Showing papers on "Binary system published in 1972"

Roche potentials including radiation effects

Abstract: A modified Roche potential which incorporates the effects of radiation pressure due to one component of a binary system is mathematically explored. In some cases, the resulting potentials do not exhibit the familiar contact surfaces of the classical Roche potential. The concept of a contact surface, which has been fundamental to the investigations of close binary systems, must be used with discretion for close binaries in which one component is very luminous. A convenient criterion for the existence of a contact surface is given by (1-μ) ≃ 3δc 3/2 $$(1 - 2(\tfrac{2}{3})^4 \delta _c )$$ , (δc≪1) where μ is the mass of the very luminous star in terms of the system mass. For systems of given μ, no contact surface exists if δ is greater than δc where δ is the ratio of radiation pressure force to gravitational attraction. Furthermore, energy considerations of the modified Roche potential indicate that binary systems with δ < δc should have a greater tendency to form rings than those with δ < δc.

Dimensions of the Binary System HDE 226868 = Cygnus X-1

Abstract: Recent observations of the binary star HDE 226868, which is believed to be associated with Cygnus X-1, are here combined with data already published to obtain improved orbital elements for the binary system. The data imply that the secondary is a black hole.

Phase Diagram and Growth of Single Crystals in the Anthracene-Acridine Binary System

Abstract: The revision of the phase diagram of the anthracene-acridine system by thermal analysis revealed the compositions of terminal solid solutions amounting to 2 and 88 mole % of anthracene respectively, and a eutectic at 8% of anthracene and 384.4[ddot]K. Relatively stable binary single crystals of composition ranging from 0 to 45 mole % of acridine in anthracene and from 2 to 10 mole % of anthracene in acridine have been obtained by the vapour growth technique. The lattice constants of the mixed crystals have been determined.

The binary system ZnONb2O5

Abstract: Phase relationships in the binary system ZnONb2 O5 have been re-determined. The compounds 3ZnO.Nb2O5, α-ZnO.Nb2O5, β-ZnO.Nb2O5 and 2ZnO.17Nb2O5 have been encountered. The compounds 3ZnO.Nb2O5 and β-ZnO.Nb2O5 melt congruently at 1312 °C and 1405 °C, respectively, but 2ZnO.17Nb2O5 melts incon-gruently to liquid +H-Nb2O5 at 1415 °C and exists at temperatures above 1085 °C. The α⇆β polymorphic transition in ZnO.Nb2O5 occurs at 1350 °C. X-ray powder diffraction data for α-ZnO.Nb2O5, β-ZnO.Nb2O5 and 2ZnO.17Nb2O5 are given.

On the orbital eccentricity on an eclipsing binary system

Abstract: A new method is presented to precisely deduce the orbital eccentricity of an eclipsing binary from observed epochs of its light minima. Application to the system V526 Sagittarii givese=0.2220±0.0016.

A Spectroscopic Study of AS Camelopardalis

Abstract: Spectrographic observations of this eclipsing binary system are presented for the first time. It is shown that both components are main-sequence stars which conform to the theoretical calculations of Iben (1967). Key words: eclipsing binary - radial velocities - orbital elements

Self-Diffusion Coefficients and Interdiffusion Coefficient in Acetone–Benzene System

Abstract: Self-diffusion coefficients of acetone and benzene have been determined in the whole composition range of the binary system at 25°C by a capillary-cell method using the 14C-marked tracer. The results were in a good agreement with those determined by the NMR spin-echo method by McCall and Douglass. The products of the respective self-diffusion coefficients and the viscosity of this system showed a relatively constant compositional dependence. Bearman’s relation was shown to hold between the self-diffusion coefficients and the partial molar volumes for the system. The validity of Darken’s equation was confirmed for the self-diffusion coefficients and the interdiffusion coefficient of the system.

Multicomponent mass transfer in turbulent flow

Abstract: A general treatment of entry region multicomponent mass transfer between a fully developed turbulent flow and a smooth pipe wall has been developed from a basis first derived by Toor. The couled multicomponent equations were reduced to an equivalent binary system by the method of undetermined constants. Numerical solutions for a forced convection, binary diffusion system involving gas-phase, nonequimolal diffusion were applied to a ternary system. These solutions have been found to compare well with these authors entry region mass transfer data on a ternary acetone-methonal-air mixture and with the earlier analogy theories derived for the case of an infinitely long test section. We conclude that there is a significant interaction in some multicomponent systems, enough that the binary theory can not be satisfactorily applied in the design of multicomponent mass transfer systems.

