In This Issue...
NIST Finds That Ethanol-Loving Bacteria Accelerate Cracking of Pipeline Steels
U.S. production of ethanol for fuel has been rising quickly, topping 13 billion gallons in 2010. With the usual rail, truck and barge transport methods under potential strain, existing gas pipelines might be an efficient alternative for moving this renewable fuel around the country. But researchers at the National Institute of Standards and Technology (NIST) caution that ethanol, and especially the bacteria sometimes found in it, can dramatically degrade pipelines.
At a conference this week,* NIST researchers presented new experimental evidence that bacteria that feed on ethanol and produce acid boosted fatigue crack growth rates by at least 25 times the levels occuring in air alone.
The NIST team used a new biofuels test facility to evaluate fatigue-related cracking in two common pipeline steels immersed in ethanol mixtures, including simulated fuel-grade ethanol and an ethanol-water solution containing common bacteria, Acetobacter aceti. Ethanol and bacteria are known to cause corrosion, but this is the first study of their effects on fatigue cracking of pipeline steels.
"We have shown that ethanol fuel can increase the rate of fatigue crack growth in pipelines," NIST postdoctoral researcher Jeffrey Sowards says. "Substantial increases in crack growth rates were caused by the microbes. These are important data for pipeline engineers who want to safely and reliably transport ethanol fuel in repurposed oil and gas pipelines."
Ethanol, an alcohol that can be made from corn, is widely used as a gasoline additive due to its oxygen content and octane rating. Ethanol also can be used as fuel by itself in modified engines. The NIST tests focused on fuel-grade ethanol.
The tests were performed on X52 and X70 pipeline steels, which are alloys of more than a dozen metals. Simulated fuel-grade ethanol significantly increased crack growth at stress intensity levels found in typical pipeline operating conditions, but not at low stress levels. The cracking is related to corrosion. The X70 steel, which is finer-grained than X52, had lower rates of crack growth at all stress levels. This was expected because larger grain size generally reduces resistance to fatigue. In the bacteria-laden solutions, acid promoted crack growth at stress intensity levels found in typical pipeline operating conditions.
Preliminary tests also suggested that glutaraldehyde, a biocide used in oil and gas operations, may help control bacterial growth during ethanol transport.
The findings are the first from NIST's biofuels test facility, where material samples are installed in hydraulic test frames and subjected to load cycles while immersed in fuel inside a transparent polymer tank. Fatigue crack growth and other properties are observed over a period of up to 10 days. NIST staff expect to continue and possibly expand the research to other potential biofuels such as butanol or biodiesel.
Collaborators at the Colorado School of Mines provided the bacteria, which were isolated from industrial ethanol storage tanks. The research was supported by the U.S. Department of Transportation.
* J.W. Sowards, T.D. Weeks, J.D. McColskey, C. Williamson, L. Jain and J.R. Fekete. Effect of ethanol fuel and microbiologically influenced corrosion on the fatigue crack growth behavior of pipeline steels. Presented at DOD Corrosion Conference 2011, La Quinta, Calif., August 1, 2011.
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Novel Coatings Show Great Promise as Flame Retardants in Polyurethane Foam
Gram for gram, novel carbon nanofiber-filled coatings devised by researchers from the National Institute of Standards and Technology (NIST) and Texas A&M University outperformed conventional flame retardants used in the polyurethane foam of upholstered furniture and mattresses by at least 160 percent and perhaps by as much as 1,130 percent.
The impressive test results, reported in the journal Polymer,* suggest that significant fire-safety advantages can be gained by coating polyurethane foam (PUF) with a club-sandwich-like arrangement of thin layers containing carbon nanofibers and polymers. The upshot, says NIST researcher Rick Davis, is that the experimental coating seems to create the equivalent of a "fire-resistant armor" on the porous foam.
Ignition of soft furnishings account for about 5 percent of residential fires, and the consequences are disproportionately high. These fires are responsible for a third of fire-caused deaths of civilians and 11 percent of property losses due to fires in homes.
The flammability of mattresses is regulated by federal law. A complementary rule to regulate the flammability of upholstered furniture has been proposed recently.
