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  • 1
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Journal of cardiovascular electrophysiology 3 (1985), S. 0 
    ISSN: 1540-8167
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 30 (1987), S. 1656-1666 
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The effect of the buoyancy-driven convection on the separation of the two constituents of a binary mixture in a long cylindrical cell is considered. This cell is designed to measure the thermal diffusion (Soret) coefficient of that mixture in a spatial (microgravity) environment. Such a cell, heated from the ends, is subjected to a nearly constant axial temperature gradient that generally presents some inclination with respect to the gravity vector, giving rise to low but three-dimensional motions. In space applications this inclination (with respect to residual gravity) is generally not known a priori. A three-dimensional simulation based on a false transient scheme with finite difference techniques is carried out in order to study the influence of the cell inclination on low convective motions. Two small values of a Grashof number, relevant for space applications (Gr=1 and Gr=3), and three values of the Soret parameter (S=−0.5, S=0, and S=0.5) have been considered. Characteristics of the flow and of its influence on the separation of constituents are given for several inclinations. Particularly interesting results are discussed for the vertical situations. Attention is focused on a molten (AgI–KI) mixture with a Prandtl number of 0.6 and a Schmidt number of 60, contained in a cylinder with an aspect ratio of 6.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 30 (1987), S. 3369-3382 
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Using the energy-conserved quantity method developed by Arnol'd [Dokl. Mat. Nauk 162, 773 (1965); Am. Math. Soc. Trans. 19, 267 (1969)] a study was made of the nonlinear stability of two inviscid fluid flows in three dimensions: (1) flow of a homogeneous fluid and (2) flow of a fluid whose energy density depends on the mass density alone (a so-called barotropic fluid). In order to implement the Arnol'd technique one must identify the quantities conserved by the flow in addition to the total energy. In the case of the two flows considered, the conserved quantities cannot be expressed in terms of the usual Eulerian variables—fluid velocity and mass density—alone. Instead the introduction of the Lagrangian labels of the fluid elements is required. A complete description of these conserved quantities, in both Eulerian and Lagrangian specifications of the fluid, is provided. The phase space of the flow is the entire Hamiltonian phase space expressed in either canonical or noncanonical variables. The nature of the flows to which the Arnol'd method is applicable is discussed in some depth. It was discovered that only time independent Eulerian flows can be discussed by the method; this result is given a general Hamiltonian context. The allowed Eulerian equilibria are displayed in detail. Finally, having the formal structure of these flows well in hand, it is shown that they are not, in three dimensions, formally stable. This results from a particle vortex stretching mechanism which is identified. The nature of the indicated instability is not revealed by this work, but may well be a slowly evolving Arnol'd diffusion kind of breakdown of the equilibrium.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 31 (1988), S. 2802-2809 
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The formulation of the Hamiltonian structures for inviscid fluid flows with material free surfaces is presented in both the Lagrangian specification, where the fundamental Poisson brackets are canonical, and in the Eulerian specification, where the dynamics is given in noncanonical form. The noncanonical Eulerian brackets are derived explicitly from the canonical Lagrangian brackets. The Eulerian brackets are, with the exception of a single term at each material free surface separating flows in different phases, identical to those for isentropic flow of a compressible, inviscid fluid. The dynamics of the free surface is located in the Hamiltonian and in the definition of the Eulerian variables of mass density, ρ(x, t), momentum density, M(x,t) [which is ρ times the fluid velocity v(x,t)], and the specific entropy, σ(x,t). The boundary conditions for the Eulerian variables and the evolution equations for the free surfaces come from the Euler equations of the flow. This construction provides a unified treatment of inviscid flows with any number of free surfaces.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 30 (1987), S. 2952-2964 
