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Phanatic fucked around with this message at 19:30 on Mar 21, 2017 |
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Mar 8, 2016 06:04
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TotalLossBrain posted:I wasn't commenting on the goodness of requiring fume hoods for soldering, only that it is indeed required. I can't find anything supporting this as a requirement. There are requirements for maximum allowable concentrations of things like lead, toxic fumes, etc., and you might need to have a fume hood or other ventilation to keep the concentrations below that limit, but I don't believe fume hoods are a requirement. I mean, I used to solder outdoors all the time, a fume hood requirement would have been impossible to meet.
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Mar 8, 2016 20:59
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Three-Phase posted:Man that's gonna cost at least several thousand dollars to fix, isn't it? My friend's having the engine in his Cessna rebuilt (it's old enough that it's just that time). That's a $20,000 job, even before they found a crack in the crankshaft which adds another $4000. When you pull the big red handle to deploy that chute, you total your airplane, even if it lands in a really big poofy pillow. At the *very* least, the gear are toast, the seats are a collapsing aluminum honeycomb so those are all ruined now, and there's a solid-fuel rocket that just fired out of the airplane's tail. A chute deployment is a job for the insurance adjuster, not the mechanic. Airplanes are *really expensive*. It's worse than boats, and you know what they say about boats: Don't own a boat; have a friend who owns a boat. (It is a damned nice airplane, my friend with the Cessna has one and I was just up over Sedona in it.) 
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Mar 10, 2016 03:20
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For a second I thought this was a modified dumpster-collecting trash truck, and thought hey, that's pretty clev-oh my god.
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Mar 10, 2016 19:29
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Nierbo posted:Got my toe run over by a pallet jack at work the other day. Took the big toe nail off. First two pics are a few mins after it happened and the last pic is just an hr ago after I took the dressing off for the first time. I hope that grows back right for you. I had a toenail inadvertently removed during a surgery to deal with the fact that it was massively ingrown on both sides (runners, you know what I'm talking about), and it grew back as a twisted feeble thing that occasionally pops right back off again when I take my sock off.
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Mar 11, 2016 04:04
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GirlBones posted:It's true that MSHA are major sticklers but IIRC ~30 people died in mines in the US last year compared to like 1,000 in construction so... How many people work in mines compared to how many work in construction? 14.2 fatalities/100,000 full time mine workers: http://www.cdc.gov/niosh/mining/UserFiles/statistics/13g09aaa.svg 11.8 fatalities/100,000 full time construction workers: http://www.bls.gov/news.release/cfoi.nr0.htm
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Mar 11, 2016 04:19
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TotalLossBrain posted:If the criticality is energetic enough, it will produce Cherenkov radiation. It's like a sonic boom, but for energetic particles. The particle in question will travel faster than the phase velocity for the medium it is traveling in. Cherenkov radiation doesn't have to do with how supercritical something is, it happens when charged particles travel faster than the speed of light in a medium. The blue flash during Slotin and Daghlian's accidents with that core weren't Cherenkov radiation, because the particles in question aren't traveling fast enough in air to do that. It was just straightforward ionization of the air in the room. Which is plenty bad enough.
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Mar 15, 2016 01:27
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Kilo147 posted:If you had a suit of motorcycle helmets, yes https://www.youtube.com/watch?v=-jYwQacBdGw&t=12s
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Mar 23, 2016 21:07
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Hot Karl Marx posted:he's also a job creator cause now people have to fix that bridge 
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Mar 24, 2016 16:47
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Bistromatic posted:I don't know what kind of missile that is but the plume very much looks like a solid rocket motor. I'm guessing the missile has a solid first stage/booster that misfires and immediately detaches, at least part of it is then lodged at the edge of the deck and continues burning. So lucky for them they only have a giant firework going off on deck and not the actual ship burning Sea Dart.  And, yeah, that's exactly right: solid-fuel booster first stage, kerosene/air-burning second stage, and that's what it looks like when a solid fuel motor has cracks in it and breaks apart and spills burning chunks of rock fuel across your deck. Some minor damage to the deck/antiskid coating, other than that no big deal. http://www.military.com/video/guided-missiles/sea-launched/sea-dart-gone-wrong/658292598001
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Mar 29, 2016 18:52
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(at least for the duration of the video)
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Red Suit posted:So one of our machines has been leaking oil and the solution the workers decided on was to put a bucket under the leak. Then when the smell of oil got to be too much to bear, the supervisor brought in a box fan to point at the bucket. Thing is, those fans have motors that can spark. Basically the supervisor rigged a loving bomb without knowing it. Lubricating oil? Hydraulic oil? Both aren't particularly volatile or inflammable.
