Thursday, May 21, 2020

Mask and face shield adventures

addendum 230713


addendum 230608



addendum 210515
EBY overtaking Stark as my favorite mask



addendum 210501
Stark v EBY v Wicking Neck Gaiter


Addendum 210424
Proper Cloth

Addendum 210401
Honeywell v Stark mask



Addendum 210129
Winter PPE:







Addendum: 200814

I am very irritated about the way the press is treating the findings regarding wicking neck gaiters putting off droplets.  People: DROPLETS ARE NOT VIRUSES.   Wicking neck gaiters put of a lot of droplets by evaporation.  Droplets produced by evaporation are usually sterile.  The large numbers of droplets are not an indication that these masks are dangerous.  Quite the contrary: they may be much safer than other cloth masks.

Also, I am concerned about the condemnation of vented masks.  The vents on these masks direct droplets downwards.  They are going to have almost zero horizontal velocity.  This means that any exhaled viruses are likely to end up on the chest of the wearers, not in the air.  i am frustrated that the research is not looking at the role of horizontal velocity in the effectiveness of masks that are imperfect filters.


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Here is an instagram video of me with my shop towel mask.


I got the SDS (safety data sheet) for the shop towels that I used and I didn't see anything dangerous on there, but they still give me a sore throat, so I don't like them. They were tested by someone at the University of North Carolina and they supposedly functioned better than standard surgical masks.  I did find that they fit my face well and didn't seem to have gaps around the edges.  I also found that I could breath fairly well through them.

I also tried the double towel mask, which is supposedly even more effective, but I found that I couldn't breathe well through it, which the video that talked about it warned about.

The following is a video about a plastic face shield that I ordered off of an instagram ad.  This was a dud.



Observations about soft plastic face shields


This is a video about a home made face mask that I got from a friend.


I've become convinced that the eyes are probably the primary way that COVID-19 would enter the body.

The mouth contains saliva, which is acid, and then you swallow a lot, which takes things down to the stomach, which is even more acid.  I've seen doctors claiming that the SARS-COV2 does not survive stomach acid.

The nose is pointing downwards, so, while you might inhale viruses, they won't normally just go flying in there.

The eyes, on the other hand, are just sitting right there in the front of your face where anything can fly in.  So I tried buying some prescription swim goggles, with the thought that they might be good for keeping viruses out of eyes.  These are the ones I ordered

https://www.swimoutlet.com/p/sporti-antifog-s2-optical-goggle-22598/?color=29563

They came quickly.  Given the very low price, I was astounded that I really could see very well.  They aren't as sophisticated as the glasses you pay more for.  They don't have astigmatism correction.  They don't account for pupilary distance, but for eight bucks they're pretty amazing.  If you can't afford glasses, you might try this.  Here's a photo of me with them on


I do find though that they're not really comfortable enough to wear all day.  They make my mug look oval, though, again, for the price, not so bad.  There was a weird adjustment going back to my regular glasses after wearing them.

Another issue that they have is that the plastic strap is sort of staticky and is a definite hair tangling hazard.  I accidentally pulled out a hunk of hair with them when I took them off. They probably work best over a swim cap.

If I ever dare go swimming again, I'm definitely going to use them.  I do think that germs travel pretty fast in water, so I don't think that swimming is going to be a good option this summer.  Still, as I said, for eight buck these have optical correction, UV protection, and anti-fog coating, which makes them pretty amazing to me -- and, since they are water tight, and definitely seal to my face, I do suspect they would keep virions out of my eyes.

Here's one about a face shield that I like


This is where I got this on amazon

https://www.amazon.com/gp/product/B0882XZN5G/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I'm going to post more instagram videos soon about my adventures.

This is a video about putting buttons on your glasses to hang masks from.  I'm putting the link here just in case I want to find it again

https://www.gif-fcv.com/reactions/gif/778/life-hax


This is about copper alloy devices for pushing buttons and opening doors



This video shows me with a turtle neck style mask with cooling, wicking material:




Athletic mask with vents.  Are vents anti-social?

The problem is that many people end up pulling their masks off their noses, even indoors, because they're having problems breathing.  The vents do improve the air quality inside the mask.  I feel that viruses escaping from the vents will still have lower horizontal velocity than if you had no mask, especially if the vents are pointed downwards as these are.  Moreover, most of your exhalation is going forward, not out the vents.  With reduced horizontal velocity, the viruses, or respiratory droplets containing them, will fall to the floor sooner.

I think the move to make the vents illegal is short sighted. A mask with vents is better than someone who pulls their mask off their nose, because they can't breathe.

I ended up not liking this mask too much, because if fogged up my glasses more than other masks.  Also it was hard to put on.







This is a "space mask" with nanofibers.  One concern I have with nanofibers is that they are fairly new and I'm not sure what their structural integrity is. Do they break off? If they break off, do I inhale them? If I inhale them, is that going to injure my lungs? 

Initially, I only felt slight irritation after wearing the Space Mask; however, after washing it, I noticed that it made my lips tingle, so I didn't want to wear it any more.  I was thinking that possibly the nanofibers might end up being a bit like asbestos.






