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Sample records for binary mixtures composed

  1. Eutectic behaviour of binary mixtures composed of two isomeric lactic acid derivatives

    Czech Academy of Sciences Publication Activity Database

    Bubnov, Alexej; Podoliak, Natalia; Hamplová, Věra; Tomášková, Petra; Havlíček, Jaroslav; Kašpar, Miroslav

    2016-01-01

    Roč. 495, č. 1 (2016), s. 105-115 ISSN 0015-0193 R&D Projects: GA ČR GA16-12150S; GA MŠk(CZ) LH15305; GA MŠk(CZ) LD14007; GA ČR GA15-02843S Grant - others:EU - ICT (XE) COST Action IC1208 Institutional support: RVO:68378271 Keywords : ferroelectric smectic phase * binary mixture * lactic acid derivative * isomer * phase diagram * self-assembling behaviour Subject RIV: JJ - Other Materials Impact factor: 0.551, year: 2016

  2. Measurement and correlation of (vapour–liquid) equilibrium for binary mixtures composed of 1-(ethoxymethoxy)-propane with ethanol and 1-propanol at 101.33 kPa

    International Nuclear Information System (INIS)

    Song, Yu-He; Wei, Ping-He; Song, Juan; Huang, Hua; Li, Joshua Qingsong

    2017-01-01

    Highlights: • The VLE data of 1-(ethoxymethoxy)-propane with ethanol and 1-propanol were reported. • A series of saturated vapor pressure data of 1-(ethoxymethoxy)-propane were reported. • The VLE data provide a reference for separating 1-(ethoxymethoxy)-propane. - Abstract: Experimental vapour–liquid equilibrium (VLE) for binary mixtures composed of 1-(ethoxymethoxy)-propane with ethanol and 1-propanol at 101.33 kPa was measured. The experimental data of saturated vapour pressure for 1-(ethoxymethoxy)-propane was measured. The measurements were performed using an improved Rose equilibrium still. Two binary systems present a minimum boiling azeotropes at 101.33 kPa, in which the azeotropic temperature and composition are 351.45 K and 95.98 mol% (ethanol) and 369.44 K and 81.30 mol% (1-propanol), respectively. The VLE experimental values were correlated with the help of the NRTL, Wilson, and van Laar models for which the binary interaction parameters are reported. The results showed that the measurements have a good correlation under the NRTL and Wilson models about two binary systems, respectively. The thermodynamic consistency of the VLE experimental data was checked using the traditional area test and the direct test methods.

  3. Spinodal decomposition of chemically reactive binary mixtures

    Science.gov (United States)

    Lamorgese, A.; Mauri, R.

    2016-08-01

    We simulate the influence of a reversible isomerization reaction on the phase segregation process occurring after spinodal decomposition of a deeply quenched regular binary mixture, restricting attention to systems wherein material transport occurs solely by diffusion. Our theoretical approach follows a diffuse-interface model of partially miscible binary mixtures wherein the coupling between reaction and diffusion is addressed within the frame of nonequilibrium thermodynamics, leading to a linear dependence of the reaction rate on the chemical affinity. Ultimately, the rate for an elementary reaction depends on the local part of the chemical potential difference since reaction is an inherently local phenomenon. Based on two-dimensional simulation results, we express the competition between segregation and reaction as a function of the Damköhler number. For a phase-separating mixture with components having different physical properties, a skewed phase diagram leads, at large times, to a system converging to a single-phase equilibrium state, corresponding to the absolute minimum of the Gibbs free energy. This conclusion continues to hold for the critical phase separation of an ideally perfectly symmetric binary mixture, where the choice of final equilibrium state at large times depends on the initial mean concentration being slightly larger or less than the critical concentration.

  4. in Binary Liquid Mixtures of Ethyl benzoate

    Directory of Open Access Journals (Sweden)

    Shaik Babu

    2012-01-01

    Full Text Available Ultrasonic velocity is measured at 2MHz frequency in the binary mixtures of Ethyl Benzoate with 1-Propanol, 1-Butanol, 1-Pentanol and theoretical values of ultrasonic velocity have been evaluated at 303K using Nomoto's relation, Impedance relation, Ideal mixture relation, Junjie's method and free length theory. Theoretical values are compared with the experimental values and the validity of the theories is checked by applying the chi-square test for goodness of fit and by calculating the average percentage error (APE. A good agreement has been found between experimental and Nomoto’s ultrasonic velocity.

  5. Pattern formation in phase separating binary mixtures.

    Science.gov (United States)

    Sam, Ebie M; Hayase, Yumino; Auernhammer, Günter K; Vollmer, Doris

    2011-08-07

    We experimentally investigate the interplay of thermodynamics with hydrodynamics during phase separation of (quasi-) binary mixtures. Well defined patterns emerge while slowly crossing the cloud point curve. Depending on the material parameters of the experimental system, two distinct scenarios are observed. In quasi-binary mixtures of methanol-hexane patterns appear before macroscopic phase separation sets in. In course of time the patterns turn faint while the overall turbidity of the sample increases until the mixtures become completely turbid. We attribute this pattern formation to a latent heat induced instability resembling a Rayleigh-Bénard instability. This is confirmed by calorimetric data and an estimate of its Rayleigh number. Mixtures of C(4)E(1)-water doped with decane phase separate under heating. After passing the cloud point curve these mixtures first become homogenously turbid. While clearing up, pattern formation is observed. We attribute this type of pattern formation to an interfacial tension induced Bénard-Marangoni instability. The occurrence of the two scenarios is supported by the relevant dimensionless numbers. This journal is © the Owner Societies 2011

  6. Diffusive flux of energy in binary mixtures

    International Nuclear Information System (INIS)

    Sampaio, R.S.

    1976-04-01

    The diffusive flux of energy j tilde is studied through the reduced diffusive flux of energy K tilde, which obeys equations of the form: sim(delta K tilde/delta grad rho sub(α))= sim(delta K tilde/delta grad theta)=0. By a representation theorem, herein proved, is obtained a general representation for K tilde which is simplified, for the case of binary mixtures, using the principle of objectivity. Some consequences of this representation are discussed such as the symmetry of the partial stresses T 1 tilde and T 2 tilde and the difference between the normal stresses [pt

  7. Pycnonuclear reaction rates for binary ionic mixtures

    Science.gov (United States)

    Ichimaru, S.; Ogata, S.; Van Horn, H. M.

    1992-01-01

    Through a combination of compositional scaling arguments and examinations of Monte Carlo simulation results for the interparticle separations in binary-ionic mixture (BIM) solids, we have derived parameterized expressions for the BIM pycnonuclear rates as generalizations of those in one-component solids obtained previously by Salpeter and Van Horn and by Ogata et al. We have thereby discovered a catalyzing effect of the heavier elements, which enhances the rates of reactions among the lighter elements when the charge ratio exceeds a critical value of approximately 2.3.

  8. Wetting and evaporation of binary mixture drops.

    Science.gov (United States)

    Sefiane, Khellil; David, Samuel; Shanahan, Martin E R

    2008-09-11

    Experimental results on the wetting behavior of water, methanol, and binary mixture sessile drops on a smooth, polymer-coated substrate are reported. The wetting behavior of evaporating water/methanol drops was also studied in a water-saturated environment. Drop parameters (contact angle, shape, and volume) were monitored in time. The effects of the initial relative concentrations on subsequent evaporation and wetting dynamics were investigated. Physical mechanisms responsible for the various types of wetting behavior during different stages are proposed and discussed. Competition between evaporation and hydrodynamic flow are evoked. Using an environment saturated with water vapor allowed further exploration of the controlling mechanisms and underlying processes. Wetting stages attributed to differential evaporation of methanol were identified. Methanol, the more volatile component, evaporates predominantly in the initial stage. The data, however, suggest that a small proportion of methanol remained in the drop after the first stage of evaporation. This residual methanol within the drop seems to influence subsequent wetting behavior strongly.

  9. Phase separation in binary hard-core mixtures

    NARCIS (Netherlands)

    Dijkstra, Marjolein; Frenkel, D.; Hansen, J.-P.

    1994-01-01

    We report the observation of a purely entropic demixing transition in a three-dimensional binary hard-core mixture by computer simulations. This transition is observed in a lattice model of a binary hard-core mixture of parallel cubes provided that the size asymmetry of the large and small particles

  10. Research note : Miscibility behaviour of binary mixtures of benzyl ...

    African Journals Online (AJOL)

    Miscibility of binary mixtures of benzyl benzoate and liquid paraffin as functions of temperature and composition has been determined using phase separation method. The binary mixtures demonstrated a critical (upper) solution temperature of 35 °C at 101325 Nm-2 with a mixing gap. A tie-line drawn at 28 °C across the ...

  11. Hydrodynamic 'memory' of binary fluid mixtures

    International Nuclear Information System (INIS)

    Kalashnik, M. V.; Ingel, L. Kh.

    2006-01-01

    A theoretical analysis is presented of hydrostatic adjustment in a two-component fluid system, such as seawater stratified with respect to temperature and salinity. Both linear approximation and nonlinear problem are investigated. It is shown that scenarios of relaxation to a hydrostatically balanced state in binary fluid mixtures may substantially differ from hydrostatic adjustment in fluids that can be stratified only with respect to temperature. In particular, inviscid two-component fluids have 'memory': a horizontally nonuniform disturbance in the initial temperature or salinity distribution does not vanish even at the final stage, transforming into a persistent thermohaline 'trace.' Despite stability of density stratification and convective stability of the fluid system by all known criteria, an initial temperature disturbance may not decay and may even increase in amplitude. Moreover, its sign may change (depending on the relative contributions of temperature and salinity to stable background density stratification). Hydrostatic adjustment may involve development of discontinuous distributions from smooth initial temperature or concentration distributions. These properties of two-component fluids explain, in particular, the occurrence of persistent horizontally or vertically nonuniform temperature and salinity distributions in the ocean, including discontinuous ones

  12. Dielectric studies of binary mixtures of -propyl alcohol and ...

    Indian Academy of Sciences (India)

    Dielectric constant (') and dielectric loss (") of -propyl alcohol (PA), ethylenediamine (EDA) and their binary mixtures, for different mole fractions of ethylenediamine have been experimentally measured at 11.15 GHz microwave frequency. Values of density (), viscosity () and square refractive index ( n D 2 ) of binary ...

  13. Widom Lines in Binary Mixtures of Supercritical Fluids.

    Science.gov (United States)

    Raju, Muralikrishna; Banuti, Daniel T; Ma, Peter C; Ihme, Matthias

    2017-06-08

    Recent experiments on pure fluids have identified distinct liquid-like and gas-like regimes even under supercritical conditions. The supercritical liquid-gas transition is marked by maxima in response functions that define a line emanating from the critical point, referred to as Widom line. However, the structure of analogous state transitions in mixtures of supercritical fluids has not been determined, and it is not clear whether a Widom line can be identified for binary mixtures. Here, we present first evidence for the existence of multiple Widom lines in binary mixtures from molecular dynamics simulations. By considering mixtures of noble gases, we show that, depending on the phase behavior, mixtures transition from a liquid-like to a gas-like regime via distinctly different pathways, leading to phase relationships of surprising complexity and variety. Specifically, we show that miscible binary mixtures have behavior analogous to a pure fluid and the supercritical state space is characterized by a single liquid-gas transition. In contrast, immiscible binary mixture undergo a phase separation in which the clusters transition separately at different temperatures, resulting in multiple distinct Widom lines. The presence of this unique transition behavior emphasizes the complexity of the supercritical state to be expected in high-order mixtures of practical relevance.

  14. Binary mixtures of carbon dioxide and dimethyl ether as alternative ...

    African Journals Online (AJOL)

    Vapor-liquid equilibrium (VLE) data were predicted for the binary mixture of carbon dioxide (CO2) and dimethyl ether (DME) at ten temperatures ranging from 273.15 to 386.56 K and pressure upto 7.9 MPa to observe this mixture's potential of COP enhancement and capacity modulation as a working fluid in a refrigeration ...

  15. Ultrasonic study of molecular interaction in binary liquid mixtures at ...

    Indian Academy of Sciences (India)

    physics pp. 695–701. Ultrasonic study of molecular interaction in binary liquid mixtures at 30 о. C. A ALI and A K NAIN. Department of Chemistry, Jamia Millia ... The variation of these parameters with composition of the mixture helps ... AR grade, 99.5 and 99.0%, respectively) were purified by standard procedure [11]. The.

  16. Segregation of granular binary mixtures by a ratchet mechanism.

    Science.gov (United States)

    Farkas, Zénó; Szalai, Ferenc; Wolf, Dietrich E; Vicsek, Tamás

    2002-02-01

    We report on a segregation scheme for granular binary mixtures, where the segregation is performed by a ratchet mechanism realized by a vertically shaken asymmetric sawtooth-shaped base in a quasi-two-dimensional box. We have studied this system by computer simulations and found that most binary mixtures can be segregated using an appropriately chosen ratchet, even when the particles in the two components have the same size and differ only in their normal restitution coefficient or friction coefficient. These results suggest that the components of otherwise nonsegregating granular mixtures may be separated using our method.

  17. Spectrophotometric determination of volautile inorganic hydrides in binary gaseous mixtures

    International Nuclear Information System (INIS)

    Rezchikov, V.G.; Skachkova, I.N.; Kuznetsova, T.S.; Khrushcheva, V.V.

    1985-01-01

    A study was made on possibility of single and continuons analysis of binary mixtures (hydride-gas) for the content of volatile inorganic hydrides (VIH) from absorption spectra in the 185-280 nm band. Dependences of the percentage of VIH transmission on the wavelength are presented. It is shown that the maximum of their absorption depends on the element-hydrogen the bond length and binding energy. Detection limit for boron hydride was established to be n x 10 -3 % vol at 185-190 nm wavelength. Technique for spectrophotometric hydride determination in binary mixtures with hydrogen, argon, helium was developed. The technique provides the continuous control of gaseous mixture composition

  18. Evaporation of binary mixtures in microgravity

    Science.gov (United States)

    Girgis, Morris; Matta, Nabil; Kolli, Kiran; Brown, Leon; Chubb, Kevin

    1995-01-01

    The motivation of this research is to obtain a better understanding of phase-change heat transfer within single and binary liquid meniscii, both in 1-g and 0-g environments. During phase 1 and part of phase 2, in a glass test cell with an inclined heated plate, 1-6 experiments on pentane with additions of decane up to 3% were conducted to determine the optimum concentration that will exhibit the maximum heat transfer and stability. During phase 2 emphasis was given to explore fundamental research issues and to ultimately develop a reliable capillary pumped loop (CPL) device for low gravity. In related experimental work, it was found that thermocapillary stresses near the contract line could result in a degraded wettability which ultimately could explain the observed failure of CPL devices in zero-gravity environment. Therefore, the current experimental effort investigates the effect of adding binary constituents in improving the thermocapillary characteristics near the contact line within the loop configuration. Achievements during second phase include: (1) Further enhancement of Central State University's Microgravity Laboratory by adding or improving upon capabilities of photography, video imaging, fluid visualization, and general experimental testing capabilities; (2) Experimental results for the inclined plate cell; (3) Modeling effort with a detailed scaling analysis; (4) Additional testing with a tube loop configuration to extend experimental work by Dickens, et al.; (5) Fabrication of a capillary loop to be tested using binary fluid (pentane/decane). The device that has been recently completed will be set up horizontally so that the effect of gravity on the performance is negligible. Testing will cover a wide range of parameters such as decane/pentane concentration, heat input value, heat input location (below or above meniscus), and loop temperature.

  19. Superlattice configurations in linear chain hydrocarbon binary mixtures

    Indian Academy of Sciences (India)

    Unknown

    of n-C28H58 hydrocarbon, through an angle mθ, where m = 1, 2, 3 … and angle θ has an average value of. 3.3°. Supporting literature ... Keywords. Long-chain alkanes; binary mixtures; superlattices; discrete orientational changes. 1. Introduction ... tem and a model of superlattice configuration was proposed4, in terms of ...

  20. Relaxation in binary mixtures: Non-ideality, heterogeneity and re ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 5-6. Relaxation in ... Binary mixtures show many kinds of fascinating dynamical behaviour which has eluded microscopic description till very recently. In this work we show ... Specifically, three well-known problems have been addressed here. Non-ideality in ...

  1. Dielectric relaxation of binary polar liquid mixture measured in ...

    Indian Academy of Sciences (India)

    The dielectric relaxation times τjk's and dipole moments µjk's of the binary. (jk) polar liquid mixture of N,N-dimethyl acetamide (DMA) and acetone (Ac) dissolved in benzene (i) are estimated from the measured real σijk and imaginary σijk parts of complex high frequency conductivity σ∗ ijk of the solution for different weight ...

  2. Excess molar volumes and viscosities of binary mixtures of some ...

    Indian Academy of Sciences (India)

    Unknown

    Excess molar volumes and viscosities of binary mixtures of some polyethers with 1-propanol at 288⋅⋅15, 298⋅⋅15, and. 308⋅⋅15 K. AMALENDU PAL* and ANIL KUMAR. Department of Chemistry, Kurukshetra University, Kurukshetra 136 119, India e-mail: palchem@sify.com. MS received 5 May 2003; revised 15 ...

  3. Excess molar volumes, and refractive index of binary mixtures of ...

    African Journals Online (AJOL)

    Excess molar volumes (VE) viscosities and refractive index have been evaluated for binary mixtures of glycerol + water, and glycerol + methanol at 298.15 K and 303.15 K. Excess molar volumes (VE) have been calculated from density. The excess molar volume (VE) results were fitted to the Redlich and Kister type ...

  4. Composition dependent non-ideality in aqueous binary mixtures as ...

    Indian Academy of Sciences (India)

    Abstract. We explore the potential energy landscape of structure breaking binary mixtures (SBBM) where two constituents dislike each other, yet remain macroscopically homogeneous at intermediate to high temper- atures. Interestingly, we find that the origin of strong composition dependent non-ideal behaviour lies in its.

  5. Steady-state organization of binary mixtures by active impurities

    DEFF Research Database (Denmark)

    Sabra, Mads Christian; Gilhøj, Henriette; Mouritsen, Ole G.

    1998-01-01

    The structural reorganization of a phase-separated binary mixture in the presence of an annealed dilution of active impurities is studied by computer-simulation techniques via a simple two-dimensional lattice-gas model. The impurities, each of which has two internal states with different affinity...

  6. Diffusion measurements in binary liquid mixtures by Raman spectroscopy

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Hansen, Susanne Brunsgaard; Shapiro, Alexander

    2007-01-01

    It is shown that Raman spectroscopy allows determination of the molar fractions in mixtures subjected to molecular diffusion. Spectra of three binary systems, benzene/n-hexane, benzene/cyclohexane, and benzene/ acetone, were obtained during vertical (exchange) diffusion at several different heights...

  7. Composition measurements of binary mixture droplets by rainbow refractometry.

    Science.gov (United States)

    Wilms, J; Weigand, B

    2007-04-10

    So far, refractive index measurements by rainbow refractometry have been used to determine the temperature of single droplets and ensembles of droplets. Rainbow refractometry is, for the first time, to the best of our knowledge, applied to measure composition histories of evaporating, binary mixture droplets. An evaluation method is presented that makes use of Airy theory and the simultaneous size measurement by Mie scattering imaging. The method further includes an empirical correction function for a certain diameter and refractive index range. The measurement uncertainty was investigated by numerical simulations with Lorenz-Mie theory. For the experiments, an optical levitation setup was used allowing for long measurement periods. Temperature measurements of single-component droplets at different temperature levels are shown to demonstrate the accuracy of rainbow refractometry. Measurements of size and composition histories of binary mixture droplets are presented for two different mixtures. Experimental results show good agreement with numerical results using a rapid-mixing model.

  8. Composition measurements of binary mixture droplets by rainbow refractometry

    International Nuclear Information System (INIS)

    Wilms, J.; Weigand, B.

    2007-01-01

    So far, refractive index measurements by rainbow refractometry have been used to determine the temperature of single droplets and ensembles of droplets. Rainbow refractometry is, for the first time, to the best of our knowledge, applied to measure composition histories of evaporating, binary mixture droplets. An evaluation method is presented that makes use of Airy theory and the simultaneous size measurement by Mie scattering imaging. The method further includes an empirical correction function for a certain diameter and refractive index range. The measurement uncertainty was investigated by numerical simulations with Lorenz-Mie theory. For the experiments, an optical levitation setup was used allowing for long measurement periods. Temperature measurements of single-component droplets at different temperature levels are shown to demonstrate the accuracy of rainbow refractometry. Measurements of size and composition histories of binary mixture droplets are presented for two different mixtures. Experimental results show good agreement with numerical results using a rapid-mixing model

  9. A classification system for tableting behaviors of binary powder mixtures

    Directory of Open Access Journals (Sweden)

    Changquan Calvin Sun

    2016-08-01

    Full Text Available The ability to predict tableting properties of a powder mixture from individual components is of both fundamental and practical importance to the efficient formulation development of tablet products. A common tableting classification system (TCS of binary powder mixtures facilitates the systematic development of new knowledge in this direction. Based on the dependence of tablet tensile strength on weight fraction in a binary mixture, three main types of tableting behavior are identified. Each type is further divided to arrive at a total of 15 sub-classes. The proposed classification system lays a framework for a better understanding of powder interactions during compaction. Potential applications and limitations of this classification system are discussed.

  10. Shear viscosity of binary mixtures: The Gay–Berne potential

    International Nuclear Information System (INIS)

    Khordad, R.

    2012-01-01

    Highlights: ► Most useful potential model to study the real systems is the Gay–Berne (GB) potential. ► We use GB model to examine thermodynamical properties of some anisotropic binary mixtures in two different phases. ► The integral equation methods are applied to solve numerically the Percus–Yevick (PY) equation. ► We obtain expansion coefficients of correlation functions needed to calculate the properties of studied mixtures. ► The results are compared with the available experimental data [e.g., HFC-125 + propane, R-125/143a, methanol + toluene, etc.] - Abstract: The Gay–Berne (GB) potential model is an interesting and useful model to study the real systems. Using the potential model, we intend to examine the thermodynamical properties of some anisotropic binary mixtures in two different phases, liquid and gas. For this purpose, we apply the integral equation method and solve numerically the Percus–Yevick (PY) integral equation. Then, we obtain the expansion coefficients of correlation functions to calculate the thermodynamical properties. Finally, we compare our results with the available experimental data [e.g., HFC-125 + propane, R-125/143a, methanol + toluene, benzene + methanol, cyclohexane + ethanol, benzene + ethanol, carbon tetrachloride + ethyl acetate, and methanol + ethanol]. The results show that the GB potential model is capable for predicting the thermodynamical properties of binary mixtures with acceptable accuracy.

  11. Theory of amorphous packings of binary mixtures of hard spheres.

    Science.gov (United States)

    Biazzo, Indaco; Caltagirone, Francesco; Parisi, Giorgio; Zamponi, Francesco

    2009-05-15

    We extend our theory of amorphous packings of hard spheres to binary mixtures and more generally to multicomponent systems. The theory is based on the assumption that amorphous packings produced by typical experimental or numerical protocols can be identified with the infinite pressure limit of long-lived metastable glassy states. We test this assumption against numerical and experimental data and show that the theory correctly reproduces the variation with mixture composition of structural observables, such as the total packing fraction and the partial coordination numbers.

  12. Asymptotic Limits for Transport in Binary Stochastic Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Prinja, A. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-05-01

    The Karhunen-Loeve stochastic spectral expansion of a random binary mixture of immiscible fluids in planar geometry is used to explore asymptotic limits of radiation transport in such mixtures. Under appropriate scalings of mixing parameters - correlation length, volume fraction, and material cross sections - and employing multiple- scale expansion of the angular flux, previously established atomic mix and diffusion limits are reproduced. When applied to highly contrasting material properties in the small cor- relation length limit, the methodology yields a nonstandard reflective medium transport equation that merits further investigation. Finally, a hybrid closure is proposed that produces both small and large correlation length limits of the closure condition for the material averaged equations.

  13. Segregation in inclined flows of binary mixtures of spheres

    Directory of Open Access Journals (Sweden)

    Larcher Michele

    2017-01-01

    Full Text Available We outline the equations that govern the evolution of segregation of a binary mixture of spheres in flows down inclines. These equations result from the mass and momentum balances of a kinetic theory for dense flows of inelastic spheres that interact through collisions. The theory employed for segregation is appropriate for particles with relatively small differences in size and mass. The flow of the mixture is assumed to reach a fully developed state much more rapidly than does the concentrations of the two species. We illustrate the predictions of the theory for a mixture of spheres of the same diameter but different masses and for spheres of different diameters but nearly the same mass. We show the evolution of the profiles of the concentration fractions of the two types of spheres and the profiles in the final, steady state. The latter compare favourably with those obtained in discrete-element numerical simulations.

  14. Modeling adsorption of binary and ternary mixtures on microporous media

    DEFF Research Database (Denmark)

    Monsalvo, Matias Alfonso; Shapiro, Alexander

    2007-01-01

    The goal of this work is to analyze the adsorption of binary and ternary mixtures on the basis of the multicomponent potential theory of adsorption (MPTA). In the MPTA, the adsorbate is considered as a segregated mixture in the external potential field emitted by the solid adsorbent. This makes...... it possible using the same equation of state to describe the thermodynamic properties of the segregated and the bulk phases. For comparison, we also used the ideal adsorbed solution theory (IAST) to describe adsorption equilibria. The main advantage of these two models is their capabilities to predict...... multicomponent adsorption equilibria on the basis of single-component adsorption data. We compare the MPTA and IAST models to a large set of experimental data, obtaining reasonable good agreement with experimental data and high degree of predictability. Some limitations of both models are also discussed....

  15. Studying of crystal growth and overall crystallization of naproxen from binary mixtures.

    Science.gov (United States)

    Kaminska, E; Madejczyk, O; Tarnacka, M; Jurkiewicz, K; Kaminski, K; Paluch, M

    2017-04-01

    Broadband dielectric spectroscopy (BDS) and differential scanning calorimetry (DSC) were applied to investigate the molecular dynamics and phase transitions in binary mixtures composed of naproxen (NAP) and acetylated saccharides: maltose (acMAL) and sucrose (acSUC). Moreover, the application of BDS method and optical microscopy enabled us to study both crystallization kinetics and crystal growth of naproxen from the solid dispersions with the highest content of modified carbohydrates (1:5wt ratio). It was found that the activation barriers of crystallization estimated from dielectric measurements are completely different for both studied herein mixtures. Much higher E a (=205kJ/mol) was obtained for NAP-acMAL solid dispersion. It is probably due to simultaneous crystallization of both components of the mixture. On the other hand, lower value of E a in the case of NAP-acSUC solid dispersion (81kJ/mol) indicated, that naproxen is the only crystallizing compound. This hypothesis was confirmed by X-ray diffraction studies. We also suggested that specific intermolecular dipole-dipole interactions between active substance and excipient may be an alternative explanation for the difference between activation barrier obtained for NAP-acMAL and NAP-acSUC binary mixtures. Furthermore, optical measurements showed that the activation energy for crystal growth of naproxen increases in binary mixtures. They also revealed that both excipients: acMAL and acSUC move the temperature of the maximum of crystal growth towards lower temperatures. Interestingly, this maximum occurs for nearly the same structural relaxation time, which is a good approximation of viscosity, for all samples. Finally, it was also noticed that although naproxen crystallizes to the same polymorphic form in both systems, there are some differences in morphology of obtained crystals. Thus, the observed behavior may have a significant impact on the bioavailability and dissolution rate of API produced in that way

  16. Drug-excipient compatibility studies in binary mixtures of avobenzone.

    Science.gov (United States)

    Ceresole, Rita; Han, Yong K; Rosasco, Maria A; Orelli, Liliana R; Segall, Adriana

    2013-01-01

    During preformulation studies of cosmetic/pharmaceutical products, thermal analysis techniques are very useful to detect physical or chemical incompatibilities between the active and the excipients of interest that might interfere with safety and/or efficacy of the final product. Differential scanning calorimetry (DSC) was used as a screening technique for assessing the compatibility of avobenzone with some currently used cosmetic excipients. In the first phase of the study, DSC was used as a tool to detect any interaction. Based on the DSC results alone, cetearyl alcohol, isopropyl myristate, propylparaben, diethylhexyl syringylidene malonate, caprylic capric triglyceride, butylated hydroxytoluene (BHT), glycerin, cetearyl alcohol/ceteareth 20, cetearyl alcohol/sodium lauryl sulfate/sodium cetearyl sulfate, and paraffinum liquidum exhibit interaction with avobenzone. Stressed binary mixtures (stored at 50°C for 15 days) of avobenzone and excipients were evaluated by high-performance liquid chromatography. Binary mixtures were further investigated by infrared (IR) spectroscopy. Based on DSC, isothermal stress testing, and fourier transform infrared results; avobenzone is incompatible with caprylic capric triglyceride, propylparaben, and BHT.

  17. Thermodynamic and Thermomicroscopy Study of Atorvastatin Calcium-Succinic Acid Binary Mixtures

    OpenAIRE

    Yudi Wicaksono; Budipratiwi Wisudyaningsih; Frida Oktaningtias Widiarthi; Tri Agus Siswoyo

    2017-01-01

    Binary mixtures of pharmaceuticals significantly affect the physical and chemical properties of each component. The aim of this work was to explore the thermal behavior and solid state transformation of binary mixture of atorvastatin calcium and succinic acid. The thermodynamics of binary mixtures of atorvastatin calcium - succinic acid were determined by differential scanning calorimeter. Meanwhile, thermomicroscopy and microstructure were determined by a polarized microscope equipped with a...

  18. Modeling phase equilibria for acid gas mixtures using the CPA equation of state. Part II: Binary mixtures with CO2

    DEFF Research Database (Denmark)

    Tsivintzelis, Ioannis; Kontogeorgis, Georgios; Michelsen, Michael Locht

    2011-01-01

    In Part I of this series of articles, the study of H2S mixtures has been presented with CPA. In this study the phase behavior of CO2 containing mixtures is modeled. Binary mixtures with water, alcohols, glycols and hydrocarbons are investigated. Both phase equilibria (vapor–liquid and liquid–liqu...

  19. Stability studies of colloidal silica dispersions in binary solvent mixtures

    CERN Document Server

    Bean, K H

    1997-01-01

    A series of monodispersed colloidal silica dispersions, of varying radii, has been prepared. These particles are hydrophilic in nature due to the presence of surface silanol groups. Some of the particles have been rendered hydrophobic by terminally grafting n-alkyl (C sub 1 sub 8) chains to the surface. The stability of dispersions of these various particles has been studied in binary mixtures of liquids, namely (i) ethanol and cyclohexane, and (ii) benzene and n-heptane. The ethanol - cyclohexane systems have been studied using a variety of techniques. Adsorption excess isotherms have been established and electrophoretic mobility measurements have been made. The predicted stability of the dispersions from D.V.L.O. calculations is compared to the observed stability. The hydrophilic silica particles behave as predicted by the calculations, with the zeta potential decreasing and the van der Waals attraction increasing with increasing cyclohexane concentration. The hydrophobic particles behave differently than e...

  20. Separation of a binary mixture by sequential centrifugal partition chromatography.

    Science.gov (United States)

    Hopmann, Elisabeth; Minceva, Mirjana

    2012-03-16

    Sequential centrifugal partition chromatography (sCPC) is a novel continuous cyclic liquid-liquid chromatographic separation technology. Each cycle of the process comprises two steps, which differ by the liquid phase used as mobile phase (upper or lower phase) and its flow direction. The feed is introduced continuously in the unit and two product streams are collected alternately, in each step of the cycle. In this work, the sCPC was modeled using the stage (cell) model. The model was used to simulate a separation of a model binary mixture consisting of pyrocatechol and hydroquinone. The solutes distribution constants, system hydrodynamics and mass transfer parameters were determined experimentally and implemented in the model. Furthermore, a parameter study (variation of the feed concentration and step times) was performed by experiments and simulation. A recently developed method was used to select the operating parameters of the sCPC unit. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Stability studies of colloidal silica dispersions in binary solvent mixtures

    International Nuclear Information System (INIS)

    Bean, Keith Howard

    1997-01-01

    A series of monodispersed colloidal silica dispersions, of varying radii, has been prepared. These particles are hydrophilic in nature due to the presence of surface silanol groups. Some of the particles have been rendered hydrophobic by terminally grafting n-alkyl (C 18 ) chains to the surface. The stability of dispersions of these various particles has been studied in binary mixtures of liquids, namely (i) ethanol and cyclohexane, and (ii) benzene and n-heptane. The ethanol - cyclohexane systems have been studied using a variety of techniques. Adsorption excess isotherms have been established and electrophoretic mobility measurements have been made. The predicted stability of the dispersions from D.V.L.O. calculations is compared to the observed stability. The hydrophilic silica particles behave as predicted by the calculations, with the zeta potential decreasing and the van der Waals attraction increasing with increasing cyclohexane concentration. The hydrophobic particles behave differently than expected, and the stability as a function of solvent mixture composition does not show a uniform trend. The effect of varying the coverage of C 18 chains on the surface and the effect of trace water in the systems has also been investigated. Organophilic silica dispersions in benzene - n-heptane solvent mixtures show weak aggregation and phase separation into a diffuse 'gas-like' phase and a more concentrated 'liquid-like' phase, analogous to molecular condensation processes. Calculations of the van der Waals potential as a function of solvent mixture composition show good agreement with the observed stability. Determination of the number of particles in each phase at equilibrium allows the energy of flocculation to be determined using a simple thermodynamic relationship. Finally, the addition of an AB block copolymer to organophilic silica particles in benzene n-heptane solvent mixtures has been shown to have a marked effect on the dispersion stability. This stability

  2. A Variational approach to thin film hydrodynamics of binary mixtures

    KAUST Repository

    Xu, Xinpeng

    2015-02-04

    In order to model the dynamics of thin films of mixtures, solutions, and suspensions, a thermodynamically consistent formulation is needed such that various coexisting dissipative processes with cross couplings can be correctly described in the presence of capillarity, wettability, and mixing effects. In the present work, we apply Onsager\\'s variational principle to the formulation of thin film hydrodynamics for binary fluid mixtures. We first derive the dynamic equations in two spatial dimensions, one along the substrate and the other normal to the substrate. Then, using long-wave asymptotics, we derive the thin film equations in one spatial dimension along the substrate. This enables us to establish the connection between the present variational approach and the gradient dynamics formulation for thin films. It is shown that for the mobility matrix in the gradient dynamics description, Onsager\\'s reciprocal symmetry is automatically preserved by the variational derivation. Furthermore, using local hydrodynamic variables, our variational approach is capable of introducing diffusive dissipation beyond the limit of dilute solute. Supplemented with a Flory-Huggins-type mixing free energy, our variational approach leads to a thin film model that treats solvent and solute in a symmetric manner. Our approach can be further generalized to include more complicated free energy and additional dissipative processes.

  3. Evaporation dynamics and Marangoni number estimation for sessile picoliter liquid drop of binary mixture solution

    Directory of Open Access Journals (Sweden)

    Lebedev-Stepanov Peter

    2016-01-01

    Full Text Available We propose the evaporation model of picoliter sessile drop of binary solvent mixture (with infinitely soluble in each other components based on Hu and Larson solution for single solvent sessile drop and Raoult law for saturated vapor density of components of binary mixture in wide range of undimensional molar binary concentration of the components. Concentration Marangoni number estimation for such a system is also considered for prediction of liquid flows structure for further applications in dissipative particle dynamics in binary mixture evaporating drop.

  4. Evaporation dynamics and Marangoni number estimation for sessile picoliter liquid drop of binary mixture solution

    OpenAIRE

    Lebedev-Stepanov Peter; Kobelev Alexander; Efimov Sergey

    2016-01-01

    We propose the evaporation model of picoliter sessile drop of binary solvent mixture (with infinitely soluble in each other components) based on Hu and Larson solution for single solvent sessile drop and Raoult law for saturated vapor density of components of binary mixture in wide range of undimensional molar binary concentration of the components. Concentration Marangoni number estimation for such a system is also considered for prediction of liquid flows structure for further applications ...

  5. Assessment and prediction of joint algal toxicity of binary mixtures of graphene and ionic liquids.

    Science.gov (United States)

    Wang, Zhuang; Zhang, Fan; Wang, Se; Peijnenburg, Willie J G M

    2017-10-01

    Graphene and ionic liquids (ILs) released into the environment will interact with each other. So far however, the risks associated with the concurrent exposure of biota to graphene and ILs in the environment have received little attention. The research reported here focused on observing and predicting the joint toxicity effects in the green alga Scenedesmus obliquus exposed to binary mixtures of intrinsic graphene (iG)/graphene oxide (GO) and five ILs of varying anionic and cationic types. The isolated ILs in the binary mixtures were the main contributors to toxicity. The binary GO-IL mixtures resulted in more severe joint toxicity than the binary iG-IL mixtures, irrespective of mixture ratios. The mechanism of the joint toxicity may be associated with the adsorption capability of the graphenes for the ILs, the dispersion stability of the graphenes in aquatic media, and modulation of the binary mixtures-induced oxidative stress. A toxic unit assessment showed that the graphene and IL toxicities were additive at low concentration of the mixtures but antagonistic at high concentration of the mixtures. Predictions made using the concentration addition and independent action models were close to the observed joint toxicities regardless of mixture types and mixture ratios. These findings provide new insights that are of use in the risk assessment of mixtures of engineered nanoparticles and other environmentally relevant contaminants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Using binary surfactant mixtures to simultaneously improve the dimensional tunability and monodispersity in the seeded growth of gold nanorods.

    Science.gov (United States)

    Ye, Xingchen; Zheng, Chen; Chen, Jun; Gao, Yuzhi; Murray, Christopher B

    2013-02-13

    We report a dramatically improved synthesis of colloidal gold nanorods (NRs) using a binary surfactant mixture composed of hexadecyltrimethylammonium bromide (CTAB) and sodium oleate (NaOL). Both thin (diameter 30 nm) gold NRs with exceptional monodispersity and broadly tunable longitudinal surface plasmon resonance can be synthesized using seeded growth at reduced CTAB concentrations (as low as 0.037 M). The CTAB-NaOL binary surfactant mixture overcomes the difficulty of growing uniform thick gold NRs often associated with the single-component CTAB system and greatly expands the dimensions of gold NRs that are accessible through a one-pot seeded growth process. Gold NRs with large overall dimensions and thus high scattering/absorption ratios are ideal for scattering-based applications such as biolabeling as well as the enhancement of optical processes.

  7. Dielectric properties of binary mixtures of ethylene glycol monophenyl ether and methanol

    Science.gov (United States)

    Vaghela, K. C.; Vankar, H. P.; Trivedi, C. M.; Rana, V. A.

    2017-05-01

    Static permittivity (ɛ0) and permittivity at optical frequency (ɛ∞) of ethylene glycol monophenyl ether (EGMPE), methanol (MeOH) and their binary mixtures of varying concentrations have been measured at room temperature (T=299.15 K). The investigation showed a systematic change in permittivity with change in concentration of MeOH in binary mixture system. Measured data have been used to calculate the various dielectric parameters such as E E excess static permittivity (ɛ0E), excess permittivity at optical frequency (ɛ∞E) and Bruggeman factor (fB). Determined parameters provided some information about the molecular interaction among the molecular species of the binary mixtures.

  8. Dielectric studies of binary mixtures of n-propyl alcohol and ...

    Indian Academy of Sciences (India)

    Unknown

    , ethylenediamine. (EDA) and their binary mixtures, for different mole fractions of ethylenediamine have been experimen- tally measured at 11⋅15 GHz microwave frequency. Values of density (ρ), viscosity (η) and square re- fractive index (n2.

  9. Diode Laser-Based Sensor for Fast Measurement of Binary Gas Mixtures

    National Research Council Canada - National Science Library

    McNesby, Kevin

    1999-01-01

    The development and characterization of a gas sensor to measure binary mixtures of oxygen and the vapor from a series of volatile organic compounds, with a time resolution of 10 milliseconds, is described...

  10. Determination of two antibacterial binary mixtures by chemometrics-assisted spectrophotometry.

    Science.gov (United States)

    Mohamed, Abd El-Maaboud I; Abdelmageed, Osama H; Refaat, Ibrahim H

    2007-01-01

    Simple chemometrics-assisted spectrophotometric methods are described for determination of 2 antibacterial binary mixtures. The mixtures are composed of norfloxacin in combination with tinidazole and erythromycin (as ethylsuccinate ester or stearate salt) in combination with trimethoprim. The normal UV absorption spectra of each pair of drugs in the studied mixtures, in the range of 200-400 nm, showed a considerable degree of spectral overlapping: 77.5% for the norfloxacin-tinidazole mixture and 84.3% for the erythromycin-trimethoprim mixture. Resolution of the norfloxacin-tinidazole mixture and trimethoprim in the presence of erythromycin was accomplished successfully by using zero-crossing first derivative (1D), classical least-squares (CLS) regression analysis, and principal component regression (PCR) analysis methods. In addition, an alternative simple and accurate colorimetric method was developed for the determination of erythromycin in the presence of trimethoprim using 2,4-dinitrophenylhydrazine. All variables affecting the development of the colored chromogen were studied and optimized, and the product was measured at 526-529 and 538-542 nm for erythromycin stearate and erythromycin ethylsuccinate, respectively. For zero-crossing, first derivative technique Beer's law was obeyed in the general concentration range of 2-50 microg/mL for norfloxacin, tinidazole, and trimethoprim with good correlation coefficients (0.9994-0.9996). Overall limits of detection (LOD) and quantification (LOQ) ranged from 0.59 to 2.81 and 1.96 to 9.33 microg/mL, respectively. The obtained results from CLS and PCR were compared with those obtained from a 1D spectrophotometric method. With the exception of erythromycin, overall recoveries in the average range of 97.33-103.0% were obtained with a considerable degree of accuracy when the suggested methods were applied to analysis of synthetic binary mixtures, some commercial dosage forms such as tablets and oral suspension without

  11. Computer simulation-molecular-thermodynamic framework to predict the micellization behavior of mixtures of surfactants: application to binary surfactant mixtures.

    Science.gov (United States)

    Iyer, Jaisree; Mendenhall, Jonathan D; Blankschtein, Daniel

    2013-05-30

    We present a computer simulation-molecular-thermodynamic (CSMT) framework to model the micellization behavior of mixtures of surfactants in which hydration information from all-atomistic simulations of surfactant mixed micelles and monomers in aqueous solution is incorporated into a well-established molecular-thermodynamic framework for mixed surfactant micellization. In addition, we address the challenges associated with the practical implementation of the CSMT framework by formulating a simpler mixture CSMT model based on a composition-weighted average approach involving single-component micelle simulations of the mixture constituents. We show that the simpler mixture CSMT model works well for all of the binary surfactant mixtures considered, except for those containing alkyl ethoxylate surfactants, and rationalize this finding molecularly. The mixture CSMT model is then utilized to predict mixture CMCs, and we find that the predicted CMCs compare very well with the experimental CMCs for various binary mixtures of linear surfactants. This paper lays the foundation for the mixture CSMT framework, which can be used to predict the micellization properties of mixtures of surfactants that possess a complex chemical architecture, and are therefore not amenable to traditional molecular-thermodynamic modeling.

  12. nth-Nearest neighbour distribution functions of a binary fluid mixture ...

    Indian Academy of Sciences (India)

    Administrator

    for ob- taining the NND functions for single component flu- ids, to binary fluid mixtures. The MD simulation and computation details are presented in section 4. Results are elaborated in section 5 and conclusions are provided in section 6. 2. n-Particle distribution function. Considering a binary system of Nα and Nβ particles.

  13. Implementation of Ultrasonic Sensing for High Resolution Measurement of Binary Gas Mixture Fractions

    CERN Document Server

    Bates, Richard; Berry, Stephane; Bitadze, Alexander; Bonneau, Pierre; Bousson, Nicolas; Boyd, George; Bozza, Gennaro; Crespo-Lopez, Olivier; Da Riva, Enrico; Degeorge, Cyril; Deterre, Cecile; DiGirolamo, Beniamino; Doubek, Martin; Favre, Gilles; Godlewski, Jan; Hallewell, Gregory; Hasib, Ahmed; Katunin, Sergey; Langevin, Nicolas; Lombard, Didier; Mathieu, Michel; McMahon, Stephen; Nagai, Koichi; Pearson, Benjamin; Robinson, David; Rossi, Cecilia; Rozanov, Alexandre; Strauss, Michael; Vitek, Michal; Vacek, Vaclav; Zwalinski, Lukasz

    2014-01-01

    We describe an ultrasonic instrument for continuous real-time analysis of the fractional mixture of a binary gas system. The instrument is particularly well suited to measurement of leaks of a high molecular weight gas into a system that is nominally composed of a single gas. Sensitivity < 5 ×10−5 is demonstrated to leaks of octaflouropropane (C3F8) coolant into nitrogen during a long duration (18 month) continuous study. The sensitivity of the described measurement system is shown to depend on the difference in molecular masses of the two gases in the mixture. The impact of temperature and pressure variances on the accuracy of the measurement is analysed. Practical considerations for the implementation and deployment of long term, in situ ultrasonic leak detection systems are also described. Although development of the described systems was motivated by the requirements of an evaporative fluorocarbon cooling system, the instrument is applicable to the detection of leaks of many other gases and to proce...

  14. Structure formation in binary mixtures of surfactants: vesicle opening-up to bicelles and octopus-like micelles

    Science.gov (United States)

    Noguchi, Hiroshi

    Micelle formation in binary mixtures of surfactants is studied using a coarse-grained molecular simulation. When a vesicle composed of lipid and detergent types of molecules is ruptured, a disk-shaped micelle, the bicelle, is typically formed. It is found that cup-shaped vesicles and bicelles connected with worm-like micelles are also formed depending on the surfactant ratio and critical micelle concentration. The obtained octopus shape of micelles agree with those observed in the cryo-TEM images reported in [S. Jain and F. S. Bates, Macromol. 37, 1511 (2004).]. Two types of connection structures between the worm-like micelles and the bicelles are revealed.

  15. Forage production of grass-legume binary mixtures on Intermountain Western USA irrigated pastures

    Science.gov (United States)

    A well-managed irrigated pasture is optimized for forage production with the use of N fertilizer which incurs extra expense. The objective was to determine which binary grass-legume mixture and mixture planting ratio of tall fescue (Festuca arundinacea Schreb.) (TF), meadow brome (Bromus bieberstei...

  16. Diffusion in Poiseuille and Couette flows of binary mixtures of incompressible newtonian fluids

    International Nuclear Information System (INIS)

    Caetano Filho, E.; Qassim, R.Y.

    1981-07-01

    Using the continuum theory of binary mixtures of incompressible Newtonian fluids, Poiseuille and Couette flows are studied with a view to determining whether diffusion occurs in such flows. It is shown that diffusion is absent in the Couette case. However, in Poiseuille flow there are significant differences between the velocities of the species comprising the mixture. This result is in broad agreement with that of Mills for similar mixtures of nonuniform composition. (Author) [pt

  17. Ultrasonic study of molecular interaction in binary liquid mixtures at ...

    Indian Academy of Sciences (India)

    The variation of these parameters with composition of the mixture helps us in understanding the nature and extent of interaction between unlike molecules in the mixtures. Further, theoretical values of ultrasonic speed were evaluated using theories and empirical relations. The relative merits of these theories and relations ...

  18. Microwave dielectric characterization of binary mixture of formamide ...

    Indian Academy of Sciences (India)

    Dielectric relaxation measurements of formamide (FMD)–,- dimethylaminoethanol (DMAE) solvent mixtures have been carried out over the entire concentration range using time domain reflectometry technique at 25, 35 and 45° C in thefrequency range of 10 MHz to 20 GHz. The mixtures exhibit a principle dispersion of ...

  19. Lattice Boltzmann model for thermal binary-mixture gas flows.

    Science.gov (United States)

    Kang, Jinfen; Prasianakis, Nikolaos I; Mantzaras, John

    2013-05-01

    A lattice Boltzmann model for thermal gas mixtures is derived. The kinetic model is designed in a way that combines properties of two previous literature models, namely, (a) a single-component thermal model and (b) a multicomponent isothermal model. A comprehensive platform for the study of various practical systems involving multicomponent mixture flows with large temperature differences is constructed. The governing thermohydrodynamic equations include the mass, momentum, energy conservation equations, and the multicomponent diffusion equation. The present model is able to simulate mixtures with adjustable Prandtl and Schmidt numbers. Validation in several flow configurations with temperature and species concentration ratios up to nine is presented.

  20. Transport properties of supercritical fluids and their binary mixtures

    CERN Document Server

    Luedemann, H D

    2002-01-01

    The molecular dynamics of the two supercritical fluids most applied in industry and some of their mixtures are characterized by their self-diffusion coefficients D sub i , measured by high pressure high resolution nuclear magnetic resonance with the strengthened glass cell technique. The technical details of the apparatus will be given. The fluids studied are carbon dioxide and ammonia. For CO sub 2 , mixtures with C sub 6 H sub 6 , H sub 2 , CH sub 3 COOH and CH sub 3 OH were investigated. The NH sub 3 mixtures include C sub 6 H sub 6 , (CH sub 3) sub 3 N, CH sub 3 CN and CH sub 3 OH.

  1. Investigation of the powder flow behaviour of binary mixtures of microcrystalline celluloses and paracetamol

    Directory of Open Access Journals (Sweden)

    Ira Soppela

    2010-03-01

    Full Text Available The flow behaviour of binary mixtures of paracetamol and different grades of microcrystalline celluloses (Avicel® PH101, PH102 and PH200 was studied using a new testing method. The effect of physical characteristics of the powder including tribocharging and the addition of lubricant on the flow properties of the different mixtures was investigated. As expected, the flowability of the samples was affected both by the amount of paracetamol and the physical properties of microcrystalline celluloses (MCC and the mixtures. The effect of lubricant varied depending on the MCC grade: magnesium stearate was able to improve the flowability of the mixtures containing PH102 and PH200 while it did not affect the flowability of PH101. Multivariate analysis showed that the flow of the binary excipient-drug mixtures through an orifice is affected by several phenomena, such as charging, surface moisture, carrier payload and particle size.

  2. Experimental study on thermal storage performance of binary mixtures of fatty acids

    Science.gov (United States)

    Yan, Quanying; Zhang, Jing; Liu, Chao; Liu, Sha; Sun, Xiangyu

    2018-02-01

    We selected five kinds of fatty acids including the capric acid, stearic acid, lauric acid, palmitic acid and myristic acid and mixed them to prepare10 kinds of binary mixtures of fatty acids according to the predetermined proportion,tested the phase change temperature and latent heat of mixtures by differential scanning calorimetry(DSC). In order to find the fatty acid mixture which has suitable phase change temperature, the larger phase change latent heat and can be used for phase change wall. The results showed that the phase change temperature and latent heats of the binary mixtures of fatty acids decreased compared with the single component;The phase change temperature of the binary mixtures of fatty acids containing capric acid were lower, the range was roughly 20∼30°C,and latent heat is large,which are ideal phase change materials for phase change wall energy storage;The phase change temperature of the binary mixtures consisting of other fatty acids were still high,didn’t meet the temperature requirements of the wall energy storage.

  3. Chemical composition and binary mixture of human urinary stones using FT-Raman spectroscopy method

    Science.gov (United States)

    Selvaraju, R.; Raja, A.; Thiruppathi, G.

    2013-10-01

    In the present study the human urinary stones were observed in their different chemical compositions of calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate, struvite (magnesium ammonium phosphate), uric acid, cystine, oxammite (ammonium oxalate monohydrate), natroxalate (sodium oxalate), glushinkite (magnesium oxalate dihydrate) and moolooite (copper oxalate) were analyzed using Fourier Transform-Raman (FT-Raman) spectroscopy. For the quantitative analysis, various human urinary stone samples are used for ratios calculation of binary mixtures compositions such as COM/COD, HAP/COD, HAP/COD, Uric acid/COM, uric acid/COD and uric acid/HAP. The calibration curve is used for further analysis of binary mixture of human urinary stones. For the binary mixture calculation the various intensities bands at 1462 cm-1 (ICOM), 1473 cm-1 (ICOD), 961 cm-1 (IHAP) and 1282 cm-1 (IUA) were used.

  4. Determination of binary mixture vapor-liquid critical densities from coexisting density data

    Science.gov (United States)

    van Poolen, L. J.; Rainwater, J. C.

    1987-11-01

    Two-phase vapor-liquid equilibrium (VLE) isochores for binary mixtures are defined as the thermodynamic paths along which the overall density and composition are fixed. Data along such isochores are generated from a modified Leung-Griffiths model fit to experimental data for the binary system nitrogen-methane. The behavior of the liquid volume fraction along these isochores is found to be similar to that for pure fluids. Rectilinear diameters for varying overall densities (fixed composition) are seen to be nearly coincident. Straight-line diameters and the critical liquid volume fraction method are utilized to predict critical densities using data near and removed from the critical point. Both methods give acceptable results but the critical liquid volume fraction method is more accurate. A critical literature review of the need for binary mixture critical densities is presented and a proposed experimental procedure is given for the determination of mixture critical densities.

  5. Binary Gas Mixtures of Light Helium to Intensify Laminar Forced Convection in Round Tubes

    Science.gov (United States)

    Campo, Antonio; Chikh, Salah; Papari, Mohammad; Mobinipouya, Mahammad

    2007-11-01

    This paper addresses potential heat transfer enhancement of laminar gaseous flows inside tubes with constant wall temperatures. The goal is to investigate the capabilities of certain binary gas mixtures of light helium as the primary gas with nitrogen, oxygen, carbon dioxide, methane, sulfur hexafluoride and tetrafluoromethane as the secondary heavier gases. The velocity of the binary gas mixtures is fully established and the temperature develops from a uniform value. The thermophysical properties of the binary gas mixtures depend on the molar gas composition in the w-domain [0, 1]. The two case studies involve a low mean bulk temperature of 300 K and the other a high mean bulk temperature of 600 K, both sharing 1 atm. The two target parameters for analysis and design are the maximum heat transfer rate and the pressure drop at the optimal molar gas composition.

  6. Investigation on some thermophysical properties of poly(ethylene glycol) binary mixtures at different temperatures

    International Nuclear Information System (INIS)

    Moosavi, Mehrdad; Motahari, Ahmad; Omrani, Abdollah; Rostami, Abbas Ali

    2013-01-01

    Highlights: ► Measuring densities and viscosities for binary mixtures of PEG + water or alcohols. ► Finding excess molar volume, refractive index and coefficient of thermal expansion. ► Estimating binary coefficients using Redlich–Kister polynomial equation. ► Deducing excess Gibbs free energy of activation and other activation parameters. ► Correlation of viscosity data with Grunberg–Nissan and Tamura–Kurata equations. -- Abstract: Densities ρ and viscosities η for the binary mixtures of poly(ethylene glycol) + water, + 1,2-ethanediol, + 1,3-propanediol, + 1,4-butanediol over the entire concentration range were determined at temperatures (298.15 to 308.15) K with 5 K interval. The experimental data were used to calculate the excess molar volume V m E , coefficient of thermal expansion α, excess coefficient of thermal expansion α E , excess Gibbs free energy of activation ΔG ∗E , and other activation parameters (i.e., ΔG ∗ ,ΔH ∗ ,ΔS ∗ ). The values of excess properties were fitted to Redlich–Kister polynomial equation to estimate the binary coefficients. The excess refractive index n E and electronic polarizability α e of PEG + water binary mixtures were also determined from the experimental values of refractive indices. The viscosity data were correlated with Grunberg–Nissan and Tamura–Kurata equations. Moreover, the Prigogine–Flory–Patterson theory has been used to correlate the excess molar volumes of the studied mixtures

  7. Microwave dielectric characterization of binary mixture of formamide ...

    Indian Academy of Sciences (India)

    C in the frequency range of 10 MHz to 20 GHz. The mixtures exhibit a principle dispersion of the Davidson–Cole relaxation type at microwave frequencies. Bilinear calibration method is used to obtain complex permittivity ε*. (ω) from complex reflection coefficient ρ*. (ω) over the frequency range of 10 MHz to 10 GHz.

  8. excess molar volumes, and refractive index of binary mixtures

    African Journals Online (AJOL)

    Preferred Customer

    because (a) water molecules have hydroxyl group which can make stronger hydrogen bonding than methanol and (b) water molecules and glycerol have suitable kinetic energy for bulk volumes at high temperature. Thus, the mixture of glycerol + water have big excess molar volume than methanol. The hydrogen bonding ...

  9. excess molar volumes, and refractive index of binary mixtures

    African Journals Online (AJOL)

    Preferred Customer

    It is observed that all mixtures show positive values of VE obviously due to increased physical interactions between glycerol and methanol, and water. KEY WORDS. KEY WORDS: Excess molar, Density, Refractive index, Glycerol, Water, Methanol. INTRODUCTION. The price of fossil diesel is soaring in the recent years and ...

  10. ON THE MOLAR POLARIZABILITIES OF BINARY MIXTURES FROM ...

    African Journals Online (AJOL)

    TBA), lso-Propyl alcohol (IPA) and Toluene (TOL) were prepared at 298k and 1 atm. Subsequently, the densities, mole fractions and refractive indices of the mixtures and their pure components were obtained at 298k. The average molar ...

  11. Structural transition in alcohol-water binary mixtures: A ...

    Indian Academy of Sciences (India)

    The strengthening of the hydrogen bonding (H-bond) network as well as transition from the tetrahedral-like water network to the zigzag chain structure of alcohol upon increasing the alcohol concentration in ethanol-water and tertiary butanol (TBA) - water mixtures have been studied by using both steady state and time ...

  12. Microwave dielectric characterization of binary mixture of formamide ...

    Indian Academy of Sciences (India)

    The mixtures exhibit a principle dispersion of the Davidson–Cole relaxation type at microwave frequencies. Bilinear calibration method is used to obtain complex permittivity *() from complex reflection coefficient ρ*() over the frequency range of 10 MHz to 10 GHz. The excess permittivity (E), excessinverse relaxation ...

  13. Structural transition in alcohol–water binary mixtures: A ...

    Indian Academy of Sciences (India)

    WINTEC

    Abstract. The strengthening of the hydrogen bonding (H-bond) network as well as transition from the tetrahedral-like water network to the zigzag chain structure of alcohol upon increasing the alcohol con- centration in ethanol–water and tertiary butanol (TBA) – water mixtures have been studied by using both steady state ...

  14. Surface Structures of Binary Mixture of Ionic Liquids.

    Czech Academy of Sciences Publication Activity Database

    Nakajima, K.; Nakanishi, S.; Lísal, Martin; Kimura, K.

    2017-01-01

    Roč. 230, MARCH (2017), s. 542-549 ISSN 0167-7322 R&D Projects: GA ČR(CZ) GA16-12291S Institutional support: RVO:67985858 Keywords : ionic liquids * mixture * surface structure Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 3.648, year: 2016

  15. Effects of three veterinary antibiotics and their binary mixtures on two green alga species.

    Science.gov (United States)

    Carusso, S; Juárez, A B; Moretton, J; Magdaleno, A

    2018-03-01

    The individual and combined toxicities of chlortetracycline (CTC), oxytetracycline (OTC) and enrofloxacin (ENF) have been examined in two green algae representative of the freshwater environment, the international standard strain Pseudokichneriella subcapitata and the native strain Ankistrodesmus fusiformis. The toxicities of the three antibiotics and their mixtures were similar in both strains, although low concentrations of ENF and CTC + ENF were more toxic in A. fusiformis than in the standard strain. The toxicological interactions of binary mixtures were predicted using the two classical models of additivity: Concentration Addition (CA) and Independent Action (IA), and compared to the experimentally determined toxicities over a range of concentrations between 0.1 and 10 mg L -1 . The CA model predicted the inhibition of algal growth in the three mixtures in P. subcapitata, and in the CTC + OTC and CTC + ENF mixtures in A. fusiformis. However, this model underestimated the experimental results obtained in the OTC + ENF mixture in A. fusiformis. The IA model did not predict the experimental toxicological effects of the three mixtures in either strain. The sum of the toxic units (TU) for the mixtures was calculated. According to these values, the binary mixtures CTC + ENF and OTC + ENF showed an additive effect, and the CTC + OTC mixture showed antagonism in P. subcapitata, whereas the three mixtures showed synergistic effects in A. fusiformis. Although A. fusiformis was isolated from a polluted river, it showed a similar sensitivity with respect to P. subcapitata when it was exposed to binary mixtures of antibiotics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Thermodynamic and Thermomicroscopy Study of Atorvastatin Calcium-Succinic Acid Binary Mixtures

    Directory of Open Access Journals (Sweden)

    Yudi Wicaksono

    2017-11-01

    Full Text Available Binary mixtures of pharmaceuticals significantly affect the physical and chemical properties of each component. The aim of this work was to explore the thermal behavior and solid state transformation of binary mixture of atorvastatin calcium and succinic acid. The thermodynamics of binary mixtures of atorvastatin calcium - succinic acid were determined by differential scanning calorimeter. Meanwhile, thermomicroscopy and microstructure were determined by a polarized microscope equipped with a heating stage and camera. The results showed that melting points of atorvastatin calcium and succinic acid respectively were 159.35 and 188.51 °C. The solid-liquid phase diagram of atorvastatin calcium - succinic acid indicates the existence of two eutectic points at 136.57 °C and 120.96 °C respectively on the mole fraction of atorvastatin calcium 0.3 and 0.5. Tamman diagram accurately shows mole fraction of atorvastatin calcium at eutectic point 0.33 and 0.46 respectively for eutectic points 130.0 °C and 134.0 °C. Determination of Jackson’s roughness parameter showed a value of atorvastatin calcium, succinic acid and eutectic mixtures > 2 which indicates that the interfaces of remelting crystals were smooth. Microstructure of remelting crystal of atorvastatin calcium and succinic acid respectively was irregular form and crossed plates. The results of thermomicroscopy of binary mixtures of atorvastatin calcium-succinic acid were consistent with differential scanning calorimetry curves and solid-liquid phase diagram.

  17. Statistical mechanics of binary mixture adsorption in metal-organic frameworks in the osmotic ensemble

    Science.gov (United States)

    Dunne, Lawrence J.; Manos, George

    2018-03-01

    Although crucial for designing separation processes little is known experimentally about multi-component adsorption isotherms in comparison with pure single components. Very few binary mixture adsorption isotherms are to be found in the literature and information about isotherms over a wide range of gas-phase composition and mechanical pressures and temperature is lacking. Here, we present a quasi-one-dimensional statistical mechanical model of binary mixture adsorption in metal-organic frameworks (MOFs) treated exactly by a transfer matrix method in the osmotic ensemble. The experimental parameter space may be very complex and investigations into multi-component mixture adsorption may be guided by theoretical insights. The approach successfully models breathing structural transitions induced by adsorption giving a good account of the shape of adsorption isotherms of CO2 and CH4 adsorption in MIL-53(Al). Binary mixture isotherms and co-adsorption-phase diagrams are also calculated and found to give a good description of the experimental trends in these properties and because of the wide model parameter range which reproduces this behaviour suggests that this is generic to MOFs. Finally, a study is made of the influence of mechanical pressure on the shape of CO2 and CH4 adsorption isotherms in MIL-53(Al). Quite modest mechanical pressures can induce significant changes to isotherm shapes in MOFs with implications for binary mixture separation processes. This article is part of the theme issue `Modern theoretical chemistry'.

  18. Thermodynamic studies of mixtures for topical anesthesia: Lidocaine-salol binary phase diagram

    Energy Technology Data Exchange (ETDEWEB)

    Lazerges, Mathieu [Laboratoire de Chimie Physique (EA 4066), Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, 4 Avenue de l' Observatoire, 75270 Paris Cedex 06 (France); Rietveld, Ivo B., E-mail: ivo.rietveld@parisdescartes.fr [Laboratoire de Chimie Physique (EA 4066), Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, 4 Avenue de l' Observatoire, 75270 Paris Cedex 06 (France); Corvis, Yohann; Ceolin, Rene; Espeau, Philippe [Laboratoire de Chimie Physique (EA 4066), Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, 4 Avenue de l' Observatoire, 75270 Paris Cedex 06 (France)

    2010-01-10

    The lidocaine-salol binary system has been investigated by differential scanning calorimetry, direct visual observations, and X-ray powder diffraction, resulting in a temperature-composition phase diagram with a eutectic equilibrium. The eutectic mixture, found at 0.423 {+-} 0.007 lidocaine mole-fraction, melts at 18.2 {+-} 0.5 {sup o}C with an enthalpy of 17.3 {+-} 0.5 kJ mol{sup -1}. This indicates that the liquid phase around the eutectic composition is stable at room temperature. Moreover, the undercooled liquid mixture does not easily crystallize. The present binary mixture exhibits eutectic behavior similar to the prilocaine-lidocaine mixture in the widely used EMLA topical anesthetic preparation.

  19. Surface tension of decane binary and ternary mixtures with eicosane, docosane, and tetracosane

    DEFF Research Database (Denmark)

    Queimada, Antonio; Cao, A.I.; Marrucho, I.M.

    2005-01-01

    -C24H50 and the ternary n-C10H22 + n-C20H42 + n-C24H50 were measured from 293.15 K (or above the solution melting temperature) up to 343.15 K. An average absolute deviation of 1.3% was obtained in comparison with pure component literature data. No mixture information for the reported systems was found......A tensiometer operating on the Wilhelmy plate method was employed to measure liquid-vapor interfacial tensions of three binary mixtures and one ternary mixture of decane with eicosane, docosane, and tetracosane. Tensions of binary mixtures n-C10H22 + n-C20H42, n-C10H22 + n-C22H46, and n-C10H22 + n...

  20. Flash-Point prediction for binary partially miscible aqueous-organic mixtures

    OpenAIRE

    Liaw, Horng-Jang; Chen, Chien Tsun; Gerbaud, Vincent

    2008-01-01

    Flash point is the most important variable used to characterize fire and explosion hazard of liquids. Herein, partially miscible mixtures are presented within the context of liquid-liquid extraction processes and heterogeneous distillation processes. This paper describes development of a model for predicting the flash point of binary partially miscible mixtures of aqueous-organic system. To confirm the predictive efficiency of the derived flash points, the model was verified by comparing the ...

  1. Application of the finite volume method in the simulation of saturated flows of binary mixtures

    International Nuclear Information System (INIS)

    Murad, M.A.; Gama, R.M.S. da; Sampaio, R.

    1989-12-01

    This work presents the simulation of saturated flows of an incompressible Newtonian fluid through a rigid, homogeneous and isotropic porous medium. The employed mathematical model is derived from the Continuum Theory of Mixtures and generalizes the classical one which is based on Darcy's Law form of the momentum equation. In this approach fluid and porous matrix are regarded as continuous constituents of a binary mixture. The finite volume method is employed in the simulation. (author) [pt

  2. Ultrasonic Studies of Molecular Interactions in Organic Binary Liquid Mixtures

    Directory of Open Access Journals (Sweden)

    S. Thirumaran

    2010-01-01

    Full Text Available The ultrasonic velocity, density and viscosity have been measured for the mixtures of 1-alkanols such as 1-propanol and 1-butanol with N-N dimethylformamide (DMF at 303 K. The experimental data have been used to calculate the acoustical parameters namely adiabatic compressibility (β, free length (Lf, free volume (Vf and internal pressure (πi. The excess values of the above parameters are also evaluated and discussed in the light of molecular interaction existing in the mixtures. It is obvious that there is a formation of hydrogen bonding between DMF and 1-alkanols. Further, the addition of DMF causes dissociation of hydrogen bonded structure of 1-alkanols. The evaluated excess values confirm that the molecular association is more pronounced in system-II comparing to the system-I.

  3. Analysis of guest binary mixtures by tert-butylcalix[6]arene using host memory of previously bound guests.

    Science.gov (United States)

    Safina, Goulnaz D; Ziganshin, Marat A; Gubaidullin, Aidar T; Gorbatchuk, Valery V

    2013-02-28

    A new principle of quantitative and qualitative analysis of binary organic mixtures is offered, which is based on an ability of calixarene receptor for specific polymorphic transitions related to the composition of the analyzed guest mixture. The ability of tert-butylcalix[6]arene to remember selectively some guests bound from headspace both of pure liquids and their binary mixtures is used. The image of guest mixture remains written in metastable polymorphs of host after partial or complete guest elimination from clathrates. The memory was read using differential scanning calorimetry as the enthalpy of exothermic polymorphic transition of host collapse. This enthalpy monotonously changes with the variation of guests' ratio in mixture, unlike the enthalpies of endothermic pseudopolymorphic transitions of guest release. So, the composition of volatile binary mixture can be estimated using only one receptor and only one its parameter even in absence of preferential binding from a binary mixture of guests. This is an example of a genuine molecular recognition.

  4. Resistances for heat and mass transfer through a liquid–vapor interface in a binary mixture

    NARCIS (Netherlands)

    Glavatskiy, K.S.; Bedeaux, D.

    2010-01-01

    In this paper we calculate the interfacial resistances to heat and mass transfer through a liquid–vapor interface in a binary mixture. We use two methods, the direct calculation from the actual nonequilibrium solution and integral relations, derived earlier. We verify, that integral relations, being

  5. Self-Propulsion Mechanism of Active Janus Particles in Near-Critical Binary Mixtures

    NARCIS (Netherlands)

    Samin, Sela|info:eu-repo/dai/nl/375362355; van Roij, Rene|info:eu-repo/dai/nl/152978984

    2015-01-01

    Gold-capped Janus particles immersed in a near-critical binary mixture can be propelled using illumination. We employ a nonisothermal diffuse interface approach to investigate the self-propulsion mechanism of a single colloid. We attribute the motion to body forces at the edges of a micronsized

  6. The Effect of Compositional Changes of Binary Mixtures of n-alkane ...

    African Journals Online (AJOL)

    The Effect of Compositional Changes of Binary Mixtures of n-alkane solvents on the Precipitation of Heavy Organics from a Solution of Crude Oil Residue. ... The results have shown that the quantity of HO precipitate decreases with increasing quantity of higher carbon number of n-alkane solvent to a minimum value at 2:1 ...

  7. Sedimentation-diffusion equilibrium of binary mixtures of charged colloids including volume effects

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Lyklema, J.

    2005-01-01

    We describe the sedimentation-diffusion equilibrium of binary mixtures of charged colloids in the presence of small ions and for non-dilute conditions, by extending the work of Biben and Hansen (1994 J. Phys.: Condens. Matter 6 A345). For a monocomponent system, they included a Carnahan-Starling

  8. nth-Nearest neighbour distribution functions of a binary fluid mixture ...

    Indian Academy of Sciences (India)

    Administrator

    Keywords. Nearest neighbour distribution; binary mixture. 1. Introduction. Properties of an interacting many-particle system often depends fundamentally on the influence of the nearest neighbour (NN) particles around a reference particle of interest in pure as well as multi- component fluid systems. For microscopic structural.

  9. Binary mixtures of ionic liquids: a joint approach to investigate their properties and catalytic ability.

    Science.gov (United States)

    D'Anna, Francesca; Marullo, Salvatore; Vitale, Paola; Noto, Renato

    2012-05-14

    The growing interest in the properties and applications of ionic liquids has recently led to research into the possibility of using their binary mixtures. This work reports on the effects of binary mixtures of ionic liquids on the outcome of organic reactions such as the mononuclear rearrangement of heterocycles and the solvatochromic behavior of Nile Red. Binary mixtures formed by ionic liquids differing in the structure of the cation and the anion are taken into account. In particular, ionic liquids such as 1-benzyl-3-butylimidazolium bis(trifluoromethanesulfonyl)imide, 1-(2,3,4,5,6-pentafluorobenzyl)-3-butylimidazolium bis(trifluoromethanesulfonyl)imide, and 1-benzyl-3-butylimidazolium tetrafluoroborate, are studied. To achieve a deep understanding of the properties of ionic-liquid binary mixtures, their three-dimensional organization was analyzed by a combination of resonance light scattering, UV/Vis spectroscopy, and (1)H and (19)F NMR spectroscopy. Data collected herein evidence that the most significant changes in the ionic lattice structure, and consequently the most pronounced effects exerted as solvent media, occur when the studied system involves a blend of different anions. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Modeling diffusion coefficients in binary mixtures of polar and non-polar compounds

    DEFF Research Database (Denmark)

    Medvedev, Oleg; Shapiro, Alexander

    2005-01-01

    The theory of transport coefficients in liquids, developed previously, is tested on a description of the diffusion coefficients in binary polar/non-polar mixtures, by applying advanced thermodynamic models. Comparison to a large set of experimental data shows good performance of the model. Only...

  11. Surface tension of heptane, decane, hexadecane, eicosane, and some of their binary mixtures

    DEFF Research Database (Denmark)

    Rolo, Lara I.; Caco, Ana I.; Queimada, Antonio

    2002-01-01

    Surface tension measurements were performed by the Wilhelmy plate method. Measured systems included pure heptane, decane, hexadecane, eicosane, and some of their binary mixtures at temperatures from 293.15 K to 343.15 K with an average absolute deviation of 1.6%. The results were compared with a ...

