WorldWideScience

Sample records for binary gas mixtures

  1. A Lattice Boltzmann model for diffusion of binary gas mixtures

    OpenAIRE

    Bennett, Sam

    2010-01-01

    This thesis describes the development of a Lattice Boltzmann (LB) model for a binary gas mixture. Specifically, channel flow driven by a density gradient with diffusion slip occurring at the wall is studied in depth. The first part of this thesis sets the foundation for the multi-component model used in the subsequent chapters. Commonly used single component LB methods use a non-physical equation of state, in which the relationship between pressure and density varies according to the sca...

  2. Asymptotic-preserving Boltzmann model equations for binary gas mixture

    Science.gov (United States)

    Liu, Sha; Liang, Yihua

    2016-02-01

    An improved system of Boltzmann model equations is developed for binary gas mixture. This system of model equations has a complete asymptotic preserving property that can strictly recover the Navier-Stokes equations in the continuum limit with the correct constitutive relations and the correct viscosity, thermal conduction, diffusion, and thermal diffusion coefficients. In this equation system, the self- and cross-collision terms in Boltzmann equations are replaced by single relaxation terms. In monocomponent case, this system of equations can be reduced to the commonly used Shakhov equation. The conservation property and the H theorem which are important for model equations are also satisfied by this system of model equations.

  3. Dissipation process of binary gas mixtures in thermally relativistic flow

    Science.gov (United States)

    Yano, Ryosuke

    2016-04-01

    In this paper, dissipation process of binary gas mixtures in thermally relativistic flows is discussed with focus on characteristics of diffusion flux. As an analytical object, we consider the relativistic rarefied-shock layer around a triangular prism. Numerical results for the diffusion flux are compared with the Navier–Stokes–Fourier (NSF) order approximation of the diffusion flux, which is calculated using the diffusion and thermal-diffusion coefficients by Kox et al (1976 Physica A 84 165–74). In the case of uniform flow with small Lorentz contraction, the diffusion flux, which is obtained by calculating the relativistic Boltzmann equation, is roughly approximated by the NSF order approximation inside the shock wave, whereas the diffusion flux in the vicinity of a wall is markedly different from the NSF order approximation. The magnitude of the diffusion flux, which is obtained by calculating the relativistic Boltzmann equation, is similar to that of the NSF order approximation inside the shock wave, unlike the pressure deviator, dynamic pressure and heat flux, even when the Lorentz contraction in the uniform flow becomes large, because the diffusion flux does not depend on the generic Knudsen number from its definition in Eckart’s frame. Finally, the author concludes that for accuracy diffusion flux must be calculated using the particle four-flow and averaged four velocity, which are formulated using the four velocity defined by each species of hard spherical particles.

  4. Dissipation process of binary mixture gas in thermally relativistic flow

    CERN Document Server

    Yano, Ryosuke

    2016-01-01

    In this paper, we discuss dissipation process of the binary mixture gas in the thermally relativistic flow \\textcolor{red}{by focusing on the characteristics of the diffusion flux}. As an analytical object, we consider the relativistic rarefied-shock layer problem around the triangle prism. Numerical results of the diffusion flux are compared with the Navier-Stokes-Fourier (NSF) order approximation of the diffusion flux, which is calculated using the diffusion and thermal-diffusion coefficients by Kox \\textit{et al}. [Physica A, 84, 1, pp.165-174 (1976)]. In the case of the uniform flow with the small Lorentz contraction, the diffusion flux, which is obtained by calculating the relativistic Boltzmann equation, is roughly approximated by the NSF order approximation inside the shock wave, whereas the diffusion flux in the vicinity of the wall is markedly different from the NSF order approximation. The magnitude of the diffusion flux, which is obtained by calculating the relativistic Boltzmann equation, is simil...

  5. Rayleigh-Brillouin Scattering in Binary Gas Mixtures

    CERN Document Server

    Gu, Ziyu; van de Water, Willem; Marques, Wilson

    2015-01-01

    Precise measurements are performed on spectral lineshapes of spontaneous Rayleigh-Brillouin scattering in mixtures of the noble gases Ar and Kr, with He. Admixture of a light He atomic fraction results in marked changes of the spectra, although in all experiments He is merely a spectator atom: it affects the relaxation of density fluctuations of the heavy constituent, but its contribution to the scattered light intensity is negligibly small. The results are compared to a theory for the spectral lineshape without adjustable parameters, yielding excellent agreement for the case of binary mono-atomic gases, signifying a step towards modeling and understanding of light scattering in more complex molecular media.

  6. Sub-shock formation in Grad 10-moment equations for a binary gas mixture

    Science.gov (United States)

    Bisi, Marzia; Conforto, Fiammetta; Martalò, Giorgio

    2016-09-01

    The shock structure problem for Grad 10-moment equations for an inert binary mixture is investigated: necessary conditions for the formation of sub-shocks in fields of only one gas or of both components are rigorously obtained, and a detailed comparison with the shock-wave structure of its principal sub-system (deduced assuming vanishing viscous stress tensors) and of the equilibrium Euler sub-system is performed. Some numerical simulations for a mixture of argon and helium are presented.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    Richard Bates

    2014-06-01

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

  9. 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)

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

    CERN Document Server

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

    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 CO2-He, CO2-Ar, CO2-N2 and CO2-O2 binary mixtures by the developed cycle code. CO2-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-CO2 cycle was decrease in minimum cycle temperature and changes in minimum pressure and working fluids. Through the simulation, the CO2-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 CO2-He binary mixture, the cycle efficiencies of CO2-Ar, CO2-N2, and CO2-O2 binary mixtures decreased compared to the pure S-CO2 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 CO2-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 CO2-He cycle is not a supercritical Brayton cycle. For the option of CO2-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 CO2-Xe mixture cycle is expected to increase by 1.28 %

  12. Separation Analysis in a High-Speed Rotating Cylinder for a Binary Gas Mixture

    Science.gov (United States)

    Pradhan, Sahadev; Kumaran, Viswanathan

    2015-11-01

    The solutions of the species balance equations linked with the generalized Onsager model for the secondary gas flow in a high-speed rotating cylinder are compared with the direct simulation Monte Carlo (DSMC) simulations for a binary gas mixture. The concentration fields are obtained three different types of driving mechanism. These are: (a) wall thermal forcing, (b) inflow/outflow of gas along the axis, and (c) momentum source/sink inside the flow domain, for the stratification parameter (A) in the range (0.707- 3.535), and Reynolds number (Re) in the range (102 - 106 with aspect ratio (length / diameter) = 2, 4, 8. Two different types of cases have been considered, (a) no mass difference (ɛa = (2 Δm/(m1 + m2)) = 0), and (b) with mass difference (ɛa = 0.2 and 0.5) while calculating the secondary flow field in the analytical solution. Here, the stratification prameter A = √((mavΩ2 R2)/(2 kB T)), and the Reynolds number Re = ρw Ω R2)/ μ, where m is the molecular mass, Ω and R are the angular velocity and radius of the cylinder, ρw is the wall density, μ is the gas viscosity and T is the gas temperature. The comparison between numerical and analytical solution reveals that the boundary conditions in the numerical simulations and analytical model have to be matched with care. The commonly used ``diffuse reflection'' boundary conditions at the solid walls in DSMC simulations result in a non-zero slip velocity as well as a ``temperature slip'' (gas temperature at the wall is different from wall temperature).

  13. 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......, alcohols and glycols) are considered, the importance of cross-association is investigated. The cross-association is accounted for either via combining rules or using a cross-solvation energy obtained from experimental spectroscopic or calorimetric data or from ab initio calculations. In both cases two...

  14. Density functional theory of gas-liquid phase separation in dilute binary mixtures.

    Science.gov (United States)

    Okamoto, Ryuichi; Onuki, Akira

    2016-06-22

    We examine statics and dynamics of phase-separated states of dilute binary mixtures using density functional theory. In our systems, the difference of the solvation chemical potential between liquid and gas [Formula: see text] (the Gibbs energy of transfer) is considerably larger than the thermal energy [Formula: see text] for each solute particle and the attractive interaction among the solute particles is weaker than that among the solvent particles. In these conditions, the saturated vapor pressure increases by [Formula: see text], where [Formula: see text] is the solute density added in liquid. For [Formula: see text], phase separation is induced at low solute densities in liquid and the new phase remains in gaseous states, even when the liquid pressure is outside the coexistence curve of the solvent. This explains the widely observed formation of stable nanobubbles in ambient water with a dissolved gas. We calculate the density and stress profiles across planar and spherical interfaces, where the surface tension decreases with increasing interfacial solute adsorption. We realize stable solute-rich bubbles with radius about 30 nm, which minimize the free energy functional. We then study dynamics around such a bubble after a decompression of the surrounding liquid, where the bubble undergoes a damped oscillation. In addition, we present some exact and approximate expressions for the surface tension and the interfacial stress tensor.

  15. Low-pressure equilibrium binary argon-methane gas mixture adsorption on exfoliated graphite: Experiments and simulations

    Science.gov (United States)

    Albesa, Alberto; Russell, Brice; Vicente, José Luis; Rafti, Matías

    2016-04-01

    Adsorption equilibrium measurements of pure methane, pure argon, and binary mixtures over exfoliated graphite were carried for different initial compositions, temperatures, and total pressures in the range of 0.1-1.5 Torr using the volumetric static method. Diagrams for gas and adsorbed phase compositions were constructed for the conditions explored, and isosteric heats of adsorption were calculated. Experimental results were compared with predictions obtained with Monte Carlo simulations and using the Ideal Adsorbed Solution Theory (IAST).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-01-23

    This patent describes a capacitive energy storage system. It comprises: a diffuse-discharge switch; a gas mixture in the diffuse-discharge switch comprising a mixture of He, Ne and Ar in combination with a second compound selected from the group consisting of (CF{sub 3}){sub 2}O, CF{sub 4}, BF{sub 3}, GeF{sub 4}, WF{sub 6}, SiF{sub 4}, in combination with a compound selected from the group consisting of TMPD, TMBI, TMAE, TMAB, triethylamine, methylaniline, diethylamine, aniline, Co-ocene, Ch-ocene, Ni-ocene and Fe-ocene; and means for selectively activating the gas mixture to an electrical conductive state.

  17. Concentration measurement systems with stable solutions for binary gas mixtures using two flowmeters

    Science.gov (United States)

    Youn, Chongho; Kawashima, Kenji; Kagawa, Toshiharu

    2011-06-01

    The previously proposed gas concentration measurement system (Yamazaki et al 2007 Meas. Sci. Technol. 18 2762-8) shows a considerable error for some combinations of gases. The error increases when the system of equations determining mole fractions becomes a mathematically ill-conditioned system. Because the parameters of the equations reflect the material properties of the gases, the current paper considers flowmeters whose flow rate indication does not involve any gas property. This paper firstly illustrates the ill condition for the combination of venturi meter and laminar flowmeters. The paper then discusses the simultaneous measurement of flow rate and mole fractions by flowmeter combinations: an ultrasonic flowmeter and a venturi meter, an ultrasonic flowmeter and a laminar flowmeter. Experiments are conducted for a mixture of argon and air. When a venturi meter and a laminar flowmeter are used, the equations to evaluate the gas mixture ratio become an ill-conditioned system, and hence the evaluated mixture ratio shows a considerable error. On the other hand, the combination of an ultrasonic flowmeter and a laminar flowmeter detects the gas mixture ratio with proper accuracy.

  18. FAST TRACK COMMUNICATION: Effects of reducing interferers in a binary gas mixture on NO2 gas adsorption using carbon nanotube networked films based chemiresistors

    Science.gov (United States)

    Penza, M.; Rossi, R.; Alvisi, M.; Signore, M. A.; Serra, E.

    2009-04-01

    Analysis of binary gas mixtures using chemiresistors based on carbon nanotubes (CNTs) networked films has been performed for chemical detection up to a sub-ppm level. The effects of individual interfering analytes of reducing H2S and NH3 gases on oxidizing NO2 gas adsorption in CNTs tangled films are considered. The CNTs are grown by plasma-enhanced chemical vapour deposition technology onto inexpensive alumina substrates, coated by cobalt nanosized catalyst. Charge transfer between adsorbed gas molecules and CNT networks, characterized by a semiconducting p-type electrical transport, occurs depending on opposite trend in the sensor response to the electron-donating interfering gases (H2S, NH3) and target electron-withdrawing NO2 gas causing a compensation of the charge transport, upon given working conditions. This compensated exchange of electrical charge affects the limit of detection of the targeted NO2 gas sensed in different real-world binary gas mixtures of reducing interferers of H2S and NH3. In addition, the functionalization of the CNT films with Au nanoclusters enhanced the sensitivity of the chemiresistor and tuned the compensation of electrical charge crossover in the selected binary oxido-reducing mixtures.

  19. Marangoni Convection in Binary Mixtures

    CERN Document Server

    Zhang, J; Oron, A; Behringer, Robert P.; Oron, Alexander; Zhang, Jie

    2006-01-01

    Marangoni instabilities in binary mixtures are different from those in pure liquids. In contrast to a large amount of experimental work on Marangoni convection in pure liquids, such experiments in binary mixtures are not available in the literature, to our knowledge. Using binary mixtures of sodium chloride/water, we have systematically investigated the pattern formation for a set of substrate temperatures and solute concentrations in an open system. The flow patterns evolve with time, driven by surface-tension fluctuations due to evaporation and the Soret effect, while the air-liquid interface does not deform. A shadowgraph method is used to follow the pattern formation in time. The patterns are mainly composed of polygons and rolls. The mean pattern size first decreases slightly, and then gradually increases during the evolution. Evaporation affects the pattern formation mainly at the early stage and the local evaporation rate tends to become spatially uniform at the film surface. The Soret effect becomes i...

  20. Development of a Binary Mixture Gas Composition Instrument for Use in a Confined High Temperature Environment

    Science.gov (United States)

    Cadell, Seth R.

    , or used to measure the purity of the coolant itself. This work details the efforts conducted to develop such an instrument. While the concept of designing a capacitance sensor to measure a gas mixture is not unique, the application of using a capacitance sensor within a nuclear reactor is a new application. This application requires the development of an instrument that will survive a high temperature nuclear reactor environment and operate at a sensitivity not found in current applications. To prove this technique, instrument prototypes were built and tested in confined environments and at high temperatures. This work discusses the proof of concept testing and outlines an application in the High Temperature Test Facility to increase the operational understanding of the instrument. This work is the first step toward the ultimate outcome of this work, which is to provide a new tool to the gas reactor community allowing real-time measurements of coolant properties within the core.

  1. Estimation of the minimum Prandtl number for binary gas mixtures formed with light helium and certain heavier gases: Application to thermoacoustic refrigerators

    International Nuclear Information System (INIS)

    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 (N2), oxygen (O2), xenon (Xe), carbon dioxide (CO2), methane (CH4), tetrafluoromethane or carbon tetrafluoride (CF4) and sulfur hexafluoride (SF6). The three thermophysical properties forming the Prandtl number of binary gas mixtures Prmix are heat capacity at constant pressure Cp,mix (thermodynamic property), viscosity ηmix (transport property) and thermal conductivity λmix (transport property), which in general depend on temperature T and molar gas composition w. The precise formulas for the calculation of the trio Cp,mix, ηmix, and λmix are gathered from various dependable sources. When the set of computed Prmix values for the seven binary gas mixtures He + N2, He + O2, He + Xe, He + CO2, He + CH4, He + CF4, He + SF6 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 Prmix(w) curves exhibited distinctive concave shapes. In the curves format, all Prmix(w) curves initiate with Pr ∼ 0.7 at w = 0 (associated with light primary He). Forthwith, each Prmix(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 Prmix,min = 0.12 at the optimal molar gas composition wopt = 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 refrigerators

  2. Modified Sonine approximation for granular binary mixtures

    OpenAIRE

    Garzó, Vicente; Reyes, Francisco Vega; Montanero, José María

    2008-01-01

    We evaluate in this work the hydrodynamic transport coefficients of a granular binary mixture in $d$ dimensions. In order to eliminate the observed disagreement (for strong dissipation) between computer simulations and previously calculated theoretical transport coefficients for a monocomponent gas, we obtain explicit expressions of the seven Navier-Stokes transport coefficients with the use of a new Sonine approach in the Chapman-Enskog theory. Our new approach consists in replacing, where a...

  3. Thermodynamics and kinetics of binary nucleation in ideal-gas mixtures

    CERN Document Server

    Alekseechkin, Nikolay V

    2015-01-01

    The nonisothermal single-component theory of droplet nucleation (Alekseechkin, 2014) is extended to binary case; the droplet volume V, composition x, and temperature T are the variables of the theory. An approach based on macroscopic kinetics (in contrast to the standard microscopic model of nucleation operating with the probabilities of monomer attachment and detachment) is developed for the droplet evolution and results in the derived droplet motion equations in the space (V,x,T) - equations for V_dot, x_dot, and T_dot. The work W(V,x,T) of the droplet formation is calculated; it 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 is shown to be the first law of thermodynamics for the droplet, which is a consequence of Onsagers reciprocal relations an...

  4. Binary mixtures of chiral gases

    CERN Document Server

    Presilla, Carlo

    2015-01-01

    A possible solution of the well known paradox of chiral molecules is based on the idea of spontaneous symmetry breaking. At low pressure the molecules are delocalized between the two minima of a given molecular potential while at higher pressure they become localized in one minimum due to the intermolecular dipole-dipole interactions. Evidence for such a phase transition is provided by measurements of the inversion spectrum of ammonia and deuterated ammonia at different pressures. In particular, at pressure greater than a critical value no inversion line is observed. These data are well accounted for by a model previously developed and recently extended to mixtures. In the present paper, we discuss the variation of the critical pressure in binary mixtures as a function of the fractions of the constituents.

  5. Separation of a binary mixture with a large mass difference between the components in a gas centrifuge

    OpenAIRE

    Abramov, Y. V.; Tokmantsev, V. I.

    2013-01-01

    The separation of a binary gaseous mixture of uranium hexafluoride 238UF6 with different light components in a high-speed centrifuge, intended for separating heavy isotopes, is examined. The mass of the light impurities is varied in the range M 1 = 0.02-0.349 kg/mole. It is shown that as the impurity mass decreases the structure of the flow fields in the centrifuge rotor changes considerably. If in the case of a mixture of heavy isotopes convective transport has a determining effect on the co...

  6. Development of a new gas sensor for binary mixtures based on the permselectivity of polymeric membranes. Application to carbon dioxide/methane and carbon dioxide/helium mixtures

    OpenAIRE

    Rosa Rego; Nídia Caetano; Adélio Mendes

    2004-01-01

    Membrane-based gas sensors were developed and used for determining the composition on bi-component mixtures in the 0100% range, such as oxygen/nitrogen and carbon dioxide/methane (biogas). These sensors are low cost and are aimed at a low/medium precision market.The paper describes the use of this sensor for two gas mixtures: carbon dioxide/methane and carbon dioxide/helium. The membranes used are poly(dimethylsiloxane) (PDMS) and Teflon-AF hollow fibers. The response curves for both sensors ...

  7. PARTICLE SEGREGATION IN FLUIDIZED BINARY-MIXTURES

    NARCIS (Netherlands)

    HOFFMANN, AC; JANSSEN, LPBM

    1993-01-01

    The particle segregation in fluidised beds consisting of different types of binary mixtures is shown to be governed by the same particle transport processes. The segregation behaviour of both ''different-density mixtures'' and ''equal-density mixtures'', two types of system which until now largely h

  8. Component fractionation of temporal evolution in adsorption-desorption for binary gas mixtures on coals from Haishiwan Coal Mine

    Institute of Scientific and Technical Information of China (English)

    Wang Liguo; Cheng Yuanping; Li Wei; Lu Shouqing; Xu Chao

    2013-01-01

    Adsorption-desorption experiments on CO2-CH4 gas mixtures with varying compositions have been conducted to study the fractionation characteristics of CO2-CH4 on Haishiwan coal samples.These were carried out at constant temperature but different equilibrium pressure conditions.Based on these experimental results,the temporal evolution of component fractionation in the field was investigated.The results show that the CO2 concentration in the adsorbed phase is always greater than that in the original gas mixture during the desorption process,while CH4 shows the opposite characteristics.This has confirmed that CO2,with a greater adsorption ability has a predominant position in the competition with CH4 under different pressures.Where gas drainage is employed,the ratio of CO2 to CH4 varies with time and space in floor roadways used for gas drainage,and in the ventilation air in Nos.1 and 2 coal seams,which is consistent with laboratory results.

  9. 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...

  10. VUV emission spectra from binary rare gas mixtures near the resonance lines of Xe I and Kr I

    CERN Document Server

    Morozov, A; Gerasimov, G; Arnesen, A; Hallin, R

    2003-01-01

    Emission spectra of Xe-X (X = He, Ne, Ar and Kr) and of Kr-Y (Y = He, Ne and Ar) mixtures with low concentrations of the heavier gases (0.1-1%) and moderate total pressures (50-200 hPa) have been recorded near each of the two resonance lines of Xe and Kr in DC glow capillary discharges. The recorded intense emissions have narrow spectral profiles with FWHM of about 0.1 nm. The profiles are very similar in shape to profiles of known high resolution absorption spectra recorded at comparable gas pressures. A tentative identification of the emission structures is given, which involves transitions in heteronuclear molecules and quasimolecules between weakly-bound states.

  11. Spinodal decomposition of chemically reactive binary mixtures

    Science.gov (United States)

    Lamorgese, A.; Mauri, R.

    2016-08-01

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

  12. Spinodal decomposition of chemically reactive binary mixtures.

    Science.gov (United States)

    Lamorgese, A; Mauri, R

    2016-08-01

    We simulate the influence of a reversible isomerization reaction on the phase segregation process occurring after spinodal decomposition of a deeply quenched regular binary mixture, restricting attention to systems wherein material transport occurs solely by diffusion. Our theoretical approach follows a diffuse-interface model of partially miscible binary mixtures wherein the coupling between reaction and diffusion is addressed within the frame of nonequilibrium thermodynamics, leading to a linear dependence of the reaction rate on the chemical affinity. Ultimately, the rate for an elementary reaction depends on the local part of the chemical potential difference since reaction is an inherently local phenomenon. Based on two-dimensional simulation results, we express the competition between segregation and reaction as a function of the Damköhler number. For a phase-separating mixture with components having different physical properties, a skewed phase diagram leads, at large times, to a system converging to a single-phase equilibrium state, corresponding to the absolute minimum of the Gibbs free energy. This conclusion continues to hold for the critical phase separation of an ideally perfectly symmetric binary mixture, where the choice of final equilibrium state at large times depends on the initial mean concentration being slightly larger or less than the critical concentration. PMID:27627358

  13. Hydrodynamic limit Of a binary mixture Of rigid spheres

    OpenAIRE

    CHOE, HI JUN; Zhou, Shulin

    2015-01-01

    In this paper, we study the hydrodynamic limit of a binary mixture of rigid spheres. When Knudsen numbers of two different species are equal and go to zero, we show formally that the hydrodynamic variables satisfy the compressible Euler and Navier-Stokes equations. Like single species gas, we develop Enskog-Chapman theory up to the second order. It turns out that the macro velocities corresponding to the different spheres are equal and the ratio of the temperatures is the...

  14. Processes assessment in binary mixture plant

    Directory of Open Access Journals (Sweden)

    N. Shankar Ganesh, T. Srinivas

    2013-01-01

    Full Text Available Binary fluid system has an efficient system of heat recovery compared to a single fluid system due to a better temperature match between hot and cold fluids. There are many applications with binary fluid system i.e. Kalina power generation, vapor absorption refrigeration, combined power and cooling etc. Due to involvement of three properties (pressure, temperature and concentration in the processes evaluation, the solution is complicated compared to a pure substance. The current work simplifies this complex nature of solution and analyzes the basic processes to understand the processes behavior in power generation as well as cooling plants. Kalina power plant consists of regenerator, heat recovery vapor generator, condenser, mixture, separator, turbine, pump and throttling device. In addition to some of these components, the cooling plant consists of absorber which is similar in operation of condenser. The amount of vapor at the separator decreases with an increase in its pressure and temperature.

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

    International Nuclear Information System (INIS)

    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.

  16. 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.

  17. Formation of Nanoparticles in binary polymer mixtures

    Science.gov (United States)

    Cai, Tong; Lu, Xihua; Hu, Zhibin

    2000-10-01

    Formation of Nanoparticles in binary polymer mixtures Tong CAI, Xihua LU, and Zhibin HU Department of Physics, Denton, TX76203 The nanoparticles of hydrorypropyl cellulose (HPC)-polyacrylic acid (PAA) complex have been studied using light scattering method. The formation of the nanoparticles results from the hydrogen-bonding interaction between HPC and PAA. The particle size and size distribution, characterized by dynamic light scattering, depend on the HPC concentration, PAA concentration and reactive temperature. Because HPC and PAA have been approved for use inside human body by FDA, the nanoparticle obtained in this study could be used as drug carriers for controlled release.

  18. Dynamic thermodiffusion model for binary liquid mixtures.

    Science.gov (United States)

    Eslamian, Morteza; Saghir, M Ziad

    2009-07-01

    Following the nonequilibrium thermodynamics approach, we develop a dynamic model to emulate thermo-diffusion process and propose expressions for estimating the thermal diffusion factor in binary nonassociating liquid mixtures. Here, we correlate the net heat of transport in thermodiffusion with parameters, such as the mixture temperature and pressure, the size and shape of the molecules, and mobility of the components, because the molecules have to become activated before they can move. Based on this interpretation, the net heat of transport of each component can be somehow related to the viscosity and the activation energy of viscous flow of the same component defined in Eyring's reaction-rate theory [S. Glasstone, K. J. Laidler, and H. Eyring, (McGraw-Hill, New York, 1941)]. This modeling approach is different from that of Haase and Kempers, in which thermodiffusion is considered as a function of the thermostatic properties of the mixture such as enthalpy. In simulating thermodiffusion, by correlating the net heat of transport with the activation energy of viscous flow, effects of the above mentioned parameters are accounted for, to some extent of course. The model developed here along with Haase-Kempers and Drickamer-Firoozabadi models linked with the Peng-Robinson equation of sate are evaluated against the experimental data for several recent nonassociating binary mixtures at various temperatures, pressures, and concentrations. Although the model prediction is still not perfect, the model is simple and easy to use, physically justified, and predicts the experimental data very good and much better than the existing models. PMID:19658691

  19. Dynamic thermodiffusion model for binary liquid mixtures

    Science.gov (United States)

    Eslamian, Morteza; Saghir, M. Ziad

    2009-07-01

    Following the nonequilibrium thermodynamics approach, we develop a dynamic model to emulate thermo-diffusion process and propose expressions for estimating the thermal diffusion factor in binary nonassociating liquid mixtures. Here, we correlate the net heat of transport in thermodiffusion with parameters, such as the mixture temperature and pressure, the size and shape of the molecules, and mobility of the components, because the molecules have to become activated before they can move. Based on this interpretation, the net heat of transport of each component can be somehow related to the viscosity and the activation energy of viscous flow of the same component defined in Eyring’s reaction-rate theory [S. Glasstone, K. J. Laidler, and H. Eyring, The Theory of Rate Processes: The Kinetics of Chemical Reactions, Viscosity, Diffusion and Electrochemical Phenomena (McGraw-Hill, New York, 1941)]. This modeling approach is different from that of Haase and Kempers, in which thermodiffusion is considered as a function of the thermostatic properties of the mixture such as enthalpy. In simulating thermodiffusion, by correlating the net heat of transport with the activation energy of viscous flow, effects of the above mentioned parameters are accounted for, to some extent of course. The model developed here along with Haase-Kempers and Drickamer-Firoozabadi models linked with the Peng-Robinson equation of sate are evaluated against the experimental data for several recent nonassociating binary mixtures at various temperatures, pressures, and concentrations. Although the model prediction is still not perfect, the model is simple and easy to use, physically justified, and predicts the experimental data very good and much better than the existing models.

  20. Thermodynamics of binary gas adsorption in nanopores.

    Science.gov (United States)

    Dutta, Sujeet; Lefort, Ronan; Morineau, Denis; Mhanna, Ramona; Merdrignac-Conanec, Odile; Saint-Jalmes, Arnaud; Leclercq, Théo

    2016-09-21

    MCM-41 nanoporous silicas show a very high selectivity for monoalcohols over aprotic molecules during adsorption of a binary mixture in the gas phase. We present here an original use of gravimetric vapour sorption isotherms to characterize the role played by the alcohol hydrogen-bonding network in the adsorption process. Beyond simple selectivity, vapour sorption isotherms measured for various compositions help to completely unravel at the molecular level the step by step adsorption mechanism of the binary system in the nanoporous solid, from the first monolayers to the complete liquid condensation. PMID:27532892

  1. Binary MEMS gas sensors

    International Nuclear Information System (INIS)

    A novel sensing mechanism for electrostatic MEMS that employs static bifurcation-based sensing and binary detection is demonstrated. It is implemented as an ethanol vapour sensor that exploits the static pull-in bifurcation. Sensor detection of 5 ppm of ethanol vapour in dry nitrogen, equivalent to a detectable mass of 165 pg, is experimentally demonstrated. Sensor robustness to external disturbances is also demonstrated. A closed-form expression for the sensitivity of statically detected electrostatic MEMS sensors is derived. It is shown that the sensitivity of static bifurcation-based binary electrostatic MEMS sensors represents an upper bound on the sensitivity of static detection for given sensor dimensions and material properties. (paper)

  2. Preparation and Characterization of Binary Mixture of Efavirenz and Nicotinamide

    Directory of Open Access Journals (Sweden)

    Erizal Zaini

    2015-12-01

    Full Text Available The purpose of this study was to prepare and characterize the binary mixture of efavirenz and nicotinamide. The binary mixture of efavirenz and nicotinamide (in equimolar ratio was prepared by solid state grinding and solvent dropped grinding. Characterizations were conducted by powder X-ray diffraction (PXRD, differential thermal analysis (DTA and scanning electron microscopy (SEM analysis. Interaction of efavirenz and nicotinamide in liquid states was studied by phase solubility profile. The dissolution rate studies was conducted by using USP type II apparatus in distilled water with 0.5 % sodium lauryl sulfate. Efavirenz dissolved was determined by high performance liquid chromatography (HPLC with Acetonitrile and acetic acid 1 % as mobile phase. The diffracgram of powder X-Ray analysis showed that both efavirenz and nicotinamide are highly crystalline, and equimolar binary mixtures showed a similar diffraction peaks. Thermal analysis result showed that binary mixture of efavirenz and nicotinamide form a simple eutectic mixture with the eutectic temperature (tE was 92.7 °C. The SEM analysis depicted that efavirenz and nicotinamide are polyhedral shaped particles, while binary mixture showed a homogenous aggregates of fine needle shaped particles. Phase solubility profile of the binary mixture indicated formation of a soluble complex between efavirenz and nicotinamide in 1:1 molar. The dissolution rate of the binary mixtures were significantly higher compared to the intact efavirenz.

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

    OpenAIRE

    Changquan Calvin Sun

    2016-01-01

    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. Eac...

  4. Importance of Molecular Structure on the Thermophoresis of Binary Mixtures.

    Science.gov (United States)

    Kumar, Pardeep; Goswami, Debabrata

    2014-12-26

    Using thermal lens spectroscopy, we study the role of molecular structural isomers of butanol on the thermophoresis (or Soret effect) of binary mixtures of methanol in butanol. In this study, we show that the thermal lens signal due to the Soret effect changes its sign for all the different concentrations of binary mixtures of butanol with methanol except for the one containing tertiary-butanol. The magnitude and sign of the Soret coefficients strongly depend on the molecular structure of the isomers of butanol in the binary mixture with methanol. This isomerization dependence is in stark contrast to the expected mass dependence of the Soret effect.

  5. Nucleation in a Sheared Liquid Binary Mixture.

    Science.gov (United States)

    Min, Kyung-Yang

    When a binary liquid mixture of lutidine plus water (LW) is quenched to a temperature T and is exposed to a continuous shear rate S, the result is a steady-state droplet distribution. This steady state can be probed by measuring the unscattered intensity I_{f}, or the scattered intensity I_{s}, as a function of delta T and S. In the experiments described here, S is fixed and delta T is varied in a step-wise fashion. The absence of hysteresis was probed in two separate experiments: First, I_{f} was measured as a function of S for a given delta T. Next, I_{f} was measured as a function of delta T for a given S. In either case, the hysteresis associated with the shear-free nucleation is absent. In addition, a flow-history dependent hysteresis was studied. In the 2-dimensional parameter space consisting of S and delta T, the onset of nucleation uniquely determines a cloud point line. A plot of the cloud point line exhibits two segments of different slopes with a cross-over near the temperature corresponding to the Becker-Doring limit. The classical picture of a free energy barrier was reformulated to explain this cross-over behavior. Next, photon correlation spectroscopy was used to study the dependence of the transient nucleation behavior on the initial states. A unique feature of this study is that this initial state can be conveniently adjusted by varying the shear rate S to which the mixture is initially exposed. The shear is then turned off, and the number density N(t), as well as the mean radius of the growing droplets, is monitored as a function of time. It was possible to measure the droplet density at a very early stage of phase separation where the nucleation rate J was close to zero. The measurement reveals that N(t) depends critically on the initial state of the metastable system. When the shear is large enough to rupture the droplets as small as the critical size, N(t) increases very slowly. Measurements of the nucleation rates vs. the square of the

  6. Preparation and Characterization of Binary Mixture of Efavirenz and Nicotinamide

    OpenAIRE

    Erizal Zaini; Fitri Rachmaini; Fithriani Armin; Lili Fitriani

    2015-01-01

    The purpose of this study was to prepare and characterize the binary mixture of efavirenz and nicotinamide. The binary mixture of efavirenz and nicotinamide (in equimolar ratio) was prepared by solid state grinding and solvent dropped grinding. Characterizations were conducted by powder X-ray diffraction (PXRD), differential thermal analysis (DTA) and scanning electron microscopy (SEM) analysis. Interaction of efavirenz and nicotinamide in liquid states was studied by phase solubility profil...

  7. Hydrodynamics for a granular binary mixture at low density

    OpenAIRE

    Garzó, Vicente; Dufty, J.W.

    2001-01-01

    Hydrodynamic equations for a binary mixture of inelastic hard spheres are derived from the Boltzmann kinetic theory. A normal solution is obtained via the Chapman-Enskog method for states near the local homogeneous cooling state. The mass, heat, and momentum fluxes are determined to first order in the spatial gradients of the hydrodynamic fields, and the associated transport coefficients are identified. In the same way as for binary mixtures with elastic collisions, these coefficients are det...

  8. Anomalous orientational relaxation of solute probes in binary mixtures

    OpenAIRE

    Bhattacharyya, Sarika; Bagchi, Biman

    2001-01-01

    The orientation of a solute probe in a binary mixture often exhibits multiple relaxation times at the same solvent viscosity but different compositions [Beddard et al., Nature (London) 294, 145 (1981)]. In order to understand this interesting observation, we have carried out (NPT) molecular dynamics simulation study of rotation of prolate ellipsoids in binary mixtures. The simulations show that for a broad range of model parameters the experimental behavior can be reproduced. The plot of orie...

  9. Effective Potential and Interdiffusion in Binary Ionic Mixtures

    CERN Document Server

    Beznogov, M V

    2014-01-01

    We calculate interdiffusion coefficients in a two-component, weakly or strongly coupled ion plasma (gas or liquid, composed of two ion species immersed into a neutralizing electron background). We use an effective potential method proposed recently by Baalrud and Daligaut [PRL, 110, 235001, (2013)]. It allows us to extend the standard Chapman-Enskog procedure of calculating the interdiffusion coefficients to the case of strong Coulomb coupling. We compute binary diffusion coefficients for several ionic mixtures and fit them by convenient expressions in terms of the generalized Coulomb logarithm. These fits cover a wide range of plasma parameters spanning from weak to strong Coulomb couplings. They can be used to simulate diffusion of ions in ordinary stars as well as in white dwarfs and neutron stars.

  10. Separation of gas mixtures

    International Nuclear Information System (INIS)

    Apparatus is described for the separation of a gaseous plasma mixture into components in some of which the original concentration of a specific ion has been greatly increased or decreased, comprising: a source for converting the gaseous mixture into a train of plasma packets; an open-ended vessel with a main section and at least one branch section, adapted to enclose along predetermined tracks the original plasma packets in the main section, and the separated plasma components in the branch sections; drive means for generating travelling magnetic waves along the predetermined tracks with the magnetic flux vector of the waves transverse to each of the tracks; and means for maintaining phase coherence between the plasma packets and the magnetic waves at a value needed for accelerating the components of the packets to different velocities and in such different directions that the plasma of each packet is divided into distinctly separate packets in some of which the original concentration of a specific ion has been greatly increased or decreased, and which plasma packets are collected from the branch sections of the vessels. (author)

  11. A combined ultrasonic flow meter and binary vapour mixture analyzer for the ATLAS silicon tracker

    Science.gov (United States)

    Bates, R.; Battistin, M.; Berry, S.; Berthoud, J.; Bitadze, A.; Bonneau, P.; Botelho-Direito, J.; Bousson, N.; Boyd, G.; Bozza, G.; Da Riva, E.; Degeorge, C.; Deterre, 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.

    2013-02-01

    We describe a combined ultrasonic instrument for gas flow metering and continuous real-time binary gas composition measurements. The combined flow measurement and mixture analysis algorithm employs sound velocity measurements in two directions in combination with measurements of the pressure and temperature of the process gas mixture. The instrument has been developed in two geometries following extensive computational fluid dynamics studies of various mechanical layouts. A version with an axial sound path has been used with binary gas flows up to 230 l.min-1, while a version with a sound path angled at 45° to the gas flow direction has been developed for use in gas flows up to 20000 l.min-1. The instrument with the axial geometry has demonstrated a flow resolution of flows up to 230 l.min-1 and a mixture resolution of 3.10-3 for C3F8/C2F6 molar mixtures with ~ 20 %C2F6. Higher mixture precision is possible in mixtures of gases with widely-differing molecular weight (mw): a sensitivity of 1yr) continuous study. A prototype instrument with 45° crossing angle has demonstrated a flow resolution of 1.9 % of full scale for linear flow velocities up to 15 ms-1. Although this development was motivated by a requirement of the ATLAS silicon tracker evaporative fluorocarbon cooling system, the developed instrument can be used in many applications where continuous knowledge of binary gas composition is required. Applications include the analysis of hydrocarbons, vapour mixtures for semi-conductor manufacture and anaesthetic gas mixtures.

  12. Determining the Porosity and Saturated Hydraulic Conductivity of Binary Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z. F.; Ward, Anderson L.; Keller, Jason M.

    2009-09-27

    Gravels and coarse sands make up significant portions of some environmentally important sediments, while the hydraulic properties of the sediments are typically obtained in the laboratory using only the fine fraction (e.g., <2 mm or 4.75 mm). Researchers have found that the content of gravel has significant impacts on the hydraulic properties of the bulk soils. Laboratory experiments were conducted to measure the porosity and the saturated hydraulic conductivity of binary mixtures with different fractions of coarse and fine components. We proposed a mixing-coefficient model to estimate the porosity and a power-averaging method to determine the effective particle diameter and further to predict the saturated hydraulic conductivity of binary mixtures. The proposed methods could well estimate the porosity and saturated hydraulic conductivity of the binary mixtures for the full range of gravel contents and was successfully applied to two data sets in the literature.

  13. Foaming binary solution mixtures of low molecular surfactant and polyelectrolyte

    OpenAIRE

    Aidarova, S. B.; Musabekov, K. B.; Ospanova, Z. B.; Güden, Mustafa

    2006-01-01

    The lifetime of water solution foams of sodium dodecylsulfate (DDS, low molecular weight surfactant) and sodium carboxymethylcellulose (SCMC, polyelectrolyte) and their binary mixtures was experimentally investigated. The effects of ionic strength and acidity on the foam life were also determined. In binary solutions, a synergic effect of DDS and SCMC on the surface tension reduction, most likely resulting from the interaction of the surfactant with polymer, was found. The addition of NaCl in...

  14. Thermodynamic coarsening arrested by viscous fingering in partially miscible binary mixtures

    Science.gov (United States)

    Fu, Xiaojing; Cueto-Felgueroso, Luis; Juanes, Ruben

    2016-09-01

    We study the evolution of binary mixtures far from equilibrium, and show that the interplay between phase separation and hydrodynamic instability can arrest the Ostwald ripening process characteristic of nonflowing mixtures. We describe a model binary system in a Hele-Shaw cell using a phase-field approach with explicit dependence of both phase fraction and mass concentration. When the viscosity contrast between phases is large (as is the case for gas and liquid phases), an imposed background flow leads to viscous fingering, phase branching, and pinch off. This dynamic flow disorder limits phase growth and arrests thermodynamic coarsening. As a result, the system reaches a regime of statistical steady state in which the binary mixture is permanently driven away from equilibrium.

  15. Dielectric studies of binary mixtures of -propyl alcohol and ethylenediamine

    Indian Academy of Sciences (India)

    B S Narwade; P G Gawali; Rekha Pande; G M Kalamse

    2005-11-01

    Dielectric constant (') and dielectric loss (") of -propyl alcohol (PA), ethylenediamine (EDA) and their binary mixtures, for different mole fractions of ethylenediamine have been experimentally measured at 11.15 GHz microwave frequency. Values of density (), viscosity () and square refractive index ($n^{2}_{D}$) of binary mixtures as well as those of pure liquids are reported. Excess square refractive index, viscosity and activation energy of viscous flow have also been estimated. These parameters have been used to explain the formation of complexes in the system.

  16. Thermal plasmas in gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, A.B. [CSIRO Telecommunications and Industrial Physics, Lindfield, NSW (Australia)

    2001-10-21

    The calculation and measurement of the properties of thermal plasmas in mixtures of different gases are reviewed. The calculation of composition, thermodynamic properties and transport coefficients is described. Particular attention is given to the calculation of diffusion coefficients, which is a significant problem in mixed-gas plasmas. The combined diffusion coefficient formulation is shown to be a useful method for the treatment of diffusion. Computational fluid dynamic modelling of thermal plasmas in gas mixtures is considered, using the examples of demixing in welding arcs, the turbulent mixing of atmospheric air into a plasma jet and a plasma waste destruction process. Diagnostic techniques for mixed-gas plasmas, in particular emission spectroscopy, laser scattering and laser-induced fluorescence, are discussed. (author)

  17. Isomorphic Viscosity Equation of State for Binary Fluid Mixtures.

    Science.gov (United States)

    Behnejad, Hassan; Cheshmpak, Hashem; Jamali, Asma

    2015-01-01

    The thermodynamic behavior of the simple binary mixtures in the vicinity of critical line has a universal character and can be mapped from pure components using the isomorphism hypothesis. Consequently, based upon the principle of isomorphism, critical phenomena and similarity between P-ρ-T and T-η-(viscosity)-P relationships, the viscosity model has been developed adopting two cubic, Soave-Redlich-Kwong (SRK) and Peng-Robinson (PR), equations of state (EsoS) for predicting the viscosity of the binary mixtures. This procedure has been applied to the methane-butane mixture and predicted its viscosity data. Reasonable agreement with the experimental data has been observed. In conclusion, we have shown that the isomorphism principle in conjunction with the mapped viscosity EoS suggests a reliable model for calculating the viscosity of mixture of hydrocarbons over a wide pressure range up to 35 MPa within the stated experimental errors. PMID:26680701

  18. Ordered Structures of a Binary Mixture with Mobile Particles System

    Institute of Scientific and Technical Information of China (English)

    诸跃进; 马余强

    2003-01-01

    We study the ordered structures of a binary mixture through the introduction of mobile particles under periodically oscillating driving fields, and find that the particle motion can break up the isotropy of the system, so that the continuous structure along the oscillation forcing direction is observed for properly chosen oscillating field.Furthermore, the dependences of the morphology and domain size on the mixture-particle coupling interaction,the diffusion coefficient, and the quench depth are examined in details.

  19. Investigation of critical lines and global phase behavior of unequal size of molecules in binary gas-liquid mixtures in the combined pressure-temperature-concentration planes around the van Laar point

    Science.gov (United States)

    Gençaslan, Mustafa; Keskin, Mustafa

    2016-09-01

    We investigate critical curves and global phase behavior of unequal size of molecules in binary gas-liquid mixtures at the van Laar point and its vicinity. The van Laar point is only point at which the mathematical double point curve is stable, and also the intersection of the tricritical point and the double critical end point. The critical line structure is displayed for various combinations of the chain length and system parameters in the reduced pressure (P∗) temperature (T∗) plane, as is usually done with experimental results and temperature-concentration (T, x) plane. The P∗,T∗ diagrams are discussed in accordance with the Scott and van Konynenburg binary phase diagram classification. We found that our P∗,T∗ plots correspond to the type II, type III, type IV phase diagram behaviors and they are in good agreement with the theoretical and experimental studies. It is also found that the critical lines and phase behavior are extremely sensitive to small modifications in the system parameters.

  20. Separation of gas mixtures by supported complexes

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, D.A.; Lilga, M.A.; Hallen, R.T.; Lyke, S.E.

    1986-08-01

    The goal of this program is to determine the feasibility of solvent-dissolved coordination complexes for the separation of gas mixtures under bench-scale conditions. In particular, mixtures such as low-Btu gas are examined for CO and H/sub 2/ separation. Two complexes, Pd/sub 2/(dpm)/sub 2/Br/sub 2/ and Ru(CO)/sub 2/(PPh/sub 3/)/sub 3/, were examined in a bench-scale apparatus for the separation of binary (CO-N/sub 2/ or H/sub 2/-N/sub 2/) and quinary (H/sub 2/, CO, CO/sub 2/, CH/sub 4/, and N/sub 2/) mixtures. The separation of CO-N/sub 2/ was enhanced by the presence of the palladium complex in the 1,1,2-trichloroethane (TCE) solvent, especially at high gas and low liquid rates. The five-component gas mixture separation with the palladium complex in TCE provided quite unexpected results based on physical solubility and chemical coordination. The complex retained CO, while the solvent retained CO/sub 2/, CH/sub 4/, and N/sub 2/ to varying degrees. This allowed the hydrogen content to be enhanced due to its low solubility in TCE and inertness to the complex. Thus, a one-step, hydrogen separation can be achieved from gas mixtures with compositions similar to that of oxygen-blown coal gas. A preliminary economic evaluation of hydrogen separation was made for a system based on the palladium complex. The palladium system has a separation cost of 50 to 60 cents/MSCF with an assumed capital investment of $1.60/MSCF of annual capacity charged at 30% per year. This assumes a 3 to 4 year life for the complex. Starting with a 90% hydrogen feed, PSA separation costs are in the range of 30 to 50 cents/MSCF. The ruthenium complex was not as successful for hydrogen or carbon monoxide separation due to unfavorable kinetics. The palladium complex was found to strip hydrogen gas from H/sub 2/S. The complex could be regenerated with mild oxidants which removed the sulfur as SO/sub 2/. 24 refs., 26 figs., 10 tabs.

  1. First Binary Mixture Ionic Liquids Containing EMIMBr and IM

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new series of binary mixture ionic liquids comprising 1-ethyl-3-methylimidozaliumbromide (EMIMBr) and imidazole (IM) have been synthesized. The melting points of the ionicliquids vary with the different content of IM while they still keep satisfactory conductivity andviscosity. According to the analysis of its phase diagram, the eutectic point is about 16.5℃ withthe mass percentage of IM 29%.

  2. Phase diagram of highly asymmetric binary hardsphere mixtures

    NARCIS (Netherlands)

    Dijkstra, M.; van Roij, R.H.H.G.; Evans, R.

    1999-01-01

    We study the phase behavior and structure of highly asymmetric binary hard-sphere mixtures. By first integrating out the degrees of freedom of the small spheres in the partition function we derive a formal expression for the effective Hamiltonian of the large spheres. Then using an explicit pairwise

  3. Onsager coefficients for binary mixture diffusion in nanopores

    NARCIS (Netherlands)

    R. Krishna; J.M. van Baten

    2008-01-01

    This paper presents a critical appraisal of current estimation methods for the Onsager coefficients L-11, L-22, and L-12 for binary mixture diffusion inside nanopores using pure component diffusivity data inputs. The appraisal is based on extensive sets of molecular dynamics (MD) simulation data on

  4. Microscopic study and modeling of thermodiffusion in binary associating mixtures.

    Science.gov (United States)

    Eslamian, Morteza; Saghir, M Ziad

    2009-12-01

    Thermodiffusion in associating mixtures is a complex phenomenon, owing to the strong dependence of the molecular structure of such mixtures on concentration. In this paper, we attempt to elucidate this phenomenon and propose a qualitative mechanism for the separation of species in binary associating mixtures. A correlation between the sign change in the thermal diffusion factor and a change in the molecular structure, mixture viscosity, and the excess entropy of mixing in such mixtures is established. To quantify this correlation, we modify our recently developed dynamic model based on the Drickamer nonequilibrium thermodynamic approach [M. Eslamian and M. Z. Saghir, Phys. Rev. E 80, 011201 (2009)] and propose expressions for the estimation of thermal diffusion factor in binary associating mixtures. The prediction power of the proposed expressions, as well as other widely used models, are examined against the experimental data. The proposed theoretical expressions are self-contained and only rely on the viscosity data as input and predict a sign change in the thermal diffusion factor in associating mixtures. PMID:20365155

  5. Analytical processing of binary mixture information by olfactory bulb glomeruli.

    Directory of Open Access Journals (Sweden)

    Max L Fletcher

    Full Text Available Odors are rarely composed of a single compound, but rather contain a large and complex variety of chemical components. Often, these mixtures are perceived as having unique qualities that can be quite different than the combination of their components. In many cases, a majority of the components of a mixture cannot be individually identified. This synthetic processing of odor information suggests that individual component representations of the mixture must interact somewhere along the olfactory pathway. The anatomical nature of sensory neuron input into segregated glomeruli with the bulb suggests that initial input of odor information into the bulb is analytic. However, a large network of interneurons within the olfactory bulb could allow for mixture interactions via mechanisms such as lateral inhibition. Currently in mammals, it is unclear if postsynaptic mitral/tufted cell glomerular mixture responses reflect the analytical mixture input, or provide the initial basis for synthetic processing with the olfactory system. To address this, olfactory bulb glomerular binary mixture representations were compared to representations of each component using transgenic mice expressing the calcium indicator G-CaMP2 in olfactory bulb mitral/tufted cells. Overall, dorsal surface mixture representations showed little mixture interaction and often appeared as a simple combination of the component representations. Based on this, it is concluded that dorsal surface glomerular mixture representations remain largely analytical with nearly all component information preserved.

