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 12,2020

New Delhi, Jun 12: The Supreme Court on Friday asked Solicitor General Tushar Mehta to convene a meeting of the Finance Ministry and RBI officials over the weekend to decide whether interest incurred on EMIs during the moratorium period can be charged by banks.

A bench comprising Justices Ashok Bhushan, Sanjay Kishan Kaul and M.R. Shah queried Mehta as the court was concerned since the Centre has deferred loan for three months.

"Then how can interest of these 3 months be added?" the apex bench asked. Mehta replied: "I need to sit down with the RBI officials and have a meeting."

SBI's counsel, senior advocate Mukul Rohatgi, intervened during the proceedings and said "all banks are of the view that interest cannot be waived for a six month EMI moratorium period".

"We need to discuss it with the RBI," insisted Rohatgi.

Justice Bhushan then asked Mehta to convene a meeting of the RBI and Finance Ministry officials over the weekend, and listed the matter for further hearing on June 17.

The top court, during the hearing, indicated that it was not considering a complete waiver of interest but was only concerned that postponement of interest shouldn't accrue further interest on it.

After the RBI said the waiver of interest charges on EMIs during moratorium will lead to loss of 1 per cent of the nation's GDP, the top court had earlier asked the Finance Ministry to reply, whether the interest could be waived or it would continue during the moratorium period.

The top court said these are not normal times, and it is a serious issue, as on one hand moratorium is granted and then, the interest is charged on loans during this period.

"There are two issues in this (matter). No interest during the moratorium period and no interest on interest," said Justice Bhushan. The observation from the bench came on a petition by Gajendra Sharma, in which he sought a direction to declare portion of the RBI's March 27 notification as ultra vires to the extent it charged interest on the loan amount during the moratorium period.

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Agencies
June 17,2020

In a bid to help tackle rise in domestic violence during the social distancing times in India, Twitter on Wednesday launched a dedicated search prompt to serve information and updates from authoritative sources around domestic violence.

Twitter has partnered with the Ministry of Women and Child Development the National Commission for Women in India to expand its efforts towards women.

The search prompt will be available on iOS, Android and on mobile.twitter.com in India, in both English and Hindi languages, the company said in a statement.

Data shows that since the outbreak of Covid-19, violence against women and girls has intensified in India and across the globe.

"We recognise collaboration with the public, government and NGOs is key to combating the complex issue of domestic violence. Accessing reliable information through this search prompt could be a survivor's first step towards seeking help against abuse and violence," said Mahima Kaul, Director, Public Policy, India and South Asia, Twitter.

Every time someone searches for certain keywords associated with the issue of domestic violence, a prompt will direct them to the relevant information and sources of help available on Twitter.

This is an expansion of Twitter's #ThereIsHelp prompt, which was specifically put in place for the public to find clear, credible information on critical issues.

The feature will be reviewed at regular intervals by the Twitter team to ensure that all related keywords generate the proactive search prompt, said the company.

Violence against women and girls across Asia Pacific is pervasive but at the same time widely under reported.

"In fact, in many countries in our region, the number is even greater, with as many as 2 out of 3 women in some countries reporting experiences of violence," added Melissa Alvarado, UN Women Asia Pacific Regional Manager on Ending Violence against Women.

Rekha Sharma, Chairperson, the NCW, said: "With social distancing norms in place, several women are unable to contact their regular support systems. This initiative by Twitter will provide big support to the survivors, who would otherwise be easily isolated without access to relevant information and help".

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Agencies
March 25,2020

In an unprecedented crisis despite Prime Minister Narendra Modi assuring the continuation of essential services like food and groceries, online marketplaces like Flipkart and Amazon along with delivery platforms like Bigbasket, Grofers and FreshToHomes hit a major blockade on Wednesday as local authorities shut warehouses and sent delivery boys back, even harassed them.

Millions of people across cities were left helpless at homes as essential items like fruits and vegetables, dairy and milk, meat and fish etc did not reach their doors despite placing orders well in advance. Later, the orders went dry.

While Grofers' warehouse in Faridabad was closed by the local law enforcement agencies, Bigbasket complained that the police stopped its delivery partners and "some of them were even beaten up by for no fault of theirs".

"We are not operational due to restrictions imposed by local authorities on movement of goods in spite of clear guidelines provided by central authorities to enable essential services. We are working with the authorities to be back soon,' Bigbasket tweeted.

In a statement to IANS, Bigbasket said that it will help to have better coordination between the Centre and state, and between the state and local police to "ensure that our delivery vans and bikes don't get stopped by the police. Bigbasket and bb daily are not taking new orders".

Furious people stormed the social media platforms, writing their plight to NITI Aayog CEO Amitabh Kant on Twitter.

"Sir, all e-commerce are down. Believe me I tried everything (Grofers, Bigbasket, Flipkart, Amazon, Big Bazaar), no delivery till 31st March or Server Down or No Service. Need to think how we can enable them through digital India," tweeted one user.

Kant tweeted back to Bigbasket: "They should give me specifics - State & location. I will act on it by getting in touch with concerned authorities & sorting it out. Govt guidelines exempt them. We will ensure that citizens are not impacted".

Kant also responded to Grofers: "Cold storages & Warehouses as well as delivery of all essentials goods including food, pharma thru E-Commerce are exempted under MHA order. I have spoken to CS & DGP, Haryana . They have taken immediate action to ensure that supply chains efficiently function for the citizens".

The subscription-based hyperlocal delivery startup FreshToHome sent messages to its customers, saying that despite the government declaring food delivery as essential, "we are facing hardships in continuing our operations".

"Please bear with us as we are working hard to unblock local authority hurdles," said the FreshToHome team.

Reports later surfaced that the Department for Promotion of Industry and Internal Trade (DPIIT) has initiated talks with the state Chief Secretaries asking them not to restrict movement of people engaged in home delivery of essential items, mentioned in the list of exempted items circulated by the Home Ministry.

Meanwhile, Flipkart said it has temporarily suspended its operations and services - including grocery items. The marketplace has decided to halt all orders from March 25 for all three supply chains -- groceries, non-large goods and large items.

"Flipkart has temporarily suspended orders as we assess the possibilities of operating in the lockdown. We are prioritising the safety of our delivery executives and seeking the support of the local governments and police authorities to meet the needs of our customers as they stay home during this lockdown," Rajneesh Kumar, Chief Corporate Affairs Officer, Flipkart, said in a statement.

E-commerce giant Amazon said the company has to "temporarily stop taking orders and disable shipments for lower-priority products.

"For all pending customer orders on lower-priority products, we are reaching out to customers and giving them a choice to cancel their orders, and receive a refund for prepaid items," said the company.

Witnessing a surge in demand, supermarket chain Biz Bazaar entered the fray, with launching doorstep delivery services in major cities like Delhi, Mumbai, Bengaluru and Gurugram.

However, within no time, Big Bazaar was flooded with calls, forcing the company to issue a statement, saying that "In light of the recent announcement, we are receiving an unprecedented number of requests for doorstep delivery. There could be a delay due to the restrictions on movements".

Already battling massive surge in demand, the online delivery platforms faced other issues too, including zero access to several high-rises across the country which have gone under complete lockdown with all entry and exit gates locked.

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