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July 26, 2005

  In This Issue:
bullet Researchers Help Sort Out the Carbon Nanotube Problem

Bioagent Detector Guide Aids First Responder Purchasing

bullet Compact JILA System Stabilizes Laser Frequency
bullet Comments Sought on Draft Federal IT Security Standard
  Quick Links:
bullet Measurement Challenges In Detecting Cancer Biomarkers
bullet Draft Guidelines Released for IT Security Controls
bullet NIST’s Manufacturing Lab Prints 2005 Program Guide
bullet Usability Standard Achieves International Status

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Researchers Help Sort Out the Carbon Nanotube Problem

Small- angle neutron scattering pattern

Small- angle neutron scattering pattern provides an inverted representation of how carbon nanotubes flowing in a polymer melt sort themselves by length. Longer nanotubes, which scatter neutrons at lower angles, gather in purple regions, while medium-sized and short nanotubes are indicated by red and yellow, respectively. The dark blue circle in the center of the image is the beam stop, which protects the sensitive detector from the transmitted beam of unscattered neutrons.

Click here for a high-resolution version of this image.

National Institute of Standards and Technology (NIST) and university researchers report a significant step toward sorting out the nanotube “problem”—the challenge of overcoming processing obstacles so that the remarkable properties of the tiny cylindrical structures can be exploited in new polymer composite materials of exceptional strength.

As described in the July 15 issue of Physical Review Letters,* their analysis reveals that, during mixing, carbon nanotubes suspended in viscous fluids can be encouraged to sort themselves by length. Achieving uniform sizes of nanotubes is one of several keys to producing affordable, high-quality polymer nanocomposites.

The team found that, under common processing conditions, shorter carbon nanotubes will flow toward the walls of mixing equipment, while the longer tubes tend to congregate in the interior.

Better understanding of factors that promote this self-sorting will point the way to process adjustments and devices that achieve desired arrangements of nanotubes during bulk manufacturing of polymer nanocomposites, says NIST’s Erik Hobbie, leader of the collaboration, which included scientists from the University of Kentucky and Michigan Technical University.

Many times stronger than steel and possessing superlative thermal, optical and electronic properties, nanotubes have been called small-scale wonders, measuring a few nanometers in diameter and ranging greatly in length. Anticipated nanotube-based technologies range from hydrogen storage to transistors to space elevators. Nearest on the horizon are light-weight, high-strength carbon nanotube polymer structural composites.

With lasers, video microscopes and other optical monitoring equipment, the team tracked how nanotubes—both the single-wall and multiwall varieties—behave when suspended, at several different concentrations, in a polymer melt. They analyzed suspensions ranging in viscosity from syrup-like to watery under different mixing conditions.

The results did not suggest a “magic bullet” for getting nanotubes to align uniformly in the same direction—also critical to reliable processing of high-quality nanocomposites. But the finding that, under “modest flow conditions,” carbon nanotubes will sort by length could point the way to practical methods for bulk separation of nanotubes according to size.

Further information on nanotube-related research can be found at the Polymers Division Web site at

*D. Fry, B. Langhorst, H. Kim, E. Grulke, H. Wang, E.K. Hobbie. Anisotropy of sheared carbon nanotube suspensions. Physical Review Letters, 95, 038304 (July 15, 2005).

Media Contact:
Mark Bello,, (301) 975-3776



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Bioagent Detector Guide Aids First Responder Purchasing

Ever since envelopes containing anthrax bacteria were mailed to Congressional and media offices in 2001 causing several deaths, many first responder departments have worked to improve their ability to quickly detect toxic biological agents. To help them make informed decisions about which biological agent detection devices best meet their needs, the National Institute of Standards and Technology (NIST) recently developed a two-volume guide for the emergency response community. The guide, produced for the Department of Homeland Security (DHS), does not make recommendations. It provides the community with ways to compare and contrast commercially available biological detection equipment.

Volume 1 of the Guide for the Selection of Biological Agent Detection Equipment for Emergency First Responders presents an historical overview of the use of biological agents starting with the Assyrians who used ergot fungi to poison wells as early as 600 B.C. It also describes various bacterial agents, symptoms, effects and treatment as well as the challenges of biological agent detection. The guide includes a market survey of 143 biological agent detection products and commercially available detectors known to the authors as of March 2005. The guide also displays pictures of specific devices that use the technology being discussed.

