Earth | Page 621 | Science Codex

UCSB researchers identify specific defects in LED diodes that lead to less efficient solid state lighting

Using state-of-the-art theoretical methods, UCSB researchers have identified a specific type of defect in the atomic structure of a light-emitting diode (LED) that results in less efficient performance. The characterization of these point defects could result in the fabrication of even more efficient, longer lasting LED lighting.

"Techniques are available to assess whether such defects are present in the LED materials and they can be used to improve the quality of the material," said materials professor Chris Van de Walle, whose research group carried out the work.

Advance may make quantum computing more practical

Quantum computers are largely hypothetical devices that could perform some calculations much more rapidly than conventional computers can. They exploit a property called superposition, which describes a quantum particle's counterintuitive ability to, in some sense, inhabit more than one physical state at the same time.

Geothermal heat contributes to Greenland ice melt

MISSOULA, MONTANA - An international team that includes University of Montana researcher Jesse Johnson has learned that the Earth's internal heat enhances rapid ice flow and subglacial melting in Greenland.

Johnson, a UM computer science professor and ice-sheet modeler, helped discover that about half of the ice-covered area in north-central Greenland rests on a thawed bed and that the meltwater is routed to the ocean through a dense hydrological network beneath the ice.

Large variations in precipitation over the past millennium

According to a new study in Nature, the Northern Hemisphere has experienced considerably larger variations in precipitation during the past twelve centuries than in the twentieth century. Researchers from Sweden, Germany, and Switzerland have found that climate models overestimated the increase in wet and dry extremes as temperatures increased during the twentieth century. The new results will enable us to improve the accuracy of climate models and to better predict future precipitation changes.

Becoming crystal clear

Using state-of-the-art theoretical methods, UCSB researchers have identified a specific type of defect in the atomic structure of a light-emitting diode (LED) that results in less efficient performance. The characterization of these point defects could result in the fabrication of even more efficient, longer lasting LED lighting.

"Techniques are available to assess whether such defects are present in the LED materials and they can be used to improve the quality of the material," said materials professor Chris Van de Walle, whose research group carried out the work.

PPPL scientists help test innovative device to improve efficiency of tokamaks

Scientists at the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL) have helped design and test a component that could improve the performance of doughnut-shaped fusion facilities known as tokamaks. Called a "liquid lithium limiter," the device has circulated the protective liquid metal within the walls of China's Experimental Advanced Superconducting Tokamak (EAST) and kept the plasma from cooling down and halting fusion reactions. The journal Nuclear Fusion published results of the experiment in March 2016. The research was supported by the DOE Office of Science.

Optical approach offers faster and less expensive method for carbon dating

WASHINGTON -- Researchers from Istituto Nazionale di Ottica (INO), within Consiglio Nazionale delle Ricerche (CNR), Italy have demonstrated a new compact spectroscopic instrument that offers a highly sensitive optical method for detecting radiocarbon dioxide concentration, which can be used to carbon date fossils and archaeological artifacts.

New spectroscopy of 10 Be hypernucleus redefines the reference data of Lambda hypernuclei

A team of international researchers has successfully measured precise binding energy of a (_Λ^10)Be hypernucleus made of four protons (p), five neutrons (n) and a Lambda (Λ) particle, at Thomas Jefferson National Accelerator Facility (JLab), USA.

The research team, known as HKS Collaboration, consists of 76 members from 21 institutes led by Tohoku University, Hampton University and Florida International University.

Therapsids adapted to drastic climate change by having shorter life expectancies

Two hundred and fifty-two million years ago, a series of Siberian volcanoes erupted and sent the Earth into the greatest mass extinction of all time. Billions of tons of carbon were propelled into the atmosphere, radically altering the Earth's climate.

Yet, some animals thrived in the aftermath and scientists now know why.

Record-breaking steel could be used for body armor, shields for satellites

A team of engineers has developed and tested a type of steel with a record-breaking ability to withstand an impact without deforming permanently. The new steel alloy could be used in a wide range of applications, from drill bits, to body armor for soldiers, to meteor-resistant casings for satellites.

The material is an amorphous steel alloy, a promising subclass of steel alloys made of arrangements of atoms that deviate from steel's classical crystal-like structure, where iron atoms occupy specific locations.

Can urban gardeners benefit ecosystems while keeping food traditions alive?

URBANA, Ill. - When conjuring up an image of a healthy ecosystem, few of us would think of a modern city. But scientists are increasingly recognizing that the majority of ecosystems are now influenced by humans, and even home gardens in urban landscapes can contribute important ecosystem services.

Summer melt-driven streams on Greenland's ice sheet brought into focus

EUGENE, Ore. -- April 5, 2016 -- Erosion by summertime melt-driven streams on Greenland's ice sheet shapes landscapes similarly to, but much faster than, rivers do on land, says a University of Oregon geologist.

The approach used to study the ice sheet should help to broaden scientific understanding of melt rates and improve projections about glacial response to climate change, says Leif Karlstrom, a professor in the UO Department of Geological Sciences.

Breaking metamaterial symmetry with reflected light

Washington, D.C., April 5, 2016 -- Optical activity--rotation of the polarization of light--is well known to occur within materials that differ from their mirror image. But what happens if this symmetry is broken by the direction of illumination rather than the material itself?

A movie of the microworld: Physicists create nanoparticle picture series

MANHATTAN, KANSAS -- Think of it as a microscopic movie: A sequence of X-ray images shows the explosion of superheated nanoparticles. The picture series reveals how the atoms in these particles move, how they form plasma and how the particles change shape.

The method of taking these pictures is a collaborative creation that involved Kansas State University researchers Artem Rudenko and Daniel Rolles, both assistant professors of physics.

NUS-led research team discovers novel way of transferring magnetic information

A team led by researchers from the National University of Singapore (NUS) has achieved a major breakthrough in magnetic interaction. By adding a special insulator, they make electrons "twirl" their neighbouring "dance partners" to transfer magnetic information over a longer range between two thin layers of magnetic materials. This novel technique enables magnetic information to make their way from one magnetic layer to another, synonymous to the encoding and transmission of data.