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By Admin (from 03/06/2011 @ 14:00:35, in en - Science and Society, read 1844 times)

People who have strokes are often left with moderate to severe physical impairments. Now, thanks to a glove developed at McGill, stroke patients may be able to recover hand motion by playing video games. The Biomedical Sensor Glove was developed by four final-year McGill Mechanical Engineering undergrads under the supervision of Professor Rosaire Mongrain. It is designed to allow patients to exercise in their own homes with minimal supervision, while at the same time permitting doctors to monitor their progress from a distance, thus cutting down on hospital visits and costs.

Patients can monitor their progress thanks to software which will generate 3D models and display them on the screen, while at the same time sending the information to the treating physician.

The glove was developed by the students in response to a design request from the startup company Jintronix Inc. The students met with company representatives once a week for several months to develop the glove, which can track the movements of the wrist, the palm and the index finger using several Inertial Measurement Units. Although similar gloves currently exist, they cost approximately $30,000.

By using more accurate and less expensive sensors, the students were able to develop a glove that currently costs $1000 to produce.  Jintronix, Inc. has submitted the project to Grand Challenges Canada, which is an independent not-for-profit organization dedicated to improving the health and well-being of people in developing countries, in the hopes that they will receive funding for further development.

Source: physorg

Provided by McGill University for ZeitNews.org

 

A little rain or fog may seem like an insignificant threat to a helicopter or airplane. But minor clouds and precipitation can be the cause of canceled flights -- or fatalities.

It's dangerously easy for water droplets to turn to ice and coat an airplane’s wings, unless something could prevent the ice from adhering, lessening or eliminating the problem.

That's what Ed Smith has dedicated his time and research to for the past decade.

"The basic problem is when you fly through an icing cloud, which is about freezing temperature and has water in the cloud, and water of a certain size, [the particles] hit and start forming," Smith, professor of aerospace engineering and director of the Penn State Rotorcraft Center of Excellence, explains. "They call it accreting on the surface of the blades—or the airplane itself—and it ruins the aerodynamic characteristics of the blades."

Smith, along with Jose Palacios, a research associate in aerospace engineering, run an adverse environment rotor test stand lab in Hammond Building. The idea was conceived 10 years ago and built in phases, Smith said.

The lab has two purposes, he says: to take measurements and quantify how ice builds up, in what shape and how fast it accretes; and to test how tightly ice grips to the surface of the blade, something they call "adhesion strength."

With the help of donated equipment from Boeing, Smith and his associates remodeled the lab. It was previously the high temperature testing lab before it was handed over to the Department of Aerospace Engineering.

After installing a motor, drive system and freezer in the lab, researchers spent the last three years completing the complicated process of creating an ice cloud. Smith and his researchers sought the help of NASA's icing center in Cleveland, which provided them with a series of nozzles required to create the cloud.

Besides NASA and Boeing, the lab has numerous sponsors that help fund its research: the Army, Navy and Goodrich, as well as several small companies in State College, including FBS, Inc.

The past year has seen substantial progress not only in verifying that the lab is getting proper icing conditions and proper icing shapes with its equipment, but also with the ice protection system itself—a new system involving ultrasound technology, instead of the existing electrothermal system.

"The current way ice protection is done is with heat. They imbed little heater elements just under the skin of the blade," Smith explains. But these systems are heavy and unreliable, and they use enormous amounts of power. This allows only the largest helicopters to even attempt to use them, meaning most helicopters simply can't fly in any type of icing condition in the winter.

Airplanes, however, have hot engines to help prevent icing. Many planes have a sophisticated system that uses the engines’ hot air to blow over the inlets, melting ice, Smith said -- but the systems are no guarantee.

"You always hear every winter, 'icing results in the crash of an airplane,'" Smith says. "If the ice forms on part of the blade and not the others, you can really have bad vibration problems, so it's a lot of fatalities over the last several decades. Usually either the ice protection system didn’t come on or it didn't work right."

