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The two forms of diathermy employed in physical medicine and rehabilitation are short wave and microwave. [4] [5] [6] The application of moderate heat by diathermy increases blood flow and speeds up metabolism and the rate of ion diffusion across cellular membranes. The fibrous tissues in tendons, joint capsules, and scars are more easily ...
A microwave oven uses dielectric heating to cook food.. Dielectric heating, also known as electronic heating, radio frequency heating, and high-frequency heating, is the process in which a radio frequency (RF) alternating electric field, or radio wave or microwave electromagnetic radiation heats a dielectric material.
Diathermy equipment typically operates in the short-wave radio frequency (range 1–100 MHz) or microwave energy (range 434–915 MHz). [citation needed] Pulsed electromagnetic field therapy (PEMF) is a medical treatment that purportedly helps to heal bone tissue reported in a recent NASA study. This method usually employs electromagnetic ...
Shortwave bands are frequency allocations for use within the shortwave radio spectrum (the upper medium frequency [MF] band and all of the high frequency [HF] band). Radio waves in these frequency ranges can be used for very long distance (transcontinental) communication because they can reflect off layers of charged particles in the ionosphere and return to Earth beyond the horizon, a ...
A word was needed to distinguish these new shorter wavelengths, which had previously been lumped into the "short wave" band, which meant all waves shorter than 200 meters. The terms quasi-optical waves and ultrashort waves were used briefly [37] but did not catch on. The first usage of the word micro-wave apparently occurred in 1931. [39] [40]
A block diagram is a diagram of a system in which the principal parts or functions are represented by blocks connected by lines that show the relationships of the blocks. [1] They are heavily used in engineering in hardware design , electronic design , software design , and process flow diagrams .
Sometimes, when the carrier pulses are strong enough to block out the normal static atmospheric "hiss" in the receiver, CW signals could be heard without a BFO as "pulses" of silence. However this was not a reliable method of reception. In order to make the carrier pulses audible in the receiver, a beat frequency oscillator is used.
Spectral intensity of sunlight (average at top of atmosphere) and thermal radiation emitted by Earth's surface. Shortwave radiation (SW) is thermal radiation in the optical spectrum, including visible (VIS), near-ultraviolet (UV), and near-infrared (NIR) spectra.