April 2000

News about Science, Technology and Engineering at Iowa State University

Ames Lab technique to guarantee strength in metal parts
Using nondestructive evaluation techniques that determine a part's integrity without destroying it, scientists in the Ames Laboratory's Metallurgy and Ceramics Program are developing a method to guarantee the strength of mass-produced parts made from powdered metals. Scientists Jim Foley and Dave Rehbein are pioneering the technique, which uses a commercial, custom-built electromagnetic acoustic transducer that operates at elevated temperatures.

The technique enables scientists to observe sintering, the process by which powdered metals are fused together with pressure and heat, and to develop formulas for the correct processing conditions. Using permanent magnets and electrical coils on either side of a pressed powdered metal part as it sinters in a furnace, the transducer produces eddy currents that create sound waves inside the metal. Sound pulses respond to the strength of the metal's bonds by dying out when bonds are weak or bouncing back and forth in pinball fashion when strong. In combination with the magnetic field, the sound waves produce electrical voltage that is measured by an oscilloscope and visible on a computer monitor.

Foley and Rehbein are confident they are on the right track. Results indicate a correlation between the output voltage and the load-bearing capacity of the sintered alloys. Their technique may one day be used to guarantee the strength of parts on automotive assembly lines, but will always be a valuable inspection tool for new alloys. For more information, contact Foley, (515) 294-8252; Rehbein, (515) 294-8215; or Danelle Baker-Miller, Ames Lab Public Affairs, (515) 294-5635.

QuarkNet works to generate physics excitement in high schools
Iowa State University physics professor John Hauptman wants high school students to feel the excitement of physics, the same excitement he feels while working on a high-energy physics experiment. Hauptman, who was part of the international team that discovered the top quark in 1995, now is part of the National Science Foundation's international outreach project called QuarkNet. The project is an effort to make physics less abstract and more hands on.

"The overall goal is to get teachers involved and excited about high-energy physics," Hauptman says. "Then, they go back to the classrooms and share their experiences with their students."

Hauptman and Nural Akchurin, of the University of Iowa, are working with high school teachers Pete Bruecken (Bettendorf High School) and Jeff Dilks (Ames High School) to set up a three-week institute this summer for up to 10 Iowa high school teachers. The idea is to teach them about some of the basics of high-energy physics, like conservation laws of nature, quarks and leptons, and the standard model. They also will visit the Fermilab accelerator, near Chicago.

Iowa has one of the initial 12 centers of QuarkNet. Hauptman, Akchurin, Bruecken and Dilks were involved in last summer's activities, which included a trip to Fermilab. There they learned about particle physics and accelerators. Once back in Ames, the high school teachers helped design an extremely fast particle detector and tested it at CERN, the European high-energy physics accelerator facility in Geneva, Switzerland.

"NSF has always been concerned with science education, but QuarkNet directly brings high school teachers into research projects," says Hauptman, who would like to see high school students eventually taking part in high-energy physics experiments. For more information contact Hauptman, (515) 294-8572, or Skip Derra, News Service, (515) 294-4917.

Science Bound celebrates its 10th year
Science Bound has many reasons to celebrate. This is the 10th year that the program has provided enhanced science and technology opportunities to minority students in secondary schools. In May, one of the first students to participate in the program will receive a college degree.

Science Bound was created to increase the number of minority students in the Des Moines Public Schools who pursue science and technology degrees. The program, developed by Iowa State University and the Institute for Physical Research and Technology, involves students in grades 8 through 12. The program shows students how math and science can relate to careers. It also increases their math and science confidence through hands-on experiences, many of which occur at ISU with faculty, staff and undergraduate students. Students who successfully complete the program and pursue a science or technology degree at ISU receive a full-tuition scholarship.

Charles Stewart will be the first Science Bound student to receive a degree from ISU. Stewart, who joined the program shortly after it began, will receive a bachelor's degree in agricultural biochemistry on May 6. Thirty-two former Science Bound participants now attend ISU, and 15 high-school seniors hope to follow their example. For more information, contact Anita Rollins, Science Bound, (515) 294-4985, or Bob Mills, IPRT Public Affairs, (515) 294-1113.

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