IIT-G develops device that separates oil from water

Agencies
August 19, 2019

New Delhi, Aug 19: Researchers at the Indian Institute of Technology (IIT) Guwahati have developed a device that can continuously separate oil from water by strategic use of fish-scale and lotus-leaf inspired membranes.

The team developed the system of materials by combining the lotus leaf-inspired super-water repellence and fish scale-mimicked underwater super-oil repellence.

The membranes that are super-water repellent in air, and super oil-repellent in water, have been shown to separate complex mixtures of oil and water at practically relevant settings, according to the journal ACS Sustainable Chemistry & Engineering.

Oil-water separation is also important in environmental applications like oil spill management.

The team then developed a prototype of oil-water separation device using these membranes so that the separated oil and water were simultaneously collected in different containers.

"Oil-water separation is of current relevance because many industries, such as mining, textiles, food and petrochemicals, produce massive volumes of oily wastewater, which must be treated before discharge," said Uttam Manna, Assistant Professor, Department of Chemistry, IIT Guwahati.

The lotus leaf for example, is water repellent so that it does not get soggy in its living space, researchers said.

Fish, on the other hand, has a body surface that repels oil in order to survive in polluted waters, they said.

Scientists have studied the surface structures of lotus leaves and fish scales to understand what gives them their superhydrophobicity (super-water repellence) and superoleophobicity (super-oil repellence), so that these structures can be replicated artificially for oil-water separation applications.

Lotus leaf-inspired superhydrophobic materials and fish scale-inspired superoleophobic materials were developed following a single and unique deposition process and tested for gravity-driven removal of oil from water.

While these bio-inspired membranes are individually used to separate oil and water in the recent past, there is accumulation of water or oil on the membrane over time, which blocks further separation.

"There is yet another problem with conventional demonstration, where the superhydrophobic and superoleophobic materials are mostly used for two phase oil/water mixtures," Manna said.

"However, those approaches are inappropriate for separation of three-phase mixtures of heavy oil, light oil and water," he said.

These materials are required to operate under harsh conditions; they are subjected to severe stretching and bending during operation, which make them physically unstable, researchers said.

In order to overcome the problems, Manna and his team developed a system of 'super liquid repellent' materials, by combining the lotus leaf superhydrophobicity and fish scale superoleophobicity.

Layer-by-layer deposition technique was used to obtain alternating layers of 'chemically reactive polymeric nano-complex' and 'amino graphene oxide nanosheets' on a stretchable and fibrous substrate.

The durable and stretchable membranes that the team developed were super-water-repellent in air and super-oil-repellent in water.

"These separation systems allow continuous, parallel and selective separation of various oil/water mixtures, irrespective of surface tension, density, and viscosity of the oil phase and chemical complexity in the water phase," Manna said.

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Agencies
June 7,2020

New Delhi, Jun 7: The Government of India (GoI) must strengthen the laws to protect animals, said People for the Ethical Treatment of Animals (PETA) India CEO Dr Manilal Valliyate on Sunday, following an elephant's death in Kerala and cow injured due to ingestion of explosives in Himachal Pradesh.

"Such incidents are not just restricted to certain regions but are happening all across the country. PETA receives more than 100 similar cases every day. People send in their complaints to us, not just for cows and elephants but for so many other animals as well," he said.

The PETA chief urged the GoI to strengthen the laws established to protect animals.

"As per the current laws set out against animal cruelty, the perpetrator would only be charged Rs 50,000 as a fine. That is equivalent to no punishment at all," added PETA India CEO.

He expressed his anguish against municipal agencies as well, saying that they are not doing "serious" work. He also highlighted how cows are left on the roads to wander, after milking them, to feed on garbage, in several parts of the country.

"These injustices against animals through explosives has been going on for quite a while. But for the first time, it has received such public attention," he said.

After a pregnant elephant was fed cracker-filled pineapple and her eventual death on May 27 in Kerala's Palakkad district, a pregnant cow sustained fatal injuries on May 25 due to accidental ingestion of explosives in Dadh village of Bilaspur district of Himachal Pradesh.

One person has been arrested in the Dadh village for allegedly hurting the cow.

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Agencies
June 8,2020

Washington DC, Jun 8: Astronomers acting on a hunch have likely resolved a mystery about young, still-forming stars and regions rich in organic molecules closely surrounding some of them.

They used the National Science Foundation's Karl G Jansky Very Large Array (VLA) to reveal one such region that previously had eluded detection and that revelation answered a longstanding question.

The regions around the young protostars contain complex organic molecules which can further combine into prebiotic molecules that are the first steps on the road to life.

The regions, dubbed "hot corinos" by astronomers, are typically about the size of our solar system and are much warmer than their surroundings, though still quite cold by terrestrial standards.

The first hot corino was discovered in 2003 and only about a dozen have been found so far. Most of these are in binary systems, with two protostars forming simultaneously.

Astronomers have been puzzled by the fact that, in some of these binary systems, they found evidence for a hot corino around one of the protostars but not the other.

"Since the two stars are forming from the same molecular cloud and at the same time, it seemed strange that one would be surrounded by a dense region of complex organic molecules and the other wouldn't," said Cecilia Ceccarelli, of the Institute for Planetary Sciences and Astrophysics at the University of Grenoble (IPAG) in France.

The complex organic molecules were found by detecting specific radio frequencies, called spectral lines, emitted by the molecules. Those characteristic radio frequencies serve as "fingerprints" to identify the chemicals.

The astronomers noted that all the chemicals found in hot corinos had been found by detecting these "fingerprints" at radio frequencies corresponding to wavelengths of only a few millimetres.

"We know that dust blocks those wavelengths, so we decided to look for evidence of these chemicals at longer wavelengths that can easily pass through dust," said Claire Chandler of the National Radio Astronomy Observatory, and principal investigator on the project.

"It struck us that dust might be what was preventing us from detecting the molecules in one of the twin protostars," added Chandler.

The astronomers used the VLA to observe a pair of protostars called IRAS 4A, in a star-forming region about 1,000 light-years from Earth. They observed the pair at wavelengths of centimetres.

At those wavelengths, they sought radio emissions from methanol, CH3OH (wood alcohol, not for drinking). This was a pair in which one protostar clearly had a hot corino and the other did not, as seen using the much shorter wavelengths.

The result confirmed their hunch. "With the VLA, both protostars showed strong evidence of methanol surrounding them. This means that both protostars have hot corinos. The reason we did not see the one at shorter wavelengths was because of dust," said Marta de Simone, a graduate student at IPAG who led the data analysis for this object.

The astronomers cautioned that while both hot corinos now are known to contain methanol, there still may be some chemical differences between them. That, they said, can be settled by looking for other molecules at wavelengths not obscured by dust.

"This result tells us that using centimetre radio wavelengths is necessary to properly study hot corinos," Claudio Codella of Arcetri Astrophysical Observatory in Florence, Italy, said.

"In the future, planned new telescopes such as the next-generation VLA and SKA, will be very important to understanding these objects," added Codella.

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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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