Cell phones emit low levels of radio frequency energy (i.e., radio frequency radiation) in the microwave range while being used. It is well known that high levels of RF can produce biological damage through heating effects (this is how your microwave oven is able to cook food). However, it is not known to what extent or through what mechanism, lower levels of RF might cause adverse health effects as well. Several research studies have shown that the radio frequency radiation from wireless phone antennae “appears to cause genetic damage in human blood,” while another case study uncovered a “statistically significant increase” in neuro-epithelial brain tumors among cell phone users. Other research has shown little or no adverse effects. ABC’s 20/20 News (May 26, 2000) took the five most popular phones sold in the US and tested them at a highly respected German laboratory. Four out of the five phones tested were above the SAR limit. One thing is for certain, similar to the case of cigarette smoking, it will take several tests and many years before the effects of radio frequency radiation on the human body are known.
That’s why randomized controlled trials (RCTs) often yield fairly clear answers about the effectiveness of treatments compared to other study designs. (Fun fact: Scottish doctor James Lind, a clinical trial pioneer, figured out that citrus fruits seemed to have an effect on scurvy using one of the earliest RCTs.) RCTs can also be used to study whether something, like cellphone radiation, can cause disease.
Your phone sends radiofrequency, or RF, waves from its antenna to nearby cell towers, and receives RF waves to its antenna from cell towers when you make a call or text or use data. The frequency of a cell phone’s RF waves falls between those emitted by FM radios and those from microwave ovens, all of which are considered “non-ionizing” forms of radiation. That means that—unlike radiation from a nuclear explosion, a CT scan, or a standard X-ray—the radiation from your phone does not carry enough energy to directly break or alter your DNA, which is one way that cancer can occur. (FM radios and microwaves don’t raise alarms, in part because they aren’t held close to your head when in use and because microwave ovens have shielding that offers protection.)
But scientists disagree on how real—or how serious—these risks really are, and studies have not established any definitive links between health problems and radiofrequency (RF) energy, the type of radiation emitted by cell phones. “This document is intended to provide guidance for people who want to reduce their own and their families’ exposure to RF energy from cell phones,” the guidelines state, “despite this uncertainty.”
The RF waves from cell phones come from the antenna, which is part of the body of a hand-held phone. The waves are strongest at the antenna and lose energy quickly as they travel away from the phone. The phone is typically held against the side of the head when in use. The closer the antenna is to the head, the greater a person’s expected exposure to RF energy. The body tissues closest to the phone absorb more energy than tissues farther away.
I received mine yesterday in the mail. I have a Samsung Galaxy Note 3, and I cannot use this sock unless I take the case off. This is one thing I did not know when I was purchasing this material. I am trying it out as stated, however even when I use a rubber case or a very thin case with the sock its very tight to get off. I think the manufacturer needs to allow more room in these and or not state that it fits the larger phones at 6 inch. They should state that without the case it will fit. I am in the first day of walking around without a case, and just the sleeve. Its different, and if I drop my phone I'm in a world of hurt. I like the idea of this, but I was also surprised when the material really only feels like felt. It's not like the RF fabric that I have seen, and hopefully this is some kind of special blocking material as stated. I do like the idea, and I agree that cell phone radiation exist. Ill come back and give five stars if I really notice a difference, however if I drop my phone because I dont have a case I'm going to be posting less stars.
Forced to take action, the cell phone industry set up a non-profit organization, Wireless Technology Research (WTR), to perform the study. Dr. Carlo developed the program outline and was asked to head the research. Oversight of the issue was charged to the FDA, though it could have and probably should have gone to the Environmental Protection Agency (EPA), which fought hard for jurisdiction. But the industry had enough influence in Washington to get whatever overseer it wanted. It simply didn’t want to tangle with EPA because, says Dr. Carlo, “… the EPA is tough.”
“One thing all these conditions have in common is a disruption, to varying degrees, of intercellular communication. When we were growing up, TV antennas were on top of our houses and such waves were up in the sky. Cell phones and Wi-Fi have brought those things down to the street, integrated them into the environment, and that’s absolutely new. The recognition mechanism, where protein vibration sensors on the cell membrane pick up a signal and interpret it as an invader, only works because the body recognizes something it’s never seen before.”
Today, the computer and phone have merged into one device that fits in the palm of your hand. A smartphone is essentially a small computer, yet has many times the computing power of traditional computers. There are no cords to connect you to a base. When turned on in your pocket or being used against your head, the cell phone touches some of the most sensitive parts of the body. Although the cell phone produces lower levels of radiation then past computers, they are now used much closer to the body and for longer periods of time, thus creating more health risks than in the past.
Stereo Hands-Free Headset with a gold plated 3.5mm, 3 band plug. Sporty lightweight design, this headset provides clear stereo sound quality comfortably to your ears. The convenient microphone allows you to make and receive calls at the touch of a button. Compatible with all universal 3.5mm headphone jacks. Can be used with Ferrite Snap Bead to further reduce RF exposure.
Simply snap your phone into the dent resistant bumper cradle. Flip the Cruz Case lid open to receive or make calls, then close back into protective mode. To use properly, flip open the Cruz flip lid cover to answer a call, flip back the cover over the face of the phone and talk through the flip lid cover with perfect clarity. Always keep the flip lid cover between you and your phone even when carrying in your pockets. The attractive and stylish Cruz Case technology provides up to 60dB at cell phone frequencies. Patent pending design does not affect the signal to the cell tower. Ultra-slim design also provides scratch protection for the display and helps keep the screen clean. Keeps your phone looking new. Includes credit card holder feature as well. Select model to fit.
The World Health Organization states that "A large number of studies have been performed over the last two decades to assess whether mobile phones pose a potential health risk. To date, no adverse health effects have been established as being caused by mobile phone use." In a 2018 statement, the FDA said that "the current safety limits are set to include a 50-fold safety margin from observed effects of radiofrequency energy exposure".
Just why Schwann and glial cells appear to be targets of cell phone radiation is not clear. David Carpenter, a physician who directs the Institute for Health and the Environment at the University at Albany, S.U.N.Y., explained the purpose of these cells is to insulate nerve fibers throughout the body. These are electrical systems, so that may be some sort of factor, he wrote in an e-mail. “But this is only speculation.”
The frequency of radiofrequency electromagnetic radiation ranges from 30 kilohertz (30 kHz, or 30,000 Hz) to 300 gigahertz (300 GHz, or 300 billion Hz). Electromagnetic fields in the radiofrequency range are used for telecommunications applications, including cell phones, televisions, and radio transmissions. The human body absorbs energy from devices that emit radiofrequency electromagnetic radiation. The dose of the absorbed energy is estimated using a measure called the specific absorption rate (SAR), which is expressed in watts per kilogram of body weight.


Single - Phase Uninterruptible Power Supply System 1.0 GENERAL 1.1 SUMMARY
This specification defines the electrical and mechanical characteristics and requirements for a continuous-duty single-phase, solid-state, uninterruptible power system. The uninterruptible power system, hereafter referred to as the UPS, will provide high-quality AC power for sensitive electronic equipment loads.
The UPS is designed in accordance with the applicable sections of the current revision of the following documents. Where a conflict arises between these documents and statements made herein, the statements in this specification shall govern.
UL Standard 1778, UL 1499
FCC Part 15, Class A
1.3. SYSTEM DESCRIPTION 1.3.1 Modes of Operation
The UPS is designed to operate as a line interactive uninterruptible power supply in the following modes:
A. Normal - In normal operation incoming AC power is fed to the input, conditioned and applied to the connected equipment. In this mode, power is also derived from utility power for the battery charger. In the event of a utility outage or severe abnormality (sag or swell), the UPS will support the connected load from battery power, until the battery is discharged or the utility returns; whichever occurs first.
B. Battery - Upon failure of utility / mains AC power, the critical AC load is supplied by the battery. The switch over time to battery is less then 2 milliseconds.
C. Recharge - Upon restoration of utility / mains AC power, after a utility / mains AC power outage, the input converter automatically restarts and resumes supplying power to the connected load and the battery charger to recharge the battery.
D. Automatic Restart - Upon restoration of utility / mains AC power the UPS automatically restarts and assumes supplying power to the critical load and the battery charger.
1.3.2 Design Requirements A. Voltage: Input/output voltage specifications of the UPS are:
B. Output Load Capacity: Specified output load capacity of the UPS is:
2200 VA/1980 Watts at 0.9 lagging power factor.
C. Internal Battery: Valve regulated, non-spillable, flame retardant, lead acid cells.
D. Reserve Time: 2200 VA minimum 9.7 minutes, these times are at full load with ambient temperature of 25oC (77oF).
E. Battery Recharge: The UPS contains a battery recharge rate designed to prolong battery life. Recharge time for UPS internal batteries is three (3) hours maximum to 90% capacity after a complete discharge into full load.
1.3.3 Performance Requirements 184.108.40.206 AC Input to UPS A. Voltage Configuration: The UPS operates at 120 VAC nominal; single phase without drawing power from the batteries. The input voltage can be adjusted to operate within the range of 74-154 VAC.
120 VAC; single phase, 2 wire plus ground nominal; variable based upon output loading:
B. Frequency: UPS auto senses input frequency when first powered up and will operate within the following frequency specifications. The UPS is capable of auto sensing input frequency of 50/60 Hz @ 120 VAC +/- 3%.
C. Surge Protection & Filtering
Surge energy rating is 880 Joules, 6.5kA.
Full time multi pole noise filtering; 0.3% IEEE surge let through; zero clamping response time.
