Eric Dahl (Credit: Fermilab)Dahl aims to burst the dark-matter bubble

Sometimes, when the day’s work is over, Eric Dahl sits in front of his computer and watches a live video of a clear vessel filled with a special liquid. He watches from a room on the sixth floor of Wilson Hall, the main building of DOE’s Fermi National Accelerator Laboratory in Illinois; the vessel is 700 miles away, in a lab buried more than a mile underground in a mine in Ontario.

Most of the time, the liquid isn’t doing much. Some days, though, Dahl sees a bubble, and one day, one of those bubbles might revolutionize our understanding of the universe by providing direct evidence for a new type of matter particle. Dahl, an assistant professor at Northwestern University and a scientist at Fermilab, is one member of a small team working on the Chicago Observatory for Underground Particle Physics experiment, which is using bubble chambers to search for signs of dark-matter particles.

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This photo shows an array of 1-mm-wide by 2-cm-long single-crystal organic semiconductor. The neatly-aligned blue strips are what provide greater electric charge mobility. The Stanford logo shown here is the same size as a dime. (Credit: Y. Diao et al.)Printing innovations provide 10-fold improvement in organic electronics

Through innovations to a printing process, researchers have made major improvements to organic electronics—a technology in demand for lightweight, low-cost solar cells, flexible electronic displays and tiny sensors. The printing method is fast and works with a variety of organic materials to produce semiconductors of strikingly higher quality than what has so far been achieved with similar methods.

Organic electronics have great promise for a variety of applications, but even the highest quality films available today fall short in how well they conduct electrical current. The team at DOE's SLAC National Accelerator Laboratory and Stanford University have developed a printing process they call FLUENCE—fluid-enhanced crystal engineering—that for some materials results in thin films capable of conducting electricity 10 times more efficiently than those created using conventional methods.

"Even better, most of the concepts behind FLUENCE can scale up to meet industry requirements,” said Ying Diao, a SLAC/Stanford postdoctoral researcher and lead author of the study, which appeared today in Nature Materials.

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See also…

DOE Pulse
  • Number 392  |
  • July 8, 2013
  • New ultra-efficient HPC data center debuts

    Steve Hammond, director of NREL's Computational Science Center, stands in front of air-cooled racks in the high performance computing (HPC) data center in the Energy Systems Integration Facility (ESIF). The rest of the system will be built out this summer using warm-water liquid cooling to reach an annualized average power usage effectiveness (PUE) rating of 1.06 or better. Credit: Dennis Schroeder Scientists and researchers at DOE's National Renewable Energy Laboratory (NREL) are constantly innovating, integrating novel technologies, and "walking the talk."

    When it came time for the lab to build its own high performance computing (HPC) data center, the NREL team knew it would have to be made up of firsts: The first HPC data center dedicated solely to advancing energy systems integration, renewable energy research, and energy efficiency technologies. The first petascale HPC to use warm-water liquid cooling and reach an annualized average power usage effectiveness (PUE) rating of 1.06 or better.

    To accomplish this, NREL worked closely with industry leaders to track rapid technology advances and to develop a holistic approach to data center sustainability in the lab's new Energy Systems Integration Facility (ESIF).

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  • New imaging tool directly measures liquid surfaces

    The schematic of a vacuum compatible aqueous SIMS device. Insert shows the secondary H- and Si- ion images of this aperture. Designed and fabricated at DOE’s Pacific Northwest National Laboratory, a one-of-a-kind liquid probe continuously pumps liquid samples through a gold-coated microfluidic chamber, presenting these volatile liquids to scientific instruments for thorough analysis. The device’s extremely narrow channel provides high linear velocity at the detection window and helps overcome the liquids' tendency to vaporize. Instruments access the liquid via an open viewing port. Tests with electron microscopes and time-of-flight secondary ion mass spectrometers prove the device can continuously present complex liquids for up to 8 hours.

    "Our flow cell opens a window to observe interactions between liquid/solids and liquid surfaces, which are relevant to liquid/solid heterogeneous catalysis and energy storage techniques," said Dr. Xiao-Ying Yu at PNNL, who worked on the study.

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  • Exposure to air transforms gold alloys into catalytic nanostructures

    Left: Multiple gold-indium alloy nanoparticles at room temperature. Right: One nanoparticle's crystalline gold-indium core surrounded by the amorphous catalytic oxide shell.Gold bars may signify great wealth, but the precious metal packs a much more practical punch when shrunk down to just billionths of a meter. Unfortunately, unlocking gold's potential often requires complex synthesis techniques that produce delicate structures with extreme sensitivity to heat.

    Now, scientists at Brookhaven Lab have discovered a way to make uniquely structured gold-indium nanoparticles that combine high stability, great catalytic potential, and a simple synthesis process. The new nanostructures might enhance many commercial and industrial processes, including acting as an efficient material for catalytic converters in cars.

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  • Detecting homemade explosives, not toothpaste

    Sandia Labs researcher Chris Brotherton checks tiny sensors in a test fixture, where he exposes them to different environments and measures their response to see how they perform. Brotherton is principal investigator on a project aimed at detecting a common type of homemade explosive made with hydrogen peroxide. (Photo by Randy Montoya) Sandia National Laboratories researchers want airports, border checkpoints and others to detect homemade explosives made with hydrogen peroxide without nabbing people whose toothpaste happens to contain peroxide.

    That’s part of the challenge faced in developing a portable sensor to detect a common homemade explosive called a FOx (fuel/oxidizer) mixture, made by mixing hydrogen peroxide with fuels, said Chris Brotherton, principal investigator for a Sandia research project on chemiresponsive sensors. The detector must be able to spot hydrogen peroxide in concentrations that don’t also raise suspicions about common peroxide-containing products.

    “Hydrogen peroxide explosives are a challenge because they are dangerous, but there are so many personal hygiene products that have hydrogen peroxide in them that the false positive rate is very high,” Brotherton said.

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  • Wireless project can improve DOE, NNSA secure communications

    SRS hot cell While wireless technology has become commonplace for many applications, concerns about security have traditionally prevented its use for transmitting data that is not intended for public disclosure. A project at the DOE’s Savannah River National Laboratory (SRNL), however, is combining the benefits of wireless networks with security levels suitable for even classified data.

    SRNL has collaborated with the National Security Agency (NSA) on a design for classified data transmission, without the use of the traditional Type 1 encryption products. The new secure wireless network design could be used for sensors across the DOE complex, in addition to uses by other federal agencies and industrial control systems at critical manufacturing facilities across the nation.

    The development has reached a major milestone with NSA’s approval of prototype hardware for use in certain classified communication operations. The approval of this prototype hardware marks the culmination of the first phase of a project that began four years ago with preliminary scoping to understand the needs and existing technologies.

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