Showing papers on "Binary system published in 2012"

Reversible Insertion of Sodium in Tin

Abstract: The electrochemistry and the structural changes that occur during sodium insertion and removal from tin are studied by in-situ X-ray diffraction at 30°C. The Sn vs. Na voltage curve has four distinct plateaus, corresponding to four two-phase regions during sodiation, and indicating that four Na-Sn binary alloys are formed. The alloy formed at full sodiation was found to be Na15Si4, as expected from the Na-Sn binary system at equilibrium. The three intermediate Na-Sn phases that form during sodiation have X-ray diffraction patterns that do not correspond to any known equilibrium phase of Na-Sn. More work is needed to characterize these new binary Na-Sn phases.

A Review of the Relationship between Viscosity and the Structure of Calcium‐Silicate‐Based Slags in Ironmaking

Abstract: This review focuses on elucidating the viscosity of ironmaking slags and the effect of various components in the multi-component calcium-silicate-based slag system on the viscosity. Using various widely used spectroscopic techniques including Fourier transform infrared (FTIR), Raman, X-ray photoelectron spectroscopy (XPS), and nuclear magnetic resonance (NMR), the viscous behavior and the slag structure of this system were correlated. In particular, the review begins with an introduction to the viscous behavior of binary silicate systems and an identification of the intricate details of the slag structure. Using the binary system as a basis, the compounded effect of typical ironmaking slag components such as Al2O3, MgO, alkali oxides, and TiO2 on the viscosity is introduced through expansion to a quinary slag system. Using a combination of the aforementioned spectroscopic methods, the meticulous details of the slag structure were ascertained, and the depolymerization or polymerization mechanisms of the silicate and alumino-silicate structures were subsequently identified. This review also compares well-known viscosity prediction models with experimentally measured values and identifies potential fields of research in the ironmaking industry associated with slag viscosities.

Eu2+ luminescence from 5 different crystallographic sites in a novel red phosphor, Ca15Si20O10N30:Eu2+

Abstract: Because it is impossible to realize broadband-type, red-light-emitting phosphors in the oxide composition pool, both pure nitrides and oxynitrides have been considered as potential red phosphors for use in light emitting diode (LED) applications. However, only a limited number of red phosphors have been discovered. For instance, only a few red phosphors such as CaAlSiN3:Eu2+, Sr2Si5N8:Eu2+, and their variations are worthy of notice. We examined the CaO–Si3N4 binary system to discover novel oxynitride red phosphors. We finally identified a novel oxynitride phosphor, Ca15Si20O10N30:Eu2+, with a cubic structure in the Pa space group. This phosphor showed a broadband-type, red-light emission at UV and blue-light excitations. A continuous-wave-excited, steady-state photoluminescence (PL) and a pulsed-laser-excited, time-resolved PL for the discovered phosphor were investigated in conjunction with a structural analysis of Ca15Si20O10N30:Eu2+. The variation in decay rate with respect to the detection wavelength was examined in detail, and the energy transfer among activators located at 5 different crystallographic sites proved to be responsible.

Experimental and thermodynamic studies of the Fe-Si binary system

Abstract: Phase equilibria in the Fe–Si binary system were investigated experimentally and thermodynamic assessment was carried out. The αFe (A2) + α"Fe3Si (D03) two-phase microstructures at 600°C and 650°C were obtained, whose grain sizes were sufficiently coarsened to be analyzed by FE-EPMA with a spatial resolution below 0.5 μm under the condition of 6 kV accelerating voltage. α'FeSi (B2) + α"Fe3Si (D03) two-phase equilibria above 700°C were detected for the first time and equilibrium compositions were determined by the diffusion couple method. The horn-shaped two-phase miscibility gap extends from the low temperature αFe + α"Fe3Si equilibrium along the B2/D03 second-order transition boundary and closes below 1000°C. Four-sublattice split compound energy formalism was applied to calculate the Gibbs energy of the bcc phases, A2(αFe), B2(α'FeSi) and D03(α"Fe3Si), and the thermodynamic parameters in the Fe–Si binary system were evaluated. Equilibrium relations in the binary system were well reproduced, especially the effect of the B2 and D03 ordering on the liquidus and solidus curves and the miscibility gap between bcc phases. Optimized thermodynamic parameters as well as the experimental results are expected to be helpful for developing higher multi-component systems for practical steels.

