity [Paul 1994]. Processes for producing PIMs like those produced by Budd and coworkers have been studied under seemingly similar reaction conditions (Kricheldorf 2004). Kricheldorf and coworkers concluded that the majority of the product was cyclic which results in low molecular weight polymer and high polydispersity indices. Further, they found that the use of high temperature or high concentration of reactants, which have previously been shown to favor the decrease of cyclic oligomers, cannot be applied in this reaction due to explosive polycondensation yielding cross-linked product. It is well known that the rate-controlling step in this polycondensation reaction is the dissolution of the monomer salt. The cyclic compounds were formed in the reaction mixture as a result of the high dilution conditions created by poor solubility of the salt. Further, cyclization competes with every chain-growth step at all stages of polycondensation. Further, it has been observed that crosslinking happened quickly when the polymer precipitated from the reaction mixture. Therefore, it is of importance to develop an efficient polycondensation method for preparing PIMs that are substantially free of cyclics and crosslinked structures. Thus, there is a need in the art to expand the spectrum of high molecular weight PIMs having new structures derived from different monomers for use in membranes having improved gas permeability and separation properties. There is also a need for more efficient processes for producing such polymers. SUMMARY OF THE INVENTION In one aspect of the present invention there is provided a polymer of formula (I): where: n is an integer from 10 to 5,000; m is an integer from 10 to 5,000; Ar1 and Ar3 are the same or different and are residues derived from a tetra-hydroxy aromatic monomer, the tetra-hydroxy aromatic monomer being wherein R is the same or different and is H or a C 1 -C 8 alkyl, C 2 -C 8 alkenyl or C 3 -C 8 cycloalkyl group; and, Ar2 and Ar4 are the same or different and are residues derived from a tetra-halogenated aromatic monomer, the tetra-halogenated aromatic monomer being wherein X is F, Cl or Br, and R1 and R2 are the same or different and are wherein y is an integer from 1 to 8; with the proviso that when Ar1 is the same as Ar3 and Ar2 is the same as Ar4, R1 and R2 are not both —CN. Preferably, n is an integer from 40 to 750, more preferably from 40 to 500. Preferably, m is an integer from 40 to 750, more preferably from 40 to 500. The ratio of n:m is preferably in a range of 1:99 to 99:1, more preferably 70:30 to 30:70, for example 50:50. In one embodiment, m=2n. R is preferably H, methyl or ethyl. Ar1 and Ar3 are preferably residues derived from X is preferably F. Preferably, y is an integer from 1 to 4, more preferably y is 1 or 2. Preferably, Ar2 and Ar4 are residues derived from R1 and R2 are the same or different and are preferably In another aspect of the present invention, there is provided a process for producing a polymer of formula (I) as defined above comprising: contacting one or more tetra-hydroxy aromatic monomers as defined by Ar1 and Ar3 above with one or more tetra-halogenated aromatic monomers as defined by Ar2 and Ar4 above at a temperature in a range of 130-200° C. in a solvent mixture comprising an aprotic polar solvent and a non-polar solvent. The monomers are preferably present in a concentration in a range of 5-50% w/w based on weight of the aprotic polar solvent. Such conditions unexpectedly reduce polymer crosslinking, reduce the quantity of cyclic species formed, increase the yield in a shorter period of time (e.g. complete reaction in under 1 hour), result in higher molecular weight polymers with a narrower molecular weight distribution, result in polymers with improved mechanical properties and increase surface area of the bulk polymer. Synthesis of Polymers: Generally, ladder polymers of the present invention may be synthesized by SNAr polycondensation of tetra-hydroxy aromatic monomers with tetra-halogenated aromatic monomers as shown in Scheme 1, wherein Ar1, Ar2, Ar3, Ar4, X, n and m are as defined above. When Ar1 is the same as Ar3 and Ar2 is the same as Ar4, the resulting polymer is a homopolymer with [Ar1-Ar2] repeating units. When Ar1 and Ar3 are the same but Ar2 is different from Ar4, the resulting polymer is a copolymer with [Ar1-Ar2]-[Ar1-Ar4] repeating units. When Ar1 and Ar3 are different but Ar2 and Ar4 are the same, the resulting polymer is a copolymer with [Ar1-Ar2]-[Ar3-Ar2] repeating units. The base may be any suitable base for use in SNAr polycondensation reactions. Aprotic bases are preferred. Some examples of suitable bases include potassium carbonate (K 2 CO 3 ), sodium carbonate (Na 2 CO 3 ), sodium fluoride (NaF), potassium fluoride (KF) or mixtures thereof. Protic bases, e.g. sodium hydroxide (NaOH), potassium hydroxide (KOH) or mixtures thereof, may be suitable bases if there are no hydrolysable groups (e.g. —CN) on the monomers. The polycondesation is preferably done in an inert atmosphere. The inert atmosphere may comprise gases such as, for example, argon, nitrogen or mixtures thereof. Water and oxygen are preferably excluded as far as possible in the reaction conditions. The polycondensation is preferably done in a solvent suitable for polycondensation reactions. The solvent is preferably dried to remove water and degassed to remove oxygen. The solvent is preferably an aprotic polar solvent, for example, N,N-dimethylacetamide (DMAc), N′N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), N-methylpyrrolidinone (NMP), sulfolane, diphenylsulfone or mixtures thereof. In one particularly advantageous embodiment, a non-polar solvent is also used in addition to the aprotic polar solvent. The non-polar solvent is preferably benzene, alkylbenzenes (e.g. toluene, xylene, mesitylene), long chain hydrocarbons (e.g. octane), ethyl acetate or mixtures thereof. Benzene, toluene, xylene or mixtures thereof are particularly preferred. The non-polar solvent solubilizes the polymer formed and helps solubilize the monomers in the aprotic polar solvent during the reaction. The non-polar solvent is preferably used in an amount about 2-10 times by volume of the aprotic polar solvent. Without being held to any particular mode of action, it is known that the rate-controlling step in these type of polycondensation reactions is the dissolution of monomer salts in the aprotic polar solvent. In prior art syntheses of PIMs, cyclic compounds were formed in the reaction mixture as a result of high dilution conditions created by poor solubility of the monomer salt in the aprotic polar solvent. Further, cyclization competes with every chain-growth step at all stages of polycondensation. Further, it has been previously observed that crosslinking happens quickly when the polymer precipitates out from the reaction mixture, therefore the presence of non-polar solvent helps solubilize the polymer reducing the amount of polymer precipitation thereby reducing the amount of crosslinking. The polycondensation is preferably done at elevated temperature for a period of time suitable to maximize yield. The temperature is preferably in a range of from 50-200° C. The time may be, for example, from less than about 1 hour to as high as 72 hours. In a particularly preferred embodiment, the temperature is in a range of 130-200° C., in particular 150-200° C., for example about 155-160° C., which can reduce the time required to less than one hour. To be able to reach such temperatures without undue crosslinking and/or cyclization, it is advantageous to utilize a non-polar solvent in addition to an aprotic polar solvent. Further, it is advantageous to use a high intensity homogenizer to reduce reaction time even further. Reaction times can be reduced to 15 minutes or less by using such a high intensity homogenizer. Homopolymers: When Ar1 and Ar3 are the same, and Ar2 and Ar4 are the same, with the proviso that R1 and R2 are not —CN, the polymer is a homopolymer of formula (II): where p is an integer from 20 to 10,000, and Ar1 and Ar2 are as defined above with the proviso that R1 and R2 are not —CN. Preferably, p is an integer from 40 to 1500, more preferably from 40 to 1000, yet more preferably 40 to 500. Ar2 preferably comprises one or more sulfone (—SO 2 —) groups, one or more trifluoromethyl (—CF 3 ) groups or a mixture of —SO 2 — and —CF 3 groups. In Ar2, X is preferably F. More preferably, Ar2 comprises two —SO 2 — groups, or one —SO 2 — group and one —CF 3 group. In particularly preferred embodiments, when Ar2 is a residue derived from X is F; R1 is —CF 3 , CH 3 CH 2 SO 2 —, Ph-SO 2 — or p-CH 3 O-Ph-SO 2 —; and, R2 is CH 3 CH 2 SO 2 —, Ph-SO 2 — or p-CH 3 O-Ph-SO 2 —. Ar1 is preferably a residue derived from As discussed previously, certain homopolymeric PIMs have been previously reported. However, the previously reported homopolymers are limited by one or more of low molecular weight, crosslinking, too broad of a molecular weight distribution, difficulty in preparation or scale-up, fixed physical properties (e.g. fixed gas permeabilities and gas pair selectivities, few monomer choices, fewer choices of gas permeability and gas pair selectivity properties, and inability to readily functionalize the main chain structure. Homopolymeric PIMs of the present invention advantageously extend the possible structures of PIMs, increase gas pair selectivity coupled with a permeability that combines to exceed the Robeson upper bound, increase chemical stability, increase molecular weight, broaden the range of physical properties which are relevant to gas permeability and gas pair selectivity properties, and increase the capability to functionalize the PIM. Copolymers: When Ar1 and Ar3, or Ar2 and Ar4, are different, the polymer is a copolymer. Copolymeric PIMs have been hitherto unknown in the art. The copolymers may be random or block copolymers. In copolymers of the present invention, Ar1, Ar2, Ar3 and Ar4 are as defined above. Ar2, Ar4 or both Ar2 and Ar4 preferably comprise one or more sulfone (—SO 2 —) groups, one or more trifluoromethyl (—CF 3 ) groups or a mixture of —SO 2 — and —CF 3 groups. In Ar2 and Ar4, X is preferably F. In a particularly preferred embodiment, either Ar2 or Ar4 comprises one or more sulfone (—SO 2 —) groups, one or more trifluoromethyl (—CF 3 ) groups or a mixture of —SO 2 — and —CF 3 groups, and the other of Ar2 and Ar4 comprises —CN groups. In particularly preferred embodiments, when Ar2 and Ar4 are residues derived from X is F; R1 is —CF 3 , CH 3 CH 2 SO 2 —, Ph-SO 2 — or p-CH 3 O-Ph-SO 2 — in Ar2; R2 is CH 3 CH 2 SO 2 —, Ph-SO 2 — or p-CH 3 O-Ph-SO 2 — in Ar2; and, R1 and R2 are —CN in Ar4. In another particularly preferred embodiment, one of Ar2 and Ar4 is a residue derived from As discussed previously, certain homopolymeric PIMs have been previously reported. However, the previously reported homopolymers are limited by one or more of low molecular weight, crosslinking, too broad of a molecular weight distribution, difficulty in preparation or scale-up, fixed physical properties (e.g. fixed gas permeabilities and gas pair selectivities, few monomer choices, and fewer choices of gas permeability and gas pair selectivity properties. Copolymeric PIMs (CoPIMs) have one or more of the following advantages: increase in the number of possible structures; increased molecular weight; reduced crosslinking; narrower molecular weight distribution; easier preparation or scale-up; increased thermal and/or chemical stability; tunability of gas permeability and gas pair selectivity properties due to the ability to utilize different ratios of monomers; and, increase in selectivity coupled with a permeability that combines to exceed the Robeson upper bound. Uses of Polymers: Polymers of the present invention are useful as materials for gas separation, vapor separation, adsorbents and catalysis. They may be conveniently cast in any suitable form, for example free-standing membranes, dense films, coated films or membranes on support materials (e.g. thin film composite membranes), beads or powders. Further features of the invention will be described or will become apparent in the course of the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more clearly understood, embodiments thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which: FIG. 1A depicts chemical structures of various monomers referred to herein; FIG. 1B depicts chemical structures of PIM-1 and PIM-7; FIG. 2 depicts 1 H NMR spectra of TFMPSPIM1, TFMPSPIM3 and PIM-1; FIG. 3 depicts 13 C NMR spectra of TFMPSPIM1, TFMPSPIM3 and PIM-1; FIG. 4 depicts GPC curves for TFMPSPIM1-4 and PIM-1; FIG. 5 depicts WAXD of TFMPSPIM1-4 and PIM-1; FIG. 6 depicts a graph showing the trade-off between O 2 permeability and O 2 /N 2 selectivity of PIM-1 and TFMPSPIM1-4 membranes relative to the Robeson upper bound line; FIG. 7 depicts models of the PIM-1 and TFMPSPIM1 as calculated with energy minimization by HyperChem™ software; FIG. 8 depicts GPC curves for the THDNPIM polymer series and PIM-1; FIG. 9 depicts MALDI-TOF mass spectrum of THDNPIM-100; FIG. 10 depicts molecular models of PIM-1 and THDNPIM-100 as calculated with energy minimization; FIG. 11 depicts 1 H NMR spectra of THDNPIM-50 and PIM-1; FIG. 12 depicts a graph showing the trade-off between O 2 permeability and O 2 /N 2 selectivity of THDNPIM-33 and PIM-1 membranes relative to the Robeson's upper bound; FIG. 13 depicts WAXD of THDNPIM-33, THDNPIM-50 and PIM-1; FIG. 14 depicts aromatic nucleophilic substitution reaction of tetrafluoro monomers; FIG. 15 depicts 1 H NMR spectra of PIM-1 (top), BSPIM1-50, BSPIM2-50 and BSPIM3-50; FIG. 16 depicts WAXD of BSPIMs-100 and PIM-1; and, FIG. 17 depicts molecular models of the PIM-1 and BSPIMs-100 as calculated with energy minimization. DESCRIPTION OF PREFERRED EMBODIMENTS Materials: Hexafluorobenzene (Apollo Scientific Ltd.), 4-methoxylbenzenethiol (Matrix Scientific), 4-Bromo-2,3,5,6-tetrafluorobenzotrifluoride (Matrix Scientific), ethanethiol (Sigma-Aldrich), thiophenol (Sigma-Aldrich), 2,3-naphthalenediol (Sigma-Aldrich), dimethylacetamide (DMAc, Sigma-Aldrich), ferric chloride hexahydrate (FeCl 3 .6H 2 O, Anachemia), sodium hydride (60% NaH dispersion in mineral oil, Sigma-Aldrich), formic acid (Sigma-Aldrich), hydrogen peroxide solution 30% (w/w) in H 2 O (H 2 O 2 , Aldrich), anhydrous potassium carbonate (K 2 CO 3 , Sigma-Aldrich), tetrahydrofuran (THF, Aldrich) and toluene (Sigma-Aldrich) were reagent grade and used as received. 5,5′,6,6′-Tetrahydroxy-3,3,3′,3′-tetramethylspirobisindane (TTSBI, Sigma-Aldrich) was purified by re-crystallization from methanol. Tetrafluoroterephthalonitrile (TFTPN, Matrix scientific) was purified by vacuum sublimation at 150° C. under inert atmosphere. Pyridine (Sigma-Aldrich) was distilled from CaH 2 . Characterization Methods: The structures of the polymeric materials were fully characterized using nuclear magnetic resonance (NMR) spectroscopy. NMR analyses were recorded on a Varian Unity Inova spectrometer at a resonance frequency of 399.961 MHz for 1 H, 376.276 MHz for 19 F and 100.579 MHz for 13 C. 1 H and 19 F NMR spectra were obtained from samples dissolved in CDCl 3 or DMSO-d 6 using a 5 mm pulsed field gradient indirect detection probe. 1 H- 13 C heteronuclear 2D experiments (HSQC, HMBC) were also obtained from the same indirect detection probe. 13 C NMR spectra were collected using a 5 mm broadband probe. The solvent signals (CDCl 3 1 H 7.25 ppm, 13 C 77.00 ppm; DMSO-d 6 1 H 2.50 ppm, 13 C 39.43 ppm) were used as the internal references. An external reference was used for 19 F NMR: CFCl 3 0 ppm. Molecular weight and molecular weight distributions were measured by GPC using Ultrastyragel™ columns and THF as the eluent at a flow rate of 1 mL/min. The values obtained were determined by comparison with a series of polystyrene standards. Elemental analysis was carried out with a Thermoquest™ CHNS—O elemental analyzer. Polymer thermal degradation curves were obtained from thermogravimetric analysis (TGA) (TA Instruments model 2950). Polymer samples for TGA were initially heated to 120° C. under nitrogen gas and maintained at that temperature for 1 h for moisture removal and then heated to 600° C. at 10° C./min for degradation temperature measurement. Glass transition temperatures (T g ) were observed from differential scanning calorimetry (DSC) (TA Instruments model 2920), and samples for DSC were heated at 10° C./min under a nitrogen flow of 50 mL/min, then quenched with liquid nitrogen and reheated at 10° C./min for the T g measurement. Wide-angle X-ray diffraction (WAXD) was used to investigate d-spacing. A Bruker AXS GADDS instrument was utilized with Co radiation of wavelength (λ) 1.789 Å or Cu Kr radiation of wavelength (λ) 1.54 Å. The value of the d-spacing was calculated by means of Bragg's law (d=λ/2 sin θ), using θ of the broad peak maximum. Dense polymer films for gas permeability measurements were prepared from 1-2 wt % polymer solutions in chloroform. Polymer solutions were filtered through 0.45 μm polypropylene or poly(tetrafluoroethylene) (PTFE) filters and then cast into either glass or Teflon™ Petri dishes in a glove box and allowed to evaporate slowly for 1 day. The films were soaked in methanol and dried in a vacuum oven at 100° C. for 24 h. The resulting membranes with thickness in the range of 60-80 μm were bright yellow and flexible. The absence of residual solvent in the films was confirmed by weight loss tests using TGA. Permeability coefficients (P) of N 2 , O 2 and CO 2 were determined at 25° C. with a feed pressure of 50 psig and atmospheric permeate pressure using the constant-pressure/variable-volume method. The permeation flow was measured by a mass flow meter (Agilent ADM 2000) or a bubble meter. Permeability (P) was calculated by using a following equation: P = ( 273 T ) · ( ⅆ V ⅆ t ) · ( l Δ ⁢ ⁢ p · A ) where dV/dt is the permeate-side flow rate (cm 3 /s), T is the operation temperature (K) and Δp is the gas pressure differential between the upstream and downstream sides of the membrane. The membrane effective area (A) was 9.6 cm 2 . Example 1 Preparation of Heptafluoro-p-Tolylphenylsulfone (HFTPS) Monomer Into a 50 mL three-necked flask equipped with a magnetic stirrer, an argon inlet and a condenser, thiophenol (2.42 g, 0.022 mol), NaH (0.88 g, 0.022 mol), DMAc (5 mL) were added. The mixture was cooled to −20° C. using an ice salt bath (NaCl/ice=3:1, w:w) and stirred for 1 h. 4-Bromo-2,3,5,6-tetrafluorobenzotrifluoride (5.94 g, 0.02 mol) in 5 mL DMAc was added dropwise, then the temperature was gradually increased to room temperature. After stirring at room temperature for 6 h, the reaction mixture was poured into water and the crude product was washed 3 times. The orange color oil was extracted with chloromethane and dried over MgSO 4 . After removal of chloromethane, the resulting crude heptafluoro-p-tolylphenylsulfide was oxidized with formic acid (5 mL) and H 2 O 2 (30%) (6 g) at 50° C. for 2 h, resulting in a white-yellow solid sulfone product that was initially purified by chromatography (using 1/1 v/v dichloromethane/hexane). Pure product in the form of white needle crystals was obtained by recrystallization from hexane. Yield: 65%. Mp: 134° C. Elem. Anal. Calcd for C 13 H 5 F 7 O 2 S (358.23 g/mol): C, 43.95%; H, 1.41%; S, 8.95%. Found: C, 43.24%; H, 1.39%; S, 8.95%. 1 H NMR (chloroform-d) δ 8.09 (d, J=8.0 Hz, 2H), 7.73 (t, J=8.0 Hz, 1H), 7.62 (t, J=8.0 Hz, 2H); 19F NMR (chloroform-d) δ −57.6 (t, J=22.5 Hz, 3F), −134.3 (m, 2F), −136.9 (m, 2F). 13C NMR (chloroform-d) δ 145.8-143.0 (d, J=264 Hz, 2H), 145.5-142.7 (d, J=264 Hz, 2H), 139.9 (s, 1H), 135.3 (s, 1H), 129.8 (s, 2H), 128.2 (s, 2H), 125.3-125.0 (t, J=14 Hz, 1H), 124.1-115.9 (q, J=275 Hz, 1H), 114.2-113.9 (m, 1H). Example 2 Preparation of 2,2′3,3′-Tetrahydroxy-1,1′-Dinaphthyl (THDN) Monomer A literature procedure was employed [Toda 1989]. A mixture of 2,3-naphthalenediol (16 g, 0.1 mol) and FeCl 3 .6H 2 O (27 g, 0.2 mol) was finely powdered by agate mortar and pestle. The mixture was then put in a test tube and irradiated with ultrasound at 50° C. for 1 h. Decomposition of the reaction mixture with dilute HCl gave crude 2,2′3,3′-tetrahydroxy-1,1′-dinaphthyl in 85% yield. The tetrol was recrystallized from THF three times to give white needle powder at 53% yield. Mp>300° C. 1 H NMR (DMSO-d 6 ) δ 6.80-6.82 (d, J=8.0 Hz, 2H), 6.94-6.98 (t, J=8.0 Hz, 2H), 7.14-7.18 (t J=8.0 Hz, 2H), 7.24 (s, 2H), 7.64-7.62 (d, J=8.0 Hz, 2H), 8.41 (s, OH), 10.07 (s, OH) Elem. Anal. Calcd for C 20 H 14 O 4 (318.32 g/mol): C, 75.46%; H, 4.43% Found: C, 75.41%; H, 4.56%. Example 3 Preparation of Disulfone Monomers Three dithioethers were synthesized by modifying known procedures [Kulka 1959; Robson 1963; Langille 1972]. Generally, into a 250 mL three-neck flask equipped with a magnetic stirrer, an argon inlet and a condenser, a thiol (54 mmol), NaH (54 mmol), and dry pyridine (15 mL) were added. The reaction mixture was cooled to −20° C. using an ice salt bath (NaCl:ice=3:1, w/w), and stirred for 1 h. Thereafter, the reaction mixture was added dropwise into hexafluorobenzene (27 mmol) and the temperature was gradually increased to room temperature. After stirring at room temperature for 30 min, the reaction mixture was refluxed for another 20 min and then poured into water. The crude product was washed with 8 N hydrochloric acid and extracted with dichloromethane and dried over MgSO 4 . After purifying, the dithioethers (5 g) were oxidized with formic acid (15 mL) and H 2 O 2 (30%, 20 g) and maintained at 100° C. for 24 h, resulting in white disulfone products, which were collected and purified. 1,2,4,5-Tetrafluoro-3,6-Bisphenylsulfonylbenzene (TFBPSB) Monomer The dithioether was purified by chromatography (using 1/4, v/v chloromethane/hexane). Pure product in the form of white needle crystals was obtained by recrystallization from hexane. Yield: 48%. Mp: 109-110° C. Elem. Anal. Calcd for C 18 H 10 F 4 S 2 (366.4 g/mol): C, 59.01%; H, 2.75%; S, 17.5%. Found: C, 58.51%; H, 2.69%; S, 17.62%. 1 H NMR (chloroform-d) δ 7.43-7.39 (m, 4H), 7.35-7.29 (m, 6H). 19 F NMR (chloroform-d) δ −132.4 (s, 4F). 13 C NMR (chloroform-d) δ 146.9 (d, J=251 Hz), 132.5 (s), 131.0 (s), 129.4 (s), 128.1 (s), 115.3 (m). After oxidation, the raw TFBPSB disulfone monomer was recrystallized from dimethylformamide (DMF), to give white needle crystals in a yield of 81%. Mp>300° C. Elem. Anal. Calcd for C 18 H 10 F 4 O 4 S 2 (430.39 g/mol): C, 50.23%; H, 2.34%; S, 14.9%. Found: C, 49.57%; H, 2.042%; S, 14.89%. 1 H NMR (DMSO-d 6 ) δ 8.03 (d, J=8.0 Hz, 4H), 7.85 (t, J=8.0 Hz, 2H), 7.71 (t, J=8.0 Hz, 4H). 19 F NMR (DMSO-d 6 ) δ −135.6 (s, 4F). 13 C NMR (DMSO-d 6 ) δ 145 (dm, J=256 Hz), 139.2 (s), 135.6 (s), 129.9 (s), 127.7 (s), 124.2 (m). 1,2,4,5-Tetrafluoro-3,6-Bis(Methoxy-4-Phenylsulfonyl)Benzene (TFBMPSB) Monomer The dithioether was purified by chromatography (using 1/2, v/v chloromethane/hexane). Pure product in the form of white flake crystals was obtained by recrystallization from hexane. Yield: 51%. Mp: 104° C. Elem. Anal. Calcd. for C 20 H 14 F 4 O 2 S 2 (426.45 g/mol): C, 56.33%; H, 3.31%; S, 15.04%. Found: C, 55.30%; H, 3.04%; S, 15.01%. 1 H NMR (chloroform-d) δ 7.46 (d, J=8 Hz, 4H), 6.84 (d, J=8 Hz, 4H), 3.80 (s, 6H). 19 F NMR (chloroform-d) δ −133.7 (s, 4F). 13 C NMR (chloroform-d) δ 160.2 (s), 146.7 (dm, J=251 Hz), 134.8 (s), 122.4 (s), 114.8 (s), 109.8 (m), 55.3 (s). After oxidation, the crude TFBMPSB disulfone monomer was recrystallized from DMF, to give white needle crystals in 78% yield. Mp>300° C. Elem. Anal. Calcd. for C 20 H 14 F 4 O 6 S 2 (490.45 g/mol): C, 48.98%; H, 2.88%; S, 13.08%. Found: C, 48.38%; H, 3.047%; S, 13.01%. 1 H NMR (DMSO-d 6 ) δ 7.95 (dd, J=8 Hz, 4H), 7.20 (dd, J=8 Hz, 4H), 3.86 (s, 6H). 19 F NMR (DMSO-d 6 ) δ −136.2 (s, 4F). 13 C NMR (DMSO-d 6 ) δ 161.3 (s), 144.5 (dm, J=251 Hz), 133.3 (s), 130.3 (s), 123.1 (m), 115.2 (s), 54.91 (s). 1,2,4,5-Tetrafluoro-3,6-Bis(Ethylsulfonyl)Benzene (TFBESB) Monomer The 1,4-bis(ethylthio)-2,3,5,6-tetrafluorobenzene was oxidized without purification. The crude disulfone was recrystallized in DMF and toluene to give white needles of TFBESB disulfone monomer in 72% yield. Mp: 239° C. Elem. Anal. Calcd. for C 10 H 10 F 4 O 4 S 2 (334 g/mol): C, 35.93%; H, 3.02%; S, 19.18%. Found: C, 35.65%; H, 2.91%; S, 18.65%. 1 H NMR (DMSO-d 6 ) δ 3.61 (q, J=8 Hz, 4H), 1.27 (t, J=8 Hz, 6H). 19 F NMR (DMSO-d 6 ) δ −135 (s, 4F). 13 C NMR (DMSO-d 6 ) δ 142.4 (dm, J=251 Hz), 129.94 (m), 51.2 (s), 6.4 (s). Example 4 Preparation of 2,3,7,8-Tetrafluoro-5,5′,10,10′-Tetraoxidethianthrene (TFTOT) Monomer 2,3,7,8-tetrafluorothianthrene was synthesized by modifying a known procedure [Bock 1982]. Thus, into a 250 mL three-neck flask equipped with a magnetic stirrer, an argon inlet and a condenser, difluorobenzene (20 mmol), AlCl 3 (60 mmol), and dry dichloromethane (50 mL) were added. The reaction mixture was cooled to 0-20° C. using an ice salt bath (NaCl:ice=3:1, w/w), and stirred for 1 h. Thereafter, the reaction mixture was added dropwise into S 2 Cl 2 (20 mmol) and the temperature was gradually increased to room temperature. After stirring at room temperature for 2 hour, the reaction mixture was refluxed for another 20 min and then poured into water. The crude product was washed with 8 N hydrochloric acid and extracted with dichloromethane and dried over MgSO 4 . After removed the dichloromethane, the 2,3,7,8-tetrafluorothianthrene (5 g) was recrystallized from hexane to give white needle crystals in a yield of 49%. Mp=108° C. 1 H NMR (chloroform-d) δ 7.309 (t, J=8.0 Hz, 4H). 19 F NMR (chloroform-d) δ −136.4 (s, 4F). 13 C NMR (chloroform-d) δ 150.07 (dd, J=252 Hz), 131.34 (t, J=5.3 Hz), 117.64 (m). To synthesize the TFTOT monomer, 20 g of 2,3,7,8-tetrafluorothianthrene was oxidized with formic acid (100 mL) and CrO 3 (excess) and maintained at 100° C. for 24 h, resulting in white 2,3,7,8-tetrafluoro-5,5′,10,10′-tetraoxidethianthrene (TFTOT), which were collected and recrystallized from DMF to give white flake crystals in a yield of 92%. Mp>300° C. Elem. Anal. Calcd for C 12 H 4 F 4 O 4 S 2 (352.28 g/mol): C, 40.91%; H, 1.14%; S, 18.20%. Found: C, 41.13%; H, 1.09%; S, 18.26%. 1 H NMR (DMSO-d 6 ) δ 8.087 (t, J=8.0 Hz, 4H). 