摘要:

AbstractThe viscosity of NaCl‐AlCl3melt mixtures has been determined in the range 0.50 ≤X AlCl 3≤ 0.80, 160°C to 300°C. The viscosity of pure AlCl3was measured over the temperature span 196°C to 286°C. A recently designed oscillating vessel viscometer was used. The method, which utilizes closed cylindrical cups subjected to vapour pressures exceeding 11 atm, is absolute and requires no calibration against reference liquids. Results are corrected for surface effects and for evaporation within the crucible. Applying Arrhenius temperature dependencies and the Arrhenius mixing rule, the viscosity is expressed as a function of temperature and composition with an overall standard deviation of 0.4% when the presence of AlCl−4, Al2Cl−7, Al3Cl−10, a

ISSN:0005-9021    

DOI:10.1002/bbpc.19790830102

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1979

数据来源: WILEY

摘要:

AbstractThe viscosity of NaF ‐ AlF3mixtures has been determined in the range 0‐35 mol‐% AlF3, 9501114°C using a recently developed oscillating cylinder viscometer. The method is absolute, with an estimated accuracy of 0.5 ‐1% SD in routine work. ‐ A model is presented that reproduces the measured viscosities within 0.55% SD. It assumes the presence of F−, AlF63‐, and AlF4−, and the Arrhenius temperature and mixture rules were used to fit model parameters to the

ISSN:0005-9021    

DOI:10.1002/bbpc.19790830103

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1979

数据来源: WILEY

摘要:

AbstractIn order to facilitate the development of predictive methods for the calculations of the viscosity of brines containing several salts, we present measurements of the viscosity of mixtures of aqueous solutions, each containing a single salt, namely KCl and NaCl in this case. The mixtures studied included one of a total nominal molality of 2 mol/kg, and three of a total nominal molality of 4 mol/kg. ‐ The measurements cover a pressure range of 030 MPa and a temperature range of 25150°C and their uncertainty is somewhat better than ± 1%. ‐ The measurements are compared with calculations based on Young's rule, which was successfully used in the past for volumetric properties of mixed brines. The comparison is positive and indicates that a start has been made towards the formulation of a predictive method of ca

ISSN:0005-9021    

DOI:10.1002/bbpc.19790830104

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1979

数据来源: WILEY

摘要:

AbstractAs a continuation of an earlier paper concerned with the viscosity of aqueous solutions of NaCl and KCl, the present paper communicates the results of precise, relative measurements of the viscosity of aqueous solutions of CaCl2. The measurements covered the entire range of composition up to saturation, all at atmospheric pressure and at 20.00, 25.00, 30.00, 40.00, and 50.00°C ± 0.01°C. The reproducibility was of the order of several parts per ten thousand, and the accuracy is estimated to be one of 0.3% at worst. ‐ As a byproduct, we obtained an accurate correlation between molality,c, and density,p, for these solutions measuring at 20.00 and 25.00°C (± 0

ISSN:0005-9021    

DOI:10.1002/bbpc.19790830105

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1979

数据来源: WILEY

摘要:

AbstractThe spherically symmetric part of the static pair‐distribution function of liquid CHCl3determined by neutron and x‐ray scattering experiments is compared with results of molecular dynamics calculations based on an (18‐6) Lennard Jones type potential. The agreement is sufficient with respect to the simplicity of the model inv

ISSN:0005-9021    

DOI:10.1002/bbpc.19790830106

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1979

数据来源: WILEY

摘要:

AbstractAn apparatus for electromagnetic cm‐wave reflection measurements on water and aqueous solutions at elevated hydrostatic pressures with a special measuring cell is described. Measurements in the pressure range 1 bar up to 1 kbar at the frequency 17.6 GHz are reported for water at the temperatures 5°C and 20°C and for an aqueous solution of triethylenediamine at 15°C. The dielectric relaxation rate derived from those measurements increases with increasing pressure. Its pressure induced variations for pure water are compared with that of the proton magnetic spin lattice relaxation time, the self‐diffusion coefficient, and the fl

