Function
As a person breathes, the body consumes oxygen and produces carbon dioxide. The oxygen metabolised is generally about 4% to 5% of the inspired volume at normal atmospheric pressure, and exhaled air still contains roughly 16% oxygen. The situation is even more wasteful of oxygen when the oxygen fraction of the breathing gas is higher. By adding sufficient oxygen to compensate for the metabolic usage, and rebreathing the gas, most of the volume is conserved. However, if this is done without removing the carbon dioxide, it will rapidly build up in the recycled gas, resulting almost immediately in mild respiratory distress, and rapidly developing into further stages of hypercapnia, or carbon dioxide toxicity. To avoid this problem, carbon dioxide is chemically removed in a component known as a carbon dioxide scrubber.
Read more about this topic: Rebreather
Famous quotes containing the word function:
“The mother’s and father’s attitudes toward the child correspond to the child’s own needs.... Mother has the function of making him secure in life, father has the function of teaching him, guiding him to cope with those problems with which the particular society the child has been born into confronts him.”
—Erich Fromm (1900–1980)
“Uses are always much broader than functions, and usually far less contentious. The word function carries overtones of purpose and propriety, of concern with why something was developed rather than with how it has actually been found useful. The function of automobiles is to transport people and objects, but they are used for a variety of other purposes—as homes, offices, bedrooms, henhouses, jetties, breakwaters, even offensive weapons.”
—Frank Smith (b. 1928)
“The information links are like nerves that pervade and help to animate the human organism. The sensors and monitors are analogous to the human senses that put us in touch with the world. Data bases correspond to memory; the information processors perform the function of human reasoning and comprehension. Once the postmodern infrastructure is reasonably integrated, it will greatly exceed human intelligence in reach, acuity, capacity, and precision.”
—Albert Borgman, U.S. educator, author. Crossing the Postmodern Divide, ch. 4, University of Chicago Press (1992)