For helicopters, no such hot air or de-icing system exists for its rotor blades. Ice can form, weighing down the rotor and causing blades to shed off. This leads to violent shaking, much like if one would attach a weighted object to a blade on a ceiling fan, Smith says.

Fortunately, he says the new ultrasound system has been very promising over the last eight years, since he and researchers started working on it.

Smith describes the new process as a mechanical stress—the ice forms on the blade and the blade shakes back and forth at high speeds, peeling the ice off.

"It's the same thing you're really doing when you use an ice scraper, hit the ice at an angle and shear it off, that's what it's doing."

Now, Smith says his team is working to develop the technology to make it work in a practical way. In addition to helicopters, it could be relevant to airplanes, engine inlets, wing turbines—anything that is outside and subject to the elements.

Another aspect of the system is a new, efficient way to evaluate the condition of the blades, further improving a helicopter's safety. The technology uses a piece of metal located in the front of each rotor blade intended to balance their center of gravity, Smith says.

The idea is to remove that and replace it with a ceramic material, which has the same density of lead. "We take this mass out and replace it with something that can move at high frequencies ... in this case, we take advantage of the fact that all blades and wings have this mass in the leading edge that don't do anything useful except moving the center of gravity forward," Smith explains. "So now we can make better use out of a heavy material in the nose—we think that is very attractive."

When blades and wings are manufactured, they are inspected using ultrasonic CAT scans to make sure there are no cracks and the bonds are in good shape. But usually, Smith says, they're never inspected again after they leave the factory.

The ceramic masses, however, serve as ultrasonic transducers and can double as vehicles for periodic inspection for damage, in addition to de-icing aids.

So far, Smith says he doesn't have any patents for the technology he's helped develop. Though he has filed several invention disclosures over the last few years, he says the university gets many invention disclosures and can only choose a certain number to pursue a patent. But that doesn't bother him.

"So far, we haven't had our disclosures picked up; a lot of things are in public domain," he says. "I'm personally not motivated by patents—that drives some people nuts. That's not what's driving us; we want to educate the community."

Smith says his lab's new ultrasound system could be useful, but implementing it would be tricky due to the decades-long history with the current, electrothermal system.

"It's kind of like a hybrid car—it takes a long time. You're so used to a gasoline engine, if you want to switch over, there are a lot of questions people have to ask before you can just replace everything," he explains. "We're trying to answer as many of those questions as we can."

Source: physorg

Provided by Pennsylvania State University for ZeitNews.org

 

A flexible, controllable trailing edge for wind turbine blades has shown that it can reduce the loads on the turbine and in the end provide cheaper electricity from wind power.

The idea dates back to 2003 when researchers from Risø DTU was inspired by the prey's ability to maneuver in turbulent air currents, while they at the same time remained at a stable point in the air. Now a three-year project, with three industry partners, is launched and is to develop the promising technology forward to a robust and durable trailing edge which can be tested on a full-scale blade.

The fierce gusts and turbulence, such as wind turbines are exposed to constantly, contribute significantly to the cost of producing electricity from wind turbines. The turbines must be designed to resist these influences throughout their lifespan of at least 20 years since repairs are costly, especially when the turbines are located far out at sea and are more than 100 meters high. Therefore, researchers and industry are aimed at finding technical solutions that can alleviate the loads on the turbines.

"We have already had a good start of the project with our first project meeting in early March. The composition of project partners is well suited in order to solve the challenges in the project" says Research Specialist and Project Manager Helge Aagaard Madsen from Risø DTU.

Robust, reliable and durable

The buzz words for the project are to develop a technology that is: robust, reliable and durable. The specific solution that has been under development at Risø since 2006, supported by funds from Region Zealand, is a flexible trailing edge of rubber or plastic. Movement of the trailing edge is achieved by elastic deformations caused by fiber reinforced cavities that run through the rear and can be pressurized with air or hydraulics. It is these controlled movements that counteract the forces from the fierce wind gusts.

"The technology has already been tested under laboratory conditions and in a wind tunnel with promising results. Now the task is to have a prototype produced by the end of project that is ready for testing on a full-scale turbine "explains Research Specialist Helge Aagaard Madsen and continues:

"We want to develop and produce prototypes in 2m-long rubber or plastic in the project, depending on what's most robust and give the best result."

