Story Tips From the Department of Energy’s Oak Ridge National Laboratory, January 2012

Released: 18-Jan-2012 3:10 PM EST
Source Newsroom: Oak Ridge National Laboratory
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ENVIRONMENT -- Permafrost peril . . .

Carbon trapped in the top few meters of permafrost soils across nearly 19 million square kilometers of northern regions could be released at a rate of about two to five times greater than previous estimates. This is the conclusion of 41 international scientists who publish on various aspects of permafrost. “Studies suggest that there is about 1,700 billion tons of carbon in this upper portion of permafrost, which is twice as much as is now in the atmosphere and four times as much as cumulative fossil fuel emissions since the Industrial Revolution,” said Oak Ridge National Laboratory’s Daniel Hayes, who contributed to a Comment article published in Nature in December. A warming climate causes permafrost to thaw, rendering this frozen carbon vulnerable to decomposition and emissions to the atmosphere. A significant amount of this carbon could be released as methane, which is about 22 times more potent as a heat-trapping greenhouse gas than carbon dioxide.

BIOFUELS -- Coast Guard going green . . .

To comply with the mandate to increase the use of alternative fuels, the Coast Guard has enlisted the help of Oak Ridge National Laboratory researchers with expertise in fuels and engines. “The Coast Guard has decided to use biobutanol rather than ethanol to mix with gasoline in their smaller craft, and biodiesel rather than petroleum diesel in their larger engines,” said Tim Theiss, group leader of the Fuels, and Engines and Emissions Research Group Center. During the three-year project, researchers will focus on a number of tasks, including determining the maximum acceptable level of these renewable fuels with the marine engines and infrastructure necessary to operate in a saltwater environment. Since 1790, the Coast Guard has safeguarded America’s maritime interests and the environment.

MATERIALS -- Revealing artifacts’ secrets . . .

Bronze and brass artifacts excavated at the ancient city of Petra have been imaged in three dimensions using neutrons at the High Flux Isotope Reactor at Oak Ridge National Laboratory. Neutron imaging allows archeologists and historians otherwise unobtainable insights into the manufacturing techniques and lives of bygone cultures. The samples, all from Brown University, include an elaborate hanging bronze oil lamp, a large Roman coin, and a standing dog figure. Neutron imaging data from artifacts can reveal raw materials used, manufacturing techniques, the historical development of alloys and composite materials, and the geological origins of ores and clay. On the cultural side, researchers can learn about the activities of daily life that such objects served.

MATERIALS -- Unexpected excitations . . .

A clearer understanding of magnetic interactions in insulating materials can help in developing magnets for motors in electric vehicles and can enhance the performance of magnets in many other devices. Researchers expected that introducing atoms of a nonmagnetic material into a magnetic insulator would weaken the magnetic interactions in the material. But a team conducting experiments at the Spallation Neutron Source at Oak Ridge National Laboratory discovered that when the insulating material barium manganate was doped with atoms of nonmagnetic vanadium, the magnetic excitations in the doped material retained their strength. The work contributes to fundamental understanding of magnetic interactions in insulating materials.

SOFT MATTER -- Tracking cell death protein . . .

Cell death, or apoptosis, is a naturally occurring and necessary biological process. In apoptosis, the 92 amino acid BAX protein inserts itself into mitochondrial membranes, causing their contents to leak out and their eventual demise. Small-angle neutron scattering at Oak Ridge National Laboratory’s High Flux Isotope Reactor is showing biochemists how the protein tunnels its way into membranes. The research helps to understand defective apoptosis, that is, when too many cells die, or too few. This dysfunction has been implicated in diseases such as atrophy of limbs and organs, as well as in some cancers.

SOFT MATTER -- Biologically inspired solar cells . . .

Researchers at Oak Ridge National Laboratory’s High Flux Isotope Reactor are getting a leg up in their research from an ingenious “low-tech” lighting tool using LEDs that, when fixed to their samples and pushed directly into the neutron beam, illuminate the response of layers of cyanobacteria to changes in light. The neutron beam passes through a window, taking “pictures” of the response of the bacteria to variations in light from the attached LEDs. The studies, conducted at a small-angle neutron scattering instrument designed especially for biological research, are useful for developing biomimetic and bioanalytical solar cell devices and for demonstrating that chlorosomes are alternatives to other protein pigment complexes produced in photosynthetic organisms.

MATERIALS -- Heat-enhanced magnetism . . .

Researchers have long thought that magnetism and superconductivity are mutually exclusive. Now neutron scattering at the Wide Angular-Range Chopper Spectrometer at Oak Ridge National Laboratory’s Spallation Neutron Source has revealed a novel picture of magnetism in which localized atomic magnetism in the parent material of an iron-based superconductor gets a boost from the itinerant conduction electrons in the lattice. This boost increases the strength of magnetic fluctuations  with increasing temperature  the opposite of the expected behavior. Usually, magnetism fades when heated, as nonmagnetic states become thermally populated. The effect has not been anticipated by any theoretical work. The discoveries challenge scientists’ understanding of both superconductivity and magnetism.

CARBON -- Out with old, new . . .

Instead of relying on models to inform models, Oak Ridge National Laboratory ecologists and modelers are combining their efforts and using actual data to improve global models of carbon uptake and release. “Modelers know what mechanisms to look at that are useful to improve the models,” said Jeff Warren, ORNL physiological ecologist and member of the Partitioning in Trees and Soil research team. After using sophisticated techniques to study root and soil uptake during the summer of 2011, researchers found that most carbon being absorbed by roots was being released within a few days, which is common during a dry period. Even carbon stored in soil from years before the experiment was being released into the atmosphere. “By developing a more holistic understanding of carbon uptake and release, we can better inform global climate change models,” Warren said.


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