Never ever visited any rowdy’s home; will retire from politics if allegations proven: UT Khader

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, Feb 18: India emerged as the world's fifth-largest economy by overtaking the UK and France in 2019, says a report.

A US-based think tank World Population Review in its report said that India is developing into an open-market economy from its previous autarkic policies.

"India's economy is the fifth-largest in the world with a GDP of $2.94 trillion, overtaking the UK and France in 2019 to take the fifth spot," it said.

The size of the UK economy is $2.83 trillion and that of France is $2.71 trillion.

The report further said that in purchasing power parity (PPP) terms, India's GDP (PPP) is $10.51 trillion, exceeding that of Japan and Germany. Due to India's high population, India's GDP per capita is $2,170 (for comparison, the US is $62,794).

India's real GDP growth, however, it said is expected to weaken for the third straight year from 7.5 per cent to 5 per cent.

The report observed that India's economic liberalisation began in the early 1990s and included industrial deregulation, reduced control on foreign trade and investment, and privatisation of state-owned enterprises.

"These measures have helped India accelerate economic growth," it said.

India's service sector is the fast-growing sector in the world accounting for 60 per cent of the economy and 28 per of employment, the report said, adding that manufacturing and agriculture are two other significant sectors of the economy.

The US-based World Population Review is an independent organisation without any political affiliations.

New Delhi, Mar 23: The total number of COVID-19 cases in the country rose to 390 on Monday after 30 fresh cases were reported.

The figure includes 41 foreign nationals and the seven deaths reported so far.

Gujarat, Bihar and Maharahstra reported a death each on Sunday, while four fatalities were reported earlier from Karnataka, Delhi, Maharashtra and Punjab, the Union Health Ministry said.

The total number of active COVID-19 cases across the country now stands at 359, while 24 people have been cured/discharged/migrated.