Domain: doi.org
Stories and comments across the archive that link to doi.org.
Stories · 135
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Kindergarteners Today Get Little Time To Play, and It's Stunting Their Development (qz.com)
Christopher Brown Associate professor, University of Texas at Austin, writes:Researchers have demonstrated that five-year-olds are spending more time engaged in teacher-led academic learning activities than play-based learning opportunities that facilitate child-initiated investigations and foster social development among peers.During his research and investigation, Brown found that a typical kindergarten classroom sees kids and one teacher with them almost the entire school day. During this period, they engage in about 15 different academic activities, which include "decoding word drills, practicing sight words, reading to themselves and then to a buddy, counting up to 100 by ones, fives and tens, practicing simple addition, counting money, completing science activities about living things, and writing in journals on multiple occasions." Recess did not occur until the last hour of the day, and only lasted for about 15 minutes. He adds:For children between the ages of five and six, this is a tremendous amount of work. Teachers too are under pressure to cover the material. When I asked the teacher, who I interviewed for the short film, why she covered so much material in a few hours, she stated, "There's pressure on me and the kids to perform at a higher level academically." So even though the teacher admitted that the workload on kindergartners was an awful lot, she also said she was unable to do anything about changing it. -
When We're Happy, We Actively Sabotage Our Good Moods With Grim Tasks (arstechnica.com)
Beth Mole, writing for Ars Technica: Always keeping your house tidy and spotless may earn you the label of "neat freak" -- but "super happy" may be a more accurate tag. When people voluntarily take on unpleasant tasks such as housework, they tend to be in particularly happy states, according to a new study on hedonism. The finding challenges an old prediction by some researchers that humans can be constant pleasure-seekers. Instead, the new study suggests we might seek out fun, uplifting activities mainly when we're in bad or down moods. But when we're on the up, we're more likely to go for the dull and dreary assignments. This finding of "flexible hedonism," reported this week in The Proceedings of the National Academy of Sciences, may seem counterintuitive because it suggests we sabotage our own high spirits. But it hints at the idea that humans tend to make sensible short-term trade-offs on happiness for long-term gains. "Although our data cannot directly tell us whether regularly engaging in unpleasant activities predicts psychological and social adjustment five or 10 years down the line, a large body of work has consistently demonstrated the importance of sleeping, employment, and living in a reasonably clean and organized home on mental and physical health," according to the study authors, led by Maxime Taquet of Harvard and Jordi Quoidbach of the University Pompeu Fabra in Spain. -
Does More Carbon Dioxide Mean Increased Crop Water Productivity? (arstechnica.com)
An anonymous reader points us to an Ars Technica report: For the most part, we think of rising levels of carbon dioxide as an environmental problem. But atmospheric CO2 can also boost agricultural productivity by helping plants grow. How do these potential issues balance out? In an investigation recently published in Nature Climate Change, scientists have looked into the global implications of carbon dioxide's ability to enhance agricultural productivity. Increased levels of CO2 can enhance photosynthesis and reduce leaf-level transpiration, the process by which some of the water that plants draw from the ground gets released back into the atmosphere. These changes can reduce growing seasons and water loss. The result could be an increase in what's called "crop water productivity," i.e. the amount of food produced for each unit of water expended. If elevated CO2 levels increase crop yield and reduce water consumption at large scales, this could help ensure water and food security despite the climate disruptions. By combining data from a massive network of field experiments and global crop models, the scientists claimed that depending on the crop type, global crop water productivity will increase by 10 to 27 percent by the 2080s. Arid regions exhibited large increases that were based on crop type. -
Simple Method Yields A Wrinkly, Durable, Water-Repellent Coating (acs.org)
ckwu writes: Superhydrophobic coatings that make water droplets dance and roll off of a surface show promise for applications such as self-cleaning cars, buildings, and food processing equipment. A new method creates a durable superhydrophobic coating by combining two common materials -- Teflon and a shrinkable plastic -- in a few simple steps. The researchers took inspiration from work done with the polystyrene material found in Shrinky Dinks -- the children's crafting kit. They deposited Teflon onto a similar material called PolyShrink, heated it, and found that the Teflon formed a crinkled surface that caused water to bead and roll off easily. The best results came from polyolefin shrink wrap coated with a 10nm-thick layer of Teflon. What's more, the surface is durable, having about the same scratch resistance as an aluminum coating, and repels water even after being scratched. Update: 03/09 16:10 GMT by T : Note: That's nm, rather than mm; now fixed. -
Fungi From Guts Of Herbivores Could Help Us Make Biofuel (dispatchtribunal.com)
