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Tech Beat - June 27, 2012

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Editor: Michael Baum
Date created: June 27, 2012
Date Modified: June 27, 2012 
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NIST Announces Up to $3M in Funding for Three New Manufacturing Extension Partnership Centers

The National Institute of Standards and Technology (NIST) is soliciting proposals to establish three new Hollings Manufacturing Extension Partnership (MEP) centers in Arizona, Maryland and Rhode Island. NIST has $3 million in funding to support the centers, which would join the existing network of more than 400 MEP centers and field offices in all 50 states and Puerto Rico. The centers primarily help small- and medium-sized manufacturers enhance their productivity, innovative capacity, technological performance and global competitiveness.

NIST anticipates funding each project up to $1 million for the first year of operation, and each center must identify a nonfederal cost share of at least 50 percent of the total project cost for that first year. Any renewal funding of an award will require nonfederal cost sharing that increases to a maximum of two-thirds of the center's budget at year five and beyond.

U.S.-based nonprofit institutions or organizations, including universities, state and local governments and existing MEP centers are eligible to submit a proposal. An eligible organization may work individually or include proposed subawards or contracts with others in a project proposal, effectively forming a team. All proposals must be received no later than 5 p.m. Eastern time on August 20, 2012.

Manufacturing extension services are provided by using the most cost effective, local, leveraged resources through the coordinated efforts of a regionally based MEP center and local technology resources. The management and operational structure of each MEP center is based on the characteristics of the manufacturers in the region and locally available resources with demonstrated experience working with manufacturers.

Additional information on the application process is available in the notice of Federal Funding Opportunity posted at Grants.gov (www.grants.gov/) under Funding Opportunity Number 2012-NIST-MEP-AZ-MD-RI-01.

NIST MEP will hold an information webinar for organizations considering applying to this opportunity on July 18, 2012, at 2 p.m. Eastern time. More information is available on the NIST MEP website: www.nist.gov/mep.

Media Contact: Jennifer Huergo, jennifer.huergo@nist.gov, 301-975-6343

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Novel Clay-based Coating May Point the Way to New Generation of Green Flame Retardants

In searching for better flame retardants for home furnishings—a large source of fuel in house fires—National Institute of Standards and Technology (NIST) researchers defied the conventional wisdom and literally hit a wall, one made of clay.

clay flame retardant
Using a testing device called a cone calorimeter, NIST researchers measure the heat-release rate and other flammability properties of materials. Above, untreated polyurethane foam ?catches fire? from a nearby heat source. Below, foam treated with a novel clay-filled coating did not ignite when exposed to the same heat source. Instead, a fast-growing protective layer?called char?forms on the surface.
Credit: NIST
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It wasn't a dead end, but rather a surprising result that may lead to a new generation of nonhalogenated, sustainable flame retardant technology for polyurethane foam. The thick, fast-forming coating that the NIST team created has a uniformly high concentration of flame-inhibiting clay particles, and it adheres strongly to the Swiss cheese-like surface of polyurethane foam, which is used in furniture cushions, carpet padding, children's car seats, and other items.

"In effect, we can build the equivalent of a flame-retarding clay wall on the foam in a way that has no adverse impact on the foam manufacturing process," explains NIST fire researcher Rick Davis. "Our clay-based coatings perform at least as well as commercial retardant approaches, and we think there's room for improvement. We hope this new approach provides industry with practical alternative flame retardants."

Davis and his NIST colleagues describe the new coating and the process they used to make it in the journal ACS Macro Letters.*

To date, researchers have built up coatings by stacking thin layers in pairs that are held together by basic electrical attraction. With no clay present, just a pure polymer, a thick coating is formed rapidly, but it isn't a fire retardant. With clay in every other layer, either the coating is too thin or the clay content is too low to be an effective fire retardant.

The NIST team tried something you would expect not to work: trilayers consisting of a positively charged bottom topped by two negatively charged layers. Under most circumstances, the two negative layers would repulse each other, but it turns out that hydrogen bonds formed between the two negative layers and overcame this repulsive force.

