Groda posted:

OBD monitor?

Sagebrush posted:

That's a real good pilot. He/she put the wheel on the ground and then kept the plane hovering in ground effect, with the majority of its weight still supported by the wings, for a full ten seconds. You can see the transfer as the torque link folds up. Textbook technique for landing on a soft field or when you have an uncertain landing gear condition

Suspect A posted:

Just in. Someone filled my phenolphthalein bottle with hydrochloric acid. Nothing bad probably could've happened but wtf dude.

Tim Thomas posted:

Is, uh, this the place where I post about plasma chemistry and the various dumb things I have seen/done working in semiconductor ion implant/etch and other plasma reactive processes?

Tim Thomas posted:

gently caress, sorry, mashed post instead of writing. Ugh.

I’ll start, most of these aren’t too horrific but some are really not great. I did semiconductor capital equipment for about a decade after college as an electrical engineer, process engineer, and general jack of trades in making ion implanters and etchers and other similar plasma things.

vacuum properties affect a whole bunch of things for particle transport in an ion implanter, plasma fractionation etc. In an implanter, since you’re typically getting wafers coming into the vacuum system with wet photo resist, one typically rolls cryogenic pumps near the water. This is because the photoresists are typically hydrocarbons, and smashing a particle beam into the photo resist tends to liberate the hydrogens rapidly, and pumping hydrogen rapidly with a turbomolecular pump is a losing game, so instead you just freeze the drat stuff with a helium cooled cryopump. Once you run out of physical freezing space, you valve the cryopump off and heat it up to “regenerate” it before cooling it down again. This is all fairly obvious 101 level “here is how it works” poo poo for those in that particular section of the industry.

I had been out of college for about 5 weeks when I got assigned to help a physicist named John with a project of his to help improve particle beam efficiency. You see, making things go faster means less cost and so saving a percent of time on a given wafer meant tens of millions of dollars of potential added revenue, so every second counted. John wanted to add all sorts of gasses into the particle beam as it was being accelerated into the wafer to try to make this better. I obliged and gave him a nice, controllable flow controller that could be hooked up to a bunch of small lecture bottles, and told him to run inert gasses only.

I came in one morning and the machine was open and all the cryopumps were off the machine. The vacuum containment shells had huge bulges in them and the techs looked absolutely bullshit. John came in just around then and triumphantly said that he had improved the beam by 1% better than inert gasses! He had run a bunch of oxygen into the beam and it worked perfectly.... forgetting that when the pump got regenerated, he had managed to combine oxygen and hydrogen basically in a 50-50 ratio, and a standard regeneration added heat to the system.

To his credit, John took the position that his job was to improve the beam and nobody said anything about not making bombs in the equipment.

Tim Thomas posted:

when i was younger and thought that moving up the corporate ladder was likely to be done via working double shifts while salaried exempt with no OT (ie: a loving moron), i became the person who the managers would be like, "poo poo's hosed, tim thomas will probably know wtf and fix it, it's 430pm and we're goin home", which is sort of a badge of honor even though my reward that year was being one of the only recent college grads not laid off and a $125 dinner reimbursement attaboy from the CEO that finance would later reject because i had the temerity to buy wine for me and my now wife

anyway, the first machine that i had a major part in designing was about to leave to go to korea and we were incredibly time-constrained, and of course, of loving COURSE a technician damaged a bunch of connectors in a harness that absolutely, positively cannot be removed from the machine without it taking 24 hours (!) to replace the harness

i'm there figuring out how to fix the harness in-situ after having asked, repeatedly, whether the machine had been decontaminated after the 48 hour phosphine burn-in and been told yes

i put my head in the vacuum chamber and immediately get a huge whiff of garlic, at which point i pull out and immediately start just loving screaming at my bosses while feeling very nauseous; my bosses begrudgingly made the decision after to pull the harness and replace it

and because i am loving dumb and it was 2009 and i was convinced i was going to get laid off if i reported it, i never reported it

Tim Thomas posted:

although this wasn't strictly a chemistry issue it will be relevant in a later story

one of the machines i built had a really odd design; it had a 6 x 3 x 3 m vacuum process chamber [ed's note: this is loving giganto!] that had a smaller 1.5 x .5 x .5 m chamber inside it, like a russian doll or something. the only difference is that the big vacuum chamber had vacuum inside it, and the small chamber actually had atmosphere inside it, and the small one moved around on a gigantic 4 x 1 m XY stage. The small chamber had atmosphere in it because we were entirely too lazy to figure out how to cool the gently caress-off amount of electronics inside, and that design was actually significantly cheaper (!) than just running long lengths of process-rated, vacuum inert cabling.

separately, one of the things you learn about in vacuum equipment is in how to chase the inevitable vacuum leak. unlike chasing a leak on a pressurized pipe, you can't just look for the hiss or for soapy bubbles or a flame or whatever. your options are to shoot a tracer gas at all the sealing surfaces and monitor the vacuum pump molecular concentrations to see where you get spikes (traditional leak checking), or you fill your chamber with gas and use a sniffer on the outside surfaces (sniffing). Sniffing is like six orders of magnitude less sensitive on a good day so you really only want to use that if you're totally hosed.

