Emission
Encyclopedia
Emission may refer to:
- Flue gasFlue gasFlue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produced at power plants...
, also:- Exhaust gasExhaust gasExhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline/petrol, diesel fuel, fuel oil or coal. According to the type of engine, it is discharged into the atmosphere through an exhaust pipe, flue gas stack or propelling nozzle.It often disperses...
, flue gas occurring as a result of the combustion of a fuel
- Exhaust gas
- Emission of air pollutantAir pollutionAir pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....
s - Emission of greenhouse gases, a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range
- Emission (electromagnetic radiation), the process by which the energy of a photon is released by another entity
- Emission (radiocommunications)Emission (radiocommunications)Emission is the radiation or radio signal produced or emitted by a radio transmitting station....
, the radio signal (usually modulated) emitted from a radio transmitter - Emission coefficient, a coefficient in the power output per unit time of an electromagnetic source
- Emission factorEmission factorAn emission intensity is the average emission rate of a given pollutant from a given source relative to the intensity of a specific activity; for example grams of carbon dioxide released per megajoule of energy produced, or the ratio of greenhouse gas emissions produced to GDP...
- Emission line, or "spectral line", a dark or bright line in an otherwise uniform and continuous spectrum
- Emission nebulaEmission nebulaAn emission nebula is a cloud of ionized gas emitting light of various colors. The most common source of ionization is high-energy photons emitted from a nearby hot star...
, a cloud of ionized gas emitting light of various colors - Emission spectroscopy, photoemission spectroscopy, flame emission spectroscopy and other types of spectroscopy
- Emission standardEmission standardEmission standards are requirements that set specific limits to the amount of pollutants that can be released into the environment. Many emissions standards focus on regulating pollutants released by automobiles and other powered vehicles but they can also regulate emissions from industry, power...
, requirements that set specific limits to the amount of pollutants that can be released into the environment - Emission theoryEmission theoryEmission theory was a competing theory for the special theory of relativity, explaining the results of the Michelson-Morley experiment...
, a competing theory for the special theory of relativity, explaining the results of the Michelson-Morley experiment - Emission theory (vision)Emission theory (vision)Emission theory or extramission theory is the proposal that visual perception is accomplished by rays of light emitted by the eyes. This theory has been replaced by intromission theory, which states that visual perception comes from something representative of the object entering the eyes...
, the proposal that visual perception is accomplished by rays of light emitted by the eyes - Emissions tradingEmissions tradingEmissions trading is a market-based approach used to control pollution by providing economic incentives for achieving reductions in the emissions of pollutants....
, a market-based approach used to control pollution by providing economic incentives for achieving reductions in the emissions of pollutants - EjaculationEjaculationEjaculation is the ejecting of semen from the male reproductory tract, and is usually accompanied by orgasm. It is usually the final stage and natural objective of male sexual stimulation, and an essential component of natural conception. In rare cases ejaculation occurs because of prostatic disease...
, the ejecting of semen from the penis; also, specifically:- Nocturnal emissionNocturnal emissionA nocturnal emission involves either ejaculation during sleep for a male, or lubrication of the vagina for a female. It is also called a wet dream, and is sometimes considered a type of spontaneous orgasm....
, ejaculation experienced during sleep
- Nocturnal emission
- Light emission
- Thermionic emissionThermionic emissionThermionic emission is the heat-induced flow of charge carriers from a surface or over a potential-energy barrier. This occurs because the thermal energy given to the carrier overcomes the binding potential, also known as work function of the metal. The charge carriers can be electrons or ions, and...
, the flow of charged particles called thermions from a charged metal or a charged metal oxide surface, archaically known as the Edison effect - Noise emission; see NoiseNoiseIn common use, the word noise means any unwanted sound. In both analog and digital electronics, noise is random unwanted perturbation to a wanted signal; it is called noise as a generalisation of the acoustic noise heard when listening to a weak radio transmission with significant electrical noise...
- ExhalationExhalationExhalation is the movement of air out of the bronchial tubes, through the airways, to the external environment during breathing....
, especially where the velocity of exhaled air can influence the harmonic generating properties of a vibrating body, such as the reed of a musical instrument like the saxophone