Many households in developing countries prepare food over indoor cook stoves with no ducting system to exhaust the combustion pr
oducts outside. A woman in a household lights a fire in her cookstove at 4 pm. The fire emits benzo(a)pyrene, a carcinogenic compound, at a rate of 0.01 ng/min. The house has a size of 40 m3 and a ventilation rate of 1 m3/h. The ambient indoor air concentration of benzo(a)pyrene was 0.2 ng/m3 when she started the fire, but no significant concentration of benzo(a)pyrene is found in the outdoor air. What is the indoor benzo(a)pyrene concentration in the household at 6 pm?
Let's solve this problem for part the total time in the kitchen is
t = 2h (60 min / 1h) = 120 min
The concentration (C) quantity of benzol pyrene is the initial quantity plus the quantity generated per area minus the quantity eliminated by the air flow. The amount removed can be calculated assuming that an amount of extra air that must be filled with the pollutant
amount generated
C = co + time_generation rate / (area_house + area_flow)
Even though the content of many alcohol blends doesn't affect engine driveability, using gasoline with alcohol in warm weather may cause: decrease in fuel economy.
Constellations describes a group of stars that appear to form a pattern or a picture. Example of common patterns are : Leo the Lion or Orion the Great Hunter. It is easy to recognize constellations and most people will tend to orient with these patterns. There are 88 patterns currently known.