The resulting trilayer yields a unique result: a thick, fast-forming, and high concentration clay coating on polyurethane foam. This nanocomposite coating is 10 times thicker, contains 6 times more clay, and achieves this using at least 5 times fewer total layers than the traditional bilayer coatings.

"The eight trilayer system thoroughly coated all internal and external surfaces of the porous polyurethane foam, creating a clay brick wall barrier that reduced foam flammability by as much as 17 percent of the peak heat release rate," the team reported. Only a few hundred nanometers thick, the final coating is transparent and the foam still has the same softness, support and feel.

Compared with amounts of current flame retardant applied to polyurethane foam, only half as much of the new clay-based coating was required to achieve comparable levels of performance.

* Y.S. Kim, R. Harris and R. Davis. Innovative approach to rapid growth of highly clay-filled coatings on porous polyurethane foam. ACS Macro Letters, 2012, 1, 820−824. .dx.doi.org/10.1021/mz300102h

Media Contact: Mark Bello, mark.bello@nist.gov, 301-975-3776

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Hark! Group Demonstrates First Heralded Single Photon Source Made from Silicon

In an important step towards more practical quantum information processing, researchers from the National Institute of Standards and Technology (NIST), the University of California, San Diego; and the Politecnico di Milano in Milan, Italy, have demonstrated the first heralded single photon source made from silicon.* This source complements two other recently developed silicon-based technologies—interferometers for manipulating the entanglement of photons and single photon detectors—needed to build a quantum optical circuit or a secure quantum communication system.

heralded photons
Illustration of the process of photon pair generation, in which input pump photons spontaneously generate special pairs of new photons that emerge at precisely the same time, with one at a slightly lower frequency and the other a slightly higher frequency, after which heralding occurs.
Credit: Srinivasan, Davanco/NIST
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The line between “interesting” and practical in advanced electronics and optics often comes down to making the new device compatible with existing technology. According to NIST scientist Kartik Srinivasan, the new 0.5 mm x 0.05 mm-sized heralded photon generator meshes with existing technology in three important ways: it operates at room temperature; it produces photons compatible with existing telecommunications systems (wavelengths of about 1550 nanometers); and it’s in silicon, and so can be built using standard, scalable fabrication techniques.

A “heralded” photon is one of a pair whose existence is announced by the detection of its partner—the “herald” photon. To get heralded single photons, the group built upon a technique previously demonstrated in silicon called photon pair generation.**

In photon pair generation, a laser pumps photons into a material whose properties cause two incoming pump photons to spontaneously generate a new pair of frequency-shifted photons. However, while these new photons emerge at precisely the same time, it is impossible to know when that will occur.

“Detecting one of these photons, therefore, lets us know to look for its partner,” says Srinivasan. “While there are a number of applications for photon pairs, heralded pairs will sometimes be needed, for example, to trigger the storage of information in future quantum-based computer memories.”

According to Srinivasan, the group’s silicon-based device efficiently produced pairs of single photons, and their experiment clearly demonstrated they could herald the presence of one photon by the detection of the other.

While the new device is a step forward, it is not yet practical, according to co-author Professor Shayan Mookherjea at UC San Diego, because a single source is not bright enough and a number of other required functions need to be integrated onto the chip. However, putting multiple sources along with their complementary components onto a single chip—something made possible by using silicon-based technology—could supply the performance needed for practical applications.

The work was among the three finalists and received an honorable mention in the Maiman Student Paper Competition.

* M. Davanco, J. R. Ong, A. B. Shehata, A. Tosi, I. Agha, S. Assefa, F. Xia, W. Green, S. Mookherjea and K. Srinivasan, Telecommunications-band heralded single photons from a silicon nanophotonic chip. Applied Physics Letters, 100, 261104 (2012).
** Many recent advances have been made by groups at Northwestern, Cornell, NTT Laboratories in Japan, the University Libre de Bruxelles in Belgium, the University of Briston in the UK, and the University of Sydney in Australia.

