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Sample records for binary ionic mixtures

  1. 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.

  2. Diffusion of Magnetized Binary Ionic Mixtures at Ultracold Plasma Conditions

    Science.gov (United States)

    Vidal, Keith R.; Baalrud, Scott D.

    2017-10-01

    Ultracold plasma experiments offer an accessible means to test transport theories for strongly coupled systems. Application of an external magnetic field might further increase their utility by inhibiting heating mechanisms of ions and electrons and increasing the temperature at which strong coupling effects are observed. We present results focused on developing and validating a transport theory to describe binary ionic mixtures across a wide range of coupling and magnetization strengths relevant to ultracold plasma experiments. The transport theory is an extension of the Effective Potential Theory (EPT), which has been shown to accurately model correlation effects at these conditions, to include magnetization. We focus on diffusion as it can be measured in ultracold plasma experiments. Using EPT within the framework of the Chapman-Enskog expansion, the parallel and perpendicular self and interdiffusion coefficients for binary ionic mixtures with varying mass ratios are calculated and are compared to molecular dynamics simulations. The theory is found to accurately extend Braginskii-like transport to stronger coupling, but to break down when the magnetization strength becomes large enough that the typical gyroradius is smaller than the interaction scale length. This material is based upon work supported by the Air Force Office of Scientific Research under Award Number FA9550-16-1-0221.

  3. 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

  4. 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.

  5. Enhancement of nuclear reaction rates in asymmetric binary ionic mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Clerouin, J.; Arnault, P.; Desbiens, N. [CEA, DAM, DIF, Arpajon (France); White, A.; Ticknor, C.; Kress, J.D.; Collins, L.A. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM (United States)

    2017-11-15

    Using orbital-free molecular dynamics simulations we study the structure and dynamics of increasingly asymmetric mixtures such as hydrogen-carbon, hydrogen-aluminium, hydrogen-copper, and hydrogen-silver. We show that, whereas the heavy component structure is close to an effective one-component plasma (OCP), the light component appears more structured than the corresponding OCP. This effect is related to the crossover towards a Lorentz-type diffusion triggered by strongly coupled, highly charged heavy ions, and witnessed by the change of temperature scaling laws of diffusion. This over-correlation translates into an enhancement of nuclear reaction rates much higher than its classical OCP counterpart. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Phase behaviour, interactions, and structural studies of (amines+ionic liquids) binary mixtures.

    Science.gov (United States)

    Jacquemin, Johan; Bendová, Magdalena; Sedláková, Zuzana; Blesic, Marijana; Holbrey, John D; Mullan, Claire L; Youngs, Tristan G A; Pison, Laure; Wagner, Zdeněk; Aim, Karel; Costa Gomes, Margarida F; Hardacre, Christopher

    2012-05-14

    We present a study on the phase equilibrium behaviour of binary mixtures containing two 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide-based ionic liquids, [C(n)mim] [NTf(2)] (n=2 and 4), mixed with diethylamine or triethylamine as a function of temperature and composition using different experimental techniques. Based on this work, two systems showing an LCST and one system with a possible hourglass shape are measured. Their phase behaviours are then correlated and predicted by using Flory-Huggins equations and the UNIQUAC method implemented in Aspen. The potential of the COSMO-RS methodology to predict the phase equilibria was also tested for the binary systems studied. However, this methodology is unable to predict the trends obtained experimentally, limiting its use for systems involving amines in ionic liquids. The liquid-state structure of the binary mixture ([C(2)mim] [NTf(2)]+diethylamine) is also investigated by molecular dynamics simulation and neutron diffraction. Finally, the absorption of gaseous ethane by the ([C(2)mim][NTf(2)]+diethylamine) binary mixture is determined and compared with that observed in the pure solvents. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Thermodynamic properties of binary mixtures combining two pyridinium-based ionic liquids and two alkanols

    International Nuclear Information System (INIS)

    García-Mardones, Mónica; Barrós, Alba; Bandrés, Isabel; Artigas, Héctor; Lafuente, Carlos

    2012-01-01

    Highlights: ► Thermodynamic properties of an ionic liquid and an alkanol have been reported. ► The ionic liquids studied were 1-butyl-3 (or 4)-methylpyridinium tetrafluoroborate. ► The alkanols were methanol and ethanol. ► From measured data excess properties have been obtained and correlated. - Abstract: Densities and speeds of sound have been determined for the binary mixtures containing an ionic liquid (1-butyl-3-methylpyridinium tetrafluoroborate or 1-butyl-4-methylpyridinium tetrafluoroborate) and an alkanol (methanol or ethanol) over the temperature range (293.15 to 323.15) K. Excess volumes and excess isentropic compressibilities have been calculated from density and speed of sound data and correlated. All the mixtures show negative values for these excess properties. Furthermore, the isothermal (vapour + liquid) equilibrium has been measured at T = (303.15 and 323.15) K, and the corresponding activity coefficients and excess Gibbs functions have been obtained. In this case, positive excess Gibbs functions have been found. We have carried out an exhaustive interpretation of the experimental results in terms of structural and energetic effects taking also into account the thermodynamic information of pure compounds. Finally, in order to study the influence of both, the presence and the position of methyl group in the cation, we have compared the results of these systems with those obtained for the mixtures formed by 1-butylpyridinium tetrafluoroborate and methanol or ethanol.

  8. Thermophysical properties of binary mixtures of {ionic liquid 2-hydroxy ethylammonium acetate + (water, methanol, or ethanol)}

    International Nuclear Information System (INIS)

    Alvarez, Victor H.; Mattedi, Silvana; Martin-Pastor, Manuel; Aznar, Martin; Iglesias, Miguel

    2011-01-01

    Research highlights: → This paper reports the density and speed of sound data of binary mixtures {2-hydroxy ethylammonium acetate + (water, or methanol, or ethanol)} 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 {2-hydroxy ethylammonium acetate (2-HEAA) + (water, methanol, or ethanol)} 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.

  9. 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].

  10. Properties for binary mixtures of (acetamide + KSCN) eutectic ionic liquid with ethanol at several temperatures

    International Nuclear Information System (INIS)

    Liu, Baoyou; Liu, Yaru

    2016-01-01

    Graphical abstract: Viscosity deviation (Δη) against mole fraction of ethanol for [ethanol(1) + [(acetamide + KSCN)](2)] mixtures at several temperatures. The solid lines represent the corresponding correlation by the Redlich–Kister equation. - Highlights: • Density, viscosity and conductivity of (acetamide + KSCN) ethanol solution were measured. • V"E and Δη were calculated from the measured density and viscosity respectively. • V"E and Δη were both well fitted by a third order Redlich–Kister equation. • The conductivity was described by a Castell–Amis equation. - Abstract: Density, viscosity and conductivity were determined for the binary mixture of (acetamide + KSCN) eutectic ionic liquid with ethanol at T = (298.15, 303.15, 308.15, 313.15, 318.15) K and atmospheric pressure. The density, viscosity values decrease with the increase of temperature while the conductivity values increase over the whole concentration range. The density and viscosity values decrease monotonically with the increase of the mole content of ethanol. From the experimental values, excess molar volumes V"E and viscosity deviations Δη for the binary mixture were calculated and V"E and Δη were both well fitted by a third order Redlich–Kister equation. With the increase mole fraction of ethanol, the conductivity values of the mixture increase gradually first and then decrease dramatically, and the highest conductivity values appear at 0.8562 mol fraction of ethanol. The relationship between the conductivity and the mole fraction of ethanol can be well described by a Castell–Amis equation. The interactions with ethanol molecular and ions of (acetamide + KSCN) ionic liquid were discussed by FTIR spectra.

  11. Thermodynamic and spectroscopic studies on binary mixtures of imidazolium ionic liquids in ethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Bhupinder [Department of Chemistry, Kurukshetra University, Kurukshetra 136119, Haryana (India); Singh, Tejwant; Rao, K. Srinivasa [Salt and Marine Chemicals Division, Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), G.B. Marg, Bhavnagar 364002 (India); Pal, Amalendu, E-mail: palchem@sify.com [Department of Chemistry, Kurukshetra University, Kurukshetra 136119, Haryana (India); Kumar, Arvind, E-mail: arvind@csmcri.org [Salt and Marine Chemicals Division, Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), G.B. Marg, Bhavnagar 364002 (India)

    2012-01-15

    Highlights: > Macroscopic and molecular level interactions of imidazolium ionic liquids in ethylene glycol have been determined. > V{sub m}{sup E} is positive over the whole composition range for all the investigated mixtures. > Multiple hydrogen bonding interactions are prevailing between unlike components in mixtures of varying strengths. > Microscopic level interactions are not reflected in the mixing macroscopic behaviour. - Abstract: The thermodynamic behaviour of imidazolium based ionic liquids (ILs), 1-butyl-3-methylimidazolium chloride [C{sub 4}mim][Cl]; 1-octyl-3-methylimidazolium chloride [C{sub 8}mim][Cl], and 1-butyl-3-methylimidazolium methylsulfate [C{sub 4}mim][C{sub 1}OSO{sub 3}] in ethylene glycol [HOCH{sub 2}CH{sub 2}OH] (EG) have been investigated over the whole composition range at T = (298.15 to 318.15) K to probe the interactions in bulk. For the purpose, volumetric properties such as excess molar volume, V{sub m}{sup E}, apparent molar volume, V{sub {phi},i}, and its limiting values at infinite dilution, V{sub {phi},i}{sup {infinity}}, have been calculated from the experimental density measurements. The molecular scale interactions between ionic liquids and EG have been investigated through Fourier transform infrared (FTIR) and {sup 1}H NMR spectroscopy. The shift in the vibrational frequency for C-H stretch of aromatic ring protons of ILs and O-H stretch of EG molecules has been analysed. The NMR chemical shifts for various protons of RTILS or EG molecules and their deviations show multiple hydrogen bonding interactions of varying strengths between RTILs and EG in their binary mixtures.

  12. Features of non-congruent phase transition in modified Coulomb model of the binary ionic mixture

    International Nuclear Information System (INIS)

    Stroev, N E; Iosilevskiy, I L

    2016-01-01

    Non-congruent gas-liquid phase transition (NCPT) have been studied previously in modified Coulomb model of a binary ionic mixture C(+6) + O(+8) on a uniformly compressible ideal electronic background /BIM(∼)/. The features of NCPT in improved version of the BIM(∼) model for the same mixture on background of non-ideal electronic Fermi-gas and comparison it with the previous calculations are the subject of present study. Analytical fits for Coulomb corrections to equation of state of electronic and ionic subsystems were used in present calculations within the Gibbs-Guggenheim conditions of non-congruent phase equilibrium. Parameters of critical point-line were calculated on the entire range of proportions of mixed ions 0 < X < 1. Strong “distillation” effect was found for NCPT in the present BIM(∼) model. Just similar distillation was obtained in the variant of NCPT in dense nuslear matter. The absence of azeotropic compositions was revealed in studied variants of BIM(∼) in contrast to an explicit existence of the azeotropic compositions for the NCPT in chemically reacting plasmas and in astrophysical applications. (paper)

  13. Features of non-congruent phase transition in modified Coulomb model of the binary ionic mixture

    Science.gov (United States)

    Stroev, N. E.; Iosilevskiy, I. L.

    2016-11-01

    Non-congruent gas-liquid phase transition (NCPT) have been studied previously in modified Coulomb model of a binary ionic mixture C(+6) + O(+8) on a uniformly compressible ideal electronic background /BIM(∼)/. The features of NCPT in improved version of the BIM(∼) model for the same mixture on background of non-ideal electronic Fermi-gas and comparison it with the previous calculations are the subject of present study. Analytical fits for Coulomb corrections to equation of state of electronic and ionic subsystems were used in present calculations within the Gibbs-Guggenheim conditions of non-congruent phase equilibrium. Parameters of critical point-line were calculated on the entire range of proportions of mixed ions 0 distillation” effect was found for NCPT in the present BIM(∼) model. Just similar distillation was obtained in the variant of NCPT in dense nuslear matter. The absence of azeotropic compositions was revealed in studied variants of BIM(∼) in contrast to an explicit existence of the azeotropic compositions for the NCPT in chemically reacting plasmas and in astrophysical applications.

  14. Easy prediction of the refractive index for binary mixtures of ionic liquids with water or ethanol

    International Nuclear Information System (INIS)

    Rilo, E.; Domínguez-Pérez, M.; Vila, J.; Segade, L.; García, M.; Varela, L.M.; Cabeza, O.

    2012-01-01

    Highlights: ► We measure refractive index, n, in seven systems formed by IL + water or ethanol. ► Independently, theoretical estimations of the refractive index values were performed. ► To do that we use Gladstone–Dale and Newton models, relating n and density. ► We calculate density of each system from the value of the pure components. ► The agreement between experimental and calculated n values is about 99.8%. - Abstract: In this paper, we demonstrate that it is possible to know the refractive index, n D , of every given mixture of 1-alkyl-3methyl imidazolium tetrafluoroborate with water and ethanol just from the knowledge of the refractive index and density of pure components. To do that, we measured n D for seven different mixtures in all range of existing concentrations and, independently, we deduce n D theoretically. Both sets of values differ less than a 0.2% on average. The theoretical deduction takes into account that these mixtures are quasi-ideal from the molar volume point of view, as recently published, and so density for any composition of the mixture can be obtained with a precision better than 0.5% from the pure compounds value. Now we simply apply Newton or Gladstone–Dale models, which relate the refractive index of a binary mixture with its density from the value of both pure components, without any fitting parameter. Both models are very similar in form and in the values they deduce (less than a 0.2% of difference), but while that of Newton performs slightly better for ethanol mixtures, the model of Gladstone–Dale gives some better results for aqueous mixtures. We think that these results can be extended to the majority of ionic liquid plus solvent systems.

  15. Comparative study of physical properties of binary mixtures of halogen free ionic liquids with alcohols

    International Nuclear Information System (INIS)

    Alkhaldi, Khaled H.A.E.; Al-Jimaz, Adel S.; AlTuwaim, Mohammad S.

    2017-01-01

    Highlights: • Physical properties of binary mixtures of halogen free ILs with C 3 , C 4 and C 5 were invetigated. • 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. • Different mixing rules were used to predict the experimental refractive indices. - Abstract: Densities, refractive indices and speeds of sound along with their excess or deviation properties for both 1,3-dimethylimidazolium methylsulfate ([dmim][MeSO 4 ]) and 1-ethyl-3-methylimidazolium methylsulfate ([emim][MeSO 4 ]) with 1-propanol, 1-butanol and 1-pentanol over the entire range of mole fraction are reported at temperatures ranging from 298.15 K to 313.15 K and atmospheric pressure. Isentropic and excess isentropic compressibilities for both ionic liquids with 1-alcohols were calculated from the experimental results. Excess and deviation properties were further correlated using the Redlich-Kister polynomial. The measured speeds of sound were compared to the values obtained from Schaaffs' collision factor theory, Jacobson's intermolecular free length theory of solutions and Nomoto’s relation. In addition, the experimentally obtained refractive indices were compared to the calculated values using Lorentz-Lorenz, Dale-Gladstone and Eykman mixing rules.

  16. Volumetric and surface properties of pure ionic liquid n-octyl-pyridinium nitrate and its binary mixture with alcohol

    International Nuclear Information System (INIS)

    Jiang Haichao; Wang Jianying; Zhao Fengyun; Qi Guodi; Hu Yongqi

    2012-01-01

    Highlights: ► Density and surface tension of [Ocpy][NO 3 ] were measured. ► Thermal expansion coefficient, molecular volume, and standard entropies were obtained. ► The critical temperature and enthalpy of vaporization were discussed. ► Density and surface tension were measured for (ionic liquid + alcohols) mixtures. ► Excess molar volumes and surface tension deviations were fitted to Redlich–Kister equation. - Abstract: The density and surface tension for pure ionic liquid N-octyl-pyridinium nitrate were measured from (293.15 to 328.15) K. The coefficient of thermal expansion, molecular volume, standard entropies, and lattice energy were calculated from the experimental density values. The critical temperature, surface entropy, surface enthalpy, and enthalpy of vaporization were also studied from the experimental surface tension results. Density and surface tension were also determined for binary mixtures of (N-octyl-pyridinium nitrate + alcohol) (methanol, ethanol, and 1-butanol) systems over the whole composition range at 298.15 K and atmospheric pressure. Excess molar volumes and surface tension deviations for the binary systems have been calculated and were fitted to a Redlich–Kister equation to determine the fitting parameters and the root mean square deviations. The partial molar volume, excess partial molar volume, and apparent molar volume of the component IL and alcohol in the binary mixtures were also discussed.

  17. 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.

  18. 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.

  19. 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

  20. Excess molar volumes of binary mixtures (an ionic liquid + water): A review

    International Nuclear Information System (INIS)

    Bahadur, Indra; Letcher, Trevor M.; Singh, Sangeeta; Redhi, Gan G.; Venkatesu, Pannuru; Ramjugernath, Deresh

    2015-01-01

    Highlights: • Review of excess molar volumes for mixtures of (ionic liquids (ILs) + H 2 O). • 6 cation groups reviewed including imidazolium and pyrrolidinium groups. • 13 anions reviewed including tetraborate, triflate, and hydrogensulphate. • Effects of anion, cation, and temperature investigated. - Abstract: This review covers recent developments in the area of excess molar volumes for mixtures of {ILs (1) + H 2 O (2)} where ILs refers to ionic liquids involving cations: imidazolium, pyridinium, pyrrolidinium, piperidinium, morpholinium and ammonium groups; and anions: tetraborate, triflate, hydrogensulphate, methylsulphate, ethylsulphate, thiocyanate, dicyanamide, octanate, acetate, nitrate, chloride, bromide, and iodine. The excess molar volumes of aqueous ILs were found to cover a wide range of values for the different ILs (ranging from −1.7 cm 3 · mol −1 to 1.2 cm 3 · mol −1 ). The excess molar volumes increased with increasing temperature for all systems studied in this review. The magnitude and in some cases the sign of the excess molar volumes for all the aqueous ILs mixtures, apart from the ammonium ILs, were very dependent on temperature. This was particularly important in the dilute IL concentration region. It was found that the sign and magnitude of the excess molar volumes of aqueous ILs (for ILs with hydrophobic cations), was more dependent on the nature of the anion than on the cation

  1. 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

  2. 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_nC_1im][NTf_2] and GBL were discussed. • Angell strength parameter indicates [C_nC_1im][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.

  3. Surface tensions of binary mixtures of ionic liquids with bis(trifluoromethylsulfonyl)imide as the common anion

    International Nuclear Information System (INIS)

    Oliveira, M.B.; Domínguez-Pérez, M.; Cabeza, O.; Lopes-da-Silva, J.A.; Freire, M.G.; Coutinho, J.A.P.

    2013-01-01

    Highlights: • Novel data for the surface tensions of mixtures [C 4 mim][NTf 2 ] + [C 4 C 1 mim]/[C 3 mpy]/[C 3 mpyr]/[C 3 mpip][NTf 2 ] are presented. • γ were determined at a fixed temperature, 298.2 K, and at atmospheric pressure, for the whole composition range. • Surface tension deviations showed the near ideal behavior of the selected mixtures. • Gibbs adsorption isotherms showed the surface preferential adsorption of one ionic liquid over the other. -- Abstract: While values for thermophysical properties of ionic liquids are becoming widely available, data for ionic liquid mixtures are still scarce. In an effort to overcome this limitation and understand the behavior of ionic liquid mixtures, novel data for the surface tension of mixtures composed of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C 4 mim][NTf 2 ], with other ionic liquids with a common anion, namely 1-butyl-2,3-dimethylimidazolium, [C 4 C 1 mim] + , 3-methyl-1-propylpyridinium, [C 3 mpy] + , 1-methyl-1-propylpyrrolidinium, [C 3 mpyr] + , and 1-methyl-1-propylpiperidinium, [C 3 mpip] + , were measured at T = 298.2 K and atmospheric pressure over the entire composition range. From the surface tension deviations derived from the experimental results, it was possible to infer that the cation alkyl chain length of the second ionic liquid constituting the mixture has a stronger influence in the ideal mixture behavior than the type of family the ionic liquid cation belongs to. The Gibbs adsorption isotherms, estimated from the experimental values, show that the composition of the vapor–liquid interface is not the same as that of the bulk and that the interface is richer in the ionic liquid with the lowest surface tension, [C 4 mim][NTf 2

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

    OpenAIRE

    Emilio Gomez; Noelia Simón; Ángeles Domínguez; Maria Eugénia Macedo

    2013-01-01

    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 corresp...

  5. Phase Behaviour, Interactions, and Structural Studies of (Amines+Ionic Liquids) Binary Mixtures

    Czech Academy of Sciences Publication Activity Database

    Jacquemin, J.; Bendová, Magdalena; Sedláková, Zuzana; Holbrey, J.D.; Mullan, C.L.; Youngs, T.G.A.; Pison, L.; Wagner, Zdeněk; Aim, Karel; Costa Gomes, M.F.; Hardacre, Ch.

    2012-01-01

    Roč. 13, č. 7 (2012), s. 1825-1835 ISSN 1439-4235 R&D Projects: GA ČR GP203/09/P141; GA ČR GA104/07/0444; GA AV ČR IAA400720710; GA ČR GP104/06/P066 Grant - others:QUILL(GB) EP/D029538 Institutional research plan: CEZ:AV0Z40720504 Keywords : amines * interactions * ionic liquids Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.349, year: 2012

  6. 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

  7. 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.

  8. Properties of pure 1,1,3,3-tetramethylguanidine imidazole ionic liquid and its binary mixtures with alcohols at T = (293.15 to 313.15) K

    International Nuclear Information System (INIS)

    Chen, Jiayi; Chen, Lingxiao; Xu, Yingjie

    2015-01-01

    Highlights: • Densities and viscosities of [TMG]IM + alcohol mixtures were measured. • Coefficient of thermal expansion, molecular volume, standard entropy, and lattice energy were obtained. • Excess molar volumes and viscosity deviations were calculated and fitted to Redlich–Kister equation. • Other volumetric properties and excess Gibbs free energy of activation for viscous flow were deduced. • The intermolecular interactions between [TMG]IM and alcohols were analyzed. - Abstract: Densities and viscosities of the pure ionic liquid 1,1,3,3-tetramethylguanidine imidazole ([TMG]IM) and its binary mixtures with methanol, ethanol, 1-propanol, and 1-butanol were measured at temperatures from T = (293.15 to 313.15) K. The thermal expansion coefficient, molecular volume, standard entropy, and lattice energy of [TMG]IM were obtained from the experimental density value. The temperature dependence of the viscosity of [TMG]IM was fitted to the fluidity equation. Excess molar volumes V E and viscosity deviations Δη of the binary mixtures were calculated and fitted to the Redlich–Kister equation with satisfactory results. The result shows that the V E values of the binary mixtures are negative over the whole composition range, while Δη values have an S-shape deviation. Temperature has little effect on the V E of the systems, but it has significant effect on the Δη. Furthermore, the absolute values of V E for {[TMG]IM (1) + alcohol (2)} systems at the same temperature decrease with increasing carbon alkyl chain of the primary alcohol. Other derived properties, such as the apparent molar volumes, partial molar volumes, excess partial molar volumes, Gibbs free energy of activation for viscous flow, and excess Gibbs free energy of activation for viscous flow of the above-mentioned systems were also calculated

  9. Properties of pure n-butylammonium nitrate ionic liquid and its binary mixtures of with alcohols at T = (293.15 to 313.15) K

    International Nuclear Information System (INIS)

    Xu, Yingjie; Chen, Bin; Qian, Wu; Li, Haoran

    2013-01-01

    Highlights: ► Densities and viscosities of (N4NO 3 + alcohols) mixtures were measured. ► Coefficient of thermal expansion, molecular volume, standard entropy, and lattice energy were obtained. ► Excess molar volumes, viscosity deviations, and partial molar volumes were calculated. ► Redlich–Kister polynomial was used to correlate the excess properties. ► The intermolecular interactions between N4NO 3 and alcohols were analysed. -- Abstract: Values of the density and viscosity of the pure ionic liquid n-butylammonium nitrate (N4NO 3 ) and its binary mixtures with methanol, ethanol, 1-propanol, and 1-butanol were measured at temperature ranging from T = (293.15 to 313.15) K. The thermal expansion coefficient, molecular volume, standard entropy, and lattice energy of N4NO 3 were deduced from the experimental density results. The temperature dependence of the viscosity of N4NO 3 was fitted to the fluidity equation. Excess molar volumes V E and viscosity deviations Δη for the binary mixtures were calculated and fitted to the Redlich–Kister equation with satisfactory results. Both excess molar volumes and viscosity deviations show negative deviations for (N4NO 3 + alcohol) mixtures. The effect of the temperature and the size of the alcohol on the excess molar volumes and viscosity deviations are discussed and analysed. Other derived properties, such as the apparent molar volume, partial molar volume, excess partial molar volume, thermal expansion coefficient, and excess thermal expansion coefficient of the above-mentioned systems were also calculated

  10. Separation of toluene from n-heptane by liquid–liquid extraction using binary mixtures of [bpy][BF4] and [4bmpy][Tf2N] ionic liquids as solvent

    International Nuclear Information System (INIS)

    García, Silvia; Larriba, Marcos; García, Julián; Torrecilla, José S.; Rodríguez, Francisco

    2012-01-01

    Highlights: ► Binary mixtures of ionic liquids as extraction solvents of aromatics. ► [4bmpy][Tf 2 N] shows higher capacity but lower selectivity than sulfolane. ► [bpy][BF 4 ] shows lower capacity but higher selectivity than sulfolane. ► Mixed {[4bmpy][Tf 2 N] + [bpy][BF 4 ]} improves both extractive properties. - Abstract: The use of binary mixture of ionic liquids N-butylpyridinium tetrafluoroborate ([bpy][BF 4 ]), and 1-butyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide ([4bmpy][Tf 2 N]) in the liquid–liquid extraction of toluene from n-heptane has been investigated at 313.2 K and atmospheric pressure. The experimental capacity of extraction and selectivity for this binary mixture has proved to be intermediate to those corresponding to the pure ionic liquids, and they can be predicted using a logarithmic–linear model of solubility. Furthermore, the results showed that the use of binary mixture of {[bpy][BF 4 ] + [4bmpy][Tf 2 N]} at a mole solvent composition around 0.7 for [bpy][BF 4 ] improves both the capacity of extraction of toluene and the selectivity with respect to those of sulfolane, the organic solvent taken as a benchmark. Thus, this mixed ionic liquid could be likely to be used in the extraction of aromatic from aliphatic in replacement to sulfolane.

  11. Densities, viscosities, and excess properties of binary mixtures of two imidazolide anion functionalized ionic liquids with water at T = (293.15 to 313.15) K

    International Nuclear Information System (INIS)

    Chen, Lingxiao; Chen, Jiayi; Song, Zihao; Cui, Guokai; Xu, Yingjie; Wang, Xuhong; Liu, Jian

    2015-01-01

    Highlights: • Densities and viscosities of binary mixtures of [HDBU]IM and [BDBU]IM with water were measured. • Excess molar volumes and viscosity deviations were calculated and fitted to Redlich–Kister equation. • Other volumetric properties and excess Gibbs free energy of activation for viscous flow were deduced. • The intermolecular interactions between water and [HDBU]IM or [BDBU]IM were analyzed and compared. - Abstract: Densities and viscosities of binary mixtures of 8-hydrogen-1,8-diazabicyclo[5,4,0]-undec-7-enium imidazolide ([HDBU]IM) and 8-butyl-1,8-diazabicyclo[5,4,0]-undec-7-enium imidazolide ([BDBU]IM) ionic liquids (ILs) with water were measured at temperatures from T = (293.15 to 313.15) K. Excess molar volumes V"E and viscosity deviations Δη of the mixtures were calculated to study the intermolecular interactions and structural factors between ILs and water. The results show that the V"E values of the two mixtures are negative over the whole composition range, while the Δη values have positive deviations, indicating that the hydrogen bonding interactions between IL and water are dominant in the mixtures. Moreover, the absolute values of V"E (|V"E|) of {[HDBU]IM (1) + H_2O (2)} system are larger than those of {[BDBU]IM (1) + H_2O (2)} system at the same condition, indicating that the hydrogen bonding interactions between [HDBU]IM and water are stronger than those between [BDBU]IM and water. Both |V"E| and Δη values of the mixtures decrease with the increasing temperature, resulting from the decreasing the hydrogen bonding interactions between IL and water. Other derived properties of the studied systems, such as the apparent molar volumes, partial molar volumes, excess partial molar volumes, Gibbs free energy of activation for viscous flow, and excess Gibbs free energy of activation for viscous flow were also calculated from the experimental values.

  12. An experimental observation of the different behavior of ionic and neutral lines of iron as a function of number density in a binary carbon–iron mixture

    International Nuclear Information System (INIS)

    Sivakumar, P.; Taleh, L.; Markushin, Y.; Melikechi, N.; Lasue, J.

    2013-01-01

    We report on the dependence of the intensities of atomic and ionic lines emitted by a nanosecond laser-induced plasma on the atomic number densities of the constituents of a binary mixture formed of carbon and iron. We show that the packing density of the sample greatly affects the relative standard deviation of the emission lines. Furthermore, we show that the variation of the intensities of the C and Fe emission lines depends in a non-trivial way on the relative C–Fe concentration. The intensities of Fe neutral atomic lines behave differently than those of the ionic ones particularly at and above concentrations of 75%–80% Fe embedded in a carbon matrix. Unlike the emission from neutral Fe, those from ionic Fe yield a very sharp decrease followed by an equally strong increase of the emission lines over a relatively small range of relative concentration of C and Fe. To better investigate this effect, we have compared the results obtained with nanosecond-LIBS to those with femtosecond-LIBS and found that this phenomenon disappears. The physical interpretation of the sharp decrease followed by an equally sharp increase in the emission intensities from Fe ions as the concentration of Fe is increased requires more studies. - Highlights: ► The effects of the size of the particles on the fluctuations of the LIBS signals ► The variation of LIBS signals with the concentrations of Fe embedded in C is nontrivial. ► The intensities of neutral atomic lines can behave differently than those of ions

  13. Enhanced CO2 capture in binary mixtures of 1-alkyl-3-methylimidazolium tricyanomethanide ionic liquids with water

    NARCIS (Netherlands)

    Romanos, G.E.; Zubeir, L.F.; Likodimos, V.; Falaras, P.; Kroon, M.C.; Iliev, B.; Adamova, G.; Schubert, T.J.S.

    2013-01-01

    The absorption of carbon dioxide and water in the 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

  14. 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.

  15. Organosilica Membrane with Ionic Liquid Properties for Separation of Toluene/H₂ Mixture.

    Science.gov (United States)

    Hirota, Yuichiro; Maeda, Yohei; Yamamoto, Yusuke; Miyamoto, Manabu; Nishiyama, Norikazu

    2017-08-03

    In this study, we present a new concept in chemically stabilized ionic liquid membranes: an ionic liquid organosilica (ILOS) membrane, which is an organosilica membrane with ionic liquid-like properties. A silylated ionic liquid was used as a precursor for synthesis. The permselectivity, permeation mechanism, and stability of the membrane in the H₂/toluene binary system were then compared with a supported ionic liquid membrane. The membrane showed a superior separation factor of toluene/H₂ (>17,000) in a binary mixture system based on a solution-diffusion mechanism with improved durability over the supported ionic liquid membrane.

  16. A binary mixture operated heat pump

    International Nuclear Information System (INIS)

    Hihara, E.; Saito, T.

    1991-01-01

    This paper evaluates the performance of possible binary mixtures as working fluids in high- temperature heat pump applications. The binary mixtures, which are potential alternatives of fully halogenated hydrocarbons, include HCFC142b/HCFC22, HFC152a/HCFC22, HFC134a/HCFC22. The performance of the mixtures is estimated by a thermodynamic model and a practical model in which the heat transfer is considered in heat exchangers. One of the advantages of binary mixtures is a higher coefficient of performance, which is caused by the small temperature difference between the heat-sink/-source fluid and the refrigerant. The mixture HCFC142b/HCFC22 is promising from the stand point of thermodynamic performance

  17. Ionic-Liquid Based Separation of Azeotropic Mixtures

    DEFF Research Database (Denmark)

    Kulajanpeng, Kusuma; Suriyapraphadilok, Uthaiporn; Gani, Rafiqul

    2014-01-01

    methodology for the screening of ionic liquids (ILs) as entrainers for ILs-based separation processes in binary aqueous azeotropic systems (e.g., water + ethanol and water + isopropanol) is presented. Ionic liquids as entrainers were first screened based on a combination of criteria such as stabi......methodology for the screening of ionic liquids (ILs) as entrainers for ILs-based separation processes in binary aqueous azeotropic systems (e.g., water + ethanol and water + isopropanol) is presented. Ionic liquids as entrainers were first screened based on a combination of criteria...... [C1MIM][DMP]. For the final evaluation, the best candidates for aqueous systems were used as entrainers, and then the vapor-liquid equilibrium (VLE) of the ternary systems containing ILs was predicted by the Non Random Two Liquids (NRTL) model to confirm the breaking of the azeotrope. Based...... on minimum concentration of the ILs required to break the given azeotrope, the best ILs as entrainers for water + ethanol and water + isopropanol azeotropic mixtures were [C1MIM][DMP] and [C2MIM][N(CN)2], respectively....

  18. Effective Permeability of Binary Mixture of Carbon Dioxide and Methane and Pre-Dried Raw Biogas in Supported Ionic Liquid Membranes

    Czech Academy of Sciences Publication Activity Database

    Kárászová, Magda; Sedláková, Zuzana; Friess, K.; Izák, Pavel

    2015-01-01

    Roč. 153, OCT 16 (2015), s. 14-18 ISSN 1383-5866 R&D Projects: GA ČR GA14-12695S; GA MŠk LH14006 Institutional support: RVO:67985858 Keywords : supported ionic liquid membrane * biogas upgrading * real biogas Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.299, year: 2015

  19. New models for predicting thermophysical properties of ionic liquid mixtures.

    Science.gov (United States)

    Huang, Ying; Zhang, Xiangping; Zhao, Yongsheng; Zeng, Shaojuan; Dong, Haifeng; Zhang, Suojiang

    2015-10-28

    Potential applications of ILs require the knowledge of the physicochemical properties of ionic liquid (IL) mixtures. In this work, a series of semi-empirical models were developed to predict the density, surface tension, heat capacity and thermal conductivity of IL mixtures. Each semi-empirical model only contains one new characteristic parameter, which can be determined using one experimental data point. In addition, as another effective tool, artificial neural network (ANN) models were also established. The two kinds of models were verified by a total of 2304 experimental data points for binary mixtures of ILs and molecular compounds. The overall average absolute deviations (AARDs) of both the semi-empirical and ANN models are less than 2%. Compared to previously reported models, these new semi-empirical models require fewer adjustable parameters and can be applied in a wider range of applications.

  20. Solubility, density and excess molar volume of binary mixtures of aromatic compounds and common ionic liquids at T=283.15K and atmospheric pressure

    OpenAIRE

    Emilio J Gonzalez; Patricia Requejo; Filipa Maia; Ángeles Dominguez; Maria Eugénia Macedo

    2015-01-01

    In this work, the solubility of aromatic compounds (benzene, or toluene, or ethylbenzene, or o-xylene, or m-xylene, or p-xylene) in several ionic liquids (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, or 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, or 1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, or 1-propyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, or 1-ethyl-3-methylpyridinium ethylsulfate, or 1-hexyl-3-methylimidazolium dicyana...

  1. Acoustical, volumetric and osmotic properties of binary mixtures containing the ionic liquid 1-butyl-3-metylimidazolium dicyanamide mixed with primary and secondary alcohols

    OpenAIRE

    Noélia Calvar; Emilio J. González; Ángeles Domínguez; Eugénia A. Macedo

    2012-01-01

    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 binar...

  2. Acoustic, volumetric and osmotic properties of binary mixtures containing the ionic liquid 1-butyl-3-methylimidazolium dicyanamide mixed with primary and secondary alcohols

    OpenAIRE

    Noélia Calvar; Emilio J. González; Dominguez, A; Maria Eugénia Macedo

    2012-01-01

    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 binar...

  3. Osmotic coefficients of binary mixtures of four ionic liquids with ethanol or water at T = (313.15 and 333.15) K

    International Nuclear Information System (INIS)

    Calvar, Noelia; Gonzalez, Begona; Dominguez, Angeles; Macedo, Eugenia A.

    2009-01-01

    Measurements of osmotic coefficients of BmimCl (1-butyl-3-methylimidazolium chloride) and HmimCl (1-hexyl-3-methylimidazolium chloride) with ethanol and EmimEtSO 4 (1-ethyl-3-methylimidazolium ethylsulfate) and EmpyEtSO 4 (1-ethyl-3-methylpyridinium ethylsulfate) with water at T = (313.15 and 333.15) K are reported in this work. Vapour pressure and activity results of the studied binary systems are obtained from experimental measurements. The results for the osmotic coefficients are correlated using the extended Pitzer model modified by Archer and the modified NRTL (MNRTL) model. The standard deviations obtained with both models are also given. The parameters obtained with the extended Pitzer model of Archer are used to calculate the mean molal activity coefficients

  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. Capillary condensation and adsorption of binary mixtures.

    Science.gov (United States)

    Weinberger, B; Darkrim-Lamari, F; Levesque, D

    2006-06-21

    The adsorption of equimolar binary mixtures of hydrogen-carbon dioxide, hydrogen-methane, and methane-carbon dioxide in porous material models is determined by grand canonical Monte Carlo simulations. The material models have an adsorbent surface similar to that of nanofibers with a herringbone structure. Our main result, which is relevant for hydrogen purification and carbon dioxide capture, is that the adsorption selectivities calculated for the mixtures can differ significantly from those deduced from simulations of the adsorption of pure gases, in particular, when one of the adsorbed gases presents a capillary condensation induced by confinement within the pore network. A comparison of our data is also made with theoretical models used in the literature for predicting the properties of the mixture adsorption.

  6. Physicochemical Properties of Glycine-Based Ionic Liquid [QuatGly-OEt][EtOSO3] (2-Ethoxy-1-ethyl-1,1-dimethyl-2-oxoethanaminium ethyl sulfate and Its Binary Mixtures with Poly(ethylene glycol (Mw = 200 at Various Temperatures

    Directory of Open Access Journals (Sweden)

    Chung-Wen Kuo

    2011-12-01

    Full Text Available This work includes specific basic characterization of synthesized glycine-based Ionic Liquid (IL [QuatGly-OEt][EtOSO3] by NMR, elementary analysis and water content. Thermophysical properties such as density, ρ, viscosity, η, refractive index, n, and conductivity, κ, for the binary mixture of [QuatGly-OEt][EtOSO3] with poly(ethylene glycol (PEG [Mw = 200] are measured over the whole composition range. The temperature dependence of density and dynamic viscosity for neat [QuatGly-OEt][EtOSO3] and its binary mixture can be described by an empirical polynomial equation and by the Vogel-Tammann-Fucher (VTF equation, respectively. The thermal expansion coefficient of the ILs is ascertained using the experimental density results, and the excess volume expansivity is evaluated. The negative values of excess molar volume for the mixture indicate the ion-dipole interactions and packing between IL and PEG oligomer. The results of binary excess property (VmE and deviations (Δη, ∆xn, ∆Фn, ∆xR, and ∆ФR are discussed in terms of molecular interactions and molecular structures in the binary mixture.

  7. Physicochemical Properties of Glycine-Based Ionic Liquid [QuatGly-OEt][EtOSO3] (2-Ethoxy-1-ethyl-1,1-dimethyl-2-oxoethanaminium ethyl sulfate) and Its Binary Mixtures with Poly(ethylene glycol) (Mw = 200) at Various Temperatures

    Science.gov (United States)

    Wu, Tzi-Yi; Chen, Bor-Kuan; Hao, Lin; Lin, Yuan-Chung; Wang, H. Paul; Kuo, Chung-Wen; Sun, I-Wen

    2011-01-01

    This work includes specific basic characterization of synthesized glycine-based Ionic Liquid (IL) [QuatGly-OEt][EtOSO3] by NMR, elementary analysis and water content. Thermophysical properties such as density, ρ, viscosity, η, refractive index, n, and conductivity, κ, for the binary mixture of [QuatGly-OEt][EtOSO3] with poly(ethylene glycol) (PEG) [Mw = 200] are measured over the whole composition range. The temperature dependence of density and dynamic viscosity for neat [QuatGly-OEt][EtOSO3] and its binary mixture can be described by an empirical polynomial equation and by the Vogel-Tammann-Fucher (VTF) equation, respectively. The thermal expansion coefficient of the ILs is ascertained using the experimental density results, and the excess volume expansivity is evaluated. The negative values of excess molar volume for the mixture indicate the ion-dipole interactions and packing between IL and PEG oligomer. The results of binary excess property (VmE ) and deviations (Δη, Δxn, ΔΨn, ΔxR, and ΔΨR) are discussed in terms of molecular interactions and molecular structures in the binary mixture. PMID:22272102

  8. 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

  9. Phase Behavior of Mixtures of Ionic Liquids and Organic Solvents

    DEFF Research Database (Denmark)

    Abildskov, Jens; Ellegaard, Martin Dela; O’Connell, J.P.