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I bought this lovely butterfly mask on impulse, when I already had plenty of masks, but I really like it. I later realized that the reason that the shield was milky was that I had neglected to remove the protective cover.





This one is a more convenient substitute for a bandana.


So, here is me trying to "fix" PPE that has issues.


interesting youtube video testing masks


my comments on this youtube video


I was a physics major. I've been interested in reading the research of Dr. Lydia Bourouiba at MIT on the topic of the flight of respiratory droplets. Her models predict that, with intense breathing, respiratory droplets from the lungs could travel up to 27 feet. This is due to starting out with a horizontal velocity of 30-50 mph. It seems to me that our goal with cloth masks is not to create a sterile environment where there are no viruses. The goal should be to reduce the number of respiratory droplets AND to reduce their horizontal velocity. If they have no horizontal velocity, they will fall to the floor more quickly. In this video, you don't distinguish fog that has a high initial horizontal velocity from fog that has a low initial horizontal velocity. It seems to me that fog that is moving downward, e.g. from a mask with vents, is mostly going to land on the user's chest or the ground -- not out in the room where other people will inhale it. The situation with COVID-19 precautions is quite different from an operating room, where the surgeon is bending over the open body cavity of a patient. In the surgery situation, a few leaks could be very serious. In the common every day social situation, a few leaks, if of low horizontal velocity, are not going to be as important. I wish I would see more discussion of this aspect of the aerodynamics of contagion

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 Here's another episode in my ongoing experiments with PPE. I should say that I don't really think this setup would be adequate to go into a store -- but for hiking outside it's ok

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Addendum 210321 -- EBY mask




 

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Wednesday, April 29, 2020

Some more recent selfies

Interestingly, despite the lockdown, I've been getting a fair number of video auditions.  I even booked a virtual gig.  I decided to take some stills from those videos, to show my new COVID hair. I'm putting my favorite on top.













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Friday, April 24, 2020

Why is a virus innocent until proven guilty?

Here is the text of some e-mails that I just sent.

To my college roommate who is an oncologist:

I hope you won't mind me asking you a question.

This pandemic has gotten me interested in the mechanics of viral transmission. I've been reading with great interest about the research of Lydia Bourouiba at MIT.  She has demonstrated with mathematical models, in peer reviewed research, that respiratory droplets travel much further than 6 feet, yet Anthony Fauci refuses to believe her -- when he's not a mechanical engineer.

In looking at the papers on viral transmission, there seems to be an assumption that viruses are not transmissible by aerosol until proven to be transmissible.  In the law, we would call this "innocent until proven guilty."  That's what we would call an issue of "burden of proof." Who has the burden of proving someone or something guilty? In the law, the burden is on the plaintiff or the prosecutor to prove the defendant guilty.

But why do we give the virus the benefit of the doubt? It seems to me, looking at news stories, that this assumption has gotten people in a lot of trouble both with Ebola and with this latest novel coronavirus.  Medical personnel went in with inadequate PPE and got sick... until they were in hazmat suits.

Why don't we assume that the virus is capable of aerosol transmission and even of penetrating the skin, until the virus is proven innocent?  The virus is not a human being with constitutional rights.  Why not guilty until proven innocent?

To the chair of the physics department of Dartmouth College

I got your name off the Dartmouth website as chair of the physics department.
I am an alum.  I majored in physics.  I was a TA in pre-med physics.   I have a question about the mechanics curriculum.
When I was in freshman physics, I remember quite vividly using a little spring loaded device that shot a steel ball.  We stopped the ball at several points and demonstrated that its arc of flight was a parabola.
I think we had the pre-med physics class doing that same experiment.

We didn't, as I recall, get into the mechanics of flight -- or aerodynamics.  That was deemed too complex, I believe, for pre-meds, who would struggle with the idea of a parabola.
Now, I'm seeing what I think are bad consequences of this curriculum decision.  Doctors assume that a round object, like a coronavirus, will fall like the steel ball within 6 feet. When Lydia Bourouiba of MIT does fluid mechanical modeling and demonstrates in a peer reviewed paper that respiratory droplets can travel up to  27 feet, due to turbulent flow, Anthony Fauci does not believe her.
To me, looking at the images of the coronavirus, given it's size and weight, it seems fairly clear that the little projections would make it capable of flight, like dandelion fluff -- at least for a while, until it dries up.   It's small and light, so it would not require big wings like a helicopter or an airplane, and not even as big of tendrils as dandelion fluff.

Yet doctors don't think that way.  They remember the steel ball falling along the parabola. They've made assumptions about the behavior of viruses in air that are unjustified, given fluid mechanics. They've repeatedly sent medical personnel into harm's way with inadequate PPE and those personnel have died as a result -- both in the Ebola situation and the COVID-19 situation.j



I am concluding that the pre-med physics curriculum needs to be drastically revised.  It is unlikely that a doctor would need to calculate the trajectory of a cannon ball, unlike Isaac Newton. It is much more likely that they would need to calculate the trajectory of something that can be blown about in air currents. 
To my sister-in-law who has a Ph.D. in mechanical engineering from CalTech.  This was a cover letter to forwarding the e-mail immediately above.