Phase Equilibria of CO2 + n-Alkane Binary Systems in Wide Ranges of Conditions: Development of Predictive Correlations Based on Cubic Mixing Rules

Abstract: The phase equilibria of binary CO2 + n-alkane mixtures have been studied by an important number of authors, both experimentally and using different types of thermodynamic models. Modeling studies of the phase behavior of such highly nonideal systems have generally achieved only partially accurate results in the correlation of phase equilibrium data when considering wide ranges of temperature, pressure, and n-alkane molecular weight. In this study, a predictive correlation for the phase behavior of CO2 + n-alkane systems, based on a three-parameter cubic equation of state (EOS), that is, the RK-PR EOS, coupled to cubic mixing rules (CMRs), is developed and tested. CMRs have been shown to be capable of an accurate correlation of the phase equilibria asymmetric CO2 + n-alkane binary systems, in wide ranges of temperature and pressure, when using system-specific interaction parameters. For developing the predictive correlation a critical review of published experimental data for the series was carried out, co...

Asymmetric supernova in hierarchical multiple star systems and application to J1903+0327

Abstract: We develop a method to analyse the effect of an asymmetric supernova on hierarchical multiple star systems and present analytical formulas to calculate orbital parameters for surviving binaries or hierarchical triples and runaway velocities for their dissociating equivalents. The effect of an asymmetric supernova on the orbital parameters of a binary system has been studied to a great extent, but this effect on higher multiplicity hierarchical systems has not been explored before. With our method, the supernova effect can be computed by reducing the hierarchical multiple to an effective binary by means of recursively replacing the inner binary by an effective star at the centre of mass of that binary. We apply our method to a hierarchical triple system similar to the progenitor of PSR J1903+0327 suggested by Portegies Zwart et al. We confirm their earlier finding that PSR J1903+0327 could have evolved from a hierarchical triple that became unstable and ejected the secondary star of the inner binary. Furthermore, if such a system did evolve via this mechanism the most probable configuration would be a small supernova kick velocity, an inner binary with a large semi-major axis, and the fraction of mass accreted on to the neutron star to the mass lost by the secondary most likely be between 0.35 and 0.5.

Kinetics and equilibrium studies for the removal of heavy metals in both single and binary systems using hydroxyapatite

Abstract: Removal of heavy metals is very important with respect to environmental considerations. This study investigated the sorption of copper (Cu) and zinc (Zn) in single and binary aqueous systems onto laboratory prepared hydroxyapatite (HA) surfaces. Batch experiments were carried out using synthetic HA at 30 °C. Parameters that influence the adsorption such as contact time, adsorbent dosage and pH of solution were investigated. The maximum adsorption was found at contact time of 12 and 9 h, HA dosage of 0.4 and 0.7 g/l and pH of 6 and 8 for Cu and Zn, respectively, in single system. Adsorption kinetics data were analyzed using the pseudofirst-, pseudosecond-order and intraparticle diffusion models. The results indicated that the adsorption kinetic data were best described by pseudosecond-order model. Langmuir and Freundlich isotherm models were applied to analyze adsorption data, and Langmuir isotherm was found to be applicable to this adsorption system, in terms of relatively high regression values. The removal capacity of HA was found to be 125 mg of Cu/g, 30.3 mg of Zn/g in single system and 50 mg of Cu/g, 15.16 mg of Zn/g in binary system. The results indicated that the HA used in this work proved to be effective material for removing Cu and Zn from aqueous solutions.

Thermodynamic Properties of the Water + 1-(2-Hydroxylethyl)-3-methylimidazolium Chloride System

Abstract: In this paper, the water + 1-(2-hydroxyethyl)-3-methylimidazolium chloride ([HOEtMIM]Cl) binary system was studied as a novel alternative working pair of the absorption heat pump cycle. Thermodynamic properties of the system including vapor pressure, density, and heat capacity were measured in the mole fraction range from 0.0122 to 0.3071 of [HOEtMIM]Cl. The vapor pressures of the binary system were determined by the boiling-point method in the pressure from (2.82 to 102.29) kPa and correlated by the nonrandom two-liquid (NRTL) model. The densities and heat capacities were measured in the temperature range from (298.15 to 323.15) K and (298.15 to 358.15) K, respectively, and correlated by the polynomial equations on temperature and concentration. The average relative deviations (ARDs) between the experimental and the calculated values of vapor pressure, density, and heat capacity are 1.42 %, 0.09 %, and 0.38 %, respectively.

