Effect of slow compartments size in relation to NDL and DECO

[scubadada]

@boulderjohn

 

[tbone1004]

Not opposed, rather in addition to.

why? and why have I never been bent while diving identical dive profiles at 275lbs to one of my dive partners who is 110lbs?

so if inert gas is going in and going out at different volumetric rates as a function of half life, which you stated, why does the mass of the inert gas matter?

 

[Dan_P]

@boulderjohn can I trouble you for the instructor number of the "UTD instructor" you mentioned before, please?
PM is fine if you deem it appropriate.

 

[Neilwood]

It's simply amazing that all the scientists conducting all those experiments over all those decades not only never thought of this, they never noticed those obvious results in their experiments. Those that are still alive will no doubt feel like total dunces once they read your analysis. Why didn't we think of that? How did we not notice those effects in our test subjects? I cannot wait until you publish your analysis and we get the ensuing cataclysmic change in dive theory. Once you have proven that all previous dive theory is wrong, you will justifiably be honored as the new father of modern dive theory.

John, while I agree wholeheartedly with your post, I would ask that you reimburse me the cost for a new computer monitor as mine is struggling to work now after a coffee/monitor interface moment!

 

[electric_diver]

I think people are forgetting the role fat has in maintaining core temperature and thus efficient circulation and off-gassing.
I've seen plenty of skinny divers shivering and suffering from near hypothermia after deco dives even in relatively warm water. Just how effecient do you think their off gassing was? They were the coldest on theirdeco stops which is when you want good circulation to off gas.

The obese divers I've seen seem to be able to remain warm longer.

 

[KenGordon]

1L of fat = 0.9 kg fat
1L of fat will hold 0,063g N2 when saturated at 30 meters or 100ft.

Peter: 25x0.063 = 1.6kg N2
Paul: 31.5x0.063 = 2 kg N2

I think you have made a 1000 fold error here, from g to kg. I suspect Paul has completely dissolved all the N2 in his Ali80 by this point.

 

[dmaziuk]

Now I'm wondering how much fat tissue one has to have to be able to dissolve 2 kilos of gaseous nitrogen... would that be a humpback whale-size-fat diver or a supertanker-obese one.

 

[narke]

I think you have made a 1000 fold error here, from g to kg. I suspect Paul has completely dissolved all the N2 in his Ali80 by this point.

I checked you are right I mixed up the decimal's mark, that caused the shift. I thank you warmly, I run the math again following the same logic hopefully on Friday I will find the time and see what values turn out and share back.

 

[victorzamora]

I think you have made a 1000 fold error here, from g to kg. I suspect Paul has completely dissolved all the N2 in his Ali80 by this point.

That's a great catch, Ken. I completely glossed over the math because I didn't have time to look at it, but 2kg of N2 dissolved into Paul? Considering an AL80 full of air has (.075*77.4*.79) 4.58lbs or 2.07kg of Nitrogen....that's a LOT of N2 to dissolve. Divers would look like CCR divers while on-gassing and look like free-flowing tanks while off-gassing.

 

[victorzamora]

I checked you are right I mixed up the decimal's mark, that caused the shift. I thank you warmly, I run the math again following the same logic hopefully on Friday I will find the time and see what values turn out and share back.

If that was the only mistake, then just take the "k" out of your answers. 1.6g vs 2.0g of Nitrogen in Peter vs Paul.