The three industrial partners in the project each contribute specific knowledge in key areas. Eg AVN is already experts in the hydraulic systems that are currently used for turbine pitch systems. Since AVN develops, manufactures and sells these systems for different wind turbine manufacturers they can contribute with a unique understanding of how the new flaps systems can operate together with the pitch system.

"The pitch system is what rotate the blades today so that they are positioned optimal towards the wind, but it costs both loads and energy to turn a 15-ton rotor blade as compared to what it will 'cost' for our small local movements with a flexible blade trailing edge that perhaps only has a weight of 1% of the blade's total weight, "explains Helge Aagaard Madsen.

The other two project partners is Rehau, that among other supplies plastic parts for the car industry and Dansk Gummi Industri which manufactures molded rubber and polyurethane to the industry. Rehau will contribute to develop the new materials that the trailing edge can be manufactured from, and the Dansk Gummi Industri will work on the production side of the trailing edge also called CRTEF (Controllable Rubber Trailing Edge Flap).

No mechanical parts

The flexible trailing edge is entirely without mechanical parts and we hope completely to avoid metal parts. And this part is important. Helge Aagaard Madsen explains:

"It is important that the technologies we develop now are virtually maintenance free. It is of no use to add another component on the turbine that needs a lot of maintenance and can break. This is also why it is very important that we have a good collaboration with the industry from this early stage. In this way we can ensure that the product matches what the industry needs and wants. Both when it comes to the production and the application side. "

From Risø DTU experts in wind turbines contribute, but also the expertise of the material scientists' is in focus, as there is great need for knowledge on fiber reinforcements and composite materials. From DTU Electrical Engineering researchers also contribute with knowledge about lightning, since wind turbines due to their height have an elevated risk of being hit by lightning. This factor must of course also be taken into account when the prototype developed.

Source: physorg

Provided by Technical University of Denmark for ZeitNews.org

 
By Admin (from 27/05/2011 @ 14:00:12, in en - Science and Society, read 2959 times)

A retina made in a laboratory in Japan could pave the way for treatments for human eye diseases, including some forms of blindness.

Created by coaxing mouse embryonic stem cells into a precise three-dimensional assembly, the 'retina in a dish' is by far and away the most complex biological tissue engineered yet, scientists say.

"There's nothing like it," says Robin Ali, a human molecular geneticist at the Institute of Ophthalmology in London who was not involved in the study. "When I received the manuscript, I was stunned, I really was. I never thought I'd see the day where you have recapitulation of development in a dish."

If the technique, published today in Nature (This article is reproduced with permission from the magazine Nature. The article was first published on April 6, 2011. - TA note), can be adapted to human cells and proved safe for transplantation -- which will take years -- it could offer an unlimited well of tissue to replace damaged retinas. More immediately, the synthetic retinal tissue could help scientists in the study of eye disease and in identifying therapies.

The work may also guide the assembly of other organs and tissues, says Bruce Conklin, a stem-cell biologist at the Gladstone Institute of Cardiovascular Disease in San Francisco, who was not involved in the work. "I think it really reveals a larger discovery that's coming upon all of us: that these cells have instructions that allow them to self-organize."

Cocktail recipe

In hindsight, previous work had suggested that, given the right cues, stem cells could form eye tissue spontaneously, Ali says. A cocktail of genes is enough to induce frog embryos to form form eyes on other parts of their body, and human embryonic stem cells in a Petri dish can be coaxed into making the pigmented cells that support the retina, sheets of cells that resemble lenses and light-sensing retinal cells themselves.

However, the eye structure created by Yoshiki Sasai at the RIKEN Center for Developmental Biology in Kobe and his team is much more complex.

The optic cup is brandy-snifter-shaped organ that has two distinct cell layers. The outer layer -- that nearest to the brain -- is made up of pigmented retinal cells that provide nutrients and support the retina. The inner layer is the retina itself, and contains several types of light-sensitive neuron, ganglion cells that conduct light information to the brain, and supporting glial cells.

