| X-rays | Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release energy - in the same energy range as gamma rays (0.010-10 mev), but of non-nuclear origin, of shorter wavelength than ultraviolet; soft X-rays or grenz rays are less penetrating and longer in wavelength than hard X-rays. (12 Dec 1998) |
|---|---|
| secondary rays | X-ray's generated when primary X-ray's impinge upon matter; scattered radiation. (05 Mar 2000) |
| H rays | <physics> A stream of hydrogen nuclei; i.e., protons. (05 Mar 2000) |
| soft rays | X-ray's of relatively long wavelength and slight penetrability. (05 Mar 2000) |
| Niewenglowski rays | Radiation emitted from a phosphorescent body after exposure to sunlight. (05 Mar 2000) |
| supersonic rays | Ray's with a wavelength higher than that perceptible to the human ear, above 20,000 Hz. (05 Mar 2000) |
| Dorno rays | The ultraviolet ray's with wavelengths below 289 nm; those biologically active. (05 Mar 2000) |
| indirect rays | X-ray's generated at a surface other than the anode target. (05 Mar 2000) |
| infrared rays | That portion of the electromagnetic spectrum usually sensed as heat. Infrared wavelengths are longer than those of visible light, extending into the microwave frequencies. They are used therapeutically as heat, and also to warm food in restaurants. (12 Dec 1998) |
| intermediate rays | Those between ultraviolet and X-ray's. Synonym: W rays. (05 Mar 2000) |
| ultrasonic rays | See: ultrasonic. (05 Mar 2000) |
| ultraviolet rays | That portion of the electromagnetic spectrum immediately below the visible range and extending into the X-ray frequencies. The longer wavelengths (near-uv or biotic or vital rays) are necessary for the endogenous synthesis of vitamin d and are also called antirachitic rays; the shorter, ionizing wavelengths (far-uv or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants. (12 Dec 1998) |
| non-direct transmission | <epidemiology> A mode of transmission that differs in some mysterious way from indirect transmission. (05 Dec 1998) |
| direct | 1. Straight, in a straight line. 2. Performed immediately and without the intervention of subsidiary means. Origin: L. Directus (18 Nov 1997) |
| direct acrylic restoration | A direct resin restoration of autopolymerizing acrylic. (05 Mar 2000) |