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Effect of Cr Dopant on High-Temperature Embrittlement in Fe Alloys Containing High Concentration of Cu
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To evaluate usage of ferrous scraps containing a high concentration of Cu, the mechanical properties of Fe–Cu alloys with 0.3∼4.0 mass% Cu were examined focusing on the effect of the Cu-rich phase segregated at grain boundaries on high-temperature embrittlement; ductility improvement was attempted by adding a small amount of Cr. Excess Cu atoms in the Fe–Cu alloys segregated and formed Cu-rich phase at the grain boundary in α matrix depending on the grain boundary character. Large Cu-rich phase was susceptible to nucleation of microcracks and induced grain boundary fracture, resulting in a loss of ductility at high temperature. Addition of a small amount of Cr effectively improved ductility of α Fe–Cu alloys at high temperature because the formation of Cu-rich phase was suppressed by Cr addition and/or segregated Cr increased the bonding force at grain boundaries. Ductility decreased in γ Fe–Cu alloys with increasing Cu concentration and this reduction was not improved by Cr addition. High strength Fe–Cu alloys containing a large quantity of Cu was obtained, however, by Cr addition.
- Transactions of the Iron and Steel Institute of Japan
Transactions of the Iron and Steel Institute of Japan 38(8), 888-895, 1998-08-15
The Iron and Steel Institute of Japan | Yes |
The influence of roots and leaf extracts of Jasminum grandiflorum was studied for its wound healing activity using the excision wound model. The roots and leaves of Jasminum grandiflorum were extracted with alcohol 90%, were subjected to phytochemical investigation. The root and leaf extracts were screened for wound healing activity. The animals were divided into four groups in excision wound mode...
EXTRACTION, PURIFICATION AND DETERMINATION OF PHYTO-COMPONENT OF FATTY ACIDS FROM IRVINGIA GABONENSIS SEEDS
Objective: This study was designed to extract, purify and determine the phyto-components in the petroleum ether extract of Irvingia gabonensis seeds (IGS). A multiple batch extraction procedure was employed using petroleum ether as a solvent. A specified quantity of the IGS was size reduced, dispersed in freshly distilled water by heating to a temperature of 80 ºC. The dispersion was then filtere...
EVALUATION OF ANTIMICROBIAL ACTIVITY OF THE STEM BARK OF MAESOBOTRYA DUSENII (PAX) HUTCHINSON (EUPHORBIACEAE)
Introduction: Infection due to antimicrobial resistance is currently one of the major threats to mankind. This study investigates the antimicrobial activity of the various extracts of the stem bark of Maesobotrya dusenii (Pax) Hutchinson (Euphorbiaceae). Methods: Pulverized 100 g of stem bark of M. dusenii extracted with methanol. Another 400 g of the plant material was also successively macerated...
Infectious diseases are one of the major problems in the world. After the discovery of penicillin, many classes of the antimicrobial agent were introduced and most infectious diseases were brought under control. However, the increased use of these antimicrobial agents in clinical practice was soon followed by the emergence of antibiotic resistance. Because of multiple drug resistance and adverse e...
Treatment based on traditional medicine is very popular in the developing world due to inexpensive properties. There is a growing interest in herbal medicine. Curcumin a hydrophobic poly-phenol is derived from turmeric, the rhizome of the herb Curcuma longa L. Neurodegenerative diseases have become a major challenge for public health because of their incurable status. Curcumin has an outstanding s...
SYNTHESIS, CHARACTERIZATION, ANTIOXIDANT AND ANTI-INFLAMMATORY ACTIVITY EVALUATION OF SOME SUBSTITUTED PYRAZOLE DERIVATIVES
A series of substituted acetophenones are condensed with hydrazides to the corresponding hydrazones which are subsequently cyclized by using volumizer-Haack reaction to give new pyrazole derivatives. All the compounds 4a, 4b, 4c, 4d, 4e were screened for antioxidant, anti-inflammatory activity. Few of the compounds showing good antioxidant and anti-inflammatory activity....
Hyperlipidaemia (Adhi dhoola noi) is a well known metabolic disorder, prevalent in 30-40% of the people worldwide. It is one of the most important factors of morbidity and mortality related to atherosclerotic cardiovascular disease and diabetes. Research articles prove hyperlipidaemia as an important factor that determines the risk of atherosclerotic heart disease and endocrinal disorders. Siddha ...
PHYTOCHEMICAL SCREENING ASSESSMENT, ANTIOXIDANT CAPACITY AND ANTIMICROBIAL SUSCEPTIBILITY OF EXTRACTS FROM CECROPIA PACHYSTACHYA TRÉCUL. CECROPIACEAE (URTICACEAE) AS SOURCE FOR HERBAL MEDICINES DEVELOPMENT
Several plants used for medicinal purposes can be found in the Brazilian Cerrado, among which highlights the genus Cecropia used as a bronchodilator, antitussive, anti-diabetic, anti-diarrheal, anti-hypertensive, anti-inflammatory and vasorelaxant. Between species, there is Cecropia pachystachya belongs to the Urticaceae family. This study aims to evaluate the phytochemical screening, antioxidant ...
BIOLOGICAL ACTIVITIES OF EXTRACTS AND SEASONAL VARIATION IN ESSENTIAL OIL COMPOSITION FROM MYRCIARIA GLAZIOVIANA (MYRTACEAE)
Extracts from leaves, stems and flower buds of Myrciaria glazioviana were analyzed for their antioxidant and anticholinesterase activity. The methanolic extracts showed the best results in reducing power (623.52 - 806.15 mg AA/g of extract), DPPH radical scavenging (IC50 = 9.77 - 14.06µg/mL) and lipid peroxidation inhibition activity (21.30 - 66.80 %). These data were correlated to the total phen...
Lantana indica Roxb. (Verbenaceae) is grown as an ornamental plant in tropical and subtropical regions of the world. The plant is used to treat asthma, abdominal disorders, bilious fever, cancer, catarrhal infections, chicken pox, eczema, hypertension, malaria, measles, swelling, rheumatism, tetanus, and ulcers. Phytochemical investigation of a methanolic extract of the leaves led to isolating thr... | Yes |
Oil refiner Motor Oil Hellas, Titan Cement, also from Greece, and Holcim’s subsidiary in Croatia are among 41 companies in the European Union selected for a total of EUR 3.6 billion in grants from the Innovation Fund. All three were competing with their carbon capture projects.
Southeastern European companies are slowly emerging in the decarbonization arena in Europe. Fossil fuel producers and refiners are tapping on subsidies with the aim to position themselves in the future market while the cement sector, which is faced with some of the greatest challenges on the road to climate neutrality, is catching on.
One of the ways, at least in theory, is to sequester carbon dioxide emissions from production and store the greenhouse gas permanently. The European Commission supports the development of carbon capture and storage or CCS technology, which is yet to prove its reliability. Variations include the utilization of some or all of the CO2 for industrial purposes, hence the U in the other acronym, CCUS.
Another two major cement producers are entering the CCS arena in Southeastern Europe
The EU’s executive body has just announced 41 winners from the third call for large-scale clean technology projects that competed for massive grants from the Innovation Fund: EUR 3.6 billion in total. A total of 239 proposals were submitted. Among them are three firms operating in the Balkans.
They all participated with carbon capture projects, in the general category. The remaining segments were industry electrification and hydrogen, clean tech manufacturing, and mid-sized pilots. The winners are obligated to complete a grant agreement preparation process.
Motor Oil to produce e-fuel from hydrogen, captured CO2
Motor Oil Hellas, based in Greece, said it won a whopping EUR 127 million for a project called IRIS – Innovative low caRbon hydrogen and methanol productIon by large Scale carbon capture. The company intends to sequester carbon dioxide from the emissions at its future blue hydrogen production unit in one of its oil refineries.
It revealed that the idea is to make methanol from natural gas for e-fuel. The fossil fuel firm would also use green hydrogen in the process. It is obtained through electrolysis powered by renewable sources. The company would produce 56,000 tons of blue hydrogen per year.
Motor Oil also has a green hydrogen joint venture with Public Power Corp. (PPC) called Hellenic Hydrogen.
Titan Cement is preparing carbon capture, storage system
Titan Cement is another Greek company on the list. IFESTOS is one of the largest carbon capture projects in Europe. The firm plans to produce zero carbon cement and concrete. Furthermore, it intends to create decarbonization synergies with regional industries, the documentation shows.
It would retrofit cement kilns in its Kamari plant near Athens in combination with first- and second-generation Oxyfuel and post-combustion cryogenic capture technologies. The project is expected to avoid 98.5% of the plant’s greenhouse gas emissions.
The project is intended to be connected to transportation and storage infrastructure. Captured CO2 would be liquified and transported to a permanent storage site in the Mediterranean. Titan said it signed memorandums of understanding with potential partners.
The company plans to produce three million tons of zero carbon cement per year at the site.
Holcim developing CCS chain in Croatia to decarbonize its clinker production
The third beneficiary based in Southeastern Europe is Holcim’s subsidiary in Croatia. The project is called KOdeCO net zero.
The cement producer aims to create the first-of-its-kind end-to-end CCS chain in the country. The CO2 captured in its plant in Koromačno is planned to be directed to the first permanent offshore geological storage in the Mediterranean Sea, the European Commission said.
It would be a large-scale industrial demonstrator of Cryocap technology. The facility is set to capture clinker production flue gas at the top of the preheater. The innovative solution would allow electricity savings of 20%. In addition to circularity of condensate and reduced water consumption, it is envisaged to enable net zero cement production by 2028.
KOdeCO stands for Koromačno-decarbonization-ecology. The company said the project is worth EUR 237 million.
Holcim’s carbon capture endeavor in Belgium and an e-methanol investment in France also won support from the Innovation Fund. The cement giant noted it previously got backing for CCUS projects in Germany and Poland. | Yes |
What is xenon? It’s not something that common people encounter on a daily basis. This could be the first time that you’ve heard of it. If you’ve heard it before, you didn’t really mind it.
Nowadays though, you can benefit from knowing what it is, its uses and more. This is because it’s actually found in a lot of things that we use. This is why we encourage you to keep on reading so you’ll know everything there is to know about it.
What is Xenon?
It’s actually a chemical element. It’s found in the atmosphere of our planet in small amounts. It’s derived from a Greek word that translates to “stranger”. Morris Travers and William Ramsay made the discovery in 1898. It carries the symbol Xe and has the atomic number 54 meaning its nucleus has 54 protons. Just like the other in its group, it’s in Group 18. Xenon is in Period 5.
It belongs to a group of chemical elements that share these properties – dense, colorless and odorless. Members of this group are neon, helium, krypton and argon. This group is inert or un-reactive. Although, xenon is not completely un-reactive. This was proven by Neil Bartlett in 1962 when he was able to form a compound that consists of platinum, fluoride and xenon.
Where is Xenon Found?
As mentioned, it’s found in the atmosphere. One part can be found in 20 million, making it a very rare element. It’s also found in the atmosphere of planet Mars.
You’re probably thinking that it’s impossible to extract it because it’s in the atmosphere in small amounts. It’s also found here in the planet with some mineral springs emitting it. There are also industrial plants that harvest the gas from liquid air. This is usually how companies extract it to be used commercially.
There’s also the possibility that it can be found inside the Earth’s core. It’s just suspicion at this point. Scientists are basing this suspicion on what they know about other noble gases. The environment of the Earth’s core is causing xenon to make a bond with nickel and iron. This is why they believe that it’s stored there.
Scientists are hoping to confirm their suspicions soon.
Here are the xenon properties that you have to know:
- It’s a noble gas.
This simply means that it belongs to a group of elements that doesn’t react with other elements because they’re way above them. Noble gases are also called inert gases and as such, they don’t naturally react with other elements.
As mentioned, xenon is not totally inert. Neil Bartlett was able to make xenon platinofluoride. This led to other chemists to making other compounds.
- It’s very rare.
This colorless and odorless gas is considered to be a trace gas in the atmosphere. It occurs at a very rare 1 part in 20 million. It can be produced commercially. Plants around the world can only produce less than a ton each year, though.
- It’s more or less 4 times denser than air.
Air has a density of 1.29 grams per liter. On the other hand, xenon has a density of 5.8971 grams per liter.
- It has a melting point of – 112 °C.
Gas doesn’t technically melt. In this case, it means that this is the temperature wherein xenon, in its liquid form, turns solid.
- It has a boiling point of – 107 °C.
Being a gas, it doesn’t technically boil. This means that this is the temperature wherein xenon gas turns liquid.
- It’s generally harmless.
It’s an atmospheric gas so it’s considered to be harmless. However, some of its compounds can be toxic and even fatal. This is especially true if compounded with oxygen. It can even explode.
Here are some additional xenon facts:
- It came from the Greek word xenos which means stranger.
- Its discoverers, William Ramsay and Morris Travers, also discovered neon and krypton.
- It was discovered when the discoverers evaporated liquid air and studied its remains.
- While considered to be unreactive, it can actually be reactive with fluorine when high pressure and/or temperature are applied.
- It follows the octet rule which is why it’s generally unreactive. This means that you’d need an immense amount of energy (1172 kJ/mol) to take out electron from xenon. To take out a second electron, 2046.4 kJ/mo of energy is required.
- Pure xenon, considered to be the most stable, oxidizes at 0. Otherwise, it oxides at +1, +2, +4, +6 and +8.
- As far as isotopes are concerned, there are 8 stable and 30 unstable. Only tin has more stable isotopes with 10.
- While considered a trace gas in the atmosphere of Earth and Mars, there is a massive amount of it in Jupiter.
- It can be turned metallic by applying a high amount of pressure. In this state, it can turn sky blue in color.
What is Xenon Used for?
It’s popularly used in lamps. This is because a glow of blue is emitted when you apply electricity to it. Think of how neon lights work.
These lamps are not just for show. They are also utilized to disinfect the room and clear it of bacteria. This is why they’re used in hospitals including hospital equipment. This is also the reason why these lamps are used in the food industry.
As lamps, xenon is also applied to photography as electronic flash bulbs that are characterized by their high speeds. They’re also used in ruby lasers.
Xenon also plays an important role in satellites. Xenon ion is used in systems that propel satellites and similar spacecraft to keep them from falling. In fact, NASA has a Xenon Ion Drive engine that propels them at speeds of up to 146,000 kilometers per hour.
Xenon vs LED vs Halogen
This is a common conversation among car owners because they want to find the best headlight for them and they generally have these 3 choices:
This comes in the form of xenon HID (High Intensity Discharge). It’s fast becoming standard issue on higher-end models because it gives a first-class appearance.
This works by using electrodes in charging the bulb’s gas. This process produces the bright white light.
LED highlights are characterized by their extremely white light. This light is produced by utilizing negative electrons in order to produce protons. This occurs thousands of times a second. While a relatively new player, it should be a popular choice soon because of its efficiency.
This type is what you usually find on the road. It’s a favorite of manufacturers because it’s very easy and affordable to produce. It’s also very easy to replace halogen bulbs which is appreciated by vehicle owners.
There is a filament inside the bulb. Together with halogen gas, there’s tungsten in the filament that heats up when electricity reaches it. This results to the glow.
Here are the important things to consider for you to make your choice:
- Color temperature
It’s basically a tie between xenon HID and LED with a color temperature estimated at anywhere from 4000k and 6000k. Halogen trails behind at just between 3200k and 5000k.
LED stands out with an estimated life of 5,000 hours. Xenon HID comes in at second at 2,500 hours. On the other hand, halogen is at a paltry 200 to 400 hours.
- Ease of installation
This is where halogen stands out. It’s very easy to install. Most vehicle owners can just slot it at its place. On the other hand, you need an automotive electrician to install the other two.
If you ever want to have outdoor lighting installed, make sure to get quotes for it through our website. You can also easily get quotes from electricians and construction contractors for whatever your project is, even for things that involve installing xenon lights in your home. | Yes |
Automated Parallel Derivatization Strategy with Broad Metabolite Coverage Coupled to SWATH/MS Data Acquisition for Qualitative and Quantitative Analysis
Diversity in metabolite polarity and electrospray ionization efficiency challenge the development of a single method. Chemical derivatization can significantly improve chromatographic retention time and MS response. We propose a workflow including an automated fast parallel derivatization of amines, phenols, aldehydes, alcohols and ketones followed by QUAL/QUANT SWATH/MS analysis for broad metabolite coverage.
Dansyl-chloride (DanCl), dansyl-hydrazine (Dan-N2H3) and their 13C label analogs were used as derivatization agents. Samples (49 analyte mix and urine) were derivatized with 12C reagents while standards were derivatized with 13C labeled regents using PAL RTC autosampler (CTC Analytics). The two fractions were mixed and injected onto a column-swtiching LC system. MS acquisition was performed on a TTOF6600 (Sciex) using SWATH acquisition.
Polar metabolites are converted to more hydrophobic products (DanCl and Dan-N2H3 derivatives), enabling them to be separated on reverse phase liquid chromatography. The presence of a basic p-amino group on both reagents increase the electrospray response factor by a factor of 10 to 200. Primary alcohols, phenols, primary and secondary amines are derivatized with DanCl and Dan-N2H3 transforms ketones and aldehydes to hydrazones. The automated parallel derivatization enables reproducible derivatizations in a single workflow including light labeling of sample and heavy 13C labeling of metabolite mix in 15 minutes during the LC analysis of the previous sample. Collision induced dissociation generates fragments specific for the analyte, and for the light and heavy derivatized analytes and for tags (XIC m/z=171 and m/z=173). LC-SWATH/MS which collects all precursors and all fragments allowed the screening and the relative and absolute quantification (n=45) of metabolites in urine.
Labelled reagents enable to generate adequate standards for amines, phenols, aldehydes, alcohols and ketones. Automation was found to be key for reproduciblility and is performed on-line prior LC analysis. In a batch, sample preparation and sample analysis are overlaid resulting in a significant gain of time. Dansyl-chloride and dansyl-hydrazine were found to be ideal for light/heavy labeling, improved LC retention, improved MS response and MS/MS tag. | Yes |
Action: Reduces redness,
Gives skin glow
Moisturises and rejuvenates skin
Restores the skin’s natural pH of 5.5.
Fresh looking skin
Smooth and Firm skin
Radiant and healthy looking skin
Ingredients: Low molecular weight Hyaluronic Acid – the newest, most effective form of strong moisturising componenth, whose molecules have the ability to penetrate into the deep layers of the skin.
As a result, the skin is intensely moisturised from the inside – is clearly smoother, firmer and more elastic.
Vitamin B5 moisturises and soothes the skin, helps the healing process of its micro-injuries.
Lactic Acid highly moisturises, normalizes the processes of exfoliation. | Yes |
Chromium processing:, Chromium (Cr) is a brilliant, hard,, and silica in the ore and the use of silica as a flux to lower the melting point of the slag. Get More Info; NiChrome Nickel Chromium Alloys
Oct 03, 2013· Making Fused Silica Making fused silica has been one of my goals for awhile, impractical as it may be. The major hangup for me has been finding a proper source of sand .
A melting point apparatus is a scientific instrument used to determine the melting point of a substance. Some types of melting point apparatuses include the Thiele tube, FisherJohns apparatus, Gallenkamp (Electronic) melting point apparatus and automatic melting point apparatus.
Selfcontained breathing apparatus (EN 133) SECTION 6. ACCIDENTAL RELEASE MEASURES ... Soak up with inert absorbent material ( sand, silica gel, acid binder, universal binder, sawdust). Shovel into suitable container for disposal. ... SAFETY DATA SHEET.
Silica Sand is not flammable, combustible or explosive. It does not cause burns or severe ... and fit test respirators in accordance with OSHA regulations. Maintain and test ... Melting Point: 3110 F Evaporation Rate None SECTION 10: STABILITY REACTIVITY Stability: Crystalline silica (quartz) is .
Arizona Test Dust (ATD) Further trade names Arizona sand including Arizona Test Dust, Arizona Road Dust, Arizona Silica, AC Fine and AC Coarse Test Dusts, SAE Fine and Coarse Test Dusts, J726 Test Dusts, ISO 121031, A1 Ultrafine Test Dust, ISO 121031, A2 Fine Test Dust, ISO 121031, A3 Medium Test Dust and ISO 121031, A4 Coarse
* Absorb or cover with dry earth, sand or other noncombustible material and transfer to containers. ... Boiling Point >300 F Melting Point No data available ... Flash Point 245 F (118 C) Flash Point Test Type CC (Closed Cup)
Ohio EPA air pollution regulations require crushed stone/sand gravel plant enclosures on crushers and screens, chemical dust suppressants or oil on... Get Price Online. ... Apparatus Test Melting Point Sand Silica; Disadvantages Of Crusher Machine; Gold Crusher Machine Price;
apparatus test melting point sand silica; pro premium versus arkansas test stone; sample of aggregate impact value test bs; ball mill axial test procedure; SOlutions Get Price. ratio of crusher run 99+ customer review .
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Silica Sand Processing Equipment Alibaba. Silica sand crusher in Russia, silica sand processing equipment for sale .... China 2016 Ore Testing Equipment Mining Machine Silica Sand Vibrating Screen.
Test: Determination of stick point of Resin coated sand Application: The Stick Point Tester is used to determine the Stick point of thermo setting mixture of the Sand and Synthetic Resin or Resin coated silica sand (shell moulding sand).
SILICA (CRYSTALLINE, RESPIRABLE) (silicon dioxide, quartz, tridymite, cristobalite) ... Melting point 1610 °C Boiling point 2230 °C ( °K) ... a function of the apparatus used and the rate of airflow through the apparatus. Quartz dust was
Silica Sand Market: Global Industry Trends, Share, Size, Growth, Opportunity and Forecast Silica sand, also known as industrial sand, is one of the most common varieties of sand . Global Silica Sand Market Research Report and Outlook . According to the report the global silica sand market has grown at a CAGR of around 6% during .
Detroit Cup Test. A cupping test for sand, using a steel ball as plunger, the depth of cup being shown on a dial. DeVries Test. A test to give the relative hardness of deep hardening steels. See BHN, Brinell Hardness. Dew Point. The temperature at which moist air will become saturated and condensation of water vapor will take place. Dewaxing
Melting point 1. What two effects do impurities have on the melting point of an organic compound? Soluble impurities affect the melting point of a solid in the following manner. a. The presence of an impurity in the molten compound reduces its vapor pressure thus lowering the melting point of the compound. b. Broaden the melting point range.
We offer Silica Crucible. Low form, glazed inside and outside, translucent, with lid. Low form, glazed inside and outside, translucent, with lid. The high purity quartz crucible is the key necessaries in pulling monocrystalline silicon, which is made of the high purity quartz sand. | Yes |
Lubricants like oils, greases and fluids are made by leading manufacturers such as Mobil, Q8 and Morris, and they are sold through suppliers to enterprises so they can keep their equipment operating at optimum.
The three key lubrication types are full-film, boundary and mixed. In the following sections, we’ll take a closer look at the different types of lubrication currently available, which are each suited to different mechanical processes, operations and environmental pressures.
Full-film lubrication – hydrodynamic and elastohydrodynamic
Full-film lubrication is a type of lubrication that can be further separated into two different subsets, which are known as elastohydrodynamic and hydrodynamic. Full-film lubrication seals individual components, protecting them from not only friction, but unwanted contaminants; however, this is no mean feat. Even parts that appear to be smooth have microscopic irregularities that form peaks and troughs on surfaces. In order for a full-film lubrication to be effective and completely seal components, it must always be thicker than the height of any protruding irregularities.
Hydrodynamic lubrication is defined by the process of two adjacent surfaces that are moving in a sliding motion relative to one another, while being entirely separated by a lubricant film to stop any friction from occurring, which would cause unwanted wear to parts.
Elastohydrodynamic lubrication is described as process of two adjacent surfaces relative to one another that are moving with a rolling motion while being separated by the film of lubrication fluid. The lubricant film present in elastohydrodynamic lubricating conditions is considerably thinner than the film seen in hydrodynamic lubrication. The pressure put on the film is also far greater. The term elastohydrodynamic is given to the process because the lubrication film is able to elastically alter its form to adapt to the rolling surface to effectively lubricate it, so it remains protected.
Boundary and mixed lubrication
Boundary lubrication is a type of lubrication associated with machinery that involves a lot of starting and stopping, and usually where shock-loading is present. There are some lubricants available that are enhanced with a specially designed additive package, giving the oil or grease improved operational abilities under such conditions, like anti-wear (AW) and extreme pressure (EP).
Machinery that operates at intense speeds can render full-film lubrication untenable, so boundary lubrication infused with EP and AW additives can assist by offering protection to parts. These cleverly formulated additives adhere to the metal surfaces of components and form a protective layer that takes the brunt of any wear and tear. Boundary lubrication is defined by a process when two adjacent surfaces are making contact and all that protects them is this additive layer.
Finally, mixed lubrication combines elements of hydrodynamic and boundary lubrication. While most of the metal surfaces are protected by a lubrication film, some raised irregularities in parts will meet but be mitigated by the AW and EP additives.
While all three types of lubrication are entirely different, they all depend on a base lubricant and a well-designed additive package that provides enhanced anti-wear properties. | Yes |
2018 Volume 84 Issue 5 Pages 835-842
In 2011, a food-borne disease caused by a myxosporan parasite, Kudoa septempunctata, of olive flounder was reported. Although freezing treatment for inactivating the parasite was proposed, there are reports that the meat quality of olive flounder is considerably reduced by such freezing treatment. In this study, we examined the suppressive function of ATP on denaturation of muscle protein and investigated the procedure for freeze-thawing olive flounder for consumption of high-quality raw fish as sashimi. Freeze-thawed meat which had been frozen while containing a high concentration of ATP immediately after instantaneous killing and then thawed slowly showed high quality for sashimi and the properties of myofibrillar protein were largely maintained. A method for measuring the metmyoglobin ratio in dark muscle of olive flounder was also developed. It was shown that autoxidation of oxymyoglobin in frozen meat of olive flounder containing a high concentration of ATP was suppressed. | Yes |
Which hormone controls the supply of sugar between muscles and blood?
Insulin is the hormone made by the pancreas that allows the body to use glucose from carbohydrates in the food. It helps to maintain sugar levels at a normal rate. The cells of the body need energy and sugar is what gives them energy. But however, sugar cannot go into most of the cells directly. Therefore insulin is needed as it unlocks the cell to allow sugar to enter it.
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Report a trivia answer.
We are sorry that you feel the need to report one of our answers. Please, tell us more regarding this problem. | Yes |
What is the use of common salt in soap industry?
Salt is one of the important raw materials for the soap. In soap manufacturing process, after the saponification reaction, soap is washed with concentrated brine solution (NaCl) to separate glycerin. Salt separates glycerol from water. Hence the "neat soap" is precipitated from the saponification solution by adding common salt. | Yes |
Preparation and Optimization of Biodiesel Production from Mixed Feedstock Oil
1Department of Chemical Engineering and Polymer Science, Shah Jalal University of Science and Technology, Sylhet, Bangladesh
2Faculty of Chemical and Natural Resources Engineering, University Malaysia Pahang, Kuantan, Pahang, Malaysia
In this paper, production of biodiesel from mixed feedstock oil (MFO) by three-step method and optimization of the process were studied by using regressive analysis. The random mixer of different oil was used for biodiesel preparation. The MFO contains 12 wt% free fatty acid (FFA) and its viscosity was 67.5 mm2/s. Because of higher FFA content transesterification method can’t be applied, so three-step method was conducted for biodiesel preparation. In the three-step method, the first step was saponification of the oil followed by acidification to produce FFA and finally esterification of FFA to produce biodiesel. In the saponification reaction, various reaction parameters such as oil to sodium hydroxide molar ratio and reaction time were optimized. Produced sodium soap was acidified with excess molar ratio of HCl to produced FFA. In the esterification reaction, produced FFA was reacted with methanol in presence of acid catalyst and the FFA content was reduced to 0.98wt%. A factorial design was studied based on viscosity for esterification reaction and developed to obtain the higher yield of biodiesel. Finally various properties of biodiesel such as FFA content, viscosity, specific gravity, cetane index, pour point etc. were measured and compared with biodiesel and petro-diesel standard.
At a glance: Figures
Keywords: mixed feedstock, FFA, esterification, factorial design, biodiesel
Chemical Engineering and Science, 2013 1 (4),
Received December 31, 2012; Revised April 04, 2013; Accepted July 30, 2013Copyright © 2013 Science and Education Publishing. All Rights Reserved.
Cite this article:
- Ferdous, Kaniz, et al. "Preparation and Optimization of Biodiesel Production from Mixed Feedstock Oil." Chemical Engineering and Science 1.4 (2013): 62-66.
- Ferdous, K. , Uddin, M. R. , Uddin, M. R. , Khan, M. R. , & Islam, M. A. (2013). Preparation and Optimization of Biodiesel Production from Mixed Feedstock Oil. Chemical Engineering and Science, 1(4), 62-66.
- Ferdous, Kaniz, M. Rakib Uddin, M. Rahim Uddin, Maksudur R. Khan, and M. A. Islam. "Preparation and Optimization of Biodiesel Production from Mixed Feedstock Oil." Chemical Engineering and Science 1, no. 4 (2013): 62-66.
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Presently the world’s energy needs are met through non-renewable resources such as petrochemicals, natural gas and coal. Since the demand and cost of petroleum based fuel is growing rapidly, and if the present pattern of consumption continues, these resources will be depleted in few years. Hence, efforts are being made to explore for alternative source of energy. An alternative fuel must be technically feasible, economically competitive, environmentally acceptable and readily available .
Energy consumption in developed countries has been increasing continuously over the past decades and is set to continue in the future. One possible alternative to fossil fuels is the use of fuels of plant origin . Such fuels allow for a balance to be sought between agriculture, economic development, and the environment. Their undoubted advantages include maintaining cultivation croplands that otherwise would be abandoned, potentially developing new industrial activates, reducing dependence on oil. There is increasing interest in developing alternative energy resources. An immediately applicable option is replacement of diesel fuel by biodiesel, which consists of the simple alkyl esters of fatty acids. Without modification, diesel engine vehicles can use biodiesel fuels [3, 4].
Biodiesel, defined as monoalkyl fatty acid ester (preferentially methyl and ethyl esters), presents a promising alternative fuel for use in compression-ignition (diesel) engines . Fatty acids esters are formed by transesterification, also called alcoholysis, of vegetable oils. This process has been widely used to reduce the viscosity of triglycerides, thereby enhancing the physical properties of renewable fuels to improve engine performance . It has been proven that biodiesel fuels have viscosities close to those of diesel. In addition, although the volumetric heating values are a little lower, they have high cetane numbers and flash points . Biodiesel is a strong candidate to replace petroleum diesel, as their characteristics are generally similar in addition to the many attractive advantages of biodiesel over petroleum diesel. These advantages include the following: it is plant oil rather than petroleum-derived and as such it is less toxic and comes from renewable sources; it is biodegradable; and relative to conventional diesel, its combustion products have reduced levels of particulates, carbon oxides, sulfur oxides, and under some conditions, nitrogen oxides [6, 7].
In Bangladesh the potentiality of producing oil source is investigated and it is found that the production potential is not too high. As we have a very large population, the edible oil sources cannot be employed for the biodiesel production. Moreover we have extreme limitation of land. So additional land acquiring is also impossible for the production of oil seeds. The oil seed source that can be used for biodiesel production in Bangladesh are Bakul oil, Pitraj oil, Karanja oil, Waste cook oil, Nahor oil, Seasame oil, castor oil etc. .
To reduce the burden on edible oils for biodiesel production we can use MFO sources. Different MFO sources are used for biodiesel production like rubber seed oil , used frying oil , castor oil , rapeseed oil, soybean soap stock, koroch seed oil, Karanja (Pongamia pinnata), Jatropha (Jatropha Curcas) , Neem (Azadirachta indica), Mahua (Madhuca indica),Simarouba (Simarouba indica), Jojoba (Simmondsia chinensis Link Schneider) [13, 14]. Recently the planning commission of India has recommended Karanja and Jatropha oil for biodiesel production in India .
There are different methods for biodiesel preparation like base or acid catalyzed transesterification [16, 17], two step method and three-step method . Encinar et. al. prepared biodiesel from waste cook oil by base catalyzed transesterification but the reaction yield was too low then two-step method was conducted to increase the reaction yield, Zheng et. al. produced biodiesel from waste cook oil by acid catalyzed transesterification but the molar ratio of oil to methanol was 1:74. In this method huge amount methanol required for reaction and additional cost involved for the separation of biodiesel.
In the present study biodiesel was prepared from non-edible mixed oil by three-step method to increase the reaction yield and minimize the methanol molar ratio. Additionally optimization study was done by the application of regression analysis to find out the better reaction conditions.
2. Materials and Methods2.1. Chemicals
Methanol (99-100%), ethanol (99-100%), sodium hydroxide pellets (96%), potassium hydroxide pellets (>84%), phenolphthalein (PH 8.2-9.8), acetone (99%), diethyl ether , hydrochloric acid (37%), iodine , sodium iodide, bromine, carbon tetrachloride, glacial acetic acid, potassium dichromate etc. All the chemicals were used as analytical reagent grade.2.2. Collection of Oil
MFO was prepared by random mixing of Bakul oil, Waste cook oil, Nahor oil, Pitraj oil, Karanja oil and Castor oil. The oil composition was 33% WCO, 25% pitraj oil, 25% castor oil, 7% bakul oil, 5% nahor oil, 5% karanja oil. Oils were collected from the local sources of Sylhet city in Bangladesh. Finally the MFO was filtered and its properties were measured.2.3. Preparation of Biodiesel by Three-Step Method
Three-step method consist of Saponification followed by acidification to produce FFA and finally esterification of FFA to produce biodiesel.