I am forwarding to you a copy of an e-mail that I just sent to the chair of the physics department at Dartmouth, where I went to college, about the curriculum of pre-med physics.
I'm remembering an interchange you and I had back when I was doing natural childbirth.  At that time, obstetricians were still doing episiotomies. This was a procedure where they would cut the tissue around the vagina during childbirth, on the belief that this would reduce tearing, or make tears easier to repair.
 It was your opinion, at the time, that this procedure was unjustified in view of mechanical engineering principles -- that the procedure would make tears worse, not better. I'm noticing that now, 30 years later, episiotomies have finally been discredited, though some doctors *still* do them.
I'm seeing something similar in the medical literature that I'm seeing about the transmission of coronavirus. They're making assumptions based on faulty understanding of fluid mechanics. 
I'm wondering if you've been following the research of Lydia Bourouiba at MIT -- and her modelling of the mechanics of flight of respiratory droplets -- and the rejection by Anthony Fauci of her conclusions.
I'm proposing to the chair of the physics department at Dartmouth that the curriculum of pre-med physics needs to be drastically revised.


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Here's another example of the virus being presumed innocent until proven guilty. This is in the question of whether pets can transmit the virus to humans.

 https://now.tufts.edu/articles/can-pets-get-or-spread-covid-19

Despite the fact that the virus is believed to have jumped from animals to humans in the first place, and the fact that infection in animals from humans has been documented, people don't believe the virus could still jump from animals to humans, because there is "no evidence."
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Thursday, April 9, 2020

Fluid Dynamics and virus transmission

Here are some articles that I want to remember

https://www.usatoday.com/story/news/health/2020/03/30/coronavirus-social-distancing-mit-researcher-lydia-bourouiba-27-feet/5091526002/

Bourouiba models exhalation gas clouds and finds that they can travel up to 27 feet.  The CDC poo-poos this and says it's misleading.

In a Journal of the American Medical Association article published last week, Bourouiba said peak exhalation speeds can reach 33 to 100 feet per second and "currently used surgical and N95 masks are not tested for these potential characteristics of respiratory emissions."

 Pottinger says that if the virus were effective at 27 feet more people would be sick. But we don't know how many people are sick. There are so many who are not being tested. This is a specious argument.

https://www.propublica.org/article/what-we-need-to-understand-about-asymptomatic-carriers-if-were-going-to-beat-coronavirus?fbclid=IwAR26XkDAb_EfR-SPnlu-v2_ilBD_05JzuxtRlupaat6fB4ccubCy-LLghJ4

https://medium.com/@jurgenthoelen/belgian-dutch-study-why-in-times-of-covid-19-you-can-not-walk-run-bike-close-to-each-other-a5df19c77d08

https://cee.mit.edu/people_individual/lydia-bourouiba/

Lindsey Marr https://www.nytimes.com/2020/06/12/well/live/Coronavirus-aerosols-linsey-marr.html

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Statement by one interlocutor

The Media has done exactly what it intended to do invoke FEAR in everyone.. I advise everyone to do your own research on the subject of viruses... this virus is not AIRBORNE!! Additionally, for those of you who think the masks are a shield here is another tidbit the size of the virus is so small it can easily goes through these masks... nothing other than a hazmat suit will protect you. Again, that is if its airborne.
I suggest that you ask our
Heavenly Father to give you clarity on this. I assure you He will.
For God has not given us the spirit of Fear but of power, and of love and of a sound mind
Timothy 1:7
Believe & Receive!

My response

There is an issue of wording here.  This virus is larger and heavier than, say, the measles virus.   The measles virus is considered "airborne" in the sense that it can rise, unaided, into the air and move freely about.

This virus is heavier than air and tends to want to fall on the ground.  It is believed to travel on respiratory droplets, not to be independently airborne, unlike the measles virus.

However, how far respiratory droplets can travel, how long they can stay airborne, and how far a virus can be effective on such a droplet is still a matter of active research.

This peer-reviewed study cosponsored by several prominent research institution found that the virus could be effective in the air on respiratory droplets for three hours.

https://www.nejm.org/doi/full/10.1056/NEJMc2004973

However, Lydia Bourouiba, an MIT researcher in fluid dynamics, has found that respiratory droplets can travel up to 27 feet. Fauci, who works for the CDC, which you so distrust, discounts this research as misleading, because he doesn't believe that the virus could be effective on droplets that travel so far.

https://www.usatoday.com/story/news/health/2020/03/30/coronavirus-social-distancing-mit-researcher-lydia-bourouiba-27-feet/5091526002/

In fact, the CDC and the WHO are conservative about how far the virus can travel in air.  Many researchers think it can go farther than what they say, as in the article that I cited above.

In the USA Today article, Pottinger is cited as saying that if the virus were effective at 27 feet more people would be sick.  But we don't know how many people are sick.  There are so many who are not being tested.  This is a specious argument.

Also, because the virus travels on droplets, which are larger than the virus -- its travel, upon exiting the mouth and nose, is limited. The masks are not to protect the wearer. The masks are to protect others.

*****

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