    2010-01-01

    A corresponding-states form of the generalized van der Waals equation, previously developed for mixtures of an ionic liquid and a supercritical solute, is here extended to mixtures including an ionic liquid and a solvent (water or organic). Group contributions to characteristic parameters...... are implemented, leading to an entirely predictive method for densities of mixed compressed ionic liquids. Quantitative agreement with experimental data is obtained over wide ranges of conditions. Previously, the method has been applied to solubilities of sparingly soluble gases in ionic liquids and in organic...... solvents. Here we show results for heavier and more-than-sparingly solutes such as carbon dioxide and propane in ionic liquids....

  10. Amphiphile Meets Amphiphile: Beyond the Polar-Apolar Dualism in Ionic Liquid/Alcohol Mixtures.

    Science.gov (United States)

    Russina, Olga; Sferrazza, Alessio; Caminiti, Ruggero; Triolo, Alessandro

    2014-05-15

    The mesoscopic morphology of binary mixtures of ethylammonium nitrate (EAN), the protic ionic liquid par excellence, and methanol is explored using neutron/X-ray diffraction and computational techniques. Both compounds are amphiphilic and characterized by an extended hydrogen bonding network: surprisingly, though macroscopically homogeneous, these mixtures turn out to be mesoscopically highly heterogeneous. Our study reveals that even in methanol-rich mixtures, a wide distribution of clusters exists where EAN preserves its bulk, sponge-like morphology. Accordingly methanol does not succeed in fully dissociating the ionic liquid that keeps on organizing in a bulk-like fashion. This behavior represents the premises to the more dramatic phenomenology observed with longer alcohols that eventually phase separate from EAN. These results challenge the commonly accepted polar and apolar moieties segregation in ionic liquids/molecular liquids mixtures and the current understanding of technologically relevant solvation processes.

  11. Phase equilibrium and physical properties of biobased ionic liquid mixtures.

    Science.gov (United States)

    Toledo Hijo, Ariel A C; Maximo, Guilherme J; Cunha, Rosiane L; Fonseca, Felipe H S; Cardoso, Lisandro P; Pereira, Jorge F B; Costa, Mariana C; Batista, Eduardo A C; Meirelles, Antonio J A

    2018-02-28

    Protic ionic liquid crystals (PILCs) obtained from natural sources are promising compounds due to their peculiar properties and sustainable appeal. However, obtaining PILCs with higher thermal and mechanical stabilities for product and process design is in demand and studies on such approaches using this new IL generation are still scarce. In this context, this work discloses an alternative way for tuning the physicochemical properties of ILCs by mixing PILs. New binary mixtures of PILs derived from fatty acids and 2-hydroxy ethylamines have been synthesized here and investigated through the characterization of the solid-solid-[liquid crystal]-liquid thermodynamic equilibrium and their rheological and critical micellar concentration profiles. The mixtures presented a marked nonideal melting profile with the formation of solid solutions. This work revealed an improvement of the PILCs' properties based on a significant increase in the ILC temperature domain and the obtainment of more stable mesophases at high temperatures when compared to pure PILs. In addition, mixtures of PILs also showed significant changes in their non-Newtonian and viscosity profile up to 100 s -1 , as well as mechanical stability over a wide temperature range. The enhancement of the physicochemical properties of PILs here disclosed by such an approach leads to more new possibilities of their industrial application at high temperatures.

  12. 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.

  13. Dynamics of binary mixtures in inhomogeneous temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Gonnella, G; Piscitelli, A [Dipartimento di Fisica, Universita di Bari and Istituto Nazionale di Fisica Nucleare, Sezione di Bari, via Amendola 173, 70126 Bari (Italy); Lamura, A [Istituto Applicazioni Calcolo, CNR, via Amendola 122/D, 70126 Bari (Italy)

    2008-03-14

    A dynamical description for fluid binary mixtures with variable temperature and concentration gradient contributions to entropy and internal energy is given. By using mass, momentum and energy balance equations together with the standard expression for entropy production, a generalized Gibbs-Duhem relation is obtained which takes into account thermal and concentration gradient contributions. Then an expression for the pressure tensor is derived. As examples of applications, interface behavior and phase separation have been numerically studied in two dimensions neglecting the contributions of the velocity field. In the simplest case with a constant thermal gradient, the growth exponent for the averaged size of domains is found to have the usual value z = 1/3 and the domains appear elongated in the direction of the thermal gradient. When the system is quenched by contact with external walls, the evolution of temperature profiles in the system is shown and the domain morphology is characterized by interfaces perpendicular to the thermal gradient.

  14. 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

  15. Ecotoxicological characterization of polyoxyethylene glycerol ester non-ionic surfactants and their mixtures with anionic and non-ionic surfactants.

    Science.gov (United States)

    Ríos, Francisco; Fernández-Arteaga, Alejandro; Lechuga, Manuela; Fernández-Serrano, Mercedes

    2017-04-01

    This paper reports on a study that investigated the aquatic toxicity of new non-ionic surfactants derived from renewable raw materials, polyoxyethylene glycerol ester (PGE), and their binary mixtures with anionic and non-ionic surfactants. Toxicity of pure PGEs was determined using representative organisms from different trophic levels: luminescent bacteria (Vibrio fischeri), microalgae (Pseudokirchneriella subcapitata), and freshwater crustaceans (Daphnia magna). Relationships between toxicity and the structural parameters such as unit of ethylene oxide (EO) and hydrophilic-lipophilic balance (HLB) were evaluated. Critical micellar concentration (CMC) in the conditions of the toxicity test was also determined. It was found that the toxicity of the aqueous solutions of PGE decreased when the number of EO units in the molecule, HLB, and CMC increased. PGEs showed lower CMC in marine medium, and the toxicity to V. ficheri is lower when the CMC was higher. Given their non-polar nature, narcosis was expected to be the primary mode of toxic action of PGEs. For the mixture of surfactants, we observed that the mixtures with PGE that had the higher numbers of EO units were more toxic than the aqueous solutions of pure surfactants. Moreover, we found that concentration addition was the type of action more likely to occur for mixtures of PGE with lower numbers of EO units with non-ionic surfactants (alkylpolyglucoside and fatty alcohol ethoxylate), whereas for the mixture of PGE with lower EO units and anionic surfactant (ether carboxylic derivative), the most common response type was response addition. In case of mixtures involving amphoteric surfactants and PGEs with the higher numbers of EO units, no clear pattern with regard to the mixture toxicity response type could be observed.

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

    Indian Academy of Sciences (India)

    understanding in the molecular level. The origin of the .... analysis of inherent structures (IS) of binary mixture in ... liminary molecular dynamics simulation to equilibrate the system at ..... the clusters gradually increase as the concentration of.

  17. Modeling the effects of binary mixtures on survival in time.

    NARCIS (Netherlands)

    Baas, J.; van Houte, B.P.P.; van Gestel, C.A.M.; Kooijman, S.A.L.M.

    2007-01-01

    In general, effects of mixtures are difficult to describe, and most of the models in use are descriptive in nature and lack a strong mechanistic basis. The aim of this experiment was to develop a process-based model for the interpretation of mixture toxicity measurements, with effects of binary

  18. 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.

  19. 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

  20. Innovative aspects of protein stability in ionic liquid mixtures.

    Science.gov (United States)

    Kumar, Awanish; Venkatesu, Pannuru

    2018-06-01

    Mixtures of ionic liquids (ILs) have attracted our attention because of their extraordinary performances in extraction technologies and in absorbing large amount of CO 2 gas. It has been observed that when two or more ILs are mixed in different proportions, a new solvent is obtained which is much better than that of each component of ILs from which the mixture is obtained. Within a mixture of ILs, several unidentified interactions occur among several ions which give rise to unique solvent properties to the mixture. Herein, in this review, we have highlighted the utilization of the advantageous properties of the IL mixtures in protein stability studies. This approach is exceptional and opens new directions to the use of ILs in biotechnology.

  1. Measurement and correlation of critical properties for binary mixtures and ternary mixtures containing gasoline additives

    International Nuclear Information System (INIS)

    Wang, Lipu; Han, Kewei; Xia, Shuqian; Ma, Peisheng; Yan, Fangyou

    2014-01-01

    Highlights: • A high-pressure view cell was used to measure the critical properties of mixtures. • Three binary mixtures’ and three ternary mixtures’ critical properties were reported. • The experimental data of each system covered the whole mole fraction range. • The critical properties of the ternary mixtures were predicted with the PR–WS model. • Empirical equations were used to correlate the experimental results. - Abstract: The critical properties of three binary mixtures and three ternary mixtures containing gasoline additives (including methanol + 1-propanol, heptane + ethanol, heptane + 1-propanol, methanol + 1-propanol + heptane, methanol + 1-propanol + methyl tert-butyl ether (MTBE), and ethanol + heptane + MTBE) were determined by a high-pressure cell. All the critical lines of binary mixtures belong to the type I described by Scott and van Konynenburg. The system of methanol + 1-propanol showed little non-ideal behavior due to their similar molecular structures. The heptane + ethanol and heptane + 1-propanol systems showed visible non-ideal behavior for their great differences in molecular structure. The Peng–Robinson equation of state combined with the Wong–Sandler mixing rule (PR–WS) was applied to correlate the critical properties of binary mixtures. The critical points of the three ternary mixtures were predicted by the PR–WS model with the binary interaction parameters using the procedure proposed by Heidemann and Khalil. The predicted critical temperatures were in good agreement with the experimental values, while the predicted critical pressures differed from the measured values. The experimental values of binary mixtures were fitted well with the Redlich–Kister equation. The critical properties of ternary mixtures were correlated with the Cibulka’s equation, and the critical surfaces were plotted using the Cibulka’s equations

  2. Generation of two-dimensional binary mixtures in complex plasmas

    Science.gov (United States)

    Wieben, Frank; Block, Dietmar

    2016-10-01

    Complex plasmas are an excellent model system for strong coupling phenomena. Under certain conditions the dust particles immersed into the plasma form crystals which can be analyzed in terms of structure and dynamics. Previous experiments focussed mostly on monodisperse particle systems whereas dusty plasmas in nature and technology are polydisperse. Thus, a first and important step towards experiments in polydisperse systems are binary mixtures. Recent experiments on binary mixtures under microgravity conditions observed a phase separation of particle species with different radii even for small size disparities. This contradicts several numerical studies of 2D binary mixtures. Therefore, dedicated experiments are required to gain more insight into the physics of polydisperse systems. In this contribution first ground based experiments on two-dimensional binary mixtures are presented. Particular attention is paid to the requirements for the generation of such systems which involve the consideration of the temporal evolution of the particle properties. Furthermore, the structure of these two-component crystals is analyzed and compared to simulations. This work was supported by the Deutsche Forschungsgemeinschaft DFG in the framework of the SFB TR24 Greifswald Kiel, Project A3b.

  3. 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...

  4. Superlattice configurations in linear chain hydrocarbon binary mixtures

    Indian Academy of Sciences (India)

    Unknown

    Long-chain alkanes; binary mixtures; superlattices; discrete orientational changes. 1. Introduction ... tem and a model of superlattice configuration was proposed4, in terms of .... C18 system,4 the angle with value = 3⋅3° was seen to play an ...

  5. Transport benchmarks for one-dimensional binary Markovian mixtures revisited

    International Nuclear Information System (INIS)

    Malvagi, F.

    2013-01-01

    The classic benchmarks for transport through a binary Markovian mixture are revisited to look at the probability distribution function of the chosen 'results': reflection, transmission and scalar flux. We argue that the knowledge of the ensemble averaged results is not sufficient for reliable predictions: a measure of the dispersion must also be obtained. An algorithm to estimate this dispersion is tested. (author)

  6. Ionic liquids for separation of olefin-paraffin mixtures

    Science.gov (United States)

    Dai, Sheng; Luo, Huimin; Huang, Jing-Fang

    2013-09-17

    The invention is directed to an ionic liquid comprising (i) a cationic portion containing a complex of a silver (I) ion and one or more neutral ligands selected from organoamides, organoamines, olefins, and organonitriles, and (ii) an anionic portion having the chemical formula ##STR00001## wherein m and n are independently 0 or an integer of 1 or above, and p is 0 or 1, provided that when p is 0, the group --N--SO.sub.2--(CF.sub.2).sub.nCF.sub.3 subtended by p is replaced with an oxide atom connected to the shown sulfur atom. The invention is also directed to a method for separating an olefin from an olefin-paraffin mixture by passing the mixture through a layer of the ionic liquid described above.

  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. Structure and lifetimes in ionic liquids and their mixtures.

    Science.gov (United States)

    Gehrke, Sascha; von Domaros, Michael; Clark, Ryan; Hollóczki, Oldamur; Brehm, Martin; Welton, Tom; Luzar, Alenka; Kirchner, Barbara

    2018-01-01

    With the aid of molecular dynamics simulations, we study the structure and dynamics of different ionic liquid systems, with focus on hydrogen bond, ion pair and ion cage formation. To do so, we report radial distribution functions, their number integrals, and various time-correlation functions, from which we extract well-defined lifetimes by means of the reactive flux formalism. We explore the influence of polarizable force fields vs. non-polarizable ones with downscaled charges (±0.8) for the example of 1-butyl-3-methylimidazolium bromide. Furthermore, we use 1-butyl-3-methylimidazolium trifluoromethanesulfonate to investigate the impact of temperature and mixing with water as well as with the chloride ionic liquid. Smaller coordination numbers, larger distances, and tremendously accelerated dynamics are observed when the polarizable force field is applied. The same trends are found with increasing temperature. Adding water decreases the ion-ion coordination numbers whereas the water-ion and water-water coordination is enhanced. A domain analysis reveals that the nonpolar parts of the ions are dispersed and when more water is added the water clusters increase in size. The dynamics accelerate in general upon addition of water. In the ionic liquid mixture, the coordination number around the cation changes between the two anions, but the number integrals of the cation around the anions remain constant and the dynamics slow down with increasing content of the chloride ionic liquid.

  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. Shear viscosity of binary mixtures: The Gay-Berne potential

    Science.gov (United States)

    Khordad, R.

    2012-05-01

    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.

  14. Anomalous relaxation in binary mixtures: a dynamic facilitation picture

    International Nuclear Information System (INIS)

    Moreno, A J; Colmenero, J

    2007-01-01

    Recent computational investigations of polymeric and non-polymeric binary mixtures have reported anomalous relaxation features when both components exhibit very different mobilities. Anomalous relaxation is characterized by sublinear power-law behaviour for mean-squared displacements, logarithmic decay in dynamic correlators, and a striking concave-to-convex crossover in the latter by tuning the relevant control parameter, in analogy with predictions of the mode-coupling theory for state points close to higher-order transitions. We present Monte Carlo simulations on a coarse-grained model for relaxation in binary mixtures. The liquid structure is substituted by a three-dimensional array of cells. A spin variable is assigned to each cell, representing unexcited and excited local states of a mobility field. Changes in local mobility (spin flip) are permitted according to kinetic constraints determined by the mobilities of the neighbouring cells. We introduce two types of cell ('fast' and 'slow') with very different rates for spin flip. This coarse-grained model qualitatively reproduces the mentioned anomalous relaxation features observed for real binary mixtures

  15. Spectrophotometric determination of rare earths in binary mixtures

    International Nuclear Information System (INIS)

    Krasnova, A.V.; Shvarev, V.S.

    1978-01-01

    The possibility was investigated of using the reaction with brompyrogallol red (BPR) (dibrompyrogallosulfophthalein) for analyzing binary mixtures of rare earth metals close in ordinal numbers (La-Y, La-Eu, La-Sm, La-Nd, Nd-Y, Nd-Eu). Heavy REM are masked by nitrile-acetic acid (NAA). The experimental design method was used to determine optimum conditions. The optimizing parameters were the optical density measured with respect to water and the amount of the component bound into the complex. It was found that optimum conditions for the analysis of investigated mixtures differ only in the amount of NAA necessary to mask the heavy element [NAA]/[Sm 3+ ]=4; [NAA]/[Eu 3+ ]=5; [NAA]/Nb 3+ ]=10; [NAA]/[Y 3+ ]=2.5. The optimum acidity and the amount of BPR are always the same: pH 6.5; [BPR]/[La 3+ ]=[BPR]/[Nd 3+ ]=4. The given method for analyzing binary mixtures of lanthanoids surpasses considerably in sensitivity the methods based on intrinsic absorption spectra, while retaining the same reproducibility

  16. Microscopic dynamics of binary mixtures and quasi-colloidal systems

    International Nuclear Information System (INIS)

    Smorenburg, H.E.

    1996-01-01

    In the study on the title subject two questions are addressed. One is whether the microscopic dynamics of binary mixtures and quasi-colloidal systems can be understood theoretically with kinetic theories for equivalent hard sphere mixtures. The other question that arises is whether the similarity in the dynamics of dense simple fluids and concentrated colloidal suspensions also holds for binary mixtures and quasi-colloidal systems. To answer these questions, we have investigated a number of binary gas mixtures and quasi-colloidal system with different diameter ratios and concentrations. We obtain the experimental dynamic structure factors S expt (κ,ω) of the samples from inelastic neutron scattering. We compare S expt (κ,ω) with the dynamic structure S HS (κ,ω) of an equivalent hard sphere fluid, that we calculate with the Enskog theory. In chapter 2, 3 and 4 we study dense He-Ar gas mixtures (diameter ratio R=1.4, and mass ratio M=10) at low and high Ar concentrations. Experiment and kinetic theory are in good agreement. In chapter 5 we study dilute quasi-colloidal suspensions of fullerene C60 molecules dissolved in liquid CS2. The diameter ratio R=2.2 is larger than in previous experiments while the mass ratio M=9.5 is more or less the same. We obtain the self diffusion coefficient D S of one C60 molecule in CS2 and find D s ≤D SE ≤D E , with D E obtained from kinetic theory and D SE from the Stokes-Einstein description. It appears that both descriptions are relevant but not so accurate. In chapter 6 we study three dense mixtures of neopentane in 40 Ar (diameter ratio R=1.7, mass ratio M=2) at low and high neopentane concentrations. At low concentration, we find a diffusion coefficient of neopentane in Ar, which is in good agreement with kinetic theory and in moderate agreement with the Stokes-Einstein description. At high concentration the collective translational dynamics of neopentane shows a similar behaviour as in dense colloids and simple fluids

  17. Binary mixtures of condensates in generic confining potentials

    Energy Technology Data Exchange (ETDEWEB)

    Facchi, P [Dipartimento di Matematica and MECENAS, Universita di Bari, I-70125 Bari (Italy); Florio, G; Pascazio, S; Pepe, F V, E-mail: Francesco.Pepe@ba.infn.it [INFN, Sezione di Bari, I-70126 Bari (Italy)

    2011-12-16

    We study a binary mixture of Bose-Einstein condensates, confined in a generic potential, in the Thomas-Fermi approximation. We search for the zero-temperature ground state of the system, both in the case of fixed numbers of particles and fixed chemical potentials. For generic potentials, we analyze the transition from mixed to separated ground-state configurations as the inter-species interaction increases. We derive a simple formula that enables one to determine the location of the domain walls. Finally, we find criteria for the energetic stability of separated configurations, depending on the number and the position of the domain walls separating the two species. (paper)

  18. Binary mixtures of condensates in generic confining potentials

    Science.gov (United States)

    Facchi, P.; Florio, G.; Pascazio, S.; Pepe, F. V.

    2011-12-01

    We study a binary mixture of Bose-Einstein condensates, confined in a generic potential, in the Thomas-Fermi approximation. We search for the zero-temperature ground state of the system, both in the case of fixed numbers of particles and fixed chemical potentials. For generic potentials, we analyze the transition from mixed to separated ground-state configurations as the inter-species interaction increases. We derive a simple formula that enables one to determine the location of the domain walls. Finally, we find criteria for the energetic stability of separated configurations, depending on the number and the position of the domain walls separating the two species.

  19. Binary mixtures of condensates in generic confining potentials

    International Nuclear Information System (INIS)

    Facchi, P; Florio, G; Pascazio, S; Pepe, F V

    2011-01-01

    We study a binary mixture of Bose–Einstein condensates, confined in a generic potential, in the Thomas–Fermi approximation. We search for the zero-temperature ground state of the system, both in the case of fixed numbers of particles and fixed chemical potentials. For generic potentials, we analyze the transition from mixed to separated ground-state configurations as the inter-species interaction increases. We derive a simple formula that enables one to determine the location of the domain walls. Finally, we find criteria for the energetic stability of separated configurations, depending on the number and the position of the domain walls separating the two species. (paper)

  20. 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...... in the literature were found, even in a thermostatically controlled diffusion cell, recording spectra through circulating water. For the system benzene/acetone, the determined diffusion coefficients were in good agreement with the literature data. The limitations of the Raman method are discussed...

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

    DEFF Research Database (Denmark)

    Monsalvo, Matias Alfonso; Shapiro, Alexander

    2007-01-01

    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......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...... 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....

  2. Temperature dependence on mutual solubility of binary (methanol + limonene) mixture and (liquid + liquid) equilibria of ternary (methanol + ethanol + limonene) mixture

    International Nuclear Information System (INIS)

    Tamura, Kazuhiro; Li Xiaoli; Li Hengde

    2009-01-01

    Mutual solubility data of the binary (methanol + limonene) mixture at the temperatures ranging from 288.15 K close to upper critical solution temperature, and ternary (liquid + liquid) equilibrium (tie-lines) of the (methanol + ethanol + limonene) mixture at the temperatures (288.15, 298.15, and 308.15) K have been obtained. The experimental results have been represented accurately in terms of the extended and modified UNIQUAC models with binary parameters, compared with the UNIQUAC model. The temperature dependence of binary and ternary (liquid + liquid) equilibrium for the binary (methanol + limonene) and ternary (methanol + ethanol + limonene) mixtures could be calculated successfully using the extended and modified UNIQUAC model

  3. Physical properties of aqueous mixtures of the ionic 1-ethl-3-methyl imidazolium octyl sulfate: A new ionic rigid gel

    International Nuclear Information System (INIS)

    Cabeza, O.; Vila, J.; Rilo, E.; Domínguez-Pérez, M.; Otero-Cernadas, L.; López-Lago, E.; Méndez-Morales, T.; Varela, L.M.

    2014-01-01

    Graphical abstract: Phase diagram indicating three transitions temperatures: (liquid + gel) (dot symbols), (liquid + crystal) (square symbols) and (crystal + liquid) (triangle symbols) for the aqueous EMIM-OS mixtures. - Highlights: • We present the phase diagram of the system EMIM-octyl sulfate + water. • We show that a rigid gel phase appears for certain concentrations and temperatures. • That gel presents a smectic-like phase, being really a rigid gel crystal. • The gel is as electrical conductive as the liquid in spite of the viscosity change. • Density does not change at the (liquid + gel) transition. - Abstract: We report the existence of hydrophobically driven lyotropic rigid gel phase in aqueous mixtures of the ionic liquid (IL) 1-ethyl-3-methyl imidazolium octyl sulfate (EMIM-OS), and we characterize the physical properties of the gel phase by means of density, electrical conductivity and viscosity measurements. Also we include polarized microscopy images, showing the existence of a crystalline-like gel phase with the cations and anions (mainly the alkyl chain of this last ones) ordered in a fashion similar to a liquid crystal, which is induced by the presence of the water molecules. As was pointed out briefly in a previous paper, some of the mixtures of that system under goes a (liquid + gel) phase transition only in a quite narrow concentration interval: for ionic liquid molar fraction, x IL , from 0.09 to 0.5. Below x IL = 0.09 and above x IL = 0.5, the mixtures crystallize at low temperature becoming a hard solid crystal. Here we report the complete phase diagram of this binary system, as well as measurements of the temperature behavior of several physical properties around the (liquid + gel) and (liquid + crystal) transitions. Curiously enough, we did not detect any change in the temperature dependence of the measured magnitudes at the (liquid + gel) phase transition, but for viscosity, even in the case of the electrical conductivity

  4. Composition inversion in mixtures of binary colloids and polymer

    Science.gov (United States)

    Zhang, Isla; Pinchaipat, Rattachai; Wilding, Nigel B.; Faers, Malcolm A.; Bartlett, Paul; Evans, Robert; Royall, C. Patrick

    2018-05-01

    Understanding the phase behaviour of mixtures continues to pose challenges, even for systems that might be considered "simple." Here, we consider a very simple mixture of two colloidal and one non-adsorbing polymer species, which can be simplified even further to a size-asymmetrical binary mixture, in which the effective colloid-colloid interactions depend on the polymer concentration. We show that this basic system exhibits surprisingly rich phase behaviour. In particular, we enquire whether such a system features only a liquid-vapor phase separation (as in one-component colloid-polymer mixtures) or whether, additionally, liquid-liquid demixing of two colloidal phases can occur. Particle-resolved experiments show demixing-like behaviour, but when combined with bespoke Monte Carlo simulations, this proves illusory, and we reveal that only a single liquid-vapor transition occurs. Progressive migration of the small particles to the liquid phase as the polymer concentration increases gives rise to composition inversion—a maximum in the large particle concentration in the liquid phase. Close to criticality, the density fluctuations are found to be dominated by the larger colloids.

  5. Relationship between surface tension and refractive index in binary non-electrolyte mixtures

    International Nuclear Information System (INIS)

    Acevedo, I.L.; Pedrosa, G.C.; Katz, M.

    1990-01-01

    Lorentz-Lorenz equation for molecular refraction has been combined with Sugden's parachor equation for binary non-electrolyte mixtures at 298.15 K. The obtained equation has been shown successful in calculating values of surface tensions, by measuring refractive indices of the binary mixtures at the same mole fractions. The estimated error decreases when the mixtures present possible isorefractives. (Author) [es

  6. Direct numerical simulations of nucleate boiling flows of binary mixtures

    International Nuclear Information System (INIS)

    Didier Jamet; Celia Fouillet

    2005-01-01

    phenomena. Namely, it is numerically observed that, for binary mixtures involving small amounts of a quasi non-condensable gas, the large decrease of the heat transfer coefficient observed is mostly due to the concentration distribution close to the triple line. Therefore, for direct numerical simulations of nucleate boiling of binary mixtures to provide quantitative results, it is important to account for the variations of the interface temperature with the local concentration of the mixture components in the close vicinity of the triple line. This knowledge requires a better modeling of the triple line motion of binary mixtures during liquid-vapor phase-change, which is still a very difficult modeling task. (author)

  7. 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

  8. 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...

  9. Appearance of enhancement effect in adsorption of binary gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Sakano, T. [Ajinomoto General Foods, Inc., Tokyo (Japan); Tamon, H.; Okazaki, M. [Kyoto University, Kyoto (Japan)

    1997-10-20

    The properties of adsorbents and adsorbates contributing to the enhancement in adsorption of binary gas mixtures were experimentally investigated. It is found that adsorbent is required to maintain the phenolic hydroxyl group and the carbonyl group as acidic surface oxides on the carbon surface, and to have a microporous structure for the main adsorption sites. Each gas component is required to be chemisorbed on the phenolic hydroxyl group or the carbonyl group on the adsorbent, and that both components are adsorbed in the micropores together. From the characterization of adsorbents after adsorption-desorption runs, it is demonstrated that the adsorbates in the micropores exist at a higher density than in the bulk state through the promotion of micropore filling when adsorption enhancement appears. 17 refs., 7 figs., 5 tabs.

  10. Turbidity of a Binary Fluid Mixture: Determining Eta

    Science.gov (United States)

    Jacobs, Donald T.

    1996-01-01

    A ground based (1-g) experiment is in progress that will measure the turbidity of a density-matched, binary fluid mixture extremely close to its liquid-liquid critical point. By covering the range of reduced temperatures t equivalent to (T-T(sub c)) / T(sub c) from 10(exp -8) to 10(exp -2), the turbidity measurements will allow the critical exponent eta to be determined. No experiment has precisely determined a value of the critical exponent eta, yet its value is significant to theorists in critical phenomena. Relatively simple critical phenomena, as in the liquid-liquid system studied here, serve as model systems for more complex systems near a critical point.

  11. Combined physical and chemical absorption of carbon dioxide in a mixture of ionic liquids

    International Nuclear Information System (INIS)

    Pinto, Alicia M.; Rodríguez, Héctor; Arce, Alberto; Soto, Ana

    2014-01-01

    Highlights: • Carbon dioxide can be absorbed in mixtures of two ionic liquids: [C 2 mim][EtSO 4 ] and [C 2 mim][OAc]. • A combination of physical and chemical absorption mechanisms is observed. • The CO 2 absorption capacity of the mixture of ionic liquids decreases with increasing temperature. • [C 2 mim][EtSO 4 ] in the mixture prevents solidification of the product resulting from reaction of [C 2 mim][OAc] and CO 2 . • Density and viscosity studies of the mixture of ionic liquids also lead to synergies, in particular at low temperatures. - Abstract: Ionic liquids have attracted great interest recently as the basis of a potential alternative technology for the capture of carbon dioxide. Beyond the inherent tunability of properties of individual ionic liquids, a further strategy in optimising the ionic liquid sorbent for this application is the use of mixtures of ‘pure’ ionic liquids. Some ionic liquids absorb CO 2 physically, whereas others do so chemically. Both mechanisms of absorption present advantages and disadvantages for a CO 2 capture process operating in a continuous regime. In this work, a mixture of 1-ethyl-3-methylimidazolium acetate (an ionic liquid that reacts chemically with CO 2 ) and 1-ethyl-3-methylimidazolium ethylsulfate (an ionic liquid that absorbs CO 2 only through a physical mechanism) was investigated for the absorption of CO 2 as a function of temperature and at pressures up to 17 bar. The absorption/desorption studies were complemented by the characterisation of thermal and physical properties of the mixture of ionic liquids, which provide extra information on the interactions at a molecular level, and are also critical for the assessment of its suitability for a proposed process and for the subsequent process design

  12. 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

  13. Vapour pressures and osmotic coefficients of binary mixtures of 1-ethyl-3-methylimidazolium ethylsulfate and 1-ethyl-3-methylpyridinium ethylsulfate with alcohols at T = 323.15 K

    International Nuclear Information System (INIS)

    Calvar, Noelia; Gonzalez, Begona; Dominguez, Angeles; Macedo, Eugenia A.

    2009-01-01

    Osmotic coefficients of binary mixtures containing alcohols (ethanol, 1-propanol, and 2-propanol) and the ionic liquids 1-ethyl-3-methylimidazolium ethylsulfate and 1-ethyl-3-methylpyridinium ethylsulfate were determined at T = 323.15 K. Vapour pressure and activity coefficients of the studied systems were calculated from experimental data. The extended Pitzer model modified by Archer, and the modified NRTL model (MNRTL) were used to correlate the experimental data, obtaining standard deviations lower than 0.012 and 0.031, respectively. The mean molal activity coefficients and the excess Gibbs free energy of the studied binary mixtures were calculated from the parameters obtained with the extended Pitzer model of Archer.

  14. 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.

  15. Density, electrical conductivity, viscosity and excess properties of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide + propylene carbonate binary mixtures

    International Nuclear Information System (INIS)

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

    2014-01-01

    Highlights: • Densities of [bmim][NTf 2 ] mixtures with propylene carbonate were measured. • Excess properties were calculated. • Formation of hydrogen bonds between IL and PC was discussed. • Electrical conductivity and viscosity were also measured. • Influence of temperature and composition on mixture properties were studied. -- Abstract: Densities of binary liquid mixtures of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [bmim][NTf 2 ], with propylene carbonate (PC) were measured at temperatures from (293.15 to 323.15) K and at atmospheric pressure over the whole composition range. The electrical conductivity was measured in the range from (293.15 to 328.15) K. Also, viscosity of [bmim][NTf 2 ] + PC binary mixtures was measured from (298.15 to 333.15) K. Excess molar volumes, V E , have been obtained from the experimental densities and were fitted to Redlich–Kister polynomial equation. Other volumetric properties, such as isobaric thermal expansion coefficients, partial molar volumes, apparent molar volumes and partial molar volumes at infinite dilution have been also calculated, in order to obtain information about interactions between PC and selected ionic liquid. Results are discussed in order to understand the hydrogen bonds formation between components of the mixture

  16. Fine tuning the ionic liquid-vacuum outer atomic surface using ion mixtures.

    Science.gov (United States)

    Villar-Garcia, Ignacio J; Fearn, Sarah; Ismail, Nur L; McIntosh, Alastair J S; Lovelock, Kevin R J

    2015-03-28

    Ionic liquid-vacuum outer atomic surfaces can be created that are remarkably different from the bulk composition. In this communication we demonstrate, using low-energy ion scattering (LEIS), that for ionic liquid mixtures the outer atomic surface shows significantly more atoms from anions with weaker cation-anion interactions (and vice versa).

  17. Modeling of columnar and equiaxed solidification of binary mixtures

    International Nuclear Information System (INIS)

    Roux, P.

    2005-12-01

    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)

  18. Binary and ternary gas mixtures for use in glow discharge closing switches

    Science.gov (United States)

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

    1988-04-27

    Highly efficient binary and ternary gas mixtures for use in diffuse glow discharge closing switches are disclosed. The binary mixtures are combinations of helium or neon and selected perfluorides. The ternary mixtures are combinations of helium, neon, or argon, a selected perfluoride, and a small amount of gas that exhibits enhanced ionization characteristics. These mixtures are shown to be the optimum choices for use in diffuse glow discharge closing switches by virtue if the combines physio-electric properties of the mixture components. 9 figs.

  19. Effect of alkanolammonium formates ionic liquids on vapour liquid equilibria of binary systems containing water, methanol, and ethanol

    International Nuclear Information System (INIS)

    Li Xuemei; Shen Chong; Li Chunxi

    2012-01-01

    Highlights ► Vapour pressures for six ternary systems containing an IL were measured. ► Components studied were water, ethanol, methanol, and alkanolammonium formates. ► The isobaric VLE were predicted using the fitted binary NRTL parameters. ► The ILs studied can generate a promising salt effect on VLE of azeotrope. ► [HMEA][HCOO] might be used as a potential entrainer in extractive distillation. - Abstract: Vapour pressures were measured using a quasi-static ebulliometer for the pseudo-binary mixtures of (water + ethanol), (water + methanol), and (methanol + ethanol) containing an alkanolammonium-based ionic liquid (IL), namely, mono-ethanolammonium formate ([HMEA][HCOO]) and di-ethanolammonium formate ([HDEA][HCOO]), respectively, with fixed IL mass fraction of 0.30 and over the temperature ranges of (292.12 to 371.13) K. The vapour pressures of the IL-containing ternary systems were favourably correlated using the NRTL model with an overall average absolute relative deviation (AARD) of 0.0082. Further, the salt effects of [HMEA][HCOO] and [HDEA][HCOO] on isobaric vapour liquid equilibria (VLE) of azeotrope and close boiling mixture, especially for the mixtures of (water + ethanol) and (methanol + ethanol), were investigated and compared with other ILs in terms of the x′–y phase diagrams predicted with the binary NRTL parameters. It is demonstrated that the relative volatilities of ethanol to water and ethanol to methanol are enhanced, and [HMEA][HCOO] might be used as a promising entrainer for the efficient separation of ethanol aqueous solution by special rectification.

  20. 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.

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

    Indian Academy of Sciences (India)

    . Ultrasonic 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 / of four binary liquid ...

  2. On the Lyapunov stability of a plane parallel convective flow of a binary mixture

    Directory of Open Access Journals (Sweden)

    Giuseppe Mulone

    1991-05-01

    Full Text Available The nonlinear stability of plane parallel convective flows of a binary fluid mixture in the Oberbeck-Boussinesq scheme is studied in the stress-free boundary case. Nonlinear stability conditions independent of Reynolds number are proved.

  3. 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 mixtures of 1,2-diethoxyethane with chloroalkanes ... The Bloomfield and Dewan model has been used to calculate viscosity ...

  4. 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...

  5. Exact results in a lattice model of a binary reactant mixture

    International Nuclear Information System (INIS)

    Thomas, P.B.

    1995-01-01

    We study phase separation in a binary mixture of two particles, which can react with each other and form a third compound. We determine the exact phase boundaries for a restricted range of the interaction parameters

  6. Change of hydrogen bonding structure in ionic liquid mixtures by anion type

    Science.gov (United States)

    Cha, Seoncheol; Kim, Doseok

    2018-05-01

    Ionic liquid mixtures have gained attention as a way of tuning material properties continuously with composition changes. For some mixture systems, physicochemical properties such as excess molar volume have been found to be significantly different from the value expected by linear interpolation, but the origin of this deviation is not well understood yet. The microstructure of the mixture, which can range from an ideal mixture of two initial consisting ionic liquids to a different structure from those of pure materials, has been suggested as the origin of the observed deviation. The structures of several different ionic liquid mixtures are studied by IR spectroscopy to confirm this suggestion, as a particular IR absorption band (νC(2)-D) for the moiety participating in the hydrogen bonding changes sensitively with the change of the anion in the ionic liquid. The absorbance of νC(2)-D changes proportionally with the composition, and a relatively small excess molar volume is observed for the mixtures containing an electronegative halide anion. By contrast, the absorbance changes nonlinearly, and the excess molar volumes are larger for the mixtures of which one of the anions has multiple interaction sites.

  7. 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.

  8. Phase behaviour of the symmetric binary mixture from thermodynamic perturbation theory.

    Science.gov (United States)

    Dorsaz, N; Foffi, G

    2010-03-17

    We study the phase behaviour of symmetric binary mixtures of hard core Yukawa (HCY) particles via thermodynamic perturbation theory (TPT). We show that all the topologies of phase diagram reported for the symmetric binary mixtures are correctly reproduced within the TPT approach. In a second step we use the capability of TPT to be straightforwardly extended to mixtures that are nonsymmetric in size. Starting from mixtures that belong to the different topologies of symmetric binary mixtures we investigate the effect on the phase behaviour when an asymmetry in the diameters of the two components is introduced. Interestingly, when the energy of interaction between unlike particles is weaker than the interaction between like particles, the propensity for the solution to demix is found to increase strongly with size asymmetry.

  9. 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.

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

    African Journals Online (AJOL)

    Preferred Customer

    type polynomial equation to derive the binary coefficients and estimate the standard ... prepared for each system, and their densities and absolute viscosities were .... divided arbitrarily into three types, namely, chemical, physical, and structural.

  11. 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

  12. 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...

  13. Photoacoustic study of heated binary mixtures containing whey and skimmed-milk powders

    NARCIS (Netherlands)

    Doka, O.; Bicanic, D.; Frankhuizen, R.

    1999-01-01

    A novel methodology is proposed to determine the amount of whey powder in a binary mixture containing whey and skimmed-milk powders. This new approach is based on measurement of the amplitude of the photoacoustic (PA) signal obtained when the mixture is exposed to a controlled thermal treatment; the

  14. Dielectric and physiochemical study of binary mixture of nitrobenzene with toluene

    Science.gov (United States)

    Mohod, Ajay G.; Deshmukh, S. D.; Pattebahadur, K. L.; Undre, P. B.; Patil, S. S.; Khirade, P. W.

    2018-05-01

    This paper presents the study of binary mixture of Nitrobenzene (NB) with Toluene (TOL) for eleven different concentrations at room temperature. The determined Dielectric Constant (ɛ0) Density (ρ) and Refractive index (nD) values of binary mixture are used to calculate the excess properties i.e. Excess Dielectric Constant (ɛ0E), Excess Molar Volume (VmE), Excess Refractive Index (nDE) and Excess Molar Refraction (RmE) of mixture over the entire composition range and fitted to the Redlich-Kister equation. The Kirkwood Correlation Factor (geff) and other parameters were used to discuss the information about the orientation of dipoles and the solute-solvent interaction of binary mixture at molecular level over the entire range of concentration.

  15. 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

  16. 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 ...

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

    KAUST Repository

    Xu, Xinpeng; Thiele, Uwe; Qian, Tiezheng

    2015-01-01

    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

  18. Ternary liquid-liquid equilibria for mixtures of toluene + n-heptane + an ionic liquid

    NARCIS (Netherlands)

    Meindersma, G.W.; Podt, J.G.; de Haan, A.B.

