Thursday 7 August 2014

Carbyne morphs when stretched

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Applying just the right amount of tension to a chain of carbon atoms can turn it from a metallic conductor to an insulator, according to Rice University scientists. Stretching the material known as carbyne — a hard-to-make, one-dimensional chain of carbon atoms — by just 3 percent can begin to change its properties in ways that engineers might find useful for mechanically activated nanoscale electronics and optics.   Carbyne turns from a metal to a semiconductor when stretched, according to calculations by Rice University scientists. Pulling on the ends would force the atoms to separate in pairs, opening a band gap. The chain of single carbon atoms would theoretically be the strongest material ever if it could be made reliably. (Credit: Vasilii Artyukhov/Rice University)     The finding by Rice theoretical physicist Boris Yakobson and his colleagues appears in the American Chemical Society journal Nano Letters. Until recently, carbyne has existed mostly in theory, though experimentalists have made some headway in creating small samples of the finicky material. The carbon chain would theoretically be the strongest material ever, if only someone could make it reliably. The first-principle calculations by Yakobson and his co-authors, Rice postdoctoral researcher Vasilii Artyukhov and graduate student Mingjie Liu, show

The post Carbyne morphs when stretched has been published on Technology Org.

 
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Astronomers find stream of gas, 2.6 million light years long

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Astronomers and students have found a bridge of atomic hydrogen gas 2.6 million light years long between galaxies 500 million light years away. The stream of atomic hydrogen gas is the largest known, a million light years longer than a gas tail found in the Virgo Cluster by another Arecibo project a few years ago.

via Science Daily

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Synthesis of structurally pure carbon nanotubes using molecular seeds

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For the first time, researchers have succeeded in "growing" single-wall carbon nanotubes (CNT) with a single predefined structure -- and hence with identical electronic properties. And here is how they pulled it off: the CNTs "assembled themselves", as it were, out of tailor-made organic precursor molecules on a platinum surface. In future, CNTs of this kind may be used in ultra-sensitive light detectors and ultra-small transistors.

via Science Daily

"You Are Here" Milky Way Galaxy Poster

Here's a great poster featuring a beautiful image from deep space


tagged with: milky way, galaxy, astronomy, science, classroom poster, nasa, outer space, space, fun science

Poster shows gorgeous rendering of Milky Way Galaxy using latest telescope data (public domain image by NASA/Caltech), plus a "You Are Here" arrow pointing to the Earth's local neighborhood.

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Rosetta arrives

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Video highlights from the event at ESA's mission control centre during Rosetta's arrival at comet 67P/C-G on 6 August 2014

via ESA Space Science

http://www.esa.int/ESA_Multimedia/Videos/2014/08/Rosetta_arrival_highlights

Tracking and combatting our current mass extinction

Science Focus

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Ecosystem engineer: a giant tortoise native to a different island creates wallows that trap rain water on a dry island in Mauritius.
Zairabee Ahamud

At various times in its past, the Earth has succeeded in killing off most of its inhabitants. Although the impact that killed the non-avian dinosaurs and many other species gets most of the attention, the majority of the mass extinctions we're aware of were driven by geological processes and the changes in climate that they triggered.

Unfortunately, based on the current rate at which animals are vanishing for good, we're currently in the midst of another mass extinction, this one driven by a single species: humans. (And many of the extinctions occurred before we started getting serious about messing with the climate.) This week's edition of Science contains a series of articles tracking the pace of the extinction and examining our initial efforts to contain it.

Extinction and “defaunation”

Estimating the total number of animal species is a challenging task, but numbers range from roughly five to 10 million. Of those, we seem to be exterminating about 10,000 to 60,000 every year. Up to a third of the remaining vertebrate species are thought to be threatened or endangered. Amphibians have it even worse, with over 40 percent of species considered threatened.

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 » see original post http://feeds.arstechnica.com/~r/arstechnica/science/~3/iZmmpHOYN2k/
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Uncertainty gives scientists new confidence in search for novel materials

Science Focus

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Scientists at Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory have found a way to estimate uncertainties in computer calculations that are widely used to speed the search for new materials for industry, electronics, energy, drug design and a host of other applications. The technique, reported in the July 11 issue of Science, should quickly be adopted in studies that produce some 30,000 scientific papers per year. This image shows the results of calculations aimed at determining which of six chemical elements would make the best catalyst for promoting an ammonia synthesis reaction. Researchers at SLAC and Stanford used Density Functional Theory (DFT) to calculate the strength of the bond between nitrogen atoms and the surfaces of the catalysts. The bond strength, plotted on the horizontal axis, is a key factor in determining the reaction speed, plotted on the vertical axis. Based on thousands of these calculations, which yielded a range of results (colored dots) that reveal the uncertainty involved, researchers estimated an 80 percent chance that ruthenium (Ru, in red) will be a better catalyst than iron (Fe, in orange.) (Andrew Medford and Aleksandra Vojvodic/SUNCAT, Callie Cullum) “Over the past 10 years our ability to calculate the properties of

The post Uncertainty gives scientists new confidence in search for novel materials has been published on Technology Org.

