Why is the ozone hole concentrated over Antarctica?

Ozone is a colourless gas. Chemically, it is very active and reacts readily with a number of substances. These reactions cause rubber to crack, hurt plant life, and damage people’s lung tissues. But ozone also absorbs harmful components of sunlight, “ultraviolet B”, or “UV-B, protecting living things below.

Ozone can be destroyed by a number of free radical catalysts, the most important of which are the hydroxyl radical (OH), nitric oxide radical (NO), chlorine atom (Cl) and bromine atom (Br). Human activity has dramatically increased the levels of chlorine and bromine in the atmosphere.

Each year for the past few decades during the Southern Hemisphere spring, chemical reactions involving chlorine and bromine cause ozone in the southern polar region to be destroyed rapidly and severely. This depleted region is known as the “ozone hole”. British scientists discovered this hole in 1985.

The hole in Antarctica occurs in the spring (September to December). It begins with this overall ozone thinning, but it is assisted by the presence of polar stratospheric clouds (PS clouds). During the extreme cold of winter, with no sun for six months, polar winds create a vortex which traps and chills the air; the temperature is below -80 Celsius. The ice in these PS clouds provides surfaces for the chemical reactions that destroy the ozone. This needs light to kick-start the reactions. By the end of spring warmer December temperatures break up the vortex and destroy the PS clouds. Sunlight starts creating ozone again and the hole begins to repair.

Every March to April during the Northern Hemisphere springtime similar, but less pronounced ozone hole forms above the Arctic. The natural circulation of wind, the polar vortex, is much less developed in the Northern Hemisphere above the Arctic.

SoftBank turns largest investor in Indian e-Commerce The Japanese giant recently said that it intends to invest about $10 bn in India over the next few years

Japanese technology major SoftBank has become the largestinvestor in the Indian e-commerce segment. With its latest investment of $90 million in Housing.com, SoftBank’s overall investment in Indian e-commerce stands at about $1 billion.

In October, the company had invested $627 million in Snapdeal.com, while about $210 million was deployed into ANI Technologies’ taxi-booking service Ola Cabs. In November, Bharti SoftBank, a joint venture between Bharti Enterprises and SoftBank Corp, acquired 36.5 per cent stake in ScoopWhoop, an India-focused media start-up, for an undisclosed amount.

It is believed SoftBank owns 30 per cent stake each in Snapdeal.com and Housing.com.

Recently, the Japanese company said it aimed to invest about $10 billion in India through the next few years.

Aashish Bhinde of Avendus Capital says, “Softbank has done extraordinarily well by investing in digital businesses during the early stages of the market’s evolution, as was seen during its investment in Alibaba. Clearly, the Indian digital market is the next frontier for disproportionate value creation, which explains their bullishness on this space.”

SoftBank’s $20-million investment in Chinese e-commerce group Alibaba in 2000 is now worth $86 billion, following the Chinese company floating an initial public offering in the US. Through 10 years, Masayoshi Son, the founder of SoftBank, has increased the value of his investments from $3.3 billion to $99 billion, according to the company’s latest earnings presentation.

The Indian e-commerce market is estimated at $11 billion. It is expected to stand at $20 billion by 2015, a compounded annual growth rate (CAGR) of 37 per cent through 2013-15, according to a recent report by Motilal Oswal Securities. The e-retail segment would be the biggest growth driver (with an expected CAGR of 60 per cent), increasing from $1.7 billion in 2013 to $7 billion in 2016, it added.

Aakash Moondra, chief financial officer of Snapdeal.com, said, “The investment the e-commerce sector is witnessing is an endorsement of the global confidence in India’s growth potential. Globally, investors want to be a part of India’s large untapped growth frontier — e-commerce.”

Another large investor in this segment is Tiger Global, which has funded companies such as online travel portal MakeMyTrip and search engine Just Dial. Tiger Global also led a $1-billion round of investment in Flipkart. It has also invested in Myntra, Quikr and Hike.

