1 The pressure on a diver increases by 100 kPa (1.00 atm) for every - - PDF document

▶

Feb 09, 2024 297 likes •482 views

1 The pressure on a diver increases by 100 kPa (1.00 atm) for every 10 m the diver descends. For dives deeper than 66 m the gas mixture should contain less than 21% oxygen to avoid the risk of acute oxygen toxicity. The general rule is to try to

SLIDE 1

1

SLIDE 2

2

The pressure on a diver increases by 100 kPa (1.00 atm) for every 10 m the diver descends. For dives deeper than 66 m the gas mixture should contain less than 21%

xygen to avoid the risk of acute oxygen toxicity. The general rule is to try to

achieve a gas mixture giving an Fio2 of about 140 kPa. At 130 m depth in the northern sector of the North Sea oil field, the ambient pressure is 1400 kPa, so the breathing mixture used contains 10% oxygen. On the deepest working dives, at depths greater than 600 m, ambient pressure is greater than 6100 kPa and the divers breathe gas mixtures containing about 2% oxygen to avoid acute oxygen toxicity. A lung full of gas containing 2% oxygen at 600 m contains about six times as many molecules of oxygen as a lung full of air at sea level. On deep dives the composition of the gas breathed is changed several times during descent and ascent. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1114047/ 600 m => 6100 kP => 60 atm! 60 x (2%/100%) => P(O2) = 1.2 atm

https://en.wikipedia.org/wiki/Partial_pressure#In_medicine

SLIDE 3

3

http://slideplayer.com/slide/4772848/

1 2 1 2 1 2 i f 1 2 i f

P V = nR T P P P nR nR as s uming V is cons tant => = = > = = T V T V T P P P P S

= T T T T

i f f i

P T 27.2 ps i x 282 K P = = = 25.9 ps i T 296 K Ti = 23 oC + 273.15 = 296 K Tf = 9 oC + 273.15 = 282 K Rearranging this expression, the final pressure at halftime would be

25.9 psi (absolute) - 14.7 = 11.2 psi-g Below the 12.5 - 13.5 “psi” required by the NFL, but not 2 psi below the minimum allowed pressure

SLIDE 4

4

2NaN3(s)  2Na(s) + 3N2(g)

https://www.youtube.com/watch?v=IzC_QqKhTQg

SLIDE 5

5

SLIDE 6

6

http://www.ncert.nic.in/html/learning_basket/energy10class/combustion%20engine1.htm

SLIDE 7

7

chemical energy (fuel) you add  energy you release (light, heat, motion)

fuel + O2  CO2 + H2O food + O2  CO2 + H2O

chemical energy (food) you add  energy you release (heat, to maintain body temperature; motion, to do work)

SLIDE 8

8

SLIDE 9

9

SLIDE 10

10

We use stored energy from food at a rate ranging from about 1 Cal/min (basal metabolic rate) to about 15 Cal/min.

SLIDE 11

11

Assumptions: No exercise beyond the normal activity to burn 2000 Calories per day. No food.  Get energy from glycogen until gone, then burn fat after that.

http://www.uic.edu/classes/phar/phar332/Clinical_Cases/carbo%20metab%20cases/ glycogen%20metab/Glycogen%20biochemistry.htm

SLIDE 12

12

Assuming an energy need of 2000 Cal/day and no food (!) during this time: 2000 Cal/day  (1 g/9 Cal)  (1 lb/453.6 g) 0.4899 lb/day So, max weight loss in 20 days is 1 lb (1st day, glycogen) + 19 day(0.5 lb/day) = 10.5 lb ! Assuming an energy need of 2000 Cal/day and no food (!) during this time: 2000 Cal/day  (1 g/9 Cal)  (1 lb/453.6 g) 0.4899 lb/day So, max weight loss in 20 days is 1 lb (1st day, glycogen) + 19 day(0.5 lb/day) = 1 lb + 19(0.5) = 10.5 lbs ! But what if protein is “burned” for energy instead

f fat

2000 Cal/day  (1 g/4 Cal)  (1 lb/453.6 g) 1.1 lb/day So, max weight loss in 20 days is 1 lb (1st day, glycogen) + 19 day(1.1 lb/day) = 1 lb + 19(1.1) = 22 lbs !?

SLIDE 13

13

Figure 5.19 The internal energy, U, of a system can be changed by heat flow and work. If heat flows into the system, qin (q > 0), or work is done on the system, won (w > 0), its internal energy increases, ΔU > 0. If heat flows

ut of the system, qout (q < 0), or work is done by the system, wby, (w < 0),

its internal energy decreases, ΔU < 0.

SLIDE 14

14

H2 O2 2:1 H2+O2 Which balloon contains the most molecules?

A. the H2 balloon
B. the O2 balloon
C. the H2/O2 balloon
D. they all contain the same number of

molecules

SLIDE 15

15

H2 O2 2:1 H2+O2 Which balloon is the heaviest?

A. the H2 balloon
B. the O2 balloon
C. the H2/O2 balloon
D. all three balloons are equally heavy

H2 O2 2:1 H2+O2 Which balloon is the densest?

A. the H2 balloon
B. the O2 balloon
C. the H2/O2 balloon
D. all three balloons are equally dense

SLIDE 16

16

H2 O2 2:1 H2+O2 Which balloon released the most energy?

A. the H2 balloon
B. the O2 balloon
C. the H2/O2 balloon
D. all three balloons are equally dense