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Heart-Shaped Solar Farm

An extraordinary heart-shaped solar farm is set to be built on the Pacific island of New Caledonia.

The 2MW “Heart of New Caledonia” is being built by solar company Conergy and should start producing power for 750 homes from early next year. The plant, comissioned by local beverage company Froico SA, is expected to save around 2m tonnes of carbon dioxide emissions over its projected 25-year lifetime and reduce the French overseas territory’s dependence on oil, gas and coal, which generate the majority of its power today.

The eye-catching heart shaped installation is made up of 7,888 panels across the four-acre site on Grand Terre, New Caledonia’s largest island, with the design only visible from the air.

The design is inspired by the “Coeur de Voh”, or “Heart of Voh”, an area of nearby wild mangrove vegetation that has naturally taken the shape of a heart.

Reference: http://www.theguardian.com/
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Flexible Computer and Television Screens
Where Cant You Put One?

The latest OLED technology allows the screen to bent into a very tight radius with convex or concave. This opens the door for new creativity in design and application. You can wrap them around pillars, curve with a ceiling or wall, put them on the roof of a car ( inside or outside). I can see smart watches that will wrap with the curve of your wrist and enhanced reality glasses or even contact lens.

The could conceivable finally replace the newspaper as single sheet of easily rolled up OLED screen displays you favorite news sites in the language of your choice when you unroll it before your morning commute. Speaking of this the inside of buses, trains,planes and subways may change completely with this technology.

Reference: http://tek-think.com/

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Nanostructured glass surface as anti-glare, anti-reflective display for mobile devices

If you’ve ever tried to watch a video on a tablet on a sunny day, you know you have to tilt it at just the right angle to get rid of glare or invest in a special filter. But now scientists have developed a novel glass surface that reduces both glare and reflection, which continue to plague even the best mobile displays today.

On a very fine scale, they roughened a glass surface so it could scatter light and ward off glare but without hurting the glass’s transparency. Then the researchers etched nano-size teeth into the surface to make it anti-reflective. In addition to achieving both of these visual traits, the researchers showed the textured surface repelled water, mimicking a lotus leaf. Although the anti-glare roughening protects the nano-size glass teeth, further research is needed to ensure that the surface can withstand heavy touchscreen use, they say. They add that the method is inexpensive and can easily be scaled up for industry use.

Reference:
[1] DOI: 10.1021/am5013062
[2] http://www.nanowerk.com/
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This is awesome.... It made my day. 
I'm sure you will like it too.

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Facebook found that the emotion in posts is contagious. 
Those who saw positive content were, on average, more positive and less negative with their Facebook activity in the days that followed. The reverse was true for those who were tested with more negative postings in their News Feed.

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Graphene's multi-colored butterflies

Combining black and white graphene can change the electronic properties of the one-atom thick materials, University of Manchester researchers have found.

Writing in Nature Physics, a large international team led by Dr Artem Mishchenko and Sir Andre Geim from The University of Manchester shows that the electronic properties of graphene change dramatically if graphene is placed on top of boron nitride, also known as 'white graphite'.

One of the major challenges for using graphene in electronics applications is the absence of a band gap, which basically means that graphene's electrical conductivity cannot be switched off completely. Whatever researchers tried to do with the material so far, it remained highly electrically conductive.

A new direction that has recently emerged in graphene research is to try to modify graphene's electronic properties by combining it with other similar materials in multilayered stacks. This creates an additional landscape for electrons moving through graphene and, therefore, its electronic properties can change strongly.

The University of Manchester scientists have used capacitance measurements to probe these changes. They found that in combination with a magnetic field this creates numerous replicas of the original graphene spectrum. This phenomenon is known as the Hofstadter butterfly but it is the first time that well developed replica spectra have been observed.

The researchers found a wealth of unexpected physics in this new system. For example, the Hofstadter butterflies turned out to be strongly contorted, very different from the theoretical predictions. This happens because electrons feel not only the landscape but also each other, which modifies the butterfly.
Another phenomenon that the Manchester paper reports is that graphene starts behaving at very low temperatures like a tiny ferromagnet. Usually, the higher the magnetic field, the more magnetic graphene become. The Hofstadter butterfly in Manchester's capacitors leads to an unexpected oscillating behaviour of the ferromagnetism. As new replica spectra emerge and disappear, so does the ferromagnetism.

Dr Mishchenko said: "It is really a new nice electronic system both similar to and different from graphene. We expect many more surprises. Let us first understand what it is and then we start talking about possible applications."

Reference: 
http://phys.org/
doi:10.1038/nphys2979
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New method stabilizes common semiconductors for solar fuels generation

Researchers around the world are trying to develop solar-driven generators that can split water, yielding hydrogen gas that could be used as clean fuel. Such a device requires efficient light-absorbing materials that attract and hold sunlight to drive the chemical reactions involved in water splitting. Semiconductors like silicon and gallium arsenide are excellent light absorbers—as is clear from their widespread use in solar panels. However, these materials rust when submerged in the type of water solutions found in such systems.