  12. Study of surface tension and surface properties of binary alcohol/n-alkyl acetate mixtures.

    Science.gov (United States)

    Rafati, Amir Abbas; Ghasemian, Ensieh

    2008-12-15

    The Butler equation is employed to describe quantitatively the nature, properties, and compositions of surface layers in binary liquid mixtures. Bulk mole fraction, surface molar area, and surface tension of pure components are necessary inputs for this equation. In addition, the UNIFAC group contribution method is applied to account for the nonideality of the bulk liquid as well as that of the surface layer. The average relative error obtained from the comparison of experimental and calculated surface tension values for 12 binary systems is less than 1%. Therefore, the model has good accuracy in comparison with other predictive equations. In addition to finding more information about the surface structure of binary mixtures, surface mole fraction was calculated using relative Gibbs adsorption values and an extended Langmuir model (EL). The obtained results show a good consistency between two models employed, i.e., the Gibbs adsorption model and EL model, based on the UNIFAC method.

  13. The effects of binary UV filter mixtures on the midge Chironomus riparius

    International Nuclear Information System (INIS)

    Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis

    2016-01-01

    Organic ultraviolet (UV) filters are used in a wide variety of products, including cosmetics, to prevent damage from UV light in tissues and industrial materials. Their extensive use has raised concerns about potential adverse effects in human health and aquatic ecosystems that accumulate these pollutants. To increase sun radiation protection, UV filters are commonly used in mixtures. Here, we studied the toxicity of binary mixtures of 4-methylbenzylidene camphor (4MBC), octyl-methoxycinnamate (OMC), and benzophenone-3 (BP-3), by evaluating the larval mortality of Chironomus riparius. Also molecular endpoints have been analyzed, including alterations in the expression levels of a gene related with the endocrine system (EcR, ecdysone receptor) and a gene related with the stress response (hsp70, heat shock protein 70). The results showed that the mortality caused by binary mixtures was similar to that observed for each compound alone; however, some differences in LC50 were observed between groups. Gene expression analysis showed that EcR mRNA levels increased in the presence of 0.1 mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10 mg/L of BP-3 or OMC. In contrast, the hsp70 mRNA levels increased after exposure to the combinations tested of 4MBC and BP-3 or OMC mixtures. These data suggest that 4MBC, BP-3, and OMC may have antagonist effects on EcR gene transcription and a synergistic effect on hsp70 gene activation. This is the first experimental study to show the complex patterned effects of UV filter mixtures on invertebrates. The data suggest that the interactions within these chemicals mixtures are complex and show diverse effects on various endpoints. - Highlights: • Chironomus riparius is sensitive to UV filter binary mixtures. • UV filters binary mixtures show antagonism on survival of 4th instar larvae. • BP-3 and OMC antagonize the stimulatory effect of 4MBC on EcR gene. • 4MBC, OMC, and BP-3 induce hsp70

  14. The effects of binary UV filter mixtures on the midge Chironomus riparius

    Energy Technology Data Exchange (ETDEWEB)

    Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis, E-mail: jlmartinez@ccia.uned.es

    2016-06-15

    Organic ultraviolet (UV) filters are used in a wide variety of products, including cosmetics, to prevent damage from UV light in tissues and industrial materials. Their extensive use has raised concerns about potential adverse effects in human health and aquatic ecosystems that accumulate these pollutants. To increase sun radiation protection, UV filters are commonly used in mixtures. Here, we studied the toxicity of binary mixtures of 4-methylbenzylidene camphor (4MBC), octyl-methoxycinnamate (OMC), and benzophenone-3 (BP-3), by evaluating the larval mortality of Chironomus riparius. Also molecular endpoints have been analyzed, including alterations in the expression levels of a gene related with the endocrine system (EcR, ecdysone receptor) and a gene related with the stress response (hsp70, heat shock protein 70). The results showed that the mortality caused by binary mixtures was similar to that observed for each compound alone; however, some differences in LC50 were observed between groups. Gene expression analysis showed that EcR mRNA levels increased in the presence of 0.1 mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10 mg/L of BP-3 or OMC. In contrast, the hsp70 mRNA levels increased after exposure to the combinations tested of 4MBC and BP-3 or OMC mixtures. These data suggest that 4MBC, BP-3, and OMC may have antagonist effects on EcR gene transcription and a synergistic effect on hsp70 gene activation. This is the first experimental study to show the complex patterned effects of UV filter mixtures on invertebrates. The data suggest that the interactions within these chemicals mixtures are complex and show diverse effects on various endpoints. - Highlights: • Chironomus riparius is sensitive to UV filter binary mixtures. • UV filters binary mixtures show antagonism on survival of 4th instar larvae. • BP-3 and OMC antagonize the stimulatory effect of 4MBC on EcR gene. • 4MBC, OMC, and BP-3 induce hsp70

  15. Chromonic liquid crystalline nematic phase exhibited in binary mixture of two liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Govindaiah, T. N., E-mail: tngovi.phy@gmail.com; Sreepad, H. R. [Post-Graduate Department of Physics, Government College (Autonomous), Mandya-571401 (India); Sridhar, K. N.; Sridhara, G. R.; Nagaraja, N. [Government College for Boys, Kolar-563101 (India)

    2015-06-24

    A binary mixture of abietic acid and orthophosphoric acid (H{sub 3}PO{sub 4}) exhibits co-existence of biphasic region of Nematic+Isotropic (N+I), lyotropic Nematic (ND) and Smectic-G (SmG) phases. The mixture exhibits N+I, N and SmG phases at different concentrations and at different temperatures. Mixtures with all concentrations of abietic acid exhibit I→N+I→N→SmG phases sequentially when the specimen is cooled from its isotropic melt. These phases have been characterized by using differential scanning calorimetric, X-ray diffraction, and optical texture studies.

  16. VISCOSITY OF BINARY NON-ELECTROLYTE LIQUID MIXTURES: PREDICTION AND CORRELATION

    Directory of Open Access Journals (Sweden)

    Mirjana Lj. Kijevčanin

    2008-11-01

    Full Text Available The viscosity of 31 binary liquid mixtures containing diverse groups of organic compounds, determined at atmospheric pressure: alcohols, alkanes (cyclo and aliphatic, esters, aromatics, ketones etc., were calculated using two different approaches, correlative (with Teja-Rice and McAllister models and predictive by group contribution models (UNIFAC-VISCO, ASOG-VISCO and Grunberg-Nissan. The obtained results were analysed in terms of the applied approach and model, the structure of the investigated mixtures, the nature of components of the mixtures and the influence of alkyl chain length of the alcohol molecule.

  17. Studying the Crystallization of Various Polymorphic Forms of Nifedipine from Binary Mixtures with the Use of Different Experimental Techniques.

    Science.gov (United States)

    Madejczyk, O; Kaminska, E; Tarnacka, M; Dulski, M; Jurkiewicz, K; Kaminski, K; Paluch, M

    2017-06-05

    In this paper the crystal growth of nifedipine from pure system and from binary mixtures composed of active substance (API) and two acetylated disaccharides, maltose and sucrose (NIF-acMAL, NIF-acSUC, 5:1 weight ratio), was investigated. Optical snapshots supported by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) measurements showed that mainly β and α forms of nifedipine grow up in all investigated samples. They also revealed that the morphology of growing crystals strongly depends on the presence of modified carbohydrates and temperature conditions. Interestingly, it was found that the activation barrier for the crystal growth of the β polymorph is not affected by acetylated saccharides while the one estimated for the α form changes significantly from 48.5 kJ/mol (pure API) up to 122 kJ/mol (NIF-acMAL system). Moreover, the relationship between the crystal growth rate and structural relaxation times for pure NIF and solid dispersions were analyzed. It turned out that there is a clear decoupling between the crystal growth rate and structural dynamics in both NIF-acMAL and NIF-acSUC binary mixtures. This is in line with recent reports indicating the decoupling phenomenon to be a universal feature of soft matter in the close vicinity of the glass transition temperature.

  18. The effect of individual phosphate emulsifying salts and their selected binary mixtures on hardness of processed cheese spreads

    Directory of Open Access Journals (Sweden)

    František Buňka

    2013-07-01

    Full Text Available Normal 0 false false false CS JA X-NONE The aim of this work was to observe the effects of emulsifying salts composed of trisodium citrate and sodium phosphates with different chain length (disodium phosphate (DSP, tetrasodium diphosphate (TSPP, pentasodium triphosphate (PSTP and sodium salts of polyphosphates with 5 different mean length (n ≈ 5, 9, 13, 20, 28 on hardness of processed cheese spreads. Hardness of processed cheese spreads with selected binary mixtures of the above mentioned salts were also studied. Measurements were performed after 2, 9 and 30 days of storage at 6 °C. Hardness of processed cheese increased with increase in chain length of individually used phosphates.  Majority of applied binary mixtures of emulsifying salts had not significant influence on hardness charges in processed cheese spreads. On the other hand, a combination of phosphates salts (DSP with TSPP was found, which had specific effect on hardness of processed cheese spreads. Textural properties of samples with trisodium citrate were similar compared to samples with DSP.

  19. Evaporative and Convective Instabilities for the Evaporation of a Binary Mixture in a Bilayer System

    Science.gov (United States)

    Guo, Weidong; Narayanan, Ranga

    2006-11-01

    Evaporative convection in binary mixtures arises in a variety of industrial processes, such as drying of paint and coating technology. There have been theories devoted to this problem either by assuming a passive vapor layer or by isolating the vapor fluid dynamics. Previous work on evaporative and convective instabilities in a single component bilayer system suggests that active vapor layers play a major role in determining the instability of the interface. We have investigated the evaporation convection in binary mixtures taking into account the fluid dynamics of both phases. The liquid mixture and its vapor are assumed to be confined between two horizontal plates with a base state of zero evaporation but with linear vertical temperature profile. When the vertical temperature gradient reaches a critical value, the evaporative instability, Rayleigh and Marangoni convection set in. The effects of vapor and liquid depth, various wave numbers and initial composition of the mixture on the evaporative and convective instability are determined. The physics of the instability are explained and detailed comparison is made between the Rayleigh, Marangoni and evaporative convection in pure component and those in binary mixtures.

  20. Toxic effect of metal cation binary mixtures to the seaweed Gracilaria domingensis (Gracilariales, Rhodophyta).

    Science.gov (United States)

    Mendes, Luiz Fernando; Stevani, Cassius Vinicius; Zambotti-Villela, Leonardo; Yokoya, Nair Sumie; Colepicolo, Pio

    2014-01-01

    The macroalga Gracilaria domingensis is an important resource for the food, pharmaceutical, cosmetic, and biotechnology industries. G. domingensis is at a part of the food web foundation, providing nutrients and microelements to upper levels. As seaweed storage metals in the vacuoles, they are considered the main vectors to magnify these toxic elements. This work describes the evaluation of the toxicity of binary mixtures of available metal cations based on the growth rates of G. domingensis over a 48-h exposure. The interactive effects of each binary mixture were determined using a toxic unit (TU) concept that was the sum of the relative contribution of each toxicant and calculated using the ratio between the toxicant concentration and its endpoint. Mixtures of Cd(II)/Cu(II) and Zn(II)/Ca(II) demonstrated to be additive; Cu(II)/Zn(II), Cu(II)/Mg(II), Cu(II)/Ca(II), Zn(II)/Mg(II), and Ca(II)/Mg(II) mixtures were synergistic, and all interactions studied with Cd(II) were antagonistic. Hypotheses that explain the toxicity of binary mixtures at the molecular level are also suggested. These results represent the first effort to characterize the combined effect of available metal cations, based on the TU concept on seaweed in a total controlled medium. The results presented here are invaluable to the understanding of seaweed metal cation toxicity in the marine environment, the mechanism of toxicity action and how the tolerance of the organism.

  1. Measurement and modelling of hydrogen bonding in 1-alkanol plus n-alkane binary mixtures

    DEFF Research Database (Denmark)

    von Solms, Nicolas; Jensen, Lars; Kofod, Jonas L.

    2007-01-01

    Two equations of state (simplified PC-SAFT and CPA) are used to predict the monomer fraction of 1-alkanols in binary mixtures with n-alkanes. It is found that the choice of parameters and association schemes significantly affects the ability of a model to predict hydrogen bonding in mixtures, eve...... studies, which is clarified in the present work. New hydrogen bonding data based on infrared spectroscopy are reported for seven binary mixtures of alcohols and alkanes. (C) 2007 Elsevier B.V. All rights reserved....... though pure-component liquid densities and vapour pressures are predicted equally accurately for the associating compound. As was the case in the study of pure components, there exists some confusion in the literature about the correct interpretation and comparison of experimental data and theoretical...

  2. Toxicity of a binary mixture on Daphnia magna: biological effects of uranium and selenium isolated and in mixture

    International Nuclear Information System (INIS)

    Zeman, F.

    2008-10-01

    Among the multiple substances that affect freshwater ecosystems, uranium and selenium are two pollutants found worldwide in the environment, alone and in mixture. The aim of this thesis work was to investigate the effect of uranium and selenium mixture on daphnia (Daphnia magna). Studying effects of a mixture requires the assessment of the effect of single substances. Thus, the first experiments were performed on single substance. Acute toxicity data were obtained: EC 50 48h = 0, 39±0, 04 mg.L -1 for uranium and EC 50 48h 1, 86±0, 85 mg.L -1 for selenium. Chronic effects were also studied. Data on fecundity showed an EC 10 reproduction of 14±7 μg. L -1 for uranium and of 215±25 μg. L -1 for selenium. Uranium-selenium mixture toxicity experiments were performed and revealed an antagonistic effect. This study further demonstrates the importance of taking into consideration different elements in binary mixture studies such as the choice of reference models (concentration addition or independent action), statistical method, time exposure and endpoints. Using integrated parameters like energy budget was shown to be an interesting way to better understand interactions. An approach including calculation of chemical speciation in the medium and bioaccumulation measurements in the organism permits assumptions to be made on the nature of possible interactions between mixture components (toxico-dynamic et toxico-kinetic interactions). (author)

  3. The viscous slip coefficient for a binary gas mixture

    International Nuclear Information System (INIS)

    Knackfuss, Rosenei F.

    2009-01-01

    For a moderately small rarefaction, the Navier-Stokes equations are associated with of the slip boundary condition, i e the velocity of the gas on the surface is different from zero at the surface, but its tangential component, depends on the profile distribution of velocity and temperature near the surface. The slip for the velocity profile near the surface is determined by the viscous slip coefficient. The viscous slip coefficient can be determined solving the equation of the Boltzmann or the kinetic equations which are simplified forms of Boltzmann equation with respect to the operator of collision. For this reason, in this work is presented the derivation of the solution of the viscous-slip problem for the mixtures of two noble gases, based on the McCormack model that is developed in terms of an analytical version of the discrete ordinates method has been applied with excellent results, to derive solutions to several problems in rarefied gas dynamics. To complete the problem, include the gas-surface interaction, based on the model of Cercignani-Lampis, which, unlike the model of Maxwell, has two accommodation coefficients: the coefficient of accommodation of tangential moment and the energy accommodation coefficient kinetics due to normal component of velocity. (author)

  4. Renormalization group theory for fluids including critical region. II. Binary mixtures

    Science.gov (United States)

    Mi, Jianguo; Zhong, Chongli; Li, Yi-Gui

    2005-06-01

    In our previous work [J. Mi, C. Zhong, Yi.-G. Li, J. Chen, Chem. Phys., 305 (2004) 37-45], an equation of state (EOS) based on the combination of renormalization group theory (RG) and the statistical associating fluid theory (SAFT) was proposed for describing pure fluid thermodynamic properties both inside and outside critical region, which was extended to binary mixtures in this work. A variety of binary systems were considered in this work, including nonpolar/nonpolar, nonpolar/polar, nonpolar/associating and associating/associating mixtures. Two adjustable parameters are required by the new EOS for each binary system, which are obtained by fitting the vapor-liquid equilibria (VLE) data at one temperature. The calculated results show that the new EOS gives satisfactory predictions for critical properties as well as the VLE at other temperatures, both inside and outside critical region. This work demonstrates that RG theory is a very useful tool for accurately describing fluid properties inside critical region, and a combination of it with SAFT EOS can lead to a new EOS possessing the advantages of both theories, applicable to the whole phase equilibrium region of binary mixtures.

  5. Measurement and correlation of solubility of cefmenoxime hydrochloride in pure solvents and binary solvent mixtures

    International Nuclear Information System (INIS)

    Wang, Jinxiu; Xie, Chuang; Yin, Qiuxiang; Tao, Linggang; Lv, Jun; Wang, Yongli; He, Fang; Hao, Hongxun

    2016-01-01

    Highlights: • Solubility of cefmenoxime hydrochloride in pure and binary solvents was determined. • The experimental solubility data were correlated by thermodynamic models. • A model was employed to calculate the melting temperature of cefmenoxime hydrochloride. • Mixing thermodynamic properties of cefmenoxime hydrochloride were calculated. - Abstract: The solubility of cefmenoxime hydrochloride in pure solvents and binary solvent mixtures was measured at temperatures from (283.15 to 313.15) K by using the UV spectroscopic method. The results reveal that the solubility of cefmenoxime hydrochloride increases with increasing temperature in all solvent selected. The solubility of cefmenoxime hydrochloride reaches its maximum value when the mole fraction of isopropanol is 0.2 in the binary solvent mixtures of (isopropanol + water). The modified Apelblat equation and the NRTL model were successfully used to correlate the experimental solubility in pure solvents while the modified Apelblat equation, the CNIBS/R–K model and the Jouyban–Acree model were applied to correlate the solubility in binary solvent mixtures. In addition, the mixing thermodynamic properties of cefmenoxime hydrochloride in different solvents were also calculated based on the NRTL model and experimental solubility data.

  6. Prediction of the Flash Point of Binary and Ternary Straight-Chain Alkane Mixtures

    Directory of Open Access Journals (Sweden)

    X. Li

    2014-01-01

    Full Text Available The flash point is an important physical property used to estimate the fire hazard of a flammable liquid. To avoid the occurrence of fire or explosion, many models are used to predict the flash point; however, these models are complex, and the calculation process is cumbersome. For pure flammable substances, the research for predicting the flash point is systematic and comprehensive. For multicomponent mixtures, especially a hydrocarbon mixture, the current research is insufficient to predict the flash point. In this study, a model was developed to predict the flash point of straight-chain alkane mixtures using a simple calculation process. The pressure, activity coefficient, and other associated physicochemical parameters are not required for the calculation in the proposed model. A series of flash points of binary and ternary mixtures of straight-chain alkanes were determined. The results of the model present consistent experimental results with an average absolute deviation for the binary mixtures of 0.7% or lower and an average absolute deviation for the ternary mixtures of 1.03% or lower.

  7. Binary mixtures of hydrogen-bonded ferroelectric liquid crystals. Thermal span enhancement in smectic X* phase

    Energy Technology Data Exchange (ETDEWEB)

    Sangameswari, Gopal; Prabu, Nataraj Pongali Sathya; Madhu Mohan, Mathukumalli Lakshmi Narayana [Bannari Amman Institute of Technology, Sathyamangalam (India). Liquid Crystal Research Laboratory (LCRL)

    2015-07-01

    Thermotropic hydrogen-bonded ferroelectric binary liquid crystal mixtures comprising of N-carbamyl-l-glutamic acid (CGA) and p-n-alkyloxy benzoic acids (BAO) are investigated. Variation in the molar proportion of X and Y (where X=CGA+5BAO and Y=CGA+9BAO, CGA+10BAO, CGA+11BAO, and CGA+12BAO) comprising of four series yielded 36 binary mixtures. Optical and thermal properties of these mixtures are meticulously studied in the present article. In addition to the traditional phases, a novel smectic ordering namely smectic X* is observed in all the four series. The aim of the investigation is to obtain abundance occurrence of smectic X* with a large thermal span, and hence, the proportions of the binary mixtures are so chosen that the prelude task is accomplished. Optical tilt angle in smectic X* and smectic C* phases is experimentally determined, and a theoretical fit is performed. Phase diagrams of the four series are constructed from the data obtained from the differential scanning calorimetry and correlated with the phases recorded by the polarising optical microscope studies. Thermal stability factor and thermal equilibrium are also premeditated.

  8. Excess enthalpies and (vapour + liquid) equilibrium data for the binary mixtures of dimethylsulphoxide with ketones

    International Nuclear Information System (INIS)

    Radhamma, M.; Venkatesu, P.; Rao, M.V. Prabhakara; Prasad, D.H.L.

    2007-01-01

    Excess enthalpies (H E ), at ambient pressure and T = 298.15 K, have been measured by using a solution calorimeter for the binary liquid mixtures of dimethyl sulphoxide (DMSO) with ketones, as a function of composition. The ketones chosen in the present investigation were methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and cyclohexanone (CH). The H E values are positive over the entire composition range for the three binary mixtures. Furthermore, the (vapour + liquid) equilibrium (VLE) was measured at 715 Torr for these mixtures, of different compositions, with the help of Swietoslawski-ebulliometer. The experimental temperature-mole fraction (t-x) data were used to compute Wilson parameters and then used to calculate the equilibrium vapour-phase compositions as well as the theoretical points for these binary mixtures. These Wilson parameters are used to calculate activity coefficients (γ) and these in turn to calculate excess Gibbs free energy (G E ). The intermolecular interactions and structural effects were analyzed on the basis of the measured and derived properties

  9. Kinetic Investigation of Styrene Free Radical Polymerization by Using Binary Mixtures of Monofunctional Initiators

    OpenAIRE

    Farshid Ziaee; Mona Basiri; Mehdi Nekoomanesh; Ardeshir Khazaie

    2013-01-01

    Polymerization of styrene in presence of two monofunctional initiators is studied kinetically in an ampoule scale. Polymerizations were ceased at different conversions for each ampoule while the temperature was increased almost linearly during the reaction. Three different initiator mixtures were used. The first mixtures were composed of benzoil peroxide (BPO) and t-butyl perbenzoate (TBPB) with various molar ratios and temperature programs. The second and third series were performed on mixtu...

  10. Interfacial tensions of binary mixtures of ethanol with octane, decane, dodecane, and tetradecane

    International Nuclear Information System (INIS)

    Mejia, Andres; Cartes, Marcela; Segura, Hugo

    2011-01-01

    Highlights: → Experimental interfacial tensions in binary mixtures with aneotropic behavior. → Experimental interfacial tensions for ethanol + hydrocarbon mixtures. → Aneotropic displacement in ethanol mixtures. - Abstract: This contribution is devoted to the experimental characterization of interfacial tensions of a representative group of binary mixtures pertaining to the (ethanol + linear hydrocarbon) series (i.e. octane, decane, dodecane, and tetradecane). Experimental measurements were isothermically performed using a maximum differential bubble pressure technique, which was applied over the whole mole fraction range and over the temperature range 298.15 K < T/K < 318.15 K. Experimental results show that the interfacial tensions of (ethanol + octane or decane) negatively deviate from the linear behavior and that sharp minimum points on concentration, or aneotropes, are observed for each isotherm. The interfacial tensions of (ethanol + dodecane or tetradecane), in turn, are characterized by combined deviations from the linear behavior, and inflecting behavior observed on concentration for each isotherm. The experimental evidence also shows that these latter mixtures are close to exhibit aneotropy. For the case of (ethanol + octane or decane) mixtures, aneotropy was clearly induced by the similarity of the interfacial tension values of the constituents. The inflecting behavior of the interfacial tensions of (ethanol + dodecane or tetradecane), in turn, was observed in the vicinity of the coordinates of the critical point of these mixtures, thus pointing to the fact that the quasi-aneotropic singularity that affects these mixtures was provoked by the proximity of an immiscibility gap of the liquid phase. Finally, the experimental data of interfacial tensions were smoothed with the Scott-Myers expansion, from which it is possible to conclude that the observed aneotropic concentrations weakly depend on temperature for all the analyzed mixtures.

  11. Interaction between natural antioxidants derived from cinnamon and cocoa in binary and complex mixtures.

    Science.gov (United States)

    Muhammad, Dimas Rahadian Aji; Praseptiangga, Danar; Van de Walle, Davy; Dewettinck, Koen

    2017-09-15

    Cinnamon and cocoa are known to be valuable sources of bioactive phytochemicals, mainly the polyphenols. This paper investigates the potential antioxidant activity of cinnamon and cocoa extract and the interaction of their mixtures by various in vitro tests. Moreover, the combination effect of their constituents in a binary mixture was studied. Two representative active compounds of chocolate (epicatechin, catechin) were combined with seven of cinnamon (gallic acid, tannic acid, quercetin, sinapic acid, cinnamic acid, eugenol and cinnamaldehyde) in multilevel ratios. The results indicate that the addition of the cinnamon extract significantly increased the antioxidant activity of the cocoa extract. The interaction ranged from synergetic to antagonistic. The interaction was less synergetic when cinnamon extract was added in higher proportion. The interaction of their constituents substantially influenced the antioxidant activity of the mixture and was dependent on the ratio. The kinetics' study could elucidate how the polyphenols work in a mixture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Influence of adhesion on random loose packings of binary micro-particle mixtures

    Science.gov (United States)

    Liu, Wenwei; Chen, Sheng; Li, Shuiqing; Key Laboratory for Thermal Science; Power Engineering of Ministry of Education Team

    2017-11-01

    Binary adhesive packings of microspheres with certain size ratios are investigated via a 3D discrete-element method specially developed with adhesive contact mechanics. We found a novel phenomenon that the packing fraction of the binary adhesive mixtures decreases monotonically with the increase of the amount of small components. It was further divulged that this behavior results from the competition between a geometrical filling effect and an adhesion effect. The positive geometrical filling effect only depends on the size ratio, while a dimensionless adhesion parameter Ad is employed to characterize the negative adhesion effect, which comes to its maximum at Ad 10 . Structural properties, including contact network, partial coordination number, radial distribution function and angular distribution function, are analyzed in order to give a better understanding of such adhesive binary packings. National Key Basic Research Program of China (No. 2013CB228506) and National Natural Science Foundation of China (No. 51390491).

  13. Bone regeneration in rat calvarial defects implanted with fibrous scaffolds composed of a mixture of silicate and borate bioactive glasses.

    Science.gov (United States)

    Gu, Yifei; Huang, Wenhai; Rahaman, Mohamed N; Day, Delbert E

    2013-11-01

    Previous studies have evaluated the capacity of porous scaffolds composed of a single bioactive glass to regenerate bone. In the present study, scaffolds composed of a mixture of two different bioactive glasses (silicate 13-93 and borate 13-93B3) were created and evaluated for their response to osteogenic MLO-A5 cells in vitro and their capacity to regenerate bone in rat calvarial defects in vivo. The scaffolds, which have similar microstructures (porosity=58-67%) and contain 0, 25, 50 and 100 wt.% 13-93B3 glass, were fabricated by thermally bonding randomly oriented short fibers. The silicate 13-93 scaffolds showed a better capacity to support cell proliferation and alkaline phosphatase activity than the scaffolds containing borate 13-93B3 fibers. The amount of new bone formed in the defects implanted with the 13-93 scaffolds at 12 weeks was 31%, compared to values of 25, 17 and 20%, respectively, for the scaffolds containing 25, 50 and 100% 13-93B3 glass. The amount of new bone formed in the 13-93 scaffolds was significantly higher than in the scaffolds containing 50 and 100% 13-93B3 glass. While the 13-93 fibers were only partially converted to hydroxyapatite at 12 weeks, the 13-93B3 fibers were fully converted and formed a tubular morphology. Scaffolds composed of an optimized mixture of silicate and borate bioactive glasses could provide the requisite architecture to guide bone regeneration combined with a controllable degradation rate that could be beneficial for bone and tissue healing. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  14. Thermo-acoustical molecular interaction study in binary mixtures of glycerol and ethylene glycol

    Science.gov (United States)

    Kaur, Kirandeep; Juglan, K. C.; Kumar, Harsh

    2017-07-01

    Ultrasonic velocity, density and viscosity are measured over the entire composition range for binary liquid mixtures of glycerol (CH2OH-CHOH-CH2OH) and ethylene glycol (HOCH2CH2OH) at different temperatures and constant frequency of 2MHz using ultrasonic interferometer, specific gravity bottle and viscometer respectively. Measured experimental values are used to obtained various acoustical parameters such as adiabatic compressibility, acoustic impedance, intermolecular free length, relaxation time, ultrasonic attenuation, effective molar weight, free volume, available volume, molar volume, Wada's constant, Rao's constant, Vander Waal's constant, internal pressure, Gibb's free energy and enthalpy. The variation in acoustical parameters are interpreted in terms of molecular interactions between the components of molecules of binary liquid mixtures.

  15. Excess molar enthalpies for binary mixtures of different amines with water

    International Nuclear Information System (INIS)

    Zhang, Ruilei; Chen, Jian; Mi, Jianguo

    2015-01-01

    Highlights: • Isothermal excess molar enthalpies for binary mixtures of different amines with water. • The Redlich–Kister equation and the NRTL model was used to fit the experimental data. • The excess molar enthalpies were discussed with different structures of amines. - Abstract: The isothermal excess molar enthalpies for binary mixtures of different amines with water were measured with a C-80 Setaram calorimeter. The experimental results indicate that the excess molar enthalpy is related to the molecular structure. The experimental excess molar enthalpies were satisfactorily fitted with the Redlich–Kister equation. They were also used to test the suitability of the NRTL model, and the deviations are a little larger than the R–K equation

  16. Viscosities of binary mixtures of toluene with butan-1-ol and 2-methylpropan-2-ol

    Directory of Open Access Journals (Sweden)

    VASILE DUMITRESCU

    2005-11-01

    Full Text Available The viscosities of binary liquid mixtures of toluene with butan-1-ol and 2-methylpropan-2-ol have been determined at 298.15, 303.15, 308.15, 313.15 and 318.15 K over the whole concentration range. The Hind, Grunberg–Nissan, Wijk, Auslander and McAllister models were used to calculate the viscosity coefficients and these were compared with the experimental data for the mixtures. Excess viscosities were also calculated and fitted to the Redlich–Kister equation. Various thermodynamic properties of viscous flow activation were determined and their variations with composition are discussed.

  17. Solubilities of benzoic acid in binary (benzyl alcohol + benzaldehyde) solvent mixtures

    International Nuclear Information System (INIS)

    Wang, Hui; Wang, Qinbo; Xiong, Zhenhua; Chen, Chuxiong; Shen, Binwei

    2015-01-01

    Highlights: • Solubilities of benzoic acid in (benzyl alcohol + benzaldehyde) mixtures were measured at 1 atm. • The experimental temperature ranges at (298.35 to 355.65) K. • Effects of benzyl alcohol mass concentration at (0.00 to 1.00) on the solubilities of benzoic acid were studied. • The experimental data were correlated with NRTL model. • Thermodynamic functions of dissolution of benzoic acid in (benzyl alcohol + benzaldehyde) mixtures were discussed. - Abstract: The solubility of benzoic acid in binary (benzyl alcohol + benzaldehyde) solvent mixtures was measured at temperature from (298.35 to 355.65) K and atmospheric pressure. The measured solubility increases with the increasing temperature at constant solvent composition. The effects of mass fraction benzaldehyde in the solvent mixtures at (0.0 to 1.00) on the solubility were studied. The measured solubility decreases with the increasing mass fraction of benzaldehyde. The experimental results were correlated with the non-random two-liquid (NRTL) equations, and good agreement between the correlated and the experimental values was obtained. Thermodynamic functions for the solution of benzoic acid in binary (benzyl alcohol + benzaldehyde) solvent mixtures were calculated with the van’t Hoff plot. The apparent dissolution Gibbs free energy change was also calculated

  18. A quantitative analysis on latent heat of an aqueous binary mixture.

    Science.gov (United States)

    Han, Bumsoo; Choi, Jeung Hwan; Dantzig, Jonathan A; Bischof, John C

    2006-02-01

    The latent heat during phase change of water-NaCl binary mixture was measured using a differential scanning calorimeter, and the magnitude for two distinct phase change events, water/ice and eutectic phase change, were analyzed considering the phase change characteristics of a binary mixture. During the analysis, the latent heat associated with each event was calculated by normalizing the amount of each endothermic peak with only the amount of sample participating in each event estimated from the lever rule for the phase diagram. The resulting latent heat of each phase change measured is 303.7 +/- 2.5 J/g for water/ice phase change, and 233.0 +/- 1.6 J/g for eutectic phase change, respectively regardless of the initial concentration of mixture. Although the latent heats of water/ice phase change in water-NaCl mixtures are closely correlated, further study is warranted to investigate the reason for smaller latent heat of water/ice phase change than that in pure water (335 J/g). The analysis using the lever rule was extended to estimate the latent heat of dihydrate as 115 J/g with the measured eutectic and water/ice latent heat values. This new analysis based on the lever rule will be useful to estimate the latent heat of water-NaCl mixtures at various concentrations, and may become a framework for more general analysis of latent heat of various biological solutions.

  19. Kinetic Investigation of Styrene Free Radical Polymerization by Using Binary Mixtures of Monofunctional Initiators

    Directory of Open Access Journals (Sweden)

    Farshid Ziaee

    2013-01-01

    Full Text Available Polymerization of styrene in presence of two monofunctional initiators is studied kinetically in an ampoule scale. Polymerizations were ceased at different conversions for each ampoule while the temperature was increased almost linearly during the reaction. Three different initiator mixtures were used. The first mixtures were composed of benzoil peroxide (BPO and t-butyl perbenzoate (TBPB with various molar ratios and temperature programs. The second and third series were performed on mixtures of BPO and α,α'-azobisisobutyronitrile (AIBN and AIBN with TBPB, respectively. The experimental results for these series revealed thatincreasing the percentage of TBPB in the initiator mixtures at the same reaction temperature intervals enhanced polymerization rate and molecular weight of the resulting polymers. On the other hand the results from the second series indicated that reducing AIBN in the mixture would have reduction effect on the reaction temperatureintervals while both conversion and the polymer molecular weight are increased

  20. Control of Native Spoilage Yeast on Dealcoholized Red Wine by Preservatives Alone and in Binary Mixtures.

    Science.gov (United States)

    Sánchez-Rubio, Marta; Guerrouj, Kamal; Taboada-Rodríguez, Amaury; López-Gómez, Antonio; Marín-Iniesta, Fulgencio

    2017-09-01

    In order to preserve a commercial dealcoholized red wine (DRW), a study with 4 preservatives and binary mixtures of them were performed against 2 native spoilage yeasts: Rhodotorula mucilaginosa and Saccharomyces cerevisiae. Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) for potassium sorbate, sodium benzoate, sodium metabisulfite and dimethyl dicarbonate (DMDC) were evaluated in DRW stored at 25 °C. MICs of potassium sorbate and sodium metabisulfite were 250 and 60 mg/kg, respectively for both target strains. However for sodium benzoate, differences between yeasts were found; R. mucilaginosa was inhibited at 125 mg/kg, while S. cerevisiae at 250 mg/kg. Regarding MFC, differences between strains were only found for sodium metabisulfite obtaining a MFC of 500 mg/kg for R. mucilaginosa and a MFC of 250 mg/kg for S. cerevisiae. Potassium sorbate and sodium benzoate showed the MFC at 1000 mg/kg and DMDC at 200 mg/kg. Regarding the effect of binary mixtures the Fractional Fungicidal Concentration Index (FFC i ) methodology showed that binary mixtures of 100 mg/kg DMDC/200 mg/kg potassium sorbate (FFC i = 0.7) and 50 mg/kg DMDC / 400 mg/kg sodium benzoate (FFC i = 0.65) have both synergistic effect against the 2 target strains. These binary mixtures can control the growth of spoilage yeasts in DRW without metabisulfite addition. The results of this work may be important in preserving the health of DRW consumers by eliminating the use of metabisulfite and reducing the risk of growth of R. mucilagosa, recently recognized as an emerging pathogen. © 2017 Institute of Food Technologists®.

  1. NMR study of thallium(I) ions in molten binary mixtures of nitrates and chlorides

    International Nuclear Information System (INIS)

    Nakamura, Yoshio; Kitazawa, Yukiharu; Shimoji, Mitsuo; Shimokawa, Shigezo.

    1983-01-01

    The chemical shifts of 205 Tl NMR in molten binary mixtures of nitrates and those of chlorides have been measured as a function of composition and temperature. The shifts increase in the diamagnetic direction with decreasing the size of foreign cations and increase in the paramagnetic direction with increasing temperature. These results are interpreted by changes in the overlap of orbitals of the Tl + ion and the anion, which depend upon composition and temperature. (author)

  2. Potentiometric pKa Determination of Piroxicam and Tenoxicam in Acetonitrile-Water Binary Mixtures

    OpenAIRE

    Çubuk Demiralay, Ebru; Yılmaz, Hülya

    2012-01-01

    Abstract: Ionization constant (pKa) is one among the parameter to be estimated with accuracy, irrespective of solubility constraints. In the present study, acid-base behaviour of the piroxicam and tenoxicam was studied. By using the potentiometric method, pKa values of piroxicam and tenoxicam have been determined in different percentage of acetonitrile-water binary mixtures (acetonitrile content between 30 and 45% in volume). Aqueous pKa values of these compounds were calculated by mole fract...

  3. Ethanolamines as Corrosion Inhibitors for Zinc in (HNO3+H2SO4 Binary Acid Mixture

    Directory of Open Access Journals (Sweden)

    R. T. Vashi

    2010-01-01

    Full Text Available This work deals with the study of corrosion behaviour for zinc in (HNO3+ H2SO4 binary acid mixture containing ethanolamines. Corrosion rate increases with concentration of acid and temperature. At constant acid concentration, the inhibition efficiency of ethanolamines increases with the inhibitor concentration. Value of ΔGa increases and inhibition decreases with temperature. The mode of inhibition action appears to be chemisorption.

  4. Unusual behaviour of binary mixtures of ferroelectric and antiferroelectric liquid crystals with three chiral centres

    Czech Academy of Sciences Publication Activity Database

    Glogarová, Milada; Novotná, Vladimíra; Kašpar, Miroslav; Hamplová, Věra

    2002-01-01

    Roč. 10, č. 1 (2002), s. 47-52 ISSN 1230-3402 R&D Projects: GA ČR GA202/99/1120 Institutional research plan: CEZ:AV0Z1010914 Keywords : binary mixture * ferroelectric phase * antiferroelectric phase * re-entrant ferroelectric phase * dielectric spectroscopy * soft anti-phase mode Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.466, year: 2002

  5. Non-linearity parameter of binary liquid mixtures at elevated pressures

    Indian Academy of Sciences (India)

    In the present investigation an attempt in this field has been made and B/A is calculated for four binary liquid mixtures at T = 303.15 K over a wide range of pressure. (ranging from 0.1 to 80 Mpa). In this context, Tong and Dong equation has been used to calculate the B/A values. Scarcity of experimental data and its variation ...

  6. Viscous slip coefficients for binary gas mixtures measured from mass flow rates through a single microtube

    OpenAIRE

    Yamaguchi, H.; Takamori, K.; Perrier, P.; Graur, I.; Matsuda, Y.; Niimi, T.

    2016-01-01

    The viscous slip coefficient for helium-argon binary gas mixture is extracted from the experimental values of the mass flow rate through a microtube. The mass flow rate is measured by the constant-volume method. The viscous slip coefficient was obtained by identifying the measured mass flow rate through a microtube with the corresponding analytical expression, which is a function of the Knudsen number. The measurements were carried out in the slip flow regime where the first-order slip bounda...

  7. Experimental vapor-liquid equilibria data for binary mixtures of xylene isomers

    Directory of Open Access Journals (Sweden)

    W.L. Rodrigues

    2005-09-01

    Full Text Available Separation of aromatic C8 compounds by distillation is a difficult task due to the low relative volatilities of the compounds and to the high degree of purity required of the final commercial products. For rigorous simulation and optimization of this separation, the use of a model capable of describing vapor-liquid equilibria accurately is necessary. Nevertheless, experimental data are not available for all binaries at atmospheric pressure. Vapor-liquid equilibria data for binary mixtures were isobarically obtained with a modified Fischer cell at 100.65 kPa. The vapor and liquid phase compositions were analyzed with a gas chromatograph. The methodology was initially tested for cyclo-hexane+n-heptane data; results obtained are similar to other data in the literature. Data for xylene binary mixtures were then obtained, and after testing, were considered to be thermodynamically consistent. Experimental data were regressed with Aspen Plus® 10.1 and binary interaction parameters were reported for the most frequently used activity coefficient models and for the classic mixing rules of two cubic equations of state.

  8. Viscosity of binary mixtures of 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid with four organic solvents

    International Nuclear Information System (INIS)

    Ciocirlan, Oana; Croitoru, Oana; Iulian, Olga

    2016-01-01

    Highlights: • Viscosities of four binary mixtures of [Emim][BF4] with organic solvents. • Viscosity models based on Eyring’s theory. • Excess functions calculated. • Data for binaries new in the literature, except for system with DMSO. - Abstract: This paper reports experimental values of dynamic viscosity for four binary systems of 1-ethyl-3-methylimidazolium tetrafluoroborate, [Emim][BF4], with dimethyl sulfoxide (DMSO), acetonitrile (ACN), ethylene glycol (EG) and 1,4-dioxane over the temperature ranges from 293.15 K to 353.15 K at p = 0.1 MPa. All binary mixtures were completely miscible over the entire range of mole fraction, except the system with 1,4-dioxane. The viscosity results have been correlated by the one parameter Grunberg–Nissan and Fang and He equations and the two-parameter McAllister, Eyring-UNIQUAC, Eyring-NRTL and Eyring-Wilson models and the results were compared. Additionally, the viscosity deviations, Δη, and the excess Gibbs energy of activation for viscous flow, G ∗E , were calculated and fitted to the Redlich–Kister equation. The results show that all Δη values are negative over the whole composition range and the G ∗E values are positive, except for the system with EG. The results of the excess functions are discussed in terms of molecular interactions.

  9. Implementation of an ultrasonic instrument for simultaneous mixture and flow analysis of binary gas systems

    Energy Technology Data Exchange (ETDEWEB)

    Alhroob, M.; Boyd, G.; Hasib, A.; Pearson, B.; Srauss, M.; Young, J. [Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019, (United States); Bates, R.; Bitadze, A. [School of Physics and Astronomy, University of Glasgow, G12 8QQ, (United Kingdom); Battistin, M.; Berry, S.; Bonneau, P.; Botelho-Direito, J.; Bozza, G.; Crespo-Lopez, O.; DiGirolamo, B.; Favre, G.; Godlewski, J.; Lombard, D.; Zwalinski, L. [CERN, 1211 Geneva 23, (Switzerland); Bousson, N.; Hallewell, G.; Mathieu, M.; Rozanov, A. [Centre de Physique des Particules de Marseille, 163 Avenue de Luminy, 13288 Marseille Cedex 09, (France); Deterre, C.; O' Rourke, A. [Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22607 Hamburg, (Germany); Doubek, M.; Vacek, V. [Czech Technical University, Technick 4, 166 07 Prague 6, (Czech Republic); Degeorge, C. [Physics Department, Indiana University, Bloomington, IN 47405, (United States); Katunin, S. [B.P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 St. Petersburg, (Russian Federation); Langevin, N. [Institut Universitaire de Technologie of Marseille, University of Aix-Marseille, 142 Traverse Charles Susini, 13013 Marseille, (France); McMahon, S. [Rutherford Appleton Laboratory - Science and Technology Facilities Council, Harwell Science and Innovation Campus, Didcot OX11 OQX, (United Kingdom); Nagai, K. [Department of Physics, Oxford University, Oxford OX1 3RH, (United Kingdom); Robinson, D. [Department of Physics and Astronomy, University of Cambridge, (United Kingdom); Rossi, C. [INFN - Genova, Via Dodecaneso 33, 16146 Genova, (Italy)

    2015-07-01

    Precision ultrasonic measurements in binary gas systems provide continuous real-time monitoring of mixture composition and flow. Using custom micro-controller-based electronics, we have developed an ultrasonic instrument, with numerous potential applications, capable of making continuous high-precision sound velocity measurements. The instrument measures sound transit times along two opposite directions aligned parallel to - or obliquely crossing - the gas flow. The difference between the two measured times yields the gas flow rate while their average gives the sound velocity, which can be compared with a sound velocity vs. molar composition look-up table for the binary mixture at a given temperature and pressure. The look-up table may be generated from prior measurements in known mixtures of the two components, from theoretical calculations, or from a combination of the two. We describe the instrument and its performance within numerous applications in the ATLAS experiment at the CERN Large Hadron Collider (LHC). The instrument can be of interest in other areas where continuous in-situ binary gas analysis and flowmetry are required. (authors)

  10. Binary mixture micellar systems of F127 and P123 for griseofulvin solubilisation

    Directory of Open Access Journals (Sweden)

    Lillian Maria Uchôa Dutra

    2015-10-01

    Full Text Available Abstract Pluronics® molecules self-assemble in aqueous solution providing a core/shell architecture that improves the solubility of hydrophobic drugs. Binary mixtures of Pluronics® have been studied as drug nanocarriers in order to combine their advantages, like high colloidal stability, small particle size and good solubilisation capacity (Scp. In this work we studied Pluronics® binary mixture, P123 and F127, as nanocarriers of the hydrophobic drug griseofulvin. P123 (E21P67E21 shows a relative good Scp, whereas F127 (E98P67E98 shows a good colloidal stability. According to data, these binary mixtures form stables nano-sized comicelles in aqueous solution. The Scp of the P123/F127 systems at 25 and 37 °C was monitored by UV/Visible spectroscopy, showing good results at both temperatures, as would be expected, since P123/F127 have similar length hydrophobic block. Hydrophobic-dependence and temperature-responsive of the systems were evaluated by CMC, particle size and colloidal stability. Hence, stables P123/F127 comicelles may have potencial as hydrophobic drug delivery.

  11. Noble gas binary mixtures for gas-cooled reactor power plants

    International Nuclear Information System (INIS)

    El-Genk, Mohamed S.; Tournier, Jean-Michel

    2008-01-01

    This paper examines the effects of using noble gases and binary mixtures as reactor coolants and direct closed Brayton cycle (CBC) working fluids on the performance of terrestrial nuclear power plants and the size of the turbo-machines. While pure helium has the best transport properties and lowest pumping power requirement of all noble gases and binary mixtures, its low molecular weight increases the number of stages of the turbo-machines. The heat transfer coefficient for a He-Xe binary mixture having a molecular weight of 15 g/mole is 7% higher than that of helium, and the number of stages in the turbo-machines is 24-30% of those for He working fluid. However, for the same piping and heat exchange components design, the loop pressure losses with He-Xe are ∼3 times those with He. Consequently, for the same reactor exit temperature and pressure losses in piping and heat exchange components, the higher pressure losses in the nuclear reactor decrease the net peak efficiency of the plant with He-Xe working fluid (15 g/mole) by a little more than ∼2% points, at higher cycle compression ratio than with He working fluid

  12. Osmotic and apparent molar properties of binary mixtures alcohol + 1-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid

    International Nuclear Information System (INIS)

    González, Emilio J.; Calvar, Noelia; Domínguez, Ángeles; Macedo, Eugénia A.

    2013-01-01

    Highlights: ► Osmotic and physical properties of binary mixtures {alcohol + [BMim][TfO]} were measured. ► From experimental data, apparent molar properties and osmotic coefficients were calculated. ► The apparent properties were fitted using a Redlich–Meyer type equation. ► The osmotic coefficients were correlated using the Extended Pitzer model. -- Abstract: In this work, physical properties (densities and speeds of sound) for the binary systems {1-propanol, or 2-propanol, or 1-butanol, or 2-butanol, or 1-pentanol + 1-butyl-3-methylimidazolium trifluoromethanesulfonate} were experimentally measured from T = (293.15 to 323.15) K and at atmospheric pressure. These data were used to calculate the apparent molar volume and apparent molar isentropic compression which were fitted to a Redlich–Meyer type equation. This fit was used to obtain the corresponding apparent molar properties at infinite dilution. On the other hand, the osmotic and activity coefficients and vapor pressures of these binary mixtures were also determined at T = 323.15 K using the vapor pressure osmometry technique. The Extended Pitzer model of Archer was employed to correlate the experimental osmotic coefficients. From the parameters obtained in the correlation, the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures were calculated

  13. Chronic toxicity of binary-metal mixtures of cadmium and zinc to Daphnia magna.

    Science.gov (United States)

    Pérez, Edgar; Hoang, Tham C

    2017-10-01

    The present study characterized the chronic effect of binary-metal mixtures of cadmium (Cd) and zinc (Zn) on Daphnia magna. The titration design was chosen to characterize the 21-d chronic effects of the binary-metal mixtures on survival, growth, reproduction, and metal accumulation in D. magna. Using this design, increasing concentrations of Zn (10, 20, 40, 80, 120, 160, and 200 μg/L) were titrated against a constant concentration of 1.5 μg/L Cd. The results demonstrated that Cd was highly toxic to D. magna. In a mixture with Cd and Zn, sublethal concentrations of 10 and 20 μg/L Zn were insufficient to protect D. magna from chronic Cd toxicity, whereas mixtures containing 40, 80, and 120 μg/L Zn provided strong protective effects to D. magna at all endpoints and resulted in less-than-additive effects. At higher Zn concentrations, such as 160 and 200 μg/L, Zn appeared to contribute to the toxicity. The less-than-additive effects observed in the Cd-Zn mixture can be explained by the decrease in body Cd concentration when the Zn concentration was increased in the exposure media. Embryos analyzed for morphological alterations in the Cd-Zn mixtures demonstrated severe developmental defects. The effect of Cd on undeveloped embryos while both Zn and Cd are present in the organisms raises a question of whether the competitive binding mechanism of Zn and Cd is still happening at the cellular level in the organisms. The results of the present study are useful for development of the biotic ligand model and environmental quality guidelines for metal mixtures. Environ Toxicol Chem 2017;36:2739-2749. © 2017 SETAC. © 2017 SETAC.

  14. Solubility Determination and Modeling and Dissolution Thermodynamic Properties of Raspberry Ketone in Binary Solvent Mixtures of Ethanol and Water

    Science.gov (United States)

    Shu, Min; Zhu, Liang; Wang, Yan-fei; Yang, Jing; Wang, Liyu; Yang, Libin; Zhao, Xiaoyu; Du, Wei

    2018-01-01

    The solubility and dissolution thermodynamic properties of raspberry ketone in a set of binary solvent mixtures (ethanol + water) with different compositions were experimentally determined by static gravimetrical method in the temperature range of 283.15-313.15 K at 0.10 MPa. The solubility of raspberry ketone in this series of ethanol/water binary solvent mixtures was found to increase with a rise in temperature and the rising mole fraction of ethanol in binary solvent mixtures. The van't Hoff, modified Apelblat and 3D Jouyban-Acree-van't Hoff equations were increasingly applied to correlate the solubility in ethanol/water binary solvent mixtures. The former two models could reach better fitting results with the solubility data, while the 3D model can be comprehensively used to estimate the solubility data in all the ratios of ethanol and water in binary solvent mixtures at random temperature. Furthermore, the changes of dissolution thermodynamic properties of raspberry ketone in experimental ethanol/water solvent mixtures were obtained by van't Hoff equation. For all the above experiments, these dissolution processes of raspberry ketone in experimental ethanol/water binary solvent mixtures were estimated to be endothermic and enthalpy-driven.

  15. Surface tension of nitric oxide and its binary mixtures with krypton, methane, and ethene

    Energy Technology Data Exchange (ETDEWEB)

    Calado, J.C.G.; Santos Mendonca, A.F.S. dos; Saramago, B.J.V.; Soares, V.A.M. [Instituto Superior Tecnico, Lisbon (Portugal). Centro de Quimica Estrutural

    1997-05-15

    The surface tension of three binary liquid mixtures of NO with Kr, CH{sub 4}, and C{sub 2}H{sub 4} has been determined as a function of composition in the temperature range 102.0 to 119.0 K. These measurements are a contribution to the study of binary liquid mixtures in which one component is unassociated while the molecules of the other can associate between themselves. Nitric oxide is the simplest molecule capable of forming dimers, but not larger aggregates. This results in the surface tension of liquid nitric oxide having a strong temperature dependence: when the temperature increases the degree of dimerization decreases, contributing to a larger decrease of the surface tension. The surface tension of NO mixtures shows strong deviations from ideality. The mixtures containing Kr and CH{sub 4} exhibit negative deviations, while for the NO + C{sub 2}H{sub 4} system the surface tension shows a complex dependence on the composition. This strong departure from ideality had already been found for the bulk properties of these three systems. The surface tension of the CH{sub 4} + Kr system, already well characterized in the literature, was also measured to test the equipment.

  16. Acoustic and Thermodynamic Properties of the Binary Liquid Mixture n-Octane + n-Dodecane

    Science.gov (United States)

    Khasanshin, T. S.; Golubeva, N. V.; Samuilov, V. S.; Shchemelev, A. P.

    2014-01-01

    The velocity of sound in the binary liquid mixture n-octane + n-dodecane has been investigated by the method of direct measurement of the pulse-transmission time in the interval of temperatures 298-433 K and pressures 0.1-100.1 MPa. The maximum measurement error amounts to 0.1%. The density, isobaric expansion coefficient, isobaric and isochoric heat capacities, and isothermal compressibility of a mixture of three compositions have been determined in the intervals of temperatures 298-393 K and pressures 0.1-100 MPa from the data on the velocity of sound. Also, the excess molar volume, the excess isothermal compressibility, and the deviation of the velocity of sound from its value for an ideal liquid have been determined. The coefficients of the Tate equation have been computed in the above temperature interval. A table of thermodynamic properties of the mixture has been presented.

  17. Study of the refractive index of gasoline+alcohol pseudo-binary mixtures

    Directory of Open Access Journals (Sweden)

    Nita Irina

    2017-02-01

    Full Text Available The properties of gasoline change as a result of blending with a bioalcohol, affecting the behavior of the pseudo-binary system. The aim of this paper is to present experimental data of the refractive index for pseudobinary mixtures of a reformate gasoline with ethanol, isopropanol and n-butanol over the entire composition range and for temperature ranging from 293.15 K to 313.15 K. The accuracy of different equations to predict the refractive index of the mixtures was tested. The best prediction accuracy (the lower AAD corresponded to Eykman and Lorentz-Lorenz mixing rules. A logarithmic equation proposed to correlate the refractive index with composition and temperature of gasoline+alcohol mixtures showed a good accuracy (the absolute average deviation AAD < 0.052%. The deviations in refractive index for investigated systems are negative over the entire composition range and at all investigated temperatures.

  18. Concurrent Co2+ and Sr2+ sorption from binary mixtures using aluminum industry waste: Kinetic study

    Science.gov (United States)

    Milenković, A.; Smičiklas, I.; Šljivić-Ivanović, M.; Vukelić, N.

    2015-12-01

    Multi-component sorption studies are essential to identify the applicability of red mud as a lowcost sorbent for the simultaneous removal of metal ions from wastewaters. Sorption kinetics of Co2+ and Sr2+ ions was investigated, at different total concentrations of mixtures and different molar ratios of two cations. Kinetics of metal sorption from binary systems was found to be well described by pseudo-second order rate model. Equilibrium sorbed amounts and equilibrium times for Co2+ sorption increased with the increase of its total concentration in the mixture, whereas pseudo-second order rate constants exhibited the opposite trend. Sr2+ sorption was strongly suppressed in the presence of Co2+ ions, and the removal efficiency decreased with increasing concentration and mole fraction of Co2+. Red mud can be used for simultaneous Co2+ and Sr2+ removal from mixtures of lower initial concentration, otherwise Co2+ sorption is dominant.

  19. Neural coding of binary mixtures in a structurally related odorant pair

    Science.gov (United States)

    Cruz, Georgina; Lowe, Graeme

    2013-01-01

    The encoding of odorant mixtures by olfactory sensory neurons depends on molecular interactions at peripheral receptors. However, the pharmacological basis of these interactions is not well defined. Both competitive and noncompetitive mechanisms of receptor binding and activation, or suppression, could contribute to coding. We studied this by analyzing responses of olfactory bulb glomeruli evoked by a pair of structurally related odorants, eugenol (EG) and methyl isoeugenol (MIEG). Fluorescence imaging in synaptopHluorin (spH) mice revealed that EG and MIEG evoked highly overlapped glomerular inputs, increasing the likelihood of mixture interactions. Glomerular responses to binary mixtures of EG and MIEG mostly showed hypoadditive interactions at intermediate and high odorant concentrations, with a few near threshold responses showing hyperadditivity. Dose-response profiles were well fitted by a model of two odorants competitively binding and activating a shared receptor linked to a non-linear transduction cascade. We saw no evidence of non-competitive mechanisms. PMID:23386975

  20. Dielectric properties of binary mixtures of methyl iso butyl ketone and amino silicone oil

    Science.gov (United States)

    Shah, K. N.; Rana, V. A.; Trivedi, C. M.; Vankar, H. P.

    2017-05-01

    Dielectric permittivity ɛ*(ω) = ɛ' - jɛ″ of the binary mixtures of the methyl iso butyl ketone and amino silicone oil in the frequency range 100 Hz to 2 MHz were measured using precision LCR meter at 305.15 K. Relative complex permittivity spectra in the frequency range 100 Hz to 2 MHz, of the mixture solutions of varying concentrations is reported. Determined values of the permittivity at optical frequency of all the samples are also reported. The dielectric parameters are used to gain information about the effect of concentration variation of components of the mixtures on the dielectric properties. It also provides the information about electrode polarization phenomena taking place under the low frequency A.C. electric field.

  1. Ideal gas solubilities and solubility selectivities in a binary mixture of room-temperature ionic liquids.

    Science.gov (United States)

    Finotello, Alexia; Bara, Jason E; Narayan, Suguna; Camper, Dean; Noble, Richard D

    2008-02-28

    This study focuses on the solubility behaviors of CO2, CH4, and N2 gases in binary mixtures of imidazolium-based room-temperature ionic liquids (RTILs) using 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][Tf2N]) and 1-ethyl-3-methylimidazolium tetrafluoroborate ([C2mim][BF4]) at 40 degrees C and low pressures (approximately 1 atm). The mixtures tested were 0, 25, 50, 75, 90, 95, and 100 mol % [C2mim][BF4] in [C2mim][Tf2N]. Results show that regular solution theory (RST) can be used to describe the gas solubility and selectivity behaviors in RTIL mixtures using an average mixture solubility parameter or an average measured mixture molar volume. Interestingly, the solubility selectivity, defined as the ratio of gas mole fractions in the RTIL mixture, of CO2 with N2 or CH4 in pure [C2mim][BF4] can be enhanced by adding 5 mol % [C2mim][Tf2N].

  2. New approach in modeling Cr(VI) sorption onto biomass from metal binary mixtures solutions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chang [College of Environmental Science and Engineering, Anhui Normal University, South Jiuhua Road, 189, 241002 Wuhu (China); Chemical Engineering Department, Escola Politècnica Superior, Universitat de Girona, Ma Aurèlia Capmany, 61, 17071 Girona (Spain); Fiol, Núria [Chemical Engineering Department, Escola Politècnica Superior, Universitat de Girona, Ma Aurèlia Capmany, 61, 17071 Girona (Spain); Villaescusa, Isabel, E-mail: Isabel.Villaescusa@udg.edu [Chemical Engineering Department, Escola Politècnica Superior, Universitat de Girona, Ma Aurèlia Capmany, 61, 17071 Girona (Spain); Poch, Jordi [Applied Mathematics Department, Escola Politècnica Superior, Universitat de Girona, Ma Aurèlia Capmany, 61, 17071 Girona (Spain)

    2016-01-15

    In the last decades Cr(VI) sorption equilibrium and kinetic studies have been carried out using several types of biomasses. However there are few researchers that consider all the simultaneous processes that take place during Cr(VI) sorption (i.e., sorption/reduction of Cr(VI) and simultaneous formation and binding of reduced Cr(III)) when formulating a model that describes the overall sorption process. On the other hand Cr(VI) scarcely exists alone in wastewaters, it is usually found in mixtures with divalent metals. Therefore, the simultaneous removal of Cr(VI) and divalent metals in binary mixtures and the interactive mechanism governing Cr(VI) elimination have gained more and more attention. In the present work, kinetics of Cr(VI) sorption onto exhausted coffee from Cr(VI)–Cu(II) binary mixtures has been studied in a stirred batch reactor. A model including Cr(VI) sorption and reduction, Cr(III) sorption and the effect of the presence of Cu(II) in these processes has been developed and validated. This study constitutes an important advance in modeling Cr(VI) sorption kinetics especially when chromium sorption is in part based on the sorbent capacity of reducing hexavalent chromium and a metal cation is present in the binary mixture. - Highlights: • A kinetic model including Cr(VI) reduction, Cr(VI) and Cr(III) sorption/desorption • Synergistic effect of Cu(II) on Cr(VI) elimination included in the model • Model validation by checking it against independent sets of data.

  3. Phase equilibrium data for potentially hazardous binary mixtures involving dichlorosilane, trichlorosilane and silicon-tetrachloride

    International Nuclear Information System (INIS)

    Nelson, Wayne Michael; Naidoo, Paramespri; Ramjugernath, Deresh

    2015-01-01

    Highlights: • Static-analytic equilibrium measurements for binary mixtures of chlorosilanes. • VLE data for (SiH 2 Cl 2 + SiHCl 3 ) at T = (343.04, 353.04 and 363.00) K. • VLE data for (SiH 2 Cl 2 + SiCl 4 ) at T = (343.28 and 353.07) K. • VLE data for (SiHCl 3 + SiCl 4 ) at T = (323.17, 333.11 and 343.03). • Data modeling with the Peng–Robinson EoS incorporating Wong–Sandler mixing rules. - Abstract: Isothermal (vapour + liquid) equilibrium data were obtained for potentially hazardous binary mixtures of (dichlorosilane + trichlorosilane), (dichlorosilane + tetrachlorosilane), and (trichlorosilane + tetrachlorosilane) using an apparatus based on the “static-analytic” method. The apparatus was specially developed and designed to ensure safe measurement of the flammable, toxic, and corrosive components. The (dichlorosilane + trichlorosilane) system was measured at T = (343.04, 353.04 and 363.00) K, and the (dichlorosilane + tetrachlorosilane) system at T = (343.28 and 353.07) K, and the (trichlorosilane + tetrachlorosilane) system at T = (323.17, 333.11 and 343.03) K. The resulting data were correlated with the Peng–Robinson equation of state coupled with the Wong Sandler mixing rule. The model provided accurate description of all isotherms of the binary systems using temperature-independent interaction parameters regressed for all isotherms.

  4. Thermodynamic properties of binary liquid mixtures of diethylenetriamine with alcohols at different temperatures

    International Nuclear Information System (INIS)

    Dubey, Gyan Prakash; Kumar, Krishan

    2011-01-01

    Highlights: → Thermodynamic study of diethylenetriamine + 2-methyl-1-propanol, +2-propanol or +1-butanol have been made. → Excess molar volumes and isentropic compressibility were determined. → Types of interactions were discussed based on derived properties. - Abstract: Densities, ρ, viscosities, η, and speeds of sound, u, were measured for the binary liquid mixtures containing diethylenetriamine with 2-methyl-1-propanol, 2-propanol and 1-butanol at 293.15, 298.15, 303.15, 308.15 and 313.15 K. From density and speed of sound data, excess molar volumes, V m E and deviations in isentropic compressibility, Δκ s , and speed of sound, Δu have been evaluated. Viscosity data were used to compute deviations in viscosity and excess Gibbs energy of activation of viscous flow ΔG* E at 298.15, 303.15 and 308.15 K. A Redlich-Kister type equation was applied to fit the excess molar volumes and deviations in isentropic compressibility, speed of sound and viscosity data. The viscosity data have been correlated with the equations of Grunberg-Nissan, Tamura-Kurata, Heric-Brewer and of Hind et al. All the binary systems of the present study have negative values of excess molar volumes and deviations in isentropic compressibility over whole composition range and at all temperatures which indicates strong interactions between the components of binary mixtures.

  5. Quantitative structure activity relationships (QSAR) for binary mixtures at non-equitoxic ratios based on toxic ratios-effects curves.

    Science.gov (United States)

    Tian, Dayong; Lin, Zhifen; Yin, Daqiang

    2013-01-01

    The present study proposed a QSAR model to predict joint effects at non-equitoxic ratios for binary mixtures containing reactive toxicants, cyanogenic compounds and aldehydes. Toxicity of single and binary mixtures was measured by quantifying the decrease in light emission from the Photobacterium phosphoreum for 15 min. The joint effects of binary mixtures (TU sum) can thus be obtained. The results showed that the relationships between toxic ratios of the individual chemicals and their joint effects can be described by normal distribution function. Based on normal distribution equations, the joint effects of binary mixtures at non-equitoxic ratios ( [Formula: see text]) can be predicted quantitatively using the joint effects at equitoxic ratios ( [Formula: see text]). Combined with a QSAR model of [Formula: see text]in our previous work, a novel QSAR model can be proposed to predict the joint effects of mixtures at non-equitoxic ratios ( [Formula: see text]). The proposed model has been validated using additional mixtures other than the one used for the development of the model. Predicted and observed results were similar (p>0.05). This study provides an approach to the prediction of joint effects for binary mixtures at non-equitoxic ratios.

  6. Novel two wavelength spectrophotometric methods for simultaneous determination of binary mixtures with severely overlapping spectra

    Science.gov (United States)

    Lotfy, Hayam M.; Saleh, Sarah S.; Hassan, Nagiba Y.; Salem, Hesham

    2015-02-01

    This work presents the application of different spectrophotometric techniques based on two wavelengths for the determination of severely overlapped spectral components in a binary mixture without prior separation. Four novel spectrophotometric methods were developed namely: induced dual wavelength method (IDW), dual wavelength resolution technique (DWRT), advanced amplitude modulation method (AAM) and induced amplitude modulation method (IAM). The results of the novel methods were compared to that of three well-established methods which were: dual wavelength method (DW), Vierordt's method (VD) and bivariate method (BV). The developed methods were applied for the analysis of the binary mixture of hydrocortisone acetate (HCA) and fusidic acid (FSA) formulated as topical cream accompanied by the determination of methyl paraben and propyl paraben present as preservatives. The specificity of the novel methods was investigated by analyzing laboratory prepared mixtures and the combined dosage form. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed. No difference was observed between the obtained results when compared to the reported HPLC method, which proved that the developed methods could be alternative to HPLC techniques in quality control laboratories.

  7. Gas suspension flows of a moderately dense binary mixture of solid particles in vertical tubes

    Energy Technology Data Exchange (ETDEWEB)

    Zamankhan, P.; Huotari, J. [VTT Energy, Jyvaeskylae (Finland). Combustion and Conversion Lab.

    1996-12-01

    The turbulent, steady, fully-developed flow of a moderately dense (solid volume faction >>0.001) binary mixture of spherical particles in a gaseous carrier is investigated for the case of flow in a vertical riser. The suspended particles are considered to be in turbulent motion, driven by random aerodynamic forces acting between the particle and the gaseous carrier as well as particle-particle interactive forces. A model is constructed based on the combination of the time-averaged after volume-averaged conservation equations of mass, momentum and mechanical energy of the gas phase in the continuum theory and the corresponding equations for the solid particles obtained using the recently developed Enskog theory for dense multi-component mixtures of slightly inelastic spherical particles. The model properly takes into account the contributions of particle-particle collisions, as well as the fluid-dynamic fluctuating forces on individual particles. To demonstrate the validity of this approach, the fully-developed steady-state mean velocity and concentration distributions of a moderately dense binary mixture of solid particles in a turbulent vertical flow calculated by the present model are compared with available experimental measurements. The results provide a qualitative description of the experimentally observed motion of coarse particles in a fast bed of fine solids. (author)

  8. Symmetrization of excess Gibbs free energy: A simple model for binary liquid mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Castellanos-Suarez, Aly J., E-mail: acastell@ivic.gob.v [Centro de Estudios Interdisciplinarios de la Fisica (CEIF), Instituto Venezolano de Investigaciones Cientificas (IVIC), Apartado 21827, Caracas 1020A (Venezuela, Bolivarian Republic of); Garcia-Sucre, Maximo, E-mail: mgs@ivic.gob.v [Centro de Estudios Interdisciplinarios de la Fisica (CEIF), Instituto Venezolano de Investigaciones Cientificas (IVIC), Apartado 21827, Caracas 1020A (Venezuela, Bolivarian Republic of)

    2011-03-15

    A symmetric expression for the excess Gibbs free energy of liquid binary mixtures is obtained using an appropriate definition for the effective contact fraction. We have identified a mechanism of local segregation as the main cause of the contact fraction variation with the concentration. Starting from this mechanism we develop a simple model for describing binary liquid mixtures. In this model two parameters appear: one adjustable, and the other parameter depending on the first one. Following this procedure we reproduce the experimental data of (liquid + vapor) equilibrium with a degree of accuracy comparable to well-known more elaborated models. The way in which we take into account the effective contacts between molecules allows identifying the compound which may be considered to induce one of the following processes: segregation, anti-segregation and dispersion of the components in the liquid mixture. Finally, the simplicity of the model allows one to obtain only one resulting interaction energy parameter, which makes easier the physical interpretation of the results.

  9. The precise measurement of the (vapour + liquid) equilibrium properties for (CO2 + isobutane) binary mixtures

    International Nuclear Information System (INIS)

    Nagata, Y.; Mizutani, K.; Miyamoto, H.

    2011-01-01

    Recently, it has been suggested that natural working fluids, such as CO 2 , hydrocarbons, and their mixtures, could provide a long-term alternative to fluorocarbon refrigerants. (Vapour + liquid) equilibrium (VLE) data for these fluids are essential for the development of equations of state, and for industrial process such as separation and refinement. However, there are large inconsistencies among the available literature data for (CO 2 + isobutane) binary mixtures, and therefore provision of reliable and new measurements with expanded uncertainties is required. In this study, we determined precise VLE data using a new re-circulating type apparatus, which was mainly designed by Akico Co., Japan. An equilibrium cell with an inner volume of about 380 cm 3 and two optical windows was used to observe the phase behaviour. The cell had re-circulating loops and expansion loops that were immersed in a thermostatted liquid bath and air bath, respectively. After establishment of a steady state in these loops, the compositions of the samples were measured by a gas chromatograph (GL Science, GC-3200). The VLE data were measured for CO 2 /propane and CO 2 /isobutane binary mixtures within the temperature range from 300 K to 330 K and at pressures up to 7 MPa. These data were compared with the available literature data and with values predicted by thermodynamic property models.

  10. An odor interaction model of binary odorant mixtures by a partial differential equation method.

    Science.gov (United States)

    Yan, Luchun; Liu, Jiemin; Wang, Guihua; Wu, Chuandong

    2014-07-09

    A novel odor interaction model was proposed for binary mixtures of benzene and substituted benzenes by a partial differential equation (PDE) method. Based on the measurement method (tangent-intercept method) of partial molar volume, original parameters of corresponding formulas were reasonably displaced by perceptual measures. By these substitutions, it was possible to relate a mixture's odor intensity to the individual odorant's relative odor activity value (OAV). Several binary mixtures of benzene and substituted benzenes were respectively tested to establish the PDE models. The obtained results showed that the PDE model provided an easily interpretable method relating individual components to their joint odor intensity. Besides, both predictive performance and feasibility of the PDE model were proved well through a series of odor intensity matching tests. If combining the PDE model with portable gas detectors or on-line monitoring systems, olfactory evaluation of odor intensity will be achieved by instruments instead of odor assessors. Many disadvantages (e.g., expense on a fixed number of odor assessors) also will be successfully avoided. Thus, the PDE model is predicted to be helpful to the monitoring and management of odor pollutions.

  11. Configuration-specific kinetic theory applied to an ideal binary gas mixture.

    Science.gov (United States)

    Wiseman, Floyd L

    2006-10-05

    This paper is the second in a two-part series dealing with the configuration-specific analyses for molecular collision events of hard, spherical molecules at thermal equilibrium. The first paper analyzed a single-component system, and the reader is referred to it for the fundamental concepts. In this paper, the expressions for the configuration-specific collision frequencies and the average line-of-centers collision angles and speeds are derived for an ideal binary gas mixture. The analyses show that the average line-of-centers quantities are all dependent upon the ratio of the masses of the two components, but not upon molecular size. Of course, the configuration-specific collision frequencies do depend on molecular size. The expression for the overall binary collision frequency is a simple sum of the configuration-specific collision frequencies and is identical to the conventional expression.

