Trump to reveal Iran deal's fate amid low hopes for survival

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, June 30: China said on Tuesday it was concerned about India’s decision to ban Chinese mobile apps such as Bytedance’s TikTok and Tencent’s WeChat and was making checks to verify the situation.

Chinese foreign ministry spokesman Zhao Lijian told reporters during a daily briefing that (the Prime Minister Narendra Modi-led government of) India has a responsibility to uphold the rights of Chinese businesses.

India on Monday banned 59, mostly Chinese, mobile apps in its strongest move yet targeting China in the online space since a border crisis erupted between the two countries this month.

The apps are “prejudicial to the sovereignty and integrity of India, the defence of India, the security of state and public order", the ministry of information technology said in a statement, which came two weeks after 20 Indian Army personnel were killed in a violent clash on the India-China border in Ladakh.

The companies have been invited to offer clarifications before a government panel, which will decide whether the ban can be removed or will stay.

The move also came ahead of military and diplomatic talks between India and China scheduled this week.

Karachi, May 25: The pilot of the Pakistan International Airlines (PIA)'s crashed plane ignored three warnings from the air traffic controllers about the aircraft's altitude and speed before the landing, saying he was satisfied and would handle the situation, according to a report on Monday.

The national flag carrier's PK-8303 tragedy on Friday, in which 97 people were killed and two miraculously survived, is one of the most catastrophic aviation disasters in the country's history.

The Airbus A-320 from Lahore to Karachi was 15 nautical miles from the Jinnah International Airport, flying at an altitude of 10,000 feet above the ground instead of 7,000 when the Air Traffic Control (ATC) issued its first warning to lower the plane's altitude, Geo News quoted an ATC report as saying.

Instead of lowering the altitude, the pilot responded by saying that he was satisfied. When only 10 nautical miles were left till the airport, the plane was at an altitude of 7,000 feet instead of 3,000 feet, it said.

The ATC issued a second warning to the pilot to lower the plane's altitude. However, the pilot responded again by stating that he was satisfied and would handle the situation, saying he was ready for landing, the report said.

The report said that the plane had enough fuel to fly for two hours and 34 minutes, while its total flying time was recorded at one hour and 33 minutes.

Pakistani investigators are trying to find out if the crash is attributable to a pilot error or a technical glitch.

According to a report prepared by the country's Civil Aviation Authority (CAA), the plane's engines had scraped the runway thrice on the pilot's first attempt to land, causing friction and sparks recorded by the experts.

When the aircraft scraped the ground on the first failed attempt at landing, the engine's oil tank and fuel pump may have been damaged and started to leak, preventing the pilot from achieving the required thrust and speed to raise the aircraft to safety, the report said.

The pilot made a decision "on his own" to undertake a "go-around" after he failed to land the first time. It was only during the go-around that the ATC was informed that landing gear was not deploying, it said.

"The pilot was directed by the air traffic controller to take the aircraft to 3,000 feet, but he managed only 1,800. When the cockpit was reminded to go for the 3,000 feet level, the first officer said 'we are trying'," the report said.

Experts said that the failure to achieve the directed height indicates that the engines were not responding. The aircraft, thereafter, tilted and crashed suddenly.

The flight crashed at the Jinnah Garden area near Model Colony in Malir on Friday afternoon, minutes before its landing in Karachi's Jinnah International Airport. Eleven people on the ground were injured.

The probe team, headed by Air Commodore Muhammad Usman Ghani, President of the Aircraft Accident and Investigation Board, is expected to submit a full report in about three months.

According to the PIA's engineering and maintenance department, the last check of the plane was done on March 21 this year and it had flown from Muscat to Lahore a day before the crash.

In the wake of the COVID-19 pandemic, the Pakistan government had allowed the limited domestic flight operations from five major airports - Islamabad, Karachi, Lahore, Peshawar and Quetta - from May 16.

After the plane tragedy, the PIA has called off its domestic operation.