Several organizations, however, have challenged the health and safety of some flame retardants designed to protect against soft furnishing fires. And, a bill pending in California would ban the use of certain halogenated flame retardants in that state.
Today, recipes for making PUFs result in foams in which fire retardants are embedded in the interior. In contrast, the experimental technology uses the carbon nanofiber fire retardant as a coating that covers all the nooks and crannies on the sponge-like PUF surface. The new approach, says Davis, should be attractive to PUF manufacturers because the surface treatment has the potential to deliver a low flammability PUF without major change to the foam manufacturing process, thus saving time and money.
The NIST-Texas A&M team coated square samples of commercially available PUF with four bilayers of a carbon nanofiber-polymer combination.** The average thickness of the coating was about 360 nanometers, increasing the mass of the foam by only 3 percent. By themselves, the carbon nanofibers accounted for 1.6 percent of the foam mass. Since the carbon nanofibers are only in the coating, all the carbon nanofibers are clumped like matted whiskers within the top 360 nanometers of the surface—assembled into the fire-blocking armor.
The team used a standard benchtop fire test to measure the fire performance of coated and uncoated PUF. The carbon nanofiber coatings reduced PUF flammability (measured as the peak heat release rate from an ignited specimen) by 40 percent. That result was more than 3 times better than achieved by putting the same carbon nanofibers in the foam (part of the foam recipe).
When compared at the same concentrations, the carbon nanofiber coating significantly outperforms three classes of commercially available flame retardants commonly used in PUF. Reductions in flammability achieved with the coating, according to the researchers, were 158 percent better than the reduction calculated for nonhalogens, 288 percent better than halogens, and 1,138 percent better than halogen-phosphorous flame retardants.
Additionally, the experimental coating "prevents the formation of a melt pool of burning foam, which in a real fire scenario, may further reduce the resulting fire threat of burning soft furnishings," the authors write.
* Y.S. Kim, R. Davis, A.A. Cain and J.C. Grunlan, Development of layer-by-layer assembled carbon nanofiber-filled coatings to reduce polyurethane foam flammability. Polymer. Vol. 52, Issue 13, June 8, 2011.
Wrapped up in their work: Molecular model shows a single-strand DNA molecule (yellow ribbon) coiled around an "armchair" carbon nanotube.
Credit: Roxbury, Jagota/NIST
Single-wall carbon nanotubes are usually about a nanometer in diameter, but they can be millions of nanometers in length. It’s as if you took a one-atom-thick sheet of carbon atoms, arranged in a hexagonal pattern, and curled it into a cylinder, like rolling up a piece of chicken wire. If you’ve tried the latter, you know that there are many possibilities, depending on how carefully you match up the edges, from neat, perfectly matched rows of hexagons ringing the cylinder, to rows that wrap in spirals at various angles—“chiralities” in chemist-speak.
Chirality plays an important role in nanotube properties. Most behave like semiconductors, but a few are metals. One special chiral form—the so-called “armchair carbon nanotube”**—behaves like a pure metal and is the ideal quantum wire, according to NIST researcher Xiaomin Tu.
Armchair carbon nanotubes could revolutionize electric power systems, large and small, Tu says. Wires made from them are predicted to conduct electricity 10 times better than copper, with far less loss, at a sixth the weight. But researchers face two obstacles: producing totally pure starting samples of armchair nanotubes, and “cloning” them for mass production. The first challenge, as the authors note, has been “an elusive goal.”
Separating one particular chirality of nanotube from all others starts with coating them to get them to disperse in solution, as, left to themselves, they’ll clump together in a dark mass. A variety of materials have been used as dispersants, including polymers, proteins and DNA. The NIST trick is to select a DNA strand that has a particular affinity for the desired type of nanotube. In earlier work,*** team leader Ming Zheng and colleagues demonstrated DNA strands that could select for one of the semiconductor forms of carbon nanotubes, an easier target. In this new paper, the group describes how they methodically stepped through simple mutations of the semiconductor-friendly DNA to “evolve” a pattern that preferred the metallic armchair nanotubes instead.