 

Media Contact: Mark Esser, mark.esser@nist.gov, 301-975-8735

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Pollutants Could Pose Health Risks for Five Sea Turtle Species

Researchers at the Hollings Marine Laboratory (HML) and four partner organizations have measured for the first time concentrations of 13 perfluoroalkyl compounds (PFCs) in five different endangered species of sea turtles. While PFC toxicology studies have not yet been conducted on turtles, the levels of the compounds seen in all five species approach the amounts known to cause adverse health effects in other animals.

hawksbill turtle
A hawksbill sea turtle swims above a coral reef in waters off the British Virgin Islands.
Credit: Copyright Mar-y-Sol Gallery
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PFCs are man-made compounds that have many uses including stain-resistant coatings, fire-fighting foams and emulsifiers in plastics manufacturing. They have become widespread pollutants, are detectable in human and wildlife samples worldwide, infiltrate food chains, and have been shown in laboratory animals—rats, mice and fish—to be toxic to the liver, the thyroid, neurobehavioral function and the immune system. The PFCs most commonly found in the environment are perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA).

Located in Charleston, S.C., the HML is a collaboration of the National Institute of Standards and Technology (NIST), the National Oceanic and Atmospheric Administration (NOAA), the South Carolina Department of Natural Resources, the College of Charleston and the Medical University of South Carolina.

"In our experiment, we wanted to accomplish two goals," says NIST research biologist and study lead Jennifer Keller. "We wanted to get the first accurate measurements of the plasma blood concentrations of PFCs in five sea turtle species across different trophic [food chain] levels, and then compare those concentrations to ones known to cause toxic effects in laboratory animals. That way, we could estimate the potential health risks from PFC exposure for all five turtles."

The five sea turtle species studied were the green, hawksbill, leatherback, loggerhead and Kemp's ridley. Their preferred diets range up the food chain from the green's sea grasses and algae to the crabs favored by the Kemp's ridley. The researchers expected that the PFC concentrations would be higher in species that fed farther up the food chain, since their prey's tissues would probably concentrate the pollutants.

This was generally the case. Plant-eating green turtles had the lowest plasma concentrations for the majority of PFCs examined, especially PFOS. As expected, leatherbacks, loggerheads and Kemp's ridleys had progressively higher PFOS concentrations. Surprisingly, however, hawksbills—who browse low on the food chain, primarily on sponges—recorded the second-highest average concentration of PFOS and were the only species to have a detectable PFOA level. The researchers surmise that this may relate to the locations where the hawksbills forage, or it may suggest that sponges have unusually high concentrations of PFOS and PFOA.

In the second part of the study, Keller and her colleagues compared the plasma concentrations of PFOS that they found in the five sea turtle species with previously reported concentrations that were shown to have adverse health effects in laboratory animals. The results showed that hawksbills, loggerheads and Kemp's ridleys had PFOS concentrations approaching those linked to liver and neurobehavioral toxicity in other animals; levels in loggerheads and Kemp's ridleys approached those linked to thyroid disruption in other animals; and all five species had levels that approached those linked to suppressed immunity in other animals.

"Better understanding the threat of PFCs, especially PFOS, to sea turtles can help wildlife managers and others develop strategies to deal with potential health problems," Keller says. "Our study provides the first baseline data in this area but more research is needed—especially for hawksbills after seeing their unexpectedly high PFC exposure."

Researchers from the College of Charleston's Grice Marine Laboratory, NOAA's National Marine Fisheries Service and the Loggerhead Marinelife Center also contributed to the study.

* J.M. Keller, L. Ngai, J.B. McNeill, L.D. Wood, K.R. Stewart, S.G. O'Connell and J.R. Kucklick. Perfluoroakyl contaminants in plasma of five sea turtle species: Comparisons in concentration and potential health risks. Environmental Toxicology and Chemistry, Vol. 31, No. 6, pp. 1223-1230 (June 2012). DOI: 10.1002/etc.1818

Media Contact: Michael E. Newman, michael.newman@nist.gov, 301-975-3025

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NIST Goes the Distance for the Olympics

In yet another Olympian feat of measurement, researchers at the National Institute of Standards and Technology (NIST) recently calibrated a tape that will be used to measure out the distance of this summer's Olympic marathon—a distance of 42.195 km (traditionally, 26 miles 385 yards)—to 1 part in 1,000.

