Showing papers on "Binary system published in 2013"
TL;DR: In this paper, the morphology evolution of Ni-Co binary hydroxides was studied varying from nanosheets, to nanoplate-nanospheres, to nanorods and to a nanoparticle geometry by simply controlling the Co:Ni ratio in the initial reactant.
164 citations
TL;DR: In this paper, the authors used an extensive light curve from the SuperWASP survey augmented by published radial velocities and UBV light curves to measure the physical properties of the system.
Abstract: The eclipsing binary LLAqr consists of two late-type stars in an eccentric orbit with a period of 20.17d. We use an extensive light curve from the SuperWASP survey augmented by published radial velocities and UBV light curves to measure the physical properties of the system. The primary star has a mass of 1:167 0:009M and a radius of 1:305 0:007R . The secondary star is an analogue of the Sun, with a mass and radius of 1:014 0:006M and 0:990 0:008R respectively. The system shows no signs of stellar activity: the upper limit on spot-induced rotational modulation is 3mmag, it is slowly rotating, has not been detected at X-ray wavelengths, and the calcium H and K lines exhibit no emission. Theoretical stellar models provide a good match to its properties for a sub-solar metal abundance of Z = 0:008 and an age of 2.5Gyr. Most low-mass eclipsing binary systems are found to have radii larger than expected from theoretical predictions, blamed on tidally-enhanced magnetic fields in these short-period systems. The properties of LLAqr support this scenario: it exhibits negligible tidal e ects, shows no signs of magnetic activity, and matches theoretical models well.
117 citations
TL;DR: In this article, KIC 10661783 is an eclipsing binary that shows Scuti-like oscillations and 60 pulsation frequencies have been detected in its light curve as observed by the Kepler satellite.
Abstract: Context KIC 10661783 is an eclipsing binary that shows δ Scuti-like oscillations More than 60 pulsation frequencies have been detected in its light curve as observed by the Kepler satelliteAims We want to determine the fundamental stellar and system parameters of the eclipsing binary as a precondition for asteroseismic modelling of the pulsating component and to establish whether the star is a semi-detached Algol-type systemMethods We measured the radial velocities of both components from new high-resolution spectra using TODCOR and compute the orbit using PHOEBE We used the KOREL program to decompose the observed spectra into its components, and analysed the decomposed spectra to determine the atmospheric parameters For this, we developed a new computer program for the normalisation of the KOREL output spectra Fundamental stellar parameters are determined by combining the spectroscopic results with those from the analysis of the Kepler light curveResults We obtain T eff , log g , v sini , and the absolute masses and radii of the components, together with their flux ratio and separation Whereas the secondary star rotates synchronously with the orbital motion, the primary star rotates subsynchronously by a factor of 075 The newly determined mass ratio of 00911 is higher than previously thought and means a detached configuration is required to fit the light curveConclusions With its low orbital period and very low mass ratio, the system shows characteristics of the R CMa-type stars but differs from this group by being detached Its current state is assumed to be that of a detached post-Algol binary system with a pulsating primary component
78 citations
TL;DR: In this article, an overview of the excess enthalpies of binary mixture containing ionic liquid and molecular solvent is reported, taking into account the various structural features of both the ions and solvents.
Abstract: In this work, an overview of the excess enthalpies of binary mixture containing ionic liquid and molecular solvent is reported, taking into account the various structural features of both the ionic liquid and molecular solvent. Subsequently, the capability of the conductor-like screening model for real system (COSMO-RS) to predict the excess enthalpies of the binary system of ionic liquid and molecular solvent was further evaluated. In general, a good agreement between experimental excess enthalpies and COSMO-RS prediction was obtained. In addition, the COSMO-RS was able to depict and screen the type of molecular interaction that governs the excess enthalpies of ionic liquid and molecular solvent. Thus, COSMO-RS proved very useful as an a priori method that could be used as a tool in the selection or design of a suitable ionic liquid candidate for a certain task and application before extensive experimental measurement.
71 citations
TL;DR: In this paper, experimental data was obtained on ion exchange equilibrium for the binary systems Ni2+/Na+ and Zn2+ /Na+ using Amberlite IR 120 resin in closed batch system at 25°C and starting pH of 4.5.
57 citations
TL;DR: In this article, new sapphire and diamond anvil cell experiments were conducted in this binary system to constrain the stability of the CO2 hydrates and H2O-ice VI at CO2 saturation in the 250 −330 K and 0 −1.7 GPa temperature and pressure ranges.
