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New nanomaterial resists projectile impact better than Kevlar

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Nanoarchitected Impact Resistant Material


Engineers at the Massachusetts Institute of Technology, California Institute of Technology and Zurich’s Higher Institute of Technology believe that “nanoarchitectural” materials developed from precisely patterned nanoscale structures (pictured) could be a promising way to create lightweight armor, protective coatings, blast shields and other impact-resistant materials. … Credit: Courtesy of the researchers

The new material is thinner than a human hair and is capable of absorbing the impact of microparticles moving at supersonic speed.

California Institute of Technology Engineers, Massachusetts Institute of Technology, and ETH Zürich have developed a nanoarchitectural material made of tiny carbon struts that, pound for pound, is more effective at stopping a projectile than Kevlar, a material commonly used in personal protective equipment.

Designed by Caltech materials specialist Julia R. Greer, nanoarchitectural materials have structures designed at the nanometer scale and exhibit unusual, often surprising properties – for example, an extremely lightweight ceramic that returns to its original sponge-like shape upon compression.

“The knowledge gained from this work can provide design principles for ultra-lightweight impact-resistant materials for use in effective armor materials, protective coatings and explosion-proof shields desired in defense and space applications,” said Greer, Ruben F. and Donna Mettler. Professor of Materials Science, Mechanics and Medical Engineering, whose laboratory led the production of the material. Greer is a co-author of an article on the new material published in Materials of Nature

Supersonic microparticles of nanomaterial stability

The team tested the stability of the material by firing microparticles at it at supersonic speeds and found that a material thinner than a human hair prevents miniature projectiles from piercing through it. Credit: Courtesy of the researchers

The material, which is thinner than a human hair, is composed of interconnected tetrakaidecahedrons made from carbon rods formed at very high temperatures (called pyrolytic carbon). Tetrakaidecahedrons are structures with 14 faces: six with four sides and eight with eight sides. They are also called “Kelvin cells” because in 1887 Lord Kelvin (physicist William Thomson, first Baron Kelvin, after whom we quote absolute temperatures in “Kelvin” units) suggested that they would be the best form for filling empty space. three-dimensional space with objects of the same size using a minimum surface area.

“Historically, this geometry is evident in energy efficient foams,” says Carlos Portela (MS ’16, PhD ’19), Assistant Professor in Mechanical Engineering at MIT and Lead / Corresponding Author Materials of Nature paper. Portela and his laboratory investigated the use of foam-like structures to give flexibility to hard coal. “While carbon is usually fragile, the location and small dimensions of the spacers in the nanoarchitectural material create a rubbery architecture with a predominance of flex,” he says.

While the strength of nanoarchitectural materials was studied using slow deformation (such as compression and tension), Portela wanted to know how such a material could withstand high-speed impact.

Impact of microparticles on nanoarchited material

Impact of microparticles on MIT nanoarchitectural material

Using a high-speed camera, the researchers filmed a video of microparticles affecting nanoarchitectural material. Photo: Massachusetts Institute of Technology / Courtesy of the researchers.

As a postdoctoral fellow at the California Institute of Technology in Greer’s lab, Portela first fabricated a light-sensitive polymer material using two-photon lithography, a technique that uses a fast, powerful laser to solidify and model microscopic structures. Then his team pyrolyzed the structures; that is, they burned them in an oven at a very high temperature to convert the polymer to pyrolytic carbon. Scientists have created two versions of the material: denser and looser. Portela’s lab then detonated both versions with 14 micron spherical silica particles one at a time. The particles moved at a speed of 40 to 1100 meters per second; for reference, the speed of sound is 340 meters per second.

The researchers found that the denser version of the material was more elastic, and the microparticles tended to embed themselves in the material rather than tear it through, as would be the case with fully dense polymers or carbon sheets of the same thickness. On closer inspection, they found that the individual struts immediately surrounding the particle could collapse, but the overall structure remained intact until the projectile stopped. Pound for pound, the new material outperformed steel by more than 100 percent and Kevlar composites by more than 70 percent.

“We show that a material can absorb a lot of energy due to this mechanism of shock compaction of the struts at the nanoscale, compared to something completely dense and monolithic rather than nanoarchitecture,” says Portela.

In order for the material to be used in real-world applications, researchers will need to find ways to scale it up and study how other nanoarchitectural materials, including those made from materials other than carbon, withstand high-speed testing. blows. Meanwhile, the study has demonstrated the viability of nanoarchitecture materials in terms of impact resistance, opening up a new avenue of research.

Read more about this study. Stronger than Kevlar and steel: ultra-lightweight material withstands ultrasonic microparticles

Reference: “Supersonic Impact Resistance of Nanoarchitectural Carbon” by Carlos M. Portel, Bryce W. Edwards, David Weisset, Juchen Sun, Keith A. Nelson, Dennis M. Cochmann and Julia R. Greer, June 24, 2021. Materials of Nature
DOI: 10.1038 / s41563-021-01033-z

Coauthors: former Caltech PhD student Bryce Edwards; David Weisset, Yuchen Sun, and Keith A. Nelson of the Institute of Soldiers Nanotechnology and the Department of Chemistry, MIT; and Dennis M. Cochmann of ETH Zürich. This research was supported in part by the Office of Naval Research, the Vannevar Bush Faculty Fellowship, and the US Army Research Office through the MIT Institute for Soldier Nanotechnology.





