To improve fuel cell module durability and predict longevity, researchers are studying the degradation mechanisms of the fuel cells that occur under real-world transit bus conditions. While quantifying the effects of electrode degradation stressors in the operating cycle of the bus on the membrane lifetime, the team has discovered links between electrode degradation and membrane durability.
Physicists understand perfectly well why a fridge magnet sticks to certain metallic...
To improve fuel cell module durability and predict longevity, researchers are studying...
A team of researchers at Columbia Engineering has used miniaturized electronics to...
Physicists working with optical tweezers have conducted work to provide an all-in-one guide to help calculate the effect the use of these tools has on the energy levels of atoms under study. This effect can change the frequency at which atoms emit or absorb light and microwave radiation and skew results; the new findings should help physicists foresee effects on future experiments.
Computer simulations conducted in Germany have shown that the reduction of natural dental wear might be the main cause for widely spread non-carius cervical lesions—the loss of enamel and dentine at the base of the crown—in our teeth. The discovery was made by examining the biomechanical behavior of teeth using finite element analysis methods typically applied to engineering problems.
The same material that formed the first primitive transistors more than 60 years ago can be modified in a new way to advance future electronics, according to a new study. Chemists at The Ohio State University have developed the technology for making a one-atom-thick sheet of germanium, and found that it conducts electrons more than ten times faster than silicon and five times faster than conventional germanium.
Cryogenic Ltd and the National Physical Laboratory in the U.K. have designed and developed the most accurate instrument for comparative measurements of electric current. The instrument can now be used by National Measurement Institutes and laboratories around the world, providing a more accurate standard for current ratio, and ensuring current measurement is not a limiting factor in innovation.
Efforts to eliminate contamination has allowed users of scanning electron microscopes (SEMs) to measure the exact features of a sample, not the sample features plus a layer of contamination. But contamination persists, which is why researchers at NIST are working to elevate microscope accuracy by eliminating the gradual buildup of carbonaceous material on a sample, introduced by the action of the charged particle beam.
Until now, atomic force microscopy-based measurements of chemistry and chemical properties of materials were generally not possible. Researchers at the University Illinois report that they have measured the chemical properties of polymer nanostructures as small as 15 nm, using a new technique called atomic force microscope infrared spectroscopy (AFM-IR).
Millions of people in Bangladesh and neighboring countries are chronically exposed to arsenic-contaminated groundwater, which causes skin lesions and increases the risk of certain cancers. According to an international team of scientists, human activities are not the primary cause of arsenic found in groundwater in Bangladesh. They found instead that the arsenic is part of a natural process that predates any recent human activity, such as intensive pumping.
Organic semiconductors hold promise for making low-cost flexible electronics—if they can perform in spite of frequent flexing and sharp bending. Scientists have recently demonstrated extremely flexible organic semiconductors that withstood multiple bending cycles in which the devices were rolled to a radius as small as 200 μm. The scientists worked with numerous crystalline devices they made and found no degradation in their performance.
Found in flat screens, solar modules, or in new organic light-emitting diode (LED) displays, transparent electrodes have become ubiquitous. But since raw materials like indium are becoming more and more costly, researchers have begun to look elsewhere for alternatives. A new review article sheds some light on the different advantages and disadvantages of established and new materials for use in these kinds of contact electrodes.
In the same week that a team of researchers in France announced the harmful effects of bisphenol A (BPA) on hormone levels in human tissue, researchers in Texas have demonstrated through experiments that the BPA substitute bisphenol S also disrupts hormone activity at an extremely low level of exposure, and in an even more problematic way.
A new study indicates that clay minerals, rocks that usually form when water is present for long periods of time, cover a larger portion of Mars than previously thought. In fact, the research team say clays were in some of the rocks studied by Opportunity when it landed at Eagle crater in 2004. But Opportunity doesn’t have the capability any longer to detect these clays, which were found using spectroscopic analysis from the Mars Reconnaissance Observer.
Scientists have used powerful X-rays from the Linac Coherent Light Source to study and measure, in atomic detail, a key process at work in extreme plasmas like those found in stars, the rims of black holes and other massive cosmic phenomena. The results explain why observations from orbiting X-ray telescopes do not match theoretical predictions, and pave the way for future X-ray astrophysics research using free-electron lasers such as LCLS.
