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
February 27,2020

Feb 27: With the window to submit comments on India's proposed personal data protection law closing on Tuesday, a period of anxious wait for final version of the Bill started for social media firms.

This comes even as global Internet companies have called on the government for improved transparency related to intermediary Guidelines (Amendment) Rules and allay fears about the prospect of increased surveillance and prompting a fragmentation of the Internet in India that would harm users.

As per the proposed amendments, an intermediary having over 50 lakh users in the country will have to be incorporated in India with a permanent registered office and address.

When required by lawful order, the intermediary shall, within 72 hours of communication, provide such information or assistance as asked for by any government agency or assistance concerning security of the state or cybersecurity.

This means that the government could pull down information provided by platforms such as Wikipedia, potentially hampering its functioning in India.

In the open letter to IT Minister Ravi Shankar Prasad, leading browser and software development platform like Mozilla, Microsoft-owned GitHub and Cloudflare earlier called for improved transparency by allowing the public an opportunity to see a final version of these amendments prior to their enactment.

According to a Business Insider report, Indian users may lose access to Wikipedia if the new intermediary rules for internet and social media companies are approved.

Since the rules would require the website to take down content deemed illegal by the government, it would require Wikipedia to show different content for different countries.

Anusha Alikhan, senior communications director for Wikimedia told Business Insider that the platform is built though languages and not geographies. Therefore, removing content from one country, while it is still visible to other country users may not work for the company’s model.

India is one of Wikipedia’s largest markets. Over 771 million Indian users accessed the site in just November 2019.

Also read: Explained: What is the Personal Data Protection Bill and why you should care

The Personal Data Protection Bill, 2019, which was introduced in Lok Sabha in the winter session last year, was referred to a Joint Parliamentary Committee (JPC) of both the Houses.

The government last month decided to seek views and suggestions on the Bill from individuals and associations and bodies concerned and the last date for submitting the comments was on Tuesday.

Prasad, while introducing the Personal Data Protection Bill, 2019, in the Lok Sabha on December 11, announced that the draft Bill empowers the government to ask companies including Facebook, Google and others for anonymised personal data and non-personal data.

There was a buzz when the Bill's latest version was introduced in the Lok Sabha, especially the provision seeking to allow the use of personal and non-personal data of users in some cases, especially when national security is involved.

Several legal experts red-flagged the issue and said the provision will give the government unaccounted access to personal data of users in the country.

In their submission to the JPC, several organisations also flagged that the power to collect non-personal and anonymised data by the government without notice and consent should not form part of the Bill because of issues regarding effective anonymisation and potential abuse.

"Clauses 35 and 36 of the Bill provide unbridled access to personal data to the Central Government by giving it powers to exempt its agencies from the application of the Bill on the basis of various broad worded grounds," SFLC.in, a New Delhi-based not-for-profit legal services organisation, commented.

The Software Alliance, also known as BSA, a trade group which includes tech giants such as Microsoft, IBM and Adobe, among others said that the current version of the privacy bill pose substantial challenges, including the sweeping new powers for the government to acquire non-personal data, restrictions on data transfers, and local storage requirements.

"We urge the Joint Parliamentary Committee, as it considers revisions to the Bill, to eliminate provisions concerning non-personal data from the Personal Data Protection Bill and to remove the data localisation requirements and restrictions on international data flows," said Venkatesh Krishnamoorthy, Country Manager-India, BSA.

The Personal Data Protection (PDP) Bill, 2019 draws its origins from the Justice B.N. Srikrishna Committee on data privacy, which produced a draft of legislation that was made public in 2018 ("the Srikrishna Bill").

The mandatory requirement for storing a mirror copy of all personal data in India as per Section 40 of the Srikrishna Bill has been done away with in the PDP Bill, 2019, meaning that companies like Facebook and Twitter would be able to store data of Indian users abroad if they so wish.

But the bill prohibits processing of sensitive personal data and critical personal data outside India.

