| beam tree | <botany> A tree (Pyrus aria) related to the apple. Origin: AS. Beam a tree. See: Beam. Source: Websters Dictionary (01 Mar 1998) |
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| beam-wall reaction | <radiobiology> Fusion reaction which occurs from the collision of a fast beam ion with an ion embedded in or adsorbed onto the reactor wall. (09 Oct 1997) |
| cantilever beam | In dentistry, a beam that is supported by only one fixed support at only one of its ends. (05 Mar 2000) |
| restrained beam | In dentistry, a beam that has two or more supports, at least one of which permits some freedom of rotation to the point of support but not as much as if the support were a free support. (05 Mar 2000) |
| continuous beam | In dentistry, a beam that continues over three or more supports, those supports not at the beam ends being equally free supports. (05 Mar 2000) |
| Convergent Beam Electron Diffraction | <microscopy> An electron probe is tightly focused on a transmission electron microscopy specimen and the resulting pattern of diffracted electrons is observed. The patterns contains information on the crystal symmetry and atomic and electronic structure of the sample. Regions as small as 0.2 nm may be examined. Acronym: CBED (05 Aug 1998) |
| horizontal beam film | A radiograph made with the central axis of the X-ray beam parallel to the floor, able to show an air-fluid level. (05 Mar 2000) |
| simple beam | In dentistry, a straight beam that has only two supports, one at either end. (05 Mar 2000) |
| neutral axis of straight beam | The axis perpendicular to the plane of loading of a beam at stresses within the proportional limit; it lies at the gravity axis of the cross-section of the beam. (05 Mar 2000) |
| neutral beam injection | <radiobiology> This is one of the fundamental plasma heating methods. A particle accelerator is used to create fast ion beams (the particle energies are on the order of 100 keV), the ion beam is then passed through a neutral gas region, where the ions neutralise via charge-exchange reactions with the neutral gas. The neutralised beam is then injected into a magnetically confined plasma. The neutral atoms are unaffected (not confined) by the magnetic field, but ionize as they penetrate into the plasma. The high-energy ions then transfer some of their energy to the plasma particles in repeated collisions, and heat the plasma. (09 Oct 1997) |
| electron beam | <microscopy> A stream of electrons in an electron optical system. (05 Aug 1998) |
| abnormalities, radiation-induced | Congenital changes in the morphology of organs produced by exposure to ionizing or non-ionizing radiation. (12 Dec 1998) |
| accidents, radiation | Accidental dispersal of radioactive materials from a radiation source. Accidents at nuclear reactors can involve large groups of the population from dispersion of radioactivity into the environment and through fallout or a few individuals with high injurious doses. (12 Dec 1998) |
| acoustic radiation | The fibres that pass from the medial geniculate body to the transverse temporal gyri of the cerebral cortex by way of the sublentiform part of the internal capsule. Synonym: radiatio acustica. (05 Mar 2000) |
| acute radiation syndrome | <syndrome> A syndrome caused by exposure of the body to large amounts of radiation, (e.g., from certain forms of therapy, accidents, and nuclear explosions; it is divided into three major forms which are, in ascending order of severity, the haematogic, gastrointestinal, and central nervous system-cardiovascular forms; its clinical manifestations are divided into prodromal, latent, overt, and recovery stages. (05 Mar 2000) |