Tag Archives: protons

Hydrogen Fuel from Sunlight

By Guest PostSeptember 13, 2013Sciencealexandra krawicz, artificial photosynthesis, berkeley lab, caltech, carbohydrate sugars, carbon dioxide, carbon dioxide reduction, earth abundant elements, eitan anzenberg, free electrons, gallium phosphide, gary moore, generate electricity, green sustainable energy, hydrogen fuel, hydrogen ions, hydrogen producing catalysts, ian sharp, jinhui yang, junko yano, non photoactive substrates, photoelectrochemical operations, protons, sunlight

Berkeley Lab Researchers at Joint Center for Artificial Photosynthesis Make Unique Semiconductor/Catalyst Construct

In the search for clean, green sustainable energy sources to meet human needs for generations to come, perhaps no technology matches the ultimate potential of artificial photosynthesis. Bionic leaves that could produce energy-dense fuels from nothing more than sunlight, water and atmosphere-warming carbon dioxide, with no byproducts other than oxygen, represent an ideal alternative to fossil fuels but also pose numerous scientific challenges. A major step toward meeting at least one of these challenges has been achieved by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) working at the Joint Center for Artificial Photosynthesis (JCAP).

“We’ve developed a method by which molecular hydrogen-producing catalysts can be interfaced with a semiconductor that absorbs visible light,” says Gary Moore, a chemist with Berkeley Lab’s Physical Biosciences Division and principal investigator for JCAP. “Our experimental results indicate that the catalyst and the light-absorber are interfaced structurally as well as functionally.” (more…)

A Cyclotron’s Long Journey Home

By Guest PostMarch 2, 2013Scienceamerican science, atom smashers, atomic energy commission, aundra richards, berkeley hills, berkeley lab, brass cyclotron, circular particle accelerator, cyclotrons, david shirley, diameter, electron volts, ernest o lawrence, hall of science, hydrogen atoms, invention, kinetic energy, lab history, Large Hadron Collider, light, london science museum, merry go round, modern particle physics, natalie roe, nobel prize, nuclei, pamela patterson, paul alivisatos, protons, secret, Smithsonian, speed, the royal society, uk museum, university of california, Washington, yale university

One of the world’s first working circular particle accelerators returns to Berkeley Lab—75 years later.

Seventy-five years after one of the world’s first working cyclotrons was handed to the London Science Museum, it has returned to its birthplace in the Berkeley hills, where the man who invented it, Ernest O. Lawrence, helped launch the field of modern particle physics as well as the national laboratory that would bear his name, Lawrence Berkeley National Laboratory.

On Jan. 9, 1932 the brass cyclotron—which measures 26 inches from end to end and whose accelerating chamber measures just 11 inches in diameter—was successfully used to boost protons to energies of 1.22 million electron volts. Its return to Berkeley Lab caps a decades-long saga in which various parties endeavored to secure the cyclotron’s return from London, but the persistence of Pamela Patterson, who chronicles Berkeley Lab’s history as managing editor of its website, finally paid off. (more…)

Researchers Propose New Way to Probe Earth’s Deep Interior

By Guest PostFebruary 25, 2013Scienceafu lin, amherst college, atoms, austin, building blocks, central core, characteristics, characteristics of mantle, chemical properties, composition, deep earth, earth, earth rotation axis, electromagnetism, electron spin density, electrons, elusive fifth force, fifth force, geoelectrons, geological layer, geomagnetic field, gravitational attraction, gravity, interior, jung fu, larry hunter, magnetic interaction, mantle, Nature, neutrons, new technique, outer crust, protons, researchers, spin, spin directions, spin spin interaction, strong nuclear forces, subatomic particles, university of texas

AUSTIN, Texas — Researchers from Amherst College and The University of Texas at Austin have described a new technique that might one day reveal in higher detail than ever before the composition and characteristics of the deep Earth.

There’s just one catch: The technique relies on a fifth force of nature (in addition to gravity, the weak and strong nuclear forces and electromagnetism) that has not yet been detected, but which some particle physicists think might exist. Physicists call this type of force a long-range spin-spin interaction. If it does exist, this exotic new force would connect matter at Earth’s surface with matter hundreds or even thousands of kilometers below, deep in Earth’s mantle. In other words, the building blocks of atoms—electrons, protons, and neutrons—separated over vast distances would “feel” each other’s presence. The way these particles interact could provide new information about the composition and characteristics of the mantle, which is poorly understood because of its inaccessibility. (more…)

Do We Live in a Computer Simulation? UW Researchers Say Idea Can be Tested

By Guest PostDecember 12, 2012Scienceatom, belief, binds subatomic particles, british philosopher, computer model, computer simulation, concept, cosmic rays, evolutionary history, four dimensional grid, fundamental forces, gluons, human species, lattice quantum chromodynamics, martin savage, model, molecule, Nature, neutrons, nick bostrom, notion, nucleus, parallel universe, physical laws, posthuman civilization, posthuman stage, potential test, primitive simulations, protons, quarks, scale, silas beane, small scale simulations, space time continuum, supercomputers, technique, universe, university of oxford, university of washington, zohreh davoudi

A decade ago, a British philosopher put forth the notion that the universe we live in might in fact be a computer simulation run by our descendants. While that seems far-fetched, perhaps even incomprehensible, a team of physicists at the University of Washington has come up with a potential test to see if the idea holds water.

