Category Archives: Science

Photovoltaics from Any Semiconductor

Berkeley Lab Technology Could Open Door to More Widespread Solar Energy Devices

A technology that would enable low-cost, high efficiency solar cells to be made from virtually any semiconductor material has been developed by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley. This technology opens the door to the use of plentiful, relatively inexpensive semiconductors, such as the promising metal oxides, sulfides and phosphides, that have been considered unsuitable for solar cells because it is so difficult to tailor their properties by chemical means. (more…)

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Entropy Can Lead to Order, Paving The Route to Nanostructures

ANN ARBOR, Mich.— Researchers trying to herd tiny particles into useful ordered formations have found an unlikely ally: entropy, a tendency generally described as “disorder.”

Computer simulations by University of Michigan scientists and engineers show that the property can nudge particles to form organized structures. By analyzing the shapes of the particles beforehand, they can even predict what kinds of structures will form.

The findings, published in this week’s edition of Science, help lay the ground rules for making designer materials with wild capabilities such as shape-shifting skins to camouflage a vehicle or optimize its aerodynamics. (more…)

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Some Harmful Effects of Light at Night Can Be Reversed, Study Finds

COLUMBUS, Ohio – Chronic exposure to dim light at night can lead to depressive symptoms in rodents – but these negative effects can be reversed simply by returning to a standard light-dark cycle, a new study suggests.

While hamsters exposed to light at night for four weeks showed evidence of depressive symptoms, those symptoms essentially disappeared after about two weeks if they returned to normal lighting conditions.

Even changes in the brain that occurred after hamsters lived with chronic light at night reversed themselves after returning to a more normal light cycle. (more…)

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Study Determines Theoretical Energy Benefits and Potential of Algae Fuels

AUSTIN, Texas — It’s theoretically possible to produce about 500 times as much energy from algae fuels as is needed to grow the fuels, according to a new study by researchers at The University of Texas at Austin.

However, limited by existing technology, the researchers found in a separate study that their algae growing facility is getting out about one-five hundredth as much energy as it currently puts in to grow the fuels.

“The search for cost-effective biofuels is one of the noble endeavors of our time, and these papers shed insight on where the boundaries are in algae research,” said Robert Hebner, a professor in the Cockrell School of Engineering and director of the Center for Electromechanics. “One of the responsibilities of a top research university is to discover and explain what the boundaries are so we can innovate within those boundaries or create ways to expand them.” (more…)

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Diamond in The Rough: Half-Century Puzzle Solved

A Yale-led team of mineral physicists has for the first time confirmed through high-pressure experiments the structure of cold-compressed graphite, a form of carbon that is comparable in hardness to its cousin, diamond, but only requires pressure to synthesize. The researchers believe their findings could open the way for a super hard material that can withstand great force and can be used — as diamond-based materials are now — for many electronic and industrial applications. The study appears in Scientific Reports, a Nature journal.

Under normal conditions, pure carbon exhibits vastly different physical properties depending on its structure. For example, graphite is soft, but diamond is one of the hardest materials known. Graphite conducts electricity, but diamond is an insulator. (more…)

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Mice Have System to Handle Smell of Fear

Mice appear to have a specialized system for detecting and at least initially processing instinctually important smells such as those that denote predators. The finding raises a question about whether their response to those smells is hardwired.

PROVIDENCE, R.I. [Brown University] — A new study finds that mice have a distinct neural subsystem that links the nose to the brain and is associated with instinctually important smells such as those emitted by predators. That insight, published online this week in Proceedings of the National Academy of Sciences, prompts the question whether mice and other mammals have specially hardwired neural circuitry to trigger instinctive behavior in response to certain smells.

In the series of experiments and observations described in the paper, the authors found that nerve cells in the nose that express members of the gene family of trace amine-associated receptors (TAAR) have several key biological differences from the much more common and diverse neurons that express members of the olfactory receptor gene family. Those other nerve cells detect a much broader range of smells, said corresponding author Gilad Barnea, the Robert and Nancy Carney Assistant Professor of Neuroscience at Brown University. (more…)

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Going Big

UD researchers report progress in development of carbon nanotube-based continuous fibers

The Chou research group in the University of Delaware’s College of Engineering recently reported on advances in carbon nanotube-based continuous fibers with invited articles in Advanced Materials and Materials Today, two high impact scientific journals.

According to Tsu-Wei Chou, Pierre S. du Pont Chair of Engineering, who co-authored the articles with colleagues Weibang Lu and Amanda Wu, there has been a concerted scientific effort over the last decade to “go big” – to translate the superb physical and mechanical properties of nanoscale carbon nanotubes to the macroscale. (more…)

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Researchers Develop New Amp to Study the Universe

Researchers at NASA’s Jet Propulsion Laboratory and the California Institute of Technology, both in Pasadena, have developed a new type of amplifier for boosting electrical signals. The device can be used for everything from studying stars, galaxies and black holes to exploring the quantum world and developing quantum computers.

“This amplifier will redefine what it is possible to measure,” said Jonas Zmuidzinas, chief technologist at JPL, who is Caltech’s Merle Kingsley Professor of Physics and a member of the research team. (more…)

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