19 F NMR (DMSO-d 6 ) δ −123.185 (t, J=8.0 Hz, 4F). Example 5 Preparation of PIM-1 Using a Process of the Present Invention Into a 100 mL three-necked flask equipped with a magnetic stirrer, an argon inlet, and a Dean-Stark trap, TFTPN (2.001 g, 0.01 mol) and TTSBI (3.404 g, 0.01 mol), anhydrous K 2 CO 3 (4.14 g, 0.03 mol), DMAc (20 mL), and toluene (10 mL) were added. During the initial 20-30 minutes, a small amount of water was observed in the Dean-Stark trap. The mixture was refluxed at 160° C. for 40 min, and then the viscous solution was poured into methanol. A yellow flexible threadlike polymer was obtained. The polymer product was dissolved into chloroform and re-precipitated from methanol. The resulting polymer was refluxed for several hours with deionized water, and dried at 100° C. for 48 h. Example 6 Comparison of PIM-1 Properties for PIM-1 Polymers Produced by a Process of the Present Invention and by a Prior Art Process PIM-1 polymers were produced using a standard prior art procedure (Budd 2004a] and a procedure in accordance with the present invention. Reaction conditions are shown in Table 1. Various physical properties of the PIM-1 polymers produced were determined and are shown in Table 2. It is evident from Table 2 that the process of the present invention results in polymers having larger M n , which is advantageous for materials for gas separation membranes, Further, as evidenced by the M w /M n ratio, PIM-1 polymers produced by the present invention have less cyclic and cross-linked fractions. Furthermore, mechanical properties like tensile stress and strain are improved in PIM-1 polymers produced by the process of the present invention. Finally, PIM-1 polymers produced by the present process have enhanced surface area (S BET ). TABLE 1 Reaction conditions for PIM-1 polymer production Condition Budd 2004a Present Invention Temperature 65° C. 155° C. TTSBI:TFTPN:K 2 CO 3 1:1:2.05 1:1:3 Aprotic polar solvent DMAc DMAc TTSBI:Aprotic polar solvent 1 mol:7 mL 1 mmol:2 mL TTSBI:Toluene 1 mol:0 mL 1 mmol:6 mL Time 72 h 45-60 min TABLE 2 Properties of PIM-1 polymers produced by different processes PIM-1 from Present PIM-1 from Budd 2004a Invention M n 54,000 71,000 M w 473,000 142,000 M w /M n 8.7 2.0 Yield (%) 80 90 Tensile stress at break (MPa) — 47.6 Tensile strain at break (%) — 13.7 S BET (m 2 g −1 ) ~700 780 Example 7 Preparation and Characterization of PIM Ladder Polymers Containing Trifluoromethyl and Phenylsulfone Side Groups (TFMPSPIM1-4) A series of TFMPSPIM ladder polymers 1-4 were synthesized by polycondensation of TTSBI, HFTPS and TFTPN (with the molar ratio 1:1:0; 3:2:1; 2:1:1; 3:1:2) using a procedure similar to that of Example 5, and illustrated in Scheme 2. Monomer Synthesis Alsop et al. previously reported the synthesis of HFTPS by oxidation of heptafluoro-p-tolylphenylsulfide, obtained from the reaction of thiophenol with octafluorotoluene [Alsop 1962]. As far as we are aware, HFTPS has not previously been utilized as a monomer in a polymerization reaction. The present synthetic method is different from the previous report and comprises two steps as shown in Scheme 2. In the first step, the bromine atom in 4-bromo-2,3,5,6-tetrafluorobenzotrifluorde is displaced by thiophenol using NaH at −20° C. Both F-Ar and Br-Ar react with thiophenols under basic conditions by aromatic nucleophilic substitution reaction, but the reactivity is different. At higher temperatures, F-Ar is more reactive, while at lower temperatures, Br-Ar is more easily displaced, since —Br is an efficient leaving group specifically for reactions with thiophenolates. Elevated temperatures (above 60° C.) or longer reaction times would lead to more byproducts, indicating that the comparative selectivity of thiophenol group decreases. K 2 CO 3 can be also used as a base for this reaction at these conditions. However, at lower temperatures, water cannot be removed and it continues to react with Ar-F to form Ar-OH, thereby reducing the yield. A small amount of CaH 2 was added to the reaction at the beginning to eliminate the water efficiently. Although the resulting Ca(OH) 2 was basic, it does not react readily with F-Ar at low temperature due to the poor solubility. The crude product was oxidized without purification. The thioether could be completely converted to sulfone using excess H 2 O 2 in a heterogeneous formic acid suspension at 50° C. within 2 hours. In terms of its use as a monomer for ladder polymers, the new monomer relies on the electron withdrawing power of sulfone, rather than nitrile used in the synthesis of PIM-1. Polymerization The ladder PIMs (including TFMPSPIM and PIM-1) containing —CF 3 , —SO 2 C 6 H 5 , and —CN groups, were synthesized by SNAr polycondensation using various feed ratios of TTSBI/HFTPS/TFTPN, so that polymers with different molar percentages of —CN and —CF 3 /—SO 2 C 6 H 5 (Scheme 2) were obtained. The ideal structures of the ladder polymers are linear chains without crosslinking. The characterization results are listed in Table 3. The polymers are named TFMPSPIM1-4, where PIM stands for polymer of intrinsic microporosity, TFM and PS refers to trifluoromethyl and phenylsulfonyl respectively. TABLE 3 Physical Properties of TFMPSPIM1-4 and PIM-1 Tensile Tensile stress at strain at TTSBI HFTPS TFTPN break break Polymers (molar ratio) (molar ratio) (molar ratio) M n M w M w /M n (MPa) (%) TFMPSPIM1 1 1 0 77,000 156,000 2.0 33.6 3.9 TFMPSPIM2 3 2 1 71,000 143,000 2.0 38.3 4.4 TFMPSPIM3 2 1 1 66,000 139,000 2.1 43.3 5.2 TFMPSPIM4 3 1 2 64,000 110,000 1.7 46.2 5.6 PIM-1 1 0 1 55,000 85,000 1.6 47.1 11.2 The synthesis of ladder polymers with substantially reduced amounts of cyclic species or crosslinking was accomplished using new polymerization conditions applied to PIMs. A higher polymerization temperature of 160° C. and higher monomer concentrations (monomer:solvent=1 mmol:2 mL) in DMAc were used compared with the previously reported polymerization conditions conducted at lower temperatures. DMAc is largely compatible with both the monomer salts and growing polymer chain at this temperature. In addition, excess toluene (toluene:DMAc=4:1 v/v) was introduced into the reaction not only to remove generated water, but to provide solubility enhancement of the polymer. In a similar reaction carried out in the absence of excess toluene, crosslinked polymer formed readily in the latter stages of polymerization (approx. the last 10 min). The new high-temperature polymerization procedure for PIM-1 reported here led to high molecular weight polymers within 40 min. Compared with the originally reported PIM synthesis [Budd 2004b], the reaction conditions reported here require less time and the explosion-like polycondensation is relatively easy to control. In contrast, with typical nucleophilic aromatic substitution polycondensation reactions to produce poly(aryl ether)s, the formation of the ladder polymers is more complicated. As shown in Scheme 1 and Scheme 2, each monomer has four reactive groups, greatly increasing the susceptibility for crosslinking to occur. However, using the present reaction conditions, GPC results (Table 3) show that high molecular weight polymers (M n >55,000 Da) were obtained and the polydispersity index is approximately 2.0, which is consistent with the results of typical polycondensation reactions in which each monomer has two reactive sites. On GPC curves ( FIG. 4 ), there is no shoulder peak in the low or high molecular weight region around the main peak, indicating that it is a clean reaction with few crosslinked or cyclic structures. GPC results also showed that TFMPSPIM1-4 polymers with higher molecular weight as compared to PIM-1 were obtained under the same reaction condition. The M n of the polymer decreased as the ratio of monomer HFTPS in the copolymer was reduced. The homopolymer prepared from HFTPS had the highest M n , while PIM-1 homopolymer had the lowest. A plausible explanation is that the —CF 3 group and —SO 2 C 6 H 5 enhance the solubility of the polymer and growing chain, so that the polymer chains are unfolded, uncoiled and unpacked, and the chain-growth step reaction is facilitated. Meanwhile, the —F and —OH on neighboring aromatic rings readily react with each other and form ladder structures with less propensity for crosslinking. The mechanical properties of the ladder polymer series are listed in Table 3. Tensile stress at break and tensile strain at break decreased due to the introduction of increasing amounts of —CF 3 and —SO 2 C 6 H 5 into the polymer chain. In the series from PIM-1 to TFMPSPIM4, tensile strain at break drops off sharply from 11.2% to 5.6% while almost maintaining the same tensile stress at break (from 47.1 to 46.2 MPa), which implies that the polymer had additional rigidity due to the introduction of pendant —CF 3 and —SO 2 C 6 H 5 groups. NMR Analysis The TFMPSPIM1 and PIM-1 homopolymers and TFMPSPIM2-4 copolymers were fully characterized by 1 H, 13 C and 19 F NMR spectroscopy ( 19 F NMR (chloroform-d) −56.2 ppm (s, 3F)). Carbon NMR was particularly useful as there are many quaternary carbon atoms on these polymers. Stacked 1 H NMR spectra of TFMPSPIM1, PIM-1 and TFMPSPIM3 are displayed in FIG. 2 while 13 C spectra of the same polymer series are displayed in FIG. 3 . The aliphatic and aromatic hydrogen signals of PIM-1 and TFMPSPIM1 were unambiguously assigned with the help of 2D HSQC and HMBC. Long range C—H correlations involving C1 with CH 3 (2JC-C—H) and H6 (3JC-C—C—H) helped differentiate the H6 signal from H9. Most PIM-1 carbon signals were assigned using direct HSQC C—H couplings. All the quaternary carbon atom signals from the TTSBI monomer part were identified by multiple bonds C—H correlations (HMBC) with previously assigned proton frequencies. The absence of hydrogen atoms on the TFTPN monomer results in no signals in 2D HSQC, HMBC NMR. Therefore C10′, C11′ and —CN were assigned based on their chemical shifts. C10′ is strongly deshielded by the electronegative oxygen atom and was therefore easily assigned as the signal at the highest frequency (139 ppm). On the other hand, C11′ is shielded by the electron donating effect through delocalization of the same oxygen atoms. C11′ is sandwiched between two C—O groups and will therefore be strongly shielded and shifted to very low frequencies hence the peak at 94 ppm. The last quaternary carbon, —CN, appears in the typical —CN range (109 ppm). A 13 C NMR prediction spectrum was obtained (ACD Labs prediction software, v. 10.04, December 2006) in order to compare the actual and predicted chemical shifts for C10′, C11′ and CN. The predicted chemical shifts were within 2 ppm for C10′ and C11′ and within 7 ppm for CN, hence validating our peak assignments based on NMR knowledge. The 1 H and 13 C NMR spectra of TFMPSPIM1 homopolymer were obviously similar to those of PIM-1 homopolymer due to their identical TTSBI monomer residue within the backbone. The additional signals arising from the new monomer were readily assigned in both 1 H and 13 C NMR with the help of 2D HMBC and HSQC. As before, the C—O carbon atoms C10′ and C12′ were assigned to high frequencies (137-141 ppm). The —CF 3 and C11′ were identified by their spin-couplings with the 19 F atoms (1JC-F=277 Hz, 2JC11′-F≈30 Hz). The 1 H and 13 C NMR spectra of the copolymer TFMPSPIM3 prepared from the monomer ratio 2 TTSBI:1 HFTPS:1 TFTPN are shown as the lower spectra in FIGS. 2 and 3 . As expected, these spectra display the same characteristics as the two fully characterized homopolymers PIM-1 and TFMPSPIM1. The specific low frequency (94 ppm) C11′ of PIM-1 and the specific quartet —CF 3 of TFMPSPIM1 are clearly visible in the 13 C NMR spectrum. Furthermore, the experimental ratio of intensity values for proton H-15, 16, 17 compared with H-6, 9 is exactly 5H: 8H, as expected for two repeat units of the TFMPSPIM3 copolymer. Finally, the 19 F NMR spectra (not shown) were collected for all three polymers. Only TFMPSPIM1 and TFMPSPIM3 showed a signal at ca. 56 ppm which is characteristic of a —CF 3 group. It is worthwhile mentioning that no aromatic F signal was observed. Thermal Analysis Thermal analyses for TFMPSPIM and PIM-1 were carried out and the results are summarized in Table 4. All the polymers have no discernable T g in the measured range of 50° C. to 350° C. TGA experiments showed that all the polymers have excellent thermal stabilities and the actual onset temperature of decomposition in nitrogen is above 350° C. There is also some trend between this temperature and monomer ratio. Generally, nitrile-containing polymers have high thermal stability, likely due to strong dipolar interactions. Table 4 shows that with increasing molar content of —CN in the polymers, the onset of thermal decomposition also increased. However, TFMPSPIM homopolymer and copolymers all showed very good thermal stability even after the replacement of nitrile with —CF 3 and pendant —SO 2 C 6 H 5 groups. TABLE 4 Thermal Properties of TFMPSPIM1-4 and PIM-1 Polymers T d (° C.) a T d (° C.) b T d5 (° C.) c RW (%) d TFMPSPIM1 352.8 430.3 437.7 59.15 TFMPSPIM2 357.6 450.9 458.5 62.82 TFMPSPIM3 368.3 463.5 468.3 63.04 TFMPSPIM4 370.9 482.8 486.8 64.79 PIM-1 429.6 492.6 495.4 68.17 a Actual onset temperature of decomposition. b Extrapolated onset temperature of decomposition measured by TGA. c Five percent weight loss temperature measured by TGA d Residue weight at 600° C. under N2. X-Ray Diffraction Studies Fractional free volume (FFV) increased with increasing nitrile content, suggesting that TFMPSPIMs with increasing —CF 3 and —SO 2 C 6 H 5 pendant groups pack interchain space more efficiently than PIM-1, as shown in Table 5. TABLE 5 Physical Properties of TFMPSPIM1-4 and PIM-1 from X-ray Studies d-space ρ V sp M V w V f Polymers Å g/cm 3 cm 3 /g g/mol cm 3 /mol cm 3 /g FFV TFMPSPIM1 6.30 1.214 0.82 618.62 304.4 0.180 0.22 TFMPSPIM2 6.34 1.196 0.84 565.90 285.0 0.185 0.22 TFMPSPIM3 6.50 1.156 0.87 539.55 275.4 0.206 0.24 TFMPSPIM4 6.60 1.089 0.91 513.20 265.7 0.237 0.26 PIM-1 6.88 1.063 0.94 460.48 246.3 0.244 0.26 The disruption in chain packing is validated by FFV and was calculated using the following relationship [Lee 1980]: V f =( V sp−1.3 V w ) FFV= V f /V sp where V f is the free volume, V sp is the specific volume. Membrane samples had a density in the range 1.06-1.21 g cm 3 , as determined by measurements of their weight in air and in ethanol. V w is the specific van der Waals volume calculated using the group contribution method of Bondi [Bondi 1964; van Krevelen 1990]. These assumptions are supported by the X-ray diffraction measurements shown in FIG. 5 , which reveal that all the polymers were amorphous. Three broad peaks were observed for all polymers. The peak at higher angles (4.9 Å) can be attributed to the chain-to-chain distance of space efficiently packed chains. The second peak, corresponding to more loosely packed polymer chains with a d-spacing of about 6.50 Å, is attributed to polymers maintaining their conformation with micropores between the chains [Weber 2007]. The exact d-spacing values were calculated from WAXD spectra by Bragg's law and are listed in Table 5. These values are consistent with the explanation of the free volume theory. The d-spacing of TFMPSPIM1 homopolymer is about 6.30 Å and it becomes larger with decreasing molar amounts of —CF 3 and —SO 2 C 6 H 5 groups in the main chain, suggesting that the —CF 3 and —SO 2 C 6 H 5 pendant groups affect the polymer chain packing and decrease polymer d-spacing, possibly by inter-chain space-filling. The third peak at a d-spacing of about 10 Å corresponds to the distance between the spiro-carbon atoms, which is about 10-15 Å for PIM-1 and is very similar to the calculated distances for TFMPSPIM1-4. The significance of the distance between the spiro-carbon centers is that the relatively planar rigid chain segments change direction and are skewed at these points, preventing efficient chain packing. Pure-Gas Permeation Properties A tradeoff relationship is usually observed between permeability (P) and ideal selectivity (α) for common gases in glassy or rubbery polymers, i.e., higher permeability is gained at the cost of lower selectivity and vice versa. Upper bound performance lines for the relationship between gas permeability and selectivity have been proposed by Robeson [Robeson 1991]. Pure-gas permeability coefficients (P) were measured on dense films (PIM-1, TFMPSPIM1-4) for O 2 , N 2 , and CO 2 and a summary of these P values and ideal selectivities for various gas pairs are shown in Table 6. As can be seen in Table 6, TFMPSPIM1-4 were significantly more selective than PIM-1 for all gases. TABLE 6 Gas Permeabilities and Ideal Selectivities of TFMPSPIM1-4 and PIM-1 P (Barrer a ) Selectivity α b Polymers O 2 N 2 CO 2 O 2 /N 2 CO 2 /N 2 TFMPSPIM1 156 33 731 4.7 22 TFMPSPIM2 308 75 1476 4.1 20 TFMPSPIM3 561 158 2841 3.6 18 TFMPSPIM4 737 217 3616 3.4 17 PIM-1 1133 353 5366 3.2 15 PIM-1 [11] 370 92 2300 4.0 25 PIM-1 [24] 786 238 3496 3.3 14.7 a Permeability coefficients measured at 25° C. and 50 psig feed pressure. 1 Barrer = 10 −10 [cm 3 (STP) · cm]/(cm 2 · s · cmHg). b Ideal selectivity α = (Pa)/(Pb). Although the permeability of O 2 is reduced with increasing amounts of —CF 3 and —SO 2 C 6 H 5 groups, TFMPSPIM1-4 permeability/selectivity data points are all above the upper bound line reported by Robeson, as shown in FIG. 6 . FIG. 6 illustrates the trade-off between O 2 permeability and O 2 /N 2 selectivity of PIM-1, TFMPSPIM1-4 membranes relative to the Robeson upper bound line. ∇ is data from Budd et al. which are for measurements reported at 200 mbar (2.9 psia) feed pressure at 30° C. [Budd 2005b]. Δ is data from Staiger et al. which are for measurements reported at 4 atm (58.8 psia) feed pressure 35° C. [Staiger 2008]. In comparison with PIM-1, which was tested under the same conditions, TFMPSPIM1-4 have significantly higher O 2 /N 2 and CO 2 /N 2 selectivity. From a material and structural viewpoint, chain rigidity imparts increased selectivity but lower permeability, whereas greater interchain distance imparts higher permeability but lower selectivity. The —CF 3 and —SO 2 C 6 H 5 groups in TFMPSPIM1-4 are hidden within the spirocyclic main chain structure, which maintains its zigzag conformation. While these pendant groups do not increase FFV, they increase chain stiffness and likely have an effect of inter-chain space filling. Compared to data reported by Budd et al. for films cast from tetrahydrofuran and measured at low gas feed pressure, the pure-gas oxygen permeability of PIM-1 reported for the present invention (about 1,133 Barrer) is about 3-times higher, but with a reduction in oxygen/nitrogen selectivity from 4 to 3.2 (Table 6). However, data for the present invention is more consistent with that of Staiger et al; the pure-gas permeabilities and selectivities of a PIM-1 film made from methylene chloride are similar to our data for a chloroform-solution-cast PIM-1 film. The gas permeation properties of highly rigid glassy polymers depend strongly on film formation protocols, such as casting solvent type and drying conditions [Moe 1988]. Molecular Modeling Conformational analysis of TFMPSPIM1 and PIM-1 was modeled with three repeat unit lengths to study the effect and distribution of —CF 3 and —SO 2 C 6 H 5 on chain geometry and steric interaction. The calculation results of geometry optimization with energy minimization using the AMBER method provides a visualization of major conformational changes occurring in the polymers, as shown in FIG. 7 . The chains of PIM-1 homopolymer containing —CN side groups, shown for comparison, have a relatively spiro-zigzag linear and regular ladder structure, which would lead to less chain packing. Compared with PIM-1, TFMPSPIM1 homopolymer showed a similarly unperturbed coil conformation. Although —CF 3 and —SO 2 C 6 H 5 are more bulky than the —CN group, they do not change the spiro-zigzag ladder chain. In addition, the rigidity of the ladder polymer chain with —CF 3 and —SO 2 C 6 H 5 groups can be enhanced by hindering bond distortion within the ladder chain; hence selective diffusion ability can be improved. Presumably, the pendant phenylsulfonyl group resides within the inter-chain free-volume and also acts to reduce permeability, while increasing selectivity. This is in good agreement with the gas permeation results. The molecular modeling result may help to explain why, as compared to PIM-1, the co-effects of TFMPSPIM improve their gas selectivity without overall loss of performance relative to the upper bound line. Example 8 Preparation and Characterization of PIM Ladder Polymers Containing Tetrahydroxy Dinaphthyl (THDN) Monomer In order to investigate the effect of the spatially twisted structure in the polymer chain, this example focuses on the synthesis of CoPIMs derived from TTSBI, TFTPN and THDN. The resulting copolymers were analyzed by GPC, TGA, nitrogen sorption, and gas permeabilities were measured. Scheme 3 gives an overview of the reaction scheme to prepare THDNPIM copolymers. Polymerization PIM copolymers derived from various feed ratios of TTSBI/THDN/TFTPN monomers were prepared by the aromatic nucleophilic polycondensation at 160° C. for 120 min in a manner similar to Example 5. Thus, into a 100 mL three-necked flask equipped with a magnetic stirrer, an argon inlet, and a Dean-Stark trap, with different ratio of monomers (THDN, TTSBI and TFTPN), anhydrous K 2 CO 3 , DMAc (monomers:DMAc=1:3.5 w:w) and toluene were added. The mixture was refluxed at 160° C. for 120 min, and then the viscous solution was poured into methanol. A yellow flexible threadlike polymer was obtained. The polymer product was dissolved in chloroform and reprecipitated from methanol. The resulting polymer was refluxed for several hours with deionized water, and dried at 100° C. for 48 h. The properties of the PIMs are summarized in Table 7. For comparison, PIM-1 was prepared under identical reaction conditions from TTSBI and TFTPN. It should be noted that PIM-1 prepared at this temperature for shorter reaction time (40 minutes) produced high molecular weight with narrow polydispersity. Table 7 contains the approximate molecular weights and polydispersities of the copolymers, as determined by GPC against polystyrene standards. A THDNPIM homopolymer is abbreviated as THDNPIM-100 and copolymers as THDNPIM-66, THDNPIM-50 and THDNPIM-33, where 66, 50 and 33 refer to the percentage of THDN/TFTPN (molar ratio) in the polymer chain. TABLE 7 Properties of the THDNPIM copolymer series and PIM-1 THDN TTSBI TFTPN Polymers (mol ratio) (mol ratio) (mol ratio) M n M w M w /M n THDNPIM-100 1 0 1 11,000 24,000 2.2 THDNPIM-66 2 1 3 13,000 31,000 2.3 THDNPIM-50 1 1 2 42,000 77,000 1.8 THDNPIM-33 1 2 3 116,000 273,000 2.3 PIM-1 (120 min) 0 1 1 58,000 625,000 10.8 PIM-1 (40 min) 0 1 1 55,000 85,000 1.6 Cyclic oligomers and cross-linking can be effectively reduced by using polycondensation reaction conditions of elevated temperature at 160° C. and high monomer concentrations. Toluene was also added to increase of solubility of tetraphenol salts and growing polymer chain. Within 40 min, the PIM-1 polymerization under optimum reaction conditions (160° C. and monomers:DMAc=1 mmol:2 mL) proceeded smoothly and no evidence of cross-linking was detected. It was observed that PIM-1 was prone to high molecular weight fractions and possible cross-linking when the reaction time exceeded 90 min under same conditions (polydispersity values up to 15), which resulted in limited M n . In the absence of toluene in reaction system, crosslinking occurred rapidly, within 30 min. As shown in FIG. 8 , there are several shoulder peaks in the high molecular weight region around the main peak of PIM-1 prepared at a reaction time of 120 min, indicating high molecular weight fractions and possible cross-linking. In this example, PIM-1 was prepared under the same conditions as THDNPIM. Table 7 shows that the polydispersities of THDNPIM copolymers is in the range of 1.8-2.3, compared to over 10 for PIM-1 prepared at the extended 120 min reaction time. It is interesting to note that as the molar ratio of TTSBI in THDNPIM copolymers is increased up to THDNPIM-50, a high M n can be obtained with a low polydispersity. At higher molar ratios beyond THDNPIM-50, M n values above 10,000 could still be obtained under these conditions, with low polydispersities. In the case of THDNPIM-33, a high molecular weight and low polydispersity was obtained, with no evidence of cross-linking. Thus, under the same reaction conditions (160° C., 120 min), molecular weight broadening and cross-linking are efficiently reduced by introducing a certain ratio of THDN into the polymer chain, and high molecular weight copolymer can be obtained. A plausible explanation is that TTSBI has a higher reactivity than THDN, and its concentration was decreased by introducing THDN into the copolymerization system, resulting in less cross-linking. On another hand, although high temperature and high concentration polymerization conditions were applied in this reaction, a high molecular weight homopolymer from TFTPN and THDN still could not be obtained, most likely due to steric hindrance induced by the spatially twisted dinaphthyl center. Although the M n of THDNPIMs-100 homopolymer is higher (M n =10,000 Da) than that previously reported [McKeown 2006a](M n =3,000), it is still insufficient to fabricate mechanically strong films for gas permeability measurements. FIG. 8 shows that as the molar content of THDN monomer increases, the low molecular weight of the resulting THDNPIM copolymers decrease. In addition, THDNPIM-100 and −66 have a significant amount of low molecular weight fractions. FIG. 9 shows that THDNPIM-100 (the homopolymer) consists mainly of cyclics and oligomers, which have two —F and two —OH groups at the polymer chain terminus. Molecular Modeling An insight as to why cyclization is favoured in chain step-growth of THDNPIM-100 was found by using the computer molecular modeling analysis. Energy minimized structural analysis of THDNPIM-100 and PIM-1 of four repeat units was performed by using HyperChem™ 7.0 software. In FIG. 10 , a visual indication of major conformational changes in the polymer chain units was obtained by the calculated results of geometry optimization with minimum energy using the AMBER method. Compared to the 90° zigzag chains observed for PIM-1, the THDNPIM-100 chain has a twist angle of about 60° for each unit. The reactive end-groups are situated in a conformation conducive to form cyclic species, since the chain is more foldable and compact. With the incorporation of increasing molar ratios of TTSBI comonomer, the rigid polymer chain conformations become more irregular and randomly spiral, which reduce the chances for end-group encounters, finally preventing the formation of cyclics. NMR Analysis All THDNPIM were fully characterized by 1 H and 19 F NMR spectroscopy. The 1 H spectra of THDNPIM-50 ( FIG. 11 ) were obviously similar to those of PIM-1 due to their identical TTSBI and TFTPN monomers part. The additional signals due to the THDN monomer were easily assigned in 1 H. Furthermore, the experimental ratio of intensity values for protons on the THDN aromatic rings compared with —CH 3 individually is exactly 10H:12H; as expected for two repeat units of the THDNPIM-50 copolymers. Finally, the 19 F NMR spectra (not shown) were collected for all three polymers. No aromatic F signal was observed. Thermal Analysis Thermal analyses results for the THDNPIM series and PIM-1 are compared in Table 8. All the polymers are amorphous, remaining glassy up to their decomposition temperatures (>430° C.), and have excellent thermal stabilities. No glass transitions were detected up to temperatures of 350° C. Actual onset temperatures of decomposition in nitrogen were in the range of 430-477° C. The dinaphthyl group imparts improved thermal stability, as shown by the increasing thermal stability with monomer molar ratio. TABLE 8 Thermal properties of the THDNPIM series and PIM1 Polymers T d (° C.) a T d (° C.) b T d5 (° C.) c RW (%) d THDNPIM-100 472.3 510.5 516.5 85 THDNPIM-66 466.9 509.6 519.2 79 THDNPIM-50 477.1 507.2 514.6 75 THDNPIM-33 465.9 504.3 509.5 73 PIM-1 (120 min) 430.1 492.6 495.4 68 a Actual onset temperature of decomposition b Extrapolated onset temperature of decomposition measured by TGA c Five percent weight loss temperature measured by TGA d Residue weight at 600° C. under N 2 Gas Transport Properties The porosity of the polymers was probed by nitrogen sorption BET analysis at 77 K. The THDNPIM were precipitated from chloroform into methanol, followed by extensive washing with methanol prior to sorption measurements. PIM-1 was tested under the same conditions and used as a reference material. Nitrogen sorption measurements on these polymers revealed that samples were microporous. As shown in Table 9, the adsorption average pore width of THDNPIM became slightly smaller with increasing molar content of THDN, with the exception of THDNPIM-100, and BET data changed from 729 m 2 ·g −1 for PIM-1 to 560 m 2 ·g −1 through the copolymer series. The polymer chain packing can be calculated by fractional free volume (FFV), which is listed in Table 9 [Bondi 1964; Van Krevelen 1990; Chern 1987]. The calculated FFV values of THDNPIM are almost identical to PIM-1, though the density of PIM-1 is somewhat lower than those of the THDNPIM series. Since the amount of pore deformation during the adsorption process should be considered, the reason for the difference may be that the flexibility of the dinaphthyl bond is significantly higher than that of the spirobisindane bond. As the interfacial energy in a microporous system is rather high, this can result in elastic pore closure by deformation of the dinaphthyl bond during testing. THDNPIM-100 also shows good microporosity, but it consists mainly of cyclics and oligomers and is thus not suitable for comparison with the other polymers. TABLE 9 Physical properties of THDNPIM and PIM-1 ρ, V sp , M, V w , V f , S BET , Polymers g/cm 3 cm 3 /g g/mol cm 3 /mol cm 3 /g FFV m 2 · g −1 THDNP-100 1.14 0.88 438.4 219.4 0.229 0.26 311 THDNP-66 1.12 0.89 445.8 228.4 0.224 0.25 560 THDNPIM-50 1.11 0.90 449.4 232.8 0.227 0.25 632 THDNPIM-33 1.09 0.92 453.1 237.3 0.239 0.26 709 PIM-1 (40 min) 1.06 0.94 460.5 246.3 0.244 0.26 729 In glassy or rubbery polymers, there is a trade-off relationship between gas permeability and selectivity for common gases. In general, higher permeability is gained at the cost of lower selectivity and vice versa. An upper bound performance for this trade-off relationship was proposed by Robeson [Robeson 1991]. Single gas permeability coefficients (P) were measured on polymer dense films of PIM-1 and THDNPIM-33 for O 2 , N 2 , He, H 2 , CO 2 and a summary of these P values and ideal selectivities (α) for various gas pairs are shown in Table 10. TABLE 10 Gas permeabilities and ideal selectivities of THDNPIM-33 and PIM-1 P (Barrer a ) α b Polymers O 2 N 2 He H 2 CO 2 O 2 /N 2 CO 2 /N 2 He/N 2 H 2 /N 2 THDNPIM-33 1030 271 1138 2601 5149 3.8 19 4.2 9.6 PIM-1 (120 min) 1560 547 1531 3364 7329 2.85 13.4 2.8 6.7 PIM-1 (40 min) 1133 353 1114 3042  5366 a 3.2 15 3.1 8.6 a Permeability coefficients measured at 25° C. and 50 psig pressure. 