hypnosec writes: Researchers have revealed through a new study that fungi from the gut of herbivores like goats, horses and sheep could be used to make biofuel. According to researchers at University of California, Santa Barbara, the fungi retrieved from these animals are capable of converting plant material into sugars that can be easily used to make biofuel and other products at the same efficiency as the best fungi engineering in the industry. Michelle O'Malley, lead author of the paper and professor of chemical engineering at the University, explains that these fungi naturally have the best possible set of enzymes for the job of breaking down biomass and as per their findings, these enzymes work together to break down stubborn plant material. -
Let Your Pupils Do the Typing
New submitter s.mathot writes: Researchers from France and the Netherlands have developed a way to—literally—write text by thinking of letters. (Academic paper [open access], non-technical blog, YouTube video.) This technique relies on small changes in pupil size that occur when you covertly (from the corner of your eye; without moving your eyes or body) attend to bright or dark objects. By presenting a virtual keyboard on which the 'keys' alternate in brightness, and simultaneously measuring the size of the eye's pupil, the technique automatically determines which letter you want to write; as a result, you can write letters by merely attending to them, without moving any part of your body, including the eyes. -
Carbon Nanotube Films Stronger Than Kevlar (acs.org)
ckwu writes: Carbon nanotubes are exceptionally strong and stretchy. But so far, films made out of them have come nowhere close to having the mechanical strength of individual nanotubes. Researchers now report a simple fabrication method to make carbon nanotube films that are five times as strong as those made before—and stronger than films made from Kevlar or carbon fiber. The films had an average tensile strength of 9.6 gigapascals. By comparison, Kevlar fibers and commercially used carbon fibers are around 3.7 and 7 GPa, respectively. The films are also four times as pliable as conventional carbon fibers, able to elongate 8% on average. -
Study Finds Humans Are Worse Than Radiation For Chernobyl Animals
derekmead writes: A study published today in Current Biology shows that wildlife in the Chernobyl exclusion zone is actually more abundant than it was before the disaster. According to the authors, led by Portsmouth University professor of environmental science Jim Smith, the recovery is due to the removal of the single biggest pressure on wildlife—humans. "The wildlife at Chernobyl is very likely better than it was before the accident, not because radiation is good for animals, but because human occupation is much worse,” Portsmouth University professor of environmental science Jim Smith says. “We were trying to emphasize that this study is a remarkable illustration of an obvious, but important message,” he said. “It is ordinary human habitation and use (farming, forestry, hunting) of land which does most ecological damage.” -
Foam-Eating Worms May Offer Solution To Mounting Waste
ckwu writes: Polystyrene foams—including products like Styrofoam—are rarely recycled, and the materials biodegrade so slowly that they can sit in a landfill for hundreds of years. But a pair of new studies shows that mealworms will dine on polystyrene foam when they can't get a better meal, converting almost half of what they eat into carbon dioxide. In one study, the researchers fed mealworms polystyrene foam and found that the critters converted about 48% of the carbon they ate into carbon dioxide and excreted 49% in their feces. In the second study, the researchers showed that bacteria in the mealworms' guts were responsible for breaking down the polystyrene--suggesting that engineering bacteria might be a strategy for boosting the reported biodegradation. -
Foam-Eating Worms May Offer Solution To Mounting Waste
ckwu writes: Polystyrene foams—including products like Styrofoam—are rarely recycled, and the materials biodegrade so slowly that they can sit in a landfill for hundreds of years. But a pair of new studies shows that mealworms will dine on polystyrene foam when they can't get a better meal, converting almost half of what they eat into carbon dioxide. In one study, the researchers fed mealworms polystyrene foam and found that the critters converted about 48% of the carbon they ate into carbon dioxide and excreted 49% in their feces. In the second study, the researchers showed that bacteria in the mealworms' guts were responsible for breaking down the polystyrene--suggesting that engineering bacteria might be a strategy for boosting the reported biodegradation. -
The New Technique That Finds All Known Human Viruses In Your Blood
schwit1 writes with this story at the Atlantic that profiles Ian Lipkin and his new method for quickly detecting all known human viruses in a sample: Ian Lipkin, a virus hunter from Columbia University, recently received a blood sample from colleagues at the National Institutes of Health. They came from a man who had received a bone-marrow transplant and had fallen mysteriously ill, with evidence of severely inflamed blood vessels. In analyzing a similar case a few years back, Lipkin had discovered a new polyomavirus, part of a family that can cause disease in people with compromised immune systems. Perhaps this new case would yield another new virus. It didn't. Instead, when Lipkin's team ran the sample through a system that they had devised to detect human viruses, they found that the man was infected with dengue virus. In hindsight, that made sense-he had recently returned from Vietnam, where dengue is prevalent. But the thing is: The team wasn't looking for dengue virus.
