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Web-based homeland defense course

Courseware developers at SwRI have developed a web-based course that provides awareness-level training for possible chemical, biological, nuclear or radiological threats from accidents or terrorism.

The course, developed with funding provided by the Institute's internal research program, can substitute for classroom-style instruction and can be taken by a client's employees using computers with Internet access, said Kevin Fiedler, manager within SwRI's Training, Simulation and Performance Improvement Division.

The course is intended to provide enough awareness so that the first people on the scene know how to recognize a threat and don't become victims themselves," Fiedler said. The first to encounter an event involving chemical, biological or radiological exposure likely may be a local law officer, firefighter, school nurse or utility worker, not a trained hazardous-materials technician or terrorism expert, he said.

Course content elements were provided by Signature Science LLC, an Austin-based subsidiary of SwRI that deals in homeland security training. The response protocol to observe, assess, plan, communicate and respond, was developed by Signature Science and is a part of the course.

See tspi.swri.org.

Scientists adjust view of unchanged comets

The long-held perspective that comets are pristine remnants from the formation of the solar system has evolved from the prevailing views of 30 years ago, planetary scientist Dr. S. Alan Stern has reported in a paper published in the journal Nature.

"It's fair to say that a sea change has taken place," said Stern, director of the Space Studies Department in SwRI's Space Science and Engineering Division. "We used to consider comets as wholly unchanged relics that had been stored ever since the era of solar system formation in a distant, cold, timeless deep freeze called the Oort cloud. We now appreciate that a variety of processes slowly modify comets during their storage there," he said. "As a result, it's become clear that the Oort cloud and its cousin the Kuiper Belt are not such perfect deep freezes."

The first evolutionary process to be recognized as affecting comets during their long storage was radiation damage, followed by the discovery that sandblasting from dust grains in the interstellar medium plays an important role. Next, researchers theorized that comets in the Oort cloud are heated to scientifically significant temperatures by passing stars and supernovae, according to Stern. More recently, researchers are finding that comets in the Kuiper Belt are heavily damaged by collisions.

"It also now seems inevitable that most comets from the Kuiper Belt, though constructed of ancient material, cannot themselves be ancient - instead they must be 'recently' created chips off larger Kuiper Belt Objects, formed as a result of violent impacts," said Stern. "This is truly a paradigm shift. Many of the short-period comets we see aren't even ancient."

The classical view that comets do not evolve while they are stored far from the Sun in the Oort cloud and Kuiper Belt began to change as far back as the 1970s, but the pace of discoveries about the way comets evolve picked up considerably in the 1980s and 1990s.

As a result of these findings, astronomers now better appreciate that comets, though still the most pristine bodies known, have been modified in several important ways since their birth, said Stern. That realization provides insight and context to more confidently evaluate the results of astronomical and space mission observations of comets. So, too, it suggests that cometary sample return missions now on the drawing board for NASA should employ relatively deep subsurface sampling if truly pristine, ancient material is to be collected.

For more information, contact Hal Levison.

SwRI offers services for manufacturers and suppliers of small engines

SwRI has expanded its capabilities in engine design, testing and optimization of small spark-ignited and diesel engines, including those used in motorcycles, all-terrain vehicles, snowmobiles, personal watercraft and other utility vehicles.

Additional services include emissions testing, durability testing, component analyses and other capabilities, from concept to production.

SwRI has added four dedicated small-engine dynamometer test stands and plans to double that number by 2004. Other test facilities include an eddy-current motorcycle chassis dynamometer, a full exhaust dilution tunnel, data acquisition and control systems, high-speed test cell computers, a high-speed combustion measurement system, engine dynamometers, an ATV chassis dynamometer, and a motorcycle teardown and inspection facility.

In addition, SwRI also performs combustion visualization, detailed airflow analysis, combustion bomb testing, and competitive engine and vehicle benchmarking.

Sunlight affects asteroids' spin

A new study by researchers at Southwest Research Institute and Charles University in Prague has found that sunlight can have surprisingly important effects on the spins of small asteroids. The study indicates that sunlight may play a more important role in determining asteroid spin rates than collisions, which were previously thought to control asteroid spin rates. Results were published in the Sept. 11 issue of Nature.

