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refractive index

(symbol: n) a measure of the extent to which a ray of light is bent (refracted) in passing from one transparent medium to another. The refractive index of a transparent medium is equal to the ratio of the speed of light in a vacuum to the speed of light in that medium. The value of n can vary with the wavelength of the light.

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Psychology term of the day

November 28th 2024

cocaine withdrawal

cocaine withdrawal

in DSM–IV–TR, a characteristic withdrawal syndrome that develops after cessation of (or reduction in) prolonged, heavy consumption of cocaine. The essential characteristic is depressed mood, sometimes severe, and there may also be fatigue, disturbed sleep, increased appetite, vivid and unpleasant dreams, or psychomotor retardation or agitation, or all of these features. Marked withdrawal symptoms (see crash) often follow an episode of intense, high-dose use. The equivalent term in DSM–5 is stimulant withdrawal. See also substance withdrawal.