"It wasn't what we anticipated, but we didn't have to make a priori decisions about what we planned to find," Lipkin says. "When people analyze samples from people who are ill, they have some idea in mind. This is probably an enterovirus, or maybe it's a herpesvirues. They then do a specific assay for that particular agent. They don't usually have the capacity to look broadly." The new system, known as VirCapSeq-VERT, barrels past this limitation. Lipkin, together with fellow Columbia professors Thomas Briese and Amit Kapoor, designed it to detect all known human viruses, quickly, efficiently, and sensitively. By searching for thousands, perhaps millions, of viruses at once, it should take a lot of the (educated) guesswork out of viral diagnosis. -
Easy-To-Clean Membrane Separates Oil From Water
ckwu writes: A steel mesh with a novel self-cleaning coating can separate oil and water, easily lifting oil from an oil-water mixture and leaving the water behind. Unlike existing oil-water separation membranes, if the coated mesh gets contaminated with oil, it can be simply rinsed off with water and reused, without needing to be cleaned with detergents. The team was able to use the mesh to lift crude oil from a crude oil-seawater mixture, showcasing the feasibility of oil-spill cleanup. The membrane could also be used to treat oily wastewater and as a protective barrier in industrial sewer outlets to avoid oil discharge. -
Printing Flexible Lithium-Ion Batteries
ckwu writes: The designs of pacemakers, watches, and other wearable gadgets have to be tailored around existing battery shapes, such as cylinders, coin cells, and rectangles. But a team of researchers hopes their fully printable, flexible lithium-ion batteries will one day free designers from these constraints. Battery shapes are now limited because of the need to contain liquid electrolytes. Two years ago, the researchers designed a printable, solid-state electrolyte composed of alumina nanoparticles and lithium combined with polymer that can be cured by ultraviolet light. In this latest work, they used a stencil printing technique to print full battery cells with the electrolyte and other printable materials for the electrodes. They printed batteries on paper and the curved surface of a glass mug. These printed Li-ion batteries can power small LEDs but still need a lot of improvements because they don't last long before needing recharging. -
Printing Flexible Lithium-Ion Batteries
ckwu writes: The designs of pacemakers, watches, and other wearable gadgets have to be tailored around existing battery shapes, such as cylinders, coin cells, and rectangles. But a team of researchers hopes their fully printable, flexible lithium-ion batteries will one day free designers from these constraints. Battery shapes are now limited because of the need to contain liquid electrolytes. Two years ago, the researchers designed a printable, solid-state electrolyte composed of alumina nanoparticles and lithium combined with polymer that can be cured by ultraviolet light. In this latest work, they used a stencil printing technique to print full battery cells with the electrolyte and other printable materials for the electrodes. They printed batteries on paper and the curved surface of a glass mug. These printed Li-ion batteries can power small LEDs but still need a lot of improvements because they don't last long before needing recharging. -
Transparent Paper Produces Power With Just a Touch
ckwu writes: A new transparent-paper device can generate electrical power from a user's touch. The paper energy-harvester could be used to make disposable, self-powered touch screens that fold; interactive light-up books; touch-sensitive skin for prosthetics; and security systems for art and documents, according to the researchers. The device is made out of nanopaper, a tangled mat made of nanometers-wide cellulose fibers that is transparent and smooth like plastic. The researchers deposit carbon nanotubes on the nanopaper to make a pair of electrodes, and then sandwich a polyethylene film in between. The generator works via electrostatic induction. Pressing one side of the device causes a change in the charge balance between the nanotube electrodes, resulting in a flow of current through the device. Releasing the pressure causes electrons to flow back, so repeated pressing and releasing creates continuous current. The researchers demonstrated that the generator could produce enough power when pressed to light up a small liquid-crystal display. -
Nanoparticle-based Fibers Could Lead To No-fade Textiles With Structural Color
JMarshall writes: Researchers have created fibers with structural color properties, no dyes needed. The researchers electrospun fiber mats from a solution of latex nanoparticles, creating fibers made of uniformly packed nanospheres. The resulting mats have structural color properties that depend on the size of the nanoparticles used. By using capillaries as molds, they obtained more uniformly packed spheres with even purer colors. The downside: the fibers so far are too weak to be useful. One solution could be to print the particles like ink on existing fibers. -
Metamaterial Forms Near-Perfect Mirror
