Innovative technique fingerprints corrosion
Scientists have developed some amazing techniques to fingerprint everything from DNA found in blood at crime scenes to magnetic particles in credit cards. Now, chemical engineers at Washington University in St. Louis have added another fingerprinting technique: corrosion detection. Using a multifaceted signal-processing procedure call wavelets, the researchers can detect two different types of corrosion in metallic equipment, while a monitoring sensor tells process-control engineers where corrosion is taking place in a pipe, vessel, or machinery. It also advises when to replace the part before corrosion reaches a certain level. Current monitoring devices in the oil industry and at power and chemical-refining plants fail to detect corrosion at least 50% of the time, say the researchers. Fax Susan M. Killenberg at (314) 935-4259.
'Smart' material promises safer air travel
Researchers from the Aeroelasticity Branch of NASA and MIT have tested a new technology that could significantly affect the future of air travel. The concept uses piezoelectric "smart" material actuators developed by Active Control experts, and electronic feedback control. The object: to inhibit unwanted vibrations in an aircraft wing. In the test, a flexible composite wing used sensors to detect vibrations, and piezoelectric actuators to oppose vibrational forces. The NASA Langley/MIT team developed a computer control system, using active feedback algorithms, to manage the sensors and actuators and suppress the flutter. Preliminary test results of the wing in a wind tunnel showed a 6% increase in the speed at which the model can safely fly, without encountering such flutter. The technology, say the researchers, could also reduce the transmission of aerodynamic disturbances to an aircraft's fuselage for improved passenger comfort. Fax Adam Bogue at (617) 577-0656.
Aircraft inspection process found reliable
Eddy current inspection, a common way to detect cracks in aircraft, has been shown to be reliable in spotting damage before it becomes severe. So report Sandia National Laboratories researchers who evaluated inspectors for a Federal Aviation Administration study. More than half the inspectors observed at nine major commercial airlines and maintenance facilities achieved detection rates that exceeded 95% for cracks that measure 0.1 inch, the target minimum length for routine detection. With larger cracks, the probability of detection proved even higher. "Many of the inspectors overcame less-than-optimum field inspection conditions, while achieving reliabilities near those obtained under laboratory conditions," adds Floyd Spencer, the report's author. Fax (505) 844-8066.
Green the theme for these red signals
Philadelphia taxpayers are getting relief from higher electric bills. Credit the city "going in the red"-red traffic lights, that is. Chief Engineer John M. O'Connell has underway a program to convert the red lights from energy-hungry incandescent bulbs to light-emitting diodes (LEDs) supplied by R&M Deese, Inc, Anaheim, CA. The switch results in savings of $25 to $50 per light. With 28,000 lights on the streets, eventual savings could reach $1 million or more a year. Moreover, the lamps no longer will need replacing. Once green LEDs make the scene (they still lack the needed light output and cost benefits of their red counterparts), the city could reap another $1 million or