    2006-01-01

    This research has been focused on a study of sulfolane and four ionic liquids as solvents in liquid–liquid extraction. Liquid–liquid equilibria data were obtained for mixtures of (sulfolane or 4-methyl-N-butylpyridinium tetrafluoroborate ([mebupy]BF4) or 1-ethyl-3-methylimidazolium ethylsulfate

  19. Densities of Pure Ionic Liquids and Mixtures: Modeling and Data Analysis

    DEFF Research Database (Denmark)

    Abildskov, Jens; O’Connell, John P.

    2015-01-01

    Our two-parameter corresponding states model for liquid densities and compressibilities has been extended to more pure ionic liquids and to their mixtures with one or two solvents. A total of 19 new group contributions (5 new cations and 14 new anions) have been obtained for predicting pressure...

  20. Second-moment sum rules for correlation functions in a classical ionic mixture

    NARCIS (Netherlands)

    Suttorp, L.G.; Ebeling, W.

    1992-01-01

    The complete set of second-moment sum rules for the correlation functions of arbitrarily high order describing a classical multi-component ionic mixture in equilibrium is derived from the grand-canonical ensemble. The connection of these sum rules with the large-scale behaviour of fluctuations in an

  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. Prediction of surface tension of binary mixtures with the parachor method

    Directory of Open Access Journals (Sweden)

    Němec Tomáš

    2015-01-01

    Full Text Available The parachor method for the estimation of the surface tension of binary mixtures is modified by considering temperature-dependent values of the parachor parameters. The temperature dependence is calculated by a least-squares fit of pure-solvent surface tension data to the binary parachor equation utilizing the Peng-Robinson equation of state for the calculation of equilibrium densities. A very good agreement between experimental binary surface tension data and the predictions of the modified parachor method are found for the case of the mixtures of carbon dioxide and butane, benzene, and cyclohexane, respectively. The surface tension is also predicted for three refrigerant mixtures, i.e. propane, isobutane, and chlorodifluoromethane, with carbon dioxide.

  4. Study of intermolecular interactions in binary mixtures of ethanol in methanol

    Science.gov (United States)

    Maharolkar, Aruna P.; Khirade, P. W.; Murugkar, A. G.

    2016-05-01

    Present paper deals with study of physicochemical properties like viscosity, density and refractive index for the binary mixtures of ethanol and methanol over the entire concentration range were measured at 298.15 K. The experimental data further used to determine the excess properties viz. excess molar volume, excess viscosity, excess molar refraction. The values of excess properties further fitted with Redlich-Kister (R-K Fit) equation to calculate the binary coefficients and standard deviation. The resulting excess parameters are used to indicate the presence of intermolecular interactions and strength of intermolecular interactions between the molecules in the binary mixtures. Excess parameters indicate structure making factor in the mixture predominates in the system.

  5. 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) (I(COM)), 1473 cm(-1) (I(COD)), 961 cm(-1) (I(HAP)) and 1282 cm(-1) (I(UA)) were used. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. 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.

  7. 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

  8. 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 ...

  9. 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 ...

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

    Indian Academy of Sciences (India)

    are fitted to the three different relaxation models [24–27] by the non-linear least squares fit method. It is observed that the Davidson–Cole model is adequate to describe major dispersion of the various solute and solvent mixtures over this fre- quency range. Static dielectric constant and dielectric relaxation time could be.

  11. 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 ...

  12. 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'.

  13. 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.

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

    International Nuclear Information System (INIS)

    Lazerges, Mathieu; Rietveld, Ivo B.; Corvis, Yohann; Ceolin, Rene; Espeau, Philippe

    2010-01-01

    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 o C with an enthalpy of 17.3 ± 0.5 kJ mol -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.

  15. 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...

  16. Recent developments in thermodynamics and thermophysics of non-aqueous mixtures containing ionic liquids. A review

    International Nuclear Information System (INIS)

    Heintz, Andreas

    2005-01-01

    Mixtures of ionic liquids with organic solvents exhibit a most interesting research area in thermodynamics. The increasing utilization of ionic liquids in chemical processes and separation processes requires reliable and systematic data of thermodynamic and thermophysical properties such as activity coefficients, VLE and LLE data, heats of mixing as well as gas solubility data, densities and transport properties like viscosity, electric conductivity and mutual diffusion coefficients. This review presents an survey of the most recent data material including current developments and aspects of research activities needed in the future

  17. 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.

  18. 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 ...

  19. 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

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

    Indian Academy of Sciences (India)

    parameter B/A of four binary liquid mixtures using Tong and Dong equation at high pressures and .... in general as regular or ideal as no recognized association takes place between the unlike molecules. In this case ... Using the definition and.

  1. 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 f...

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

    KAUST Repository

    Wang, Yu; Raj, Abhijeet Dhayal; Chung, Suk-Ho

    2015-01-01

    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

  3. Excess Molar Volumes and Viscosities of Binary Mixture of Diethyl Carbonate+Ethanol at Different Temperatures

    Institute of Scientific and Technical Information of China (English)

    MA Peisheng; LI Nannan

    2005-01-01

    The purpose of this work was to report excess molar volumes and dynamic viscosities of the binary mixture of diethyl carbonate (DEC)+ethanol. Densities and viscosities of the binary mixture of DEC+ethanol at temperatures 293.15 K-343.15 K and atmospheric pressure were determined over the entire composition range. Densities of the binary mixture of DEC+ethanol were measured by using a vibrating U-shaped sample tube densimeter. Viscosities were determined by using Ubbelohde suspended-level viscometer. Densities are accurate to 1.0×10-5 g·cm-3, and viscosities are reproducible within ±0.003 mPa·s. From these data, excess molar volumes and deviations in viscosity were calculated. Positive excess molar volumes and negative deviations in viscosity for DEC+ethanol system are due to the strong specific interactions.All excess molar vo-lumes and deviations in viscosity fit to the Redlich-Kister polynomial equation.The fitting parameters were presented,and the average deviations and standard deviations were also calculated.The errors of correlation are very small.It proves that it is valuable for estimating densities and viscosities of the binary mixture by the correlated equation.

  4. Noble gas, binary mixtures for commercial gas-cooled reactor systems

    International Nuclear Information System (INIS)

    El-Genk, M. S.; Tournier, J. M.

    2007-01-01

    Commercial gas cooled reactors employ helium as a coolant and working fluid for the Closed Brayton Cycle (CBC) turbo-machines. Helium has the highest thermal conductivity and lowest dynamic viscosity of all noble gases. This paper compares the relative performance of pure helium to binary mixtures of helium and other noble gases of higher molecular weights. The comparison is for the same molecular flow rate, and same operating temperatures and geometry. Results show that although helium is a good working fluid because of its high heat transfer coefficient and significantly lower pumping requirement, a binary gas mixture of He-Xe with M = 15 gm/mole has a heat transfer coefficient that is ∼7% higher than that of helium and requires only 25% of the number stages of the turbo-machines. The binary mixture, however, requires 3.5 times the pumping requirement with helium. The second best working fluid is He-Kr binary mixture with M = 10 gm/mole. It has 4% higher heat transfer coefficient than He and requires 30% of the number of stages in the turbo-machines, but requires twice the pumping power

  5. Binary Mixtures of Permanganate and Chlorinated Volatile Organic Compounds in Groundwater Samples: Sample Preservation and Analysis

    Science.gov (United States)

    Ground water samples collected at sites where in-situ chemical oxidation (ISCO) has been deployed may contain binary mixtures of ground water contaminants and permanganate (MnO4-), an oxidant injected into the subsurface to destroy the contaminant. Commingling of the oxidant and ...

  6. Study of structural and transport properties of argon, krypton, and their binary mixtures at different temperatures.

    Science.gov (United States)

    Ghimire, Sunil; Adhikari, Narayan Prasad

    2017-03-01

    Molecular dynamics simulation of argon, krypton, and their binary mixtures were performed at different temperatures and constant pressure (P = 1.013 bar) using GROMACS - Groningen Machine for Chemical Simulations. The gases are modeled by Lennard-Jones pair potential, with parameters taken from the literature. The study of radial distribution functions (RDFs) shows a single peak which indicates that there is no packing effect in gaseous state for argon, krypton, and their binary mixtures. The self-diffusion coefficients of argon and krypton is determined by using mean-square displacement(MSD) method and the mutual diffusion coefficients of binary mixtures are determined using Darken's relation. The values of simulated diffusion coefficients are compared with their corresponding theoretical values, numerical estimation, and experimental data. A good agreement between these sets of data is found. The diffusion coefficients obey Arrhenius behavior to a good extent for both pure components and binary mixtures. The values of simulated diffusion coefficient are used to estimate viscosities and thermal conductivities which agree with theoretical values, numerical estimation, and experimental data within 10 %. These results support that the LJ potential is sufficient for description of molecular interactions in argon and krypton.

  7. A globally accurate theory for a class of binary mixture models

    Science.gov (United States)

    Dickman, Adriana G.; Stell, G.

    The self-consistent Ornstein-Zernike approximation results for the 3D Ising model are used to obtain phase diagrams for binary mixtures described by decorated models, yielding the plait point, binodals, and closed-loop coexistence curves for the models proposed by Widom, Clark, Neece, and Wheeler. The results are in good agreement with series expansions and experiments.

  8. Computer simulation of solid-liquid coexistence in binary hard sphere mixtures

    NARCIS (Netherlands)

    Kranendonk, W.G.T.; Frenkel, D.

    1991-01-01

    We present the results of a computer simulation study of the solid-liquid coexistence of a binary hard sphere mixture for diameter ratios in the range 0·85 ⩽ ğa ⩽ 1>·00. For the solid phase we only consider substitutionally disordered FCC and HCP crystals. For 0·9425 < α < 1·00 we find a

  9. Behavior of the Thermodynamic Properties of Binary Mixtures near the Critical Azeotrope

    Directory of Open Access Journals (Sweden)

    Azzedine Abbaci

    2003-12-01

    Full Text Available Abstract: In this work we investigate the critical line of binary azeotropic mixtures of acetone-n-pentane. We pinpoint the abnormal behavior of the critical density line as a function of the mole fraction of one of the component and show its influence on other thermodynamic properties such as the volume, the enthalpy and the entropy.

  10. 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 ...

  11. An efficient binary ionic liquid based quasi solid-state electrolyte for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Chen, Junnian; Peng, Tianyou; Shi, Wenye; Li, Renjie; Xia, Jiangbin

    2013-01-01

    A novel binary ionic liquid electrolyte containing lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) and binary ionic liquids, which is composed of 1-butyl-3-methylimidazolium iodide (BMII) and 1-butyl-3-methylimidazolium thiocyanate (BMISCN), is developed for dye-sensitized solar cells (DSSCs). It is found that incorporation of LiTFSI as charge transfer promoter with BMII has positive effect on the interfacial charge transfer of the dye/TiO 2 film, further addition of BMISCN into the above composite electrolyte can take advantage of its low viscosity to enhance the ionic conductivity and reduce the interfacial charge transfer resistance, and a photovoltaic conversion efficiency of 5.55% is obtained from the solar cell fabricated with the optimized binary ionic liquid electrolyte without iodine participation under AM 1.5 illumination at 100 mW cm −2 , with a 108.6% improvement in the efficiency with lower resistance and higher ionic conductivity as compared to the solar cell fabricated with single BMII ionic liquid-based electrolyte. The above results should be attributed to the reduced charge recombination and the effective interfacial charge transfer in the solar cell

  12. 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

  13. 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

  14. 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.

  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. 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)

  17. 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.

  18. 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.

  19. Cooperative Effects of Zwitterionic-Ionic Surfactant Mixtures on the Interfacial Water Structure Revealed by Sum Frequency Generation Vibrational Spectroscopy.

    Science.gov (United States)

    Pan, Xuecong; Yang, Fangyuan; Chen, Shunli; Zhu, Xuefeng; Wang, Chuanyi

    2018-05-08

    Cooperative effects of a series of equimolar binary zwitterionic-ionic surfactant mixtures on the interfacial water structure at the air-water interfaces have been studied by sum frequency generation vibrational spectroscopy (SFG-VS). For zwitterionic surfactant palmityl sulfobetaine (SNC 16 ), anionic surfactant sodium hexadecyl sulfate (SHS), and cationic surfactant cetyltrimethylammonium bromide (CTAB) with the same length of alkyl chain, significantly enhanced ordering of interfacial water molecules was observed for the zwitterionic-anionic surfactant mixtures SNC 16 -SHS, indicating that SNC 16 interacts more strongly with SHS than with CTAB because of the strong headgroup-headgroup electrostatic attraction for SNC 16 -SHS. Meanwhile, the SFG amplitude ratio of methyl and methylene symmetric stretching modes was used to verify the stronger interaction between SNC 16 and SHS. The conformational order indicator increased from 0.64 for SNC 16 to 7.17 for SNC 16 -SHS but only 0.94 for SNC 16 -CTAB. In addition, another anionic surfactant sodium dodecyl sulfate (SDS) was introduced to study the influence of chain-chain interaction. Decreased SFG amplitude of interfacial water molecules for SNC 16 -SDS was observed. Therefore, both the headgroup-headgroup electrostatic interaction and chain-chain van der Waals attractive interaction of the surfactants play an important role in enhancing the ordering of interfacial water molecules. The results provided experimental and theoretical bases for practical applications of the surfactants.

  20. Uniform phases in fluids of hard isosceles triangles: One-component fluid and binary mixtures

    Science.gov (United States)

    Martínez-Ratón, Yuri; Díaz-De Armas, Ariel; Velasco, Enrique

    2018-05-01

    We formulate the scaled particle theory for a general mixture of hard isosceles triangles and calculate different phase diagrams for the one-component fluid and for certain binary mixtures. The fluid of hard triangles exhibits a complex phase behavior: (i) the presence of a triatic phase with sixfold symmetry, (ii) the isotropic-uniaxial nematic transition is of first order for certain ranges of aspect ratios, and (iii) the one-component system exhibits nematic-nematic transitions ending in critical points. We found the triatic phase to be stable not only for equilateral triangles but also for triangles of similar aspect ratios. We focus the study of binary mixtures on the case of symmetric mixtures: equal particle areas with aspect ratios (κi) symmetric with respect to the equilateral one, κ1κ2=3 . For these mixtures we found, aside from first-order isotropic-nematic and nematic-nematic transitions (the latter ending in a critical point): (i) a region of triatic phase stability even for mixtures made of particles that do not form this phase at the one-component limit, and (ii) the presence of a Landau point at which two triatic-nematic first-order transitions and a nematic-nematic demixing transition coalesce. This phase behavior is analogous to that of a symmetric three-dimensional mixture of rods and plates.

  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. Cosolvent effect on the dynamics of water in aqueous binary mixtures

    Science.gov (United States)

    Zhang, Xia; Zhang, Lu; Jin, Tan; Zhang, Qiang; Zhuang, Wei

    2018-04-01

    Water rotational dynamics in the mixtures of water and amphiphilic molecules, such as acetone and dimethyl sulfoxide (DMSO), measured by femtosecond infrared, often vary non-monotonically as the amphiphilic molecule's molar fraction changes from 0 to 1. Recent study has attributed the non-ideal water rotation with concentration in DMSO-water mixtures to different microscopic hydrophilic-hydrophobic segregation structure in water-rich and water-poor mixtures. Interestingly, the acetone molecule has very similar molecular structure to DMSO, but the extremum of the water rotational time in the DMSO-water mixtures significantly shifts to lower concentration and the rotation of water is much faster than those in acetone-water mixtures. The simulation results here shows that the non-ideal rotational dynamics of water in both mixtures are due to the frame rotation during the interval of hydrogen bond (HB) switchings. A turnover of the frame rotation with concentration takes place as the structure transition of mixture from the hydrogen bond percolation structure to the hydrophobic percolation structure. The weak acetone-water hydrogen bond strengthens the hydrophobic aggregation and accelerates the relaxation of the hydrogen bond, so that the structure transition takes places at lower concentration and the rotation of water is faster in acetone-water mixture than in DMSO-water mixture. A generally microscopic picture on the mixing effect on the water dynamics in binary aqueous mixtures is presented here.

  3. Structure of ionic liquid-water mixtures at interfaces: x-ray and neutron reflectometry studies

    International Nuclear Information System (INIS)

    Lauw, Yansen; Rodopoulos, Theo; Horne, Mike; Follink, Bart; Hamilton, Bill; Knott, Robert; Nelson, Andy

    2009-01-01

    Full text: Fundamental studies on the effect of water in ionic liquids are necessary since the overall performance of ionic liquids in many industrial applications is often hampered by the presence of water.[1] Based on this understanding, the surface and interfacial structures of 1-butyl-1methylpyrrolidinium trifluoromethylsulfonylimide [C4mpyr][NTf2] ionic liquid-water mixtures were probed using x-ray and neutron reflectometry techniques. At the gas-liquid surface, a thick cation+water layer was detected next to the phase boundary, followed by an increasing presence of anion towards the bulk. The overall thickness of the surface exhibits non-monotonic trends with an increasing water content, which explains similar phenomenological trends in surface tension reported in the literature.[2] At an electrified interface, the interfacial structure of pure ionic liquids probed by neutron reflectometry shows similar trends to those predicted by a mean-field model.[3] However, the presence of water within the electrical double-layer is less obvious, although it is widely known that water reduces electrochemical window of ionic liquids. To shed light on this issue, further studies are currently in progress.

  4. Divergent trend in density versus viscosity of ionic liquid/water mixtures: a molecular view from guanidinium ionic liquids.

    Science.gov (United States)

    Singh, Akhil Pratap; Gardas, Ramesh L; Senapati, Sanjib

    2015-10-14

    Ionic liquids (ILs) have shown great potential in the dissolution and stability of biomolecules when a low-to-moderate quantity of water is added. Hence, determining the thermophysical properties and understanding these novel mixtures at the molecular level are of both fundamental and practical importance. In this context, here we report the synthesis of two nontoxic guanidinium cation based ILs, tetramethylguanidinium benzoate [TMG][BEN] and tetramethylguanidinium salicylate [TMG][SAL], and present a detailed comparison of their thermophysical properties in the presence of water. The results show that the [TMG][SAL]/water mixtures have higher density and higher apparent molar volume, but a lower viscosity and higher compressibility than the [TNG][BEN]/water mixtures. The measured viscosity and compressibility data are explained from ab initio quantum mechanical calculations and liquid-phase molecular dynamics simulations, where salicylate anions of denser [TMG][SAL]/water were found to exist as isolated ions due to intramolecular H-bonding. On the contrary, intermolecular H-bonding among the benzoate anions and their strong tendency to form an extended H-bonding network with water made [TMG][BEN]/water solutions more viscous and less compressible. This study shows the importance of probing these emerging solvents at the molecular-to-atomic level, which could be helpful in their optimal usage for task-specific applications.

  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. Preferential solvation of fluorenone and 4-hydroxyfluorenone in binary solvent mixtures

    International Nuclear Information System (INIS)

    Jozefowicz, Marek; Heldt, Janina R.

    2003-01-01

    Preferential solvation of fluorenone and 4-hydroxyfluorenone in binary solvent mixtures has been studied using steady-state spectroscopic measurements. This study concerns the solvent-induced shift of the absorption and fluorescence spectra of both molecules in two solvent mixtures, i.e., cyclohexane-tetrahydrofuran and cyclohexane-ethanol. The first system contains polar solute molecules, fluorenone and 4-hydroxyfluorenone, in a mixture of polar aprotic (tetrahydrofuran) and non-polar (cyclohexane) solvents. In the second solvents mixture, hydrogen bonding with solute molecules (ethanol) may occur. The results of spectroscopic measurements are analysed using theoretical models of Bakshiev, Mazurenko and Suppan which describe preferential solvation phenomena. In the case of cyclohexane-tetrahydrofuran mixtures, the deviation from linearity in the absorption and fluorescence solvatochromic shifts vs. the solution polarity is due to non-specific dipolar solvent-solute interactions. For cyclohexane-ethanol binary mixtures, both non-specific and specific (hydrogen bond and proton-relay tautomerization) interactions contribute to the observed solvatochromism

  7. 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.

  8. Densities and viscosities for ionic liquids mixtures containing [eOHmim][BF4], [bmim][BF4] and [bpy][BF4

    International Nuclear Information System (INIS)

    Song, Dayong; Chen, Jing

    2014-01-01

    Highlights: • Targets of this research are ILs mixtures. • Densities and viscosities were measured for three ILs mixtures. • Excess molar properties were deduced from the experiments. • Viscosities were discussed by the ideal Grunberg and Nissan mixing law. - Abstract: Densities and viscosities of binary ionic liquids mixtures, 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([eOHmim][BF 4 ]) + 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF 4 ]), 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([eOHmim][BF 4 ]) + N-butylpyridinium tetrafluoroborate ([bpy][BF 4 ]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF 4 ]) + N-butylpyridinium tetrafluoroborate ([bpy][BF 4 ]) were measured over the entire mole fraction from T = (298.15 to 343.15) K. The excess molar volumes were calculated and correlated by Redlich–Kiser polynomial expansions. The viscosities for pure ionic liquids were analyzed by means of the Vogel–Tammann–Fulcher equation and ideal mixing rules were applied for the ILs mixtures

  9. 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

  10. Thermophysical properties of binary mixtures of N,N-dimethylformamide with three cyclic ethers

    Directory of Open Access Journals (Sweden)

    Sinha Biswajit

    2013-01-01

    Full Text Available Densities and viscosities of the binary mixtures consisting of tetrahydrofuran (THF, 1,3-dioxolane (1,3-DO and 1,4-dioxane (1,4-DO with N,N-dimethylformamide (DMF over the entire range of composition were measured at temperatures 298.15, 308.15 and 318.15 K and at atmospheric pressure. Ultrasonic speeds of sound of these binary mixtures were measured at ambient temperature and atmospheric pressure (T = 298.15 K and P = 1.01×105 Pa. The various experimental data were utilized to derive excess molar volumes (VmE, excess viscosities (ηE, and excess isentropic compressibilities (κsE. Using the excess molar volumes (VmE, excess partial molar volumes (and and excess partial molar volumes at infinite dilution (and of each liquid component in the mixtures were derived and discussed. Excess molar volumes (VmE as a function of composition at ambient temperature and atmospheric pressure were used further to test the applicability of the Prigogine-Flory-Patterson (PFP theory to the experimental binaries. The excess properties were found to be either negative or positive depending on the nature of molecular interactions and structural effects of liquid mixtures. Em,1V Em,2VE0,m,1VE0,m,2V.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Low-temperature behaviour of the Kob-Andersen binary mixture

    International Nuclear Information System (INIS)

    Ashwin S S; Sastry, Srikanth

    2003-01-01

    The dynamical behaviours of glass-forming liquids have been analysed extensively via computer simulations of model liquids, among which the Kob-Andersen binary Lennard-Jones mixture has been a widely studied system. Typically, studies of this model have been restricted to temperatures above the mode coupling temperature. Preliminary results concerning the dynamics of the Kob-Andersen binary mixture are presented at temperatures that extend below the mode coupling temperature, along with properties of the local energy minima sampled. These results show that a crossover in the dynamics occurs alongside changes in the properties of the inherent structures sampled. Furthermore, a crossover is observed from non-Arrhenius behaviour of the diffusivity above the mode coupling temperature to Arrhenius behaviour at lower temperatures

  16. Simultaneous spectrophotometric determination of binary mixtures of surfactants using continuous wavelet transformation

    International Nuclear Information System (INIS)

    Afkhami, Abbas; Nematollahi, Davood; Madrakian, Tayyebeh; Abbasi-Tarighat, Maryam; Hajihadi, Mitra

    2009-01-01

    This work presents a simple, rapid, and novel method for simultaneous determination of binary mixtures of some surfactants using continuous wavelet transformation. The method is based on the difference in the effect of surfactants Cetyltrimethylammoniumbromide (CTAB), dodecyl trimethylammonium bromide (DTAB), cetylpyridinium bromide (CPB) and TritonX-100 (TX-100) on the absorption spectra of complex of Beryllium with Chrome Azurol S (CAS) at pH 5.4. Binary mixtures of CTAB-DTAB, DTAB-CPB and CTAB-TX-100 were analyzed without prior separation steps. Different mother wavelets from the family of continuous wavelet transforms were selected and applied under the optimal conditions for simultaneous determinations. The proposed methods, under the working conditions, were successfully applied to simultaneous determination of surfactants in hair conditioner and mouthwash samples.

  17. 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.

  18. 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

  19. Physical properties and solubility parameters of 1-ethyl-3-methylimidazolium based ionic liquids/DMSO mixtures at 298.15 K

    Science.gov (United States)

    Saba, H.; Yumei, Z.; Huaping, W.

    2015-12-01

    Densities, refractive indices, conductivities and viscosities of binary mixtures of 1-ethyl-3-methylimidazolium-based ionic liquids (ILs) with dimethyl sulfoxide at 298.15 K are reported. Excess molar volumes have been calculated from experimental data and were fitted with Redlich-Kister equation. The density and refractive index were found to increase with increasing concentration in all cases except [EMIM]COOH. The free mobility of ions has found to enhance conductivity and decrease viscosity to varying extent in all mixtures being studied. It has been observed that solubility parameters, dielectric constants and nature of anions of ILs being used play a vital role in determining the subsequent characteristics. As DMSO has high dielectric constant therefore, it was able to form interactions with most of ILs except with [EMIM]COOH due to anomalous nature of anion.

  20. 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...

  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. 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®.

  3. Excess Molar Volume of Binary Mixtures of Methylheptenone+Alkanols at 298.15 K

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Excess molar volume(VE) data on binary liquid mixtures of methylheptenone (MHO) with methanol, ethanol, n-propanol or n-butanol have been determined from the density measurements at 298.15 K and atmospheric pressure. The values of VE in all the systems over the entire composition range are quantified by the Redlich-Kister equation. The effects of the chain length of alkanols on VE are discussed.

  4. 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...

  5. Properties of noble gases and binary mixtures for closed Brayton Cycle applications

    International Nuclear Information System (INIS)

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

    2008-01-01

    A review is conducted of the properties of the noble gases, helium, neon, argon, krypton and xenon, and their binary mixtures at pressures from 0.1 to 20 MPa and temperatures up to 1400 K. An extensive database of experimental measurements is compiled and used to develop semi-empirical properties correlations. The correlations accurately account for the effects of pressure and temperature on the thermodynamic and transport properties of these gases for potential uses in space (∼2 MPa and up to 1400 K) and terrestrial (∼7.0 MPa and up to 1200 K) applications of Closed Brayton Cycle (CBC). The developed correlations are based on the Chapman-Enskog kinetic theory for dilute gases, and on the application of the law of corresponding states to account for the dependence of properties on pressure. The correlations use the critical temperature and density of the gases as scaling parameters, and their predictions are compared with the compiled database. At temperatures ≥400 K and pressures ≤2 MPa in CBC space power systems, He and Ne, and the binary mixtures of He-Xe and He-Kr with molecular weights ≤40 g/mole behave essentially like a perfect gas, and the error of neglecting the effect of pressure on their compressibility factor, specific heats and transport properties is ≤1%. At a typical operating pressure of 7.0 MPa and up to 1200 K in terrestrial CBC power plants, neglecting the effect of pressure can result in ∼4% error in the properties of noble gases and the binary mixtures of He-Xe and He-Kr with molecular weights ≤40 g/mole, and as much as 20% error for pure argon. Therefore, when operating at pressures >2.0 MPa and/or using noble gases or binary mixtures with molecular weights > 40 g/mole, the present correlations should be used to accurately predict the thermodynamic and transport properties

  6. 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.

  7. Investigation of Boiling Heat Transfer of Binary Mixture from Vertical Tube Embedded in porous Media

    Institute of Scientific and Technical Information of China (English)

    HailongMo; TongzeMa; 等

    1996-01-01

    Ethanol-water binary mixtures with 7 different mole fractions of ethanol ranging from 0 to 1 were adopted as testing liquids in the experiment.The vertical heating tube was inserted in porous matrix composed of five well sorted glass beads whise diameters range from 0.5 to 4.3mm.Due to the effect of composition,the trend of combination of vapor bubbles was reduced.resulting in the increase of peak heat flux of binary mixture,With the increase of ethanol mole fraction,0.5mm diameter bead of peak heat flux of binary mixture.with the increase of ethanol mole fraction.0.5mm diameter bead had lower value of peak heat flux,while for pure liquid the critical state is difficult to appear,with given diameter of glass bead,there existed an optimum value of mole fraction of ethanol,which was decreased with the increase of bead diameter,A dimensionless heat transfer coefficient was predicted through the introduction of a dimensionless parameter of porous matrix which agreed with the experimental results satisfactorily.

  8. Excess molar volume and viscosity deviation for binary mixtures of γ-butyrolactone with dimethyl sulfoxide

    International Nuclear Information System (INIS)

    Krakowiak, Joanna; Śmiechowski, Maciej

    2017-01-01

    Highlights: • Densities and viscosities of DMSO-GBL binary liquid mixtures were measured. • The volumetric parameters and excess quantities were obtained. • Ab initio calculations were performed for single molecules and dimers in the studied mixture. • The interactions in solutions are weaker than in pure solvents. - Abstract: The densities of binary liquid mixtures of dimethyl sulfoxide and γ-butyrolactone at (293.15, 298.15, 303.15 and 313.15) K and viscosity at T = 298.15 K have been measured at atmospheric pressure over the entire range of concentration. From these data the excess molar volumes V E at (293.15, 298.15, 303.15 and 313.15) K and the viscosity deviation, the excess entropy, and the excess Gibbs energy of activation for viscous flow at T = 298.15 K have been determined. These data were mathematically represented by the Redlich-Kister polynomial. Partial and apparent molar volumes have been calculated for better understanding of the interactions in the binary systems. The obtained data indicate the lack of specific interactions between unlike molecules, which seem to be a little weaker as compared to the interactions in pure solvents.

  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. 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

  11. Mixtures of glyme and aprotic-protic ionic liquids as electrolytes for energy storage devices

    Science.gov (United States)

    Stettner, T.; Huang, P.; Goktas, M.; Adelhelm, P.; Balducci, A.

    2018-05-01

    Ionic liquids (ILs) have been proven to be promising electrolytes for electrochemical energy storage devices such as supercapacitors and lithium ion batteries. In the last years, due to deficiency in storage of lithium on earth, innovative systems, such as sodium-based devices, attracted considerable attention. IL-based electrolytes have been proposed also as electrolytes for these devices. Nevertheless, in the case of these systems, the advantages and limits of IL-based electrolytes need to be further investigated. In this work we report an investigation about the chemical-physical properties of mixtures containing bis(2-methoxyethyl)ether diglyme (2G), which is presently considered as one of the most interesting solvents for sodium-based devices, and the ionic liquids 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI) and 1-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PyrH4TFSI). The conductivities, viscosities, and densities of several mixtures of 2G and these ILs have been investigated. Furthermore, their impact on the electrochemical behaviour of activated carbon composite electrodes has been considered. The results of this investigation indicate that these mixtures are promising electrolytes for the realization of advanced sodium-based devices.

  12. Spectroscopic and Chemometric Analysis of Binary and Ternary Edible Oil Mixtures: Qualitative and Quantitative Study.

    Science.gov (United States)

    Jović, Ozren; Smolić, Tomislav; Primožič, Ines; Hrenar, Tomica

    2016-04-19

    The aim of this study was to investigate the feasibility of FTIR-ATR spectroscopy coupled with the multivariate numerical methodology for qualitative and quantitative analysis of binary and ternary edible oil mixtures. Four pure oils (extra virgin olive oil, high oleic sunflower oil, rapeseed oil, and sunflower oil), as well as their 54 binary and 108 ternary mixtures, were analyzed using FTIR-ATR spectroscopy in combination with principal component and discriminant analysis, partial least-squares, and principal component regression. It was found that the composition of all 166 samples can be excellently represented using only the first three principal components describing 98.29% of total variance in the selected spectral range (3035-2989, 1170-1140, 1120-1100, 1093-1047, and 930-890 cm(-1)). Factor scores in 3D space spanned by these three principal components form a tetrahedral-like arrangement: pure oils being at the vertices, binary mixtures at the edges, and ternary mixtures on the faces of a tetrahedron. To confirm the validity of results, we applied several cross-validation methods. Quantitative analysis was performed by minimization of root-mean-square error of cross-validation values regarding the spectral range, derivative order, and choice of method (partial least-squares or principal component regression), which resulted in excellent predictions for test sets (R(2) > 0.99 in all cases). Additionally, experimentally more demanding gas chromatography analysis of fatty acid content was carried out for all specimens, confirming the results obtained by FTIR-ATR coupled with principal component analysis. However, FTIR-ATR provided a considerably better model for prediction of mixture composition than gas chromatography, especially for high oleic sunflower oil.

  13. Experimental determination of (p, ρ, T) data for binary mixtures of methane and helium

    International Nuclear Information System (INIS)

    Hernández-Gómez, R.; Tuma, D.; Segovia, J.J.; Chamorro, C.R.

    2016-01-01

    Highlights: • Accurate density data for two binary mixtures of methane and helium are presented. • Experimental data are compared with the densities calculated from different EOS. • Deviations from GERG-2008 exceeded the 3% for some points. • Deviations from AGA8-DC92 did not exceed the 0.3% at any experimental point. • The relative deviations are clearly higher for GERG-2008 than for AGA8-DC92. - Abstract: The basis for the development and evaluation of equations of state for mixtures is experimental data for several thermodynamic properties. The quality and the availability of experimental data limit the achievable accuracy of the equation. Referring to the fundamentals of GERG-2008 wide-range equation of state, no suitable data were available for many mixtures containing secondary natural gas components. This work provides accurate experimental (p, ρ, T) data for two binary mixtures of methane with helium (0.95 (amount-of-substance fraction) CH_4 + 0.05 He and 0.90 CH_4 + 0.10 He). Density measurements were performed at temperatures between (250 and 400) K and pressures up to 20 MPa by using a single-sinker densimeter with magnetic suspension coupling. Experimental data were compared with the corresponding densities calculated from the GERG-2008 and the AGA8-DC92 equations of state. Deviations from GERG-2008 were found within a 2% band for the (0.95 CH_4 + 0.05 He) mixture but exceeded the 3% limit for the (0.95 CH_4 + 0.05 He) mixture. The highest deviations were observed at T = 250 K and pressures between (17 and 19) MPa. Values calculated from AGA8-DC92, however, deviated from the experimental data by only 0.1% at high pressures and exceeded the 0.2% limit only at temperatures of 300 K and above, for the (0.90 CH_4 + 0.10 He) mixture.

  14. Density, excess properties, electrical conductivity and viscosity of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide + γ-butyrolactone binary mixtures

    International Nuclear Information System (INIS)

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

    2014-01-01

    Highlights: • Densities of [bmim][NTf 2 ] mixtures with γ-butyrolactone were measured. • Excess properties were calculated. • Nature of interactions between IL and GBL were discussed. • Specific conductivity and viscosity were also measured. • Walden plot is presented. - Abstract: Density, electrical conductivity and viscosity of binary liquid mixtures of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [bmim][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 were fitted with Redlich–Kister polynomial equation. Other volumetric properties, such as isobaric thermal expansion coefficients, partial molar volumes, apparent 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

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

    Science.gov (United States)

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

    2016-09-01

    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 boundary condition can be applied. The measured viscous slip coefficients of binary gas mixtures exhibit a concave function of the molar ratio of the mixture, showing a similar profile with numerical results. However, from the detailed comparison between the measured and numerical values with the complete and incomplete accommodation at a surface, it is inappropriate to estimate the viscous slip coefficient for the mixture numerically by employing separately measured tangential momentum accommodation coefficient for each component. The time variation of the molar ratio in the downstream chamber was measured by sampling the gas from the chamber using the quadrupole mass spectrometer. In our measurements, it is indicated that the volume flow rate of argon is larger than that of helium because of the difference in the tangential momentum accommodation coefficient.

  16. 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.

  17. Sedimentation stacking diagram of binary colloidal mixtures and bulk phases in the plane of chemical potentials

    International Nuclear Information System (INIS)

    Heras, Daniel de las; Schmidt, Matthias

    2015-01-01

    We give a full account of a recently proposed theory that explicitly relates the bulk phase diagram of a binary colloidal mixture to its phase stacking phenomenology under gravity (de las Heras and Schmidt 2013 Soft Matter 9 8636). As we demonstrate, the full set of possible phase stacking sequences in sedimentation-diffusion equilibrium originates from straight lines (sedimentation paths) in the chemical potential representation of the bulk phase diagram. From the analysis of various standard topologies of bulk phase diagrams, we conclude that the corresponding sedimentation stacking diagrams can be very rich, even more so when finite sample height is taken into account. We apply the theory to obtain the stacking diagram of a mixture of nonadsorbing polymers and colloids. We also present a catalog of generic phase diagrams in the plane of chemical potentials in order to facilitate the practical application of our concept, which also generalizes to multi-component mixtures. (paper)

  18. Boiling temperature measurement for water, methanol, ethanol and their binary mixtures in the presence of a hydrochloric or acetic salt of mono-, di- or tri-ethanolamine at 101.3 kPa

    Energy Technology Data Exchange (ETDEWEB)

    Wang Junfeng [State Key Lab. of Chem. Resource Eng, College of Chem. Eng., Beijing Univ. of Chem. Tech. Beijing 100029 (China)], E-mail: Licx@mail.buct.edu.cn; Li Xuemei; Meng Hong [College of Chem. Eng.., Beijing Univ. of Chem. Tech. Beijing 100029 (China); Li Chunxi [State Key Lab. of Chem. Resource Eng, College of Chem. Eng., Beijing Univ. of Chem. Tech. Beijing 100029 (China); Wang Zihao [College of Chem. Eng., Beijing Univ. of Chem. Tech. Beijing 100029 (China)

    2009-02-15

    The boiling temperature at atmospheric pressure were measured for 12 binary systems within the range T = (316 to 379) K and 7 ternary systems using a dual circulation. The systems studied contained water, methanol or ethanol with the following ionic liquids (ILs): monoethanolammonium acetate ([HEMA][Ac]), diethanolammonium acetate ([HDEA][Ac]), triethanolammonium acetate ([HTEA][Ac]) and diethanolammonium chloride ([HDEA]Cl). The experimental VLE results of the IL-containing binary systems were correlated by NRTL equation, and the binary NRTL parameters were used for the prediction of VLE of ternary systems with average absolute deviation of 0.73 K in boiling temperature. The results indicate that [HDEA]Cl can be used as an efficient solvent for the extractive distillation of (ethanol + water) mixture due to its notable salting-out effect, which lower the vapour pressure of water, increase the volatility of ethanol and eliminate the azeotropic phenomenon of the (water + ethanol) mixture at definite IL concentration.

  19. Boiling temperature measurement for water, methanol, ethanol and their binary mixtures in the presence of a hydrochloric or acetic salt of mono-, di- or tri-ethanolamine at 101.3 kPa

    International Nuclear Information System (INIS)

    Wang Junfeng; Li Xuemei; Meng Hong; Li Chunxi; Wang Zihao

    2009-01-01

    The boiling temperature at atmospheric pressure were measured for 12 binary systems within the range T = (316 to 379) K and 7 ternary systems using a dual circulation. The systems studied contained water, methanol or ethanol with the following ionic liquids (ILs): monoethanolammonium acetate ([HEMA][Ac]), diethanolammonium acetate ([HDEA][Ac]), triethanolammonium acetate ([HTEA][Ac]) and diethanolammonium chloride ([HDEA]Cl). The experimental VLE results of the IL-containing binary systems were correlated by NRTL equation, and the binary NRTL parameters were used for the prediction of VLE of ternary systems with average absolute deviation of 0.73 K in boiling temperature. The results indicate that [HDEA]Cl can be used as an efficient solvent for the extractive distillation of (ethanol + water) mixture due to its notable salting-out effect, which lower the vapour pressure of water, increase the volatility of ethanol and eliminate the azeotropic phenomenon of the (water + ethanol) mixture at definite IL concentration

  20. Vapor-liquid equilibria of binary and ternary mixtures of acetaldehyde with Versatic 9 and Veova 9

    NARCIS (Netherlands)

    Raeissi, S.; Florusse, L.J.; Kroon, M.C.; Peters, C.J.

    2016-01-01

    In continuation of our earlier publication on the phase behavior of binary and ternary mixtures involving acetaldehyde, Versatic 10, and Veova 10, in this work we present bubble-point pressures of the binary and ternary systems of acetaldehyde, Versatic 9, and Veova 9. The measurements were carried

  1. 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.

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

    International Nuclear Information System (INIS)

    Liu, Chang; Fiol, Núria; Villaescusa, Isabel; Poch, Jordi

    2016-01-01

    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. The effect of vapor polarity and boiling point on breakthrough for binary mixtures on respirator carbon.

