| acceleration | The act of accelerating, or the state of being accelerated; increase of motion or action; as, a falling body moves toward the earth with an acceleration of velocity; opposed to retardation. "A period of social improvement, or of intellectual advancement, contains within itself a principle of acceleration." (I. <astronomy> Taylor) Acceleration of the moon, the increase of the moon's mean motion in its orbit, in consequence of which its period of revolution is now shorter than in ancient times. Acceleration and retardation of the tides. See Priming of the tides, under Priming. Diurnal acceleration of the fixed stars, the amount by which their apparent diurnal motion exceeds that of the sun, in consequence of which they daily come to the meridian of any place about three minutes fifty-six seconds of solar time earlier than on the day preceding. Acceleration of the planets, the increasing velocity of their motion, in proceeding from the apogee to the perigee of their orbits. Origin: L. Acceleratio: cf. F. Acceleration. Source: Websters Dictionary (01 Mar 1998) |
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| acceleration phase | <cell biology, cell culture> A period of increasing growth before the log phase in a culture of microbes. After the culture is started on a medium, at first there is no growth (the lag phase) and then the microbes start to gradually grow (acceleration phase) until they reach a constant maximum rate of growth (log phase). (15 Jan 1998) |
| angular acceleration | The rate of change of angular velocity; e.g., when a centrifuge rotor is speeding up, or when there is a simultaneous change in velocity and direction, as in an aircraft in a tight spin. (05 Mar 2000) |
| radial acceleration | The centripetal acceleration of a particle or vehicle moving along a curved path at a constant velocity; e.g., turning a curve in an automobile, pulling out of a dive, or performing a loop manoeuvre in an aircraft. In aviation, acceleration varies directly with the square of the air speed and inversely with the radius of the turn (a = V2/r, where V is air speed and r is radius of turn). (05 Mar 2000) |
| linear acceleration | The rate of change of velocity without a change in direction; e.g., when the speed of an aircraft increases while flying a straight pathway. (05 Mar 2000) |
| physiological | Of or pertaining to physiology; relating to the science of the functions of living organism; as, physiological botany or chemistry. Source: Websters Dictionary (01 Mar 1998) |
| physiological adaptation | A peculiarity of the basic physical and chemical activities that occur in cells and tissues of a species, which results in it being better fitted to its environment (for example, ability to absorb nutrients under low oxygen tensions). (09 Oct 1997) |
| physiological anatomy | Anatomy studied in its relation to function. Synonym: morphophysiology, physiological anatomy. (05 Mar 2000) |
| physiological chemistry | The scientific study of the chemistry of living cells, tissues, organs and organisms. (09 Oct 1997) |
| physiological drives | Those drives such as hunger and thirst which stem from the biological needs of an organism. Synonym: primary drives. (05 Mar 2000) |
| physiological homeostasis | bernard-Cannon homeostasis |
| physiological intracranial calcification | <radiology> Pineal gland, habenular commisure, choroid plexus, dura, pacchionian bodies, basal ganglia and dentate nucleus (12 Dec 1998) |
| physiological processes | The functions of living organisms and their parts, and the physical and chemical factors and processes involved. (12 Dec 1998) |
| physiological sphincter | A section of a tubular structure that acts as if it has a band of circular muscle to constrict it, although no such specialised structure can be found on morphological examination. Synonym: functional sphincter, radiological sphincter. (05 Mar 2000) |
| adverse drug reaction reporting systems | Systems developed for collecting reports from government agencies, manufacturers, hospitals, physicians, and other sources on adverse drug reactions. (12 Dec 1998) |