Citation: Alternative Renewable Bio-Fuel Sources: Camelina Sativa and Switchgrass (2008, September 15) retrieved 18 August 2019 from https://phys.org/news/2008-09-alternative-renewable-bio-fuel-sources-camelina.html Camelina and Switchgrass are making news in the bio-fuel industry. Camelina is a seed crop whose history goes back some 3500 years in Europe. Camelina is rich in Omega-3 fatty acids and is currently undergoing various stages of research and development as a bio-fuel in the Pacific Northwest. Switchgrass has been used for years in many Western states farmers for livestock forage or for use as deterrence for soil erosion. Camelina and Switchgrass have the advantage of being able to grow in arid conditions unsuitable for most food crops. It isn´t an exaggeration to say that both crops grow like weeds almost anywhere and under the most harsh weather conditions. This is particularly true of Camelina which seems to have a high tolerance for cold weather. According to the Department of Energy, Switchgrass has a distinct advantage due to its fast growing, low maintenance propensities and ability to absorb carbon dioxide as it grows. It has the ability to seek out water sources far beneath the soil surface and adds organic material to the soil as opposed to depleting it. Research is continuing in various labs including Auburn University to increase the yield and improve gasification technology. The goal is to create direct methods to produce alternative fuels like synthetic gasoline, diesel fuel, hydrogen and fertilizer, solvents and plastics. Additionally, Switchgrass is a suitable and stable feed crop. According to Dr. Stephen Guy of the University of Idaho, Moscow the study of Camelina is relatively new. The University of Idaho has various test plots and the process of establishing yield and oil levels is on-going. During the first three years of study, Camelina has shown great potential. The current year conditions were extremely poor for Camelina. However, the test plots were still able to produce 1200 pounds per acre.He states, ” Camelina generally produces 35-percent oil content and I use 30-percent extractable to produce about 80-gallons per acre of oil. When converted to bio-diesel (90-percent), the yield is about 72-gallons per acre for a 2000 pound an acre yield. Research to improve yield and growth rates are on-going at various universities in the Pacific Northwest. A European Union study entitled Camelina Oil As A Fuel For Diesel Transport Engines (doi:10.1016/S0926-6690(02)00098-5, 2003 Elsevier Science B.V.) demonstrated that Camelina seed oil produced a maximum power at the road wheels of 43.25kW and returned 12.57km/l compared to 38.50kW and 14.03km/l for mineral oil. At an engine speed of 2000 rpm and high loading, Camelina seed oil was found to produce 50-percent less CO2 and smoke opacity than mineral oil emissions.Testing is continuing along these lines in the United States. Another important aspect is the need to standardize all bio-fuel sources for use as gasoline or as an additive. Work in this area is currently underway. In June, 2008 Propel opened a Clean Fuel Point in downtown Seattle Washington. According to Green Car Congress, the Propel stations offers B5 and B20 diesel blends which include Camelina Sativa as well as other clean energy sources. The State of Montana is sponsoring a series of workshops on Bio-Diesel Production on January 28-29, 2009 with keynote speakers from the University of Idaho, Montana State University and the National Bio-Diesel Education Program. A list of various events and symposiums on the subject may be found at Green Car Congress. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Advancing biocrop alternatives in the Pacific Northwest Image: BozemanChronicle/Eitel INEOS Enterprises of the UK has entered into a partnership agreement with Great Plains-The Camelina Company for the purpose of expanding their bio-diesel enterprises world-wide. Great Plains-The Camelina Company is located in Montana and their achievements include establishing Camelina (oil seed) crushing machines and production facilities for creating bio-fuels. Switchgrass test plots at Auburn University have produced a five-year average of 11.5 tons of bio-mass equivalent to 1,150 gallons of ethanol per acre per year. Explore further
