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Via press release, researchers at Oak Ridge National Lab working toward a low-cost DNA sequencing tool for medical diagnostics have proposed using a single-walled carbon nanotube to thread a single strand of DNA from one reservoir to another, analyzing and sequencing the DNA in the process.

In such a device, the negatively charged DNA material, which is immersed in an electrolytic fluid, is propelled through the nanotube by an electric field.

When the current flowing through the nanotube was measured, researchers were surprised by the current of electrolytic ions that was much higher than any prediction.

Arizona State University’s Predrag Krstic and former ORNL researcher Sony Joseph performed atomistic molecular and fluid dynamics simulations at the University of Tennessee’s National Institute for Computational Sciences, located at ORNL.

Krstic and Joseph, in a paper published with their ASU and Columbia collaborators in the Jan. 1, 2010, issue of Science, attributed the mysterious current surge to the “slipping” of water molecules through the perfect and hydrophobic inner surface of the carbon nanotube and to trapped electrical charge.

Understanding such phenomena is key to the development of these single-molecule-detection instruments that would be inexpensive enough to become common in doctor’s offices.

“This is an example of how the front of science is increasingly multidisciplinary, with contributions by experimentalists and theorists in atomic and solid-state physics, chemistry, biology and engineering,” says Predrag.

The DOE announced that 24 million hours of supercomputing time out of a total of 1.6 billion available at Argonne and Oak Ridge National Labs have been awarded to investigate materials for developing lithium-air batteries that would be capable of powering a car for 500 miles on a single charge.

Through the Innovative and Novel Computational Impact on Theory and Experiment program, a research team including scientists from ANL, ORNL and IBM will use two of the world’s most powerful supercomputers to design new materials required for a lithium–air battery. Lithium-ion batteries, used in today’s emerging plug-in hybrid electric vehicles, currently have a maxiumum range of 40 to 100 miles before a recharge is necessary.

The calculations will be performed at both labs, which have two of the world’s top-ten fastest computers.

“Computation and supercomputing are critical to solving some of our greatest scientific challenges,” said DOE Secretary Chu. “This year’s INCITE awards reflect the enormous growth in demand for complex modeling and simulation capabilities, which are essential to improving our economic prosperity and global competitiveness.”

The INCITE program provides a collection of unique computational resources that enable scientists and engineers to conduct cutting-edge research in weeks or months rather than the years needed previously. The use of scientific modeling can accelerate scientific breakthroughs in areas such as climate change, alternative energy, life sciences, and materials science.

“Argonne is committed to developing lithium air technologies,” says Eric Isaacs, the lab’s director. “The obstacles to Li-air batteries becoming a viable technology are formidable, but the modeling and simulation capabilities of DOE’s supercomputers will help us accelerate the innovations required in materials science, chemistry and engineering.”

Micrographs of two single-phase FeTiO5 laminates with textured and untextured layers. Image (a), top, shows crack bifurcation within the textured layers. Image (b) shows tunnel cracks in the textured layer. Source: International Journal of Applied Ceramic Technology

The current issue of the International Journal of Applied Ceramic Technology reports on a Northwestern University group’s work related to using improved gelcasting techniques that allow new possibilities for manufacturing of certain laminates.

Gelcasting, a technique perfected at the Oak Ridge National Lab, is a method used to create large, near-net-shape ceramic and metal components with complex shapes from low-viscosity slurries composed of powders suspended in a liquid binder system. The components begin to be solidified when a chemical initiator is added to the slurry. This starts the formation of a polymer gel network. The slurry is quickly poured into a molds and allowed to dry. The additives and binders are burned out before sintering.

The team of Noah O. Shanti, David B. Hovis, Michelle E. Seitz, John K. Montgomery, Donald M. Baskin and Katherine T. Faber describe the use of more flexible gelcasting system – thermoreversible gelcasting – that allows more opportunities to manipulate the materials during the molding stage, something they found useful, for example, in toughening laminates.

The advantage of TRG over traditional gelcasting is that it is not time constrained (as long as the slurry temperature is kept above the transition temperature). Lamination is possible during gelcasting by adding successive layers of slurries selected because the properties and interfaces being sought. The teams describes concepts of tailoring the porosity and texture of the layers to, for example, strengthen the final laminate material by crack deflection, crack bifurcation and taking advantage of residual compressive stresses.

In one case, they describe the using the enhanced manipulation time to introduce a magnetic field to the materials during casting. The magnetic field aligns ceramic particles and allows the development of highly textured microstructures. The would not be possible using traditional gelcasting techniques because of the relatively brief window of opportunity before solidification begins.

The groups notes that while the use of TRG requires a good understanding of polymer chemistry, physics, and slurry rheology, not to mention drying and sintering kinetics, they predict the technique will find much use in applications ranging from strong bioceramic materials to solid oxide fuel cells.

R&D Magazine hosts the R&D 100 Awards, which are presented annually to researchers who have developed the year’s 100 most outstanding advances in applied technologies. ACerS just learned that 49 out of the 100 awards were presented to U.S. national labs. The labs competed in an international pool that included universities, start-ups and large corporations.

Winners on the list that may be of particular interest include:

• Ultrasensitive Electrospray Ionization Mass Spectrometry Source and Interface, Pacific Northwest National Lab
• FemtoScope: a time microscope, Lawrence Livermore National Lab
• High-temperature Silicon Carbide Power Module, Sandia National Lab
• Argonne/Envia Composite Electrode Material Technology to Enable Plug-in Hybrids and All-Electric Vehicles, Argonne National Lab
• Nanocrystal Solar Cells, Lawrence Berkeley National Lab
• Clay-Liquid CO₂ Removal Sorbent, National Energy Technology Lab
• Fire-Resistive Phase Change Material, Oak Ridge National Lab
• NanoCoral Dendritic Platinum Nanostructures for Renewable Energy Applications, Sandia National Lab
• Hard X-Ray Nanoprobe, Argonne National Lab
• Hyperspectral Confocal Fluorescence Microscope System, Sandia National Lab
• Spectral Sentry—Protecting High-Intensity Lasers from Bandwidth-Related Damage, Lawrence Livermore National Lab
• Superhard and Slick Coating, Argonne National Lab
• Rhombohedral Single Crystal SiGe, NASA Langley Research Center

The DOE is particularly pleased with the awards. “The Department of Energy’s national laboratories are incubators of innovation, and I’m proud they are being recognized once again for their remarkable work,” says DOE Secretary Steven Chu. “The cutting-edge research and development being done in our national labs is vital to maintaining America’s competitive edge, increasing our nation’s energy security and protecting our environment. I want to thank this year’s winners for their work and congratulate them on this award.”