‘Unfortunately, couldn’t see sun’: PM blames clouds for missing solar eclipse

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, Feb 4: Miffed over the controversy created by its former Union minister and Uttara Kannada MP Anantkumar Hegde by his remarks against Mahatma Gandhi, the BJP, it was learnt, has issued a show-cause notice to him. The ruling party came under heavy criticism from the opposition over its MP’s remarks. The opposition has demanded a clarification from Prime Minister Narendra Modi over his party MP’s remarks.

Often in news for his controversial remarks, Hegde, sources said, could also be barred from attending the first parliamentary party meeting of the BJP of the budget session, scheduled on Tuesday. The party had taken a similar approach against its Bhopal MP Pragya Thakur during the last winter session for praising Mahatma Gandhi’s killer Nathuram Godse. Though the BJP leadership was earlier of the view that Hegde should tender an apology over his remarks but the party top brass, it was learnt, decided that it was not enough.

The Congress on Monday launched a scathing attack on the central government over the comments of BJP Lok Sabha MP Ananthkumar Hegde on Mahatma Gandhi. The party demanded that Prime Minister Narendra Modi come to Parliament and clarify his position on BJP leader’s “objectionable” remarks.

Congress party spokesman Anand Sharma said, “we can understand that why one after the other senior BJP leaders are insulting the memory of Mahatma Gandhi. They are disparaging the national movement, the freedom struggle because they are ideological descendents of those who were not only non-participants, but, actively opposed the freedom movement.” He further added, “Parliament is in session. We demand that the Prime Minister come to the House and make his position clear. As I have said, feeds that he is unhappy and angry, we are not concerned with that. In the very ideology, mindset, thinking and language of the BJP, there is violence.”

Asserting that the BJP MP’s statement was condemnable, Rajasthan Chief Minister Ashok Gehlot said the leaders of the saffron party could afford to call the freedom movement a drama as they never fought for the country’s independence. “Such statements reveal their true mindset that they use Gandhi's name just for show and have no regard for him,” he said.