periodic reversal
1Periodic current reversal — (PCR) is a current modulation technique that can be used in various electrochemical processes.In the most basic sense PCR simply means that the electrical current applied to the cell is reversed periodically but unlike pure AC the average (nett)… …
2Geomagnetic reversal — Magnetic reversal redirects here. For switching of a magnet, see Magnetization reversal. Geomagnetic polarity during the late Cenozoic Era. Dark areas denote periods where the polarity matches today s polarity, light areas denote periods where… …
3Atlantic Ocean — an ocean bounded by North America and South America in the Western Hemisphere and by Europe and Africa in the Eastern Hemisphere. ab. 31,530,000 sq. mi. (81,663,000 sq. km); with connecting seas ab. 41,000,000 sq. mi. (106,100,000 sq. km);… …
4Pole shift hypothesis — Polar Shift redirects here. For the Clive Cussler novel, see Polar Shift (novel). For the Antarctica benefit compilation, see Polar Shift (album). This article is about the hypothesis of pole shift in its historical context. For a description of… …
5AC power — This article deals with power in AC systems. See Mains electricity for information on utility supplied AC power. Usually hidden from the unaided eye, the blinking of (non incandescent) lighting powered by AC mains is revealed in this motion… …
6el Nino — a periodic reversal in the usual pressure, wind and precipitation patterns of the tropical Pacific region which can have severe implications for human activity. Excellent background and explanations here:… …
7Negative index metamaterials — A negative index metamaterial causes light to refract, or bend, differently than in more common positive refractive index materials. Negative index metamaterials or negative index materials (NIM) are artificial structures where the refractive… …
8climate — /kluy mit/, n. 1. the composite or generally prevailing weather conditions of a region, as temperature, air pressure, humidity, precipitation, sunshine, cloudiness, and winds, throughout the year, averaged over a series of years. 2. a region or… …
9Superlens — A superlens, super lens or perfect lens is a lens which uses metamaterials to go beyond the diffraction limit. The diffraction limit is an inherent limitation in conventional optical devices or lenses.[1] In 2000, a type of lens was proposed,… …
10Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