 
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 » see original post http://feedproxy.google.com/~r/TechnologyOrgPhysicsNews/~3/o1i9wzLeX4g/
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UK's deep sea mountain life filmed

Science Focus

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Scientists send a remotely operated vehicle to film one of the UK's deep sea mountains for the first time. 
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 » see original post http://www.bbc.co.uk/news/28583945#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa
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Rosetta's Rendezvous

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On August 3rd, the Rosetta spacecraft's narrow angle camera captured this stunning image of the nucleus of Comet 67P/Churyumov-Gerasimenko. After 10 years and 6.5 billion kilometers of travel along gravity assist trajectories looping through interplanetary space, Rosetta had approached to within 285 kilometers of its target. The curious double-lobed shape of the nucleus is revealed in amazing detail at an image resolution of 5.3 meters per pixel. About 4 kilometers across, the comet nucleus is presently just over 400 million kilometers from Earth, between the orbits of Jupiter and Mars. Now the first spacecraft to achieve a delicate orbit around a comet, Rosetta will swing to within 50 kilometers and closer in the coming weeks, identifiying candidate sites for landing its probe Philae later this year.

Zazzle Space Gifts for young and old

Hubble Snow Angel iPad Mini Covers

Here's a great iPad case from Zazzle featuring a Hubble-related design. Maybe you'd like to see your name on it? Click to personalize and see what it's like!


tagged with: celestial, cosmic, snow, angel, nebula, nasa, hubble, space, image, stars

A December 2011 release from NASA/Hubble features a nebula that looks like a snow angel with arms outstretched. A pretty space image for the holidays. The bipolar star-forming region is called Sharpless 2-106.

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Scientists explain how gold nanoparticles easily penetrate cells, making them useful for delivering drugs

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A special class of tiny gold particles can easily slip through cell membranes, making them good candidates to deliver drugs directly to target cells. A new study from MIT materials scientists reveals that these nanoparticles enter cells by taking advantage of a route normally used in vesicle-vesicle fusion, a crucial process that allows signal transmission between neurons. In the July 21 issue of Nature Communications, the researchers describe in detail the mechanism by which these nanoparticles are able to fuse with a membrane. The findings suggest possible strategies for designing nanoparticles — made from gold or other materials — that could get into cells even more easily. “We’ve identified a type of mechanism that might be more prevalent than is currently known,” says Reid Van Lehn, an MIT graduate student in materials science and engineering and one of the paper’s lead authors. “By identifying this pathway for the first time it also suggests not only how to engineer this particular class of nanoparticles, but that this pathway might be active in other systems as well.” The paper’s other lead author is Maria Ricci of École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. The research team, led by Alfredo Alexander-Katz, an associate

The post Scientists explain how gold nanoparticles easily penetrate cells, making them useful for delivering drugs has been published on Technology Org.

 
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CERN prepares beam line for schools

Hubble finds supernova star system linked to potential 'zombie star'

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Astronomers have spotted a star system that could have left behind a "zombie star" after an unusually weak supernova explosion. A supernova typically obliterates the exploding white dwarf, or dying star. On this occasion, scientists believe this faint supernova may have left behind a surviving portion of the dwarf star -- a sort of zombie star.

via Science Daily

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Pale Blue Dot Clean Posters

Here's a great poster featuring a beautiful image from deep space


tagged with: pale, blue, dot, space, astronomy, earth

The pixelation from the hubble scope are cleaned up in this one to look a little more wall art friendly.

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via Zazzle Astronomy market place

Galactic Love Wall Decals

Here's a great wall decal featuring a beautiful image from deep space


tagged with: nebula, space, astronomy, galaxy, galaxies, creation, god, glory, bleu, aqua, black, yellow, wall, decals, posters, square, gray, blue, brown, eye, heart, cross, green

Galaxies, nebulas portals. Majestic and beautiful. Heart and Cross Psalm 19:1 The heavens declare the glory of God; the skies proclaim the work of his hands.

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Hubble Sees a Cosmic Caterpillar Cases For iPad

Here's a great iPad case from Zazzle featuring a Hubble-related design. Maybe you'd like to see your name on it? Click to personalize and see what it's like!


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.

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