For saponification process required amount of MFO was taken in a three necked flask and mixed with different stoichiometric amount of aqueous sodium hydroxide (NaOH) solution. The mixture was heated under reflux with vigorous stirring at temperature of 100 ℃ for different time. The reaction was stopped by cooling the reaction mixture. Aqueous sodium hydroxide solution was prepared by dissolving required amount sodium hydroxide pellets in 60-90 mL water. The reaction time and different molar ratio of oil to sodium hydroxide solution through saponification process were optimized.
After saponification, produced sodium soap solution was treated with different stoichiometric amount of concentrated hydrochloric acid at a temperature of 65 -70 ℃ under reflux with vigorous stirring. After dissolving the soap, the fatty acid content was separated in separatory funnel. After separation, hot water wash was given for removing mineral acid from the fatty acid. The FFA content was determined by titrimetric method. The different molar ratio of soap to hydrochloric acid was given and the ratio was optimized.
2.3.3. Esterification of FFA
When acidification was completed, produced FFA was reacted with different stoichiometric amount of methanol under reflux with vigorous stirring at different temperature, catalyst concentration, different molar ratio of methanol to FFA and different time. All the reaction parameters were optimized. Silica gel was used during esterification reaction to adsorb water produced in esterification reaction.
After preparing the biodiesel from MFO various physico-chemical properties were measured and compared with the standard biodiesel. The yield of biodiesel was calculated by the following equation:
To determine FFA of sample and biodiesel, 1mL of oil and biodiesel were weighed in gm , then dispersed in 5mL diethyl-ether solution followed by titration against 0.1 M KOH by the method described in AOCS Aa 6-38 . Saponification value (SV) was determined by method described by Jeffery et al. .To determined S.V. 2 gm sample was taken in 50 mL alcoholic KOH then heated at 65 °C with vigorous stirring for 30 min and titrated against 0.5 M hydrochloric acid . The iodine value (IV) was determined by titrating the sample with 0.01 N sodium thiosulphate and chemical reagents until the disappearance of blue color. Iodine value was calculated by following equation:
where, V1 and V2 are the volume of sodium thiosulphate (mL) required for titration with sample and blank titration, S is the concentration of Na2S2O3 in Normality, W is the weight of oil sample in gm. Physical properties color, moisture content and density of the sample were by the following ASTM D 1500, ASTM D 1744 (Karl fisher method), ASTM D 1480/81 and ASTM D 240. Viscosity, cloud point, pour point were determined by standards ASTM D445 respectively.
3. Results and Discussion3.1. Characterization of MFO
The properties of MFO such as viscosity, specific gravity, moisture content, saponification value, pour point, cloud point etc were measured and presented in Table 1.3.2. Preparation of FFA from MFO
FFA was prepared from MFO by saponification followed by acidification. Saponification was done by the method described above. Saponification was done with different stoichiometric amount of NaOH. After saponification and acidification FFA was produced. The results are present in Figure 1. From the Figure 1 it can be seen that, the optimum molar ratio of oil to NaOH was 1:2 and reaction time was 2.0 h.
3.3.1. Effect of Methanol to FFA Molar Ratio
The methanol to FFA molar ratio is one of the important parameter that affecting the FFA conversion to biodiesel. The effect of methanol to FFA molar ratio on conversion of FFA was investigated at fixed temperature and catalyst concentration. The results are represented in Figure 2. From the Figure 2, it was found that the FFA conversion to biodiesel was 98% at 6:1 molar ratio of methanol to FFA. Further increase in methanol to FFA molar ratio conversion does not increase. The optimum molar ratio of methanol to FFA was 6:1.
3.3.2. Effect of Catalyst Concentration on Esterification
Catalyst concentration has a significant role on conversion of FFA to methyl ester. Increase of catalyst concentration increases the percentage of FFA conversion. At a certain catalyst concentration the conversion was higher. HCl used as a catalyst in Esterification reaction. The effect of catalyst concentration on conversion of FFA was investigated the results are represented in Figure 3. From the Figure 3, it can be seen that the conversion was 98 % at the catalyst (HCl) concentration of 5 wt% of FFA. Further increasing the catalyst concentration conversion does not increase. The optimum catalyst concentration was 5 wt% of FFA.
3.3.3. Effect of Silica Gel on Esterification Reaction
Silica gel adsorbs the water produced in esterification reaction. Hence increase the reaction rate. The effect of silica gel was studied in esterification reaction by taking 7.5 gm silica gel for 50 g FFA. Further increasing of silica gel, the conversion remains unchanged. The results are presented in Figure 4. From the Figure 4, it can be seen that 98% conversion was achieved within 90 minutes and reaction rate was increased.
3.3.4. Effect of Temperature
Temperature has a significant effect on conversion of FFA to methyl ester. By increasing temperature FFA conversion was increased. At a certain temperature the conversion was higher. The effect temperature on conversion of FFA was investigated the results are represented in Figure 5. From the Figure 5, it can be seen that the conversion was 98 % at 60 ℃ temperature. Further increasing of temperature the FFA conversion does not increase. The optimum temperature was 60 ℃.3.4. Optimization Study
Four factors (methanol to FFA molar ratio, catalyst concentration, temperature and reaction time) affect the biodiesel production process from MFO. To study the optimization of process, a factorial design was carried out. The experiments were carried out according to half-Replicate of 24 full factorial design. Table 2 shows the decoding values for methanol to FFA molar ratio, catalyst concentration, reaction temperature and reaction time. Eight set of experiments were run for the factorial design and the results are shown in Table 3.
Where Y is the viscosity of biodiesel and is average value of Y. The sample variances where determined and tested for homogeneity on the basis of Cochran’s criterion. It was found that the sample variances are homogeneous for the significance level α = 0.05 and the number of degrees of freedom ν1 = 4 and ν2 = 8 and the error mean square was 1.09.
The complete regression equation describes the contributions of the various factors on the outcome (response) of the biodiesel conversion.
The coefficients of the regression equation were estimated and the significance of the coefficients was tested using the student T-test. Only two coefficients appeared as insignificant for the significance level α = 0.01.Neglecting the insignificant coefficient the final regression equation becomes as:
Using the Fisher’s test the adequacy fitness of the regression equation was determined. With α = 0. 01, ν1 = 1 and ν2 = 32 the tabulated value of Fisher’s F was 7.6, where the experimental value was 5.82. Therefore the equation fits in the experiment.3.4. Properties of Biodiesel
The properties of produced biodiesel such as viscosity, FFA content, moisture content, pour point, cloud point, saponification value, iodine value, specific gravity etc. were presented in Table 5 and compared with standard values. The reaction yield was 82%.
Table 5. Properties of biodiesel produced from MFO and comparison with standard biodiesel and diesel values
Biodiesel was prepared from MFO by three-step method; in three-step method aqueous sodium hydroxide solution was used for saponification. The optimum molar ratio for saponification by aqueous sodium hydroxide was 1:2 oil to NaOH and reaction time was 2.0 h at 100 ℃. In acidification the molar ratio of soap to hydrochloric acid was 1:1.5 for sodium soap. In Esterification the optimum molar ratio of methanol to FFA was 6:1, the catalyst (HCl) concentration was 5 wt% of FFA, the reaction temperature was 60 ℃ and the reaction time was 2 hour, with silica gel reaction time was reduced to 80 min and FFA content was reduced to 0.98 %. A factorial design was applied to find the optimum conditions for esterification reaction. At optimum conditions 98% conversion of the FFA to FAME was obtained. The properties of produced biodiesel such as viscosity, specific gravity, cloud point, pour point, flash point etc. are nearest to the petro-diesel. The present experimental results support that produced biodiesel from MFO by this method can be successfully used as diesel.
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About author :
Naga Jyothi*, Dr. Hindustan Abdul Ahad
B. Pharmacy, Balaji College of Pharmacy, Anantapur, AP, India
The World Anti-Doping Agency, established in 1999 to deal with the increasing problem of doping in the sports world. The banned substances and techniques fall into the following categories: androgens, blood doping, peptide hormones, stimulants, diuretics, narcotics, and cannabinoids.
KEY WORDS: sports, doping, athletes
Blood doping :
Blood doping is the injection of red blood cells, related blood products that contain red blood cells, or artificial oxygen containers. The unnatural level of red blood cells improves oxygen transport and athletic endurance; thus, it is prohibited in most events.
Banned androgenic agents :
Banned androgenic agents are either anabolic steroids, which increase testosterone and epitestosterone, thereby improving muscle strength and endurance. A Few of the banned drugs are endogenous, that is they are normally produced in the human body, most of the banned drug are exogenous drugs chemically produced.
a. Exogenous anabolic androgenic steroids
E.g., Methyldienolone, Norboletone, Landrostendiol, Bolandiol, Mestenolone, Dehydrochlormethyl testosterone and Dexosymethytestosterone.
b. Endogenous anabolic androgenic steroids
E.g., Androstenediol, Androstenedione, Dihydrotestosterone, Prasterone and Testosterone
Hormones and related substances
Peptide hormones increase bulk, strength, and oxygen-carrying red blood cells.
E.g., erythropoietin (EPO), growth hormone (hGH), Insulin-like growth factors, Mechano growth factors (MGFs), chorionic gonadotropin (banned in men only), somatotrophin (growth hormone), insulins and corticotrophins, corticosteroid
Stimulants directly affect the central nervous system, increasing blood flow and heart rate.
E.g., Amphetamines, beta-2 agonists, ephedrine, pseudoephedrine, fencamfamine, cocaine, methamphetamines and mesocarb
Diuretics and masking agents :
Diuretics, which increase the production of urine, and masking agents, chemical compounds which interefere with drug tests are banned for two reasons.
Decreasing water retention and thus decreasing an athlete’s weight, an important consideration in many speed sports, they increase the speed of an athlete.
Increased urine production depletes the concentration of both the banned drugs and their metabolites, making their detection more difficult.
Masking agents, on the other hand, work by making drug tests ineffective, leading to false-negative results.
E.g. Hydrochlorothiazide, Indapamide, Metolazon, Spironolacton, Triamterene, Amiloride, Bendroflumethiazide, Chlorothiazide, Furosemide
Narcotic analgesics decrease the sensation of serious injuries, allowing athletes to continue training or competition after serious injuries. While some painkillers are allowed, including codeine, the following are banned:
E.g., Buprenorphine, Dextromoramide, Diamorphine (heroin), Fentanyl, Methadone, Morphine, Oxycodone, Oxymorphone, Pentazocine and Pethidine
Glucocorticoids are a class of corticosteroids that affect the metabolism of carbohydrates, fat, and proteins, and regulate glycogen and blood pressure levels.
Beta blockers :
Beta blockers are prohibited during competition in a number of sports; out of competition, they are prohibited only in archery and shooting.
E.g., Acebutolol, Atenolol, Betaxolol, Carvedilol, Labetalol, Metoprolol, Oxprenolol and Sotalol
Be sportive while you are in sports and don’t give chance to anybody to blame you. | Yes |
Flexible electronic devices generally integrate inorganic materials on a polymer substrate (such as metal films on a deformable polymer). The properties of these inorganic/organic hybrids are of great practical and theoretical. There have been numerous experimental and theoretical study of their mechanical properties, especially the failure strain of polymer-supported metal films. The fracture strain of polymer-supported thin metal films is significantly higher than that of free-standing metal films due to the suppressed necking in the supported metal film. However, there are few studies of the thermal conductivity of extremely strained metal films and inorganic/organic hybrids. Here, we experimentally measure the thermal conductivity of extremely strained polyimide-supported Au nanofilms (100 nm Au on 25.4 µm polyimide). The systematic study of interrelated mechanical, electrical, and thermal properties leads to a better understanding of the performance of flexible electronic devices across a range of realistic operating conditions. In addition, the validity of Wiedemann-Franz law for extremely strained metal is evaluated by comparing the measured thermal and electrical conductivities. | Yes |
The cast aluminum alloy castings in the aerospace field require high requirements. Most companies still use inert gas rotating degassing and filtering operation mode for the purification of molten aluminum.
Small aluminum alloy die-casting enterprises, due to low casting requirements and outdated equipment technology, are basically machine-side furnace melting, and do some simple slagging treatment to produce castings. It is better to use inert gas or non-toxic refining agent to do some simple refining treatment or filter the aluminum liquid with a filter plate, and start production without testing the treatment effect of the aluminum liquid. This kind of treatment has poor quality of molten aluminum, low production grade, relatively high cost, and difficult enterprise development.
Some large and medium-sized aluminum alloy die-casting enterprises mostly use centralized melting, slagging in the furnace, and organizing production after degassing and slagging. The molten aluminum undergoes inert gas online degassing and foam ceramic filtration to produce castings.
Advanced aluminum liquid purification treatment technology: online degassing treatment equipment, purification treatment selects nitrogen rotating degassing and ceramic foam filter plate filtration, and the treated aluminum liquid has an equivalent density of less than 1. Advanced processing equipment like this is used more in new scale production enterprises. Companies that choose metal gravity casting and mass-produce automobile and motorcycle castings basically use continuous melting furnace aluminum, inert gas online degassing, and ceramic filter plate filtration to process molten aluminum. The quality of molten aluminum processed by these methods can be guaranteed, the efficiency is high, and the production cost is relatively low; it is good for mass production.
More and more high-quality aluminum alloy castings have begun to be produced in my country, and the requirements for molten aluminum are constantly improving. It is a necessary way to improve the purification equipment and technology of molten aluminum. | Yes |
JD-21689 DOG. Bernese mountain puppy sitting next to three bernese mountain dogs sitting
DOG. Bernese mountain puppy sitting next to three bernese mountain dogs sitting
Also known as Berner Sennenhund
Please note that prints are for personal display purposes only and may not be reproduced in any way.
© John Daniels / ardea.com
Babies, Baby, Bernese Mountain Dog, Bernese Mountain Dogs, Breeds, Dog, Domestic, In Garden, Lines, M Ammals, Mammal, Out Side, Park, Parks, Pet, Pets, Puppies, Puppy, Row, Rows, Sitting, Work Breeds, Young
Standard periodic table, element types
Standard periodic table, colour-coded for element types. The periodic table shows the chemical elements ordered by atomic number (number of protons in the nucleus), but arranged in rows (periods) so that elements with similar chemistry occur in the same vertical column (group). Here, blocks of elements with similar chemical properties are shown by the colours identified in the key at bottom. Each element is represented by its chemical symbol. Above each symbol is the element's atomic number, and below it is the element's name, as shown in the labelled example at lower right.
© VICTOR HABBICK VISIONS/SCIENCE PHOTO LIBRARY
Tea Plantation Gorreana tea factory harvesting of
Tea Plantation Gorreana tea factory harvesting of the leaves takes place when the majority of the branches have three leaves, as each of the leaves has a different age, they also have different chemical compositions each type of leaf will give the tea it produces a different taste and aroma Date:
© Ardea - All Rights Reserved
Azores, Crop, Crops, Europe, European, Factory, Field, Fields, Gorreana, Industry, Island, Leaf, Leaves, Miguel, Plant, Plantation, Plantations, Plants, Portugal, Rows, San, Tea | Yes |
Room Temperature Detachment Nanolithography Using a Rigiflex Polymeric Mold
We report on detachment nanolithography of an organic thin film at room temperature mediated by ultraviolet (UV) exposure. A nanopatterned, UV curable polyurethane acrylate (PUA) mold was placed on a spin-coated organic film made of 4,4′-bis[N-1-napthyl-N-phenyl-amino]biphenyl (NPB) under a low pressure (1–2 bar). A higher work of adhesion at the organic/mold interface induced detachment of the contacting layer on silicon or gold substrate, resulting in well-defined nanopatterns without a residual layer. The detachment was highly improved by a short-term UV exposure, rendering the film surface free from contaminant hydrocarbons with a lower cohesive force, as confirmed by Fourier transform infrared (FTIR) spectroscopy and measurements of contact angle of water.
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Publication date: 2008-07-01
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Using Sodium Bicarbonate in Household Cleaning
Baking soda is an affordable multi-purpose cleaning solution that’s effective in multiple household chores.
Before manufacturers began producing chemical household cleaners, humans developed intelligent routines and cleaning hacks that pass down through generations.
Using baking soda, or bicarbonate of soda, for all types of polishing, scrubbing and unblocking is one of them.
It’s safe to say that since people have been using bicarbonate of soda for cleaning their homes for centuries, there must be something that’s working.
When searching for a cleaning remedy, you’re almost guaranteed to find a suggestion that involves baking soda and or vinegar.
A lot of cleaning products nowadays actually include bicarbonate of soda as an ingredient.
In this post, we’ll be looking into what bicarb of soda is, why it works for cleaning and the various ways you can include it in your household routine.
Why Is Bicarbonate of Soda Good for Cleaning
Before we go into why baking soda works for cleaning, let’s first break down what it is so we can look deeper into what’s going down at a molecular level.
What is it?
Bicarbonate of soda’s intended use is as a raising agent in bread and cakes as an alternative to yeast.
Baking soda is an alkali, so to activate it, there needs to be an acid present. In food, this is commonly cream of tartar, milk, or yoghurt. In cleaning, we might use vinegar or lemon juice to cause the same raising effect.
Once the reaction occurs, the bicarb and acid mixture will expand by filling with carbon dioxide (CO2) and creating a foamy substance.
You may have seen this reaction in a classroom. Check out these science experiments to see the power these two simple ingredients can have.
Why Is it Good for Cleaning?
Most odours are acids, so an alkaline will neutralise the substance bringing it closer to water and taking out the smells.
Baking soda has fine particles that can help with scrubbing off hard-wearing dirt.
Breaks Down Grime
Bicarbonate of soda is an alkali which means it is highly effective in dissolving grease and oils.
Most cleaning products designed to break down fats and grease are full of harsh chemicals which can be potentially damaging to skin and surfaces or harmful when inhaled.
Since baking soda is mild, it’s many people’s preferred option for cleaning the house.
Baking Soda or Bicarbonate of Soda for Cleaning
You will have noticed we are using baking soda and bicarbonate of soda interchangeably. That’s because they are, in fact, the same thing.
Whether you call it bicarbonate of soda like the Brits and Aussies, or baking soda in the US, we’re all talking about the same powdered substance.
However, using Baking Powder for cleaning won’t be as effective due to the presence of cream of tartar and other potential ingredients. It won’t do any damage but it’s essentially a diluted baking soda.
How to Use Bicarbonate of Soda to Clean
Most cleaning hacks involving baking soda will include making some form of a paste with vinegar, water or lemon juice.
They’ll probably also need a decent amount of elbow grease.
For some bigger household items, the process is slightly more complicated. We’ve split these items into their own categories to give more detailed instructions.
What should you not clean with baking soda?
Before we start suggesting things you can clean with bicarb, we want to warn you against items that can be potentially damaged by it.
A lot of things that shouldn’t ever be cleaned with baking soda are valuable, so it’s worth knowing what these are.
Although bicarb is a mild substance, there is still potential to harm surfaces depending on their chemical make-up.
Experts suggest that baking soda should not come into contact with:
- Cleaning Silver
The abrasive nature of bicarbonate of soda is too rough for silver and should be avoided (the same goes for gemstones).
Sterling silver may be okay, but we wouldn’t suggest risking it.
- Cleaning Marble
The rough particles in baking soda may wear down the sealant on marble countertops.
- Cleaning Aluminium
Be careful with which dishes you’re scrubbing as Items like pans or baking trays may be aluminium, which can end up discoloured or even rusted after being left in contact with baking soda.
- Anything Gold or Gold Plated
When washing up your fine gold-rimmed china or anything with any gold on it at all, definitely don’t reach for the baking soda.
Gold is a very soft metal. The abrasive texture of bicarbonate of soda can scratch, or even remove, the gold.
Bicarbonate of Soda for Cleaning Drains
- Loosen the grime and get things going by pouring a large pot of boiling water down the drain.
- Pour one cup of baking soda into the drain, followed by a mixture of one cup of vinegar and a cup of water.
- Cover up the drain pipe and wait for 5-10 minutes.
- Whilst you’re waiting, boil another pot of water.
- Once the time’s up, pour the second batch of boiling water down the drain.
In step 2, the solution of baking soda and vinegar will cause a foaming reaction that gets into the grime in the pipes.
Remember making vinegary-smelling volcanoes in school? This cleaning remedy is the same reaction, minus the red food colouring!
The boiling water acts as a flush, that produces force and pushes out the built-up dirt.
If your drains are significantly blocked, you may need a more industrial unblocker to dissolve the dirt and trapped food.
Bicarbonate of Soda for Cleaning Ovens
How to Make a Bicarbonate of Soda Oven Cleaner
- 90g or ½ cup of baking soda
- 2½ – 3 tablespoons or 35-55ml water depending on desired consistency
You will need:
- Any bowl or container (not aluminium)
- Rubber gloves
- Small spatula or flat scoop for spreading the paste
- (If you have any old spatulas that came with hair removal cream these work great for spreading on the thick paste.)
- Clean Toothbrush
- Cloth or paper towels
- Vinegar (optional)
- The very first step for cleaning your oven and all racks and trays will be making the bicarb paste.
- After you’ve made your paste, take out all the racks and baking trays in the oven and place on the side.
If you’re also cleaning these, spread the paste on any burnt bits or grease and rub in with your glove or use a spatula tool. Leave this to sit.
- If you aren’t cleaning your oven racks and baking trays, this is your step 1 after removing all the shelves and trays. Spread your paste on any problem areas of your oven first with a thick layer, and then use a thinner layer to do the rest. Avoid any heating elements but remember to coat the glass and shelf grooves.
- Leave the paste to sit for 15 minutes.
- Baking trays and racks step 2: At this point, your baking shelves and racks have probably had the solution on for 5-10 minutes.
Rub the mixture with a gloved finger and see whether the burnt bits are lifting off. If they are, you can use a scourer to remove the bicarb mixture and then rinse off in the sink.
If the dirt isn’t coming off, try using a scourer, toothbrush or a plastic spatula to scrub off the burnt bits, then rinse.
- Once the 15 minutes is up, see how well the oven grime is coming off by using your gloved finger to rub a small section.
If it’s lifting already, you can remove the paste with dry paper towels, followed by a wet cloth to remove any residue left over.
If the grime isn’t budging, you can leave the paste on for longer (overnight for stuck-on dirt).
Alternatively, you can try scrubbing at the stuck bits with a scourer, or utensil that can get under the hard grime without scratching at the glass or oven coating.
Once you’re satisfied with your oven, remove the paste with paper towels followed by wiping over with a wet cloth to remove any leftover residue.
|Top Tip: A neat trick to see if you’ve missed any is to wipe over the oven with vinegar. If any bubbling occurs, then there’s still some baking soda left over. This isn’t an essential step as baking soda is edible so won’t do any harm.
How to Use Bicarbonate of Soda for Cleaning a Mattress
We won’t go into talking about all the nasties that are in our mattresses, but we will say that it’s worth giving them a good clean once in a while.
Cleaning your mattress with baking soda is a pretty easy job, but it’s worth doing in the morning and leaving on all day for the best results.
You only need a few items to clean a mattress, and you’ll probably have them at home.
- Vacuum cleaner – handheld or stair tool works well.
- Bicarbonate of Soda
- Using a sieve, sprinkle bicarbonate of soda all over your mattress with a focus on where the most dirt will be. If you accidentally pour too much just spread the powder around with your hand.
- Leave the powder for as long as possible – ideally the whole day. The baking soda absorbs any dirt, moisture out of the mattress as well as neutralising any odours.
- After you’ve left the sodium bicarbonate for as long as possible, use your vacuum cleaner to suck up all the powder.
Keep going after you think you’ve got it all to avoid clouds of white powder every time you jump on the bed.
- If you’re cleaning any liquid mattress stains, i.e. blood, make a thick paste of bicarbonate of soda and water and spread onto the stain. Leave the stiff paste on the stain for a few hours and then remove with a hoover or cloth.
- This stain removal technique will work best when the stain is fresh.
Follow this process to clean and deodorise any other soft furnishings, such as chairs and sofas.
How to Use Bicarbonate of Soda for Cleaning Carpets
Baking soda is a very neutral, natural product.
People have been using it to safely freshen up carpets and rugs, way before chemically manufactured liquid carpet cleaners were ever invented by a marketing department.
Baking soda on the carpet is safe and is an excellent deodoriser, but it doesn’t get rid of allergens or grime.
The only way it would have benefits in reducing allergens is that you have to give your floors and fabrics an extra-good vacuuming to suck up all the white dust.
If you’re looking to clean dirty carpets, we recommend cleaning stains and dirt as best as possible with your normal carpet cleaner.
You can then use baking soda to reduce any leftover odours in the carpet.
- Sprinkle baking soda all over the carpets and let it sit for as long as possible up to overnight.
- Remove all the bicarbonate of soda from your carpet with a vacuum cleaner.
- Enjoy your odour-free carpet!
Bicarbonate of Soda for Cleaning a Microwave
If your microwave needs a good clean, save your arm muscles and put your microwave to work.
- Simply use a microwave-safe bowl or mug and use two tablespoons of baking soda and add about 250ml or 1 cup of water, then mix them up.
- Place the bowl in the microwave for about 2-3 minutes depending on how dirty it is.
- The baking soda neutralises any stinky smells, and the water creates steam that loosens any dirt. Wipe down the inside of your microwave, and you’re done!
If you want, you add some lemon juice to the mixture as the lemon juice may add a pleasant smell and also work harder at removing the built-up grime.
Ways to Use Baking Soda or Bicarbonate of Soda for Cleaning
Sprinkle some bicarb into your vase and add vinegar and warm water to cause a foaming reaction then scrub to remove any stain or gunk.
Clean your hairbrushes and combs
Soak combs and brushes in a mixture of 1 teaspoon of baking soda and 500 ml of warm water for an hour then rinse with water and leave to dry.
Soaking burnt pots and pans (not aluminium)
Leave a paste or liquid mix of bicarbonate of soda and hot water in any burnt pots and pans, leave for 20 minutes+, then scrub away.
Sprinkle a layer of baking soda over your upholstery and leave as long as possible before vacuuming off.
Deodorising fridges and smelly cupboards
Put open containers of baking soda in fridges and underneath sinks to absorb bad odours and change once a month.
Where to Buy Bicarbonate of Soda for Cleaning
Where to Find Baking Soda in a Supermarket
Bicarbonate of soda is likely to be in the baking aisle in most supermarkets.
Where to Buy Baking Soda Online
Here are our Clean and Tidy Living favourites for online baking soda options.
Where to Buy Baking Soda in Bulk
Since baking soda is commonly using a teaspoon at a time in cooking, it can be challenging to know where to buy large quantities of baking soda.
If bicarb is going to become a key part of your household cleaning routine, it’s worth stocking up on the stuff.
Comes with a free e-book with 50 uses of Bicarbonate of Soda in the home!
The Round-Up of How to Use Bicarbonate of Soda for Cleaning
It’s safe to say that here at Clean and Tidy Living we are big advocates of using bicarbonate of soda for cleaning.
Not only is it effective in breaking down stains, grime and odours, but it’s also affordable and easy to get your hands on.
Also, if you’re not so keen on using chemicals in your home then it’s a great alternative to commercial cleaning products.
We hope that this guide to all things baking soda has been helpful in explaining what it is, how it works and how to use it.
Let us know in the comments how you use bicarbonate of soda in your cleaning routine! We’ll keep adding to the list with all your bicarb tips and tricks.
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- How To Clean A Very Stained Toilet Bowl | Yes |
What Is Kaolin Clay?
Kaolin clay is a natural clay that is used in skincare and cosmetic formulations to help draw out excess oil or sebum from the skin and to gently exfoliate. Kaolin clay is also used to help bulk out product, act as a mild preservative and improve the longevity of powdered cosmetics.
Kaolin, also known as China clay, is a naturally occurring porous soft clay that is rich in the mineral, kaolinite. Both are given their names from ‘Kaoling’ which is the hill where it was first mined. Pure kaolinite is white; often other minerals are added to kaolinite to produce kaolin clay. These minerals give the clay a slight colour such as pink hue from iron oxide or a green color from decomposing plant material.
Kaolin is mined all over the world, from China to Europe to the United States. In Chinese tradition Kaolin clay was used to make porcelain and to treat stomach upsets. Nowadays, in addition to use in cosmetics and personal care products, kaolin is a component of a variety of products, such as porcelain, toothpaste, paint, paper, stomach medications, and more.
the good: Kaolin’s main benefit is that it draws out oil, lifting impurities from the skin. It also has a mild exfoliating effect and helps to preserve the products that it is in.
the not so good:Kaolin clay can be drying when it has been formulated in higher concentrations or when it is used by itself. Be mindful of this, particularly when using clay masks.
Who is it for?Most skin types except those that have an identified allergy to it and dry or dehydrated skin types.
Synergetic ingredients: Works well with most ingredients.
Keep an eye on:Nothing to keep an eye on here.
Four Benefits of Kaolin Clay
In cosmetics and personal care products, kaolin is used to cleanse and exfoliate the skin, as well as add absorbency, texture, and bulk to products. It is commonly found in face powders, face masks, creams and lotions for oily skin, bath powders, foundation, powdered blush, deodorants, and soaps.
- Absorbs excess oilKaolin is used as it is able to absorb excess oil from the skin’s surface. This can help to reduce shine and give the skin a matte appearance. Primarily is it used to draw out oil from the skin, lifting dirt, and other impurities from the pores. This is why kaolin is a popular ingredient in clay masks for oily and acne prone skin.
- SoothingKaolin clay is often used to help reduce irritation and redness. While this property of kaolin clay has not been fully investigated, anecdotally it often has this effect on irritated or sensitized skin. It is good to keep in mind that kaolin can dry out the skin, potentially introducing dryness and irritation. If your skin is irritated kaolin should not be your main produce to help soothe the skin.
- Exfoliating Kaolin is used in exfoliating products because it does not completely dissolve in water; rather, it forms a paste with very fine particles. These particles serve as a gentle abrasive that can exfoliate the top layers of skin, removing dead skin cells, makeup, excess oil, dirt, and other impurities that may have accumulated on the surface during the day. Gentle exfoliation becomes even more important with age since the skin’s natural cycle of shedding dead cells slows down, however, kaolin is more suited to oily or combination skin types.
- Cosmetics Kaolin is also used in cosmetic powders and foundations. Powders and foundations that contain kaolin are used to prevent excess shine from oil. Kaolin absorbs the oil, resulting in skin that has a fresh, matte appearance. Its oil control properties allow the makeup to stay on longer, withstanding perspiration and wet or humid conditions. In addition, kaolin-based products effectively hide imperfections and fine lines.
- Preservative Lastly, kaolin functions as a natural preservative because of its absorbent properties. In a water-based formulations, kaolin absorbs the water, preventing the growth of bacteria, yeasts, or molds. These microbes cannot survive without water. Therefore, kaolin is an excellent mild preservative ingredient for skincare and cosmetic formulations.
Is Kaolin Clay Safe?
Kaolin clay is considered to be safe for its indicated uses in skincare and cosmetic products. The Cosmetic Ingredient Review Expert Panel, a group that investigates the safety of skincare and cosmetic ingredients has assessed the data on kaolin. According to their review, kaolin clay Is safe in cosmetic and skincare formulations. It is a non-sensitizing ingredient however; it can cause dryness when used in higher concentrations or by itself.
Williams, L & Haydel, S, 2010. ‘Evaluation of the medicinal use of clay minerals as antibacterial agents’. International Geology Review, vol. 52, is. 7, pp. 745-770. Moosavi, M, 2017. ‘Bentonite Clay as a Natural Remedy: A Brief Review’, Iranian Journal of Public Health, vol. 46, is. 9, pp. 1176-1186. Hernández, A, 2019. ‘Colloidal and Thermal Behaviours of Some Venezuelan Kaolin Pastes for Therapeutic Applications’, Minerals, vol. 9, is. 12. | Yes |
We studied the thermal conductivity of various transition-metal oxides with the spinel structure (MnV2O4, FeV2O4, CoV2O4, and Mn3O4) upon varying the temperature and magnetic field. We found that for the spinel oxides having V3+ ions (two electrons in the t2g states) at the octahedral site, the orbital ordering suppresses the thermal resistivity (inverse thermal conductivity) in contrast to purely magnetic ordering, indicating that the orbital fluctuation of the V t2g states is the main factor affecting the thermal conductivity. On the other hand, for Mn3O4, which has Mn3+ ions (one electron in the eg states) at the octahedral site, the thermal resistivity is suppressed in association with the successive magnetic phase transitions with decreasing temperature and increasing magnetic field. This can be explained by the frustration of Mn3+ spins and the fluctuation of Mn3+ eg orbitals.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2014 Dec 8|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics | Yes |
Single-walled carbon nanotubes (SWNTs) possess many unique electrical and mechanical properties. They can be conducting, semiconducting or insulating, based on their chirality. They also have a high surface area and a high strength-to-weight ratio. These properties make SWNTs desirable for many applications, including nano-electronic devices and composite materials. However, applications such as composite materials require large quantities of SWNTs, making them infeasible at current nanotube costs.
At LACER, we are developing flame-based approaches to producing SWNTs. Diffusion flames may provide a synthesis route capable of achieving the necessary production rates; however, past attempts have led to low-quality nanotubes with amorphous carbon impurities.
