Word: oxygenating
(lookup in dictionary)
(lookup stats)
Dates: during 1980-1989
Sort By: most recent first
(reverse)
Ozone, a highly unstable union of three oxygen atoms, provides the vital function of absorbing most of the sun's ultraviolet radiation. It is continuously being formed in the stratosphere, when regular oxygen molecules interact with ultraviolet radiation...
...rising 3,000 ft. higher, notably the snow-covered volcanoes Popocatépetl and Iztaccíhuatl. ("The two monsters," D.H. Lawrence wrote of them, "watching gigantically and terribly over their lofty, bloody cradle of men ... murmuring like two watchful lions.") The thin air not only contains 30% less oxygen than at sea level but makes auto engines produce nearly twice as much carbon monoxide and hydrocarbon pollution. Then, when the city's befouled air rises, the mountains trap it in the virtually permanent smog that now blocks the snowy crests from sight. The 14 million new saplings that...
...even greater source of concern is the destruction of the bay's submerged aquatic grasses. This vegetation produces the oxygen essential for the survival of marine life, stabilizes the shoreline against erosion and provides food for species ranging from ducks to fish to crab larvae. In 1971 this subaquatic plant life could be found in 30% of the Chesapeake and its tributaries. Now, says the EPA study, it can be found in only 4.5% of that area...
...sediment, which blocks the light that plants need in order to carry on photosynthesis. Another problem is the bay's excess of nitrogen and phosphorus. These nutrients "fertilize" the bay and promote the proliferation of algae. When algae decompose, they rob the water of its life-giving oxygen, killing the grasses and the creatures that depend on them. There are areas of the bay-submarine deserts-where nothing at all can live...
Discovery's engine No. 3 had already helped power three shuttle missions, and its age was showing. About 6 sec. before blastoff, a heated mixture of liquid hydrogen and liquid oxygen was supposed to be pumped forcefully through the engine's main fuel line into a central combustion chamber, where it would ignite. But the 10 ¼ in. long, 74-lb. fuel valve faltered a fraction of a second in opening, prompting the central computer system to abort the entire mission. Of the three main engines, only No. 2 had been fully ignited. During its 1.7 sec. ignition...