    Science.gov (United States)

    Robbins, C A; Breysse, P N

    1996-08-01

    This research evaluated the effect of the polarity of a second vapor on the adsorption of a polar and a nonpolar vapor using the Wheeler model. To examine the effect of polarity, it was also necessary to observe the effect of component boiling point. The 1% breakthrough time (1% tb), kinetic adsorption capacity (W(e)), and rate constant (kv) of the Wheeler model were determined for vapor challenges on carbon beds for both p-xylene and pyrrole (referred to as test vapors) individually, and in equimolar binary mixtures with the polar and nonpolar vapors toluene, p-fluorotoluene, o-dichlorobenzene, and p-dichlorobenzene (referred to as probe vapors). Probe vapor polarity (0 to 2.5 Debye) did not systematically alter the 1% tb, W(e), or kv of the test vapors. The 1% tb and W(e) for test vapors in binary mixtures can be estimated reasonably well, using the Wheeler model, from single-vapor data (1% tb +/- 30%, W(e) +/- 20%). The test vapor 1% tb depended mainly on total vapor concentration in both single and binary systems. W(e) was proportional to test vapor fractional molar concentration (mole fraction) in mixtures. The kv for p-xylene was significantly different (p boiling point; however, these differences were apparently of limited importance in estimating 1% tb for the range of boiling points tested (111 to 180 degrees C). Although the polarity and boiling point of chemicals in the range tested are not practically important in predicting 1% tb with the Wheeler model, an effect due to probe boiling point is suggested, and tests with chemicals of more widely ranging boiling point are warranted. Since the 1% tb, and thus, respirator service life, depends mainly on total vapor concentration, these data underscore the importance of taking into account the presence of other vapors when estimating respirator service life for a vapor in a mixture.

  4. Dynamics of glycerine and water transport across human skin from binary mixtures.

    Science.gov (United States)

    Ventura, S A; Kasting, G B

    2017-04-01

    Skin transport properties of glycerine and water from binary mixtures contacting human skin were determined to better understand the mechanism of skin moisturization by aqueous glycerine formulations. Steady-state permeation for 3 H 2 O and 14 C-glycerine across split-thickness human skin in vitro and desorption dynamics of the same permeants in isolated human stratum corneum (HSC) were experimentally determined under near equilibrium conditions. These data were compared to a priori values developed in the context of a thermodynamic model for binary mixtures of glycerine and water and a previously determined water sorption isotherm for HSC. This allowed the estimation of diffusion and partition coefficients for each permeant in the HSC, as well as HSC thickness, as a function of composition of the contacting solution. These data may be used to estimate water retention and associated HSC swelling related to the absorption and slow release of glycerine from the skin. It took 6+ days for glycerine to completely desorb from HSC immersed in glycerine/water binary solutions. Desorption of both 3 H 2 O and 14 C-glycerine from HSC was slower in pure water than from binary mixtures, a result that is largely explained by the greater swelling of HSC in water. Parametric relationships were developed for water and glycerine intradiffusivities in HSC as functions of HSC water content, and a mutual diffusion coefficient was estimated by analogy with glycerine/water binary solutions. The intradiffusivity of 14 C-glycerine in HSC as inferred from sorption/desorption experiments was shown to be approximately 10-fold less than that inferred from permeation experiments, whereas the corresponding values for 3 H 2 O were comparable. These studies confirm that glycerine enters HSC in substantial quantities and has a long residence time therein. The coupling between bulk water and glycerine transport projected from binary solution data suggests the net effect of glycerine is to slow water

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

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Gyan Prakash, E-mail: gyan.dubey@rediffmail.com [Department of Chemistry, Kurukshetra University, Kurukshetra 136119 (India); Kumar, Krishan [Department of Chemistry, Kurukshetra University, Kurukshetra 136119 (India)

    2011-09-20

    Highlights: {yields} Thermodynamic study of diethylenetriamine + 2-methyl-1-propanol, +2-propanol or +1-butanol have been made. {yields} Excess molar volumes and isentropic compressibility were determined. {yields} Types of interactions were discussed based on derived properties. - Abstract: Densities, {rho}, viscosities, {eta}, 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{sub m}{sup E} and deviations in isentropic compressibility, {Delta}{kappa}{sub s}, and speed of sound, {Delta}u have been evaluated. Viscosity data were used to compute deviations in viscosity and excess Gibbs energy of activation of viscous flow {Delta}G*{sup 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.

  6. 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.

  7. Separation and recycling of nanoparticles using cloud point extraction with non-ionic surfactant mixtures.

    Science.gov (United States)

    Nazar, Muhammad Faizan; Shah, Syed Sakhawat; Eastoe, Julian; Khan, Asad Muhammad; Shah, Afzal

    2011-11-15

    A viable cost-effective approach employing mixtures of non-ionic surfactants Triton X-114/Triton X-100 (TX-114/TX-100), and subsequent cloud point extraction (CPE), has been utilized to concentrate and recycle inorganic nanoparticles (NPs) in aqueous media. Gold Au- and palladium Pd-NPs have been pre-synthesized in aqueous phases and stabilized by sodium 2-mercaptoethanesulfonate (MES) ligands, then dispersed in aqueous non-ionic surfactant mixtures. Heating the NP-micellar systems induced cloud point phase separations, resulting in concentration of the NPs in lower phases after the transition. For the Au-NPs UV/vis absorption has been used to quantify the recovery and recycle efficiency after five repeated CPE cycles. Transmission electron microscopy (TEM) was used to investigate NP size, shape, and stability. The results showed that NPs are preserved after the recovery processes, but highlight a potential limitation, in that further particle growth can occur in the condensed phases. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Hydroxyl group as IR probe to detect the structure of ionic liquid-acetonitrile mixtures

    Science.gov (United States)

    Xu, Jing; Deng, Geng; Zhou, Yu; Ashraf, Hamad; Yu, Zhi-Wu

    2018-06-01

    Task-specific ionic liquids (ILs) are those with functional groups introduced in the cations or anions of ILs to bring about specific properties for various tasks. In this work, the hydrogen bonding interactions between a hydroxyl functionalized IL 1-(2-hydroxylethyl)-3-methylimidazolium tetrafluoroborate ([C2OHMIM][BF4]) and acetonitrile were investigated in detail by infrared spectroscopy, excess spectroscopy, two-dimensional correlation spectroscopy, combined with hydrogen nuclear magnetic resonance and density functional theory calculations (DFT). The hydroxyl group rather than C2sbnd H is found to be the main interaction site in the cation. And the ν(Osbnd H) is more sensitive than v(C-Hs) to the environment, which has been taken as an intrinsic probe to reflect the structural change of IL. Examining the region of ν(Osbnd H), by combining excess spectroscopy and DFT calculation, a number of species were identified in the mixtures. Other than the hydrogen bond between a cation and an anion, the hydroxyl group allows the formation of a hydrogen bond between two like-charged cations. The Osbnd H⋯O hydrogen bonding interactions in the hydroxyl-mediated cation-cation complexes are cooperative, while Osbnd H⋯F and C2sbnd H⋯F hydrogen bonding interactions in cation-anion complexes are anti-cooperative. These in-depth studies on the properties of the ionic liquid-acetonitrile mixtures may shed light on exploring their applications as mixed solvents and understanding the nature of doubly ionic hydrogen bonds.

  9. Thermodynamics of non-ionic surfactant Triton X-100-cationic surfactants mixtures at the cloud point

    International Nuclear Information System (INIS)

    Batigoec, Cigdem; Akbas, Halide; Boz, Mesut

    2011-01-01

    Highlights: → Non-ionic surfactants are used as emulsifier and solubilizate in such as textile, detergent and cosmetic. → Non-ionic surfactants occur phase separation at temperature as named the cloud point in solution. → Dimeric surfactants have attracted increasing attention due to their superior surface activity. → The positive values of ΔG cp 0 indicate that the process proceeds nonspontaneous. - Abstract: This study investigates the effects of gemini and conventional cationic surfactants on the cloud point (CP) of the non-ionic surfactant Triton X-100 (TX-100) in aqueous solutions. Instead of visual observation, a spectrophotometer was used for measurement of the cloud point temperatures. The thermodynamic parameters of these mixtures were calculated at different cationic surfactant concentrations. The gemini surfactants of the alkanediyl-α-ω-bis (alkyldimethylammonium) dibromide type, on the one hand, with different alkyl groups containing m carbon atoms and an ethanediyl spacer, referred to as 'm-2-m' (m = 10, 12, and 16) and, on the other hand, with -C 16 alkyl groups and different spacers containing s carbon atoms, referred to as '16-s-16' (s = 6 and 10) were synthesized, purified and characterized. Additions of the cationic surfactants to the TX-100 solution increased the cloud point temperature of the TX-100 solution. It was accepted that the solubility of non-ionic surfactant containing polyoxyethylene (POE) hydrophilic chain was a maximum at the cloud point so that the thermodynamic parameters were calculated at this temperature. The results showed that the standard Gibbs free energy (ΔG cp 0 ), the enthalpy (ΔH cp 0 ) and the entropy (ΔS cp 0 ) of the clouding phenomenon were found positive in all cases. The standard free energy (ΔG cp 0 ) increased with increasing hydrophobic alkyl chain for both gemini and conventional cationic surfactants; however, it decreased with increasing surfactant concentration.

  10. 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.

  11. Isobaric vapor-liquid equilibria for the extractive distillation of 2-propanol + water mixtures using 1-ethyl-3-methylimidazolium dicyanamide ionic liquid

    International Nuclear Information System (INIS)

    Orchillés, A. Vicent; Miguel, Pablo J.; González-Alfaro, Vicenta; Llopis, Francisco J.; Vercher, Ernesto; Martínez-Andreu, Antoni

    2017-01-01

    Highlights: • VLE of binary and ternary systems of 2-propanol, water and [emim][DCA] at 100 kPa. • The e-NRTL model fits the VLE data of 2-propanol + water + [emim][DCA] system. • [emim][DCA] breaks the 2-propanol + water azeotrope at an IL mole fraction >0.085. - Abstract: Isobaric vapor–liquid equilibria for the binary systems 2-propanol + water, 2-propanol + 1-ethyl-3-methylimidazolium dicyanamide ([emim][DCA]), and water + [emim][DCA] as well as the vapor–liquid equilibria for the 2-propanol + water + [emim][DCA] ternary system have been obtained at 100 kPa using a recirculating still. The electrolyte nonrandom two-liquid (e-NRTL) model was used for fitting successfully the experimental data. The effect of [emim][DCA] on the 2-propanol + water system has been compared with that produced by other ionic liquids reported in the literature. From the results, [emim][DCA] appears as a good entrainer for the extractive distillation of this solvent mixture, causing the azeotrope to disappear at 100 kPa when the ionic liquid mole fraction is greater than 0.085.

  12. 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.

  13. Determination of molecular diffusion coefficient in n-alkane binary mixtures: empirical correlations.

    Science.gov (United States)

    De Mezquia, D Alonso; Bou-Ali, M Mounir; Larrañaga, M; Madariaga, J A; Santamaría, C

    2012-03-08

    In this work we have measured the molecular diffusion coefficient of the n-alkane binary series nC(i)-nC(6), nC(i)-nC(10), and nC(i)-nC(12) at 298 K and 1 atm and a mass fraction of 0.5 by using the so-called sliding symmetric tubes technique. The results show that the diffusion coefficient at this concentration is proportional to the inverse viscosity of the mixture. In addition, we have also measured the diffusion coefficient of the systems nC(12)-nC(6), nC(12)-nC(7), and nC(12)-nC(8) as a function of concentration. From the data obtained, it is shown that the diffusion coefficient of the n-alkane binary mixtures at any concentration can be calculated from the molecular weight of the components and the dynamic viscosity of the corresponding mixture at 50% mass fraction.

  14. 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.

  15. Optical properties of binary and ternary liquid mixtures containing tetralin, isobutylbenzene and dodecane

    International Nuclear Information System (INIS)

    Sechenyh, Vitaliy V.; Legros, Jean-Claude; Shevtsova, Valentina

    2013-01-01

    Highlights: ► The refractive indices in binary and ternary mixtures of hydrocarbons were measured. ► The error of the theoretical prediction of the refractive indices does not exceed 0.13%. ► The error of the prediction of concentration derivatives is unsatisfactory large. ► Feasibility of application of optical methods to measuring mass transport coefficients is studied. -- Abstract: Refractive indices of binary and ternary mixtures formed by tetralin (1,2,3,4-tetrahydronaphthalene), isobutylbenzene (2-methyl-1-propyl benzene) and n-dodecane are presented over a wide range of compositions. All measurements of the refractive index have been conducted at 298.15 K and atmospheric pressure using two light sources: one in the visible (λ = 670 nm) and the other in the infrared (λ = 925 nm) spectrum. The concentration derivatives of the refractive index have been determined. The mixture compositions, where these two wavelengths are applicable for the measurements of mass transport coefficients by interferometry, are estimated and discussed

  16. 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)

  17. 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.

  18. 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.

  19. Study of decolorisation of binary dye mixture by response surface methodology.

    Science.gov (United States)

    Khamparia, Shraddha; Jaspal, Dipika

    2017-10-01

    Decolorisation of a complex mixture of two different classes of textile dyes Direct Red 81 (DR81) and Rhodamine B (RHB), simulating one of the most important condition in real textile effluent was investigated onto deoiled Argemone Mexicana seeds (A. Mexicana). The adsorption behaviour of DR81 and RHB dyes was simultaneously analyzed in the mixture using derivative spectrophotometric method. Central composite design (CCD) was employed for designing the experiments for this complex binary mixture where significance of important parameters and possible interactions were analyzed by response surface methodology (RSM). Maximum adsorption of DR81 and RHB by A. Mexicana was obtained at 53 °C after 63.33 min with 0.1 g of adsorbent and 8 × 10 -6  M DR81, 12 × 10 -6  M RHB with composite desirability of 0.99. The predicted values for percentage removal of dyes from the mixture were in good agreement with the experimental values with R 2 > 96% for both the dyes. CCD superimposed RSM confirmed that presence of different dyes in a solution created a competition for the adsorbent sites and hence interaction of dyes was one of the most important factor to be studied to simulate the real effluent. The adsorbent showed remarkable adsorption capacities for both the dyes in the mixture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. 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 ...

  1. 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.

  2. Binary and ternary gas mixtures with temperature enhanced diffuse glow discharge characteristics for use in closing switches

    Science.gov (United States)

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

    1990-06-26

    An improvement to the gas mixture used in diffuse glow discharge closing switches is disclosed which includes binary and ternary gas mixtures which are formulated to exhibit decreasing electron attachment with increasing temperature. This increases the efficiency of the conductance of the glow discharge and further inhibits the formation of an arc. 11 figs.

  3. 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.

  4. 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

  5. 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.

  6. Radiation grafting from binary monomer mixtures. II. Vinyl ether of monoethanolamine and N-vinylpyrrolidone

    International Nuclear Information System (INIS)

    Nurkeeva, Zauresh S.; Abdel Aal, A.-S.; Kupchishin, Anatoliy I.; Khutoryanskiy, Vitaliy V.; Mun, Grigoriy A.; Beksyrgaeva, Aida G.

    2003-01-01

    Radiation grafting from binary monomer mixtures of vinyl ether of monoethanolamine and N-vinylpyrrolidone onto polyethylene films has been studied. The structure of the grafted films was characterized by FTIR spectroscopy. Water uptake and contact angle measurements confirmed that the grafting leads to a considerable hydrophilization of the films surface. The presence of the more active N-vinylpyrrolidone enhances the grafting of the less active vinyl ether of monoethanolamine. Sorption properties of grafted films with respect to copper (II) ions have been studied

  7. 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)

  8. 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

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

    International Nuclear Information System (INIS)

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

    2003-01-01

    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

  10. Study of Molecular Interactions in Binary Liquid Mixtures by Acoustical Method at 303K

    Directory of Open Access Journals (Sweden)

    P. Paul Divakar

    2012-01-01

    Full Text Available Ultrasonic velocity and density measurements were made in two binary liquid mixtures Isopropyl acetate (IPA and Isobutyl acetate (IBA with cyclohexanone (CY as a common component at 303K, at fixed frequency of 2MHz using single crystal variable path interferometer and specific gravity bottle respectively. The experimental data have been used to calculate the acoustic impedance, adiabatic compressibility, inter molecular free length and molar volume. The excess thermodynamic parameters have been evaluated and discussed in the light of molecular interactions.

  11. 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.

  12. The potential energy landscape in the Lennard-Jones binary mixture model

    International Nuclear Information System (INIS)

    Sampoli, M; Benassi, P; Eramo, R; Angelani, L; Ruocco, G

    2003-01-01

    The potential energy landscape in the Kob-Andersen Lennard-Jones binary mixture model has been studied carefully from the liquid down to the supercooled regime, from T = 2 down to 0.46. One thousand independent configurations along the time evolution locus have been examined at each temperature investigated. From the starting configuration, we searched for the nearest saddle (or quasi-saddle) and minimum of the potential energy. The vibrational densities of states for the starting and the two derived configurations have been evaluated. Besides the number of negative eigenvalues of the saddles other quantities show some signature of the approach of the dynamical arrest temperature

  13. 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.

  14. 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.

  15. Three Boundary Conditions for Computing the Fixed-Point Property in Binary Mixture Data.

    Directory of Open Access Journals (Sweden)

    Leendert van Maanen

    Full Text Available The notion of "mixtures" has become pervasive in behavioral and cognitive sciences, due to the success of dual-process theories of cognition. However, providing support for such dual-process theories is not trivial, as it crucially requires properties in the data that are specific to mixture of cognitive processes. In theory, one such property could be the fixed-point property of binary mixture data, applied-for instance- to response times. In that case, the fixed-point property entails that response time distributions obtained in an experiment in which the mixture proportion is manipulated would have a common density point. In the current article, we discuss the application of the fixed-point property and identify three boundary conditions under which the fixed-point property will not be interpretable. In Boundary condition 1, a finding in support of the fixed-point will be mute because of a lack of difference between conditions. Boundary condition 2 refers to the case in which the extreme conditions are so different that a mixture may display bimodality. In this case, a mixture hypothesis is clearly supported, yet the fixed-point may not be found. In Boundary condition 3 the fixed-point may also not be present, yet a mixture might still exist but is occluded due to additional changes in behavior. Finding the fixed-property provides strong support for a dual-process account, yet the boundary conditions that we identify should be considered before making inferences about underlying psychological processes.

  16. Nickel and binary metal mixture responses in Daphnia magna: Molecular fingerprints and (sub)organismal effects

    International Nuclear Information System (INIS)

    Vandenbrouck, Tine; Soetaert, Anneleen; Ven, Karlijn van der; Blust, Ronny; Coen, Wim de

    2009-01-01

    The recent development of a custom cDNA microarray platform for one of the standard organisms in aquatic toxicology, Daphnia magna, opened up new ways to mechanistic insights of toxicological responses. In this study, the mRNA expression of several genes and (sub)organismal responses (Cellular Energy Allocation, growth) were assayed after short-term waterborne metal exposure. Microarray analysis of Ni-exposed daphnids revealed several affected functional gene classes, of which the largest ones were involved in different metabolic processes (mainly protein and chitin related processes), cuticula turnover, transport and signal transduction. Furthermore, transcription of genes involved in oxygen transport and heme metabolism (haemoglobin, δ-aminolevilunate synthase) was down-regulated. Applying a Partial Least Squares regression on nickel fingerprints and biochemical (sub)organismal parameters revealed a set of co-varying genes (haemoglobin, RNA terminal phosphate cyclase, a ribosomal protein and an 'unknown' gene fragment). An inverse relationship was seen between the mRNA expression levels of different cuticula proteins and available energy reserves. In addition to the nickel exposure, daphnids were exposed to binary mixtures of nickel and cadmium or nickel and lead. Using multivariate analysis techniques, the mixture mRNA expression fingerprints (Ni 2+ + Cd 2+ , Ni 2+ + Pb 2+ ) were compared to those of the single metal treatments (Ni 2+ , Cd 2+ , Pb 2+ ). It was hypothesized that the molecular fingerprints of the mixtures would be additive combinations of the gene transcription profiles of the individual compounds present in the mixture. However, our results clearly showed additionally affected pathways after mixture treatment (e.g. additional affected genes involved in carbohydrate catabolic processes and proteolysis), indicating interactive molecular responses which are not merely the additive sum of the individual metals. These findings, although indicative of

  17. Recoil implantation reactions in binary mixtures of catcher complexes and in mixed ligand catchers

    International Nuclear Information System (INIS)

    Sekine, Tsutomu; Sano, Masaaki; Yoshihara, Kenji

    1989-01-01

    Recoil implantation reactions were studied in binary mixtures of catcher complexes of tris(β-diketonato)metal(III) and in single-component catcher complexes of Cr(acac) n (dbm) 3-n where n=1 and 2. For the mixtures of M(acac) 3 and M(dbm) 3 , the products of 51 Cr(acac) 3 and 51 Cr(dbm) 3 were obtained as major components while 51 Cr(acac) 2 (dbm) and 51 Cr(acac)(dbm) 2 were seen as minor components. For the single component catcher complexes, predominant chemical species were parent retention type compounds. In addition to retentions there were product distributions which indicated a strong preference for acac pickup. The results were interpreted by a model which involves displacement reaction as a main process and ligand pickup reactions as side processes. (orig.)

  18. 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.

  19. Physicochemical analysis and nonisothermal kinetic study of sertraline–lactose binary mixtures

    Directory of Open Access Journals (Sweden)

    Faranak Ghaderi

    2017-07-01

    Full Text Available 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.

  20. 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

  1. 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.

  2. Adsorption behavior of strontium on binary mineral mixtures of Montmorillonite and Kaolinite

    Energy Technology Data Exchange (ETDEWEB)

    Bascetin, Elvan [Cekmece Nuclear Research and Training Center, P.K.1 34149, Atatuerk Airport, Istanbul (Turkey); Atun, Guelten [Engineering Faculty, Chemistry Department, Istanbul University, 34850 Avcilar, Istanbul (Turkey)]. E-mail: gultena@istanbul.edu.tr

    2006-08-15

    The adsorption behavior of kaolinite and montmorillonite minerals and their mixtures in respect of Sr ion were studied by means of a batch method using {sup 90}Sr as a radio tracer. The effect of several parameters such as temperature, pH, Sr concentration and supporting electrolyte were investigated. Experimentally measured distribution coefficients showed a good agreement to within 98.5-99.7% with theoretically calculated values. The values of adsorption capacity of adsorbents and mean adsorption energy of adsorption were calculated by fitting the adsorption data to Dubinin-Radushkevich isotherm. The adsorption capacity of clay mixtures decreased as kaolinite fractions increased. The mean adsorption energy values of 8.0-9.5 kJ mol{sup -1} showed that adsorption was governed by ion exchange. The Freundlich parameters were used to characterize a site distribution function for binary exchange between Sr and Na.

  3. Adsorption behavior of strontium on binary mineral mixtures of Montmorillonite and Kaolinite

    International Nuclear Information System (INIS)

    Bascetin, Elvan; Atun, Guelten

    2006-01-01

    The adsorption behavior of kaolinite and montmorillonite minerals and their mixtures in respect of Sr ion were studied by means of a batch method using 90 Sr as a radio tracer. The effect of several parameters such as temperature, pH, Sr concentration and supporting electrolyte were investigated. Experimentally measured distribution coefficients showed a good agreement to within 98.5-99.7% with theoretically calculated values. The values of adsorption capacity of adsorbents and mean adsorption energy of adsorption were calculated by fitting the adsorption data to Dubinin-Radushkevich isotherm. The adsorption capacity of clay mixtures decreased as kaolinite fractions increased. The mean adsorption energy values of 8.0-9.5 kJ mol -1 showed that adsorption was governed by ion exchange. The Freundlich parameters were used to characterize a site distribution function for binary exchange between Sr and Na

  4. Thermophysical properties of energetic ionic liquids/nitric acid mixtures: insights from molecular dynamics simulations.

    Science.gov (United States)

    Hooper, Justin B; Smith, Grant D; Bedrov, Dmitry

    2013-09-14

    Molecular dynamics (MD) simulations of mixtures of the room temperature ionic liquids (ILs) 1-butyl-4-methyl imidazolium [BMIM]/dicyanoamide [DCA] and [BMIM][NO3(-)] with HNO3 have been performed utilizing the polarizable, quantum chemistry based APPLE&P(®) potential. Experimentally it has been observed that [BMIM][DCA] exhibits hypergolic behavior when mixed with HNO3 while [BMIM][NO3(-)] does not. The structural, thermodynamic, and transport properties of the IL/HNO3 mixtures have been determined from equilibrium MD simulations over the entire composition range (pure IL to pure HNO3) based on bulk simulations. Additional (non-equilibrium) simulations of the composition profile for IL/HNO3 interfaces as a function of time have been utilized to estimate the composition dependent mutual diffusion coefficients for the mixtures. The latter have been employed in continuum-level simulations in order to examine the nature (composition and width) of the IL/HNO3 interfaces on the millisecond time scale.

  5. Heat and mass transfer prediction of binary refrigerant mixtures condensing in a horizontal microfin tube

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, Shigeru; Yu, Jian; Ishibashi, Akira

    1999-07-01

    In the face of the phase-out of HCFC22 for its effect on globe environment, the alternative refrigerant has been paid attention in the refrigeration and heat pump industry. In the present stage, it is found that any pure refrigerant is not a good substitute of HCFC22 for the system in use. The authors have to use binary or ternary refrigerant mixtures as the substitute to meet industrial requirement. But until now, although the heat transfer characteristics of the refrigerant mixtures can be measured in experiments and predicted in some degree, the mass transfer characteristics in condensation process, which is a main part in most systems, can not be clarified by both experimental and theoretical methods. In the present study a non-equilibrium model for condensation of binary refrigerant mixtures inside a horizontal microfin tube is proposed. In this model it is assumed that the phase equilibrium is only established at the vapor-liquid interface, while the bulk vapor and the bulk liquid are in non-equilibrium in the same cross section. The mass transfer characteristic in vapor core is obtained from the analogy between mass and momentum transfer. In the liquid layer, the mass fraction distribution is neglected, but the mass transfer coefficient is treated as infinite that can keep a finite value for the mass transfer rate in liquid phase. From the calculation results compared with the experimental ones for the condensation of HFC134a/HCFC123 and HCFC22/CFC114 mixtures, it is found that the calculated heat flux distribution along the tube axis is in good agreement with that of experiment, and the calculated values of condensing length agree well with the experimental ones. Using the present model, the local mass faction distribution, the diffusion mass transfer rate and the mass transfer characteristics in both vapor and liquid phase are demonstrated. From these results, the effect of mass transfer resistance on condensation heat transfer characteristics for binary

  6. 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

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

    International Nuclear Information System (INIS)

    Martínez-Ruiz, F. J.; Blas, F. J.; Moreno-Ventas Bravo, A. I.

    2015-01-01

    We determine the interfacial properties of a symmetrical binary mixture of equal-sized spherical Lennard-Jones molecules, σ 11 = σ 22 , with the same dispersive energy between like species, ϵ 11 = ϵ 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 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 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 with a desorption of the

  8. 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.

    2014-01-01

    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.

  9. 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.

  10. 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.

  11. 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. 

  12. 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.

  13. Dynamic depletion attraction between colloids suspended in a phase-separating binary liquid mixture

    International Nuclear Information System (INIS)

    Araki, Takeaki; Tanaka, Hajime

    2008-01-01

    Understanding interactions between colloids (or nanoparticles) immersed in a phase-separating binary mixture is of both fundamental and technological importance. Here we report a novel type of interparticle attractive interaction of a purely dynamic origin, which is found by a coarse-grained numerical simulation. Due to surface wetting effects, there are strong diffusion fluxes towards particles just after the initiation of phase separation of the matrix binary liquid mixture. The flux in the region between particles soon becomes weaker than that in the other regions since the depletion zones formed around particles overlap selectively between the particles. The resulting imbalance of the diffusion flux induces interparticle attractive interactions, i.e., the osmotic force pushes particles closer. We confirm that this wetting-induced 'dynamic' depletion force can be stronger than a van der Waals force and a capillary force that is induced by the interfacial tension, and thus plays a dominant role in the early stage of particle aggregation. We note that this novel interaction originating from the momentum conservation law may be generic to particles acting as diffusional sinks or sources. (fast track communication)

  14. Volumetric and sound speed study of ammonium-based ionic liquid mixtures with ethanol

    International Nuclear Information System (INIS)

    Santos, Ângela F.S.; Moita, Maria-Luísa C.J.; Silva, João F.C.C.; Lampreia, Isabel M.S.

    2017-01-01

    Highlights: • Densities and sound speeds were measured at five temperatures in three ammonium-based ionic liquids mixtures with ethanol. • Excess molar and limiting molar and partial molar properties were derived and interpreted. • Specific interactions and packing effects were compared in the three systems. • Reduced variables were used to highlight differences in cation size and solvophilic effects. - Abstract: Thermodynamic studies embracing molecular interactions between ionic liquids (ILs) and molecular solvents are scarce and are required to explore molecular interactions and structural effects with interest in engineering applications. Ammonium-based are interesting ILs since they can be tailored to provide information concerning both chain length and solvophobic/solvophilic effects. In this work from accurately measured density and sound speed data in the systems ethanol + {[N 4111 ]; [N 4441 ] or [choline]}[NTf 2 ] derived quantities such as excess partial molar volumes and isentropic compressions including their limiting values were obtained. The reasoning of the results permitted to conclude that while in the [N 4441 ][NTf 2 ] case packing effects due to the difference in size of the components prevail, in the other two cases specific interaction ethanol–cation explains both the lower minimums in the excess properties and the higher magnitude of the negative limiting excess partial molar, volumes and isentropic compression values in the mixture containing [N 4111 ][NTf 2 ] in relation to [N 4441 ][NTf 2 ] and the negative limiting partial molar isentropic compression in the [choline][NTf 2 ] case in contrast with positive values for the other two ILs.

  15. 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.

  16. Improvement of supercritical CO2 Brayton cycle using binary gas mixture

    International Nuclear Information System (INIS)

    Jeong, Woo Seok

    2011-02-01

    simple recuperated layout and recompression layout Brayton cycles. For verification, existing design values of GTHTR 300, based on helium Brayton cycle, were used. Main input parameters were referred to Dostal's work as a reference cycle. The cycle performance evaluations were conducted for CO 2 -He, CO 2 -Ar, CO 2 -N 2 and CO 2 -O 2 binary mixtures by the developed cycle code. CO 2 -Xe mixture cycle was excluded in the pre-analysis since there is no mixture data. The mixed ratio of adding component was adjusted to specify the same critical temperature to be unbiased. The difference of binary gas mixture cycles compared to S-CO 2 cycle was decrease in minimum cycle temperature and changes in minimum pressure and working fluids. Through the simulation, the CO 2 -He binary mixture was found out to be the highest increase of cycle efficiency: 1.73 % when the critical temperature was at 292 K for recompression cycle layout. Unlike the CO 2 -He binary mixture, the cycle efficiencies of CO 2 -Ar, CO 2 -N 2 , and CO 2 -O 2 binary mixtures decreased compared to the pure S-CO 2 cycle: -0.71 %, -1.35 % and -1.16 %, respectively. It was found that the increment of critical pressure led to a decrease in cycle operating pressure ratio which resulted in a negative effect on total cycle efficiency. The validation for the simulation was conducted by measuring the critical point of CO 2 -He mixture. The result clearly showed that the both critical temperature and critical pressure increase while the amount of added helium increases. The prediction of the property program indicates the opposite result and it means that the simulated CO 2 -He cycle is not a supercritical Brayton cycle. For the option of CO 2 -Xe mixture, the properties can be calculated based on ideal mixing rule and also can be modified with experimental data. With the proposed method, the efficiency of CO 2 -Xe mixture cycle is expected to increase by 1.28 %

  17. Toxicity of binary mixtures of metals and pyrethroid insecticides to Daphnia magna Straus. Implications for multi-substance risks assessment

    Energy Technology Data Exchange (ETDEWEB)

    Barata, Carlos [Laboratory of Environmental Toxicology, Universitat Poltiecnica de Catalunya, CN 150 Km 14.5, Terrassa 08220 (Spain)]. E-mail: barata@intexter.upc.edu; Baird, D.J. [National Water Research Institute (Environment Canada) at Canadian Rivers Institute, 10 Bailey Drive, PO Box 45111, University of New Brunswick, Fredericton E3B 6E1, New Brunswick (Canada); Nogueira, A.J.A. [Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Soares, A.M.V.M. [Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Riva, M.C. [Laboratory of Environmental Toxicology, Universitat Poltiecnica de Catalunya, CN 150 Km 14.5, Terrassa 08220 (Spain)

    2006-06-10

    Two different concepts, termed concentration addition (CA) and independent action (IA), describe general relationships between the effects of single substances and their corresponding mixtures allowing calculation of an expected mixture toxicity on the basis of known toxicities of the mixture components. Both concepts are limited to cases in which all substances in a mixture influence the same experimental endpoint, and are usually tested against a 'fixed ratio design' where the mixture ratio is kept constant throughout the studies and the overall concentration of the mixture is systematically varied. With this design, interaction among toxic components across different mixture ratios and endpoints (i.e. lethal versus sublethal) is not assessed. In this study lethal and sublethal (feeding) responses of Daphnia magna individuals to single and binary combinations of similarly and dissimilarly acting chemicals including the metals (cadmium, copper) and the pyrethroid insecticides ({lambda}-cyhalothrin and deltamethrin) were assayed using a composite experimental design to test for interactions among toxic components across mixture effect levels, mixture ratios, lethal and sublethal toxic effects. To account for inter-experiment response variability, in each binary mixture toxicity assay the toxicity of the individual mixture constituents was also assessed. Model adequacy was then evaluated comparing the slopes and elevations of predicted versus observed mixture toxicity curves with those estimated for the individual components. Model predictive abilities changed across endpoints. The IA concept was able to predict accurately mixture toxicities of dissimilarly acting chemicals for lethal responses, whereas the CA concept did so in three out of four pairings for feeding response, irrespective of the chemical mode of action. Interaction effects across mixture effect levels, evidenced by crossing slopes, were only observed for the binary mixture Cd and Cu for

  18. Toxicity of binary mixtures of metals and pyrethroid insecticides to Daphnia magna Straus. Implications for multi-substance risks assessment

    International Nuclear Information System (INIS)

    Barata, Carlos; Baird, D.J.; Nogueira, A.J.A.; Soares, A.M.V.M.; Riva, M.C.

    2006-01-01

    Two different concepts, termed concentration addition (CA) and independent action (IA), describe general relationships between the effects of single substances and their corresponding mixtures allowing calculation of an expected mixture toxicity on the basis of known toxicities of the mixture components. Both concepts are limited to cases in which all substances in a mixture influence the same experimental endpoint, and are usually tested against a 'fixed ratio design' where the mixture ratio is kept constant throughout the studies and the overall concentration of the mixture is systematically varied. With this design, interaction among toxic components across different mixture ratios and endpoints (i.e. lethal versus sublethal) is not assessed. In this study lethal and sublethal (feeding) responses of Daphnia magna individuals to single and binary combinations of similarly and dissimilarly acting chemicals including the metals (cadmium, copper) and the pyrethroid insecticides (λ-cyhalothrin and deltamethrin) were assayed using a composite experimental design to test for interactions among toxic components across mixture effect levels, mixture ratios, lethal and sublethal toxic effects. To account for inter-experiment response variability, in each binary mixture toxicity assay the toxicity of the individual mixture constituents was also assessed. Model adequacy was then evaluated comparing the slopes and elevations of predicted versus observed mixture toxicity curves with those estimated for the individual components. Model predictive abilities changed across endpoints. The IA concept was able to predict accurately mixture toxicities of dissimilarly acting chemicals for lethal responses, whereas the CA concept did so in three out of four pairings for feeding response, irrespective of the chemical mode of action. Interaction effects across mixture effect levels, evidenced by crossing slopes, were only observed for the binary mixture Cd and Cu for lethal effects

  19. Ionic pairing in binary liquids of charged hard spheres with non-additive diameters

    International Nuclear Information System (INIS)

    Pastore, G.; Giaquinta, P.V.; Thakur, J.S.; Tosi, M.P.

    1985-07-01

    We examine types of short range order that arise in binary liquids from a combination of Coulombic interactions and non-additivity of excluded volumes, the initial motivation being observations of complex formation by hydrated ions in concentrated aqueous solutions. The model is a fluid of charged hard spheres with contact distances σsub(+-)not=1/2(σsub(++)+σsub(--)), its structural functions being evaluated in the mean spherical approximation and in the hypernetted chain approximation. Cation-anion pairing is clearly seen in the calculated structural functions for negative deviations from additivity (σsub(+-) σsub(++)=σsub(--)) favour long-wavelength concentration fluctuations and demixing in a neutral mixture: these are suppressed by Coulombic interactions in favour of microscopic intermixing of the two species in the local liquid structure, up to like-ion pairing. Contact is made with diffraction from concentrated aqueous solutions of cadmium sulphate and other instances of possible applicability of the model are pointed out. (author)

  20. CONSOLIDATION AND COMPACTION OF POWDER MIXTURES .2. BINARY-MIXTURES OF DIFFERENT PARTICLE-SIZE FRACTIONS OF ALPHA-LACTOSE MONOHYDRATE

    NARCIS (Netherlands)

    RIEPMA, KA; VEENSTRA, J; DEBOER, AH; BOLHUIS, GK; ZUURMAN, K; LERK, CF; VROMANS, H

    1991-01-01

    Binary mixtures of different particle size fractions of alpha-lactose monohydrate were compacted into tablets. The results showed decreased crushing strengths and decreased internal specific surface areas of the tablets as compared with the values calculated by linear interpolation of the data

  1. 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

  2. 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

  3. The wetting of planar solid surfaces by symmetric binary mixtures near bulk gas-liquid coexistence

    International Nuclear Information System (INIS)

    Woywod, Dirk; Schoen, Martin

    2004-01-01

    We investigate the wetting of planar, nonselective solid substrates by symmetric binary mixtures where the attraction strength between like molecules of components A and B is the same, that is ε AA ε BB AB vertical bar ≤ vertical bar ε AA vertical bar, that is by varying the attraction between a pair of unlike molecules. By means of mean-field lattice density functional calculations we observe a rich wetting behaviour as a result of the interplay between ε AB and the attraction of fluid molecules by the solid substrate ε W . In accord with previous studies we observe complete wetting only above the critical end point if the bulk mixture exhibits a moderate to weak tendency to liquid-liquid phase separation even for relatively strong fluid-substrate attraction. However, in this case layering transitions may arise below the temperature of the critical end point. For strongly phase separating mixtures complete wetting is observed for all temperatures T ≥0 along the line of discontinuous phase transitions in the bulk

  4. 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.

  5. 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.)

  6. 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.

  7. Solid-Liquid Equilibria for the Binary Mixtures 1,4-Xylene + Ethylbenzene and 1,4-Xylene + Toluene

    DEFF Research Database (Denmark)

    Huyghe, Raphaël; Rasmussen, Peter; Thomsen, Kaj

    2004-01-01

    Solid-liquid equilibrium (SLE) data for the binary mixtures 1,4-xylene + ethylbenzene, and 1,4-xylene + toluene have been measured using differential scanning calorimetry (DSC) in the temperature range from 133.15 K to 293.15 K.......Solid-liquid equilibrium (SLE) data for the binary mixtures 1,4-xylene + ethylbenzene, and 1,4-xylene + toluene have been measured using differential scanning calorimetry (DSC) in the temperature range from 133.15 K to 293.15 K....

  8. 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.

  9. Excess Volumes and Excess Isentropic Compressibilities of Binary Liquid Mixtures of Trichloroethylene with Esters at 303.15 K

    Science.gov (United States)

    Ramanaiah, S.; Rao, C. Narasimha; Nagaraja, P.; Venkateswarlu, P.

    2015-11-01

    Exces volumes, VE, and excess isentropic compressibilities, κSE, have been reported as a function of composition for binary liquid mixtures of trichloroethylene with ethyl acetate, n-propyl acetate, and n-butyl acetate at 303.15 K. Isentropic compressibilities are calculated using measured sound speeds and density data for pure components and for binary mixtures. Excess volumes and excess isentropic compressibilities are found to be negative for the three systems studied over the entire composition range at 303.15 K, whereas these values become more negative with an increase of carbon chain length. The results are discussed in terms of intermolecular interactions between unlike molecules.

  10. Thermodiffusion, molecular diffusion and Soret coefficient of binary and ternary mixtures of n-hexane, n-dodecane and toluene.

