close frequency signals
81Coordinated Universal Time — UTC redirects here. For other uses, see UTC (disambiguation). Coordinated Universal Time (abbreviated UTC) is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich… …
82Burglar alarm — Silent alarm redirects here. For the album, see Silent Alarm (album). Burglar (or intrusion), fire and safety alarms are all electronic today. Sensors are connected to a control unit via a low voltage hardwire or narrowband RF signal which is… …
83chemoreception — chemoreceptive /kee moh ri sep tiv, kem oh /, adj. /kee moh ri sep sheuhn, kem oh /, n. the physiological response to chemical stimuli. [1915 20; CHEMO + RECEPTION] * * * Sensory process by which organisms respond to external chemical stimuli, by …
84Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
85Action potential — In physiology, an action potential is a short lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called… …
86particle accelerator — accelerator (def. 7). [1945 50] * * * Device that accelerates a beam of fast moving, electrically charged atoms (ions) or subatomic particles. Accelerators are used to study the structure of atomic nuclei (see atom) and the nature of subatomic… …
87endocrine system, human — ▪ anatomy Introduction group of ductless glands (gland) that regulate body processes by secreting chemical substances called hormones (hormone). Hormones act on nearby tissues or are carried in the bloodstream to act on specific target organs… …
88Operational amplifier — A Signetics μa741 operational amplifier, one of the most successful op amps. An operational amplifier ( op amp ) is a DC coupled high gain electronic voltage amplifier with a differential input and, usually, a single ended output.[1] An op amp… …
89Cassini–Huygens — Artist s concept of Cassini s Saturn Orbit Insertion Operator NASA / ESA / ASI Mission type …
90Citizens' band radio — Typical 1980s CB base station, used with outdoor antenna. This radio may also be used in an automobile, since it is powered by 13.8V DC. Shown with Astatic Power D 104 desk mic …
