No ban on day-dreaming: Javadekar on Rahul's prime ministerial aspirations

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.

Karachi, May 29: Investigators and rescue officials have found around Rs 3 crore in cash in the wreckage of the Pakistan International Airlines' aircraft that crashed wth 99 people on board, killing 97 people, including nine children.

Flight PK-8303 from Lahore to Karachi crashed in a residential area near Karachi International Airport on Friday, with only two passengers miraculously surviving the crash.

Investigators and rescue officials have found currencies of different countries and denominations worth around Rs 30 million from the aircraft's wreckage, an official said on Thursday.

"An investigation has been ordered into how such a huge amount of cash got through airport security and baggage scanners and found its way into the ill-fated flight," the official said.

He said that the amount was recovered from two bags in the wreckage.

"The process of identifying the bodies and their luggage which will be handed over to their families and relatives is going on," he said.

A total of 97 people including the aircraft crew died in the crash, one of the most catastrophic aviation disasters in Pakistan's history.

A government official said on Thursday that the identification of 47 bodies had been completed, while 43 bodies were handed over for burial.

Friday's accident was the first major aircraft crash in Pakistan after December 7, 2016 when a PIA ATR-42 aircraft from Chitral to Islamabad crashed midway. The crash claimed the lives of all 48 passengers and crew, including singer-cum-evangelist Junaid Jamshed.

Singapore, Jun 2: Moody's Investors Service on Tuesday downgraded 11 Indian banks along with as many non-financial companies and infrastructure majors besides four government-related issuers following a downgrade of the Indian government's issuer rating to Baa3 from Baa2 with a negative outlook.

The rapid and widening spread of the coronavirus outbreak, deteriorating global economic outlook, volatile oil prices and asset price declines are creating a severe and extensive credit shock across many sectors, regions and markets, said Moody's.

The Indian banking sector has been affected given the disruptions to India's economic activity from the coronavirus outbreak, which is weakening borrowers' credit profiles, it added.

The 11 lenders include Bank of Baroda, Bank of India, Canara Bank, Central Bank of India, Export-Import Bank of India, HDFC Bank, Indian Overseas Bank, IndusInd Bank, Punjab National Bank, State Bank of India and Union Bank of India.

The 11 non-finance companies are Oil and Natural Gas Corporation, Hindustan Petroleum Corporation, Oil India, Indian Oil Corporation, Bharat Petroleum Corporation, Petronet LNG, Tata Consultancy Services, Infosys, Reliance Industries, UPL Corporation and Genpact.

The 11 infrastructure companies are NTPC, NHPC, National Highways Authority of India, Power Grid Corporation, Gail India, Adani Green Energy Restricted Group (RG-2), Adani Transmission Restricted Group, Adani Ports and Special Economic Zone, Adani Transmission, Adani Electricity Mumbai and Azure Power Solar Energy.

The four Indian government-related issuers are Indian Railway Finance Corporation, Housing and Urban Development Corporation, Power Finance Corporation and REC Ltd.

"Government-related issuers in India have been affected because of disruptions to India's economy which will weaken borrowers' credit profiles," said Moody's.