Input EMI filters are employed in accordance with MIL-461
220.127.116.11 AC Output, A. Voltage Configuration: 120 V Units: 120 VAC, 60/50 Hz, single-phase, 2-wire-plus-ground configuration
B. Voltage Regulation: + 3% steady state.
C. Frequency Regulation: 47-53 Hz nominal for 50 Hz, 57-63 Hz nominal for 60 Hz, Synchronized to utility / mains.
D. Output Line Distortion: less than 5%
E. Output Power Rating: 2200 VA/1980 Watts at 0.9 lagging power factor.
F. Crest Factor: up to 5:1
G. Filtering: Output EMI filters are employed in accordance with MIL-461
H. Waveform: Sine wave
18.104.22.168 Output connectors
(2) Mil-5015 MS circular connectors
1.4 Environmental Conditions A. Ambient Temperature:
Operating: 0O C to +40O C (+ 32O F to + 104O F) for altitudes 0 to 3000 meters (0 to 10,000 ft.) above sea level.
25O C (+ 77O F) for optimum battery performance
Storage: -15O C to +50O C (+ 5O F to +113O F) with batteries removed.
Storage elevation 15000 M max.
20O C (+ 68O F) for optimum battery storage.
B. Relative Humidity:
Operating: 0 to 95% non-condensing.
Storage: 0 to 95% non-condensing.
C. Audible Noise: Noise generated by the UPS under normal operation does not exceed 50dBA when measured at 1 meter from the surface of the UPS.
E. Electrostatic Discharge: The UPS is able to withstand an electrostatic discharge compliant to ENC61000-4-2, level 4, for 120 VAC, 208 VAC, and 230 VAC units (15 kV through air, 8 kV contact) without damage and will not affect the connected load.
1.5 USER DOCUMENTATION The specified UPS system is supplied with one (1) user's manual.
1.6 WARRANTY The UPS manufacturer warrants the UPS against defects in materials and workmanship for one (1) Year
1.7 QUALITY ASSURANCE
1.7.1 Factory Testing Before shipment, the manufacturer fully and completely tests the system to assure compliance with the specification. These tests include operational discharge and recharge tests on the internal battery to assure performance.
2.0 PRODUCT 2.1 FABRICATION The UPS is manufactured and fabricated in accordance with MIL-STD -901D and MIL-STD-167 as tested and certified. All materials and components making up the UPS are new, of current manufacture, and have not been in prior service except as required during factory testing. All relays are provided with dust covers.
2.1.2 Wiring Wiring practices, materials, and coding are in accordance with the requirements the standards listed in section 1.2 and other applicable codes and standards. All wiring is copper.
2.1.3 Cabinet The UPS unit is comprised of: input converter, battery charger, inverter, and battery consisting of the appropriate number of sealed battery cells; and is housed in a tower NEMA type 1 enclosure and meet the requirements of IP20. The UPS cabinet is cleaned.
Chassis is fabricated from 304 stainless steel.
MODEL DIMENSIONS (H x W x D) WEIGHT PS2201-SS-Grade A
17.0” x 8.0” x 22.0”
(43mm x 20mm x 55mm)
115.0 lbs. (52.1kg)
2.1.4 Cooling The UPS is forced air cooled by internally mounted fans. Fan power is provided from the internal power supply. Air intake is through the front of the unit and exhausted out the rear of the unit.
2.2 COMPONENTS 22.214.171.124 AC Input Current Limit The input converter is provided with AC input current limiting whereby the maximum input current is limited to 125% of the full load input current rating
126.96.36.199 Input Protection The UPS is supplied with a MIL-STD Hi-G force double pole circuit breaker in accordance with MIL-STD-901D and MIL-STD-167. The circuit breaker is rated at 20.0A The UPS has built-in protection against under voltage, over current, and over voltage conditions including low-energy lightning surges, introduced on the primary AC source. The 120 VAC models can sustain input surges without damage per criteria listed in IEEE 587 CAT. A & B.
188.8.131.52 Battery Recharge The UPS contains a battery recharge rate designed to prolong battery life. The battery is constant current charged to restore capacity, then shall be constant voltage charged to maintain the battery in a fully charged state. Recharge time for the internal UPS batteries shall be three (3) hours maximum to 90% capacity (full load discharge rate). There is DC over voltage protection so that if the DC voltage exceeds the pre-set limit, the UPS will shutdown automatically and the critical load is transferred to bypass mode.
184.108.40.206 Output Protection The UPS employs electronic current limiting circuitry.
220.127.116.11 Battery Over Discharge Protection To prevent battery damage from over discharging, the UPS control logic automatically raises the shutdown voltage set point; dependent upon output load at the onset of battery operation.
2.2.3 Display and Controls 18.104.22.168 General The UPS is provided with a microprocessor based unit status display and controls section designed for convenient and reliable user operation. The monitoring includes functions such as status and alarm, battery level and runtimes.
22.214.171.124 System Indicators
2.2.4 On-Line Battery Test The UPS is provided with an automatic biweekly battery test feature (factory default). Via the set-up configuration program on a Windows based PC the automatic battery test can be disabled or configured to operate every 7, 14, 21, or 28 days.
The battery test will ensure the capability of the battery to supply power to the inverter while loaded. If the battery fails the test, the UPS will display a warning message to indicate the internal batteries need replaced. The battery test feature is user accessible by the push button located on the front of the unit and with Communications Software. The Automatic Battery test feature is capable of being disabled through the User Configuration Program.
2.2.9 Configuration Program An included Windows tm based (Win95 or later) Configuration Program and cable allows for configuration of UPS features and operating parameters to meet specific application requirements, if required. Options that are configurable via this program include:
126.96.36.199 Automatic Transfers
The transfer control logic automatically activates the bypass, transferring the critical AC load to the bypass source, after the transfer logic senses one of the following conditions: UPS overload
UPS over temperature
DC Bus Over voltage
Once overload condition is reduced, the load is automatically transferred back to inverter power.
2.2.6 Internal Battery Valve regulated, non-spillable, flame-retardant lead acid cells are used as a stored-energy source for the specified UPS system. The battery is housed internal to the UPS cabinet, and sized to support the inverter at rated load and power factor, with ambient temperature of 25 O C (77 O F) for a minimum of 7 minutes reserve time. The expected life of the battery shall be 3 - 5 years or a minimum 250 complete discharge cycles. The UPS units have the capability to allow the operator to replace the internal battery.
2.2.7. Output Distribution Output distribution is integrated to the UPS, and located on the rear of the unit.
2.2.8 Communication The UPS includes one slot for optional communication options.
188.8.131.52 DB-9 Serial Port The UPS contains a DB9F (9-pin female) connector on the rear panel to allow UPS status communications to a computer system. The DB9F contains photo couplers to signal on battery and low battery operational status. The UPS is also capable of receiving a signal
2.2.8 Communication Options SNMP This option delivers SNMP and Web management to the UPS when connected to any 10 or 100 Mbit Ethernet network. The card supports 10 and 100 Mbit Ethernet and provides for in-the-field upgrade of SNMP firmware. The kit includes the card, software and installation manual. Once the card is installed, the serial communications is disabled in the DB9F connector.
Relay Interface Card This RELAYCARD-INT option provides dry contact closures for remote monitoring of alarm conditions in the UPS, delivering signals for On Battery, Low Battery, Summary Alarm, UPS Fault and On UPS.


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Two months after cellular industry association SIMalliance called for a new and more secure 5G SIM card standard, digital security company Gemalto announced today that it has developed the world’s first 5G SIM — a more secure solution that will roll out in the first half of this year.
Recognizing both increasing and evolving types of cellular devices, the 5G SIM will be offered in three form factors: a traditional removable SIM card, an embedded SIM (eSIM), and a machine-to-machine (M2M) SIM designed for internet of things devices. All of the versions will support both the 3GPP’s specifications and SIMalliance’s recommendations for 5G SIMs, enabling Gemalto to be the first to offer a solution deemed capable of securing 5G network access.
“The 5G SIM provides the foundation of trust in this next generation mobile network for operators and other stakeholders in the eco-system,” said Gemalto EVP Emmanuel Unguran. “It will help operators unleash the full 5G potential, maximize their network investments, and simplify new service deployment with full backward compatibility to previous 3G/4G technology.”
Compared with earlier SIMs, the 5G SIM will support seamless global 5G roaming, encrypt and fully anonymize subscriber identities, and increase security against hacks and data breaches. Due to the anonymizing feature, the new SIM is expected to reduce if not eliminate unauthorized location tracking, as well as ensure carrier compliance with personal data privacy laws.
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Though the earliest 5G devices are already shipping — a reality SIMalliance acknowledged last year by differentiating between “transitional” and “recommended” 5G SIMs — the new cards will be found in upcoming devices based on Qualcomm’s Snapdragon 855 platform.
“Qualcomm Technologies has a longstanding relationship with Gemalto focused on delivering mobile solutions with robust security,” said Qualcomm senior director Gautam Sheoran. “We are now extending this collaboration to allow OEMs to easily develop exciting 5G devices with strong security, using both Gemalto 5G SIM and our next generation flagship Qualcomm Snapdragon 855 Mobile Platform to pave the path for 5G commercialization in 2019.”
Gemalto expects that 5G SIMs will be used to manage over 1.5 billion 5G subscriptions by 2024, across mobile broadband, large-scale IoT installations, and other applications. SIMalliance has advocated for a single 5G SIM standard to guarantee an optimally secure and service experience to customers.
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Wi-Fi connect but data not downloading. some one will say setting problem, I am sure there is no setting problem. If u disconnect the Wi-Fi then it will not connect again.
