Want to assure brothers, sisters of Assam they have nothing to worry after CAB: PM Modi

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.

Bengaluru, May 29: Former prime minister H D Deve Gowda mourned the demise of Rajya Sabha member and Managing Director of leading Malayalam daily Mathrubhumi M P Veerendra Kumar, hailing him as a great journalist and writer.

"My deepest condolences on the demise of former union Minister and Rajya sabha member Shri M.P. Veerendra Kumar. He was a great journalist and writer. May god give strength to his family & his people to bear the loss," Gowda said in his condolence message.

Veerandra Kumar, who was a member of PTIs Board of Directors, died late Thursday at a private hospital in Kozhikode in Kerala following cardiac arrest.

New Delhi, Jul 7: Diesel price in the national capital on Tuesday touched an all-time high following a rate hike after a week-long hiatus.

Diesel price on Tuesday was increased by 25 paise per litre, according to a price notification of state-owned oil marketing companies.

This took the retail selling price of diesel to Rs 80.78 per litre in the national capital - the highest ever.

There was no change in petrol price for the 8th straight day, and it continues to be priced at Rs 80.43 per litre.

Rates vary from state to state depending on the incidence of local sales tax or VAT.

Petrol and diesel price were last revised on June 29.

In the last one month, diesel price has been increased on 23 occasions while petrol rates have risen 21 times.

The cumulative increase since the oil companies started the cycle on June 7, totals to Rs 9.17 for petrol and Rs 11.39 in diesel.

In Mumbai, petrol is priced at Rs 87.19 - unchanged since June 29, while diesel was hiked to Rs 79.05 a litre from Rs 78.83.