What is more, what constitutes critical data has not been clearly defined.

As per the proposals, social media companies will have to modify their application as they are required to have a system in place by which a user can verify themselves.

So legal experts believe that some system to upload identification documents should be there and something like the Twitter blue tick mark should be there to identify verified accounts.

"The 2019 Bill introduces a new category of data fiduciaries called social media intermediaries ('SMIs'). SMIs are a subcategory of significant data fiduciaries ('SDFs') and will be notified by the Central government after due consultation with the DPA, or the Data Protection Authority. Clause 26(4) of the Bill defines SMIs as intermediaries who primarily or solely enable online interaction between two or more users," SFLC.in said.

"On a plain reading of the definition, online platforms like Facebook, Twitter, YouTube, TikTok, ShareChat and WhatsApp are likely to be notified as SMIs under the Bill," it added.

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Agencies
June 29,2020

New Delhi, Jun 29: Witnessing azure skies and breathable air for the last three months, Delhi on Monday recorded deterioration in its air quality, with particulate matter with diameter of 2.5 and 10 microns -- too small to be filtered out of the human body -- standing at 52 and 297 micrograms per cubic respectively.

Gufran Beig, Project Director of System of Air Quality Weather Forecasting and Research (SAFAR), said that the sudden spike in air pollution is due to a mild dust storm blowing from Rajasthan.

"Since the wind direction is changing and moist air is coming in, the air quality in Delhi will become better by tomorrow," Beig told IANS.

Central Pollution Control Board (CPCB) data showed that the overall air quality near Delhi Technical University (DTU) area stood at 326 micrograms per cubic, followed by 308 at Narela and 307 at Mundka.

Out of 36 stations, the AQI in as many as 30 stations was above 200 micrograms per cubic till 1 pm on Monday.

The System of Air Quality Weather Forecasting and Research categorises air quality in the 0-50 range as good, 51-100 as satisfactory, 101-200 as moderate, 201-300 as poor, 301-400 as very poor, and above 400 as severe.

According to SAFAR's website, "PM 10 (coarser dust particle) is the lead pollutant. AQI is likely to improve to moderate category by tomorrow, and further improvement is expected by July 1."

Researchers indicated that PM 10 and PM 2.5 will be 170 and 47 micrograms per cubic on Tuesday.

With no vehicles plying on the roads or industries shut due to the lockdown since March 25, Delhi's air quality had improved drastically.

According to a study conducted by the Indian Institute of Technology (IIT), Delhi, if the low levels of air pollution reached during the lockdown period are maintained, India's annual death toll could reduce by 6.5 lakh.

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Agencies
June 26,2020

Facebook will introduce a new notification screen on its platform that will warn users if the article they are about to share is over 90 days old, the company announced on Thursday.

“We’re starting to globally roll out a notification screen that will let people know when news articles they are about to share are more than 90 days old,” Facebook wrote in a blog post.

The social media platform had previously introduced a context button in 2018 that provides information about the sources of articles in the News Feed. Building upon that, the new feature will inform users about the timeliness of the article.

“To ensure people have the context they need to make informed decisions about what to share on Facebook, the notification screen will appear when people click the share button on articles older than 90 days, but will allow people to continue sharing if they decide an article is still relevant,” Facebook said.

The social media giant stated that timeliness is important in understanding the context of an article and curbing the spread of misinformation on the platform.

“News publishers, in particular, have expressed concerns about older stories being shared on social media as current news, which can misconstrue the state of current events. Some news publishers have already taken steps to address this on their own websites by prominently labelling older articles to prevent outdated news from being used in misleading ways,” Facebook added.

Apart from this, the platform will also be testing a similar notification screen for information related to the global Covid-19 pandemic. The notification screen will provide information about the source of the link shared in a post if the link is related to information on Covid-19. It will also direct people to its previously introduced Covid-19 information centre for “authoritative” health information, it said.

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