Irradiation

(redirected from irradiating)
Also found in: Dictionary, Thesaurus, Medical.
Related to irradiating: eradicating

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.)
References in periodicals archive ?
The country has largely eliminated Salmonella contamination not by irradiating its poultry, but by using contaminant-free chicken feed, rat-proofed and disinfected pens, and other safeguards.
In 1982, FDA officials said that irradiating food with 1 kilogray of radiation was probably safe, but nothing has been done to study the effect of 7 kilograys, an amount it allowed for beef and lamb in 1997.
Estimated net social benefits (benefits minus costs) depend on the cost of irradiating ground beef and the extent of the foodborne illness prevented.
Net Benefits of Irradiating Ground Beef Depend on Cost(1) Assumed Range of Estimated Range of cost per estimated industry estimated pound to social costs net irradiate benefits(2) benefits(2) Cents Million 1996 dollars 1.
Table assumes that by irradiating 25 percent of the U.
They found that irradiating the cooked pork sausage in aerobic packaging may result in a loss of some meaty aroma.
The laser's light was used to create X rays for irradiating a tiny spherical capsule containing gaseous hydrogen fuel.
radiation therapist Timothy Kinsella has been irradiating patients with advanced, high-grade (generally incurable) glioblastoma brain tumors or other metastasized tumors.
A novel approach being studied at the State University of Campinas in Brazil involves irradiating the wastes with ultraviolet light (UV) and then feeding them to fungi newly isolated from the gut of a wood-eating insect.
But irradiating rice straw for an hour brought the biggest gain--an eightfold increase in fungal growth over untreated straw.