This is an archived article. For the latest news, go to the Advance Homepage.
For more archives, go to the Advance Archive/Search Page
New engineering faculty launch
their careers with NSF awards
February 8, 1999
Joseph Helble grabbed his calculator, punched in some numbers and smiled. His quick guesstimate moments earlier was correct: it would take someone 23 days, counting non-stop - no sleep, no food - to go from zero to one million.
That problem, he recalled, appeared in a children's book he saw some months ago. Replicating the lesson or, better, creating a number of new ways to give children some perspective on the world around them, has been occupying some of Helble's time lately. The promise that he would create that display, for the Museum of Science in Boston, was one of the reasons Helble, an associate professor of chemical engineering, won a National Science Foundation CAREER Award last year. Criteria for the prestigious award include both teaching and research.
Helble's winning proposal also suggested he would research a somewhat larger challenge if he were to win one of the $210,000 grants. In his case, he and his assistants are trying to understand what happens to certain products, ceramics in particular, when they are built in nanoscale - a fraction of the size of a typical ceramic particle.
"We know how certain materials will react if they're large - a ceramic coffee mug will break if you drop it on the floor. But when something is this small, the rules (of composition of materials and their behavior) change," Helble says, slipping another analogy into the conversation to indicate the size of a nanometer. "A nanoscale particle is to a soccer ball what a soccer ball is to the earth."
The soccer ball analogy, he says, will probably make it to the Museum of Science. So may a human hair, which is actually 7,000 times the thickness of the materials Helble is using to build his experiments.
Barth Smets, an assistant professor of civil and environmental engineering and another recent CAREER Award winner, is also skilled at making a challenging science understandable.
Smets, using one of the oldest of human forms - the stick figure - reaches up from his chair and scratches onto his office blackboard a rough diagram of how several British workers were killed while exploding nitroglycerin that had seeped into the ground, settling into a pool deep beneath the earth's surface. Although exploding the substance is dangerous, the practice is not unusual, Smets says. Not yet at least.
The problem is that nitroglycerin - a compound used as an explosive in dynamite, as a gun and rocket propellant, and in other processes as well, including pharmaceuticals - is heavier than water. When it seeps into the earth, it settles at the bottom of
the water table, which can create problems. The trouble with burning or exploding the nitro - beyond environmental hazards - is that scientists may find a "puddle" in one spot, but don't necessarily notice a thread of the explosive running away from the site. And that thread may form another puddle - directly beneath the work crew.
Smets, however, who also holds an appointment in the Department of Molecular and Cell Biology, has found a microbe that, essentially, "eats" the dynamite, mineralizing the com- pound and rendering it harmless. He hopes the research, conducted with several other UConn faculty members and published in a 1998 edition of the Journal of Applied and Environmental Microbiology, will go beyond the theoretical and into the applied stage within the year.
But for Smets, that's only a small part of the picture. His primary research is to discover other microbes that can be used as a defense against a range of pollutants. Currently, says Smets, who also leveraged a $6,000 per year grant from the NSF for undergraduate research, scientists know there are microbes that react to certain pollutants, mitigating their effects. But, he says, if researchers can discover which organisms react to which toxins, and those organisms can then be genetically engineered, they can do their work more efficiently, on a wider range of pollutants, in a shorter time span.
"We know a horizontal exchange of genetic information among bacteria occurs. We want to see how it happens, short term. If we can see that the exchange is important, we can then find a way to improve the transfer or increase the speed of the transfer," Smets says.
Smets says there are millions of different microbes, each of which may react differently to a different toxin. After identifying organisms that react to a variety of pollutants, he hopes to find whether those traits are located on mobile genetic elements that could be transferred to a variety of microbes, which will then attack a variety of toxins and even heavy metals.
Kevin Murphy, an assistant professor of mechanical engineering and a third recent CAREER Award winner in the School of Engineering, also works with metal, but from a different angle - he's trying to find a better way to cut metal and other materials, through research in applied mechanics, nonlinear vibrations and stability.
Specifically, part of Murphy's reseach is in the area of EDM or Electric Discharge Machining, a method of cutting virtually any material using electrical pulses as the cutting tool. In traditional machining or grinding processes, cuts are made using metal or steel bits, which can wear quickly and must be replaced, a time consuming - and expensive - process.
The problem with EDM, Murphy says, and where his research comes to bear, is that the extremely thin copper wires used in the process vibrate beyond a certain speed, making the cuts less accurate. Slowing the pulses can eliminate the vibrations, but that dramatically slows the process.
"If we can understand the underlying vibration and stability characteristics of the wire, under a variety of cutting conditions, we should be able to eliminate these vibrations. This would greatly increase the accuracy and productivity of the process," says Murphy, who came to UConn in 1997.
Murphy also is engaged in another major research effort in the area of nonlinear vibrations of beams, plates and shells. These structural components are used in aerospace components such as external skin panels on aircraft and turbine blades, that are exposed to hostile aerodynamic, acoustic and high temperature environments which cause them to vibrate.