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Experiments Inform Study of Crowd Motion

By Guest PostJuly 29, 2012Scienceannual pilgrimage, brown university, crowd behavior, crowd cohesion, crowd motion, electromagnetism, experiment, laws, mathematics, mecca, sayles hall, sayles swarm, school of fish, the haj, william warren

To determine how crowd behavior emerges from individual actions, William Warren, professor of cognitive, linguistic, and psychological sciences, assembled his own crowds and engaged them in an unusual four-day experiment in Sayles Hall. The subjects were equipped with motion capture markers affixed like antennae to bike helmets.

PROVIDENCE, R.I. [Brown University] — What must the staid-faced University luminaries in those portraits around Sayles Hall have thought while they watched this scene play out for four days last week? Over and over, two to 20 young men and women in bike helmets adorned with what appeared to be five large antennae walked back and forth across a cardboard-covered floor. En route to goals marked by numbers just beneath the portraits, they dodged each other and arrangements of cardboard pillars. Each time they generated patterns of foot traffic. (more…)

Photovoltaics from Any Semiconductor

By Guest PostJuly 29, 2012Sciencephotovoltaic effect, semiconductor, solar cells, solar energy devices, solar technologies

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…)

Entropy Can Lead to Order, Paving The Route to Nanostructures

By Guest PostJuly 28, 2012Sciencedesigner materials, nanoparticles, nanostructures, polyhedral shape, shape shifting skins

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.” (more…)

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

By Guest PostJuly 27, 2012Sciencebrain, chronic exposure, depression, depressive disorder, depressive symptom, drug, hamster, harmful effects, hippocampus, light, light cycle, light dark cycle, night, protein, randy nelson, rodent, siberian hamsters, tnf, tnf inhibitor, tracy bedrosian, tumor necrosis factor, xpro1595, zachary weil

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…)

Diamond in The Rough: Half-Century Puzzle Solved

By Guest PostJuly 25, 2012Sciencecold compressed, conduct, Diamond, electricity, experiment, graphite, hard material, high pressure, industrial application, joseph panzik, m carbon, oakland university, optical technique, puzzle, raman spectroscopy, structure, symmetry, synthesize, university, xray diffraction, yale, yuejian wang

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…)

Mice Have System to Handle Smell of Fear

By Guest PostJuly 24, 2012Sciencegene choice, neural subsystem, olfactory bulb, olfactory receptor, perception of smell, 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. (more…)

Going Big

By Guest PostJuly 23, 2012Scienceamanda wu, behavior of materials, carbon nanotube, China, chou research group, composite applications, fiber, force, go big, macroscale, nanoscale, sensor, strain, strain rate, tsinghua university, tsu wei chou, university of delaware, van der waals, weibang lu

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…)

Researchers Develop New Amp to Study the Universe

By Guest PostJuly 23, 2012Scienceamplifier, scientific measurements, studying stars

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. (more…)

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