Saudi denounces US recognition of Golan Heights as Israeli territory

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.

Dubai, May 1: Saudi Arabia has reported 1,344 new coronavirus cases in the last 24 hours, bringing the total number of infections in the country to 24,097, the Ministry of Health announced on Friday.

The ministry also announced 7 more deaths and 392 new recoveries, raising the total number of fatalities and recoveries to 169 and 3,55 respectively.

Out of the 1,344 new cases reported today, 282 were confirmed in Riyadh, 237 in Madinah, 207 in Makkah, 171 in Jubail and 124 in Jeddah in addition to 114 infections in Dammam.

Authorities continue to urge people to stay at home unless necessary despite having relaxed some restrictions and curfews at the start of Ramadan.

Citizens and residents are allowed to go out for necessary needs between 9 a.m. and 5 p.m. but must adhere to precautionary measures such as wearing a face mask and maintaining social distancing practices.

The Tawakkalna application developed by Saudi Arabia's National Information Centre to processes requests for movement permits during the curfew to curb the spread of the virus has become a major helplnine for past few weeks. 

The application developed through the close cooperation between the Ministry of Health and the Saudi Data and Artificial Intelligence Authority (SDAIA) was launched on May 4.

According to Saudi Telecom Group, it handles 20,000 calls daily through the Tawakkalna platform by dedicating a call centre of 600 employees through its Contact Centre Company (CCC). 

The Tawakkalna app can be used to issue e-permits for a selected group of government and private sector employees who were exempted from the curfew, and individuals who have medical appointments as well as couriers.

Tawakkalna has features for the service of citizens and residents, for ensuring their safety and comfort that would contribute to facilitating the access of authorized persons to travel permits.

The official page about Tawakkalna on Twitter, says: “You must always keep in mind that pinpointing your exact location of residence is the only way for you to benefit from the app’s range of services and permits.”

The app will also provide the latest alerts and medical news issued by the Ministry of Health about the virus as well as about its spread, ways to prevent it and movement permits.

Tawakkalna can be used for self-disclosure for people who show signs of coronavirus infection and for requesting ambulance service and other important services for the community.

Through the app users can apply for a one-hour permit for a walk in the neighborhood on a daily basis, thereby encouraging walking during this period of lockdown.