9 Sagittarii: uncovering an O-type spectroscopic binary with an 8.6 year period

Abstract: Context. The O-type object 9 Sgr is a well-known synchrotron radio emitter. This feature is usually attributed to colliding-wind binary systems, but 9 Sgr was long considered a single star. Aims. We have conducted a long-term spectroscopic monitoring of this star to investigate its multiplicity and search for evidence for wind-wind interactions. Methods. Radial velocities are determined and analysed using various period search methods. Spectral disentangling is applied to separate the spectra of the components of the binary system. Results. We derive the first ever orbital solution of 9 Sgr. The system is found to consist of an O3.5 V((f + )) primary and an O5-5.5 V((f)) secondary moving around each other on a highly eccentric (e = 0.7), 8.6 year orbit. The spectra reveal no variable emission lines that could be formed in the wind interaction zone in agreement with the expected properties of the interaction in such aw ide system. Conclusions. Our results provide further support to the paradigm of synchrotron radio emission from early-type stars being a manifestation of interacting winds in a binary system.

Ab initio calculations and thermodynamic modeling for the Fe–Mn–Nb system

Abstract: The Fe–Nb and Mn–Nb systems have been thermodynamically investigated within the CALPHAD approach by combining available experimental data and the data from our ab initio calculations. Possible nonmagnetic (NM), ferromagnetic (FM) and antiferromagnetic (AFM) ordering for the end-members of the intermetallic compounds Laves C14 and μ were treated during ab initio calculations. It turns out that the local magnetic moment depends on the lattice site. The energetically most stable states of C14 at the stoichiometric compositions NbFe 2 and NbMn 2 exhibit the FM and NM ordering, respectively. The FM ordering can lower the total energies for most of the end members of μ in the Fe–Nb system. The energy of formation for the “hypothetical” end-members of μ, due to the sublattice model used for modeling the ternary solubility, was also calculated by ab initio and incorporated into the modeling of the phase. μ is predicted to be marginally stable in the Mn–Nb binary system. Compared to the conventional treatment for the end-members of C14, the introduction of physically based parameters from ab initio calculations makes the thermodynamic optimization process simpler, more effective and more reliable in the Mn–Nb binary system. The obtained thermodynamic parameters for Fe–Nb and Mn–Nb systems can describe the reliable experimental data well. The thermodynamic description for the ternary Fe–Mn–Nb system is then extrapolated for the first time from the three binary edges and the data from our ab initio calculations. Several isothermal sections, the liquidus projection and the reaction scheme have been predicted accordingly.

9 Sgr: uncovering an O-type spectroscopic binary with an 8.6 year period

Abstract: The O-type object 9 Sgr is a well-known synchrotron radio emitter. This feature is usually attributed to colliding-wind binary systems, but 9 Sgr was long considered a single star. We have conducted a long-term spectroscopic monitoring of this star to investigate its multiplicity and search for evidence for wind-wind interactions. Radial velocities are determined and analysed using various period search methods. Spectral disentangling is applied to separate the spectra of the components of the binary system. We derive the first ever orbital solution of 9 Sgr. The system is found to consist of an O3.5 V((f+)) primary and an O5- 5.5 V((f)) secondary moving around each other on a highly eccentric (e = 0.7), 8.6 year orbit. The spectra reveal no variable emission lines that could be formed in the wind interaction zone in agreement with the expected properties of the interaction in such a wide system. Our results provide further support to the paradigm of synchrotron radio emission from early-type stars being a manifestation of interacting winds in a binary system.

Glass Formation in LaO3/2–TiO2 Binary System by Containerless Processing

Abstract: Using containerless processing with an aerodynamic levitation furnace, LaO3/2–TiO2 binary glasses were synthesized in bulk form. Glass-forming region was found in the vicinity of eutectic point, which is approximately 29.5% LaO3/2 and 70.5% TiO2 in molar ratio. The glass transition temperature Tg and the crystallization onset temperature Tx of the obtained glasses were determined by differential scanning calorimetry. The thermal stability was evaluated by ΔT (=Tx − Tg). Our experimental results were compared with phase diagram of the LaO3/2–TiO2 binary system. Glass compositions with highest ΔT corresponded to single-phase compound of La4Ti9O24 and the eutectic point.