Viswanathan Anand is the current World Chess Champion. (PhysOrg.com) — In the recorded history of chess, world champions have always been male, not female. Further, there is currently only one woman in the top 100 chess players in the world. Because chess is often considered to be the ultimate intellectual activity, male dominance at chess is often cited as an example of innate male intellectual superiority. But rather than resort to biological or cultural explanations, a recent study proposes a different explanation. A team of researchers from the UK has shown that the under-representation of women at the top end in chess is almost exactly what would be expected, given the much greater number of men that participate in the game at all. Researchers Merim Bilalic, et al., have published their research on this statistical sampling explanation in a recent issue of the Proceedings of the Royal Society B.The authors analyzed the population of about 120,000 German players as recorded by the German chess federation in April 2007. Based on more than 3,000 tournaments per year, the German chess federation measures the skill level of all competitive and most hobby players in the country (the rating correlates highly with the widely known Elo rating). The sample population included 113,386 men and 7,013 women (a ratio of 16:1).First, the researchers estimated the expected performance of the top 100 male and top 100 female players. Then, they compared the expected differences in points between these high-ranking male and female players with the actual point differences. Theoretically, the size difference between the male and female groups should correspond to the point differences between the top performers in the two groups.The results showed that the top three women had more points than expected, the next 70 or so pairs showed a small advantage for the men, and the last 20 pairs showed a small advantage for the women. Overall, men performed slightly better than expected, with an average advantage of 353 points, whereas the expected advantage was 341 points. Nevertheless, about 96% of the actual difference between genders could be explained by the statistical fact that the extreme values from a large sample are likely to be larger than those from a small one.In the study, the scientists also discussed the question of why so few women participate in chess at all. While it’s possible that there exists a self-selection process based on innate biological differences that leads women to drop out of chess early on, this argument rests on a controversial assumption, the researchers say. That is, it requires that there is an innate difference between genders in the intellectual abilities associated with chess – an assumption that has little empirical evidence to support it.Whether or not statistical sampling covers all the bases of explaining male superiority in chess, the researchers hope that the explanation will be considered by both experts and laypeople. In previous discussions of gender difference, there is often no mention of participation rates, although a wide range of other reasons receive attention (e.g. different interests and gatekeeper effects, etc.). In addition, the researchers question whether a statistical sampling explanation might explain the predominance of men at the top of science and engineering fields – although performance in these activities is much more difficult to measure than in objectively ranked chess populations.More information: Bilalic, Merim; Smallbone, Kieran; McLeod, Peter; and Gobet, Fernand. “Why are (the best) women so good at chess? Participation rates and gender differences in intellectual domains.” Proceedings of the Royal Society B. doi: 10.1098/rspb.2008.1576.© 2009 PhysOrg.com Citation: Why Men Rank Higher than Women at Chess (It’s Not Biological) (2009, January 12) retrieved 18 August 2019 from https://phys.org/news/2009-01-men-higher-women-chess-biological.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Battery layers. Image: ReVolt In previous rechargeable zinc-air batteries the air electrolyte became deactivated and the reduction and oxidation reactions slowed or stopped after a few discharge/recharge cycles. The battery function could also be degraded if the water-based electrolyte dried out or was absorbed too deeply into the pores, and if the zinc deposited in the recharge cycles built up unevenly, which could cause short circuits. The new battery uses gelling and binding agents to control the zinc electrode shape, and controls the humidity inside the battery. The new catalysts used have been tested and found to improve both the reduction and production of oxygen during discharge/recharge cycles.Prototypes of the new battery have been tested for more than a hundred cycles, and are expected to last at least twice as long. CEO of ReVolt, James McDougall, said the company aims to increase the life to between 300 and 500 cycles, which would make them useful for cell phones and electric bicycles. Battery. Image: ReVolt The Swiss company ReVolt, from Staefa, plans to release the new batteries next year, initially as small batteries for use in hearing aids, and later for cell phones. Eventually much larger batteries are planned for electric vehicles.The new battery was developed in Trondheim in Norway by the SINTEF Group, the largest independent research institution in Scandinavia, and ReVolt was formed to market the device.Zinc-air batteries need oxygen from the