Thursday 22 May 2014

Mastering chemical recipes to make new materials

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Mircea Dincă playfully describes his very serious work making new materials in MIT’s Department of Chemistry much like being a kid mixing and matching Legos. A self-described molecular engineer, Dincă assembles new materials from a variety of inorganic and organic building blocks, all carefully chosen to impart properties leading to a desired activity or function. As a synthetic chemist in his third year at MIT, Dincă is always looking for new ways to make new materials for a variety of applications. His ideas are inspired by his colleagues, his students, and his industry relationships that have been a part of his life since graduate school. Dincă’s PhD in hydrogen storage materials, from the University of California at Berkeley, was funded by General Motors as part of its interest in building hydrogen cars. Dincă’s love of chemistry began in seventh grade in his native Romania. “Having a dedicated teacher that did spectacular demonstrations with relatively limited regard for safety may have had something to do with that,” he jokes. But what may have begun from “spectacular demonstrations” has matured into a profession focused on producing lasting applications. Now he leads the Functional Inorganic and Organic Materials Group in the MIT Department of Chemistry. “Chemistry enables me

The post Mastering chemical recipes to make new materials has been published on Technology Org.

 
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Not all diamonds are forever: Researchers see nanodiamonds created in coal fade away in seconds

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(Phys.org) —Images taken by Rice University scientists show that some diamonds are not forever. The Rice researchers behind a new study that explains the creation of nanodiamonds in treated coal also show that some microscopic diamonds only last seconds before fading back into less-structured forms of carbon under the impact of an electron beam.



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How to motivate people, according to science

Science Focus

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Employees, spouses, kids — what does it take to get people motivated so you don't have to nag them?

Motivation is powerful. It predicts success better than intelligence, ability, or salary.

When tested in national surveys against such seemingly crucial factors as intelligence, ability, and salary, level of motivation proves to be a more significant component in predicting career success. While level of motivation is highly correlated with success, importantly, the source of motivation varies greatly among individuals and is unrelated to success. – Bashaw and Grant 1994 [The 100...

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 » see original post http://theweek.com/article/index/260726/how-to-motivate-people-according-to-science
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Sunken body clue to American origins

Science Focus

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The ancient remains of a teenage girl discovered in a flooded cavern in Mexico are providing additional insights on how the Americas came to be populated. 
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 » see original post http://www.bbc.co.uk/news/science-environment-27432234#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa
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How El NiƱo temporarily slows the Earth’s rotation

Science Focus

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Sea surface temperature anomaly (difference from average) during strong El Niño "Modoki" conditions in 2009-2010.

If the length of a day changed by fractions of a millisecond, it probably wouldn’t make you late for work—that’s still on you. But the speed of Earth’s rotation does very subtly change over time, influenced by a number of factors. Some of these are geological, as you might expect. But the Earth's rotation is also influenced by something we don't think of as being that substantial: the weather.

We’ve all seen an Olympic figure skater begin spinning, tuck his or her arms in, and accelerate to a nauseating velocity. This is conservation of momentum. The farther the skater's mass is spread from the axis of rotation, the greater the moment of inertia, and the more angular momentum they need to spin at a given rate. Pulling in your arms reduces the moment of inertia but not the angular momentum—the result is an increased rate of rotation.

The same thing can happen (with far less dramatic results, thankfully) when the mass of the Earth is redistributed, as happens when the crust moves during a particularly large earthquake. On longer time scales, the motion of tectonic plates, circulation in the mantle, or circulation in the outer core can also affect Earth’s moment of inertia.

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 » see original post http://feeds.arstechnica.com/~r/arstechnica/science/~3/rFzn9vl03FQ/
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A new look at the solid-liquid interface

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Interesting things happen at interfaces, and when solids meet liquids it is no exception. Understanding the complex phenomena that take place at this 'solid-liquid' interface could give us important clues about how to build better medical devices and longer-lasting batteries, but to date it has been difficult to get a handle on how chemical ions in the solution behave at this crucial juncture. Until now, that is.



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Carina Nebula - Breathtaking Universe Stickers

Here's a great sheet of stickers featuring a beautiful image from deep space


tagged with: crnneb, star nurseries, star clusters, galaxies, starfields, awesome astronomy photos, nebulae, carina nebula, eso, european southern observatory, vista

Galaxies, Stars and Nebulae series A fantastic astronomy photograph showing a panoramic view of the WR 22 and Eta Carinae regions of the Carina Nebula.

The picture was created from images taken with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile.