Ternary Diffusion in the 20Ne–22Ne–CO2 System

Abstract: Self-diffusion coefficients of CO2 of the binary system of Ne and CO2 were measured for the whole composition range at 25°C under 760 mmHg. The system was also analysed as a ternary system of 20Ne, 22Ne, and CO2. The isotope separation of 20Ne and 22Ne during the course of diffusion was measured and analyzed by means of the ternary diffusion equations obtained by an extension of Darken’s binary diffusion equation. The experimentally observed 22Ne/20Ne ratios agreed well with the values calculated by the equations. The results show that the concept of the intrinsic diffusion flux density, introduced by Darken for binary diffusion, is valid and applicable to ternary diffusion in the gaseous system.

Alloys of thorium with certain transition metals V. The ThOs2ThIr2 pseudo-binary system and some additional results on the thorium-iridium system

Abstract: The ThOs2ThIr2 pseudo-binary system has been studied by X-ray and metallographic methods. The composition range of stability of the cubic C15-type phase was investigated and some information was obtained on the stability of other phases in the ternary system. Some new metallographic results on binary ThIr alloys containing 66–83% Ir ★ are also reported.

Comparison of two gas chromatograph models and analysis of binary data

Abstract: The overall objective of the gas chromatograph system studies is to generate fundamental design criteria and techniques to be used in the optimum design of the system. The particular tasks currently being undertaken are the comparison of two mathematical models of the chromatograph and the analysis of binary system data. The predictions of two mathematical models, an equilibrium absorption model and a non-equilibrium absorption model exhibit the same weaknesses in their inability to predict chromatogram spreading for certain systems. The analysis of binary data using the equilibrium absorption model confirms that, for the systems considered, superposition of predicted single component behaviors is a first order representation of actual binary data. Composition effects produce non-idealities which limit the rigorous validity of superposition.

Vapor Pressure of a Mixed System of Asphaltene and Organic Solvent

Abstract: The vapor pressure of a system in which it is assumed that the maltene component in petroleum asphalt has been replaced by an organic solvent, i.e., a mixed system of an asphaltene component and an organic solvent, was measured over a wide range of composition. The experimental results were then analyzed on the assumption that such a system is a binary system and that the equation μ1=μ1°+RTln(1–v2)+(1–1⁄z)v2+χ1v22 which Flory and Huggins derived for the chemical potential of a solvent of a linear, high-polymer solution which is not relatively dilute is applicable; the volumetric ratio, z, of the asphaltene particle and solvent molecule and the value of the parameter, χ1, of the interaction of the asphaltene and solvent molecules were obtained. The above results made it clear that mixed systems of asphaltene plus chloroform and carbon tetrachloride all form a homogeneous phase over the entire composition range, but in the case of a cyclohexane system, separation into 2 phases occurs in the mixed compositio...

Investigation of the Melting Behaviour of Organic Substances by Differential Scanning Calorimetry

Abstract: The melting behaviour of a eutectic system is commonly described by thermodynamic relations in the region of solid-liquid equilibria. The form of these functions is dependent on the degree of ideality of the system and on mathematical approximations. For the binary system phenacetin­benzamide theoretical and experimental phase diagrams have been compared. Two equations of the solubility equilibrium were transformed into specific heat functions. For both phenacetin and bengamide as main components the specific heat functions were calculated and plotted and the differences of these functions are discussed. On the other hand these specific heat functions nave been compared with melting curves measured with the DSC-IB.

Investigation of the Solid Solutions of Calcium Hydrogermanosilicates by Thermal Analysis and Other Physico-Chemical Methods

Abstract: The 8-Ca2(SixGe1-x)O4 mixed crystals were subjected to hydrothermal treatment in the temperature range 120–260°C. The phase composition of the products of hydration as a func­tion of the temperature of hydrothermal treatment is expres­sed by the diagram of the pseudo binary system 2CaOGeO2nH2O. Complete series of solid solution with the structure of α- and 8-hydrates of Ca2SiO4 exist in the system.