Imran Khan now marries his spiritual guide Bushra Maneka

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.

Maryland, Jul 4: The total number of coronavirus cases worldwide has touched 11 million, according to the latest data by the Johns Hopkins University on Saturday.
More than 523,613 people have died globally due to the infection, according to the data compiled by the university.

Though the virus is believed to have emerged from the Chinese city of Wuhan, the United States is the worst-hit country from COVID-19, which was declared as a pandemic by the WHO on March 11.

At least 129,275 people have died in the US from the coronavirus, according to Johns Hopkins University's latest tally.
There are at least 2,786,178 cases of the disease in the country. The US has the highest number of cases in the world.

The second worst-hit country is Brazil, which has reported 1,496,858 lakh cases. The country's death toll stands at 61,884.

The countries around the world including the US, India, Denmark, and Italy have started the process of lifting the lockdown by easing restrictions despite the number of cases continues to rise.

New Delhi, Mar 9: The Centre and the Delhi government are working in close coordination to deal with coronavirus, Chief Minister Arvind Kejriwal said here on Monday.

Talking to reporters after a review meeting with Union Health Minister Harsh Vardhan on the preparedness for COVID-19, the chief minister said people arriving from foreign countries are being screened at airports.

A campaign will be run to make people aware of the preventive measures to contain the spread of the disease, Kejriwal said.

Health Ministry sending directives to states: Vardhan

Health Minister Harsh Vardhan said the government is prepared to deal with novel coronavirus and his ministry is sending directives, including guidelines, to states in all the languages on ways to contain it.

"We are sending detailed guidelines to all states on ways to contain coronavirus. Have asked states to strengthen laboratories and manpower to effectively deal with coronavirus and form early rapid action teams," Vardhan told reporters adding, that the government is prepared to deal with the infection.

Vardhan stressed on a coordinated action between all concerned departments and agencies for activities such as contact tracing, community surveillance, hospital management, identification of isolation wards, ensuring adequate personal protection equipment and masks and risk communication for mass awareness.