Tag Archives: als

Nanocrystals Not Small Enough to Avoid Defects

By Guest PostDecember 15, 2012Scienceals, berkeley lab, bin chen, computer simulation, crystal, defect, dislocation, gas turbine, grains, high pressure, jet engine, jialin lei, jinyuan yan, katie lutker, mechanical properties, metal, nanocrystal, nanocrystalline nickel, nanometer, nickel, non metal, plastic deformation, protective coating, resistance, selva vennila raju, stress, ultraviolet light, waruntorn kanitpanyacharoen

Berkeley Lab Scientists at Advanced Light Source Show Dislocations Can Be Induced by Pressure in Ultrafine Nanocrystals

Nanocrystals as protective coatings for advanced gas turbine and jet engines are receiving a lot of attention for their many advantageous mechanical properties, including their resistance to stress. However, contrary to computer simulations, the tiny size of nanocrystals apparently does not safeguard them from defects.

In a study by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab)and collaborators from multiple institutions, nanocrystals of nickel subjected to high pressure continued to suffer dislocation-mediated plastic deformation even when the crystals were only three nanometers in size. These experimental findings, which were carried out at Berkeley Lab’s Advanced Light Source (ALS), a premier source of X-rays and ultraviolet light for scientific research, show that dislocations can form in the finest of nanocrystals when stress is applied. (more…)

New Phenomenon in Nanodisk Magnetic Vortices

By Guest PostAugust 12, 2012Scienceals, antisymmetric coupling, atom, cxro, data storage, dzyaloshinskii moriya interaction, eye of hurricane, ferromagnetic nanodisk, hurricane, intrinsic factor, Japan, keisuke yamada, magnetic vortices, magnetism, mi young im, nanodisk, nanoscience, peter fischer, phenomenon, ram, shinya kasai, spin of electrons, symmetry, teruo ono, tomonori sato, xray beams, yoshinobu nakatani

Berkeley Lab Researchers Take a Mesocale Look at Magnetic Vortex Formations

The phenomenon in ferromagnetic nanodisks of magnetic vortices – hurricanes of magnetism only a few atoms across – has generated intense interest in the high-tech community because of the potential application of these vortices in non-volatile Random Access Memory (RAM) data storage systems. New findings from scientists at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) indicate that the road to magnetic vortex RAM might be more difficult to navigate than previously supposed, but there might be unexpected rewards as well.

In an experiment made possible by the unique X-ray beams at Berkeley Lab’s Advanced Light Source (ALS), a team of researchers led by Peter Fischer and Mi-Young Im of the Center for X-Ray Optics (CXRO), in collaboration with scientists in Japan, discovered that contrary to what was previously believed, the formation of magnetic vortices in ferromagnetic nanodisks is an asymmetric phenomenon. It is possible that this breaking of symmetry would lead to failure in a data storage device during its initialization process. (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…)

Molecular Spectroscopy Tracks Living Mammalian Cells in Real Time as They Differentiate

By Guest PostMay 2, 2012Scienceals, alzheimer's disease, amino acid residues, apoptosis, bacteria, berkeley lab, carbohydrates, cell change, cell death, children, diabetes, fibroblasts, fluorescent dyes, fourier transform infrared, ftir, function, hans bechtel, hoi ying, hyperspectromicroscopy, ir, kevin loutherback, liang chen, lipids, macular degeneration, michael martin, mitochondrial diseases, pc12, phosphorylation, phosphorylation process, power plant, protein, rafael gomez sjoberg, retina, san diego, serine, spectromicroscopy, threonine, tyrosine, ultraviolet, university of california, zhao hao

Berkeley Lab scientists demonstrate the promise of synchrotron infrared spectroscopy of living cells for medical applications

Knowing how a living cell works means knowing how the chemistry inside the cell changes as the functions of the cell change. Protein phosphorylation, for example, controls everything from cell proliferation to differentiation to metabolism to signaling, and even programmed cell death (apoptosis), in cells from bacteria to humans. It’s a chemical process that has long been intensively studied, not least in hopes of treating or eliminating a wide range of diseases. But until now the close-up view – watching phosphorylation work at the molecular level as individual cells change over time – has been impossible without damaging the cells or interfering with the very processes that are being examined.

