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Showing papers on "Binary system published in 1976"



Journal ArticleDOI
TL;DR: In this article, a thermogravimetric technique was used to measure directly the composition of liquid metal sulphide systems in equilibrium with H2S/H2 gas mixtures.

54 citations



Journal ArticleDOI
TL;DR: In this paper, the phase boundaries at 1100 °C and improved values of the lattice parameters of the Nb-Al phases, together with their superconducting properties, are presented.
Abstract: The 1100 °C isothermal section of the Nb-Al binary system has been studied. The phase boundaries at 1100 °C and improved values of the lattice parameters of the Nb-Al phases, together with their superconducting properties, are presented. The Nb 2 Al phase proved not to be a superconductor down to 4.2 K.

29 citations



Journal ArticleDOI
A. S. Jordan1
TL;DR: In this article, a new theory of regular associated solutions (RAS) has been formulated to provide a consistent representation of binary and ternary phase equilibria in the Ga-P-Bi system.
Abstract: A new theory of regular associated solutions (RAS) has been formulated to provide a consistent representation of binary and ternary phase equilibria in the Ga-P-Bi system. The key postulate of the theory is that the major species in liquid alloys are Ga, P, and Bi atoms and Bi2 dimers. At first, the gross component activities in the Ga-Bi binary system are approximated from the dimer dissociation constant,K, and the activity coefficients of the three species (identified here with the coefficients for a ternary regular solution). The accord observed between the form of the isothermal activity data and the theory permits the determination ofK and the Ga-Bi interchange energy. These parameters are then employed in the calculation of the enthalpy and entropy of mixing and the prediction of the liquidus curve and asymmetric miscibility gap for the Ga-Bi system, all of which are in good agreement with the experimental findings. Generalization of the enthalpy and entropy of mixing for a binary RAS facilitates the derivation of the activities in the ternary system. Knowledge of the activities leads to the evaluation of the ternary liquidus isotherms over the entire composition range, since the Bi-P interchange energy can be obtained from the GaP-Bi pseudobinary liquidus data. It is found that along the pseudobinary the standard error between calculated and experimental liquidus points is 7° C. Furthermore, in P-rich liquid solutions, at any temperature below ≈R 1380°C, an open miscibility gap intersects the primary liquidus isotherms of Bi-doped GaP. The predicted miscibility gap in the Bi-P system is consistent with the fragmentary evidence. Finally, the paper discusses extensions of the RAS model to other ternary systems involving compound semiconductors wherein association in the liquid is likely.

20 citations


Journal ArticleDOI
TL;DR: Results of these experiments showed that movement of a given gas may be affected significantly by movement of other gases in the system, and application of binary gas diffusion laws to systems containing more than two gases may lead to significant errors.

13 citations


Journal ArticleDOI
01 Jan 1976
TL;DR: In this article, a numerical simulation of equilibrium gas flow in a binary system is presented for the case in which an accretion disc forms around the accreting star (primary), and preliminary results are shown for the mass ratios 0.4, 1.0 and 2.5.
Abstract: A numerical simulation of equilibrium gas flow in a binary system is presented for the case in which an accretion disc forms around the accreting star (primary). Preliminary results are shown for the mass ratios 0.4, 1.0 and 2.5. Two main conclusions are reached. First, the accretion disc is quite well defined and is comparable in size to the Roche lobe of the primary. Second, all but a few per cent of the mass transferred is accreted by the primary.

10 citations


Journal ArticleDOI
TL;DR: In this article, a method for improving on the numerical evaluation of the light changes exhibited by a distorted eclipsing binary system is presented. But this method is limited to the case of a single system.
Abstract: This paper discusses a method for improving on the numerical evaluation of the light changes exhibited by a distorted eclipsing binary system.