The concept that current humanity could possibly be living in a computer simulation comes from a 2003 paper published in Philosophical Quarterly by Nick Bostrom, a philosophy professor at the University of Oxford. In the paper, he argued that at least one of three possibilities is true:

The human species is likely to go extinct before reaching a “posthuman” stage.
Any posthuman civilization is very unlikely to run a significant number of simulations of its evolutionary history.
We are almost certainly living in a computer simulation. (more…)

Researchers Reveal Structure of Carbon’s ‘Hoyle State’

By Guest PostDecember 11, 2012Sciencealpha clusters, alpha particles, bent arm, carbon 12, dean lee, element, evgeny epelbaum, german colleague, helium 4 nuclei, hermann krebs, hoyle state, lattice, life on earth, neutrons, north Carolina, nucleons, particle, physicist, picture, protons, simulate, snapshot, state university, structure, timo laehde, ulf g meissner

A North Carolina State University researcher has taken a “snapshot” of the way particles combine to form carbon-12, the element that makes all life on Earth possible. And the picture looks like a bent arm.

Carbon-12 can only exist when three alpha particles, or helium-4 nuclei, combine in a very specific way. This combination is known as the Hoyle state. NC State physicist Dean Lee and German colleagues Evgeny Epelbaum, Hermann Krebs and Ulf-G. Meissner had previously confirmed the existence of the Hoyle state using a numerical lattice that allowed the researchers to simulate how the protons and neutrons interact. When the researchers ran their simulations on the lattice, the Hoyle state appeared together with other observed states of carbon-12, proving the theory correct from first principles. (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…)

Homing in on Higgs: Michigan Researchers Predict Summer Discovery

By Guest PostJune 4, 2012Scienceaaron armbruster, algorithms, atlas, atoms, bing zhou, CERN, Chicago, electromagnetic radiation, electrons, fermilab, forces, function, geneva, gordon kane, higgs, higgs boson, higgs field particles, homer neal, jianming qian, junjie zhu, Large Hadron Collider, laws, laws of nature, lhc, missing piece, Nature, neutrons, newton, particle physics, physics theory, protons, quarks, rudolf thun, standard model, stephen hawking, summer, switzerland, tevatron particle accelerator, university of michigan, vacuum like state

ANN ARBOR, Mich.— Whether the Higgs boson exists could be settled by the end of summer, say University of Michigan physicists involved in the search for the missing piece of particle physics’ Standard Model.

“We’re zooming in,” said Jianming Qian, physics professor in the College of Literature, Science & the Arts. “We are increasing the data set and improving our search algorithms. With certain luck, we may be able to discover it this summer, but it depends on nature.”

Qian is one of the 28 U-M researchers involved in experiments at CERN’s Large Hadron Collider (LHC) in Switzerland. He’ll spend most of his time through August in Geneva, where more than 1,000 scientists from around the world have been looking for Higgs since the collider turned on about four years ago. (more…)

‘Fingerprinting’ Method Tracks Mercury Emissions from Coal-Fired Power Plant

By Guest PostDecember 17, 2011Environmentatmosphere, brains of fetuses, central nervous system, chemical fingerprints, chlorine producing plants, coal, coal combustion, coal fired power plants, coal samples, crystal river, crystal river plant, eastern kentucky, effects on humans, element mercury, environmental pollution, gerald keeler, global atmospheric pool, global mercury reservoir, heart, immune system, incinerators, isotopic fractionation, jason demers, joel blum, laura sherman, mass dependent fractionation, mdf, mercury emissions, mercury emissions in florida, mercury fingerprinting technique, mercury isotope fingerprints, methylmercury, microorganism, natural phenomenon, naturally occurring element, non radioactive, nuclei, power plant, primary source of mercury pollution, protons, rainfall, timothy dvonch, toxic, university of michigan, west virginia

ANN ARBOR, Mich.— For the first time, the chemical “fingerprints” of the element mercury have been used by University of Michigan researchers to directly link environmental pollution to a specific coal-burning power plant.

The primary source of mercury pollution in the atmosphere is coal combustion. The U-M mercury-fingerprinting technique – which has been under development for a decade – provides a tool that will enable researchers to identify specific sources of mercury pollution and determine how much of it is being deposited locally. (more…)