air to generate the current. They are safer than lithium-ion batteries because they do not contain volatile materials, and therefore do not catch fire. Non-rechargeable zinc-air batteries have been available for some time, but rechargeable versions have proved more difficult to develop.The battery consists of an “air” electrode, an electrolyte, and a zinc electrode, all set in a casing that lets in air. When the battery is discharging the air electrode (with the help of catalysts) produces hydroxyl ions in the aqueous electrolyte. At the zinc electrode the hydroxyl ions oxidize the zinc, a process that releases electrons to form an electric current. During recharging the process is reversed, with oxygen being released at the air electrode. Explore further ReVolt has also been developing zinc-air batteries for use in electric vehicles. These batteries resemble fuel cells, with a zinc slurry forming a liquid zinc electrode, and a series of tubes forming the air electrode. Electricity is generated by pumping the slurry through the tubes, where it is oxidized and releases electrons. The resultant zinc oxide is stored in another compartment and flows back through the tubes when the battery is recharging. This releases oxygen, and the zinc oxide reverts to zinc. Since the slurry can be in greater volume than the air electrode, the energy density is increased and more electricity is produced. McDougall expects the batteries to last much longer too, for up to 10,000 discharge/recharge cycles. The battery could also be repaired, by replacing failed parts such as the air electrode. The zinc-air battery for hearing aids will be available next year. The battery for electric vehicles is still some years away from mass marketing.More information: www.revolttechnology.com/via Technology Review© 2009 PhysOrg.com (PhysOrg.com) — A new breed of rechargeable zinc-air batteries is soon to be available, and may replace lithium-ion batteries in cell phones, laptops and other consumer items. Lithium-ion batteries store only a third of the energy and cost around twice as much as the new batteries. Zinc-Air Batteries Will Extend Mission Times Of NASA Micro Aerial Vehicles Citation: New rechargeable zinc-air batteries coming soon (2009, October 29) retrieved 18 August 2019 from https://phys.org/news/2009-10-rechargeable-zinc-air-batteries.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Explore further There is also no evidence that indicates that this data is leaving your phone and being viewed by anyone. Pete Warden has built an application that will allow anyone with an iPhone or iPad, using iOS 4, to view the data being stored (see more information below). According to the Guardian, all your locations are logged to a file called “consolidated.db” and contain latitude and longitude coordinates along with a timestamp. The file can contain tens of thousands of data points since iOS 4’s release in June 2010. Pete Warden and Alasdair Allan, founder of Data Science Toolkit, discovered the file and presented their findings today to the Where 2.0 conference in San Francisco. Alasdair has also looked into Google’s Android phones for similar tracking code and could not find any. It’s not sure why Apple is collecting this data but it’s clearly intentional because the data is being restored across backups and phone migrations. Apple’s Product Security team was contacted but no one has responded. In the following video Pete Warden and Alasdair Allan discuss how the file was discovered and exam the data in the file. Germany warns of Apple security problem (PhysOrg.com) — Security researchers have discovered that any iPhone or iPad that has been updated with iOS 4 records everywhere you have been to a secret file. The file is also copied to the owner’s computer whenever the two are synchronized. Researchers have raised privacy fears with the latest discovery: any iPhone or iPad with iOS 4 can track your whereabouts by recording your latitude and longitude coordinates along with a timestamp. Apple was contacted but has not responded to any inquires. Map displays a visualization of iPhone data collection. Credit: O’Reilly radar. More information: Guardian, iPhone tracker Citation: iPhone and iPad with iOS 4 records your moves (w/video) (2011, April 20) retrieved 18 August 2019 from https://phys.org/news/2011-04-iphone-ipad-ios-wvideo.html © 2010 PhysOrg.com This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Explore further Many in the press have been suggesting that the saturation point for smartphones is fast approaching, causing companies that make them, to dig deeper in coming up with new ways to entice buyers. Now that variations in phone size and allowing for some customizations to cases have been exhausted, phone makers are looking to change the display. Samsung has been leading the charge with “bendable” displays—most noticeably those with its