Tag Archives: berkeley lab

Forcing the Molecular Bond Issue

By Guest PostSeptember 6, 2012Scienceadsorb, aerosol droplets, aleksandr noy, antibody, berkeley lab, binding free energy, biosensing assay, data, dfs, dynamic force spectroscopy, energy barrier, force spectra, formation, interaction, intermolecular bond, jim deyoreo, material, molecular bond, molecular foundry, molecular system, molecule, nanoscience center, nonlinear force, property, raymond friddle, rupture, single bond model, standard model, synthetic analogue, synthetic polymer, torsional force

New and Improved Model of Molecular Bonding from Researchers at Berkeley Lab’s Molecular Foundry

Material properties and interactions are largely determined by the binding and unbinding of their constituent molecules, but the standard model used to interpret data on the formation and rupturing of molecular bonds suffers from inconsistencies. A collaboration of researchers led by a scientist at the U.S Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has developed a first-of-its-kind model for providing a comprehensive description of the way in which molecular bonds form and rupture. This model enables researchers to predict the “binding free energy” of a given molecular system, which is key to predicting how that molecule will interact with other molecules.

“Molecular binding and unbinding events are much simpler than we have been led to believe from the standard model over the past decade,” says Jim DeYoreo, a scientist with the Molecular Foundry, a DOE nanoscience center at Berkeley Lab who was one of the leaders of this research. “With our new model, we now have a clear means for measuring one of the most important parameters governing how materials and molecules bind together.” (more…)

Supernovae of the Same Brightness, Cut From Vastly Different Cosmic Cloth

By Guest PostSeptember 1, 2012Sciencealex filippenko, andy howell, ben dilday, berkeley lab, constellation lynx, cosmic distance, discovery, esnet, exploding stars, hawaii, jeffrey silverman, joshua bloom, keck telescope, las cumbres observatory, lcogt, lick observatory, light year, milky way galaxy, NASA, origin, palomar transient factory, peter nugent, progenitor systems, ptf, ptf 11kx, red giant star, rs ophiuchi, samuel oschin, shane telescope, sky, sn 2011fe, southern california, spectroscopy, supernova, target of opportunity, telescope, too, type 1a, universe, university of california

Berkeley Lab researchers make historic observation of rare Type 1a Supernova

Exploding stars called Type 1a supernova are ideal for measuring cosmic distance because they are bright enough to spot across the Universe and have relatively the same luminosity everywhere. Although astronomers have many theories about the kinds of star systems involved in these explosions (or progenitor systems), no one has ever directly observed one—until now.

In the August 24 issue of Science, the multi-institutional Palomar Transient Factory (PTF) team presents the first-ever direct observations of a Type 1a supernova progenitor system. Astronomers have collected evidence indicating that the progenitor system of a Type 1a supernova, called PTF 11kx, contains a red giant star. They also show that the system previously underwent at least one much smaller nova eruption before it ended its life in a destructive supernova. The system is located 600 million light years away in the constellation Lynx. (more…)

Form, Function and Folding: In Collaboration with Berkeley Lab, a Team of Scientists Move Toward Rational Design of Artificial Proteins

By Guest PostAugust 26, 2012Scienceamino acid, barney yoo, berkeley lab, bioinspired nanomaterial, blind structure, function, glenn butterfoss, ilya chorny, jonathan jaworski, ken dill, kent kirshenbaum, modeling, molecular foundry, n alkyl, natural selection, new york university, peptoid molecule, peptoid trimers, prediction, protein, protein sequence, qm, qm calculation, remd, richard bonneau, ronald zuckermann, stony brook university, structure, synthetic cousin, temple university, vincent voelz, xray crystallography

In the world of proteins, form defines function. Based on interactions between their constituent amino acids, proteins form specific conformations, folding and twisting into distinct, chemically directed shapes. The resulting structure dictates the proteins’ actions; thus accurate modeling of structure is vital to understanding functionality.

Peptoids, the synthetic cousins of proteins, follow similar design rules. Less vulnerable to chemical or metabolic breakdown than proteins, peptoids are promising for diagnostics, pharmaceuticals, and as a platform to build bioinspired nanomaterials, as scientists can build and manipulate peptoids with great precision. But to design peptoids for a specific function, scientists need to first untangle the complex relationship between a peptoid’s composition and its function-defining folded structure. (more…)

Doing Science to Teach Science

By Guest PostAugust 22, 2012Education, Scienceallen boltz, ashok gadgil, autumn chapman, berkeley darfur stove, berkeley lab, brito guedes, california, cookstove, dna repair, high school, iisme, jill fuss, monique, nigel quinn, particulate, pe teacher, polymerase chain reactions, san joaquin basin, Science, skin deformities, sophomore chemistry, teacher, thermodynamic

A summer of research at Berkeley Lab gives high school teachers a jump start on science.

High school science teachers face a perennial problem: how to make science real and exciting to their students. But for Berkeley High School teacher Allen Boltz, who spent eight weeks at Lawrence Berkeley National Laboratory working in a research lab, he will be returning to his classroom this fall a near rock star.

“This experience gives a lot of credibility to the teaching profession,” he said. “To my students, me doing research here would be the equivalent to their PE teacher being a professional athlete.” (more…)

A Direct Look at Graphene

By Guest PostAugust 5, 2012Scienceandrey shytov, atom, berkeley lab, carbon atom, coulomb potential, dirac quasiparticles, electrical conductor, electron, factor, graphene, graphene device, graphene properties, hexagonally patterned, honeycomb, lattice, michael crommie, paul dirac, speed of light, stm, victor brar, yang wang

Direct Imaging by Berkeley Lab Researchers Confirms the Importance of Electron-Electron Interactions in Graphene

Perhaps no other material is generating as much excitement in the electronics world as graphene, sheets of pure carbon just one atom thick through which electrons can race at nearly the speed of light – 100 times faster than they move through silicon. Superthin, superstrong, superflexible and superfast as an electrical conductor, graphene has been touted as a potential wonder material for a host of electronic applications, starting with ultrafast transistors. For the vast potential of graphene to be fully realized, however, scientists must first learn more about what makes graphene so super. The latest step in this direction has been taken by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley.

