Tag Archives: berkeley lab

How Computers Push on the Molecules They Simulate

By Guest PostJanuary 9, 2013Scienceacceleration, albert einstein, algorithm, analytical results, artifacts, atoms and molecules, behavior, Berkeley, berkeley lab, calculation, california, california institute, chemical fuel, collide, computer method, conserve energy, david sivak, digital representation, digitize time, dna repair, driving force, effective friction, energy dense, equation, error, finite time steps, fluid, french physicist, gavin crooks, john chodera, langevin dynamics, model brownian motion, modeling molecular system, modern computer, molecular machines, molecular scale motion, molecule, momentum, natural system, nonequilibrium driving force, nonequilibrium statistical mechanics, particle, passage of time, paul langevin, photosynthesis, pollen grain, qb3, quantitative biosciences, quantum mechanics, real world, simulation, source, tenacious errors, theoretical method, thermal energy, toy models, university, velocity, water, water molecules

Berkeley Lab bioscientists and their colleagues decipher a far-reaching problem in computer simulations

Because modern computers have to depict the real world with digital representations of numbers instead of physical analogues, to simulate the continuous passage of time they have to digitize time into small slices. This kind of simulation is essential in disciplines from medical and biological research, to new materials, to fundamental considerations of quantum mechanics, and the fact that it inevitably introduces errors is an ongoing problem for scientists.

Scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have now identified and characterized the source of tenacious errors and come up with a way to separate the realistic aspects of a simulation from the artifacts of the computer method. The research was done by David Sivak and his advisor Gavin Crooks in Berkeley Lab’s Physical Biosciences Division and John Chodera, a colleague at the California Institute of Quantitative Biosciences (QB3) at the University of California at Berkeley. The three report their results in Physical Review X. (more…)

A New Way to Study Permafrost Soil, Above and Below Ground

By Guest PostJanuary 6, 2013Environmentarctic landscape, arctic tundra, atmosphere, barrow region, berkeley lab, carbon dioxide, cessna aircraft, climate change, electrical resistance tomography, electromagnetic data, geophysical measurements, greenhouse gasses, ground penetrating radar, large spatial scales, lidar, lidar airborne measurements, methane, microtopography, ngee arctic project, permafrost layer, permafrost soils, polygons, remote sensing device, remote sensing tools, surface topography, susan hubbard, terrestrial ecosystem, trapped carbon

Berkeley Lab research could lead to a better understanding of the Arctic ecosystem’s impact on the planet’s climate

What does pulling a radar-equipped sled across the Arctic tundra have to do with improving our understanding of climate change? It’s part of a new way to explore the little-known world of permafrost soils, which store almost as much carbon as the rest of the world’s soils and about twice as much as is in the atmosphere.

The new approach combines several remote-sensing tools to study the Arctic landscape—above and below ground—in high resolution and over large spatial scales. It was developed by a group of researchers that includes scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). (more…)

Boosting Galactan Sugars Could Boost Biofuel Production

By Guest PostDecember 23, 2012Environmentai oikawa, april liwanag, arabidopsis thaliana, atmosphere, berit ebert, berkeley lab, bioenergy fuel crops, biofuels, carbon neutral, carsten rautengarten, cellulosic biomass, denmark, diesel, emilie rennie, enzyme, ethanol, ferment, fuels, galactan, galactan synthase, galactose, gals1, gals2, gals3, gasoline, gt92 enzyme, gt92 proteins, henrik scheller, jet fuels, mads clausen, mathias andersen, mechanical stress, miscanthus, overexpressors, pentoses, plant cell walls, polymer, six carbon sugar, snowfall, switchgrass, technical university, wind, yeast, yves verhertbruggen, β galactan synthase

Collaboration at JBEI Identifies the First Enzyme Linked to Galactan Synthesis

Galactan is a polymer of galactose, a six-carbon sugar that can be readily fermented by yeast into ethanol and is a target of interest for researchers in advanced biofuels produced from cellulosic biomass. Now an international collaboration led by scientists at the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI) has identified the first enzyme capable of substantially boosting the amount of galactan in plant cell walls.

Unlike ethanol, advanced biofuels synthesized from the sugars in plant cells walls could replace gasoline, diesel and jet fuels on a gallon-for-gallon basis and be dropped into today’s engines and infrastructures with no modifications required. Also, adanced biofuels have the potential to be carbon-neutral, meaning they could be burned without adding excess carbon to the atmosphere. Among the key challenges to making advanced biofuels cost competitive is finding ways to maximize the amount of plant cell wall sugars that can be fermented into fuels. (more…)

Flexing Fingers for Micro-Robotics: Berkeley Lab Scientists Create a Powerful, Microscale Actuator

By Guest PostDecember 18, 2012Scienceartificial muscles, beckoning finger, berkeley lab, chromium metal layer, chun cheng, electron, electronic behaviors, flex, human muscle cells, junqiao wu, kai liu, kevin wang, metal, microactuator, microfluidics, micron, microscale actuator, natural application, oxide material, phase transitions, phenomena, phillip m. duxbury, piezoelectric device, piezoelectric technology, ramamoorthy ramesh, subhendra d mahanti, Technology, temperature variation, university of california, vanadium dioxide, zhenting cheng

Berkeley, Calif., Dec. 2012 — Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley, have developed an elegant and powerful new microscale actuator that can flex like a tiny beckoning finger. Based on an oxide material that expands and contracts dramatically in response to a small temperature variation, the actuators are smaller than the width of a human hair and are promising for microfluidics, drug delivery, and artificial muscles.

