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Category: engineering – Page 164

Turning diamond into metal

Circa 2020 o,.o.

Long known as the hardest of all natural materials, diamonds are also exceptional thermal conductors and electrical insulators. Now, researchers have discovered a way to tweak tiny needles of diamond in a controlled way to transform their electronic properties, dialing them from insulating, through semiconducting, all the way to highly conductive, or metallic. This can be induced dynamically and reversed at will, with no degradation of the diamond material.

The research, though still at an early proof-of-concept stage, may open up a wide array of potential applications, including new kinds of broadband solar cells, highly efficient LEDs and power electronics, and new optical devices or quantum sensors, the researchers say.

Their findings, which are based on simulations, calculations, and previous experimental results, are reported this week in the Proceedings of the National Academy of Sciences. The paper is by MIT Professor Ju Li and graduate student Zhe Shi; Principal Research Scientist Ming Dao; Professor Subra Suresh, who is president of Nanyang Technological University in Singapore as well as former dean of engineering and Vannevar Bush Professor Emeritus at MIT; and Evgenii Tsymbalov and Alexander Shapeev at the Skolkovo Institute of Science and Technology in Moscow.

3 astronauts selected for upcoming Shenzhou-12 space station mission, poised for flight, outside cabin tasks: Yang Liwei

The three astronauts who will take the Shenzhou-12 manned spacecraft to China’s Tianhe space station core cabin in June are now under Level-2 quarantine, with all related work having entered a final sprint stage, Yang Liwei, director of the China Manned Space Engineering Office and the country’s first astronaut revealed.

Yang, who went into space in the Shenzhou-5 craft on October 15, 2003, made the remarks during an interview with state broadcaster China Central Television (CCTV) on Saturday, following the successful launch of the Tianzhou-2 cargo craft earlier in the day.

According to Yang, the three astronauts of the Shenzhou-12 mission, who were selected from China’s first and second batch of astronauts, will stay in space for three months, during which they will conduct tasks including repair and maintenance, appliance switch and scientific operation of payloads.

Activating Genes With a Smartwatch to Control Insulin Production

They need to speed these processes along.

Many modern fitness trackers and smartwatches feature integrated LEDs. The green light emitted, whether continuous or pulsed, penetrates the skin and can be used to measure the wearer’s heart rate during physical activity or while at rest.

These watches have become extremely popular. A team of ETH researchers now wants to capitalize on that popularity by using the LEDs to control genes and change the behavior of cells through the skin. The team is led by Martin Fussenegger from the Department of Biosystems Science and Engineering in Basel. He explains the challenge to this undertaking: “No naturally occurring molecular system in human cells responds to green light, so we had to build something new.”

Green light from the smartwatch activates the gene

The ETH professor and his colleagues ultimately developed a molecular switch that, once implanted, can be activated by the green light of a smartwatch.

Generating electricity from heat using a spin Seebeck device

Thermoelectric (TE) conversion offers carbon-free power generation from geothermal, waste, body or solar heat, and shows promise to be the next-generation energy conversion technology. At the core of such TE conversion, there lies an all solid-state thermoelectric device which enables energy conversion without the emission of noise, vibrations, or pollutants. To this, a POSTECH research team proposed a way to design the next-generation thermoelectric device that exhibits remarkably simple manufacturing process and structure compared to the conventional ones, while displaying improved energy conversion efficiency using the spin Seebeck effect (SSE).

A POSTECH joint research team—led by Professor Hyungyu Jin and Ph.D. candidate Min Young Kim of the Department of Mechanical Engineering with Professor Si-Young Choi of the Department of Materials Science and Engineering—has succeeded in designing a highly efficient thermoelectric device by optimizing the properties of both the interior and surface of the magnetic material that makes up the SSE thermoelectric device. This is a pioneering study to show the possibility of fabricating a next-generation thermoelectric device by utilizing the SSE, which has remained in . These research findings were recently published in the online edition of Energy and Environmental Science, an international academic journal in the field of energy.

Conventional TE devices rely on the charge Seebeck effect, a thermoelectric effect wherein a charge current is generated in the direction parallel to an applied temperature gradient in a solid material. This longitudinal geometry complicates the device structure and limits manufacturing such TE devices.

SpaceX Starlink: how it could kickstart an ‘uncontrolled experiment’

In a paper for Nature this month, researchers claim the development of mega-constellations like Starlink “risks multiple tragedies of the commons, including tragedies to ground-based astronomy, Earth orbit, and Earth’s upper atmosphere.”

Perhaps the biggest effects could come as the satellites start to deorbit, sparking what could be a major experiment in geoengineering.

This week’s SpaceX launch is the 29th batch of Starlink satellites since the first in May 2019, building out the firm’s internet connectivity constellation. Starlink aims to offer high-speed and low latency internet access almost anywhere with a view of a ground terminal.

SpaceX has now launched 1737 satellites for Starlink, with 951 operational. Starlink satellites typically take a few months to move into position and start operations. Starlink is already the biggest single constellation in space, but the firm has applied for permission to launch up to 42000 satellites.

Groundbreaking Research Optimizes Body’s Own Immune System to Fight Cancer

First-of-its-kind study shows how engineered immune cells move faster to attack the tumor.

A groundbreaking study led by engineering and medical researchers at the University of Minnesota Twin Cities shows how engineered immune cells used in new cancer therapies can overcome physical barriers to allow a patient’s own immune system to fight tumors. The research could improve cancer therapies in the future for millions of people worldwide.

The research is published in Nature Communications, a peer-reviewed, open access, scientific journal published by Nature Research.

Could blocking the sun save the planet?

As the need for urgent climate solutions grows, scientists want to put more research into a technology known as solar geoengineering — the idea of chemically altering the atmosphere to reflect sunlight away from Earth.

It is seen as a potential method of cooling the planet and offsetting climate change. But could such a technology curtail a climate catastrophe — or become the cause of it?

Those against solar geoengineering fear unintended consequences, including irreversible changes to weather patterns, and many climate activists are wary of using the Earth’s atmosphere as a testing ground. Last month in Sweden, an experiment led by Harvard University researchers was cancelled following opposition by environmental and indigenous groups. Researchers had planned on testing a high-altitude balloon that could be used to disperse reflective aerosol particles into the atmosphere.

In this episode of The Stream, we’ll learn more about solar geoengineering and the debate surrounding it.

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Researchers develop advanced model to improve safety of next-generation reactors

When one of the largest modern earthquakes struck Japan on March 11, 2011, the nuclear reactors at Fukushima-Daiichi automatically shut down, as designed. The emergency systems, which would have helped maintain the necessary cooling of the core, were destroyed by the subsequent tsunami. Because the reactor could no longer cool itself, the core overheated, resulting in a severe nuclear meltdown, the likes of which haven’t been seen since the Chernobyl disaster in 1986.

Since then, reactors have improved exponentially in terms of safety, sustainability and efficiency. Unlike the light-water reactors at Fukushima, which had liquid coolant and , the current generation of reactors has a variety of coolant options, including molten-salt mixtures, supercritical water and even gases like helium.

Dr. Jean Ragusa and Dr. Mauricio Eduardo Tano Retamales from the Department of Nuclear Engineering at Texas A&M University have been studying a new fourth-generation , -bed reactors. Pebble-bed reactors use spherical fuel elements (known as pebbles) and a fluid coolant (usually a gas).

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