Mathematical Modeling of Nonstationary Separation Processes in Gas Centrifuge Cascade for Separation of Multicomponent Isotope Mixtures

Directory of Open Access Journals (Sweden)

Orlov Alexey

2016-01-01

Full Text Available This article presents results of development of the mathematical model of nonstationary separation processes occurring in gas centrifuge cascades for separation of multicomponent isotope mixtures. This model was used for the calculation parameters of gas centrifuge cascade for separation of germanium isotopes. Comparison of obtained values with results of other authors revealed that developed mathematical model is adequate to describe nonstationary separation processes in gas centrifuge cascades for separation of multicomponent isotope mixtures.

Analysis of Multicomponent Adsorption Close to a Dew Point

DEFF Research Database (Denmark)

Shapiro, Alexander; Stenby, Erling Halfdan

1998-01-01

We develop the potential theory of multicomponent adsorption close to a dew point. The approach is based on an asymptotic adsorption equation (AAE) which is valid in a vicinity of the dew point. By this equation the thickness of the liquid film is expressed through thermodynamic characteristics...... and the direct calculations, even if the mixture is not close to a dew point.Key Words: adsorption; potential theory; multicomponent; dew point....

Current state in adsorption from multicomponent solutions of nonelectrolytes on solids

International Nuclear Information System (INIS)

Borowko, M.; Jaroniec, M.

1983-01-01

This paper surveys the research carried out on the adsorption from multicomponent liquid mixtures of nonelectrolytes on solids with emphasis on the work performed by the authors. The consistent theoretical treatment of adsorption from concentrated and dilute multicomponent solutions and its application to the liquid adsorption chromatography with the mixed mobile phase are presented. This treatment involved nonideality of the bulk and surface phases, energetic heterogeneity of the adsorbent surface and it may be extended to multilayer adsorption from solutions. The multicomponent liquid/solid adsorption systems, studied experimentally, are reviewed. Many of them have been examined by means of the equations derived for liquid adsorption on heterogeneous surfaces. These studies are summarized in this paper. Moreover, the model studies illustrating the influence of solution nonideality and adsorbent heterogeneity on the excess adsorption isotherms and the distribution coefficient are discussed. (orig.)

Design of advanced multicomponent ferroelectric liquid crystalline mixtures with submicrometre helical pitch

Czech Academy of Sciences Publication Activity Database

Kurp, K.; Czerwiński, M.; Tykarska, M.; Bubnov, Alexej

2017-01-01

Roč. 44, č. 4 (2017), s. 748-756 ISSN 0267-8292 R&D Projects: GA MŠk 7AMB13PL041; GA MŠk(CZ) LD14007; GA ČR GA15-02843S Grant - others:COST Association EU(XE) COST Action IC1208 Institutional support: RVO:68378271 Keywords : ferroelectric liquid crystal * self-assembling materials * submicrometre helical pitch * room temperature mixture * switching time Subject RIV: JJ - Other Materials OBOR OECD: Nano-materials (production and properties) Impact factor: 2.661, year: 2016

Formulation of electroclinic, ferroelectric and antiferroelectric liquid crystal mixtures suitable for display devices

Science.gov (United States)

Debnath, Asim; Goswami, Debarghya; Mandal, Pradip Kumar

2018-04-01

Most of the liquid crystal display (LCD) devices starting from simplest wrist watches or calculators to complex laptops or flat TV sets are based on nematics. Although a tremendous improvement in the quality of display as well as reduction of manufacturing cost has taken place over the years, there are many issues which the LC industry is trying hard to address. Ferroelectric liquid crystals (FLC) are of current interest in the LCD industry since among various other advantages FLC based displays have micro-second order switching compared to milli-second order switching in nematic based displays. To meet the market demand much effort has been made to optimize the physical parameters of FLCs, such as temperature range, spontaneous polarization (PS), helical pitch (p), switching time (τ), tilt angle (θ) and rotational viscosity (γ). Multicomponent mixtures are, therefore, formulated to optimize all the required properties for practical applications since no single FLC compound can satisfy the above requirements. To the best of our knowledge electroclinic, ferroelectric and antiferroelectric liquid crystal mixtures have been formulated first time by any Indian group which have properties suitable for FLC based display devices and at par with mixtures used in the industry.

The elimination of singularities in pair correlation functions of a multicomponent liquid system

International Nuclear Information System (INIS)

Vasil'jev, O.M.; Chalij, O.V.

