Lanka president hits out at committee probing Easter Sunday attacks

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, Jan 11: US President Donald Trump has signed an executive order imposing another set of crippling sanctions against Iran, targeting several of its top leaders, military commanders, and its infrastructure industry, according to a statement from the White House on Friday.

Trump said the executive order authorises the imposition of sanctions against any individual or entity operating in the construction, manufacturing, textiles, or mining sectors of the Iranian economy or anyone assisting those who engage in this sanctioned business.

The sanctions are the latest in a series of retaliatory measures between the two nations.

Iran's powerful military commander Qasem Soleimani was killed last Friday in US drone strikes, ordered by President Trump, bringing the entire Gulf region close to a full-blown conflict.

Regional tensions remained high after Iran on Wednesday fired missiles at two bases in Iraq used by US forces.

"Today, I am holding the Iranian regime responsible for attacks against United States personnel and interests by denying it substantial revenue that may be used to fund and support its nuclear program, missile development, terrorism and terrorist proxy networks, and malign regional influence," said Trump on Friday, after signing the executive order.

"This order will have a major impact on the Iranian economy, authorising powerful secondary sanctions on foreign financial institutions.

"The Iranian regime has threatened United States military service members, diplomats, and civilians, as well as the citizens and interests of our allies and partners, through military force and proxy groups. The United States will continue to counter the Iranian regime's destructive and destabilising behaviour," the president said.

Trump said the economic sanctions will remain till the Iranian regime changes its behaviour.

Earlier at a White House news conference, Treasury Secretary Steven Mnuchin, along with cabinet colleague Secretary of State Mike Pompeo, said the US will continue its economic and diplomatic sanctions on Iran till Tehran announces it will not pursue the nuclear weapons program and stop its destabilising behaviour in the region.

The eight senior Iranian regime officials against whom sanctions have been issued include Ali Shamkhani, the Secretary of Iran's Supreme National Security Council, Mohammad Reza Ashtiani, the Deputy Chief of Staff of Iranian armed forces, and Gholamreza Soleimani, the head of the Basij militia of the Islamic Revolutionary Guards Corps (IRGC).

The sanction on the Iranian officials would mean denial of visa to the US and seizure of assets, among others.

In addition, the treasury designated 17 Iranian metals producers and mining companies, a network of three China-and Seychelles-based entities, and a vessel involved in the purchase, sale, and transfer of Iranian metals products, as well as in the provision of critical metals production components to Iranian metal producers.

"The United States is targeting senior Iranian officials for their involvement and complicity in Tuesday's ballistic missile strikes," Mnuchin said.

"We are also designating Iran's largest metals manufacturers, and imposing sanctions on new sectors of the Iranian economy including construction, manufacturing, and mining. These sanctions will continue until the regime stops the funding of global terrorism and commits to never having nuclear weapons," he added.

Pompeo told reporters that Iran was planning "broad, large-scale attacks" against American interests in the Middle East, including embassies.

The latest round of sanctions are aimed at striking at the heart of Iran's internal security apparatus, he said.

"The president has been very clear: we will continue to apply economic sanctions until Iran stops its terrorist activities and commits that it will never have nuclear weapons," Mnuchin said.

Kuala Lumpur, Feb 4: Malaysia said on Tuesday that India's move to cut back on palm oil purchases is "temporary" and will be resolved amicably between the two nations.

Last month, India restricted imports of refined palm oil and asked importers to avoid purchases from Malaysia after its criticism of actions in Kashmir and a new citizenship law.

"Having long-standing bilateral ties, the two nations will overcome the current challenges, and prevail towards mutual and beneficial outcomes," the Malaysian Palm Oil Council said in a statement, citing Primary Industries Minister Teresa Kok.

Malaysia's push to implement B20 biodiesel starting this month will also help sustain high crude palm oil prices, the statement read.