Never ever visited any rowdy’s home; will retire from politics if allegations proven: UT Khader

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, May 10: Congress leader Rahul Gandhi on Saturday demanded that Prime Minister Narendra Modi ensured audit of donations made to the PM-CARES Fund, and to share the details and the money spent with the people.

"The PM-CARES Fund has received huge contributions from PSUs and major public utilities like the Railways. It's important that the Prime Minister ensure the fund is audited and that the record of money received and spent is available to the public," he tweeted.

The #PmCares fund has received huge contributions from PSUs & major public utilities like the Railways.

It’s important that PM ensures the fund is audited & that the record of money received and spent is available to the public.

— Rahul Gandhi (@RahulGandhi) May 9, 2020
His remarks came amid reports that the central government is accumulating a huge sum of money in the Prime Minister's Citizen Assistance and Relief in Emergency Situations Fund set up as a corpus to fight novel coronavirus and that the amount spent will not be audited by the Comptroller and Auditor General.

The CAG office had clarified that since the fund is based on donations, it has no right to audit a charitable organisation.

On Friday, Rahul Gandhi told the media that the PM-CARES Fund should be audited and people of the country should know about the donors and the donations made.