Researchers have made the first direct images of electrical currents flowing along the edges of a topological insulator. In these strange solid-state materials, currents flow only along the edges of a sample while avoiding the interior. Using an exquisitely sensitive detector they built, the team was able to sense the weak magnetic fields generated by the edge currents and tell exactly where the currents were flowing.
Waste from textile and paint industries often contains organic dyes such as methylene...
Electrolysis is often used to produce hydrogen that can be used for a storable fuel....
A magnetic phenomenon newly discovered by Massachusetts Institute of Technology researchers could lead to much faster, denser and more energy-efficient chips for memory and computation. The findings could reduce the energy needed to store and retrieve one bit of data by a factor of 10,000.
Researchers working to design new materials that are durable, lightweight and environmentally sustainable are increasingly looking to bone for inspiration. While researchers have come up with hierarchical structures in the design of new materials, going from a computer model to the production of physical artifacts has been a persistent challenge. Now researchers have developed an approach that allows them to turn their designs into reality.
Light-emitting diodes, or LEDs, are the most efficient and environmentally friendly light bulbs on the market. But they come at a higher up-front price than other bulbs, especially the ones with warmer and more appealing hues. Researchers at the Univ. of Washington have created a material they say would make LED bulbs cheaper and greener to manufacture, driving down the price.
Sandia National Laboratories researchers want airports, border checkpoints and others to detect homemade explosives made with hydrogen peroxide without nabbing people whose toothpaste happens to contain peroxide. That’s part of the challenge faced in developing a portable sensor to detect a common homemade explosive called a FOx mixture, made by mixing hydrogen peroxide with fuels.
In findings that could help overcome a major technological hurdle in the road toward smaller and more powerful electronics, an international research team involving Univ. of Michigan engineering researchers, has shown the unique ways in which heat dissipates at the tiniest scales.
Wonder material graphene can be made magnetic, and its magnetism can be switched on and off at the press of a button. This opens a new avenue towards electronics with very low energy consumption. In a report published by a Univ. of Manchester team shows how to create elementary magnetic moments in graphene and then switch them on and off. This is the first time magnetism itself has been toggled.
Using star-shaped block co-polymer structures as tiny reaction vessels, researchers have developed an improved technique for producing nanocrystals with consistent sizes, compositions and architectures—including metallic, ferroelectric, magnetic, semiconductor and luminescent nanocrystals. The technique relies on the length of polymer molecules and the ratio of two solvents to control the size and uniformity of colloidal nanocrystals.
Rice Univ. researchers have for the first time detailed the molecular mechanism that makes a particular combination of cement and polymer glue so tough. The theoretical research led to a fine picture of how hydrogen bonds control the properties of hybrid organic-inorganic materials. The finding has implications for understanding the interface bonding that is often a roadblock to improved composite properties.
Scientists at Ames Laboratory have discovered a new family of rare-earth quasicrystals using an algorithm they developed to help pinpoint them. Quasicrystalline materials may be found close to crystalline phases that contain similar atomic motifs, called crystalline approximants. And just like fishing experts know how to hook a big catch, the scientists used their knowledge to hone in on the right spot for their discovery.
The research team of Ulsan National Institute of Science and Technology paved a new way to affordable fuel cells with efficient metal-free electrocatalysts using edge-halogenated graphene nanoplatelets. The research team, for the first time, reportedly synthesized a series of edge-selectively halogenated graphene nanoplatelets by ball-milling graphite flake in the presence of chlorine, bromine or iodine, respectively.
Scientists from SLAC National Accelerator Laboratory and Stanford Univ. have used finely tuned x-rays at the Stanford Synchrotron Radiation Lightsource to pin down the source of a mysterious magnetism that appears when two materials are sandwiched together. Why is this mysterious? Neither material shows a hint of magnetism on its own.
Innovation in liquid chromatography instrument design and column technology over the last decade has led to substantial improvements in chromatographic throughput and resolution. This has been achieved by enabling the system to achieve pressures up to 15,000 psi, reducing the system contributions to peak broadening, and utilizing well-packed columns containing sub-2-micron particles.
