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September 10, 2003

  In This Issue:
bullet Detecting Chemical Threats With "Intelligent" Networks
bullet From Movies to Minutia: DVDs Eyed for Archival Uses
bullet Software Opens the Door For Natural Ventilation
bullet Sensor Company Flies High With Extension Center Help
bullet Quick Links

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Micrograph of NIST sensor device

Micrograph of NIST sensor device used to detect toxic gases. Colors reflect slight variations in thickness of the sensing film. The suspended microhotplate in the center measures about 100 micro-meters square.

Detecting Chemical Threats With "Intelligent" Networks

Prototype microsensor arrays connected to artificial neural networks—computer models that “learn”—can reliably identify trace amounts of toxic gases in seconds, well before concentration levels become lethal, National Institute of Standards and Technology (NIST) scientists and a guest researcher reported Sept. 7 at the American Chemical Society annual meeting in New York City. The system has the potential to provide cost-effective early warning of chemical warfare agents.

Lab experiments show that the sensors, which use NIST-patented microheater technology, can detect compounds such as sulfur-mustard gas and nerve agents (tabun and sarin) at levels below 1 part per million. The neural networks, which currently run on a personal computer, were added recently to process signals from the sensor arrays. The networks enable the system to rapidly distinguish among the gases and predict their concentration in the ambient air.

The microheaters, which are coated with metal oxide films, can be programmed to cycle through a range of temperatures. Airborne chemicals attach to the film in characteristic ways depending on factors such as temperature and film material, causing changes in the flow of electricity through the microsensors. These changes serve as a “signature” for identifying both the type and concentration of the gas in the ambient air.

The neural networks were trained to detect subtle variations in these signatures. An array of four microheater sensors programmed to quickly sample 20 temperatures produces as much data as 80 different sensors.

Research is ongoing to more fully assess the impact of background interference as a means of avoiding false positives, and to enhance the robustness of the sensors with repeated use. The research is funded by NIST and the Defense Threat Reduction Agency.

Media Contact:
Laura Ost, (301) 975-4034


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From Movies to Minutia: DVDs Eyed for Archival Uses

The U.S. Geological Survey has compiled massive amounts of information about the Earth, and wants to hold on to it indefinitely. The National Archives is the official depository for information about the federal government and wants to protect its digital treasures.

However, before these government agencies and others start replacing their bulky paper files or compiling information on newer technologies like DVDs, they want to be sure that the new storage disks have staying power. Computer scientists at the National Institute of Standards and Technology (NIST) are launching an effort to develop specifications for “archival quality” CD and DVD media that agencies could use to ensure the procurement of sufficiently robust media for their long- term archiving needs (i.e., 50 years and longer).

NIST is spearheading the standards effort under the auspices of the Government Information Preservation Working Group, a newly formed group that includes representatives from a variety of agencies. The working group shares information and best practices concerning the use of DVD and related technologies in the federal government. It will identify the needs of the federal community in relation to the durability of storage media and work with industry to develop suitable archival grade specifications.

NIST has developed test and evaluation facilities that the group will use. The test facilities have systems that can rapidly assess disk quality by detecting flaws. Also included are enclosed chambers that use temperature and humidity changes to artificially age the media some 20 years in only six weeks.

Media Contact:
Phil Bulman,  (301) 975-5661Up


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Software Opens the Door For Natural Ventilation

A lack of rigorous design methods and comprehensive performance data has slowed U.S. acceptance of natural ventilation technology, which proponents argue can increase energy efficiency in commercial buildings as well as improve indoor environmental conditions. The National Institute of Standards and Technology’s (NIST) new LoopDA 1.0 software program (for Loop Design and Analysis) helps fill this critical information gap.

The LoopDA simulation tool enables building designers and engineers to determine the size of natural ventilation openings needed to provide desired airflow rates. Previously, building designers have had to make decisions using trial and error or based on past experiences. Although LoopDA 1.0 provides “first-cut” estimates rather than final results, it is a great improvement over the former “more art than science” approach, according to NIST developer Stuart Dols.

