scholarly journals Calculation of activities in some gallium-based systems with a miscibility gap

2003 ◽  
Vol 68 (8-9) ◽  
pp. 665-675 ◽  
Author(s):  
Dragan Manasijevic ◽  
Dragana Zivkovic ◽  
Iwao Katayama ◽  
Zivan Zivkovic
Keyword(s):  
Thermodynamic Properties ◽  
Phase Diagrams ◽  
The Other ◽  
Miscibility Gap ◽  
Liquid Alloys ◽  
Duhem Equation ◽  
Coexisting Phases ◽  
Temperature Ranges

The calculations of thermodynamic properties in some gallium-based systems with a miscibility gap ? Ga?Tl, Ga?Hg and Ga?Pb are presented in this paper. The determination of the gallium activities in the mentioned liquid alloys was based on their known phase diagrams using the Zhang-Chou method for calculating activities from phase diagrams involving two liquid or solid coexisting phases. The activities of gallium in Ga?Tl, Ga?Hg and Ga?Pb system were calculated in the 973?1273 K, 573?873 K and 1000?1100 K temperature ranges, respectively. The activities of the other component in all the investigated systems were obtained by the Gibbs-Duhem equation. The results of the calculations are compared with literature data.

scholarly journals Entropy of Mixing of Cadmium-based Liquid Alloys

1970 ◽  
Vol 26 ◽  
pp. 40-45
Author(s):  
S. K. Chakrabarti ◽  
B. K. Jha ◽  
I. S. Jha
Keyword(s):  
Thermodynamic Properties ◽  
Binary Alloys ◽  
The Other ◽  
Chemical Model ◽  
Liquid Alloys ◽  
Atomic Composition ◽  
Reactive Metal ◽  
Entropy Of Mixing ◽  
Binary Liquid ◽  
Other Hand

Cadmium is a highly reactive metal. At the time of formation of binary alloys in liquidphase it often forms complexes. In the present work we have considered two such complexforming binary liquid alloys of cadmium e.g. Cd-Na and Cd-Mg. The former alloy showsanomaly in its thermodynamic properties of mixing. On the other hand, the alloyingbehavior of the latter one is symmetric around the equi-atomic composition. We havecomputed their entropy of mixing (SM) for different concentrations of the ingredients byusing the quasi-lattice chemical model. The results explain the observed anomaly as well assymmetry in SM of the present alloys.Keywords: Binary liquid alloys of cadmium; Quasi-lattice chemical model; Entropy of mixingDOI: 10.3126/jncs.v26i0.3629Journal of Nepal Chemical SocietyVol. 26, 2010Page:40-45

scholarly journals Binding Constants Determination of Ofloxacin and Ornidazole Enantiomers with Sulfated β-Cyclodextrin as Single Ligand by Capillary Electrophoresis using Three Different Linear Plotting Methods

2021 ◽  
Vol 33 (7) ◽  
pp. 1663-1670
Author(s):  
Khaldun M. Al Azzam
Keyword(s):  
Capillary Electrophoresis ◽  
Background Electrolyte ◽  
Binding Constants ◽  
Chiral Selector ◽  
The Other ◽  
Binding Parameters ◽  
Guest Binding ◽  
Different Temperatures ◽  
Temperature Ranges

The aim of this research is to use capillary electrophoresis to establish/determine the binding constants for ofloxacin and ornidazole enantiomers with the negatively charged chiral selector sulfated-β-cyclodextrin (S-β-CD). Using electrophoretic mobility values of ofloxacin and ornidazole enantiomers at various concentrations of S-β-CD used in the context of background electrolyte (BGE), binding constants were calculated using three separate linearization plots, namely double-reciprocal, X-reciprocal and Y-reciprocal. The R-ofloxacin enantiomer-S-β-CD complex had the highest inclusion affinity of the ofloxacin and ornidazole enantiomers, which matched with previously reported estimation. Every enantiomer-S-β-CD complex’s binding constants, as well as thermodynamic binding parameters, were calculated at different temperatures. The host-guest binding constants using double reciprocal fit showed greater linearity (R2 > 0.99) at all temperature ranges measured (15-30 ºC) as compared to the other two fit approaches. The thermodynamic complexation parameters were found to be dependent on the temperature of the enantiomers, as seen by the linear van’t Hoff (15-30 ºC) plot.

