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Working From Home - Impacts of Coronavirus

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rdl:
Seems to me the fall off of UV light intensity from any kind of bulb or tube makes them impractical for disinfecting most things. You'd probably need someone manually moving the light over every surface at a distance of just a few inches to do any good at all. Commercial water sterilizers use jacketed tubes where the water flows past relatively close to the UV emitter.

cdev:
If they say it hasnt been proven that really is almost a confession that they know it won't work.

I recently saw a patent for a robotic disenfector, presumably thats what it does it automates the process.. But, Id still expect it to take a long time to do a big subway car.

Arrgh... what  a mess..

I have a huge double bulb UV lamp that I have had for decades its very bright. But it is a black light, UVB which is not very good for disinfection, I am pretty sure. It may not even work at all. Nor is it good for tanning.

OTOH, UVA is good for tanning and okay for disinfection, although not as good as UVC.
I have a small handheld UVA lamp that I have used for a number of different things, microscopy, minerals, photography. Its a short wavelength lamp so you need to protect your eyes from it if you are using it for a long time.

I totally agree with you, when a disinfecting light is claimed to kill germs, IMHO they likely have to demonstrate effectiveness. And yes, water is disinfected by passing it through plates of glass where the light intensity is very high..


--- Quote from: nctnico on May 21, 2020, 09:55:54 pm ---
--- Quote from: cdev on May 21, 2020, 09:17:33 pm ---UV light does kill pathogens. Its one of the ways that municipalities disinfect water. So if it didnt work many of us would probably have cholera or something like that. We use it every day. Also, the Sun is why we aren't buried in germs. Exposure to sunlight kills a lot of germs.

--- End quote ---
I guess you didn't read the article. It clearly says the method of using UV to clean subway cars has not been scientifically proven. What else is there to say? You also have to realise that they intend to use the UV light during cleaning. Not during driving around so while the car is in service it will get dirty and people will transfer virusses. So in the end it is just a different way of disinfecting a subway car.

--- End quote ---

Nusa:

--- Quote from: nctnico on May 21, 2020, 09:55:54 pm ---
--- Quote from: cdev on May 21, 2020, 09:17:33 pm ---UV light does kill pathogens. Its one of the ways that municipalities disinfect water. So if it didnt work many of us would probably have cholera or something like that. We use it every day. Also, the Sun is why we aren't buried in germs. Exposure to sunlight kills a lot of germs.

--- End quote ---
I guess you didn't read the article. It clearly says the method of using UV to clean subway cars has not been scientifically proven. What else is there to say? You also have to realise that they intend to use the UV light during cleaning. Not during driving around so while the car is in service it will get dirty and people will transfer virusses. So in the end it is just a different way of disinfecting a subway car.

--- End quote ---

You're overstating it as a total negative rather than a process with strong potential. UV-C is a proven disinfectant method that's been shown to be very effective against all sorts of things, including other coronaviruses. The only thing that's not proven is how effective it is on CV-19. And, of course, whether it's being applied correctly in this case. Note that it's very unhealthy to be in the same area as an operating UV-C lamp, so the method is not practical to use while the car is occupied.

Sunlight is also useful, but it takes a LOT longer than a germicidal lamp. Very little UV-C reaches the surface of the earth...most is blocked by the atmosphere. If it did, you'd have a lot more people with serious skin and eye conditions.

https://sites.nationalacademies.org/BasedOnScience/covid-19-does-ultraviolet-light-kill-the-coronavirus/index.htm

Electro Detective:

UV light, besides giving plaque covered teeth a white and shiny appearance at nightclubs and retro disco parties  8)
keeps already sterilized surgery gear that way for long periods.

UV can only _suppress_ at best, any active pathogens lurking in filth, good luck killing anything long term
 
What's needed for serious train cleansing
(and bus, car, truck, tram, ferry, plane, jet, helicopter, horse buggy, canoe, dog sled, space shuttle, and rickshaw modes of travel)
is pressure hose down the trains inside and out with IPA
and Glen20, Windex, Mortein and elbow grease, to wipe out any stray mutations or blobs attempting escape spotted by UV.   

Once dry and totally sterile, all commuters are only permitted to travel in full sized vacuum sealed prophylactic suits 
with Scuba or Nasa Approved breathing gear, all tested and tagged at authorized outlets and kiosks before each trip. 

= farewell corona local and internationally in 6 years or less > 'don't call us, we'll call you..'    :D


The good news for lucky 'Working From Home' people is, you won't won't have to do any of that 'Stay Sealed, Save Lives' thing just yet.
But better prep up mentally and shop around for a good deal on all that gear on Ebay and Ali,
for when that cushy 'it can't/won't affect me..'  ???   Working From Home gig dries up and blows away.
Come on guys, nothing lasts forever, including cushy job flexibility when the boss has to begin pruning wages and salaries,
and or consider a shut down till further notice,
or close down and get out while the getting's good  :phew:

i.e. flog the boutique bike/s, hoarded test gear and previous job 'goodbye' gold (?!) watch now,
before they are worth less than a slab of 3 ply toilet paper    :palm:


Disclaimer: if some unemployed bankrupt homeless  'down with big brudder and their corona b!tch'  T-Shirted unshaved *err0rist group jacks a train
and threatens to rip open a commuters prophylactic suit, whilst streaming the proceedings to Youtube and Facebook,
things might get messy,
and other more secure sterilization options may have to be considered,
after they pay off the *err0rist group with back pay, forward pay, stfu pay

and new   'Have A Nice Day Sukkas'   :)   T-Shirts 


james_s:

--- Quote from: rdl on May 21, 2020, 11:33:43 pm ---Seems to me the fall off of UV light intensity from any kind of bulb or tube makes them impractical for disinfecting most things. You'd probably need someone manually moving the light over every surface at a distance of just a few inches to do any good at all. Commercial water sterilizers use jacketed tubes where the water flows past relatively close to the UV emitter.

--- End quote ---

I read a study a while back where they tested with a 4' 32W UVC germicidal tube and found that it was effective at a distance of 8 feet with an exposure time of 30 minutes. This was not for Covid-19 as it was not around yet but for some other pathogens, a bacteria I think. These lamps have been used for many years to disinfect hospital facilities, I remember back when I was in school the shop and science classrooms had cabinets for the safety glasses that had a germicidal tube in it to sterilize the glasses between classes.

They're practical for disinfecting things but it takes time, it's not like you can just pass the light over the surface and have everything die. Also they produce quite large amounts of ozone and the UV rapidly degrades many polymers, fades dye, etc.

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