'One Nation, One Election' will create confusion among voters: Deve Gowda

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 17: Four death row convicts in the 2012 Nirbhaya gang rape and murder will be hanged on March 3 at 6 am a Delhi court said on Monday.

The Patiala House Court on Monday issued fresh death warrants against four convicts while hearing a petition by the state and Nirbhaya's parents.

Earlier, Delhi High Court on February 5 granted a week's time to the four convicts to avail of all legal remedies available to them and said that the convicts cannot be hanged separately since they were convicted for the same crime.

A Delhi Court had earlier issued a death warrant against the four convicts -- Vinay Sharma, Akshay Thakur, Pawan Gupta, and Mukesh Singh -- on January 7 and they were scheduled to be executed on January 22 at Tihar Jail. Later, the execution was suspended indefinitely by a Delhi court.

New Delhi, Feb 11: AAP leader Sanjay Singh on Tuesday said his party will register a "massive win" in the high-stakes Delhi Assembly election, counting for which began amid tight security at various centres set up to carry out the exercise.

Initial trends suggested the ruling Aam Aadmi Party marching ahead, but the Bharatiya Janata Party leaders maintained that their party would win.

The counting began at 8 am and will be held in multiple rounds, Delhi Chief Electoral Officer Ranbir Singh said.