World's most heat resistant material found

December 25, 2016

London, Dec 25: Scientists have identified materials that can withstand temperatures of nearly 4,000 degrees Celsius, an advance that may pave the way for improved heat resistant shielding for the faster-than-ever hypersonic space vehicles.heat

Researchers from Imperial College London in the UK discovered that the melting point of hafnium carbide is the highest ever recorded for a material.

Tantalum carbide (TaC) and hafnium carbide (HfC) are refractory ceramics, meaning they are extraordinarily resistant to heat. Their ability to withstand extremely harsh environments means that refractory ceramics could be used in thermal protection systems on high-speed vehicles and as fuel cladding in the super-heated environments of nuclear reactors.

However, there has not been the technology available to test the melting point of TaC and HfC in the lab to determine how truly extreme an environment they could function in. The researchers developed a new extreme heating technique using lasers to test the heat tolerance of TaC and HfC.

They used the laser-heating techniques to find the point at which TaC and HfC melted, both separately and as mixed compositions of both.

They found that the mixed compound (Ta0.8Hf0.20C) was consistent with previous research, melting at 3,905 degrees Celsius, but the two compounds on their own exceeded previous recorded melting points. The compound TaC melted at 3,768 degrees Celsius, and HfC melted at 3,958 degrees Celsius.

The findings may pave the way for the next generation of hypersonic vehicles, meaning spacecraft could become faster than ever.

"The friction involved when travelling above Mach 5 -hypersonic speeds - creates very high temperatures," said Omar Cedillos-Barraza, currently an Associate Professor at the University of Texas.

"So far, TaC and HfC have not been potential candidates for hypersonic aircraft, but our new findings show that they can withstand even more heat than we previously thought - more than any other compound known to man," said Cedillos-Barraza, who carried out the research as a PhD student at Imperial College London

"This means that they could be useful materials for new types of spacecraft that can fly through the atmosphere like a plane, before reaching hypersonic speeds to shoot out into space," he said.

"These materials may enable spacecraft to withstand the extreme heat generated from leaving and re-entering the atmosphere," he added.

Examples of potential uses for TaC and HfC could be in nose caps for spacecraft, and as the edges of external instruments that have to withstand the most friction during flight.

Currently, vehicles going over Mach 5 speeds do not carry people, but Cedillos-Barraza suggests it may be possible in
the future.

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Agencies
June 27,2020

Mumbai, Jun 27: The Bombay High Court observed that COVID-19 patients from poor and indigent sections cannot be expected to produce documentary proof to avail subsidised or free treatment while getting admitted to hospitals.

The court on Friday was hearing a plea filed by seven residents of a slum rehabilitation building in Bandra, who had been charged ₹ 12.5 lakh by K J Somaiya Hospital for COVID-19 treatment between April 11 and April 28.

The bench of Justices Ramesh Dhanuka and Madhav Jamdar directed the hospital to deposit ₹10 lakh in the court.

The petitioners had borrowed money and managed to pay ₹10 lakh out of ₹12.5 lakh that the hospital had demanded, after threatening to halt their discharge if they failed to clear the bill, counsel Vivek Shukla informed the court.

According to the plea, the petitioners were also overcharged for PPE kits and unused services.

On June 13, the court had directed the state charity commissioner to probe if the hospital had reserved 20% beds for poor and indigent patients and provided free or subsidised treatment to them.

Last week, the joint charity commissioner had informed the court that although the hospital had reserved such beds, it had treated only three poor or indigent persons since the lockdown.

It was unfathomable that the hospital that claimed to have reserved 90 beds for poor and indigent patients had treated only three such persons during the pandemic, advocate Shukla said.

He further argued that COVID-19 patients, who are in distress, cannot be expected to produce income certificate and such documents as proof.

However, senior advocate Janak Dwarkadas, who represented the hospital, said the petitioners did not belong to economically weak or indigent categories and had not produced documents to prove the same.