To make this organ in a dish, Sasai's team grew mouse embryonic stem cells in a nutrient soup containing proteins that pushed stem cells to transform into retinal cells. The team also added a protein gel to support the cells. "It's a bandage to the tissue. Without that, cells tend to fall apart," Sasai says.

At first, the stem cells formed blobs of early retinal cells. Then, over the next week, the blobs grew and began to form a structure, seen early in eye development, called an optic vesicle. Just as it would in an embryo, the laboratory-made optic vesicle folded in on itself over the next two days to form an optic cup, with its characteristic brandy-snifter shape, double layer and the appropriate cells.

Even though the optic cups look and develop like the real thing, "there may be differences between the synthetic retina and what happens normally," Ali says.

Sasai's team has not yet tested whether the optic cups can sense light or transmit impulses to the mouse brain. "That's what we are now trying," he says. However, previous studies have suggested that embryonic retinas can be transplanted into adult rodents, so Sasai is hopeful.

Sasai, Ali and others expect that human retinas, which develop similarly to those of mice, could eventually be created in the lab. "In terms of regenerative medicine, we have to go beyond mouse cells. We have to make human retinal tissue from human embryonic stem cells and investigation is under way," Sasai says.

The eyes have it

Synthetic human retinas could provide a source of cells to treat conditions such as retinitis pigmentosa, in which the retina's light-sensing cells atrophy, eventually leading to blindness. In 2006, Ali's team found that retinal cells from newborn mice work when transplanted into older mice. Synthetic retinas, he says, "provide a much more attractive, more practical source of cells".

David Gamm, a stem-cell biologist at the University of Wisconsin, Madison, says that transplanting entire layers of eye tissue, rather than individual retinal cells, could help people with widespread retinal damage. But, he adds, diseases such as late-stage glaucoma, in which the wiring between the retina and brain is damaged, will be much tougher to fix.

When and whether such therapies will make it to patients is impossible to predict. However, in the nearer term, synthetic retinas will be useful for unpicking the molecular defects behind eye diseases, and finding treatments for them, Sasai says. Retinas created from reprogrammed stem cells from patients with eye diseases could, for instance, be used to screen drugs or test gene therapies, Ali says.

Robert Lanza, chief scientific officer of the biotechnology company Advanced Cell Technology, based in Santa Monica, California, says the paper has implications far beyond treating and modeling eye diseases. The research shows that embryonic stem cells, given the right physical and chemical surroundings, can spontaneously transform into intricate tissues. "Stem cells are smart," Lanza says. "This is just the tip of the iceberg. Hopefully it's the beginning of an important new phase of stem-cell research."

Source: ScientificAmerican

 
By Admin (from 26/05/2011 @ 14:00:42, in en - Science and Society, read 1302 times)

In an interesting feat of nanoscale engineering, researchers at Lund University in Sweden and the University of New South Wales have made the first nanowire transistor featuring a concentric metal 'wrap-gate' that sits horizontally on a silicon substrate.

Two remarkable aspects of their design are the simplicity of the fabrication and the unique ability to tune the length of the wrap-gate via a single wet-etch step, notes Associate Professor Adam Micolich, an ARC Future Fellow in the Nanoelectronics Group in the UNSW School of Physics.

Packing ever higher densities of transistors into a microchip comes at a hefty price – the reduced overlap between the semiconductor channel through which the current flows and the metal gate makes it harder to switch the current on and off.

This drove the development of the ‘Fin Field-Effect Transistor’, or FinFET, where the silicon either side of the channel is etched away to create a raised mesa structure. This allows the gate to fold down around the sides of the channel, improving the switching without increasing the chip space needed by the device. Even better control can be obtained by wrapping the gate all the way around the channel. But getting metal underneath the channel without compromising the device can be a formidable task using conventional ‘top-down’ silicon microfabrication techniques.