New submitter JMarshall writes: Researchers have made near-perfect reflectors out of a silicon metamaterial. These reflectors could offer a simpler, less expensive way to make high-performance mirrors for lasers or telescopes. Metamaterials typically use nanoscale patterning to create unusual properties not present in the bulk material. In this new method, researchers used off-the-shelf, nanosized polystyrene beads and allowed them to self-assemble into a monolayer with a hexagonal pattern. Using the monolayer as a photolithographic mask, the researchers etched an array of silicon cylinders, each a few hundred nanometers across, onto a wafer. The cylinders act like tiny resonators for a particular light frequency—analogous to the way a given sound frequency will make a tuning fork hum. The array reflected 99.7 % of incident light at their peak wavelength. These simple metamaterial mirrors might one day replace current high-performance reflectors, which are somewhat costly to make. -
First Ultraviolet Quantum Dots Shine In an LED
ckwu with word that South Korean researchers have created the first UV-emitting quantum dots, and employed them in the creation of a flexible LED. Their achievement is notable because no one has previously succeeded in making quantum dots capable of emitting light at wavelengths shorter than 400 nm, which defines the upper range of the UV spectrum. Writes ckwu: To get quantum dots that emit UV, the researchers figured out how make them with light-emitting cores smaller than 3 nm in diameter. They did it by coating a light-emitting cadmium zinc selenide nanoparticle with a zinc sulfide shell, which caused the core to shrink to 2.5 nm. The quantum dots give off true UV light, at 377 nm. An LED made with the quantum dots could illuminate the anticounterfeiting marks on a paper bill. The article names a few applications of the technology, besides, including water sterilization and industrial applications. -
Soft Sensors Map Skin Mechanics
MTorrice writes: An international research team has built electronic, flexible patches that can measure the mechanical properties of skin and other biological tissue. The sensors consist of nanoribbons of a piezoelectric material, lead zirconate titanate, which deforms when jolted with electrical energy and, conversely, produces electricity when it's deformed. The researchers mapped the skin elasticity of dozens of patients in the clinic, building up quantitative data on healthy and damaged tissue. The information could help doctors better assess conditions such as dermatitis and skin cancer. The team believes that similar sensors could be implanted inside the body to monitor blood vessels and other soft tissue for damage or dysfunction. -
Virtual Reality Games Can Improve Memory Retention of Safety Instructions
vrml writes: Using a virtual reality (VR) headset to experience risky situations as immersive 3D games improves memory retention of passenger safety instructions, according to research published in the IEEE Transactions on Visualization and Computer Graphics, and illustrated by a YouTube video. Researchers recruited occasional flyers: half of them played a VR gaming experience of an airliner water landing and evacuation, while the other half studied a real airline safety card. After one week, passengers who had studied the safety card suffered a significant loss of knowledge, while passengers who had played the VR game fully retained the safety knowledge gained. The research group has now made available its emergency water landing experience also for the Oculus Rift. -
Internet of Things Endangered By Inaccurate Network Time, Says NIST
An anonymous reader writes: Current standards of network timekeeping are inadequate to some of the critical systems that are being envisaged for the Internet of Things, according to a report (PDF) by the National Institute of Standards and Technology (NIST). The report says, "A new economy built on the massive growth of endpoints on the internet will require precise and verifiable timing in ways that current systems do not support. Applications, computers, and communications systems have been developed with modules and layers that optimize data processing but degrade accurate timing." NIST's Chad Boutin likens current network accuracy to an attempt to synchronize watches via the postal system, and suggests that remote medicine and self-driving cars will need far higher standards in order not to put lives at risk. He says, "modern computer programs only have probabilities on execution times, rather than the strong certainties that safety-critical systems require." -
Some Biodegradable Plastics Don't Live Up To Their Claims
ckwu writes From bread bags to beverage bottles, many plastics now contain additives designed to make the materials biodegradable. But a new study shows that plastics made with such additives do not biodegrade in the environment significantly faster than those without the compounds. Researchers prepared films of commercial plastics with three different types of additives supplied by their manufacturers. The researchers then treated the film samples to mimic disposal of such plastics in a compost pile, a landfill, and soil. After about six months of composting, a year and a half of landfill-like conditions, and three years of soil burial, the plastics with additives did not show any more evidence of biodegradation than plastics without them. -
Martian Canyons May Have Been Carved By Wind
sciencehabit writes Ancient canyons scar the surface of Mars, a relic from a time billions of years ago when rivers flowed on its surface. But water may not be the only factor that shaped these canyons—the wind whipping through them could be just as important, according to a new study of river canyons on Earth. Scientists studying chasms in the Andes mountains in northeast Chile have found that wind carves some canyons 10 times faster than water. The discovery may be significant for understanding how much water flowed on the surface of ancient Mars. -
Polymers Brighten Hopes For Visible Light Communication
