mercury-arc tube
81Induction coil — An induction coil or spark coil (archaically known as a Ruhmkorff coil) is a type of disruptive discharge coil. It is a type of electrical transformer used to produce high voltage pulses from a low voltage DC supply. To create the flux changes… …
82Luminous efficacy — is a measure of how well a light source produces visible light. It is the ratio of luminous flux to power. Depending on context, the power can be either the radiant flux of the source s output, or it can be the total electric power consumed by… …
83Sulfur lamp — The sulfur lamp (also sulphur lamp) is a highly efficient full spectrum electrodeless lighting system whose light is generated by sulfur plasma that has been excited by microwave radiation. The technology was developed in the early 1990s, but,… …
84Lampe à décharge — Pour les articles homonymes, voir Lampe (homonymie). Lampe germicide à vapeur de mercure Une lampe à décharge est une …
85electromagnetic radiation — Physics. radiation consisting of electromagnetic waves, including radio waves, infrared, visible light, ultraviolet, x rays, and gamma rays. [1950 55] * * * Energy propagated through free space or through a material medium in the form of… …
86electromagnetism — /i lek troh mag ni tiz euhm/, n. 1. the phenomena associated with electric and magnetic fields and their interactions with each other and with electric charges and currents. 2. Also, electromagnetics. the science that deals with these phenomena.… …
87Invention of radio — Great Radio Controversy redirects here. For the album by the band Tesla, see The Great Radio Controversy. Contents 1 Physics of wireless signalling 2 Theory of electromagnetism …
88environment — environmental, adj. environmentally, adv. /en vuy reuhn meuhnt, vuy euhrn /, n. 1. the aggregate of surrounding things, conditions, or influences; surroundings; milieu. 2. Ecol. the air, water, minerals, organisms, and all other external factors… …
89Earth 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… …
90motion-picture technology — Introduction the means for the production and showing of motion pictures. It includes not only the motion picture camera and projector but also such technologies as those involved in recording sound, in editing both picture and sound, in… …
