Radiation physical unit

Two methods, physical and biological, are used to describe quantities of radiation. Physical units indicate the activity of a source of radiation, typically in terms of the number of nuclei that decay per unit of time. Biological units are related to the damage caused by radiation and account for the fact that a given quantity (or number of particles) of one type of radiation does not have the same damaging effect on tissue as the same quantity of another type of radiation. 

Daryl R. Myers is a Senior Scientist at NREl. In 1970 He received a Bachelor of Science in Applied Mathematics from the University of Colorado, Boulder, School of Engineering. Prior to joining NREL in 1978, he worked for four years at the Smithsonian Institution Radiation Biology Laboratory in Rockville Maryland, and is a Cold War veteran, serving as a Russian linguist in the United States Army from 1970 to 1974. He has over 32 years of experience in terrestrial broadband and spectral solar radiation physics, measurement instrumentation, metrology... 

The physical meaning of the terms in this equation can be inferred from the above modeling analysis. The term on the LHS denotes the rate of accumulation of internal and kinetic energy within the control volume per unit volume the first term on the RHS denotes the net rate of of internal and kinetic energy increase by convection per unit volume the second term on the RHS denotes the net rate of heat addition due to heat conduction, interdiffusion effects, Dufour effects and radiation per unit volume the third term on the RHS denotes the rate of work done on the fluid within the control volume by external body forces per unit volume the fourth term on the RHS denotes the rate of work done on the fluid within the control volume by the pressure forces per unit volume and the fifth term on the RHS denotes the rate of work done on the fluid within the control volume by the viscous forces per unit volume. 

Several terms are used to express the intensity of radiation (see Figure 9.8). Radiation level is a term often substituted for dose rate or exposure rate. It is generally referred to as the effect of radiation on matter i.e., the amount of radiation that is imparted from the source and absorbed by matter due to emitted radiation per unit of time. The curie is a radiological term for the physical amount of a radioactive material. A curie consists of 37 billion disintegrations per second. It is a physical amount of material that is required to produce a specific amount of ionizing radiation ... 

Table 1.2-3 summarizes the names, definitions, and SI units for the most frequently used radiometric and photometric quantities in radiation physics. 

A physical unit of radiation, such as a curie, indicates the activity of a source of radiation in terms of the number of nuclear decays that occur per minute. A biological unit of radiation, such as a rem, indicates the damage caused by radiation in living tissue. 

DIN 5031-3 1982-03, Optical radiation physics and illuminating engineering quantities, symbols and units of illuminating engineering... 

The method is based on the international standard ISO 4053/IV. A small amount of the radioactive tracer is injected instantaneously into the flare gas flow through e.g. a valve, representing the only physical interference with the process. Radiation detectors are mounted outside the pipe and the variation of tracer concentration with time is recorded as the tracer moves with the gas stream and passes by the detectors. A control, supply and data registration unit including PC is used for on site data treatment... 

The yield of cross-linking depends on the microstructure of polybutadiene and purity of the polymer as well as on whether it is irradiated in air or in vacuum. The cross-link yield, G(X), has been calculated to be lowest for trans and highest for vinyl isomer [339]. The introduction of styrene into the butadiene chain leads to a greater reduction in the yield of cross-linking, than the physical blends of polybutadiene and polystyrene [340]. This is due to the intra- and probably also intermolecular energy transfer from the butadiene to the styrene constituent and to the radiation stability of the latter unit. 

Rep—Roentgen equivalent, physical A former unit of ionizing radiation equivalent to the dosage of 93 ergs absorbed per gram of tissue (93 erg/gm=0.93 rad). 

Max Planck (1858-1947 Nobel Prize for physics 1918) at first did not have the atom in his sights. He was more interested in thermodynamics, and especially in the laws of radiation. In 1900 he surprised the Physical Society of Berlin — and later the whole world — with an experimentally based realization that changed the world view. In contrast to time and space, energy is guantized. Thus it does not form a continuum, but is essentially "grainy". The smallest unit is the Planck constant, a fundamental natural constant. 

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