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March/April 2002

In This Issue:
bullet NIST Creates ‘Magic’ Bullets (and Casings) Against Crime
bullet Video Illustrates Impact of Sprinklers on Dorm Room Fires
bullet ‘Cutting’-Edge Technology to Better Shape Submarine Propellers
bullet New Tool Promises Better Predictions of Gas Impacts
bullet New Standards from NIST May Provide ‘All-Natural’ Benefits
bullet New NIST Procedure Seeks Improved Diagnosis of Fragile X Syndrome
bullet Tech Trivia

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Law Enforcement

NIST Creates ‘Magic’ Bullets (and Casings) Against Crime

Two robberies take place at different sites in New York City a few days apart. Police suspect that the same person is responsible but only have small pieces of evidence with which to make the link: bullets and casings found at the two locations. Thanks to new “standard bullets and casings” from the National Institute of Standards and Technology (NIST), any forensic scientist trying to match these bullets and casings could be confident with his or her results.

Ballistic evidence is considered valuable because each gun’s firing pin and ejection mechanism imparts distinctive markings—known as “signatures”—on fired bullets and ejected casings. The computerized optical-imaging instruments used to examine these signatures must be calibrated for accuracy.

To provide the tools needed to do the critical calibrations, NIST has manufactured standard bullets—known as NIST Reference Material (RM) 8240—and standard casings—known as NIST RM 8250—with identical signatures. The signatures on each bullet and casing RM created by NIST are exactly the same as those on every other corresponding artifact in the two series. Quality bullets previously used in forensic laboratories were produced by a standardized shooting procedure and, therefore, exhibited minute changes in signatures over time due to gun wear and environmental conditions.

NIST researchers also are working on a “virtual” or digital bullet signature standard that crime laboratory personnel can access with their computer from the national laboratory center at the Bureau of Alcohol, Tobacco and Firearms (ATF) and the Federal Bureau of Investigation (FBI).

Media Contact:
John Blair,  (301) 975-4261Up



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Fire Research

Video Illustrates Impact of Sprinklers on Dorm Room Fires

It may not be the MTV version of “Burnin’ Down the House” by the Talking Heads, but a new fire research video from the National Institute of Standards and Technology (NIST) promises to be a hot item anyway—that is, with those concerned with fire safety in dormitories.

The nine-minute video of recent test fires in two scheduled-for-demolition University of Arkansas dormitory rooms taken by in-room cameras dramatically demonstrates how effective sprinklers can be in controlling fires in this type of environment.

Two fully furnished dormitory rooms are depicted in the video, one with and one without sprinklers. A fire is ignited in the wastebasket in each room. In the dormitory room with the sprinklers, the devices activated in under two minutes and extinguished the fire. In the room without fire extinguishing equipment, the blaze reached “flashover” conditions (when all combustibles in a room burst into flames and the fire spreads rapidly) in less than six minutes.

The video also includes post-fire photographs, which can be used to compare the damage caused by each fire.

The college dormitory experiments were sponsored by the U.S. Fire Administration.

This video should prove to be an effective education tool. For a free VHS copy, send a request to NIST’s Nelson Bryner by fax at (301) 975-4052 or by e-mail to

Media Contact:
John Blair,  (301) 975-4261Up


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‘Cutting’-Edge Technology to Better Shape Submarine Propellers

Super smooth propellers of maximum structural integrity allow submarines to run silently in deep water. These nickel-aluminum-bronze alloy propulsion units take as long as 12 months to manufacture—a production time that the US Navy feels is too long. So, National Institute of Standards and Technology (NIST) high-speed machining experts are working with the US Navy and the University of North Carolina at Charlotte (UNCC) on a new machine tool and special metal-cutting strategies to decrease that time to four months.

A submarine propeller begins life as a greater than six-meter (20-foot) diameter, 50,000-kilogram (55-ton) metal casting. It must be machined down to a mass near 37,000 kilograms (41 tons) in its final form. Current machining methods leave the propeller with a rough surface, which if left unchanged, would betray a submarine’s movements in the ocean. So, months of hand finishing are required.

“Such a time-consuming process may soon be a thing of the past,” said Tony Schmitz, a NIST engineer working on the project. “NIST’s tool wear and surface finishing experiments have led to a better understanding of the required parameters for high-speed machining of the propeller alloy. These discoveries have enabled us to increase the material removal rate during machining by a factor of 10. Additionally, refinements in the paths that the tool follows during metal cutting promise to substantially reduce roughness in the final milled propeller surface.”

Media Contact:
John Blair,  (301) 975-4261Up


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New Tool Promises Better Predictions of Gas Impacts

The potential environmental impact of new fire suppressants and other gaseous compounds, from refrigerants to industrial solvents, can be estimated much faster now than ever before—in hours instead of months—thanks to a computational tool developed by the National Institute of Standards and Technology (NIST).