2004-01-01

In this paper we propose a method that allows to find nonsingular expressions for pair correlation functions of a multicomponent liquid system. The nature of the method deals with using integral and differential Ornstein-Zernike equations for finding asymptotic expressions for pair correlation functions and their subsequent precision. The obtained results are analyzed taking into account their possible applicability for studying the correlative behaviour of multicomponent liquid systems

Experimental and theoretical studies on subcooled flow boiling of pure liquids and multicomponent mixtures

Energy Technology Data Exchange (ETDEWEB)

Jamialahmadi, M.; Abdollahi, H.; Shariati, A. [The University of Petroleum Industry, Ahwaz (Iran); Mueller-Steinhagen, H. [Institute of Technical Thermodynamics, German Aerospace Center (Germany); Institute of Thermodynamics and Thermal Engineering, University of Stuttgart (Germany)

2008-05-15

To improve the design of modern industrial reboilers, accurate knowledge of boiling heat transfer coefficients is essential. In this study flow boiling heat transfer coefficients for binary and ternary mixtures of acetone, isopropanol and water were measured over a wide range of heat flux, subcooling, flow velocity and composition. The measurements cover the regimes of convective heat transfer, transitional boiling and fully developed subcooled flow boiling. Two models are presented for the prediction of flow boiling heat transfer coefficients. The first model is the combination of the Chen model with the Gorenflo correlation and the Schluender model for single and multicomponent boiling, respectively. This model predicts flow boiling heat transfer coefficients with acceptable accuracy, but fails to predict the nucleate boiling fraction NBF reasonably well. The second model is based on the asymptotic addition of forced convective and nucleate boiling heat transfer coefficients. The benefit of this model is a further improvement in the accuracy of flow boiling heat transfer coefficient over the Chen type model, simplicity and the more realistic prediction of the nucleate boiling fraction NBF. (author)

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

International Nuclear Information System (INIS)

Domanska, Urszula; Marciniak, Malgorzata

2007-01-01

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

Thermodynamics of the multicomponent vapor-liquid equilibrium under capillary pressure difference

DEFF Research Database (Denmark)

Shapiro, Alexander; Stenby, Erling Halfdan

2001-01-01

We discuss the two-phase multicomponent equilibrium, provided that the phase pressures are different due to the action of capillary forces. We prove the two general properties of such an equilibrium, which have previously been known for a single-component case, however, to the best of our knowledge......, not for the multicomponent mixtures. The importance is emphasized on the space of the intensive variables P, T and mu (i), where the laws of capillary equilibrium have a simple geometrical interpretation. We formulate thermodynamic problems specific to such an equilibrium, and outline changes to be introduced to common...... algorithms of flash calculations in order to solve these problems. Sample calculations show large variation of the capillary properties of the mixture in the very neighborhood of the phase envelope and the restrictive role of the spinodal surface as a boundary for possible equilibrium states with different...

Water activity changes of multicomponent food mixture during processing

Directory of Open Access Journals (Sweden)

Jiří Štencl

2004-01-01

Full Text Available Water activity of multicomponent food mixture was analysed and measured. Samples of dry fermented sausages with two different starter cultures (Pediococcus pentosaceus + Staphylococcus carnosus and Staphylococcus carnosus + Staphylococcus xylosus + Lactobacillus farciminis were tested during ripening (21 days and storing (91 days. The basic raw materials were the same for all samples: lean beef meat, lean pork and pork fat in equal parts, nitrite salt mixture (2.5 %, and sugars (1.0 %. The method used for water activity tests was indirect manometric in a static environment. Moisture content of samples was measured using halogen dryer. The course of water activity and moisture content of sausages was variable during ripening and steady during storage. Diagrams showed gradual decrease of both parameters. Mathematical models of water activity and moisture content for storage of dry fermented sausages were developed and statistically verified. The influence of starter cultures was not significant.

Drying of liquid food droplets : enzyme inactivation and multicomponent diffusion

NARCIS (Netherlands)

Meerdink, G.

1993-01-01

In this thesis the drying of liquid food droplets is studied from three different points of view: drying kinetics, enzyme inactivation and multicomponent diffusion. Mathematical models are developed and validated experimentally.

Drying experiments are performed with suspended

Improvement in device performance from a mixture of a liquid crystal and photosensitive acrylic prepolymer with the photoinduced vertical alignment method

Directory of Open Access Journals (Sweden)

Czung-Yu Ho, Fa-Hsin Lin, Yu-Tai Tao and Jiunn-Yih Lee

2011-01-01

Full Text Available In a multicomponent nematic liquid crystal (NLC mixture of a liquid crystal (negative-type NLC and a photosensitive acrylic prepolymer, photopolymerization upon UV irradiation induces the separation of the LC and photosensitive acrylic prepolymer layers, thereby leading to a vertical arrangement of LC molecules. In this study, we propose a simple vertical alignment method for LC molecules, by adding a chiral smectic A (SmA* liquid crystal having homeotropic texture characteristics to an NLC mixture solution. Measurements of electro-optical properties revealed that the addition of the SmA* LC not only strengthened the anchoring force of the copolymer alignment film surface, but also significantly enhanced the contrast ratio (~73%, response time and grayscale switching performance of the device.

