MATERIALS -- A layer at a time . . .
Through several refinements to the tried and true method of pulsed laser deposition, Oak Ridge National Laboratory researchers have a new way to synthesize materials and conduct basic studies vital to creating new ones. By continuously monitoring the growth process and precisely controlling the amount of material deposited for each layer, researchers were able to grow artificial oxide crystals up to 5,000 atomic layers thick. They did this while preserving a perfectly flat surface. This unprecedented work involved atomic-scale control of individual layers of barium titanate, strontium titanate and calcium titanate. Hans Christen of the lab's Condensed Matter Sciences Division noted that the method can be used to produce materials lacking the symmetry found in almost all naturally occurring materials and can be designed in advance to exhibit specific desired physical properties. Consequently, this is a significant step toward long-sought designer materials expected to have a wide range of applications, particularly as sensors and switches and in the semiconductor industry. Funding for this research, which is published in the Jan. 27 issue of Nature, is provided by ORNL'S Laboratory Directed Research and Development program. [Contact: Ron Walli, 865-576-0226; wallira@ornl.gov]
HOMELAND SECURITY -- Safe harbors . . .
Ports in the United States and around the world could be protected with a threat vulnerability analysis system being developed by a team led by Robert Patton of Oak Ridge National Laboratory. The system, called Orion, will find, analyze and fuse information in support of intelligence, security and monitoring operations. "Our goal is to provide a system that can automatically retrieve information about worldwide shipping traffic, correlate this data, detect anomalies and then present this information to an analyst," Patton said. The ORNL technology helps overcome the problem of having to quickly make sense of information from thousands of sources. Patton noted that Orion builds on the lab's work with intelligent agents for the military, intelligence community and Department of Energy. Intelligent agents are software programs that scan the Internet, satellite images and electronic databases worldwide. The research, a collaborative effort between the Computational Sciences & Engineering and Engineering Science & Technology divisions, is funded by ORNL's Laboratory Directed Research and Development program. [Contact: Ron Walli, 865-576-0226; wallira@ornl.gov]
GEOGRAPHY -- Case closed . . .
"Cold case files" takes on new meaning for geochemists like Oak Ridge National Laboratory's Steven Turgeon, co-author of a Science paper that might explain a 248-million-year-old event that killed 90 percent of all marine species and 70 percent of terrestrial vertebrae species. This "extinction event" occurred at the Permian-Triassic boundary and is noteworthy because it had a global effect. After examining biomarkers and isotopic data from rocks from western Australia and southern China, Turgeon and colleagues theorize that many areas of the world's oceans became oxygen-depleted and sulfidic. This made the oceans and atmosphere toxic to living organisms. The researchers' conclusion was supported by the finding of remains of molecules derived from blue-green bacteria that thrive in regions where there is light but no oxygen. Also supporting this conclusion were carbon and sulfur isotope ratios that indicate a major global-scale disruption of geochemical cycles. This research, published on the Science Express website Jan. 20, was performed while Turgeon was with the University of Oldenburg in Germany. [Contact: Ron Walli, 865-576-0226; wallira@ornl.gov]
GENETICS -- Biosystems approach to skull disorder
Abnormalities of the face and skull rank among the most common birth defects in humans. Researchers at Oak Ridge National Laboratory are taking a systems biology approach to the problem, investigating a series of eight mutant mouse strains that could serve as animal models for deciphering the complex molecular interactions underlying skull development. Mutations in the gene that codes for a novel cell-signaling protein affected skull and spine growth in mice. The strains could serve as models for craniosynostosis, a condition where a child's skull bones grow very fast and fuse prematurely, preventing further brain growth and requiring major skull reconstruction. [Contact: Bill Cabage, 865-574-4399; cabagewh@ornl.gov]