9 citations


Journal ArticleDOI
01 Jan 1976
TL;DR: In this article, a detailed sequence of models is calculated which follows the thermal evolution of a 2 M/sub sun/ contact binary of normal Population I abundances (X = 0.70, Z=0.02), starting at nearly equal mass and the initial instability develops into a cyclic exchange of mass with the mass fraction oscillating between 0.56 and 0.62 with a period of approx.10/sup 7/ years.
Abstract: It is shown analytically that contact binary stars coupled by a common convective envelope, the Lucy model, are almost invariably unstable when subjected to mass transfer: if either component begins to exchange mass, it will continue to do so. A detailed sequence of models is calculated which follows the thermal evolution of a 2 M/sub sun/ contact binary of normal Population I abundances (X=0.70, Z=0.02), starting at nearly equal mass. The initial instability develops into a cyclic exchange of mass with the mass fraction oscillating between 0.56< or =M/sub 1//(M/sub 1/+M/sub 2/) < or =0.62 with a period of approx.10/sup 7/ years. The system achieves thermal equilibrium on the average, but individually both stars are perpetually out of equilibrium. The instability is of a general nature and such oscillating systems can satisfactorily populate the short-period, red region of the period-color relation for W UMa stars. (AIP)

7 citations



Book
01 Jan 1976
TL;DR: In this article, a simulation of mass transfer and accretion disc flow in a closed binary system is presented, showing that mass transfer in semi-detached Binaries can be used to calculate gas flow in the formation of a supernova.
Abstract: Introductory Address.- Massive Binaries - Early Evolutionary Stages.- Binary X-Ray Stars and Supernovae of Type I.- Two Types of Evolution of Massive Close Binary Systems.- Late Stages of Close Binary Systems.- The Post-Supernova Stage of Massive Close Binaries: The Possibility of a Tidal Instability.- The Observational Situation in Regard to Black Holes.- Common Envelope Binaries.- Effect of Instantaneous Mass Ejection on Orbital Elements of Circular Binaries.- Tidal Interactions in Compact Binary Systems.- Observations of Dwarf Novae.- The Eclipsing Binary White Dwarf BD + 16 516.- Spectroscopic Observations of Southern Dwarf Novae.- Spectroscopic Observations of U Gem.- The Cause of the Nova Outburst.- Theory of Dwarf Novae.- Gravitational Radiation and the Evolution of Low Mass Binaries.- Masses and Evolution of Cataclysmic Binaries.- Angular Momentum Loss and the Origin of Cataclysmic Binaries.- Ultraviolet Observations of some Close Binary Systems by the Astronomical Netherlands Satellite - ANS.- Accretion Processes in Close Binaries.- Numerical Simulation of Mass Transfer and Accretion Disc Flow in Binary Systems.- Mass Transfer in Semi-Detached Binaries.- A Hydrodynamical Calculation of Gas Flow in a Cataclysmic Variable Star.- Coronae above Accretion Discs.- Mass Flow in Close Binary Systems.- Mass Transfer Rates in Algol Binaries Deduced from Their Period Changes.- The Algols, Red Spectra, Be Stars, and Even Neutrinos.- Notes on the Interpretation of Observations of Circumstellar Matter in Binary Systems.- Observations of Gaseous Disks in Close Binaries.- Starspot Activities as an Interpretation for the Light Curve Changes of the Close Binary Star XY UMa.- Identification of3 He in the Binary System 68u Her.- The Mass-Exchange Binary Sco X-l.- Evolutionary Status of Massive Algols - a Revision of Classical Theory.- Contact Binaries.- Unsteady Mass Loss in Close Binaries.- A Cyclic Thermal Instability in Contact Binary Stars.- Energy Transfer in Contact Binaries.- Progress in Contact-Binary Energy Transfer.- Evolution of Contact Systems.- The Evolution of Contact Binaries.- UBV Photometry of the Shortest Period Contact Binary CC Com.- Four-Colour Survey of W-UMa-Type Systems.- Rotational Angular Momenta of Close Binary System Components.- An Aspect of Star Fission.- Statistics of Binary Stars: Semi-Major Axes.- The Origin of the RS CVn Binaries.- Concluding Remarks.- Author Index.- Star Index.

