Extremists taking advantage of global lockdown to recruit youths online: UN chief

Dubai, Jan 8: A Ukrainian airliner crashed soon after taking off from Tehran's Imam Khomeini airport on Wednesday, killing all 176 people aboard, Iran's state television and Ukraine's leaders said.

The Boeing 737 belonging to Ukraine International Airlines crashed near the airport and burst into flames. Ukraine's embassy in Iran, citing preliminary information, said the plane had suffered engine failure and the crash was not caused by "terrorism".

Ukraine President Volodymyr Zelenskiy said there were no survivors.

"My sincere condolences to the relatives and friends of all passengers and crew," Zelenskiy said in a statement, adding that Ukraine was seeking to establish the circumstances of the crash and the death toll.

Iranian TV said the crash was due to technical problems but did not elaborate. State broadcaster IRIB said on its website that one of the plane's two black boxes - the flight data recorder and the cockpit voice recorder - had been found.

Iranian media quoted an Iranian aviation official as saying the pilot of the airliner did not declare an emergency.

There was no official word from Ukraine International Airlines. It was the Kiev-based airline's first fatal crash.

"The fire is so heavy that we cannot (do) any rescue... we have 22 ambulances, four bus ambulances and a helicopter at the site," Pirhossein Koulivand, head of Iran's emergency services, told Iranian state television.

Ukraine's prime minister and Iranian state TV said 167 passengers and 9 crew were on board. Iranian TV said 32 of those on board were foreigners.

Television footage showed debris and smouldering engine parts strewn across a field, and rescue workers with face masks retrieving bodies of the victims.

According to air tracking service FlightRadar24, the plane that crashed was Flight PS 752 and was flying to Kiev. The plane was three years old and was a Boeing 737-800NG, it said.

The model's twin engines are made by CFM International, a U.S.-French venture co-owned by General Electric and France's Safran.

Modern aircraft are designed and certified to cope with an engine failure shortly after take-off and to fly for extended periods on one engine. However, an uncontained engine failure releasing shrapnel can cause damage to other aircraft systems.

A spokesman for Boeing said the company was aware of media reports of a plane crash in Iran and was gathering more information. The plane manufacturer grounded its 737 MAX fleet in March after two crashes that killed 346 people.

The 737-800 is one of the world's most-flown models with a good safety record and which does not have the software feature implicated in crashes of the 737 MAX.

Under international rules overseen by the United Nations, Iran is responsible for leading the crash investigation.

Ukraine would be involved and the United States would usually be accredited as the country where the Boeing jet was designed and built. France, where the engine maker CFM has half its activities, may also be involved.

There was no immediate word on whether the U.S. National Transportation Safety Board would be involved in the probe amid escalating tensions between the U.S. and Iran. The NTSB usually invites Boeing to give technical advice in such investigations.

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.

Beijing, Feb 9: After making sure everyone's face mask is on and sanitizer is to hand, the Qiao family heads out to Jingshan Park, a former royal sanctuary beside the Forbidden City in China's capital Beijing.

Snow has fallen for a second day, a rare event in the city of 21.5 million that would normally bring hundreds of thousands of people out to take photos and play. But the streets are empty and the parks are so quiet the only sound is of birds chirping.

It's not just Beijing. Shanghai, China's financial hub, and other cities in the world's most populous nation have turned into ghost towns after the government extended a holiday and asked residents not to go out because of the coronavirus.

"We know the situation of the coronavirus is severe. But the epicentre is far away, so we think it should be fine here ... It's a God-given chance to enjoy this family moment with snow and without work," said Mr Qiao, who has an 11-year-old daughter.

The epidemic has killed 722 people and infected nearly 32,000 in China as of February 8. More than three-quarters of the cases are in the central Hubei province where the virus originated - more than 1,000 km (620 miles) from Beijing.

Only a few people are brave enough to come out. A security guard at Jingshan Park said there were less than a third of the number of tourists than usual, even with the rare snowfall.

Even at one of the best spots for snapping photos of snowy Beijing just outside the Forbidden City, there's barely a crowd, while the usual tour buses and groups of people speaking different dialects are nowhere to be seen.

"Last year when it snowed, I took a few hours off work to come down here to take a picture and the crowd was several layers deep," said a man in his 30s who gave his surname as Yang. "But this year, I am not at all worried about finding a space to take a photo. The virus is keeping people indoors."

Security guards along Wangfujing street, a popular pedestrianised shopping area in downtown Beijing, said it was normally so crowded during the holiday period that it was hard to move around.

"Look at it now, there are more security guards and street cleaners than tourists!" said one of the guards.

Businesses, including shops, bars and restaurants, have been severely hit by the epidemic as the government has banned mass gatherings and even group meals in an effort to curb the spread of the coronavirus.

"You would have to wait outside for a table on a normal day," said a waitress at a restaurant with more than 50 tables. Just five were taken at the peak lunch hour.

Only a handful of the more than 100 restaurants along Beijing's famous food street, Guijie, were open, and the remaining outlets were wondering how long they can hold out.