4 ms·

Note that hydrogen sulfide is in the realm of hydrogen cyanide in terms of toxicity. (Unfortunately, Wikipedia doesn't have comparable LC50 times for humans, b

by KMag 11y ago

Note that hydrogen sulfide is in the realm of hydrogen cyanide in terms of toxicity. (Unfortunately, Wikipedia doesn't have comparable LC50 times for humans, but for H2S we're talking 600 ppm for 30 min and HCN is 357 ppm for 60 min.) We're unlikely to see high-pressure H2S lines running through residential neighborhoods any time soon.

niels_olson 11y ago
Funny, H2S is a natural product of sewage. And on vessels sewage lines are frequently pressurized. Maybe not to your house, but maybe there are some limited uses.
- KMag 11y ago
  Being natural doesn't make H2S safe, especially at 1,000,000 ppm under high pressure. There's nothing funny about it. In many areas sewer workers are required to check H2S levels above manhole covers before opening, because it sometimes kills sewage workers. If the sewer smells, the H2S level is probably below 150 ppm. Starting at 100 ppm, H2S begins to paralyze the olfactory nerve and the sewer stops stinking.
  - niels_olson 11y ago
    Maybe I should have said "interesting" instead of "funny". Of course, the reason I know about H2S in sewage is that I was in charge of all the water and sewage piping systems on my first ship. Including safe re-entry and emergency response to leaks. So, yes, I'm quite aware of the hazard presented by H2S. I wouldn't advocate running it residentially, but perhaps in high power low voltage situations like inside a power plant, or major substations, it might make sense.
knodi123 11y ago
Hydrogen sulfide is in farts. About one percent, if I recall correctly? "Silent but deadly" indeed.
- dexwiz 11y ago
  If you were sitting in a room of 100% pure fart, pretty sure you would die.
  - leoc 11y ago
    Signs are on it: http://www.bbc.com/news/uk-northern-ireland-27754408 http://www.bbc.com/news/uk-northern-ireland-27754408 .
- zamalek 11y ago
  Probably much less than 1% - you can smell H2S at incredibly low concentrations. Single digits parts per million AFAIR. Edit: at 0.00047 ppm you know something is there. 2 ppm is dangerous. At 10–20 ppm you would experience eye irritation. At 100–150 ppm your nose goes numb. All far below 1%. Edit 2: the concentration of farts would obviously be higher than, uh, "outside," but as much as 1% would probably cause harm to yourself and anyone around you.
leoc 11y ago
> We're unlikely to see high-pressure H2S lines running through residential neighborhoods any time soon. That wouldn't be necessary to make the technology commercially viable, though. Forty years ago Cray sold over eighty Cray-1s, initially priced at the equivalent of about USD 35 million today, and there were probably much larger numbers of mainframes, scientific computers like the PDP-10 and so on that could go for about $1m in today's money. If anyone today could offer much faster single-core execution speed at comparable costs I'm sure they could sell similar numbers of systems, especially since the infrastructure for remote timesharing and job execution is much better and more widespread nowadays. It's the titanic pressures needed to keep the material solid at all that make the idea infeasible at present I assume (how would you even whittle a circuit out of it?)

by KMag 11y ago

niels_olson 11y ago

Funny, H2S is a natural product of sewage. And on vessels sewage lines are frequently pressurized. Maybe not to your house, but maybe there are some limited uses.

KMag 11y ago
Being natural doesn't make H2S safe, especially at 1,000,000 ppm under high pressure. There's nothing funny about it. In many areas sewer workers are required to check H2S levels above manhole covers before opening, because it sometimes kills sewage workers. If the sewer smells, the H2S level is probably below 150 ppm. Starting at 100 ppm, H2S begins to paralyze the olfactory nerve and the sewer stops stinking.
- niels_olson 11y ago
  Maybe I should have said "interesting" instead of "funny". Of course, the reason I know about H2S in sewage is that I was in charge of all the water and sewage piping systems on my first ship. Including safe re-entry and emergency response to leaks. So, yes, I'm quite aware of the hazard presented by H2S. I wouldn't advocate running it residentially, but perhaps in high power low voltage situations like inside a power plant, or major substations, it might make sense.

knodi123 11y ago

Hydrogen sulfide is in farts. About one percent, if I recall correctly? "Silent but deadly" indeed.

dexwiz 11y ago
If you were sitting in a room of 100% pure fart, pretty sure you would die.
- leoc 11y ago
  Signs are on it: http://www.bbc.com/news/uk-northern-ireland-27754408 http://www.bbc.com/news/uk-northern-ireland-27754408 .
zamalek 11y ago
Probably much less than 1% - you can smell H2S at incredibly low concentrations. Single digits parts per million AFAIR. Edit: at 0.00047 ppm you know something is there. 2 ppm is dangerous. At 10–20 ppm you would experience eye irritation. At 100–150 ppm your nose goes numb. All far below 1%. Edit 2: the concentration of farts would obviously be higher than, uh, "outside," but as much as 1% would probably cause harm to yourself and anyone around you.

leoc 11y ago

> We're unlikely to see high-pressure H2S lines running through residential neighborhoods any time soon. That wouldn't be necessary to make the technology commercially viable, though. Forty years ago Cray sold over eighty Cray-1s, initially priced at the equivalent of about USD 35 million today, and there were probably much larger numbers of mainframes, scientific computers like the PDP-10 and so on that could go for about $1m in today's money. If anyone today could offer much faster single-core execution speed at comparable costs I'm sure they could sell similar numbers of systems, especially since the infrastructure for remote timesharing and job execution is much better and more widespread nowadays. It's the titanic pressures needed to keep the material solid at all that make the idea infeasible at present I assume (how would you even whittle a circuit out of it?)