Mass transfer isotopic

Shikazono, N., Yonekawa, N. and Karakizawa, T. (2002) Mass transfer, oxygen isotope, and gold precipitation in epithermal gold system A case study of the Hishikari deposit, southern Kyushu Japan. Resource Geology, 52, 211-222. 

Wemer M, Mikolajewicz U, Hoffmann G, Heimann M (2000) Possible changes of in precipitation caused by a meltwater event in the North Atlantic. J Geophys Res 10 10161-10167 Whitehead NE, Ditchbmn RG, Wilhams PW, McCabe WJ (1999) Pa and contamination at zero age a possible hmitation on U/Th series dating of speleothem material. Chem Geol 156 359-366 Wigley TML, Plummer LN, Pearson FJ (1978) Mass transfer and carbon isotope evolntion in natural water systems. Geochim Cosmochim Acta 42 1117-1140... 

Primary outputs are produced essentially by sedimentation and (to a much lower extent) by emissions in the atmosphere. The steady state models proposed for seawater are essentially of two types box models and tube models. In box models, oceans are visualized as neighboring interconnected boxes. Mass transfer between these boxes depends on the mean residence time in each box. The difference between mean residence times in two neighboring boxes determines the rate of flux of matter from one to the other. The box model is particularly efficient when the time of residence is derived through the chronological properties of first-order decay reactions in radiogenic isotopes. For instance, figure 8.39 shows the box model of Broecker et al. (1961), based on The ratio, normal-... 

Mechanistic studies start with determination of the kinetic rate law and the rate-limiting step information on heat and mass transfer is also needed. These studies may use such techniques as isotopic labeling, chemisorption measurements, surface spectroscopy, temperature-programmed desorption, and kinetic modeling experiments. 

A distinct class of models that describe the chemical evolution of the Earth are the so-called box models, in which assumptions are made about the geometry of distinct reservoirs and their interactions. For example, one can assign four distinct reservoirs in the upper mantle, lower mantle, continental crust, and atmosphere and develop differential equations that incorporate radiogenic ingrowth, chemical fractionation effects, and assumptions about mass transfer between the reservoirs. Successful models reproduce the observed isotopic ratios and/or... 

Major element mass transfer can be coupled to isotopic shifts that allow the fluid source to be traced. Tracy et al. (1983) found extreme metasomatism, including the loss of nearly all potassium and sodium, for metacarbonate rock adjacent to a quartz vein in the Wepawaug Schist. The infiltrating fluid had lower Xqo than fluid... 

Van Haren J. L. M., Ague J. J., and Rye D. M. (1996) Oxygen isotope record of fluid infiltration and mass transfer during regional metamorphism of pelitic schist, Connecticut, USA. Geochim. Cosmochim. Acta 60, 3487-3504. 

A set of five programs known as The Geochemist s Workbench or GWB was developed by Bethke (1994) with a wide range of capabilities similar to EQ3/6 and PHREEQC v. 2. GWB performs speciation, mass transfer, reaction-path calculations, isotopic calculations, temperamre dependence for 0-300 °C, independent redox calculations, and sorption calculations. Several electrolyte databases are available including ion association with Debye-Huckel activity coefficients, the Pitzer formulation, the Harvie-M0ller-Weare formulation, and a... 

Merlivat L. and Coantic M. (1975) Study of mass transfer at the air-water interface by an isotopic method. J. Geophys. Res. 80, 3455-3464. 

Wigley T. M. L., Plummer L. N., and Pearson F. J. (1978) Mass transfer and carbon isotope evolution in natural water systems. Geochim. Cosmochim. Acta 42, 1117-1139. 

Systemic bioavailability is the product of fraction of dose absorbed (/a), fraction of dose escaping gut metabolism (/g), and fraction of dose escaping first-pass metabolism (F ). Permeability class is based upon /a, which may be estimated either in vivo or in vitro by direct measurement of mass transfer across human intestinal epithelium. In vivo methods include (i) mass balance studies using unlabeled, stable-isotope labeled, or a radiolabeled drug substance (ii) oral bioavailability using a reference intravenous dose or (iii) intestinal perfusion studies either in humans or an acceptable animal model. Suitable in vitro methods involve the use of either excised human/animal intestinal tissues or cultured epithelial monolayers. All of these methods are deemed appropriate for drugs whose absorption is controlled by passive mechanisms. 

Most stars appear to be members of binary or multiple systems. The fraction of massive stars being members of close binaries — i.e. such in which mass overflow is expected to occur — is estimated to be of the order of 20. .. 40% (cf. Garmany et al. 1980, Podsiadlowski 1997, Mason et al. 1998). Thus, it appears necessary to investigate the effect of binary mass transfer on the overall massive star nucleosynthesis yields if the mass transfer would increase the yield of an isotope only by a factor of 3, then massive close binaries might be the dominant source of this isotope. Clearly, most isotopes are not affected by binaries at this level (cf. De Donder Vanbeveren 2002). 

Yoshida, H. Kataoka, T. Ikeda, S. Intraparticle mass transfer in bidispersed porous ion exchanger, part I. Isotopic ion exchange. Can. J. Chem. Eng. 1985, 62, 422. 

Purposes Used to define net masses of minerals (or gases) dissolved and/or precipitated along a flow path between two wells. Also considers ion exchange and other user-definable mass transfer processes. Can account for the mixing of two waters to produce a third, final water. NETPATH can also be used to age-date groundwaters (using C) and can solve isotope evolution problems. 

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