Blackburn
NIST technician Christopher Blackburn uses a microscope to precisely align a retroreflector over the center of a hash mark on a measuring tape.
Photo credit: Bruce Borchardt
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Measurement is a vital aspect of the Olympic Games. Officials measure the height of jumps, the speed of races, and the mass of weights to determine who wins a medal and who goes home. The marathon is no different. Because of the difficulties in measuring out the distance, the International Association of Athletic Federations (IAAF) only recognized best times and didn't begin awarding world records for marathons until 2004 when a method using a device called a Jones Counter was officially recognized as sufficiently accurate.

Developed by a father-son duo in the early 1970s,* the Jones Counter is a simple geared device that counts the revolutions of a bicycle wheel. To calibrate the device, course measurers lay out a calibrated measuring tape at least 30 meters in length. Once they have determined the number of revolutions that equal that distance—and a couple of successively longer distances—they follow painstaking procedures for laying out the rest of the course. The measurements, which can take hours to complete, will ensure that the shortest distance a runner will run will be at least the required distance and no more than about 40 meters over, corresponding to an error of about 1 part in 1,000.

Chris Blackburn, a physical science technician with NIST's Semiconductor and Dimensional Metrology Division, says this calibration wasn't terribly difficult, but it was a little unusual because the tape that the course measurer wanted calibrated was 100 meters long, 40 meters longer than the NIST "tape tunnel," so they had to do the calibration in sections.

"The uncertainties associated with our laser interferometer system are very small," says Blackburn. "And by applying the proper tension on the tape to pull it straight and keeping the temperature at 20 °C, plus or minus 15 hundreths of a degree, we achieve uncertainties of 0.00018 meters, which meets or exceeds our customers' requirements in most cases."

Blackburn's group performs about 40 calibrations annually, mostly for the petroleum and measuring tape manufacturing industry. While the effort that goes into each calibration varies depending on several factors, including tape construction and tape length, most can be completed in a few hours.

measuring tape
Researchers calibrate measuring tapes of all types in the 60-meter long NIST tape tunnel.
Credit: NIST
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The IAAF chose David Katz of Finish Line Road Race Technicians, Inc., and his friend and collaborator Hugh Jones to help perform the measurements, and Katz in turn contacted NIST to perform the calibration of the tape that they used to calibrate their Jones Counters. After making the temperature corrections and compensations for the error that NIST found in the tape (13 mm over 100 meters), Katz and Jones found that their measurements of the marathon course disagreed by 1.3 to 2 meters over the entire distance.

"I was thrilled with the result," says Katz. "This level of agreement, with a difference of about 2 centimeters per mile, is pretty remarkable. This measurement was my gold medal."

This is not the first time that NIST has been asked to help out with Olympic-sized measurement problems. For instance, in 2002, NIST worked with Winter Olympics officials to calibrate and test the photoelectric timers used in bobsled and luge races, showing that they were accurate to within less than half a millisecond.**

Get Olympics fast facts and other measurements related to sports on the NIST website at www.nist.gov/pml/wmd/metric/olympic-facts.cfm.

* www.jonescounter.com/2.html
** See NIST Tech Beat for Jan. 2, 2002, at www.nist.gov/public_affairs/techbeat/tb2002_0102.htm#Time
Edited on Aug. 22, 2012, to use metric units in the first paragraph.

