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.
Viscosity in lava is chiefly influenced by temperature, and the presence of gases. The higher the temperature of a given lava flow, the lower the viscosity. A particular lava may initially flow rapidly, but as temperature decreases, viscosity will increase, and alter the type of flow. The presence of dissolved gases called volatiles also plays a key role in lava flow, and type of eruption.