“We believe that what happens is that, with the right nanotube, the DNA wraps helically around the tube,” explains Constantine Khripin, “and the DNA nucleotide bases can connect with each other in a way similar to how they bond in double-stranded DNA.” According to Zheng, “The DNA forms this tight barrel around the nanotube. I love this idea because it’s kind of a lock and key. The armchair nanotube is a key that fits inside this DNA structure—you have this kind of molecular recognition.”
Once the target nanotubes are enveloped with the DNA, standard chemistry techniques such as chromatography can be used to separate them from the mix with high efficiency.
“Now that we have these pure nanotube samples,” says team member Angela Hight Walker, “we can probe the underlying physics of these materials to further understand their unique properties. As an example, some optical features once thought to be indicative of metallic carbon nanotubes are not present in these armchair samples.”
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Two wildland-urban interface (WUI) fires* earlier this year outside of Amarillo, Texas, destroyed 70 homes, burned more than 25,000 acres of land, and caused nearly $6 million in property damage. But thanks to a collaborative effort between the National Institute of Standards and Technology (NIST) and the Texas Forest Service (TFS), they are now the most thoroughly investigated and scientifically evaluated events of their kind.
A member of a joint NIST-Texas Forest Service study team collects data on a Amarillo, Texas, building damaged by wildfires in February 2011.
During a three-week reconnaissance following the start of four fires in the Amarillo area on Feb. 27, 2011, a NIST-TFS study team—for the first time in an actual fire situation—used a NIST-developed, two-tiered WUI data-collection methodology to acquire approximately 163 gigabytes of data and more than 29,000 photographs to document two of the blazes, now known as the Willow Creek and Tanglewood Complex fires.
This massive amount of accumulated information is the foundation of a NIST-TFS study assessing the impact of the two wildfires on structures in the region. The first report from that study** is now available online at www.nist.gov/manuscript-publication-search.cfm?pub_id=908719.
“We gathered as much data as possible to document the topographical features of the region, detail the types and construction of structures that were impacted or endangered by the fires, identify defensive actions taken, and develop a timeline of the fires’ movement and spread,” says NIST fire protection engineer and Amarillo study team leader Alex Maranghides. “This will allow us to understand why some structures burned to the ground while others close by did not. That knowledge could help us build more fire-resilient buildings in the future.”
Fortunately, Maranghides had trained TFS field investigators last fall on the use of the NIST data collection methodology, so they were in the field employing the two-tiered system within 48 hours of the start of the Amarillo fires. The first tier—a survey for recording broad observations of damage across the entire fire perimeter—provides input for the second tier. The latter includes a kit with tools designed to capture the specific details needed for developing a precise fire timeline, building computer models to study a fire’s behavior in depth, and most importantly, identifying and assessing all of the factors that determine the response of different structures to a WUI fire (such as the types and amounts of combustibles on or around a structure). Maranghides and colleague Glenn Forney traveled to Texas in early March 2011 to assist the TFS investigators with their reconnaissance and to evaluate how the NIST data-collection system performed in the field.
“The level of detail that can be obtained with our system is a vast improvement over traditional data-collection procedures that focus simply on the number of structures damaged or destroyed, without taking into account the underlying factors that actually cause the destruction,” Maranghides says.
The fact that TFS staff had canvassed the Tanglewood Complex last October to assess its susceptibility to a wildfire event was an added bonus for the NIST-TFS study. “This gave us the unique advantage of having data collected about the area before, during and after the fire,” Maranghides says.
The Amarillo study is part of a broad NIST program to study WUI fires around the nation to gain a better understanding of their behavior; develop and standardize data collection and computer modeling tools; and facilitate the creation, testing and implementation of innovative fire protection and prevention methods. These research efforts will lead to improved standards, codes and practices to address WUI fires in the United States.
For more information about NIST’s WUI fire research, go to www.nist.gov/el/topic_wui.cfm. For more information about the TFS and its partnership with NIST on this study, contact Linda Moon, TFS Communications, (979) 458-6606, email@example.com.
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Seeking to measure the U.S. first responder community’s need for documentary standards at the federal, state and local levels, the National Institute of Standards and Technology (NIST) Law Enforcement Standards Office (OLES) and its partners will distribute documentary standards to first responders as part of a pilot project running August 1, 2011, through October 2011. The pilot will help OLES gauge whom needs access to standards in the federal, state and local responder communities; what types of standards they use the most; and how OLES can better serve this community in the future.
