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Liquid Nitrogen


falcon9393

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i reccently did a school project on Liquid Nitrogen and i also did a few expirements with it such as making ice cream and freezing a balloon

here are some pics (in the pic is my lab partner Jake and Dr. Warron from GU)

the first one is ice cream

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the second is freezing a balloon

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and this last one is jus LN2 being poured

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but what im wonder is i heard of a decompression sickness called the Benz so any info on that would be great!! also any personal experiences with LN2 or comments or info would be very beneficial!!

 

 

thanx again :)

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Okay... You really need to elaborate on that. My experience with liquid nitrogen has been minimal to say the least, but I KNOW hands cannot be dipped if you don't want them falling off.

 

What am I missing here?

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Your body heat evaporates liquid nitrogen quite fast so, if you dip it quickly your finger does not actually touch the cold nitrogen. Of course it cools down a bit, but you need to hold it in the liquid nitrogen for a while if you want it to freeze.

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My middle school teacher told us a story about his college professor who played a trick during a liquid nitrogen demo. He stuffed the tips of his gloves with hotdogs, and then smashed his hand against the table, breaking the hotdogs. To the unsuspecting class, however, it looked like the prof had just destroyed his own hand. >:D

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Your body heat evaporates liquid nitrogen quite fast so, if you dip it quickly your finger does not actually touch the cold nitrogen. Of course it cools down a bit, but you need to hold it in the liquid nitrogen for a while if you want it to freeze.

 

The same effect that keeps a bit of water off a very hot pan. I'd be scared to try that though. I rather like my hands.

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My middle school teacher told us a story about his college professor who played a trick during a liquid nitrogen demo. He stuffed the tips of his gloves with hotdogs, and then smashed his hand against the table, breaking the hotdogs. To the unsuspecting class, however, it looked like the prof had just destroyed his own hand. >:D

 

One of my lecturers did that to us last semester, he had a girl from the group down the front helping him with the demo, scared the life out of her :D

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The single largest danger regarding liquid nitrogen is probably suffocation. In one institute, shortly before I began my first postdoc there, a student worked in a cold room with a large canister of liquid nitrogen. Apparently somehow he tipped it over (I have no idea whether it was on purpose for playing or due to some kind of accident, but the canister are not that easy to tip over. Long story short, he was found dead next morning. So if you play with larger quantities of it, ensure that there is sufficient ventilation.

Students that I instructed later all believed that he froze to death an freaked out when I poured some over my hands. One (female) student actually started to scream and cry.

 

Good times.

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Students that I instructed later all believed that he froze to death an freaked out when I poured some over my hands. One (female) student actually started to scream and cry.

 

Good times.

 

I haven't laughed that hard in quite a while. Thanks for sharing the story. :D

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Okay... You really need to elaborate on that. My experience with liquid nitrogen has been minimal to say the least, but I KNOW hands cannot be dipped if you don't want them falling off.

 

What am I missing here?

 

It helps to be a complete idiot like me. Do not wash your hands for several hours. Remove any rings. Do it fast.

 

The single largest danger regarding liquid nitrogen is probably suffocation. In one institute, shortly before I began my first postdoc there, a student worked in a cold room with a large canister of liquid nitrogen. Apparently somehow he tipped it over (I have no idea whether it was on purpose for playing or due to some kind of accident, but the canister are not that easy to tip over. Long story short, he was found dead next morning. So if you play with larger quantities of it, ensure that there is sufficient ventilation.

Students that I instructed later all believed that he froze to death an freaked out when I poured some over my hands. One (female) student actually started to scream and cry.

 

Good times.

NASA lost a couple of guys to that in the early 70s. Everybody installed oxygen monitors real quickly.

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OK - When I spent some time at the Rutherford Appleton Lab in Didcot I used the SEM quite alot. This has an automatic Liquid Nitrogen feed which kept the machine cool. Every so often, when the level got low, it wiould automatically start pumping N2 through a pipe from the container next door to fill up the dewer built into the SEM. One morning, there was a new cleaner sent in to mop the floor of the clean rooms there. As she walked into the room containing the SEM the automatic N2 feed kicked in. It makes a hissing noise and you get a load of N2 venting out of the top of the SEM whilst this happens. She mistook the N2 gassing out of the machine for smoke and thought the machine had gone wrong and was going to explode! :D She ran out of the clean rooms screaming for help before someone worked out what she was on about claiming the SEM was 'on fire'. She was quite embarrased..:D

 

 

I love the stuff by the way - it's really nice to play with. Even just tipping it on the floor and watching it boil around is great! :D

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