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 15,2020

New Delhi, Jul 15: The employees union of state-run telecom operator BSNL will stage protests across the country on Thursday on a host of issues including the cancellation of its 4G tender and non-payment of salaries.

All major unions are organising ‘lunch-hour black-flag' demonstrations throughout the country under the banner of All Unions and Association of BSNL (AUAB), said a statement by AUAB. These demonstrations will be organised, by maintaining social distancing and by taking other precautions, like wearing of masks. The BSNL employees will also wear black-badges the whole day on July 16.

The employees body would demand that BSNL should immediately be allowed to roll out its 4G services and the tender should be issued immediately. Further, they want that in the matter of procuring new equipment and upgradation, there should not be any discrimination between BSNL and other private telecom service providers.

Recently, the Centre cancelled the 4G upgradation tender for BSNL as it had decided to come up with fresh specifications for the upgrade process, in a move to keep Chinese technology companies at bay as the border tussle escalated with the northern neighbour.

The Department of Telecommunications (DoT) would issue a fresh tender for the same, and people in the know said that Chinese companies may not be allowed to participate.

"The agitational programme is being organised to express the deep anguish and resentment of the employees against cancellation of BSNL's 4G tender, cancellation of BSNL's proposal for upgradation of its 49,300 BTSs to 4G, abnormal delay in issuing ‘Add on Order' for 4G equipments, inordinate delay in the implementation of BSNL's Revival Package and against the non-settlement of the burning problems of the employees," said the statement.

The umbrella body of BSNL's employees' unions noted that rolling out of 4G services is the backbone for the revival of this telecom PSU, but the recent cancellation of the tender floated by BSNL for procuring 4G equipment at a cost of Rs 9,300 crore, has brought the company back to square one.

It said that BSNL is already having 49,300 base transceiver stations (BTS), which are 4G compatible and through minor upgradation, all these equipment can be converted into 4G BTSs with an investment of about Rs 1,500 crore.

In addition to this, BSNL could have added another 15,000 BTSs, by placing an Add on Order to the existing mobile tender, it added.

Noting that in October 2019, the PSU could have rolled out pan-India 4G services, AUAB said: "Being the sole owner of the company, the Government of India also cannot shirk its responsibility in this matter."

"Adding insult to injury, the tender floated by BSNL to procure 4G equipment, has been cancelled by the government, based on a complaint from the Telecom Equipments and Services Promotional Council (TEPC)," it said.

AUAB said that BSNL is already lagging four years behind the private operators, in terms of 4G and the cancellation of the tender is going to inordinately delay the company's 4G launch.

Saying that TEPC's contention has been to bar foreign companies from participating in BSNL's tender, AUAB statement pointed out that when private operators are procuring equipment from multinationals, "why BSNL alone should be compelled to procure 4G equipments from domestic vendors, whose 4G technology is not tested or proven so far."

It alleged a conspiracy to destabilise BSNL by disrupting its rolling out of 4G services.

AUAB further said that even after the lapse of nine months, the implementation of the much publicised BSNL's Revival Package is moving at a snail's pace.

"Except the swift retrenchment of 79,000 BSNL employees under VRS, all other assurances given in BSNL's Revival Package have been put in cold storage."

The management should ensure that the salary payment of the employees is made on the last working day of every month. Deductions made from employees' salary, on account of "society dues", should immediately be remitted, it said.

Regarding the monetisation of the company's assets under the revival package, the organisation said that the land asset should not be handed over to corporates, at "throwaway" prices.

"These lands should be sold in a transparent manner and at the prevailing market rates. They should not be sold at book value or at circle rates. The AUAB will strictly monitor these dealings," it said.

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Agencies
February 6,2020

Washington D.C., Feb 6: An international team of astronomers has found an unusual monster galaxy that existed about 12 billion years ago when the universe was only 1.8 billion years old.

The team of astronomers was led by scientists at the University of California, Riverside.

Dubbed XMM-2599, the galaxy formed stars at a high rate and then died. Why it suddenly stopped forming stars is unclear.