  6. Segregation in Vertically Vibrated Binary Granular Mixtures with Same Size

    Institute of Scientific and Technical Information of China (English)

    SHI Qing-Fan; SUN Gang; HOU Mei-Ying; LU Kun-Quan

    2006-01-01

    @@ Segregation in vertically vibrated binary granular mixtures with same size is studied experimentally. A new partial segregated state is found in this system. This state exists between the completely mixed state and the pure segregated state, and has the characteristic that the lighter particles tend to rise and form a pure layer on the top of the system while the heavier particles and some of the lighter ones stay at the bottom and form a mixed layer.

  7. Shear viscosity for a moderately dense granular binary mixture

    OpenAIRE

    Garzo, Vicente; Montanero, Jose Maria

    2003-01-01

    The shear viscosity for a moderately dense granular binary mixture of smooth hard spheres undergoing uniform shear flow is determined. The basis for the analysis is the Enskog kinetic equation, solved first analytically by the Chapman-Enskog method up to first order in the shear rate for unforced systems as well as for systems driven by a Gaussian thermostat. As in the elastic case, practical evaluation requires a Sonine polynomial approximation. In the leading order, we determine the shear v...

  8. Viscosity and mutual diffusion in strongly asymmetric binary ionic mixtures

    OpenAIRE

    Bastea, Sorin

    2006-01-01

    We present molecular dynamics simulation results for the viscosity and mutual diffusion constant of a strongly asymmetric binary ionic mixture (BIM). We compare the results with available theoretical models previously tested for much smaller asymmetries. For the case of viscosity we propose a new predictive framework based on the linear mixing rule, while for mutual diffusion we discuss some consistency problems of widely used Boltzmann equation based models.

  9. Viscosity and mutual diffusion in strongly asymmetric binary ionic mixtures

    CERN Document Server

    Bastea, S

    2005-01-01

    We present molecular dynamics simulation results for the viscosity and mutual diffusion constant of a strongly asymmetric binary ionic mixture (BIM). We compare the results with available theoretical models previously tested for much smaller asymmetries. For the case of viscosity we propose a new predictive framework based on the linear mixing rule, while for mutual diffusion we discuss some consistency problems of widely used Boltzmann equation based models.

  10. Effects of lubricants on binary direct compression mixtures.

    Science.gov (United States)

    Uğurlu, T; Halaçoğlu, M D; Türkoğlu, M

    2010-04-01

    The objective of this study was to investigate the effects of conventional lubricants including a new candidate lubricant on binary direct compression mixtures. Magnesium stearate (MGST), stearic acid (STAC), glyceryl behenate (COMP) and hexagonal boron nitride (HBN) were tested. The binary mixtures were 1:1 combinations of spray dried lactose (FlowLac 100), dicalcium phosphate dihydrate (Emcompress), and modified starch (Starch 1500) with microcrystalline cellulose (Avicel PH 102). Tablets were manufactured on a single-station instrumented tablet press with and without lubricants. In the case of unlubricated granules, the modified starch-microcrystalline cellulose mixture provided the highest percent compressibility value at 8.25%, spray dried lactose-microcrystalline cellulose mixture was 7.33%, and the dialcium phosphate dihydrate-microcrystalline cellulose mixture was 5.79%. Their corresponding tablet crushing strength values were: 104 N, 117 N, and 61 N, respectively. The lubricant concentrations studied were 0.5, 1, 2, and 4%. Effects of lubricant type and lubricant concentration on crushing strength were analyzed using a factorial ANOVA model. It was found that the Avicel PH 102-Starch 1500 mixture showed the highest lubricant sensitivity (110 N vs. 9 N), the least affected formulation was FlowLac-Avicel PH 102 mixture (118 N vs. 62 N). The crushing strength vs. concentration curve for MGST showed a typical biphasic profile, a fast drop up to 1% and a slower decline between 1 and 4%. The STAC, COMP, and HBN for all formulations showed a shallow linear decline of tablet crushing strength with increasing lubricant concentration. The HBN was as effective as MGST as a lubricant, and did not show a significant negative effect on the crushing strength of the tablets. The COMP and STAC also did not interfere with the crushing strength, however, they were not as effective lubricants as MGST or HBN. PMID:22491169

  11. Detection And Discrimination Of Pure Gases And Binary Mixtures Using A Single Microcantilever

    Energy Technology Data Exchange (ETDEWEB)

    Loui, A; Sirbuly, D J; Elhadj, S; McCall, S K; Hart, B R; Ratto, T V

    2009-08-06

    A new method for detecting and discriminating pure gases and binary mixtures has been investigated. This approach combines two distinct physical mechanisms within a single piezoresistive microcantilever: heat dissipation and resonant damping in the viscous regime. An experimental study of the heat dissipation mechanism indicates that the sensor response is directly correlated to the thermal conductivity of the gaseous analyte. A theoretical data set of resonant damping was generated corresponding to the gas mixtures examined in the thermal response experiments. The combination of the thermal and resonant response data yields more distinct analyte signatures that cannot otherwise be obtained from the detection modes individually.

  12. Small Scale Evaporation Kinetics of a Binary Fluid Mixture

    Science.gov (United States)

    Basdeo, Carl; Ye, Dezhuang; Kalonia, Devendra; Fan, Tai-Hsi; Mechanical Engineering Team; Pharmaceutical Sciences Collaboration

    2013-03-01

    Evaporation induces a concentrating effect in liquid mixtures. The transient process has significant influence on the dynamic behaviors of a complex fluid. To simultaneously investigate the fluid properties and small-scale evaporation kinetics during the transient process, the quartz crystal microbalance is applied to a binary mixture droplet of light alcohols including both a single volatile component (a fast evaporation followed by a slow evaporation) and a mixture of two volatile components with comparable evaporation rates. The density and viscosity stratification are evaluated by the shear wave, and the evaporation kinetics is measured by the resonant signature of the acoustic p-wave. The evaporation flux can be precisely determined by the resonant frequency spikes and the complex impedance. To predict the concentration field, the moving interface, and the precision evaporation kinetics of the mixture, a multiphase model is developed to interpret the complex impedance signals based on the underlying mass and momentum transport phenomena. The experimental method and theoretical model are developed for better characterizing and understanding of the drying process involving liquid mixtures of protein pharmaceuticals.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, Kazuhiro [Department of Chemistry and Chemical Engineering, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan)], E-mail: tamura@t.kanazawa-u.ac.jp; Li Xiaoli; Li Hengde [Department of Chemistry and Chemical Engineering, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan)

    2009-04-15

    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.

  14. 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...

  15. Effective Potential Theory for Diffusion in Binary Ionic Mixtures

    CERN Document Server

    Shaffer, Nathaniel R; Daligault, Jérôme

    2016-01-01

    Self-diffusion and interdiffusion coefficients of binary ionic mixtures are evaluated using the Effective Potential Theory (EPT), and the predictions are compared with the results of molecular dynamics simulations. We find that EPT agrees with molecular dynamics from weak coupling well into the strong coupling regime, which is a similar range of coupling strengths as previously observed in comparisons with the one-component plasma. Within this range, typical relative errors of approximately 20% and worst-case relative errors of approximately 40% are observed. We also examine the Darken model, which approximates the interdiffusion coefficients based on the self-diffusion coefficients.

  16. Coexisting Pulses in a Model for Binary-Mixture Convection

    CERN Document Server

    Riecke, H; Riecke, Hermann; Rappel, Wouter-Jan

    1995-01-01

    We address the striking coexistence of localized waves (`pulses') of different lengths which was observed in recent experiments and full numerical simulations of binary-mixture convection. Using a set of extended Ginzburg-Landau equations, we show that this multiplicity finds a natural explanation in terms of the competition of two distinct, physical localization mechanisms; one arises from dispersion and the other from a concentration mode. This competition is absent in the standard Ginzburg-Landau equation. It may also be relevant in other waves coupled to a large-scale field.

  17. Structure and rheology of binary mixtures in shear flow

    OpenAIRE

    Corberi, F.; Gonnella, G.; Lamura, A.

    2000-01-01

    Results are presented for the phase separation process of a binary mixture subject to an uniform shear flow quenched from a disordered to a homogeneous ordered phase. The kinetics of the process is described in the context of the time-dependent Ginzburg-Landau equation with an external velocity term. The large-N approximation is used to study the evolution of the model in the presence of a stationary flow and in the case of an oscillating shear. For stationary flow we show that the structure ...

  18. STUDY OF MOLECULAR INTERACTIONS IN BINARY MIXTURES USING EXCESS PARAMETERS

    OpenAIRE

    Narendra Kolla

    2014-01-01

    Speeds of sound, densities and viscosities of the binary mixture of anisaldehyde with nonanol were measured over the entire mole fraction at (303.15, 308.15, 313.15 and 318.15) K E E and normal atmospheric pressure. Excess molar volume, V , Excess internal pressure, π , m E *E excess enthalpy, H , excess Gibb's free energy of activation for viscous flow, G , and excess E E viscosity,η have been calculated using experimental data. The V values are positive whereas m ...

  19. Applicability of linearized Dusty Gas Model for multicomponent diffusion of gas mixtures in porous solids

    OpenAIRE

    Marković Jelena; Omorjan Radovan

    2007-01-01

    The transport of gaseous components through porous media could be described according to the well-known Fick model and its modifications. It is also known that Fick’s law is not suitable for predicting the fluxes in multicomponent gas mixtures, excluding binary mixtures. This model is still frequently used in chemical engineering because of its simplicity. Unfortunately, besides the Fick’s model there is no generally accepted model for mass transport through porous media (membranes, catalysts...

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

    DEFF Research Database (Denmark)

    Monsalvo, Matias Alfonso; Shapiro, Alexander

    2007-01-01

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

  1. Absorption spectra of e-beam-excited Ne, Ar, and Kr, pure and in binary mixtures.

    Science.gov (United States)

    Levchenko, A O; Ustinovskii, N N; Zvorykin, V D

    2010-10-21

    A technique using the broadband emission of a laser plume as probe radiation is applied to record UV-visible (190-510 nm) absorption spectra of Ne, Ar, and Kr, pure and in binary mixtures under moderate e-beam excitation up to 1 MW/cm(3). In all the rare gases and mixtures, the absorption spectra show continuum related to Rg(2) (+) homonuclear ions [peaking at λ∼285, 295, and 320 nm in Ne, Ar, and Kr(Ar/Kr), respectively] and a number of atomic lines related mainly to Rg(∗)(ms) levels, where m is the lowest principal quantum number of the valence electron. In argon, a continuum related to Ar(2) (∗) (λ∼325 nm) is also recorded. There are also trains of narrow bands corresponding to Rg(2) (∗)(npπ (3)Π(g))←Rg(2) (∗)(msσ (3)Σ(u) (+)) transitions. All the spectral features mentioned above were reported in literature but have never been observed simultaneously. Although charge transfer to a homonuclear ion of the heavier additive is commonly believed to dominate in binary rare-gas mixtures, it is found in this study that in Ne/Kr mixture, the charge is finally transferred from the buffer gas Ne(2) (+) ion not to Kr(2) (+) but to heteronuclear NeKr(+) ion.

  2. 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.

  3. Energy landscape view of nonideality in binary mixtures.

    Science.gov (United States)

    Abraham, Sneha Elizabeth; Chakrabarti, Dwaipayan; Bagchi, Biman

    2007-02-21

    Positive and negative deviations from the prediction of Raoult's Law on the composition dependence of a property of binary mixtures are often explained in terms of structure formation and structure breakage, respectively, upon mixing. However, a detailed theoretical description of these ideas seems to be lacking in the literature. Here we present the energy landscape view of nonideality of the viscosity of the binary mixture using two different models, one for structure former and the other for structure breaker. For both the models, the average inherent structure energy shows an inverse correlation with the viscosity. The inherent structures of the structure former indicate that there is a considerable enhancement of short range order due to stronger attractive interaction between the two constituent species. On the other hand, for the structure breaker, there is no such enhancement of short range order due to weaker interaction between the two constituent species. We find the inherent structures of the structure breaker to be phase separated in many cases where the parent phase is homogeneous. When the configurational entropy of the parent liquid is computed for the two model systems, we find that the configurational entropy also shows an inverse correlation with the viscosity in both the cases. PMID:17328614

  4. 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.

  5. Novel microthermal sensor principle for determining the mixture ratio of binary fluid mixtures using Föppl vortices

    OpenAIRE

    B. Schmitt; Kiefer, C; Schütze, A.

    2015-01-01

    A novel sensor principle for determining binary fluid mixtures of known components is presented, making use of different thermal and rheological properties of the mixture's components. Using a microheater, a heat pulse is introduced in the mixture. The resulting temperature increase depends on the thermal properties of the mixture, allowing determination of the mixture ratio. Placing a bluff body in the fluid channel causes the formation of a stationary pair of vortices behi...

  6. Analysis of composition complicated binary mixture by quantitative SEC

    Institute of Scientific and Technical Information of China (English)

    Zhengnian CHEN; Hongfeng XIE; Hu YANG; Zhiliu WANG; Rongshi CHENG

    2008-01-01

    The analyses of the composition of a binary mixture composed of two kinds of industrial complicated materials have great importance for formulation in practice.The present paper provides a quantitative size exclusion chromatography (SEC) method based on the principle of absolute quantification of SEC to solve the problem. The conventional data treatment procedure for the differential refractive index (DRI) signal of SEC H(V) is improved first by dividing it with the injected sample weight and leads to a novel defined weight normalized distribution Hw(V) and its integral Iw(V). These two distributions reflect the response constant of the sample in addition to the conventional normalized distribution F(V). The difference of the average response constants of the composing components provides a sensitive method to compute the composition of their mixture from its Hw(V) or Iw(V). The method was applied to mixtures of a kind of industrial asphalt and paraffin diluents as an example, and successful results are obtained.

  7. Evaporation of Ethanol-Water Binary Mixture Sessile Liquid Marbles.

    Science.gov (United States)

    Ooi, Chin Hong; Bormashenko, Edward; Nguyen, Anh V; Evans, Geoffrey M; Dao, Dzung V; Nguyen, Nam-Trung

    2016-06-21

    Liquid marble is a liquid droplet coated with particles. Recently, the evaporation process of a sessile liquid marble using geometric measurements has attracted great attention from the research community. However, the lack of gravimetric measurement limits further insights into the physical changes of a liquid marble during the evaporation process. Moreover, the evaporation process of a marble containing a liquid binary mixture has not been reported before. The present paper investigates the effective density and the effective surface tension of an evaporating liquid marble that contains aqueous ethanol at relatively low concentrations. The effective density of an evaporating liquid marble is determined from the concurrent measurement of instantaneous mass and volume. Density measurements combined with surface profile fitting provide the effective surface tension of the marble. We found that the density and surface tension of an evaporating marble are significantly affected by the particle coating.

  8. Instabilities in granular binary mixtures at moderate densities

    Science.gov (United States)

    Mitrano, Peter P.; Garzó, Vicente; Hrenya, Christine M.

    2014-02-01

    A linear stability analysis of the Navier-Stokes (NS) granular hydrodynamic equations is performed to determine the critical length scale for the onset of vortices and clusters instabilities in granular dense binary mixtures. In contrast to previous attempts, our results (which are based on the solution to the inelastic Enskog equation to NS order) are not restricted to nearly elastic systems since they take into account the complete nonlinear dependence of the NS transport coefficients on the coefficients of restitution αij. The theoretical predictions for the critical length scales are compared to molecular dynamics (MD) simulations in flows of strong dissipation (αij≥0.7) and moderate solid volume fractions (ϕ ≤0.2). We find excellent agreement between MD and kinetic theory for the onset of velocity vortices, indicating the applicability of NS hydrodynamics to polydisperse flows even for strong inelasticity, finite density, and particle dissimilarity.

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

    CERN Document Server

    Bean, K H

    1997-01-01

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

  10. Critical phenomena in thick films of a binary liquid mixture

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, D.T.

    1976-01-01

    The first experimental data on the behavior of a critical system as it approaches two dimensionality are presented. Measurements of the bulk coexistence curve by use of refractive index techniques were done on the binary fluid mixture methanol--cyclohexane. These measurements gave the critical exponent ..beta.. = 0.326 +- 0.003, which agrees with recent Ising-model calculations. This same binary fluid mixture was then constrained between two highly reflective, optically flat pieces of fused silica in an interferometer. The critical temperature and coexistence curve were determined as the spacing between the flats was varied from 1 ..mu..m to 60 ..mu..m. The critical temperature was directly measured for spacings between 3 and 60 ..mu..m. It was found that, if the walls were close enough together (less than or equal to 6 ..mu..m), then the drops that form on phase separation would span the intervening space. The coexistence curves of these thick films (less than or equal to 6 ..mu..m) were determined from measurements of the difference in refractive index between the two phases that appeared as drops. It was found that the shift in the critical temperature as the spacing was varied followed a logarithmic dependence. Such a dependence is not expected from Scaling Theory for an Ising model, but is to be expected of systems with effectively infinite-range interactions. The coexistence curves for each spacing of the thick film indicated that the critical exponent ..beta.. was close to 0.5, which is the mean-field (infinite-range-interaction) value and not the two-dimensional Ising-model value of 0.125. The amplitude of the coexistence curves was found to vary with spacing as L/sup z/ with z in the range 0.6 ..-->.. 0.8. This was a much larger dependence than expected from the theory. 29 figures, 5 tables

  11. Henry's law, surface tension, and surface adsorption in dilute binary mixtures

    OpenAIRE

    Onuki, Akira

    2009-01-01

    Equilibrium properties of dilute binary fluid mixtures are studied in two-phase states on the basis of a Helmholtz free energy including the gradient free energy. The solute partitioning between gas and liquid (Henry's law) and the surface tension change $\\Delta\\gamma$ are discussed. A derivation of the Gibbs law $\\Delta\\gamma=-T\\Gamma$ is given with $\\Gamma$ being the surface adsorption. Calculated quantities include the derivatives $d T_c/dX$ and $d p_c/dX$ of the critical temperature and p...

  12. Modeling Phase Equilibria for Acid Gas Mixtures Using the CPA Equation of State. I. Mixtures with H2S

    DEFF Research Database (Denmark)

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

    2010-01-01

    The Cubic-Plus-Association (CPA) equation of state is applied to a large variety of mixtures containing H2S, which are of interest in the oil and gas industry. Binary H2S mixtures with alkanes, CO2, water, methanol, and glycols are first considered. The interactions of H2S with polar compounds...... (water, methanol, and glycols) are modeled assuming presence or not of cross-association interactions. Such interactions are accounted for using either a combining rule or a cross-solvation energy obtained from spectroscopic data. Using the parameters obtained from the binary systems, one ternary...

  13. Electron swarm and transport coefficients for the binary mixtures of SF6 with Ar and Xe

    International Nuclear Information System (INIS)

    A pulsed Townsend technique was used to measure the electron drift velocity, the longitudinal diffusion, and the effective ionization coefficients, and the limiting field strength for the binary mixtures of SF6 with Ar and Xe. This paper covered a wide range of the density-reduced electric field strength E/N between 50 and 700 Td (1 Townsend (Td) = 10-17 V cm2). The content of SF6 in the gas mixtures was varied over the range 1-90%. For the SF6-Ar mixture, the electron drift velocities were found to be higher than those for pure SF6, and conversely for the SF6-Xe mixture. The above can be explained in terms of the larger momentum transfer cross-section for electrons in Xe than in Ar. The limiting field strength for the SF6-Xe mixture was found to be higher than that for the SF6-Ar one, but still lower than that for the SF6-N2 mixture

  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. Velocity limitations in coaxial plasma gun experiments with gas mixtures

    International Nuclear Information System (INIS)

    The velocity limitations found in many crossed field plasma experiments with neutral gas present are studied for binary mixtures of H2, He, N2 O2, Ne and Ar. The apparatus used is a coaxial plasma gun with an azimuthal magnetic bias field. The discharge parameters are chosen so that the plasma is weakly ionized. In some of the mixtures it is found that one of the components tends to dominate in the sense that only a small amount (regarding volume) of that component is needed for the discharge to adopt a limiting velocity close to that for the pure component. Thus in a mixture between a heavy and a light component having nearly equal ionization potentials the heavy component dominates. Also if there is a considerable difference in ionization potential between the components, the component with the lowest ionization potential tends to dominate. (author)

  16. Nitrocarburizing in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

    2011-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammonia-propene-hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere and str...

  17. Heat Transfer in Nucleate Pool Boiling of Binary and Ternary Refrigerant Mixtures

    Institute of Scientific and Technical Information of China (English)

    赵耀华; 刁彦华; 鹤田隆治; 西川日出男

    2004-01-01

    Heat transfer coefficients in nucleate pool boiling were measured on a horizontal copper surface for refrigerants, HFC-134a, HFC-32, and HFC-125, their binary and ternary mixtures under saturated conditions at 0.9MPa. Compared to pure components, both binary and ternary mixtures showed lower heat transfer coefficients.This deterioration was more pronounced as heat flux was increased. Experimental data were compared with some empirical and semi-empirical correlations available in literature. For binary mixture, the accuracy of the correlations varied considerably with mixtures and the heat flux. Experimental data for HFC-32/134a/125 were also compared with available correlated equation obtained by Thome. For ternary mixture, the boiling range of binary mixture composed by the pure fluids with the lowest and the medium boiling points, and their concentration difference had important effects on boiling heat transfer coefficients.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-14

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

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    A tensiometer operating on the Wilhelmy plate method was employed to measure liquid-vapor interfacial tensions of three binary mixtures and one ternary mixture of decane with eicosane, docosane, and tetracosane. Tensions of binary mixtures n-C10H22 + n-C20H42, n-C10H22 + n-C22H46, and n-C10H22 + n...

  20. Phase behaviour of a binary mixture of long thin rods

    Science.gov (United States)

    Clarke, N.; McLeish, T. C. B.

    1992-10-01

    We study a binary mixture of long thin rodlike particles using an idealised model in which the rods have restricted orientations and the two types of rod differ only in length. Assuming a hard core potential the virial coefficients up to fourth order are calculated exactly. The free energy is minimized with respect to the orientational distribution functions to give the phase (isotropic or nematic) of the system as the concentration is varied. Conditions for coexistence are then calculated, from which we predict the phase behaviour for mixtures with length ratios of 2.0, 5.0 and 10.0, in both the second and fourth virial approximations. Nous étudions un mélange binaire de molécules en forme de bâtonnets au moyen d'un modèle où les bâtonnets ont une distribution d'orientation limitée et se différencient seulement en longueur. En supposant un potentiel de coeur dur, on calcule exactement les coefficients du viriel jusqu'au quatrième ordre. L'énergie libre est minimisée par rapport à la distribution d'orientation et donne la phase (isotropique ou nématique ) du système en fonction de la concentration. On calcule ensuite les conditions de coexistence et le comportement de phase pour des mélanges avec des rapports de longueur de 2,0, 5,0 et 10,0, utilisant les approximations du deuxième et quatrième ordres.

  1. Decomposition and interface evolution in films of binary mixtures

    Science.gov (United States)

    Madruga, Santiago; Bribesh, Fathi; Thiele, Uwe

    2011-11-01

    Model-H describes the coupled transport of concentration and momentum in binary mixtures such as polymer blends. Films of polymer blends are used in technological applications that involve coatings or the creation of structural functional layers. We use an extended version of the model-H for free evolving surfaces to analyze the stability of vertically stratified base states of polymer blends on a solid substrate. We determine the bifurcation diagram of the films by studying their free energy, and L2-norms of surface deflection and concentration field. We provide results for selected mean film thickness with and without energetic bias at the free surface and discuss the role of composition in extended and laterally bounded systems. In addition, we show that the inclusion of convective transport leads to new mechanisms of instability as compared to the purely diffusive case,. S.M. acknowledges support via FP7 Marie Curie Reintegration Grant (PERG04-GA-2008-234384), and U.T. by EU via FP7 (PITN-GA-2008-214919).

  2. New thermal diffusion coefficient measurements for hydrocarbon binary mixtures: viscosity and composition dependency.

    Science.gov (United States)

    Leahy-Dios, Alana; Zhuo, Lin; Firoozabadi, Abbas

    2008-05-22

    New thermal diffusion coefficients of binary mixtures are measured for n-decane-n-alkanes and 1-methylnaphthalene-n-alkanes with 25 and 75 wt % at 25 degrees C and 1 atm using the thermogravitational column technique. The alkanes range from n-pentane to n-eicosane. The new results confirm the recently observed nonmonotonic behavior of thermal diffusion coefficients with molecular weight for binary mixtures of n-decane- n-alkanes at the compositions studied. In this work, the mobility and disparity effects on thermal diffusion coefficients are quantified for binary mixtures. We also show for the binary mixtures studied that the thermal diffusion coefficients and mixture viscosity, both nonequilibrium properties, are closely related. PMID:18438988

  3. th-Nearest neighbour distribution functions of a binary fluid mixture

    Indian Academy of Sciences (India)

    P Sur; B Bhattacharjee

    2009-09-01

    For obtaining microscopic structural information in binary mixtures, often partial pair correlation functions are used. In the present study, a general approach is presented for obtaining the neighbourhood structural information for binary mixtures in terms of nth nearest neighbour distribution (NND) functions (for = 1, 2, 3, ...$\\ldots$). These functions are derived from the partial pair correlation functions in a hierarchical manner, based on the approach adopted earlier by us for single component fluids. Comparison of the results with MD simulation for Lennard-Jones binary mixtures is also presented. NND functions show reasonable matching for smaller n values particularly at higher density. The average th nearest neighbour distance shows interesting feature.

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

    Institute of Scientific and Technical Information of China (English)

    Hamid Reza Rafiee; Mina Rastgar; Neda Heidari

    2011-01-01

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

  5. Nitrocarburising in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

    2010-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammoniapropene- hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...... and straightforward control of the carburizing and nitriding potentials is in principle possible. The nitrocarburising response of unalloyed (ARMCO) Fe was investigated in a thermobalance during controlled nitrocarburising at 580°C. The “cases” obtained on nitrocarburised iron were characterized by reflected light...

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

    OpenAIRE

    Němec Tomáš

    2015-01-01

    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 ...

  7. Effects of a temperature dependent viscosity on thermal convection in binary mixtures

    OpenAIRE

    Hilt, Markus; Glässl, Martin; Zimmermann, Walter

    2013-01-01

    We investigate the effect of a temperature dependent viscosity on the onset of thermal convection in a horizontal layer of a binary fluid mixture that is heated from below. For an exponential temperature dependence of the viscosity, we find in binary mixtures as a function of a positive separation ratio and beyond a certain viscosity contrast a discontinuous transition between two stationary convection modes having a different wavelength. In the range of negative values of the separation rati...

  8. Lattice Boltzmann Study of Velocity Behaviour in Binary Mixtures Under Shear

    OpenAIRE

    Xu, Aiguo; Gonnella, G.

    2003-01-01

    We apply lattice Boltzmann methods to study the relaxation of the velocity profile in binary fluids under shear during spinodal decomposition. In simple fluids, when a shear flow is applied on the boundaries of the system, the time required to obtain a triangular profile is inversely proportional to the viscosity and proportional to the square of the size of the system. We find that the same behaviour also occurs for binary mixtures, for any component ratio in the mixture and independently fr...

  9. Mass dependence of shear viscosity in a binary fluid mixture: mode-coupling theory.

    Science.gov (United States)

    Ali, Sk Musharaf; Samanta, Alok; Choudhury, Niharendu; Ghosh, Swapan K

    2006-11-01

    An expression for the shear viscosity of a binary fluid mixture is derived using mode-coupling theory in order to study the mass dependence. The calculated results on shear viscosity for a binary isotopic Lennard-Jones fluid mixture show good agreement with results from molecular dynamics simulation carried out over a wide range of mass ratio at different composition. Also proposed is a new generalized Stokes-Einstein relation connecting the individual diffusivities to shear viscosity. PMID:17279895

  10. TOPICAL REVIEW: Thermal plasmas in gas mixtures

    Science.gov (United States)

    Murphy, A. B.

    2001-10-01

    The calculation and measurement of the properties of thermal plasmas in mixtures of different gases are reviewed. The calculation of composition, thermodynamic properties and transport coefficients is described. Particular attention is given to the calculation of diffusion coefficients, which is a significant problem in mixed-gas plasmas. The combined diffusion coefficient formulation is shown to be a useful method for the treatment of diffusion. Computational fluid dynamic modelling of thermal plasmas in gas mixtures is considered, using the examples of demixing in welding arcs, the turbulent mixing of atmospheric air into a plasma jet and a plasma waste destruction process. Diagnostic techniques for mixed-gas plasmas, in particular emission spectroscopy, laser scattering and laser-induced fluorescence, are discussed.

  11. 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.

  12. Separation of SF6 from gas mixtures using gas hydrate formation.

    Science.gov (United States)

    Cha, Inuk; Lee, Seungmin; Lee, Ju Dong; Lee, Gang-woo; Seo, Yongwon

    2010-08-15

    This study aims to examine the thermodynamic feasibility of separating sulfur hexafluoride (SF(6)), which is widely used in various industrial fields and is one of the most potent greenhouse gases, from gas mixtures using gas hydrate formation. The key process variables of hydrate phase equilibria, pressure-composition diagram, formation kinetics, and structure identification of the mixed gas hydrates, were closely investigated to verify the overall concept of this hydrate-based SF(6) separation process. The three-phase equilibria of hydrate (H), liquid water (L(W)), and vapor (V) for the binary SF(6) + water mixture and for the ternary N(2) + SF(6) + water mixtures with various SF(6) vapor compositions (10, 30, 50, and 70%) were experimentally measured to determine the stability regions and formation conditions of pure and mixed hydrates. The pressure-composition diagram at two different temperatures of 276.15 and 281.15 K was obtained to investigate the actual SF(6) separation efficiency. The vapor phase composition change was monitored during gas hydrate formation to confirm the formation pattern and time needed to reach a state of equilibrium. Furthermore, the structure of the mixed N(2) + SF(6) hydrate was confirmed to be structure II via Raman spectroscopy. Through close examination of the overall experimental results, it was clearly verified that highly concentrated SF(6) can be separated from gas mixtures at mild temperatures and low pressure conditions. PMID:20704207

  13. Shear viscosity of a hadronic gas mixture

    OpenAIRE

    Itakura, Kazunori; Morimatsu, Osamu; Otomo, Hiroshi

    2007-01-01

    We discuss in detail the shear viscosity coefficient eta and the viscosity to entropy density ratio eta/s of a hadronic gas comprised of pions and nucleons. In particular, we study the effects of baryon chemical potential on eta and eta/s. We solve the relativistic quantum Boltzmann equations with binary collisions (pi pi, pi N, and NN) for a state slightly deviated from thermal equilibrium at temperature T and baryon chemical potential mu. The use of phenomenological amplitudes in the collis...

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

    CERN Document Server

    Stroev, N E

    2016-01-01

    Non-congruent gas-liquid phase transition (NCPT) have been studied in modified Coulomb model of a binary ionic mixture C(+6) + O(+8) on a \\textit{uniformly compressible} ideal electronic background /BIM($\\sim$)/. The features of NCPT in improved version of the BIM($\\sim$) model for the same mixture on background of \\textit{non-ideal} electronic Fermi-gas and comparison it with the previous calculations are the subject of present study. Analytical fits for Coulomb corrections to EoS 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 (CPL) were calculated on the entire range of proportions of mixed ions $0

  15. Mixing Enthalpy for Binary Mixtures Containing Ionic Liquids.

    Science.gov (United States)

    Podgoršek, A; Jacquemin, J; Pádua, A A H; Costa Gomes, M F

    2016-05-25

    A complete review of the published data on the mixing enthalpies of mixtures containing ionic liquids, measured directly using calorimetric techniques, is presented in this paper. The field of ionic liquids is very active and a number of research groups in the world are dealing with different applications of these fluids in the fields of chemistry, chemical engineering, energy, gas storage and separation or materials science. In all these fields, the knowledge of the energetics of mixing is capital both to understand the interactions between these fluids and the different substrates and also to establish the energy and environmental cost of possible applications. Due to the relative novelty of the field, the published data is sometimes controversial and recent reviews are fragmentary and do not represent a set of reliable data. This fact can be attributed to different reasons: (i) difficulties in controlling the purity and stability of the ionic liquid samples; (ii) availability of accurate experimental techniques, appropriate for the measurement of viscous, charged, complex fluids; and (iii) choice of an appropriate clear thermodynamic formalism to be used by an interdisciplinary scientific community. In this paper, we address all these points and propose a critical review of the published data, advise on the most appropriate apparatus and experimental procedure to measure this type of physical-chemical data in ionic liquids as well as the way to treat the information obtained by an appropriate thermodynamic formalism.

  16. Mixing process of a binary gas in a density stratified layer

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Tetsuaki [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1997-09-01

    This study is to investigate the effect of natural convection on the mixing process by molecular diffusion in a vertical stratified layer of a binary fluid. There are many experimental and analytical studies on natural convection in the vertical fluid layer. However, there are few studies on natural convection with molecular diffusion in the vertical stratified layer of a binary gas. Experimental study has been performed on the combined phenomena of molecular diffusion and natural convection in a binary gas system to investigate the mixing process of the binary gas in a vertical slot consisting of one side heated and the other side cooled. The range of Rayleigh number based on the slot width was about 0 < Ra{sub d} < 7.5 x 10{sup 4}. The density change of the gas mixture and the temperature distribution in the slot was obtained and the mixing process when the heavier gas ingress into the vertical slot filled with the lighter gas from the bottom side of the slot was discussed. The experimental results showed that the mixing process due to molecular diffusion was affected significantly by the natural convection induced by the slightly temperature difference between both vertical walls even if a density difference by the binary gas is larger than that by the temperature difference. (author). 81 refs.

  17. Computation of the acoustic nonlinearity parameter in organic liquid binary mixtures

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on Jacobson's molecular free length theory in liquids and the relationship between the ultrasonic velocity and the molecular free length in organic liquids,the equation of the acoustic nonlinearity parameter in organic liquid binary mixtures is derived.The calculated values from the equation are in good agreement both with those from Apfel's and from Sehgal's mixture laws.

  18. 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, even...... 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....

  19. Hydrolysis of Carbonyl Sulfide in Binary Mixture of Diethylene Glycol Diethyl Ether and Water

    Institute of Scientific and Technical Information of China (English)

    李新学; 刘迎新; 魏雄辉

    2005-01-01

    The solubility and hydrolysis of carbonyl sulfide in binary mixture of diethylene glycol diethyl ether and water are studied as a function of composition. The use of an aqueous solution of diethylene glycol diethyl ether enhances the solubility and hydrolysis rate of carbonyl sulfide compared with that in pure water. The composition of the mixture with maximum hydrolysis rate varies with temperature. The thermophysical properties including density, viscosity, and surface tension as a function of composition at 20℃ under atmospheric pressure as well as liquid-liquid equilibrium (LLE) data over the temperature range from 28℃ to 90℃ are also measured for the binary mixture.

  20. Multi Parameter Flow Meter for On-Line Measurement of Gas Mixture Composition

    Directory of Open Access Journals (Sweden)

    Egbert van der Wouden

    2015-04-01

    Full Text Available In this paper we describe the development of a system and model to analyze the composition of gas mixtures up to four components. The system consists of a Coriolis mass flow sensor, density, pressure and thermal flow sensor. With this system it is possible to measure the viscosity, density, heat capacity and flow rate of the medium. In a next step the composition can be analyzed if the constituents of the mixture are known. This makes the approach universally applicable to all gasses as long as the number of components does not exceed the number of measured properties and as long as the properties are measured with a sufficient accuracy. We present measurements with binary and ternary gas mixtures, on compositions that range over an order of magnitude in value for the physical properties. Two platforms for analyses are presented. The first platform consists of sensors realized with MEMS fabrication technology. This approach allows for a system with a high level of integration. With this system we demonstrate a proof of principle for the analyses of binary mixtures with an accuracy of 10%. In the second platform we utilize more mature steel sensor technology to demonstrate the potential of this approach. We show that with this technique, binary mixtures can be measured within 1% and ternary gas mixtures within 3%.

  1. IGNITION IMPROVEMENT OF LEAN NATURAL GAS MIXTURES

    Energy Technology Data Exchange (ETDEWEB)

    Jason M. Keith

    2005-02-01

    This report describes work performed during a thirty month project which involves the production of dimethyl ether (DME) on-site for use as an ignition-improving additive in a compression-ignition natural gas engine. A single cylinder spark ignition engine was converted to compression ignition operation. The engine was then fully instrumented with a cylinder pressure transducer, crank shaft position sensor, airflow meter, natural gas mass flow sensor, and an exhaust temperature sensor. Finally, the engine was interfaced with a control system for pilot injection of DME. The engine testing is currently in progress. In addition, a one-pass process to form DME from natural gas was simulated with chemical processing software. Natural gas is reformed to synthesis gas (a mixture of hydrogen and carbon monoxide), converted into methanol, and finally to DME in three steps. Of additional benefit to the internal combustion engine, the offgas from the pilot process can be mixed with the main natural gas charge and is expected to improve engine performance. Furthermore, a one-pass pilot facility was constructed to produce 3.7 liters/hour (0.98 gallons/hour) DME from methanol in order to characterize the effluent DME solution and determine suitability for engine use. Successful production of DME led to an economic estimate of completing a full natural gas-to-DME pilot process. Additional experimental work in constructing a synthesis gas to methanol reactor is in progress. The overall recommendation from this work is that natural gas to DME is not a suitable pathway to improved natural gas engine performance. The major reasons are difficulties in handling DME for pilot injection and the large capital costs associated with DME production from natural gas.

  2. Ultrasonic study on organic liquid and binary organic liquid mixtures by using Schaaffs' collision factor theory

    Institute of Scientific and Technical Information of China (English)

    Lu Yi-Gang; Dong Yan-Wu

    2006-01-01

    Based on Schaaff's collision factor theory (CFT) in liquids, the equations for nonlinear ultrasonic parameters in both organic liquid and binary organic liquid mixtures are deduced. The nonlinear ultrasonic parameters, including pressure coefficient, temperature coefficients of ultrasonic velocity, and nonlinear acoustic parameter B/A in both organic liquid and binary organic liquid mixtures, are evaluated for comparison with the measured results and data from other sources. The equations show that the coefficient of ultrasonic velocity and nonlinear acoustic parameter B/A are closely related to molecular interactions. These nonlinear ultrasonic parameters reflect some information of internal structure and outside status of the medium or mixtures. From the exponent of repulsive forces of the molecules,several thermodynamic parameters, pressure and temperature of the medium, the nonlinear ultrasonic parameters and ultrasonic nature of the medium can be evaluated. When evaluating and studying nonlinear acoustic parameter B/A of binary organic liquid mixtures, there is no need to know the nonlinear acoustic parameter B/A of the components.Obviously, the equation reveals the connection between the nonlinear ultrasonic nature and internal structure and outside status of the mixtures more directly and distinctly than traditional mixture law for B/A, e.g. Apfel's and Sehgal's laws for liquid binary mixtures.

  3. Heterogeneity in binary mixtures of dimethyl sulfoxide and glycerol: Fluorescence correlation spectroscopy

    Science.gov (United States)

    Chattoraj, Shyamtanu; Chowdhury, Rajdeep; Ghosh, Shirsendu; Bhattacharyya, Kankan

    2013-06-01

    Diffusion of four coumarin dyes in a binary mixture of dimethyl sulfoxide (DMSO) and glycerol is studied using fluorescence correlation spectroscopy (FCS). The coumarin dyes are C151, C152, C480, and C481. In pure DMSO, all the four dyes exhibit a very narrow (almost uni-modal) distribution of diffusion coefficient (Dt). In contrast, in the binary mixtures all of them display a bimodal distribution of Dt with broadly two components. One of the components of Dt corresponds to the bulk viscosity. The other one is similar to that in pure DMSO. This clearly indicates the presence of two distinctly different nano-domains inside the binary mixture. In the first, the micro-environment of the solute consists of both DMSO and glycerol approximately at the bulk composition. The other corresponds to a situation where the first layer of the solute consists of DMSO only. The burst integrated fluorescence lifetime (BIFL) analysis also indicates presence of two micro-environments one of which resembles DMSO. The relative contribution of the DMSO-like environment obtained from the BIFL analysis is much larger than that obtained from FCS measurements. It is proposed that BIFL corresponds to an instantaneous environment in a small region (a few nm) around the probe. FCS, on the contrary, describes the long time trajectory of the probes in a region of dimension ˜200 nm. The results are explained in terms of the theory of binary mixtures and recent simulations of binary mixtures containing DMSO.

  4. Transport properties of supercritical fluids and their binary mixtures

    CERN Document Server

    Luedemann, H D

    2002-01-01

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

  5. Adsorption at the liquid-vapor surface of a binary liquid mixture

    Science.gov (United States)

    Whitmer, J. K.; Kiselev, S. B.; Law, B. M.

    2005-11-01

    In a binary liquid mixture, the component possessing the lowest surface tension preferentially adsorbs at the liquid-vapor surface. In the past this adsorption behavior has been extensively investigated for critical binary liquid mixtures near the mixture's critical temperature Tc. In this fluctuation-dominated regime the adsorption is described by a universal function of the dimensionless depth z /ξ where ξ is the bulk correlation length. Fewer studies have quantitatively examined adsorption for off-critical mixtures because, in this case, one must carefully account for both the bulk and surface crossover from the fluctuation-dominated regime (close to Tc) to the mean-field dominated regime (far from Tc). In this paper we compare extensive liquid-vapor ellipsometric adsorption measurements for the mixture aniline+cyclohexane at a variety of critical and noncritical compositions with the crossover theory of Kiselev and co-workers [J. Chem. Phys. 112, 3370 (2000)].

  6. Atomic capture and transfer of negative pions stopped in binary mixtures of hydrogen with polyatomic gases

    Energy Technology Data Exchange (ETDEWEB)

    Vasilyev, V.A.; Levay, B.; Minkova, A.; Petrukhin, V.I.; Horvath, D.

    1985-12-01

    The atomic capture and transfer of stopped negative pions have been studied in binary gas mixtures of H/sub 2/+M, where M is CCl/sub 2/F/sub 2/, CClF/sub 3/, CBrF/sub 3/ or SF/sub 6/. The ..pi../sup 0/ yield, versus relative atomic concentration Csub(A) of M, goes through a maximum at Csub(A)proportional0.1 and levels off at zero at high concentrations. This phenomenon together with other observed characteristics of the atomic capture and transfer of pions in these systems is interpreted in the frame of a phenomenological model. The average transfer coefficients anti ..lambda..sub(Z) exhibit a weak concentration dependence. The estimated average atomic capture ratios anti A(Z/H) are lower than those found for noble gases, probably because of the mutual screening of the constituent atoms in the molecules. The probability of pion capture in an atomic orbit is not proportional to the stopping power of the components of the mixture. (orig.).

  7. Shear viscosity of a hadronic gas mixture

    CERN Document Server

    Itakura, Kazunori; Otomo, Hiroshi

    2007-01-01

    We discuss in detail the shear viscosity coefficient eta and the viscosity to entropy density ratio eta/s of a hadronic gas comprised of pions and nucleons. In particular, we study the effects of baryon chemical potential on eta and eta/s. We solve the relativistic quantum Boltzmann equations with binary collisions (pi pi, pi N, and NN) for a state slightly deviated from thermal equilibrium at temperature T and baryon chemical potential mu. The use of phenomenological amplitudes in the collision terms, which are constructed to reproduce experimental data, greatly helps to extend the validity region in the T-mu plane. The total viscosity coefficient eta(T,mu)=eta^pi + eta^N increases as a function of T and mu, indirectly reflecting energy dependences of binary cross sections. The increase in mu direction is due to enhancement of the nucleon contribution eta^N while the pion contribution eta^pi diminishes with increasing mu. On the other hand, due to rapid growth of entropy density, the ratio eta/s becomes a de...

  8. 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.

  9. Correlation and prediction of thermodynamic properties of binary mixtures from perturbed chain statistical associating fluid theory

    Science.gov (United States)

    Almasi, Mohammad

    2014-11-01

    Densities and viscosities for binary mixtures of Diethanolamine (DEA) + 2 alkanol (2 propanol up to 2 pentanol) were measured over the entire composition range and temperature interval of 293.15-323.15 K. From the density and viscosity data, values of various properties such as isobaric thermal expansibility, excess isobaric thermal expansibility, partial molar volumes, excess molar volumes and viscosity deviations were calculated. The observed variations of these parameters, with alkanols chain length and temperature, are discussed in terms of the intermolecular interactions between the unlike molecules of the binary mixtures. The ability of the perturbed chain statistical associating fluid theory (PC-SAFT) to correlate accurately the volumetric behavior of the binary mixtures is demonstrated.

  10. Pressure and temperature dependence of viscosity and diffusion coefficients of a glassy binary mixture

    OpenAIRE

    Mukherjee, Arnab; Bhattacharyya, Sarika; Bagchi, Biman

    2002-01-01

    Extensive isothermal-isobaric (NPT) molecular dynamics simulations at many different temperatures and pressures have been carried out in the well-known Kob-Andersen binary mixture model to monitor the effect of pressure (P) and temperature (T) on the dynamic properties such as the viscosity (\\eta) and the self-diffusion (Di) coefficients of the binary system. The following results have been obtained: (i) Compared to temperature, pressure is found to have a weaker effect on the dynamical prope...

  11. Drag Coefficient of a Spherical Droplet Immersed in a Near-Critical Binary Fluid Mixture

    Science.gov (United States)

    Fujitani, Youhei

    2014-02-01

    We consider a spherical liquid droplet immersed in a near-critical binary fluid mixture. A weak preferential attraction is assumed between the droplet and one of the two mixture components, and the difference in the viscosity is neglected between the mixture components. Using the Gaussian free-energy functional, we calculate the drag coefficient of a droplet. Whether it is increased or decreased by the preferential attraction turns out to depend on the bulk correlation length and the ratio of the viscosity of the surrounding mixture to that of the droplet.

  12. Lattice Boltzmann Study of Velocity Behaviour in Binary Mixtures Under Shear

    CERN Document Server

    Xu, A; Xu, Aiguo

    2003-01-01

    We apply lattice Boltzmann methods to study the relaxation of the velocity profile in binary fluids under shear during spinodal decomposition. In simple fluids, when a shear flow is applied on the boundaries of the system, the time required to obtain a triangular profile is inversely proportional to the viscosity and proportional to the square of the size of the system. We find that the same behaviour also occurs for binary mixtures, for any component ratio in the mixture and independently from the time when shear flow is switched on during phase separation.

  13. Effects of a temperature dependent viscosity on thermal convection in binary mixtures

    CERN Document Server

    Hilt, Markus; Zimmermann, Walter

    2013-01-01

    We investigate the effect of a temperature dependent viscosity on the onset of thermal convection in a horizontal layer of a binary fluid mixture that is heated from below. For an exponential temperature dependence of the viscosity, we find in binary mixtures as a function of a positive separation ratio and beyond a certain viscosity contrast a discontinuous transition between two stationary convection modes having a different wavelength. In the range of negative values of the separation ratio, a (continuous or discontinuous) transition from an oscillatory to a stationary onset of convection occurs beyond a certain viscosity contrast, and for large values of the viscosity ratio, the oscillatory onset of convection is suppressed.

  14. Travelling waves near a critical point of a binary fluid mixture

    CERN Document Server

    Gouin, Henri; Ruggeri, Tommaso; 10.1016/j.ijnonlinmec.2011.09.016

    2011-01-01

    Travelling waves of densities of binary fluid mixtures are investigated near a critical point. The free energy is considered in a non-local form taking account of the density gradients. The equations of motions are applied to a universal form of the free energy near critical conditions and can be integrated by a rescaling process where the binary mixture is similar to a single fluid. Nevertheless, density solution profiles obtained are not necessarily monotonic. As indicated in Appendix, the results might be extended to other topics like finance or biology.

  15. Thermodynamic properties and diffusion of water + methane binary mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Shvab, I.; Sadus, Richard J., E-mail: rsadus@swin.edu.au [Centre for Molecular Simulation, Swinburne University of Technology, PO Box 218 Hawthorn, Victoria 3122 (Australia)

    2014-03-14

    Thermodynamic and diffusion properties of water + methane mixtures in a single liquid phase are studied using NVT molecular dynamics. An extensive comparison is reported for the thermal pressure coefficient, compressibilities, expansion coefficients, heat capacities, Joule-Thomson coefficient, zero frequency speed of sound, and diffusion coefficient at methane concentrations up to 15% in the temperature range of 298–650 K. The simulations reveal a complex concentration dependence of the thermodynamic properties of water + methane mixtures. The compressibilities, heat capacities, and diffusion coefficients decrease with increasing methane concentration, whereas values of the thermal expansion coefficients and speed of sound increase. Increasing methane concentration considerably retards the self-diffusion of both water and methane in the mixture. These effects are caused by changes in hydrogen bond network, solvation shell structure, and dynamics of water molecules induced by the solvation of methane at constant volume conditions.

  16. 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.

  17. 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 ...

  18. Ultrasonic Investigations of Molecular Interaction in Binary Mixtures of Benzyl Benzoate with Acetonitrile and Benzonitrile

    OpenAIRE

    N. Jaya Madhuri; Naidu, P S; Glory, J.; K. Ravindra Prasad

    2011-01-01

    Ultrasonic velocity, density and viscosity have been measured in the binary mixtures of benzyl benzoate with acetonitrile, benzonitrile at three temperatures 30, 40 and 50 °C. From the experimental data, thermodynamic parameters like adiabatic compressibility, internal pressure, enthalpy, activation energy etc., were computed and the molecular interactions were predicted based on the variation of excess parameters in the mixture. Also theoretical evaluation of velocities was made employing th...

  19. Navier-Stokes transport coefficients of $d$-dimensional granular binary mixtures at low density

    OpenAIRE

    Garzo, Vicente; Montanero, Jose Maria

    2006-01-01

    The Navier-Stokes transport coefficients for binary mixtures of smooth inelastic hard disks or spheres under gravity are determined from the Boltzmann kinetic theory by application of the Chapman-Enskog method for states near the local homogeneous cooling state. It is shown that the Navier-Stokes transport coefficients are not affected by the presence of gravity. As in the elastic case, the transport coefficients of the mixture verify a set of coupled linear integral equations that are approx...

