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a former unit of absorbed ionizing radiation dose equivalent to an energy absorption per unit mass of 0.01 joule per kilogram of irradiated material. 1 rad is equivalent to 0.01 gray
a subsidiary unit of absorbed radiation dose. It is applied to any kind of ionizing radiation and corresponds to a radiant energy of 100 ergs absorbed by 1 g of a substance: 1 rad = 2.388 × 10–6 = 0.01 joule per kg.
A special unit of absorbed dose, equal to energy absorption of 100 ergs per gram (0.01 joule per kilogram); equal to 0.01 gray.
A heating unit usually exposed to view within the room or space to be heated; transfers heat by radiation to objects within visible range, and by conduction to the surrounding air, which in turn is circulated by natural convection; usually fed by steam or hot water.
RAD(1) (Rapid Application Development) Developing systems incrementally and delivering working pieces every three to four months, rather than waiting until the entire project is programmed before implementing it. Over the years, many information projects have failed, because, by the time the implementation took place, the business had changed.
RAD employs a variety of automated design and development tools, including CASE, 4GLs, visual programming and GUI builders, all of which help create prototypes and running applications faster than by coding program statements a line at a time. The term was coined years ago by industry guru James Martin and focuses on personnel management and user involvement as much as on technology. Joint application development is another RAD concept (see JAD).
The term is also used in a more general way to refer to an environment that produces applications quickly and efficiently.
(2) (RADiation dose) An earlier unit of measurement of absorbed radiation. Defined in the centimeter-gram-second (CGS) system as equal to 100 ergs of energy absorbed by one gram of matter, the rad was superseded by the "gray," an SI unit where 100 rad are equal to one gray. See radiation hardened and gray.