Generally developed by private-sector standards organizations and trade groups, documentary standards can specify product characteristics; establish accepted test methods and procedures; characterize materials; define processes and systems; or specify knowledge, training and competencies for specific tasks. First responders use basic testing and product standards primarily to inform their equipment procurement, operations and training. Typical subjects include personal protective equipment, detection systems, body armor, urban search and rescue Robots, communications systems and biometric ID systems.
The pilot program is open to first responders with .gov and .mil e-mail addresses. OLES purchased documentary standards for download from ASTM International and IEEE and has included access to view the National Fire Protection Association (NFPA) standards. The standards are available at http://i2.saiglobal.com/landingpage/nist/.
Included among the approximately 1,000 available standards are, for example, ANSI N42.33-2006, American National Standard for Portable Radiation Detection Instrumentation for Homeland Security; NFPA 1906: Standard for Wildland Fire Apparatus, 2006 Edition; and ASTM E2592-07, Standard Practice for Evaluating Cache Packaged Weight and Volume of Robots for Urban Search and Rescue.
Federal government standards and guidance such as the Code of Federal Regulations and Department of Defense Military Specifications also are included.
OLES will share the data gathered through the pilot with the agencies as well as with the standards development organizations.
OLES is working with SAIC, SAI Global Inc., ASTM International, IEEE, and NFPA for this pilot project. If sufficient interest is shown during the initial pilot, NIST OLES will look into sponsoring a follow-up pilot to include responders who do not have a .gov or .mil address.
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The National Institute of Standards and Technology (NIST) today* said that it will conduct a full technical study on the impacts of the May 22, 2011, tornado that struck Joplin, Mo.
The remains of what was once a home improvement store in Joplin, Mo., showing the destructive power of the tornado that struck the area in May 2011.
The massive tornado was rated category EF5, the most powerful on the Enhanced Fujita scale. According to the National Weather Service (NWS) and the Federal Emergency Management Agency (FEMA), the multiple-vortex storm impacted an area approximately three-quarters of a mile wide by 14 miles long, destroyed some 8,000 structures in its path, and killed more than 150 people. This makes it the single deadliest tornado in the United States in the 61 years that official records have been kept.
“The widespread destruction across a range of building and construction types, along with the tragically large death toll despite a comparatively substantial warning time, makes the Joplin tornado a unique event to research,” says Marc Levitan, leader of the NIST study. “The lessons learned will be extremely valuable to national efforts aimed at reducing losses of lives and property from tornados.”
From May 25-28, NIST sent four engineers to Joplin to conduct a preliminary reconnaissance of building performance and emergency communications during the tornado. Based on the analysis of the data collected and other criteria required by regulation, NIST Director Pat Gallagher established a research team under the National Construction Safety Team Act to proceed with a more comprehensive study of the impacts of the disaster.
The objectives of the NIST technical study are to:
determine the characteristics of the wind hazard from the tornado;
determine the pattern, location and cause of injuries and fatalities, and how these numbers were affected by emergency communications and the public response to those communications;
determine the performance of residential, commercial and critical (police stations, firehouses, hospitals, etc.) buildings;
determine the performance of lifelines (natural gas, electrical distribution, water, communications, etc.) as they relate to maintaining building operation; and
make recommendations, if warranted, for improvements to building codes, standards and practices based on the findings of the study.
The same engineers who performed the preliminary reconnaissance will conduct this more extensive study. They will be joined by an expert on severe storms from the Commerce Department’s National Oceanic and Atmospheric Administration (NOAA).
Observations and findings from the preliminary reconnaissance suggest the following:
The current tornado rating procedure, the Enhanced Fujita intensity scale, lacks adequate indicators for estimating the intensity of tornadoes such as the one in Joplin.
The 24-minute warning time for this event was nearly double the national average reported by the NWS as 13-14 minutes.
The Joplin siren-based warning system was not intended to alert people who were indoors.
There were no designated public safe rooms or tornado shelters in Joplin.
