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[2] UV inactivation kinetics:
282nm & 270nm LED, 254nm Hg lamp and 222 nm KrCl excimer tested in liquid solution in petri dish. Most effective was unfiltered KrCl with k=1.52 cm^2/mJ. LED's at 0.93 and 0.73 respectively
Note correction used for absorption of UV due to apparatus
282nm & 270nm LED, 254nm Hg lamp and 222 nm KrCl excimer tested in liquid solution in petri dish. Most effective was unfiltered KrCl with k=1.52 cm^2/mJ. LED's at 0.93 and 0.73 respectively
Note correction used for absorption of UV due to apparatus
[3] Filtered got 1.42 cm^2/mJ, and likely would be needed for occupied space use. Tested Phi6, HCOV229E, MHV and SARS-COV-2. Good news is COV-2 was easiest to kill and similar to HCOV 229E, meaning can use a surrogate and easier to deal with.
[4] With just 222nm, T1 UV showed very similar inactivation kinetic to SARS-COV-2 so likely a very good surrogate to use for testing at that wavelength.
[5] 222nm vs 254nm ?
For bacteria 254nm is better, but for virus 222nm is better by almost 2x. But why? Perhaps the higher absorption by proteins for 222nm may be root cause.
I think in terms of future pandemics being likely virus based, this is good news.
For bacteria 254nm is better, but for virus 222nm is better by almost 2x. But why? Perhaps the higher absorption by proteins for 222nm may be root cause.
I think in terms of future pandemics being likely virus based, this is good news.
[6] Surfaces
UV light can be absorbed by dried deposits, and backside reflection from surface. Tested with different absorbents in solution, more absorbent dried solution, less inactivation. Makes sense
To me this means for surfaces, may be sensitive to what pathogen is in.
UV light can be absorbed by dried deposits, and backside reflection from surface. Tested with different absorbents in solution, more absorbent dried solution, less inactivation. Makes sense
To me this means for surfaces, may be sensitive to what pathogen is in.
[7] Virus inactivation surfaces also shows higher rates than for bacteria. Metal surface have higher reflection(40-60%) vs plastics in the <10%. Meaning reflection gives a second pass through the virus on the surface.
[8] Lot of data shown comes from this paper
onlinelibrary.wiley.com/doi/10.1111/ph…
onlinelibrary.wiley.com/doi/10.1111/ph…
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https://twitter.com/masknerd/status/1669009147713703936?s=20
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