  20. Shear viscosity for a heated granular binary mixture at low-density

    OpenAIRE

    Montanero, J. M.; Garzo, V.

    2002-01-01

    The shear viscosity for a heated granular binary mixture of smooth hard spheres at low-density is analyzed. The mixture is heated by the action of an external driving force (Gaussian thermostat) which exactly compensate for cooling effects associated with the dissipation of collisions. The study is made from the Boltzmann kinetic theory, which is solved by using two complementary approaches. First, a normal solution of the Boltzmann equation via the Chapman-Enskog method is obtained up to fir...

  1. Investigation of Binary Mixtures Containing 1-Ethyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)azanide and Ethylene Carbonate

    OpenAIRE

    Hofmann, A.; Migeot, M.; Hanemann, T.

    2016-01-01

    Temperature dependent viscosity, conductivity, and density data of binary mixtures containing ethylene carbonate (EC) and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)azanide (EMIM-TFSA) were determined at atmospheric pressure in a wide temperature range of (20 to 120) °C. Additionally, differential scanning calorimetry (DSC) measurements were performed from (−120 to +100) °C to characterize phase behavior of the mixtures. On the basis of the experimental data it is demonstrated t...

  2. Analytical Solutions for Some Simple Flows of a Binary Mixture of Incompressible Newtonian Fluids

    OpenAIRE

    BARIŞ, Serdar

    2002-01-01

    The problems dealing with some simple flows of a mixture of two incompressible Newtonian fluids have been analysed. By using the theory of binary mixtures of Newtonian fluids, the equations governing the velocity fields are reduced to a system of coupled ordinary differential equations. In the case of non-inertial flow the analytical solutions of these equations have been obtained for the following three problems: (i) the parallel flow with a free surface; (ii) the flow between inter...

  3. The extraction of aromatic amino acids with binary and ternary mixtures of hydrophilic solvents

    Science.gov (United States)

    Mokshina, N. Ya.; Pakhomova, O. A.; Niftaliev, S. I.

    2007-11-01

    The extraction of tyrosine and phenylalanine with binary and ternary mixtures of hydrophilic solvents from aqueous salt solutions was studied, and several tendencies were observed. Simplex-lattice planning of experiment was used for the optimization of the composition of solvent mixtures. It was shown that the extraction systems developed could be employed for the almost complete extraction of tyrosine and phenylalanine from aqueous solutions.

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

    Indian Academy of Sciences (India)

    J D Pandey; J Chhabra; R Dey; V Sanguri; R Verma

    2000-09-01

    When sound waves of high amplitude propagate, several non-linear effects occur. 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 mixtures using Tong and Dong equation at high pressures and = 303.15 K. Thermodynamic method has also been used to calculate the non-linearity parameter after making certain approximations.

  5. Microwave dielectric characterization of binary mixture of formamide with , -dimethylaminoethanol

    Indian Academy of Sciences (India)

    Prabhakar Undre; S N Helambe; S B Jagadale; P W Khirade; S C Mehrotra

    2007-05-01

    Dielectric relaxation measurements of formamide (FMD)–,- dimethylaminoethanol (DMAE) solvent mixtures have been carried out over the entire concentration range using time domain reflectometry technique at 25, 35 and 45° C in thefrequency range of 10 MHz to 20 GHz. The mixtures exhibit a principle dispersion of 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 time (1/)E, Kirkwood correlation factor (eff), activation energy and Bruggeman factor (B) are also calculated to study the solute–solvent interaction.

  6. Prediction of mechanical properties of compacted binary mixtures containing high-dose poorly compressible drug.

    Science.gov (United States)

    Patel, Sarsvatkumar; Bansal, Arvind Kumar

    2011-01-17

    The aim of the study was to develop, compare and validate predictive model for mechanical property of binary systems. The mechanical properties of binary mixtures of ibuprofen (IBN) a poorly compressible high dose drug, were studied in presence of different excipients. The tensile strength of tablets of individual components viz. IBN, microcrystalline cellulose (MCC), and dicalcium phosphate dihydrate (DCP) and binary mixtures of IBN with excipients was measured at various relative densities. Prediction of the mechanical property of binary mixtures, from that of single components, was attempted using Ryshkewitch-Duckworth (R-D) and Percolation theory, by assuming a linear mixing rule or a power law mixing rule. The models were compared, and the best model was proposed based on the distribution of residuals and the Akaike's information criterion. Good predictions were obtained with the power law combined with linear mixing rule, using R-D and Percolation models. The results indicated that the proposed model can well predict the mechanical properties of binary system containing predominantly poorly compressible drug candidate. The predictions of these models and conclusions can be systematically generalized to other pharmaceutical powders.

  7. 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.

  8. 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.

  9. Liquid crystalline behaviour of mixtures of structurally dissimilar mesogens in binary systems

    Indian Academy of Sciences (India)

    Jayrang S Dave; Meera R Menon; Pratik R Patel

    2002-06-01

    We have studied four binary systems comprising four ester components, viz. 4-nitrophenyl-4'--alkoxybenzoates (where -alkoxy is nbutoxy, C4, -hexyloxy, C6, -octyloxy, C8 and -decyloxy, C10) and one azo component, 4--decyloxy phenylazo-4'-isoamyloxy benzene. A variety of mesomorphic properties are observed in these mixtures. The properties of these systems are discussed on the basis of phase diagrams.

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

    NARCIS (Netherlands)

    Glavatskiy, K.S.; Bedeaux, D.

    2010-01-01

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

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

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  12. Interpretation of Association Behavior and Molecular Interactions in Binary Mixtures from Thermoacoustics and Molecular Compression Data

    Science.gov (United States)

    Shukla, Rajeev K.; Kumar, Atul; Srivastava, Urvashi; Srivastava, Kirti; Pandey, Vivek K.

    2016-09-01

    Density and acoustic velocity were measured for binary liquid mixtures of formamide, N-methylacetamide (NMA), dimethylformamide (DMF), and dimethylacetamide (DMA) with acetonitrile at atmospheric pressure and 293.15 K, 298.15 K, 303.15 K, 308.15 K, or 313.15 K over the concentration range 0.12 to 0.97. Models assuming association and nonassociation of the components of the mixtures were used to predict the behavior of the studied liquids, which would typically show weak interactions. The measured properties were fitted to the Redlich-Kister polynomial to estimate the binary coefficients and standard errors. The data were used to study the molecular interactions in the binary mixtures. Furthermore, the McAllister multibody interaction model was used to correlate the properties of the binary liquid mixtures. Testing of the nonassociation and association models for the different systems showed that, compared with the nonassociation model theoretical results, the association model theoretical results were more consistent with the experimental results.

  13. Solitary-wave solutions in binary mixtures of Bose-Einstein condensates under periodic boundary conditions

    Science.gov (United States)

    Smyrnakis, J.; Magiropoulos, M.; Kavoulakis, G. M.; Jackson, A. D.

    2013-01-01

    We derive solitary-wave solutions within the mean-field approximation in quasi-one-dimensional binary mixtures of Bose-Einstein condensates under periodic boundary conditions, for the case of an effective repulsive interatomic interaction. The particular gray-bright solutions that give the global energy minima are determined. Their characteristics and the associated dispersion relation are derived.

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

    NARCIS (Netherlands)

    Samin, Sela; van Roij, Rene

    2015-01-01

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

  15. Ultrasonic study of molecular interaction in binary liquid mixtures at 30°C

    Indian Academy of Sciences (India)

    A Ali; A K Nain

    2002-04-01

    Densities ρ and ultrasonic speeds of the binary mixtures of tetrahydrofuran (THF) with 1-butanol and tert-butanol, at 30°C, over the entire composition range were measured. From these data isentropic compressibility, s, intermolecular free length f, relative association A, acoustic impedance , molar sound speed m, deviations in isentropic compressibility s, and excess volume E were calculated. 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 were discussed.

  16. Biosorption of binary mixtures of Cr(III and Cu(II ions by Sargassum sp

    Directory of Open Access Journals (Sweden)

    Silva E.A.

    2003-01-01

    Full Text Available The adsorption of two metal ions, Cr(III and Cu(II, in single-component and binary systems by Sargassum sp., a brown alga, was studied. Equilibrium batch sorption studies were carried out at 30ºC and pH 3.5. Kinetic tests were done for a binary mixture (chromium + copper for a contact time of 72 hours to guarantee that equilibrium was reached. The monocomponent equilibrium data obtained were analyzed using the Langmuir and Freundlich isotherms. The binary equilibrium data obtained were described using four Langmuir-type and Freundlich isotherms. The F-test showed a statistically significant fit for all binary isotherm models. The parameters for isotherms of the Langmuir-type were used to determine the affinity of one metal for the biosorbent in the presence of another metal. The chromium ion showed a greater affinity for Sargassum sp. than the copper ion.

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

    International Nuclear Information System (INIS)

    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: EC50 48h = 0, 39±0, 04 mg.L-1 for uranium and EC50 48h 1, 86±0, 85 mg.L-1 for selenium. Chronic effects were also studied. Data on fecundity showed an EC10 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)

  18. Transport Properties of operational gas mixtures used at LHC

    OpenAIRE

    Assran, Yasser; Sharma, Archana

    2011-01-01

    This report summarizes some useful data on the transport characteristics of gas mixtures which are required for detection of charged particles in gas detectors. We try to replace Freon used for RPC detector in the CMS experiment with another gas while maintaining the good properties of the Freon gas mixture unchanged. We try to switch to freonless gas mixture because Freon is not a green gas, it is very expensive and its availability is decreasing. Noble gases like Ar, He, Ne and Xe (with som...

  19. Ion mobilities in Xe/Ne and other rare-gas mixtures.

    Science.gov (United States)

    Piscitelli, D; Phelps, A V; de Urquijo, J; Basurto, E; Pitchford, L C

    2003-10-01

    The ion mobility or drift velocity data important for modeling glow discharges in rare gas mixtures are not generally available, nor are the ion-neutral scattering cross sections needed to calculate these data. In this paper we propose a set of cross sections for Xe+ and Ne+ collisions with Xe and Ne atoms. Ion mobilities at 300 K calculated using this cross section set in a Monte Carlo simulation are reported for reduced field strengths, E/N, up to 1500 x 10(-21) V m(2), in pure gases and in Xe/Ne mixtures containing 5% and 20% Xe/Ne, which are mixtures of interest for plasma display panels (PDPs). The calculated Xe+ mobilities depend strongly on the mixture composition, but the Ne+ mobility varies only slightly with increasing Xe in the mixture over the range studied here. The mobilities in pure gases compare well with available experimental values, and mobilities in gas mixtures at low E/N compare well with our recent measurements which will be published separately. Results from these calculations of ion mobilities are used to evaluate the predictions of Blanc's law and of the mixture rule proposed by Mason and Hahn [Phys. Rev. A 5, 438 (1972)] for determining the ion mobilities in mixtures from a knowledge of the mobilities in each of the pure gases. The mixture rule of Mason and Hahn is accurate to better than 10% at high field strengths over a wide range of conditions of interest for modeling PDPs. We conclude that a good estimate of ion mobilities at high E/N in Xe/Ne and other binary rare gas mixtures can be obtained using this mixture rule combined with known values of mobilities in parent gases and with the Langevin form for mobility of rare gas ions ion in other gases. This conclusion is supported by results in Ar/Ne mixtures which are also presented here.

  20. Modelling of associating mixtures for applications in the oil & gas and chemical industries

    DEFF Research Database (Denmark)

    Kontogeorgis, Georgios; Folas, Georgios; Muro Sunè, Nuria;

    2007-01-01

    -polar (non self-associating) compounds it reduces to SRK. The model was first published in 1996 and since then it has been developed and applied with success to binary systems containing water-alkanes and alcohol/glycol/acid-alkanes (both VLE and LLE) as well as ternary and multicomponent (V)LLE for water......-alcohol (glycol)-alkanes and certain acid and amine-containing mixtures. Recent results include glycol-aromatic hydrocarbons including multiphase, multicomponent equilibria and gas hydrate calculations in combination with the van der Waals-Platteeuw model. This article will outline some new applications...... of the model of relevance to the petroleum and chemical industries: high pressure vapor-liquid and liquid-liquid equilibrium in alcohol-containing mixtures, mixtures with gas hydrate inhibitors and mixtures with polar and hydrogen bonding chemicals including organic acids. Some comparisons with conventional...

  1. 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.

  2. Evaluation of binary solvent mixtures for efficient monoacylglycerol production by continuous enzymatic glycerolysis.

    Science.gov (United States)

    Damstrup, Marianne L; Abildskov, Jens; Kiil, Søren; Jensen, Anker D; Sparsø, Flemming V; Xu, Xuebing

    2006-09-20

    This study was aimed at evaluating different binary solvent mixtures for efficient industrial monoacylglycerol (MAG) production by enzymatic glycerolysis. Of all investigated cases, the binary mixture of tert-butanol:tert-pentanol (TB:TP) 80:20 vol % was the most suitable organic medium for continuous enzymatic glycerolysis, ensuring high MAG formation in a short time, reasonable solvent price, and easy handling during distillation/condensation processing. A minimum solvent dosage of 44-54 wt % of the reaction mixture was necessary to achieve high MAG yields of 47-56 wt %, within 20 min. The melting and boiling points of the TB:TP mixture were estimated to be 7 and 85 degrees C, respectively, using thermodynamic models. These predictions were in good agreement with experimentally determined values. In spite of the high reaction efficiency in the binary TB:TP system, the mixture of glycerol and sunflower oil (containing 97.1% triacylglycerol) yielded surprisingly a liquid/liquid phase split behavior even at high temperatures (>80 degrees C). This in contrast to thermodynamic model calculations suggested full miscibility in all proportions. These findings suggest that enhanced reaction efficiency in organic solvent also depends upon aspects other than the system homogeneity such as reduced viscosity, reduced mass transfer limitations, and the accessibility of the substrate to the active site of the enzyme. PMID:16968070

  3. Solid–liquid equilibria of binary mixtures of fluorinated ionic liquids†

    Science.gov (United States)

    Teles, Ana Rita R.; Correia, Helga; Maximo, Guilherme J.; Rebelo, Luís P. N.; Freire, Mara G.; Pereiro, Ana B.; Coutinho, João A. P.

    2016-01-01

    Within ionic liquids, fluorinated ionic liquids (FILs) present unique physico-chemical properties and potential applications in several fields. However, the melting point of these neoteric compounds is usually higher due to the presence of fluorine atoms. This drawback may be resolved by, for instance, mixing different FILs to create eutectic mixtures. In this work, binary mixtures of fluoro-containing and fluorinated ionic liquids were considered with the aim of decreasing their melting temperatures as well as understanding and characterizing these mixtures and their phase transitions. Five FILs were selected, allowing the investigation of four binary mixtures, each of them with a common ion. Their solid–liquid and solid–solid equilibria were studied by differential scanning calorimetry and the non-ideality of the mixtures was investigated. Overall, a variety of solid–liquid equilibria with systems exhibiting eutectic behavior, polymorphs with solid–solid phase transitions, and the formation of intermediate compounds and solid solutions were surprisingly found. In addition to these intriguing behaviours, novel FILs with lower melting temperatures were obtained by the formation of binary systems, thus enlarging the application range of FILs at lower temperatures. PMID:27603428

  4. Solid-liquid equilibria of binary mixtures of fluorinated ionic liquids.

    Science.gov (United States)

    Teles, Ana Rita R; Correia, Helga; Maximo, Guilherme J; Rebelo, Luís P N; Freire, Mara G; Pereiro, Ana B; Coutinho, João A P

    2016-09-28

    Within ionic liquids, fluorinated ionic liquids (FILs) present unique physico-chemical properties and potential applications in several fields. However, the melting point of these neoteric compounds is usually higher due to the presence of fluorine atoms. This drawback may be resolved by, for instance, mixing different FILs to create eutectic mixtures. In this work, binary mixtures of fluoro-containing and fluorinated ionic liquids were considered with the aim of decreasing their melting temperatures as well as understanding and characterizing these mixtures and their phase transitions. Five FILs were selected, allowing the investigation of four binary mixtures, each of them with a common ion. Their solid-liquid and solid-solid equilibria were studied by differential scanning calorimetry and the non-ideality of the mixtures was investigated. Overall, a variety of solid-liquid equilibria with systems exhibiting eutectic behavior, polymorphs with solid-solid phase transitions, and the formation of intermediate compounds and solid solutions were surprisingly found. In addition to these intriguing behaviours, novel FILs with lower melting temperatures were obtained by the formation of binary systems, thus enlarging the application range of FILs at lower temperatures.

  5. Rheology and Structure of Quenched Binary Mixtures Under Oscillatory Shear

    Institute of Scientific and Technical Information of China (English)

    XU Ai-Guo

    2003-01-01

    We applied the D2Q9 BGK lattice Boltzmann method to study the rheology and structure of the phaseseparating binary fluids under oscillatory shear in the diffusive regime. The method is suitable for simulating systemswhose dynamicsis described by the Navier-Stokes equation and convection-diffusion equation. The shear oscillationinduces different rheological patterns from those under steady shear. With the increasing of the frequency of the shearthe system shows more isotropic behavior, while with the decreasing of the frequency we find more configurations similarto those under steady shear. By decreasing the frequency of the shear, the period of the applied flow becomes thesame order of the relaxation time of the shear velocity profile, which is inversely proportional to the viscosity, and moreanisotropic effects become observable. The structure factor and the velocity profile contribute to the understanding ofthe configurations and the kinetic process. Oscillatory shear induces nonlinear pattern of the horizontal velocity profile.Therefore, configurations are found where lamellar order close to the wall coexists with isotropic domains in the middleof the system. For very slow frequencies, the morphology of the domains is characterized by lamellar order everywherethat resembles what happens in the case of steady shear.

  6. Dynamics of binary phase separation in liquid He-3-He-4 mixtures

    Science.gov (United States)

    Hoffer, J. K.; Sinha, D. N.

    1986-01-01

    Binary phase-separation dynamics in liquid mixtures of He-3 and He-4 has been investigated near the tricritical point with laser-light scattering techniques. Rapid decompression of the mixtures results in quenches into the miscibility gap so that both the metastable and unstable (spinodal) regions can be probed. Quenches into the unstable region allowed measurements of the normalized dynamic structure factor S(k,t) that confirm the dynamical scaling hypotheses for spinodal decomposition. Measurements made for concentrations well away from the tricritical value show different behavior and suggest the presence of a spinodal boundary. Forward scattering intensities for shallow quenches probe nucleation phenomena and permit quantitative measurements of anomalous super-cooling as a function of quench rate. Comparisons with data in organic binary mixtures are given.

  7. Dissipative particle dynamics simulation study on the binary mixture phase separation coupled with polymerization.

    Science.gov (United States)

    Liu, Hong; Qian, Hu-Jun; Zhao, Ying; Lu, Zhong-Yuan

    2007-10-14

    The influence of polymerization on the phase separation of binary immiscible mixtures has been investigated by the dissipative particle dynamics simulations in two dimensions. During polymerization, the bulk viscosity increases, which consequently slows down the spinodal decomposition process. The domain size growth is monitored in the simulations. The absence of 23 exponent for inertial hydrodynamic mechanism clearly reflects the suppressing effect of polymerization on the phase separation. Due to the increasing viscosity, the individual phase may be trapped in a metastable stage instead of the lamellar morphology identified for symmetric mixtures. Moreover, the polymerization induced phase separation in the binary miscible mixture has been studied. The domain growth is strongly dependent on the polymerization probability, which is naturally related to the activation energy for polymerization. The observed complex phase separation behavior is attributed to the interplay between the increasing thermodynamic driving force for phase separation and the increasing viscosity that suppresses phase separation as the polymerization proceeds. PMID:17935435

  8. Volumetric properties of binary mixtures of benzene with cyano-based ionic liquids

    Science.gov (United States)

    Gonfa, Girma; Bustam, Mohamad Azmi; Moniruzzaman, Muhammad; Murugesan, Thanabalan

    2014-10-01

    The objective of this study is to investigate the volumetric properties of the binary mixtures comprised benzene and two ionic liquids, 1-butyl-3-methylimidazolium thiocyanate ([BMIM][SCN]) and 1-butyl-3-methyl- imidazolium dicyanamide ([ BMIM ][ N ( CN )2]( . Densities (ρ) and viscosities (μ) of the binary mixtures were measured over a temperature range of 293.15 to 323.15 K and at atmospheric pressure. Excess molar volumes and viscosity deviations were calculated from the experimental densities and viscosities values. The volumetric properties of the mixtures were changed significantly with the change of compositions and temperatures. It was also found that the value of excess molar volume and viscosity deviations were negative (-ve) over the entire range of compositions. The results have been interpreted in terms of molecular interactions of ILs and benzene.

  9. ThermoData Engine (TDE): software implementation of the dynamic data evaluation concept. 3. Binary mixtures.

    Science.gov (United States)

    Diky, Vladimir; Chirico, Robert D; Kazakov, Andrei F; Muzny, Chris D; Frenkel, Michael

    2009-02-01

    ThermoData Engine (TDE) is the first full-scale software implementation of the dynamic data evaluation concept, as reported recently in this journal. The present paper describes the first application of this concept to the evaluation of thermophysical properties for binary chemical systems. Five activity-coefficient models have been implemented for representation of phase-equilibrium data (vapor-liquid, liquid-liquid, and solid-liquid equilibrium): NRTL, UNIQUAC, Van Laar, Margules/Redlich-Kister, and Wilson. Implementation of these models in TDE is fully described. Properties modeled individually are densities, surface tensions, critical temperatures, critical pressures, excess enthalpies, and the transport properties-viscosity and thermal conductivity. Extensions to the class structure of the program are described with emphasis on special features allowing close linkage between mixture and pure-component properties required for implementation of the models. Details of gas-phase models used in conjunction with the activity-coefficient models are shown. Initial implementation of the dynamic data evaluation concept for reactions is demonstrated with evaluation of enthalpies of formation for compounds containing carbon, hydrogen, oxygen, and nitrogen. Directions for future enhancements are outlined. PMID:19434848

  10. Effective ionization coefficients and transport parameters in binary and ultradilute SF6-Ar mixtures using Boltzmann equation analysis

    Science.gov (United States)

    Cekmen, Z. C.; Dincer, M. S.

    2009-07-01

    The effective ionization coefficients and transport parameters such as electron mean energy drift velocity and transverse diffusion coefficient in binary and ultradilute SF6-Ar gas mixtures have been calculated for density reduced electric field strength E/N values from 10 to 400 Td. These calculations have been performed by using the two-term spherical harmonic expansion to obtain the numerical solution of the Boltzmann transport equation based on the finite element method under steady-state Townsend condition. In order to confirm the model and code developed in this study, the Reid ramp model has been used as a benchmark test and then effective ionization coefficients and transport parameters have been evaluated for SF6 contents of 1%, 10%, 25%, 50%, 70% and 100% in the binary mixture. Finally SF6 contents in the ultradilute mixtures of 0.1%, 0.3%, 0.5% and 0.7% are taken into account with the evaluated effective ionizations and transport parameters of electron mean energy, drift velocity and transverse diffusion coefficients.

  11. Low Mach Number Fluctuating Hydrodynamics of Binary Liquid Mixtures

    CERN Document Server

    Nonaka, A J; Bell, J B; Donev, A

    2014-01-01

    Continuing on our previous work [ArXiv:1212.2644], we develop semi-implicit numerical methods for solving low Mach number fluctuating hydrodynamic equations appropriate for modeling diffusive mixing in isothermal mixtures of fluids with different densities and transport coefficients. We treat viscous dissipation implicitly using a recently-developed variable-coefficient Stokes solver [ArXiv:1308.4605]. This allows us to increase the time step size significantly compared to the earlier explicit temporal integrator. For viscous-dominated flows, such as flows at small scales, we develop a scheme for integrating the overdamped limit of the low Mach equations, in which inertia vanishes and the fluid motion can be described by a steady Stokes equation. We also describe how to incorporate advanced higher-order Godunov advection schemes in the numerical method, allowing for the treatment of fluids with high Schmidt number including the vanishing mass diffusion coefficient limit. We incorporate thermal fluctuations in...

  12. Convection in Binary Fluid Mixtures; 2, Localized Traveling Waves

    CERN Document Server

    Barten, W; Kamps, M; Schmitz, R

    1995-01-01

    Nonlinear, spatially localized structures of traveling convection rolls are investigated in quantitative detail as a function of Rayleigh number for two different Soret coupling strengths (separation ratios) with Lewis and Prandtl numbers characterizing ethanol-water mixtures. A finite-difference method was used to solve the full hydrodynamic field equations numerically. Structure and dynamics of these localized traveling waves (LTW) are dominated by the concentration field. Like in the spatially extended convective states ( cf. accompanying paper), the Soret-induced concentration variations strongly influence, via density changes, the buoyancy forces that drive convection. The spatio-temporal properties of this feed-back mechanism, involving boundary layers and concentration plumes, show that LTW's are strongly nonlinear states. Light intensity distributions are determined that can be observed in side-view shadowgraphs. Detailed analyses of all fields are made using colour-coded isoplots, among others. In th...

  13. Excess molar volumes and isentropic compressibilities of binary liquid mixtures containing n-alkanes at 298.15 K

    Indian Academy of Sciences (India)

    V Vyas; T Nautiyal

    2002-10-01

    Excess molar volumes (E) and deviation in isentropic compressibilities (s) have been investigated from the density and speed of sound measurements of six binary liquid mixtures containing -alkanes over the entire range of composition at 298.15 K. Excess molar volume exhibits inversion in sign in one binary mixture, i.e., n-heptane + n-hexane. Remaining five binary mixtures, n-heptane + toluene, cyclohexane + n-heptane, cyclohexane + n-hexane, toluene + nhexane and n-decane + n-hexane show negative excess molar volumes over the whole composition range. However, the large negative values of excess molar volume becomes dominant in toluene + n-hexane mixture. Deviation in isentropic compressibility is negative over the whole range of composition in the case of all the six binary mixtures. Existence of specific intermolecular interactions in the mixtures has been analyzed in terms of excess molar volume and deviation in isentropic compressibility.

  14. Inherent structures of phase-separating binary mixtures: nucleation, spinodal decomposition, and pattern formation.

    Science.gov (United States)

    Sarkar, Sarmistha; Bagchi, Biman

    2011-03-01

    An energy landscape view of phase separation and nonideality in binary mixtures is developed by exploring their potential energy landscape (PEL) as functions of temperature and composition. We employ molecular dynamics simulations to study a model that promotes structure breaking in the solute-solvent parent binary liquid, at low temperatures. The PEL of the system captures the potential energy distribution of the inherent structures (IS) of the system and is obtained by removing the kinetic energy (including that of intermolecular vibrations). The broader distribution of the inherent structure energy for structure breaking liquid than that of the structure making liquid demonstrates the larger role of entropy in stabilizing the parent liquid of the structure breaking type of binary mixtures. At high temperature, although the parent structure of the structure breaking binary mixture is homogenous, the corresponding inherent structure is found to be always phase separated, with a density pattern that exhibits marked correlation with the energy of its inherent structure. Over a broad range of intermediate inherent structure energy, bicontinuous phase separation prevails with interpenetrating stripes as signatures of spinodal decomposition. At low inherent structure energy, the structure is largely phase separated with one interface where as at high inherent structure energy we find nucleation type growth. Interestingly, at low temperature, the average inherent structure energy () exhibits a drop with temperature which signals the onset of crystallization in one of the phases while the other remains in the liquid state. The nonideal composition dependence of viscosity is anticorrelated with average inherent structure energy. PMID:21517506

  15. Inherent structures of phase-separating binary mixtures: Nucleation, spinodal decomposition, and pattern formation

    Science.gov (United States)

    Sarkar, Sarmistha; Bagchi, Biman

    2011-03-01

    An energy landscape view of phase separation and nonideality in binary mixtures is developed by exploring their potential energy landscape (PEL) as functions of temperature and composition. We employ molecular dynamics simulations to study a model that promotes structure breaking in the solute-solvent parent binary liquid, at low temperatures. The PEL of the system captures the potential energy distribution of the inherent structures (IS) of the system and is obtained by removing the kinetic energy (including that of intermolecular vibrations). The broader distribution of the inherent structure energy for structure breaking liquid than that of the structure making liquid demonstrates the larger role of entropy in stabilizing the parent liquid of the structure breaking type of binary mixtures. At high temperature, although the parent structure of the structure breaking binary mixture is homogenous, the corresponding inherent structure is found to be always phase separated, with a density pattern that exhibits marked correlation with the energy of its inherent structure. Over a broad range of intermediate inherent structure energy, bicontinuous phase separation prevails with interpenetrating stripes as signatures of spinodal decomposition. At low inherent structure energy, the structure is largely phase separated with one interface where as at high inherent structure energy we find nucleation type growth. Interestingly, at low temperature, the average inherent structure energy () exhibits a drop with temperature which signals the onset of crystallization in one of the phases while the other remains in the liquid state. The nonideal composition dependence of viscosity is anticorrelated with average inherent structure energy.

  16. Viscosity and thermal conductivity of moderately dense gas mixtures.

    Science.gov (United States)

    Wakeham, W. A.; Kestin, J.; Mason, E. A.; Sandler, S. I.

    1972-01-01

    Derivation of a simple, semitheoretical expression for the initial density dependence of the viscosity and thermal conductivity of gaseous mixtures in terms of the appropriate properties of the pure components and of their interaction quantities. The derivation is based on Enskog's theory of dense gases and yields an equation in which the composition dependence of the linear factor in the density expansion is explicit. The interaction quantities are directly related to those of the mixture extrapolated to zero density and to a universal function valid for all gases. The reliability of the formulation is assessed with respect to the viscosity of several binary mixtures. It is found that the calculated viscosities of binary mixtures agree with the experimental data with a precision which is comparable to that of the most precise measurements.

  17. Applicability of linearized Dusty Gas Model for multicomponent diffusion of gas mixtures in porous solids

    Directory of Open Access Journals (Sweden)

    Marković Jelena

    2007-01-01

    Full Text Available The transport of gaseous components through porous media could be described according to the well-known Fick model and its modifications. It is also known that Fick’s law is not suitable for predicting the fluxes in multicomponent gas mixtures, excluding binary mixtures. This model is still frequently used in chemical engineering because of its simplicity. Unfortunately, besides the Fick’s model there is no generally accepted model for mass transport through porous media (membranes, catalysts etc.. Numerous studies on transport through porous media reveal that Dusty Gas Model (DGM is superior in its ability to predict fluxes in multicomponent mixtures. Its wider application is limited by more complicated calculation procedures comparing to Fick’s model. It should be noted that there were efforts to simplify DGM in order to obtain satisfactory accurate results. In this paper linearized DGM, as the simplest form of DGM, is tested under conditions of zero system pressure drop, small pressure drop, and different temperatures. Published experimental data are used in testing the accuracy of the linearized procedure. It is shown that this simplified procedure is accurate enough compared to the standard more complicated calculations.

  18. Segregation characteristics of irregular binaries in gas solid fluidized beds——An ANN-approach

    Institute of Scientific and Technical Information of China (English)

    Abanti Sahoo; Gopendra Kishore Roy

    2008-01-01

    Binary mixtures of irregular materials of different particle sizes and/or particle densities are fluidized in a 15-cm diameter column with a perforated plate distributor. An attempt has been made in this work to determine the segregation characteristics of jetsam particles for both the homogeneous and heterogeneous binary mixtures in terms of segregation distance by correlating it to the various system parameters, viz. initial static bed height, height of a layer of particles above the bottom grid, superficial gas velocity and average particle size and/or particle densities of the mixture through the dimensional analysis. Correlation on the basis of Artificial Neural Network approach has also been developed with the above system parameters thereby authenticating the development of correlation by the former approach. The calculated values of the segregation distance obtained for both the homogeneous and heterogeneous binary mixtures from both the types of fluidized beds (i. e. under the static bed condition and the fluidized bed condition) have also been compared with each other.

  19. Multiphase Binary Mixture Flows in Porous Media in a Wide Pressure and Temperature Range Including Critical Conditions

    Science.gov (United States)

    Afanasyev, A.

    2011-12-01

    Multiphase flows in porous media with a transition between sub- and supercritical thermodynamic conditions occur in many natural and technological processes (e.g. in deep regions of geothermal reservoirs where temperature reaches critical point of water or in gas-condensate fields where subject to critical conditions retrograde condensation occurs and even in underground carbon dioxide sequestration processes at high formation pressure). Simulation of these processes is complicated due to degeneration of conservation laws under critical conditions and requires non-classical mathematical models and methods. A new mathematical model is proposed for efficient simulation of binary mixture flows in a wide range of pressures and temperatures that includes critical conditions. The distinctive feature of the model lies in the methodology for mixture properties determination. Transport equations and Darcy law are solved together with calculation of the entropy maximum that is reached in thermodynamic equilibrium and determines mixture composition. To define and solve the problem only one function - mixture thermodynamic potential - is required. Such approach allows determination not only single-phase states and two-phase states of liquid-gas type as in classical models but also two-phase states of liquid-liquid type and three-phase states. The proposed mixture model was implemented in MUFITS (Multiphase Filtration Transport Simulator) code for hydrodynamic simulations. As opposed to classical approaches pressure, enthalpy and composition variables together with fully implicit method and cascade procedure are used. The code is capable of unstructured grids, heterogeneous porous media, relative permeability and capillary pressure dependence on temperature and pressure, multiphase diffusion, optional number of sink and sources, etc. There is an additional module for mixture properties specification. The starting point for the simulation is a cubic equation of state that is

  20. Composition dependent non-ideality in aqueous binary mixtures as a signature of avoided spinodal decomposition

    Indian Academy of Sciences (India)

    Sarmistha Sarkar; Saikat Banerjee; Susmita Roy; Rikhia Ghosh; Partha Pratim Ray; Biman Bagchi

    2015-01-01

    We explore the potential energy landscape of structure breaking binary mixtures (SBBM) where two constituents dislike each other, yet remain macroscopically homogeneous at intermediate to high temperatures. Interestingly, we find that the origin of strong composition dependent non-ideal behaviour lies in its phase separated inherent structure. The inherent structure (IS) of SBBM exhibits bi-continuous phase as is usually formed during spinodal decomposition.We draw analogy of this correlation between non-ideality and phase separation in IS to explain observation of non-ideality in real aqueous mixtures of small amphiphilic solutes, containing both hydrophilic and hydrophobic groups. Although we have not been able to obtain IS of these liquids, we find that even at room temperature these liquids sustain formation of fluctuating, transient bicontinuous phase, with limited lifetime ( ≲ 20 ps). While in the model (A, B) binary mixture, the non-ideal composition dependence can be considered as a fluctuation from a phase separated state, a similar scenario is expected to be responsible for the unusually strong non-ideality in these aqueous binary mixtures.

  1. Effect of repeated presentation on sweetness intensity of binary and ternary mixtures of sweeteners.

    Science.gov (United States)

    Schiffman, Susan S; Sattely-Miller, Elizabeth A; Graham, Brevick G; Zervakis, Jennifer; Butchko, Harriett H; Stargel, W Wayne

    2003-03-01

    The purpose of the present study was to determine the effect of repeated presentation of the same sweet stimulus on sweetness intensity ratings. The sweet stimuli tested in this study were binary and ternary blends of 14 sweeteners that varied widely in chemical structure. A trained panel evaluated the sweetness intensity over four sips of a given mixture presented at 30 s intervals. The individual components in the binary sweetener combinations were intensity-anchored with 5% sucrose, while the individual sweeteners in the ternary mixtures were intensity-anchored with 3% sucrose (according to formulae developed previously). Each self-mixture was also evaluated (e.g. acesulfame-K-acesulfame-K). The main finding of this study was that mixtures consisting of two or three different sweeteners exhibited less reduction in sweetness intensity over four repeated sips than a single sweetener at an equivalent sweetness level. Furthermore, ternary combinations tended to be slightly more effective than binary combinations at lessening the effect of repeated exposure to a given sweet stimulus. These findings suggest that the decline in sweetness intensity experienced over repeated exposure to a sweet stimulus could be reduced by the blending of sweeteners. PMID:12714444

  2. 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.

  3. Density functional theory of gas–liquid phase separation in dilute binary mixtures

    Science.gov (United States)

    Okamoto, Ryuichi; Onuki, Akira

    2016-06-01

    We examine statics and dynamics of phase-separated states of dilute binary mixtures using density functional theory. In our systems, the difference of the solvation chemical potential between liquid and gas Δ {μ\\text{s}} (the Gibbs energy of transfer) is considerably larger than the thermal energy {{k}\\text{B}}T for each solute particle and the attractive interaction among the solute particles is weaker than that among the solvent particles. In these conditions, the saturated vapor pressure increases by {{k}\\text{B}}Tn2\\ell\\exp ≤ft(Δ {μ\\text{s}}/{{k}\\text{B}}T\\right) , where n2\\ell is the solute density added in liquid. For \\exp ≤ft(Δ {μ\\text{s}}/{{k}\\text{B}}T\\right)\\gg 1 , phase separation is induced at low solute densities in liquid and the new phase remains in gaseous states, even when the liquid pressure is outside the coexistence curve of the solvent. This explains the widely observed formation of stable nanobubbles in ambient water with a dissolved gas. We calculate the density and stress profiles across planar and spherical interfaces, where the surface tension decreases with increasing interfacial solute adsorption. We realize stable solute-rich bubbles with radius about 30 nm, which minimize the free energy functional. We then study dynamics around such a bubble after a decompression of the surrounding liquid, where the bubble undergoes a damped oscillation. In addition, we present some exact and approximate expressions for the surface tension and the interfacial stress tensor.

  4. Modelling phase equilibria for acid gas mixtures using the CPA equation of state. Part V: Multicomponent mixtures containing CO2 and alcohols

    DEFF Research Database (Denmark)

    Tsivintzelis, Ioannis; Kontogeorgis, Georgios M.

    2015-01-01

    The Cubic plus association (CPA) equation of state has been previously applied to a variety of binary systems containing CO2 with alkanes, water, alcohols and glycols as well as a few multicomponent mixtures (with triethylene glycol, water and methane). In this study, we evaluate the performance...... of CPA for ternary and multicomponent CO2 mixtures containing alcohols (methanol, ethanol or propanol) water and hydrocarbons. This work belongs to a series of studies aiming to arrive in a single "engineering approach" for applying CPA to acid gas mixtures, without introducing significant changes...

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

    Energy Technology Data Exchange (ETDEWEB)

    Mejia, Andres, E-mail: amejia@udec.cl [Departamento de Ingenieria Quimica, Universidad de Concepcion, P.O. Box 160-C, Correo 3, Concepcion (Chile); Cartes, Marcela [Departamento de Ingenieria Quimica, Universidad de Concepcion, P.O. Box 160-C, Correo 3, Concepcion (Chile); Segura, Hugo, E-mail: hsegura@udec.cl [Departamento de Ingenieria Quimica, Universidad de Concepcion, P.O. Box 160-C, Correo 3, Concepcion (Chile)

    2011-09-15

    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.

  6. Transport Properties of operational gas mixtures used at LHC

    CERN Document Server

    Assran, Yasser

    2011-01-01

    This report summarizes some useful data on the transport characteristics of gas mixtures which are required for detection of charged particles in gas detectors. We try to replace Freon used for RPC detector in the CMS experiment with another gas while maintaining the good properties of the Freon gas mixture unchanged. We try to switch to freonless gas mixture because Freon is not a green gas, it is very expensive and its availability is decreasing. Noble gases like Ar, He, Ne and Xe (with some quenchers like carbon dioxide, methane, ethane and isobutene) are investigated. Transport parameters like drift velocity, diffusion, Townsend coefficient, attachment coefficient and Lorentz angle are computed using Garfield software for different gas mixtures and compared with experimental data.

  7. Thermophysical properties of CF4/O2 and SF6/O2 gas mixtures

    Science.gov (United States)

    Damyanova, M.; Hohm, U.; Balabanova, E.; Barton, D.

    2016-03-01

    Fitting formulae are presented for the calculation of the second interaction virial coefficients, mixture viscosities and binary diffusion coefficients for CF4/O2 and SF6/O2 gas mixtures in the temperature range between 200 K and 1000 K. The data recommended are obtained from the isotropic (n-6) Lennard-Jones intermolecular interaction potentials of the pure substances by using the Hohm-Zarkova-Damyanova mixing rules. In general, a good agreement is observed between our results and the experimental and theoretical data found in the literature.

  8. Synergism and Combinatorial Coding for Binary Odor Mixture Perception in Drosophila.

    Science.gov (United States)

    Kundu, Srikanya; Ganguly, Anindya; Chakraborty, Tuhin Subhra; Kumar, Arun; Siddiqi, Obaid

    2016-01-01

    Most odors in the natural environment are mixtures of several compounds. Olfactory receptors housed in the olfactory sensory neurons detect these odors and transmit the information to the brain, leading to decision-making. But whether the olfactory system detects the ingredients of a mixture separately or treats mixtures as different entities is not well understood. Using Drosophila melanogaster as a model system, we have demonstrated that fruit flies perceive binary odor mixtures in a manner that is heavily dependent on both the proportion and the degree of dilution of the components, suggesting a combinatorial coding at the peripheral level. This coding strategy appears to be receptor specific and is independent of interneuronal interactions. PMID:27588303

  9. Effects of a temperature-dependent viscosity on thermal convection in binary mixtures

    Science.gov (United States)

    Hilt, Markus; Glässl, Martin; Zimmermann, Walter

    2014-05-01

    We investigate the effect of a temperature-dependent viscosity on the onset of thermal convection in a horizontal layer of a binary fluid mixture that is heated from below. For an exponential temperature dependence of the viscosity, we find, in binary mixtures as a function of a positive separation ratio ψ and beyond a certain viscosity contrast, a discontinuous transition between two stationary convection modes having different wavelengths. In the range of negative values of the separation ratio ψ, a (continuous or discontinuous) transition from an oscillatory to a stationary onset of convection occurs beyond a certain viscosity contrast, and for large values of the viscosity ratio, the oscillatory onset of convection is suppressed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ashwin S S; Sastry, Srikanth [Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur Campus, Bangalore 560064 (India)

    2003-03-26

    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.

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

    International Nuclear Information System (INIS)

    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.

  12. Preferential solvation of lysozyme in dimethyl sulfoxide/water binary mixture probed by terahertz spectroscopy.

    Science.gov (United States)

    Das, Dipak Kumar; Patra, Animesh; Mitra, Rajib Kumar

    2016-09-01

    We report the changes in the hydration dynamics around a model protein hen egg white lysozyme (HEWL) in water-dimethyl sulfoxide (DMSO) binary mixture using THz time domain spectroscopy (TTDS) technique. DMSO molecules get preferentially solvated at the protein surface, as indicated by circular dichroism (CD) and Fourier transform infrared (FTIR) study in the mid-infrared region, resulting in a conformational change in the protein, which consequently modifies the associated hydration dynamics. As a control we also study the collective hydration dynamics of water-DMSO binary mixture and it is found that it follows a non-ideal behavior owing to the formation of DMSO-water clusters. It is observed that the cooperative dynamics of water at the protein surface does follow the DMSO-mediated conformational modulation of the protein. PMID:27372901

  13. Total Reflux Operation of Multivessel Batch Distillation for Separation of Binary Mixtures

    Institute of Scientific and Technical Information of China (English)

    唐克; 白鹏; 李广忠

    2014-01-01

    Multivessel batch distillation (MVBD) is mainly used to separate mixtures with more than two compo-nents. In this article, a new operation mode with MVBD is proposed for separation of binary mixtures under total reflux. A mathematic model is setup for the simulation. The proposed operation policy and the regular operation with constant reflux are compared theoretically and experimentally. The results show that the new operation mode has great advantages in time saving and operation flexibility. MVBD presents great potential for separation with high efficiency.

  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. 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...... four temperature-independent parameters are required in order to describe the behavior of diffusion coefficients at different temperatures. The physical meaning of the parameters is analyzed. This makes it possible to reduce further their number to just two parameters for described mixtures with polar...

  16. Estimation of Thermodynamic Properties of Binary Liquid Mixtures on the Basis of Statistical Mechanical Theories

    Directory of Open Access Journals (Sweden)

    J. D. Pandey

    2012-12-01

    Full Text Available Thermodynamic properties of liquids and liquid mixtures play very important role in understanding the nature of molecular interactions occurring in the system. In the present work different thermodynamic properties of 15 pure liquids and 34 equimolar binary liquid mixtures of benzene, toluene, p-xylene, chlorobenzene and 1-chloronaphthalene with linear and branched alkanes have been computed with the help of Flory’s statistical theory (FST, Hard sphere equation of state (HSE and Hole theory (HT simultaneously. The calculated values are compared with the experimental findings collected from literature and quite satisfactory results are obtained.

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

    OpenAIRE

    I. Binas; I.Mryglod

    2009-01-01

    Self-diffusion coefficients of a binary fluid mixture with components differing only in their particle masses are studied, in particular the case when mass ratio μ of light and heavy particles tends to zero. These coefficients were calculated within the memory function formalism, using the systematic subsequence of approximations for the relaxation times of velocity autocorrelation function. We obtained a general relation for the self-diffusion coefficients which show polynomial dependence on...

  18. 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.

  19. Attractive Interaction Between Pulses in a Model for Binary-Mixture Convection

    CERN Document Server

    Riecke, H

    1995-01-01

    Recent experiments on convection in binary mixtures have shown that the interaction between localized waves (pulses) can be repulsive as well as {\\it attractive} and depends strongly on the relative {\\it orientation} of the pulses. It is demonstrated that the concentration mode, which is characteristic of the extended Ginzburg-Landau equations introduced recently, allows a natural understanding of that result. Within the standard complex Ginzburg-Landau equation this would not be possible.

  20. Decomposition driven interface evolution for layers of binary mixtures: I. Model derivation and stratified base states

    OpenAIRE

    Thiele, Uwe; Madruga Sánchez, Santiago; Frastia, Lubor

    2007-01-01

    A dynamical model is proposed to describe the coupled decomposition and profile evolution of a free surface film of a binary mixture. An example is a thin film of a polymer blend on a solid substrate undergoing simultaneous phase separation and dewetting. The model is based on model-H describing the coupled transport of the mass of one component (convective Cahn-Hilliard equation) and momentum (Navier-Stokes-Korteweg equations) supplemented by appropriate boundary conditions at the solid subs...

  1. Lattice Boltzmann simulations of segregating binary fluid mixtures in shear flow

    OpenAIRE

    Lamura, A.; Gonnella, G.

    2000-01-01

    We apply lattice Boltzmann method to study the phase separation of a two-dimensional binary fluid mixture in shear flow. The algorithm can simulate systems described by the Navier-Stokes and convection-diffusion equations. We propose a new scheme for imposing the shear flow which has the advantage of preserving mass and momentum conservation on the boundary walls without introducing slip velocities. Our main results concern the presence of two typical lenght scales in the phase separation pro...

  2. Spinodal decomposition of a binary mixture in an uniform shear flow

    OpenAIRE

    Corberi, F.; Gonnella, G.; Lamura, A.

    1998-01-01

    Results are presented for the phase separation process of a binary mixture subject to an uniform shear flow quenched from a disordered to a homogeneous ordered phase. The kinetics of the process is described in the context of the time-dependent Ginzburg-Landau equation with an external velocity term. The one-loop approximation is used to study the evolution of the model. We show that the structure factor obeys a generalized dynamical scaling. The domains grow with different typical lengthscal...

  3. Thermo Physical Properties for Binary Mixture of Dimethylsulfoxide and Isopropylbenzene at Various Temperatures

    OpenAIRE

    Maninder Kumar; V. K. Rattan

    2013-01-01

    Density, refractive index, speed of sound, and viscosity have been measured of binary mixture dimethylsulfoxide (DMSO) + isopropylbenzene (CUMENE) over the whole composition range at 298.15, 303.15, 308.15, and 313.15 K and atmospheric pressure. From these experimental measurements the excess molar volume, deviations in viscosity, molar refractivity, speed of sound, and isentropic compressibility have been calculated. These deviations have been correlated by a polynomial Redlich-Kister equati...

  4. Uphill diffusion and overshooting in the adsorption of binary mixtures in nanoporous solids

    OpenAIRE

    Lauerer, Alexander; Binder, Tomas; Chmelik, Christian; Miersemann, Erich; Haase, Jürgen; Ruthven, Douglas M.; Kärger, Jörg

    2015-01-01

    Under certain conditions, during binary mixture adsorption in nanoporous hosts, the concentration of one component may temporarily exceed its equilibrium value. This implies that, in contrast to Fick's Law, molecules must diffuse in the direction of increasing rather than decreasing concentration. Although this phenomenon of ‘overshooting' has been observed previously, it is only recently, using microimaging techniques, that diffusive fluxes in the interior of nanoporous materials have become...

  5. Evolution of binary seeds in collapsing protostellar gas clouds

    CERN Document Server

    Satsuka, Tatsuya; Tanaka, Suguru; Nagamine, Kentaro

    2016-01-01

    We perform three dimensional smoothed particle hydrodynamics (SPH) simulations of gas accretion onto the seeds of binary stars to investigate their short-term evolution. Our simulation setup is more realistic compared to the previous works by taking into account of dynamically evolving envelope with non-uniform distribution of gas density and angular momentum of accreting flow. Our initial condition includes a seed binary and a surrounding gas envelope, modelling the phase of core collapse of gas cloud when the fragmentation has already occurred. We assume that the seed binary has no eccentricity and no growth by gas accretion. The envelope is assumed to be an isothermal gas with no self-gravity. We run multiple simulations with different values of initial mass ratio $q_0$ (the ratio of secondary over primary mass) and gas temperature, and find a critical value of $q_{\\rm c} = 0.25$ which distinguishes the later evolution of mass ratio $q$ as a function of time. If $q_0 \\ga q_{\\rm c}$, the secondary seed grow...