ISSN:0005-9021    

DOI:10.1002/bbpc.19790830107

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1979

数据来源: WILEY

摘要:

AbstractEine Reduktionsformel, die eine Berechnung des spezifischen Volumens in Abhängigkeit von Temperatur und Druck ermöglicht und durch Messungen an kristallisationsfähigen Polymeren bereits geprüft ist, wird durch eine allgemeine Darstellung auf amorphe und 100% kristalline Polymere erweitert. Es läßt sich zeigen, daß die Konstanten der Zustandsgleichung mit Kohäsionsdruck und Covolumen zusammenhängen. Die aus der Gleichung gewonnenen Beziehungen der Druck‐ und Temperaturabhängigkeit von thermischer Ausdehnung und Kompressibilität sind auf Polymere im glasigen, teilkristallinen, 100% kristallinen und geschmolzenen Zustand und im Bereich des Phasenüberganges anwendbar. Mit den Konstanten ist es möglich, mit einer bei Atmosphärendruck bestimmten Schmelzentropie und Schmelzenthalpie deren Druckabhängigkei

ISSN:0005-9021    

DOI:10.1002/bbpc.19790830108

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1979

数据来源: WILEY

摘要:

AbstractThe kinetics of the proton transfer reaction between dihydrogen phosphate and imidazole in water with some added methanol, ethanol, and dioxan, respectively, was investigated by means of ultrasonic absorption and velocity dispersion measurements in the frequency range from 0.5 to 36 MHz. The system exhibits a single chemical relaxation time. It reflects a diffusion controlled direct transfer mechanism. The two rate constants have been evaluated as a function of the volume percentage of the added solvent. Both show a sharp maximum at about 0.5%. This effect turned out to be the more pronounced the more hydrophobe the foreign molecules are. Comparatively few molecules of such material therefore seem to appreciably increase the hydrogen bonded water structure in the hydration shells through which proton transfer is mediated.

ISSN:0005-9021    

DOI:10.1002/bbpc.19790830109

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1979

数据来源: WILEY

摘要:

AbstractBei Diffusionsmessungen mit n‐Alkanen in NaMgA‐Zeolithen wurde zwischen 523 und 750 K ein Übergang von einem Niedertemperaturzu einem Hochtemperaturzustand beobachtet. Wir deuten diesen Vorgang als eine Änderung der Kationenkonfiguration im Hohlraum unter Beteiligung des Adsorptivmoleküls. In einem thermischen Gleichgewichtsprozeß sollten derartige Kationenpositionswechsel zur Blockierung der Eingänge zum großen Hohlraum und dadurch zur Änderung des Sorptionscharakters von 5 A‐ zu 4A‐ähnlich führen. Auffallende Abweichungen vom Arrheniusgesetz und der Abfall der Mikroporen‐DiffusionskoeffizientenDzbie hohen Mg‐Gehalten und 673 K sind durch die Zustandsänderung erklärbar. Der schwankende Verlauf derDzmit der C‐Zahl der n‐Alkane bei 673 K läßt sich mit unseren M

ISSN:0005-9021    

DOI:10.1002/bbpc.19790830110

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1979

数据来源: WILEY

摘要:

AbstractThe α/β‐Ag2S‐phase diagram at the transition temperature has been determined experimentally. α‐Ag2S single crystals were grown and transformed in β‐Ag2S. Using Ag/AgJ‐probes along the crystal, the local partial Gibbs energy of Ag in Ag2S was determined as a function of time during the unidirectional transformation of α‐Ag2S into β‐Ag2S and vice versa. Additionally, polarisation measurements were performed at the α/β‐Ag2S boundary. From these measurements it is concluded that the transport of point defects from the boundary into the bulk phases is essentially rate controlling and that the exchange fluxes across the interface are high enough not to become rate determining. The concentration of point defects in front of the moving boundary and eventually in the bulk periodically supersaturates, which leads to a precipitation of these defects in

ISSN:0005-9021    

DOI:10.1002/bbpc.19790830111

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1979

数据来源: WILEY