ckwu writes Today nearly all computers, tablets, and smartphones have Wi-Fi capabilities, receiving and transmitting data over a range of radio frequencies. But a burgeoning technology known as visible light communication could someday carry those data in the same light that illuminates a room. Now a tag team of semiconducting organic polymers is bringing that dream one step closer. When excited with a blue LED, the polymer pair helps to create white light that can be rapidly switched on and off to encode information. A proof-of-principle device using the polymers sent data at 350 Mbps over a distance of 5 cm with minimal errors, a rate 35 times faster than a commercially available phosphor used for blue-light color conversion. -
Novel Fluorinated Compounds Discovered In Firefighters' Blood
ckwu writes: Perfluorinated compounds help firefighting foams rapidly flow over flaming liquids such as gasoline and jet fuel, cooling and quenching fires. But despite environmental scientists' concerns about these possibly toxic compounds, researchers don't know the identity of many of the chemicals in the mixtures on the market. For the first time, a new study borrows a medical research tool to pinpoint fluorochemicals in the blood of firefighters, identifying novel compounds that have never before been publicly reported. -
Deep-Frying Graphene Microspheres For Energy Storage
ckwu writes Materials scientists have constructed round, pom-pom-like graphene microparticles by spraying graphene oxide droplets into a hot solvent—a process akin to deep-frying. The technique could provide a simple, versatile means to make electrode materials for batteries and supercapacitors, possibly leading to devices with improved energy and power densities, the researchers say. The microparticles contain graphene nanosheets radiating out from their centers, which increases the exposed surface area of the graphene and creates open nanochannels that can enhance charge transfer. Electrodes made with the graphene microspheres had higher capacitance than those made with unassembled graphene sheets, demonstrating that the 3-D structure of the particles improved performance. -
Pantry Pests Harbor Plastic-Chomping Bacteria
MTorrice writes In the U.S. alone, consumers discard over 32 million tons of plastic each year, only 9% of which is recycled. Polyethylene is one of the most popular and, unfortunately, persistent types of plastics. Bags, bottles, and packaging made from the polymer accumulate in landfills and oceans across the globe. Scientists have lamented that the material isn't biodegradable because microbes can't chew up the plastic to render it harmless. However, a new study reports the first definitive molecular evidence that two species of bacteria, found in the guts of a common pantry pest, can thrive on polyethylene and break it apart. -
Elusive Dark Matter May Be Detected With GPS Satellites
An anonymous reader writes: Two researchers say time disparities identified through the network of satellites that make up our modern GPS infrastructure can help detect dark matter. In a paper in the online version of the scientific journal Nature Physics, they write that dark matter may be organized as a large gas-like collection of topological defects, or energy cracks. "We propose to detect the defects, the dark matter, as they sweep through us with a network of sensitive atomic clocks. The idea is, where the clocks go out of synchronization, we would know that dark matter, the topological defect, has passed by." Another reader adds this article about research into dark energy: The particles of the standard model, some type of dark matter and dark energy, and the four fundamental forces. That's all there is, right? But that might not be the case at all. Dark energy may not simply be the energy inherent to space itself, but rather a dynamical property that emerges from the Universe: a sort of fifth force. This is speculation that's been around for over a decade, but there hasn't been a way to test it until now. If this is the case, it may be accessible and testable by simply using presently existing vacuum chamber technology -
Researchers Direct Growth of Neurons With Silicon Nitride Microtubes
MTorrice writes: Bioengineers want to connect electronics and neurons to make devices such as new cochlear implants or prosthetic limbs with a seemingly natural sense of touch. They also could build synthetic neural circuitry to use to study how the brain processes information or what goes wrong in neurodegenerative diseases.
As a step toward these applications, a team of researchers has developed a way to direct the growth of axons, the connection-forming arms of neurons. They use transparent silicon nitride microtubes on glass slides to encourage the cells' axons to grow in specific directions. The cultured nerve cells grow aimlessly until they bump into one of the tubes. The axon then enters the tube, and its growth is accelerated 20-fold. Silicon nitride already is used in some orthopedic devices, and could serve as a substrate for electronics to interface with the growing neurons. -
Chemists Grow Soil Fungus On Cheerios, Discover New Antifungal Compounds
MTorrice writes: Many drugs that treat bacterial and fungal infections were found in microbes growing in the dirt. These organisms synthesize the compounds to fend off other bacteria and fungi around them. To find possible new drugs, chemists try to coax newly discovered microbial species to start making their arsenal of antimicrobial chemicals in the lab. But fungi can be stubborn, producing just a small set of already-known compounds.