  6. Studies on the atomic capture of stopped negative pions in binary mixtures of /sup 3/He with other gases

    Energy Technology Data Exchange (ETDEWEB)

    Bannikov, A.V.; Levay, B.; Petrukhin, V.I.; Vasilyev, V.A. (Joint Inst. for Nuclear Research, Dubna (USSR)); Kochenda, L.M.; Markov, A.A.; Medvedev, V.I.; Sokolov, G.L.; Strakovsky, I.I. (Leningrad Nuclear Physics Inst., Gatchina (USSR)); Horvath, D. (Hungarian Academy of Sciences, Budapest. Central Research Inst. for Physics)

    1983-07-25

    Systematic experimental study has been carried out on the atomic capture of negative pions by /sup 3/He in binary gas mixtures of /sup 3/He + Z, where Z is Ne, Ar, Kr, Xe, N/sub 2/, O/sub 2/, CO/sub 2/ and SF/sub 6/. The results are analysed in the framework of a phenomenological model. It is shown that there is no pion transfer from the /sup 3/He..pi../sup -/ mesic atoms to the heavier Z-atoms. The probabilities of pion capture in the various atoms of the mixtures are found to be proportional to the atomic concentraions, thereby excluding the possibility of a concentration dependence in the atomic capture ratio A(Z//sup 3/He). In contradiction to previous assumptions the probability of pion capture into an atomic orbit is not proportional to the stopping power of the components of the mixture. The atomic capture ratio of pions in a /sup 3/He + /sup 4/He mixture is A(/sup 4/He//sup 3/He) = 0.75 +- 0.13, which might be the indication of an isotopic effect. The branching ratio for the charge-exchange reaction at rest ..pi../sup -/ + /sup 3/He -> ..pi../sup 0/ + /sup 3/H) is found to be 0.128 +- 0.012.

  7. Studies on the atomic capture of stopped negative pions in binary mixtures of /sup 3/He with other gases

    Energy Technology Data Exchange (ETDEWEB)

    Bannikov, A.V.; Levay, B.; Petrukhin, V.I.; Vasilyev, V.A. (Joint Inst. for Nuclear Research, Dubna (USSR)); Kochenda, L.M.; Markov, A.A.; Medvedev, V.I.; Sokolov, G.L.; Strakovsky, I.I. (Leningrad Nuclear Physics Inst., Gatchina (USSR)); Horvath, D. (Hungarian Academy of Sciences, Budapest. Central Research Inst. for Physics)

    1983-07-25

    Systematic experimental study has been carried out on the atomic capture of negative pions by /sup 3/He in binary gas mixtures of /sup 3/He + Z, where Z is Ne, Ar, Kr, Xe, N/sub 2/, O/sub 2/, CO/sub 2/ and SF/sub 6/. The results are analyzed in the framework of a phenomenological model. It is shown that there is no pion transfer from the /sup 3/He..pi../sup -/ mesic atoms to the heavier Z-atoms. The probabilities of pion capture in the various atoms of the mixtures are found to be proportional to the atomic concentraions, thereby excluding the possibility of a concentration dependence in the atomic capture ratio A(Z//sup 3/He). In contradiction to previous assumptions the probability of pion capture into an atomic orbit is not proportional to the stopping power of the components of the mixture. The atomic capture ratio of pions in a /sup 3/He + /sup 4/He mixture is A(/sup 4/He//sup 3/He) = 0.75 +- 0.13, which might be the indication of an isotopic effect. The branching ratio for the charge-exchange reaction at rest ..pi../sup -/ + /sup 3/He -> ..pi../sup 0/ + /sup 3/H is found to be 0.128 +- 0.012.

  8. 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.

  9. Picosecond solvation dynamics—A potential viewer of DMSO—Water binary mixtures

    Science.gov (United States)

    Banik, Debasis; Kundu, Niloy; Kuchlyan, Jagannath; Roy, Arpita; Banerjee, Chiranjib; Ghosh, Surajit; Sarkar, Nilmoni

    2015-02-01

    In this work, we have investigated the composition dependent anomalous behavior of dimethyl sulfoxide (DMSO)-water binary mixture by collecting the ultrafast solvent relaxation response around a well known solvation probe Coumarin 480 (C480) by using a femtosecond fluorescence up-conversion spectrometer. Recent molecular dynamics simulations have predicted two anomalous regions of DMSO-water binary mixture. Particularly, these studies encourage us to investigate the anomalies from experimental background. DMSO-water binary mixture has repeatedly given evidences of its dual anomalous nature in front of our systematic investigation through steady-state and time-resolved measurements. We have calculated average solvation times of C480 by two individual well-known methods, among them first one is spectral-reconstruction method and another one is single-wavelength measurement method. The results of both the methods roughly indicate that solvation time of C480 reaches maxima in the mole fraction of DMSO XD = 0.12-0.17 and XD = 0.27-0.35, respectively. Among them, the second region (XD = 0.27-0.35) is very common as most of the thermodynamic properties exhibit deviation in this range. Most probably, the anomalous solvation trend in this region is fully guided by the shear viscosity of the medium. However, the first region is the most interesting one. In this region due to formation of strongly hydrogen bonded 1DMSO:2H2O complexes, hydration around the probe C480 decreases, as a result of which solvation time increases.

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

    International Nuclear Information System (INIS)

    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

  11. Joint toxic action of binary metal mixtures of copper, manganese and nickel to Paronychiurus kimi (Collembola).

    Science.gov (United States)

    Son, Jino; Lee, Yun-Sik; Kim, Yongeun; Shin, Key-Il; Hyun, Seunghun; Cho, Kijong

    2016-10-01

    The joint toxic effects of binary metal mixtures of copper (Cu), manganese (Mn) and nickel (Ni) on reproduction of Paronhchiurus kimi (Lee) was evaluated using a toxic unit (TU) approach by judging additivity across a range of effect levels (10-90%). For all metal mixtures, the joint toxic effects of metal mixtures on reproduction of P. kimi decreased in a TU-dependent manner. The joint toxic effects of metal mixtures also changed from less than additive to more than additive at an effect level lower than or equal to 50%, while a more than additive toxic effects were apparent at higher effect levels. These results indicate that the joint toxicity of metal mixtures is substantially different from that of individual metals based on additivity. Moreover, the close relationship of toxicity to effect level suggests that it is necessary to encompass a whole range of effect levels rather than a specific effect level when judging mixture toxicity. In conclusion, the less than additive toxicity at low effect levels suggests that the additivity assumption is sufficiently conservative to warrant predicting joint toxicity of metal mixtures, which may give an additional margin of safety when setting soil quality standards for ecological risk assessment. PMID:27318557

  12. Composition and thermal analysis of binary mixtures of mee fat and palm stearin.

    Science.gov (United States)

    Abdul Manaf, Yanty Noorziana; Nazrim Marikkar, Jalaldeen Mohammed; Musthafa, Shuhaimi; Saari, Miskandar Mat

    2014-01-01

    Seed fat of Madhuca longifolia known as mee fat (MF) has been considered as a potential plant fat for producing fat mixture to simulate the properties of lard. A study was carried out to evaluate the effect of addition of palm stearin (PS) on the solidification behavior of MF to formulate a mixture to become similar in solidification characteristics of lard. Three fat mixtures were prepared by blending MF with palm stearin PS in different ratios: MF:PS (99.5:0.5), MF:PS (99:1), MF:PS (98:2) (w/w), and identified by the mass ratio of MF to PS. The fat mixtures were compared with lard in terms of their fatty acid and triacylglycerol compositions, differential scanning calorimetric (DSC) thermal profiles and solid fat content (SFC) characteristics. Results showed that there were considerable differences between lard and MF:PS fat mixtures with regard to fatty acid and triacylglycerol compositions. The increasing proportion of PS in MF:PS fat mixtures caused a general increase in SFC at different temperatures with respect to the SFC profile of native MF. Of the three binary mixtures, MF:PS (99:1) was found to show the least difference to lard in terms of SFC values throughout the temperature range. PMID:24671022

  13. Composition and thermal analysis of binary mixtures of mee fat and palm stearin.

    Science.gov (United States)

    Abdul Manaf, Yanty Noorziana; Nazrim Marikkar, Jalaldeen Mohammed; Musthafa, Shuhaimi; Saari, Miskandar Mat

    2014-01-01

    Seed fat of Madhuca longifolia known as mee fat (MF) has been considered as a potential plant fat for producing fat mixture to simulate the properties of lard. A study was carried out to evaluate the effect of addition of palm stearin (PS) on the solidification behavior of MF to formulate a mixture to become similar in solidification characteristics of lard. Three fat mixtures were prepared by blending MF with palm stearin PS in different ratios: MF:PS (99.5:0.5), MF:PS (99:1), MF:PS (98:2) (w/w), and identified by the mass ratio of MF to PS. The fat mixtures were compared with lard in terms of their fatty acid and triacylglycerol compositions, differential scanning calorimetric (DSC) thermal profiles and solid fat content (SFC) characteristics. Results showed that there were considerable differences between lard and MF:PS fat mixtures with regard to fatty acid and triacylglycerol compositions. The increasing proportion of PS in MF:PS fat mixtures caused a general increase in SFC at different temperatures with respect to the SFC profile of native MF. Of the three binary mixtures, MF:PS (99:1) was found to show the least difference to lard in terms of SFC values throughout the temperature range.

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

    Science.gov (United States)

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

    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 0.1mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10mg/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. PMID:26971216

  15. 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

  16. Effects of Binary Mixtures of Inducers (Toluene Analogs) and of Metals on Bioluminescence Induction of a Recombinant Bioreporter Strain

    OpenAIRE

    In Chul Kong

    2014-01-01

    This paper investigated the effects of binary mixtures of bioluminescence inducers (toluene, xylene isomers, m-toluate) and of metals (Cu, Cd, As(III), As(V), and Cr) on bioluminescence activity of recombinant (Pm-lux) strain KG1206. Different responses and sensitivities were observed depending on the types and concentrations of mixtures of inducers or metals. In the case of inducer mixtures, antagonistic and synergistic modes of action were observed, whereas metal mixtures showed all three m...

  17. Effect of chain length of alcohol on thermodynamic properties of their binary mixtures with benzylalcohol

    International Nuclear Information System (INIS)

    Highlights: • ρ and u have been measured for binary mixtures of benzylalcohol with 1-alkanols. • Experimental speed of sound data analyzed in terms of CFT and FLT. • VE for benzylalcohol with studied 1-alcohols are positive while κSE are negative. - Abstract: Densities (ρ) of pure liquids and their mixtures have been measured over the entire composition range for the binary mixtures of benzylalcohol with 1-heptanol, 1-octanol, 1-nonanol and 1-decanol at 298.15 K to 313.15 K and at atmospheric pressure by using Rudolph Research Analytical Digital Density Meter (DDM-2911 model). Further, the speed of sound (u) for the above said mixtures were also measured at 303.15 K and 313.15 K. The experimental density data were used to compute excess molar volumes (VE) and compared with predictive expression proposed by Redlich–Kister equation. Excess speed of sound (uE), isentropic compressibility (κS) and excess isentropic compressibilities (κSE) were evaluated from experimental sound velocity and density data. Moreover, the experimental speed of sound data was compared in terms of theoretical models proposed by Schaaff's collision factor theory (CFT) and Jacobson's free length theory (FLT). The experimental results were discussed in terms of intermolecular interactions between component molecules

  18. Effect of chain length of alcohol on thermodynamic properties of their binary mixtures with benzylalcohol

    Energy Technology Data Exchange (ETDEWEB)

    Venkatramana, L. [Department of Chemistry, P.V.K.N. Govt. Degree and P.G. College, Chittoor 517001, A.P. (India); Sivakumar, K. [Department of Chemistry, S.V. Arts Degree and P.G. College (T.T.D' S), Tirupati 517502, A.P. (India); Gardas, R.L., E-mail: gardas@iitm.ac.in [Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036 (India); Reddy, K. Dayananda, E-mail: ramanapvkn@gmail.com [Department of Chemistry, P.V.K.N. Govt. Degree and P.G. College, Chittoor 517001, A.P. (India)

    2014-04-01

    Highlights: • ρ and u have been measured for binary mixtures of benzylalcohol with 1-alkanols. • Experimental speed of sound data analyzed in terms of CFT and FLT. • V{sup E} for benzylalcohol with studied 1-alcohols are positive while κ{sub S}{sup E} are negative. - Abstract: Densities (ρ) of pure liquids and their mixtures have been measured over the entire composition range for the binary mixtures of benzylalcohol with 1-heptanol, 1-octanol, 1-nonanol and 1-decanol at 298.15 K to 313.15 K and at atmospheric pressure by using Rudolph Research Analytical Digital Density Meter (DDM-2911 model). Further, the speed of sound (u) for the above said mixtures were also measured at 303.15 K and 313.15 K. The experimental density data were used to compute excess molar volumes (V{sup E}) and compared with predictive expression proposed by Redlich–Kister equation. Excess speed of sound (u{sup E}), isentropic compressibility (κ{sub S}) and excess isentropic compressibilities (κ{sub S}{sup E}) were evaluated from experimental sound velocity and density data. Moreover, the experimental speed of sound data was compared in terms of theoretical models proposed by Schaaff's collision factor theory (CFT) and Jacobson's free length theory (FLT). The experimental results were discussed in terms of intermolecular interactions between component molecules.

  19. Ultrasonic Investigations of Molecular Interaction in Binary Mixtures of Cyclohexanone with Isomers of Butanol

    Directory of Open Access Journals (Sweden)

    Sk. Md Nayeem

    2014-01-01

    Full Text Available Ultrasonic speed, u, and density, ρ, have been measured in binary liquid mixtures of cyclohexanone with the isomers of butanol (n-butanol, sec-butanol, and tert-butanol at 308.15 K over the entire range of composition. Molar volume (Vm, adiabatic compressibility (ks, intermolecular free length (Lf, acoustic impedance (z, and their excess/deviation along with Δu have been calculated from the experimental data. These values have been fitted to Redlich-Kister type polynomial equation. Positive values of VmE, Δks, LfE and negative values of zE, Δu have been observed for all the liquid mixtures indicating the existence of weak interactions between components. Rupture of H-bond or reduction in H-bond strength of isomers of butanol or breaking of the structure of one or both of the components in a solution causes the existence of dispersions in the present investigated binary mixtures. The data obtained from V-m,1, V-m,2, and excess partial molar volumes V-m, 1E, V-m, 2E, reflects the inferences drawn from VmE. Furthermore, FTIR spectra support the conclusions drawn from excess/deviation properties. The measured values of ultrasonic speed for all the investigated mixtures have been compared with the theoretically estimated values using empirical relations such as, Nomoto, Van Dael and Vangeels, Impedance and Rao specific sound speed.

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

    Science.gov (United States)

    Dew, William A; Veldhoen, Nik; Carew, Amanda C; Helbing, Caren C; Pyle, Greg G

    2016-03-01

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

  1. Excess Transport Properties of Binary Mixtures of Quinoline with Xylenes at Different Temperatures

    Directory of Open Access Journals (Sweden)

    Sk. Fakruddin

    2012-01-01

    Full Text Available The ultrasonic velocity and density of binary liquid mixtures of quinoline with o-xylene, m-xylene, and p-xylene have been measured over the entire range of composition at = 303.15, 308.15, 313.15, and 318.15 K. Using these data, various parameters like adiabatic compressibility (β, intermolecular free length (, and acoustic impedance ( and some excess parameters like excess adiabatic compressibility (, excess intermolecular free length (, excess acoustic impedance (, and excess ultrasonic velocity ( have been calculated for all the three mixtures. The calculated deviations and excess functions have been fitted to Redlich-Kister polynomial equation. The observed deviations have been explained on the basis of the intermolecular interactions present in these mixtures.

  2. Viscosity and phase separations of binary CO-He and CO-Ar mixtures

    Science.gov (United States)

    Rademacher, N.; Bayarjargal, L.; Morgenroth, W.; Ciezak-Jenkins, J. A.; Winkler, B.

    2015-01-01

    Binary mixtures of 10 and 25 vol% CO in He and 10 vol% CO in Ar have been studied at high pressures and ambient temperature in diamond anvil cells. Phase separations were observed at 5.7(3) GPa, 3.6(2) GPa and 1.6(1) GPa. Earlier studies of ?-He mixtures of comparable concentrations revealed phase separations at significantly larger pressures, while ?-Ar mixtures separate at pressures comparable to those observed in the CO-Ar system here. The viscosity of a CO-rich fluid phase was determined by measuring the velocities of rising He bubbles. After corrections for the influence of the finite container size and of remaining helium in CO, the viscosity of the CO-rich fluid at 3.8(1) GPa was ≈3(1) mPa s, similar to what would be expected for isoelectronic liquid ? under the same conditions.

  3. Measurement of thermodiffusion coefficient in n-alkane binary mixtures: composition dependence.

    Science.gov (United States)

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

    2010-05-27

    In this work, we have measured the thermodiffusion coefficient of different n-alkane binary mixtures at several concentrations using the thermogravitational technique. In particular, we have studied the n-dodecane/n-heptane system as a function of composition and other systems covering a large range of mass differences and concentration at 25 degrees C and 1 atm. The results show that for any concentration the thermodiffusion coefficient of n-alkane mixtures is proportional to the mass difference between the components and to the ratio of the thermal expansion coefficient and viscosity of the mixture. The obtained equation allows us to determine the infinite dilution values of the thermodiffusion coefficient. We compare these values with recent experimental results in dilute polymer solutions and analyze the Brenner theory of thermodiffusion. Finally, it is shown that the thermodiffusion coefficient depends linearly with the mass fraction, and it can be calculated from the viscosity and thermal expansion of the pure components. PMID:20429569

  4. Structural transition in alcohol-water binary mixtures: A spectroscopic study

    Indian Academy of Sciences (India)

    Tuhin Pradhan; Piue Ghoshal; Ranjit Biswas

    2008-03-01

    The strengthening of the hydrogen bonding (H-bond) network as well as transition from the tetrahedral-like water network to the zigzag chain structure of alcohol upon increasing the alcohol concentration in ethanol-water and tertiary butanol (TBA) - water mixtures have been studied by using both steady state and time resolved spectroscopy. Absorption and emission characteristics of coumarin 153 (C153), a widely used non-reactive solvation probe, have been monitored to investigate the structural transition in these binary mixtures. The effects of the hydrogen bond (H-bond) network with alcohol concentration are revealed by a minimum in the peak frequency of the absorption spectrum of C153 which occur at alcohol mole fraction ∼ 0.10 for water-ethanol and at ∼ 0.04 for water-TBA mixtures. These are the mole fractions around which several thermodynamic properties of these mixtures show anomalous change due to the enhancement of H-bonding network. While the strengthening of H-bond network is revealed by the absorption spectra, the emission characteristics show the typical non-ideal alcohol mole fraction dependence at all concentrations. The time resolved anisotropy decay of C153 has been found to be bi-exponential at all alcohol mole fractions. The sharp change in slopes of average rotational correlation time with alcohol mole fraction indicates the structural transition in the environment around the rotating solute. The changes in slopes occur at mole fraction ∼ 0.10 for TBA-water and at ∼ 0.2 for ethanol-water mixtures, which are believed to reflect alcohol mole fraction induced structural changes in these alcohol-water binary mixtures.

  5. Excess isentropic compressibility and speed of sound of the ternary mixture 2-propanol + diethyl ether + n-hexane and the constituent binary mixtures at 298.15 K

    Indian Academy of Sciences (India)

    Gokhan Sovaroglu; Ertunc Aral

    2006-02-01

    Speed of sound and densities of the ternary mixture 2-propanol + diethyl ether + n-hexane and also the binary mixtures 2-propanol + diethyl ether and 2-propanol + n-hexane have been measured at the entire composition range at 298.15 K. The excess isentropic compressibilities and the excess speed of the sound have been calculated from experimental densities and speed of sound. These excess properties of the binary mixtures were fitted to Redlich-Kister equation, while the Cibulka's equation was used to fit the values related to the values to the ternary system. These excess properties have been used to discuss the presence of significant interactions between the component molecules in the binary mixtures and also the ternary mixtures. Speed of sound of the binary mixtures and the ternary mixture have been compared with calculated values from free length theory (FLT), collision factor theory (CFT), Nomoto's relation (NR), Van Deal's ideal mixing relation (IMR) and Junjie's relation (JR). The results are used to compare the relative merits of these theories and relations in terms of the root mean square deviation relative (RMSDr).

  6. Investigation on the performance of the supercritical Brayton cycle with CO2-based binary mixture as working fluid for an energy transportation system of a nuclear reactor

    International Nuclear Information System (INIS)

    In this study, the performance of a SBC (supercritical gas Brayton cycle) using CO2-based binary mixtures as the working fluids have been studied. Based on the thermodynamic analyses, an in-house code has been developed to determine the cycle efficiency and the amounts of heat transfer in the HTR (high temperature recuperator) and the LTR (low temperature recuperator) with different CO2/additive gas ratios. Several gases are selected as potential additives, including O2, He, Ar, Kr, butane and cyclohexane. Compared with the Brayton cycle with pure S–CO2 (supercritical carbon dioxide) as the working fluid, it is found that both CO2–He and CO2–Kr mixtures can improve the thermodynamic performances of the SBC by increasing the cycle efficiency and decreasing the amounts of heat transfer in the HTR and LTR. For the cycles with the pure S–CO2 mixture, CO2–butane mixture and CO2–cyclohexane mixture as the working fluids, the cycle efficiencies decrease with increasing main compressor inlet temperature. However, when the main compressor inlet temperature is above the critical temperature of pure CO2, the cycle efficiencies of the cycles with CO2–butane mixture and CO2–cyclohexane mixture are higher than that of the cycle with pure CO2 as the working fluid. For the cycles with CO2-based binary mixtures and pure S–CO2 as the working fluids, the higher reactor outlet temperature always results into higher cycle efficiencies and larger amount of heat transfer in the HTR and smaller amount of heat transfer in the LTR. - Highlights: • The Brayton cycle performance with different mixtures as working fluids is studied. • Thermodynamic analysis is carried out to evaluate cycle efficiency and heat transfer in HTR and LTR. • The optimum working parameters of the Brayton cycle is proposed to improve working performance

  7. 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.

  8. Nucleate Pool Boiling of Pure Liquids and Binary Mixtures:part II—Analytical Model for Boiling Heat Transfer of Binary Mixtures on Smooth Tubes and Comparison of Analytical Models for both Pure Liqu

    Institute of Scientific and Technical Information of China (English)

    GuoqingWang; YingkeTan

    1996-01-01

    A combined physical model of bubbel growth is propsed along with a corresponding bubble growth model for binary mixtures on smooth tubes.Using the general model of Wang et al.[1].and the bubble growth model for binary mixtures,an analytical model for nucleate pool boiling heat transfer of binary mixtures on smooth tubes is developed.In addition,nucleate pool boiling heat transfer of pure liquids and binary mixtrues on a horizontal smooth tube was studied experimentally.The pure liquids and binary mixtures included water methanol,ehanol,and their binary mixtures.The analytical models for both pure liquids and binary mixtures are in good agreement with the experimental data.

  9. Thermal Conductivity of Gas Mixtures in Chemical Equilibrium

    Science.gov (United States)

    Brokaw, Richard S.

    1960-01-01

    The expression for the thermal conductivity of gas mixtures in chemical equilibrium is presented in a simpler and less restrictive form. This new form is shown to be equivalent to the previous equations.

  10. Degenerate atom-molecule mixture in a cold Fermi gas

    International Nuclear Information System (INIS)

    We show that the atom-molecule mixture formed in a degenerate atomic Fermi gas with interspecies repulsion near a Feshbach resonance constitutes a peculiar system where the atomic component is almost nondegenerate but quantum degeneracy of molecules is important. We develop a thermodynamic approach for studying this mixture, explain experimental observations, and predict optimal conditions for achieving molecular Bose-Einstein condensation

  11. Degenerate Atom-Molecule Mixture in a Cold Fermi Gas

    OpenAIRE

    Kokkelmans, S.J.J.M.F.; Shlyapnikov, G. V.; Salomon, R.

    2004-01-01

    We show that the atom-molecule mixture formed in a degenerate atomic Fermi gas with interspecies repulsion near a Feshbach resonance, constitutes a peculiar system where the atomic component is almost non-degenerate but quantum degeneracy of molecules is important. We develop a thermodynamic approach for studying this mixture, explain experimental observations and predict optimal conditions for achieving molecular BEC.

  12. Volumetric Behavior of Binary Mixtures of Alkoxyethanols and Some Selected Amines at 298.15 K

    Directory of Open Access Journals (Sweden)

    Ayasen Jermaine Kemeakegha

    2015-01-01

    Full Text Available Densities of binary mixtures of 2-methoxyethanol (2-MeO-EtOH and 2-ethoxyethanol (2-EtO-EtOH with hexylamine (HLA, diethylamine (DEA, triethylamine (TEA, tert-butylamine (TBA, aniline (ANL, and benzylamine (BLA have been determined at varying compositions of the alkoxyalkanols at 298.15 K. The excess molar volumes, VE, of the binary mixtures were calculated from the experimental density data of the mixtures and the component single solvents. The calculated excess molar volumes were fitted into the Redlich-Kister polynomial to obtain the fitting coefficients and standard deviations. The excess molar volumes of the binary mixtures of all the solvent systems investigated were negative over the entire range of the solvents composition. The negative values were attributed to stronger hydrogen bond formations between the unlike molecules of mixtures than those between the like molecules of the pure components. The magnitude of the excess molar volumes of the binary mixtures of 2-methoxyethanol and the aliphatic amines were in the order TBA > TEA > DEA > HEA. For the two aromatic amines, the magnitudes were in the order BLA > ANL. For binary mixtures of the amines and 2-ethoxyethanol, the magnitudes were in the order DEA > TEA > TBA > HEA at compositions where the mole fraction of 2-EtO-EtOH was ≤0.5 and TBA > TEA > DEA > HEA above 0.5 mole fraction of 2-EtO-EtOH.

  13. 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.

  14. Investigation of new gas mixtures for the Pestov Counter

    CERN Document Server

    Sann, H; CERN. Geneva; Eschke, J; Lühning, J; Lynen, U; Neyer, C; Pestov, Yu N; Schmidt, H R; Schreiber, B M; Schulze, R; Stelzer, H; Woerner, A; Frankenfeld, U

    2000-01-01

    The physical principle of discharge localization in Pestor spark counters is described. It was experimentally shown that Isoprene is one of the promising candidates to replace 1,3-Butadiene in the standard gas mixture. In the spark counter with the DME-Argon gas mixture and an aluminium nitrite cathode a discharge localization was obtained for the first time. This result is considered as the beginning of a new spark counter technology without conditioning.

  15. Gas gain study for CO sub 2 /isobutane mixtures

    CERN Document Server

    Okuno, H; Nakamura, Y; Fujii, K; Hoshina, K; Kato, Y; Kurihara, Y; Kuroiwa, H; Nitoh, O

    2000-01-01

    We have studied gas amplification properties of a proportional tube filled with CO sub 2 /isobutane gas mixtures. The gas gain was measured for X- and beta-rays as a function of the anode-wire surface field and was used to estimate gain variation along 4.6 m-long stereo anode wires of our proposed central drift chamber for JLC. During the gas gain study, we observed a strong saturation effect for point ionizations.

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

    Science.gov (United States)

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

    2015-02-01

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

  17. Thermal diffusion segregation in granular binary mixtures described by the Enskog equation

    Energy Technology Data Exchange (ETDEWEB)

    Garzo, Vicente, E-mail: vicenteg@unex.es [Departamento de Fisica, Universidad de Extremadura, E-06071 Badajoz (Spain)

    2011-05-15

    The diffusion induced by a thermal gradient in a granular binary mixture is analyzed here in the context of the (inelastic) Enskog equation. Although the Enskog equation neglects velocity correlations among particles that are about to collide, it retains the spatial correlations arising from volume exclusion effects and thus is expected to be applicable for moderate densities. In the steady state with gradients only along a given direction, a segregation criterion is obtained from the thermal diffusion factor {Lambda} by measuring the amount of segregation parallel to the thermal gradient. As expected, the sign of the factor {Lambda} provides a criterion for the transition between the Brazil-nut effect (BNE) and the reverse Brazil-nut effect (RBNE) by varying the parameters of the mixture (the masses and sizes of particles, concentration, solid volume fraction and coefficients of restitution). The form of the phase diagrams for the BNE/RBNE transition is illustrated in detail for several systems, with special emphasis on the significant role played by the inelasticity of collisions. In particular, an effect already found in dilute gases (segregation in a binary mixture of identical masses and sizes but different coefficients of restitution) is extended to dense systems. A comparison with recent computer simulation results reveals good qualitative agreement at the level of the thermal diffusion factor. The present analysis generalizes to arbitrary concentration previous theoretical results derived in the tracer limit case.

  18. 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

    2012-03-01

    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. PMID:22263833

  19. Novel spectrophotometric methods for simultaneous determination of timolol and dorzolamide in their binary mixture.

    Science.gov (United States)

    Lotfy, Hayam Mahmoud; Hegazy, Maha A; Rezk, Mamdouh R; Omran, Yasmin Rostom

    2014-05-21

    Two smart and novel spectrophotometric methods namely; absorbance subtraction (AS) and amplitude modulation (AM) were developed and validated for the determination of a binary mixture of timolol maleate (TIM) and dorzolamide hydrochloride (DOR) in presence of benzalkonium chloride without prior separation, using unified regression equation. Additionally, simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra were developed and validated for simultaneous determination of the binary mixture namely; simultaneous ratio subtraction (SRS), ratio difference (RD), ratio subtraction (RS) coupled with extended ratio subtraction (EXRS), constant multiplication method (CM) and mean centering of ratio spectra (MCR). The proposed spectrophotometric procedures do not require any separation steps. Accuracy, precision and linearity ranges of the proposed methods were determined and the specificity was assessed by analyzing synthetic mixtures of both drugs. They were applied to their pharmaceutical formulation and the results obtained were statistically compared to that of a reported spectrophotometric method. The statistical comparison showed that there is no significant difference between the proposed methods and the reported one regarding both accuracy and precision. PMID:24607469

  20. Quantitative measurements of binary amino acids mixtures in yellow foxtail millet by terahertz time domain spectroscopy.

    Science.gov (United States)

    Lu, Shaohua; Zhang, Xin; Zhang, Zhuoyong; Yang, Yuping; Xiang, Yuhong

    2016-11-15

    Terahertz time domain spectroscopy (THz-TDS) combined with chemometrics has been utilized for the qualitative and quantitative analysis of binary mixtures of l-glutamic acid and l-glutamine which have similar chemical structures and properties. The binary mixtures of amino acids were prepared with yellow foxtail millet matrix, substituted for polyethylene (PE) as previously reported. After proper pretreatment of absorption spectra, quantitative analysis was achieved by partial least squares (PLS) and interval partial least squares (iPLS) regressions. The performance of models was evaluated based on the root mean square error of prediction (RMSEP) and correlation coefficient (R(2)) of cross-validations with bootstrapped Latin partitions as criterion. The iPLS yielded better results with low RMSEP (0.39±0.02%, 0.39±0.02%), and higher R(2) values (0.9904, 0.9906) for glutamine and glutamic acid comparing to the conventional PLS models. Multivariate curve resolution alternating least squares (MCR-ALS) was successfully applied for resolution of pure THz spectra and concentration profiles of two amino acids components from mixtures. PMID:27283659

  1. Toxicity of binary mixtures of oil fractions to sea urchin embryos.

    Science.gov (United States)

    Rial, Diego; Vázquez, José A; Menduiña, Araceli; García, Ana M; González, M Pilar; Mirón, Jesús; Murado, Miguel A

    2013-12-15

    The assumption of additive toxicity for oil compounds is related to a narcotic mode of action. However, the joint toxicity of oil fractions has not been fully investigated. A fractionation of Maya crude oil into aliphatics, aromatics and polars was performed, fractions were dissolved in dimethyl sulfoxide (DMSO) and subsequently toxicity of single fractions and binary mixtures was assessed using the sea urchin embryo test. The descriptive ability of Concentration Addition (CA), Independent Action (IA) and modifications of both models for describing the joint toxicity of mixtures has also been evaluated. The hydrocarbon content extractable with dichloromethane of the fractions dissolved in DMSO was: 12.0 ± 1.8 mg mL(-1), 39.0 ± 0.5 mg mL(-1) and 20.5 ± 2.5 mg mL(-1) for aliphatics, aromatics and polars, respectively. The toxicity of the extracts in DMSO of the fractions as EC50 (μLL(-1)) was: aliphatics (165.8-242.3)binary mixtures (aliphatics-aromatics, aromatics-polars) greater than the IA (aliphatics-polars) according to the Akaike Information Criterion, so CA was considered a better option than IA to explain the joint toxicity of oil fractions. In addition, synergistic or antagonistic effects were not observed. PMID:24231335

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-15

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

  3. 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. PMID:26920521

  4. Uphill diffusion and overshooting in the adsorption of binary mixtures in nanoporous solids

    Science.gov (United States)

    Lauerer, Alexander; Binder, Tomas; Chmelik, Christian; Miersemann, Erich; Haase, Jürgen; Ruthven, Douglas M.; Kärger, Jörg

    2015-07-01

    Under certain conditions, during binary mixture adsorption in nanoporous hosts, the concentration of one component may temporarily exceed its equilibrium value. This implies that, in contrast to Fick's Law, molecules must diffuse in the direction of increasing rather than decreasing concentration. Although this phenomenon of `overshooting' has been observed previously, it is only recently, using microimaging techniques, that diffusive fluxes in the interior of nanoporous materials have become accessible to direct observation. Here we report the application of interference microscopy to monitor `uphill' fluxes, covering the entire period of overshooting from initiation until final equilibration. It is shown that the evolution of the profiles can be adequately predicted from the single-component diffusivities together with the binary adsorption equilibrium data. The guest molecules studied (carbon dioxide, ethane and propene) and the host material (ZSM-58 or DDR) are of practical interest in relation to the development of kinetically selective adsorption separation processes.

  5. Toxicity of binary mixtures of metal oxide nanoparticles to Nitrosomonas europaea.

    Science.gov (United States)

    Yu, Ran; Wu, Junkang; Liu, Meiting; Zhu, Guangcan; Chen, Lianghui; Chang, Yan; Lu, Huijie

    2016-06-01

    Although the widely used metal oxide nanoparticles (NPs) titanium dioxide NPs (n-TiO2), cerium dioxide NPs (n-CeO2), and zinc oxide NPs (n-ZnO) have been well known for their potential cytotoxicities to environmental organisms, their combined effects have seldom been investigated. In this study, the short-term binary effect of n-CeO2 and n-TiO2 or n-ZnO on a model ammonia oxidizing bacterium, Nitrosomonas europaea were evaluated based on the examinations of cells' physiological, metabolic, and transcriptional responses. The addition of n-TiO2 mitigated the negative effect of more toxic n-CeO2 and the binary toxicity (antagonistic toxicity) of n-TiO2 and n-CeO2 was generally lower than the single NPs induced one. While the n-CeO2/n-ZnO mixture exerted higher cytotoxicity (synergistic cytotoxicity) than that from single NPs. The increased addition of the less toxic n-CeO2 exaggerated the binary toxicity of n-CeO2/n-ZnO mixture although the solubility of n-ZnO was not significantly affected, which excluded the contribution of the dissolved Zn ions to the enhancement of the combined cytotoxicity. The cell membrane disturbances and NP internalizations were detected for all the NP impacted cultures and the electrostatic interactions among the two distinct NPs and the cells were expected to play a key role in mediating their direct contacts and the eventual binary nanotoxicity to the cells. PMID:27016814

  6. Homogeneous bubble nucleation in binary systems of liquid solvent and dissolved gas

    Science.gov (United States)

    Němec, Tomáš

    2016-03-01

    A formulation of the classical nucleation theory (CNT) is developed for bubble nucleation in a binary system composed of a liquid solvent and a dissolved gas. The theoretical predictions are compared to the experimental nucleation data of four binary mixtures, i.e. diethylether - nitrogen, propane - carbon dioxide, isobutane - carbon dioxide, and R22 (chlorodifluoromethane) - carbon dioxide. The presented CNT formulation is found to improve the precision of the simpler theoretical method of Ward et al. [J. Basic Eng. 92 (10), 71-80, 1970] based on the weak-solution approximation. By analyzing the available experimental nucleation data, an inconsistency in the data reported by Mori et al. [Int. J. Heat Mass Transfer, 19 (10), 1153-1159, 1976] for propane - carbon dioxide and R22 - carbon dioxide is identified.

  7. Binary PAH mixtures cause additive or antagonistic effects on gene expression but synergistic effects on DNA adduct formation

    NARCIS (Netherlands)

    Staal, Y.C.M.; Hebels, D.G.A.J.; Herwijnen, M.H.M. van; Gottschalk, R.W.H.; Schooten, F.J. van; Delft, J.H.M. van

    2007-01-01

    Polycyclic aromatic hydrocarbons (PAHs) cover a wide range of structurally related compounds which differ greatly in their carcinogenic potency. PAH exposure usually occurs through mixtures rather than individual compounds. Therefore, we assessed whether the effects of binary PAH mixtures on gene ex

  8. Method for removing methane from gas mixtures

    NARCIS (Netherlands)

    Makkee, M.; Xu Xiao, D.

    2008-01-01

    The invention relates to a method for oxidizing methane, comprising passing a gaseous, methane containing mixture over a catalyst, comprising a carrier with a substrate surface which consists substantially of titanium dioxide with a combination of platinum and palladium thereon, in the presence of m

  9. Picosecond solvation dynamics--a potential viewer of DMSO-water binary mixtures.

    Science.gov (United States)

    Banik, Debasis; Kundu, Niloy; Kuchlyan, Jagannath; Roy, Arpita; Banerjee, Chiranjib; Ghosh, Surajit; Sarkar, Nilmoni

    2015-02-01

    In this work, we have investigated the composition dependent anomalous behavior of dimethyl sulfoxide (DMSO)-water binary mixture by collecting the ultrafast solvent relaxation response around a well known solvation probe Coumarin 480 (C480) by using a femtosecond fluorescence up-conversion spectrometer. Recent molecular dynamics simulations have predicted two anomalous regions of DMSO-water binary mixture. Particularly, these studies encourage us to investigate the anomalies from experimental background. DMSO-water binary mixture has repeatedly given evidences of its dual anomalous nature in front of our systematic investigation through steady-state and time-resolved measurements. We have calculated average solvation times of C480 by two individual well-known methods, among them first one is spectral-reconstruction method and another one is single-wavelength measurement method. The results of both the methods roughly indicate that solvation time of C480 reaches maxima in the mole fraction of DMSO XD = 0.12-0.17 and XD = 0.27-0.35, respectively. Among them, the second region (XD = 0.27-0.35) is very common as most of the thermodynamic properties exhibit deviation in this range. Most probably, the anomalous solvation trend in this region is fully guided by the shear viscosity of the medium. However, the first region is the most interesting one. In this region due to formation of strongly hydrogen bonded 1DMSO:2H2O complexes, hydration around the probe C480 decreases, as a result of which solvation time increases. PMID:25662652

  10. Picosecond solvation dynamics—A potential viewer of DMSO—Water binary mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Banik, Debasis; Kundu, Niloy; Kuchlyan, Jagannath; Roy, Arpita; Banerjee, Chiranjib; Ghosh, Surajit; Sarkar, Nilmoni, E-mail: nilmoni@chem.iitkgp.ernet.in [Department of Chemistry, Indian Institute of Technology, Kharagpur, WB 721302 (India)

    2015-02-07

    In this work, we have investigated the composition dependent anomalous behavior of dimethyl sulfoxide (DMSO)-water binary mixture by collecting the ultrafast solvent relaxation response around a well known solvation probe Coumarin 480 (C480) by using a femtosecond fluorescence up-conversion spectrometer. Recent molecular dynamics simulations have predicted two anomalous regions of DMSO-water binary mixture. Particularly, these studies encourage us to investigate the anomalies from experimental background. DMSO-water binary mixture has repeatedly given evidences of its dual anomalous nature in front of our systematic investigation through steady-state and time-resolved measurements. We have calculated average solvation times of C480 by two individual well-known methods, among them first one is spectral-reconstruction method and another one is single-wavelength measurement method. The results of both the methods roughly indicate that solvation time of C480 reaches maxima in the mole fraction of DMSO X{sub D} = 0.12–0.17 and X{sub D} = 0.27–0.35, respectively. Among them, the second region (X{sub D} = 0.27–0.35) is very common as most of the thermodynamic properties exhibit deviation in this range. Most probably, the anomalous solvation trend in this region is fully guided by the shear viscosity of the medium. However, the first region is the most interesting one. In this region due to formation of strongly hydrogen bonded 1DMSO:2H{sub 2}O complexes, hydration around the probe C480 decreases, as a result of which solvation time increases.

  11. Simulation of gas mixture drift properties for GasPixel detector for modernization of ATLAS

    International Nuclear Information System (INIS)

    Results of simulation of gas mixture drift properties for GasPixel detector are presented. The properties of gaseous mixtures for the GasPixel detector have been studied in view of its use in high luminosity tracking applications for the ATLAS Inner Detector in a future super-LHC collider

  12. 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.

  13. Thermo Physical Properties for Binary Mixture of Dimethylsulfoxide and Isopropylbenzene at Various Temperatures

    Directory of Open Access Journals (Sweden)

    Maninder Kumar

    2013-01-01

    Full Text Available Density, refractive index, speed of sound, and viscosity have been measured of binary mixture dimethylsulfoxide (DMSO + isopropylbenzene (CUMENE over the whole composition range at 298.15, 303.15, 308.15, and 313.15 K and atmospheric pressure. From these experimental measurements the excess molar volume, deviations in viscosity, molar refractivity, speed of sound, and isentropic compressibility have been calculated. These deviations have been correlated by a polynomial Redlich-Kister equation to derive the coefficients and standard error. The viscosities have furthermore been correlated with two or three parameter models, that is, herric correlation and McAllister model, respectively.

  14. Axial segregation of horizontally vibrated binary granular mixtures in an offset-Christmas tree channel

    Science.gov (United States)

    Bhateja, Ashish; Sharma, Ishan; Singh, Jayant K.

    2013-06-01

    We investigate segregation in a horizontally vibrated binary granular mixture in a closed offset-Christmas tree channel. The segregation phenomenon occurs in two steps: vertical sorting followed by axial segregation. In the first step, sorting occurs via Brazil-nut effect or reverse Brazil-nut effect depending on the particles' size and density ratios. The two layers thus formed then separate axially towards opposite-ends of the channel with the top layer always moving towards root of the Christmas tree. We discuss the segregation mechanism responsible for axial segregation.

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

    International Nuclear Information System (INIS)

    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

  16. 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.

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

    OpenAIRE

    Bhupesh G Nemmaniwar; Kalyankar, Namdeo V.; Pothaji L. Kadam

    2013-01-01

    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),...

  18. Dielectric Behavior of Binary Mixture of 2, 3-Dichloroaniline with 2-Methoxyethanol at 200 C

    OpenAIRE

    Bhupesh G Nemmaniwar; Vijaykumar Panchal; Potaji Kadam

    2014-01-01

    Densities, viscosities, refractive indices, dielectric constant (ɛ`) and dielectric loss (ɛ``) of 2,3-Dichloroaniline (2,3-DCA) and 2-methoxyethanol (2-ME) for different mole fractions of 2,3-Dichloroaniline in binary mixture have been measured at single microwave frequency 10.985 GHz at 200C by Surber method at microwave X-band. The values of dielectric parameters (ɛ`and ɛ``) have been used to evaluate the molar polarization (P12) and loss tangent (tan δ) excess permittivity (Δɛ``), exces...

  19. Drag Coefficient of a Rigid Spherical Particle in a Near-Critical Binary Fluid Mixture

    Science.gov (United States)

    Okamoto, Ryuichi; Fujitani, Youhei; Komura, Shigeyuki

    2013-08-01

    We calculate the drag coefficient of a rigid spherical particle in an incompressible binary fluid mixture. A weak preferential attraction is assumed between the particle surface and one of the fluid components, and the difference in the viscosity between the two components is neglected. Using the Gaussian free-energy functional and solving the hydrodynamic equation explicitly, we can show that the preferential attraction makes the drag coefficient larger as the bulk correlation length becomes longer. The dependence of the deviation from the Stokes law on the correlation length, when it is short, turns out to be much steeper than the previous estimates.

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

    International Nuclear Information System (INIS)

    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 25OC 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)

  1. Polymer-Enforced Crystallization of a Eutectic Binary Hard Sphere Mixture

    OpenAIRE

    Kozina, Anna; Díaz-Leyva, Pedro; Bartsch, Eckhard; Palberg, Thomas

    2010-01-01

    We prepared a buoyancy matched binary mixture of polydisperse polystyrene microgel spheres of size ratio 0.785 and at a volume fraction of 0.567 just below the kinetic glass transition. In line with theoretical expectations, a eutectic phase behavior was observed, but only a minor fraction of the samples crystallized at all. By adding a short non-adsorbing polymer we enforce inter-species fractionation into coexisting pure component crystals, which in turn also shows signs of intra-species fr...

  2. Different spectrophotometric methods applied for the analysis of binary mixture of flucloxacillin and amoxicillin: A comparative study

    Science.gov (United States)

    Attia, Khalid A. M.; Nassar, Mohammed W. I.; El-Zeiny, Mohamed B.; Serag, Ahmed

    2016-05-01

    Three different spectrophotometric methods were applied for the quantitative analysis of flucloxacillin and amoxicillin in their binary mixture, namely, ratio subtraction, absorbance subtraction and amplitude modulation. A comparative study was done listing the advantages and the disadvantages of each method. All the methods were validated according to the ICH guidelines and the obtained accuracy, precision and repeatability were found to be within the acceptable limits. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can be used for the routine analysis of flucloxacillin and amoxicillin in their binary mixtures.

  3. Modelling Circumbinary Gas Flows in Close T Tauri Binaries

    CERN Document Server

    de Val-Borro, M; Stempels, H C; Pepliński, A

    2011-01-01

    Young close binaries open central gaps in the surrounding circumbinary accretion disc, but the stellar components may still gain mass from gas crossing through the gap. It is not well understood how this process operates and how the stellar components are affected by such inflows. Our main goal is to investigate how gas accretion takes place and evolves in close T Tauri binary systems. In particular, we model the accretion flows around two close T Tauri binaries, V4046 Sgr and DQ Tau, both showing periodic changes in emission lines, although their orbital characteristics are very different. In order to derive the density and velocity maps of the circumbinary material, we employ two-dimensional hydrodynamic simulations with a locally isothermal equation of state. The flow patterns become quasi-stable after a few orbits in the frame co-rotating with the system. Gas flows across the circumbinary gap through the co-rotating Lagrangian points, and local circumstellar discs develop around both components. Spiral de...

  4. High pressure and temperature optical flow cell for Near-Infra-Red spectroscopic analysis of gas mixtures

    Science.gov (United States)

    Norton, C. G.; Suedmeyer, J.; Oderkerk, B.; Fieback, T. M.

    2014-05-01

    A new optical flow cell with a new optical arrangement adapted for high pressures and temperatures using glass fibres to connect light source, cell, and spectrometer has been developed, as part of a larger project comprising new methods for in situ analysis of bio and hydrogen gas mixtures in high pressure and temperature applications. The analysis is based on measurements of optical, thermo-physical, and electromagnetic properties in gas mixtures with newly developed high pressure property sensors, which are mounted in a new apparatus which can generate gas mixtures with up to six components with an uncertainty of composition of as little as 0.1 mol. %. Measurements of several pure components of natural gases and biogases to a pressure of 20 MPa were performed on two isotherms, and with binary mixtures of the same pure gases at pressures to 17.5 MPa. Thereby a new method of analyzing the obtained spectra based on the partial density of methane was investigated.

  5. Simultaneous spectrophotometric determination of amlodipine besylate and atorvastatin calcium in binary mixture

    Directory of Open Access Journals (Sweden)

    Sahu R

    2007-01-01

    Full Text Available A rapid, simple, accurate and precise UV Spectrophotometric method using simultaneous equation was developed for the simultaneous determination of amlodipine besylate and atorvastatin calcium in a binary mixture. In the proposed method, the signals were measured at 238.2 and 246.6 nm corresponding to the absorbance maxima of amlodipine besylate and atorvastatin calcium in methanol, respectively. Linearity was observed in the concentration range of 5-30 µg/ml for both the drugs. Concentration of each drug was obtained by using the absorptivity values calculated for both the drugs at two wavelengths, 238.2 and 246.6 nm and solving the simultaneous equations. The method was validated statistically and recovery study was performed to confirm the accuracy of the method. Laboratory prepared synthetic mixture was successfully analyzed using the developed method.

  6. Characterization of Dimethylsulfoxide / Glycerol Mixtures: A Binary Solvent System for the Study of "Friction-Dependent" Chemical Reactivity

    OpenAIRE

    Angulo Nunez, Gonzalo Manuel; Brucka, Marta; Gerecke, Mario; Grampp, Günter; Jeannerat, Damien; Milkiewicz, Jadwiga; Mitrev, Yavor; Radzewicz, Czesław; Rosspeintner, Arnulf; Vauthey, Eric; Wnuk, Paweł

    2016-01-01

    The properties of binary mixtures of dimethylsulfoxide and glycerol, measured by several techniques, are reported. Special attention is given to those properties contributing or affecting chemical reactions. In this respect the investigated mixture behaves as a relatively simple solvent and it is especially well suited for studies on the influence of viscosity in chemical reactivity. This is due to the relative invariance of the dielectric properties of the mixture. However, special caution m...

  7. Extra-terrestrial sprites: laboratory investigations in planetary gas mixtures

    NARCIS (Netherlands)

    Dubrovin, D.; Yair, Y.; Price, C.; Nijdam, S.; Clevis, T.T.J.; Veldhuizen, E.M. van; Ebert, U.

    2012-01-01

    We investigate streamers in gas mixtures representing the atmospheres of Jupiter, Saturn (H2-He) and Venus (CO2-N2). Streamer diameters, velocities, radiance and overall morphology are investigated with fast ICCD camera images. We confirm experimentally the scaling of streamer diameters in these gas

  8. Characterisation of Oil-Gas Mixtures by Raman Spectroscopy

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Berg, Rolf W.; Stenby, Erling Halfdan

    2004-01-01

    . The present project deals with development of a technique for quick analysis of oil-gas mixtures. The main emphasis is laid on characterisation of gas phases in equilibrium with oil at high pressures and high temperatures by Raman spectroscopy. The Raman technique has a great potential of being useful, due...