Our approach relies on Flame Design and the addition of silicon to produce clean SWNTs, as seen above. Also shown is a photograph of the flame used to produce the materials. The flame is a laminar inverse diffusion flame, in which ferrocene is used as the seed catalyst’s source of iron. | Yes |
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Biochemistry Youtube Channels
About Youtuber I'm Dr Prakash Mungli, MD, physician professor and a passionate teacher of Medical Biochemistry. Currently I'm Assistant Dean of Student Affairs, Chairman of department of Molecular Sciences and Professor of Biochemistry at University of Medicine and Health Science, St Kitts. For brief write up on some important biochemistry concepts and other useful topics specially on food and nutrition, obesity, weight loss tips please visit my site.
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About Youtuber Welcome to quick biochemistry basics. The videos in this channel are short and to the point, with few animations, that allows you to grasp the basic concepts of biochemistry and molecular biology quickly.
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Since Sep 2017
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India About Youtuber This channel features everything about Biochemistry by Dr Rajesh Jambhulkar. Follow to keep up with the latest updates.
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London, England About Youtuber The Biochemical Society promotes the future of molecular biosciences; facilitating the sharing of expertise, supporting the advancement of biochemistry and molecular biology, and raising awareness of their importance in addressing societal grand challenges.
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MD About Youtuber The Society's mission is to advance the science of biochemistry and molecular biology and to promote the understanding of the molecular nature of life processes.
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About Youtuber Mechanisms and Screencasts to support Winona State University's Biochemistry courses CHEM 405-408.
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Tempe, Arizona About Youtuber Chemistry and biochemistry are central to many educational and technological initiatives in our modern society. The Department of Chemistry and Biochemistry at Arizona State University offers advanced training for those who seek to best position themselves to take advantage of the rich diversity of career and mission opportunities in contemporary molecular science.
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Bhuj, Gujarat, India About Youtuber Myself Dr. Amitkumar Maheshwari MBBS MD (Biochemistry). I am working as CONSULTANT BIOCHEMIST and MEDICAL EDUCATOR. This is the channel for the basics fundamentals related to biochemistry and their applications in the field of medicine which will be useful to MBBS, PG, Nursing and DMLT students. At the end of the every video there will be MCQS asked in various entrance examinations (AIIMS, NEET) which will be helpful to the MBBS and NEET PG aspirants.
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RhinoChem 2170 is a two-component, 100% solids, rapid curing elastomeric lining displaying excellent chemical and immersion characteristics.
RhinoChem 2710 is highly cross linked, which results in a membrane liner that is extremely dense. It provides superior protection against corrosion and excellent resistance against chemical attack from a variety of commercial and industrial chemicals including: Acetic Acid to 10%, Ammonia to 5%, Hydrochloric Acid to 15%, Hydrogen Peroxide to 10%, Sodium Hydroxide to 50%, Sulphuric Acid to 50%, Salts, Bleach and more.
For further information on RhinoChem 2170's chemical resistant capabilities, please speak with the Rhino Linings Technical Department.
RhinoChem 2170 can be spray applied to metal, wood, concrete, brick, fibreglass or geotextiles, creating a monolithic, seamless lining conforming to any shape or size, and is especially suitable for applications that require a fast turnaround and an extended life cycle.
RhinoChem 2170 is the premium chemical resistant polyurethane in the Rhino Linings Polyurethane range.
Primary and Secondary Containment, Chemical processing equipment, Tank Linings, Wet Wells, Water and Wastewater Applications, Immersion Applications in ambient and elevated temperatures.
Technical Data Sheet: RhinoChem 2170 | Yes |
Pyrroloquinoline quinone (PQQ), otherwise known as methoxatin, is a water-soluble, redox-cycling orthoquinone that was initially isolated from cultures of methylotropic bacteria. It has been found to be a cofactor of some bacterial alcohol dehydrogenases, and is present in many animal tissues. It may be a novel vitamin because it has been shown to be essential for normal growth and development. The redox-cycling ability of PQQ enables it to scavenge or generate superoxide. When fed to animals as a supplement, PQQ prevents oxidative changes that would ordinarily occur. It has been reported to inhibit glutamate decarboxylase activity and protect against N-methyl-D-aspartate (NMDA) receptor-mediated neurotoxicity in the brain. It appears that in the whole animal, however, PQQ does not cross the blood-brain barrier. Furthermore, it increases nerve growth factor (NGF) synthesis in mouse astroglial cells, but has to be bound to glycine to penetrate and exert this effect in whole brain. It may therefore be regarded as a "Janus faced" molecule, with its potential for a therapeutic role in the brain still in question. | Yes |
Nexus Amino Acids & Electrolyte Powder – Grape Xplosion
Nexus Electrolyte Powder & Amino Acids. This flavour is guaranteed to make your mouth water with an explosion of sweet and sour grape candy dancing on your tastebuds with every sip. Nexie and his A-Team of mixologists have worked hard to develop an essential ammo flavour that replicates the sensation of snacking down on those fruity, tangy sweets.
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ALSO CONTAINS: SOLUBLE FIBRE, FOOD ACIDS (CITRIC ACID, TARTARIC ACID), ANTICAKING AGENT (SILICONE DIOXIDE, TRICALCIUM PHOSPHATE) SWEETENERS (SUCRALOSE, ACESULFAME POTASSIUM) COLOURS (BRILLIANT BLUE).
STORAGE: STORE IN A COOL, DRY ENVIRONMENT BELOW 25°C.
ELECTROLYTES: On top of EAA’s and BCAA’s we have added Electrolytes and 1g of Glutamine for ultimate performance during your training sessions.
Nexus Electrolyte Powder Nutritional Info
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Nexus Health Supplements Are Packed With High Quality Essential Nutrients And Minerals. Crafted In A Perfect Combination With Delicious Sugar Free Ingredients That Both Taste Amazing And Provides You And Your Body With The Constituents To Repair, Rebuild And Revitalise Daily.
Nexus | Health Supplements
Nexus Sports Nutrition Pty Ltd is one of Australia’s original sport supplement brands. Nexus Sports Nutrition Pty Ltd started from humble beginnings, from a garage, two young gym enthusiasts frustrated with the industries poor standard of honesty, transparency and international domination decided it was time to make a change.
Nexus Sports Nutrition Pty Ltd is Led by our 6 core values:
Thank you for your ongoing support from the entire team ❤️
Unlock the Power of Nexus Amino Acids and Electrolyte Powder in Australia: Revitalize Your Body with Convenient Sugar-Free Energy Drinks
In the fast-paced world we live in, maintaining optimal health and hydration is crucial for our overall well-being. However, achieving this balance can be challenging amidst our busy schedules and demanding lifestyles. Luckily, the Holistic Health store brings you an innovative solution – Nexus Amino Acids and Electrolyte Powder – a game-changer that can rejuvenate your body and keep you energized throughout the day. Dive into the world of health benefits these potent supplements offer, as well as the delightful sugar-free energy drink flavors that will make hydration a pleasure.
Understanding Nexus Amino Acids & Electrolyte Powder:
Nexus Amino Acids and Electrolyte Powder are formulated to provide your body with essential nutrients that play a vital role in maintaining proper bodily functions. These powdered supplements are thoughtfully crafted, drawing on the knowledge of experts in nutrition and wellness. They consist of a potent combination of amino acids and mineral electrolytes, making them an excellent choice for individuals seeking to enhance their health and well-being.
The Health Benefits of Regular Hydration with Mineral Electrolytes:
Electrolytes are essential minerals, such as sodium, potassium, calcium, and magnesium, that carry an electric charge and play a crucial role in maintaining fluid balance within our cells and throughout the body. When we sweat or lose fluids due to physical activity, illness, or hot weather, we deplete these electrolytes, potentially leading to dehydration and fatigue.
Regular hydration with mineral electrolytes can offer several significant health benefits:
1. Improved Hydration: Electrolyte-rich beverages can help replenish the lost minerals and fluids in the body, preventing dehydration and its associated symptoms like dizziness, weakness and chronic fatigue.
2. Enhanced Physical Performance: Maintaining the proper balance of electrolytes is essential for optimal muscle function. Proper hydration can improve exercise performance and endurance, making it an excellent choice for athletes and fitness enthusiasts.
3. Balanced Blood Pressure: Electrolytes like potassium and calcium play a role in regulating blood pressure. By consuming drinks with mineral electrolytes, you can support a healthy cardiovascular system and stable blood pressure.
4. Prevention of Muscle Cramps: Dehydration and electrolyte imbalances can lead to painful muscle cramps. Regularly consuming electrolyte-rich beverages can help minimize the risk of muscle spasms and cramps.
5. Support for Nerve Function: Electrolytes are essential in nerve impulses, heavily contributing to proper nerve function and communication throughout the body. Maintaining electrolytes for optimal homeostatic regulation you can enhance neuronal transduction and excitability. Improving both physical and cognitive performance with far less fatigue.
Harnessing the Health Benefits of a Broad Range of Amino Acids
Amino acids are the building blocks of proteins and are involved in various bodily processes, such as muscle repair, immune function, and hormone regulation. They are categorized as essential (obtained through diet) and non-essential (produced by the body).
Some health benefits of consuming a broad range of amino acids include:
1. Muscle Repair and Growth: Amino acids, especially branched-chain amino acids (BCAAs), are crucial for muscle recovery after physical activity and support muscle growth.
2. Immune System Support: Certain amino acids play a role in supporting immune function, helping the body defend against infections and illnesses.
3. Mood Regulation: Amino acids are involved in neurotransmitter production, influencing mood and emotional well-being.
4. Cognitive Function: Amino acids can contribute to improved cognitive function and mental clarity.
5. Digestive Health: Some amino acids support the integrity of the gut lining, promoting digestive health.
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Embrace the power of Nexus Amino Acids and Electrolyte Powder and transform your hydration routine into a rejuvenating experience. Discover the numerous health benefits of regular hydration with mineral electrolytes and the synergistic effects of a broad range of amino acids. Elevate your energy levels with sugar-free energy drinks in delightful flavors, all available conveniently online at the Holistic Health store.
Disclaimer: Before introducing any new supplement into your diet, it is essential to consult with a healthcare professional, especially if you have underlying health conditions or are pregnant or nursing.
Unlock Your Athletic Potential with Nexus: The Ultimate Sports Nutrition Solution
In the realm of sports and fitness, athletes are constantly seeking an edge to maximize their performance. Fueling the body with the right nutrients and supplements plays a crucial role in achieving peak athletic potential. Enter Nexus, the revolutionary sports nutrition solution designed to enhance your performance, boost recovery, and optimize your overall well-being. Packed with essential electrolytes and amino acids, Nexus is the game-changer you’ve been waiting for. Let’s delve into the world of Nexus and discover how it can power up your athletic journey.
The Nexus Advantage: Electrolytes & Amino Acids
Nexus harnesses the power of electrolytes and amino acids to provide athletes with a comprehensive performance-boosting formula. Electrolytes are minerals that play a crucial role in maintaining proper hydration and aiding muscle function. During intense physical activity, the body loses electrolytes through sweat, which can lead to fatigue, muscle cramps, and decreased performance. Nexus replenishes these essential electrolytes, such as sodium, potassium, and magnesium, to optimize hydration, prevent dehydration, and enhance endurance.
Both Electrolytes & Amino Acids
In addition to electrolytes, Nexus also delivers a potent dose of amino acids. Amino acids are the building blocks of proteins, which are vital for muscle repair and growth. Nexus provides a balanced blend of branched-chain amino acids (BCAAs) and essential amino acids (EAAs) to support muscle recovery, reduce muscle soreness, and improve post-workout repair processes. These amino acids promote protein synthesis, enhancing muscle strength and endurance, while also reducing the risk of muscle breakdown.
Nexus in Action: Boosting Performance & Recovery
Whether you’re a professional athlete or a dedicated fitness enthusiast, Nexus is your ultimate companion on the road to success. By replenishing electrolytes and delivering essential amino acids, Nexus optimizes your performance and accelerates recovery, allowing you to push your limits and achieve new heights.
During intense workouts or competitions, maintaining proper hydration is crucial. Nexus ensures you stay hydrated by restoring electrolyte balance. Electrolytes like sodium and potassium help regulate fluid balance, improve muscle contractions, and prevent cramps. With Nexus, you’ll experience increased endurance, reduced fatigue, and enhanced mental focus, giving you the competitive edge to outperform your rivals.
Post Exercise Recovery
Furthermore, Nexus provides the perfect post-workout recovery fuel. Its amino acid-rich formula promotes muscle repair and reduces muscle soreness, allowing you to bounce back faster and train harder. The BCAAs in Nexus stimulate protein synthesis, helping rebuild muscle tissue and preventing muscle breakdown. EAAs complement this process by providing the necessary building blocks for recovery and growth. With Nexus, you’ll experience shorter recovery times, increased muscle strength, and improved overall athletic performance.
The Science behind Nexus: Quality & Safety
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Moreover, Nexus is free from artificial additives, fillers, and banned substances, making it a safe and trustworthy choice for athletes in all disciplines. With Nexus, you can focus on your training, knowing that you’re fueling your body with a product that is both scientifically backed and safe for consumption.
Nexus Electrolyte Powder Conclusion
In the world of sports nutrition, Nexus stands out as the ultimate solution for athletes who seek to unleash their true potential. By replenishing electrolytes and delivering essential amino acids, Nexus provides the foundation for improved performance, faster recovery, and overall athletic success. Don’t settle for mediocrity. | Yes |
Blackmores Evening Primrose Oil 1000 is a rich, natural source of gamma-linolenic acid (GLA) and linoleic aci0d (LA). These important omega-6 fatty acids can only be produced in the body in small amounts and must largely be obtained from the diet.
This supplement is beneficial for the health and wellbeing of women. Omega-6 fatty acids and substances made from them, are components of nerve cells, all cell membranes and hormone-like substances known as prostaglandins.
Prostaglandins have multiple local hormone-like actions, which include regulation of tissue inflammation. Conditions that involve inflammation, such as eczema, may benefit from supplementation with omega-6 fatty acids. Low levels of GLA have been found in women with premenstrual syndrome (PMS).
Essential fatty acid deficiency can lead to an excess of the female hormone prolactin which is responsible for many of the symptoms of PMS. Supplementing with EPO increases a prostaglandin known as PGE1, which may help in women's health and wellbeing. | Yes |
Due to the fact that it offers over 600 health benefits, turmeric has been valued and commonly used for millennia. Its properties are mostly a result of its active ingredient, curcumin, which offers a wide plethora of healing properties.
Yet, you probably weren’t aware of its brain-regenerative properties, were you?
Here are the most important benefits of this miraculous spice:
- It prevents and treats cancer
- It reduces the risk of heart diseases
- It has powerful anti-inflammatory and antioxidant properties, which prevent free radical damage
- It increases the serotonin and dopamine levels, which are neurotransmitters that prevent depression
- It delays aging and fights age-related conditions
- It raises the levels of the brain hormone BDNF, which triggers the growth of new neurons and fights degenerative processes in the brain
However, researchers have often overlooked one fat-soluble compound in turmeric, called aromatic-turmerone.
German scientists have analyzed its effects on neural stem cells and found that it increased the number of neutral stem cells by 80 percent, indicating that it has a healing effect.
When rats were exposed to it, it managed to create healthy new brain cells and increased the size of the subventricular zone and the hippocampus.
Ar-turmerone is a potent regenerative which helps NSCs in brain regeneration and is helpful in the treatment of degenerative diseases such as Alzheimer`s or stroke.
It supports the proliferation of the stem cell, and distinguishes between stems cells and neurons, which is the main goal of regenerative medicine.
Therefore, to reap all the benefits of this amazing spice, and enjoy its full potential, you should use the whole turmeric, instead of just taking a turmeric extract. | Yes |
Celebrity Makeup News and Blogs:
Mareannah asks…I don’t understand why Bare Minerals comes off so easily. Is this true of all mineral products?
The Beauty Brains respond:
It depends on your definition of “mineral makeup.”
The make up of mineral makeup
True mineral makeup (makeup that ONLY contains true mineral ingredients) must come in powder form because there are no liquid minerals. Therefore, these products are limited to ingredients such as talc, calcium carbonate, mica, iron oxides, and so on. While these ingredients do a good job of gently covering the skin they do have a couple of significant drawbacks: They only offer a limited color palette and they have poor adhesion to skin compared to other forms of make up which include oil and other binders. The latter is the reason you experience this problem with some mineral makeup products.
It’s also important to note that some products call themselves mineral makeup even though they contain non-mineral ingredients. If mineral purity is important to you, be sure to read the label very carefully to make sure only minerals are listed. But if long lasting coverage is more important to you, then look for non-mineral ingredients like oils that help the powder stick to your skin.
Image credit: http://farm7.staticflickr.com | Yes |
- Air is present everywhere on earth.
- We cannot see air, but we feel its presence in many ways.
- You notice it when the leaves of the trees rustle or the clothes hanging on a clothes-line sway. Pages of an open book begin fluttering when the fan is switched on. The moving air makes it possible for you to fly your kite.
- Winnowing is more effective in moving air.
- Air is present as a thick blanket surrounding the surface of the earth.
- The layer of gases around the earth is called as
- The atmosphere is dense at the surface of the earth and becomes thinner as one moves up.
Layers of Atmosphere
The atmosphere is divided into five layers. It is thickest near the surface and thins out with height until it eventually merges with space.
1. The troposphere is the first layer above the surface and contains half of the Earth’s atmosphere. Weather occurs in this layer.
2. Many jet aircrafts fly in the stratosphere because it is very stable. Also, the ozone layer absorbs harmful rays from the Sun.
3. Meteors or rock fragments burn up in the mesosphere.
4. The thermosphere is a layer with auroras. It is also where the space shuttle orbits.
5. The atmosphere merges into space in the extremely thin exosphere. This is the upper limit of our atmosphere.
2. IMPORTANCE OF AIR
- Air is essential for all living beings. It supports life on earth.
- Air is utilised by all the living organisms like plants, animals and microorganisms.
- Air cannot be seen but is felt when it moves.
- The movement of air is called breeze or wind depending on its velocity or speed.
- Air fills in the empty space available everywhere.
- We all breathe in air. Breathing is an essential part of respiration. We breathe in oxygen rich air and breathe out carbon dioxide rich air.
3. COMPONENTS OF AIR
Air contains mostly nitrogen and oxygen. Nitrogen occupies 78% of the air. Oxygen occupies 21% of the air. 1% of the air is made up of carbon dioxide, other gases, water vapour, dust particles etc.
- It is a lightest colourless, odourless gas. It generally occurs in its diatomic form N2.
- Nitrogen is used to control combustion.
- Nitrogen is used by plants and animals to synthesise proteins in the body.
- Nitrogen cannot be directly used by plants or animals. It has to be fixed into its nitrate or nitrite
- Nitrogen is used to manufacture fertilisers to increase soil fertility.
- Nitrogen is used to manufacture ammonia used for in many industries.
- Nitrogen oxidation of stored food in packets.
- It is a chemical element in the form of gas. Mostly it is diatomic, made up of two atoms. O2is the molecular oxygen.
- It is the active part of the air and one-fifth of total volume of air is oxygen.
- Oxygen is taken directly from the air by organisms living on land for respiration.
- Oxygen helps in oxidising the food eaten by organisms to release energy.
- Aquatic organisms take in oxygen dissolved in water.
- Oxygen is required for combustion and is used for welding purposes.
- Oxygen in the form of ozone helps in protection of living organisms from dangerous UV rays coming out from the sun.
- Liquid Oxygen is used as a fuel in rockets.
- Oxygen stored in the cylinders is used to provide artificial respiration to patients in the hospital. Oxygen mask is given to patient suffering from respiratory problems.
- Mountaineers, astronaut and sea divers carry oxygen cylinder with them but aeroplane passengers do not carry oxygen cylinder.
- Mountaineers carry Oxygen cylinder with them, while climbing mountains because air pressure is low at higher altitude.
Earthworms come out of the soil, only during heavy rains
Most of the small organisms like earth worms, rodents live inside the soil. They usually live in burrows and holes in the soil. These burrows also make spaces available for air to move in and out of the soil. However, when it rains heavily, water fills up all the spaces occupied by the air in the soil. In this situation, animals living in the soil have to come out for respiration.
III. Carbon Dioxide
- It is the gas which is made up of one carbon atom combining with two atoms of oxygen.
- Combustion of coal, fossil fuels and hydrocarbons, etc release carbon dioxide.
- CO2is used by plants in synthesising their food by the process of photosynthesis.
- CO2 is used in fire extinguishers.
- CO2 is used in storing soft drinks.
We feel suffocation in a room having burning substance due to accumulation of carbon dioxide gas and less availability of oxygen gas.
Activity to show presence of oxygen, carbon dioxide and nitrogen in air:
For this, take a candle, a glass tumbler and a pan which is filled with some water. Keep the candle upright in the pan and light the candle. Now cover the candle with the glass tumbler. It is observed that the candle extinguishes after some time.
This happens because oxygen in the air inside the glass tumbler is utilised in burning the candle. All the oxygen gets converted into carbon dioxide. Carbon dioxide does not support burning and hence candle stops burning.
Once the candle stops burning, some amount of water is sucked inside the tumbler. This happens because the volume of cabron dioxide is less than the volume of oxygen which was displaced.
It is also seen that a lot of air is still inside the tumbler. A major portion of this air is nothing but nitrogen. Nitrogen too does not support burning.
IV. Inert Gases
- These are also called as noble gases. They occupy a negligible percentage in air.
- Argon is used to fill the bulbs to prevent their filament.
- Helium is used in providing low temperatures.
- Neon is used to fill special bulbs called as neon signs.
- Radon is used in treating cancer patients.
V. Water Vapour
- It is a form of water present as gas in the air.
- Amount of water vapour in the air varies with sun’s heat.
- Hot sun can evaporate more amount of water and convert it into water vapour.
- It helps in the formation of clouds which later can come down as rain.Dust and Smoke
VI. Dust and Smoke
- Air contains some amount of dust and smoke in it.
- Tiny shining particles moving in beam of sunlight is dust particle in air moving in random
- Dust and smoke are contributed by vehicles and industries releasing them.
- These are harmful to human beings and can cause many respiratory diseases.
- The burning of fossil fuels produce harmful smoke in atmosphere to cause air pollution.
- poisonous gas and dust particles are present in polluted air.
- Finer hairs inside the nose filter the dust particle while inhaling the air.
- In industrial area concentration of dust particle is more due to release of gas and dust particle from chimney of factories .
- The nose and mouth of traffic police at crossing is covered with mask due to presence of high pollutants in air.
4. OXYGEN-CARBON DIOXIDE LEVELS
- Oxygen and carbon dioxide levels in the air are maintained by different processes like respiration and photosynthesis.
- Respiration involves utilization of oxygen from air by living organisms and releasing carbon dioxide into air. It occurs in all living organisms.
- Photosynthesis involves utilization of carbon dioxide from air and release of oxygen into the air.
- Carbon dioxide is replenished by the process of respiration and oxygen is replenished by the process of photosynthesis.
5. PROPERTIES OF AIR
- Air is transparent. Air is a transparent medium which allows light to pass through it. The objects are seen clearly through air.
- Air is colourless. It is not visible.
- Air can be felt when it moves fast. Moving air is called as wind.
- Air occupies space. Air is present everywhere. Air can be displaced by water.
- Air exerts pressure.
- Air can be compressed and filled into a container.
6. AIR IS NECESSARY FOR COMBUSTION – ACTIVITY
i) Take a glass trough and fill 1/3 of its volume with water.
ii) Add a spoonful of caustic soda (Sodium hydroxide) and few drops of coloured ink to the contents of the trough.
iii) Place a wooden slab or stone in the trough and place a lighted candle on it as shown in the figure.
iv) Invert a wide mouthed glass jar over the burning candle. The candle is put off within few seconds. At the same time the coloured water in the glass jar raises.
v) The supporter of combustion i.e., oxygen in the air, contained in the glass jar was exhausted and carbon dioxide is released in its Hence oxygen in the air is useful for combustion.
vi) The carbon dioxide so formed is absorbed by caustic soda solution. The nitrogen which is still available in air does not give support for burning.
vii) As vacuum is created in the glass jar, the coloured water raises in the trough.
viii) However if the glass jar is not placed in an inverted position over the burning candle, the candle goes on burning forever, as air is available continuously.
ix) Hence, we can say that oxygen in air is necessary for burning.
7. OTHER USES OF AIR
- Air is used to rotate wind mills, which can lift water.
- Wind energy is a renewable form of energy.
- Air is also used to rotate wind mills which can generate electrical energy by aerogenerators.
- Air is used in sail boats.
- Air helps in the scattering of seeds and pollens of plants. (pollination).
- Air helps in the movements of sailing yachts, gliders, parachutes and aeroplanes. | Yes |
1997/1/1· The most important mineral of Sr is celestite (SrSO 4), and strontianite (SrCO 3) is also mined. The largest producers are Mexico, Spain, Turkey and the UK, and the world production of these two minerals in 1985 was 10 5 tonnes.
For example, it is revealed that acidosis decreases potassium secretion in the distal renal tubule directly by effect on potassium secretory channels and indirectly by increasing ammonia production. The clinical consequences of the physiological relation between acid-base and potassium homeostasis are addressed under three headings: Hyperkalemia in Acidosis; Hypokalemia with Alkalosis; and
Especially, phosphorus, potassium, calcium and other micronutrients. (I do understand that with time, and with deep rooted species, the soil will gradually correct itself, as plants bring those minerals from the bed rock parenting the soil.
1994/8/13· Introduction Results from many studies suggest a role for minerals in blood pressure regulation. Sodium may increase blood pressure,1 whereas the reverse has been reported for potassium and magnesium.2,3 Several studies have shown a stronger relation of the sodium to potassium ratio with blood pressure than sodium or potassium alone.*RF 4-6* Hence dietary measures to reduce …
In estimating calcium requirements, most committees have used either a factorial approach, where calculations of skeletal accretion and turnover rates are coined with typical values for calcium absorption and excretion, or a variety of methods based on(15, 16)
Important electrolytes are lost in sweat during exercise, including sodium and potassium. The concentration can also be affected by rapid loss of fluids, such as after a bout of diarrhea or vomiting.
A freshwater mountain stream in Rocky Mountain National Park. JML Visuals. Reproduced by permission. Most of the dissolved, inorganic chemicals in freshwater occur as ions. The most important of the positively charged ions (or ions) in typical freshwaters are calcium (Ca 2+), magnesium (Mg 2+), sodium (Na +), ammonium (NH + 4), and hydrogen (H +).
Specific nutrients such as nitrogen (N), phosphorus (P), and potassium (K) are the three most important soil supplied nutrients and are called essential nutrients. There are several other nutrients important for plant growth such as calcium (Ca), magnesium (Mg
Potassium Needed for proper fluid balance, nerve transmission, and muscle contraction Meats, milk, fresh fruits and vegetables, whole grains, legumes Calcium Important for healthy bones and teeth; helps muscles relax and contract; important in nerve
COMPLETE FORMULA: Provides 600 mg of Elemental Calcium from Two Different Sources, 200 mg of Natural Magnesium Glycinate, 1000 IU of Vitamin D3, and 7 Other Important Vitamins & Minerals. POWERFUL BENEFITS: Reduces the Risk of Osteoporosis in Men & Women Over 40 ‚ Promotes Bone Density ‚ Supports Joint Health ‚ Restores Wellness ‚ Makes a Perfect Prenatal Supplement for a …
Calcium, magnesium, potassium, chloride and sodium are some of the most common electrolytes. Optimal health requires a balance of electrolytes in your blood and tissues. Your kidneys play an important role in maintaining this balance. Inadequate levels of
Calcium occurs in nature as various forms of the metal, such as calcium oxide and calcium carbonate, and many underground water sources contain abundant amounts of calcium. Calcium is actually the fifth most abundant element that occurs in the human body, …
2019/8/21· Major minerals are vital for optimal health. Read on to learn about their important functions and how you can include them in your diet. Phosphorus is the second-most abundant mineral in the body. It promotes healthy formation of bones and teeth. Around 85 percent
Adequate calcium intake is especially important for teens because of the future risk of osteoporosis. According to the International Osteoporosis Foundation, calcium is the main mineral involved in the formation and strengthening of bones, and calcium requirements are high during teenage years, since it''s a period during which there are major growth spurts.
2018/1/4· Minerals such as calcium, zinc, iron, and potassium in your body are very important for body functions. Magnetic field stimulation of the body requires adequate and balanced amounts of minerals. Minerals may be supplied by supplements but the best, most naturally usable sources of minerals are from foods.
Buy Ultima Replenisher Electrolyte Hydration Powder, Variety Pack, 20 Count Stickpacks - Sugar Free, 0 Calories, 0 Carbs - Gluten-Free, Keto, Non-GMO with Magnesium, Potassium, Calcium on FREE SHIPPING on qualified orders
Calcium has several important functions. These include: helping build strong bones and teeth regulating muscle contractions, including your heartbeat making sure blood clots normally A lack of calcium could lead to a condition called rickets in children, and osteomalacia or osteoporosis in later life.
Specifiions for sodium, potassium and calcium ferrocyanide have been defined in the EU in Commission Regulation (EU) No 231/2012 and also by JECFA (). The purity is specified to be not less than 99% for sodium, potassium and calcium ferrocyanide.
2018/6/19· The body doesn’t manufacture essential minerals, such as calcium, magnesium, potassium, chromium, copper, and iron. Instead, the minerals come from diet. Most people can meet recommended intakes of dietary minerals by eating a healthy diet rich
2017/12/12· The seven macrominerals– calcium, chloride, magnesium, phosphorus, potassium, sodium and sulphur–now share the research spotlight with a longer list of essential trace minerals. These are needed only in minute amounts, but their absence results in many disease conditions.
2011/12/9· There are two basic groups of minerals: macrominerals and trace minerals. Macrominerals are required in larger amounts than the trace minerals and are found in greater amounts in a dog''s body. Macrominerals include calcium, phosphorus, magnesium, sodium, chloride, potassium and sulfur.
Calcium demand for a cow starting lactation is almost double compared when she was not lactating and pregnant. Normal blood plasma Ca concentration is tightly regulated and generally kept between 8.5 to 10 mg/dl (2.1 to 2.5 mM; Cahn and Line, 2005). Two to
2020/4/2· Important information You should not use potassium citrate if you have kidney failure, a urinary tract infection, uncontrolled diabetes, a peptic ulcer in your stomach, Addison''s disease, severe burns or other tissue injury, if you are dehydrated, if you take certain diuretics (water pills), or if you have high levels of potassium in your blood (hyperkalemia).
In compounds of potassium (where known), the most common oxidation nuers of potassium are: 1. Hydrides The term hydride is used to indie compounds of the type M x H y and not necessarily to indie that any compounds listed behave as hydrides chemically.
There are so many important minerals beyond the obvious two—iron and calcium— that help your body function efficiently and thrive. Ask Keri: Everyone’s always talking about which vitamins are most important for health, but what about minerals? Keri Says: There are so many important minerals beyond the obvious two—iron and calcium— that help your body function efficiently and thrive.
Potassium, sodium, and calcium are electrolytes, or salts that help conduct electric current in the body. Chemically, electrolytes are substances that become ions in …
Sources of minerals: how to get potassium, calcium and iron in your diet Expert advice on the best sources of minerals and why they''re important. Medically reviewed by Dr Roger Henderson and based
The most abundant mineral in the body, Calcium is the second most important mineral for bodybuilders. There are several reasons for this. Bodybuilders may have difficulty maintaining the needed 1:1 calcium to phosphorus ratio. | Yes |
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If you are using a TIG welder, be sure to use the correct tungsten. A pure or thoriated tungsten electrode works best welding with AC current. Electrodes are identified by colored bands: green for pure tungsten, red for 2 percent thorium, and orange for 2 percent cerium, which is better suited to DC welding. We used a pure (green) electrode. | Yes |
The truth about solid state batteries – how close are they? Like About Share 0 views 0% 0 0 The truth about the solid state battery – how close are they? Get Surfshark VPN at https://surfshark.deals/undecided Enter promo code UNDECIDED for 83% off … Bookmark(0) Please login to bookmark Username or Email Address Password Remember Me No account yet? Register From: admin Date: November 24, 2020 Graphene batteries electric vehicles graphene graphene battery john b goodenough solid state battery john goodenough john goodenough new solid state battery john goodenough solid state battery lithium battery lithium ion batteries nissan panasonic solid state solid state batteries 2020 solid state battery solid state battery explained solid state battery goodenough solid state battery technology solid state battery tesla tesla the truth about undecided with matt ferrell Related videos 50K 01:34 93% Andrea Ferrari about graphene and optoelectronics 117K 04:02 91% ‘Hot’ Qubits Crack a Major Quantum Computing Challenge 85K 07:31 98% The Truth About Graphene Coatings | Ethos Car Care 69K 04:07 95% CARBYNE LAC Explained in 4 Min – Stronger than Graphene 76K 08:09 86% HEAD Graphene 360+ Gravity Tour v Pro Tennis Racket club level player review by pdhsports.com 106K 05:58 89% Top 50 Interesting Facts about Graphene 88K 10:49 93% Graphene And Graphite Mining 98K 10:35 85% Exploring solar panel efficiency breakthroughs in 2020 Show more related videos Leave a Reply Cancel replyYour email address will not be published. Required fields are marked *CommentName * Email * Website Save my name, email, and website in this browser for the next time I comment. | Yes |
Redox active metals in neurodegenerative diseases
Karla Acevedo, Shashank Masaldan, Carlos M Opazo, Ashley I Bush
JBIC Journal of Biological Inorganic Chemistry | Springer Science and Business Media LLC | Published : 2019
Copper (Cu) and iron (Fe) are redox active metals essential for the regulation of cellular pathways that are fundamental for brain function, including neurotransmitter synthesis and release, neurotransmission, and protein turnover. Cu and Fe are tightly regulated by sophisticated homeostatic systems that tune the levels and localization of these redox active metals. The regulation of Cu and Fe necessitates their coordination to small organic molecules and metal chaperone proteins that restrict their reactions to specific protein centres, where Cu and Fe cycle between reduced (Fe2+, Cu+) and oxidised states (Fe3+, Cu2+). Perturbation of this regulation is evident in the brain affected by neur..View full abstract
The Florey Institute of Neuroscience and Mental Health acknowledges the strong support from the Victorian Government and in particular the funding from the Operational Infrastructure Support Grant. This work was supported by the Australian Research Council (AIB, CO), the National Health and Medical Research Council and the CRC for Mental Health (AIB). Figures 1 and 2 were compiled using images from Servier Medical art. | Yes |
Our 70% ethyl alcohol antiseptic hand sanitizer is professional-grade with a fragrance-free formulation, produced in FDA compliant facilities. IMG’s products are 100% manufactured in the United States by American hands. Our raw materials are sourced from multiple U.S. based suppliers and have been ordered in advance ensuring that our supply chain and production capabilities remain uninterrupted.