    Science.gov (United States)

    Alonso de Mezquia, David; Wang, Zilin; Lapeira, Estela; Klein, Michael; Wiegand, Simone; Mounir Bou-Ali, M

    2014-11-01

    In this study, the thermodiffusion, molecular diffusion, and Soret coefficients of 12 binary mixtures composed of toluene, n-hexane and n-dodecane in the whole range of concentrations at atmospheric pressure and temperatures of 298.15 K and 308.15 K have been determined. The experimental measurements have been carried out using the Thermogravitational Column, the Sliding Symmetric Tubes and the Thermal Diffusion Forced Rayleigh Scattering techniques. The results obtained using the different techniques show a maximum deviation of 9% for the thermodiffusion coefficient, 8% for the molecular diffusion coefficient and 2% for the Soret coefficient. For the first time we report a decrease of the thermodiffusion coefficient with increasing ratio of the thermal expansion coefficient and viscosity for a binary mixture of an organic ring compound with a short n-alkane. This observation is discussed in terms of interactions between the different components. Additionally, the thermogravitational technique has been used to measure the thermodiffusion coefficients of four ternary mixtures consisting of toluene, n-hexane and n-dodecane at 298.15 K. In order to complete the study, the values obtained for the molecular diffusion coefficient in binary mixtures, and the thermodiffusion coefficient of binary and ternary mixtures have been compared with recently derived correlations.

  11. 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.

  12. Binary Mixture of Perfect Fluid and Dark Energy in Modified Theory of Gravity

    Science.gov (United States)

    Shaikh, A. Y.

    2016-07-01

    A self consistent system of Plane Symmetric gravitational field and a binary mixture of perfect fluid and dark energy in a modified theory of gravity are considered. The gravitational field plays crucial role in the formation of soliton-like solutions, i.e., solutions with limited total energy, spin, and charge. The perfect fluid is taken to be the one obeying the usual equation of state, i.e., p = γρ with γ∈ [0, 1] whereas, the dark energy is considered to be either the quintessence like equation of state or Chaplygin gas. The exact solutions to the corresponding field equations are obtained for power-law and exponential volumetric expansion. The geometrical and physical parameters for both the models are studied.

  13. The Monte Carlo dynamics of a binary Lennard-Jones glass-forming mixture

    International Nuclear Information System (INIS)

    Berthier, L; Kob, W

    2007-01-01

    We use a standard Monte Carlo algorithm to study the slow dynamics of a binary Lennard-Jones glass-forming mixture at low temperature. We find that the Monte Carlo approach is by far the most efficient way to simulate a stochastic dynamics since the relaxation is about 10 times faster than in Brownian dynamics and about 30 times faster than in stochastic dynamics. Moreover, the average dynamical behaviour of the system is in quantitative agreement with that obtained using Newtonian dynamics, apart from at very short times where thermal vibrations are suppressed. We show, however, that dynamic fluctuations quantified by four-point dynamic susceptibilities do retain a dependence on the microscopic dynamics, as recently predicted theoretically

  14. The effect of atom mismatch on the fragility of supercooled Lennard-Jones binary mixtures

    International Nuclear Information System (INIS)

    Sun Minhua; Sun Yongli; Wang Aiping; Ma Congxiao; Li Jiayun; Cheng Weidong; Liu Fang

    2006-01-01

    The shear viscosity of the well-known binary Lennard-Jones mixture is simulated under constant temperature and constant volume conditions (NVT) by a molecular-dynamics (MD) method. The effect of atomic size mismatch on the fragility parameter and glass-forming ability is studied. The fragility parameters calculated from shear viscosity data decrease with the increment of the atomic size mismatch. The value of the fragility changes from 168.963 to 22.976 when the mismatch changes from 0.023 to 0.25. It is shown that the fragility parameter is sensitive to the atomic size mismatch. The calculated pair distribution functions and mean square displacements indicate that the glass-forming ability increases with the atomic size mismatch

  15. 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.)

  16. 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.

  17. Simultaneous determination of a binary mixture: kinetic method for determination of uranium and vanadium

    International Nuclear Information System (INIS)

    Jianhua, W.; Ronghuan, H.

    1993-01-01

    A kinetic method for simultaneous determination of a binary mixture is proposed, and a procedure for simultaneous determination of uranium (IV) and vanadium (IV) is established based on their inductive effect on chromium (VI)-iodide redox reaction in a weak acidic medium. The reaction was monitored by FIA-spectrophotometry using the I 3 - -starch complex as indicator. The calibration graphs are linear for uranium (IV) and vanadium (IV) within the range of 0 ∼ 3.6 μg/ml and 0 ∼ 2.5 μg/ml respectively. Most foreign ions, except for iron (II) and antimony (III), do not interfere with the determination. The uranium and vanadium content in different samples was determined, and the results were satisfactory. (author). 2 tabs., 2 figs., 9 refs

  18. 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.

  19. Structure formation in binary mixtures of lipids and detergents: self-assembly and vesicle division.

    Science.gov (United States)

    Noguchi, Hiroshi

    2013-01-14

    Self-assembly dynamics in binary surfactant mixtures and structure changes of lipid vesicles induced by detergent solution are studied using coarse-grained molecular simulations. Disk-shaped micelles, the bicelles, are stabilized by detergents surrounding the rim of a bilayer disk of lipids. The self-assembled bicelles are considerably smaller than bicelles formed from vesicle rupture, and their size is determined by the concentrations of lipids and detergents and the interactions between the two species. The detergent-adsorption induces spontaneous curvature of the vesicle bilayer and results in vesicle division into two vesicles or vesicle rupture into worm-like micelles. The division occurs mainly via the inverse pathway of the modified stalk model. For large spontaneous curvature of the monolayers of the detergents, a pore is often opened, thereby leading to vesicle division or worm-like micelle formation.

  20. 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)

  1. 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.

  2. 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.

  3. Diffusion-stress coupling in liquid phase during rapid solidification of binary mixtures

    International Nuclear Information System (INIS)

    Sobolev, S.L.

    2014-01-01

    An analytical model has been developed to describe the diffusion-viscous stress coupling in the liquid phase during rapid solidification of binary mixtures. The model starts with a set of evolution equations for diffusion flux and viscous pressure tensor, based on extended irreversible thermodynamics. It has been demonstrated that the diffusion-stress coupling leads to non-Fickian diffusion effects in the liquid phase. With only diffusive dynamics, the model results in the nonlocal diffusion equations of parabolic type, which imply the transition to complete solute trapping only asymptotically at an infinite interface velocity. With the wavelike dynamics, the model leads to the nonlocal diffusion equations of hyperbolic type and describes the transition to complete solute trapping and diffusionless solidification at a finite interface velocity in accordance with experimental data and molecular dynamic simulation. -- Highlights: •We propose the diffusion-stress coupling model for binary solidification. •The coupling arises at deep undercooling. •With diffusive dynamics, the models result in parabolic transfer equations. •With the wavelike dynamics, the models lead to hyperbolic transfer equations. •The coupling strongly affects the solute partition coefficient

  4. Pharmacokinetic and pharmacodynamic interaction for a binary mixture of chlorpyrifos and diazinon in the rat

    International Nuclear Information System (INIS)

    Timchalk, C.; Poet, T.S.; Hinman, M.N.; Busby, A.L.; Kousba, A.A.

    2005-01-01

    Chlorpyrifos (CPF) and diazinon (DZN) are two commonly used organophosphorus (OP) insecticides and a potential exists for concurrent exposures. The primary neurotoxic effects from OP pesticide exposures result from the inhibition of acetylcholinesterase (AChE). The pharmacokinetic and pharmacodynamic impact of acute binary exposures of rats to CPF and DZN was evaluated in this study. Rats were orally administered CPF, DZN, or a CPF/DZN mixture (0, 15, 30, or 60 mg/kg) and blood (plasma and RBC), and brain were collected at 0, 3, 6, 12, and 24 h postdosing, urine was also collected at 24 h. Chlorpyrifos, DZN, and their respective metabolites, 3,5,6-trichloro-2-pyridinol (TCP) and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMHP), were quantified in blood and/or urine and cholinesterase (ChE) inhibition was measured in brain, RBC, and plasma. Coexposure to CPF/DZN at the low dose of 15/15 mg/kg did not alter the pharmacokinetics of CPF, DZN, or their metabolites in blood. A high binary dose of 60/60 mg/kg increased the C max and AUC and decreased the clearance for both parent compounds, likely due to competition between CPF and DZN for CYP450 metabolism. At lower doses, most likely to be encountered in occupational or environmental exposures, the pharmacokinetics were linear. A dose-dependent inhibition of ChE was noted in tissues for both the single and coexposures, and the extent of inhibition was plasma > RBC ≥ brain. The overall relative potency for ChE inhibition was CPF/DZN > CPF > DZN. A comparison of the ChE response at the low binary dose (15/15 mg/kg), where there were no apparent pharmacokinetic interactions, suggested that the overall ChE response was additive. These experiments represent important data concerning the potential pharmacokinetic and pharmacodynamic interactions for pesticide mixtures and will provide needed insight for assessing the potential cumulative risk associated with occupational or environmental exposures to these insecticides

  5. 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.

  6. 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.

  7. 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

  8. 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)

  9. 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.

  10. The structure of n-alkane binary mixtures adsorbed on graphite

    International Nuclear Information System (INIS)

    Espeau, Philippe; White, John W.; Papoular, Robert J.

    2005-01-01

    The thermodynamics and structure of the surface adsorbed phase in binary C15-C16 and C15-C17 n-alkane mixtures confined in graphite pores have been studied by differential scanning calorimetry and small-angle X-ray scattering. The previously observed selective adsorption of the longer alkane for chain length differences greater than five carbon atoms is verified but reduced for chain length differences less than or equal to two. With a difference in chain length of one carbon atom, Vegard's law is followed for the melting points of the adsorbed mixture and the (0 2) d-spacing is a continuous function of the mole fraction x. With a two-carbon atom difference, samples aged for 1 week have a lamellar structure for which the entities A 1-x B x try to be commensurate with the substrate. The same samples aged for 1 month show a continuous parabolic x-dependence for both the melting points and the d-spacings. An explanation in terms of selective probability of adsorption is proposed based on crystallographic considerations

  11. The structure of n-alkane binary mixtures adsorbed on graphite

    Energy Technology Data Exchange (ETDEWEB)

    Espeau, Philippe [Laboratoire de Chimie Physique et Minerale, Faculte de Pharmacie, Universite Rene Descartes-Paris V, F-75006 Paris (France)]. E-mail: philippe.espeau@univ-paris5.fr; White, John W. [Research School of Chemistry, Australian National University, Canberra, ACT 0200 (Australia); Papoular, Robert J. [Laboratoire Leon Brillouin, CEA-CEN Saclay, F-91191 Gif-sur-Yvette Cedex (France)

    2005-12-15

    The thermodynamics and structure of the surface adsorbed phase in binary C15-C16 and C15-C17 n-alkane mixtures confined in graphite pores have been studied by differential scanning calorimetry and small-angle X-ray scattering. The previously observed selective adsorption of the longer alkane for chain length differences greater than five carbon atoms is verified but reduced for chain length differences less than or equal to two. With a difference in chain length of one carbon atom, Vegard's law is followed for the melting points of the adsorbed mixture and the (0 2) d-spacing is a continuous function of the mole fraction x. With a two-carbon atom difference, samples aged for 1 week have a lamellar structure for which the entities A{sub 1-x}B {sub x} try to be commensurate with the substrate. The same samples aged for 1 month show a continuous parabolic x-dependence for both the melting points and the d-spacings. An explanation in terms of selective probability of adsorption is proposed based on crystallographic considerations.

  12. Pattern selection near the onset of convection in binary mixtures in cylindrical cells

    International Nuclear Information System (INIS)

    Alonso, Arantxa; Mercader, Isabel; Batiste, Oriol

    2014-01-01

    We report numerical investigations of three-dimensional pattern formation of binary mixtures in a vertical cylindrical container heated from below. Negative separation ratio mixtures, for which the onset of convection occurs via a subcritical Hopf bifurcation, are considered. We focus on the dynamics in the neighbourhood of the initial oscillatory instability and analyze the spatio-temporal properties of the patterns for different values of the aspect ratio of the cell, 0.25≲Γ≲11 (Γ≡R/d, where R is the radius of the cell and d its height). Despite the oscillatory nature of the primary instability, for highly constrained geometries, Γ≲2.5, only pure thermal stationary modes are selected after long transients. As the aspect ratio of the cell increases, for intermediate aspect ratio cells such as Γ=3, multistability and coexistence of stationary and time-dependent patterns is observed. In highly extended cylinders, Γ≈11, the dynamics near the onset is completely different from the pure fluid case, and a startling diversity of confined patterns is observed. Many of these patterns are consistent with experimental observations. Remarkably, though, we have obtained persistent large amplitude highly localized states not reported previously. (paper)

  13. Pattern selection near the onset of convection in binary mixtures in cylindrical cells

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Arantxa; Mercader, Isabel; Batiste, Oriol, E-mail: arantxa@fa.upc.edu [Departament de Física Aplicada, Universitat Politècnica de Catalunya, Mòdul B4, 08034 Barcelona (Spain)

    2014-08-01

    We report numerical investigations of three-dimensional pattern formation of binary mixtures in a vertical cylindrical container heated from below. Negative separation ratio mixtures, for which the onset of convection occurs via a subcritical Hopf bifurcation, are considered. We focus on the dynamics in the neighbourhood of the initial oscillatory instability and analyze the spatio-temporal properties of the patterns for different values of the aspect ratio of the cell, 0.25≲Γ≲11 (Γ≡R/d, where R is the radius of the cell and d its height). Despite the oscillatory nature of the primary instability, for highly constrained geometries, Γ≲2.5, only pure thermal stationary modes are selected after long transients. As the aspect ratio of the cell increases, for intermediate aspect ratio cells such as Γ=3, multistability and coexistence of stationary and time-dependent patterns is observed. In highly extended cylinders, Γ≈11, the dynamics near the onset is completely different from the pure fluid case, and a startling diversity of confined patterns is observed. Many of these patterns are consistent with experimental observations. Remarkably, though, we have obtained persistent large amplitude highly localized states not reported previously. (paper)

  14. Liquid--vapor isotope fractionation factors in argon--krypton binary mixtures

    International Nuclear Information System (INIS)

    Lee, M.W.; Neufeld, P.; Bigeleisen, J.

    1977-01-01

    An equilibrium isotope effect has been studied as a continuous function of the potential field acting on the atom undergoing isotopic exchange. This has been accomplished through a study of the liquid vapor isotope fractionation factors for both, 36 Ar/ 40 Ar and 80 Kr/ 84 Kr in a series of binary mixtures which span the range between the pure components at 117.5 0 K. The 36 Ar/ 40 Ar fractionation factor increases (linearly) from (lnα)2.49 x 10 -3 in pure liquid argon to 2.91 x 10 -3 in an infinitely dilute solution in liquid krypton. Conversely, the 80 Kr/ 84 Kr fractionation factor decreases (linearly) from (lnα)0.98 x 10 -3 in pure liquid krypton to 0.64 x 10 -3 in an infinetely dilute solution in pure liquid argon. The mean force constants 2 U>/sub c/ on both argon and krypton atoms in the mixtures are derived from the respective isotope fractionation factors.The mean force constants for argon and krypton as a function of composition have been calculated by a modified corresponding states theory which uses the pure liquids as input parameters. The discrepancy is 8 percent at X/sub Ar/ + O. A systematic set of calculations has been made of 2 U> (Ar) and 2 U> (Kr) as a function of composition using radial distribution functions generated by the Weeks--Chandler--Anderson perturbation theory

  15. 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.

  16. High temperature solvent extraction of oil shale and bituminous coal using binary solvent mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Goetz, G.K.E. [Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle, RWTH Aachen (Germany)

    1997-12-31

    A high volatile bituminous coal from the Saar Basin and an oil shale from the Messel deposit, both Germany, were extracted with binary solvent mixtures using the Advanced Solvent Extraction method (ASE). Extraction temperature and pressure were kept at 100 C, respectively 150 C, and 20,7 MPa. After the heating phase (5 min) static extractions were performed with mixtures (v:v, 1:3) of methanol with toluene, respectively trichloromethane, for further 5 min. Extract yields were the same or on a higher level compared to those from classical soxhlet extractions (3 days) using the same solvents at 60 C. Comparing the results from ASE with those from supercritical fluid extraction (SFE) the extract yields were similar. Increasing the temperature in ASE releases more soluble organic matter from geological samples, because compounds with higher molecular weight and especially more polar substances were solubilized. But also an enhanced extraction efficiency resulted for aliphatic and aromatic hydrocarbons which are used as biomarkers in Organic Geochemistry. Application of thermochemolysis with tetraethylammonium hydroxide (TEAH) using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) on the extraction residues shows clearly that at higher extraction temperatures minor amounts of free fatty acids or their methyl esters (original or produced by ASE) were trapped inside the pore systems of the oil shale or the bituminous coal. ASE offers a rapid and very efficient extraction method for geological samples reducing analysis time and costs for solvents. (orig.)

  17. Modeling the [NTf2] pyridinium ionic liquids family and their mixtures with the soft statistical associating fluid theory equation of state.

    Science.gov (United States)

    Oliveira, M B; Llovell, F; Coutinho, J A P; Vega, L F

    2012-08-02

    In this work, the soft statistical associating fluid theory (soft-SAFT) equation of state (EoS) has been used to provide an accurate thermodynamic characterization of the pyridinium-based family of ionic liquids (ILs) with the bis(trifluoromethylsulfonyl)imide anion [NTf(2)](-). On the basis of recent molecular simulation studies for this family, a simple molecular model was proposed within the soft-SAFT EoS framework. The chain length value was transferred from the equivalent imidazolium-based ILs family, while the dispersive energy and the molecular parameters describing the cation-anion interactions were set to constant values for all of the compounds. With these assumptions, an appropriate set of molecular parameters was found for each compound fitting to experimental temperature-density data at atmospheric pressure. Correlations for the nonconstant parameters (describing the volume of the IL) with the molecular weight were established, allowing the prediction of the parameters for other pyridiniums not included in the fitting. Then, the suitability of the proposed model and its optimized parameters were tested by predicting high-pressure densities and second-order thermodynamic derivative properties such as isothermal compressibilities of selected [NTf(2)] pyridinium ILs, in a large range of thermodynamic conditions. The surface tension was also provided using the density gradient theory coupled to the soft-SAFT equation. Finally, the soft-SAFT EoS was applied to describe the phase behavior of several binary mixtures of [NTf(2)] pyridinium ILs with carbon dioxide, sulfur dioxide, and water. In all cases, a temperature-independent binary parameter was enough to reach quantitative agreement with the experimental data. The description of the solubility of CO(2) in these ILs also allowed identification of a relation between the binary parameter and the molecular weight of the ionic liquid, allowing the prediction of the CO(2) + C(12)py[NTf(2)] mixture. The good

  18. Isentropic expansion and related thermodynamic properties of non-ionic amphiphile-water mixtures.

    Science.gov (United States)

    Reis, João Carlos R; Douhéret, Gérard; Davis, Michael I; Fjellanger, Inger Johanne; Høiland, Harald

    2008-01-28

    A concise thermodynamic formalism is developed for the molar isentropic thermal expansion, ES,m = ( partial differential Vm/ partial differential T)(Sm,x), and the ideal and excess quantities for the molar, apparent molar and partial molar isentropic expansions of binary liquid mixtures. Ultrasound speeds were determined by means of the pulse-echo-overlap method in aqueous mixtures of 2-methylpropan-2-ol at 298.15 K over the entire composition range. These data complement selected extensive literature data on density, isobaric heat capacity and ultrasound speed for 9 amphiphile (methanol, ethanol, propan-1-ol, propan-2-ol, 2-methylpropan-2-ol, ethane-1,2-diol, 2-methoxyethanol, 2-ethoxyethanol or 2-butoxyethanol)-water binary systems, which form the basis of tables listing molar and excess molar isobaric expansions and heat capacities, and molar and excess molar isentropic compressions and expansions at 298.15 K and at 65 fixed mole fractions spanning the entire composition range and fine-grained in the water-rich region. The dependence on composition of these 9 systems is graphically depicted for the excess molar isobaric and isentropic expansions and for the excess partial molar isobaric and isentropic expansions of the amphiphile. The analysis shows that isentropic thermal expansion properties give a much stronger response to amphiphile-water molecular interactions than do their isobaric counterparts. Depending on the pair property-system, the maximum excess molar isentropic value is generally twenty- to a hundred-fold greater than the corresponding maximum isobaric value, and occurs at a lower mole fraction of the amphiphile. Values at infinite dilution of the 9 amphiphiles in water are given for the excess partial molar isobaric heat capacity, isentropic compression, isobaric expansion and isentropic expansion. These values are interpreted in terms of the changes occurring when amphiphile molecules cluster into an oligomeric form. Present results are discussed

  19. 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...

  20. 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…

  1. Experimental, theoretical and numerical interpretation of thermodiffusion separation for a non-associating binary mixture in liquid/porous layers

    International Nuclear Information System (INIS)

    Ahadi, Amirhossein; Jawad, H.; Saghir, M.Z.; Giraudet, C.; Croccolo, F.; Bataller, H.

    2014-01-01

    Thermodiffusion in a hydrocarbon binary mixture has been investigated experimentally and numerically in a liquid-porous cavity. The solutal separation of the 50% toluene and 50% n-hexane binary mixture induced by a temperature difference at atmospheric pressure has been performed in a new thermodiffusion cell. A new optimized cell design is used in this study. The inner part of the cell is a cylindrical porous medium sandwiched between two liquid layers of the same binary hydrocarbon mixture. Experimental measurement and theoretical estimation of the molecular diffusion and thermodiffusion coefficients showed a good agreement. In order to understand the different regimes occurring in the different parts of the cell, a full transient numerical simulation of the solutal separation of the binary mixture has been performed. Numerical results showed that the lighter species, which are of n-hexane migrated toward the hot surface, while the denser species, which is toluene migrated towards the cold surface. Also, it was found that a good agreement has been reached between experimental measurements and numerical calculations for the solutal separation between the hot and cold surface for different medium porosity. In addition, we used the numerical results to analyse convection and diffusion regions in the cell precisely. (authors)

  2. Crystal nucleation in binary hard-sphere mixtures: the effect of order parameter on the cluster composition

    NARCIS (Netherlands)

    Ni, R.; Smallenburg, F.; Filion, L.C.; Dijkstra, M.

    2011-01-01

    We study crystal nucleation in a binary mixture of hard spheres and investigate the composition and size of the (non)critical clusters using Monte Carlo simulations. In order to study nucleation of a crystal phase in computer simulations, a one-dimensional order parameter is usually defined to

  3. 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 calculation...

  4. 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)

  5. Study of thermodynamic and transport properties of binary liquid mixture of diesel with biodiesel at 298.15K

    Science.gov (United States)

    Suthar, Shyam Sunder; Purohit, Suresh

    2018-05-01

    Properties of diesel and biodiesel (produced from corn oil) are used. Densities and viscosities of binary mixture of diesel with biodiesel (produced from corn oil) have been computed by using liquid binary mixture law over the entire range of compositions at T=298.15K and atmospheric pressure. From the computed values of density and viscosities, viscosity deviation (Δη), the excess molar volume (VE) and excess Gibbs energy of activation of viscous flow (ΔG#E) have been calculated. The results of excess volume, excess Gibbs energy of activation of viscous flow and viscosity deviation have been fitted to Redlich -Kister models to estimate the binary coefficients. The results are communicated in terms of the molecular interactions and the best suited composition has been found.

  6. Heterogeneous structure and solvation dynamics of DME/water binary mixtures: A combined spectroscopic and simulation investigation

    Science.gov (United States)

    Das Mahanta, Debasish; Rana, Debkumar; Patra, Animesh; Mukherjee, Biswaroop; Mitra, Rajib Kumar

    2018-05-01

    Water is often found in (micro)-heterogeneous environments and therefore it is necessary to understand their H-bonded network structure in such altered environments. We explore the structure and dynamics of water in its binary mixture with relatively less polar small biocompatible amphiphilic molecule 1,2-Dimethoxyethane (DME) by a combined spectroscopic and molecular dynamics (MD) simulation study. Picosecond (ps) resolved fluorescence spectroscopy using coumarin 500 as the fluorophore establishes a non-monotonic behaviour of the mixture. Simulation studies also explore the various possible H-bond formations between water and DME. The relative abundance of such different water species manifests the heterogeneity in the mixture.

  7. Adsorption of binary gas mixtures in heterogeneous carbon predicted by density functional theory: on the formation of adsorption azeotropes.

    Science.gov (United States)

    Ritter, James A; Pan, Huanhua; Balbuena, Perla B

    2010-09-07

    Classical density functional theory (DFT) was used to predict the adsorption of nine different binary gas mixtures in a heterogeneous BPL activated carbon with a known pore size distribution (PSD) and in single, homogeneous, slit-shaped carbon pores of different sizes. By comparing the heterogeneous results with those obtained from the ideal adsorbed solution theory and with those obtained in the homogeneous carbon, it was determined that adsorption nonideality and adsorption azeotropes are caused by the coupled effects of differences in the molecular size of the components in a gas mixture and only slight differences in the pore sizes of a heterogeneous adsorbent. For many binary gas mixtures, selectivity was found to be a strong function of pore size. As the width of a homogeneous pore increases slightly, the selectivity for two different sized adsorbates may change from being greater than unity to less than unity. This change in selectivity can be accompanied by the formation of an adsorption azeotrope when this same binary mixture is adsorbed in a heterogeneous adsorbent with a PSD, like in BPL activated carbon. These results also showed that the selectivity exhibited by a heterogeneous adsorbent can be dominated by a small number of pores that are very selective toward one of the components in the gas mixture, leading to adsorption azeotrope formation in extreme cases.

  8. Modeling vapor liquid equilibrium of ionic liquids + gas binary systems at high pressure with cubic equations of state

    Directory of Open Access Journals (Sweden)

    A. C. D. Freitas

    2013-03-01

    Full Text Available Ionic liquids (IL have been described as novel environmentally benign solvents because of their remarkable characteristics. Numerous applications of these solvents continue to grow at an exponential rate. In this work, high pressure vapor liquid equilibria for 17 different IL + gas binary systems were modeled at different temperatures with Peng-Robinson (PR and Soave-Redlich-Kwong (SRK equations of state, combined with the van der Waals mixing rule with two binary interaction parameters (vdW-2. The experimental data were taken from the literature. The optimum binary interaction parameters were estimated by minimization of an objective function based on the average absolute relative deviation of liquid and vapor phases, using the modified Simplex algorithm. The solubilities of all gases studied in this work decrease as the temperature increases and increase with increasing pressure. The correlated results were highly satisfactory, with average absolute relative deviations of 2.10% and 2.25% for PR-vdW-2 and SRK-vdW-2, respectively.

  9. 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.

  10. 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

  11. 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

  12. Enzymatic synthesis of 6-O-glucosyl-poly(3-hydroxyalkanoate) in organic solvents and their binary mixture.

    Science.gov (United States)

    Gumel, A M; Annuar, M S M; Heidelberg, T

    2013-04-01

    The effects of organic solvents and their binary mixture in the glucose functionalization of bacterial poly-3-hydroxyalkanoates catalyzed by Lecitase™ Ultra were studied. Equal volume binary mixture of DMSO and chloroform with moderate polarity was more effective for the enzyme catalyzed synthesis of the carbohydrate polymer at ≈38.2 (±0.8)% reactant conversion as compared to the mono-phasic and other binary solvents studied. The apparent reaction rate constant as a function of medium water activity (aw) was observed to increase with increasing solvent polarity, with optimum aw of 0.2, 0.4 and 0.7 (±0.1) observed in hydrophilic DMSO, binary mixture DMSO:isooctane and hydrophobic isooctane, respectively. Molecular sieve loading between 13 to 15gL(-1) (±0.2) and reaction temperature between 40 to 50°C were found optimal. Functionalized PHA polymer showed potential characteristics and biodegradability. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. 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.

  14. Phase behaviors of binary mixtures composed of electron-rich and electron-poor triphenylene discotic liquid crystals

    International Nuclear Information System (INIS)

    An Lingling; Jing Min; Xiao Bo; Bai Xiao-Yan; Zhao Ke-Qing; Zeng Qing-Dao

    2016-01-01

    Disk-like liquid crystals (DLCs) can self-assemble to ordered columnar mesophases and are intriguing one-dimensional organic semiconductors with high charge carrier mobility. To improve their applicable property of mesomorphic temperature ranges, we exploit the binary mixtures of electronic donor-acceptor DLC materials. The electron-rich 2,3,6,7,10,11-hexakis(alkoxy)triphenylenes (C4, C6, C8, C10, C12) and an electron-deficient tetrapentyl triphenylene-2,3,6,10-tetracarboxylate have been prepared and their binary mixtures have been investigated. The mesomorphism of the 1:1 (molar ratio) mixtures has been characterized by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and small angel x-ray scattering (SAXS). The self-assembled monolayer structure of a discogen on a solid-liquid interface has been imaged by the high resolution scanning tunneling microscopy (STM). The match of peripheral chain length has important influence on the mesomorphism of the binary mixtures. (special topic)

  15. Validation of different spectrophotometric methods for determination of vildagliptin and metformin in binary mixture

    Science.gov (United States)

    Abdel-Ghany, Maha F.; Abdel-Aziz, Omar; Ayad, Miriam F.; Tadros, Mariam M.

    New, simple, specific, accurate, precise and reproducible spectrophotometric methods have been developed and subsequently validated for determination of vildagliptin (VLG) and metformin (MET) in binary mixture. Zero order spectrophotometric method was the first method used for determination of MET in the range of 2-12 μg mL-1 by measuring the absorbance at 237.6 nm. The second method was derivative spectrophotometric technique; utilized for determination of MET at 247.4 nm, in the range of 1-12 μg mL-1. Derivative ratio spectrophotometric method was the third technique; used for determination of VLG in the range of 4-24 μg mL-1 at 265.8 nm. Fourth and fifth methods adopted for determination of VLG in the range of 4-24 μg mL-1; were ratio subtraction and mean centering spectrophotometric methods, respectively. All the results were statistically compared with the reported methods, using one-way analysis of variance (ANOVA). The developed methods were satisfactorily applied to analysis of the investigated drugs and proved to be specific and accurate for quality control of them in pharmaceutical dosage forms.

  16. Application of normalized spectra in resolving a challenging Orphenadrine and Paracetamol binary mixture

    Science.gov (United States)

    Yehia, Ali M.; Abd El-Rahman, Mohamed K.

    2015-03-01

    Normalized spectra have a great power in resolving spectral overlap of challenging Orphenadrine (ORP) and Paracetamol (PAR) binary mixture, four smart techniques utilizing the normalized spectra were used in this work, namely, amplitude modulation (AM), simultaneous area ratio subtraction (SARS), simultaneous derivative spectrophotometry (S1DD) and ratio H-point standard addition method (RHPSAM). In AM, peak amplitude at 221.6 nm of the division spectra was measured for both ORP and PAR determination, while in SARS, concentration of ORP was determined using the area under the curve from 215 nm to 222 nm of the regenerated ORP zero order absorption spectra, in S1DD, concentration of ORP was determined using the peak amplitude at 224 nm of the first derivative ratio spectra. PAR concentration was determined directly at 288 nm in the division spectra obtained during the manipulation steps in the previous three methods. The last RHPSAM is a dual wavelength method in which two calibrations were plotted at 216 nm and 226 nm. RH point is the intersection of the two calibration lines, where ORP and PAR concentrations were directly determined from coordinates of RH point. The proposed methods were applied successfully for the determination of ORP and PAR in their dosage form.

  17. Collective modes across the soliton-droplet crossover in binary Bose mixtures

    Science.gov (United States)

    Cappellaro, Alberto; Macrı, Tommaso; Salasnich, Luca

    2018-05-01

    We study the collective modes of a binary Bose mixture across the soliton to droplet crossover in a quasi-one-dimensional waveguide with a beyond-mean-field equation of state and a variational Gaussian ansatz for the scalar bosonic field of the corresponding effective action. We observe a sharp difference in the collective modes in the two regimes. Within the soliton regime, modes vary smoothly upon the variation of particle number or interaction strength. On the droplet side, collective modes are inhibited by the emission of particles. This mechanism turns out to be dominant for a wide range of particle numbers and interactions. In a small window of particle number range and for intermediate interactions, we find that monopole frequency is likely to be observed. We focus on the spin-dipole modes for the case of equal intraspecies interactions and equal equilibrium particle numbers in the presence of a weak longitudinal confinement. We find that such modes might be unobservable in the real-time dynamics close to the equilibrium as their frequency is higher than the particle emission spectrum by at least one order of magnitude in the droplet phase. Our results are relevant for experiments with two-component Bose-Einstein condensates for which we provide realistic parameters.

  18. 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.

  19. 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.

  20. Chromatographic methods for the simultaneous determination of binary mixture of Saxagliptin HCl and Metformin HCl

    Directory of Open Access Journals (Sweden)

    Hanan A. Merey

    2017-12-01

    Full Text Available Two chromatographic methods were suggested for the simultaneous determination of a binary mixture containing Saxagliptin HCl (SAG and Metformin HCl (MET. First method was RP-HPLC method. Chromatographic separation was done on Kinetex™ column–C18 (4.6 × 150 mm, 2.6 µm using mobile phase consisted of acetonitrile:phosphate buffer pH = 4.5 ± 0.1 adjusted with orthophosphoric acid (13:87, v/v. Isocratic elution at a flow rate 1.5 mL/min and UV detection at 220.0 nm was performed. Second method was spectro-densitometric method. Chromatographic separation was done on precoated silica gel aluminium plates 60 F254 as a stationary phase and developing system consisting of chloroform:methanol:formic acid (80:20:0.3, by volume. The density of the separated bands was measured by UV detector at 210.0 nm. The proposed methods were validated as per the ICH guidelines parameters like Linearity, precision, accuracy, selectivity, limit of detection and limit of quantitation. Statistical comparison was done between the obtained results and those obtained by the reported methods, showing no significant difference with respect to accuracy and precision. Keywords: Saxagliptin HCl, Metformin HCl, RP-HPLC, TLC

  1. 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.

  2. 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.

  3. Molecular dynamics simulations of the structure and single-particle dynamics of mixtures of divalent salts and ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Gómez-González, Víctor; Docampo-Álvarez, Borja; Gallego, Luis J.; Varela, Luis M., E-mail: luismiguel.varela@usc.es [Grupo de Nanomateriais e Materia Branda, Departamento de Física da Materia Condensada, Universidade de Santiago de Compostela, Campus Vida s/n, E-15782 Santiago de Compostela (Spain); Cabeza, Oscar [Facultade de Ciencias, Universidade da Coruña, Campus A Zapateira s/n, E-15008 A Coruña (Spain); Fedorov, Maxim [Department of Physics, Scottish University Physics Alliance (SUPA), University of Strathclyde, John Anderson Bldg., 107 Rottenrow East, Glasgow G4 0NG (United Kingdom); Lynden-Bell, Ruth M. [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2015-09-28

    We report a molecular dynamics study of the structure and single-particle dynamics of mixtures of a protic (ethylammonium nitrate) and an aprotic (1-butyl-3-methylimidazolium hexaflurophosphate [BMIM][PF{sub 6}]) room-temperature ionic liquids doped with magnesium and calcium salts with a common anion at 298.15 K and 1 atm. The solvation of these divalent cations in dense ionic environments is analyzed by means of apparent molar volumes of the mixtures, radial distribution functions, and coordination numbers. For the protic mixtures, the effect of salt concentration on the network of hydrogen bonds is also considered. Moreover, single-particle dynamics of the salt cations is studied by means of their velocity autocorrelation functions and vibrational densities of states, explicitly analyzing the influence of salt concentration, and cation charge and mass on these magnitudes. The effect of the valency of the salt cation on these properties is considered comparing the results with those for the corresponding mixtures with lithium salts. We found that the main structural and dynamic features of the local solvation of divalent cations in ionic liquids are similar to those of monovalent salts, with cations being localized in the polar nanoregions of the bulk mixture coordinated in monodentate and bidentate coordination modes by the [NO{sub 3}]{sup −} and [PF{sub 6}]{sup −} anions. However, stronger electrostatic correlations of these polar nanoregions than in mixtures with salts with monovalent cations are found. The vibrational modes of the ionic liquid (IL) are seen to be scarcely affected by the addition of the salt, and the effect of mass and charge on the vibrational densities of states of the dissolved cations is reported. Cation mass is seen to exert a deeper influence than charge on the low-frequency vibrational spectra, giving a red shift of the vibrational modes and a virtual suppression of the higher energy vibrational modes for the heavier Ca{sup 2

  4. Molecular dynamics simulations of the structure and single-particle dynamics of mixtures of divalent salts and ionic liquids

    International Nuclear Information System (INIS)

    Gómez-González, Víctor; Docampo-Álvarez, Borja; Gallego, Luis J.; Varela, Luis M.; Cabeza, Oscar; Fedorov, Maxim; Lynden-Bell, Ruth M.

    2015-01-01

    We report a molecular dynamics study of the structure and single-particle dynamics of mixtures of a protic (ethylammonium nitrate) and an aprotic (1-butyl-3-methylimidazolium hexaflurophosphate [BMIM][PF 6 ]) room-temperature ionic liquids doped with magnesium and calcium salts with a common anion at 298.15 K and 1 atm. The solvation of these divalent cations in dense ionic environments is analyzed by means of apparent molar volumes of the mixtures, radial distribution functions, and coordination numbers. For the protic mixtures, the effect of salt concentration on the network of hydrogen bonds is also considered. Moreover, single-particle dynamics of the salt cations is studied by means of their velocity autocorrelation functions and vibrational densities of states, explicitly analyzing the influence of salt concentration, and cation charge and mass on these magnitudes. The effect of the valency of the salt cation on these properties is considered comparing the results with those for the corresponding mixtures with lithium salts. We found that the main structural and dynamic features of the local solvation of divalent cations in ionic liquids are similar to those of monovalent salts, with cations being localized in the polar nanoregions of the bulk mixture coordinated in monodentate and bidentate coordination modes by the [NO 3 ] − and [PF 6 ] − anions. However, stronger electrostatic correlations of these polar nanoregions than in mixtures with salts with monovalent cations are found. The vibrational modes of the ionic liquid (IL) are seen to be scarcely affected by the addition of the salt, and the effect of mass and charge on the vibrational densities of states of the dissolved cations is reported. Cation mass is seen to exert a deeper influence than charge on the low-frequency vibrational spectra, giving a red shift of the vibrational modes and a virtual suppression of the higher energy vibrational modes for the heavier Ca 2+ cations. No qualitative

  5. 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.

  6. 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.

  7. High-pressure phase behavior of systems with ionic liquids: Part V. The binary system carbon dioxide+1-butyl-3-methylimidazolium tetrafluoroborate

    NARCIS (Netherlands)

    Kroon, M.C.; Shariati - Sarabi, A.; Costantini, M.; Spronsen, van J.; Witkamp, G.J.; Sheldon, R.A.; Peters, C.J.

    2005-01-01

    The phase behavior of the binary system consisting of the supercritical fluid carbon dioxide (CO2) and the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) was studied experimentally. A synthetic method was used to measure its phase behavior. Bubble-point pressures of the

  8. 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

  9. Extension of mixture-of-experts networks for binary classification of hierarchical data.

    Science.gov (United States)

    Ng, Shu-Kay; McLachlan, Geoffrey J

    2007-09-01

    For many applied problems in the context of medically relevant artificial intelligence, the data collected exhibit a hierarchical or clustered structure. Ignoring the interdependence between hierarchical data can result in misleading classification. In this paper, we extend the mechanism for mixture-of-experts (ME) networks for binary classification of hierarchical data. Another extension is to quantify cluster-specific information on data hierarchy by random effects via the generalized linear mixed-effects model (GLMM). The extension of ME networks is implemented by allowing for correlation in the hierarchical data in both the gating and expert networks via the GLMM. The proposed model is illustrated using a real thyroid disease data set. In our study, we consider 7652 thyroid diagnosis records from 1984 to early 1987 with complete information on 20 attribute values. We obtain 10 independent random splits of the data into a training set and a test set in the proportions 85% and 15%. The test sets are used to assess the generalization performance of the proposed model, based on the percentage of misclassifications. For comparison, the results obtained from the ME network with independence assumption are also included. With the thyroid disease data, the misclassification rate on test sets for the extended ME network is 8.9%, compared to 13.9% for the ME network. In addition, based on model selection methods described in Section 2, a network with two experts is selected. These two expert networks can be considered as modeling two groups of patients with high and low incidence rates. Significant variation among the predicted cluster-specific random effects is detected in the patient group with low incidence rate. It is shown that the extended ME network outperforms the ME network for binary classification of hierarchical data. With the thyroid disease data, useful information on the relative log odds of patients with diagnosed conditions at different periods can be

  10. 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.