1 Barrer = 10 −10 [cm 3 (STP) · cm]/(cm 2 · s · cmHg) b Ideal selectivity α = (P a )/(P b ) THDNPIM-33 exhibited higher selectivity, coupled with some reduction in gas permeabilities, compared with PIM-1. The overall permeability/selectivity performance combines to exceed the Robeson upper bound line for O 2 /N 2 . From a material viewpoint, a shorter interchain distance imparts higher selectivity but lower permeability. In this case, THDN units shorten the distance between contorted centers, while maintaining a zig-zag structure, hence selectivity increased. Molecular modeling analysis indicates that gas permeabilities for THDNPIM-33 were not excessively reduced, even though the THDN structure is more compact and has a shorter distance between contorted centers and smaller twist angle. FIG. 10 shows that PIM-1 and THDNPIM-100 have similarly unperturbed zig-zag coil structures when viewed from ‘x’ and ‘y’ axes perspective. The angle at the spatially twisted dinaphthyl center in THDNPIM-100 (approximately 60°) is considerably smaller than that at the spirobisindane center in PIM-1 (approximately 90°). When both polymers are compared from the ‘z’ axis perspective, PIM-1 has an offset-linear conformation, whereas THDNPIM-100 has a zig-zag structure. This suggests that THDNPIM-100 is potentially even more contorted than PIM-1, which could result in less efficient chain packing. The addition of THDN units into copolymers would also have the same effect. This is in good agreement with the gas permeability results. Although the distance between the twisted dinaphthyl units is shorter and the kink angle is smaller than PIM-1, there was little apparent change in the interchain spacing throughout the THDNPIM copolymer series, as shown by FFV (Table 9). BET data shows that the surface area of the THDNPIM-33 copolymer is similar to PIM-1, and as the molar content of THDN increases in the copolymer, surface area decreases. Increasing the molar content of THDN also increases the amorphous nature of the copolymer, as shown by the disappearance of peaks in the X-ray diffraction measurements in FIG. 13 . FIG. 12 shows the gas permeability/selectivity trade-off plot for the O2/N2 gas pair in relation to the Robeson upper-bound. The V symbols show previous data reported by Budd et al. and by Staiger et al., for PIM-1. The data from Budd et al. [Budd 2005b] was reported at 200 mbar (2.90 psia) feed pressure at 30° C. The data from Staiger et al. [Staiger 2008] was reported at 4 atm (58.8 psia) feed pressure 35° C. Compared to data reported by Budd et al. for films cast from tetrahydrofuran and measured at very low gas feed pressure, the oxygen permeability of chloroform-cast films of PIM-1 (reaction for 120 min, high polydispersity material) reported herein (about 1,560 Barrer) is about 4-times higher, but with a reduction in oxygen/nitrogen selectivity from 4.0 to 2.8. Also shown in FIG. 12 is comparative PIM-1 data for PIM-1 produced at a reaction time of 40 min (low polydispersity). The disparity in results arises as the gas permeation properties of highly rigid glassy polymers depend strongly on film formation protocols, such as casting solvent type and drying conditions. As shown in Table 10 and FIG. 12 , the THDNPIM-33 copolymer, had an excellent combination of properties and was significantly more selective for gases/N 2 than PIM-1. The selectivity coupled with high permeability combines to exceed the Robeson upper-bound line for O 2 /N 2 . The results indicate that THDM can be incorporated as a comonomer for the synthesis of high molecular weight PIMs and tune gas permeability, selectivity and other properties of PIM copolymers. Example 9 Preparation and Characterization of PIM Ladder Polymers Containing Disulfone-Based Monomers (BSPIMs) This example focuses on the synthesis of new PIMs derived from sulfone monomers of Example 3. The effect of the sulfone side groups on microporosity for gas permeation behavior is investigated. The new PIM copolymers were prepared from three different tetrafluoro disulfone monomers (Scheme 4), such that the resulting PIM copolymer contains bulky, rigid groups. The disulfone-based PIMs present a new class of microporous polymers, and the structures, synthesis, physical properties, including the gas separations properties of this new class of PIMs are reported in this example. Monomer Synthesis The synthesis of disulfone monomers comprised two steps: aromatic nucleophilic substitution reaction and oxidation. Different from the known procedures [Kulka 1959; Robson 1963; Langille 1972], the sodium thiolate and pyridine mixture was added dropwise to hexafluorobenzene at −20° C. instead of adding hexafluorobenezene into sodium thiolate and pyridine mixture at reflux temperature (above 115° C.). Hexafluorobenzene easily reacts with thiol groups under basic conditions by a aromatic nucleophilic substitution reaction, especially at an elevated temperature. Even at room temperature, the addition of more than a two molar ratio of hexafluorobenzene to sodium thiolate still resulted in the formation of 1,4-difluoroterathiobenzene compounds. According to the modified synthesis method, the side reactions were successfully avoided and three dithioether monomers were obtained in high yield. It was also found that the oxidation of thio groups was not complete by using excess H 2 O 2 in heterogeneous acetic acid suspension at 100° C. for 1 hour. After 1 hour oxidation, only 20-30% thio groups were oxidized (observed from 1 H NMR spectra), which is different from the previous work [Robson 1963]. In general, the oxidation of dithio compounds is completed only after at least 24 h at 100° C. due to the poor solubility of partially oxidized compounds. TFBESB was oxidized without prior purification of the dithio compound, because the resulting disulfone monomer is more easily purified by recrystallization. Polymerization In general, BSPIMs-100, BSPIMs-50 and BSPIMs-33 were synthesized by copolymerization of TTSBI, TFTPN, and disulfone monomers (suffixes -100, -50, and -33 refer to disulfone to TTSBI ratio, i.e. monomer molar ratios 1:0:1; 2:1:1; 3:2:1) using a procedure similar to that of PIM-1 in Example 5. Thus, into a 100 mL three-necked flask equipped with a magnetic stirrer, an argon inlet, and a Dean-Stark trap, TFTPN, TTSBI and disulfone monomers, anhydrous K 2 CO 3 , DMAc, and toluene were added. The mixture was refluxed at 160° C. for 40-60 min and the resulting viscous polymer solution was precipitated into methanol. A yellow flexible threadlike polymer was obtained. The polymer product was dissolved into chloroform and reprecipitated from methanol. The resulting polymer was refluxed for several hours with deionized water, and dried at 100° C. for 48 h. Three series of ladder BSPIMs containing disulfonyl groups and —CN groups were prepared via the SNAr polycondensation described above using various feed ratios of TTSBI/TFTPN/disulfone monomers. The compositions and molecular weights of the polymers are listed in Table 11. The homopolymers are referred to as BSPIMs-100 and the copolymers are identified as BSPIMs-50, and BSPIMs-33, where PIM stands for polymer of intrinsic microporosity, BS stands for disulfonyl groups, and 50 and 33 represents the percentage of disulfone monomer/TTSBI (molar ratio) in the copolymers. TABLE 11 Compositions and molecular weights of BSPIM1-3 and PIM-1 Disulfone TTSBI monomer TFTPN Polymers (molar ratio) (molar ratio) (molar ratio) M n M w M w /M n BSPIM1-100 1 1 a 0 66,000 413,000 6.2 BSPIM1-50 2 1 a 1 63,000 453,000 7.1 BSPIM1-33 3 1 a 2 43,000 187,000 4.3 BSPIM2-100 1 1 b 0 58,000 625,000 10.8 BSPSM2-50 2 1 b 1 46,000 350,000 7.6 BSPIM2-33 3 1 b 2 41,000 84,000 2.1 BSPSM3-100 1 1 c 0 49,000 478,000 9.7 BSPIM3-50 2 1 c 1 52,000 421,000 8.1 BSPIM3-33 3 1 c 2 95,000 489,000 5.1 PIM-1 1 0   1 58,000 193,000 3.3 a monomer (a) in Scheme 4 b monomer (b) in Scheme 4 c monomer (c) in Scheme 4 According to the polycondensation reaction mechanism for poly(arylene ether)s, high temperature and high concentration should be favorable for increasing the solubility of phenoxide salt and growing polymer chain, hence the appearance of cyclic oligomers and crosslinked structures could be effectively reduced. The polymerizations of PIM-1 and related PIM copolymer structures (TFMPSPIMs) are disclosed herein above using high monomer concentrations (>25% wt) and at elevated temperatures (e.g. 160° C.). Excess toluene is introduced into the reaction not only to remove water, but also to provide solubility enhancement of the polymer. The reactions proceed smoothly and no evidence of crosslinking occurred. In contrast, the polycondensation of BSPIMs of this example are different from PIM-1 and TFMPSPIMs. According to the aromatic nucleophilic substitution reaction, there are two main factors influencing the substitution occurring in the aromatic system: (i) electronic activation and deactivation; and, (ii) steric deactivation. In general, it can be assumed that every substituent ortho- to the substitution site has some steric effect on the reaction rate. However, for the majority of the data reported before, the electronic effect of the electron donating or withdrawing group appears to be far more pronounced than the steric effect [Bunnett 1951]. It is well known that electron withdrawing groups have different electronic activation, in the sequence of —SO 2 R>—CF 3 >—CN [March 1970]. Because PIMs have a rigid ladder structure, which is different from linear flexible polymers, the steric deactivation effect may become important. In the first substitution reaction (I) shown in FIG. 14 , wherein a phenoxide nucleophile displaces a fluorine atom, the steric effect may not be obvious because the electrophile can attack perpendicular to the ring. Comparing three tetrafluoro-monomers, the initial substitution reactions will occur at the ortho-activated fluorine atom (atom 1) near —SO 2 R or —CN groups. When the second substitution reaction (II) forms the dibenzodioxane-based structure, the Ar-O—K + must attack the fluorine atom (atom 2) on the same side, from the horizontal direction, resulting in a quasi-planar dioxane ring. Therefore, the steric effects may become significant for dioxane ring formation in PIMs. If the electron withdrawing groups are not too sterically bulky, such as —CN and —CF 3 , the dibenzodioxane ring structure will be formed relatively easily. On the other hand, —SO 2 R is large enough to prevent electrophilic attack efficiently from the horizontal direction. Hence, under the high concentration reaction conditions used, after substitution reaction (I) occurs, there may be a competing substitution reaction (I) (perpendicular direction) on atom 1 of another monomer rather than the desired dibenzodioxane ring formation brought about by substitution reaction (II) (horizontal direction) on atom 2 of the same monomer. However, if reaction conditions are used whereby the concentration of disulfone monomer is low, dibenzodioxane ring formation is more likely to occur after the initial substitution reaction (I) due to the dilution effect. Meanwhile the reactivity of comonomer TFTPN is not as high as the disulfone-based monomers. Hence, with a progressively decreasing molar ratio of disulfone-based monomer to TTSBI, polydispersity is reduced, as observed by GPC. The GPC curves of BSPIMs-100 (not shown) reveal several shoulder peaks in the high molecular weight region along with the main peak. A minor gel fraction indicated that some crosslinking had occurred during the reaction. With decreasing ratios of disulfone-based monomers, only negligible gel formation was observed. The M n of all three BSPIMs-33 copolymers (Table 11) are above 41,000 Da and the polydispersity indices are in the range of 2-5. Although the polydispersity indices of BSPIMs-33 are somewhat higher than typical PIM-1 and PSTFPIM obtained under the same conditions, the quality of the copolymers is still high enough to provide solution-cast robust free-standing films for gas permeability measurements. NMR Analysis All three BSPIMs-50 were fully characterized by 1 H and 19 F NMR spectroscopy. The 1 H spectra of BSPIMs-50 were obviously similar to those of PIM-1 due to their identical TTSBI and TFTPN monomer content. The additional signals due to the different disulfone monomer were easily assigned in 1 H NMR. Furthermore, the experimental ratio of intensity values for aromatic protons H-8, 11 or 13 compared with aliphatic protons H-2,3 was found to be exactly as expected; for example, the spectra of the BSPIM-50 displayed in FIG. 15 all had proton ratios of exactly 4H:8H per repeat unit. A three-dimensional representation of the PIM polymer structures explains better what is observed in 1 H NMR spectroscopy. In 3-D it is clear that one of the methyl groups is within very close proximity of H-5 and therefore the electron cloud of the CH 3 group is shielding this proton, hence its very low chemical shift (6.4 ppm) for an aromatic proton. From the H-4 perspective, the two methyl groups are more distant, hence no shielding and the higher chemical shift (6.8 ppm) is observed. This combines to explain why the methyl groups (H-1) do not appear as a singlet but as two singlets, because they are not equivalent in a 3-D representation. The same principle also applies to H-2 and H-3. Those same H-4 and H-5 protons appear at the same position for both PIM-1 and BSPIM3-50 because the pendant groups, —CN and —SO 2 CH 2 CH 3 respectively, are small and sufficiently distant from the aromatic protons that they have no effect on them. On the other hand, the two PIM polymers BSPIM1-50 and BSPIM2-50 have bulky pendant phenyl groups with aromatic annular effects (ring current). These groups will cause H-4 and H-5 to appear at different chemical shifts. Hence, multiple H-4 and H-5 signals appear for BSPIM1-50 and BSPIM2-50 but not for PIM-1 and BSPIM3-50. The 19 F NMR spectra (not shown) were collected for all BSPIMs homo- and copolymers. No aromatic F signal was observed. Thermal Analysis Thermal analyses for BSPIMs and PIM-1 were carried out and the results are summarized in Table 12. All polymers are amorphous and have no discernable T g up to their decomposition temperatures (>317° C.). TGA experiments showed that all polymers had excellent thermal stabilities and the actual onset temperature of decomposition in nitrogen ranged from 317-407° C. There was also some trend between the decomposition temperature and the monomer ratio. Generally, polymers with —SO 2 Ar groups have high thermal stability. However, the —CN side group can enhance the thermal properties due to strong dipolar interactions. With increasing the molar ratios of —CN groups in the BSPIMs, the onset of thermal decomposition also increased, as shown in Table 12. However, BSPIM homopolymers and copolymers all showed very good thermal stability even after the replacement of —CN with —SO 2 R groups. TABLE 12 Thermal properties of the BSPIM1-3 series and PIM-1 Polymers T d (° C.) a T d (° C.) b T d5 (° C.) c RW (%) d BSPIM1-100 346.5 421.2 421.5 53.5 BSPIM1-50 372.3 451.91 449.84 63.0 BSPIM1-33 407.7 475.2 484.67 63.7 BSPIM2-100 329.7 417.2 412.5 51.0 BSPIM2-50 361.8 447.29 447.65 59.0 BSPIM2-33 384.7 464.9 475.92 62.5 BSPIM3-100 304.0 357.1 357.9 40.0 BSPIM3-50 317.0 398.46 376.33 48.0 BSPIM3-33 362.9 423.9 434.92 61.5 PIM-1 429.6 492.6 495.4 68.0 a Actual onset temperature of decomposition b Extrapolated onset temperature of decomposition measured by TGA c Five percent weight loss temperature measured by TGA d Residue weight at 600° C. under N 2 X-Ray Diffraction Studies WAXD revealed that BSPIMs-100 were amorphous polymers. Two main broad peaks were observed for all polymers ( FIG. 16 ). According to Bragg's Law, the peak representing 4.9 Å might be attributed to chain-to-chain distance of space-efficiently packed chains. On the other hand, the second peak found at a d-spacing of approx. 6.5 Å corresponds to more loosely packed polymer chains [Weber 2007]. As shown in FIG. 16 , the d-spacing is 5.9 Å for BSPIM2 and 6.5 Å for PIM-1. It becomes larger with decreasing size of disulfonyl groups in the main chain, suggesting that different disulfonyl groups affect polymer chain packing. The increasing size of disulfonyl groups leads to lower FFV due to inter-chain space filling. Free Volume Analysis The fractional free volume (FFV) is calculated using the following equations: FFV=( V−V 0 )/ and V=M /ρ and V 0 =1.3 V w where V is the total molar volume of the monomer unit (cm 3 /mol), M is the molar mass (g/mol) of the monomer unit and ρ is the density of the film (g/cm 3 ), which is determined experimentally (determined by measurements of the weight in air and in the ethanol). V 0 is the volume occupied by the chains (cm 3 /mol). V 0 is assumed to be impermeable for diffusing gas molecules. V w is the Van der Waals volume calculated using the group contribution method of Bondi [Bondi 1964, Van Krevelen 1990; Lee 1980]. According to Bondi, a good approximation of relation between V 0 and V w is given by the last equation and the results are given in Table 13. The FFV varied from a minimum of 0.09 for BSPIM2-100 to a maximum of 0.26 for PIM-1. The FFV of BSPIMs-33 is around 0.20. Compared to PIM-1, BSPIMs-33 pack more efficiently. TABLE 13 Physical properties of BSPIM1-3 series and PIM-1 ρ, V, M, V w , V − V 0 , Polymers g/cm 3 cm 3 /g g/mol cm 3 /mol cm 3 /g FFV BSPIM1-100 1.356 0.737 690.78 349.2 0.080 0.11 BSPIM1-50 1.207 0.829 575.63 297.8 0.156 0.19 BSPIM1-33 1.187 0.842 537.25 280.6 0.163 0.19 BSPIM2-100 1.369 0.730 750.83 382.4 0.068 0.09 BSPIM2-50 1.234 0.810 605.66 314.4 0.135 0.17 BSPIM2-33 1.198 0.835 557.26 291.7 0.155 0.19 BSPIM3-100 1.325 0.755 594.70 305.3 0.088 0.12 BSPIM3-50 1.214 0.824 527.59 275.8 0.144 0.18 BSPIM3-33 1.162 0.861 505.22 266.0 0.177 0.21 PIM-1 1.063 0.94 460.48 246.3 0.244 0.26 Pure-Gas Permeation Properties Single-gas permeability coefficients (P) for O 2 , N 2 , CO 2 were determined at 25° C. for dense polymer films (PIM-1, BSPIMs-33) and a summary of these P values and ideal selectivities for various gas pairs are shown in Table 14. TABLE 14 Gas permeabilities and selectivities of BSPIM1-33, BSPIM2-33, BSPIM3-33 and PIM-1 P (Barrer a ) α b Polymers O 2 N 2 CO 2 O 2 /N 2 CO 2 /N 2 BSPIM1-33 322 88 1408 3.7 16 BSPIM2-33 216 52 1077 4.2 20.7 BSPIM3-33 369 93 2154 3.9 23 PIM-1 1133 353 5366 3.2 15.2 a Permeability coefficients measured at 25° C. and 50 psig pressure 1 Barrer = 10 −10 [cm 3 (STP) · cm]/(cm 2 · s · cmHg) b Ideal selectivity α = (Pa)/(Pb) In comparison with PIM-1, the newly synthesized BSPIMs-33 exhibited higher selectivity, coupled with reductions in gas permeabilities. The selectivities for O 2 /N 2 and CO 2 /N 2 were in the range of 3.7-4.2 and 16-23, respectively. These results agree with the general tendency for gas permeation through polymer membranes, i.e. higher O 2 and CO 2 permeability is gained at the cost of lower selectivity and vice versa. Robeson proposed upper bound performance lines for this trade-off relationship between permeability and selectivity [Robeson 1991]. It is especially noteworthy that the O 2 permeation data of BSPIMs-33 were all positioned above Robeson's upper bound line. The high permeability and selectivity of O 2 and CO 2 of the BSPIMs-33 polymers can be ascribed to the presence of both nitrile groups, which are sufficiently polar, and disulfone groups, which are bulky. While these pendant groups do not increase the FFV or reduce chain packing, they increase chain stiffness and likely have an effect of inter-chain space filling, which results in an increase in selectivity. On the other hand, the permeability decreases by enlarging the size of pendant groups on PIMs. The three disulfone groups have different effects on space filling and interchain packing. The permeability and selectivity of PIMs can be tuned by the size of pendant groups. For example, BSPIM3-33 has the best combination of permeability coupled with selectivity for O 2 /N 2 and CO 2 /N 2 among the three BSPIMs-33. Molecular Modeling Molecular modeling analyses of BSPIMs-100 and PIM-1 with two repeat unit lengths were performed by using HyperChem™ 7.0 software for studying the effect on geometry and steric interaction of disulfonyl groups on the polymer chains. In FIG. 17 , a visual indication of major conformational changes in the polymers was obtained by the calculation results of geometry optimization with energy minimization using the AMBER method. The chains of PIM-1 with —CN pendant groups shown for comparison are relatively spiro-zigzag linear and regular ladder structure, which would lead to less chain packing. Compared with PIM-1, BSPIMs showed a similarly unperturbed coil conformation. Although disulfonyl groups are more bulky than the —CN group, they do not change the overall spiro-zigzag ladder chain structure and also do not take more intermolecular space. In addition the rigidity of the ladder polymers chain with disulfonyl groups can be enhanced by hindering bond distortions within the ladder chain, hence selective diffusion ability can be enhanced. The different pendant groups also act as the inter-chain space fillers with different size, which results in a decrease in permeability. The molecular modeling is in agreement with the gas permeability and selectivity data and help to explain the observed gas selectivity of BSPIMs-33 versus PIM-1. Example 10 Preparation and Characterization of PIM Ladder Polymers Containing 2,3,7,8-Tetrafluoro-5,5′,10,10′-Tetraoxidethianthrene Monomers (TOTPIMs) This example focuses on the synthesis of new PIMs derived from the 2,3,7,8-tetrafluoro-5,5′,10,10′-tetraoxidethianthrene (TFTOT) monomer of Example 4. New PIM copolymers (designated TOTPIMs) were prepared from the monomer in accordance with Scheme 5. Monomer Synthesis The 2,3,7,8-tetrafluoro-5,5′,10,10′-tetraoxidethianthrene (TFTOT) monomer is a novel compound. It is somewhat analogous to 2,3,7,8-tetrachloro-5,5′,10,10′-tetraoxidethianthrene listed by McKeown [McKeown 2006a] but McKeown did not report any polymers made from the tetrachloro analogue. TFTOT has superior reactivity than the tetrachloro analogue, the tetrachloro analogue being a poor choice for polycondensation reactions. Polymerization In general, TOTPIMs were synthesized by copolymerization of TTSBI, TFTOT and TFTPN (suffixes -100, -66, -50, -33, -25 and -20 refer to TTSBI:TFTOT:TFTPN ratio, i.e. monomer molar ratios 1:1:0, 3:2:1, 2:1:1, 3:1:2, 4:1:3 and 5:1:4, respectively) using a procedure similar to that of PIM-1 in Example 5 and as illustrated in Scheme 5. The homopolymer of TTSBI with TFTOT represented by TOTPIM-100 was not successfully isolated due to poor solubility of the polymer. Thus, into a 100 mL three-necked flask equipped with a magnetic stirrer, an inert gas inlet, and a Dean-Stark trap, TFTPN, TTSBI and TFTOT monomers, anhydrous K 2 CO 3 , DMAc and toluene were added. The mixture was refluxed at 160° C. for 40-60 min, and the resulting viscous polymer solution was precipitated into methanol. A yellow flexible threadlike polymer was obtained in most cases. The polymer product was dissolved into chloroform and reprecipitated from methanol. The resulting polymer was refluxed for several hours with deionized water, and dried at 100° C. for 48 h. Molecular weights and monomer ratios are provided in Table 15. TABLE 15 Compositions and molecular weights of TOTPIMs TTSBI TFTOT TFTPN Polymers (molar ratio) (molar ratio) (molar ratio) M n M w M w /M n TOTPIM-100 1 1 0 — — — TOTPIM-66 3 2 1 15,200 32,000 2.1 TOTPIM-50 2 1 1 41,000 89,000 2.2 TOTPIM-33 3 1 2 30,000 70,000 2.3 TOTPIM-25 4 1 3 42,000 84,000 2.0 TOTPIM-20 5 1 4 40,000 81,000 2.1 REFERENCES The contents of the entirety of each of which are incorporated by this reference. Alsop D J, Burdon J, Tatlow J C. (1962) J. Chem Soc. 1801-1805. Aoki T. (1999) Prog. Polym. Sci. 24, 951-993. Banerjee S, Maier G, Burger M. (1999) Macromolecules. 32, 4279-4289. Bock H, Stein U, Rittmeyer P. (1982) Angew Chem. 94, 540-541. Bondi A. (1964) J. Phys. Chem. 68, 441-451. Budd, P M, Ghanem B, Msayib K, McKeown N B, Tattershall C J. (2003) Mater. Chem. 13, 2721-2726. Budd P M, Ghanem B S, Makhseed S, McKeown N B, Msayeb K J, Tattershall C E. (2004a) Chem. Commun. 230-231. Budd P M, Elabas E S, Ghanem B S, Makhseed S, McKeown N B, Msayeb K J, Tattershall C E, Wong D. (2004b) Adv. Mater. 16, 456-459. Budd P M, McKeown N B, Fritsch D J. (2005a) Mater. Chem. 15, 1977-1986. Budd P M, Msayeb K J, Tattershall C E, Reynolds K J, McKeown N B, Fritsch D. (2005b) J. Membr. Sci. 251, 263-269. Budd P M, Butler A, Selbie J, Mahmood K, McKeown N B, Ghanem B, Msayib K, Book D, Walton A. (2007) Phys. Chem. Chem. Phys. 9, 1802-1808. Bunnett J F, Zahler R E. (1951) Chem. Rev. 49, 273-412. Carta M, Msayib K J, Budd P M, McKeown N B. (2008) Org. Lett. 10, 2641-2643. Chern R T, Sheu F R, Jia L, Stannett V T, Hopfenberg H B. (1987) J. Membr. Sci. 35, 103-115. Dai Y, Guiver M D, Robertson G P, Kang Y S, Lee□ K J, Jho J Y. (2004) Macromolecules. 37, 1403-1410. Dai Y, Guiver M D, Robertson G P, Kang Y S. (2005) Macromolecules. 38, 9670-9678. Davankov V A, Tsyurupa M P. (1990) React. Polym. 13, 27-42. Du N, Song J, Robertson G P, Pinnau I, Guiver M D, (2008) Macromol. Rapid Commun. 29, 783. George S C, Thomas S. (2001) Prog. Polym. Sci. 26, 985-1017. Ghanem B, McKeown N B, Harris K D M, Pan Z, Budd P M, Butler A, Selbie J, Book D, Walton A. (2007) Chem. Commun. 67-69. Ghanem B, McKeown N B, Budd P M, Fritsch D. (2008) Macromolecules. 41, 1640-1646. Kim T H, Koros W J, Husk G R, O'Brien K C. (1988) J. Membr. Sci. 37, 45-62. Kricheldorf H R, Lomadze N, Fritsch D, Schwarz G. (2006) J. Polym. Sci., Part A: Polym. Chem. 44, 5344. Kricheldorf H R, Fritsch D, Vakhtangishvili L, Lomadze N, Schwarz G. (2006) Macromolecules. 39, 4990-4998. Kulka M J. (1959) Org. Chem. 24, 235-237. Langille K R, Peach M E. (1972) J. Fluorine Chem. 407-414. Lee W M. (1980) Polym. Eng. Sci. 20, 65-79. Lee C L, Chapman H L, Cifuentes M E, Lee K M, Merrill L D, Ulman K L, Venkataraman K J. (1988) Membr. Sci. 38, 55-70. Maffei A V, Budd P M, McKeown N B. (2006) Langmuir 22, 4225-4229. Maier G. (1998) Angew. Chem. Int. Ed. 37, 2960-2974. March J. (1970) Advanced Organic Chemistry . New York: McGraw-Hill, p 253. Masuda T, Isobe E, Higashimura T, Takada K. (1983) J. Am. Chem. Soc. 105, 7473-7474. McKeown N B, Hanif S, Msayib K, Tattershall C E, Budd P M. (2002) Chem. Commun. 2782-2783. McKeown N B, Budd P M, Msayeb K J, Ghanem B S, Kingston H J, Tattershall C E, Makhseed S, Reynolds K J, Fritsch D. (2005) Chem. Eur. J. 11, 2610-2620. McKeown N B, Budd P M, Msayib K, Ghanem B. (2006a) United States Patent Publication US 2006-0246273 published Nov. 2, 2006. McKeown N B, Gahnem B, Msayib K J. Budd P M, Tattershall C E, Mahmood K, Tan S, Book D, Langmi H W, Walton A. (2006b) Angew. Chem. Int. Ed. 45, 1804-1807. McKeown N B, Budd P M. (2006c) Chem. Soc. Rev. 35, 675-683. McKeown N B, Budd P M, Book D. (2007) Macromol. Rapid Commun. 28, 995-1002. Miyatake K, Hill A R, Hay A S. (2001) Macromolecules. 34, 4288N. Moe M B, Koros W J, Hoehn H H, Husk G R. (1988) J. Appl. Polym. Sci. 36 1833-1846. Nagai K, Masuda T, Nakagawa T, Freeman B D, Pinnau I. (2001) Prog. Polym. Sci. 26, 721-798. Pandey P, Chauhan R S. (2001) Prog. Polym. Sci. 26, 853-893. Paul D R, Yampolski Y. (1994) In Polymeric gas separation membranes . CRC Press: London, p 107. Robeson L M. (1991) J. Membr. Sci. 62, 165-185. Robeson L M, Burgoyne W F, Langsam M, Savoca A C, Tien C F. (1994) Polymer. 35, 4970-4978. Robson P, Smith T A, Stephens R, Tatlow J C. (1963) J Chem. Soc. 7, 3692-3703. Shibuya N, Porter R S. (1992) Macromolecules. 25, 6495. Staiger C L, Pas S J, Hill A J, Cornelius C. (2008) J. Chem. Mater. 20, 2606-2608. Stern S A. (1994) J. Membr. Sci. 94, 1-65. Tanaka K, Okano M, Toshino H, Kita H, Okamoto K I. (1992) J. Polym. Sci., Polym. Phys. 30, 907-914. Toda F, Tanaka K, Iwata S. (1989) J. Org. Chem. 54, 3007-3009. Tsyurupa M P, Davankov V A. (2002) React. Funct. Polym. 53, 193-203. Urban C, McCord E F, Webster O W, Abrams L, Long H W, Gaede H, Tang P, Pines A. (1995) Chem. Mater. 7, 1325-1332. van Krevelen D W. (1990) In Properties of Polymers: Their Correlation with Chemical Structure; Their Numerical Estimation and Prediction from Additive Group Contributions . Elsevier: Amsterdam, Netherlands. Weber J, Su Q, Antonietti M, Thomas A. (2007) Macromol. Rapid. Commun. 28, 1871-1876. Webster O W, Gentry F P, Farlee R D, Smart B E. (1992) Makromol. Chem., Macromol. Symp. 54(55), 477-482. Wood C D, Tan B, Trewin A, Niu H J, Bradshaw D, Rosseinsky M J, Khimyak Y Z, Campbell N L, Kirk R, Stockel E, Cooper A I. (2007) Chem. Mater. 19, 2034-2048. Yu A, Shantarovich V, Merkel T C, Bondar V I, Freeman B D, Yampolskii Y. (2002) Macromolecules. 35, 9513-9522. Other advantages that are inherent to the structure are obvious to one skilled in the art. The embodiments are described herein illustratively and are not meant to limit the scope of the invention as claimed. Variations of the foregoing embodiments will be evident to a person of ordinary skill and are intended by the inventor to be encompassed by the following claims.