MADE IN U.S.A. // All Iconic Medical Group Advanced Hand Sanitizer is made in the U.S.A. and our products are shipped directly from our U.S. fulfillment centers. We source all of our raw materials from U.S. based suppliers and our all of our products are assembled by American hands.
SHELF LIFE // This product has a recommended shelf life of 36 months from date of manufacture.
HANDLING INSTRUCTIONS // Avoid contact with eyes. In case of contact with eyes, rinse immediately with plenty of water (for at least 10 minutes) and seek medical advice if condition persists.
APPLICATIONS FOR USE // Apply a small amount to palm. Gently rub hands together, covering hands with product until dry.
INGREDIENTS // Ethyl Alcohol, Water, Carbomer, Aloe Barbadensis Leaf Juice, Triethanolamine, Glycerin, Tocopheryl Acetate | Yes |
We, Wuxi Baichuan Chemical Industrial Co. Limited, are one of the recognized Manufacturers of Trioctyl Trimellitate (TOTM) and more products. Established in the year 2002, we are located at Jiangyin, China. Read More...
|No. of Employees:||501 to 1000 People|
|Turnover:||More than US$ 100 Mn|
We are currently at an advanced stage of a project that could see the establishment of a world-class crude refinery in south africa's eastern cape ...Za Petrochem
Our TBAc brand of tertiary butyl acetate is a unique non-HAP, VOC-exempt* organic solvent with versatile performance and negligible photochemical ...Guangdong Derong Chemical Co. Limited
Index name Index Test method Appearance Colorless transparent liquid Visual tert-butyl acetate Original CtraficatePurity% (m/m) 99.5 ...Zibo Landi-oil Chemicals Sales Co. Limited
sending enquiry .... | Yes |
Isoadditive solutions for the BOPP film market
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ISOLAGO is your partner for Masterbatch Solutions in a changing world. | Yes |
Mitsubishi Chemical Corporation (MCC; Headquarters: Chiyoda-ku, Tokyo; Chairman: Masayuki Waga), as part of an initiative to help achieve a circular economy and the Sustainable Development Goals (SDGs), has developed a polystyrene sheet (heat resistant OPS®) with higher recycling potential, and implemented a mass production system.
OPS® is light but strong and offers excellent transparency and moldability. With these properties, it is widely used in food packaging and containers, including the lids of bento boxes. During the OPS® molding process, material scraps result from the cutting of the sheet, which is why efforts have been made by packaging manufacturers to recycle it as a raw material. However, the conventional heat-resistant OPS®, which can be used in a microwave, is difficult to re-foil because the melting and mixing of the waste materials presents problems that make it unsuitable for recycling. .
In view of customer awareness of this issue, MCC has partnered with a raw material manufacturer and jointly developed a heat resistant OPS® that can be recycled during the customer’s manufacturing process. Sampling work is already underway with several customers; some of which have even decided to use OPS®.
In accordance with KAITEKI Vision 30, the core medium and long term management strategy of the Mitsubishi Chemical Holdings Corporation (MCHC) group, MCC positions the promotion of a circular economy as a key element for the realization of KAITEKI *. MCC believes that recycling products and other materials is a key initiative in this direction. Going forward, MCC aims to contribute to the achievement of the SDGs and the achievement of a sustainable society by implementing product design that is easily recyclable by MCC as well as its customers.
“This reflects the original concept of the MCHC Group to achieve the ‘sustainable well-being of people, society and our planet Earth’.
The content is as of the date of presentation. Please note that the content can be changed later.
Mitsubishi Chemical Corporation published this content on September 17, 2021 and is solely responsible for the information it contains. Distributed by Public, unedited and unmodified, on September 17, 2021 01:41:06 AM UTC. | Yes |
Open Access Journals gaining more Readers and Citations
700 Journals and 15,000,000 Readers Each Journal is getting 25,000+ Readers
|Wangila Tsikhungu Phanice|
|University of Kabianga, Kenya|
|ScientificTracks Abstracts: Mod Chem Appl|
|Heavy metals presence in the environment is of great ecological significance due to their toxicity at certain concentrations, translocation and nonbiodegradability which is responsible for their accumulation in the biosphere. Pb and Cd concentration of soil and reed plant of Busia and Lugari regions of Western Kenya was investigated with an aim of establishing the level of accumulation of the Cd and Pb metals.The level of Cd was generally high in soil samples compared to Pb. The uptake of Pb by reeds within this region is comparable, with TF of 1.4 and 0.205 for Cyperus papyrus and Typha latifolia reeds respectively.|
Wangila Tsikhungu Phanice is lecturer of chemistry and Head, Physical science department, Chemistry, University of Kabianga,Kenya from 2009 upto present .Currently she is doing her Ph.D in Analytical-Environmental Chemistry from Egerton University, Kenya. Wangila Tsikhungu Phanice has obtained a Masters degree in Chemistry from Egerton University Kenya.Her research interest includes Analytical-Environmental Systems Toxicology, Food and Indigenous Knowledge Heavy and Trace Metals in Environmental Systems with a view of Analytical Chemistry.
|PDF | HTML| | Yes |
You are currently browsing the category archive for the ‘Scrombrotoxin’ category.
Food safety infosheet highlights:
– 10 patrons of EVOO in Raleigh stricken with possible histamine-induced illness
– Certain types of fish, including anchovies, tuna and mahi mahi, are at risk for scombrotoxin/ histamine contamination
– Cooking, canning and freezing will not reduce the toxic effects of scombrotoxin. Buy fish from reputable sources who demonstrate proper handling.
Click here to download the food safety infosheet. | Yes |
US 6348515 B1
Foam blowing agents blends of HFC-134a and a pentane selected from n-pentane, i-pentane and i-pentane/cyclopentane are provided, as are polyol premixes and polyurethane foam compositions containing such blends.
1. A foam blowing agent composition comprising 1,1,1,2-tetrafluoroethane, i-pentane and cyclopentane.
2. The composition of
3. A foam premix composition comprising a polyol and the foam blowing agent composition of
4. A polyurethane foam composition comprising an isocyanate, a polyol and the foam blowing agent composition of
5. A foam blowing agent composition comprising (a) about 5 to 30 mole % of 1,1,1,2-tetrafluoroethane and (b) about 95 to 70 mole % of a pentane selected from the group consisting of n-pentane and an i-pentane/cyclopentane blend.
6. The composition of
7. The composition of
8. A foam premix composition comprising a polyol and the foam blowing agent composition of
9. A polyurethane foam composition comprising an isocyanate, a polyol and the foam blowing agent composition of
This invention relates to foam blowing agent blends of (a) 1,1,1,2-tetrafluoroethane (“HFC-134a” or “134a”) with (b) n-pentane (n-C5), i-pentane (i-C5) or a mixture of i-pentane and cyclopentane (i-C5/c-C5) and to polyol premixes and polyurethane foam compositions containing such blends.
Until now, the leading polyurethane foam blowing agent has been 1,1-dichloro-1-fluoroethane (“141b”), in order to meet the market place requirements for energy, fire performance and cost. At the same time, however, 141b has a high ozone depletion potential (“ODP”) of about 0.1. Thus, many foam manufacturers are now investigating the zero ODP pentanes as candidates to replace 141b, as noted for example in an article on “Hydrocarbon Blown Rigid Polyurethane Foam for the Boardstock Industry—A novel Approach” by R. E. Berrier et al which appeared in Polyurethanes Expo '98, Sep. 17-20, 1998. They too, however, have property shortcomings for use in foam, such as high k-factor performance in foam (thus giving foams with poor thermal insulating properties). They are also flammable.
HFC-134a has also been disclosed, as in U.S. Pat. No. 5,439,947, for use as a foam blowing agent. When used alone, it has certain disadvantages such as a high global warming potential (“GWP”) of about 1300 and limited solubility in foam formulation components such as polyols and polymeric MDI (methane diphenyl diisocyanate).
It would therefore be useful to provide the industry with an alternative foam blowing agent which overcomes the deficiencies of 134a or the pentanes alone in terms of properties such as ODP, GWP, and k-factor performance.
Foam blowing agent compositions are provided, which compositions comprise (a) 134a and (b) a pentane selected from the group consisting of n-C5, i-C5 and i-C5/c-C5 (preferably as an equimolar mixture of i-C5 and c-C5), as well as foam premix compositions, which premix compositions comprise a polyol and the foregoing blowing agent blend, and polyurethane foam compositions, which foam compositions comprise an A-side containing an isocyanate and all or a portion of the foregoing blowing agent blend and a B-side containing a polyol and all or a portion of the foregoing blowing agent blend.
It has now been found that the foregoing blends of pentanes with HFC-134a overcome deficiencies associated with the use of either alone. Most important, as shown below, the addition of relatively small amounts of 134a has been found to lower the k-factor (and thus enhance the thermal insulating properties) of foams made with such blends relative to the use of the pentanes alone, especially at low temperatures, while still taking advantage of the low GWP properties of the pentanes (for example, cyclopentane has a GWP of 11 versus a GWP of 1300 for 134a alone). Other advantages include improved solubility in raw materials such as polyester polyols (especially for n-pentane and i-pentane) and less volatile organic compound (“VOC”) content than pure hydrocarbon since HFC-134a is not a VOC.
The unexpected improvement shown in the following examples in low temperature (0° C.) k-factor performance is particularly significant for many foam applications such as for refrigerators, freezers and cold storage facilities.
The preferred amount of 134a in the blends varies with the particular pentane or pentane mixture, as shown by the examples below, but is generally in the 5-30 mole % range.
In the premix compositions, the blowing agent blend is typically present in a concentration range of about 2-60 weight % (preferably 5-40 weight %), based on the weight of the polyol.
In the polyurethane foam compositions, the effective concentrations of the blends are typically about 0.1-25 weight % (preferably 0.5-15%) based on the weight of the total polyurethane foam formulation.
The pentane component and/or the 134a component of the blend can be added to the A-side or the B-side or a portion thereof distributed in each side. It is also possible to add the blowing agent composition as a third stream to the foam machine, wholly apart from the A- or B-side.
The other components of the premix and foam formulations may be those which are conventionally used, which components and their proportions are well known to those skilled in the art. For example, catalysts, fire retardants and surfactants are typical components of the B-side.
The practice of the invention is illustrated in more detail in the following non-limiting examples. The formulations used (all having an Iso Index of 300) each contained 170.51 parts M-489, a polymeric methane diphenyl diisocyanate available from Bayer Corporation; 100 parts PS2352, a polyester polyol having a hydroxyl number of 230-250 available from the Stepan Company; 0.19 part PC-5 and 0.33 part PC-46, which are, respectively, pentamethyldiethylenetriamine and potassium acetate in ethylene glycol, catalysts available from Air Products; 2.98 parts K-15, potassium octoate in dipropylene glycol, a catalyst available from Air Products; 2 parts B-8462, a polysiloxane-polyether copolymer surfactant available from Goldschmidt Chemical Corporation; 10 parts A-B-80, a tris(1-chloro-2-propyl)phosphate fire retardant available from Albright & Wilson Americas, Inc; and about 24-26 parts blowing agents, the exact amounts of which are more particularly set forth below; all parts are by weight.
The A-side component (isocyanate) was maintained at about 75-80° F. (about 24-27° C.). B-side premix components, containing polyol, surfactant, fire retardant, catalyst and blowing agent, were mixed and maintained at about 75-80° F. (about 24-27° C.). The blowing agent used is set forth in Tables I and II below.
In making the foam, the A and B sides were mixed at pressures above 2000 psi and dispensed into a mold pre-heated to 150° F. (about 66° C.). The mold was kept closed for a few minutes before releasing the foam. For free rise foam, a mixture of the A and B sides was dispensed into an open container and the foams were allowed to expand.
ASTM procedures were followed to measure (initial) k-factors (ASTM C518) of the resultant foams at ambient temperature (24° C.) and at 0° C. The results of the molded foam are shown in Tables III and IV:
For free rise foam, improvement of low temperature (0° C.) initial k-factor over pure pentane was observed with all blowing agent blends using 20 mole % 134a. | Yes |
It was a more innocent time – the early 1980s – a time when New Wave music filled the air and when blowing up pumpkins and setting things on fire in the desert was not a crime worthy of visit by officials from the Department of Homeland Security.
This was a good thing for my 17-year old brother, who was creative and a bit mischievous, and very, very smart. Think Bart Simpson with a 180 IQ.
He had long had an affinity for blowing things up and/or setting them on fire. He used to love to take a can of Lysol and my mother’s cigarette lighter, then spray the Lysol and light it on fire. Look kids! A do-it-yourself flamethrower! Did I mention he did this in the living room of a home furnished entirely in the 1970s, aka, pre-flame retardant?
His love of fire and explosions led to his love of chemistry. After all, chemistry is the science responsible for fireworks. And fireworks are awesome.
He was so good at chemistry his junior year that the teacher made him an assistant the following year. This, of course, gave him unfettered access to all the lab’s chemicals and, as it turns out, my brother had sticky fingers.*
He ‘borrowed’ some of said chemicals to augment his home chemistry set. One fall afternoon, he decided to add some stuff together in a copper tube and, in the words of the immortal Foghorn Leghorn, watch it fizz.
Fizz it did. Years later when I asked my brother about it, he said he knew something was very wrong because the tube got very hot. Hot is not a good thing when (a) you’re not expecting it, and (b) you’re a 17-year old kid mixing chemicals in your bedroom.
The resulting explosion sounded like a shotgun blast. My parents came running and found their son standing by his desk, blood running down his arm and a big chunk of the wall missing. They went into parental overdrive, which is to say they started yelling, pointing at things, screaming and running to find the car keys.
My 14-year old sister, clad in her mustard yellow and mold green band uniform, helped by running back and forth like a deranged chicken. She made this strange shrieking sound and, with the band uniform and its ridiculous hat, she looked like a very agitated nutcracker.
Being just 8-years old, I was pretty clueless about the whole thing. My brother held a rag to his hand, which covered up the bleeding, so I didn’t understand the enormity of what had just happened. However, I knew shit was getting real when my father propped my ghost white brother up against the laundry room door and my brother promptly fainted. Problem was, the laundry room door hadn’t been latched, so my brother fell backward to the floor, his skull making a sickening cracking sound as it hit the orange, yellow and brown linoleum. (Ah, the 1970s. What gifts you gave us.)
I don’t remember what happened next. Somehow my sister got to the football game, meaning she actually wore that hideous uniform in public. And we got my brother to the hospital, a stressful 40-minute drive from our house.
I watched as they used this big machine to pick copper shards out of my brother’s eyes. His hand was stitched up, his eyes were covered in gooey ointment and bandages, and all we went home.
His eyes recovered and his hand, save for a small scar, was fine. My parents promptly removed all contents from his room and put a permanent end to the bedroom laboratory, but it wasn’t long before he was back to making flame throwers with the Lysol can. And blowing things up in the desert.
My brother’s chemistry career was far from over. He just learned the value of using glass tubes instead of metal ones.
*UPDATE: My brother Jeff responds:
“BTW the chemicals I used for that little experiment were all procured legitimately. The chem lab was good for a few aromatic items, but the stockroom was somewhat lacking in pyrotechnic materials. And it blew a chunk out of the curtains, not the wall, but I did have a piece of copper lodged in my forehead between my eyes that grew out a few weeks later. It was the world’s first semi-precious zit.” | Yes |
Diverse Gram-negative bacteria use type III secretion systems (T3SS) to translocate effector proteins into the cytoplasm of eukaryotic cells. The type III secretion apparatus (T3SA) consists of a basal body spanning both bacterial membranes and an external needle. A sensor protein lies at the needle tip to detect environmental signals that trigger type III secretion. The Shigella flexneri T3SA needle tip protein, invasion plasmid antigen D (IpaD), possesses two independently folding domains in vitro. In this study, the solution behavior and thermal unfolding properties of IpaD's functional homologs SipD (Salmonella spp.), BipD (Burkholderia pseudomallei), LcrV (Yersinia spp.), and PcrV (Pseudomonas aeruginosa) were examined to identify common features within this protein family. CD and FTIR data indicate that all members within this group are α-helical with properties consistent with an intramolecular coiled-coil. SipD showed the most complex unfolding profile consisting of two thermal transitions, suggesting the presence of two independently folding domains. No evidence of multiple folding domains was seen, however, for BipD, LcrV, or PcrV. Thermal studies, including DSC, revealed significant destabilization of LcrV, PcrV, and BipD after N-terminal deletions. This contrasted with SipD and IpaD, which behaved like two-domain proteins. The results suggest that needle tip proteins share significant core structural similarity and thermal stability that may be the basis for their common function. Moreover, IpaD and SipD possess properties that distinguish them from the other tip proteins.
Gram-negative bacteria possess numerous complex mechanisms for transporting proteins into the extracellular milieu and into the cytoplasm of eukaryotic host cells to initiate bacterial infection (He et al. 2004; Yip and Strynadka 2006). Six major bacterial secretion pathways have been defined with the type III secretion system (T3SS) being a major contributor to mediating host–pathogen communication (Buttner and Bonas 2006). The T3SS is a common theme among diverse Gram-negative bacterial pathogens including the animal pathogens Shigella flexneri, Salmonella typhimurium, Yersinia enterocolitica, Pseudomonas aeruginosa, and Burkholderia pseudomallei, and plant pathogens such as Erwinia amylovora and Pseudomonas syringae (Cossart and Sansonetti 2004; He et al. 2004; Buttner and Bonas 2006). Although these bacteria cause a wide spectrum of disease, each infection is established by the delivery of bacterial proteins through the type III secretion apparatus (T3SA) to the target eukaryotic cell membrane and cytoplasm to subvert normal cell mechanisms.
Sometimes described as a “molecular syringe and needle,” the T3SA is composed of 20–30 proteins that form a basal body spanning the inner and outer bacterial membranes and an external needle (He et al. 2004; Yip and Strynadka 2006). The external needle is a hollow tube ∼50 nm long and 7 nm in diameter with an inner channel that is typically ∼2.5 nm in diameter (Cordes et al. 2003). It is composed of >100 copies of a needle protein with 5.6 molecules per turn of the helix (Cordes et al. 2003). How proteins are prevented from free passage through the needle and how signals are sent from the needle tip to the base to trigger secretion are still unanswered questions.
Recently, a significant step toward answering these questions was made with the identification of a protein that resides at the T3SA needle tip (Mueller et al. 2005; Espina et al. 2006b). For S. flexneri, invasion plasmid antigen D (IpaD) was shown to stably reside at the tip of the TTSA needle, with this localization being required for T3SS secretion control and virulence-related functions (Espina et al. 2006b). Similarly, in Y. enterocolitica, LcrV localizes to the tip to form a distinct complex (Mueller et al. 2005). In addition to functioning as the needle tip proteins for their cognate T3SAs, IpaD and LcrV are required for translocator protein insertion into host cell membranes (Fields et al. 1999; Marenne et al. 2003; Picking et al. 2005).
Despite their functional homology as needle tip proteins, IpaD and LcrV share very little primary sequence similarity. There is significant sequence conservation, however, among members within the IpaD or LcrV needle tip protein subfamilies, respectively, especially at the C termini (see Fig. 1). The closest relatives of IpaD are the invasion proteins SipD and BipD of S. typhimurium and B. pseudomallei, respectively. Like ipaD-null mutants, sipD- and bipD-null mutants are noninvasive, with the sipD strain secreting massive amounts of T3SS effectors (Kaniga et al. 1995; Stevens et al. 2004). These three proteins share >25% sequence similarity, with >90% sequence similarity at their C termini (Kaniga et al. 1995). Similarly, lcrV and the P. aeruginosa pcrV-null mutants are defective for proper type III secretion and show 42% sequence identity, with most of this being within their C termini (Nanao et al. 2003). The crystal structures of LcrV (Derewenda et al. 2004) and, more recently, IpaD and BipD (Erskine et al. 2006; Johnson et al. 2007) have been solved and exhibit a dumbbell-like shape with two globular domains separated by a long coiled-coil. Previously, biophysical measurements have demonstrated that IpaD has two independently folding units with a thermally labile N-terminal and a more thermally stable C-terminal domain containing a coiled-coil (Espina et al. 2006a). Based on the structural and functional conservation between IpaD and LcrV and the high degree of sequence homology within the subfamilies, structural similarities may exist among all of the needle tip proteins that are required for their ability to localize to the needle tip.
In this study, the structure and conformational stability of recombinant SipD, BipD, LcrV, and PcrV are compared to provide insight into the structural basis for their mechanistic similarities. Because IpaD was found to possess an independently folding N-terminal domain, N-terminal deletions were also introduced into these proteins so that the presence of a related domain could be assessed and compared to IpaD. All of the proteins were found to be α-helical with an intramolecular coiled-coil. Only SipD, however, appeared to possess an independently folding N-terminal domain that is analogous to that of IpaD. Based on these results, we propose that, although having divergent primary sequences, all T3SA tip proteins possess similar structural features that are required for their needle tip localization as well as distinct features necessary for their pathogen-specific activities.
Generation of recombinant proteins
An earlier structural analysis of IpaD demonstrated that IpaD is a highly α-helical protein that contains two independently folding domains. The N-terminal domain (residues 1–120) is thermally labile, while the C-terminal domain (residues 121–332) is more stable and contains an intramolecular coiled-coil. Based on the functional similarities between IpaD and the putative T3SA tip proteins, a series of biophysical studies was initiated to compare the structures and conformational stabilities of SipD, BipD, LcrV, and PcrV. Shared structure–function relationships among these proteins might then be extrapolated to all T3SA tip proteins. To assess the impact of the N-terminal region on the four proteins, deletions were made to mimic the IpaD N-terminal deletion. Based on its crystal structure (Derewenda et al. 2004), an LcrV N-terminal deletion mutant was made by deleting the N-terminal domain prior to the intramolecular coiled-coil, giving rise to LcrVΔ1–146. Although the crystal structure of PcrV has not been solved, pcrV can complement an lcrV-null mutant (Mueller et al. 2005), indicating that the core structure of the two proteins should be similar. Thus, the PcrV N-terminal deletion PcrVΔ1–127 was based on an estimate of the location of the boundary between the putative N-terminal domain and coiled-coil region. In contrast, when this study was initiated, none of the crystal structures for the IpaD subfamily had been solved. Therefore, SipDΔ1–121 and BipDΔ1–123 were produced based on the previous IpaDΔ1–120 results. Like the full-length proteins, the deletion mutants were highly soluble when made recombinantly in Escherichia coli.
Secondary structure analysis of SipD, BipD, LcrV, and PcrV
Far-UV CD was initially used to analyze the secondary structure and thermostability of SipD, BipD, LcrV, and PcrV as well as the N-terminal deletion mutants. The CD spectrum for each protein displays double minima at 208 nm and 222 nm, suggesting a significant amount of helical structure (Fig. 1). Their secondary structure contents were estimated from the far-UV CD spectra using the Dichroweb suite of algorithms (Lobley et al. 2002; Whitmore and Wallace 2004) with the program CDSSTR (Manavalan and Johnson Jr. 1987). As previously observed for IpaD (Espina et al. 2006a), these proteins appear to possess a high percentage of α-helical structure with some β-sheet and disordered structure being present (Table 1). Previous studies of PcrV estimated a lower percentage of helical structure (18%) compared to that obtained in the present work (58%) (Nanao et al. 2003). This may be at least partially due to the different experimental temperatures and methods used to estimate the secondary structure content. The N-terminal deletion mutations of these proteins showed CD spectra similar to those of full-length proteins (Fig. 2), indicating fully folded proteins with no major changes in the global folding of the proteins as a result of the truncations. Like IpaDΔ1–120, SipDΔ1–121 and PcrVΔ1–127 displayed a greater relative amount of helical structure than their full- length counterparts (Table 1), which may indicate that the N-terminal regions of these proteins possess less helical character (Espina et al. 2006a). In contrast, BipDΔ1–123 and LcrVΔ1–146 displayed a lower relative amount of α-helix with an increasing percentage of β-sheet and random structures.
Table Table 1.. Secondary structure estimates for SipD, BipD, LcrV, and PcrV and their N-terminal mutants
The thermal stabilities of SipD, BipD, LcrV, and PcrV and the N-terminal deletion mutants were studied by monitoring the changes in the ellipticity at 222 nm as a function of temperature (Fig. 2). SipD displayed two distinct thermal transitions, one minor and one major, at ∼57°C and 75°C, respectively, suggesting the presence of two independently folded domains (Fig. 2; Table 2). The SipDΔ1–121 mutant only displayed the major transition, suggesting that the structural domain responsible for the low-temperature minor transition resides near the N terminus of SipD, which is similar to the transition pattern observed for IpaD (Espina et al. 2006a). In contrast, BipD, LcrV, and PcrV display a single transition, with BipD and LcrV being the most stable with transition midpoints around 80°C. In good agreement with previous results (Nanao et al. 2003), PcrV displayed a transition midpoint around 65°C. In general, N-terminal deletions introduced into BipD, LcrV, and PcrV resulted in a decrease in thermal stability (Fig. 2; Table 2).
Table Table 2.. Thermally induced unfolding of Sip, BipD, LcrV, PcrV, and their N-terminal mutants evaluated by spectroscopic techniques
Like IpaD, the deletion mutations all give rise to folded proteins possessing extensive secondary structure that could be attributed to a stable intramolecular coiled-coil (Fig. 1). Thus, the secondary structure of SipD, BipD, LcrV, and PcrV was analyzed by FTIR spectroscopy. The amide I′ region of the full-length proteins at 25°C dissolved in D2O was decomposed into its component peaks based on Fourier self-deconvolution and second derivative analysis (Fig. 3). The peak deconvolution for the four proteins showed three predominant bands around 1633, 1644, and 1653 cm−1, with small variations depending on the protein under analysis (Table 3). This triplet of equally intense bands observed in the FTIR spectrum of the proteins has been taken as a unique spectral fingerprint of intramolecular coiled-coil proteins (Heimburg et al. 1996, 1999). The spectrum of BipD is slightly different from that of the other proteins since the high-frequency peak of the triplet possesses a higher intensity, a feature often seen with trimeric coiled-coils (Heimburg et al. 1996, 1999), while exhibiting a single thermal transition. In contrast, as was seen in the CD spectrum, SipD possesses two thermal transitions. LcrV and PcrV exhibit only one major transition (Fig. 3B,C). A progressive increase in breadth of the amide I′ region along with the appearance of a sharp band at ∼1616 cm−1 and a weak signal at ∼1680 cm−1 were common features for all proteins upon heating (Fig. 3B). These particular bands are characteristic of protein aggregation due to the formation of intermolecular β-sheets (Arrondo et al. 1994; Murayama and Tomida 2004). For BipD and SipD, the observed aggregation seems to be influenced by protein concentration, since it was not detected in more dilute solutions of the proteins during turbidity experiments (see below). Although FTIR experiments require samples with a much higher protein concentration than CD, an analysis of the thermal stability of the proteins based on the intensity of the 1616 cm−1 band showed transition temperatures similar to those detected by CD spectroscopy (Fig. 3C).
Table Table 3.. Peak position and percentage of area corresponding to the curve fitting Gaussian components of the amide I′ band of BipD, SipD, LcrV, and PcrV at pH 7.4 and 25°C
Analysis of tertiary structure by fluorescence and second derivative UV absorption spectroscopies
Because SipD, BipD, LcrV, and PcrV possess four, four, one, and three tryptophan residues, respectively, intrinsic fluorescence spectroscopy was used to monitor changes in their tertiary structure. The four Trp residues of SipD and BipD are also present in the truncated forms of the proteins while LcrVΔ1–146 does not contain a Trp residue and was therefore not further analyzed by this technique. Intrinsic Trp fluorescence is highly environmentally sensitive and is widely used to monitor changes in Trp microenvironments resulting from alterations in protein tertiary structure. Exposure to more polar environments generally results in Trp emission being shifted to a longer wavelength (red shift), while movement into more apolar regions produces a blue shift (Lakowicz 1983). The Trp emission spectra of the full-length proteins and three of the N-terminal deletion mutants manifest a maximum between 328 and 336 nm, indicating that the tryptophans are on average buried within the apolar core of the needle tip proteins. In contrast, the emission maximum for SipDΔ1–121 was red shifted ∼5 nm with respect to the spectrum of the full-length protein (Fig. 4A), suggesting at least partial exposure of the Trp in this mutant. In response to increasing temperature, the Trp emission wavelength maximum for SipD (Fig. 4A) red-shifted significantly and displayed two thermal transitions centered at ∼57°C and 74°C. These values agree well with those detected by CD analysis (Table 2). In contrast, SipDΔ1–121 only exhibited a single broad transition between 65°C and 82°C, which is again consistent with the CD thermal unfolding data (Fig. 4A; Table 2). The overall observed red shift is consistent with increased solvent exposure of the Trp residues resulting from temperature-induced unfolding (Fig. 4A). BipDΔ1–123 and PcrVΔ1–127 showed overall destabilization of the molecule with lower Tm values than the corresponding full-length proteins (Fig. 4A). The blue shift in the Trp emission maximum observed for LcrV and PcrV (Fig. 4A) at high temperatures is probably due to extensive aggregation of the proteins resulting from temperature-induced unfolding.
To further characterize changes in the tertiary structure of SipD, BipD, LcrV, and PcrV, the thermal unfolding of the proteins was evaluated in the presence of 1-amino-8-napthalenesulfonate (ANS), an extrinsic probe that often binds to apolar regions of proteins. The fluorescence of ANS is highly quenched in aqueous solution but can increase dramatically upon binding to protein apolar regions (Rosen and Weber 1969). SipD showed two well-defined transitions at ∼49°C and 68°C which were attributable to exposure of apolar regions caused by the conformational alterations within the two individual domains (Fig. 4B; Table 2). SipDΔ1–121 showed a single transition near 70°C (Fig. 4B; Table 2), confirming the CD and intrinsic fluorescence observations (Fig. 4A). When the unfolding of full-length and N-terminal mutants of BipD, PcrV, and LcrV were evaluated by ANS fluorescence, the truncated proteins showed lower thermostability as evaluated by their Tm values (Fig. 4B; Table 2), which again indicates a destabilizing effect on the proteins after truncation.
SipD, BipD, LcrV, and PcrV also possess substantial numbers of the aromatic amino acids tyrosine and phenylalanine. Changes in the microenvironments of these residues also induce changes in their spectral characteristics, thus providing a means for monitoring tertiary structure stability that is not completely dependent on the presence of scarce Trp residues. The second derivative spectra of the proteins showed five to six negative peaks with the following general assignments: Phe (∼253 nm and 259 nm), Tyr (at 274 nm and 279 nm), an overlapping Tyr/Trp signal (at 282 nm), and Trp (at 291 nm) (spectra not illustrated). In general, exposure of aromatic amino acid side chains to a more polar environment causes a blue shift in the absorbance minimum, whereas shifts to longer wavelengths suggest that the residues are present in a more buried, less polar environment (Mach and Middaugh 1994). The Tyr/Trp signal was found to be the most well-behaved and superior in signal-to-noise ratio to the other peaks in the analysis of the protein's stability (Fig. 5). The Tyr/Trp peak positions of SipD and SipDΔ1–121 show a quasilinear temperature-dependent decrease in wavelength before the thermal transition. Broad transitions around 71°C and 74°C were observed for SipD and SipDΔ1–121, respectively, with an overall blue shift (Fig. 5A; Table 2). Surprisingly, this is the only technique of those used that does not clearly demonstrate a double transition for full-length SipD, suggesting that the N-terminal portion does not strongly impact the thermal response of this particular second derivative minimum. The Tyr/Trp peak positions of BipD and BipDΔ1–123 remain relatively constant until 65°–75°C, respectively, suggesting that the tertiary structure of the protein undergoes negligible changes up to this temperature (Fig. 5A). Above these temperatures, the Tyr/Trp peak positions shift to lower wavelengths, suggesting that the aromatic residues are becoming more exposed to the solvent, in good agreement with the intrinsic fluorescence observations (Fig. 4A). The noise in the signals observed in LcrVΔ1–146 and PcrVΔ1–127 at temperatures above the transition is almost certainly a consequence of the extensive aggregation detected for these proteins (Fig. 5B). In general, the transition temperatures agreed well with those seen for the transitions detected by CD spectroscopy (Table 2).
SipD, BipD, LcrV, PcrV, and their N-terminal mutants' associative behavior was evaluated by monitoring the turbidity (OD) at 360 nm as the temperature was increased (Fig. 5B). In general, all of the proteins showed an increase in turbidity starting at ∼50°–65°C depending on the protein, with well-defined transitions (Fig. 5B; Table 2). The drop in turbidity after the transition is due to settling of the precipitated aggregates within the cuvette. It is noteworthy that no aggregation was detected for SipD, BipD, and BipDΔ1–123, which is similar to previous findings for IpaD and IpaDΔ1–120 (Espina et al. 2006a).