Media Contact: Mark Esser, mark.esser@nist.gov, 301-975-8735

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'Tuning' Graphene Drums Might Turn Conductors to Semiconductors

Tightening or relaxing the tension on a drumhead will change the way the drum sounds. The same goes for drumheads made from graphene, only instead of changing the sound, stretching graphene dramatically alters the material's electrical properties. Researchers working at the National Institute of Standards and Technology (NIST) and the University of Maryland have shown* that subjecting graphene to mechanical strain can mimic the effects of magnetic fields and create a quantum dot, an exotic type of semiconductor with a wide range of potential uses in electronic devices.

illustration of pseudomagnetic fields that confine grahene's electrons and create quntized quantum dot-like energy levels
NIST researchers showed that straining graphene membrane creates pseudomagnetic fields that confines the graphene's electrons and creates quantized quantum dot-like energy levels. The background is a false color image of the graphene drumheads made from a single layer of graphene over 1 micron-sized pits etched in a silicon dioxide substrate.
Credit: N. Klimov and T. Li, NIST/UMD

Graphene is a single layer of carbon atoms arranged in a honeycomb lattice. Pure graphene is a phenomenal conductor, transmitting electricity with little resistance at room temperature. But microelectronic devices depend on semiconductors that can be turned "on" and "off" because they have an energetic threshold beneath which they won't conduct electricity. This new work demonstrates that mechanical strain can be used to make tiny regions of graphite act like a classic semiconductor.

The research team suspended a sheet of graphene over shallow holes in a substrate of silicon dioxide—essentially making a set of graphene drumheads. In probing the drumheads with a scanning probe microscope, they found that the graphene rose up to meet the tip of the microscope— a result of the van der Waals force, a weak electrical force that creates attraction between objects that are very close to each other. Calculations by the University of Maryland group showed that the graphene should stretch into a peak, like the top of a circus tent.

The researchers discovered that they could tune the strain in the drumhead using the conducting plate upon which the graphene and substrate were mounted to create a countervailing attraction and pull the drumhead down. In this way, they could pull the graphene into or out of the hole below it.

Their measurements showed that changing the degree of strain changed the material's electrical properties. When they pulled the graphene membrane into the tent-like shape, the region at the apex acted just like a quantum dot, a type of semiconductor in which electrons are confined to a small region of space.

"Normally, to make a graphene quantum dot, you would have to cut out a nanosize piece of graphene," says NIST fellow Joseph Stroscio. "Our work shows that you can achieve the same thing with strain-induced pseudomagnetic fields. It's a great result, and a significant step toward developing future graphene-based devices."

More details are available in the June 21 NIST news announcement, "Graphene Drumheads Tuned to Make Quantum Dots" at www.nist.gov/cnst/drumheads_062112.cfm.

The work was a collaborative effort with the University of Maryland, College Park, and the Korea Research Institute of Standards and Science.

* N. Klimov, S. Jung, S. Zhu, T. Li, C. Wright, S. Solares, D. Newell, N. Zhitenev and J. Stroscio. Electromechanical properties of graphene drumheads. Science. Vol. 336 no. 6088 pp. 1557-1561 DOI: 10.1126/science.1220335. Published online before print June 21, 2012.

Media Contact: Mark Esser, mark.esser@nist.gov, 301-975-8735

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Not-So-Precious: Stripping Gold From AFM Probes Allows Better Measurement of Picoscale Forces

Gold is not necessarily precious—at least not as a coating on atomic force microscope (AFM) probes.

AFM
Artist's conception of JILA's advance in atomic force microscope (AFM) design. To measure picoscale forces in liquid, a AFM probe attaches to a molecule such as DNA and pulls, and the deflection of the probe is measured. JILA researchers found that probes with the gold coating removed (purple in the illustration) make measurements that are 10 times more stable and precise than those made with conventional gold-coated probes. Gold helps reflect the laser light but it can also potentially crack, age, and creep, which degrades its mechanical properties and reduces measurement precision.
Credit: Baxley/JILA
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JILA researchers found that removing an AFM probe's gold coating—until now considered helpful—greatly improved force measurements performed in a liquid, the medium favored for biophysical studies such as stretching DNA or unfolding proteins. As described in Nano Letters,* stripping the gold from the diving-board-shaped probe, or cantilever, with a brief chemical bath improved the precision and stability of force measurements about 10-fold. The advance is expected to quickly and broadly benefit the fields of biophysics and nanoscience.

JILA is a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder.