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A formulation of inviscid fluid dynamics based on the density F(x,v,t) in a single-particle phase space [x=(x1,x2,x3), v=(v1,v2,v3)] is presented. This density evolves in time according to a Poisson bracket of F with H(x,v,t)—a Hamiltonian in the same single-particle phase space. Compressible flows of barotropic fluid and homogeneous, incompressible flows are disscussed. The main advantage of the phase space density formulation over either Euler or Lagrange formulations is the algebraic and conceptual ease in making fully Hamiltonian approximations to the flow by altering H(x,v,t) and the Poisson brackets appropriately. The example of a shallow layer of rapidly rotating fluid where a Rossby number expansion is desired will be discussed in some detail. Changes of phase space coordinates that give an approximate H (expanded in Rossby number) and exact Poisson brackets will be exhibited. The resulting quasigeostrophic equations for F are two-dimensional partial differential equations to every order in Rossby number. The extension to multiple layers will be presented.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 29 (1986), S. 3562-3572 
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The convection arising in a cylindrical container, heated from the ends and designed for a measurement of Soret coefficient, is examined. A three-dimensional method using a pseudostationary scheme with a finite differences technique is used. Attention is focused on a horizontal cylinder with an aspect ratio of 6, a Prandtl number of 0.6, and a Schmidt number of 60. The influence of convection on the separation and on the mass fraction profiles is examined for moderate Grashof numbers (0.01≤GrH≤10) and realistic Soret parameters (−0.75≤S≤1). A domain is found where the flow has no influence on the separation, corresponding to a "separation'' regime. Extensions of the results to different Prandtl and Schmidt numbers and to larger aspect ratios are proposed.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    Journal of the American Chemical Society 107 (1985), S. 2528-2536 
    ISSN: 1520-5126
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Clinical and experimental pharmacology and physiology 13 (1986), S. 0 
    ISSN: 1440-1681
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: 1. Omeprazole, a substituted benzimidazole and a potent gastric antisecretory drug has been tested for inhibition of microsomal drug oxidative function in the rat.2. A single dose of 40 mg/kg prolonged pentobarbitone sleeping times from 118 (range 73–168) min to 195 (159–222) min (P 〈 0.01), pentobarbitone half-lives from 89 (63–114) to 112 (54–146) min (P 〈 0.05) and aminopyrine breath 14CO2 half-lives from 43 (37–51) to 56 (49–79) min (P 〈 0.05). Omeprazole in doses of 20 mg/kg or less had no significant effect.3. In prolonging pentobarbitone sleeping times omeprazole 40 mg/kg and an equimolar (30 mg/kg) dose of cimetidine were approximately equipotent.4. These results contrast with studies in man in which much smaller doses of omeprazole have been shown to produce clinically significant inhibition of drug metabolism.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Clinical and experimental pharmacology and physiology 16 (1989), S. 0 
    ISSN: 1440-1681
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: 1. There has been interest in the suggestion that enzyme-inducing drugs, such as anticonvulsants, may produce beneficial changes in lipoprotein levels, in particular a rise in the ratio of high density lipoprotein cholesterol to total cholesterol.2. This controlled study observed the effects of diets of charcoal or oven-cooked beef on antipyrine clearance (a commonly used measure of drug metabolizing capacity), the apparent oral clearance of phenacetin (a measure of cytochrome P448-dependent enzyme activity) and blood lipids in 18 healthy volunteers.3. Charcoal-cooked beef increased antipyrine clearance by an average of 20% (P 〈 0.059) and increased the apparent oral clearance of phenacetin fivefold (P 〈 0.01). In contrast, oven-cooked beef did not significantly alter either measure of microsomal function. Neither diet had any effects on blood lipids.4. We conclude that the type and degree of enzyme induction achieved by this type of dietary manipulation does not produce beneficial changes in lipoprotein profiles. A previously noted rise in high density lipoprotein cholesterol levels in volunteers fed charcoal-cooked beef may have been due to the effects of charcoal formed by charring of the beef during cooking.
    Materialart: Digitale Medien
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  • 10
    facet.materialart.
    Unbekannt
    London : Periodicals Archive Online (PAO)
    Journal of theological studies. n.s.:36 (1985) 510 
    ISSN: 0022-5185
    Thema: Theologie und Religionswissenschaft
    Notizen: AUTHORS AND BOOKS REVIEWED OR NOTICED
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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