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21Effective porosity — The term effective porosity lacks a single or straightforward definition. Even some of the terms used in its mathematical description (“Vcl” and “Vsh”) have multiple definitions. However, it is most commonly considered to represent the porosity… …
22Effective mass — In solid state physics, a particle s effective mass is the mass it seems to carry in the semiclassical model of transport in a crystal. It can be shown that, under most conditions, electrons and holes in a crystal respond to electric and magnetic …
23Effective demand — In economics, effective demand in a market is the demand for a product or service which occurs when purchasers are constrained in a different market. It contrasts with notional demand, which is the demand that occurs when purchasers are not… …
24Effective temperature — Star The effective temperature of a star is the temperature of a black body with the same luminosity per surface area (mathcal{F} {Bol}) as the star and is defined according to the Stefan–Boltzmann law mathcal{F} {Bol}=sigma T {eff}^4. Notice… …
25Effective population size — In population genetics, the concept of effective population size N e was introduced by the American geneticist Sewall Wright, who wrote two landmark papers on it (Wright 1931, 1938). He defined it as the number of breeding individuals in an… …
26Effective interest rate — The effective interest rate, effective annual interest rate, Annual Equivalent Rate (AER) or simply effective rate is the interest rate on a loan or financial product restated from the nominal interest rate as an interest rate with annual… …
27Effective action — In quantum field theory, the effective action is a modified expression for the action, which takes into account quantum mechanical corrections, in the following sense: In classical mechanics, the equations of motion can be derived from the action …
28Effective field theory — In physics, an effective field theory is an approximate theory (usually a quantum field theory) that includes appropriate degrees of freedom to describe physical phenomena occurring at a chosen length scale, while ignoring substructure and… …
29Effective frequency — In advertising, the effective frequency is the number of times a person must be exposed to an advertising message before a response is made and before exposure is considered wasteful.The subject on effective frequency is quite controversial. Many …
30Effective evolutionary time — The hypothesis of effective evolutionary timeK. Rohde: Latitudinal gradients in species diversity: the search for the primary cause, Oikos, 65, 514 527,1992.] attempts to explain gradients, in particular latitudinal gradients, in species… …