"What I find interesting about this experiment is it's so incredibly simple. It takes a minute to strip the gold off a commercial cantilever and you get a 10-fold improvement in force precision," says NIST/JILA physicist Thomas Perkins.

To measure forces at the molecular scale, an AFM's cantilever attaches to a molecule with its pointed end and pulls; the resulting deflection of the cantilever is measured. The forces are in the realm of piconewtons (pN), or trillionths of a newton. A unit of force, one newton is roughly the weight of a small apple.

Cantilevers are typically made of silicon or silicon nitride and coated with gold on both sides to reflect light. Perkins discovered the gold coating was a problem while his research group was probing the folding and unfolding of protein molecules over time periods of seconds to minutes. The group previously improved AFM position stability** and holds a related patent,*** but then discovered that the force was drifting. "It's counterintuitive," says Perkins. "Everyone has assumed you needed gold for the enhanced reflectivity, when in fact, gold is clearly the dominant source of force drift on short and long time scales."

"Gold exhibits a sort of complex elastic property in high-precision measurements," Perkins explains. "When you bend gold, it creeps a little bit, like silly putty. Further, the lore in the field is that gold can crack, it can age, and molecules can bind to it—all of which may change its mechanical properties. This problem is even worse when you do biological experiments in liquid."

AFM force measurements in liquid typically have had precision (error range) of plus or minus 5 to 10 pN. By stripping the gold JILA researchers reduced the error by 10 times, to about 0.5 pN for measurements on both short and long timescales. Researchers can now precisely measure fast processes, such as proteins folding and unfolding 50 times per second, over long time periods of several minutes. Significantly, the results were achieved with commercially available microscopes and cantilevers, so the practical benefits can be applied quickly for any AFM force measurements and imaging. AFM can now compete with optical traps and magnetic tweezers in terms of sensitivity.

The research was supported by the National Science Foundation and NIST.

* A.B. Churnside, R.M.A. Sullan, D.M. Nguyen, S.O. Case, M.S. Bull, G.M. King and T.T. Perkins. Routine and timely sub-piconewton force stability and precision for biological applications of atomic force microscopy. Nano Letters. Published online June 13.
** See the Mar. 24, 2009, NIST Tech Beat article, "Making a Point: Picoscale Stability in a Room-Temperature AFM" at www.nist.gov/public_affairs/tech-beat/tb20090324.cfm#afm.
*** U.S. Patent 7,928,409, April 19, 2011, Real-time, active picometer-scale alignment, stabilization and registration in one or more dimensions, T.T. Perkins, G.M. King and A.R. Carter.

Media Contact: Laura Ost, laura.ost@nist.gov, 303-497-4880

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First Observation of the Hall Effect in a Bose-Einstein Condensate

National Institute of Standards and Technology (NIST) researchers have observed for the first time the Hall effect in a gas of ultracold atoms. The Hall effect is an important interaction of magnetic fields and electric current more commonly associated with metals and semiconductors. Variations on the Hall effect are used throughout engineering and physics with applications ranging from automobile ignition systems to fundamental measures of electricity. The new discovery could help scientists learn more about the physics of quantum phenomena such as superfluidity and the quantum Hall effect.

Their paper appeared June 14, 2012, in the online version of the Proceedings of the National Academy of Sciences.*

animated gif of Hall Effect in BEC
Starting with a cloud of about 20,000 atoms, the researchers varied the trapping force, pushing the atoms together and pulling them apart, to simulate the movement of charge carriers in an alternating current. In response, the atoms begin to move in a manner mathematically identical to how charged particles experiencing the Hall effect would move--at right angles to both the direction of the "current" flow and the artificial magnetic field. This causes the tilting motion.
Credit: NIST

Discovered in 1879 by Edwin Hall, the Hall effect is easiest to visualize in a rectangular conductor like a copper plate when a current is flowing along its length. A magnetic field applied at a right angle to the electric current (down into the plate) deflects the path of the charge carriers in the current (electrons, for example) by inducing a force in the third direction at right angles to both the magnetic field and the current flow. This pushes the charge carriers toward one side of the plate and induces an electrical potential, or "Hall voltage." The Hall voltage can be used to measure the hidden internal properties of electrical systems, such as the concentration of the current carriers and the sign of their charge.**

"Cold atom systems are a great platform for studying complicated physics because they are nearly free of obscuring impurities, the atoms move much more slowly than electrons in solids, and the systems are much simpler," says NIST researcher Lindsay LeBlanc. "The trick is creating the conditions that will get the atoms to behave the right way."