55 citations
TL;DR: In this article, a binary Mg-Al system using multiphase diffusion couples assembled between pure Mg and pure Al at 380, 400 and 420°C was studied and the activation energies for the growth of β and γ phases in the temperature range of 380-420°C were found to be 37.3±4.1 and 187.7±1.9
Abstract: Binary interdiffusion data as functions of composition in the Mg-Al system are essential in modeling kinetics of phase transformations in multicomponent Mg and Al alloys. Interdiffusion and phase growth kinetics were studied in the binary Mg-Al system using multiphase diffusion couples assembled between pure Mg and pure Al at 380, 400 and 420 °C. Two phases, Al3Mg2 (β) and Mg17Al12 (γ) were formed between Al and Mg at the three temperatures studied. Both β and γ phases were observed to follow parabolic growth with time, which suggests that the growth of the two phases is controlled by bulk diffusion mechanisms. The activation energies for the growth of β and γ phases in the temperature range of 380-420 °C were found to be 37.3 ± 4.1 and 187.7 ± 1.9 kJ/mol, respectively. The interdiffusion coefficients were evaluated as functions of compositions in various phases at the three temperatures studied, which were further utilized for evaluating the activation energies and frequency factors for interdiffusion in each phase. The activation energy for interdiffusion in FCC-Al is found to increase with increasing Mg-content whereas the activation energies for interdiffusion in HCP-Mg and γ phases do not vary significantly with composition.
54 citations
TL;DR: In this paper, a comparative and competitive adsorption study was conducted in single and binary systems using a montmorillonite-iron oxide composite (MIOC) was prepared to assess its effectiveness in the removal of Cs+ and Sr2+ from aqueous solution.
Abstract: A montmorillonite–iron oxide composite (MIOC) was prepared to assess its effectiveness in the removal of Cs+ and Sr2+ from aqueous solution. A comparative and competitive adsorption study was conducted in single and binary systems. Used materials have been characterized by X-ray diffraction (XRD) and Infrared spectroscopy. Adsorption of Cs+ and Sr2+ as a function of contact time and pH was investigated, adsorption data of single metal solutions were well fitted to the Freundlich–Langmuir isotherm models. Equilibrium isotherms for the binary removal of Cs+ and Sr2+ by MIOC have been analyzed by using non modified and extended Langmuir models with a satisfactory R
2 values. Neutral solution pH was found to be favorable for both single and binary systems. The adsorption model analysis revealed that MIOC was more selective for Sr than Cs. The maximum adsorption capacities for individual Cs+ and Sr2+ solutions were 52.6 and 55.5 mg g−1, respectively. While the maximum uptakes in the binary system were 41.6 and 47.6 mg g−1 for Cs+ and Sr2+, respectively. Column adsorption experiments were carried out at room temperature under the effect of various operating parameters such as bed depth, initial cation concentration and flow rate, Breakthrough curves were well fitted to the Thomas model. Desorption experiments were also conducted to assess the possibility for the reuse of adsorbent and the recovery of cations.
50 citations
TL;DR: In this paper, the effect of pH and contact time on the adsorption of W and Mo using macroporous weak base resin D301 was investigated at the optimal pH-value in both individual and binary systems.
50 citations
TL;DR: In this paper, the effects of dynamical evolution in dense clusters on the companion mass ratio distribution (CMRD) of binary stars are explored, and the shape of the observed binary CMRD is an outcome of the star formation process, and should be measured in preference to the distributions of orbital parameters such as the semi-major axis distribution.
Abstract: We explore the effects of dynamical evolution in dense clusters on the companion mass ratio distribution (CMRD) of binary stars. Binary systems are destroyed by interactions with other stars in the cluster, lowering the total binary fraction and significantly altering the initial semi-major axis distribution. However, the shape of the CMRD is unaffected by dynamics; an equal number of systems with high mass ratios are destroyed compared to systems with low mass ratios. We might expect a weak dependence of the survivability of a binary on its mass ratio because its binding energy is proportional to both the primary and secondary mass components of the system. However, binaries are broken up by interactions in which the perturbing star has a significantly higher energy (by a factor of >10, depending on the particular binary properties) than the binding energy of the binary, or through multiple interactions in the cluster. We therefore suggest that the shape of the observed binary CMRD is an outcome of the star formation process, and should be measured in preference to the distributions of orbital parameters, such as the semi-major axis distribution.
48 citations
TL;DR: In this paper, the primary component of a 2.7 AU ultracool dwarf binary system (L0+L1.5) was found to have a rotation period of 3.32 ± 0.15 h from 2MASS J0746+20A.
