Why BJP has not built bigger statue for Mahatma Gandhi: Shashi Tharoor

New Delhi, May 30: An Air India flight from Delhi to Moscow on Saturday had to return midway after the airline's ground team found out that one of the pilots had tested positive for novel coronavirus, officials said.

"When the A320 plane, which did not have any passengers as it was heading to Moscow to bring back stranded Indians under Vande Bharat Mission, had reached Uzbekistan's airspace, our team on ground realised that one of the pilots had tested COVID-positive," senior Air India officials said.

"The flight was immediately asked to return. It came back to Delhi at around 12.30 pm on Saturday," the officials said. The crew has been quarantined. Another plane would be sent to Moscow to bring back the stranded Indians, according to the officials.

Srinagar, Apr 4: Two militants were reportedly killed in an encounter with security forces in Kulgam district of Jammu and Kashmir on Saturday, police said.

The security forces launched a cordon and search operation based on intelligence inputs about the presence of militants in Hardmand Guri village in Kulgam, a police spokesperson said.

"This operation based on a credible police input was launched this morning. Two terrorists have been reportedly killed so far," the spokesperson said, adding that the exchange of fire was going on.

Earlier, the police tweeted on its official handle that three militants had been trapped in the cordon. "Same group of #terrorists trapped who killed 3 civilians recently," the police said.

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.