University of Pennsylvania researchers are now among the first to produce a single, three-atom-thick layer of a unique two-dimensional material called tungsten ditelluride. Their findings have been published in 2-D Materials.
Unlike other two-dimensional materials, scientists believe tungsten ditelluride has what are called topological electronic states. This means that it can have many different properties not just one.
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The energy supply to Longyearbyen, midway between continental Norway and the North Pole, is a hot topic in the climate debate.
Longyearbyen is the largest settlement and the administrative centre of Svalbard, a Norwegian archipelago in the Arctic Ocean. Today, Longyearbyen obtains its electric power and district heating from its coal power plant, the only one in Norway.
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America’s appetite for Greek yogurt has skyrocketed over the past decade. But for every container of Greek yogurt consumed, you could fill two or three more with the acid whey it produces. The cover story in Chemical & Engineering News (C&EN), the weekly newsmagazine of the American Chemical Society, takes a look at the interesting ways scientists are making use of the byproduct.
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Thwaites Glacier on the edge of West Antarctica is one of the planet’s fastest-moving glaciers. Research shows that it is sliding unstoppably into the ocean, mainly due to warmer seawater lapping at its underside.
But the details of its collapse remain uncertain. The details are necessary to provide a timeline for when to expect 2 feet of global sea level rise, and when this glacier’s loss will help destabilize the much larger West Antarctic Ice Sheet. Recent efforts have used satellites to map the underlying terrain, which affects how quickly the ice mass will move, and measure the glacier’s thickness and speed to understand the physics of its changes.
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All known black holes fall into two categories: small, stellar-mass black holes weighing a few Suns, and supermassive black holes weighing millions or billions of Suns. Astronomers expect that intermediate-mass black holes weighing 100 - 10,000 Suns also exist, but so far no conclusive proof of such middleweights has been found. Today, astronomers are announcing new evidence that an intermediate-mass black hole (IMBH) weighing 2,200 Suns is hiding at the center of the globular star cluster 47 Tucanae.
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A team of scientists from the Energy Department's National Renewable Energy Laboratory (NREL) determined that surface recombination limits the performance of polycrystalline perovskite solar cells.
Considerable research into perovskites at NREL and elsewhere has proved the material's effectiveness at converting sunlight into electricity, routinely topping 20 percent efficiency. The sunlight creates mobile electrons whose movement generates the power but upon encountering defects can slip into a non-productive process. Known as a recombination, this process reduces the efficiency of a solar cell. For the cell to be the most efficient, the recombination must occur slowly.
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A study led by UC Santa Cruz researchers has found that drought dramatically increases the severity of West Nile virus epidemics in the United States, although populations affected by large outbreaks acquire immunity that limits the size of subsequent epidemics.
The study, published February 8 in Proceedings of the Royal Society B, involved researchers from UC Santa Cruz, Stanford University, and the New York State Department of Health. They analyzed 15 years of data on human West Nile virus infections from across the United States and found that epidemics were much larger in drought years and in regions that had not suffered large epidemics in the past.
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