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Archive for the ‘materials’ category: Page 194

Aug 26, 2020

Vanadium-base alloys for fusion reactor applications — a review☆

Posted by in categories: materials, nuclear energy

Vanadium could be used for outer hulls of spaceships to absorb sun like energy or higher.

Vanadium-base alloys offer potentially significant advantages over other candidate alloys as a structural material for fusion reactor first wall/blanket applications. Although the data base is more limited than that for the other leading candidate structural materials, viz., austenitic and ferritic steels, vanadium-base alloys exhibit several properties that make them particularly attractive for the fusion reactor environment. This paper presents a review of the structural material requirements, a summary of the materials data base for selected vanadium-base alloys with emphasis on the V-15Cr-5Ti alloy, and a comparison of projected performance characteristics compared to other candidate alloys. Also, critical research and development (R&D) needs are defined.

The relatively high thermal conductivity and low thermal expansion coefficient of vanadium-base alloys, which result in lower thermal stresses for a given heat flux compared to most other candidate alloys, should enhance the reactor wall-load and lifetime capability. Since the mechanical strength of vanadium-base alloys is retained at relatively high temperatures, higher operating temperatures are projected for these alloys than for austenitic or ferritic steels. The refractory metals, including vanadium, characteristically exhibit good corrosion resistance in purified liquid metals. The vanadium alloys also exhibit favorable neutronic properties which include lower parasitic neutron absorption leading to better tritium breeding performance, lower bulk nuclear heating rates, and lower helium generation rates compared to the steels.

Aug 26, 2020

A thermal invisibility cloak actively redirects heat

Posted by in categories: biotech/medical, materials

Light, sound, and now, heat — just as optical invisibility cloaks can bend and diffract light to shield an object from sight, and specially fabricated acoustic metamaterials can hide an object from sound waves, a recently developed thermal cloak can render an object thermally invisible by actively redirecting incident heat.

The system, designed by by scientists at the Nanyang Technological University (NTU) in Singapore, has the potential to fine-tune temperature distribution and heat flow in electronic and semiconductor systems. It has application in devices with high requirements for efficient dissipation and homogenous thermal expansion, such as high-power engines, magnetic resonance imaging (MRI) instruments, and thermal sensors.

“Because of its shape flexibility, the active thermal cloak might also be applied in human garments for effective cooling and warming, which makes a lot of sense in tropical areas such as Singapore,” said Prof. Baile Zhang of NTU.

Aug 23, 2020

Loofah-inspired aerogel efficiently filters microbes from water

Posted by in categories: biotech/medical, materials

Millions of people worldwide die every year from waterborne diseases because of a lack of affordable, practical disinfection technologies. To address this need, researchers have developed a strong, flexible filter out of a silica aerogel that efficiently kills bacteria, resists getting clogged, and needs just a quick dip in dilute bleach to renew its disinfecting properties.

Read about the loofah-inspired aerogel here: https://bit.ly/3lhulJo


Low-cost, functionalized silica material kills bacteria instantly and is easy to clean.

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Aug 23, 2020

NASA’s New $10 Billion Telescope to Study Quasars and Their Host Galaxies in Three Dimensions

Posted by in categories: cosmology, materials

Supermassive black holes, which likely reside at the centers of virtually all galaxies, are unimaginably dense, compact regions of space from which nothing — not even light — can escape. As such a black hole, weighing in at millions or billions of times the mass of the Sun, devours material, it is surrounded by a swirling disk of gas. When gas from this disk falls towards the black hole, it releases a tremendous amount of energy. This energy creates a brilliant and powerful galactic core called a quasar, whose light can greatly outshine its host galaxy.

Astronomers widely believe that the energy from quasars is responsible for limiting the growth of massive galaxies. Shortly after the launch of NASA ’s James Webb Space Telescope, scientists plan to study the effect of three carefully selected quasars on their host galaxies in a program called Q3D.

