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A clearer view of what makes glass rigid – EurekAlert

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IMAGE: A team of scientists led by the University of Tokyo uses computer simulations to study the rigidity of amorphous solids like glass
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Credit: Institute of Industrial Science, the University of Tokyo

Tokyo, Japan – Researchers led by The University of Tokyo employed a new computer model to simulate the networks of force-carrying particles that give amorphous solids their strength even though they lack long range order. This work may lead to new advances in high-strength glass, which can be used for cooking, industrial, and smartphone applications.

Amorphous solids such as glass–despite being brittle and having constituent particles that do not form ordered lattices–can possess surprising strength and rigidity. This is even more unexpected because amorphous systems also suffer from large anharmonic fluctuations. The secret is an internal network of force-bearing particles that span the entire solid which lends strength to the system. This branching, dynamic network acts like a skeleton that prevents the material from yielding to stress even though it makes up only a small fraction of the total particles. However, this network only forms after a “percolation transition” when the number of force-bearing particles exceeds a critical threshold. As the density of these particles increases, the probability that a percolating network that goes from one end to the other increases from zero to almost certain.

Now, scientists from the Institute of Industrial Science at The University of Tokyo have used computer simulations to carefully show the formation of these percolating networks as an amorphous material is cooled below its glass transition temperature. In these calculations, binary particle mixtures were modelled with finite-range repulsive potentials. The team found that the strength of amorphous materials is an emergent property caused by the self-organization of the disordered mechanical architecture.

“At zero temperature, a jammed system will show long-range correlations in stress due to its internal percolating network. This simulation showed that the same is true for glass even before it has completely cooled,” first author Hua Tong says.

The force-bearing backbone can be identified by recognizing that particles in this network are must be connected by at least two strong force bonds. Upon cooling, the number of force-bearing particles increases, until a system-spanning network links together.

“Our findings may open up a way towards a better understanding of amorphous solids from a mechanical perspective,” senior author Hajime Tanaka says. Since rigid, durable glass is highly prized for smartphones, tablets, and cookware, the work can find many practical uses.

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The work is published in Nature Communications as “Emergent solidity of amorphous materials as a consequence of mechanical self-organisation” (DOI: 10.1038/s41467-020-18663-7).

About Institute of Industrial Science (IIS), the University of Tokyo

Institute of Industrial Science (IIS), the University of Tokyo is one of the largest university-attached research institutes in Japan.

More than 120 research laboratories, each headed by a faculty member, comprise IIS, with more than 1,000 members including approximately 300 staff and 700 students actively engaged in education and research. Our activities cover almost all the areas of engineering disciplines. Since its foundation in 1949, IIS has worked to bridge the huge gaps that exist between academic disciplines and real-world applications.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

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Ultimate absentee ballot: US astronaut votes from space station – Phys.org

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Credit: Pixabay/CC0 Public Domain

At least she didn’t have to wait in line.

A US astronaut cast her ballot from the International Space Station on Thursday, making her voice heard in the despite being 253 miles (408 kilometers) above the Earth.

“From the International Space Station: I voted today,” crew member Kate Rubins, who began a six-month stint aboard the orbiting station last week, said on US space agency NASA’s Twitter account.

The post featured a photograph of Rubins, her blonde hair floating in the zero-gravity environment, in front of a white enclosure with a paper sign that reads “ISS voting booth.”

Rubins and NASA described the process as a form of absentee voting.

A secure electronic ballot generated by a clerk’s office in Harris County, home of NASA’s Johnson Space Center in Houston, Texas, was sent up via email to the ISS.

Rubins filled out the ballot in the email and it was downlinked and delivered back to the clerk’s office.

She is no stranger to the process: Rubins cast her vote from the ISS during the 2016 election. Congress passed legislation in 1997 that made voting from space possible.

“We consider it an honor to be able to vote from space,” she said in a video before she and two Russian cosmonauts launched from the Russian-operated Baikonur cosmodrome in Kazakhstan on October 14.

“If we can do it from space then I believe folks can do it from the ground too.”

Three other American astronauts were also expected to vote from space but their October 31 trip to the ISS was delayed.


