اینستاگرام

https://www.instagram.com/zabansepahan

https://www.instagram.com/sepahankids
sepahankids@

Do face shields work against Covid_19

موسسه شیخ صدوق س÷اهان

Face shields are becoming an increasingly common sight as lockdown eases,
particularly as people head back to work.

In hairdressers, barbers and beauty salons, where employees come into close contact with customers, workers have been urged to wear extra protection such as clear visors that cover the face – especially if physical distancing isn’t possible. 
A face shield “provides a barrier between the wearer and the client from respiratory droplets caused by sneezing, coughing or speaking,”  
On their own, face shields can help protect the wearer from a cough or sneeze a short distance away – essentially, it stops droplets landing on your face or being inhaled through your nose or mouth. But studies have found smaller aerosols can travel up and underneath the shield.
This is particularly important as the World Health Organization (WHO) has said it cannot rule out the possibility that Covid-19 may be airborne.
A study of  found wearing a face shield reduced exposure to flu by 96% in the period immediately after a cough – from 18 inches away. But in the context of a smaller cough aerosol, the face shield was less effective, blocking only 68% of the cough.
In the half an hour period after a cough, during which the aerosol had dispersed throughout the room and larger particles had settled, the face shield was even less effective, the study found – with researchers concluding that people wearing face shields can still inhale infectious airborne particles.
 
“They cannot be used as a substitute for respiratory protection when it is needed,” researchers concluded of face shields.
 
But what about in a public setting? Dr Julian Tang, honorary associate professor in respiratory sciences at the University of Leicester, tells HuffPost UK that face shields are “better than nothing”.
He is not alone in recommending wearing a shield and face mask together for “added protection”.
Face shields and visors have the added advantage that they include eye protection, says Dr Tang. This is important as there’s potential for the virus to enter the body through mucous membranes in the eyes.
Related...
Shields are also washable and re-useable, and less claustrophobic than masks, he adds, while also allowing for normal communication if worn instead of a face mask – concerns have been raised that opaque face masks and covers make lip-reading impossible for those who rely on it to communicate.
To work best, face shields should fit certain criteria, he says, including:
– Curving around the sides of the face to the ears to reduce aerosols entering from the sides.
– Extending down long enough in front of the face to reduce aerosols from entering underneath the shield.
– Having a tight seal between the top of the face shield and the forehead to reduce the number of aerosols entering from above.
Jennifer Veltman, chief of infectious diseases at Loma Linda University Health in California, could be useful for people who cannot wear masks, but notes that masks remain the number one form of protection.
تکنیک‌ های افزایش انگیزه‌ در یادگیری زبان


uese the social media in English Language

اصطلاح هفته




Clear the air
برطرف کردن سوء تفاهم
سخن روز
Life shrinks or expands in proportion to one’s courage. کوتاهی یا بزرگی زندگی هر کس به نسبت شجاعت اوست.