Heavy rains hit airport operations, many flights affected

Mumbai, Jun 3: With an expected increase in wind conditions up to 120 kilometres, cyclone Nisarga is likely to make landfall on the north coast of Maharashtra later today, as per the Indian Meteorological Department (IMD) on Wednesday.

"Wind conditions will further increase up to 100-110 gusting to 120 kmph as conditions are favourable for intensification. The higher sea surface temperature and low vertical wind shear favoured the intensification of severe cyclonic circulation," said IMD in a series of tweets.

Explaining the nature of wind speed, IMD further tweeted, "Eye diameter is about 65 km as observed through Radar. thus the diameter has decreased during past 01 hours indicating intensification of the system. hence wind speed has increased from 85-95 kmph to 90-100 kmph gusting to 110 kmph."

Several National Disaster Response Force (NDRF) teams have been deployed across Maharashtra to ensure preparedness for the impending cyclone. A total of eight teams have been deployed in Mumbai, five teams in Raigad, two teams in Palghar, Thane, and Ratnagiri and one team in Sindhudurg, said NDRF.

Besides, five NDRF teams were airlifted by IL-76 from Vijaywada for Mumbai on June 2, as per the Indian Air Force (IAF)

"Around 60 per cent of people, from the coastal areas around this area, have gone to their relatives' places. The remaining ones have been sent to the evacuation centre. We have also taken into account the COVID-19 guidelines and ensured social distancing," NDRF officer Shiv Parada Rao, deployed with his team in the Dahanu area, spoke to ANI.

"From the information we have received cyclone Nisarga is likely to hit here by tonight. The exact time is not confirmed yet. We are taking all preparedness measures to tackle the situation," he added.

NDRF teams also conducted evacuation in Alibaug during the early hours on Wednesday morning, as per NDRF Director General SN Pradhan.

As per the 5 am bulletin released by IMD, cyclone Nisarga was heading towards north Maharashtra coast at a speed of 11 kmph. It was about 200 km South -SouthWest of Alibag and about 250 km south-southwest of Mumbai at 2.30 AM today, stated the bulletin.

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.