To help first responders decide on appropriate equipment, the guide cites 19 performance parameters or selection factors, including sensitivity, specificity, start-up and response times, ease-of-use, alarm capability, power requirements, skill level, cost, durability and portability. An appendix lists questions that could assist emergency first responders when selecting the biological agent detection equipment. Volume II includes detailed detection equipment data sheets.

DHS intends to maintain and update the guide as new information on biological detection equipment becomes available. The Guide for the Selection of Biological Agent Detection Equipment for Emergency First Responders is available at After registration, type in "DHS AND guide" in the search box. The link to the Bioagent Dectector Guide will be seen.

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


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Compact JILA System Stabilizes Laser Frequency

A compact, inexpensive method for stabilizing lasers that uses a new design to reduce sensitivity to vibration and gravity 100 times better than similar approaches has been demonstrated by scientists at JILA in Boulder, Colo. JILA is a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder.

The method, described in the July 15 issue of Optics Letters,* stabilizes laser light to a single frequency, so that it can be used as a reliable reference oscillator for technologies such as optical clocks and light-based radar (lidar). The new stabilizer design performs better than similar systems of comparable size and is much smaller and less expensive than the best-performing systems, according to physicist John Hall, a co-author of the paper.

Laser systems are highly sensitive to environmental disturbances, such as electronic “noise” and vibration from soft drink vending machines or other equipment with mechanical motors. To stabilize operations in cases when high precision is needed, lasers are often "locked" to a single wavelength/frequency using an optical “cavity,” a small glass cylinder with a mirror facing inward on each end. Laser light bounces back and forth between the mirrors and, depending on the exact distance between them, only one wavelength will "fit" that distance best and be reinforced with each reflection. Information from this stabilized laser light is then fed back to the laser source to keep the laser locked on this one frequency. But the cavity can vibrate, or expand in response to temperature changes, causing corresponding slight frequency changes. Researchers have tried various improvements such as using cavities made of low-expansion glass.

In the latest advance, the JILA team made the cavity shorter and positioned it vertically instead of horizontally, with symmetrical mounting supports so that gravity and vibration forces yield opposing distortions in the two halves, and thus balance out to zero net effect. The system was demonstrated with an infrared laser. "We designed the cavity so it doesn't care if it's vibrating," says Hall, who helped develop a leading resonant cavity design two decades ago. "We get good performance with a complete reduction of complexity and cost."

The work was supported by the Office of Naval Research, National Aeronautics and Space Administration, National Science Foundation and NIST.

*M. Notcutt, L.S. Ma, J. Ye, and J.L. Hall. 2005. Simple and compact 1-Hz laser system via improved mounting configuration of a reference cavity. Optics Letters. July 15.

Media Contact:
Gail Porter,, (301) 975-3392


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Comments Sought on Draft Federal IT Security Standard

To help federal agencies improve their information technology security and comply with the Federal Information Security Management Act (FISMA) of 2002, the National Institute of Standards and Technology (NIST) recently released for public comment the draft of Federal Information Processing Standard (FIPS) Publication 200, Minimum Security Requirements for Federal Information and Information Systems.

FISMA requires all federal agencies to develop, document and implement agency-wide information security programs and to provide security for the information and information systems that support the operations and assets of the agency. The act called upon NIST to develop the standards and guidelines needed for successful FISMA compliance.

The draft FIPS Publication 200 is the third NIST publication of a three-part series for this purpose. FIPS Publication 199, Standards for Security Categorization of Federal Information and Information Systems, issued in February 2004, requires agencies to categorize their information and information systems as low impact, moderate impact or high impact regarding confidentiality, integrity and availability. NIST SP 800-53, Recommended Security Controls for Federal Information Systems, issued in February 2005, provides guidance on selecting the appropriate controls for 17 key security focus areas.

FIPS Publication 200 provides: (1) a specification for minimum security requirements for federal information and information systems; (2) a standardized, risk-based approach (as described in FIPS Publication 199) for selecting security controls in a cost-effective manner; and (3) links to NIST Special Publication 800-53.

