India's tolerance, openness its biggest economic strength: Raghuram Rajan

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 7: As India begins the world’s largest evacuation mission by repatriating its overseas citizens stranded due to COVID-19, as many as 354 of them from the UAE will fly into their home country in the first two flights to Kerala today.

An Air India Express flight, which is scheduled to take off from Abu Dhabi to Kochi at 4.15 pm is the first flight, which will be followed by a Dubai-Kozhikode flight of the same airline at 5.10pm. The Indian missions in the UAE finalised the list of passengers, who were chosen based on the compelling reasons they submitted while registering their names.

Selection criteria

These include pregnant women and their accompanying family members in some instances, people with medical emergencies, workers and housemaids in distress, families with cancelled visas, bereaved family members who couldn’t attend funerals back home, a few students and stranded visitors and tourists including two brothers who got stranded in Dubai International Airport for 50 days, the missions said.

Short-listing the first passengers from among a database of more than 200,000 applicants, who include around 6,500 pregnant women, has been a mammoth task which posed several challenges for the missions, Neeraj Agrawal, Consul Press, Information and Culture at the Indian Consulate in Dubai told Gulf News.

He said the consulate set up an operations room in a tie-up with community volunteers from Kerala Muslim Cultural Centre, Indian Association Ajman, AKCAF Task Force, the BAPS Mandir, Indian People’s Forum, and Tamil Ladies’ Sangam.

 “We are trying to accommodate as many deserving people as possible. We expect the understanding of the people. It has been very difficult to sort out everyone’s urgency.”

“We cannot do a lottery system in this and we had to make sub- categories to ensure there is a mix of people with different types of urgencies.”

“Though we want to give priority to pregnant women, it is practically not possible and not good for the health and safety of the applicants to allot a lot of them on the same flight.”

He said 11 pregnant women have been issued tickets on the Dubai-Kozhikode flight.

“That is the threshold we can allow on a flight.”

Volunteer support

The consul appreciated the support of the volunteers in finalising the flight manifest.

“But our response ratio was very less. Many people whose names came up on top of the list were not willing to go on the first flights.”

Due to various constraints like this and sometimes the details of accompanying persons not readily being available, he said the mission was not able to quickly reach out to who might be really in need.

“However, we have given due consideration to people who got in touch with us with their emergency needs. At the time of issuing tickets, we had about 20 such cases.”

He said the Consul General of India in Dubai Vipul led the entire operation and Pankaj Bodkhe, consul, education, was in charge of the Dubai flight.

A big challenge

“It has been a big challenge. Our only concern is that despite our best efforts, sometimes people with more compelling reasons might have got left out on the first flights because of the volume of people who have reached out to us.”

Since there is a chance that some passengers with tickets might not be allowed to fly if they fail the medical screening including blood tests to check antibodies for COVID-19, he said some applicants in the waiting list have been asked to be on standby at the airport.

People with emergencies wishing to fly to other destinations also could not be included, he pointed out.

“We had to ask them to wait. We are unable to send them to other destinations. We can see their desperation. We feel sorry and desperate.”

He said the government is trying to add more flights to un-chartered destinations and a new flight from Dubai to Kannur has been added on May 12.

Passengers of today’s flights have been urged to reach the airport four to five hours prior to departure to facilitate the medical screening.

New Delhi, Feb 18: A Delhi court today sent Sharjeel Imam, who has been named as an "instigator" by the Delhi Police in its chargesheet on violent protests against the amended citizenship act at New Friends Colony near Jamia in Delhi last year, to judicial custody till March 3.

Sharjeel Imam was arrested on sedition charges last month.

The Delhi Police has filed a chargesheet before Chief Metropolitan Magistrate Gurmohina Kaur, naming Sharjeel Imam as an instigator of the violence.

It said it has attached CCTV footage, call detail records and statements of over 100 witnesses as evidence in the chargesheet.

The court had on Monday sent Sharjeel Imam to one-day custody of Delhi Police in the case.

Protestors had torched four public buses and two police vehicles as they clashed with police in New Friends Colony near Jamia Millia Islamia in Delhi during the demonstration against the CAA on December 15, leaving nearly 60 people including students, cops and fire fighters injured.