Washington beat 948

Pentagon launches web site a
for swapping technology ideas

The Defense Department has set up an Internet forum for open discussion of current and evolving technology topics. Called the Technology Navigator (TN), the site attracted engineers' attention in demonstrations at the June TechNet '97 exhibition in Washington, DC. The Defense Technical Information Center designed TN for use by industry, academia, and government agencies. The center envisions TN as a nexus for technologists to share research data and related information on products, pilot programs, studies, and findings. Users can post events, discuss ideas, develop problem-solving applications, and showcase products and services to a worldwide government audience. TN's address is http://www.dtic.mil/technav.

Many industries reclassified as SIC system is replaced

You may soon officially be in a different industry than you were at the end of last year--even if you haven't switched jobs. In the United States, the North American Industrial Classification System (NAICS) is replacing the Standard Industrial Classification, a system that federal, state, and local governments; the business community; and the general public have used since the 1930s. NAICS reflects mammoth changes in technology and in the growth and diversification of services. The 10 broad sectors in the old system are expanded to 20. One new one is the Professional, Scientific, and Technical Services Sector. It recognizes industries that rely primarily on human capital, including engineering. Among new categories are semiconductor machinery manufacturing, fiber-optic cable manufacturing, satellite communications, and cellular and other wireless communications. For details on NAICS, go to the Census Bureau Web site at http://www.census.gov/epcd/www/naics.asp.

New head-restraint designs range from simple to complex

While auto safety regulators struggle over setting new standards for head restraints, designers have come up with a variety of possibilities. The Insurance Institute for Highway Safety in Arlington, VA, surveyed what's new and what may be required in future cars. Among the simplest ideas is the addition of locks to adjustable head restraints so they won't be pushed down in crashes. Lear Corp. is working on a more sophisticated approach. Its system automatically positions the restraint according to the passenger's height. Two sensors in the top of the restraint would determine adjustments. BMW and Mercedes offer head restraints that reposition themselves whenever an occupant adjusts the entire seat. Volvo and Autoliv in Sweden are experimenting with a seat and head-restraint arrangement that rotates slightly in rear-end collisions to distribute forces more evenly. Some 1998 Saab models will have a new head restraint that pivots up and forward according to the amount of pressure the occupant puts on the seat back.

Sharper leading edges foreseen from tests of thermal material

Ground and flight tests this year of ceramic materials that withstand ultra-high temperatures present exciting possibilities to designers of aerospace vehicles. The materials have remained stable at temperatures between 1,700 and 2,000C in the presence of high-velocity dissociated air, like that encountered during a vehicle's reentry from outer space. The tests are done in arcjet facilities of the National Aeronautics and Space Administration. More spectacular was the materials' performance as the covering for a test nose cone that plummeted into the Pacific at a blistering speed from outer space. The reentry vehicle had a nose tip with a radius of only 0.141 inch. Because these new ceramic materials do not melt during reentry along trajectories similar to those taken by the Space Shuttle, it appears that engineers can put sharper edges on space vehicles. Sharp-body designs offer reduced drag and enable craft to reenter the atmosphere from any orbit and land at any location.

Symposium explores geometries of motion generation, control

A growing body of techniques employing dynamic systems and geometric mechanics is entering the world of motion controls. This was underscored in a symposium held at the National Academy of Sciences in Washington, DC. Proceedings of the symposium are now in print. The report covers several areas including robotic movement, motor miniaturization, and motion engineering. One paper is by Roger W. Brockett, professor in the Division of Applied Science at Harvard University. "In the not too distant future," he writes, "we expect to see some of these ideas being applied to new problems in biological motion control, mechanical design, electronics, and in areas we cannot yet anticipate." You can get copies of the report, Motion, Control, and Geometry (ISBN 0-309-05785-X), by writing to the Board on Mathematical Sciences, National Research Council, 2101 Constitution Avenue, NW, Washington, DC 20418.