Separation of N2O and CO2 using Room-Temperature Ionic Liquid [bmim][Ac]

Abstract: We have developed a ternary equation of state (EOS) model for the N2O/CO2/1-butyl-3-methylimidazolium acetate ([bmim][Ac]) system in order to understand the separation of N2O and CO2 using room-temperature ionic liquids (RTILs). The present model is based on a generic RK (Redlich-Kwong) EOS, with empirical interaction parameters for each binary system. The interaction parameters have been determined using our measured VLE (vapor-liquid-equilibrium) data for N2O/[bmim][Ac] and literature data for CO2/[bmim][Ac] and N2O/CO2. The binary EOS model for the N2O/[bmim][Ac] system correctly predicted the liquid-liquid phase separation found in VLLE experiments. The validity of the ternary EOS model has been checked by conducting VLE experiments for the N2O/CO2/[bmim][Ac] system over a temperature range from 296 to 313 K. With this EOS model, solubility (VLE) behavior has been calculated for various (T, P, and feed compositions) conditions. Over a range of N2O/CO2 feed ratios, the N2O/CO2 gas selectivity [α N 2 O/...

Thermophysical properties of binary mixtures {1-methyl-3-pentylimidazolium tetrafluoroborate + polyethylene glycol methyl ether}

Abstract: Few reports are available on the thermophysical properties of ionic liquid (IL) and the polymeric (or oligomeric) solution binary system. In this study, the densities, viscosities, and refractive indices were determined for IL mixtures formed by 1-methyl-3-pentylimidazolium tetrafluoroborate [MPI][BF4] with polyethylene glycol methyl ether (MPEG) [Mw = 350] over the mole fraction ranging from 0.1 to 0.9 and temperatures from 293.15 to 353.15 K at intervals of 5 K and atmospheric pressure. The temperature dependence of density and dynamic viscosity for both neat [MPI][BF4] and its binary mixtures were described by an empirical linear equation and by the Vogel–Tammann–Fulcher (VTF) equation, respectively. Excess molar volumes, viscosity deviations, and refractive index deviations were calculated from the experimental data and fitted to a Redlich–Kister polynomial function. The excess molar volume and viscosity deviations for the binary system were negative over both the composition and temperature ranges, whereas the refractive index deviations were always positive. The results have been interpreted in terms of ion–dipole interactions and the structural factors of the IL and MPEG molecular liquids.

Mesomorphism of Binary Systems of Nonmesogenic Compounds

Abstract: Three binary systems, each consisting of two nonmesogenic compounds, viz. p-tolual-p-phenetidine (M.P. 108.5°C) [A] as the common component, and Methyl p-(p′-n-butyloxy benzoyloxy) benzoate (M.P. 119.0°C) [B1], Ethyl-p-(p′-n-butyloxy benzoyloxy) benzoate (M.P. 94.0°C) [B2], and n-Butyl p-(p′-n-butyloxy benzoyloxy) benzoate (M.P. 130.0°C) [B3] as the second component, respectively, are studied with a view to understand the effect of terminal groups on nematic and/or smectic mesomorphism. Latent transition temperatures (LTT) of the constituent components A, B1, B2, and B3 were determined by extrapolation. Binary system (A + B1) induces a nematogenic mesophase while binary systems (A + B2) and (A + B3) both induce a smectic mesophase in addition to a nematic mesophase. Phase diagrams of the binary systems under investigation are plotted for the mole percent of component (A) versus the transition temperatures of each binary system as determined from polarizing optical microscopy. The texture of the nematic me...

Experimental Investigation and Thermodynamic Calculation of the Phase Equilibria in the Al-Bi-Sn Ternary System

Abstract: This work first deals with the experimental investigation and thermodynamic calculation in the Al-Bi-Sn ternary system. The phase equilibria at 400 and 500 °C in the Al-Bi-Sn ternary system have been experimentally determined by electron probe microanalysis (EPMA) on the equilibrated alloys. Based on the experimental data determined in the present work, the phase equilibria in the Al-Bi-Sn ternary system have been thermodynamically assessed by using the CALPHAD (CALculation of PHAse Diagrams) method, and a consistent set of thermodynamic parameters leading to reasonable agreement between the calculated results and experimental data was obtained. The additions of Sn can effectively reduce the stable liquid miscibility gap in the Al-Bi binary system and gradually decrease its critical temperature. And the additions of Bi can significantly stabilize the metastable liquid miscibility gap in the Al-Sn binary system. This is shown by an initial decrease in critical temperature with increasing Bi additions.