A polymer of formula (I): where: n is an integer from 10 to 5,000; m is an integer from 10 to 5,000; Ar1 and Ar3 are the same or different and are residues derived from a tetra-hydroxy aromatic monomer, the tetra-hydroxy aromatic monomer being wherein R is the same or different and is H or a C 1 -C 8 alkyl, C 2 -C 8 alkenyl or C 3 -C 8 cycloalkyl group; and, Ar2 and Ar4 are the same or different and are residues derived from a tetra-halogenated aromatic monomer, the tetra-halogenated aromatic monomer being wherein X is F, Cl or Br, and R1 and R2 are the same or different and are wherein y is an integer from 1 to 8; with the proviso that when Ar1 is the same as Ar3 and Ar2 is the same as Ar4, R1 and R2 are not both —CN is useful as a material for gas separation, vapor separation, adsorbents or catalysis.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to tampon wrap and, more particularly, to a tampon applicator wrap having an easy open, detachable top. With today's active woman and the need to change tampons frequently during the menstrual period, it is desired to provide tampons having applicators that are readily and conveniently carried on ones person. Therefore, it is necessary to provide a wrap that protects the tampon and tampon ejection end of the applicator from being soiled. Accordingly, the wrap must be made of a material that is strong enough so as not to inadvertently open. However, it is also necessary that the user have the ability to open the wrap when desired without, of course, soiling the tampon ejection end of the applicator. It is desired that such a wrap also provide for the disposal of the used tampon applicator. It is also desired that such a wrap be inexpensively produced and, therefore, that it be made from readily available materials. For a two piece compact tampon applicator, it is highly desirable that the wrap permit the user to assemble the applicator without touching the tampon ejection end of the applicator. 2. Description of the Prior Art The use of material for a tampon wrap which is strong enough to prevent inadvertent opening is known. For example, the tampons presently marketed by the assignee of the present application under the registered trademark Playtex (of Playtex Apparal, Inc.) use a polypropylene wrap. The end seals of this wrap are described in U.S. Pat. No. 4,617,781 to Ingersoll, et al, which issued on Oct. 21, 1986, and is also owned by the assignee of the present application. The polypropylene wrap is specifically a voided polypropylene film wrap. In order to open the wrap, there is provided a row of notches at the each end seal of the wrap as described in the Ingersoll, et al patent. Further, the wrap is virtually always destroyed when opened thereby making it unavailable for disposing of the used tampon applicator. The use of a weakening line or a scoring or the like to open a package is known. For example, U.S. Pat. No. 3,625,351 to Eisenberg, which issued on Dec. 7, 1971, is directed to a sterilized tearable bag made of polyvinyl chloride having a pair of aligned striations comprising a multitude of closely spaced grooves or indentations which facilitate tearing of the bag. Also, U.S. Pat. No. 3,186,628 to Rohde, which issued on June 1, 1965, is directed to a package for a syringe formed from various materials, including polypropylene, which package has opposed coinciding score groove lines which rupture by grasping the package at its opposed ends. Further, U.S. Pat. No. 1,848,119 to Fairchild, which issued on Mar. 8, 1932, is directed to a wrapper for toilet paper which has a weakened line formed by scoring; U.S. Pat. No. 1,864,968 to Weiner, which issued on June 28, 1932, is directed to a carton having a circumferential line formed by scoring or perforations to enable the carton to separate; and U.S. Pat. No. 1,965,353 to Nones, which issued on July 3, 1934, is directed to a wrapper for a bottle which has a weakening line formed by scoring. Still further examples of the use of a weakening line or a scoring or the like to open a package are U.S. Pat. No. 3,197,120 to Sparks, which issued on July 27, 1965, for a clamshell envelope; U.S. Pat. No. 3,216,562 to Lockwood, which issued on Nov. 9, 1965, for an easy-open capsule; U.S. Pat. No. 3,179,327 to Burton, et al., which issued on Apr. 20, 1965, for a film tear line for plastic film material; U.S. Pat. No. 2,195,740 to Salfisberg, which issued on Apr. 2, 1940, for separating bags from a row of formed bags; and U.S. Pat. No. 2,057,121 to Trevellyan, which issued on Oct. 13, 1936, for packaging for fibrous material. Heretofore, while there have been tampon wraps such as the Playtex Family Products, Inc. wrap, mentioned above, which is the subject of U.S. Pat. No. 4,617,781 to Ingersoll, et al, also mentioned above, there has not been a tampon wrap which achieves all of the desired objectives set forth above. For example, U.S. Pat. No. 4,648,513 to Newman, which issued on Mar. 10, 1987, is directed to a package for sanitary napkins, and also a tampon, which package can also turn into a disposal container or wrap for the used sanitary napkin or tampon. Specifically, the package or container, which is made from a sheet of material such as polypropylene or polyethylene, has a pair of perforation lines that form tear lines basically at both ends of the wrap past the enclosed tampon. There is also included a flap which is used to reseal the package after the used article is placed therein. Significantly, this package, which is used for regular sized or non-compact applicators, does not address the problem of providing for selected grasping of the applicator without touching or otherwise soiling the tampon ejection end of the applicator. Also, because of the addition of the flap, this package is relatively more expensive. Further, because the tear lines are beyond the enclosed product a great deal of wrap material is wasted making this wrap even more costly and, moreover, the overall length of the applicator with package is increased. SUMMARY OF THE INVENTION It is an object of the present invention to provide a tampon applicator wrap which easily opens at a predetermined location. It is another object of the present invention to provide such a tampon applicator wrap which can be used for any type of tampon applicator. It is still another object of the present invention to provide such a tampon applicator wrap which is strong enough so as not to inadvertently open. It is yet another object of the present invention to provide such a tampon applicator wrap which is easily opened by the user when desired. It is still yet another object of the present invention to provide such a tampon applicator wrap which opens to form two discrete portions with at least one portion retaining its integrity so that it can also be used to dispose of the tampon applicator after use. It is yet still another object of the present invention to provide such a tampon applicator wrap which opens at a predeterimed location thereby virtually assuring that the user shall not touch or otherwise soil the tampon ejection end of the applicator. To the accomplishments of the foregoing objects and advantages, the present invention, in brief summary, comprises a wrap for a tampon applicator having a first or barrel member and a second or plunger member. The wrap comprises a hollow body for containing the tampon applicator therein, and a score line located in a predetermined position on the body to separate the body into two discrete portions, preferably, in the vicinity of the junction of the first and second members of the tampon applicator. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and still other objects and advantages of the present invention will be more apparent from the following detailed explanation of the preferred embodiments of the invention in connection with the accompanying drawings wherein: FIG. 1 is a perspective view of the wrap of the present invention; FIG. 2 is a side view of the wrap of FIG. 1 with the top of the wrap separated from the body of the wrap; and FIG. 3 is a partial perspective view of the wrap of FIG. 1 turned ninety degrees with the top of the wrap separated from the body of the wrap. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings and, in particular, FIG. 1, there is provided a tampon applicator wrap generally represented by reference numeral 10. The wrap 10 is adapted to enclose therein a tampon applicator 20. The tampon applicator 20 shown in the figures of the present application includes a discrete barrel 22, which is adapted to contain a tampon therein, and a discrete plunger 28. The shown tampon applicator 20, which is the subject of a co-pending application Ser. No. 245,888, filed on even date, is representative of one of the preferred types of tampon applicators that can be contained within the tampon wrap 10 of the present application. However, it is understood that the tampon wrap 10 can be used for any sized and any type of tampon applicator, and can possibly even be used for a digital tampon. The wrap 10 includes a body which, when desired, separates into a main portion 12 and a top portion 14. The wrap 10 is formed from a flat sheet of polyproylene material. Polypropylene material is preferred since it is strong enough so as not to tear easily or inadvertently, and is resistant to transmission of water and odors. Further, polypropylene is heat sealable thereby making it easy to work with from a production standpoint and is relatively inexpensive. However, other materials which resist inadvertent tearing, such as polyethylene, may also be used. A particularly preferred polypropylene is voided film polypropylene which has air bubbles within the polypropylene film itself. By creating these air bubbles, the voided polypropylene is less dense than pure polypropylene which facilitates sealing of the wrap, yet retains all the desired properties discussed above. Such voided polypropylene is being sold under the trademark of Hercules R WT503 (Hercules is a registered trademark of Hercules Incorporated). Since polypropylene is a relatively strong or tear resistant material, it is generally understood that means should be provided to open the polypropylene wrap. Heretofore, a row of notches in the end seal have been provided to open a polypropylene wrap as described in U.S. Pat. No. 4,617,781, discussed above, which is incorporated herein by reference. In its initial or unopened state, shown in FIG. 1, the main portion 12 and the top portion 14 of the wrap 10 meet at a single line 16. Line 16 is a crush or score line that serves as a weakening area for subsequent separation of the main portion 12 from the top portion 14 to thus open the wrap. It is important that the score line 16 be a failure or crush line about the wrap which does not inadvertently open as one carries the wrapped tampon applicator. Specifically, the wrap 10, as shown in FIG. 1, includes a pair of end seals 17, 18 and a longitudinal or axial seal 19 which seals can be made in accordance with the teachings of U.S. Pat. No. 4,617,781 to Ingersoll, et al., discussed above. The pair of end seals 17, 18 are formed circumferentially on the wrap 10 in a plane basically perpendicular to the axial direction of the wrap 10. The score line 16 is also formed circumferentially on the wrap 10. The score line 16 is, preferably, formed in a plane which is basically parallel to the planes of the end seals 17, 18. Accordingly, a single score line is preferred because if two or more score line were provided, the wrap, especially between the score lines, may break into fragments when a user opens the wrap. FIG. 2 illustrates the wrap 10 after the top portion 14 has been separated from the main portion 12. The edge 13 of the main portion and the edge 15 of the top portion, which edges define the score line prior to separation, should be even, i.e. without the jaggedness which would otherwise accompany the tearing of a polypropylene wrap after separation. This construction assures that the wrap 10 will separate cleanly, i.e. in a straight line, into the main portion 12 and the top portion 14 so that the integrity of at least the main portion 12 is retained. Thus, the main portion 12, which remains substantially intact, can be used to store or otherwise dispose of the used tampon applicator 20. The score line 16 is formed when the film is in its flat state by passing the film between a pair of rollers with one roller being fitted with a blade and the other a flat portion or anvil. The score line is formed at ambient temperature. It has been found that score line 16 so formed requires a force of approximately 4 to 9 lbs. of pressure to be pulled apart. A preferred tampon applicator 20 for use in connection with the subject wrap 10 is illustrated in the FIGS. 1-3. However, the applicator can be used with any type and any size applicator. The tampon applicator 20 shown in FIGS. 1-3 is by way of illustration only. The applicator 20 has a discrete plunger 28 and a discrete barrel 22 with a petal tipped tampon ejection end 13 and an opposite or plunger receiving end 24 which, preferably, has fingergrips 25 on the exterior surface thereof. The tampon ejection end 23 is positioned in the closed end of the main portion 12 so that the plunger receiving end 24 is positioned towards and extends into the top portion 14 of the wrap 10. The score line 16 can be placed in any predetermined location on the wrap 10 with the exact criteria for determining the actual location varying depending on the type of applicator used in conjunction with the wrap 10. Nevertheless, the wrap, for all type applicators, should separate so as to provide for easy grasping and removal of the plunger from the wrap. When the wrap 10 is used with a conventional length tampon applicator, the wrap, upon separation, should expose a sufficient amount of the free end of the plunger to provide for easy grasping of the plunger such that the assembled tampon applicator can readily be removed from the wrap. For a compact tampon applicator, such as, for example, the tampon applicator 20 shown in FIGS. 1-3, the score line 16 is positioned at a predetermined location on the wrap so that upon separation of the main portion 12 from the top portion 14, as shown in FIGS. 2 and 3, the fingergrips 25 of the barrel 22 and one end 29 of the plunger 28 are exposed. Specifically, the score line 16 is positioned on the wrap 10 so that upon separation of the wrap a sufficient amount of the plunger is exposed to provide for easy grasping and removal of the plunger 28 from the wrap. Further, the score line 16 should also be positioned so that upon separation of the wrap 10 all or part of the fingergrips 25 of the barrel 22 are exposed to enable the user to readily align the plunger 28 with the barrel and, if desired, permit the user to grasp the fingergrips of the barrel to remove the assembled tampon applicator from the wrap 10. Therefore, the score line 16 should be positioned to expose an end of the plunger and the barrel 22 anywhere along the fingergrips 25, i.e. anywhere from where the fingergrips meet the remainder of the barrel 22 up to the edge of the plunger receiving end 24 of the barrel. In the embodiment shown in FIGS. 1-3, the score line 16 is positioned approximately in the same vertical plane where the fingergrips 25 meet the remainder of the barrel 22 of the tampon applicator 20 so that the user of the tampon applicator 20 can grasp the barrel anywhere along the entire axial extent of the fingergrips 25. In practice, the score line 16 shown in FIGS. 1-3 is placed at the predetermined location which normally is measured from one of the end seals 17, 18 of the wrap 10 an amount approximately equal to the length of the barrel of the applicator. For example, the barrel 22 of the applicator must be placed in the wrap 10 with sufficient axial space 30 in the wrap 10 between the end seals 17, 18 and the barrel 22 so that the barrel does not apply stress on the end seals. Nevertheless, it has been found that the axial extent of the non-fingergrip portion of the barrel 22 defines the approximate distance of the score line 16 from the end seal 17 of the body portion 12. Thus, for the two piece applicator shown in the figures, which has a non-fingergrip barrel portion of approximately two and one quarter inches, the distance of the score line 16 from the end seal 17 is approximately two and one quarter inches. (The distance of the score line 16 from the end seal 18 of the top portion 14 is approximately 1.65 inches +/-0.12 inches). To open the wrap 10, the user simply grasps the main portion 12 and the top portion 14 of the wrap 10 and pulls the wrap axially outward using approximately 4 to 9 lbs. of pressure. It is recommended that the user hold the main portion 12 of the wrap 10 between the thumb and the index finger of one hand and grasp, with the other hand, the top portion 14 of the wrap approximately at the end seal of the top portion. The user then snaps off the top portion 14 from the main portion 12. Once the main portion 12 has been separated from the top portion 14, the user can grasp the applicator at the predetermined location. In the case of a two piece portable tampon applicator, such as the side by side tampon applicator shown in FIGS. 1-3, which applicator requires assembly prior to use, the user grasps the exposed end 29 of the plunger 28, removes the plunger from the wrap and inserts the opposite end of the plunger into the plunger receiving end 24 of the barrel 22 while the barrel is held by the user in the main portion 12 of the wrap 10. For use with all sized applicators, the main portion 12 of the wrap 10 retains its integrity after separation from the top portion 14 of the wrap. The used tampon applicator can, therefore, be re-inserted into the main portion 12 of the wrap 10. Thus, the main portion 12 of the wrap provides a structure for discreet discarding of the used tampon applicator. For a conventional length applicator, the main portion 12 of the wrap 10 may include closure means (not shown). Specifically, the closure means is adapted to close the open end, or score line end, of the main portion 12 of the wrap 10 after the used tampon applicator is inserted therein. For all tampon applicators used with the wrap 10 of the present invention, the score line 16 is positioned on the wrap so that when the wrap opens only the desired portion of the applicator is exposed. Therefore, it can be virtually assured that the user will not contaminate the tampon ejection end 23 of the tampon applicator 20 since the wrap can prevent the user from soiling or contacting the tampon ejection end of the barrel 22. While the above wrap has been illustrated in connection with a two piece applicator in which the barrel houses the tampon, it can also be used with a two piece applicator in which the plunger component houses the tampon. Further, the wrap may even be used with a retractable one-piece applicator or a hinged or any other compact applicator. Moreover, the wrap can readily be used with a conventional length applicator. Having thus described the invention with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

There is provided a wrap for a tampon applicator having a first member and a second member. The wrap includes a hollow body for containing the tampon applicator therein, and a score line located at a predetermined position on the body to separate the body into two discrete portions in the vicinity of the junction of the first and the second members of the tampon applicator.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for treating fabrics inside a tumble dryer, particularly a device which is reusable. 2. The Related Art In the treatment of fabrics in a tumble dryer it is known to add one or more conditioning agents. For instance, for imparting a softening benefit to fabrics it is known from CA 1,005,204 to co-mingle fabrics in a tumble dryer with a flexible substrate carrying a normally solid fabric conditioning agent. The co-mingling of the fabrics with impregnated substrates requires the separation of the substrate from the fabrics after the completion of the tumble dryer treatment. Especially in using flexible substrates, this separation is often time-consuming in that the substrates cannot readily be located. Other disadvantages of such products include uneven product distribution following entanglement of the substrate with fabrics which can lead to greasy marks on fabrics (staining) and the tendency of such substrates to become positioned over the tumble dryer vent, thus giving virtually no benefit to the fabrics during a tumble drying cycle. Furthermore, these products are designed for single use only and therefore need to be replaced after every cycle. For overcoming these problems it has been suggested, for instance in GB 2,066,309 and U.S. Pat. No. 3,634,947, to use conditioner dispensing articles, comprising means for attachment of the substrate to the tumble dryer wall. Other proposals, such as for instance disclosed in GB 1,399,728 involve the use of separate means for attaching the conditioning article to the tumble dryer wall. EP-B-361593 concerns an alternative approach in which a fabric conditioning article comprises a combination of a substrate and a fabric conditioning composition, the substrate being a porous material with a specified void volume and cell count. The article of EP-B-361593 is designed to adhere to the tumble dryer wall. It is an object of the present invention to provide an improved device suitable for treatment fabrics in a tumble dryer. It is also an object to provide a device with improved delivery of the fabric treatment composition and reduced staining. SUMMARY OF THE INVENTION According to the present invention, there is provided a device for treating fabrics in a tumble dryer comprising: a reservoir for storing a fabric treatment composition and transfer means to expose the fabric treatment composition from the reservoir to airflow generated inside the tumble drier and/or to directly contact fabrics in the dryer, thereby transferring a portion of the fabric treatment composition into contact with fabrics in the tumble dryer during a tumble drying cycle; characterised in that the transfer means comprises compressed foam. With this arrangement, the foam takes less time to charge (fill up) with composition, and so is effective more quickly after initial installation. Also, with this arrangement, the foam is stiffened. Stiffening the foam reduces staining which would otherwise result from compression of the foam (and consequential over dosing of the composition) during the tumble drying cycle (as the rotating fabrics impact the foam). Foam compression also reduces the size of the pores within the foam and this enhances the transfer (by capillary action) of fluid composition to the whole foam surface via such pores, by improved capillarity. Otherwise, the fluid can flow under gravity to the lowermost portion/s of the foam and present excessive amounts on the surface, leading to staining. The compressed foam may be in the form of one or more layers. Preferably the foam layer is compressed prior to fitting in the device. Compression may be by any suitable process, and may use a combination of heat and pressure so as to effect a permanent compression of the foam. Preferably the compressed foam is a polyurethane foam and further preferably it is a polyester foam. Preferably the foam has a compression ratio of 8 or more, i.e. it has been compressed to ⅛ or less than its original thickness. However, other ratios such as 10, 12, 14 may be used. The initial (pre-compression) pore size of the foam may be 120 microns or less, preferably 100 or less, further preferably 90 or less, further preferably 80 or less and further preferably 60 or less. Particularly preferred pore sizes are 80 and 60. Pore size here refers to pores per linear inch or PPI, and can be measured in a number of ways, e.g. by optical microscope. The transfer means may comprise at least one outer layer of compressed foam and at least one inner flow control member. The latter may be a membrane selected for its fine/precise flow control capability. Fine/precise flow control materials are often physically delicate, and so with this arrangement, a precise but delicate flow control member can be used for precise dosing of fabric treatment composition, the inner flow control member/s protected by the compressed foam (due to its rigidity). The transfer means may form part of the reservoir which may be removable from (for replacement or refilling) or integral with a body portion of the device. The inner flow control member(s) may, for example, comprise a membrane, or a layer of e.g. semi permeable material/s e.g. polyester, polypropylene, and include Goretex and Accurel or the like or a woven/non-woven membrane which may be, but is not intended to be restricted to a thin skin. The device may comprise a support member to which the reservoir is attachable, the support member including one or more suction cups for attachment of the support member to the tumble dryer interior, and preferably the door, wherein the suction cup/s have one or more respective suction cup actuators. With this arrangement, the reservoir does not restrict access to the suction cup. Force can therefore be applied directly to the suction cup actuator which allows for more effective suction and consequently more effective attachment of the support member to the tumble dryer interior. A further advantage is that attachment of the support member need not necessitate excessive pressure being exerted on the reservoir which could then leak. The suction cup and actuator may be moveable relative to e.g. resiliently mounted on the support member. An advantage of this is that force can be applied to the suction cup actuator without restriction on such movement by the structure/rigidity of support member. There may be one or more suction cups mounted substantially centrally on the support member. This gives the advantage of a central point of attachment to the dryer interior, providing optimum stability of the device. The suction cup may have a smoothly curved outer perimeter, e.g. circular or oval. The suction cup may occupy approximately from 30% to 90%, and preferably 40% to 60% of the total area of the support member. In one embodiment, the suction cup occupies 50% of the total area. The device may be sized to allow manual installation using one hand. Accordingly the device may have an average diameter equivalent to an average hand span, e.g. 14 cm or less, and preferably 12 cm or less. In one embodiment the device has an average diameter of approximately 11 cm. The reservoir for storing fabric treatment composition may be attachable to said support member so as to lock into position. Accordingly the reservoir and support member may have corresponding inter-engagement members. The inter-engagement members may comprise one or more pairs of projections or one or more pair projections and apertures on corresponding respective portions of the reservoir and support member which are configured for snap-fit engagement. By the term aperture, it is intended to mean any formation suitable for receipt of a projection, and accordingly this term includes but is not limited to: slots, recesses, through-holes. The inter-engagement members may include resilient portions to facilitate engagement. For example, the one or more projections may include respective resilient hinge portions to allow flexing of each projection during engagement with a corresponding aperture. Alternatively or additionally, the aperture may include resilient portions to facilitate engagement. The one or more projections and/or apertures may include locking features to facilitate or improve snap-fit engagement. For example one or more projections may include one or more lugs which lock the projection/s into the respective aperture/s. The one or more lugs may be inclined to facilitate smooth engagement. The one or more projections may be biased toward a locking position with a respective aperture/projection, whereby relative resilience of the projection and or aperture and or device itself allows movement of the projection for engagement/disengagement. Further attachment members may be provided on the support member, to enhance attachment where reduced suction may result e.g. from a pitted surface (as can be found on condenser dryers). The reservoir may be housed in a body portion and removable therefrom. The transfer means may be on the body, located for fluid connection (by a channel or duct) with the reservoir (when installed). Preferably the reservoir is engageable with the body, e.g. the channel or duct as mentioned above, by a snap-fit connection or interference fit connection, so as to prevent leakage when installed. To this end the body may comprise resilient portions/components (such as the channel or duct) for elastic engagement with the reservoir for a leak-proof fit. The fluid connection preferably includes an inlet port or channel for receiving a predetermined amount of the composition from the reservoir sufficient for a predetermined number of cycles at a given temperature, time and load size and may further include a charging port or channel or recess situated directly behind the membrane for continuous feed or charging of the flow control members. The transfer of fabric treatment composition to the fabrics in the tumble drier may be effected solely by airflow generated in the tumble drier. Depending upon the model of the tumble drier and program setting temperatures of up to 100° C. with wet clothes may be generated within the tumble drier, generally in the range 30° C. to 80° C. for most drying cycles (the hot air generated by the heater in the tumble drier may be as high as 150° C., generally 110° C. to 120° C.). In addition, the transfer may be constructed and arranged such that there may be direct contact between fabric in the tumble drier and the exposed fabric treatment composition in order to facilitate transfer of fabric treatment composition to the fabric. Preferably the exterior surface of the compressed foam and the reservoir is smooth. In one embodiment the external profile of the installed device is generally hemispherical. The reservoir may hold sufficient fabric composition for any number of drying cycles and for instance the reservoir may hold sufficient composition for a single cycle. With this arrangement, different compositions could be used for different drying cycles allowing great flexibility for the user. The reservoir of the device of the invention may alternatively or additionally be capable of holding sufficient fabric treatment composition for a plurality of drying cycles of the tumble drier. In this case, the reservoir preferably holds sufficient composition for at least six, preferably at least ten drying cycles, more preferably at least twenty cycles, of the tumble drier. The device may comprise means for dispensing a unit dose of fabric composition from the reservoir at or before the start of the drying cycle which is sufficient to provide the required amount of fabric treatment composition during the drying cycle. The reservoir may be divided into a plurality of cavities or compartments each containing fabric composition, the contents of each cavity may be sequentially transferred to the transfer means. The reservoir may include means for indicating to the user when the fabric treatment composition is used up, preferably comprising visible indicia. This may be effected by a transparent or translucent reservoir (or portion/s of). There may be at least one opening of the reservoir to view the composition therein. The fabric treatment composition may be impregnated in a solid substrate which gives an appearance change, for example changes colour, when all the fabric treatment composition has been used up. The device according to the invention may comprise a reservoir which is designed to be replaced when the fabric treatment composition is used up. For example, the reservoir may be provided in the form of a disposable plastic container e.g. bottle, carton or collapsible pouch which may have a peelable lid. Alternatively, the reservoir may be designed to be recharged with a new fabric treatment composition when required. In this case the reservoir has an openable portion for charging and, if necessary, discharging the fabric treatment composition. For example, the reservoir may be provided in the form of an openable compartment into which may be placed a block or semi-permeable sachet of fabric treatment composition. Suitable materials for the reservoir include polypropylene. The fabric treatment composition may be in the form of a liquid, solid or gel. Where a solid or gel is used, this may be liquid at operating temperatures of the dryer. The composition preferably comprises at least a perfume component and optionally water and may also comprise one or more perfume solubilisers. In this way the composition can act as a freshening composition. In addition, according to a further aspect of the invention there is provided a kit for the treatment of fabrics in a tumble drying cycle, comprising the combination of the device of the first or second aspect of the invention, together with a fabric treatment composition which may contained in a reservoir suitable for use with said device. Instructions for use of the device, including installation/refilling of said reservoir may be included. In addition, according to the invention there is provided a method of treating fabrics in a tumble dryer during multiple tumble drying cycles comprising attaching a device according to the invention to the inside of a tumble dryer door and carrying out a tumble drying process with fabrics inside the tumble dryer. Further provided in accordance with the invention is a tumble dryer with a device according to the invention attached therein. BRIEF DESCRIPTION OF THE DRAWING Various non-limiting embodiments of the invention will now be more particularly described with reference to the following figures in which: FIG. 1 is a schematic perspective view of a first embodiment according to one aspect of the invention; FIG. 2 is a further view of the support member (back plate) of the device of FIG. 1 . FIG. 3 is a schematic perspective view of the reservoir of FIG. 1 . FIGS. 4 a - 4 g are different views of the reservoir bottle of FIG. 1 . FIG. 5 shows the back plate being installed. FIGS. 6 and 7 show the back plate from the rear. DETAILED DESCRIPTION OF THE INVENTION Similar reference numbers are used throughout the figures to identify common features. Referring to the drawings, there is illustrated a device 1 (shown orientated upright and viewed in perspective) for treating fabrics in a tumble dryer (not shown) during multiple tumble drying cycles, the device comprising a support member 2 and a reservoir 6 for storing fabric treatment composition attachable to said support member 2 , the support member 2 including a suction cup 8 for attachment of the support member 2 to the tumble dryer interior, and preferably the door, wherein the suction cup 2 has a respective suction cup actuator 10 . The support member 2 is a generally circular element with a peripheral skirt 14 . The suction cup 8 and rigid actuator 10 are fixed together and resiliently mounted centrally on the support member by means of a flexible bridge 12 . The bridge 12 is supported by two inclined legs 16 , 18 . The flexibility of the bridge 12 allows force to be applied to the suction cup actuator 10 without restriction on such movement by the skirt 14 . Whilst the legs are sufficiently stiff and the skirt 14 dimensioned to abut the surface of the interior of the dryer, so as to restrict movement of the support member 2 once attached. The suction cup 8 has a radius of 3.6 cm and (when viewed in plan view) occupies 50% of the total area of the support member 2 which has a radius of 5.4 cm (however the radius of the member 2 progressively increases to 5.8 cm at three points which will be described in more detail below). The device 1 is sized to allow manual installation using one hand. The reservoir 6 comprises a rigid dome shaped body 20 housing a reservoir bottle 22 configured for snap-fit engagement in a recess (not shown) of body 20 . The reservoir recess constitutes a major part of the upper half of the body 20 (when orientated upright). The reservoir 6 is attachable to the support member 2 so as to lock into position. Accordingly the reservoir 6 and support member have corresponding inter-engagement members 30 , 31 , 32 , 33 , 34 , 35 . The inter-engagement members comprise three pairs of projections 31 , 33 , 35 and apertures 30 , 32 , 34 on corresponding respective outer portions 31 a , 33 a , 35 a of the reservoir body 20 and outer portions 30 a , 32 a , 36 a of the skirt 14 of the support member 2 which are configured for snap-fit engagement. The inter-engagement members 30 , 31 , 32 , 33 , 34 , 35 are resiliently mounted or include resilient portions to facilitate engagement. The projections 31 , 33 , 35 flex by means of limited radial resilience of skirt 14 upon which they are mounted. The lowermost (when upright as shown in FIGS. 1 , 2 , 3 ) of the apertures 32 has an inclined wall 40 to assist engagement of the corresponding projection 31 . The remaining apertures 32 , 34 are simply rectangular through-holes. Thus, the device can be fitted firstly by inserting projection 33 into aperture 32 to locate reservoir 6 relative to support member 2 , and then simply pressing the remaining projections simply squeezes at the top two lugs and pulls forward. The projections include locking lugs 41 , 42 , 43 lock the projections 31 , 33 , 35 , into the respective apertures 30 , 32 , 34 . The lugs 41 , 42 , 43 are inclined radially inwards to facilitate smooth engagement. Locking is improved by the projections 31 , 33 , 35 being biased radially outwards, toward a locking position with a respective projection 30 , 32 , 34 , whereby relative resilience of the mounting of the projections 31 , 33 , 35 allows movement of the projections 31 , 33 , 35 for engagement/disengagement. As shown more clearly in FIG. 3 , the reservoir body 20 includes a chamber or inlet port 208 , having a capacity to hold a predetermined volume of fluid freshener, which is, in this embodiment 1.5 ml and is sufficient for one drying cycle of 1 hour at 60 degrees C. However, the inlet port may have a volume sufficient for any number of cycles. The port 208 is located beneath (when the device is held oriented as it would be when attached to the dryer door) and in fluid communication with the reservoir recess 204 to allow liquid to enter the port 208 from the reservoir bottle 22 when it is in place in the recess 204 . The rear of the device (shown in FIGS. 6 and 7 ) is recessed and also contains a hook 300 for supplemental attachment to the tumble dryer door of e.g. condenser dryers (which have slots or holes in the door or pitted surface). One possible hook shape is shown comprising an elongate arm which is pivotable about a pivot 302 through about 90 degrees, between a storage position in which the hook 300 is enclosed within the rear recess and an attachment position in which it projects from the device. The hook is curved only where it connects with the device—it is straight at the opposite end, as the gentle curve blocks the removal of the machine filter in some machines, so needs to be removed from the design for such machines. As shown in FIGS. 4 a - 4 g , the reservoir bottle 22 comprises a polypropylene bottle with body portion and neck portion 214 . The body portion is defined by three main generally crescent shaped faces: a front face 222 and a rear face 224 and a shoulder face 226 . The front and rear faces 222 , 224 , extend from opposed edges of the shoulder face 226 and depend therefrom to meet at a common curved edge 228 . The radius of curvature of the rear face 224 is less than that of the front face 222 . The reservoir recess 204 , has a curved back wall 230 , base wall 232 and top wall or lip 234 which correspond in shape with the rear face 222 shoulder face 226 and edge 228 respectively so that the reservoir is retained in the recess by the walls 230 , 232 and 234 and by the retaining overhanging edges of 202 and by the engagement of the neck portion 214 with the port 208 . The neck is configured for engagement with the inlet port 208 , taking into account of any seals: The inlet port 208 may include an annular resilient seal 216 of a thermoplastic elastomer (TPE) to ensure leak proof engagement of the reservoir bottle 22 with the port 208 . The reservoir bottle 22 preferably has a pin-hole (not shown) in the edge region 228 or front face 222 or back surface 224 so that as fluid freshener leaves the bottle it can be replaced with air, gradually, so as not to interfere with the gradual flow of the fluid to the membrane. This has the advantage of ensuring consistency in delivery of composition. Insertion and removal is aided by limited flexibility of the refill bottle 22 and reservoir body 20 such that snap-fit installation and removal can be effected easily. The support member 2 is first attached to the tumble dryer interior, by applying direct force to the suction cup actuator 10 . The reservoir 6 can then be attached (with reservoir bottle in place or without) as and when fabric treatment composition needs to be dispensed. When no fabric treatment is required, the reservoir 6 can be removed and the support member 2 left in place. The device 1 may alternatively comprise a one piece generally rigid dome shaped body with a reservoir recess configured for snap-fit receipt of a removable reservoir. The reservoir recess constitutes a major part of the upper half of the body (when orientated upright). The transfer means comprises two flow control members (not shown in detail but indicated at 300 ): an inner delicate but precise flow control member and an outer compressed foam layer. The inner flow control member is a polypropylene membrane with a thickness of 160 microns and a pore size of 0.2 microns. However other thickness/pore size values may be used, the appropriate pore size and thickness of the membrane varying depending on the fabric treatment composition viscosity, and the delivery rate required. The compressed foam has a compression ratio (or ‘firmness’) of 8, having been compressed from an initial thickness of 42 mm to a compressed thickness of 6 mm. The foam has an (initial, i.e. pre-compression) pore size (PPI, pores per liner inch) of 80 ppi. The foam is compressed by heat and pressure to produce a permanent compression—no compression devices are needed. The foam is a polyester foam the density of the foam material is 0.383 g/cm=kg/m (=23.9 pounds per cubic foot). The foam and membrane are fixed around their perimeters preferably by ultrasonic welds and preferably, to enable a better seal (for the purpose of preventing leaking of the fabric treatment composition), by a substantially continuous weld, to a window frame 212 . Optionally, the inlet port 208 , is integral with the window frame, again, to enable a leak proof system. The manufacture of the framed membrane involves melting upstanding ribs on the frame by ultrasonic welding so as to weld these to the perimeter of the membrane. The framed membrane is attached to the device body (by the ultrasonic welding which is done with the port/frame/membrane in situ in the device body). The area inside of the welded perimeter provides the effective flow control area that is to say the active part of the flow control members. In the embodiments shown in FIGS. 1 and 2 , the area is 40×27 mm=1080 mm. Another embodiments (not shown) may have has larger area of 50×27 mm=1350 mm, or larger still, such as 80×30=2400 mm. Preferably the effective part of the transfer means has an area in the range 500-5000 mm. Behind the members is a recess of corresponding shape which has a slightly projecting perimeter region for attachment of the frame thereto, so that a gap is defined between the inner member and the recess wall. In this narrow gap approximately 2-3 mm, a small amount of freshener fluid can collect to ‘charge’ or ‘feed’ the members continuously without causing leakages. It is important to prevent leakage of the fabric treatment composition, as this can lead to staining of fabrics. In use the reservoir is disposed with the neck pointing downwards, engaging the inlet port so that fluid from the reservoir flows, under gravity to the port and then to the members from where it evaporates/transfers in the dryer. The fabric treatment composition may take any suitable form, for example it may be as described in any of the following embodiments (e.g. solid, liquid, gel at room temperature). Suitable Fabric Treatment Compositions May be as Follows: A. first fabric treatment composition, is defined as a heat activated fabric treatment composition comprising: (a) from 3 to 75 wt % of one or more fabric treatment active ingredients; (b) from 10 to 50 wt % of water; (c) from 5 to 40 wt % of an oil; and (d) optionally from 2 to 20 wt % of a nonionic surfactant. Samples of this composition are represented by a number. Comparative samples are represented by a letter. All values are % by weight of the active ingredient unless stated otherwise. The samples in table 1 were prepared as follows: The quat, oil and optional solvent were weighed in a beaker and heated on a hot plate until molten (about 70 C). Hot water (also about 70 C) was then slowly dosed into the molten mixture with stirring. To this mixture, perfume was added and stirring continued until a ‘clear’ liquid was produced. The liquid was bottled and left to cool either in the bottle or on a rotary blender. TABLE 1 Sample 1 2 3 A B C Quat (1)* 50 50 50 80 50 50 Sirius M85 (2) 20 0 0 0 0 0 NP-35 (3) 0 20 0 0 0 0 Estol 1545 (4) 0 0 20 0 0 0 DPG (5) 5 5 5 10 0 5 PEG 200 (6) 0 0 0 0 25 0 Glycerol 0 0 0 0 0 20 Perfume 5 5 5 5 5 5 Water 20 20 20 5 20 20 (1) Stepantex VL85G (85%), tallow (IV about 35) based TEA quaternary ammonium material with 15% DPG solvent (ex Stepan) (2) mineral oil, ex Fuchs (3) mineral oil, ex Emca (4) ester oil, ex Uniqema (5) dipropylene glycol (ex Dow Chemicals). This was present in addition to any DPG present in the raw material of the quaternary ammonium material. (6) polyethylene glycol 200, ex Clariant For materials in table marked “*”, the amount denotes the level of raw material present. Further compositions were prepared according to the method described above. TABLE 4 Sample 4 5 6 7 8 D E Quat (1)* 50 55 50 55 50 50 55 DC 245 (2) 25 20 0 0 0 0 0 NP-35 (3) 0 0 20 20 0 0 0 Estol 1545 (4) 0 0 0 0 20 0 0 DPG (5) 0 0 5 0 5 0 0 DPnB (6) 0 0 0 0 0 25 40 Perfume 5 5 5 5 5 5 5 Water 20 20 20 20 20 20 0 (1) Stepantex UL G80 (80%), hardened tallow (IV < 1) based TEA quaternary ammonium material with 20% DPG solvent (ex Stepan) (2) Volatile silicone oil, ex Dow Chemicals (3) mineral oil, ex Emca (4) ester oil, ex Uniqema (5) ester oil, ex Uniqema (5) dipropylene glycol (ex Dow Chemicals). This was present in addition to any DPG present in the raw material of the quaternary ammonium material. (6) dipropyl glycol n-butyl ether *denotes the level of raw material present. The following compositions were prepared by weighing the quat, oil, nonionic and optional solvent into a beaker and heating on a hot plate until molten (about 70 C). Hot water (also about 70 C) was then slowly dosed into the molten mixture with stirring. Perfume was added and stirring continued until a ‘clear’ liquid was produced. The liquid was left to cool either in a bottle or on a rotary blender. TABLE 7 Sample 9 10 11 12 13 Quat (1)* 20 0 40 35 40 Quat (2)* 0 20 0 0 0 Emnon SCR-PK (3) 30 30 0 0 0 Squalane 99% (4)* 0 0 20 0 0 Semtol 70/28 (5) 0 0 0 15 0 Sirius M40 (6) 0 0 0 0 20 Nonionic coco 11EO (ex 20 20 5 10 5 Slovasol) Dipropylene glycol 5 5 0 0 0 Water 20 20 30 35 30 Perfume 5 5 5 5 5 (1) Stepantex ULG60 80% (DPG 20%) a hardened tallow TEA Quaternary ammonium material (IV < 1) (ex Stepan) (2) Stepantex VL85G (85%) (15% DPG) a tallow TEA (IV < 1) quaternary ammonium material (ex Stepan) (3) A sugar ester oil based on palm kernel (ex KAO) (4) A natural oil (ex Aldrich) (5) A white mineral oil (ex Goldschmidth) (6) A white medicinal quality mineral oil (ex Silkolene) *denotes the level of raw material present. All above formulations produced microemulsions at the heating temperature of a tumble dryer. An Alternative Composition B is Defined as a Heat Activated Fabric Treatment Composition Comprising (a) from 3 to 75 wt % of one or more fabric treatment active ingredients; (b) from 5 to 50 wt % of a nonionic surfactant; and (c) from 10 to 50 wt % of water. Examples of this kind of composition are as follows: The samples in table B1 were prepared as follows: The quat, nonionic and optional solvent were weighed in a beaker and heated on a hot plate until molten (about 70 C). The molten mixture was then added with stirring to hot water (also about 70 C) to which optional components such as a polyelectrolyte or salt had already been added. To this mixture, perfume was added and stirring continued until a ‘clear’ liquid was produced. The liquid was bottled and left to cool either in the bottle or on a rotary blender. TABLE B1 Sample A 1 2 3 4 5 6 7 Quat (1)* 80 10 20 0 0 0 0 0 Quat (2)* 0 0 0 40 40 40 30 10 Quaternised triethylene 0 0 0 0 0 0 5 0 amine (3) Polyelectrolyte (4) 0 0 0 0 0 0 0 16 Nonionic surfactant (5) 0 40 40 10 0 15 10 0 Nonionic surfactant (6) 0 0 0 0 15 0 0 33 DPG (7) 10 0 0 0 0 0 15 5 Glycol hydroxy pthalyl 0 0 0 15 10 0 0 0 hydroxy pthalate (8) Water 5 45 35 30 30 40 40 31 Perfume 5 5 5 5 5 5 5 5 (1) Stepantex VL85G (85%), tallow (IV~35) based TEA quaternary ammonium material with 15% DPG solvent (ex Stepan) (2) Stepantex UL G60 80% (DPG 20%), hardened tallow (IV < 1) based TEA quaternary ammonium material with 20% DPG solvent (ex Stepan) (3) TEA (ex Aldrich) fully quaternised with di-methyl sulphate (4) Catiofast CS (30% solution), ex BASF (5) Genapol C200 (coco alcohol 20EO) ex Clariant (6) Slovasol 2411, (coco alcohol 11EO) ex Sloveca (7) dipropylene glycol (ex Dow Chemicals). This was present in addition to any DPG present in the raw material of the quaternary ammonium material. (8) Glycol HPHP, ex Eastham For materials in table marked “*”, the amount denotes the level of raw material present. The viscosity of the samples was measured at a shear rate of 106 s using a Haake Rotoviscometer RV20 cup and bob NV1 at both ambient temperature and at the heating temperature of the tumble dryer.