This has led to significant interest in self-assembled nanowires for computing applications (see D.K. Ferry, doi: 10.1126/science.1154446). These tiny semiconductor needles, around 50 nm in diameter and up to several microns in length, are grown using chemical vapour deposition and stand vertically on a semiconductor substrate, making it possible to deposit an insulator and gate metal around the nanowire’s entire outer surface.

Although these coated nanowires can be made into fully-functioning transistors in the vertical orientation, the process to achieve this is very involved. And in many cases, it is more desirable to have the nanowire transistor lying flat on the substrate, as with conventional silicon transistors. This poses an interesting challenge for nanotechnologists: Is it possible to make nanowire transistors with an all-around metal ‘wrap-gate’ that lay flat on a semiconductor substrate?

In work published this week in Nano Letters [Storm et al. doi:10.1021/nl104403g], the team not only demonstrate the first such horizontal wrap-gate nanowire transistors, but they demonstrate that they can be made using a remarkably simple process that allows them to precisely set the wrap-gate’s length using a single wet-etch step, without any need for further lithography.

Their approach exploits the etchant solution’s ability to undercut the resist and etch along the nanowire, producing gates that range in length from slightly less than the contact separation to as low as 100 nm, simply by tuning the etchant concentration. The resulting devices have excellent electrical performance and can be produced reliably with high yield.

Beyond being a significant advance in nanofabrication techniques, these devices open interesting new avenues for fundamental research.

The wrap-gated nanowires are ideal for studies of one-dimensional quantum transport in semiconductors, where remarkable phenomena such as electron crystallization and spin-charge separation may be observed. Additionally, the strong gate-channel coupling combined with an exposed gold wrap-gate surface offers interesting potential for sensing applications by utilising the established chemistry for binding antibodies and other polypeptides to gold surfaces.

Source: PhysOrg

 
By Admin (from 25/05/2011 @ 14:00:12, in en - Science and Society, read 1821 times)

A Stanford research team uses glowing nanopillars to give biologists, neurologists and other researchers a deeper, more precise look into living cells.

As words go, evanescent doesn't see enough use. It is an artful term whose beauty belies its true meaning: fleeting or dying out quickly. James Dean was evanescent. The last rays of a sunset are evanescent. All that evanesces, however, is not lost, as a team of Stanford researchers demonstrated in a recent article in Proceedings of the National Academy of Sciences. In fact, in the right hands, evanescence can have a lasting effect.

The Stanford team – led by chemist Bianxiao Cui and engineer Yi Cui (no relation), with scholars Chong Xie and Lindsey Hanson – have created a cellular research platform that uses nanopillars that glow in such a way as to allow biologists, neurologists and other researchers a deeper, more precise look into living cells.

"This novel system of illumination is very precise," said Bianxiao Cui, the study's senior author and assistant professor of chemistry at Stanford. "The nanopillar structures themselves offer many advantages that make this development particularly promising for the study of human cells."

Longstanding challenges

To comprehend the potential of this breakthrough, it is helpful to understand the challenges to earlier forms of molecular imaging, which shine light directly on the subject area rather than using backlighting, as in this approach.

Scientists hoping for better, smaller molecular imaging have for years been handcuffed by a physical limitation on how small an area they could focus on – an area known as the observation volume. The minimum observation volume has long been limited to the wavelength of visible light, about 400 nanometers. Individual molecules, even long proteins common in biology and medicine, are much smaller than 400 nanometers.

This is where evanescence comes in. The Stanford team has successfully employed quartz nanopillars that glow just enough to provide light to see by, but weak enough to punch below the 400-nanometer barrier. The field of light surrounding the glowing nanopillars – known as the "evanescence wave" – dies out within about 150 nanometers of the pillar. Voilà – a light source smaller than the wavelength of light. The Stanford researchers estimate that they have shrunk the observation volume to one-tenth the size of previous methods.
Particular promise

The Stanford nanopillar imaging technique is particularly promising in cellular studies for several reasons. First, it is non-invasive – it does not harm the cell that is being observed, a downfall of some earlier technologies. For instance, a living neuron can be cultured on the platform and observed over long periods of time.