patented Youm technology that allows for curved displays.In this new effort, Samsung appears to be exploring the possibility of side screen edges that bend down, allowing images to be seen from different angles. Labels on the diagrams in the patent application indicate that side displays could be used for icons, as functions, navigation tools, indicators or even as a way to facilitate communication between devices. The bend angles appear to be set at the factory, thus users will not be able to adjust them.Samsung has indicated in the past that its ultimate goal is to make a smartphone that can be folded up and placed in a pocket—similar to a wallet or billfold. To achieve that goal, engineers must overcome several hurdles. One of those is how to make a phone strong enough to survive being sat on, dropped, etc. while also being tough enough to withstand scratching or outright breaking. Other issues are how to make a bendable type of plastic screen that doesn’t grow foggy, or break apart after repeated bends.For its part, Samsung hasn’t made any announcements about the new side bending technology, but others in the press, citing knowledgeable insider information claim that such a phone could be on the market as early as next year. If so, that should help the company keep ahead of Apple—that company is reportedly also working on a bendable screen—one with sensors that can gauge how hard a person is pressing and allow phone apps to respond accordingly. World’s first curved smartphone hits South Korea market (Update) © 2013 Phys.org Citation: Samsung applies for patent on wraparound phone display (2013, November 18) retrieved 18 August 2019 from https://phys.org/news/2013-11-samsung-patent-wraparound.html (Phys.org) —Samsung has applied for a US patent on a new type of wraparound display for a smartphone. According to diagrams in the patent, the wraparound would be more like single bends on either side of the main screen that take up part of the side of the phone. The result is a beveled look, where the bevel can display images and respond to touches just like the main screen. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen (Phys.org)—A team of researchers with Princeton University has found that marmosets appear to learn at least some of their vocalizations from their parents. In their paper published in the journal Science, the group describes a study they carried out with the little South American monkeys and what they learned from it. David Margoliash with the University of Chicago and Ofer Tchernichovski with City University of New York offer some insight into the work done by the team in a Perspectives piece in the same journal edition. Explore further Citation: New evidence suggests marmosets learn vocalizations from parents (2015, August 14) retrieved 18 August 2019 from https://phys.org/news/2015-08-evidence-marmosets-vocalizations-parents.html Play A sound movie of how infant marmoset calls elicit vocal responses from marmoset parents. The developing infant can use this type of contingent response to learn from adult vocal responses. Credit: Daniel Y. Takahashi & Asif A. Ghazanfar The researchers also recorded the size and weight of the marmosets as they grew and measured their respiratory abilities—doing so allowed them to see that the changes in the vocalizations that occurred over time were not likely the result of simple physical maturation. There has been a belief in modern science that only humans and songbirds can learn to make new sounds that have some sort of meaning, by listening to others. That may not be the case after all as the team at Princeton has carried out a study that appears to show infant marmosets learning to vocalize in an adult fashion, by mimicking the calls of adults.The study consisted of separating captive infants from their parents for short periods of time during the first two months of the infant’s life (the time it takes for a marmoset to learn to talk like an adult) and recording the vocalizations that occurred as the infants and parents continued to chatter back and forth. In studying the recordings, the researchers were able to watch as clusters of noises from the young monkeys congregated, suggesting they were learning that certain noises held certain meaning. The researchers also recorded noises made by young and old individuals under normal circumstances and when they were kept completely isolated for short periods of time. © 2015 Phys.org Play Vocalizations of an infant marmoset on postnatal day 1. Credit: Daniel Y. Takahashi & Asif A. Ghazanfar In studying their recordings, the researchers discovered that young marmosets that had a high frequency of back and forth chatter with adults came to vocalize like an adult at a younger age than did other young monkeys that had less communication with adults. Taken together, the data suggests, the researchers claim, that marmosets learn to talk like an adult, by listening and mimicking adults. Journal information: Science Play A sound movie of adult marmosets exchanging vocalizations. Credit: Daniel Y. Takahashi & Asif A. Ghazanfar Marmosets found to learn to take turns when vocalizing PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen Common marmoset. (Callithrix jacchus) Credit: Carmem A. Busko/Wikipedia/CC BY 2.5 This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
