why do students always reminded not to refill a hot alcohol lamp in a laboratory?
104354
because they don't pay attention and think about what they are doing. i.e. hot lamp + alcohol vapour = fire/explosion risk
1025903
what type you talking about?  If it's wine, you gotta store that at cool temperatures in the dark.  But for other stuff like hard liquor, i believe you just gotta keep it away from open flames :-)
1040306
absolutely... they shouldn't be abused though.. I think it is so rude to have it going off durring school but I also feel you do need it for an emergency!
280406
Talk about one of my pet peeves!  Not to mention it's really frightening to see people who know better (healthcare and food industry workers especially) not doing it!  I agree though, it's pure laziness.  There is always time to wash your hands.
44868
Alcohol Lamp \n-------------\n \nThis glass lamp is for heating tjanting tools.
115844
Some people just don't test well. What works to keep me from slipping into the duh zone is a cup or two of coffee that morning and a peppermint chapstick.\n\nDon't know why, peppermint brings me back to the real world.\n\nDon't know if there is a scientific basis for it, but a $.99 chapstick is worth trying, right?
891018
The white powder is a preservative.  Doesn't have anything to do with your blood alcohol.\n\nThere's no amount they're "supposed" to draw, but there is a minimum amount that has to be drawn to provide the lab with a sufficient amount to test and have enough left over for the defense to have re-tested.  What that amount is will vary by state law, lab policy and maybe even prosecutor's policy.
533755
When I was in college, California was suffering from rolling blackouts (but that's a subject for another day). Well, anyway, we had one in the middle of choir practice. Some of the students tried to convince the director to just let us go home. His response was, "People were making music long before electricity, and so can we."
1003680
The lamp consists of an illuminating bulb, and a glass bottle containing a transparent liquid, translucent wax, and a metallic wire coil. The glass bottle sits on top of the bulb, which heats its contents. The metallic wire coil is hidden in the base of the lamp, which the glass bottle is sitting on.\n\nThe wax is slightly denser than the liquid at room temperature, and slightly less dense than the liquid under marginally warmer conditions. This happens because the wax expands more than the liquid when heated.\n\nThe light bulb heats the container at the bottom, and due to heat exchange with the atmosphere, the container eventually dissipates the introduced heat. This method of heat transfer is called convection.\n\nWax at the bottom heats until it melts, and eventually becomes less dense than the liquid above it. At this time, a portion of the wax rises towards the top of the container. Near the top, away from the heat source, the wax cools, contracts, and as its density increases it begins to fall through the liquid towards the bottom of the container again. The difference in temperature between the top and bottom of the globe is only a few degrees.\n\nOne mass of wax may rise as another falls. The metal coil at the bottom helps to overcome the surface tension of the individual wax droplets, causing the descending blobs to agglomerate into a single molten wax mass at the bottom of the container. The cycle of rising and falling wax droplets continues so long as the bottom of the container remains warm and the top of the container remains cool. Operating temperatures of lava lamps vary, but are normally around 60 °C (140 °F). If too low or too high a wattage bulb is used in the base, the "lava" ceases to circulate, either remaining quiescent at the bottom (too cold) or all rising to the top (too hot).\n\nChaotic behaviour makes the movement of the wax unpredictable—hence lava lamps can aid in the generation of one-time pads for cryptographic use.\n\nThe colour of the wax and the liquid often varies and can be found in many different combinations.
22678
Every quarter, I run a urine lab in my introductory Human biology course.\nAfter everyone gets over feeling uncomfortable by having others see their\nurine, it turns out to be one of the most popular labs we do.\nInterestingly, I usually get at least one female asking me the same\nquestion--quite confidentially. "Why is it that male urine seems to have\nmore bubbles that female urine?"\n\nMy off-the-top-of-my-head response has always been in the method of\ncollection. I suggest that males, perhaps because of greater force, or\ndistance, are able to "blast" the sample and thus create more froth. A\nlogical hypothesis, I thought, but never tested.\n\nI could not think of a very accurate way to test the hypothesis, and still\nmaintain the high standards of our institution and still retain my job. But\nlast week, I figured out a way.\n\nWhen the student returned to the lab with their samples in hand, I asked\nthree males and three females, if I might have a third of a test tube of\ntheir finest for a test I was going to run. They agreed, and the only\nidentifying marks were the classic male and female symbols on the test\ntubes. Each test tube was covered with parafilm, and then each was shaken\n(not stirred) for five times (or 5 "shakes").\n\nAll three of the male samples created 2-4 cm. "heads," while all three\nfemale samples could only muster about 0.5 cm. worth of effort. After\nstanding for 1 hour, the male samples still had about 1 cm. of foam, while\nthe female samples were entirely bubbleless.\n\nObviously, the bubble factor of urine is not due to the method of\ncollection, but shows a definite dimorphic difference. I realize that the\nsample size was small and the experiment lacked the proper elegance to be\nrecorded in a journal. Still, while trying hard not to appear sexist, it\ndoes appear that males are better bubble-makers than females.