A device for treating fabrics in a tumble dryer comprising a reservoir for storing a fabric treatment composition and transfer device to expose fabric treatment composition from the reservoir to airflow generated inside the tumble drier and/or to directly contact fabrics in the dryer, thereby transferring a portion of the fabric treatment composition into contact with fabrics in the tumble dryer during a tumble drying cycle; characterised in that the transfer device comprises compressed foam.

RELATED APPLICATIONS The present application is a continuation application of an application filed by James L. Grosh, Ser. No. 205,991, filed on Dec. 8, 1971, for Underground Reinforced Plastic Enclosure, which application Ser. No. 205,991 has been abandoned. BACKGROUND OF THE INVENTION The present invention relates in general to underground enclosures and more particularly to an underground vault or manhole for housing underground utility units such as transformers, oil switches, or other units for electrical, communication, water, sewer, gas, telephone and cable television equipment. Heretofore, underground vaults and manholes for utilities were made of reinforced concrete or from an assembly of reinforced concrete and bituminous fiber. Such vaults and manholes generally included a tubular member which was disposed vertically in the soil; a top cap disposed at ground level and seated on the tubular member; a grating or cover plate which was seated on the top cap. The top cap had a central opening and the grating or cover plate could be removed to gain access to the tubular member. Additionally, such vaults or manholes also included baffles and base plates. The tubular member was seated on the base plate and the baffle depended from the top cap. A patent of interest is the patent to Couch et al., U.S. Pat. No. 3,390,225, issued on June 25, 1968, for Underground Electrical Vault. Such underground vaults and manholes were generally made of heavy reinforced concrete with the tubular body thereof made of a light gauge metal. The metal body was usually corrugated for rigidity. At times the body was formed of a bituminized fiber or cardboard in combination with reinforced concrete top cap. In some instances, the top cap was made of cast iron. Such structures with reinforced concrete and cast iron top caps were usually quite heavy, weighing in the vicinity of 500-700 pounds depending on the size. The installation thereof required special lifting equipment. Reinforced concrete top caps were subject to chipping and cracking from field handling and from traffic loads. Bituminized fiber bodies were lighter than reinforced concrete bodies, but also were weaker. Hence, they were relatively easily damaged during installation and by unstable soil conditions. Metal bodies were undesirable because of their susceptibility to corrosion and galvanic attack. Also, they presented a safety hazard when used in conjunction with high voltage equipment. SUMMARY OF THE INVENTION An underground enclosure comprising a fiberglass polyester resin housing on which is seated a reinforced plastic mortar top cap. A feature of the present invention is the reinforcement of the rigidity of the body by reinforced plastic mortar rings and struts. The top cap has a central opening on which top cap is seated a metal grating. Alternatively, a reinforced plastic mortar cover plate may be seated on the top cap. Another feature of the present invention is a baffle of fiberglass polyester resin that depends from the top cap into the body. By virtue of the present invention, a lightweight, high strength enclosure is achieved that is safe and is highly resistant to corrosion as well as galvanic attacks. With the increased demand for utility vaults created by the placement of power and communication utilities underground, there is a present need for lightweight, strong vaults which can be shipped and installed with facility and ease of operation. Reinforced plastic mortar caps meet the structural requirements for light vehicular traffic loading, while reinforced concrete top caps require a heavy steel frame and beams to meet the same loading conditions. Applicant of the present application has filed an application on Reinforced Plastic Mortar Underground Enclosures, Ser. No. 191,390, filed on Oct. 21, 1971. DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the underground reinforced plastic enclosure embodying the present invention. FIG. 2 is a vertical section view of the underground reinforced plastic enclosure taken along line 2--2 of FIG. 1 and illustrated installed in soil. FIG. 3 is an exploded view of the underground reinforced plastic enclosure shown in FIG. 1. FIG. 4 is a plan view of the top cap of the enclosure shown in FIG. 1. FIG. 5 is a vertical section view taken along line 5--5 of FIG. 4. FIG. 6 is a diagrammatic plan view of an assembled mold for producing the top cap shown in FIGS. 4 and 5. FIG. 7 is a diagrammatic vertical sectional view taken along line 7--7 of FIG. 6. DESCRIPTION OF THE PREFERRED EMBODIMENTS Illustrated in FIGS. 1-5 is the reinforced plastic enclosure 10 embodying the present invention which comprises a body 15, which may be rectangular in cross-section or may have a cylindrical configuration. The body 15 is suitable as an enclosure for an underground utility transformer or an underground utility oil switch. In use, the body 15 is disposed in soil. (FIG. 2). The body 15 is seated on a base 20 which is illustrated as having a disc configuration. However, the shape of the base 20 will conform to the configuration of cross-sectional area of the body 15. Seated on the body 15 is a top cap 25, which has a rectanguloid configuration and is formed with a central cylindrical opening 26. A rectangular recessed area 27 is formed from the upper wall of the top cap 25. When the enclosure 10 is in use, the top cap 25 will be disposed at ground level. (FIG. 2). A metal grate 30, or optionally a solid reinforced plastic mortar cover plate, is seated on the top plate 25 within the recess 27. Depending from the top cap 25 radially outward from the body 15 is a grade adjustment skirt 35 (FIGS. 1-3) and depending from the top cap 25 radially inward from the body 15 is a baffle and tamper shield 40. (FIGS. 2 and 3). Radially disposed grooves 41 (FIGS. 3 and 4) are formed in the upper wall of the top cap 25 to receive support arms 42 (FIG. 3) of the baffle and tamper shield 40. When a utility maintenance or installation employee desires to gain access into the body 15, the grating 30 is temporarily removed from the top cap 25. The base 20 is supported by the soil below the level of the ground and is formed from a reinforced plastic mortar. Projecting upwardly from the top wall of the base plate 20 is a ridge 50 (FIGS. 2 and 3). Seated on the base 20 is the body 15 with the interior surface of the body 15 abutting against or contiguous with the outer wall of the ridge 50. Since the exemplary embodiment of the body 15 shows a cylindrical wall, the ridge 50 has an annular configuration. An opening 51 is formed axially of and through the disc base 20 for drainage of water, moisture or the like that may collect in the body 15. Should it be desired to fix the body 15 to the base 20, suitable bolts and brackets may be provided, such as the ones employed to secure the top cap 25 to the body 15. From FIGS. 1-3, it is seen that the body 15 is disposed on the base 20 with the axis thereof in the upright position. The body 15 is made from a fiberglass polyester resin. Optionally, the body 15 may be preformed as a cylinder, or may be separated along confronting longitudinal edges, or may be separated along diametrically opposite confronting longitudinal edges. The separation of the body 15 along longitudinal edges is for convenience of handling and shipping. When assembled, suitable nuts and bolts secure projecting flanges of confronting edges to form a cylindrical body. For reinforcing the body 15, annular ribs 55 (FIGS. 1 and 2) and longitudinal ribs 56 are formed along the exterior wall thereof. The annular ribs and the longitudinal ribs are formed from reinforced plastic mortar. The annular and longitudinal stiffeners 55 and 56 provide rigidity to the body 15 for resisting earth loads. Formed in the body 15 are suitable knockouts shown by scoring 57 (FIG. 1), which are respectively removed when it is desired to have conduits received by the body 15. When the body 15 encloses a transformer, it is generally of greater dimension longitudinally then when it encloses an oil switch. The top cap 25 is made from a reinforced plastic mortar 70. (FIGS. 2, 5 and 7). All reinforced plastic mortar 70 employed herein is formed in a similar manner and contains similar ingredients. Hence, only the formation of the reinforced plastic mortar 70 for the top cap 25 will be described in detail. The reinforced plastic mortar 70 comprises an outer layer 71 and an inner layer 73. Both layers 71 and 73 are of high strength glass filament, mat, woven cloth or woven roving. The thickness and type of material of the layers 71 and 73 are determined by the strength requirement for the mortar 70. In addition, the reinforced plastic mortar 70 includes a core 72 which is sandwiched between the layers 71 and 73. The core 72 is composed of a synthetic thermosetting resin or a synthetic plastic resin of the thermosetting type, such as polyester, epoxy, furane, polyurethane and the like. The thermosetting resin is filled with inert or inorganic fillers or graded aggregate material. The filler may be in the form of sand or gravel or a combination thereof. In the process of producing the top cap 25, a suitable mold assembly 80 (FIGS. 6 and 7) is employed which may be made from metal or fiberglass. Initially, the outer layer 71 of glass filament is applied to the recessed surface of the mold assembly 80 (FIG. 7). The outer layer 71 of glass filament is applied to the recessed wall of the mold assembly 80 by brushing or spraying a thin film polyester thermosetting resin with thixotropic fillers and ultra violet suppresents on the recessed wall of the mold assembly and then placing the glass filament thereupon. In areas where abrasive surfaces are present, sand or quartze particles may be added. Additional layers of reinforcing glass filament are added to form stratified layers. The additional layers may be added by spray-up or by manually adding a woven mat of glass filament. Thereupon, a mixture of thermosetting resin and filler forming the core 72 is placed into the recessed area of the mold assembly. Alternatively, a slurry of thermosetting resin and filler forming the core 72 may be placed into the recessed area of the mold assembly 80. The type of filler employed would depend on the strength requirements of the core material. In an exemplary embodiment for a dry mix, the thermosetting resin for the mixture constitutes about 3% by weight and the aggregate filler may be of a size in the range of 1/8 inch to 1/4 inch. This mixture would be porous in composition and yield a compressive strength in the vicinity of 500 p.s.i. The slurry mix, in the exemplary embodiment, may be 20% of thermosetting resin content by weight and the filler of a mixture of aggregate and sand. A core produced thereby would be non-porous in composition and yield a compressive strength of 30,000 p.s.i. Now, the inner layer 73 of glass filaments, similar to the outer layer 71 of glass filament, is placed on top of the recessed area of the mold assembly 80. At this time, threaded inserts or threaded studs may be positioned in the appropriate places to become an integral part of the top cap 25. The thermosetting resin polymerizes or hardens. The polymerization can be accomplished at room temperature or it can be accelerated by heat. The heating of the mold assembly 80, although not required, will accelerate the curing of the thermosetting resin. When the mold assembly 80 is heated to 150°F., the top cap 25 can be removed from the mold assembly 80 in 15 minutes. Otherwise, the top cap 25 can be removed in approximately 1 hour depending upon the exotherm for cure. The top cap 25 is secured to the upper portion of the body 15 by means of brackets and bolts as shown in FIG. 2. The baffle and tamper shield 40 is made of a fiberglass reinforced plastic. As previously described, the cross-arms 42 project outwardly and seat in the grooves 41 of the top cap 25 for depending the baffle and tamper shield 40 from the top cap 25. Carried by the cross arms 42 is a tubular member 90 (FIGS. 2 and 3), which is secured thereto by means of brackets and bolts. The upper wall of the member 90 is bevelled and defines an annular opening 91. Also fixed to the cross arms 42 is a tamper shield 92 that is disposed within the tubular member 90 along the axis thereof. The baffle 92 has a centrally disposed disc plate 92a with an inwardly flared apron 92b depending therefrom. The baffle-tamper shield 40 serves two functions. Firstly, it prevents access to the equipment enclosed by the body 15 while the grate 30 is installed on the top cap 25 and yet provides a path for the conduction of heat generated within the body 15 to escape through the grate 30. The grade adjustment skirt 35 is made of reinforced plastic mortar and has a cylindrical configuration and is fixed to the top cap 25 by brackets and nuts to depend therefrom. The body 15 is disposed in the soil slightly below the ground level. On the other hand, the top cap 25 is disposed along the finished ground level. As a consequence thereof, a gap may exist between the top cap 25 and the upper end of the body 15. The grade adjustment plate 35 occupies the gap between the body 15 and the top cap 25 to act as a stop for preventing dirt from seeping into the body 15. Thus, the grade adjustment plate serves as a dirt stop for the gap between the body 15 and the top cap 25, and also serves to enable the top cap 25 to be adjusted for occupying a position along the grade level of the ground. The axial length of the skirt is determined by the degree of adjustment required for the top cap 25.

An underground reinforced plastic enclosure comprising a vertically and circumferentially stiffened body. The body is made of a fiberglass polyester resin and the stiffeners are of a reinforced plastic mortar. The body is suitable for surrounding a transformer or an oil switch used in underground utilities. On the body is seated a top cap made of reinforced plastic mortar. The top cap is formed with a central opening. Seated on the top cap is a reinforced plastic mortar cover plate or a metal grate. Depending from the top cap is a fiberglass polyester resin baffle and tamper shield. The body seats on a base of reinforced plastic mortar. A grade adjustment skirt also depends from the top cap outwardly from the baffle and tamper shield.

CROSS-REFERENCES TO RELATED APPLICATIONS [0001] This application claims the benefit of the European patent application No. 12382057.3 filed on Feb. 20, 2012, the entire disclosures of which are incorporated herein by way of reference. FIELD OF THE INVENTION [0002] The present invention relates to a device used for providing dynamic isolation and damping of dynamic vibrations originated in the launch vehicle of a space shuttle and reaching the satellite. BACKGROUND OF THE INVENTION [0003] A space shuttle is designed for carrying payloads or satellites into different space orbits. Each space shuttle is a launch system comprising an external tank supplying the liquid oxygen and hydrogen fuel to the main engines, two solid rocket boosters providing the thrust needed for the lift-off of the whole space shuttle, and a satellite, orbiter or payload which has to be placed in a required orbit in the outer space. The space shuttle is designed as a function of the payload that is needed to be put into orbit in space. [0004] During lift-off and ascent, the external tank in the space shuttle supplies the fuel and oxidizer under pressure to the main engines in the space shuttle. In the known prior art, these external tanks comprise two separate tanks, one comprising the liquid oxygen fuel and the other one comprising the liquid hydrogen fuel, such that each of these tanks is joined to the structure of the external tank by means of a metallic structure isolating and damping the vibrations and loads transmitted to the two tanks comprising the liquid fuel. Further developments have been made and the external tanks no longer comprise the mentioned configuration, but the whole external tank is rather divided internally into two chambers, one chamber comprising liquid hydrogen fluid and another one comprising liquid oxygen fuel, both chambers being separated by means of a membrane. This configuration results in the payload in the space shuttle receiving very high loads and vibrations which have been transmitted by the external structure. It is therefore needed to develop a device that is able to properly dampen and isolate the payload from these loads and vibrations. The device that has to be developed must be a device having, at the same time, enough stiffness, flexibility and dampening properties, and this would ideally need to be valid for every space shuttle and for every payload in it. [0005] It is known from the state of the art, as per document U.S. Pat. No. 7,249,756 B1, a mounting system passively damped and isolated from vibrations, comprising a plurality of elements, each element having a very low profile, such that the system that is able to be used in a space shuttle for an application as the one just mentioned. However, the mounting system in U.S. Pat. No. 7,249,756 B1 presents several problems and disadvantages: as the damping and isolation functionalities in each of the elements forming the system are functionally and structurally joined, the design and characterization of these elements has to be made for each single application where the system is going to be used, therefore not allowing an easy and unique design. Besides, the same element configuration cannot be used for different space shuttles and different payloads, but rather need to be redesigned for each particular case. Furthermore, this design would not allow a growth potential and flexibility of redesign as, if for example higher stiffness is required, the element needs to be made wider and the number of elements would prevent this redesign from being placed within the space shuttle structure. Even one more disadvantage of the system in U.S. Pat. No. 7,249,756 B1 would be that it could not be properly used in composite material structures, which are the structures mostly used at present for space applications. [0006] The present invention is intended to solve said disadvantages and limitations in the prior art. SUMMARY OF THE INVENTION [0007] In a first aspect, the present invention discloses a device used for providing dynamic isolation and damping of dynamic vibrations, in a passive way, originated in the launch vehicle of a space shuttle and reaching the payload or satellite. The device of the invention comprises a plurality of identical elementary unit elements, such that the device is designed in a modular way, allowing the individual modularity of each one of the elementary unit elements: therefore, each of the elementary unit elements is tailored and designed individually, such that the complete device can be designed for each particular application and payload needed as a function of each of the elementary unit elements, thus allowing an easy design and lower costs, for a wide range of payload applications. [0008] Each of the elementary unit elements comprises a spring component and a damping component, such that the functionalities provided for each component are separated and can be individually tailored, thus providing a device having a wider range of adaptation capabilities. [0009] Furthermore, the elementary unit elements are preferably manufactured of a composite material, so that the device of the invention can be used in composite structures within a space shuttle. BRIEF DESCRIPTION OF THE DRAWINGS [0010] The foregoing objects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings, wherein. [0011] FIGS. 1 a , 1 b and 1 c show a schematic general view of the configuration of a space shuttle damping and isolating device according to the present invention, showing the plurality of elementary unit elements for different payload configurations. [0012] FIG. 2 shows a schematic view of the elementary unit element configuring the space shuttle damping and isolating device according to the present invention. [0013] FIGS. 3 a and 3 b show detailed views of the elementary units forming the spring component in the elementary unit element configuring the space shuttle damping and isolating device according to the present invention. [0014] FIGS. 4 a , 4 b and 4 c show detailed views of the plurality of elementary units forming the spring component in the elementary unit element configuring the space shuttle damping and isolating device according to the present invention. [0015] FIG. 5 shows a detailed view of the damping component in the elementary unit element configuring the space shuttle damping and isolating device according to the present invention. [0016] FIG. 6 shows a detailed view of the damping component and of the spring component being joined in order to constitute the elementary unit element configuring the space shuttle damping and isolating device according to the present invention. [0017] FIGS. 7 a , 7 b , 7 c and 7 d show schematically different views of the quasi-parallel working mode of the space shuttle damping and isolating device according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0018] The invention discloses a device 10 used for providing dynamic isolation and damping of dynamic vibrations, in a passive way, originated in the launch vehicle of a space shuttle and reaching the payload or satellite. The device 10 of the invention comprises a plurality of identical elementary unit elements 20 , such that the device 10 is designed in a modular way, allowing the individual modularity of each one of the elementary unit elements 20 . FIGS. 1 a , 1 b and c show schematic views of the device 10 according to the present invention, comprising a plurality of elementary unit elements 20 , this device 10 being located at any position in the upper stage structures of the launch vehicle, in such a way that this device 10 interferes in the load path from the launch vehicle to the space shuttle. [0019] As shown in FIGS. 1 a , 1 b and 1 c , the proposed baseline where the device 10 of the invention is set has a diameter of 1780 mm, which represents a standard diameter measurement for space shuttles and satellites. It is also a standard for space shuttles and satellites to have a maximum of 144 equidistance positions within the diameter of 1780 mm, such that the fixing of the device 10 is made by a fixing element in each one of these 144 positions. In the embodiment shown in FIG. 1 a , the device 10 comprises 144 identical elementary unit elements 20 . Because the same device 10 will be used for a wide range of space shuttles and payloads, typically in the range of 1 ton to 6 tons, the modular configuration of the device 10 will differ depending on the payload to support; for example, payloads comprised between 4.5 and 6 tons will use a device 10 comprising 144 identical elementary unit elements 20 , payloads comprised between 3.5 and 4.5 tons will use a device 10 comprising 72 identical elementary unit elements 20 , and payloads below 3.5 tons will use a device 10 comprising 36 identical elementary unit elements 20 , for example. Other different configurations of the device 10 will also be possible, and these mentioned only represent typical embodiments. [0020] FIG. 2 shows a general view of each of the elementary unit elements 20 in the device 10 , providing dynamic isolation and damping functions by means of a combination of a spring component 11 and a damping component 12 . The spring component 11 is formed by two symmetric stacks 111 and 112 , each stack 111 or 112 comprising a plurality of leaf springs 113 . The damping component 12 is formed by at least one stack 125 comprising a plurality of damping leafs 120 . The stacks 111 and 112 in the spring component 11 and the at least one stack 125 forming the damping component 12 (the embodiment shown in the attached Figures shows a damping component 12 comprising three stacks 125 ) are joined together at their ends by joining elements 30 , preferably by mechanically preloaded bolt elements, as shown in FIG. 2 . Besides, inserts 400 , typically screwed, are assembled at the top and bottom parts of the two symmetric stacks 111 and 112 , in order to provide mechanical interfaces with the adjacent structures to which the device 10 is joined. [0021] One of the main advantages of the device 10 of the invention comes from the configuration of each elementary unit element 20 comprising a spring component 11 and a damping component 12 working in a quasi-parallel mode as follows: the working way of the elementary unit element 20 is based in the combination of the axial-vertical 200 relative displacement (up-down) of the two symmetric stacks 111 and 112 , providing the main stiffness properties for each elementary unit element 20 , together with the radial-horizontal 300 relative displacement (right-left) of the two symmetric stacks 111 and 112 joining the at least one stack 125 forming the damping component 12 at their ends, providing the main damping properties for each elementary unit element 20 . The geometry and configuration of the leaf spring 113 in the stacks 111 and 112 drives the ratio of both relative displacements, of the axial-vertical 200 relative displacement (up-down) and of the radial-horizontal 300 relative displacement (right-left), therefore providing a multiplication factor (<1 or >1) that can be defined according to design needs. The fact that this ratio of relative displacements can be different from 1, results in the working mode of each elementary unit element 20 being not completely parallel, but quasi-parallel. This has the advantage that the design of the damping properties and of the stiffness properties can be made individually and through the ratio just mentioned, in such a way that: when the ratio is below 1, the damping properties in the elementary unit element 20 are higher than the stiffness properties; however, when the ratio is above 1, the stiffness properties in the elementary unit element 20 are higher than the damping properties. [0022] FIGS. 7 a - 7 d show schematically the quasi-parallel working mode of the device 10 , as well as the angles and ratios. As such, FIG. 7 a shows the still mode configuration of the device 10 , such that the stack 111 forms an angle □ with the damping component 12 . Symmetrically, the stack 112 forms also an angle □ with the damping component 12 . In the still mode shown in FIG. 7 a , the initial angle □ is of 45°; the working mode of the device 10 was parallel, this angle □ would be maintained throughout the movement of the stacks 111 and 112 with respect to the damping component 12 , so that the ratio of the axial-vertical 200 relative displacement (up-down) and of the radial-horizontal 300 relative displacement (right-left) would be equal to 1 (see different positions of the device 10 shown in FIG. 7 c ). However, in the quasi-parallel mode of the invention, the ratio of the axial-vertical 200 relative displacement (up-down) and of the radial-horizontal 300 relative displacement (right-left) is different from 1, as the angle □ is not 45°, which results in the working mode of each elementary unit element 20 being not completely parallel, but quasi-parallel. As it has been previously described, the design of the damping properties and of the stiffness properties can be made individually and through the ratio just mentioned, in such a way that: when the ratio is below 1, the radial-horizontal 300 relative displacement (right-left) is higher than the axial-vertical 200 relative displacement (up-down), the angle □ is below 45° and the damping properties in the elementary unit element 20 are higher than the stiffness properties (see representations in FIG. 7 b ); when the ratio is above 1, the axial-vertical 200 relative displacement (up-down) is higher than the radial-horizontal 300 relative displacement (right-left), the angle □ is greater than 45° and the stiffness properties in the elementary unit element 20 are higher than the damping properties (see representations in FIG. 7 d ). [0023] The device 10 of the invention is sized as to its elementary unit elements 20 to support static and dynamic loads going through the structures of the space shuttle. To that, it is possible to match any stiffness/strength/damping requirement using the adequate configuration of the spring component 11 and of the damping component 12 : this means that the concept underlining the invention offers an additional modularity to the design, making it possible to match different isolation requirements (stiffness and damping) at the level of the elementary unit element 20 itself. [0024] The selected materials used for the spring component 11 and for the damping component 12 can be further reviewed if needed, or even combined, accordingly the stiffness, the loads to be supported and the damping requirements and, hence, the design at the level of the elementary unit elements 20 is susceptible of potential optimizations and/or of updates to evolutions of requirements. One possible embodiment (as the one shown in FIG. 2 ) comprises five leaf springs 113 on each stack 111 and 112 , Preferably, the same material forming these leaf springs 113 also configures some of the damping leafs 120 forming the damping component 12 in the embodiment shown in FIG. 2 , this material preferably comprising carbon fiber reinforced polymer, CFRP (further explanation of the materials for the damping component 12 will follow). [0025] Each symmetrical stack 111 and 112 configuring the spring component 11 of the elementary unit element 20 comprises a stack of a plurality of leaf springs 113 of certain dimensions: preferably, in the embodiment of FIG. 2 , each stack 111 or 112 comprises five leaf springs 113 each, made of CFRP, with the following dimensions: 2 mm thickness, 30 mm width and 200 mm length. The package of the stacks 111 and 112 is guaranteed by means of the edge holes 41 and pads 40 , as shown in FIGS. 3 a and 3 b . Besides, each leaf spring 113 is also drilled at the center, providing an interface hole 42 . Thus, the edge holes 41 provide the assembly of the leaf springs 113 in each stack 111 and 112 , while the interface holes 42 serve as an interface with other elements. [0026] Each leaf spring 113 also comprises preferably three flat pads 40 , preferably rectangular, located at the edges, where the edge holes 41 are, and also at the center, where the interface hole 42 is (see FIGS. 3 a and 3 b ). The flat pads 40 have the following purposes: [0027] provide a flat contact surface; [0028] separate the leaf springs 113 ; [0029] provide strength compensation to the interface holes 42 and to the edge holes 41 ; [0030] allow the assembly of the stacks 111 and 112 by further tightening by means of bolts at the edge holes 41 ; [0031] allow interface inserts tightening by means of inserts at the interface holes 42 . [0032] FIGS. 4 a , 4 b and 4 c show the configuration of the stacks, 111 or 112 , by means of a plurality of leaf springs 113 , preferably five leaf springs 113 , that come together at the edges through the flat pads 40 at the edge holes 41 , such that the stack formed, 111 or 112 , is also properly joined at the interface holes 42 through flat pads 40 . [0033] The damping component 12 , as shown in FIG. 5 , comprises a plurality of stacks 125 , preferably three, as shown in the embodiment of the cited FIG. 5 . The embodiment of FIG. 5 shows a total of five damping leafs 120 for each of the three stacks 125 , making a total of five layers for each stack 125 , configured in the sandwich-type, in the following preferred way: [0034] a primary CFRP layer 121 ; [0035] a damping layer 122 , preferably made of silicone rubber; [0036] a third CFRP layer, comprising two symmetric leafs 123 and 123 ′; [0037] a fourth damping layer 124 , preferably made of silicone rubber; [0038] a fifth layer of CFRP 125 . [0039] The third layer or center layer is formed by two symmetric leaves 123 and 123 ′, allowing relative displacement and shear deformation of the leaves 123 and 123 ′, preferably made of silicone rubber, at each side, therefore providing a simple energy dissipation mechanism. Furthermore, assembly holes 130 at both ends are provided, together with assembly flat pads 140 , facilitating the integration with the spring component 11 of the elementary unit element 20 , at the edge holes 41 . [0040] Final integration of the above-described parts forming each of the elementary unit elements 20 configuring the complete device 10 used for providing dynamic isolation and damping of dynamic vibrations of the invention is shown in FIG. 6 , and will be explained as follows: [0041] the plurality of symmetric leaf springs 113 come together at the edges, through the edge holes 41 and flat pads 40 , together with the interface holes 42 and flat pads 40 , thus being formed the two symmetric stacks 111 and 112 ; [0042] the plurality of damping leafs 120 come together at the edges, through the assembly holes 130 and pads 140 , thus being formed each of the stacks 125 of the damping component 12 . [0043] The assembly of the stacks 111 and 112 configuring the spring component 11 , together with the stacks 125 configuring the damping component 12 , is preferably made at edge holes 41 mating the holes 130 in the damping component 12 , by means of joining elements 30 , preferably numbering four, these joining elements preferably comprising stainless steel screwed bolts, which further preload the full packages of stacks of 111 , 112 and 125 by tightening nuts on top, this tightening being properly done by means of the flat pads of stacks 111 and 112 at the edges 40 , mating the pads 140 at the edges of the stacks 125 . [0044] The mechanical interface of the device 10 with the adjacent structures at the space shuttle is provided by means of inserts 400 , preferably two, and more preferably being these inserts 400 made of aluminum alloy, such that these inserts are located at the central interface holes 42 of each stack 111 and 112 configuring the spring component 11 , also with the help of the central flat pads 40 . These inserts 400 are self tightened one against the other up to preload the top and bottom flat surfaces of the stacks 111 and 112 . These inserts are preferably screwed in order to provide a quick and easy interface with the rest of the structures in the space shuttle. FIG. 6 shows the way the total assembly of device 10 is formed. [0045] Furthermore, the elementary unit elements 20 are preferably manufactured in composite material, so that the device 10 of the invention can be used in composite structures within a space shuttle. [0046] Although the present invention has been fully described in connection with preferred embodiments, it is evident that modifications may be introduced within the scope thereof, not considering this as limited by these embodiments, but by the contents of the following claims. [0047] As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.