Pramod Kumar, managing director, Barclays Capital India, said, “The online retailing segment in India today accounts for a mere 0.5 per cent, compared with 8-13 per cent in developed countries. The sector is expected to grow sevenfold to $30 billion by 2020 and the number of e-shoppers could grow from 20 million to about 90 million. Clearly, India is a massive e-commerce opportunity, which cannot be ignored.”

According to data from VCCedge, this year, 53 deals, worth $3.2 billion, have been recorded in the Indian e-commerce space, against 58 deals worth $587 million last year.

“The increasing adoption of devices such as smartphones, tablets, and laptops, and access to the internet through broadband, 3G, etc, have contributed to the rapid growth of the online consumer base,” said a recent report by Technopak. India’s Internet user base is expected to reach 550 million by 2020, with penetration of about 40 per cent, against the current estimated base of 243 million and penetration of 19 per cent.

Valuable spin-offs from carbon nanotube research

With the sophisticated computerisation of the instrument, the measurements can be done in a fully programmable and controlled manner.

Irrespective of its goal, a scientific research project may sometimes throw up gifts for the researcher that are worth being showcased as well. This is what has happened in the case of Piyush Jagtap, research scholar at Indian Institute of Science’s (IISc) Department of Materials Engineering, who found not one, but two such gifts. One, the invention of a device to measure changes in material property as it moves through an electric field and two, the discovery that carbon nanotube foam can form an effective smart shock absorber in devices such as cell phones.

Guided by his thesis adviser, Dr. Praveen Kumar, Piyush’s research into the properties of carbon nanotubules in an electric field led him to build up, from scratch, an instrument to study the properties of small objects moving in an electric field and also develop the methodology to analyse the measurements.

With the sophisticated computerisation of the instrument, the measurements can be done in a fully programmable and controlled manner. For instance, they can study what happens when the electric field is increased in a pre-programmed way or is switched off while loading and switched on while unloading, or any complicated sequence that is desired. Before they built up this device, there existed no other way of executing this task.

Second spin-off

One of the first things the researchers did was to study the mechanical properties of carbon nanotube foam. They found that the shock-absorbent properties of this material actually get enhanced when it is subjected to an electric field. “If subjected to an electric field of 2 volt per millimetre length of the material, its shock-absorbent properties are enhanced six to seven times,” says Dr. Praveen Kumar. This is good news, for it conveys that carbon nanotube foam would make a good inclusion in mobile phones and such small devices as a shock absorber — smart shock absorber is the word for it. Such shock absorbers become particularly relevant and important as the electronics inside mobile devices such as phones and tablets are becoming increasingly fragile with miniaturisation and increasing current density (electric current per unit area).

The duo is the first to have studied this behaviour, especially because such a device for measuring the effect of a field on a small moving item never existed earlier.

“Developing the instrument took us about four to five months, but we had spent more than a year thinking about the larger problem — the mechanical behaviour of the response of carbon nanotubes in an electric field,” says Dr. Kumar, adding that this work will further pave the way to exploration and collaborations to study different materials.

Taj: the pollutants causing discolouration identified

Particulate carbon and fine dust particles cause browning of the marble

Finally, the specific pollutants in the air that are responsible for the discolouration of the white marble of Taj Mahal have been identified. Particulate carbon and fine dust particles that are deposited on the marble are responsible for its browning.

Carbon is of two types — black carbon and light absorbing organic carbon or brown carbon. The results from a study were published a few days ago in the journal Environmental Science & Technology.

Besides studying air samples collected from the area, the authors used marble samples on the building to collect the pollutants. They also undertook computer modelling to study the colour change brought about by reflectance of the particles.

Both organic carbon and dust particles have the ability to preferentially absorb light in the blue region of the spectrum. The absorption of blue light by these pollutants in turn gives the marble surface a brown hue.