Most buildings in Joplin did not have basements.
A large number of residential and non-residential buildings in Joplin sustained complete loss of function, requiring either major repair or replacement.
Critical and high-occupancy buildings in Joplin did not perform better than buildings of similar construction type in lower-risk categories with regard to loss of function or damage.
Reinforced concrete frame and steel frame buildings that were surveyed also suffered total loss of function and major damage to the envelope and interior; however, the structural frame remained largely intact.
Most other buildings, including those constructed with pre-cast concrete, metal, concrete and brick masonry, and wood-frame, suffered partial or complete collapse.
Both the NIST preliminary reconnaissance and the upcoming technical study led by NIST build on a partnership between the agency’s Disaster and Failure Studies Program and the interagency National Windstorm Impact Reduction Program. For more information on the Joplin tornado study, and NIST’s 40-plus years of experience studying structural failures and fires, visit http://www.nist.gov/el/disasterstudies/index.cfm.
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A team from the National Institute of Standards and Technology (NIST) is working with the U.S. National Guard on a coordinated effort to train emergency first responders in the delicate and potentially critical task of securing reliable samples of suspected biothreats. The project, dubbed “Operation Vigilant Sample,” seeks to coordinate training programs for first responders at the state, local and federal levels based on newly developed sample collection protocols.
NIST serves as an objective third party to evaluate how well the standards are being integrated into practice, and to develop quantitative metrics to evaluate training exercises, according to Jayne Morrow, an environmental engineer at NIST who led the development of the standard, which was released last year.*
“The aim of the operation is to provide a training lane that can help standardize the interface between initial local, state and federal responders to make sure everyone gets what they need from a collected sample of suspicious material, including providing a solid chain of custody,” says Morrow. “Our goal here at NIST is to help integrate standards and training so that everyone from first responders to investigators knows they can rely on that sample.”
The National Guard has 57 Civil Support Teams (CSTs) around the country that serve as the first wave of federal response to domestic chemical, biological, radiological and nuclear incidents. The teams assess suspected attacks, advise civilian responders, and facilitate the arrival of additional state and federal military forces. Operation Vigilant Sample will help the CSTs by providing consistent training among the first responders with whom they work.
In February, 2011, NIST participated in a 72-hour Operation Vigilant Sample exercise at the army’s Medical Research Institute of Infectious Diseases at Fort Detrick, Md. “After leading development of the ASTM standards relied on in the exercises,” explains Morrow, “we are now assisting the community with integration by evaluating how well coordinated and effective were the communications as the operation unfolded, and to see what additional standards are still needed.”
“The Operation Vigilant Sample exercises have allowed the various state and federal responders an opportunity to develop their standard operating procedures in a collaborative manner,” explains Capt. Bryon Marsh of the National Guard Bureau. “As national guidance such as the ASTM standards become available to responders, it is important that we have the opportunity to incorporate them as a community and standardize our response efforts.”
In addition to these exercises and establishing training and standards, NIST is working with its partners at various agencies to enhance coordination between first responders, public health laboratories, the Centers for Disease Control and Prevention laboratory response network, Federal Bureau of Investigation weapons of mass destruction coordinators, and the National Guard’s CSTs.
“Our participation in Operation Vigilant Sample is part of a larger effort to support the training of first responders, and it’s a chance to demonstrate the effectiveness of the ASTM standards,” says Morrow. “This is all about response planning, getting together before something happens and seeing that standards are integrated into the community. Field exercises are one critical element to successful integration and a well-coordinated response.”
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The Smart Grid Interoperability Panel (SGIP) has made the first six entries into its new Catalog of Standards,* a technical document now available as a guide for all involved with Smart Grid-related technology. The six standards, all of which were approved previously by the SGIP’s Governing Board, received approval by more than 90 percent of the broader SGIP membership in voting earlier this month.
The SGIP, a consensus-based group of more than 675 public and private organizations, was created by the National Institute of Standards and Technology (NIST) to coordinate the development of Smart Grid standards. While the SGIP does not develop or write these standards directly, a vote of approval signifies that its member organizations have agreed on the inclusion of a group of standards in the catalog.