Physicists at the U.S. Dept. of Energy's Ames Laboratory have discovered surprising changes in electrical resistivity in iron-based superconductors. The findings offer further evidence that magnetism and superconductivity are closely related in this class of novel superconductors.
A chemical that’s often the key ingredient in improvised explosive devices can be quickly and safely detected in trace amounts by a new polymer created by a team of Cornell Univ. chemists. The polymer, which potentially could be used in low-cost, handheld explosive detectors and could supplement or replace bomb-sniffing dogs, was invented in the lab of William Dichtel, assistant professor of chemistry and chemical biology.
Los Alamos National Laboratory scientists have designed a new type of nanostructured-carbon-based catalyst that could pave the way for reliable, economical next-generation batteries and alkaline fuel cells, providing for practical use of wind- and solar-powered electricity, as well as enhanced hybrid electric vehicles.
At the Advanced Light Source, scientists analyzed samples from a Roman breakwater that has been submerged in the Bay of Naples for over two millennia, revealing the secrets of crystal chemistry that allow Roman seawater concrete to resist chemical attack and wave action for centuries. The manufacture of extraordinarily durable Roman maritime concrete released much less carbon than most modern concrete does today.
Univ. of Calgary scientists are investigating how 'Alberta-grown' biomass—such as straw and wood left over from agricultural and forestry operations—could be used to clean up chemical contaminants in water from oilsands operations. This research project received $57,500 from the Climate Change and Emissions Management (CCEMC) Corp. though the Biological Greenhouse Gas Management Program.
Stanford Univ. scientists have dramatically improved the performance of lithium-ion batteries by creating novel electrodes made of silicon and conducting polymer hydrogel, a spongy material similar to that used in contact lenses and other household products. The scientists developed a new technique for producing low-cost, silicon-based batteries with potential applications for a wide range of electrical devices.
New work from Carnegie Institution scientists has studied how hydrogen, as a solid in one of three phases, behaves under extreme conditions. The team examined the structure, bonding, and electronic properties of highly compressed hydrogen using intense infrared radiation. Their experiments revealed that hydrogen takes a form under these conditions that differs remarkably from its other known structures.
SLAC National Accelerator Laboratory and Stanford Univ. researchers have developed a new printing process for organic thin-film electronics that results in films of strikingly higher quality. The printing process called FLUENCE—fluid-enhanced crystal engineering—results in thin films capable of conducting electricity 10 times more efficiently than those created using conventional methods.
Tiny particles of matter called quantum dots, which emit light with exceptionally pure and bright colors, have found a prominent role as biological markers. In addition, they are realizing their potential in computer and television screens, and have promise in solid-state lighting. New research at Massachusetts Institute of Technology could now make these quantum dots even more efficient at delivering precisely tuned colors of light.
In a recently published study, Columbia University researchers have demonstrated that graphene, even if stitched together from many small crystalline grains, is almost as strong as graphene in its perfect crystalline form. This work resolves a contradiction between theoretical simulations, which predicted that grain boundaries can be strong, and earlier experiments, which indicated that they were much weaker than the perfect lattice.
Bed bugs now need to watch their step. Researchers at Stony Brook University have developed a safe, non-chemical resource that literally stops bed bugs in their tracks. This innovative new technology acts as a man-made web consisting of microfibers 50 times thinner than a human hair which entangle and trap bed bugs and other insects.
Researchers have developed a new way of controlling the motion of magnetic domains—the key technology in magnetic memory systems. The new approach requires little power to write and no power to maintain the stored information, and could lead to a new generation of extremely low-power data storage. It controls magnetism by applying a voltage, rather than a magnetic field.
High-performance thermoelectric materials that convert waste heat to electricity could one day be a source of more sustainable power. But they need to be a lot more efficient before they could be effective on a broad scale in places like power plants or military bases, researchers say. A University of Michigan researcher has taken a step toward that goal.