Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog – Page 3

Get the latest international news and world events from around the world.

Log in for authorized contributors

Scandium’s electrons may explain predicted room-temperature superconductivity

Scientists have confirmed the existence of a predicted room temperature superconductor, while explaining the microscopic mechanism that distinguishes it from a similar one discovered several years ago. The work, published in the journal Physical Review B, offers “a theoretical blueprint for the future design of superior superconductor hydrides” the physicists write.

High temperature superconductors have been a holy grail of materials sciences for decades. There has been success in finding metal clathrate superhydrides such as LaH10. (“Superhydrides” are hydrogen-rich materials.) In 2018 the discovery of its superconductivity was announced in a preprint; and half a year later in the journal Nature.

Its critical temperature, below which the material is superconducting (offers no resistance to an electric current, and magnetic fields are expelled from the material) was up to −13°C, a record high at the time, albeit at a pressure of 188 billion pascals (GPa)—1.9 million times the atmosphere’s surface pressure on Earth.

Crystal spacing predicts magnetic states in complex alloys better than electron count

In materials chemistry, identifying common parameters that can organize magnetic ground states across complex intermetallic compounds remains a central challenge. Researchers have long used chemically tunable parameters to control magnetic properties. One is valence-electron concentration, commonly discussed as the electron-per-atom (e/a) ratio. The e/a ratio has been widely used to classify magnetic ground states in metallic systems such as Heusler alloys and approximant crystals.

In gold (Au)-based Tsai-type approximant crystals, the e/a ratio has been found to control magnetic ground states, including long-range antiferromagnetic (AFM) and ferromagnetic (FM) orders, as well as the spin-glass state. Tsai-type compounds are generally described as structures built from clusters with multiple shells, in which the moment-bearing rare-earth element occupies an icosahedral site. The predictive power of e/a, however, is limited across different alloy families and constituent elements. Given the potential of quasicrystal-based intermetallics as platforms for exploring emerging magnetic phenomena, researchers need reliable, experimentally accessible parameters to identify and guide the development of their magnetic properties.

To address this gap, a research team led by Assistant Professor Farid Labib of the Research Institute for Science and Technology at Tokyo University of Science (TUS), Japan, and Associate Professor Kazuhiro Nawa of the Institute of Multidisciplinary Research for Advanced Materials at Tohoku University, Japan, along with Professor Ryuji Tamura of TUS, investigated whether the lattice parameter could serve as a unified structural parameter for magnetic ground state selection in Tsai-type icosahedral compounds.

Enantioresolution turns bright but racemic gold-silver clusters into circularly polarized emitters

Chiral metal clusters that emit circularly polarized light often face a trade-off between photoluminescence efficiency and luminescence dissymmetry. A study published in the journal Advanced Optical Materials tested whether highly luminescent racemic carbon-centered gold(I)-silver(I) clusters could be converted into bright CPL emitters by enantioresolution with chiral donor ligands.

Researchers have shown that treating highly luminescent but racemic carbon-centered gold(I)-silver(I) clusters with chiral oxygen-donor ligands can separate them into mirror-image forms (enantiomers) that retain strong photoluminescence while gaining the ability to emit circularly polarized light.

A phosphate-protected enantiomer pair achieved a photoluminescence quantum yield of 0.92÷0.93 and the largest luminescence dissymmetry factor (|glum | = 0.008) among the clusters tested. Incorporating the cluster into a composite device with a cholesteric liquid crystal raised the measured device-level |glum | to 1.25.

Rotating light pattern reveals laser frequency in a single image

An international team of physicists has developed a new method for determining the precise color of laser light using an image that rotates as the laser’s frequency shifts.

The finding could offer a new way to ensure that lasers are ‘locked’ to the frequencies needed by technologies that rely on them, from GPS positioning to quantum sensors. It could also spur developments in spectroscopy, magnetometry and quantum communications.

In a new paper published in the journal Optica, the University of Glasgow-led team describes how it devised a way to determine the frequency of a laser beam in a single snapshot.

