Univ. of Texas at Arlington engineering professors have received an Air Force grant to examine the material surface at the micro- and nano-scale level that will provide clues for predicting fatigue in aircraft parts. The new approach will rely on a scanning whitelight interferometric surface profiler integrated with a compact mechanical tester and an electron backscatter diffraction module to deliver in-situ 3-D surface profiling.
Imagine being able to tune the properties of a solid material just by flashing pulses of light on it. That is one potential payoff of electrons and atoms interacting with ultrashort pulses of light. The technology of ultrafast spectroscopy is a key to understanding this phenomenon and now a new wrinkle to that technology, observations of electron self-energy, has been introduced by Lawrence Berkeley National Laboratory researchers.
You can brush your teeth, and wash yourself and your clothes with a clear conscience. The most common soaps, shampoos and detergents actually pose a minimal risk to the environment. This is the conclusion of a comprehensive survey that covers more than 250 scientific studies over several decades.
Drawn relentlessly by their electrical charges, lithium ions in a battery surge from anode to cathode and back again. Yet, no one really understands what goes on at the atomic scale as lithium ion batteries are used and recharged. Using transmission electron microscopy, researchers are now glimpsing what can happen to anodes as lithium ions work their way into them. The “atomic shuffling” these ions perform leads to rapid anode failure.
A Duke Univ. team has found that nanoparticles called single-walled carbon nanotubes accumulate quickly in the bottom sediments of an experimental wetland setting, an action they say could indirectly damage the aquatic food chain. According to the research, the risk to humans ingesting the particles through drinking water is slight, but aquatic food chains might be harmed by molecules "piggybacking" on the carbon nanoparticles.
In a rare case of having their cake and eating it too, scientists from NIST and other institutions have developed a toolset that allows them to explore the complex interior of tiny, multi-layered batteries they devised. It provides insight into the batteries’ performance without destroying them, which results in both a useful probe for scientists and a potential power source for micromachines.
Researchers from the Univ. of Texas at Dallas have created technology that could be the first step toward wearable computers with self-contained power sources or, more immediately, a smartphone that doesn’t die after a few hours of heavy use. This technology taps into the power of a single electron to control energy consumption inside transistors, which are at the core of most modern electronic systems.
A novel x-ray technique used at the U.S. Department of Energy’s Advanced Photon Source has revealed surprising dynamics in the nanomechanics of operating batteries and suggests a way to mitigate battery failures by minimizing the generation of elastic energy. The method could open a path to wider use of these batteries in conjunction with renewable energy sources.
Scanning electron microscopes can determine chemical compositions with the help of energy dispersive spectrometers. However, lighter elements like carbon emit secondary fluorescence in an energy range insufficiently resolved by these instruments. Physicists have developed a potential solution to this problem by adding reflection zone plate optics to a specialized spectrometer that delivers high resolution from 50 to 1,120 eV.
If it's true that good things come in small packages, then NIST can now make anyone working with nanoparticles very happy. The institute recently issued Reference Material (RM) 8027, the smallest known reference material ever created for validating measurements of man-made, ultrafine particles between 1 and 100 nm in size.
using an aberration-corrected scanning transmission electron microscope, researchers have recently understood how defects in 2-D crystals such as tungsten disulphide can move, or dislocate, to other locations in the material. Understanding how atoms "glide" and "climb" on the surface of 2-D crystals may pave the way for researchers to develop materials with unusual or unique characteristics.
Researchers have discovered a way to create a highly sensitive chemical sensor based on the crystalline flaws in graphene sheets. The imperfections have unique electronic properties that the researchers were able to exploit to increase sensitivity to absorbed gas molecules by 300 times.
Researchers in Switzerland have succeeded in observing the “forbidden” infrared spectrum of a charged molecule for the first time. These extremely weak spectra offer perspectives for extremely precise measurements of molecular properties and may also contribute to the development of molecular clocks and quantum technology.
While freestanding graphene offers promise as a replacement for silicon and other materials in microprocessors and next-generation energy devices, much remains unknown about its mechanical and thermal properties. An international team of physicists, led by a research group at the Univ. of Arkansas, has recently discovered that heating can be used to control the curvature of ripples in freestanding graphene.
Researchers in Russia have developed a new method for the industrial synthesis of an ultra-hard material that exceeds diamond in hardness. An article recently published in Carbon describes in detail a method that allows for the synthesis of ultrahard fullerite, a polymer composed of fullerenes, or spherical molecules made of carbon atoms.
A comprehensive look at how tiny particles in a lithium-ion battery electrode behave shows that rapid-charging the battery and using it to do high-power, rapidly draining work may not be as damaging as researchers had thought—and that the benefits of slow draining and charging may have been overestimated.
A new study published in The Journal of Geology provides support for the theory that a cosmic impact event over North America some 13,000 years ago caused a major period of climate change known as the Younger Dryas stadial, or “Big Freeze.” The key to the mystery of the Big Freeze lies in nanodiamonds scattered across Europe, North America, and portions of South America.
Plastics are made of polymers, which are a challenge for scientists to study. Their chain-like strands of thousands of atoms are tangled up in a spaghetti-like jumble, their motion can be measured at many time scales and they are essentially invisible to some common x-ray study techniques. A better understanding of polymers at the molecular scale could lead to improved manufacturing techniques and the creation of new materials.
On the macroscale, adding fluorine atoms to carbon-based materials makes for water-repellant, non-stick surfaces, such as Teflon. However, on the nanoscale, adding fluorine to graphene vastly increased the friction experienced when sliding against the material. Through a combination of physical experiments and atomistic simulations, a Univ. of Pennsylvania research team has discovered the mechanism behind this surprising finding.
A new concept in metallic alloy design has yielded a multiple-element material that not only tests out as one of the toughest on record, but, unlike most materials, the toughness as well as the strength and ductility of this alloy actually improves at cryogenic temperatures. This multi-element alloy was synthesized and tested through a collaboration of researchers.
Researchers at Oak Ridge National Laboratory got a surprise when they built a highly ordered lattice by layering thin films containing lanthanum, strontium, oxygen and iron. Although each layer had an intrinsically nonpolar distribution of electrical charges, the lattice had an asymmetric distribution of charges.
The most familiar photovoltaic (PV) designs use rigid layers of silicon crystal, but recently inexpensive organic semiconductor materials have also been used successfully. At this time, organic PV devices are hindered by low efficiency, in part because quantifying their electrical properties is a challenge. Researchers have now developed a method that allows the prediction of the current density-voltage curve of a photovoltaic device.
A team of researchers in the U.S. and China have developed a new sensor that can detect and count nanoparticles, at sizes as small as 10 nm, one at a time. The researchers say the sensor, which is a Raman microlaser sensor in a silicon dioxide chip that does not need rare-earth ions to achieve high resolution, could potentially detect much smaller particles, viruses and small molecules.
Researchers have discussed the merits of surface-stress influence on mechanical properties for decades. Now, a new research platform, called nanomechanical Raman spectroscopy and developed at Purdue Univ., uses a laser to measure the "nanomechanical" properties of tiny structures undergoing stress and heating.
Bridges become an infrastructure problem as they get older, as de-icing salt and carbon dioxide gradually destroy the reinforced concrete. A new robot called C2D2 (Climbing Corrosion Detecting Device) is now in use in Switzerland and can check the condition of these structures, even in places that people cannot reach.
A team of scientists from Germany, Canada, and the United States has now developed a promising new measurement method that works without destroying anything yet offers nanoscale resolution. The method, an enhancement of resonant x-ray reflectometry identifies the chemical elements involved and is able to determine both the magnetic order and the electron distribution.
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