Number 268

Automated, nondestructive inspection system characterizes atomic-level properties

Reconstruction of a PPMS material lattice structure that can show the effect of changes in the material properties during the cooling and heat treatment processes.

Researchers at DOE's Idaho National Laboratory have developed the Portable Positron Measurement System (PPMS), which non-destructively tests materials at the atomic level throughout the production process.

[Keith Arterburn, 208/526-4845,
keith.arterburn@inl.gov]

NETL adopts medical technique to study mobility of CO₂ in coal

NETL's Robert McLendon adjusts the CT scanner used in research at NETL. The scanner is used to measure in situ fluid displacement and sorption of fluids within mineral cores.

DOE's National Energy Technology Laboratory (NETL) is using computed tomography (CT), usually a medical technique, to assess the potential long-term storage of carbon dioxide (CO₂) in deep, unmineable coal seams. CO₂ concentration gradients were determined at the confining and pore pressures of the deep strata. This technique provides realistic and essential design information regarding flow and sorption rates and limits of CO₂ sorption. The data can be used in numerical simulations to predict results for target coal seams. A paper describing the approach and the observed results has been accepted for publication in the peer-reviewed journal, SPE-Reservoir Evaluation & Engineering-Reservoir Engineering.

[Linda Morton, 304/285-4543,
Linda.morton@netl.doe.gov]

Scientists capture 3D images of ‘frozen smoke’

Section and isosurface rendering of a 500-nanometer cube from the interior of the 3D volume. The foam structure shows globular nodes that are interconnected by thin beam-like struts.

Researchers have created a three-dimensional image of a material referred to as “frozen smoke.” Aerogel is an open-cell polymer with pores smaller than 50 nanometers in diameter. For the first time, Lawrence Livermore and Lawrence Berkeley scientists have peered into this material and created three-dimensional images to determine its strength and identify potential new applications.

Aerogel is an engineered material that can be used as catalysts for cleaner fuels and for the diffusion of water and oil in porous rocks. It’s not easy to see inside aerogel because the smallest pores are too small to be observed by conventional microscopes. Livermore scientist Anton Barty and Lawrence Berkeley researcher and former LLNL scientist Stefano Marchesini inverted coherent X-ray diffraction patterns to capture the 3D bulk lattice arrangement of a micrometer-sized piece of aerogel.

[Anne Stark , 925/422-9799,
stark8@llnl.gov]

Wireless networks improve by “hops” and bounds

With the potential to improve gas and oil pipeline monitoring, disaster recovery, and border surveillance, wireless ad-hoc and sensor networks hold the promise of extending our senses into the world, far beyond what is now possible. Instead of relying on a central base station as cellular networks do, these untethered devices—often called “motes”—use each other to transmit information through a series of “hops,” making the networks more versatile and mobile. The problem has been that in the past, researchers were able to make advances in only a few areas of performance, such as time delay, connectivity, or energy efficiency—a major consideration, given that most motes depend on batteries or some other portable power source. Sami Ayyorgun of DOE’s Los Alamos National Laboratory has come up with a scheme that shows for the first time that significant gains in many aspects of performance are possible, including connectivity, energy, delay, throughput, system longevity, coverage, and security.

[John Cannon, 505/665-8040,
jcannon@lanl.gov]

Quasicrystal Founder Gets His Due

Dan Schechtman

Scientific discovery is always met with a certain amount of skepticism. But Ames Laboratory scientist Dan Schechtman could hardly have been prepared  for the backslash he received back in 1982 when he announced he had found the icosahedral phase in rapidly solidified aluminum transition metal alloys, which opened up the field of quasi-periodic crystals as an area of study in materials science.

Shechtman’s discovery represented a paradigm shift in what had, until the early 1980s, been considered conventional wisdom in the science of crystallography: namely, that the atoms and molecules of all crystals are arranged in ordered, repeating patterns that extend in all three dimensions. However, by using electron diffraction rather than the more widely accepted application of X-ray diffraction, Shechtman discovered a limited class of crystals that, unlike normal crystals, demonstrate an icosahedral phase, making them only quasi-periodic.

Initially resisted by the scientific community, including a denunciation by two-time Nobel-prize winner Linus Pauling, Shechtman’s discovery of quasicrystals fundamentally altered the science of crystallography. And although it took almost a decade for the significance of quasicrystals to be recognized, within 10 years the International Union FO Crystallographers acknowledged the scope of Shechtman’s achievement, and officially changed the definition of what constituted a “crystal” in the scientific literature.

Schechtman, who is also a professor in the Department of Materials Science and Engineering at Iowa State University, received further vindication this past spring, as the 2008 recipient of the European Materials Research Society award. The award, which is presented only once every five years, is the highest recognition conferred upon a materials scientist by the society, which is Europe’s leading organization for the support and advancement of research in materials. Shechtman was formally recognized with the award at a ceremony and banquet in Strasbourg, France, in May.

Submitted by DOE's Ames Laboratory

DOE Pulse highlights work being done at the Department of Energy's national laboratories. DOE's laboratories house world-class facilities where more than 30,000 scientists and engineers perform cutting-edge research spanning DOE's science, energy, national security and environmental quality missions. DOE Pulse is distributed every two weeks. For more information, please contact Jeff Sherwood (jeff.sherwood
@hq.doe.gov, 202-586-5806)