[ARC5] AB5S Kung Flu Update, 13 June - source?

Sun Jun 14 16:36:45 EDT 2020

And as a member of a community symphony orchestra, what he said - in 
spades!  Those pesky woodwinds and brass in the back rows...yow! :-)

I've been able to do some chamber work with 2-3 other string players 
outside in masks on a nice day, but it's hard to blow a trumpet through 
a mask...

- Mike

On 6/14/2020 4:19 PM, Scott Robinson wrote:
> ...and this illustrates why choral singing is unfortunately one of the 
> best ways to make others sick. This is a drag for me, a choral singer 
> the last 63 years.
>
> Stay healthy,
>
> Scott Robinson
>
>> On 6/14/2020 11:54 AM, Michael Hanz wrote:
>>> That pretty much aligns with my view, Scott, with the addition of 
>>> information from an interesting study about aerosols produced by 
>>> simply "normal" talking, reported at 
>>> https://www.nytimes.com/2020/05/14/health/coronavirus-infections.html 
>>> (The National Academy of Sciences detailed report is at 
>>> https://www.pnas.org/content/117/22/11875 ).
>>>
>>> The gist of the article was:
>>> "To see how many droplets are produced during normal conversation, 
>>> researchers at the National Institute of Diabetes and Digestive and 
>>> Kidney Diseases and the University of Pennsylvania, who study the 
>>> kinetics of biological molecules inside the human body, asked 
>>> volunteers to repeat the words “stay healthy” several times. While 
>>> the participants spoke into the open end of a cardboard box, the 
>>> researchers illuminated its inside with green lasers, and tracked 
>>> bursts of droplets produced by the speaker.
>>>
>>> The laser scans showed that about 2,600 small droplets were produced 
>>> _per second_ while talking. When researchers projected the amount 
>>> and size of droplets produced at different volumes based on previous 
>>> studies, they found that speaking louder could generate larger 
>>> droplets, as well as greater quantities of them.
>>>
>>> Although the scientists did not record speech droplets produced by 
>>> people who were sick, previous studies have calculated exactly how 
>>> much coronavirus genetic material can be found in oral fluids in the 
>>> average patient.  Based on this knowledge, the researchers estimated 
>>> that a single minute of loud speaking could generate at least 1,000 
>>> virus-containing droplets."
>>>
>>> Here's a picture of the test setup:
>>>
>>>
>>> That makes it even more than a courtesy to wear a mask, especially 
>>> since most coronavirus spreaders aren't even aware when they are in 
>>> the early stages of their infection.  The cloth masks are indeed not 
>>> perfect, but they are only intended to reduce the frequency of the 
>>> much larger droplets, not the much smaller virus which is attached 
>>> to them.
>>>
>>> - Mike  KC4TOS
>>>
>>>
>>> On 6/14/2020 2:00 PM, Scott Johnson wrote:
>>>> I consider the primary reason for masks, or bandanas, or whatever, 
>>>> not to
>>>> protect yourself, but to protect other from you.  It is a courtesy, 
>>>> if you
>>>> sneeze, cough, or slobber when you talk, it effectively prevents 
>>>> the aerosol
>>>> from going further than the fabric.  Not wearing anything in 
>>>> proximity to
>>>> the public identifies one as  careless and reckless.  If you are in 
>>>> a high
>>>> risk group, and truly worried about your own safety, then you 
>>>> shouldn't be
>>>> exposing yourself needlessly.  I have heard so many opinions, some 
>>>> that are
>>>> diametrically opposed, and all from supposed experts.  Don't care 
>>>> to hear
>>>> any more. Common sense coupled with common decency should prevail.  
>>>> BTW, one
>>>> of my engineers did a CFD model in Solidworks of a sneeze in a room 
>>>> with
>>>> closed loop HVAC.  It propogates and dissipates pretty much like a 
>>>> fart.
>>>>
>>>> Scott V. Johnson W7SVJ
>>>> 5111 E. Sharon Dr.
>>>> Scottsdale, AZ 85254-3636
>>>> H (602) 953-5779
>>>> C (480) 550-2358
>>>> scottjohnson1 at cox.net
>>>> scott.johnson at ieee.org
>>>>
>>>> -----Original Message-----
>>>> From:arc5-bounces at mailman.qth.net <arc5-bounces at mailman.qth.net>  
>>>> On Behalf
>>>> Of Hubert Miller
>>>> Sent: Saturday, June 13, 2020 11:21 PM
>>>> To:arc5 at mailman.qth.net
>>>> Subject: Re: [ARC5] AB5S Kung Flu Update, 13 June - source?
>>>>
>>>> Generally good advice, but I question the non-cough non-sneeze 26 foot
>>>> business, no matter what your doctor said.
>>>> I have read several articles in the New York Times precisely on this
>>>> question, and those articles are well informed, very well informed,
>>>> frequently updated. Ask your doctor his source for his information. 
>>>> I recall
>>>> now they also had an article comparing actual effectiveness of 
>>>> different
>>>> kinds of masks, both homemade and commercial, and gave actual numbers
>>>> compared to N95, and what thickness required even with homemade.
>>>> Also, masks are dry material, so what is your informed reckoning of 
>>>> how long
>>>> virus lives on them ?
>>>> As for health professionals dying despite masks, well, you would 
>>>> have to
>>>> know the extent of their exposure and their full suiting equipment 
>>>> to assign
>>>> this to mask inefficiency.
>>>> Don't forget UV exposure either, to kill virus. These parameters apply
>>>> outside also.
>>>> I found Elderberry anything to be pretty much sold out locally last 
>>>> time I
>>>> shopped, but I'll take another look in the next days.
>>>> -Hue Miller
>>>>
>>>>
>>>>
>>>>
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>>>
>>> -- 
>>> Michael Hanz - KC4TOS
>>>
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-- 
Michael Hanz - KC4TOS