The six entries relate to high-priority national standards needed to create a modern, energy-efficient power grid with seamlessly interoperable components. In order to convert today’s power grid—which still functions largely as it did when grids were created in the 19th century—into a power distribution network that can enable the wide use of electric vehicles, as well as incorporate renewable energy sources such as wind and solar, a number of new standards must be established. Among these are the catalog’s first six entries, which include:
The six catalog entries cover five of the 19 Priority Action Plans, or PAPs, named by grid experts as those issues most necessary to address early for the Smart Grid to function properly. PAPs 0, 1, 2, 10 and 11—the latter of which covers both electric vehicle standards—are now addressed in the catalog.
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The National Institute of Standards and Technology (NIST) will co-sponsor the 2011 Biometric Consortium Conference, Sept. 27-29, 2011, at the Tampa Convention Center in Tampa, Fla. The annual conference, co-sponsored by the National Security Agency, is focused on biometric technologies and applications—techniques like fingerprint or iris recognition that can be used to identify humans based on one or more intrinsic physical or behavioral characteristics.
NIST's Biometric Web Services team captures a fingerprint remotely using Web Services for Biometric Devices, which is a new system built on standard web technologies
Conference attendees will include policy makers, government and industry executives, information technology users and developers, law enforcement officials, and systems integrators and researchers involved in using biometrics for personal identification and authentication applications for homeland security, identity protection and electronic commerce.
The agenda offers two and a half days of presentations, seminars and panel discussions with internationally recognized experts in biometric technologies, system and application developers, IT business strategists, and senior managers from government and industry.
In addition to presentations on government agency activities in biometrics, there will be sessions on biometrics as a service, Rapid DNA and a panel discussion on international biometrics. NIST researchers will discuss iris recognition and technology, the face quality and analysis challenge, developments in latent fingerprint technologies, fingerprint image compression, and interoperability via biometric web services. Other NIST-related topics will include an ANSI/NIST standard update and progress toward a voice standard, the security and privacy challenges of biometric authentication for online transactions and mobile devices, and current work on conformance test architecture and test suite developments.
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The National Institute of Standards and Technology (NIST) will host the second annual National Initiative for Cybersecurity Education (NICE) Workshop, September 20-22, 2011, at its Gaithersburg, Md., campus. NIST coordinates NICE, a national campaign focused on enhancing cybersecurity in the United States by accelerating the availability of educational and training resources designed to improve the cyber behavior, skills and knowledge of every segment of the population.
The theme of the workshop is “Shaping the Future of Cybersecurity Education—Engaging Americans in Securing Cyberspace.” White House Cybersecurity Coordinator Howard Schmidt will deliver a keynote address on September 21. “NICE is just really getting started, so this is a great time for everyone to come together and talk about our goals and priorities,” said NICE National Lead Ernest McDuffie. The draft strategic plan will be issued for public comment in mid-August, 2011, McDuffie said.
The workshop will include two and a half days of interactive discussions focusing on the three goals of the NICE initiative: raising awareness among the American public; broadening the pool of skilled workers capable of supporting a cyber-secure nation; and developing and maintaining an unrivaled, globally competitive cybersecurity workforce. Other presentations include “eCity,” a public-private initiative started in San Diego, Calif. that is expanding to San Antonio, Texas, and Maryland, and student cybersecurity competitions as well as other innovative programs such as repurposing the country’s displaced workforce into cybersecurity jobs.
“Shaping the Future of Cybersecurity Education—Engaging Americans in Securing Cyberspace” is expected to draw hundreds of participants from government, academia and industry as well as small- and medium-sized business professionals and educators at the K-12, community college and university levels.
Universities are working with workshop organizers to participate. Students in cybersecurity programs will be invited to participate in the student webinar portion of the workshop. University programs interested in participating should contact Magdalena Benitez at firstname.lastname@example.org.
More information on the workshop, including an agenda and registration form is available at http://csrc.nist.gov/nice/. Registration runs through Sept. 12, 2011.
Reporters interested in attending the workshop should contact Evelyn Brown, email@example.com, or phone (301) 975-566
Media Contact: Evelyn Brown, firstname.lastname@example.org, (301) 975-5661