A blood alcohol concentration (BAC) or blood alcohol level (BAL) reflects the amount of alcohol in the body. Food, type and quantity of beverage, weight, sex, and rate of elimination determine the BAC after the consumption of alcohol.
The process of oxygen transfer in the gills of a fish is a good example of the benefits of countercurrent exchange. As oxygen poor blood meets an opposed flow of oxygen rich water, the oxygen begins to diffuse out of the water and into the blood stream.
At constant pressure, q = ÎHtrs , which is defined as the enthalpy change accompanying the transition. If the phase transition is exothermic (ÎHtrs < 0 , e.g. freezing or condensing) then the entropy change is negative, reflecting the greater ordering in the phase that is formed during the transition.