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75 articles from PhysOrg

Theoretically, two layers are better than one for solar-cell efficiency

Solar cells have come a long way, but inexpensive, thin film solar cells are still far behind more expensive, crystalline solar cells in efficiency. Now, a team of researchers suggests that using two thin films of different materials may be the way to go to create affordable, thin film cells with about 34% efficiency.

New research tool tracks political advertising on Facebook

Transparency in political ads is vital to ensuring safe and fair elections, but transparency is difficult if advertisers are not required to disclose details about targeting and sources of funding. While TV broadcasters must disclose information about political ads to the public, Facebook, which is used by nearly 70% of Americans and is a source of news for many users, faces no such federal...

Dust may have controlled ancient human civilization

When early humans began to travel out of Africa and spread into Eurasia over a hundred thousand years ago, a fertile region around the eastern Mediterranean Sea called the Levant served as a critical gateway between northern Africa and Eurasia. A new study, published in Geology, shows that the existence of that oasis depended almost entirely on something we almost never think about: dust.

Did our early ancestors boil their food in hot springs?

Some of the oldest remains of early human ancestors have been unearthed in Olduvai Gorge, a rift valley setting in northern Tanzania where anthropologists have discovered fossils of hominids that existed 1.8 million years ago. The region has preserved many fossils and stone tools, indicating that early humans settled and hunted there.

COVID-19 virus uses heparan sulfate to get inside cells

A molecule known as ACE2 sits like a doorknob on the outer surfaces of the cells that line the lungs. Since January 2020, researchers have known that SARS-CoV-2, the novel coronavirus that causes COVID-19, primarily uses ACE2 to enter these cells and establish respiratory infections. Finding a way to lock out that interaction between virus and doorknob, as a means to treat the infection, has...

Sub-nanoparticle catalysts made from coinage elements as effective catalysts

Due to their small size, nanoparticles find varied applications in fields ranging from medicine to electronics. Their small size allows them a high reactivity and semiconducting property not found in the bulk states. Sub-nanoparticles (SNPs) have an extremely small diameter of around 1 nm, making them even smaller than nanoparticles. Almost all atoms of SNPs are available and exposed for...

Solar cycle 25 is here. NASA, NOAA scientists explain what that means

Solar Cycle 25 has begun. During a media event on Tuesday, experts from NASA and the National Oceanic and Atmospheric Administration (NOAA) discussed their analysis and predictions about the new solar cycle—and how the coming upswing in space weather will impact our lives and technology on Earth, as well as astronauts in space.

Human white blood cells use molecular paddles to swim

Human white blood cells, known as leukocytes, swim using a newly described mechanism called molecular paddling, researchers report in the September 15th issue of Biophysical Journal. This microswimming mechanism could explain how both immune cells and cancer cells migrate in various fluid-filled niches in the body, for good or for harm.

New study helps characterise the fusion of metals

In recent years, a great deal of effort has been devoted to the study of the melting curve of elements at high pressure. This information is relevant, for example, for applications such as nuclear fission reactors that involve very high temperatures or very high pressures. Or to deepen the knowledge on the interior of planets. Understanding what happens to iron—and to other transition metals,...

Rare pattern observed in migrating common swifts

Compared with other migratory birds, the common swift follows a very unusual pattern when it migrates from the breeding areas in Europe to its wintering locations south of the Sahara. This is what researchers have observed in a major eleven-year international study of the birds.

Successful improvement of the catalytic activity of photosynthetic carbon dioxide fixing enzyme Rubisco

A research group consisting of Associate Professor Fukayama Hiroshi (Kobe University, Graduate School of Agricultural Science) and Professor Matsumura Hiroyoshi (Ritsumeikan University) et al. have succeeded in greatly increasing the catalytic activity of Rubisco, the enzyme which fixes carbon from CO2 in plant photosynthesis. The research team also hypothesized the mechanism which determines the...

Lab discovers small 'Cain-and-Abel' molecule

A new bacterial molecule with the unsavory tendency to track down and kill others of its own kind has been discovered in the human microbiome by researchers at Princeton's Department of Chemistry. Named Streptosactin, it is the first small molecule found to exhibit fratricidal activity.

Satellite images display changes in the condition of European forests

Rupert Seidl (Professor of Ecosystem Dynamics and Forest Management in Mountain Landscapes at TUM) and his colleague Cornelius Senf (lead author of the study) for the first time produced a high-resolution map of all openings in the canopy of European forests. They have analyzed more than 30,000 satellite images and identified more than 36 million areas where large trees have given way to open...

New on/off functionality for fast, sensitive, ultra-small technologies

How do you turn on and off an ultra-small component in advanced technologies? You need an actuator, a device that transmits an input such as electricity into physical motion. However, actuators in small-scale technologies to date have critical limitations. For example, if it's difficult to integrate the actuator into semiconductor electronics, real-world applications of the technology will be...

NASA Aqua satellite casts three eyes on sally and finds heavy rain potential

NASA's Aqua satellite analyzed the cloud top temperatures and water vapor content in Hurricane Sally as it crawls toward landfall, and found the potential for large amounts of rainfall, which, coupled with slow movement, can lead to catastrophic flooding. Two instruments provided three views of Sally's temperatures and water vapor that revealed the soaking capability of the slow-moving hurricane.

NASA satellite imagery shows Teddy consolidating

When a tropical cyclone consolidates, it means that it is getting more organized and its circulation is improving. An improved circulation helps make for a stronger storm. Infrared imagery from NASA's Aqua satellite showed that Teddy was consolidating in the Central North Atlantic Ocean.

When hurricanes temporarily halt fishing, marine food webs recover quickly

Fishing has a strong impact on coastal marine food webs, but it's a hard effect to measure. When Hurricane Harvey hit Texas in 2017, it temporarily halted fishing in one area of the Gulf Coast and set up a natural experiment for our team. We found that when the hurricane halted recreational fishing, populations of sport fish rebounded almost immediately, causing a cascade of effects throughout...