Abstract: Studies of solar-type binaries have found coplanarity between the equatorial and orbital planes of systems with <40 AU separation. By comparison, the alignment of the equatorial and orbital axes in the substellar regime, and the associated implications for formation theory, are relatively poorly constrained. Here we present the discovery of the rotation period of 3.32 ± 0.15 h from 2MASS J0746+20A – the primary component of a tight (2.7 AU) ultracool dwarf binary system (L0+L1.5). The newly discovered period, together with the established period via radio observations of the other component, and the well constrained orbital parameters and rotational velocity measurements, allow us to infer alignment of the equatorial planes of both components with the orbital plane of the system to within 10 degrees. This result suggests that solar-type binary formation mechanisms may extend down into the brown dwarf mass range, and we consider a number of formation theories that may be applicable in this case. This is the first such observational result in the very low mass binary regime. In addition, the detected period of 3.32 ± 0.15 h implies that the reported radio period of 2.07 ± 0.002 h is associated with the secondary star, not the primary, as was previously claimed. This in turn refutes the claimed radius of 0.78 ± 0.1 R_J for 2MASS J0746+20A, which we demonstrate to be 0.99 ± 0.03 R_J.
TL;DR: In this article, the isothermal VLE values for the system of {1,1,2,2-Tetrafluoroethane (R134) + trans-1,3, 3,3-tetrabluoropropene (R1234ze(E))} at four temperatures from (258.150 to 288.150) K were measured with an apparatus based on the static-analytic method.
TL;DR: In this paper, the effects of a microwave field on the VLE for binary mixtures were investigated and it was concluded that the ethanol can be vaporized selectively because the rate of microwave energy absorption of ethanol is higher than the heat transfer from ethanol to benzene.
TL;DR: In this paper, the authors measured a binary system of {1,1-difluoroethene (R152a) + trans-1,3,3-3-tetrafluoropropene (R1234ze (E))} at temperatures ranging from 258.150 to 288.150
TL;DR: In this article, the authors measured the solubility and liquid saturated properties (density and viscosity) when a liquid hydrocarbon (decane, tetradecane and their mixtures) was saturated with CO2.
TL;DR: In this article, the phase behavior of the H2S−CO2 binary system has been investigated using magnetic capillary samplers, with uncertainties within ± 0.02 K, ±0.002 MPa, and 0.006 MPa for molar compositions.
TL;DR: In this article, the Soave-Redlich-Kwong (SRK) and Peng-Robinson (PR) equations of state (EOS) were used to determine liquid phase composition and liquid saturated properties (density and viscosity) when a liquid hydrocarbon was saturated with carbon dioxide.
TL;DR: In this paper, the authors measured the density, viscosity, and refractive indices of tricyclo[5.2.1]decane at temperatures T = (293.15 to 318.15 K) and pressure p = 0.02.
Abstract: Densities, viscosities, and refractive indices have been measured for the binary system of tricyclo[5.2.1.02.6]decane with cyclohexane, methylcyclohexane, ethylcyclohexane, butylcyclohexane, or 1,2,4-trimethylcyclohexane at temperatures T = (293.15 to 318.15 K) and pressure p = 0.1 MPa. The excess molar volumes (VmE), the viscosity deviations (Δη), and the refractive index deviations (ΔnD) are then calculated. The changes of VmE and Δη with the composition are fitted to the Redlich–Kister equation. The values of density, viscosity, and refractive index increase continuously with the increase of mole fraction of tricyclo[5.2.1.02.6]decane and decrease with the rise of temperature. The VmE and Δη are all negative over the whole composition range for these five binary systems. The changes of VmE and Δη are discussed from the points of view of molecular interactions in the binary systems.
TL;DR: In this paper, the authors show that the commonly adapted approach to minimize the effects of binaries on an observed sample by excluding systems detected as binaries through radial velocity campaigns can be counterproductive, as it substantially enhances the relative incidence of mergers and binary products in the non radial velocity variable sample.
Abstract: Because the majority of massive stars are born as members of close binary systems, populations of massive main-sequence stars contain stellar mergers and products of binary mass transfer. We simulate populations of massive stars accounting for all major binary evolution effects based on the most recent binary parameter statistics and extensively evaluate the effect of model uncertainties.
Assuming constant star formation, we find that $8^{+9}_{-4}\,\%$ of a sample of early type stars to be the product of a merger resulting from a close binary system. In total we find that $30^{+10}_{-15}\,\%$ of massive main-sequence stars are the product of binary interaction.
We show that the commonly adapted approach to minimize the effects of binaries on an observed sample by excluding systems detected as binaries through radial velocity campaigns can be counterproductive. Systems with significant radial velocity variations are mostly pre-interaction systems. Excluding them substantially enhances the relative incidence of mergers and binary products in the non radial velocity variable sample.
