Even if God asks me, I won't forgive, says Nirbhaya's mother

London, May 20: The current physical distancing guidelines of 6 feet may be insufficient to prevent COVID-19 transmission, according to a study which says a mild cough in low wind speeds can propel saliva droplets by as much as 18 feet.

Researchers, including those from the University of Nicosia in Cyprus, said a good baseline for studying the airborne transmission of viruses, like the one behind the COVID-19 pandemic, is a deeper understanding of how particles travel through the air when people cough.

In the study, published in the journal Physics of Fluids, they said even with a slight breeze of about four kilometres per hour (kph), saliva travels 18 feet in 5 seconds.

"The droplet cloud will affect both adults and children of different heights," said study co-author Dimitris Drikakis from the University of Nicosia.

According to the scientists, shorter adults and children could be at higher risk if they are located within the trajectory of the saliva droplets.

They said saliva is a complex fluid, which travels suspended in a bulk of surrounding air released by a cough, adding that many factors affect how saliva droplets travel in the air.

These factors, the study noted, include the size and number of droplets, how they interact with one another and the surrounding air as they disperse and evaporate, how heat and mass are transferred, and the humidity and temperature of the surrounding air.

In the study, the scientists created a computer simulation to examine the state of every saliva droplet moving through the air in front of a coughing person.

The model considered the effects of humidity, dispersion force, interactions of molecules of saliva and air, and how the droplets change from liquid to vapour and evaporate, along with a grid representing the space in front of a coughing person.

Each grid, the scientists said, holds information about variables like pressure, fluid velocity, temperature, droplet mass, and droplet position.

The study analysed the fates of nearly 1,008 simulated saliva droplets, and solved as many as 3.7 million equations.

"The purpose of the mathematical modelling and simulation is to take into account all the real coupling or interaction mechanisms that may take place between the main bulk fluid flow and the saliva droplets, and between the saliva droplets themselves," explained Talib Dbouk, another co-author of the study.

However, the researchers added that further studies are needed to determine the effect of ground surface temperature on the behaviour of saliva in air.

They also believe that indoor environments, especially ones with air conditioning, may significantly affect the particle movement through air.

This work is important since it concerns safety distance guidelines, and advances the understanding of the transmission of airborne diseases, Drikakis said.

New Delhi, Mar 14: Excise duty on petrol and diesel was on Saturday hiked by ₹3 per litre as the government looked to mop up gains arising from fall in international oil prices.

Special excise duty on petrol was hiked by ₹2 to ₹8 per litre incase of petrol and to Rs 4 incase of diesel, an official notification said.

Additionally, road cess on petrol was raised by ₹1 per litre each on petrol and diesel to ₹10.

The increase in excise duty would in normal course result in a hike in petrol and diesel prices but most of it would be adjusted against the fall in rates that would have necessitated because of slump in international oil prices.

Mumbai, Mar 9: India's Yes Bank will not be merged with State Bank of India, which is set to infuse funds in the beleaguered lender, the newly appointed administrator leading the rescue plan said in a television interview on Monday.

"There is absolutely no question of a merger," Prashant Kumar, the administrator, told the CNBC TV18 channel.

The Reserve Bank of India (RBI) on Thursday took control of Yes Bank, after the lender - which is laden with bad debts - failed to raise the capital it needs to stay above mandated regulatory requirements.

Placing Yes Bank under a 30-day moratorium, the central bank imposed limits on withdrawals to protect depositors and said it would work on a revival plan. The move spooked depositors, who rushed to withdraw funds from the bank.

Kumar, a former finance chief at SBI, assured depositors their money was safe and that the moratorium on Yes Bank might be lifted much before the deadline on April 3 and normal banking operations might resume as early as Friday.

He also mentioned that the withdrawal limit of Yes Bank may be removed by March 15, 2020.

SBI Chairman Rajnish Kumar said on Saturday the state-run bank would need to invest up to 24.5 billion rupees ($331 million) to buy a 49% stake in Yes Bank as part of the initial phase of the rescue deal, adding that the survival of troubled lender was a "must".