| radioactive isotope | <physics, radiobiology> An isotope of an element that has an unstable nucleus, it tries to stabilise itself by giving off ionising radiation. (09 Oct 1997) |
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| radioactive pollutants | Radioactive substances which act as pollutants. They include chemicals whose radiation is released via radioactive waste, nuclear accidents, fallout from nuclear explosions, and the like. (12 Dec 1998) |
| radioactive probe | A nucleic acid fragment, labelled by a radioisotope, biotin, etc., that is complementary to a sequence in another nucleic acid (fragment) and that will, by hydrogen binding to the latter, locate or identify it and be detected; a diagnostic technique based on the fact that every species of microbe possesses some unique nucleic acid sequences which differentiate it from all others, and thus can be used as identifying markers or "fingerprints." (05 Mar 2000) |
| radioactive thyroxine | Thyroxine in which a radioisotope of iodine (125I or 131I) is incorporated into its molecule; used in experiments tracing the metabolism of thyroxine. Synonym: labelled thyroxine, radiolabelled thyroxine, radiothyroxin. (05 Mar 2000) |
| radioactive tracer | <physics, radiobiology> A radioisotope is an element which has the same atomic number as another but a different atomic weight, exhibiting the property of spontaneous decomposition. Decomposition gives off radiation (gamma rays) that can be detected with a counter. If a radioisotope is attached to a biological compound and injected into the body, its path may be traced through the body (resulting in an image). (27 Sep 1997) |
| radioactive tracers | Radioactive substances added in minute amounts to the reacting elements or compounds in a chemical process and traced through the process by appropriate detection methods, e.g., geiger counter. Compounds containing tracers are often said to be tagged or labelled. (12 Dec 1998) |
| radioactive waste | <radiobiology> Equipment and materials from nuclear operations which are radioactive and for which there is no further anticipated use. Wastes are generally classified as high-level (having radioactivity concentrations of hundreds to thousands of curies per gallon or cubic foot), low-level (in the range of 1 microcurie per gallon or cubic foot), or intermediate (between high and low). See: curie. (09 Oct 1997) |
| gold colloid, radioactive | <chemical> A radioactive suspension of minute particles of metallic gold, made by exposure to neutrons. It is used in the pleural cavity to treat lung cancer. Pharmacological action: antineoplastic agent, radiopharmaceuticals. (12 Dec 1998) |
| rose bengal radioactive test | A test of liver function used as a means of measuring hepatic blood flow and for scintillation scanning of the liver to determine size and contour of the liver, or the presence of space-occupying masses in the liver. (05 Mar 2000) |
| colloidal radioactive gold | A radioactive isotope of gold emitting negative beta particles and gamma radiation, with a half-life of 2.7 days; formerly used for irradiation of closed serous cavities in the palliative treatment of ascites and pleural effusion due to metastatic malignancies, and for liver scans. Synonym: 198Au colloid, colloidal radioactive gold. (05 Mar 2000) |
| soil pollutants, radioactive | Pollutants, present in soil, which exhibit radioactivity. (12 Dec 1998) |
| elements, radioactive | Chemical elements which spontaneously transmute into another element with corpuscular or electromagnetic radiation. The natural radioactive elements are all those with an atomic number above 83, and some other elements, such as potassium (atomic number 19) and rubidium (atomic number 7), which are very weakly radioactive. (12 Dec 1998) |
| alkaline water | A water that contains appreciable amounts of the bicarbonates of calcium, lithium, potassium, or sodium. (05 Mar 2000) |
| aromatic water | 1. To wet or supply with water; to moisten; to overflow with water; to irrigate; as, to water land; to water flowers. "With tears watering the ground." (Milton) "Men whose lives gilded on like rivers that water the woodlands." (Longfellow) 2. To supply with water for drink; to cause or allow to drink; as, to water cattle and horses. 3. To wet and calender, as cloth, so as to impart to it a lustrous appearance in wavy lines; to diversify with wavelike lines; as, to water silk. Cf. Water. 4. To add water to (anything), thereby extending the quantity or bulk while reducing the strength or quality; to extend; to dilute; to weaken. To water stock, to increase the capital stock of a company by issuing new stock, thus diminishing the value of the individual shares. Cf. Water. Origin: AS. Waeterian, gewaeterian. 1. The fluid which descends from the clouds in rain, and which forms rivers, lakes, seas, etc. "We will drink water." ."Powers of fire, air, water, and earth." . Pure water consists of hydrogen and oxygen, H2O, and is a colourless, odorless, tasteless, transparent liquid, which is very slightly compressible. at its maximum density, 39 deg Fahr. Or 4 deg C, it is the standard for specific gravities, one cubic centimeter weighing one gram. It freezes at 32 deg Fahr. Or 0 deg C. And boils at 212 deg Fahr. Or 100 deg C. (see Ice, Steam). It is the most important natural solvent, and is frequently impregnated with foreign matter which is mostly removed by distillation; hence, rain water is nearly pure. It is an important ingredient in the tissue of animals and plants, the human body containing about two thirds its weight of water. 2. A body of water, standing or flowing; a lake, river, or other collection of water. "Remembering he had passed over a small water a poor scholar when first coming to the university, he kneeled." (Fuller) 3. Any liquid secretion, humor, or the like, resembling water; especially, the urine. 4. <pharmacology> A solution in water of a gaseous or readily volatile substance; as, ammonia water. 5. The limpidity and luster of a precious stone, especially a diamond; as, a diamond of the first water, that is, perfectly pure and transparent. Hence, of the first water, that is, of the first excellence. 6. A wavy, lustrous pattern or decoration such as is imparted to linen, silk, metals, etc. See Water, 3, Damask, and Damaskeen. 7. An addition to the shares representing the capital of a stock company so that the aggregate par value of the shares is increased while their value for investment is diminished, or "diluted." Water is often used adjectively and in the formation of many self-explaining compounds; as, water drainage; water gauge, or water-gauge; waterfowl, water-fowl, or water fowl; water-beaten; water-borne, water-circled, water-girdled, water-rocked, etc. Hard water. See Hard. Inch of water, a unit of measure of quantity of water, being the quantity which will flow through an orifice one inch square, or a circular orifice one inch in diameter, in a vertical surface, under a stated constant head; also called miner's inch, and water inch. The shape of the orifice and the head vary in different localities. In the Western United States, for hydraulic mining, the standard aperture is square and the head from 4 to 9 inches above its center. In Europe, for experimental hydraulics, the orifice is usually round and the head from 1/12 of an inch to 1 inch above its top. Mineral water, waters which are so impregnated with foreign ingredients, such as gaseous, sulphureous, and saline substances, as to give them medicinal properties, or a particular flavor or temperature. Soft water, water not impregnated with lime or mineral salts. To hold water. See Hold, To keep one's head above water, to keep afloat; fig, to avoid failure or sinking in the struggles of life. To make water. To pass urine. <medicine> Hydrothorax. Other phrases, in which water occurs as the first element, will be found in alphabetical order in the Vocabulary. Origin: AS. Waeter; akin to OS. Watar, OFries. Wetir, weter, LG. & D. Water, G. Wasser, OHG. Wazzar, Icel. Vatn, Sw. Vatten, Dan. Vand, Goth. Wat, O. Slav. & Russ. Voda, Gr, Skr. Udan water, ud to wet, and perhaps to L. Unda wave. Cf. Dropsy, Hydra, Otter, Wet, Whisky. Source: Websters Dictionary (01 Mar 1998) |
| baryta water | A saturated aqueous solution of barium hydroxide; used as an alkaline reagent. (05 Mar 2000) |