Analysis of thermal unfolding by differential scanning calorimetry
Differential scanning calorimetry (DSC) is another useful method for analyzing the thermal unfolding of proteins with the potential to provide a direct energetic description of distinct protein unfolding events. The SipD thermogram was quite complex showing high-temperature (∼85°–90°C) transitions not detected by most spectroscopic techniques (Fig. 6). Although the protein displayed five distinct transitions, the Tm for the first and third transitions agreed well with those values for the double transition detected by CD and fluorescence experiments (Table 2; Fig. 5). SipDΔ1–121 displayed only the major and high-temperature transitions (Fig. 6). The rest of the proteins under study showed one endothermic transition (Fig. 6). Except for the BipD thermogram, the best fit using a non-two-state model was composed of two peaks for each protein (Table 4). N-terminal truncation of BipD, LcrV, and PcrV caused destabilization of the proteins with a 10°–20°C drop in the Tm values compared to those found for the respective full-length protein thermograms (Fig. 6; Table 4). Thus, DSC confirms the high thermal stability of these proteins, which is probably at least partially a result of the intramolecular coiled-coil. It also illustrates the presence of two independently folding domains that appears to be unique to IpaD and SipD. Lack of complete reversibility prevented calculation of the enthalpies of unfolding. Hints of a second transition are for the first time present using this technique for the other proteins.
Table Table 4.. Thermal unfolding of SipD, BipD, LcrV, PcrV, and Δ1–120 N-terminal mutants by DSC
In this study, we have extensively characterized the conformational stability of SipD, BipD, LcrV, and PcrV, all of which have either been found or are proposed to be located at the tip of the T3SA needles of S. typhimurium, B. pseudomallei, Y. enterocolitica, and P. aeruginosa, respectively. Their structural properties were then compared to the recently well-characterized properties of IpaD from S. flexneri. These needle tip proteins appear to fall into two main subfamilies: the IpaD subfamily consists of IpaD, SipD, BipD, and possibly other proteins that belong to related T3SSs that are largely involved in cellular invasion; and the LcrV subfamily, which consists of LcrV, PcrV, and other proteins, many of which are involved with modifying eukaryotic cell behavior for other purposes (e.g., prevention of phagocytosis and cell death).
Based on the initial biophysical characterization of IpaD, it was anticipated that this subfamily of needle tip proteins would be highly α-helical and possess two independently folding domains, with the N-terminal third of the protein forming a thermally labile domain and the C-terminal two-thirds being more heat stable and containing a large intramolecular coiled-coil. SipD followed this pattern, but surprisingly BipD did not. BipD shares significant sequence identity with IpaD and SipD, especially within the C-terminal half of the protein, but it exhibits only one thermal unfolding transition that is even more stable than the higher of the two transitions seen for IpaD and SipD. FTIR analysis suggests that BipD possesses an intramolecular coiled-coil, but it may be somewhat different from that of IpaD and SipD because it exhibits spectral characteristics between that of a double- and triple-stranded coiled-coil (Heimburg et al. 1996, 1999). It is possible that the N-terminal region of BipD interacts more extensively with the intramolecular coiled-coil than do the N-terminal regions of IpaD or SipD. As a result, not only does the FTIR spectrum of BipD resemble a triple coiled-coil, but interaction of the N-terminal region with the coiled-coil may prevent the formation of a fully independently folding domain as seen with IpaD and SipD. This idea is corroborated by an overall thermal destabilization of BipD when the N-terminal region is removed. Indeed, during the preparation of this manuscript, the crystal structures of IpaD and BipD were solved (Erskine et al. 2006; Johnson et al. 2007). Like LcrV, IpaD and BipD have a dumbbell-like shape with globular domains flanking an intramolecular coiled-coil, which forms the handle. The N-terminal domain of IpaD forms a helix–turn–helix that is almost identical in structure to MxiH, its cognate T3SA needle protein, followed by a short α-helix that attaches the domain to the coiled-coil. Based on the biophysical characterization, it appears that this domain is able to unfold and fold independently of the remainder of the protein. This property may be important for the virulence of Shigella. In contrast, the N-terminal domain of BipD is longer, with more of a loop rather than a turn. This loop appears to form a stronger interaction with the coiled-coil, which accounts for the apparent triple-stranded coiled-coil of BipD. Thus, although BipD does not possess the two independently folding domains structure of IpaD and SipD, it may have an N-terminal domain whose unique structural characteristics point to a unique biological function for this region of the protein.
The LcrV subfamily of needle tip proteins differs significantly from the members of the IpaD subfamily based on sequence, but the members share significant sequence similarity among themselves, especially in their C-terminal halves. In considering the published crystal structure of LcrV (Derewenda et al. 2004) in the context of the biophysical characteristics of the two subfamilies, it appears likely that the N-terminal domain of the LcrV subfamily does not exist as a well-defined, independently folding domain, making the native organization of the proteins of the two subfamilies different from one another. This may directly reflect the divergence in function between the two subfamilies. Furthermore, the lack of independent folding domains would also readily explain why deletion of the LcrV N-terminal domain and the putative PcrV N-terminal domain results in overall protein destabilization. Nevertheless, even these proteins continue to form highly folded, stable structures when the N-terminal deletion is introduced. This is probably because of the stable nature of the intramolecular coiled-coil that all of these tip proteins seem to possess.
It has been previously noted that the tip proteins can exist in various multimerization states. LcrV has been described to be a dimer and multimers thereof (Lawton et al. 2002). Similarly, the N-terminal truncation of IpaD that provided its original crystal was present as a dimer (Johnson et al. 2007). In this study, gel filtration chromatography showed that IpaD, SipD, and BipD elute as monomers, PcrV was primarily monomeric, and LcrV appeared to be present as both a monomer and dimer. In contrast, all of the N-terminal deletion mutants appear to behave as oligomers. Although oligomerization has been reported to occasionally provide increased thermal stability to a protein, this property was not apparent for the tip protein family upon deletion with the N-terminal domain since the second melting transition is lower than that of the full-length protein. Owing to the presence of multiple oligomerization states for LcrV, the impact of this property on the biophysical characterization of this protein cannot be directly assessed. The multimeric state of these proteins and deletion mutants is likely due to interactions involving the coiled-coil (Lawton et al. 2002; Johnson et al. 2007), a property required for proper oligomerization at the tip of the needle (Deane et al. 2006). Once the N-terminal domain has been removed, the coiled-coil is exposed, promoting spontaneous oligomerization.
The presence of coiled-coils and/or helices that fold back upon themselves appears to be a recurring theme for many T3SS secreted proteins. All of the needle monomer structures solved to date have a helix–turn–helix structure that centers around a PXXP turn motif that is shared by almost all known needle protein monomers (Deane et al. 2006; Zhang et al. 2006). At the end of the needle resides a tip protein that possesses a prominent intramolecular coiled-coil that is not only required for the structure of the tip protein but for the interaction of the tip protein with the needle itself (Deane et al. 2006; Espina et al. 2006b). Within the IpaD tip protein subfamily, it appears that the N-terminal domain mimics the needle protein to chaperone the coiled-coil (Johnson et al. 2007). After exit from the needle, the domain is repositioned to allow the coiled-coil to dock onto the needle. In Shigella, the next secreted protein to localize at the needle tip is IpaB (Olive et al., in press), one of the two translocator proteins, which is also predicted to possess a coiled-coil motif (Johnson et al. 2007). Similarly, the other Shigella translocator protein, IpaC, is predicted to contain a coiled-coil that may be involved in protein–protein interactions (Pallen et al. 1997). As a rule, disruption of these helical structures results in a loss of T3SS function (Kueltzo et al. 2003b; Picking et al. 2005; Espina et al. 2006b). Regions outside the helical core of these proteins appear to impart specific pathogen functions (Kueltzo et al. 2003b; Picking et al. 2005; Espina et al. 2006b; Johnson et al. 2007).
This study provides the first detailed biophysical characterization of a family of T3SA needle-associated proteins and builds on the recent crystal structures of three of the tip proteins. It is now clear that there are certain structural features that seem to generally apply to this group of proteins. The secondary structure analyses of these five T3SA needle tip proteins suggest that all of the T3SA needle tip proteins are highly α-helical and contain an intramolecular coiled-coil located within the C-terminal two-thirds of the protein that dictates the nature of the tip protein interaction with the needle tip. The independently folded N-terminal domain of IpaD and SipD is not clearly identifiable within all of tip proteins within the resolution of the approaches used here. The presence or absence of an independently folding N-terminal domain may be associated with biological functions, in addition to needle tip localization, that are unique to the individual proteins. The lack of multiple transitions, however, does not exclude the presence of distinct domains having similar thermal stabilities. Since it appears that IpaD and the other needle tip proteins are a structural component of the T3SA needle, it is noteworthy that a major feature of flagellin is the existence of a coiled-coil structure that contributes to flagellar filament polymerization. This may reflect a similarity in the mechanism by which the helix–turn–helix region of the needle proteins mediates needle filament assembly (Deane et al. 2006). In this respect, the needle tip proteins may represent a short extension of the T3SA needle that is capable of sensing the environment to control the subsequent secretion of T3SS secretion substrates (Olive et al., in press). While speculative, this model for assembly of the external portion of the T3SA provides a basis upon which future investigation can be built.
Materials and Methods
The pET15b plasmid containing pcrV, pET/V, was a gift from I. Attree (CEA-Grenoble, Grenoble, FR) (Nanao et al. 2003). The pET9b plasmid containing lcrV was donated by M. Nilles (University of North Dakota, Grand Forks, ND). Chromosomal DNA from B. pseudomallei (strain K96243) was a gift from D. DeShazer (United States Army Medical Research Institute of Infectious Disease, Fort Detrick, Fredrick, MD). pET15b and competent E. coli were from Novagen. Oligonucleotides were obtained from IDT.
Preparation of affinity-purified recombinant proteins
The sipD gene was subcloned from pwpsf4 (Picking et al. 2005) into pET15b by previously described methods (Harrington et al. 2003). The bipD gene was copied from B. pseudomallei chromosomal DNA by PCR using a 5′-primer containing GAGAGA, an NdeI restriction site, and the first 14 bases of the gene; and a 3′-primer containing GAGAGA, a BamHI site, and the last 14 bases of the gene. The resulting PCR fragment was digested with NdeI/BamHI and ligated into pET15b, and the ligated plasmid was transformed into E. coli NovaBlue. The N-terminal deletion mutants were made by copying the truncated gene from the plasmid containing the full-length gene using a T7 terminator primer as the 3′-primer and the following as the 5′-primers: sipDΔ1–121, GAGAGACATATGGCGCAGCCGAGAAC; bipDΔ1–123, GAGAGACATATGATCCAGCCGGACCCGA; lcrVΔ1–146, GAGAGACATATGCATGGTGATGCCCGTAG; pcrVΔ1–127, GAGAGACATATGAAGCGCAAGGCGCTGC. The resulting PCR products were digested with NdeI and BamHI or XhoI for sipD and ligated into pET15b, and the ligation products were transformed into E. coli NovaBlue.
The expression plasmids were transformed into E. coli Tuner (DE3) with the recombinant proteins purified as previously described using nickel chelation chromatography (Marquart et al. 1995), dialyzed against 10 mM Na2HPO4 (pH 7.0), 150 mM NaCl (PBS), and stored at −70°C. Protein concentrations were determined by measuring the absorbance at 280 nm using extinction coefficients based on the amino acid composition of each protein (Mach et al. 1992).
Far-UV circular dichroism spectroscopy
Far-UV CD spectra were collected in a Jasco J720 spectropolarimeter (Jasco, Inc.) as previously described (Ausar et al. 2005; Espina et al. 2006a) using a protein concentration of 0.1 mg/mL. Spectra were collected at 10°C in 0.1-cm path-length cuvettes using a resolution of 0.5 nm, 2-sec response time, and a scanning speed of 20 nm/min. Thermal unfolding was followed by monitoring the ellipticity at 222 nm from 10°C to 90°C. Data analysis was performed as previously described (Espina et al. 2006a).
The secondary structure of the full-length proteins in solution was also assessed using Fourier transform infrared (FTIR) spectroscopy with an ABB Bomen FTIR MB series spectrometer (ABB Bomen). Samples of 1 mL of protein in D2O (15–18 mg/mL) were placed onto an attenuated total reflectance (ATR) crystal equipped with an A.R.K. temperature controller (Spectra-Tech). Spectra were collected under dry air purge using a resolution of 4 cm−1 and the co-addition of 256 interferograms. Data analysis was performed as described previously (Espina et al. 2006a).
UV absorbance spectroscopy
High-resolution absorbance spectra were collected as described (Kueltzo et al. 2003b; Ausar et al. 2005; Espina et al. 2006a) using a protein concentration of 0.1 mg/mL in a Hewlett-Packard 8453 UV-Visible spectrophotometer (Agilent). Spectra were analyzed between 200 nm and 400 nm with an experimental resolution of 1 nm over a temperature of 10°–90°C at 2.5°C intervals. A 3-min equilibration time was used before collection of each spectrum. The optical density at 360 nm was simultaneously recorded as the measure of protein association/aggregation.
Intrinsic and extrinsic fluorescence spectroscopy
Tryptophan fluorescence and externally bound 8-anilino-1-naphthalene sulfonate (ANS) were monitored as previously described (Kueltzo et al. 2003a; Ausar et al. 2005; Espina et al. 2006a) using a PTI QuantaMaster spectrophotometer (Photon Technology International) equipped with a Peltier controlled cuvette holder. The protein concentration used was 0.1 mg/mL. A 1-cm path-length cuvette with Teflon cap was used in all experiments. Spectra were collected from 10°C to 90°C at 2.5°C intervals with a 3-min equilibration time at each temperature. The excitation wavelengths for Trp and ANS were set at 280 and 385 nm, respectively.
Differential scanning calorimetry (DSC)
Calorimetric experiments were performed as previously described (Espina et al. 2006a) using a protein concentration of 2 mg/mL with a MicroCal VP-DSC high-throughput capillary differential scanning calorimeter (Northampton). DSC thermograms were obtained from 10°C to 115°C at a scan rate of 1°C/min with a protein concentration of 2 mg/mL in PBS. Baseline correction was performed by subtracting a buffer thermogram obtained under identical conditions. The data were analyzed using MicroCal Origin 7.0 (Origin-Lab Corporation) assuming a non-two-state unfolding model (Sanchez-Ruiz 1992).
This work was supported by PHS grants AI034428 and AI057927. Technical assistance from Roma Kenjale and members of the Middaugh Lab is gratefully acknowledged. Critical reading of the manuscript by members of the Picking Lab is also acknowledged. | Yes |
“Epilepsy is the most common chronic neurological disease, affecting about 1% of the world’s population during their lifetime. Most people with epilepsy can attain a seizure-free life upon treatment with antiepileptic drugs (AEDs).
Unfortunately, seizures in up to 30% do not respond to treatment. It is estimated that 90% of people with epilepsy live in developing countries, and most of them receive no drug treatment for the disease. This treatment gap has motivated investigations into the effects of plants that have been used by traditional healers all over the world to treat seizures.
Extracts of hundreds of plants have been shown to exhibit anticonvulsant activity in phenotypic screens performed in experimental animals.
Some of those extracts appear to exhibit anticonvulsant efficacy similar to that of synthetic AEDs.
Dozens of plant-derived chemical compounds have similarly been shown to act as anticonvulsants in various in vivo and in vitro assays.
To a significant degree, anticonvulsant effects of plant extracts can be attributed to widely distributed flavonoids, (furano)coumarins, phenylpropanoids, and terpenoids.
Flavonoids and coumarins have been shown to interact with the benzodiazepine site of the GABAA receptor and various voltage-gated ion channels, which are targets of synthetic AEDs.
Modulation of the activity of ligand-gated and voltage-gated ion channels provides an explanatory basis of the anticonvulsant effects of plant secondary metabolites.
Many complex extracts and single plant-derived compounds exhibit antiinflammatory, neuroprotective, and cognition-enhancing activities that may be beneficial in the treatment of epilepsy.
Thus, botanicals provide a base for target-oriented antiepileptic drug discovery and development.
In the future, preclinical work should focus on the characterization of the effects of plant extracts and plant-derived compounds on well-defined targets rather than on phenotypic screening using in vivo animal models of acute seizures. At the same time, available data provide ample justification for clinical studies with selected standardized botanical extracts and plant-derived compounds.” | Yes |
In the summer of 2017 an undergraduate student from Dr Nick Chilton’s group, Jon Kragskow, gave a talk in our group meeting in Manchester about why linear iron(I) compounds had provided some of the most spectacular d-block single-molecule magnets (SMMs) to date. Our group had been working on making axial lanthanide SMMs, which can hold magnetic memory at relatively high temperatures1. As Dr Conrad Goodwin, a postdoc in my group at the time, had been using substituted cyclopentadienyl ligands to make such compounds, we wondered aloud if an anion of ferrocene would be a good SMM.
Ferrocene is a landmark compound with an iron atom “sandwiched” between two cyclopentadienyl ligands, and was first reported in the 1950s; the facile oxidation of ferrocene to its cation, ferrocenium, has been known almost as long as ferrocene itself2. In 2016 a synthetic tour-de-force from chemists based in Germany furnished an isolated decamethylferrocenium dication, a new member of this family3. I read the paper with great interest at the time, then the next day turned back to thinking about the f-block, where our group spends most of its time.
We were surprised to find that a ferrocene anion had never been isolated, and the deeper we delved the more excited we got - we no longer wanted to target such a compound for its SMM properties, we just wanted to make it because we found it fascinating. Seminal work pioneered in the 1970s identified d-block metallocene anion formation in low temperature electrochemistry experiments, but they proved too unstable to isolate4. As f-block chemists we were familiar with recent literature that showed substituted cyclopentadienyls are privileged ligands for stabilising low oxidation state f-block compounds5.
With this in mind, Conrad went to the lab and applied these f-block methods to the d-block to isolate a derivatised ferrocene anion, together with manganese and cobalt analogues, to give a family of compounds. Conrad and I asked our friend and collaborator Dr Nick Chilton if he and his group would be interested in performing measurements and calculations on these compounds, and they happily agreed. In early 2018 Conrad moved to Los Alamos National Laboratory, and we hoped for a straightforward wrapping up of this work.
Conrad’s reaction flasks charged with metallocenes and reducing agents (left-right: potassium graphite (KC8); manganese(II) precursor; KC8; iron(II) precursor; KC8; cobalt(II) precursor.
Two years of challenging measurements were to follow – the thermal sensitivity of these compounds made magnetic data difficult to interpret, and a number of people from both research groups helped finish off this work. Electron paramagnetic resonance spectroscopy performed by Drs Marcus Giansiracusa and Michele Vonci provided crucial experimental evidence of the unusual spin state in the ferrocene anion, and Nick and Michele performed high-level calculations to underpin the experimental data. A chance encounter with Dr Sam Greer and Prof. Steve Hill at a conference in Japan in mid-2018 led to a Mössbauer spectroscopy study as the cherry on the cake.
I hope others also find ferrocene anions fascinating, and to see metallocene anion chemistry flourish in the years to come.
My thanks go to Conrad and Nick for providing comments on this blog, and to Conrad for providing the photos.
- Goodwin, C. A. P., Ortu, F., Reta, D., Chilton, N. F. & Mills, D. P. Molecular magnetic hysteresis at 60 K in dysprosocenium. Nature 548, 439–442 (2017).
- Astruc, D. Why is Ferrocene so Exceptional?. Eur. J. Inorg. Chem. 6–29 (2017).
- Malischewski, M., Adelhardt, M., Sutter, J., Meyer, K. & Seppelt, K. Isolation and structural and electronic characterization of salts of the decamethylferrocene dication. Science 353, 678–682 (2016).
- Geiger Jr, W. E. Electroreduction of cobaltocene. Evidence for a metallocene anion. J. Am. Chem. Soc. 96, 2632–2634 (1974).
- Evans, W. J. Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States. Organometallics 35, 3088–3100 (2016). | Yes |
ERIC Number: EJ241241
Record Type: CIJE
Publication Date: 1981-Jan
The Gibbs Function versus Degree of Advancement.
Cohen, Richard W.; Whitmer, John C.
Journal of Chemical Education, v58 n1 p21-24 Jan 1981
Describes how Gibbs valley graphs can clarify the relation between the Gibbs function and chemical equilibrium. Gives examples from gas phase equilibria. (CS)
Publication Type: Journal Articles; Reference Materials - General; Guides - Non-Classroom
Education Level: N/A
Authoring Institution: N/A | Yes |
Scientists from Germany have developed a unique robotic nnoruka, the components of which are DNA molecules.
It is controlled by the electric field of the outer type. Such a system can independently move different molecules and nanoparticles several tens of nanometers, that it will take no more than 5 milliseconds.
These features several times faster than when using molecular robots made of DNA that are under the control of chemical reactions.
Thanks to the available opportunities for the formation of complementary relations that exist between the nitrogenous bases, DNA molecules can be used to recreate complex polymer systems in which will be spelled out in advance the structure and the desired arrangement of functional groups.
A similar mechanism can be used in the so-called technique of “origami” from DNA, which can be used to assemble molecular structures of medicines and luminescent systems.
Scientists propose to use the approach to create molecular robots that can perform simple work with nano-objects. | Yes |
|File:Clomethiazole Structural Formulae.png|
|Systematic (IUPAC) name|
|ATC code||N05CM02 (WHO)|
|Molar mass||161.653 g/mol[[Script error: No such module "String".]]|
Clomethiazole (also called Chlormethiazole) is a sedative and hypnotic that is widely used in treating and preventing symptoms of acute alcohol withdrawal. It is a drug which is structurally related to thiamine (vitamin B1) but acts like a sedative, hypnotic, muscle relaxant and anticonvulsant. It is also used for the management of agitation, restlessness, short-term insomnia and Parkinson's disease in the elderly. In the U.K, it is sold under the brand Heminevrin (AstraZeneca Pharmaceuticals). Another brand name includes Nevrin (in Romania). The drug is marketed either as a freebase in an oily suspension containing 192mg (about 3 grains) in capsule form, or as clomethiasole edisylate (ethane disulfonate) syrup.
Chlomethiazole acts as a positive allosteric modulator at the barbiturate/picrotoxin site of the GABA-A receptor. It works to enhance the action of the neurotransmitter GABA at this receptor. GABA is the major inhibitory neurotransmitter in the brain and produces anxiolytic, anticonvulsant, sedative, and hypnotic effects. Chlomethiazole also inhibits the enzyme alcohol dehydrogenase, which is responsible for breaking down alcohol in the body. This slows the rate of elimination of alcohol from the body, which helps to relieve the sudden effects of alcohol withdrawal in alcoholics. Chlomethiazole appears to also have another mechanism of action mediating some of its hypothermic and neuroprotective effects.
Long term and frequent use of chlormethiazole can cause tolerance and physical dependence. Abrupt withdrawal may result in symptoms similar to those of sudden withdrawal of alcohol or benzodiazepines, including apnoeic-tonic seizures.
The Who drummer, Keith Moon, died from a massive overdose of chlormethiazole. The coroner determined he had consumed 32 tablets in total, the digestion of only 6 of which had been necessary to cause his death.
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- Reith DM, Fountain J, McDowell R, Tilyard M (2003). "Comparison of the fatal toxicity index of zopiclone with benzodiazepines". J. Toxicol. Clin. Toxicol. 41 (7): 975–80. doi:10.1081/CLT-120026520. PMID 14705844.
- Fletcher, Tony: "Moon: The Life and Death of a Rock Legend". | Yes |
|Grades||Nickel 200, Nickel 201, Nickel 205|
|Standard||ASTM B164, ASTM B160, etc.|
|Straight||Dia.: 1.0mm-5.0mm ( tolerance: +/-0.05mm )|
|Coiled||Dia.: 0.03mm-3.0mm ( tolerance: +/-0.05mm )|
|Length||Coils or Customers’ Requests|
|Surface||Black, Pickled, Polished ( For Dia. >1mm )|
|Packing||Standard seaworthy packages or as your requests|
Nickel wire is made by advanced vacuum melting process and by forging, rolling, annealing and drawing, it has good mechanical strength, corrosion-resistant and heat-resistance strength. Nickel wire is used to make electrical vacuum device, electronic instrument components and anti-corrosion materials for chemical industry.
The state hard state/half hard/soft state
Properties of Nickel Wire
Resistant to all dry gases at room temperature
Excellent resistance to acid, alkaline and neutral salt solutions.
Relatively nominal electrical resistivity
Superior resistance to corrosion in acid or alkaline conditions and de-aerated acid
Resistance to inter granular attack above 315oC
Electric apparatus and chemical machinery
Making valves grid, inner components of vacuum valves
Components insides the electron tubes
Strong base of the filter
Room Temperature Tensile
Near Surface Examinations
Package Wooden case or according to your requirements.
Special specifications can be produced in accordance with the customer’s requirements. | Yes |
CCOVI Analytical Services lab is a full-service facility that offers competitive pricing packages for a wide range of standard analytical services to the grape and wine, cider, beer, and distillery industries, including but not limited to:
- Juice, wine, and alcoholic beverage analysis for Brix, pH, TA, VA, residual sugar, alcohol, free and total SO2, malic acid, yeast assimilable nitrogen (YAN), protein stability, cold stability, ethyl acetate, methanol, methoxypyrazines, Brettanomyces markers, potassium, copper, and sodium, as well as microbial examination.
We now offer these services:
- Cork moisture content measurement – $10 per sample
- Yeast identification in wine – $200 per sample (3 species)
Every sample is tested in duplicate using validated methods. We provide swift turnaround service on all analyses, which is determined on a case-by-case basis.
Please see our full services list below, as well as instructions for submitting samples.
Please contact us to discuss any requests for contract projects or special analyses.
The Analytical Services lab is located in Inniskillin Hall, room 215, at Brock University (1812 Sir Isaac Brock Way).
Navigate to Brock University’s northeast entrance, off Glenridge Avenue across from John Macdonell Street. Turn west into campus. There will be a small traffic circle. Take the second exit from the traffic circle, which is marked with a short blue sign indicating “Shipping/Receiving”. Drive forward toward the buildings. Inniskillin Hall is to the right, with purple-red accents on the windows.
There are two “Reserved CCOVI” parking spots in front of the building available for quick parking. Put on your four-way flashing lights and follow the sidewalk to the entrance at the right. Once in the lobby, turn left and follow the hallway to a set of purple double doors. Turn right and IH215 Analytical Services is the first door on the right.
*There are extra forms and further instructions outside of the lab if the door is closed. | Yes |
FolaPro features Metafolin‚, the active, preferred form of folate called calcium L-5-methyltetrahydrofolate.*
- Features calcium L-5-methyltetrahydrofolate —a body-ready form of folate, helping to ensure all of the critical benefits of folate nutrition are realized*
- Requires no additional metabolic steps to be utilized by the body, making it a preferred choice for many individuals*
- Nutritionally supports many metabolic processes*
- Folate is an essential nutrient for many body processes including DNA synthesis. | Yes |
The magnetic properties of the compound-type cobaltites (Ln = Lanthanide and A = alkaline-earth) are extremely dependent on the structural deformation, which can be induced by either chemical substitution or applying pressure. These two approaches are not equivalent because the atomic substitution changes the ratio of and . It is well known that the additional electron of plays a fundamental role in the magnetic and electric properties of these materials. Thus, the pressure is a way to influence the magnetic and electric properties considering only the structural deformation. In this work, pressure was applied to deform the structure of and, thus, to elucidate its effect on the structural and magnetic properties. The findings show that even under pressure of 50 kbar, no structural phase transition was detected, but the unit cell volume significantly decreases by 2.8% and the Co--Co bond angle increases by 2.6%. However, the elasticity parameter (defined as the Co-O apical distance divided by the square root of the octahedral basal area) remained constant over the pressure range. The magnetic properties were evaluated up to 10.9 kbar, and the findings show that varies with a rate of 0.5 K/kbar, and that the magnetic entropy change of the compound remains almost constant at a value of −2 J/kg K for 5 T of magnetic field variation. The and ions were found to be in an intermediate spin state and remain the same over all studied pressure interval. To conclude, the structural deformation induced by the high pressure seem to not affect the magnetic properties, and the elasticity parameter is a useful tool sensitive to this change. These results indicate that, for strongly correlated electron system, the ratio of and is much more critical for changing the magnetic properties than the structural deformation. | Yes |
HETEROGENEOUS PHOTOCATALYSIS FIELD BELONGS TO THE GENERAL AREA OF CATALYSIS
Heterogeneous photocatalytic reactions should be studied by following the same methodology used for heterogeneous catalytic reactions and similar problems must be faced.
Thermodynamic and kinetic constraints must be fulfilled.
Intrinsic Electronic Characteristics
vb and cb Energies Band Gap Value
Lifetime of the Photogenerated Electron-Hole Pairs
Allotropic Phase Defects etc.
Specific Surface Area Porosity Point of Zero Charge Surface Hydroxylation
Surf. Basicity and Acidity
Presence of Dopants | Yes |
If we’re going to colonize Mars, we’ll need buildings to live and work in. So researchers have made cheap, strong concrete out of “Martian” soil.
There is growing interest in the goal of sending humans to Mars. Various space agencies have begun to study the numerous problems such a mission would present, not least of which is protecting humans during the journey.
But once humans arrive on the red planet, they will require high quality buildings in which to live and work. They can take certain structures with them but this can only be a temporary solution. The first colonizers will quickly have to find a way to build structures using the planet’s own resources. But how?
Today we get an answer thanks to the work of Lin Wan and pals at Northwestern University. These guys have worked out how to make Martian concrete using materials that are widely available on Mars. And, crucially this concrete can be formed without using water, which will be a precious resource on the red planet.
The key material in a Martian construction boom will be sulphur, says the Northwestern team. The basic idea is to heat sulphur to about 240 °C so that it becomes liquid, mix it with Martian soil, which acts as an aggregate, and then let it cool. The sulphur solidifies, binding the aggregate and creating concrete. Voila—Martian concrete.
Of course, the idea of using sulphur to bind aggregates is far from new. Engineers have been experimenting with this kind of material for at least a century and initially found that sulphur-based concrete had its fair share of problems.
For a start, as sulphur cools, it solidifies to form monoclinic sulphur and then transforms into orthorhombic sulphur, the stable allotrope at lower temperatures. But it also shrinks during this process and this shrinking creates cavities and sets up stresses that severely weaken the material. […] | Yes |
Are ionic minerals or colloidal minerals better? What do those terms mean anyway? Marketers of both types of products make claims that they are “more absorbable” than other mineral forms. But are they really? In this article, we examine definitions, how well the claims stack up, and what is just hype. This article begins each section with definitions, followed by discussion in conversational terms.
Minerals and Trace Minerals: A Clarification of Definitions
Naturally occurring inorganic elements having a characteristic crystalline structure and chemical composition.
Sometimes also called major minerals are those which the body requires more than 100 milligrams of per day for proper maintenance of health.
Also called trace elements, are those minerals which the body requires less than 100 milligrams of per day.
An atom or group of atoms that are inherently either positively or negatively charged due to either additional or missing electron(s). This charge causes the ions to interact, attracting or repelling each other in a search for another ion to join with or to give up an electron in order to make the charge neutral1, 2.
Of, containing, or relating to an ion or ions.
A substance whose molecules split into individual ions when dissolved, thus allowing it to conduct electrical energies1.
Related article: Trace Mineral Deficiency – 9 Facts you Need to Know
Overall discussion about ionic minerals:
The fluids of the body are largely solutions of ionic minerals, and there is not a process in the body that does not depend on ions. Minerals and trace minerals are capable of remaining in a free flowing, non-bound ionic form in a balanced solution. In the stomach, the body breaks down some other forms of bound minerals and trace minerals and converts them into their ionic form so they can be absorbed.
The body uses the movement of ions through these fluids and across cell membranes. It is fascinating to study because the ions conduct electricity throughout the body, and the ions regulate the body’s acid-base balance while also maintaining its water balance. In lay terms, ions tell a cell whether to let water into the cell membrane. This is why electrolyte salts are so important for hydration. Without electrolytes, water simply doesn’t get inside the cell.
Ions also serve essential roles in nerve conduction, muscle contraction, heart action, blood clotting, protein metabolism, bone and tooth formation, and enzyme activation.
Related article: Liquid Trace Minerals – How to Judge a Mineral Product
Colloidal Mineral definitions:
A suspension of tiny non-soluble mineral and trace mineral particles in water. Most colloidal minerals are held in suspension by their tiny size and/or a static electrical charge.
Click here to read a definition and discussion of colloidal minerals on WebMD.
We liked this background info from the website, “Science Clarified:”
Colloids are common in everyday life. Some examples include: whipped cream, mayonnaise, milk, butter, gelatin, jelly, muddy water, plaster, colored glass, and paper. Colloids can be made from almost any combination of gas, liquid, and solid. The particles of which the colloid is made are called the dispersed material. Any colloid consisting of a solid dispersed in a gas is called a smoke. A liquid dispersed in a gas is referred to as a fog.
Discussion related to Colloidal Minerals:
Every colloid consists of two parts: (1) colloidal particles and (2) the dispersing medium. The dispersing medium is the substance in which the colloidal particles are distributed. In muddy water, for example, the colloidal particles are tiny grains of sand, silt, and clay. The dispersing medium is the water in which these particles are suspended.
Regarding hype around whether colloidal minerals are better than ionic, one might ask, is mud inherently healthier for a human to eat than, say, sea water?
