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
July 25,2020

In a study conducted in 117 countries, researchers have found that the world is experiencing the most dramatic reduction in the seismic noise (the hum of vibrations in the planet's crust) in recorded history due to global COVID-19 lockdowns.

Measured by instruments called seismometers, seismic noise is caused by vibrations within the Earth, which travel like waves and the waves can be triggered by earthquakes, volcanoes, and bombs - but also by daily human activity like travel and industry.

This quiet period was likely caused by the total global effect of social distancing measures, closure of services and industry, and drops in tourism and travel, the study published in the journal Science, reported.

The new research, led by the Royal Observatory of Belgium and five other institutions around the world including Imperial College London (ICL), showed that the dampening of 'seismic noise' caused by humans was more pronounced in more densely populated areas.

"Our study uniquely highlights just how much human activities impact the solid Earth, and could let us see more clearly than ever what differentiates human and natural noise," said study co-author Stephen Hicks from ICL in the UK.

For the findings, the research team looked at seismic data from a global network of 268 seismic stations in 117 countries and found significant noise reductions compared to before any lockdown at 185 of those stations.

Researchers tracked the 'wave' of quietening between March and May as worldwide lockdown measures took hold.

The largest drops in vibrations were seen in the most densely populated areas, like Singapore and New York City, but drops were also seen in remote areas like Germany's the Black Forest and Rundu in Namibia.

Citizen-owned seismometers, which tend to measure more localised noise, noted large drops around universities and schools around Cornwall, UK and Boston, US - a drop in noise 20 per cent larger than seen during school holidays.

The findings showed that countries like Barbados, where lockdown coincided with the tourist season, saw a 50 per cent decrease in noise.

"The changes have also given us the opportunity to listen in to the Earth's natural vibrations without the distortions of human input," the study authors wrote.

Earlier in April, a study published in the journal Nature, reported at least a 30 per cent reduction in that amount of ambient human noise since lockdown began in Belgium.

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Agencies
June 18,2020

New Delhi, Jun 18: Vodafone Idea on Thursday told the Supreme Court that it has incurred Rs 1 lakh crore losses as it insisted it is not in a position to furnish bank guarantees.

A bench comprising Justices Arun Mishra, S. Abdul Nazeer, and M.R. Shah, taking up the adjusted gross revenue (AGR) matter through video conferencing, directed the telecom companies to submit their financial documents and books for the last 10 years.

Asking Vodafone if it was a foreign company, the bench said that how can the company say it would not furnish any bank guarantee.

"What if you fly away overnight in future without paying anything?" it asked.

Senior advocate Mukul Rohatgi, representing Vodafone Idea, denied his client is a completely foreign firm and cited before the bench its tie-ups and investments.

Vodafone owes over Rs 58,000 crore as AGR dues and so far, has paid close to Rs 7,000 crore.

Rohatgi contended before the court that the telecom company is in a tough situation, and cannot furnish any fresh bank guarantee, as profits have eluded the company in past many quarters. He submitted before the bench that Rs 15,000 crore bank guarantees are lying with the government, and his client's losses are over Rs 1 lakh crore.

"I cannot offer any more surety," he informed the bench.

Justice Mishra noted that this is public money and these dues should be recovered. "Do not tell us that you will pay if you were to make profits... the money must come," he noted.

Justice Shah observed that the telecom industry is the only industry which earned during the Covid-19 pandemic. "After all, this money will be used for public welfare", he said.

Rohatgi argued that his client would have to fold up if orders were issued to clear dues tomorrow. "11,000 employees will have to go without notice, as we cannot pay them," he added.

Senior advocate Abhishek Manu Singhvi, appearing for Bharti Airtel, contended before the court that out of Rs 21,000 crore AGR dues, the company has already deposited a sum of Rs 18,000 crore.

He argued that his client has given a bank guarantee, in excess of demand, to DoT, and supported the proposal for phased repayment of remaining AGR dues. He insisted that the company needs to sit down with the government and calculate the dues. Airtel owes Rs 25,976 crore after paying Rs 18,000 crore, as per the government.

Senior advocate Arvind Datar, representing Tata Telecom, informed the bench that his client has paid Rs 6,504 crore in AGR dues so far, and furnishing a bank guarantee may adversely impact investments in the sector.

The total AGR dues are close to Rs 1.5 lakh crore.

The top court will now take up the matter in the third week of July.

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Agencies
March 15,2020

Cybercriminals continue to exploit public fear of rising coronavirus cases through malware and phishing emails in the guise of content coming from the Centers for Disease Control and Prevention (CDC) in the US and World Health Organisation (WHO), says cybersecurity firm Kaspersky.

In the APAC region, Kaspersky has detected 93 coronavirus-related malware in Bangladesh, 53 in the Philippines, 40 in China, 23 in Vietnam, 22 in India and 20 in Malaysia. 

Single-digit detections were monitored in Singapore, Japan, Indonesia, Hong Kong, Myanmar, and Thailand. 

Along with the consistent increase of 2019 coronavirus cases comes the incessant techniques cybercriminals are using to prey on public panic amidst the global epidemic, the company said in a statement. 

Kaspersky also detected emails offering products such as masks, and then the topic became more commonly used in Nigerian spam emails. Researchers also found scam emails with phishing links and malicious attachments.

One of the latest spam campaigns mimics the World Health Organisation (WHO), showing how cybercriminals recognise and are capitalising on the important role WHO has in providing trustworthy information about the coronavirus.

"We would encourage companies to be particularly vigilant at this time, and ensure employees who are working at home exercise caution. 

"Businesses should communicate clearly with workers to ensure they are aware of the risks, and do everything they can to secure remote access for those self-isolating or working from home," commented David Emm, principal security researcher.

Some malicious files are spread via email. 

For example, an Excel file distributed via email under the guise of a list of coronavirus victims allegedly sent from the World Health Organisation (WHO) was, in fact, a Trojan-Downloader, which secretly downloads and installs another malicious file. 

This second file was a Trojan-Spy designed to gather various data, including passwords, from the infected device and send it to the attacker.

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