Revisiting a Young Isaac Newton

Isaac Newton is typically portrayed as a solitary scientist with intense focus who was obsessed with power and deeply egotistical. But a new book by Caltech historians Jed Buchwald and Mordechai Feingold takes a deeper look at Newton’s life in the two decades leading up to the 1687 publication of his groundbreaking text, Principia Mathematica, when he was 44. Using newly digitized scans of Newton’s early writings, Buchwald and Feingold uncover a portrait of the young polymath as a curious and social scholar whose interests were often fleeting.

How the moon and sun may trigger slow earthquakes on Earth

While not quite a fatal attraction, the gravitational pull of the moon and sun creates tiny stresses on Earth that can trigger events known as slow earthquakes. These are movements along fault lines (fault slips) that release their energy gradually over much longer periods than ordinary quakes. Although they have been observed, exactly how these celestial bodies trigger them has been a relatively tough nut to crack.

So a team of geoscientists led by Yishuo Zhou at PSL University in Paris created computer models of these fault lines to find out what is going on.

Overlooked lakes may be helping to keep the Northern Hemisphere cool

Lakes may cover only a small fraction of Earth’s surface, but new research suggests they play a bigger role in regulating the planet’s climate than previously recognized. By reflecting sunlight back into space when covered in snow and ice, lakes in the Northern Hemisphere have a stronger cooling effect than the surrounding land.

Dr. Sarah Cooley of Duke University and colleagues say their results highlight an overlooked part of Earth’s climate system that could be better represented in climate models, which scientists use to understand how the planet responds to changing environmental conditions.

How bumblebees keep up with a flower that won’t stay still

Landing on a moving target is a challenge for all flying animals. For bumblebees, a flower swaying in the wind creates an erratic landing pad. Reaching it means matching its sideways motion while continuing to face it. When the bee turns in flight, its view of the flower changes, which complicates the feat.

In a new study, researchers Chenyao Wang and colleagues at Wageningen University and Delft University of Technology placed a circular, flowerlike platform at a hive entrance, where bumblebees learned to land to return home. During the experiments, the flower model moved sideways through two complete cycles per second, traveling 2.5 centimeters (1 inch) to either side of its central position.

Three high-speed cameras captured 48 landing sequences. The team reconstructed the flights in three dimensions to separate two actions that happened together: moving sideways to follow the platform and turning to face it.

New device measures curved mirrors’ absolute shape to within 2 nanometers without touching them

Researchers at AIST have developed a device that measures the absolute surface profile of curved optical elements with high precision without touching them.

High-precision curved mirrors are used for light collection and wavefront control in extreme ultraviolet (EUV) lithography systems, synchrotron facilities, astronomical telescopes, gravitational wave detectors and more. The accuracy of their surface profiles significantly affects the performance of these devices.

During manufacturing, it is crucial to determine not only fine-scale surface topography but also the absolute surface profile, including information such as the radius of curvature. These measurements are then used to correct the surface profile. However, measuring the surface profile of curved mirrors with accuracy on the order of a few nanometers without damaging the surface has been difficult.

AI structure prediction speeds discovery of ‘molecular glues’ to treat disease

A Baylor College of Medicine-led team has developed a strategy that combines the analysis of thousands of proteins with artificial intelligence to accelerate the discovery of small molecules called molecular glues to treat disease. Their approach, published in Nature Communications, has uncovered a new class of molecular glues that could neutralize harmful proteins linked to blood cancers and autoimmune diseases. The work also shows how AI-based structural modeling can help chemists optimize compounds well before experiments reveal how they work.

“Many scientists are increasingly exploring a new way to treat disease: Instead of blocking harmful proteins, they aim to eliminate them entirely. One promising approach uses molecular glues, which act like matchmakers inside cells,” said senior and co-corresponding author Dr. Jin Wang, director of the Center for NextGen Therapeutics and Michael E. DeBakey, M.D., endowed professor in pharmacology and in the Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology at Baylor. Wang also is a member of Baylor’s Dan L Duncan Comprehensive Cancer Center.

“These compounds bring a target protein to the cell’s natural protein-disposal machinery, which destroys the target. In this study, our team discovered and optimized a new class of molecular glues that selectively remove a protein called VAV1, an important regulator of immune cell function that has been linked to blood cancers and autoimmune diseases,” Wang said.

/* */