Archive for the ‘materials’ category

Sep 26, 2022

Japan’s Hayabusa 2 asteroid sample sheds new light on the early solar system

Posted by in categories: materials, space

Source: Wikimedia Commons.

The Hayabusa 2 spacecraft dropped a capsule containing the samples — materials dating back to the beginnings of our solar system — into Earth’s atmosphere before continuing its journey to another asteroid.

Sep 25, 2022

Terahertz light from superconducting stripes

Posted by in categories: materials, quantum physics

Why do some materials carry electrical currents without any resistance only when cooled to near absolute zero while others do so at comparatively high temperatures? This key question continues to vex scientists studying the phenomenon of superconductivity. Now a team of researchers from Andrea Cavalleri’s group at the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) in Hamburg has provided evidence that electron “stripes” in certain copper-based compounds may lead to a break in the material’s crystal symmetry, which persists even in their superconducting state. Their work has been published in PNAS.

Focusing on a range of cuprates, the team investigated the coexistence and competition of their with other quantum phases. Such interactions are believed to be crucial to the development of high-temperature superconductivity—a process which remains one of the most important unsolved problems in condensed matter physics today.

The researchers exposed several cuprate crystals, grown and characterized at Brookhaven National Labs, to ultrashort laser light pulses. They observed how the materials began to emit a particular type of terahertz (THz) light—a technique known as THz emission spectroscopy.

Sep 21, 2022

Astronomers found a new way to hunt for alien worlds

Posted by in categories: materials, space

The hunt for alien worlds is more difficult than it may seem. Without the ability to travel through the cosmos, we’re left to look through telescopes and collect data to determine whether other planets lie in wait. Now, though, astronomers say they may have figured out a way to make the search for these alien worlds much easier, and it relies on a technique that looks for debris fields.

Feng Long, a postdoctoral fellow at Harvard and the Smithsonian’s Center for Astrophysics, says she discovered a possible new technique that can make finding alien worlds much easier. Instead of relying on blindly sifting through data, Long looked for material and fields of debris at the Lagrange points. She published a paper on the technique and her findings in The Astrophysical Journal Letters.

The Lagrange points can be thought of as parking places in space. These points are notable because they act as an intersection of the different gravitational fields between celestial structures. Essentially, these points act as a middle ground between gravitational pulls. As such, the pull of gravity from all objects is equal. So, debris from developing alien worlds may congregate here, Long says.

Sep 19, 2022

The Perseverance rover is finding more and more organic matter on Mars

Posted by in categories: materials, space

NASA’s Perseverance rover is exploring a long-dry river delta on Mars, and it has seen signs that indicate that the region is full of organics – molecules containing carbon that are widely considered to be the building blocks of life.

The rover has taken measurements and samples in an area called Skinner Ridge made of layered sedimentary rocks, some of which contain materials that were most likely transported from hundreds of kilometres away by running water billions of years ago.

“With the samples we’re taking now in this more sedimentary area, we’re of course right at the heart of what we wanted to do to start with,” said NASA science lead Thomas Zurbuchen during a press conference on 15 September. The goal was to look at areas similar to those on Earth that harbour signs of ancient life, he said.

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Sep 17, 2022

Users trust AI as much as humans for flagging problematic content

Posted by in categories: materials, robotics/AI

Social media users may trust artificial intelligence (AI) as much as human editors to flag hate speech and harmful content, according to researchers at Penn State.

The researchers said that when users think about positive attributes of machines, like their accuracy and objectivity, they show more faith in AI. However, if users are reminded about the inability of machines to make subjective decisions, their trust is lower.

The findings may help developers design better AI-powered content curation systems that can handle the large amounts of information currently being generated while avoiding the perception that the material has been censored, or inaccurately classified, said S. Shyam Sundar, James P. Jimirro Professor of Media Effects in the Donald P. Bellisario College of Communications and co-director of the Media Effects Research Laboratory.

Sep 16, 2022

Microneedles: A smart approach and increasing potential for transdermal drug delivery system

Posted by in categories: biotech/medical, materials

Circa 2019 face_with_colon_three

The most widely used methods for transdermal administration of the drugs are hypodermic needles, topical creams, and transdermal patches. The effect of most of the therapeutic agents is limited due to the stratum corneum layer of the skin, which serves as a barrier for the molecules and thus only a few molecules are able to reach the site of action. A new form of delivery system called the microneedles helps to enhance the delivery of the drug through this route and overcoming the various problems associated with the conventional formulations. The primary principle involves disruption of the skin layer, thus creating micron size pathways that lead the drug directly to the epidermis or upper dermis region from where the drug can directly go into the systemic circulation without facing the barrier. This review describes the various potential and applications of the microneedles. The various types of microneedles can be fabricated like solid, dissolving, hydrogel, coated and hollow microneedles. Fabrication method selected depends on the type and material of the microneedle. This system has increased its application to many fields like oligonucleotide delivery, vaccine delivery, insulin delivery, and even in cosmetics. In recent years, many microneedle products are coming into the market. Although a lot of research needs to be done to overcome the various challenges before the microneedles can successfully launch into the market.

