Search results
Results From The WOW.Com Content Network
Doctors also find certain diseases by injecting a radioactive substance and monitoring the radiation given off as the substance moves through the body. [8] Radiation used for cancer treatment is called ionizing radiation because it forms ions in the cells of the tissues it passes through as it dislodges electrons from atoms.
As ionizing radiation moves through matter its energy is deposited through interactions with the electrons of the absorber. [1] The result of an interaction between the radiation and the absorbing species is removal of an electron from an atom or molecular bond to form radicals and excited species. The radical species then proceed to react with ...
Radiative transfer (also called radiation transport) is the physical phenomenon of energy transfer in the form of electromagnetic radiation. The propagation of radiation through a medium is affected by absorption, emission, and scattering processes. The equation of radiative transfer describes these interactions mathematically. Equations of ...
The RTE is a differential equation describing radiance (, ^,).It can be derived via conservation of energy.Briefly, the RTE states that a beam of light loses energy through divergence and extinction (including both absorption and scattering away from the beam) and gains energy from light sources in the medium and scattering directed towards the beam.
For example, ionizing radiation is one cause of chronic myelogenous leukemia, [22] [23] [24] although most people with CML have not been exposed to radiation. [23] [24] The mechanism by which this occurs is well understood, but quantitative models predicting the level of risk remain controversial. [citation needed]
The second term describes absorption of radiation by the molecules in a short segment of the radiation's path (ds) and the first term describes emission by those same molecules. In a non-homogeneous medium, these parameters can vary with altitude and location along the path, formally making these terms n ( s ) , σ λ ( s ) , T ( s ) , and I λ ...
In electromagnetic radiation (such as microwaves from an antenna, shown here) the term radiation applies only to the parts of the electromagnetic field that radiate into infinite space and decrease in intensity by an inverse-square law of power, such that the total energy that crosses through an imaginary sphere surrounding the source is the ...
An overview of absorption of electromagnetic radiation.This example shows the general principle using visible light as a specific example. A white light source—emitting light of multiple wavelengths—is focused on a sample (the pairs of complementary colors are indicated by the yellow dotted lines).