News about Science, Technology and Engineering from Iowa State University
"Cool" materials turn into hot research
A group of materials that exhibit an enhanced ability to cool down and heat up in response to changes in magnetic fields -- a property discovered at the U.S. Department of Energy's Ames Laboratory at Iowa State University -- could have uses that extend far beyond temperature regulation. The materials, already being studied for magnetic-refrigeration technology, have possible uses in energy-conversion devices and in sensors to detect changes in magnetic field, temperature and pressure.
Now, a four-year Ames Lab project will provide a better fundamental understanding of why the materials respond so dramatically to changes in temperature and magnetic field. Scientists will explore the properties of gadolinium-silicon-germanium and several closely related materials. The alloys possess an unusual combination of three properties -- a giant magnetocaloric effect, giant magnetoresistance and colossal magnetostriction. Because of these properties, a relatively small change in the magnetic field surrounding the materials produces a tremendous change in their temperature, dimensions and electrical resistance.
"Some materials may possess one or two of these properties, but what's unique about this material is that all three changes take place in the same alloy and all three changes are quite large -- among the largest ever seen," said senior metallurgist Karl Gschneidner, who will direct the research project. For more information, contact Gschneidner, (515) 294-7931, or Susan Dieterle, Ames Lab Public Affairs, (515) 294-1405.
Simple steps can make your computer more secure
Recent instances of hackers breaking into corporate and government computer systems should be a sign to all computer users to guard against attacks on their machines, according to Jim Davis and Doug Jacobson, both ISU associate professors of electrical and computer engineering. Davis and Jacobson teach ISU students how to identify and thwart cyber attacks, and are co-directors of ISU's Information Systems Security Laboratory, a National Security Agency Center of Excellence.
There are more than just common viruses, like "Melissa" or the "Love Bug," floating around on the Internet these days. There also are "Trojan Horses" and "buffer overflows" and "denial of service" attacks that can bring a company's, or your, computer system to its knees. But there are steps to make your computer more robust in today's world of computer interconnectivity, Davis and Jacobson said.
"Simple preventative tasks early on can save you time, money and a considerable amount of hassle later on," Davis said. For more information contact Davis, (515) 294-0659; Jacobson, (515) 294-8307; or Skip Derra, ISU News Service, (515) 294-4917.
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