Go for Samsung or HTC any other brand
Wi-FI is not working, battery problem, touch is not good.
Mmx guys provided a great phone for reasonable price, operating this phone gives you an awesome feeling.The battery backup is avg i.e it last for a day . The camera quality is good, the display is sharp and bright , great looks and feels.
* performance is great with octa core processor and ARM mali 450 MP4 GPU, all high end games are running smoothly without any frame lose or lag.
* good camera quality.
* screen size is just perfect.
* screen resolution .
* glossy looks.
sim card and micro sd tray
Best phone under 12000
Best screen resolution, fine looking, superb speed, excellent camera, good features like photo editing, fm recording.
Very disappointed. Either use second sim or memory card.
Why they say dual sim, they should clearly mention after product name "dual sim without memory card" or "single sim with memory card".
Very nice phone look wise. Only issue is with SIM card tray. Very uneasiness to open SIM trasy and place SIM card and Memory card inside it.


laptop repair job in delhi. We offer repair services at the doorstep by professionals free visiting, no diagnosis charge, on-call support.
Notebook fix is among the lots of jobs obtainable out there. As laptops are actually being used by just about every personal on this planet, there is a superb demand for laptop computer fix pros. There are several companies that make use of them plus they need individuals who can manage the issues. Because there are various companies featuring this services, you will see that it’s challenging for getting a gap. It’s important to work hard If you prefer to be successful In this particular area.You can find certain skills which all laptop computer fix professionals should possess so as to execute their duties efficiently. By searching through lots of on-line resumes, was ready to slim down the key commonest skills essential for this kind of placement. People who are trying to diagnose laptops should find out about unique forms of utilities.One of such could be the UPS battery. This can be the one particular answerable for the charging of the laptop computer. When there is a difficulty Along with the UPS battery or It’s not necessarily Functioning effectively, laptop computer repairs could be essential. Individuals who have the knowledge to change the battery need to be hired. Aside from the UPS battery, individuals also must know about the troubleshooting strategies that happen to be relevant Along with the keyboards.Other matters relevant Along with the laptop computer fix can include things like troubleshooting troubles relevant Along with the AC adapter. It needs to be ensured the voltage at the back of the laptop computer is correct. If the laptop computer overheats, the lover won’t get the job done effectively. To solve this challenge, individuals must diagnose the assorted concerns that think of the overheating difficulty.One more factor related to laptop computer fix is related to the keyboard. It is very important for laptop computer end users to make certain that the keyboard functions effectively. There are several aspects which cause a keyboard to prevent Functioning. Normally, individuals have to seek advice from on-line resources to learn the way to troubleshoot certain concerns just like the laptop computer overheating, laptop computer lover failure and so on.People that make use of the antivirus computer software to safeguard their computer devices must update it consistently. This computer software can help in detecting virus signatures in the program. When there is an current signature, it makes sure that the antivirus computer software detects every one of the threats. If your virus scanner detects a virus signature in the program, then it blocks the menace and allows the functioning program to run smoothly. People that use antivirus computer software need to know how to total laptop computer fix responsibilities which include things like antivirus computer software update.Individuals who want to do the laptop computer analysis on their own need to Understand that they must not make an effort to diagnose troubles which have to have additional advanced skills and solutions. Whenever they diagnose the program without having making sure the system is jogging Ordinarily, they may end up harming the system even more. For advanced analysis, they must connect the laptop computer towards the Home windows program, open up the diagnostics options by clicking on the Start button on the task bar and then click “My Pc”. They must then enter the product and serial numbers of the system. They can then press Okay and then wait for the system to begin Functioning once more.People who are unfamiliar with laptop computer computers, but know the battery plus the cooling program Within the laptop computer must seek advice from the person’s manuals for proper troubleshooting. If they cannot find any data in the manuals, they must get in touch with the producer for getting substitute batteries or Examine In the event the cooling program is triggering the situation. The next move is to remove the battery with the program and connect the battery towards the fixity. If every thing is alright Along with the connection, the individual need to You should definitely clear away the battery and ensure to setup the battery again once more.


Magneto-sensitive smart materials, also named as magnetorheological (MR) materials, are a class of smart composites prepared by dispersing nanometer- or micrometer-sized ferromagnetic fillers into the different carrier matrix. As the rheological properties can be controlled by an external magnetic field rapidly, reversibly, and continuously, magneto-sensitive smart materials have great application potential in construction, automotive industry, artificial intelligence, etc. In this chapter, a brief history and classification of magneto-sensitive smart materials are firstly summarized. Next, we discuss the state-of-the-art of the magnetorheological mechanism through experimental and theoretical studies, respectively. Finally, the prospect for this material in the future is presented.
- smart soft material
- magnetorheological material
- magnetic dipole theory
Most smart materials imitate natural biological materials, which can respond to the stimuli (like mechanical, thermal, electrical, photic, acoustic, magnetic, chemical, etc.) by changing one or multiple properties to adapt to the changing environment . So far, bioinspired smart materials have become an important research direction in material science. It is difficult for a homogenous material to possess multifunction, so it generally combines the materials with the functions of perception, actuation, control, etc., together in a specific way to design a novel composite with multiple characteristics. The smart material is multilevel with different components; each component has different characteristics and microstructures, and the coupling effect exists between different components, and these components make the smart material show complicated responses to external stimuli. Generally, the adapting ability of smart material to external environment, which is similar to the activated function of biological material, can be dynamically adjusted through the transportation of substance and energy.
Magnetorheological (MR) materials can be regarded as a kind of bioinspired smart materials because their viscoelastic properties can be easily adjusted by an external magnetic field. Magnetorheological materials can be generally classified into MR fluids, MR elastomers, and MR gels according to the type of the carrier matrix and the physical state in the absence of magnetic field [2, 3, 4]. The MR fluid-based practical devices mainly include damper, buffer, clutch, artificial muscle, and so on . Some application examples of MR fluid working under different modes can be found in various dampers, which take MR fluid as working medium. Besides, MR fluid has also found wide application potential in the fields of thermal conduction , sound transmission , precision machining , and biomedicine . The applications of MR elastomer have been widely reported in the fields of adaptive tuned vibration absorber , impact absorber , active noise abatement barrier system , vibration isolator , sensor [14, 15, 16], and so on. MR elastomer mainly works by changing its modulus through magnetic field during pre-yield stage, which shows different working mechanism with MR fluid (MR fluid mainly works at post-yield stage). The examples for the application of MR gel are relatively less in comparison with MR fluid or MR elastomer, but the unique magneto-induced phenomena have attracted more and more attentions; some work concentrating on the potential applications of MR gel have been reported [17, 18, 19, 20].
Here, we will give a brief introduction to different kinds of MR materials, discuss the related experimental and theoretical work when investigating the MR mechanism, and finally propose some future prospects for these magneto-sensitive smart materials aiming at practical applications.
2. The development of magnetorheological materials
2.1 Magnetorheological fluid
Magnetorheological (MR) fluid is the earliest developed magneto-sensitive smart material, which is a particulate suspension by mixing micrometer-sized ferromagnetic fillers, non-magnetic fluid, and some additives together. After applying an external magnetic field, the MR fluid will change from Newtonian-like fluid to semi-solid material quickly (within several microseconds) , as shown in Figure 1a . The randomly dispersed magnetic fillers are rearranged to form chain-like ordered microstructure through the magnetic interaction. Moreover, the ordered degree of the microstructure is relevant with the magnetic field strength. That is, a stronger magnetic field will induce a more ordered chain-like microstructure parallel with the direction of external magnetic field (Figure 1b) .
The rheological measurements indicate that MR fluid shows Bingham fluidic behavior under magnetic field, an obvious yield stress exists, and the maximum of yield stress has exceeded 100 kPa . Moreover, the apparent viscosity of MR fluid changes typically 3–4 orders of magnitude by changing the magnetic field strength, presenting a typical MR effect. However, the sedimentation problem due to the density mismatch between carrier matrix and ferromagnetic fillers become one of the bottlenecks to hinder the development of MR fluid. To solve the problems of particle sedimentation and the re-dispersion after the particle aggregation in the carrier matrix, many effective methods have been proposed. Generally, these methods can be classified into two main categories from the aspects of filler and carrier matrix.
Carbonyl iron particle is an ideal candidate to prepare MR fluid due to its low coercive force and high saturation magnetization (μ0Ms = 2.1 T). However, a serious sedimentation problem exists in the MR fluid with carbonyl iron particle. Sometimes, it has to abandon carbonyl iron particle with excellent magnetic property and choose some other magnetic material which could improve the sedimentation of MR fluid for the balance between performance and stability.
Decreasing the size of magnetic fillers is an effective method to improve the stability of MR fluids. Submicron- or nanometer-sized particle shows better stability in the non-magnetic carrier matrix in comparison with the micrometer-sized particle because of the Brownian movement and Van der Waals force. Especially, the particulate suspension totally using nanometer-sized ferromagnetic fillers as dispersed phase is named as magnetic fluids or ferrofluids [25, 26, 27, 28, 29, 30, 31, 32]. Each ferromagnetic filler in ferrofluids includes single magnetic domain and could disperse in the carrier matrix randomly due to the Brownian movement, so the sedimentation is greatly improved. However, the ferrofluids keep their liquid-like state even under a strong magnetic field, which indicates that it is impossible for ferrofluids to have a high magneto-induced yield stress. In addition, the particle aggregation caused by the particle’s nanometer size (or the re-dispersion of particles after removing the magnetic field) is another challenge to promote the further development of ferrofluids . Using the magnetic material with the shape of rod-like or fibroid is regarded as another effective method to improve the stability and MR performance of MR fluids .
