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Sep 23, 2024

Electric Aviation With Unlimited Range Is Getting Cheaper & Smaller

Posted by in categories: robotics/AI, transportation

For the most part, we treat electric aviation like it’s something that we’ll see in the future. I mean, batteries are expensive and heavy, and they don’t hold that much energy per unit of weight. So, compared to, say, kerosene (jet fuel), batteries take up a lot more space and weight capacity in a plane design. This means either really poor range or carrying around nothing but batteries (which isn’t very useful).

But that’s only true for the largest of planes. The smaller the plane, the easier it has been for companies to electrify or even go full electric with it it. Once you get down to unmanned planes and helicopters that carry something like a small sensor payload (cameras, etc.), you’re in a realm where all-electric aviation has been around for over a decade.

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Sep 23, 2024

Analyzing Friction in Layered Materials

Posted by in categories: materials, particle physics

Experiments reveal the factors that determine the friction between the single-atom-thick layers in van der Waals materials, which may have uses in lubrication technology.

Van der Waals (vdW) materials consist of stacked, single-atom-thick layers, and these layers can experience very low friction as they slide over one another, a property that might be exploited for lubrication. A research team has now distinguished several contributions to this low friction and has shown that effects at the edges of the sliding regions dominate [1]. Some of their experiments involved sliding a several-layer-thick flake across a surface made of a similar material containing a crack, which allowed the team to systematically control the edge length. The findings could guide efforts to engineer controllable frictional forces into such materials in micromechanical devices.

The very low friction, called superlubricity, exhibited by vdW materials has been previously shown to depend on the relative orientations of the layers. If one layer is rotated by some angle, called the twist angle, with respect to the layer below, the two layers form a “superlattice” in which the two atomic lattices fall periodically in and out of registry, like a pair of overlaid combs with slightly different spacings. This arrangement is called a Moiré pattern, and the repeating elements, or unit cells, of the superlattice are called Moiré tiles. Superlubricity arises because, in general, the contributions to the frictional force from the atoms within one Moiré tile cancel each other out: Some exert a push, while others exert a pull.

Sep 23, 2024

Disorder Induces Delocalization

Posted by in categories: particle physics, quantum physics

A Bose-Einstein condensate of cold atoms occupying a periodic lattice can flow like a superfluid. But if the atoms’ mutual repulsion is strengthened and the lattice potential deepened, the atoms can become immobilized in a state known as a Mott insulator. Now Hepeng Yao of the University of Geneva and his collaborators have examined the Mott transition of cold atoms trapped in a lattice that is quasiperiodic rather than periodic [1]. Given that quasiperiodicity and other kinds of disorder tend to trap particles, the researchers were surprised to discover that their quasiperiodic lattice sustained the superfluid state rather than weakening it.

Yao and his collaborators trapped potassium-39 atoms in a one-dimensional optical lattice formed by the standing waves of two lasers. If the ratio of the lasers’ wavelengths was a rational number, the lattice was periodic. Otherwise, the lattice was quasiperiodic. By adjusting various experimental parameters, they could control the depth of the confining potentials, the strength of the interatomic repulsion, and whether the lattice sites were fully occupied. To determine whether a given set of parameters yielded a static, insulating state or a mobile, superfluid one, they turned off the trap and observed how the atoms flew apart.

The team found that the Mott transitions for the periodic and quasiperiodic lattices were both characterized by a critical value of the interparticle repulsion, but the critical value in the quasiperiodic case was higher. Quantum Monte Carlo simulations pointed to the reason. The commensurability between the lattice period and the particle number is a key factor in pinning particles in a Mott insulator. However, the quasiperiodic lattice blurs this commensurate period, thereby destabilizing the Mott phase to the profit of the superfluid one.

Sep 23, 2024

Researchers observe an antiferromagnetic diode effect in even-layered MnBi₂Te₄

Posted by in categories: computing, particle physics

Antiferromagnets are materials in which the magnetic moments of neighboring atoms are aligned in an alternating pattern, resulting in no net macroscopic magnetism. These materials have interesting properties that could be favorable for the development of spintronic and electronic devices.

Sep 23, 2024

Scientists propose a new method to search for dark matter using LIGO

Posted by in categories: cosmology, physics

A new study published in Physical Review Letters (PRL) proposes using gravitational wave detectors like LIGO to search for scalar field dark matter.

Sep 23, 2024

Hacktivist Group Twelve Targets Russian Entities with Destructive Cyber Attacks

Posted by in categories: cybercrime/malcode, finance

Twelve hacktivist group targets Russian entities with destructive cyber attacks, using public tools for maximum damage without financial gain.

Sep 23, 2024

Critical Flaw in Microchip ASF Exposes IoT Devices to Remote Code Execution Risk

Posted by in categories: computing, internet

Severe vulnerabilities in Microchip ASF and MediaTek Wi-Fi chipsets expose IoT devices to remote code execution risks. No fix for CVE-2024–7490.

Sep 23, 2024

Discord Introduces DAVE Protocol for End-to-End Encryption in Audio and Video Calls

Posted by in category: encryption

Discord launches DAVE, a custom end-to-end encryption protocol for audio and video calls, enhancing user privacy while maintaining safety measures.

Sep 23, 2024

New PondRAT Malware Hidden in Python Packages Targets Software Developers

Posted by in category: cybercrime/malcode

North Korean hackers use poisoned Python packages from PyPI to spread PondRAT malware, targeting developers in a supply chain attack.

Sep 23, 2024

New Google Chrome feature will translate complex pages in real time

Posted by in categories: internet, robotics/AI

Google is testing a new API that uses machine learning models to offer real-time language translation for inputted text and to make it easier to translate web pages.

According to a proposal spotted by Bleeping Computer, the feature is being developed by Chrome’s built-in AI team and is aimed at exposing the web browser’s built-in translation functionality and the ability to download additional language models to translate text.

While Chrome and Edge already have built-in translation features, they can sometimes have issues translating web pages that have dynamic or complex content. For example, Chrome may not be able to translate all sections of an interactive website correctly.

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