  9. 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

  10. Fluorescent probe partitioning in GUVs of binary phospholipid mixtures: implications for interpreting phase behavior.

    Science.gov (United States)

    Juhasz, Janos; Davis, James H; Sharom, Frances J

    2012-01-01

    The phase behavior of membrane lipids is known to influence the organization and function of many integral proteins. Giant unilamellar vesicles (GUVs) provide a very useful model system in which to examine the details of lipid phase separation using fluorescence imaging. The visualization of domains in GUVs of binary and ternary lipid mixtures requires fluorescent probes with partitioning preference for one of the phases present. To avoid possible pitfalls when interpreting the phase behavior of these lipid mixtures, sufficiently thorough characterization of the fluorescent probes used in these studies is needed. It is now evident that fluorescent probes display different partitioning preferences between lipid phases, depending on the specific lipid host system. Here, we demonstrate the benefit of using a panel of fluorescent probes and confocal fluorescence microscopy to examine phase separation in GUVs of binary mixtures of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). Patch and fibril gel phase domains were found to co-exist with liquid disordered (l(d)) domains on the surface of GUVs composed of 40:60 mol% DOPC/DPPC, over a wide range of temperatures (14-25°C). The fluorescent lipid, 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(7-nitro-2-1,3-benzoxadiazol-4-yl (NBD-DPPE), proved to be the most effective probe for visualization of fibril domains. In the presence of Lissamine(TM) rhodamine B 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine (Rh-DPPE) we were unable to detect fibril domains. This fluorophore also affected the partitioning behavior of other fluorescent probes. Overall, we show that the selection of different fluorescent probes as lipid phase reporters can result in very different interpretation of the phase behavior of DOPC/DPPC mixtures. PMID:21945563

  11. 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.

  12. Optical studies of a binary liquid crystal mixture exhibiting induced smectic A phase

    Science.gov (United States)

    Thingujam, Kiranmala; Bhattacharjee, Ayon; Choudhury, Basana; Sarkar, S. D.

    2016-08-01

    A binary liquid crystalline mixture of a monotropic polar compound 4-cyanophenyl 4'- n-pentyl benzoate (CPPB) and an enantiotropic non-polar compound 4- n-hexyl phenyl 4- n'-pentyloxy benzoate (ME5O.6) shows the presence of an induced smectic A phase in the region 0.1 ≤ x CPPB ≤ 0.82, where x CPPB is the mole fraction of CPPB. The results of texture study, density study and refractive index measurements of the eutectic mixture along with those of the pure samples are reported in this paper. The density values of the eutectic mixture are found to be much higher than that of the pure samples. The determination of order parameters of the pure samples and eutectic mixture has been carried out. In order to determine the order parameters of the samples, we have used different methods, Vuks', Neugebauer's, modified Vuks' and direct extrapolation method. The results of order parameters obtained from the different approaches are compared and analysed in detail.

  13. Discriminative Stimulus Effects of Binary Drug Mixtures: Studies with Cocaine, MDPV, and Caffeine.

    Science.gov (United States)

    Collins, Gregory T; Abbott, Megan; Galindo, Kayla; Rush, Elise L; Rice, Kenner C; France, Charles P

    2016-10-01

    Illicit drug preparations often include more than one pharmacologically active compound. For example, cocaine and synthetic cathinones [e.g., 3,4-methylenedioxypyrovalerone (MDPV)] are often mixed with caffeine before sale. Caffeine is likely added to these preparations because it is inexpensive and legal; however, caffeine might also mimic or enhance some of the effects of cocaine or MDPV. In these studies, male Sprague-Dawley rats were trained to discriminate 10 mg/kg cocaine from saline, and the discriminative stimulus effects of cocaine, caffeine, and MDPV were evaluated alone and as binary mixtures (cocaine and caffeine, MDPV and caffeine, and cocaine and MDPV) at fixed-dose ratios of 3:1, 1:1, and 1:3 relative to the dose of each drug that produced 50% cocaine-appropriate responding. Dose-addition analyses were used to determine the nature of the drug-drug interactions for each mixture (e.g., additive, supra-additive, or subadditive). Although additive interactions were observed for most mixtures, supra-additive interactions were observed at the 50% effect level for the 1:1 mixture of cocaine and caffeine and at the 80% effect level for all three mixtures of cocaine and caffeine, as well as for the 3:1 and 1:3 mixtures of cocaine and MDPV. These results demonstrate that with respect to cocaine-like discriminative stimulus effects, caffeine can function as a substitute in drug preparations containing either cocaine or MDPV, with enhancements of cocaine-like effects possible under certain conditions. Further research is needed to determine whether similar interactions exist for other abuse-related or toxic effects of drug preparations, including cocaine, synthetic cathinones, and caffeine. PMID:27493274

  14. Discriminative Stimulus Effects of Binary Drug Mixtures: Studies with Cocaine, MDPV, and Caffeine

    Science.gov (United States)

    Abbott, Megan; Galindo, Kayla; Rush, Elise L.; Rice, Kenner C.; France, Charles P.

    2016-01-01

    Illicit drug preparations often include more than one pharmacologically active compound. For example, cocaine and synthetic cathinones [e.g., 3,4-methylenedioxypyrovalerone (MDPV)] are often mixed with caffeine before sale. Caffeine is likely added to these preparations because it is inexpensive and legal; however, caffeine might also mimic or enhance some of the effects of cocaine or MDPV. In these studies, male Sprague-Dawley rats were trained to discriminate 10 mg/kg cocaine from saline, and the discriminative stimulus effects of cocaine, caffeine, and MDPV were evaluated alone and as binary mixtures (cocaine and caffeine, MDPV and caffeine, and cocaine and MDPV) at fixed-dose ratios of 3:1, 1:1, and 1:3 relative to the dose of each drug that produced 50% cocaine-appropriate responding. Dose-addition analyses were used to determine the nature of the drug-drug interactions for each mixture (e.g., additive, supra-additive, or subadditive). Although additive interactions were observed for most mixtures, supra-additive interactions were observed at the 50% effect level for the 1:1 mixture of cocaine and caffeine and at the 80% effect level for all three mixtures of cocaine and caffeine, as well as for the 3:1 and 1:3 mixtures of cocaine and MDPV. These results demonstrate that with respect to cocaine-like discriminative stimulus effects, caffeine can function as a substitute in drug preparations containing either cocaine or MDPV, with enhancements of cocaine-like effects possible under certain conditions. Further research is needed to determine whether similar interactions exist for other abuse-related or toxic effects of drug preparations, including cocaine, synthetic cathinones, and caffeine. PMID:27493274

  15. Mutual diffusion in the ternary mixture of water + methanol + ethanol and its binary subsystems.

    Science.gov (United States)

    Parez, Stanislav; Guevara-Carrion, Gabriela; Hasse, Hans; Vrabec, Jadran

    2013-03-21

    Mutual diffusion is investigated by means of experiment and molecular simulation for liquid mixtures containing water + methanol + ethanol. The Fick diffusion coefficient is measured by Taylor dispersion as a function of composition for all three binary subsystems under ambient conditions. For the aqueous systems, these data compare well with literature values. In the case of methanol + ethanol, experimental measurements of the Fick diffusion coefficient are presented for the first time. The Maxwell-Stefan diffusion coefficient and the thermodynamic factor are predicted for the ternary mixture as well as its binary subsystems by molecular simulation in a consistent manner. The resulting Fick diffusion coefficient is compared to present measurements and that obtained from the classical simulation approach, which requires experimental vapor-liquid equilibrium or excess enthalpy data. Moreover, the self-diffusion coefficients and the shear viscosity are predicted by molecular dynamics and are favorably compared to experimental literature values. The presented ternary diffusion data should facilitate the development of aggregated predictive models for diffusion coefficients of polar and hydrogen-bonding systems. PMID:23400088

  16. Time requirements in closed and open batch distillation arrangements for separation of a binary mixture

    Directory of Open Access Journals (Sweden)

    Zhao Shuo

    2014-12-01

    Full Text Available Batch time requirements are provided for the separation of binary zeotropic mixtures in two different multivessel columns (with and without vapor bypass, a non-cyclic two-vessel column and a regular batch column based on dynamic simulations. The first three columns are operated as closed (total reflux systems and the regular batch column is operated as an open (partial reflux system. We analyze the effects of feed composition, relative volatility and product specification on the time requirements. The multivessel arrangements perform better than the regular batch column, which requires from 4.00 to 34.67% more time to complete a given separation. The elimination of the vapor bypass in the multivessel column is impractical though it has a positive effect on the batch time requirements. Thus, the multivessel column, with the vapor stream bypassing the intermediate vessel, is proposed as the best candidate for a binary zeotropic mixture with low concentration of light component, low relative volatility and high product purity demand. Furthermore, an experimental multivessel column with vapor bypass is built and the corresponding experiments verify the simulations.

  17. 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. 

  18. Expansion of gas mixtures in free jets

    International Nuclear Information System (INIS)

    The cooling of mixtures of SF6 and N2 (He, Ar) in a free jet expansion is studied experimentally; laser scattering is used to detect condensation, and electron beam fluorescence or infrared laser absorption to measure local rotational temperatures in N2 and SF6. Experimental and theoretical results are presented with respect to lowest temperatures that can be reached, the onset of condensation, and the influence of concentration X (SF6), psub(o)D (stagnation pressure Psub(o), orifice diameter D), and D on condensation and relaxation. (author)

  19. 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, JW; ENGBERTS, JBFN; BLANDAMER, MJ

    1993-01-01

    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 fracti

  20. Formation of H2-He substellar bodies in cold conditions. Gravitational stability of binary mixtures in a phase transition

    Science.gov (United States)

    Füglistaler, A.; Pfenniger, D.

    2016-06-01

    Context. Molecular clouds typically consist of 3/4 H2, 1/4 He and traces of heavier elements. In an earlier work we showed that at very low temperatures and high densities, H2 can be in a phase transition leading to the formation of ice clumps as large as comets or even planets. However, He has very different chemical properties and no phase transition is expected before H2 in dense interstellar medium conditions. The gravitational stability of fluid mixtures has been studied before, but these studies did not include a phase transition. Aims: We study the gravitational stability of binary fluid mixtures with special emphasis on when one component is in a phase transition. The numerical results are aimed at applications in molecular cloud conditions, but the theoretical results are more general. Methods: First, we study the gravitational stability of van der Waals fluid mixtures using linearized analysis and examine virial equilibrium conditions using the Lennard-Jones intermolecular potential. Then, combining the Lennard-Jones and gravitational potentials, the non-linear dynamics of fluid mixtures are studied via computer simulations using the molecular dynamics code LAMMPS. Results: Along with the classical, ideal-gas Jeans instability criterion, a fluid mixture is always gravitationally unstable if it is in a phase transition because compression does not increase pressure. However, the condensed phase fraction increases. In unstable situations the species can separate: in some conditions He precipitates faster than H2, while in other conditions the converse occurs. Also, for an initial gas phase collapse the geometry is essential. Contrary to spherical or filamentary collapses, sheet-like collapses starting below 15 K easily reach H2 condensation conditions because then they are fastest and both the increase of heating and opacity are limited. Conclusions: Depending on density, temperature and mass, either rocky H2 planetoids, or gaseous He planetoids form. H2

  1. A facility for the measurement of electron transport parameters in a gas mixture

    CERN Document Server

    Golovatyuk, V M; Grancagnolo, F; Perrino, R; Primavera, M

    2001-01-01

    A facility for studying electron transport parameters in a given gas mixture is illustrated. A controlled ionization is induced by means of multiple-photon processes by focussing a short (~1 ns) pulsed nitrogen laser in the gas gap. The test gas volume, where a suitable E-field is applied, is installed on a micrometric motion system which allows to accurately scan the volume (resolution ~3 mu m) with a beam focus waist of the order of 10 mu m. Such a facility has been used for measurements of the gas parameters of the He drift chamber of KLOE experiment at DA Phi NE and for preliminary measurements of gain and attachment coefficients in the binary mixtures (C/sub 2/H/sub 2/F /sub 4/+3%, 10% iso C/sub 4/H/sub 10/) planned for the ATLAS and CMS RPC systems. An upgraded version of the set-up, which allows also for O/sub 2/ and H/sub 2/O vapour controlled contamination, is currently being used for measurements on ternary mixtures (C/sub 2/H/sub 2/F /sub 4/+iso C/sub 4/H/sub 10/+SF/sub 6/). (5 refs).

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

    Directory of Open Access Journals (Sweden)

    R. C. Thakur

    2015-03-01

    Full Text Available Partial molar volumes of copper sulphate and zinc sulphate have been determined in water and binary aqueous mixtures of propylene glycol (2,4,6 and 8% by weight of propylene glycol at 303.15 K with the help of density measurements. Effect of temperature on the partial molar volumes was also analysed for these salts in water and binary aqueous mixtures of propylene glycol. Results obtained have been analysed by Masson’s equation and the experimental values of slopes and partial molar volumes of these transition metals sulphates have been interpreted in terms of ion-ion or ion –solvent interactions. Limiting molar expansibilities ( have also been determined which is interpreted in terms of structure making or breaking capacities of transition metal sulphates. The transition metal sulphates have been found as structure promoter in water and binary aqueous mixture of propylene glycol.

  3. CH/pi interaction between benzene and hydrocarbons having six carbon atoms in their binary liquid mixtures.

    Science.gov (United States)

    Kasahara, Yasutoshi; Suzuki, Yuji; Kabasawa, Aino; Minami, Hideyuki; Matsuzawa, Hideyo; Iwahashi, Makio

    2010-01-01

    Molecular interactions between benzene and hydrocarbons having six carbon atoms, such as hexane, cyclohexane and 1-hexene in their binary liquid mixtures were studied through the measurements of density, viscosity, self-diffusion coefficient, (13)C NMR spin-lattice relaxation time and (1)H NMR chemical shift. CH/pi attraction between hexane and benzene in their binary mixture was observed in a relatively benzene rich region, whereas a special attractive interaction was not observed between cyclohexane and benzene. On the other hand, 1-hexene and benzene in their binary mixtures were characteristic in their self-diffusion coefficient behaviors: 1-hexene more strongly attract benzene not only by the CH/pi attraction but also probably by the p/p interaction between the double bond in 1-hexene and the p-electron in benzene ring. PMID:20032596

  4. Multiscale Modeling of the Effect of Pressure on the Interfacial Tension and Other Cohesion Parameters in Binary Mixtures.

    Science.gov (United States)

    Mayoral, E; Nahmad-Achar, E

    2016-03-10

    We study and predict the interfacial tension, solubility parameters, and Flory-Huggins parameters of binary mixtures as functions of pressure and temperature, using multiscale numerical simulation. A mesoscopic approach is proposed for simulating the pressure dependence of the interfacial tension for binary mixtures, at different temperatures, using classical dissipative particle dynamics (DPD). The thermodynamic properties of real systems are reproduced via the parametrization of the repulsive interaction parameters as functions of pressure and temperature via molecular dynamics simulations. Using this methodology, we calculate and analyze the cohesive energy density and the solubility parameters of different species obtaining excellent agreement with reported experimental behavior. The pressure- and temperature-dependent Flory-Huggins and repulsive DPD interaction parameters for binary mixtures are also obtained and validated against experimental data. This multiscale methodology offers the benefit of being applicable for any species and under difficult or nonfeasible experimental conditions, at a relatively low computational cost. PMID:26840645

  5. Multiscale Modeling of the effect of Pressure on the Interfacial Tension and other Cohesion Parameters in Binary Mixtures

    CERN Document Server

    Mayoral, E

    2016-01-01

    We study and predict the interfacial tension, solubility parameters and Flory-Huggins parameters of binary mixtures as functions of pressure and temperature, using multiscale numerical simulation. A mesoscopic approach is proposed for simulating the pressure dependence of the interfacial tension for binary mixtures, at different temperatures, using classical Dissipative Particle Dynamics (DPD). The thermodynamic properties of real systems are reproduced via the parametrization of the repulsive interaction parameters as functions of pressure and temperature via Molecular Dynamics simulations. Using this methodology, we calculate and analyze the cohesive density energy and the solubility parameters of different species obtaining excellent agreement with reported experimental behavior. The pressure- and temperature-dependent Flory-Huggins and repulsive DPD interaction parameters for binary mixtures are also obtained and validated against experimental data. This multiscale methodology offers the benefit of being ...

  6. Systematic study of RPC performances in polluted or varying gas mixtures compositions: an online monitor system for the RPC gas mixture at LHC

    CERN Document Server

    Capeans, M; Mandelli, B

    2012-01-01

    The importance of the correct gas mixture for the Resistive Plate Chamber (RPC) detector systems is fundamental for their correct and safe operation. A small change in the percentages of the gas mixture components can alter the RPC performance and this will rebound on the data quality in the ALICE, ATLAS and CMS experiments at CERN. A constant monitoring of the gas mixture injected in the RPCs would avoid such kind of problems. A systematic study has been performed to understand RPC performances with several gas mixture compositions and in the presence of common gas impurities. The systematic analysis of several RPC performance parameters in different gas mixtures allows the rapid identification of any variation in the RPC gas mixture. A set-up for the online monitoring of the RPC gas mixture in the LHC gas systems is also proposed.

  7. Prediction and assessment of ecogenotoxicity of antineoplastic drugs in binary mixtures.

    Science.gov (United States)

    Kundi, Michael; Parrella, Alfredo; Lavorgna, Margherita; Criscuolo, Emma; Russo, Chiara; Isidori, Marina

    2016-08-01

    The combined genotoxic effects of four anticancer drugs (5-fluorouracil [5-FU], cisplatin [CDDP], etoposide [ET], and imatinib mesylate [IM]) were studied testing their binary mixtures in two crustaceans that are part of the freshwater food chain, namely Daphnia magna and Ceriodaphnia dubia. Genotoxicity was assessed using the in vivo comet assay. Assessment was based on two distinct effect sizes determined from dose-response experiments. Doses for single and combined exposures expected to result in these effect sizes were computed based on Bliss independence as reference model. Statistical comparison by analysis of variance of single and combined toxicities allowed accepting or rejecting the independency hypothesis. The results obtained for D. magna showed independent action for all mixtures except for IM+5-FU that showed an antagonistic interaction. In C. dubia, most mixtures had antagonist interactions except IM+5-FU and IM+CDDP that showed Bliss independence. Despite the antagonistic interactions, our results demonstrated that combinations of anticancer drugs could be of environmental concern because effects occur at very low concentrations that are in the range of concentrations encountered in aquatic systems. PMID:26139396

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

    Science.gov (United States)

    Zhao, Yongliang; Feng, Yanhui; Zhang, Xinxin

    2016-09-01

    The adsorption and diffusion of the CO2-CH4 mixture in coal and the underlying mechanisms significantly affect the design and operation of any CO2-enhanced coal-bed methane recovery (CO2-ECBM) project. In this study, bituminous coal was fabricated based on the Wiser molecular model and its ultramicroporous parameters were evaluated; molecular simulations were established through Grand Canonical Monte Carlo (GCMC) and Molecular Dynamic (MD) methods to study the effects of temperature, pressure, and species bulk mole fraction on the adsorption isotherms, adsorption selectivity, three distinct diffusion coefficients, and diffusivity selectivity of the binary mixture in the coal ultramicropores. It turns out that the absolute adsorption amount of each species in the mixture decreases as temperature increases, but increases as its own bulk mole fraction increases. The self-, corrected, and transport diffusion coefficients of pure CO2 and pure CH4 all increase as temperature or/and their own bulk mole fractions increase. Compared to CH4, the adsorption and diffusion of CO2 are preferential in the coal ultramicropores. Adsorption selectivity and diffusivity selectivity were simultaneously employed to reveal that the optimal injection depth for CO2-ECBM is 800-1000 m at 308-323 K temperature and 8.0-10.0 MPa. PMID:27518119

  9. The use of zeta potential as a tool to study phase transitions in binary phosphatidylcholines mixtures.

    Science.gov (United States)

    Sierra, M B; Pedroni, V I; Buffo, F E; Disalvo, E A; Morini, M A

    2016-06-01

    Temperature dependence of the zeta potential (ZP) is proposed as a tool to analyze the thermotropic behavior of unilamellar liposomes prepared from binary mixtures of phosphatidylcholines in the absence or presence of ions in aqueous suspensions. Since the lipid phase transition influences the surface potential of the liposome reflecting a sharp change in the ZP during the transition, it is proposed as a screening method for transition temperatures in complex systems, given its high sensitivity and small amount of sample required, that is, 70% less than that required in the use of conventional calorimeters. The sensitivity is also reflected in the pre-transition detection in the presence of ions. Plots of phase boundaries for these mixed-lipid vesicles were constructed by plotting the delimiting temperatures of both main phase transition and pre-transition vs. the lipid composition of the vesicle. Differential scanning calorimetry (DSC) studies, although subject to uncertainties in interpretation due to broad bands in lipid mixtures, allowed the validation of the temperature dependence of the ZP method for determining the phase transition and pre-transition temperatures. The system chosen was dipalmitoylphosphatidylcholine/dimyristoyl phosphatidylcholine (DMPC/DPPC), the most common combination in biological membranes. This work may be considered as a starting point for further research into more complex lipid mixtures with functional biological importance. PMID:26954086

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

    Science.gov (United States)

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

    2015-05-01

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

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

    Science.gov (United States)

    Guevara-Carrion, Gabriela; Janzen, Tatjana; Muñoz-Muñoz, Y. Mauricio; Vrabec, Jadran

    2016-03-01

    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.

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

    Science.gov (United States)

    Guevara-Carrion, Gabriela; Janzen, Tatjana; Muñoz-Muñoz, Y Mauricio; Vrabec, Jadran

    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. PMID:27036455

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

    International Nuclear Information System (INIS)

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

  14. Shock Compression of Cryogenic Noble Gas Mixtures: Xenon - Krypton

    Science.gov (United States)

    Root, Seth; Magyar, Rudolph; Lemke, Raymond; Mattsson, Thomas

    2013-06-01

    In past work, we have examined the multi-Mbar response of cryogenically cooled liquid xenon and liquid krypton measuring their Hugoniots to 8 Mbar. These results were utilized in the development of new EOS models for Xe and Kr to use in high energy density physics applications. The previous work demonstrated the usefulness of integrating high accuracy shock compression experiments with DFT to generate the basis for equation of state (EOS) models. In many physics applications, such as Z-pinch experiments, gas mixtures are used instead. However, we do not have reliable experimental data on these mixtures to provide informed decisions about the EOS models or mixture rules. To improve our understanding of mixtures at extreme conditions, we performed dynamic compression experiments using Sandia's Z - facility on a 70/30 molar ratio Kr/Xe cryogenically cooled liquid mixture. We measured the Hugoniot state and reshock state of the liquid mixture to several Mbar. The experimental data validated the DFT simulations for identical molar ratio mixtures. The combined experimental and DFT results are used to assess the EOS models and test the mixture rules. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Securities Administration under Contract No. DE-AC04-94AL85000.

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

    Science.gov (United States)

    Hossain, Md Uzzal; Rahman, Md Toufiqur; Ehsan, Md Qamrul

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Md. Uzzal Hossain

    2015-01-01

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

  17. Survival of Campylobacter jejuni in different gas mixtures

    DEFF Research Database (Denmark)

    Boysen, Louise; Knochel, Susanne; Rosenquist, Hanne

    2007-01-01

    Campylobacter jejuni in fresh chilled chicken meat is known to be a major risk factor for human gastrointestinal disease. In the present study, the survival under chilled conditions of different C. jejuni strains exposed to different gas mixtures usually used for gas packaging of food was examined....... jejuni were reduced by a minimum of 4.6 log(10) CFU mL(-1) over 21 days. When inoculated onto chicken fillets, the C. jejuni strains also died significantly faster in the oxygen-containing gas mixture, 70/30% O-2/CO2 (P <0.0001), reaching reductions of 2.0-2.6 log(10) CFU g(-1) after 8 days. In the gas...

  18. 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. PMID:25376978

  19. Effects of binary mixtures of inducers (toluene analogs) and of metals on bioluminescence induction of a recombinant bioreporter strain.

    Science.gov (United States)

    Kong, In Chul

    2014-10-13

    This paper investigated the effects of binary mixtures of bioluminescence inducers (toluene, xylene isomers, m-toluate) and of metals (Cu, Cd, As(III), As(V), and Cr) on bioluminescence activity of recombinant (Pm-lux) strain KG1206. Different responses and sensitivities were observed depending on the types and concentrations of mixtures of inducers or metals. In the case of inducer mixtures, antagonistic and synergistic modes of action were observed, whereas metal mixtures showed all three modes of action. Antagonistic mode of action was most common for mixtures of indirect inducers, which showed bioluminescence ranging from 29% to 62% of theoretically expected effects (P(E)). On the other hand, synergistic mode of action was observed for mixtures of direct and indirect inducers, which showed bioluminescence between 141% and 243% of P(E). In the case of binary metal mixtures, bioluminescence activities were ranged from 62% to 75% and 113% to 164% of P(E) for antagonistic and synergistic modes of action, respectively (p-values 0.0001-0.038). Therefore, mixture effects could not be generalized since they were dependent on both the types and concentrations of chemicals, suggesting that biomonitoring may constitute a better strategy by investigating types and concentrations of mixture pollutants at contaminated sites.

  20. Nonequilibrium and effect of gas mixtures in an atmospheric microplasma

    CERN Document Server

    Mariotti, Davide

    2010-01-01

    The gas and effective electron temperatures have been estimated for atmospheric microplasma by means of optical emission spectroscopy. The results have shown that the microplasma exhibits nonequilibrium and, as its size is reduced, the two temperatures depart from each other, enhancing the nonequilibrium characteristic. The effect of methane and oxygen concentrations has also been studied, showing that gas mixtures have an important effect on the microplasma state.

  1. Joint effects of heavy metal binary mixtures on seed germination, root and shoot growth, bacterial bioluminescence, and gene mutation

    Institute of Scientific and Technical Information of China (English)

    In Chul Kong

    2013-01-01

    This investigation was to assess the joint effects of metal binary mixtures on seed germination,root and shoot growth,bacterial bioluminescence,and gene mutation based on the one toxic unit (1 TU) approach.Different sensitivities and orders of toxicity of metal mixtures were observed among the bioassays.In general,mostly additive or antagonistic effects were observed,while almost no synergistic effects by the binary metal mixtures in all bioassays.Therefore,the combined effects of heavy metals in the different bioassays were difficult to generalize since they were dependent on both chemical type and the organism used in each bioassay.However,these results indicate that a battery of bioassays with mixture chemicals as opposed to just a single assay with single metal is a better strategy for the bioassessment of environmental pollutants.

  2. Stability and collapse of fermions in a binary dipolar boson-fermion 164Dy-161Dy mixture

    Science.gov (United States)

    Adhikari, S. K.

    2013-10-01

    We suggest a time-dependent mean-field hydrodynamic model for a binary dipolar boson-fermion mixture to study the stability and collapse of fermions in the 164Dy-161Dy mixture. The condition of stability of the dipolar mixture is illustrated in terms of phase diagrams. A collapse is induced in a disk-shaped stable binary mixture by jumping the interspecies contact interaction from repulsive to attractive by the Feshbach resonance technique. The subsequent dynamics is studied by solving the time-dependent mean-field model including three-body loss due to molecule formation in boson-fermion and boson-boson channels. Collapse and fragmentation in the fermions after subsequent explosions are illustrated. The anisotropic dipolar interaction leads to anisotropic fermionic density distribution during collapse. This study is carried out in three-dimensional space using realistic values of dipolar and contact interactions.

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

    Directory of Open Access Journals (Sweden)

    I. Binas

    2009-01-01

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

  4. Order parameter and its critical exponent for some binary mixtures showing induced nematic phase

    Science.gov (United States)

    Sarkar, Sudipta Kumar; Das, Malay Kumar

    2016-09-01

    Refractive index measurements as a function of temperature have been performed for an induced nematic binary system by means of thin prism technique. The temperature dependence of the birefringence (Δn) has been assessed from the measured refractive index data. A direct extrapolation method has been employed to determine the orientational order parameter for the investigated mixtures and the order parameter so obtained has also been compared with the mean field values. The Haller type fitting expression results in a relatively lower value of the order parameter critical exponent (β) compared to the theoretically predicted values. Therefore, a four-parameter power law expression, consistent with the mean field theory as well as the first-order character of the nematic-isotropic (N-I) phase transition have been used to explore the critical behavior of the order parameter near the N-I transition.

  5. Decomposition driven interface evolution for layers of binary mixtures: I. Model derivation and stratified base states

    CERN Document Server

    Thiele, Uwe; Frastia, Lubor

    2007-01-01

    A dynamical model is proposed to describe the coupled decomposition and profile evolution of a free surface film of a binary mixture. An example is a thin film of a polymer blend on a solid substrate undergoing simultaneous phase separation and dewetting. The model is based on model-H describing the coupled transport of the mass of one component (convective Cahn-Hilliard equation) and momentum (Navier-Stokes-Korteweg equations) supplemented by appropriate boundary conditions at the solid substrate and the free surface. General transport equations are derived using phenomenological non-equilibrium thermodynamics for a general non-isothermal setting taking into account Soret and Dufour effects and interfacial viscosity for the internal diffuse interface between the two components. Focusing on an isothermal setting the resulting model is compared to literature results and its base states corresponding to homogeneous or vertically stratified flat layers are analysed.

  6. Air-Driven Segregation in Binary Granular Mixtures with Same Size but Different Densities

    Institute of Scientific and Technical Information of China (English)

    LU Chang-Hong; SHI Qing-Fan; YANG Lei; SUN Gang

    2008-01-01

    We investigate the segregation effect of binary granular mixtures with the same size but different densities under vibration at different air pressures. Our experiments show that the segregation state is seriously dependent on the air pressure and there is a new type of partially segregated state at high air pressure, which has the characteristic that the lighter grains tend to stay at the bottom and form a pure layer, while heavier grains and remained lighter ones tend to rise and to form a mixed layer on the top of the system. We redefine the order parameter to study the variation of the segregation effect with the air pressure and vibration parameter in detail. Finally, the mechanism of the air-driven segregation is illustrated by the faster acceleration due to the airflow through the granular bed for lighter particles.

  7. 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.)

  8. 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.

  9. A study of the effects of macrosegregation and buoyancy-driven flow in binary mixture solidification

    Science.gov (United States)

    Sinha, S. K.; Sundararajan, T.; Garg, V. K.

    1993-01-01

    A generalized anisotropic porous medium approach is developed for modelling the flow, heat and mass transport processes during binary mixture solidification. Transient predictions are obtained using FEM, coupled with an implicit time-marching scheme, for solidification inside a two-dimensional rectangular enclosure. A parametric study focusing attention on the effects of solutal buoyancy and thermal buoyancy is presented. It is observed that three parameters, namely the thermal Rayleigh number, the solutal Rayleigh number, and the relative density change parameter, significantly alter the flow fields in the liquid and the mushy regions. Depending upon the nature of these flow fields, the solute enrichment caused by macrosegregation may occur in the top or the bottom region of the enclosure.

  10. 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.

  11. MONOMOLECULAR FILMS OF COPOLYMERS OF OXYETHYLENE AND OXYPROPYLENE,POLYPROPYLENE GLYCOL AND THEIR BINARY MIXTURES

    Institute of Scientific and Technical Information of China (English)

    LI Wailang; DING Faxiang; GU Tiren

    1989-01-01

    The behaviour of monolayers of copolymers of oxyethylene and oxypropylene (UH29 and UH68),polypropylene glycol (UHPPG) and their binary mixtures on air-water interface has been investigated carefully on compression -expansion cycles. The first compression isotherm is approximately an equilibrium one. In the UHPPG-UH29 and UHPPG -UH68 systems, the calculated average π-a curves based on simple additivity ofthe two individual components coincide with the experimental results reasonably well. It is suggested that the two components are miscible and form near- ideal solution at the air- water interface.The compression- expansion cycle experiments shows some degree of hysteresis. The order of degree of hysteresis for individual components is UH68 > UH29 > UHPPG. The explanation for the hysteresis is proposed.

  12. Densities, Viscosities, Speeds of Sound, and Refractive Indices of Binary Mixtures of 2-Octanol with Chlorobenzenes

    Science.gov (United States)

    Bhatia, Subhash C.; Sangwan, Jasbir; Rani, Ruman; Bhatia, Rachna

    2011-10-01

    Densities, ρ, viscosities, η, speeds of sound, u, and refractive indices, n D, of binary liquid mixtures of 2-octanol with 1,2-dichlorobenzene, 1,3-dichlorobenzene, and 1,2,4-trichlorobenzene have been measured over the entire range of composition at 298.15 K, 303.15 K, and 308.15 K and at atmospheric pressure. From the experimental data of the density, speed of sound, viscosity, and refractive index, the values of the excess molar volume, V E, deviations in isentropic compressibility, Δ κ S , and deviations in molar refraction, Δ R have been calculated. The calculated excess and deviation functions have been analyzed in terms of molecular interactions and structural effects.

  13. 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.

  14. Investigation of solids segregation of binary mixtures in a rotating drum at various Froude numbers

    Institute of Scientific and Technical Information of China (English)

    HE Yu-rong; MEN Yu-bin; LIU Yuan-chun; LIU Wen-tie; DING Yu-long

    2010-01-01

    To investigate the effect of the Froude number(Fr)on solid segregation in a rotating drum,a two dimensional mathematical modelling on solids behaviour in horizontally oriented rotating drums operated in rolling,cascading and cataracting modes has been carried out by using Euler-Euler multi-fluid model in Fluent(R)6.2 environment.Small particles and big particles are used in the work as binary mixtures to investigate segregation characteristics.The effect of Froude number(rotating velocity)on the flow field is investigated.It is found that the model captures the main features of solids motion and segregation in the drum and numerical results agree well with limited experimental data for solid velocity.

  15. A comparative study of non-linearity parameter for binary liquid mixtures

    Indian Academy of Sciences (India)

    J D Pandey; Ranjan Dey; Vinay Sanguri; Jyotsna Chhabra; Tanuja Nautiyal

    2005-09-01

    The present investigation comprises of theoretical evaluation of acoustic non-linearity parameter, / for equimolar binary mixtures, viz. chlorobenzene or 1-chloronaphthalene with a series of normal alkanes (n-C, = 6, 8, 10, 12, 14, 16), and with a series of highly branched alkanes (br-C, = 6, 8, 12, 16), viz. 2,2-dimethylbutane (br-C6), 2,2,4-trimethylpentane (br-C8), 2,2,4,6,6-pentamethylheptane (br-C12) and 2,2,4,4,6,8,8-heptamethylnonane (br-C16). Tong and Dong method, ther- moacoustical method, Hartmann relation and Ballou relation have been employed to evaluate /. A comparative study of / values obtained from the aforementioned methods has been made. The results are discussed on the basis of structural orientations of normal and branched alkanes.

  16. Effects of the Wetting Particles on Phase Separation of Binary Mixtures

    Institute of Scientific and Technical Information of China (English)

    LIU Ji-Wen; MA Yu-qiang

    2000-01-01

    We study phase separation of binary mixtures in the presence of mobile particles by the lattice Monte Carlo simulation. The presence of mobile particles changes tile morphology of the domain growth, in agreement with earlier experimental result. By varying the wetting interaction strength, we can control the speed of phase separation, and find a critical wetting strength beyond which the growth of the domains slows down. We propose a novel scaling function which describes the growth of the domain size L(t) as a function of time. It suggests an applicable way to tune the speed of phase separation by the coupling between the phase decomposition and the mobile particle-wetting process.

  17. Benchmark solutions for transport in $d$-dimensional Markov binary mixtures

    CERN Document Server

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

    2016-01-01

    Linear particle transport in stochastic media is key to such relevant applications as neutron diffusion in randomly mixed immiscible materials, light propagation through engineered optical materials, and inertial confinement fusion, only to name a few. We extend the pioneering work by Adams, Larsen and Pomraning \\cite{benchmark_adams} (recently revisited by Brantley \\cite{brantley_benchmark}) by considering a series of benchmark configurations for mono-energetic and isotropic transport through Markov binary mixtures in dimension $d$. The stochastic media are generated by resorting to Poisson random tessellations in $1d$ slab, $2d$ extruded, and full $3d$ geometry. For each realization, particle transport is performed by resorting to the Monte Carlo simulation. The distributions of the transmission and reflection coefficients on the free surfaces of the geometry are subsequently estimated, and the average values over the ensemble of realizations are computed. Reference solutions for the benchmark have never be...

  18. Composition dependence of the glass forming ability in binary mixtures: The role of demixing entropy

    Science.gov (United States)

    Nandi, Ujjwal Kumar; Banerjee, Atreyee; Chakrabarty, Suman; Bhattacharyya, Sarika Maitra

    2016-07-01

    We present a comparative study of the glass forming ability of binary systems with varying composition, where the systems have similar global crystalline structure (CsCl+fcc). Biased Monte Carlo simulations using umbrella sampling technique show that the free energy cost to create a CsCl nucleus increases as the composition of the smaller particles is decreased. We find that systems with comparatively lower free energy cost to form CsCl nucleus exhibit more pronounced pre-crystalline demixing near the liquid/crystal interface. The structural frustration between the CsCl and fcc crystal demands this demixing. We show that closer to the equimolar mixture, the entropic penalty for demixing is lower and a glass forming system may crystallize when seeded with a nucleus. This entropic penalty as a function of composition shows a non-monotonic behaviour with a maximum at a composition similar to the well known Kob-Anderson (KA) model. Although the KA model shows the maximum entropic penalty and thus maximum frustration against CsCl formation, it also shows a strong tendency towards crystallization into fcc lattice of the larger "A" particles which can be explained from the study of the energetics. Thus for systems closer to the equimolar mixture although it is the requirement of demixing which provides their stability against crystallization, for KA model it is not demixing but slow dynamics and the presence of the "B" particles make it a good glass former. The locally favoured structure around "B" particles is quite similar to the CsCl structure and the incompatibility of CsCl and fcc hinders the fcc structure growth in the KA model. Although the glass forming binary systems studied here are quite similar, differing only in composition, we find that their glass forming ability cannot be attributed to a single phenomenon.

  19. Solubility and solution thermodynamics of 2,5-thiophenedicarboxylic acid in (water + ethanol) binary solvent mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang; Zhang, Qi; Cao, Cuicui; Cheng, Limin [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China); Shi, Ying [Taiyuan Qiaoyou Chemical Industrial Co. Ltd., Taiyuan 030025 (China); Yang, Wenge [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China); Hu, Yonghong, E-mail: yonghonghu11@126.com [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China)

    2014-09-20

    Highlights: • The solubility increased with increasing temperature. • The solubility decreased with the rise of the ratio of the water. • The solubility data were fitted using Apelblat equation, CNIBS/R–K and JA model. • The Gibbs energy, enthalpy and entropy were calculated by the van’t Hoff analysis. - Abstract: In this paper, we focused on solubility and solution thermodynamics of 2,5-thiophenedicarboxylic acid. By gravimetric method, the solubility of 2,5-thiophenedicarboxylic acid was measured in (water + ethanol) binary solvent mixtures from 278.15 K to 333.15 K under atmosphere pressure. The solubility data were fitted using modified Apelblat equation, a variant of the combined nearly ideal binary solvent/Redlich–Kister (CNIBS/R–K) model and Jouyban–Acree model. Computational results showed that the modified Apelblat equation has the lowest MD (mean deviation). In addition, the thermodynamic properties of the solution process, including the Gibbs energy, enthalpy, and entropy were calculated by the van’t Hoff analysis.

  20. Quantifying the rates of relaxation of binary mixtures of amorphous pharmaceuticals with isothermal calorimetry.

    Science.gov (United States)

    Alem, Naziha; Beezer, Anthony E; Gaisford, Simon

    2010-10-31

    While the use of isothermal calorimetry to quantify the rate of relaxation of one-phase amorphous pharmaceuticals, through application of models, is well documented, the resolution of the models to detect and quantify relaxation in systems containing two independent amorphous phases is not known. Addressing this knowledge gap is the focus of this work. Two fitting models were tested; the Kohlrausch-Williams-Watts model (KWW) and the modified-stretch exponential (MSE). The ability of each model to resolve relaxation processes in binary systems was determined with simulated calorimetric data. It was found that as long as the relaxation time constants of the relaxation processes were with 10(3) of each other, the models could determine that two events were occurring and could quantify the correct reaction parameters of each. With greater differences in the time constants, the faster process always dominates the data and the resolving power of the models is lost. Real calorimetric data were then obtained for two binary amorphous systems (sucrose-lactose and sucrose-indomethacin mixtures). The relaxation behaviour of all the single components was characterised as they relaxed individually to provide reference data. The ability of the KWW model to recover the expected relaxation parameters for two component data was impaired because of their inherently noisy nature. The MSE model reasonably recovered the expected parameters for each component for the sucrose-indomethacin system but not for the sucrose-lactose system, which may indicate a possible interaction in that case. PMID:20655372

  1. Density, conductivity, viscosity, and excess properties of (pyrrolidinium nitrate-based Protic Ionic Liquid + propylene carbonate) binary mixture

    OpenAIRE

    Pires, J; Timperman, L.; Jacquemin, J.; A. Balducci; Anouti, M.

    2013-01-01

    Density, ?, viscosity, ?, and conductivity, s, measurements of binary mixtures containing the pyrrolidinium nitrate Protic Ionic Liquid (PIL) and propylene carbonate (PC), are determined at the atmospheric pressure as a function of the temperature from (283.15 to 353.15) K and within the whole composition range. The temperature dependence of both the viscosity and conductivity of each mixture exhibits a non-Arrhenius behaviour, but is correctly fitted by using the Vogel–Tamman–Fulcher (VTF) e...

  2. Real-time composition determination of gas mixtures

    NARCIS (Netherlands)

    Lötters, J.C.; Wouden, van der E.J.; Groenesteijn, J.; Sparreboom, W.; Lammerink, T.S.J.; Wiegerink, R.J.

    2014-01-01

    We have designed and implemented an analytical calculation model with which we can real-time determine the composition of gas mixtures. The model is based upon a multi-parameter flow measurement system, consisting of a Coriolis and thermal flow sensor, a density meter and a pressure sensor. The syst

  3. Composition of Ar-Kr, Kr-Xe, and N2-Ar clusters produced by supersonic expansion of gas mixtures

    CERN Document Server

    Konotop, O P; Danylchenko, O G; Samovarov, V N

    2014-01-01

    An electron-diffraction study is made of the composition of binary Ar-Kr, Kr-Xe, and N2-Ar clusters of various size produced by expansion through a supersonic nozzle of gas mixtures with various component concentrations. The resulting clusters are shown to have compositions substantially different from those of the primary gas mixtures and dependent on cluster size. We have found that the key parameters needed for an analysis of cluster composition are the critical cluster radius and the heavier component concentration in the gas mixture which can be used to establish the regions of existence of homogeneous and heterogeneous clusters. These critical values determine the coefficient of the enrichment of clusters with the heavier component with respect to its concentration in the primary gas mixture. Theoretical relations are obtained which provide a good quantitative description of the experimental results and can be expected to be also valid for finding the composition of binary clusters of other van der Waal...

  4. 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.

  5. Prediction of Transport Properties of Liquid Ammonia and Its Binary Mixture with Methanol by Molecular Simulation

    Science.gov (United States)

    Guevara-Carrion, Gabriela; Vrabec, Jadran; Hasse, Hans

    2012-03-01

    Transport properties of ammonia and of the binary mixture ammonia + methanol are predicted for a broad range of liquid states by molecular dynamics (MD) simulation on the basis of rigid, non-polarizable molecular models of the united-atom type. These models were parameterized in preceding work using only experimental vapor-liquid equilibrium data. The self- and the Maxwell-Stefan (MS) diffusion coefficients as well as the shear viscosity are obtained by equilibrium MD and the Green-Kubo formalism. Non-equilibrium MD is used for the thermal conductivity. The transport properties of liquid ammonia are predicted for temperatures between 223 K and 473 K up to pressures of 200 MPa and are compared to experimental data and correlations thereof. Generally, good agreement is achieved. The predicted self-diffusion coefficient as well as the shear viscosity deviates on average by less than 15 % from the experiment and the thermal conductivity by less than 6 %. Furthermore, the self- and the MS transport diffusion coefficients as well as the shear viscosity of the liquid mixture ammonia + methanol are studied at different compositions and compared to the available experimental data.

  6. Thermodynamic Correlations, k – Exponents, Speed of Sound, and COP Data for Binary Refrigerant Mixtures

    Directory of Open Access Journals (Sweden)

    M. Damanakis

    2004-03-01

    Full Text Available

    Our study covers thermodynamic performance quantities for binary refrigerant mixtures of R-32/R-134a with compositions of 20/80%, 30/70%, 40/60% by mass for a wide range of thermodynamic conditions (pressure: 0.2 - 3.0 MPa, temperature: 240 - 480 oK and saturated conditions. The primary thrust of the study is the calculation of coefficient of performance (COP values for refrigeration systems. Additional attention is also given to speed of sound data and to isentropic process changes.

    The relevant COPs are derived based on a simplified reference refrigeration cycle with one stage compression and throttling, saturated vapor and no liquid sub-cooling prior to the throttling valve. The COP values are given for various condensing and evaporating temperatures. For all calculations, a Peng – Robinson type equation of state is used to determine the necessary fluid properties. The enthalpy, entropy, and constant-pressure and constant-volume specific heats as well as the k-type isentropic change exponents are presented for all mixtures for the range of thermodynamics conditions listed above. Comparisons are made illustrating the influence of pressure and temperature on the k-type exponents kp,v, kT,v, and kp,T, and on the ratio of specific heats k (k = cp/cv. Furthermore, graphs with speed of sound data for this extended range of conditions are also given.

  7. Suppression of turbulent energy cascade due to phase separation in homogenous binary mixture fluid

    Science.gov (United States)

    Takagi, Youhei; Okamoto, Sachiya

    2015-11-01

    When a multi-component fluid mixture becomes themophysically unstable state by quenching from well-melting condition, phase separation due to spinodal decomposition occurs, and a self-organized structure is formed. During phase separation, free energy is consumed for the structure formation. In our previous report, the phase separation in homogenous turbulence was numerically simulated and the coarsening process of phase separation was discussed. In this study, we extended our numerical model to a high Schmidt number fluid corresponding to actual polymer solution. The governing equations were continuity, Navier-Stokes, and Chan-Hiliard equations as same as our previous report. The flow filed was an isotropic homogenous turbulence, and the dimensionless parameters in the Chan-Hilliard equation were estimated based on the thermophysical condition of binary mixture. From the numerical results, it was found that turbulent energy cascade was drastically suppressed in the inertial subrange by phase separation for the high Schmidt number flow. By using the identification of turbulent and phase separation structure, we discussed the relation between total energy balance and the structures formation processes. This study is financially supported by the Grand-in-Aid for Young Scientists (B) (No. T26820045) from the Ministry of Education, Cul-ture, Sports, Science and Technology of Japan.

  8. Investigation of compressibility and compactibility parameters of roller compacted Theophylline and its binary mixtures.

    Science.gov (United States)

    Hadžović, Ervina; Betz, Gabriele; Hadžidedić, Seherzada; El-Arini, Silvia Kocova; Leuenberger, Hans

    2011-09-15

    Roller compaction is a dry granulation method which results in tablets with inferior tensile strength comparing to direct compaction. The effect of roller compaction on compressibility and compactibility of tablets prepared from Theophylline anhydrate powder, Theophylline anhydrate fine powder and Theophylline monohydrate was investigated by measuring tensile strength of tablets as well as calculating compressibility and compactibility parameters by Leuenberger equation. The tablets under the same conditions were prepared by direct compaction and roller compaction. The binary mixtures of Theophylline anhydrate powder, Theophylline anhydrate fine powder, Theophylline monohydrate and microcrystalline cellulose were prepared in order to determine the optimal ratio of active material and excipients which delivers a sufficient mechanical strength of tablets. Tensile strength of MCC tablets and compactibility parameters calculated by Leuenberger equation after roller compaction was significantly decreased, while THAP, THAFP and THMO tablets showed only a minor reduction in compactibility and compressibility. Adding MCC to a mixture with Theophylline showed that the right choice and ratio of excipients can enable a sufficient mechanical strength of the tablets after roller compaction. PMID:21704142

  9. 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...