Measuring the Hall effect in a Bose-Einstein condensate builds upon previous NIST work generating synthetic electric and magnetic fields. First, the group uses lasers to tie the atoms’ energy to their momentum, putting two internal states into a relationship called a superposition. This causes the electrically neutral atoms to act as if they are charged particles. With the cloud of about 20,000 atoms gathered into a loose ball, the researchers then cyclically vary the trapping force—pushing the atoms in the cloud together and pulling them apart—to simulate the movement of charge carriers in an alternating current. In response, the atoms begin to move in a manner that is mathematically identical to how charged particles experiencing the Hall effect would move, i.e., at right angles to both the direction of the "current" flow and the artificial magnetic field.

According to LeBlanc, measuring the Hall effect offers another tool for studying the physics of superfluidity, a low-temperature quantum-based condition where liquids flow without friction, as well as the so-called quantum Hall effect, where the ratio of the Hall voltage and the current through the material is quantized, allowing for the determination of fundamental constants.

* L.J. LeBlanc, K. Jimenez-Garcia, R.A. Williams, M.C. Beeler, A.R. Perry, W.D. Phillips and I.B. Spielman. Observation of a superfluid Hall effect. Proceedings of the National Academy of Science. Published online before print June 14, 2012, doi: 10.1073/pnas.1202579109.
** See, for example, www.nist.gov/pml/div683/hall_effect.cfm.

Media Contact: Mark Esser, mark.esser@nist.gov, 301-975-8735

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JILA Frequency Comb Helps Evaluate Novel Biomedical Decontamination Method

Like many new measurement tools, the laser frequency comb seemed at first a curiosity but has found more practical uses than originally imagined. The technique for making extraordinarily precise measurements of frequency has now moved beyond physics and optics to advance biomedicine by helping researchers evaluate a novel instrument that kills harmful bacteria without the use of liquid chemicals or high temperatures.

comb apparatus
This colorful apparatus is a key part of the JILA frequency comb instrument used to measure trace gases for biomedical applications. The beam from a powerful fiber laser is converted by a special crystal and other optics into two light waves at lower frequencies. The system can detect and measure the concentration of many different molecules based on how they absorb light in the mid-infrared region of the electromagnetic spectrum.
Credit: JILA
View hi-resolution image

Generated by ultrafast lasers, frequency combs precisely measure individual frequencies (colors) of light. Researchers at JILA, operated jointly by the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder, are using such a comb to identify specific molecules in gases based on which colors of light, or comb "teeth," are absorbed by the gas, and in what amounts.

Mark Golkowski, assistant professor of electrical engineering and bioengineering at the University of Colorado Denver, said JILA's comb measurements help explain for the first time how his sterilization technique inactivates bacteria, and thus will "help optimize solutions for the medical clinic where multi-drug resistant bacteria are a growing problem."

"JILA provided us the unique capability of an extremely sensitive measurement and one that also yields information about the interaction dynamics, since many molecules can be simultaneously observed on short time scales," Golkowski said.  

In a study described in a forthcoming paper,* Golkowski and colleagues conducted a variety of tests with an instrument that delivers an air stream of free radicals—highly reactive molecules—to quickly kill bacteria up to three meters away. The system achieved high-level disinfection of Staphylococcus aureus (a cause of pneumonia and other diseases) and Pseudomonas aeruginosa (often found on medical equipment) on surfaces such as plastic ID badges—a major source of pathogen transmission. The method also proved effective against difficult-to-eradicate spores of Bacillus atrophaes (found in soil) and biofilms of Escherichia coli (a cause of food poisoning).