Sep 15, 2022

Interwoven: How charge and magnetism intertwine in kagome material

Posted by in categories: materials, particle physics

Physicists have discovered a material in which atoms are arranged in a way that so frustrates the movement of electrons that they engage in a collective dance where their electronic and magnetic natures appear to both compete and cooperate in unexpected ways.

Led by Rice University physicists, the research was published online today in Nature. In experiments at Rice, Oak Ridge National Laboratory (ORNL), SLAC National Accelerator Laboratory, Lawrence Berkeley National Laboratory (LBNL), the University of Washington (UW), Princeton University and the University of California, Berkeley, researchers studied pure iron-germanium crystals and discovered standing waves of fluid electrons appeared spontaneously within the crystals when they were cooled to a critically low temperature. Intriguingly, the arose while the material was in a , to which it had transitioned at a higher temperature.

“A charge wave typically occurs in materials that have no magnetism,” said study co-corresponding author Pengcheng Dai of Rice. “Materials that have both a charge density wave and magnetism are actually rare. Even more rare are those where the charge density wave and magnetism ‘talk’ to each other, as they appear to be doing in this case.”

Sep 15, 2022

Domain Wall Discovery Points Toward Self-Healing Circuits

Posted by in categories: electronics, materials

Atomically thin materials such as graphene have drawn attention for how electrons can race in them at exceptionally quick speeds, leading to visions of advanced new electronics. Now scientists find that similar behavior can exist within two-dimensional sheets, known as domain walls, that are embedded within unusual crystalline materials. Moreover, unlike other atomically thin sheets, domain walls can easily be created, moved, and destroyed, which may lead the way for novel circuits that can instantly transform or be repaired on command.

In the new study, researchers investigated crystalline lithium niobate ferroelectric film just 500 nanometers thick. Electric charges within materials separate into positive and negative poles, and ferroelectrics are materials in which these electric dipoles are generally oriented in the same direction. The electric dipoles in ferroelectrics are clustered in regions known as domains. These are separated by two-dimensional layers known as domain walls.

The amazing electronic properties of two-dimensional materials such as graphene and molybdenum disulfide have led researchers to hope they may allow Moore’s Law to continue once it becomes impossible to make further progress using silicon. Researchers have also investigated similarly attractive behavior in exceptionally thin electrically conducting heterointerfaces between two different insulating materials, such as lanthanum aluminate and strontium titanate.

Sep 13, 2022

Applying deep-learning AI to X-rays helps find explosives in luggage

Posted by in categories: materials, robotics/AI

A team of researchers at University College London, working with a colleague from Nylers Ltd. and another from XPCI Technology Ltd., has developed a new way to X-ray luggage to detect small amounts of explosives. In their paper published in the journal Nature Communications, the group describes modifying a traditional X-ray device and applying a deep-learning application to better detect explosive materials in luggage.

Prior research has shown that when X-rays strike materials, they produce tiny bends that vary depending on the type of material. They sought to take advantage of these bends to create a precision X-ray machine.

The researchers first added a small change to an existing X-ray machine—a box containing masks, which are sheets of metal with tiny holes in them. The masks serve to split the X-ray beam into multiple smaller beams. The researchers then used the device to scan a variety of objects containing embedded and fed the results to a deep-learning AI application. The idea was to teach the machine what the tiny bends in such materials looked like. Once the machine was trained, they used it to scan other objects with embedded explosives to see if it could identify them. The researchers found their machine to be 100% accurate under lab settings.

Sep 13, 2022

Highly reflecting mirrors from the inkjet printer

Posted by in categories: biotech/medical, materials

Dielectric mirrors, also referred to as Bragg mirrors, reflect light nearly completely. Hence, they are suited for various applications, such as camera systems and sensor systems for microscopy and medical technologies. So far, such mirrors have been produced by complex processes in expensive vacuum devices. Researchers from Karlsruhe Institute of Technology (KIT) now are the first to print Bragg mirrors of high quality with inkjet printers. This may pave the way towards the digital manufacture of customized mirrors.

Research results are published in Advanced Materials (“Fabrication of Bragg Mirrors by Multilayer Inkjet Printing”).

Bragg mirrors are produced by applying several thin layers of materials onto a carrier. The resulting optical mirror specifically reflects the light of a certain wavelength. Reflectivity of a Bragg mirror depends on the materials, the number of layers applied, and their thicknesses. So far, Bragg mirrors have been produced in expensive vacuum production facilities. KIT researchers now were the first to print them on different carriers. This largely facilitates production.

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