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I've worked for a company that measures PM2.5 in the past. Using a HEPA filter to remove PM2.5 seems unlikely to me. Perhaps there's something more going on here than I've picked up from a quick skim of the site (perhaps there's some sort of cyclonic separation happening) but I'm skeptical this is actually removing particulate at that scale.


I'm not sure I get what you're saying here, HEPA is a standard that was developed for medical environments & clean rooms [1]. To qualify as HEPA, a filter should be able to remove 99.97% of particles 0.3µm and above so it is definitely impacting PM2.5 (particles 2.5µm and below).

See my other comment [2] for my opinion on smartair solutions.

[1] https://en.wikipedia.org/wiki/HEPA [2] https://news.ycombinator.com/item?id=17720802


I was under the impression that the filtration efficiency by particle size for such a filter was not a linear relationship.[0] So manufacturing to a lower bound of 3 may not say much for particles even slightly smaller. My estimation of the magnitude of this effect may be off however as this company seems to suggest.

[0]https://www.globalspec.com/learnmore/manufacturing_process_e...


Yes, self selection as a response to perceived discrimination, or "lack of fit", is different from outright discrimination. But no less a problem, and certainly not unchangeable!


perceived discrimination can be anything.

Personal choice in a clearly gender egalitarian society is still personal choice.


Which society is as “clearly gender egalitarian society”?


Would you settle for "close enough"? I would guess that Sweden is probably close enough. So, what's the fraction of CS students in Sweden who are female? If it's close to the fraction in the US, then the US is also probably "close enough" (in that specific way, by that measure).


I absolutely have seen a decrease in quality. I used to be able to use keywords to divide the search space very effectively (ie "programming language" "concept" "version"). Now it seems that Google is concerned with over fitting and they've relaxed the power of each keyword to filter results (sometimes ignoring them altogether). The end result is I tend to get articles that are more general and it's difficult to get a highly detailed forum post or blog anymore.


Not if you include those that did not survive in your sample / analysis. From the link "concentrating on the people or things that made it past some selection process and overlooking those that did not".


Note also if for some reason the payment fails (for example an error with the captcha) the payment resets to $25. Didn't catch it the second time through the payment process.


Isn't the $100,00K in this case the premium on the option? Taking the price SoftBank is offering, $33, those 20,000 shares are worth 660,000 so a net profit of 560,000 and a tax of about 35%. This seems a little high still so there might be something I'm missing.


Ishitani Furniture. Amazing woodworking craftsmanship. There's no voice over (and also little music) so it's not strictly informational but it's so peaceful and beautiful to see everything come together.


Heard a similar story about a laboratory system with tight environmental controls. Every so often the humidity would spike and the room would go out of tolerance after typical work hours. The designers of the system were under quite a bit of pressure until someone finally stuck around long enough to catch the janitor mopping the floors.


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