  11. 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)

  12. 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

  13. Comparative study on the selectivity of various spectrophotometric techniques for the determination of binary mixture of fenbendazole and rafoxanide.

    Science.gov (United States)

    Saad, Ahmed S; Attia, Ali K; Alaraki, Manal S; Elzanfaly, Eman S

    2015-11-05

    Five different spectrophotometric methods were applied for simultaneous determination of fenbendazole and rafoxanide in their binary mixture; namely first derivative, derivative ratio, ratio difference, dual wavelength and H-point standard addition spectrophotometric methods. Different factors affecting each of the applied spectrophotometric methods were studied and the selectivity of the applied methods was compared. The applied methods were validated as per the ICH guidelines and good accuracy; specificity and precision were proven within the concentration range of 5-50 μg/mL for both drugs. Statistical analysis using one-way ANOVA proved no significant differences among the proposed methods for the determination of the two drugs. The proposed methods successfully determined both drugs in laboratory prepared and commercially available binary mixtures, and were found applicable for the routine analysis in quality control laboratories. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. 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

  15. Study of the influence of diffusion on the flow velocity, for binary mixtures in Poiseuille and Couette flows

    International Nuclear Information System (INIS)

    Caetano Filho, E.

    1981-05-01

    The influence of diffusion on the flow of binary mixtures of incompressible fluids in POISEUILLE and COUETTE flows, is studied. The constitutive equations sugested by SAMPAIO and WILLIAMS and by STRUMINSKII for the constituent stress tensor and for the diffusive force are used. Results show that diffusion does not influence the flow in the case of planar and circular COUETTE flows. On the other hand, diffusion does play an important part in planar and circular POISEUILLE flows. (Author) [pt

  16. Antagonism in the extraction of uranium(VI) by the binary mixture of PC88A and benzimidazole

    International Nuclear Information System (INIS)

    Mukherjee, A.; Kamila, S.; Chakravortty, V.

    1999-01-01

    Extraction studies of uranium(VI) by the binary mixture of PC88A and benzimidazole show an antagonistic behavior in the concentration range 10 -5 -10 -6 M of PC88A and 0.005M of benzimidazole. Antagonism is observed due to the deprotonation of PC88A by benzimidazole forming an adduct resulting in the virtual removal of PC88A from the system. (author)

  17. The Solubility Parameters of Ionic Liquids

    Science.gov (United States)

    Marciniak, Andrzej

    2010-01-01

    The Hildebrand’s solubility parameters have been calculated for 18 ionic liquids from the inverse gas chromatography measurements of the activity coefficients at infinite dilution. Retention data were used for the calculation. The solubility parameters are helpful for the prediction of the solubility in the binary solvent mixtures. From the solubility parameters, the standard enthalpies of vaporization of ionic liquids were estimated. PMID:20559495

  18. The Solubility Parameters of Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Andrzej Marciniak

    2010-04-01

    Full Text Available The Hildebrand’s solubility parameters have been calculated for 18 ionic liquids from the inverse gas chromatography measurements of the activity coefficients at infinite dilution. Retention data were used for the calculation. The solubility parameters are helpful for the prediction of the solubility in the binary solvent mixtures. From the solubility parameters, the standard enthalpies of vaporization of ionic liquids were estimated.

  19. Excess Molar Volumes and Excess Molar Enthalpies in Binary Systems N-alkyl-triethylammonium bis(trifluoromethylsulfonyl)imide + Methanol

    Czech Academy of Sciences Publication Activity Database

    Machanová, Karolina; Troncoso, J.; Jacquemin, J.; Bendová, Magdalena

    2014-01-01

    Roč. 363, FEB 15 (2014), s. 156-166 ISSN 0378-3812 Institutional support: RVO:67985858 Keywords : ionic liquids * excess properties * binary mixtures Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.200, year: 2014

  20. The (gas + liquid) critical properties and phase behaviour of some binary alkanol (C2-C5) + alkane (C5-C12) mixtures

    International Nuclear Information System (INIS)

    Morton, David W.; Lui, Matthew P.W.; Young, Colin L.

    2003-01-01

    Previously, the investigation of the (gas + liquid) critical properties of (alkanol + alkane) mixtures has focussed on (primary alkanol + straight chain alkane) mixtures. The experimental data available for (alkanol + alkane) mixtures, which include secondary or tertiary alcohols and/or branched chain alkanes, are extremely limited. This work extends the existing body of data on (alkanol + alkane) mixtures to include mixtures containing these components. Here the (gas + liquid) critical temperatures of 29 {alkanol (C 2 -C 5 ) + alkane (C 5 -C 12 )} mixtures are reported. All the (gas + liquid) critical lines for the binary mixtures studied are continuous, indicating they obey either Type I or Type II phase behaviour

  1. Investigating magnetorheological properties of a mixture of two types of carbonyl iron powders suspended in an ionic liquid

    International Nuclear Information System (INIS)

    Dodbiba, Gjergj; Park, Hyun Seo; Okaya, Katsunori; Fujita, Toyohisa

    2008-01-01

    In this work, properties of a magnetorheological (MR) fluid, prepared by dispersing a mixture of two types of carbonyl iron powders (CIPs) of different sizes, in an ionic liquid (N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium tetrafluoroborate) that is stable from 9 deg. C to ca. 300 deg. C, have been investigated. At first, the random packing density of the mixture was computed as function of mixing ratio of CIP, in order to find out the tendency of the variation. Next, several mixtures, all having the same weight, were prepared at various mixing ratios and dispersed in the ionic liquid, in order to experimentally find the most suitable mixing ratio of CIP. Then, the magnetic clusters of the synthesized MR fluids were observed by using a digital microscope equipped with two permanent magnets, whereas the MR properties were investigated by using a rotation viscometer equipped with a solenoid coil. The experimental results pointed out that the MR fluid with 60 wt% fraction of large particles exhibited the highest MR response

  2. Liquid-liquid extraction of plutonium(IV) in monoamide - ammonium ionic liquid mixture

    International Nuclear Information System (INIS)

    Rout, Alok; Venkatesan, K.A.; Antony, M.P.

    2016-01-01

    Room temperature ionic liquid (RTIL) can be regarded as a sustainable alternative to the conventional molecular diluent, n-dodecane (n-DD), in solvent extraction process. Replacement of volatile organic solvents by RTILs in solvent extraction could lead to inherently safer processes. As far as the cation is concerned, most of the studies reported in literature are focused on imidazolium-based ionic liquids. In contrast to imiadazolium ionic liquids, quarternary ammonium ionic liquids like trioctylmethylammonium chloride (Aliquat 336), trioctylmethylammonium nitrate etc., do not exhibit any cation exchange with the metal ions from aqueous phase during extraction. However, there is no report available in literature that emphasizes the application of trioctylmethylammonium bis(trifluoromethane-sulfonyl)imide ((N_1_8_8_8)(NTf_2)) ionic liquid, for the extraction of Pu(IV). In this paper, we report the advantages of using the ionic liquid, trioctylmethylammonium bis(trifluoromethanesulfonyl)imide ((N_1_8_8_8)(NTf_2)), as diluent, for the extraction of plutonium(IV) in DHOA/(N_1_8_8_8)(NTf_2)

  3. Thermodynamic properties of binary mixtures containing dimethyl carbonate+2-alkanol: Experimental data, correlation and prediction by ERAS model and cubic EOS

    International Nuclear Information System (INIS)

    Almasi, Mohammad

    2013-01-01

    Densities and viscosities for binary mixtures of dimethyl carbonate with 2-propanol up to 2-heptanol were measured at various temperatures and ambient pressure. From experimental data, excess molar volumes, V m E . were calculated and correlated by the Redlich–Kister equation to obtain the binary coefficients and the standard deviations. Excess molar volumes, V m E , are positive for all studied mixtures over the entire range of the mole fraction. The ERAS-model has been applied for describing the binary excess molar volumes and also Peng–Robinson–Stryjek–Vera (PRSV) equation of state (EOS) has been used to predict the binary excess molar volumes and viscosities. Also several semi-empirical models were used to correlate the viscosity of binary mixtures

  4. Glass transition behaviour of the quaternary ammonium type ionic liquid, {[DEME][I] + H2O} mixtures

    International Nuclear Information System (INIS)

    Imai, Yusuke; Abe, Hiroshi; Matsumoto, Hitoshi; Shimada, Osamu; Hanasaki, Tomonori; Yoshimura, Yukihiro

    2011-01-01

    By a simple DTA system, the glass transition temperatures of the quaternary ammonium type ionic liquid, {N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium iodide, [DEME][I] + H 2 O} mixtures after quick pre-cooling were measured as a function of water concentration (x mol% H 2 O). Results were compared with the previous results of {[DEME][BF 4 ] + H 2 O} mixtures in which double glass transitions were observed in the water concentration region of (16.5 to 30.0) mol% H 2 O. Remarkably, we observed the double glass transition phenomenon in {[DEME][I] + H 2 O} mixtures too, but the two-T g s regions lie towards the water-rich side of (77.5 to 85.0) mol% H 2 O. These clearly reflect the difference in the anionic effect between BF 4 - and I - on the water structure. The end of the glass-formation region of {[DEME][I] + H 2 O} mixtures is around x = 95.0 mol% H 2 O, and this is comparable to that of {[DEME][BF 4 ] + H 2 O} mixtures (x = 96.0 mol% H 2 O).

  5. Application of Prigogine-Flory-Patterson theory to excess molar volume of mixtures of 1-butyl-3-methylimidazolium ionic liquids with N-methyl-2-pyrrolidinone

    International Nuclear Information System (INIS)

    Qi Feng; Wang Haijun

    2009-01-01

    The densities of two binary mixtures formed by 1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF 4 ] and 1-butyl-3-methy limidazolium hexafluorophosphate [bmim][PF 6 ] with compound N-methyl-2-pyrrolidinone have been determined over the full range of composition and range of temperature from (298.15 to 313.15) K and at atmospheric pressure using a vibrating-tube densimeter (DMA4500). Excess molar volumes, V m E , have been obtained from these experimental results, and been fitted by the fourth-order Redlich-Kister equation. From the experimental results, partial molar volumes, apparent molar volume and partial molar volumes at infinite dilution were calculated over the whole composition range. Our results show that V m E decreases slightly when temperature increases in the systems studied. The experimental results have been used to test the applicability of the Prigogine-Flory-Patterson (PFP) theory. The results have been interpreted in terms of ion-dipole interactions and structural factors of the ionic liquid and these organic molecular liquids

  6. An evaluation of three-dimensional modeling of compaction cycles by analyzing the densification behavior of binary and ternary mixtures.

    Science.gov (United States)

    Picker, K M; Bikane, F

    2001-08-01

    The aim of the study is to use the 3D modeling technique of compaction cycles for analysis of binary and ternary mixtures. Three materials with very different deformation and densification characteristics [cellulose acetate (CAC), dicalcium phosphate dihydrate (EM) and theophylline monohydrate (TM)] have been tableted at graded maximum relative densities (rhorel, max) on an eccentric tableting machine. Following that, graded binary mixtures from CAC and EM have been compacted. Finally, the same ratios of CAC and EM have been tableted in a ternary mixture with 20 vol% TM. All compaction cycles have been analyzed by using different data analysis methods. Three-dimensional modeling, conventional determination of the slope of the Heckel function, determination of the elastic recovery during decompression, and calculations according to the pressure-time function were the methods of choice. The results show that the 3D model technique is able to gain the information in one step instead of three different approaches, which is an advantage for formulation development. The results show that this model enables one to better distinguish the compaction properties of mixtures and the interaction of the components in the tablet than 2D models. Furthermore, the information by 3D modeling is more precise since in the slope K of the Heckel-plot (in die) elasticity is included, and in the parameters of the pressure-time function beta and gamma plastic deformation due to pressure is included. The influence of time and pressure on the displacement can now be differentiated.

  7. Environment effects on the optical properties of some fluorinated poly(oxadiazole ether)s in binary solvent mixtures

    International Nuclear Information System (INIS)

    Homocianu, Mihaela; Ipate, Alina Mirela; Hamciuc, Corneliu; Airinei, Anton

    2015-01-01

    The solvatochromic behavior of some fluorinated poly(oxadiazole ether)s was studied using UV–vis absorption and fluorescence spectroscopy in neat solvents and in their solvent mixtures at several ratios of cosolvents. Quantitative investigations of the spectral changes caused by solvent polarity were discussed using the Lippert‐Mataga, Bakhshiev and Kawski–Chamma–Viallet polarity functions. Repartitioning of cosolvent between local (solvation shell) and bulk phase was investigated by means of a solvatochromic shift method in chloroform–N,N-dimethylformamide (CHCl 3 /DMF) and chloroform–dimethyl sulfoxide (CHCl 3 /DMSO) solvent mixtures. Solvatochromic properties in the binary solvent environments were predominantly influenced by the acidity and basicity of the solvent systems. The fluorescence quenching process by nitrobenzene was characterized by Stern–Volmer plots which display a positive deviation from linearity. This was explained by static and dynamic quenching mechanisms. - Highlights: • Solvatochromic behavior in solvent mixtures was studied. • Stokes shift and local environments in binary mixed solvent were discussed. • Repartitioning of cosolvent between local and bulk phase in solvent mixture has been investigated. • Fluorescence intensity was quenched in presence of nitrobenzene

  8. Study of intermolecular interactions in binary mixtures of 2-(dimethylamino)ethanol with methanol and ethanol at various temperatures

    International Nuclear Information System (INIS)

    Pandey, Puneet Kumar; Pandey, Vrijesh Kumar; Awasthi, Anjali; Nain, Anil Kumar; Awasthi, Aashees

    2014-01-01

    Graphical abstract: The densities and ultrasonic speeds of the binary mixtures over the entire composition range were measured at various temperatures at atmospheric pressure. The excess molar volumes, isentropic compressibilities, and molar isentropic compressions have been calculated. The variations of these parameters with composition and temperature are discussed. The IR spectra were recorded they further supported the conclusion drawn from excess parameters, which indicates the presence of intermolecular hydrogen bonding between the oxygen atom of DMAE molecules and hydrogen atom of methanol and ethanol molecules in these mixtures.. - Highlights: • The study reports density and ultrasonic velocity data of 2-(dimethylamino)ethanol + methanol/ethanol mixtures. • To elucidate the interactions in 2-(dimethylamino)ethanol + methanol/ethanol binary mixtures. • Provides information on nature and relative strength of interactions in these mixtures. • Correlates physicochemical properties with interactions in these mixtures. - Abstract: The densities, ρ and ultrasonic speeds, u of the binary mixtures of 2-(dimethylamino)ethanol (DMAE) with methanol/ethanol, including those of pure liquids, over the entire composition range were measured at 298.15, 308.15 and 318.15 K. From the experimental data, the excess molar volumes, V m E and excess isentropic compressibilities, κ s E have been calculated. The excess partial molar volumes, V ¯ m,1 E and V ¯ m,2 E and excess partial molar isentropic compressions, K ¯ s,m,1 E and K ¯ s,m,2 E over the whole composition range; and partial molar volumes, V ¯ m,1 ° and V ¯ m,2 ° , partial molar isentropic compressions, K ¯ s,m,1 ° and K ¯ s,m,2 ° , excess partial molar volumes, V ¯ m,1 °E and V ¯ m,2 °E , and excess partial molar isentropic compressions, K ¯ s,m,1 °E and K ¯ s,m,2 °E at infinite dilution have also been calculated. The variations of these parameters with composition and temperature are

  9. Thermophysical properties of binary mixtures of triethoxysilane, methyltriethoxysilane, vinyltriethoxysilane and 3-mercaptopropyltriethoxysilane with ethylbenzene at various temperatures

    International Nuclear Information System (INIS)

    Zhang, Yindi; Dong, Hong; Wu, Chuan; Yu, Lijiao

    2014-01-01

    Highlights: • Values of ρ and n D of binary mixtures containing organosilicon compounds at different temperatures were measured. • α, V m E , V ¯ i E,∞ , (n 2 ) E , R m and ΔR m were studied. • The excess molar volumes, excess squared refraction indices and the deviations in molar refractions were negative. - Abstract: The density and refractive index were determined for binary mixtures of triethoxysilane, methyltriethoxysilane, vinyltriethoxysilane and 3-mercaptopropyltriethoxysilane with ethylbenzene at different temperatures (T = 288.15, 298.15, 308.15, 318.15 and 328.15 K) and atmospheric pressure using a DMA4500 and RXA170 combined system. The excess molar volume (V m E ), partial excess volume at infinite dilution (V ¯ i E,∞ ), isobaric coefficient of thermal expansion (α), excess squared refraction indices [(n 2 ) E ], Lorentz–Lorenz molar refraction (R m ) and the deviation in molar refraction (ΔR m ) have been calculated using this data. The results have been incorporated into the Redlich–Kister equation and used to estimate the binary interaction parameter and standard deviation. In addition, the excess molar volume (V m E ) was calculated and correlated using the Legendre polynomials. The value of partial excess volume at infinite dilution (V ¯ i E,∞ ) for these binary systems at different temperatures was calculated from either the adjustable parameters of Redlich–Kister smoothing equation or the Legendre polynomials. The isobaric coefficient of thermal expansion (α) of the binary systems was estimated using the temperature dependence of the densities. The results indicate that the excess molar volumes, excess squared refraction indices and the deviations in molar refractions at each temperature were negative. These phenomena are a result of a number of factors including: the partial interstitial accommodation effect, disruption in the orientational order of the pure components and steric structure

  10. Determination and modelling of osmotic coefficients and vapour pressures of binary systems 1- and 2-propanol with CnMimNTf2 ionic liquids (n = 2, 3, and 4) at T = 323.15 K

    International Nuclear Information System (INIS)

    Calvar, Noelia; Gomez, Elena; Dominguez, Angeles; Macedo, Eugenia A.

    2011-01-01

    Highlights: → Osmotic coefficients of 1- and 2-propanol with C n MimNTf 2 (n = 2, 3, and 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. → Effect of the anion is studied comparing these results with literature. - Abstract: The osmotic and activity coefficients and vapour pressures of binary mixtures containing 1-propanol, or 2-propanol and imidazolium-based ionic liquids with bis(trifluoromethylsulfonyl)imide as anion (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, C 2 MimNTf 2 , 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, C 3 MimNTf 2 , and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, C 4 MimNTf 2 ) were determined at T = 323.15 K using the vapour pressure osmometry technique. The experimental osmotic coefficients were correlated using the extended Pitzer model modified by Archer and the MNRTL model, obtaining standard deviations lower than 0.033 and 0.064, respectively. The mean molal activity coefficients and the excess Gibbs free energy for the mixtures studied were calculated from the parameters of the extended Pitzer model modified by Archer. Besides the effect of the alkyl-chain of the cation, the effect of the anion can be assessed comparing the experimental results with those previously obtained for imidazolium ionic liquids with sulphate anions.

  11. Prediction of (liquid + liquid) equilibrium for binary and ternary systems containing ionic liquids with the bis[(trifluoromethyl)sulfonyl]imide anion using the ASOG method

    International Nuclear Information System (INIS)

    Robles, Pedro A.; Cisternas, Luis A.

    2015-01-01

    Highlights: • ASOG model was used to predict LLE data for ionic liquid systems. • Twenty five binary and seven ternary systems that include the NTf 2 anion were used. • New group interaction parameters were determined. • The results are satisfactory, with rms deviations of about 3%. - Abstract: Ionic liquids are neoteric, environmentally friendly solvents (as they do not produce emissions) composed of large organic cations and relatively small inorganic anions. They have favorable physical properties, such as negligible volatility and a wide range of liquid existence. (Liquid + liquid) equilibrium (LLE) data for systems including ionic liquids, although essential for the design, optimization and operation of separation processes, remain scarce. However, some recent studies have presented ternary LLE data involving several ionic liquids and organic compounds such as alkanes, alkenes, alkanols, ethers and aromatics, as well as water. In this work, the ASOG model for the activity coefficient is used to predict LLE data for 25 binary and 07 ternary systems at 101.3 kPa and several temperatures; all the systems are formed by ionic liquids including the bis[(trifluoromethyl)sulfonyl]imide (NTf 2 ) anion plus alkanes, alkenes, cycloalkanes, alkanols, water, thiophene and aromatics. New group interaction parameters were determined using a modified Simplex method, minimizing a composition-based objective function of experimental data obtained from the literature. The results are satisfactory, with rms deviations of approximately 3%

  12. Determination and correlation of pyridoxine hydrochloride solubility in different binary mixtures at temperatures from (278.15 to 313.15) K

    International Nuclear Information System (INIS)

    Han, Dandan; Li, Xiaona; Wang, Haisheng; Wang, Yan; Du, Shichao; Yu, Bo; Liu, Yumin; Xu, Shijie; Gong, Junbo

    2016-01-01

    Highlights: • Solubility of pyridoxine hydrochloride in three binary mixtures was determined. • Experimental solubility of pyridoxine hydrochloride was correlated by four models. • Mixing thermodynamics of pyridoxine hydrochloride were calculated and discussed. - Abstract: The solubility of pyridoxine hydrochloride in binary solvent mixtures, including (acetone + water), (methanol + water) and (ethanol + water), was measured over temperature range from (278.15 to 313.15) K by a gravimetric method at atmospheric pressure (P = 0.1 MPa). The solubility increased with increasing temperature in binary solvent mixtures at constant solvent composition. Besides, the dissolving capacity of pyridoxine hydrochloride in the three binary solvent mixtures at constant temperature ranked as (methanol + water > ethanol + water > acetone + water) in general, partly depending on the polarity of the solvents. Additionally, the modified Apelblat equation, van’t Hoff equation, CNIBS/R–K model and Jouyban–Acree model were used to correlate the solubility data in binary mixtures, it turned out that all the selected thermodynamic models could give satisfactory results. Furthermore, the mixing thermodynamic properties of pyridoxine hydrochloride in different binary solvent mixtures were also calculated and discussed. The results indicate that the mixing process of pyridoxine hydrochloride in the selected solvents is exothermic.

  13. Vapor-liquid equilibrium prediction with pseudo-cubic equation of state for binary mixtures containing hydrogen, helium, or neon

    Energy Technology Data Exchange (ETDEWEB)

    Kato, M.; Tanaka, H. (Nihon Univ.,Fukushima, (Japan). Faculty of Enineering)

    1990-03-01

    As an equation of state of vapor-liquid equilibrium, an original pseudo-cubic equation of state was previously proposed by the authors of this report and its study is continued. In the present study, new effective critical values of hydrogen, helium and neon were determined empirically from vapor-liquid equilibrium data of literature values against their critical temperatures, critical pressures and critical volumes. The vapor-liquid equilibrium relations of binary system quantum gas mixtures were predicted combining the conventinal pseudo-cubic equation of state and the new effective critical values, and without using binary heteromolecular interaction parameter. The predicted values of hydrogen-ethylene, helium-propane and neon-oxygen systems were compared with literature values. As a result, it was indicated that the vapor-liquid relations of binary system mixtures containing hydrogen, helium and neon can be predicted with favorable accuracy combining the effective critical values and the three parameter pseudo-cubic equation of state. 37 refs., 3 figs., 4 tabs.

  14. Stability of binary complexes of Pb(II, Cd(II and Hg(II with maleic acid in TX100-water mixtures

    Directory of Open Access Journals (Sweden)

    M. Ramanaiah

    2014-09-01

    Full Text Available Binary complexes of maleic acid with toxic metal ions such as Pb(II, Cd(II and Hg(II have been studied in 0.0-2.5% v/v tritonX-100 (TX100 - water media at 303 K at an ionic strength of 0.16 M. The active forms of the ligand are LH2, LH- and L2-. The derived ‘best fit’ chemical speciation models are based on crystallographic R-factors, χ2 and Skewness and Kurtosis factors. The predominant species formed are of the type ML2, ML2H and ML3. The trend in variation of complex stability constants with change in the mole fraction of the medium is explained on the basis of prevailing electrostatic and non-electrostatic forces. The species distribution as a function of pH at different compositions of TX100-water mixtures and plausible speciation equilibria are presented and discussed. DOI: http://dx.doi.org/10.4314/bcse.v28i3.7

  15. 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

  16. Solute Transport from Aqueous Mixture through Supported Ionic Liquid Membrane by Pervaporation.

    Czech Academy of Sciences Publication Activity Database

    Izák, Pavel; Koekerling, M.; Kragl, U.

    2006-01-01

    Roč. 199, 1-3 (2006) , s. 96–98 ISSN 0011-9164. [Euromembrane 2006. Giardini, Naxos, 24.09.2006-28.09.2006] Institutional research plan: CEZ:AV0Z40720504 Keywords : supported ionic liquid membrane * pervaporation * 1,3-propanediol Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.917, year: 2006

  17. Solubility determination and thermodynamic modelling of allisartan isoproxil in different binary solvent mixtures from T = (278.15 to 313.15) K and mixing properties of solutions

    International Nuclear Information System (INIS)

    Yang, Yaoyao; Yang, Peng; Du, Shichao; Li, Kangli; Zhao, Kaifei; Xu, Shijie; Hou, Baohong; Gong, Junbo

    2016-01-01

    Highlights: • The solubility of allisartan isoproxil in binary solvent mixtures were determined. • Apelblat, CNIBS/R-K and Jouyban-Acree models were used to correlate the solubility. • Solubility parameter theory was used to explain the co-solvency phenomenon. • Regular mixing rules were used to calculate solubility parameter of binary solvents. • The mixing thermodynamics were calculated and discussed based on NRTL model. - Abstract: In this work, the solubility of allisartan isoproxil in binary solvent mixtures, including (acetone + water), (acetonitrile + water) and (methanol + water), was determined by a gravimetric method with the temperature ranging from (278.15 to 313.15) K at atmospheric pressure (p = 0.1 MPa). The solubility of allisartan isoproxil in three binary solvent mixtures all increased with the rising of temperature at a constant solvent composition. For the binary solvent mixtures of (methanol + water), the solubility increased with the increasing of methanol fraction, while it appeared maximum value at a certain solvent composition in the other two binary solvent mixtures (acetone + water and acetonitrile + water). Based on the theory of solubility parameter, Fedors method and two mixing rules were employed to calculate the solubility parameters, by which the proximity of solubility parameters between allisartan isoproxil and binary solvent mixtures explained the co-solvent phenomenon. Additionally, the modified Apelblat equation, CNIBS/R-K model and Jouyban-Acree model were used to correlate the solubility data in binary solvent mixtures, and it turned out that all the three correlation models could give a satisfactory result. Furthermore, the mixing thermodynamic properties were calculated based on NRTL model, which indicated that the mixing process was spontaneous and exothermic.

  18. Physical compatibility of binary and ternary mixtures of morphine and methadone with other drugs for parenteral administration in palliative care.

    Science.gov (United States)

    Destro, Massimo; Ottolini, Luca; Vicentini, Lorenza; Boschetti, Silvia

    2012-10-01

    The parenteral administration of combinations of drugs is often necessary in palliative medicine, particularly in the terminal stage of life, when patients are no longer able to take medication orally. The use of infusers to administer continuous subcutaneous infusions is a well-established practice in the palliative care setting and enables several drugs to be given simultaneously, avoiding the need for repeated administrations and the effects of peaks and troughs in the doses of medication. The method is also appreciated by patients and caregivers in the home care setting because the devices and infusion sites are easy to manage. Despite their frequent use, however, the mixtures of drugs adopted in clinical practice are sometimes not supported by reliable data concerning their chemical and physical compatibility. The present study investigates the chemical compatibility of binary mixtures (morphine with ketorolac) and the physical compatibility of binary (morphine or methadone with ketorolac) or ternary mixtures (morphine with ketorolac and/or haloperidol, and/or dexamethasone, and/or metoclopramide, and/or hyoscine butylbromide) with a view to reducing the aleatory nature of the empirical use of such combinations, thereby increasing their safety and clinical appropriateness.

  19. Quantitative NMR spectroscopy of binary liquid mixtures (aldehyde + alcohol) Part I: Acetaldehyde + (methanol or ethanol or 1-propanol)

    International Nuclear Information System (INIS)

    Jaubert, Silke; Maurer, Gerd

    2014-01-01

    Highlights: • Formation of hemiacetal/poly(oxymethylene) hemiacetals in liquid binary mixtures. • Acetaldehyde and a low molecular alcohol (methanol or ethanol or 1-propanol). • Quantitative 13 C NMR spectroscopy at temperatures between (255 and 295) K. • Hemiacetals are the predominant species. • (Acetaldehyde + methanol (50 + 50)) at 255 K: hemiacetal (polymers) >80% (≈10%). -- Abstract: Aldehydes react with alcohols to hemiacetals and poly(oxymethylene) hemiacetals. The chemical reaction equilibria of such reactions, in particular in the liquid state, can have an essential influence on the thermodynamic properties and related phenomena like, for example, on the vapour + liquid phase equilibrium. Therefore, thermodynamic models that aim to describe quantitatively such phase equilibria have to consider the chemical reaction equilibrium in the coexisting phases. This is well known in the literature for systems such as, for example, formaldehyde and methanol. However, experimental information on the chemical reaction equilibria in mixtures with other aldehydes (than formaldehyde) and alcohols is extremely scarce. Therefore, quantitative NMR spectroscopy was used to investigate the chemical reaction equilibria in binary mixtures of acetaldehyde and a single alcohol (here either methanol, ethanol or 1-propanol) at temperatures between (255 and 295) K. The results reveal that the majority of the constituents of the mixture is present as hemiacetal and the first two poly(oxymethylene) hemiacetals: in an equimolar mixture of (acetaldehyde + methanol or ethanol or 1-propanol), between about 90% at T = 255 K and about 75% at 295 K. The mole-fraction based chemical reaction equilibrium constants for the formation of those species were determined and some derived properties are reported

  20. 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

  1. 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

  2. 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.

  3. Thermodynamic analysis of an absorption refrigeration system with ionic-liquid/refrigerant mixture as a working fluid

    International Nuclear Information System (INIS)

    Kim, Yoon Jo; Kim, Sarah; Joshi, Yogendra K.; Fedorov, Andrei G.; Kohl, Paul A.

    2012-01-01

    Thermodynamics of an ionic-liquid (IL) based absorption refrigeration system has been numerically analyzed. It provides an alternative to the normally toxic working fluids, such as the ammonia in conventional absorption systems. The use of ILs also eliminates crystallization and metal-compatibility problems of the water/LiBr system. Mixtures of refrigerants and imidazolium-based ILs are theoretically explored as the working fluid pairs in a miniature absorption refrigeration system, so as to utilize waste-heat to power a refrigeration/heat pump system for electronics cooling. A non-random two-liquid (NRTL) model was built and used to predict the solubility of the mixtures. Saturation temperatures at the evaporator and condenser were set at 25 °C and 50 °C, respectively, with the power dissipation of 100 W. Water in combination with [emim][BF 4 ] (1-ethyl-3-methylimidazolium tetrafluoroborate) gave the highest coefficient of performance (COP) around 0.9. The refrigerant/IL compatibility indicated by the circulation ratio, alkyl chain length of the IL, and thermodynamic properties of the refrigerants, such as latent heat of evaporation were proven to be important factors in determining the performance of the absorption system. The negative effect of high viscosity was mitigated by dilution of the IL with the refrigerant and the use of slightly larger microfluidic channel heat exchangers. -- Highlights: ► Mixtures of refrigerant/ionic-liquid are studied for absorption system. ► We carry out comprehensive theoretical thermodynamic analysis. ► The essential factors of refrigerant/IL affecting the performance are identified. ► Water/[emim][BF 4 ] showed the best performance of COP. ► The effects of high viscosity ILs on the system performance are not significant.

  4. Phase equilibrium study of the binary systems (N-hexyl-3-methylpyridinium tosylate ionic liquid + water, or organic solvent)

    International Nuclear Information System (INIS)

    Domanska, Urszula; Krolikowski, Marek

    2011-01-01

    Highlights: → Synthesis, DSC, and measurements of phase equilibrium of N-hexyl-3-methylpyridinium tosylate. → Solvents used: water, alcohols, benzene, alkylbenzenes, and aliphatic hydrocarbons. → Correlation with UNIQUAC, Wilson and NRTL models. → Comparison with different tosylate-based ILs. - Abstract: The (solid + liquid) phase equilibrium (SLE) and (liquid + liquid) phase equilibrium (LLE) for the binary systems ionic liquid (IL) N-hexyl-3-methylpyridinium tosylate (p-toluenesulfonate), {([HM 3 Py][TOS] + water, or an alcohol (1-butanol, or 1-hexanol, or 1-octanol, or 1-decanol), or an aromatic hydrocarbon (benzene, toluene, or ethylbenzene, or propylbenzene), or an alkane (n-hexane, n-heptane, n-octane)} have been determined at ambient pressure using a dynamic method. Simple eutectic systems with complete miscibility in the liquid phase were observed for the systems involving water and alcohols. The phase equilibrium diagrams of IL and aromatic or aliphatic hydrocarbons exhibit eutectic systems with immiscibility in the liquid phase with an upper critical solution temperature as for most of the ILs. The correlation of the experimental data has been carried out using the UNIQUAC, Wilson and the non-random two liquid (NRTL) correlation equations. The results reported here have been compared with analogous phase diagrams reported by our group previously for systems containing the tosylate-based ILs.

  5. 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

  6. 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).

  7. 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.

  8. Diffusion coefficients in 4-component mixture expressed explicitly in terms of binary diffusion coefficients and mole fractions

    International Nuclear Information System (INIS)

    Furuta, Hiroshi; Yamamoto, Ichiro

    1996-01-01

    Diffusion coefficients in 4-component mixture D ij (4) were expressed explicitly in terms of binary diffusion coefficients and mole fractions by solving a ratio of determinants defined by Hirschfelder et al. The explicit expressions of D ij (4) were divided into two terms, a term due to the i-j pairs of attention and a term common to all the pairs out of the 4 components. The two terms of D ij (4) had extended structures similar to corresponding those of D ij (3) respectively. (author)

  9. Practical data correlation of flashpoints of binary mixtures by a reciprocal function: The concept and numerical examples

    Directory of Open Access Journals (Sweden)

    Hristova Mariana

    2011-01-01

    Full Text Available Simple data correlation of flashpoint data of binary mixture has been developed on a basic of rational reciprocal function. The new approximation requires has only two coefficients and needs the flashpoint temperature of the pure flammable component to be known. The approximation has been tested by literature data concerning aqueous-alcohol solution and compared to calculations performed by several thermodynamic models predicting flashpoint temperatures. The suggested approximation provides accuracy comparable and to some extent better than that of the thermodynamic methods.

  10. Modelling and nonlinear shock waves for binary gas mixtures by the discrete Boltzmann equation with multiple collisions

    International Nuclear Information System (INIS)

    Bianchi, M.P.

    1991-01-01

    The discrete Boltzmann equation is a mathematical model in the kinetic theory of gases which defines the time and space evolution of a system of gas particles with a finite number of selected velocities. Discrete kinetic theory is an interesting field of research in mathematical physics and applied mathematics for several reasons. One of the relevant fields of application of the discrete Boltzmann equation is the analysis of nonlinear shock wave phenomena. Here, a new multiple collision regular plane model for binary gas mixtures is proposed within the discrete theory of gases and applied to the analysis of the classical problems of shock wave propagation

  11. Experimental (solid + liquid) or (liquid + liquid) phase equilibria of (amine + nitrile) binary mixtures

    International Nuclear Information System (INIS)

    Domanska, Urszula; Marciniak, Malgorzata

    2007-01-01

    (Solid + liquid) phase diagrams have been determined for (hexylamine, or octylamine, or 1,3-diaminopropane + acetonitrile) mixtures. Simple eutectic systems have been observed in these mixtures. (Liquid + liquid) phase diagrams have been determined for (octylamine, or decylamine + propanenitrile, or + butanenitrile) mixtures. Mixtures with propanenitrile and butanenitrile show immiscibility in the liquid phase with an upper critical solution temperature, UCST. (Solid + liquid) phase diagrams have been correlated using NRTL, NRTL 1, Wilson and UNIQUAC equations. (Liquid + liquid) phase diagrams have been correlated using NRTL equation

  12. A nonlinear equation for ionic diffusion in a strong binary electrolyte

    Science.gov (United States)

    Ghosal, Sandip; Chen, Zhen

    2010-01-01

    The problem of the one-dimensional electro-diffusion of ions in a strong binary electrolyte is considered. The mathematical description, known as the Poisson–Nernst–Planck (PNP) system, consists of a diffusion equation for each species augmented by transport owing to a self-consistent electrostatic field determined by the Poisson equation. This description is also relevant to other important problems in physics, such as electron and hole diffusion across semiconductor junctions and the diffusion of ions in plasmas. If concentrations do not vary appreciably over distances of the order of the Debye length, the Poisson equation can be replaced by the condition of local charge neutrality first introduced by Planck. It can then be shown that both species diffuse at the same rate with a common diffusivity that is intermediate between that of the slow and fast species (ambipolar diffusion). Here, we derive a more general theory by exploiting the ratio of the Debye length to a characteristic length scale as a small asymptotic parameter. It is shown that the concentration of either species may be described by a nonlinear partial differential equation that provides a better approximation than the classical linear equation for ambipolar diffusion, but reduces to it in the appropriate limit. PMID:21818176

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

    Science.gov (United States)

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

    2015-12-01

    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.

  14. 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)

  15. Bubble-point and dew-point equation for binary refrigerant mixture R22-R142b

    Energy Technology Data Exchange (ETDEWEB)

    Liancheng Tan; Zhongyou Zhao; Yonghong Duan (Xi' an Jiaotong Univ., Xi' an (China). Dept. of Power Machinery Engineering)

    1992-01-01

    A bubble-point and dew-point equation (in terms either of temperature or of pressure is suggested for the refrigerant mixture R22-R142b), which is regarded as one of the alternatives to R12. This equation has been examined with experimental data. A modified Rackett equation for the calculation of the bubble-point volume is also proposed. Compared with the experimental data, the rms errors in the calculated values of the bubble-point temperature, the dew-point temperature, and the bubble-point volume are 1.093%, 0.947%, and 1.120%, respectively. The calculation covers a wide range of temperatures and pressures, even near the critical point. It is shown how the equations are extrapolated to calculate other binary refrigerant mixtures. (author)

  16. 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

    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...... and internal degrees of freedom leads to a rich phase structure that includes solid-liquid transitions (governed by the translational variables) as well as transitions involving changes in average disk size (governed by the internal variables). The relationship between these two types of transitions is studied...... 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...

  17. Generalisation to binary mixtures of the second gradient method and application to direct numerical simulation of nucleate boiling

    International Nuclear Information System (INIS)

    Fouillet, C.

    2003-01-01

    In this work, we simulate a nucleate boiling problem using direct numerical simulation. The numerical method used is the second gradient method based on a diffuse interface model which represents interfaces as volumetric regions of finite thickness across which the physical properties of the fluid vary continuously. First, this method is successfully applied to nucleate boiling of a pure fluid. Then, the model is extended to dilute binary mixtures. After studying its validity and its limits in simple configurations, it is then applied to nucleate boiling of a dilute mixture. These simulations show a strong decrease of the heat transfer coefficient as the concentration increases, in agreement with the numerous experimental studies published in this domain. (author) [fr

  18. Coupling of demixing and magnetic ordering phase transitions probed by turbidimetric measurements in a binary mixture doped with magnetic nanoparticles

    International Nuclear Information System (INIS)

    Hernandez-Diaz, Lorenzo; Hernandez-Reta, Juan Carlos; Encinas, Armando; Nahmad-Molinari, Yuri

    2010-01-01

    We present a novel study on the effect of a magnetic field applied on a binary mixture doped with magnetic nanoparticles close to its demixing transition. Turbidity measurements in the Faraday configuration show that the effect of applying an external field produces changes in the critical opalescence of the mixture that allow us to track an aggregation produced by critical Casimir forces and a reversible aggregation due to the formation of chain-like flocks in response to the external magnetic field. The observation of a crossover of the aggregation curves through optical signals is interpreted as the evolution from low to high power dispersion nuclei due to an increase in the radius of the condensation seed brought about by Casimir or magnetic interactions. Finally, evidence of an enhanced magnetocaloric effect due to the coupling between mixing and ordering phase transitions is presented which opens up a nonsolid state approach of designing refrigerating cycles and devices.