Now, one team of chemists has hit upon a curiously effective and consistent trick to prod the organisms to start synthesizing novel molecules: Cheerios inside bags. Scientists grew a soil fungus for four weeks in a bag full of Cheerios and discovered a new compound that can block biofilm formation by an infectious yeast. The chemists claim that Cheerios are by far the best in the cereal aisle at growing chemically productive fungi. -
Antiperspirants Could Contribute to Particulate Pollution
MTorrice writes: Environmental scientists monitor particulate matter pollution because it poses risks to human health and can affect the climate. Ultrafine particles, up to 100 nm in diameter, are produced by vehicle exhaust and other combustion processes. They also form when volatile chemicals from other sources condense in the atmosphere, often through reactions triggered by sunlight.
Now atmospheric scientists propose that personal care products, such as antiperspirants, could be a potential source of ultrafine particulate matter. On the basis of data from the U.S. and Finland, they find that airborne nanoparticles in highly populated areas often contain silicon. They hypothesize that organic silicon compounds found in cosmetics waft into the air, get oxidized, and contribute to the growth of nanoparticles. -
Engineers Build Ultrasmall Organic Laser
ckwu writes: Researchers have made the tiniest organic laser reported to date. The 8-micrometer-long, 440-nanometer-wide device, which looks like a suspended bridge riddled with holes, is carved into a silicon chip coated with an organic dye. Integrated into microprocessors, such tiny lasers could one day speed up computers by shuttling data using light rather than electrons. The new organic laser is optically pumped—that is, powered by pulses from another laser. But it has a very low threshold—the energy required to start lasing—of 4 microjoules per square centimeter. The low threshold brings the device closer to engineers' ultimate goal of creating an organic laser that can run on electric current, which would be key for on-chip use. -
Researchers Report Largest DNA Origami To Date
MTorrice (2611475) writes Bioengineers can harness DNA's remarkable ability to self-assemble to build two- and three-dimensional nanostructures through DNA origami. Until now, researchers using this approach have been limited to building structures that are tens of square nanometers in size. Now a team reports the largest individual DNA origami structures to date, which reach sizes of hundreds of square nanometers. What's more, they have developed a less expensive way to synthesize the DNA strands needed, overcoming a tremendous obstacle to scaling up the technology. -
CPU's Heat Output to Amplify DNA Could Make Drastically Cheaper Tests
MTorrice (2611475) writes "Researchers have harnessed that heat from a computer CPU to run the polymerase chain reaction (PCR) to amplify DNA in a blood sample. The team developed software that cycles the temperature of the CPU to drive PCR's three distinct steps.The method allowed them to detect miniscule amounts of DNA from a pathogenic parasite that causes Chagas disease. They hope their technique will lead to low-cost diagnostic tests in developing countries." (Always good to put waste heat to a practical purpose.) -
Researchers Print Electronic Memory On Paper
MTorrice (2611475) writes Electronics printed on paper promise to be cheap, flexible, and recyclable, and could lead to applications such as smart labels on foods and pharmaceuticals or as wearable medical sensors. Many engineers have managed to print transistors and solar cells on paper, but one key component of a smart device has been missing—memory. Now a group of researchers has developed a method that uses ink-jet technology to print resistive random access memory on an ordinary letter sized piece of paper. The memory is robust: Engineers could bend the device 1,000 times without any loss of performance. The memory is not yet very dense, but could be: "Each silver dot they printed was approximately 50 microns across and separated from its neighbor by 25 microns, so each bit of memory is 100 microns on a side. At that size, a standard 8.5- by 11-inch piece of paper can hold 1 MB of memory. Der-Hsien Lien, the paper's lead author, says existing ultrafine ink-jet technology can produce dots less than 1 micron across, which would allow the same piece of paper to hold 1 gigabyte. Reading and writing the bits takes 100 to 200 microseconds" -
Reproducing a Monet Painting With Aluminum Nanostructures
MTorrice writes: Plasmonic printing is a recently developed method to create color images using different shapes and sizes of gold or silver nanostructures. It relies on the oscillations of electrons in the metal surfaces and can produce images with a resolution 100 times that of a common desktop printer. Now researchers have expanded the color palette of the technique using tiny aluminum-capped nanopillars. Each pixel consists of four nanopillars; tuning the diameters and arrangement of the pillars produced a palette of more than 300 different colors. Using these pixels, the researchers created a microscale reproduction of Claude Monet's "Impression, Sunrise." -
Happy Software Developers Solve Problems Better