Journal ArticleDOI
01 Jan 1976
TL;DR: In this paper, the role of the critical Roche lobe in mass transfer in X-ray binary systems was examined with a special view to take into account relevant physical conditions such as radiation pressure that may affect the restricted three body problem treatment.
Abstract: The manner of mass flow in close binary systems is examined with a special view to the role of the so-called critical Roche (or Jacobian) lobe, taking into consideration relevant physical conditions such as radiation pressure that may affect the restricted three-body problem treatment. The mass does not necessarily flow from component one to component two through the L1 point to form a gaseous ring surrounding the latter. These considerations are applied to X-ray binaries with early-type optical components, such as Cyg X-1 (HDE 226868) and 3U 1700 - 37 (HD 153919). In the two bright close binary systems Beta Lyr and UW CMa, which are believed to be undergoing dynamic mass transfer, recent Copernicus observations show that the gas giving rise to the prominent ultraviolet emission lines surrounds the entire binary system rather than merely component two. Implications of these observations are also discussed.


Journal ArticleDOI
TL;DR: The phase diagram of the binary system KNO3 + KO2 has been determined in this article, and the experimental temperature of fusion of the commercial KO2 is (773 ± 1) K.



Journal ArticleDOI
TL;DR: The orbital elements of the single line spectroscopic binary ADS 14893 B have been determined in this paper, and the magnitude difference between stars 14893 A (F7 V) and 14893 Ba (F8 V) is tentatively found to be degreem=0.04 +- 0.025 mag.
Abstract: The orbital elements of the single line spectroscopic binary ADS 14893 B have been determined. The magnitude difference between stars 14893 A (F7 V) and ADS 14893 Ba (F8 V) is tentatively found to be degreem=0.04 +- 0.025 mag. The mass ratio q=2.257 of the spectroscopic binary to ADS 14893 A indicates that the unobserved star is possibly the most massive star in the ADS 14893 system and could be a degenerate star. The visual binary period is about 6 years. Three preliminary sets of visual binary orbital elements are determined, from which three radial velocity ephemerides of ADS 14893 A are calculated through 1980. (AIP)


Journal ArticleDOI
01 Jan 1976
TL;DR: In this article, the rotational angular momentum, J rot, and orbital angular momentum J orb, in close binary systems and its variation with mass ratio was studied and the tables and graphs gave this variation for detached systems, contact systems, semidetached systems and for systems containing a supernova-remnant component and a contact component.
Abstract: The ratio between rotational angular momentum, J rot , and orbital angular momentum, J orb , in close binary systems and its variation with mass ratio is studied. The tables and the graphs give this variation for detached systems, contact systems, semidetached systems and for systems containing a supernova-remnant component and a contact component. For this study some statistical relations of close binary stars were used. The ratio J rot / J orb is sensitive to the variation of the mass ratio q. If q differs much from unity and if the concentration of the stellar matter is moderate (polytropic index n ~ 3), the neglect of rotational angular momentum, J rot , is not justified.

Journal ArticleDOI
TL;DR: In this paper, a new expression for the liquid phase activity coefficient is presented, which is a modification of the quasi-chemical theory and contains only two adjustable parameters per binary system provided that the coordination number is fixed to be 4 to 6.
Abstract: A new expression for the liquid-phase activity coefficient is presented. It is a modification of the quasi-chemical theory. The new equation contains only two adjustable parameters per binary system provided that the coordination number is fixed to be 4 to 6. The capability of the equation is tested with typical nonideal binary systems. Extension of the equation to ternary systems is demonstrated with examples of vapor-liquid and liquid-liquid equilibrium prediction from binary data alone.

