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Showing papers on "Binary system published in 1980"


Journal ArticleDOI
TL;DR: In this paper, phase diagrams for bulk nuclear matter at finite temperatures and variable proton concentrations are presented and discussed, showing that a binary system exhibits a line of critical points, line of equal concentrations, and a line-of-maximum temperatures.
Abstract: Phase diagrams for bulk nuclear matter at finite temperatures and variable proton concentrations are presented and discussed. This binary system exhibits a line of critical points, a line of equal concentrations, and a line of maximum temperatures. The phenomenon of retrograde condensation is also possible.

51 citations



Journal ArticleDOI
P. Dörner1, E.-Th. Henig1, H. Krieg1, Hans Leo Lukas1, Günter Petzow1 
TL;DR: In this article, a least square method of optimizing thermodynamic functions has been taken to prepare a data set of the system Al  Si, and two types of data sets are presented and compared with a former computation of this system.
Abstract: A least squares method of optimizing thermodynamic functions has been taken to prepare a data set of the system Al  Si. Two types of data sets are presented and compared with a former computation of this system. The calculated phase diagram, as well as the enthalpy and the partial Gibbs free energy of the melt, agree well with the experimental data.

43 citations


Journal ArticleDOI
TL;DR: In this paper, the enthalpy of formation of YH2 at 919 K was found to be −52.8±0.4 kcal/mole−1.
Abstract: The binary system, yttrium–hydrogen, has been studied at 919 K at pressures up to 1 atm by a calorimetric–equilibrium method. From the calorimetric measurements we found the enthalpy of formation of YH2 at 919 K to be −52.8±0.4 kcal mole−1. The calorimetric results are in very good agreement with some of the enthalpies reported in a recent equilibrium investigation. Comparisons between the calorimetric measurements and the available equilibrium data provide new information on the partial entropy of hydrogen both in close packed hexagonal yttrium, and in the nonstoichiometric dihydride YH2−δ. For both phases we find the partial excess entropy of hydrogen near 1000 K to be about +5 cal mole−1 K−1; this value is essentially fully accounted for by the vibrational entropy contributions of hydrogen.

17 citations



Journal ArticleDOI
TL;DR: In this paper, the authors used the Knudsen effusion method combined with mass spectrometric analysis of the gaseous phase composition at temperatures from 1273K to 1373K, and found that NaBO 2 and (NaBO 2 ) 2 molecules were found in the vapour over the melts of the system containing 0.10 molar fraction of Na 2 O as well as B 2 O 3 and GeO 2 in molar ratio 4:1.
Abstract: This work was performed using the Knudsen effusion method combined with the mass spectrometric analysis of the gaseous phase composition at temperatures from 1273K to 1373K. The vapour composition over the Na 2 OB 2 O 3 GeO 3 melts was shown to depend on both the composition of condensed phase and the temperature, and the vapour composition over the Na 2 OB 2 O 3 , Na 2 OGeO 2 , B 2 O 3 GeO 2 melts corresponds mainly to that over the pure oxides forming these systems. At 1273K the NaBO 2 and (NaBO 2 ) 2 molecules were found in the vapour over the melts of the system containing 0.10 molar fraction of Na 2 O as well as B 2 O 3 and GeO 2 in molar ratio 4:1. Besides the indicated molecules, atomic sodium, germanium monoxide and oxygen were also found in the vapour over the 0.40Na 2 O0.30B 2 O 3 0.30GeO 2 and 0.40Na 2 O0.12B 2 O 3 0.48GeO 2 melts. The partial vapour pressures, activities, chemical potentials, partial molar enthalpies and entropies of the binary system components were determined. The thermodynamic functions of the Na 2 OB 2 O 3 , Na 2 OGeO 2 and B 2 O 3 GeO 2 melts agree with the structure of these melts adopted at present. The experimental values of excess free energy for the melts of a ternary system are compared with the values calculated from thermodynamic functions using the Kohler method.