  19. Coupling of demixing and magnetic ordering phase transitions probed by turbidimetric measurements in a binary mixture doped with magnetic nanoparticles

    Science.gov (United States)

    Hernández-Díaz, Lorenzo; Hernández-Reta, Juan Carlos; Encinas, Armando; Nahmad-Molinari, Yuri

    2010-05-01

    We present a novel study on the effect of a magnetic field applied on a binary mixture doped with magnetic nanoparticles close to its demixing transition. Turbidity measurements in the Faraday configuration show that the effect of applying an external field produces changes in the critical opalescence of the mixture that allow us to track an aggregation produced by critical Casimir forces and a reversible aggregation due to the formation of chain-like flocks in response to the external magnetic field. The observation of a crossover of the aggregation curves through optical signals is interpreted as the evolution from low to high power dispersion nuclei due to an increase in the radius of the condensation seed brought about by Casimir or magnetic interactions. Finally, evidence of an enhanced magnetocaloric effect due to the coupling between mixing and ordering phase transitions is presented which opens up a nonsolid state approach of designing refrigerating cycles and devices.

  20. Coupling of demixing and magnetic ordering phase transitions probed by turbidimetric measurements in a binary mixture doped with magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Diaz, Lorenzo; Hernandez-Reta, Juan Carlos; Encinas, Armando; Nahmad-Molinari, Yuri, E-mail: yuri@ifisica.uaslp.m [Instituto de Fisica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, 78000 San Luis Potosi (Mexico)

    2010-05-19

    We present a novel study on the effect of a magnetic field applied on a binary mixture doped with magnetic nanoparticles close to its demixing transition. Turbidity measurements in the Faraday configuration show that the effect of applying an external field produces changes in the critical opalescence of the mixture that allow us to track an aggregation produced by critical Casimir forces and a reversible aggregation due to the formation of chain-like flocks in response to the external magnetic field. The observation of a crossover of the aggregation curves through optical signals is interpreted as the evolution from low to high power dispersion nuclei due to an increase in the radius of the condensation seed brought about by Casimir or magnetic interactions. Finally, evidence of an enhanced magnetocaloric effect due to the coupling between mixing and ordering phase transitions is presented which opens up a nonsolid state approach of designing refrigerating cycles and devices.

  1. Assessing interactions of binary mixtures of Penicillium mycotoxins (PMs) by using a bovine macrophage cell line (BoMacs)

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Se-Young, E-mail: ohs@uoguelph.ca [Department of Animal Biosciences, Ontario Agriculture College (OAC), University of Guelph, Guelph, ON N1G 2W1 (Canada); Cedergreen, Nina [Department of Life Sciences, University of Copenhagen, Frederiksberg (Denmark); Yiannikouris, Alexandros [Alltech Inc., Nicholasville, KY (United States); Swamy, H.V.L.N. [Trouw Nutrition Pvt. Ltd. India, Karnataka State 560065 (India); Karrow, Niel A., E-mail: nkarrow@uoguelph.ca [Department of Animal Biosciences, Ontario Agriculture College (OAC), University of Guelph, Guelph, ON N1G 2W1 (Canada)

    2017-03-01

    Penicillium mycotoxins (PMs) are toxic contaminants commonly found as mixtures in animal feed. Therefore, it is important to investigate potential joint toxicity of PM mixtures. In the present study, we assessed the joint effect of binary combinations of the following PMs: citrinin (CIT), ochratoxin A (OTA), patulin (PAT), mycophenolic acid (MPA) and penicillic acid (PA) using independent action (IA) and concentration addition (CA) concepts. Previously published toxicity data (i.e. IC25; PM concentration that inhibited bovine macrophage (BoMacs) proliferation by 25%) were initially analyzed, and both concepts agreed that OTA + PA demonstrated synergism (p < 0.05), while PAT + PA showed antagonism (p < 0.05). When a follow-up dilution study was carried out using binary combinations of PMs at three different dilution levels (i.e. IC25, 0.5 ∗ IC25, 0.25 ∗ IC25), only the mixture of CIT + OTA at 0.5 ∗ IC25 was determined to have synergism by both IA and CA concepts with Model Deviation Ratios (MDRs; the ratio of predicted versus observed effect concentrations) of 1.4 and 1.7, respectively. The joint effect of OTA + MPA, OTA + PA and CIT + PAT complied with the IA concept, while CIT + PA, PAT + MPA and PAT + PA were better predicted with the CA over the IA concept. The present study suggests to test both IA and CA concepts using multiple doses when assessing risk of mycotoxin mixtures if the mode of action is unknown. In addition, the study showed that the tested PMs could be predicted by IA or CA within an approximate two-fold certainty, raising the possibility for a joint risk assessment of mycotoxins in food and feed. - Highlights: • We investigated the potential joint toxicity of Penicillium mycotoxin (PM) mixtures. • Independent action (IA) and concentration addition (CA) concepts were used. • 7 out of 10 mixtures followed joint toxicity described by IA or CA concepts. • Both concepts agreed that CIT + OTA mixture had synergistic interaction.

  2. Assessing interactions of binary mixtures of Penicillium mycotoxins (PMs) by using a bovine macrophage cell line (BoMacs)

    International Nuclear Information System (INIS)

    Oh, Se-Young; Cedergreen, Nina; Yiannikouris, Alexandros; Swamy, H.V.L.N.; Karrow, Niel A.

    2017-01-01

    Penicillium mycotoxins (PMs) are toxic contaminants commonly found as mixtures in animal feed. Therefore, it is important to investigate potential joint toxicity of PM mixtures. In the present study, we assessed the joint effect of binary combinations of the following PMs: citrinin (CIT), ochratoxin A (OTA), patulin (PAT), mycophenolic acid (MPA) and penicillic acid (PA) using independent action (IA) and concentration addition (CA) concepts. Previously published toxicity data (i.e. IC25; PM concentration that inhibited bovine macrophage (BoMacs) proliferation by 25%) were initially analyzed, and both concepts agreed that OTA + PA demonstrated synergism (p < 0.05), while PAT + PA showed antagonism (p < 0.05). When a follow-up dilution study was carried out using binary combinations of PMs at three different dilution levels (i.e. IC25, 0.5 ∗ IC25, 0.25 ∗ IC25), only the mixture of CIT + OTA at 0.5 ∗ IC25 was determined to have synergism by both IA and CA concepts with Model Deviation Ratios (MDRs; the ratio of predicted versus observed effect concentrations) of 1.4 and 1.7, respectively. The joint effect of OTA + MPA, OTA + PA and CIT + PAT complied with the IA concept, while CIT + PA, PAT + MPA and PAT + PA were better predicted with the CA over the IA concept. The present study suggests to test both IA and CA concepts using multiple doses when assessing risk of mycotoxin mixtures if the mode of action is unknown. In addition, the study showed that the tested PMs could be predicted by IA or CA within an approximate two-fold certainty, raising the possibility for a joint risk assessment of mycotoxins in food and feed. - Highlights: • We investigated the potential joint toxicity of Penicillium mycotoxin (PM) mixtures. • Independent action (IA) and concentration addition (CA) concepts were used. • 7 out of 10 mixtures followed joint toxicity described by IA or CA concepts. • Both concepts agreed that CIT + OTA mixture had synergistic interaction.

  3. 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.

  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. Study of the binary mixtures of {monoglyme + (hexane, cyclohexane, octane, dodecane)} by ECM-average and PFP models

    International Nuclear Information System (INIS)

    Rivas, M.A.; Buep, A.H.; Iglesias, T.P.

    2015-01-01

    Highlights: • Polarization of the real mixture is less than that of the ideal mixture. • Molar excess volume does not exert the dominant effect on the polarization of the mixture. • Similar influence of molecular interactions on the behaviour of excess permittivity. • Excess molar volume is more influenced by the interactions than excess permittivity. - Abstract: Excess molar volumes and excess permittivity of binary mixtures involving monoglyme and alkanes, such as n-hexane, cyclohexane, n-octane and n-dodecane, were calculated from density and relative permittivity measurements for the entire composition range at several temperatures (288.15, 298.15 and 308.15) K and atmospheric pressure. The excess permittivity was calculated on the basis of a recent definition considering the ideal volume fraction. Empirical equations for describing the experimental data in terms of temperature and concentration are given. The experimental values of permittivity have been compared with those estimated by well-known models from literature. The results have indicated that better predictions are obtained when the volume change on mixing is incorporated in these calculations. The contribution of interactions to the excess permittivity was analysed by means of the ECM-average model. The Prigogine–Flory–Patterson (PFP) theory of the thermodynamics of solutions was used to shed light on the contribution of interactions to the excess molar volume. The work concludes with an interpretation of the information given by the theoretical models and the behaviour of both excess magnitudes

  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. Dielectric dispersion and thermodynamic behavior of stearic acid binary mixtures with alcohol as co-solvent using time domain reflectometry

    Directory of Open Access Journals (Sweden)

    M. Maria Sylvester

    2017-08-01

    Full Text Available Dielectric permittivity and relaxation dynamics of binary and ternary mixture of stearic acid on various concentration and their thermodynamic effects are studied. The static dielectric constant (ε0, dielectric permittivity (ε′ and dielectric loss (ε′′ are found by bilinear calibration. The relaxation time (τ, dielectric strength (Δε and the excess permittivity (εE are found. The thermodynamic parameters such as enthalpy (ΔH, entropy (ΔS and Gibb’s free energy (ΔG are evolved. The significant changes in dielectric parameters are due to the intramolecular and intermolecular interactions in response to the applied frequency. The permittivity spectra of stearic acid–alcohol in the frequency range of 10MHz to 30GHz have been measured using picoseconds Time Domain Reflectometry (TDR. The dielectric parameters (ε0, ε′, ε′′ are found by bilinear calibration method. Influence of temperature in intermolecular interaction and the relaxation process are also studied. The FT-IR spectral analysis reveals that the conformation of functional groups and formation for hydrogen bonding are present in both binary and ternary mixtures of stearic acid.

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

    International Nuclear Information System (INIS)

    Carareto, Natália D.D.; Santos, Adenílson O. dos; Rolemberg, Marlus P.; Cardoso, Lisandro P.; Costa, Mariana C.; Meirelles, Antonio J.A.

    2014-01-01

    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 −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

  9. 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.

  10. From ionic liquid to electrolyte solution: dynamics of 1-N-butyl-3-N-methylimidazolium tetrafluoroborate/dichloromethane mixtures.

    Science.gov (United States)

    Hunger, Johannes; Stoppa, Alexander; Buchner, Richard; Hefter, Glenn

    2008-10-16

    Dielectric spectra have been measured at 25 degrees C for mixtures of the room temperature ionic liquid 1- N-butyl-3- N-methylimidazolium tetrafluoroborate (IL) with dichloromethane (DCM) over the entire composition range at frequencies 0.2 less than or approximately nu/GHz < or = 89. The spectra could be satisfactorily fitted by assuming only two relaxation modes: a Cole-Cole process at lower frequencies and a Debye process at higher frequencies. However, detailed analysis indicated that both spectral features contain additional modes, which could not be resolved due to overlaps. The spectra indicate that the IL appears to retain its chemical character to extraordinarily high levels of dilution ( x IL greater than or approximately 0.5) in DCM. At even higher dilutions ( x IL less than or approximately 0.3), the IL behaves as a conventional but strongly associated electrolyte.

  11. Argentation gas chromatography revisited: Separation of light olefin/paraffin mixtures using silver-based ionic liquid stationary phases.

    Science.gov (United States)

    Nan, He; Zhang, Cheng; Venkatesh, Amrit; Rossini, Aaron J; Anderson, Jared L

    2017-11-10

    Silver ion or argentation chromatography utilizes stationary phases containing silver ions for the separation of unsaturated compounds. In this study, a mixed-ligand silver-based ionic liquid (IL) was evaluated for the first time as a gas chromatographic (GC) stationary phase for the separation of light olefin/paraffin mixtures. The selectivity of the stationary phase toward olefins can be tuned by adjusting the ratio of silver ion and the mixed ligands. The maximum allowable operating temperature of these stationary phases was determined to be between 125°C and 150°C. Nuclear magnetic resonance (NMR) spectroscopy was used to characterize the coordination behavior of the silver-based IL as well as provide an understanding into the retention mechanism of light olefins. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. 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

  13. Effective separation of propylene/propane binary mixtures by ZIF-8 membranes

    KAUST Repository

    Pan, Yichang; Li, Tao; Lestari, Gabriella; Lai, Zhiping

    2012-01-01

    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

  14. 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

  15. Comparison of methods for calculating thermodynamic properties of binary mixtures in the sub and super critical state: Lee-Kesler and cubic equations of state for binary mixtures containing either CO2 or H2S

    International Nuclear Information System (INIS)

    Yang, Jyisy; Griffiths, Peter R.; Goodwin, Anthony R.H.

    2003-01-01

    The (ρ,T,p) and (vapor + liquid) equilibria for fluid mixtures containing either CO 2 or H 2 S have been determined from 13 equations of state. The estimated values have been compared with published experimental results. CO 2 and H 2 S were used to represent non-polar and polar fluids, respectively. The equations of state investigated were as follows: (a) the Lee-Kesler equation; (b) two equations that included new reference fluids for the Lee-Kesler method; (c) three so-called extended equations of state; and (d) seven cubic equations of state. After adjustment of the binary interaction parameters the predicted values differed from the experimental data by about 0.8% for CO 2 mixtures while for H 2 S mixtures the uncertainty was about ±2.8%. Somewhat larger errors, although still lower than ±5%, were obtained for co-existing phase densities; the Lee-Kesler method provided results of the highest accuracy. The cubic equations proposed by Schmidt and Wenzel and Valderrama provide the most reliable predictions of both single and co-existing phase densities. Comparison of the predicted (vapor + liquid) equilibrium with experiment shows that each of the seven cubic equations provides results of similar accuracy and all within ±6%

  16. Shear viscosity for dense plasmas by equilibrium molecular dynamics in asymmetric Yukawa ionic mixtures

    Science.gov (United States)

    Haxhimali, Tomorr; Rudd, Robert E.; Cabot, William H.; Graziani, Frank R.

    2015-11-01

    We present molecular dynamics (MD) calculations of shear viscosity for asymmetric mixed plasma for thermodynamic conditions relevant to astrophysical and inertial confinement fusion plasmas. Specifically, we consider mixtures of deuterium and argon at temperatures of 100-500 eV and a number density of 1025 ions/cc. The motion of 30 000-120 000 ions is simulated in which the ions interact via the Yukawa (screened Coulomb) potential. The electric field of the electrons is included in this effective interaction; the electrons are not simulated explicitly. Shear viscosity is calculated using the Green-Kubo approach with an integral of the shear stress autocorrelation function, a quantity calculated in the equilibrium MD simulations. We systematically study different mixtures through a series of simulations with increasing fraction of the minority high-Z element (Ar) in the D-Ar plasma mixture. In the more weakly coupled plasmas, at 500 eV and low Ar fractions, results from MD compare very well with Chapman-Enskog kinetic results. In the more strongly coupled plasmas, the kinetic theory does not agree well with the MD results. We develop a simple model that interpolates between classical kinetic theories at weak coupling and the Murillo Yukawa viscosity model at higher coupling. This hybrid kinetics-MD viscosity model agrees well with the MD results over the conditions simulated, ranging from moderately weakly coupled to moderately strongly coupled asymmetric plasma mixtures.

  17. 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.

  18. Long-time tails of time correlation functions for an ionic mixture in a magnetic field and the validity of magnetohydrodynamics

    NARCIS (Netherlands)

    Suttorp, L.G.

    1990-01-01

    Mode-coupling theory is used to determine the long-time behaviour of the Green-Kubo integrands for the heat conductivity and the diffusion coefficients of an ionic mixture in a magnetic field. It is shown that the presence of several species of particles with a different ratio of charges and masses

  19. 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.

  20. 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.

  1. 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)

  2. 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...

  3. 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.

  4. 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

  5. Study of shear viscosity for dense plasmas by equilibrium molecular dynamics in asymmetric Yukawa ionic mixtures

    Science.gov (United States)

    Haxhimali, Tomorr; Rudd, Robert; Cabot, William; Graziani, Frank

    2015-11-01

    We present molecular dynamics (MD) calculations of shear viscosity for asymmetric mixed plasma for thermodynamic conditions relevant to astrophysical and Inertial Confinement Fusion plasmas. Specifically, we consider mixtures of deuterium and argon at temperatures of 100-500 eV and a number density of 1025 ions/cc. The motion of 30000-120000 ions is simulated in which the ions interact via the Yukawa (screened Coulomb) potential. The electric field of the electrons is included in this effective interaction. Shear viscosity is calculated using the Green-Kubo approach with an integral of the shear stress autocorrelation function, a quantity calculated in the equilibrium MD simulations. We study different mixtures with increasing fraction of the minority high-Z element (Ar) in the D-Ar plasma mixture. In the more weakly coupled plasmas, at 500 eV and low Ar fractions, results from MD compare very well with Chapman-Enskog kinetic results. We introduce a model that interpolates between a screened-plasma kinetic theory at weak coupling and the Murillo Yukawa viscosity model at higher coupling. This hybrid kinetics-MD viscosity model agrees well with the MD results over the conditions simulated. This work was performed under the auspices of the US Dept. of Energy by Lawrence Livermore National Security, LLC under Contract DE-AC52-07NA27344.

  6. Binary gas mixture adsorption-induced deformation of microporous carbons by Monte Carlo simulation.

    Science.gov (United States)

    Cornette, Valeria; de Oliveira, J C Alexandre; Yelpo, Víctor; Azevedo, Diana; López, Raúl H

    2018-07-15

    Considering the thermodynamic grand potential for more than one adsorbate in an isothermal system, we generalize the model of adsorption-induced deformation of microporous carbons developed by Kowalczyk et al. [1]. We report a comprehensive study of the effects of adsorption-induced deformation of carbonaceous amorphous porous materials due to adsorption of carbon dioxide, methane and their mixtures. The adsorption process is simulated by using the Grand Canonical Monte Carlo (GCMC) method and the calculations are then used to analyze experimental isotherms for the pure gases and mixtures with different molar fraction in the gas phase. The pore size distribution determined from an experimental isotherm is used for predicting the adsorption-induced deformation of both pure gases and their mixtures. The volumetric strain (ε) predictions from the GCMC method are compared against relevant experiments with good agreement found in the cases of pure gases. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Molecular dynamics simulation of a binary mixture near the lower critical point

    Energy Technology Data Exchange (ETDEWEB)

    Pousaneh, Faezeh; Edholm, Olle, E-mail: oed@kth.se [Theoretical Biological Physics, Department of Theoretical Physics, Royal Institute of Technology (KTH), AlbaNova University Center, SE-106 91 Stockholm (Sweden); Maciołek, Anna [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland); Max-Planck-Institut für Intelligente Systeme, Heisenbergstrasse 3, D-70569 Stuttgart (Germany)

    2016-07-07

    2,6-lutidine molecules mix with water at high and low temperatures but in a wide intermediate temperature range a 2,6-lutidine/water mixture exhibits a miscibility gap. We constructed and validated an atomistic model for 2,6-lutidine and performed molecular dynamics simulations of 2,6-lutidine/water mixture at different temperatures. We determined the part of demixing curve with the lower critical point. The lower critical point extracted from our data is located close to the experimental one. The estimates for critical exponents obtained from our simulations are in a good agreement with the values corresponding to the 3D Ising universality class.

  8. The structural and thermodynamical properties of binary ellipsoidal fluid mixture Gay-Berne interaction

    Directory of Open Access Journals (Sweden)

    M. Moradi

    2007-06-01

    Full Text Available  In this paper, a uniform classical fluid mixture comprising ellipsoidal molecules is studied. This mixture is composed of two types of ellipsoidal molecules interacting through the Gay-Berne potential with different sizes at temperature T. For this system, the Ornstein-Zernike equation using the Percus-Yevick closure relation is solved. Then the direct correlation function, pair correlation function and the pressure of the fluid at temperature T are calculated. The obtained results are in agreement with the previous theories and the results of molecular dynamic computer simulation.

  9. A combined experimental and theoretical approach to the study of hydrogen bond interaction in the binary mixture of N-methylimidazole with water

    International Nuclear Information System (INIS)

    Huang, Rongyi; Du, Rongbin; Liu, Guangxiang; Zhao, Xiuqin; Ye, Shiyong; Wu, Genhua

    2012-01-01

    Highlights: ► Densities of N-methylimidazole with water binary mixture were measured. ► Excess molar volumes were fitted to Redlich–Kister polynomial equation. ► Excess molar volumes are negative in the whole mole fraction range. ► 1:1 Hydrogen complex formation between the unlike components was observed. ► Formation of hydrogen bonds in the binary mixture was confirmed by DFT//B3LYP. - Abstract: The intermolecular hydrogen bond interactions in the N-methylimidazole (MeIm) with water binary mixture have been studied by a combined experimental and theoretical approach. The densities of the binary mixture have been measured at T = (288.15 to 323.15) K and at atmospheric pressure. From the experimental data, excess molar volumes were determined as a function of composition at each temperature. The results reveal the formation of 1:1 hydrogen bond complex between MeIm with water at the maximal excess molar volume. Meanwhile, the formation of hydrogen bonds in the binary mixture was further confirmed by high level theoretical calculation. The structures, interactional energies and bond characteristics of the hydrogen bond complexes were calculated in the gas phase using density functional theory (DFT) at the B3LYP/6-311++G(d, p) theory levels. The changes of thermodynamic properties from the monomers to hydrogen bond complexes with the temperature ranging from (288.15 to 323.15) K were obtained using the statistical thermodynamic method. Thermodynamic analyses have been interpreted in terms of intermolecular interactions and excess molar volume changes in the binary mixture. It was also found that the formation reaction of the hydrogen bond complex of MeIm with water was an exothermic, entropy reduced and spontaneous thermodynamic process at all the temperature studied.

  10. Synergic effects in the extraction of paracetamol from aqueous NaCl solution by the binary mixtures of diethyl ether and low molecular weight primary alcohols

    Science.gov (United States)

    Nikolić, G. M.; Živković, J. V.; Atanasković, D. S.; Nikolić, M. G.

    2013-12-01

    Liquid-liquid extraction of paracetamol from aqueous NaCl solutions was performed with diethyl ether, 1-propanol, 1-butanol, isobutanol, 1-pentanol, and binary mixtures diethyl ether/1-propanol, diethyl ether/1-butanol, and diethyl ether/isobutanol. Among the pure solvents investigated in this study best extraction efficacy was obtained with 1-butanol. Synergic effects in the extraction with binary mixtures was investigated and compared with some other systems used for the extraction of poorly extractable compounds. Results obtained in this study may be of both fundamental and practical importance.

  11. 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

  12. 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

  13. Nucleate boiling at the forced flow of binary non-azeotropic mixtures in horizontal tubes

    Directory of Open Access Journals (Sweden)

    Mezentseva N.N.

    2015-01-01

    Full Text Available Analysis of experimental values of heat transfer coefficients obtained through investigation of nucleate boiling of the two-component non-azeotropic mixtures inside the horizontal smooth tubes by various authors is presented. In the zone of nucleate boiling, the experimental data are in good agreement with the calculation dependence.

  14. 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

  15. Densities and volumetric properties of binary mixtures of xylene with N,N-dimethylformamide at different temperatures

    International Nuclear Information System (INIS)

    Chen Bin; Liu Wei

    2007-01-01

    Densities of binary mixtures of o-xylene, or m-xylene, or p-xylene with N,N-dimethylformamide have been measured over the full range of compositions at atmospheric pressure and various temperatures by means of a vibrating-tube densimeter. The excess molar volume V m E , calculated from the density data, provides the temperature dependence of V m E in the temperature range (293.15 to 353.15)K. The V m E results were correlated using the fourth-order Redlich-Kister polynomial equation, with the maximum likelihood principle being applied for the determination of the adjustable parameters. Partial molar volumes and excess partial molar volumes of two components were also calculated. It was found that the V m E in the systems studied increase with rising temperature

  16. 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.

  17. Radiolysis of nitrite, bromate and permanganate ions and their binary mixtures in aqueous solutions at pH 10

    International Nuclear Information System (INIS)

    Dedgaonkar, V.G.; Kulkarni, S.A.; Mahajan, C.T.

    1981-01-01

    #betta#-radiolysis of pure systems viz. nitrite, bromate and permanganate and their binary mixtures (MNO 4- /NO 2- , MnO 4- /BrO 3- ) in aqueous solution at pH 10 is studied as a function of dose and concentration. In pure systems the G(NO 3- ), G(Br - ) and G(-MnO 4- ) increase with increasing concentration. The first two show an identical limiting value of approximately 0.5 while the last increases from 0.68 below 10 4 M and reaches 2.5 at 10 - 2 M concentration. Presence of 10 - 1 M BrO 3- or 10 - 2 M NO 2- reduces the G(-MnO 4- ) from 1.07 for the pure 10 - 3 M permanganate solution to 0.2 and 0.7 respectively. A mechanism based on the competitive kinetics is envisaged to explain the observed results. (author)

  18. 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

  19. Solid-State FTIR Spectroscopic Study of Two Binary Mixtures: Cefepime-Metronidazole and Cefoperazone-Sulbactam

    Directory of Open Access Journals (Sweden)

    Hassan Refat H. Ali

    2017-01-01

    Full Text Available The structural information of the pharmaceuticals and insights on the modes of molecular interactions are very important aspects in drug development. In this work, two cephalosporins and antimicrobial combinations, cefepime-metronidazole and cefoperazone-sulbactam, were studied in the solid state using FTIR spectroscopy for the first time. Quantitation of the studied drugs and their binary mixtures was performed by integrating the peak areas of the characteristic well-resolved bands: υ (C=O band at 1773 cm−1 for cefepime and ring torsion band at 826 cm−1 for metronidazole and υ (C=O band at 1715 cm−1 for cefoperazone and ring torsion band at 1124 cm−1 for sulbactam. The results of this work were compared with the relevant spectrophotometric reported methods. This study provides data that can be used for the preparative process monitoring of the studied drugs in various dosage forms.

  20. Radiation-induced grafting from binary mixture of monomers onto cellulose acetate film and the characterization of the graft copolymer

    International Nuclear Information System (INIS)

    Bhattacharyya, S.N.; Maldas, D.

    1984-01-01

    Binary mixtures of styrene and acrylamide in methanol-water were grafted onto cellulose acetate films by taking recourse to preirradiation grafting technique. The extent of total grafting was determined from the measured weight increase. The percent acrylamide residue in the graft copolymer was calculated from the observed nitrogen content but the polystyrene residue in the grafted sample was determined by IR spectral studies. When the specific permeability of water vapour through the grafted films is measured, it is observed that the specific permeability increases with the increase of grafting of acrylamide in all humidities, but in case of styrene which is a nonpolar molecule the permeability is found to show a reversed order. In the case of mixed graft the permeability pattern pertains to that when both styrene and acrylamide have their effective roles to play. (author)

  1. Vapour pressure and excess Gibbs free energy of binary mixtures of hydrogen sulphide with ethane, propane, and n-butane at temperature of 182.33K

    International Nuclear Information System (INIS)

    Lobo, L.Q.; Ferreira, A.G.M.; Fonseca, I.M.A.; Senra, A.M.P.

    2006-01-01

    The vapour pressure of binary mixtures of hydrogen sulphide with ethane, propane, and n-butane was measured at T=182.33K covering most of the composition range. The excess Gibbs free energy of these mixtures has been derived from the measurements made. For the equimolar mixtures G m E (x 1 =0.5)=(835.5+/-5.8)J.mol -1 for (H 2 S+C 2 H 6 ) (820.1+/-2.4)J.mol -1 for (H 2 S+C 3 H 8 ), and (818.6+/-0.9)J.mol -1 for (H 2 S+n-C 4 H 10 ). The binary mixtures of H 2 S with ethane and with propane exhibit azeotropes, but that with n-butane does not

  2. 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.

  3. Phase-field modeling of mixing/demixing of regular binary mixtures with a composition-dependent viscosity

    Science.gov (United States)

    Lamorgese, A.; Mauri, R.

    2017-04-01

    We simulate the mixing (demixing) process of a quiescent binary liquid mixture with a composition-dependent viscosity which is instantaneously brought from the two-phase (one-phase) to the one-phase (two-phase) region of its phase diagram. Our theoretical approach follows a standard diffuse-interface model of partially miscible regular binary mixtures wherein convection and diffusion are coupled via a nonequilibrium capillary force, expressing the tendency of the phase-separating system to minimize its free energy. Based on 2D simulation results, we discuss the influence of viscosity ratio on basic statistics of the mixing (segregation) process triggered by a rapid heating (quench), assuming that the ratio of capillary to viscous forces (a.k.a. the fluidity coefficient) is large. We show that, for a phase-separating system, at a fixed value of the fluidity coefficient (with the continuous phase viscosity taken as a reference), the separation depth and the characteristic length of single-phase microdomains decrease monotonically for increasing values of the viscosity of the dispersed phase. This variation, however, is quite small, in agreement with experimental results. On the other hand, as one might expect, at a fixed viscosity of the dispersed phase both of the above statistics increase monotonically as the viscosity of the continuous phase decreases. Finally, we show that for a mixing system the attainment of a single-phase equilibrium state by coalescence and diffusion is retarded by an increase in the viscosity ratio at a fixed fluidity for the dispersed phase. In fact, for large enough values of the viscosity ratio, a thin film of the continuous phase becomes apparent when two drops of the minority phase approach each other, which further retards coalescence.

  4. Discrete unified gas kinetic scheme for all Knudsen number flows. III. Binary gas mixtures of Maxwell molecules

    Science.gov (United States)

    Zhang, Yue; Zhu, Lianhua; Wang, Ruijie; Guo, Zhaoli

    2018-05-01

    Recently a discrete unified gas kinetic scheme (DUGKS) in a finite-volume formulation based on the Boltzmann model equation has been developed for gas flows in all flow regimes. The original DUGKS is designed for flows of single-species gases. In this work, we extend the DUGKS to flows of binary gas mixtures of Maxwell molecules based on the Andries-Aoki-Perthame kinetic model [P. Andries et al., J. Stat. Phys. 106, 993 (2002), 10.1023/A:1014033703134. A particular feature of the method is that the flux at each cell interface is evaluated based on the characteristic solution of the kinetic equation itself; thus the numerical dissipation is low in comparison with that using direct reconstruction. Furthermore, the implicit treatment of the collision term enables the time step to be free from the restriction of the relaxation time. Unlike the DUGKS for single-species flows, a nonlinear system must be solved to determine the interaction parameters appearing in the equilibrium distribution function, which can be obtained analytically for Maxwell molecules. Several tests are performed to validate the scheme, including the shock structure problem under different Mach numbers and molar concentrations, the channel flow driven by a small gradient of pressure, temperature, or concentration, the plane Couette flow, and the shear driven cavity flow under different mass ratios and molar concentrations. The results are compared with those from other reliable numerical methods. The results show that the proposed scheme is an effective and reliable method for binary gas mixtures in all flow regimes.

  5. 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.

  6. Correlation and extrapolation scheme for the compostition and temperature dependence of viscosity of binary gaseous mixtures: Carbon dioxide + ethane

    International Nuclear Information System (INIS)

    Hendl, S.; Vogel, E.

    1995-01-01

    Experimental viscosity data of ethane, carbon dioxide, and three mole fractions of the binary system carbon dioxide + ethane in the temperature range 293.15≤T≤633.15 K and in the density range 0.01≤p≤0.05 mol · L -1 reported earlier were evaluated simultaneously to find out a useful correlation and extrapolation scheme for the viscosity of binary systems in the range of moderate densities. A procedure based on the ideas of the modified Enskog theory has been found to give the best results. Dependent on temperature, the collision diameters related to the equilibrium radial distribution function at contact are fitted to viscosity values of the pure substances and of at least one mixture. The results are compared with experimental data from the literature. A recommendation is given concerning the density range in which the first density contribution to the viscosity coefficient of the system carbon dioxide + ethane is sufficient to be included

  7. 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.

  8. 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

  9. 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.

  10. Dielectric Properties of Binary Solvent Mixtures of Dimethyl Sulfoxide with Water

    Science.gov (United States)

    Yang, Li-Jun; Yang, Xiao-Qing; Huang, Ka-Ma; Jia, Guo-Zhu; Shang, Hui

    2009-01-01

    In this paper, the dielectric properties of water-dimethylsulfoxide (DMSO) mixtures with different mole ratios have been investigated in the range of 1 GHz to 40 GHz at 298 K by using a molecular dynamics (MD) simulation. Only one dielectric loss peak was observed in the frequency range and the relaxation in these mixtures can be described by a single relaxation time of the Davidson-Cole. It was observed that within experimental error the dielectric relaxation can be described by the Debye-like model (β ≈ 1, S.M. Puranik, et al. J. Chem. Soc. Faraday Trans. 1992, 88, 433 – 435). In general, the results are very consistent with the experimental measurements. PMID:19399247

  11. Dielectric Properties of Binary Solvent Mixtures of Dimethyl Sulfoxide with Water

    Directory of Open Access Journals (Sweden)

    Li-Jun Yang

    2009-03-01

    Full Text Available In this paper, the dielectric properties of water-dimethylsulfoxide (DMSO mixtures with different mole ratios have been investigated in the range of 1 GHz to 40 GHz at 298 K by using a molecular dynamics (MD simulation. Only one dielectric loss peak was observed in the frequency range and the relaxation in these mixtures can be described by a single relaxation time of the Davidson-Cole. It was observed that within experimental error the dielectric relaxation can be described by the Debye-like model (β ≈ 1, S.M. Puranik, et al. J. Chem. Soc. Faraday Trans.1992, 88, 433 - 435. In general, the results are very consistent with the experimental measurements.

  12. Experimental study on thermal conductivity of He-Ar binary mixture at low temperatures

    International Nuclear Information System (INIS)

    Nesterov, N.A.

    1977-01-01

    The results of the experimental and theoretical investigation of helium-argon mixture thermal conductivity for three concentrations of helium (25,50 and 75%) in the 90-273 K temperature range at 1 atm. pressure are presented. At the calculation of the thermal conductivity coefficients corrections for the heat removal from the heater ends, for radiation and temperature drop in the wall of a glass tube and a measuring cell have been considered. On the basis of the thermal conductivity coefficient values the empiric concentration dependences of the mixture thermal conductivity are obtained by the method of least squares at different temperatures. Experimental data have been compared with theoretical values of thermal conductivity, calculated according to the molecular-kinetic theory. The results of this investigation can be used for determining potential energy of interparticle interaction and studying heat exchange processes at the external flow over body

  13. Structure and properties of binary polystyrene-epoxy acrylate oligomer mixtures irradiated by electron beams

    International Nuclear Information System (INIS)

    Lomonosova, N.V.

    1995-01-01

    The change in the structure of oriented polymer-oligomer systems based on polystyrene (PS) with M > 10 6 and epoxy acrylate oligomers (aliphatic and aromatic) under irradiation by accelerated electrons was studied using birefringence, isometric heating, IR dichroism, and thermooptical analysis. Mechanical properties of these systems were investigated. It was found that, by adding aliphatic epoxy acrylate to PS and further irradiating this mixture, one can obtain both isotropic and oriented composites with higher strengths, elasticity moduli, and glass transition temperatures

  14. On the balance equations for a dilute binary mixture in special relativity

    International Nuclear Information System (INIS)

    Moratto, Valdemar; Garcia-Perciante, A. L.; Garcia-Colin, L. S.

    2010-01-01

    In this work we study the properties of a relativistic mixture of two non-reacting species in thermal local equilibrium. We use the full Boltzmann equation (BE) to find the general balance equations. Following conventional ideas in kinetic theory, we use the concept of chaotic velocity. This is a novel approach to the problem. The resulting equations will be the starting point of the calculation exhibiting the correct thermodynamic forces and the corresponding fluxes; these results will be published elsewhere.

  15. 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

  16. 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

  17. Fluorescence quenching of newly synthesized biologically active coumarin derivative by aniline in binary solvent mixtures

    International Nuclear Information System (INIS)

    Evale, Basavaraj G.; Hanagodimath, S.M.

    2009-01-01

    The fluorescence quenching of newly synthesized coumarin (chromen-2-one) derivative, 4-(5-methyl-3-furan-2-yl-benzofuran-2-yl)-7-methyl-chromen-2-one (MFBMC) by aniline in different solvent mixtures of benzene and acetonitrile was determined at room temperature (296 K) by steady-state fluorescence measurements. The quenching is found to be appreciable and positive deviation from linearity was observed in the Stern-Volmer (S-V) plots in all the solvent mixtures. This could be explained by static and dynamic quenching models. The positive deviation in the S-V plot is interpreted in terms of ground-state complex formation model and sphere of action static quenching model. Various rate parameters for the fluorescence quenching process have been determined by using the modified Stern-Volmer equation. The sphere of action static quenching model agrees very well with experimental results. The dependence of Stern-Volmer constant K SV , on dielectric constant ε of the solvent mixture suggests that the fluorescence quenching is diffusion-limited. Further with the use of finite sink approximation model, it is concluded that these bimolecular quenching reactions are diffusion-limited. Using lifetime (τ o ) data, the distance parameter R' and mutual diffusion coefficient D are estimated independently.

  18. 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.

  19. 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-...

  20. 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.

  1. 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.

  2. Dirichlet Process Gaussian-mixture model: An application to localizing coalescing binary neutron stars with gravitational-wave observations

    Science.gov (United States)

    Del Pozzo, W.; Berry, C. P. L.; Ghosh, A.; Haines, T. S. F.; Singer, L. P.; Vecchio, A.

    2018-06-01

    We reconstruct posterior distributions for the position (sky area and distance) of a simulated set of binary neutron-star gravitational-waves signals observed with Advanced LIGO and Advanced Virgo. We use a Dirichlet Process Gaussian-mixture model, a fully Bayesian non-parametric method that can be used to estimate probability density functions with a flexible set of assumptions. The ability to reliably reconstruct the source position is important for multimessenger astronomy, as recently demonstrated with GW170817. We show that for detector networks comparable to the early operation of Advanced LIGO and Advanced Virgo, typical localization volumes are ˜104-105 Mpc3 corresponding to ˜102-103 potential host galaxies. The localization volume is a strong function of the network signal-to-noise ratio, scaling roughly ∝ϱnet-6. Fractional localizations improve with the addition of further detectors to the network. Our Dirichlet Process Gaussian-mixture model can be adopted for localizing events detected during future gravitational-wave observing runs, and used to facilitate prompt multimessenger follow-up.

  3. 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.

  4. 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.)

  5. 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.

  6. Flory-Huggins parameter χ, from binary mixtures of Lennard-Jones particles to block copolymer melts

    International Nuclear Information System (INIS)

    Chremos, Alexandros; Nikoubashman, Arash; Panagiotopoulos, Athanassios Z.

    2014-01-01

    In this contribution, we develop a coarse-graining methodology for mapping specific block copolymer systems to bead-spring particle-based models. We map the constituent Kuhn segments to Lennard-Jones particles, and establish a semi-empirical correlation between the experimentally determined Flory-Huggins parameter χ and the interaction of the model potential. For these purposes, we have performed an extensive set of isobaric–isothermal Monte Carlo simulations of binary mixtures of Lennard-Jones particles with the same size but with asymmetric energetic parameters. The phase behavior of these monomeric mixtures is then extended to chains with finite sizes through theoretical considerations. Such a top-down coarse-graining approach is important from a computational point of view, since many characteristic features of block copolymer systems are on time and length scales which are still inaccessible through fully atomistic simulations. We demonstrate the applicability of our method for generating parameters by reproducing the morphology diagram of a specific diblock copolymer, namely, poly(styrene-b-methyl methacrylate), which has been extensively studied in experiments

  7. 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.

    2017-01-01

    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...

  8. Flory-Huggins parameter χ, from binary mixtures of Lennard-Jones particles to block copolymer melts

    Energy Technology Data Exchange (ETDEWEB)

    Chremos, Alexandros, E-mail: achremos@imperial.ac.uk [Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Nikoubashman, Arash, E-mail: arashn@princeton.edu; Panagiotopoulos, Athanassios Z. [Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

    2014-02-07

    In this contribution, we develop a coarse-graining methodology for mapping specific block copolymer systems to bead-spring particle-based models. We map the constituent Kuhn segments to Lennard-Jones particles, and establish a semi-empirical correlation between the experimentally determined Flory-Huggins parameter χ and the interaction of the model potential. For these purposes, we have performed an extensive set of isobaric–isothermal Monte Carlo simulations of binary mixtures of Lennard-Jones particles with the same size but with asymmetric energetic parameters. The phase behavior of these monomeric mixtures is then extended to chains with finite sizes through theoretical considerations. Such a top-down coarse-graining approach is important from a computational point of view, since many characteristic features of block copolymer systems are on time and length scales which are still inaccessible through fully atomistic simulations. We demonstrate the applicability of our method for generating parameters by reproducing the morphology diagram of a specific diblock copolymer, namely, poly(styrene-b-methyl methacrylate), which has been extensively studied in experiments.