Second, the nanopillars essentially pin the cells in place. This is promising for the study of neurons in particular, which tend to move over time due to the repeated firing and relaxation necessary for study.

Lastly, and perhaps most importantly, the Stanford team found that by modifying the chemistry on the surface of the nanopillars they could attract specific molecules they want to observe. In essence they can handpick molecules to study even within the crowded and complex environment of a human cell.

"We know that proteins and their antibodies attract each other," said Bianxiao Cui. "We coat the pillars with antibodies and the proteins we want to look at are drawn right to the light source – like prima donnas to the limelight."

Setting the scene

To create their nanopillars, the Stanford team members begin with a sheet of quartz, which they spray with fine dots of gold in a scattershot pattern – Jackson Pollock-style. They then etch the quartz using a corrosive gas. The gold dots shield the quartz directly below from the etching process, leaving behind tall, thin pillars of quartz.

A scanning electron microscope image of a cell grown over and interacting with nanopillars. Arrows indicate three nanopillars.

The researchers can control the height of the nanopillars by adjusting the amount of time the etching gas is in contact with the quartz and the diameter of the nanopillars by varying the size of the gold dots. Once the etching process is complete and the pillars are created, they add a layer of platinum to the flat expanse of quartz at the base of the pillars.
The setting is something out of a futuristic John Ford film – Monument Valley rendered in quartz crystal. All that is missing is a stagecoach and John Wayne. In this world, a wide desert of platinum stretches to the horizon, interrupted on occasion by transparent spikes of crystalline quartz that rise several hundred nanometers from the valley floor.

The Stanford researchers then shine a light from below their creation. The opaque platinum blocks most of the light, but a small amount travels up through the nanopillars, which glow against the dark field of platinum.

"The nanopillars look a bit like tiny light sabers," said Yi Cui, associate professor of materials science and engineering at Stanford, "but they provide just the right amount of light to allow scientists to do some pretty amazing stuff – like looking at individual molecules."

The team has created an exceptional platform for culturing and observing human cells. The platinum is biologically inert and the cells grow over and closely adhere to the nanopillars. The glowing spires then meet with fluorescent molecules within the living cell, causing the molecules to glow – providing the researchers just the light they need to peer inside the cells.

"So, not only have we found a way to illuminate volumes one-tenth as small as previous methods – letting us look at smaller and smaller structures – but we can also pick and choose which molecules we want to observe," said Yi Cui. "This could prove just the sort of transformative technology that researchers in biology, neurology, medicine and other areas need to take the next leap forward in their research."

Source: PhysOrg

 

Researchers at the University of Warwick have developed a gold plated window as the transparent electrode for organic solar cells. Contrary to what one might expect, these electrodes have the potential to be relatively cheap since the thickness of gold used is only 8 billionths of a metre.

This ultra-low thickness means that even at the current high gold price the cost of the gold needed to fabricate one square metre of this electrode is only around £4.5. It can also be readily recouped from the organic solar cell at the end of its life and since gold is already widely used to form reliable interconnects it is no stranger to the electronics industry.

Organic solar cells have long relied on Indium Tin Oxide (ITO) coated glass as the transparent electrode, although this is largely due to the absence of a suitable alternative. ITO is a complex, unstable material with a high surface roughness and tendency to crack upon bending if supported on a plastic substrate. If that wasn't bad enough one of its key components, indium, is in short supply making it relatively expensive to use.

An ultra-thin film of air-stable metal like gold would offer a viable alternative to ITO, but until now it has not proved possible to deposit a film thin enough to be transparent without being too fragile and electrically resistive to be useful.

Now research led by Dr Ross Hatton and Professor Tim Jones in the University of Warwick 's department of Chemistry has developed a rapid method for the preparation of robust, ultra-thin gold films on glass. Importantly this method can be scaled up for large area applications like solar cells and the resulting electrodes are chemically very well-defined.

Dr Hatton says "This new method of creating gold based transparent electrodes is potentially widely applicable for a variety of large area applications, particularly where stable, chemically well-defined, ultra-smooth platform electrodes are required, such as in organic optoelectronics and the emerging fields of nanoelectronics and nanophotonics."

