My Physical Chemistry lab once had fun with an idiot who neglected to engage the oil pump before switching on the turbo molecular pump.
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My Physical Chemistry lab once had fun with an idiot who neglected to engage the oil pump before switching on the turbo molecular pump.
Oil pump?
We use cryo pumps.
IIRC oil pumps (in conjunction with fancier molecular pumps) are necessary to get a really GOOD vacuum; cryo pumps are good enough for things like lyophilizers but not good enough for high vacuum systems like XPS or whatever.
We work at ~10^-7 mbar, cryopumps work fine for us!
*shrugs* I could definitely be wrong about this - I just remember talking a bit about this with a grad student who needed 10-9 mbar for XPS et al.
Well, XPS works at ultra high vacuum, so that's a factor ~100 lower pressure, so you are probably right ;)
The oil pump gets the pressure low enough so that the turbo molecular pumps can get the remaining molecules out. If you switch the turbo pumps on at normal pressure, the blades shatter.Quote:
Originally Posted by Flixy
Yeah, we also have some pump stages. I'm just not familiar with what an oil pump exactly is, beyond the pumps that pump oil out of the earth, or the one in your car :pQuote:
Originally Posted by Khendraja'aro
This sounds like poor design also, in that there should probably be a sensor or some other mechanism to keep the turbo pumps from being switched on below a certain pressure.Quote:
Originally Posted by Khendraja'aro
I can't speak for Khen, but at universities designs are often pretty basic and sometimes skipping such safeties because they assume nobody working there would be stupid enough to turn it on too early anyway. Though at the setup with turbopumps I worked with the procedure was automated anyway, so it only kicked in when the pressure was low enough. You just set the desired pressure, and wait.Quote:
Originally Posted by Illusions
Well, they had to build a lot of stuff by themselves and, being a University, also had to fight for funds sometimes.Quote:
Originally Posted by Illusions
One of the first offers I got for my final Physics thesis was rebuilding/repurposing an older 2d X-ray machine. It's a bit in the past, but if I remember correctly, it was about examining how crystal structures changed during heating.
The thing was so primitive, I had to use GNUplot to fit the sixth-order power function to the data we get through the RS232 serial bus. It also overheated easily if you didn't watch what you were doing. Also, a full sweep took about 30 minutes, not including the 10 minutes power-up period.
For one of our practicums we had to use some old AFM, that was controlled by an ancient computer that was completely in Russian and the only way to transfer data was one of those old big floppies. It's nice adjusting settings following a guide if you have no idea what the Russian menus and labels mean :p
Hehe, that reminds me of an old confocal I once worked on. Zeiss had made it (it was one of the very first models out there), but hadn't provided software or documentation in anything other than German. :p
But, Illusions - Flixy and Khendra are right, lots of university equipment is either cobbled together or missing safety features. Even if you buy the equipment from a company, universities often get the earliest iterations of a product, long before it has its wrinkles worked out and safety features added. I remember the awful UI on the first real-time PCR machine I worked with, the very expensive mistakes you could make with an early-model rheometer, etc. Universities are the first adopters of most new analytical technology, which means they often have outdated (expensive) machines that still work, but are a bit finicky and easy to screw up.
Came home in time from work on this depressingly dreary summer afternoon and just went nuts in the kitchen. fried pork tenderloin medallions lightly flavoured with honey, soy, salt and pepper; butter-fried apple and home-grown zucchini; an experiment with stiff-beaten eggwhites flavoured with fresh herbs, cooked in a thick tomatoey broth, then lightly fried with the veggies; delicious creamy gorgonzola-blessed risotto... and, finally, a purely experimental chocolate-cinnamon parfait that turned out so parfait that I'm kinda upset I didn't write down the ingredients and the method.
And then we played this fantastic game: http://www.ebaumsworld.com/games/play/202333/
All is quiet and still in our sinful interracial household save for the background-music of the game, and soon I shall go destroy the hobo-stubble. It's a good evening
Elections are coming up here, so there's this website that asks you a bunch of political questions, and based on your answers says which party is closest to you. Also has a section where they give 25 motions from the past cabinet period, again you vote for or against, and compares it to how parties actually voted. Came closest to the party I have been voting for, and was planning to vote for, so I apparently still know which party best fits my views :)
http://arstechnica.com/science/2012/...1#comments-bar
Lampreys are so frickin' cool :heart: :up:
Humans do that too, Minxy, though not always on the same scale. There are many kb level deletion events in a variety of adult cell types.
Boris sums up my viewpoint perfectly, on hearing news of Prince Harry's naked strip-game in Las Vegas being shown in the Sun:
London Mayor Boris Johnson said he had a "deafening indifference" to the publication of the naked photos.
"The real scandal would be if you went all the way to Las Vegas and you didn't misbehave in some trivial way," he told the BBC.
Quite.
A wonderful turn of phrase the man has. Deafening indifference. Love it.
I've been given an invitation to meet Lisa Ann after one of my graveyard shifts next week. I'm finally getting something out of the RNC :banana:
Being a moviestar is starting to pay off :p Went to a music festival last night, for free because I was on a band's guest list, cuz 'my' director is editing their new videoclip. So, that band is pretty huge, tour the world, called Goose. But wgen I met them after the show, the singer walked up to us saying he knew us, haha. That's the world upside down :D
So we're going through X-Men: Evolution again but it's kinda been ruined for me because all I can see is Patrick Stewart in a mansion full of teenaged girls:
http://www.youtube.com/watch?v=UZ_L3b7osx4
:o
Still, great food, great wine, and GW2 coming up in not too many hours :D :D :D
Was an awesome show yesterday!
We gave the cats a bath today. First ever for Guini, not sure about Isabel (since she was adopted at an adult age). They'd both fallen into that "lazy house-cat syndrome", and weren't grooming themselves very well. And they definitely won't groom each other, because they both have that alpha female Queen attitude.
They hated it, of course, but didn't scream or howl. Mostly looked like scared wet rats, trying to grab at anything to get out. My son had tried to wash Guini by getting in the bathtub with her....thinking she'd feel safer. Needless to say, he learned the hard way, and got a little scratched up, even though we trimmed their claws first.
But now they're both clean and fluffy, thoroughly brushed and smelling sweet, napping and purring on heating pads. :sleepykitty: :heart:
Another Happy: discovering that Guini the Cat likes peanut butter. :)
Supporters of James G. Blaine taunted Grover Cleveland, who was said to have fathered a child outside of marriage, with the chant, “Ma, Ma, where’s my Pa?” (Cleveland’s supporters added, “Gone to the White House, ha ha ha.”)
If only we had such catchy slogans today. :o
'My ultimate Ayn Rand porn' works better on a banner than a chant, alas :(
The main poli sci conference, meant to start tomorrow in New Orleans, was finally canceled. The organizers kept on hedging their bets and were still telling people to come until an hour ago. Here's a great quote from a political scientist on the topic:
I see that APSA has included criteria about regional diversity, local treatment of same-sex unions and partnerships, labor union strength, carbon neutrality, and ethnic and racial diversity. Might I humbly suggest that if political scientists want to be taken seriously by Congress and the general public, if would be a good idea to add 'no city located in a hurricane zone during hurricane season'
:noob:
They are making the same jokes about the RNC. Maybe they should focus less time on trying to shove outlawing same sex marriage into the party's theme and maybe try to include some science, for the same reason of holding a convention in a hurricane zone during the peak of hurricane season.
Maybe they want to be gone with the wind.