the standard unit in the International System of Units (SI) of dose equivalent having the same biological effect as one joule of x-rays per kilogram of recipient mass (or one gray):
The average person receives about 2 to 3 one-thousandths of a sievert per year from naturally occurring radiation in the environment.
the derived SI unit of dose equivalent, equal to 1 joule per kilogram. 1 sievert is equivalent to 100 rems Sv
(formerly) a unit of gamma radiation dose approximately equal to 8.4 × 10–2 gray
sievert sie·vert (sē’vərt)
Abbr. Sv A unit of ionizing radiation absorbed dose equivalent in the International System of Units, obtained as a product of the absorbed dose measure in grays and a dimensionless factor, stipulated by the International Commission on Radiological Protection, and indicating the biological effectiveness of the radiation.
The SI derived unit used to measure the amount of radiation necessary to produce the same effect on living tissue as one gray of high-penetration x-rays. The sievert is named after Swedish physicist Rolf Sievert (1896-1966).
noun, Botany. 1. a vertical series of sieve cells in the phloem, specialized for the conduction of food materials. 2. a single sieve cell. noun 1. (botany) an element of phloem tissue consisting of a longitudinal row of thin-walled elongated cells with perforations in their connecting walls through which food materials pass
- Sieve-tube element
sieve-tube element An elongated, food-conducting cell in phloem in angiosperms. Unlike the tracheary elements of xylem, sieve elements have living protoplasts when mature, but they lack a nucleus and are dependent upon companion cells for certain functions. At the ends of each sieve-tube element are sieve plates, areas of the cell wall containing numerous large […]
noun 1. an instrument with a meshed or perforated bottom, used for separating coarse from fine parts of loose matter, for straining liquids, etc., especially one with a circular frame and fine meshes or perforations. 2. a person who cannot keep a secret. verb (used with or without object), sieved, sieving. 3. to put or […]
adjective 1. (South African, slang) disgusting; sickening; nasty SIF somatotropin release-inhibiting factor