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Mar 31, 2016 17:22
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Kilo147 posted:People overestimate the risk from radiation constantly. With a simple dust mask I could hold a half pound of Uranium indefinitely with absolutely zero risk. It's actually on my bucket list. You wouldn't even need a dust mask.
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Apr 1, 2016 20:07
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The hazard from uranium is primarily that it's a toxic heavy metal, its chemical toxicity far outweighs its radiological activity as a matter of concern. Even if it were pulverized and inhaled/ingested, it's a pretty innocuous decay chain and while you definitely don't want to inhale/ingest alpha emitters, you'd be far more concerned with its chemical activity on your kidneys.
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Apr 1, 2016 20:47
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Kilo147 posted:Uranium sheds when exposed to air, I thought. Alpha particles are the one I don't want in my system. You may be thinking of its pyrophoricity, but a lot of metals are pyrophoric and they don't burn when they're big solid blocks sitting in the air. Lead is pyrophoric, but you can hold a block of it in your hand without ending up with a lungful of toxic crud. Or maybe you're thinking of its oxide coating; the metal will form an oxide when exposed to air, but it's a non-protective layer like iron oxide that will flake off, not a protective layer like aluminum oxide that won't. But again, that doesn't mean it's going to shoot bits of itself off into your lungs, it's just a metal. Handle it like you'd handle lead, pretty much. Raygereio posted:In case people don't know: The isotopes of uranium that are found in nature all decay by releasing alpha radiation. Which can be stopped by a few centimeters or air, a piece of paper, or your skin. It's not just the parent isotopes you have to worry about, though, it's the whole equilibrium decay chain. In a lump of natural uranium you're inevitably going to have some bismuth, some polonium, some lead, and some other things that decay by beta emission, but they're present in such small amounts that, again, the chemical toxicity of the parent is far more of a concern. Phanatic fucked around with this message at 21:25 on Apr 1, 2016 |
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Apr 1, 2016 21:21
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As always I'll point out the real OSHA here, because the description's wrong on the Youtube video. This wasn't an intentional ground resonance, the airframe had been damaged and the Army was going to use it in a weapons effects test. They did this on their own, without getting any help from the Boeing engineers, so they didn't involve anyone smart enough to say "No, don't remove the oleo struts and chain it directly to the ground because then it will go into ground resonance and shake itself to pieces before you get a chance to actually do your testing." The real OSHA is how the airframe got damaged in the first place: quote:The PC, who also was an IP and MP, was on the flight controls when the nose of the aircraft began a slight pitch down. He applied aft cyclic to correct for what seemed to be a normal divergence in the CH-47. But as he applied aft cyclic, the nose began a slow left yaw that he could not control with full right pedal. The aircraft then began a slow left roll to about the 90-degree point and then continued with what seemed to be a snap roll through the remaining 270 degrees. But it didn’t happen that fast; it felt like eternity to the crewmembers. As the aircraft inverted, the PI, figuring he had nothing to lose, joined the PC on the flight controls. (I am not advocating that two people try to fly an aircraft, but this action confirms that both pilots knew they were in a desperate situation.) Instinctively responding by doing what they had been trained to do, the pilots continued to fly the aircraft even as they saw the ground through the greenhouse and it appeared there was no hope of recovering control of the aircraft. The cause was eventually traced to water and rust in the actuator hydraulics.
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Apr 5, 2016 16:57
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Platystemon posted:Conspire to violate federal mine safety standards resulting in the death of 29 people? Get a whole year in jail. Compared to what 9/11 conspirator Mounir El Motassadeq got sentenced to in Germany, that's positively draconian.
