PM Narendra Modi, Xi Jinping meet in Wuhan for 'heart-to-heart' summit

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.

Apr 11: The number of global coronavirus deaths has increased to 102,753, while the total number of cases worldwide has surpassed 1.6 million, according to the latest update by the Washington-based Johns Hopkins University.

As of Saturday morning, the overall number of infections increased to 1,698,416, while the tally of those who recovered from the deadly disease stood at 376,677, according to the varsity's Center for Systems Science and Engineering (CSSE).

In terms of cases, the US had the highest in the world at 501,301, followed by Spain 158,273, Italy 147,577 and France 125,931.

Italy accounted for the highest death toll at 18,849, with the US in the second place with 18,769 fatalities.

Other countries with more than 10,000 deaths include Spain (16,081) and France (13,197).

Although the pandemic originated in China last December, it now only accounts for 3,343 deaths with 83,003 confirmed cases.

New Delhi, Jan 15: A Delhi court on Wednesday granted bail to Bhim Army chief Chandrashekhar Azad in connection with the Daryaganj violence case.

The court has ordered him not to hold any protest in Delhi till February 16th.

While hearing the case, the Judge had asked Azad's counsel to read out some of his social media posts.

Advocate Mehmood Pracha, representing Azad, had on Tuesday said that the petitioner was sent to jail without any evidence in connection with anti-CAA protests in Delhi's Darya Ganj area last year.

"I think the court's comments should become a precedent for the country. The Public Prosecutor at the behest of police tried to make this a communal issue. We told the court that the government has a problem with Azad because he made the CAA-NPR-NRC an issue for everyone. 
The Court also sought evidence," Pracha told ANI after Delhi's Tis Hazari court deferred the bail plea of Azad till today.

On Wednesday, the court pulled up the Delhi Police for failing to show any evidence against Azad.

Azad was arrested on December 21 last year after he led a march from Jama Masjid against the Citizenship (Amendment) Act. He was sent to judicial custody till January 18 at Tihar jail.

The Bhim Army chief was charged with rioting, unlawful assembly and inciting the mob to indulge in violence after vandalism in Delhi's Daryaganj area.