It's a stunning, mind-blowing, fantastic image that reveals a little of the wonder that is our universe.

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image code: crnneb

ESO/J. Emerson/VISTA www.eso.org
Reproduced under the Creative Commons Attribution 3.0 Unported license.

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A Halo for NGC 6164

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Beautiful emission nebula NGC 6164 was created by a rare, hot, luminous O-type star, some 40 times as massive as the Sun. Seen at the center of the cosmic cloud, the star is a mere 3 to 4 million years old. In another three to four million years the massive star will end its life in a supernova explosion. Spanning around 4 light-years, the nebula itself has a bipolar symmetry. That makes it similar in appearance to more common and familiar planetary nebulae - the gaseous shrouds surrounding dying sun-like stars. Also like many planetary nebulae, NGC 6164 has been found to have an extensive, faint halo, revealed in this deep telescopic image of the region. Expanding into the surrounding interstellar medium, the material in the halo is likely from an earlier active phase of the O star. The gorgeous skyscape is a composite of extensive narrow-band image data, highlighting glowing atomic hydrogen gas in red and oxygen in blue hues, with broad-band data for the surrounding starfield. NGC 6164 is 4,200 light-years away in the right-angled southern constellation of Norma.

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Resonant energy transfer from quantum dots to graphene

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Semiconductor quantum dots (QDs) are nanoscale semiconductors that exhibit size dependent physical properties. For example, the color (wavelength) of light that they absorb changes dramatically as the diameter decreases. Graphene is an atomically thick sheet of carbon atoms, arranged in a hexagonal lattice pattern. In this work, QDs have been combined with graphene to develop nanoscale photonic devices that can dramatically improve our ability to detect light.



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New technique tracks proteins in single HIV particle

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An interdisciplinary team of scientists from KU Leuven in Belgium has developed a new technique to examine how proteins interact with each other at the level of a single HIV viral particle. The technique allows scientists to study the life-threatening virus in detail and makes screening potential anti-HIV drugs quicker and more efficient. The technique can also be used to study other diseases. “Essentially, we have created a nano test tube out of an HIV virion, inside of which protein interactions can be studied,” says co-author Jelle Hendrix. Photo: Shutterstock Understanding how the human immunodeficiency virus (HIV) reproduces itself is crucial in the effort to fight the disease. Upon entering the bloodstream, HIV viral particles, or virions, ‘highjack’ individual immune cells. The virion binds to and then penetrates the immune cell. Once inside, the virion reprograms the genetic material of the immune cell to produce more HIV virions. In this way, HIV disables the disease-fighting ‘bodyguards’ in our blood and turns them into breeding machines for new HIV virions. Integrase plays a key role throughout this whole process: “Integrase is the HIV protein that causes the genetic material of HIV to link to that of the hijacked cell. It ensures

The post New technique tracks proteins in single HIV particle has been published on Technology Org.

 
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Graphene senses opioids, desalinates water, and generates electricity

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Generating electricity, desalinating water, and sensing trace chemicals are some of the uses of graphene just added to the growing list of this material's potential applications. They all feature graphene in a liquid environment, where one wouldn't expect it due to its hydrophobic nature.



Research at the University of Pennsylvania, published last month in the journal Nano Letters, pushes mass fabrication of graphene devices to new limits. The devices, fabricated by a scalable shadow-mask process, serve as fine biosensors for traces of opioids – drugs. The detection limit ranged down to 10 picograms per millileter of liquid.





Picture: Graphene biosensor for drugs, American Chemical Society.



The researchers employed the molecule naltrexone, which has a high affinity for opioids. Opioid molecules tend to bind to the naltrexone receptor in a liquid environment. The receptor was chemically attached to graphene transistors. In the experiment, the presence of opioids near graphene changed the conductivity of the transistors, showing up as a change in an electronic signal. The fabrication yield of more than 98%, the high sensitivity and specificity of the sensor make it a serious candidate for mass production of biosensors for any application in which the detection of opioids, such as alcohol or morphine is desired. The sensors featured arrays of hundreds of graphene transistors, all working in parallel, fabricated on standard graphene on silicon.



Around the same time, a new method for generating electricity, by simply dipping a piece of graphene sheet into a common ionic solution, was reported in Nature Communications ("Waving potential in graphene" ). This electric energy harvesting approach could be integrated into cost-effective, self-powered sensor designs, reported Nanowerk News.