  12. Optimizing the surface density of polyethylene glycol chains by grafting from binary solvent mixtures

    Science.gov (United States)

    Arcot, Lokanathan; Ogaki, Ryosuke; Zhang, Shuai; Meyer, Rikke L.; Kingshott, Peter

    2015-06-01

    Polyethylene glycol (PEG) brushes are very effective at controlling non-specific deposition of biological material onto surfaces, which is of paramount importance to obtaining successful outcomes in biomaterials, tissue engineered scaffolds, biosensors, filtration membranes and drug delivery devices. We report on a simple 'grafting to' approach involving binary solvent mixtures that are chosen based on Hansen's solubility parameters to optimize the solubility of PEG thereby enabling control over the graft density. The PEG thiol-gold model system enabled a thorough characterization of PEG films formed, while studies on a PEG silane-silicon system examined the versatility to be applied to any substrate-head group system by choosing an appropriate solvent pair. The ability of PEG films to resist non-specific adsorption of proteins was quantitatively assessed by full serum exposure studies and the binary solvent strategy was found to produce PEG films with optimal graft density to efficiently resist protein adsorption.

  13. Flow regime and deposition pattern of evaporating binary mixture droplet suspended with particles.

    Science.gov (United States)

    Zhong, Xin; Duan, Fei

    2016-02-01

    The flow regimes and the deposition pattern have been investigated by changing the ethanol concentration in a water-based binary mixture droplet suspended with alumina nanoparticles. To visualize the flow patterns, Particle Image Velocimetry (PIV) has been applied in the binary liquid droplet containing the fluorescent microspheres. Three distinct flow regimes have been revealed in the evaporation. In Regime I, the vortices and chaotic flows are found to carry the particles to the liquid-vapor interface and to promote the formation of particle aggregation. The aggregates move inwards in Regime II as induced by the Marangoni flow along the droplet free surface. Regime III is dominated by the drying of the left water and the capillary flow driving particles radially outward is observed. The relative weightings of Regimes I and II, which are enhanced with an increasing load of ethanol, determine the motion of the nanoparticles and the formation of the final drying pattern.

  14. Binary mixtures of neonicotinoids show different transcriptional changes than single neonicotinoids in honeybees (Apis mellifera).

    Science.gov (United States)

    Christen, Verena; Bachofer, Sara; Fent, Karl

    2017-01-01

    Among the many factors responsible for the decline of bee populations are plant protection products such as neonicotinoids. In general, bees are exposed to not only one but mixtures of such chemicals. At environmental realistic concentrations neonicotinoids may display negative effects on the immune system, foraging activity, learning and memory formation of bees. Neonicotinoids induce alterations of gene transcripts such as nicotinic acetylcholine receptor (nAChR) subunits, vitellogenin, genes of the immune system and genes linked to memory formation. While previous studies focused on individual compounds, the effect of neonicotinoid mixtures in bees is poorly known. Here we investigated the effects of neonicotinoids acetamiprid, clothianidin, imidacloprid and thiamethoxam as single compounds, and binary mixtures thereof in honeybees. We determined transcriptional changes of nAChR subunits and vitellogenin in the brain of experimentally exposed honeybees after exposure up to 72 h. Exposure concentrations were selected on the basis of lowest effect concentrations of the single compounds. Transcriptional induction of nAChRs and vitellogenin was strongest for thiamethoxam, and weakest for acetamiprid. To a large extent, binary mixtures did not show additive transcriptional inductions but they were less than additive. Our data suggest that the joint transcriptional activity of neonicotinoids cannot be explained by concentration addition. The in vivo effects are not only governed by agonistic interaction with nAChRs alone, but are more complex as a result of interactions with other pathways as well. Further studies are needed to investigate the physiological joint effects of mixtures of neonicotinoids and other plant protection products on bees to better understand their joint effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. How Is the Freezing Point of a Binary Mixture of Liquids Related to the Composition? A Guided Inquiry Experiment

    Science.gov (United States)

    Hunnicutt, Sally S.; Grushow, Alexander; Whitnell, Rob

    2017-01-01

    The principles of process-oriented guided inquiry learning (POGIL) are applied to a binary solid-liquid mixtures experiment. Over the course of two learning cycles, students predict, measure, and model the phase diagram of a mixture of fatty acids. The enthalpy of fusion of each fatty acid is determined from the results. This guided inquiry…

  16. Synergistic toxicity and physiological impact of imidacloprid alone and binary mixtures with seven representative pesticides on honey bee (Apis mellifera)

    Science.gov (United States)

    Imidacloprid is the most widely used insecticide in the world. In this study, we used spraying methods to simulate field exposures of bees to formulated imidacloprid (Advise® 2FL) alone and binary mixtures with seven pesticides from different classes. Synergistic toxicity was detected from mixtures ...

  17. Quantitative Characterization of the Toxicities of Cd-Ni and Cd-Cr Binary Mixtures Using Combination Index Method

    Directory of Open Access Journals (Sweden)

    Lingyun Mo

    2016-01-01

    Full Text Available Direct equipartition ray design was used to construct Cd-Ni and Cd-Cr binary mixtures. Microplate toxicity analysis was used to evaluate the toxicity of individual substance and the Cd-Ni and Cd-Cr mixtures on Chlorella pyrenoidosa and Selenastrum capricornutum. The interacting toxicity of the mixture was analyzed with concentration addition (CA model. In addition, combination index method (CI was proposed and used to quantitatively characterize the toxicity of the binary mixtures of Cd-Ni and Cd-Cr observed in experiment and find the degree of deviation from the predicted outcome of the CA model, that is, the intensity of interacting toxicity. Results indicate that most of the 20 binary mixtures exhibit enhancing and synergistic effect, and only Cd-Cr-R4 and Cd-Cr-R5 mixtures have relatively high antagonistic effects against C. pyrenoidosa. Based on confidence interval, CI can compare the intensities of interaction of the mixtures under varying levels of effect. The characterization methods are applicable for analyzing binary mixture with complex interaction.

  18. The performance of a residential heat pump operating with a nonazeotropic binary refrigerant mixture

    Science.gov (United States)

    Didion, D.; Mulroy, W.

    Results of laboratory measurement of the performance change of a substantially unmodified residential heat pump designed for 222 when charged with a non azeotropic, binary mixture of R1381 and R152a is presented. Results are presented for various sizes of fixed expansion devices. The effect of gliding temperature in the saturation zone was found to be small. The effect of compositions shift by flash distillation in the accumulator was found to measurably improve low temperature heating performance. It was further observed that some system modification (such as the addition of a receiver) could have further enhanced this low temperature heating performance improvement.

  19. (Vapor + liquid) equilibria of binary mixtures containing light alcohols and ionic liquids

    International Nuclear Information System (INIS)

    Revelli, Anne-Laure; Mutelet, Fabrice; Jaubert, Jean-Noel

    2010-01-01

    This work presents (vapor + liquid) equilibrium (VLE) of binary mixtures containing methanol or ethanol and three imidazolium based ionic liquids: 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium acetate, and 1-butyl-3-methylimidazolium hydrogen sulfate. VLE measurements were carried out over the whole range of composition between (283.15 and 298.15) K using a static apparatus. Activity coefficients γ i of these solvents in the ionic liquids have been determined from the VLE data and correlated using the NRTL model. The results show that the NRTL model can be applied successfully with systems containing ionic liquids.

  20. Experimental and Predicted Viscosities of Binary Mixtures Containing Chlorinated and Oxygenated Compounds

    Science.gov (United States)

    Montaño, D.; Artigas, H.; Royo, F. M.; Lafuente, Carlos

    2013-01-01

    This study presents the viscosities, both kinematic and dynamic, of binary mixtures of 1-chlorobutane, 2-chlorobutane, or 1-chloro-2-methylpropane with butyl ethyl ether or methyl tert-butyl ether from T = 283.15 K to T = 313.15 K at atmospheric pressure as a function of composition. Kinematics viscosities were measured using an Ubbelohde viscometer. The dynamic viscosities were obtained from experimental kinematic viscosities and previously reported density data. The viscosity results have been employed to check the reliability of the Wu-UNIFAC method.

  1. Experimental determination and prediction of liquid-solid equilibria for binary (methyl palimitate + naphthalene mixture

    Directory of Open Access Journals (Sweden)

    Benziane M.

    2013-07-01

    Full Text Available Solid-liquid equilibria for binary mixtures of {Methyl palmitate (1 + Naphthalene (2} were measured using differential scanning calorimeter (DSC. Simple eutectic behaviours for this system are observed. The experimental results were correlated by means of the NRTL, Wilson, UNIQUAC and ideal models. The root-mean-square deviations of the solubility temperatures for all measured data vary from 0.5477 K (for UNIQUAC model to 3.34K; the deviation depend on the model used. The best solubility correlation was obtained with UNIQUAC model and this observation confirms previous results.

  2. Phase equilibria of binary mixtures by molecular simulation and cubic equations of state

    Directory of Open Access Journals (Sweden)

    Cabral V.F.

    2001-01-01

    Full Text Available Molecular simulation data were used to study the performance of equations of state (EoS and combining rules usually employed in thermodynamic property calculations. The Monte Carlo method and the Gibbs ensemble technique were used for determining composition and densities of vapor and liquid phases in equilibrium for binary mixtures of Lennard-Jones fluids. Simulation results are compared to data in the literature and to those calculated by the t-PR-LJ EoS. The use of adequate combining rules has been shown to be very important for the satisfactory representation of molecular simulation data.

  3. Effect of a marginal inclination on pattern formation in a binary liquid mixture under thermal stress.

    Science.gov (United States)

    Croccolo, Fabrizio; Scheffold, Frank; Vailati, Alberto

    2013-07-05

    Convective motions in a fluid layer are affected by its orientation with respect to the gravitational field. We investigate the long-term stability of a thermally stressed layer of a binary liquid mixture and show that pattern formation is strongly affected by marginal inclinations as small as a few milliradians. At small Rayleigh numbers, the mass transfer is dominated by the induced large scale shear flow, while at larger Rayleigh numbers, it is dominated by solutal convection. At the transition, the balance between the solutal and shear flows gives rise to drifting columnar flows moving in opposite directions along parallel lanes in a superhighway configuration.

  4. Polarographic behaviour and determination of selenite and tellurite in simple solutions or in a binary mixture

    International Nuclear Information System (INIS)

    Hassan, A.

    1991-01-01

    The polarographic behaviour of simple solutions of selenite and tellurite in 1 M ammonium salts of formate, acetate, tartrate, oxalate, and benzoate solutions in absence and in presence of Triton X-100 as a maximum suppressor and a temperature of 25 O C has been investigated. Schemes for the mechanism of reductions occuring at the DME have been deduced. A method for analytical determination of selenite and tellurite in simple solutions as well as in a binary mixture in the presence of 4-14 . 10 -3 % Triton X-100 is reported. (author)

  5. Electro-optic and dielectric properties of new binary ferroelectric and antiferroelectric liquid crystalline mixtures

    Czech Academy of Sciences Publication Activity Database

    Fitas, J.; Marzec, M.; Kurp, K.; Żurowska, M.; Tykarska, M.; Bubnov, Alexej

    2017-01-01

    Roč. 44, č. 9 (2017), s. 1468-1476 ISSN 0267-8292 R&D Projects: GA MŠk(CZ) LD14007; GA ČR GA15-02843S Grant - others:EU - ICT(XE) COST Action IC1208 Institutional support: RVO:68378271 Keywords : liquid crystals * ferroelectric and antiferroelectric phase * binary mixture * dielectric spectroscopy * switching time * tilt angle Subject RIV: JJ - Other Materials OBOR OECD: Nano-materials (production and properties) Impact factor: 2.661, year: 2016

  6. Enthalpies of solution of ampicillin, amoxycillin and their binary mixtures at 310.15 K.

    Science.gov (United States)

    Jain, D V; Kashid, N; Kapoor, S; Chadha, R

    2000-05-15

    Enthalpies of solutions of ampicillin, amoxycillin and their binary mixtures have been determined at pH 2, 5, and 7 using C-80 calorimeter. The systems showed endothermic behaviour; molar enthalpies of solutions of ampicillin were determined to be 13.32, 15.89 and 23.21 kJ mol(-1) and amoxycillin were 16.32, 18.45 and 26. 25 kJ mol(-1) at pH 2, 5, and 7, respectively. The excess molar enthalpies of solution have also been calculated to find any interaction between these two drugs.

  7. Very low velocity ion slowing down in binary ionic mixtures: Charge- and mass-asymmetry effects

    Directory of Open Access Journals (Sweden)

    Patrice Fromy

    2010-10-01

    Full Text Available A binary ionic mixture (BIM in dense and hot plasmas of specific concern for inertial confinement fusion and white dwarf crust is considered as a target for incoming light ions with a velocity smaller than the thermal electron one. The given target stopping power, mostly BIM monitored, is specifically studied in terms of charge and mass asymmetry in its ionic component. The classical plasma target is worked out within a dielectric framework, and scanned with respect to density, temperature, and BIM composition.

  8. Solid-state characterization of paracetamol metastable polymorphs formed in binary mixtures with hydroxypropylmethylcellulose

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Alessandra; Savioli, Alessandra; Bini, Marcella; Capsoni, Doretta; Massarotti, Vincenzo; Bettini, Ruggero; Gazzaniga, Andrea; Sangalli, Maria Edvige; Giordano, Ferdinando

    2003-11-28

    Two metastable polymorphs of paracetamol (forms II and III) were prepared by appropriate thermal methods from binary mixtures containing 10% (w/w) of hydroxypropylmethylcellulose. By controlling the reheating step, it was possible to address the recrystallization of the drug either into form II or III. Moreover, it was observed that form III transforms either into form II or I depending on the preparation method. The physical characterization of the polymorphs was performed by means of micro-Fourier transform infrared spectroscopy (MFTIR) and powder X-ray diffractometry (PXRD), both temperature controlled.

  9. Phase equilibria of binary mixtures by molecular simulation and cubic equations of state

    OpenAIRE

    Cabral,V.F.; Pinto,R.R.C.; Tavares,F.W.; Castier,M.

    2001-01-01

    Molecular simulation data were used to study the performance of equations of state (EoS) and combining rules usually employed in thermodynamic property calculations. The Monte Carlo method and the Gibbs ensemble technique were used for determining composition and densities of vapor and liquid phases in equilibrium for binary mixtures of Lennard-Jones fluids. Simulation results are compared to data in the literature and to those calculated by the t-PR-LJ EoS. The use of adequate combining rule...

  10. Acute effects of binary mixtures of Type II pyrethroids and organophosphate insecticides on Oreochromis niloticus.

    Science.gov (United States)

    Fai, Patricia Bi Asanga; Tsobgny Kinfack, Joel Stephane; Tala Towa, Yannick Jordan

    2017-09-01

    Pyrethroid and organophosphate insecticides have been used for more than 20 years worldwide to control a variety of insect pest in different settings. These pesticides have been detected in a variety of environmental samples, including surface waters and sediments and therefore there is significant concern about their potential toxic effects on non-target organisms. Mixtures of compounds from these groups of pesticides have been found to frequently show enhanced toxicity but it has been a challenge to predict whether or not enhanced toxicity will occur for a given combination of compounds. This study therefore studied the effects of binary pyrethroid-organophosphate mixtures using cypermethrin, deltamethrin and dimethoate in an acute toxicity test system with Oreochromis niloticus. The 96 h LC50s for individual insecticides were 9.13 µg/l, 9.42 µg/l and 45.52 mg/l for cypermethrin, deltamethrin and dimethoate respectively. These showed that the pyrethroid insecticides were highly toxic to Oreochromis niloticus and were far more toxic than dimethoate. All mixtures were also more toxic than single insecticides throughout the concentration-response curve with mixtures resulting in mortality at concentrations which the individual pesticides in the mixture were below their respective NOECs. In addition, observed mixture toxicities deviated from the predicted mixture effects based either on the Concentration Addition (CA) or Independent Action (IA) models independent of mixture ratio. However, the extent of observed mixture mortality deviation was dependent on the effect level. Significant deviations (MDR > 2.0) were observed at lower concentrations indicating synergistic effects at lower and possibly environmentally relevant concentrations. This is not unexpected since organophosphate insecticides are known to inhibit acetylcholinesterase as well as inactivate esterase, resulting in reduced detoxification of pyrethroid insecticides and consequently greater

  11. Vibro-electrostatic separation of binary ABS/PS granular mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Saeki, Masato [Department of Mechanical and Control Engineering, Niigata Institute of Technology, Fujihashi, Kashiwazaki, Niigata (Japan)], E-mail: saeki@mce.niit.ac.jp

    2008-12-01

    This paper presents the results of experimental studies of the performance of avibro-electrostatic plastic separator, which essentially consists of two plate electrodes undergoing translational harmonic vibrations along the horizontal plane. The principle behind the separation technique for such a separator is based on the difference between Coulomb forces acting on plastic particles after triboelectric charging. The separator has the advantages of a low-voltage field and a small structure over free-fall triboelectric separators. Separation tests were performed on binary mixtures. The effects of the feed composition of the mixtures and operating parameters, such as electric field strength, applied voltage polarity and triboelectric charging time, on separation efficiency were examined. This study was conducted to understand the effects of various parameters on separation efficiency, in order to obtain the optimum operating conditions for separators.

  12. Physicochemical analysis and nonisothermal kinetic study of sertraline-lactose binary mixtures.

    Science.gov (United States)

    Ghaderi, Faranak; Nemati, Mahboob; Siahi-Shadbad, Mohammad Reza; Valizadeh, Hadi; Monajjemzadeh, Farnaz

    2017-07-01

    In the present study the physicochemical stability of sertraline with lactose was evaluated in drug-excipient binary mixtures. Different physicochemical methods such as differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy, and mass spectrometry were applied to confirm the incompatibility. The final aim of this study was to evaluate the kinetic parameters using a fast and sensitive DSC method. Solid-state kinetic parameters were derived from nonisothermally stressed physical mixtures using different thermal models such as Friedman, Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose. Overall, the instability of sertraline with lactose was successfully evaluated. Further confirmation was made by tracking the Maillard reaction product of sertraline and lactose by mass spectrometry. DSC scans provided important information about the stability of sertraline in solid-state condition and also revealed the related thermokinetic parameters in order to understand the nature of the chemical instability. Copyright © 2016. Published by Elsevier B.V.

  13. Undulation amplitude of a fluid membrane surrounded by near-critical binary fluid mixtures.

    Science.gov (United States)

    Fujitani, Youhei

    2015-04-01

    We consider the thermal undulation, or shape fluctuation, of an almost planar fluid membrane surrounded by the same near-critical binary fluid mixtures on both sides. A weak preferential attraction is assumed between the membrane and one component of the mixture. We use the Gaussian free-energy functional to study the equilibrium average of the undulation amplitude within the linear approximation with respect to the amplitude. According to our result given by a simple analytic formula, the ambient near-criticality tends to suppress the undulation of a membrane, and this suppression effect can overwhelm that of the bending rigidity for small wave numbers. Thus, the ambient near-criticality is suggested to prevent a large membrane from becoming floppy even if the lateral tension vanishes at the equilibrium.

  14. Dissipative particle dynamics study of phase separation in binary fluid mixtures in periodic and confined domains.

    Science.gov (United States)

    Gidituri, Harinadha; Anand, D Vijay; Vedantam, Srikanth; Panchagnula, Mahesh V

    2017-08-21

    We investigate the phase separation behavior of binary mixtures in two-dimensional periodic and confined domains using dissipative particle dynamics. Two canonical problems of fluid mechanics are considered for the confined domains: square cavity with no-slip walls and lid-driven cavity with one driven wall. The dynamics is studied for both weakly and strongly separating mixtures and different area fractions. The phase separation process is analyzed using the structure factor and the total interface length. The dynamics of phase separation in the square cavity and lid-driven cavity are observed to be significantly slower when compared to the dynamics in the periodic domain. The presence of the no-slip walls and the inertial effects significantly influences the separation dynamics. Finally, we show that the growth exponent for the strongly separating case is invariant to changes in the inter-species repulsion parameter.

  15. NON-EQUILIBRIUM MOLECULAR DYNAMICS USED TO OBTAIN SORET COEFFICIENTS OF BINARY HYDROCARBON MIXTURES

    Directory of Open Access Journals (Sweden)

    F. A. Furtado

    2015-09-01

    Full Text Available AbstractThe Boundary Driven Non-Equilibrium Molecular Dynamics (BD-NEMD method is employed to evaluate Soret coefficients of binary mixtures. Using a n-decane/n-pentane mixture at 298 K, we study several parameters and conditions of the simulation procedure such as system size, time step size, frequency of perturbation, and the undesired warming up of the system during the simulation. The Soret coefficients obtained here deviated around 20% when comparing with experimental data and with simulated results from the literature. We showed that fluctuations in composition gradients and the consequent deviations of the Soret coefficient may be due to characteristic fluctuations of the composition gradient. Best results were obtained with the smallest time steps and without using a thermostat, which shows that there is room for improvement and/or development of new BD-NEMD algorithms.

  16. Transport properties of binary liquid mixtures - candidate solvents for optimized flue gas cleaning processes

    Directory of Open Access Journals (Sweden)

    Stanimirović Andrej M.

    2016-01-01

    Full Text Available Thermal conductivities and viscosities of three pure chemicals, monoethanol amine (MEA, tetraethylene glycol dimethyl ether (TEGDME and polyethylene glycol 200 (PEG 200 and two binary mixtures (MEA + + TEGDME and MEA + PEG 200 were measured at six temperatures: 298.15, 303.15, 308.15, 313.15, 318.15 and 323.15 K and atmospheric pressure. Measurement of thermal conductivities was based on a transient hot wire measurement setup, while viscosities were measured with a digital Stabinger SVM 3000/G2 viscometer. From these data, deviations in thermal conductivity and viscosity were calculated and fitted to the Redlich-Kister equation. Thermal conductivities of mixtures were correlated using Filippov, Jamieson, Baroncini and Rowley models, while viscosity data were correlated with the Eyring-UNIQUAC, Eyring-NRTL and McAlistermodels. [Projekat Ministarstva nauke Republike Srbije, br. 172063

  17. Liquid-liquid interfacial properties of a symmetrical Lennard-Jones binary mixture

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Ruiz, F. J.; Blas, F. J., E-mail: felipe@uhu.es [Laboratorio de Simulación Molecular y Química Computacional, CIQSO-Centro de Investigación en Química Sostenible and Departamento de Física Aplicada, Universidad de Huelva, 21007 Huelva (Spain); Moreno-Ventas Bravo, A. I. [Laboratorio de Simulación Molecular y Química Computacional, CIQSO-Centro de Investigación en Química Sostenible and Departamento de Geología, Universidad de Huelva, 21007 Huelva (Spain)

    2015-09-14

    We determine the interfacial properties of a symmetrical binary mixture of equal-sized spherical Lennard-Jones molecules, σ{sub 11} = σ{sub 22}, with the same dispersive energy between like species, ϵ{sub 11} = ϵ{sub 22}, but different dispersive energies between unlike species low enough to induce phase separation. We use the extensions of the improved version of the inhomogeneous long-range corrections of Janecek [J. Phys. Chem. B 110, 6264 (2006)], presented recently by MacDowell and Blas [J. Chem. Phys. 131, 074705 (2009)] and Martínez-Ruiz et al. [J. Chem. Phys. 141, 184701 (2014)], to deal with the interaction energy and microscopic components of the pressure tensor. We perform Monte Carlo simulations in the canonical ensemble to obtain the interfacial properties of the symmetrical mixture with different cut-off distances r{sub c} and in combination with the inhomogeneous long-range corrections. The pressure tensor is obtained using the mechanical (virial) and thermodynamic route. The liquid-liquid interfacial tension is also evaluated using three different procedures, the Irving-Kirkwood method, the difference between the macroscopic components of the pressure tensor, and the test-area methodology. This allows to check the validity of the recent extensions presented to deal with the contributions due to long-range corrections for intermolecular energy and pressure tensor in the case of binary mixtures that exhibit liquid-liquid immiscibility. In addition to the pressure tensor and the surface tension, we also obtain density profiles and coexistence densities and compositions as functions of pressure, at a given temperature. According to our results, the main effect of increasing the cut-off distance r{sub c} is to sharpen the liquid-liquid interface and to increase the width of the biphasic coexistence region. Particularly interesting is the presence of a relative minimum in the total density profiles of the symmetrical mixture. This minimum is related

  18. Cadmium-induced olfactory dysfunction in rainbow trout: Effects of binary and quaternary metal mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Dew, William A. [Biological Sciences, University of Lethbridge, Lethbridge, Alberta T1 K 3M4 (Canada); Department of Biology, Trent University, Peterborough, Ontario K9 J 7B8 (Canada); Veldhoen, Nik; Carew, Amanda C.; Helbing, Caren C. [Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8 P 5C2 Canada (Canada); Pyle, Greg G., E-mail: gregory.pyle@uleth.ca [Biological Sciences, University of Lethbridge, Lethbridge, Alberta T1 K 3M4 (Canada)

    2016-03-15

    Highlights: • Cadmium impairs the olfactory response of rainbow trout. • Nickel and zinc, but not copper, protect against Cd-induced olfactory dysfunction. • Calcium, sodium, and magnesium also protect against the effect of cadmium. • Protection from cadmium is most likely not due to metallothionein expression. - Abstract: A functioning olfactory response is essential for fish to be able to undertake essential behaviors. The majority of work investigating the effects of metals on the olfactory response of fish has focused on single-metal exposures. In this study we exposed rainbow trout to cadmium, copper, nickel, zinc, or a mixture of these four metals at or below the current Canadian Council of Ministers of the Environment guidelines for the protection of aquatic life. Measurement of olfactory acuity using an electro-olfactogram demonstrated that cadmium causes significant impairment of the entire olfactory system, while the other three metals or the mixture of all four metals did not. Binary mixtures with cadmium and each of the other metals demonstrated that nickel and zinc, but not copper, protect against cadmium-induced olfactory dysfunction. Testing was done to determine if the protection from cadmium-induced olfactory dysfunction could be explained by binding competition between cadmium and the other metals at the cell surface, or if the protection could be explained by an up-regulation of an intracellular detoxification pathway, namely metallothionein. This study is the first to measure the effects of binary and quaternary metal mixtures on the olfactory response of fish, something that will aid in future assessments of the effects of metals on the environment.

  19. Spectroscopic and DFT study of solvent effects on the electronic absorption spectra of sulfamethoxazole in neat and binary solvent mixtures.

    Science.gov (United States)

    Almandoz, M C; Sancho, M I; Blanco, S E

    2014-01-24

    The solvatochromic behavior of sulfamethoxazole (SMX) was investigated using UV-vis spectroscopy and DFT methods in neat and binary solvent mixtures. The spectral shifts of this solute were correlated with the Kamlet and Taft parameters (α, β and π(*)). Multiple lineal regression analysis indicates that both specific hydrogen-bond interaction and non specific dipolar interaction play an important role in the position of the absorption maxima in neat solvents. The simulated absorption spectra using TD-DFT methods were in good agreement with the experimental ones. Binary mixtures consist of cyclohexane (Cy)-ethanol (EtOH), acetonitrile (ACN)-dimethylsulfoxide (DMSO), ACN-dimethylformamide (DMF), and aqueous mixtures containing as co-solvents DMSO, ACN, EtOH and MeOH. Index of preferential solvation was calculated as a function of solvent composition and non-ideal characteristics are observed in all binary mixtures. In ACN-DMSO and ACN-DMF mixtures, the results show that the solvents with higher polarity and hydrogen bond donor ability interact preferentially with the solute. In binary mixtures containing water, the SMX molecules are solvated by the organic co-solvent (DMSO or EtOH) over the whole composition range. Synergistic effect is observed in the case of ACN-H2O and MeOH-H2O, indicating that at certain concentrations solvents interact to form association complexes, which should be more polar than the individual solvents of the mixture. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Fluid phase interface properties of acetone, oxygen, nitrogen and their binary mixtures by molecular simulation.

    Science.gov (United States)

    Eckelsbach, Stefan; Vrabec, Jadran

    2015-10-28

    Vapor-liquid equilibria (VLE) of the pure substances acetone, oxygen and nitrogen as well as their binary mixtures are studied by molecular dynamics (MD) simulation with a direct approach. Thereby, particular attention is paid to the interface behavior on the molecular level, yielding total and partial density profiles as well as surface tension data. The classical approach by van der Waals is used to analyze the total density profiles. It is found that an extended function is needed to describe those profiles for the mixtures containing acetone, due to the strong adsorption of the volatile component at the vapor side of the interface. Based on these representations the interface thickness is studied. The surface tension results are compared to experimental data, correlations thereof and results from other molecular approaches. Due to the scarcity of experiments, the parachor method is employed to obtain predictive surface tension data for the mixtures. Following the same approach, the present surface tension results are correlated for the mixtures containing acetone.

  1. Relationships between surface coverage ratio and powder mechanics of binary adhesive mixtures for dry powder inhalers.

    Science.gov (United States)

    Rudén, Jonas; Frenning, Göran; Bramer, Tobias; Thalberg, Kyrre; Alderborn, Göran

    2018-04-25

    The aim of this paper was to study relationships between the content of fine particles and the powder mechanics of binary adhesive mixtures and link these relationships to the blend state. Mixtures with increasing amounts of fine particles (increasing surface coverage ratios (SCR)) were prepared using Lactopress SD as carrier and micro particles of lactose as fines (2.7 µm). Indicators of unsettled bulk density, compressibility and flowability were derived and the blend state was visually examined by imaging. The powder properties studied showed relationships to the SCR characterised by stages. At low SCR, the fine particles predominantly gathered in cavities of the carriers, giving increased bulk density and unchanged or improved flow. Thereafter, increased SCR gave a deposition of particles at the enveloped carrier surface with a gradually more irregular adhesion layer leading to a reduced bulk density and a step-wise reduced flowability. The mechanics of the mixtures at a certain stage were dependent on the structure and the dynamics of the adhesion layer and transitions between the stages were controlled by the evolution of the adhesion layer. It is advisable to use techniques based on different types of flow in order to comprehensively study the mechanics of adhesive mixtures. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Dual-Mode Measurement and Theoretical Analysis of Evaporation Kinetics of Binary Mixtures

    Science.gov (United States)

    Song, Hanyu; He, Chi-Ruei; Basdeo, Carl; Li, Ji-Qin; Ye, Dezhuang; Kalonia, Devendra; Li, Si-Yu; Fan, Tai-Hsi

    Theoretical and experimental investigations are presented for the precision measurement of evaporation kinetics of binary mixtures using a quartz crystal resonator. A thin layer of light alcohol mixture including a volatile (methanol) and a much less volatile (1-butanol) components is deployed on top of the resonator. The normal or acoustic mode is to detect the moving liquid-vapor interface due to evaporation with a great spatial precision on the order of microns, and simultaneously the shear mode is used for in-situ detection of point viscosity or concentration of the mixture near the resonator. A one-dimensional theoretical model is developed to describe the underlying mass transfer and interfacial transport phenomena. Along with the modeling results, the transient evaporation kinetics, moving interface, and the stratification of viscosity of the liquid mixture during evaporation are simultaneously measured by the impedance response of the shear and longitudinal waves emitted from the resonator. The system can be used to characterize complicated evaporation kinetics involving multi-component fuels. American Chemical Society Petroleum Research Fund, NSF CMMI-0952646.

  3. Dielectric Behaviour of Binary Mixture of 2-Chloroaniline with 2-Methoxyethanol and 2-Ethoxyethanol

    Directory of Open Access Journals (Sweden)

    Bhupesh G. Nemmaniwar

    2013-05-01

    Full Text Available Densities, viscosities, refractive indices, dielectric constant (ε' and dielectric loss (ε'' of 2-chloroaniline (2CA + 2-methoxyethanol (2ME and 2-chloroaniline (2CA + 2-ethoxyethanol (2EE for different mole fractions of 2-chloroaniline in binary mixture have been measured at single microwave frequency 10.985 GHz at 300C by Surber method using microwave X-band. The values of dielectric parameters (ε' and ε''   have been used to evaluate the molar polarization (P12 loss tangent (tanδ, viscosity (η, activation energy (Ea, excess permittivity (Δε', excess dielectric loss (Δε'', excess viscosities (Δη, excess polarization (ΔP12 and excess activation energy (ΔEa  have also been estimated. These parameters have been used to explain the formation of complexes in the system. It is found that dielectric constant (ε', dielectric loss (ε'', loss tangent (tanδ, molar polarization (P12 varies non-linearly but activation energy (Ea , viscosity (η ,density (ρ, and refractive index (n varies linearly with increasing mole fraction in binary mixture of 2-chloroaniline (2-CA + 2-methoxyethanol (2-ME and 2-chloroaniline (2-CA + 2-ethoxyethanol (2-EE. Hence, solute-solvent molecular associations have been reported. 

  4. Phase-coexisting patterns, horizontal segregation, and controlled convection in vertically vibrated binary granular mixtures

    Science.gov (United States)

    Ansari, Istafaul Haque; Rivas, Nicolas; Alam, Meheboob

    2018-01-01

    We report patterns consisting of coexistence of synchronous and asynchronous states [for example, a granular gas co-existing with (i) bouncing bed, (ii) undulatory subharmonic waves, and (iii) Leidenfrost-like states] in experiments on vertically vibrated binary granular mixtures in a Hele-Shaw cell. Most experiments have been carried out with equimolar binary mixtures of glass and steel balls of same diameter by varying the total layer height (F ) for a range of shaking acceleration (Γ ). All patterns as well as the related phase diagram in the (Γ ,F ) plane have been reproduced via molecular dynamics simulations of the same system. The segregation of heavier and lighter particles along the horizontal direction is shown to be the progenitor of such phase-coexisting patterns as confirmed in both experiment and simulation. At strong shaking we uncover a partial convection state in which a pair of convection rolls is found to coexist with a Leidenfrost-like state. The crucial role of the relative number density of two species on controlling the buoyancy-driven granular convection is demonstrated. The onset of horizontal segregation can be explained in terms of an anisotropic diffusion tensor.

  5. Quantum cluster equilibrium model of N-methylformamide–water binary mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Domaros, Michael von; Kirchner, Barbara, E-mail: kirchner@thch.uni-bonn.de [Mulliken Center for Theoretical Chemistry, Universität Bonn, Beringstr. 4, D-53115 Bonn (Germany); Jähnigen, Sascha [Martin-Luther-Universität Halle-Wittenberg, von-Danckelmann-Platz 4, D-06120 Halle (Germany); Friedrich, Joachim [Technische Universität Chemnitz, Straße der Nationen 62, D-09111 Chemnitz (Germany)

    2016-02-14

    The established quantum cluster equilibrium (QCE) approach is refined and applied to N-methylformamide (NMF) and its aqueous solution. The QCE method is split into two iterative cycles: one which converges to the liquid phase solution of the QCE equations and another which yields the gas phase. By comparing Gibbs energies, the thermodynamically stable phase at a given temperature and pressure is then chosen. The new methodology avoids metastable solutions and allows a different treatment of the mean-field interactions within the gas and liquid phases. These changes are of crucial importance for the treatment of binary mixtures. For the first time in a QCE study, the cis-trans-isomerism of a species (NMF) is explicitly considered. Cluster geometries and frequencies are calculated using density functional theory (DFT) and complementary coupled cluster single point energies are used to benchmark the DFT results. Independent of the selected quantum-chemical method, a large set of clusters is required for an accurate thermodynamic description of the binary mixture. The liquid phase of neat NMF is found to be dominated by the cyclic trans-NMF pentamer, which can be interpreted as a linear trimer that is stabilized by explicit solvation of two further NMF molecules. This cluster reflects the known hydrogen bond network preferences of neat NMF.

  6. Study of hydraulic properties of binary beads mixture as porous media in sustainable urban drainage system

    Science.gov (United States)

    Abdullah, Muhammad Faiz; Puay, How Tion; Zakaria, Nor Azazi

    2017-10-01

    Sustainable Urban Drainage System (SuDS) such as swales and rain gardens is showing growing popularity as a green technology for stormwater management and it can be used in all types of development to provide a natural approach to managing drainage. Soil permeability is a critical factor in selecting the right SuDS technique for a site. On this basis, we have set up a laboratory experiment to investigate the porosity and saturated hydraulic conductivity of single size and binary (two sizes) mixture using column-test as a preliminary investigation with two sets of glass beads with different sizes are used in this study. The porosity and saturated hydraulic conductivity for varies volume fraction of the course and fine glass beads were measured. It was found that the porosity of the binary mixture does not increase with the increment of the ratio of coarse to fine beads until the volume fraction of fine particles is equal to the coarse component. Saturated hydraulic conductivity result shows that the assumption of random packing was not achieved at the higher coarse ratio where most of the fine particles tend to sit at the bottom of the column forming separate layers which lower the overall hydraulic conductivity value.

  7. Methane-benzene binary mixture destruction in a reverse flow catalytic reactor

    International Nuclear Information System (INIS)

    Geng, Chen; Yong, Chi; Chunpeng, Pan; Yan, Jian-hua; Ni, Ming-Jian

    2010-01-01

    A reverse flow reactor (RFR) is a packed catalytic bed reactor in which feed flow direction is periodically reversed. When an exothermic catalytic combustion is conducted in a RFR, a hot zone is trapped in the center while both ends of the reactor act as regenerative heat exchanger. This enables an auto thermal operation at high temperatures even for feeds having a low adiabatic temperature rise. These features make RFR highly competitive for VOCs combustion. An experimental study of binary mixture purification in bench scale reverse flow reactor, with an inner diameter of 60 mm, has been carried out. Methane and benzene are chosen due to their different properties. The ignition temperature of methane is higher than any other hydrocarbons and benzene is widely used as solvent in industry. With periodic reversal feed, auto thermal catalytic combustion of very lean binary mixture can be achieved. When peak temperature in the hot zone reaches about 550 degree Celsius, both methane and benzene are well removed and little NOx or no other secondary pollutants are detected. The influence of several operation parameters, such as gas velocity, cycle period and methane-to-benzene ratio are discussed. A mathematical model has been developed and solved using a FORTRAN code, good correspondence being observed between both approaches. This provides a solution if VOC concentration in the contaminated air is too low to maintain an auto thermal operation, while natural gas (which is mainly methane) can be added as auxiliary fuel. (author)

  8. An Odor Interaction Model of Binary Odorant Mixtures by a Partial Differential Equation Method

    Directory of Open Access Journals (Sweden)

    Luchun Yan

    2014-07-01

    Full Text Available A novel odor interaction model was proposed for binary mixtures of benzene and substituted benzenes by a partial differential equation (PDE method. Based on the measurement method (tangent-intercept method of partial molar volume, original parameters of corresponding formulas were reasonably displaced by perceptual measures. By these substitutions, it was possible to relate a mixture’s odor intensity to the individual odorant’s relative odor activity value (OAV. Several binary mixtures of benzene and substituted benzenes were respectively tested to establish the PDE models. The obtained results showed that the PDE model provided an easily interpretable method relating individual components to their joint odor intensity. Besides, both predictive performance and feasibility of the PDE model were proved well through a series of odor intensity matching tests. If combining the PDE model with portable gas detectors or on-line monitoring systems, olfactory evaluation of odor intensity will be achieved by instruments instead of odor assessors. Many disadvantages (e.g., expense on a fixed number of odor assessors also will be successfully avoided. Thus, the PDE model is predicted to be helpful to the monitoring and management of odor pollutions.

  9. Volumetric and viscometric properties of binary and ternary mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate, monoethanolamine and water

    International Nuclear Information System (INIS)

    Yin, Yaran; Zhu, Chunying; Ma, Youguang

    2016-01-01

    Highlights: • Densities and viscosities of [Bmim][BF 4 ] + MEA + H 2 O solutions were measured. • Volumetric and viscometric properties were deduced from experimental results. • Intermolecular interactions were analysed by volumetric and viscometric properties. - Abstract: Densities and viscosities of binary {[Bmim][BF 4 ] + H 2 O}, {[Bmim][BF 4 ] + MEA}, (MEA + H 2 O) and ternary mixtures {[Bmim][BF 4 ] + MEA + H 2 O} were measured at T = (293.15–333.15) K. The volumetric and viscometric properties, such as excess molar volume V E , viscosity deviation Δη, and excess Gibbs energy of activation of viscous flow ΔG ∗E for all mixtures, and apparent molar volume, excess partial molar volume and Grunberg-Nissan interaction parameter G 12 for binary mixtures, were deduced from experimental results, and the intermolecular interactions in solutions were also analysed. The excess molar volumes were correlated using the Redlich-Kister polynomial equation for binary mixtures, and Singh et al. equation for the ternary mixture with corresponding binary parameters. The viscosities of binary and ternary solutions were respectively fitted by Jouyban-Acree equation and its extended equation at each measurement temperature, the correlated values are in good agreement with the corresponding experimental data.

  10. Impact of polyethyleneglycol addition on diffusion coefficients in binary ionic liquid electrolytes composed of dicationic ionic liquid and polyethyleneglycol.

    Science.gov (United States)

    Wu, Tzi-Yi; Su, Shyh-Gang; Chiu, Chuen-Lin; Kuo, Chung-Wen; Tung, Yi-Hsuan

    2018-02-01

    We conduct a comparative study of conductivity and diffusion coefficient of two dicationic ionic liquids (3,3'-(octane-1,8-diyl)bis(1-ethyl-3-imidazolium) bis(trifluoromethylsulfonyl)amide ([IMCI][TFSI], S1) and 3,3'-(2,2'-(ethane-1,2-diylbis(oxy))bis(ethane-2,1-diyl))bis(1-ethyl-3-imidazolium) bis(trifluoromethylsulfonyl)amide ([IMOI][TFSI], S2)) at various temperatures. The diffusion coefficients of cation and anion in ionic liquids are determined by using pulse gradient spin-echo nuclear magnetic resonance method. S2 shows lower viscosity, higher conductivity, and higher diffusion coefficient than those of S1. Moreover, the influence of polyethyleneglycol (PEG200, M w  = 200) addition in PEG200/IL binary solutions is investigated. PEG200/S1 binary solutions show lower viscosity, higher conductivity, and higher diffusion coefficient than those of neat S1. The experimental molar conductivity (Λ) of neat IL and PEG200/IL binary solutions is lower than that of the calculated molar conductivity (Λ NMR ) from pulse gradient spin-echo nuclear magnetic resonance method at various temperatures, indicating that not all the diffusion species belong to the ionic conduction. In other words, NMR diffusion measurements comprise charged and paired (without charge) ions. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Ion-molecule reactions in the binary mixture of ethylene oxide and trioxane, 2

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Arakawa, Kazuo; Sugiura, Toshio.

    1978-01-01

    The ion-molecule reactions in the binary mixture of ethylene oxide and trioxane have been studied with use of a modified time-of-flight mass spectrometer. As cross-reaction product ions, C 3 H 5 O 2 + , C 3 H 6 O 2 +sup(, and C**3**H**7**O**2**)+sup( were observed under the conditions of long delay times and elevated pressure. It was found that these ions are formed by the dissociation of unstable intermediate-complex resulting from the reaction of ethylene oxide molecular ion with trioxane. It was proposed that the complex is of cyclic structure in which positive charge is delocalized. From the consideration of isotopic distribution of the product ions in ethylene-d**4** oxide-trioxane mixtures, the skeletal structures of the product ions were investigated. The rate constants of the formation reactions of C**3**H**5**O**2**)+sup(, C**3**H**6**O**2**)+sup(, and C**3**H**7**O**2**)+sup( in ethylene oxide-trioxane mixtures were found to be 2.20 x 10)-10sup(, 2.61 x 10)-10sup(, and 1.74 x 10)-10sup( cm)3sup( molecule)-1sup(s)-1 , respectively. (auth.)

  12. Selective Adsorption and Selective Transport Diffusion of CO2-CH4 Binary Mixture in Coal Ultramicropores.

    Science.gov (United States)

    Zhao, Yongliang; Feng, Yanhui; Zhang, Xinxin

    2016-09-06

    The adsorption and diffusion of the CO2-CH4 mixture in coal and the underlying mechanisms significantly affect the design and operation of any CO2-enhanced coal-bed methane recovery (CO2-ECBM) project. In this study, bituminous coal was fabricated based on the Wiser molecular model and its ultramicroporous parameters were evaluated; molecular simulations were established through Grand Canonical Monte Carlo (GCMC) and Molecular Dynamic (MD) methods to study the effects of temperature, pressure, and species bulk mole fraction on the adsorption isotherms, adsorption selectivity, three distinct diffusion coefficients, and diffusivity selectivity of the binary mixture in the coal ultramicropores. It turns out that the absolute adsorption amount of each species in the mixture decreases as temperature increases, but increases as its own bulk mole fraction increases. The self-, corrected, and transport diffusion coefficients of pure CO2 and pure CH4 all increase as temperature or/and their own bulk mole fractions increase. Compared to CH4, the adsorption and diffusion of CO2 are preferential in the coal ultramicropores. Adsorption selectivity and diffusivity selectivity were simultaneously employed to reveal that the optimal injection depth for CO2-ECBM is 800-1000 m at 308-323 K temperature and 8.0-10.0 MPa.

  13. Structures of alkyl benzoate binary mixtures. A Kirkwood-Buff fluctuation theory study using UNIFAC.

    Science.gov (United States)

    Alcalde, Rafael; Aparicio, Santiago; García, Begoña; Leal, José M

    2005-10-27

    The structure of the alkyl benzoate + n-alkane, and + alkan-1-ol binary mixtures were analyzed according to the Kirkwood-Buff fluctuation theory on the basis of both the mixture properties measured over a wide temperature range and the activity coefficients calculated with the modified UNIFAC (Dortmund) model as well. Application of this model reveals that both the microheterogeneous structure and the clustering effects are strongly dependent on the chain length of the n-alkane and alkan-1-ol cosolvents. Knowledge of the local composition around each type of molecule is drawn from the Kirkwood-Buff integrals and the excess (or deficit) molecules aggregated around a central one. The rather high values of the integrals evaluated for some of these systems provide first-hand evidence for phase splitting. The conclusions drawn support previous analyses and confirm the adequacy of the methodology put forward for studying liquid mixtures at microscopic level; easily measurable experimental properties can advantageously be used with the fluctuation theory.

  14. Displaced dynamics of binary mixtures in linear and nonlinear optical lattices

    Science.gov (United States)

    Sekh, Golam Ali; Salerno, Mario; Saha, Aparna; Talukdar, Benoy

    2012-02-01

    The dynamical behavior of matter-wave solitons of two-component Bose-Einstein condensates (BEC) in combined linear and nonlinear optical lattices (OLs) is investigated. In particular, the dependence of the frequency of the oscillating dynamics resulting from initially slightly displaced components is investigated both analytically, by means of a variational effective potential approach for the reduced collective coordinate dynamics of the soliton, and numerically, by direct integrations of the mean field equations of the BEC mixture. We show that for small initial displacements binary solitons can be viewed as point masses connected by elastic springs of strengths related to the amplitude of the OL and to the intra- and interspecies interactions. Analytical expressions of symmetric and antisymmetric mode frequencies are derived and occurrence of beatings phenomena in the displaced dynamics is predicted. These expressions are shown to give a very good estimation of the oscillation frequencies for different values of the intraspecies interatomic scattering length, as confirmed by direct numerical integrations of the mean field Gross-Pitaevskii equations (GPE) of the mixture. The possibility to use displaced dynamics for indirect measurements of BEC mixture characteristics such as number of atoms and interatomic interactions is also suggested.

  15. Mutual diffusion of binary liquid mixtures containing methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride

    Energy Technology Data Exchange (ETDEWEB)

    Guevara-Carrion, Gabriela; Janzen, Tatjana; Muñoz-Muñoz, Y. Mauricio; Vrabec, Jadran, E-mail: jadran.vrabec@uni-paderborn.de [Thermodynamics and Energy Technology, University of Paderborn, 33098 Paderborn (Germany)

    2016-03-28

    Mutual diffusion coefficients of all 20 binary liquid mixtures that can be formed out of methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride without a miscibility gap are studied at ambient conditions of temperature and pressure in the entire composition range. The considered mixtures show a varying mixing behavior from almost ideal to strongly non-ideal. Predictive molecular dynamics simulations employing the Green-Kubo formalism are carried out. Radial distribution functions are analyzed to gain an understanding of the liquid structure influencing the diffusion processes. It is shown that cluster formation in mixtures containing one alcoholic component has a significant impact on the diffusion process. The estimation of the thermodynamic factor from experimental vapor-liquid equilibrium data is investigated, considering three excess Gibbs energy models, i.e., Wilson, NRTL, and UNIQUAC. It is found that the Wilson model yields the thermodynamic factor that best suits the simulation results for the prediction of the Fick diffusion coefficient. Four semi-empirical methods for the prediction of the self-diffusion coefficients and nine predictive equations for the Fick diffusion coefficient are assessed and it is found that methods based on local composition models are more reliable. Finally, the shear viscosity and thermal conductivity are predicted and in most cases favorably compared with experimental literature values.

  16. An improved molecular dynamics algorithm to study thermodiffusion in binary hydrocarbon mixtures

    Science.gov (United States)

    Antoun, Sylvie; Saghir, M. Ziad; Srinivasan, Seshasai

    2018-03-01

    In multicomponent liquid mixtures, the diffusion flow of chemical species can be induced by temperature gradients, which leads to a separation of the constituent components. This cross effect between temperature and concentration is known as thermodiffusion or the Ludwig-Soret effect. The performance of boundary driven non-equilibrium molecular dynamics along with the enhanced heat exchange (eHEX) algorithm was studied by assessing the thermodiffusion process in n-pentane/n-decane (nC5-nC10) binary mixtures. The eHEX algorithm consists of an extended version of the HEX algorithm with an improved energy conservation property. In addition to this, the transferable potentials for phase equilibria-united atom force field were employed in all molecular dynamics (MD) simulations to precisely model the molecular interactions in the fluid. The Soret coefficients of the n-pentane/n-decane (nC5-nC10) mixture for three different compositions (at 300.15 K and 0.1 MPa) were calculated and compared with the experimental data and other MD results available in the literature. Results of our newly employed MD algorithm showed great agreement with experimental data and a better accuracy compared to other MD procedures.

  17. Thermodynamic scaling of the shear viscosity of Mie n-6 fluids and their binary mixtures.

    Science.gov (United States)

    Delage-Santacreu, Stephanie; Galliero, Guillaume; Hoang, Hai; Bazile, Jean-Patrick; Boned, Christian; Fernandez, Josefa

    2015-05-07

    In this work, we have evaluated the applicability of the so-called thermodynamic scaling and the isomorph frame to describe the shear viscosity of Mie n-6 fluids of varying repulsive exponents (n = 8, 12, 18, 24, and 36). Furthermore, the effectiveness of the thermodynamic scaling to deal with binary mixtures of Mie n-6 fluids has been explored as well. To generate the viscosity database of these fluids, extensive non-equilibrium molecular dynamics simulations have been performed for various thermodynamic conditions. Then, a systematic approach has been used to determine the gamma exponent value (γ) characteristic of the thermodynamic scaling approach for each system. In addition, the applicability of the isomorph theory with a density dependent gamma has been confirmed in pure fluids. In both pure fluids and mixtures, it has been found that the thermodynamic scaling with a constant gamma is sufficient to correlate the viscosity data on a large range of thermodynamic conditions covering liquid and supercritical states as long as the density is not too high. Interestingly, it has been obtained that, in pure fluids, the value of γ is directly proportional to the repulsive exponent of the Mie potential. Finally, it has been found that the value of γ in mixtures can be deduced from those of the pure component using a simple logarithmic mixing rule.

  18. Thermodynamic scaling of the shear viscosity of Mie n-6 fluids and their binary mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Delage-Santacreu, Stephanie [Laboratoire de Mathématiques et leurs Applications (UMR-5142 with CNRS), Université de Pau et des Pays de l’Adour, BP 1155, F-64013 PAU Cedex (France); Galliero, Guillaume, E-mail: guillaume.galliero@univ-pau.fr; Hoang, Hai; Bazile, Jean-Patrick; Boned, Christian [Laboratoire des Fluides Complexes et leurs Reservoirs (UMR-5150 with CNRS and TOTAL), Université de Pau et des Pays de l’Adour, BP 1155, F-64013 PAU Cedex (France); Fernandez, Josefa [Laboratorio de Propiedades Termofisicas, Universidade Santiago de Compostela, Campus Vida, E-15782 Santiago de Compostela (Spain)

    2015-05-07

    In this work, we have evaluated the applicability of the so-called thermodynamic scaling and the isomorph frame to describe the shear viscosity of Mie n-6 fluids of varying repulsive exponents (n = 8, 12, 18, 24, and 36). Furthermore, the effectiveness of the thermodynamic scaling to deal with binary mixtures of Mie n-6 fluids has been explored as well. To generate the viscosity database of these fluids, extensive non-equilibrium molecular dynamics simulations have been performed for various thermodynamic conditions. Then, a systematic approach has been used to determine the gamma exponent value (γ) characteristic of the thermodynamic scaling approach for each system. In addition, the applicability of the isomorph theory with a density dependent gamma has been confirmed in pure fluids. In both pure fluids and mixtures, it has been found that the thermodynamic scaling with a constant gamma is sufficient to correlate the viscosity data on a large range of thermodynamic conditions covering liquid and supercritical states as long as the density is not too high. Interestingly, it has been obtained that, in pure fluids, the value of γ is directly proportional to the repulsive exponent of the Mie potential. Finally, it has been found that the value of γ in mixtures can be deduced from those of the pure component using a simple logarithmic mixing rule.

  19. CONSOLIDATION AND COMPACTION OF POWDER MIXTURES .1. BINARY-MIXTURES OF SAME PARTICLE-SIZE FRACTIONS OF DIFFERENT TYPES OF CRYSTALLINE LACTOSE

    NARCIS (Netherlands)

    RIEPMA, KA; LERK, CF; DEBOER, AH; BOLHUIS, GK; KUSSENDRAGER, KD

    1990-01-01

    Binary powder mixtures of four different types of crystalline lactose: alpha-lactose monohydrate, anhydrous alpha-lactose, roller-dried beta-lactose and crystalline beta-lactose, were compressed into tablets. The results showed a proportional intercorrelation of the crushing strength and internal

  20. ANALYSIS OF THE KINETICS OF SOLVOLYSIS OF P-NITROPHENYLSULFONYLMETHYL PERCHLORATE IN BINARY ALCOHOLIC MIXTURES IN TERMS OF THE THERMODYNAMIC PROPERTIES OF THE SOLVENT MIXTURES

    NARCIS (Netherlands)

    Wijnen, J W; Engberts, J B F N; Blandamer, Michael J

    Rate constants are reported for the solvolysis of p-nitrophenylsulfonylmethyl perchlorate in binary ethanolic and methanolic mixtures at 298.2 K. Co-solvents include hydrocarbons, chlorinated hydrocarbons and 1,4-dioxane. The kinetic data are examined in terms of the effect of decreasing mole

  1. Swelling and mechanical properties of hydrogels composed of binary blends of inter-linked pH-responsive microgel particles.

    Science.gov (United States)

    Milani, Amir H; Bramhill, Jane; Freemont, Anthony J; Saunders, Brian R

    2015-04-07

    We show that a new type of hydrogel can be prepared by covalently inter-linking binary blends of microgel (MG) particles and that the swelling ratio and modulus of the gels can be predicted from their composition. In previous work we established that physical gels of glycidyl methacrylate (GMA) functionalised poly(methyl methacrylate-co-methacrylic acid-co-ethyleneglycol dimethacrylate) microgel particles (GMA-MG) could be covalently inter-linked to give hydrogels, termed doubly crosslinked microgels, DX MGs. We build on this concept here by investigating the properties of DX MGs containing binary blends of GMA-MG particles and glycidyl oligo(ether ester) acrylate-functionalised microgel particles (GOE-MG). These new hydrogels were assembled by inter-linking nanoscale MG building blocks in the absence of small molecule monomers or crosslinkers. The volume fraction of GMA-MG particles used to prepare the GOE-GMA DX MGs was systematically varied. Rheology data showed that inclusion of GMA-MG and GOE-MG within the GOE-GMA DX MGs increased the modulus and yield strain, respectively, compared to the values measured for the respective physical gels. The data for the covalent GOE-GMA DX MG gels showed that the ductility increased with increasing GOE-MG content. GOE provided covalent inter-linking of the MG particles and also acted as a lubricant between particles due to its low Tg. By demonstrating compositionally determined swelling and mechanical properties for DX MG gels prepared using binary blends of MG particles, this study introduces a new, widely applicable, hydrogel construction assembly concept that is not available for conventional hydrogels.

  2. Study of thermodynamic and acoustic behaviour of nicotinic acid in binary aqueous mixtures of D-lactose

    Science.gov (United States)

    Sharma, Ravi; Thakur, R. C.

    2017-07-01

    In the present study, the thermodynamic properties such as partial molar volumes, partial molar expansibilities, partial molar compressibilities, partial molar heat capacities and isobaric thermal expansion coefficient of different solutions of nicotinic acid in binary aqueous mixtures of D-lactose have been determined at different temperatures (298.15, 303.15, 308.15, 313.15) K. Masson's equation is used to interpret the data in terms of solute-solute and solute-solvent interactions. In the present study it has been found that nicotinic acid behaves as structure maker in aqueous and binary aqueous mixtures of D-lactose.

  3. Thermodynamic study of copper sulphate and zinc sulphate in water and binary aqueous mixtures of propylene glycol

    OpenAIRE

    R. C. Thakur; Ravi Sharma; Meenakshi; Ashish Kumar

    2015-01-01

    Partial molar volumes of copper sulphate and zinc sulphate have been determined in water and binary aqueous mixtures of propylene glycol (2,4,6 and 8% by weight of propylene glycol) at 303.15 K with the help of density measurements. Effect of temperature on the partial molar volumes was also analysed for these salts in water and binary aqueous mixtures of propylene glycol. Results obtained have been analysed by Masson’s equation and the experimental values of slopes and partial molar volumes ...

  4. Simultaneous Detection and Estimation of Catechol, Hydroquinone, and Resorcinol in Binary and Ternary Mixtures Using Electrochemical Techniques

    Directory of Open Access Journals (Sweden)

    Md. Uzzal Hossain

    2015-01-01

    Full Text Available Cyclic voltammetry (CV and differential pulse voltammetry (DPV were performed with a glassy carbon electrode (GCE modified with polyglutamic acid (PGA on the three dihydroxybenzene isomers, catechol (CT, hydroquinone (HQ, and resorcinol (RS. At bare GCE, these isomers exhibited voltammograms with highly overlapped redox peaks that impeded their simultaneous detection in binary and ternary mixtures. On the contrary, at PGA modified GCE binary and ternary mixtures of the dihydroxybenzene isomers showed well-resolved redox peaks in both CV and DPV experiments. This resolving ability of PGA modified GCE proves its potential to be exploited as an electrochemical sensor for the simultaneous detection of these isomers.

  5. Mass-dependence of self-diffusion coefficients in disparate-mass binary fluid mixtures

    Directory of Open Access Journals (Sweden)

    I. Binas

    2009-01-01

    Full Text Available Self-diffusion coefficients of a binary fluid mixture with components differing only in their particle masses are studied, in particular the case when mass ratio μ of light and heavy particles tends to zero. These coefficients were calculated within the memory function formalism, using the systematic subsequence of approximations for the relaxation times of velocity autocorrelation function. We obtained a general relation for the self-diffusion coefficients which show polynomial dependence on the mass ratio μ. The obtained expression has a correct Brownian limit. We developed the hierarchy of approximations for the self-diffusion coefficients that tends to an exact result from above and below when the order of approximations increases.

  6. Vapor-Liquid Equilibrium Measurements of the Binary R32+R125 Refrigerant Mixture

    Science.gov (United States)

    Higashi, Yukihiro; Miyake, Takeshi; Fujii, Ken-Ichi

    Vapor-liquid equilibrium (VLE) data of the binary R32+R125 refrigerant mixture including R410A (50mass% R32 + 50mass% R125) were obtained by the circulation-type experimental apparatus with a liquid-bath thermostat. VLE measurements were carried out in the temperatures between 263.15 K and 318.15 K and in the pressures between 505 kPa and 2724 kPa. The experimental uncertainties of temperature, pressure, and composition measurements were estimated to be within 3 mK, 0.1 %, and 0.4 %, respectively. The present data were compared with reported experimental data against the REFPROP 6.01 as well as REFPROP 7.0 calculation results.

  7. Beyond mean-field properties of binary dipolar Bose mixtures at low temperatures

    Science.gov (United States)

    Pastukhov, Volodymyr

    2017-02-01

    We rigorously analyze the low-temperature properties of homogeneous three-dimensional two-component Bose mixture with dipole-dipole interaction. For such a system the effective hydrodynamic action that governs the behavior of low-energy excitations is derived. The infrared structure of the exact single-particle Green's functions is obtained in terms of macroscopic parameters, namely the inverse compressibility and the superfluid density matrices. Within the one-loop approximation we calculate some of the most relevant observable quantities and give the beyond mean-field stability condition for the binary dipolar Bose gas in the dilute limit. A brief variational derivation of the coupled equations that describe macroscopic hydrodynamics of the system in the external nonuniform potential at zero temperature is presented.

  8. Phase behavior of binary polybutadiene copolymer mixtures as an example of weakly interacting polymers

    CERN Document Server

    Schwahn, D

    2002-01-01

    Binary blends of statistical polybutadiene copolymers of different vinyl content and molar volume were explored by small-angle neutron scattering. These samples represent the most simple class of statistical copolymer mixtures. In spite of this simplicity, changes in vinyl content, molar volume, and deuterium and hydrogen content of the chains give rise to strong effects; phase separation occurs from minus 230 C to more than plus 200 C and can even reverse from an enthalpically driven one at low temperatures to an entropically driven one at high temperatures. The entropic and enthalpic terms of the Flory-Huggins parameter as determined from the experiment are in excellent agreement with lattice cluster theory calculations. (orig.)

  9. Prediction of excess molar volumes of selected binary mixtures from refractive index data

    Directory of Open Access Journals (Sweden)

    Vuksanović Jelena M.

    2014-01-01

    Full Text Available The excess molar volumes of twenty two binary mixtures containing various groups of organic compounds: alcohols (ethanol, 1-propanol, 1,2-propanediol, 1,3-propanediol and glycerol, ketone (acetone, ester (butyl lactate, lactam (N-methyl-2-pyrrolidone, PEGs (PEG 200, PEG 400 and aromatics (benzene, toluene and pyridine were predicted from the refractive index data, using three types of equations coupled with several mixing rules for refractive index calculations: the Lorentz-Lorenz, Dale-Gladstone, Eykman, Arago-Biot, Newton, and Oster. The obtained results were analysed in terms of the applied equation and mixing rule and the nature of interactions between the mixtures’ components. [Projekat Ministarstva nauke Republike Srbije, br. 172063

  10. Generalized Einstein relation for the mutual diffusion coefficient of a binary fluid mixture.

    Science.gov (United States)

    Felderhof, B U

    2017-08-21

    The method employed by Einstein to derive his famous relation between the diffusion coefficient and the friction coefficient of a Brownian particle is used to derive a generalized Einstein relation for the mutual diffusion coefficient of a binary fluid mixture. The expression is compared with the one derived by de Groot and Mazur from irreversible thermodynamics and later by Batchelor for a Brownian suspension. A different result was derived by several other workers in irreversible thermodynamics. For a nearly incompressible solution, the generalized Einstein relation agrees with the expression derived by de Groot and Mazur. The two expressions also agree to first order in solute density. For a Brownian suspension, the result derived from the generalized Smoluchowski equation agrees with both expressions.

  11. The influence of thermodynamic self-consistency on the phase behaviour of symmetric binary mixtures

    CERN Document Server

    Scholl-Paschinger, E; Kahl, G

    2004-01-01

    We have investigated the phase behaviour of a symmetric binary mixture with particles interacting via hard-core Yukawa potentials. To calculate the thermodynamic properties we have used the mean spherical approximation (MSA), a conventional liquid state theory, and the closely related self-consistent Ornstein-Zernike approximation which is defined via an MSA-type closure relation, requiring, in addition, thermodynamic self-consistency between the compressibility and the energy-route. We investigate on a quantitative level the effect of the self-consistency requirement on the phase diagram and on the critical behaviour and confirm the existence of three archetypes of phase diagram, which originate from the competition between the first order liquid/vapour transition and the second order demixing transition.

  12. Simultaneous determination of a binary mixture of pantoprazole sodium and itopride hydrochloride by four spectrophotometric methods

    Science.gov (United States)

    Ramadan, Nesrin K.; El-Ragehy, Nariman A.; Ragab, Mona T.; El-Zeany, Badr A.

    2015-02-01

    Four simple, sensitive, accurate and precise spectrophotometric methods were developed for the simultaneous determination of a binary mixture containing Pantoprazole Sodium Sesquihydrate (PAN) and Itopride Hydrochloride (ITH). Method (A) is the derivative ratio method (1DD), method (B) is the mean centering of ratio spectra method (MCR), method (C) is the ratio difference method (RD) and method (D) is the isoabsorptive point coupled with third derivative method (3D). Linear correlation was obtained in range 8-44 μg/mL for PAN by the four proposed methods, 8-40 μg/mL for ITH by methods A, B and C and 10-40 μg/mL for ITH by method D. The suggested methods were validated according to ICH guidelines. The obtained results were statistically compared with those obtained by the official and a reported method for PAN and ITH, respectively, showing no significant difference with respect to accuracy and precision.

  13. Ultrasonic absorption and velocity dispersion of binary mixture liquid crystal MBBA/EBBA

    International Nuclear Information System (INIS)

    Choi, K.

    1979-01-01

    The effect of phase transitions and the partial magnetic alignment for liquid crystal molecules on the ultrasonic absorption and velocity dispersion has been investigated. The binary mixture of Shiff base liquid crystals MBBA/EBBA (55:45 mole %) showed anomalous ultrasonic absorption and velocity dispersion at eutectic (Tsub(m) = -20 0 C) and clearing point (Tsub(c) = 50 0 C) at the frequency range of 5 MHz, 10MHz, 15MHz and 30 MHz. The experimental data were analyzed in terms of relaxation time and Fixman theory. The anisotropy of the propagation velocity due to the magnetic alignment was about 0.9% (the deviation between velocities propagating parallel and perpendicular to the applied field). (author)

  14. Straightforward dimensionless experimental formulae for flash point of binary mixtures of two flammable components

    Directory of Open Access Journals (Sweden)

    Hristova Mariana

    2012-01-01

    Full Text Available Dimensionless experimental formulae based on a rational reciprocal function for correlation of flashpoint data of binary mixtures of two flammable components have been developed. The formulae are based on data obtained from flash-point experiments. The proposed approach requires only two coefficients, molar fraction of components and flashpoint temperatures of the pure flammable components to be known in advance. Literature data were used for formulae verification and validation obtained results indicate that accuracy is comparable and to some extent better than that of conventional flash point prediction models. Dimensional analysis and scaling of data have been performed in order to define the correct construction of the equation fitting flash-point data in dimensionless form using the independent variables suggested by Catoire. Stefan number relevant flash-point of a single compound or a blend has been defined.

  15. A New Simplified Local Density Model for Adsorption of Pure Gases and Binary Mixtures

    Science.gov (United States)

    Hasanzadeh, M.; Dehghani, M. R.; Feyzi, F.; Behzadi, B.

    2010-12-01

    Adsorption modeling is an important tool for process simulation and design. Many theoretical models have been developed to describe adsorption data for pure and multicomponent gases. The simplified local density (SLD) approach is a thermodynamic model that can be used with any equation of state and offers some predictive capability with adjustable parameters for modeling of slit-shaped pores. In previous studies, the SLD model has been utilized with the Lennard-Jones potential function for modeling of fluid-solid interactions. In this article, we have focused on application of the Sutherland potential function in an SLD-Peng-Robinson model. The advantages and disadvantages of using the new potential function for adsorption of methane, ethane, carbon dioxide, nitrogen, and three binary mixtures on two types of activated carbon are illustrated. The results have been compared with previous models. It is shown that the new SLD model can correlate adsorption data for different pressures and temperatures with minimum error.

  16. Binary mixtures of waxy wheat and conventional wheat as measured by NIR reflectance.

    Science.gov (United States)

    Delwiche, Stephen R; Graybosch, Robert A

    2016-01-01

    Waxy wheat contains very low concentration (generally industries seek to have a rapid technique to ensure the purity of identity preserved waxy wheat lots. Near infrared (NIR) reflectance spectroscopy, a technique widely used in the cereals industry for proximate analysis, is a logical candidate for measuring contamination level and thus is the subject of this study. Two sets of wheat samples, harvested, prepared and scanned one year apart, were used to evaluate the NIR concept. One year consisted of nine pairs of conventional:waxy preparations, with each preparation consisting of 29 binary mixtures ranging in conventional wheat fraction (by weight) of 0-100% (261 spectral samples). The second year was prepared in the same fashion, with 12 preparations, thus producing 348 spectral samples. One year's samples were controlled for protein content and moisture level between pair components in order to avoid the basis for the conventional wheat fraction models being caused by something other than spectral differences attributed to waxy and nonwaxy endosperm. Likewise the second year was controlled by selection of conventional wheat for mixture preparation based on either protein content or cluster analysis of principal components of candidate spectra. Partial least squares regression, one and two-term linear regression, and support vector machine regression models were examined. Validation statistics arising from sets within the same year or across years were remarkably similar, as were those among the three regression types. A single wavelength on second derivative transformed spectra, namely 2290 nm, was effective at estimating the mixture level by weight, with standard errors of performance in the 6-9% range. Thus, NIR spectroscopy may be used for measuring conventional hard wheat 'contamination' in waxy wheat at mixture levels above 10% w/w. Published by Elsevier B.V.

  17. Simulation of the (vapor + liquid) equilibria of binary mixtures of benzene, cyclohexane, and hydrogen

    International Nuclear Information System (INIS)

    Carrero-Mantilla, J.

    2008-01-01

    Molecular simulations of the (vapor + liquid) equilibria (VLE) for benzene, cyclohexane, and (benzene + hydrogen) and (cyclohexane + hydrogen) were carried out using the Gibbs-ensemble Monte Carlo method with configurational bias. The Buckingham exponential six (exp-6) potential was used for the site-site interactions with no binary interaction parameters; benzene and cyclohexane were described with six interaction sites, and hydrogen with a single site. Simulation results, density, pressure, and vaporization enthalpy for benzene and cyclohexane were in reasonable agreement with experimental data, but critical pressures obtained from extrapolation of the VLE results did not match the experimental values. For (benzene + hydrogen) and (cyclohexane + hydrogen) mixtures mole fractions from simulation were compared with experimental data, the results for liquid phase were in closer agreement with experiment than the results for vapor phase. For the mixtures, results from the PSRK equation of state (PSRK-EOS) predicted the mole fractions for both phases, also vapor densities from molecular simulation were in close agreement with PSRK-EOS. Additionally, the Henry's law constant (K H ) for hydrogen was calculated in separate simulations using test particle insertions, and qualitative agreement with values from experimental VLE data was obtained. For the (benzene + hydrogen) system K H results from PSRK-EOS were closer to experiment than the results from simulation, but, for the (cyclohexane + hydrogen) system results from both methods had similar deviations from experiment. The results for pure substance and mixtures indicate that the combination of the three molecular models used for benzene, cyclohexane, and hydrogen is valid for the simulation of the VLE of their mixtures

  18. Surface Tension of Nonideal Binary Liquid Mixtures as a Function of Composition.

    Science.gov (United States)

    Nath

    1999-01-01

    The composition dependence of the surface tension of highly nonideal organic-organic and aqueous-organic nonelectrolyte solutions is described, based on the assumption that the surface layer can be treated as a separate phase located between vapor and bulk liquid phases. The Wilson, NRTL, and UNIFAC methods are used for activity coefficients of surface and bulk phases and three techniques for calculation of molar surface areas, based on Paquette areas, Rasmussen areas, and a Langmuir-type approach are tested. Comparisons of the calculated surface tensions with experimental data yield mean absolute errors, in the best case, of less than 2.5% for the systems studied, all of which exhibit highly nonideal behavior. The surface tension predictions are found to be extremely sensitive to the values of the molar surface areas used in the computation. A Langmuir-type adsorption model is formulated to determine the surface mole fractions from a knowledge of the mixture surface tension as a function of bulk composition. A novel procedure is developed to obtain the partial molar surface area of the larger organic component as a function of composition in binary aqueous-organic systems, assuming that the two components are very dissimilar in size, and that deviations in the partial molar surface area of the smaller component (water) from its pure component molar surface area contribute negligibly to the total molar surface area of the mixture. This removes the approximation of equality of partial and pure component molar surface area for the larger organic component. Use of the Langmuir-type approach with partial molar surface areas improves surface tension predictions of highly nonideal aqueous-organic mixtures by 20% over use of pure component molar surface areas. It is an important first step in the development of a thermodynamically consistent theory of surfaces for liquid mixtures based on an accurate determination of the composition dependence of partial molar surface

  19. Microscopic Theory of Coupled Slow Activated Dynamics in Glass-Forming Binary Mixtures.

    Science.gov (United States)

    Zhang, Rui; Schweizer, Kenneth S

    2018-04-05

    The Elastically Collective Nonlinear Langevin Equation theory for one-component viscous liquids and suspensions is generalized to treat coupled slow activated relaxation and diffusion in glass-forming binary sphere mixtures of any composition, size ratio, and interparticle interactions. A trajectory-level dynamical coupling parameter concept is introduced to construct two coupled dynamic free energy functions for the smaller penetrant and larger matrix particle. A two-step dynamical picture is proposed where the first-step process involves matrix-facilitated penetrant hopping quantified in a self-consistent manner based on a temporal coincidence condition. After penetrants dynamically equilibrate, the effectively one-component matrix particle dynamics is controlled by a new dynamic free energy (second-step process). Depending on the time scales associated with the first- and second-step processes, as well as the extent of matrix-correlated facilitation, distinct physical scenarios are predicted. The theory is implemented for purely hard-core interactions, and addresses the glass transition based on variable kinetic criteria, penetrant-matrix coupled activated relaxation, self-diffusion of both species, dynamic fragility, and shear elasticity. Testable predictions are made. Motivated by the analytic ultralocal limit idea derived for pure hard sphere fluids, we identify structure-thermodynamics-dynamics relationships. As a case study for molecule-polymer thermal mixtures, the chemically matched fully miscible polystyrene-toluene system is quantitatively studied based on a predictive mapping scheme. The resulting no-adjustable-parameter results for toluene diffusivity and the mixture glass transition temperature are in good agreement with experiment. The theory provides a foundation to treat diverse dynamical problems in glass-forming mixtures, including suspensions of colloids and nanoparticles, polymer-molecule liquids, and polymer nanocomposites.

