People living in Hong Kong’s towering skyscrapers may be away from the hustle and bustle of its notorious traffic-snarled streets but the effects of traffic emissions should not be ignored, says a ground-breaking research project led by King’s College London.
Researchers are investigating how much of the toxic exhaust fumes at street level are, in fact, still reaching residents living inside high-rise buildings hundreds of feet above. Findings from the two and a half year pilot research project could prove vital for the increasing number of people now living in crowded and severely polluted megacities as buildings continue to be constructed skywards.
Cephalopods, which include octopuses, squid and cuttlefish, are among nature’s most skillful camouflage artists, able to change both the color and texture of their skin within seconds to blend into their surroundings — a capability that engineers have long struggled to duplicate in synthetic materials. Now, a team of researchers has come closer than ever to achieving that goal, creating a flexible material that can change its color or fluorescence and its texture at the same time, on demand, by remote control.
Sharks Inspire Hospital Surfaces to Cut Infections
Transmission of bacterial infections, including MRSA and MSSA could be curbed by coating hospital surfaces with microscopic bumps that mimic the scaly surface of shark skin, according to research published in BioMed Central’s open access journal Antimicrobial Resistance and Infection Control.
The study modeled how well different materials prevented the spread of human disease bacteria through touching, sneezes or spillages. The micro-pattern, named Sharklet, is an arrangement of ridges formulated to resemble shark skin. The study showed that Sharklet harbored 94 percent less MRSA bacteria than a smooth surface, and fared better than copper, a leading antimicrobial material. The bacteria were less able to attach to Sharklet’s imperceptibly textured surface, suggesting it could reduce the spread of superbugs in hospital settings.
Strange Quantum Changes Studied Near Absolute Zero
Heat drives classical phase transitions — think solid, liquid and gas — but much stranger things can happen when the temperature drops. If phase transitions occur at the coldest temperatures imaginable, where quantum mechanics reigns, subtle fluctuations can dramatically transform a material.
Scientists from the U.S. Department of Energy’s Brookhaven National Laboratory and Stony Brook Univ. have explored this frigid landscape of absolute zero to isolate and probe these quantum phase transitions with unprecedented precision.
Image of the Week: Approach Creates Strong, Conductive Carbon Threads
The very idea of fibers made of carbon nanotubes is neat, but Rice Univ. scientists are making them neater — literally. The single-walled carbon nanotubes in new fibers created at Rice line up like a fistful of uncooked spaghetti through a process designed by chemist Angel Martí and his colleagues.
The tricky bit, according to Martí, whose lab reported its results this month in the journal ACS Nano, is keeping the densely packed nanotubes apart before they’re drawn together into a fiber. Left to their own devices, carbon nanotubes form clumps that are perfectly wrong for turning into the kind of strong, conductive fibers needed for projects ranging from nanoscale electronics to macro-scale power grids.
Understanding Physics of Fire Imperative for Space Safety
Unlike flames on Earth, which have a tear-drop shape caused by buoyant air rising in a gravitational field, flames in space curl themselves into tiny balls. Untethered by gravity, they flit around as if they have minds of their own. More than one astronaut conducting experiments for researchers on Earth below has been struck by the way flameballs roam their test chambers in a lifelike search for oxygen and fuel.
Biologists confirm that fire is not alive. Nevertheless, on Aug. 21, astronaut Reid Wiseman on the ISS witnessed some of the best mimicry yet.
Researchers at Chalmers Univ. of Technology have shown the use of sound to communicate with an artificial atom. They can thereby demonstrate phenomena from quantum physics with sound taking on the role of light. The results will be published in the journal Science.
The interaction between atoms and light is well known and has been studied extensively in the field of quantum optics. However, to achieve the same kind of interaction with sound waves has been a more challenging undertaking. The Chalmers researchers have now succeeded in making acoustic waves couple to an artificial atom. The study was done in collaboration between experimental and theoretical physicists.
Study of Salt Can Aid Building Conservation Efforts
Salt crystals are often responsible when buildings start to show signs of ageing. Researchers from the Institute for Building Materials at ETH Zurich have studied salt damage in greater depth and can now predict weathering processes more accurately.