Except for changing the size and shape of ferromagnetic fillers, the core-shell structured ferromagnetic particle, whose surface is chemically modified by various polymers, is also a good candidate. The core-shell structure not only decreases the density of the particle but also increases the static electrical repulsion between adjacent particles, so the stability and the redispersibility of MR fluid are evidently improved. Moreover, the antioxidation is improved because the surface of the particle is wrapped by polymer . Figure 2 shows the SEM images of carbonyl irons wrapped by various polymers, which were mainly made by Choi’s research group at Inha University.
It is a new approach to balancing the stability and performance of MR fluid by dispersing the submicron- or nanometer-sized ferromagnetic fillers (such as nanotube, submicron- or nanometer-sized carbonyl iron particle, wrought monox, organic clay, clavate ferromagnetic Co-γ-Fe2O3, and CrO2) into conventional MR fluid to change the property of continuous phase (i.e., the matrix) [36, 37, 38, 39]. Both of the sedimentation rates of the dispersed phase and the MR effect are improved significantly due to the existence of ion. However, the modification to the carrier matrix, together with the modification to the dispersed particles, could only improve the sedimentation of MR fluid to some extent. To solve the particle sedimentation completely, the non-magnetic liquid matrix can be totally substituted by rubber-like polymer matrix. Thereout, a new magneto-sensitive soft material, that is, MR elastomer, appears later.
2.2 Magnetorheological elastomer
MR elastomer presents solid state even without magnetic field; it inherits the magneto-sensitive feature of MR fluids, but its working principle and application field are quite different from MR fluid. The magnetic fillers are fixed in the polymer matrix after the MR elastomer is prepared, the particles cannot move freely even exposed in a magnetic field, and no “phase transition” appears like happened in MR fluid. MR elastomer carries out the intelligent control mainly through changing its damping and modulus by magnetic field before yield . The ordered chain-like (or column-like) microstructure aligned parallel to the direction of magnetic field generates if an external magnetic field is applied during the vulcanizing process of the polymer matrix. After vulcanization, the ordered microstructure can be solidified in the matrix, and the anisotropic MR elastomer is obtained.
Figure 3 shows the SEM images of MR elastomers pretreated by different magnetic fields. It is clear that chain-like structured anisotropic MR elastomer can be prepared if it is exposed under an external magnetic field during the pre-configuration process. The structure of particle chains can be further adjusted by the magnetic field. The ferromagnetic fillers aggregate more easily under a strong magnetic field, resulting in a higher degree of anisotropy of MR elastomer. Further magnetorheological characterization indicates that the MR elastomer with higher degree of anisotropy also possesses high MR effect . So far, many kinds of rubber, such as natural rubber , silicon rubber , polyurethane rubber , cis-polybutadiene rubber , nitrile butadiene rubber , and thermoplastic elastomer blended by polypropylene and SEBS , have been chosen as the candidates for fabricating the MR elastomer.
Although the particle sedimentation is completely solved, the magneto-induced effect and MR effect constrain each other, making the requirement of engineering application not easy to be achieved. Moreover, MR elastomer loses the feature that the particulate microstructure can be easily controlled by magnetic field as like in MR fluid because the ferromagnetic fillers are fixed in the rubber matrix, which indicates that it loses the magneto-controllable flexibility. To pursue a stable MR material with a high MR effect and a strong magneto-induced effect aiming to the engineering application, it needs to abandon the conventional fabricating solutions and redesign a new magneto-sensitive smart material.
2.3 Magnetorheological gel
MR gel is another magneto-sensitive smart material whose continuous phase is viscoelastic. The inelastic matrix makes MR gel present typical viscoelastic characteristics even without external magnetic field. Shiga et al. firstly proposed the concept of MR gel in 1995 , and they prepared a series of MR gels with different particle contents by dispersing ferromagnetic fillers into silicone gel and investigated the magneto-dependent viscoelastic behaviors and microstructures of MR gel. The MR gels can be further classified into liquid-like and solid-like MR gels according to their physical state without magnetic field.
The liquid-like MR gels can be regarded as a kind of special MR fluid with a little mount of polymer solution as additive. The polymer additive can generate a network structure in the matrix to modify the interfacial characteristic of ferromagnetic fillers and their interaction, greatly slowing down the sedimentation velocity of ferromagnetic fillers [48, 49, 50]. In comparison with MR fluids, except for improving the sedimentation stability, the off-state viscosity and yield stress of liquid-like MR gels can also be adjusted by adding a certain amount of polymer additives. However, the polymer network increases the moving resistance of ferromagnetic fillers in the matrix, and the response of MR gels to external magnetic field is then decreased accordingly. In addition, the sedimentation problem in the liquid-like MR gels is not completely solved.
Strictly speaking, the magnetic gel reported by Shiga et al. is a kind of solid-like MR gels . The most distinct characteristic of solid-like MR gels is that there is no particle sedimentation problem exists, like MR elastomer. Yet the matrix is not the rubber-like elastic material, the solid-like MR gel cannot be classified into MR elastomer. Recently, these solid-like MR gels have been paid more and more attention [51, 52, 53, 54, 55, 56, 57]. A novel solid-like MR gel by mixing micrometer-sized magnetic particles and plasticine-like polyurethane was reported by Xu et al. . As Figure 4a shows, this material presents like plasticine without magnetic field, can be changed into any shapes, and remains the status of plastic deformation, so it is named as MR plastomer. MR plastomer deforms along with the direction of the applied external magnetic field (Figure 4b). Further microstructure characterization indicates that the randomly dispersed magnetic particles can rearrange to generate chain-like (or column-like) orientated microstructure driven by magnetic force (Figure 4c and d). In addition, the anisotropic particulate microstructure is kept even the external magnetic field is removed .
In one word, an orientated particulate microstructure in the solid-like MR gel can be adjusted through an external magnetic field. Meanwhile, the chain-like (or column-like) microstructure can be fixed in the soft matrix after removing the magnetic field. This unique feature makes solid-like MR gel process the merits existed on MR fluid and MR elastomer (i.e., movability of particles and the “frozen” property of orientated microstructure) at the same time, which is significant to investigate the magneto-mechanical coupling mechanism.
2.4 Other magnetorheological materials
Some other special MR materials, which cannot be simply classified into the most well-known MR materials as mentioned above, were reported in the literature. MR foam is a kind of solid-like polymer composite by pouring MR fluid into porous polymer foam (Figure 5); the modulus of the MR foam can be controlled by changing the rheological property of MR fluid through a magnetic field [60, 61, 62]. Due to the special porous microstructure, MR foam presents the merits of lightweight, controllable modulus, excellent sound-absorbing property, and so on .
To solve the problem of particle sedimentation for MR fluid, Park et al. prepared a kind of novel MR material with excellent sedimentation resistance ability by substituting the fluidic matrix of MR fluid with commercial grease, and they named this MR material as MR grease . MR grease shows typical Bingham fluid behavior; so strictly speaking, MR grease can be regarded as a special MR fluid. Byrom and Biswal reported a colloidal material system by adding micrometer-sized paramagnetic and diamagnetic particles into ferrofluid . Different from the conventional MR fluid, the particles do not generate a chain-like orientated structure parallel with the direction of magnetic field but a fractal net-like microstructure in 2D direction. Further analysis indicated that the fractal net-like microstructure is induced by the magnetic dipole interaction between paramagnetic and diamagnetic particles, and the fractal dimension of the particle aggregates can be controlled by adjusting the concentration of ferrofluid and the ratio of paramagnetic and diamagnetic particles.
A multifunctional magnetic plasticine™ was developed by Xuan et al. , and they chose paraffin wax petroleum jelly as the matrix. Except for the high magneto-induced G′ (4.23 MPa) and MR effect (305%), magnetic plasticine™ can be switched between liquid-like state and solid-like state by changing the temperature, which greatly enhances the regulation ability. Shahrivar and de Vicente also reported a thermo-responsive polymer-based magneto-sensitive material , which can easily achieve phase transition by changing temperature. Figure 6a depicts that “liquid-to-solid” transition with increasing temperature appears in the MR composite with PEO-PPO-PEO solutions because a repulsive colloidal glass generates, while an inverse temperature-driven phase transition can be achieved for MR composite with P-NIPA microgel dispersions (Figure 6b). Besides, the critical temperature of phase transition can be changed by tuning polymer concentration. The multi-responsive MR material is a good effort in the frontier between conventional MR fluid and MR elastomer.
3. Magneto-sensitive properties and MR mechanism
The magnetic field usually leads to a structural rearrangement in soft MR material, and this process has significant influence on the physical properties of soft MR material. Due to the weak restriction of polymer matrix to the ferromagnetic fillers and complexity of polymer matrix, the responses of MR gel to external stimuli are more complicated than those of MR fluid and MR elastomer. For this reason, MR gel presents some unique magneto-electro-thermo-mechanical coupling phenomena. However, the realization on the coupling mechanism of MR gel is far from enough in comparison with those of MR fluid and MR elastomer, and more efforts need to be made through experimental and theoretical studies. Tight correlations exist between these three MR materials; so, there are some similarities in MR mechanism, and we can use the characterization techniques and theoretical models of MR fluid and MR elastomer for reference when studying the MR mechanism of MR gel. Next, we will briefly discuss the characterization methods and theoretical studies for different MR materials.
