| emf | electromotive force |
|---|---|
| F | and R force and rhythm [of pulse] |
| FF | degree of fineness of abrasive particles; fat-free; father factor; fecal frequency; fertility factor... |
| F&R | force and rhythm [pulse] |
| FSR | Fellow of the Society of Radiographers; film screen radiography; force sensing resistor; fragmented ... |
shelf force
| negative focal length | <physics> The focal length of a negative lens. Parallel rays impinging on a negative lens can be traced to a virtual focus which exists on the same side of the lens as the impinging rays. The distance from the second principal point of the lens to this second focal point is measured on the same side of the lens as is the object. See: negative lens, focal length. (05 Aug 1998) |
|---|---|
| equivalent focal length | <microscopy> The focal length of the simple lens that has the same power as the compound lens. The stated focal lengths of microscope objectives are the equivalent focal length since their front and back focal lengths are very different. (05 Aug 1998) |
| unit of length | Metric system and SI: meter, CGS system: centimeter, variable in the English system: inch for short distances, foot for moderate distances and for elevation, mile for long distances. (05 Mar 2000) |
| focal length | <microscopy> The distance from the optical centre of the lens to the focal point<microscopy> The focal length of an objective and its working distance are directly proportional. (05 Aug 1998) |
| leg length inequality | A condition in which one of a pair of legs fails to grow as long as the other. (12 Dec 1998) |
| length | 1. The longest, or longer, dimension of any object, in distinction from breadth or width; extent of anything from end to end; the longest line which can be drawn through a body, parallel to its sides; as, the length of a church, or of a ship; the length of a rope or line. 2. A portion of space or of time considered as measured by its length; often in the plural. "Large lengths of seas and shores." (Shak) "The future but a length behind the past." (Dryden) 3. The quality or state of being long, in space or time; extent; duration; as, some sea birds are remarkable for the length of their wings; he was tired by the length of the sermon, and the length of his walk. 4. A single piece or subdivision of a series, or of a number of long pieces which may be connected together; as, a length of pipe; a length of fence. 5. Detail or amplification; unfolding; continuance as, to pursue a subject to a great length. "May Heaven, great monarch, still augment your bliss. With length of days and every day like this." (Dryden) 6. Distance. "He had marched to the length of Exeter." (Clarendon) at length. At or in the full extent; without abbreviation; as, let the name be inserted at length. At the end or conclusion; after a long period. See Syn. Of At last, under Last. At arm's length. See Arm. Origin: OE. Lengthe, AS. Leng, fr. Land, long, long; akin to D. Lengte, Dan. Laengde, Sw. Langd, Icel. Lengd. See Long. Source: Websters Dictionary (01 Mar 1998) |
| length-breadth index | The ratio of the maximal breadth to the maximal length of the head, obtained by the formula: (breadth × 100)/length. Synonym: length-breadth index. (05 Mar 2000) |
| length-height index | The relation of the height to the length of the skull: (height × 100)/length. Synonym: height-length index, length-height index, transversovertical index. (05 Mar 2000) |
| length of stay | The period of confinement of a patient to a hospital or other health facility. (12 Dec 1998) |
| accouchement force | Forced, artificially hastened delivery, by means of forceps, version, etc.; originally applied to rapid dilation of the cervix with the hands, with version and forcible extraction of the foetus. (05 Mar 2000) |
| anterior component of force | A force operating to move teeth anteriorly. (05 Mar 2000) |
| Begg light wire differential force technique | An orthodontic appliance utilizing small gauge labial wires with expansion and contraction loops formed into it and attached to bands fitted to individual teeth; sometimes called Begg light wire differential force technique. (05 Mar 2000) |
| bite force | The force applied by the masticatory muscles in dental occlusion. (12 Dec 1998) |
| brisement force | Forcible manipulation, usually under anaesthesia, in which the position of a deformed limb is corrected by tearing the soft tissue and crushing the bone, as in a once popular but no longer used correction for club foot deformities. Origin: Fr. Forcible breaking (05 Mar 2000) |
| radial ponderomotive force stabilisation | <radiobiology> In magnetic mirror devices, use of rf waves in the neighborhood of the ion cyclotron frequency to stabilise interchange modes. The radial ponderomotive force produced by a radial gradient in the applied rf electric field opposes the destabilising centrifugal force resulting from bad magnetic field curvature. The net particle current is in the direction that would result from field lines with good curvature, eliminating the drive for the interchange instability. (09 Oct 1997) |