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Anti-vaccinators use Instagram Stories and link stickers to spread misinformation

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Anti-vaccinators use Instagram Stories and link stickers to spread misinformation


How do anti-vaccinators fund their dangerous movement with so many online platforms that ban false information against vaccinations?

According to a new report, Instagram Stories is one of the main outlets Media issues.

The report found “dozens of examples of users” who have armed Facebook’s Stories feature to sell products, promote events and even redirect Instagram users to alternative social media platforms, where they can’t be banned.

This is a special feature that the Media Matters report focuses on.link stickers”it spread to all users of Instagram late last year.

Link stickers allow users to add a link to a third party website to the Stories content. For years, Instagram has avoided allowing off-platform links, except for one link that allows users to add to their profile page. Link stickers eventually gave users this feature, as well as gave antivaxers a way to profit from their accounts.

On Instagram Terms of serviceThe platform will remove the ability to publish account stickers if they “repeatedly share things like hate speech and misinformation or other content that violates our Community Rules”.

However, because Instagram events are ephemeral, they disappear after 24 hours, and antivaxists, conspiracy theorists, and malicious users can spread malicious misinformation and links to their followers.

In addition, some anti-vaccinators who use these methods on Instagram are using backup accounts, which can only be temporary. Suspension, removal of features, or other penalties for violating Instagram policies may work with most bona fide users, but antivaxers do not work in good faith. Many are using the accounts created to avoid the ban, disseminate misinformation against vaccinations through Instagram Stories, and link the stickers as quickly as possible until the last Instagram account is closed.

Instagram has been battling antivaxes on its platform for many years. The company has taken some measures against misinformation about the vaccine, such as banning hashtags related to antivax, good nose even the COVID-19 pandemic. Still, Instagram continues to provide the most productive stuff anti-vaxxer agents in motion with the platform. The Instagram Stories and link stickers feature provides a lifeline for these users, even though Instagram has banned their main accounts.

The stories and link stickers used to spread misinformation about the vaccine are another example of how antivaxers use all the tools at their disposal to tell the story they want to tell, despite the truth.

UPDATE: January 27, 2022, 3:00 p.m. EST An Instagram spokeswoman told Mashable that the company had taken action against two prominent anti-waxes on its platform: Joseph Mercola and Sherry Tenpenny, both of whom were named in the Media Matters report. The full Instagram post is below: “We do not allow people to share posts or links that block vaccines or share incorrect information about COVID-19. We removed @ drtpenny_official for violating our rules, removed two posts from @ drmercola and hacked the #plandemic hash.”





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Thanks for attending the 2022 Mobile World Congress

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(Source: Honorary)

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Chinese smartphone maker Honor Announced on Thursday, February 28, 2022 that it will again participate in the Mobile World Congress.

As the most influential exhibition in the field of mobile communications in the world, the 2022 Mobile World Congress (MWC2022) will be held from February 28 to March 3 in Barcelona, ​​Spain. A number of other major Chinese smartphone companies, including Huawei and XiaomiOnePlus, realme and OPPO have all confirmed their presence.

In addition, the Honor product launch is scheduled for February 28. According to the posters, new products from its Magic series will be released and internet users will think that it will be the Honor Magic4 series.

Previous models in this series include: Magic3, Magic3 Pro, Magic3 Pro + and Magic V. The Magic3 series is equipped with a Snapdragon 888 Plus processor, a multi-camera with a ring and an 89 ° hyper-surface screen.

The Honor Magic V is the company’s first foldable-screen smartphone equipped with a Qualcomm Snapdragon 8 Gen 1, priced at 9,999 yuan ($ 1,571).

SEE ALSO: Honor Magic V: The first foldable smartphone to be equipped with the Snapdragon 8 Gen 1



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Zhipu Technologies finances A and A + rounds

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(Source: Zhipu Technologies)

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Recently reported by Zhipu Technologies it secured several hundred million yuan in Round A and Round A + financing agreements. Round A was invested only by Chengwei Capital, while Round A was led by GL Ventures and then occupied by Chengwei Capital. These two rounds of funding will be used for future product research and market development in the spectrum industry.

Founded in 2018, Zhipu Technologies is a company focused on spectral vision. The company relies on state-of-the-art intelligent spectral imaging equipment and spectral vision analysis systems to help end users overcome previously impossible obstacles.

Today, the company’s spectral imaging products and services are successfully implemented in safety production and environmental protection, involving dozens of large enterprises and large parks. The team led the development of an industrial application standard issued by the China Chemical Safety Association and helped establish an early warning spectral video measurement and control mechanism.

The company’s founding team is from Nanjing University and Tsinghua University. Cao Xun, the company’s founder, has dedicated himself to computer photography for many years, and the first theoretical achievements of the PMVIS spectral video have been published in the most influential journals and conferences in the country and abroad.

SEE: WITINMEM chip company completes $ 32 million round B1 financing

Zhang Jian, the company’s founder and current CEO, said the company has also made progress in miniature spectral camera technology with the idea of ​​laying the foundations for consumer-class production, research, education, medical health and public safety.



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