David Vokrouhlicky (Charles University), David Nesvorny and William Bottke (both of the SwRI Space Studies Department in Boulder, Colo.) conducted the study, which showed that sunlight absorbed and re-emitted over millions to billions of years can spin some asteroids so fast they could potentially break apart. In other cases, it can nearly stop them from spinning altogether. The team even noted that the effects of sunlight, combined with the gravitational tugs of the planets, can slowly force asteroid rotation poles to point in the same direction.

Until recently, researchers thought asteroid impacts controlled the rotation speed and direction of small asteroids floating in space. The unusual spin states of 10 asteroids observed by Stephen Slivan, a researcher at the Massachusetts Institute of Technology, however, have cast doubt on this idea. Slivan's asteroids, the first in the 15- to 25-mile-diameter range to have their spins extensively studied, are in the so-called Koronis asteroid family, a cluster of asteroid fragments produced by a highly energetic collision billions of years ago. Slivan found that not only do four of these asteroids rotate at nearly the same speed, but they also have spin axes that point in the same direction.

"The data clearly show that the spin vector alignment is real, but how they got that way has been a big puzzle," Slivan said. "I'm delighted that others find this to be an interesting problem."

The remaining six asteroids studied by Slivan either have extremely slow spin rates, such that they rotate slower than the hour hand of a clock, or very fast spin rates, such that they are near the limit beyond which loose material on the surface of an asteroid would fly off.

"One would expect that collisions would have randomized these rotation rates. It was a big surprise to find a cluster of asteroids with such odd spin states," said Nesvorny.

To explain the spin states of Koronis family asteroids, Vokrouhlicky, Nesvorny and Bottke investigated how asteroids reflect and absorb light from the Sun and reradiate this energy away as heat. They found that while the recoil force produced by the reradiation of sunlight is tiny, it can still substantially alter an asteroid's rotation rate and pole direction if it has enough time to act.

Using computer simulations, the team showed that sunlight has been slowly increasing and decreasing the rotation rates of Koronis family asteroids since they were formed 2 to 3 billion years ago. More remarkably, they found that some simulated asteroids were captured into a special spin state that forced the wobble of the asteroid's spin axis (produced by gravitational perturbations from the Sun) to "beat" at the same frequency as the wobble of the asteroid's orbit (produced by gravitational perturbations from the planets). This state, called a spin-orbit resonance, can drive an asteroid's rotation rate and spin axis to particular values.

NASA, the National Research Council and the Grant Agency of the Czech Republic funded the study.

Contact Nesvorny at (303) 546-9670 or david.nesvorny@swri.org.

Groff promoted to senior vice president of SwRI Office of Automotive Engineering

Walter P. Groff has been promoted to senior vice president at Southwest Research Institute and will head the new Office of Automotive Engineering. SwRI's divisions of Engine, Emissions and Vehicle Research, and Fuels and Lubricants Research will report to this office. Groff will also serve as acting vice president of the Fuels and Lubricants Research Division.

Groff, who was named vice president of the Automotive Products and Emissions Research Division in 1998, began his career at SwRI 34 years ago in the areas of standard and specialized engine, fuel and lubricant testing. He has extensive experience in specialized engine dynamometer tests related to lubricant performance and engine component durability in gasoline, diesel, natural gas and alcohol-fueled engines.

He was instrumental in the design of one of the first repeatable fired engine dynamometer test procedures to measure the frictional characteristics of motor oils and has developed several "screener" test procedures to predict an oil's performance under standard American Society for Testing and Materials (ASTM) procedures.

In his new position, Groff will be responsible for two divisions that account for almost one-third of SwRI's technical staff and research revenues.

"The new organization will target a more unified effort of this sector of our business, optimize existing resources and help us better meet the needs of our clients," SwRI President J. Dan Bates said.

Groff holds a bachelor's degree in industrial technology from Texas A&M University. He is a member of the ASTM and the Society of Automotive Engineers.

Published in the Fall 2003 issue of Technology Today®, published by Southwest Research Institute. For more information, contact Joe Fohn.

Fall 2003 Technology Today
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