Forty years after the last Apollo spacecraft launched, the science from those missions continues to shape our view of the moon. In one of the latest developments, readings from the Apollo 14 and 15 dust detectors have been restored by scientists. Digital data from these two experiments were not archived before, and it's thought that roughly the last year-and-a-half of the data have never been studied.
Detection of material failure is a difficult task for engineers, because cracks inside a material block can’t readily be identified from the outside. Researchers in Germany have now developed so-called self-reporting composite materials that can communicate their internal condition. The concept utilizes zinc oxide tetrapod crystals as a filler material for composites which at the same time reveals material failure by a visual signal under UV light.
Using an enhanced form of "chemical microscopy" developed at NIST, researchers there have shown that they can peer into the structure of blended polymers, resolving details of the molecular arrangement at sub-micrometer levels. The capability has important implications for the design of industrially important polymers like the polyethylene blends used to repair aging waterlines.
Results from field and lab tests have found that 7 to 9% of the kerosene in wick lamps—used for light in 250-300 million households without electricity—is converted to black carbon when burned. In comparison, only half of 1% of the emissions from burning wood is converted to black carbon. Kerosene is the primary source of light for more than a billion people in developing nations.
Scientists are reporting an increasing use of flame retardants in the main gathering spot for adults, children and family pets in the home—the couch. In recent study, Heather Stapleton and colleagues describe the first efforts to detect and identify the flame retardants applied to the foam inside couches found in millions of family rooms and living rooms across the U.S.
A major new initiative in the European Union is being launched to build a complete picture of how environmental pollutants influence health. Researchers are being asked to use smartphones equipped with GPS and environmental sensors to monitor study participants and their exposure to potential hazards. This information will be combined with blood and urine analysis to investigate whether exposure to risk factors leaves chemical fingerprints that can be detected in bodily fluids.
With their ultra short X-ray flashes, free-electron lasers offer the opportunity to film chemical reactions or atoms in motion. However, for this super slow motion the arrival time and the temporal profile of the pulses must be precisely known. An international team of scientists has now developed a measurement technique that provides complete temporal characterization of individual free-electron laser pulses.
A pinch of fine dust and sand from a patch of windblown material called “Rocknest” became the first sample of soil examined by the Mars Science Laboratory’s suite of laboratory instruments, called Sample Analysis at Mars. The sample was delivered on Nov. 9, allowing the mass spectrometry, gas chromatography, and laser spectrometry instruments to study the sample. Researchers are poring through the data now.
Infrared laser pulses, when used on a diatomic iodine molecule, can strip away outer valence molecules, causing the ionized molecule to explode and reallocate its electrons. Researchers in Germany have now observed this phenomenon without disturbing the process. This ability comes from ultrashort femtosecond X-ray pulses that are even quicker than the molecular explosion.
Recent work by scientists in Italy provides a new tool to better understand how sliding friction works in nanotribology, through colloidal crystals. By theoretically studying these systems of charged microparticles, researchers are able to analyze friction forces through molecular dynamics simulations with accuracy never experienced before.
New tests of nanostructured material developed by scientists at Rice University and Massachusetts Institute of Technology could lead to better armor against everything from gunfire to micrometeorites. The key, they found, was to use composites made of two or more materials whose stiffness and flexibility are structured in very specific ways—such as in alternating layers just a few nanometers thick.
One of the most urgently sought-after goals in modern science is the ability to observe the detailed dynamics of chemical reactions as they happen—that is, on the spatial scale of molecules, atoms, and electrons, and on the time scale of picoseconds or even shorter. A team of scientists at NIST has devised and demonstrated a highly unusual, compact, and relatively inexpensive x-ray source for an imaging system that may soon be employed to produce the kind of “molecular movies” that scientists and engineers need.
In a tornado, the individual air particles do not necessarily rotate on their own axis, but the air suction overall creates a powerful rotation. Similar vortex beams are being used in electron microscopy to allow researchers to determine the angular momentum of materials under examination. This ability provides valuable information about a material’s magnetic field. Researchers in Austria have recently produced particularly intense vortex beams.