by Richard Mandel

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Dipping a chunk of gold and silver alloy into an appropriate acid dissolves the silver away, leaving behind a form of gold with a surface filled with near-atomic size pores and voids. The spongelike structure of dealloyed gold has puzzled scientists until recently, when researchers at Johns Hopkins and three other universities developed computer models of the process, producing a string of mathematical equations that describe the material's evolution. It also supports a theory as to why the gold does not return to a dense crystalline form. "Our research," states Jonah Erlebacher, assistant professor of material science and engineering at JH, "leads us to believe the dealloyed gold atoms condense into little clumps that grow into the backbone of a porous structure." Nanoporous metals are desirable since they have much larger surface areas than an equal volume of non-porous material. According to Erlebacher, one use of such materials is as catalysts, since chemical reactions depend "on activity that takes place at the surface of the material. The more surface area you have, the more efficient the reaction will be." While gold itself is not considered a good catalyst, its inert quality would lend itself to coating with catalytic substances, including enzymes for sensor applications as in biomedical devices. The research may also shed light on why outer layers of certain alloys used in aviation turn porous, resulting in mechanical failure. Circle 400 - Johns Hopkins University or connect directly to their website at http://www.OneRS.net/105df-400

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The Department of Energy recently awarded a grant to Pavilion Technologies, Austin, TX, for working with Stanford University's Linear Accelerator Center to upgrade controls on the system. The joint project's first goal is to define requirements of a model-based solution that can adapt and optimize the complex control environment of electron-positron traps located at the end of the two-mile long accelerator. This particular zone, known as the "B-Factory," is a 1,200 ton particle detector used in scientific experiments studying distinctions between the decays of sub-atomic B mesons and their anti-matter counterparts, which may in turn explain why the universe favored the existence of matter over anti-matter following the Big Bang. Owing to the complexities of operation of the B-Factory, the system has required numerous operators and monitoring devices simultaneously controlling vacuum, particle beam signals, beam-steering and focusing magnets, and many other beam and systems parameters. Besides improving systems controls, the upgrade program also will demonstrate a system capable of rendering automatic decisions in less than a tenth of a second. Circle 401 - Pavilion Technologies Inc or connect at http://www.OneRS.net/105df-401 Circle 402 -
Stanford Linear Accelerator Center or connect at http://www.OneRS.net/105df-402