  20. Contrasting two different interpretations of the dynamics in binary glass forming mixtures

    Science.gov (United States)

    Valenti, S.; Capaccioli, S.; Ngai, K. L.

    2018-02-01

    In a series of papers on binary glass-forming mixtures of tripropyl phosphate (TPP) with polystyrene (PS), Kahlau et al. [J. Chem. Phys. 140, 044509 (2014)] and Bock et al. [J. Chem. Phys. 139, 064508 (2013); J. Chem. Phys. 140, 094505 (2014); and J. Non-Cryst. Solids 407, 88-97 (2015)] presented the data on the dynamics of the two components studied over the entire composition range by several experimental methods. From these sets of data, obtained by multiple experimental techniques on mixtures with a large difference ΔTg ≈ 200 K between the glass transition temperatures of two starting glass formers, they obtained two α-relaxations, α1 and α2. The temperature dependence of the slower α1 is Vogel-Fulcher like, but the faster α2 is Arrhenius. We have re-examined their data and show that their α2-relaxation is the Johari-Goldstein (JG) β-relaxation with Arrhenius T-dependence admixed with a true α2-relaxation having a stronger temperature dependence. In support of our interpretation of their data, we made dielectric measurements at elevated pressures P to show that the ratio of the α1 and α2 relaxation times, τα1(T,P)/τα2(T,P), is invariant to variations of T and P, while τα1(T,P) is kept constant. This property proves unequivocally that the α2-relaxation is the JG β-relaxation, the precursor of the α1-relaxation. Subsequently, the true but unresolved α2-relaxation is recovered, and its relaxation times with much stronger temperature dependence are deduced, as expected for the α-relaxation of the TPP component. The results are fully compatible with those found in another binary mixture of methyltetrahydrofuran with tristyrene and PS with ΔTg ≈ 283 K, even larger than ΔTg ≈ 200 K of the mixture of TPP with PS, and in several polymer blends. The contrast between the two very different interpretations brought out in this paper is deemed beneficial for further progress in this research area.

  1. Application of wavelet and Fuorier transforms as powerful alternatives for derivative spectrophotometry in analysis of binary mixtures: A comparative study

    Science.gov (United States)

    Hassan, Said A.; Abdel-Gawad, Sherif A.

    2018-02-01

    Two signal processing methods, namely, Continuous Wavelet Transform (CWT) and the second was Discrete Fourier Transform (DFT) were introduced as alternatives to the classical Derivative Spectrophotometry (DS) in analysis of binary mixtures. To show the advantages of these methods, a comparative study was performed on a binary mixture of Naltrexone (NTX) and Bupropion (BUP). The methods were compared by analyzing laboratory prepared mixtures of the two drugs. By comparing performance of the three methods, it was proved that CWT and DFT methods are more efficient and advantageous in analysis of mixtures with overlapped spectra than DS. The three signal processing methods were adopted for the quantification of NTX and BUP in pure and tablet forms. The adopted methods were validated according to the ICH guideline where accuracy, precision and specificity were found to be within appropriate limits.

  2. Density, Viscosity and Surface Tension of Binary Mixtures of 1-Butyl-1-Methylpyrrolidinium Tricyanomethanide with Benzothiophene.

    Science.gov (United States)

    Domańska, Urszula; Królikowska, Marta; Walczak, Klaudia

    2014-01-01

    The effects of temperature and composition on the density and viscosity of pure benzothiophene and ionic liquid (IL), and those of the binary mixtures containing the IL 1-butyl-1-methylpyrrolidynium tricyanomethanide ([BMPYR][TCM] + benzothiophene), are reported at six temperatures (308.15, 318.15, 328.15, 338.15, 348.15 and 358.15) K and ambient pressure. The temperature dependences of the density and viscosity were represented by an empirical second-order polynomial and by the Vogel-Fucher-Tammann equation, respectively. The density and viscosity variations with compositions were described by polynomials. Excess molar volumes and viscosity deviations were calculated and correlated by Redlich-Kister polynomial expansions. The surface tensions of benzothiophene, pure IL and binary mixtures of ([BMPYR][TCM] + benzothiophene) were measured at atmospheric pressure at four temperatures (308.15, 318.15, 328.15 and 338.15) K. The surface tension deviations were calculated and correlated by a Redlich-Kister polynomial expansion. The temperature dependence of the interfacial tension was used to evaluate the surface entropy, the surface enthalpy, the critical temperature, the surface energy and the parachor for pure IL. These measurements have been provided to complete information of the influence of temperature and composition on physicochemical properties for the selected IL, which was chosen as a possible new entrainer in the separation of sulfur compounds from fuels. A qualitative analysis on these quantities in terms of molecular interactions is reported. The obtained results indicate that IL interactions with benzothiophene are strongly dependent on packing effects and hydrogen bonding of this IL with the polar solvent.

  3. The Spatiotemporal Oscillations of Order Parameter for Isothermal Model of the Surface-Directed Spinodal Decomposition in Bounded Binary Mixtures

    Directory of Open Access Journals (Sweden)

    Igor B. Krasnyuk

    2009-01-01

    Full Text Available The asymptotical behavior of order parameter in confined binary mixture is considered in one-dimensional geometry. The interaction between bulk and surface forces in the mixture is investigated. Its established conditions are when the bulk spinodal decomposition may be ignored and when the main role in the process of formation of the oscillating asymptotic periodic spatiotemporal structures plays the surface-directed spinodal decomposition which is modelled by nonlinear dynamical boundary conditions.

  4. Non-equilibrium theory employing enthalpy-based equation of state for binary solid and porous mixtures

    Science.gov (United States)

    Nayak, B.; Menon, S. V. G.

    2018-03-01

    A generalized enthalpy-based equation of state, which includes thermal electron excitations and non-equilibrium thermal energies, is formulated for binary solid and porous mixtures. Our approach gives rise to an extra contribution to mixture volume, in addition to those corresponding to average mixture parameters. This excess term involves the difference of thermal enthalpies of the two components, which depend on their individual temperatures. We propose to use the Hugoniot of the components to compute non-equilibrium temperatures in the mixture. These are then compared with the average temperature obtained from the mixture Hugoniot, thereby giving an estimate of non-equilibrium effects. The Birch-Murnaghan model for the zero-temperature isotherm and a linear thermal model are then used for applying the method to several mixtures, including one porous case. Comparison with experimental data on the pressure-volume Hugoniot and shock speed versus particle speed shows good agreement.

  5. Ecotoxicity of binary mixtures of Microcystis aeruginosa and insecticides to Daphnia pulex

    International Nuclear Information System (INIS)

    Asselman, J.; Janssen, C.R.; Smagghe, G.; De Schamphelaere, K.A.C.

    2014-01-01

    In aquatic ecosystems, mixtures of chemical and natural stressors can occur which may significantly complicate risk assessment approaches. Here, we show that effects of binary combinations of four different insecticides and Microcystis aeruginosa, a toxic cyanobacteria, on Daphnia pulex exhibited distinct interaction patterns. Combinations with chlorpyrifos and tetradifon caused non-interactive effects, tebufenpyrad caused an antagonistic interaction and fenoyxcarb yielded patterns that depended on the reference model used (i.e. synergistic with independent action, additive with concentration addition). Our results demonstrate that interactive effects cannot be generalised across different insecticides, not even for those targeting the same biological pathway (i.e. tebufenpyrad and tetradifon both target oxidative phosphorylation). Also, the concentration addition reference model provided conservative predictions of effects in all investigated combinations for risk assessment. These predictions could, in absence of a full mechanistic understanding, provide a meaningful solution for managing water quality in systems impacted by both insecticides and cyanobacterial blooms. - Highlights:: • 2 of 4 insecticide-Microcystis combinations showed no interactive effect on Daphnia. • One insecticide showed antagonistic deviation patterns. • For one other insecticide the results depended on the reference model used. • Interactive effects between insecticides and Microcystis cannot be generalized. • The concentration addition model provides conservative estimates of mixture effects. - Interactive effects between insecticides and cyanobacterial stressors cannot be generalized, not even for insecticides with closely related known modes of action

  6. Thermodynamics Properties of Binary Gas Mixtures for Brayton Space Nuclear Power System

    International Nuclear Information System (INIS)

    You Ersheng; Shi Lei; Zhang Zuoyi

    2014-01-01

    Space nuclear power system with closed Brayton cycle has the potential advantages of high cycle efficiency. It can be achieved to limit the specific mass of the system with a competitive design scheme, so as to strengthen the advantage of the nuclear energy applying in space propulsion and electric generating compared to solar or chemical propellant. Whereby, the thermodynamic properties of working fluids have a significant influence on the performance of the plant. Therefore, two binary mixtures helium-nitrogen and helium-carbon dioxide are introduced to analysis the variation in the transport and heat transfer capacity of working fluids. Based on the parameters of pure gases, the heat transfer coefficient, pressure losses and aerodynamic loading are calculated as a function of mole fraction at the temperature of 400 K and 1200 K, as well as the typical operating pressure of 2 MPa. Results indicated that the mixture of helium-carbon dioxide with a mole fraction of 0.4 is a more attractive choice for the high heat transfer coefficient, low aerodynamic loading and acceptable pressure losses in contrast to helium-nitrogen and other mixing ratios of helium-carbon dioxide. Its heat transfer coefficient is almost 20% more than that of pure helium and the normalized aerodynamic loading is less than 34% at 1200 K. However; the pressure losses are a little higher with ~3.5 times those of pure helium. (author)

  7. Phase Diagram of Kob-Andersen-Type Binary Lennard-Jones Mixtures

    Science.gov (United States)

    Pedersen, Ulf R.; Schrøder, Thomas B.; Dyre, Jeppe C.

    2018-04-01

    The binary Kob-Andersen (KA) Lennard-Jones mixture is the standard model for computational studies of viscous liquids and the glass transition. For very long simulations, the viscous KA system crystallizes, however, by phase separating into a pure A particle phase forming a fcc crystal. We present the thermodynamic phase diagram for KA-type mixtures consisting of up to 50% small (B ) particles showing, in particular, that the melting temperature of the standard KA system at liquid density 1.2 is 1.028(3) in A particle Lennard-Jones units. At large B particle concentrations, the system crystallizes into the CsCl crystal structure. The eutectic corresponding to the fcc and CsCl structures is cutoff in a narrow interval of B particle concentrations around 26% at which the bipyramidal orthorhombic PuBr3 structure is the thermodynamically stable phase. The melting temperature's variation with B particle concentration at two constant pressures, as well as at the constant density 1.2, is estimated from simulations at pressure 10.19 using isomorph theory. Our data demonstrate approximate identity between the melting temperature and the onset temperature below which viscous dynamics appears. Finally, the nature of the solid-liquid interface is briefly discussed.

  8. Doubled heterogeneous crystal nucleation in sediments of hard sphere binary-mass mixtures.

    Science.gov (United States)

    Löwen, Hartmut; Allahyarov, Elshad

    2011-10-07

    Crystallization during the sedimentation process of a binary colloidal hard spheres mixture is explored by Brownian dynamics computer simulations. The two species are different in buoyant mass but have the same interaction diameter. Starting from a completely mixed system in a finite container, gravity is suddenly turned on, and the crystallization process in the sample is monitored. If the Peclet numbers of the two species are both not too large, crystalline layers are formed at the bottom of the cell. The composition of lighter particles in the sedimented crystal is non-monotonic in the altitude: it is first increasing, then decreasing, and then increasing again. If one Peclet number is large and the other is small, we observe the occurrence of a doubled heterogeneous crystal nucleation process. First, crystalline layers are formed at the bottom container wall which are separated from an amorphous sediment. At the amorphous-fluid interface, a secondary crystal nucleation of layers is identified. This doubled heterogeneous nucleation can be verified in real-space experiments on colloidal mixtures. © 2011 American Institute of Physics

  9. Poisson-Box Sampling algorithms for three-dimensional Markov binary mixtures

    Science.gov (United States)

    Larmier, Coline; Zoia, Andrea; Malvagi, Fausto; Dumonteil, Eric; Mazzolo, Alain

    2018-02-01

    Particle transport in Markov mixtures can be addressed by the so-called Chord Length Sampling (CLS) methods, a family of Monte Carlo algorithms taking into account the effects of stochastic media on particle propagation by generating on-the-fly the material interfaces crossed by the random walkers during their trajectories. Such methods enable a significant reduction of computational resources as opposed to reference solutions obtained by solving the Boltzmann equation for a large number of realizations of random media. CLS solutions, which neglect correlations induced by the spatial disorder, are faster albeit approximate, and might thus show discrepancies with respect to reference solutions. In this work we propose a new family of algorithms (called 'Poisson Box Sampling', PBS) aimed at improving the accuracy of the CLS approach for transport in d-dimensional binary Markov mixtures. In order to probe the features of PBS methods, we will focus on three-dimensional Markov media and revisit the benchmark problem originally proposed by Adams, Larsen and Pomraning [1] and extended by Brantley [2]: for these configurations we will compare reference solutions, standard CLS solutions and the new PBS solutions for scalar particle flux, transmission and reflection coefficients. PBS will be shown to perform better than CLS at the expense of a reasonable increase in computational time.

  10. Evaluation of Thermodynamic Models for Predicting Phase Equilibria of CO2 + Impurity Binary Mixture

    Science.gov (United States)

    Shin, Byeong Soo; Rho, Won Gu; You, Seong-Sik; Kang, Jeong Won; Lee, Chul Soo

    2018-03-01

    For the design and operation of CO2 capture and storage (CCS) processes, equation of state (EoS) models are used for phase equilibrium calculations. Reliability of an EoS model plays a crucial role, and many variations of EoS models have been reported and continue to be published. The prediction of phase equilibria for CO2 mixtures containing SO2, N2, NO, H2, O2, CH4, H2S, Ar, and H2O is important for CO2 transportation because the captured gas normally contains small amounts of impurities even though it is purified in advance. For the design of pipelines in deep sea or arctic conditions, flow assurance and safety are considered priority issues, and highly reliable calculations are required. In this work, predictive Soave-Redlich-Kwong, cubic plus association, Groupe Européen de Recherches Gazières (GERG-2008), perturbed-chain statistical associating fluid theory, and non-random lattice fluids hydrogen bond EoS models were compared regarding performance in calculating phase equilibria of CO2-impurity binary mixtures and with the collected literature data. No single EoS could cover the entire range of systems considered in this study. Weaknesses and strong points of each EoS model were analyzed, and recommendations are given as guidelines for safe design and operation of CCS processes.

  11. Solubility of Stevioside and Rebaudioside A in water, ethanol and their binary mixtures

    Directory of Open Access Journals (Sweden)

    Liliana S. Celaya

    2016-10-01

    Full Text Available In order to investigate the solubility of Stevioside and Rebaudioside A in different solvents (ethanol, water, ethanol:water 30:70 and ethanol:water 70:30, supersaturated solutions of pre-crystalized steviol glycosides were maintained at different temperatures (from 5 °C to 50 °C to reach equilibrium. Under these conditions significant differences were found in the extent of solubility. Rebaudioside A was poorly soluble in ethanol and water, and Stevioside was poorly soluble in water. Solvent mixtures more effectively promoted solubilisation, and a significant effect of temperature on solubility was observed. The two steviol glycosides showed higher solubilities and this behavior was promoted by the presence of the other sweetener. The polarity indices of the solvents were determined, and helped to explain the observed behavior. Several solute-solvent and solute-solute interactions can occur, along with the incidence of a strong affinity between solvents. The obtained results are in accordance with technological applications of ethanol, water and their binary mixtures for Stevioside and Rebaudioside A separations.

  12. Long-term effects of a binary mixture of perfluorooctane sulfonate (PFOS) and bisphenol A (BPA) in zebrafish (Danio rerio)

    DEFF Research Database (Denmark)

    Keiter, Susanne; Baumann, Lisa; Farber, H

    2012-01-01

    aimed at evaluating the long-term effects and toxicity-increasing behavior of PFOS in vivo using the zebrafish (Danio rerio). Fish were maintained in flow-through conditions and exposed to single and binary mixtures of PFOS and the endocrine disruptor bisphenol A (BPA) at nominal concentrations of 0...

  13. Fumigant activity of eleven essential oil compounds and their selected binary mixtures against Culex pipiens pallens (Diptera: Culicidae).

    Science.gov (United States)

    Ma, Wei-Bin; Feng, Jun-Tao; Jiang, Zhi-Li; Wu, Hua; Ma, Zhi-Qing; Zhang, Xing

    2014-10-01

    To seek natural products for the development of environment friendly mosquito control agents, fumigant activity of eleven essential oil compounds and the joint action of the active compounds were evaluated against Culex pipiens pallens adults. Fumigant bioassay demonstrated that carvacrol exhibited the highest fumigant activity followed by thymol and l-perillaldehyde, with LC50 values of 0.26, 0.28, and 0.34 mg/L air, respectively. Among the binary mixtures of four compounds with preferable performance, only the binary mixture of carvacrol and thymol (1:1, w/w) displayed a synergistic effect with the co-toxicity coefficient (CTC) value of 174.1 and LC50 value of 0.16 mg/L air. Furthermore, the actual efficacy of the binary mixture at 300 mg/mat (KT50 = 7.9, 15.8, and 22.0 min after 0, 2, and 4 h of preliminary heating, respectively) was comparable with that of d-allethrin at 30 mg/mat (KT50 = 8.7, 17.9, and 21.2 min after 0, 2, and 4 h of preliminary heating, respectively) tested in vaporizing mats by the glass chamber method (70 × 70 × 70 cm). These results revealed that carvacrol, thymol, and their binary mixture have potential for the development of natural fumigants for adult mosquito control.

  14. An Exercise on Calibration: DRIFTS Study of Binary Mixtures of Calcite and Dolomite with Partially Overlapping Spectral Features

    Science.gov (United States)

    De Lorenzi Pezzolo, Alessandra

    2013-01-01

    Unlike most spectroscopic calibrations that are based on the study of well-separated features ascribable to the different components, this laboratory experience is especially designed to exploit spectral features that are nearly overlapping. The investigated system consists of a binary mixture of two commonly occurring minerals, calcite and…

  15. Global phase equilibrium calculations: Critical lines, critical end points and liquid-liquid-vapour equilibrium in binary mixtures

    DEFF Research Database (Denmark)

    Cismondi, Martin; Michelsen, Michael Locht

    2007-01-01

    A general strategy for global phase equilibrium calculations (GPEC) in binary mixtures is presented in this work along with specific methods for calculation of the different parts involved. A Newton procedure using composition, temperature and Volume as independent variables is used for calculati...

  16. Novel Spectrophotometric Methods for Determination of Salicylamide and Ascorbic acid in their binary mixture

    International Nuclear Information System (INIS)

    Ali, N.W.; Zaazaa, H.E.S.; Abdelrahman, M.M.

    2014-01-01

    Simple, selective and precise four spectrophotometric methods were developed and validated for quantitative determination of Salicylamide (SAD) and Ascorbic acid (ASC, Vitamin C) in their binary mixture. Method A is Area under curve spectrophotometry, in which the area under curve in the wavelength ranges 225-245 nm and 265-285 nm were selected for determination of SAD and ASC. Method B is based on dual wavelength spectrophotometry, where ASC can be determined by difference in absorbance at 249.8 and 285.8 nm. On the same way; SAD is measured by difference in absorbance at 240.4 and 286.4 nm. Method C utilizes isoabsorptive point spectrophotometry where total concentration of SAD and ASC was calculated at their isoabsorptive points at 246.4 and 287 nm, while SAD concentration alone can be determined by first derivative spectrophotometry (1D) at 315.4 nm, then ASC concentration can be determined by subtraction. Method D is ratio subtraction spectrophotometry, where ASC can be determined by dividing the spectrum of the mixture by the spectrum of the SAD (as a divisor) followed by subtracting the constant absorbance value of the plateau region, then finally multiplying the obtained spectrum by the spectrum of the divisor. The developed methods have been successfully applied for determination of the studied drugs in different laboratory prepared mixtures and in their pharmaceutical formulation. Statistical comparison between the results obtained by applying the proposed methods and the reported HPLC method was done, and it was found that there was no significant difference between them regarding both accuracy and precision. (author)

  17. Archimedean (4,8)-tessellation of haeckelite ultrathin nanosheets composed of boron and aluminum-group V binary materials.

    Science.gov (United States)

    Brown, Paul A; Shuford, Kevin L

    2016-11-24

    A compendium of unique haeckelite boron and aluminum-group V binary materials have been assessed for their fundamental thermodynamic and ground state electronic properties within density functional theory. We explore their thermodynamic stability relative to new bulk haeckelite crystal structures and find a number of stable polymorphs of planar and buckled ultrathin nanosheets. The bulk boron and aluminum haeckelite crystals display semiconducting and metallic behavior. From the dispersion curves, we predict the formation of both indirect and direct bandgap crystals. We also discover the existence of a five-coordinate aluminum antimonide crystal hitherto never before observed. Moreover, it is found that a number of the Archimedean four and eight membered ring tessellation planar nanosheets could form should synthesis be attempted. It is predicted that these nanosheets can attain two configurations - planar and buckled. From this work we find that combinations of elements such as boron and nitrogen or phosphorus, and aluminum and nitrogen will likely become true single-atom thick nanosheets. These materials show intrinsic indirect bandgap character, which spans the ultraviolet, visible, and infrared spectrum. In the boron series of these materials, the planar structures show double extrema in the bandstructures with van Hove singularities in the projected density of states at the Fermi energy suggesting strong light-matter interactions. The aluminum series we observe strong charge transfer and larger indirect bandgap nanosheets. This study serves as a starting point for a new class of inorganic bulk and ultrathin film materials, which can have many varied applications in nanotechnology.

  18. Critical size dependence of domain formation observed in coarse-grained simulations of bilayers composed of ternary lipid mixtures.

    Science.gov (United States)

    Pantelopulos, George A; Nagai, Tetsuro; Bandara, Asanga; Panahi, Afra; Straub, John E

    2017-09-07

    Model cellular membranes are known to form micro- and macroscale lipid domains dependent on molecular composition. The formation of macroscopic lipid domains by lipid mixtures has been the subject of many simulation investigations. We present a critical study of system size impact on lipid domain phase separation into liquid-ordered and liquid-disordered macroscale domains in ternary lipid mixtures. In the popular di-C16:0 PC:di-C18:2 PC:cholesterol at 35:35:30 ratio mixture, we find systems with a minimum of 1480 lipids to be necessary for the formation of macroscopic phase separated domains and systems of 10 000 lipids to achieve structurally converged conformations similar to the thermodynamic limit. To understand these results and predict the behavior of any mixture forming two phases, we develop and investigate an analytical Flory-Huggins model which is recursively validated using simulation and experimental data. We find that micro- and macroscale domains can coexist in ternary mixtures. Additionally, we analyze the distributions of specific lipid-lipid interactions in each phase, characterizing domain structures proposed based on past experimental studies. These findings offer guidance in selecting appropriate system sizes for the study of phase separations and provide new insights into the nature of domain structure for a popular ternary lipid mixture.

  19. Critical size dependence of domain formation observed in coarse-grained simulations of bilayers composed of ternary lipid mixtures

    Science.gov (United States)

    Pantelopulos, George A.; Nagai, Tetsuro; Bandara, Asanga; Panahi, Afra; Straub, John E.

    2017-09-01

    Model cellular membranes are known to form micro- and macroscale lipid domains dependent on molecular composition. The formation of macroscopic lipid domains by lipid mixtures has been the subject of many simulation investigations. We present a critical study of system size impact on lipid domain phase separation into liquid-ordered and liquid-disordered macroscale domains in ternary lipid mixtures. In the popular di-C16:0 PC:di-C18:2 PC:cholesterol at 35:35:30 ratio mixture, we find systems with a minimum of 1480 lipids to be necessary for the formation of macroscopic phase separated domains and systems of 10 000 lipids to achieve structurally converged conformations similar to the thermodynamic limit. To understand these results and predict the behavior of any mixture forming two phases, we develop and investigate an analytical Flory-Huggins model which is recursively validated using simulation and experimental data. We find that micro- and macroscale domains can coexist in ternary mixtures. Additionally, we analyze the distributions of specific lipid-lipid interactions in each phase, characterizing domain structures proposed based on past experimental studies. These findings offer guidance in selecting appropriate system sizes for the study of phase separations and provide new insights into the nature of domain structure for a popular ternary lipid mixture.

  20. Densities and viscosities of binary and ternary mixtures of cyclohexanone, 1,4-dioxane and isooctane from T = (288.15 to 313.15) K

    International Nuclear Information System (INIS)

    Rafiee, Hamid Reza; Ranjbar, Shahram; Poursalman, Fariborz

    2012-01-01

    Graphical abstract: For binary and ternary mixtures of the following liquids the densities and viscosities have been determined at several temperatures and over the entire range of composition. Also the Δη and excess molar volumes for binary mixtures determined and have been fitted to the Redlich–Kister equation. The interaction parameters, G 12 in the Grunberg–Nissan equation have been found to be negative for all binary mixtures which indicates decreasing the interaction between unlike molecules. Highlights: ► Experimental data for viscosity and density of binary and ternary mixtures reported. ► The considered solvents are Cyclohexanone, 1,4-Dioxane and Isooctane. ► Temperature ranges from 288.15 to 313.15 K and entire range of composition is considered. ► G 12 , in Grunberg–Nissan equation was negative in all binary mixtures at all temperatures. ► V E and Δη for binary mixtures have been fitted to Redlich–Kister equation. - Abstract: Densities and viscosities of binary and ternary mixtures of cyclohexanone, 1,4-dioxane and isooctane have been measured at temperatures from 288.15 K to 313.15 K and over the entire composition range, under atmospheric pressure. From these binary data, the excess molar volumes have been determined and then fitted to Redlich–Kister equation to determine the appropriate coefficients. This work also provides a test of the Grunberg and Nissan equation for correlation the dynamic viscosities of binary mixtures with mole fractions. The interaction parameters for this equation, G 12 were negative for all binary mixtures at different temperatures over entire range of composition which attributed to decreasing the strength of interaction between unlike molecules in mixture.

  1. Interaction patterns and toxicities of binary and ternary pesticide mixtures to Daphnia magna estimated by an accelerated failure time model.

    Science.gov (United States)

    Qiu, Xuchun; Tanoue, Wataru; Kawaguchi, Atsushi; Yanagawa, Takashi; Seki, Masanori; Shimasaki, Yohei; Honjo, Tsuneo; Oshima, Yuji

    2017-12-31

    Organisms in natural environments are often exposed to a broad variety of chemicals, and the multi-chemical mixtures exposure may produce significant toxic effects, even though the individual chemicals are present at concentrations below their no-observed-effect concentrations. This study represents the first attempt that uses the accelerated failure time (AFT) model to quantify the interaction and toxicity of multi-chemical mixtures in environmental toxicology. We firstly conducted the acute immobilization tests with Daphnia magna exposed to mixtures of diazinon (DZN), fenitrothion (MEP); and thiobencarb (TB) in single, binary, and ternary formulations, and then fitted the results to the AFT model. The 48-h EC 50 (concentration required to immobilize 50% of the daphnids at 48h) values for each pesticide obtained from the AFT model are within a factor of 2 of the corresponding values calculated from the single pesticide exposure tests, indicating the methodology is able to provide credible toxicity values. The AFT model revealed either significant synergistic (DZN and MEP; DZN and TB) or antagonistic (MEP and TB) interactions in binary mixtures, while the interaction pattern of ternary mixture depended on both the concentration levels and concentration ratios of pesticides. With a factor of 2, the AFT model accurately estimated the toxicities for 78% of binary mixture formulations that exhibited significant synergistic effects, and the toxicities for all the ternary formulations. Our results showed that the AFT model can provide a simple and efficient way to quantify the interactions between pesticides and to assess the toxicity of their mixtures. This ability may greatly facilitate the ecotoxicological risk assessment of exposure to multi-chemical mixtures. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Physiological response of the nematode Caenorhabditis elegans exposed to binary mixture of uranium and cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Margerit, A.; Gilbin, R. [French Institute for Radiological Protection and Nuclear Safety - IRSN (France); Gomez, E. [Universite Montpellier 1 (France)

    2014-07-01

    Both uranium (U) and cadmium (Cd) are natural ubiquitous substances whose occurrence may be magnified in the vicinity of some Nuclear Fuel Cycle Facility (NFCF) (e.g. uranium mining area) or intensive farming areas. Natural U is a mainly chemo-toxic radioelement, with a slight radio-toxic activity, while Cd is a fully chemo-toxic trace metal. Due to their possible co-occurrence, the study of their combined effects on ecosystems may be of interest in a risk assessment perspective. MixTox tool is a simple descriptive model commonly used to study the effects of chemical mixtures. It relies on dose response, concentration addition and response addition concepts to describe combined toxicant effects and identify possible Synergistic/Antagonistic - Constant/Dose-level/Dose ratio dependent - interactions. In the present study, toxicity of binary mixture of U and Cd was assessed on physiological parameters, maximal length and brood size, in the soil nematode Caenorhabditis elegans. A 49 condition fractional factorial design was used with U and Cd concentrations ranging from 0.95 to 1.3 mM and 0.006 to 0.04 mM, respectively. Dose response curves obtained for U and Cd on maximal length and brood size were consistent with published data. Using MixTox tool, the best description of these endpoints was met with the response addition concept and the dose-ratio dependent interaction model. A significant antagonism was identified when Cd toxicity is preponderant in the mixture and was confirmed with experimental observations. On the other hand, no significant interaction could be identified when U toxicity was preponderant in the mixture. Interaction between the two chemicals may occur during the exposure, the toxicokinetics and/or during the toxico-dynamic phases. Based on the results of this study, a probable hypothesis would be that U, whose toxicity is in the mM range, reduces bioaccumulation of Cd, whose toxicity is in the range of 10 μM. A bioaccumulation assay of U and Cd

  3. Soot modeling of counterflow diffusion flames of ethylene-based binary mixture fuels

    KAUST Repository

    Wang, Yu

    2015-03-01

    A soot model was developed based on the recently proposed PAH growth mechanism for C1-C4 gaseous fuels (KAUST PAH Mechanism 2, KM2) that included molecular growth up to coronene (A7) to simulate soot formation in counterflow diffusion flames of ethylene and its binary mixtures with methane, ethane and propane based on the method of moments. The soot model has 36 soot nucleation reactions from 8 PAH molecules including pyrene and larger PAHs. Soot surface growth reactions were based on a modified hydrogen-abstraction-acetylene-addition (HACA) mechanism in which CH3, C3H3 and C2H radicals were included in the hydrogen abstraction reactions in addition to H atoms. PAH condensation on soot particles was also considered. The experimentally measured profiles of soot volume fraction, number density, and particle size were well captured by the model for the baseline case of ethylene along with the cases involving mixtures of fuels. The simulation results, which were in qualitative agreement with the experimental data in the effects of binary fuel mixing on the sooting structures of the measured flames, showed in particular that 5% addition of propane (ethane) led to an increase in the soot volume fraction of the ethylene flame by 32% (6%), despite the fact that propane and ethane are less sooting fuels than is ethylene, which is in reasonable agreement with experiments of 37% (14%). The model revealed that with 5% addition of methane, there was an increase of 6% in the soot volume fraction. The average soot particle sizes were only minimally influenced while the soot number densities were increased by the fuel mixing. Further analysis of the numerical data indicated that the chemical cross-linking effect between ethylene and the dopant fuels resulted in an increase in PAH formation, which led to higher soot nucleation rates and therefore higher soot number densities. On the other hand, the rates of soot surface growth per unit surface area through the HACA mechanism were

  4. Four Spectrophotometric Methods For Simultaneous Determination Of Carbamazepine And Lamotrigine In Binary Mixtures And Urine Samples

    International Nuclear Information System (INIS)

    Najib, F.M.; Mustafa, M.S.

    2014-01-01

    In this work four different UV-spectrophotometric methods are described for simultaneous determination of antiepileptic drugs; carbamazepine (CBZ) and lamotrigine (LMT) in binary synthetic mixtures and urine samples without separation. First method was by solving the two simultaneous equations (SEQ) based on total absorbance according to Beers law. Second was Dual wavelength (DWSP) method; Absorbance difference between 304 and 313 nm was measurable for CBZ but was zero for LMT. Likewise the absorbance difference between 282 and 290 nm was significant for LMT, and zero for CBZ. Third involved the use of zero- crossing first derivative method (ZCDSP) using the amplitudes at 308.9 and 286.6 nm for CBZ and LMT respectively. Ratio Derivative Spectrophotometry (RDSP) was the last. Here, the absorbance at different concentrations of CBZ or LMT, was divided, wavelength by wavelength, by the absorbance of a divisor, which was LMT standard for the analyte CBZ, and vice versa for LMT, (Divisor=2.0 μg.mL -1 ) in both cases. The amplitude of the derivative ratio spectra at 290 nm with wavelength interval (Δλ=6.0nm) and 328 nm (Δλ=4.0 nm) were selected for the determination of CBZ and LMT respectively. CBZ and LMT were simultaneously determined in synthetic mixtures and urine samples by the four methods giving good linearity, r 2 ranged between 0.9990 - 0.9997. Detection Limit (D.L) was mostly less than 0.4 μg.mL -1 ,while in case of ZCDSP and RDSP were between 0.01-0.2 μg.mL -1 with wider linearity range (1-50 for CBZ and 1 - 80 μg.mL -1 for LMT). A slightly lower sensitivity was observed when suppressing solution for urine analysis was used to remove interferences. The recoveries of CBZ and LMT in samples of urine of a healthy person spiked with the drugs and using urine of a healthy person as a blank were, in most cases, around (101.0 % - 103.33 %) and (98.33 % - 102.16 %) with RSD≤3.61 and 3.63 % for CBZ and LMT respectively. The recoveries using suppressing

  5. Capillary-wave dynamics and interface structure modulation in binary Bose-Einstein condensate mixtures

    Science.gov (United States)

    Indekeu, Joseph O.; Van Thu, Nguyen; Lin, Chang-You; Phat, Tran Huu

    2018-04-01

    The localized low-energy interfacial excitations, or interfacial Nambu-Goldstone modes, of phase-segregated binary mixtures of Bose-Einstein condensates are investigated analytically. To this end a double-parabola approximation (DPA) is performed on the Lagrangian density in Gross-Pitaevskii theory for a system in a uniform potential. This DPA entails a model in which analytic expressions are obtained for the excitations underlying capillary waves or ripplons for arbitrary strength K (>1 ) of the phase segregation. The dispersion relation ω (k ) ∝k3 /2 is derived directly from the Bogoliubov-de Gennes equations in the limit that the wavelength 2 π /k is much larger than the interface width. The proportionality constant in the dispersion relation provides the static interfacial tension. A correction term in ω (k ) of order k5 /2 is calculated analytically within the DPA model. The combined result is tested against numerical diagonalization of the exact Bogoliubov-de Gennes equations. Satisfactory agreement is obtained in the range of physically relevant wavelengths. The ripplon dispersion relation is relevant to state-of-the-art experiments using (quasi)uniform optical-box traps. Furthermore, within the DPA model explicit expressions are obtained for the structural deformation of the interface due to the passing of the capillary wave. It is found that the amplitude of the wave is enhanced by an amount that is quadratic in the ratio of the phase velocity ω /k to the sound velocity c . For generic mixtures consisting of condensates with unequal healing lengths, an additional modulation is predicted of the common value of the condensate densities at the interface.

  6. An experimental approach aiming the production of a gas mixture composed of hydrogen and methane from biomass as natural gas substitute in industrial applications.

    Science.gov (United States)

    Kraussler, Michael; Schindler, Philipp; Hofbauer, Hermann

    2017-08-01

    This work presents an experimental approach aiming the production of a gas mixture composed of H 2 and CH 4 , which should serve as natural gas substitute in industrial applications. Therefore, a lab-scale process chain employing a water gas shift unit, scrubbing units, and a pressure swing adsorption unit was operated with tar-rich product gas extracted from a commercial dual fluidized bed biomass steam gasification plant. A gas mixture with a volumetric fraction of about 80% H 2 and 19% CH 4 and with minor fractions of CO and CO 2 was produced by employing carbon molecular sieve as adsorbent. Moreover, the produced gas mixture had a lower heating value of about 15.5MJ·m -3 and a lower Wobbe index of about 43.4MJ·m -3 , which is similar to the typical Wobbe index of natural gas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Study on the Interaction Coefficients in PR Equation with vdW Mixing Rules for HFC and HC Binary Mixtures

    Science.gov (United States)

    Chen, Jian-Xin; Hu, Peng; Chen, Ze-Shao

    2008-12-01

    The Peng-Robinson equation of state with the van der Waals mixing rules was used to correlate vapor-liquid equilibrium (VLE) data for HFC/HC, HFC/HFC, and HC/HC binary mixtures. The interaction parameter k ij was obtained for every binary mixture. It was assumed that k ij has contributions from the two components, and each component has its own constant contribution factor k i for the mixture, and the values of k ij indicate the degree in difference of properties between the two components. Therefore, the interaction parameters k ij is proposed as: k ij = k i - k j . The values of the mixing factor k i for Hydrofluorocarbons (HFCs) and Hydrocarbons (HCs), including propane, isobutane, n-butane, R23, R32, R125, R143a, R134a, R152a, R227ea R236fa, R236ea, and R245fa, were obtained by least-square fitting. In total, 39 refrigerant binary mixtures were analyzed on the basis of this method, and the results showed good agreement with experimental data. The overall average absolute deviations of pressure and vapor mole fraction are 1.3 % and 0.0089, respectively.

  8. Micelle formation of amphiphilic polystyrene-b-poly(N-vinylpyrrolidone) diblock copolymer in methanol and water-methanol binary mixtures.

    Science.gov (United States)

    Hussain, H; Tan, B H; Gudipati, C S; He, C B; Liu, Y; Davis, Thomas P

    2009-05-19

    The micelle formation by the amphiphilic polystyrene-block-poly(N-vinylpyrrolidone) (PS48-b-PNVP99) copolymer is investigated in methanol and water-methanol binary mixtures of various compositions using 1H NMR, fluorescence spectroscopy, static/dynamic light scattering (SLS/DLS), and transmission electron microscopy (TEM). Critical micelle concentrations (cmc) are determined by employing fluorescence spectroscopy and DLS measurements. The cmc of the PS48-b-PNVP99 block copolymer increases with increasing methanol content in the water-methanol binary mixtures, suggesting that methanol is a better solvent for the PS48-b-PNVP99 block copolymer than water-methanol mixtures or pure water. The amphiphilic PS48-b-PNVP99 diblock copolymer forms spherical micelles of Rh approximately 16 nm in pure methanol solution as revealed by DLS measurements. In contrast, significantly larger micelles having higher aggregation numbers are formed in water-methanol binary mixtures. Temperature dependent data reveal an increase in aggregation number and radius of gyration (Rg) concomitantly with temperature (10-40 degrees C). In contrast, the overall size (Rh) of the micelles remains almost constant over the same temperature range. An explanation is tendered that PNVP coronas dehydrate/desolvate at higher temperatures counteracting the increase in micelle size (Rh) caused by increased aggregation numbers (Nagg).

  9. Densities and derived thermodynamic properties of binary (alkanol + boldine) mixtures in the compressed liquid region

    International Nuclear Information System (INIS)

    Durán-Zenteno, Moisés S.; Pérez-López, Hugo I.; Galicia-Luna, Luis A.; Elizalde-Solis, Octavio

    2012-01-01

    Highlights: ► We measured densities for {alkanol (ethanol or 1-propanol) + boldine} mixtures. ► Liquid densities are reported in the ranges of (1 to 20) MPa and (313 to 363) K. ► Thermodynamic derived properties were calculated using an empirical correlation. ► Extrapolated densities at atmospheric pressure agree with the literature data. - Abstract: In this work, densities of two binary systems of {alkanol (ethanol and 1-propanol) + boldine} are measured at temperatures from (313 to 363) K and pressures up to 20 MPa using an Anton Paar vibrating tube densimeter. Each (alkanol + boldine) system was prepared at five diluted compositions with respect to the alkaloid. These are (x 2 = 0.0012, 0.0074, 0.0136, 0.0196, 0.0267) and (x 2 = 0.0018, 0.0046, 0.0077, 0.0112, 0.0142) mixed in ethanol and 1-propanol, respectively. Experimental densities are correlated using an empirical 6-parameter equation with deviations within 0.04%. Extrapolated densities at atmospheric pressure agree with the literature data. Isobaric expansivity, isothermal compressibility, thermal pressure coefficient, and internal pressure have been calculated.

  10. Thermal Diffusion in Binary Mixtures: Transient Behavior and Transport Coefficients from Equilibrium and Nonequilibrium Molecular Dynamics.

    Science.gov (United States)

    Bonella, Sara; Ferrario, Mauro; Ciccotti, Giovanni

    2017-10-24

    Equilibrium and nonequilibrium molecular dynamics simulations are combined to compute the full set of coefficients that appear in the phenomenological equations describing thermal transport in a binary mixture subject to a constant thermal gradient. The Dynamical Non-Equilibrium Molecular Dynamics approach (D-NEMD) is employed to obtain the microscopic time evolution of the density and temperature fields, together with that of the mass and energy fluxes. D-NEMD enables one to study not only the steady state, but also the evolution of the fields during the transient that follows the onset of the thermal gradient, up to the establishment of the steady state. This makes it possible to ensure that the system has indeed reached a stationary condition, and to analyze the transient mechanisms and time scales of the mass and energy transport. A local time averaging procedure is applied to each trajectory contributing to the calculation to improve the signal-to-noise ratio in the estimation of the fluxes and to obtain a clear signal with the, relatively limited, statistics available.

  11. Ecotoxicity of binary mixtures of Microcystis aeruginosa and insecticides to Daphnia pulex.

    Science.gov (United States)

    Asselman, J; Janssen, C R; Smagghe, G; De Schamphelaere, K A C

    2014-05-01

    In aquatic ecosystems, mixtures of chemical and natural stressors can occur which may significantly complicate risk assessment approaches. Here, we show that effects of binary combinations of four different insecticides and Microcystis aeruginosa, a toxic cyanobacteria, on Daphnia pulex exhibited distinct interaction patterns. Combinations with chlorpyrifos and tetradifon caused non-interactive effects, tebufenpyrad caused an antagonistic interaction and fenoyxcarb yielded patterns that depended on the reference model used (i.e. synergistic with independent action, additive with concentration addition). Our results demonstrate that interactive effects cannot be generalised across different insecticides, not even for those targeting the same biological pathway (i.e. tebufenpyrad and tetradifon both target oxidative phosphorylation). Also, the concentration addition reference model provided conservative predictions of effects in all investigated combinations for risk assessment. These predictions could, in absence of a full mechanistic understanding, provide a meaningful solution for managing water quality in systems impacted by both insecticides and cyanobacterial blooms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Microwave dielectric relaxation spectroscopy study of propylene glycol/ethanol binary mixtures: Temperature dependence

    Science.gov (United States)

    Vishwam, T.; Shihab, Suriya; Murthy, V. R. K.; Tiong, Ha Sie; Sreehari Sastry, S.

    2017-05-01

    Complex dielectric permittivity measurements of propylene glycol (PG) in ethanol at various mole fractions were measured by using open-ended coaxial probe technique at different temperatures in the frequency range 0.02 propylene glycol and ethanol and their binary system have been evaluated theoretically at gaseous state as well as alcoholic medium by using PCM and IEFPCM solvation models from the Hatree-Fock (HF) and Density Functional Theory (DFT-B3LYP) methods with 6-311G* and 6-311G** basis sets. The obtained results have been interpreted in terms of the short and long range ordering of the dipoles, Kirkwood correlation factor (geff), thermodynamic parameters, mean molecular polarizability (αM) and interaction in the mixture through hydrogen bonding. Dielectric relaxation study of propylene glycol in ethanol medium Determination of excess dielectric and thermodynamic parameters Comparison of experimental dipole moment with theoretical calculations Interpretation of the molecular interactions in the liquid through H-bonding Correlation between the evaluated dielectric parameters and theoretical results

  13. Novel spectroscopic methods for determination of Cromolyn sodium and Oxymetazoline hydrochloride in binary mixture

    Science.gov (United States)

    Abdel-Aziz, Omar; El-Kosasy, A. M.; Magdy, N.; El Zahar, N. M.

    2014-10-01

    New accurate, sensitive and selective spectrophotometric and spectrofluorimetric methods were developed and subsequently validated for determination of Cromolyn sodium (CS) and Oxymetazoline HCl (OXY) in binary mixture. These methods include ‘H-point standard addition method (HPSAM) and area under the curve (AUC)' spectrophotometric method and first derivative synchronous fluorescence spectroscopic (FDSFS) method. For spectrophotometric methods, absorbances were recorded at 241.5 nm and 274.9 nm for HPSAM and the wavelength was selected in ranges 232.0-254.0 nm and 216.0-229.0 nm for AUC method, where the concentration was obtained by applying Cramer's rule. For FDSFS method, the first-derivative synchronous fluorescence signal was measured at 290.0 nm, using Δλ = 145.0 nm. The suggested methods were validated according to International Conference of Harmonization (ICH) guidelines and the results revealed that they were precise and reproducible. All the obtained results were statistically compared with those of the reported method and there was no significant difference.

  14. Novel spectroscopic methods for determination of Cromolyn sodium and Oxymetazoline hydrochloride in binary mixture.

    Science.gov (United States)

    Abdel-Aziz, Omar; El-Kosasy, A M; Magdy, N; El Zahar, N M

    2014-10-15

    New accurate, sensitive and selective spectrophotometric and spectrofluorimetric methods were developed and subsequently validated for determination of Cromolyn sodium (CS) and Oxymetazoline HCl (OXY) in binary mixture. These methods include 'H-point standard addition method (HPSAM) and area under the curve (AUC)' spectrophotometric method and first derivative synchronous fluorescence spectroscopic (FDSFS) method. For spectrophotometric methods, absorbances were recorded at 241.5nm and 274.9nm for HPSAM and the wavelength was selected in ranges 232.0-254.0nm and 216.0-229.0nm for AUC method, where the concentration was obtained by applying Cramer's rule. For FDSFS method, the first-derivative synchronous fluorescence signal was measured at 290.0nm, using Δλ=145.0nm. The suggested methods were validated according to International Conference of Harmonization (ICH) guidelines and the results revealed that they were precise and reproducible. All the obtained results were statistically compared with those of the reported method and there was no significant difference. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Evaluation of MidIR fibre optic reflectance: detection limit, reproducibility and binary mixture discrimination.

    Science.gov (United States)

    Sessa, Clarimma; Bagán, Héctor; García, José Francisco

    2013-11-01

    algorithm, polynomial baseline offset, Standard Normal Variate algorithm - SNV) to the raw spectra allows improving these results to maximum values of 15%. Finally, the capabilities of PCA and MidIR-FORS to discriminate between binary mixtures were tested. The results demonstrate that it is possible to differentiate mixtures depending on the range of concentration of their components, within specific limits of detection. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Evaluation of MidIR fibre optic reflectance: Detection limit, reproducibility and binary mixture discrimination

    Science.gov (United States)

    Sessa, Clarimma; Bagán, Héctor; García, José Francisco

    2013-11-01

    algorithm, polynomial baseline offset, Standard Normal Variate algorithm - SNV) to the raw spectra allows improving these results to maximum values of 15%. Finally, the capabilities of PCA and MidIR-FORS to discriminate between binary mixtures were tested. The results demonstrate that it is possible to differentiate mixtures depending on the range of concentration of their components, within specific limits of detection.

  17. Ebulliometric determination and prediction of (vapor + liquid) equilibria for binary and ternary mixtures containing alcohols (C{sub 1}-C{sub 4}) and dimethyl carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroyuki, E-mail: matsuda@chem.cst.nihon-u.ac.jp [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Fukano, Makoto; Kikkawa, Shinichiro [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Constantinescu, Dana [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany); Kurihara, Kiyofumi; Tochigi, Katsumi; Ochi, Kenji [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Gmehling, Juergen [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany)

    2012-01-15

    Highlights: > The VLE behavior of systems containing dimethyl carbonate (DMC) was investigated. > VLE data for ternary and binary mixtures containing alcohol and DMC were measured. > Several activity coefficient models were used for data reduction or prediction. > Valley line, i.e., distillation boundary, was observed for the ternary mixture. > Residue curves were calculated to investigate composition profile for distillation. - Abstract: (Vapor + liquid) equilibrium (VLE) data for a ternary mixture, namely {l_brace}methanol + propan-1-ol + dimethyl carbonate (DMC){r_brace}, and four binary mixtures, namely an {l_brace}alcohol (C{sub 3} or C{sub 4}) + DMC{r_brace}, containing the binary constituent mixtures of the ternary mixture, were measured at p = (40.00 to 93.32) kPa using a modified Swietoslawski-type ebulliometer. The experimental data for the binary systems were correlated using the Wilson model. The Wilson model was also applied to the ternary system to predict the VLE behavior using parameters from the binary mixtures. The modified UNIFAC (Dortmund) model was also tested for the predictions of the VLE behavior of the binary and ternary mixtures. In addition, the experimental VLE data for the ternary and constituent binary mixtures were correlated using the extended Redlich-Kister (ERK) model, which can completely represent the azeotropic points. For the ternary system, a comparison of the experimental and the predicted or correlated boiling points obtained using the Wilson and ERK models showed that the ERK model is more accurate. The valley line, i.e., the curve which divides the patterns of vapor-liquid tie lines, was found in the (methanol + propan-1-ol + DMC) system. This valley line could be represented by the ERK model. Finally, the composition profile for simple distillation of this ternary mixture was obtained by analysis of the residue curves from the estimated Wilson parameters of the constituent binary mixtures.

  18. Ebulliometric determination and prediction of (vapor + liquid) equilibria for binary and ternary mixtures containing alcohols (C1-C4) and dimethyl carbonate

    International Nuclear Information System (INIS)

    Matsuda, Hiroyuki; Fukano, Makoto; Kikkawa, Shinichiro; Constantinescu, Dana; Kurihara, Kiyofumi; Tochigi, Katsumi; Ochi, Kenji; Gmehling, Juergen

    2012-01-01

    Highlights: → The VLE behavior of systems containing dimethyl carbonate (DMC) was investigated. → VLE data for ternary and binary mixtures containing alcohol and DMC were measured. → Several activity coefficient models were used for data reduction or prediction. → Valley line, i.e., distillation boundary, was observed for the ternary mixture. → Residue curves were calculated to investigate composition profile for distillation. - Abstract: (Vapor + liquid) equilibrium (VLE) data for a ternary mixture, namely {methanol + propan-1-ol + dimethyl carbonate (DMC)}, and four binary mixtures, namely an {alcohol (C 3 or C 4 ) + DMC}, containing the binary constituent mixtures of the ternary mixture, were measured at p = (40.00 to 93.32) kPa using a modified Swietoslawski-type ebulliometer. The experimental data for the binary systems were correlated using the Wilson model. The Wilson model was also applied to the ternary system to predict the VLE behavior using parameters from the binary mixtures. The modified UNIFAC (Dortmund) model was also tested for the predictions of the VLE behavior of the binary and ternary mixtures. In addition, the experimental VLE data for the ternary and constituent binary mixtures were correlated using the extended Redlich-Kister (ERK) model, which can completely represent the azeotropic points. For the ternary system, a comparison of the experimental and the predicted or correlated boiling points obtained using the Wilson and ERK models showed that the ERK model is more accurate. The valley line, i.e., the curve which divides the patterns of vapor-liquid tie lines, was found in the (methanol + propan-1-ol + DMC) system. This valley line could be represented by the ERK model. Finally, the composition profile for simple distillation of this ternary mixture was obtained by analysis of the residue curves from the estimated Wilson parameters of the constituent binary mixtures.

  19. Thermodynamic properties of fluid mixtures at high pressures and high temperatures. Application to high explosives and to phase diagrams of binary mixtures

    International Nuclear Information System (INIS)

    Pittion-Rossillon, Gerard

    1982-01-01

    The free energy for mixtures of about ten species which are chemically reacting is calculated. In order to have accurate results near the freezing line, excess properties are deduced from a modern statistical mechanics theory. Intermolecular potentials for like molecules are fitted to give good agreement with shock experiments in pure liquid samples, and mixture properties come naturally from the theory. The stationary Chapman-Jouguet detonation wave is calculated with a chemical equilibrium computer code and results are in good agreement with experiment for a lot of various explosives. One then study gas-gas equilibria in a binary mixture and show the extreme sensitivity of theoretical phase diagrams to the hypothesis of the model (author) [fr

  20. Efficient capture of SO2 by a binary mixture of caprolactam tetrabutyl ammonium bromide ionic liquid and water.

    Science.gov (United States)

    Duan, Erhong; Guo, Bin; Zhang, Miaomiao; Guan, Yanan; Sun, Hua; Han, Jing

    2011-10-30

    The solubility of SO(2) in a binary mixture of water and caprolactam tetrabutyl ammonium bromide ionic liquid (CPL-TBAB IL) was investigated. Though the ionic liquid and water were fully miscible, a phase separation occurred when SO(2) was introduced into the mixture. The SO(2) concentrated in the lower layer, and it could be released by heating the solution under reduced pressure (382.2K, 10.1 kPa). After desorption, the mixture could be reused to absorb SO(2). It was found that SO(2) acts as a switch to cause the water and CPL-TBAB IL to phase separate, and the mechanics of this phase separation process was studied by gas chromatography-mass spectrometry, fourier transform-infrared spectroscopy and Karl-Fisher titration. The absorption and desorption of SO(2) in the CPL-TBAB/water mixtures were reversible. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Heat capacities and densities of the binary mixtures containing ethanol, cyclohexane or 1-hexene at high pressures

    International Nuclear Information System (INIS)

    Vega-Maza, David; Carmen Martín, M.; Martin Trusler, J.P.; Segovia, José J.

    2013-01-01

    Highlights: ► We report heat capacities of cyclohexane, 1-hexene and the mixtures with ethanol. ► They were measured at five pressures over the range (0 to 20) MPa. ► Excess isobaric heat capacities are calculated and fitted. ► The densities for pure compounds and mixtures are also reported. - Abstract: Heat capacities and densities are significant in the design or the improvement of processes such as the blending of biofuels. An automated flow calorimeter, developed in our group, was used for the accurate measurement of isobaric heat capacities for pure compounds and mixtures over the range (250 to 400) K and (0 to 20) MPa. In this paper, isobaric heat capacities for cyclohexane and 1-hexene and their binary mixtures with ethanol are reported. Also the densities have been measured using an automated densimeter up to 70 MPa.

  2. Optimization of a synthetic mixture composed of major Trichoderma reesei enzymes for the hydrolysis of steam-exploded wheat straw

    Directory of Open Access Journals (Sweden)

    Billard Hélène

    2012-02-01

    Full Text Available Abstract Background An efficient hydrolysis of lignocellulosic substrates to soluble sugars for biofuel production necessitates the interplay and synergistic interaction of multiple enzymes. An optimized enzyme mixture is crucial for reduced cost of the enzymatic hydrolysis step in a bioethanol production process and its composition will depend on the substrate and type of pretreatment used. In the present study, an experimental design was used to determine the optimal composition of a Trichoderma reesei enzyme mixture, comprising the main cellulase and hemicellulase activities, for the hydrolysis of steam-exploded wheat straw. Methods Six enzymes, CBH1 (Cel7a, CBH2 (Cel6a, EG1 (Cel7b, EG2 (Cel5a, as well as the xyloglucanase Cel74a and the xylanase XYN1 (Xyl11a were purified from a T. reesei culture under lactose/xylose-induced conditions. Sugar release was followed in milliliter-scale hydrolysis assays for 48 hours and the influence of the mixture on initial conversion rates and final yields is assessed. Results The developed model could show that both responses were strongly correlated. Model predictions suggest that optimal hydrolysis yields can be obtained over a wide range of CBH1 to CBH2 ratios, but necessitates a high proportion of EG1 (13% to 25% which cannot be replaced by EG2. Whereas 5% to 10% of the latter enzyme and a xylanase content above 6% are required for highest yields, these enzymes are predicted to be less important in the initial stage of hydrolysis. Conclusions The developed model could reliably predict hydrolysis yields of enzyme mixtures in the studied domain and highlighted the importance of the respective enzyme components in both the initial and the final hydrolysis phase of steam-exploded wheat straw.

  3. Optimization of a synthetic mixture composed of major Trichoderma reesei enzymes for the hydrolysis of steam-exploded wheat straw.

    Science.gov (United States)

    Billard, Hélène; Faraj, Abdelaziz; Lopes Ferreira, Nicolas; Menir, Sandra; Heiss-Blanquet, Senta

    2012-02-28

    An efficient hydrolysis of lignocellulosic substrates to soluble sugars for biofuel production necessitates the interplay and synergistic interaction of multiple enzymes. An optimized enzyme mixture is crucial for reduced cost of the enzymatic hydrolysis step in a bioethanol production process and its composition will depend on the substrate and type of pretreatment used. In the present study, an experimental design was used to determine the optimal composition of a Trichoderma reesei enzyme mixture, comprising the main cellulase and hemicellulase activities, for the hydrolysis of steam-exploded wheat straw. Six enzymes, CBH1 (Cel7a), CBH2 (Cel6a), EG1 (Cel7b), EG2 (Cel5a), as well as the xyloglucanase Cel74a and the xylanase XYN1 (Xyl11a) were purified from a T. reesei culture under lactose/xylose-induced conditions. Sugar release was followed in milliliter-scale hydrolysis assays for 48 hours and the influence of the mixture on initial conversion rates and final yields is assessed. The developed model could show that both responses were strongly correlated. Model predictions suggest that optimal hydrolysis yields can be obtained over a wide range of CBH1 to CBH2 ratios, but necessitates a high proportion of EG1 (13% to 25%) which cannot be replaced by EG2. Whereas 5% to 10% of the latter enzyme and a xylanase content above 6% are required for highest yields, these enzymes are predicted to be less important in the initial stage of hydrolysis. The developed model could reliably predict hydrolysis yields of enzyme mixtures in the studied domain and highlighted the importance of the respective enzyme components in both the initial and the final hydrolysis phase of steam-exploded wheat straw.

  4. Experimental and theoretical study of surface tension of binary mixtures of (n-alkyl acetates + heptane, benzene, and toluene)

    International Nuclear Information System (INIS)

    Rafati, Amir Abbas; Ghasemian, Ensieh

    2009-01-01

    Surface properties of binary mixtures of (n-alkyl acetates + heptane, benzene, and toluene) have been measured by surface tension method at T = 298.15 K and atmospheric pressure. Also, the surface tension has been predicted based on the Suarez method. This method combines a model for the description of surface tension of liquid mixtures with a group contribution method for the calculation of activity coefficient. The mean relative standard deviations obtained from the comparison of experimental (measured) and calculated surface tension values for the eight binary systems are less than 1.5%, which leads to concluding that the model shows a good accuracy in different situations in comparison with other predicted equations. In addition, the relative Gibbs adsorption and the surface mole fraction have been evaluated using this model. The surface tension deviations were calculated from experimental results and have been fitted to the Redlich-Kister type polynomial relation

  5. Effect of bond-disorder on the phase-separation kinetics of binary mixtures: A Monte Carlo simulation study

    Science.gov (United States)

    Singh, Awaneesh; Singh, Amrita; Chakraborti, Anirban

    2017-09-01

    We present Monte Carlo (MC) simulation studies of phase separation in binary (AB) mixtures with bond-disorder that is introduced in two different ways: (i) at randomly selected lattice sites and (ii) at regularly selected sites. The Ising model with spin exchange (Kawasaki) dynamics represents the segregation kinetics in conserved binary mixtures. We find that the dynamical scaling changes significantly by varying the number of disordered sites in the case where bond-disorder is introduced at the randomly selected sites. On the other hand, when we introduce the bond-disorder in a regular fashion, the system follows the dynamical scaling for the modest number of disordered sites. For a higher number of disordered sites, the evolution morphology illustrates a lamellar pattern formation. Our MC results are consistent with the Lifshitz-Slyozov power-law growth in all the cases.

  6. Dielectric studies on binary mixtures of Tri-n-butyl phosphate (TBP) and long-chain primary alcohols (modifiers)

    International Nuclear Information System (INIS)

    Dash, S.K.; Swain, B.B.

    1993-01-01

    Dielectric constant (ε) of Tri-n-butyl phosphate (TBP), in binary mixtures with five long-chain primary alcohols viz; 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol has been measured at ν = 455 kHz and at temperature 302 K. The data is used to evaluate mutual correlation factor g ab , excess molar polarization ΔP and excess free energy of mixing ΔF ab by using Winkelmann-Quitzsch eqn. for binary mixtures to assess the suitability of the alcohols as modifiers. The trend of variation of these parameters exhibit marked dependence on chain-length of the alcohols indicating 1-heptanol to be an efficient modifier. (author)

  7. Synergistic toxicity and physiological impact of imidacloprid alone and binary mixtures with seven representative pesticides on honey bee (Apis mellifera)

    OpenAIRE

    Zhu, Yu Cheng; Yao, Jianxiu; Adamczyk, John; Luttrell, Randall

    2017-01-01

    Imidacloprid is the most widely used insecticide in the world. In this study, we used spraying methods to simulate field exposures of bees to formulated imidacloprid (Advise® 2FL) alone and binary mixtures with seven pesticides from different classes. Synergistic toxicity was detected from mixtures of Advise (58.6 mg a.i./L imidacloprid)+Domark (512.5 mg a.i. /L tetraconazole), Advise+Transform (58.5 mg a.i./L sulfoxaflor), and Advise+Vydate (68 mg a.i./L oxamyl), and mortality was significan...

  8. Linear radiation transport in randomly distributed binary mixtures: a one dimensional and exact treatment for the scattering case

    International Nuclear Information System (INIS)

    Vanderhaegen, D.; Deutsch, C.

    1988-01-01

    Scattering effects are considered for radiative transfer within randomly distributed and binary mixtures in one dimension. The most general formalism is developed within the framework of the invariant imbedding method. The length L of the random sample thus appears as a new variable. One transmission coefficient T(L) suffices to specify locally the intensities. By analogy with the homogeneous situation, one introduces an effective opacity with = (1 + σ eff L) -1 fulfilling σ eff ≤ = p 0 σ 0 + p 1 σ 1 (0 and 1 respectively refer to the components involved in the mixture). Equality is reached when L 0, ∞. Otherwise, σ eff experiences a deep transmission window

  9. Continuous Wavelet Transform, a powerful alternative to Derivative Spectrophotometry in analysis of binary and ternary mixtures: A comparative study.

    Science.gov (United States)

    Elzanfaly, Eman S; Hassan, Said A; Salem, Maissa Y; El-Zeany, Badr A

    2015-12-05

    A comparative study was established between two signal processing techniques showing the theoretical algorithm for each method and making a comparison between them to indicate the advantages and limitations. The methods under study are Numerical Differentiation (ND) and Continuous Wavelet Transform (CWT). These methods were studied as spectrophotometric resolution tools for simultaneous analysis of binary and ternary mixtures. To present the comparison, the two methods were applied for the resolution of Bisoprolol (BIS) and Hydrochlorothiazide (HCT) in their binary mixture and for the analysis of Amlodipine (AML), Aliskiren (ALI) and Hydrochlorothiazide (HCT) as an example for ternary mixtures. By comparing the results in laboratory prepared mixtures, it was proven that CWT technique is more efficient and advantageous in analysis of mixtures with severe overlapped spectra than ND. The CWT was applied for quantitative determination of the drugs in their pharmaceutical formulations and validated according to the ICH guidelines where accuracy, precision, repeatability and robustness were found to be within the acceptable limit. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Simultaneous spectrophotometric determination of binary mixtures of nickel, cobalt and vanadium with 3-(picolydene)benzenesulphonic acid 2-hydroxylhydrazone

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Vargas, M.; Milla, M.; Antequera, I.; Perez-Bustamante, J.A.

    1985-05-01

    The synthesis and characterization of a water-soluble reagent, 3-(picolydene)benzenesulphonic acid 2-hydroxybenzoylhydrazone, is described. The reagent is stable in aqueous media. The colour reactions with nickel(II), cobalt(II) and vanadium(V) ions in slightly acidic solutions have molar absorptivities in the range 1.4-3.6 x 10U l mol cm . Simultaneous determinations of Ni, Co and V in binary mixtures are possible. Interference data are reported.

  11. Partial molar volumes of aluminium chloride, aluminium sulphate and aluminium nitrate in water-rich binary aqueous mixtures of tetrahydrofuran

    OpenAIRE

    R. C. Thakur; Ravi Sharma; Ashish Kumar; Sanjay Kumar; M. L. Parmar

    2014-01-01

    Partial molar volumes of aluminium chloride, aluminium sulphate and aluminium nitrate have been determined in water rich binary aqueous mixtures of tetrahydrofuran (5, 10, 15, 20% by weight of tetrahydrofuran) with the help of density measurements. The density measurements were made by using Ward and Millero method and results have been analysed by Masson’s equation and interpreted in terms of ion-ion or ion –solvent interactions. The partial molar volumes vary with temperature as a power ser...

  12. Excess enthalpies of binary mixtures of 1-hexene with some branched alkanes at the temperature 298.15 K

    International Nuclear Information System (INIS)

    Wang, Zhaohui; Benson, George C.; Lu, Benjamin C.-Y.

    2004-01-01

    Measurements of excess molar enthalpies at the temperature 298.15 K in a flow microcalorimeter are reported for the five binary mixtures formed by mixing 1-hexene with the branched alkanes: 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, and 2,2,4-trimethylpentane. Smooth Redlich-Kister representations of the results are described. It was found that the Liebermann-Fried model also provided good representations of the results

  13. Calculation of Viscosity and Diffusion Coefficients for Two Binary Gaseous Mixtures Using the Semi-empirical Inversion Method

    Science.gov (United States)

    Rafiee, Hamid Reza; Rastgar, Mina; Heidari, Neda

    2011-08-01

    The accurate reduced potential energies for two binary gas mixtures including benzene-methanol and methane-tetrafluoromethane at low density have been obtained by direct inversion of the viscosity collision integral equations. The kinetic theory along with the extended principle of corresponding-states has been used to calculate the viscosity and diffusion coefficients over a wide range of temperature and composition. Good agreements between calculated and experimental data are obtained.

  14. DISSOLUTION AND COMPATIBILITY STUDY OF BINARY AND TERNARY INTERACTIVE MIXTURES OF INDOMETHACIN: COMPARISON WITH COMMERCIALLY AVAILABLE CAPSULES.

    Science.gov (United States)

    Maswadeh, Hamzah M

    2016-01-01

    The main objective of this work was to use Weibull distribution function and Baker-Lonsdale models to study the dissolution kinetics of prepared binary and ternary interactive mixtures containing indomethacin in comparison with three commercially available capsules of indomethacin, namely, Rothacin®, Indomin® and Indylon®. Differential scanning calorimetry (DSC) in conjunction with cloud point method was used to study the compatibility of indomethacin with polyvinylpyrrolidone (PVP) and lactose and to provide an explanation(s) for the insignificant increase in dissolution rate observed in the ternary interactive mixture as well as for the reduction in the dissolution rate observed from the binary system in our previous study. Results showed that the Weibull distribution function equation was the best fit to the dissolution data for all formulations used in this study. DSC curves showed that the decrease in dissolution rate from the binary and ternary interactive mixtures was due to incompatibility of indomethacin with PVP. Also DSC curves showed that lactose was compatible with indomethacin and that lactose was used as excipient in two commercial products (Rothacin® and Indylon®). Results from the cloud point method showed that the addition of indomethacin to 1% PVP solution containing ammonium sulfate (with cloud point at 76°C) reduces the cloud point of PVP indicating that there is an interaction between indomethacin and PVP, while the cloud point of 1% PVP containing ammonium sulfate was not affected by the addition of lactose.

  15. Long-term effects of a binary mixture of perfluorooctane sulfonate (PFOS) and bisphenol A (BPA) in zebrafish (Danio rerio)

    DEFF Research Database (Denmark)

    Keiter, Susanne; Baumann, Lisa; Farber, H

    2012-01-01

    aimed at evaluating the long-term effects and toxicity-increasing behavior of PFOS in vivo using the zebrafish (Danio rerio). Fish were maintained in flow-through conditions and exposed to single and binary mixtures of PFOS and the endocrine disruptor bisphenol A (BPA) at nominal concentrations of 0...... seen in the F1 generation in any treatment following 180 d exposure; however, in the F2 generation, 300mug/L PFOS both alone and in combination with BPA (10, 200 and 400mug/L) induced 100% mortality within 14 dpf. PFOS (0.6 and 300mug/L) did not increase the Vtg-inducing potential of BPA (10, 200...... and 400mug/L) in a binary mixture. In contrast, binary mixtures with 300mug/L PFOS suppressed the Vtg levels in F1 males at 90 dpf when compared to single BPA exposures. Whereas the lowest tested PFOS concentration (0.6mug/L) showed an estrogenic potential in terms of significant Vtg induction, Vtg levels...

  16. Effects of binary mixtures of xenoestrogens on gonadal development and reproduction in zebrafish.

    Science.gov (United States)

    Lin, Leo L; Janz, David M

    2006-12-30

    Previous studies exposing fish to xenoestrogens have demonstrated vitellogenin (VTG) induction, delayed gametogenesis, altered sex ratio, and decreased reproductive performance, with a majority of those studies focusing on exposure to single chemicals. The objective of this study was to determine the effects of binary mixtures of a weak estrogen receptor agonist, nonylphenol (NP) and a potent estrogen receptor agonist, 17alpha-ethinylestradiol (EE) on sex ratios, gametogenesis, VTG induction, heat shock protein 70 (HSP70) expression and reproductive capacity in zebrafish (Danio rerio). Fish were exposed from 2 to 60 days post-hatch (dph) to nominal concentrations of 10 or 100 microg/l NP (NP10 or NP100, respectively), 1 or 10 ng/l EE (EE1 or EE10, respectively), 1 ng/l EE+10 or 100 microg/l NP (EE1+NP10 or EE1+NP100, respectively), 10 ng/l EE+10 or 100 microg/l NP (EE10+NP10 or EE10+NP100, respectively) or solvent control (0.01% acetone, v/v) in a static-renewal system with replacement every 48 h. At 60 dph, fish from each treatment were euthanized for histological examination of gonads, and whole body VTG and HSP70 levels. Remaining fish were reared in clean water until adulthood (240 dph) for breeding studies. In all EE10 exposure groups (EE10, EE10+NP10 and EE10+NP100), increasing NP concentration acted antagonistically to the action of EE in terms of VTG induction at 60 dph. Similarly, non-additivity was observed with egg production, where EE1+NP100 exposure resulted in significantly more eggs produced per breeding trial than EE1 alone. Histological staging of oogenesis revealed suppressed gametogenesis in an additive fashion in females at 60 dph. There were no differences among treatment groups in whole body HSP70 expression in 60 dph fish or in gonadal HSP70 expression in adult fish. Although there was no statistical evidence of non-additivity, breeding trials in adults revealed significant reductions in egg viability, egg hatchability and/or F1 swim

  17. Soret and thermosolutal effects on natural convection in a shallow cavity filled with a binary mixture

    Energy Technology Data Exchange (ETDEWEB)

    Alloui, I., E-mail: imene.alloui@gmail.co [Universite Kasdi Merbah, BP 156 Rouissat, Ouargla 30130 (Algeria); Benmoussa, H. [Universite Hadj Lakhdar, 1 rue Chahid Boukhlouf, Batna 05000 (Algeria); Vasseur, P. [Ecole Polytechnique, C.P. 6079, Succ ' Center Ville' , Montreal, Quebec, H3C 3A7 (Canada)

    2010-04-15

    This paper reports an analytical and numerical study of the combined Soret and thermosolutal effects on natural convection in a shallow rectangular cavity filled with a binary mixture. Neumann boundary conditions for temperature and concentration are applied to the horizontal walls of the enclosure, while the two vertical ones are assumed impermeable and insulated. The governing parameters for the problem are the thermal Rayleigh number, Ra{sub T}, the Lewis number Le, the buoyancy ratio phi, the solute flux imposed on the horizontal boundaries j, the Prandtl number Pr, the aspect ratio of the cavity A, and the real number a (a = 0 for double diffusive convection and a = 1 for the coexistence of double diffusion convection and Soret effect). For convection in an infinite layer (A >> 1), analytical solutions for the stream function, temperature and concentration fields are obtained using a parallel flow approximation in the core region of the cavity and an integral form of the energy and constituent equations. The critical Rayleigh numbers for the onset of supercritical and subcritical convection are predicted explicitly by the present model. A linear stability analysis of the parallel flow model is conducted and the critical Rayleigh number for the onset of Hopf's bifurcation is predicted numerically. Also, results are obtained for finite amplitude convection for which the flow and heat and solute transfers are presented in terms of the governing parameters of the problem. Numerical solutions of the full governing equations are obtained for a wide range of the governing parameters. A good agreement is observed between the analytical model and the numerical simulations.