The 3-D-printed hollow polymer tubes or struts that form the building blocks of lattices were filled with magnetorheological (MR) fluid suspensions. The scientists used the LAPµSL system for custom layer-by-layer 3-D printing by projecting UV light patterns onto a photocurable resin to construct 3-D structures from a stack of 2-D images. For consistency, they replicated a previously established protocol on microstereolithography. The MR fluids contained ferromagnetic microparticles in nonmagnetic liquids that could rapidly change viscosity in response to an applied magnetic field. In the absence of a magnetic field, the MR fluid was liquid-like in behavior, with randomly distributed particles that flowed freely to form a pool on a planar substrate. When a magnetic field was applied, the particles aligned into chains along the field lines and formed a spicular array of blade-like structures that resembled stalactite deposits. The fluid viscosity monotonically increased to reach a saturation plateau at a magnetic field strength of ~ 0.3 T. Explore further The term 4-D represents 3-D printed materials that can change shape or function in response to external conditions or stimuli, including mechanical force, swelling and magnetic fields. The existing demonstrations, however, lack deterministic control of mechanical properties or exhibit slow kinetics for the intended chemical transformations. In the present study, Jackson et al., reveal a new class of field-responsive mechanical metamaterials (FRMM) that are 3-D printed to exhibit programmable, predictive, reversible and controlled mechanical properties in rapid response to a remote magnetic field. Video of a cuboctahedron lattice with a 10-g mass placed on its top surface and the magnetic field strength gradually lowered by slowly removing a magnet. Credit: Science Advances, doi: 10.1126/sciadv.aau6419 Journal information: Nature Materials Single strut characterization. (A and B) Schematic illustrations of how the magnetic field application direction affects the stiffening of a strut. (A) In the axial case, a magnetic field applied transverse to the strut will produce no increase in axial stiffness, regardless of field strength applied. (B) In the bending case, a magnetic field applied perpendicular to the displacement will have no effect on bending stiffness, regardless of the field strength applied. (C) Side view optical image of the hollow polymer strut before filling in with MR fluid. Inset is a scanning electron microscopy micrograph of the hollow polymer strut cross section. (D) Side view optical image after infilling with MR fluid. The strut dimensions are 1.0-mm inner diameter (ID), 1.1-mm outer diameter (OD), 50-μm wall thickness, and 5-mm length (L). (E and F) Force-displacement slope versus magnetic field strength plots. (E) Uniaxial compression showing experimental results and model calibration. Inset is a schematic illustration of the experimental setup from the side view. (F) Cantilevered bending showing experimental results and model calibration. Inset is a schematic illustration of the experimental setup from the side and cross-sectional views. The table indicates a summary of the calibrated material constants. Credit: Science Advances, doi: 10.1126/sciadv.aau6419. To observe the field response effect of the mechanical metamaterial lattice, the scientists placed a static load of 10 g mass, with an initial condition of 0.11 T maximum applied magnetic field. When the magnetic field was slowly removed, the effective stiffness decreased, deforming the lattice under the load to compress and bend. Upon complete removal of the magnet, the mass slid off the lattice surface to show the changed load-carrying ability. The FRMMs can change stiffness in a stress-controlled experiment, by solely adjusting the magnetic field. The work demonstrated the first tunable FRMMs with a dynamic range of rapid and reversible mechanical reactions in response to remotely applied magnetic fields. The development process is agile and simple for replication, based on 3-D printing, combined with controlled fluid delivery methods to engineer a new class of microarchitectural mechanical metamaterials. Future FRMMs can be composed of active microfluidic networks to regulate the flow of MR fluids in micro-compartments for time-controlled accessibility. Magnetic shaping can increase directional control for a variety of applications. The scientists envision