3.1 Experimental characterization of MR materials
Experimental characterization of MR materials can not only quantitatively evaluate their performance but also provide the necessary parameters for theoretical research or certify the accuracy of the theoretical results, which is the foundation for investigating the MR mechanism. The magneto-induced rheological properties of MR materials under different loading conditions (quasi-static shear, tensile, compressive loading, dynamic shear, and squeeze loading) are the most important properties, and this is the primary reason for naming this magneto-sensitive smart material as MR material. The influences of relevant factors (i.e., magnetic field, temperature, PH value, particle concentration, shape, size, and so on) on rheological properties were also widely investigated. Besides, the magnetization, electrical conduction, thermal conduction, and magnetostriction of MR materials are studied as well.
The rheological property of MR materials under shear loading is the most used characterization parameters at present. Many famous commercial rheometers, like the Physica MCR rheometer from Anton Paar Company and Discovery hybrid rheometer from TA Company, are designed for the rheological characterization under shear loading.
The magneto-dependent rheological behavior of MR fluid is usually described by Bingham model:
Both of the solid-like and liquid-like MR material can be considered as the viscoelastic material, and the dynamic mechanical analysis under oscillatory shear is one of the most important characterization methods for viscoelastic materials. Normally, applying a sinusoidal shear strain to the viscoelastic material, if the amplitude of the strain is small enough, a sinusoidal response stress at the same frequency but a specified phase shift can be obtained; then, we define the dynamic mechanical properties (i.e., storage modulus G′, loss modulus G″, and loss factor tanδ) of material within the linear viscoelastic (LVE) range as the ratio of response stress to actuation strain in the complex plane. Dynamic mechanical properties are frequently used characterization parameters for investigating the magneto-induced microstructure evolution mechanism of MR materials. For the practical application, most MR materials in the devices are working under the oscillatory shearing mode. More importantly, both solid-like MR elastomer and liquid-like MR fluid can be characterized by dynamic mechanical analyzer (DMA) [71, 72], which indicates that dynamic mechanical analysis can be considered as a universal method to characterize MR materials. Therefore, as the intermediate material system between MR elastomer and MR fluid, the magnetorheological properties of MR gel are mostly studied by DMA .
The oscillatory shear mode can be further classified into simple shear and rotating shear according to different measurement principles of commercial devices. Figure 8a shows a typical DMA (Tritec 2000, provided by the Triton Technology Co. Ltd., UK). If an external magnetic field generator is added (Figure 8b), the magneto-mechanical coupling behaviors of MR elastomer under oscillatory simple shear mode can be investigated . The deformation of the sample under simple shear mode is uniform, which is valuable for theoretical analysis. The rheometer can also be used for dynamic mechanical analysis. Figure 8c shows a parallel-plate rheometer (Physica MCR 301, Anton Paar Co., Austria) equipped with a MR accessory (MRD 180), which provides a controllable magnetic field when carrying out a rotating shear experiment (Figure 8d). The deformation of the sample under rotating shear mode is inhomogeneous (the shear strain increases linearly in the radial direction of disc-like sample; the shear strain at the center of the sample is zero). Although with different measurement principles, the measurement results obtained from these two kinds of devices show little difference if the amplitude of the actuating strain is small enough. Besides, the magneto-dependent creep and recovery [75, 76, 77] and stress relaxation behaviors  of MR materials under shear loading are very helpful for investigating the magnetorheological mechanism and can be tested with the modified DMA and the rheometer as mentioned above.
The modulus variation of ferromagnetic filler-doped polymer composite can be reflected from the compressive and tensile properties of MR elastomer, which are also frequently used characterization parameters. Bellan and Bossis investigated the influences of magnetic field, particle concentration, and particle distribution on the tensile property of silicon rubber-based MR elastomer . The compressive properties of MR elastomer with different particle distributions (randomly dispersed isotropic and chain-like orientated anisotropic structures) and its magnetic field dependency were investigated by Varga et al., as shown in Figure 9. It is found that the compressive modulus of MR elastomer is not only affected by the particle distribution (i.e., the compressive modulus of anisotropic MR elastomer is larger than that of isotropic one under the same loading condition) but also by the magnetic field and loading direction. When the directions of magnetic field, particle chain, and compressive loading are parallel (i.e., the middle test condition in the second row of Figure 9), the largest compressive modulus and magneto-induced effect of MR elastomer were observed . In addition, the mechanical properties of MR elastomer under oscillatory squeezing mode were reported by Kallio et al. and Koo et al., respectively [81, 82], which provide valuable experimental data for the application of MR elastomer.
In recent years, many people pay attention to the rheological behaviors of MR fluid under tensile or squeezing loading, and the results suggest that the yield stress of MR fluids is significantly enhanced due to the squeeze-strengthen effect [83, 84, 85]. However, the tensile and squeezing behaviors of MR gel are rarely studied to date. Therefore, Xu et al. systematically investigated the squeeze flow behaviors (including quasi-static compressive and tensile behaviors and oscillatory squeeze behaviors) of MR gel . It was concluded that the squeeze flow curve of the solid-like MR gel can be classified into three different deformation regions: elastic deformation, stress relaxation, and plastic flow regions. Yield stresses under both tension and compression are sensitive to the particle distributions, the filler concentration, and the magnetic field. In addition, the magneto-sensitive properties of MR elastomer and MR gel under impact compression were also studied [11, 87]. The compressive modulus can still be strengthened by magnetic field even at high strain rate.
Most magnetic fillers (such as carbonyl iron particles , nickel particles , and Fe3O4 particles covered by silver ) are conductive at the same time, so most MR materials also belong to conductive polymer composite. The conductivity of this kind of magneto-sensitive conductive polymer composite is adjusted through external magnetic field except for the particle distribution and particle concentration, presenting a typical magnetoresistance effect [91, 92, 93]. Impedance spectroscopy testing is a nondestructive method to quantitatively detect the evolution of the microstructure, which is suitable for analyzing the microstructure evolution mechanism and the interfacial feature of material. Figure 10 shows a typical experimental setup to test the magneto-sensitive impedance spectroscopy of conductive polymer composite. With this magneto-electrical coupling measurement system, the structure-dependent (Figure 11a) and the magneto-induced (Figure 11b and c) impedance spectroscopy are obtained, and the microstructure-dependent conduction mechanism (Figure 11d) can be further analyzed based on the related experimental results .
Besides, the investigations on the antioxidation , durability , and thermal conductivity  are helpful to the deep understanding on the magneto-induced mechanism of MR materials as well as some specific practical applications.
3.2 Magnetorheological mechanism
Magnetorheological effect essentially originates from the discrepancy of magnetic permeability between the continuous phase (the carrier matrix) and the dispersed phase (ferromagnetic fillers). Particular magnetization model (i.e., magnetic dipole model) is the most popular microstructural model to explain the magneto-induced effect of MR fluid . If we ignore the multi-body magnetic interaction between particles (i.e., only the magnetic interaction between adjacent particles in a single particle chain is considered) and the multidirectional magnetization in a single magnetic particle (i.e., simplify the micrometer sized ferromagnetic particles as magnetic dipole), the magnetic moment of spherical ferromagnetic particle within the linear magnetization range is:
When it flows, the rheological properties of MR fluid are related to
As the most important rheological parameter of MR fluid, the magneto-induced yield stress can generally be explained from macroscopic and microscopic aspects. The macroscopic theoretical model is usually derived according to the minimum principle of energy. It assumes that the ferromagnetic fillers are spherical, cylindrical, or layered and are dispersed evenly in macroscopic theoretical model . These models based on the sub-microstructure only consider the anisotropy of particle aggregation under small strain while the microscopic models consider the interaction between magnetic particles . Most microscopic models ignore the interaction between the structured particle chains and believe that the magnetic interaction between adjacent particles is the main source of yield stress. Therefore, the yield stress of MR fluid can be well predicted when particle content is relatively low, but the assumption is untenable at high particle concentration, which makes a big deviation between theoretical and experimental results.
Figure 12 demonstrates the schematic of classic single-chain magnetic dipole model. When the material deforms by shearing, an affine deformation happens on the particle chain accordingly, which means that the particle moves horizontally along the direction of arrows as shown in Figure 12a. For this affine deformation, the distance between adjacent particles is identical before and after deformation. This assumption simplifies the deduction of magneto-induced yield stress. The magneto-induced shear yield stress of MR fluid within the linear magnetization range can be obtained based on the affine deformation assumption:
In the saturated magnetization range, yield stress can be expressed as:
The details for the deduction process of magneto-induced yield stress and the explanation of relevant parameters can be found in the review article about the magnetorheological mechanism written by Bossis et al. .
The abovementioned single-chain magnetic dipole model was introduced directly into MR elastomer by Jolly et al. . They predicted the magneto-induced elastic modulus by this model, and the theoretical results fit well with the experiment. Davis also calculated the magneto-induced shear modulus by this model, and he found that the magneto-induced shear modulus reaches a maximum if the volume ratio of the ferromagnetic fillers is 27% . However, the influence of magnetized particle on the surrounding particles is not considered by the magnetic dipole model, and the bias of theoretical results from the fact is growing larger with the increasing particle concentration. Shen et al. realized this problem and modified the single-chain magnetic dipole model by considering all of the interaction of the particles within a single chain, which is more in line with the real situation . A finite-column model based on the experimental results was proposed by Chen et al. . However, this model can only predict the magneto-induced modulus of MR elastomer with low particle concentration.
