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  2. Emissivity - Wikipedia

    en.wikipedia.org/wiki/Emissivity

    A 'window' can be seen between 8 and 14 μm that enables direct transmission of the most intense thermal emissions from Earth's surface. The remaining portion of the upwelling energy, as well as downwelling radiation back to the surface, undergoes absorption and emission by the various atmospheric components as indicated.

  3. Thermal expansivities of the elements - Wikipedia

    en.wikipedia.org/wiki/Thermal_expansivities_of...

    As quoted from this source in an online version of: J.A. Dean (ed), Lange's Handbook of Chemistry (15th Edition), McGraw-Hill, 1999; Section 4; Table 4.1, Electronic Configuration and Properties of the Elements Touloukian, Y. S., Thermophysical Properties of Matter, Vol. 12, Thermal Expansion, Plenum, New York, 1975.

  4. Thermal emittance - Wikipedia

    en.wikipedia.org/wiki/Thermal_emittance

    Thermal emittance or thermal emissivity is the ratio of the radiant emittance of heat of a specific object or surface to that of a standard black body.Emissivity and emittivity are both dimensionless quantities given in the range of 0 to 1, representing the comparative/relative emittance with respect to a blackbody operating in similar conditions, but emissivity refers to a material property ...

  5. Emission spectrum - Wikipedia

    en.wikipedia.org/wiki/Emission_spectrum

    Emission coefficient is a coefficient in the power output per unit time of an electromagnetic source, a calculated value in physics. The emission coefficient of a gas varies with the wavelength of the light. It has unit m⋅s −3 ⋅sr −1. [18]

  6. Work function - Wikipedia

    en.wikipedia.org/wiki/Work_function

    The work function W for a given surface is defined by the difference [1] =, where −e is the charge of an electron, ϕ is the electrostatic potential in the vacuum nearby the surface, and E F is the Fermi level (electrochemical potential of electrons) inside the material.

  7. Low emissivity - Wikipedia

    en.wikipedia.org/wiki/Low_emissivity

    Low emissivity (low e or low thermal emissivity) refers to a surface condition that emits low levels of radiant thermal (heat) energy. All materials absorb, reflect, and emit radiant energy according to Planck's law but here, the primary concern is a special wavelength interval of radiant energy, namely thermal radiation of materials. In common ...

  8. Kirchhoff's law of thermal radiation - Wikipedia

    en.wikipedia.org/wiki/Kirchhoff's_law_of_thermal...

    Next, suppose we have a material that violates Kirchhoff's law when integrated, such that the total coefficient of absorption is not equal to the coefficient of emission at a certain , then if the material at temperature is placed into a Hohlraum at temperature , it would spontaneously emit more than it absorbs, or conversely, thus ...

  9. Radiative transfer - Wikipedia

    en.wikipedia.org/wiki/Radiative_transfer

    Solutions to the equation of radiative transfer form an enormous body of work. The differences however, are essentially due to the various forms for the emission and absorption coefficients. If scattering is ignored, then a general steady state solution in terms of the emission and absorption coefficients may be written: