Also known as: RA#, RA...
RA has various meanings in the Science category. Discover the full forms, definitions, and usage contexts of RA in Science.
A radioactive decay product of uranium often found in uranium ore. It has several radioactive isotopes. Radium-226 decays to radon-222. A radioactive element which the chemical symbol Ra; radium and its salts are used in gamma ray radiography because of their radioactivity. Melting point is 700 B0C (1292 B0F).
ScienceThe amount of time that passes between the rising of Aries and another celestial object. Right ascension is one unit of measure for locating an object in the sky. Measurement of a heavenly body's distance from from First Point of Aries, and expressed in terms of sidereal time.
ScienceAny part of an installation accessible to employees in which there exists a radiation level of 7.5 millirem in any one hour over 150 millirem in any seven consecutive days. Any area with radiation levels greater than 5 millirems (0.05 millisievert) in one hour at 30 centimeters from the source or from any surface through which the radiation penetrates.
ScienceThe number of organisms of a particular kind as a percentage of the total number of organisms of a given area or community, the number of birds of a particular species as a percentage of the total bird population of a given area.
ScienceMeasure in LSB of the accuracy of an ADC. It includes all non-linearity and quantization errors.
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