X-ray analysis reveals lattice distortions are behind silver gallium telluride’s thermoelectric properties, a finding that could advance green technologies.
A model attributes the propagating bands that appear in a compressed porous medium to structural changes alone.
A model attributes the propagating bands that appear in a compressed porous medium to structural changes alone.
Porous media such as snow, sand, cereals—even bones—develop strikingly similar banded patterns when they’re squeezed. Those bands form when localized deformation zones propagate throughout the material. Understanding what triggers the universal and “material-agnostic” emergence of the bands is a common goal in disciplines including avalanche research, petroleum extraction, structural engineering, geophysics, and agriculture. Now, describing the phenomenon using a model based entirely on a collapsing-pore mechanism, Lars Blatny and his colleagues at the Swiss Federal Institute of Technology, Lausanne, and the University of Sydney, Australia, identify a common origin for these patterns. The result could lead to comprehensive continuum-mechanics models of porous media.
Blatny and his colleagues simulated a vertical 2D slice of an elastoplastic structure that was squeezed from above and below. The structure was perforated with regularly spaced square holes that composed 25% to 75% of its total area. By varying the solid area fraction and the structure’s elasticity and yield strength, the researchers examined how different porous structures deform when compressed at a constant speed. They identified six classes of compaction patterns and found that they could describe these classes entirely by two numbers that characterize the material’s properties and the speed at which the structure was compressed.
Researchers discover a new state-sponsored attack that exploits the “Follina” vulnerability in Microsoft Office to target governments in Europe, U.S.
Observer, backup youthful copy, playing the right piano notes, quantum states oh my.
Dr David Sinclair explain about through his lab experiments, why he thinks there is an observer/backup copy for our youthfulness and what are the possible identities he can think of in this clip.
David Sinclair is a professor in the Department of Genetics and co-director of the Paul F. Glenn Center for the Biology of Aging at Harvard Medical School, where he and his colleagues study sirtuins—protein-modifying enzymes that respond to changing NAD+ levels and to caloric restriction—as well as chromatin, energy metabolism, mitochondria, learning and memory, neurodegeneration, cancer, and cellular reprogramming.
Vortex rings, similar to smoke rings, have been observed in pulsing light before. Now, scientists have figured out how to make them on purpose with lasers, mirrors and special lenses.
Alzheimer’s disease has long thwarted our best efforts to pinpoint its underlying causes. Now, a new study in mice suggests that ‘poisonous flowers’ bulging with cellular debris could be the root source of one hallmark of the wretched disease and a beautifully sinister sign of a failing waste disposal system inside damaged brain cells.
The study, led by neuroscientist Ju-Hyun Lee of New York University (NYU) Langone, challenges the long-standing idea that the build-up of a protein called amyloid-beta between neurons is a crucial first step in Alzheimer’s disease, the most common form of dementia.
Instead, it suggests that damage to neurons may take root inside cells well before amyloid plaques fully form and clump together in the brain, a finding which could provide new therapeutic possibilities.
In 2008, when gasoline was even more expensive than it is today, the world dreamed of cars that could run on nothing but air.
Circa 2021
Unlike other plasma jet engines, this new Chinese one can actually work in the atmosphere. This could prove revolutionary for the aerospace industry.
