Saudi Arabia eyes tourism growth; to begin issuing tourist visas soon

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.

San Francisco, Mar 14: Microsoft on friday announced that co-founder Bill Gates has left its board of directors to devote more time to philanthropy.

The 64-year-old stopped being involved in day-to-day operations at the firm more than a decade ago, turning his attention to the foundation he launched with his wife, Melinda.

Gates served as chairman of Microsoft's board of directors until early in 2014 and has now stepped away entirely, according to the Redmond-based technology giant.

“It's been a tremendous honor and privilege to have worked with and learned from Bill over the years,” Microsoft chief executive and company veteran Satya Nadella said in a release.

Nadella said Microsoft would continue to benefit from Gates' “technical passion and advice” in his continuing role as a technical advisor.
“I am grateful for Bill's friendship and look forward to continuing to work alongside him,” he added.

Gates left his CEO position in 2000, handing the company reins to Steve Ballmer to devote more time to his charitable foundation.

He gave up the role of chairman at the same time Nadella became Microsoft's third CEO in 2014.

Regularly listed among the world's richest people, William H. Gates was a geeky-looking young man when he and Paul Allen co-founded Microsoft in 1975.

Gates went on to turn his attention from software to fighting disease and other humanitarian challenges with his wife, under the auspices of the Bill and Melinda Gates Foundation.

Asia, Jan 15: Iranian Foreign Minister Javad Zarif on Wednesday said that killing of Iranian general Qassem Soleimani showed the ignorance and arrogance of the United States and asserted that Washington looks at things from their perspective and not keeping the interests of the region in mind."The US looks at things from their perspective, not from the perspective of this region. The killing of Qassem Soleimani shows ignorance and arrogance. 430 Indian cities saw protests against killing of Soleimani," Zarif said at an event.

Hitting out at US President Donald Trump and Secretary of State Michael Pompeo, Zarif said that they were the only ones, along with the Islamic State (ISIS) who celebrated the death of Soleimani.

"Who is celebrating Soleimani's killing? President Trump, Pompeo and Daesh (Arabic name of ISIS). You wonder about strange bedfellows?" he said.

Tensions between the US and Iran soared dramatically earlier this month after Washington launched airstrikes at Baghdad International Airport, which killed Soleimani. Tehran retaliated by firing a volley of ballistic missiles at two military bases of US-led coalition forces in Iraq, leading to a strife in the region.

However, Zarif regretted the shooting down of the Ukrainian airline and said it happened because of "tension".

"Nine million people were out in the streets of Iran commemorating Soleimani. You cannot bring out so many people to protest. The shooting down of a plane was a mistake. 180 families are mourning the loss of their dear ones. It happened because of tension," he said.

Asked whether there a chance of a diplomatic solution to the ongoing crisis, Zarif ruled out negotiating with the US.

"Iran is interested in diplomacy. We are not interested in negotiating with the US. US did not keep its commitments under nuclear deal. We had a US deal and the US broke it. If we have a Trump deal, how long will it last?" he said.