AEROSOLS |
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Aerosol spray is the name given to a type of canister containing liquid under pressure from pressurized vapor in equilibrium with another liquid, which often also dissolves the payload (see propellant below). When the can's valve is opened, the liquid is forced out of a small hole and emerges as an aerosol, or mist. As gas expands to drive out the payload, some propellant evaporates inside the can to maintain an even pressure. Outside the can, the droplets of propellant evaporate rapidly, leaving the payload suspended as very fine particles or droplets. Typical liquids dispensed in this way are insecticides, deodorants and paints. An atomiser is a similar device that is pressurised by a hand-operated pump rather than by stored gas.
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COMBUSTION |
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Combustion or burning is a chemical process, an exothermic reaction between a substance (the fuel) and a gas (the oxidizer), usually O2, to release heat. In a complete combustion reaction, a compound reacts with an oxidizing element, and the products are compounds of each element in the fuel with the oxidizing element. For example:
CH4 + 2 O2 → CO2 + 2 2O + heat
CH2S + 6 F2 → CF4 + 2 HF + SF6 + heat
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HAZMET - HAZARDOUS MATERIALS |
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A hazardous material (HAZMAT) is any solid, liquid, or gas that can cause harm to humans, other living organisms, or the environment due to being radioactive, flammable, explosive, toxic, corrosive, a biohazard, an oxidizer, an asphyxiant, or capable of causing severe allergic reactions. The term hazardous material is used in this context almost exclusively in the United States. The equivalent term in the rest of the English-speaking world is Dangerous Goods.
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LIQUIFIED PETROLEUM GAS - LPG - LP GAS |
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Liquified petroleum gas (also called liquefied petroleum gas, liquid petroleum gas, LPG, LP Gas, or autogas) is a mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles, and increasingly replacing chlorofluorocarbons as an aerosol propellant and a refrigerant to reduce damage to the ozone layer. Varieties of LPG bought and sold include mixes that are primarily propane, mixes that are primarily butane, and mixes including both propane and butane, depending on the seasonin winter more propane, in summer more butane. Propylene and butylenes are usually also present in small concentration. A powerful odorant, ethanethiol, is added so that leaks can be detected easily. LPG is manufactured during the refining of crude oil, or extracted from oil or gas streams as they emerge from the ground.
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