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Sigma KEE - Sievert
SI dose equivalent measure. Symbol: Sv. It is a unit of biologic dose of ionizing radiation. The Sievert makes it possible to normalize doses of different types of radiation. It takes into account the relative biologic effectiveness of ionizing radiation, since each form of such radiation--e.g., X rays, gamma rays, neutrons-- has a slightly different effect on living tissue for a given absorbed dose. The dose equivalent of a given type of radiation (in Sievert) is the dose of the radiation in Gray multiplied by a quality factor that is based on the relative biologic effectiveness of the radiation. Accordingly, one Sievert is generally defined as the amount of radiation roughly equivalent in biologic effectiveness to one Gray of gamma radiation. Sievert = J/kg = m^2*s^(-2).
InstancesabstractProperties or qualities as distinguished from any particular embodiment of the properties/qualities in a physical medium. Instances of Abstract can be said to exist in the same sense as mathematical objects such as sets and relations, but they cannot exist at a particular place and time without some physical encoding or embodiment.
 CompositeUnitOfMeasureInstances of this Class are UnitsOfMeasure defined by the functional composition of other units, each of which might be a CompositeUnitOfMeasure or a NonCompositeUnitOfMeasure.
 entityThe universal class of individuals. This is the root node of the ontology.
 function quantityA FunctionQuantity is a PhysicalQuantity that is returned by a Function that maps from one or more instances of ConstantQuantity to another instance of ConstantQuantity. For example, the velocity of a particle would be represented by a FunctionQuantity relating values of time (which are instances of ConstantQuantity) to values of distance (also instances of ConstantQuantity). Note that all elements of the range of the Function corresponding to a FunctionQuantity have the same physical dimension as the FunctionQuantity itself.
 physical quantityA PhysicalQuantity is a measure of some quantifiable aspect of the modeled world, such as 'the earth's diameter' (a constant length) and 'the stress in a loaded deformable solid' (a measure of stress, which is a function of three spatial coordinates). Every PhysicalQuantity is either a ConstantQuantity or FunctionQuantity. Instances of ConstantQuantity are dependent on a UnitOfMeasure, while instances of FunctionQuantity are Functions that map instances of ConstantQuantity to other instances of ConstantQuantity (e.g., a TimeDependentQuantity is a FunctionQuantity). Although the name and definition of PhysicalQuantity is borrowed from physics, a PhysicalQuantity need not be material. Aside from the dimensions of length, time, velocity, etc., nonphysical dimensions such as currency are also possible. Accordingly, amounts of money would be instances of PhysicalQuantity. A PhysicalQuantity is distinguished from a pure Number by the fact that the former is associated with a dimension of measurement.
 quantityAny specification of how many or how much of something there is. Accordingly, there are two subclasses of Quantity: Number (how many) and PhysicalQuantity (how much).
 systeme international unitThe Class of Systeme International (SI) units.
 unit of measureA standard of measurement for some dimension. For example, the Meter is a UnitOfMeasure for the dimension of length, as is the Inch. There is no intrinsic property of a UnitOfMeasure that makes it primitive or fundamental, rather, a system of units (e.g. SystemeInternationalUnit) defines a set of orthogonal dimensions and assigns units for each.
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