Showing papers on "Binary system published in 1981"
TL;DR: In this paper, a new procedure was proposed for evaluating the binary parameter δij of the Peng-Robinson equation of state, which is expressed in terms of absolute temperature as a quadratic function of which three coefficients are generalized functions of the n-paraffin acentric factor.
80 citations
TL;DR: In this paper, the authors examined the thermodynamic properties of n-alkanoate+n-alkane and +nalkane binary liquid mixtures on the basis of the group-surface interaction version of the Guggenheim-Barker quasichemical pseudolattice theory.
55 citations
TL;DR: In this article, temperature, pressure, and composition measurements are reported for the three coexisting phases in the region of the tricritical points of two ternary mixtures of hydrocarbons.
Abstract: Temperature, pressure, and composition measurements are reported for the three coexisting phases in the region of the tricritical points of two ternary mixtures of hydrocarbons: methane+n‐pentane+2,3‐dimethylbutane (I) and methane+2,2‐dimethylbutane+2,3‐dimethylbutane (II). These systems satisfy a ’’quasibinary’’ approximation in which the proportions of the two higher hydrocarbons [expressed as Z = xC/(xB+xC)] are the same in each of the three phases, so that the phase equilibrium is equivalent to that in a binary system with a solute of average properties. Least‐squares analysis does not locate the tricritical point with high precision, but all the measurements are consistent with the predictions of the phenomenological theory that the exponents governing the approach to the tricritical point are the ’’classical’’ mean‐field values. If, in accord with this view, we write the difference between the upper and lower critical‐end‐point temperatures (i.e., extent of the three‐phase region) as Tu−Tl = B(Z−Zt)...
50 citations
TL;DR: Binary compositions over the entire range of compositions of the Ag-Pd system are characterized by anodic polarization in Ringer's solution and alternate immersion in 0.5% Na 2S solution.
Abstract: Binary compositions over the entire range of compositions of the Ag-Pd system are characterized by anodic polarization in Ringer's solution and alternate immersion in 0.5% Na 2S solution. The results show that a wide range of protection and passivation tendencies are introduced with Pd alloying of Ag.
46 citations
TL;DR: Some problems connected with low-mass binary evolution (from contact binaries to cataclysmic variables and origin of bursters) are considered in this article, where the angular momentum loss by magnetic braking may, at least partly, control the contact binary evolution.
Abstract: Some problems connected with low-mass binary evolution (from contact binaries to cataclysmic variables and origin of bursters) are considered Most attention is given to contact W UMa-stars and to (still unclear) scenarios where the angular momentum loss by magnetic braking may, at least partly, control the contact binary evolution
46 citations
TL;DR: In this article, a theory of freezing of the alkali halides is developed, which is based on the basic equations of classical statistical mechanics relating the singlet densities p1 and p2 of a binary system to the three partial direct correlation functions cij.
Abstract: Using the basic equations of classical statistical mechanics relating the singlet densities p1 and p2 of a binary system to the three partial direct correlation functions cij , a theory of freezing is developed. Though the theory is set up for arbitrary concentration, we focus on the freezing of the alkali halides. In particular, we show that periodic solutions of the equations for p1 and p2 can coexist with homogeneous solutions. The difference in free energy between periodic and homogeneous phases is built up in terms of (i) the volume difference and (ii) the Fourier components of p1 , p2 and cij . To lowest order, it is stressed that the freezing transition is determined by the charge-charge structure factor at its principal peak and by the compressibility.
23 citations
Journal Article•
18 citations
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TL;DR: In this paper, 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.
17 citations
TL;DR: In this paper, the PbxSn1−xF2 solid solutions adopt various structural types following the x value, and an evolution from a completely disordered structure for the phases with high lead concentration to an ordered structure for x = 0.5 is observed.
16 citations
Journal Article•
Book•
01 Jan 1981
TL;DR: In this article, a simple synthesis method for solving the Elements of Well-Detached Eclipsing Systems is presented. But the complexity of solving the elements of well-detached eclipsing systems is not addressed.
