PROVIDENCE, R.I. [Brown University] — Materials scientists have known that a metal's strength (or weakness) is governed by dislocation interactions, a messy exchange of intersecting fault lines that move or ripple within metallic crystals. But what happens when metals are engineered at the nanoscale? Is there a way to make metals stronger and more ductile by manipulating their nanostructures?
Earth
OAK RIDGE, Tenn., April 7, 2010 -- An international team of scientists from Russia and the United States, including two Department of Energy national laboratories and two universities, has discovered the newest superheavy element, element 117.
The team included scientists from the Joint Institute of Nuclear Research (Dubna, Russia), the Research Institute for Advanced Reactors (Dimitrovgrad), Lawrence Livermore National Laboratory, Oak Ridge National Laboratory, Vanderbilt University, and the University of Nevada, Las Vegas.
An international team of scientists from Russia and the United States, including two Department of Energy national laboratories and two universities, has discovered the newest superheavy element, element 117.
The team included scientists from the Joint Institute of Nuclear Research (Dubna, Russia), the Research Institute for Advanced Reactors (Dimitrovgrad), Lawrence Livermore National Laboratory, Oak Ridge National Laboratory, Vanderbilt University, and the University of Nevada, Las Vegas.
(Santa Barbara, Calif.) –– The major earthquake that occurred in Baja California on Easter Sunday, April 4th, at 3:40 p.m. Pacific Time, is of great interest to UC Santa Barbara seismologists, who are busy collecting information from a nearby research station. The earthquake was the largest in the Southern California region since 1992.
A collaboration of Russian and US physicists has finally created element 117 - a superheavy element made of atoms containing 117 protons that is roughly 40% heavier than lead. The achievement fills in the final gap on the list of observed elements up to element 118. The team produced the elusive element 117 by fusing together atoms of calcium and another rare, heavy element known as berkelium.
Self-pollinating almond trees that can produce a bountiful harvest without insect pollination are being developed by Agricultural Research Service (ARS) scientists. This is good news for almond growers who face rising costs for insect pollination because of nationwide shortages of honeybees due to Colony Collapse Disorder (CCD) and other factors.
ARS geneticist Craig Ledbetter, at the agency's Crop Diseases, Pests and Genetics Research Unit near Parlier, Calif., is developing this new line of self-pollinating almond trees.
Four billion years ago, our then stripling sun radiated only 70 to 75 percent as much energy as it does today. Other things on Earth being equal, with so little energy reaching the planet's surface, all water on the planet should been have frozen. But ancient rocks hold ample evidence that the early Earth was awash in liquid water – a planetary ocean of it. So something must have compensated for the reduced solar output and kept Earth's water wet.
The discovery of a new fossil turtle species in Colombia's Cerrejón coal mine by researchers from the Smithsonian Tropical Research Institute in Panama and the Florida Museum of Natural History helps to explain the origin of one of the most biodiverse groups of turtles in South America.
Cerrejonemys wayuunaiki takes its genus name from Cerrejón, and emys—Greek for turtle. Its species name is the language spoken by the Wayuu people who live on the Guajira Peninsula in northeastern Colombia near the mine.
(Santa Barbara, Calif.) –– In an analysis of the past 1.2 million years, UC Santa Barbara geologist Lorraine Lisiecki discovered a pattern that connects the regular changes of the Earth's orbital cycle to changes in the Earth's climate. The finding is reported in this week's issue of the scientific journal Nature Geoscience.
CAMBRIDGE, Mass., April 6, 2010 -- Carbon nanotubes, long touted for applications in materials and electronics, may also be the stuff of atomic-scale black holes.
Physicists at Harvard University have found that a high-voltage nanotube can cause cold atoms to spiral inward under dramatic acceleration before disintegrating violently. Their experiments, the first to demonstrate something akin to a black hole at atomic scale, are described in the current issue of the journal Physical Review Letters.
A description of a 95-million-year-old amber deposit—the first major discovery of its kind from the African continent—is adding new fungus, insects, spiders, nematodes, and even bacteria to an ecosystem that had been shared by dinosaurs. In addition, the amber deposit may provide fresh insights into the rise and diversification of flowering plants during the Cretaceous.
ANN ARBOR, Mich.---Trailing like a serpent's spine along the western coast of South America, the Andes are the world's longest continental mountain range and the highest range outside Asia, with an average elevation of 13,000 feet.
The question of how quickly the mountains attained such heights has been a contentious one in geological circles, with some researchers claiming the central Andes rose abruptly to nearly their current height and others maintaining the uplift was a more gradual process.
The team tested the nanotribological, or nano-scale frictional properties, of graphene, molybdenum disulfide (MoS2), hexagonal-BN (h-BN) and niobium diselenide (NbSe2) down to single atomic sheets. The team literally shaved off atomic-scale amounts of each material onto a silicon oxide substrate and compared their findings to the bulk counterparts. Each material exhibited the same basic frictional behavior despite having electronic properties that vary from metallic to semiconducting to insulating.
How hard do you have to pull on a single atom of—let's say—gold to detach it from the end of a chain of like atoms?* It's a measure of the astonishing progress in nanotechnology that questions that once would have interested only physicists or chemists are now being asked by engineers. To help with the answers, a research team at the National Institute of Standards and Technology (NIST) has built an ultra-stable instrument for tugging on chains of atoms, an instrument that can maneuver and hold the position of an atomic probe to within 5 picometers, or 0.000 000 000 5 centimeters.**
Scientists in Islamic countries are often thought by those in the West to be languishing behind the rest of the world. Jim Al-Khalili tells Physics World readers what has been impeding scientific progress in the Islamic world – where historically science was once so strong -- and examines some projects that could herald a brighter future.