scholarly journals Calculation of activities in Ga-Cd and Cu-Pb binary systems

2002 ◽  
Vol 38 (3-4) ◽  
pp. 273-284 ◽  
Author(s):  
Dragan Manasijevic ◽  
Dragana Zivkovic ◽  
Zivan Zivkovic
Keyword(s):  
Melting Point ◽  
Phase Diagrams ◽  
Binary Systems ◽  
Composition Range ◽  
Entire Composition Range ◽  
Melting Point Depression ◽  
Calculation Methods ◽  
Duhem Equation ◽  
Coexisting Phases ◽  
Mutual Comparison

Calculations of activities in Ga-Cd and Cu-Pb binary systems were done based on their known phase diagrams, using different calculation methods. First, activities of cadmium at 700 K and copper at 1263 K in Ca - Cd and Cu - Pb systems, respectively, were calculated by melting point depression method and Zhang-Chou method for binary systems with phase diagrams involving two liquid or solid coexisting phases. In order to obtain activity values in the entire composition range, these methods were applied in the definite parts of composition range in both investigating systems. The same procedure was done, using modified Rao- Belton method by Chou, who used Richardson assumption. Activities of the second component in both investigating systems were calculated by use of Gibbs-Duhem equation. All calculated results were compared with literature data and mutual comparison between applied methods was done.

Models of Thermodynamic Properties of Prominences

1979 ◽  
Vol 44 ◽  
pp. 349-355
Author(s):  
R.W. Milkey
Keyword(s):  
Thermodynamic Properties ◽  
Mass Transport ◽  
Emission Spectrum ◽  
Thermodynamic Parameters ◽  
Working Group ◽  
Physical Processes ◽  
Theoretical Concepts ◽  
Group 3 ◽  
Observational Techniques

The focus of discussion in Working Group 3 was on the Thermodynamic Properties as determined spectroscopically, including the observational techniques and the theoretical modeling of physical processes responsible for the emission spectrum. Recent advances in observational techniques and theoretical concepts make this discussion particularly timely. It is wise to remember that the determination of thermodynamic parameters is not an end in itself and that these are interesting chiefly for what they can tell us about the energetics and mass transport in prominences.

Determination of the lattice translation across {110} APBs in GaAs

1988 ◽  
Vol 46 ◽  
pp. 600-601
Author(s):  
D.R. Rasmussen ◽  
N.-H. Cho ◽  
C.B. Carter
Keyword(s):  
Grain Boundaries ◽  
Lower Energy ◽  
Antiphase Boundary ◽  
The Other ◽  
Boundary Structure ◽  
Interface Plane ◽  
Inversion Symmetry ◽  
High Angle ◽  
Equilibrium Distance

Domains in GaAs can exist which are related to one another by the inversion symmetry, i.e., the sites of gallium and arsenic in one domain are interchanged in the other domain. The boundary between these two different domains is known as an antiphase boundary [1], In the terminology used to describe grain boundaries, the grains on either side of this boundary can be regarded as being Σ=1-related. For the {110} interface plane, in particular, there are equal numbers of GaGa and As-As anti-site bonds across the interface. The equilibrium distance between two atoms of the same kind crossing the boundary is expected to be different from the length of normal GaAs bonds in the bulk. Therefore, the relative position of each grain on either side of an APB may be translated such that the boundary can have a lower energy situation. This translation does not affect the perfect Σ=1 coincidence site relationship. Such a lattice translation is expected for all high-angle grain boundaries as a way of relaxation of the boundary structure.

