Tuesday, August 31, 2021

Thoughts on Improving Air Cleaners for Covid

 With the return of school and offices moms and dads especially are paying increased attention to air cleaners. You can buy small units for not so much money, but they are a couple of hundred dollars, and putting something together out of a fan, some A/C filters and duct tape is easy and a lot less expensive. 

One simple design is called a Corsi-Rosenthal Cube. Eli has been thinking for a while about air filters. The bunny changed out the A/C filters in his house last year and recommended the same to his sadly low number of Twitter followers

September 23, 2020

So where is this going, well Eli would like to suggest three improvements. The first builds off an early 2020 observation that copper, or at least some copper alloys, effectively kills Covid virus. It has been known for some time that viruses are inactivated by copper surfaces. Govind, V., Bharadwaj, S.,  et al. summarize this in their review article Antiviral properties of copper and its alloys to inactivate covid-19 virus. Biometals (2021). https://doi.org/10.1007/s10534-021-00339-4, so, of course it was a natural thing to look at when Covid-19 raised it's ugly heat. N Van Doremalen, T Bushmaker, DH Morris, et al, were the first to publish in March 2020 in the New England Journal of Medicine Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1. Eli remembers looking at that then, and since so have about five million others, with 7500 citations.

The EPA has authorized the use of copper for this purpose and already things like copper handrails and doorknobs are on sale as anti-covid devices
Today, the U.S. Environmental Protection Agency (EPA) is announcing that certain copper alloys provide long-term effectiveness against viruses, including SARS-CoV-2, the virus that causes COVID-19. As a result of EPA’s approval, products containing these copper alloys can now be sold and distributed with claims that they kill certain viruses that come into contact with them. This is the first product with residual claims against viruses to be registered for use nationwide. Testing to demonstrate this effectiveness was conducted on harder-to-kill viruses.
Copper, of course comes in all sorts of shapes and sizes. For Eli's application extra fine copper wool appears to be the ticket. You can even get copper wool for cleaning your pots. A layer or two of this stuff on the inside of the Corsi-Rosenthal Cube, or on the inside of your A/C filter would inactivate a lot of Covid-19. Any mechanical engineer could optimize the flows for maximum efficiency. If the size of the copper wire bothers you, it could always be drawn finer but that would really not be necessary. 

Although the wire is much larger than the virus or the aerosols carrying it, because the path through the many layers of the wool would be kinky the odds on an aerosol particle hitting a wire are excellent. It would work the same way as, well N95 masks work, where multiple layers ensure that the aerosols are captured as shown in this video

But because copper is a conductor, there is another, and perhaps more important trick we can use. The N95 mask has a layer which is composed of electrets which attract and capture virus aerosols! But what if there are two layers of copper wool separated by an insulator! They can be charged up with a small battery or some sort of simple power supply. 

So by combining three things
1. Copper inactivation of Covid 19 virus
2. A tortuous path through fine copper wool
3. Static electrical attraction of the virus to the copper wire,
Perhaps a better Covid air filter at low cost and high efficiency. TM-ER

Sunday, August 08, 2021

Hard problems, fear and solutions: Pick two

 Just the other day Eli was innocently pushing the search engine, coming across this article in the Washington Post from 2017. BTW, there are two published papers on the subjects that the diligent might care to read, "Immunizing against prejudice: Effects of disease protection on outgroup attitudes" Julie Y. Huang  Alexandra Sedlovskaya, Joshua M. Ackerman and John Bargh and  "Superheroes for change: Physical safety promotes socially (but not economically) progressive attitudes among conservatives", Jaime L. Napier , Julie Huang, Andrew J. Vonasch and John A. Bargh again.  Both are open, so never fear.

Now the Bunny is not so innocent in the wiles of psych papers that every word is to be believed, but the direction the article and the papers take is a useful one to ponder. Bargh writes about the roots of political orientation.

For example, over a decade now of research in political psychology consistently shows that how physically threatened or fearful a person feels is a key factor — although clearly not the only one — in whether he or she holds conservative or liberal attitudes.

 At this point a bit more reading and Eli became cautious about assigning political parties to conservative and liberal, but rather thinking of these as states of mind which are loosely correlated (a lesson taught by observing relatives). Bargh goes on 

Conservatives, it turns out, react more strongly to physical threat than liberals do. In fact, their greater concern with physical safety seems to be determined early in life: In one University of California study, the more fear a 4-year-old showed in a laboratory situation, the more conservative his or her political attitudes were found to be 20 years later. Brain imaging studies have even shown that the fear center of the brain, the amygdala, is actually larger in conservatives than in liberals. And many other laboratory studies have found that when adult liberals experienced physical threat, their political and social attitudes became more conservative (temporarily, of course). 
But, of course, politicians, at least the ones who succeed, are at a deep level aware of this, may have even read these papers, and certainly find it in life's lessons
This is why it makes sense that liberal politicians intuitively portray danger as manageable
and why  the other side is
instead likely to emphasize the dangers of terrorism and immigration, relying on fear as a motivator to gain votes.
There is something missing here, perhaps the description of one of the experiments will help
In fact, anti-immigration attitudes are also linked directly to the underlying basic drive for physical safety. For centuries, arch-conservative leaders have often referred to scapegoated minority groups as “germs” or “bacteria” that seek to invade and destroy their country from within. . . .

“Immigrants are like viruses” is a powerful metaphor, because in comparing immigrants entering a country to germs entering a human body, it speaks directly to our powerful innate motivation to avoid contamination and disease. Until very recently in human history, not only did we not have antibiotics, we did not even know how infections occurred or diseases transmitted, and cuts and open wounds were quite dangerous. . .

Therefore, we reasoned, making people feel safer about a dangerous flu virus should serve to calm their fears about immigrants — and making them feel more threatened by the flu virus should cause them to be more against immigration than they were before. In a 2011 study, my colleagues and I showed just that. First, we reminded our nationwide sample of liberals and conservatives about the threat of the flu virus (during the H1N1 epidemic), and then measured their attitudes toward immigration. Afterward we simply asked them if they’d already gotten their flu shot or not. It turned out that those who had not gotten a flu shot (feeling threatened) expressed more negative attitudes toward immigration, while those who had received the vaccination (feeling safe) had more positive attitudes about immigration.

In the context of today's mess, about COVID, climate change and more, this says that the way to conservatives' agreement is to emphasize solutions. The opposition will take the other track and seek to vilify outgoups. Denial of solutions is a tactic to increase fear, if there are no solutions, then fear is unavoidable.

Sound familiar?

So with the anti-vaxxers, the climate change deniers and yes the no-hopers, emphasize progress and solutions.