earth-leakage protection
81Transformer types — Circuit symbols Transformer with two windings and iron core. Step down or step up transformer. The symbol shows which winding has more turns, but not usually the …
82Mobile phone radiation and health — A man speaking on a mobile telephone The effect of mobile phone radiation on human health is the subject of recent interest and study, as a result of the enormous increase in mobile phone usage throughout the world (as of June 2009 …
83Professional diving — Hardhat diving redirects here. Often, hardhat diving is used to specifically mean diving in the old type Standard diving dress. A US Navy diver at work. The umbilical supplying air from the surface is clearly visible Professional diving is a type …
84radiation measurement — ▪ technology Introduction technique for detecting the intensity and characteristics of ionizing radiation, such as alpha, beta, and gamma rays or neutrons, for the purpose of measurement. The term ionizing radiation refers to those… …
85Antioxidant — Model of the antioxidant metabolite glutathione. The yellow sphere is the redox active sulfur atom that provides antioxidant activity, while the red, blue, white, and dark grey spheres represent oxygen, nitrogen, hydrogen, and carbon atoms,… …
86Passive solar building design — Elements of passive solar design, shown in a direct gain application …
87Overhead power line — This article is about power lines for general transmission of electrical power. For overhead lines used to power road and rail vehicles, see Overhead lines. Transmission lines in Lund, Sweden …
88List of spaceflight-related accidents and incidents — Death in space redirects here. For death in specifically outer space conditions, see Space exposure. Space Shuttle Challenger disintegrates 73 seconds after launch, due to hot gases escaping the SRBs leading to structural failure of the external… …
89Cable — For other uses, see Cable (disambiguation). 6 inch (15 cm) outside diameter, oil cooled cables, traversing the Grand Coulee Dam throughout. An example of a heavy cable for power transmission …
90Ocean thermal energy conversion — Temperature differences between the surface and 1000m depth in the oceans Ocean Thermal Energy Conversion (OTEC) uses the difference between cooler deep and warmer shallow or surface ocean waters to run a heat engine and produce useful work,… …
