Technology Bulletin

Warning system for fatigued drivers closer to reality

According to estimates from the National Highway Traffic Safety Administration, at least 100,000 vehicle crashes, 1,500 fatalities, and 71,000 injuries each year can be directly linked to driver fatigue. In addition to human suffering, these accidents rack up an additional $12.5 billion in costs related to diminished productivity and property loss. While science has yet to find a fail-safe solution for the "asleep-at-the-wheel" syndrome, research from Washington University (St. Louis) and other laboratories is providing important clues on the bio-mechanics of driver fatigue. Such studies could pave the way for the development of an on-board alarm system that can rouse a driver who is dozing toward catastrophe. "Our research suggests that fatigued drivers become increasingly susceptible to accidents long before they actually fall asleep at the wheel," reports John Stern, professor of psychology at Washington U. Stern teamed with researchers from national labs to study how well professional truck drivers perform in a driving simulator that mimics conditions faced by long-haul, big-rig operators. The study used sophisticated cameras, electroencephalograms, and other devices to precisely measure eye and head movements, pupil diameter, and blink rates, while simultaneously recording details of driver and vehicle performance. The research suggests predictions can be made about various aspects of driver performance based on the movements of a driver's eyes. It also envisions that a system can be developed to capture this data and use it to alert people when their driving has become significantly impaired by fatigue. "Some researchers suggest that such a system will be available in one or two years," Stern adds, "but I think it's more likely to be five years or more before a workable and affordable system is available." E-mail gerry_everding@aismail.wustl.edu

NASA simulates molecule-sized gears that repair themselves

Thanks to simulation of molecule-sized gears by a NASA supercomputer, the prospect looks brighter that products made of thousands of tiny machines that could self-repair or adapt to the environment can ultimately be constructed. Al Globus, a computer scientist at Ames Research Center (Moffett Field, CA) co-authored a paper that helps explain how this may come about. The Ames researchers simulated attaching benzyne molecules to the outside of a nanotube to form gear teeth, Globus writes. Nanotubes are molecular-sized pipes made of carbon atoms. "You also need a cooling system for gears," Globus explains. The researchers used the supercomputer to replicate successful cooling of the tiny gears using helium and neon gases. To "drive" the gears, the computer also simulated a laser that served as a motor. The laser creates an electric field around the nanotube to put a positive-charged atom on one side and a negative-charged atom on the other. The electric field drags the nanotube around like a turning shaft.The gears would rotate best at about 100 billion turns per second or six trillion rpm, according to the study. The gears measure about a nanometer across. E-mail jbluck@mail.arc.nasa.gov

Artificial foot and knee designed jointly by U.S., Russian labs

A letter expressing "deepest gratitude" from a Russian landmine victim fitted with a newly developed artificial foot helps demonstrate one reason why a second prosthetic project between Sandia National Laboratories and the Ohio Willow Wood Co., Mount Sterling, OH, has begun. This one, to develop an artificial knee, is supported by a $1.4 million R&D agreement from the Department of Energy. Technologies for the foot and knee prostheses are being jointly developed by two nuclear weapons laboratories on opposite sides during the Cold War Sandia and the Russian lab Chelyabinsk 70 (Snezhinsk, Russia). The Russians will design a titanium housing, and Sandia robotic researchers will design the knee's internal workings and electronics. The two labs will split their half of the funding. Ohio Willow Wood, a producer of prostheses will define the requirements for the parts and perform final laboratory and clinical testing of the products. "This work will have many benefits," says Sandia chemist and project leader Mort Lieberman, who will manage the Russian connection. E-mail nsinger@sandia.gov   

Smart defrost controller lowers supermarket energy costs

Defrosting is one of the most energy-intensive processes in supermarket refrigeration systems. However, a new, smart controller for timing defrost cycles can cut energy use. The digital controller available from Johnson Controls/Encore has yielded large energy savings in field tests on both electric and hot-gas defrost systems. In smart (on-demand) defrosting, a defrost cycle starts only when required. Using a proprietary, patent-pending algorithm developed by EPRI, the science and technology center for electric utilities, the controller analyzes past defrost patterns for each refrigerated case to predict when the next cycle is needed. The algorithm is available as a software addition to the control system. A stand-alone version of the controller, scheduled for introduction this year, is expected to replace the mechanical timer controls now used in most of today's supermarket refrigeration systems. E-mail mkhattar@epri.com