The abovementioned models concentrate on the magnetic interactions between particles, but different from the MR fluid, a strong constraint effect exists between rubber matrix and magnetic particles for MR elastomer. This constraint will influence the magnetic interactions between particles to some extent. Therefore, the theoretical model of MR elastomer considering the coupling effect between rubber matrix and particles is more reasonable. Chen and Jerrams developed a more general magneto-mechanical coupling model of MR elastomer, which includes the magneto-induced mechanical property of particles, the interfacial slipping effect between ferromagnetic particles and rubber matrix, and the viscoelastic properties of rubber matrix . This model could predict the dynamic mechanical properties of MR elastomer with different particle content or different kinds of rubber matrix, revealing the response mechanism of material to external magnetic field. It is a tendency in recent years that constructing the magneto-mechanical coupling model of MR elastomer bases on the theory of continuum medium mechanics , more details about the research progress on the theoretical modeling of MR elastomer can be found in the recent review article . Although the numerical results can be obtained after complex mathematical derivation, these theoretical models can deeply reveal the complicated magneto-mechanism coupling mechanism of MR elastomer, which has guiding significance for the optimal design and the practical application of this smart material.
A lot of work has been done on the magnetorheological mechanism of MR fluid and MR elastomer, yet there are little reports on the magnetorheological mechanism of MR gel. On the one hand, MR gel (especially for the solid-like MR gel) has not attracted wide attentions as a new MR material, and the research on it is not enough. On the other hand, the investigation on the magnetorheological mechanism of MR gel is more difficult than those of MR fluid or MR elastomer due to its intrinsic complex MR characteristics. MR gel possesses both the characteristics of mobility of magnetic particles in MR fluid and the stability of oriented microstructure in MR elastomer. These two features are “contradictory” to some extent, but they indeed exist in solid-like MR gel at the same time. Although the magnetic particles are moveable in the carrier matrix of MR gel, the clustering phenomena of particles in MR gel cannot be interpreted by the theory used in MR fluid because the viscous resistance of polymer matrix is far larger than the resistance from the carrier fluid in MR fluid. It is mean that the Mason number of MR gel is far larger than that of MR fluid, the assumption in fluid is invalid in MR gel. In the meantime, the viscous resistance of polymer matrix to the particle is much less than the constraining force of the rubber matrix to the particle in MR elastomer. After applying a magnetic field, the “solidified” ferromagnetic fillers in MR elastomer can only move slightly from the original position, while the ferromagnetic fillers in MR gel can greatly move under a strong magnetic field and a large applied loading; if the direction of magnetic field is changed, the ferromagnetic fillers can even rearrange to generate chain-like or column-like structure along the new direction of magnetic field. These interesting characteristics that reflect the complexity of MR gel, the rheological behavior of polymer matrix, the magnetic interaction between adjacent fillers, and the interfacial problem due to the relative movement of particle and matrix have to be considered when studying the magnetorheological mechanism of MR gel. In addition, the “huge” change of microstructure after the rearrangement of particles will also make the modeling of the magneto-mechanical coupling behavior of MR gel more difficult.
It is not easy to fully describe the complicated magneto-mechanical coupling behaviors of MR gels. A field theory was developed by Han et al. to describe the magneto-sensitive viscoelasticity of ferrogel based on the principles of non-equilibrium thermodynamics . The responses of ferrogel to different magnetic fields were analyzed by numerical calculation, and the theoretical results consistent with the experimental results under the cyclic magnetic field, which indicates that this theory is reasonable to some extent for the realization to magneto-mechanical coupling mechanism of MR gel. Zubarev evaluated the free energy of ferrogel after tension or compression along with the magnetic field direction by standard methods of statistical physics . The analysis demonstrates that the magnetic field strength, the initial shape of the sample, as well as the particle concentration and the magnetic properties of particles determine the type of magneto-induced deformation (i.e., extension or shrunken). A particle-level molecular dynamics model was employed by Liu et al. to investigate the particle evolution in MR gel under a stable uniform magnetic field . A modified magnetic dipole model is introduced to describe the magnetic interaction between adjacent particles, and this model presents higher precision than classic magnetic dipole model when processing the magnetic interaction of particles close to each other. The rheological behavior of the carrier matrix is described by the Bingham plastic model (Eq. (1)). Some complicated loading methods of magnetic field (such as the rotating magnetic field, as shown in Figure 13), which are difficult to be achieved by experiment, can be easily applied through simulation. With this, the 3D evolution of particular microstructure under complicated magnetic field loading conditions can be obtained, which is very important to understand the microstructure evolution mechanism of MR gel. The microstructure obtained by the particle-level molecular dynamics model matches well with the results by experimental observation under the same loading condition. However, the coupling effect between ferromagnetic fillers and carrier matrix is not considered in this model, and the Bingham plastic model is also too simple to describe the complicated rheological behavior of the carrier matrix; so, the governing equations which describe the physical behaviors of different components within the MR gel need to be further developed.
4. Conclusions and prospects
As a smart material whose physical properties can be easily controlled, magneto-sensitive composite (i.e., MR material) attracts more and more attentions in recent years. Many works concentrating on the magnetorheological mechanism and application have been reported. Various MR materials aiming at different practical applications were developed, which shows great application potential.
However, the inherent defects existed in conventional MR materials (e.g., the particle sedimentation in MR fluid, the microstructure control of MR elastomer, the bearing capacity of MR gel as structure unit) preclude their wide application. To this end, from the perspective of material preparation, on the one hand, we need to further improve the conventional MR material aiming at the inherent defects; on the other hand, the novel magneto-sensitive material system which meets the requirements of engineering applications should be developed, which means that we could develop multifunctional smart composite that has the magneto-controllable feature (e.g., magneto-sensitive impact-resistant composite, magneto-sensitive conductive composite, magneto-sensitive heat-conducting composite, and so on). From the perspective of mechanism, magneto-sensitive soft material refers to magneto-electro-thermo-mechanical coupling behavior, and it is difficult to describe the response to external stimuli. The difficulties can be summarized as follows: the description of the exact distribution state of dispersed phase before and after exposed under a magnetic field; the description of the discrepancy of size and shape of the dispersed ferromagnetic fillers; the interaction model between the dispersed phase and the continuous phase; the construction of constitutive model of the polymer matrix in the MR elastomer or solid-like MR gel; and the unification of multiscale model from microscale to macroscale. Considering the complexity of true situation, some necessary simplifications have to be made aiming at specific problem; then, the simplified model which could generally reflects the specific mechanism can be developed after ignoring the secondary factors. The numerical simulation is another effective method to investigate the microstructure evolution mechanism of MR material. It is an important research direction to construct the constitutive model of MR material, which could accurately describe the complicated coupling responses to different stimuli (magnetic field, temperature, strain rate, and so on). It is believed that the engineering applications of magneto-sensitive multifunctional material will be more widely concerned with the further realization on the magnetorheological mechanism and the enhancement of the performance of the material.
The research reported in this publication was supported by National Natural Science Foundation of China (Grant nos. 11502256, 11502255, 11602242), and the key project “Computational Solid Mechanics” of the China Academy of Engineering Physics. The authors gratefully acknowledge Professor Xinglong Gong and Professor Shouhu Xuan at University of Science and Technology of China for their help on beneficial discussion.


Updating the Quattro Logger USB-Chip
Problem and Solution
The problem: The 64-bit versions of Vista and Windows now require "signed drivers" for USB ports. These versions of Windows will not accept the uncertified drivers supplied by DGSI. To address this problem, we have decided to use the solution provided by FTDI, the USB chip manufacturer.
Solution for new loggers: All new loggers will use USB chips with an FTDI "ID." We will also distribute FTDI drivers with our Logger Manager program. Of course, this does not solve the problem with older loggers.
Solution for older loggers: We have a two-part solution for older loggers. Part 1 is to update the ID on the USB chip. Part 2 is to install the latest version of the Logger Manager program.
Part 1: Updating the USB Chip
- Use a PC with 32-bit Windows for this update. 64-bit Windows will not work.
- Download “usb-update.zip”.
- Unzip the file. Open the folder and double-click the file “usb-update.bat” to start the update.
- The 32-bit USB drivers will be preinstalled. You may be notified that the drivers are unsigned. Click Continue.
- Unplug USB devices connected to your PC. Your USB mouse can be left connected.
- Then connect the Quattro Logger to a USB port on your PC. The “Found New Hardware” wizard will start. You may be notified that the drivers are unsigned. Click Continue.
- The wizard completes the installation of the drivers. Click Finish.
- Now, press any key. This starts a program called MProg.
- Choose a Device. Then choose Scan. The status window at the bottom should show “Number of Programmed Devices= 1”. That device is the Quattro Logger. If the number of devices is greater than one, there is some other device still connected. Disconnect that device and run the Scan command again.
- Choose File. Then Choose Open. Select VWQuattro_FTDI_Pgm_B.ept” and click Open.
- Choose a Device. Then choose Program. This will program the USB chip. The status window at the bottom should show “Programmed Serial Number SI00BE41”.
- The USB chip has been updated. If you have another Quattro Logger, connect it to perform the same update. Otherwise, choose File - Exit.


INSPEC provides access to the published literature in physics, electrical/electronic engineering, computing, control engineering and information technology. Its print counterparts are : Physics Abstracts, Electrical and Electronics Abstracts, Computer and Control Abstracts. The database is designed to assist engineers, scientists and others to:
- locate relevant journal articles, conference papers and other documents in response to specific queries
- maintain a continuing awareness of the latest published information in any particular field (within the above disciplines)
The database covers the time span 1898 to present. An alternative source, available online, is PROLA covering the complete set of articles published in Physical Review (1893- ). In general, the database offers the customer bibliographic records with abstracts and full details of the source document which can be located by using the CERN Library catalogue or obtained via our interlibrary loan service.


