In This Issue: Trapping Neutrons May Capture Bigger Prize-Peek at Big Bang Using One Voice for Software Testing Creates Harmony for All From Chocolate to Heart Proteins: NIST Sets the Standards Smile! New NIST Amalgam Material Contains No Mercury A Laser Ruler for Paint Films Neutrons Chart Smooth Ride for Automotive Springs Tech Trivia
When you see the camera icon, click to see available picture !
[NIST Tech Beat Search] [Credits] [NIST Tech Beat Archives] [Media Contacts] [Subscription Information]
Trapping Neutrons May Capture Bigger Prize-Peek at Big Bang
What really happened at the beginning of time? It's a question that's long fascinated humanity, and now a new achievement at the National Institute of Standards and Technology may yield more clues.
For the first time ever, scientists have confined neutrons, one of the basic particles of matter, in a three-dimensional magnetic trap. Researchers from NIST, the Department of Energy's Los Alamos National Laboratory, the Hahn-Meitner Institute and Harvard University (lead institute) report this work in the Nature issue of Jan. 6, 2000. The ability to trap neutrons will allow scientists to improve measurements of the neutron lifetime, an important value for modeling the beginning of our universe.
In the moments after the Big Bang, fundamental particles coalesced into neutrons and protons. These particles in turn started to combine to form helium and other light elements. Meanwhile, free neutrons began to decay. The time it took for the free neutrons to completely decay-about 15 minutes-has helped researchers determine the initial ratio and concentration of light elements in the universe. A more accurate neutron lifetime will improve the understanding of how fundamental particles formed all matter.
Linda Joy , (301) 975-4403
Using One Voice for Software Testing Creates Harmony for All
Most of us can share horror stories about flawed computer programs, but our descriptions of each experience would probably differ greatly. While that's OK for individuals, companies that make major expenditures on software need more specific and comparable information about how that software performed for others.
Testing of business software by companies generates information about the qualities that make programs easy to use, such as effectiveness, efficiency and customer satisfaction. Computer scientists at the National Institute of Standards and Technology have launched a project to encourage software "usability." The goal is to standardize how companies report their software testing and see how helpful the "common format" data is for potential purchasers.
If successful, standardization of user testing could save firms millions of dollars by reducing the lost productivity and huge training costs associated with buying software that is either poorly designed or simply inappropriate for a specific task. Participants in the project include many of the country's largest software producers and buyers: Compaq Computer Corp., Hewlett-Packard Co., Microsoft Corp., Sun Microsystems Inc., Boeing Co., Eastman Kodak Co., Fidelity Investments and State Farm Insurance Co.
Philip Bulman , (301) 975-5661
From Chocolate to Heart Proteins: NIST Sets the Standards
What do spinach leaves, whale blubber, pine needles and industrial sludge have in common?
No, they're not the ingredients of some haute cuisine salad. These materials are among the nearly 1,300 that the National Institute of Standards and Technology has characterized for specific physical and chemical properties using state-of-the-art measurement methods. Known as Standard Reference Materials, these certified artifacts are used by industry, academia and governments to establish the quality and reliability of devices, goods, medical data and scientific results.
Based on the latest needs of NIST customers, an interesting collection of new measurement references have been proposed for development and certification in the years 2000-2001. For example, plans call for an SRM of fired bullets and casings with defined ballistic "fingerprints" to validate the results of automated systems that connect firearms to specific crimes. Another will help assure the accuracy of quicker heart attack diagnoses through the measurement of Troponin I, a protein released into the bloodstream early in the event. A third, the chocolate SRM, will help assure consumers that foods containing high percentages of fats and carbohydrates really contain the nutritional composition listed on the label.
And if those aren't compelling enough, how about SRMs for additives in smokeless gunpowder, antibiotics in milk, abrasiveness of toothpaste, inorganic and organic contaminants in Lake Superior and Lake Michigan fish tissue, and organic contaminants in household dust.
