Catching graphene butterflies

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Writing in Nature, a large international team led Dr Roman Gorbachev from The University of Manchester shows that, when graphene placed on top of insulating boron nitride, or 'white graphene', the electronic properties of graphene change dramatically revealing a pattern resembling a butterfly.

The pattern is referred to as the elusive Hofstadter butterfly that has been known in theory for many decades but never before observed in experiments.

First direct proof of Hofstadter butterfly fractal observed in moiré superlattices

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Observation of second sound in a quantum gas

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Below a critical temperature, certain fluids become superfluid and lose internal friction. In addition, fluids in this state conduct heat extremely efficiently, with energy transport occurring in a distinct temperature wave. Because of the similarities to a sound wave, this temperature wave is also called second sound. To explain the nature of superfluids, the famous physicist Lev Landau developed the theory of two-fluid hydrodynamics in Moscow in 1941.

Terracotta and cement roofs vulnerable in wildfires, NIST study finds

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Although made of fire-resistant materials, terracotta and cement roof tiles are vulnerable to penetration by windblown embers generated in wildfires, according to new research findings* from the National Institute of Standards and Technology (NIST).

In scoping experiments conducted in the Fire Research Wind Tunnel Facility at Japan's Building Research Institute, NIST fire scientist Samuel Manzello found that the embers—or firebrands—infiltrated gaps between certain types of roofing tiles and, once trapped, proceeded to melt the underlayment below.

European Research Infrastructures help to solve air quality issues

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Brussels. Scientists have advocated for tightening the Air Quality Directive and expand research on air quality and climate change. Only appropriate investments in research can provide a solid basis for decision making in these areas that have major health and economic consequences for Europe's citizens. In 2013, the European Commission's air policy is reviewed, with a focus on finding ways to improve the quality of the air Europeans breathe.

European winter weather harder to forecast in certain years

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Weather forecasters have a tougher job predicting winter conditions over Europe in some years over others, concludes a new study carried out by the National Oceanography Centre.

The study revealed that the relationship between our winter weather and the strength of the airflow coming in from the Atlantic – one of the factors used by forecasters to predict the weather – is stronger in some years than others. The results were recently published in the Royal Meteorological Society publication Weather.

UCLA study shows warming in central China greater than most climate models indicated

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Temperatures in central China are 10 to 14 degrees Fahrenheit hotter today than they were 20,000 years ago, during the last ice age, UCLA researchers report — an increase two to four times greater than many scientists previously thought.

The findings, published today in the early online edition of the journal Proceedings of the National Academy of Sciences, could help researchers develop more accurate models of past climate change and better predict such changes in the future.

RUB physicists let magnetic dipoles interact on the nanoscale for the first time

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Fall warming on Antarctic Peninsula driven by tropically forced circulation

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The eastern side of the Antarctic Peninsula, a finger of the southern polar continent that juts toward South America, has experienced summer warming of perhaps a half-degree per decade – a greater rate than possibly anywhere else on Earth – in the last 50 years, and that warming is largely attributed to human causes.

Groundwater unaffected by shale gas production in Arkansas

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DURHAM, N.C. -- A new study by scientists at Duke University and the U.S. Geological Survey (USGS) finds no evidence of groundwater contamination from shale gas production in Arkansas.

"Our results show no discernible impairment of groundwater quality in areas associated with natural gas drilling and hydraulic fracturing in this region," said Avner Vengosh, professor of geochemistry and water quality at Duke's Nicholas School of the Environment.