Hemant Karkare died because I cursed him: Sadhvi Pragya

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.

Lucknow, Jul 2: Senior BJP leader Uma Bharti Thursday appeared in person before a special court here conducting trial in the 1992 Babri mosque demolition case.      

The special CBI court is currently recording the statements of 32 accused under CrPC section 313 (court's power to examine the accused), a stage in the trial that follows the examination of prosecution witnesses.

The 61-year-old saffron clad BJP leader is the 19th accused to depose before the court in the over 27-year-old case. Thirteen other alleged accused, including former deputy prime minister LK Advani and senior BJP leaders MM Joshi and Kalyan Singh are yet to be examined at this stage. Their lawyers have indicated to the CBI court that they prefer to appear through video conferencing. 

The mosque in Ayodhya was demolished in December 1992 by 'kar sevaks' who claimed that an ancient Ram temple had stood on the same site. The CBI court is conducting day-to-day hearings to complete the trial by August 31, as directed by the Supreme Court.

Lucknow, Mar 5: Uttar Pradesh chief minister Yogi Adityanath said last night that the role of teachers would come under the scanner when "anti-India" slogans are raised at universities and institutions of higher education.

"When anti-India slogans are raised at institutions of higher education, we should be prepared to ask why this type of distortion occurrs among our students?" he said at a programme organised by the Basic Shiksha Parishad in Lucknow.

"We begin our work with pledge for the country's unity and integrity and today slogans are raised for the division of the nation. In such a situation, questions are raised over the role of teachers who are considered equal to god in society," he said.

"Who all are involved in this sin and chaos? Governments can provide resources, but the one who has given them basic education, who has given them secondary education and who has led them to that place, all of them should evaluate their actions today," the chief minister said.

Speaking about the condition of education in the state when his government came to power three years ago, he said there was an atmosphere of chaos and anarchy in the state and the condition of basic education was very bad.

"The worst problem was that of proxy teachers. Our government started the process of prohibiting proxy teachers in the first phase," he said.

Adityanath said that a teacher is not just a government servant, but the fate of the nation. He said teachers should learn from Chanakya.

Had Chanakya confined himself to Nalanda University, he would not have been able to make India a superpower of the world during that period. Teachers will have to prepare themselves according to the challenges and need of society, he added.