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Archive for the ‘materials’ category: Page 103

Mar 15, 2023

JWST captures a rare star 15,000 light-years away nearing its end

Posted by in categories: cosmology, materials

Called a Wolf-Rayet, these stars expel most of their outer layers into their surroundings before exploding as supernovae.

NASA’s James Webb Space Telescope has released a phenomenal image of a supernova waiting to happen. Called a Wolf-Rayet, these stars are among the most massive, luminous, and “briefly detectable” stars known. They’re at an advanced stage of stellar evolution and expel most of their outer layers into their surroundings before exploding as supernovae.

Webb had a rare sighting of a Wolf-Rayet star in June 2022. In the latest image, the telescope shows the star, WR 124, in unprecedented detail, thanks to its infrared instruments.

Continue reading “JWST captures a rare star 15,000 light-years away nearing its end” »

Mar 15, 2023

MIT Researchers Solve Dendrites Mystery To Creating Smaller & Lighter Batteries

Posted by in categories: materials, sustainability

A breakthrough regarding dendrites made by MIT researchers may finally open the way to the building of a new type of rechargeable lithium battery that is safer, lighter, and more compact than existing models, a concept that has been pursued by labs all over the world for years.

The replacement of the liquid electrolyte between the positive and negative electrodes with a considerably thinner, lighter layer of solid ceramic material and the replacement of one electrode with solid lithium metal are the two essential components of this prospective advancement in battery technology. By making these changes, the battery’s overall size and weight would be significantly reduced, and the flammable liquid electrolytes that provide a safety risk would be eliminated. Dendrites, however, have proven to be a significant obstacle in that pursuit.

Dendrites are metal growths that can accumulate on the lithium surface, pierce through the solid electrolyte, and finally cross from one electrode to the other, shorting out the battery cell. Their name is from the Latin word for branches. There hasn’t been much advancement in the understanding of what causes these metal filaments or how to stop them from occurring, making lightweight solid-state batteries a problematic alternative.

Mar 13, 2023

Fight Back with Fungi: How Mushrooms Can Help Solve the Global Housing Crisis

Posted by in categories: habitats, materials

Far from the raging zombie fungi you see on TV, this innovative architecture collaborative is harnessing the power of mycelium to combat a housing scarcity.

Mar 13, 2023

Scientists created a superconducting material at both a temperature and pressure

Posted by in category: materials

https://youtube.com/watch?v=ryJxMYX7YEU

Hydrides are created by combining rare earth metals with hydrogen, then adding nitrogen or carbon. In recent years, they offered scientists a tantalizing “working recipe” for creating superconducting materials.

Technically speaking, rare earth metal hydrides take the form of cage-like structures called clathrates, where the rare earth metal ions serve as carrier donors and supply enough electrons to promote the dissociation of the H2 molecules. Carbon and nitrogen aid in material stabilization. The bottom line is that superconductivity can occur at lower pressures.

Continue reading “Scientists created a superconducting material at both a temperature and pressure” »

Mar 13, 2023

Designing for Data Flow

Posted by in categories: computing, materials

Processing more data in more places while minimizing its movement becomes a requirement and a challenge.

Movement and management of data inside and outside of chips is becoming a central theme for a growing number of electronic systems, and a huge challenge for all of them.

Entirely new architectures and techniques are being developed to reduce the movement of data and to accomplish more per compute cycle, and to speed the transfer of data between various components on a chip and between chips in a package. Alongside of that, new materials are being developed to increase electron mobility and to reduce resistance and capacitance.

Mar 13, 2023

Quantum Geometry — The Newest “Magic” Twist in Superconductivity

Posted by in categories: materials, quantum physics

A new mechanism that gives rise to superconductivity in a material where the speed of electrons is almost zero has been discovered by scientists at The University of Texas at Dallas and their partners at The Ohio State University. This breakthrough could pave the way for the development of novel superconductors.

The results of their study, which was recently published in the journal Nature, describe a novel approach to calculate electron speed. This study also represents the first instance where quantum geometry has been recognized as the primary contributing mechanism to superconductivity in any material.

The material the researchers studied is twisted bilayer graphene.

Mar 12, 2023

The Nobel Prize in Physics 1973

Posted by in categories: materials, physics

Was divided, one half jointly to Leo Esaki and Ivar Giaever ‘for their experimental discoveries regarding tunneling phenomena in semiconductors and superconductors, respectively’ and the other half to Brian David Josephson ‘for his theoretical predictions of the properties of a supercurrent through a tunnel barrier, in particular those phenomena which are generally known as the Josephson effects’

Mar 12, 2023

Quantum effects could help make twisted bilayer graphene a superconductor

Posted by in categories: materials, quantum physics

“Measuring tBLG devices: the cryostat insert used in the experiments. (Courtesy: J Lau)” Measuring tB.

Mar 12, 2023

New Room-Temperature Superconductor Offers Tantalizing Possibilities

Posted by in categories: energy, materials

The breakthrough could one day transform technologies that use electric energy, but it comes from a team facing doubts after a retracted paper on superconductors.

Mar 12, 2023

Muted Response to New Claim of a Room-Temperature Superconductor

Posted by in categories: chemistry, materials

Another part of that wariness arises because, to date, no one has independently reproduced Dias’ team’s results. This lack of verification was raised by Jorge Hirsch of the University of California, San Diego, in the last talk of the session in which Dias and his team spoke. Hirsch argued that those claiming to have created high-temperature superconducting hydrides suffered from “confirmation bias,” cherry-picking evidence to support their agenda. (Hirsch has been an outspoken critic of Dias’ work.) As the last question of the session, Dias asked Hirsch, “Could you also have confirmation bias?” “Maybe,” Hirsch replied.

After the session, a few attending researchers—all collaborators of Dias—spoke with Physics Magazine, telling us that they disagreed with Hirsch’s cherry-picking conclusion. One of them, Russell Hemley of the University of Illinois Chicago confirmed Pasan’s claim that they have replicated the 2020 carbonaceous sulfur hydride—as reported in an arXiv paper that the team recently posted [3].

Dias’ group still needs to more precisely characterize NLH’s chemical composition, Pasan said. The samples also appear to consist of two phases, an observation that they need to investigate. Ultimately, they plan to innovate upon this material to create a superconductor at ambient pressure and temperature conditions, a goal that Pasan said he thinks is feasible. But extraordinary claims require extraordinary evidence, and the community has much of the latter still to gather.