At CERN, the European Organisation for Nuclear Research in Geneva, an international research team led by the Paul Scherrer Institute PSI has conducted especially precise measurements of atmospheric chemistry. Through this study the researchers were able to show how harmful particulate matter arises from vehicular emissions and biomass combustion. Their findings are helping to make existing models of particle formation more accurate.

Kyoto, Japan -- The Mpemba effect, in which hot systems cool faster than cold ones under the same conditions, was first described by Aristotle more than 2,000 years ago. In 1963 it was rediscovered by Tanzanian student Erasto Mpemba, who observed it when preparing ice cream in a cooking class at school. Mpemba later collaborated with British physicist Denis Osborne on a paper that described its effect on water.

Since Mpemba and Osborne's influential research, further studies have demonstrated that the effect extends beyond simple liquids and can be observed in a variety of physical systems --even microscopic ones. Yet one fundamental challenge has persisted; the detection of the Mpemba effect depends on the choice of a specific distance measure.

An infinite number of distance measures exist, so observing the effect using one distance measure may not materialize within a finite time when evaluated with another. Conventional methods typically assess relaxation speed, which is the rate of return to equilibrium after a change in temperature -- by using a single monotone measure -- but this often leads to inconsistent results.

A research team led by Colorado State University has achieved a new milestone in 3D X-ray imaging technology.  The scientists are the first to capture high-resolution CT scans of the interior of a large, dense object – a gas turbine blade – using a compact, laser-driven X-ray source. The work is part of a larger vision to leverage high-intensity lasers for a wide range of uses, from studying inertial fusion energy to generating bright beams of GeV electrons and MeV x-rays.