Michael Crommie, a physicist who holds joint appointments with Berkeley Lab’s Materials Sciences Division and UC Berkeley’s Physics Department, led a study in which the first direct observations at microscopic lengths were recorded of how electrons and holes respond to a charged impurity – a single Coulomb potential – placed on a gated graphene device. The results provide experimental support to the theory that interactions between electrons are critical to graphene’s extraordinary properties. (more…)

Measuring the “Other” Greenhouse Gases: Higher Than Expected Levels of Methane in California

By Guest PostJune 16, 2012Environmentanthropogenic, atmospheric lifetime, berkeley lab, black carbon, california, carb, carbon dioxide, central valley, ch4 emissions, climate pollutant, CO2, coal mines, decomposition, environment policy, fossil fuel, fraction, global warming, greenhouse gas, halocarbon gases, landfills, livestock ranches, man made source, map, marc l fischer, methane, methane emissions, methane signals, natural sources, nitrous oxide, noaa, organic matter, refrigerants, sacramento, seongeun jeong, soot, sound energy, spatial, temporal resolution, united states, walnut grove

Berkeley Lab scientists develop new method for evaluating short-lived pollutants.

New research from Lawrence Berkeley National Laboratory (Berkeley Lab) has found that levels of methane—a potent greenhouse gas emitted from many man-made sources, such as coal mines, landfills and livestock ranches—are at least one-and-a-half times higher in California than previously estimated.

Working with scientists from the National Oceanic and Atmospheric Administration (NOAA) Berkeley Lab scientists Marc L. Fischer and Seongeun Jeong combined highly accurate methane measurements from a tower with model predictions of expected methane signals to revise estimated methane emissions from central California. They found that annually averaged methane emissions in California were 1.5 to 1.8 times greater than previous estimates, depending on the spatial distribution of the methane emissions. (more…)

A New Way of Looking at Photosystem II

By Guest PostJune 14, 2012Sciencealgae, angstroms, bacteria, berkeley lab, carbon dioxide, catalytic cycle, critical formation, cryogenic freezing, electrochemical energy, electrons, femtosecond timescale, femtosecond x ray pulses, green, green plants, hydrogen atom, hydrogen ions, jan kern, junko yano, knowledge, lcls, microcrystals, nicholas sauter, oxidation states, oxygen molecules, paul adams, photooxidation, photosynthesis, photosystem ii, protein crystallography, proteins, protons, renewable energy, resolution, slac, solar energy, synchrotron radiation, terabytes of data, uwe bergmann, vittal yachandra, water, xray diffraction, xrays

Berkeley Lab and SLAC Researchers Study Key Protein Complex Crucial to Photosynthesis

Future prospects for clean, green, renewable energy may hinge upon our ability to mimic and improve upon photosynthesis – the process by which green plants, algae and some bacteria convert solar energy into electrochemical energy. An artificial version of photosynthesis, for example, could use sunlight to produce liquid fuels from nothing more than carbon dioxide and water. First, however, scientists need a better understanding of how a large complex of proteins, called photosystem II, is able to split water molecules into oxygen, electrons and hydrogen ions (protons). A new road to reaching this understanding has now been opened by an international team of researchers, led by scientists at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and SLAC National Accelerator Laboratory.

Using ultrafast, intensely bright pulses of X-rays from SLAC’s Linac Coherent Light Source (LCLS), the research team produced the first ever images at room temperature of microcrystals of the photosystem II complex. Previous imaging studies, using X-rays generated via synchrotron radiation sources, required cryogenic freezing, which alters the samples. Also, to catalyze its reactions, photosystem II relies upon an enzyme that contains a manganese-calcium cluster that is highly sensitive to radiation. With the high-intensity femtosecond X-ray pulses of the LCLS, the research team was able to record intact images of these clusters before the radiation destroyed them. (more…)

A New Tool to Attack the Mysteries of High-Temperature Superconductivity

By Guest PostJune 8, 2012Scienceabsolute zero, advanced light source, alessandra lanzara, als, band structure, bardeen cooper schrieffer, bcs theory, beams of xrays, Berkeley, berkeley lab, bi2212, christopher smallwood, conventional superconductors, cooper pairs, dung hai lee, electric current, electric grids, electrons, energy savings, femtosecond scale pulses, high tc, high temperature, joseph orenstein, msd, quasiparticles, relaxation process, resistance, superconductivity, synchrotron light sources, through frequency, transmission, ultrafast laser arpes, university of california

Berkeley Lab researchers use an ultrafast laser to better understand high-temperature superconductors

Superconductivity, in which electric current flows without resistance, promises huge energy savings – from low-voltage electric grids with no transmission losses, superefficient motors and generators, and myriad other schemes. But such everyday applications still lie in the future, because conventional superconductivity in metals can’t do the job.

Although they play important roles in science, industry, and medicine, conventional superconductors must be maintained at temperatures a few degrees above absolute zero, which is tricky and expensive. Wider uses will depend on higher-temperature superconductors that can function well above absolute zero. Yet known high-temperature (high-Tc) superconductors are complex materials whose electronic structures, despite decades of work, are still far from clear. (more…)