First time accepted submitter HagraBiscuit (2756527) writes Researchers from the Faculty of Computer Science, Free University of Bozen-Bolzano, Bolzano, Italy, have quantified and analysed affective mood index against objective measures of problem-solving effectiveness for a group of software developers. From the report abstract: "The results offer support for the claim that happy developers are indeed better problem solvers in terms of their analytical abilities. The following contributions are made by this study: (1) providing a better understanding of the impact of affective states on the creativity and analytical problem-solving capacities of developers, (2) introducing and validating psychological measurements, theories, and concepts of affective states, creativity, and analytical-problem-solving skills in empirical software engineering, and (3) raising the need for studying the human factors of software engineering by employing a multidisciplinary viewpoint. -
Long-Lasting Enzyme Chews Up Cocaine
MTorrice (2611475) writes "Despite cocaine's undeniable destructiveness, there are no antidotes for overdoses or medications to fight addiction that directly neutralize cocaine's powerful effects. A natural bacterial enzyme, cocaine esterase, could help by chopping up cocaine in the bloodstream. But the enzyme is unstable in the body, losing activity too quickly to be a viable treatment. Now, using computational design, researchers tweaked the enzyme (full paper, PDF) to simultaneously increase stability and catalytic efficiency. Mice injected with the engineered enzyme survive daily lethal doses of cocaine for an average of 94 hours." -
First Transistors Made Entirely of 2-D Materials
ckwu (2886397) writes "Two independent research groups report the first transistors built entirely of two-dimensional electronic materials, making the devices some of the thinnest yet. The transistors, just a few atoms thick and hence transparent, are smaller than their silicon-based counterparts, which would allow for a super-high density of pixels in flexible, next-generation displays. The research teams, one at Argonne National Laboratory and the other at the University of California, Berkeley, used materials such as tungsten diselenide, graphene, and boron nitride to make all three components of a transistor: a semiconductor, a set of electrodes, and an insulating layer. Electrons travel in the devices 70 to 100 times faster than in amorphous silicon. Such a high electron mobility means the transistors switch faster, which dictates a display's refresh rate and is necessary for high-quality video, especially 3-D video." -
First Transistors Made Entirely of 2-D Materials
ckwu (2886397) writes "Two independent research groups report the first transistors built entirely of two-dimensional electronic materials, making the devices some of the thinnest yet. The transistors, just a few atoms thick and hence transparent, are smaller than their silicon-based counterparts, which would allow for a super-high density of pixels in flexible, next-generation displays. The research teams, one at Argonne National Laboratory and the other at the University of California, Berkeley, used materials such as tungsten diselenide, graphene, and boron nitride to make all three components of a transistor: a semiconductor, a set of electrodes, and an insulating layer. Electrons travel in the devices 70 to 100 times faster than in amorphous silicon. Such a high electron mobility means the transistors switch faster, which dictates a display's refresh rate and is necessary for high-quality video, especially 3-D video." -
Sulfur Polymers Could Enable Long-Lasting, High-Capacity Batteries
MTorrice writes "Lithium-sulfur batteries promise to store four to five times as much energy as today's best lithium-ion batteries. But their short lifetimes have stood in the way of their commercialization. Now researchers demonstrate that a sulfur-based polymer could be the solution for lightweight, inexpensive batteries that store large amounts of energy. Battery electrodes made from the material have one of the highest energy-storage capacities ever reported" Litihium Ion batteries should maintain capacity for about 1000 cycles, whereas Lithium-sulfur batteries traditionally went kaput after about 100. But it looks like they are getting pretty close to something feasible, from the article: "The best performing copolymer consisted of 90% sulfur by mass. Batteries using this copolymer had an initial storage capacity of 1,225 mAh per gram of material. After 100 charge-discharge cycles, the capacity dropped to 1,005 mAh/g, and after 500 cycles it fell to about 635 mAh/g. In comparison, a lithium-ion battery typically starts out with a storage capacity of 200 mAh/g but maintains it for the life of the battery, Pyun says." -
Confirmed: Earth's Oldest Rock In Australia
SpamSlapper writes "Australia's ABC Science reports that ancient zircon crystals discovered in Western Australia have been positively dated to 4.374 billion years, confirming their place as the oldest rock ever found on Earth, according to a new study. The research reported in the journal Nature Geoscience, means Earth began forming a crust far sooner than previously thought, following the giant impact event which created the Earth-Moon system 4.5 billion years ago." -
Hard Silicon Wafers Yield Flexible Electronics
MTorrice writes "By shaving off an ultrathin layer from the top of a silicon wafer, researchers have transformed rigid electronic devices into flexible ones. The shaving process could be used to fabricate parts for wearable electronics or displays that can roll up. Compared to similar techniques to make bendable silicon electronics, the new method is more cost-effective and produces more flexible devices, its developers say." -