Determination of the Burgers vector of a dislocation in a Fe-Mn alloy by weak-beam image in HVEM

1978 ◽  
Vol 36 (1) ◽  
pp. 330-331
Author(s):  
Y. Ishida ◽  
H. Ishida ◽  
K. Kohra ◽  
H. Ichinose
Keyword(s):  
High Order ◽  
Simulation Technique ◽  
The Other ◽  
Image Simulation ◽  
Diffraction Vector ◽  
Burgers Vector ◽  
Weak Beam ◽  
Beam Image ◽  
Edge Component

IntroductionA simple and accurate technique to determine the Burgers vector of a dislocation has become feasible with the advent of HVEM. The conventional image vanishing technique(1) using Bragg conditions with the diffraction vector perpendicular to the Burgers vector suffers from various drawbacks; The dislocation image appears even when the g.b = 0 criterion is satisfied, if the edge component of the dislocation is large. On the other hand, the image disappears for certain high order diffractions even when g.b ≠ 0. Furthermore, the determination of the magnitude of the Burgers vector is not easy with the criterion. Recent image simulation technique is free from the ambiguities but require too many parameters for the computation. The weak-beam “fringe counting” technique investigated in the present study is immune from the problems. Even the magnitude of the Burgers vector is determined from the number of the terminating thickness fringes at the exit of the dislocation in wedge shaped foil surfaces.

Procedures for the Quantitative Determination of Autoprothrombin C

1962 ◽  
Vol 08 (03) ◽  
pp. 434-441 ◽  
Author(s):  
Edmond R Cole ◽  
Ewa Marciniak ◽  
Walter H Seegers
Keyword(s):  
Quantitative Determination ◽  
Plasma Sample ◽  
Quantitative Measure ◽  
The Other ◽  
Clotting Time ◽  
Bovine Plasma ◽  
Autoprothrombin C

SummaryTwo quantitative procedures for autoprothrombin C are described. In one of these purified prothrombin is used as a substrate, and the activity of autoprothrombin C can be measured even if thrombin is in the preparation. In this procedure a reaction mixture is used wherein the thrombin titer which develops in 20 minutes is proportional to the autoprothrombin C in the reaction mixture. A unit is defined as the amount which will generate 70 units of thrombin in the standardized reaction mixture. In the other method thrombin interferes with the result, because a standard bovine plasma sample is recalcified and the clotting time is noted. Autoprothrombin C shortens the clotting time, and the extent of this is a quantitative measure of autoprothrombin C activity.

Determination of Factor XIII Activity and of Factor XIII Inhibitors Using an Ammonium-Sensitive Electrode

1983 ◽  
Vol 50 (02) ◽  
pp. 563-566 ◽  
Author(s):  
P Hellstern ◽  
K Schilz ◽  
G von Blohn ◽  
E Wenzel
Keyword(s):  
Factor Xiii ◽  
Normal Subjects ◽  
The Other ◽  
Activity Measurement ◽  
Factor Xiii Deficiency ◽  
Assay Procedure ◽  
Stabilization Factor ◽  
Release Method ◽  
Sensitive Electrode

SummaryAn assay for rapid factor XIII activity measurement has been developed based on the determination of the ammonium released during fibrin stabilization. Factor XIII was activated by thrombin and calcium. Ammonium was measured by an ammonium-sensitive electrode. It was demonstrated that the assay procedure yields accurate and precise results and that factor XIII-catalyzed fibrin stabilization can be measured kinetically. The amount of ammonium released during the first 90 min of fibrin stabilization was found to be 7.8 ± 0.5 moles per mole fibrinogen, which is in agreement with the findings of other authors. In 15 normal subjects and in 15 patients suffering from diseases with suspected factor XIII deficiency there was a satisfactory correlation between the results obtained by the “ammonium-release-method”, Bohn’s method, and the immunological assay (r1 = 0.65; r2= 0.70; p<0.01). In 3 of 5 patients with paraproteinemias the values of factor XIII activity determined by the ammonium-release method were markedly lower than those estimated by the other methods. It could be shown that inhibitor mechanisms were responsible for these discrepancies.

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