I had gotten moved onto another project a few months later, and one day i'd ambled by that machine to another one of my machines. I saw a tech and an engineer with a helium tracer bottle and i thought nothing of it but a minute later i heard an awful, ear-shattering boom followed by the screech of four turbomolecular pumps turning themselves to shredded confetti. I ran over and mashed the EMO and made sure people were ok, before seeing that the:

- helium bottle was hooked up to the CDA line feeding the small chamber
- the two redundant relief lines coming back from the small chamber were plugged
- the pressure relief on the CDA line was removed

apparently they had been chasing a leak and thought it was the inside chamber but couldn't find it with the sniffer, so they figured they'd fill it with helium and see if the vacuum on the big chamber spiked


so that's bad with boyle's law or what have you, BUT, the denoument:

typically what had happened would have been fireable but the engineer, who i actually really respected, kept swearing that he had kept the regulator at .5 atmosphere gauge (1.5 atmosphere absolute), and because i felt somewhat responsible, i got involved with the what the gently caress investigation, and found that the mechanical engineer had barely met a 1x safety factor using grade 8 bolts, and at some point they had been replaced with stainless steel bolts due to process compatibility reasons, so we calculated the yield strength of the inner chamber to be subatmospheric

so i'm guessing the leak was in fact the small chamber, way to find it, Dan!

Tim Thomas posted:

the bigger problem here was that having exposure to vacuum in this case isn't so much vacuum as AWFUL loving PLASMA poo poo, which we will now get to in the next story

so this big chamber system was unique because it ran a lot of things that were at the junction of etching and ion implant (think Reactive Ion Etching but with a fuckload more grunt on the ion energy). the big guys were the usual suspects of silane, germane tetrafluoride, methane, chlorine trifluoride, diborane, and a couple of other oddballs like carborane. we ran just fuckloads of the stuff, and we actually had to plasma react the output of the vacuum pumps and then filter the plasma reactants through an additional oxidizer followed by a charcoal trap to keep us from murdering everyone in the greater boston region in a firey poison cloud

the system had been running for about a month when the XY stage decided that moving in X was no longer something it wanted to do. i gowned up in a full hazard suit and PAPR and went into the chamber and found that the entire motor bearing was frozen. I then found that the grease, which previously was, you know, grease, was now rubber cement. Every other surface, on the other hand, was teflon slick.

Discovery: while fluorine reacts with most things to deposit a slippery coating, apparently pennzane and other cyclopentane greases react with elemental fluorine to become glue!

this is around the time that i started to think that maybe i should be doing more plasma chemistry than engineering because it's more loving bonkers.

Tim Thomas posted:

one of the ways that we tried to use ion implant was for photovoltaic production. we were trying to do maskless by focusing the poo poo out of the beam electrostatically, which Was Never Going To Work and thus Would Never Be Cost Effective but whatever, job's a job.

as we were developing that process, there was an interrim process that just had a literal physical mask that would get blasted with just a bonkers amount of phosphorous dopant, generated off of a phosphine bottle.

typically this wasn't a huge deal since you can prevent the phosphorous build up by running an inert purge over the vacuum pumping surfaces.

one day, a customer's vacuum pumping system *was belching fire constantly* every time they did a venting cycle. one of my reports got tasked to go figure out wtf.

bad news: the customer had been concerned about the cost of inert nitrogen being "wasted" on the purges and had capped them off, allowing the vacuum pipes to basically become almost solid with phosphorous buildup
worse news: the customer had been concerned about the cost of inert nitrogen being "wasted" on bringing the vacuum chambers back up to atmospheric pressure and had instead plumbed it to an air compressor, figuring that CDA is ~80% inert.

Tim Thomas posted:

One of the other awful things about semiconductor is disposal, especially when you haven’t thought of how to dispose of things.

Vacuum chambers typically get coated with basically loving everything, but mostly awful hydrides and fluorine compounds from the gas precursors.

One morning we got a terse email from health and safety saying to evacuate the r and d floor and stay away until notified.

A machine that had been running for months without being cleaned had a deionized water fitting let go in vacuum when nobody was paying attention, and the techs came in in the morning to about a 200 liter fishbowl of some horrible stew. I still don’t know what they did with that.

