25-04-2012   -   Chemistry

Wed 25 Apr 2012 Chemists explain the molecular workings of promising fuel cell electrolyte. Researchers reveal how protons move in phosphoric acid sheds new light on the workings of a promising fuel cell electrolyte. Phosphoric acid fuel cells were the first modern fuel cell types to be used commercially and have found application as both stationary and automotive power sources. Their high efficiency as combined power and heat generators make them attractive targets for further development. In the cell, phosphoric acid functions as the medium (or "electrolyte") that transports protons produced in the reaction that decomposes the fuel across the cell. Indeed, phosphoric acid has the highest proton conductivity of any known substance, but what makes it work so well as a proton conductor has remained a mystery. Efficient proton transport across a fuel cell is just one of several technical challenges that must be tackled before this technology can be applied on a massive scale. The key to this problem is the identification of a suitable electrolyte material. Hydrated polymers are often employed, but these must operate at temperatures below the boiling point of water, which limits their utility. Phosphoric acid fuel cells and other phosphate-based cells, by contrast, can be operated at substantially higher temperatures. Chemists have sought a molecular level understanding of proton conduction phenomena for more than 200 years. The earliest studies concerned water and can be traced back to a landmark paper in 1806 by the German chemist Theodor von Grotthuss. more

  05-04-2012   -   Geology

Thu 5 Apr 2012 For the first time, instrumentation aboard two NASA missions operating from complementary vantage points watched as a powerful solar storm spewed a two million-mile-per-hour stream of charged particles and interacted with the invisible magnetic field surrounding Earth. The storm, observed two years ago on April 5, 2010, also is thought to have caused an important communications satellite, Galaxy-15, to founder and drift, taking almost a year to return to its station. Understanding how solar events develop and impact satellites is like understanding the processes that cause extreme weather events on Earth to develop and destroy homes and businesses. more

  29-03-2012   -   Energy

Thu 29 Mar 2012 A new dimension for solar energy. Innovative 3-D designs can more than double the solar power generated from a given area. Intensive research around the world has focused on improving the performance of solar photovoltaic cells and bringing down their cost. But very little attention has been paid to the best ways of arranging those cells, which are typically placed flat on a rooftop or other surface, or sometimes attached to motorized structures that keep the cells pointed toward the sun as it crosses the sky. So far, individual 3-D toweres has been modeled. A next step is to study a collection of such towers, accounting for the shadows that one tower would cast on others at different times of day. In general, 3-D shapes could have a big advantage in any location where space is limited, such as flat-rooftop installations or in urban environments, they say. Such shapes could also be used in larger-scale applications, such as solar farms, once shading effects between towers are carefully minimized.more

  20-03-2012   -   Physics

Tue 20 Mar 2012 Ultracold experiments heat up quantum research. Physicists have experimentally demonstrated for the first time that atoms chilled to temperatures near absolute zero may behave like seemingly unrelated natural systems of vastly different scales, offering potential insights into links between the atomic realm and deep questions of cosmology. This ultracold state, called “quantum criticality,” hints at similarities between such diverse phenomena as the gravitational dynamics of black holes or the exotic conditions that prevailed at the birth of the universe. The results could even point to ways of simulating cosmological phenomena of the early universe by studying systems of atoms in states of quantum criticality. more

  11-03-2012   -   Biology

12 Mar 2012 Planarian genes that control stem cell biology identified. A novel approach to identify and study the genes that control stem cell behavior in planarians has been reported. Intriguingly, at least one class of these genes has a counterpart in human embryonic stem cells. "This is a huge step forward in establishing planarians as an in vivo system for which the roles of stem cell regulators can be dissected" . Planarians (Schmidtea mediterranea) are tiny freshwater flatworms with the ability to reproduce through fission. After literally tearing themselves in half, the worms use stem cells, called cNeoblasts, to regrow any missing tissues and organs, ultimately forming two complete planarians in about a week. Unlike muscle, nerve, or skin cells that are fully differentiated, certain stem cells, such as cNeoblasts and embryonic stem cells are pluripotent, having the ability to become almost cell type in the body. Researchers have long been interested in harnessing this capability to regrow damaged, diseased, or missing tissues in humans, such as insulin-producing cells for diabetics or nerve cells for patients with spinal cord injuries. more

  11-03-2012   -   Chemistry

12 Mar 2012 Liquid water diffusion at molecular level. Researchers have described for the first time the diffusion of liquid water through nanochannels in molecular terms. Nanochannels are extremely tiny channels with a diameter of 1-100 nanometers that scientists use to study the behavior of molecules. This might have an important impact on water desalinization and filtration methods. The introduction of graphene membranes and carbon nanolayers will revolutionize water desalinization and filtration processes, as water diffuses rapidly through these materials when their pores are 1nm in diameter.more

  11-03-2012   -   Nuclear

11 Mar 2012 Low Levels of Fallout from Fukushima. Fallout from the March 2011 Fukushima Dai-ichi nuclear power facility in Japan was measured in minimal amounts in precipitation in the United States in about 20 percent of 167 sites sampled in a new nationwide study. The U.S. Geological Survey led the study as part of the National Atmospheric Deposition Program (NADP). Levels measured were similar to measurements made by the U.S. Environmental Protection Agency in the days and weeks immediately following the March 2011 incidents, which were determined to be well below any level of public health concern.more

  11-03-2012   -   Physics

Sat 10 Mar 2012 Single-atom transistor is end of Moore's Law; may be beginning of quantum computing. The smallest transistor ever built - in fact, the smallest transistor that can be built - has been created using a single phosphorous atom by an international team of researchers. The single-atom device is less about improving current technology than building future technology.more

  22-12-2011   -   Chemistry

Thu 22 Dec 2011 Chemicals and biofuel from wood biomass. A new method makes it possible to use microbes to produce butanol suitable for biofuel and other industrial chemicals from wood biomass. Butanol or butyl alcohol can refer to any of the four isomeric alcohols of formula C4H9OH. Butanol is particularly suited as a transport fuel because it is not water soluble and has higher energy content than ethanol. more

  22-12-2011   -   Physics

Wed 21 Dec 2011 Researchers One Step Closer to Realizing Future Nanoscale MRI Instrument. The new advancements aims at developing a nanoscale magnetic imager consisting of individual electrons enclosed in a diamond crystal. The major challenge in realizing such a tool is the difficulty in accurately measuring a magnetic field utilizing the resonance of the individual electrons inside the diamond crystal. Magnetic imaging allows researchers to determine a limited scope of fields from molecules close to the resonant frequency of the sensor, which in turn complicates the imaging process. Dutt stated that to achieve this, highly advanced image processing and other methods are required. The research team employed quantum computing processes to eliminate the limitations of the hardware to see the whole magnetic field. By expanding the field, the team has increased the ratio between the optimum measurable field strength and field accuracy by a factor of 10 when compared to the earlier standard methods, paving the way for realizing a future nanoscale MRI tool that is capable of identifying locations of atoms without damaging them and analyzing properties of cells, materials and molecules in a noninvasive manner.more

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