As described at a recent technical conference in the Netherlands* LoopDA allows users of the computer program to sketch rooms and vertical sections of a building, the location of natural ventilation openings (e.g., windows, doors and ducts) and the paths the air should take through the building (i.e., pressure loops). The program then enables designers to determine the size of the natural ventilation openings needed to control indoor air quality and thermal comfort using an engineering-based design process.

For more information on LoopDA 1.0 go to

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

*Steven J. Emmerich and W. Stuart Dols "LoopDA—A Natural Ventilation System Design and Analysis Tool" Proceedings, Building Simulation 2003 for Better Building Design Conference, Eindhoven, Netherlands, August 11-14, 2003.



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Sensor Company Flies High With Extension Center Help

Ascension Technology Corp. (ATC) manufactures high-tech motion tracking sensors that are helping to train military pilots to fly or guide doctors through delicate surgery faster and safer. Combined with 3-D computer graphics, motion trackers are revolutionizing areas such as animation, medical imaging and treatment, biomechanics, virtual reality, and military simulation and training.

ATC now has 40 employees but that wasn’t always the case. Founded in 1986, the Milton, Vt., company was struggling with excessive inventory levels and chronic parts shortages. In June 2002, ATC managers asked for help from the Vermont Manufacturing Extension Center, an affiliate of the National Institute of Standards and Technology’s (NIST) Manufacturing Extension Partnership. VMEC’s Manufacturing Business Advisors drafted a comprehensive improvement plan for the company including lean manufacturing initiatives, quality improvements and new inventory control and replenishment systems.

To date, ATC has cut the time to manufacture and ship from an average of 36 days to one to two days. As a result, the company has been able to increase its sales, save money, and create new jobs.

Media Contact:
Jan Kosko, (301) 975-2767



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Quick Links

Advanced Technology Awards—The National Institute of Standards and Technology has announced 44 new awards from its Advanced Technology Program (ATP). The funding will assist 35 companies and nine joint venture partnerships in developing novel technologies such as brain stimulation technology to reduce the likelihood of severe epileptic seizures, a computer network firewall that uses artificial intelligence, a low-cost system for fabricating electronic devices that are as thin and flexible as paper, and three-dimensional laser-scanning technology for faster and more reliable inspection of manufactured parts and products. The new awards represent a total of up to $104.5 million in ATP funding and an industry share of up to $74.5 million, if all projects are carried through to completion. For details see:

Building Investigations—The National Construction Safety Team (NCST) Advisory Committee, a panel of 10 building and fire experts who advise the NIST director on carrying out investigations of building failures conducted under the authorities of the NCST Act, met for the second time on Aug. 26-27, 2003. Presentations from that meeting are now available online that detail the status of NIST’s ongoing technical investigations of the Sept. 11, 2001, World Trade Center disaster and the Feb. 20, 2003, Rhode Island nightclub fire. Go to

Statistics for Everyone—The NIST/Sematech e-Handbook of Statistical Methods, which provides modern statistical techniques and updated case studies for non-experts who want to use statistical tools, is now available for free on CD-ROM. The CD-ROM complements the Web-based guide that came out in July 2002. To receive the CD version send a request to Remember to include your postal address (not just an e-mail address). The e-Handbook Web version may be found at

Network Security Workshop—A workshop on “Securing & Auditing Virtual Office Networks” will be held at the National Institute of Standards and Technology in Gaithersburg, Md., on Sept. 24-26. The workshop will explore authentication mechanisms, enterprise authentication systems, remote access server configuration, session-level encryption, virtual private networks, and wireless application security, among other topics. Go to:

Tissue Engineering Symposium—On Oct. 14-15, the National Institute of Standards and Technology will host a symposium in Gaithersburg, Md., on “Metrology and Standards for Cell Signaling: Impact on Tissue Engineering.” The meeting will identify advancements in measurements, reference materials and standards that will be required to foster understanding and control of cell response, as well as enable the development of new products and approaches for tissue engineering and regenerative medicine. Go to:

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Editor: Gail Porter

Date created: 09/10/03