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MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Farside posted:

Now it might be because I work around these drat things day in and day out but a dewar with a properly working safety venting off isn't going to fill an elevator car with enough gas to make an elevator car oxygen deficient. 5psi (max) vent at 1-2 seconds (max) from a 1/2" safety isn't going to kill you. Especially since most elevator cars aren't exactly air tight or with out their own ventilation systems.
To answer your questions almost every single Liquid Nitrogen tank I've seen has a 22psi and a 230 psi safety with the 230 psi safety displacing enough air to kill you in an elevator. The 230 psi safety is if you are running the tank as an air source will the 22 psi safety is only for liquid nitrogen.

MadScientistWorking fucked around with this message at 20:05 on Jul 21, 2011

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MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Fucknag posted:

Your average household extinguisher can't do poo poo for a magnesium fire, and a hose will make things worse, since magnesium decomposes water into oxygen and hydrogen gas. He did the right thing calling the fire department and staying away from it.
Except for the fact that he was staring at the fire like a moron which in this case means you are going to blind yourself.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


grover posted:

Technically, it still happens with sealed batteries, but it isn't released during normal operation. If overcharged, they can still outgas significant amounts of hydrogen. Another big risk is thermal runaway.
Sealed Lead Acid batteries have vents in them which are designed to prevent that sort of failure. You can theoretically make a bomb by potting the battery and inducing a failure that requires venting.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


The Scientist posted:



Among the latter, Dichloromethane is curious because not only is it a super volatile solvent, but (perhaps directly linked to this characteristic) its boiling point is so low it works awesome in heat engines (e.g. sterling engines). You know that weird little bird that rocks back and forth and "drinks" water from a cup with a bulb full of colored liquid? Its full of Dichloromethane. You know those bubble lights that you put on your christmas tree and one spontaneously exploded and stained the couch while everyone was outside on christmas day and no-one believed that you weren't even anywhere near it when it happened and blamed you? Dichloromethane.


Dichloromethane is fun to work with. It quite literally will dissolve certain plastic materials and is a common way to weld certain plastics together.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Geoj posted:

More of "Horrible structural/engineering failures" but I couldn't find anywhere else on the forum for stuff like this: Why its a good idea to not build a shopping plaza on top of a capped landfill.
I'm always surprised that Boston didn't turn out like that shopping center. The city primarily consists of landfill.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


the poi posted:

b) Nitrogen-filling tires isn't to get the oxygen out, it's just to keep it free of water. Pumping in atmospheric air puts a good deal of water in the tire, which will change the tire pressure greatly as it vaporizes and condense.
Its pretty much a scam. A good air compressor is going to pumping in dry air regardless of whether or not you're atmospheric air.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Bang Me Please posted:

Only if you've got a drier in the line after the compressor. Water will still collect on hot & humid or rainy days even in new compressors.
Yeah but any person who doesn't want their equipment utterly destroyed should have one.
Anyway, I wish I had my camera today. I saw my first horrible mechanical failure that probably pissed off everyone on Massachusetts avenue in Boston. There was a bus spurting off so much smoke in its exhaust that it literally through the entire street into a fog. Anyone care to guess what it was? I'm guessing oil but holy crap.

MadScientistWorking fucked around with this message at 05:34 on Dec 10, 2011

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


quote:

I wish I could find it, but I believe in this very thread (IIRC) is a long conversation detailing how a surprising percentage of the people who deliver/store liquid nitrogen are oftentimes extreme yobbos who seem to have no problem replacing removing pressure relief valves, or transporting dewars inside elevators or other dangerous closed spaces.
I missed this but transporting dewars in elevators isn't all that dangerous. A liquid nitrogen dewar that I typically use is triple redundant. You have the 30 PSI safety valve, a 120 PSI safety valve, and a burst cap somewhere.

quote:

Probably a boost leak or turbo failure (one that didn't cause a ton of oil to go down the intake). Usually when diesels start drinking their own oil they go into a runaway state.
Thanks. It sure was spectacular though. Like one of those old fashion villain fog weapons.

MadScientistWorking fucked around with this message at 05:41 on Dec 10, 2011

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Geirskogul posted:

Found it, starting post

http://forums.somethingawful.com/sh...0#post392091874
Oooo yeah. The most disturbing thing as I pointed out is that those dewars typically have three safety features. Someone idiotically circumvented three safety valves on the device.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."



Actually, I should ask this. By dewar what do you mean? That can refer to five differently shaped pieces of equipment I have sitting in my lab.

MadScientistWorking fucked around with this message at 14:09 on Dec 10, 2011

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Splizwarf posted:

It's going to die the same way. Rivets through woven material never ends well, what a loving stupid design.
Is that an operator or design gently caress up?

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Ferremit posted:



Well that explains the chunky bits I found- they were the brushes!

Ive never seen this before- theres nothing else in the motor assembly thats loose- so its not like a wayward chunk of metal bent the armature up like that- its the brushes that have done that!