A device used for providing dynamic isolation and damping of dynamic vibrations, in a passive way, originated in the launch vehicle of a space shuttle and reaching the payload or satellite. The device comprises a plurality of identical elementary unit elements, such that the device is designed in a modular way, allowing the individual modularity of each of the elementary unit elements. Each of the elementary unit elements is tailored and designed individually, and the complete device can be designed for each particular application and payload needed as a function of each of the elementary unit elements allowing an easy design and lower costs, for a wide range of payload applications. Each elementary unit element comprises a spring component and a damping component, such that the functionalities provided for each component are separated and can be individually tailored, thus providing a device having a wider range of adaptation capabilities.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of removing from a surface region of a silicon semiconductor substrate heavy metal impurities which are introduced into the substrate during wafer processing. More particularly, the present invention relates to a method of gettering heavy metal impurities, such as iron and chromium, which has been difficult to remove by a conventional intrinsic gettering method. As is known, if a CCD (charge coupled device) is used as an image sensor, heavy metal impurities introduced into the silicon substrate increase the level of an output signal of dark current, thus leading to a deterioration in sensor characteristics. The present invention is particularly effective when applied to gettering subsequent to wafer processing during CCD fabrication. 2. Description of the Related Art In general, impurities such as a small amount of oxygen or carbon are introduced into silicon during the initial step of growing an ingot. It is, therefore, extremely difficult to avoid problems due to impurities, such as the contamination of wafers or the occurrence of crystal defects, in a device fabrication process using silicon wafers. Gettering techniques are known for achieving good device characteristics by removing such impurities or incidental crystal defects from an element forming region. One gettering technique is called an IG (intrinsic gettering) technique in which impurity gettering is implemented by forming crystal defects in the interior of a silicon wafer and absorbing the impurities therein. A typical example of the process of a known IG technique is explained below. In the process, prior to or in part during wafer processing, a silicon wafer is exposed to the following three steps of heat treatment in a nitrogen gas atmosphere. Step (1) involves heat treatment of 30-60 minutes at 1100° C. In Step (1), oxygen impurities are removed from a wafer surface by outward diffusion to form a defect-free zone on the surface. Step (2) involves heat treatment of several hours at 700° C. In Step (2), nuclei of oxygen precipitation are produced in the interior of the wafer. In Step (3) involves heat treatment of 1 hour at 1000° C. In Step (3), oxygen is attracted to the nuclei of oxygen precipitation and increase the number of associated small defects, thereby increasing the ability of gettering. The high-density defect-layer region in the wafer in which oxygen is precipitated throughout the above-described steps, is called an IG layer and a surface defect-free zone is called a DZ (denuded zone). Manufacturing processes for silicon semiconductor devices, particularly wafer processes, encounter the problem of contamination due to metallic impurities. The contamination due to metallic impurities may cause increases in leakage currents at pn junctions or an incidental deterioration in voltage-resistance characteristics, or otherwise the lifetime decrease of carriers. Impurities which have particularly serious influences are heavy metal impurities such as iron (Fe), chromium (Cr), copper (Cu) and nickel (Ni). In the case of an image sensor employing a semiconductor device such as a CCD, junction leakage currents due to impurities in a photodetector region increase dark current and decrease device performance. In DRAMs, increases in junction leakage currents will require a short refresh time and cause imperfect refreshing. The above-described known IG technique which serves the function of removing such heavy metal impurities from an active element region, effectively works on Cu, Ni or the like, but is not sufficiently effective on Fe and Cr. To improve the performance of semiconductor devices, it is desired to establish a reliable gettering technique for the above-mentioned heavy metal impurities. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method of gettering heavy metal impurities, which cannot be removed by a conventional intrinsic gettering technique, from a region adjacent to the surface of a silicon wafer. It is another object of the present invention to provide a manufacturing method in which prevention of leakage current in a semiconductor device employing a p-type silicon substrate is contemplated, particularly a manufacturing method which makes it possible to decrease dark current in a CCD type image sensor. To achieve the above and other objects, a method of gettering heavy metal impurities from a p-type silicon substrate according to the present invention, comprises the steps of subjecting the silicon substrate to heat treatments to form an intrinsic gettering layer having a large density of crystal microdefects in the interior of the substrate, then carrying out the wafer processes required to manufacture semiconductor devices other than the formation of a metallic wiring layer, and subsequently heating the silicon substrate to approximately 200° C. and simultaneously irradiating the substrate with light rays, thereby absorbing the heavy metal impurities into the inner intrinsic gettering layer. The above and other objects, features and advantages of the present invention will be apparent from the following description of a preferred embodiment of the invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graphic representation showing the result obtained by measuring Fe concentration by a DLTS method after a p-type silicon wafer has been exposed to heavy metal contamination; FIG. 2 is a graphic representation showing the results obtained by measuring variations in the surface Fe concentration of different p-type silicon wafer samples under various conditions including the presence or absence of Fe contamination, the presence or absence of an intrinsic gettering (IG) layer and differences in gettering processes; FIG. 3 is a diagrammatic view showing the crystalline structure obtained by introducing Fe impurities into a p-type silicone crystal, and shows that Fe may form either a Fe-B pair or interstitial Fei as the case may be; FIG. 4 is a diagrammatic view which serves to illustrate the principle of a gettering method according to the present invention; FIGS. 5(a)-5(d) are graphic representations showing the variations in DLTS measurement data which are obtained by changing gettering methods after a p-type silicon substrate has been exposed to Fe contamination; FIG. 6 is a graphic representation showing the relationship between the diffusion coefficient of Fei and the temperature; and FIG. 7 shows in flow-chart form a semiconductor-device manufacturing process to which the present invention is applied. DESCRIPTION OF THE PREFERRED EMBODIMENTS To examine the cause of an increase in dark current in the photo-detection region of a CCD, a p-type silicon wafer passed through the same process was subjected to a DLTS (deep level transient spectroscopy) measurement to examine the state of heavy metal contamination. It was found that iron (Fe) and boron (B) as an acceptor are present in the state of a Fe-B pair in silicon (Si). FIG. 1 is a graphic representation showing the results of measurement utilizing a DLTS method. In a general DLTS measurement method, reverse pulse voltage is applied to a pn junction and the resulting capacitance is measured at times t 1 and t 2 after the application of the reverse pulse voltage. The measured capacitance difference ΔC is plotted with respect to temperature. For actual measurement, the temperature was changed from 40 K. to 320 K., and sampling times t 1 =200 μs and t 2 =2 ms were selected. The vertical axis corresponds to a unit proportional to the aforesaid ΔC. The illustrated abrupt decrease in signal level is caused by contamination due to impurities and its peak value is proportional to the concentration of the impurities. Since the peak is in the neighborhood of 60 k, the peak is found to correspond to the above-mentioned Fe-B pair by examining correlation with the measurement data obtained by an infrared absorption analysis, an ESR (electron spin resonance) analysis or the like. The characteristics of heavy metal impurities which are contained in silicon are disclosed in the following documents, and detailed explanation is omitted. (1) "Transition Metals in Silicon" by Eicke R. Weber; Appl. Phys., A30, 1-22 (1983); and (2) "The Properties of Iron in Silicon" by K. Graff and H. Pieper; J. Electorochem. Soc., Vol. 128, No. 3 (1981). In addition, an experiment was conducted to examine what degree of contamination due to heavy metal could be removed from the surface active region of a silicon wafer by the conventional IG technique described above. The following three groups of samples were prepared. Group No. 1: Although heat treatments for forming an IG layer on a wafer are performed, the wafer is not exposed to intentional Fe contamination. Group No. 2: Heat treatments for forming an IG layer on a wafer are not performed and the wafer is exposed to Fe contamination. Group No. 3: After heat treatments for forming an IG layer on a wafer have been performed, the wafer is exposed to Fe contamination. In the aforesaid experiment, a B-doped p-type silicon wafer having a resistivity of 10 Ωcm and an oxygen-impurity concentration of 1.70-1.87×10 cm -3 was used as a silicon wafer sample. The heat treatments for IG-layer formation were conducted in three steps: at 1000° C. for 30 minutes, at 650° C. for six hours, and at 1000° C. for 30 minutes. Each wafer was dipped in a 60% HNO3 solution containing 500 ppm of Fe ions. The surface concentration of the Fe impurities was 5.0×10 13 cm -2 . The wafer sample of each group was finally subjected to a heat treatment of 1000° C. for 1 hour to diffuse Fe in the interior of the wafer sample, thereby effecting gettering. FIG. 2 shows the results. As can be seen from FIG. 2, the Fe concentration of Group No. 2 exposed to Fe contamination and devoid of an IG layer is about three digits greater than that of Group No. 1 which was not exposed to Fe contamination. In contrast, the Fe concentration of Group No. 3 exposed to Fe contamination and provided with an IG layer is as low as approximately one fifth of the Fe concentration of Group No. 2. However, Group No. 3 is approximately two digits greater in Fe concentration than Group No. 1, which means that ordinary IG methods do no provide satisfactory gettering. The width of a denuded zone (DZ) of the wafer surface of Group No. 3 is approximately 12 μm, and the concentration of crystal defects in the IG layer is 5.0×10 5 cm -2 . It is to be understood, therefore, that effective IG treatment was achieved with respect to Group No. 3. These findings demonstrate that Fe which is heavy metal is extremely difficult to getter by ordinary IG techniques. As described in detail in the above-mentioned documents (1) and (2), it is known that the properties of Fe in a p-type (B-doped) Si crystal are divided into two kinds in accordance with the value of activation energy. One kind of Fe forms interstitial Fe (Fei) and the activation energy is represented as Ev +0.40eV. The other kind of Fe forms substitutional Fe which is paired with a dopant B to form Fe-B, and the activation energy is represented as Ev +0.10eV. FIG. 3 is a diagrammatic view showing the state where the aforesaid two kinds of Fe are presented in the crystal structure of silicon. In the drawing, the substitutional Fe is shown surrounded by dotted lines and an interstitial Fei is shown at a location away from the substitutional Fe. In general, Fe of both Fei and Fe-B coexists and the total amount of Fe does not vary, but the Fe ratio of Fei to Fe-B varies due to various factors such as the hysteresis of heat treatments and the elapsed time thereafter. More specifically, when the wafer is quenched after heat treatments, a major part of Fe forms interstitial Fei. When a certain time period passes after the quenching, the interstitial Fei is gradually paired with B. It has been found that the presence of Fe-B pairs hinders Fe concentration in a denuded zone from being sufficiently reduced by the conventional IG technique and that it is possible to reduce the Fe concentration in the denuded zone by reducing the number of Fe-B pairs and substituting interstitial Fei for them. According to the findings, the following experiment was conducted. FIG. 4 is a diagrammatic view which serve to illustrate the principle of the present invention. A p-type silicon wafer 1 is placed on a heating pad 3, and a light source 2 is disposed above the wafer 1. The light source 2 may be a white light source such as a halogen lamp or an ultraviolet rays light source. Since light has energy sufficient to dissociate Fe-B pairs, particularly large power is not needed. For example, it is sufficient that a 50-W light source be converged by a reflection mirror. After the same heat treatments for forming an IG layer as those applied to Group No. 3 (1000° C., 30 minutes; 650° C., 6 hours; and 1000° C., 30 minutes) and a similar Fe contamination treatment (the dipping of each wafer sample in a 60% HNO 3 solution containing 500 ppm of Fe ions) were carried out, the following gettering treatments were performed. Group No. 4: Heated at 200° C. for 6 hours; Group No. 5: Irradiated by ultraviolet rays for six hours; and Group No. 6: Heated at 200° C. and simultaneously irradiated by ultraviolet rays for six hours. The results are shown in FIG. 2, and the DLTS characteristics of the respective groups No. 3-6 are shown in FIGS. 5(a)-5(d). As can be seen from FIG. 2, the Fe concentration of Group No. 4 is as low as approximately one third of that of Group No. 3. The Fe concentration of Group No. 5 exposed to ultraviolet rays only is substantially the same as that of Group No. 3. This shows that, although the total amount of Fe does not change, the Fe concentration of Fe-B pairs decreases and that of interstitial Fei increases. The IG treatment applied to Group No. 6 is the most effective in that the Fe concentration is as low as approximately 1/10 the Fe concentration of Group No. 3. No crystal defect was observed in the denuded zone of each wafer sample. The required heating temperature and time can be obtained by using the diffusion coefficient D of Fei which is given by the following equation described in the above-recited document (1): D=1.3×10.sup.-3 exp(-0.68[eV]/kT) cm.sup.2 /sec This equation is illustrated in FIG. 6 in graphic representation, and the following relations are obtained: D=5.7×10.sup.-15 cm.sup.2 /sec (at 25° C.) D=7.5×10.sup.-11 cm.sup.2 /sec (at 200° C.) To assure a diffusion length x of 10 μm which is assigned to a width of the denuded zone DZ, 10 μm is substituted for x in x =√Dt (t: diffusion time), then t=4.9×10.sup.4 h (at 25° C.) t=3.7 h (at 200° C.) Therefore, if the required processing time is to be reduced within reasonable duration, it is desirable that the required heating temperature be higher than about 150° C. (it takes approximately 28 hours at 150° C.). However, since the amount of Fe precipitation gradually increases a the heating temperature becomes higher, it is not desirable that 220° C. be exceeded. Once Fe precipitates are produced, they are not reversibly converted to interstitial Fei even by light irradiation and it is therefore impossible to getter the Fe precipitates. When these conditions are considered, it is desirable that the heating temperature is selected to be at or around 200° C. It is practically sufficient that the heating time be four hours or more. It is desirable that the gettering treatment according to the present invention be carried out prior to metalization for forming a wiring pattern of aluminum throughout the entire wafer processes. This is because, once a metal layer is formed on a wafer surface, the effect of light irradiation according to the present invention is impaired. FIG. 7 is a flow chart showing a semiconductordevice manufacturing process to which the techniques of the present invention is applied. In Step 10, a silicon wafer is subjected to heat treatments in accordance with the above-described schedule for the purpose of forming an IG layer. Subsequently, the wafer is passed through wafer processes 12 including a number of process steps other than a metal layer forming step 16. In the present invention, a gettering step 14 is performed before Step 16. This is because light irradiation is effectively carried out. It is desirable that, after gettering has been completed, a hightemperature processing step be not performed. Subsequent steps such as metal layer forming step 16, an assembly step 18, a packaging step 20, a test step 22 and a shipping step 24 are substantially the same as those of the conventional process. The concentration of heavy metal impurities in a normal Si crystal (CZ, FZ) is reported to be on the order of 10 9 cm -3 . However, a silicon wafer may be exposed to contamination up to 10 10 -10 14 cm -3 in wafer processes. Accordingly, it is effective to perform the gettering treatment according to the present invention in a final stage of the wafer processing. When the present invention was applied to a CCD type image sensor, the concentration of Fe-B was improved to 1×10 11 cm -3 or lower from the data of 8×10 11 cm -3 of the prior art. The failure of output signals of dark current (DS) was reduced to 1/10. While the above embodiment has been explained with reference to Fe which is one kind of heavy metal impurities, the present invention may be likewise applied to Cr impurities since it is known that Cr also forms a Cr-B pair. It will be appreciated from the foregoing that the present invention makes it possible to effectively reduce dark current in a CCD type image sensor which handles analog signals. However, the present invention is not limited to the above-described range of applications, and is also effectively applied to the fabrication of ICs including MOS transistors or bipolar transistors with the object of reducing leakage current. In particular, a combination of the present invention and DRAMs provides marked effects since the power consumption of DRAMs can be reduced by preventing leakage current during their refreshing operations. When p-type silicon substrates are utilized, the above-described techniques such as the formation of an IG layer and a gettering treatment may be similarly applied. While the present invention has been described with respect to what is presently considered to be the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment. To the contrary, the present invention is intended to cover various modifications included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent functions.

A method of gettering heavy metal impurities from p-type silicon substrates comprises the prior step of forming an intrinsic gettering layer covered with a surface denuded zone in the silicon substrate by subjecting the substrate to heat treatments which form the intrinsic gettering layer having a large density of crystal microdefects compared to the density of crystal microdefects in the denuded zone; then the step of performing most of the required wafer processes other than the step of forming a metal layer; and subsequently the gettering step of heating the silicon substrate to a predetermined temperature and simultaneously irradiating the substrate with light rays, the predetermined temperature being selected to be within the temperature range 150° C. to 220° C., preferably around 200° C.

CROSS-REFERENCE TO RELATED APPLICATION This is a divisional application of co-pending application U.S. Ser. No. 534,114 filed Dec. 18, 1974 now Pat. No. 3,970,651 which in turn is a continuation-in-part of application Ser. No. 431,251 filed Jan. 7, 1974, now abandonded. BACKGROUND OF THE INVENTION (1) Field of the invention. The crystalline cephalosporin derivative of the present invention possesses in general the usual attributes of that family of antibacterial agents and is particularly useful in the treatment of bacterial infections by both oral and parenteral administration. (2) Description of the prior art. The literature concerning this class of antibacterial agents has been reviewed frequently; two recent reviews are The Cephalosporins Microbiological, Chemical and Pharmacological Properties and Use in Chemotherapy of Infection, L. Weinstein and K. Kaplan, Annals of Internal Medicine, 72, 729-739 (1970) and Structure Activity Relationships Among Semisynthetic Cephalosporins, M. L. Sassiver and A. Lewis, Advances in Applied Microbiology, edited by D. Perlman, 13, 163-236 (1970), Academic Press, New York. Additional reviews which pay particular attention to the patent literature are found in U.S. Pat. Nos. 3,776,907, 3,776,175 and 3,759,904. Solvates, and hydrates in particular, are often encountered in the cephalosporin field, e.g. U.S. Pat. Nos. 3,280,118, 3,502,663, 3,655,656, 3,692,781, 3,708,478 and 3,714,157. 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid is a new cephalosporin, also called BL-S640, which is described and claimed by our colleagues David Willner and Leonard B. Crast, Jr. in U.S. application Ser. No. 318,340 filed Dec. 26, 1972; the entire disclosure of that application is incorporated herein by reference. Application Ser. No. 318,340, discloses isolation of a 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid methanolate. SUMMARY OF THE INVENTION The dual problems confronting applicants were the need for a practical method for purifying 7-[D-α-aminoα-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol- 5-ylthiomethyl)-3-cephem-4-carboxylic acid to the high degree necessary for human use and the provision of a form of this drug which could be formulated and administered both orally and parenterally in an aqueous suspension without loss of biological activity and without deleterious changes on standing such as losing crystallinity, not suspending evenly, oiling, clumping, settling out and becoming tracky. These problems were complicated by the fact that in water at alkaline pH, e.g. 7.0 or higher, this compound degrades very rapidly, as by loss of the thiol moiety. In addition, the crude product obtained in chemical production was rather heavily contaminated with residues of the reagents and with various decomposition products from which it could not be separated in reasonable yield by recrystallization or the other usual techniques such as washing with solvents. Efforts to crystallize the zwitterion or a hydrate thereof failed to give a crystalline product and failed to give substantial purification. No way was found to remove the solvents from solvates in order to obtain essentially anhydrous pure compound and the products so obtained became tacky. The methanolate was undesirable for human use having in mind the known toxicity of that alcohol and in addition its use provide little purification as measured by any increase in biopotency, decrease in color and reduction in content of impurities. An ethanolate was prepared and found to fail to achieve the objectives. Its formation was not accompanied by purification although it was crystalline. In addition, when suspended in water the ethanolate gradually lost its ethanol to change into a solid tacky form which lost crystallinity, did not suspend evenly and gummed in time. The objectives of the present invention were achieved by the provision according to the present invention of crystalline 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid 1,2-propylene glycolate and as a preferred embodiment crystalline 7-[D-α-amino-α(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid 1,2-propylene glycolate having from 1.0 to 1.6 moles of 1,2-propylene glycol per mole of cephalosporin zwitterion and, most particularly, crystalline 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4 -carboxylic acid mono-propylene glycolate containing 1 mole of 1,2-propylene glycol per mole of cephalosporin zwitterion. There is also provided by the present invention the process for the preparation of crystalline 7-[D-αamino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid 1,2-propylene glycolate; which process comprises adjusting upward the pH of an acidic solution having a pH below about 2.0 of 7-[D-α-amino-α-(p-hydroxphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid in aqueous 1,2-propylene glycol by the addition of a base to raise the pH to at least 4.0 and preferably in the range of 4.0 4.0- 5.0 thus precipitating the crystalline propylene gylcolate product which is recovered from the solution by conventional methods such as filtration or centrifugation. The acidic solution of 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid in the above process may be prepared by adding sufficient acid to an aqueous slurry of the cephalosporin zwitterion or a hydrate or solvate thereof and 1,2-propylene glycol so as to lower the pH of the reaction mixture to below about 2.0, most preferably in the range of about 0.9 to 1.5 and to effect solution of the cephalosporanic acid. The most preferred form of the cephalosporin for use in this process is the methanolate. The pH of the solution is then raised by addition of sufficient base to effect crystallization of the propylene glycolate product. The most preferred procedure is to slowly add base to a solution having a pH of 1.5 or below to bring the pH to about 1.7 whereupon insoluble impurities precipitate out of solution. The reaction mixture is optionally but preferably carbon-treated and the insoluble products are then separated as by filtration. The acidic solution is adjusted by addition of base to a pH above 4 and preferably in the range of 4.0 to 5.0 at which point the desired product crystallizes from the solution. The product is recovered by conventional procedures, preferably by filtration, and then washed and dried to give the crystalline propylene glycolate having from 1.0 to 1.6 moles of 1,2-propylene glycol per mole of cephalosporin zwitterion. As illustrated below, the propylene glycolate product of the present invention is crystalline and substantially free of the impurities found in samples of 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2, 3 -triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid made by practical commercial processes. When suspended in water it does not lose biological activity, lose crystallinity, suspend unevenly, oil, clump, settle out or become tacky. As a solid under the usual stringent test conditions it loses no more than ten percent of its bioactivity when stored for one month at b 56° C. At that temperature and also at 100° C. it is far more stable in the solid form than the ethanolate. Either acetone or methanol or ethyl acetate washes can be used to remove excess propylene glycol from the product of the present invention; that is not possible with the other solvates including those containing acetone or ethyl acetate. In vitro crystalline 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid 1,2-propylene glycolate exhibits the potency and spectrum of activity reported in the above-referenced application Ser. No. 318,340 in a qualitative sense and usually also quantitatively except when it is possible to observe slightly less activity due to its content of the biologically inert propylene glycol. In vivo the results are substantially the same (within the experimental variation inherent in such work) because the product is dosed on a potency basis in terms of the zwitterion as illustrated in the examples. In the treatment of bacterial infections in man crystalline 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid 1,2-propylene glycolate is administered either orally or parenterally, as preferred by the physician, in an amount of from about 5 to 200 mgm./kg./day and preferably about 5 to 20 mgm./kg./day in divided dosage, e.g. three to four times a day. It is administered in dosage units containing, for example, 125, 250 or 500 mgm. of active ingredient with suitable physiologically acceptable carriers or excipients. The dosage units are in the form of capsules or tablets containing the solid product for oral use or in the form of liquid preparations such as aqueous suspensions for either oral or parenteral administration. A preferred embodiment of the present invention is the process for the preparation of cyrstalline 7-[D-α-amino-α-(p-hydroxphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid mono-propylene glycolate, which process comprises (1) providing an aqueous solution of 7-[D-α-aminoα-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid and a water-soluble organic compound containing a ketone functional group; (2) adjusting the pH of the solution to about 4.5; (3) diluting the solution with sufficient water to effect precipitation of insoluble impurities; (4) separating the aqueous solution from the insoluble impurities; (5) adding to the aqueous solution sufficient 1,2-propylene glycol to effect crystallization of the desired mono-propylene glycolate; and (6) recovering the crystalline product. A most preferred embodiment of the present invention is the process for the preparation of crystalline 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid mono-propylene glycolate; which process comprises (1) providing an acidic aqueous solution of 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid and a water-soluble ketoacid selected from pyruvic acid or levulinic acid, said solution having a pH of about 2.0 or below; (2) adjusting the pH of the solution to about 4.5; (3) diluting the solution with sufficient water to precipitate out insoluble impurities; (4) separating the aqueous solution from the insoluble impurities; (5) adding to the aqueous solution sufficient 1,2-propylene glycol to effect crystallization of the desired mono-propylene glycolate; and (6) recovering the crystalline product. The crystalline mono-propylene glycolate may be prepared according to the above process by treating an aqueous suspension of 7-[D-α-amino-α-(p-hydroxyphenyl)-acetamido]-3-(1,2,3,-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid or a hydrate or solvate thereof, preferably a methanol solvate, with a sufficient amount of a water-soluble organic compound containing a ketone functional group to form an aqueous solution of the cephalosporanic acid. In general any water-soluble organic compound containing a ketone moiety may be employed including such compounds as water-soluble ketones, e.g. acetone; ketoacids, e.g. pyruvic acid, levulinic acid, acetoacetic acid, ketoglutaric acid, or salts of ketoacids; and hydroxy-ketones, e.g. dihydroxy-acetone or fructose. The preferred compounds are water-soluble ketoacids. For reasons of availability and cost, the most preferred ketoacids for use in the process are pyruvic acid and levulinic acid. The cephalosporin starting material may be the zwitterion free acid or a hydrate or solvate thereof but is preferably the methanolate because of the greater rate of dissolution of this derivative. If a complete solution is not obtained upon addition of the ketone-containing organic compound, the pH may be adjusted by addition of acid or base to effect solution. In the preferred procedure a water-soluble ketoacid is used to lower the pH of the aqueous reaction mixture to about 2.0 or below whereupon the cephalosporanic acid goes into solution. If complete solution is not achieved by use of the ketoacid per se, the reaction mixture may be adjusted as by addition of a mineral acid to maximize solubility. The aqueous solution is then adjusted to a pH of about 4.5 by addition of a suitable acid or base. When the preferred ketoacids are used, the pH of the acid solution is raised to the 4.5 level by addition of base, e.g. NaOH, preferably with rapid stirring. The solution is then diluted with water to allow any water-insoluble impurities to precipitate out. The amount of dilution is not critical but an approximate 1:1 dilution in this step has been found to result in high purity product. The temperature of the reaction mixture during the above-mentioned steps is not critical. It is preferred, however, to perform these process steps (especially the pH 4.5 adjustment step and dilution step) at a temperature of room temperature or below, most preferably at a temperature in the range of about 5°-20° C., so as to maximize the amount of insoluble impurities formed in the dilution step. After the dilution step the solid impurities may be separated by conventional procedures, e.g. filtration, from the aqueous solution which contains the cephalosporanic acid and ketone-containing compound. The precise nature of the product in solution is not known, but is believed to be some type of loosely bound soluble physical complex of the cephalosporin zwitterion and keto compound. In any event the use of the keto compound allows the cephalosporin zwitterion to remain in solution at pH 4.5 while the insoluble impurities (including substantially all of the colored impurities) precipitate out. After removal of any solid impurities the aqueous solution is preferably carbon-treated with activated carbon and filtered prior to the propylene glycol addition step. The aqueous solution is next treated with sufficient 1,2-propylene glycol to induce crystallization of the mono-propylene glycolate which is then recovered as by filtration, washed and dried. The mono-propylene glycolate prepared according to the above process is a substantially colorless, high potency, crystalline material with excellent color stability and thermal stability. It is especially advantageous for use in aqueous suspensions since on suspension in water it does not lose biological activity or crystallinity and does not oil, suspend unevenly, clump, settle out or become tacky as was the case with other solvates tested. When proper allowance is made for the biologically inert propylene glycol, the mono-propylene glycolate exhibits substantially the same potency and spectrum in vivo and in vitro as the zwitterion product disclosed in application Ser. No. 318,340. In the treatment of bacterial infections in man the crystalline mono-propylene glycolate is administered either orally or parenterally, as preferred by the physician, in an amount of from about 5 to 200 mgm./kg./day and preferably about 5 to 20 mgm./kg./day in divided dosage, e.g. three to four times a day. It is administered in dosage units containing, for example, 125, 250 or 500 mgm. of active ingredient with suitable physiologically acceptable carriers or excipients. The dosage units are in the form of capsules or tablets containing the solid product for oral use or in the form of liquid preparations such as aqueous suspensions for either oral or parenteral administration. The present invention besides providing crystalline 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid 1,2-propylene glycolate for use in pharmaceutical formulations also provides methods for purifying 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid which, as mentioned above, is unable to be purified in reasonable yield by normal purification techniques. If in the processes described above impure 7-[D-α-amino-α-(p-hydroxyphenyl)-acetamido]-3(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid is used, the cephalosporin may be recovered in the form of the substantially pure crystalline 1,2-propylene glycolate, said propylene glycolate having from 1.0- 1.6 moles of 1,2-propylene glycol per mole of cephalosporin zwitterion and, most preferably, 1.0 mole of 1,2-propylene glycol per mole of cephalosporin zwitterion. Substitution of methanol in the procedures described above for the 1,2-propylene glycol used therein produces a crystalline mono-methanolate which may be used as a starting material in the preparation of the crystalline propylene glycolate product of the present invention. There is also provided by the present invention a stable aqueous suspension useful for the treatment of bacterial infections in mammals comprising at least 30 mgm./ml., and preferably at least 125 mgm./ml. of crystalline 7-[D-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid 1,2-propylene glycolate, said propylene glycolate preferably containing 1.0- 1.6 moles of 1,2-propylene glycol per mole of cephalosporin zwitterion and most preferably 1.0 mole of 1,2-propylene glycol per mole of cephalosporin zwitterion, and having a pH in the range of 2.8- 5 and preferably in the range of 2.8- 3.5. Bioassays Bioassays were turbidometric against S. aureus 209P (A.T.C.C. 6538P) using as the standard a sample of 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid 1,2-propylene glycolate with an assigned potency of 820 mcg./mgm.; the sample contained by chemical analysis 16.7% 1,2-propylene glycol and 0.3% water. The anhydrous zwitterion 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid was assigned a potency of 1000 mcg./mgm. and thus a sample containing 16.7% 1,2-propylene glycol and no other impurities at all (including no water and no excess or unbound 1,2-propylene glycol) would have a calculated potency of 833 mcg./mgm. Calculated percentage contents of 1,2-propylene glycol are 14.1% for 1.0 mole and 20.8% for 1.6 mole of the glycol per mole of zwitterion. The molecular weight of the zwitterion is 462.38. IR and NMR spectra were run on the same standard sample and the functional group data from the spectra are summarized as follows: __________________________________________________________________________IR (KBr) 2400-3600 cm.sup..sup.-1 (broad overlapping peaks)-amide NH NH.sub.3.sup.+, OH 1780 β-lactam C0 1700 amide C0 1570 COO.sup.- 1515 aromatic CCNMR (DMSO,dil. DCl)7.96 ppm δ singlet 1H, H.sub.a6.7 -7.6 multiplet, 4H, H.sub.b5.7 doublet, 1H, H.sub.c4.9 -5.2 multiplet, 2H, H.sub.d, H.sub.e3.2 -4.2 multiplet, 8H*, H.sub.f, H.sub.g, H.sub.j, H.sub.k1.1 doublet, 4H*, H.sub.n__________________________________________________________________________*The integral values indicate 1.33 moles of propyleneglycol per mole of BL-S640 zwitterion (18.3% by weight-uncorrected for moisture). ##STR1## A sample of the 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid mono-propylene glycolate as prepared according to the method of Example 5 was found to have a calculated potency of 865 mcg./mg.; the sample contained by chemical analysis 15.6% 1,2-propylene glycol and 0.3% water. IR and NMR spectra were run on the same sample of the mono-propylene glycolate and the functional group data from the spectra are summarized as follows: ______________________________________IR (KBr)2400-3600 cm.sup..sup.-1 (broad overlapping peaks)- amide NH, NH.sub.3.sup.+, OH1780 β-lactam C01705 amide C01570 COO.sup.-1515 aromatic CCNMR (DMSO, dilute DCl)7.98 ppm δ singlet, 1H, H.sub.a6.7-7.6 multiplet, 4H, H.sub.b5.68 doublet, 1H, H.sub.c4.9-5.2 multiplet, 2H, H.sub.d, H.sub.e3.2-4.2 multiplet, 7H, H.sub.f, H.sub.g, H.sub.j, H.sub.k1.1 doublet, 3H, H.sub.n______________________________________ The integral values indicate 1 mole of propylene glycol per mole of BL-S640 zwitterion. ##STR2## STARTING MATERIALS D-(-)-2-(p-hydroxyphenyl)glycyl chloride hydrochloride was prepared in a high state of purity and very efficiently by the following procedure. 10.0 g. (about 0.06 moles) of D-(-)-2-(p-hydroxyphenyl)glycine (U.S. Pat. No. 3,489,752) was slurried in 100 ml. of dioxane. The slurry was stirred and COCl 2 (phosgene) was passed in while the slurry temperature was held at 50°-58° C. The COCl 2 was passed in for a total time of 3.5 hours. A yellow solution was obtained. The solution was purged with nitrogen to expel the excess COCl 2 . HCl gas was bubbled through the solution for 2.5 hours. The solution was stirred and a small amount was diluted with some ether to obtain some crystals which were added to the batch as seed. The solution was stirred at 20°-25° C. for 16 hours. The resulting slurry of crystalline D-(-)-2-(p-hydroxyphenyl)glycyl chloride hydrochloride was filtered to collect the product. The filter-cake was washed with dioxane and methylene chloride and then dried in a vacuum desiccator over P 2 O 5 . The yield of D-(-)-2-(p-hydroxyphenyl)glycyl chloride hydrochloride was 7.3 g. Ir - excellent. ______________________________________Elemental Analysis: C1 C H N______________________________________Theory 31.93 43.14 4.09 6.37Found 31.96 42.46 4.22 6.56Acid Chloride Assay:Acid Chloride - 98.6%Free COOH - NoneFree HCl - None______________________________________ Acid Chloride Assay: Acid Chloride: 98.6% Free COOH: None Free HCl: None D-α-t-Butoxycarbonylamino-α-(p-hydroxyphenyl)acetic acid In a three necked flask equipped with a reflux condenser, overhead stirrer and thermometer, there was placed a well-mixed mixture of 8.36 g. (0.05 mole) of D-(-)-p-hydroxyphenylglycine and 3.02 g. (0.075 mole) of magnesium oxide in 120 ml. of 50% aqueous dioxane. The mixture was stirred for 1 hour and then treated with 10.74 g. (0.075 mole) of t-butoxycarbonylazide. The mixture was then stirred and heated at 45°-50° for 17 hours under N 2 . The solution was diluted with 400 ml. of H 2 O and extracted twice with 300 ml. of ethyl acetate. The aqueous phase was acidified with 10% citric acid solution to pH 4 and saturated with NaCl. The aqueous mixture was extracted with 3× 400 ml. of ethyl acetate. The solution was dried over Na 2 SO 4 and the solvent evaporated. The residue was triturated with "Skellysolve B" to yield D-α-t-butoxycarbonylamino-2-(p-hydroxyphenyl)-acetic acid as a solid weighing 10.4 g. (78.5%). 