thermal radiation


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radiation

(rad-e-a'shon) [L. radiatio, a shining]
1. The process by which energy is propagated through space or matter.
2. The emission of rays in all directions from a common center.
3. Ionizing rays used for diagnostic or therapeutic purposes. Two types of radiation therapy are commonly used for patients with cancer: teletherapy and brachytherapy. See: brachytherapy
4. Any form of radiant energy emission or divergence, as of energy in all directions from luminous bodies, radiographical tubes, particle accelerators, radioactive elements, and fluorescent substances.
5. In neurology, a group of fibers that diverge from a common origin.

acoustic radiation

Auditory radiation.

actinic radiation

Ionizing electromagnetic radiation that can produce chemical changes, e.g., the damage done to skin by ultraviolet sunlight.

auditory radiation

A band of fibers that connect auditory areas of the cerebral cortex with the medial geniculate body of the thalamus. Synonym: acoustic radiation

background radiation

Total radioactivity from cosmic rays, natural radioactive materials, and other radiation that is present in a specific area.

braking radiation

Synonym: bremsstrahlung radiation

bremsstrahlung radiation

Diagnostic radiation produced at the target of the anode in an x-ray tube. An electron is accelerated at high speed from the x-ray tube cathode filament. It interacts with the nuclear field of a target atom, changing direction and losing energy that is emitted in the form of an ionizing radiation photon. The result is a heterogeneous beam.
Synonym: braking radiation

characteristic radiation

In radiology, the production of radiation in an anode caused by an interaction between an electron from the electron stream and an inner-shell electron of the target material. The result is an ejected electron, a positive atom, and an x-ray photon characteristic of the difference in binding energies between the atomic shells.

radiation of corpus callosum

All the fibers emanating from the corpus callosum into each cerebral hemisphere.

corpuscular radiation

Radiation composed of discrete elements or particles such as elements of atomic nuclei, i.e., alpha, beta, neutron, positron, or proton particles.

cosmic radiation

Ionizing radiation from the sun and other extraterrestrial sources. It has a short wavelength, high velocity, and an exceptional ability to penetrate tissue. It accounts for about one tenth of the yearly total of ionizing radiation exposure for each person. Colloquially, it is known as “cosmic rays.”

electromagnetic radiation

Photons that travel at the speed of light. They exhibit both magnetic and electrical properties.
See: electromagnetic spectrum for table

heterogeneous radiation

Radiation containing waves of various wavelengths.

homogeneous radiation

Radiation containing photons of similar wavelength.

infrared radiation

Infrared ray.

interstitial radiation

Radiation treatment accomplished by inserting sealed sources of a particle emitter directly into tissues.

ionizing radiation

Electromagnetic waves capable of producing ions after interaction with matter. Examples include x-rays, gamma rays, and beta particles.
See: ionizing radiation injury

irritative radiation

An overdose of ultraviolet irradiation resulting in erythema and, in exceptional cases, blister formation.

low-level radiation

Electromagnetic waves at intensity levels below that known to cause obvious damage to living things. Low-level radiation includes that emitted by power lines, nuclear power plants, and appliances such as electric blankets, television sets, and computer terminals.

nonionizing radiation

Abbreviation: NIR
Electromagnetic radiation that does not readily ionize atoms such as that in visible light, ultraviolet light, infrared light, microwaves, ultrasound, and radiofrequency emissions.

optic radiation

A system of fibers extending from the lateral geniculate body of the thalamus through the sublenticular portion of the internal capsule to the calcarine occipital cortex (striate area). Synonym: geniculocalcarine tract

photochemical radiation

Light rays that penetrate tissues only fractions of a millimeter, are absorbed by cells, and cause physical and biological changes. This type of radiation causes surface heating.

photothermal radiation

Radiation of heat by a source of light, as that from an electric bulb.

primary radiation

That radiation being emitted directly to the patient from an x-ray source.

pyramidal radiation

The radiation of fibers from the cerebral cortex to the pyramidal tract.

