William H. Goldstein has been named director of Lawrence Livermore National Laboratory. Appointed with the concurrence of the Department of Energy (DOE) and the National Nuclear Security Administration (NNSA), Goldstein is the 12th director of the Laboratory since it was established in 1952. He will also serve as president of Lawrence Livermore National Security, LLC (LLNS), which manages the Laboratory for DOE and NNSA.
In announcing the selection, LLNS President Norman Pattiz said Goldstein was chosen “because of his proven scientific leadership and senior management experience across a broad range of Laboratory programs, his passion for the Lab’s mission and people, and his ability to strategically manage the breadth of Livermore’s science and technology capabilities and operations to meet critical national security needs. He is a respected and trusted scientist among Laboratory managers and employees and with the DOE, NNSA, and other key government sponsors and academic and industrial partners.”
A 29-year Laboratory employee, Goldstein previously served as Livermore’s deputy director for Science and Technology and as associate director for Physical and Life Sciences. His contributions to stockpile stewardship include generating data that underlie advanced codes and simulations. In addition, he led the creation of Livermore’s Jupiter Laser Facility and, in 2006, oversaw completion of the Titan laser platform. Goldstein received a Ph.D. in theoretical physics from Columbia University and a bachelor’s degree in physics from Swarthmore College. He is a fellow of the American Association for the Advancement of Science and, in 1994, was honored with the DOE Weapons Recognition of Excellence Award.
Contact: Lynda L. Seaver (925) 423-3103 (firstname.lastname@example.org).
An international research team led by Livermore climate scientist Benjamin Santer found that volcanic eruptions in the early part of the 21st century have cooled the planet, partly offsetting the warming produced by greenhouse gases. In the February 23, 2014, edition of Nature Geoscience, the team reported that most climate models have not accurately accounted for this cooling effect.
Despite continuing increases in atmospheric levels of greenhouse gases, the global mean temperatures at the planet’s surface and in the troposphere (the lowest layer of Earth’s atmosphere) have shown little warming since 1998. The Livermore-led collaboration explored whether increased amounts of volcanic aerosol in the stratosphere (the layer above the troposphere) could be a factor in the warming “slowdown” because these aerosols reflect some of the incoming sunlight back into space.
The researchers performed two statistical tests to determine whether recent volcanic eruptions have cooling effects that can be distinguished from the intrinsic variability of the climate. They found evidence for significant correlations between observed levels of volcanic aerosols, satellite-based estimates of lower temperatures in the troposphere, and the amount of sunlight reflected back to space by the aerosol particles.
The team’s research was funded by DOE’s Office of Biological and Environmental Science in the Office of Science. The study included scientists from Remote Sensing Systems, Massachusetts Institute of Technology, NASA’s Goddard Institute for Space Studies, and the Canadian Centre for Climate Modeling and Analysis.
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Working at Deutsches Elektronen-Synchrotron (DESY) in Hamburg, Germany, an international collaboration that included Livermore researchers simulated the lower atmospheric layers of giant gas planets such as Jupiter and Saturn. The team’s findings show how liquid hydrogen becomes a plasma. The research also enhances understanding of the plasma’s thermal conductivity and its internal energy exchange, both important components of planetary models.
The atmosphere of gas giants consists mainly of hydrogen, the most abundant chemical element in the universe. “Some of hydrogen’s properties at extreme conditions remain uncertain despite our very good theoretical models,” says Livermore physicist Tilo Doeppner, a coauthor of the team’s paper appearing in the March 12, 2014, online edition of Physical Review Letters . The researchers chose liquid hydrogen because its mass density is similar to that found in the lower atmosphere of giant gas planets. Using FLASH, the x-ray laser at DESY, the scientists heated the liquid hydrogen almost instantaneously, from –253°C to about 12,000°C, and observed characteristics of the heating process through the increase in the x-ray scattering signal.
The x-ray laser pulse initially heats only electrons. These electrons slowly transfer their energy to protons, which are about 2,000 times heavier, until a thermal equilibrium is reached. During the process, hydrogen’s molecular bonds break, forming a plasma of electrons and protons. Although this process takes many thousands of collisions between electrons and protons, the studies showed that the thermal equilibrium is attained in just under one-trillionth of a second.
Contact: Tilo Doeppner (925) 422-2147 (firstname.lastname@example.org).
Research by scientists from Lawrence Livermore and the Joint BioEnergy Institute (JBEI) suggests that a type of bacterial resistance may lead to more efficient production of biofuels. The team identified the genetic origin of bacterial resistance to an ionic liquid (a salt in the liquid state) and introduced it into a strain of Escherichia coli, a bacterium used to produce advanced biofuels.
“Ionic liquids are potent solvents for extracting cellulose from biomass so that it can be broken down into sugars,” says Livermore biochemist Michael Thelen, who also works at JBEI. “Microbes then use the sugars to make new liquid fuels that could replace gasoline or diesel.”
Using an approach devised by Thomas Ruegg, a graduate student from Basel University, the team identified two genes in Enterobacter lignolyticus—a soil bacterium that is native to a tropical rainforest in Puerto Rico and is tolerant to specific ionic liquids. When the genes were transferred as a module into an E. coli biofuel host, they conferred the tolerance E. coli needed to grow well in the presence of toxic concentrations of ionic liquids. The module thus enhanced production of a terpene-based biofuel.
“The genetic module encodes both a membrane transporter and its transcriptional regulator,” says Ruegg. While a pump exports ionic liquids from the cell, the substrate-inducible regulator maintains the appropriate level of the pump so that the microbe can grow normally either in the presence or absence of ionic liquid. The results, published in the March 26, 2014, edition of Nature Communications, are likely to eliminate a bottleneck in JBEI’s biofuels production strategy, which relies on ionic liquid as a pretreatment for cellulosic biomass.
Contact: Michael Thelen (925) 422-6547 (email@example.com).
A collaboration involving scientists from Lawrence Livermore, the Feinstein Institute for Medical Research, and University of California campuses at Davis and Merced has found that single-wall carbon nanotubes (SWNTs) can help with tissue healing and repair. Carbon nanotubes are cylindrical nanostructures of carbon used in applications ranging from biology to optics to material science.
The researchers hypothesized that a suitably treated SWNT nanocomposite matrix would provide an improved substrate for growing chondrocytes—cells for producing and maintaining healthy cartilage. To test this hypothesis, they covered the surfaces of SWNTs with carboxyl molecular groups and combined them with tissues. Results from the study indicate that chondrocytes tolerate functionalized SWNTs well, with minimal evidence for cell toxicity. The biomechanical properties of tissues containing the nanotubes were improved relative to the control tissues. More studies are needed to determine if these properties are maintained in vivo, but the results indicate that nano-based substrates could one day provide alternative approaches for treating osteoarthritis and other cartilage defects in humans.
The team’s research was funded by a Lawrence Fellowship awarded to project lead Nadeen Chahine of the Feinstein Institute and by Livermore’s Laboratory Directed Research and Development Program. Research results appeared in the March 2014, edition of Tissue Engineering Part A.
Contact: Gabriela Loots (925) 423-0923 (firstname.lastname@example.org).