Many colloidal minerals claim to be organic due to the fact that they come from prehistoric mineral deposits such as humic shale and that some of the minerals are bound to carbon. We find it interesting that by this definition of organic, coal and many petroleum products are also organic. Any discussion about a mineral being “organic” is a distraction. In food products, “organic” has come to mean lacking pesticides and pollutants. Hence, someone might think of “organic” as being healthier, but from a chemistry definition, minerals are inherently “inorganic.” A person might consume minerals that are found in, say, a vegetable, (hence the source is organic) but that does not mean the minerals themselves are organic. It just means the plant took those minerals up from the soil.
A Caution about colloidal mineral products: Many colloidal trace mineral products (even though not represented on the label) have aluminum and phosphate as their two most prominent elements.
Practical differences between Colloidal and Ionic Minerals:
In addition to comparing the definitions of the two forms, one important comparison is size. Here we use magnesium as an example to illustrate this point.
The size of a magnesium ion is 1 X 10-6 microns. Compare this with the average colloid particle, which is 1 micron. If we were to make a model of a magnesium ion with a one millimeter (mm) radius (about the size of a very small BB—ball bearing), and then if we made a comparable model of a colloid to the same scale, then the colloid model would have to have a radius of one kilometer (km).
Which one would you imagine the body could most easily absorb? Likely, the stomach acid would be able to help dissolve some of the colloid, but ions are already broken down into their smallest atomic size. They also already have a natural charge, that aids in digestion. This makes them available for im | Yes |
Materials Design Of Triboelectric Nanogenerators For Biomechanical And Environmental Mechanical Energy Harvesting
Santa Clara Convention Center, CA, USA
Grand Ballroom D
09:40 - 10:00
The technology was conceived at the University of Wisconsin-Madison lab for advanced materials for energy and electronics under the direction of Professor Michael Arnold. The impact of nanomaterials on society has often been limited because it is difficult to synthesize, purity, process, organize, and integrate nanomaterials and nanostructures. Our research especially draws from multiple disciplines to address fundamental materials challenges - in controlling the growth, processing, ordering, and heterogeneity of nanomaterials and in understanding phenomena beyond the scale of single nanostructures - that must be overcome to exploit these exciting components in technology. | Yes |
The registered strap design, conceived and engineered for strength and security, combines two material layers: an alligator strap and a 316L stainless steel mesh bracelet incorporating three microns of black titanium carbide.
What does TIC stand for?
TIC stands for Titanium Carbide
This definition appears very frequently and is found in the following Acronym Finder categories:
- Science, medicine, engineering, etc.
See other definitions of TIC
We have 356 other meanings of TIC in our Acronym Attic
- Third International Conference (various organizations)
- Threat Intelligence Community
- Three Island Crossing (Idaho State Park)
- Throttle Input Command
- Tijdschrift voor Industriële Cultuur (Dutch: Journal of Industrial Culture; Belgium)
- Time In Class (US State Department)
- Time Interval Counter
- Time Is Capital
- Timing Interface Card (Sycamore)
- To Improve Conditions (club)
- Toaster Input Controller (Cisco)
- Together in Christ
- Token-ring Interface Coupler
- Tokyo International Center (Tokyo, Japan)
- Top of Inner Casing (monitoring wells to denote measuring point)
- Toronto International Centre (Canada)
- Toshiba International Corporation Pty. Ltd (Australia)
- Total Inorganic Carbon
Samples in periodicals archive:
Other companies quickly hopped aboard the bandwagon, and in addition to tungsten carbide, titanium nitride and titanium carbide inserts are also used by various die makers.
Summary: TEHRAN (FNA)- Molybdenum disilicide nanocomposite powder was produced successfully in Iran Materials and Energy Research Center, in addition to titanium carbide.
Until now, only a few carbide coatings such as titanium carbide and titanium carbon nitride (2) have been investigated and used in cutting tools.
The results also show that of the stresses are higher in the coatings of titanium nitride in comparison with titanium carbide and, correspondingly, the critical thickness of the titanium nitride coatings also lower.
A tungsten carbide wedge is used for aluminum wire, and a titanium carbide wedge is used for gold wire.
This competition-style bodywork has been given a black titanium carbide treatment to avoid any scratching in case of impacts.
Titanium carbide and aluminium oxide are very hard materials, providing wear resistance, and chemically inert, providing a chemical and heat barrier between tool and chip (Sandwik Coromat, 1994). | Yes |
Definition of sperrylite
n. - An arsenide of platinum occuring in grains and minute isometric crystals of tin-white color. It is found near Sudbury, Ontario Canada, and is the only known compound of platinum occuring in nature. 2
The word "sperrylite" uses 10 letters: E E I L P R R S T Y.
No direct anagrams for sperrylite found in this word list.
Words formed by adding one letter before or after sperrylite (in bold), or to eeilprrsty in any order:
s - sperrylites
All words formed from sperrylite by changing one letter
Browse words starting with sperrylite by next letter | Yes |
Products & Informations
Natural Anethole is extracted from the essential oils, such as anise oil.
It appears white crystalline or liquid with anise odor and sweet taste.
Natural Anethole is mainly used as flavor in food.
APPLICATIONS & USES
1. used as food and beverage flavor
2. widely used in the fragrance formulation of toothpaste and gargle
3. used as an odorant and odorant-correcting agent for medicines
4. used as sensitizer for color photography
5. used as a medicine to treat leucopenia caused by chemotherapy or radiotherapy and leucopenia caused by other reasons
6. used in cosmetic industry
7. used as an promising insecticide
Packing in 180kgs galvanized steel drum | Yes |
Replacement of H-bonded bridged water by transition metal ions in poly(1-vinylimidazole-co-methylmethacrylate) copolymers: A vibrational spectroscopy study using mid-FTIR, far-FTIR and ab initio calculations
Artikel i vetenskaplig tidskrift, 2012
A detailed structural analysis of the vibrational spectra of hydrophobic PVM (poly(1-vinylimidazole-co-methylmethacrylate)) copolymers PVM-4 (4 wt% 1-VIm) and PVM-44 (44 wt% 1-VIm) is provided with respect to bridging water and subsequent replacement by bridging transition metal ions. PVM-44 (44 wt% 1-VIm) with a high fraction of 1-VIm forms water bridges as evident by the water bending vibration, which is shifted up to 1665 cm(-1). This band vanishes as transition metal ions are introduced and a new band at 952 cm(-1) appears which is ascribed as a delta(ring) band involving the entire [M(Im)(n)](2+) unit. This fact is affirmed using ab initio calculations. The transition metal ions coordinate exclusively the imidazole groups. Although the imidazole associated water is replaced by transition metal ions, the amount of sorbed water for the very hydrophobic PVM-4 is increased as indicated by the nu(OH) region.
B3LYP hybrid functional | Yes |
Jasmine & Lilac Mini Favour Handmade Soap 45g
Heyland and Whittle are one of the largest manufacturers of cold-processed soap in England.
Using the unique Heyland & Whittle recipe, only the purest ingredients, including a vast array of essential oils, herbs and spices, are blended to create these handmade soaps. Heyland and Whittle use only natural colouring such as madder root, walnut leaves, nettle leaves and turmeric.
The creamy texture of the soap bars gently cleanses and nourishes all skin types and are
Summer Berries, Oranges and Lemons blend with an euphoric bouquet of Jasmine, Lilac and Lavender to evoke the enchanting smell of summer
- 45g soap bar
- Parabens & Sulphates free
- Suits all skin types
Olea europaea (Olive) oil, Aqua, Cocos nucifera (Coconut) oil, Elaeis guineensis (African palm) oil, Sodium hydroxide, Caprae lac (Goats Milk), Ricinus communis (Castor) seed oil, Simmondsia chinensis (Jojoba) seed oil, Limonene*, Theobroma cacao (Cacao) seed butter, Citral*, Geraniol*, Linalool*, Parfum * Naturally occurring in essential oils. | Yes |
Standard Rigidizer is an economical alternative to Freeze Proof Rigidizer.
Caution:Freezing destroys Standard Rigidizer. It solidifies, permanently.
We can only ship 'Standard' Rigidizer in warm weather.
- Kaowool Rigidizer is a popular colloidal silica compound for treating surfaces of ceramic fiber refractory products (Inswool, forge insulation blanket). It provides a degree of surface stiffness, resistance to erosion, and protection from compression during coating with castables (if performed).
TIP: Use in conjunction with ITC 100 HT.
- While Rigidizer can't fully withstand metal welding heat, it helps give wool integrity resisting compression which would permanently diminish performance.
- It is very popular when applying coatings like ITC 100HT, and ITC 296A.
- Application of the famous ITC 100 ceramic reflective paint coating to Kaowool (or similar) is simply easier after it is rigidized. (It makes it less like trying to paint cotton balls).
- ITC itself is rated to 5000 °F, and by reflecting the heat from the surface of the wool, a typical 40% increase of forge efficiency, burning less fuel, & shortening heat up time.
- ITC further preserves the properties of the Rigidizer and the thermal wool by mitigating the heat transferred from the firebox.
- Surface coating for ceramic fiber blanket and modules exposed to high-velocity gases.
- Surface treatment for vacuum-formed fiber shapes to increase surface hardness.
- Increases surface hardness and resistance to erosion.
- Easily applied by brushing or spraying, a little goes a long way.
Size Options Available:
- 250 ml bottle - spray top
- 500 ml bottle - capped or spray top
Click here for Rigidizer SDS. | Yes |
Cappuccinos, lattes, and flat whites all require textured milk. Without foamed milk we wouldn’t get that smooth mouthfeel and the rich body we enjoy. But do you know what is happening when you use the steam wand?
Milk undergoes structural changes at the chemical level when we foam it. Read on to find out more about why milk foams and what is happening when it does.
You may also like How to Include Non-Dairy Milks in Your Coffee Shop Menu
Milk in an espresso cup.
The Chemical Composition of Milk
Milk is a key ingredient in any coffee shop and a significant part of many espresso-based drinks. By better understanding what happens when we foam it, we can improve our chances of preparing a quality cappuccino.
Cow milk is a nutrient-rich and complex liquid that is mainly water but also contains several hundred chemical compounds. These components can be divided into four groups: proteins (1–20%), lipids (2–55%), carbohydrates or sugars (lactose 0–10%), and minerals.
Bottles of milk in Tehran. Credit: Mehrshad Rajabi.
Understanding Milk Proteins
Proteins are the components most affected by heating and that have the most impact on the success or failure of foamed milk. Let’s take a closer look at them.
Generally, proteins can be defined as molecules made of one or more long chains of amino acid residues that are bonded together by polypeptide bonds.
Maybe that’s too much science for you, but it doesn’t really matter whether you understand this. The important part is that milk contains proteins with different structures and sizes that are dispersed throughout the liquid.
There are two groups of milk proteins: caseins and whey proteins. They have different structures and behave in different ways under stress conditions. So they do different things when you heat and foam them.
Adding milk to a coffee.
A protein’s structure is simply the way that its atoms are arranged. Casein proteins present in milk in form aggregates called micelles. Those micelles consist of ????-, ????- and ????-caseins, which are proteins with primary structure.
Whey proteins (mainly β-lactoglobulin and α-lactalbumin) are globular proteins with well-defined tertiary and secondary structures.
In short, casein has a simpler structure than whey proteins. And this difference has a direct impact on the way the two groups of protein behave when you introduce them to a steam wand.
A glass of coffee with latte art. Credit: Becca Tapert.
Caseins are much more thermally stable than whey proteins. In other words, caseins keep their structure better when heated.
Whey proteins have more complex 3D structures, which unfold when heated. They start to do this at 40oC (around 104°F).
During this process, which is known as denaturation, whey proteins irreversibly lose their structure. They will always function differently after.
A barista steams milk. Credit: Jordan Madrid.
How Heat Affects Milk
Any heating affects the chemical structure of milk proteins. But how much it impacts the milk depends on the temperature and the duration of heating.
Let’s assume that you’re using pasteurised milk in your coffee shop. The pasteurisation process means that the milk was heated at 72–80 oC (around 162–176°F) for 15–30 seconds before it gets to you.
Pasteurisation denatures some whey proteins, but because the heating process is kept short, it doesn’t affect all of them.
And the reason that ultra-heat treated or scalded milk tastes different is because a sulphurous flavour develops during heat treatment.
Creating latte art with steamed milk. Credit: Tyler Nix.
But back to those proteins, because they are what will make your foam a success or a failure.
In milk’s natural state, reactive chemical groups are buried within the complex structures of whey proteins. Those groups become exposed when the whey protein unfolds during heating.
Because those chemical groups are reactive, they form new bonds within the unfolded structure and with other milk components. And this has an effect on how milk foams.
Pouring a tulip with steamed milk. Credit: Kat Stokes.
How Does This Impact Milk Foaming?
So what does all this science mean for your cappuccino?
When we foam milk, we are forcing water vapour and air into milk while heating it. The proteins create spheres around the air and stabilise into bubbles.
The protein chains in milk are polar: one end is hydrophilic (attracted to water), and the other is hydrophobic (repelled by water). When the proteins unfold during denaturing, they expose their ends and the hydrophobic ones try to get away from the water in the milk.
This means that within each air bubble, the hydrophobic ends are all pointed inwards, towards the water-free interior. The hydrophilic ends are exposed to the watery milk environment that the bubbles are suspended in. This structure helps keep the air bubbles intact.
Learn more in Coffee Science: Everything You Need to Know About Milk
A barista creates latte art.
When milk is foamed between 30oC and 40oC (86–104oF), it is unstable. Large air bubbles forming within a few minutes. Raising the temperature to 60oC (140oF) results in more stable foam and improvement of texture and density. Smaller and better-dispersed air bubbles are formed at higher temperatures.
Fat plays a role in stabilising these bubbles. At temperatures above 40oC (104oF) all of the lipids in milk melt. This liquid fuat helps prevent air bubbles from coalescing (joining together to create a large air pocket) by creating a film on the surface of the air bubbles.
Pouring steamed milk into a coffee. Credit: Tim Wright.
But be careful of heating the milk to too high of a temperature. Not only does scalded milk taste sulphuric, but you will reach a point where the foam will fail.
Proteins in their natural state cover the air bubbles and help to protect them from coalescence. If you continue to heat the milk, more of the proteins will denature and there will not be enough left in their organic state to stabilise the air bubbles.
This is why you can’t refoam milk – after reheating, there won’t be enough proteins with organised structures to create the stabilising layer.
A latte art tulip. Credit: Drew Coffman.
It may seem like milk with more fat content would be better for consistently stable foam. But butterfat, the main type of fat found in milk, is a large and heavy globule.
More than 95% of total milk lipids is in globules ranging from 0.1 to 15 µm in diameter. The fat content can be so large and heavy that it weighs down air bubbles, making foam collapse. Fat can also mask other flavours, meaning you could lose some of the flavour notes of your specialty coffee if you pair it with cream.
But before you reach for the skimmed milk, remember that fat is what gives you the smooth mouthfeel that is so appealing in a cappuccino or latte.
Adding cold milk to a glass of coffee. Credit: Alberto Bogo.
What Does This Mean For You?
When selecting milk for espresso-based drinks, the key thing to consider is the protein content. Without proteins, your milk won’t foam. Barista milk is a specific product that has high protein content for this reason. But you can use regular milk if you’re careful about the temperature.
The ideal temperature to foam milk is between 60–63oC (140–145oF). Below this, you will get unstable foam with large bubbles. Above this, too many of the proteins will denature. There will not be enough left in their organic state to stabilise the bubbles.
And skimmed milk will give you the most stable foam, but may not have the creamy mouthfeel you desire. Compromise with a semi-skimmed or half-fat milk for reliable foam with rich mouthfeel.
Pouring steamed milk into an espresso-based drink. Credit: Trent Erwin.
Understanding the chemical composition of milk can help create a better espresso-based drink. Through recognising how milk proteins work, you can be sure to avoid your foam falling flat.
Why not grab the steam wand and put your new knowledge to the test with a cappuccino?
Enjoyed this? Check out How to Choose The Best Milk Jug for Steaming & Latte Art
Written with support from Dmitriy Koriukin. Feature image credit: Becca Tapert.
Perfect Daily Grind
Want to read more articles like this? Sign up to our newsletter! | Yes |
procedure has been developed and tested for the analysis of small water samples, using particle-induced X-ray emission (PIXE) for soluble and insoluble elemental constituents separated by Nuclepore filtration. Nanogram sensitivity for samples in the 0.17-cm2 target area of a Van de Graaff accelerator proton beam permits the simultaneous determination of ~15 elements from A1 to Pb in the solids on a filter and by evaporation of a few milliliters of water on thin Mylar film. Rainwater from Tallahassee, FL, contained Al, Si, Ti, and Cr exclusively in the insoluble fraction while S, K, Ca, Ni, Cu, Zn, and Br were present principally as soluble elements. Fe and Pb were more evenly distributed between the two fractions. Surface-water samples in the Tallahassee area, from a lake and rainfall runoff from two shopping centers, showed qualitatively similar partitioning of the elements between the two fractions, although with a tendency for greater proportions to be insoluble.
ASJC Scopus subject areas
- 化学 (全般) | Yes |
A study has revealed that bottled water drinks are contaminated with micro plastics, could this also be the case for other drinks like Coke and Pepsi? and other drinks in plastic bottles?
The contamination was from the bottling process and the contamination was likely to be from the cap.
Plastics found inside the water bottles were double that found in normal tap water, however the World Health Organisation has come out and stated that there is no evidence to suggest people who drink bottled water was at risk.
The lids of bottles is made of a plastic called PET or polyethylene terephthalate and can be found on many other plastic bottles and even cartons, polypropylene was also found in the bottles of water from brands like Evian and Aqua.
The world needs to get a grip of all the plastics we have, the oceans even our rivers are full of micro plastics that stick around for decades, harming aquatic life. | Yes |
Chemie Ingenieur Technik, Vol.92, No.4, 395-404, 2020
Recycling of Phosphorus by Co-processing Sewage Sludge Ash in Phosphoric Acid Production
The approach of recycling phosphorus from sewage sludge ash by co-processing in conventional phosphoric acid production was investigated. Lab-scale experiments with real ashes and simulated industrial conditions showed that mixing of ash and phosphate rock prior to processing resulted in several disadvantages. As a solution the novel concept of return acid extraction is presented, which overcomes some of the identified shortcomings of direct mixing. | Yes |
Please use this identifier to cite or link to this item:
|Title:||Electrochemical properties of nitrogen-enriched templated microporous carbons in different aqueous electrolytes||Authors:||Tian, X.
|Issue Date:||2012||Citation:||Tian, X., Zhang, L.L., Jiang, Z., Luo, L. (2012). Electrochemical properties of nitrogen-enriched templated microporous carbons in different aqueous electrolytes. Advanced Materials Research 571 : 27-37. ScholarBank@NUS Repository. https://doi.org/10.4028/www.scientific.net/AMR.571.27||Abstract:||Ordered microporous carbon materials with controlled chemical and physical properties were synthesized by one-step nanocasting process using different carbon precursors. Large amount of heteroatoms, particularly oxygen and nitrogen species were presented in the carbon matrix. The interactions between the electrolyte ions and the surface functionalities were investigated in detail under various electrolyte environments. The electrochemical studies have revealed that different pseudo-processes occurred in proton-rich and proton-free electrolyte solutions. In proton-rich electrolyte environment, the faradaic processes are mainly due to the proton exchange between the nitrogen and oxygen species on the carbon electrode with the electrolyte. On the other hand, in proton-free electrolytes, nitrogen species was shown to play very important role in terms of the adsorption/desorption of K+ ions when negatively polarized in K+ containing electrolytes. The faradaic interaction between K+ ions and the nitrogen functionalities are stronger at the more negative potential. Very high gravimetric capacitance of 452 F/g and large capacitance retention of 97% at high discharge rate was achieved by the nitrogen-enriched carbon with moderately developed surface area. The superior capacitive performances of the templated carbons are closely linked to the ordered hierarchical porous structure, the adequate microporosity as well as the presence of suitable surface functionalities. © (2012) Trans Tech Publications, Switzerland.||Source Title:||Advanced Materials Research||URI:||http://scholarbank.nus.edu.sg/handle/10635/90538||ISBN:||9783037854884||ISSN:||10226680||DOI:||10.4028/www.scientific.net/AMR.571.27|
|Appears in Collections:||Staff Publications|
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Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated. | Yes |
Pure molybdenum has a high purity above 99.95% because only fine-grained and high purity powders are used as our raw material. Depending on specific required diameter, usually molybdenum rods are deformed by further rolling, swaging, or forging.
Size:Diameter 2mm - 150 mm Length up to 3000 mm
ASTM B387 - 10
- Anyang Daguan Metal Material co. Ltd
- Luoyang Modi Tungsten & Molybdenum Material Co., Ltd.
- Hebei Chuangli Electromechanical Technology Co.,Ltd
- Luoyang Shenyu Molybdenum Co.,Ltd
- Dalian Jinchangtai Machinery Manufacturing Co., Ltd.
- Zhengzhou SONGMINGXIANG Aluminum Foil Co.,ltd
- Firmetal Co., Ltd.
- Puyang Zhongshi Group Co.,Ltd
- Hangzhou Guozhen Wanxin Coating Equipment Manufacturing Co.,LTD
- GuangYE Stainless Stee Co.,Ltd
- Sichuan Dongtai Casting Industry Co.,Ltd.
- Zhejiang Litai Metal Co.,Ltd
Molybdenum Rod,Molybdenum bar
- Company Profile
- Product Brand
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- Fax Number
- Post Code
- Online Map
Related Trade Leads | Yes |
Notes - notes.io
You may reach for that bottle of chemical drain cleaner under your sink when you have a stubborn plumbing clog to deal with. I mean, it's just another cleaning product, right?
Not exactly. We'll examine in detail how chemical drain cleaners work along with the potential risks they pose to your plumbing.
HOW WORK THE CHEMICAL DRAIN CLEANERS?
In regards to chemical drain cleaners, the average shopper is unaware of two types:
To clear clogs, oxidizing drain cleaners do a combination of things. Using nitrates, you can dissolve organic matter stuck in a clog while releasing gas and heat that helps loosen grease and dislodge the blockage.
Drain cleaners that use hydroxide ions and alkaline chemicals use a slightly different process. In combination, the ions and chemicals create heat and transform the blockage into a soapy, sudsy substance.
ARE CHEMICAL DRAIN CLEANERS DANGEROUS?
It is important to emphasize that unlike the spray that degreases your stove or the liquid cleaner that cleans your toilet bowls, chemical drain cleaners can produce potentially hazardous chemical reactions. In my opinion, any substance capable of melting organic matter or creating a lot of heat extremely fast is something you certainly won't want to splash on your face or body. Unfortunately, drain cleaners cause a number of accidents each year.
According to a retrospective review:
According to CDC estimates, chemical drain cleaners cause 3000 injuries annually in the United States.
The burns were caused by heat in one-third of the injuries.
In chemical drain cleaners, there are dangerous ingredients
Chemical drain cleaners are particularly dangerous to use because of two ingredients specifically: concentrated sulfuric acid and sodium hydroxide.
The fluid sulfuric acid is corrosive, and it will char any organic matter it comes in contact with, according to PubChem. A hot substance like this could severely burn your skin or eyes if it comes into contact with water.
Hydroxide of sodium is another highly corrosive substance. As a solid at room temperature, it releases a great deal of heat when dissolved in water. In some cases, exposure to sodium hydroxide can result in skin and mucous membrane irritation and hair loss.
CHEMICAL DRAIN CLEANERS: CAN THEY DAMAGE PLUMBING PIPES?
In addition to being unsafe, chemical drain cleaners can also cause damage to your house's plumbing. The caustic ingredients in drain cleaners slow down the breakdown of pipe materials. It is possible for this damage to happen quicker if the drain cleaner does not remove a clog.
If the drain cleaner doesn't clear the blockage, you then have two problems. The clog is still there, and now you have extremely hot, corrosive liquid sitting on top of it in your pipe. As a result of the intense heat and caustic chemicals, the pipe material can become more vulnerable to leaks.
CHEMICAL-FREE DRAIN CLEANING SOLUTIONS
Drain cleaning methods performed by a professional are not only safer and more effective than chemical drain cleaners, but they are also more efficient at removing clogs, especially deep down in the drains.
Plumbers can use a drain snake to clear the drain when it clogs occasionally. Alternatively, this technique is known as cabling or snaking.
When there is a lot of buildup in the drains and sewer line, hydrojetting is generally a better long-term solution. Using canduplumbing.com -strength machine, your plumber will guide a hose with high-powered water jets through your drains to clear out any blockages or debris.
Here's my website: https://canduplumbing.com/plumbing-services/drain-cleaning/
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Lewis Acid Catalyzed Synthesis of Multisubstituted Pyrroles
J.-Y. Wang, X.-P. Wang, Z.-S. Yu, W. Yu*
Lanzhou University, P. R. of China
20 November 2009 (online)
Described is an efficient synthesis of polysubstituted pyrroles by a reaction of phenyliodonium ylides with enamine esters catalyzed by BF3 diethyl etherate. The reaction was optimized in terms of solvent and the acidic catalyst, for example, triflic and trifluoroacetic acid both afforded good yields as well (in the range of 70%). The starting iodonium ylides are readily available from phenyliodoso diacetate and the corresponding dicarbonyl compounds. The substrate scope of both starting materials was well studied and the yields of products range from good to excellent. In the case of R¹ = CH2Cl, the overall yield was good but the reaction yielded, in addition to the chloropyrrole (R¹ = CH2Cl), to the corresponding hydroxy derivative (R¹ = CH2OH) in a ratio of 2:1. | Yes |
Watts Premier's Water Filtration Systems vary in the way they filter, from simple 2 stage systems to more in-depth Ultraviolet and Ultra Filtration Systems. Our 2 stage systems come with a Sediment and Carbon Block and will filter sand, dirt, and rust as well as trace amounts of chlorine.
Whereas the Ultra Filtration uses Hollow Fiber Filtration to filter out the smaller particles that cannot be caught by a sediment or carbon block. The Ultraviolet Systems will take it a step further and will kill any bacteria in your water.
No products found in this collection. | Yes |
Scanning Electron Microscopy (SEM)
An SEM image is formed by a beam of electrons focused to a few billionths of a meter that is swept across the surface of a sample in a series of stacked rows until a complete two
dimensional pattern is formed. As the beam strikes solid electrons are emitted from the specimen and those particles are collected to form an image. The image
shown on the right is therefore called a “secondary electron image” and shows the topography of a material magnified up to 100,000s of times!
Click to see a series of SEM images at progressively higher magnification. | Yes |
|Publication number||US5894854 A|
|Application number||US 09/195,501|
|Publication date||Apr 20, 1999|
|Filing date||Nov 19, 1998|
|Priority date||Nov 19, 1998|
|Also published as||WO2000043136A1|
|Publication number||09195501, 195501, US 5894854 A, US 5894854A, US-A-5894854, US5894854 A, US5894854A|
|Inventors||Samuel Lee Miles|
|Original Assignee||Miles; Samuel Lee|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (2), Referenced by (10), Classifications (8), Legal Events (9)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention is an improved composition for removal of cured paint from non-ferrous parts. More specifically, the present invention relates to an environmentally friendly method of cured paint removal with a composition that is 99% free of volatile organic compounds.
Automobile, Industrial and Aircraft exterior parts are painted to protect the substrates from corrosion and also to enhance the cosmetic appearance to help market the finished product. Most manufactures that apply paint finishes have a paint defect rate of 5% to as high as 30% of daily production. Many paint finishing manufactures can no longer afford to discard these parts with paint defects, most manufactures will strip the defective parts in a hot paint strip tank and recycle by repainting the parts. Prior art utilized many different compositions and methods for the removal of paint from many different substrates. The present invention offers an environmentally safe composition, with improved methods of stripping paint from non-ferrous substrates. Prior art paint stripping utilized heated, highly caustic, alkaline solutions as demonstrated by Murphy in U.S. Pat. No. 3,766,076 in 1973 and by Sullivan in U.S. Pat. No. 3,980,587 in 1976. The highly caustic paint strip compositions are not suitable or compatible for use to remove paint from non-ferrous metal parts. The caustic solutions will agressively attack most non-ferrous metal substrates such as aluminum, galvanized steel, copper, zinc die cast, chromium, and tin. Chlorinated volatile organic solvents were utilized to strip paint in U.S. Pat. No. 3,574,123 as described by Laugle in 1971. The present art utilizes volatile organic solvents, such as n-methyl 2-pyrrolidone as reported in U.S. Pat. No. 4,120,810 by Palmer in 1978 and glycol phenol ether or ethoxylated furfuryl alcohol in U.S. Pat. No. 4,619,706 as described by Squires, Hundley, Barry and Powell in 1986. The present technologies continue to utilize compositions containing volatile organic solvents which have been proven to attack our environments protective ozone layer.
The inventor discovered improved methods to chemically strip and remove paint from non-ferrous substrates with an environmentally friendly composition 99% free of volatile organic compounds. It has also been discovered that this method of removing paint from non-ferrous substrates does not adversely attack the soft metal surfaces. The invention will not harm highly polished aluminum surfaces, whereas many solvent containing and silicated compositions will stain polished aluminum surfaces. The invention has demonstrated excellent paint removal performance on many plastic parts that can withstand temperatures of 350 degrees Fahrenheit for 60 minutes. The invention will remove cured paint from ferrous substrates as well as non-ferrous and plated surfaces. The method or process of use requires a vented hot strip tank capable of 350 degrees Fahrenheit with adequate agitation. The invention is used as received, with no water or volatile organic solvent additive. The invention is a unique composition that exhibits 99% free of any volatile organic compounds, a flash point exceeding 400 degrees Fahrenheit, a boiling point exceeding 500 degrees Fahrenheit, a low vapor pressure and is safe for use to strip paint from non-ferrous substrates.
The present methods of paint stripping with a hot strip process involve the use of a very caustic solution normally with volatile organic solvent additives. As earlier discussed it is common knowledge that the highly caustic portion of the prior art technology compositions adversely attacks non-ferrous substrates. It is also common knowledge the volatile organic solvent additive portion of the prior art compositions adversely attack our environmental ozone protective layer.
The composition of this invention consists of;
a, a Nonionic Surfactant, Formula: C35H6401 1, Molecular Weight: 682(Average), Synonyms: An alkylphenol-hydroxypolyoxyethylene, CAS #: 127087-87-0, Name: Poly (oxy-1,2-ethanediyl), alpha- (4-nonylphenyl)-omega-hydroxy-branched in a range of 20%-80% by weight with between 40%-60% preferred.
b, a Non-Ferrous Metal Safe Alkaline Source: Triethanolamine-99%, Chemical Name: Alkanolamine, Ethanol, 2,2,2,-nitrilotris, CAS #: 102-71-6 in a range of 20%-80% by weight with between 40%-60% prefferred.
In accordance with this invention, it is discovered that at elevated temperatures of 350 degrees Fahrenheit with approximately 60 minutes dwell time, this composition will strip cured paint from non-ferrous substrates, including: Aluminum, Galvanized Steel, Zinc Die Cast, Copper, Brass, most plated surfaces and 350F thermal stable plastics without adversely affecting the parts surface quality.
This invention was tested for paint removal with the present automotive and industrial paint technologies. Paint tested was from PPG, BASF and DUPONT. Paint types were high solids enamel, solvent-borne, water-borne, one component clear, two component clear, tinted clear coat, prime coat, flexible and rigid urethanes and adhesion promoting primes.
The invention was observed at 350F, 60 minute immersion dwell time with the following non-ferrous substrates and multiple cured paint mixtures at 3mil paint film build. All paint was removed, parts were evaluated by weight loss and appearance A,B,C;
______________________________________ Solvent Solvent Borne Solvent Borne Urethane Clear Coat Mixture High Solids Enamel % Strip,Non-Ferrous % Strip, Wt. Loss % Strip, Wt. Loss Wt. LossSubstrate Appearance Appearance Appearance______________________________________Aluminum 100%, 0% 100%, 0% 100%, 0% Appearance-A Appearance-A Appearance-AGalvanized 100%, 0% 100%, 0% 100%, 0% Appearance-A Appearance-A Appearance-AZinc Die 100%, 0% 100%, 0% 100%, 0%Cast Apearance-A Appearance-A Appearance-ACopper 100%, 0% 100%, 0% 100%, 0% Appearance-A Appearance-A Appearance-ABrass 100%, 0% 100%, 0% 100%, 0% Appearance-A Appearance-A Appearance-APlastic 100%, 0% 100%, 0% 100%, 0% Appearance-A Appearance-A Appearance-A______________________________________
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|Citing Patent||Filing date||Publication date||Applicant||Title|
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|US6923873||Jan 18, 2002||Aug 2, 2005||Greensolv Environmental Products Inc.||Paint stripping composition and method of using the same|
|US7151080||Feb 14, 2005||Dec 19, 2006||Kolene Corporation||Composition for stripping coatings from substrates|
|US7759298||Dec 14, 2006||Jul 20, 2010||The Boeing Company||Thickened composition and method for removing adhesive residue|
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|US20040138077 *||Jan 18, 2002||Jul 15, 2004||Daniel Pageau||Paint stripping composition and method of using the same|
|WO2013117757A1||Feb 11, 2013||Aug 15, 2013||Atotech Deutschland Gmbh||Composition and method for removal of organic paint coatings from substrates|
|U.S. Classification||134/38, 134/29, 134/42, 510/413, 134/26|
|Nov 6, 2002||REMI||Maintenance fee reminder mailed|
|Nov 22, 2002||FPAY||Fee payment|
Year of fee payment: 4
|Nov 22, 2002||SULP||Surcharge for late payment|
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Effective date: 20110420 | Yes |
|Número de publicación||US6451059 B1|
|Tipo de publicación||Concesión|
|Número de solicitud||US 09/439,656|
|Fecha de publicación||17 Sep 2002|
|Fecha de presentación||12 Nov 1999|
|Fecha de prioridad||12 Nov 1999|
|Número de publicación||09439656, 439656, US 6451059 B1, US 6451059B1, US-B1-6451059, US6451059 B1, US6451059B1|
|Inventores||Victor F. Janas, Kevor S. Tenhuisen|
|Cesionario original||Ethicon, Inc.|
|Exportar cita||BiBTeX, EndNote, RefMan|
|Citas de patentes (26), Otras citas (3), Citada por (111), Clasificaciones (43), Eventos legales (5)|
|Enlaces externos: USPTO, Cesión de USPTO, Espacenet|
The present invention relates to resorbable ceramic fibers and scaffolds for use in biological application, and their method of production. Specifically, this invention relates to novel fibers and scaffolds, formed via a wet spinning technique, and useful as biological replacements for hard tissue.