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Apr 7, 2016 02:44
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DONT CARE BUTTON posted:I have a friend who is a middle school teacher and doesn't keep any hand sanitizer in his classroom Good. That poo poo's literally worse than useless. It makes strep more infectious, breeds resistance, and doesn't get your hands any cleaner than just rinsing them with water.
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Apr 14, 2016 19:37
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quote:Scientists report that common antibacterial compounds found in those soaps, namely triclosan and triclocarban, may increase the risk of infections, alter the gut microbiome, and spur bacteria to become resistant to prescription antibiotics. Meanwhile, proof of the soaps’ benefits is slim. http://arstechnica.com/science/2016/04/mounting-data-suggest-antibacterial-soaps-do-more-harm-than-good/
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Apr 15, 2016 00:11
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Given how often forklifts are used to carry loads so large that the operator can't see past/around/over them, and needs to drive the forklift in reverse, why are rotating or dual controls not standard so he can better see where he's going instead of driving hundreds of yards looking over his shoulder?
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Apr 19, 2016 16:49
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wdarkk posted:I'm not so sure you can claim modern planes aren't robust. Yeah, it's way too complicated an issue for a blanket statement like that. Air-cooled piston engines were insanely robust, it was routine for piston-engined aircraft to make it back to base with multiple cylinders destroyed but the engine still functioning (it also helps to have such an enormous oil reservoir that it can operate for a while as a total-loss lubrication system). On the other hand, water-cooled engines that took even a single round or fragment in the cooling system tended to stop working pretty damned quick.  There was some robustness that came from simplicity. Like, the B-17 had no fancy hydraulics or anything like that, the controls were cables that extended from the yokes back down the fuselage and out towards the control surfaces. So there's nothing in the way of miles of hydraulic tubing to damage, but there's also no multiply redundant hydraulic systems where one can take over it another gets holes shot in it. A lot of a B-17 is empty space, rounds go in and go out without having a high likelihood of hitting something vital. But that can happen today, too.   That aircraft made it home. Mycroft Holmes posted:What's most interesting is how damage from returning planes factored into improvements. Engineers would look at the planes that came back and notice where they had been hit. Then they would armor all the sections that hadn't been hit because those sections were so important bombers hit there wouldn't come back! That was actually primarily the brilliance of Abraham Wald. They'd station an unused bomber at an airfield, and whenever a plane made it back with damage they'd paint a dot on the unused one wherever the real plane had been damaged, so they basically turned the unused plane into a scatterplot of where the survivors had been damaged. His paper on probability of aircraft damage is almost the start of the entire field of operational research.
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Apr 19, 2016 20:27
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Gromit posted:Isn't there an old boat sunk up the Thames somewhere that is chock-full of explosives but it's too expensive to clear? Hell yes. https://en.wikipedia.org/wiki/SS_Richard_Montgomery For more fun: https://en.wikipedia.org/wiki/Operation_CHASE
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Apr 20, 2016 00:11
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goddamnedtwisto posted:Most nuclear plants are pretty much self-running and fail safe by design. A lot has to go wrong for really bad things to happen, but in the event of "everyone disappears" nuclear plants are going to be proper hosed pretty quickly. Remember what killed Fukushima: Power failure due to the quake cut off electrical power to the plant, and they couldn't restore power in time to prevent a meltdown because the tsunami flooded the backup generators. Everyone disappears, that mean the electrical grid feeding the nuclear plants external power to keep its systems operating are going to stop doing that. Plant will SCRAM automatically, but the backup systems need to keep it cool while the decay heat drops below dangerous levels. Probably not going to work in all cases. And there's also the used-fuel storage. The dry cask stuff will be okay for a long time, but the stuff in the spent fuel pool? Water's going to stop being added to the pool to make up for that lost through evaporation (and again, eventually the cooling system will stop working and rate of evaporation will go up a lot) and eventually those pools are going to empty.
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Apr 21, 2016 22:32
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Boat posted:It escapes the freeze/thaw damage, sure, but it's still got water erosion to deal with, whereas Dubai kind of doesn't. Water by itself without the freeze/thaw is going to take a loooong time to damage concrete. The concrete setting process is actually a hydration reaction, it's pretty standard after a big pour to lay down burlap over it and set sprinklers on it to keep it wet, both to cool the exothermic reaction and the provide an excess of water for the surface layer to react with. Hoover Dam is such a big set of pours that it's still curing today, and actually becoming stronger.
