New materials designed with "nervous system"
Mechanical engineering professor Craig Rogers (who left in September to become dean of engineering at the University of South Carolina) has devised a way to decrease helicopter noise and vibration by putting "muscles" in the rotor blades. These shape-memory alloys, a type of "smart" material, behave in essence like a biological system that is able to think and adjust to changes around it. As the flight conditions change, the blades alter their shape to provide a smoother flight.
"Helicopter use is limited because of pilot fatigue," Rogers says. "The pilot is shaken too much to fly for a long distance." With the smart blades, pilots will travel more comfortably and noise levels on the ground will be reduced.
According to Rogers, planes and helicopters are designed to withstand disasters and, therefore, must be heavier and bulkier than is necessary for normal conditions. By using smart materials that change in shape and function based on need, components such as airplane wing flaps can be eliminated. The resulting product is smaller, lighter, and more fuel efficient.
Eventually, Rogers visualizes giving walls, bridges, and other structures a similar type of "internal nervous system," allowing them to sense and correct potential problems. He recently installed sensors on a navy pier in Norfolk that will alert authorities that damage is about to occur.
Rogers also is working with materials that can change from a liquid to a clay as needed.
Birth control zaps cockroach problem
A new, safe, and natural cockroach eliminator developed at Virginia Tech has passed field trials with flying colors and received a green light from the Environmental Protection Agency. The effect of the bait, in effect a birth control 'pill' for cockroaches, was discovered by Heather Wren (EDCI '87, ENT Ph.D.) while working as a research scientist at Virginia Tech.
The product eliminates the pest by inhibiting its development and reproduction. It is a nutritional metabolism disrupter composed of xanthine, found in potatoes and other foods, and oxypurinol, which is used to treat gout. Dominion Biosciences Inc. has leased the patent from Virginia Tech Intellectual Properties Inc. and will be marketing the product as "EcologixTM Cockroach Bait" next year.
"Usually someone discovers a new toxin, then looks for what it will kill. I look at non-toxic substances that have the ability to disrupt the cockroach's metabolism so that it will not be able to become sexually mature and reproduce," Wren says.
EcologixTM halts cockroaches' ability to form uric acid, which they require to mature and reproduce. They die without ever being able to grow and have young. In tests, the bait eliminated adult and nymph cockroaches within weeks. In contrast to pesticides, to which insects may develop immunity, the effect of Wren's substance can't be avoided, she says, unless the cockroaches "reconfigure their entire metabolic systems"--a nearly impossible task.
Parents at odds on joint custody
Most divorced mothers prefer to have sole custody of their children, although such an arrangement can be stressful and financially difficult. Fathers, on the other hand, prefer joint custody. Joyce Arditti, of the College of Human Resources' department of family and child development, discovered these preferences while examining custodial arrangements from parents' perspectives.
Her studies indicate that mothers with sole custody experience greater stress and feel more burdened emotionally and financially by parenting responsibilities than mothers with joint custody. Yet Arditti found that mothers with sole custody report greater satisfaction with the custody arrangement than do those with joint custody. "Children, while a major source of stress for them, were also a source of happiness and satisfaction," she says.
Fathers have more interaction with their children if custody is shared. For these men, says Arditti, "joint custody appears to represent a psychological benefit...(and) apparently gives them something that they otherwise do not believe they would have--control." On the other hand, mothers may equate joint custody with having less control.
Recently, 35 states have mandated a preference for joint custody.