“There is one group of organic carbon which absorbs light in the blue region of the spectrum and this is called brown carbon. Discolouration is because of what is happening to reflectance, and reflectance is in turn influenced by these particles,” said Prof. S.N. Tripathi from the Department of Civil Engineering and Centre for Environmental Science and Engineering, Indian Institute of Technology (IIT), Kanpur. He is one of the authors of the paper.

Role of dust particles

The ability of fine dust particles to produce the brown hue is a well known in North India. According to him, it is the presence of haematite in the dust that is responsible for the brown hue.

“If haematite is not present in the dust then the dust would be only scattering in nature,” he said. Haematite is the ingredient that absorbs the blue wavelength of the spectrum.

Though the absorption of blue light by individual dust particles may be smaller than that by brown carbon, the copious amount of dust of two micron size found in the particulate matter makes the overall absorption much higher than that by brown carbon.

The study revealed that particles larger than two micron in size accounted for nearly 70 per cent of the deposited particle surface area. These relatively coarse particles are by default the dust particles.

Pure dust particles per se do not have the ability to stick to surfaces. “But what we see is a potpourri of particles. The organic carbon is very sticky,” Prof. Tripathy said. Unlike the dust particles, carbon particles are in the 100 nanometre to 1 micron size. Burning of biomass like wood and dung, burning of trash and crop residue are the primary sources of brown and black carbon.

On studying the marble samples, the researchers found that black carbon produces a greyish discolouration, while brown carbon and dust produce yellowish-brown hues.

A combination of these two result in darker shades of yellow-brown. The sample targets were in place only for a brief period of two months.

“We found the colour of surrogate marbles matched well with model results. Modelling showed the combined effect of dust and carbon in discolouration of the marble samples,” he said

Five things to know about Isro's GSLV Mark III mission

The Indian Space Research Organisation (Isro) will launch its first experimental suborbital flight today. 

This will be the test launch for Isro's heaviest and upgraded rocket, the GSLV - Mark III, which is carrying the Crew Module Atmospheric Re-entry Experiment (CARE).

The flight will take off from Isro's space station Sriharikotta, near Chennai. Here are five things you need to know about the GSLV - Mark III mission.

1) After its successful Mars mission, this is Isro's next step to put a man in space

2) The Rs 155 crore mission has twin purposes -- the main purpose is to test the rocket’s atmospheric flight stability with around 4-tonne luggage. The second is to study the re-entry characteristics of the crew module called Crew Module Atmospheric Re-entry Experiment.

3) Other critical technologies are also to be developed for Isro's manned mission. These are being developed parallelly at other centres. But recovery of the capsule from out of atmosphere will be the first to be tested. 

4) GSLV Mark III is the heaviest next generation rocket, conceived and designed to make Isro self reliant in launching heavier communication satellites of INSAT-4 class, which weigh 4,500 to 5,000 kg. Once operational, this rocket will have the capability to ferry four-tonne class of Insat series of communication satellites, which are currently being launched through Arianespace.

5) This is the second mission of the GSLV rocket during the last four years after two such launches failed in 2010.

ISRO launches India’s biggest rocket GSLV Mark III from Sriharikota -

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Historic thaw in U.S.-Cuba relations announced

As part of the secret negotiations to secure his release, the U.S. was releasing three Cubans jailed in Florida for spying.

The United States and Cuba on Wednesday agreed to re-establish diplomatic relations and open economic and travel ties, marking a historic shift in U.S. policy towards the island after a half-century of enmity dating back to the Cold War.

The announcement came amid a series of sudden confidence-building measures between the long-time foes, including the release of American prisoner Alan Gross, as well as a swap for a U.S. intelligence asset held in Cuba and the freeing of three Cubans jailed in the U.S. Gross arrived at Andrews Air Force Base outside Washington.

President Barack Obama and Cuban President Raul Castro were to separately address their nations around noon. The two leaders spoke by phone for more than 45 minutes Tuesday, the first substantive presidential-level discussion between the U.S. and Cuba since 1961.