the use of FRMMs in a broad range of emerging applications including soft robotics, as rapidly adaptive “crash-resistant” helmets for cyclists and as noise-cancelling smart wearables. More information: Julie A. Jackson et al. Field responsive mechanical metamaterials, Science Advances (2018). DOI: 10.1126/sciadv.aau6419Ulrike G. K. Wegst et al. Bioinspired structural materials, Nature Materials (2014). DOI: 10.1038/nmat4089 Qi Ge et al. Multimaterial 4-D Printing with Tailorable Shape Memory Polymers, Scientific Reports (2016). DOI: 10.1038/srep31110 A. Sydney Gladman et al. Biomimetic 4-D printing, Nature Materials (2016). DOI: 10.1038/nmat4544 Structure and rheological tests of MR fluid in response to applied magnetic fields. (A) Optical image of the MR fluid forming a liquid pool on a planar substrate in the absence of a magnetic field. (B) Optical image of the MR fluid forming ordered, blade-like columns in the presence of a magnetic field. (C) Rheological plot of the MR fluid’s relative steady-state viscosity, which increases with increasing applied magnetic field strength. The field off steady-state viscosity is 140 cP. (D) Rheological plot demonstrating the response time of the MR fluid at various magnetic field strengths. Credit: Science Advances, doi: 10.1126/sciadv.aau6419 3-D printed active metamaterials for sound and vibration control 3D printing and MR fluid infilling of unit cells. (A) Schematic illustration of the LAPμSL 3D printing process used to build struts, unit cells, and lattices. (B) Optical image of a resin-filled polymer cuboctahedron unit cell. (C) Optical image of drained (hollow) unit cells affixed with a dissolvable wax to syringe nozzles for infilling. (D) Optical images from a time-lapse recording of the MR fluid filling in process. (E to G) Optical image of the unit cell with inlet (green) and outlet (red) ports separated by various strut lengths. (E) Ports separated by one strut. (F) Ports separated by two struts. (G) Ports separated by three struts with the highest degree of infilling. Credit: Science Advances, doi: 10.1126/sciadv.aau6419 , Science Advances The scientists showed the feasibility of the fabrication and mechanical testing approach for more complex architectures by 3-D printing cuboctahedron unit cells using the LAPµSL process. The unit cells were removed of any prepolymer liquid resin and injected with the MR fluid. The filling in (or infilling) procedure was successful when the structure was oriented to prevent entrapped gas bubbles.Jackson et al. tested the cuboctahedron unit cells in a custom apparatus by varying the distance of the magnet to the unit cell structure to control the magnetic field strength. They calculated the relationship between the effective Young’s modulus and the magnetic field strength of the unit cell through compression tests. The response time was measured by the rate at which mechanical properties changed in the material in response to the application or removal of a magnetic field. The reversibility of the magneto-mechanical results was also tested with a strain-controlled measurement, where the cell cycled between field on/off states while under 10 percent compressive strain. The magnetic particles transitioned faster from a state of disorder to order when the magnetic field was applied.The scientists showed the possibility of creating a larger area FRMM by printing a cuboctahedron lattice with 2 by 2 by 2 arrangement of unit cells. To produce the specimens, the drained hollow lattices were injected with MR fluid as before, but in this instance with two syringes attached to each unit cell. Once again, the stiffness response of the lattice was measured as a function of the magnetic field strength. Citation: Field-responsive mechanical metamaterials (FRMMs) (2018, December 11) retrieved 18 August 2019 from https://phys.org/news/2018-12-field-responsive-mechanical-metamaterials-frmms.html In the study, magneto-mechanical tests were conducted with compression and cantilever bending. Each cylinder (strut) was filled with commercially available MR fluid, which comprised of 50 percent carbonyl iron particles (ranging from 4 to 20 µm) in a hydrocarbon particle stabilizer oil. Each magneto-mechanical test was repeated at several magnetic field strengths, where the field was aligned in parallel to the direction of applied force to obtain a series of force-displacement curves. Among the diverse orientations, the effective stiffness was largest when the field applied was parallel to the direction of the force. The tests were used to calibrate the model at the level of a single strut and ultimately predict the field response of a bigger lattice architecture.The scientists used a standard composite beam theory, where the analysis assumed the Euler-Bernoulli bending theory to derive a model of the strut. The theory included the effective elastic stiffness of the