Tutorial on How Mobile Phone Jammer Works
Spot jamming is concentrated power routed toward one channel or frequency. Barrage jamming is power spread over several regularities or networks at the same time.
a. Obvious obstructing. This is generally very basic to discover. The even more typically used jamming signals of this kind are explained listed below. Do not try to memorize them; simply understand that these and others exist. When experiencing a jamming occurrence, https://needed.ca/an-introduction-to-jammers-and-jamming-techniques-2/ it is more crucial to identify and get over the event than to identify it formally.
Mobile phone jammer
Stepped tones are generally made use of against single-channel AM or FM voice circuits. (3) Spark. The spark signal is conveniently produced and is among one of the most reliable for jamming. Ruptureds are of brief period as well as high intensity. They are duplicated at a fast rate. This signal is effective in interrupting all types of radio communications.
For instance, if we have an AN/PRC -77 in the SQUELCH setting and https://resportour.com/Groups/tutorial-on-how-mobile-phone-jammer-works also an AN/VRC -12 collection radio in the NEW SQUELCH ON setting and also they receive a jamming signal without the 150-hertz tone, the receivers of these radios will not be triggered by any type of signal as long as the jamming signal is more powerful than any type of various other signal being received.
The key Elements of communication jamming. How can .
Threat jammers may use noticeable or fizkult.site refined jamming methods. Likewise, interference might be triggered by resources having absolutely nothing to do with adversary jamming. Interference might be brought on by the following: Unintentionally by various other radios (friendly and opponent). Various other electronic or electric/electromechanical equipment. Breakdown of the radio. A combination of any one of the above.
The two sources of disturbance are inner and also exterior. If the disturbance or thought jamming can be eliminated or substantially decreased by basing the radio equipment or detaching the receiver antenna, Www.Vetrina-Eventi.Com the source of the disruption is probably outside to the radio. If the interference or suspected jamming continues to be after basing or detaching the antenna, the disturbance is more than likely interior as well as is triggered by a malfunction of the radio.
What is WiFi Jammer and Why You Might Need One
Relocating the receiving antenna for short ranges might trigger noticeable variations in the strength of the conflicting signal. Alternatively, little or no variation normally indicates adversary jamming.
b. In all situations, https://resportour.com/groups/tutorial-on-how-mobile-phone-jammer-works believed opponent jamming and any type of unidentified or Https://Resportour.com/groups/tutorial-on-how-mobile-phone-jammer-works unintended disturbance that disrupts our capability to connect have to be reported. This uses also if the radio driver has the ability to conquer the results of the jamming or disturbance. The style for reporting this details is the MIJI record.
What are GPS jammers and how do you combat them?
(c) An above normal level of noise or a certainly regulated signal might indicate that the radio is being obstructed by a noise-modulated jamming signal. The operator must momentarily separate the antenna. If normal fixed sound returns when the antenna is detached, the radio probably is being obstructed by a noise-modulated signal.
The operator ought to temporarily separate the antenna. If normal fixed sound returns, as well as the telephone call light goes off when the antenna is detached, https://needed.ca/4768-2/ there is a high probability that the radio is being obstructed by a noise-modulated signal. (d) If the above tests suggest that there is a high probability that the radio is being obstructed, the driver should comply with the regional SOP to improve interactions and also start a MIJI record educating higher head office of the case.
The Proliferation of Wireless Signal Jammers
Training and also experience are the most important tools operators have to identify when a particular signal is a jamming signal. The capability to acknowledge jamming is important, because jamming is an issue that requires action.
Stop for a minute as well as consider what the adversary is doing during his common jamming procedure. Typically, adversary jamming includes a duration of jamming complied with by a brief listening period.
Jamming Definition & Meaning
What we are doing throughout this short time period when he is paying attention will tell him just how efficient his jamming has been. If the operation is continuing in a normal manner, as it was prior to the jamming began, the opponent will think that his jamming has not been specifically efficient.
Due to the fact that the opponent jammer is checking our procedure this means, http://www.kominpub.cz/ we have a simple yet very important rule that uses when we are experiencing jamming. Unless or else bought, never ever closed down operations or Https://Resportour.Com/Groups/Tutorial-On-How-Mobile-Phone-Jammer-Works in otherwise reveal to the enemy that you are being detrimentally affected. This indicates normal procedures ought to proceed also when broken down by obstructing.
Jammer — Definition, Meaning & Synonyms
Boost the signal-to-jamming ratio. The signal-to-jamming proportion is the family member toughness of the wanted signal to the jamming signal at the receiver. Signal refers to the signal we are trying to obtain. Obstructing refers to the hostile or unknown disturbance being obtained. It is constantly best to have a signal-to-jamming ratio in which the desired signal is stronger than the jamming signal.
The most noticeable means to boost the signal-to-jamming proportion is to raise the power result of the transmitter discharging the preferred signal. In order to raise the power result at the time of jamming, the transmitter has to be established on something much less than complete power when jamming starts.
GPS Jammers Illegal, Dangerous, and Very Easy to Buy
Specific approaches that put on a certain radio set remain in the appropriate driver’s handbook. Depending on the antenna being utilized, a few of these methods are— Adjustment the antenna polarization. (Should be done by all stations.) Mount an antenna with a longer range. (4) Develop a retransmission terminal. A retransmission terminal can raise the range and power of a signal between two or even more radio terminals.
What jamming of a wireless security system is
Often, the signal-to-jamming proportion may be enhanced by relocating the antenna and linked radio collection influenced by the jamming or unidentified disturbance. It is best to transfer the antenna as well as linked radio set so that there is a surface function in between them as well as any kind of thought adversary obstructing location.
Radio frequency signal jammers
Make use of an alternate course for communications. In some instances, adversary jamming will certainly prevent us from connecting with a radio station with which we need to interact. If radio interactions have been broken down between two radio stations that need to communicate, there might be another radio terminal or route of communications that can connect with both of the radio terminals.
d. Modification frequencies. If an interactions web can not conquer opponent jamming making use of the above actions, https://fastcuci88.com the commander (or assigned agent) may route the net to be changed to an alternate or spare regularity. If functional, dummy terminals can continue to operate the regularity being jammed to mask the modification to an alternative regularity.


Due to the increasing pollution being generated from diesel and petrol-based transportation modes, several companies and governments have come forward with the idea of developing and using human hybrid electric vehicles. A human hybrid electric vehicle is a system that makes use of human power in an electric vehicle.
Human muscle power is reliable, almost free, and healthy to use. It helps in carrying out the daily activities with ease and comfort. Moreover, the potential of human power increases as the human population grows.
The advent of modern civilisation supported by the use of different machines and means of transportation has made mankind to stay away from using human muscle power.
Transportation is a non-separable part of any society, and it exhibits a very close relation to the style of life, range and location of activities, and goods and services that are available for consumption.
The growth in the transportation sector has made it possible to change the ways of living and how societies are organised and therefore have a great influence on the development of civilisations. Modern civilisation is totally dependent on different modes of transportation for not only travelling to different places but also for trading economic resources like raw materials, fuels, food, and manufactured goods from their place of origin to place of use.
The use of a bicycle, which is currently the only human-friendly, cost-effective, and pollution-free mode of transportation, has reduced just to an exercise device or for leisure trips. Transportation is a major source of air pollution as cars, trucks, and buses powered by fossil fuels are major contributors to air pollution. According to pollution studies, it is said that the transportation sector contributes to more than half of nitrogen oxides into the air and is a major source of global warming emissions.
Further, studies have also linked pollutants from vehicle exhaust to have adverse impacts on nearly every organ in the body. With the so-called progress of civilisation or modernisation, not only various types of transportation vehicles like automobiles (motorcycles, scooters, and cars), buses, trains, trucks, helicopters, watercraft, spacecraft, and aircraft have flooded the market, but also their general and personal purchase and use have reached a stage where they have become the biggest sources of unwanted environmental pollution.
Feeling concerned with degrading environmental conditions due to the pollution being generated from diesel and petrol-based transportation modes, several companies and governments have come forward with the idea of developing and using electric vehicles (EVs).
This shift was also possible due to reduced terminations, reconnections and arrearages, more stable electric energy prices, a more resilient and reliable electric energy system, lower transmission and distribution costs, and utility insurance savings.
There are a number of benefits of using EVs over conventional petrol/diesel vehicles like these are cheaper to run and maintain, better for the environment, use eco-friendly materials, and many more. The growing need for energy and degrading environmental considerations in the last few years have given direction to new paradigms of mobility and transportation with an increased interest in light electric vehicles (LEVs). In this context, electrically power-assisted cycles (EPACs) have received great attention. Several efforts have been made in order to improve their performance in terms of autonomy, weight, aesthetics, and feeling with the driver.
Technological developments taking place over the last few decades towards designing and developing efficient, long-lasting, and cost-effective batteries have also strengthened the move towards the emergence of EVs in the market. At present, only two-wheelers like scooters and motorcycles have been successful as electric vehicles, but it is expected that in the coming times, we will have fully electric buses, trucks, trains, and airplanes as well.
With the advanced batteries having more charge capacity, long life, and light weight, this will be possible. Over the last two decades, lithium-ion battery technology has worked its way to the forefront of the automotive market. But EV battery technology continually pushes the boundaries of lithium-ion batteries’ ability to provide ample power, longevity, and safety.
Fully battery-powered electric vehicles (BEV) rely exclusively on electric power to drive, while plug-in hybrid electric vehicles (PHEVs) and full hybrid electric vehicles (FHEV) work in tandem with ICEs to generate and provide power. All these vehicle types require different levels of battery complexity and size. Different EV vehicles demand different battery capacities.
