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A temperature coefficient describes the relative change of a physical property that is associated with a given change in temperature.For a property R that changes when the temperature changes by dT, the temperature coefficient α is defined by the following equation:
Quantity (common name/s) (Common) symbol/s Defining equation SI unit Dimension Temperature gradient: No standard symbol K⋅m −1: ΘL −1: Thermal conduction rate, thermal current, thermal/heat flux, thermal power transfer
in which α is a positive coefficient called the thermal diffusivity of the medium. In addition to other physical phenomena, this equation describes the flow of heat in a homogeneous and isotropic medium, with u ( x , y , z , t ) being the temperature at the point ( x , y , z ) and time t .
A positive-temperature-coefficient heating element (PTC heating element), or self-regulating heater, is an electrical resistance heater whose resistance increases significantly with temperature. The name self-regulating heater comes from the tendency of such heating elements to maintain a constant temperature when supplied by a given voltage.
In thermochemistry, a thermochemical equation is a balanced chemical equation that represents the energy changes from a system to its surroundings.One such equation involves the enthalpy change, which is denoted with In variable form, a thermochemical equation would appear similar to the following:
The coefficients of the differential quantities are intensive quantities (temperature, pressure, chemical potential). Each pair in the equation are known as a conjugate pair with respect to the internal energy. The intensive variables may be viewed as a generalized "force".
In this region the device has a small negative temperature coefficient. At the Curie point temperature, the dielectric constant drops sufficiently to allow the formation of potential barriers at the grain boundaries, and the resistance increases sharply with temperature. At even higher temperatures, the material reverts to NTC behaviour.
A plot illustrating the dependence on temperature of the rates of chemical reactions and various biological processes, for several different Q 10 temperature coefficients. The rate ratio at a temperature increase of 10 degrees (marked by points) is equal to the Q 10 coefficient. The Q 10 temperature coefficient is a measure of temperature ...