MR-fluid and elastic stiffness of the struts (Young’s modulus). The analytical model assumed a linear relationship between the mechanical strength and increase in the magnetic field. The experiments were kept below the threshold value of 0.3 T since the MR fluid was previously observed to saturate at this value. Magneto-mechanical characterization of cuboctahedron unit cells. (A) Schematic illustration of the experimental setup for mechanical testing of MR fluid–filled samples with magnetic field strength controlled by translating a permanent magnet close to or away from the sample while measuring mechanical properties. (B) Plot of effective stiffness versus magnetic field strength for the cuboctahedron unit cell showing a 62% increase in stiffness from 0 to 0.18 T. Inset is an optical image of the MR fluid–filled unit cell. (C) Load versus time plot for one example of cycling a unit cell between field off (0.0 T) and field on (0.10 T) states to measure response times. (D) Schematic illustration of how the particles switch from ordered to disordered structures within the MR fluid–filled struts of the unit cells during field application or removal. Credit: Science Advances, doi: 10.1126/sciadv.aau6419 , Scientific Reports In a recent study published in Science Advances, materials scientists Julie A. Jackson and colleagues presented a new class of materials architecture called field-responsive mechanical metamaterials (FRMM). The FRMMs exhibit dynamic control and on-the-fly tunability for designing and selecting the construct’s composition and structure. Typically, properties of mechanical metamaterials are programmed and set when the architecture is designed and constructed, without changing in response to shifting external environmental conditions or applications thereafter. The diverse characteristics of FRMMs were first demonstrated by printing complex structures of polymeric tubes filled in with magnetorheological (MR) fluid suspensions to allow remote magnetic fields to control the materials. Accordingly, the scientists observed rapid, reversible and sizable changes of the effective stiffness in the new metamaterial constructs. © 2018 Science X Network Synthetic materials often mimic cellular structures such as teeth, bone and bird beaks in nature to replicate their excellent strength and toughness relative to density. Advanced materials are bioengineered to mimic stochastic (random) cellular structures in the form of polymers and metal foams for structural and functional applications. Nature can also create periodic architectures by evolutionary design, where ordered cellular structures outperform the stochastic counterparts as seen with defensive armor shells and dactyl clubs in crustacea. In the lab, additive manufacturing techniques and 3-D printing are used to engineer cellular structures with nano-, micro-, meso- and macro-scale features that exhibit unique combinations of mechanical, functional and thermal properties. Often referred to as metamaterials, the structures have demonstrated innovative characteristics, including:Lightweight, yet stiff and strong architecture in 3-D ceramic nanolatticesHigh mechanical resilience in graphene periodic 3-D aerogel microlattices.Negative Poisson’s ratio in origami-based metamaterials. Elasto-mechanical “unfeelability” cloaks and invisibility cloaks Multimaterial layouts with negative coefficients of thermal expansion.These materials combine two or more contrasting features for unique properties, but their architecture remains fixed in time after fabrication. As a result, the materials cannot respond and adapt to changing external conditions. Adaptable and responsive materials are increasingly engineered via 4-D printing, in which the fourth dimension represents time, presently emerging as a new research area in materials science. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
SOPA Images YouTube Channels Suspended For ‘Coordinated’… by NPR News Scott Neuman 8.23.19 3:46am Google has suspended 210 YouTube channels it says were being used as part of a “coordinated” campaign to influence public opinion about the pro-democracy protests in Hong Kong.The move follows Twitter’s suspension earlier this week of nearly 1,000 accounts for violating the company’s “platform manipulation policies” it said were tied to Chinese state actors trying to undermine the Hong Kong protests. Facebook said it was also taking down several pages and accounts for “coordinated inauthentic behavior as part of a small network that originated in China and focused on Hong Kong.”In a statement, Google, which owns YouTube and whose parent company is Alphabet Inc., said its decision to suspend the channels was “to combat coordinated influence operations,” but it stopped short of directly blaming the Chinese government.It said the channels “behaved in a coordinated manner while uploading videos related to the