Based on the Random House Dictionary, © Random House, Inc. 2012.
Cite This Source
00:10
00:09
00:08
00:07
00:06
00:05
00:04
00:03
00:02
00:01
| a particle having the same mass and spin as an electron but having a positive charge equal in magnitude to that of the electron's negative charge |
| a unit of energy, the work done by a force of one newton when its point of application moves through a distance of one meter in the direction of the force |
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
sievert sie·vert (sē'vərt)
n.
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.
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
sievert  (sē'vərt) Pronunciation Key
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). |
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
sievert
unit of radiation absorption in the International System of Units (SI). The sievert has been recommended by the International Commission on Radiation Units and Measurements (ICRU) as a substitute for the rem, the long-standing special unit for measuring biological absorption of radiation. Like the rem, the sievert takes into account the relative biologic effectiveness (RBE) of ionizing radiation, since each form of such radiation-e.g., X rays, gamma rays, neutrons-has a slightly different effect on living tissue. Accordingly, one sievert is generally defined as the amount of radiation roughly equivalent in biologic effectiveness to one gray (or 100 rads) of gamma radiation. The sievert is inconveniently large for various applications, and so the millisievert (mSv), which equals 11,000 sievert, is frequently used instead. One millisievert corresponds to 10 ergs of energy of gamma radiation transferred to one gram of living tissue.
Learn more about sievert with a free trial on Britannica.com.
Cite This Source