  10. ANALYSIS OF KINETIC DATA FOR REACTIONS IN BINARY AQUEOUS MIXTURES USING KIRKWOOD-BUFF INTEGRAL-FUNCTIONS CHARACTERIZING PREFERENTIAL SOLVATION

    NARCIS (Netherlands)

    BLANDAMER, MJ; BURGESS, J; ENGBERTS, JBFN; WARRICK, P

    1992-01-01

    The basis is described Of a method for analyzing the dependence of rate constants on solvent composition using Kirkwood-Buff integral functions. The background to the treatment is examined with reference to the analysis of thermodynamic properties of binary aqueous mixtures. Procedures are outlined

  11. Dielectric relaxation in ionic liquid/dipolar solvent binary mixtures: A semi-molecular theory.

    Science.gov (United States)

    Daschakraborty, Snehasis; Biswas, Ranjit

    2016-03-14

    A semi-molecular theory is developed here for studying dielectric relaxation (DR) in binary mixtures of ionic liquids (ILs) with common dipolar solvents. Effects of ion translation on DR time scale, and those of ion rotation on conductivity relaxation time scale are explored. Two different models for the theoretical calculations have been considered: (i) separate medium approach, where molecularities of both the IL and dipolar solvent molecules are retained, and (ii) effective medium approach, where the added dipolar solvent molecules are assumed to combine with the dipolar ions of the IL, producing a fictitious effective medium characterized via effective dipole moment, density, and diameter. Semi-molecular expressions for the diffusive DR times have been derived which incorporates the effects of wavenumber dependent orientational static correlations, ion dynamic structure factors, and ion translation. Subsequently, the theory has been applied to the binary mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) with water (H2O), and acetonitrile (CH3CN) for which experimental DR data are available. On comparison, predicted DR time scales show close agreement with the measured DR times at low IL mole fractions (x(IL)). At higher IL concentrations (x(IL) > 0.05), the theory over-estimates the relaxation times and increasingly deviates from the measurements with x(IL), deviation being the maximum for the neat IL by almost two orders of magnitude. The theory predicts negligible contributions to this deviation from the x(IL) dependent collective orientational static correlations. The drastic difference between DR time scales for IL/solvent mixtures from theory and experiments arises primarily due to the use of the actual molecular volume (V(mol)(dip)) for the rotating dipolar moiety in the present theory and suggests that only a fraction of V(mol)(dip) is involved at high x(IL). Expectedly, nice agreement between theory and experiments appears when

  12. Dielectric relaxation in ionic liquid/dipolar solvent binary mixtures: A semi-molecular theory

    Science.gov (United States)

    Daschakraborty, Snehasis; Biswas, Ranjit

    2016-03-01

    A semi-molecular theory is developed here for studying dielectric relaxation (DR) in binary mixtures of ionic liquids (ILs) with common dipolar solvents. Effects of ion translation on DR time scale, and those of ion rotation on conductivity relaxation time scale are explored. Two different models for the theoretical calculations have been considered: (i) separate medium approach, where molecularities of both the IL and dipolar solvent molecules are retained, and (ii) effective medium approach, where the added dipolar solvent molecules are assumed to combine with the dipolar ions of the IL, producing a fictitious effective medium characterized via effective dipole moment, density, and diameter. Semi-molecular expressions for the diffusive DR times have been derived which incorporates the effects of wavenumber dependent orientational static correlations, ion dynamic structure factors, and ion translation. Subsequently, the theory has been applied to the binary mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) with water (H2O), and acetonitrile (CH3CN) for which experimental DR data are available. On comparison, predicted DR time scales show close agreement with the measured DR times at low IL mole fractions (xIL). At higher IL concentrations (xIL > 0.05), the theory over-estimates the relaxation times and increasingly deviates from the measurements with xIL, deviation being the maximum for the neat IL by almost two orders of magnitude. The theory predicts negligible contributions to this deviation from the xIL dependent collective orientational static correlations. The drastic difference between DR time scales for IL/solvent mixtures from theory and experiments arises primarily due to the use of the actual molecular volume ( Vmol dip ) for the rotating dipolar moiety in the present theory and suggests that only a fraction of Vmol dip is involved at high xIL. Expectedly, nice agreement between theory and experiments appears when experimental

  13. Asymmetrical phase separation and gelation in binary mixtures of oppositely charged colloids

    Science.gov (United States)

    Zong, Yiwu; Yuan, Guangcui; Han, Charles C.

    2016-07-01

    Two types of colloidal particles, which are nearly the same in chemical composition but carry opposite surface charges, are mixed in water. Depending on the relative proportion of the oppositely charged particles, the process of aggregation leads to the formation of discrete clusters of various sizes in dilute dispersions, and to the development of particle gel networks in more concentrated systems. Due to the significant difference in the absolute values of surface charges (negative particle: -48 mV, positive particle: +24 mV), the phase separation and the gelation behaviors are asymmetric with respect to the mixing ratio. Mixtures with excess negative particles are more stable, while mixtures with excess positive particles are easily affected by phase separation. The hetero-aggregation triggered by the addition of microscopically large macro-ions is similar to what is often observed in a mono-component charged colloidal system, i.e., phase separation occurs through addition of small electrolyte ions. Within the concentration region investigated here, it is clear that the gel line is buried inside the phase separation region. Gelation occurs only when the number and size of the clusters are large and big enough to connect up into a space-spanning network. Our results indicate that, in this binary mixture of oppositely charged colloids, although the interaction between unlike species is attractive and that between like species is repulsive, the onset of gelation is in fact governed by the equilibrium phase separation, as in the case of purely attractive systems with short-range isotropic interaction.

  14. Enhanced KR-Fundamental Measure Functional for Inhomogeneous Binary and Ternary Hard Sphere Mixtures

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shi-Qi

    2011-01-01

    An enhanced KR-fundarnentai measure functional (FMF) is elaborated and employed to investigate binary and ternary hard sphere fluids near a planar hard wall or confined within two planar hard wails separated by certain interval.The present enhanced KR-FMF incorporates respectively, for aim of comparison, a recent 3rd-order expansion equation of state (EOS) and a Boublik's extension of Kolafa's EOS for HS mixtures.It is indicated that the two versions of the EOS lead to, in the framework of the enhanced KR-FMF, similar density profiles, but the 3rd-order EOS is more consistent with an exact scaled particle theory (SPT) relation than the BK EOS.Extensive comparison between the enhanced KR-FMF-3rd-order EOS predictions and corresponding density profiles produced in different periods indicates the excellent performance of the present enhanced KR-FMF-3rd-order EOS in comparison with other available density functional approximations (DFAs).There are two anomalous situations from whose density profiles all DFAs studied deviate significantly; however, subsequent new computer simulation results for state conditions similar to the two anomalous situations are in very excellent agreement with the present enhanced KR-FMF-3rd-order EOS.The present paper indicates that (i) the validity of the “naive” substitution elaborated in the present paper and peculiar to the original KR-FMF is still in operation even if inhomogeneous mixtures are being dealt with; (ii) the high accuracy and seff-consistency of the third order EOS seem to allow for application of the KR-FMF-third order EOS to more severe state conditions; and (iii) the “naive” substitution enables very easy the combination of the original KR-FMF with future's more accurate but potentially more complicated EOS of hard sphere mixtures.

  15. Asymmetrical phase separation and gelation in binary mixtures of oppositely charged colloids.

    Science.gov (United States)

    Zong, Yiwu; Yuan, Guangcui; Han, Charles C

    2016-07-01

    Two types of colloidal particles, which are nearly the same in chemical composition but carry opposite surface charges, are mixed in water. Depending on the relative proportion of the oppositely charged particles, the process of aggregation leads to the formation of discrete clusters of various sizes in dilute dispersions, and to the development of particle gel networks in more concentrated systems. Due to the significant difference in the absolute values of surface charges (negative particle: -48 mV, positive particle: +24 mV), the phase separation and the gelation behaviors are asymmetric with respect to the mixing ratio. Mixtures with excess negative particles are more stable, while mixtures with excess positive particles are easily affected by phase separation. The hetero-aggregation triggered by the addition of microscopically large macro-ions is similar to what is often observed in a mono-component charged colloidal system, i.e., phase separation occurs through addition of small electrolyte ions. Within the concentration region investigated here, it is clear that the gel line is buried inside the phase separation region. Gelation occurs only when the number and size of the clusters are large and big enough to connect up into a space-spanning network. Our results indicate that, in this binary mixture of oppositely charged colloids, although the interaction between unlike species is attractive and that between like species is repulsive, the onset of gelation is in fact governed by the equilibrium phase separation, as in the case of purely attractive systems with short-range isotropic interaction. PMID:27394122

  16. Effective Viscosity of a Near-Critical Binary Fluid Mixture with Colloidal Particles Dispersed Dilutely under Weak Shear

    Science.gov (United States)

    Fujitani, Youhei

    2014-08-01

    We consider a spherical liquid droplet immersed in a near-critical binary fluid mixture whose components interact with the droplet slightly unequally. Assuming uniform viscosity of the mixture, we use the Gaussian free-energy functional to calculate the pressure and velocity fields occurring when a weak linear shear flow is imposed far from the droplet. These fields in the limit of infinite droplet viscosity give those for a rigid sphere. Using these fields, we calculate the effective viscosity emerging when identical droplets or rigid spheres are dilutely dispersed in the mixture.

  17. Characterization of Dimethylsulfoxide / Glycerol Mixtures: A Binary Solvent System for the Study of "Friction-Dependent" Chemical Reactivity

    CERN Document Server

    Angulo, Gonzalo; Gerecke, Mario; Grampp, Günter; Jeannerat, Damien; Milkiewicz, Jadwiga; Mitrev, Yavor; Radzewicz, Czesław; Rosspeintner, Arnulf; Vauthey, Eric; Wnuk, Paweł

    2016-01-01

    The properties of binary mixtures of dimethylsulfoxide and glycerol, measured by several techniques, are reported. Special attention is given to those properties contributing or affecting chemical reactions. In this respect the investigated mixture behaves as a relatively simple solvent and it is especially well suited for studies on the influence of viscosity in chemical reactivity. This is due to the relative invariance of the dielectric properties of the mixture. However, special caution must be taken with specific solvation, as the hydrogen-bonding properties of the solvent changes with the molar fraction of glycerol.

  18. Characterization of dimethylsulfoxide/glycerol mixtures: a binary solvent system for the study of "friction-dependent" chemical reactivity.

    Science.gov (United States)

    Angulo, Gonzalo; Brucka, Marta; Gerecke, Mario; Grampp, Günter; Jeannerat, Damien; Milkiewicz, Jadwiga; Mitrev, Yavor; Radzewicz, Czesław; Rosspeintner, Arnulf; Vauthey, Eric; Wnuk, Paweł

    2016-07-21

    The properties of binary mixtures of dimethylsulfoxide and glycerol, measured using several techniques, are reported. Special attention is given to those properties contributing or affecting chemical reactions. In this respect the investigated mixture behaves as a relatively simple solvent and it is especially well suited for studies on the influence of viscosity on chemical reactivity. This is due to the relative invariance of the dielectric properties of the mixture. However, special caution must be taken with specific solvation, as the hydrogen-bonding properties of the solvent change with the molar fraction of glycerol. PMID:27339434

  19. Low temperature catalytic combustion of natural gas - hydrogen - air mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Newson, E.; Roth, F. von; Hottinger, P.; Truong, T.B. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The low temperature catalytic combustion of natural gas - air mixtures would allow the development of no-NO{sub x} burners for heating and power applications. Using commercially available catalysts, the room temperature ignition of methane-propane-air mixtures has been shown in laboratory reactors with combustion efficiencies over 95% and maximum temperatures less than 700{sup o}C. After a 500 hour stability test, severe deactivation of both methane and propane oxidation functions was observed. In cooperation with industrial partners, scaleup to 3 kW is being investigated together with startup dynamics and catalyst stability. (author) 3 figs., 3 refs.

  20. Equilibrium water content measurements for acid gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, R.A.; Fitzpatrick, E.; Bernard, F.; Wan, H.H.; Lesage, K.L.; Davis, P.M.; Clark, P.D. [Alberta Sulphur Research Ltd., Calgary, AB (Canada)

    2009-07-01

    An accurate understanding of acid gas and water equilibrium is needed in order to design safe acid gas injection facilities. This paper described a joint industry project conducted to measure the water content of acid gas mixtures under moderate pressures and temperatures. The study has accumulated over 160 data points. Techniques used to obtain the measurements have included visual dew point determination for liquid acid gas and hydrates; the equilibration of samples in stirred autoclaves; basic static equilibration cells; and an isolated floating piston with a micro-sampler used to inject gaseous and liquid acid gas phases. As a result of the project, a high pressure micro-sampling technique has been developed to pressure limits of 1000 bar. 33 refs., 2 tabs., 10 figs.

  1. Gas adsorption and gas mixture separations using mixed-ligand MOF material

    Science.gov (United States)

    Hupp, Joseph T.; Mulfort, Karen L.; Snurr, Randall Q.; Bae, Youn-Sang

    2011-01-04

    A method of separating a mixture of carbon dioxiode and hydrocarbon gas using a mixed-ligand, metal-organic framework (MOF) material having metal ions coordinated to carboxylate ligands and pyridyl ligands.

  2. 混合制冷工质核态沸腾的传热研究%Heat transfer in nucleate pool boiling of binary and ternary refrigerant mixtures

    Institute of Scientific and Technical Information of China (English)

    赵耀华; 刁彦华; 鹤田隆治; 西川日出男

    2004-01-01

    Heat transfer coefficients in nucleate pool boiling were measured on a horizontal copper surface for refrigerants,HFC-134a,HFC-32,and HFC-125,their binary and ternary mixtures under saturated conditions at 0.9MPa.Compared to pure components,both binary and ternary mixtures showed lower heat transfer coefficients.This deterioration was more pronounced as heat flux was increased.Experimental data were compared with some empirical and semi-empirical correlations available in literature.For binary mixture,the accuracy of the correlations varied considerably with mixtures and the heat flux.Experimental data for HFC-32/134a/125 were also compared with available correlated equation obtained by Thome.For ternary mixture,the boiling range of binary mixture composed by the pure fluids with the lowest and the medium boiling points,and their concentration difference had important effects on boiling heat transfer coefficients.

  3. Powder properties of binary mixtures of chloroquine phosphate with lactose and dicalcium phosphate

    Directory of Open Access Journals (Sweden)

    Michael Ayodele Odeniyi

    2010-09-01

    Full Text Available A study was conducted on the packing and cohesive properties of chloroquine phosphate in binary mixtures with lactose and dicalcium phosphate powders. The maximum volume reduction due to packing as expressed by the Kawakita constant, a, and the angle of internal flow, θ, were the assessment parameters. The individual powders were characterized for their particle size and shape using an optical microscope. Binary mixtures of various proportions of chloroquine phosphate with lactose and dicalcium phosphate powders were prepared. The bulk and tapped densities, angles of repose and internal flow, as well as compressibility index of the materials were determined using appropriate parameters. The calculated and determined values of maximum volume reduction for the binary mixtures were found to differ significantly (PRealizou-se estudo das propriedades de empacotamento e de coesão do fosfato de cloroquina em misturas binárias com lactose e fosfato dicálcico em pó. O volume máximo de redução devido ao empacotamento, segundo expresso pela constante de Kawakita, a, e o ângulo de fluxo interno, θ, foram os parâmetros de avaliação. Os pós individuais foram caracterizados por seu tamanho e forma de partículas, utilizando microscópio óptico. Prepararam-se misturas binárias de várias proporções de fosfato de cloroquine e lactose e fosfato dicálcico em pó. As densidades de bulk and tapped, os ângulos de repouso e de fluxo interno e o índice de compressibilidade dos materiais foram determinados utilizando-se parâmetros apropriados. Os valores calculados e determinados do volume máximo de redução para as misturas binárias mostraram-se significativamente diferentes (P< 0,05, sendo o traçado de Kawakita mais confiável na determinação das propriedades de empacotamento. O tipo de diluente influenciou as propriedades de fluxo das misturas com fosfato dicálcico, dando resultados previsíveis, enquanto as misturas contendo lactose

  4. 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

  5. Experimental Study of Gas Explosions in Hydrogen Sulfide-Natural Gas-Air Mixtures

    Directory of Open Access Journals (Sweden)

    André Vagner Gaathaug

    2014-01-01

    Full Text Available An experimental study of turbulent combustion of hydrogen sulfide (H2S and natural gas was performed to provide reference data for verification of CFD codes and direct comparison. Hydrogen sulfide is present in most crude oil sources, and the explosion behaviour of pure H2S and mixtures with natural gas is important to address. The explosion behaviour was studied in a four-meter-long square pipe. The first two meters of the pipe had obstacles while the rest was smooth. Pressure transducers were used to measure the combustion in the pipe. The pure H2S gave slightly lower explosion pressure than pure natural gas for lean-to-stoichiometric mixtures. The rich H2S gave higher pressure than natural gas. Mixtures of H2S and natural gas were also studied and pressure spikes were observed when 5% and 10% H2S were added to natural gas and also when 5% and 10% natural gas were added to H2S. The addition of 5% H2S to natural gas resulted in higher pressure than pure H2S and pure natural gas. The 5% mixture gave much faster combustion than pure natural gas under fuel rich conditions.

  6. Hydroprocesssing of light gas oil - rape oil mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Walendziewski, Jerzy; Stolarski, Marek; Luzny, Rafal; Klimek, Bartlomiej [Faculty of Chemistry, Wroclaw University of Technology, ul. Gdanska 7/9, 50-310 Wroclaw (Poland)

    2009-05-15

    Two series of experiments of hydroprocessing of light gas oil - rape oil mixtures were carried out. The reactor feed was composed of raw material: first series - 10 wt.% rape oil and 90 wt.% of diesel oil; second series - 20 wt.% rape oil and 80 wt.% of diesel oil. Hydroprocessing of both mixtures was performed with the same parameter sets, temperature (320, 350 and 380 C), hydrogen pressure 3 and 5 MPa, LHSV = 2 h{sup -} {sup 1} and hydrogen feed ratio of 500 Nm{sup 3}/m{sup 3}. It was stated that within limited range it is possible to control vegetable oil hydrogenolysis in the presence of light gas oil fraction (diesel oil boiling range) through the proper selection of the process parameters. Hydrogenolysis of ester bonds and hydrogenation of olefinic bonds in vegetable oils are the main reactions in the process. Basic physicochemical properties of the obtained hydroprocessed products are presented. (author)

  7. Plasma polymerization of an ethylene-nitrogen gas mixture

    Science.gov (United States)

    Hudis, M.; Wydeven, T.

    1975-01-01

    A procedure has been developed whereby nitrogen can be incorporated into an organic film from an ethylene-nitrogen gas mixture using an internal electrode capacitively coupled radio frequency reactor. The presence of nitrogen has been shown directly by infrared transmittance spectra and electron spectroscopic chemical analysis data, and further indirect evidence was provided by dielectric measurements and by the reverse osmosis properties of the film. Preparation of a nitrogen containing film did not require vapor from an organic nitrogen containing liquid monomer. Some control over the bonding and stoichiometry of the polymer film was provided by the added degree of freedom of the nitrogen partial pressure in the gas mixture. This new parameter strongly affected the dielectric properties of the plasma polymerized film and could affect the reverse osmosis behavior.

  8. 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

  9. Modeling high-pressure adsorption of gas mixtures on activated carbon and coal using a simplified local-density model.

    Science.gov (United States)

    Fitzgerald, James E; Robinson, Robert L; Gasem, Khaled A M

    2006-11-01

    The simplified local-density (SLD) theory was investigated regarding its ability to provide accurate representations and predictions of high-pressure supercritical adsorption isotherms encountered in coalbed methane (CBM) recovery and CO2 sequestration. Attention was focused on the ability of the SLD theory to predict mixed-gas adsorption solely on the basis of information from pure gas isotherms using a modified Peng-Robinson (PR) equation of state (EOS). An extensive set of high-pressure adsorption measurements was used in this evaluation. These measurements included pure and binary mixture adsorption measurements for several gas compositions up to 14 MPa for Calgon F-400 activated carbon and three water-moistened coals. Also included were ternary measurements for the activated carbon and one coal. For the adsorption of methane, nitrogen, and CO2 on dry activated carbon, the SLD-PR can predict the component mixture adsorption within about 2.2 times the experimental uncertainty on average solely on the basis of pure-component adsorption isotherms. For the adsorption of methane, nitrogen, and CO2 on two of the three wet coals, the SLD-PR model can predict the component adsorption within the experimental uncertainties on average for all feed fractions (nominally molar compositions of 20/80, 40/60, 60/40, and 80/20) of the three binary gas mixture combinations, although predictions for some specific feed fractions are outside of their experimental uncertainties. PMID:17073487

  10. Measurements of drift velocity in the ATLAS RPC gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Chiodini, G. [INFN, Sezione di Lecce, via Arnesano, 73100 Lecce (Italy); Coluccia, M.R. [INFN, Sezione di Lecce, via Arnesano, 73100 Lecce (Italy) and Universita degli Studi di Lecce, Dip. di Fisica, via Arnesano, 73100 Lecce (Italy)]. E-mail: coluccia@le.infn.it; Gorini, E. [INFN, Sezione di Lecce, via Arnesano, 73100 Lecce (Italy); Universita degli Studi di Lecce, Dip. di Fisica, via Arnesano, 73100 Lecce (Italy); Primavera, M. [INFN, Sezione di Lecce, via Arnesano, 73100 Lecce (Italy); Stella, S. [Universita degli Studi di Lecce, Dip. di Fisica, via Arnesano, 73100 Lecce (Italy)

    2006-08-15

    We present here some results on measurements of electron drift velocity as a function of the electric field in a single gap, avalanche operated, small size (10 x 20 cm{sup 2}) RPC filled with a ternary gas mixture (94.3 % C{sub 2}H{sub 2}F{sub 4}, 5 % C{sub 4}H{sub 10}, 0.3 % SF{sub 6}). A pulsed nitrogen laser is focused ({approx} 20 {mu}m spot size at the focus) inside the gas gap to generate primary ionization via double photon ionization process. Results are presented and discussed.

  11. Pentaglyme-K salt binary mixtures: phase behavior, solvate structures, and physicochemical properties.

    Science.gov (United States)

    Mandai, Toshihiko; Tsuzuki, Seiji; Ueno, Kazuhide; Dokko, Kaoru; Watanabe, Masayoshi

    2015-01-28

    We prepared a series of binary mixtures composed of certain K salts (KX) and pentaglyme (G5) with different salt concentrations and anionic species ([X](-): [(CF3SO2)2N](-) = [TFSA](-), [CF3SO3](-) = [TfO](-), [C4F9SO3](-) = [NfO](-), PF6(-), SCN(-)), and characterized them with respect to their phase diagrams, solvate structures, and physicochemical properties. Their phase diagrams and thermal stability strongly implied the formation of equimolar complexes. Single-crystal X-ray crystallography was performed on certain equimolar complexes, which revealed that G5 molecules coordinate to K(+) cations in a characteristic manner, like 18-crown-6 ether in the crystalline state, irrespective of the paired anions. The solvate structures in the molten state were elucidated by a combination of temperature-dependent Raman spectroscopy and X-ray crystallography. A drastic spectral variation was observed in the [K(G5)1][TfO] Raman spectra, indicating that solvate structures in the crystalline state break apart upon melting. The solvate stability of [K(G5)1]X is closely related to the ion-ion interaction of the parent salts. A stable solvate forms when the ion-dipole interaction between K(+) and G5 overwhelms the ion-ion interaction between K(+) and X(-). Furthermore, the physicochemical properties of certain equimolar mixtures were evaluated. A Walden plot clearly reflects the ionic nature of the molten equimolar complexes. Judging from the structural characteristics and dissociativity, we classified [K(G5)1]X into two groups, good and poor solvate ionic liquids. PMID:25501925

  12. Dielectric relaxation of binary polar liquid mixture measured in benzene at 10 GHz frequency

    Indian Academy of Sciences (India)

    S Sahoo; K Dutta; S Acharyya; S K Sit

    2008-03-01

    The dielectric relaxation times 's and dipole moments 's of the binary () polar liquid mixture of N,N-dimethyl acetamide (DMA) and acetone (Ac) dissolved in benzene (i) are estimated from the measured real ′ and imaginary ″ parts of complex high frequency conductivity * of the solution for different weight fractions 's of 0.0, 0.3, 0.5, 0.7 and 1.0 mole fractions of Ac and temperatures (25, 30, 35 and 40°C) respectively under 9.88 GHz electric field. 's are obtained from the ratio of slopes of ″ - and ′ - curves at → 0 as well as linear slope of ″ - ′ curves of the existing method (Murthy et al, 1989) in order to eliminate polar-polar interaction in the latter case. The calculated 's are in excellent agreement with the reported 's due to Gopalakrishna's method. 's are also estimated from slopes 's of total conductivity - curves at → 0 and the values agree well with the reported 's from G.K. method. The variation of 's and 's with of Ac reveals that solute-solute molecular association occurs within 0.0-0.3 of Ac beyond which solute-solvent molecular association is predicted. The theoretical dipole moments theo's are calculated from bond angles and bond moments to have exact 's only to show the presence of inductive, mesomeric and electromeric effects in the substituent polar groups. The thermodynamic energy parameters are estimated from ln () against 1/ linear curve from Eyring's rate theory to know the molecular dynamics of the system and to establish the fact that the mixture obeys the Debye-Smyth relaxation mechanism.

  13. 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-...

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

    Science.gov (United States)

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

    2016-09-01

    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. Project supported by the National Natural Science Foundation of China (Grant Nos. 51273133 and 51443004).

  15. Influence of Molecular Structure on the Ideality of Mixing in Micelles Formed in Binary Mixtures of Surface-Active Drugs.

    Science.gov (United States)

    Taboada; Attwood; Ruso; García; Sarmiento; Mosquera

    1999-08-15

    The influence of the structure of the hydrophobic group on the ideality of mixing in binary mixtures of surface active molecules has been investigated using combinations of amphiphilic penicillins. Critical concentrations (cc) of the binary mixtures of these anionic surfactants were determined by conductivity measurements as a function of the composition. The nonideality of mixing was evaluated using a regular solution approximation and expressed in terms of the interaction parameter, beta. Mixing in micelles formed in binary mixtures of the structurally similar penicillins cloxacillin, dicloxacillin, and flucloxacillin was ideal (beta = 0). In contrast, the combination of either cloxacillin or dicloxacillin with the penicillin nafcillin produced mixed micelles in which the mixing deviated from ideality (beta = +0.1 to +0.2). The positive values of beta for these systems indicated negative synergism between components of the mixtures that may be a consequence of the marked structural differences between the hydrophobic groups of these drugs. The composition of the mixed micelles was derived from the cc data by application of a theoretical treatment based on excess thermodynamic quantities. Copyright 1999 Academic Press.

  16. 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.

  17. Development of normalized spectra manipulating spectrophotometric methods for simultaneous determination of Dimenhydrinate and Cinnarizine binary mixture.

    Science.gov (United States)

    Lamie, Nesrine T; Yehia, Ali M

    2015-01-01

    Simultaneous determination of Dimenhydrinate (DIM) and Cinnarizine (CIN) binary mixture with simple procedures were applied. Three ratio manipulating spectrophotometric methods were proposed. Normalized spectrum was utilized as a divisor for simultaneous determination of both drugs with minimum manipulation steps. The proposed methods were simultaneous constant center (SCC), simultaneous derivative ratio spectrophotometry (S(1)DD) and ratio H-point standard addition method (RHPSAM). Peak amplitudes at isoabsorptive point in ratio spectra were measured for determination of total concentrations of DIM and CIN. For subsequent determination of DIM concentration, difference between peak amplitudes at 250 nm and 267 nm were used in SCC. While the peak amplitude at 275 nm of the first derivative ratio spectra were used in S(1)DD; then subtraction of DIM concentration from the total one provided the CIN concentration. The last RHPSAM was a dual wavelength method in which two calibrations were plotted at 220 nm and 230 nm. The coordinates of intersection point between the two calibration lines were corresponding to DIM and CIN concentrations. The proposed methods were successfully applied for combined dosage form analysis, Moreover statistical comparison between the proposed and reported spectrophotometric methods was applied. PMID:26037499

  18. Riemann problem for one-dimensional binary gas enhanced coalbed methane process

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    With an extended Langmuir isotherm, a Riemann problem for one-dimensional binary gas enhanced coalbed methane (ECBM) process is investigated. A new analytical solution to the Riemann problem, based on the method of characteristics, is developed by introducing a gas selectivity ratio representing the gas relative sorption affinity. The influence of gas selectivity ratio on the enhanced coalbed methane processes is identified.

  19. Laser beam characterization of the ATLAS RPC gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Chiodini, G. [INFN Lecce, via per Arnesano, 73100 Lecce (Italy); Coluccia, M.R.; Gorini, E. [INFN Lecce, via per Arnesano, 73100 Lecce (Italy); Dipartimento di Fisica, Universita degli Studi di Lecce, via per Arnesano, 73100 Lecce (Italy); Grancagnolo, F.; Primavera, M. [INFN Lecce, via per Arnesano, 73100 Lecce (Italy)

    2007-10-15

    A measurement of the electrons drift velocity in C{sub 2}H{sub 2}F{sub 4}-based gas mixture has been performed and results have been compared with calculations. Primary ionization is induced in the gas via double photon ionization process by mean of a pulsed Nitrogen laser. The results of the drift velocity, obtained at room temperature and normal pressure, are presented as a function of the electric field strength. To perform the measurements we used a small sized RPC prototype with a 2 mm gas gap delimited by 2mm-thick linseed-oil-treated bakelite plates with resistivity of about 1.71x10{sup 10}{omega} cm at 20{sup o}C.

  20. Laser beam characterization of the ATLAS RPC gas mixture

    International Nuclear Information System (INIS)

    A measurement of the electrons drift velocity in C2H2F4-based gas mixture has been performed and results have been compared with calculations. Primary ionization is induced in the gas via double photon ionization process by mean of a pulsed Nitrogen laser. The results of the drift velocity, obtained at room temperature and normal pressure, are presented as a function of the electric field strength. To perform the measurements we used a small sized RPC prototype with a 2 mm gas gap delimited by 2mm-thick linseed-oil-treated bakelite plates with resistivity of about 1.71x1010Ω cm at 20oC

  1. Composite-fermionization of the mixture composed of Tonks gas and Fermi gas

    Institute of Scientific and Technical Information of China (English)

    Hao Ya-Jiang

    2011-01-01

    This paper investigates the ground-state properties of the mixture composed of the strongly interacting TonksGirardeau gas and spin polarized Fermi gas confined in one-dimensional harmonic traps, where the interaction between the Bose atoms and Fermi atoms is tunable. With a generalized Bose-Fermi transformation the mixture is mapped into a two-component Fermi gas. The homogeneous Fermi gas is exactly solvable by the Bethe-ansatz method and the ground state energy density can be obtained. Combining the ground-state energy function of the homogeneous system with local density approximation it obtains the ground-state density distributions of inhomogeneous mixture. It is shown that with the increase in boson-fermion interaction, the system exhibits composite-fermionization crossover.

  2. Densities, Excess Molar Volumes, Viscosities, and Refractive Indices of Binary Mixtures of n-Butyl Acetate with 1-Chloroalkanes (C4-C8) at 298.15 K

    Science.gov (United States)

    Iloukhani, H.; Khanlarzadeh, K.; Rakhshi, M.

    2011-03-01

    Densities, viscosities, and refractive indices of binary mixtures of n-butyl acetate (1) +1-chlorobutane (2), +1-chloropentane (2), +1-chlorohexane (2), +1-chloroheptane (2), and +1-chlorooctane (2) were measured at 298.15 K for the liquid region and at ambient pressure for the whole composition range. The excess molar volumes V E were calculated from experimental densities. McAllister's three-body interaction, and Hind and Grunberg-Nissan models are used for correlating the viscosity of binary mixtures. The experimental data of binaries are analyzed to discuss the nature and strength of intermolecular interactions in these mixtures.

  3. 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

    2015-11-01

    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.

  4. Parametrization of coarse grained force fields for dynamic property of ethylene glycol oligomers/water binary mixtures

    CERN Document Server

    Yamazaki, Tamio

    2011-01-01

    To evaluate shear viscosity of ehylene glycol oligomers (EGO)/water binary mixture by means of coarse-grained molecular dynamics (CG-MD) simulations, we proposed the self-diffusion-coefficient-based parameterization of non-bonded interactions among CG particles. Our parameterization procedure consists of three steps: 1)determination of bonded potentials, 2)scaling for time and solvent diffusivity, and 3)optimization of Lennard-Jones parameters to reproduce experimental self-diffusion coefficient data. With the determined parameters and the scaling relations, we evaluated shear viscosities of EGO/water binary mixtures, which are in close agreement with the experimental data, without any further fitting procedure. The largest simulation in this article corresponds to a 1.2 microseconds atomistic simulation for 100,000 atoms. Our CG model with the parameterization scheme for CG particles may be useful to study the dynamic properties of a liquid which contains relatively low molecular weight polymers or oligomers...

  5. Viscosities of oxalic acid and its salts in water and binary aqueous mixtures of tetrahydrofuran at different temperatures

    Indian Academy of Sciences (India)

    M L Parmar; M K Guleria

    2005-07-01

    Relative viscosities for the solutions of oxalic acid and its salts, viz. ammonium oxalate, sodium oxalate and potassium oxalate, at different concentrations have been determined in water and in binary aqueous mixtures of tetrahydrofuran (THF) [5, 10, 15 and 20% by weight of THF] at 298.15 K, and in water and in 5% (w/w) THF + water at five different temperatures. The data have been evaluated using the Jones-Dole equation and the obtained parameters have been interpreted in terms of solute-solute and solute-solvent interactions. The activation parameters of viscous flow have been obtained which depicts the mechanism of viscous flow. The oxalic acid and its salts behave as structure breakers in water and in binary aqueous mixtures of THF.

  6. 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......, critical endpoints and three-phase lines for binary mixtures with phase diagrams of types from I to V without advance knowledge of the type of phase diagram. The procedure requires a thermodynamic model in the form of a pressure-explicit EOS but is not specific to a particular equation of state. (C) 2006...... of critical lines. Each calculated point is analysed for stability by means of the tangent plane distance, and the occurrence of an unstable point is used to determine a critical endpoint (CEP). The critical endpoint, in turn, is used as the starting point for constructing the three-phase line. The equations...

  7. Concentration and mass dependence of transport coefficients and correlation functions in binary mixtures with high mass-asymmetry

    OpenAIRE

    W.Fenz; Mryglod, I. M.; Prytula, O.; Folk, R.

    2009-01-01

    Correlation functions and transport coefficients of self-diffusion and shear viscosity of a binary Lennard-Jones mixture with components differing only in their particle mass are studied up to high values of the mass ratio $\\mu$, including the limiting case $\\mu=\\infty$, for different mole fractions $x$. Within a large range of $x$ and $\\mu$ the product of the diffusion coefficient of the heavy species $D_{2}$ and the total shear viscosity of the mixture $\\eta_{m}$ is found to remain constant...

  8. Numerical and analytical solution for the stationary behaviour of binary mixtures in a horizontal annular cavity heated from inside

    Energy Technology Data Exchange (ETDEWEB)

    Marcoux, M. [Universite Paul Sabatier (IMFT), UMR 5502 CNRS/INP/UPS, Groupe GEMP, 31 - Toulouse (France); Desrayaud, G. [Universite de Picardie Jules Verne, LETEM, INSSET, 80 - Amiens (France); Pagano, A.; Fichera, A. [Universita Degli Studi di Catania, DIIM (Italy)

    2005-07-01

    This work is a study of the behavior of a binary mixture filling a horizontal annulus and subjected to a radial thermal gradient, and therefore to thermo-gravitational diffusion. Numerical simulation of this problem has been carried out for a realistic case and gives a precise description of the mixture in the cavity at steady state. From these observations, a complete analytical resolution of the problem is developed. The solution obtained is validated by comparison with numerical results for a wide range of the non-dimensional parameters controlling the problem. Species separation appearing in this case is finally described, bringing out the influence of the geometry. (authors)

  9. Numerical and analytical solution for the stationary behaviour of binary mixtures in a horizontal annular cavity heated from inside

    International Nuclear Information System (INIS)

    This work is a study of the behavior of a binary mixture filling a horizontal annulus and subjected to a radial thermal gradient, and therefore to thermo-gravitational diffusion. Numerical simulation of this problem has been carried out for a realistic case and gives a precise description of the mixture in the cavity at steady state. From these observations, a complete analytical resolution of the problem is developed. The solution obtained is validated by comparison with numerical results for a wide range of the non-dimensional parameters controlling the problem. Species separation appearing in this case is finally described, bringing out the influence of the geometry. (authors)

  10. Volumetric, Ultrasonic and Transport Properties of Binary Liquid Mixtures Containing Dimethyl Formamide at 303.15 K

    Institute of Scientific and Technical Information of China (English)

    SYAMALA,Vardhana; RAJA SEKHAR,Damaramadugu; SIVA KUMAR,Kasibhatta; VENKATESWARLU,Ponneri

    2007-01-01

    Excess volumes (VE), ultrasonic velocities (u), isentropic compressibility (△Ks) and viscosities (η) for the binary mixtures of dimethyl formamide (DMF) with 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,2,4-trichlorobenzene,o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, o-nitrotoluene and m-nitrotoluene at 303.15 K were studied.Excess volume data exhibit an inversion in sign for the mixtures of dimethyl formamide with 1,2- and 1,3-dichlorobenzenes and the property is completely positive over the entire composition range for the mixtures of dimethyl formamide with 1,2,4-trichlorobenzene, o-nitrotoluene and m-nitrotoluene. On the other hand, the quantity is negative for the mixtures of dimethyl formamide with chlorotoluenes. Isentropic compressibility (Ks) has been computed for the same systems from precise sound velocity and density data. Further, deviation of isentropic compressibility (△Ks) from ideal behavior was also calculated. △Ks values are negative over the entire volume fraction range in all the binary mixtures. The experimental sound velocity data were analysed in terms of Free Length Theory (FLT) and Collision Factor Theory (CFT). The viscosity data were analysed on the basis of corresponding state approach. The measured data were discussed on the basis of intermolecular interactions between unlike molecules.

  11. Dynamical dimer structure and liquid structure of fatty acids in their binary liquid mixture: dodecanoic and 3-phenylpropionic acids system.

    Science.gov (United States)

    Iwahashi, Makio; Takebayashi, Shintaro; Umehara, Atsushi; Kasahara, Yasutoshi; Minami, Hideyuki; Matsuzawa, Hideyo; Inoue, Tohru; Takahashi, Hiroshi

    2004-05-01

    Dimer structure and liquid structure of fatty acids in the binary liquid mixture of dodecanoic (LA) and 3-phenylpropionic acids (PPA) were studied through the measurements of DSC, self-diffusion coefficient (D), density, viscosity, 13C NMR spin-lattice relaxation time, small-angle X-ray scattering (SAXS), and small-angle neutron scattering (SANS). The phase diagram of LA/PPA mixture exhibited a typical eutectic pattern, which means that LA and PPA are completely immiscible in solid phase. In the liquid phase of the LA/PPA mixture, D of LA always differed from that of PPA irrespective of their compositions. This exhibited that, in the liquid phase of the binary mixture of fatty acids giving a complete eutectic in the solid phase, the fatty acid dimers are composed of the same fatty acid species irrespective of their compositions. The liquid structure of the LA/PPA mixture was clarified through the SAXS and also the SANS measurements. PMID:15081860

  12. 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

    2015-12-01

    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. PMID:26186613

  13. Accretion and Orbital Inspiral in Gas-Assisted Supermassive Black Hole Binary Mergers

    CERN Document Server

    Rafikov, Roman R

    2016-01-01

    Many galaxies are expected to harbor binary supermassive black holes (SMBHs) in their centers. Their interaction with the surrounding gas results in accretion and exchange of angular momentum via tidal torques, facilitating binary inspiral. Here we explore the non-trivial coupling between these two processes and analyze how the global properties of externally supplied circumbinary disks depend on the binary accretion rate. By formulating our results in terms of the angular momentum flux driven by internal stresses, we come up with a very simple classification of the possible global disk structures, which differ from the standard constant $\\dot M$ accretion disk solution. Suppression of accretion by the binary tides, leading to a significant mass accumulation in the inner disk, accelerates binary inspiral. We show that once the disk region strongly perturbed by the viscously transmitted tidal torque exceeds the binary semi-major axis, the binary can merge in less than its mass-doubling time due to accretion. T...

  14. Localized Waves without the Existence of Extended Waves: Oscillatory Convection of Binary Mixtures with Strong Soret Effect

    OpenAIRE

    Jung, D.; Luecke, M.

    2002-01-01

    Spatially confined solutions of traveling convection rolls are determined numerically for binary mixtures like ethanol-water. The appropriate field equations are solved in a vertical crossection of the rolls perpendicular to their axes subject to realistic horizontal boundary conditions. The localized convective states are stably and robustly sustained by strongly nonlinear mixing and complex flow-induced concentration redistribution. We elucidate how this enables their existence for strongly...

  15. Transport phenomena and microscopic structure in partially miscible binary fluids: A simulation study of the symmetrical Lennard-Jones mixture

    OpenAIRE

    Das, Subir K.; Horbach, Jürgen; Binder, Kurt

    2003-01-01

    Static and dynamic structure factors and various transport coefficients are computed for a Lennard-Jones model of a binary fluid (A,B) with a symmetrical miscibility gap, varying both temperature and relative concentration of the mixture. The model is first equilibrated by a semi-grandcanonical Monte Carlo method, choosing the temperature and chemical potential difference $\\Delta \\mu$ between the two species as the given independent variables. Varying for $\\Delta \\mu=0$ the temperature and pa...

  16. Parametrization of coarse grained force fields for dynamic property of ethylene glycol oligomers/water binary mixtures

    OpenAIRE

    YAMAZAKI, Tamio

    2011-01-01

    To evaluate shear viscosity of ethylene glycol oligomers (EGO)/water binary mixture by means of coarse-grained molecular dynamics (CG-MD) simulations, we proposed the self-diffusion-coefficient-based parameterization of non-bonded interactions among CG particles. Our parameterization procedure consists of three steps: 1) determination of bonded potentials, 2) scaling for time and solvent diffusivity, and 3) optimization of Lennard-Jones parameters to reproduce experimental self-diffusion coef...

  17. Binary, ternary and quaternary liquid-liquid equilibria in 1-butanol, oleic acid, water and n-heptane mixtures

    OpenAIRE

    Winkelman, J.G.M.; Kraai, G. N.; Heeres, H. J.

    2009-01-01

    This work reports on liquid-liquid equilibria in the system 1-butanol, oleic acid, water and n-heptane used for biphasic, lipase catalysed esterifications. The literature was studied on the mutual solubility in binary systems of water and each of the organic components. Experimental results were obtained on the composition of the coexisting phases of a series of ternary and quaternary mixtures of the components at 301,308 and 313 K. The data were correlated successfully with the UNIQUAC model...

  18. Accurate values of some thermodynamic properties for carbon dioxide, ethane, propane, and some binary mixtures.

    Science.gov (United States)

    Velasco, Inmaculada; Rivas, Clara; Martínez-López, José F; Blanco, Sofía T; Otín, Santos; Artal, Manuela

    2011-06-30

    Quasicontinuous PρT data of CO(2), ethane, propane, and the [CO(2) + ethane] mixture have been determined along subcritical, critical, and supercritical regions. These data have been used to develop the optimal experimental method and to determine the precision of the results obtained when using an Anton Paar DMA HPM vibrating-tube densimeter. A comparison with data from reference EoS and other authors confirm the quality of our experimental setup, its calibration, and testing. For pure compounds, the value of the mean relative deviation is MRD(ρ) = 0.05% for the liquid phase and for the extended critical and supercritical region. For binary mixtures the mean relative deviation is MRD(ρ) = 0.70% in the range up to 20 MPa and MRD(ρ) = 0.20% in the range up to 70 MPa. The number of experimental points measured and their just quality have enable us to determine some derivated properties with satisfactory precision; isothermal compressibilities, κ(T), have been calculated for CO(2) and ethane (MRD(κ(T)) = 1.5%), isobaric expasion coefficients, α(P), and internal pressures, π(i), for CO(2) (MRD(α(P)) = 5% and MRD(π(i)) = 7%) and ethane (MRD(α(P)) = 7.5% and MRD(π(i)) = 8%). An in-depth discussion is presented on the behavior of the properties obtained along subcritical, critical, and supercritical regions. In addition, PuT values have been determined for water and compressed ethane from 273.19 to 463.26 K up to pressures of 190.0 MPa, using a device based on a 5 MHz pulsed ultrasonic system (MRD(u) = 0.1%). With these data we have calibrated the apparatus and have verified the adequacy of the operation with normal liquids as well as with some compressed gases. From density and speed of sound data of ethane, isentropic compressibilities, κ(s), have been obtained, and from these and our values for κ(T) and α(P), isobaric heat capacities, C(p), have been calculated with MRD(C(p)) = 3%, wich is within that of the EoS. PMID:21639086

  19. Experimental and computational studies on flow behavior of gas-solid fluidized bed with disparately sized binary particles

    Institute of Scientific and Technical Information of China (English)

    Jinsen Gao; Jian Chang; Chunxi Lu; Chunming Xu

    2008-01-01

    This paper presents experimental and computational studies on the flow behavior of a gas-solid fluidized bed with disparately sized binary particle mixtures. The mixing/segregation behavior and segregation efficiency of the small and large particles are investigated experimentally.Particle composition and operating conditions that influence the fluidization behavior of mixing/segregation are examined. Based on the granular kinetics theory, a multi-fluid CFD model has been developed and verified against the experimental results. The simulation results are in reasonable agreement with experimental data. The results showed that the smaller particles are found near the bed surface while the larger particles tend to settle down to the bed bottom in turbulent fluidized bed. However, complete segregation of the binary particles does not occur in the gas velocity range of 0.695--0.904 m/s. Segregation efficiency increases with increasing gas velocity and mean residence time of the binary particles, but decreases with increasing the small particle concentration. The calculated results also show that the small particles move downward in the wall region and upward in the core. Due to the effect of large particles on the movement of small particles, the small particles present a more turbulent velocity profile in the dense phase than that in the dilute phase.

  20. Self-assembly of mixtures of nanorods in binary, phase-separating blends

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Li-Tang; Maresov, Egor; Buxton, Gavin A.; Balazs, Anna C.

    2010-01-01

    Aligned nanorod inclusions have the potential to significantly improve both the photovoltaic and mechanical properties of polymeric materials. Establishing facile methods for driving or “corralling” the nanorods to self-assemble into such aligned morphologies could facilitate the fabrication of effective, robust devices. Using a variety of computational methods, we model the self-assembly of a mixture of A-coated and B-coated rods in an AB phase-separating blend. Using dissipative particle dynamics (DPD) simulations, we first show that the steric repulsion between ligands causes the coated rods to preferentially align end-to-end within the minority phase of the binary blend. Using this information, we then utilize a coarse-grained approach, which combines a Cahn–Hilliard (CH) model for the polymer blend with a Brownian dynamics (BD) simulation for the rods, to simulate a larger sample of a rod-filled 30:70 AB thin film. We find that just a small volume fraction of B rods in the majority B phase promotes the percolation of A-like rods within A, so that the percolation threshold for the A-rods is significantly lowered. If, however, the number of Bnanorods in the B phase exceeds a particular volume fraction, the B particles inhibit the percolation of the A rods. Thus, there is an optimal volume fraction of Bnanorods that provides the beneficial effects. The output from these morphological studies then serves as the input to the lattice spring model (LSM) for mechanical behavior of the composite. The results reveal that nanorods oriented along the tensile direction contribute to the enhancement of the macroscopic mechanical properties of the material. This multi-scale approach, integrating techniques that cover the microscopic, mesoscopic and macroscopic, provides a valuable means of determining structure–property relationships in nanocomposites and establishing useful guidelines for tailoring the components to yield optimal materials' properties.

  1. Cellular detonation diffraction in gas-particle mixtures

    Science.gov (United States)

    Fedorov, A. V.; Khmel, T. A.; Kratova, Y. V.

    2010-12-01

    Diffraction of cellular heterogeneous detonation out of a channel into open half-space in a mixture of aluminum particles and oxygen is investigated numerically. The flow is found to be very similar to gas detonation diffraction. The detonation weakening behind the step results in combustion front deceleration and decoupling from the leading shock wave. Subsequent re-initiation takes place in a transverse wave. New transverse waves are generated along the expanding front. The computations that were performed show that the critical number of cells is several times less than that for gases. This is confirmed by theoretical estimates based upon the Mitrofanov-Soloukhin approach.

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

    Energy Technology Data Exchange (ETDEWEB)

    Almasi, Mohammad, E-mail: m.almasi@khouzestan.srbiau.ac.ir [Department of Chemistry, Science and Research Branch, Islamic Azad University, Khouzestan (Iran, Islamic Republic of)

    2013-03-01

    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{sub m}{sup E}. were calculated and correlated by the Redlich–Kister equation to obtain the binary coefficients and the standard deviations. Excess molar volumes, V{sub m}{sup 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.

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

    Science.gov (United States)

    Almasi, Mohammad

    2013-03-01

    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, VmE. were calculated and correlated by the Redlich-Kister equation to obtain the binary coefficients and the standard deviations. Excess molar volumes, VmE, 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. Slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures

    Science.gov (United States)

    Aines, Roger D.; Bourcier, William L.; Viani, Brian

    2013-01-29

    A slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures includes the steps of dissolving the gas mixture and carbon dioxide in water providing a gas, carbon dioxide, water mixture; adding a porous solid media to the gas, carbon dioxide, water mixture forming a slurry of gas, carbon dioxide, water, and porous solid media; heating the slurry of gas, carbon dioxide, water, and porous solid media producing steam; and cooling the steam to produce purified water and carbon dioxide.

  5. Smoothed particle hydrodynamics simulations of gas and dust mixtures

    CERN Document Server

    Booth, Richard A; Clarke, Cathie J

    2015-01-01

    We present a 'two-fluid' implementation of dust in smoothed particle hydrodynamics (SPH) in the test particle limit. The scheme is able to handle both short and long stopping times and reproduces the short friction time limit, which is not properly handled in other implementations. We apply novel tests to verify its accuracy and limitations, including multi-dimensional tests that have not been previously applied to the drag-coupled dust problem and which are particularly relevant to self-gravitating protoplanetary discs. Our tests demonstrate several key requirements for accurate simulations of gas-dust mixtures. Firstly, in standard SPH particle jitter can degrade the dust solution, even when the gas density is well reproduced. The use of integral gradients, a Wendland kernel and a large number of neighbours can control this, albeit at a greater computational cost. Secondly, when it is necessary to limit the artificial viscosity we recommend using the Cullen & Dehnen (2010) switch, since the alternative,...

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

    Directory of Open Access Journals (Sweden)

    P. Losada-Pérez

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Homocianu, Mihaela, E-mail: michalupu@yahoo.co.uk; Ipate, Alina Mirela; Hamciuc, Corneliu; Airinei, Anton

    2015-01-15

    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{sub 3}/DMF) and chloroform–dimethyl sulfoxide (CHCl{sub 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. Binary and Tertiary Mixtures of Satureja hortensis and Origanum vulgare Essential Oils as Potent Antimicrobial Agents Against Helicobacter pylori.

    Science.gov (United States)

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

    2016-03-01

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

  9. THE MIXTURES OF 2.4-DINITROPHENYLHIDRAZONES OF INFERIOR CARBONYL COMPOUNDS AND THEIR HPLC SEPARATION WITH GRADIENT BINARY MIXTURES PHASES

    Directory of Open Access Journals (Sweden)

    Gheorghe Zgherea

    2008-06-01

    Full Text Available Mixtures of small quantities of carbonyl compounds are presents in foods, concerning sensorial qualities. The inferior carbonyl compounds (C2-C4, boiling point <100°C – mono and dicarbonyl – can be identified and measured their concentrations, after a separation by distillation on the water bath. They are transferred in a strongly acid solution of 2.4-dinitrophenylhidrazine (2.4-DNPH, generating a mixture of insoluble 2.4-dinitrophenylhidrazones (2.4-DNPH-ones. The 2.4-DNPH-ones are organic compounds with weak polarity, solids, crystallized, yellows and water insoluble, soluble in organic solvents. The mixture of 2.4dinitrophenylhidrazones may be separated by liquid chromatography, using the reverse phase mechanism [1-3]. This paper contains experimental and theoretical considerations to the means of separation through liquid chromatography of two synthetically and a natural mixtures that contain 2.4-DNPH-ones provided by inferior carbonyl compounds; to obtain conclude results, in the synthetically mixtures was introduce and 2.4-DNPH-ones provided by carbonyl compounds having three (acetone and propanal and four (isobutyl aldehyde atoms of carbon.

