extremely high frequencies
11magnetron — /mag ni tron /, n. Electronics. a two element vacuum tube in which the flow of electrons is under the influence of an external magnetic field, used to generate extremely short radio waves. [1920 25; MAGNE(TO) + TRON] * * * ▪ electronics… …
12Dead Vent 7 — Studio album by Single Cell Orchestra Released 1995 Genre Ambient Label …
13tet|rode — «TEHT rohd», noun. a vacuum tube containing four elements, commonly a cathode, anode, and two grids: »Tetrodes…are able to operate at extremely high frequencies (William C. Vergara). ╂[< tetr + (electr)ode] …
14Ultrasound — High frequency sound waves. Ultrasound waves can be bounced off of tissues using special devices. The echoes are then converted into a picture called a sonogram. Ultrasound imaging, referred to as ultrasonography, allows physicians and patients… …
15spectroscopy — spectroscopist /spek tros keuh pist/, n. /spek tros keuh pee, spek treuh skoh pee/, n. the science that deals with the use of the spectroscope and with spectrum analysis. [1865 70; SPECTRO + SCOPY] * * * Branch of analysis devoted to identifying… …
16telecommunications media — Introduction equipment and systems metal wire, terrestrial and satellite radio, and optical fibre employed in the transmission of electromagnetic signals. Transmission media and the problem of signal degradation Every… …
17Nobel Prizes — ▪ 2009 Introduction Prize for Peace The 2008 Nobel Prize for Peace was awarded to Martti Ahtisaari, former president (1994–2000) of Finland, for his work over more than 30 years in settling international disputes, many involving ethnic,… …
18Valve amplifier — A valve amplifier or tube amplifier is a type of electronic amplifier that make use of vacuum tubes instead of solid state semiconductor devices (such as transistors). As any other electronic amplifier they serve to increase the power and/or… …
19sound — sound1 soundable, adj. /sownd/, n. 1. the sensation produced by stimulation of the organs of hearing by vibrations transmitted through the air or other medium. 2. mechanical vibrations transmitted through an elastic medium, traveling in air at a… …
20Sound — /sownd/, n. The, a strait between SW Sweden and Zealand, connecting the Kattegat and the Baltic. 87 mi. (140 km) long; 3 30 mi. (5 48 km) wide. Swedish and Danish, Oresund. * * * I Mechanical disturbance that propagates as a longitudinal wave… …