NIST invites public comments on the draft standard until 5 p.m. Eastern Daylight Time on Sept. 13, 2005. The document may be downloaded at

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



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Quick Links

Measurement Challenges In Detecting Cancer Biomarkers

In cancer research, biomarkers are molecules that indicate the presence of cancer in the body. Most are based on abnormal changes or mutations in genes, RNA, proteins and metabolites. Since the molecular changes that occur during tumor development can take place over a number of years, biomarkers potentially can be used to detect cancers early, determine prognosis and monitor disease progression and therapeutic response. Candidate biomarkers, however, frequently are found only in relatively low concentrations amid a sea of other biomolecules, so both biomarker research and possible diagnostic tests depend critically on the ability to make highly sensitive and accurate biochemical measurements.

A special August workshop at the National Institute of Standards and Technology (NIST) will examine the measurement challenges posed by two important biomarker classes, measurement of DNA methylation and serum proteomics. The addition of methyl groups (a molecule with one carbon and three hydrogen atoms) at certain key sites on DNA is known to alter the expression of genes, and might serve as an indicator of when cancer-related genes are “turned on or off.” Serum proteomics involves reliably detecting trace levels of proteins associated with cancer cells. Both approaches have been hampered by the lack of reproducibility and consistency in measurements.

The workshop on Standards, Methods, Assays, Reagents and Technologies (SMART) for Early Cancer Detection and Diagnosis, jointly sponsored by NIST and the Early Detection Research Network (EDRN) of the National Cancer Institute will compare the performance characteristics of different analytical platforms for DNA methylation and serum proteomics, assess the needs for standard methods, assays and reagents for cancer biomarker development and validation, and make recommendations for the development of Standard Reference Materials and standard operating procedures. The SMART workshop will be held at the NIST site in Gaithersburg, Md., from Aug. 18-19, 2005. Details are available at Reporters planning to attend should contact Michael Baum,, (301) 975-2763.

Draft Guidelines Released for IT Security Controls

To help federal agencies comply with the Federal Information Security Management Act (FISMA) of 2002, the National Institute of Standards and Technology (NIST) issued Special Publication 800-53, Recommended Security Controls for Federal Information Systems, in February 2005. NIST SP 800-53 provides guidance on selecting security controls for information systems in key areas such as risk assessment, contingency planning, and identification and authentication. A companion document, NIST SP 800-53A, Guide for Assessing the Security Controls in Federal Information Systems, has been drafted to help agencies take the next step: assessing the effectiveness of security controls once they are in place. NIST invites public comments on this draft guideline until 5 p.m. Eastern Daylight Time on Aug. 31, 2005. NIST SP 800-53A, and instructions on how to submit comments on it, may be found at


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NIST’s Manufacturing Lab Prints 2005 Program Guide

With a value-added contribution of $1.4 trillion, U.S. manufacturing directly accounts for approximately 13 percent of the U.S. gross domestic product. The National Institute of Standards and Technology's (NIST) Manufacturing Engineering Laboratory (MEL) has just released its annual 2005 guide to programs serving that critical national sector. The publication summarizes MEL work in dimensional metrology, homeland and industrial control security, intelligent control of mobility systems, manufacturing interoperability, manufacturing metrology and standards for health care enterprise, mechanical metrology, nanotechnology and smart machining systems. Each program notes the resources, objectives, customer needs addressed, accomplishments, current year plans, lifetime objectives and related measurement and standards work. Special MEL activities also are reviewed, including the laboratory's role in the international Intelligent Manufacturing Systems (IMS) program, Systems Integration for Manufacturing Applications (SIMA) and the National Science and Technology Council Interagency Working Group on Manufacturing Research and Development. MEL: The Programs of the Manufacturing Engineering Laboratory 2005 (NISTIR 7218) is available at (.pdf; download Acrobat Reader). For a paper copy, contact Lisa Fronczek at


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Usability Standard Achieves International Status

Software that is poorly designed, inappropriate for specific tasks or just difficult to use can be frustrating, unproductive and costly for both businesses and individuals. To help remedy the problem, computer scientists at the National Institute of Standards and Technology (NIST) have been working for several years with private industry, including The Boeing Co., Oracle Corp., and Microsoft Corp. to develop a standard way to test and evaluate software usability. The resulting effort, the Common Industry Format (CIF) for Usability Test Reports, recently was approved as a worldwide standard by the Software and Systems Engineering Committee of the International Organization for Standardization. For more information on CIF, see

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Editor: Gail Porter

Date created: 7/22/05
Date updated:7/26/05