Liquefied metals can be turned into glass
Materials scientists have long sought to form glass from pure, monoatomic metals. A team at the University of Pittsburgh has done it.
Their paper, “Formation of Monoatomic Metallic Glasses Through Ultrafast Liquid Quenching,” was recently published online in Nature.
Metallic glasses are unique in that their structure is not crystalline (as it is in most metals), but disordered – with the atoms randomly arranged. They are sought for various commercial applications because they are very strong and are easily processed.
Scott Mao, a professor of mechanical engineering and materials science at Pittsburgh, developed a new technique – a cooling nano-device under in-situ transmission electron microscope – that enabled him and his colleagues to achieve an unprecedentedly high cooling rate that allowed for the transformation of liquefied elemental metals tantalum and vanadium into glass. pitt.edu
Ancient shells rewrite history of El Niños
El Niño – the planet’s largest and most powerful driver of climate changes from one year to the next – was widely thought to have been weaker in ancient times because of a different configuration of Earth’s orbit. But scientists analyzing 25-foot piles of ancient shells have found that El Ninos 10,000 years ago were as strong and frequent as the ones today.
The results, from the University of Washington and France’s University of Montpellier, question how well computer models can reproduce historical El Nino cycles, or predict how they could change under future climates. The paper is posted at Sciencemag.org and will appear in an upcoming issue of Science.
“Our data contradicts the hypothesis that El Niño activity was very reduced 10,000 years ago, and then slowly increased since then,” said first author Matthieu Carré. In 2007, he accompanied archaeologists to seven sites in coastal Peru to sample 25-foot-tall piles of shells from clams eaten and then discarded over centuries into piles.
The shells provide one- to three-year records of monthly temperature of the Pacific Ocean along the coast of Peru. Combining layers of shells from each site gives water temperatures for intervals spanning 100 to 1,000 years during the past 10,000 years. The new record shows that 10,000 years ago the El Niño cycles were strong. washington.edu/news
Bumble bees recruited to make N.C. beer
What does oyster beer taste like? Find out in Raleigh from 6 to 9 p.m. Thursday when the N.C. Museum of Natural Sciences hosts “Natural Selections: The Wake County Science and Brewers Expo” with more than a dozen N.C. breweries.
You can also be among the first to taste an experimental beer made with yeast isolated from bumble bees; the beer was recently developed by the N.C. State Brewery in collaboration with scientists affiliated with the lab of Rob Dunn in N.C. State’s Department of Biological Sciences. Tickets ($25) and details: www.naturalsciences.org/beer. Staff Reports