"Even before the universe was 2 billion years old, XMM-2599 had already formed a mass of more than 300 billion suns, making it an ultra massive galaxy," said Benjamin Forrest, a postdoctoral researcher in the UC Riverside Department of Physics and Astronomy and the study's lead author.

"More remarkably, we show that XMM-2599 formed most of its stars in a huge frenzy when the universe was less than 1 billion years old and then became inactive by the time the universe was only 1.8 billion years old," Forrest added.

The team used spectroscopic observations from the W. M. Keck Observatory's powerful Multi-Object Spectrograph for Infrared Exploration or MOSFIRE, to make detailed measurements of XMM-2599 and precisely quantify its distance.

The study results appear in the Astrophysical Journal.

"In this epoch, very few galaxies have stopped forming stars, and none are as massive as XMM-2599," said Gillian Wilson, a professor of physics and astronomy at UCR in whose lab Forrest works.

"The mere existence of ultramassive galaxies like XMM-2599 proves quite a challenge to numerical models. Even though such massive galaxies are incredibly rare at this epoch, the models do predict them."

"The predicted galaxies, however, are expected to be actively forming stars. What makes XMM-2599 so interesting, unusual, and surprising is that it is no longer forming stars, perhaps because it stopped getting fuel or its black hole began to turn on. Our results call for changes in how models turn off star formation in early galaxies," the professor stated.

The research team found XMM-2599 formed more than 1,000 solar masses a year in stars at its peak of activity -- an extremely high rate of star formation. In contrast, the Milky Way forms about one new star a year.

"XMM-2599 may be a descendant of a population of highly star-forming dusty galaxies in the very early universe that new infrared telescopes have recently discovered," said Danilo Marchesini, an associate professor of astronomy at Tufts University and a co-author on the study.

"We have caught XMM-2599 in its inactive phase," Wilson said, who led the W. M. Keck Observatory data acquisition
Co-author Michael Cooper, a professor of astronomy at UC Irvine, said this outcome is a strong possibility.

"Perhaps during the following 11.7 billion years of cosmic history, XMM-2599 will become the central member of one of the brightest and most massive clusters of galaxies in the local universe," he said.

"Alternatively, it could continue to exist in isolation. Or we could have a scenario that lies between these two outcomes," he stated.

The study was supported by grants from the National Science Foundation and NASA.

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Agencies
July 4,2020

The Mars Colour Camera (MCC) onboard ISRO's Mars Orbiter Mission has captured the image of Phobos, the closest and biggest moon of Mars.

The image was taken on July 1 when MOM was about 7,200 km from Mars and 4,200 km from Phobos.

"Spatial resolution of the image is 210 m.

This is a composite image generated from 6 MCC frames and has been color corrected," ISRO said in an update along with the image.

Phobos is largely believed to be made up of carbonaceous chondrites.

According to ISRO, "the violent phase that Phobos has encountered is seen in the large section gouged out from a past collision (Stickney crater) and bouncing ejecta."

"Stickney, the largest crater on Phobos along with the other craters (Shklovsky, Roche & Grildrig) are also seen in this image," it said.

The mission also known as Mangalyaan was initially meant to last six months, but subsequently ISRO had said it had enough fuel for it to last "many years."

The country had on September 24, 2014 successfully placed the Mars Orbiter Mission spacecraft in orbit around the red planet, in its very first attempt, thus breaking into an elite club.

ISRO had launched the spacecraft on its nine-month- long odyssey on a homegrown PSLV rocket from Sriharikota in Andhra Pradesh on November 5, 2013.

It had escaped the earth's gravitational field on December 1, 2013.

The Rs 450-crore MOM mission aims at studying the Martian surface and mineral composition as well as scan its atmosphere for methane (an indicator of life on Mars).

The Mars Orbiter has five scientific instruments - Lyman Alpha Photometer (LAP), Methane Sensor for Mars (MSM), Mars Exospheric Neutral Composition Analyser (MENCA), Mars Colour Camera (MCC) and Thermal Infrared Imaging Spectrometer

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