ongoing protests in Hong Kong,” adding that their discovery “was consistent with recent observations and actions related to China announced by Facebook and Twitter.””We found use of VPNs and other methods to disguise the origin of these accounts and other activity commonly associated with coordinated influence operations,” the statement said.Google is a financial supporter of NPR.The student-led protests in Hong Kong have been going on for nearly 11 weeks. They started out with calls for the government to kill a controversial bill that would have allowed some accused of crimes in Hong Kong to be sent to mainland China for trial. Since then, the protesters have added old and new grievances, including calls for the direct election of Hong Kong’s chief executive and an independent investigation of alleged police brutality in dealing with the demonstrators.Meanwhile, Beijing has weighed in, warning protesters that they are “playing with fire” and making it known that China would respond with force if necessary. Chinese state media has broadcast video of armored personnel carriers participating in drills conducted by the Chinese People’s Armed Police in the neighboring city of Shenzhen.China’s Foreign Ministry’s spokesman Geng Shuang, responding on Tuesday to the reports that Twitter and Facebook had suspended accounts over the alleged influence campaign, said he believed “people around the world will come to their own judgement about what happens in Hong Kong and what is the truth.”The news from Google comes as a bipartisan group of lawmakers on Capitol Hill warns that China is using social media platforms to manipulate public opinion over Hong Kong, according to The Hill.Praising Facebook and Twitter for their quick action, California Democrat Rep. Adam Schiff, the chairman of the House Intelligence Committee, told the newspaper, “We know from experience that social media platforms can be powerful engines for spreading false information online with real world consequences.”Copyright 2019 NPR. To see more, visit NPR.
As a tribute to the Indian soldiers to participated in the First world war, IGNCA(Indira Gandhi National Centre for Arts),Rooli Books and Embassy of France have organised an exhibition titled India and the First World War. The exhibition is on since January 13 and will continue till February 10 at Twin Art Gallery, IGNCA.This exhibition was inaugurated by Ravindra Singh and Francois Richier (Ambassador of France) in India to shed light on the bravery of those men who fought in alien territories. Subedar Yogendra Singh Yadav presided as the guest of honour at the event. Also Read – ‘Playing Jojo was emotionally exhausting’At the inauguration Dipali Khanna, Member Secretary, IGNCA said “It’s been a hundred years since the great war happened, in which the millions of Indian people participated and lost their lives. Pramod kapoor founder of Rooli Books first came with the idea about an year ago that the memories of Indian soldiers which have been left abroad should be brought home to the Indian public. He also said that the Indian soldiers of World War 1 have not been given the respect which they deserved, and this is the right time to give them their due.” Also Read – Leslie doing new comedy special with NetflixPramod Kapoor also described his experience on curating this exhibition. He said this is the small tribute to seven lakh Indian soldiers and how the 7400 Indian men led their lives over the four years of the war. Subedar Yogendra Singh Yadav said that this exhibition reminded him of old days. The gallery is displaying more than 60 objects and 100 photographs of India’s contribution in the First World War for the first time. 100 years old uniforms, items of personal use by the Indian troops and letters written by the soldiers during the war. The photographs at the exhibition capture some untold stories of the Indians such as Sikh soldiers carry Guru Granth Sahib on their head, in a foreign land where they had no Gurudwaras. The source of the images in the exhibition are Imperial War Museum, British Library London, French Military Archives and Flendersy Museum Belgium.The objects were sourced from just one person Dominique Faivre, who had been collecting these objects of the Indian Soldiers from past thirty forty years. The exhibition also has sound recordings and silent movies of the Indian soldiers made between 1914-1918 for the viewers. It is also been held to tell the youth and children about the sacrifices and bravery of Indian soldiers. Rooli Books have also published books which are related to Indian army.
Titled Architecture of the Buddhist World: Southeast Asia, the exhibition hosted by India International Centre is a study of architecture shaped by philosophy and practice of Buddhism in Southeast Asia. It presents a comprehensive survey of the diversity and complexity of architectural models and drawings with