Word: hydrocarbons
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
Johnson said his agency believes its current controls to be "reasonable and essential," but added that he is not sure that current standards can be reached because the chief source of oxidant pollutions is not automobiles but solvents and points with hydrocarbon bases...
...objective of the impact analysis was to evaluate the maximum carbon monoxide levels which could arise as a consequence of both adverse meteorological conditions and peak roadway traffic. Although motor vehicles are also major contributors to community nitrogen oxides and reactive hydrocarbon emissions, these species participate in a series of complex photochemical reactions for which the current atmospheric diffusion modeling technology does not permit preparation of reliable estimates of projected concentration levels. Therefore, emphasis was placed principally on carbon monoxide concentration levels as this pollutant is relatively inert. In addition, carbon monoxide is the pollutant emitted in the largest quantities...
...Clean Air Act of 1970 mandated a 90 per cent cut in carbon monoxide and hydrocarbon emissions for 1975 cars. It also set a 1976 deadline for a similar cut in harder-to-control nitrogen oxide emissions. Both deadlines have since been extended to 1977-78 by the Energy Emergency...
After it is applied, aldrin gradually breaks down into dieldrin, a durable chlorinated hydrocarbon; the pesticide is long-lasting and requires only one application per year. That makes it more popular with farmers than shorter-lived, less potent pesticides that must be used more often and only at specific stages of the corn plants' growth. Dieldrin's impressive durability, says the EPA, is the very quality that makes it an increasingly serious threat...
...prize in chemistry went to Ernst Otto Fischer, 54, of Munich's Technical University and Geoffrey Wilkinson, 52, of London University's Imperial College of Science and Technology. Working independently, the two men explored organometallic compounds, a marriage of hydrocarbon compounds with metals like iron and chromium. Although such unusual combinations had long been known, it was Fischer and Wilkinson who first identified and explained the structure of a special class of organometallics, called sandwich compounds, that seemed to defy all known chemical rules. In these compounds, Fischer and Wilkinson found, the hydrocarbon molecules hold the metal atom...