  18. The Modified Leung-Griffiths Model of Vapor-Liquid Equilibrium: Developments for Binary Mixtures of Dissimilar Fluids.

    Science.gov (United States)

    Lynch, John James

    1990-01-01

    The modified Leung-Griffiths model is a corresponding states theory applied to mixtures that successfully correlates, evaluates, and predicts vapor-liquid equilibrium (VLE) boundaries for binary fluid mixtures. The strength of the model lies in its excellent performance at and near the critical locus down to about half of the critical pressures. Conventional phase equilibrium algorithms based on classical equations of state generally fail to converge or are inaccurate near the critical locus. The modified Leung-Griffiths model, however, incorporates nonclassical, scaling-law critical exponents. Because of the universality of critical behavior, the technique is relatively insensitive to phenomena such as polarity or hydrogen bonding which usually cause severe calculation problems. This thesis covers several topics. The first is an investigation into some of the near-critical phenomena of binary fluid mixtures using asymptotic expansions. Dew -bubble curves are expanded through five orders about the critical locus within the formalism of the model. Explicit mathematical representations of the curves are obtained and the coefficients of the expansions are closely evaluated. Another subject, one that has had a significant impact on the progress of the remainder of the work, is the problem of fitting VLE data to non-linear functions. This problem is discussed and examples of systematic non-linear fits are presented. The next topic is the incorporation of "extended scaling," the Wegner correction, into the theory. This extension improves the performance of the model for binary mixtures with wide dew-bubble curves, that is mixtures with two highly dissimilar components. Finally, a study of the predictive capabilities and limitations of the model is presented.

  19. Measurements and equation-of-state modelling of thermodynamic properties of binary mixtures of 1-butyl-1-methylpyrrolidinium tetracyanoborate ionic liquid with molecular compounds

    International Nuclear Information System (INIS)

    Paduszyński, Kamil; Lukoshko, Elena V.; Królikowski, Marek; Domańska, Urszula

    2015-01-01

    Highlights: • Solubility data for 10 molecular solvents in [BMPYR][TCB] are reported. • Excess enthalpies for 7 molecular solvents in [BMPYR][TCB] are given. • Thermodynamic modelling with PC-SAFT equation of state is presented. - Abstract: This paper presents a comprehensive thermodynamic study of binary mixtures formed by 1-butyl-1-methylpyrrolidinium tetracyanoborate ionic liquid and hydrocarbons (n-heptane, benzene, toluene, ethylbenzene), thiophene and alcohols (methanol, ethanol, 1-propanol, 1-butanol, 1-hexanol, 1-octanol, 1-decanol and 1-dodecanol). An impact of chemical structure of molecular compounds on their solubility in the ionic liquid and excess enthalpies of mixing is discussed. Furthermore, modelling of the measured properties by using perturbed-chain statistical associating fluid theory (PC-SAFT) is presented. The theory is applied in both correlative and semi-predictive mode involving temperature-dependent binary corrections fitted to infinite dilution activity coefficients. Solubility curves and excess enthalpies are captured by the model with a reasonable accuracy, when semi-predictive strategy is adopted. Moreover, (liquid + liquid) equilibrium phase diagram in ternary system composed of the investigated ionic liquid, thiophene and n-heptane is predicted with PC-SAFT and then the calculations are confronted with available experimental data. The results indicate that the approach proposed can be perceived as an interesting tool for reproducing the thermodynamic behaviour disclosed by such complex systems as those based on ionic liquids

  20. Thermodynamic study of binary mixtures of 1-butyl-1-methylpyrrolidinium dicyanamide ionic liquid with molecular solvents: new experimental data and modeling with PC-SAFT equation of state.

    Science.gov (United States)

    Paduszyński, Kamil; Lukoshko, Elena Vadimovna; Królikowski, Marek; Domańska, Urszula; Szydłowski, Jerzy

    2015-01-15

    This work is concerned with thermodynamic properties of binary mixtures composed of 1-butyl-1-methylpyrrolidinium dicyanamide ionic liquid (IL) and the following molecular solvents: n-heptane, benzene, toluene, ethylbenzene, thiophene, 1-butanol, 1-hexanol, and 1-octanol. This is the very first time when experimental data on liquid-liquid equilibrium (LLE) phase diagrams and excess enthalpies of mixing (H(E)) for these systems are reported. An impact of the molecular solvent structure on LLE and H(E) is discussed. Furthermore, modeling of the properties under study is presented by using perturbed-chain statistical associating fluid theory (PC-SAFT). The equation of state is used in purely predictive and semipredictive mode. The latter one involves temperature-dependent binary corrections to combining rules employed in the PC-SAFT model determined on the basis of infinite dilution activity coefficients. The results shown indicate that such an approach can serve as an interesting modern thermodynamic tool for representation of thermodynamic data for complex ILs-based systems.

  1. New Flexible Models and Design Construction Algorithms for Mixtures and Binary Dependent Variables

    OpenAIRE

    Ruseckaite, Aiste

    2017-01-01

    markdownabstractThis thesis discusses new mixture(-amount) models, choice models and the optimal design of experiments. Two chapters of the thesis relate to the so-called mixture, which is a product or service whose ingredients’ proportions sum to one. The thesis begins by introducing mixture models in the choice context and develops new optimal design construction algorithms for choice experiments involving mixtures. Building further, varying the total amount of a mixture, and not only its i...

  2. Binary and Tertiary Mixtures of Satureja hortensis and Origanum vulgare Essential Oils as Potent Antimicrobial Agents Against Helicobacter pylori.

    Science.gov (United States)

    Lesjak, Marija; Simin, Natasa; Orcic, Dejan; Franciskovic, Marina; Knezevic, Petar; Beara, Ivana; Aleksic, Verica; Svircev, Emilija; Buzas, Krisztina; Mimica-Dukic, Neda

    2016-03-01

    Essential oils possess strong antimicrobial activity, even against multiresistant Helicobacter pylori. Available therapies against H. pylori infection have multiple disadvantages, indicating a great need for a development of new therapeutics. The purpose of this study was to develop a potent natural product based anti-H. pylori formulation. First, anti-H. pylori activity of nine essential oils was determined, after which the most active oils were mixed in various ratios for further testing. Satureja hortensis, Origanum vulgare subsp. vulgare and O. vulgare subsp. hirtum essential oils expressed the highest activity (MIC = 2 μL mL(-1)). Their binary and ternary mixtures exhibited notably higher antimicrobial activity (MIC ≤ 2 μL mL(-1)). The most active was the mixture of S. hortensis and O. vulgare subsp. hirtum oils in volume ratio 2:1, which expressed 4 times higher activity than individual oils (MIC = 0.5 μL mL(-1)). According to GC-MS, both oils in the mixture were characterized by high content of phenols (48-73%), with carvacrol as the main carrier of antimicrobial activity. Presented in vitro study pointed out binary mixture of S. hortensis and O. vulgare subsp. hirtum essential oils in volume ratio 2:1 as promising candidate for further in vivo studies targeting H. pylori infection. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Phase Transitions of Binary Lipid Mixtures: A Combined Study by Adiabatic Scanning Calorimetry and Quartz Crystal Microbalance with Dissipation Monitoring

    Directory of Open Access Journals (Sweden)

    P. Losada-Pérez

    2015-01-01

    Full Text Available The phase transitions of binary lipid mixtures are studied by a combination of Peltier-element-based adiabatic scanning calorimetry (pASC and quartz crystal microbalance with dissipation monitoring (QCM-D. pASC, a novel type of calorimeter, provides valuable and unambiguous information on the heat capacity and the enthalpy, whereas QCM-D is proposed as a genuine way of determining phase diagrams by analysing the temperature dependence of the viscosity. Two binary mixtures of phospholipids with the same polar head and differing in the alkyl chain length, DMPC + DPPC and DMPC + DSPC, are discussed. Both techniques give consistent phase diagrams, which compare well with literature results, showing their capability to map the phase behaviour of pure lipids as well as lipid mixtures. This work can be considered as a departure point for further investigations on more complex lipid mixtures displaying relevant phases such as the liquid-ordered phase and solid-lipid interfaces with biologically functional importance.

  4. Secular dynamics of hierarchical multiple systems composed of nested binaries, with an arbitrary number of bodies and arbitrary hierarchical structure. II. External perturbations: flybys and supernovae

    Science.gov (United States)

    Hamers, Adrian S.

    2018-02-01

    We extend the formalism of a previous paper to include the effects of flybys and instantaneous perturbations such as supernovae on the long-term secular evolution of hierarchical multiple systems with an arbitrary number of bodies and hierarchy, provided that the system is composed of nested binary orbits. To model secular encounters, we expand the Hamiltonian in terms of the ratio of the separation of the perturber with respect to the barycentre of the multiple system, to the separation of the widest orbit. Subsequently, we integrate over the perturber orbit numerically or analytically. We verify our method for secular encounters, and illustrate it with an example. Furthermore, we describe a method to compute instantaneous orbital changes to multiple systems, such as asymmetric supernovae and impulsive encounters. The secular code, with implementation of the extensions described in this paper, is publicly available within AMUSE, and we provide a number of simple example scripts to illustrate its usage for secular and impulsive encounters, and asymmetric supernovae. The extensions presented in this paper are a next step toward efficiently modeling the evolution of complex multiple systems embedded in star clusters.

  5. Electric Double Layer Composed of an Antagonistic Salt in an Aqueous Mixture: Local Charge Separation and Surface Phase Transition.

    Science.gov (United States)

    Yabunaka, Shunsuke; Onuki, Akira

    2017-09-15

    We examine an electric double layer containing an antagonistic salt in an aqueous mixture, where the cations are small and hydrophilic but the anions are large and hydrophobic. In this situation, a strong coupling arises between the charge density and the solvent composition. As a result, the anions are trapped in an oil-rich adsorption layer on a hydrophobic wall. We then vary the surface charge density σ on the wall. For σ>0 the anions remain accumulated, but for σ<0 the cations are attracted to the wall with increasing |σ|. Furthermore, the electric potential drop Ψ(σ) is nonmonotonic when the solvent interaction parameter χ(T) exceeds a critical value χ_{c} determined by the composition and the ion density in the bulk. This leads to a first-order phase transition between two kinds of electric double layers with different σ and common Ψ. In equilibrium such two-layer regions can coexist. The steric effect due to finite ion sizes is crucial in these phenomena.

  6. Experimental investigations of density-induced segregation in binary granular mixtures under vertical vibrations

    Science.gov (United States)

    Yachai, Tanapon; Preechawuttipong, Itthichai; Jongchansitto, Pawarut

    2018-01-01

    The objective of this work is aimed to investigate experimentally the influences of density ratio on segregation of cylindrical granular mixtures under vertical vibrations. Polytetrafluoroethylene, Polyamide, Polyethylene terephthalate, Balsa woods and Hinoki woods were used as the cylindrical particles, with 10 mm in diameter and 60 mm in length. The granular sample is composed of 1000 particles with two different materials with each type of 500 particles. All particles are periodically filled into the rectangular container with size 300 x 300 x 60 mm, as the initial condition. Density ratios are 2.73, 3.36, 5.27, and 13.63. The experimental operated by vertical shaker for 10 minute to achieve a steady state condition with same amplitude at 5 mm. The dimensionless vibration accelerations changed by frequency for 5 experimental, experiment the dimensionless vibration accelerations = 1, 2, 3, 4, and 5. The beginning state and the end state collected data by shooting the image. The segregation is considered by average height or the segregation coefficient. The result showed that for the density ratios of 2.73 and 3.36 for all dimensionless acceleration values, the segregation does not occur. On the other hand, for density ratio more than 5.27, the segregation occur by the way that the higher density particles move downward to the bottom of the sample, while the lower density particles move up to the top of the container. The segregation occurs when the dimensionless acceleration is more than 2 and the segregation is clearer when the dimensionless acceleration increases.

  7. New Flexible Models and Design Construction Algorithms for Mixtures and Binary Dependent Variables

    NARCIS (Netherlands)

    A. Ruseckaite (Aiste)

    2017-01-01

    markdownabstractThis thesis discusses new mixture(-amount) models, choice models and the optimal design of experiments. Two chapters of the thesis relate to the so-called mixture, which is a product or service whose ingredients’ proportions sum to one. The thesis begins by introducing mixture

  8. The Precise Measurement of Vapor-Liquid Equilibrium Properties of the CO2/Isopentane Binary Mixture, and Fitted Parameters for a Helmholtz Energy Mixture Model

    Science.gov (United States)

    Miyamoto, H.; Shoji, Y.; Akasaka, R.; Lemmon, E. W.

    2017-10-01

    Natural working fluid mixtures, including combinations of CO2, hydrocarbons, water, and ammonia, are expected to have applications in energy conversion processes such as heat pumps and organic Rankine cycles. However, the available literature data, much of which were published between 1975 and 1992, do not incorporate the recommendations of the Guide to the Expression of Uncertainty in Measurement. Therefore, new and more reliable thermodynamic property measurements obtained with state-of-the-art technology are required. The goal of the present study was to obtain accurate vapor-liquid equilibrium (VLE) properties for complex mixtures based on two different gases with significant variations in their boiling points. Precise VLE data were measured with a recirculation-type apparatus with a 380 cm3 equilibration cell and two windows allowing observation of the phase behavior. This cell was equipped with recirculating and expansion loops that were immersed in temperature-controlled liquid and air baths, respectively. Following equilibration, the composition of the sample in each loop was ascertained by gas chromatography. VLE data were acquired for CO2/ethanol and CO2/isopentane binary mixtures within the temperature range from 300 K to 330 K and at pressures up to 7 MPa. These data were used to fit interaction parameters in a Helmholtz energy mixture model. Comparisons were made with the available literature data and values calculated by thermodynamic property models.

  9. Isothermal (vapour + liquid) equilibrium (VLE) for binary mixtures containing diethyl carbonate, phenyl acetate, diphenyl carbonate, or ethyl acetate

    International Nuclear Information System (INIS)

    Ho, Hsiao-Yun; Shu, So-Siou; Wang, San-Jang; Lee, Ming-Jer

    2015-01-01

    Highlights: • Isothermal (vapour + liquid) equilibrium (VLE) data were measured. • Binary mixtures contain ethyl acetate, diethyl carbonate, phenyl acetate, diphenyl carbonate. • No azeotrope formed in the systems investigated. • The VLE data were correlated well with Wilson-HOC, NRTL-HOC, UNIQUAC-HOC models. - Abstract: The isothermal (vapour + liquid) equilibrium (VLE) (P–T–x i –y i ) was determined the binary systems of (ethyl acetate + diethyl carbonate) from T = (373.2 to 453.2) K, (ethyl acetate + phenyl acetate) at T = 373.2 K, and (diethyl carbonate + phenyl acetate) at T = 373.2 K, while the VLE (P–T–x i ) of three diphenyl carbonate-containing binary systems was also determined experimentally at temperatures from (373.2 to 453.2) K. The experimental results show no azeotrope formation and near ideal solution behaviour for each binary system. These new VLE (P–T–x i –y i ) data have been passed by the point, area, and infinite dilution thermodynamic consistency tests. The Wilson-HOC, the NRTL-HOC, and the UNIQUAC-HOC models were applied to correlate the VLE results and the optimal values of the model parameters have been determined through data reduction. Comparable results were obtained from these three models.

  10. Molecular investigation on the binding of Cd(II) by the binary mixtures of montmorillonite with two bacterial species

    Energy Technology Data Exchange (ETDEWEB)

    Du, Huihui; Qu, ChenChen; Liu, Jing; Chen, Wenli; Cai, Peng; Shi, Zhihua; Yu, Xiao-Ying; Huang, Qiaoyun

    2017-10-01

    Bacteria and phyllosilicate commonly coexist in the natural environment, producing various bacteria–clay complexes that are capable of immobilizing heavy metals, such as cadmium, via adsorption. However, the molecular binding mechanisms of heavy metals on these complex aggregates still remain poorly understood. This study investigated Cd adsorption on Gram-positive B. subtilis, Gram-negative P. putida and their binary mixtures with montmorillonite (Mont) using the Cd K-edge x-ray absorption spectroscopy (XAS) and isothermal titration calorimetry (ITC). We observed a lower adsorptive capacity for P. putida than B. subtilis, whereas P. putida–Mont and B. subtilis–Mont mixtures showed nearly identical Cd adsorption behaviors. EXAFS fits and ITC measurements demonstrated more phosphoryl binding of Cd in P. putida. The decreased coordination of C atoms around Cd and the reduced adsorption enthalpies and entropies for the binary mixtures compared to that for individual bacteria suggested that the bidentate Cd-carboxyl complexes in pure bacteria systems were probably transformed into monodentate complexes that acted as ionic bridging structure between bacteria and motmorillonite. This study clarified the binding mechanism of Cd at the bacteria–phyllosilicate interfaces from a molecular and thermodynamic view, which has an environmental significance for predicting the chemical behavior of trace elements in complex mineral–organic systems.

  11. Molecular simulation of homogeneous crystal nucleation of AB2 solid phase from a binary hard sphere mixture

    Science.gov (United States)

    Bommineni, Praveen Kumar; Punnathanam, Sudeep N.

    2017-08-01

    Co-crystal formation from fluid-mixtures is quite common in a large number of systems. The simplest systems that show co-crystal (also called substitutionally ordered solids) formation are binary hard sphere mixtures. In this work, we study the nucleation of AB2 type solid compounds using Monte Carlo molecular simulations in binary hard sphere mixtures with the size ratio of 0.55. The conditions chosen for the study lie in the region where nucleation of an AB2 type solid competes with that of a pure A solid with a face-centered-cubic structure. The fluid phase composition is kept equal to that of the AB2 type solid. The nucleation free-energy barriers are computed using the seeding technique of Sanz et al. [J. Am. Chem. Soc. 135, 15008 (2013)]. Our simulation results show that the nucleation of the AB2 type solid is favored even under conditions where the pure A solid is more stable. This is primarily due to the similarity in the composition of the fluid phase and the AB2 type solid which in turn leads to much lower interfacial tension between the crystal nucleus and the fluid phase. This system is an example of how the fluid phase composition affects the structure of the nucleating solid phase during crystallization and has relevance to crystal polymorphism during crystallization processes.

  12. Investigating the Effect of the Binary Mixtures Composition of Noble Gases on Their Thermodynamic and Transport Properties

    Directory of Open Access Journals (Sweden)

    S. A. Burtsev

    2015-01-01

    Full Text Available The paper presents possible application fields of the binary noble gas mixtures with low Prandtl numbers. It shows that it is expedient to select these mixtures as the working fluids for closed Brayton cycle gas-turbine installations, thermo-acoustic engines and for the gas dynamic energy separation device (Leontiev tube. As follows from the analysis, He-Ar, He-Kr, and HeXe mixtures have proven to be the most attractive choice. The paper has analyzed the calculation results for coefficient of dynamic viscosity, coefficient of thermal conductivity, and for heat capacity at constant pressure for the given mixtures in terms of mixture molecular weights at pressures of 2MPa and 7MPa and temperatures of 400 and 1200°K. According to data of experiments and calculations available in public sources published by another authors, the results are verified. It was found that at constant pressure within the examined range of parameters (i.e. pressure, temperature, mixture molecular weight the obtained heat capacity values are in good agreement with the values of the verification data. In calculating dynamic viscosity coefficient for any pressure and temperature the utilized technique provides results for He-Ar and He-Kr mixtures within the entire range of the molecular weights, which are, essentially, as good as shown by international verification techniques. However, at high pressures and low temperatures for He-Xe mixture with molecular weights close to the pure Xe the divergence was found to be as high as 25 % while for other parameter intervals under consideration and with the same mixture the difference does not exceed 10 %. A good agreement with the verification data is observed for the values of a thermal conductivity coefficient of He-Ar and He-Kr mixtures for any value of parameters, while for He-Xe mixture with molecular weights close to 60 g/mole independently of pressure the divergence can reach 30 % for 1200°K and 20 % for 400°K. It is shown

  13. Study of the Transformations of Micro/Nano-crystalline Acetaminophen Polymorphs in Drug-Polymer Binary Mixtures.

    Science.gov (United States)

    Maniruzzaman, Mohammed; Lam, Matthew; Molina, Carlos; Nokhodchi, Ali

    2017-07-01

    This study elucidates the physical properties of sono-crystallised micro/nano-sized acetaminophen/paracetamol (PMOL) and monitors its possible transformation from polymorphic form I (monoclinic) to form II (orthorhombic). Hydrophilic Plasdone® S630 copovidone (S630), N-vinyl-2-pyrrolidone and vinyl acetate copolymer, and methacrylate-based cationic copolymer, Eudragit® EPO (EPO), were used as polymeric carriers to prepare drug/polymer binary mixtures. Commercially available PMOL was crystallised under ultra sound sonication to produce micro/nano-sized (0.2-10 microns) crystals in monoclinic form. Homogeneous binary blends of drug-polymer mixtures at various drug concentrations were obtained via a thorough mixing. The analysis conducted via the single X-ray crystallography determined the detailed structure of the crystallised PMOL in its monoclinic form. The solid state and the morphology analyses of the PMOL in the binary blends evaluated via differential scanning calorimetry (DSC), modulated temperature DSC (MTDSC), scanning electron microscopy (SEM) and hot stage microscopy (HSM) revealed the crystalline existence of the drug within the amorphous polymeric matrices. The application of temperature controlled X-ray diffraction (VTXRPD) to study the polymorphism of PMOL showed that the most stable form I (monoclinic) was altered to its less stable form II (orthorhombic) at high temperature (>112°C) in the binary blends regardless of the drug amount. Thus, VTXRD was used as a useful tool to monitor polymorphic transformations of crystalline drug (e.g. PMOL) to assess their thermal stability in terms of pharmaceutical product development and research.

  14. A volumetric and viscosity study for the binary mixtures of 1-hexyl-3-methylimidazolium tetrafluoroborate with some molecular solvents

    International Nuclear Information System (INIS)

    Zhu Anlian; Wang Jianji; Liu Ruixia

    2011-01-01

    Research highlights: → Excess molar volumes and excess logarithm viscosities for the binary mixtures of 1-hexyl-3-methylimidazolium tetrafluroborate were determined. → The absolute values of V m E follow the sequence: THF > butanone > ethyl acetate > butylamine for the binary systems. → The values of (lnη) E decrease in the order: THF > butylamine > ethyl acetate > butanone. → Ion-dipole interaction, the hydrogen bond, the packing efficiency and the ion-pairs exist in the ionic liquid are believed to influence the excess properties of the related systems. → The information obtained in this work allows us to show how physical properties of molecular solvents affect their interaction with the ionic liquid. - Abstract: Information on the interactions between ionic liquids and molecular solvents are essential for the understanding of the function of ionic liquids in related procedures, and excess properties are sensitive probe for these interactions. In this work, excess molar volume (V m E ) and excess logarithmic viscosity ((ln η) E ) for the binary mixtures of 1-hexyl-3-methylimidazolium tetrafluoroborate ([C 6 mim][BF 4 ]) with butanone, ethyl acetate, butylamine, and tetrahydrofuran have been determined from density and viscosity measurements in the whole composition range at the temperature of 298.15 K. It is found that for the studied systems, the values of V m E are negative but those of (ln η) E are positive in the whole concentration range. The V m E values show their minimum at the ionic liquid mole fraction of 0.3, and (ln η) E values exhibit a maximum at the same composition. The absolute values of V m E follow the sequence: tetrahydrofuran > butanone > ethyl acetate > butylamine for the binary systems, whereas the values of (ln η) E decrease in the order: tetrahydrofuran > butylamine > ethyl acetate > butanone. The results have been analyzed through the ion-dipole interaction, the hydrogen bonding, the packing efficiency and the ion

  15. Experimental and theoretical excess molar enthalpies of ternary and binary mixtures containing 2-Methoxy-2-Methylpropane, 1-propanol, heptane

    International Nuclear Information System (INIS)

    Mato, Marta M.; Cebreiro, Susana M.; Paz Andrade, María Inmaculada; Legido, José Luis

    2013-01-01

    Highlights: • Experimental enthalpies for the ternary system MTBE + propanol + heptane were measured. • No experimental ternary values were found in the currently available literature. • Experimental enthalpies for the binary system propanol + heptane were measured. • Excess molar enthalpies are positive over the whole range of composition. • The ternary contribution is also positive, and the representation is asymmetric. -- Abstract: Excess molar enthalpies, at the temperature of 298.15 K and atmospheric pressure, have been measured for the ternary system {x 1 2-Methoxy-2-Methylpropane (MTBE) + x 2 1-propanol + (1 − x 1 − x 2 ) heptane}, over the whole composition range. Also, experimental data of excess molar enthalpy for the involved binary mixture {x 1-propanol + (1 − x) heptane} at the 298.15 K and atmospheric pressure, are reported. We are not aware of any previous experimental measurement of excess enthalpy in the literature for the ternary system presented in this study. Values of the excess molar enthalpies were measured using a Calvet microcalorimeter. The ternary contribution to the excess enthalpy was correlated with the equation due to Morris et al. (1975) [15], and the equation proposed by Myers–Scott (1963) [14] was used to fitted the experimental binary mixture measured in this work. Additionally, the experimental results are compared with the estimations obtained by applying the group contribution model of UNIFAC, in the versions of Larsen et al. (1987) [16] and Gmehling et al. (1993) [17]. Several empirical expressions for estimating ternary properties from binary results were also tested

  16. Competitive adsorption of a binary CO2-CH4 mixture in nanoporous carbons: effects of edge-functionalization.

    Science.gov (United States)

    Lu, Xiaoqing; Jin, Dongliang; Wei, Shuxian; Zhang, Mingmin; Zhu, Qing; Shi, Xiaofan; Deng, Zhigang; Guo, Wenyue; Shen, Wenzhong

    2015-01-21

    The effect of edge-functionalization on the competitive adsorption of a binary CO2-CH4 mixture in nanoporous carbons (NPCs) has been investigated for the first time by combining density functional theory (DFT) and grand canonical Monte Carlo (GCMC) simulation. Our results show that edge-functionalization has a more positive effect on the single-component adsorption of CO2 than CH4, therefore significantly enhancing the selectivity of CO2 over CH4, in the order of NH2-NPC > COOH-NPC > OH-NPC > H-NPC > NPC at low pressure. The enhanced adsorption originates essentially from the effects of (1) the conducive environment with a large pore size and an effective accessible surface area, (2) the high electronegativity/electropositivity, (3) the strong adsorption energy, and (4) the large electrostatic contribution, due to the inductive effect/direct interaction of the embedded edge-functionalized groups. The larger difference from these effects results in the higher competitive adsorption advantage of CO2 in the binary CO2-CH4 mixture. Temperature has a negative effect on the gas adsorption, but no obvious influence on the electrostatic contribution on selectivity. With the increase of pressure, the selectivity of CO2 over CH4 first decreases sharply and subsequently flattens out to a constant value. This work highlights the potential of edge-functionalized NPCs in competitive adsorption, capture, and separation for the binary CO2-CH4 mixture, and provides an effective and superior alternative strategy in the design and screening of adsorbent materials for carbon capture and storage.

  17. Experimental determination and prediction of (solid+liquid) phase equilibria for binary mixtures of heavy alkanes and fatty acids

    Science.gov (United States)

    Benziane, Mokhtar; Khimeche, Kamel; Dahmani, Abdellah; Nezar, Sawsen; Trache, Djalal

    2012-06-01

    Solid-liquid equilibria for three binary mixtures, n-Eicosane (1) + Lauric acid (2), n-Tetracosane (1) + Stearic acid (2), and n-Octacosane (1) + Palmitic acid (2), were measured using a differential scanning calorimeter. Simple eutectic behaviour was observed for these systems. The experimental results were correlated by means of the modified UNIFAC (Larsen and Gmehling versions), UNIQUAC and ideal models. The root-mean-square deviations of the solubility temperatures for all measured data vary from 0.26 to 3.15 K and depend on the particular model used. The best solubility correlation was obtained with the UNIQUAC model.

  18. Densities and excess volumes of binary mixtures of N,N-dimethylformamide with aromatic hydrocarbon at different temperature

    International Nuclear Information System (INIS)

    Peng Sanjun; Hou Haiyun; Zhou Congshan; Yang Tao

    2007-01-01

    Density of three binary mixtures formed by N,N-dimethylformamide (DMF) with aromatic hydrocarbon (one of benzene, toluene, and ethylbenzene) has been determined over the full range of compositions at the temperatures range (293.15 to 353.15)K and atmospheric pressure using a vibrating-tube densimeter. From these experiments, excess molar volumes (V m E ) could be calculated and fitted by the fourth-order Redlich-Kister equation, so the coefficients and the standard error (σ) could be got. Our result shows V m E decreases when temperature increases in the studied systems

  19. Physico-chemical properties of binary mixtures of aliphatic and aromatic solvents at 313 K on acoustical data

    Science.gov (United States)

    Dahire, S. L.; Morey, Y. C.; Agrawal, P. S.

    2015-12-01

    Density (ρ), viscosity (η), and ultrasonic velocity ( U) of binary mixtures of aliphatic solvents like dimethylformamide (DMF) and dimethylsulfoxide (DMSO) with aromatic solvents viz. chlorobenzene (CB), bromobenzene (BB), and nitrobenzene (NB) have been determined at 313 K. These parameters were used to calculate the adiabatic compressibility (β), intermolecular free length ( L f), molar volume ( V m), and acoustic impedance ( Z). From the experimental data excess molar volume ( V m E ), excess intermolecular free length ( L f E )), excess adiabatic compressibility (βE), and excess acoustic impedance ( Z E) have been computed. The excess values were correlated using Redlich-Kister polynomial equation to obtain their coefficients and standard deviations (σ).

  20. Extraction of uranium(VI) with binary mixtures of a quadridentate Schiff base and various neutral donors

    International Nuclear Information System (INIS)

    Sahu, S.K.; Chakravortty, V.

    1998-01-01

    Liquid-liquid extraction of uranium(VI) with the binary mixture of quadridentate Schiff base, bis-salicylidene ethylene diamine (H 2 Salen) (H 2 A) and neutral donors viz., triphenyl arsine oxide (TPAsO), triphenyl phosphine oxide (TPPO) and tri-n-octyl phosphine oxide (TOPO) has been studied. The extraction order in the equilibrium pH range 2.5 to 5.5 is found to be bis-salicylidene ethylene diamine 2 A x 2TOPO) and (UO 2 A x 2TPPO). (author)

  1. Coarse-grained modelling of triglyceride crystallisation: a molecular insight into tripalmitin tristearin binary mixtures by molecular dynamics simulations

    International Nuclear Information System (INIS)

    Pizzirusso, Antonio; De Nicola, Antonio; Milano, Giuseppe; Brasiello, Antonio; Marangoni, Alejandro G

    2015-01-01

    The first simulation study of the crystallisation of a binary mixture of triglycerides using molecular dynamics simulations is reported. Coarse-grained models of tristearin (SSS) and tripalmitin (PPP) molecules have been considered. The models have been preliminarily tested in the crystallisation of pure SSS and PPP systems. Two different quenching procedures have been tested and their performances have been analysed. The structures obtained from the crystallisation procedures show a high orientation order and a high content of molecules in the tuning fork conformation, comparable with the crystalline α phase. The behaviour of melting temperatures for the α phase of the mixture SSS/PPP obtained from the simulations is in qualitative agreement with the behaviour that was experimentally determined. (paper)

  2. Different signal processing techniques of ratio spectra for spectrophotometric resolution of binary mixture of bisoprolol and hydrochlorothiazide; a comparative study

    Science.gov (United States)

    Elzanfaly, Eman S.; Hassan, Said A.; Salem, Maissa Y.; El-Zeany, Badr A.

    2015-04-01

    Five signal processing techniques were applied to ratio spectra for quantitative determination of bisoprolol (BIS) and hydrochlorothiazide (HCT) in their binary mixture. The proposed techniques are Numerical Differentiation of Ratio Spectra (ND-RS), Savitsky-Golay of Ratio Spectra (SG-RS), Continuous Wavelet Transform of Ratio Spectra (CWT-RS), Mean Centering of Ratio Spectra (MC-RS) and Discrete Fourier Transform of Ratio Spectra (DFT-RS). The linearity of the proposed methods was investigated in the range of 2-40 and 1-22 μg/mL for BIS and HCT, respectively. The proposed methods were applied successfully for the determination of the drugs in laboratory prepared mixtures and in commercial pharmaceutical preparations and standard deviation was less than 1.5. The five signal processing techniques were compared to each other and validated according to the ICH guidelines and accuracy, precision, repeatability and robustness were found to be within the acceptable limit.

  3. Theory and simulations for hard-disk models of binary mixtures of molecules with internal degrees of freedom

    DEFF Research Database (Denmark)

    Fraser, Diane P.; Zuckermann, Martin J.; Mouritsen, Ole G.

    1991-01-01

    by the method in the case of a binary mixture, and results are presented for varying disk-size ratios and degeneracies. The results are also compared with the predictions of the extended scaled-particle theory. Applications of the model are discussed in relation to lipid monolayers spread on air......A two-dimensional Monte Carlo simulation method based on the NpT ensemble and the Voronoi tesselation, which was previously developed for single-species hard-disk systems, is extended, along with a version of scaled-particle theory, to many-component mixtures. These systems are unusual in the sense...... that their composition is not fixed, but rather determined by a set of internal degeneracies assigned to the differently sized hard disks, where the larger disks have the higher degeneracies. Such systems are models of monolayers of molecules with internal degrees of freedom. The combined set of translational...

  4. Glass transition behavior of octyl β-D-glucoside and octyl β-D-thioglucoside/water binary mixtures.

    Science.gov (United States)

    Ogawa, Shigesaburo; Asakura, Kouichi; Osanai, Shuichi

    2010-11-22

    The lyotropic behavior and glass-forming properties of octyl β-D-glucoside (C8Glu) and octyl β-D-thioglucoside (C8SGlu)/water binary mixtures were evaluated using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). The results clearly indicate that the mixture forms a glass in the supercooling state of liquid crystalline phases such as cubic, lamellar, and smectic. The glass transition temperature (T(g)) of the mixture was strongly dependent on solute concentration, with a higher concentration correlating with a higher T(g). The experimental T(g) was consistent with the predicted value calculated using the Couchman-Karasz equation in both the C8Glu and C8SGlu/water mixtures. The change of heat capacity at T(g) showed the two bending points under variation of concentrations. And the highest temperature of phase transition from lamellar to isotropic solution was observed at around 50% molar concentration. It was expected that non-percolated state of water existed in extremely higher concentration ranges. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Essential Oils of Hyptis pectinata Chemotypes: Isolation, Binary Mixtures and Acute Toxicity on Leaf-Cutting Ants.

    Science.gov (United States)

    Feitosa-Alcantara, Rosana B; Bacci, Leandro; Blank, Arie F; Alves, Péricles B; Silva, Indira Morgana de A; Soares, Caroline A; Sampaio, Taís S; Nogueira, Paulo Cesar de L; Arrigoni-Blank, Maria de Fátima

    2017-04-12

    Leaf-cutting ants are pests of great economic importance due to the damage they cause to agricultural and forest crops. The use of organosynthetic insecticides is the main form of control of these insects. In order to develop safer technology, the objective of this work was to evaluate the formicidal activity of the essential oils of two Hyptis pectinata genotypes (chemotypes) and their major compounds on the leaf-cutting ants Acromyrmex balzani Emery and Atta sexdens rubropilosa Forel. Bioassays of exposure pathways (contact and fumigation) and binary mixtures of the major compounds were performed. The major compounds identified in the essential oils of H. pectinata were β-caryophyllene, caryophyllene oxide and calamusenone. The essential oils of H. pectinata were toxic to the ants in both exposure pathways. Essential oils were more toxic than their major compounds alone. The chemotype calamusenone was more toxic to A. balzani in both exposure pathways. A. sexdens rubropilosa was more susceptible to the essential oil of the chemotype β-caryophyllene in both exposure pathways. In general, the binary mixtures of the major compounds resulted in additive effect of toxicity. The essential oils of H. pectinata is a raw material of great potential for the development of new insecticides.

  6. On the solid–liquid phase diagrams of binary mixtures of even saturated fatty alcohols: Systems exhibiting peritectic reaction

    Energy Technology Data Exchange (ETDEWEB)

    Carareto, Natália D.D. [EXTRAE, Department of Food Engineering, Food Engineering Faculty, University of Campinas, UNICAMP, CEP 13083-862 Campinas, SP (Brazil); Santos, Adenílson O. dos [Social Sciences, Health and Technology Center, University of Maranhão, UFMA, CEP 65900-410 Imperatriz, MA (Brazil); Rolemberg, Marlus P. [Institute of Science and Technology, University of Alfenas, UNIFAL, Rodovia José AurélioVilela, CEP 37715400 Poços de Caldas, MG (Brazil); Cardoso, Lisandro P. [Institute of Physics GlebWataghin, University of Campinas, UNICAMP, C.P. 6165, CEP 13083-970 Campinas, SP (Brazil); Costa, Mariana C. [School of Applied Science, University of Campinas, UNICAMP, CEP 13484-350 Limeira, SP (Brazil); Meirelles, Antonio J.A., E-mail: tomze@fea.unicamp.br [EXTRAE, Department of Food Engineering, Food Engineering Faculty, University of Campinas, UNICAMP, CEP 13083-862 Campinas, SP (Brazil)

    2014-08-10

    Highlights: • SLE of binary mixtures of saturated fatty alcohols was studied. • Experimental data were obtained using DSC and stepscan DSC. • Microscopy and X-ray diffraction used as complementary techniques. • Systems presented eutectic, peritectic and metatectic points. - Abstract: The solid–liquid phase diagrams of the following binary mixtures of even saturated fatty alcohols are reported in the literature for the first time: 1-octanol (C8OH) + 1-decanol (C10OH), 1-decanol + 1-dodecanol (C12OH), 1-dodecanol + 1-hexadecanol (C16OH) and 1-tetradecanol (C14OH) + 1-octadecanol (C18OH). The phase diagrams were obtained by differential scanning calorimetry (DSC) using a linear heating rate of 1 K min{sup −1} and further investigated by using a stepscan DSC method. X-ray diffraction (XRD) and polarized light microscopy were also used to complement the characterization of the phase diagrams which have shown a complex global behavior, presenting not only peritectic and eutectic reactions, but also the metatectic reaction and partial immiscibility on solid state.

  7. Excess molar volumes and viscosities of binary mixtures of 1, 2 ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 3. Excess molar volumes and viscosities of binary ... The deviations in viscosities (ln) and excess energies of activation ( *) for viscous flow have been calculated from the experimental data. The Prigogine-Flory-Patterson (PFP) model has been used ...

  8. The phase behavior of a hard sphere chain model of a binary n-alkane mixture

    International Nuclear Information System (INIS)

    Malanoski, A. P.; Monson, P. A.

    2000-01-01

    Monte Carlo computer simulations have been used to study the solid and fluid phase properties as well as phase equilibrium in a flexible, united atom, hard sphere chain model of n-heptane/n-octane mixtures. We describe a methodology for calculating the chemical potentials for the components in the mixture based on a technique used previously for atomic mixtures. The mixture was found to conform accurately to ideal solution behavior in the fluid phase. However, much greater nonidealities were seen in the solid phase. Phase equilibrium calculations indicate a phase diagram with solid-fluid phase equilibrium and a eutectic point. The components are only miscible in the solid phase for dilute solutions of the shorter chains in the longer chains. (c) 2000 American Institute of Physics

  9. Thermodynamics of mixtures containing amines. IX. Application of the concentration-concentration structure factor to the study of binary mixtures containing pyridines

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Juan Antonio, E-mail: jagl@termo.uva.es [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Cobos, Jose Carlos; Garcia de la Fuente, Isaias; Mozo, Ismael [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain)

    2009-10-10

    Binary mixtures formed by a pyridine base and an alkane, or an aromatic hydrocarbon, or a 1-alkanol have been studied in the framework of the concentration-concentration structure factor, S{sub CC}(0), formalism. Deviations between experimental data and those provided by the DISQUAC model are discussed. Systems containing alkanes are characterized by homocoordination. In pyridine + alkane mixtures, S{sub CC}(0) decreases with the chain length of the longer alkanes, due to size effects. For a given alkane, S{sub CC}(0) also decreases with the number of CH{sub 3}- groups in the pyridine base. This has been interpreted assuming that the number of amine-amine interactions available to be broken upon mixing also decreases similarly, probably as steric hindrances exerted by the methyl groups of the aromatic amine increase with the number of these groups. Homocoordination is higher in mixtures with 3,5-dimethylpyridine than in those with 2,6-dimethylpyridine. That is, steric effects exerted by methyl groups in positions 3 and 5 are stronger than when they are in positions 2 and 6. Similarly, from the application of the DISQUAC (dispersive-quasichemical) model, it is possible to conclude that homocoordination is higher in systems with 3- or 4-methylpyridine than in those involving 2-methylpyridine. Systems including aromatic hydrocarbons are nearly ideal, which seems to indicate that there is no specific interaction in such solutions. Mixtures with 1-alkanols show heterocoordination. This reveals the existence of interactions between unlike molecules, characteristic of alkanol + amine mixtures. Methanol systems show the lowest S{sub CC}(0) values due, partially, to size effects. This explains the observed decrease of homocoordination in such solutions in the order: pyridine > 2-methylpyridine > 2,6-dimethylpyridine. Moreover, as the energies of the OH-N hydrogen bonds are practically independent of the pyridine base considered when mixed with methanol, it suggests that

  10. Thermodynamic behavior of binary mixtures CnMpyNTf2 ionic liquids with primary and secondary alcohols

    International Nuclear Information System (INIS)

    Calvar, N.; Gómez, E.; Domínguez, Á.; Macedo, E.A.

    2012-01-01

    Highlights: ► Osmotic coefficients of alcohols with C n MpyNTf 2 (n = 2, 3, 4) are determined. ► Experimental data were correlated with Extended Pitzer model of Archer and MNRTL. ► Mean molal activity coefficients and excess Gibbs free energies were calculated. ► The results have been interpreted in terms of interactions. - Abstract: In this paper, the osmotic and activity coefficients and vapor pressures of the binary mixtures containing the ionic liquids 1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, C 2 MpyNTf 2 , and 1-methyl-3-propylpyridinium bis(trifluoromethylsulfonyl)imide, C 3 MpyNTf 2 , with 1-propanol, or 2-propanol and the ionic liquid 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, C 4 MpyNTf 2 , with 1-propanol or 2-propanol or 1-butanol or 2-butanol were determined at T = 323.15 K using the vapor pressure osmometry technique. The influence of the structure of the alcohol and of the ionic liquid on both coefficients and vapor pressures is discussed and a comparison with literature data on binary mixtures containing ionic liquids with different cations and anion is also performed. Besides, the results have been interpreted in terms of solute–solvent and ion–ion interactions. The experimental osmotic coefficients were correlated using the Extended Pitzer model of Archer and the Modified Non-Random Two Liquids model obtaining standard deviations lower than 0.059 and 0.102 respectively, and the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures were calculated.

  11. Experimental and predicted properties of the binary mixtures containing an isomeric chlorobutane and butyl ethyl ether

    International Nuclear Information System (INIS)

    Montaño, Diego; Gascón, Ignacio; Schmid, Bastian; Gmehling, Jürgen; Lafuente, Carlos

    2012-01-01

    Highlights: ► Volumetric properties of a chlorobutane + buty ethyl ether have been studied. ► Isothermal VLE of a chlorobutane + buty ethyl ether has been determined. ► Excess volumes and excess Gibbs energies have been obtained from experimental data. ► The VTPR model has been satisfactorily used to predict densities and VLE data. - Abstract: Densities of the binary systems containing an isomer of chlorobutane (1-chlorobutane, 2-chlorobutane, 2-methyl-1-chloropropane, or 2-methyl-2-chloropropane) and butyl ethyl ether have been measured over the temperature range (283.15 to 313.15) K. Moreover, isothermal (vapour + liquid) equilibria have also been determined at three temperatures (T = (288.15, 298.15, and 308.15) K). Excess properties have been obtained from the experimental data and correlated. Finally, the VTPR model has been used to predict densities and (vapour + liquid) equilibria of the binary systems studied.

  12. Densities and viscosities for binary mixtures of n-heptane with alcohols at different temperatures

    Directory of Open Access Journals (Sweden)

    Budeanu Maria Magdalena

    2017-01-01

    Full Text Available Densities (ρ and viscosities (η of the binary systems n-heptane with alcohols (ethanol, propan-1-ol and propan-2-ol were measured at temperatures between 288.15 and 308.15 K and at atmospheric pressure, over the whole composition range. The excess values of molar volume (VE and viscosity (ηE were calculated from experimental measurements. The excess functions of the binary systems were fitted to Redlich–Kister Equation. Comparison between experimental excess molar volume and the one calculated from Flory and Prigogine–Flory–Patterson theories, has also been done. The viscosity results were fitted to the equations of Grunberg–Nissan, Heric–Brewer, Jouyban–Acree and McAllister. Also, the activation energies of viscous flow have been obtained and their variations with compositions have been discussed.

  13. Ideal and non-ideal behaviour of {1-butyl-1-methylpyrrolydinium bis(trifluoromethylsulfonyl)imide + γ-butyrolactone} binary mixtures

    International Nuclear Information System (INIS)

    Vraneš, Milan; Tot, Aleksandar; Papović, Snežana; Zec, Nebojša; Dožić, Sanja; Gadžurić, Slobodan

    2015-01-01

    Graphical abstract: - Highlights: • Excess properties of ([bmpyrr][NTf 2 ] + γ-butyrolactone) mixtures are reported. • An ideal behaviour of the mixture was observed. • Interactions in the mixtures are weaker comparing to pure IL and GBL. • Calculated Angell’s strength parameter indicates a “fragile” ionic liquid. • [bmpyrr] + forms micellar structures when x IL > 0.6. - Abstract: Density, electrical conductivity and viscosity of binary liquid mixtures of 1-butyl-1-methylpyrrolydinium bis(trifluoromethylsulfonyl)imide, [bmpyrr][NTf 2 ], with γ-butyrolactone (GBL) were measured at temperatures from (293.15 to 323.15) K and at atmospheric pressure over the whole composition range. Excess molar volumes have been calculated from the experimental densities and fitted with the Redlich–Kister polynomial equation. These values are positive over the whole range of ionic liquid mole fraction and at all temperatures. In the range between 0.55 and 0.6 [bmpyrr][NTf 2 ] mole fraction, an ideal behaviour of the ionic liquid mixture with molecular solvent was observed for the first time. Other volumetric properties, such as isobaric thermal expansion coefficients, partial molar volumes and partial molar volumes at infinite dilution have been also calculated, in order to obtain information about interactions between GBL and selected ionic liquid. Positive values of these properties for both components also indicate weaker interactions between GBL and IL compared to the pure components. From the viscosity results, the Angell strength parameter was calculated and found to be 3.24 indicating that [bmpyrr][NTf 2 ] is a “fragile” liquid. From the volumetric and transport properties obtained, formation of the [bmpyrr] + micellar structures was also discussed. All the results are compared to those obtained for imidazolium-based ionic liquid with GBL

  14. Study of component distribution in pharmaceutical binary powder mixtures by near infrared chemical imaging

    Directory of Open Access Journals (Sweden)

    Manel Bautista

    2012-12-01

    Full Text Available Near infrared chemical imaging (NIR-CI has recently emerged as an effective technique for extracting spatial information from pharmaceutical products in an expeditious, non-destructive and non-invasive manner. These features have turned it into a useful tool for controlling various steps in drug production processes. Imaging techniques provide a vast amount of both spatial and spectral information that can be acquired in a very short time. Such a huge amount of data requires the use of efficient and fast methods to extract the relevant information. Chemometric methods have proved especially useful for this purpose. In this study, we assessed the usefulness of the correlation coefficient (CC between the spectra of samples, the pure spectra of the active pharmaceutical ingredient (API and we assessed the excipients to check for correct ingredient distribution in pharmaceutical binary preparations blended in the laboratory. Visual information about pharmaceutical component distribution can be obtained by using the CC. The performance of this model construction methodology for binary samples was compared with other various common multivariate methods including partial least squares, multivariate curve resolution and classical least squares. Based on the results, correlation coefficients are a powerful tool for the rapid assessment of correct component distribution and for quantitative analysis of pharmaceutical binary formulations. For samples of three or more components it has been shown that if the objective is only to determine uniformity of blending, then the CC image map is very good for this, and easy and fast to compute.

  15. Dielectric study of molecular association in the binary mixtures (2-ethyl-1-hexanol + alcohol) and (cyclohexane + alcohol) at 298.2 K

    Energy Technology Data Exchange (ETDEWEB)

    Ghanadzadeh, A. [Department of Chemistry, Guilan University, Rasht (Iran, Islamic Republic of)]. E-mail: aggilani@guilan.ac.ir; Ghanadzadeh, H. [Department of Chemical Engineering, Guilan University, Rasht (Iran, Islamic Republic of); Sariri, R. [Department of Chemistry, Guilan University, Rasht (Iran, Islamic Republic of); Ebrahimi, L. [Department of Chemistry, Guilan University, Rasht (Iran, Islamic Republic of)

    2005-04-15

    Experimental results of dielectric investigations of three binary mixtures (ethanol + 2-ethyl-1-hexanol), (n-butanol + 2-ethyl-1-hexanol), and (tert-butanol + 2-ethyl-1-hexanol) were reported for various mole fractions at 298.2 K. The variations of dipole moment and correlation factor, g, with mole fraction in these mixtures were investigated using a unified quasichemical method described by Durov. The molecular associations of (ethanol + cyclohexane), (n-butanol + cyclohexane), and (tert-butanol + cyclohexane) binary mixtures were also investigated using the static dielectric method. A similar trend was observed in the variation of the dipole moments with the solute mole fractions in the both binary systems (i.e., alcohol + 2-ethyl-1-hexanol and alcohol + cyclohexane)

  16. A numerical analysis of an anisotropic phase-field model for binary-fluid mixtures in the presence of magnetic-field

    OpenAIRE

    Belmiloudi , Aziz; Rasheed , Amer

    2015-01-01

    In this paper we propose a numerical scheme and perform its numerical analysis devoted to an anisotropic phase-field model with convection under the influence of magnetic field for the isother-mal solidification of binary mixtures in two-dimensional geometry. Precisely, the numerical stability and error analysis of this approximation scheme which is based on mixed finite-element method are performed. The particular application of a nickelcopper (NiCu) binary alloy, with real physical paramete...

  17. Acute toxicity of binary-metal mixtures of copper, zinc, and nickel to Pimephales promelas: Evidence of more-than-additive effect.

    Science.gov (United States)

    Lynch, Natalie R; Hoang, Tham C; O'Brien, Timothy E

    2016-02-01

    Metal mixture toxicity has been studied for decades. However, the results are not consistent, and thus ecological risk assessment and regulation of mixtures has been difficult. The objective of the present study was to use a systematic experimental design to characterize the toxicity of binary-metal mixture of Cu, Zn, and Ni to Pimephales promelas, typically to determine whether the effect of these binary-metal mixtures on P. promelas is more-than-additive. Standard 96-h toxicity tests were conducted with larval P. promelas based on US Environmental and Protection Agency methods to determine metal mixture effects. All experiments were conducted in synthetic moderately hard water with no addition of dissolved organic matter. Three different effect analysis approaches, the MixTox model, the Finney model, and the toxic unit method, were used for comparison. The results indicate that the toxicity of Cu+Zn, Cu+Ni, and Zn+Ni mixtures to P. promelas was more-than-additive. Among the 3 mixtures, the effect of the Cu+Ni mixture was the most profound. The results of the present study are useful for applications to models such as the metal mixture biotic ligand model. More research should be conducted to determine the mechanisms of acute and chronic toxicity of metal mixtures. © 2015 SETAC.

  18. Behavioral Evidence for Enhanced Processing of the Minor Component of Binary Odor Mixtures in Larval Drosophila

    Directory of Open Access Journals (Sweden)

    Yi-chun Chen

    2017-11-01

    Full Text Available A fundamental problem in deciding between mutually exclusive options is that the decision needs to be categorical although the properties of the options often differ but in grade. We developed an experimental handle to study this aspect of behavior organization. Larval Drosophila were trained such that in one set of animals odor A was rewarded, but odor B was not (A+/B, whereas a second set of animals was trained reciprocally (A/B+. We then measured the preference of the larvae either for A, or for B, or for “morphed” mixtures of A and B, that is for mixtures differing in the ratio of the two components. As expected, the larvae showed higher preference when only the previously rewarded odor was presented than when only the previously unrewarded odor was presented. For mixtures of A and B that differed in the ratio of the two components, the major component dominated preference behavior—but it dominated less than expected from a linear relationship between mixture ratio and preference behavior. This suggests that a minor component can have an enhanced impact in a mixture, relative to such a linear expectation. The current paradigm may prove useful in understanding how nervous systems generate discrete outputs in the face of inputs that differ only gradually.

  19. Phase Diagram of Binary Mixture E7:TM74A Liquid Crystals

    Directory of Open Access Journals (Sweden)

    Serafin Delica

    1999-12-01

    Full Text Available Although there are many liquid crystalline materials, difficulty is often experienced in obtaining LCs that are stable and has a wide mesophase range. In this study, mixtures of two different LCs were used to formulate a technologically viable LC operating at room temperature. Nematic E7(BDH and cholesteric TM74A were mixed at different weight ratios at 10% increments. Transition temperatures were determined via Differential Scanning Calorimetry and phase identification was done using Optical Polarizing Microscopy. The phase diagram showed the existence of three different phases for the temperature range of 10-80°C. Mixtures with 0-20% E7 exhibit only the cholesteric-nematic mesophase, which could be due to the mixture's being largely TM74A and its behavior in the temperature range considered is similar to the behavior of pure TM74A. With an increase in the concentration of E7, the smectic phase of the pure cholesteric was enhanced, as seen from the increased transition to the cholesteric-nematic phase and a broader smectic range. The cholesteric-nematic to isotropic transition increased as the nematic concentration increases, following the behavior expected from LC mixtures. For mixtures that are largely nematic (more than 50% E7, the smectic phase has vanished and the cholesteric-nematic phase dominated from 30-60°C.

  20. Separation of Binary Mixtures of Propylene and Propane by Facilitated Transport through Silver Incorporated Poly(Ether-Block-Amide Membranes

    Directory of Open Access Journals (Sweden)

    Surya Murali R.

    2015-02-01

    Full Text Available The separation of propylene and propane is a challenging task in petroleum refineries due to the similar molecular sizes and physical properties of two gases. Composite Poly(ether-block-amide (Pebax-1657 membranes incorporated with silver tetra fluoroborate (AgBF4 in concentrations of 0-50% of the polymer weight were prepared by solution casting and solvent evaporation technique. The membranes were characterized by Scanning Electron Microscopy (SEM, Fourier Transform InfraRed (FTIR and wide-angle X-ray Diffraction (XRD to study surface and cross-sectional morphologies, effect of incorporation on intermolecular interactions and degree of crystallinity, respectively. Experimental data was measured with an indigenously built high-pressure gas separation manifold having an effective membrane area of 42 cm2. Permeability and selectivity of membranes were determined for three different binary mixtures of propylene-propane at pressures varying in the range 2-6 bar. Selectivity of C3H6/C3H8 enhanced from 2.92 to 17.22 and 2.11 to 20.38 for 50/50 and 66/34 C3H6+C3H8 feed mixtures, respectively, with increasing loading of AgBF4. Pebax membranes incorporated with AgBF4 exhibit strong potential for the separation of C3H6/C3H8 mixtures in petroleum refineries.

  1. Pressure-dependent electron attachment and breakdown strengths of unitary gases, and synergism of binary gas mixtures: a relationship

    International Nuclear Information System (INIS)

    Hunter, S.R.; Christophorou, L.G.

    1984-04-01

    The relationship between the pressure-dependent electron attachment rate constants (k/sub a/) which have been observed in 1-C 3 F 6 and in several perfluoroalkanes, and the uniform field breakdown strengths (E/N)/sub lim/ in these gases is discussed. Measurements of the pressure dependence of k/sub a/ of OCS in a buffer gas of Ar are presented and the possible pressure dependence of (E/N)/sub lim/ in OCS is discussed. Uniform field breakdown measurements have been performed in C 3 F 8 , n-C 4 F 10 , and SO 2 over a range of gas pressures (3 less than or equal to P/sub T/ less than or equal to 290 kPa) and are reported. All three molecules have been found to possess pressure-dependent (E/N)/sub lim/ values. The various types of synergistic behavior which have been observed in binary gas dielectric mixtures are summarized and discussed. A new mechanism is outlined which can explain the synergism observed in several gas mixtures where the (E/N)/sub lim/ values of the mixutres are greater than those of the individual gas constituents. Model calculations are presented which support this mechanism, and can be used to explain the pressure-dependent synergistic effects which have been reported in 1-C 3 F 6 /SF 6 gas mixture

  2. Kinetically driven self-assembly of a binary solute mixture with controlled phase separation via electro-hydrodynamic flow of corona discharge

    Science.gov (United States)

    Jung, Hee Joon; Huh, June; Park, Cheolmin

    2012-09-01

    This feature article describes a new and facile process to fabricate a variety of thin films of non-volatile binary solute mixtures suitable for high performance organic electronic devices via electro-hydrodynamic flow of conventional corona discharge. Both Corona Discharge Coating (CDC) and a modified version of CDC, Scanning Corona Discharge Coating (SCDC), are based on utilizing directional electric flow, known as corona wind, of the charged uni-polar particles generated by corona discharge between a metallic needle and a bottom plate under a high electric field (5-10 kV cm-1). The electric flow rapidly spreads out the binary mixture solution on the bottom plate and subsequently forms a smooth and flat thin film in a large area within a few seconds. In the case of SCDC, the static movement of the bottom electrode on which a binary mixture solution is placed provides further control of thin film formation, giving rise to a film highly uniform over a large area. Interesting phase separation behaviors were observed including nanometer scale phase separation of a polymer-polymer binary mixture and vertical phase separation of a polymer-organic semiconductor mixture. Core-shell type phase separation of either polymer-polymer or polymer-colloidal nanoparticle binary mixtures was also developed with a periodically patterned microstructure when the relative location of the corona wind was controlled to a binary solution droplet on a substrate. We also demonstrate potential applications of thin functional films with controlled microstructures by corona coating to various organic electronic devices such as electroluminescent diodes, field effect transistors and non-volatile polymer memories.

  3. On the Origin of Microheterogeneity : A Mass Spectrometric Study of Dimethyl Sulfoxide-Water Binary Mixture

    NARCIS (Netherlands)

    Shin, Dong Nam; Wijnen, Jan W.; Engberts, Jan B.F.N.; Wakisaka, Akihiro

    2001-01-01

    We have studied the microscopic solvent structure of dimethyl sulfoxide-water mixtures and its influence on the solvation structure of solute from a clustering point of View, by means of a specially designed mass spectrometric system. It was observed that the propensity to the cluster formation is

  4. Non-linearity parameter of binary liquid mixtures at elevated pressures

    Indian Academy of Sciences (India)

    Abstract. When sound waves of high amplitude propagate, several non-linear effects occur. Ultra- sonic studies in liquid mixtures provide valuable information about structure and interaction in such systems. The present investigation comprises of theoretical evaluation of the acoustic non-linearity parameter B/A of four ...

  5. Segregation of a binary granular mixture in a vibrating sawtooth base container

    NARCIS (Netherlands)

    Mobarakabadi, Shahin; Adrang, Neda; Habibi, Mehdi; Oskoee, Ehsan Nedaaee

    2017-01-01

    Abstract.: A granular mixture of identical particles of different densities can be segregated when the system is shaken. We present an efficient method of continuously segregating a flow of randomly mixed identical spherical particles of different densities by shaking them in a

  6. Intrinsic viscosity of binary gum mixtures with xanthan gum and guar gum: Effect of NaCl, sucrose, and pH.

    Science.gov (United States)

    Bak, J H; Yoo, B

    2017-12-29

    The intrinsic viscosity ([η]) values of binary gum mixtures with xanthan gum (XG) and guar gum (GG) mixed with NaCl and sucrose at different concentrations as well as in the presence of different pH levels were examined in dilute solution as a function of XG/GG mixing ratio (100/0, 75/25, 50/50, and 0/100). Experimental values of concentration (C) and relative viscosity (η rel ) or specific viscosity (η sp ) of gums in dilute solution were fitted to five models to determine [η] values of binary gum mixtures including individual gums. A [η] model (η rel =1+[η]C) of Tanglertpaibul and Rao is recommended as the best model to estimate [η] values for the binary gum mixtures with XG and GG as affected by NaCl, sucrose, and pH. Overall, the synergistic interaction of XG-GG mixtures in the presence of NaCl and sucrose showed a greatly positive variation between measured and calculated values of [η]. In contrast, the binary gum mixtures showed synergy only under an acidic condition (pH3). These results suggest that the NaCl and sucrose addition or acidic condition appears to affect the intermolecular interaction occurred between XG and GG at different gum mixing ratios. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Mixed-symmetry localized modes and breathers in binary mixtures of Bose-Einstein condensates in optical lattices

    International Nuclear Information System (INIS)

    Cruz, H. A.; Brazhnyi, V. A.; Konotop, V. V.; Alfimov, G. L.; Salerno, M.

    2007-01-01

    We study localized modes in binary mixtures of Bose-Einstein condensates embedded in one-dimensional optical lattices. We report a diversity of asymmetric modes and investigate their dynamics. We concentrate on the cases where one of the components is dominant, i.e., has a much larger number of atoms than the other one, and where both components have the numbers of atoms of the same order but different symmetries. In the first case we propose a method of systematically obtaining the modes, considering the ''small'' component as bifurcating from the continuum spectrum. A generalization of this approach combined with the use of the symmetry of the coupled Gross-Pitaevskii equations allows for obtaining breather modes, which are also presented

  8. Predicting the vapor-liquid equilibrium of hydrocarbon binary mixtures and polymer solutions using predetermined pure component parameters

    Science.gov (United States)

    Ryu, Sang Kyu; Bae, Young Chan

    2012-05-01

    In our previous work, a new close-packed lattice model was developed for multi-component system of chain fluids with taking the chain length dependence from Monte-Carlo (MC) simulation results into account. In this work, we further extend this model to describe pressure, volume and temperature (PVT) properties, such as vapor-liquid equilibrium (VLE). To consider the effect of pressure on the phase behavior, the volume change effect is taken into account by introducing holes into the incompressible lattice model with two mixing steps. The corresponding new lattice fluid equation of state (LF-EoS) is applied to predict the thermodynamic properties of pure and binary mixtures of hydrocarbons as well as pure polymer solutions. The results of the proposed model are compared to other predictive approaches based on VLE calculations using predetermined pure model parameters without further adjustment. Thermodynamic properties predicted using the method developed in this work are consistent with the experimental data.

  9. Double diffusive unsteady convective micropolar flow past a vertical porous plate moving through binary mixture using modified Boussinesq approximation

    Directory of Open Access Journals (Sweden)

    Isaac Lare Animasaun

    2016-06-01

    Full Text Available The problem of unsteady convective with thermophoresis, chemical reaction and radiative heat transfer in a micropolar fluid flow past a vertical porous surface moving through binary mixture considering temperature dependent dynamic viscosity and constant vortex viscosity has been investigated theoretically. For proper and correct analysis of fluid flow along vertical surface with a temperature lesser than that of the free stream, Boussinesq approximation and temperature dependent viscosity model were modified and incorporated into the governing equations. The governing equations are converted to systems of ordinary differential equations by applying suitable similarity transformations and solved numerically using fourth-order Runge–Kutta method along with shooting technique. The results of the numerical solution are presented graphically and in tabular forms for different values of parameters. Velocity profile increases with temperature dependent variable fluid viscosity parameter. Increase of suction parameter corresponds to an increase in both temperature and concentration within the thin boundary layer.

  10. Mathematic model of the formation of a uniform liquid layer of binary fuel mixture inside a cryogenic target

    International Nuclear Information System (INIS)

    Wang Jinshan; Zhu Yuqun; Jiang Chao

    2006-01-01

    A mathematic model is established that formulated the relationship between the working temperature and thermal gradient in producing a uniform liquid layer of binary fuel mixture inside a cryogenic spherical shell inertial confinement fusion target. When the external linear thermal gradient was imposed on the target, the model showed the gradient of face tension induced by thermal gradient acted on the far field pull the liquid inside the ICF forward. This motion overcame the effect of gravitation to produce a uniform liquid layer inside ICF. And a finite element analysis of the heat transfer in hollow micro-sphere filled with the ICF fuel was made, the results compared with the experimental finding by K. Kim and the tendency of the thermal gradient was shown to be similar. (authors)

  11. Influence of different types of commercially available microcrystalline cellulose on degradation of perindopril erbumine and enalapril maleate in binary mixtures.

    Science.gov (United States)

    Vehovec, Tanja; Gartner, Andrej; Planinšek, Odon; Obreza, Aleš

    2012-12-01

    Influence of some commercially available types of microcrystalline cellulose (MCC) on the stability of certain active pharmaceutical ingredients (APIs), when in contact, has been investigated. Two structurally similar APIs, perindopril erbumine (PER) and enalapril maleate (EM), both well-known angiotensin-converting enzyme inhibitors were used. The main properties of an MCC that could determine the stability for each API were measured and correlated to the stability of these two APIs in binary mixtures. The stability of these APIs differed when in contact with different types of MCC. The dominant properties of MCC from one manufacturer were surface features that influenced the stability of PER and acidity that influenced the stability of EM. In the case of MCC from other manufacturers, unbound water was stability determining for both substances.

  12. SANS [small-angle neutron scattering] evaluation of the RPA [random phase approximation] theory for binary homopolymer mixtures

    International Nuclear Information System (INIS)

    Bates, F.S.; Koehler, W.C.; Wignall, G.D.; Fetters, L.J.

    1986-12-01

    A well characterized binary mixture of normal (protonated) and perdeuterated monodisperse 1,2 polybutenes has been studied by small-angle neutron scattering (SANS). For scattering wavevectors q greater than the inverse radius-of-gyration R/sub g/ -1 , the SANS intensity is quantitatively predicted by the random phase approximation (RPA) theory of deGennes over all measured values of the segment-segment interaction parameter Chi. In the region (Chi s-Chi)Chi s -1 > 0.5 the interaction parameter determined using the RPA theory for q > R/sub g/ -1 is greater than that calculated from the zero-angle intensity based on an Ornstein-Zernike plot, where Chi s represents the limit of single phase stability. These findings indicate a correlation between the critical fluctuation length ξ and R/sub g/ which is not accounted for by the RPA theory

  13. New simple spectrophotometric method for determination of the binary mixtures (atorvastatin calcium and ezetimibe; candesartan cilexetil and hydrochlorothiazide) in tablets.

    Science.gov (United States)

    Belal, Tarek S; Daabees, Hoda G; Abdel-Khalek, Magdi M; Mahrous, Mohamed S; Khamis, Mona M

    2013-04-01

    A new simple spectrophotometric method was developed for the determination of binary mixtures without prior separation. The method is based on the generation of ratio spectra of compound X by using a standard spectrum of compound Y as a divisor. The peak to trough amplitudes between two selected wavelengths in the ratio spectra are proportional to concentration of X without interference from Y . The method was demonstrated by determination of two drug combinations. The first consists of the two antihyperlipidemics: atorvastatin calcium (ATV) and ezetimibe (EZE), and the second comprises the antihypertensives: candesartan cilexetil (CAN) and hydrochlorothiazide (HCT). For mixture 1, ATV was determined using 10 μg/mL EZE as the divisor to generate the ratio spectra, and the peak to trough amplitudes between 231 and 276 nm were plotted against ATV concentration. Similarly, by using 10 μg/mL ATV as divisor, the peak to trough amplitudes between 231 and 276 nm were found proportional to EZE concentration. Calibration curves were linear in the range 2.5-40 μg/mL for both drugs. For mixture 2, divisor concentration was 7.5 μg/mL for both drugs. CAN was determined using its peak to trough amplitudes at 251 and 277 nm, while HCT was estimated using the amplitudes between 251 and 276 nm. The measured amplitudes were linearly correlated to concentration in the ranges 2.5-50 and 1-30 μg/mL for CAN and HCT, respectively. The proposed spectrophotometric method was validated and successfully applied for the assay of both drug combinations in several laboratory-prepared mixtures and commercial tablets.

  14. New simple spectrophotometric method for determination of the binary mixtures (atorvastatin calcium and ezetimibe; candesartan cilexetil and hydrochlorothiazide in tablets

    Directory of Open Access Journals (Sweden)

    Tarek S. Belal

    2013-04-01

    Full Text Available A new simple spectrophotometric method was developed for the determination of binary mixtures without prior separation. The method is based on the generation of ratio spectra of compound X by using a standard spectrum of compound Y as a divisor. The peak to trough amplitudes between two selected wavelengths in the ratio spectra are proportional to concentration of X without interference from Y. The method was demonstrated by determination of two drug combinations. The first consists of the two antihyperlipidemics: atorvastatin calcium (ATV and ezetimibe (EZE, and the second comprises the antihypertensives: candesartan cilexetil (CAN and hydrochlorothiazide (HCT. For mixture 1, ATV was determined using 10 μg/mL EZE as the divisor to generate the ratio spectra, and the peak to trough amplitudes between 231 and 276 nm were plotted against ATV concentration. Similarly, by using 10 μg/mL ATV as divisor, the peak to trough amplitudes between 231 and 276 nm were found proportional to EZE concentration. Calibration curves were linear in the range 2.5–40 μg/mL for both drugs. For mixture 2, divisor concentration was 7.5 μg/mL for both drugs. CAN was determined using its peak to trough amplitudes at 251 and 277 nm, while HCT was estimated using the amplitudes between 251 and 276 nm. The measured amplitudes were linearly correlated to concentration in the ranges 2.5–50 and 1–30 μg/mL for CAN and HCT, respectively. The proposed spectrophotometric method was validated and successfully applied for the assay of both drug combinations in several laboratory-prepared mixtures and commercial tablets. Keywords: Spectrophotometric analysis, Ratio spectra, Atorvastatin, Ezetimibe, Candesartan, Hydrochlorothiazide

  15. Perturbed-chain SAFT as a versatile tool for thermodynamic modeling of binary mixtures containing isoquinolinium ionic liquids.

    Science.gov (United States)

    Domańska, Urszula; Zawadzki, Maciej; Paduszyński, Kamil; Królikowski, Marek

    2012-07-19

    This contribution reports a recapitulation of our experimental and modeling study on thermodynamic behavior of binary systems containing N-alkylisoquinolinium ionic liquids (ILs) based on bis(trifluoromethylsulfonyl)imide anion, [CniQuin][NTf2] (n = 4,6,8). In particular, we report isothermal vapor-liquid equilibrium (VLE) phase diagrams and molar excess enthalpies of mixing (H(E)) for binary mixtures of [C8iQuin][NTf2] IL with various organic solutes including benzene, toluene, thiophene, pyridine, and butan-1-ol. The measured VLE data represented simple homozeotropic behavior with either negative or positive deviations from ideality, depending on polarity of the solute, temperature, and mole fraction of IL. In turn, the obtained data on H(E) were negative and positive for the mixtures containing aromatic hydrocarbons or thiophene and butan-1-ol, respectively, in the whole range of IL's concentration. All of the measured and some previously published data regarding phase behavior of [C8iQuin][NTf2] IL were analyzed and successfully described in terms of perturbed-chain statistical associating fluid theory (PC-SAFT). The methodology used in this work was described by us previously. In general, the proposed modeling results in VLE diagrams, which are in excellent agreement with experimental data. In the case of H(E), the results obtained are good as well but not so satisfactory such as those for VLE. Nevertheless, they seem to be very promising if one take into account the simplicity of the utilized molecular model against significant complexity of IL-based systems. Thus, we concluded that PC-SAFT equation of state can be viewed as a powerful and robust tool for modeling of systems involving ILs.

