User:Linh N Le/Notebook/2009/07/30

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To Do

  • Play with ice machine
  • Look for shaker stuff

Ice Machime

  • The electronic ice machines came in yesterday and I have been messing with them since
  • They are set to be @ 3°C
  • They use these "Miracle Beads" instead of ice to absorb the heat
  • We left one on overnight filled 80% with beads with a centrifuge tube with tap water.
    • Today, it is hovering about 6-7°C which Koch thinks is alright
      • The VWR is around 5C
  • The display says its at 3C and using the temp probe we have, the block is 3-4C
  • Things to try:
    • Leave the lid off (Koch's Idea). Makes more of a thermal gradient, perhaps causing the block to work harder and cool the beads all the way through
    • Too many beads, use less beads (Q=mc(delta)T, so if Q is constant, less m = more delta T)
    • Beads + water. The booklet says that this causes the thing to cool faster (1hr instead of 2hrs for beads only)

Trials

  • The removal of the lid did nothing to cool down the sample more (on a bright note, it didn't heat up the sample more)
  • Running the other ice bucket "naked". The cooling surface got down to 0C (even though the display read 7C)
  • Trying something: I put some water from the real ice bucket in the fridge into a tube. The probe said that the fridge water is at 3C. Put the lid on the beads bucket and going to see if the water heats up in about 10mins (if it stays 3C then stuff from the fridge can go in w/o risk of overheating)
    • So I guess the 0th law of thermodynamics is still true. Beads 7C, water 7C
  • With the 2nd bucket, I have allowed it to cool to a reading of 4C naked. I placed the aluminum pan into the 4C Fridge (reading of 6-7C when removed) and placed that into the 2nd bucket. I will see how cold it gets with just pan (closed lid)
    • The display reads 4C and the temperature of the pan (the probe is inside touching the pan with the lid closed) is reading 4C.
  • Next thing to try: beads plus water. Filling the empty pan with about the same amount of beads as the first with ~250ml of h20 (tap, since DI water will eat the Al pan)
    • So far, I've put 250ml of water into the pan. I'm going to wait a while to see if the machine can bring down that water to 3c (my thinking is that there only a set amount of cooling that this thing can do and if you overload it then the min temp is above 3c)
    • About 10 mins in, the display says 7C and the water is at 11C
    • 20 more mins (or so) and the reading is 3C. The water is 4c and when you touch the pan (through the water) its 3c. The top of the pan is 5C
  • Going to add beads to the water pan now and let it recool. Added about 10% less beads than the first one, letting it recool (initial check, the mix is at 9C)
    • Update: the reading is 7 and the mix is about 9
    • The display finally got to 3C. The mix is about 5-6C (Depending if you are all the way on the bottom). In comparison, the beads only is 5-7 (depending how deep you go). The water in the bead only was 7C, so I transferred it to the water one to see if that cools it better (having water as a conduction media over beads and air)
  • The water bucket is reading 2, the bath is reading 3, but the water tube is only reading 5-6 (of course I picked it up like a dummy and tried to measure it, so i will give it a min to cool further and remeasure)
    • Remeasured, the water is 5C
  • Placed the 5C water back into the beads only to test the temp (at this point, Ant has been working with this icebucket and there are alot of samples)
    • Its 7C, the same it was in the morning before we starting monkeying around with it. At least its consistent
  • Added more beads to the water sample so that the amount of beads in each was about the same.
    • Hey! Its still 5C after adding more beads

Results

  • The water bucket keeps the samples 2C colder
    • Possible reasons:
      1. I added water
      2. That particular machine is better (measuring the cold block on the water one yielded 0c and the beaded was 3c)
  • Added water to the "dry beads" to see if it makes a difference
    • The display says 2C (which it had not before) and the soup is 5C. The water tube in there is still 7C.
    • Update, soup at 4c water at 6c
  • Steve Koch 00:40, 31 July 2009 (EDT): Awesome study, great work! So it looks like both of them work the same and if we use water, we can get to 5C? Since the fridge is 5C, I think that's sufficient. Thanks for checking this out! We'll have to remember that if we're every being super-delicate and want closer to 0C that we should use ice water...e.g. when resuspending tubulin.

Shaker

  • Andy wants to clean and find flask holders for out Innova4300 Shaker+Incubator.
  • I found the company website (new brunswick) and they have a nice PDF that shows what accessories are available for the shaker
  • If we want to use 1 and 2L flasks, we can hold ~12.
  • What i've found so far is that we can get a sticky platform to hold down the flasks or specialized braces to tie them down
  • The size of the platform the offer is 30" x 18"(76 x 46 cm)
    • Note: the 4300 is not explicitly listed but it shares the same size platforms as the 43/43r series, so those are what I am looking up
  • For flasks, there are dedicated and universal platforms.
    • Dedicated are for one size only, whereas universal can hold many different things (testube racks too i think)
  • M1250-9920 Universal Platform
    • We would need to buy the clamps and stickypads seperate
    • ACE-1000S 1 L Erlenmeyer Clamp with spring retainer
    • ACE-2000S 2 L Erlenmeyer Clamp with spring retainer
    • M1250-9600ø Sticky Tape (16.4’ x 1.5”)
    • M1250-9700** Sticky Pad, 8” x 8” (20 x 20 cm)
  • AG-1, 1L Erlenmeyer Flask Dedicated Platform, 15 clamps
  • AG-2, 2L Erlenmeyer Flask Dedicated Platform, 12 clamps
  • M1250-9904 Platform for Sticky Pad
  • No prices listed, but when we figure out what we want, a price quote can be submitted
  • Steve Koch 00:43, 31 July 2009 (EDT): I didn't follow all of this. But maybe I can help narrow it down a bit. I have always used spring clamps (a triangle-type springy-thing, I believe. They are quite strong and screw into the platform. We shake pretty vigorously, and I can't imagine using anything less sturdy (such as sticky pad). As for versatility--we definitely will want to do different sized flasks, so that will need to be an option. But whether it needs to be "universal," I don't know. Finally, since you've got that temperature probe going, you may as well check out whether the shaker achieves the correct temperature...that would be great! We're mostly likely to use it at 37C, I think.
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