PM Modi embarks on 'historic' Palestine visit: Here's the full itinerary

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.

Howrah, Jan 8: Following the 'Bharat Bandh' called by trade unions, protesters blocked railway tracks in Howrah and Kanchrapara in North 24 Parganas on Wednesday.

They raised anti-government slogans and criticised the Center for its policies. They were holding placards, posters and banners against the government.

Commuters faced difficulties as bus services were also affected. CPI (M) protesters also stopped the operation of state transport buses. In Odisha, the public agitation started around 6 am at Talcher, Bhubaneswar, Brahmapur, Bhadrak and Kendujhargarh.

Due to the protests, the following trains are detained enroute at different stations --Bhadrak-Brahmapur passenger at Bhadrak, Kendujhargarh-Bhubaneswar passenger at Kendujhargarh, Bhubaneswar-Balangir InterCity at Bhubaneswar, Howrah-Yesvantpur Express at Brahmapur, Ichhapur-Cuttack MEMU at

Brahmapur and Puri-Rourkela passenger at Bhubaneswar.

The ten central trade unions including Centre of Indian Trade Unions (CITU), Indian National Trade Union Congress (INTUC), among others have given the call for strike with a 12-point charter of demand. Trade union Bharatiya Mazdoor Sangh (BMS) is not taking part in the strike.

Dubai, Apr 27: Saudi Arabia has reported 1,289 new Covid-19 cases on April 27, its Ministry of Health tweeted.

Of the newly diagnosed cases, Jeddah recorded 294 infections, followed by Makkah (218) and Madinah (202).

The ministry also confirmed five additional coronavirus-induced deaths, spiking the total death toll to 144.

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Since the outbreak of the virus strain in the Chinese city of Wuhan late last year, Saudi Arabia has reported a total of 18,811 Covid-19 infections.

As many as 2,531 patients have till now recovered from the virus.

Oman
The sultanate registered 51 new Covid-19 cases on April 27, including 37 nationals and 14 expatriates, spiking the total number of infections to 2,049, Oman News Agency tweeted.

Meanwhile, 10 coronavirus-related deaths have been confirmed in the country.

Qatar
The Ministry of Public Health has reported 957 Covid-19 cases among the 3,420 people tested in the last 24 hours.

As many as 85,709 people have been tested for the virus across the country.

The total number of Covid-19 infections since the outbreak has now risen to 11,244.