12 citations


Journal ArticleDOI
TL;DR: In this article, a preliminary study of the eclipsing binary AB Cas is presented by using the photometric observational data, where the primary component is one of the δ Sct variables with period of 0.054, and whether the oscillation is of a radial mode or of a non-radial one is discussed.
Abstract: Preliminary study of the eclipsing binary AB Cas is presented here by using the photometric observational data. The primary component is one of the δ Sct variables with period of 0d.054, and whether the oscillation is of a radial mode or of a non-radial one is discussed. Two colour indices (B-V andU-B) data and the light curve analysis suggest that this binary system is a typical Algol type binary system, in which the primary component is near the ZAMS with about 2.3M ⊙ and the secondary one is a subgiant star with about 0.5M ⊙.

9 citations


Journal ArticleDOI
TL;DR: In this paper, alloys were studied in the Cd-Sn binary system at high pressure and a non-linear change in eutectic composition as a function of pressure was found with a total variation of 8.04 at.
Abstract: Alloys were studied in the Cd-Sn binary system at high pressure. These data allow the construction of the x - T - P phase diagram up to 4.0 GPa. A non-linear change in eutectic composition as a function of pressure was found with a total variation of 8.04 at.% over 3 GPa. The high temperaturehigh pressure phase transitions observed can be linked to those in tin and to a new transition in the high temperature peritectic compound β.

8 citations


Journal ArticleDOI
TL;DR: By two-partition approximation of the distribution function, the growth kinetics is obtained of binary crystals, whose kinetic phase diagrams have the type of a cigar, a cigar with a maximum, a cigars with a minimum, and of simple eutectics.
Abstract: By two-partition approximation of the distribution function, the growth kinetics is obtained of binary crystals, whose kinetic phase diagrams have the type of a cigar, a cigar with a maximum, a cigar with a minimum, and of simple eutectics The way is studied in which the shape of the kinetic phase diagrams, the growth rate, the effective distribution coefficients, and other characteristics of the process depend on the microscopic parameters of the model [Russian Text Ignored]

7 citations





Journal ArticleDOI
TL;DR: In this paper, the Gibbs-Duhem equation is uncoupled to give an independent equation for each partial molar quantity and the resulting solution is formally identical to that for a binary system.
Abstract: The Gibbs–Duhem equation is uncoupled to give an independent equation for each partial molar quantity. The resulting solution is formally identical to that for a binary system. The method of application of the equations and their advantage over previous formulations are discussed.

Journal ArticleDOI
TL;DR: The Co-Ga binary system has been investigated by X-rays in conjunction with differential thermal analysis as discussed by the authors, and it has been established that besides Ga and γ-Co which is the room temperature modification of pure cobalt, there are three phases in the entire system, α',β and ψ.
Abstract: The Co-Ga binary system has been investigated by X-rays in conjunction with differential thermal analysis. It has been established that besides Ga and γ-Co which is the room temperature modification of pure cobalt, there are three phases in the entire system, α',β and ψ. α' is a superstructure phase based on a face-centred cubic fundamental lattice, and may be considered as a solid solution of α-Co which is the high temperature form of pure cobalt, stabilized at room temperature due to the addition of gallium. The homogeneous range of this phase at room temperature is 2.4-10.7 at % Ga. The β phase is formed by a peritectic reactio α + L = β at 1177℃, with a homogeneous range 36.3-59.8 at % Ga at room temperature. The structure of this phase is of the CsCl (B2) type. The lattice spacing changes with composition in such a way that it rises at first, reaches a maximum, and then falls off with the gallium content. This is similar to the β phase in the Al-Ni system. In the Co-rich side of the maximum, it appears as a substitutional type solid solution, while in the Ga-rich side, it belongs to the defect type, the addition of Ga atoms being equivalent to the dropping off of some Co atoms from the normal lattice. The homogeneous range of the ψ phase is extremely narrow, existing only at the near neighbourhood of the stoichiometric composition 75 at % Ga. This phase belongs to the tetragonal system with space group D4h14 -P42/mnm. Bach unit cell contains four formula weights CoGa3, and the lattice spacings at 75.4 at % Ga and 20℃ are α = 6.2365A, c = 6.4347 A, c/a = 1.0318. It is formed peritectically (α + L=(?))at 833℃. Neither Ga in γ-Co nor Co in Ga shows any detectable solid solubility. There exists an eutectic horizontal from CoGas to Ga at 27℃, with the eutectic point very close to pure gallium.

