Glaciers reached Cape Cod, Massachusetts, in the most recent ice age about 20,000 years ago. But much harsher ice ages hit the Earth in an ancient geological interval known as "the Cryogenian Period" between 750 and 600 million years ago. A team of geologists from China and the United States now report evidence of at least three ice ages during that ancient time.
Shown is a glacial cobble from the Nantuo Formation, Guizhou Province, South China. Grooved scratch marks on this cobble were formed when it was frozen in a moving glacier and ground against the underlying pavement of the glacial valley.
"The Cryogenian Period is characterized by some of the worst glaciations in earth history. But the available age constraints are so few that geoscientists dont even know how many glaciations occurred in the Cryogenian. Now, we believe we have evidence that there were at least three Cryogenian glaciations, and there may have been more," says Shuhai Xiao of Virginia Techs Department of Geosciences.
Chuanming Zhou, a Virginia Tech geosciences post-doctoral associate, along with Xiao, Robert Tucker and Zhanxiong Peng of the Department of Earth and Planetary Sciences at Washington University of St. Louis, and Xunlai Yuan and Zhe Chen of Nanjing Institute of Geology and Paleontology, are co-authors of "New constraints on the ages of Neoproterozoic glaciations in South China," the cover story in the May 2004 issue Geology, the journal of the Geological Society of America.
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Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
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At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
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Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
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UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
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Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
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