absorptivity-emissivity

См. также в других словарях:

• Emissivity — The emissivity of a material (usually written ε or e) is the relative ability of its surface to emit energy by radiation. It is the ratio of energy radiated by a particular material to energy radiated by a black body at the same temperature. A… …   Wikipedia

• Absorptivity —   In a solar thermal system, the ratio of solar energy striking the absorber that is absorbed by the absorber to that of solar energy striking a black body (perfect absorber) at the same temperature. The absorptivity of a material is numerically… …   Energy terms

• Reflectivity — In photometry and heat transfer, reflectivity is the fraction of incident radiation reflected by a surface. In full generality it must be treated as a directional property that is a function of the reflected direction, the incident direction, and …   Wikipedia

• Passive solar building design — Elements of passive solar design, shown in a direct gain application …   Wikipedia

• Black body — As the temperature decreases, the peak of the blackbody radiation curve moves to lower intensities and longer wavelengths. The blackbody radiation graph is also compared with the classical model of Rayleigh and Jeans …   Wikipedia

• Kirchhoff's law of thermal radiation — See also Kirchhoff s laws for other laws named after Kirchhoff .In thermodynamics, Kirchhoff s law of thermal radiation, or Kirchhoff s law for short, is a general statement equating emission and absorption in heated objects, proposed by Gustav… …   Wikipedia

• Stefan–Boltzmann law — The Stefan–Boltzmann law, also known as Stefan s law, states that the total energy radiated per unit surface area of a black body in unit time (known variously as the black body irradiance, energy flux density, radiant flux, or the emissive… …   Wikipedia

• Mean radiant temperature — The Mean Radiant Temperature (MRT) is a concept arising from the fact that the net exchange of radiant energy between two objects is approximately proportional to their temperature difference multiplied by their ability to emit and absorb heat… …   Wikipedia

• Concentrated solar power — The PS10 Solar Power Plant concentrates sunlight from a field of heliostats onto a central solar power tower. Concentrated solar power (CSP) systems use mirrors or lenses to concentrate a large area of sunlight, or solar thermal energy, onto a… …   Wikipedia

• Selective surface — In solar thermal collectors, a selective surface is a means of increasing its operation temperature and/or efficiency. The selectivity is defined as the ratio of radiation absorption ( alpha ) to radiation emission ( epsilon ),. Selective… …   Wikipedia

• Thermal insulation — The term thermal insulation can refer to materials used to reduce the rate of heat transfer, or the methods and processes used to reduce heat transfer.Heat energy can be transferred by conduction, convection, radiation or when undergoing a phase… …   Wikipedia