Bone grafts formed of porous calcium phosphates (CaP) show potential as a scaffolding for the growth of new bone in applications such as spinal fusion, long bone fractures, non-union fractures, bone defects, and hip revisions. In present devices, the porosity is either randomly distributed, or the manufacturing techniques have limited ability to control pore size. Control of pore distribution and size may be advantageous in optimizing bone growth into the graft.
The present invention relates to novel bone implants and their use in bone repair and reconstruction. More particularly, it relates to resorbable ceramic fibers and scaffolds, formed via a wet spinning technique, and useful as biological replacements for hard tissue. Bone grafts are used in the repair of significant fractures, the treatment of skeletal tumors, spinal fusion, and the reconstruction of failed total arthroplasties. Autogenous bone, or autograft, is bone harvested from another location in the patient, and used as the graft. Autograft performs very well in the applications cited above. The disadvantages of autograft include the limited supply of excess bone in the patient, as well as the inherent risks of morbidity and recovery pain taken by performing a second surgery. Allograft, bone taken from another human, has the advantage of being in larger supply than autograft bone. However, the greater immunogenic response of allograft, and risk of viral contamination or risk of transmission of live virus to the recipient, have led to the decline in use of allograft bone as a bone graft material. Xenograft, or bone grafts taken from another species, often elicits acute antigenic response. In the vast majority of cases, xenograft fails in its role as a graft material.
Synthetic bone graft materials have been described in Bone Graft and Bone Graft Substitutes: A Review of Current Technology and Applications; Damien and Parsons; J. Applied Biomaterals, Vol. 2, 1991, pages 187-208, which is incorporated herein by reference. The ideal graft should be able to support a load equivalent to the bone that is being replaced, so that the newly formed bone can remodel to the same quality and dimensions of the original bone that is being replaced. Ideal graft is also osteoactive, enhancing the formation of new bone. This is achieved both by the chemical nature of the material, as well as the structure, or architecture of the graft. Structurally, the graft needs to be porous to allow for ingrowth of the new bone. Though no optimal pore size has been established, the size of the pores required for good bone growth is between 100 and 500 microns. The ability to tailor the pore size and distribution is also viewed as a method of enhancing bone growth. Load support can be achieved by having the supporting phase of the graft three-dimensionally connected.
The materials in bone graft substitutes include, but are not limited to, plaster of Paris (calcium sulfate, CaSO4. 1/2H2O) tricalcium phosphate (Ca3(PO4)2), hydroxyapatite (Ca10(PO4)6(OH)2), calcium phosphate cements, calcium aluminates, the family of Bioglass® (composed of SiO2, Na2O, CaO, and P2O5), apatite-wollastinite glass-ceramics (AWGC), polymers such as polymethylmethacrylate (PMMA) or polyhydroxyethylmethacrylate (PHEMA), and blends of the above. They may be in the form of loose particles, particles bound in polymer or other carrier material (a paste), ceramic precursors that react when blended together (calcium phosphate cements), porous solids, or loose fiber constructs (such as felts), or textile processed fibers (weaves, braids, or knits).
The disadvantages of using loose particles as a bone graft include the difficulty of handling them, the tendency of the particles to settle (or pack tightly) into the defect, the inability of loose particles to support load, and particle migration away from the defect site in bodily fluids. Particle settling results in two problems. First, when the particles pack together, the pore size is reduced in the graft to less than 100 μm. This pore size does not allow the migration and ingrowth of cells into the graft. Particle settling also results in an inability to control the pore size and distribution in these systems. The size and distribution of pores in these types of grafts are determined by the size of the particles and how they pack together. Since settling is not controllable, there is no ability to use graft architecture to control new bone growth into the graft. Particle migration from the site results in possible tissue irritation and undesired tissue response in regions were the particles eventually settle.
Particle settling and migration problems have been mitigated to some extent by the use of synthetic or natural matrix materials, including polymers such as PMMA, polysulfone (PS), or polyethylene (PE), which are not resorbable, and ceramics, such as plaster of Paris or calcium phosphate cements. Particles have also been enclosed in tubes of resorbable polymers, such as collagen or polyglycolide. The size and distribution of pores in these types of grafts are also not controllable. The distribution is determined by the size of the particles, how they pack together, and the relative proportions of the matrix and particle phases. As with loose particles, there is limited ability to use graft architecture to control new bone growth into the graft.
For bone grafts in the form of cements, there is also a limited ability to control the pore size and distribution. Pore creating agents may be put into the cement prior to its formation. However, the size and distribution of pores are determined by the size, form, and concentration of the agent, resulting in the inability to use graft architecture to control new bone growth into the graft. This inability to control pore size and distribution also results in limits in load support capability. A random distribution of pores results in a random distribution of defects in the structure. So, although the load-supporting phase of the graft is three-dimensionally connected, these types of grafts have shown low load support capability. Control of the pore size and distribution in porous solid bone grafts is also limited. Porous solid bone grafts have been formed using the replamine process on naturally occurring coral. Here, the pore size and distribution is limited to that of the species of coral used. Defect location is also uncontrollable, lowering the load support capability of the graft in a fashion similar to that discussed above for cements. Pore creating agents may also be put into a ceramic prior to its formation. But, as is the case with cements, the size and distribution of pores are determined by the size, form, and concentration of the agent.
Bone grafts in the form of textile architectures, such as weaves, braids, or knits, have advantages over the other forms of bone grafts. Textile technology may by used to precisely place the fibers in a desired location in space, allowing for a large degree of control in the size and distribution of pores in the bone graft structure. However, since there is no interconnection of fiber in three dimensions, load support capabilities of grafts of this type are limited.
There are a number of woven structured formed with fibers composed of the materials found in bone graft substitutes cited in the prior art. Tagai et al., in U.S. Pat. Nos. 4,820,573, 4,735,857, and 4,613,577, disclose a glass fiber provided for the filling of a defect or hollow portion of a bone. In this case, the calcium phosphate glass fiber may be in the form of short fibers, continuous fiber, or woven continuous fibers. In this prior work, the load support capability of the graft is limited since there is no interconnection of fiber in three dimensions.
To increase the strength of the fibrous implants, bioresorbable fibrous constructs have been filled with polymers to form composite structures. Many of these have been cited in the prior art. U.S. Pat. No. 5,013,323, to Kobayashi et al., discloses an implant material for replacing hard tissue composed of calcium phosphate glass fibers in an organic polymer, where some of the glass fiber on the composite surface is exposed to the living tissue to promote bonding of the device to the tissue.
In U.S. Pat. Nos. 5,721,049, 5,645,934, and 5,468,544 (all to Marcolongo et al.), disclose composite materials formed from bioactive glass or ceramic fibers. The preferred embodiments are braids or meshes of bioactive glass or ceramic fiber interwoven with structural, non-bioactive fibers impregnated with a polymer to form a composite of suitable biocompatibility and structural integrity. The braid or mesh is designed so that the bioactive fibers are concentrated on the surface of the implant.
A method of producing biodegradable prostheses comprising a composite of resorbable fibers reinforcing a biodegradable matrix is disclosed in U.S. Pat. Nos. 4,655,777 (Dunn & Kasper), and 4,604,097 (Graves & Kumar). Both patents will be discussed in greater detail below. The fibers include ceramics, such as tricalcium phosphate, and a biodegradable glass. In this case, the fiber/polymer composite is made in the laminated form, and not as a woven structure.
The limitation of the composite approach is that by filling in the space between the fiber, the structures themselves are no longer porous. They are therefore unable to support the ingrowth of new bone. As discussed earlier, pore creating agents may also be put into the composite prior to its formation. However, as pointed out for earlier structures, the size and distribution of pores are determined by the size, form, and concentration of the agent.
The fibers produced in the patents cited above have a wide variety of compositions, and were formed by various techniques. In most cases, they are composed of mixtures of silicon dioxide (SiO2), aluminum oxide (Al2O3), calcium oxide (CaO), sodium oxide (Na2O), potassium oxide (K2O), lithium oxide (Li2O), magnesium oxide (MgO), zinc oxide (ZnO), strontium oxide (SrO), iron oxide (Fe2O3), titanium oxide (TiO2), zirconium oxide (ZrO2), calcium fluoride (CaF2), and phosphorous pentoxide (P2O5). These compositions are melt spun at temperatures between 800 and 1700° C. A discussion of the range of spinnable, degradable glass compositions, and how they are processed, is discussed in U.S. Pat. No. 4,604,097 (Graves & Kumar).
The bioresorbable ceramic fibers for use as the reinforcement phase in a laminated fiber/polymer composite discussed in U.S. Pat. No. 4,655,777 (Dunn & Kasper) were produced via a wet spinning technique known as the viscous suspension spinning process (VSSP). VSSP will be discussed in detail later. As mentioned earlier, these fibers are used in laminated form in fiber/polymer composites, and not as a woven structure. Wet spinning has been utilized to create heat resistant fibers (U.S. Pat. No. 4,976,884, to Delvaux and Lesmerises) by adding ceramic materials to the organic binder prior to fiber spinning. The wet spinning technique has also produced carbon fiber (U.S. Pat. No. 4,869,856 to Takahashi and Yagi) by heat treating the spun acrylonitrile fibers in a reducing atmosphere. Metal fibers (U.S. Pat. Nos. 4,118,225, and 4,104,445, to Dobo) and superconducting ceramic fibers (U.S. Pat. No. 5,100,049 to Hsu, and Goto and Tsujihara, in J. Mater. Sci. Letters, 7 238, 1988) have been formed by adding metal or ceramic powders to the binder, spinning the fibers, and heat treating the fibers in the proper environment to eliminate the binder and sinter the metal or ceramic powders. Hollow metal and ceramic fibers have also been produced by adding metal or ceramic powders to the binder as discussed above, spinning the fibers through a hollow tube spinerette, and heat treating the spun fibers as discussed above. Ceramic powders have also been added to rayon viscous precursor solution, and green (unsintered) fibers have been spun in the viscous suspension spinning process (VSSP).
The green VSSP fibers may be heat treated in the proper environment to eliminate the binder and sinter the ceramic, yielding a ceramic fiber. Many ceramic fibers, such as titanium dioxide, silicon carbide, zirconium oxide (French and Cass, in Ceramic Bulletin, 77 61, 1998, and Cass, in Ceramic Bulletin, 70 424, 1991), and lead zirconate titanate (McNulty et al. in J. Amer. Ceram. Soc., 78 2913, 1995) have been created this way.
As mentioned above, bioresorbable ceramic fibers for use as the reinforcement phase in a laminated fiber/polymer composite were produced via the VSSP process. In U.S. Pat. No. 4,655,777 (Dunn & Kasper), the forming of β-tricalcium phosphate (β-Ca3(PO4)2) and calcium aluminate (CaAl2O4) fibers is disclosed. The fibers were produced by extruding a mixture of ceramic powder, binder, and solvent into a bath containing a non-solvent for the binder. During extrusion into the non-solvent bath, the mixture coagulates to form a filament. These filaments are subsequently drawn down into fibers over a series of godets, rinsed to remove residual solvent, dried, and heat treated in an inert atmosphere to sinter the ceramic. As mentioned earlier, these fibers are used in laminated form in fiber/polymer composites, and not as a woven structure.
In summary, the prior art presents a number of methods for forming synthetic bone grafts. In all cases, the forming techniques lack the ability to tailor the pore size and distribution in the graft, and/or the ability to have the supporting phase of the graft three-dimensionally interconnected. Tailored pore size is viewed as a method of enhancing bone growth, while improved load support is achieved by a three-dimensionally connected supporting phase.
It is therefor an object of the present invention to provide a bone graft in which the pore size and distribution is tailored to enhance bone growth, and improved load support is achieved by a interconnected three-dimensional support phase.
Another object of this invention is to create structures to use as scaffolds for the in vitro or in vivo growth of human or animal tissue, such as bone or cartilage. These scaffolds can be used as implant materials for the replacement of defects or hollow portions of hard tissue resulting from external injury or surgical removal of hard tissue tumors. Their composition can be tailored such as to be resorbed by the body at a rate equivalent to the rate at which natural hard tissue grows into the above mentioned defects or hollow portions of hard tissue.
A still further object of this invention is the formation of laminated bioresorbable structures where each layer has controlled pore size and distribution. This type of structure has another degree of control for optimizing bone growth into the resorbable ceramic structure if the structure is used as bone graft.
We have discovered a process for making unified three-dimensional bioresorbable ceramic structures for use as bone replacement materials in which pore size and distribution are controlled. The structure is formed by first creating unfired (green) bioresorbable ceramic fibers via the viscous suspension spinning process (VSSP). Then, using common textile techniques, such as weaving, braiding, or knitting, a structure in which the size and distribution of interconnected pores are controlled, is created. Heat treating the structure to remove the organic phase and sintering the ceramic yields a hard tissue scaffold. The advantage of this work over biocompatible inorganic structures disclosed in the past is the ability to both control pore size and distribution for optimized bone ingrowth, as well as for a unified three-dimensional ceramic structure with load support capability.
FIG. 1 is a photomicrograph at low magnification of a woven bioceramic structure.
FIG. 2 is a photomicrograph of a section of FIG. 1 but taken at a higher magnification.
We have discovered a process for making novel hard tissue scaffold using the viscous suspension spinning process (VSSP) to create unfired (green) bioresorbable ceramic fibers. Textile techniques are used to create a structure in which the size and distribution of interconnected pores are controlled. Heat treating the structure to remove the organic phase, and sintering the ceramic, yields a resorbable hard tissue scaffold.
Formation of the scaffold starts with readily available bioresorbable inorganic powders with tailored resorption characteristics, such as hydroxyapatite, tricalcium phosphate, tetracalcium phosphate, or other amorphous or crystalline phosphate, or multi-phasic blends of resorbable glasses and/or sinterable ceramics. For polycrystalline ceramics, the powder used in the process is very fine (<10 μm granule size). This fine size is required for the firing step in the process. Granules of significantly larger size will not merge together to form fully connected fibers in the subsequent processing steps discussed below.
The powder is combined with compatible polymers or prepolymers, and then wet spun to form powder/polymer fibers. Compatible polymers are polymers that can be solution spun from a solution that is non-reactive with the powders described above and does not leave an undesirable residue on firing. Suitable compatible polymers include but are not limited to polyvinyl alcohol, polyethylene glycols, cellulose-based polymers, and natural polymers such as gelatin and guar gums. One such compatible polymer is Viscose. Viscose is prepared by taking sheets of cellulose obtained from wood pulp or cotton linters, shredding the sheets into crumbs, and mixing with solvents, such as water, until a solution is formed. In this work, the biocompatible powders were mixed into a cellulose/water solution containing sodium hydroxide in a high shear mixer.
Wet spinning is well documented for forming a number of organic, metal, and ceramics fibers. Most of the discussion below, although unrelated to the current invention, serves as a means of clarifying the types of fibers formed by the wet spinning process used in this invention.
Wet spinning has been used to make a number of organic fibers, including those composed selected from the groups consisting of cellulosics (rayon etc.), polyvinyl alcohols (U.S. Pat. No. 5,455,114, to Ohmory et al. incorporated herein by reference) polyesters (U.S. Pat. No. 5,451,359, to Yahata and Tsukamoto incorporated herein by reference) and combination thereof. In all cases, the polymer to be made into a fiber is dissolved in a solvent to create a spinning dope. The dope is passed through a multi-hole spinneret into a solidifying bath. The bath solidifies the dope into gel (no change in dope composition) or coagulate (change in dope composition) fibers. The same solidifying bath may also be used to remove the dope solvent in the fibers by extraction. The fibers are drawn down to a smaller diameter either in or out of the solidifying bath.
Residual solvent is removed in a series of washing and drying steps. The resulting fiber may or may not be further drawn down to a smaller diameter, if desired. Rayon fibers have been prepared by spinning a viscous solution (see, for example, U.S. Pat. No. 4,405,549, to Turbak and Hartmann, U.S. Pat. Nos. 4,388,260, 4,245,000, and 4,242,405, to Bockno).
In this work, inorganic/polymer fibers were created by passing the mixture of biocompatible powders in cellulose/water solution described above through a multi-hole spinneret into a solidifying bath. The bath solidified the mixture. The fibers were drawn down to a smaller diameter in the bath. Residual solvent was removed in a series of washing and drying steps.
At this point, the fibers, containing both inorganic materials and their organic binders, are formed into three-dimensional structures via conventional textile techniques such as weaving, braiding, and knitting. Textile technology is used to precisely place the fibers in a desired location in space, allowing for a large degree of control in the size and distribution of pores in the structures disclosed in this work.
As mentioned earlier, in biocompatible inorganic fibrous structures disclosed in the past, the fibers were not unified in a three-dimensional structure. Therefor, load support capabilities of these structures is limited. In this work, the structures are formed into three-dimensional structures in the green (unfired) state. Firing is accomplished by exposing the structures to temperatures sufficient to cause the removal of the organic binders by sublimation or oxidation, and the inorganics to bond in a process known in the ceramics field as sintering. When fired, the fibers will cross-sinter with one another, resulting in a three-dimensionally connected ceramic tissue scaffold structure in which pore size and distribution are controlled.
With this invention, there is opportunity for the formation of laminated structures, and a countless number of three-dimensional structures. The individual plies can be formed via textile operations such as weaving, braiding and knitting. Mixed fabric types can be incorporated into the structure for further control of pore size and distribution. Though no optimal pore size and distribution has been established, the size of the pores required for good bone growth is between 100 and 500 microns. The ability to tailor the pore size and distribution is also viewed as a method of enhancing bone growth.
The structures created by this invention may be used as scaffolds for the in vitro or in vivo growth of human or animal tissue, such as bone or cartilage. These scaffolds can be used as a novel implant material for the replacement of defects or hollow portions of hard tissue resulting from external injury or surgical removal of hard tissue tumors. Their composition can be tailored such as to be resorbed by the body at a rate equivalent to the rate at which natural hard tissue grows into the above mentioned defects or hollow portions of hard tissue.
In addition, the three-dimensional structure may be filled with resorbable synthetic polymers or biopolymers or ceramic materials that may or may not contain materials that promote bone growth through the device. These include autograft, allograft, or xenograft bone, bone marrow, demineralized bone (DBM), natural or synthetic bone morphogenic proteins (BMP's i.e. BMP 1 through 7), bone morphogenic-like proteins (i.e. growth and differentiation factor 5 (GFD-5) also known as cartilage-derived morphogenic factor 1, GFD-7 and GFD-8) epidermal growth factor (EGF), fibroblast growth factor (FGF i.e. FGF 1 through 9), platelet derived growth factor (PDGF), insulin like growth factor (i.e. IGF-I and IGF-II and optionally IGF binding proteins), transforming growth factors (TGF-βi.e. TGF-βI through III), vascular endothelial growth factor (VEGF) or other osteoinductive or osteoconductive materials known in the art. Biopolymers could also be used as conductive or chemotactic materials, or as delivery vehicles for growth factors. Examples could be recombinant or animal derived collagen or elastin. Bioactive coatings or surface treatments could also be attached to the surface of the device. For example, bioactive peptide sequences (RGD's) could be attached to facilitate protein adsorption and subsequent cell tissue attachment. Antibiotics could also be coated on the surface of the device or delivered by a material within the device.
The polymeric materials filling the device could exist in a number of phases including solids, foams, or liquids. The structure could be filled polymer to some specified degree to improve the mechanical toughness of the device. Foamed polymeric materials could be lyophilized within the structure providing a scaffold within a scaffold. The porous polymeric foam would provide an osteoconductive medium for bone growth into the device. The porous foam could also serve as a delivery medium for growth factors, peptides, and other bioactive materials.
The three-dimensional structure could also be filled with photocurable polymeric materials and cured in place with UV light source. It could also be filled with ceramic cements, monolithic ceramic materials or particles that are osteoconductive or inductive. The structure could also be post-processed with a ceramic or polymeric coating that is osteoconductive or inductive. The second ceramic material would act as a coating that would be different from the materials used for the main body of the scaffold.
The three-dimensional structure may also serve as a scaffold for the engineering of bone tissue to facilitate bone healing. The structure may have an internal porous structure that would be conducive to the growth of cells. As outlined in previous patents (Vacanti, U.S. Pat. No. 5,770,417), tissue can be harvested from a patient and the tissue can be sterile processed to provide a specific cell type (i.e., osteoblast, mesenchymal stem cell (Caplan, U.S. Pat. No. 5,486,359), etc.). The cells could contain inserted DNA encoding a protein that could stimulate the attachment, proliferation or differentiation of bone tissue. The three-dimensional structure would be placed in cell culture and the cells seeded onto or into the structure. The structure would be maintained in a sterile environment and then implanted into the donor patient once the cells have invaded the microstructure of the scaffold. The in vitro seeding of cells could provide for a more rapid healing process. Additionally, radio-opaque markers may be added to the scaffold to allow imaging after implantation. Without intending to limit it in any manner, the present invention will be more fully described by the following examples.
Particles of ceramic tricalcium phosphate, Ca3(PO4)2, with a BET surface area of 1.708 m2/gm, were milled in water containing a sodium silicate surfactant to create a dispersion. The dispersion was added to a viscose, which had previously been made by dissolving cellulose in a sodium hydroxide (NaOH) solution. The ratio of ceramic particles to cellulose in the mix was 70 to 30 by weight.
The mix was pumped through a 100-hole, 90-micron spinneret into a solution of sulfuric acid (H2SO4) which, after subsequent washes in mild acid solutions and water, yielded a tow of cellulose fibers highly filled with ceramic phosphate & sulfate particles.
Approximately 1 gram of yarn was placed on platinum foil, which in turn was put onto an aluminum setter plate, and placed in a high temperature furnace. The following heat treatment schedule was followed (under an air atmosphere): ramp from room temperature to 150° C. in 2 hours, hold 150° C. for 2 hours, ramp from 150° C. to 550° C. in 13 hours, hold 550° C. for 2 hours to allow for removal of the cellulose, ramp from 550° C. to 1050° C. in 2 hours, hold 1050° C. for 2 hours to allow for sintering of the ceramic particles, ramp from 1050° C. to room temperature in 4 hours.
The resulting ceramic fibers were examined under X-ray Diffraction and spectrochemical analysis to determine their chemical composition and crystalline structure. The analyses showed the fibers to be a multi-phasic blend of calcium sulfates, sodium sulfates, calcium phosphates, and sodium phosphates. By weight, the fibers were 52% SO4, 37% CaO, 4.5% P2O5, 3.6% Na2O, and approximately 3% of trace compounds such as SiO2 and ZnO.
Tows of cellulose fibers highly filled with tricalcium phosphate particles, made as described in Example 1, were woven into simple flat panels by hand. The weave pattern used was a simple “one over, one under” plain weave. Several of the weaves were placed on platinum foil, which in turn was put onto an aluminum setter plate, and placed in a high temperature furnace. The following heat treatment schedule was followed (under an air atmosphere): ramp from room temperature to 550° C. in 3 hours, hold 550° C. for 2 hours to allow for removal of the cellulose, ramp from 550° C. to 1050° C. in 2 hours, hold 1050° C. for 2 hours to allow for sintering of the calcium phosphate particles, ramp from 1050° C. to 550° C. in 4 hours.
The resulting ceramic scaffold was examined under Scanning Electron Microscopy (SEM). The scaffold maintained the woven architecture of the unfired weave. FIG. 1 is an SEM photograph of the woven structure. The figure shows the large pores (100-1000 μm) which have been associated with good tissue growth into a scaffold. FIG. 2 shows the same scaffold at a higher magnification. In this SEM, individual ceramic fibers are clearly visible, as are the fine pores (<100 μm) between the fibers. The fine pore structure could serve as a reservoir for natural and synthetic agents that promote bone growth into the scaffold.
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|Clasificación de EE.UU.||623/23.51, 623/23.56, 623/23.75, 623/23.76, 427/2.27|
|Clasificación internacional||C04B30/02, A61F2/30, A61F2/00, C03B37/01, A61F2/46, A61F2/28, C04B35/622, A61F2/02, C04B35/447, A61L27/12|
|Clasificación cooperativa||C04B35/62268, A61F2230/0063, A61F2002/30062, A61F2250/0023, A61F2/3094, A61F2002/30968, C04B2111/00836, A61F2310/0097, A61F2310/00293, A61F2002/2835, A61F2002/30199, A61F2/28, A61F2210/0004, C04B30/02, A61F2002/2817, A61F2002/3093, A61F2/30767, A61L27/12, C04B35/447, C03B37/011, A61F2002/30011, A61F2002/4648|
|Clasificación europea||C04B35/447, C04B30/02, A61F2/28, C03B37/01B, A61L27/12, C04B35/622F2P|
|27 Ene 2000||AS||Assignment|
Owner name: ETHICON, INC., NEW JERSEY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:JANAS, VICTOR F.;TENHUISEN, KEVOR S.;REEL/FRAME:010553/0636
Effective date: 20000120
|23 Feb 2006||FPAY||Fee payment|
Year of fee payment: 4
|26 Abr 2010||REMI||Maintenance fee reminder mailed|
|17 Sep 2010||LAPS||Lapse for failure to pay maintenance fees|
|9 Nov 2010||FP||Expired due to failure to pay maintenance fee|
Effective date: 20100917 | Yes |
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This review presents some of the hottest topics in biotechnological applications: proteases in biocatalysis. Obviously, one of the most relevant areas of application is in the hydrolysis of proteins in food technology, and that has led to a massive use on proteomics. The aim is to identify via peptide maps the different proteins obtained after a specific protease hydrolysis. However, concepts like degradomics are also taking on a more relevant importance in the use and study of proteases and will also be discussed. Other protease applications, as seem in cleaning (detergent development), the pharmaceutical industry, and in fine chemistry, will be analyzed. This review progresses from basic areas such as protease classification to a discussion of the preparation of protease‐immobilized biocatalysts, considering the different problems raised by the use of immobilized proteases due to the peculiar features of the substrates, usually large macromolecules. Production of bioactive peptides via limited hydrolysis of proteins will occupy an important place in this review.
|Authors:||Olga Luisa Tavano, Angel Berenguer‐Murcia, Francesco Secundo, Roberto Fernandez‐Lafuente|
|Journal:||Comprehensive Reviews in Food Science and Food Safety|
Abstract The single radial immunodiffusion assay has been the accepted method for determining the potency of inactivated influenza vaccines since 1978. The world‐wide adoption of this assay for vaccine standardisation was facilitated through collaborative studies that demonstrated a high ... more
Abstract Background Whether morbidity from the 1918‐19 influenza pandemic discriminated by socioeconomic status has remained a subject of debate for 100 years. In lack of data to study this issue recent literature have hypothesized that morbidity was “socially neutral”. Objectives ... more
Smart skin that can respond to external stimuli could have important applications in medicine and robotics. Using only items found in a typical household, researchers have created multi-sensor artificial skin that's capable of sensing pressure, temperature, humidity, proximity, pH, and air ... more
Some doctors may recommend that patients with the flu take acetaminophen, or paracetemol, to relieve their symptoms; however, a new randomized clinical trial found no benefits to the over-the-counter medication in terms of fighting the influenza virus or reducing patients' temperature or ot ... more
A new study that investigated the potential of certain psychological traits for predisposing heterosexuals to have negative attitudes towards homosexual people found that psychoticism - which is present in severe psychopathological conditions but may also contribute to less severe states of ... more | Yes |
Cramolin special sprays
Cramolin special-purpose sprays are dedicated to electronic and electrical components in industry, workshops and at home. Some special sprays allow for the removal of dust from the most complex and inaccessible parts, as well as to effectively and safely remove all deposits from various types of surfaces. Others enable the detection of faulty components and the testing of smoke detectors. Cramolin products are available as sprays in packaging of 200 ml and 400 ml. They are environmentally friendly and manufactured according to all standards. They stand out because of their high quality in relation to affordable prices. Special sprays include:
Cramolin freeze sprays allow quick location of faults in electronic equipment and other components through thermal shock. They do not react with other materials.
Freezer sprays are used to quickly locate faults in electronic components and systems using thermal method. They ensure reliable cooling down to -50° C. In this way, they quickly locate thermal intermittent components due to heat induced failure. The products are chemically pure, nonconductive and evaporate immediately without leaving residue. They are available in flammable and non-flammable versions. A frequent cause of faults in electronic equipment is thermal damage to contacts and printed circuit boards that is difficult to locate. Regular measurements are too time-consuming. Freezer cools an electrical circuit, allowing you to locate a break or damage to components. It can be used to test electronic components, thermostats in refrigerators and freezers, control systems, lamps, electronic carburettor components of automotive ignition systems and to remove chewing gum from fabrics. It is possible to cool individual components or to use as a spray to freeze pipes and screws.
Dust removers for cleaning electronics
Each dust remover for electronics consists of a mixture of dry gases that act like compressed air. This allows them to reach most inaccessible areas, where extremely pure cleaning of electronic components and equipment is required. They leave no residue and do not damage surfaces. Even up to 80% of equipment failures are caused by dirt.
Dust remover for cleaning electronics DUSTER-TOP (German name DRUCKLUFT-TOP) – NONFLAMMABLE. Capacity 200 ml and 400 ml.
Microscopically clean, moisture free, non-flammable.
Dust remover for cleaning electronics DUSTER BR (German name DRUCKLUFT BR) – FLAMMABLE. Capacity 200 ml and 400 ml.
Microscopically clean, moisture free, flammable.
Specially developed for use where thorough cleaning is required and ordinary products of this type are too weak. The strong jet of dry gas immediately removes dirt from the most inaccessible places. DUSTER products are used in industry, service equipment and households. They are recommended for non-invasive cleaning of sensitive electronic components and parts such as: data processing equipment, computer equipment, optical equipment, photography equipment, microscopes and laboratory equipment, magnetic heads, precision devices, printed circuit boards, watch mechanisms, banknote counters, telecommunications equipment, medical equipment, fibre optic connections and many other delicate devices.
Spray for cleaning electronic circuits BOOSTER. Capacity 500g. Does not contain ozone compounds.
Extra strong, non-flammable duster for professional cleaning of heavy duty contaminates at hard-to-reach areas. It has four times greater pressure than other sprays and evaporates immediately after application. The product removes dust particles, oxides, and dry dirt. It is recommended for electronic components such as: data processing equipment, photography equipment, laboratory equipment and microscopes, magnetic heads, precision devices, printed circuit boards, watch mechanisms, banknote counters, telecommunications equipment, medical equipment, fibre optic connections and computer equipment.
Label removers for cleaning electronics
This spray allows for the easy and quick removal of adhesive paper labels from all kind of material without damaging the surface.
Label remover LABEL-OFF (German name KLEB-EX). Spray 200 ml and 400 ml.
Spray which dissolves adhesive substances. It removes self-adhesive labels from all materials and surfaces. The strong solvents used in the product penetrate the paper and neutralizes the label’s adhesive strength. Residues of glue can readily be wiped off using a cloth or paper. The product acts directly on adhesive and is gentle on the surfaces to be cleaned. Only a few materials such as polystyrene may be attacked by the substance. The spray also removes natural grease, resin and fingerprints. Ideal for all applications where labels and label residues are removed: office equipment, IT equipment, labelling machines, packaging, household appliances, all plastics (except polystyrene), paper.
Smoke detector tester SDT-SPRAY SMOKE-DETECTOR-TEST-SPRAY (German name RMT-SPRAY). Spray 200 ml.
Ideal for professional testing of optical and photoelectric smoke detectors without using any additional test equipment. One spraycan of the product is sufficient for 200 applications. Smoke-detector-test-spray evaporates quickly without leaving any residue. It also does not contain silicone oils. | Yes |
Tartrazine (Yellow) Lake C435 1Kg
Bright yellow Lake food colour – Additive Number: 102. Lake Colours are oil soluble food colours suitable for colouring Chocolate etc.
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Sunset Yellow (Orange) C155 1Kg
Tartrazine (Yellow) Liquid Colour 1Ltr
Brilliant Blue Lake C410 1Kg
Allura Red C100 1Kg
Green Apple Liquid Colour C320 1Ltr
Green C410 1Kg
Strawberry Red 30% C260 1Kg
Orange Liquid Colour C323 1Ltr | Yes |
The Surface Dynamics Group carries out research within the fields of surface astrophysics and nanoscience. Special emphasis is on the interaction of atomic hydrogen with carbonaceous materials for interstellar chemistry and hydrogen storage, control of surface conductivity via hydrogen patterning of graphite/graphene surfaces and the formation of pre-biotic molecules under interstellar conditions via surface catalysis and interaction with polycyclic aromatic hydrocarbons.