The new tool reliably estimates a compound’s atmospheric lifetime (i.e., how long it lasts before breaking down), the starting point in calculating the potential contribution to stratospheric ozone depletion and global warming. Until now, laborious and costly laboratory measurements were required to assess new classes of compounds, such as environmentally safe replacements for the halons long used as fire suppressants. The new approach, which relies on several existing software programs, overcomes past difficulties in correlating chemical structure and reactivity.

The computational tool is based on several years of theoretical work involving quantum mechanical calculations. NIST researchers made calculations at three levels of theory for a large set of chemical reactions for which the reaction rates were well known. An optimal level of theory was found that matched experimental results closely enough to be considered reliable—and was frugal in its use of computational resources. This may make routine use of the tool practical.

The tool has been used to screen potential fire suppressants and already has identified one with a short atmospheric lifetime, making it a candidate for further study. Efforts are continuing to enhance and further simplify the computations.

Media Contact:
Michael E. Newman,  (301) 975-3025



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New Standards from NIST May Provide ‘All-Natural’ Benefits

A new National Institute of Standards and Technology (NIST) effort to develop standard reference materials (SRMs) for a number of popular botanical dietary supplements will provide tools that manufacturers can use to improve quality control during production, that researchers can use to ensure that their laboratory analyses of test substances are accurate, and that the Food and Drug Administration (FDA) can use in monitoring marketed products and, when appropriate, in enforcement actions. Ultimately, consumers benefit because these efforts will ensure that marketed products contain what they are supposed to contain.

NIST was asked to develop the standards by the National Institutes of Health (NIH) Office of Dietary Supplements and the FDA, which are providing partial funding for the project.

NIST will certify the concentrations of designated constituents in botanical ingredients and finished product preparations. The standards development program will begin with botanical sources of ephedrine alkaloids and kava, two widely marketed ingredients in dietary supplement products. Additional SRMs for nutriceuticals (nutritional supplements designed for specific clinical purposes) to be provided by NIST will be determined based on priorities provided by the NIH and FDA.

Information about ephedra, kava and other dietary supplements can be found at and

Media Contact:
Michael E. Newman,  (301) 975-3025Up


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New NIST Procedure Seeks Improved Diagnosis of Fragile X Syndrome

A robust protocol for measuring a specific class of genetic elements called “trinucleotide repeats” has been optimized at the National Institute of Standards and Technology (NIST) to help clinical laboratories accurately identify Fragile X syndrome, the most common cause of inherited mental retardation. The research is part of a NIST effort to develop standards for measuring the expansion of these trinucleotide repeats. The NIST protocol responds to the guidelines recently issued by the American College of Medical Genetics, which recognized that Fragile X is one of the most frequently ordered genetic tests and that there are many testing methods with different strengths and weaknesses.

Fragile X syndrome results from the repetition of a particular sequence of three chemical units on the X chromosome. About 30 repeats is normal; higher numbers, especially in the range of 60 to 200, indicate an unstable “premutation” repeat length. As the number of repeats increases in successive generations, the production of a certain protein is shut off and symptoms of the disease appear or become more severe. Thus, accurate measurement of the size of the affected region of the chromosome is important as a diagnostic indicator of the disease and likelihood in future generations.

Current methods become less reliable when the number of repeats exceeds 100. The NIST protocol establishes specific conditions for the creation of multiple copies of the genetic material and their analysis. NIST initially focused on repeat sizes of about 30 to110; future work will assess methods for measuring larger repeat elements.

Media Contact:
Michael E. Newman,  (301) 975-3025Up


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Tech Trivia

It was a bit of déjà vu when the National Institute of Standards and Technology (NIST) recently partnered with the US Army to standardize a testing procedure for gas masks to ensure that they will protect soldiers against chemical or biological agents. During World War II, NIST designed a simple, bellows-driven device that enabled pilots to test their own oxygen masks for leaks.

Another NIST project during the Second World War suggested that you could not only capture flies with sugar, but Axis fortifications as well. At the request of the Army Intelligence Branch, NIST searched for a readily available material, which when added in small amounts to concrete behind enemy lines, would sabotage the strength of structures made from it. Common sugar proved the most effective agent—working at concentrations as low as one part in a hundred.

Lights visible to the enemy made the reading of maps at night hazardous for Allied soldiers during World War II. To reduce the hazard, the War Department printed maps on fluorescent paper that could be read under invisible ultraviolet light. Standards for brightness and chromaticity (color purity) for these papers were developed by NIST researchers, whose expertise had been gained from measuring the properties of some 5,500 specimens of luminescent materials evaluated for the war effort.

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Editor: Michael E. Newman

Date created: 4/19/02