Abstract: I: Light Changes of Eclipsing Variables and their Analysis.- The Royal Road of Eclipses.- Error Analysis of the Elements of an Eclipsing Binary System in Frequency Domain.- A Simple Synthesis Method for Solving the Elements of Well-Detached Eclipsing Systems.- The Uniqueness Criterion: The Analysis of Eclipsing Binary Light Curves.- Light Curve Analysis for the Basic Spherical-Model of Eclipsing Variables in the Frequency Domain.- A Computer Program for the Frequency-Domain Analysis of the Light Curves of Eclipsing Variables.- A Study of Special Functions in the Theory of Eclipsing Binary Systems.- Photometric Perturbations of Close Binaries in the Frequency-Domain.- An Analysis of the Light Changes of W UMa-type Systems in the Frequency Domain.- II: Eclipsing Variables: Photometric Observations.- Data Acquisition in Astronomical Photoelectric Photometry.- Detection of Close Binary Systems by Means of Lunar Occultations.- Progress and Problems in RS CVn Star Research.- Observations of RS CVn-type Binary Stars.- The System RT And and the Transit/Occultation Question.- The Short-Period Group of Eclipsing Binaries with Properties Similar to the Classical RS CVn Group.- Photoelectric Study of the RS CVn-type Binary TY Pyxidis.- BV Photometry of Selected RS CVn-type Eclipsing Binaries.- Observations and Analysis of UU Sge.- The Light and Period Variations of OO Aquilae.- Photoelectric Observations of Eclipsing Binary Systems at Kryonerion Observatory, Greece.- Stepanian's Star.- Note on the Eclipsing Binary AW Ursae Maioris.- III: Spectroscopic Studies of Close Binary Systems.- Ultraviolet Spectra of Interacting Binaries.- U Cephei Viewed from Maratea.- Certain Aspects of the Problem of Mass Transfer in Semi-Detached Binaries.- The Study of Apsidal Motion in Eclipsing Binaries.- Temperature Determination of Exciting Stars in Highly Excited Planetary Nebulae and Symbiotic Stars.- Gas Streams in Close Binary Systems.- Name Index.- Index of Individual Eclipsing Variables.
Abstract: A number of physical properties of the binary system ethylene glycol and ethyl salicylate have been measured recently. Thus measured values of surface tensions and vapor pressures as functions of composition and temperature are available, and from these may be calculated the Gibbs surface excesses of ethyl salicylate in solutions represented in the phase diagram by the one-phase area. The results of these calculations can be expressed as a series of cosorption contours superimposed on the phase diagram, showing maximum surface activity at a point (epicenter) on the co-existence curve. The epicenter would coincide with the consolute point only when the surface tensions of the two pure liquid components are equal: usually they are not equal, so that the epicenter of the contours is displaced on the co-existence curve toward the component of higher surface tension. This work reports the foam stabilities of solutions for which Gibbs surface excess concentrations are known. The foam stability contours (isaphro...
TL;DR: In this article, measurements of the thermodynamic properties and viscosities of fluid pairs are described and the results are compared with other fluid pairs employed in absorption heat pumps, and the authors compare the results with other types of fluid pair.
Abstract: Measurements of the thermodynamic properties and viscosities of fluid pairs are described and the results are compared with other fluid pairs employed in absorption heat pumps.
TL;DR: Differential scanning calorimetry on the two-component system of dioctadecyldimethylammonium chloride (DOAC) water was carried out in the temperature region from 80 °C down to -100 °C as mentioned in this paper.
Abstract: Differential scanning calorimetry on the two-component system of dioctadecyldimethylammonium chloride (DOAC)–water was carried out in the temperature region from 80 °C down to -100 °C. As the result, a new type of glassy state was found around at -40 °C for the supercooled complete gel phase.
TL;DR: In this article, the Wilson equation was used to predict the liquid phase activity coefficients in binary systems formed from 1-octene,cis-4-octenes andtrans-4 octenes with methyl cellosolve (2-methoxyethanol), 1-butanol and tetrachloroethene.
Abstract: Measurements of isobaric temperature—liquid composition are reported in the binary systems formed from 1-octene,cis-4-octene andtrans-4-octene with methyl cellosolve (2-methoxyethanol), 1-butanol and tetrachloroethene at pressures of 760 and 200 mm Hg (101.325 and 26.664 kPa). These systems have minimum boiling azeotropes. TheWilson equation is used to predict the liquid phase activity coefficients. The γ i −χ i functions thus obtained are compared in the systems containing a solvent common to the three isomericn-octenes.
TL;DR: A liquid phase partition function of the Flory-Prigogine form can be applied to strongly non-ideal liquid mixtures by accounting for non-randomness through the use of local compositions and a two-fluid theory of mixtures as discussed by the authors.
