Technology at a Glance is a quarterly newsletter from the National Institute of Standards and Technology reporting on research results, funding programs, and manufacturing extension and technology services. If you have comments or general questions about this newsletter or if you would like to receive the four-page, color newsletter in hard copy, please email your mailing address to Gail Porter, editor, or call (301) 975-3392. About Technology at a Glance.

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Best in the World Clock Debuts

NIST has a new, improved atomic clock. The new NIST fountain clock, or NIST-F1, shares the distinction of being the most accurate clock in the world with a similar device in Paris.

Three times more accurate than the previous U.S. time standard NIST-7, the new clock is so accurate that it will neither gain nor lose a second in nearly 20 million years.

Data from NIST-F1 now are contributing to improved accuracy for Coordinated Universal Time (UTC), the world's official time. Extremely accurate timekeeping is critical for Earth and space navigation, telecommunications, cutting-edge research, electronic financial transactions, and many other activities.

F1's improved accuracy stems from a better measurement of the "resonance frequency" for cesium. This frequency, within the microwave range of the electromagnetic spectrum, is used in the international definition of the second. One second equals the time it takes for 9,192,631,770 wavelengths of energy at the resonance frequency of cesium to pass a given point. A resonance frequency is directly related to the amount of energy needed to raise an atom from one energy state to another.

The new clock determines cesium's resonance frequency more accurately by slowing the atoms down, thus removing errors from the measurement. NIST-7 fires cesium atoms through a micro-wave cavity at high speed and records the frequency that changes the most atoms to a higher energy state. The new clock uses the same basic concept but slows down the atoms to minimize the measurement distortion that would be caused by Doppler effects-the phenomenon that makes a train whistle sound lower in pitch as it moves away from you.

NIST-F1 slows down cesium atoms with six intersecting laser beams that push the atoms into a ball-shaped cloud and cool them to temperatures near absolute zero. The atom ball then is tossed gently up through a microwave cavity. The ball travels about a meter upward and then falls back through the cavity. Laser light is shined on the atoms and those that have absorbed microwaves and changed energy levels emit light that is measured with a detector. The microwave frequency is changed slightly and the process is repeated many times until the light emitted is maximized. The process is similar to tuning a radio dial until the strongest signal is received.

Contact: Tom Parker, tparker@boulder.nist.gov, (303) 497-7881.

Making Car Engines the 21st-Century Way

One day soon the ubiquitous, gas-guzzling sport utility vehicle may become a leaner, cleaner machine. The reason behind this transformation could well be a thick, brightly colored plastic putty, shoved into the intake manifold during the engine manufacturing process.

This special abrasive goo (technically a viscoelastic media impregnated with grit) is made for smoothing and shaping cast airway passages by Extrude Hone, a small Irwin, Pa., company. The technology increases the functional precision of cast-metal parts, thereby enhancing combustion efficiency. Combined with a similar treatment for manufacturing combustion chambers, Extrude Hone's machined parts can boost an engine's performance by up to 6 percent.

Until recently, only low-volume, high-value parts (for aircraft engines and specialty cars) were made this way, because the laborious, multi-step process involved repeated machining and testing of parts until the desired performance level was reached. Now the process has been streamlined and given the machine equivalent of a brain, opening the door to mass-market applications.

Development of the advanced process control system, which measures the flow characteristics of a part as it is machined, was made possible by support from NIST's Advanced Technology Program, matched by co-funding by Extrude Hone and its joint venture partners. The extent of machining required is determined by a neural network model-a computer architecture modeled on the brain's interconnected system of neurons-which correlates media flow with after-machining measurements of air flow. A laboratory prototype machine to perform this process was built and run on 5,000 intake manifolds, and the increase in functional performance was measured by running numerous tests on engines fitted with the new manifolds.

The process likely will be applied by the auto industry first to sport-utility vehicles and other light-truck classes of autos, which are most in demand and most affected by fuel-efficiency requirements, according to a recent ATP economic study (see www.atp.nist.gov/eao/
ir-6373.pdf). If the new technology is adopted as expected, the study says that within five years it should increase the annual gross domestic product by $142 million, annual personal income by $196 million, and annual tax revenues by $34 million, while creating 1,800 new manufacturing jobs.

Contact: Ralph Resnick, ralphr@extrudehone.com, (724) 863-5900.

Smokeview: Best Show Yet for Fire

Now showing on a PC near you is the best show yet from NIST fire modeling experts-two new software programs that together can visually recreate a blaze and graphically depict the spread and intensity of its deadly gases.