  10. Studies on intermolecular interaction on binary mixtures of methyl orange-water system: excess molar functions of ultrasonic parameters at different concentrations and at different temperatures.

    Science.gov (United States)

    Thanuja, B; Kanagam, Charles; Sreedevi, S

    2011-11-01

    Density (ρ), viscosity (η) and ultrasonic velocity (u) of binary mixtures of methyl orange and water were measured at different concentrations and at different temperatures; several useful parameters such as excess volume, excess velocity, and excess adiabatic compressibility have been calculated. These parameters are used to explain the nature of intermolecular interactions taking place in the binary mixture. The above study is helpful in understanding the dye/solvent interaction at different concentration and temperatures. PMID:21596612

  11. Chemical Discrimination in Turbulent Gas Mixtures with MOX Sensors Validated by Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Jordi Fonollosa

    2014-10-01

    Full Text Available Chemical detection systems based on chemo-resistive sensors usually include a gas chamber to control the sample air flow and to minimize turbulence. However, such a kind of experimental setup does not reproduce the gas concentration fluctuations observed in natural environments and destroys the spatio-temporal information contained in gas plumes. Aiming at reproducing more realistic environments, we utilize a wind tunnel with two independent gas sources that get naturally mixed along a turbulent flow. For the first time, chemo-resistive gas sensors are exposed to dynamic gas mixtures generated with several concentration levels at the sources. Moreover, the ground truth of gas concentrations at the sensor location was estimated by means of gas chromatography-mass spectrometry. We used a support vector machine as a tool to show that chemo-resistive transduction can be utilized to reliably identify chemical components in dynamic turbulent mixtures, as long as sufficient gas concentration coverage is used. We show that in open sampling systems, training the classifiers only on high concentrations of gases produces less effective classification and that it is important to calibrate the classification method with data at low gas concentrations to achieve optimal performance.

  12. Excess molar volumes and viscosities of binary mixtures of 1,2-diethoxyethane with chloroalkanes at 298 15 K

    Indian Academy of Sciences (India)

    Amalendu Pal; Rakesh Kumar Bhardwaj

    2001-06-01

    Excess molar volumes ($V^{E}_{m}$) and viscosities () of the binary mixtures of 1,2-diethoxyethane with di-, tri- and tetrachloromethane have been measured at 298.15 K and atmospheric pressure over the entire mole fraction range. The deviations in viscosities (ln) and excess energies of activation ( *) for viscous flow have been calculated from the experimental data. The Prigogine-Flory-Patterson (PFP) model has been used to calculate $V^{E}_{m}$, and the results have been compared with experimental data. The Bloomfield and Dewan model has been used to calculate viscosity coefficients and these have also been compared with experimental data for the three mixtures. The results have been discussed in terms of dipole-dipole interactions between 1,2-diethoxyethane and chloroalkanes and their magnitudes decreasing with the dipole character of the molecules. A short comparative study with results for mixtures with polyethers and chloroalkanes is also described.

  13. The component fractionation effect in binary-component gas adsorption isotherm experiments on coal

    Institute of Scientific and Technical Information of China (English)

    TANG Shuheng; HAO Duohu; TANG Dazhen; LIU Dameng

    2005-01-01

    Different gas adsorption isotherm experiments were carried out on the coal samples from Jincheng district,including N2, CH4, CO2, as well as the binary-component gas of CH4-N2 and CH4-CO2 of three different concentrations. In the binary-component gas adsorption isotherm experiments,the gas component with higher adsorption ability is adsorbed firstly. Thus the result in its relative concentration in the free phase shows a trend of decrease first and then increase,whereas the relative concentration of the gas component with lower adsorption ability shows a trend of increase first and then decrease. In the adsorption phrase, the relative concentration of the gas component with higher adsorption ability increases gradually, and the relative concentration of the gas component with lower adsorption ability decreases gradually.In the adsorption competition of the binary-component gas,the adsorption rate of the gas component with higher adsorption ability shows a trend of rapidity at first then slowness, but the adsorption rate of the gas component with lower adsorption ability shows a trend of slowness at first then rapidity. The component fractionation effect in the binary-component gas adsorption isotherm experiments is caused by the difference of the adsorption ability of coal of different gas components.

  14. Centrifugal pumping of gas-liquid mixtures: a mechanistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Estevam, Valdir [PETROBRAS, Rio de Janeiro, RJ (Brazil); Franca, Fernando A. [Universidade Estadual de Campinas, SP (Brazil); Alhanati, Francisco J.S. [C-Fer Technologies, Edmonton, Alberta (Canada)

    2004-07-01

    Centrifugal pumps are known to show a 'surging' behavior at certain conditions of free gas and liquid flow rate at the intake. In the 'surging region' on a pump characteristic curve, the head generated is significantly lower than if the pump were handling a gas-liquid homogeneous mixture. The surging happens, as one shows in this paper, due to the existence of a gas pocket, referred as 'elongated bubble', at the pump impeller inlet region. Therefore, to be able to predict the performance of centrifugal pumps under two-phase conditions, one has to disclose and model the mechanisms that set existence of the elongated bubble at the impeller inlet, besides calculating its length inside the impeller. This paper reports on the results of experimental and mechanistic modelling work conducted with the objective of better predicting the gas-liquid performance of centrifugal pumps under all range of conditions, including those characterized by 'surging'. The focus was on small diameter centrifugal pumps used to produce oil wells. A mechanistic two-fluid model devised to calculate the head generated by the pump was developed. The predictions of the model show good agreement with data collected for this study, and with data recently collected by other research organizations. (author)

  15. The interaction effects of binary mixtures of benzene and toluene on the developing heart of medaka (Oryzias latipes).

    Science.gov (United States)

    Teuschler, Linda K; Gennings, Chris; Hartley, William R; Carter, Hans; Thiyagarajah, Arunthavarani; Schoeny, Rita; Cubbison, Chris

    2005-03-01

    The United States Environmental Protection Agency (USEPA) has pursued the estimation of risk of adverse health effects from exposure to chemical mixtures since the early 1980s. Methods used to calculate risk estimates of mixtures were often based on single chemical information that required assumptions of dose-addition or response-addition and did not consider possible changes in response due to interaction effects among chemicals. Full factorial designs for laboratory studies can produce interactions information, but these are expensive to perform and may not provide the information needed to evaluate specific environmentally relevant mixtures. In this research, groups of Japanese medaka (Oryzias latipes) embryos were exposed to binary mixtures of benzene and toluene as well as to each of these chemicals alone. Endpoint specific dose-response models were built for the hydrocarbon mixture under an assumption of dose-additivity, using the single chemical dose-response information on benzene and toluene. The endpoints included heart rate, heart rate progression, and lethality. Results included a synergistic response for heart rate at 72 h of development, and either additivity or antagonism for all other endpoints at 96 h of development. This work uses an established statistical method to evaluate the toxicity of an environmentally relevant mixture to ascertain whether interaction effects are occurring, thus providing additional information on toxicity. PMID:15667848

  16. Relaxation rate of the shape fluctuation of a fluid membrane immersed in a near-critical binary fluid mixture.

    Science.gov (United States)

    Fujitani, Youhei

    2016-03-01

    We consider the two-time correlation of the shape fluctuation of a fluid membrane immersed in a near-critical binary fluid mixture. Usually one component of the mixture is preferably attracted by the membrane. Adsorption layers, where the preferred component is more concentrated, are generated on both sides of the membrane significantly because of the near-criticality. The resultant gradient of the local mass-density difference between the two components generates additional stress, including the osmotic pressure, to influence the membrane motion. Assuming the mixture to be in the homogeneous phase near, but not too close to, the demixing critical point, we use the Gaussian free-energy functional to calculate the relaxation rate for a wavelength much longer than the correlation length of the mixture. Our calculation supposes weak preferential attraction and weak dependence of the mixture viscosity on the mass-density difference, and is performed within the linear approximation with respect to the undulation amplitude. It is shown for small wave number that the additional stress makes the relaxation more rapid independently of whether the preferred component is more viscous or not and that the relaxation rate can be regarded as proportional to the wave number even for a tensionless membrane. This linear dependence comes from the balance between the frictional force due to the mixture viscosity and the restoring force of the adsorption layer. PMID:26993992

  17. Separate spectrophotometric determination of gadolinium and dysprosium in binary mixtures by phthalexones using nomogram

    International Nuclear Information System (INIS)

    The possibility has been shown of using different-ligand complexes of rare earths with phthalexones and cetylpyridinium for differential spectrophotometric determination of rare earths in mixtures. The molar absorptivities of individual components of a mixture are not constant values if the total mixture concentration changes. The application of an equation for calculation of mixture absorbances makes it possible to change concentration of the components in mixtures over a wide range (the limit Me1:Me2 ratio is 1:50). Simultaneous nomographic determinations of gadolinium and dysprosium in their mixtures were carried out

  18. Segregation phases in a vibrated binary granular layer

    OpenAIRE

    Reis, P. M.; Ehrhardt, G.; Mullin, T.

    2003-01-01

    We present the results of an experimental study of patterned segregation in a horizontally shaken shallow layer of a binary mixture of dry particles. As the compacity, $C$, of the mixture was increased, the evolution of three distinct phases was observed. We classify them as binary gas, segregation liquid and segregation crystal phases using macroscopic and microscopic measures. The binary gas to segregation liquid transition is consistent with a continuous phase transition and includes the c...

  19. 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. PMID:22252547

  20. 10 CFR 503.38 - Permanent exemption for certain fuel mixtures containing natural gas or petroleum.

    Science.gov (United States)

    2010-01-01

    ... natural gas or petroleum. 503.38 Section 503.38 Energy DEPARTMENT OF ENERGY (CONTINUED) ALTERNATE FUELS... mixtures containing natural gas or petroleum. (a) Eligibility. Section 212(d) of the Act provides for a... proposes to use a mixture of natural gas or petroleum and an alternate fuel as a primary energy source;...

  1. Observation of vapor bubble of non-azeotropic binary mixture in microgravity with a two-wavelength interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Yoshiyuki; Iwasaki, Akira

    1999-07-01

    Although non-azeotropic mixtures are considered to be promising working fluids in advanced energy conversion systems, the primary technical problems in the heat transfer degradation in phase change processes cause economical handicap to wide-spread applications. The boiling behavior of mixtures still remains a number of basic questions being not answered yet, and the present authors believe that the most essential information for the boiling process in non-azeotropic mixtures is how temperature and concentration profiles are developed around the bubbles. The present study attempts at understanding fundamental heat and mass transfer mechanisms in nucleate pool boiling of non-azeotropic binary mixtures, and with the knowledge to develop a passive boiling heat transfer enhancement eventually. To this end, the authors have employed microgravity environment for rather detailed observation around vapor bubbles in the course of boiling inception and bubble growth. A two-wavelength Mach-Zehnder interferometer has been developed, which withstands mechanical shock caused by gravity change from very low gravity of the order of 10{sup {minus}5} g to relatively high gravity of approximately 8 g exposed during deceleration period. A series of experiments on single vapor bubbles for CFC113 single component and CFC12/CFC112 non-azeotropic binary mixture have been conducted under a high quality microgravity conditions available in 10-second free-fall facility of Japan Microgravity Center (JAMIC). The results for single component liquid showed a strong influence due to Marangoni effect caused by the temperature profile around the bubble. The results for non-azeotropic binary mixture showed, however, considerably different behavior from single component liquid. Both temperature and concentration profiles around a single vapor bubble were evaluated from the interferograms. The temperature and concentration layers established around the bubbles were nearly one order of magnitude larger

  2. Photoinduced toxicity single and binary mixtures of four polycyclic aromatic hydrocarbons to the marine diatom Skeletonema costatum

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Diatom Skeletonema costatum Cleve is one of the main predominant phytoplankton species in the Changjiang Estuary in China. In order to provide some basic information for future assessment of the potential risk on phytoplankton communities in this estuary caused by polycyclic aromatic hydrocarbons(PAHs), this alga was selected as a representative to investigate the photoinduced toxicity of PAHs, in single and mixture. Four PAHs including three-ring phenanthrene and anthracene, four-ring fluoranthene and pyrene were tested in the laboratory. The single toxicity of each PAH on this microalga was compared with and without the simulated solar UV radiation. The results showed that this microalga was sensitive to PAH's photoinduced toxicity. Ratios of the 72 h median effect concentration obtained for fluorescent and UV light tests were about 8.4 for phenanthrene, 13.0 for anthracene, 6.5 for fluoranthene, and 5.7 for pyrene, indicating that UV light enhanced the PAH toxicity to this alga significantly. Under the fluorescent radiation (lacking UV), the dose-response curves based on chemical concentrations revealed that the order of toxic strength was fluoranthene greater than pyrene greater than anthracene greater than phenanthrene; while under the UV radiation (476 μW/cm2 for UVA, 6.5 μW/cm2 for UVB) it became fluoranthene approximately equaling anthracene greater than pyrene greater than phenanthrene, indicating that the UV light also changed its relative toxicity to this alga. The photoinduced toxicity of PAHs to the marine diatom S. costatum might be a synergistic effect of photosensitization reactions (e.g., generation of single-state oxygen) and photomodification (photooxidation and/or photolysis).The combined effects of six binary mixtures on the marine diatom S. costatum were investigated using the additive-index method. Four binary-mixtures (phenanthrene plus anthracene; phenanthrene plus pyrene; anthracene plus fluoranthene; anthracene plus pyrene) were found

  3. The kinetic theory of partially ionized reactive gas mixtures II

    Energy Technology Data Exchange (ETDEWEB)

    Giovangigli, Vincent; Graille, Benjamin [CMAP, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)], E-mail: vincent.giovangigli@polytechnique.fr

    2009-01-16

    We investigate the kinetic theory of partially ionized reactive gas mixtures in strong magnetic fields following Giovangigli et al (2003 Physica A 327 313-48). A new tensor basis is introduced for expanding the perturbed distribution functions associated with the viscous tensor. New symmetry properties of transport coefficients are established as well as simplified bracket expressions. A variational framework is introduced for a direct evaluation of the thermal conductivity and the thermal diffusion ratios. The transport linear systems corresponding to the usual Sonine/Wang-Chang Uhlenbeck polynomial expansions are evaluated. The behavior of transport coefficients and transport fluxes for vanishing magnetic fields is investigated using series expansions. Practical implementation of iterative algorithms for solving the resulting complex symmetric constrained singular linear systems is discussed as well as various approximations of the transport coefficients.

  4. Smoothed particle hydrodynamics simulations of gas and dust mixtures

    Science.gov (United States)

    Booth, R. A.; Sijacki, D.; Clarke, C. J.

    2015-10-01

    We present a `two-fluid' implementation of dust in smoothed particle hydrodynamics (SPH) in the test particle limit. The scheme is able to handle both short and long stopping times and reproduces the short friction time limit, which is not properly handled in other implementations. We apply novel tests to verify its accuracy and limitations, including multidimensional tests that have not been previously applied to the drag-coupled dust problem and which are particularly relevant to self-gravitating protoplanetary discs. Our tests demonstrate several key requirements for accurate simulations of gas-dust mixtures. First, in standard SPH particle jitter can degrade the dust solution, even when the gas density is well reproduced. The use of integral gradients, a Wendland kernel and a large number of neighbours can control this, albeit at a greater computational cost. Secondly, when it is necessary to limit the artificial viscosity we recommend using the Cullen & Dehnen switch, since the alternative, using α ˜ 0.1, can generate a large velocity noise up to σv ≲ 0.3cs in the dust particles. Thirdly, we find that an accurate dust density estimate requires >400 neighbours, since, unlike the gas, the dust particles do not feel regularization forces. This density noise applies to all particle-based two-fluid implementations of dust, irrespective of the hydro solver and could lead to numerically induced fragmentation. Although our tests show accurate dusty gas simulations are possible, care must be taken to minimize the contribution from numerical noise.

  5. 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.

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

    Science.gov (United States)

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

    2012-06-01

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

  7. A molecular-based approach to the thermodynamics of aqueous solutions: binary mixture of water and carbon dioxide

    International Nuclear Information System (INIS)

    A simple model and theory of molecular fluids is applied to a binary mixture of water and carbon dioxide. An approach based on the perturbation theory is followed using a reference system of so-called pseudo-hard bodies for water and hard triatomics for carbon dioxide. Pseudo-hard bodies bear the traits of the non-additive nature of association supplementing the common excluded volume effect. The reference term is parametrized using Monte Carlo simulation data on the compressibility factor. After adding a simple mean-field term to the reference equation, fluid phase equilibria are qualitatively reproduced. (paper)

  8. Mode-coupling theory of the stress-tensor autocorrelation function of a dense binary fluid mixture

    OpenAIRE

    Sinha, Supurna; Marchetti, M. Cristina

    2005-01-01

    We present a generalized mode-coupling theory for a dense binary fluid mixture. The theory is used to calculate molecular-scale renormalizations to the stress-tensor autocorrelation function (STAF) and to the long-wavelength zero-frequency shear viscosity. As in the case of a dense simple fluid, we find that the STAF appears to decay as $t^{-3/2}$ over an intermediate range of time. The coefficient of this long-time tail is more than two orders of magnitude larger than that obtained from conv...

  9. Evaluation of Excess Thermodynamic Parameters in a Binary Liquid Mixture (Cyclohexane + O-Xylene) at Different Temperatures

    OpenAIRE

    K. Narendra; Narayanamurthy, P.; CH. Srinivasu

    2010-01-01

    The ultrasonic velocity, density and viscosity in binary liquid mixture cyclohexane with o-xylene have been determined at different temperatures from 303.15 to 318.15 K over the whole composition range. The data have been utilized to estimate the excess adiabatic compressibility (βE), excess volumes (VE), excess intermolecular free length (LfE), excess internal pressure (πE) and excess enthalpy (HE) at the above temperatures. The excess values have been found to be useful in estimating the st...

  10. 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).

  11. Densities, Ultrasonic Speeds, Viscosities and Refractive Indices of Binary Mixtures of Benzene with Benzyl Alcohol,Benzonitrile, Benzoyl Chloride and Chlorobenzene at 303.15 K

    Institute of Scientific and Technical Information of China (English)

    ALI,A.; PANDEY,J.D.; SONI,N.K.; NAIN,A.K.; LAL,B.; CHAND,D.

    2005-01-01

    Densities, p, ultrasonic speeds, u, viscosities, η, and refractive indices, n, of pure benzene, benzyl alcohol (BA),benzonitrile (BN), benzoyl chloride (BC), chlorobenzene (CB) and their thirty six binary mixtures, with benzene as common component, were measured at 303.15 K over the entire mole fraction range. From these experimental data the values of deviations in ultrasonic speed, Au, isentropic compressibility, Δks, excess acoustic impedance, ZE, deviation in viscosity, Δη, and excess Gibbs free energy of activation of viscous flow, G*E, and partial molar isentropic compressibility, Kφ,2 of BA, BN, BC and CB in benzene were computed. The variation of these derived functions with composition of the mixtures suggested the increased cohesion (molecular order) in the solution and that interaction (A-B)>(A-A) or (B-B). Moreover, theoretical prediction of ultrasonic speed, viscosity and refractive index of all the four binary mixtures was made on the basis of empirical and semi-empirical relations by using the experimental values of the pure components. Comparison of theoretical results with the experimental values was made in order to assess the suitability of these relations in reproducing the experimental values of u, η and n. Also, molecular radii of pure liquids and the average molecular radii of binary mixtures were evaluated using the corresponding refractive indices of pure liquids and binary mixtures. The average molecular radii of binary mixtures were found to be additive with respect to mole fraction of the pure component.

  12. An Analytic Equation of State Based on SAFT-CP for Binary Non-Polar Alkane Mixtures Across the Critical Point

    Institute of Scientific and Technical Information of China (English)

    周文来; 密建国; 贺刚; 于燕梅; 陈健

    2003-01-01

    The description using an analytic equation of state of thermodynamic properties near the critical points of fluids and their mixtures remains a challenging problem in the area of chemical engineering. Based on the statistical associating fluid theory across the critical point (SAFT-CP), an analytic equation of state is established in this work for non-polar mixtures. With two binary parameters, this equation of state can be used to calculate not only vapor-liquid equilibria but also critical properties of binary non-polar alkane mixtures with acceptable deviations.

  13. Volumetric, viscometric and optical study of molecular interactions in binary mixtures of diethyl malonate with ketones at 303.15, 308.15 and 313.15K

    Directory of Open Access Journals (Sweden)

    Rathnam Manapragada V.

    2012-01-01

    Full Text Available Density ρ, viscosity η, and refractive index nD were measured for the binary mixtures of diethyl malonate with ketones (acetophenone, cyclopentanone, cyclohexanone and 3-pentanone at temperatures (303.15, 308.15 and 313.15 K over the entire composition range. Excess volume VE, deviation in viscosity Δη, excess Gibb’s free energy of activation for viscous flow ΔGE and deviation in molar refraction ÄR were determined from the experimental data and computed results were fitted to the Redlich-Kister polynomial equation. The values of VE, Δη, ΔGE, and ΔR were plotted against the mole fraction of diethyl malonate. The observed positive and negative values of excess parameters for all the studied binary mixtures were explained on the basis of intermolecular interactions present in these mixtures. Further different empirical relations were used to correlate the binary mixture viscosities and refractive indices.

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

    Science.gov (United States)

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

    2015-04-01

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

  15. Concentration and mass dependence of transport coefficients and correlation functions in binary mixtures with high mass asymmetry.

    Science.gov (United States)

    Fenz, W; Mryglod, I M; Prytula, O; Folk, R

    2009-08-01

    Correlation functions and transport coefficients of self-diffusion and shear viscosity of a binary Lennard-Jones mixture with components differing only in their particle mass are studied up to high values of the mass ratio mu, including the limiting case mu = infinity, for different mole fractions x. Within a large range of x and mu the product of the diffusion coefficient of the heavy species D(2) and the total shear viscosity of the mixture eta(m) is found to remain constant, obeying a generalized Stokes-Einstein relation. At high liquid density, large mass ratios lead to a pronounced cage effect that is observable in the mean square displacement, the velocity autocorrelation function, and the van Hove correlation function. PMID:19792112

  16. Densities, Viscosities, Sound Speeds, Refractive Indices, and Excess Properties of Binary Mixtures of Isoamyl Alcohol with Some Alkoxyethanols

    Science.gov (United States)

    Roy, Mahendra Nath; Sah, Radhey Shyam; Pradhan, Prasanna

    2010-02-01

    Densities and viscosities were measured for binary mixtures of isoamyl alcohol with 2-methoxyethanol, 2-ethoxyethanol, and 2-butoxyethanol over the entire range of composition at 303.15 K, 313.15 K, and 323.15K and ultrasonic speeds and refractive indices at 303.15 K under atmospheric pressure. From the experimental values of density, viscosity, ultrasonic speed, and refractive index, the values of excess molar volume ( V E), viscosity deviations (Δ η), deviations in isentropic compressibility (Δ K S ), and excess molar refraction (Δ R) have been calculated. The excess or deviation properties were found to be either negative or positive, depending on the molecular interactions and the nature of liquid mixtures.

  17. Concentration and mass dependence of transport coefficients and correlation functions in binary mixtures with high mass asymmetry

    Science.gov (United States)

    Fenz, W.; Mryglod, I. M.; Prytula, O.; Folk, R.

    2009-08-01

    Correlation functions and transport coefficients of self-diffusion and shear viscosity of a binary Lennard-Jones mixture with components differing only in their particle mass are studied up to high values of the mass ratio μ , including the limiting case μ=∞ , for different mole fractions x . Within a large range of x and μ the product of the diffusion coefficient of the heavy species D2 and the total shear viscosity of the mixture ηm is found to remain constant, obeying a generalized Stokes-Einstein relation. At high liquid density, large mass ratios lead to a pronounced cage effect that is observable in the mean square displacement, the velocity autocorrelation function, and the van Hove correlation function.

  18. 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...... that their composition is not fixed, but rather determined by a set of internal degeneracies assigned to the differently sized hard disks, where the larger disks have the higher degeneracies. Such systems are models of monolayers of molecules with internal degrees of freedom. The combined set of translational...... 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-water...

  19. Thermoacoustical and Excess Properties of Binary Mixtures of Ethyl Butyrate with Methanol and Vinyl Acetate

    Directory of Open Access Journals (Sweden)

    Jagdish Prasad Shukla

    2010-06-01

    Full Text Available This paper aims to portray the nature of interaction present in the mixture of ethyl butyrate with methanol and vinyl acetate by computing various thermodynamic parameters at 298.15 K. Excess thermodynamic properties correlated with Redlich–Kister polynomial equation reveals the extent of interaction present in the mixture. Acoustical relations giving the molecular radii of liquid mixtures suggest the change in structure with composition quite well. A comparative study of various empirical and semi-empirical relations such as Flory’s Statistical Theory, Goldsack and Sarvas, Sanchez theory etc. for predicting ultrasonic velocity of the mixtures with the experimental values have been done.

  20. Numerical simulation for explosion wave propagation of combustible mixture gas

    Institute of Scientific and Technical Information of China (English)

    WANG Cheng; NING Jian-guo; MA Tian-bao

    2008-01-01

    A two-dimensional multi-material code was indigenously developed to investigate the effects of duct boundary conditions and ignition positions on the propagation law of explosion wave for hydrogen and methane-based combustible mixture gas. In the code, Young's technique was employed to track the interface between the explosion products and air, and combustible function model was adopted to simulate ignition process. The code was employed to study explosion flow field inside and outside the duct and to obtain peak pressures in different boundary conditions and ignition positions. Numerical results suggest that during the propagation in a duct, for point initiation, the curvature of spherical wave front gradually decreases and evolves into plane wave. Due to the multiple reflections on the duct wall, multi-peak values appear on pressure-time curve, and peak pressure strongly relies on the duct boundary conditions and ignition position. When explosive wave reaches the exit of the duct, explosion products expand outward and forms shock wave in air. Multiple rarefaction waves also occur and propagate upstream along the duct to decrease the pressure in the duct. The results are in agreement with one-dimensional isentropic gas flow theory of the explosion products, and indicate that the ignition model and multi-material interface treatment method are feasible.

  1. APPLICATION OF GAS DYNAMICAL FRICTION FOR PLANETESIMALS. II. EVOLUTION OF BINARY PLANETESIMALS

    Energy Technology Data Exchange (ETDEWEB)

    Grishin, Evgeni; Perets, Hagai B. [Physics Department, Technion—Israel Institute of Technology, Haifa, 3200003 (Israel)

    2016-04-01

    One of the first stages of planet formation is the growth of small planetesimals and their accumulation into large planetesimals and planetary embryos. This early stage occurs long before the dispersal of most of the gas from the protoplanetary disk. At this stage gas–planetesimal interactions play a key role in the dynamical evolution of single intermediate-mass planetesimals (m{sub p} ∼ 10{sup 21}–10{sup 25} g) through gas dynamical friction (GDF). A significant fraction of all solar system planetesimals (asteroids and Kuiper-belt objects) are known to be binary planetesimals (BPs). Here, we explore the effects of GDF on the evolution of BPs embedded in a gaseous disk using an N-body code with a fiducial external force accounting for GDF. We find that GDF can induce binary mergers on timescales shorter than the disk lifetime for masses above m{sub p} ≳ 10{sup 22} g at 1 au, independent of the binary initial separation and eccentricity. Such mergers can affect the structure of merger-formed planetesimals, and the GDF-induced binary inspiral can play a role in the evolution of the planetesimal disk. In addition, binaries on eccentric orbits around the star may evolve in the supersonic regime, where the torque reverses and the binary expands, which would enhance the cross section for planetesimal encounters with the binary. Highly inclined binaries with small mass ratios, evolve due to the combined effects of Kozai–Lidov (KL) cycles with GDF which lead to chaotic evolution. Prograde binaries go through semi-regular KL evolution, while retrograde binaries frequently flip their inclination and ∼50% of them are destroyed.

  2. Accretion and Orbital Inspiral in Gas-assisted Supermassive Black Hole Binary Mergers

    Science.gov (United States)

    Rafikov, Roman R.

    2016-08-01

    Many galaxies are expected to harbor binary supermassive black holes (SMBHs) in their centers. Their interaction with the surrounding gas results in the accretion and exchange of angular momentum via tidal torques, facilitating binary inspiral. Here, we explore the non-trivial coupling between these two processes and analyze how the global properties of externally supplied circumbinary disks depend on the binary accretion rate. By formulating our results in terms of the angular momentum flux driven by internal stresses, we come up with a very simple classification of the possible global disk structures, which differ from the standard constant \\dot{M} accretion disk solution. The suppression of accretion by the binary tides, leading to a significant mass accumulation in the inner disk, accelerates binary inspiral. We show that once the disk region strongly perturbed by the viscously transmitted tidal torque exceeds the binary semimajor axis, the binary can merge in less than its mass-doubling time due to accretion. Thus, unlike the inspirals driven by stellar scattering, the gas-assisted merger can occur even if the binary is embedded in a relatively low-mass disk (lower than its own mass). This is important for resolving the “last parsec” problem for SMBH binaries and understanding powerful gravitational wave sources in the universe. We argue that the enhancement of accretion by the binary found in some recent simulations cannot persist for a long time and should not affect the long-term orbital inspiral. We also review existing simulations of SMBH binary–disk coupling and propose a numerical setup which is particularly well suited to verifying our theoretical predictions.

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

    International Nuclear Information System (INIS)

    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

  4. Formation of H2-He Substellar Bodies in Cold Conditions: Gravitational Stability of Binary Mixtures in a Phase Transition

    CERN Document Server

    Füglistaler, Andreas

    2015-01-01

    Molecular clouds consist typically of 3/4 H2, 1/4 He and traces of heavier elements. In an earlier work we showed that at very low temperatures and high densities, H2 can be in a phase transition leading to the formation of ice clumps as large as comets, or even planets. However, He has very different chemical properties and no phase transition is expected before H2 in dense ISM conditions. The gravitational stability of fluid mixtures has been studied before, but not including a phase transition. We study the gravitational stability of binary fluid mixtures with special emphasis if one component is in a phase transition. The results are aimed at applications in molecular cloud conditions. We study the gravitational stability of van der Waals fluid mixtures using linearised analysis and examine virial equilibrium conditions using the Lennard-Jones inter-molecular potential. Then, combining the Lennard-Jones and gravitational potentials, the non-linear dynamics of fluid mixtures are studied using the molecular...

  5. A methodology to relate octane numbers of binary and ternary n-heptane, iso-octane and toluene mixtures with simulated ignition delay times

    KAUST Repository

    Badra, Jihad A.

    2015-08-11

    Predicting octane numbers (ON) of gasoline surrogate mixtures is of significant importance to the optimization and development of internal combustion (IC) engines. Most ON predictive tools utilize blending rules wherein measured octane numbers are fitted using linear or non-linear mixture fractions on a volumetric or molar basis. In this work, the octane numbers of various binary and ternary n-heptane/iso-octane/toluene blends, referred to as toluene primary reference fuel (TPRF) mixtures, are correlated with a fundamental chemical kinetic parameter, specifically, homogeneous gas-phase fuel/air ignition delay time. Ignition delay times for stoichiometric fuel/air mixtures are calculated at various constant volume conditions (835 K and 20 atm, 825 K and 25 atm, 850 K and 50 atm (research octane number RON-like) and 980 K and 45 atm (motor octane number MON-like)), and for variable volume profiles calculated from cooperative fuel research (CFR) engine pressure and temperature simulations. Compression ratio (or ON) dependent variable volume profile ignition delay times are investigated as well. The constant volume RON-like ignition delay times correlation with RON was the best amongst the other studied conditions. The variable volume ignition delay times condition correlates better with MON than the ignition delay times at the other tested conditions. The best correlation is achieved when using compression ratio dependent variable volume profiles to calculate the ignition delay times. Most of the predicted research octane numbers (RON) have uncertainties that are lower than the repeatability and reproducibility limits of the measurements. Motor octane number (MON) correlation generally has larger uncertainties than that of RON.

  6. The two-dimensional alternative binary L-J system: liquid-gas phase diagram

    Institute of Scientific and Technical Information of China (English)

    张陟; 陈立溁

    2003-01-01

    A two-dimensional (2D) binary system without considering the Lennard-Jones (L-J) potential has been studied by using the Collins model. In this paper, we introduce the L-J potential into the 2D binary system and consider the existence of the holes that are called the "molecular fraction". The liquid-gas phase diagram of the 2D alternative binary L-J system is obtained. The results are quite analogous to the behaviour of 3D substances.

  7. Temperature and vibrational distribution function in high-pressure diatomic gas mixture

    Science.gov (United States)

    Lou, Guofeng; Lempert, Walter R; Adamovich, Igor V; Rich, William J

    2009-03-01

    Temperatures and vibrational populations are investigated experimentally and numerically in a CO-N2-O2 gas mixture. By spatially resolved Raman Q-branch spectra measurement, the strong vibrational excitation was observed in the gas mixtures at a high gas pressure. Numerical calculation, which incorporates both major processes of molecular energy transfer and diffusion of vibrationally excited species across the spatially nonuniform excitation region, provides indepth perception of vibrational kinetics of these diatomic molecular gas mixtures and is verified by the experimental data. The results demonstrate that strong vibrational nonequilibrium for all diatomic species can be sustained by the optical pumping method with a focused CO laser in a relatively cold (300-400 K) molecular gas mixture up to one atmospheric pressure. However, the results also demand further investigations on determining accurate rates of the V-V exchange gas mixture such as for N2-O2.

  8. Critical concentration fluctuations of the ionic binary mixture ethylammonium nitrate-n-octanol: an ultrasonic spectrometry study.

    Science.gov (United States)

    Mirzaev, S Z; Kaatze, U

    2002-02-01

    Between 200 kHz and 130 MHz, the ultrasonic attenuation spectrum of the ionic ethylammonium nitrate--n-octanol mixture of critical composition has been measured at various reduced temperatures (1.5 x 10(-4)viscosity and heat capacity data from the literature, the experimental spectra have been evaluated to yield the scaling function, with the background contribution to the spectra as the only adjustable parameter. Agreement, within the limits of experimental error, of the measured scaling function with that of the nonionic binary system ethanol--dodecane and with the theoretical predictions of the Bhattacharjee-Ferrell dynamic scaling model is found. The amplitude of the fluctuation correlation length xi(o) (=0.47 nm) and the amount of the coupling constant /g/ (=1.3) are rather high as compared to nonionic binary critical mixtures. The amplitude of the relaxation rate of order parameter fluctuations Gamma(o)(=2.6 x 10(8) s(-1)) exhibits an unusual small value, likely to the most part a reflection of the high viscosity and thus small diffusion coefficient of the ionic liquid. PMID:11863532

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

    Directory of Open Access Journals (Sweden)

    František Buňka

    2013-07-01

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

  10. 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

  11. Activity of binary mixtures of drospirenone with progesterone and 17α-ethinylestradiol in vitro and in vivo.

    Science.gov (United States)

    Rossier, Nadine Madeleine; Chew, Geraldine; Zhang, Kun; Riva, Francesco; Fent, Karl

    2016-05-01

    Despite potential exposure of aquatic organisms to mixtures of steroid hormones, very little is known on their joint activity in fish. Drospirenone (DRS) is a new synthetic progestin used in contraceptive pills in combination with 17α-ethinylestradiol (EE2). Here we systematically analyzed effects of DRS in binary mixtures with progesterone (P4) and EE2. First, we determined the in vitro activity of single compounds in recombinant yeast assays that express the human progesterone, androgen, or estrogen receptor, followed by determination of mixture activities of DRS and P4, DRS and EE2, as well as medroxyprogesterone acetate (MPA) and dydrogesterone (DDG). Mixtures of DRS and P4, as well as of DRS and EE2 showed additive progestogenic and androgenic activities. However, DDG and MPA showed non-additive progestogenic and androgenic activities. We then analyzed the in vivo activity of single compounds and mixtures of DRS and P4, as well as DRS and EE2, by assessing transcriptional changes of up to 14 selected target genes in zebrafish embryos at 48h post fertilization (hpf), and in eleuthero-embryos at 96hpf and 144hpf. DRS, P4, and EE2 led to significant transcriptional alteration of genes, including those encoding hormone receptors (pgr, esr1), a steroidogenic enzyme (hsd17b3), and estrogenic markers (vtg1, cyp19b), in particular at 144 hpf. In general, DRS showed stronger transcriptional changes than P4. In mixtures of DRS and P4, they were mainly non-additive (antagonistic interaction). In mixtures of DRS and EE2, transcriptional responses of esr1, vtg1 and cyp19b were dominated by EE2, suggesting an antagonistic interaction or independent action. Equi-effective mixtures of DRS and EE2, based on progesterone receptor transcripts, showed antagonistic interactions. Our data suggest that interactions in mixtures assessed in vitro in recombinant yeast cannot be translated to the in vivo situation. The receptor-based responses did not correspond well to the

  12. Density and surface tension of pure ionic liquid 1-butyl-3-methyl-imidazolium L-lactate and its binary mixture with alcohol and water

    International Nuclear Information System (INIS)

    Highlights: • Density and surface tension of [bmim][L-lactate] and its mixtures with alcohol/water were measured. • Physicochemical properties of pure ionic liquid and its mixtures were discussed. • The excess properties of [bmim][L-lactate] + alcohol show some differences with those of [bmim][L-lactate] + water. -- Abstract: The density and surface tension of the pure ionic liquid 1-butyl-3-methyl-imidazolium L-lactate were measured from T (293.15 to 343.15) K. The coefficient of thermal expansion, molecular volume, standard entropy, lattice energy, surface entropy, surface enthalpy, and enthalpy of vaporization were calculated from the experimental values. Density and surface tension were also determined for binary mixtures of {1-butyl-3-methyl-imidazolium L-lactate + water/alcohol (methanol, ethanol, and 1-butanol)} systems over the whole composition range from T (298.15 to 318.15) K at atmospheric pressure. The partial molar volume, excess partial molar volume and apparent molar volume of the component IL and alcohol/water in the binary mixtures were discussed as well as limiting properties at infinite dilution and the thermal expansion coefficients of the four binary mixtures. The surface properties of the four binary mixtures were also discussed

  13. Catalyst functionalized buffer sorbent pebbles for rapid separation of carbon dioxide from gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Aines, Roger D

    2015-03-31

    A method for separating CO.sub.2 from gas mixtures uses a slurried media impregnated with buffer compounds and coating the solid media with a catalyst or enzyme that promotes the transformation of CO.sub.2 to carbonic acid. Buffer sorbent pebbles with a catalyst or enzyme coating are provided for rapid separation of CO.sub.2 from gas mixtures.

  14. Catalyst functionalized buffer sorbent pebbles for rapid separation of carbon dioxide from gas mixtures

    Science.gov (United States)

    Aines, Roger D.

    2013-03-12

    A method for separating CO.sub.2 from gas mixtures uses a slurried media impregnated with buffer compounds and coating the solid media with a catalyst or enzyme that promotes the transformation of CO.sub.2 to carbonic acid. Buffer sorbent pebbles with a catalyst or enzyme coating are provided for rapid separation of CO.sub.2 from gas mixtures.

  15. Rapid formation of supermassive black hole binaries in galaxy mergers with gas.

    Science.gov (United States)

    Mayer, L; Kazantzidis, S; Madau, P; Colpi, M; Quinn, T; Wadsley, J

    2007-06-29

    Supermassive black holes (SMBHs) are a ubiquitous component of the nuclei of galaxies. It is normally assumed that after the merger of two massive galaxies, a SMBH binary will form, shrink because of stellar or gas dynamical processes, and ultimately coalesce by emitting a burst of gravitational waves. However, so far it has not been possible to show how two SMBHs bind during a galaxy merger with gas because of the difficulty of modeling a wide range of spatial scales. Here we report hydrodynamical simulations that track the formation of a SMBH binary down to scales of a few light years after the collision between two spiral galaxies. A massive, turbulent, nuclear gaseous disk arises as a result of the galaxy merger. The black holes form an eccentric binary in the disk in less than 1 million years as a result of the gravitational drag from the gas rather than from the stars. PMID:17556550

  16. Rapid Formation of Supermassive Black Hole Binaries in Galaxy Mergers with Gas

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, L.; /Zurich U. /Zurich, ETH; Kazantzidis, S.; /KIPAC, Menlo Park; Madau, P.; /UC, Santa Cruz /Garching, Max Planck Inst.; Colpi, M.; /Milan Bicocca U.; Quinn, T.; /Washington U., Seattle; Wadsley, J.; /McMaster U.

    2008-03-24

    Supermassive black holes (SMBHs) are a ubiquitous component of the nuclei of galaxies. It is normally assumed that, following the merger of two massive galaxies, a SMBH binary will form, shrink due to stellar or gas dynamical processes and ultimately coalesce by emitting a burst of gravitational waves. However, so far it has not been possible to show how two SMBHs bind during a galaxy merger with gas due to the difficulty of modeling a wide range of spatial scales. Here we report hydrodynamical simulations that track the formation of a SMBH binary down to scales of a few light years following the collision between two spiral galaxies. A massive, turbulent nuclear gaseous disk arises as a result of the galaxy merger. The black holes form an eccentric binary in the disk in less than a million years as a result of the gravitational drag from the gas rather than from the stars.

  17. Modeling Phase Equilibria for Acid Gas Mixtures using the Cubic-Plus-Association Equation of State. 3. Applications Relevant to Liquid or Supercritical CO2 Transport

    DEFF Research Database (Denmark)

    Tsivintzelis, Ioannis; Ali, Shahid; Kontogeorgis, Georgios

    2014-01-01

    ” for applying CPA to acid gas mixtures. The overall conclusion is that CPA performs satisfactorily; the model in most cases correlates well binary data and predicts with good accuracy multicomponent vapor–liquid equilibria. Among the various approaches investigated, the best ones are when cross association...... of CO2 with water is accounted for or when CO2 is considered to be a self-associating molecule (with three or four sites). The final choice on the best approach requires investigating a much larger set of mixtures including also alcohols and glycols, which will be considered in future works....

  18. Metastable sound speed in gas-liquid mixtures

    Science.gov (United States)

    Bursik, J. W.; Hall, R. M.

    1979-01-01

    A new method of calculating speed of sound for two-phase flow is presented. The new equation assumes no phase change during the propagation of an acoustic disturbance and assumes that only the total entropy of the mixture remains constant during the process. The new equation predicts single-phase values for the speed of sound in the limit of all gas or all liquid and agrees with available two-phase, air-water sound speed data. Other expressions used in the two-phase flow literature for calculating two-phase, metastable sound speed are reviewed and discussed. Comparisons are made between the new expression and several of the previous expressions -- most notably a triply isentropic equation as used, a triply isentropic equation as used, among others, by Karplus and by Wallis. Appropriate differences are pointed out and a thermodynamic criterion is derived which must be satisfied in order for the triply isentropic expression to be thermodynamically consistent. This criterion is not satisfied for the cases examined, which included two-phase nitrogen, air-water, two-phase parahydrogen, and steam-water. Consequently, the new equation derived is found to be superior to the other equations reviewed.

  19. Systems and methods for removing components of a gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-09-06

    A system for removing components of a gaseous mixture is provided comprising: a reactor fluid containing vessel having conduits extending therefrom, aqueous fluid within the reactor, the fluid containing a ligand and a metal, and at least one reactive surface within the vessel coupled to a power source. A method for removing a component from a gaseous mixture is provided comprising exposing the gaseous mixture to a fluid containing a ligand and a reactive metal, the exposing chemically binding the component of the gaseous mixture to the ligand. A method of capturing a component of a gaseous mixture is provided comprising: exposing the gaseous mixture to a fluid containing a ligand and a reactive metal, the exposing chemically binding the component of the gaseous mixture to the ligand, altering the oxidation state of the metal, the altering unbinding the component from the ligand, and capturing the component.

  20. Comparative Study of Molecular Interactions in Binary Liquid Mixtures of 4 –Methyl-2-pentanoneWith Butan-2-One, Furfuraldehyde, Cyclohexanone At 308 K

    Directory of Open Access Journals (Sweden)

    D. Ubagaramary

    2016-03-01

    Full Text Available Molecular interaction studies using ultrasonic technique in the binary liquid mixtures of 4 –Methyl-2-pentanone With Butan-2-One,Furfuraldehyde and Cyclohexanonehas been carried out at different temperature. Using the measured values of ultrasonic velocity, density and viscosity, acoustical parameters and their excess values are evaluated. From these excess parametersare used to discussing about the nature and strength of the interactions in these binary systems.

  1. Derivation of an equation of surface tension isotherm for binary mixtures

    International Nuclear Information System (INIS)

    Surface tension was determined by integration of Gibbs adsorption equation from changing composition of surface layer of binary solutions with varying composition of volume solution being in equilibrium with it. The equation, which was tested for the Cd - Pb and Pb - Bi solutions at 773 K, was obtained. The isotherms of surface tension of liquid binary solutions was noted to be calculated using relation x2(ω) = f(x2) (x2(ω) - molar fraction of the second component) with rather close approximation at known dependence of the coefficient of the second component activity from the composition of solution at T = const. Surface layer of the Cd - Pb solutions was found to enrich with lead atoms

  2. Binary Adsorption Equilibrium of Benzene—Water Vapor Mixtures on Activated Carbon

    Institute of Scientific and Technical Information of China (English)

    GAOHuasheng; YEYunchun; 等

    2002-01-01

    Adsorption equilibrium isotherms of benzene in the concentration range of 500-4000mg·m-3 on two commercial activated carbons were obtained using long-column method under 30℃ and different humidity conditions. Results show that the benzene and water vapors have depression effects upon the adsorption of each other and that the unfavorable effect of water vapor resembles its single-component isotherm on activated carbon.A competitive adsorption model was proposed to explore the depression mechanisms of the non-ideal,non-similar binary adsorption systems.A modified polanyi-Dubinin equation was set up to correlate the binary adsorption equilibrium and to calculte the isotherms of benzene on activated carbon in presence of water vapor with considerable precision.

  3. Application of the Kirkwood-Buff theory of solutions to acetonitrile + amide binary mixtures by using inversion procedure and regular solution theory

    Indian Academy of Sciences (India)

    Anil Kumar Nain

    2009-05-01

    The Kirkwood-Buff (K-B) integrals play an important role in characterizing the intermolecular interactions in liquid mixtures. These are represented by the K-B parameters, AA, BB, and AB, which reflect correlation between like-like and like-unlike species in the mixture. The K-B integrals of binary mixtures of acetonitrile (ACN) with formamide (FA), N,N-dimethylformamide (DMF), N-methylacetamide (NMA) and N,N-dimethylacetamide (DMA) at 298.15 K and at atmospheric pressure have been computed from the experimental data of ultrasonic speed and density. We have used the similar inverse procedure (as proposed by Ben-Naim) to compute the K-B Parameters of the mixtures, in which thermodynamic information on mixtures such as partial molar volumes, isothermal compressibility, and experimental data of partial vapour pressures are used. A new route has been incorporated by using regular solution theory in the computation of excess free energy for obtaining the partial vapour pressures of binary liquid mixtures. The low values of excess entropy ( ≈ 0) obtained for these mixtures indicate the applicability of regular solution theory to these mixtures. The results obtained regarding intermolecular interaction in all the four mixtures under study from this new procedure are in good agreement with those obtained from the trends exhibited by the excess functions of these mixtures.

  4. Kinetically driven self-assembly of a binary solute mixture with controlled phase separation via electro-hydrodynamic flow of corona discharge.

    Science.gov (United States)

    Jung, Hee Joon; Huh, June; Park, Cheolmin

    2012-10-21

    This feature article describes a new and facile process to fabricate a variety of thin films of non-volatile binary solute mixtures suitable for high performance organic electronic devices via electro-hydrodynamic flow of conventional corona discharge. Both Corona Discharge Coating (CDC) and a modified version of CDC, Scanning Corona Discharge Coating (SCDC), are based on utilizing directional electric flow, known as corona wind, of the charged uni-polar particles generated by corona discharge between a metallic needle and a bottom plate under a high electric field (5-10 kV cm(-1)). The electric flow rapidly spreads out the binary mixture solution on the bottom plate and subsequently forms a smooth and flat thin film in a large area within a few seconds. In the case of SCDC, the static movement of the bottom electrode on which a binary mixture solution is placed provides further control of thin film formation, giving rise to a film highly uniform over a large area. Interesting phase separation behaviors were observed including nanometer scale phase separation of a polymer-polymer binary mixture and vertical phase separation of a polymer-organic semiconductor mixture. Core-shell type phase separation of either polymer-polymer or polymer-colloidal nanoparticle binary mixtures was also developed with a periodically patterned microstructure when the relative location of the corona wind was controlled to a binary solution droplet on a substrate. We also demonstrate potential applications of thin functional films with controlled microstructures by corona coating to various organic electronic devices such as electroluminescent diodes, field effect transistors and non-volatile polymer memories. PMID:22990240

  5. Kinetically driven self-assembly of a binary solute mixture with controlled phase separation via electro-hydrodynamic flow of corona discharge.

    Science.gov (United States)

    Jung, Hee Joon; Huh, June; Park, Cheolmin

    2012-10-21

    This feature article describes a new and facile process to fabricate a variety of thin films of non-volatile binary solute mixtures suitable for high performance organic electronic devices via electro-hydrodynamic flow of conventional corona discharge. Both Corona Discharge Coating (CDC) and a modified version of CDC, Scanning Corona Discharge Coating (SCDC), are based on utilizing directional electric flow, known as corona wind, of the charged uni-polar particles generated by corona discharge between a metallic needle and a bottom plate under a high electric field (5-10 kV cm(-1)). The electric flow rapidly spreads out the binary mixture solution on the bottom plate and subsequently forms a smooth and flat thin film in a large area within a few seconds. In the case of SCDC, the static movement of the bottom electrode on which a binary mixture solution is placed provides further control of thin film formation, giving rise to a film highly uniform over a large area. Interesting phase separation behaviors were observed including nanometer scale phase separation of a polymer-polymer binary mixture and vertical phase separation of a polymer-organic semiconductor mixture. Core-shell type phase separation of either polymer-polymer or polymer-colloidal nanoparticle binary mixtures was also developed with a periodically patterned microstructure when the relative location of the corona wind was controlled to a binary solution droplet on a substrate. We also demonstrate potential applications of thin functional films with controlled microstructures by corona coating to various organic electronic devices such as electroluminescent diodes, field effect transistors and non-volatile polymer memories.

