‘Brother not married, so sister has come’: Amit Shah on Congress ‘dynasty’

New Delhi, Jan 24: Under attack for doling out subsidies, Delhi Chief Minister Arvind Kejriwal on Friday said freebies in limited dose are good for the economy as they make more money available to the poor and boosts demand.

Opposition parties have been attacking the AAP-led Delhi government for giving "freebies" ahead of polls after it announced schemes like free bus rides for women and 200 units of free electricity.

"Freebies, in limited dose, are good for economy. It makes more money available to poor, hence boosts demand. However, it should be done in such limits so that no extra taxes have to be imposed and it does not lead to budget deficits," Kejriwal said in a tweet.

Slamming the BJP, Kejriwal said he is happy that the people of Delhi have forced the Saffron party to ask for votes on the basis of CCTVs, schools and unauthorised colonies.

Reacting to a tweet of the BJP Delhi in which Home Minister Amit Shah had asked how many schools have been constructed and cameras installed by the AAP government, Kejriwal said he is happy that Shah saw some CCTV cameras as earlier he had claimed that he could not find a single one.

"I am happy you saw some CCTV cameras. A few days back you said there was not a single camera. Take out some time we will show you our schools also. I am extremely happy that the people of Delhi have changed the politics by which the BJP has to ask for votes on CCTV, schools and raw colonies here," he said in a tweet.

Responding to Shah's allegation that he could not find WiFi in Delhi as promised by Kejriwal and that his battery drained out in the process, the Delhi chief minister said along with free WiFi they have also made arrangement for free charging points.

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.