7-[D-α-t-Butoxycarbonylamino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid To a suspension of 7-amino-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid (6.0 g., 19.0 mmole) in 100 ml. dry methylene chloride there was added 8.5 ml. of 1,1,1,3,3,3-hexamethyldisilazane (40.9 mmole). The mixture was stirred and heated at reflux for 4 hours at which time a clear solution was obtained. The solvent was evaporated and the residual oil was subjected to high-vacuum overnight at room temperature. The foamy residue was dissolved in 85 ml. of dry THF and cooled to about -15° before introduction into the subsequent reaction mixture. D-α-Butoxycarbonylamino-α-(4-hydroxyphenyl)acetic acid, (4.4 g., 16.5 mmole) was dissolved in 145 ml. dry THF. The solution was stirred and cooled to -20°. N-methylmorpholine (1.6 g., 16 mmoles) and isobutylchloroformate (2.3 g., 16.8 mmole) were added in succession at such rate that the temperature of the mixture did not rise about -10°. The resulting mixture was then stirred for 20 minutes at -12° to -15°. It was then cooled to -20° and the THF solution of silylated 7-amino-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid was added all at once. The temperature rose to about -12°. External cooling was discontinued until the temperature rose to 0°. At this point an ice-water bath was applied and the mixture stirred for three hours at 2°-3°. This was followed by a period of one hour without external cooling, the temperature rising to 20°. A total of 30 ml. methanol was added and the stirring continued for 15 minutes at room temperature. After evaporating the solvents under reduced pressure, the residue was suspended in 300 ml. ethyl acetate. The suspended solid was filtered off, 11.8 g. The ethyl acetate solution was extracted three times with NaHCO 3 (5%) solution. The combined sodium bicarbonate extracts were cooled in an ice-bath, layered with ethyl acetate and acidified to a pH of 2.5 with 42.5% H 3 PO 4 . The phases were shaken and then separated. The ethyl acetate solution was then dried by passing it through sodium sulfate and then evaporated to about 15-20 ml. This solution was then added dropwise to stirred cyclohexane (˜400 ml.) contained in an Erlenmeyer flask. After stirring for 1/2 hour the precipitated solid was collected by filtration. The collected solid 7-[D-α-t-butoxycarbonylamino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cepham-4-carboxylic acid was air dried. It weighed 1.75 g. 7-[D-α-t-Butoxycarbonylamino-α-(p-hydroxyphenyl)-acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid, 3.5 g., was dissolved in 80 ml. HCOOH, 98-100%, and stirred for 2 hours at room temperature. The HCOOH was evaporated under reduced pressure (aspirator bath temperature not above 40°) and finally azeotroped 3 times with 30 ml. of toluene. The solid was dried overnight under high vacuum over P 2 O 5 . A total of 3.5 g. of foam was obtained. The foam, 2 g., was stirred with 300 ml. of H 2 O: CH 3 OH (8:2). The solvent was filtered from some solid (0.3 g.), charcoaled with 700 mg. of "Darko KB", filtered through diatomaceous earth ("Celite" and freeze-dried to yield 0.9 g. of crude 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid. To crystallize the following procedure was used. A suspension of 0.2 g. of the crude material in 6 ml. of 99% methanol was heated in a test tube to boiling. Immediately the heating was discontinued and the melt triturated with seeds. The melt solidified to a crystalline mass. In this manner a total of 0.211 g. of 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid was obtained from 0.400 g. of crude material. The material was dried at 56°/0.1 mm over P 2 O 5 for 20 hrs., m.p. > 200° dec. IR and NMR are consistent with structure. The NMR indicates also the presence of 1/3 mole of CH 3 OH. Anal. Calcd. for C 18 H 18 N 6 O 2 .sup.. H 2 O.1/3CH 3 OH: C, 44.83; H, 4.38; N, 17.10; S, 13.09. Found: C, 43.97; H, 4.36; N, 15.84; S, 6.18. A total 6.5 g. (11.55 mmole) of 7-[D-α-t-butoxycarbonylamino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid was dissolved in 175 ml. 98-100% formic acid under anhydrous conditions. The mixture was stirred at room temperature for 2.5 hours. Part of the solution, 125 ml., was evaporated under reduced pressure to an amber oil. The oil was then azeotroped 3 times with 70 ml. of toluene under reduced pressure. The residue was suspended in an 80:20 H 2 O--CH 3 OH solution (700 ml.) and stirred for 0.5 hour until most of the solid dissolved, then filtered. The filtration was treated with 1.5 g. of ("Darko") charcoal for about 20 minutes. The charcoal was filtered off through a "Celite" pad. The solution was then freeze-dried in 9 separate 100 ml. round bottom flasks. The freeze-dried material weighed 2.415 g. It was recrystallized in batches of 0.200 g. as described above to yield a total of 0.923 g. 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid. NMR was consistent, indicating the presence of a 1/3 mole of CH 3 OH. Anal. Calcd. for C 18 H 18 N 6 O 5 S 2 .sup.. H 2 O. 1/3CH 3 OH: C, 44.83; H, 4.38; N, 17.10; S, 13.09. Found: C, 45.77, 44.36; H, 4.44, 4.34; N, 16.61, 16.52; S, 13.01, 13.01. The acylation of 7-amino-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid (7-TACA) to BL-S640 has been carried out in methylene chloride with D-(-)-p-hydroxyphenylglycyl chloride hydrochloride. The yield to BL-S640 methanol solvate was about 45% on a biopotency basis. There was about 15% activity in the mother liquor and about 25% insoluble solids which is unreacted 7-TACA and 7-TACA decomposition product with degraded β-lactam. The process essentially entails silylation with HMDS of 7-TACA in methylene chloride and then acylation with acid chloride.sup.. HCl at 0°-5° C. followed by methanol quench. The reaction is then stripped of methylene chloride and the methanol solution is "Darco KB" treated. The filtrate is vacuum concentrated and then adjusted to pH 4.8- 5.0 with concentrated NH 4 OH, seeded and crystallized. ##STR3## ______________________________________MATERIALS: (Based on 1.0 kg. of 7-TACA)Reagent g ml. Moles______________________________________7-TACA 1000.0 ˜3.20D-(-)-p-hydroxyphenyl- 797.0 ˜3.60 glycylchloride.HClHMDS 965.0 1245.0 ˜5.95 (Hexamethyldisilazane)DMA.HCl 320.0 (30% in MeCl.sub.2)DMA 480.0 ˜3.78 (Dimethylaniline)Methylene chloride As required (Dry <0.01% KF)Methanol " (Dry 0.01% KF)Ammonium hydroxide ""Darco KB" " (activated charcoal)Imidazole 21.8 0.32______________________________________ PROCEDURE 1. 1000 g. (3.20 moles) of 7-TACA is added to 25 liters of dry methylene chloride (K.F. H 2 O <0.01%). The slurry is stirred and 1245 ml. (about 5.95 moles) of HMDS is added to the slurry. 2. The slurry is warmed to reflux and dry nitrogen gas is bubbled through the slurry. The refluxing is continued until complete solution and no settleable solids are noted. Batches of 7-TACA were refluxed for 12-22 hours to obtain a solution that was turbid. 3. After the silylation step is completed, the solution is cooled to about 15°-20° C. and 320 ml. of DMA.sup.. HCl (30% in MeCl 2 ) is added followed by 480 ml. of DMA (dimethylaniline) and 21.8 g. of imidazole. The reaction mix is chilled to 0°-5° C. and 797 g. (3.60 moles) of D-(-)-p-hydroxyphenylglycylchloride.sup.. HCl is added in 5 increments over a period of one hour. The slurry is stirred at 0°-5° C. for 10-12 hours or until all the acid chloride goes into solution. 4. The reaction mixture is warmed slowly over 3 hours to 20° C. and held for 2 hours at 20° C. Complete solution of the acid chloride should be noted. 5. 8.3 Liters of dry methanol (KF <0.01%) is added to the solution within one minute with good stirring. The mixture is stirred for 10-15 minutes and then immediately filtered very rapidly to remove insolubles. (In the laboratory, the filtration was carried out on a Buchner funnel and the cake was washed with a wash made up of two parts dry MeCl 2 and one part dry methanol.) This filtration must be done rapidly and the filtration setup prepared before hand so the filtration can be carried out as stated. The filtrate and wash had solids coming out after filtration. It is not known if these solids were product (possible .sup.. HCl salt). It may be that as the reaction with methanol takes place or due to take up of moisture in the laboratory hydrolysis of the silyl ester takes place and product starts to come out. The dark solids filtered out in this step contain some product, 7-TACA and degraded 7-TACA. The wash on the cake scales up to about 10 liters of MeCl 2 -MeOH (2-1). 6. The filtrate and wash is vacuum concentrated to remove the MeCl 2 and dry methanol is added as necessary. The solution is concentrated to about 15-18 liters and 600 g. of Darco KB" is added. The slurry is stirred for 20-25 minutes and then the slurry is filtered through a diatomaceous earth ("Dicalite") precoat and the cake is washed well with 8.0 liters of methanol. This treatment usually gives a yellow-orange filtrate. 7. The filtrate is vacuum concentrated to 12.0- 13.0 liters and 480 ml. of deionized water is added to the solution. The pH will be in the 2.4- 3.2 range. The solution is titrated slowly over 30 minutes to pH 4.8- 5.0 with concentrated ammonium hydroxide. A scaleup of laboratory results would require 420- 440 ml. of ammonium hydroxide. The solution is seeded when the pH has been adjusted to 4.0. The pH adjustment is carried out at 20° C. after which the slurry is stirred for one hour at 20° C. and then chilled to 0° C. for 16 hours. In the laboratory, after 3 hours stirring in an ice bath the beaker is packed in ice and held in the refrigerator overnight. Crystal growth on the sides of the beaker has always been noted after overnight holding. It is not known at this time if shorter hold time is adequate. However, 3 hours is not adequate from these visual observations. The precipitated product is collected by filtration, washed with MeOH (about filtrate volume) and dried at 45°. The usual yield is 750- 770 g. of methanol solvate of 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid. This procedure is an anhydrous one and all precautions are necessary to avoid water contamination or sweating that could cause hydrolysis of the silyl ester and subsequent poor acylation. The following examples are given in illustration of, but not in limitation of, the present invention. All temperatures are given in degrees Centigrade. "Tween 80" is generically known as "Polysorbate 80" and is a complex mixture of polyoxyethylene ethers of mixed partial oleic esters of sorbitol anhydrides. The 1,2-propylene glycol used is also known as Propylene Glycol U.S.P. Tetrahydrofuran is abbreviated as THF. "Skellysolve B" is a petroleum ether fraction of b.p. 60°-68° C. consisting essentially of n-hexane. DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLE 1 Preparation of Crystalline 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid Methanolate 1. Fifty grams of 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido] -3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid is slurried in 250 ml. of 95% V/V methanol/water (95% methanol) solution, at 22°-25° C. 2. Concentrated hydrochloric acid is added with rapid stirring to a pH of 1.3- 1.5. A solution or near solution is obtained. 3. Adjust the pH to 1.7 with triethylamine. 4. Add 7.5 grams of activated characoal ("Darco G-60") and slurry for 0.5 hours. 5. The carbon is removed by filtration and washed with 75 ml. of methanol which is added to the filtrate. Steps 2, 3 and 4 should be completed within 5 hours. 6. The combined wash and filtrate of Step 5 is rapidly stirred. Triethylamine is added over a 5 minute period to pH 4.5. Crystallization starts in about 1-3 minutes. The mixture is slurried for one hour. 7. The crystals are collected by filtration, washed with 100 ml. of methanol and vacuum dried at 56° C. - 24 hours. Bio yield 75-90%; bio-assay= 850-900 mcg./mg.; NMR-IR= Consistent for 1 mole of methanol; % H 2 O, KF= 2-4.0. Preparation of Crystalline BL-S640 1,2-Propylene Glycolate 1. Twenty-five grams of the 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid methanolate prepared above is slurried in 150-200 ml. of 75% V/V propylene glycol-water solution at 20°-25° C. 2. Concentrated hydrochloric acid is added to a pH of 1-1.2 to obtain a solution or near solution. 3. Triethylamine (TEA) is slowly added with rapid stirring to obtain a pH of 1.7- 1.8. 4. Five grams of "Darco G-60" is added and the mixture is slurried for 0.5 hour. The carbon is removed by filtration (filtration is slow, an 18.5 cm. SS No. 576 paper is suggested). The carbon filter cake is washed with 40 ml. of 75% V/V propylene glycol water solution. The wash is added to the filtrate. Steps 2, 3 and 4 above should be completed within 5 hours. 5. Triethylamine is added to pH 4.5 over a 10 minute period to the rapidly stirring filtrate - wash mixture of Step 4. Crystals form in about 1-3 minutes. The mixture is slurried for one hour. 6. The crystals of the 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid propylene glycolate are collected by filtration. Filtration is slow (a 12.5- 15.0 cm. SS No. 604 paper is suggested). The crystals are washed consecutively with 50 ml. of 75% propylene glycol, 50 ml. of methanol, 50 ml. of acetone and vacuum dried at 56° C. for 24 hours. Biological yield: 80-95%. Properties of 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid propylene glycolate. a. Bio-assay= 750-790 mcg./mg. b. IR-NMR= Consistent for a structure containing 1.3- 1.5 MOLES of propylene glycol (17-19% propylene glycol). No loss of the 3-triazole side chain evident. c. % Water, K.F.= 1-3.0. d. Crystal morphology= 100% crystalline microcrystals, triangular shaped. e. M.P.= 182°-184° C. (D, hot stage). f. [α] d .sup. 25 (C= 1%; 1N-HCl)= +53°. g. Water solubility= Approximately 10 mg./ml. in water at 23° C. h. Loss of bioactivity on storage at elevated temperatures: 100° C., 24 hours= <6%; 48 hours= <12%; 56° C., 1 month= <10%. EXAMPLE 2 Example 2______________________________________MATERIALS Wt.,g. Vol.,ml. Moles______________________________________7-[D-α-Amino-α-(p- 1,000 2.02hydroxyphenyl)acetamido] -3-(1,2,3-triazol-5-yl-thiomethyl)-3-cephem-4-carboxylic acid methanolate(Note 1)6N HCl 425-460Triethylamine ˜330Carbon 50Propylene glycol 5,650(1,2-propanediol)Ethyl acetate 3,400Methylene chloride 800______________________________________ PROCEDURE 1. Charge a suitable vessel equipped for stirring and pH control with 1.5 liters of propylene glycol and 1.5 liters of deionized water. 2. Add 1000 g. of 7-[D-α-amino-α-(p-hydroxphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid methanolate into the above propylene glycol - water mixture (1:1). 3. Under good agitation, acidify the slurry with about 425 ml. of 6 N HCl to pH 0.9- 1.3 over 15 minutes at 25° C. A dark, clear solution should be obtained. 4. Immediately adjust the solution to pH 1.4- 1.7 with triethylamine (TEA). It only takes 20-30 ml. A small amount of white solid is precipitated out. The precipitate is presumed to be p-hydroxyphenyl glycine or a derivative thereof. 5. Treat the solution with 50 g. of "Darco KB". Agitate the slurry at 25° C. for 15 minutes. 6. Remove the carbon by filtering through a precoated diatomaceous earth ("Dicalite") filter. The filtration area is 1.3 cm 2 per g. Lab filtrations used vacuum, were slow and required frequent scraping of the cake surface. Pressure filtration is expected to help this slow rate of filtration. The carbon cake is washed with 1400 ml. of 7:3 propylene glycol:water. Hold this wash separate. 7. Pass the filtrate of Step 6 through a suitable sterile filter into a sterile container. The filtration area is 1.3 cm 2 per g. Wash the filter pad with the wash of Step 6 and again wash with 1000 ml. of sterile propylene glycol - water mixture (7:3). 8. Add 1.75 l of sterile propylene glycol into the sterile solution of Step 7. 9. Under vigorous agitation, slowly adjust the solution of Step 8 to pH 4.1-4.3 with about 300 ml. of sterile TEA over a period of 20 to 30 minutes. 10. Continuously stir the slurry at 25° C. for 4 to 5 hours. The slurry is stable to overnight storage. 11. Filter the sterile crystals and wash the cake with 1000 ml. of sterile propylene glycol - water (7:3) and then 1000 ml. of sterile ethyl acetate. 12. Reslurry the sterile crystals in 2000 ml. of sterile ethyl acetate to remove the excess propylene glycol. 13. Collect the solid by filtration and further wash the cake with 1.2 liters of sterile ethyl acetate - methylene chloride mixture (1:2) 14. Dry the product in 50° C. vacuum oven for 15 hours. The yield is about 820- 910 gm. of crystalline 7-[ D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid 1,2-propylene glycolate. 15. Analyses of Product: Propylene glycol: 1.2- 1.3 moles per mole of 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid by NMR. Pyridine: less than 0.04% by VPC. Bio-assay: 800-850 mcg./mg. NOTES 1. The primary BL-S640 methanolate contains 0.4 to 0.6% pyridine. 2. The white precipitate at Step 4 could be prefiltered through a coarse sintered glass filter with diatomaceous earth ("Dicalite"). The following carbon filtration is easier. 3. If a dark colored 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid methanolate is used, a higher percent carbon treatment may be required. More difficulty is then expected in the filtration. 4. Step 6 and Step 7 should be completed as soon as possible. The sterile filtrate should not be stored longer than 5 hours. If necessary, part of sterile TEA could be added into the filtrate before the washing operation is done. 5. The sterile propylene glycol of Step 8 is sterilized preferably by heating to 80° C. for 30 minutes followed by sterile filtration. Cool to 25° C. before adding into sterile 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid solution. Alternatively, the sterile propylene glycol could be in the receiver of the Step 7 sterile filtration. EXAMPLE 3 Preparation of Sterile Crystalline Parenteral Grade 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid Propylene Glycolate 1. Twenty-five grams of 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid methanolate or recrystallized 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid propylene glycolate is slurried in 150-200 ml. of 75% V/V propylene glycol-water solution at 20°-25° C. 2. Concentrated hydrochloric acid is added to a pH of 1-1.2 to obtain a solution or near solution. 3. Triethylamine (TEA) is slowly added with rapid stirring to obtain a pH of 1.6-1.8. 4. Five grams of "Darco G-60" is added and the mixture is slurried for 0.5 hour. The carbon is removed by filtration (filtration is slow, an 18.5 cm. SS No. 576 paper is suggested). The carbon filter cake is washed with 40 ml. of 75% V/V propylene glycol water solution. The wash is added to the filtrate. 5. Pass the combined filtrate and wash of Step 4 through a sterile 0.22 micron Millipore filter into an appropriate sterile container or tank located in a sterile area. Steps 2, 3, 4 and 5 above should be completed within 6 hours. 6. Sterile triethylamine is added to pH 4.5 over a 10 minute period to the rapidly stirring sterile solution of Step 5. Crystals form in about 1-3 minutes. The mixture is slurried for one hour. 7. The sterile crystals are collected by sterile filtration. Filtration is slow (a 12.5- 15.0 cm. SS No. 604 paper is suggested). The crystals are washed with 50 ml. of sterile 75% propylene glycol, 50 ml. of sterile methanol, 50 ml. of sterile acetone and vacuum dried at 56° C. for 24 hours. Biological yield: 80-95%. 8. The sterile crystals may be sterilely micropulverized to 200 mesh or sterilely micronized. Properties of 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid propylene glycolate a. Bio-assay= 800-860 mcg./mg. b. IR-NMR= Consistent for a structure containing 1.3- 1.5 moles of propylene glycol (17-19% propylene glycol). No loss of the 3-triazole side chain evident. c. % Water, K.F.= 1-3.0. d. Crystal morphology= 100% crystalline Microcrystals, triangular shaped e. M.P.= 182°-184° C. (D, hot stage) f. [α] D 25 (C= 1%; 1N-HCl)= + 53° g. Water solubility= Approximately 10 mg./ml. in water at 23° C. h. Heat stability: 100° C., 24 hours= <6% loss; 100° C., 48 hours= <12% loss; 56° C., 1 month= <10% loss of bioactivity. EXAMPLE 4 Preparation Of Purified BL-S640 Mono-Methanolate 1. One hundred grams of BL-S640 methanolate or 1,2-propylene glycolate is rapidly stirred in 300 ml. of water. 2. Eighty grams of levulinic acid is added. 3. Concentrated hydrochloric acid is slowly added with rapid stirring to pH 0.8- 1.2 to obtain a solution or near solution. The solution is cooled to 20°-25° C. if required. 4. Forty percent sodium hydroxide is added over a five minute period to the very rapidly stirring solution of step (3) to a pH of 4.5 (a precipitate may come down at pH 2.0- 3.0 and then go into solution at pH 4- 4.5). Do not allow the temperature to rise above 27° C. 5. The solution or near solution is cooled to 4°-10° C. and added with very rapid stirring to 500 ml. of 4°-10° C. water. A precipitate forms. 6. The mixture is stirred at 4° - 10° C. for five minutes. The precipitate (X) which contains most of the color and impurities including des-triazole BL-S640 is removed by filtration. The precipitate is washed with 50 ml. of water (do not add the wash water to the filtrate of solid X), 75 ml. of methanol (do not add the methanol to the filtrate of solid X) and vacuum-dried at 50° C. for 25 hours. Yield 5-15 grams of tan-brown solids. (0-500 units/mg.) 7. Fifteen grams of Darco G60 or KB activated carbon is added to the filtrate of precipitate (X), step 6. The mixture is stirred at ambient temperature for 0.5 hours. 8. The carbon is removed by filtration and washed with 40 ml. of water. The water wash is added to the filtrate. 9. The filtrate is sterilely filtered through a 0.22 micron Millipore filter. Steps 4-9 should be completed within four hours. 10. An equal volume (approximately one liter) of sterile, pyrogen-free methanol is added to the pH 4.5 solution of step 9 with moderate stirring. Crystals form in about one minute. Maintain pH at 4.5. 11. The mixture is stirred at 18°-23° C. for one hour. 12. The brilliant white crystals are removed by filtration, washed with 175 ml. of sterile 50% methanol, 300 ml. of sterile methanol and vacuum-dried at 56° C. for 24 hours. Yield: 65-75 grams (bio yield; 70-80%). EXAMPLE 5 Preparation Of BL-S640 Mono-Propylene Glycolate 1. One hundred grams of BL-S640 methanolate or 1,2-propylene glycolate is rapidly stirred in 300 ml. of water. 2. Eighty grams of levulinic acid is added. 3. Concentrated hydrochloric acid is slowly added with rapid stirring to pH 0.8- 1.2 to obtain a solution or near solution. The solution is cooled to 20°-25° C. if required. 4. Forty percent sodium hydroxide is added over a five minute period to the very rapidly stirring solution of step (3) to a pH of 4.5 (a precipitate may come down at pH 2.0- 3.0 and then go into solution at pH 4- 4.5). Do not allow the temperature to rise above 27° C. 5. The solution or near solution is cooled to 4° - 10° C. and added with very rapid stirring to 500 ml. of 4°-10° C. water. A precipitate forms. 6. The mixture is stirred at 5°-10° C. for five minutes. The precipitate (X) which contains most of the color and impurities including des-triazole BL-S640 is removed by filtration. The precipitate is washed with 50 ml. of water (do not add the wash water to the filtrate of solid X), 75 ml. of methanol (do not add the methanol to the filtrate of solid X) and vacuum dried at 50° C. for 25 hours. Yield 5-15 grams of tan-brown solids. (0-500 units/mg.) 7. Fifteen grams of Darco G60 or KB is added to the filtrate of precipitate (X), step 6. The mixture is stirred at ambient temperature for 0.5 hours. 8. The carbon is removed by filtration and washed with 40 ml. of water. The water wash is added to the filtrate. 9. The filtrate is sterilely filtered through a 0.22 micron Millipore filter. Steps 4-9 should be completed within four hours. 10. An equal volume (approximately one liter) of sterile, pyrogen free propylene glycol is added to the pH 4.5 solution of step 9 with moderate stirring. Crystals form in about one minute. Maintain pH at 4.5. 11. The mixture is stirred at 18°-23° C. for one hour. 12. The brilliant white crystals are removed by filtration, washed with 175 ml. of sterile 50% propylene glycol water, 450 ml. of sterile methanol and vacuum dried at 56° C. for 24 hours. 13. Yield 70-80 grams (bio yield 75-85 percent of BL-S640 mono-propylene glycolate. A sample of the mono-propylene glycolate product obtained according to the method of Example 5 was subjected to analysis with the following results: a. Bio-assay= 865 mcg./mg. b. IR-NMR= consistent for a structure containing one mole of propylene glycol per mole of cephalosporin zwitterion. c. % water, K.F.= 0.3. d. Crystal morphology= well-defined rod-like crystals. e. [α] D 23 (C= 1%; 1N-HCl)= + 55.9°. f. % Propylene glycol by chemical analysis= 15.6. g. Other solvents= 0.1%. h. UV absorption spectrum (in 0.1 N HCl) : λ max = 227 nm (a= 28.4) and λ max 272 nm(a= 16.6). A sample of mono-propylene glycolate was examined by x-ray powder diffraction technique using the procedure described below. Results The sample was highly crystalline, yielding 35 measurable diffraction lines. The data in the form of d-spacings and relative itensities are as follows: ______________________________________Line Spacing d (A) Relative Intensity______________________________________ 1 10.11 65 2 9.26 32 3 7.83 18 4 7.33 51 5 6.88 82 6 6.28 56 7 5.71 42 8 5.27 3 9 5.02 4110 4.68 6211 4.46 9912 4.30 5913 4.13 3514 3.91 9015 3.80 10016 3.63 3717 3.47 4918 3.35 1319 3.24 1120 3.13 1421 3.02 1822 2.95 1723 2.85 2524 2.78 5525 2.72 2326 2.61 1827 2.53 2028 2.49 629 2.35 830 2.31 1431 2.27 1432 2.24 1433 2.19 1034 2.14 1435 2.10 15______________________________________ The details for this determination of x-ray diffraction properties are as follows: A small amount of sample was sealed in a 0.2 mm. diameter low scattering glass capillary tube which was mounted for exposure in a 114.6 mm. diameter Debye-Scherrer powder diffraction camera. The exposure time was 4 hours on a Norelco X-ray Generator operated at 35 KV-20 mA using a standard focus copper target X-ray tube (weighted CuK.sub.α wavelength λ - 1.5418 A). Kodak No-Screen X-Ray Film was used and developed for 3 minutes at 20° C. in Kodak Liquid X-ray Developer. A very small amount of crystalline sodium fluoride was mixed in with some samples to provide internal calibration. In addition, a sample of pure NaF was run through the complete procedure for the same purpose. The films were read on a Norelco Debye-Scherrer film reader, recording the positions of the diffraction rings to the nearest 0.05 mm. The data were corrected for film shrinkage and the interplanar spacings (d-spacings) were calculated from the corrected data. A computer program (X-RAY, by P. Zugenmaier) was used for all calculations. The accuracy in the resulting d-spacing data was ˜1%. An intensity record of all films was obtained using a Joyce-Loeble Mark IIIC Recording Microdensitometer (scan ratio 5:1, 0.1 O.D. wedge). Relative intensities on a scale 1-100 were assigned to all recognizable diffraction rings using peak intensities corrected for the background reading. EXAMPLE 6 Preparation Of Purified BL-S640 Mono-Methanolate 1. One hundred grams of pyruvic acid is dissolved in 250-300 ml. of water. 2. One hundred grams of BL-S640 propylene glycolate or BL-S640 methanolate is sprinkled in with rapid stirring over a five minute interval. A pH 2.0 solution or near solution is obtained. 3. The solution is cooled to 10° C. 4. Forty percent sodium hydroxide is added over a five minute period to the very rapidly stirring solution of step (3) to a pH of 4.5 (a precipitate may come down at pH 2.0- 3.0 and then go into solution at pH (4- 4.5). Do not allow the temperature to rise above 27° C. 5. The solution or near solution is cooled to 8°-12° C. and added with very rapid stirring to 500 ml. of 4°-10° C. water. A precipitate forms. 6. The mixture is stirred at 8°-12° C. for three minutes. The precipitate (6X) which contains most of the color and impurities including des-triazole BL-S640 is removed by vacuum filtration. Filtration is slow. Suck the filter cake as dry as possible. Place the filter paper and filter cake in 300 ml. of methanol and hold for four hours. Air dry the filter paper and filtercake, scrape off the solids and vacuum dry at 50° C. for 24 hours. Yield 5-25 grams of tan solids (potency 200-700 units/mg.) Save for reprocessing. 7. Fifteen grams of Darco G60 or KB is added to the filtrate of precipitate (6X) in Step 6. The mixture is stirred at ambient temperature for 0.5 hours. 8. The carbon is removed by filtration and washed with 40 ml. of water. The water wash is added to the filtrate. 9. The filtrate is sterilely filtered through a 0.22 micron Millipore filter. Steps 4-9 should be completed within four hours. The temperature should be below 24° C. for Steps 7-9. 10. An equal volume (approximately one liter) of sterile, pyrogen-free methanol is added to the pH 4.5 solution of Step 9 with moderate stirring. Crystals form in about one minute. Maintain pH at 4.5. 11. The mixture is stirred at 10°-20° C. for one hour. 12. The brillant, white crystals are removed by filtration, washed with 175 ml. of sterile 50% methanol water, 450 ml. of sterile methanol and vacuum-dried at 56° C. for 24 hours. 13. Yield 55-60 grams (bio yield 60-75 percent of crystalline BL-S640 mono-methanolate (Bio-assay 930-960 units/mg. EXAMPLE 7 PREPARATION OF BL-S640 MONO-PROPYLENE GLYCOLATE 1. One hundred grams of pyruvic acid is dissolved in 250-300 ml. of water. 2. One hundred grams of BL-S640 propylene glycolate or BL-S640 methanolate is sprinkled in with rapid stirring over a five minute interval. A pH 2.0 solution or near solution is obtained. 3. The solution is cooled to 10° C. 4. Forty percent sodium hydroxide is added over a five minute period to the very rapidly stirring solution of Step (3) to a pH of 4.5 (a precipitate may come down at pH 2.0- 3.0 and then go into solution at pH 4- 4.5). Do not allow the temperature to rise above 27° C. 5. The solution or near solution is cooled to 8°-12° C. and added with very rapid stirring to 500-600 ml of 8°-12° C. water. A precipitate forms. 6. The mixture is stirred at 8°-12° C. for three minutes. The precipitate (6X), which contains most of the color and impurities, including des-triazole BL-S640 is removed by vacuum filtration. Filtration is slow. Suck the filter cake as dry as possible. Place the filter paper and filter cake in 300 ml. of methanol and hold for four hours. Air dry the filter paper and filtercake, scrape off the solids and vacuum dry at 50° C. for 24 hours. Yield 5-25 grams of tan solids (potency 200-700 units/mg.) Save for reprocessing. 7. Fifteen grams of Darco G60 or KB is added to the filtrate of precipitate (6X) in Step 6. The mixture is stirred at ambient temperature for 0.5 hours. 8. The carbon is removed by filtration and washed with 40 ml. of water. The water wash is added to the filtrate. 9. The filtrate is sterilely filtered through a 0.22 micron Millipore filter. Steps 4-9 should be completed within four hours. The temperature should be below 24° C. for Steps 7-9. 10. An equal volume (approximately one liter) of sterile, pyrogen-free propylene glycol is added to the pH 4.5 solution of Step 9 with moderate stirring. Crystals form in about one minute. Maintain pH at 4.5. 11. The mixture is stirred at 10°-20° C. for one hour. 12. The brillant, white crystals are removed by filtration, washed with 175 ml. of sterile 50 propylene glycol water, 450 ml. of sterile methanol and vacuum-dried at 56° C. for 24 hours. 13. Yield 55-60 grams (bio yield 60-70 percent of the crystalline BL-S640 mono-propylene glycolate. Example 8__________________________________________________________________________Intramuscular 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid [Herein called BL-S640] Propylene Glycolate(Micronized) (Labelclaim is 250 mg./ml. BL-S640 Activity as BL-S640 Propylene GlycolateFORMULA Per 1 Dose Per 5 Doses Per 10 Doses Per 16 Doses__________________________________________________________________________Sterile, Micronized 7-[D-α-amino-α- *0.250 Gram 1.250 Gram 2.50 Gram 4.00 Gram(p-hydroxyphenyl)acetamido]-3-(1,2,3- of activity of activity of activity of activitytriazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid Propylene GlycolatePropyl Paraben 0.0001 Gram 0.0005 Gram 0.001 Gram 0.0016 GramMethyl Paraben 0.0009 Gram 0.0045 Gram 0.009 Gram 0.0144 GramSodium Chloride (Sterile, 0.002 Gram 0.010 Gram 0.02 Gram 0.032 GramMicropulverized)Tween-80 0.001 Gram 0.005 Gram 0.01 Gram 0.016 GramLecithin 0.002 Gram 0.01 Gram 0.02 Gram 0.032 GramPolyvinylpyrrolidone (Povidone) 0.005 Gram 0.025 Gram 0.05 Gram 0.08 Gram__________________________________________________________________________*Label claim is 250 mg./ml. BL-S640 activity as the propylene glycolate.The amount of BL-S640 propylene glycolate required is calculated asfollows: ##STR4##This weight may also be increased in amount by adding increments based onthe following factors:1) Overbatch required for shelf life (stability).2) Overfill required for vial, syringe and needle holdup. -3) Machinefill variability.__________________________________________________________________________ Intramuscular BL-S640 Propylene Glycolate (Micronized) (Label claim is 250 mg./ml. BL-S640 activity as BL-S640 Propylene Glycolate 1. The BL-S640 propylene glycolate to be used must be sterile, pyrogen free and handled aseptically throughout the processing. 2. The BL-S640 propylene glycolate is sterilely micronized in a sterile micronizer. 3. The sterile micronized BL-S640 propylene glycolate plus the sterile sodium chloride is then loaded into a sterile Patterson Kelly V Blender equipped with an intensification bar adapted for liquid addition. The blender has been rendered sterile by spraying with peracetic acid and exposure to ethylene oxide gas for 16 hours prior to use. Care must be taken, before blender is loaded, so that no condensation of the gases has occurred inside the blender. The condensation may be prevented by obtaining proper atmospheric room temperature. The blender is run for 30 minutes with intensification action to assure initial blending of the material. 4. The lecithin, methyl and propyl parabens, Tween-80 and Povidone are dissolved in a volume of methylene chloride equal to approximately one-fifth (1/5) the weight of BL-S640 propylene glycolate required. 5. Using aseptic conditions, the solution of Step 4 is passed, under positive pressure through a sterile 0.22 micron Millipore filter into an appropriate sterile container located in a sterile area. 6. Using the "liquid addition apparatus" of the blender, add the required volume of sterile, pyrogen-free methylene chloride solution of Step 5 in five equal portions. After each addition of solution the intensification bar is utilized for a maximum of two minutes using 4 "agitation" periods during the fifteen minutes blending period required for each addition of solution. At the termination of each blending period the pressure developed during the blending process must be released (noted on gauge on shell of blender) and vacuum applied to remove the methylene chloride vapors. This must be repeated to assure complete removal of vapors. To aid in the evaporation and removal of vapors heat to 115° F. may be applied to the shell by circulating hot water through the walls. 7. When all the solution has been added and blend properly vacated of vapors the material is dropped from the blender and trayed for drying. The material is placed in covered trays and placed in a hot air atmospheric oven and dried for six hours. The temperature of heated air should not exceed 130° F. After six hours of heating, the heat is turned off and air circulated over the trays for 10 hours to assure complete drying. 8. Repulverize the coated material utilizing the procedure of Step 2 so that the following requirement is met: Retained on a 200 Mesh Screen 0.1% Maximum 9. Collect into sterile containers as a finished bulk product for final disposition. 10. The proper amount of coated BL-S640 propylene glycolate is filled, using aseptic technique, into officially designated size silicone coated vials. EXAMPLE 9 ______________________________________Formula of BL-S640 Propylene Glycolate Capsules(250 mg. BL-S640 Activity per Capsule) Per Capsule______________________________________BL-S640 Propylene Glycolate +0.3148 Gm.Lactose U.S.P. 0.0087 Gm.Magnesium Stearate U.S.P. 0.0015 Gm.Net fill weight per capsule 0.3250 Gm.______________________________________ + These combined weights represent 262.5 mg. of activity which is 5% excess over label claim of 250 mg. activity, based on a potency of 834 mcg./mg. for the composite BL-S640 Propylene Glycolate blend. To calculate the amount of BL-S640 Propylene Glycolate to use apply the following formula: (0.2625× 1000)/834= 0.3148 Gm. of blend to use per capsule Note: each lot of BL-S640 Propylene Glycolate is passed through No. 60 mesh screen prior to blending and mixing with remaining ingredients and filling into No. 1 size capsules. EXAMPLE 10 BL-S640 Propylene Glycolate for I.M. Suspension, 300 mg. Formula ______________________________________ Per Vial______________________________________BL-S640 Propylene Glycolate, + 0.359 Gm.sterile, micronizedSodium Chloride, sterile, 0.0024 Gm.micropulverizedTween 80 0.0012 Gm.Lecithin 0.0024 Gm.Polyvinylpyrrolidone (Povidone) 0.0060 Gm.Blend and fill; Total Weight per 0.3710 Gm.10 ml. Vial______________________________________ + This weight is equivalent to 300 mg. of BL-S640 activity. The addition of 9.7 ml. of water for injection results in a suspension having 300 mg. BL-S640 activity per ml. EXAMPLE 11 BL-S640 Propylene Glycolate for I.M. Suspension, 1.0 Gram Formula ______________________________________ Per Vial______________________________________BL-S640 Propylene Glycolate, + 1.196 Gm.sterile, micronizedSodium Chloride, sterile, 0.008 Gm.micropulverizedTween 80 0.004 Gm.Lecithin 0.008 Gm.Polyvinylpyrrolidone 0.020 Gm.(Povidone)Bled the above to give 1.236 Gm.More of the above blend added forVNS holdup++ 0.349 Gm.Total weight per 5 ml. vial 1.585 Gm.______________________________________ + This weight is equivalent to 1.0 Gram of BL-S640 activity.? ++ VNS refers to the vial, needle and syringe. The addition of 3.7 ml. of water for injection results in a suspension having 250 mg. BL-S640 activity per ml. Stabilities on storage were measured for reconstituted 250 mg./ml. of activity BL-S640 propylene glycolate I.M. suspensions prepared as described above with the following results: ______________________________________ % Loss of Bioactivity at 23° C.______________________________________Time in Days Lot 1 Lot 2______________________________________37 2.0 2.114 2.0 1.121 +8.1 +6.330 1.0 5.342 0.0 +1.160 5.1 4.290 1.0 9.5______________________________________ % Loss of Bioactivity at 4° C.______________________________________Time in Days Lot 1 Lot 2______________________________________30 +1.0 1.145 +1.0 1.160 3.0 2.190 1.0 5.3120180______________________________________ The dry powders are stable for at least 4 months at 56° C. The suspensions exemplified above are improved by the addition of a small amount of a nontoxic, pharmaceutically acceptable polycarboxylic acid, e.g. citric acid. The amount of acid used (which is, of course, added in dry form to the blend of the other solid ingredients) is that which is sufficient to provide a pH in the range of 2.8- 3.5 upon reconstitution; without the added acid the formulations have pH's in the range of 4.4- 5. The improvements consist of better color, that is, less development of undesired color on standing, and also a lower rate of loss of bioactivity on standing. Oral Bioavailability In Beagle Dogs Three beagle dogs (mean weight of 8.2± 0.4 kg.) were administered 200 mesh 7-[D-α-amino-α-(p-hydroxyphenyl)-acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid propylene glycolate (bioassay 820 mcg./mgm.) orally at doses of 30 mg. of activity/kg. in hard gelatin capsules. All doses and concentrations reported herein are in terms of the amphoteric material and were corrected for differences in biopotency. Summarized in Table 1 below are the mean concentrations in plasma of beagle dogs administered 30 mg./kg. doses orally of the 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid propylene glycolate. Approximately 40 % of the dose was excreted in the urine within 8 hours of drug administration. The plasma half-life was about 1.36 hours. Table 1______________________________________ Plasma Concentration (μg/ml ± S.F.) 7-[D-α-amino-Time α-(p-hydroxyphenyl)-3-(1,2,3-triazol-5-ylthiomethyl)-(hours) 3-cephem-4-carboxylic acid propylene glycolate______________________________________0.08 0.04 ± --0.25 0.3 ± 0.10.50 5.9 ± 2.00.75 8.4 ± --1.0 15.8 ± 3.21.5 17.7 ± 2.02.0 18.7 ± 0.93.0 13.7 ± 1.24.0 8.4 ± 1.36.0 3.2 ± 0.48.0 1.6 ± 0.2______________________________________

The antibacterial agent 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid, which is a zwitterion, is both purified and converted to a form highly suitable for use in aqueous suspensions by converting it to the crystalline 7-[D-α-amino-α-(p-hydroxyphenyl)acetamido]-3-(1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid 1,2-propylene glycolate, said propylene glycolate containing 1.0 - 1.6 moles of 1,2-propylene glycol per mole of cephalosporin zwitterion.

