Smoke as a Test Medium

But does the body shed the same number of virus particles that a cigarette spreads when it burns? As those particles spread, the density drops as well.

Which is why we have this totally arbitrary 6-ft 'safe' bubble. Maybe not totally arbitrary. It's probably large enough to have some benefit, but not be so large as to make life totally impossible. Although some states believed it was better to make people's lives impossible, than to risk infections.

We will argue for years whether the cure was worse than the disease.

Talking about this in another thread... I was wondering if a dialysis machine could be used to treat COVID-19... I was thinking of the problems...

1. Thinning of the blood to a point to filter out COVID
2. where does COVID actually resides in the body

so I did a quick search, and it was/is being looked into.

interesting what’s being tried...

I would expect the extreme difference in particulate temperature that makes smoke to rise will give a false indication of dispersion paths.

Still, using cigarette (vaping?) smoke to identify a particular mask effectiveness sounds like a good, frugal idea to me.

The Electrostatic Precipitator of death...or common smoke eater...

https://plasma-clean.com/technologies/electrostatic-precipitation/

https://www.airpurifiersandcleaners.com/kes-acs-50-xl-commercial-air-sanitizer

Downside is it needs to be cleaned often, and thoroughly...

Actually the use of electrostatic precipitation only works with particles having a low enough resistance to have a charge induced in them. I worked for 5 years on electrostatic precipitators in the flu gasses of a power station and the particles had such a high resistance as to be difficult to ionise. We were dealing with particles with gigohms of resistance mainly of SiO2 so any design needs to be cognisant of the particle paramaters.

<...smoke...visualize the spread of the C19...>

So what?

Any <...smoke...> is influenced by thermal air currents relating to the associated (pre-)combustion conditions and heat dissipation at its point of origin.

The heat associated with exhaling air is of a lower order of magnitude.

Go into a room where someone is smoking, and you can visualize the spread of the C19

Except a sick person might be sneezing and coughing, which would spread the disease over a greater distance.

"A cough can travel as fast as 50 mph and expel almost 3,000 droplets in just one go. Sneezes win though—they can travel up to 100 mph and create upwards of 100,000 droplets."

What we're missing here is quantity per sq cm of viruses, the density between the two is an issue...The virus particles are contained in droplets which range in size from 1 μm to 500 μm, that rapidly evaporates and the quantity of viruses in each droplet varies....

...."Highly sensitive laser light scattering observations have revealed that loud speech can emit thousands of oral fluid droplets per second. In a closed, stagnant air environment, they disappear from the window of view with time constants in the range of 8 to 14 min, which corresponds to droplet nuclei of ca. 4 μm diameter, or 12- to 21-μm droplets prior to dehydration. "...

...."According to Stokes’ law, the terminal velocity of a falling droplet scales as the square of its diameter. Once airborne, speech-generated droplets rapidly dehydrate due to evaporation, thereby decreasing in size (13) and slowing their fall. The probability that a droplet contains one or more virions scales with its initial hydrated volume, that is, as the cube of its diameter, d. Therefore, the probability that speech droplets pass on an infection when emitted by a virus carrier must take into account how long droplet nuclei remain airborne (proportional to d−2) and the probability that droplets encapsulate at least one virion (proportional to d3), the product of which is proportional to d.

The amount by which a droplet shrinks upon dehydration depends on the fraction of nonvolatile matter in the oral fluid, which includes electrolytes, sugars, enzymes, DNA, and remnants of dehydrated epithelial and white blood cells. Whereas pure saliva contains 99.5% water when exiting the salivary glands, the weight fraction of nonvolatile matter in oral fluid falls in the 1 to 5% range. Presumably, this wide range results from differential degrees of dehydration of the oral cavity during normal breathing and speaking and from decreased salivary gland activity with age. Given a nonvolatile weight fraction in the 1 to 5% range and an assumed density of 1.3 g⋅mL−1 for that fraction, dehydration causes the diameter of an emitted droplet to shrink to about 20 to 34% of its original size, thereby slowing down the speed at which it falls (1, 13). For example, if a droplet with an initial diameter of 50 μm shrinks to 10 μm, the speed at which it falls decreases from 6.8 cm⋅s−1 to about 0.35 cm⋅s−1. The distance over which droplets travel laterally from the speaker’s mouth during their downward trajectory is dominated by the total volume and flow velocity of exhaled air (8). The flow velocity varies with phonation (14), while the total volume and droplet count increase with loudness (9). Therefore, in an environment of stagnant air, droplet nuclei generated by speaking will persist as a slowly descending cloud emanating from the speaker’s mouth, with the rate of descent determined by the diameter of the dehydrated speech droplet nuclei."...