  6. Thermal characteristic reliability of fatty acid binary mixtures as phase change materials (PCMs) for thermal energy storage applications

    International Nuclear Information System (INIS)

    The thermal characteristic reliability of two binary mixtures of fatty acid, myristic acid/palmitic acid/sodium myristate (MA/PA/SM) and myristic acid/palmitic acid/sodium palmitate (MA/PA/SP), were investigated using a thermal cycling test setup for 0, 1000, 2000, 3000, and 3600 heating/cooling cycles. The changes in thermal properties and chemical bonding of both eutectic PCMs were measured using Differential Scanning Calorimetric (DSC) and Fourier Transform Infrared Spectroscopy (FT-IR) analyzer, respectively. MA/PA/SM and MA/PA/SP eutectic mixtures shows only minor changes in phase transition temperature (Tm, Ts) and in latent heat of fusion (ΔHf). Moreover, the chemical bonding structures of these eutectic PCMs show no degradation and the thermal performance of those PCMs shows a good stability after 3600 thermal cycles. Therefore, it is found that the thermal characteristic stability of prepared MA/PA/SM and MA/PA/SP eutectic mixtures were acceptable for long term performance and economic feasibilities used as a phase change material (PCM) for thermal energy storage (TES) application. - Highlights: • The MA/PA/SM and MA/PA/SP were used as eutectic phase change materials (PCM). • Thermal reliability of eutectic PCMs evaluated using a thermal cycling test. • MA/PA/SP has a great thermal characteristic than MA/PA/SM after 3600 thermal cycles. • The eutectic PCMs did not show change of appearance after 3600 thermal cycles

  7. Simultaneous determination of domperidone maleate and cinnarizine in a binary mixture using derivative ratio spectrophotometry and classical least squares calibration.

    Science.gov (United States)

    Salem, Maissa Y; El-Bardicy, Mohamed G; El-Tarras, Mohamed F; El-Zanfally, Eman S

    2002-08-22

    This work is concerned with the simultaneous determination of domperidone maleate (DOM) and cinnarizine (CINN) in a binary mixture form without previous separation by two different methods. The first method is the application of derivative ratio spectrophotometry where the linearity range was 2.5-30 micro g/ml, 2.5-25 micro g/ml for DOM and CINN, respectively, and percentage recoveries were 100.26+/-1.308 and 99.86+/-0.939 for DOM and CINN, respectively, in their laboratory prepared mixtures. The second method depends on the application of classical least squares (CLS) calibration model. Two training sets were constructed and the best model was used for the prediction of the concentrations of both drugs. The proposed procedures were successfully applied for the simultaneous determination of both drugs in laboratory prepared mixtures and in commercial tablet preparations. The validity of the proposed methods was assessed by applying the standard addition technique where the percentage recovery of the added standard was found to be 99.83+/-1.861 and 98.38+/-0.871 for DOM and CINN, respectively, using the derivative ratio method and 99.53+/-0.916 and 99.39+/-0.599 for DOM and CINN, respectively, using the CLS method. The proposed procedures are rapid, simple, require no preliminary separation steps and can, therefore, be used routine analysis of both drugs in quality control laboratories. PMID:12151062

  8. Phase Equilibrium Calculation of Mixtures:Use of the SAFT-BACK Equation of State for Binary Systems under Elevated Pressure

    Institute of Scientific and Technical Information of China (English)

    张志禹; 胡中桥; 杨基础; 李以圭

    2002-01-01

    The statistical associating fluid theory (SAFT)-Boublík-Alder-Chen- Kreglewshi(BACK) equation of state is employed to correlate vapor-liquid equilibria of 16 binary mixtures composed of supercritical fluids with other fluids at elevated pressures. The van der Waals mixing rules are used and the binary parameters are adjusted to experimental data. The SAFT-BACK equation of state provides a better correlation of vapor-liquid equilibrium than the original BACK equation. Consequently, the binary parameters computed from the data sets can be used to accurately predict the saturated densities of the vapor and liquid phases.

  9. Composition and Temperature Dependence of Excess Volume of Heavy Oil-Stocks Mixtures + (Gas oil or Toluene or Reformate

    Directory of Open Access Journals (Sweden)

    Shahad Z. Atta

    2011-01-01

    Full Text Available Binary mixtures of three, heavy oil-stocks was subjected to density measurements at temperatures of 30, 35 and 40 °C. and precise data was acquired on the volumetric behavior of these systems. The results are reported in terms of equations for excess specific volumes of mixtures. The heavy oil-stocks used were of good varity, namely 40 stock, 60 stock, and 150 stock. The lightest one is 40 stock with API gravity 33.69 while 60 stock is a middle type and 150 stock is a heavy one, with API gravity 27.74 and 23.79 respectively. Temperatures in the range of 30-40 °C have a minor effect on excess volume of heavy oil-stock binary mixture thus, insignificant expansion or shrinkage is observed by increasing the temperature this effect becomes more significant although the heavy oil-stocks is spiked with hydrocarbons like (gas oil, toluene and reformate. Blending of Heavy oil-stocks with hydrocarbons spikes (gas oil, toluene and reformate form non-ideal mixtures, for which excess volume can be positive or negative depending on nature species. Spiking of Heavy oil-stocks with either gas oil or reformate resulted in negative excess volume. This shrinkage is greater for the lowest boiling point spike as in the case of reformate, While, the presence of methyl groups in aromatic rings results in a positive excess volume, as shown in toluene when blended with 40 stock but a negative excess volume was found when blended with 60 stock and 150 stock. The API gravity of heavy oil-stocks has an effect on excess volume when the oil-stocks spiked with hydrocarbons like (gas oil, toluene and reformate. This 40 stocks as a typical light types resulted in minimum negative excess volume of -0.47 at 30 °C, when it was spiked with the gas oil; while the spiked heavy oil-stock with kerosene shows a maximum excess volume of -15.56 at 40 °C.

  10. Modeling derivative properties and binary mixtures with CO2 using the CPA and the quadrupolar CPA equations of state

    DEFF Research Database (Denmark)

    Bjørner, Martin Gamel; Kontogeorgis, Georgios

    2016-01-01

    vapor-liquid equilibria (VLE) and liquid-liquid equilibria (LLE) of mixtures containing CO2 and hydrocarbons, water, alcohols, or selected quadrupolar compounds.The results indicate that most pure compound property predictions are satisfactory but similar to other CPA approaches. When binary mixtures...... (qCPA) can be used without introducing any additional pure compound parameters. Alternatively a single additional adjustable parameter can be employed.To evaluate qCPA several pure compound properties are predicted. The model is furthermore evaluated for its ability to predict and correlate binary...

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

    Science.gov (United States)

    Pousaneh, Faezeh; Edholm, Olle; Maciołek, Anna

    2016-07-01

    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.

  12. Effects of Microporosity and Surface Chemistry on Separation Performances of N-Containing Pitch-Based Activated Carbons for CO2/N2 Binary Mixture

    Science.gov (United States)

    Lee, Min-Sang; Park, Mira; Kim, Hak Yong; Park, Soo-Jin

    2016-03-01

    In this study, N-containing pitch-based activated carbons (NPCs) were prepared using petroleum pitch with a low softening point and melamine with a high nitrogen content. The major advantage of the preparation method is that it enables variations in chemical structures and textural properties by steam activation at high temperatures. The adequate micropore structures, appropriate chemical modifications, and high adsorption enthalpies of NPCs are favorable for CO2 adsorption onto carbon surfaces. Furthermore, the structure generates a considerable gas/N-containing carbon interfacial area, and provides selective access to CO2 molecules over N2 molecules by offering an increased number of active sites on the carbon surfaces. The highest CO2/N2 selectivity, i.e., 47.5, and CO2 adsorption capacity for a CO2/N2 (0.15:0.85) binary gas mixture, i.e., 5.30 wt%, were attained at 298 K. The NPCs also gave reversible and durable CO2-capturing performances. All the results suggest that NPCs are promising CO2 sorbents, which can meet the challenges of current CO2 capture and separation techniques.

  13. Effects of Microporosity and Surface Chemistry on Separation Performances of N-Containing Pitch-Based Activated Carbons for CO2/N2 Binary Mixture

    Science.gov (United States)

    Lee, Min-Sang; Park, Mira; Kim, Hak Yong; Park, Soo-Jin

    2016-01-01

    In this study, N-containing pitch-based activated carbons (NPCs) were prepared using petroleum pitch with a low softening point and melamine with a high nitrogen content. The major advantage of the preparation method is that it enables variations in chemical structures and textural properties by steam activation at high temperatures. The adequate micropore structures, appropriate chemical modifications, and high adsorption enthalpies of NPCs are favorable for CO2 adsorption onto carbon surfaces. Furthermore, the structure generates a considerable gas/N-containing carbon interfacial area, and provides selective access to CO2 molecules over N2 molecules by offering an increased number of active sites on the carbon surfaces. The highest CO2/N2 selectivity, i.e., 47.5, and CO2 adsorption capacity for a CO2/N2 (0.15:0.85) binary gas mixture, i.e., 5.30 wt%, were attained at 298 K. The NPCs also gave reversible and durable CO2-capturing performances. All the results suggest that NPCs are promising CO2 sorbents, which can meet the challenges of current CO2 capture and separation techniques. PMID:26987683

  14. Gas-phase detonation propagation in mixture composition gradients.

    Science.gov (United States)

    Kessler, D A; Gamezo, V N; Oran, E S

    2012-02-13

    The propagation of detonations through several fuel-air mixtures with spatially varying fuel concentrations is examined numerically. The detonations propagate through two-dimensional channels, inside of which the gradient of mixture composition is oriented normal to the direction of propagation. The simulations are performed using a two-component, single-step reaction model calibrated so that one-dimensional detonation properties of model low- and high-activation-energy mixtures are similar to those observed in a typical hydrocarbon-air mixture. In the low-activation-energy mixture, the reaction zone structure is complex, consisting of curved fuel-lean and fuel-rich detonations near the line of stoichiometry that transition to decoupled shocks and turbulent deflagrations near the channel walls where the mixture is extremely fuel-lean or fuel-rich. Reactants that are not consumed by the leading detonation combine downstream and burn in a diffusion flame. Detonation cells produced by the unstable reaction front vary in size across the channel, growing larger away from the line of stoichiometry. As the size of the channel decreases relative to the size of a detonation cell, the effect of the mixture composition gradient is lessened and cells of similar sizes form. In the high-activation-energy mixture, detonations propagate more slowly as the magnitude of the mixture composition gradient is increased and can be quenched in a large enough gradient. PMID:22213660

  15. 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.

  16. Extension of some numerical schemes to the analysis of gas and particle mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Cascales, J. R.; Mulas-Perez, J. [UPCT, Dept Ingn Quim Term and Fluidos, Murcia 30202, (Spain); Paillere, H. [CEA Saclay, DM2S/SFME, Lab Etudes Transferts Mecan Fluides, F-91191 Gif Sur Yvette, (France)

    2008-07-01

    In this paper, several numerical schemes are extended to obtain approximate solutions to the system of equations encountered in the analysis of multiphase mixtures of gas and particles. Both dense and dilute mixtures are studied, the gas is modelled as a perfect gas and the solid is considered incompressible. Although the tests employed throughout this work for studying the behaviour of the schemes are essentially one dimensional, the finite volume method developed permits its application to multidimensional problems in unstructured grids. (authors)

  17. 49 CFR 173.305 - Charging of cylinders with a mixture of compressed gas and other material.

    Science.gov (United States)

    2010-10-01

    ... nonflammable mixtures. Mixtures containing compressed gas or gases including insecticides, which mixtures are... relief devices of a type examined by the Bureau of Explosives and approved by the Associate...

  18. The impact of air-fuel mixture composition on SI engine performance during natural gas and producer gas combustion

    Science.gov (United States)

    Przybyła, G.; Postrzednik, S.; Żmudka, Z.

    2016-09-01

    The paper summarizers results of experimental tests of SI engine fuelled with gaseous fuels such as, natural gas and three mixtures of producer gas substitute that simulated real producer gas composition. The engine was operated under full open throttle and charged with different air-fuel mixture composition (changed value of air excess ratio). The spark timing was adjusted to obtain maximum brake torque (MBT) for each fuel and air-fuel mixture. This paper reports engine indicated performance based on in-cylinder, cycle resolved pressure measurements. The engine performance utilizing producer gas in terms of indicated efficiency is increased by about 2 percentage points when compared to fuelling with natural gas. The engine power de-rating when producer gas is utilized instead the natural gas, varies from 24% to 28,6% under stoichiometric combustion conditions. For lean burn (λ=1.5) the difference are lower and varies from 22% to 24.5%.

  19. Evidencing molecular associations in binary liquid mixtures via photothermal measurements of thermophysical parameters

    NARCIS (Netherlands)

    Neamtu, C.; Dadarlat, D.; Chirtoc, M.; Sahraoui, A.H.; Longuemart, S.; Bicanic, D.D.

    2006-01-01

    The back photopyroelectric (PPE) configuration, with opaque sample and thermally thick sample and sensor, was applied in order to obtain room temperature values of the thermal diffusivity of some liquid mixtures. The methodology is based on a sample's thickness scan, and not on a frequency scan as i

  20. CO2 capture from binary mixture via forming hydrate with the help of tetra-n-butyl ammonium bromide

    Institute of Scientific and Technical Information of China (English)

    Shifeng Li; Shuanshi Fan; Jingqu Wang; Xuemei Lang; Deqing Liang

    2009-01-01

    Hydrate formation rate and separation effect on the capture of CO2 from binary mixture v/a forming hydrate with 5 wt% tetra-n-butyl ammonium bromide (TBAB) solution were studied.The results showed that the induction time was 5 min,and the hydrate formation process pressure of 7.30 MPa.The CO2 recovery was about 45% in the feed pressure range from 4.30 to 7.30 MPa.Under the feed pressure of 4.30 MPa,the maximum separation factor and CO2 concentration in hydrate phase were 7.3 and 38.2 tool%,respectively.The results demonstrated that TBAB accelerated hydrate formation and enriched CO2 in hydrate phase under the gentle condition.

  1. Using Raman Spectroscopy and ab initio Calculations to Investigate lntermolecular Hydrogen Bonds in Binary Mixture (Tetrahydrofuran+Water)

    Institute of Scientific and Technical Information of China (English)

    WU Nan-nan; OUYANG Shun-li; LI Zuo-wei; LIU Jing-yao; GAO Shu-qin

    2011-01-01

    We analyzed the properties and structures of the hydrogen-bonded complexes of tetrahydrofuran(THF)and water by means of experimental Raman spectra and ab initio calculations.The optimized geometries and vibrational frequencies of the neat THF molecule and its hydrogen-bonded complexes with water(THF/H2O) were calculated at the MP2/6-31 l+G(d,p) level of theory.We found that the intermolecular hydrogen bonds which are formed from the binary mixtures of the neat THF and water with different molar ratios could explain the changes in wavenumber position and linewidth very well.The combination of ab initio calculations and experimental Raman spectral data provides an insight into the hydrogen bonds leading to the concentration dependent changes in the spectral features.

  2. Thermophysical Properties of Binary Mixtures of Dimethylsulfoxide with 1-Phenylethanone and 1,4-Dimethylbenzene at Various Temperatures

    Directory of Open Access Journals (Sweden)

    Harmandeep Singh Gill

    2014-01-01

    Full Text Available This research article reports the experimental results of the density, viscosity, refractive index, and speed of sound analysis of binary mixtures of dimethylsulfoxide (DMSO + 1-phenylethanone (acetophenone and + 1,4-dimethylbenzene (para-xylene over the whole composition range at 313.15, 318.15, 323.15, and 328.15 K and at atmospheric pressure. The excess molar volumes (VE, viscosity deviations (Δη, excess Gibbs energy of activation (GE, deviations in isentropic compressibility (KSE, deviations in speed of sound (uE, and deviations in the molar refraction (ΔR were calculated from the experimental data. The computed quantities were fitted to the Redlich-Kister equation to derive the coefficients and estimate the standard error values. The viscosities have also been correlated with two, and three-parameter models, that is, Heric correlation, McAllister model, and Grunberg-Nissan correlation, respectively.

  3. Viscosities and viscosity deviations of binary mixtures of biodiesel + petrodiesel (or n-hexadecane at different temperatures

    Directory of Open Access Journals (Sweden)

    F. M. R. Mesquita

    2012-09-01

    Full Text Available Viscosities of four binaries mixtures [soybean biodiesel + diesel oil (or n-hexadecane and coconut biodiesel + diesel oil (or n-hexadecane] have been determined at T = (293.15, 313.15, 333.15, 353.15, 373.15 K and atmospheric pressure over the entire composition range. Experimental data were fitted to the Andrade equation and the adjustable parameters and the standard deviations between experimental and calculated values were estimated. From the experimental data, the viscosity deviations, , were calculated by using the Redlich - Kister polynomial equation. The comparison between experimental data determined in this work and four predictive methods used for the estimation of viscosities of biodiesel fuels (based on their fatty acid composition is discussed.

  4. Transport properties of binary mixtures of carbon dioxide and 1-butyl-3-methylimidazolium hexafluorophosphate studied by transient grating spectroscopy.

    Science.gov (United States)

    Demizu, Masashi; Terazima, Masahide; Kimura, Yoshifumi

    2008-10-01

    Transient grating spectroscopy was applied to measurements of sound velocity and thermal diffusivity in binary mixture solutions of carbon dioxide (CO(2)) and 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF(6)]) along the saturated line of CO(2) at 40 degrees C up to 20.0 MPa. The sound velocity decreased more than 10% by increasing the pressure to 10 MPa, and the pressure effect was very small above 10 MPa. The change in the thermal diffusivity was small. The translational diffusion coefficients of carbon monoxide, diphenylacetylene (DPA), and diphenylcyclopropenone (DPCP) were also determined. The diffusion coefficients increased up to 10 MPa, and the pressure effect was almost saturated above 10 MPa. The pressure dependence of the diffusion coefficients of DPCP and DPA was larger than that of carbon monoxide. The results are discussed in relation with the viscosity change caused by applying pressure. PMID:18845895

  5. Densities, Viscosities, Speeds of Sound, and Refractive Indices of Binary Mixtures of 2-Ethyl-1-hexanol with Benzene and Halobenzenes

    Science.gov (United States)

    Bhatia, Subhash C.; Sangwan, Jasbir; Rani, Ruman; Kiran, Vijay

    2013-11-01

    Densities, , viscosities, , speeds of sound, , and refractive indices, , of binary liquid mixtures of 2-ethyl-1-hexanol with benzene, chlorobenzene, and bromobenzene have been measured over the entire range of composition at 298.15 K, 303.15 K, and 308.15 K and at atmospheric pressure. From the experimental data of the density, speed of sound, viscosity, and refractive index, the values of the excess molar volume, , isentropic compressibility, , and deviations in molar refraction, , have been calculated. The viscosity data have been correlated using McAllister's three-body interaction model at different temperatures. The calculated excess and deviation functions have been analyzed in terms of molecular interactions and structural effects.

  6. On the unsteady-state species separation of a binary liquid mixture in a rectangular thermogravitational column.

    Science.gov (United States)

    Haugen, Kjetil B; Firoozabadi, Abbas

    2006-02-01

    This paper investigates the unsteady-state species segregation of binary liquid mixtures in rectangular thermogravitational columns. The analysis leads to a procedure to obtain both molecular and thermal diffusion coefficients from transient separation measurements. Two models are presented: first, an ideal model where buoyancy only depends on temperature and second, a general model where buoyancy also varies with composition. Steady-state measurements are not required regardless of which model is chosen. As a result, the new procedure is faster than steady-state procedures. When either the molecular or thermal diffusion coefficient is known a priori, the other can be obtained without knowledge of fluid properties such as density, viscosity, thermal expansion, and compositional coefficients. PMID:16468889

  7. Densities, Viscosities, Speeds of Sound, and Refractive Indices of Binary Mixtures of 1-Decanol with Isomeric Chlorotoluenes

    Science.gov (United States)

    Bhatia, Subhash C.; Rani, Ruman; Sangwan, Jasbir; Bhatia, Rachna

    2011-06-01

    Densities, ρ, viscosities, η, speeds of sound, u, and refractive indices, n D, of binary liquid mixtures of 1-decanol with o-chlorotoluene, m-chlorotoluene, and p-chlorotoluene have been measured over the entire range of composition at 298.15 K, 303.15 K, and 308.15 K and at atmospheric pressure. From the experimental data of density, speed of sound, viscosity and refractive index, the values of the excess molar volume, V E, deviations in isentropic compressibility, Δ κ S , and deviations in molar refraction, Δ R, have been calculated. The calculated excess and deviation functions have been analyzed in terms of molecular interactions and structural effects.

  8. Quantum dynamics of a binary mixture of BECs in a double-well potential: a Holstein-Primakoff approach

    Energy Technology Data Exchange (ETDEWEB)

    Citro, Roberta; Naddeo, Adele [Dipartimento di Fisica ' E. R. Caianiello' , Universita degli Studi di Salerno, Via Ponte Don Melillo, 84084 Fisciano (Saudi Arabia) (Italy); Orignac, Edmond, E-mail: citro@sa.infn.it, E-mail: naddeo@sa.infn.it, E-mail: Edmond.Orignac@ens-lyon.fr [Laboratoire de Physique, CNRS-UMR5672, Ecole Normale Superieure de Lyon, 46, Allee d' Italie, 69364 Lyon Cedex 07 (France)

    2011-06-14

    We study the quantum dynamics of a binary mixture of Bose-Einstein condensates (BECs) in a double-well potential starting from a two-mode Bose-Hubbard Hamiltonian. Focussing on the regime where the number of atoms is very large, a mapping onto an SU(2) spin problem together with a Holstein-Primakoff transformation is performed. The quantum evolution of the number difference of bosons between the two wells is investigated for different initial conditions, which range from the case of a small imbalance between the two wells to a coherent spin state. The results show an instability towards a phase separation above a critical positive value of the interspecies interaction while the system evolves towards a coherent tunnelling regime for negative interspecies interactions. A comparison with a semiclassical approach is discussed together with some implications on the experimental realization of phase separation with cold atoms.

  9. Buffer gas-induced resonance vibrational polarizability in the SF6-rare gas mixtures

    Science.gov (United States)

    Bulanin, Michael O.; Burtsev, Andrey P.; Kerl, Klaus; Kisliakov, Ivan M.

    2001-04-01

    Mixed second refractivity virial coefficients BRab(ω) have been evaluated from the analysis of the pressure broadened ν3≈930 cm-1 34SF6 IR absorption band profile in mixtures with Ne, Ar, Kr, and Xe buffer gases at relative densities up to 150 Amagat. The values of the BRab(ω) in the resonance region are found to be orders of magnitude greater compared to those observed for the neat gases in the spectral regions far from resonance. The experimental results are compared with the predictions of the dynamic DID model for the buffer gas-induced vibrational pair polarizability. The DID model reproduces surprisingly well the frequency variation of BRab in the range of the band wings for the heavier buffer gases, but significantly deviates from experiment for the SF6-Ne mixture.

  10. Assessment of the micro-structure and depletion potentials in two-dimensional binary mixtures of additive hard-disks.

    Science.gov (United States)

    Perera-Burgos, Jorge Adrián; Méndez-Alcaraz, José Miguel; Pérez-Ángel, Gabriel; Castañeda-Priego, Ramón

    2016-09-14

    Depletion forces are a particular class of effective interactions that have been mainly investigated in binary mixtures of hard-spheres in bulk. Although there are a few contributions that point toward the effects of confinement on the depletion potential, little is known about such entropic potentials in two-dimensional colloidal systems. From theoretical point of view, the problem resides in the fact that there is no general formulation of depletion forces in arbitrary dimensions and, typically, any approach that works well in three dimensions has to be reformulated for lower dimensionality. However, we have proposed a theoretical framework, based on the formalism of contraction of the description within the integral equations theory of simple liquids, to account for effective interactions in colloidal liquids, whose main feature is that it does not need to be readapted to the problem under consideration. We have also shown that such an approach allows one to determine the depletion pair potential in three-dimensional colloidal mixtures even near to the demixing transition, provided the bridge functions are sufficiently accurate to correctly describe the spatial correlation between colloids [E. López-Sánchez et al., J. Chem. Phys. 139, 104908 (2013)]. We here report an extensive analysis of the structure and the entropic potentials in binary mixtures of additive hard-disks. In particular, we show that the same functional form of the modified-Verlet closure relation used in three dimensions can be straightforwardly employed to obtain an accurate solution for two-dimensional colloidal mixtures in a wide range of packing fractions, molar fractions, and size asymmetries. Our theoretical results are explicitly compared with the ones obtained by means of event-driven molecular dynamics simulations and recent experimental results. Furthermore, to assess the accuracy of our predictions, the depletion potentials are used in an effective one-component model to reproduce

  11. Interfacial properties of binary mixtures of square-well molecules from Monte Carlo simulation

    Science.gov (United States)

    Martínez-Ruiz, F. J.; Blas, F. J.

    2016-04-01

    We determine the interfacial properties of mixtures of spherical square-well molecules from direct simulation of the vapor-liquid interface. We consider mixtures with the same molecular size and intermolecular potential range but different dispersive energy parameter values. We perform Monte Carlo simulations in the canonical ensemble to obtain the interfacial properties of mixtures of square-well molecules. In particular, we determine the pressure tensor using the mechanical (virial) route and the vapor-liquid interfacial tension evaluated using the Irving-Kirkwood method. In addition to the pressure tensor and the surface tension, we also obtain density profiles, coexistence densities, and interfacial thickness as functions of pressure, at a given temperature. This work can be considered as the extension of our previous work [F. J. Martínez-Ruiz and F. J. Blas, Mol. Phys. 113, 1217 (2015)] to deal with mixtures of spherical molecules that interact through a discontinuous intermolecular potential. According to our results, the main effect of increasing the ratio between the dispersive energy parameters of the mixture, ɛ22/ɛ11, is to sharpen the vapor-liquid interface and to increase the width of the biphasic coexistence region. Particularly interesting is the presence of a relative maximum in the density profiles of the more volatile component at the interface. This maximum is related with adsorption or accumulation of these molecules at the interface, since there are stronger attractive interactions between these molecules in comparison with the rest of intermolecular interactions. Also, the interfacial thickness decreases and the surface tension increases as ɛ22/ɛ11 is larger, a direct consequence of the increasing of the cohesive energy of the system.

  12. Microwave induced synthesis of graft copolymer of binary vinyl monomer mixtures onto delignified Grewia optiva fibre: Application in dye removal

    Science.gov (United States)

    Gupta, Vinod; Pathania, Deepak; Priya, Bhanu; Singha, A. K.; Sharma, Gaurav

    2014-08-01

    Grafting method, through microwave radiation technique is very effective in terms of time consumption, cost effectiveness and environmental friendliness. Via this method, delignified Grewia optiva identified as a waste biomass, was graft copolymerized with methylmethacrylate (MMA) as an principal monomer in a binary mixture of ethyl methacrylate (EMA) and ethyl acrylate (EA) under microwave irradiation (MWR) using ascorbic acid/H2O2 as an initiator system. The concentration of the comonomer was optimized to maximize the graft yield with respect to the primary monomer. Maximum graft yield (86.32%) was found for dGo-poly(MMA-co-EA) binary mixture as compared to other synthesized copolymer. The experimental results inferred that the optimal concentrations for the comonomers to the optimized primary monomer was observed to be 3.19 mol/L×10-1 for EMA and 2.76 mol/L×10-1 for EA. Delignified and graft copolymerized fibre were subjected to evaluation of physicochemical properties such as swelling behaviour and chemical resistance. The synthesized graft copolymers were characterized with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray diffraction techniques. Thermal stability of dGo-poly(MMA-co-EA) was found to be more as compared to the delignified Grewia optiva fibre and other graft copolymers. Although the grafting technique was found to decrease percentage crystallinity and crystallinity index among the graft copolymers but there was significant increase in their acid/base and thermal resistance properties. The grafted samples have been explored for the adsorption of hazardous methylene dye from aqueous system.

  13. Molecular dynamics simulations of heat and mass transport properties of a simple binary mixture in micro/meso-pores

    International Nuclear Information System (INIS)

    Graphical abstract: Thermodiffusion factors relatively to the bulk value versus pore size for p∥∗=0.5 (full symbol) and p∥∗=1 (open symbol). The full circles correspond to the results for purely repulsive walls, the square to the moderately adsorbent walls and the down triangles to the highly adsorbent walls. Highlights: ► Molecular dynamics of heat and mass transport coefficients in micro/meso pores. ► Analysis of the influence of the pore width and fluid–solid interaction. ► Negligible effect for pore width larger than 10 molecular sizes. ► Thermodiffusion decreases noticeably for the thinnest pore. ► Trends on transport properties explained by changes in the average density. - Abstract: In this work, we have studied thermodiffusion of simple binary mixtures confined in a slit pore of nanometer width. To do so we have performed Non-Equilibrium Molecular Dynamics simulations of Lennard-Jones binary equimolar mixtures confined in structureless walls of three adsorbent natures, various widths (3–30 times the size of a molecule) and for two different thermodynamic states. The results showed that the width of the pore has a weak effect on the effective thermodiffusion factor, thermodiffusion coefficients and thermal conductivities for pore width larger than 10 times the size of the molecules. However, for narrower pore, all transport properties are noticeably affected and in particular thermodiffusion tends to decrease with the decrease of the pore width. These general trends on the transport properties in the smallest pores can be qualitatively explained by the impact of the confinement on the average density.

  14. 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.

  15. Solubilization of Phenanthrene and Fluorene in Equimolar Binary Mixtures of Gemini/Conventional Surfactants

    Institute of Scientific and Technical Information of China (English)

    Huma Siddiqui; Mohammad Kamil; Manorama Panda; Kabir-ud-Din

    2014-01-01

    abstract This study deals with the enhanced solubilization of polycyclic aromatic hydrocarbons (PAHs) such as phenan-threne (PHE) and fluorene (FLR) in a pure cationic gemini (G6) and three conventional surfactants [polyethylene glycol dodecyl ether (Brij35), cetyltrimethyl ammonium bromide (CTAB) and sodium lauryl sulfate (SDS)] as well as in their equimolar binary combinations (G6-Brij35, G6-CTAB and G6-SDS). Their solubilization efficiency toward PHE and FLR has been quantified in terms of the molar solubilization ratio (MSR) and the micelle-water partition coefficient (Km). The ideality/nonideality of the mixed micelles is discussed with the help of Clint, Rubingh and Rosen's approaches. These theories determine the deviation of experimental critical micelle concen-tration (CMC) values from ideal critical micelle concentration, which was measured by evaluating the interaction parameters (βm andβσ). Negative values ofβm were observed in all the equimolar binary systems, which show synergism in the mixed micelles. Whereas at air/liquid interface synergism was observed in the systems G6-CTAB and G6-Brij35; G6-SDS exhibited an antagonistic effect. The order of MSR and Km was G6-CTAB N G6-Brij35 N G6-SDS for phenanthrene as well as for fluorene.

  16. Electron degradation and yields of initial products. I. Excited species generated by electrons in binary mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, M.; Inokuti, M.

    1987-10-01

    Initial yields of excited species resulting from electron degradation in Ar+H/sub 2/ mixtures have been calculated using the Fowler equation. Following up the previous study of yields of ions by Eggarter (J. Chem. Physl 84, 6123 (1986)) and by Inokuti and Eggarter (J. Chem. Phys. 86, 3870 (1987)), the present work treats initial yields of excited species over the entire range of the composition of Ar+H/sub 2/ mixtures. The variation of the yield with the composition depends on the kind of excited species. The most noteworthy of the results obtained concerns the Ar metastable-state yield, which shows peculiar behavior when a small amount of H/sub 2/ is introduced in the media.

  17. Tracer diffusion of hard-sphere binary mixtures under nano-confinement

    Science.gov (United States)

    Marini Bettolo Marconi, Umberto; Malgaretti, Paolo; Pagonabarraga, Ignacio

    2015-11-01

    The physics of diffusion phenomena in nano- and microchannels has attracted a lot of attention in recent years, due to its close connection with many technological, medical, and industrial applications. In the present paper, we employ a kinetic approach to investigate how the confinement in nanostructured geometries affects the diffusive properties of fluid mixtures and leads to the appearance of properties different from those of bulk systems. In particular, we derive an expression for the friction tensor in the case of a bulk fluid mixture confined to a narrow slit having undulated walls. The boundary roughness leads to a new mechanism for transverse diffusion and can even lead to an effective diffusion along the channel larger than the one corresponding to a planar channel of equivalent section. Finally, we discuss a reduction of the previous equation to a one dimensional effective diffusion equation in which an entropic term encapsulates the geometrical information on the channel shape.

  18. 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.

  19. Binary and Ternary Mixtures of Biopolymers and Water: Viscosity, Refractive Index, and Density

    Science.gov (United States)

    Silva, Bárbara Louise L. D.; Costa, Bernardo S.; Garcia-Rojas, Edwin E.

    2016-08-01

    Biopolymers have been the focus of intense research because of their wide applicability. The thermophysical properties of solutions containing biopolymers have fundamental importance for engineering calculations, as well as for thermal load calculations, energy expenditure, and development of new products. In this work, the thermophysical properties of binary and ternary solutions of carboxymethylcellulose and/or high methoxylation pectin and water at different temperatures have been investigated taking into consideration different biopolymer concentrations. The experimental data related to the thermophysical properties were correlated to obtain empirical models that can describe the temperature-concentration combined effect on the density, refractive index, and dynamic viscosity. From data obtained from the experiments, the density, refractive index, and dynamic viscosity increase with increasing biopolymer concentration and decrease with increasing temperature. The polynomial models showed a good fit to the experimental data and high correlation coefficients (R2ge 0.98) for each studied system.

  20. Equilibrium and thermodynamic parameters of single and binary mixture biosorption of lead (II) and copper (II) ions onto Pseudomonas putida: Effect of temperature

    International Nuclear Information System (INIS)

    The biosorption of lead (II) and copper (II) ions, single component and binary systems, by dried P. putida was investigated in a batch system. The effects of initial pH, temperature, initial single and binary mixture concentrations on the biosorption kinetics and equilibrium uptake of each component, both single and binary mixtures were investigated. The bacterial biomass exhibited the highest single and binary lead (II) and copper (II) ions uptake capacity at 25 and 30 deg. C, respectively, the initial pH value of 5.5 and at the initial metal ions concentration of 100 mg dm-3. The Freundlich and Langmuir adsorption models were used for the mathematical description of the biosorption equilibrium and isotherm constants were evaluated at different temperatures. Adsorption data were well described by the Langmuir model, although they could be modeled by the Freundlich equation. The thermodynamics constants of the adsorption process: ΔHo, ΔSo and ΔGo were evaluated. The results showed that biosorption of single and binary lead (II) ions on P. putida were exothermic and spontaneous. While biosorption of single and binary copper (II) ions on P. putida was endothermic and spontaneous

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

    Science.gov (United States)

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

    2014-02-01

    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.

  2. 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.

  3. Separation of species of a binary fluid mixture confined in a channel in presence of a strong transverse magnetic field

    Directory of Open Access Journals (Sweden)

    Sharma Bishwaram

    2012-01-01

    Full Text Available Effects of a transverse magnetic field on separation of a binary mixture of incompressible viscous thermally and electrically conducting fluids confined between two stationary parallel plates are examined. Both the plates are maintained at constant temperatures. It is assumed that one of the components, which is rarer and lighter, is present in the mixture in a very small quantity. The equations governing the motion, temperature and concentration in Cartesian coordinate are solved analytically. The solution obtained for concentration distribution is plotted against the width of the channel for various values of non-dimensional parameters. It is found that the effect of transverse magnetic field is to separate the species of rarer and lighter component by contributing its effect directly to the temperature gradient and the pressure gradient. The effects of increase in the values of Hartmann number, magnetic Reynolds number, barodiffusion number, thermal diffusion number, electric field parameter and the product of Prandtl number and Eckert number are to collect the rarer and lighter component near the upper plate and throw away the heavier component towards the lower plate. The problem discussed here derives its application in the basic fluid dynamics separation processes to separate the rare component of the different isotopes of heavier molecules where electromagnetic method of separation does not work.

  4. The solid-liquid phase diagrams of binary mixtures of even saturated fatty acids differing by six carbon atoms

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Mariana C. [LPT, Department of Chemical Process, School of Chemical Engineering, University of Campinas, UNICAMP, P.O. Box 6066, 13083-970, Campinas-SP (Brazil); EXTRAE, Department of Food Engineering, Faculty of Food Engineering, University of Campinas, UNICAMP, P.O. Box 6121, 13083-862, Campinas-SP (Brazil); CICECO, Departamento de Quimica da Universidade de Aveiro, 3810-193 Aveiro (Portugal); Rolemberg, Marlus P. [DETQI, Department of Chemical Technology, Federal University of Maranhao (UFMA), Sao Luis, Maranhao (Brazil); Meirelles, Antonio J.A. [EXTRAE, Department of Food Engineering, Faculty of Food Engineering, University of Campinas, UNICAMP, P.O. Box 6121, 13083-862, Campinas-SP (Brazil); Coutinho, Joao A.P. [CICECO, Departamento de Quimica da Universidade de Aveiro, 3810-193 Aveiro (Portugal); Kraehenbuehl, M.A., E-mail: mak@feq.unicamp.br [LPT, Department of Chemical Process, School of Chemical Engineering, University of Campinas, UNICAMP, P.O. Box 6066, 13083-970, Campinas-SP (Brazil)

    2009-12-10

    This study was aimed at using the solid-liquid phase diagrams for three binary mixtures of saturated fatty acids, especially the phase transitions below the liquidus line. These mixtures are compounded by caprylic acid (C{sub 8:0}) + myristic acid (C{sub 14:0}), capric acid (C{sub 10:0}) + palmitic acid (C{sub 16:0}), lauric acid (C{sub 12:0}) + stearic acid (C{sub 18:0}), differing by six carbon atoms between carbon chains. The phase diagrams were obtained by differential scanning calorimetry (DSC). The polarized light microscopy was used to complement the characterization for a full grasp of the phase diagram. Not only do these phase diagrams present peritectic and eutectic reactions, but also metatectic reactions, due to solid-solid phase transitions common, in fatty acids. These findings have contributed to the elucidation of the phase behavior of these important biochemical molecules with implications in various industrial production.

  5. 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.

  6. Comparative study of spectrophotometric methods manipulating ratio spectra: An application on pharmaceutical binary mixture of cinnarizine and dimenhydrinate

    Science.gov (United States)

    Lamie, Nesrine T.

    2015-04-01

    Four simple, specific, accurate and precise spectrophotometric methods are developed and validated for simultaneous determination of cinnarizine (CIN) and dimenhydrinate (DIM) in a binary mixture with overlapping spectra, without preliminary separation. The first method is dual wavelength spectrophotometry (DW), the second is a ratio difference spectrophotometric one (RD) which measures the difference in amplitudes between 250 and 270 nm of ratio spectrum, the third one is novel constant center spectrophotometric method (CC) and the fourth method is mean centering of ratio spectra (MCR). The calibration curve is linear over the concentration range of 4-20 and 10-45 μg/ml for CIN and DIM, 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. The validity of results was assessed by applying standard addition technique. The results obtained were found to agree statistically with those obtained by a reported method, showing no significant difference with respect to accuracy and precision.

  7. Ultrasonic velocity and absorption study of binary mixtures of cyclohexane with acrylonitrile by interferometric method at different frequencies

    International Nuclear Information System (INIS)

    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.

  8. Numerical solution of the nonequilibrium square-gradient model and verification of local equilibrium for the Gibbs surface in a two-phase binary mixture

    NARCIS (Netherlands)

    Glavatskiy, K.S.; Bedeaux, D.

    2009-01-01

    In this paper we apply the general analysis described in our first paper to a binary mixture of cyclohexane and n-hexane. We use the square gradient model for the continuous description of a nonequilibrium surface and obtain numerical profiles of various thermodynamic quantities in various stationar

  9. Anomalous Temperature Dependence of the Elastic Constant B at the Smectic-to-Nematic Phase Transition in Binary Mixtures of Hexyloxycyanobiphenyl-Octyloxycyanobiphenyl (60CB-80CB)

    OpenAIRE

    Fisch, M. R.; Sorensen, L. B.; Pershan, Peter S.

    1982-01-01

    In hexyloxycyanobiphenyl-octyloxycyanobiphenyl (60CB-80CB) binary mixtures displaying reentrant behavior, the smectic elastic constant, B, deviates from a simple power law of the form \\(B=B_1(T_{NA}-T)^{\\varphi}\\) and levels off as \\(T \\rightarrow T_{NA}\\). This behavior is consistent with the Nelson-Toner dislocation-unbinding model of the transition.

  10. A custom on-line ultrasonic gas mixture analyzer with simultaneous flowmetry developed for use in the LHC-ATLAS experiment, with wide application in high and low flow gas delivery systems

    International Nuclear Information System (INIS)

    We describe a combined ultrasonic instrument for continuous gas flow measurement and simultaneous real-time binary gas mixture analysis. In the instrument, sound bursts are transmitted in opposite directions, which may be aligned with the gas flow path or at an angle to it, the latter configuration being the best adapted to high flow rates. Custom electronics based on Microchip R dsPIC and ADuC847 micro-controllers transmits 50 kHz ultrasound pulses and measures transit times in the two directions together with the process gas temperature and pressure. The combined flow measurement and mixture analysis algorithm exploits the phenomenon whereby the sound velocity in a binary gas mixture at known temperature and pressure is a unique function of the molar concentration of the two components. The instrument is central to a possible upgrade to the present ATLAS silicon tracker cooling system in which octafluoro-propane (C3F8) evaporative cooling fluid would be replaced by a blend containing up to 25% hexafluoro-ethane (C2F6). Such a blend will allow a lower evaporation temperature and will afford the tracker silicon substrates a better safety margin against leakage current-induced thermal runaway caused by cumulative radiation damage as the luminosity profile at the CERN Large Hadron Collider (LHC) increases. The instrument has been developed in two geometries following computational fluid dynamics studies of various mechanical layouts. An instrument with 45 crossing angle has been built in stainless steel and installed for commissioning in the ATLAS silicon tracker evaporative fluorocarbon cooling system. It can be used in gas flows up to 20000 l.min-1, and has demonstrated a flow resolution of 2.3% of full scale for linear flow velocities up to 10 m.s-1 in preliminary studies with air. Other instruments are currently used to detect low levels of C3F8 vapour leaking into the N2 environmental gas surrounding the ATLAS silicon tracker. Gas from several parts of the

  11. Measurements and modeling of high-temperature, high-pressure density for binary mixtures of propane with n-decane and propane with n-eicosane

    International Nuclear Information System (INIS)

    Highlights: • High-temperature, high-pressure experimental binary mixture densities of propane with n-decane or n-eicosane are reported. • Tait equation parameters to correlate experimental mixture densities are reported. • EoS give better representation of (propane + decane) system than (propane + eicosane) system. • Reports predictions with PC-SAFT, Peng–Robinson (PR), and volume-translated PR EoS. - Abstract: Binary mixture density data are reported for propane (C3) with n-decane (C10) and with n-eicosane (C20) at T = (320 to 525) K and pressures to 265 MPa. The (C3 + C10) mixture density data are in good agreement with available literature data to 70 MPa, which is the maximum reported literature pressure. There are no available binary mixture density data to compare to the (C3 + C20) mixture density data reported in the present study. The mixture density data are correlated with the Tait equation to facilitate interpolation of the data at different experimental conditions. Equations of state that are suitable for reservoir simulations are used to model the reported data. These models include the Peng–Robinson equation of state (PREoS), a volume-translated PREoS fit to high temperature, high pressure (HTHP) pure component density data, the PC-SAFT EoS, and modifications of the PC-SAFT EoS developed for better representation of HTHP data. The models give superior density predictions for (C3 + C10) mixtures compared to (C3 + C20) mixtures

  12. Effect of noble gas mixtures on the performance of regenerative-type cryocoolers analytical estimate

    Science.gov (United States)

    Daney, D. E.

    1990-09-01

    The performance of regenerators that use noble gas mixtures is compared to the performance of those that use pure helium gas. Both helium-argon and helium-krypton mixtures are investigated. For some heat transfer surfaces, a modest gain in heat transfer can be achieved with these mixtures. The concomitant increase in pressure drop, however, more than offsets the heat transfer gain so the net regenerator loss increases for all evaluated cases. The dependence of heat transfer on Prandtl number (Pr) was not measured for the range associated with noble gas mixtures, 0.2 less than Pr less than 0.5, and it is estimated that the uncertainty from the source can exceed 20 percent. The estimates for the transport properties (Prandtl number, viscosity, and thermal conductivity) of helium-argon and helium-krypton mixtures because of the absence of experimental data at low temperature are given.

  13. 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.

  14. 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. PMID:25847105

  15. Wetting transition and pretransitional thin films in binary liquids: alcohol/perfluoromethylcyclohexane mixtures studied by x-ray reflectivity

    International Nuclear Information System (INIS)

    In this study the wetting transition at the liquid-vapour interface of binary organic liquid mixtures has been investigated by x-ray reflectivity. Mixtures of various isomeric alcohols with perfluoromethylcyclohexane (PFMC) served as model systems, with alcohol carbon numbers ranging from 1 to 4. Remarkably different pretransitional behaviour of the thin films below the wetting temperature was observed, which could be classified according to the carbon number. At two-phase coexistence, no pretransitional thin films could be detected for methanol and ethanol, whereas thin-to-thick-film transitions were found for propanol and butanol and their isomers. For 1-propanol and 2-propanol, the surface of the upper, alcohol-rich phase of the gravity-separated mixture displays a wetting transition at Tw = 31.5 deg. C and 38.3 deg. C, respectively, where the thickness of a PFMC-rich film jumps from less than 25 A to values exceeding the experimental resolution of about 1200 A. For 1-butanol, 2-butanol and i-butanol, we found pretransitional film thicknesses increasing up to 100 A, with wetting transitions at Tw = 45.0 deg. C, 34.2 deg. C and 40.1 deg. C, respectively. In the single-phase region, the study of adsorption isotherms above Tw revealed novel behaviour of the adsorbed PFMC-rich film. We observed both a growing film thickness and a significantly changing composition as the coexistence line was approached. Nevertheless, the variation of the excess adsorption with distance from coexistence could still be described by a power law. (author)

  16. Initiation of unconfined gas detonations in hydrocarbon-air mixtures by a sympathetic mechanism

    International Nuclear Information System (INIS)

    The considered investigation is concerned with the study of the factors which influence detonation propagation in a gas of heterogeneous composition. The conducted experiments assess the ability of a blast wave, emerging from a donor gas detonation and crossing an air gap, to initiate detonation in a second, similar, acceptor gas mixture. Stoichiometric mixtures of both ethylene-air and propane-air are found to exhibit 'sympathetic' gas detonation only across small air gaps. Conditions critical to sympathetic gas detonation agree with predictions of a simple theory taking account of the net shock decay occurring across two acoustic interfaces bounded by an air gap. Sympathetic detonation occurs only if the strength of the shock upon entering the acceptor exceeds a threshold value for the particular gas mixture. Reinitiation of detonation is not satisfactorily explained by planar blast wave decay and autoignition considerations

  17. Application of Gas Dynamical Friction for Planetesimals: II. Evolution of Binary Planetesimals

    CERN Document Server

    Grishin, Evgeni

    2015-01-01

    One of first the stages of planet formation is the growth of small planetesimals and their accumulation into large planetesimals and planetary embryos. This early stage occurs much before the dispersal of most of the gas from the protoplanetary disk. At this stage gas-planetesimal interactions play a key role in the dynamical evolution of \\emph{single} intermediate-mass planetesimals ($m_{p}\\sim10^{21}-10^{25}g$) \\emph{through gas dynamical friction} (GDF). A significant fraction of all Solar system planetesimals (asteroids and Kuiper-belt objects) are known to be binary planetesimals (BPs). Here, we explore the effects of GDF on the evolution of \\emph{binary} planetesimals embedded in a gaseous disk using an N-body code with a fiducial external force accounting for GDF. We find that GDF can induce binary mergers on timescales shorter than the disk lifetime for masses above $m_{p}\\gtrsim10^{22}g$ at 1AU, independent of the binary initial separation and eccentricity. Such mergers can affect the structure of me...

  18. 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.

  19. Apparatus for separating a liquid carried along in a gas-liquid mixture

    International Nuclear Information System (INIS)

    The invention concerns an apparatus for separating a liquid entrained in a gas and liquid mixture and, in particular, the separators for removing the moisture entrained in the saturated steam of nuclear steam generators

  20. Two-dimensional Turbulence in Symmetric Binary-Fluid Mixtures: Coarsening Arrest by the Inverse Cascade

    CERN Document Server

    Perlekar, Prasad; Pandit, Rahul

    2015-01-01

    We study two-dimensional (2D) binary-fluid turbulence by carrying out an extensive direct numerical simulation (DNS) of the forced, statistically steady turbulence in the coupled Cahn-Hilliard and Navier-Stokes equations. In the absence of any coupling, we choose parameters that lead (a) to spinodal decomposition and domain growth, which is characterized by the spatiotemporal evolution of the Cahn-Hilliard order parameter $\\phi$, and (b) the formation of an inverse-energy-cascade regime in the energy spectrum $E(k)$, in which energy cascades towards wave numbers $k$ that are smaller than the energy-injection scale $k_{inj}$ in the turbulent fluid. We show that the Cahn-Hilliard-Navier-Stokes coupling leads to an arrest of phase separation at a length scale $L_c$, which we evaluate from $S(k)$, the spectrum of the fluctuations of $\\phi$. We demonstrate that (a) $L_c \\sim L_H$, the Hinze scale that follows from balancing inertial and interfacial-tension forces, and (b) $L_c$ is independent, within error bars, o...