Earth

Many people anticipating the creation of an invisibility cloak might be surprised to learn that a group of American researchers has created 25 000 individual cloaks.

But before you rush to buy one from your local shop, the cloaks are just 30 micrometres in diameter and are laid out together on a 25 millimetre gold sheet.

Chinese researchers have designed and tested simulations of a "nanoclutch," a speed regulation tool for nanomotors. The nanoclutch consists of two carbon nanotubes (CNTs), one inside the other, separated by a film of water. Electrowetting forces control the friction between the water and the inner and outer walls of the CNTs. When the two tubes are electrically charged, the water confined between them can transmit the torque from the inner tube to the outer tube, and the device is said to be in the engaged state. When the CNTs are uncharged, the device is in the disengaged state.

Scientists at the Georgia Institute of Technology achieved a 17-percent increase in boiling efficiency by using an acoustic field to enhance heat transfer. The acoustic field does this by efficiently removing vapor bubbles from the heated surface and suppressing the formation of an insulating vapor film. As reported in the American Institute of Physics' (AIP) journal the Physics of Fluids, bubble removal was enhanced because the acoustic field induces capillary waves on the bubble, causing its contact line to contract and detach the bubble from the surface.

Researchers from Vestfold University College in Norway have created a simple, efficient energy harvesting device that uses the motion of a single droplet to generate electrical power. The new technology could be used as a power source for low-power portable devices, and would be especially suitable for harvesting energy from low frequency sources such as human body motion, write the authors in a paper accepted to the American Institute of Physics' (AIP) journal Applied Physics Letters.

Porous ceramic water filters are often coated with colloidal silver, which prevents the growth of microbes trapped in the micro- and nano-scale pores of the filter. Other metals such as copper and zinc have also been shown to exhibit anti-microbial activity. Researchers from Princeton University in New Jersey used atomic force microscopy (AFM) measurements to study the adhesion interaction between Escherichia coli (E.

A forensic approach that links changes deep below a volcano to signals at the surface is described by scientists from the University of Bristol in a paper published today in Science. The research could ultimately help to predict future volcanic eruptions with greater accuracy.

Using forensic-style chemical analysis, Dr Kate Saunders and colleagues directly linked seismic observations of the deadly 1980 Mount St. Helens eruption to crystal growth within the magma chamber, the large underground pool of liquid rock beneath the volcano.

Science magazine has awarded a prize for Inquiry-Based Instruction to a Case Western Reserve University class that melds biology, computer modeling, mathematical analysis and writing.

"Dynamics of Biological Systems," taught by Biology Professor Hillel Chiel and three graduate assistants, abandons traditional lectures altogether in favor of learning by doing. The teachers call the class an example of the use of the continual improvement model in education.

GAINESVILLE, Fla. — Doping may be a no-no for athletes, but researchers in the University of Florida's physics department say it was key in getting unprecedented power conversion efficiency from a new graphene solar cell created in their lab.

CARNELIAN BAY, Calif. — Results of a new U.S. Geological Survey study conclude that faults west of Lake Tahoe, Calif., referred to as the Tahoe-Sierra frontal fault zone, pose a substantial increase in the seismic hazard assessment for the Lake Tahoe region of California and Nevada, and could potentially generate earthquakes with magnitudes ranging from 6.3 to 6.9. A close association of landslide deposits and active faults also suggests that there is an earthquake-induced landslide hazard along the steep fault-formed range front west of Lake Tahoe.

Sensors that work flawlessly in laboratory settings may stumble when it comes to performing in real-world conditions, according to researchers at the Department of Energy's Oak Ridge National Laboratory.

Physicists have trapped and cooled exotic particles called excitons so effectively that they condensed and cohered to form a giant matter wave.

This feat will allow scientists to better study the physical properties of excitons, which exist only fleetingly yet offer promising applications as diverse as efficient harvesting of solar energy and ultrafast computing.

It's not magic, but new materials designed by two Northwestern University researchers seem to exhibit magical properties. Some contract when they should expand, and others expand when they should contract.

When tensioned, ordinary materials expand along the direction of the applied force. The new metamaterials (artificial materials engineered to have properties that may not be found in nature) do the opposite when tensioned -- they contract. Other materials designed by the researchers expand when compressed.

Quantum physics and plant biology seem like two branches of science that could not be more different, but surprisingly they may in fact be intimately tied.

Boulder, Colo., USA – The Geological Society of America has posted a new batch of Geology papers online ahead of print (23 May 2012). Locations studied include the Rainy Lake zone, Ontario, Canada; the Black Sea; Lake Matano, Indonesia; the Great Bahama Bank; Lake Eyre, Australia; the Burullus Lagoon of the Nile Delta, Egypt; and Tungurahua volcano, Ecuador. Studies involve work both in the field and in the lab.

The influence of the ground beneath us on the air around us could be greater than scientists had previously thought, according to new research that links the long-ago proliferation of oxygen in Earth's atmosphere to a sudden change in the inner workings of our planet.