The Fire Dynamics Simulator solves numerical equations to model the movement of smoke and hot gases from a fire, predicting gas temperatures, heat fluxes, gas velocities, and sprinkler activation times. The information is visualized with Smokeview, written with the programming language that is commonly used to make video games. Based on three-dimensional arrays of numbers produced by the FDS, Smokeview's animations of colored particles depict the movement and temperature of the gases emanating from the fire, rendering volumes, slices, or other selected aspects. [A kitchen fire is depicted in the graphic above.] The program is the latest and most sophisticated of NIST fire models because it reveals flow patterns instead of averages, offering greater precision and detail regarding the movement of gases.

The programs were developed by NIST Building and Fire Research Laboratory engineers, who expect FDS and Smokeview to be used worldwide by both fire investigators looking into why a fire behaved in a specific way and builders or architects who want to know how detection equipment will react to fires. The programs can be downloaded free of charge from www.fire.nist.gov/fds.

Contact: Glenn Forney, (301) 975-2313.

Neutrons and the Beginning of Time

Neutrons, which typically move thousands of meters per second at room temperature, have been slowed to about one-thousandth of this speed-slow enough to be magnetically "trapped"-at the NIST Center for Neutron Research.

The implications of the research are far-reaching, extending back, literally, to the beginning of time. The ability to trap neutrons should allow scientists to improve measurements of the neutron lifetime, an important value for modeling the beginning of the universe.

Among the basic particles of matter, neutrons have been confined before, but this experiment, reported earlier this year in the journal Nature, featured a novel approach. The neutrons were slowed to velocities of a few meters per second in a liquid helium bath-slow enough to prevent their escape from a three-dimensional magnetic trap. Although neutrons have no net charge, they act like tiny bar magnets, which can point their spins either parallel or anti-parallel to the magnetic field. The scientists created a magnetic field geometry, which contained the neutrons with spin parallel to the field. The graphic shows a cross-section of the magnetic field, with red representing the highest strength, and blue, the lowest.

Scientists from NIST participated in the research, which was led by Harvard University and also included researchers from the Department of Energy's Los Alamos National Laboratory and the Hahn-Meitner Institute.

Contact: Paul Huffman, (301) 975-6465.

Helping Concrete Go with the Flow

A $50 billion industry, concrete is the most commonly used building material. But for something so ubiquitous, building researchers still have a lot to learn about how to optimize the performance of concrete for specific types of jobs. For example, fresh concrete should flow smoothly for easy placement, without sacrificing strength and durability when hardened. With partial funding from Boral Material Technologies and in collaboration with Master Builders Technologies and a committee of the American Concrete Institute, NIST researchers are studying factors affecting the flow of concrete.

The basic method for gauging concrete flow has remained essentially unchanged for a century. A standard cone-shaped mold is filled with concrete and then the mold is removed. As the concrete spreads under its own weight, its "slump" is measured. To help develop better instruments for such tests, NIST researchers have begun simulating how concrete flows using computer models that take into account the ratio of water to cement, the amount and sizes of rocks and sand grains, and the presence of chemicals like "superplasticizers" that improve flow. This information then is used to help explain the flow behavior of different concrete mixtures in the laboratory. NIST researchers hope their results will provide a predictive tool for optimizing concrete mixtures for specific applications.

The graphic to the right is a single frame from a video simulating the flow of concrete between two walls. In this example, forces are being applied to the right along the top and to the left along the bottom, placing the concrete under shear. Various colors are used to represent rock particles of different sizes. The NIST computer models used for these concrete flow simulations also may be applicable for studying the flow of other complex fluids such as polymer blends.

Contact: Nicos Martys, (301) 975-5915.

Simulations Look and Feel Real

Candy Is More Dandy When the Shipper Is Quicker

A popular product can be a bane as well as a boon for a small business. Just ask Marich Confectionery of Hollister, Calif., which produces and ships nearly 4 million pounds of gourmet candies worldwide. The 37-employee company had trouble keeping up with demand, and shipping on time was a major problem. The candy maker's efficiency was slowed by employee morale issues and by difficulties in maintaining a sufficient supply of raw materials and controlling finished products. So Marich contacted Manex, the northern California center affiliated with the NIST Manufacturing Extension Partnership. Working with company executives and employees, Manex experts recommended a process improvement plan and a new manufacturing layout. Manex also showed the company how to use flow charts for scheduling, material planning and purchasing, and controlling inventory. As a result, shipments are now made on time and in full, and employee morale and productivity have improved.

Contact: Robert Johnson, robert@manex.org, (510) 249-1480.

