Daily Archives March 8, 2016
Assessment of humans exposed directly in a chamber to MTBE was hoped to answer whether there was a direct causal relation between MTBE exposure and acute health symptoms, particularly in view of the inconclusive evidence gathered from the field epidemiology studies. In an EPA investigation, 37 healthy nonsmoking individuals were exposed for 1 h to both clean air and 1.4 ppm (5mg/m3) ‘‘pure’’ MTBE in air at 75° F and 40% humidity...Read More
Coal gas and petroleum energy share the property of having hydrocarbons as their principal constituents; coal gas is rich in the hydrocarbon methane, whereas petroleum consists of a complex mixture of liquid hydrocarbons. The use of petroleum products long antedates the use of coal gas. In Mesopotamia, concentrations of petroleum deposits provided commerce and production. Babylonians called inflammable oil ‘‘naphtha.’’ For thousands of years, mixtures containing bitumen were used in roads, ship caulking, floor waterproofing, hard mortar, and medicines. Naphtha was militarily important as a weapon, although Romans derived their bitumen from wood pitch. Aztecs made chewing gum made with bitumen, and during the 16th century oil from seepages in
Havana was used to caulk ships...Read More
Acute health symptoms attributed to methyl tert – butyl ether (MTBE) were reported in various parts of the United States soon after the addition of oxygenated compounds to gasoline during the winter of 1992-1993. Such complaints were not anticipated but have subsequently focused attention on possible health risks due to oxygenated gasoline. The health complaints were accompanied by complaints about reduced fuel economy and engine performance and by controversial cancer findings in long-term animal studies.
Following the introduction of MTBE-oxygenated gasoline in Fairbanks, Alaska, in November 1992, about 200 residents reported headaches, dizziness, irritated eyes, burning of the nose and throat, coughing, disorientation, nausea, and other a...Read More
University of Illinois at Chicago Chicago, Illinois, United States
1. Introduction to Gasoline Additives
2. Human Health Effects of Methyl Tertiary-Butyl Ether (MTBE)
3. Human Health Effects of Other Ether Compounds
4. Human Health Effects of Ethanol
5. Conclusions and Recommendations
Since 1979, oxygenates as gasoline additives have been used in limited areas of the United States as octane enhancers to replace lead at levels around 2 to 8% by volume. During the 1980s, oxygenates came into wider use as some states implemented oxygenated gasoline programs for the control of carbon monoxide air pollution in cold winter...Read More
Steam-powered engines were crucial in the development of transportation. Roads often were little more than deeply gouged tracks, slowing people, carriages, and carts in an energy-hindering quagmire. The growing demands for bulk fuel beyond what was locally available, with the high cost of transport added to the expense of energy resources, expedited innovation.
During the 1700s, British canals were improved, and tow paths allowed heavily burdened vessels to be pulled by teams of horses. Combining water and steam power, a paddlewheel steamboat ascended a river in 1783 near Lyons, France...Read More
In the 6th century все, Greek philosophers described the universal elements as consisting of air, earth, fire, and water. It was established that water displaced air and that steam condensed back to liquid and could rotate wheels. During the 17th century, the physical nature of the atmosphere was explored in qualitative rather than quantitative terms; water and other liquids entering vacuous space was attributed to nature abhorring a vacuum. The persistent problem of mine drainage inspired understanding of atmospheric pressure, leading to the earliest steam engines.
When engineers failed to drain excess water from Italian mines during the 1600s, Galileo was enlisted...Read More
Coal had been widely harvested and exploited as an energy source for thousands of years. In Asia, coal provided little illumination but plenty of heat. Romans in Britain found that stones from black outcrops were flammable, and Roman soldiers and blacksmiths used this coal to provide heat. During the 13th and 14th centuries, a multitude of industries became dependent on a regular supply of coal. In salt production, coal was used to heat enormous pans of sea water. If woodlands had not been devoted nearly exclusively to the production of timber, their yield could not have met the fuel value generated by that produced by coal mines. It took an annual yield from 2 acres of well-managed woodlands to equal the heat energy of a ton of coal...Read More
Windmills were developed in Persia by the 9th century все. This technological innovation was spurred by the need to mill corn in areas lacking consistent water supplies. Early windmills used an upright shaft, rather than a horizontal one, to hold the blades. This system was housed in a vertical adobe tunnel with flues to catch the wind (similar to a revolving door). The concept of harnessing wind energy via windmills reached Britain and Europe by 1137, where it underwent significant changes, with horizontal (rather than vertical) shafts and horizontal rotation. A form of solar energy, climate-dependent wind power has been unreliable and difficult to accumulate and store.
Roman aqueducts provided a system of fastflowing water to watermills...Read More