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NEWS RELEASE

December 2001

News about Science, Technology and Engineering at Iowa State University

Ames Lab project to help combat bioterrorism
Scientists at the U.S. Department of Energy's Ames Laboratory at Iowa State University are preparing a new tool that could help in the battle against bioterrorism. Formally known as Identification and Documentation of Currently Available Veterinary Science Resources, the project utilizes expertise at ISU's Veterinary Diagnostic Laboratory to compile an online database of existing information on the most deadly animal diseases that could damage the livestock industry, and, as in the case of anthrax, infect humans.

"It provides an invaluable resource to those on the front lines in defending against a bioterrorist threat," said Ames Lab associate scientist Gary Osweiler. "It will help veterinarians more quickly diagnose potentially deadly diseases, which in turn may help stop the spread of those agents." Osweiler is director of ISU's Veterinary Diagnostic Laboratory and co-principal investigator on the project with Walter Hyde, an ISU professor of veterinary medicine.

The database currently contains information on 14 of the most dangerous zoonotic disease agents, a listing of recognized experts for each agent and the diagnostic facilities testing for specific diseases. It combines information from veterinary medicine journals with practical information from project team surveys. The database is currently undergoing beta testing, but once it is fully operational, it will be accessible through a secure government Web site. For more information, contact Osweiler, (515) 294-1950, or Kerry Gibson, Ames Lab Public Affairs, (515) 294-1405.

New systems and control technology speed AFM processes
The principles for an ultra fast scanning microscope, being developed by an Iowa State University researcher, are breaking new ground in the field of advanced nano-engineering instrumentation. Murti Salapaka, an associate professor in electrical and computer engineering, has developed a prototype of a large scan nano-positioning device for an atomic force microscope (AFM). The device offers higher resolution and faster detection capabilities than currently available.

Using systems and control theory modeling, which have found limited application in AFM technology, Salapaka's group has significantly refined the scanning process by improving control mechanisms in AFM. Atomic force microscopes, used in biological and drug discovery fields and the semiconductor industry, provide images by "feeling" the minute structure of the sample's surface, much the way a phonograph needle "reads" the surface of a record. The ability to access precise images of cellular processes on a nanometer scale currently is hindered by the limitations of the instrument itself.

"Current imaging available at the nanometer scale provide images at very slow rates," Salapaka says. "Existing microscopes utilizing the dynamic mode depend on steady state data that typically require 3,000 cycles to extract information. Our new method, holds the promise of extracting information in 10 cycles, making it a 300- to 400-times faster imaging capability than what is available today."

Salapaka's work is in collaboration with North Carolina State University, Raleigh, and Asylum Research Inc., Santa Barbara, Calif. For more information, contact Salapaka, (515) 294-0398, or Sunanda Vittal, Engineering Communications, (515) 294-6750.

Magnetic refrigerator successfully tested
Using materials developed at the U.S. Department of Energy's Ames Laboratory, researchers have successfully demonstrated the world's first room-temperature, permanent-magnet, magnetic refrigerator. The refrigerator was developed by Astronautics Corporation of America, Milwaukee, as part of an agreement with Ames Lab. Instead of using ozone-depleting refrigerants and energy-consuming compressors like vapor-cycle refrigerators, the new refrigerator uses gadolinium metal that heats up when exposed to a magnetic field, then cools down when the magnetic field is removed.

"Previous successful demonstration refrigerators used large superconducting magnets, but this is the first to use a permanent magnet and operate at room temperature," says Karl Gschneidner Jr., an Ames Laboratory senior metallurgist and Iowa State University distinguished professor of materials science and engineering. Astronautics is now testing the concept to achieve larger temperature swings that will allow the technology to be used in home refrigerators, air conditioning, electronics cooling and fluid chilling units.

The magnetic refrigerator employs a rotary design, Gschneidner says. It consists of a wheel that contains segments of gadolinium powder and a high-powered, rare earth permanent magnet. The wheel is arranged to pass through a gap in the magnet where the magnetic field is concentrated. As it passes through this field, the gadolinium in the wheel heats up, exhibiting a large magnetocaloric effect. Water is circulated to draw the heat out of the metal, and as the gadolinium leaves the magnetic field, the material cools further as a result of the magnetocaloric effect. A second stream of water is cooled by the gadolinium and circulated through the refrigerator's cooling coils.

"The permanent magnets and the gadolinium don't require energy inputs to make them work," Gschneidner says, "so the only energy it takes is the electricity for the motors to spin the wheel and drive the water pumps." For more information contact Gschneidner, (515) 294-7931, or Kerry Gibson, Ames Lab Public Affairs, (515) 294-1405.

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