Journal ArticleDOI
TL;DR: Astrometry and photometry of LP 380-5/6 reveal that this binary system contains a very late-type degenerate star and a late -type red dwarf.
Abstract: Astrometry and photometry of LP 380-5/6 reveal that this binary system contains a very late-type degenerate star and a late-type red dwarf. (AIP)

Journal ArticleDOI
01 Jan 1976
TL;DR: In this article, the authors examined the distribution of the semi-major axes of binary systems in the Sixth Catalogue of the Orbital Elements of Spectroscopic Binary Systems (and its extensions) and the correlation of semimajor axis with other properties of the systems.
Abstract: We have examined the distribution of the semi-major axes of the binary systems in the Sixth Catalogue of the Orbital Elements of Spectroscopic Binary Systems (and its extensions) and the correlation of semi-major axis with other properties of the systems. The total distribution has a single peak near a sin i =10 7 km. Evolved systems have wider separations and smaller mass ratios than unevolved systems. Among each type separately, the distribution of mass ratios is bimodal and small mass ratio is correlated with large separation. These data appear to show evidence of two mechanisms of binary system formation and of the process of mass transfer in close binaries.

01 Dec 1976
TL;DR: In this paper, the method of Kaufman and coworkers is used to provide an estimate of isothermal sections of the Al-Li-Mg system, where the lattice stability of the constituents, the binary interaction coefficients and the binary compound parameters are calculated.
Abstract: The method of Kaufman and coworkers is used to provide an estimate of isothermal sections of the Al--Li--Mg system. One starts by calculating the lattice stability of the constituents, the binary interaction coefficients and the binary compound parameters. In the computations, thermodynamic data, when available, were coupled with measured phase diagrams to provide thermodynamically self-consistent liquidus and solidus curves for the binary systems. Standard enthalpies of formation and entropies of formation were calculated for the reported compounds. The binary system Li--Mg illustrates the use of such calculations in selecting the most reliable representation of the phase diagram. The calculated binary data were used to compute the phase diagram of Li--Al--Mg, assuming that no ternary compounds exist. 4 tables, 7 figures, 29 references. (GHT)

01 Jan 1976
TL;DR: In this paper, the properties of the binary system in different regions of the electromagnetic spectrum from X-rays to the radio are presented from the point of view of the radio and physical parameters and a model for the system are derived.
Abstract: The properties of the binary system in the different regions of the electromagnetic spectrum are presented from X-rays to the radio. Physical parameters and a model for the system are derived.

Journal ArticleDOI
TL;DR: The phase diagram of the Ge-As-Te system has been investigated by means of physico-chemical methods (differential-thermal analysis/DTA/, X-ray Debye-Scherrer powder patterns and diffraction, microstructure and microhardness) as mentioned in this paper.



Journal Article
TL;DR: In this article, a numerical simulation of equilibrium gas flow in a binary system is presented for the case in which an accretion disc forms around the accreting star (primary), and preliminary results are shown for the mass ratios 0.4, 1.0 and 2.5.
Abstract: A numerical simulation of equilibrium gas flow in a binary system is presented for the case in which an accretion disc forms around the accreting star (primary). Preliminary results are shown for the mass ratios 0.4, 1.0 and 2.5. Two main conclusions are reached. First, the accretion disc is quite well defined and is comparable in size to the Roche lobe of the primary. Second, all but a few per cent of the mass transferred is accreted by the primary.

Journal ArticleDOI
TL;DR: The phase diagram of a binary system with a complex isomers pair, namely, picric acid (PiOH)-o-bromoaniline (BrA), has been elaborated by scanning calorimetry as discussed by the authors.
Abstract: Phase diagram of a binary system with a complex isomers pair, picric acid (PiOH)-o-bromoaniline (BrA) has been elaborated by scanning calorimetry. Two compounds have been found in the system viz. BrA-PiOH (melting point 408 K) and (BrA)2-PiOH (incongruently melting at 342 K). BrA-PiOH forms solid solutions with both PiOH and BrA in the concentration range extending from 45 to 52 mpc PiOH. Temperature of the phase transition salt/complex amounts to 375 K for stoichiometric Bra-PiOH and 370 or 377 K for terminal solutions with excess of PiOH or BrA respectively. Heat of transition for stoichiometric compound amounts to 24.7 kJ/mole. Dc-electric resistivity of BrA-PiOH increases in the course of the salt/complex transition.