  16. Binary Mixtures of Nonyl Phenol with Alkyl Substituted Anilines as Corrosion Inhibitors for Mild Steel in Acidic Medium

    Directory of Open Access Journals (Sweden)

    H. S. Shukla

    2012-01-01

    Full Text Available The present study deals with the evaluation of the corrosion inhibition effectiveness of the two binary mixtures of nonyl phenol (NPH with 2, 4 dimethyl aniline (DMA and 2 ethyl aniline (EA at different concentration ratios (from 1:7 to 7:1 for mild steel in H2SO4 (pH=1 solution by weight loss and potentiodynamic polarization method. Corrosion inhibition ability of the compounds has been tested at different exposure periods (6 h to 24 h and at different temperatures (303 K to 333 K. The binary mixture of NPH and EA (at 7:1 concentration ratio has afforded maximum inhibition (IE% 93.5% at 6 h exposure period and at room temperature. The adsorption of both the inhibitors is found to accord with Temkin adsorption isotherm. Potentiodynamic polarization study reveals that the tested inhibitors are mixed type inhibitor and preferentially act on cathodic areas. Electrochemical impedance study suggests formation of an inhibition layer by the adsorption of the inhibitors on the metal surface. An adsorption model of the inhibitor molecules on the metal surface has been proposed after immersion test in the inhibited acid showed characteristic shift of N-H and O-H bond frequencies towards lower side compared to that of the respective pure samples which indicated the donation of electron pair through N and O atom of the inhibitor molecule in the surface adsorption phenomena. SEM study has revealed formation of semi globular inhibitor products on the metal surface. The comparisons of the protection efficiencies of these compounds according to their relative electron density on the adsorption centre and projected molecular area of the inhibitor molecules have been made.

  17. Solid–liquid equilibrium and thermodynamic research of 3-Thiophenecarboxylic acid in (water + acetic acid) binary solvent mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiang; Liang, Mengmeng [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China); Hu, Yonghong, E-mail: yonghonghu11@126.com [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China); Yang, Wenge [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China); Shi, Ying [Taiyuan Qiaoyou Chemical Industrial Co. Ltd., Taiyuan 030025 (China); Yin, Jingjing; Liu, Yan [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China)

    2014-12-20

    Highlights: • The solubility was measured in (water + acetic acid) from 283.15 to 338.15 K. • The solubility increased with increasing temperature and water contents. • The modified Apelblat equation was more accurate than the λh equation. - Abstract: In this study, the solubility of 3-thiophenecarboxylic acid was measured in (water + acetic acid) binary solvent mixtures in the temperature ranging from 283.15 to 338.15 K by the analytical stirred-flask method under atmospheric pressure. The experimental data were well-correlated with the modified Apelblat equation and the λh equation. In addition, the calculated solubilities showed good agreement with the experimental results. It was found that the modified Apelblat equation could obtain the better correlation results than the λh equation. The experiment results indicated that the solubility of 3-thiophenecarboxylic acid in the binary solvents increased with increasing temperature, increases with increasing water contents, but the increments with temperature differed from different water contents. In addition, the thermodynamic properties of the solution process, including the Gibbs energy, enthalpy, and entropy were calculated by the van’t Hoff analysis. The experimental data and model parameters would be useful for optimizing the process of purification of 3-thiophenecarboxylic acid in industry.

  18. Modelling of volumetric properties of binary and ternary mixtures by CEOS, CEOS/GE and empirical models

    Directory of Open Access Journals (Sweden)

    BOJAN D. DJORDJEVIC

    2007-12-01

    Full Text Available Although many cubic equations of state coupled with van der Waals-one fluid mixing rules including temperature dependent interaction parameters are sufficient for representing phase equilibria and excess properties (excess molar enthalpy HE, excess molar volume VE, etc., difficulties appear in the correlation and prediction of thermodynamic properties of complex mixtures at various temperature and pressure ranges. Great progress has been made by a new approach based on CEOS/GE models. This paper reviews the last six-year of progress achieved in modelling of the volumetric properties for complex binary and ternary systems of non-electrolytes by the CEOS and CEOS/GE approaches. In addition, the vdW1 and TCBT models were used to estimate the excess molar volume VE of ternary systems methanol + chloroform + benzene and 1-propanol + chloroform + benzene, as well as the corresponding binaries methanol + chloroform, chloroform + benzene, 1-propanol + chloroform and 1-propanol + benzene at 288.15–313.15 K and atmospheric pressure. Also, prediction of VE for both ternaries by empirical models (Radojković, Kohler, Jackob–Fitzner, Colinet, Tsao–Smith, Toop, Scatchard, Rastogi was performed.

  19. Variation of ratio kinetic profiles as a simple and novel spectrophotometric method for the simultaneous kinetic analysis of binary mixtures

    Directory of Open Access Journals (Sweden)

    Naseri Abdolhossein

    2012-01-01

    Full Text Available In this paper, a new and very simple kinetic - spectrophotometric method is developed for the simultaneous determination of binary mixtures without prior separational steps. The method is based on the calculation of the variation of ratio kinetic profiles. The mathematical explanation of the procedure is also illustrated. The proposed method can be used for simultaneous determination of two analytes A and B that react with the same reagent to give the same absorbing species. In order to evaluate the applicability of the method, a model data as well as an experimental data were tested. The results from experimental data relating to the simultaneous spectrophotometric determination of Co (II and V (IV based on their oxidation reactions with Fe (III in the presence 1, 10- Phenanthroline (Phen in micellar media were presented as a real model for resolution of the binary systems. The applicability of the method in tap water and synthesized alloy samples was also assessed by spiking experiments with different amount of Co (II and V (IV.

  20. Solid–liquid equilibrium and thermodynamic research of 3-Thiophenecarboxylic acid in (water + acetic acid) binary solvent mixtures

    International Nuclear Information System (INIS)

    Liu, Xiang; Liang, Mengmeng; Hu, Yonghong; Yang, Wenge; Shi, Ying; Yin, Jingjing; Liu, Yan

    2014-01-01

    Highlights: • The solubility was measured in (water + acetic acid) from 283.15 to 338.15 K. • The solubility increased with increasing temperature and water contents. • The modified Apelblat equation was more accurate than the λh equation. - Abstract: In this study, the solubility of 3-thiophenecarboxylic acid was measured in (water + acetic acid) binary solvent mixtures in the temperature ranging from 283.15 to 338.15 K by the analytical stirred-flask method under atmospheric pressure. The experimental data were well-correlated with the modified Apelblat equation and the λh equation. In addition, the calculated solubilities showed good agreement with the experimental results. It was found that the modified Apelblat equation could obtain the better correlation results than the λh equation. The experiment results indicated that the solubility of 3-thiophenecarboxylic acid in the binary solvents increased with increasing temperature, increases with increasing water contents, but the increments with temperature differed from different water contents. In addition, the thermodynamic properties of the solution process, including the Gibbs energy, enthalpy, and entropy were calculated by the van’t Hoff analysis. The experimental data and model parameters would be useful for optimizing the process of purification of 3-thiophenecarboxylic acid in industry

  1. Effective separation of propylene/propane binary mixtures by ZIF-8 membranes

    KAUST Repository

    Pan, Yichang

    2012-02-01

    The separation of propylene/propane mixtures is one of the most important but challenging processes in the petrochemical industry. A novel zeolitic imidazole framework (ZIF-8) membrane prepared by a facile hydrothermal seeded growth method showed excellent separation performances for a wide range of propylene/propane mixtures. The membrane showed a permeability of propylene up to 200. barrers and a propylene to propane separation factor up to 50 at optimal separation conditions, well surpassing the "upper-bound trade-off" lines of existing polymer and carbon membranes. The experimental data also showed that the membranes had excellent reproducibility, long-term stability and thermal stability. © 2011 Elsevier B.V.

  2. Synergistic toxicity and physiological impact of imidacloprid alone and binary mixtures with seven representative pesticides on honey bee (Apis mellifera.

    Directory of Open Access Journals (Sweden)

    Yu Cheng Zhu

    Full Text Available Imidacloprid is the most widely used insecticide in the world. In this study, we used spraying methods to simulate field exposures of bees to formulated imidacloprid (Advise® 2FL alone and binary mixtures with seven pesticides from different classes. Synergistic toxicity was detected from mixtures of Advise (58.6 mg a.i./L imidacloprid+Domark (512.5 mg a.i. /L tetraconazole, Advise+Transform (58.5 mg a.i./L sulfoxaflor, and Advise+Vydate (68 mg a.i./L oxamyl, and mortality was significantly increased by 20%, 15%, and 26% respectively. The mixtures of Advise+Bracket (88.3 mg a.i./L acephate and Advise+Karate (62.2 mg a.i./L L-cyhalothrin showed additive interaction, while Advise+Belay (9.4 mg a.i./L clothianidin and Advise+Roundup (1217.5 mg a.i./L glyphosate had no additive/synergistic interaction. Spraying bees with the mixture of all eight pesticides increased mortality to 100%, significantly higher than all other treatments. Except Bracket which significantly suppressed esterase and acetylcholinesterase (AChE activities, other treatments of Advise-only and mixtures with other pesticides did not suppress enzyme activities significantly, including invertase, glutathione S-transferase (GST, and esterase and AChE. Immunity-related phenoloxidase (PO activities in survivors tended to be more variable among treatments, but mostly still statistically similar to the control. By using specific enzyme inhibitors, we demonstrated that honey bees mainly rely on cytochrome P450 monooxygenases (P450s for detoxifying Advise, while esterases and GSTs play substantially less roles in the detoxification. This study provided valuable information for guiding pesticide selection in premixing and tank mixing in order to alleviate toxicity risk to honey bees. Our findings indicated mixtures of Advise with detoxification-enzyme-inducing pesticides may help bees to detoxify Advise, while toxicity synergists may pose further risk to bees, such as the Bracket which not

  3. Synergistic toxicity and physiological impact of imidacloprid alone and binary mixtures with seven representative pesticides on honey bee (Apis mellifera).

    Science.gov (United States)

    Zhu, Yu Cheng; Yao, Jianxiu; Adamczyk, John; Luttrell, Randall

    2017-01-01

    Imidacloprid is the most widely used insecticide in the world. In this study, we used spraying methods to simulate field exposures of bees to formulated imidacloprid (Advise® 2FL) alone and binary mixtures with seven pesticides from different classes. Synergistic toxicity was detected from mixtures of Advise (58.6 mg a.i./L imidacloprid)+Domark (512.5 mg a.i. /L tetraconazole), Advise+Transform (58.5 mg a.i./L sulfoxaflor), and Advise+Vydate (68 mg a.i./L oxamyl), and mortality was significantly increased by 20%, 15%, and 26% respectively. The mixtures of Advise+Bracket (88.3 mg a.i./L acephate) and Advise+Karate (62.2 mg a.i./L L-cyhalothrin) showed additive interaction, while Advise+Belay (9.4 mg a.i./L clothianidin) and Advise+Roundup (1217.5 mg a.i./L glyphosate) had no additive/synergistic interaction. Spraying bees with the mixture of all eight pesticides increased mortality to 100%, significantly higher than all other treatments. Except Bracket which significantly suppressed esterase and acetylcholinesterase (AChE) activities, other treatments of Advise-only and mixtures with other pesticides did not suppress enzyme activities significantly, including invertase, glutathione S-transferase (GST), and esterase and AChE. Immunity-related phenoloxidase (PO) activities in survivors tended to be more variable among treatments, but mostly still statistically similar to the control. By using specific enzyme inhibitors, we demonstrated that honey bees mainly rely on cytochrome P450 monooxygenases (P450s) for detoxifying Advise, while esterases and GSTs play substantially less roles in the detoxification. This study provided valuable information for guiding pesticide selection in premixing and tank mixing in order to alleviate toxicity risk to honey bees. Our findings indicated mixtures of Advise with detoxification-enzyme-inducing pesticides may help bees to detoxify Advise, while toxicity synergists may pose further risk to bees, such as the Bracket which not only

  4. Enhanced gel formation in binary mixtures of nanocolloids with short-range attraction

    Science.gov (United States)

    Harden, James L.; Guo, Hongyu; Bertrand, Martine; Shendruk, Tyler N.; Ramakrishnan, Subramanian; Leheny, Robert L.

    2018-01-01

    Colloidal suspensions transform between fluid and disordered solid states as parameters such as the colloid volume fraction and the strength and nature of the colloidal interactions are varied. Seemingly subtle changes in the characteristics of the colloids can markedly alter the mechanical rigidity and flow behavior of these soft composite materials. This sensitivity creates both a scientific challenge and an opportunity for designing suspensions for specific applications. In this paper, we report a novel mechanism of gel formation in mixtures of weakly attractive nanocolloids with modest size ratio. Employing a combination of x-ray photon correlation spectroscopy, rheometry, and molecular dynamics simulations, we find that gels are stable at remarkably weaker attraction in mixtures with size ratio near two than in the corresponding monodisperse suspensions. In contrast with depletion-driven gelation at larger size ratio, gel formation in the mixtures is triggered by microphase demixing of the species into dense regions of immobile smaller colloids surrounded by clusters of mobile larger colloids that is not predicted by mean-field thermodynamic considerations. These results point to a new route for tailoring nanostructured colloidal solids through judicious combination of interparticle interaction and size distribution.

  5. A combined ultrasonic flow meter and binary vapour mixture analyzer for the ATLAS silicon tracker

    CERN Document Server

    Bates, R; Berry, S; Berthoud, J; Bitadze, A; Bonneau, P; Botelho-Direito, J; Bousson, N; Boyd, G; Bozza, G; Da Riva, E; Degeorge, C; DiGirolamo, B; Doubek, M; Giugni, D; Godlewski, J; Hallewell, G; Katunin, S; Lombard, D; Mathieu, M; McMahon, S; Nagai, K; Perez-Rodriguez, E; Rossi, C; Rozanov, A; Vacek, V; Vitek, M; Zwalinski, L

    2013-01-01

    An upgrade to the ATLAS silicon tracker cooling control system may require a change from C3F8 (octafluoro-propane) evaporative coolant to a blend containing 10-25% of C2F6 (hexafluoro-ethane). Such a change will reduce the evaporation temperature to assure thermal stability following radiation damage accumulated at full LHC luminosity. Central to this upgrade is a new ultrasonic instrument in which sound transit times are continuously measured in opposite directions in flowing gas at known temperature and pressure to deduce the C3F8/C2F6 flow rate and mixture composition. The instrument and its Supervisory, Control and Data Acquisition (SCADA) software are described in this paper. Several geometries for the instrument are in use or under evaluation. An instrument with a pinched axial geometry intended for analysis and measurement of moderate flow rates has demonstrated a mixture resolution of 3.10-3 for C3F8/C2F6 molar mixtures with 20%C2F6, and a flow resolution of 2% of full scale for mass flows up to 30gs-...

  6. Solubility of Organosolv Lignin in γ-Valerolactone/Water Binary Mixtures.

    Science.gov (United States)

    Lê, Huy Quang; Zaitseva, Anna; Pokki, Juha-Pekka; Ståhl, Marina; Alopaeus, Ville; Sixta, Herbert

    2016-10-20

    The solubility of lignin in a mixture of γ-valerolactone (GVL) and water at different weight ratios was measured using the Hildebrand solubility parameters. Based on the molecular structure of lignin, its solubility parameter (δ-value) was calculated as 25.5 MPa 1/2 . The δ-value for aqueous GVL solvent increased from 23.1 MPa 1/2 for pure GVL to 45.6 MPa 1/2 for pure water. Therefore, the lignin solubility was predicted to increase with increasing GVL concentration in the aqueous mixture up to approximately 92-96 wt % of GVL. A ternary diagram describing the phase behavior of water-GVL-lignin mixtures at room temperature was constructed based on the experimental results. The three-component system exhibited a complex behavior with a liquid-liquid and solid-liquid-liquid phase split. The efficiency of the selected fractionation trials in a previous work was validated using the ternary solubility diagram. A promising recovery pathway and lignin isolation method were deduced from the results of this work. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. CO2 Frost Phenomenon for Binary System of Methane-Carbon Dioxide Mixtures

    Directory of Open Access Journals (Sweden)

    Gede Wibawa

    2015-12-01

    Full Text Available In the present study, the CO2 frost phenomenon of CH4-CO2 mixtures has been observed for the rational design of CO2 removal from natural gas using a controlled freeze out area. The CO2 frost conditions were estimated using the ZNE method and process simulation software (Aspen HYSYS® v7.3. The experiment was carried out using a double pipe heat exchanger (DPHE with the concentration of CO2 in the gas mixture at 5 and 10% and pressure of the gas mixture from 1 to 20 bar. The equilibrium temperature predictions of the ZNE method and the process simulation software only had a slight difference, with a magnitude deviation of less than 1% for pressures below 20 bar and 3% for pressures in the range of 20-30 bar, respectively. In the experimental study, CO2 frost formation was detected at pressures of 1, 5, 10 and 20 bar. The locations of the initial CO2 frost formation were determined using a pressure drop indicator associated with the predicted frost temperatures obtained from the ZNE method and the process simulation software. For all studied variables, the locations of initial CO2 frost formation were found at 0.887-1.531 m from the inlet.

  8. Thermodynamics and kinetics of binary nucleation in ideal-gas mixtures.

    Science.gov (United States)

    Alekseechkin, Nikolay V

    2015-08-07

    The nonisothermal single-component theory of droplet nucleation [N. V. Alekseechkin, Physica A 412, 186 (2014)] is extended to binary case; the droplet volume V, composition x, and temperature T are the variables of the theory. An approach based on macroscopic kinetics (in contrast to the standard microscopic model of nucleation operating with the probabilities of monomer attachment and detachment) is developed for the droplet evolution and results in the derived droplet motion equations in the space (V, x, T)—equations for V̇≡dV/dt, ẋ, and Ṫ. The work W(V, x, T) of the droplet formation is obtained in the vicinity of the saddle point as a quadratic form with diagonal matrix. Also, the problem of generalizing the single-component Kelvin equation for the equilibrium vapor pressure to binary case is solved; it is presented here as a problem of integrability of a Pfaffian equation. The equation for Ṫ is shown to be the first law of thermodynamics for the droplet, which is a consequence of Onsager's reciprocal relations and the linked-fluxes concept. As an example of ideal solution for demonstrative numerical calculations, the o-xylene-m-xylene system is employed. Both nonisothermal and enrichment effects are shown to exist; the mean steady-state overheat of droplets and their mean steady-state enrichment are calculated with the help of the 3D distribution function. Some qualitative peculiarities of the nucleation thermodynamics and kinetics in the water-sulfuric acid system are considered in the model of regular solution. It is shown that there is a small kinetic parameter in the theory due to the small amount of the acid in the vapor and, as a consequence, the nucleation process is isothermal.

  9. Thermodynamics and kinetics of binary nucleation in ideal-gas mixtures

    Science.gov (United States)

    Alekseechkin, Nikolay V.

    2015-08-01

    The nonisothermal single-component theory of droplet nucleation [N. V. Alekseechkin, Physica A 412, 186 (2014)] is extended to binary case; the droplet volume V, composition x, and temperature T are the variables of the theory. An approach based on macroscopic kinetics (in contrast to the standard microscopic model of nucleation operating with the probabilities of monomer attachment and detachment) is developed for the droplet evolution and results in the derived droplet motion equations in the space (V, x, T)—equations for V ˙ ≡ d V / d t , x ˙ , and T ˙ . The work W(V, x, T) of the droplet formation is obtained in the vicinity of the saddle point as a quadratic form with diagonal matrix. Also, the problem of generalizing the single-component Kelvin equation for the equilibrium vapor pressure to binary case is solved; it is presented here as a problem of integrability of a Pfaffian equation. The equation for T ˙ is shown to be the first law of thermodynamics for the droplet, which is a consequence of Onsager's reciprocal relations and the linked-fluxes concept. As an example of ideal solution for demonstrative numerical calculations, the o-xylene-m-xylene system is employed. Both nonisothermal and enrichment effects are shown to exist; the mean steady-state overheat of droplets and their mean steady-state enrichment are calculated with the help of the 3D distribution function. Some qualitative peculiarities of the nucleation thermodynamics and kinetics in the water-sulfuric acid system are considered in the model of regular solution. It is shown that there is a small kinetic parameter in the theory due to the small amount of the acid in the vapor and, as a consequence, the nucleation process is isothermal.

  10. Determination of phenacetin and salophen analgetics in solid binary mixtures with caffeine by infrared linear dichroic and Raman spectroscopy.

    Science.gov (United States)

    Koleva, Bojidarka B; Kolev, Tsonko M; Tsalev, Dimiter L; Spiteller, Michael

    2008-01-22

    Quantitative infrared (IR) and Raman spectroscopic approach for determination of phenacetin (Phen) and salophen (Salo) in binary solid mixtures with caffeine: phenacetin/caffeine (System 1) and salophen/caffeine (System 2) is presented. Absorbance ratios of 746 cm(-1) or 721 cm(-1) peaks (characteristic for each of determined compounds in the Systems 1 and 2) to 1509 cm(-1) and 1616 cm(-1) (attributed to Phen and Salo, respectively) were used. The IR spectroscopy gives confidence of 98.9% (System 1) and 98.3% (System 2), while the Raman spectroscopic data are with slightly higher confidence of 99.1% for both systems. The limits of detection for the compounds studied were 0.013 and 0.012 mole fraction for IR and Raman methods, respectively. Solid-state linear dichroic infrared (IR-LD) spectral analysis of solid mixtures was carried out with a view to obtaining experimental IR spectroscopic assignment of the characteristic IR bands of both determined compounds. The orientation technique as a nematic liquid crystal suspension was used, combined with the so-called reducing-difference procedure for polarized spectra interpretation. The possibility for obtaining supramolecular stereo structural information for Phen and Salo by comparing spectroscopic and crystallographic data has also been shown. An independent high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis was performed for comparison and validation of vibrational spectroscopy data. Applications to 10 tablets of commercial products APC and Sedalgin are given.

  11. Predicting the vapor–liquid equilibrium of hydrocarbon binary mixtures and polymer solutions using predetermined pure component parameters

    International Nuclear Information System (INIS)

    Ryu, Sang Kyu; Bae, Young Chan

    2012-01-01

    Highlights: ► We have developed a close-packed lattice model for chain-like molecules. ► The chain length dependence determined from Monte-Carlo simulation results were used. ► To consider the volume effect, hole theory and two mixing steps were used. ► A lattice fluid equation of state (LF-EoS) is presented for VLE of hydrocarbon mixtures. ► Correlation of pure polymer solutions data with use of the LF-EoS. - Abstract: In our previous work, a new close-packed lattice model was developed for multi-component system of chain fluids with taking the chain length dependence from Monte-Carlo (MC) simulation results into account. In this work, we further extend this model to describe pressure, volume and temperature (PVT) properties, such as vapor–liquid equilibrium (VLE). To consider the effect of pressure on the phase behavior, the volume change effect is taken into account by introducing holes into the incompressible lattice model with two mixing steps. The corresponding new lattice fluid equation of state (LF-EoS) is applied to predict the thermodynamic properties of pure and binary mixtures of hydrocarbons as well as pure polymer solutions. The results of the proposed model are compared to other predictive approaches based on VLE calculations using predetermined pure model parameters without further adjustment. Thermodynamic properties predicted using the method developed in this work are consistent with the experimental data.

  12. Custom real-time ultrasonic instrumentation for simultaneous mixture and flow analysis of binary gases in the CERN ATLAS experiment

    CERN Document Server

    Alhroob, M.; Berry, S.; Bitadze, A.; Bonneau, P.; Boyd, G.; Crespo-Lopez, O.; Degeorge, C.; Deterre, C.; Di Girolamo, B.; Doubek, M.; Favre, G.; Hallewell, G.; Hasib, A.; Katunin, S.; Lombard, D.; Madsen, A.; McMahon, S.; Nagai, K.; O'Rourke, A.; Pearson, B.; Robinson, D.; Rossi, C.; Rozanov, A.; Stanecka, E.; Strauss, M.; Vacek, V.; Vaglio, R.; Young, J.; Zwalinski, L.

    2016-01-01

    Custom ultrasonic instruments have been developed for simultaneous monitoring of binary gas mixture and flow in the ATLAS Inner Detector. Sound transit times are measured in opposite directions in flowing gas. Flow rate and sound velocity are respectively calculated from their difference and average. Gas composition is evaluated in real-time by comparison with a sound velocity/composition database, based on the direct dependence of sound velocity on component concentrations in a mixture at known temperature and pressure. Five devices are integrated into the ATLAS Detector Control System. Three instruments monitor coolant leaks into N2 envelopes of the silicon microstrip and Pixel detectors. Resolutions better than ±2×10−5±2×10−5 and ±2×10−4±2×10−4 are seen for C3F8 and CO2 leak concentrations in N2 respectively. A fourth instrument detects sub-percent levels of air ingress into the C3F8 condenser of the new thermosiphon coolant recirculator. Following extensive studies a fifth instrument was b...

  13. The solid-liquid phase diagrams of binary mixtures of even saturated fatty acids differing by six carbon atoms

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Mariana C. [LPT, Department of Chemical Process, School of Chemical Engineering, University of Campinas, UNICAMP, P.O. Box 6066, 13083-970, Campinas-SP (Brazil); EXTRAE, Department of Food Engineering, Faculty of Food Engineering, University of Campinas, UNICAMP, P.O. Box 6121, 13083-862, Campinas-SP (Brazil); CICECO, Departamento de Quimica da Universidade de Aveiro, 3810-193 Aveiro (Portugal); Rolemberg, Marlus P. [DETQI, Department of Chemical Technology, Federal University of Maranhao (UFMA), Sao Luis, Maranhao (Brazil); Meirelles, Antonio J.A. [EXTRAE, Department of Food Engineering, Faculty of Food Engineering, University of Campinas, UNICAMP, P.O. Box 6121, 13083-862, Campinas-SP (Brazil); Coutinho, Joao A.P. [CICECO, Departamento de Quimica da Universidade de Aveiro, 3810-193 Aveiro (Portugal); Kraehenbuehl, M.A., E-mail: mak@feq.unicamp.br [LPT, Department of Chemical Process, School of Chemical Engineering, University of Campinas, UNICAMP, P.O. Box 6066, 13083-970, Campinas-SP (Brazil)

    2009-12-10

    This study was aimed at using the solid-liquid phase diagrams for three binary mixtures of saturated fatty acids, especially the phase transitions below the liquidus line. These mixtures are compounded by caprylic acid (C{sub 8:0}) + myristic acid (C{sub 14:0}), capric acid (C{sub 10:0}) + palmitic acid (C{sub 16:0}), lauric acid (C{sub 12:0}) + stearic acid (C{sub 18:0}), differing by six carbon atoms between carbon chains. The phase diagrams were obtained by differential scanning calorimetry (DSC). The polarized light microscopy was used to complement the characterization for a full grasp of the phase diagram. Not only do these phase diagrams present peritectic and eutectic reactions, but also metatectic reactions, due to solid-solid phase transitions common, in fatty acids. These findings have contributed to the elucidation of the phase behavior of these important biochemical molecules with implications in various industrial production.

  14. Generalization and discrimination tasks yield concordant measures of perceived distance between odours and their binary mixtures in larval Drosophila.

    Science.gov (United States)

    Chen, Yi-chun; Gerber, Bertram

    2014-06-15

    Similarity between odours is notoriously difficult to measure. Widely used behavioural approaches in insect olfaction research are cross-adaptation, masking, as well as associative tasks based on olfactory learning and the subsequent testing for how specific the established memory is. A concern with such memory-based approaches is that the learning process required to establish an odour memory may alter the way the odour is processed, such that measures of perception taken at the test are distorted. The present study was therefore designed to see whether behavioural judgements of perceptual distance are different for two different memory-based tasks, namely generalization and discrimination. We used odour-reward learning in larval Drosophila as a study case. In order to challenge the larvae's olfactory system, we chose to work with binary mixtures and their elements (1-octanol, n-amyl acetate, 3-octanol, benzaldehyde and hexyl acetate). We determined the perceptual distance between each mixture and its elements, first in a generalization task, and then in a discrimination task. It turns out that scores of perceptual distance are correlated between both tasks. A re-analysis of published studies looking at element-to-element perceptual distances in larval reward learning and in adult punishment learning confirms this result. We therefore suggest that across a given set of olfactory stimuli, associative training does not grossly alter the pattern of perceptual distances. © 2014. Published by The Company of Biologists Ltd.

  15. Evaluation of the performance of thermal diffusion column separating binary gas mixtures with continuous draw-off

    International Nuclear Information System (INIS)

    Kitamoto, Asashi; Shimizu, Masami; Takashima, Yoichi

    1977-01-01

    Advanced transport relations involving three column constants, H sup(σ), K sub(c)sup(σ) and K sub(d)sup(σ), are developed to describe the separation performance of a thermal diffusion column with continuous draw-off. These constants were related to some integral functions of velocity profile, temperature distribution, density of gas mixture and characteristic values of transport coefficients. The separation of binary gas mixture by this technique was so effective that three reasonable factors had to be introduced into the column constants in the theory. They are a circulation constant of natural convection, a definition of characteristic mean temperature and a definition of mean composition over the column. The separation performance and the column constants also varied with the distortion of velocity profile due to continuous draw-off from the top or the bottom of column. However, its effect was not large, compared with the other factors mentioned above. The theory presented here makes possible to estimate the separation performance of hot-wire type thermal diffusion column with high accuracy. (auth.)

  16. Separation of species of a binary fluid mixture confined in a channel in presence of a strong transverse magnetic field

    Directory of Open Access Journals (Sweden)

    Sharma Bishwaram

    2012-01-01

    Full Text Available Effects of a transverse magnetic field on separation of a binary mixture of incompressible viscous thermally and electrically conducting fluids confined between two stationary parallel plates are examined. Both the plates are maintained at constant temperatures. It is assumed that one of the components, which is rarer and lighter, is present in the mixture in a very small quantity. The equations governing the motion, temperature and concentration in Cartesian coordinate are solved analytically. The solution obtained for concentration distribution is plotted against the width of the channel for various values of non-dimensional parameters. It is found that the effect of transverse magnetic field is to separate the species of rarer and lighter component by contributing its effect directly to the temperature gradient and the pressure gradient. The effects of increase in the values of Hartmann number, magnetic Reynolds number, barodiffusion number, thermal diffusion number, electric field parameter and the product of Prandtl number and Eckert number are to collect the rarer and lighter component near the upper plate and throw away the heavier component towards the lower plate. The problem discussed here derives its application in the basic fluid dynamics separation processes to separate the rare component of the different isotopes of heavier molecules where electromagnetic method of separation does not work.

  17. Ultrasonic velocity and absorption study of binary mixtures of cyclohexane with acrylonitrile by interferometric method at different frequencies

    Science.gov (United States)

    Pawar, N. R.; Chimankar, O. P.; Bhandakkar, V. D.; Padole, N. N.

    2012-12-01

    The ultrasonic velocity (u), absorption (α), density (ρ), and viscosity (η) has been measured at different frequencies (1MHz to 10MHz) in the binary mixtures of cyclohexane with acrylonitriile over the entire range of composition at temperature 303K. Vander Waal's constant (b), adiabatic compressibility (βa), acoustic impedance (Z), molar volume (V), free length (Lf), free volume, internal pressure, intermolecular radius and relative association have been also calculated. A special application for acrylonitrile is in the manufacture of carbon fibers. These are produced by paralysis of oriented poly acrylonitrile fibers and are used to reinforce composites for high-performance applications in the aircraft, defense and aerospace industries. Other applications of acrylonitrile are in the production of fatty amines, ion exchange resins and fatty amine amides used in cosmetics, adhesives, corrosion inhibitors and water-treatment resins. Cyclohexane derivatives can be used for the synthesis of pharmaceuticals, dyes, herbicides, plant growth regulator, plasticizers, rubber chemicals, nylon, cyclamens and other organic compounds. In the view of these extensive applications of acrylonitrile and cyclohexane in the engineering process, textile and pharmaceutical industries present study provides qualitative information regarding the nature and strength of interaction in the liquid mixtures through derive parameters from ultrasonic velocity and absorption measurement.

  18. Esterification of microcrystalline cellulose by binary mixture of pyromellitic dianhydride and boric acid

    International Nuclear Information System (INIS)

    Arslanov, Sh.S.; Petropavlovskij, G.A.

    1996-01-01

    The reaction between microcrystalline cellulose and boric acid in the medium of dimethyl-sulfoxide (DMSO) and in solid phase has been studied. By the methods of IR and 1 H NMR spectroscopy it has been shown that the triatment of cellulose with boric acid solution in DMSO, while the latter is removed under vacuum conditions and cellulose is heated up to 170 deg C, gives rise to formation of unstable esters of cellulose and boric acid. Pyromellitate-borates of cellulose are formed in the course of cellulose reaction with a mixture of boric acid and pyromellite dianhydride. 9 refs., 3 figs., 1 tab

  19. Pattern formation in binary fluid mixtures induced by short-range competing interactions.

    Science.gov (United States)

    Bores, Cecilia; Lomba, Enrique; Perera, Aurélien; Almarza, Noé G

    2015-08-28

    Molecular dynamics simulations and integral equation calculations of a simple equimolar mixture of diatomic molecules and monomers interacting via attractive and repulsive short-range potentials show the existence of pattern formation (microheterogeneity), mostly due to depletion forces away from the demixing region. Effective site-site potentials extracted from the pair correlation functions using an inverse Monte Carlo approach and an integral equation inversion procedure exhibit the features characteristic of a short-range attractive and a long-range repulsive potential. When charges are incorporated into the model, this becomes a coarse grained representation of a room temperature ionic liquid, and as expected, intermediate range order becomes more pronounced and stable.

  20. Tilt Angle and the Temperature Shifts Calculated as a Function of Concentration for the AC* Phase Transition in a Binary Mixture of Liquid Crystals

    Science.gov (United States)

    Yurtseven, H.; Kurt, M.

    We study here the tilt angle and the temperature shifts as a function of concentration for the AC* phase transition in a binary mixture, using our mean field model with the biquadratic P2θ2 coupling — and also with the bilinear Pθ and P2θ2 couplings. By expanding the free energy in terms of the tilt angle and polarization, the tilt angle and the temperature shift are evaluated by using the coefficients given in the free energy expansion. By employing a concentration-dependent coefficient, the tilt angle and the temperature shift are calculated as a function of concentration of 10.O.4 for the SmAC* transition in a binary mixture of C7 and 10.O.4. Our calculated values of the tilt angle and the temperature shifts decrease as the concentration of 10.O.4 increases, as confirmed experimentally for the AC* transition in this binary mixture. This indicates that our mean field models studied here are satisfactory to explain the observed behavior of the AC* transition of the binary mixture of C7 and 10.O.4.

  1. Acoustic, volumetric and osmotic properties of binary mixtures containing the ionic liquid 1-butyl-3-methylimidazolium dicyanamide mixed with primary and secondary alcohols

    International Nuclear Information System (INIS)

    Calvar, Noelia; González, Emilio J.; Domínguez, Ángeles; Macedo, Eugénia A.

    2012-01-01

    Highlights: ► Physical and osmotic properties of binary mixtures {alcohol + [BMim][dca]} were measured. ► From experimental data, apparent molar properties and osmotic coefficients were calculated. ► The apparent properties were fitted using a Redlich–Meyer type equation. ► The osmotic coefficients were correlated using the Extended Pitzer and the MNRTL models. - Abstract: In this paper, densities and speeds of sound for five binary systems {alcohol + 1-butyl-3-methylimidazolium dicyanamide} were measured from T = (293.15 to 323.15) K and atmospheric pressure. From these experimental data, apparent molar volume and apparent molar isentropic compression have been calculated and fitted to a Redlich–Meyer type equation. This fit was also used to calculate the apparent molar volume and apparent molar isentropic compression at infinite dilution for the studied binary mixtures. Moreover, the osmotic and activity coefficients and vapor pressures of these binary mixtures were also determined at T = 323.15 K using the vapor pressure osmometry technique. The experimental osmotic coefficients were correlated using the Extended Pitzer model of Archer. The mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures were calculated from the parameters obtained in the correlation.

  2. Long-term effects of a binary mixture of perfluorooctane sulfonate (PFOS) and bisphenol A (BPA) in zebrafish (Danio rerio).

    Science.gov (United States)

    Keiter, Su; Baumann, L; Färber, H; Holbech, H; Skutlarek, D; Engwall, M; Braunbeck, T

    2012-08-15

    Previous in vitro studies have reported the potential of perfluorooctane sulfonate (PFOS) to increase the toxicity of other compounds. Given the complex nature of mixtures of environmental pollutants in aquatic systems together with the persistent and bioaccumulative properties of PFOS, this study aimed at evaluating the long-term effects and toxicity-increasing behavior of PFOS in vivo using the zebrafish (Danio rerio). Fish were maintained in flow-through conditions and exposed to single and binary mixtures of PFOS and the endocrine disruptor bisphenol A (BPA) at nominal concentrations of 0.6, 100 and 300 μg/L and 10, 200 and 400 μg/L, respectively. F1 and F2 generations were evaluated from 0 to 180 days post-fertilization (dpf) and F3 generation was evaluated from 0 to 14 dpf. Survival was documented in all generations, whereas growth, fecundity, fertilization rate, histological alterations (in liver, thyroid and gonads) and vitellogenin (Vtg) induction in males were evaluated for F1 and F2 generations. Data for growth were collected at 30, 90 and 180 dpf and data for histological evaluations and Vtg induction were analyzed at 90 and 180 dpf. No significant effects on survival were seen in the F1 generation in any treatment following 180 d exposure; however, in the F2 generation, 300 μg/L PFOS both alone and in combination with BPA (10, 200 and 400 μg/L) induced 100% mortality within 14 dpf. PFOS (0.6 and 300 μg/L) did not increase the Vtg-inducing potential of BPA (10, 200 and 400 μg/L) in a binary mixture. In contrast, binary mixtures with 300 μg/L PFOS suppressed the Vtg levels in F1 males at 90 dpf when compared to single BPA exposures. Whereas the lowest tested PFOS concentration (0.6 μg/L) showed an estrogenic potential in terms of significant Vtg induction, Vtg levels were generally found to decrease with increasing PFOS-exposure in both F1 and F2 generations. In F1 generation, BPA-exposure was found to increase Vtg levels in a concentration

  3. Ecotoxicological evaluation of propranolol hydrochloride and losartan potassium to Lemna minor L. (1753) individually and in binary mixtures.

    Science.gov (United States)

    Godoy, Aline A; Kummrow, Fábio; Pamplin, Paulo Augusto Z

    2015-07-01

    Antihypertensive pharmaceuticals, including the beta-blockers, are one of the most detected therapeutic classes in the environment. The ecotoxicity of propranolol hydrochloride and losartan potassium was evaluated, both individually and combined in a binary mixture, by using the Lemna minor growth inhibition test. The endpoints evaluated in the single-pharmaceutical tests were frond number, total frond area and fresh weight. For the evaluation of the mixture toxicity, the selected endpoint was frond number. Water quality criteria values (WQC) were derived for the protection of freshwater and saltwater pelagic communities regarding the effects induced by propranolol and losartan using ecotoxicological data from the literature, including our data. The risks associated with both pharmaceutical effects on non-target organisms were quantified through the measured environmental concentration (MEC)/predicted-no-effect concentration (PNEC) ratios. For propranolol, the total frond area was the most sensitive endpoint (EC50 = 77.3 mg L(-1)), while for losartan there was no statistically significant difference between the endpoints. Losartan is only slightly more toxic than propranolol. Both concentration addition and independent action models overestimated the mixture toxicity of the pharmaceuticals at all the effect concentration levels evaluated. The joint action of both pharmaceuticals showed an antagonistic interaction to L. minor. Derived WQC assumed lower values for propranolol than for losartan. The MEC/PNEC ratios showed that propranolol may pose a risk for the most sensitive aquatic species, while acceptable risks posed by losartan were estimated for most of aquatic matrices. To the authors knowledge these are the first data about losartan toxicity for L. minor.

  4. Formation of H2-He substellar bodies in cold conditions. Gravitational stability of binary mixtures in a phase transition

    Science.gov (United States)

    Füglistaler, A.; Pfenniger, D.

    2016-06-01

    Context. Molecular clouds typically consist of 3/4 H2, 1/4 He and traces of heavier elements. In an earlier work we showed that at very low temperatures and high densities, H2 can be in a phase transition leading to the formation of ice clumps as large as comets or even planets. However, He has very different chemical properties and no phase transition is expected before H2 in dense interstellar medium conditions. The gravitational stability of fluid mixtures has been studied before, but these studies did not include a phase transition. Aims: We study the gravitational stability of binary fluid mixtures with special emphasis on when one component is in a phase transition. The numerical results are aimed at applications in molecular cloud conditions, but the theoretical results are more general. Methods: First, we study the gravitational stability of van der Waals fluid mixtures using linearized analysis and examine virial equilibrium conditions using the Lennard-Jones intermolecular potential. Then, combining the Lennard-Jones and gravitational potentials, the non-linear dynamics of fluid mixtures are studied via computer simulations using the molecular dynamics code LAMMPS. Results: Along with the classical, ideal-gas Jeans instability criterion, a fluid mixture is always gravitationally unstable if it is in a phase transition because compression does not increase pressure. However, the condensed phase fraction increases. In unstable situations the species can separate: in some conditions He precipitates faster than H2, while in other conditions the converse occurs. Also, for an initial gas phase collapse the geometry is essential. Contrary to spherical or filamentary collapses, sheet-like collapses starting below 15 K easily reach H2 condensation conditions because then they are fastest and both the increase of heating and opacity are limited. Conclusions: Depending on density, temperature and mass, either rocky H2 planetoids, or gaseous He planetoids form. H2

  5. Measurement of critical temperatures and critical pressures for binary mixtures of methyl tert-butyl ether (MTBE) + alcohol and MTBE + alkane

    International Nuclear Information System (INIS)

    Han, Kewei; Xia, Shuqian; Ma, Peisheng; Yan, Fangyou; Liu, Tao

    2013-01-01

    Highlights: • The critical properties of seven binary mixtures related to gasoline were measured. • The critical properties of the five systems containing MTBE were reported for the first time. • Binary interaction parameters were fitted by experimental data using PR EOS with Wong–Sandler mixing rule. • Redlich–Kister equation was used to correlate the experimental data. -- Abstract: A set of high-pressure view apparatus was designed for determining the critical properties of chemicals. In order to check the reliability of the apparatus, the critical temperatures (T c ) and critical pressures (P c ) of pure n-heptane, cyclohexane, methanol, ethanol, 1-propanol, methyl tert-butyl ether (MTBE), and binary mixture n-hexane + ethanol were measured. The experimental data were in good agreement with the literature data, which proves the reliability of the apparatus used in the work. The critical temperatures and critical pressures of five binary mixtures containing gasoline additive (MTBE + n-heptane, MTBE + cyclohexane, MTBE + methanol, MTBE + ethanol, MTBE + 1-propanol) were measured using the high-pressure view cell with visual observation. The critical temperatures and critical pressures for the five binary mixtures were all reported for the first time. In addition, the critical temperatures and critical pressures of the binary mixture n-heptane + cyclohexane (two of main components in gasoline) were also measured. All the critical lines for the mixtures studied are continuous which connect the critical points of the two pure components, indicating their phase diagrams belong to type I proposed by Scott and van Konynenburg. The critical points of these systems were calculated by the Peng–Robinson equation of state with the Wong–Sandler mixing rule. This model could calculate the critical properties of the mixtures well with the binary interaction parameter k ij obtained by fitting the experimental critical data. And the experimental data were all

  6. Ion-molecule reactions in the binary mixture of ethylene oxide and trioxane, 1

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Sugiura, Toshio.

    1977-01-01

    The formation mechanism of protonated molecular ions by cross-reactions in ethylene oxide-trioxane mixtures has been studied with use of a modified time-of-flight mass spectrometer. The precursors of the product ions were determined by analysis of the fine structure of their ionization efficiency curves using deuterated ethylene oxide. Protonated ethylene oxide is formed by the hydrogen atom transfer reaction of ethylene oxide molecular ion with trioxane, and protonated trioxane by the proton transfer reaction of CHO + (from ethylene oxide) with trioxane. In the ion-molecule reactions of ethylene-d 4 oxide-trioxane mixtures, appreciable isotope effect was observed. The CHO + from ethylene oxide is an important reactant ion as compared with that from trioxane in the proton transfer reaction, and CHO + from ethylene oxide was suggested as a thermal reactive ion. The order of proton affinity could be estimated from the proton transfer reactions involving CHO + . It was found that the proton affinity of trioxane is smaller than that of ethylene oxide. (auth.)

  7. CWIS Experiment On Board REXUS-16 Sounding Rocket: Investigation of the Chemical Wave in Binary Mixture

    Science.gov (United States)

    Tzevelecos, W.; Pugliese, A.; de Filippis, L.; Manzone, S.; Alfano, B.; Mancino, F.; Runge, W.; Desenfans, O.; Galand, Q.; Van Vaerenbergh, S.

    2015-09-01

    Chemical Wave in Soret Effect (CWIS) is an experiment launched in May 2014 on-board a REXUS sounding rocket from Esrange Space Center. The experiment was completely designed and assembled by students from different countries under an international collaboration between the Université libre de Bruxelles (ULB) and the University of Naples Federico II. This student program called REXUS/BEXUS allows students to perform experiments in space science applications under the supervision of the European Space Agency (ESA). The objective of the CWIS Team was to visualize the Chemical Wave (CW) during the transient of the Soret effect. The CW is a concentration front that rapidly propagates under thermal gradient in a liquid mixture, and which marks the beginning of the chemical separation phenomenon by thermodiffusion (the separation process is itself named Soret effect, but is usually analyzed statically). The selected mixture was a solution of Ethylene Glycol in Water and concentration variation due to thermal gradients was recorded using a modified Fizeau interferometer, with modifications designed to enlarge a very small region of the test cell using cylindrical squeezing. We recorded more than 100 images with the chemical information and in this paper work we will show the final results of the sounding rocket experiment.

  8. Excess Thermodynamic Properties and Ftir Spectroscopy of Aceton-Isopropanol Liquid Binary Mixture

    Directory of Open Access Journals (Sweden)

    Ali A. Jazie

    2018-01-01

    Full Text Available Experimental investigation was done using different instruments for the testing the properties of density, surface tension and viscosity in the case of pure and mixture system at the normal temperature of 25 oC and 1 atm. Excess volume was found to exhibit negative value at a mole fraction of 0.5. The deviation in the surface tension and viscosity were found of a positive value at the mole fraction value of 0.5. The experimental excess properties were correlated using the Redlich-Kister (RK equation and showed an accepted standard deviation. The intermolecular interaction between acetone and isopropanol was found of negligible effect and showed a weakness in the hydrogen bonding according to the FTIR spectra for the mixture of acetone and isopropanol which agreed with the positive values of excess molar volume. Moreover, the values of surface tension and viscosity deviations were found of negative values for all the mole fraction range studied.     

  9. Vapour pressures and osmotic coefficients of binary mixtures containing alcohol and pyrrolidinium-based ionic liquids

    International Nuclear Information System (INIS)

    Calvar, N.; Domínguez, Á.; Macedo, E.A.

    2013-01-01

    Highlights: • Osmotic coefficients of alcohols with pyrrolidinium ILs are determined. • Experimental data were correlated with extended Pitzer model of Archer and MNRTL. • Mean molal activity coefficients and excess Gibbs free energies were calculated. • The results have been interpreted in terms of interactions. -- Abstract: The osmotic and activity coefficients and vapour pressures of mixtures containing primary (1-propanol, 1-butanol and 1-pentanol) and secondary (2-propanol and 2-butanol) alcohols with pyrrolidinium-based ionic liquids (1-butyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide, C 4 MpyrNTf 2 , and 1-butyl-1-methyl pyrrolidinium trifluoromethanesulfonate, C 4 MpyrTFO) have been experimentally determined at T = 323.15 K. For the experimental measurements, the vapour pressure osmometry technique has been used. The results on the influence of the structure of the alcohol and of the anion of the ionic liquid on the determined properties have been discussed and compared with literature data. For the correlation of the osmotic coefficients obtained, the Extended Pitzer model of Archer and the Modified Non-Random Two Liquids model were applied. The mean molal activity coefficients and the excess Gibbs energy for the studied mixtures were calculated from the parameters obtained in the correlation

  10. Two-dimensional Turbulence in Symmetric Binary-Fluid Mixtures: Coarsening Arrest by the Inverse Cascade.

    Science.gov (United States)

    Perlekar, Prasad; Pal, Nairita; Pandit, Rahul

    2017-03-21

    We study two-dimensional (2D) binary-fluid turbulence by carrying out an extensive direct numerical simulation (DNS) of the forced, statistically steady turbulence in the coupled Cahn-Hilliard and Navier-Stokes equations. In the absence of any coupling, we choose parameters that lead (a) to spinodal decomposition and domain growth, which is characterized by the spatiotemporal evolution of the Cahn-Hilliard order parameter ϕ, and (b) the formation of an inverse-energy-cascade regime in the energy spectrum E(k), in which energy cascades towards wave numbers k that are smaller than the energy-injection scale kin j in the turbulent fluid. We show that the Cahn-Hilliard-Navier-Stokes coupling leads to an arrest of phase separation at a length scale Lc, which we evaluate from S(k), the spectrum of the fluctuations of ϕ. We demonstrate that (a) Lc ~ LH, the Hinze scale that follows from balancing inertial and interfacial-tension forces, and (b) Lc is independent, within error bars, of the diffusivity D. We elucidate how this coupling modifies E(k) by blocking the inverse energy cascade at a wavenumber kc, which we show is ≃2π/Lc. We compare our work with earlier studies of this problem.

  11. Thermodynamic characterization of bio-fuels: Excess functions for binary mixtures containing ETBE and hydrocarbons

    International Nuclear Information System (INIS)

    Segovia, Jose J.; Villamanan, Rosa M.; Martin, M. Carmen; Chamorro, Cesar R.; Villamanan, Miguel A.

    2010-01-01

    European energy policy is promoting the use of bio-fuels for transportation. Bioethers and bioalcohols are used as blending agents for enhancing the octane number. They make gasoline work harder, help the engine last longer and reduce air pollution. They also cause changes in the fuel properties. Development of renewable fuels needs both knowledge of new thermodynamic data and improvement of clean energy technologies. In this context, the use of ethanol of vegetable origin in its manufacture process, increases the interest of ETBE or bio-ETBE as an oxygenated additive. A complete study of the behaviour of ETBE + hydrocarbons mixtures is presented. Some experimental data concerning vapor-liquid equilibria and heats of mixing were determined in our laboratory. All the techniques have a high accuracy. The data were reduced by well-known models, such as NRTL and used to model the thermodynamic properties.

  12. Segregation of a binary granular mixture in a vibrating sawtooth base container.

    Science.gov (United States)

    Mobarakabadi, Shahin; Adrang, Neda; Habibi, Mehdi; Oskoee, Ehsan Nedaaee

    2017-09-01

    A granular mixture of identical particles of different densities can be segregated when the system is shaken. We present an efficient method of continuously segregating a flow of randomly mixed identical spherical particles of different densities by shaking them in a quasi-two-dimensional container with a sawtooth-shaped base. Using numerical simulation we study the effect of direction of shaking (horizontal/vertical), geometry of the sawtooth, and the friction coefficient between the grains and the container walls on the segregation quality. Finally by performing experiments on the same system we compare our simulation results with the experimental results. The good agreement between our simulation and experiment indicates the validity of our simulation approach and will provide a practical way for granular segregation in industrial applications.

  13. Applicability of airlift draft-tube fluidized bioreactors for binary protein mixture bioseparation.

    Science.gov (United States)

    Dahman, Yaser; Margaritis, Argyrios

    2008-06-01

    An airlift draft-tube fluidized bioreactor has been designed and tested for applications in protein bioseparation. Operating parameters and geometrical dimensions of the bioreactor were optimized to ensure fluid circulation in a defined cyclic pattern between the riser and the downcomer. The overall directionality of liquid flow generates homogeneous field of low shear and achieves good mixing efficiency. Bioseparation of proteins was achieved from solutions containing both BSA and BHb at different initial concentrations and at pH 7. Similar adsorption capacities of both proteins were observed in single protein adsorption experiments at pH 7. Compressibility of BHb allowed for high adsorption capacity, in addition to the hydrophobic interaction forces. Apparently the homogeneous and lower shear generated by the airlift bioreactor reduces the compressibility of adsorbed BHb. This allowed for higher BSA adsorption from solutions containing BSA and BHb mixtures. Conventional batch adsorption experiments showed more adsorption of BHb, which reduces bioseparation efficiency.

  14. Scaling function of critical binary mixtures: Nitrobenzene- n-hexane data revisited

    Science.gov (United States)

    Mirzaev, Sirojiddin Z.; Kaatze, Udo

    2012-01-01

    Ultrasonic attenuation spectra of the nitrobenzene- n-hexane mixture of critical composition have been analysed. Data between 50 kHz and 1 GHz from different sources have been included to show that at a given temperature the spectra, in addition to the critical contribution, reveal a non-critical relaxation term. Taking this additional term into account inconsistencies in the scaling function reported in the literature are avoided. In the final analysis the scaling function of the nitrobenzene- n-hexane system follows the predictions of the Bhattacharjee-Ferrell theory with critical amplitude and relaxation rate of concentration fluctuations in nice agreement with determinations from independent methods. The low-frequency attenuation data are briefly discussed with a view to a bulk viscosity approach which yields a slightly different proportionality constant in the linear regime of the scaling function than the Bhattacharjee-Ferrell theory. Evidence in favour of the latter is obtained.

  15. Selective micellar electrokinetic chromatographic method for simultaneous determination of some pharmaceutical binary mixtures containing non-steroidal anti-inflammatory drugs

    Directory of Open Access Journals (Sweden)

    Michael E. El-Kommos

    2013-02-01

    Full Text Available A simple and selective micellar electrokinetic chromatographic (MEKC method has been developed for the analysis of five pharmaceutical binary mixtures containing three non-steroidal anti-inflammatory drugs (NSAIDs. The investigated mixtures were Ibuprofen (IP–Paracetamol (PC, Ibuprofen (IP–Chlorzoxazone (CZ, Ibuprofen (IP–Methocarbamol (MC, Ketoprofen (KP–Chlorzoxazone (CZ and Diclofenac sodium (DS–Lidocaine hydrochloride (LC. The separation was run for all mixtures using borate buffer (20 mM, pH 9 containing 15% (v/v methanol and 100 mM sodium dodecyl sulphate (SDS at 15 kV and the components were detected at 214 nm. Different factors affecting the electrophoretic mobility of the seven investigated drugs were studied and optimized. The method was validated according to international conference of harmonization (ICH guidelines and United States pharmacopoeia (USP. The method was applied to the analysis of five pharmaceutical binary mixtures in their dosage forms. The results were compared with other reported high performance liquid chromatographic methods and no significant differences were observed. Keywords: Capillary electrophoresis, Micellar electrokinetic chromatographic method, Non-steroidal anti-inflammatory drugs, Pharmaceutical binary mixtures, Pharmaceutical analysis

  16. Computer simulations of adsorption and diffusion for binary mixtures of methane and hydrogen in titanosilicates

    Science.gov (United States)

    Mitchell, Martha C.; Gallo, Marco; Nenoff, Tina M.

    2004-07-01

    Equilibrium molecular dynamics (MD) simulations of equimolar mixtures of hydrogen and methane were performed in three different titanosilicates: naturally occurring zorite and two synthetic titanosilicates, ETS-4 and ETS-10. In addition, single-component MD simulations and adsorption isotherms generated using grand canonical Monte Carlo simulations were performed to support the mixture simulations. The goal of this study was to determine the best membrane material to carry out hydrogen/methane separations. ETS-10 has a three-dimensional pore network. ETS-4 and zorite have two-dimensional pore networks. The simulations carried out in this study show that the increased porosity of ETS-10 results in self-diffusion coefficients for both hydrogen and methane that are higher in ETS-10 than in either ETS-4 or zorite. Methane only showed appreciable displacement in ETS-10. The ability of the methane molecules to move in all three directions in ETS-10 was demonstrated by the high degree of isotropy shown in the values of the x, y, and z components of the self-diffusion coefficient for methane in ETS-10. From our simulations we conclude that ETS-10 would be better suited for fast industrial separations of hydrogen and methane. However, the separation would not result in a pure hydrogen stream. In contrast, ETS-4 and zorite would act as true molecular sieves for separations of hydrogen and methane, as the methane would not move through membranes made of these materials. This was indicated by the near-zero self-diffusion coefficient of methane in ETS-4 and zorite.

  17. Mixture

    Directory of Open Access Journals (Sweden)

    Silva-Aguilar Martín

    2011-01-01

    Full Text Available Metals are ubiquitous pollutants present as mixtures. In particular, mixture of arsenic-cadmium-lead is among the leading toxic agents detected in the environment. These metals have carcinogenic and cell-transforming potential. In this study, we used a two step cell transformation model, to determine the role of oxidative stress in transformation induced by a mixture of arsenic-cadmium-lead. Oxidative damage and antioxidant response were determined. Metal mixture treatment induces the increase of damage markers and the antioxidant response. Loss of cell viability and increased transforming potential were observed during the promotion phase. This finding correlated significantly with generation of reactive oxygen species. Cotreatment with N-acetyl-cysteine induces effect on the transforming capacity; while a diminution was found in initiation, in promotion phase a total block of the transforming capacity was observed. Our results suggest that oxidative stress generated by metal mixture plays an important role only in promotion phase promoting transforming capacity.

  18. Viscosities of binary mixtures of some n-ethoxyethanols with ethyl tert-butyl ether at T = (293.15, 298.15, and 303.15) K

    International Nuclear Information System (INIS)

    Cwiklinska, Aneta; Dzikowski, Tomasz; Szychowski, Dariusz; Kinart, Wojciech J.; Kinart, Cezary M.

    2007-01-01

    Viscosities at T = (293.15, 298.15, and 303.15) K in the binary mixtures of ethyl tert-butyl ether with 2-ethoxyethanol, 2-(2-ethoxyethoxy)ethanol, and 2-[2-(2-ethoxyethoxy)ethoxy]ethanol have been measured over the entire range of mixture compositions. From the experimental data, deviations in the viscosity (Δln η) and excess energies of activation for viscous flow (ΔG *E ) have been calculated. The viscosity data were correlated with equations of Hind et al., Grunberg and Nissan, Auslaender, and McAllister. The results for Δln η and ΔG *E are discussed in terms of intermolecular interactions and structure of studied binary mixtures

  19. Critical Temperature Differences of a Standing Wave Thermoacoustic Prime Mover with Various Helium-Based Binary Mixture Working Gases

    Science.gov (United States)

    Setiawan, Ikhsan; Nohtomi, Makoto; Katsuta, Masafumi

    2015-06-01

    Thermoacoustic prime movers are energy conversion devices which convert thermal energy into acoustic work. The devices are environmentally friendly because they do not produce any exhaust gases. In addition, they can utilize clean energy such as solar-thermal energy or waste heat from internal combustion engines as the heat sources. The output mechanical work of thermoacoustic prime movers are usually used to drive a thermoacoustic refrigerator or to generate electricity. A thermoacoustic prime mover with low critical temperature difference is desired when we intend to utilize low quality of heat sources such as waste heat and sun light. The critical temperature difference can be significantly influenced by the kinds of working gases inside the resonator and stack's channels of the device. Generally, helium gas is preferred as the working gas due to its high sound speed which together with high mean pressure will yield high acoustic power per unit volume of the device. Moreover, adding a small amount of a heavy gas to helium gas may improve the efficiency of thermoacoustic devices. This paper presents numerical study and estimation of the critical temperature differences of a standing wave thermoacoustic prime mover with various helium-based binary-mixture working gases. It is found that mixing helium (He) gas with other common gases, namely argon (Ar), nitrogen (N2), oxygen (O2), and carbon dioxide (CO2), at appropriate pressures and molar compositions, reduce the critical temperature differences to lower than those of the individual components of the gas mixtures. In addition, the optimum mole fractions of Hegas which give the minimum critical temperature differences are shifted to larger values as the pressure increases, and tends to be constant at around 0.7 when the pressure increases more than 2 MPa. However, the minimum critical temperature differences slightly increase as the pressure increases to higher than 1.5 MPa. Furthermore, we found that the lowest

  20. Enhanced CO2 capture in binary mixtures of 1-alkyl-3-methylimidazolium tricyanomethanide ionic liquids with water.

    Science.gov (United States)

    Romanos, George E; Zubeir, Lawien F; Likodimos, Vlassis; Falaras, Polycarpos; Kroon, Maaike C; Iliev, Boyan; Adamova, Gabriela; Schubert, Thomas J S

    2013-10-10

    Absorption of carbon dioxide and water in 1-butyl-3-methylimidazoliun tricyanomethanide ([C4C1im][TCM]) and 1-octyl-3-methylimidazolium tricyanomethanide ([C8C1im][TCM]) ionic liquids (ILs) was systematically investigated for the first time as a function of the H2O content by means of a gravimetric system together with in-situ Raman spectroscopy, excess molar volume (V(E)), and viscosity deviation measurements. Although CO2 absorption was marginally affected by water at low H2O molar fractions for both ILs, an increase of the H2O content resulted in a marked enhancement of both the CO2 solubility (ca. 4-fold) and diffusivity (ca. 10-fold) in the binary [C(n)C1im][TCM]/H2O systems, in contrast to the weak and/or detrimental influence of water in most physically and chemically CO2-absorbing ILs. In-situ Raman spectroscopy on the IL/CO2 systems verified that CO2 is physically absorbed in the dry ILs with no significant effect on their structural organization. A pronounced variation of distinct tricyanomethanide Raman modes was disclosed in the [C(n)C1im][TCM]/H2O mixtures, attesting to the gradual disruption of the anion-cation coupling by the hydrogen-bonded water molecules to the [TCM](-) anions, in accordance with the positive excess molar volumes and negative viscosity deviations for the binary systems. Most importantly, CO2 absorption in the ILs/H2O mixtures at high water concentrations revealed that the [TCM](-) Raman modes tend to restore their original state for the heavily hydrated ILs, in qualitative agreement with the intriguing nonmonotonous transients of CO2 absorption kinetics unveiled by the gravimetric measurements for the hybrid solvents. A molecular exchange mechanism between CO2 in the gas phase and H2O in the liquid phase was thereby proposed to explain the enhanced CO2 absorption in the hybrid [C(n)C1im][TCM]//H2O solvents based on the subtle competition between the TCM-H2O and TCM-CO2 interactions, which renders these ILs very promising for CO2

  1. Estimation of the minimum Prandtl number for binary gas mixtures formed with light helium and certain heavier gases: Application to thermoacoustic refrigerators

    International Nuclear Information System (INIS)

    Campo, Antonio; Papari, Mohammad M.; Abu-Nada, Eiyad

    2011-01-01

    This paper addresses a detailed procedure for the accurate estimation of low Prandtl numbers of selected binary gas mixtures. In this context, helium (He) is the light primary gas and the heavier secondary gases are nitrogen (N 2 ), oxygen (O 2 ), xenon (Xe), carbon dioxide (CO 2 ), methane (CH 4 ), tetrafluoromethane or carbon tetrafluoride (CF 4 ) and sulfur hexafluoride (SF 6 ). The three thermophysical properties forming the Prandtl number of binary gas mixtures Pr mix are heat capacity at constant pressure C p,mix (thermodynamic property), viscosity η mix (transport property) and thermal conductivity λ mix (transport property), which in general depend on temperature T and molar gas composition w. The precise formulas for the calculation of the trio C p,mix , η mix , and λ mix are gathered from various dependable sources. When the set of computed Pr mix values for the seven binary gas mixtures He + N 2 , He + O 2 , He + Xe, He + CO 2 , He + CH 4 , He + CF 4 , He + SF 6 at atmospheric conditions T = 300 K, p = 1 atm is plotted against the molar gas composition w on the w-domain [0,1], the family of Pr mix (w) curves exhibited distinctive concave shapes. In the curves format, all Pr mix (w) curves initiate with Pr ∼ 0.7 at w = 0 (associated with light primary He). Forthwith, each Pr mix (w) curve descends to a unique minimum and thereafter ascend back to Pr ∼ 0.7 at the terminal point w = 1 (connected to heavier secondary gases). Overall, it was found that among the seven binary gas mixtures tested, the He + Xe gas mixture delivered the absolute minimum Prandtl number Pr mix,min = 0.12 at the optimal molar gas composition w opt = 0.975. - Highlights: →Accurate estimation of low Prandtl numbers for some helium-based binary gas mixtures. →The thermophysical properties of the gases are calculated with precise formulas. →The absolute minimum Prandtl number is delivered by the He + Xe binary gas mixture. →Application to experimental thermoacoustic

  2. The many faces (and phases) of ceramide and sphingomyelin II - binary mixtures.

    Science.gov (United States)

    Fanani, María Laura; Maggio, Bruno

    2017-10-01

    A rather widespread idea on the functional importance of sphingolipids in cell membranes refers to the occurrence of ordered domains enriched in sphingomyelin and ceramide that are largely assumed to exist irrespective of the type of N-acyl chain in the sphingolipid. Ceramides and sphingomyelins are the simplest kind of two-chained sphingolipids and show a variety of species, depending on the fatty acyl chain length, hydroxylation, and unsaturation. Abundant evidences have shown that variations of the N-acyl chain length in ceramides and sphingomyelins markedly affect their phase state, interfacial elasticity, surface topography, electrostatics, and miscibility, and that even the usually conceived "condensed" sphingolipids and many of their mixtures may exhibit liquid-like expanded states. Their lateral miscibility properties are subtlety regulated by those chemical differences. Even between ceramides with different acyl chain length, their partial miscibility is responsible for a rich two-dimensional structural variety that impacts on the membrane properties at the mesoscale level. In this review, we will discuss the miscibility properties of ceramide, sphingomyelin, and glycosphingolipids that differ in their N-acyl or oligosaccharide chains. This work is a second part that accompanies a previous overview of the properties of membranes formed by pure ceramides or sphingomyelins, which is also included in this Special Issue.

  3. Synergism studies with binary mixtures of pyrethroid, carbamate and organophosphate insecticides on Frankliniella occidentalis (Pergande).

    Science.gov (United States)

    Bielza, Pablo; Espinosa, Pedro J; Quinto, Vicente; Abellán, Jaime; Contreras, Josefina

    2007-01-01

    The major mechanism of resistance to most insecticides in Frankliniella occidentalis (Pergande) is metabolic, piperonyl butoxide (PBO) suppressible, mediated by cytochrome-P450 monooxygenases and conferring cross-resistance among insecticide classes. The efficacy of insecticide mixtures of acrinathrin, methiocarb, formetanate and chlorpyrifos was studied by topical exposure in strains of F. occidentalis selected for resistance to each insecticide. The method consisted in combining increasing concentrations of one insecticide with a constant low rate of the second one as synergist. Acrinathrin activity against F. occidentalis was enhanced by carbamate insecticides, methiocarb being a much better synergist than formetanate. Monooxygenase action on the carbamates would prevent degradation of the pyrethroid, hence providing a level of synergism by competitive substrate inhibition. However, the number of insecticides registered for control of F. occidentalis is very limited, and they are needed for antiresistance strategies such as mosaics and rotations. Therefore, a study was made of the synergist effect of other carbamates not used against thrips, such as carbofuran and carbosulfan, against a susceptible strain and a field strain. Neither carbamate showed synergism to acrinathrin in the susceptible strain, but both did in the field strain, carbosulfan being a better synergist than carbofuran. The data obtained indicate that low rates of carbamates could be used as synergists to restore some pyrethroid susceptibility in F. occidentalis. Copyright (c) 2006 Society of Chemical Industry.

  4. (Vapour + liquid) equilibria for binary and ternary mixtures of 2-propanol, tetrahydropyran, and 2,2,4-trimethylpentane at P = 101.3 kPa

    International Nuclear Information System (INIS)

    Lin, Dun-Yi; Tu, Chein-Hsiun

    2012-01-01

    Highlights: ► We report the VLE data at P = 101.3 kPa involving a cyclic ether. ► The activity coefficients of mixtures were obtained from modified Raoult’s law. ► The VLE data were correlated by four liquid activity coefficient models. ► The ternary VLE data were predicted from binary parameters of the four models. - Abstract: (Vapour + liquid) equilibrium (VLE) at P = 101.3 kPa have been determined for a ternary system (2-propanol + tetrahydropyran + 2,2,4-trimethylpentane) and its constituent binary systems (2-propanol + tetrahydropyran, 2-propanol + 2,2,4-trimethylpentane), and (tetrahydropyran + 2,2,4-trimethylpentane). Analysis of VLE data reveals that two binary systems (2-propanol + tetrahydropyran) and (2-propanol + 2,2,4-trimethylpentane) have a minimum boiling azeotrope. No azeotrope was found for the ternary system. The activity coefficients of liquid mixtures were obtained from the modified Raoult’s law and were used to calculate the reduced excess molar Gibbs free energy (g E /RT). Thermodynamic consistency tests were performed for all VLE data using the Van Ness direct test for the binary systems and the test of McDermott–Ellis as modified by Wisniak and Tamir for the ternary system. The VLE data of the binary mixtures were correlated using the three-suffix Margules, Wilson, NRTL, and UNIQUAC activity-coefficient models. The models with their best-fitted interaction parameters of the binary systems were used to predict the ternary (vapour + liquid) equilibrium.

  5. The sensitivity of Daphnia magna and Daphnia curvirostris to 10 veterinary antibacterials and to some of their binary mixtures.

    Science.gov (United States)

    Dalla Bona, Mirco; Di Leva, Vincenzo; De Liguoro, Marco

    2014-11-01

    Aim of this study was to evaluate the suitability of Daphnia curvirostris for the acute toxicity test usually performed on Daphnia magna, and to compare the sensitivity of the two species toward 10 antibacterials [enrofloxacin (EFX), ciprofloxacin(CPX), sulfaguanidine (SGD), sulfadiazine (SDZ), sulfamethazine (SMZ), sulfaquinoxaline (SQO), sulfaclozine (SCZ), sulfamerazine (SMA), sulfadimethoxine (SDM) and trimethoprim (TMP)] and some of their binary mixtures. Furthermore, a tentative prolonged-toxicity test (lasting 13d) was settled up in order to evidence toxic responses with drug concentrations that were uneffective in the classic 48h immobilization test. Results showed that D. curvirostris was more sensitive than D. magna to the majority of compounds (6 out of 10). Lowest 48h EC50s were obtained with EFX (4.3mgL(-1) in D. curvirostris) and SGD (6.2mgL(-1) in D. magna). The toxicity of paired compounds was always concentration-additive or less than concentration-additive. In the prolonged-toxicity test mortality and/or reproduction inhibition were constantly observed. It was concluded that: (1) D. curvirostris could be a suitable model for the evaluation of acute toxicity of antibacterials since its sensitivity was generally greater than that of D. magna; (2) the toxicity of EFX and SGD should be given special attention as the two compounds, in the prolonged test, showed to be active at concentrations of 0.9mgL(-1) and 2.5mgL(-1), respectively; (3) the concentration addition is usually a reasonable worst case estimation of the environmental impact of antibacterial mixtures. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Effect of temperature and composition on the surface tension and surface properties of binary mixtures containing DMSO and short chain alcohols

    International Nuclear Information System (INIS)

    Bagheri, Ahmad; Fazli, Mostafa; Bakhshaei, Malihe

    2016-01-01

    Highlights: • Surface tension of DMSO + alcohol (methanol, ethanol and isopropanol) at various temperatures was measured. • The surface tension data of binary mixtures were correlated with four equations. • Intermolecular interaction of DMSO with alcohol was discussed. • The surface mole fraction of alcohol increase with increasing the length of alcohol chain. - Abstract: Surface tension of binary mixtures of methanol, ethanol and isopropanol with DMSO (dimethyl sulfoxide) was measured over the whole range of composition at atmospheric pressure of 82.5 kPa within the temperatures between (298.15 and 328.15) K. The experimental measurements were used to calculate in surface tension deviations (Δσ). The sign of Δσ for all temperatures is negative (except of methanol/DMSO system) because of the factors of hydrogen bonding and dipole–dipole interactions in the DMSO-alcohol systems. Surface tension values of the binary systems were correlated with FLW, MS, RK and LWW models. The mean standard deviation obtained from the comparison of experimental and calculated surface tension values for binary systems with three models (FLW, MS and RK) at various temperatures is less than 0.83. Also, the results of the LWW model were used to account for the interaction energy between alcohols and DMSO in binary mixtures. The temperature dependence of σ (surface tension) at fixed composition of solutions was used to estimate surface enthalpy, H s , and surface entropy, S s . The results obtained show that the values of the thermodynamic parameters for alcohol/DMSO mixtures decrease with increasing alkyl chain length of alcohol. Finally, the results are discussed in terms of surface mole fraction and lyophobicity using the extended Langmuir (EL) isotherm.

