Irradiation


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Related to Irradiation: gamma irradiation, Blood Irradiation

irradiation

[i‚rād·ē′ā·shən]
(biophysics)
Subjection of a biological system to sound waves of sufficient intensity to modify their structure or function.
(engineering)
The exposure of a material, object, or patient to x-rays, gamma rays, ultraviolet rays, or other ionizing radiation.
(optics)
An optical illusion which makes bright objects appear larger than they really are.

Irradiation

 

in physiology, the spread of excitation or inhibition in the central nervous system. Irradiation plays an important part in cerebrocortical activity. The irradiation of excitation is manifested most distinctly after strong stimulation, when nerve centers usually not involved in a reflex response are drawn into the process. For example, moderate pain inflicted on the skin of an animal’s foot causes the paw to flex in the talocalcaneal joint. Increasing the force of stimulation causes the leg to flex in the knee and hip joints. In studying the effect of an inhibitory conditioned stimulus, I. P. Pavlov showed that inhibition can also spread (irradiate) in the cells of the cerebral cortex.


Irradiation

 

the apparent enlargement of the dimensions of white (light) objects against a black (dark) background (given the comparatively great brightness of the white object) or, conversely, the apparent diminution of the dimensions of black objects against a white background. (The first instance is called positive irradiation; the second, negative.)

As a result of irradiation, a thin black thread or wire observed against a bright flame seems to be interrupted in that segment, and the bright crescent of the new moon seems to have a larger diameter than the ash-gray disk of the moon seen simultaneously with it. The degree of irradiation increases when the brightness of the light background or object increases. Irradiation is caused by optical defects of the eye (spherical and chromatic aberrations), diffraction phenomena in the eye, and imperfect fixation of the eye on the objects observed.

REFERENCE

Kravkov, S. V. Glaz i ego rabota: Psikhofiziologiia zreniia, gigiena osvesh-cheniia, 4th ed. Moscow-Leningrad, 1950. (Includes bibliography.)
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The study included 79 patients who had been free of Hodgkin lymphoma for at least 10 years and had received mediastinal irradiation 20 years ago, plus 273 controls without Hodgkin lymphoma or irradiation.
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Gamma Irradiation Technology can not only enhance shelf life of fruits, vegetables and other food items but could also help overcome the issue of fruit fly in mangos which had badly affected the export of Pakistani mango".
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ISO 14470:2011, Food irradiation - Requirements for the development, validation and routine control of the process of irradiation using ionizing radiation for the treatment of food, not only provides requirements, but also guidance for meeting them.
A: Food irradiation is sometimes called "cold pasteurization.
A typical coil irradiation system is shown in Photo 1.
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