The group combines Scanning Tunnelling Microscopy (STM) techniques with molecular beams, thermal desorption spectroscopy, X-ray Photoelectron Spectroscopy (XPS), and laser desorption and detection techniques under ultrahigh vacuum conditions and at both He cryogenic and higher temperatures.
The surface dynamics group is home to ERC Consolidator Grant "GRANN", coordinator of Innovative Training Network "EUROPAH", and part of the "Villum Centre of Excellence for Dirac Materials".
The group has laboratories at the Department of Physics and Astronomy and the Interdisciplinary Nanoscience Center (iNANO) at Aarhus University and is part of the Aarhus University Centre for Integrated Materials Research (iMAT). | Yes |
RAMOS RS120 compact Raman dual-channel spectrometer is a standalone research instrument designed to perform spectral measurements with capabilities at the level of high-end systems. Spectrometer RAMOS RS120 has a rigid, moving parts free design that does not require adjustments, has both high sensitivity and high spectral resolution, and can be equipped with one or two single-mode lasers 488/633 nm or 532/785 nm simultaneously. RAMOS RS120 can be equipped with Raman fiber optic probes. A wide range of capabilities, high reliability, and compact size allow using RAMOS RS120 for various scientific and industrial applications. The objects for complex research can be semiconductors, minerals, polymers, pharmaceutical and biological substances, coatings, and other materials. RAMOS RS120 spectrometer can be equipped with either built-in 532 nm or 785 nm laser or both lasers simultaneously. 488/633 nm lasers are available on request. | Yes |
Carbon Coated Urea™ is a coated slow release granular fertiliser.
Our formulation (Cabon Coated Urea as Carbon King™) is the only Carbon Coated Urea™ product on the market with 46 Urea and 21 carbon ratio.
Carbon Coated Urea™ Key Points:
- Less loss of nitrogen
- Carbon Coated Urea secures nitrogen within the soil
- Reduces volatilization and leaching up to 30% more than standard Urea
- With the added benefit of carbon for cell structure, it increases energy, water and nutrient holding capacity
- Longer shelf life (Holds up in humidity) | Yes |
Beard Octane FACE & BODY WASH Neutral
Face & Body Wash - Neutral
Beard Octane is proud to introduce our Face & Body Wash (FBW). FBW is the perfect "All-In-One" body wash solution for removing all of the dirt and grime from your ever-so-majestic physique. To keep it simple, FBW is a Liquid Body Soap that can be safely used on your face & beard. For a more thorough beard wash/cleanse, you would want to use our Lather Conditioning Wash (LCW).
Strong, yet gentle. The FBW is a sugar based Organic Aloe Vera rich liquid wash that was created for the hard working Man. FBW contains healing botanical ingredients which will nourish and protect your skin. The essential oils utilized will help boost antioxidants, while the plant based fatty acids will help restore cell permeability for stressed and tired skin. This is a must have for any Man that wants to keep their temple feeling fresh and clean! Pair it with LCW for the ULTIMATE shower experience!
SCENT STRENGTH: Light
SCENT NOTES: Light Scent From Natural Ingredients
FBW IS DESIGNED TO:
- Clean Your Face, Body & Beard w/o Stripping Natural Oils
- Moisturize Your Skin
- Soften Your Skin
- Make Your Skin Feel Majestic
Ingredients: Beard Octane uses only the highest quality ingredients in each of it's beard care products. Beard Octane's Face & Body Wash contains the following ingredients:
- Deoinized Water
- Dimethyl Sulfone
- Decly Glucoside
- Organic Aloe
- Cocamidopropyl Detaine
- Cocamidopropyl Hydroxysultaine
- Organic Rosehip Seed Oil
- Organic Olive Oil
- Vitamin E
- Tea Tree Essential Oil
- Eucalyptus Essential Oil
- Lavender Hydrosol
- Ocean Mineral Concentrate
- Organic Astragalus
- Organic Calendula
- Grapefruit Seed Extract
- Organic Reishi
- Organic Rosemary
- Organic Red Clover
- Organic Gotu Kola
- Organic Dandelion
- Orange Peel Extract
- Cocamide Mipa
- Disodium Laureth Sulfosuccinate
- Diodium Laurly Sulfosuccinate
- Hydroxyethyl Ethylcellulose
- Potassium Sorbate
- Sodium Bensoate
- Essential Fragrance Blends
- All of our products are made in MERICA.
- All of our products are tested on Humans, NOT Animals.
- All of our oil products contain Tree Nut Oils & Natural Botanicals.
- All of our products are Phthalate free.
- All of our bottles & jars are BPA free, with our jars being made of PET plastic.
- If you have Allergies, test on a friend, then yourself before use, or you can do the logical thing and consult with your physician.
- Intended for Adult use only, not suitable for individuals under the age of 18. | Yes |
Standard Practice for Evaluation of Antimicrobials as Preservatives for Aqueous-Based Products Used in the Paper Industry (Bacterial Spoilage)
|Publication Date:||1 April 2013|
|ICS Code (Paper production processes):||85.020|
This laboratory practice is used to determine the efficacy of an antimicrobial for preventing bacterial spoilage of inprocess aqueous-based products used in the paper industry. For information on fungal spoilage, see Test Method E875. This practice should be performed by persons who have had basic microbiological training.
The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. (See 40 CFR Part 160.)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. | Yes |
Chetpattananondh, P., Nitipavachon, Y. and Bunyakan, C. Biofiltration of air contaminated with methanol and toluene Songklanakarin J. Sci. Technol., Dec. 2005, 27(Suppl. 3) : 761-773 Biofiltration of air contaminated with VOCs is inexpensive compared with the conventional techniques and very effective for treating large volumes of moist air streams with low concentrations of VOCs. In this study, biofiltration for the purification of polluted air from methanol, a hydrophilic VOC, and toluene, a hydrophobic VOC, was investigated. The experiments were operated using three separated stainless steel biofilters, for methanol, toluene, and a mixture of methanol and toluene, respectively. Biofilter consisted of a mixture of palm shells and activated sludge as a filter-bed material. Only the indigenous microorganisms of the bed medium without any addition of extra inoculum were used throughout the whole process. The polluted air inlet concentration was varied from 0.3-4.7 g/m3 with flow rates ranging from 0.06-0.45 m3/h, equivalent to the empty bed residence times of 9-71 sec. Polluted air was successfully treated by biofiltration, 100% removal efficiencies would be obtained when the air flow rate was lower than 0.45 m3/h. The presence of toluene did not affect the removal rate of methanol while the removal rate of toluene was decreased with the presence of methanol in air stream according to the competition phenomenon. | Yes |
Beautiful pigment powders to make all your artistic projects glow in the dark.
Why is this FunShowCase Liquid Dye such a great glow in the dark product?
- This seller proposes a stunning range of 20 different color pigment powders : lemon yellow, yellow, light purple, sky blue, magenta, orange, sapphire blue, blue, violet, green, white, red, silver black, purple, jade white, rose red, peach red, orange red, apple green and pink.
- This product is packaged in small squeezable bottles. Each bottle contains 0.35 oz (10 grams), so you have 7.05 oz in total (200 grams).
- This product is a glow in the dark liquid dye. It is highly concentrated, which means a little goes a long way.
- This dye can be used as a base and mixed with other pigments to achieve the desired color.
- Shipping is free.
A little goes a long way
- non-toxic and non-radioactive
- sealed bottles with fine tip
- wide range of colors
- long lasting glow
- uniform coloring
- easy to mix with liquid medium
- shipping may take longer, this is a Japanese product
What people love about this FunShowCase liquid dye for glow in the dark epoxy and resin
- This liquid dye can be used for 2-part resin jewelry casting, acrylic paint, nail art, resin pour art, fine arts etc.
- The color is very uniform.
- The dye is easy to mix, unlike pigment powder that can form clumps.
- Excellent for resin projects : take 5 drops of resin and 1 drop of pigment. Mix well with a stick to avoid bubbles. Put in a mold of your choice and cure. If you use too much dye, the resin will not dry easily.
- You can create your own color by mixing different dyes.
Tips to use this FunShowCase liquid dye for glow in the dark epoxy and resin
- Shake the bottle well before every use.
- The tips of all the dye bottles have been sealed to avoid leakage during transport. Just cut off the tip with scissors or drill a hole in the seal with a push pin when you first use the product.
- Use gloves when using this fluorescent dye to avoid staining your fingers and hands.
- When your project is finished, you need to “charge” the glow in the dark pigments with a UV lamp or under direct sunlight. It will then magically begin to glow !
- You can achieve different degrees of luminosity by adding different amounts of dye.
- Here are a few ideas for creations using glow in the dark dye : resin charms, volcano diorama, ceramics, jellyfish sculptures, ear gauges, gummy bears (not the edible kind), soap, slime projects…
Make wonderful resin work with the unique colors of this liquid glow in the dark dye. | Yes |
- dry cleaning;
- cleaning products made of genuine leather and fur;
- stain removal;
- cleaning of work clothes;
- cleaning products that require an individual approach;
- minor repairs.
Also, the company specializes in the production of PROFESSIONAL CHEMISTRY.
We offer the following services:
- washing and ironing of things by professional means;
- dry cleaning of clothes and textiles;
- dry cleaning of carpets;
- cleaning of apartments and houses;
- sale of European household chemicals;
- rent of textiles. | Yes |
সিলেটের চাকরির খবর
Job title: Chemist
Job description: Job Context
- National Energy Services Limited (NESL) is a company incorporated in Bangladesh rendering comprehensive human resource solutions to energy, construction and manufacturing industries of Bangladesh. We recruit across various verticals for multinational corporations as well as leading business houses of the country.
- NESL now invites applications from competent candidates for the post of Chemist for employment with our prospective clients working in oil and gas industry.
- The position will be responsible for perform day to day technical laboratory analysis of a natural gas plant. The position requires working on non-routine tasks (sampling and analysis) requested by operations, maintenance, or any other department. The position is dynamic and requires a mix of laboratory and analytical skills depending on the operations requirement. Candidate must maintain a high degree of independence and responsibility, and accountability in planning and reporting laboratory experiments. Candidate must be able to communicate clearly and effectively with senior chemists/engineers in the Process Support and laboratory experiment to maximize productivity by applying technical skills and experience routinely and by drawing on knowledge and skills of other experienced personnel. This is a safety sensitive position.
- Responsibilities for this position may include but are not limited to:
- Analytical laboratory operations services are but not limited to:
- Sampling of Natural gas, condensate, water, ethylene glycol, TEG, Lube oil and process fluids.
- Monitoring integrity of sample during sampling of process and non-process fluids done by operations personnel.
- Calibration and maintenance of analytical equipment (like – GC, GC MS, ICP, IC, KF coulometer, Potentiometer, etc.).
- Perform Natural gas analysis: dew point test, gas composition, heating value & specific gravity (SG) as per ASTM methods.
- Perform Natural gas condensate analysis as per ASTM methods: Simulated distillation, API gravity, SG, BS&W.
- Perform pH, Conductivity, turbidity, alkalinity, Hardness, TDS, TSS, Chloride, TPH, anions, cations, Dissolve oxygen, BOD, COD, and other parameters of water as per ASTM, EPA, APHA or domestic methods.
- Perform test for Glycol (MEG & TEG).
- Perform Lube oil test.
- Data archiving and report preparation for internal & external stakeholders.
- Inventory management.
- Prepare All reagents and standardize as per methods.
- Sample bottle & glassware cleaning, labeling and preparedness.
- Proper housekeeping & cleanness at desk and workplace.
- Bachelor’s degree in Chemistry, Applied chemistry or chemistry-related major. Master’s in chemistry will be an advantage but not essential.
- 1 to 3 year(s)
- 1-2 years of Laboratory experience.
- Fluent in computer operating skill with MS office, internet browser and email communication.
- Knowledge on Laboratory safety (chemical handling safety, PPE, SDS, emergency response etc.) and industrial safety.
- Very good communication skill in both Bengali & English.
- Dominant work schedule will be 14 days on/ 14 days off basis. Work Schedule may vary as per Company`s requirement.Yearly two annual allowance/bonus. Cell phone allowance. Group life Insurance coverage. Hospitalization Insurance coverage.
Compensation & Other Benefits
- Over time allowance
Bdjobs.com Online Job Posting.
Job date: Mon, 25 Oct 2021 23:55:11 GMT
Apply for the job now! | Yes |
Phosphor Analyzer checks plasma display panels.
PDP Analyzer characterizes phosphors used in plasma display panels in terms of emission wavelength and lifetime. It delivers vacuum UV excitation wavelengths at 146 nm, 173 nm and more. Excitation wavelengths are focused to sample phosphors. Phosphor emission is collected and delivered to spectrometer for analysis of phosphor emission. In single channel mode, phosphor samples may be analyzed for...Read More »
VIS-NIR Spectrometer includes operating software.
Model USB2000-VIS-NIR off-the-shelf, plug-and-play, miniature, fiber optic spectrometer is usable in 350-1000 nm wavelength range. Arranged with pre-set grating, spectrometer plugs into USB port of any Windows 98 or Windows 2000-based PC. Unit's 2048-element linear CCD array detector, 25 -µm entrance slit, and 600 lines/mm grating combine to deliver optical resolution to 1.5 nm (FWHM). Unit is...Read More »
Spectrometer expands into spectrophotometric system.
USB2000 incorporates 3 accessories to enable its users to expand it into complete spectrophotometric system. Optimized for measurements from 390-900 nm, Direct-Attach Accessories combine application-specific sampling chamber with light source in small all-in-one package. USB-ISS-T model is designed for use with 12 mm OD test tubes. USB-ISS-VIS and USB-FHS hold 1 cm square cuvettes and 1 in. or 2...Read More »
Maximizing the Recovery of Platinum Group Metals (PGMs) from your Spent Catalysts
Making a decision about how to dispose of your spent precious metal catalysts? Download now to find out more about precious metal refining, the responsible and profitable solution.Read More »
Precision Machining Solutions with Over 25 Years of Experience
Quality, customer service, and unbeatable value are the hallmarks of Hogge Precision. Since 1989 we have built a reputation as the go-to precision machining source, servicing many demanding industries. For CNC machining and screw machining, there are few manufacturers that can match our capabilities and expertise. See our video to learn more.Read More » | Yes |
Enzyme models@MOF- Synthesis and analysis of MOFs and their catalytic products
Enzyme models are chemical compounds that can catalyze a large number of reactions by mimicking the active site of enzymes. Compared to enzymes, however, they have the advantage of being easier to produce and therefore less expensive, as well as being less sensitive to various reaction conditions.
To date, intensive fundamental research has been carried out in the field of enzyme models. In order to improve the technical applicability of those systems, they need to be immobilized. This will not only facilitate the separation of the reaction mixture, but also improve the reusability of the enzyme models or, make it even possible in the first place. Metal-organic frameworks (MOF) are to be used for immobilization. Similar to Enzyme@MOF, the enzyme models can be embedded in the MOFs. In addition, it is also conceivable to build up a MOF directly from the enzyme model. This would result in numerous advantages: On the one hand, a high catalyst density can be expected, since the support material and target molecule are identical. On the other hand, the regular and porous structure of the MOF should allow effective mass transport of the reactants to the active sites, which should lead to high turnover rates of the overall system. In addition to the synthesis and analysis of the MOF, the effects of immobilization of the enzyme models on the catalytic performance should also be investigated.
Projects can be assigned at any time based on interest. Just send me an email and we can discuss everything else in person. | Yes |
One day you look in the mirror and discover that one of your favorite outfits is starting to show perfume stains. This doesn't mean the garment is ruined or you'll never be able to wear it in public again. There are several ways to remove the stain completely. All it takes is a little bit of time, and some ingredients you might find around the house.
Things You'll Need
- Cotton ball
- Warm water
- Hydrogen peroxide
- White vinegar
- Liquid dish detergent
- Commercial stain remover
Use cotton to absorb excess moisture if the stain has just appeared. Sometimes the alcohol in a perfume causes a reverse-stain effect, and it’s essential to remove any chemicals from the clothes as quickly as possible.
Soak a cheesecloth with denatured alcohol and lightly rub the damaged area with the soaked cheesecloth. This helps redistribute remaining colors evenly after a reverse stain.
Submerge washable fabrics immediately in warm water if the stain is fresh. After soaking, wash the fabric and let it air dry. A dryer will actually set the stain if it's not completely removed.
Wet washable fabrics with glycerin if a stain has been there for a while. Thoroughly rinse the fabric then wash normally.
Treat perfume stains on white clothing by applying a solution made of equal parts of water and hydrogen peroxide.
Try dabbing household ammonia on the stain as an alternate treatment. Then wash the stained area with liquid detergent.
Make a stain-cleaning solution using 1 qt. lukewarm water, 1 Tbs. white vinegar and 1/2 tsp. liquid dish detergent. Soak the damaged garment in this solution then wash the garment in your usual manner.
Consider using a commercial stain remover if the perfume stain is very old. Follow the directions on the product label.
Take the clothes to a dry cleaners if the fabric isn't washable. But first, sponge the stain with a small amount of warm water. | Yes |
A third-party in Drug Testing and R&D, jointly
established by Sino Harbour Holdings Group Limited and Zhejiang University of
Technology, is dedicated to providing objective, impartial, independent and
efficient drug analysis and testing.
Irvine Pharmaceutical Services Co., Ltd owns a 30-year
history and has been approved by FDA and USP, and participated in the
calibration of standard products of the United States Pharmacopoeia. | Yes |
In vitro Assessment of Antibacterial and Antioxidant Activities of a Congolese Medicinal Plant Species Anthocleista schweinfurthii Gilg (Gentianaceae)
Koto-te-Nyiwa Ngbolua, Rosie Esther N. Mubindukila, Pius T. Mpiana, Masengo C. Ashande, Robijaona Baholy, Pierre Ruphin Fatiany, Takoy L., Grégoire E. Ekutsu, Zoawe B. Gbolo
Corresponding Author : Koto-te-Nyiwa Ngbolua,
Department of Biology, Faculty of Science, University of Kinshasa, P.O. Box 190 Kinshasa XI, D.R. Congo.
Email ID : email@example.com
Received : 2014-05-22 Accepted : 2014-06-15 Published : 2014-06-15
Abstract : The plant species Anthocleista schweinfurthii is eaten by bonobos, an endemic pygmy chimpanzee of Democratic Republic of the Congo and also used in folk medicine to treat bacterial diseases. To provide a scientific basis to traditional uses, the plant species was screened for it antibacterial and antioxidant potential.Antibacterial activity was assessed by minimum inhibitory concentration method. The presence of phytoconstituents was evaluated qualitatively. A. schweinfurthii extracts displayed interesting antibacterial and antioxidant activities. The Gram positive bacteria S. aureus ATCC 33591 were more sensitive to A. schweinfurthii than the Gram negative E. coli ATCC 27195. The stem bark extracts and n-hexane fraction of the leaves were found to be biologically active against Staphyloccocus aureus ATCC 33591 strains (MIC ≤ 62, 5 µg/mL) while, the bioactivity of dichloromethane, ethyl acetate and methanol soluble fractions of the leaves was moderate (MIC > 100 µg/mL). The methanol extract of the stem bark displayed interesting bioactivity (MIC = 62,5 µg/mL) while the leaves based extracts and the n-hexane, the dichloromethane and the ethyl acetate fractions of the stem bark of A. schweinfurthii displayed moderate activity against E. Coli ATCC 27195 strains (MIC > 100 µg/mL). Methanol extract of A. schweinfurthii displayed also interesting free radical Scavenging activity (IC50 < 10 µg/mL). Phytochemical analysis revealed the presence of total polyphenols, alkaloids, terpenes and steroids while, anthocyanins, leuco-anthocyanins, flavonoids, tannins, coumarins, quinones and saponins were absent in the plant extracts. Antibacterial and free radical scavenging efficacy shown by this plant provides a scientific basis and thus, validates it traditional use as phytomedicine. Isolation and purification of different phytochemicals may further yield significant antibacterial and antioxidant agents.
Keywords : Traditional medicine, Anthocleista schweinfurthii, bacterial infections, antioxidant activity, Democratic Republic of the Congo
Citation : Koto-te-Nyiwa Ngbolua, et al (2014), In vitro Assessment of Antibacterial and Antioxidant Activities of a Congolese Medicinal Plant Species Anthocleista schweinfurthii Gilg (Gentianaceae). J. of Modern Drug Discovery and Drug Delivery Research. V1I3. DOI : 10.5281/zenodo.1000302
Copyright : © 2014 Koto-te-Nyiwa Ngbolua. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Journal of Modern Drug Discovery and Drug Delivery Research
ISSN : 2348-3776
Volume 1 / Issue 3
ScienceQ Publishing GroupDownload Article
Reviewer Comments : | Yes |
Ford Named Fused Silica Product Manager for Morgan Advanced Materials
A son of the founder of George Ford & Sons, a producer of fused silica in the U.S., Ford reportedly built his career for over 40 years and has worked in all aspects of the business.
Tom Ford, former president of George Ford & Sons, has been appointed Fused Silica product manager at Morgan Advanced Materials’ Haldenwanger business. A son of the founder of George Ford & Sons, a producer of fused silica in the U.S., Ford reportedly built his career for over 40 years and has worked in all aspects of the business.
The demand for fused silica rollers is reportedly rising, with the fused silica market expected to grow 5.9% per year. According to Morgan, its fused silica rollers offer superior thermal shock resistance and material strength to ensure a consistently high-quality, scratch-free glass.
Ford will be attending Morgan’s exhibition in booth 538 at the GlassBuild America conference in Las Vegas, September 12-14. “I am looking forward to beginning this new chapter of my career with Morgan Advanced Materials,” he said. “It will be a great opportunity at the GlassBuild exhibition to chat with customers and anyone who wants to learn more about how fused silica rollers can shape their business. I cannot wait to get started. The market is constantly changing, and my new role will involve a lot of consultations.”
For more information, visit www.morgantechnicalceramics.com/haldenwanger. | Yes |
This image of a squirrel was printed in color by controlling the
thickness of a colorless ink deposited on a thin film.
Credit: American Chemical Society
(February 10, 2016) From dot-matrix to 3-D, printing technology has come a long way in 40 years. But all of these technologies have created hues by using dye inks, which can be taxing on the environment. Now a team reports in ACS Nano the development of a colorless, non-toxic ink for use in inkjet printers. Instead of relying on dyes, the team exploits the nanostructure of this ink to create color on a page with inkjet printing.
Current technologies blend dyes — think CMYK or RGB — to print in color. But these substances can harm the environment. Some dyes are toxic to marine life or can react with disinfectants like chlorine and form harmful byproducts. An alternative to dyes involves changing the nanostructure of materials so that they reflect light in particular ways. An example of this kind of coloring by light interference is found in nature: Squids can modify the nanostructure of their skin to mirror back their surrounding environment, creating a natural camouflage. Previous research has investigated printing color by light interference, but these attempts have required high-temperature fixing or specialized printing surfaces. Aleksandr V. Yakovlev, Alexandr V. Vinogradov and colleagues at ITMO University wanted to develop a nanostructure color printing technology that is “greener” and can be printed on a wide variety of surfaces. | Yes |
This paper concerns the cadmium sorptive effects by river bed sediments on longitudinal coefficient in an open-channel flow via experimental and numerical study. For this purpose, a circular flume was used with mean diameter of 1.6 m and a width of 0.2 m. The adsorbing bed was considered as a thin layer of the sediment particles with mean diameter of 0.5 mm and three sediment concentrations of 3, 12, and 20 gr/lit. To determine the sorption parameters of the sediments, some experiments were conducted with three cadmium concentrations of 150, 460, and 770 ppb. Then, the dispersion experiments were carried out with and without the bed sediments. To solve the advection-dispersion equation with considering the sorption term by river bed sediments, a numerical model was then developed. The longitudinal dispersion coefficients were estimated by comparing the experimental and numerical breakthrough curves. The results showed that, with increasing the sediment concentrations, the sediment sorption rate increased and the longitudinal dispersion coefficient decreased by about 38, 36 and 33 percent, respectively, for cadmium concentrations of 150, 460 and 770 ppb. In addition, by increasing the cadmium concentrations, the changes in the longitudinal dispersion coefficient are decreased. Furthermore, a relationship was developed using non-dimensional longitudinal dispersion as a function of the new parameter of sorption ratio. From a practical point of view, the results of this study demonstrated that, at the presence of sediment, the cadmium is longitudinally dispersed with more delay in comparison with no sediment at the river bed. | Yes |
I’m often asked about ingredients that penetrate into the hair. Between me and you, it’s not a lot. HOWEVER in this video I’m sharing 5 ingredients that have been PROVEN to penetrate the hair effortlessly to deliver RESULTS we need!
Check out “Best 5 Ingredients That Easily Penetrate Into the Hair” video below!
Leave a Reply | Yes |
Cryosea™ Mermaid Fire and Ice Peel-Off Mask
- Low Stock
What it is: Feel the icy-cool effects of the high performance boscia Cryosea™ blend combining cryotherapy inspired ingredients like Sea Water, Red Algae, Sodium Hyaluronate, Sea Kelp, and Menthol to provide a cold-as-ice experience that lifts, tightens, plumps and increases circulation, leaving skin tingly, cool and perfectly prepped for application of next skincare steps. Mermaid-like holographic effect is courtesy of floating traveling pigments.
Pro Tip: Big night out? Apply the mask before makeup application for a brighter, tighter, more radiant completion.
What it does:Cryotherapy inspired ingredients create a long lasting cooling effect that lifts, plumps and invigorates skin while prepping it for delivery of potent ingredients.
A rare and precious marine-based complex providing the ultimate in cooling and hydration.
Instantly hydrates, cools and soothes the skin, leaving it feeling moisturized and refreshed.
Care is taken throughout the growing process to ensure the best quality by means of a procedure that is sustainable and renewable.
Soothes, plumps and revitalizes skin
Promotes blood circulation to depuff, brighten and refresh skin
Penetrates outermost layer of skin, leading to more efficient penetration of ingredients
Sea Kelp Extract
Rich in antioxidants and minerals
Brightens, tightens and evens skin tone
Mineral rich ingredient purifies skin and improves circulation
Strengthens the natural skin barrier to achieve stronger and healthier skin
Delivers long lasting hydration while also plumping and smoothing skin
How to Use
Apply an opaque, even layer to clean, dry skin. Avoid eye area by applying below orbital bone. Do not apply to eyebrows, hairline or lips. Leave on for 20 minutes or until completely dry. Gently peel off mask from outer edges. Rinse off any residue with warm water.
Artificial fragrance & color-free
Water/Aqua/Eau, Polyvinyl Alcohol, Glycerin, Glycereth-26, Magnesium Aluminum Silicate, Chondrus Crispus Extract, Laminaria Digitata (Sea Kelp) Extract, Sea Water Extract, Hyaluronic Acid, Menthol, Copper Chlorophyll, Acetyl Cysteine, Acetyl Hexapeptide-8, Simmondsia Chinensis (Jojoba) Leaf Extract, Epilobium Angustifolium Flower/Leaf/Stem Extract, Sea Salt, Silica, Caprylyl Glycol, Ethylhexylglycerin, Disodium EDTA, Mica, Iron Oxides (77499, 77491), Titanium Dioxide (CI 77891), Tin Oxide, Ferric Ferrocyanide (CI 77510), Synthetic Flueorphlogopite, Chromium Oxide Greens (77288)
Please refer to the ingredient list shown on your product for the most up-to-date information.
80g /2.8oz U.S.
About the Brand | Yes |
Home > Science > OCR 21st Century Science > Chemicals in our lives - risks and benefits > Manufacture and use of chemicals
Chemicals in our lives - risks and benefits
When an alkali neautralises an acid, what is made?
salt and water
stay in one place
What was the LeBlanc process?
a process helping to reduce pollution
a process of making alkalis on a large scale
a process of making acids on a large scale
How was the polluting gas, hydrogen chloride, usefully disposed of?
filtering the gas
by adding more acid
being oxidised to chlorine
What is added to water to make is safer to drink?
Why is chlorination of water a risk?
it produces THMs which may cause cancer
it may make the water taste bad
it may make the water look different
What is brine made up of?
sodium and chlorine
water and sodium chloride
What useful chemicals are obtained during the electrolysis of brine?
hydrochloric acid and sodium hydroxide
chlorine, sodium hydroxide and hydrogen
sodium hydroxide, chlorine and hydrochloric acid
Suggest a use of sodium hydroxide:
processing food products | Yes |
Safe Tetracycline 250mg India Is Tetracycline Available InTetracycline capsules, Heritage 250 mg, 100 count (NDC 23155-0017-01).
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Dose for puppies how much is 300 mg of hydrochloride tetracycline gas x what do s inhibit photocatalytic degradation of.This discovery by Woodward was a major advancement in tetracycline research and paved the way for the discovery.Drug information. then 500 mg every six hours for four days. Tetracycline (Class) (Oral Route, Parenteral Route) Mayo Clinic Footer. Request.
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20 Jun 2002
Researchers in the Netherlands have found that polystyrene is almost invisible to terahertz waves.
Polystyrene foam has dielectric properties that make it an ideal material for use in imaging devices based on terahertz radiation, according to Dutch scientists.
A series of measurements performed by researchers from Delft University of Technology show that polystyrene offers a very low refractive index (around 1.016 to 1.022) and little dispersion in the 0.1 to 4 THz region. As a result, pulses of terahertz radiation pass through the material will almost no loss or distortion.
Research groups all around the world are currently developing terahertz imagers that operate in this spectral region to penetrate fog, detect explosives and probe the inner workings of biological samples.
However, work is being hampered by the lack of suitable materials that offer a low refractive index and are highly transparent in the terahertz frequency range.
The Delft team says that polysterene is well suited as both a substrate material for terahertz imagers and a filter material for blocking near-infrared light while passing terahertz pulses.
The team performed transmission experiments with three types of polystyrene made with various blowing agents. Samples just 2 cm thick were placed in the path of the terahertz waves and their extinction coefficient and refractive index were plotted against frequency. Polystyrene blown with carbon-dioxide performed best in the experiments.
Oliver Graydon is editor of Opto and Laser Europe magazine. | Yes |
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A phospholipid which has the ability to replenish the skin’s natural barrier function. Has anti-inflammatory and antibacterial properties.
High levels of skin cell energy are key to maintaining a youthful and glowing complexion. These levels follow the circadian rhythm, a 24-hour cycle. The energy levels in the cells drop during the day and the result is a loss of glow in the afternoon which will be only recovered during the night. Dull looking skin is mainly caused by low cell energy. Skin that is energized throughout the cell’s circadian rhythm has a consistent glow and displays a fresh complexion. REVITALIN® PF, with its energy-providing actives produced by fermentation of baker’s yeast, ensures high energy levels and an all day long youthful, glowing complexion.
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What is oleosome?
Definition of oleosome : a fat or fatty inclusion in cytoplasm.
Where are Oleosomes located?
Oleosomes are present in many plant tissues, like roots and leaves , however, they are most abundant in seeds and nuts . They are biosynthesized in seed embryo cells by lipid biosynthetic enzymes and accumulate in dry seed cells [6,11].
What are safflower Oleosomes?
Oleosomes is the name for oil bodies and Carthamus tinctorius commonly known as safflower. Oleosomes are very small spheres usually of micron in size. Carthamus tinctorius oil is obtained by pressing its seeds. Skin is the largest organ of our body.
Where are oils stored in plant cells?
Oil bodies are lipid (mainly triacylglycerols) storage compartments that occur primarily in seeds and senescing leaves. Seed oil bodies develop from the endoplasmic reticulum in embryo cells during seed maturation and are degraded during seed germination and subsequent seedling growth.
What do oil droplets store in plant cells?
The seeds of plants store significant amounts of neutral lipids, namely triacylglycerols (TAGs), in cytosolic lipid droplets (LDs), most of which are subsequently mobilized immediately after germination in order to fuel the growth and development of the seedling prior to photosynthetic establishment.
In what part of a plant are oil body’s most concentrated?
Some species of vascular plants also contain intracellular structures called oil bodies. Vascular plant oil bodies consist mainly of triacylglycerols surrounded by a layer consisting of phospholipids and the protein oleosin. These oil bodies occur largely in seeds but also occur in other plant parts, including leaves.
What is the function of Sphaerosomes?
Sphaerosomes (also spherosomes) or oleosomes are small cell organelles bounded by a single membrane which take part in storage and synthesis of lipids.
Who discovered Spherosomes?
Sphaerosomes (also spherosomes) or oleosomes are small cell organelles bounded by a single membrane which take part in storage and synthesis of lipids. These were first observed by Hanstein (1880) but discovered by Perner (1953).
What are Elaioplasts?
Elaioplasts (Figure 2(c)) are plastids that specialize in oil synthesis and storage and are found primarily in the layer of cells in the anther that surrounds developing pollen grains (celled the tapetum or tapetal layer) (Suzuki et al., 2013).
Why is oil important for cells?
Oil Bodies are the organelle that has evolved to hold triglycerides in plant cells. The lipid and protein fractions of oil bodies are remarkable because they maintain a coherent monolayer over a wide temperature and hydration range.
What is the function of oil in seeds?
Oil bodies are found in many plant seeds and represent an efficient storage form of energy for a germinating embryo. Other, non-oilseed, plants rely primarily on starch as a storage form of energy in their seeds.
What is the function of oil droplets?
Recent studies indicate that oil droplets have two main functions: they act as intracellular microlenses that enhance light delivery to the outer segment (Stavenga and Wilts, 2014; Wilby et al., 2015; Wilby and Roberts, 2017); and they filter the spectrum of light reaching the outer segment, thereby improving color … | Yes |