remnant radiation

Ionizing radiation that passes through the part being examined to make the radiographical image.

scattered radiation

X-rays that have changed direction because of a collision with matter.

secondary radiation

X-rays produced by the interaction between primary radiation and the substance being radiated.

solar radiation

Radiation from the sun; 60% is infrared and 40% is visible and ultraviolet.

spatially fractionated radiation

Abbreviation: SFR
Radiation treatment applied in high doses to a large tumor through a grid designed to direct energy into multiple discrete regions of the mass.

striatomesencephalic radiation

Fibers originating in the corpus striatum and terminating principally in the substantia nigra of the midbrain.

striatosubthalamic radiation

A system of fibers consisting of three groups that emerge from the medial aspect of the lentiform nucleus and enter the subthalamic region, most terminating there but some continuing into the midbrain. Synonym: ansa lenticularis

striatothalamic radiation

Groups of fibers connecting the corpus striatum with the thalamus and subthalamus.

synchrotron radiation

Radiation released by charged particles accelerated by a synchrotron. It may be used to obtain noninvasive images of body structures (e.g., the coronary arteries) or to study the structure of proteins, tissue samples, or other objects of biological or medical interest.

thalamic radiation

Groups of fibers connecting the thalamus with the cerebral hemispheres. These include frontal, centroparietal, occipital, and optic radiations.

thermal radiation

Heat radiation.

ultraviolet radiation

Radiant energy extending from 3900 to 200 angstrom units (A.U.) Divided into near ultraviolet, which extends from 3900 to 2900 A.U., and far ultraviolet, which extends from 2900 to 200 A.U.

visible radiation

The radiation of the visible spectrum, which may be broken up into different wavelengths representing different colors:

Violet, 3900–4550 angstrom units (A.U.)

Blue, 4550–4920 A.U.

Green, 4920–5770 A.U.

Yellow, 5770–5970 A.U.

Orange, 5970–6220 A.U.

Red, 6220–7700 A.U.

x radiation

1. A form of electromagnetic radiation with wavelengths in the range of 0.01 to 10 nm, frequencies from 3 × 1016 Hz to 3 × 1019 Hz, and energies in the range 120 eV to 120 keV.
2. Treatment with or exposure to x-rays.
References in periodicals archive ?
[38] examined the effects of variable thermal conductivity, thermal radiation and the thermal buoyancy on the unsteady fluid flow and heat transfer at a porous stretching sheet.
Increases in the thermal radiation dosage would necessarily also increase the blood temperature as mentioned earlier.
[54] investigated the effects of thermal-diffusion and thermal radiation on unsteady heat and mass transfer by free convective MHD micropolar fluid flow bounded by a semi-infinite vertical plate in a slip-flow regime under the action of transverse magnetic field with suction.
Takhar, "Effect of thermal radiation on MHD flow," Applied Mathematics and Computation, vol.
[T.sub.s] is again the temperature of the surface being cooled and [T.sub.a] the ambient temperature for thermal radiation. [ASHRAE 2009]
Accordingly, this research shows the relationship between the outdoor thermal environmental evaluation index for winter and the psychological response of the human body by using ETFe to temperature-convert the effect of air temperature and air velocity, long-wave thermal radiation in outdoor space, short-wave solar radiation, contact member's surface temperature, and humidity and arrange them on the same evaluation axis.
(d) Due to thermal radiation, the temperature inside the boundary layer decreases.
it is based on the laws of thermal convection and long wave thermal radiation. Thus, it can be stated that during the heating season internal heat gains are decreasing thermal energy flow required for heating the building in value of [[PHI].sub.in].
The observation that is fundamental to radiation heat transfer is that all objects emit thermal radiation that is proportional to the 4th power of the absolute temperature.
Thermal boundary layer increases as RJ(radiation) increases, due to the fact that the presence of thermal radiation causes thickening of the thermal boundary layer.
This shows that velocity decreases in the presence of high thermal radiation.
It is shown from this table that the local Nusselt number decreases with increasing the thermal radiation parameter R.