Wednesday’s announcements followed more than a year of secret talks between U.S. and Cuban officials in Canada and the Vatican. U.S. officials said Pope Francis was personally engaged in the process and sent separate letters to Obama and Castro this summer urging them to restart relations.

Officials spoke on the condition of anonymity because they were not authorized to discuss the matter publicly ahead of Obama’s remarks.

Gross, 65, arrived back in the U.S. shortly before Obama was to address the nation. Gross was released after more than five years in prison. He was accompanied by his wife, Judy, along with several U.S. lawmakers.

As part of resuming diplomatic relations with Cuba, the U.S. will soon reopen an embassy in the capital of Havana and carry out high-level exchanges and visits between the governments. The U.S. is also easing travel bans to Cuba, including for family visits, official U.S. government business and educational activities. Tourist travel remains banned.

Licensed American travelers to Cuba will now be able to return to the U.S. with $400 in Cuban goods, including tobacco and alcohol products worth less than $100 combined. This means the long-standing ban on importing Cuban cigars is over, although there are still limits.

The U.S. is also increasing the amount of money Americans can send to Cubans from $500 to $2,000 per quarter, or every three months. Early in his presidency, Obama allowed unlimited family visits by Cuban-Americans and removed a $1,200 annual cap on remittances. Secretary of State John Kerry is also launching a review of Cuba’s designation as a state sponsor of terror.

Obama does not have the authority to fully lift the long—standing U.S. economic embargo on Cuba, given that Congress enacted that policy. However, officials said he would welcome lawmakers taking that step.

There remains a divide on Capitol Hill over U.S. policy toward Cuba. While some lawmakers say the embargo is outdated, others say it’s necessary as long as Cuba refuses to reform its political system and improve its human rights record.

Sen. Marco Rubio, R-Florida, said the policy Obama was to announce on Wednesday did nothing to address those issues.

“But it potentially goes a long way in providing the economic lift that the Castro regime needs to become permanent fixtures in Cuba for generations to come,” Rubio said.

U.S. officials said Cuba was taking some steps as part of the agreement to address its human rights issues, including freeing 53 political prisoners.

Cuba was also releasing a non-American U.S. intelligence ‘asset’ along with Gross. Officials said the spy had been held for nearly 20 years and was responsible for some of the most important counterintelligence prosecutions that the United States has pursed in recent decades. That includes convicted Cuban spies Ana Belen Montes, Walter Kendall Myers and Gwendolyn Myers and a group known as the Cuban Five.

The three Cubans released in exchange for the spy are part of the Cuban Five a group of men who were part of the “Wasp Network” sent by Cuba’s then-President Fidel Castro to spy in South Florida. The men, who are hailed as heroes in Cuba, were convicted in 2001 in Miami on charges including conspiracy and failure to register as foreign agents in the U.S.

Two of the Cuban Five were previously released after finishing their sentences.

Gross was detained in December 2009 while working to set up Internet access as a subcontractor for the U.S. government’s U.S. Agency for International Development, which does work promoting democracy in the communist country. It was his fifth trip to Cuba to work with Jewish communities on setting up Internet access that bypassed local censorship.

Bonnie Rubinstein, Gross’ sister, heard the news from a cousin, who saw it on television.

“We’re like screaming and jumping up and down,” she said in a brief telephone interview from her home in Texas.

Cuba considers USAID’s programs illegal attempts by the U.S. to undermine its government, and Gross was tried and sentenced to 15 years in prison.

Gross’ family has said he was in ailing health. His wife, Judy, said in a statement earlier this month that Gross has lost more than 100 pounds 45 kilograms), can barely walk due to chronic pain, and has lost five teeth and much of the sight in his right eye.

Obama has taken some steps to ease U.S. restrictions on Cuba after Raul Castro took over as president in 2010 from his ailing brother. He has sought to ease travel and financial restrictions on Americans with family in Cuba, but has resisted calls to drop the embargo.