This poses a challenge for testing single stellar evolutionary models. It also raises the question of whether certain peculiar classes of stars, such as magnetic O-stars, are the result of binary interaction and it emphasizes the need to further study the effect of binarity on the diagnostics that are used to derive the fundamental properties (star-formation history, initial mass function, mass to light ratio) of stellar populations nearby and at high redshift.
TL;DR: In this article, an amino acid based ionic liquid [Bmim][Asp], 1-butyl-3-methylimidazolium aspartate, and a binary mixture system composed of methanol and amino acid were synthesized and prepared, respectively.
Abstract: An amino acid based ionic liquid [Bmim][Asp], 1-butyl-3-methylimidazolium aspartate, and a binary mixture system composed of [Bmim][Asp] and methanol were synthesized and prepared, respectively. The density, surface tension, and electrical conductivity of the pure IL and the binary system were measured or estimated by the extrapolation method at different temperatures. The physicochemical properties of the IL or the binary system like the molecular volume, standard molar entropy, lattice energy, parachor, speed of sound, molar enthalpy of vaporization, interstice volume, thermal expansion coefficient, excess volume, and so forth were estimated by empirical and semiempirical equations. The glass transition temperature was determined by the differential scanning calorimetry (DSC). The status of intermolecular interaction based on the excess volume change of the IL mixture was discussed at 298.15 K. By Vogel–Fulcher–Tamman (VFT) and Castell–Amis (CA) equations, the relationship between the electrical conduct...
TL;DR: In this article, the absolute parameters of PY Vir were derived using spectroscopic and photometric solutions, and the O -C diagram of the binary star was investigated by combining new determined times of minimum light with others published in the literature.
Abstract: Complete CCD photometric light curves in BV(RI)(c) bands obtained in 2012 for the short-period close binary system PY Virginis are presented. A new photometric analysis with the Wilson-Van Hamme code shows that PY Vir is an A-type marginal contact binary system. The absolute parameters of PY Vir are derived using spectroscopic and photometric solutions. Combining new determined times of minimum light with others published in the literature, the O - C diagram of the binary star is investigated. A periodic variation, with a period of 5.22(+/- 0.05) years and an amplitude of 0.0075(+/- 0.0004) days, was discovered. Since the spectrum of a third component has been detected by Rucinski et al., we consider this cyclic period oscillation to be the result of the light-time effect due to the presence of a third body. This third component may also be a binary itself. Therefore, PY Vir should be a quadruple system composed of two cool-type binary systems. This system is a good astrophysical laboratory to study the formation and evolution of close binaries and multiple systems.
TL;DR: The solubility of naringenin in the binary system of ethanol and water was measured by an ultraviolet spectrophotometer at 288 nm (the maximum absorption wavelength) from (283.15 to 323.15) K as mentioned in this paper.
Abstract: The solubility of naringenin in the binary system of ethanol and water was measured by an ultraviolet spectrophotometer at 288 nm (the maximum absorption wavelength) from (283.15 to 323.15) K. The increasing solubility was correlated with the increasing temperature and the increasing mole fraction of ethanol in the solvent system. In the investigated experimental temperature range, the course of naringenin dissolving in the binary system was endothermic. The calculated solubility of naringenin showed good consistency with the experimental values.
TL;DR: In this article, an embedded atom method (EAM) interatomic potential is constructed to reproduce the main topological features of the experimental equilibrium phase diagram of the Cu-Nb system in both solid and liquid states.
Abstract: An embedded atom method (EAM) interatomic potential is constructed to reproduce the main topological features of the experimental equilibrium phase diagram of the Cu–Nb system in both solid and liquid states. The potential is fitted to composition-dependent enthalpies of mixing for bcc and fcc random solid solutions obtained from first-principles calculations at 0 K. Compared with two other EAM Cu–Nb potentials in the literature, the phase diagram of the current potential shows better agreement with the experimental phase diagram. Our potential predicts that the Cu–Nb liquid phase at equilibrium is compositionally patterned over lengths of about 2.3 nm. The newly constructed potential may be used to study the effect of liquid thermodynamics and structure on properties of binary systems, such as radiation-induced mixing.
TL;DR: Considering the difficulties in explaining the experimental findings based on the traditional model of SmE structure, a new model, lamellar with two types of sublayers consisting of aromatic core and alkyl chain moieties, is proposed.
Abstract: Thermodynamic and diffraction analyses were performed to establish the phase diagram for a binary system between 4-n-nonyl-4′-isothiocyanatobiphenyl (9TCB) and n-nonane. The swollen SmE structure i...