Linda Joy , (301) 975-4403
Smile! New NIST Amalgam Material Contains No Mercury
If you have a metallic dental filling, you probably have a small amount of mercury in your mouth. For decades, U.S. dentists have used alloys containing copper, tin, silver, zinc and mercury in amalgams. Such alloys are ideally suited to the job. They're long-lasting, strong, corrosion-resistant and bond easily to tooth enamel. However, concern over the toxicity of mercury has prompted discussion about restricting their use.
Until now, there were no replacement materials that worked as well. Metallurgists at the National Institute of Standards and Technology have perfected a method for making silver powder that, when properly consolidated, has properties that equal or exceed those of mercury-containing alloys. The powder is precipitated from a solution and then treated with a dilute acid to remove silver oxide from the surface of the very small silver particles. These particles then can be compacted carefully with normal dental tools into a tooth cavity where they consolidate through cold welding. Fillings made this way are 80 percent dense and are at least as strong as mercury-alloy amalgams.
NIST is inviting companies to apply to license the patented process by contacting Terry Lynch at (301) 975-2691.
Linda Joy , (301) 975-4403
A Laser Ruler for Paint Films
A new laser-based measurement technology, developed by the Autospect T Division of Perceptron Corp. with cost-shared funding from the National Institute of Standards and Technology's Advanced Technology Program, may solve a long-vexing problem on auto assembly lines-measuring the thickness of paint.
There are many variables (such as temperature and fluid flow) that affect the application of paint to auto bodies. But manufacturers cannot make the process more efficient until they can measure how much paint is actually on the car.
Currently, such measurements are made after several layers of paint have been sprayed and dried. Manufacturers can assess about two cars a day with some 250 individual measurements per car. This means only a fraction of a percent of production can be checked, far too slow to gather enough process-control data. By the time a problem is uncovered, it already has affected hundreds of car bodies.
Autospect believes the answer is a non-contact, non-destructive probe using "laser ultrasonics." A short, intense burst of laser light heats a small area of paint, setting up an ultrasonic wave in the film. This rings like a bell-the thicker the film, the lower the frequency. A second laser beam is reflected from the paint surface, its frequency subtly shifted by the wave.
With this technique, Autospect engineers expect to make 100 measurements per second per 100 cars under production conditions. Their current task is to verify the accuracy of the system.
Michael Baum , (301) 975-2763
Neutrons Chart Smooth Ride for Automotive Springs
Automakers go to great lengths to make sure their suspension springs hold up under pressure. Ford Motor Co.'s quest for the smoothest and most reliable suspension system brought it to the National Institute of Standards and Technology's Center for Neutron Research. NIST was asked to study whether a new process for making springs left residual stresses that were consistent with accepted theoretical models.
What they found was that, although the models developed in the 1950s did not fully consider the residual stresses after coiling the springs cold and then relieving stress with moderate heat, these stresses were at a manageable level. Ford is using cold-coiling alongside the more traditional method of hot-coiling.
NIST researchers measured the residual stress with a special neutron diffractometer, using highly penetrating neutrons to probe interatomic distances in metals or other crystalline materials. In the case of Ford's springs, NIST assessed residual stress in three dimensions.
NIST also determined the smallest segment that can be cut from the spring, yet still retain stresses present in the uncut spring. This allows Ford to check springs for residual stress using X-ray diffraction. Although limited to surface stress measurements, this technique can be used on the factory floor.
Linda Joy , (301) 975-4403
In 1968, NIST proposed a government standard for computer dates with a four-digit year. Other federal agencies preferred a two-digit code to save memory and data entry time. The final standard featured a two-digit code first option and a four-digit second. Nearly 20 years later, the Y2K computer problem-caused by two-digit codes-was first predicted.
From Feb. 25-Dec. 30, 1999, NIST's Y2K Help Center for Small Businesses reported nearly 8,000 calls, some 61,000 visits to its web site and just over 30,000 downloads of its Self-Help Tool software. From Dec. 30, 1999- Jan. 7, 2000 (with the center open 24 hours each day), the numbers were 150; 1,922; and 155, respectively.
The average hits per day on the joint NIST/U.S. Naval Observa-tory web site, www.time.gov (with a time readout for each U.S. time zone accurate to within 0.2 seconds), increased sixfold from 50,000 to 300,000 during the New Year's Day 2000 weekend.