Looks like we're up for a new motor


In theory you can fix that because it wasn't as horrible as you think it was. Those pieces generally are replaceable.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Sponge! posted:

The sad part? The jerrycan on the passenger seat is probably SAFER than the factory tank was, when new. At least in terms of rear-end collisions...
Ironically, at one point the Pinto theoretically could have had one of the safest gas tanks even to this day.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Didn't Mythbusters show that if a tire was to catastrophically fail in the right way it could basically rip someone's head off?

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Nathan Explosion posted:

That Mythbusters ended up being one of those that they had to really reach to make happen. They basically made a big pitching machine out of that truck and fired a chunk of retread out of it.

No. They didn't really reach at all for that one because all they did was measure how fast the tread was speeding out when it did actually fail. The problem being that it was being flung out in every which direction except the location of where the dummy was. At that point you know you can get a tire to fail and shoot off at 40 MPH now how deadly is it.

MadScientistWorking fucked around with this message at 21:20 on Aug 20, 2012

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Beach Bum posted:

They're "Single Use" because LocTite is apparently inferior to the "Superior Bavarian Threadlocking Compound (Special Part #34111163421 DEALER ONLY)

Use LocTite/torqewrench for reassembly, give no fucks.

I have a feeling that they sell it themselves for one of two reasons. Either you are completely wrong and its not actually loctite or to prevent idiots from super gluing their parts together.

MadScientistWorking fucked around with this message at 21:13 on Dec 7, 2012

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Motronic posted:

The terrifying thing would be if it's NOT doing that. Same thing for bridges.

I remember way back when I was first taking high angle rescue courses and we were out on a bridge that was swaying all over the place. I joked to the bridge engineer "this is what it's supposed to be doing, right?" and he got all serious and said "if you are EVER on something this size in the wind or with traffic on it and it's not moving at least this much you need to run as fast as you loving can off of it."
And buildings. In fact one of the things on my to do list is to Taipei 101. A building known for containing the world's largest tuned mass damper meant to reduce stress from the movements in the building. What is it? Its a 660 ton pendulum ball that at its worst conditions actually moves 1.5 meters. Also, I guess the wobbly Millennium Bridge does count as a mechanical failure.
http://en.wikipedia.org/wiki/London...ridge#Resonance

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


thelightguy posted:

Battery offgassing hydrogen + spark. Believe it or not, it's not really common knowledge that you should clip the negative clamp to something metal that isn't the battery.
I don't own a car haven't driven one in about eight years and yet even I know that.

thelightguy posted:

I have faith that even the most idiotic of idiots could manage to match color to color. Sparking off a battery that's offgassing because they didn't read the loving instructions on the jumper cable package? That's much more plausible.
Ehhhh... People aparently have turned batteries into bombs due to the offgassing phenomeon so nothing surprises me.

MadScientistWorking fucked around with this message at 16:26 on Feb 1, 2013

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


kastein posted:



Asbestos fibers, long? They'll cause damage but not that much. Short/crushed asbestos? You're probably hosed. Incredibly finely crushed asbestos, like the dust that came from the 9/11 attacks and resulted in accelerated (normal cases of asbestosis and mesothelioma take 10-50 years to occur, these cases were starting to show up in the first year or two) cases of asbestosis/similar diseases? Yeah, you're really hosed.


Was it the asbestos to blame because lord knows finely crushed dust composed of multiple toxic chemicals can't possibly be healthy under any conditions?

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Preoptopus posted:

Hey Londers, dont park next to this building.


Or this might happen.


Wow. I can't believe that someone was moronic enough to turn a building into a reflective lens a second time. The first time being was Disney Opera House in California. What is it with architects and curved surfaces that they don't realize that they might just end up turning it into a giant lens? At least with the opera house they were able to sandblast the curved surfaces as it was just a metal lining.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


tater_salad posted:

Ratchet straps would be an accepted redneck fix duct tape is pure lazy
Ehhhh.... I think some of the more redneck fixes of redneck fixes involved fixing a fender with duct tape, a map, and a couple of clamps.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


rscott posted:

Isn't there a bit of magnesium in the engine bay as well? That likes to burn.
If you actually create a fire hot enough to ignite magnesium the magnesium is the least of your worries.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Motronic posted:

Oh, but they fixed that! It's no longer a problem!

(so the component manufacturers keep saying, and so we all keep finding out is a load of crap - guess it's time to blame it on counterfeits again)
No they fixed the problem where an inordinate amount of them failed early. Capacitor rot as a failure mode is incredibly common especially in older devices because of the inherent problems of having a device that relies on water to operate correctly. I just dealt with a 200V power supply that I assumed was going to catch on fire because my initial assumption was that the electrolytic capacitors were completely devoid of any water.