487923
I personally think that it's in the student's best interest to taught about how to protect themselves. There should be a message in there about abstinence, though. People have to understand that no matter how much you tell students not to have sex and educate them about the risks, they're still going to do it. The best way to keep them safe is to educate them about how to be the safest they can and not have any life-ruining consequences come of it. If they aren't educated about protection and are only taught about abstinence, the students who decide to have sex regardless of being taught about abstinence will not know how to protect themselves correctly and could end up with an STD or pregnant.
915479
its a bad thing and a good thing. the good is students need it for safety, but the bad is distracting other students or probably even distract the student that has it. if i was a teacher, i would let my students bring one, but not used for inappropriate things like talking to their girlfriend/boyfriend/or some other business. school is a place to learn, not a place to mess around.
547973
used to allow beer in dorm rooms always good\ndon't know if they still do.....
1040696
why the hell do you have a urine sample in your fridge?
474124
either your teacher is nuts or you probably know more about this than us. the bulb has to be a vacuum, and making a glass vacuum requires better equipment than most people have access to.
794712
Speaking as a college professor, I can totally relate.  It's not uncommon for students to "blow off" night classes on days such as Fridays and holidays.\n\nAnd I've personally been in this situation myself.  True, we as instructors don't have control over who shows up to class.  But then again, it is an instructor's job to teach material to any student who is in class whenever class is supposed to be in session.\n\nNow I do know some instructors who will ask those few students who showed up whether they would mind if class was cancelled so material doesn't have to be repeated again next class.  Most times, students are OK with this.  But other times, there's someone who isn't.\n\nIn my professional judgement, I say that if a student wants to stay, and class is officially scheduled to meet then, and school is officially in session, then it's the job of that instructor to be there and hold class.\n\nWhen I've been in this situation, I would generally decide to use that time to further review and clarify past material, give additional exercises and practice, possibly "switch" some things around to adjust for there being so few people so I don't have to repeat myself again, and perhaps introduce something new with more examples rather than lecture.  \n\nMy point is this, if students choose not to show when class is supposed to meet, then that's the students' loss!  And it doesn't matter what day it is, holiday or otherwise.  And it's the job of an instructor to provide instruction to any student who wants it.\n\nIn your particular case, you did not want class cut short because of your classmates' decision to blow it off.  But you can't blame your instructor for doing this considering the situation--so few there possibly making it extremely difficult to conduct class.\n\nI would have stayed for those who came, but most likely have rearranged my plan around there being so few students present.  If all agreed that it's not worth holding class under this circumstance, then I would dismiss them.  But for anybody who wanted to stay for class, I would hold class for their benefit.  After all, I'm there for the students, and you made the effort to come to class and take your work seriously--commendable!!\n\nNo harm in voicing your complaint, but please do realize that depending on where your instructor was, it could have been pretty difficult to hold a class with so few people being there.  Had your instructor summarily dismissed all of you, you would have a stronger argument, but your instructor did stay for a while to instruct the class.  Cutting short say 5 minutes isn't a big deal, but cutting short 30 minutes could be.\n\nEither way, it's more of a judgement call on the instructor's end, and some would send their students home, while others like myself will stay for the benefit of those who showed up.
1054526
For no good reason.\n\nFor example, suppose you worked in a laboratory.  Would you actually need to know what any of the instruments were for or how they functioned?  \n\nOf course you wouldn't!  You could just grab any random object, fill it with some sort of fluid and add some other stuff to it, and put it in a machine.  Then take it out a while later, and use your psychic powers to tell you the result.\n\nWhen asked to report the results of your work, you could say, "Bad news, Mrs. Johnson has AIDS", or "I've found the cure for leprosy!", or whatever else came to mind.\n\nSo, as you can see, basic familiarity with laboratory instruments is totally unnecessary for laboratory workers.