| magnetic switching | <radiobiology> The use as switches of saturable inductors for producing high power pulses without electrical arcs. This is a principal technology for extending single-shot accelerators in light-ion-beam-driven inertial confinement fusion to repetitively pulsed devices for possible reactors. Three terawatt, 200 KJ magnetic switches have been developed for fusion drivers at Sandia National Laboratories. (Info from the 1985 OSTI Glossary of Fusion Energy, may be out of date.) (09 Oct 1997) |
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| magnetic viscosity | <physics> A magnetic field in a conducting fluid will damp fluid motions perpendicular to the field lines, similar to ordinary viscosity, even in the absence of sizeable mechanical forces or electric fields. (09 Oct 1997) |
| nuclear magnetic resonance | Spectroscopic method of measuring the magnetic moment of atomic nuclei in a covalent bond. Clinical application is in biochemical, metabolic, and physiologic studies of living tissue. It includes proton and electron spin-echo and spin-relaxation times. (12 Dec 1998) |
| nuclear magnetic resonance, biomolecular | Nmr spectroscopy on small- to medium-size biological macromolecules. This is often used for structural investigation of proteins and nucleic acids, and often involves more than one isotope. (12 Dec 1998) |
| nuclear magnetic resonance imaging | A special imaging technique used to image internal stuctures of the body, particularly the soft tissues. An MRI image is often superior to a normal X-ray image. It uses the influence of a large magnet to polarize hydrogen atoms in the tissues and then monitors the summation of the spinning energies within living cells. Images are very clear and are particularly good for soft tissue, brain and spinal cord, joints and abdomen. These scans may be used for detecting some cancers or for following their progress. Acronym: MRI (11 Nov 1997) |
| nuclear magnetic resonance tomography | A special imaging technique used to image internal stuctures of the body, particularly the soft tissues. An MRI image is often superior to a normal X-ray image. It uses the influence of a large magnet to polarize hydrogen atoms in the tissues and then monitors the summation of the spinning energies within living cells. Images are very clear and are particularly good for soft tissue, brain and spinal cord, joints and abdomen. These scans may be used for detecting some cancers or for following their progress. Acronym: MRI (11 Nov 1997) |
| toroidal magnetic cusps | A hybrid confinement scheme operating at high beta. A region of closed toroidal magnetic flux with high-beta plasma is separated by a narrow sheath from the surrounding field, which contains externally produced poloidal components arranged in a toroidal line-cusp configuration. Plasma migrating to the outer sheath is temporarily mirror-confined before being removed in a divertor system. (09 Oct 1997) |
| unit of magnetic field intensity | See: gauss, tesla. (05 Mar 2000) |
| lens, magnetic | <microscopy> Circular electromagnets capable of projecting a precise circular magnetic field in a specified region. The field acts like an optical lens, having the same attributes (focal length angle of divergence etc.) and errors (spherical aberration, chromatic aberration, astigmatism etc.). They are used to focus and steer electrons in an Electron Microscope. (05 Aug 1998) |
| atomic volume | The atomic weight of an element divided by its density in the solid state; the volume of the gram-atomic weight of a solid element. (05 Mar 2000) |
| blood volume | Volume of circulating blood. It is the sum of the plasma volume and erythrocyte volume. (12 Dec 1998) |
| blood volume determination | Method for determining the circulating blood volume by introducing a known quantity of foreign substance into the blood and determining its concentration some minutes later when thorough mixing has occurred. From these two values the blood volume can be calculated by dividing the quantity of injected material by its concentration in the blood at the time of uniform mixing. Generally expressed as cubic centimeters or liters per kilogram of body weight. (12 Dec 1998) |
| blood volume nomogram | A nomogram used to predict blood volume on the basis of the individual's weight and height. (05 Mar 2000) |
| cardiac volume | The volume of the heart, usually relating to the volume of blood contained within it at various periods of the cardiac cycle. The amount of blood ejected from a ventricle at each beat is stroke volume. (12 Dec 1998) |
| packed cell volume | <haematology> Measurement of the proportion of the blood occupied by the red blood cells. Normal values are 40-54% in males, 35-47% in females. (13 Nov 1997) |