Engineering causes

Adiabatic expansion of the air in the engine causes a maximum temperature drop of the exhaust. Adiabatic compression causes a maximum temperature rise of the compressed air. These effects combine to cause the greatest work loss of any compressed-air system, when pressurized air must be cooled back to atmospheric temperature. The energy analysis parallels the one just made for the polytropic system. This shows that net areas on both PV and TS graphs measure the work lost. 

FoUowing are the chemical reactions for the production of ozone at ground level. Ozone can be formed when a mixture of and NO is exposed to sunhght. Given that this reaction is very slow at normal temperatures, it is not a problem until hot gases in the cylinders of automobiles internal combustion engines cause the foUowing more rapid reactions. 

It does not burn smoothly in automobile engines, causing a noisy condition known as knocking. Isooctane, a less flexible, branched isomer of octane with the formal name 2,2,4-trimethylpentane, burns more smoothly. 

The burning of fossil fuels in internal combustion engines causes nitrogen and oxygen to react, forming nitrogen oxides such as NO and NO2. 

Combustion of fuels in internal combustion engines, causes emissions of aldehydes. Aldehydes are either formed in the cold zones of the combustion chamber, in the exhaust pipe or over the oxidation catalyst by partial oxidation of unbumed alcohol. Acetaldehyde is the principal aldehyde formed in ethanol combustion and it is one of the compounds, which the US Enviromnental Rotection Agency proposes as a future regulated pollutant. Acetic acid, which has a characteristic smell and can be experienced as an irritant far below directly hazardous concentrations, can also appear in the exhaust from ethanol-fuelled vehicles. Consequently, it is important to minimize these emissions. 

Parts of an impacting aircraft, especially the engines, cause local effects such as perforation and missUe generation in the rear side of an impacted wall. 

The primary cause of unbumed hydrocarbons in the engine cylinder is wall quench, wherein the relatively cool wall in the combustion chamber of the internal combustion engine causes the flame to be extinguished within several thousandths of a centimeter from the wall. Part of the remaining hydrocarbons may be retained as residual gas in the cylinder, and part may be oxidized in the exhaust system. The remainder is emitted to the atmosphere as pollutant hydrocarbons. Engine misfire due to improper adjustment and deceleration greatly increases the emission of hydrocarbons. Turbine engines are not subject to the wall quench phenomenon because their surfaces are always hot. 

Severe inlet corrosion was experienced (Pigs. A-52 to A-54) to such a degree that in places the perforated sheet became detached from the base frame (Pig. A-55). This released considerable amounts of debris into the engine, causing even frirther damage. 

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