  7. The ecotoxicity of binary mixtures of Imazamox and ionized ammonia on freshwater copepods: Implications for environmental risk assessment in groundwater bodies.

    Science.gov (United States)

    Di Marzio, Walter D; Cifoni, Marco; Sáenz, María E; Galassi, Diana M P; Di Lorenzo, Tiziana

    2018-03-01

    Groundwater bodies are impacted by substances such as pesticides and N-fertilizers, which usually occur in the environment as complex mixtures rather than isolated pollutants. The threat that these mixtures pose to groundwater-dwelling organisms is still poorly understood. The aims of the present study were to test the acute effect of a binary mixture of a herbicide (Imazamox) and NH 4 + on epigean (Eucyclops serrulatus) and hypogean (Diacyclops belgicus) freshwater copepod species. In addition, to evaluate if the effect of the mixture can be explained by referencing non-interaction models or by more complex interaction models; and the implications for groundwater risk assessment. Compared with the action of the compounds evaluated separately, the effects of Imazamox and NH 4 + in the binary mixture were more than additive or synergistic for both species. MixTox models evidenced a dose ratio and dose level deviations from concentration addition and independent action traditional models. The hypogean species was three times more sensitive to NH 4 + that the epigean species when assayed as a single chemical. However, D. belgicus was only 1.13 times more sensitive than E. serrulatus when NH 4 + was assayed in the mixture. The use of an integrated approach for substances that are known to interact in groundwater, should include copepods species as test organisms. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Cytotoxicity of binary mixtures of human pharmaceuticals in a fish cell line: approaches for non-monotonic concentration-response relationships.

    Science.gov (United States)

    Bain, Peter A; Kumar, Anupama

    2014-08-01

    Predicting the effects of mixtures of environmental micropollutants is a priority research area. In this study, the cytotoxicity of ten pharmaceuticals to the rainbow trout cell line RTG-2 was determined using the neutral red uptake assay. Fluoxetine (FL), propranolol (PPN), and diclofenac (DCF) were selected for further study as binary mixtures. Biphasic concentration-response relationships were observed in cells exposed to FL and PPN. In the case of PPN, microscopic examination revealed lysosomal swelling indicative of direct uptake and accumulation of the compound. Three equations describing non-monotonic concentration-response relationships were evaluated and one was found to consistently provide more accurate estimates of the median and 10% effect concentrations compared with a sigmoidal concentration-response model. Predictive modeling of the effects of binary mixtures of FL, PPN, and DCF was undertaken using an implementation of the concentration addition (CA) conceptual model incorporating non-monotonic concentration-response relationships. The cytotoxicity of the all three binary combinations could be adequately predicted using CA, suggesting that the toxic mode of action in RTG-2 cells is unrelated to the therapeutic mode of action of these compounds. The approach presented here is widely applicable to the study of mixture toxicity in cases where non-monotonic concentration-response relationships are observed. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  9. Thermodynamic properties of (tetradecane + benzene, + toluene, + chlorobenzene, + bromobenzene, + anisole) binary mixtures at T = (298.15, 303.15, and 308.15) K

    International Nuclear Information System (INIS)

    Mutalik, Venkatesh; Manjeshwar, Lata S.; Sairam, Malladi; Aminabhavi, Tejraj M.

    2006-01-01

    Density ρ, viscosity η, and refractive index n D , values for (tetradecane + benzene, + toluene, + chlorobenzene, + bromobenzene, + anisole) binary mixtures over the entire range of mole fraction have been measured at temperatures (298.15, 303.15, and 308.15) K at atmospheric pressure. The speed of sound u has been measured at T = 298.15 K only. Using these data, excess molar volume V E , deviations in viscosity Δη, Lorentz-Lorenz molar refraction ΔR, speed of sound Δu, and isentropic compressibility Δk s have been calculated. These results have been fitted to the Redlich and Kister polynomial equation to estimate the binary interaction parameters and standard deviations. Excess molar volumes have exhibited both positive and negative trends in many mixtures, depending upon the nature of the second component of the mixture. For the (tetradecane + chlorobenzene) binary mixture, an incipient inversion has been observed. Calculated thermodynamic quantities have been discussed in terms of intermolecular interactions between mixing components

  10. Physico-chemical properties of binary mixtures of N,N-dimethylformamide with 1-octanol, 1-nonanol and 1-decanol at different temperatures

    International Nuclear Information System (INIS)

    AlTuwaim, Mohammad S.; Alkhaldi, Khaled H.A.E.; Al-Jimaz, Adel S.; Mohammad, Abubaker A.

    2013-01-01

    Highlights: ► Physical properties of binary mixtures of DMF+1-octanol, 1-nonanol or 1-decanol at different temperatures were investigated. ► Densities, refractive indices and speed of sound were measured. ► V E , K s E , u D and n D E were calculated using the experimental data. ► Speed of sound data were analyzed using different theories and relations. -- Abstract: The density, refractive index and speed of sound for binary mixtures of N,N-dimethylformamide with 1-octanol, 1-nonanol and 1-decanol were measured at several temperatures and atmospheric pressure over the entire range of mole fraction. Excess molar volumes, isentropic and excess isentropic compressibilities, excess refractive indices and deviations in speed of sound for the above systems were calculated from the experimental results. Furthermore, excess properties and deviations in speed of sound were fitted to the Redlich–Kister polynomial. The Lorentz–Lorenz, Dale–Gladstone, Eykman and Arago–Biot mixing rules were used to calculate the refractive indices of the binary mixtures. The speeds of sound have been analyzed in term of Schaaffs’ collision factor theory, Jacobson’s intermolecular free length theory of solutions, Nomoto relation and Van Deal ideal mixture relation. The calculated excess molar properties have been qualitatively used to explain the intermolecular interaction between the mixed components as well as the effects of n-alkanol chain length

  11. Free Energy-Based Coarse-Grained Force Field for Binary Mixtures of Hydrocarbons, Nitrogen, Oxygen, and Carbon Dioxide.

    Science.gov (United States)

    Cao, Fenglei; Deetz, Joshua D; Sun, Huai

    2017-01-23

    The free energy based Lennard-Jones 12-6 (FE-12-6) coarse-grained (CG) force field developed for alkanes1 has been extended to model small molecules of light hydrocarbons (methane, ethane, propane, butane, and isobutane), nitrogen, oxygen, and carbon dioxide. The adjustable parameters of the FE-12-6 potential are determined by fitting against experimental vapor-liquid equilibrium (VLE) curves and heat of vaporization (HOV) data for pure substance liquids. Simulations using the optimized FE-12-6 parameters correctly reproduced experimental measures of the VLE, HOV, density, vapor pressure, compressibility, critical point, and surface tension for pure substances over a wide range of thermodynamic states. The force field parameters optimized for pure substances were tested on methane/butane, nitrogen/decane, and carbon dioxide/decane binary mixtures to predict their vapor-liquid equilibrium phase diagrams. It is found that for nonpolar molecules represented by different sized beads, a common scaling factor (0.08) that reduces the strength of the interaction potential between unlike beads, generated using Lorentz-Berthelot (LB) combination rules, is required to predict vapor-liquid phase equilibria accurately.

  12. Observation of a sequence of wetting transitions in the binary water+ethylene glycol monobutyl ether mixture

    Science.gov (United States)

    Wu, Chih-Kang; Chen, Li-Jen

    2005-08-01

    A homemade pendant drop/bubble tensiometer was assembled and applied to perform the surface-interfacial tension measurements for the binary water+ethylene glycol monobutyl ether (C4E1) mixture over the temperature range from 50to128°C at 10bar. The symbol CiEj is the abbreviation of a nonionic polyoxyethylene alcohol CiH2i+1(OCH2CH2)jOH. The wetting behavior of the C4E1-rich phase at the interface separating the gas and the aqueous phases was systematically examined according to the wetting coefficient calculated from the experimental results of surface/interfacial tensions. It was found that the C4E1-rich phase exhibits a sequence of wetting transitions, nonwetting→partial wetting→complete wetting, at the gas-water interface in the water+C4E1 system along with increasing the temperature, consistent with the conjecture of Kahlweit and Busse [J. Chem. Phys. 91, 1339 (1989)]. In addition, the relationship of the mutual solubility and the interfacial tension of the interface separating the C4E1-rich phase and the aqueous phase is discussed.

  13. Dielectric relaxation studies of binary mixture of β-picoline and methanol using time domain reflectometry at different temperatures

    Directory of Open Access Journals (Sweden)

    C. M. Trivedi

    2016-09-01

    Full Text Available Complex permittivity spectra of binary mixtures of varying concentrations of β-picoline and Methanol (MeOH have been obtained using time domain reflectometry (TDR technique over frequency range 10 MHz to 25 GHz at 283.15, 288.15, 293.15 and 298.15 K temperatures. The dielectric relaxation parameters namely static permittivity (ε0, high frequency limit permittivity (ε∞1 and the relaxation time (τ were determined by fitting complex permittivity data to the single Debye/Cole-Davidson model. Complex nonlinear least square (CNLS fitting procedure was carried out using LEVMW software. The excess permittivity (ε0E and the excess inverse relaxation time (1/τE which contain information regarding molecular structure and interaction between polar–polar liquids were also determined. From the experimental data, parameters such as effective Kirkwood correlation factor (geff, Bruggeman factor (fB and some thermo dynamical parameters have been calculated. Excess parameters were fitted to the Redlich–Kister polynomial equation. The values of static permittivity and relaxation time increase nonlinearly with increase in the mol–fraction of MeOH at all temperatures. The values of excess static permittivity (ε0E and the excess inverse relaxation time (1/τE are negative for the studied β-picoline — MeOH system at all temperatures.

  14. The effect of the alkyl chain length on physicochemical features of (ionic liquids + γ-butyrolactone) binary mixtures

    International Nuclear Information System (INIS)

    Papović, Snežana; Bešter-Rogač, Marija; Vraneš, Milan; Gadžurić, Slobodan

    2016-01-01

    Highlights: • Influence of alkyl substituent length on IL properties was studied. • Nature of interactions between studied [C n C 1 im][NTf 2 ] and GBL were discussed. • Angell strength parameter indicates [C n C 1 im][NTf 2 ] are fragile liquids. • ILs properties regularly change with increase of the alkyl chain length. • Absence of GBL self-association upon addition of IL is observed. - Abstract: Densities and viscosities were determined and analysed for γ-butyrolactone (GBL) binary mixtures with 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids (where alkyl = ethyl, hexyl, octyl) as a function of temperature at atmospheric pressure (p = 0.1 MPa) and over the whole composition range. Excess molar volumes have been calculated from the experimental densities and were fitted using Redlich–Kister’s polynomial equation. Other volumetric parameters have been also calculated in order to obtain information about interactions between GBL and imidazolium based ionic liquids with different alkyl chain length. From the viscosity measurements, the Angell strength parameter was calculated for pure ionic liquids indicating that all investigated electrolytes are “fragile” liquids.

  15. Modeling of columnar and equiaxed solidification of binary mixtures; Modelisation de la solidification colonnaire et equiaxe de melanges binaires

    Energy Technology Data Exchange (ETDEWEB)

    Roux, P

    2005-12-15

    This work deals with the modelling of dendritic solidification in binary mixtures. Large scale phenomena are represented by volume averaging of the local conservation equations. This method allows to rigorously derive the partial differential equations of averaged fields and the closure problems associated to the deviations. Such problems can be resolved numerically on periodic cells, representative of dendritic structures, in order to give a precise evaluation of macroscopic transfer coefficients (Drag coefficients, exchange coefficients, diffusion-dispersion tensors...). The method had already been applied for a model of columnar dendritic mushy zone and it is extended to the case of equiaxed dendritic solidification, where solid grains can move. The two-phase flow is modelled with an Eulerian-Eulerian approach and the novelty is to account for the dispersion of solid velocity through the kinetic agitation of the particles. A coupling of the two models is proposed thanks to an original adaptation of the columnar model, allowing for undercooling calculation: a solid-liquid interfacial area density is introduced and calculated. At last, direct numerical simulations of crystal growth are proposed with a diffuse interface method for a representation of local phenomena. (author)

  16. Binary non-additive hard sphere mixtures: fluid demixing, asymptotic decay of correlations and free fluid interfaces

    International Nuclear Information System (INIS)

    Hopkins, Paul; Schmidt, Matthias

    2010-01-01

    Using a fundamental measure density functional theory we investigate both bulk and inhomogeneous systems of the binary non-additive hard sphere model. For sufficiently large (positive) non-additivity the mixture phase separates into two fluid phases with different compositions. We calculate bulk fluid-fluid coexistence curves for a range of size ratios and non-additivity parameters and find that they compare well to simulation results from the literature. Using the Ornstein-Zernike equation, we investigate the asymptotic, r→∞, decay of the partial pair correlation functions, g ij (r). At low densities a structural crossover occurs in the asymptotic decay between two different damped oscillatory modes with different wavelengths corresponding to the two intra-species hard-core diameters. On approaching the fluid-fluid critical point there is a Fisher-Widom crossover from exponentially damped oscillatory to monotonic asymptotic decay. Using the density functional we calculate the density profiles for the planar free fluid-fluid interface between coexisting fluid phases. We show that the type of asymptotic decay of g ij (r) not only determines the asymptotic decay of the interface profiles, but is also relevant for intermediate and even short-ranged behaviour. We also determine the surface tension of the free fluid interface, finding that it increases with non-additivity, and that on approaching the critical point mean-field scaling holds.

  17. Preparation of thermosensitive membranes by radiation grafting of acrylic acid/N-isopropyl acrylamide binary mixture on PET fabric

    International Nuclear Information System (INIS)

    Gupta, Bhuvanesh; Mishra, Swaiti; Saxena, Shalini

    2008-01-01

    Thermosensitive membranes were prepared by radiation-induced graft copolymerization of monomers on PET fabrics. A binary mixture of N-isopropyl acrylamide (NIPAAm) and acrylic acid (AA) was grafted on polyester fabric as a base material to introduce thermosensitive poly(N-isopropyl acrylamide) pendant chains having LCST slightly higher than 37 deg. C in the membrane. The influence of ferrous sulfate, radiation dose and monomer composition on the degree of grafting was studied. The structure of the grafted fabric was characterized by thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy. The thermosensitive nature of the fabric was monitored by swelling at different temperatures. The graft copolymerization of AA with NIPAAm enhanced the LCST of the resultant membrane to ∼37 deg. C. The moisture vapor transmission rate (MVTR) and air permeability of the fabric decreased slightly, may be due to the slight blocking of the fabric pores. The immobilization of tetracycline hydrochloride as the model drug and its release characteristics at different temperatures were monitored

  18. Densities and volumetric properties of (N-acetylmorpholine + aromatic hydrocarbon) binary mixtures from T = (293.15 to 343.15) K

    International Nuclear Information System (INIS)

    Abu-Daabes, Malyuba A.; Awwad, Akl M.; Al-Ani, Hawzen A.

    2009-01-01

    The experimental densities, ρ for binary mixtures of (N-acetylmorpholine + benzene, +toluene, +ethylbenzene, and +mesitylene) have been measured at temperatures from (293.15 to 343.15) K and atmospheric pressure over the whole mole fraction range. From these results, excess molar volumes V E have been calculated and fitted to the Redlich-Kister polynomial equation. The V E values are negative over the whole mole fraction range and at all temperatures. Thermal expansion coefficients α i , apparent molar volumes Vφ i , and partial molar volumes at infinite dilution V i ∞ have been calculated. The variation of these properties with composition and temperature of the binary mixtures are discussed in terms of molecular interactions

  19. Vapour pressures, osmotic and activity coefficients for binary mixtures containing (1-ethylpyridinium ethylsulfate + several alcohols) at T = 323.15 K

    International Nuclear Information System (INIS)

    Calvar, Noelia; Gomez, Elena; Dominguez, Angeles; Macedo, Eugenia A.

    2010-01-01

    Osmotic coefficients of binary mixtures containing several primary and secondary alcohols (1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol) and the pyridinium-based ionic liquid 1-ethylpyridinium ethylsulfate were determined at T = 323.15 K using the vapour pressure osmometry technique. From the experimental results, vapour pressure and activity coefficients can be determined. For the correlation of osmotic coefficients, the extended Pitzer model modified by Archer, and the modified NRTL (MNRTL) model were used, obtaining deviations lower than 0.017 and 0.047, respectively. The mean molal activity coefficients and the excess Gibbs free energy for the binary mixtures studied were determined from the parameters obtained with the extended Pitzer model modified by Archer.

  20. Effect of genetic algorithm as a variable selection method on different chemometric models applied for the analysis of binary mixture of amoxicillin and flucloxacillin: A comparative study

    Science.gov (United States)

    Attia, Khalid A. M.; Nassar, Mohammed W. I.; El-Zeiny, Mohamed B.; Serag, Ahmed

    2016-03-01

    Different chemometric models were applied for the quantitative analysis of amoxicillin (AMX), and flucloxacillin (FLX) in their binary mixtures, namely, partial least squares (PLS), spectral residual augmented classical least squares (SRACLS), concentration residual augmented classical least squares (CRACLS) and artificial neural networks (ANNs). All methods were applied with and without variable selection procedure (genetic algorithm GA). The methods were used for the quantitative analysis of the drugs in laboratory prepared mixtures and real market sample via handling the UV spectral data. Robust and simpler models were obtained by applying GA. The proposed methods were found to be rapid, simple and required no preliminary separation steps.

  1. Properties of L-ascorbic acid in water and binary aqueous mixtures of D-glucose and D-fructose at different temperatures

    Science.gov (United States)

    Sharma, Ravi; Thakur, R. C.; Sani, Balwinder; Kumar, Harsh

    2017-12-01

    Using density and sound velocity partial molar volumes, partial molar adiabatic compressibilities, partial molar expansibilities and structure of L-ascorbic acid have been determined in water and aqueous mixtures of D-glucose and D-fructose at different concentrations and temperatures. Masson's equation was used to analyze the measured data. The obtained parameters have been interpreted in terms of solute-solute and solute-solvent interactions. It is found that the L-ascorbic acid acts as structure breaker in water as well in binary studied mixtures.

  2. Volumetric properties of binary mixtures of tributylamine with benzene derivatives and comparison with ERAS model results at temperatures from (293.15 to 333.15) K

    International Nuclear Information System (INIS)

    Behroozi, Mahboobe; Zarei, Hosseinali

    2012-01-01

    Highlights: ► The V m E values of tributylamine with aromatics were determined at (293.15 to 333.15) K. ► The values are positive (except nitrobenzene). ► Different behavior was observed at high temperatures. ► The results were correlated with Redlich–Kister equation and ERAS model. - Abstract: Binary mixtures of tributylamine with aromatics (toluene, ethylbenzene, o-xylene, m-xylene, p-xylene and nitrobenzene) were selected in order to investigate intermolecular interactions by calculation of their excess molar volume V m E , from density measurements. Thermal expansion coefficients α p , and their excess values of α E , were obtained from the density data. The V m E values were positive for all the mixtures except for the (tributylamine + nitrobenzene) binary mixture over the entire range of composition and lower temperatures and become more positive with rising temperature. At high temperatures, sigmoidal behavior was observed for the mixture of (tributylamine + o-xylene). The mixture of (tributylamine + nitrobenzene) shows negative values for V m E and become more negative with increasing temperature. The experimental data were correlated to Redlich–Kister equation. In order to characterize the V m E values, the extended real associated solution (ERAS) model was applied at different temperatures.

  3. Solubility of pioglitazone hydrochloride in binary mixtures of polyethylene glycol 400 with ethanol, propylene glycol, N-methyl-2-pyrrolidone, and water at 25 degrees C.

    Science.gov (United States)

    Jouyban, Abolghasem; Soltanpour, Shahla

    2010-09-01

    The solubility of pioglitazone hydrochloride in binary mixtures of polyethylene glycol 400 with ethanol, N-methyl-2-pyrrolidone, propylene glycol, and water at 25 degrees C are reported. The generated data are fitted to the Jouyban-Acree model and the mean relative deviations are 2.6%, 1.5%, 5.8%, and 7.4%, respectively for ethanol, N-methyl-2-pyrrolidone, propylene glycol, and water.

  4. PHASE-TRANSITIONS IN THE BILAYERS OF VESICLES FORMED FROM BINARY-MIXTURES OF SYMMETRICAL DI-N-ALKYLPHOSPHATES IN AQUEOUS-SOLUTIONS

    NARCIS (Netherlands)

    BLANDAMER, MJ; BRIGGS, B; CULLIS, PM; ENGBERTS, JBFN; WAGENAAR, A; SMITS, E; HOEKSTRA, D; KACPERSKA, A

    1994-01-01

    Vesicles in aqueous solutions were prepared from binary equimolar mixtures of di-n-alkyl-phosphates (sodium and potassium), (R(1)O)(2)PO(2)(-)M(+) and (R(2)O)(2)PO(2)(-)M(+). When the number of carbon atoms in R(1) and R(2) differs by two and when R(1) or R(2) = C12H25, C14H29, C16H33 and C18H37 the

  5. Dropping and semimicrotest glass reactions on beryllium, lenthanum, vanadyl and uranyl cations with synthetic organic dyes and their mutual determination in binary mixtures

    International Nuclear Information System (INIS)

    Shemyakin, F.M.; Novikova, A.A.; Reshetnyak, V.Yu.; Teplyakov, G.K.; Nekrasov, E.L.

    1978-01-01

    Coloured reactions for beryllium, lanthanum, vanadyl and uranyl cations with a number of organic dyes, have been studied. These reactions are used in dropping analysis on papers, impregnated with relevant dyes, and for semimicro-test glass reactions on the above cations. Sensitivity and maximum permissible dilution have been determined for each of the reactions. Mutual determinations of relevant couples of the above cations have been performed. It is shown, that such binary mixtures enable to freely open relevant cations

  6. Osmotic properties of binary mixtures 1-butyl-1-methylpyrrolidinium dicyanamide and 1-methyl-3-octylimidazolium chloride with water: Effect of aggregation of ions

    International Nuclear Information System (INIS)

    Ahmed, Sayeed Ashique; Chatterjee, Aninda; Maity, Banibrata; Seth, Debabrata

    2015-01-01

    Graphical abstract: Osmotic properties of binary mixture of two ionic liquids (ILs): 1-butyl-1-methyl pyrrolidinium dicyanamide and 1-methyl-3-octylimidazolium chloride with water was reported by using vapour pressure osmometry (VPO) method. - Highlights: • Osmotic properties of binary mixture of ionic liquids (ILs) with water by using vapour pressure osmometry (VPO) method. • The experimental osmotic coefficients were well correlated by Archer extension of Pitzer model. • From the experimental osmotic coefficient data the critical micellar concentration (cmc) of the ILs in water was estimated. • Mean molar activity coefficient and the excess Gibbs free energy was determine for the (ILs + water) binary mixture. - Abstract: In this work, the osmotic properties of the binary mixture of ionic liquids (ILs) and water were studied by using vapour pressure osmometry (VPO) method. We have used two ILs: 1-butyl-1-methyl pyrrolidinium dicyanamide and 1-methyl-3-octylimidazolium chloride. The aqueous solution of NaCl was used as the reference solution to precisely measure the osmotic coefficients of the above systems. We have calculated the activity of water in the above systems and the change of vapour pressure of water due to the addition of ILs in water. The experimental osmotic coefficients were correlated by the Archer extension of Pitzer model. The parameters of this Archer extension of Pitzer model were found from this data fitting. From the experimental osmotic coefficient value we have estimated the critical micellar concentration (cmc) of ILs in water. The experimental values of osmotic coefficient in the above systems were compared with the literature and the reason of variation was explained, in terms of the aggregation of ILs in water

  7. Measurement and modeling of osmotic coefficients of binary mixtures (alcohol + 1,3-dimethylpyridinium methylsulfate) at T = 323.15 K

    International Nuclear Information System (INIS)

    Gomez, Elena; Calvar, Noelia; Dominguez, Angeles; Macedo, Eugenia A.

    2011-01-01

    Research highlights: → The osmotic coefficients of binary mixtures (alcohol + ionic liquid) were determined. → The measurements were carried out with a vapor pressure osmometer at 323.15 K. → The Pitzer-Archer, and the MNRTL models were used to correlate the experimental data. → Mean molal activity coefficients and excess Gibbs free energies were calculated. - Abstract: Measurement of osmotic coefficients of binary mixtures containing several primary and secondary alcohols (1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol) and the pyridinium-based ionic liquid 1,3-dimethylpyridinium methylsulfate were performed at T = 323.15 K using the vapor pressure osmometry technique, and from experimental data, vapor pressure, and activity coefficients were determined. The extended Pitzer model modified by Archer, and the NRTL model modified by Jaretun and Aly (MNRTL) were used to correlate the experimental osmotic coefficients, obtaining standard deviations lower than 0.017 and 0.054, respectively. From the parameters obtained with the extended Pitzer model modified by Archer, the mean molal activity coefficients and the excess Gibbs free energy for the studied binary mixtures were calculated. The effect of the cation is studied comparing the experimental results with those obtained for the ionic liquid 1,3-dimethylimidazolium methylsulfate.

  8. Experimental determination of the (vapor + liquid) equilibrium data of binary mixtures of fatty acids by differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Matricarde Falleiro, Rafael M. [LPT, Department of Chemical Processes (DPQ), School of Chemical Engineering, University of Campinas (UNICAMP), P.O. Box 6066, 13083-970 Campinas, SP (Brazil); Meirelles, Antonio J.A. [EXTRAE, Department of Food Engineering (DEA), School of Food Engineering, University of Campinas (UNICAMP), P.O. Box 6121, 13083-862 Campinas, SP (Brazil); Kraehenbuehl, Maria A., E-mail: mak@feq.unicamp.b [LPT, Department of Chemical Processes (DPQ), School of Chemical Engineering, University of Campinas (UNICAMP), P.O. Box 6066, 13083-970 Campinas, SP (Brazil)

    2010-01-15

    (Vapor + liquid) equilibrium (VLE) data for three binary mixtures of saturated fatty acids were obtained by differential scanning calorimetry (DSC). However, changes in the calorimeter pressure cell and the use of hermetic pans with holes (phi = 250 mm) in the lids were necessary to make it possible to apply this analytical technique, obtaining accurate results with smaller samples and shorter operational times. The systems evaluated in this study were: myristic acid (C{sub 14:0}) + palmitic acid (C{sub 16:0}), myristic acid (C{sub 14:0}) + stearic acid (C{sub 18:0}), and palmitic acid (C{sub 16:0}) + stearic acid (C{sub 18:0}), all measured at 50 mm Hg and with mole fractions between 0.0 and 1.0 in relation to the most volatile component of each diagram. The fugacity coefficients for the components in the vapor phase were calculated using the Hayden and O'Connell method [J.G. Hayden, J.P. O'Connell, Ind. Eng. Chem. Process Design Develop. 14 (3) (1975) 209-216] and the activity coefficients for the liquid phase were correlated with the traditional g{sup E} models (NRTL [H. Renon, J.M. Prausnitz, Aiche J. 14 (1968) 135-144], UNIQUAC [D.S. Abrams, J.M. Prausnitz, Aiche J. 21 (1975) 116-128], and Wilson [J.M. Prausnitz, N.L. Linchtenthaler, E.G. Azevedo, Molecular Thermodynamics of Fluid-phase Equilibria, River-Prentice Hall, Upper Saddle, 1999]). The sets of parameters were then compared in order to determine which adjustments best represented the VLE.

  9. Measuring and modeling of binary mixture effects of pharmaceuticals and nickel on cell viability/cytotoxicity in the human hepatoma derived cell line HepG2

    International Nuclear Information System (INIS)

    Rudzok, S.; Schlink, U.; Herbarth, O.; Bauer, M.

    2010-01-01

    The interaction of drugs and non-therapeutic xenobiotics constitutes a central role in human health risk assessment. Still, available data are rare. Two different models have been established to predict mixture toxicity from single dose data, namely, the concentration addition (CA) and independent action (IA) model. However, chemicals can also act synergistic or antagonistic or in dose level deviation, or in a dose ratio dependent deviation. In the present study we used the MIXTOX model (EU project ENV4-CT97-0507), which incorporates these algorithms, to assess effects of the binary mixtures in the human hepatoma cell line HepG2. These cells possess a liver-like enzyme pattern and a variety of xenobiotic-metabolizing enzymes (phases I and II). We tested binary mixtures of the metal nickel, the anti-inflammatory drug diclofenac, and the antibiotic agent irgasan and compared the experimental data to the mathematical models. Cell viability was determined by three different methods the MTT-, AlamarBlue (registered) and NRU assay. The compounds were tested separately and in combinations. We could show that the metal nickel is the dominant component in the mixture, affecting an antagonism at low-dose levels and a synergism at high-dose levels in combination with diclofenac or irgasan, when using the NRU and the AlamarBlue assay. The dose-response surface of irgasan and diclofenac indicated a concentration addition. The experimental data could be described by the algorithms with a regression of up to 90%, revealing the HepG2 cell line and the MIXTOX model as valuable tool for risk assessment of binary mixtures for cytotoxic endpoints. However the model failed to predict a specific mode of action, the CYP1A1 enzyme activity.

  10. Volumetric, viscometric, spectral studies and viscosity modelling of binary mixtures of esters and alcohols (diethyl succinate, or ethyl octanoate + isobutanol, or isopentanol) at varying temperatures

    International Nuclear Information System (INIS)

    Majstorović, Divna M.; Živković, Emila M.; Matija, Lidija R.; Kijevčanin, Mirjana Lj.

    2017-01-01

    Highlights: • Densitis and viscosities of four ester + alcohol binary mixtures were measured. • Excess and deviation functions were calculated. • Fourier transform infrared (FT-IR) spectroscopy analysis was conducted. • Molecular interactions present in the mixture were analyzed. • Viscosity modelling was performed. - Abstract: Density, viscosity and refractive index of four binary mixtures consisting of diethyl succinate or ethyl octanoate + 2-methyl-1-propanol or 3-methyl-1-butanol have been measured at atmospheric pressure and over the temperature range from 288.15 K to 323.15 K. Excess and deviation functions have been calculated from these data and fitted to the Redlich-Kister equation. The values of excess molar volume and deviation functions, with FT-IR study, were further used in the analysis of molecular interactions present in the mixture as well as the temperature influence on them. Molar excess Gibbs free energies of activation of viscous flow were additionally calculated from measured density and viscosity data for better understanding of present molecular interactions. Viscosity modelling was done with two approaches, predictive by group contribution models (UNIFAC-VISCO and ASOG-VISCO), and correlative by one to three-parameter models (Teja-Rice, Grunberg–Nissan, McAlister, Eyring-UNIQUAC and Eyring-NRTL). The obtained results were compared with experimental data and conclusions about applied approaches and models were made.

  11. Osmotic Suppression of Positional Fluctuation of a Trapped Particle in a Near-Critical Binary Fluid Mixture in the Regime of the Gaussian Model

    Science.gov (United States)

    Fujitani, Youhei

    2017-11-01

    Suppose a spherical colloidal particle surrounded by a near-critical binary fluid mixture in the homogeneous phase. The particle surface usually preferentially attracts one component of the mixture, and the resultant concentration gradient, which causes the osmotic pressure, becomes significant in the ambient near-criticality. The concentration profile is deformed by the particle motion, and can generate a nonzero force exerted on the moving particle. This link was previously shown to slightly suppress the positional equal-time correlation of a particle trapped by a harmonic potential. This previous study presupposed a small fluctuation amplitude of a particle much larger than the correlation length, a weak preferential attraction, and the Gaussian model for the free-energy functional of the mixture. In the present study, we calculate the equal-time correlation without assuming the weak preferential attraction and show that the suppression becomes much more distinct in some range of the trap stiffness because of the increased induced mass. This suggests the possible experimental usage of a trapped particle as a probe for local environments of a near-critical binary fluid mixture.

  12. Small Composers

    DEFF Research Database (Denmark)

    Holgersen, Sven-Erik; Bruun, Peter; Tjagvad, Mette

    2018-01-01

    The present chapter discusses roles and responsibilities of the collaborating partners in a creative music workshop called Small Composers. The aim is to be attentive to a number of potential alterations implicated by the collaborating partners’ different backgrounds. The following questions guided...... the study: What expectations do the class teacher and the professional musicians have to the creative practice, i.e. to the collaboration and to the musical outcome? To which extent do the collaborating partners share a common understanding of the aim, content and method of the workshop? How do the roles...... and responsibilities of the collaborating partners become visible through the practice? How do the professional identities of the teacher and the musicians become visible and what are the implications for the workshop as a musical community of practice?...

  13. Small Composers

    DEFF Research Database (Denmark)

    Holgersen, Sven-Erik; Bruun, Peter; Tjagvad, Mette

    2018-01-01

    The present chapter discusses roles and responsibilities of the collaborating partners in a creative music workshop called Small Composers. The aim is to be attentive to a number of potential alterations implicated by the collaborating partners’ different backgrounds. The following questions guid...... and responsibilities of the collaborating partners become visible through the practice? How do the professional identities of the teacher and the musicians become visible and what are the implications for the workshop as a musical community of practice?...... the study: What expectations do the class teacher and the professional musicians have to the creative practice, i.e. to the collaboration and to the musical outcome? To which extent do the collaborating partners share a common understanding of the aim, content and method of the workshop? How do the roles...

  14. Development of a Physiologically Based Pharmacokinetic and Pharmacodynamic Model to Determine Dosimetry and Cholinesterase Inhibition for a Binary Mixture of Chlorpyrifos and Diazinon in the Rat

    Energy Technology Data Exchange (ETDEWEB)

    Timchalk, Chuck; Poet, Torka S.

    2008-05-01

    Physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models have been developed and validated for the organophosphorus (OP) insecticides chlorpyrifos (CPF) and diazinon (DZN). Based on similar pharmacokinetic and mode of action properties it is anticipated that these OPs could interact at a number of important metabolic steps including: CYP450 mediated activation/detoxification, and blood/tissue cholinesterase (ChE) binding/inhibition. We developed a binary PBPK/PD model for CPF, DZN and their metabolites based on previously published models for the individual insecticides. The metabolic interactions (CYP450) between CPF and DZN were evaluated in vitro and suggests that CPF is more substantially metabolized to its oxon metabolite than is DZN. These data are consistent with their observed in vivo relative potency (CPF>DZN). Each insecticide inhibited the other’s in vitro metabolism in a concentration-dependent manner. The PBPK model code used to described the metabolism of CPF and DZN was modified to reflect the type of inhibition kinetics (i.e. competitive vs. non-competitive). The binary model was then evaluated against previously published rodent dosimetry and ChE inhibition data for the mixture. The PBPK/PD model simulations of the acute oral exposure to single- (15 mg/kg) vs. binary-mixtures (15+15 mg/kg) of CFP and DZN at this lower dose resulted in no differences in the predicted pharmacokinetics of either the parent OPs or their respective metabolites; whereas, a binary oral dose of CPF+DZN at 60+60 mg/kg did result in observable changes in the DZN pharmacokinetics. Cmax was more reasonably fit by modifying the absorption parameters. It is anticipated that at low environmentally relevant binary doses, most likely to be encountered in occupational or environmental related exposures, that the pharmacokinetics are expected to be linear, and ChE inhibition dose-additive.

  15. Potentiometric investigations of (acid+base) equilibria in (n-butylamine+acetic acid) systems in binary (acetone+cyclohexane) solvent mixtures

    International Nuclear Information System (INIS)

    Czaja, MaIgorzata; Kozak, Anna; Makowski, Mariusz; Chmurzynski, Lech

    2005-01-01

    By using the potentiometric titration method, standard equilibrium constants have been determined of acid dissociation of molecular acid, K a (HA), cationic acid, K a (BH + ), of anionic and cationic homoconjugation, K AHA - andK BHB + , respectively, and of molecular heteroconjugation, K AHB (K BHA ), in (acid+base) systems without proton transfer consisting of n-butylamine and acetic acid in binary (acetone+cyclohexane) solvent mixtures. The results have shown that both the pK a (HA) and pK a (BH + ), as well as lgK AHA - values change non-linearly as a function of composition of the solvent mixture. On the other hand, standard molecular heteroconjugation constants without proton transfer do not depend on the cyclohexane content in the mixture, i.e. on solvent polarity

  16. Statistical mechanics of light elements at high pressure. VIII - Thomas-Fermi-Dirac theory for binary mixtures of H with He, C, and O. [in Jupiter planet interiors

    Science.gov (United States)

    Hubbard, W. B.; Macfarlane, J. J.

    1985-01-01

    We present three-dimensional Thomas-Fermi-Dirac calculations of lattice mixing energies of hydrogen with carbon and oxygen atoms, respectively. The results are used to derive effective interatomic potentials for use in liquid-state mixture calculations. We then use the potentials to derive analytic expressions for binary mixture-free energies and to map out the phase diagrams of mixtures of hydrogen with, respectively, helium, carbon, and oxygen, over a pressure range of about 5 to about 10 to the 3rd Mbar. Within this pressure range, all three of the latter elements are found to have unlimited solubility in metallic hydrogen over a temperature range which lies above their pure-element melting temperatures, and which includes likely interior temperatures in the Jovian planets.

  17. Potentiometric investigations of (acid+base) equilibria in (n-butylamine+acetic acid) systems in binary (acetone+cyclohexane) solvent mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Czaja, MaIgorzata [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Kozak, Anna [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Makowski, Mariusz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Chmurzynski, Lech [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)]. E-mail: lech@chem.univ.gda.pl

    2005-08-15

    By using the potentiometric titration method, standard equilibrium constants have been determined of acid dissociation of molecular acid, K{sub a}(HA), cationic acid, K{sub a}(BH{sup +}), of anionic and cationic homoconjugation, K{sub AHA{sup -}}andK{sub BHB{sup +}}, respectively, and of molecular heteroconjugation, K{sub AHB} (K{sub BHA}), in (acid+base) systems without proton transfer consisting of n-butylamine and acetic acid in binary (acetone+cyclohexane) solvent mixtures. The results have shown that both the pK{sub a}(HA) and pK{sub a}(BH{sup +}), as well as lgK{sub AHA{sup -}} values change non-linearly as a function of composition of the solvent mixture. On the other hand, standard molecular heteroconjugation constants without proton transfer do not depend on the cyclohexane content in the mixture, i.e. on solvent polarity.

  18. Characterization of PMMA--3-octanone binary by turbidity and light scattering measurements

    OpenAIRE

    Crauste, Caroline; Devailly, Clemence; Steinberger, Audrey; Ciliberto, Sergio

    2013-01-01

    submitted to EPJE; We measure the coexistence curve and the critical point properties of a binary mixture composed by polymethylmethacrylate (PMMA) at $M_w = 55900$ g/mol with 3-~octanone. This binary mixture which has a demixing transition with an upper critical solution temperature $T_c$ has indeed interesting properties which may be useful for several application : a) its correlation length is larger than that of a liquid-liquid binary mixture, b) it is less viscous than a polymer blend; c...

  19. Investigating the discrimination potential of linear and nonlinear spectral multivariate calibrations for analysis of phenolic compounds in their binary and ternary mixtures and calculation pKa values

    Science.gov (United States)

    Rasouli, Zolaikha; Ghavami, Raouf

    2016-08-01

    Vanillin (VA), vanillic acid (VAI) and syringaldehyde (SIA) are important food additives as flavor enhancers. The current study for the first time is devote to the application of partial least square (PLS-1), partial robust M-regression (PRM) and feed forward neural networks (FFNNs) as linear and nonlinear chemometric methods for the simultaneous detection of binary and ternary mixtures of VA, VAI and SIA using data extracted directly from UV-spectra with overlapped peaks of individual analytes. Under the optimum experimental conditions, for each compound a linear calibration was obtained in the concentration range of 0.61-20.99 [LOD = 0.12], 0.67-23.19 [LOD = 0.13] and 0.73-25.12 [LOD = 0.15] μg mL- 1 for VA, VAI and SIA, respectively. Four calibration sets of standard samples were designed by combination of a full and fractional factorial designs with the use of the seven and three levels for each factor for binary and ternary mixtures, respectively. The results of this study reveal that both the methods of PLS-1 and PRM are similar in terms of predict ability each binary mixtures. The resolution of ternary mixture has been accomplished by FFNNs. Multivariate curve resolution-alternating least squares (MCR-ALS) was applied for the description of spectra from the acid-base titration systems each individual compound, i.e. the resolution of the complex overlapping spectra as well as to interpret the extracted spectral and concentration profiles of any pure chemical species identified. Evolving factor analysis (EFA) and singular value decomposition (SVD) were used to distinguish the number of chemical species. Subsequently, their corresponding dissociation constants were derived. Finally, FFNNs has been used to detection active compounds in real and spiked water samples.

  20. Thermophysical properties of binary mixtures of {l_brace}ionic liquid 2-hydroxy ethylammonium acetate + (water, methanol, or ethanol){r_brace}

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Victor H. [School of Chemical Engineering, State University of Campinas (UNICAMP), P.O. Box 6066, 13083-970 Campinas-SP (Brazil); Chemical Engineering Department, ETSE, University of Santiago de Compostela (USC), P.O. Box 15782, Santiago de Compostela (Spain); Mattedi, Silvana [Chemical Engineering Department, Polytechnic School, Federal University of Bahia (UFBA), 40210-630 Salvador-BA (Brazil); Martin-Pastor, Manuel [Unidade de Resonancia Magnetica, RIAIDT, edif. CACTUS, University of Santiago de Compostela (USC), P.O. Box 15706, Santiago de Compostela (Spain); Aznar, Martin [School of Chemical Engineering, State University of Campinas (UNICAMP), P.O. Box 6066, 13083-970 Campinas-SP (Brazil); Iglesias, Miguel, E-mail: miguel.iglesias@usc.es [Chemical Engineering Department, ETSE, University of Santiago de Compostela (USC), P.O. Box 15782, Santiago de Compostela (Spain)

    2011-07-15

    Research highlights: > This paper reports the density and speed of sound data of binary mixtures {l_brace}2-hydroxy ethylammonium acetate + (water, or methanol, or ethanol){r_brace} measured between the temperatures (298.15 and 313.15) K at atmospheric pressure. > The aggregation, dynamic behavior, and hydrogen-bond network were studied using thermo-acoustic, X-ray, and NMR techniques. > The Peng-Robinson equation of state, coupled with the Wong-Sandler mixing rule using the COSMO-SAC model predicted the density of the solutions with relative mean deviations below than 3.0%. - Abstract: In this work, density and speed of sound data of binary mixtures of an ionic liquid consisting of {l_brace}2-hydroxy ethylammonium acetate (2-HEAA) + (water, methanol, or ethanol){r_brace} have been measured throughout the entire concentration range, from the temperature of (288.15 to 323.15) K at atmospheric pressure. The excess molar volumes, variations of the isentropic compressibility, the apparent molar volume, isentropic apparent molar compressibility, and thermal expansion coefficient were calculated from the experimental data. The excess molar volumes were negative throughout the whole composition range. Compressibility data in combination with low angle X-ray scattering and NMR measurements proved that the presence of micelles formed due to ion pair interaction above a critical concentration of the ionic liquid in the mixtures. The Peng-Robinson equation of state coupled with the Wong-Sandler mixing rule and COSMO-SAC model was used to predict densities and the calculated deviations were lower than 3%, for binary mixtures in all composition range.

  1. Spectrophotometric study on the proton transfer reaction between 2-amino-4-methylpyridine with 2,6-dichloro-4-nitrophenol in methanol, acetonitrile and the binary mixture 50% methanol + 50% acetonitrile

    Science.gov (United States)

    Al-Ahmary, Khairia M.; Habeeb, Moustafa M.; Al-Obidan, Areej H.

    2016-02-01

    Proton transfer reaction between 2-amino-4-methylpyridine (2AMP) as the proton acceptor with 2,6-dichloro-4-nitrophenol (DCNP) as the proton donor has been investigated spectrophotometrically in methanol (MeOH), acetonitrile (AN) and a binary mixture composed of 50% MeOH and 50% AN (AN-Me). The composition of the complex has been investigated utilizing Job's and photometric titration methods to be 1:1. Minimum-maximum absorbance equation has been applied to estimate the formation constant of the proton transfer reaction (KPT) where it reached high values in the investigated solvent confirming its high stability. The formation constant recorded higher value in AN compared with MeOH and mixture of AN-Me. Based on the formation of stable proton transfer complex, a sensitive spectrophotometric method was suggested for quantitative determination of 2AMP. The Lambert-Beer's law was obeyed in the concentration range 0.5-8 μg mL- 1 with small values of limits of detection and quantification. The solid complex between 2AMP with DCNP has been synthesized and characterized by elemental analysis to be 1:1 in concordant with the molecular stoichiometry in solution. Further analysis of the solid complex was carried out using infrared and 1H NMR spectroscopy.

  2. Excess molar volumes and dynamic viscosities for binary mixtures of toluene + n-alkanes (C5-C10) at T = 298.15 K - Comparison with Prigogine-Flory-Patterson theory

    International Nuclear Information System (INIS)

    Iloukhani, Hossein; Rezaei-Sameti, Mahdi; Basiri-Parsa, Jalal

    2006-01-01

    Densities ρ, dynamic viscosities η, for binary mixtures of toluene with some n-alkanes, namely, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane have been measured over the complete composition range. Excess molar volumes V E , viscosity deviations Δη, and excess Gibbs free energy of activation ΔG * E , were calculated there from and were correlated by Redlich-Kister type function in terms of mole fractions. For mixtures of toluene with n-pentane and n-hexane the V E is negative and for the remaining systems is positive. The Δη values are negative for all the studied mixtures. The ΔG * E values shows the positive values for the binary mixtures with n-decane, whereas the negative values have been observed for all the remaining binary mixtures. From the results, the excess thermal expansivities at constant pressure α E , is also estimated. The Prigogine-Flory-Patterson (PFP) theory and its applicability in predicting V E is tested. The results obtained for viscosity of binary mixtures were used to test the semi-empirical relations of Grunberg and Nissan, Tamura and Kurata, Hind et al., Katti and Chaudhri, McAllister, Heric, Kendall, and Monroe. The experimental on the constituted binaries are analyzed to discus the nature and strength of intermolecular interactions in these mixtures

  3. CONSOLIDATION AND COMPACTION OF POWDER MIXTURES .3. BINARY-MIXTURES OF DIFFERENT PARTICLE-SIZE FRACTIONS OF DIFFERENT TYPES OF CRYSTALLINE LACTOSE

    NARCIS (Netherlands)

    RIEPMA, KA; ZUURMAN, K; BOLHUIS, GK; DEBOER, AH; LERK, CF

    1992-01-01

    Tablets were compacted from a coarse fraction (250-315 mum), a fine fraction (32-45 mum) and from binary blends of a coarse and a fine fraction of different types of crystalline lactose. The results showed differences in consolidation and compaction between the granular lactose types, i.e.,

  4. Enhanced repellency of binary mixtures of Calophyllum inophyllum nut oil fatty acids or their esters and three terpenoids to Stomoxys calcitrans.

    Science.gov (United States)

    Hieu, Tran Trung; Choi, Won Sil; Kim, Soon-Il; Wang, Mo; Ahn, Young-Joon

    2015-09-01

    An assessment was made of the repellency to female stable flies of tamanu nut oil fatty acids or their esters alone (each 0.5 mg cm(-2) ) or in combination with cuminyl alcohol, cuminaldehyde and α-phellandrene (each 0.25 mg cm(-2) ), using an exposed human hand bioassay. Results were compared with those of synthetic repellent DEET (0.25 mg cm(-2) ). Based upon protection time (PT) (time to first bite of stable fly), oleic acid, linoleic acid, methyl oleate or methyl linoleate synergised the repellency of each monoterpenoid and DEET. For example, the binary mixture of oleic acid and cuminyl alcohol (PT 2.05 h) resulted in significantly greater repellency than either oleic acid (0.55 h), cuminyl alcohol (0.70 h) or DEET alone (1.50 h). The binary mixtures of oleic acid and cuminyl alcohol or DEET (PT 2.10 h) did not differ significantly in repellency. The structure-activity relationship indicates that the degree of saturation, the side chain length and the functional group of fatty acids appear to play a role in determining the fatty acid repellency to stable flies. Mixtures formulated from fatty acid and monoterpenoid could be useful as potential repellents for protecting humans and possibly domestic animals from bites caused by stable fly. © 2014 Society of Chemical Industry.

  5. Study of molecular interactions in binary liquid mixtures of 1-octanol with n-hexane, n-octane, and n-decane using volumetric, viscometric, and acoustic properties

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Gyan P. [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India)], E-mail: gyan.dubey@rediffmail.com; Sharma, Monika [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India)], E-mail: monika.phd906@gmail.com

    2008-06-15

    Experimental values of densities ({rho}) and speeds of sound (u) at T = (298.15, 303.15, and 308.15) K while the viscosities ({eta}) at T = 298.15 K in the binary mixtures of 1-octanol with n-hexane, n-octane, and n-decane are presented over the entire composition range of the binary mixtures. Using these data, excess molar volumes (V{sub m}{sup E}), viscosity deviation ({delta}{eta}), deviation in speeds of sound ({delta}u), deviation in isentropic compressibility ({delta}{kappa}{sub s}), excess free volume (V{sub f}{sup E}), and excess Gibbs free energy of activation of viscous flow ({delta}G*{sup E}) are calculated and presented graphically. All the computed quantities are fitted to a polynomial equation. The values of V{sub m}{sup E} have been analyzed using Prigogine-Flory-Patterson (PFP) theory. Furthermore, the theoretical values of speed of sound (u) and isentropic compressibility ({kappa}{sub s}) have also been estimated using the Prigogine-Flory-Patterson (PFP) theory with the van der Waals (vdW) potential energy model and the results have been compared with experimental values. The experimental and calculated quantities are used to study the nature of mixing behaviour between the mixture components.

  6. Thermophysical properties of the binary mixtures (1,8-cineole + 1-alkanol) at T = (298.15 and 313.15) K and at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Alfaro, P.; Langa, E.; Martinez-Lopez, J.F.; Urieta, J.S. [Aragon Institute of Engineering Research (I3A, University of Zaragoza), 50009-Zaragoza (Spain); Mainar, A.M., E-mail: ammainar@unizar.e [Aragon Institute of Engineering Research (I3A, University of Zaragoza), 50009-Zaragoza (Spain)

    2010-02-15

    This work presents the measurements of the density, speed of sound, refractive index and enthalpy of binary mixtures containing left brace1,8-cineole + 1-alkanol (ethanol, 1-propanol, 1-butanol, and 1-pentanol)right brace at two temperatures (298.15 and 313.15) K and atmospheric pressure. The determination of excess molar volume, speed of sound deviation, refractive index deviation, molar refraction, molar refraction deviation, excess isentropic compressibility, and excess molar enthalpy are also given. Redlich-Kister equation was used to fit these derivate properties. The experimental data of the constituent binaries were analysed to discuss the nature and strengths of intermolecular interactions. Eventually some models, SAFT and PC-SAFT for density, Free Length and Collision Factor for speed of sound, Gladstone-Dale Arago-Biot for refractive index, and UNIFAC for excess molar enthalpy, among others, were successfully applied.

  7. Measurement and correlation of solubility of xylitol in binary water+ethanol solvent mixtures between 278.00 K and 323.00K

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhanzhong; Wang, Qian; Liu, Xiangshan; Fang, Wenzhi; Li, Yan; Xiao, Huazhi [Tianjin University, Tianjin (China)

    2013-04-15

    The solubility of xylitol in ethanol+water solvent mixtures was measured at temperatures ranging from 278.00 K to 323.00 K at atmospheric pressure by using a laser technique. The results of these measurements were correlated by the combined nearly ideal binary solvent CNIBS/Redlich-Kister equation. The experimental solubility and correlation equation in this work can be used as essential data and models in the purification process of xylitol. The variant 2 in the CNIBS/R-K models was confirmed to be more adaptable to predict solubility of xylitol in binary ethanol+water system. Using the experimentally measured solubilities, the thermodynamic properties of dissolution of xylitol, such as Gibbs energy, molar enthalpy of dissolution, and molar entropy of dissolution, were calculated.

  8. Analysis of binary mixtures of aqueous aromatic hydrocarbons with low-phase-noise shear-horizontal surface acoustic wave sensors using multielectrode transducer designs.

    Science.gov (United States)

    Bender, Florian; Mohler, Rachel E; Ricco, Antonio J; Josse, Fabien

    2014-11-18

    The present work investigates a compact sensor system that provides rapid, real-time, in situ measurements of the identities and concentrations of aromatic hydrocarbons at parts-per-billion concentrations in water through the combined use of kinetic and thermodynamic response parameters. The system uses shear-horizontal surface acoustic wave (SH-SAW) sensors operating directly in the liquid phase. The 103 MHz SAW sensors are coated with thin sorbent polymer films to provide the appropriate limits of detection as well as partial selectivity for the analytes of interest, the BTEX compounds (benzene, toluene, ethylbenzene, and xylenes), which are common indicators of fuel and oil accidental releases in groundwater. Particular emphasis is placed on benzene, a known carcinogen and the most challenging BTEX analyte with regard to both regulated levels and its solubility properties. To demonstrate the identification and quantification of individual compounds in multicomponent aqueous samples, responses to binary mixtures of benzene with toluene as well as ethylbenzene were characterized at concentrations below 1 ppm (1 mg/L). The use of both thermodynamic and kinetic (i.e., steady-state and transient) responses from a single polymer-coated SH-SAW sensor enabled identification and quantification of the two BTEX compounds in binary mixtures in aqueous solution. The signal-to-noise ratio was improved, resulting in lower limits of detection and improved identification at low concentrations, by designing and implementing a type of multielectrode transducer pattern, not previously reported for chemical sensor applications. The design significantly reduces signal distortion and root-mean-square (RMS) phase noise by minimizing acoustic wave reflections from electrode edges, thus enabling limits of detection for BTEX analytes of 9-83 ppb (calculated from RMS noise); concentrations of benzene in water as low as ~100 ppb were measured directly. Reliable quantification of BTEX

  9. Studies on thermo-acoustic parameters in binary liquid mixtures of phosphinic acid (Cyanex 272) with different diluents at temperature 303.15 K: an ultrasonic study

    International Nuclear Information System (INIS)

    Kamila, Susmita; Jena, Satyaban; Swain, Bipin Bihari

    2005-01-01

    Acoustical investigations for the binary mixtures of phosphinic acid (Cyanex 272), used as liquid-liquid extractant, have been made in various diluents such as benzene, toluene, and xylene from ultrasonic velocity and density measurements at temperature 303.15 K and atmospheric pressure. This study involves evaluation of different thermo-acoustic parameters along with the excess properties, which are interpreted in the light of molecular interaction between a polar extractant, Cyanex 272 with non-polar diluent, benzene and weakly polar diluents, toluene and xylene. The excess values are correlated using Redlich-Kister polynomial equation, and corresponding adjustable parameters are derived

  10. Separation of americium(III) and europium(III) from nitrate medium using a binary mixture of Cyanex-301 with neutral donor ligands

    International Nuclear Information System (INIS)

    Bhattacharyya, A.; Mohapatra, P.K.; Manchanda, V.K.

    2005-01-01

    Separation behaviour of Am 3+ and Eu 3+ was investigated from aqueous nitrate medium using a binary mixture of Cyanex-301 (bis(2,4,4- trimethylpentyl) dithiophosphinic acid) and several N, O or S donor ligands such as 1,10-phenanthroline (phen), TPTZ (2,4,6- tri(2-pyridyl)- 1,3,5- triazine), 2,2'-bipyridyl(bipy), hexa thia 18 crown 6 (S 6 18C6), TBP (tri-n-butyl phosphate), TBTP (tri-n-butyl thiophosphate) in toluene. The S.F. values of >40,000 obtained with bipy and phen are the highest reported to date. (author)

  11. Theoritical Evaluation of Ultrasonic Velocities in Binary Liquid Mixtures of N-Methyl-2-pyrrolidone at Different Temperatures with Some Cyclic Compounds

    Directory of Open Access Journals (Sweden)

    K. Rayapa Reddy

    2012-01-01

    Full Text Available Ultrasonic velocities and densities of the binary liquid mixtures of N-methyl-2-Pyrrolidone (NMP with Cyclohexylamine (CHA, Cyclohexanol (CHOL and Cyclohexene(CHE at a temperature range of 303.15 to 318.15 K over the entire composition range were measured. The theoretical values of ultrasonic velocity were evaluated using the Nomoto's relation(UNR, Impedence relation(UIR, Ideal mixing relation(UIMR, Jungie's relation(UJR and Rao's specific velocity relation(UR.The molecular interaction parameter (α was computed by using the experimental and theoretical ultrasonic velocity values. The variation of interaction parameter with the composition of the mixture has been discussed in terms of molecular interactions.

  12. Studies on thermodynamic properties of binary mixtures of hexan-1-ol with halogenated compounds at T = (308.15 and 313.15) K

    International Nuclear Information System (INIS)

    Bhatia, Subhash C.; Bhatia, Rachna; Dubey, Gyan P.

    2009-01-01

    Densities, ρ, and ultrasonic velocities, u of binary mixtures of hexan-1-ol with 1,2-dichloroethane, 1,2-dibromoethane, and 1,1,2,2-tetrachloroethene have been measured over the entire range of composition and temperature at (308.15 and 313.15) K. From these experimental results, the excess molar volumes, V E , excess molar isentropic compressibility, K S,m E , molar free volumes, V f , intermolecular free lengths, L f , mean molecular radii, r, Beyer's parameters of non-linearity, B/A, and limiting excess partial molar volumes, V-bar i E,0 , have been estimated. The excess functions have been fitted to the Redlich-Kister polynomial equations. The experimental ultrasonic velocities have been analyzed in terms of Nomoto's relation, Van Dael's ideal mixture relation, Jacobson's free length theory, Schaaffs collision factor theory and thermoacoustical parameters.

  13. Thermophysical and sonochemical behaviour of binary mixtures of decan-1-ol with halohydrocarbons at (T = 293.15 and 313.15) K

    International Nuclear Information System (INIS)

    Bhatia, Subhash C.; Bhatia, Rachna; Dubey, Gyan P.

    2010-01-01

    Densities and ultrasonic velocities of binary mixtures of decan-1-ol with 1,2-dichloroethane, 1,2-dibromoethane, and 1,1,2,2-tetrachloroethene have been measured over the entire range of composition at T = (293.15 and 313.15) K and at atmospheric pressure. From these results, the excess molar volumes, molar free volumes, excess molar isentropic compressibilities, limiting excess partial molar volumes, and isentropic compressibilities, intermolecular free lengths, and available volumes by three methods, thermal expansion coefficients, parameters related to space-filling ability, intermolecular free lengths, and molecular radii have been calculated. The experimental ultrasonic velocities have been analyzed in terms of the ideal mixture relations of Nomoto and Van Dael, Jacobson's free length, Schaaff's collision factor, Flory's statistical, and Prigogine-Flory-Patterson theories and thermoacoustical parameters.

  14. Thermophysical and sonochemical behaviour of binary mixtures of decan-1-ol with halohydrocarbons at (T = 293.15 and 313.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, Subhash C., E-mail: bhatiasc2@rediffmail.co [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India); Bhatia, Rachna, E-mail: bhatiarachna_3@rediffmail.co [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India); Dubey, Gyan P., E-mail: gyan.dubey@rediffmail.co [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India)

    2010-01-15

    Densities and ultrasonic velocities of binary mixtures of decan-1-ol with 1,2-dichloroethane, 1,2-dibromoethane, and 1,1,2,2-tetrachloroethene have been measured over the entire range of composition at T = (293.15 and 313.15) K and at atmospheric pressure. From these results, the excess molar volumes, molar free volumes, excess molar isentropic compressibilities, limiting excess partial molar volumes, and isentropic compressibilities, intermolecular free lengths, and available volumes by three methods, thermal expansion coefficients, parameters related to space-filling ability, intermolecular free lengths, and molecular radii have been calculated. The experimental ultrasonic velocities have been analyzed in terms of the ideal mixture relations of Nomoto and Van Dael, Jacobson's free length, Schaaff's collision factor, Flory's statistical, and Prigogine-Flory-Patterson theories and thermoacoustical parameters.

  15. The influence of hydrogen bonds and preferential solvation on spectroscopic properties of methyl p-dimethylaminobenzoate and its ortho derivative in binary solvent mixture

    Science.gov (United States)

    Józefowicz, Marek

    2011-05-01

    Using the steady-state spectroscopic technique, we have studied the spectroscopic properties of methyl p-dimethylaminobenzoate and its ortho derivative in binary mixture where one of components is capable to form hydrogen bonds with the solute molecules. Non-linear solvatochromic shifts of the absorption, locally excited (LE) and intramolecular charge transfer (ICT) fluorescence bands are observed for both fluorophores. This non-linearity has been explained as due to three main causes: non-ideal behavior of the solvent mixture, specific solute-solvent association, and dielectric enrichment of the solvent around the polar solutes. The results of spectroscopic measurements were used to calculate, according to Mazurenko's, Bakhshiev's and Kiselev's theories, the free energy of the reorientational interaction for a studied molecules, the number of more polar solvent molecules involved in the first solvation shell and the fluorescence spectra of solvates having different number of more polar component in the first solvation shell.

  16. Membrane electrodes for determination of two antihypertensive drugs in pharmaceutical formulations of either single or binary mixtures and in biological fluids.

    Science.gov (United States)

    El-Ghobashy, M R; Zaazaa, H E

    2010-06-01

    Membrane-selective electrodes were used to determine benazepril hydrochloride (BZ) and trandolapril (TR) in their binary mixtures with hydrochlorothiazide (HZ) and verapamil (VR), respectively. This method involves construction of four water insoluble ion-association complexes: benazepril-tetraphenyl borate (BZ-TPB), benazepril-reineckate (BZ-R), trandolapril-tetraphenyl borate (TR-TPB), and trandolapril-reineckate (TR-R). These complexes were used as electroactive materials in polyvinyl chloride (PVC) matrix membrane sensors in order to determine the two aforementioned drugs in their pharmaceutical formulations and in plasma. The performance characteristics of these sensors, evaluated according to IUPAC recommendations, revealed a fast, stable, and linear response for BZ and TR. The suggested procedures were checked using laboratory-prepared mixtures and were successfully used to analyze their pharmaceutical preparations. The results obtained using the proposed method were statistically analyzed and compared with those obtained using previously reported methods.

  17. Use of linear regression for the processing of curves of differential potentiometric titration of a binary mixture of heterovalent ions using precipitation reactions

    International Nuclear Information System (INIS)

    Mar'yanov, B.M.; Zarubin, A.G.; Shumar, S.V.

    2003-01-01

    A method is proposed for the computer processing of curve of differential potentiometric titration of a binary mixture of heterovalent ions using precipitation reactions. The method is based on the transformation of the titration curve to segment-line characteristics, whose parameters (within the accuracy of the least-squares method) determine the sequence of the equivalence points and solubility products of the resulting precipitation. The method is applied to the titration of Ag(I)-Cd)II), Hg(II)-Te(IV), and Cd(II)-Te(IV) mixtures by a sodium diethyldithiocarbamate solution with membrane sulfide and glassy carbon indicator electrodes. For 4 to 11 mg of the analyte in 50 ml of the solution, RSD varies from 1 to 9% [ru

  18. A comparative study of the use of powder X-ray diffraction, Raman and near infrared spectroscopy for quantification of binary polymorphic mixtures of piracetam.

    Science.gov (United States)

    Croker, Denise M; Hennigan, Michelle C; Maher, Anthony; Hu, Yun; Ryder, Alan G; Hodnett, Benjamin K

    2012-04-07

    Diffraction and spectroscopic methods were evaluated for quantitative analysis of binary powder mixtures of FII(6.403) and FIII(6.525) piracetam. The two polymorphs of piracetam could be distinguished using powder X-ray diffraction (PXRD), Raman and near-infrared (NIR) spectroscopy. The results demonstrated that Raman and NIR spectroscopy are most suitable for quantitative analysis of this polymorphic mixture. When the spectra are treated with the combination of multiplicative scatter correction (MSC) and second derivative data pretreatments, the partial least squared (PLS) regression model gave a root mean square error of calibration (RMSEC) of 0.94 and 0.99%, respectively. FIII(6.525) demonstrated some preferred orientation in PXRD analysis, making PXRD the least preferred method of quantification. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Identification of Targets of a New Nutritional Mixture for Osteoarthritis Management Composed by Curcuminoids Extract, Hydrolyzed Collagen and Green Tea Extract.

    Directory of Open Access Journals (Sweden)

    Fanny Comblain

    Full Text Available We have previously demonstrated that a mixture of curcuminoids extract, hydrolyzed collagen and green tea extract (COT inhibited inflammatory and catabolic mediator's synthesis by osteoarthritic human chondrocytes. The objective of this study was to identify new targets of COT using genomic and proteomic approaches.Cartilage specimens were obtained from 12 patients with knee osteoarthritis. Primary human chondrocytes were cultured in monolayer until confluence and then incubated for 24 or 48 hours in the absence or in the presence of human interleukin(IL-1β (10-11M and with or without COT, each compound at the concentration of 4 μg/ml. Microarray gene expression profiling between control, COT, IL-1β and COT IL-1β conditions was performed. Immunoassays were used to confirm the effect of COT at the protein level.More than 4000 genes were differentially expressed between conditions. The key regulated pathways were related to inflammation, cartilage metabolism and angiogenesis. The IL-1β stimulated chemokine ligand 6, matrix metalloproteinase-13, bone morphogenetic protein-2 and stanniocalcin1 gene expressions and protein productions were down-regulated by COT. COT significantly decreased stanniocalcin1 production in basal condition. Serpin E1 gene expression and protein production were down-regulated by IL-1β. COT reversed the inhibitory effect of IL-1β. Serpin E1 gene expression was up-regulated by COT in control condition.The COT mixture has beneficial effect on osteoarthritis physiopathology by regulating the synthesis of key catabolic, inflammatory and angiogenesis factors. These findings give a scientific rationale for the use of these natural ingredients in the management of osteoarthritis.

  20. Effects of chronic exposure to waterborne copper and nickel in binary mixture on tissue-specific metal accumulation and reproduction in fathead minnow (Pimephales promelas).

    Science.gov (United States)

    Driessnack, Melissa K; Jamwal, Ankur; Niyogi, Som

    2017-10-01

    The current study evaluated the interactive effects of chronic waterborne copper (Cu) and nickel (Ni) exposure on tissue-specific metal accumulation and reproductive performance in fathead minnow (Pimephales promelas). Fish trios (1 male: 2 female; n = 5-6) were exposed for 21 days to: (i) control (no added Cu or Ni), (ii) waterborne Cu (45 μg/L), (iii) waterborne Ni (270 μg/L), and (iv) binary mixture of waterborne Cu and Ni (45 and 270 μg/L, respectively). Fish fecundity (cumulative egg production) was found to be the most sensitive reproductive endpoint, and the interaction of Cu and Ni elicited an additive effect on egg production. Tissue-specific accumulation of both metals was not influenced by the interaction of Cu and Ni, except an increased Cu and Ni burden in the carcass and ovary, respectively, were recorded. The expressions of hepatic estrogen receptor genes (ER-α and ER-β) and the circulating estradiol level in females were also not affected by the metal-mixture treatment. However, co-exposure to waterborne Cu and Ni resulted in a significant downregulation of the hepatic vitellogenin gene in females, which was associated with the maximum upregulation of the hepatic metallothionein gene. In addition, a significant alteration of ovarian histopathology (decreased abundance of post-vitellogenic follicles, and increased follicular atresia) was also observed only in females exposed to Cu and Ni in mixture. Collectively, these observations suggest that chronic waterborne exposure to Cu and Ni in binary mixture may impair fish reproductive capacity by inducing histopathological damage in ovarian tissue, and disrupting of energy homeostasis in fish. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Molecular dynamics simulation for the test of calibrated OPLS-AA force field for binary liquid mixture of tri-iso-amyl phosphate and n-dodecane

    Science.gov (United States)

    Das, Arya; Ali, Sk. Musharaf

    2018-02-01

    Tri-isoamyl phosphate (TiAP) has been proposed to be an alternative for tri-butyl phosphate (TBP) in the Plutonium Uranium Extraction (PUREX) process. Recently, we have successfully calibrated and tested all-atom optimized potentials for liquid simulations using Mulliken partial charges for pure TiAP, TBP, and dodecane by performing molecular dynamics (MD) simulation. It is of immense importance to extend this potential for the various molecular properties of TiAP and TiAP/n-dodecane binary mixtures using MD simulation. Earlier, efforts were devoted to find out a suitable force field which can explain both structural and dynamical properties by empirical parameterization. Therefore, the present MD study reports the structural, dynamical, and thermodynamical properties with different mole fractions of TiAP-dodecane mixtures at the entire range of mole fraction of 0-1 employing our calibrated Mulliken embedded optimized potentials for liquid simulation (OPLS) force field. The calculated electric dipole moment of TiAP was seen to be almost unaffected by the TiAP concentration in the dodecane diluent. The calculated liquid densities of the TiAP-dodecane mixture are in good agreement with the experimental data. The mixture densities at different temperatures are also studied which was found to be reduced with temperature as expected. The plot of diffusivities for TiAP and dodecane against mole fraction in the binary mixture intersects at a composition in the range of 25%-30% of TiAP in dodecane, which is very much closer to the TBP/n-dodecane composition used in the PUREX process. The excess volume of mixing was found to be positive for the entire range of mole fraction and the excess enthalpy of mixing was shown to be endothermic for the TBP/n-dodecane mixture as well as TiAP/n-dodecane mixture as reported experimentally. The spatial pair correlation functions are evaluated between TiAP-TiAP and TiAP-dodecane molecules. Further, shear viscosity has been computed by

  2. A predictive method for crude oil volatile organic compounds emission from soil: evaporation and diffusion behavior investigation of binary gas mixtures.

    Science.gov (United States)

    Wang, Haijing; Fischer, Thomas; Wieprecht, Wolfgang; Möller, Detlev

    2015-05-01

    Due to their mobility and toxicity, crude oil volatile organic compounds (VOCs) are representative components for oil pipeline contaminated sites detection. Therefore, contaminated location risk assessment, with airborne light detection and ranging (LIDAR) survey, in particular, requires ground-based determinative methods for oil VOCs, the interaction between oil VOCs and soil, and information on how they diffuse from underground into atmosphere. First, we developed a method for determination of crude oil VOC binary mixtures (take n-pentane and n-hexane as examples), taking synergistic effects of VOC mixtures on polydimethylsiloxane (PDMS) solid-phase microextraction (SPME) fibers into consideration. Using this method, we further aim to extract VOCs from small volumes, for example, from soil pores, using a custom-made sampling device for nondestructive SPME fiber intrusion, and to study VOC transport through heterogeneous porous media. Second, specific surface Brunauer-Emmett-Teller (BET) analysis was conducted and used for estimation of VOC isotherm parameters in soil. Finally, two models were fitted for VOC emission prediction, and the results were compared to the experimental emission results. It was found that free diffusion mode worked well, and an empirical correction factor seems to be needed for the other model to adapt to our condition for single and binary systems.

  3. Vapor pressures and activity coefficients of binary mixtures of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide with acetonitrile and tetrahydrofuran

    International Nuclear Information System (INIS)

    Safarov, Javid; Geppert-Rybczyńska, Monika; Hassel, Egon; Heintz, Andreas

    2012-01-01

    Highlights: ► A new apparatus for the determination of VLE is presented. ► The first vapor pressures for binary mixtures containing aprotic solvents in IL are reported. ► Calculated activity coefficients and osmotic coefficients reveal a strong non-ideal behavior. ► A more detailed study of the highly diluted IL concentration range is necessary to test the Debye–Hückel law. - Abstract: A new apparatus for the determination of VLE has been constructed which works for absolute pressure measurements as well as for measuring differential pressures. The first results obtained are (vapor + liquid) equilibria (VLE) of binary mixtures containing acetonitrile or tetrahydrofuran and the ionic liquid (IL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIm][NTf2] by using the absolute pressures method. VLE measurements were carried out over the whole concentration range at four different temperatures between 293.15 K and 313.15 K. Activity coefficients (γ 1 ) of the solvents in [EMIm][NTf2] and their osmotic coefficients (φ 1 ) have been determined from the VLE data.