Tim Thomas posted:

One of the fun things about ion implant is that basically every element on the periodic table gets put into it and turned into a particle beam. One of the less fun parts of that is that because it is a particle accelerator, the gas bottle is at potential: a typical gas bottle feeding the plasma source will be riding anywhere from a few kV to five MV over ground. That’s actually not that big a deal, just design the thing with the usual corona rings, make a special gas bottle cabinet that is exhausted and purged, and run special bottles that have the non pyrophorics nasty gasses below atmospheric pressure, and whatever.

This lead to the need to replace gas bottles when they ran out. In certain cases, this was a weekly need. Annoying, sure, but it was minutes of downtime that could be done in parallel with other needed maintenance. One of our customers decided that since etchers had hard-plumbed metallic lines running, implanter a should too, and as sales was terrified of losing a sale to a competitor, of COURSE we can run dedicated high pressure arsine, boron trifluoride, germane terrafluoride, silane, and phosphine to the machines!

In the same purged lines!

In a seismic area!

DrHammond posted:

I'm not even sure what half of what I just read was, but goddamn if I didn't read and enjoy every word of it.

DrHammond posted:

I'm not even sure what half of what I just read was, but goddamn if I didn't read and enjoy every word of it.

200L of toxic stew, I'm losing it over here. I'd blow a loving gasket if someone dropped that in my lap.

Vincent Van Goatse posted:

I asked that dude about chlorine trifluoride and he said "oh yeah, use it all the time, not that bad really".

Groda posted:

OBD monitor?

Cartoon Man posted:

https://i.imgur.com/YZk93bw.mp4

Cartoon Man posted:

https://i.imgur.com/YZk93bw.mp4

SeaborneClink posted:

Does this count as some truckfuckling? Truck stop shirts are the best.

SeaborneClink posted:

Does this count as some truckfuckling? Truck stop shirts are the best.

twistedmentat posted:

I think they're trying to say that tailgaters will be killed and turned into fertilizer, but it sounds like they're gonna get impregnated by a truck.

Mr. Apollo posted:

I thought it was they're going to be sprayed with cow manure because the truck on the shirt is pulling a livestock trailer.

Tim Thomas posted:

when everything you work with is hilariously toxic/violently explosive/hypergolic it gets hard to get really jazzed about a particular thing

DrHammond posted:

I'm not even sure what half of what I just read was, but goddamn if I didn't read and enjoy every word of it.

200L of toxic stew, I'm losing it over here. I'd blow a loving gasket if someone dropped that in my lap.

Cartoon Man posted:

Train hauling corn was leaking.

Cartoon Man posted:

Train hauling corn was leaking.

Methylethylaldehyde posted:

Anything involving high vacuum and plasma/ion guns are a magical land of things that will kill you. Like an Australian tarantula wasp, which is also somehow on fire.

"wikipedia posted:

The sting is famously agonizing. Ernie Rider, who was slapped in the face and torso with the foliage in 1963, said:

For two or three days the pain was almost unbearable; I couldn’t work or sleep, then it was pretty bad pain for another fortnight or so. The stinging persisted for two years and recurred every time I had a cold shower. ... There's nothing to rival it; it's ten times worse than anything else.

"Curiosity posted:

One ex-serviceman, Cyril Bromley, fell into one of the plants during WWII training exercises, and he ended up strapped to a hospital bed, "as mad as a cut snake." Bromley also told a story of an officer who unknowingly used a leaf as toilet paper. He ended up shooting himself. Botanist Ernie Rider was whacked in the face, arm, and chest in 1963, and it wasn't until 1965 that he was finally free of the pain.

If you're stung by the plant, you can't just pluck the needles out with tweezers. They're too fine and too dense — one of the best solutions is to rip them all out at once with hot wax, like the world's worst Brazilian. But be careful. If any of the hundreds of stingers stuck in your skin breaks off, you're in for years of pain. Researchers have even reported being stung by dried leaves stored away for a century.

Hurley's three years in the Australian rainforest (which she spent in heavy protective clothing and welding gloves) ended in hospitalization, a severe allergic reaction, and a medical recommendation to never come into contact with the plant again. She was happy to oblige.

Cartoon Man posted:

Cartoon Man posted:

Train hauling corn was leaking.

Unreal_One posted:

I don't even get why the photoshop, the original is insane enough

GnarlyCharlie4u posted:

There are gonna be SO MANY dead deer on those tracks.

Dannywilson posted:

Could you post it? I'd love to see it and don't know what words to put into google for it.

SLOSifl posted:

Don’t worry the next train is filled with loosely packaged wolves

BMan posted:

this looks shopped