The paper documents the team's success in creating this simple, practical and effective method of depositing the films onto glass, and also reports how the optical properties can be fine tuned by perforating the film with tiny circular holes using something as simple as polystyrene balls. The University of Warwick research team has also had some early success in depositing ultra-thin gold films directly on plastic substrates, an important step towards realising the holy grail of truly flexible solar cells. This innovation is set to be exploited by Molecular Solar Ltd, a Warwick spinout company dedicated to commercialising the discoveries of its academic founders in the area of organic solar cells.

Source: ScienceDaily

 
By Admin (from 20/05/2011 @ 08:00:42, in en - Science and Society, read 2038 times)

Quantum physicists from the University of Innsbruck (Austria) have set another world record: They have achieved controlled entanglement of 14 quantum bits (qubits) and, thus, realized the largest quantum register that has ever been produced. With this experiment the scientists have not only come closer to the realization of a quantum computer but they also show surprising results for the quantum mechanical phenomenon of entanglement.

The term entanglement was introduced by the Austrian Nobel laureate Erwin Schrödinger in 1935, and it describes a quantum mechanical phenomenon that while it can clearly be demonstrated experimentally, is not understood completely. Entangled particles cannot be defined as single particles with defined states but rather as a whole system. By entangling single quantum bits, a quantum computer will solve problems considerably faster than conventional computers. "It becomes even more difficult to understand entanglement when there are more than two particles involved," says Thomas Monz, junior scientist in the research group led by Rainer Blatt at the Institute for Experimental Physics at the University of Innsbruck. "And now our experiment with many particles provides us with new insights into this phenomenon," adds Blatt.

World record: 14 quantum bits

Since 2005 the research team of Rainer Blatt has held the record for the number of entangled quantum bits realized experimentally. To date, nobody else has been able to achieve controlled entanglement of eight particles, which represents one quantum byte. Now the Innsbruck scientists have almost doubled this record. They confined 14 calcium atoms in an ion trap, which, similar to a quantum computer, they then manipulated with laser light. The internal states of each atom formed single qubits and a quantum register of 14 qubits was produced. This register represents the core of a future quantum computer. In addition, the physicists of the University of Innsbruck have found out that the decay rate of the atoms is not linear, as usually expected, but is proportional to the square of the number of the qubits. When several particles are entangled, the sensitivity of the system increases significantly. "This process is known as superdecoherence and has rarely been observed in quantum processing," explains Thomas Monz. It is not only of importance for building quantum computers but also for the construction of precise atomic clocks or carrying out quantum simulations.

Increasing the number of entangled particles

By now the Innsbruck experimental physicists have succeeded in confining up to 64 particles in an ion trap. "We are not able to entangle this high number of ions yet," says Thomas Monz. “However, our current findings provide us with a better understanding about the behavior of many entangled particles." And this knowledge may soon enable them to entangle even more atoms.

Some weeks ago Rainer Blatt’s research group reported on another important finding in this context in the scientific journal Nature: They showed that ions might be entangled by electromagnetic coupling. This enables the scientists to link many little quantum registers efficiently on a micro chip. "All these findings are important steps to make quantum technologies suitable for practical information processing," Rainer Blatt is convinced.

The results of this work are published in the scientific journal Physical Review Letters.

More information: 14-Qubit Entanglement: Creation and Coherence. Thomas Monz, Philipp Schindler, Julio T. Barreiro, Michael Chwalla, Daniel Nigg, William A. Coish, Maximilian Harlander, Wolfgang Hänsel, Markus Hennrich, Rainer Blatt. Phys. Rev. Lett. 106, 130506 (2011) DOI:10.1103/PhysRevLett.106.130506

Source: physorg

Provided by University of Innsbruck

 
By Admin (from 19/05/2011 @ 08:00:44, in en - Science and Society, read 2462 times)

Tekniker-IK4 is taking part in a European project investigating new materials based on carbonaceous nanoparticles for application to sectors such as automobiles and construction.