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Apr 22, 2016 02:13
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Budgie posted:https://www.youtube.com/watch?v=PmvKlnhMjUw Jesus, that brings me back. David Letterman used to do that on his old TV show on NBC. https://www.youtube.com/watch?v=vakVgkNRL94 And stuff like this. https://www.youtube.com/watch?v=c5spRGiakb0 It was much better than his later work.
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Apr 24, 2016 04:19
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mostlygray posted:
It's David Letterman. He survived unharmed. I don't think they had laser interrupters in 1986.
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Apr 25, 2016 04:40
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Zero One posted:When a teenager was killed by Batman: The Ride at Six Flags Over Georgia, the ride was closed for weeks (maybe months??) and Six Flags installed new warning signs on ride fences across all their parks. Without information about the failure mode, that contrast between the two cases is meaningless.
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Apr 30, 2016 17:42
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Lathespin.gif posted:Niiiiice. And that's why we don't go to Ravenholme anymore.
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May 3, 2016 19:12
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Explosionface posted:I'm reasonably sure that Ignition! is public domain. There's no reason I can see that it would be. It was published in 1972, copyright term is life of the author plus 70 years, he died in 1988, unless whoever held the rights after his death placed it into the public domain it's going to be under copyright until at least 2058 (and effectively forever since whenever the copyright's about to lapse on the mouse they'll just extend it again).
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May 10, 2016 05:13
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IPCRESS posted:You aren't seriously suggesting that curtain rod and bailing wire pushrods aren't an appropriate control synchronization method, are you? https://en.wikipedia.org/wiki/Piasecki_PA-97
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May 10, 2016 17:14
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Mosnar posted:Electricity travels primarily along the outside (surface) area of the wire. Said wire is now de-rated .. Skin depth in copper at 60 Hz is almost a centimeter. All that wire is carrying current.
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May 12, 2016 22:36
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Jabor posted:You'd think a basic safety procedure would be to have some sort of load attached to it, so that if it starts to run away you can channel that torque into something that isn't "accelerate beyond rated speed". Accelerating beyond rated speed is what a runaway entails, it's sucking in its own engine lube oil for fuel. Doesn't matter much if it's loaded or not, it's going to overspeed until it fails, seizes, or you cut off its air supply or compression. If it's loaded it'll just take longer to get there, except now it's also accelerating the load which is probably even more dangerous. Like if your freight train's prime mover starts running away you sure as hell want to decouple it from the load so it's not driving a train down a track at increasing speed. https://www.youtube.com/watch?v=r6komyj6AWA
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May 17, 2016 16:58
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ReelBigLizard posted:Best practice when working on old diesels is to have something that can quickly and easily block the air intake(s) completely. A piece of wood will do, even a damp rag to stuff in the throttle body, but have something ready. Another option is to block the exhaust or even, so I have heard, crimp the exhaust by bending or crushing it. CO2 fire extinguisher into the intake.
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May 17, 2016 17:30
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Deteriorata posted:When I was a kid, a worker at Dow Chemical fell into a vat of hot caustic soda. He dissolved completely. Guy I knew did his metallurgy thesis on what happens to a batch of steel in a Chicago steel mill if someone falls in and burns to death floating on the surface. This was a while ago, when Chicago still had steel mills.
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May 19, 2016 21:08
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GopherFlats posted:So uh... what happens? I would assume the whole gets thrown out because its contaminated or do they just label it as A36 or some other low grade and sell it on the cheap I didn't read it, it's probably in some hard bound copy buried in a cardboard box in his basement or attic like most pre-Internet theses. Molten steel's going to be waaay denser than a person so he'd float around on top like a cork in mercury, but it's also hot enough to vaporize most of him. So maybe not a whole lot. And of course the steam explosion's going to be throwing molten steel everywhere. Kind of like this except with a person: https://www.youtube.com/watch?v=kq7DDk8eLs8 I guess the legal concerns would outweigh the metallurgical implications.
