AFC processes

Since an isotope ratio cannot be fractionated by crystal-liquid equilibria and therefore is indicative of the magmatic source, the correlation between an isotope ratio and a major or trace element can be used as a guide to the major element or trace element composition of the source. Typically, ratios of highly incompatible trace elemente (Section 4.7.1 and Table 6.7) are most usehil in characterizing the 

The equations of Langmuir et al. (1978) predict that data plotted on an isotope 

The ultimate result of defining cnist and mande isotopic reservoirs must be a model which explains how the reisenfoirs interact and how they obtained their present-day 

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Pa Cpncentration of a trace element In the wallrock being assimilated during AFC processes ... 

F Weight fraction of melt produced In partial melting in fractional crystallization, the fraction of melt remaining f Fraction of melt allocated to the solidification zone in in situ crystallization which is returned to the magma chamber f A function of F, the fraction of melt remaining In AFC processes... 

Incompatible element concentrations also vary during fractional crystalluadon, although the effect is most strongly marked in AFC processes. 

More recent examples include Ampac Fine Chemicals (AFC) in California, who implemented a multipurpose continuous small-scale plant for the production of several hundred tons of API per year [31], and Sigma-Aldrich s Fine Chemicals, which has been adding continuous-process technology within its Buch facility [32]. 

Compagnie AFC A variation of the Hall-Heroult process for making aluminum metal, in which the electrolyte is a mixture of aluminum fluoride, sodium fluoride, and barium chloride. The process is operated at a lower temperature than the Hall-Heroult process, and the product has a purity of 99.99 percent instead of 99.5 percent. Developed in 1934 by the Cie. des Produits Chimiques et Electrometallurgiques Alais, Froges et Carmarque, in France, and still operated by that company. 

EFSA (2005) Opinion of the Scientific Panel on food additives, flavourings, processing aids and materials in contact with food (AFC). European Food Safety Authority, http //www.efsa. europa.eu/EFSA/ScientiflcPanels/efsa locale-l 178620753812 AFC.htm... 

Dawson Range s dykes are a calc-alkaline suite that may have evolved through AFC and mixing processes, giving rise to a few samples that only partially fit the adakitic criteria ... 

During fractional crystallization, the country rocks may assimilate the crystallizing magmas (DePaolo, 1981 O Hara, 1998). This process is called assimilation-fractional crystallization (AFC) (DePaolo, 1981). The conservation of mass for a trace element requires... 

Spera, F.J. and Bohrson, W.A., 2001. Energy-constrained open-system magmatic processes I general model and energy-constrained assimilation and fractional crystallization (EC-AFC) formulation. J. Petrol., 42 999-1018. 

Gaseous cyclobutene isomerizes to butadiene in a first-order process which has afc-value at 153°C of 3.3 x 10-4 s-1. How many minutes would it take for the isomerization to proceed 40% to completion at this temperature ... 

An AFC combined with a lead acid battery has been used in a hybrid vehicle. Between operating times the cell was shut down by using the battery to drain the KOH electrolyte. This technique can improve the life expectancy enormously by protecting the fuel cell from a high open circuit voltage, which otherwise could induce carbon oxidation processes to produce carbonates that would destroy the matrix electrolyte. 

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