| HU | heat unit; hemagglutinating unit; hemolytic unit; Hounsfield unit; human urine, human urinary; hydro... |
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| TU | thiouracil; thyroid uptake; Todd unit; toxin unit; transmission unit; transurethral; tuberculin unit... |
| RI | radiation intensity; radioactive isotope; radioimmunology; recession index; recombinant inbred [stra... |
| FU | fecal urobilinogen; fetal urobilinogen; fluorouracil; follow-up; flux unit [ion]; fractional urinaly... |
| B0 | constant magnetic field in nuclear magnetic resonance |
| flux, light | <microscopy> Sometimes called luminous flux, the visible portion of the radiant energy emitted by a light source. It is measured in lumens per solid angle. In electrical engineering, it is analogous to the lines of force in a magnetic field, spoken of as magnetic flux. (05 Aug 1998) |
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| flux ratio | The ratio of the two unidirectional fluxes through a particular boundary layer or membrane. (05 Mar 2000) |
| luminous flux | The quantity of light emitted from a point source in a given time; its unit is the lumen. (05 Mar 2000) |
| magnetic | 1. A magnet. "As the magnetic hardest iron draws." (Milton) 2. Any metal, as iron, nickel, cobalt, etc, which may receive, by any means, the properties of the loadstone, and which then, when suspended, fixes itself in the direction of a magnetic meridian. Source: Websters Dictionary (01 Mar 1998) |
| magnetic attraction | The force that draws iron or steel toward a magnet. (05 Mar 2000) |
| magnetic axis | <physics> This typically refers to the location of the innermost flux surface in a toroidal device, the one which encloses no volume and has therefore degenerated from a flux surface into a single field line. Roughly, the circle through the middle of the dough of the donut. Additionally, in systems with magnetic islands (see entry below), each island has a local magnetic axis, distinct from the overall magnetic axis of the torus. (09 Oct 1997) |
| magnetic confinement | <physics> Use of magnetic fields to confine a plasma. (Confinement involves restricting the volume of the plasma and/or restricting particle or energy transport from the centre of the plasma to the edge.) (09 Oct 1997) |
| magnetic confinement fusion | <physics> Method of fusion which uses magnetic fields / magnetic bottles to confine a hot plasma until fusion occurs. (09 Oct 1997) |
| magnetic field | The sphere of influence of a magnet. (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) |
| magnetic implant | A tissue-tolerated, magnetised metal placed within the bone to aid in denture retention; a similar magnet is placed in the overlying denture to complete the field. (05 Mar 2000) |
| magnetic inertia | <physics> A lagging or retardation of the effect, when the forces acting upon a body are changed, as if from velocity or internal friction; a temporary resistance to change from a condition previously invuced, observed in magnetism, thermoelectricity, etc, on reversal of polarity. Origin: NL, fr. Gr. To be behind, to lag. Source: Websters Dictionary (01 Mar 1998) |
| magnetic island | <physics> A magnetic topology near a rational surface where the flux surface is broken up into tubes which are not connected with each other poloidally. Islands may develop in non-ideal magnetohydrodynamic fluids, where electrical resistance becomes important and magnetic field lines are no longer frozen-in to the fluid. Then magnetic tearing and reconnection may allow field lines to link up and form islands with a local magnetic axis in a narrow region near a rational surface. (See also magnetohydrodynamic, frozen-in law). The development of islands may be caused by a small perturbation, whether internal or external, whether deliberate or accidental, and is usually associated with enhanced transport (i.e., reduced confinement). The centres of the islands are magnetic O-points, while the boundaries between islands are marked by X-points. (09 Oct 1997) |
| magnetic mach number | <physics> A dimensionless number equal to the ratio of the velocity of a fluid to the velocity of Alfven waves in that fluid. (13 Nov 1997) |
| magnetic moment | <physics> (a) A vector associated with a magnet, current loop, or particle, the cross product of this vector with the magnetic field is equal to the torque which the field exerts on the system. (b) The adiabatic invariant associated with the rapid gyromotion of a charged particle in a slowly varying magnetic field. (The value of the magnetic moment in sense (b) is the magnitude of the vector in sense (a).) (13 Nov 1997) |