BACKGROUND OF THE INVENTION The invention relates to a door assembly which may be used with an inlet opening of a money-custody vault or safe, for example. Conventional door assemblies installed at the inlet/outlet gate of a vault or safe are either of a hinged type in which the door is pivotally mounted along its one lateral edge or of a sliding type in which the door runs parallel to the plane of the inlet opening. In either known type, when the inlet/outlet opening is open, the door is laterally removed from the opening, thereby allowing the internal construction and disposition of the vault or safe to be exposed to the view from the outside to would be burglars or thieves. This leads to the disadvantage of affording opportunities to such burglars in a bank which is frequented by many visitors to study and learn the details of the internal portions of such vault or safe. OBJECTS It is an object of the invention to provide a door assembly in which a door is located in front of an inlet/outlet opening of a safe when the latter is open so as to avoid viewing of the interior of a safe from the outside of a safe which is to be closed by the assembly, thus reducing the chance of visual access to the interior of such safes. It is another object of the invention to provide a door assembly in which a door is constructed to be readily operated with a force of a reduced magnitude. SUMMARY OF INVENTION In accordance with the invention, the door assembly comprises a guide means disposed in an orientation perpendicular to the plane of an opening formed in a wall, a door adapted to be fitted into the opening, and a runner or guide follower on the door for running the door along the guide means. Thus the door is movable in a direction perpendicular to the plane of the opening so as to be fit into or moved out of the opening. A handle is provided on the door, whereby the turning force applied to the handle is transmitted to the runner or guide follower through a transmission mechanism. With the present invention, when the door is moved away from the opening in the wall, it continues to be located forwardly of or in front of the opening, thus preventing a view of the interior of a safe from the exterior thereof. Thus when the door assembly is installed in the access opening of the money-custody vault or safe of a bank, it avoids any chance or opportunity for burglars to view the internal structure of the safe. The transmission of the rotation of the handle to the runner or guide follower through the transmission means enables a door of substantial weight to be moved in a facilitated manner with a minimum of effort. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a portion of an embodiment of the invention. FIG. 2 is a cross section taken along the line B--B' shown in FIG. 1. FIG. 3 is a cross section taken along the line A--A' shown in FIG. 1. FIG. 4 is an elevational section illustrating the door in its open position. FIG. 5 is a partial plan view of the door shown in FIG. 4. FIG. 6 is a cross section similar to FIG. 2 showing a second embodiment of the invention. FIG. 7 is a cross section similar to FIG. 2, but showing a third embodiment of the invention. FIG. 8 is a front view of a fourth embodiment of the invention. FIG. 9 is a cross section taken along the line IX--IX shown in FIG. 8. FIG. 10 is a cross section taken along the line X--X shown in FIG. 8. FIG. 11 is a perspective view of a power transmission mechanism employed with the fourth embodiment. FIG. 12 is a perspective view of another form of power transmission mechanism. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIGS. 1 to 5, there is shown a wall 1 which defines a partition between the interior 2 and the exterior 3 of a money-custody vault or safe. A rectangular opening 4 is formed in the wall 1 which is of a size to permit a free access and/or of personnel into and out of the interior 2. A metal door frame 5 is secured to the top, bottom and both side walls of the opening 4. Buried in a floor 7, there are a pair of channel-shaped rails 8 with their open side facing toward each other. The rails 8 start from a position immediately below the opening 4 and extend to a position forwardly thereof in parallel relationship with each other and in a direction perpendicular to the plane of the wall 1. The groove in which each rail 8 is disposed is of a width which slightly exceeds that of the rail, leaving a certain clearance on the open side of the rail 8. Wheels 10 associated with a door 6 rest on the inner surface of the lower limb of the rails 8. A pair of angled wheel bearings 9 are secured to the bottom surface of the door 6 and extend in a direction perpendicular to the plane thereof. The wheels 10 are mounted on the vertical part of the bearings so as to be rotatable in a vertical plane. It will be noted that the vertical part which supports the wheels is received in the clearance formed adjacent the open side of the channels when the wheels are placed on the lower limb of the rails 8. Wheels 10 can be placed in this manner by introducing them into the space within the rails through a notch suitably formed in the upper limb thereof. The bearings 9 have a length which exceeds the thickness of the door 6, and a pair of wheels 10 are journalled on the opposite ends of each bearing. Thus a total of four wheels permit the door 6 to be moved along the rails 8 and to be self-standing. The surface of the door 6 is provided with a covering of metal material, which is internally filled with a filler such as concrete, for example. All around its four sides, the peripheral surface of the door 6 is stepped to make the door 6 have a close fit with the door frame 5 when the door is in the closed position of the opening 4 formed in the wall 1. A handle 11 projects forwardly from the front surface of the door 6 in the central region thereof. When it is desired to move the door 6 from its closed position shown in FIGS. 2 and 3 in which it closes the opening 4, the handle 11 is grasped and pulled forwardly. When pulled in this manner, the door 6 moves away from the opening 4 in a direction perpendicular to the plane thereof as the wheels 10 roll on the rails 8, thus creating a space between the door 6 and the wall 1, as shown in FIGS. 4 and 5. A space of a small width will be sufficient to permit the access of personnel while a larger space may be required to permit the access of a handcart. When pulling the handle 11, an external force may be applied to the door 6 which tends to cause rotating of the door, such rotation is prevented by the abutment of the wheels 10 against the upper limb of the rails 8. When the opening 4 is to be closed, the door 6 may be pushed toward the opening 4. The wheels 10 roll on the rails 8 to bring the door 6 to its closed position shown in FIGS. 2 and 3. In another embodiment, the rails which help the running of the door may be disposed in the ceiling as shown in FIG. 6. Specifically, the pair of rails 8 are mounted in the ceiling so that they extend forwardly from a position directly above the opening 4, extending parallel to each other in a direction perpendicular to the plane of the wall 1. Again, the rails are disposed so that their open side faces each other. The pair of bearings 9 are secured to the top end of the door 6 and rotatably carry wheels 10 which rest on the rails 8, thus suspending the door 6 in a manner to permit its running along the rails. In all other respects, the arrangement is similar to the previous embodiment. This arrangement is advantageous in that the rails are not buried in the floor, which thus remains flat to permit the transport of articles on a cart while avoiding their vibration. The rails which help the guiding of the door may be disposed in both the ceiling and the floor, as shown in FIG. 7, wheels 10 being rotatably carried by the top and bottom ends of the door. Since the overturn of the door 6 is prevented by the co-action between the upper and lower rails 8 and the complementary upper and lower wheels 10, only two wheels could be used on each end of the door instead of four as hereinbefore described. Such construction is preferred for a large or heavy door. To drive the door, a rotary handle may be rotatably mounted on the front face of the door, and the rotating drive can be transmitted to the wheels through a speed reduction transmission mechanism, examples of which are shown in FIGS. 8 to 12. Referring to FIGS. 8 to 11, a shaft 20 extends through the door 6 in the direction of its thickness at a position toward the right-hand side thereof, as viewed in front elevation, and is rotatably carried by the suitable bearings. A handle 21 is fixedly mounted on the forward end of the shaft 20 which projects from the front face thereof, while a bevel gear 13 is fixedly mounted on the rear end of the shaft 20. A pair of bearings 15, 15 are secured to the rear side of the door 6 adjacent both of the lateral edges thereof, and rotatably carry a shaft 12 in a horizontal plane which is at the same level as the shaft 20. Sprocket wheels 16, 16 are fixedly mounted on the shaft 12 adjacent its opposite ends, and another bevel gear 14 is fixedly mounted on the shaft 12 at a position which enables its meshing engagement with the bevel gear 13. Wheels 10 which are rotatably carried by the bottom of the door 6 are fixedly connected with sprocket wheels 17, 17 of a diameter greater than that of the wheels. Endless chains 18, 18 extend around the sprocket wheel 16, 16 and sprocket wheels 17, 17 which are located below the sprocket wheels 16, 16. Consequently, when the handle 21 is manually turned, the rotation thereof is transmitted to the wheels 10 through shaft 20, gears 13 and 14, shaft 12, sprocket wheels 16, 16, chains 18, 18 and sprocket wheels 17, 17, thus rotatably driving the wheels 10 to run the door 6 either forwardly or rearwardly along the rails 8. It is to be noted that the gears and sprocket wheels are dimensioned so that such a power transmission mechanism constitutes a reduction gear ratio. The majority of the transmission mechanism is received in a recess 19 formed in the lower half of the rear side of the door 6, and is protected by a metal cover plate 22, which also avoids a jamming of part of clothes with the mechanism. In other respects, the arrangement is similar to the embodiments mentioned above in connection with FIGS. 1 to 5. This embodiment facilitates the running of a heavy and large door by a manual operation since the reduction gearing transmits the rotating power of the manual handle to the wheels. FIG. 12 shows an alternative arrangement of a modified transmission having a reduction gearing. In this Figure, a sprocket wheel 30 is fixedly mounted on the rear end of the shaft 20 which is integral with the rotary handle 21. A shaft 33 is located below the sprocket wheel 30 and is rotatably supported by a pair of bearings 34 in a horizontal plane. A sprocket wheel 31 is fixedly mounted on the shaft 33 and located directly below the sprocket wheel 30, with an endless chain 32 extending around both of the sprocket wheels. A pair of sprocket wheels 35 are fixedly mounted on the shaft 33 adjacent its opposite ends, and a pair of endless chains 36 extend around the respective sprocket wheels 35 and sprocket wheels 17 on the running wheels 10. Thus, when the handle 21 is manually turned, its drive is transmitted to the wheels 10 through shaft 20, sprocket wheel 30, chain 32, sprocket wheel 31, shaft 33, sprocket wheels 35, chain 36 and sprocket wheels 17, permitting the door 6 to run either forwardly or rearwardly. Again, the parts are chosen such that the power transmission mechanism thus constructed constitutes a reduction gearing. It will be understood that an electric or hydraulic motor or the like may be used to drive the running wheels. In either instance, the rails may be replaced by rack bars and the wheels by pinions. Alternatively, the rails may also be replaced by threaded rods and the wheels by nuts. Finally, it will be appreciated that the described arrangement may be modified to run the door into the vault from its closed position.

A door assembly including a door associated with a guide which is disposed in an orientation perpendicular to the plane of a door opening formed in a wall, and a guide follower mounted on the door to run along the guide. In one embodiment the guide follower is rotatably driven by the rotation of a handle mounted on the door through a transmission. In another embodiment, the door may be manually pushed or pulled along the guide.

RELATED APPLICATION This application is a division of pending U.S. patent application Ser. No. 11/230,016, filed on Sep. 19, 2005, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The present invention manual dispenser for a note paper roll having a low-tack adhesive strip extending along its length for permitting a user to sever segments from the roll of a length determined by the user. BACKGROUND OF THE INVENTION The “POST-IT” pads of the 3M Company provide individual pieces of paper, each of a predetermined size, having a band of low-tack pressure sensitive adhesive along one edge. The pads are held together by the adhesive and the user simply peels off the pieces of paper, as they are needed. The paper pieces can then be attached to a document by simply pressing them into place. They can also be readily removed, without damaging the document. The 3M Company also has a product which utilizes plastic flags, with semi-transparent low-tack adhesive strips which may be used to removably secure the flags to a document. The flags are stuck to one another and provided in a dispenser which dispenses the flags one at a time. When in place on a document, the document can be read through the semi-transparent adhesive strips. Both of the 3M products discussed above consist of a plurality of stacked individual tape segments. With either type, a separate pad or dispenser is required for each size of note or flag. U.S. Pat. No. 5,370,916 to Olsen teaches a tape dispensing system employing a tape having segments of a predetermined size, with bands of transversely extending low-tack adhesive extending thereacross. In use, the segments are severed from the tape, and the adhesive bands enable the individual segments to be secured in place on a document. Like the 3M pads, this system dispenses a segment of a predetermined size. U.S. Pat. No. 5,904,283 by Maurice S. Kanbar, the inventor herein, discloses a roll of note paper having a low-tack adhesive extending along its center-line on one side, and a dispenser for severing segments from the roll, of a length determined by the user. The dispenser employs a motor driven endless conveyor belt to which the adhesive on the roll is temporarily adhered, whereby movement of the belt functions to draw paper from the roll. SUMMARY OF THE INVENTION An object of the invention is to provide a note paper and dispenser combination which comprises a roll of note paper having a strip of low-tack adhesive extending longitudinally along one side thereof and a dispenser for selectively severing segments of the paper from the roll, in lengths determined by the user. The dispenser includes a housing supporting the roll for rotation as a length of paper is manually drawn therefrom. Still another object of the invention is to provide a dispenser for drawing segments of paper from a note paper roll having a strip of low-tack adhesive on one side thereof, without adhering the strip to the mechanism of the dispenser. These and other objects will become more apparent when viewed in light of the following detailed description and accompanying drawings. DESCRIPTION OF THE DRAWINGS FIG. 1A is a perspective view, illustrating a note paper roll having a strip of low-tack adhesive extending longitudinally thereof, centrally of the roll; FIG. 1B is a perspective view, illustrating a note paper roll having strips of low-tack adhesive applied to the inner surface thereof adjacent both of its longitudinal edges; FIG. 1C is a perspective view, illustrating a note paper roll having a strip of low-tack adhesive applied to its inner surface adjacent one of its longitudinal edges; FIG. 2 is a perspective view of the battery operated note paper dispenser of the present invention; FIG. 3 is a cross-sectional side-elevational view of the dispenser of FIG. 2 ; FIG. 4 is a cross-sectional elevational view of the FIG. 2 dispenser, taken on the plane designated by line 4 - 4 of FIG. 3 ; FIG. 5A is a perspective view of the dispenser of FIG. 2 , with the top thereof removed, illustrating the paper roll of FIG. 1 received in the dispenser, and the direct the paper of the roll through the dispenser, without contact of the strip of low-tack adhesive; FIG. 5B is a perspective view of the dispenser of FIG. 2 , with the top thereof removed, illustrating the paper roll of FIG. 1B received in the dispenser, and the guide to direct the paper of the roll through the dispenser, without contact of the strips of low-tack adhesive; FIG. 6 is a perspective view of the manual dispenser of the present invention, with a paper roll received therein shown in phantom; FIG. 7 is a perspective view of the manual dispenser of FIG. 6 , with a paper roll shown therein in solid lines in the process of being torn to remove a segment of a length determined by the user; FIG. 8A is a perspective view of the manual dispenser of FIG. 6 , with the tearing member thereof shown in phantom; FIG. 8B is a cross-sectional elevational view of the manual dispenser of FIG. 6 , taken on the plane designated by line 8 B- 8 B of FIG. 8A ; FIG. 9A is a cross-sectional side elevational view of the manual dispenser of FIG. 6 , with a paper roll received therein shown in phantom, in the process of having of having a segment of the roll drawn through the dispenser; FIG. 9B is a cross-sectional elevational view similar to FIG. 9B , illustrating a paper roll within the dispenser and the hand of a user in the process of drawing a segment of paper from the roll; FIG. 10 is a perspective view of the channel-shaped note paper cutter of the present invention; FIG. 11 is a cross-sectional elevational view of the note paper cutter, taken on the plane designated by line 11 - 11 of FIG. 10 ; FIG. 12 is a side elevational view of the FIG. 10 cutter, shown in place on a large paper roll; FIG. 13 is a side elevational view of the FIG. 10 cutter, shown in place on a paper roll which has been reduced to a relatively small diameter by virtue of the removal of segments of paper therefrom; and, FIG. 14 is a perspective view of the FIG. 10 cutter, shown in the hands of a user, with a paper in place, in the process of having a segment of paper severed therefrom by tearing the paper against the cutter. DESCRIPTION OF THE PREFERRED EMBODIMENTS The roll of FIG. 1A is designated R 1 and comprises a relatively narrow sheet of paper helically wound upon itself around the core 12 . The core 12 defines the axis 14 of the roll. A centrally disposed strip of pressure sensitive adhesive 16 is adhered to and extends longitudinally over the central portion of the inner surface of the roll R 1 . The adhesive may be of the type used in a “POST-IT” sheet. It comprises an elastometric mask coat which will give a bond of at least moderate strength upon the application of light pressure thereto at room temperature. For purposes of this invention, the adhesive must be of a low-tack composition, so that when applied to a paper page, it adheres lightly and can be detached therefrom without damage to the page. The roll of FIG. 1B is designated R 2 . This roll also comprises a relatively narrow sheet of paper 10 helically rolled upon itself about a core 12 defining an axis 14 . In the case of the roll R 2 , however, longitudinally extending strips of low-tack adhesive 18 , 20 extend over the inside surface of the length of the roll adjacent its longitudinal edges 22 and 24 , respectively. The composition of the strips 18 , 20 corresponds to that of the adhesive 16 . The roll of FIG. 1C is designated R 3 and comprises a relatively narrow strip of paper 10 corresponding to that of the rolls R 1 and R 2 , with a longitudinally extending strip 26 of low-tack adhesive extending along the inside surface thereof adjacent longitudinal edge 24 . Like the rolls R 1 and R 2 , the roll R 3 has a core 12 defining an axis 14 . From a comparison of FIGS. 1A , 1 B and 1 C, it will be seen that the paper rolls therein differ only in the placement of the adhesive strips provided on the inside surface of the paper of the roll. As the result of the difference in the manner in which the strips are placed, segments of paper removed from the rolls adhere to mating papers in different way. In the case of the roll R 1 , a segment would be secured to a mating paper continuously along the center line of the segment. In the case the roll R 2 , a segment would be secured to a paper along both of the longitudinal edges of the segment. In the case of the roll R 3 , a segment would be secured to a paper along only one edge, much in the same way as a conventional POST-IT pad segment. Battery Operated Dispenser The battery operated dispenser shown in FIGS. 2 to 5B is designated, in its entirety, by the letters BD. It comprises a shell like housing 28 having lower and upper portions 30 and 32 , respectively. The housing may be fabricated of any suitable material, such as a polymer plastic, or sheet metal. The upper portion includes a forward section 34 with a slot 36 extending therethrough for passage of the leading end 38 of a paper roll received within the housing. The paper roll shown in FIGS. 2 to 5A is the roll R 1 of FIG. 1A . The rearward section, designated 40 , of the upper portion is removable to permit a roll to be inserted into the dispenser. When inserted, the roll rests on the bottom wall of the lower portion 30 and is free to rotate about its axis. Interiorally, the forward section 34 of the housing is provided with fixed webs 42 (see FIG. 5A ) to support the axle 44 for traction wheels 46 and 48 . Slots 50 formed in the webs 42 are proportioned to slidably receive and rotatably support the axle 44 and provide means whereby the assembly of the axle and the traction wheels thereon may be moved vertically into place. A pedestal 52 within the forward section 34 of the housing supports a small battery operated electric motor 54 having a shaft 56 which rotatably drives a sheave 58 having a belt groove therearound. A band 55 secures the motor to the pedestal. The traction wheel 46 has a sheave groove formed therearound in alignment with the groove of the sheave 58 . A pair of closed looped rubber belts are engaged around the sheave 58 and the sheave provided by the grooves in the traction wheel 46 , whereby the motor rotatably drives the traction wheel 46 . The outer surfaces of the belts 60 extend radially outwardly from the traction wheel 46 to provide a traction surface for engagement with the underside of the leading end 38 of the paper roll (see FIG. 3 ). The axle 44 is fixed or keyed to the traction wheels 46 and 48 , whereby rotation of the wheel 46 is imparted to the wheel 48 . The peripheral surface of the traction wheel 48 is formed with an annular groove which carries rubber traction tires 62 extending radially from the traction wheel 48 . These tires have an outside diameter corresponding to the outside diameter of that portion of the traction wheel 46 defined by the outer surfaces of the belts 60 (see FIG. 4 ). Thus, the tires 62 of the traction wheel 48 are disposed for driving engagement with the underside of the leading end 38 of the roll being dispensed. (See FIGS. 3 and 4 .) Batteries 64 for powering the motor 54 are mounted in the forward section of the housing 28 (see FIG. 3 ). A suitable access opening (not illustrated) is provided in the bottom of the housing in order that the batteries may be replaced, when necessary. The control circuitry for the motor 54 is diagrammatically illustrated in FIG. 4 . A lead 66 connects one pole of the battery 64 to the motor 54 and the lead 68 connects the other pole of the battery to a switch plate 70 extending across the top of the housing. The lead 72 is connected between the motor 52 and the switch plate 70 , whereby, upon activation, the switch plate serves to complete the circuit between the battery 64 and the motor 54 , to drive the motor. The switch plate is activated by depressing a button 74 engaged with an extending slidably through the upper surface of the forward housing 34 . A guide member 76 is supported between pedestals 78 within the housing, and the rearward upper edges of the webs 42 . The purpose of the guide member is to guide the leading end of the roll being dispensed through the slot 36 . Upperwardly ending lateral edge surfaces 80 on the guide member are disposed to engage the edges of the sheet of paper being dispensed. The bottom of the guide member includes lateral side surfaces 82 for engagement with the underside of a sheet being dispensed and a downwardly extending channel portion 84 of a width slightly greater than that of the strip of adhesive 16 on the paper. The channel portion assures that the adhesive will not contact the guide, thus enabling the leading end of the roll being dispensed to pass through the dispenser, without adhering to the guide member and hanging up. FIG. 5B shows a modified guide member 86 for use in dispensing paper segments from rolls having adhesive strips along their lateral edges, as seen in the rolls R 2 and R 3 of FIGS. 1B and 1C . The guide member 86 has edge surfaces 88 for engagement with the lateral edges of the roll and a central surface 90 for sliding engagement with the underside of the roll being dispensed, between the strips of adhesive. Channel portions 92 extend across the guide member in alignment with the adhesive strip or strips adjacent the lateral edges of the underside of the roll. The channel portions 92 , like the channel portion 84 , enable paper to be dispensed, without the adhesive strips adhering to and hanging up on the guide. The operation of the dispenser BD is illustrated in FIGS. 1 and 2 . As there shown, the leading end 38 of the roll being dispensed is directed over the guide member 76 and the traction wheels 46 and 48 , and through the slot 36 . An under-surface 94 carried by the housing engages the top surface of the paper in apposition to the traction wheels. As so disposed, the leading end 38 of the paper roll is captured between the under-surface 94 and the outer surfaces of the belts and tires received on the traction wheels. Thus, rotation of the traction wheels clockwise, as viewed in FIG. 56 , functions to move the leading edge 38 through the slot 36 . In use, the length of a segment of paper dispensed by the dispenser BD is controlled through the switch button 74 . All that the user needs do is to depress the switch 74 to activate the motor 54 so as to move a segment of the leading end 38 through the slot 36 . The length of this segment is determined by the user, through means of the button. Once a segment of the desired length extends from the dispenser, it may be removed by simply tearing the segment against upper edge of the groove 36 , as seen in FIG. 2 . Manual Dispenser This dispenser, as illustrated in FIGS. 6 to 9B , is designated in its entirety by the legend MD. It comprises a housing 96 which may be fabricated of a polymer plastic, or any other suitable material. The housing is upperwardly open and has sidewalls 98 , 100 , a bottom wall 102 , a rear wall 104 and a front wall 106 . Arcuate webs 108 are secured to and extend rearwardly from the front wall 106 . These webs, together with the interior surfaces of the walls 98 , 100 , 102 and 104 , define a cavity for rotatably receiving a roll of paper, as may be seen from FIGS. 9A and 9B . The front wall is arcuately concave, as viewed in plan (see FIG. 8A ). A guide member 110 is secured between the side walls 98 , 100 extends over and in slightly spaced relationship to the front wall 106 . This guide member provides a slot 112 through which the leading end of a roll of paper being dispensed may be directed. The rearward edge of the guide member, designated 114 , is curved upwardly to facilitate directing paper through the slot, with a minimum of friction. The forward end of the guide member is formed with a sharp tear edge 116 . Friction means, in the form of fingers 118 are fixed to and extend forwardly of the front wall 116 in converging relation to the inner surface of the guide member 110 . At their distal ends, these fingers barely contact the inner surface of the guide member. In use, a roll of paper, which may be of the type of any of the rolls R 1 , R 2 or R 3 , is received within the housing, as seen in FIGS. 9A and 9B , and its leading end 38 is directed through the slot 112 (see FIGS. 9A and 9B ). The user may than manually draw a segment of the paper of any desired length from the roll, and sever it by tearing the paper against the under surface of the tear edge 116 (see FIG. 7 ). The fingers 118 hold the remaining leading end of the paper within the slot. The user may remove successive segments of paper, of a length which he or she determines, by simply reaching under the guide member 110 between the fingers 118 and pulling the paper through the slot. The fingers are positioned so as not to engage the adhesive strips on the paper roll, whether these strips be located centrally of the paper, or adjacent its lateral edges. The webs 108 are similarly positioned and so proportioned to avoid such contact. The narrow upper edge of the front wall 106 also minimizes any adhesion between the adhesive strips and the housing. Manual Cutter This cutter is shown in FIGS. 10 to 14 and designated, in its entirety, by the legend MC. The cutter may be fabricated of a polymer plastic or any other suitable material. It comprises a generally channel shaped housing 120 of a width slightly greater than that of the roll. (The housing may be fabricated of telescoping channel shaped members, so that its length may be adjusted to accommodate rolls of different widths.) The housing 120 has a top wall 122 , side walls 124 extending downwardly from the top wall to distal edges 126 , end walls 128 , 130 , and an interior protuberance in the form of a web 132 . In use, a leading end 38 of a roll is partially withdrawn therefrom and the manual cutter is placed over the roll, as shown in FIGS. 12 and 14 . The leading end is then drawn from the roll to provide a segment of paper of a length determined by the user. The user then tears the segment against an edge 126 of the cutter, as shown in FIG. 14 . While the roll shown in FIGS. 12 and 14 is designated R 1 , the cutter may be similarly used with the rolls R 2 and R 3 . The protuberance provided by the web 132 is for purposes of accommodating a roll of a relatively small diameter, as naturally occurs due to the decrease of the roll diameter in use. Its function is shown in FIG. 13 wherein a relatively small roll is shown engaged by the web and one of the edges 126 . As so disposed, segments of paper of a size determined by the user may be removed, similar to what is seen in FIG. 14 . The hand or hands of a user of the various embodiments of the invention are designated by the legend H. Whether one or two hands is used will depend upon the preference of the user. Typically, with the battery operated dispenser, one hand would be used to control the button 74 and to tear the paper. CONCLUSION From the foregoing description, it is believed apparent that the present invention enables the attainment of the objects initially set forth herein. In particular, it provides rolls of paper with low-tack adhesive strips applied thereto wherein segments of the paper of a length determined by the user may be created from a continuous paper roll. It should be understood, however, that the invention is not intended to be limited to the specifics of the embodiments which have been illustrated and described, but rather as defined by the accompanying claims.

A manual dispenser for severing a segment of paper from a note paper roll comprised of a narrow elongate sheet of paper helically wound upon itself, with one surface of the sheet having one or more strips of low-tack pressure adhesive extending longitudinally thereof. In one embodiment, the manual dispenser includes a tear bar that that is manually engagable with one side of the roll.