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Archive for the ‘materials’ category: Page 75

Nov 6, 2023

Nonsteady Illumination Improves Imaging Resolution

Posted by in category: materials

Illuminating a high-resolution lens with waves whose intensity diminishes over time can improve the image quality.

Images formed using a conventional lens have a strict resolution limit—features smaller than about one half of a wavelength of light are lost. “Superlenses” made from structures called metamaterials could potentially beat this restriction if not for unavoidable losses in the transmission of the light carrying the finest details. Now researchers have used sound waves to demonstrate a new way around this problem that should also apply to light waves: they varied the amplitude of the “illuminating” waves over time [1]. The new approach, they believe, will enable the development of more precise acoustic and photonic lenses for use in areas such as microscopy and ultrasound imaging.

Not all of the light that reflects off of an object escapes to distances far away. The so-called evanescent waves decay rapidly in amplitude as they travel away from an object, but these waves contain the subwavelength information required to beat the usual resolution limit. A technique called near-field scanning optical microscopy can detect these waves by using a probe to scan across the object at close range, but real-time images are not possible because the scanning process is time consuming. Other “superresolution” imaging techniques also face trade-offs between complexity, speed, and efficiency.

Nov 6, 2023

New research shows quasars can be buried in their host galaxies

Posted by in categories: cosmology, materials

A new study reveals that supermassive black holes at the centers of galaxies, known as quasars, can sometimes be obscured by dense clouds of gas and dust in their host galaxies.

This challenges the prevailing idea that quasars are only obscured by donut-shaped rings of dust in the close vicinity of the black hole.

Quasars are extremely bright objects powered by gorging on surrounding material. Their powerful radiation can be blocked if thick clouds come between us and the quasar.

Nov 5, 2023

AI companies have all kinds of arguments against paying for copyrighted content

Posted by in categories: materials, robotics/AI

The biggest companies in AI aren’t interested in paying to use copyrighted material as training data, and here are their reasons why.

The US Copyright Office is taking public comment on potential new rules around generative AI’s use of copyrighted materials, and the biggest AI companies in the world had plenty to say. We’ve collected the arguments from Meta, Google, Microsoft, Adobe, Hugging Face, StabilityAI, and Anthropic below, as well as a response from Apple that focused on copyrighting AI-written code.

There are some differences in their approaches, but the overall message for most is the same: They don’t think they should have to pay to train AI models on copyrighted work.

Continue reading “AI companies have all kinds of arguments against paying for copyrighted content” »

Nov 5, 2023

New microchip material is 10 times stronger than Kevlar

Posted by in categories: computing, materials

The new material is highly scalable especially compared to other alternatives such as graphene and diamonds.

Researchers at Delft University of Technology have created a novel material that has a yield strength ten times higher than Kevlar, rivaling the strength of other super strong alternatives such as graphene and diamonds.

High-strength synthetic fibers like Kevlar are renowned for their remarkable resilience to abrasion and wear. They are most notably used in applications that are reinforcing and strengthening, particularly in body armor, helmets, and other protective gear.

Nov 2, 2023

Solving a long-standing problem in transmission electron microscopy

Posted by in category: materials

For researchers wanting to understand the inner workings of magnetic materials, transmission electron microscopy is an indispensable tool. Because the wavelength of an electron is much shorter than the wavelength of visible light, a beam of electrons transmitted through a thin slice of a material can create an image in which the inner structure of the material is magnified up to 50 million times, many orders of magnitude more than with an optical microscope.

Since transmission electron microscopy, or TEM, was first developed in the 1930s, scientists and engineers have come up with many variations on the technique. Each of these variations suit different applications and come with their own advantages and disadvantages.

Now, researchers at NTNU have come up with a remarkably simple method to solve a long-standing problem in an almost 30-year-old TEM-based technique known as scanning precession electron diffraction, or SPED.

Nov 2, 2023

Strange magnetic material could make computing energy-efficient

Posted by in categories: computing, materials

A research collaboration co-led by EPFL has uncovered a surprising magnetic property of an exotic material that might lead to computers that need less than one-millionth of the energy required to switch a single bit.

The world of materials science is constantly discovering or fabricating materials with exotic properties. Among them are the multiferroics, a unique class of materials that can be both magnetized and polarized at the same time, which means that they are sensitive to both magnetic and electric fields.

Having both these properties in a single material has made multiferroics very interesting for research and commercial purposes with potential applications from advanced electronics to next-generation memory storage. By understanding and harnessing the properties of multiferroics, researchers aim to develop more efficient, compact, and even energy-saving technologies.

Nov 2, 2023

Simulating spins, spirals and shrinking devices for new classes of energy-efficient materials

Posted by in categories: materials, particle physics

The diamond in an engagement ring, the wonder-material graphene and the lead in a humble pencil are all formed from carbon, but display profoundly different characteristics. Carbon materials such as these are among the most famous examples of how diverse properties can emerge in materials, based only on the rearrangement of the structure of atoms.

The goal of the RIKEN Center for Emergent Matter Science (CEMS) in Saitama, Japan, is to develop materials for new, energy-efficient technologies. The usual approach to synthesizing new materials involves looking for improved properties such as strength and durability, or enhanced conduction of electricity and heat.

But CEMS is pioneering an alternative approach that turns that standard approach on its head. First, we think of the properties needed for a new device, use data from RIKEN’s new repository and simulation platform to calculate the atomic structure that provides these features and then build the bespoke material.

Nov 2, 2023

Study reveals the origin of high superconducting critical temperatures in trilayer cuprates

Posted by in category: materials

High-temperature cuprate superconductors are a broad class of materials that exhibit some unique characteristics. Due to their distinctive properties, these materials exhibit the highest superconducting temperatures reported to date under ambient pressure.

Researchers at the Chinese Academy of Sciences and other institutes in China recently carried out a study aimed at better understanding the processes underpinning the high superconducting critical temperatures (Tc) observed in trilayer cuprates, a class of materials with three layers based on compounds containing copper. Their paper, published in Nature Physics, unveiled the electronic origin of the high Tc exhibited by these three-layered materials.

“Our group has been trying to understand the high temperature superconductivity mechanism in for many years,” Xingjiang Zhou, one of the researchers who carried out the study, told Phys.org.

Nov 1, 2023

Engineers Develop Efficient Process To Make Fuel From Carbon Dioxide

Posted by in categories: materials, sustainability

The search is on worldwide to find ways to extract carbon dioxide from the air or from power plant exhaust and then make it into something useful. One of the more promising ideas is to make it into a stable fuel that can replace fossil fuels in some applications. But most such conversion processes have had problems with low carbon efficiency, or they produce fuels that can be hard to handle, toxic, or flammable.

Now, researchers at MIT and Harvard University have developed an efficient process that can convert carbon dioxide into formate, a liquid or solid material that can be used like hydrogen or methanol to power a fuel cell and generate electricity. Potassium or sodium formate, already produced at industrial scales and commonly used as a de-icer for roads and sidewalks, is nontoxic, nonflammable, easy to store and transport, and can remain stable in ordinary steel tanks to be used months, or even years, after its production.

Oct 28, 2023

China allegedly cracks hypersonic thermal barrier, bringing heat on US

Posted by in categories: materials, transportation

The newly developed material resisted temperatures up to 7,343 degrees Fahrenheit without melting or losing shape during tests when applied to encase the surface of a waverider aircraft.

China’s scientists have claimed a major breakthrough: a successful test of a new surface material for hypersonic jets, which was considered impossible to make earlier.

The development means that the Asian powerhouse has surpassed far ahead of the United States in the hypersonic race, according to a report by the South China Morning Post (SCMP) on Monday.

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