temperature coefficient of frequency
121Metal-halide lamp — A metal halide gas discharge lighting system provides illumination for a college baseball game at Olsen Field in College Station, Texas, United States. Note the various colors of the lights as they warm up. Metal halide lamps, a member of the… …
122LIDAR — A FASOR used at the Starfire Optical Range for LIDAR and laser guide star experiments is tuned to the sodium D2a line and used to excite sodium atoms in the upper atmosphere …
123Field emission — (FE) is the emission of electrons from the surface of a condensed phase into another phase due to the presence of high electric fields. In this phenomenon, electrons with energies below the Fermi level tunnel through the potential barrier at the… …
124Energy harvesting — (also known as Power harvesting or energy scavenging ) is the process by which energy is captured and stored. Frequently this term is applied when speaking about small autonomous devices, like those used in sensor networks. A variety of different …
125Piezoelectric sensor — A piezoelectric sensor is a device that uses the piezoelectric effect to measure pressure, acceleration, strain or force by converting them to an electrical signal.ApplicationsPiezoelectric sensors have proven to be versatile tools for the… …
126Opacity (optics) — Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric,… …
127Heat — In physics, heat, symbolized by Q , is energy transferred from one body or system to another due to a difference in temperature. [cite book|author= Daintith, John |title=Oxford Dictionary of Physics|publisher=Oxford University… …
128clock — clock1 /klok/, n. 1. an instrument for measuring and recording time, esp. by mechanical means, usually with hands or changing numbers to indicate the hour and minute: not designed to be worn or carried about. 2. See time clock. 3. a meter or… …