Historic stone buildings are tourist magnets. The Jordanian rock city of Petra, the medieval town of Rhodes in the Aegean Sea and the sandstone temples at Luxor, Egypt, for example, attract hundreds of thousands of visitors each year. These cultural assets all have one thing in common: they suffer from weathering caused by salts. These crystallize inside the porous building materials and generate enough force for the stone to break or crumble. The same problem also occurs in concrete buildings in this country. Researchers at the Institute for Building Materials at ETH Zurich and at Princeton Univ. have now conducted an experiment to test the effect of salts under controlled conditions. They are hoping the results will help conservators and restorers of cultural assets to predict the weathering process of buildings.
A team of researchers has discovered a way to cool electrons to -228 C without external means and at room temperature, an advancement that could enable electronic devices to function with very little energy. The process involves passing electrons through a quantum well to cool them and keep them from heating. The team details their research in a paper in Nature Communications.
“We are the first to effectively cool electrons at room temperature. Researchers have done electron cooling before, but only when the entire device is immersed into an extremely cold cooling bath,” said Seong Jin Koh, an associate professor at UT Arlington in the Materials Science & Engineering Department, who has led the research. “Obtaining cold electrons at room temperature has enormous technical benefits. For example, the requirement of using liquid helium or liquid nitrogen for cooling electrons in various electron systems can be lifted.”
A team of scientists led by the Carnegie Institution’s Jacqueline Faherty has discovered the first evidence of water ice clouds on an object outside of our own Solar System. Water ice clouds exist on our own gas giant planets — Jupiter, Saturn, Uranus and Neptune — but have not been seen outside of the planets orbiting our Sun, until now. Their findings are published by The Astrophysical Journal Letters.
At the Las Campanas Observatory in Chile, Faherty, along with a team including Carnegie’s Andrew Monson, used the FourStar near infrared camera to detect the coldest brown dwarf ever characterized. Their findings are the result of 151 images taken over three nights and combined. The object, named WISE J085510.83-071442.5, or W0855, was first seen by NASA’s Wide-Field Infrared Explorer mission and published earlier this year. But it was not known if it could be detected by Earth-based facilities.
In the typical textbook picture, volcanoes, such as those that are forming the Hawaiian islands, erupt when magma gushes out as narrow jets from deep inside Earth. But that picture is wrong, according to a new study from researchers at Caltech and the Univ. of Miami.
New seismology data are confirming that such narrow jets don’t actually exist, says Don Anderson, the Eleanor and John R. McMillian Professor of Geophysics, Emeritus, at Caltech. In fact, he adds, basic physics doesn’t support the presence of these jets, called mantle plumes, and the new results corroborate those fundamental ideas.
A quantum effect in which excited atoms team up to emit an enhanced pulse of light can be turned on its head to create super-absorbing systems to make the ultimate camera.
Superradiance, a phenomenon where a group of atoms charged up with energy act collectively to release a far more intense pulse of light than they would individually, is well-known to physicists. In theory the effect can be reversed to create a device that draws in light ultra-efficiently. This could be revolutionary for devices ranging from digital cameras to solar cells. But there’s a problem: the advantage of this quantum effect is strongest when the atoms are already 50 percent charged – and then the system would rather release its energy back as light than absorb more.
An experiment at the Department of Energy’s SLAC National Accelerator Laboratory has revealed a well-organized 3-D grid of quantum “tornadoes” inside microscopic droplets of super-cooled liquid helium. This is the first time this formation has been seen at such a tiny scale.
The findings by an international research team provide new insight on the strange nanoscale traits of a so-called “superfluid” state of liquid helium. When chilled to extremes, liquid helium behaves according to the rules of quantum mechanics that apply to matter at the smallest scales and defy the laws of classical physics. This superfluid state is one of just a few examples of quantum behavior on a large scale that makes the behavior easier to see and study.
Anyone who has ever had a glass of fizzy soda knows that bubbles can throw tiny particles into the air. But in a finding with wide industrial applications, Princeton researchers have demonstrated that the bursting bubbles push some particles down into the liquid as well.
"It is well known that bursting bubbles produce aerosol droplets, so we were surprised, and fascinated, to discover that when we covered the water with oil, the same process injected tiny oil droplets into the water," said Howard Stone, professor of mechanical and aerospace engineering at Princeton and the lead researcher for the project.