| unit of force | CGS system: dyne, FPS system: poundal, MKS system: newton,SI: newton. (05 Mar 2000) |
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| force | <physics> Rate of change of momentum with time. Forces are said to cause accelerations via f = ma (Newton's law). There are four primary forces known presently: the gravitational, electromagnetic, weak nuclear, and strong nuclear forces. The gravitational and electromagnetic forces are long-range (dropping as 1/distance^2), while the nuclear forces are short range (effective only within nuclei, distances on the order of 10^-15 metres). The electromagnetic force is much stronger than the gravitational force, but is generally cancelled over large distances because of the balance of positive and negative charges. See: momentum. (04 Apr 1998) |
| force of infection | <epidemiology> The per capita rate at which susceptibles are infected. (05 Dec 1998) |
| force of mastication | The motive force created by the dynamic action of the muscles during the physiologic act of mastication. Synonym: biting strength, masticatory force. (05 Mar 2000) |
| force platform | A device used to measure the strength, symmetry, and latency of compensatory postural movements when visual, vestibular, and somatosensory stimuli are varied. (05 Mar 2000) |
| force pump | <machinery> A pump having a solid piston, or plunger, for drawing and forcing a liquid, as water, through the valves; in distinction from a pump having a bucket, or valved piston. A pump adapted for delivering water at a considerable height above the pump, or under a considerable pressure; in distinction from one which lifts the water only to the top of the pump or delivers it through a spout. Source: Websters Dictionary (01 Mar 1998) |
| force-velocity curve | The relationship between isotonic velocity of shortening and afterload for a contracting muscle. (05 Mar 2000) |
| lorentz force | <physics> Total electromagnetic force on a charged particle moving in electric & magnetic fields. F = q(E + (v/c)xB). See: force, cross product, charge, velocity, and relevant variable symbols. (09 Oct 1997) |
| Abbe test plate | <equipment> A long, wedge-shaped coverslip about 0.20 mm thick at one end and 0.10 to 0.12 mm at the other end coated chemically with a silver film on which are ruled horizontal lines. at each variation in thickness of 0.01 mm there are vertical lines. By means of oblique illumination and by focusing on different portions of the plate, it is possible to determine the optimum coverslip thickness for any objective and also, for microscopes with drawtubes, the tube length for best objective performance. The approximate freedom from spherical and chromatic aberrations can also be estimated. Small isolated bits of silver near the edges of the lines form good objects for the star test (05 Aug 1998) |
| alar plate of neural tube | The dorsal division of the lateral walls of the neural tube in the embryo; it gives rise to neurons relaying afferent impulses to higher centres; in the adult such neurons compose the sensory nuclei of the spinal cord and brainstem. Synonym: lamina alaris, alar plate of neural tube, dorsolateral plate of neural tube, lamina dorsalis, wing plate. (05 Mar 2000) |
| anal plate | The anal portion of the cloacal plate. (05 Mar 2000) |
| axial plate | The primitive streak of an embryo. (05 Mar 2000) |
| basal plate of neural tube | The ventral division of the lateral walls of the neural tube in the embryo; it contains neuroblasts giving rise to somatic and visceral motor neurons. Synonym: lamina basalis, basal plate of neural tube, lamina ventralis, ventral plate of neural tube. (05 Mar 2000) |
| bone plate | A metal bar with perforations for the insertion of screws; used to immobilise fractured segments. (05 Mar 2000) |
| buttress plate | A metal plate used to support the internal fixation of a fracture. (05 Mar 2000) |