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May 19, 2016 22:23
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tater_salad posted:Plus who would ever accidentally press the start button while they had ahead in there right, not like that'll ever happen. I was working a test program some years back involving testing some acoustic isolation mounts for submarines. One test sequence used a drop tower, just dropping weights on the thing to generate increasing loads while measuring strain output, accelerations, etc. The next test sequence involved mounting the unit horizontally so a big horizontal hydraulic ram could apply a steady and controlled load. At one point, just after reaching into the arrangement to adjust some wiring, something failed and the hydraulic ram instantly slammed out to full extension, and then lost all pressure. No idea what happened, it wasn't our facility (we were just their to administer the testing for them), and we weren't operating it. Maybe an accumulator was overpressure and vented into the actuator or something, but I can't think that "go to maximum extension *right now*" is ever an acceptable failure mode. If it had happened three seconds earlier, I'd probably have lost an arm. The test unit, HY100 steel, was *cracked*.
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May 31, 2016 19:11
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chitoryu12 posted:That's actually the exact problem keeping any of this from going forward. Not sure what you mean there, unless "any of this" means to the marking effort itself. The Waste Isolation Pilot Plant definitely went forward, it's in operation and accepting waste. Yucca mountain was stopped, but not because of worries about marking it. The panels weren't intended to come to a decision about a design that would actually be built, it was really just a think tank: "If we were going to mark this repository in a way that would last as long as the waste is dangerous, how would we do that?" quote:In the end, the only surefire way to keep cavemen of the year 200,000 CE from uncovering radioactive materials is to put it somewhere they won't find it, like hurling it into space or burying it so deep and secure that only a society that can understand radiation can have the tools necessary to uncover it. And then the report raised the issue: is 'surefire' even something we should be going for? quote:We have all become very marker-prone, but shouldn't we nevertheless admit that, in the end, despite all we try to do, the most effective "marker" for any intruders will be a relatively limited amount of sickness and death caused by the radioactive waste? In other words, it is largely a self-correcting process if anyone intrudes without appropriate precautions, and it seems unlikely that intrusion on such buried waste would lead to large-scale disasters. An analysis of the likely number of deaths over 10,000 years due to inadvertent intrusion should be conducted. This cost should be weighted against that of the marker system.
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May 31, 2016 20:34
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FuturePastNow posted:The best deterrent will be people going in and none of them ever coming back. No, that's an endless chain of people going to check on the ones that haven't come back yet. People who go coming back with melting skin = much better deterrent.
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May 31, 2016 22:46
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Raskolnikov38 posted:aren't the worst decay products no longer an issue after a hundred years anyway Depends on how you define 'worst.' The really-long-lived stuff is so barely radioactive you don't really care about (and in some cases makes up a significant portion of the earth's crust so there's no getting away from it anyway. U-238, thorium, tellurium. Then there are short-lived fission fragments that are fiercely radioactive, but their half-lives are so short you're not worrying about storing them for any length of time . Iodine-131 has a half-life of 8 days, in a few months it's effectively gone. Barium-140, Strontium-89, things like that you only have to worry about for a few years. Then you have the long-lived fission fragments, like Cesium-137 and Strontium-90, and those are going to stay nasty for several hundred years. But it's the actinides in spent fuel that last a good long time, and still are radioactive enough to be a concern. These are primarily alpha emitters, so you get very concerned about them ending up in food and water, and the half-lives there are on the order of hundreds to thousands of years.
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May 31, 2016 23:59
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Syd Midnight posted:Extremely deep boreholes. If you drill them in a subduction zone, plate tectonics will carry the waste deeper and deeper and deposit it the Earth's mantle. I suppose they don't want spent fuel rods to go away forever in case they figure out some new use for them. Most of a "spent" fuel rod is perfectly useful nuclear fuel. We've just collectively decided not to build reactors that burn it.
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Jun 1, 2016 16:14
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AreWeDrunkYet posted:Why doesn't the article name the former owners of the White Swan Cleaners and discuss how the EPA is suing them into the ground? Your questions assume that the the owners are (a) still alive and (b) have enough recoverable assets to make even the slightest dent in what the cleanup costs. If they are alive, filing criminal charges against them is probably more important than a civil suit.
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Jun 1, 2016 20:09
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