The Rossiter?McLaughlin Effect for Exomoons or Binary Planets

Abstract: In this paper, we study possible signatures of binary planets or exomoons on the Rossiter-McLaughlin (R-M) effect. Our analyses show that the R-M effect for a binary planet or an exomoon during its complete transit phase can be divided into two parts. The first is the conventional one similar to the R-M effect from the transit of a single planet, of which the mass and the projected area are the combinations of the binary components; the second is caused by the orbital rotation of the binary components, which may add a sine- or linear-mode deviation to the stellar radial velocity curve. We find that the latter effect can be up to several ten m s{sup -1}. Our numerical simulations as well as analyses illustrate that the distribution and dispersion of the latter effects obtained from multiple transit events can be used to constrain the dynamical configuration of the binary planet, such as how the inner orbit of the binary planet is inclined to its orbit rotating around the central star. We find that the signatures caused by the orbital rotation of the binary components are more likely to be revealed if the two components of a binary planet have differentmore » masses and mass densities, especially if the heavy one has a high mass density and the light one has a low density. Similar signatures on the R-M effect may also be revealed in a hierarchical triple star system containing a dark compact binary and a tertiary star.« less

2007 ty430: a cold classical kuiper belt type binary in the plutino population

Abstract: Kuiper Belt object 2007 TY430 is the first wide, equal-sized, binary known in the 3:2 mean motion resonance with Neptune. The two components have a maximum separation of about 1 arcsec and are on average less than 0.1 mag different in apparent magnitude with identical ultra-red colors (g – i = 1.49 ± 0.01 mag). Using nearly monthly observations of 2007 TY430 from 2007 to 2011, the orbit of the mutual components was found to have a period of 961.2 ± 4.6 days with a semi-major axis of 21000 ± 160 km and eccentricity of 0.1529 ± 0.0028. The inclination with respect to the ecliptic is 15.68 ± 0.22 deg and extensive observations have allowed the mirror orbit to be eliminated as a possibility. The total mass for the binary system was found to be 7.90 ± 0.21 × 1017 kg. Equal-sized, wide binaries and ultra-red colors are common in the low-inclination "cold" classical part of the Kuiper Belt and likely formed through some sort of three-body interactions within a much denser Kuiper Belt. To date 2007 TY430 is the only ultra-red, equal-sized binary known outside of the classical Kuiper Belt population. Numerical simulations suggest 2007 TY430 is moderately unstable in the outer part of the 3:2 resonance and thus 2007 TY430 is likely an escaped "cold" classical object that later got trapped in the 3:2 resonance. Similar to the known equal-sized, wide binaries in the cold classical population, the binary 2007 TY430 requires a high albedo and very low density structure to obtain the total mass found for the pair. For a realistic minimum density of 0.5 g cm–3 the albedo of 2007 TY430 would be greater than 0.17. For reasonable densities, the radii of either component should be less than 60 km, and thus the relatively low eccentricity of the binary is interesting since no tides should be operating on the bodies at their large distances from each other. The low prograde inclination of the binary also makes it unlikely that the Kozai mechanism could have altered the orbit, making the 2007 TY430 binary orbit likely one of the few relatively unaltered primordial binary orbits known. Under some binary formation models, the low-inclination prograde orbit of the 2007 TY430 binary indicates formation within a relatively high velocity regime in the Kuiper Belt.

Isotherm, Kinetic, and Thermodynamic of Cationic Dye Removal from Binary System by Feldspar

Abstract: In this paper, the isotherm, kinetic, and thermodynamic of cationic dye removal onto inorganic adsorbent (Feldspar) were investigated in single and binary systems. Basic Red 18 (BR18) and Basic Blue 41 (BB41) were used as cationic dyes. The characterization of the Feldspar was carried out using X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) techniques. The effect of operational parameters such as adsorbent dosage, initial dye concentration, pH, ionic strength, and temperature on dye removal was studied. It was found that the adsorption of BR18 and BB41 onto Feldspar followed with Langmuir and extended Langmuir isotherms in single and binary systems, respectively. Adsorption kinetic of dyes was found to conform to pseudo-second order kinetic in single and binary system. The thermodynamic data showed that dye adsorption onto Feldspar was spontaneous, endothermic, and physisorption reaction. Based on the data of the pr...