sound-energy-flux density
21electromagnet — /i lek troh mag nit/, n. a device consisting of an iron or steel core that is magnetized by electric current in a coil that surrounds it. [1815 25; ELECTRO + MAGNET] * * * Device consisting of a core of magnetic material such as iron, surrounded… …
22electron tube — an electronic device that consists, typically, of a sealed glass bulb containing two or more electrodes: used to generate, amplify, and rectify electric oscillations and alternating currents. Also called electronic tube. Cf. gas tube, vacuum tube …
23Hydraulic analogy — The electronic–hydraulic analogy (derisively referred to as the drain pipe theory by Oliver Heaviside) is the most widely used analogy for electron fluid in a metal conductor. Since electric current is invisible and the processes at play in… …
24Nikola Tesla — Tesla, aged 37, 1893, photo by Sar …
25Intensity (physics) — In physics, intensity is a measure of the time averaged energy flux. The word intensity here is not synonymous with , , or , as it sometimes is in colloquial speech. For example, the intensity of pressure is meaningless, since the parameters of… …
26Ferroresonance — The phenomenon of Ferroresonance is the occurrence of an unstable high voltage, typically on 3 phase electrical systems which only occurs under specific conditions. The nature of the overvoltage can cause the failure of equipment.Ferroresonance… …
27Orders of magnitude (magnetic field) — This page lists examples of magnetic field B in teslas produced by various different sources. They are grouped by orders of magnitude, and each section covers three orders of magnitude, or a factor of one thousand. Note: Traditionally,… …
28Preclinical imaging — is the visualization of animals for research purposes, such as drug development. Imaging modalities have long been crucial to the researcher in observing changes, either at the organ, tissue, cell, or molecular level, in animals responding to… …
29Sunspot — A sunspot is a region on the Sun s surface (photosphere) that is marked by intense magnetic activity, which inhibits convection, forming areas of reduced surface temperature. They can be visible from Earth without the aid of a telescope. Although …
30Non-line-of-sight propagation — Non line of sight (NLOS) or near line of sight is a term used to describe radio transmission across a path that is partially obstructed, usually by a physical object in the innermost Fresnel zone. Many types of radio transmissions depend, to… …