Journal ArticleDOI
TL;DR: The phase diagram of the binary system PbOGd 2 O 3 was determined by means of DTA, X-ray and high-temperature microscopy measurements as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this article, the effects of formation of a binary black hole in a dense star cluster are found to have significant effects on the dynamics of the cluster, and it is suggested that the high-density cluster core provides a suitable environment for the operation of a number of models for the core of active galactic nuclei.
Abstract: The effects of formation of a binary black hole in a dense star cluster are found to have significant effects on the dynamics of the cluster. Tidal destruction of stars captured into bound orbits during the formation of the black hole binary provide a sizeable source of very high temperature thermal radiation as well as a source of radially outward moving clouds of gas. The efficiency of subsequently accreted matter onto the binary components as an energy source is investigated and suggestive evolutionary models of the dynamics of the binary system are presented. Lifetimes of the system are shown to be compatible with contemporary estimates. It is suggested that the high-density cluster core provides a suitable environment for the operation of a number of models for the core of active galactic nuclei.


Journal ArticleDOI
TL;DR: In this paper, the Cd-Tl binary alloy system was studied to 3.4 GPa and the thermal stability field of the β phase was increased with increasing pressure.
Abstract: The Cd-Tl binary alloy system was studied to 3.4 GPa. Minimal, if any, compositional changes occur as a function of pressure. The thermal stability field of the β phase is increased with increasing pressure. The composition temperature diagram at high pressures is presented and discussed. The high pressure solid-solid transition in pure thallium is moved to higher pressures by the addition of cadmium.


Journal ArticleDOI
TL;DR: In this article, the detection of X-ray emission in the 0.15-2 keV band from the vicinity of the radio-emitting binary star HD 146361 in the binary system sigma-Corona Borealis, with low-energy detectors of the HEAO A-2 experiment, is reported.
Abstract: The detection of X-ray emission in the 0.15-2 keV band from the vicinity of the radio-emitting binary star HD 146361 in the binary system sigma-Corona Borealis, with low-energy detectors of the HEAO A-2 experiment, is reported. Graphs are presented that show plots of count rate versus scan angle in half-degree bins, that are obtained from the superposition of the 13 source scans. Attention is given to source position and identification as well as to the energy spectrum of the source.

Journal Article
TL;DR: In this article, the authors reviewed progress made over the last decade in the understanding of the binary X-ray pulsars and discussed the characteristics of the pulse profiles of the known binary pulsars, and observed variations in pulse period corresponding to the spin-up of the neutron star are considered.
Abstract: Progress made over the last decade in the understanding of the binary X-ray pulsars is reviewed. The characteristics of the pulse profiles of the known binary X-ray pulsars are discussed, and observed variations in pulse period corresponding to the spin-up of the neutron star are considered. Determinations of the orbits and binary system parameters of the binary X-ray pulsars from measurements of pulse arrival times are then examined. Attention is also given to current problems in binary X-ray pulsars, including the apsidal motion test, which allows the determination of the mass distribution within a star, the X-ray source 4U 1626-67, which is believed to be a highly compact binary X-ray source, and the observation of very faint X-ray pulsars with the Einstein Observatory.

Journal ArticleDOI
TL;DR: In this paper, a supernova explosion in a binary system is presented as an application of classical mechanics, and the realistic assumptions that the original binary system was circular, the mass loss instantaneous and the companion unaffected by ejected matter, permit a simple, analytic determination of the post-explosion binary.
Abstract: A supernova explosion in a binary system is presented as an application of classical mechanics. The realistic assumptions that the original binary system was circular, the mass loss instantaneous, and the companion unaffected by ejected matter, permit a simple, analytic determination of the post‐explosion binary. The period, semimajor axis and mass function of the original circular binary are related to the period, semimajor axis and mass function of the present binary. The space velocities of the post‐explosion components are derived. The results are of current interest in connection with O,B runaway stars, collapsed stars in binary x‐ray sources and with the discovery of a pulsar in a binary system.