Continue reading “NASA’s New $10 Billion Telescope to Study Quasars and Their Host Galaxies in Three Dimensions” »

Aug 22, 2020

The Biggest Frog that Ever Lived

Posted by in categories: climatology, materials

Untangling the origins of Beelzebufo — the giant frog that lived alongside the dinosaurs — turns out to be one of the most bedeviling problems in the history of amphibians.

Thank you to these paleoartists for allowing us to use their wonderful illustrations:
Ceri Thomas: http://alphynix.tumblr.com/
Nobu Tamura: https://spinops.blogspot.com/
Julio Lacerda: https://252mya.com/gallery/julio-lacerda

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Aug 21, 2020

‘DiceKeys’ Creates a Master Password for Life With One Roll

Posted by in category: materials

A new kit leaves your cryptographic destiny up to 25 cubes in a plastic box.

Aug 21, 2020

You Could Win $25K Worth of 3D Printing Services

Posted by in categories: 3D printing, materials

A start-up based in Berkeley, California, polySpectra, is attempting to make better materials for 3D printing. Their inaugural material, COR Alpha, promises to be a stronger and more durable material for digital light processing (DLP) printing. If it’s a compelling fit for your project, you could win $25,000 worth of 3D printing services from polySpectra.

In an attempt to spur the development of 3D printed projects with COR Alpha, polySpectra is holding the Make It Real 3D Printing Challenge. The challenge calls for submissions of designs that could benefit from the new material. The winner will receive $25,000 worth of polySpectra’s 3D printing services in the form of mentoring, design consultation, functional prototyping, qualification, testing and fabrication. Applications are due September 28.

Aug 20, 2020

Scientists create water filtration membranes that can clean themselves

Posted by in categories: food, materials

Scientists at the Department of Energy’s (DOE) Argonne National Laboratory have developed a light-activated coating for filtration membranes—the kind used in water treatment facilities, at semiconductor manufacturing sites and within the food and beverage industry—to make them self-cleaning, eliminating the need to shut systems down in order to repair them.

Cheap and effective, have been around for years but have always been vulnerable to clogging from organic and that stop up its pores over time, a phenomenon known as fouling.

“Anything you stick in water is going to become fouled sooner or later,” said Argonne senior scientist Seth Darling.

Aug 20, 2020

A new kind of plastic that is able to maintain its original qualities when recycled

Posted by in category: materials

A team of researchers from the U.S., China, and Saudi Arabia has developed a new kind of plastic that is able to maintain its original qualities when recycled. In their paper published in the journal Science Advances, the group describes how the new plastic is made and how well it did when tested for recyclability.

For many years, plastics have been seen as a highly desirable modern advancement—they are light, strong, bendable when needed, and can be used in a very wide variety of applications. The down side to plastics, of course, is that they do not recycle very well and they take a very long time to decay. This has led to millions of tons of plastic waste winding up in landfills and in the water table. Because of that, scientists have been hard a work looking for a new kind of plastic that has all the advantages of the old plastic but also can be easily recycled. In this new effort, the researchers claim to have developed just such a plastic.

The researchers made the new plastic by preparing a bridged bicyclic thiolactone from a bio-based olefin carboxylic acid. The result was a plastic (they called PBTL) that had all the qualities of traditional plastics. They next tested their plastic by conducting bulk depolymerization at 100°C using a catalyst. Testing of the result showed the PBTL had been broken down into its original monomer. They followed that up by breaking down samples of PBTL (using a catalyst) at room temperature. And once again, close examination showed the sample had been broken down to the original monomer.

Aug 20, 2020

Kepler’s supernova remnant: Debris from stellar explosion not slowed after 400 years

Posted by in categories: cosmology, materials

Astronomers have used NASA’s Chandra X-ray Observatory to record material blasting away from the site of an exploded star at speeds faster than 20 million miles per hour. This is about 25,000 times faster than the speed of sound on Earth.

Kepler’s supernova remnant is the debris from a detonated star that is located about 20,000 light years away from Earth in our Milky Way galaxy. In 1604 early astronomers, including Johannes Kepler who became the object’s namesake, saw the supernova explosion that destroyed the star.

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