  9. 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

  10. Measurement and modelling of high pressure density and interfacial tension of (gas + n-alkane) binary mixtures

    International Nuclear Information System (INIS)

    Pereira, Luís M.C.; Chapoy, Antonin; Burgass, Rod; Tohidi, Bahman

    2016-01-01

    Highlights: • (Density + IFT) measurements are performed in synthetic reservoir fluids. • Measured systems include CO_2, CH_4 and N_2 with n-decane. • Novel data are reported for temperatures up to 443 K and pressures up to 69 MPa. • Predictive models are tested in 16 (gas + n-alkane) systems. • Best modelling results are achieved with the Density Gradient Theory. - Abstract: The deployment of more efficient and economical extraction methods and processing facilities of oil and gas requires the accurate knowledge of the interfacial tension (IFT) of fluid phases in contact. In this work, the capillary constant a of binary mixtures containing n-decane and common gases such as carbon dioxide, methane and nitrogen was measured. Experimental measurements were carried at four temperatures (313, 343, 393 and 442 K) and pressures up to 69 MPa, or near the complete vaporisation of the organic phase into the gas-rich phase. To determine accurate IFT values, the capillary constants were combined with saturated phase density data measured with an Anton Paar densitometer and correlated with a model based on the Peng–Robinson 1978 equation of state (PR78 EoS). Correlated density showed an overall percentage absolute deviation (%AAD) to measured data of (0.2 to 0.5)% for the liquid phase and (1.5 to 2.5)% for the vapour phase of the studied systems and P–T conditions. The predictive capability of models to accurately describe both the temperature and pressure dependence of the saturated phase density and IFT of 16 (gas + n-alkane) binary mixtures was assessed in this work by comparison with data gathered from the literature and measured in this work. The IFT models considered include the Parachor, the Linear Gradient Theory (LGT) and the Density Gradient Theory (DGT) approaches combined with the Volume-Translated Predictive Peng–Robinson 1978 EoS (VT-PPR78 EoS). With no adjustable parameters, the VT-PPR78 EoS allowed a good description of both solubility and

  11. Bubble-point measurement for the binary mixture of propargyl acrylate and propargyl methacrylate in supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Baek, Seung-Hyun; Byun, Hun-Soo

    2016-01-01

    Highlights: • Phase behaviours for the (CO_2 + propargyl (meth)acrylate) systems by static method were measured. • (P, x) isotherms is obtained at pressures up to 19.14 MPa and at temperature of (313.2 to 393.2) K. • The (CO_2 + propargyl acrylate) and (CO_2 + propargyl methacrylate) systems exhibit type-I behaviour. - Abstract: Acrylate and methacrylate (acrylic acid type) are compounds with weak polarity which show a non-ideal behaviour. Phase behaviour of these systems play a significant role as organic solvents in industrial processes. High pressure phase behaviour data were reported for binary mixture of propargyl acrylate and propargyl methacrylate in supercritical carbon dioxide. The bubble-point curves for the (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl methacrylate) mixtures were measured by static view cell apparatus at temperature range from 313.2 K to 393.2 K and at pressures below 19.14 MPa. The (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl methacrylate) systems exhibit type-I phase behaviour. The (carbon dioxide + (meth)acrylate) systems had continuous critical mixture curves with maximums in pressure located between the critical temperatures of carbon dioxide and propargyl acrylate or carbon dioxide and propargyl methacrylate. The solubility behaviour of propargyl (meth)acrylate in the (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl acrylate) systems increases as the temperature increases at a fixed pressure. The experimental results for the (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl methacrylate) systems correlate with the Peng–Robinson equation of state using a van der Waals one-fluid mixing rule. The critical properties of propargyl acrylate and propargyl methacrylate were predicted with the Joback–Lyderson group contribution and Lee–Kesler method.

  12. 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.

  13. 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.)

  14. Ultrasonic study on molecular interactions in binary mixtures of formamide with 1-propanol or 2-propanol

    Institute of Scientific and Technical Information of China (English)

    Manju Rani; Suman Gahlyan; Ankur Gaur; Sanjeev Maken

    2015-01-01

    Ultrasonic speeds have been measured at 298.15 K and 308.15 K for mixtures of formamide+1-propanol or 2-propanol. For an equimolar mixture, excess molar compressibility follows the sequence of 1-propanol N 2-propanol. The ultrasonic speed data are correlated by various correlations such as Nomoto's relation, van Dael's mixing relation and impedance dependence relation, and analyzed in terms of Jacobson's free length theory and Schaaff's collision factor theory. Excess isentropic compressibility is calculated from ex-perimental ultrasonic speed data and previously reported excess volume data. The excess molar ultrasonic speed and isentropic compressibility values are fitted to Redlich–Kister polynomial equation. Other proper-ties such as molecular association, avallable volume, free volume, and intermolecular free length are also calculated. The excess isentropic compressibility data are also interpreted in terms of graph theoretical ap-proach. The calculated isentropic compressibility values are well consistent with the experimental data. It is found that the interaction between formamide and propanol increases when hydroxyl group attached to a carbon atom has more–CH3 groups.

  15. Determination and modeling of the solubility of (limonin in methanol or acetone + water) binary solvent mixtures at T = 283.2 K to 318.2 K

    International Nuclear Information System (INIS)

    Fan, Jie-Ping; Zheng, Bing; Liao, Dan-Dan; Yu, Jia-Xin; Cao, Ya-Hui; Zhang, Xue-Hong; Zhu, Jian-Hang

    2016-01-01

    Highlights: • The solubilities of limonin were measured in the binary solvent mixtures methanol + water and acetone + water. • The solubility data were correlated by nine models. • The solubility of limonin had a maximum point at 0.9 mol fraction of acetone in acetone + water mixtures. - Abstract: The solubility of limonin in the binary solvent mixtures (methanol + water) and (acetone + water) with various initial mole fractions of methanol or acetone was measured by high-performance liquid chromatography (HPLC) at different temperatures ranging from 283.2 K to 318.2 K. The solubility of limonin increased with increasing initial mole fraction of methanol in (methanol + water) mixtures, whereas it had a maximum point at 0.9 mol fraction of acetone in (acetone + water) mixtures. The solubility of limonin increased with increasing temperature in the two binary solvent mixtures. The solubility of limonin was correlated with temperature by the van’t Hoff model and the modified Apelblat model, and the fitting results showed that the modified Apelblat model had better correlation. The CNIBS/Redlich–Kister model and the simplified CNIBS/Redlich–Kister model were used to correlate the solubility data with the initial solvent composition, the results show that the CNIBS/Redlich–Kister model reveals better agreement with the experimental values. Furthermore, to illustrate the effects of both temperature and initial solvent composition on the changes in the solubility of limonin, the solubility values were fitted by the Jouyban–Acree, van’t Hoff–Jouyban–Acree, modified Apelblat–Jouyban–Acree, Ma and Sun models. Among the five models, the Jouyban–Acree model give the best correlation results for (methanol + water) binary solvent mixtures, while the experimental solubility in the (acetone + water) system was most accurately correlated by the van’t Hoff–Jouyban–Acree model.

  16. 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

  17. Structural and interactional behaviour of aqueous mixture of room temperature ionic liquid; 2-hydroxyethyl-trimethylammonium L-lactate

    International Nuclear Information System (INIS)

    Chaudhary, Ganga Ram; Bansal, Shafila; Mehta, S.K.; Ahluwalia, A.S.

    2014-01-01

    Highlights: • Thermophysical and spectroscopic properties of aqueous mixtures 2-[HE3MA]LAC have been measured. • Effect of temperature on thermophysical properties has also been studied. • Stronger intermolecular have been observed between [HE3MA]LAC and H 2 O. • Magnitude of interactions decreases with the rise in temperature. • Spectroscopic studies shows interactions between -N + -(CH 3 ) 3 with -OH - group and COO − with -H + of IL and H 2 O. - Abstract: In order to understand the molecular interactions between the green solvent system, (water + lactate based ionic liquid); 2-hydroxyethyl-trimethylammonium L-lactate ([(C 2 H 4 OH)(CH 3 ) 3 N][Lactate]), the thermophysical properties viz. density ρ, speed of sound u, specific conductivity κ, refractive index n D and spectroscopic properties viz. IR, 1 H and 13 C NMR have been investigated over the whole composition range at atmospheric pressure with temperature varied from (293.15 to 323.15) K. To gain more insight of intermolecular interactions occurring in the aqueous mixture of [(C 2 H 4 OH)(CH 3 ) 3 N][Lactate], intermolecular free length L f , acoustic impedance Z, relative association R A , excess molar volume V E , deviations in isentropic compressibility ΔK S , partial molar excess volume V i E , partial molar deviations in isentropic compressibility ΔK S,i , deviation in specific conductivity Δκ and deviation in refractive index Δn D have been predicted as a function of IL concentration over the whole composition range. These results have been fitted to the Redlich–Kister polynomial. A large deviation from ideality has been observed on mixing water and [(C 2 H 4 OH)(CH 3 ) 3 N][Lactate] which are due to the formation of strong intermolecular hydrogen bonding between the two molecules. Also, it has been noticed that the mixture of water and [(C 2 H 4 OH)(CH 3 ) 3 N][Lactate] became warm that indicates mixing of these two components is exothermic. Thermodynamic and spectroscopic data

  18. Binary mixture of DDT and Arochlor1254: effects on sperm release by Danio rerio.

    Science.gov (United States)

    Njiwa, Jules Richard Kemadjou; Müller, Paul; Klein, Roland

    2004-06-01

    A long-term toxicity test with zebrafish was carried out with different concentrations of DDT, Arochlor1254 (A54), and their 1:1 mixture under flow-through conditions. By collecting and counting the number of sperm released during separate mating events we observed that gametes are released asynchronously. Sperms are released in the form of sperm trails laid on the nest surface; subsequently active spermatozoa leave the trails and move in the water for several minutes. Sperm trails consist of bands of viscous material in which sperm are embedded. The water samples for the estimation of sperm presence were collected gradually within 180 min after 24 h, 2 weeks, 1 month, and 2 months of exposure. It was established that the reductions in count, activity of sperm, and average life span of sperm trails were significant (Psperm release and activity as well as the life span of their trails.

  19. Three different spectrophotometric methods manipulating ratio spectra for determination of binary mixture of Amlodipine and Atorvastatin

    Science.gov (United States)

    Darwish, Hany W.; Hassan, Said A.; Salem, Maissa Y.; El-Zeiny, Badr A.

    2011-12-01

    Three simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra are developed for the simultaneous determination of Amlodipine besylate (AM) and Atorvastatin calcium (AT) in tablet dosage forms. The first method is first derivative of the ratio spectra ( 1DD), the second is ratio subtraction and the third is the method of mean centering of ratio spectra. The calibration curve is linear over the concentration range of 3-40 and 8-32 μg/ml for AM and AT, respectively. These methods are tested by analyzing synthetic mixtures of the above drugs and they are applied to commercial pharmaceutical preparation of the subjected drugs. Standard deviation is <1.5 in the assay of raw materials and tablets. Methods are validated as per ICH guidelines and accuracy, precision, repeatability and robustness are found to be within the acceptable limit.

  20. 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.

  1. 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.

  2. Development of a New Binary Solvent System Using Ionic Liquids as Additives to Improve Rotenone Extraction Yield from Malaysia Derris sp.

    Directory of Open Access Journals (Sweden)

    Zetty Shafiqa Othman

    2015-01-01

    Full Text Available Rotenone is one of the prominent insecticidal isoflavonoid compounds which can be isolated from the extract of Derris sp. plant. Despite being an effective compound in exterminating pests in a minute concentration, procuring a significant amount of rotenone in the extracts for commercialized biopesticides purposes is a challenge to be attained. Therefore, the objective of this study was to determine the best ionic liquid (IL which gives the highest yield of rotenone. The normal soaking extraction (NSE method was carried out for 24 hrs using five different types of binary solvent systems comprising a combination of acetone and five respective ionic liquids (ILs of (1 [BMIM] Cl; (2 [BMIM] OAc; (3 [BMIM] NTf2; (4 [BMIM] OTf; and (5 [BMPy] Cl. Next, the yield of rotenone, % (w/w, and its concentration (mg/mL in dried roots were quantitatively determined by means of RP-HPLC and TLC. The results showed that a binary solvent system of [BMIM] OTf + acetone was the best solvent system combination as compared to other solvent systems (P<0.05. It contributed to the highest rotenone content of 2.69 ± 0.21% (w/w (4.04 ± 0.34 mg/mL at 14 hrs of exhaustive extraction time. In conclusion, a combination of the ILs with a selective organic solvent has been proven to increase a significant amount of bioactive constituents in the phytochemical extraction process.

  3. 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

  4. Ionic molar volumes in methanol mixtures with acetonitrile, N,N-dimethylformamide and propylene carbonate at T = 298.15 K

    International Nuclear Information System (INIS)

    Pietrzak, A.; Piekarski, H.

    2014-01-01

    Highlights: • Densities of electrolyte solutions in methanol mixtures were measured at T = 298.15 K. • Apparent molar volumes of sodium cation and iodide anion were determined. • TPTB as a calculation method was used. • Preferential solvation of ions by organic solvents was examined. - Abstract: The densities of dilute solutions of three electrolytes (NaI, NaBPh 4 and Ph 4 PI) in methanol mixtures with propylene carbonate (PC), N,N-dimethylformamide (DMF) and acetonitrile (AN) have been measured by Anton Paar 5000 densimeter at T = 298.15 K. Apparent molar volumes, V Φ have been determined at an electrolyte concentration of 0.06 mol · kg −1 over the entire mixed solvent composition range. Single ionic apparent molar volumes of transfer, Δ t V Φ (ion) were calculated using the tetraphenylphosphonium tetraphenylborate (TPTB) assumption. The results are discussed in terms of ionic preferential solvation

  5. 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

  6. Measurement and correlation of vapour pressures of pyridine and thiophene with [EMIM][SCN] ionic liquid

    International Nuclear Information System (INIS)

    Khelassi-Sefaoui, Asma; Mutelet, Fabrice; Mokbel, Ilham; Jose, Jacques; Negadi, Latifa

    2014-01-01

    Highlights: • VLE of (pyridine + [EMIM][SCN]), or (thiophene + [EMIM][SCN]) binary mixtures were measured. • The investigated temperatures are 273 K to 363 K. • The PC-SAFT equation of state has been used to correlate the vapour pressures of the binary systems. - Abstract: In this work (vapour + liquid) equilibrium (VLE) measurements were performed on binary systems of the ionic liquid 1-ethyl-3-methylimidazolium thiocynate [EMIM][SCN] with thiophene or pyridine at pressures close to the atmospheric pressure using a static device at temperatures between 273 K and 363 K. Experimental data were correlated by the PC-SAFT EoS. The binary interaction parameters k ij were optimised on experimental VLE data. The results obtained for the two binary mixtures studied in this paper indicate that the PC-SAFT EoS can be used to represent systems containing ionic liquids

  7. Enhanced photovoltaic performance and long-term stability of dye-sensitized solar cells by incorporating SiO{sub 2} nanoparticles in binary ionic liquid electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hsin-Fang; Wu, Jhih-Lin; Hsu, Po-Ya [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC (China); Tung, Yung-Liang [Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu 30013, Taiwan, ROC (China); Ouyang, Fan-Yi [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC (China); Kai, Ji-Jung, E-mail: jjkai@ess.nthu.edu.tw [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC (China)

    2013-02-01

    Hydrophilic SiO{sub 2} nanoparticles in a binary ionic liquid (bi-IL) consisting of 1-propyl-3-methylimidazolium iodide (PMII) and 1-ethyl-3-methyl-imidazolium dicyanimide (EMIDCA) facilitated electron transfer and solidified the electrolyte for a dye-sensitized solar cell (DSC). We investigated the dependence of charge transport and photovoltaic performance on the composition of bi-IL electrolytes with varied ratio of SiO{sub 2} nanoparticles. The electrochemical impedance spectra revealed a decreased resistance to charge transfer at the Pt counter electrode (R{sub ct1}) when SiO{sub 2} (up to 2.0 wt.%) was added, improving the photovoltaic parameters. The DSC based on a TiO{sub 2} nanocrystalline film (thickness 14.2 μm) with a composite ionic gel electrolyte of EMIDCA/PMII bi-IL (33 vol.% of EMIDCA) incorporating SiO{sub 2} (2 wt.%) exhibited a power conversion efficiency of 5.28% under simulated solar illumination (AM 1.5 G, 100 mW cm{sup −} {sup 2}). The durability of DSC with a SiO{sub 2} solidified electrolyte was superior to that of a liquid one, exhibiting good stability at 60 °C in darkness during an accelerated test for 1000 h. - Highlights: ► SiO{sub 2} nanoparticles were introduced in a binary ionic liquid electrolyte. ► Effect of various ratios of SiO{sub 2} nanoparticles in gel electrolytes was studied. ► Mechanism of charge transfer with addition of SiO{sub 2} nanoparticles was discussed. ► An enhanced solar to electric energy conversion efficiency of 5.28% was achieved. ► Thermal stability of a quasi-solid state dye-sensitized solar cell was improved.

  8. 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

  9. Performance of supercritical Brayton cycle using CO2-based binary mixture at varying critical points for SFR applications

    International Nuclear Information System (INIS)

    Jeong, Woo Seok; Jeong, Yong Hoon

    2013-01-01

    Highlights: • Supercritical CO 2 -based gas mixture Brayton cycles were investigated for a SFR. • The critical point of CO 2 is the lowest cycle operating limit of the S-CO 2 cycles. • Mixing additives with CO 2 changes the CO 2 critical point. • CO 2 –Xe and CO 2 –Kr cycles achieve higher cycle efficiencies than the S-CO 2 cycles. • CO 2 –H 2 S and CO 2 –cyclohexane cycles perform better at higher heat sink temperatures. -- Abstract: The supercritical carbon dioxide Brayton cycle (S-CO 2 cycle) has attracted much attention as an alternative to the Rankine cycle for sodium-cooled fast reactors (SFRs). The higher cycle efficiency of the S-CO 2 cycle results from the considerably decreased compressor work because the compressor behaves as a pump in the proximity of the CO 2 vapor–liquid critical point. In order to fully utilize this feature, the main compressor inlet condition should be controlled to be close to the critical point of CO 2 . This indicates that the critical point of CO 2 is a constraint on the minimum cycle condition for S-CO 2 cycles. Modifying the CO 2 critical point by mixing additive gases could be considered as a method of enhancing the performance and broadening the applicability of the S-CO 2 cycle. Due to the drastic fluctuations of the thermo-physical properties of fluids near the critical point, an in-house cycle analysis code using the NIST REFPROP database was implemented. Several gases were selected as potential additives considering their thermal stability and chemical interaction with sodium in the temperature range of interest and the availability of the mixture property database: xenon, krypton, hydrogen sulfide, and cyclohexane. The performances of the optimized CO 2 -containing binary mixture cycles with simple recuperated and recompression layouts were compared with the reference S-CO 2 , CO 2 –Ar, CO 2 –N 2 , and CO 2 –O 2 cycles. For the decreased critical temperatures, the CO 2 –Xe and CO 2

  10. Comparative Investigation of the Ionicity of Aprotic and Protic Ionic Liquids in Molecular Solvents by using Conductometry and NMR Spectroscopy.

    Science.gov (United States)

    Thawarkar, Sachin; Khupse, Nageshwar D; Kumar, Anil

    2016-04-04

    Electrical conductivity (σ), viscosity (η), and self-diffusion coefficient (D) measurements of binary mixtures of aprotic and protic imidazolium-based ionic liquids with water, dimethyl sulfoxide, and ethylene glycol were measured from 293.15 to 323.15 K. The temperature dependence study reveals typical Arrhenius behavior. The ionicities of aprotic ionic liquids were observed to be higher than those of protic ionic liquids in these solvents. The aprotic ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate, [bmIm][BF4 ], displays 100 % ionicity in both water and ethylene glycol. The protic ionic liquids in both water and ethylene glycol are classed as good ionic candidates, whereas in DMSO they are classed as having a poor ionic nature. The solvation dynamics of the ionic species of the ionic liquids are illustrated on the basis of the (1) H NMR chemical shifts of the ionic liquids. The self-diffusion coefficients D of the cation and anion of [HmIm][CH3 COO] in D2 O and in [D6 ]DMSO are determined by using (1) H nuclei with pulsed field gradient spin-echo NMR spectroscopy. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Particle interaction of lubricated or unlubricated binary mixtures according to their particle size and densification mechanism.

    Science.gov (United States)

    Di Martino, Piera; Joiris, Etienne; Martelli, Sante

    2004-09-01

    The aim of this study is to assess an experimental approach for technological development of a direct compression formulation. A simple formula was considered composed by an active ingredient, a diluent and a lubricant. The active ingredient and diluent were selected as an example according to their typical densification mechanism: the nitrofurantoine, a fragmenting material, and the cellulose microcrystalline (Vivapur), which is a typical visco-elastic material, equally displaying good bind and disintegrant properties. For each ingredient, samples of different particle size distribution were selected. Initially, tabletability of pure materials was studied by a rotary press without magnesium stearate. Vivapur tabletability decreases with increase in particle size. The addition of magnesium stearate as lubricant decreases tabletability of Vivapur of greater particle size, while it kept unmodified that of Vivapur of lower particle size. Differences in tabletability can be related to differences in particle-particle interactions; for Vivapur of higher particle size (Vivapur 200, 102 and 101), the lower surface area develops lower surface available for bonds, while for Vivapur of lower particle size (99 and 105) the greater surface area allows high particle proximity favouring particle cohesivity. Nitrofurantoine shows great differences in compression behaviour according to its particle size distribution. Large crystals show poorer tabletability than fine crystals, further decreased by lubricant addition. The large crystals poor tabletability is due to their poor compactibility, in spite of high compressibility and plastic intrinsic deformability; in fact, in spite of the high densification tendency, the nature of the involved bonds is very weak. Nitrofurantoine samples were then mixed with Vivapurs in different proportions. Compression behaviour of binary mixes (tabletability and compressibility) was then evaluated according to diluents proportion in the mixes. The

  12. 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

  13. About the singular behavior of the ionic condensation of sodium chondroitin sulfate: Conductivity study in water and water dioxane mixture

    Science.gov (United States)

    M'halla, Jalel; Besbes, Rafik; Bouazzi, Ramzi; Boughammoura, Sondes

    2006-01-01

    sulfate in water ( bS = 5.72 Å). The addition of dioxane increases Lb, consequently, α is shifted from its Manning's value. In order to verify this dioxane effect, we have compared experimental equivalent conductibilities Λexp of sodium chondroitin sulfate in water ( no shift) and water-dioxane (60 wt%) mixture ( positive shift), to their theoretical values ΛM, ΛcthandΛsth corresponding, respectively, to the Manning, cylindrical and spherical models. This comparison allows also, to explain the conformation "chosen" by the polyion, in order to minimizing the friction effects (due to: viscosity; ionic and dielectric relaxations) and therefore, to optimize its mobility by the shift of its rate of ionic condensation α.

  14. (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.

  15. 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.

  16. Study on complex formation of dicyclohexyl-18-crown-6 with Mg2+, Ca2+ and Sr2+ in acetonitrile-water binary mixtures by conductometry

    OpenAIRE

    Mallika Sanyal

    2017-01-01

    The complexation reactions between Mg2+, Ca2+ and Sr2+ cations and dicyclohexyl-18-crown-6 (DCH 18C6) have been studied in acetonitrile–water binary mixtures at different temperatures by conductometry. The formation constants of the resulting 1:1 (M:L) complexes for all the three cations were determined from computer fitting of the molar conductance versus mole ratio data. The results show that the selectivity order of DCH 18C6 for the metal cations in the acetonitrile-water binary solvent at...

  17. 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

  18. 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

  19. 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.

  20. Characterization of Binary Ag-Cu Ion Mixtures in Zeolites: Their Reduction Products and Stability to Air Oxidation

    International Nuclear Information System (INIS)

    Fiddy, Steven; Petranovskii, Vitalii; Ogden, Steve; Iznaga, Inocente Rodriguez

    2007-01-01

    A series of Ag+-Cu2+ binary mixtures with different Ag/Cu ratios were supported on mordenite with different Si/Al ratios and were subsequently reduced under hydrogen in the temperature range 323K - 473K. Ag and Cu K-edge X-ray Absorption Spectroscopy (XAS) was conducted on these systems in-situ to monitor the reduction species formed and the kinetics of their reduction. In-situ XANES clearly demonstrates that the formation of silver particles is severely impeded by the addition of copper and that the copper is converted from Cu(II) to Cu(I) during reduction and completely reverts back to Cu(II) during cooling. There are no indications at any stage of the formation of bimetallic Ag-Cu clusters. Interestingly, the Ag/Cu ratio appears to have no influence of the reduction kinetics and reduction products formed with only the highest Si/Al ratio (MR = 128) investigated during this study having an influence on the reduction and stability to air oxidation

  1. 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.

  2. 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.

  3. Exergoeconomic analysis and optimization of an evaporator for a binary mixture of fluids in an organic Rankine cycle

    Science.gov (United States)

    Li, You-Rong; Du, Mei-Tang; Wang, Jian-Ning

    2012-12-01

    This paper focuses on the research of an evaporator with a binary mixture of organic working fluids in the organic Rankine cycle. Exergoeconomic analysis and performance optimization were performed based on the first and second laws of thermodynamics, and the exergoeconomic theory. The annual total cost per unit heat transfer rate was introduced as the objective function. In this model, the exergy loss cost caused by the heat transfer irreversibility and the capital cost were taken into account; however, the exergy loss due to the frictional pressure drops, heat dissipation to surroundings, and the flow imbalance were neglected. The variation laws of the annual total cost with respect to the number of transfer units and the temperature ratios were presented. Optimal design parameters that minimize the objective function had been obtained, and the effects of some important dimensionless parameters on the optimal performances had also been discussed for three types of evaporator flow arrangements. In addition, optimal design parameters of evaporators were compared with those of condensers.

  4. 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)

  5. Thermodynamic study of binary mixture of x1[C6mim][BF4] + x21-propanol: Measurements and molecular modeling

    International Nuclear Information System (INIS)

    Kermanpour, F.; Sharifi, T.

    2012-01-01

    Highlights: ► Densities and viscosities for binary mixture of {x 1 [C 6 mim][BF 4 ] + x 2 1-propanol} were measured at different temperatures. ► The excess molar functions were calculated from the obtained experimental data. ► These data were correlated with the Redlich–Kister equation and PFP model to obtain the coefficients and standard deviations. - Abstract: Densities, ρ, and viscosities, η, of pure 1-hexyl-3-methylimidazoliumtetrafluoro borate ([C 6 mim][BF 4 ]) and 1-propanol, and their binary mixture {x 1 [C 6 mim][BF 4 ] + x 2 1-propanol} were measured at atmospheric pressure and in the temperature range of 293.15–333.15 K. The excess molar volumes, V m E , thermal expansion coefficients, α, and their excess values, α E , isothermal coefficient of excess molar enthalpy, (∂H m E /∂p) T,x and excess viscosities, η E , were calculated from the experimental values of densities and viscosities. The excess molar volumes of the binary mixture are negative over the entire mole fraction range and increase with increasing temperature. Excess viscosities are negative over the entire mole fraction range of the mixture and decrease with increasing temperature. The obtained excess molar volumes and excess viscosities were correlated with the Redlich–Kister equation. The experimental results have also been used to examine the applicability of Prigogine–Flory–Patterson (PFP) theory in predicting the excess molar volume of the binary mixture. It is indicated that agreement between excess molar volumes calculated via PFP theory and the experimental results is good in all temperatures.

  6. Protic ionic liquids based on the dimeric and oligomeric anions: [(AcO)xH(x-1)]-.

    Science.gov (United States)

    Johansson, K M; Izgorodina, E I; Forsyth, M; MacFarlane, D R; Seddon, K R

    2008-05-28

    We describe a fluidity and conductivity study as a function of composition in N-methylpyrrolidine-acetic acid mixtures. The simple 1 : 1 acid-base mixture appears to form an ionic liquid, but its degree of ionicity is quite low and such liquids are better thought of as poorly dissociated mixtures of acid and base. The composition consisting of 3 moles acetic acid and 1 mole N-methylpyrrolidine is shown to form the highest ionicity mixture in this binary due to the presence of oligomeric anionic species [(AcO)(x)H(x-1)](-) stabilised by hydrogen bonds. These oligomeric species, being weaker bases than the acetate anion, shift the proton transfer equilibrium towards formation of ionic species, thus generating a higher degree of ionicity than is present at the 1 : 1 composition. A Walden plot analysis, thermogravimetric behaviour and proton NMR data, as well as ab initio calculations of the oligomeric species, all support this conclusion.

  7. A physicochemical investigation of ionic liquid mixtures† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c4sc02931c Click here for additional data file.

    Science.gov (United States)

    Clough, Matthew T.; Crick, Colin R.; Gräsvik, John; Niedermeyer, Heiko; Whitaker, Oliver P.

    2015-01-01

    Ionic liquids have earned the reputation of being ‘designer solvents’ due to the wide range of accessible properties and the degree of fine-tuning afforded by varying the constituent ions. Mixtures of ionic liquids offer the opportunity for further fine-tuning of properties. A broad selection of common ionic liquid cations and anions are employed to create a sample of binary and reciprocal binary ionic liquid mixtures, which are analysed and described in this paper. Physical properties such as the conductivity, viscosity, density and phase behaviour (glass transition temperatures) are examined. In addition, thermal stabilities of the mixtures are evaluated. The physical properties examined for these formulations are found to generally adhere remarkably closely to ideal mixing laws, with a few consistent exceptions, allowing for the facile prediction and control of properties of ionic liquid mixtures. PMID:29560198

  8. Computational solvation analysis of biomolecules in aqueous ionic liquid mixtures : From large flexible proteins to small rigid drugs.

    Science.gov (United States)

    Zeindlhofer, Veronika; Schröder, Christian

    2018-06-01

    Based on their tunable properties, ionic liquids attracted significant interest to replace conventional, organic solvents in biomolecular applications. Following a Gartner cycle, the expectations on this new class of solvents dropped after the initial hype due to the high viscosity, hydrolysis, and toxicity problems as well as their high cost. Since not all possible combinations of cations and anions can be tested experimentally, fundamental knowledge on the interaction of the ionic liquid ions with water and with biomolecules is mandatory to optimize the solvation behavior, the biodegradability, and the costs of the ionic liquid. Here, we report on current computational approaches to characterize the impact of the ionic liquid ions on the structure and dynamics of the biomolecule and its solvation layer to explore the full potential of ionic liquids.

  9. Thermodynamic properties of binary mixtures of tetrahydropyran with pyridine and isomeric picolines: Excess molar volumes, excess molar enthalpies and excess isentropic compressibilities

    International Nuclear Information System (INIS)

    Saini, Neeti; Jangra, Sunil K.; Yadav, J.S.; Sharma, Dimple; Sharma, V.K.

    2011-01-01

    Research highlights: → Densities, ρ and speeds of sound, u of tetrahydropyran (i) + pyridine or α-, β- or γ-picoline (j) binary mixtures at 298.15, 303.15 and 308.15 K and excess molar enthalpies, H E of the same set of mixtures at 308.15 K have been measured as a function of composition. → The observed densities and speeds of sound values have been employed to determine excess molar volumes, V E and excess isentropic compressibilities, κ S E . → Topology of the constituents of mixtures has been utilized (Graph theory) successfully to predict V E , H E and κ S E data of the investigated mixtures. → Thermodynamic data of the various mixtures have also been analyzed in terms of Prigogine-Flory-Patterson (PFP) theory. - Abstract: Densities, ρ and speeds of sound, u of tetrahydropyran (i) + pyridine or α-, β- or γ- picoline (j) binary mixtures at 298.15, 303.15 and 308.15 K and excess molar enthalpies, H E of the same set of mixtures at 308.15 K have been measured as a function of composition using an anton Parr vibrating-tube digital density and sound analyzer (model DSA 5000) and 2-drop micro-calorimeter, respectively. The resulting density and speed of sound data of the investigated mixtures have been utilized to predict excess molar volumes, V E and excess isentropic compressibilities, κ S E . The observed data have been analyzed in terms of (i) Graph theory; (ii) Prigogine-Flory-Patterson theory. It has been observed that V E , H E and κ S E data predicted by Graph theory compare well with their experimental values.

  10. 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.

  11. Excess parameters for binary mixtures of ethyl benzoate with 1-propanol, 1-butanol and 1-pentanol at T=303, 308, 313, 318, and 323 K

    International Nuclear Information System (INIS)

    Sreehari Sastry, S.; Babu, Shaik; Vishwam, T.; Parvateesam, K.; Sie Tiong, Ha.

    2013-01-01

    Various thermo–acoustic parameters, such as excess isentropic compressibility (K s E ), excess molar volume (V E ), excess free length (L f E ), excess Gibb's free energy (ΔG *E ), and excess Enthalpy (H E ), have been calculated from the experimentally determined data of density, viscosity and speed of sound for the binary mixtures of ethyl benzoate+1-propanol, or +1-butanol, or +1-pentanol over the entire range of composition at different temperatures (303, 308, 313, 318 and 323 K). The excess functions have been fitted to the Redlich–Kister type polynomial equation. The deviations for excess thermo–acoustic parameters have been explained on the basis of the intermolecular interactions present in these binary mixtures

  12. Excess parameters for binary mixtures of ethyl benzoate with 1-propanol, 1-butanol and 1-pentanol at T=303, 308, 313, 318, and 323 K

    Energy Technology Data Exchange (ETDEWEB)

    Sreehari Sastry, S., E-mail: sreeharisastry@yahoo.com [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar, Andhra Pradesh 522 510 (India); Babu, Shaik, E-mail: babu.computers@gmail.com [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar, Andhra Pradesh 522 510 (India); Vishwam, T., E-mail: vishwam@gitam.edu [Department of Engineering Physics, Gitam University, Hyderabad Campus, Andhra Pradesh 502 239 (India); Parvateesam, K., E-mail: kps27031966@gmail.com [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar, Andhra Pradesh 522 510 (India); Sie Tiong, Ha., E-mail: hast@utar.edu.my [Faculty of Science, Department of Chemical Science, Universiti Tunku Abdul Rahman, Jalan Universiti, Bandar Barat, 31900 Kampar, Perak (Malaysia)

    2013-07-01

    Various thermo–acoustic parameters, such as excess isentropic compressibility (K{sub s}{sup E}), excess molar volume (V{sup E}), excess free length (L{sub f}{sup E}), excess Gibb's free energy (ΔG{sup *E}), and excess Enthalpy (H{sup E}), have been calculated from the experimentally determined data of density, viscosity and speed of sound for the binary mixtures of ethyl benzoate+1-propanol, or +1-butanol, or +1-pentanol over the entire range of composition at different temperatures (303, 308, 313, 318 and 323 K). The excess functions have been fitted to the Redlich–Kister type polynomial equation. The deviations for excess thermo–acoustic parameters have been explained on the basis of the intermolecular interactions present in these binary mixtures.

  13. Evaluation of Vapor Pressure and Ultra-High Vacuum Tribological Properties of Ionic Liquids (2) Mixtures and Additives

    Science.gov (United States)

    Morales, Wilfredo; Koch, Victor R.; Street, Kenneth W., Jr.; Richard, Ryan M.

    2008-01-01

    Ionic liquids are salts, many of which are typically viscous fluids at room temperature. The fluids are characterized by negligible vapor pressures under ambient conditions. These properties have led us to study the effectiveness of ionic liquids containing both organic cations and anions for use as space lubricants. In the previous paper we have measured the vapor pressure and some tribological properties of two distinct ionic liquids under simulated space conditions. In this paper we will present vapor pressure measurements for two new ionic liquids and friction coefficient data for boundary lubrication conditions in a spiral orbit tribometer using stainless steel tribocouples. In addition we present the first tribological data on mixed ionic liquids and an ionic liquid additive. Post mortem infrared and Raman analysis of the balls and races indicates the major degradation pathway for these two organic ionic liquids is similar to those of other carbon based lubricants, i.e. deterioration of the organic structure into amorphous graphitic carbon. The coefficients of friction and lifetimes of these lubricants are comparable to or exceed these properties for several commonly used space oils.

  14. 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

  15. 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

  16. Excess molar volumes and deviation in viscosities of binary liquid mixtures of acrylic esters with hexane-1-ol at 303.15 and 313.15K

    OpenAIRE

    Patil, Sujata S.; Mirgane, Sunil R.; Arbad, Balasaheb R.

    2014-01-01

    Densities and viscosities for the four binary liquid mixtures of methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate with hexane-1-ol at temperatures 303.15 and 313.15 K and at atmospheric pressure were measured over the entire composition range. These values were used to calculate excess molar volumes and deviation in viscosities which were fitted to Redlich–Kister polynomial equation. Recently proposed Jouyban Acree model was also used to correlate the experimental value...

  17. Bubble points of the binary mixtures formed by ethylbenzene with some chloroaliphatics and substituted benzenes at p = 94.7 kPa

    Energy Technology Data Exchange (ETDEWEB)

    Vittal Prasad, T.E. [Properties Group, Chemical Engineering Laboratory, Indian Institute of Chemical Technology, Hyderabad 500 007 (India); Srinivas, M.Y. [Swami Ramananda Tirtha Institute of Science and Technology, Nalgonda 508 001 (India); Prasad, D.H.L. [Properties Group, Chemical Engineering Laboratory, Indian Institute of Chemical Technology, Hyderabad 500 007 (India)]. E-mail: dasika@iict.res.in

    2006-10-15

    Bubble points at a pressure of 94.7 kPa, over the entire composition range are measured for the binary mixtures formed by ethylbenzene with: 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, trichloroethylene, tetrachloroethylene, chlorobenzene, and nitrobenzene making use of a Swietoslawski type ebulliometer. The liquid phase composition versus temperature measurements are found to be well represented by the Wilson model.

  18. Surface Segregation in a Binary Mixture of Ionic Liquids: Comparison between High-Resolution RBS Measurements and Molecular Dynamics Simulations.

    Czech Academy of Sciences Publication Activity Database

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

    2016-01-01

    Roč. 145, č. 18 (2016), s. 184704 ISSN 0021-9606 R&D Projects: GA ČR(CZ) GA16-12291S Institutional support: RVO:67985858 Keywords : rutherford backscattering spectroscopy * vapor interface * tensions Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.965, year: 2016

  19. Inertial effects in three-dimensional spinodal decomposition of a symmetric binary fluid mixture: a lattice Boltzmann study

    Science.gov (United States)

    Kendon, Vivien M.; Cates, Michael E.; Pagonabarraga, Ignacio; Desplat, J.-C.; Bladon, Peter

    2001-08-01

    The late-stage demixing following spinodal decomposition of a three-dimensional symmetric binary fluid mixture is studied numerically, using a thermodynamically consistent lattice Boltzmann method. We combine results from simulations with different numerical parameters to obtain an unprecedented range of length and time scales when expressed in reduced physical units. (These are the length and time units derived from fluid density, viscosity, and interfacial tension.) Using eight large (2563) runs, the resulting composite graph of reduced domain size l against reduced time t covers 1 [less, similar] l [less, similar] 105, 10 [less, similar] t [less, similar] 108. Our data are consistent with the dynamical scaling hypothesis that l(t) is a universal scaling curve. We give the first detailed statistical analysis of fluid motion, rather than just domain evolution, in simulations of this kind, and introduce scaling plots for several quantities derived from the fluid velocity and velocity gradient fields. Using the conventional definition of Reynolds number for this problem, Re[phi] = ldl/dt, we attain values approaching 350. At Re[phi] [greater, similar] 100 (which requires t [greater, similar] 106) we find clear evidence of Furukawa's inertial scaling (l [similar] t2/3), although the crossover from the viscous regime (l [similar] t) is both broad and late (102 [less, similar] t [less, similar] 106). Though it cannot be ruled out, we find no indication that Re[phi] is self-limiting (l [similar] t1/2) at late times, as recently proposed by Grant & Elder. Detailed study of the velocity fields confirms that, for our most inertial runs, the RMS ratio of nonlinear to viscous terms in the Navier Stokes equation, R2, is of order 10, with the fluid mixture showing incipient turbulent characteristics. However, we cannot go far enough into the inertial regime to obtain a clear length separation of domain size, Taylor microscale, and Kolmogorov scale, as would be needed to test a

  20. Experimental determination of the (vapor + liquid) equilibrium data of binary mixtures of fatty acids by differential scanning calorimetry

    International Nuclear Information System (INIS)

    Matricarde Falleiro, Rafael M.; Meirelles, Antonio J.A.; Kraehenbuehl, Maria A.

    2010-01-01

    (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 (φ = 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 14:0 ) + palmitic acid (C 16:0 ), myristic acid (C 14:0 ) + stearic acid (C 18:0 ), and palmitic acid (C 16:0 ) + stearic acid (C 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 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.