Archive for the ‘materials’ category

Dec 7, 2019

Atomic-level imaging could offer roadmap to metals with new properties

Posted by in category: materials

High-entropy alloys, which are made from nearly equal parts of several primary metals, could hold great potential for creating materials with superior mechanical properties.

But with a practically unlimited number of possible combinations, one challenge for metallurgists is figuring out where to focus their research efforts in a vast, unexplored world of metallic mixtures.

A team of researchers at the Georgia Institute of Technology has developed a new process that could help guide such efforts. Their approach involves building an atomic resolution chemical map to help gain new insights into individual and help characterize their properties.

Dec 7, 2019

California could use advanced desalination plants to be entirely self-sufficient even cleaning molecules of plastic also other toxins magnonics would be used to separate the molecules cell

Posted by in categories: materials, sustainability

California’s drought is spawning a slew of proposed desalination plants to create potable water from seawater, including one coming up in Santa Barbara. Just how clean are these facilities and what is their impact on ocean life?

Dec 2, 2019

Isotonic Regression is THE Coolest Machine-Learning Model You Might Not Have Heard Of

Posted by in categories: materials, robotics/AI

The term “Isotonic” originates from the Greek root words “iso” and “tonos.” The root “iso” isn’t just a file format, it actually means equal. “Tonos,” on the other hand, means to stretch. The word Isotonic can mean a multitude of things stretching from material and physical sciences to liberal arts.

Equal Stretch Regression (Isotonic Regression) is a really cool model for statistical inference. My obsession with isotonic regression has long been expanding, because the model is just so interesting, and cool.

Dec 1, 2019

SOFIA Reveals What May Be Keeping Milky Way’s Black Hole Quiet

Posted by in categories: cosmology, materials

Supermassive black holes exist at the center of most galaxies, and our Milky Way is no exception. But many other galaxies have highly active black holes, meaning a lot of material is falling into them, emitting high-energy radiation in this “feeding” process. The Milky Way’s central black hole, on the other hand, is relatively quiet. New observations from NASA’s Stratospheric Observatory for Infrared Astronomy, SOFIA, are helping scientists understand the differences between active and quiet black holes.

Dec 1, 2019

Armored with plastic ‘hair’ and silica, new perovskite nanocrystals show more durability

Posted by in categories: computing, materials

Perovskite nanocrystals hold promise for improving a wide variety of optoelectronic devices—from lasers to light emitting diodes (LEDs) — but problems with their durability still limit the material’s broad commercial use.

Researchers at the Georgia Institute of Technology have demonstrated a novel approach aimed at addressing the material’s durability problem: encasing the inside a double-layer protection system made from plastic and silica.

In a study published Nov. 29 in the journal Science Advances, the research team describes a multistep process to produce encased perovskite that exhibit strong resistance to degradation in moist environments.

Dec 1, 2019

Physicists Have Identified a Metal That Conducts Electricity But Not Heat

Posted by in categories: materials, physics

Researchers have identified a metal that conducts electricity without conducting heat — an incredibly useful property that defies our current understanding of how conductors work.

The metal, found in 2017, contradicts something called the Wiedemann-Franz Law, which basically states that good conductors of electricity will also be proportionally good conductors of heat, which is why things like motors and appliances get so hot when you use them regularly.

But a team in the US showed this isn’t the case for metallic vanadium dioxide (VO2) — a material that’s already well known for its strange ability to switch from a see-through insulator to a conductive metal at the temperature of 67 degrees Celsius (152 degrees Fahrenheit).

Nov 29, 2019

Ecology for Insiders

Posted by in category: materials

The view from the HazeCam, which is situated just west of the Jackson Street Bridge in Newark, New Jersey, usually extends for about eight miles. To the east, the skyline of New York City rises and falls along the horizon like a bar graph, buffered by a blue haze of humidity and particulate emissions and ozone. The towers are planted into the rock of Manhattan, and the island of steel-and-concrete canyons covers 59 square kilometers and accommodates 1.5 million people. Techni…

The indoor biome covers as much as six percent of the world’s landmass—and we know almost nothing about it.

Nov 29, 2019

New study shows unique magnetic transitions in quasicrystal-like structures

Posted by in categories: materials, particle physics

O, o.

In the world of materials science, many have heard of crystals—highly ordered structures in which atoms are arranged in a tight and periodic manner (in which the atomic arrangement is repeated). But, not many people know about quasicrystals, which are unique structures with strange atomic arrangements. Like crystals, quasicrystals are also tightly arranged, but what’s different about them is the fact that they possess an unprecedented pentagonal symmetry, such that the atomic arrangement is highly ordered but not periodic.

This distinctive feature gives them , like high stability, resistance to heat, and low friction. Since their discovery only about 30 years ago, scientists globally have been trying to understand the properties of quasicrystals, in an effort to make more advancements in materials research. But, this is not easy, as quasicrystals are not prevalent in nature. Luckily, they have been able to make use of structures similar to quasicrystals, called “Tsai-type approximants.” Understanding these structures in detail could give insights into the many properties of quasicrystals. One such property is antiferromagnetism, in which are aligned in a quasiperiodic order, strikingly distinguished from conventional antiferromagnets. This property has never been observed in quasicrystals so far, but the possibility was exciting for materials scientists, as it could be a gateway to a plethora of new applications.

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Nov 27, 2019

The wind from a galaxy’s supermassive black hole helps make stars… in other galaxies

Posted by in categories: cosmology, materials

Supermassive black holes are true monsters of the Universe. From millions to even billions of times the mass of the Sun, there’s one in the very center of every big galaxy in the cosmos, and in fact each galaxy itself formed and grew along with its black hole; they affect each other profoundly. As matter falls onto the black hole it falls into an accretion disk, heats up, and emits huge amounts of energy and can also blow a fierce wind of material back into the galaxy (we call such galaxies with actively feeding supermassive black holes active galaxies). This wind can push away gas and dust that would otherwise fall onto the black hole, regulating its growth.

Under some conditions this wind can also compress the gas in the galaxy, which can increase the number of stars forming in the galaxy. But too much wind and the gas is blown right out of the galaxy. Even at some levels in between, it can heat the gas up enough that star formation is much harder. It’s like a pressure valve in the galaxy.

This is how it usually works, at least. Astronomers have found a compact group of galaxies clustered around an active galaxy, and that central galaxy’s black hole is so powerful it’s blowing a wind that’s causing star formation in the galaxies around it!

Nov 26, 2019

Using light to generate order in an exotic material

Posted by in categories: materials, physics

Physics experiment with ultrafast laser pulses produces a previously unseen phase of matter.

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