A brake pedal able to detect the pressure of the driver's foot, a paint for vehicles resistant to scratching and with self-repairing capacity, self-lubricating engine components, a low-cost and fire-resistant construction panel or a thermal insulating foam with enhanced efficiency.

These are just some of the applications that can be generated by using new, value-added materials based on carbonaceous nanoparticles, and on the research of which Tekniker-IK4 technological centre is working within the remit of the European CarbonInspired Project.

The development of new materials with enhanced properties is a consequence of the fact that nanometric-sized materials present excellent and unique properties (mechanical, electrical, magnetic, optical, etc.), which enable their application to multiple sectors.

The project initiated its work this year by bringing together the skills of different bodies grouped into a consortium, and amongst which are, apart from the Basque centre, the Centre for Automotive Technology of Galicia (CTAG), the Association for Research into Plastics Materials (AIMPLAS), the Universidade de Aveiro (Portugal) and the Institut Polytechnique de Bordeaux (France).

One of the goals of the project, besides boosting research in a field that has multiple applications, is the creation of a network of transference between Spain, Portugal and the south of France for the application of these materials based on carbonaceous nanoparticles within the automotive and construction sectors.

The network of collaboration between public and private R+D+i centres created by CarbonInspired will act to transfer knowledge to the companies and will provide advice to companies in the southwest of Europe, especially to small and medium-sized companies, regarding the development of new carbonaceous nanoparticle-based products and processes.

Source: EurekAlert

 
By Admin (from 18/05/2011 @ 14:00:10, in en - Science and Society, read 2782 times)

Some people collect stamps and coins, but when it comes to sheer utility, few collections rival the usefulness of Rice University researcher Michael Deem's collection of 2.6 million zeolite structures.

Zeolites are materials -- including some natural minerals -- that act as molecular sieves, thanks to a Swiss-cheese-like arrangement of pores that can sort, filter, trap and chemically process everything from drugs and petroleum to nuclear waste. Zeolites are particularly useful as catalysts -- materials that spur chemical reactions. There are about 50 naturally occurring zeolites and almost three times as many man-made varieties.

Deem's database, which is described in a new paper that will be featured on the cover of an upcoming issue of the Royal Society of Chemistry's journal Physical Chemistry Chemical Physics, hints at the untapped possibilities for making even more synthetic zeolites.

"For many catalytic applications only a single material has been found," said Deem, the John W. Cox Professor in Biochemical and Genetic Engineering and professor of physics and astronomy. "Expanding the diversity of the zeolite structures would be helpful to improve performance in existing applications, to explore novel functions and to answer basic scientific questions."

Zeolites are useful because of the particular way atoms are mixed and arranged in their porous interiors. Based on these arrangements, zeolites can cause chemicals to react in particular ways, and even subtle changes in the arrangements can alter the reactions that are spurred. Deem's database was created to explore the many zeolite structures that are physically possible, and he said several researchers are already using the information to identify zeolites that could be used for carbon sequestration and other applications.

"Computational methods can play a stimulatory role in the synthesis of new zeolite materials," Deem said. "That is the motivation; that is the challenge that brings us back to zeolites time and again."

In 2007, Deem and his students used both supercomputers and unused computing cycles from more than 4,300 idling desktop PCs to painstakingly calculate every conceivable atomic formulation for zeolites. They created a database of more than 3.4 million atomic formulations of the porous silicate minerals.

In the current study, Deem, Rice graduate student Ramdas Pophale and Purdue University computational analyst Phillip Cheeseman designed tools to examine and compare the physical properties of each entry. Using these tools, they pared down the larger set by removing potential redundancies as well as "low-energy" structures that would either be unstable or impossible to synthesize.

For each of the 2.6 million remaining structures in the database, the team carried out calculations to find specific physical and chemical properties -- including X-ray diffraction patterns, ring-size distributions and dielectric constants -- that could help guide researchers interested in synthesizing them or in finding a new type of zeolite for a specific application.

Deem said the new database has been deposited in the publicly available Predicted Crystallography Open Database.

Source: physorg

Provided by Rice University

 
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