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Engineers receive NSF career grants

By Liz Crumbley

Spectrum Volume 20 Issue 29 - April 23, 1998

The National Science Foundation (NSF) has selected three Virginia Tech engineering faculty members to receive Faculty Early Career Development Program awards. These four-year grants are presented annually to a select roster of faculty members nation wide who have demonstrated early in their careers the potential to make significant contributions to engineering research and instruction.
Alex Haung, assistant professor of electrical and computer engineering (ECE), will use the career grant to further his research in developing a novel semi-conductor device for power-conversion applications. Energy has to be processed by power circuits, Huang explained, and the semi-conductor switches he is working on will make that process more efficient, resulting in reduced energy costs.
Huang, who joined the Virginia Tech faculty in 1994 after earning his Ph.D. in electrical engineering at the University of Cambridge in England, has researched the use of semi-conductor devices for power conversion for about 15 years. He came to Tech in part to work with ECE Professor Fred Lee, director of the Virginia Power Electronics Center, one of the leading research centers of its kind in the world.
The NSF grant also will enable Huang to develop educational tools. He will bring more advanced elements into his ECE course on power semi-conductor devices and will develop short courses in this area for power-utility engineers from throughout the U.S. Huang also plans to develop a semi-conductor modeling tool that can be accessed on the web by engineering students.
Mary Kasarda, assistant professor of mechanical engineering (ME), will develop the force-measurement capability of active magnetic bearings (AMB's) for use in manufacturing equipment in textile and other industries.
AMB's support a spinning rotor by suspending it in a magnetic field created by electromagnets surrounding the rotor, Kasarda said. Sensors on an AMB constantly monitor the position of the rotor's shaft as it spins, signaling electrical-current changes in the electromagnets to re-center the shaft. This monitoring capability also can be used to improve process and quality control in industries such as textiles and photographic film manufacturing. Because an AMB rotor does not touch other machine parts as it spins at high speeds, no lubricants are needed. The elimination of lubricants, which ruin quite a bit of fiber in textile manufacturing, will reduce costs and industrial pollutants, Kasarda said.
AMB's already have commercial applications in turbo-machinery, such as compressors and turbo-expanders. They also are being modified for use in heart pumps, which currently use blood as a lubricant.
Kasarda's NSF grant also will enable her to develop an undergraduate course in predictive and preventive maintenance for rotating machinery. Rodney Altizer, superintendent of the Virginia Tech Power Plant, has agreed to let Kasarda's students observe machine diagnostics and operations at the plant.
Kasarda, who has worked as an engineer for Ingersoll-Rand, Rotor Bearing Dynamics, and DuPont, joined the Tech faculty in 1997 after earning her Ph.D. from the University of Virginia. She said one reason she came to Tech was the opportunity to work with ME Professor Gordon Kirk in the Rotor Dynamics Laboratory.
Julio Martinez, assistant professor of civil engineering (CE), began developing the STROBOSCOPE construction-simulation-modeling system in 1992 at the University of Michigan, where he received his Ph.D. in 1996. His NSF career grant will enable him to continue work on the STROBOSCOPE system and related construction-simulation tools.
Unlike other construction simulation systems, STROBOSCOPE can model complex construction operations at the level of detail necessary to make decisions for their improvements, Martinez said. When working with computer simulation in construction design, engineers need to consider operation attack strategies as well as consumption of materials and time requirements. With STROBOSCOPE, he said, "these operation characteristics can be directly represented with little or no assumptions because the system can be programmed and extended by the user."
In addition, Martinez will use the NSF Career grant to develop teaching materials to familiarize CE students with STROBOSCOPE and other simulation tools.
Before coming to Virginia Tech, Martinez worked as a partner in a construction contracting firm in his native Dominican Republic, where he was in charge of rehabilitation of the water-supply system for the city of Azua. He also has been a claims analyst and engineer for Project Management Associates, Inc., in Ann Arbor, Michigan. Martinez said he came to Tech because the university's construction program "is respected as one of the top programs of its kind in the world."