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.
Pyroclastic flows that contain a much higher proportion of gas to rock are known as fully dilute pyroclastic density currents or pyroclastic surges. The lower density sometimes allows them to flow over higher topographic features or water such as ridges, hills, and sea. They may also contain steam, water and rock at less than 250 Â°C (482 Â°F); these are called cold compared with other flows, although the temperature is still lethally high.