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50 articles from PhysOrg

Six-wavelength spectroscopy can offer new details of surface of Venus

A trio of papers provide new insight into the composition and evolution of the surface of Venus, hidden beneath its caustic, high temperature atmosphere. Utilizing imaging from orbit using multiple wavelengths—six-band spectroscopy proposed as part of the VERITAS and EnVision missions—scientists can map the iron content of the Venusian surface and construct the first-ever geologic map.

Nanodiamond sensors can act as both heat sources and thermometers

A team of scientists from Osaka University, the University of Queensland and the National University of Singapore's Faculty of Engineering used tiny nanodiamonds coated with a heat-releasing polymer to probe the thermal properties of cells. When irradiated with light from a laser, the sensors acted both as heaters and thermometers, allowing the thermal conductivity of the interior of a cell to be...

Scientists identify nutrient that helps prevent bacterial infection

Scientists studying the body's natural defenses against bacterial infection have identified a nutrient—taurine—that helps the gut recall prior infections and kill invading bacteria, such as Klebsiella pneumoniae (Kpn). The finding, published in the journal Cell by scientists from five institutes of the National Institutes of Health, could aid efforts seeking alternatives to antibiotics.

Towards applications: ultra-low-loss on-chip zero-index materials

A refractive index of zero induces a wave vector with zero amplitude and undefined direction. Therefore, light propagating inside a zero-index medium does not accumulate any spatial phase advance, resulting in perfect spatial coherence. Such coherence brings several potential applications, including arbitrarily shaped waveguides, phase-mismatch-free nonlinear propagation, large-area single-mode...

Engineers find a way to control chemical catalysts with sculpted light

Like a person breaking up a cat fight, the role of catalysts in a chemical reaction is to hurry up the process—and come out of it intact. And, just as not every house in a neighborhood has someone willing to intervene in such a battle, not every part of a catalyst participates in the reaction. But what if one could convince the unengaged parts of a catalyst to get involved? Chemical reactions...

Cities can help migrating birds on their way by planting more trees and turning lights off at night

Millions of birds travel between their breeding and wintering grounds during spring and autumn migration, creating one of the greatest spectacles of the natural world. These journeys often span incredible distances. For example, the Blackpoll Warbler, which weighs less than half an ounce, may travel up to 1,500 miles between its nesting grounds in Canada and its wintering grounds in the Caribbean...

How hitchhiking worms choose their vehicles

Tiny worms that live inside fig trees use the fig wasp as a 'vehicle' to hitch rides from one tree to another by crawling into the wasp's gut without harming it. This relationship has existed for millions of years. But how do these worms‒called nematodes‒choose their wasp vehicles? What cues do they use to check for co-passengers? A new study from the Centre for Ecological Sciences (CES) at...

Physicists propose a new theory to explain one dimensional quantum liquids formation

Liquids are ubiquitous in Nature: from the water that we consume daily to superfluid helium which is a quantum liquid appearing at temperatures as low as only a few degrees above the absolute zero. A common feature of these vastly different liquids is being self-bound in free space in the form of droplets. Understanding from a microscopic perspective how a liquid is formed by adding particles one...

Large mammals make soil more fertile in tropical forests

The White-lipped peccary (Tayassu pecari) is a boar-like hoofed mammal found throughout Central and South America. These animals roam the forest in bands of 50 to 100 individuals, eating a wide variety of foods. In Brazil's Atlantic Rainforest, they prefer the fruit of the jussara palm Euterpe edulis.

Intertropical Convergence Zone limits climate predictions in the tropical Atlantic

The strongest climate fluctuation on time scales of a few years is the so-called El Niño phenomenon, which originates in the Pacific. A similar circulation pattern exists in the Atlantic, which scientists under the leadership of GEOMAR Helmholtz Centre for Ocean Research Kiel have studied in more detail. Their results, now published in the international journal Nature Communications, contribute...

Climate impacts on health and urban areas: Heatwaves and death rate

Over the last half-century, the probability of heat extreme events has changed by orders of magnitude in almost every region of the world, with occurrences that are now up to a hundred times more in respect to a century ago. Of all-natural disasters, extreme high temperature events are the main cause of weather-related mortality and they are also expected to be the main factor responsible for...

Understanding how sound waves travel through disordered materials

A team of researchers lead by the University of Tsukuba have created a new theoretical model to understand the spread of vibrations through disordered materials, such as glass. They found that as the degree of disorder increased, sound waves traveled less and less like ballistic particles, and instead began diffusing incoherently. This work may lead to new heat- and shatter-resistant glass for...

Scientists' discovery is paving the way for novel ultrafast quantum computers

Scientists at the Institute of Physics of the University of Tartu have found a way to develop optical quantum computers of a new type. Central to the discovery are rare earth ions that have certain characteristics and can act as quantum bits. These would give quantum computers ultrafast computation speed and better reliability compared to earlier solutions. The University of Tartu researchers...