  4. Excess molar volume along with viscosity, refractive index and relative permittivity for binary mixtures of exo-tetrahydrodicyclopentadiene with four octane isomers

    International Nuclear Information System (INIS)

    Yue, Lei; Qin, Xiaomei; Wu, Xi; Xu, Li; Guo, Yongsheng; Fang, Wenjun

    2015-01-01

    Highlights: • Binary mixtures of JP-10 with octane isomers are studied as model hydrocarbon fuels. • Density, viscosity, refractive index and relative permittivity are determined. • Excess molar volumes and viscosity deviations are calculated and correlated. - Abstract: The fundamental physical properties including density, viscosity, refractive index and relative permittivity, have been measured for binary mixtures of exo-tetrahydrodicyclopentadiene (JP-10) with four octane isomers (n-octane, 3-methylheptane, 2,4-dimethylhexane and 2,2,4-trimethylpentane) over the whole composition range at temperatures T = (293.15 to 313.15) K and pressure p = 0.1 MPa. The values of excess molar volume (V m E ), viscosity deviation (Δη), refractive index deviation (Δn D ) and relative permittivity deviation (Δε r ) are then calculated. All of the values of V m E and Δη are observed to be negative, while those of Δn D and Δε r are close to zero. The effects of temperature and composition on the variation of V m E values are discussed. The negative values of V m E and Δη are conductive to high-density and low-resistance of fuels, which is favorable for the design and preparation of advanced hydrocarbon fuels

  5. Calculation of partition functions and free energies of a binary mixture using the energy partitioning method: application to carbon dioxide and methane.

    Science.gov (United States)

    Do, Hainam; Hirst, Jonathan D; Wheatley, Richard J

    2012-04-19

    It is challenging to compute the partition function (Q) for systems with enormous configurational spaces, such as fluids. Recently, we developed a Monte Carlo technique (an energy partitioning method) for computing Q [ J. Chem. Phys. 2011 , 135 , 174105 ]. In this paper, we use this approach to compute the partition function of a binary fluid mixture (carbon dioxide + methane); this allows us to obtain the Helmholtz free energy (F) via F = -k(B)T ln Q and the Gibbs free energy (G) via G = F + pV. We then utilize G to obtain the coexisting mole fraction curves. The chemical potential of each species is also obtained. At the vapor-liquid equilibrium condition, the chemical potential of methane significantly increases, while that of carbon dioxide slightly decreases, as the pressure increases along an isotherm. Since Q is obtained from the density of states, which is independent of the temperature, equilibrium thermodynamic properties at any condition can be obtained by varying the total composition and volume of the system. Our methodology can be adapted to explore the free energies of other binary mixtures in general and of those containing CO(2) in particular. Since the method gives access to the free energy and chemical potentials, it will be useful in many other applications.

  6. Structure-retention and mobile phase-retention relationships for reversed-phase high-performance liquid chromatography of several hydroxythioxanthone derivatives in binary acetonitrile-water mixtures

    International Nuclear Information System (INIS)

    Amiri, Ali Asghar; Hemmateenejad, Bahram; Safavi, Afsaneh; Sharghi, Hashem; Beni, Ali Reza Salimi; Shamsipur, Mojtaba

    2007-01-01

    The reversed-phase high-performance liquid chromatographic (RP-HPLC) behavior of some newly synthesized hydroxythioxanthone derivatives using binary acetonitrile-water mixtures as mobile phase has been examined. First, the variation in the retention time of each molecule as a function of mobile phase properties was studied by Kamlet-Taft solvatochromic equations. Then, the influences of molecular structure of the hydroxythioxanthone derivatives on their retention time in various mobile phase mixtures were investigated by quantitative structure-property relationship (QSPR) analysis. Finally, a unified model containing both the molecular structure parameters and mobile phase properties was developed to describe the chromatographic behavior of the systems studied. Among the solvent properties, polarity/polarizability parameter (π * ) and hydrogen-bond basicity (β), and among the solute properties, the most positive local charge (MPC), the sum of positive charges on hydrogen atoms contributing in hydrogen bonding (SPCH) and lipophilicity index (log P) were identified as controlling factors in the RP-HPLC behavior of hydroxythioxanthone derivatives in actonitrile-water binary solvents

  7. Binary, ternary and quaternary liquid-liquid equilibria in 1-butanol, oleic acid, water and n-heptane mixtures

    NARCIS (Netherlands)

    Winkelman, J. G. M.; Kraai, G. N.; Heeres, H. J.

    2009-01-01

    This work reports on liquid-liquid equilibria in the system 1-butanol, oleic acid, water and n-heptane used for biphasic, lipase catalysed esterifications. The literature was studied on the mutual solubility in binary systems of water and each of the organic components. Experimental results were

  8. Suitability of binary mixtures of water with aprotic solvents to turn hydroxyl protons of carbohydrate ligands into conformational sensors in NOE and transferred NOE experiments

    International Nuclear Information System (INIS)

    Siebert, Hans-Christian; Andre, Sabine; Vliegenthart, Johannes F.G.; Gabius, Hans-Joachim; Minch, Michael J.

    2003-01-01

    The structural analysis of protein-carbohydrate interactions is essential for the long-range aim to sort out entropic/ enthalpic factors in the binding process. Of conspicuous clinical interest, this work can also offer the perspective to devise new classes of therapeuticals which interfere with disease-related glycan recognition. We have shown that it is possible to use exchangeable hydroxyl protons of carbohydrate ligands as conformational sensors for defining their bound-state topology by measurements in dimethyl sulfoxide d6 (Siebert et al. (2000) ChemBioChem, 1, 181-195). However, the proteins are required to maintain binding capacity in the aprotic solvent. To define conditions to limit its harmful effect on sensitive protein structures while still being able to pick up solvent-exchangeable hydroxyl signals we systematically tested binary solvent mixtures of dimethyl sulfoxide and acetone with water. These solvent mixtures did not preclude to monitor hydroxyl protons of carbohydrate ligands even at temperatures well above 0 deg. C. Notably, hydrogen bonding of the two tested disaccharides (Galβ1-4Glcα/β and Galα1-3Galα/β or Galα1-3Galβ1-OCH 3 ), which are common lectin ligands, resembled the situation under physiological conditions. Also, a refined topological description for hydroxyl positioning could be achieved for Galα1-3Gal. At least equally important, this approach worked for elucidation of the mistletoe-lectin-bound topology of lactose in its syn-conformation with indication for formation of a characteristic interresidual hydrogen bond. These measurements were performed in a binary dimethyl sulfoxide d6 :water mixture (6:4 ratio, v/v) at -12 deg. C and encourage to pursue this line of investigation by monitoring in the course of stepwise temperature increases. Our experiments reveal that binary mixtures have favorable properties for the conformational analysis of the free- and bound-state topologies of bioactive ligands

  9. Boiling Temperature vs. Composition. An Almost-Exact Explicit Equation for a Binary Mixture Following Raoult's Law.

    Science.gov (United States)

    Cardinali, Mario Emilio; Giomini, Claudio

    1989-01-01

    Proposes a simple procedure based on an expansion of the exponential terms of Raoult's law by applying it to the case of the benzene-toluene mixture. The results with experimental values are presented as a table. (YP)

  10. Theoretical and experimental comparison of the Soret coefficient for water-methanol and water-ethanol binary mixtures

    DEFF Research Database (Denmark)

    Saghir, MZ; Jiang, CG; Derawi, Samer

    2004-01-01

    In multicomponent. mixtures, a much richer variety of phenomena can occur than in Simple (single-component) fluids. Natural convection in single-component. fluids is due to buoyancy forces caused by temperature gradients. In multicomponent mixtures, buoyancy forces may also be caused...... by concentration gradients. Because natural convection, molecular diffusion, and thermal conduction have different relaxation time scales, a wide variety of resulting convective motions and heat, and mass distributions might occur. In some fluid mixtures such as water-ethanol system, for instance, ethanol diffuses...... much more slowly than heat, and because of this difference in time scales oscillatory convection might occur. In a multocomponent mixture, the total molar flux consists of two parts: the convective molar flux and the diffusive molar flux (resulting from the difference between the component, velocity...

  11. Phase diagrams of binary mixtures of patchy colloids with distinct numbers and types of patches: the empty fluid regime.

    Science.gov (United States)

    de las Heras, Daniel; Tavares, José Maria; da Gama, Margarida M Telo

    2011-03-14

    We investigate the effect of distinct bonding energies on the onset of criticality of low functionality fluid mixtures. We focus on mixtures of particles with two and three patches as this includes the mixture where "empty" fluids were originally reported. In addition to the number of patches, the species differ in the type of patches or bonding sites. For simplicity, we consider that the patches on each species are identical: one species has three patches of type A and the other has two patches of type B. We have found a rich phase behavior with closed miscibility gaps, liquid-liquid demixing, and negative azeotropes. Liquid-liquid demixing was found to pre-empt the "empty" fluid regime, of these mixtures, when the AB bonds are weaker than the AA or BB bonds. By contrast, mixtures in this class exhibit "empty" fluid behavior when the AB bonds are stronger than at least one of the other two. Mixtures with bonding energies ε(BB) = ε(AB) and ε(AA) < ε(BB), were found to exhibit an unusual negative azeotrope.

  12. Effects of Monotypic and Binary Mixtures of Metal Oxide Nanoparticles on Microbial Growth in Sandy Soil Collected from Artificial Recharge Sites.

    Science.gov (United States)

    Ko, Kyung-Seok; Ha, Kyoochul; Kong, In Chul

    2015-11-24

    The potential effects of monotypic and binary metal oxide nanoparticles (NPs, ZnO, NiO, Co₃O₄ and TiO₂) on microbial growth were evaluated in sandy soil collected from artificial recharge sites. Microbial growth was assessed based on adenosine triphosphate (ATP) content, dehydrogenase activity (DHA), and viable cell counts (VCC). Microbial growth based on ATP content and VCC showed considerable differences depending on NP type and concentration, whereas DHA did not significantly change. In general, ZnO NPs showed the strongest effect on microbial growth in all measurements, showing an EC50 value of 10.9 mg/L for ATP content. The ranking (EC50) of NPs based on their effect on microbial growth assessed by ATP content and VCC was ZnO > Co₃O₄ > NiO > TiO₂. Upon exposure to binary NP mixtures, synergistic and additive modes of action were observed for ATP content and VCC, respectively. The ranges of observed (P(O)) and expected (P(E)) activity were 83%-92% and 78%-82% of the control (p-value 0.0010) based on ATP content and 78%-95% and 72%-94% of the control (p-value 0.8813) based on VCC under the tested conditions, respectively. The results indicate that the effects of NP mixtures on microbial growth in the sandy soil matrix were as great, or greater, than those of single NPs. Therefore, understanding the effects of single NPs and NP mixtures is essential for proper ecological risk assessment. Additionally, these findings demonstrate that the evaluation of NP effects may be profoundly influenced by the method of microbial growth measurement.

  13. Effect of clay content and mineralogy on frictional sliding behavior of simulated gouges: binary and ternary mixtures of quartz, illite, and montmorillonite

    Science.gov (United States)

    Tembe, Sheryl; Lockner, David A.; Wong, Teng-Fong

    2010-01-01

    We investigated the frictional sliding behavior of simulated quartz-clay gouges under stress conditions relevant to seismogenic depths. Conventional triaxial compression tests were conducted at 40 MPa effective normal stress on saturated saw cut samples containing binary and ternary mixtures of quartz, montmorillonite, and illite. In all cases, frictional strengths of mixtures fall between the end-members of pure quartz (strongest) and clay (weakest). The overall trend was a decrease in strength with increasing clay content. In the illite/quartz mixture the trend was nearly linear, while in the montmorillonite mixtures a sigmoidal trend with three strength regimes was noted. Microstructural observations were performed on the deformed samples to characterize the geometric attributes of shear localization within the gouge layers. Two micromechanical models were used to analyze the critical clay fractions for the two-regime transitions on the basis of clay porosity and packing of the quartz grains. The transition from regime 1 (high strength) to 2 (intermediate strength) is associated with the shift from a stress-supporting framework of quartz grains to a clay matrix embedded with disperse quartz grains, manifested by the development of P-foliation and reduction in Riedel shear angle. The transition from regime 2 (intermediate strength) to 3 (low strength) is attributed to the development of shear localization in the clay matrix, occurring only when the neighboring layers of quartz grains are separated by a critical clay thickness. Our mixture data relating strength degradation to clay content agree well with strengths of natural shear zone materials obtained from scientific deep drilling projects.

  14. Transcriptomics analysis of interactive effects of benzene, trichloroethylene and methyl mercury within binary and ternary mixtures on the liver and kidney following subchronic exposure in the rat

    International Nuclear Information System (INIS)

    Hendriksen, Peter J.M.; Freidig, Andreas P.; Jonker, Diana; Thissen, Uwe; Bogaards, Jan J.P.; Mumtaz, Moiz M.; Groten, John P.; Stierum, Rob H.

    2007-01-01

    The present research aimed to study the interaction of three chemicals, methyl mercury, benzene and trichloroethylene, on mRNA expression alterations in rat liver and kidney measured by microarray analysis. These compounds were selected based on presumed different modes of action. The chemicals were administered daily for 14 days at the Lowest-Observed-Adverse-Effect-Level (LOAEL) or at a two- or threefold lower concentration individually or in binary or ternary mixtures. The compounds had strong antagonistic effects on each other's gene expression changes, which included several genes encoding Phase I and II metabolizing enzymes. On the other hand, the mixtures affected the expression of 'novel' genes that were not or little affected by the individual compounds. The three compounds exhibited a synergistic interaction on gene expression changes at the LOAEL in the liver and both at the sub-LOAEL and LOAEL in the kidney. Many of the genes induced by mixtures but not by single compounds, such as Id2, Nr2f6, Tnfrsf1a, Ccng1, Mdm2 and Nfkb1 in the liver, are known to affect cellular proliferation, apoptosis and tissue-specific function. This indicates a shift from compound specific response on exposure to individual compounds to a more generic stress response to mixtures. Most of the effects on cell viability as concluded from transcriptomics were not detected by classical toxicological endpoints illustrating the benefit of increased sensitivity of assessing gene expression profiling. These results emphasize the benefit of applying toxicogenomics in mixture interaction studies, which yields biomarkers for joint toxicity and eventually can result in an interaction model for most known toxicants

  15. Stability indicating HPLC-DAD method for analysis of Ketorolac binary and ternary mixtures in eye drops: Quantitative analysis in rabbit aqueous humor.

    Science.gov (United States)

    El Yazbi, Fawzy A; Hassan, Ekram M; Khamis, Essam F; Ragab, Marwa A A; Hamdy, Mohamed M A

    2017-11-15

    Ketorolac tromethamine (KTC) with phenylephrine hydrochloride (PHE) binary mixture (mixture 1) and their ternary mixture with chlorpheniramine maleate (CPM) (mixture 2) were analyzed using a validated HPLC-DAD method. The developed method was suitable for the in vitro as well as quantitative analysis of the targeted mixtures in rabbit aqueous humor. The analysis in dosage form (eye drops) was a stability indicating one at which drugs were separated from possible degradation products arising from different stress conditions (in vitro analysis). For analysis in aqueous humor, Guaifenesin (GUF) was used as internal standard and the method was validated according to FDA regulation for analysis in biological fluids. Agilent 5 HC-C18(2) 150×4.6mm was used as stationary phase with a gradient eluting solvent of 20mM phosphate buffer pH 4.6 containing 0.2% triethylamine and acetonitrile. The drugs were resolved with retention times of 2.41, 5.26, 7.92 and 9.64min for PHE, GUF, KTC and CPM, respectively. The method was sensitive and selective to analyze simultaneously the three drugs in presence of possible forced degradation products and dosage form excipients (in vitro analysis) and also with the internal standard, in presence of aqueous humor interferences (analysis in biological fluid), at a single wavelength (261nm). No extraction procedure was required for analysis in aqueous humor. The simplicity of the method emphasizes its capability to analyze the drugs in vivo (in rabbit aqueous humor) and in vitro (in pharmaceutical formulations). Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Toxicities of four anti-neoplastic drugs and their binary mixtures tested on the green alga Pseudokirchneriella subcapitata and the cyanobacterium Synechococcus leopoliensis.

    Science.gov (United States)

    Brezovšek, Polona; Eleršek, Tina; Filipič, Metka

    2014-04-01

    The residues of anti-neoplastic drugs are new and emerging pollutants in aquatic environments. This is not only because of their increasing use, but also because due to their mechanisms of action, they belong to a group of particularly dangerous compounds. However, information on their ecotoxicological properties is very limited. We tested the toxicities of four anti-neoplastic drugs with different mechanisms of action (5-fluorouracil [5-FU], cisplatin [CDDP], etoposide [ET], and imatinib mesylate [IM]), and some of their binary mixtures, against two phytoplankton species: the alga Pseudokirchneriella subcapitata, and the cyanobacterium Synechococcus leopoliensis. These four drugs showed different toxic potential, and the two species examined also showed differences in their susceptibilities towards the tested drugs and their mixtures. With P. subcapitata, the most toxic of these drugs was 5-FU (EC50, 0.13 mg/L), followed by CDDP (EC50, 1.52 mg/L), IM (EC50, 2.29 mg/L), and the least toxic, ET (EC50, 30.43 mg/L). With S. leopoliensis, the most toxic was CDDP (EC50, 0.67 mg/L), followed by 5-FU (EC50, 1.20 mg/L) and IM (EC50, 5.36 mg/L), while ET was not toxic up to 351 mg/L. The toxicities of the binary mixtures tested (5-FU + CDDP, 5-FU + IM, CDDP + ET) were predicted by the concepts of 'concentration addition' and 'independent action', and are compared to the experimentally determined toxicities. The measured toxicity of 5-FU + CDDP with P. subcapitata and S. leopoliensis was higher than that predicted, while the measured toxicity of CDDP + ET with both species was lower than that predicted. The measured toxicity of 5-FU + IM with P. subcapitata was higher, and with S. leopoliensis was lower, than that predicted. These data show that these mixtures can have compound-specific and species-specific synergistic or antagonistic effects, and they suggest that single compound toxicity data are not sufficient for the prediction of the aquatic

  17. Central Composite Design (CCD) applied for statistical optimization of glucose and sucrose binary carbon mixture in enhancing the denitrification process

    Science.gov (United States)

    Lim, Jun-Wei; Beh, Hoe-Guan; Ching, Dennis Ling Chuan; Ho, Yeek-Chia; Baloo, Lavania; Bashir, Mohammed J. K.; Wee, Seng-Kew

    2017-11-01

    The present study provides an insight into the optimization of a glucose and sucrose mixture to enhance the denitrification process. Central Composite Design was applied to design the batch experiments with the factors of glucose and sucrose measured as carbon-to-nitrogen (C:N) ratio each and the response of percentage removal of nitrate-nitrogen (NO3 --N). Results showed that the polynomial regression model of NO3 --N removal had been successfully derived, capable of describing the interactive relationships of glucose and sucrose mixture that influenced the denitrification process. Furthermore, the presence of glucose was noticed to have more consequential effect on NO3 --N removal as opposed to sucrose. The optimum carbon sources mixture to achieve complete removal of NO3 --N required lesser glucose (C:N ratio of 1.0:1.0) than sucrose (C:N ratio of 2.4:1.0). At the optimum glucose and sucrose mixture, the activated sludge showed faster acclimation towards glucose used to perform the denitrification process. Later upon the acclimation with sucrose, the glucose uptake rate by the activated sludge abated. Therefore, it is vital to optimize the added carbon sources mixture to ensure the rapid and complete removal of NO3 --N via the denitrification process.

  18. Physical chemical characterization of binary mixtures of biodiesel and diesel commercialized in Amazonas; Caracterizacao fisico-quimica das misturas binarias de biodiesel e diesel comercializados no Amazonas

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Cristiane Daliassi Ramos de; Chaar, Jamal da Silva; Souza, Katiuscia dos Santos de; Costa, Everton Jose Cardoso; Santos, Josana Coria dos [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Lab. de Pesquisas e Ensaios de Combustiveis (LAPEC)], e-mail: cdaliassi@yahoo.com.br, e-mail: jchaar@ufam.edu.br, e-mail: katy_souza@yahoo.com.br, e-mail: costaejc@bol.com.br, e-mail: josanacoria@gmail.com; Souza, Rubem Cesar Rodrigues; Jeffreys, Manoel Feitosa [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Centro de Desenvolvimento Energetico Amazonico (CDEAM)], e-mail: cdaliassi@yahoo.com.br, e-mail: rubem_souza@yahoo.com.br, e-mail: manoel_jeffreys@hotmail.com

    2009-06-15

    The use of renewable energies allied to the preservation of the environment has awakening more and more interest on the national and international level, especially the utilization of biodiesel in substitution of petroleum diesel. Its use brings a series of social, economical and environmental advantages. In the last few years, there has been an increase in biodiesel research in Brazil. The Brasilian law no. 11.097 of 2005 proposes the introduction of biodiesel in the Brazilian energetic matrix, mixing it with diesel oil at an obligatory percentile minimum of 2%, with an increase of 5% in the addition, until 2012. However, the addition is only permitted if the biodiesel is within the quality patterns demanded. Before this, mixtures of biodiesel added to interior diesel were prepared, in proportions of 2, 5, 10 and 20% (v/v), which were later characterized, as of the physical chemical parameters determined in the Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP) Resolution for evaluating mixtures in accordance with the norm. The results show that, biodiesel as well as their binary mixtures (B2 to B20) are within the quality patterns established by the ANP. (author)

  19. Volumetric properties of binary liquid mixtures: Application of the Prigogine-Flory-Patterson theory to excess molar volumes of dichloromethane with benzene or toluene

    International Nuclear Information System (INIS)

    Sun Yuping; Su Liyan; Wang Haijun

    2009-01-01

    The values of the density were measured for binary liquid mixtures of benzene and toluene with dichloromethane over entire range of concentration using a vibrating-tube densimeter at T = (288.15, 293.15, 298.15, and 303.15) K and atmospheric pressure. The excess molar volumes, calculated from the density results, are positive for the systems of dichloromethane with benzene over the whole concentration range and present an approximate sigmoid curve for the dichloromethane with toluene. The V m E values have been fitted to the Redlich-Kister polynomial equation, and other volumetric properties such as the partial molar volumes, V i -bar, the apparent molar volume, V φi , and the partial molar excess volumes at infinite dilution, (V i E -bar) ∞ , were calculated over the whole composition range. The Prigogine-Flory-Patterson (PFP) theory and its applicability in predicting V m E at T = 298.15 K are tested. Good agreement was found for the mixtures dichloromethane with benzene. For the mixtures dichloromethane with toluene, which shows an approximate S-shaped V m E behaviour, the correlation fails.

  20. Thermodynamic properties of biofuels: Heat capacities of binary mixtures containing ethanol and hydrocarbons up to 20 MPa and the pure compounds using a new flow calorimeter

    International Nuclear Information System (INIS)

    Vega-Maza, David; Segovia, Jose J.; Carmen Martin, M.; Villamanan, Rosa M.; Villamanan, Miguel A.

    2011-01-01

    Highlights: → Isobaric heat capacities for heptane, ethanol, and the mixtures of ethanol with heptane and toluene are reported. → They have been measured at 5 pressures over the range (0 to 20) MPa. → An automated flow calorimeter has been developed for the measurements. → The experimental data are fitted to Redlich-Kister equations. → Excess isobaric heat capacities are calculated. - Abstract: Heat capacities are of great significance in the design of new processes and the improvement of existing ones in R and D in production plants as well as the adaptation of new products, in this case, biofuels to their use in a variety of engines and technical devices. An automated flow calorimeter has been developed for the accurate measurement of isobaric heat capacities for pure compounds and mixtures over the range (250 to 400) K and (0 to 20) MPa. In this paper, isobaric heat capacities for heptane, ethanol and the binary mixtures of ethanol with heptane and toluene are reported.

  1. Pork detection in binary meat mixtures and some commercial food products using conventional and real-time PCR techniques.

    Science.gov (United States)

    Al-Kahtani, Hassan A; Ismail, Elsayed A; Asif Ahmed, Mohammed

    2017-03-15

    Pork DNA was detected in meat mixtures using both conventional PCR and real-time PCR (RT-PCR). Thirty meat mixtures containing beef, chicken, camel, rabbit, goat and sheep with varying percentage of pork (0%, 1%, 5%, 10%, and 20%) and 75 commercial food products, were analyzed using conventional and RT-PCR to determine the presence of pork DNA. Pork DNA standard curves and cycle threshold (Ct) values were used for quantification. The detection limits for pork DNA in the mixtures were 0.22, 0.047, 0.048, 0.0000037, 0.015ng/μl respectively. Unlike conventional PCR, RT-PCR detected pork DNA in nine processed food samples [chicken sausages (2), chicken luncheon (2), turkey meat loaf, milk chocolate with soft nougat, jelly, cake, and candies] at pork DNA concentrations of 0.0001ng/μl or less. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Experimental investigation of stability and extinction coefficient of Al2O3–CuO binary nanoparticles dispersed in ethylene glycol–water mixture for low-temperature direct absorption solar collectors

    International Nuclear Information System (INIS)

    Menbari, Amir; Alemrajabi, Ali Akbar; Ghayeb, Yousef

    2016-01-01

    Highlights: • Viscosity and optical properties of binary nanofluids are investigated. • Effective parameters on stability of binary nanofluids are studied. • At optimal stability condition viscosity and absorbency of nanofluids are optimum. • The extinction coefficient of binary nanofluids is sum of its components ones. - Abstract: Binary nanofluids form a new class of nanofluids made through the simultaneous dispersion of two dissimilar nanoparticles in a base fluid. Two different nanoparticles may behave differently from their constituent components. Given the wide applications of binary nanofluids in a variety of fields, it is important to gain an understanding of the best stability conditions for binary nanofluids. In this work, the effects of such nanofluid properties as pH, surfactant (SHMP) concentration, and ultrasonic time are experimentally investigated on the stability of binary nanofluids. For this purpose, binary nanofluids are prepared using the two-step method. Two dissimilar nanoparticles, i.e. CuO and γ-Al 2 O 3 nanoparticles are dispersed in ethylene glycol and in the ethylene glycol–water mixture to form the desired nanofluids. Results show that at optimal stability conditions, viscosity and absorbency of the nanofluids are minimum and maximum, respectively. Also, the stability optimal parameters of binary nanofluids are found to be different from their corresponding values for each individual nanofluid. The extinction coefficient of the binary nanofluid is found to be approximately equal to the sum of those of the constituent components. Finally, the extinction coefficient of the nanoparticles dispersed in the mixture of ethylene glycol–water is determined to be greater than that of ethylene glycol.

  3. 37Cl(n,γ)38Cl reaction in binary mixtures of carbon tetrachloride with ethanol, heptanol and octanol

    International Nuclear Information System (INIS)

    Pertessis-Keis, M.

    2004-01-01

    37 Cl(n,γ) 38 Cl reaction in mixtures of CCl 4 with ethanol, heptanol and octanol exhibit a dependence on the tendency of the -COH group to cleave into CO and H. This tendency, shown here, correlates with the order of acidity of alkanols. (author)

  4. Property value estimation for inhaled therapeutic binary gas mixtures: He, Xe, N2O, and N2 with O2

    Directory of Open Access Journals (Sweden)

    Katz Ira

    2011-12-01

    Full Text Available Abstract Background The property values of therapeutic gas mixtures are important in designing devices, defining delivery parameters, and in understanding the therapeutic effects. In the medical related literature the vast majority of articles related to gas mixtures report property values only for the pure substances or estimates based on concentration weighted averages. However, if the molecular size or structures of the component gases are very different a more accurate estimate should be considered. Findings In this paper estimates based on kinetic theory are provided of density, viscosity, mean free path, thermal conductivity, specific heat at constant pressure, and diffusivity over a range of concentrations of He-O2, Xe-O2, N2O-O2 and N2-O2 mixtures at room (or normal and body temperature, 20 and 37°C, respectively and at atmospheric pressure. Conclusions Property value estimations have been provided for therapeutic gas mixtures and compared to experimental values obtained from the literature where possible.

  5. Electrostatic collection efficiency in binary fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Romero, A.; Guardiola, J.; Rincon, J. (Univ. of Alcala de Henares, Madrid (Spain))

    1992-01-01

    Fluidized beds of binary mixtures have been used to clean air streams containing dust particles in the size range 4.4 to 14 {mu}m. All beds were composed of glass beads and plastic granules mixed at different proportions. The effect on the electrostatic collection efficiency of a number of variables, including type of collecting mixture, bed height, and gas velocity, was examined. To calculate the single collection efficiency from experimental results, an early model proposed by Clift et al. was used. The electrostatic collection efficiency was determined by subtracting the other individual mechanism efficiencies from the single particle collection efficiency.

  6. A study of densities and volumetric properties of binary mixtures containing nitrobenzene at T=(293.15 to 353.15) K

    International Nuclear Information System (INIS)

    Wang Haijun; Wu Yonghua; Dong Weibo

    2005-01-01

    The densities of binary mixtures formed by nitrobenzene with benzene, or toluene, or ethylbenzene, or styrene, or o-xylene, or m-xylene, or p-xylene+nitrobenzene were measured in the temperature range of (293.15 to 353.15) K and ambient pressure using a vibrating-tube densimeter. The excess molar volumes V m E , partial molar volumes and excess partial molar volumes of two components calculated from the density data provide the temperature dependence. The V m E results were correlated using the fourth-order Redlich-Kister equation, with the maximum likelihood principle being applied for the determination of the adjustable parameters. It was found that the V m E in these systems studied increase with rising temperature

  7. Analysis of the binary mixtures using the reaction between iron(II) and cerium(IV) sulphate in phosphoric acid medium

    International Nuclear Information System (INIS)

    Krishna Murty, N.; Satyanarayana, V.; Rukmini, N.

    1978-01-01

    The reaction between iron(II) and cerium(IV) sulphate in phosphoric acid medium (6-12M) is studied potentiometrically and visually using methylene blue, thionine, azure A, azure B, azure C, toluidine blue, new methylene blue, variamine blue, ferroin, p-ethoxychrysoidine, N-phenylanthranilic acid and barium diphenylamine sulphonate as indicators. This reaction is made use for the analysis of binary mixtures of Fe(II)-Sn(II), Fe(II)-Ti(III), Fe(II)-U(IV), Fe(II)-Mo(V), Fe(II)-Fe(III) with Ce(IV) sulphate and Ce(IV)-U(VI), Ce(IV)-Mo(VI), Ce(IV)-V(V) and Ce(IV)-Cu(II) with iron (II). (author)

  8. A potentiometric study of molecular heteroconjugation equilibria in (n-butylamine+acetic acid) systems in binary (acetonitrile +1,4-dioxane) solvent mixtures

    International Nuclear Information System (INIS)

    Czaja, Malgorzata; Makowski, Mariusz; Chmurzynski, Lech

    2006-01-01

    By using the potentiometric method the following quantities have been determined: acidity constants of molecular acid, K a (HA), of cationic acid, K a (BH + ), anionic and cationic homoconjugation constants, K AHA - and K BHB + , respectively, as well as molecular heteroconjugation constants, K AHB , in (n-butylamine+acetic acid) systems without proton transfer in binary (acetonitrile+1,4-dioxane), AN+D, solvent mixtures. The results of these measurements have shown that the magnitudes of the molecular heteroconjugation constants do not depend on the 1,4-dioxane content in the mixed solvent, i.e., on solvent polarity. It has also been found that in the (acid+base) systems without proton transfer, the manner of carrying out the titration (direct B+HA vs. reverse HA+B) does not affect the magnitudes of the molecular heteroconjugation constants

  9. Organophosphinic, phosphonic acids and their binary mixtures as extractants for molybdenum(VI) and uranium(VI) from aqueous HCl media

    International Nuclear Information System (INIS)

    Behera, P.; Mishra, S.; Mohanty, I.; Chakravortty, V.

    1994-01-01

    Extraction studies of uranium(VI) and molybdenum(VI) with organophosphoric, phosphinic acid and its thiosubstituted derivatives have been carried out from 0.1-1.0M HCl solutions. The extracted species are proposed to be UO 2 R 2 and MoO 2 CIR on the basis of slope analysis for uranium(VI) and molybdenum(VI), respectively. The extraction efficiencies of PC-88A, Cyanex 272, Cyanex 301 and Cyanex 302 in the extraction of molybdenum(VI) and uranium(VI) are compared. Synergistic effects have been studied with binary mixtures of extractants. Separation of molybdenum(VI) from uranium(VI) is feasible by Cyanex 301 from 1M HCl, the separation factor logβ being 2.3. (author) 20 refs.; 5 figs.; 14 tabs

  10. A potentiometric study of molecular heteroconjugation equilibria in (n-butylamine+acetic acid) systems in binary (acetonitrile +1,4-dioxane) solvent mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Czaja, Malgorzata [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Makowski, Mariusz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Chmurzynski, Lech [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)]. E-mail: lech@chem.univ.gda.pl

    2006-05-15

    By using the potentiometric method the following quantities have been determined: acidity constants of molecular acid, K{sub a}(HA), of cationic acid, K{sub a}(BH{sup +}), anionic and cationic homoconjugation constants, K{sub AHA{sup -}} and K{sub BHB{sup +}}, respectively, as well as molecular heteroconjugation constants, K{sub AHB}, in (n-butylamine+acetic acid) systems without proton transfer in binary (acetonitrile+1,4-dioxane), AN+D, solvent mixtures. The results of these measurements have shown that the magnitudes of the molecular heteroconjugation constants do not depend on the 1,4-dioxane content in the mixed solvent, i.e., on solvent polarity. It has also been found that in the (acid+base) systems without proton transfer, the manner of carrying out the titration (direct B+HA vs. reverse HA+B) does not affect the magnitudes of the molecular heteroconjugation constants.

  11. Phase behaviour of symmetric binary mixtures with partially miscible components in slit-like pores. Application of the fundamental measure density functional approach

    CERN Document Server

    Martínez, A; Patrykiejew, A; Sokolowski, S

    2003-01-01

    We investigate adsorption in slit-like pores of model symmetric binary mixtures exhibiting demixing in bulk phase, by using a density functional approach. Our focus is on the evaluation of the first-order phase transitions in adsorbed fluids and the lines separating mixed and demixed phases. The scenario for phase transitions is sensitive to the pore width and to the energy of adsorption. Both these parameters can change the phase diagrams of the confined fluid. In particular, for relatively wide pores and for strong wall-fluid interactions, the demixing line can precede the first-order transition. Moreover, a competition between layering transitions and demixing within particular layers also leads to further enrichment of the phase diagram.

  12. A methodology to relate octane numbers of binary and ternary n-heptane, iso-octane and toluene mixtures with simulated ignition delay times

    KAUST Repository

    Badra, Jihad A.

    2015-08-11

    Predicting octane numbers (ON) of gasoline surrogate mixtures is of significant importance to the optimization and development of internal combustion (IC) engines. Most ON predictive tools utilize blending rules wherein measured octane numbers are fitted using linear or non-linear mixture fractions on a volumetric or molar basis. In this work, the octane numbers of various binary and ternary n-heptane/iso-octane/toluene blends, referred to as toluene primary reference fuel (TPRF) mixtures, are correlated with a fundamental chemical kinetic parameter, specifically, homogeneous gas-phase fuel/air ignition delay time. Ignition delay times for stoichiometric fuel/air mixtures are calculated at various constant volume conditions (835 K and 20 atm, 825 K and 25 atm, 850 K and 50 atm (research octane number RON-like) and 980 K and 45 atm (motor octane number MON-like)), and for variable volume profiles calculated from cooperative fuel research (CFR) engine pressure and temperature simulations. Compression ratio (or ON) dependent variable volume profile ignition delay times are investigated as well. The constant volume RON-like ignition delay times correlation with RON was the best amongst the other studied conditions. The variable volume ignition delay times condition correlates better with MON than the ignition delay times at the other tested conditions. The best correlation is achieved when using compression ratio dependent variable volume profiles to calculate the ignition delay times. Most of the predicted research octane numbers (RON) have uncertainties that are lower than the repeatability and reproducibility limits of the measurements. Motor octane number (MON) correlation generally has larger uncertainties than that of RON.

  13. Volumetric and viscometric study of aqueous binary mixtures of some glycol ethers at T = (275.15 and 283.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Dhondge, Sudhakar S., E-mail: s_dhondge@hotmail.com [Department of Chemistry, S.K. Porwal College, Kamptee, Dist. Nagpur 441 002 (India); Pandhurnekar, Chandrashekhar P. [Shri Ramdeobaba Kamla Nehru Engineering College, Nagpur 440 013 (India); Sheikh, Shaziya; Deshmukh, Dinesh W. [Department of Chemistry, R.T.M. Nagpur University, Nagpur 440 033 (India)

    2011-12-15

    Graphical abstract: Highlights: > Study of aqueous solutions of glycol ethers at low temperatures is presented. > Glycol ethers are industrially important liquids. > Reduction in the volume was observed upon addition of all glycol ethers to water. > Glycol ethers act as structure makers in aqueous medium. - Abstract: The experimental data for the density ({rho}) and viscosity ({eta}) are reported for aqueous binary mixtures of different glycol ethers, namely ethylene glycol monomethyl ether (EGMME), ethylene glycol monoethyl ether (EGMEE), diethylene glycol monomethyl ether (DEGMME), and diethylene glycol monoethyl ether (DEGMEE), at different temperatures (T = 275.15 K and 283.15 K) within the concentration range 0 mol . kg{sup -1} to 0.1 mol . kg{sup -1}. The values of density ({rho}) and viscosity ({eta}) of the solutions were used to compute different derived parameters, such as apparent molar volume ({phi}{sub V}) of the solute, excess molar volume (V{sup E}) of the solution, viscosity B and D coefficients of solution and temperature coefficient of viscosity B-coefficient (dB/dT) of solution. The limiting apparent molar volume of the solutes ({phi}{sub V}{sup 0}) have been obtained for aqueous binary mixtures of these glycol ethers by smooth extrapolation of {phi}{sub V}-m curves to zero concentration. By using the values of {phi}{sub V}{sup 0}, the limiting excess partial molar volumes (V-bar{sub 2}{sup 0E}) have also been calculated. The results are interpreted in term of various interactions such as solute-solvent interactions and hydrogen bonding.

  14. Proteomic analysis in Daphnia magna exposed to As(III), As(V) and Cd heavy metals and their binary mixtures for screening potential biomarkers.

    Science.gov (United States)

    Le, Thai-Hoang; Lim, Eun-Suk; Hong, Nam-Hui; Lee, Sung-Kyu; Shim, Yon Sik; Hwang, Jin Rae; Kim, Yang-Hoon; Min, Jiho

    2013-11-01

    In this study, the effects of three widespread heavy metals, As(III), As(V) and Cd, and their binary mixtures on the proteomic profile in D. magna were examined to screen novel protein biomarkers using the two-dimensional gel electrophoresis method (2DE). Ten 20d daphnia were exposed to the LC20 concentrations for each of a total of 8 treatments, including the control, As(III), As(V), Cd, [As(III)+As(V)], [As(III)+Cd], [As(V)+Cd], and [As(III), As(V), Cd], for 24h before protein isolation. Three replicates were performed for each treatment. These protein samples were employed for 2DE experiments with a pH gradient gel strip from pH 3 to pH 10. The protein spots were detected by a silver staining process and their intensities were analyzed by Progenesis software to discover the differentially expressed proteins (DEPs) in response to each heavy metal. A total of 117 differentially expressed proteins (DEPs) were found in daphnia responding to the 8 treatments and mapped onto a 2D proteome map, which provides some information of the molecular weight (MW) and pI value for each protein. All of these DEPs are considered as potential candidates for protein biomarkers in D. magna for detecting heavy metals in the aquatic ecosystem. Comparing the proteomic results among these treatments suggested that exposing D. magna to binary mixtures of heavy metals may result in some complex interactive molecular responses within them, rather than just the simple sum of the proteomic profiles of the individual chemicals, (As(III), As(V), and Cd). Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Experimental study of thermodynamic and transport properties of binary mixtures of poly(ethylene glycol diacrylate and alcohols at different temperatures

    Directory of Open Access Journals (Sweden)

    Vuksanović Jelena M.

    2015-01-01

    Full Text Available Experimental density r, refractive index nD and viscosity h data of three binary systems of poly(ethylene glycol diacrylate (PEGDA + ethanol, + 1-propanol, and + 1-butanol were measured at eight temperatures from (288.15 to 323.15 K, with temperature step of 5 K, and at atmospheric pressure. The experimental data were correlated as a function of PEGDA mole fraction and temperature. Densities and refractive indices of the investigated mixtures could be fitted well with exponential function vs. composition, including temperature dependence of parameters, while in the case of viscosities polynomial function fits well over a mixture’s composition. In the case of temperature correlation, all three properties (ρ, lnη and nD exhibit linear trend. The viscosity modeling was performed using four models: UNIFAC-VISCO, ASOG-VISCO, Mc-Allister and Teja-Rice. For application of UNIFAC-VISCO model interaction parameters of following groups were determined: CH2=CH/CH3, CH2=CH/CH2, CH2=CH/OH, CH2=CH/CH2O and CH2=CH/COO. Also, in the same way binary interaction parameters used in ASOG-VISCO of the following groups were determined: CH2=CH/CH2, CH2=CH/OH, CH2=CH/CH2O and CH2=CH/COO. [Projekat Ministarstva nauke Republike Srbije, br. 172063

  16. Chemical-physical characterization of a binary mixture made of a photosensitive azobenzene derivative and a smectogen

    Czech Academy of Sciences Publication Activity Database

    Borello, E.; Cifelli, M.; Duce, C.; Galli, G.; Tine, M.R.; Hamplová, Věra; Ambrozic, G.; Domenici, V.

    2015-01-01

    Roč. 614, č. 1 (2015), s. 54-61 ISSN 1542-1406 R&D Projects: GA ČR GA13-14133S; GA MŠk(CZ) 7AMB14PL035 Grant - others:AVČR(CZ) M100101204; AVČR(CZ) M100101211 Institutional support: RVO:68378271 Keywords : liquid crystalline mixture * nematic * smectic A * photosensitive molecules * DSC * 2HNMR Subject RIV: CC - Organic Chemistry Impact factor: 0.532, year: 2015

  17. Hydromagnetic and Soret driving free convection in an inclined porous cavity saturated by a conducting binary mixture

    Directory of Open Access Journals (Sweden)

    Amahmid A.

    2012-07-01

    Full Text Available We consider the Soret convection in an inclined rectangular Darcy porous medium filled with an electrically conductive binary fluid. The long sidewalls of the porous cavity are subject to constant gradients of heat and submitted to a uniform and constant transversal magnetic field while its short sides are adiabatic and impermeable. An approximate analytical solution to the present problem, valid in the central part of the shallow cavity, is obtained on the basis of the parallel flow approximation and validated numerically using a finite-difference method. Results are presented in terms of streamlines, isotherms, iso-concentration lines, Nusselt and Sherwood numbers and separation of species for Hartmann number varying in the range [0, 20]. A good agreement is observed between the analytical predictions and numerical simulations.

  18. Binary combinations of organophosphorus and synthetic pyrethroids are more potent acetylcholinesterase inhibitors than organophosphorus and carbamate mixtures: An in vitro assessment.

    Science.gov (United States)

    Arora, Sumitra; Balotra, Sahil; Pandey, Gunjan; Kumar, Anu

    2017-02-15

    Anticholinesterase insecticides such as organophosphorous (OP) and carbamates pesticides (CB); and synthetic pyrethroids (SP) pesticides commonly co-occur in the environment. This raises the possibility of antagonistic, additive, or synergistic neurotoxicity in exposed organisms. Acetylcholinesterase (AChE) inhibition has been demonstrated to be useful as a biomarker for exposure to OP and CBs in many environments. This study investigated the response of housefly (Musca domestica) head AChE (HF-AChE) exposed to five OPs; chlorpyrifos (CPF), malathion (MLT), triazophos (TRZ), monocrotophos (MCP) and profenofos (PRF) and two CBs; carbaryl (CRB) and carbofuran (CBF) as individual compounds and as binary mixtures of OPs and CBs under in vitro conditions. In addition, the selected OPs and CBs were evaluated for their toxicity in binary combinations with two SPs; deltamethrin (DLT) and cypermethrin (CYP) at fixed concentrations of 0.1 and 10μg/L. The toxicological interaction of five OPs with two CBs pesticides was evaluated under oxidised and un-oxidised conditions using a toxic unit (TU) approach and a concentration addition (CA) model. Pyrethroid combinations were assessed only under oxidised conditions. Since OPs and CBs act by a similar mechanism of inhibition of AChE, a dose additive effect was expected, but not conclusively found. TRZ with either CBF or CRB exhibited synergism under oxidised and un-oxidised conditions but the degree of synergism was stronger under un-oxidised conditions. Additivity was exhibited by CBF+MCP, CRB+MCP, CRB+MLT and CBF+MCP under un-oxidised conditions and CRB+MCP and CRB+CPF under oxidised conditions. Pyrethorids in combination with OPs (TRZ, MLT and CPF) were highly synergistic. In the present study, we used pure housefly head AChE without any interference of monooxygenase and/or esterase enzyme activities. Therefore these other enzymes were not producing the observed deviations from concentration-addition in the binary combinations

  19. Non-monotonic dynamics of water in its binary mixture with 1,2-dimethoxy ethane: A combined THz spectroscopic and MD simulation study.

    Science.gov (United States)

    Das Mahanta, Debasish; Patra, Animesh; Samanta, Nirnay; Luong, Trung Quan; Mukherjee, Biswaroop; Mitra, Rajib Kumar

    2016-10-28

    A combined experimental (mid- and far-infrared FTIR spectroscopy and THz time domain spectroscopy (TTDS) (0.3-1.6 THz)) and molecular dynamics (MD) simulation technique are used to understand the evolution of the structure and dynamics of water in its binary mixture with 1,2-dimethoxy ethane (DME) over the entire concentration range. The cooperative hydrogen bond dynamics of water obtained from Debye relaxation of TTDS data reveals a non-monotonous behaviour in which the collective dynamics is much faster in the low X w region (where X w is the mole fraction of water in the mixture), whereas in X w ∼ 0.8 region, the dynamics gets slower than that of pure water. The concentration dependence of the reorientation times of water, calculated from the MD simulations, also captures this non-monotonous character. The MD simulation trajectories reveal presence of large amplitude angular jumps, which dominate the orientational relaxation. We rationalize the non-monotonous, concentration dependent orientational dynamics by identifying two different physical mechanisms which operate at high and low water concentration regimes.

  20. Studies on thermodynamic properties of binary mixtures of hexan-1-ol with halogenated compounds at T = (308.15 and 313.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, Subhash C. [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119, Haryana (India)], E-mail: bhatiasc2@rediffmail.com; Bhatia, Rachna [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119, Haryana (India)], E-mail: bhatiarachna_3@rediffmail.com; Dubey, Gyan P. [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119, Haryana (India)], E-mail: gyan.dubey@rediffmail.com

    2009-10-15

    Densities, {rho}, and ultrasonic velocities, u of binary mixtures of hexan-1-ol with 1,2-dichloroethane, 1,2-dibromoethane, and 1,1,2,2-tetrachloroethene have been measured over the entire range of composition and temperature at (308.15 and 313.15) K. From these experimental results, the excess molar volumes, V{sup E}, excess molar isentropic compressibility, K{sub S,m}{sup E}, molar free volumes, V{sub f}, intermolecular free lengths, L{sub f}, mean molecular radii, r, Beyer's parameters of non-linearity, B/A, and limiting excess partial molar volumes, V-bar{sub i}{sup E,0}, have been estimated. The excess functions have been fitted to the Redlich-Kister polynomial equations. The experimental ultrasonic velocities have been analyzed in terms of Nomoto's relation, Van Dael's ideal mixture relation, Jacobson's free length theory, Schaaffs collision factor theory and thermoacoustical parameters.

  1. Volumetric, acoustic, and viscometric studies of molecular interactions in binary mixtures of dipropylene glycol dimethyl ether with 1-alkanols at 298.15 K

    International Nuclear Information System (INIS)

    Pal, Amalendu; Gaba, Rekha

    2008-01-01

    In this work densities, ρ, ultrasonic speeds, u, and viscosities, η, have been measured over the whole composition range for the binary mixtures of dipropylene glycol dimethyl ether (DPGDME) with ethanol, 1-propanol, 1-pentanol, and 1-heptanol at 298.15 K along with the properties of the pure components. By using the experimental values of ρ, u, and η, excess molar volume, V m E , deviations in viscosity, Δη, excess free energy of activation for viscous flow, ΔG* E , excess molar isentropic compressibility, K S,m E , deviation of the speeds of sound, u D , from their ideal values u id in an ideal mixtures, apparent molar volume, and apparent molar compressibility, V-bar φ,i 0 and K-bar φ,i 0 of the components at infinite dilution have been calculated. Finally, the experimental viscosity data have been correlated by the methods of Grunberg-Nissan, Hind, Tamura-Kurata, Chaudhry, Auslaender, Heric, and with McAllister correlations

  2. (Vapour + liquid) equilibria and excess molar enthalpies for binary mixtures containing N,N-dialkylamides and 1-chloroalkanes

    International Nuclear Information System (INIS)

    Garcia-Gimenez, P.; Munoz Embid, J.; Velasco, I.; Otin, S.

    2007-01-01

    Isothermal (vapour + liquid) equilibria (VLE) and excess molar enthalpies H m E have been measured for liquid (N,N-dimethylformamide or N,N-dimethylacetamide + 1-chlorobutane, or + 1-chlorohexane, or + 1-chlorooctane mixtures). The VLE data have been reduced using the Redlich-Kister equation taking into consideration the vapour phase imperfection in terms of 2nd molar virial coefficients. The experimental results show that both H m E andG m E are positive and increase with increasing chain length of the 1-chloroalkane

  3. Volumetric properties of some pharmaceutical binary mixtures at low temperatures and correlation with the jouyban-acree model

    OpenAIRE

    Rodriguez, Gerson

    2011-01-01

    Excess molar volumes and partial molar volumes were investigated from density values for a) ethanol (1) + water (2), b) 1,2-propanediol (1) + water (2), and c) ethanol (1) + 1,2-propanediol (2) mixtures, at temperatures from (278.15 to 288.15) K. Excess molar volumes were fitted by Redlich-Kister equation. The systems exhibit negative excess volumes probably due to increased interactions like hydrogen bonding and/ or large differences in molar volumes of components. The Jouyban-Acree model wa...

  4. A new equation of state for CCS pipeline transport: Calibration of mixing rules for binary mixtures of CO2 with N2, O2 and H2

    International Nuclear Information System (INIS)

    Demetriades, Thomas A.; Graham, Richard S.

    2016-01-01

    Highlights: • We develop a general framework for pressure-explicit equations of state for impure CO 2 . • For CCS modelling, we consider mixture data around the CO 2 critical point. • We generalise a pure CO 2 equation of state to mixtures with N 2 , O 2 and H 2 . • For N 2 and H 2 our model captures coexistence data more accurately than the GERG. - Abstract: One of the aspects currently holding back commercial scale deployment of carbon capture and storage (CCS) is an accurate understanding of the thermodynamic behaviour of carbon dioxide and relevant impurities during the pipeline transport stage. In this article we develop a general framework for deriving pressure-explicit EoS for impure CO 2 . This flexible framework facilitates ongoing development of custom EoS in response to new data and computational applications. We use our method to generalise a recent EoS for pure CO 2 (Demetriades et al., 2013) to binary mixtures with N 2 , O 2 and H 2 , obtaining model parameters by fitting to experiments made under conditions relevant to CCS-pipeline transport. Our model pertains to pressures up to 16 MPa and temperatures between 273 K and the critical temperature of pure CO 2 . In this region, we achieve close agreement with experimental data. When compared to the GERG EoS, our EoS has a comparable level of agreement with (CO 2 + N 2 ) VLE experiments and demonstrably superior agreement with the O 2 and H 2 VLE data. Finally, we discuss future options to improve the calibration of EoS and to deal with the sparsity of data for some impurities.

  5. Phase behavior of binary mixture systems of saturated-unsaturated mixed-acid triacylglycerols: effects of glycerol structures and chain-chain interactions.

    Science.gov (United States)

    Bayés-García, Laura; Calvet, Teresa; Cuevas-Diarte, Miquel Àngel; Ueno, Satoru; Sato, Kiyotaka

    2015-03-26

    We systematically examined the phase behavior of binary mixtures of mixed-acid triacylglycerols (TAGs) containing palmitic and oleic acid moieties 1,3-dioleoyl-2-palmitoyl-glycerol (OPO), 1,2-dipalmitoyl-3-oleoyl-rac-glycerol (PPO), and 1,2-dioleoyl-3-palmitoyl-rac-glycerol (OOP), which are widely present in natural fats and are employed in the food, pharmaceutical, and cosmetic industries. Differential scanning calorimetry and X-ray diffraction methods were applied to observe the mixing behavior of PPO/OPO, OOP/OPO, and PPO/OOP under metastable and stable conditions. The results led to three conclusions: (1) Eutectic behavior was observed in PPO/OPO. (2) Molecular compound (MC) crystals were formed in the mixtures of OOP/OPO and PPO/OOP. (3) However, the MC crystals occurred only under metastable conditions and tended to separate into component TAGs to form eutectic mixture systems after 17 months of incubation. These results were contrary to those of previous studies on 1,3-dipalmitoyl-2-oleoyl glycerol (POP)/OPO and POP/PPO in which the MC crystals were thermodynamically stable. We determined that specific molecular interactions may cause this different phase behavior (stability of POP/OPO and POP/PPO MC crystals and metastability of OOP/OPO and PPO/OOP MC crystals). All results confirm the significant effects of molecular structures of glycerol groups, interactions of fatty acid chains, and polymorphism of the component TAGs on the mixing behavior of mixed-acid TAGs.

  6. Molecular Factors Governing the Liquid and Glassy States Recrystallization of Celecoxib in Binary Mixtures with Excipients of Different Molecular Weights.

    Science.gov (United States)

    Grzybowska, K; Chmiel, K; Knapik-Kowalczuk, J; Grzybowski, A; Jurkiewicz, K; Paluch, M

    2017-04-03

    Transformation of poorly water-soluble crystalline pharmaceuticals to the amorphous form is one of the most promising strategies to improve their oral bioavailability. Unfortunately, the amorphous drugs are usually thermodynamically unstable and may quickly return to their crystalline form. A very promising way to enhance the physical stability of amorphous drugs is to prepare amorphous compositions of APIs with certain excipients which can be characterized by significantly different molecular weights, such as polymers, acetate saccharides, and other APIs. By using different experimental techniques (broadband dielectric spectroscopy, differential scanning calorimetry, X-ray diffraction) we compare the effect of adding the large molecular weight polymer-polyvinylpyrrolidone (PVP K30)-and the small molecular weight excipient-octaacetylmaltose (acMAL)-on molecular dynamics as well as the tendency to recrystallization of the amorphous celecoxib (CEL) in the amorphous solid dispersions: CEL-PVP and CEL-acMAL. The physical stability investigations of the binary systems were performed in both the supercooled liquid and glassy states. We found that acMAL is a better inhibitor of recrystallization of amorphous CEL than PVP K30 deep in the glassy state (T T g ). We discuss molecular factors governing the recrystallization of amorphous CEL in examined solid dispersions.

  7. Laser photolysis study of anthraquinone in binary mixtures ofionic liquid [bmim][PF6] and organic solvent

    Directory of Open Access Journals (Sweden)

    Side Yao

    2006-12-01

    Full Text Available Photochemical properties of the ionic liquid (RTIL 1-butyl-3-methylimidazoliumhexafluorophosphate [bmim][PF6] and its binary mixed solutions with organic solvent(DMF and MeCN were investigated by laser photolysis at an excitation wavelength of 355nm, using anthraquinone (AQ as a probe molecule. It was indicated that the triplet excitedstate of AQ (3AQ* can abstract hydrogen from [bmim][PF6]. Moreover, along with thechange of the ratio of RTIL and organic solvent, the reaction rate constant changes regularly.Critical points were observed at volume fraction VRTIL = 0.2 for RTIL/MeCN and VRTIL =0.05 for RTIL/DMF. For both systems, before the critical point, the rate constant increasesrapidly with increasing VRTIL; however, it decreases obviously with VRTIL after the criticalpoint. We conclude that the concentration dependence is dominant at lower VRTIL, while theviscosity and phase transformation are dominant at higher VRTIL for the effect of ionic liquidon the decay of rate constant.

  8. Thermodynamic Investigation of the Effect of Interface Curvature on the Solid-Liquid Equilibrium and Eutectic Point of Binary Mixtures.

    Science.gov (United States)

    Liu, Fanghui; Zargarzadeh, Leila; Chung, Hyun-Joong; Elliott, Janet A W

    2017-10-12

    Thermodynamic phase behavior is affected by curved interfaces in micro- and nanoscale systems. For example, capillary freezing point depression is associated with the pressure difference between the solid and liquid phases caused by interface curvature. In this study, the thermal, mechanical, and chemical equilibrium conditions are derived for binary solid-liquid equilibrium with a curved solid-liquid interface due to confinement in a capillary. This derivation shows the equivalence of the most general forms of the Gibbs-Thomson and Ostwald-Freundlich equations. As an example, the effect of curvature on solid-liquid equilibrium is explained quantitatively for the water/glycerol system. Considering the effect of a curved solid-liquid interface, a complete solid-liquid phase diagram is developed over a range of concentrations for the water/glycerol system (including the freezing of pure water or precipitation of pure glycerol depending on the concentration of the solution). This phase diagram is compared with the traditional phase diagram in which the assumption of a flat solid-liquid interface is made. We show the extent to which nanoscale interface curvature can affect the composition-dependent freezing and precipitating processes, as well as the change in the eutectic point temperature and concentration with interface curvature. Understanding the effect of curvature on solid-liquid equilibrium in nanoscale capillaries has applications in the food industry, soil science, cryobiology, nanoporous materials, and various nanoscience fields.

  9. Binary mixture of Satureja hortensis and Origanum vulgare subsp. hirtum essential oils: in vivo therapeutic efficiency against Helicobacter pylori infection.

    Science.gov (United States)

    Harmati, Maria; Gyukity-Sebestyen, Edina; Dobra, Gabriella; Terhes, Gabriella; Urban, Edit; Decsi, Gabor; Mimica-Dukić, Neda; Lesjak, Marija; Simin, Nataša; Pap, Bernadett; Nemeth, Istvan B; Buzas, Krisztina

    2017-04-01

    Helicobacter pylori can cause many gastrointestinal and also extra-gastrointestinal disorders and is a major risk factor for gastric carcinoma and MALT lymphoma. Currently, numerous antibiotic-based therapies are available; however, these therapies have numerous drawbacks, mainly due to increasing prevalence of antibiotic resistant strains. Thus, there is an urgent need to develop novel therapeutic agents against H. pylori infections. In this study, the anti-H. pylori activity of 2:1 mixture of Satureja hortensis and Origanum vulgare subsp. hirtum essential oils (2MIX) was investigated in vivo. After screening in vitro cytotoxicity of 2MIX on mammalian cell lines, the therapeutic efficiency was studied in a mouse model, where changes in H. pylori colonization were detected by PCR and histology of gastric samples. The immune reaction of mice was tested based on cytokine and chemokine production, and the in vivo toxicity of 2MIX was also investigated by measuring ALT and AST enzyme activities and Cyp3a11 and HO-1 mRNA levels in livers of mice. 2MIX had not shown in vitro cytotoxicity against cell lines, only the highest concentration caused significant decrease in their survival rates. In the in vivo experiments, 2MIX successfully eradicated the pathogen in 70% of the mice. We could not detect toxicity or altered cytokine and chemokine balance after in vivo treatments in mice. These results show that 2MIX is effective in reducing H. pylori colonization suggesting that this essential oil mixture has great potential as a new, effective, and safe therapeutic agent against H. pylori. © 2016 John Wiley & Sons Ltd.

  10. My Career: Composer

    Science.gov (United States)

    Morganelli, Patrick

    2013-01-01

    In this article, the author talks about his career as a composer and offers some advice for aspiring composers. The author works as a composer in the movie industry, creating music that supports a film's story. Other composers work on television shows, and some do both television and film. The composer uses music to tell the audience what kind of…

  11. Thermal, Mutual and Self-Diffusivities in Binary Liquid Mixtures Consisting of n-Alkanes with Dissolved Gases at Infinite Dilution.

    Science.gov (United States)

    Giraudet, Cédric; Klein, Tobias; Zhao, Guanjia; Rausch, Michael Heinrich; Koller, Thomas M; Fröba, Andreas Paul

    2018-02-27

    In the present study, dynamic light scattering (DLS) experiments and molecular dynamics (MD) simulations were used for the investigation of the molecular diffusion in binary mixtures of liquids with dissolved gases at macroscopic thermodynamic equilibrium. Model systems based on the n-alkanes n-hexane or n-decane with dissolved hydrogen, helium, nitrogen, or carbon monoxide were studied at temperatures between 303 and 423 K and at gas mole fractions below 0.06. With DLS, the relaxation behavior of microscopic equilibrium fluctuations in concentration and temperature is analyzed to determine simultaneously mutual and thermal diffusivity in an absolute way. The present measurements document that even for mole gas fractions of 0.007 and Lewis numbers close to 1, reliable mutual diffusivities with an average expanded uncertainty (k = 2) of 13% can be obtained. Using suitable molecular models for the mixture components, the self-diffusion coefficient of the gases was determined by MD simulations with an averaged expanded uncertainty (k = 2) of 7%. The DLS experiments showed that the thermal diffusivity of the studied systems is not affected by the dissolved gas and agrees with the reference data for the pure n-alkanes. In agreement with theory, mutual diffusivities and self-diffusivities were found to be equal mostly within combined uncertainties at conditions approaching infinite dilution of the gas. Our DLS and MD results, representing the first available data for the present systems, reveal distinctly larger mass diffusivities for mixtures containing hydrogen or helium compared to mixtures containing nitrogen or carbon monoxide. Based on the broad range of mass diffusivities of the studied gas-liquid systems covering about two orders of magnitude from about 10 -9 to 10 -7 m 2 ·s -1 , effects of the solvent and solute properties on the temperature-dependent mass diffusivities are discussed. This contributed to the development of a simple semi-empirical correlation

  12. Effect of Moisture on the Thermoresponsive Properties of Binary Mixtures of Monoglycerides for Triggerable Drug Delivery Systems.

    Science.gov (United States)

    Stonewall, Hannah D; Kessinger, Haley M; Mengesha, Abebe E

    2017-10-01

    The crystallization behavior and temperature-dependent phase transition of monoglycerides have been utilized to develop thermal-sensitive drug delivery systems. The presence of excess water has been reported to influence the phase transition. The present study investigates the effect of moisture on the thermal behavior of binary blends of monoglycerides. Various compositions (0-100 wt%) of glyceryl monooleate (GMO) and glyceryl monostearate (GMS) were prepared by fusion method, and exposed to varying relative humidity (RH) levels (0-100%). The moisture uptakes, sorption isotherm, and the thermal behavior of GMO-GMS samples were analyzed using differential scanning calorimeter (DSC), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The in vitro nifedipine (NF) release was studied at 37 and 42°C. Samples of GMO-GMS (25:75, 50:50, and 75:25 wt%) stored at 97%RH at 25°C for 3 weeks increased in weight by 14.0, 14.7, and 15.8%, respectively. Despite such high moisture uptake, the GMO-GMS matrices maintained crystalline structure. The melting point (T m ) and heat of fusion (ΔH f ) of the samples were reduced as the amount of moisture in the matrices increased. However, the heat of fusion calculated on dry basis remained constant at 139.4 ± 1.25, 102.7 ± 1.14, and 46.7 ± 1.16 J/g for GMO-GMS 25:75, 50:50, and 75:25 wt%, respectively. The comparison of the XRD measurements of the dry samples with those containing 30% water confirmed the preserved crystalline arrangement in the matrices. This study indicates that despite the high moisture uptakes, the GMO-GMS matrices retained their crystalline properties and provided temperature-dependent drug release indicating the potential application for thermoresponsive local drug delivery systems.

  13. Ultra small angle neutron scattering : a tool to study packing of relatively monodisperse small polymer spheres and their binary mixtures

    International Nuclear Information System (INIS)

    Reynolds, Philip A.; McGillivray, Duncan J.; White, John W.; Jackson, Andrew J.; University of Maryland, College Paerk, Maryland, USA

    2009-01-01

    Full text: We measured ultra small angle neutron scattering (USANS) from polymethylmethacrylate spheres tamped down in air. Two slightly polydisperse pure sphere sizes (1.5/-lm and 7.5/-lm diameter) and five mixtures of these were used. All were loose packed (packing fractions 0.3 to 0.6) with nongravitational forces (e.g., friction) important, preventing close packing. The USANS data is rich in information on powder packing. A modified Percus-Yevick fluid model was used to parametrise the data - adequately but not well. The modifications required introduction of small voids, less than the sphere size, and a parameter reflecting substantial deviation from the Percus-Yevick prediction of the sphere-sphere correlation function. The mixed samples fitted less well, and two further modifying factors were necessary. These were local inhomogeneities, where the concentration of same-size spheres, both large and small, deviated from the mean packing, and a factor accounting for the presence within these 'clusters' of self avoidance of the large spheres (that is large spheres coated with more small spheres than Percus-Yevick would predict). The overall deviations from the hardsphere Percus-Yevick model that we find here suggests fluid models of loose packed powders are unlikely to be successful, but lay the groundwork for future theoretical and computational work.

  14. Molecular interactions in the ionic liquid emim acetate and water binary mixtures probed via NMR spin relaxation and exchange spectroscopy.

    Science.gov (United States)

    Allen, Jesse J; Bowser, Sage R; Damodaran, Krishnan

    2014-05-07

    Interactions of ionic liquids (ILs) with water are of great interest for many potential IL applications. 1-Ethyl-3-methylimidazolium (emim) acetate, in particular, has shown interesting interactions with water including hydrogen bonding and even chemical exchange. Previous studies have shown the unusual behavior of emim acetate when in the presence of 0.43 mole fraction of water, and a combination of NMR techniques is used herein to investigate the emim acetate-water system and the unusual behavior at 0.43 mole fraction of water. NMR relaxometry techniques are used to describe the effects of water on the molecular motion and interactions of emim acetate with water. A discontinuity is seen in nuclear relaxation behavior at the concentration of 0.43 mole fraction of water, and this is attributed to the formation of a hydrogen bonded network. EXSY measurements are used to determine the exchange rates between the H2 emim proton and water, which show a complex dependence on the concentration of the mixture. The findings support and expand our previous results, which suggested the presence of an extended hydrogen bonding network in the emim acetate-water system at concentrations close to 0.50 mole fraction of H2O.

  15. Explicit expressions of self-diffusion coefficient, shear viscosity, and the Stokes-Einstein relation for binary mixtures of Lennard-Jones liquids

    International Nuclear Information System (INIS)

    Ohtori, Norikazu; Ishii, Yoshiki

    2015-01-01

    Explicit expressions of the self-diffusion coefficient, D i , and shear viscosity, η sv , are presented for Lennard-Jones (LJ) binary mixtures in the liquid states along the saturated vapor line. The variables necessary for the expressions were derived from dimensional analysis of the properties: atomic mass, number density, packing fraction, temperature, and the size and energy parameters used in the LJ potential. The unknown dependence of the properties on each variable was determined by molecular dynamics (MD) calculations for an equimolar mixture of Ar and Kr at the temperature of 140 K and density of 1676 kg m −3 . The scaling equations obtained by multiplying all the single-variable dependences can well express D i and η sv evaluated by the MD simulation for a whole range of compositions and temperatures without any significant coupling between the variables. The equation for D i can also explain the dual atomic-mass dependence, i.e., the average-mass and the individual-mass dependence; the latter accounts for the “isotope effect” on D i . The Stokes-Einstein (SE) relation obtained from these equations is fully consistent with the SE relation for pure LJ liquids and that for infinitely dilute solutions. The main differences from the original SE relation are the presence of dependence on the individual mass and on the individual energy parameter. In addition, the packing-fraction dependence turned out to bridge another gap between the present and original SE relations as well as unifying the SE relation between pure liquids and infinitely dilute solutions

  16. Explicit expressions of self-diffusion coefficient, shear viscosity, and the Stokes-Einstein relation for binary mixtures of Lennard-Jones liquids

    Energy Technology Data Exchange (ETDEWEB)

    Ohtori, Norikazu, E-mail: ohtori@chem.sc.niigata-u.ac.jp [Department of Chemistry, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181 (Japan); Ishii, Yoshiki [Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181 (Japan)

    2015-10-28

    Explicit expressions of the self-diffusion coefficient, D{sub i}, and shear viscosity, η{sub sv}, are presented for Lennard-Jones (LJ) binary mixtures in the liquid states along the saturated vapor line. The variables necessary for the expressions were derived from dimensional analysis of the properties: atomic mass, number density, packing fraction, temperature, and the size and energy parameters used in the LJ potential. The unknown dependence of the properties on each variable was determined by molecular dynamics (MD) calculations for an equimolar mixture of Ar and Kr at the temperature of 140 K and density of 1676 kg m{sup −3}. The scaling equations obtained by multiplying all the single-variable dependences can well express D{sub i} and η{sub sv} evaluated by the MD simulation for a whole range of compositions and temperatures without any significant coupling between the variables. The equation for D{sub i} can also explain the dual atomic-mass dependence, i.e., the average-mass and the individual-mass dependence; the latter accounts for the “isotope effect” on D{sub i}. The Stokes-Einstein (SE) relation obtained from these equations is fully consistent with the SE relation for pure LJ liquids and that for infinitely dilute solutions. The main differences from the original SE relation are the presence of dependence on the individual mass and on the individual energy parameter. In addition, the packing-fraction dependence turned out to bridge another gap between the present and original SE relations as well as unifying the SE relation between pure liquids and infinitely dilute solutions.

  17. Density and Comparative Refractive Index Study on Mixing Properties of Binary Liquid Mixtures of Eucalyptol with Hydrocarbons at 303.15, 308.15 and 313.15 K

    OpenAIRE

    Sharma, Sangita; Patel, Pragnesh B.; Patel, Rignesh S.; Vora, J. J.

    2007-01-01

    Density and refractive index have been experimentally determined for binary liquid mixtures of eucalyptol with hydrocarbons (o-xylene,m-xylene and toluene) at 303.15 K, 308.15 K and 313.15 K. A comparative study of Lorentz-Lorenz (L-L), Weiner (W), Heller (H), Gladstone-Dale (G-D), Arago-Biot (A-B), Eykman (Eyk), Newton (Nw), Eyring-John (E-J) and Oster (Os) relations for determining the refractive index of a liquid has been carried out to test their validity for the three binaries over the e...

  18. Binary colloidal crystals

    NARCIS (Netherlands)

    Christova-Zdravkova, C.G.

    2005-01-01

    Binary crystals are crystals composed of two types of particles having different properties like size, mass density, charge etc. In this thesis several new approaches to make binary crystals of colloidal particles that differ in size, material and charge are reported We found a variety of crystal

  19. Resolution of ofloxacin-ciprofloxacin and ofloxacin-norfloxacin binary mixtures by flow-injection chemiluminescence in combination with partial least squares multivariate calibration.

    Science.gov (United States)

    Murillo, J A; Alañón Molina, A; Muñoz de la Peña, A; Durán Merás, I; Jiménez Girón, A

    2007-09-01

    A flow-injection chemiluminescence (CL) method is described for the determination of ciprofloxacin (CIP), norfloxacin (NOR) and ofloxacin (OFL), commonly used antibiotics of the fluoroquinolones family. The method is based on the CL reaction of the fluoroquinolones with tris(2,2'-bipyridyl) ruthenium(II) and Ce (IV), in sulfuric acid medium. The maximum CL emission, given at 0.45 min for CIP, at 0.35 min for NOR and at 0.04 min for OFL, respectively, were measured, allowing the simple application of the proposed method to the routine analysis of the antibiotics. The methods were applied to the determination of CIP, NOR and OFL, in several pharmaceutical preparations, with very satisfactory results, and validated by a previously reported HPLC method. The time-resolved equipment allowed the measurement of the kinetic evolution of the chemiluminescence signals. In base to the differences in the kinetic behaviour of ofloxacin with respect to ciprofloxacin and norfloxacin, binary mixtures of the drugs were resolved by using the time-resolved chemiluminescence signals, in combination with first-order partial least-squares (PLS) multivariate calibration.

  20. Effects of Microporosity and Surface Chemistry on Separation Performances of N-Containing Pitch-Based Activated Carbons for CO2/N2 Binary Mixture

    Science.gov (United States)

    Lee, Min-Sang; Park, Mira; Kim, Hak Yong; Park, Soo-Jin

    2016-03-01

    In this study, N-containing pitch-based activated carbons (NPCs) were prepared using petroleum pitch with a low softening point and melamine with a high nitrogen content. The major advantage of the preparation method is that it enables variations in chemical structures and textural properties by steam activation at high temperatures. The adequate micropore structures, appropriate chemical modifications, and high adsorption enthalpies of NPCs are favorable for CO2 adsorption onto carbon surfaces. Furthermore, the structure generates a considerable gas/N-containing carbon interfacial area, and provides selective access to CO2 molecules over N2 molecules by offering an increased number of active sites on the carbon surfaces. The highest CO2/N2 selectivity, i.e., 47.5, and CO2 adsorption capacity for a CO2/N2 (0.15:0.85) binary gas mixture, i.e., 5.30 wt%, were attained at 298 K. The NPCs also gave reversible and durable CO2-capturing performances. All the results suggest that NPCs are promising CO2 sorbents, which can meet the challenges of current CO2 capture and separation techniques.