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Mar 14, 2022

Using pump lasers to create plasma lenses that focus at very high intensity levels

Posted by in categories: nuclear energy, particle physics

A team of researchers from Lawrence Livermore National Laboratory, the University of California at Berkeley and Princeton University has developed plasma-based techniques to build a lens for laser beams with petawatt-scale power. In their paper published in the journal Physical Review Letters, the group describes the two techniques they developed.

Physicists conducting work with and fusion research efforts are hopeful that other researchers will build lasers that are more powerful than those currently available. Such work has been held up by the solid-state optics technology used to create lasers—giving them more power would damage the parts used to generate the laser, making them useless. In this new effort, the researchers noted that other researchers have found that plasma can be used to create optic components such as amplifiers and mirrors. They wondered if the same might be true for the kind of lens needed to produce extremely powerful laser beams. They came up with a concept that involved inducing patterns of high and in a given plasma. Light moving through it, they note, would experience a based on the density of the plasma.

The researchers did not actually build such a laser, but instead, proposed two ways that it might be built. The first method involved firing two pump lasers at a gas sample. The first laser ionized the gas into a plasma, while the second did not. The result was a plasma with a bulls-eye configuration of high and low-density plasma rings, which could be used as a laser lens.

Mar 14, 2022

Scientists fabricate novel electrical component to improve stability of solar cells

Posted by in categories: internet, nanotechnology, solar power, sustainability

In the future, decarbonized societies that use internet of things (IoT) devices will become commonplace. But to achieve this, we need to first realize highly efficient and stable sources of renewable energy. Solar cells are considered a promising option, but their electrical contacts suffer from a “tradeoff” relationship between surface passivation and conductivity. Recently, researchers from Japan have developed a new type of electrical contact that can overcome this problem.

The most recent type of commercial photovoltaic cell (solar cell) uses stacked layers of crystalline silicon (c-Si) and an ultrathin layer of silicon oxide (SiOx) to form an electrical contact. The SiOx is used as a “passivating” film—an unreactive layer that improves the performance, reliability, and stability of the device. But that does not mean that simply increasing the thickness of this passivating layer will lead to improved . SiOx is an electrical insulator and there is a trade-off relationship between passivation and the conductivity of the electrical contact in solar cells.

In a new study, published in ACS Applied Nano Materials, a research team led by Assistant Professor Kazuhiro Gotoh and Professor Noritaka Usami from Nagoya University has developed a novel SiOx layer that simultaneously allows high passivation and improved conductivity. Named NAnocrystalling Transport path in Ultrathin dielectrics for REinforcing passivating contact (NATURE contact), the new electrical contact consists of three-layer structures made up of a layer of silicon nanoparticles sandwiched between two layers of oxygen-rich SiOx. “You can think of a passivating film as a big wall with gates in it. In the NATURE contact, the big wall is the SiOx layer and the gates are Si nanocrystals,” explains Dr. Gotoh.

Mar 13, 2022

Inflation Rises 7.9%, Hitting 40-Year High for Food, Rent and Gas Prices. What’s Next?

Posted by in category: food

The Fed is expected to raise interest rates as early as next week to counteract rocketing inflation.

Mar 13, 2022

Tokamak Energy achieves record-breaking plasma temperature of 100M degrees

Posted by in categories: government, nuclear energy

If nuclear fusion reaction – the process that powers the Sun and other stars – could be used on a consistent basis on Earth, it would be a source of virtually unlimited clean energy. But there are still a lot of obstacles to overcome.

U.K.-based nuclear fusion firm Tokamak Energy has demonstrated a world-first with its privately-funded ST40 spherical tokamak, achieving a plasma temperature of 100 million degrees Celsius. This threshold is necessary for the future deployment of commercially successful fusion power. According to the company, this is by far the highest temperature ever achieved in a spherical tokamak and by any privately funded tokamak.

Several government laboratories have reported plasma temperatures above 100 million degrees in conventional tokamaks, including South Korea’s KSTAR reactor and China’s “artificial sun” EAST tokamak reactor. However, Tokamak Energy highlights that its milestone has been achieved in just five years, or a cost of less than £50m ($70m), in a much more compact fusion device. This achievement further substantiates spherical tokamaks as the optimal route to the delivery of clean, secure, low-cost, scalable, and globally deployable commercial fusion energy.

Mar 13, 2022

Astrolab FLEX Rover enables crew transport, last-mile cargo delivery

Posted by in category: robotics/AI

The multi-use rover can autonomously swap payloads, mobilize astronauts, and more.

Mar 13, 2022

Neurons Are Fickle. Electric Fields Are More Reliable for Information

Posted by in category: neuroscience

Summary: Electric fields may represent information held in working memory, allowing the brain to overcome representational drift.

Source: MIT

A new study suggests that electric fields may represent information held in working memory, allowing the brain to overcome “representational drift,” or the inconsistent participation of individual neurons.

Mar 13, 2022

Russia has requested military and economic assistance from China, US officials say

Posted by in categories: drones, economics, military

Russia has asked China for military support, including drones, as well as economic assistance for its unprovoked invasion of Ukraine, according to conversations CNN had with two US officials.

The requests came after Russia’s invasion of Ukraine, one of the officials said. That official declined to detail the Chinese reaction but indicated that the Chinese had responded.

Potential assistance from the Chinese would be a significant development in Russia’s invasion. It could upend the hold Ukrainian forces still have in the country as well as provide a counterweight to the harsh sanctions imposed on Russia’s economy.

Mar 13, 2022

China’s Yutu-2 lunar rover sends image from ‘dark side’ of the moon

Posted by in category: space travel

China’s lunar rover has beamed back a new image of the ‘dark side’ of the moon showing the winding path it has taken over the surface.

The Yutu-2 rover arrived on the moon three years ago on Change’e 4 — the first spacecraft to ever land on the far side of the moon.

Continue reading “China’s Yutu-2 lunar rover sends image from ‘dark side’ of the moon” »

Mar 13, 2022

Open-Access Dataset of Macaque Brain Published

Posted by in categories: education, neuroscience

Researchers have released a new open-access data set recorded from the visual cortex of macaque monkeys during rest state.


Summary: Researchers have released a new open-access data set recorded from the visual cortex of macaque monkeys during resting state.

Source: KNAW

Continue reading “Open-Access Dataset of Macaque Brain Published” »

Mar 13, 2022

Microsoft Improves Transformer Stability to Successfully Scale Extremely Deep Models to 1000 Layers

Posted by in category: robotics/AI

A Microsoft Research team has introduced a “simple yet effective” method that dramatically improves stability in transformer models with just a few lines of code change.

Large-scale transformers have achieved state-of-the-art performance on a wide range of natural language processing (NLP) tasks, and in recent years have also demonstrated their impressive few-shot and zero-shot learning capabilities, making them a popular architectural choice for machine learning researchers. However, despite soaring parameter counts that now reach billions and even trillions, the layer depth of transformers remains restricted by problems with training instability.

In their new paper DeepNet: Scaling Transformers to 1,000 Layers, the Microsoft team proposes DeepNorm, a novel normalization function that improves the stability of transformers to enable scaling that is an order of magnitude deeper (more than 1,000 layers) than previous deep transformers.