MadScientistWorking fucked around with this message at 17:12 on Apr 18, 2014

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


kastein posted:

You can be fatally electrocuted by a 9 volt battery if you are dumb enough. http://www.darwinawards.com/darwin/darwin1999-50.html

Nope. Its not possible in the way the story describes it.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Amykinz posted:

I thought that a great deal of the Darwin Awards stories were somewhat 'inconclusive' when people started looking for background info or testing to see if things can actually happen that way.
Technically speaking the flaw is that its harder to kill yourself with DC than it is with AC. In order to induce fibrillation with DC you need .3 Amps which your typical 9 V battery isn't designed to handle.
EDIT:
If I remember correctly from my biomedical instrumentation book the current required to cause ventricular fibrillation bottoms out at around 60Hz and then starts rising as you go up and down in frequency.

Terrible Robot posted:

Nope, you get to spend whatever time you have left (seconds or days depending on how unlucky you are) in intense agony.
I remember reading a story about a poor guy that got arc flashed and lived long enough to drag himself over to some coworkers in another room and tell them that he had "screwed up real bad" before dying.

Arc flash is the main reason I don't gently caress with electricity more powerful than a vehicles 12v system.
I wouldn't gently caress with car batteries that much either though because even though you won't necessarily create an arc flash there is still a dangerous amount of power there.

MadScientistWorking fucked around with this message at 20:58 on May 13, 2014

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


kastein posted:

Apparently it's documented in some navy accident report somewhere, and I saw some idiot at my college go away in an ambulance with my own two eyes after they hosed up wiring the heart monitor project (and then tested it without having the TA look over their wiring, as they were supposed to) in a microelectronics I lab, which was only powered off a 9V battery, so I'm gonna have to disagree.
Yes but I know precisely where the flaw in your logic stands that makes my original point completely valid.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


kastein posted:

Please enlighten me then.
Well it primarily comes down to reading comprehension in that I said it didn't happen as it did in the story as your calculations are ridiculously under estimated the resistance of a human limb. Even being completely generous with the values most commonly cited your about 70 times off making it next to impossible to generate the current that way.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


Motronic posted:

It seems more like it comes down to your complete inability to express your thoughts in a meaningful way.
No I was actually quite clear. As described in the story its pretty much impossible. The resistance from hand to hand is about 300 ohms. The current needed to generate fibrillation is about 300ma. The voltage needed is roughly 90 Volts DC.
EDIT:
As for the example he cited here is the major difference. Your typical EKG electrodes are placed across the chest. We ignore skin resistance because EKG electrodes are supposed to remove that effect if you apply them correctly. Now the resistance is about 50 ohms which gives a current of about 200mA directly across the heart.

MrChips posted:

Impulse magneto

Oh God that reminds me of a stupid game we played when I was getting my private pilot license in the Air Cadets. The flying school we used had a cutaway Lycoming O-320 (the same engine as in most Cessna 172s) that had a live magneto attached to it. So being a bunch of stupid teenagers we'd get four guys to grab an ignition wire and a fifth to hand-crank the engine until someone had received enough shocks that they cried uncle or dropped their wire.
I think the scary fact is that the actual safety documentation that we are all basing this discussion more or less was this.

MadScientistWorking fucked around with this message at 15:38 on May 14, 2014

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


kastein posted:

Well I'm finding electrical conductivities of blood and body tissue in the 0.16 to 0.5 siemen per meter in published literature, which works out to approximately 4 to 7 ohms from fingertip to fingertip assuming that a person is just a giant sack of blood. Clearly this is not true, so multiply that by ten or something.
The part where you are failing horribly at is the fact that we aren't giant bags of blood. Its the major disconnect where your argument is falling apart.

MadScientistWorking fucked around with this message at 15:43 on May 14, 2014

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


MrYenko posted:

I think I just heard kastein's head explode.
What? That really is the major problem with his argument. I've never seen anything remotely close to his cited statistics in terms of electrical resistance of limbs.

(USER WAS PUT ON PROBATION FOR THIS POST)

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


This is the scariest mechanical thing Ive come across in a while. The tracks look like cooked spaghetti.
https://www.youtube.com/watch?v=MUCU2GhG8zE

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


tater_salad posted:

Magnesium burns like a fucker once it starts.
Yeah I remember reading about how you are supposed to use sand buckets and chemical extinguishers because the reaction with water results in flammable hydrogen gas forming which is dangerous. Technically speaking the light's fairly dangerous too as it gives off UV light.

MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


slothrop posted:

they dyno'd the 5.0 in the latest engine masters episode. It makes power.
Is the issue with the Rotsun that whatever ancillary stuff besides the engine just not capable of handling the power?

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MadScientistWorking
Jun 23, 2010

"I was going through a time period where I was looking up weird stories involving necrophilia..."


H110Hawk posted:

Load bearing zip ties.

(Their general answer to that car is to take a rando cheap engine, add a giant blower, and see how long it takes to blow up. Note that none of that involved work below the valve cover gasket.)
I meant with the last three episodes where the engine worked fine and delivered 500HP but everything else snapped into pieces.

BigPaddy posted:

Only reason the Rotsun keeps coming back is everyone wants to see them suffer to do stuff to it since it was unsavable when they got it with all the rot.
There is something entertaining about them taking a hunk of junk like that and seeing how much power they can generate.

MadScientistWorking fucked around with this message at 15:29 on Jun 23, 2017

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