TL;DR: The experimental uncertainties in measured variables, expressed as standard deviations, are 00005 mole fraction, 001 K and 2% of measured pressure as mentioned in this paper, and the coefficients for a modified Wilson solution model are also reported.
TL;DR: In this article, total pressure, vapor-liquid equilibrium data for the binary system composed of 2-methylbutene-1 and 2methyl-1,3-butadiene are reported at 310.93, 316.48 and 322.03 K.
TL;DR: In this paper, an extension of Krupkowski's concept of predicting thermodynamic properties of multicomponent solutions from respective binaries is presented, based on the assumption that the logarithm of the activity coefficient of one component in the binary system can be represented by the formula ln γ 2 = A (T ) N 1 m − B ( T ) n 1 m + 1.
Abstract: An extension of Krupkowski's concept of predicting thermodynamic properties of multicomponent solutions from respective binaries is presented. The present work is based on the assumption that the logarithm of the activity coefficient of one component in the binary system can be represented by the formula ln γ 2 = A ( T ) N 1 m − B ( T ) N 1 m + 1 This method allows satisfactory descriptions of binary and higher order systems that exhibit negative deviation from ideality. The following examples are given, Mg Bi, Mg Sb and Sb Te In.
TL;DR: In this paper, the isobaricisothermal potential, heat, and entropy of formation of the suicide Mn3Si have been determined for the binary system Mn-Si at silicon contents ranging from 25 to 37.5 at.
Abstract: X-ray phase analyses and measurements of the emfs of concentration galvanic cells have demonstrated that Mn3Si and Mn5Si3 are the only compounds coexisting in the binary system Mn-Si at silicon contents ranging from 25 to 37.5 at. %; Mn5Si2 does not form under these conditions. The isobaricisothermal potential, heat, and entropy of formation of the suicide Mn3Si have been redetermined.
TL;DR: In this article, the surface tension of triethylamine-water was determined by standard methods, and the most interesting result is that of surface tension which indicates that, in the case of the binary system triethyllamine and water, a surface layer of constant composition is formed over a wide range of total composition, and when a rise in temperature of two or three degrees, this layer becomes unstable, it splits into two phases of different composition.
Abstract: The properties named in the title have been determined by standard methods. Viscosity, molar volume, and orientation polarisation all indicate abnormalities of the nature of association between the components.The most interesting result is that of surface tension which indicates that, in the case of the binary system triethylamine–water, a surface layer of constant composition is formed over a wide range of total composition. When, by a rise in temperature of two or three degrees, this layer becomes unstable, it splits into two phases of different composition. The surface layer may then be instantaneously reformed and so on. A mechanism for the generation of a two-phase system is thus established. The data for the three-phase, isothermal, system are not so convincing, for reasons that are suggested.
TL;DR: In this article, the size and free energy of the two-dimensional nucleus corresponding to a saddle point in binary system are derived and the velocity of the straight step in the A-B crystal-binary solution interface is found.
Abstract: A two-dimensional nucleation is required to grow the crystals of low energy planes. Expressions for the size and free energy of the two-dimensional nucleus corresponding to a saddle point in binary system are derived. The concentration of the critical nuclei in the system is related to the critical free energy of the two-dimensional nucleus. A circular island of atoms on the growing surface is considered and the flux of atoms on the surface going to the growing walls of the island from either direction is calculated. The rate of advance of the curved step is determined and hence the velocity of the straight step in the A-B crystal-binary solution interface is found.
01 Jan 1981
TL;DR: In this article, temperature, pressure, and composition measurements are reported for the three coexisting phases in the region of the tricritical points of two ternary mixtures of hydrocarbons.
Abstract: Temperature, pressure, and composition measurements are reported for the three coexisting phases in the region of the tricritical points of two ternary mixtures of hydrocarbons: methane+n‐pentane+2,3‐dimethylbutane (I) and methane+2,2‐dimethylbutane+2,3‐dimethylbutane (II). These systems satisfy a ’’quasibinary’’ approximation in which the proportions of the two higher hydrocarbons [expressed as Z = xC/(xB+xC)] are the same in each of the three phases, so that the phase equilibrium is equivalent to that in a binary system with a solute of average properties. Least‐squares analysis does not locate the tricritical point with high precision, but all the measurements are consistent with the predictions of the phenomenological theory that the exponents governing the approach to the tricritical point are the ’’classical’’ mean‐field values. If, in accord with this view, we write the difference between the upper and lower critical‐end‐point temperatures (i.e., extent of the three‐phase region) as Tu−Tl = B(Z−Zt)...