Fighting Crime with Gunpowder Analysis

Law enforcement agencies are getting some new scientific tools that are expected to help obtain more courtroom convictions in bombing and handgun crimes. NIST chemists, in conjunction with the National Institute of Justice, have come up with a rational basis for associating samples of unfired gunpowder or ammunition with handgun or pipe bomb residues. Chemists collected residues from handguns fired at a test firing range and analyzed nitroglycerin and stabilizer additives. They also developed a numerical identification ratio for linking residues to unfired powders. In another project, NIST is asking 13 forensic labs to analyze test samples of two commercial gunpowders. This voluntary interlaboratory comparison is designed to demonstrate their proficiency in gunpowder measurements, thereby making forensic gunpowder analysis more defensible in criminal prosecutions. These efforts will help forensic laboratories keep pace with a growing number of gunshot and explosives residue analyses.

Contact: Bill MacCrehan, (301) 975-3122.

Match-Making Software Will Help Finger Criminals

Smudged and partial fingerprints found at crime scenes will be easier to match to convicted criminals and fugitives thanks to new software developed by NIST and the Federal Bureau of Investigation. Until now, it has been impossible to match poor-quality crime scene fingerprints electronically with prints in the FBI database of convicts and fugitives. The new computer program enhances low-quality fingerprints for electronic matching and makes it possible to search the entire database, instead of only part of it. Additionally, it allows police departments in different states to exchange fingerprint information directly, instead of working through a national database. Law enforcement agencies around the country are testing the new software, the latest in a 30-year series of NIST/FBI efforts to enhance and automate the very laborious process of fingerprint analysis.

Contact: Michael Garris, (301) 975-2928.

Tell It to Your PC, Doc

Many physicians now find it easy and productive to enter patient data directly into computers, thanks to software developed by VitalWorks of Waltham, Mass., with support from NIST's Advanced Technology Program. The company adapted an existing note-writing system to capture clinical data automatically through a pleasing user interface. Combining medical expertise and computational linguistics, VitalWorks researchers wrote software algorithms to codify the patient data and developed a specialized knowledge base to support data collection and text generation. As a result, a physician can select just a couple of terms and the system produces a grammatical sentence; it also integrates the substance of the clinical note into a database suitable for research. The system reduces errors of omission in clinical notes, from an average of 22 percent of notes in one study to an average of 8 percent, and as few as 1 percent in certain cases.

Contact: Richard Johannes, (781) 788-4825, no e-mail available.

Smooth Ride—In its quest to produce the smoothest and most reliable suspension system, Ford Motor Co. asked the NIST Center for Neutron Research to study whether a new process for making springs-cold-coiling-left residual stresses consistent with well-established theoretical models. NIST researchers used highly penetrating neutron radiation to probe the interatomic distances in several prototype springs. From the variations in these distances, they derived the residual stress field contained within the springs. They found that the residual stresses were at a manageable level and commensurate with the theoretical models. NIST also performed research that will enable Ford to check for residual stress on the factory floor.

Contact: Paul Brand, (301) 975-5072.

Sulfur Standards—NIST measurement standards for sulfur in fossil fuels have saved the fossil fuel industry $113 for every dollar NIST spent on their development, according to a new economic impact study prepared for NIST by the Research Triangle Institute. The standards program, in operation since 1984, has produced a net value to society of more than $409 million while also generating more than $78 million in environmental benefits. Fossil fuel producers and their industrial customers use the NIST standards to verify the accuracy of their measurements of sulfur in coal and petroleum products.

The study is available online at www.nist.gov/director/prog-ofc/report00-1.pdf.

For a paper copy, e-mail dherbert@ nist.gov.

Lean Manufacturing—Thanks to a partnership between centers in NIST's Manufacturing Extension Partnership's nationwide network and Productivity Inc., small manufacturing firms now have access to a new training course in the "lean enterprise" series. The lean enterprise approach eliminates manufacturing activities or actions that add no real value to the product or service. Field manufacturing specialists at MEP centers will receive training in Productivity's course on "The 5S System," previously available only to large manufacturers, which teaches plant managers how to apply the five "pillars" of workplace organization and standardization: sort, set in order, shine, standardize, and sustain.

Contact: Maria Elena Stopher, (301) 975-5106.

Small manufacturers in all 50 states, the District of Columbia, and Puerto Rico can reach their local NIST MEP affiliate by calling (800) MEP-4MFG (637-4634).

About Technology at a Glance:

NIST is an agency of the U.S. Department of Commerce's Technology Administration. NIST promotes US economic growth by working with industry to develop and apply technology, measurements, and standards. Technology at a Glance is produced by Public and Business Affairs, NIST, 100 Bureau Dr., Stop 3460, Gaithersburg, Md. 20899-3460. Any mention of commercial products is for information only; it does not imply recommendation or endorsement by NIST. Technology at a Glance Editor: Gail Porter, (301) 975-3392, email: gail.porter@nist.gov. For patent information, call (301) 975-3084.

Technology at a Glance Archive Files

Last updated: 6/12/2000
Susan Ford