“To look into phosphorylation, researchers have labeled specific phosphorylated proteins with antibodies that carry fluorescent dyes,” says Hoi-Ying Holman of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). “That gives you a great image, but you have to know exactly what to label before you can even begin.” (more…)

Locked RNA Editing Yields Odd Fly Behavior

By Guest PostApril 26, 2012Scienceabiotic factor, als, arthur sugden, asli sahin, brown university, cell, charles lawrence, dadar, enzyme adar, epilepsy, factor, fruit fly, function, genetic, jacquelyn dorsky, james jepson, lauren alpert, locking down, lou gehrigs disease, nucleus, organism, phenomenon, protein, rna, robert reenan, suicidal depression, temperature, wallflowers, yiannis savva

At the level of proteins, organisms can adapt by editing their RNA — and an editor can even edit itself. Brown University scientists working with fruit flies found that “locking down” the self-editing process at two extremes created some strange behaviors. They also found that the process is significantly affected by temperature.

PROVIDENCE, R.I. [Brown University] — Because a function of RNA is to be translated as the genetic instructions for the protein-making machinery of cells, RNA editing is the body’s way of fine-tuning the proteins it produces, allowing us to adapt. The enzyme ADAR, which does this editing job in the nervous system of creatures ranging from mice to men, even edits itself. In a new study that examined the self-editing process and locked it down at two extremes in fruit flies, Brown University scientists found some surprising insights into how this “fine-tuning of the fine-tuner” happens, including bizarre behavioral effects that come about when the self-editor can’t edit. (more…)

Diamonds and Dust for Better Cement

By Guest PostDecember 15, 2011Scienceadvanced light source, als, atomic scale structure, baking limestone, basic materials, beam of x rays, bulk modulus, c s h, calcium carbonate, calcium ions, calcium silicate hydrate, calipso, carbon dioxide, clay, clinker, CO2 emissions, diamonds, diffraction patterns, durability of concrete, human activity, hydrostatic pressure, mineral tobermorite, models, nanoscale, paulo monteiro, performance of cement, portland cement, practical alternatives, pressure, quaint village, scottish isle of mull, silicates, simon clark, southern california, stiffness, structure, surface of earth, university of california at berkeley, versatile concrete, water molecules

Structural studies at Berkeley Lab’s Advanced Light Source could point to reduced carbon emissions and stronger cements

It’s no surprise that humans the world over use more water, by volume, than any other material. But in second place, at over 17 billion tons consumed each year, comes concrete made with Portland cement. Portland cement provides the essential binder for strong, versatile concrete; its basic materials are found in many places around the globe; and, at about $100 a ton, it’s relatively cheap. Making it, however, releases massive amounts of carbon dioxide, accounting for more than five percent of the total CO₂ emissions from human activity.

“Portland cement is the most important building material in the world,” says Paulo Monteiro, a professor of civil and environmental engineering at the University of California at Berkeley, “but if we are going to find ways to use it more efficiently – or just as important, search for practical alternatives – we need a full understanding of its structure on the nanoscale.” To this end Monteiro has teamed with researchers at the U.S. Department of Energy’s Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. (more…)

The Brittleness of Aging Bones – More than a Loss of Bone Mass

By Guest PostSeptember 3, 2011Scienceadvanced light source, age related structural changes in human cortical bone, als, berkeley lab, biological aging, björn busse, bone strength and fracture toughness, bones, brittle, calcium, collagen molecules, concentric rings of lamellae plates, department of energy, doe, elizabeth zimmermann, eric schaible, fracturing, ha, holly barth, hrishikesh bale, human cortical or compact bone, hydroxyapatite, joel ager, lawrence berkeley national laboratory, loss of mass, macroscopic fracture testing, molecular level, nanocrystals, nanoscale, older bones fracturing, peter reichert, robert ritchie, simon tang, tamara alliston, uc, university of california, young human bone

*Berkeley Lab Researchers Show How Loss of Bone Quality Also a Major Factor*

It is a well-established fact that as we grow older our bones become more brittle and prone to fracturing. It is also well established that loss of mass is a major reason for older bones fracturing more readily than younger bones, hence medical treatments have focused on slowing down this loss. However, new research from scientists at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) shows that at microscopic dimensions, the age-related loss of bone quality can be every bit as important as the loss of quantity in the susceptibility of bone to fracturing. (more…)