Emission

• Emission of air pollutants, notably: • Flue gas, gas exiting to the atmosphere via a flue • Exhaust gas, flue gas generated by fuel combustion • Emission of greenhouse gases, which absorb and emit radiant energy within the thermal infrared range • Emission standards, limits on pollutants that can be released into the environment • Emissions trading, a market-based approach to pollution control ==Electromagnetic radiation==

• Emission spectrum, the spectrum of frequencies of electromagnetic radiation generated by molecular electrons making transitions to lower energy states • Thermal emission, electromagnetic radiation generated by the thermal motion of particles in matter • List of light sources, including both natural and artificial processes that emit light • Emission (radiocommunications), a 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 line, or "spectral line", a dark or bright line in an otherwise uniform and continuous spectrum • Emission nebula, a cloud of ionized gas emitting light of various colors • Emission theory (relativity), a competing theory for the special theory of relativity, explaining the results of the Michelson-Morley experiment • Emission theory (vision), the proposal that visual perception is accomplished by rays of light emitted by the eyes == Other uses ==

• Thermionic emission, the flow of charged particles from a charged metal or a charged metal oxide surface, archaically known as the Edison effect • Field emission, the releasing of electrons from a material due to effects of a strong electrostatic field • Ejaculation, the ejection of semen from the penis; also, specifically: • Nocturnal emission, ejaculation experienced during sleep • Noise, emission • Exhalation of air, especially in the context of musical instruments == See also ==