TL;DR: In this article, the authors analyzed the changes in the observed minus calculated (O-C) diagram in HS 0705+6700, a short-period (2.3 h) eclipsing binary that consists of a very hot subdwarf B-type (sdB) star and a very cool fully convective red dwarf.
Abstract: By using 78 newly determined timings of light minima together with those collected from the literature, we analysed the changes in the observed minus calculated (O-C) diagram in HS 0705+6700, a short-period (2.3 h) eclipsing binary that consists of a very hot subdwarf B-type (sdB) star and a very cool fully convective red dwarf. We confirmed the cyclic variation in the O-C and refined the parameters of the circumbinary brown dwarf (reported to orbit the binary system in 2009) by analysing the changes for the light travel time effect that arises from the gravitational influence of the third body. Our results indicate the lower mass limit of the third body to be M-3 sin i(') = 33.7(+/- 1.6) M-Jup. This companion would be a brown dwarf if its orbital inclination is larger than 27 degrees.7 and it is orbiting the central eclipsing binary with an eccentricity e similar to 0.2 at a separation of about 3.7(+/- 0.1) au.
TL;DR: In this paper, a survey of the available data of the experimental surface tension data for refrigerant binary systems is presented, and a new equation for the prediction of the surface tension of binary systems based on the Corresponding States Principle theory is proposed.
Abstract: This work presents a literature survey of the available data of the experimental surface tension data for refrigerant binary systems. The experimental data were collected for the following binary systems: R32-R227ea, R32-R125, R32-R134a, R290-R32, R125-R152a, R290-R152a, R290-R600a, RE170-R290, R143a-R134a, R125-R134a, R125-R143a, R134a-R152a and R143a + R227ea. Two recently proposed equations for the prediction of the surface tension of pure fluids were evaluated for their abilities to predict the surface tension of binary systems. A new equation for the prediction of the surface tension of refrigerant binary systems based on the Corresponding States Principle theory is proposed.
TL;DR: In this paper, the authors presented the first calculations of mass transfer via RLOF for a binary system with a significant eccentricity using a new binary stellar evolution code, focusing on a 1.50+1.40 M ⊙ main sequence binary with an eccentricity of 0.25, and an orbital period of P orb ǫ ≥ 0.7 d.
Abstract: Context. Studies of interacting binary systems typically assume that tidal forces have circularized the orbit by the time Roche lobe overflow (RLOF) commences. However, recent observations of ellipsoidal variables have challenged this assumption.Aims. We present the first calculations of mass transfer via RLOF for a binary system with a significant eccentricity using our new binary stellar evolution code. The study focuses on a 1.50+1.40 M ⊙ main sequence binary with an eccentricity of 0.25, and an orbital period of P orb ≈ 0.7 d. The reaction of the stellar components due to mass transfer is analysed, and the evolution of mass transfer during the periastron passage is compared to recent smooth particle hydrodynamics (SPH) simulations. The impact of asynchronism and non-zero eccentricity on the Roche lobe radius, and the effects of tidal and rotational deformation on the stars’ structures, are also investigated.Methods. Calculations were performed using the state-of-the-art binary evolution code BINSTAR, which calculates simultaneously the structure of the two stars and the evolution of the orbital parameters.Results. The evolution of the mass transfer rate during an orbit has a Gaussian-like shape, with a maximum at periastron, in qualitative agreement with SPH simulations. The Roche lobe radius is modified by the donor star’s spin and the orbital eccentricity. This has a significant impact on both the duration and the rate of mass transfer. We find that below some critical rotation rate, mass transfer never occurs, while above some threshold, mass is transferred over the entire orbit. Tidal and rotational deformation of the donor star causes it to become over-sized, enhancing the mass transfer rate further by up to about a factor of ten, leading to non-conservative mass transfer. The modulation of the mass transfer rate with orbital phase produces short-term variability in the surface luminosity and radius of each star. The longer-term behaviour shows, in accordance with studies of circular systems with radiative stars, that the donor becomes ever small and under-luminous, while the converse is the case for the accretor.
TL;DR: The solubility of daidzein in the binary system of ethanol and water was measured by UV spectrophotometric method from 288.2 to 328.2 K as mentioned in this paper.
TL;DR: In this paper, a comparison of performances was made by using the criterion of average absolute deviations in boiling point and in vapor phase composition, and the results showed that the NRTL model yielded a good prediction for the quaternary system from the parameters of the correlated binary systems.
TL;DR: In this article, the phase diagram of the n-octadecane+lauryl alcohol binary system presented a eutectic behavior for the solid-liquid equilibrium line, and the corresponding mole fraction of n-OctaCane in the point is 0.257.