Now Caltech researchers at the Joint Center for Artificial Photosynthesis (JCAP) have devised a method for protecting these common semiconductors from corrosion even as the materials continue to absorb light efficiently. The finding paves the way for the use of these materials in solar-fuel generators.

"For the better part of a half century, these materials have been considered off the table for this kind of use," says Nate Lewis, the George L. Argyros Professor and professor of chemistry at Caltech, and the principal investigator on the paper. "But we didn't give up on developing schemes by which we could protect them, and now these technologically important semiconductors are back on the table."

The research, led by Shu Hu, a postdoctoral scholar in chemistry at Caltech, appears in the May 30 issue of the journal Science.

In the type of integrated solar-fuel generator that JCAP is striving to produce, two half-reactions must take place—one involving the oxidation of water to produce oxygen gas; the other involving the reduction of water, yielding hydrogen gas. Each half-reaction requires both a light-absorbing material to serve as the photoelectrode and a catalyst to drive the chemistry. In addition, the two reactions must be physically separated by a barrier to avoid producing an explosive mixture of their products.

Historically, it has been particularly difficult to come up with a light-absorbing material that will robustly carry out the oxidation half-reaction. Researchers have tried, without much success, a variety of materials and numerous techniques for coating the common light-absorbing semiconductors. The problem has been that if the protective layer is too thin, the aqueous solution penetrates through and corrodes the semiconductor. If, on the other hand, the layer is too thick, it prevents corrosion but also blocks the semiconductor from absorbing light and keeps electrons from passing through to reach the catalyst that drives the reaction.

At Caltech, the researchers used a process called atomic layer deposition to form a layer of titanium dioxide (TiO2)—a material found in white paint and many toothpastes and sunscreens—on single crystals of silicon, gallium arsenide, or gallium phosphide. The key was that they used a form of TiO2 known as "leaky TiO2"—because it leaks electricity. First made in the 1990s as a material that might be useful for building computer chips, leaky oxides were rejected as undesirable because of their charge-leaking behavior. However, leaky TiO2 seems to be just what was needed for this solar-fuel generator application. Deposited as a film, ranging in thickness between 4 and 143 nanometers, the TiO2 remained optically transparent on the semiconductor crystals—allowing them to absorb light—and protected them from corrosion but allowed electrons to pass through with minimal resistance.


On top of the TiO2, the researchers deposited 100-nanometer-thick "islands" of an abundant, inexpensive nickel oxide material that successfully catalyzed the oxidation of water to form molecular oxygen.
The work appears to now make a slew of choices available as possible light-absorbing materials for the oxidation side of the water-splitting equation. However, the researchers emphasize, it is not yet known whether the protective coating would work as well if applied using an inexpensive, less-controlled application technique, such as painting or spraying the TiO2 onto a semiconductor. Also, thus far, the Caltech team has only tested the coated semiconductors for a few hundred hours of continuous illumination.

"This is already a record in terms of both efficiency and stability for this field, but we don't yet know whether the system fails over the long term and are trying to ensure that we make something that will last for years over large areas, as opposed to weeks," says Lewis. "That's the next step."


References: 

http://phys.org/
DOI: 10.1126/science.1251428
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New nanowire growth mechanism observed

A mechanism of growth of anisotropic metal oxides that was predicted 20 years ago has been observed for the first time by researchers at the University of Bristol. The work is described in an article published this week in Science.

The fabrication of nanowires of ternary and quaternary functional materials has become an important goal for their application in miniaturized circuits as diodes and transistors, coaxial gates and sensors.

The growth mechanisms are complex however and invariably proceed via a vapour-liquid-solid process which results in nanowires with a tapering morphology. A nanowire that tapers is undesirable for applications, as functionality would vary along the length, and perhaps even vanish, once a critical size was reached.

Dr Simon Hall and Rebecca Boston in the School of Chemistry, along with colleagues in the University of Birmingham and the National Institute for Materials Science in Tsukuba, Japan have successfully grown nanowires of a phase of the superconductor yttrium barium copper oxide that have a constant cross-sectional area.

In doing so, they engineered their syntheses to proceed via the so-called 'microcrucible mechanism' of crystal growth. This mechanism was first proposed to account for the growth of certain macroscopic metal oxide whiskers in 1994, but has never been observed at any length scale until now.

The team achieved the first observation of this growth mechanism by using a high-resolution transmission electron microscope with video capture and an in-situ furnace. This enabled them to directly observe molten nanoparticles of barium carbonate migrating through a porous yttrium and copper-rich matrix, catalysing nanowire outgrowth from nano-sized microcrucibles on reaching the surface.
Dr Simon Hall said: "Nanowires produced in this way will have the same physical properties along their entire length, leading to more uniform current-carrying ability, ferroic behaviour and tensile strength.

"This work could pave the way for the next generation of devices that use new, high-performance functional materials as their key component."

Reference: http://phys.org/

About the figure: Schematic showing the movement of molten barium-rich nanoparticles to the surface of an yttrium- and copper-rich matrix. The transmission electron microscope image confirms that this leads to outgrowth of yttrium barium copper oxide nanowires via the microcrucible mechanism.
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