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NASA astronaut casts lone vote from space


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Ultimate absentee ballot: US astronaut votes from space station (2020, October 23)
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OSIRIS-REx collects sample from Bennu asteroid after 2-year orbit – KOKI FOX 23

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“Even though we have some work ahead of us to determine the outcome of the event — the successful contact, the TAGSAM gas firing, and back-away from Bennu are major accomplishments for the team. I look forward to analyzing the data to determine the mass of sample collected,” Dante Lauretta said in a statement, according to CNN. Lauretta is the principal investigator for the mission and is a professor at the University of Arizona Lunar and Planetary Laboratory.

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Space: Astronauts uncovered a leak at the space station ISS with a tea bag – three are back on earth – Pledge Times

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Spacemen of the International Space Station ISS have shown ingenuity. The astronauts made use of a tea bag in space. Three of them have now returned to earth.

  • Russia and the USA share the International space station ISS.
  • However, there is one at the station about 400 kilometers above the earth leak.
  • The crew tried to fix the air leak using a Tea bags to detect.

Update from October 22nd, 4:40 p.m. Three of the astronauts who boarded the International Space Station (ISS) with help of a Tea bags one leak have found (see first report), have returned to Earth safely after almost 200 days on the ISS. The US astronaut Chris Cassidy and the Russian cosmonauts Anatoly Ivanishin and Ivan Wagner landed on Thursday in the Kazakh steppe, as photos by the Russian space agency Roskosmos show.

The three spacemen were in April ISS broken up. Because of the Corona pandemic Wagner, Iwanischin and Cassidy had to be in quarantine a good month before the start of their six-month mission. At that time they could not personally say goodbye to their families. It was the third mission on board the ISS for Cassidy and Ivanishin. Wagner, on the other hand, made his first flight to the space station. In a tweet before his return to earth, the 35-year-old wrote: “Mom, I’m coming home.”

First report from October 19, 2020: Space: Leak found at space station ISS – household goods are the solution

Moscow – spaceman the International Space Station have a possible Air leak with help of a Tea bags tracked down. This had flown in weightlessness in the direction of the leak, said cosmonaut Anatoly Ivanishin according to the state agency Tass. “We have several photos and videos of the direction of flight of the teabag.” He reckons with “actually having found the probable leak”. It should start with a duct tape be sealed.

The space travelers have been occupied with the leak in the station about 400 kilometers above the earth for weeks. They had to spend a weekend in the Russian segment in August because they were looking for the hole in another part of the station. According to earlier information from the Russian space agency Roscosmos the leak is “extremely insignificant” and harmless to the astronauts and cosmonauts.

Space station ISS: “Air pressure continues to drop”

“Of the Air pressure continues to fall, but not as quickly, ”said Ivanishin. The crew now wants to better seal the crack and keep an eye on the situation. “Perhaps we should use the more effective patches from our partners,” said the Russian spaceman, referring to his American colleagues.

A short time later that is Oxygen system Elektron-WM failed according to Roscosmos. A spokesman for Roskosmos confirmed, however, that there is no danger for the crew, as the oxygen system in the US segment of the ISS continues to function normally.

ISS: Russian aerospace veteran: “All modules in the Russian segment are worn out”

Currently hold up six spacemen in the ISS. The crew had only last week Reinforcement got after a Soyuz capsule with three spacemen on board after a flight in Record time has docked with the ISS. So far, there have been three space travelers on the ISS, who were also under strict conditions in the spring corona-Pads started. They are supposed to return to earth in October.

It wasn’t until April Oxygen leak found in the ISS, which is more than two decades old. The Russian aerospace veteran Gennadi Padalka told the Ria-Novosti news agency that the station’s Russian equipment had long exceeded its shelf life: “All modules in the Russian segment are worn“Said the cosmonaut who holds the record for the most days spent in space. The equipment was actually only designed for a service life of 15 years. (ck / dpa)

Most recently, an asteroid named “Bennu” was on a dangerous course towards Earth in space. Even a ninth planet in our solar system is said to have been discovered.

List of rubric lists: © Nasa / dpa

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