Inner core crystallization

In summary, there are two models of inner core crystallization one involving early and rapid... 

The W-Hf isotope system constrains the age of core-mantle differentiation to within the first 30 Ma years of Earth s history (Kleine et al., 2002 Yin et al., 2002). However, the age of inner core crystallization is not resolved. 

Initiation of inner-core crystallization and growth, and start-up of core dynamo remnant magnetism in c.2.9Ca rocks... 

A comment regarding the dispersion of the Ru-Rh/Si02 and the Ru-Ir/Si02 is in order. For the case of the supported Pt-Ru catalysts. Increases in dispersion as a result of clustering were very large ( ). This effect was particularly noticeable for bimetallic particles which conform to the cherry model. Evidently, the formation of an inner core enriched in one of the two metals, followed by an outer layer enriched in the other metal, inhibits further crystal growth. For the alumina-supported Pt-Ru bimetallic clusters, the effect, although present, is considerably smaller. 

Oligomers of perfluorohexyl-ethene fulfilled these expectations in all preclinical studies, in vitro tests as well in animal tests. A radical polymerisation, followed by ultra-purification steps, created a crystal clear gel-like substance. The behaviours of the mixture of dimeric, trimeric and tetrameric star-shaped species with an inner core of hydrocarbon bonds and an outer layer of perfluoro-alkyl chains could be adjusted by the ratio of the dimeric, trimeric and tetrameric species, using a thin layer distillation. In dependence on this ratio, the viscosity could be adjusted in the range between 90 mPas and 1700 mPas, the specific density between 1.60 g/ml and 1.66 g/ml and the interfacial tension against water between... 

The charge transfer spectrum below 50,000 cm.-1 is due to the promotion of an electron from the oxygen tt orbital (ej) to the crystal field levels ba and e,. Denoting the inner core [Pg.231]

In the X-X method, the same result is obtained as in the X-N procedure by making use of the fact that the high 28 X-ray intensities measured with short wavelengths, i.e., AgKa = 0.560 A, are determined only by the inner core, Is, electrons for first row elements. This method has the obvious advantage that all measurements are made on the same crystal. The tuneable wavelength property of synchrotron X-rays is useful for this type of experiment. 

Seismological evidence has led to the realization that the Earth is a layered body, with the basic subdivisions into crust, mantle, and core being further refined to give an upper and lower mantle separated by a transition zone, and a liquid outer core and solid inner core. The different layers show fairly sharp contrasts in density and elastic properties, leading to speculation that changes in crystal structure (and possibly in electronic structure) as well as in overall composition are responsible for the layer-... 

THE INNER CORE, ITS CRYSTALLIZATION, AND CORE-MANTLE EXCHANGE... 

The solid inner core represents only —5% of the core s mass and —4% of its volume. Geophysical models of the inner core have identified its structure, elastic properties, and modeled its crystallization history. This, without question, is the most remote region of the planet... 

Obviously, crystallization of pure titaniosilicate zeolite Beta without Al could then be possible if the nucleation problem was solved. We have done this by seeding with highly active zeolite Beta seeds comprised of very small zeolite Beta crystals (typically —0.05 mm and below) showing good stability in the synthesis media (TEOS/Seed method) (ref. 12). In this way it is possible to synthesize highly crystalline zeolite Ti-Beta with Si/Al ratios well above those obtained by other synthesis procedures, for example Si/Al ratios about 1000. Additionally, as shown by XPS, the crystals obtained by this procedure consist of an inner core of... 

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