| exponential | Pertaining to exponents; involving variable exponents; as, an exponential expression; exponential calculus; an exponential function. Exponential curve, a curve whose nature is defined by means of an exponential equation. Exponential equation, an equation which contains an exponential quantity, or in which the unknown quantity enters as an exponent. <mathematics> Exponential quantity, a quantity whose exponent is unknown or variable, as a^x. Exponential series, a series derived from the development of exponential equations or quantities. Origin: Cf. F. Exponentiel. Source: Websters Dictionary (01 Mar 1998) |
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| exponential decay | <epidemiology> A decline in which the rate of decay is always proportional to the amount of material remaining; the constant of proportionality is the rate constant. (05 Dec 1998) |
| exponential distribution | The time until failure of a process at constant hazard. (05 Mar 2000) |
| exponential growth | <biology> A rate of growth of an organism, a part of an organism, or a population of organisms which, when graphed, produces an exponential or logarithmic curve. Such a rate occurs, for example: during the exponential growth phase, when a population of bacterial (or other) cells divide at a constant rate so that the total number of cells doubles with each division. (09 Oct 1997) |
| convex | Applied to a surface that is evenly curved outward, the segment of a sphere. Origin: L. Convexus, vaulted, arched, convex, fr. Con-veho, to bring together (05 Mar 2000) |
| convex lens | A converging lens. Synonym: plus lens. (05 Mar 2000) |
| convex mirror | A spherical reflecting surface that constitutes a segment of the exterior of a sphere. (05 Mar 2000) |
| high convex | The segment of a sphere of short radius. (05 Mar 2000) |
| double convex lens | A lens with both surfaces convex. Synonym: convexoconvex lens, double convex lens. (05 Mar 2000) |
| low convex | The segment of a sphere of long radius. (05 Mar 2000) |
| atrioventricular gradient | The diastolic pressure difference between the atrium and ventricle. (05 Mar 2000) |
| magnetic field gradient | In magnetic resonance imaging, a magnetic field that varies with location, superimposed on the uniform field of the magnet, to alter the resonant frequency of nuclei and allow recovery of their spatial position. Synonym: field gradient. (05 Mar 2000) |
| ventricular gradient | The algebraic sum of (i.e., the net electrical difference between) the area enclosed within the QRS complex and that within the T wave in the electrocardiogram. (05 Mar 2000) |
| voltage gradient | <physiology> Literally, the electric field in a region, defined as the potential difference between two points divided by the distance between them. Used more loosely, the potential difference across a plasma membrane. (18 Nov 1997) |
| centrifugation, density gradient | Separation of particles according to density by employing a gradient of varying densities. at equilibrium each particle settles in the gradient at a point equal to its density. (12 Dec 1998) |