New solar cell may be most efficient in the world

July 13, 2017

Washington, Jul 13: Scientists have designed a new solar cell that converts direct sunlight to electricity with 44.5 per cent efficiency, and may potentially be the most efficient solar cell in the world.solar

The prototype integrates multiple cells stacked into a single device capable of capturing nearly all of the energy in the solar spectrum, researchers said.

The approach developed by researchers at George Washington University (GWU) in the US is different from the solar panels one might commonly see on rooftops or in fields.

The new device uses concentrator photovoltaic (CPV) panels that employ lenses to concentrate sunlight onto tiny, micro-scale solar cells.

Due to their small size - less than one millimetre square - solar cells utilising more sophisticated materials can be developed cost effectively, researchers said.

The stacked cell acts almost like a sieve for sunlight, with the specialised materials in each layer absorbing the energy of a specific set of wavelengths.

By the time the light is funnelled through the stack, just under half of the available energy has been converted into electricity. By comparison, the most common solar cell today converts only a quarter of the available energy into electricity.

"Around 99 per cent of the power contained in direct sunlight reaching the surface of Earth falls between wavelengths of 250 nanometres (nm) and 2,500 nm, but conventional materials for high-efficiency multi-junction solar cells cannot capture this entire spectral range," said Matthew Lumb, lead author of the study published in the journal Advanced Energy Materials.

"Our new device is able to unlock the energy stored in the long-wavelength photons, which are lost in conventional solar cells, and therefore provides a pathway to realising the ultimate multi-junction solar cell," said Lumb.

While scientists have worked towards more efficient solar cells for years, this approach has two novel aspects.

First, it uses a family of materials based on gallium antimonide (GaSb) substrates, which are usually found in applications for infra-red lasers and photodetectors. The novel GaSb-based solar cells are assembled into a stacked structure along with high efficiency solar cells grown on conventional substrates that capture shorter wavelength solar photons.

In addition, the stacking procedure uses a technique known as transfer-printing, which enables three dimensional assembly of these tiny devices with a high degree of precision.

This particular solar cell is very expensive, however researchers believe it was important to show the upper limit of what is possible in terms of efficiency.

Despite the current costs of the materials involved, the technique used to create the cells shows much promise, researchers said.

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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
July 24,2020

Pune, Jul 24: Agile and dexterous, 85-year-old Shantabai Pawar wields sticks with absolute ease as she displays 'lathi-kathi' on the streets of Pune.

A video of her, displaying her skills in the Indian martial art form for livelihood, has gone viral on social media.

Pawar told media persons that she learnt the art form when she was only eight and has been practising it since then. The ancient martial art s believed to be linked to Dombari community, a nomadic tribe in Maharashtra.

"I have been pursuing the art of lathi-kathi since I was eight. I have never left it. It is part of me and it is an honour to practice it. My father taught me this. He taught me to work hard," Pawar told media persons.

In the video, the sari-clad octogenarian takes a warrior-like stride and effortlessly rotates a stick several times in a second in her hand and around her head and then does it with two sticks together with a smile on her face. She also tosses a stick in the air and catches it with ease.

The assembled gathering is impressed and enthused.

"People come and say, 'Well done Daadi!' I practice it to earn money for my children and grandchildren," she said.

Pawar leaves her home in the morning in the conditions created by coronavirus and performs the art form on roads and streets.

"I go to various areas to perform the art form and people give money," she said.

The artiste also uses thali and stick to gather the attention of people as most of them are indoors due to conditions created by COVID-19.

Senior citizens have been advised against venturing out due to their greater susceptibility to coronavirus but Pawar said she is not afraid to step out.

"People do advise me to not go out due to fear of COVID-19 but I am not scared. Whenever I step out, I pray to my God and he has kept me safe so far," she said.

Aishwarya Kale, a dancer and the person who uploaded the video on social media, said that it is "only an artist who can understand what help another artist needs".

"I was in that area shopping for some items and it was then I saw her performing and thought that I should film her and upload her video on social media. But I never thought that the video would go viral and she would receive financial help not just from people in the country but overseas as well," Kale told media persons.

"She is now getting honour for her craft that she couldn't get in the last 85 years. I feel good that through my small video, her art form has become viral," she added. 

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Agencies
March 7,2020

New Delhi, Mar 7: The Union government has issued a Global Invite for Expression of Interest for disinvestment in Bharat Petroleum Corporation Limited (BPCL) from prospective bidders with a minimum net worth of $10 billion as of Saturday.

The EoI submissions can be made till May 2, whereas investor queries will be entertained till April 4.

Another condition pertains to a maximum of four members are permitted in a consortium, and the lead member must hold 40 per cent in proportion. Other members of the consortium must have a minimum $1 billion net worth.

The EOI allows changes in the consortium within 45 days, though the lead member cannot be changed.

The GoI proposes to disinvest its entire shareholding in BPCL comprising 1,14,91,83,592 equity shares held through the Ministry of Petroleum and Natural Gas, which constitutes 52.98 per cent of BPCL's equity share capital, along with the transfer of management control to the strategic buyer (except BPCL's equity shareholding of 61.65 per cent in Numaligarh Refinery Limited (NRL) and management control thereon).

The shareholding of BPCL in NRL will be transferred to a Central Public Sector Enterprise operating in the oil and gas sector under the Ministry and accordingly is not a part of the proposed transaction.

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