JILA/NIST Fellow Jun Ye and two members of his research group used one of their frequency comb systems** to measure the concentrations of reactive molecules in the airstream—ozone, hydrogen peroxide, nitrous oxide, and nitrogen dioxide.

The comb system's capability to measure hydrogen peroxide is important, because the presence and concentration of this chemical is key to effective sterilization. But crucially, the comb technique also captures the complex chemical reactions in the sterilization system in real time. "The multiple and simultaneous reactions make numerical modeling of the chemical dynamics difficult, hence the need for direct measurement of simultaneous concentrations, a capability that the frequency comb spectroscopy uniquely provides," the paper states.

The remote sterilization system kills bacteria as quickly as competing treatments using bulky and expensive equipment, while also offering the advantages of low-cost hardware and flexibility of application, according to the paper. The JILA measurements are funded by NIST and the Air Force Office of Scientific Research.

* M. Gołkowski, C. Gołkowski, J. Leszczynski, S.R. Plimpton, P. Masłowski, A. Foltynowicz, J. Ye and B. McCollister. Hydrogen peroxide enhanced nonthermal plasma effluent for biomedical applications. IEEE Transactions on Plasma Science. Posted online as an Early Access Article. DOI: 10.1109/TPS.2012.2200910.
** See NIST Tech Beat article, "JILA Unveils Improved 'Molecular Fingerprinting' for Trace Gas Detection," October 13, 2010, at www.nist.gov/pml/div689/breath_101310.cfm.

Media Contact: Laura Ost, laura.ost@nist.gov, 303-497-4880

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Baldrige Award Applicants Can Now Receive Recognition for Best Practices

For the first time in the 25-year history of the Malcolm Baldrige National Quality Award, high-performing organizations that are candidates for the award will be eligible for recognition of their best practices in six of the seven Baldrige Criteria categories, even if they are not selected as a winner.

The 39 applicants for the 2012 Baldrige Award are currently being evaluated rigorously by an independent board of 478 examiners in the seven categories of the Baldrige Criteria for Performance Excellence: leadership; strategic planning; customer focus; measurement, analysis and knowledge management; workforce focus; operations focus; and results. Late this summer, organizations that distinguish themselves in the initial screening will be site visited by teams of examiners to verify information in the application and to clarify questions that come up during the review.

Based on the results of the site visits, the Baldrige Panel of Judges will recommend to the Secretary of Commerce which organizations should receive the 2012 Baldrige Award. From amongst the remaining site-visited applicants, the judges also may identify examples of best practices in the first six categories of the Baldrige Criteria for special recognition. A site-visited organization may be recognized for one or more category best practices. In each case, the organization will achieve the recognition based on its performance in that category and the results related to that performance.

“We added category recognition to the award process as another encouragement for organizations to continue their engagement with the Baldrige Program, and to provide others with useful best practices that might be missed because the applicants weren’t selected for the Baldrige Award,” said Harry Hertz, director of the Baldrige Performance Excellence Program.

These organizations will be acknowledged in the program for the Baldrige Award ceremony, their achievement highlighted on the Baldrige Program website, and their leaders asked to present at the annual Quest for Excellence conference. Previously, only Baldrige Award winners were identified after each award cycle.

Named after Malcolm Baldrige, the 26th Secretary of Commerce, the Baldrige Award was established by Congress in 1987. The award—managed by the National Institute of Standards and Technology (NIST) in collaboration with the private sector—promotes excellence in organizational performance, recognizes the achievements and results of U.S. organizations, and publicizes successful performance strategies. The award is not given for specific products or services. Since 1988, 90 organizations have received Baldrige Awards.

Thousands of organizations use the Baldrige Criteria for Performance Excellence to guide their operations, improve performance and get sustainable results. This proven improvement and innovation framework offers organizations an integrated approach to key management areas.

For more information, go to www.nist.gov/baldrige.

Media Contact: Michael E. Newman, michael.newman@nist.gov, 301-975-3025

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