ENERGY -- The hydrogen juggle . . .
Discovering the ideal material for reversible storage of hydrogen could become a less daunting task because of work by a team led by David Singh of Oak Ridge National Laboratory's Condensed Matter Sciences Division. The challenge is to find a material that is efficient at storing hydrogen yet also has attractive thermodynamic properties that allow the hydrogen to be efficiently retrieved. Many intermetallic compounds are good for one but not both. In a paper published in Physical Review Letters (PRL 95, 056403, July 29, 2005), Singh and colleagues outline an approach found by computational modeling that allows them to tweak intermetallic compounds -- materials composed of two or more elemental metals. Included in the paper are some unexpected findings about materials with identical crystal structure but dissimilar hydrogen absorption properties. Ultimately, this research, funded by DOE's Office of Basic Energy Sciences, could help make fuel cell-powered vehicles a feasible alternative. [Contact: Ron Walli, 865-576-0226; wallira@ornl.gov].
ENVIRONMENT -- Native species restoration . . .
Non-native invasive plant species, such as kudzu, fescue and Japanese honeysuckle, have caused overgrowth problems for many land areas throughout the Southeast, literally choking off plant species native to the region and reducing diversity of plant habitats. Oak Ridge National Laboratory environmental sciences researchers have been experimenting with methods to reduce non-native species in specific areas of the laboratory's 20,000-acre environmental research park by converting them to areas more conducive to the growth of native plant species. A series of activities, including prescribed burns, selective application of herbicides, mowing and bush hogging has been undertaken over three years on 250 acres. These areas include abandoned fields, pine-beetle damaged stands, power line and roads rights-of-way, wetland restoration sites and remediated waste disposal landfills. The results have been mixed from areas that have been restored to full native grass communities to other locations where a combination of native grass and invasive species has reappeared. Research continues to determine the most effective methods to restore a balance in the growth of native plant species while promoting a diversity of habitats. [Contact: Fred Strohl, 865-574-4165; strohlhf@ornl.gov].
SECURITY -- Seal of approval . . .
Anywhere that special nuclear material is stored, the container must bear a seal that serves as a tamper indicating device. Figuring out which kind of a seal to use isn't simple: it depends on the type of container and material, the levels of security that exist, and the storage environment, among other parameters. For instance, some seals must operate in harsh environments and must maintain their integrity for many years, while others may be in fairly benign locations or might be changed often. Oak Ridge National Laboratory researchers have developed Seal Selection Tool software that provides administrators access to seal performance data collected from stringent DOE-NNSA designed tests. The tool will help those responsible for determining the best seal to use for specific applications to make faster and more informed decisions. The research is funded by DOE Office of Security and Safety Performance Assurance. [Bill Cabage, 865-574-4399; cabagewh@ornl.gov].
MILITARY-- Soldier's best friend . . .
Soldiers equipped with Oak Ridge National Laboratory's TRI-NAV system will know their precise location regardless of foliage, terrain, buildings and attempts by the enemy to jam global positioning system signals, says Steve Smith, lead researcher for the project and a member of ORNL's Engineering Science & Technology Division. The key to the proprietary system, which requires very little power for the user's unit, is that it seamlessly combines highly advanced GPS, an inertial navigation unit and the new ORNL-developed Theater Positioning System. The TRI-NAV (Triply Redundant Integrated Navigation and Asset Visibility) system also features precision timing to ensure that the three systems work together to provide instant and highly accurate location information, which is critical to soldiers in combat situations. A novel radio frequency scheme for the Theater Positioning System signals uses a special spread-spectrum system that makes it difficult to jam TRI-NAV. Gary Steimer of the National Security Directorate expects the final soldier unit to be about the size of a cellular telephone and accurate to better than one meter. The Department of Defense has funded portions of this project. [Contact: Ron Walli, 865-576-0226; wallira@ornl.gov].