Researchers showed that moving a sheet of graphene across the surface of an ionic liquid, such as regular sea water, produces a small amount of electricity. They show that with a piece of graphene about the size of a small ruler (2 x 10 square centimeters), the electric potential generated is approximately 100 millivolts and, while this is still a relatively small output, the authors demonstrate that it is enough to stimulate a sciatic nerve of a frog. Importantly, they also show that the electricity generated is proportional to the size of the graphene sheet and the dipping speed, suggesting that this device may be scalable, opening up its potential use as, for example, a tsunami monitor.



It seems that technology is getting closer to a real-life graphene water desalination filter, with latest research from Oak Ridge National Labs (ORNL) pointing to a durable graphene-based desalination membrane with 100 times better performance compared to current filters.



A year ago, we wrote about the idea to use graphene as a water desalination filter, based on nanopores in a graphene sheet. In the meantime, technology has moved faster than one would expect, with nanometer-sized pores becoming a reality in lab results. While this fast development could lead to a demonstration of such water filters in the near future, the current research from ORNL offers an alternative approach, based on graphene oxide, or more precisely graphene oxide frameworks (GOFs).



“This is basically sheets of oxidized graphene connected by specific chemical linkers from some of the oxidation sites,” said ORNL’s Bobby Sumpter. “Because it’s composed mainly of strongly bonded carbon, it doesn’t decompose in water and has good mechanical properties. It’s an exciting material with potential for numerous applications.”



Although the results up to date are only computer simulations, graphene oxide is readily available in large quantities and experiment should soon follow. There is good reason to go in this direction, as water desalination is one of the big obstacles of mankind, and the simulated GOF filters would desalinate water 100 times faster than current technology. Furthermore, the technique would be completely scalable.



To summarize, although hydrophobic, graphene is making itself comfortable in liquid environments. We think that graphene's use in generating electricity, detecting drugs in blood and filtering water is only the beginning of a broad field of research and application.




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Researcher aids understanding of collective excitations in MoS2

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The large direct band gap in a monolayer of MoS2 leads to the appearance of the interband dipolar mode which couples to the intraband plasmon. This result is useful for our understanding of the collective excitations in MoS2. The renormalized dipolar mode is close to its bare value, while coupling suppresses the plasmon mode.

via Science Daily

Very distant galaxy cluster confirmed

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The structures and star populations of massive galaxies appear to change as they age, but much about how these galaxies formed and evolved remains mysterious. Many of the oldest and most massive galaxies reside in clusters, enormous structures where numerous galaxies are found concentrated together. Galaxy clusters in the early universe are thought to be key to understanding the lifecycles of old galaxies, but to date astronomers have located only a handful of these rare, distant structures.

via Science Daily

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Violent stellar explosion: Stellar behemoth self-destructs in a Type IIb supernova

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For the first time, astronomers have direct confirmation that a Wolf-Rayet star -- sitting 360 million light years away -- died in a violent explosion known as a Type IIb supernova. Using the iPTF pipeline, researchers caught supernova SN 2013cu within hours of its explosion.

via Science Daily

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Microsatellites: Making light work of orbit and attitude control

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Microsatellites have to be very light – every gram counts. The same applies to the gyroscopes used to sense the satellite’s orientation when in orbit. A novel prototype is seven times lighter and significantly smaller than earlier systems.

via Science Daily

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A star cluster in the wake of Carina

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This colorful new image from the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile shows the star cluster NGC 3590. These stars shine brightly in front of a dramatic landscape of dark patches of dust and richly hued clouds of glowing gas. This small stellar gathering gives astronomers clues about how these stars form and evolve — as well as giving hints about the structure of our galaxy's pinwheeling arms.

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Trifid Nebula, Messier 16 Rectangle Sticker

Here's a great sheet of stickers featuring a beautiful image from deep space


tagged with: breathtaking astronomy images, star forming nebulae, trfdnbl, star nurseries, galaxies, nebulae, star factory, trifid nebula, star clusters, heavens, factories for stars, eso, vista, european southern observatory

Galaxies, Stars and Nebulae series A fantastic picture from our universe featuring the massive star factory known as the Trifid Nebula.

It was captured in all its glory with the Wide-Field Imager camera attached to the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in northern Chile.
So named for the dark dust bands that trisect its glowing heart, the Trifid Nebula is a rare combination of three nebulae types that reveal the fury of freshly formed stars and point to more star birth in the future. The field of view of the image is approximately 13 x 17 arcminutes.
It's an awe-inspiring, breathtaking image that reveals some of the wonder that is our universe.

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image code: trfdnbl

ESO/J. Emerson/VISTA www.eso.org
Reproduced under the Creative Commons Attribution 3.0 Unported license.

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