and more stable clock, the Ytterbium lattice optical clock, has proven to be a hundred times more accurate and as such, it has the capability and is regarded as certain of redefining the SI second. Ytterbium was discovered by Jean Charles Galissard de Marignac, a Swiss chemist, in 1878 in Geneva Switerland. Named after Yterrby, a village in Sweden, it is one of nine elements discovered in the mineral yttria and one of four elements (yttrium, terbium, erbium, ytterbium) named after this town. Although
Rare earth elements allow for the conveniences shared by modern society. It is the critical components that have made the advancements in technology possible. Its versatility expands thought different media that include: renewable energy, geographic information systems, national security, missile guidance, computer technology, hybrid vehicles, plastics, medical technology and more. All population throughout the world use it regardless if they know it or not. The mining and process of rare earths
Jaden Gaddis Avila Chemistry 8 November 2015 Ytterbium Ytterbium is a rare element that has just recently be found. Marignac discovered it in 1850 in Ytterby, a small village in Sweden. There was noting really know about Ytterbium until the 1950s because the element was not in a very pure form; in fact when it was first found with the monazite sand, which only contains about 0.03% Ytterbium. Ytterbium is a very weird element, the metal changes with different pressures. When the metal is at its
Yttrium is element 39 on the periodic table. Its atomic mass is 88.9059 and the complete electron configuration is 2-8-18-9-2. Although it is a transition metal, located in group 3 on the periodic table, it forms only one ion, with a +3 charge. Yttrium was discovered by Johan Gadolin in 1789 and is an iron gray color. In 1787, Carl Axel Arrhenius, who was an army lieutenant as well as a part-time chemist, found a heavy black rock near Ytterby, which is located in Sweden. He thought it had tungsten
2.3 LASER ASSISTED MILLING Laser assisted machining is a manufacturing process that has been investigated as an alternative to conventional machining of hard and/or difficult to process materials [45]. Laser assisted machining involves pre heating of a focused area with a laser beam (often c.w. laser) over the surface of the workpiece to cause localized heating and thermal softening along the path of the cutting action. The main advantage that laser assisted machining gas over conventional machining
Chlorine is a greenish yellow gas which combines directly with nearly all elements. Chlorine is a respiratory irritant. The gas irritates the mucous membranes and the liquid burns the skin. As little as 3.5 ppm can be detected as an odour, and 1000 ppm is likely to be fatal after a few deep breaths. It was used as a war gas in 1915. It is not found in a free state in nature, but is found commonly as NaCl (solid or seawater). Table: basic information about and classifications of chlorine. • Name:
2.1. History, Working Principles and Types of 3D printing 2.1.1. History of 3D Printers The conference organizers Alberto Corsín Jiménez and Adolfo Estalella state at the beginning of their invitation: “prototypes have acquired certain prominence and visibility in recent times”. (The long history of prototypes, Micheal Guggenheim,2006) In 1920s, prototyping is become very important issue in developing manufacturing technology. Paper scales, wooden or clay models are used for describe inventors ideas
2.6.2.2 Waveguide Dispersion The effective index varies with wavelength not only due to of material dispersion, but also because varies with . In turn, it varies with wavelengths. These implicit variations of [ ] with gives rise to the second cause for chromatic dispersion, which is term waveguide dispersive [D37]. The total dispersive are combinations of the relative contributions of waveguide dispersion and material dispersion for a conventional single-mode fibers. The zero-dispersive