While designing EV battery systems, engineers also consider charging speed, charge cycle ability, degradation, chemistry, and safety. Energy and power density thresholds have been realised in most EV applications, yet vehicle manufacturers are constantly tweaking module and cell sizes for optimum performance levels. Regardless of the lithium-ion battery cell and module sizes, the high-voltage battery systems that power EVs require meticulously designed battery management systems (BMS) to ensure maximum power and safety.
Human hybrid electric
Human-powered transport means to make use of human muscle power for the transport of person(s) and/or goods. This was the only system of transportation before the invention of the steam engine by James Watt, which then contributed substantially to the industrial revolution. With time, motorisation has increased speed and load capacity, but still human-powered transport in many of its forms remains popular due to several reasons such as cost and convenience.
While showering praise on EVs, we ignored the effects of ever-increasing pollution that is being produced during the generation of electric energy, an essential requirement to charge batteries of EVs as well as in the manufacturing of batteries. In order to minimise this impact, engineers are thinking to imbibe human power in electric vehicles by developing human hybrid electric vehicles.
A human hybrid electric vehicle is a system that makes use of human power in an electric vehicle called a hybrid human-powered vehicle, whose drivetrain consists of a person, an electric motor/generator, and one or more electricity storage device(s). Many developments have already taken place towards the development of human hybrid electric vehicles, and time is not far when we will have such transport vehicles all around us.
1. TWIKE (a Tesla company project) is the world’s oldest only human electric hybrid car. This car was developed and produced initially in Switzerland, but then production moved to Germany after the initial investors became insolvent in 2002, and a group of German importers joined together to purchase the equipment and continue with TWIKE production under the company named FINE Mobile.
TWIKE is an ambitious concept today as it was back when it first became a rare oddity in the world of transportation. Presently, instead of a standard steering wheel, navigation of the car is done through a joystick. Under the driver’s feet is the direct drive pedal power system, which transfers human power input straight to the drivetrain. The system also captures energy from regenerative braking. At higher speeds, the vehicle is powered mostly by onboard lithium-ion batteries. The top speed reported to be achieved with the car at present is around 89 to 104 kilometres per hour.
Similar projects are continuously being reported by various companies. For instance, a Minnesota-based company has built a three-wheeled hybrid electric vehicle weighing about 317kg that gets 121km per charge, and the vehicle is street legal and considered a motorcycle. Its carbon fibre chassis looks like a kayak and is reinforced with structural foam, similar to an airplane. The vehicle uses a regenerative brake system, which feeds the electricity back into the batteries when the brakes are applied. It also has a solar panel mounted on the roof.
2. An electric motorbike with pedals, eRockit (developed and produced in Hennigsdorf in Brandenburg, Berlin), is described as a ‘human hybrid’ as it’s powered by a combination of human and electric drives. The eRockit puts the rider back into the centre of mobility of moving, depending on the rider’s wish. Further, the use of a smart pedal concept gives the rider an opportunity to act with a human hybrid bike more conveniently and comfortably.
The bike’s clutch-free and intuitive pedal power system makes eRockit safe to drive. It is an emission-free ride with a hundred per cent emotion.
The bike can reach a speed of close to 55.9mph, and its battery range is over 120 kilometres. With this new technology of human hybrid electric vehicle, a person can travel between 5km and 45km every day together with fun riding. About thirty prototypes have already been tested for more than 100,000 kilometres in total, and the market version will be available soon.
In a world that is wholly dependent on transportation on one hand and fossil fuels on the other, harvesting human kinetic energy along with the future of efficient, light, cost-effective electric vehicles will provide an era of environment-friendly and healthy transportation mode—human hybrid electric vehicles. By using a pedal-assisted drivetrain system, we will be able to reduce the consumption rate of battery power by the motor, which will increase the battery life.
The reason why many people are inclined towards conventional vehicles is that they can reach places without having to do more than pressing on the gas pedal. In short, developing people-friendly human hybrid electric vehicles will definitely prove to be an attractive mode of transportation in the future.
Dr S.S. Verma is professor at Department of Physics, Sant Longowal Institute of Engineering and Technology, Sangrur, Punjab


Washington, May 25 (ANI): The next generation of Mars rovers could have smaller, cheaper, more robust and more sensitive life-detecting instruments-all thanks to a new invention by scientists at the U.S. Department of Energy's Idaho National Laboratory.
The INL team has come up with an efficient new way to generate complex electric fields, which will make it easier to direct ions, or charged particles, along specified paths.
The researchers have now filed a patent application for their Total Ion Control method, a key advance in the field of mass spectrometry.
Equipment based on TIC could make the Mars Organic Molecule Analyzer (MOMA) - part of the ExoMars mission scheduled for launch in 2018 - a better life-detecting tool.
"This is a novel way to shape electric fields for moving ions around. It can improve MOMA, and it could improve commercial instruments," said INL engineer Tim McJunkin, who helped develop the new technology. "
Mass spectrometry allows scientists to determine a sample's chemical composition.
In some mass spectrometers, a sample - for instance, a few grains of Martian soil - is vaporized, often with a laser. The gas is then ionized, and the charged particles flow through an inlet, down a channel and into an ion trap.
The ions are then identified based on details of their movement, which depend on their mass and electrical charge.
To get ions to stream into the trap - rather than hit the channel walls and "die" - most current mass spectrometers rely heavily on airflow created by pumps.
However, this system is less than ideal for Mars missions; pumps are heavy, and they use a lot of energy.
TIC could assist spectrometers such as MOMA.
New TIC-based ion inlets greatly reduce the need for pumps, getting good ion flow solely by generating versatile, intricate electric fields.
Since ions are charged particles, properly constructed fields can guide ions safely to the trap all by themselves.
A few other ion inlet technologies attempt to do the same thing, but INL's invention boasts many advantages.
Firstly, TIC-based inlets should be cheaper and more robust than their competitors, because they're simpler to construct and have fewer parts.
They use only a single electrode, and they don't need any insulators.
They can be made from many different semi-conducting materials, such as graphite, glass, silicon or polymers.
And the fields TIC inlets can generate are not tied to their own shape, meaning they can be incorporated into a wider range of spectrometer designs.
Because of their simple construction, TIC-based inlets are also much smaller and lighter than other types, weighing less than an ounce.
This minuscule mass is a big plus for space missions, since it currently costs about 10,000 dollars to put one pound of payload into Earth orbit (and far more to get that payload to Mars).
INL's new invention can also be helpful in missions like ExoMars, which is only powered by solar energy.
It requires just 100 milliwatts of power - one thousand times less than a 100-watt light bulb.
And on top of these advantages, TIC delivers outstanding performance. (ANI)


Prof. Dr Umar Saif
Umar Saif received his academic training from LUMS, Cambridge and MIT. He received his PhD degree from University of Cambridge (2001) and Post doctorate from MIT (2002), in Computer Science. Dr Saif worked and taught at the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL) for four years, where he was part of the core team which developed system technologies for project Oxygen- a US$40 million project sponsored by the US Department of Defense and an industrial Alliance of world-class companies.
Dr Saif's research interests broadly span areas of Ubiquitous Computing, Operating Systems, Distributed Systems, Mobile Systems, Highspeed Routing Architectures and the impact of IT in developing world countries. Dr Saif has authored several technical publications and is a Fellow of the Cambridge Commonwealth Trust. He was the first Pakistani to receive a PhD in Computer Science from University of Cambridge. During his doctorate studies, he was a Trinity College Overseas Scholar and Commonwealth Scholar at University of Cambridge. He has been nominated for the MIT Technovator award and the TR100 award. He has served on the technical advisory board of several technology companies and is a regular speaker at technology forums, especially relating to the impact of IT in developing-world countries.
Disclaimer: This biography was up-to-date at the time of the speaker's last participation.


A multiscale method to analyze the deterioration due to alkali silica reaction considering the effects of temperature and relative humidity
Computational Methods for Coupled Problems in Science and Engineering V - A Conference Celebrating the 60th Birthday of Eugenio Onate, COUPLED PROBLEMS 2013
International Center for Numerical Methods in Engineering
1094 - 1100
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This work presents a three-dimensional multiscale framework to investigate the deterioration resulting from alkali silica reaction (ASR) in the concrete. In this contribution, 3D micro-CT scan of hardened cement paste (HCP) and aggregates with a random distribution embedded in a homogenized cement paste matrix represent the microscale and mesoscale of the concrete respectively. A 3D hydro-chemo-thermo-mechanical model based on staggered method is developed at the mesoscale of the concrete, yet taking into account the deterioration at the microscale due to ASR.
KeywordsAlkali silica reaction
Effects of temperature
Hardened cement paste
- Work in Progress 372
Showing items related by title, author, creator and subject.
Wu, T.; Temizer, I.; Wriggers, P. (2013)Computational thermal homogenization is applied to the microscale and mesoscale of concrete sequentially. Microscale homogenization is based on a 3D micro-CT scan of hardened cement paste (HCP). Mesoscale homogenization ...
A novel broadband multilevel fast multipole algorithm with incomplete-leaf tree structures for multiscale electromagnetic problems Takrimi, M.; Ergül, Ö.; Ertürk, V. B. (Institute of Electrical and Electronics Engineers Inc., 2016)An efficient and versatile broadband multilevel fast multipole algorithm (MLFMA), which is capable of handling large multiscale electromagnetic problems with a wide dynamic range of mesh sizes, is presented. By invoking a ...
Wu, T.; Temizer, I.; Wriggers, P. (Elsevier, 2014)Alkali-Silica Reaction (ASR) is a complex chemical process that affects concrete structures and so far various mechanisms to account for the reaction at the material level have already been proposed. The present work adopts ...