..." For COVID-19, with an oral fluid average virus RNA load of 7 × 106 copies per milliliter (maximum of 2.35 × 109 copies per milliliter) (7), the probability that a 50-μm-diameter droplet, prior to dehydration, contains at least one virion is ∼37%. For a 10-μm droplet, this probability drops to 0.37%, and the probability that it contains more than one virion, if generated from a homogeneous distribution of oral fluid, is negligible."...

https://www.pnas.org/content/117/22/11875

<...droplets rapidly dehydrate due to evaporation...amount by which a droplet shrinks upon dehydration depends on the fraction of nonvolatile matter in the oral fluid...>

Particles of <...smoke...> don't do that.

CFD actually does a better job of simulation models. Where smoke maybe a visual, but amounts to nothing more than some wind tunnel test the shows the path and characteristics of an airflow over an object.

Great test...

MISINFORMATION !!!!!

You are going to be shut down for exhibiting or even suggesting or implying a modest shred of common sense. You shall not disparage the myth of mask effectiveness for it has been decreed from those who know better than anyone else because they said so!!! Follow the science you denier you !!

For sure, no doubt. Even now, Cuomo's on giving the Daily Bloviation. Here's his self-esteem gauge from his limo and mansion. I think I know where the sensor is.

Hey HTR,

As we are now a year into this and America is just waking up and getting moving on it we should see some much better science over the next few months.

There have been umpteen air movement studies. Most intentionally skewed to prove a point not validate or invalidate a scientific theory. This creates a lot of confusion and misinformation which has then been intentionally used to hamper our response.

An axe is vital to keeping you warm. it is an invaluable tool for survival. it can also be perverted into something far more sinister depending on the INTENT of the user.

I disagree,

Who said America is just waking up and getting moving on it?

Things don’t happen over night... especially starting with nothing, no data, no history (with the exception of other COVID virus’s), no long term studies,.., zero.

America has been moving on this quite early, but America had to start at Zero. With very little help from WHO, who appears to even withhold information.

I am afraid as the history of this is written you will see how misled we all were by people who tried to profit off of this disaster. Time will tell.

I agree, You’re probably right on this,...

I totally agree on this point.

Damn. That was fast. LoL

Missouri lawmaker indicted for allegedly selling fake stem cell treatments for Covid-19 (msn.com)

That is horrible. An elected official deceiving the public. There's not enough prison beds for all of them. What do we do?

We could release all those jailed for victimless crimes, and incarcerate the real criminals...

The parallel I was trying to illustrate here is if you can smell smoke with the mask on,it will not block Covid.

I think that is an inaccurate and possibly dangerous guide for many reasons. First, people's sense of smell varies wildly. Second, I believe the particulate size in smoke you reference is predominantly the carbon soot particles. Carbon not only has no smell but carbon is used to absorb aromas. The smell in smoke are aromatic hydrocarbons that are much smaller than COVID-19 spores.

Seeing smoke able to stream through a mask is clearly a frugal test on the efficacy of that mask. This maybe the only good thing that tobacco smoke is good for.

Are you sure you are an engineer?

Seriously?

That rates right up there with bringing a snowball to congress as proof that climate change isnt happening.

A snow ball is useless, if not used properly...

How would this work in relation to farts ?

Quite.

"Go into a room where someone is smoking, and you can visualize the spread of the C19."

Good grief - this nonsence is still here ?