Create schools, hospitals on 5-acre Ayodhya plot: Salim Khan

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.

Thiruvananthapuram, Feb 29: With Saudi Arabia indefinitely suspending visas for visit to Islam's holiest site for the Umrah pilgrimage in the wake of coronavirus outbreak, more than 10,000 people in the state who are awaiting their turn this year for the annual Hajj pilgrimage are a worried lot.

"This year more than 10,000 people in Kerala have been cleared by the Hajj committee," said C Muhammed Faizy, chairman, Kerala State Hajj Committee.

"There is no cause of worry. We hope that during the time of the pilgrimage, the travel restriction by Saudi Arabia will be lifted," he said.

Umrah is a pilgrimage to the holy site that can be undertaken at any time of the year, while the annual Hajj pilgrimage has specific months according to the lunar calendar.

"The move by the Saudi Arabian Government to impose travel restriction was due to the outbreak of coronavirus. It is a preventive step to contain it. In such large gatherings, if one person is affected, it will spread to others. So we fully understand the concerns of the Saudi Government," Muhammed Faizy added.

He said that the Hajj Committee only processes the requests of annual Hajj visit pilgrims and not Umrah.

"This year we expect the Hajj pilgrimage season to be from June to August after Ramzan. But it may vary according to the Ramzan date. We are yet to get any official correspondence from the Saudi Government regarding travel restrictions," he added.

The Saudi Arabian Government suspended visas for tourists from countries affected by the coronavirus, with many having to cancel their Umrah pilgrimage at the last minute.

New Delhi, Jun 18: India on Wednesday took strong exception to China claiming sovereignty over the Galwan Valley in eastern Ladakh, saying its "exaggerated and untenable claims" are contrary to the understanding reached on the issue between the two sides.

Ministry of External Affairs Spokesperson Anurag Srivastava's response came after China claimed that the Galwan Valley in eastern Ladakh is a part of its territory.

"As we have conveyed earlier today, External Affairs Minister and the State Councillor and Foreign Minister of China had a phone conversation on recent developments in Ladakh," Srivastava said late Wednesday night.

"Both sides have agreed that the overall situation should be handled in a responsible manner and that the understandings reached between Senior Commanders on 6th June should be implemented sincerely. Making exaggerated and untenable claims is contrary to this understanding," he said.

Earlier on Wednesday, India delivered a strong message to China that the "unprecedented" incident in the Galwan Valley will have a "serious impact" on the bilateral relationship and held the "pre-meditated" action by Chinese army directly responsible for the violence that left 20 Indian Army personnel dead.

In a telephonic conversation, External Affairs Minister Jaishankar conveyed to his Chinese counterpart Wang Wi India's protest in the "strongest terms" and said the Chinese side should reassess its actions and take corrective steps, the Ministry of External Affairs said.

The Chinese Foreign Ministry, in a statement, said the two sides agreed to "cool down the situation on the ground as soon as possible", and maintain peace and tranquillity in the border area in accordance with the agreement reached so far between the two countries.

The clash in Galwan Valley on Monday night is the biggest confrontation between the two militaries after their 1967 clashes in Nathu La in 1967 when India lost around 80 soldiers while over 300 Chinese army personnel were killed.

The India-China border dispute covers the 3,488-km-long LAC. China claims Arunachal Pradesh as part of southern Tibet, while India contests it.

Prior to the clashes, both sides have been asserting that pending the final resolution of the boundary issue, it is necessary to maintain peace and tranquillity in the border areas.