“We believe our microactuator is more efficient and powerful than any current microscale actuation technology, including human muscle cells,” says Berkeley Lab and UC Berkeley scientist Junqiao Wu. “What’s more, it uses this very interesting material—vanadium dioxide—and tells us more about the fundamental materials science of phase transitions.” (more…)

Seeing in Color at the Nanoscale

By Guest PostDecember 12, 2012Scienceafm, alex weber bargioni, atomic force microscope, atomic microscopy, berkeley lab, color, conversion, data, diederik wiersma, electric energy, electrons, fabrication, far field light, francesca intonti, frank ogletree, geometries, imagery, indium phosphide nanowires, james schuck, jeffrey bokor, mauro meli, multidimensional, nano optics, nanoscale, nanoscale objects, nanoscience, nanospectroscopic imaging, optical fiber, optical spectroscopy, optoelectronic properties, photons, plasmons, shaul aloni, solar, stephano cabrini, sub nanoscale resolution, topological map, wei bao

Berkeley Lab scientists develop a new nanotech tool to probe solar-energy conversion

If nanoscience were television, we’d be in the 1950s. Although scientists can make and manipulate nanoscale objects with increasingly awesome control, they are limited to black-and-white imagery for examining those objects. Information about nanoscale chemistry and interactions with light—the atomic-microscopy equivalent to color—is tantalizingly out of reach to all but the most persistent researchers.

But that may all change with the introduction of a new microscopy tool from researchers at the Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) that delivers exquisite chemical details with a resolution once thought impossible. The team developed their tool to investigate solar-to-electric energy conversion at its most fundamental level, but their invention promises to reveal new worlds of data to researchers in all walks of nanoscience. (more…)

More Potent than Carbon Dioxide, Nitrous Oxide Levels in California May be Nearly Three Times Higher Than Previously Thought

By Guest PostDecember 9, 2012Environmentagricultural production, atmospheric measurement, berkeley lab, biogeochemical process, bottom up inventory, california, carbon dioxide, CO2, cycle of emissions, edgar, emission, environmental condition, estimate, factor, fossil fuel, greenhouse gas, laughing gas, level, marc fischer, methane, model prediction, moisture, new method, nitrogen fertilizer, nitrous oxide, noaa, temperature, total n2o, type of soil, walnut grove

Berkeley Lab researchers devise a new method to estimate state’s greenhouse gas emissions.

Using a new method for estimating greenhouse gases that combines atmospheric measurements with model predictions, Lawrence Berkeley National Laboratory (Berkeley Lab) researchers have found that the level of nitrous oxide, a potent greenhouse gas, in California may be 2.5 to 3 times greater than the current inventory.

At that level, total N₂O emissions—which are believed to come primarily from nitrogen fertilizers used in agricultural production—would account for about 8 percent of California’s total greenhouse gas emissions. The findings were recently published in a paper titled “Seasonal variations in N₂O emissions from central California” in Geophysical Research Letters. Earlier this year, using the same methodology, the researchers found that levels of methane, another potent greenhouse gas, in California may be up to 1.8 times greater than previous estimates. (more…)

Climate Change Study Strengthens Link to Human Activities

By Guest PostDecember 5, 2012EnvironmentAntarctica, Arctic, atmospheric temperature, benjamin santer, berkeley lab, carbon dioxide, cfcs, chlorofluorocarbons, climate change, climate models, coolants, el niño, evidence, greenhouse gases, higgs boson, human factors, human influence, llnl, michael wehner, pacific decadal oscillation, phenomena, propellants, satellite data, simulations, southern oscillation, stratospheric temperature, tropospheric, tropospheric warming

Computer Models, Satellite Data Reveal Clearest Evidence Yet of Human Influence on Changing Temperatures

New research shows some of the clearest evidence yet of a discernible human influence on atmospheric temperature.

Published online in the Nov. 29 early edition of the Proceedings of the U.S. National Academy of Sciences, the study compared 20 of the latest climate models against 33 years of satellite data. When human factors were included in the models, they followed the pattern of temperature changes observed by satellite. When the same simulations were run without considering human influences, the results were quite different.

“We can only match the satellite record when we add in human influences on the atmosphere,” said Michael Wehner, a research scientist at Lawrence Berkeley National Laboratory (Berkeley Lab) Computational Research Division and a coauthor of the article, which involved colleagues from 16 other organizations and was led by Benjamin Santer, an atmospheric scientist at Lawrence Livermore National Laboratory (LLNL). (more…)

The Installed Price of Solar Photovoltaic Systems in the U.S. Continues to Decline at a Rapid Pace

By Guest PostNovember 27, 2012Environmentberkeley lab, business process, commercial, customer site, galen barbose, module cost, power system, price, pv, pv module, pv systems, ryan wiser, solar photovoltaic, tracking the sun, united states

Berkeley, CA — The installed price of solar photovoltaic (PV) power systems in the United States fell substantially in 2011 and through the first half of 2012, according to the latest edition of Tracking the Sun, an annual PV cost-tracking report produced by the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).

The median installed price of residential and commercial PV systems completed in 2011 fell by roughly 11 to 14 percent from the year before, depending on system size, and, in California, prices fell by an additional 3 to 7 percent within the first six months of 2012. These recent installed price reductions are attributable, in large part, to dramatic reductions in PV module prices, which have been falling precipitously since 2008. (more…)