Emission

Look up emission or emissions in Wiktionary, the free dictionary.

Emission may refer to:

Emission of chemical products:

• 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 radiation in the thermal infrared range
• Emission intensity, a measure of the emission rate of a given pollutant from a given source
• Emission standards, requirements that set specific limits on the amount of certain pollutants that can be released into the environment
• Emissions trading, a market-based approach used to pollution control

Emission of electromagnetic radiation:

• Emission (electromagnetic radiation), a process by which energy is released in the form of photons
  • List of light sources
• 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 spectrum, photoemission spectroscopy, flame emission spectroscopy and other types of spectroscopy
• Emission theory, 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 called thermions from a charged metal or a charged metal oxide surface, archaically known as the Edison effect
• Ejaculation, the ejecting 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

• Emissions control (disambiguation)