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May 28: Boeing is cutting more than 12,000 jobs through layoffs and buyouts as the coronavirus pandemic seizes the travel industry, and more cuts are coming.

One of the nation's biggest manufacturers will lay off 6,770 U.S. employees this week, and another 5,520 workers are taking buyout offers to leave voluntarily in the coming wee

Air travel within the U.S. tumbled 96% by mid-April, to fewer than 100,000 people on some days. It has recovered slightly. The Transportation Security Administration said it screened 264,843 people at airports on Tuesday, a drop of 89% compared with the same Tuesday a year ago.

Boeing had said it would cut 10% of a work force that numbered about 160,000. A Boeing spokesperson said Wednesday's actions represent the largest number of job cuts, but several thousand additional jobs will be eliminated in the next few months.

The layoffs are expected to be concentrated in the Seattle area, home to Boeing's commercial-airplanes business. The defense and space division is stable and will help blunt the impact of the decline in air travel and demand for passenger jets, the company said.

Boeing said additional job cuts will be made in international locations, but it did not specify numbers.

"The COVID-19 pandemic's devastating impact on the airline industry means a deep cut in the number of commercial jets and services our customers will need over the next few years, which in turn means fewer jobs on our lines and in our offices," CEO David Calhoun said Wednesday in a memo to employees.

Calhoun said the company faces the challenges of keeping employees safe and working with suppliers and airlines "to assure the traveling public that it can fly safe from infection."

Calhoun warned that Boeing will have to adjust business plans constantly because the pandemic makes it hard to predict the impact on the company's business.

Boeing's crisis began with two crashes of its 737 Max, which led regulators around the world to ground the jetliner last year. The company's problems have deepened with the coronavirus, which has cut global air traffic by up to 90% and caused airlines to postpone or cancel orders and deliveries for new planes.

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.

Washington, May 20: The United States recorded another 1,536 coronavirus deaths over the past 24 hours, the Johns Hopkins University tracker said.

That figure, tallied as of 8:30 pm (0030 GMT), raises to 91,845 the total number of COVID-19 deaths in the US.

The US tops the global rankings both for the highest death toll and the highest number of infections, with more than 1.5 million cases.