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This alchemical symbol for platinum was made by joining the symbols of silver and gold . Antonio de Ulloa is credited in European history with the discovery of platinum. In 1735, Antonio de Ulloa and Jorge Juan y Santacilia saw Native Americans mining platinum while the Spaniards were travelling through Colombia and Peru for eight years. Ulloa ...
The first Light-Emitting Diode was created in 1927 by Russian inventor Oleg Losev, [1] and used silicon carbide as a semiconductor. However, electroluminescence as a phenomenon was discovered twenty years earlier by the English experimenter Henry Joseph Round of Marconi Labs , using the same crystal and a cat's-whisker detector .
1962 Nick Holonyak Jr. develops the first practical visible-spectrum (red) light-emitting diode. 1963 Kurt Schmidt invents the first high pressure sodium-vapor lamp. [18] 1972 M. George Craford invents the first yellow light-emitting diode. 1972 Herbert Paul Maruska and Jacques Pankove create the first violet light-emitting diode.
As illustrated by a straight line on the chromaticity diagram, simple two-white blends will have a pink bias, becoming most severe in the middle. A small amount of green light, provided by another LED, could correct the problem. [38] Some products are RGBWW, i.e. RGBW with tunable white. [39] A final class of white LED with mixed light is dim ...
William Willis Jr. (1841–1923) [1] is a British inventor who developed the platinum printing process, an early form of photography, based on the light sensitivity of platinum salts, originally discovered by John Herschel. [2] William Willis was the son of British engraver of landscapes, and inventor of the anilin printing, process William Willis.
The 70th anniversary of any important event can be referred to as a platinum jubilee, although this term is seldom used. Music. a platinum album is an album whose sales figures have reached a certain amount. This threshold differs from market to market—in the United States, a platinum album is one that has sold at least 1,000,000 copies.
In 1802, Humphry Davy had what was then the most powerful electrical battery in the world at the Royal Institution. With it, Davy created the first incandescent light by passing electric current through a thin strip of platinum, chosen because the metal had an extremely high melting point. It was neither sufficiently bright nor long lasting ...
The materials used for the LED have a direct band gap with energies corresponding to near-infrared, visible, or near-ultraviolet light. LED development began with infrared and red devices made with gallium arsenide. Advances in materials science have enabled making devices with ever-shorter wavelengths, emitting light in a variety of colors.