Untersuchungen zur Frage des Diureserhythmus beim Kind

Johannsen, Liselott; Rodeck, H

doi:10.1007/bf00438632

Cited by 4 publications

(7 citation statements)

References 32 publications

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“…The entries of silicate melts (Endell and Zauleck, 1950;Johannsen and Brunion, 1959;and Rtintgen et al , 1960) . In addition to the lack of experimental data on the influence of Fe^O-, it must also be realized *.tv*t tUo actual.…”

Section: Viscosity Calculationsmentioning

confidence: 99%

The viscosity of magmatic silicate liquids; a model calculation

Bottinga¹,

Weill²

1972

American Journal of Science

700

257

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INTRODUCTIONThere are very few aspects of igneous petrology which are not in some way closely related to the viscosity of magma. Rate of crystal growth, gravitative settling or rise of solids and bubbles, mode of volcanic eruption, flow differentiation mechanisms, flow characteristics of lavas, mass transfer in magmas under externally imposed pressure gradients or natural convection, rate of cooling of magmatic intrusions and lavas; all of these phenomena are critically dependent upon the viscosity of magmatic liquid or the effective viscosity of a magmatic suspension.Quantitative evaluation of any of the above igneous processes must begin with a knowledge of the viscosity of silicate liquids within the rather wide range of temperature and composition displayed by natural me^ts. The need for such viscosity data has long been recognized by petrologists, and many attempts have been made to determine effective viscosities from field observations of lava flow rates (Becker, 1897; Palmer, 1927; Nichols, 1939;Krauskopf, 1948; Hinakami, 1951; Walker, 1967, among others). Uncertainties related to temperature measurements; size, shape, and roughness of the flow channel; and gas and solid particle content make evaluation of such viscosity determinations very difficult. .Laboratory viscosity measurements on geologically significant liquids date back to the turn of the century. The first determinations were probably made by Doelter (1902), who was able to classify on a qualitative scale the viscosities of various rocks and minerals melted in the laboratory. Much of the early work is summarized by Kittl (1913).The measurements of Kani (1934aKani ( , 1934bKani ( , 1935, Kozu and Kani (1935), Kani and Hosakawa (1936), Volarovich (1936), and Volarovich and Tolstoi (1936) were valuable contributions towards an understanding of the temperature and composition dependence of silicate viscosity. Bowen (1934) measured the viscosities of molten orthoclase and albite, and included an interesting discussion of the significance of viscosity in petrology and liquid silicate experimental work. More recently, viscosity measurements on molten rocks have been reported by Euler and Winkler (1957), Shaw (1969), Carron (1969), and Murase and McBirney (1970).Newton's law of viscosity states that the shear stress in liquids undergoing laminar flow is proportional to the local velocity gradient perpendicular to the stress. The proportionality constant in this relation is known as the viscosity coefficient, n. In Newtonian fluids it is independent of the magnitude of the shear stress. The silicate liquids discussed in this paper closely approximate the Newtonian model. Fluid suspensions of solids or bubbles are best described by non-Newtonian models. For a discussion of this problem in geological context the reader is referred to Shaw et al. (1968) and Shaw (1969). 3.The viscosities of silicate liquids are strongly dependent upon chemical composition. . For example, at 1300 C where most igneous rocks are completely melted, the composition range ...

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Section: Viscosity Calculationsmentioning

confidence: 99%

The viscosity of magmatic silicate liquids; a model calculation

Bottinga¹,

Weill²

1972

American Journal of Science

700

257

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“…Many experimental researches have been performed on this system. [1][2][3][4][5][6][7][8] However, most parts of the work were focused on the effect of CaO/Al2O3 ratio on viscosity, while study on the influence of Al2O3/SiO2 ratio is very lack. The main objective of this investigation is to measure and model the viscosity variation behavior of CaO-Al2O3-SiO2 melt with Al2O3/SiO2 ratio.…”

Section: Introductionmentioning

confidence: 99%

Influence of Al2O3/SiO2 Ratio on Viscosities of CaO^|^ndash;Al2O3^|^ndash;SiO2 Melt

Zhang

Chou

2013

ISIJ Int.

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The influence of Al2O3/SiO2 ratio on viscosity of CaO-Al2O3-SiO2 melt was investigated by the rotating cylinder method in this study. Three groups of compositions with different CaO contents of 0.35, 0.4 and 0.45 were studied. From the experimental results, it was concluded that viscosity always first increases and then decreases as gradually increasing Al2O3/SiO2 ratio. The appearance of viscosity maximum may be resulted from the opposite variation tendencies of mean bond strength and the degree of polymerization of melt with Al2O3/SiO2 ratio. When substituting SiO2 by Al2O3, the mean bond strength decreases because of the weak Al-O bond relative to Si-O bond, which decreases viscosity; while the degree of polymerization is enhanced by the charge compensation effect of Al 3+ ion, which increases viscosity. Our new proposed viscosity model can well describe the viscosity variation of CaO-Al2O3-SiO2 melt.

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“…Many researchers e.g. Toplis et al, 16) Kozakevitch et al, 33) Machin et al, 34) Yasukouchi et al, 35) Scarfe et al, 36) Bills et al, 37) Johannsen et al 38) and Kita et al 39) have measured the viscosity of this system at different composition points, with the mole fraction of Al2O3 varying from 0.03 to 0.51. The parameters αAl,Ca and were optimized using more than 500 groups of viscosity data.…”

Section: Cao-al2o3-sio2 Ternary Systemmentioning

confidence: 99%

Modelling Viscosities of CaO–MgO–Al2O3–SiO2 Molten Slags

2012

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A structurally-based viscosity model (using a few optimized parameters) is proposed to represent viscosity as functions of both temperature and composition for the CaO-MgO-Al2O3-SiO2. The model represents the slag structure through the different types of oxygen ions formed in the melt. Approximate methods for calculating the concentrations of these different types of oxygen ions are proposed and are then used to describe the effect of melt structure on viscosity. The model provides a good description of the viscosity behavior varied with composition and temperature within the CaO-MgO-Al2O3-SiO2 system.

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Untersuchungen zur Frage des Diureserhythmus beim Kind

Cited by 4 publications

References 32 publications

The viscosity of magmatic silicate liquids; a model calculation

The viscosity of magmatic silicate liquids; a model calculation

Influence of Al2O3/SiO2 Ratio on Viscosities of CaO^|^ndash;Al2O3^|^ndash;SiO2 Melt

Modelling Viscosities of CaO–MgO–Al2O3–SiO2 Molten Slags

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