Barrow's zones
Barrow's zones The original subdivision by George Barrow (1853–1932) of the sequence of mineral changes seen in rocks of pelitic composition in the Glen Esk region of north-eastern Scotland. Each zone is bounded by two
isograds, each of which marks the appearance, in the direction of increasing
metamorphic grade, of a new
index mineral, and is named after the index mineral seen on the lower-grade boundary. (For instance, the kyanite zone has the kyanite isograd as its low-grade boundary and the sillimanite isograd as its high-grade boundary.) Within each zone, no additional minerals appear in the
pelites, the constant mineral assemblage representing equilibrium over a range of metamorphic conditions. See
BARROVIAN-TYPE METAMORPHISM. Compare
BUCHAN METAMORPHIC ZONES.
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YTTERBIUM GAINS GROUND IN QUEST FOR NEXT-GENERATION ATOMIC CLOCKS
News Wire article from: US Fed News Service, Including US State News; 8/13/2009; 700+ words
; ...An experimental atomic clock based on ytterbium atoms is about four times more accurate...by measuring the natural frequency of ytterbium, carefully accounting for all possible...were good enough to indicate that the ytterbium clock is competitive in some respects...
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Atomic clock based on ytterbium atoms 4 times more accurate than before
News Wire article from: The Hindustan Times; 8/12/2009; 603 words
; ...an experimental atomic clock based on ytterbium atoms is about four times more accurate...by measuring the natural frequency of ytterbium, carefully accounting for all possible...were good enough to indicate that the ytterbium clock is competitive in some respects...
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Atomic clock based on ytterbium atoms 4 times more accurate than before.
News Wire article from: Asian News International; 8/12/2009; 700+ words
; ...an experimental atomic clock based on ytterbium atoms is about four times more accurate...by measuring the natural frequency of ytterbium, carefully accounting for all possible...were good enough to indicate that the ytterbium clock is competitive in some respects...
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Ytterbium perfluorooctanesulfonate catalyzed synthesis of acylals from aldehydes and acetic anhydride in a fluorous biphasic system.
Magazine article from: Canadian Journal of Chemistry; 11/1/2006; ; 700+ words
; Abstract: Ytterbium perfluorooctanesulfonate [[Yb(OPf...catalytic activity. Key words: acylals, ytterbium perfluorooctanesulfonate, fluorous...Resume : Le perfluorooctanesulfonate d'ytterbium [[Yb(OPf).sub.3]] catalyse...
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Optical properties of PMMA doped with erbium(III) and ytterbium(III) complexes.(polymethylmethacrylate)(Report)
Magazine article from: Polymer Engineering and Science; 9/1/2009; ; 700+ words
; ...in the three-level system. Erbium-ytterbium co-doping of EDFAs has been proposed...heptanedionate) (Sigma-Aldrich) and the ytterbium(III) tris(2,2,6,6-tetramethyl...0 at% erbium were co-doped with ytterbium in amounts also ranging from 1.0 to...
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IPG Photonics Extends Ytterbium Pulsed Fiber Laser Offerings
Newspaper article from: Wireless News; 6/20/2007; 700+ words
; ...06-20-2007 IPG Photonics Extends Ytterbium Pulsed Fiber Laser Offerings WIRELESS...June 20, 2007-IPG Photonics Extends Ytterbium Pulsed Fiber Laser Offerings (C)2007...announced a major expansion of its Ytterbium pulsed fiber laser product line, including...
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StockerYale Debuts Double-Clad Ytterbium Fiber for the Fiber Laser Market
Newspaper article from: Wireless News; 9/11/2005; 392 words
; ...2005 StockerYale Debuts Double-Clad Ytterbium Fiber for the Fiber Laser Market WIRELESS...2005-StockerYale Debuts Double-Clad Ytterbium Fiber for the Fiber Laser Market (C...availability of the first in a series of ytterbium (Yb) doped fiber products. The fiber...
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Publication No. WO/2009/099121 Published on Aug. 13, Assigned to Nippon Mining & Metals for Ytterbium Sputtering Target, Target Manufacturing Method (Japanese Inventor)
News Wire article from: US Fed News Service, Including US State News; 8/18/2009; 398 words
; ...Shiro Tsukamoto, Japan, has developed a ytterbium sputtering target and method for manufacturing...explains a "method for manufacturing an ytterbium sputtering target. In the method, an ytterbium target material having a surface vickers...
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California Inventors Develop Ytterbium-Barium Silicate Radiopaque Glasses
News Wire article from: US Fed News Service, Including US State News; 2/20/2007; 453 words
; ...Rebecca K. Santiago of Santa Maria, Calif., have developed ytterbium-barium silicate radiopaque glasses. According to the U...radiopaque glasses comprising silicon dioxide (15 30%), ytterbium oxide (5 35%), barium oxide (30 50%) and fluoride...
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EXPERIMENTAL ATOMIC CLOCK USES YTTERBIUM 'PANCAKES'
News Wire article from: US Fed News Service, Including US State News; 3/6/2006; 700+ words
; ...lattice made of intersecting laser beams. The design, in which ytterbium atoms oscillate or "tick" at optical frequencies, has the...single line, each containing about 10 atoms of the heavy metal ytterbium. The lattice design results in fewer systematic errors than...
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Ytterbium (revised)
Book article from: Chemical Elements: From Carbon to Krypton
YTTERBIUM (REVISED) Note: This article, originally...2006 for the eBook edition. Overview Ytterbium belongs to the lanthanide family. The...separation can be done much more easily. Ytterbium was one of nine new elements discovered...
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Ytterbium
Book article from: Chemistry: Foundations and Applications
Ytterbium melting point: 824°C boiling...g/cm 3most common ions: Yb(III) Ytterbium was discovered by the Swiss chemist Jean...earth orthophosphates. In the earth, ytterbium is more abundant than tin. Ytterbium...
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ytterbium
Book article from: The Columbia Encyclopedia, Sixth Edition
ytterbium [for Ytterby, a town in Sweden...about 7.0; valence +2 or +3. Ytterbium is a soft, malleable, ductile, lustrous...substance contained lutetium in addition to ytterbium. At about this same time C. A. von...
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Periodic Table of the Elements: Ytterbium
Book article from: The Columbia Encyclopedia, Sixth Edition
Periodic Table of the Elements: Ytterbium Periodic Table of the Elements: Ytterbium Atomic Number: 70 Atomic Symbol: Yb Ytterbium Atomic Weight: 173.04 Electron Configuration: 2 · 8 ·...
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Lutetium (revised)
Book article from: Chemical Elements: From Carbon to Krypton
...discovery of a new element in yttria. He called the element ytterbium. Other chemists suspected that ytterbium was really a mixture of elements. They searched for ways to separate ytterbium into simpler parts. It took nearly thirty years to solve...
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