News Release

April 2012 story tips

Peer-Reviewed Publication

DOE/Oak Ridge National Laboratory

BIOLOGY -- When neutrons and simulation unite . . .

Scientific analysis of proteins, the workhorses of the cellular world, could become easier by uniting experimental and simulation techniques, according to research published in Biophysical Journal. A team led by Oak Ridge National Laboratory's Jeremy Smith demonstrated how the combination of high-performance computer simulation and a type of neutron analysis called spin echo can be used to study certain motions in proteins. When large chunks of proteins called domains move relative to each other, these interdomain motions can be detected with spin echo. "Neutron spin echo can detect motions on longer time scales, from nanoseconds to hundreds of nanoseconds, and very interesting motions in proteins occur on those time scales," Smith said. Enhanced interpretation of spin echo data will also aid studies of nonbiological materials such as polymers. [Contact: Morgan McCorkle, (865) 574-7308; mccorkleml@ornl.gov]

MICROSCOPY -- Transfer stage solution . . .

Preserving the integrity of air- or moisture-sensitive samples being transferred from a protective environment to a scanning electron microscope is now easier with a vacuum-tight transfer stage invented at Oak Ridge National Laboratory. Jane Howe and Lynn Boatner led a team that has solved a problem that has inexplicably hampered scientists for decades. "One of the challenges of using scanning electron microscopes and other vacuum-based analytical techniques to characterize lithium battery materials is because of their air and moisture sensitive nature," Boatner said. Even exposures of seconds can produce dramatic morphological and chemical composition changes. The ORNL team successfully used its transfer stage to study lithium-ion battery materials in two different scanning electron microscopes with no alterations. Details are outlined in a paper published in the Journal of Materials Science (Vol. 47, No. 3): http://www.deepdyve.com/lp/springer-journals/vacuum-tight-sample-transfer-stage-for-a-scanning-electron-microscopic-EiV21GnUpn. [Contact: Ron Walli, (865) 576-0226; wallira@ornl.gov]

ELECTRICITY -- Grid game changer . . .

Waste and inefficiencies in the nation's electric grid could be dramatically reduced with the implementation of a magnetic amplifier being developed by a team led by Aleks Dimitrovski of Oak Ridge National Laboratory's Energy and Transportation Science Division. If successful, the electromagnetic-based amplifier-like device would provide low-cost regulation of power flow, a feat that until now was prohibitively expensive. ORNL's controller could provide a reliable cost-effective solution to the problem that plagues the outdated and inefficient grid. "Ordinarily, such a device would require expensive superconductive wire, but the ferromagnetic core design of our device could serve as a low-cost alternative that is equally adept at regulating power flow," Dimitrovski said. [Contact: Ron Walli, (865) 576-0226; wallira@ornl.gov]

SUPERCONDUCTORS -- Surprising transitions . . .

Neutron scattering experiments performed on iron-based superconducting material at Oak Ridge National Laboratory and Canada's Chalk River Laboratories have unveiled surprising changes in the materials' subatomic structural and magnetic properties when subjected to relatively low pressures. The experiments on barium iron arsenide crystals revealed changes in spin-ordering and phase transitions that offer insight into the dynamics that enable high-temperature superconductivity. Boston University researcher Stephen Wilson, lead author of the Physical Review Letters paper, cited the triple-axis spectrometer at ORNL's High Flux Isotope Reactor along with the laboratory's high-quality crystal fabrication capability in the success of the experiments. "In general, the world-class instruments at HFIR and the high neutron flux there make difficult experiments like this one possible," Wilson said. [Contact: Bill Cabage, (865) 574-4399; cabagewh@ornl.gov]

FUSION -- Taking the heat . . .

The United States is responsible for 8 percent of the Toroidal Field Conductor that the huge experimental fusion reactor now being built in France requires. ITER will use 80,000 kilometers of low-temperature helium-cooled superconducting wire to generate the immense magnetic fields needed to confine the burning plasma. By September, said Kevin Chan, US ITER's Toroidal Field Coil Conductor project engineer, US ITER will have completed its share of that wire to support the toroidal field magnets to rein in the burning plasma. The internal temperature of that plasma will be 150 million to 200 million degrees Celsius -- more than 10 times the internal temperature of the sun. [Written by Agatha Bardoel; media contact: Ron Walli, (865) 576-0226; wallira@ornl.gov]

BIOLOGY -- Tracking mercury . . .

How to clean up the mercury in the environment is a major issue for the Department of Energy. Moreover, bioaccumulation of methylmercury is of global concern. Researchers at the Spallation Neutron Source and the Environmental Sciences Division are studying the internal dynamics of a remarkable family of bacteria that eats its way into mercury in nature, transforming it into less toxic forms, without itself being killed in the process. They use the Neutron Spin Echo instrument at SNS to look at the special dynamics inside a protein regulator on the bacteria that allows the bacteria to detect mercury. This regulator initiates the production of the molecular defense machinery that enables it to break down the contaminant. [Written by Agatha Bardoel; media contact: Ron Walli, (865) 576-0226; wallira@ornl.gov]

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