Why Birds Fly In a V Formation
sciencehabit writes "Anyone watching the autumn sky knows that migrating birds fly in a V formation, but scientists have long debated why. A new study of ibises — where researchers took to microlight planes and recorded birds strapped with GPS in-flight — finds that these big-winged birds carefully position their wingtips and sync their flapping, presumably to catch the preceding bird's updraft and save energy during flight." -
Carbon Nanotubes and Spongy Polymer Help Transistors Stretch
MTorrice writes "To make future displays that roll, bend, and stretch, electronics makers need the circuits that control the pixels to be elastic. In particular, they need flexible transistors. Now researchers have combined a carbon nanotube mesh with a spongy ionic polymer to build super-stretchy transistors. The scientists can pull the devices to lengths 57% greater than their resting length without disrupting performance." -
Chefs Preview Surface Tension-Based Cocktail Garnishes
carmendrahl writes "Last fall, MIT researchers made news for developing two bioinspired cocktail toppers-- a moving cocktail boat and a floral pipette-- in collaboration with James Beard Award-winning chef José Andrés. Both the boat and floral pipette operate by taking advantage of surface tension-- either to propel the boat forward or to keep small drops of liquid inside the flower's petals. Some of those early garnishes were nominally edible. But to make them worthy of a restaurant debut requires balancing of flavors, temperature, density, and alcohol content, among other factors. Here's a look inside Andrés' company ThinkFoodGroup to see how the project is coming along. The toppers aren't available to the public just yet." -
Clear Solar Cells Could Help Windows Generate Power
ckwu writes "The vast real estate of windows in office buildings and skyscrapers could be a fruitful field for harvesting solar energy—if lightweight solar cells could be made with a high enough conversion efficiency and appealing aesthetics. Now researchers at Oxford University report semitransparent solar cells that might do the trick. The team made solar cells using a perovskite, a class of mineral-like materials that have properties similar to inorganic semiconductors and show sunlight-to-electricity conversion efficiencies of more than 15%. The team deposited a thin film of perovskite onto glass so that the material formed tiny crystalline islands. The islands absorb photons and convert them to electrons, while light striking the empty areas passes through. The result was a semitransparent solar cell with a grayish tint." -
Harvesting Power When Freshwater Meets Salty
ckwu writes "As a way to generate renewable electricity, researchers have designed methods that harvest the energy released when fresh and saline water mix, such as when a river meets the sea. One such method is called pressure-retarded osmosis, where two streams of water, one saline and one fresh, meet in a cell divided by a semipermeable membrane. Osmosis drives the freshwater across the membrane to the saltier side, increasing the pressure in the saline solution. The system keeps this salty water pressurized and then releases the pressure to spin a turbine to generate electricity. Now a team at Yale University has created a prototype device that increases the power output of pressure-retarded osmosis by an order of magnitude. At a full-scale facility, the estimated cost of the electricity generated by such a system could be 20 to 30 cents per kWh, approaching the cost of other conventional renewable energy technologies." -
How Heroin Addicts Helped Scientists Link Pesticides and Parkinson's
carmendrahl writes "Exposure to certain pesticides, including rotenone and paraquat, has been associated with a higher incidence of Parkinson's disease in population studies. But how did scientists come to think of a link between Parkinson's disease and pesticides in the first place? The answer involves the 1980s drug underworld, where criminals were synthesizing modified versions of illegal drugs such as heroin to stay one step ahead of the law. One molecule in some designer heroin cocktails, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), breaks down in the human body into 1-methyl-4-phenylpyridinium (MPP+), a nerve cell killer. Heroin addicts exposed to this molecule got Parkinson's-like symptoms. As for the connection to pesticides, MPP+ is a weed killer that was used in the 70s. It also closely resembles the structure of the pesticide paraquat. The saga, therefore, put scientists on high alert to the possibility that pesticides might play a role in developing Parkinson's." -
Sunlight Helps Turn Salty Water Fresh
MTorrice writes "With energy-efficient desalination techniques, water-starved communities could produce fresh water from salty sources such as seawater and industrial wastewater. But common methods like reverse osmosis require pumping the water, which uses a substantial amount of energy. So some researchers have turned to forward osmosis, because in theory it should use less energy. Now a team has demonstrated a forward osmosis system that desalinates salty water with the help of sunlight. The method uses a pair of hydrogels to absorb and squeeze out freshwater."