A person who is suffering from a disease like COVID-19 cannot be expected to produce certificates from a tehsildar or social welfare officer before seeking admission in the hospital, the bench noted and asked the hospital to deposit ₹10 lakh in court within two weeks.

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Agencies
April 17,2020

New Delhi, Apr 17: The Indian Railways turned 167 years old on Thursday and for the first time ever, its trains did not carry any passengers on its birthday and instead stood idle in the yards waiting for the nationwide lockdown to end.

On this day 167 years ago, the wheels of the first passenger train in the country from Mumbai to Thane started rolling.

In 1974, Indians experienced life without trains for the first time. In May 1974 during the strike of the railways that lasted for around three weeks, drivers, station masters, guards, track staff and many others went on 'chakka jam' demanding fixed working hours for train drivers and an across-the-board pay hike.

"I can recall those times vividly. I remember that our leader George Fernandes had almost secured a deal with the then railway minister, but it fell through when it was taken to the then Prime Minister Indira Gandhi," All India Railwaymens Federation General Secretary Shiv Gopal Mishra, who was an apprentice in the railways at that time, told PTI.

"Fernandes was arrested in Lucknow. The workers went through a lot at that time. But those were days that angry workers had refused to give in and took great risks to get their demands met," he said.

However, just like this time, four decades ago too freight trains carrying essential supplies were run and the unions agreed to let some passenger trains run on the trunk routes like the Kalka Mail from Howrah to Delhi.

"Never ever in its history, there has been such a long interruption of services. Not during the World Wars, not during the 1974 railway strike, or any other national calamity or natural disaster," a railway spokesperson said.

The first Indian Railways passenger train was flagged off on April 16, 1853, from Mumbai to nearby Thane.

On Thursday, the Railway Ministry wished the railways a happy birthday on Twitter - "Today, 167 years ago with the zeal of 'never to stop' the wheels of the first passenger train from Mumbai to Thane started rolling. For the first time, passenger services are stopped for your safety. Stay indoors & make the nation victorious," it said.

Railway has suspended all passenger services since March 25 till May 3 due to the coronavirus outbreak. Around 15,523 trains run by the railways have been affected including 9,000 passenger trains and 3,000 mail express services which are run daily. It caters to over 20 million passengers every day.

According to the Union health ministry, the death toll due to coronavirus rose to 414 and the number of cases to 12,380 in the country on Thursday.

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Agencies
June 5,2020

With the scrapping of Mitron and Remove China Apps from its Play Store gaining a lot of attention in India, Google on Thursday said that it removed a video app "for a number of technical policy violations", while adding that it also does not allow an app that "encourages or incentivizes users into removing or disabling third-party apps".

Both the apps became immensely popular in India within a short span of time due to the prevailing anti-China sentiment amid border tensions between India and China in Ladakh and calls by Indian activists to boycott Chinese products.

Reports suggested that the Mitron app is a repackaged version of TicTic, which is a TikTok clone.

The Remove China Apps was designed to help users identify applications of Chinese origin.

Without naming the apps, Google hinted that the Mitron app may make a comeback on the Play Store once it fixes some technical issues, but the chances of the Remove China Apps are thin.

"We have an established process of working with developers to help them fix issues and resubmit their apps. We've given this developer (of the video app) some guidance and once they've addressed the issue the app can go back up on Play," Sameer Samat, Vice President, Android and Google Play, said in a statement.

Google said that its Android app store was designed to provide a safe and secure experience for the consumers while also giving developers the platform and tools they need to build sustainable businesses.

Samat said that Google Play recently suspended a number of apps for violating the policy that it does not allow an app that "encourages or incentivizes users into removing or disabling third-party apps or modifying device settings or features unless it is part of a verifiable security service".

"This is a longstanding rule designed to ensure a healthy, competitive environment where developers can succeed based upon design and innovation. When apps are allowed to specifically target other apps, it can lead to behaviour that we believe is not in the best interest of our community of developers and consumers," Samat said.

"We've enforced this policy against other apps in many countries consistently in the past - just as we did here," he added.

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