‘Unfortunately, couldn’t see sun’: PM blames clouds for missing solar eclipse

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.

New Delhi, Jan 2: Thirteen firefighters were among the 14 people injured when a battery factory collapsed in northwest Delhi's Peera Garhi following an explosion due to a fire that broke out early on Thursday morning, officials said.

A fire brigade personnel still remained trapped under the debris of the building in Udyog Nagar area, an official said.

A large portion of the two-storey building collapsed following an explosion when firefighters were dousing the blaze, the official said, adding that fire department had received a call at 4.23am.

Plumes of smoke billowed out from the building as the fire brigade personnel battled to contain the blaze. An eyewitness said several explosions were heard as the blaze gutted down the building.

The National Disaster Response Force (NDRF) and civil authorities rushed to the spot to control the situation, an official said, adding that 35 fire tenders were at the spot.

The injured, including a security guard of the factory, were rushed to nearby hospitals, a police officer said.

Chief Minister Arvind Kejriwal said he was monitoring the situation.

"V sad to hear this. Am closely monitoring the situation. Fire personnel trying their best. Praying for the safety of those trapped," Kejriwal tweeted.

Lucknow, Feb 2: In an early morning firing at Lucknow's Hazratganj, the city centre, Vishva Hindu Mahasabha state president Ranjit Bachchan was killed while he was out on a morning walk on Sunday.

Ranjit Bachchan was taking a stroll in Hazratganj in the morning when bike-borne assailants opened fire on him and killed him on the spot. The Mahasabha leader was shot in the head multiple times.

The incident took place near the CDRI building in Lucknow's Hazratganj.

In the firing, Ranjit Bachchan's brother also suffered bullet injuries. He has been rushed to the trauma centre. Ranjit Bachchan was a resident of Gorakhpur.

The early morning shootout in the Uttar Pradesh capital's central area has caused tension in the area.

Dinesh Singh, DCP Central Lucknow, said, "The body has been identified as of Ranjit Bachchan, who had gone out on morning walk when some unknown assailant shot him. A police team has been formed and further investigation is being carried out."

Before being associated with the Mahasabha, Ranjit Bachchan was a Samajwadi Party member and was often spotted with former UP chief minister Akhilesh Yadav.

The Samajwadi Party has hit out at the Yogi Adityanath government over the law and order situation in the state and demanded immediate resignation of the government.