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Q A sealed, area known to havo black damp, 18%0e2% Co nd 78% No If fresh, air has 21 ¼ O2, 0·08 coo, dnd 18.97% No,, the percendage of black daomp in the aro is., 18, 21, has, Solm) Air equivalout to O, E 85.11%, Nitrogen equivalont to 0,, = 18n78-974=, 67:63%, 21, Co, equivalout to 0,, 18'20.03%, 0:026%, = Excebs No + Excess co2, 78-67.69) + (2-0.026), 12.284%., Black Damp, 10.81+ 1. 974=, 2Calculate the percentage of block damp in, mine cohich gave the following air analysis, results. ? Og = 9.11%, No =19:04% , Co, = 0.25%, CH4= 1.58%., 4tmospheric are eutering the mine., 02= 20.93% ,No = 79004% , cos =O.0 3%, Sol Black damp 6-88% + öi2e%, Co=0.02%, 7.1A%

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Jaisri-, Page:, Date:, G-18, Air enters a, bord and pillar panel at 10 ppm, The air at the panel, 2, 20.78% 0,0, 80 Ppm, Qnd, refurn has, " Grraham's ratio" for the statw of fire in, the panel in % is, co, Co, and, 20.524. の2。The, 10 Ppm, 100000 0, 100000, 10ppm=, and, 80Ppm, 1000, 1600, GIR, $/1000-/100, 20.78- 20.52, 2069%