The Huber’s Method-based Gas Concentration Reconstruction in Multicomponent Gas Mixtures from Multispectral Laser Measurements under Noise Overshoot Conditions

Directory of Open Access Journals (Sweden)

V. A. Gorodnichev

2016-01-01

Full Text Available Laser gas analysers are the most promising for the rapid quantitative analysis of gaseous air pollution. A laser gas analysis problem is that there are instable results in reconstruction of gas mixture components concentration under real noise in the recorded laser signal. This necessitates using the special processing algorithms. When reconstructing the quantitative composition of multi-component gas mixtures from the multispectral laser measurements are efficiently used methods such as Tikhonov regularization, quasi-solution search, and finding of Bayesian estimators. These methods enable using the single measurement results to determine the quantitative composition of gas mixtures under measurement noise. In remote sensing the stationary gas formations or in laboratory analysis of the previously selected (when the gas mixture is stationary air samples the reconstruction procedures under measurement noise of gas concentrations in multicomponent mixtures can be much simpler. The paper considers a problem of multispectral laser analysis of stationary gas mixtures for which it is possible to conduct a series of measurements. With noise overshoots in the recorded laser signal (and, consequently, overshoots of gas concentrations determined by a single measurement must be used stable (robust estimation techniques for substantial reducing an impact of the overshoots on the estimate of required parameters. The paper proposes the Huber method to determine gas concentrations in multicomponent mixtures under signal overshoot. To estimate the value of Huber parameter and the efficiency of Huber's method to find the stable estimates of gas concentrations in multicomponent stationary mixtures from the laser measurements the mathematical modelling was conducted. Science & Education of the Bauman MSTU 108 The mathematical modelling results show that despite the considerable difference among the errors of the mixture gas components themselves a character of

Continuous electrophoretic purification of individual analytes from multicomponent mixtures.

Science.gov (United States)

McLaren, David G; Chen, David D Y

2004-04-15

Individual analytes can be isolated from multicomponent mixtures and collected in the outlet vial by carrying out electrophoretic purification through a capillary column. Desired analytes are allowed to migrate continuously through the column under the electric field while undesired analytes are confined to the inlet vial by application of a hydrodynamic counter pressure. Using pressure ramping and buffer replenishment techniques, 18% of the total amount present in a bulk sample can be purified when the resolution to the adjacent peak is approximately 3. With a higher resolution, the yield could be further improved. Additionally, by periodically introducing fresh buffer into the sample, changes in pH and conductivity can be mediated, allowing higher purity (>or=99.5%) to be preserved in the collected fractions. With an additional reversed cycle of flow counterbalanced capillary electrophoresis, any individual component in a sample mixture can be purified providing it can be separated in an electrophoresis system.

Multicomponent mixed dopant optimization for rapid screening of polycyclic aromatic hydrocarbons using ultra high performance liquid chromatography coupled to atmospheric pressure photoionization high-resolution mass spectrometry

KAUST Repository

Sioud, Salim

2012-05-04

RATIONALE To enhance the ionization efficiencies in atmospheric pressure photoionization mass spectrometry a dopant with favorable ionization energy such as chlorobenzene is typically used. These dopants are typically toxic and difficult to mix with water-soluble organic solvents. In order to achieve a more efficient and less toxic dopant, a multicomponent mixed dopant was explored. METHODS A multicomponent mixed dopant for non-targeted rapid screening of polycyclic aromatic hydrocarbons (PAHs) was developed and optimized using ultra high performance liquid chromatography (UPLC) coupled to atmospheric pressure photoionization high-resolution mass spectrometry. Various single and multicomponent mixed dopants consisting of ethanol, chlorobenzene, bromobenzene, anisole and toluene were evaluated. RESULTS Fourteen out of eighteen PAHs were successfully separated and detected at low pg/μL levels within 5 min with high mass accuracy ≤4 ppm. The optimal mixed multicomponent dopant consisted of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v %) and it improved the limit of detection (LOD) by 2- to 10-fold for the tested PAHs compared to those obtained with pure chlorobenzene. CONCLUSIONS A novel multicomponent dopant that contains 99% ethanol and 1% mixture of chlorobenzene, bromobenzene and anisole was found to be an effective dopant mixture to ionize PAHs. The developed UPLC multicomponent dopant assisted atmospheric pressure photoionization high-resolution mass spectrometry offered a rapid non targeted screening method for detecting the PAHs at low pg/;μL levels within a 5 min run time with high mass accuracy a;circ4 ppm. Copyright © 2012 John Wiley & Sons, Ltd.

Comparative Study of Gas Reconstruction Robust Methods for Multicomponent Gas Mixtures

Directory of Open Access Journals (Sweden)

V. A. Gorodnichev

2015-01-01

Full Text Available When using laser methods of gas analysis, one of the arising problems is instability in results of defining a quantitative composition of gases under control of multicomponent mixes in the conditions of real noise of measurements. It leads to demand for using the special algorithms to process results of laser measurements.For multicomponent gaseous mixes, when solving a problem of quantitative gas analysis based on the results of multispectral laser measurements, use of methods for solving incorrect mathematical tasks is efficient.If mix is stationary (i.e. there is a possibility for a series of measurements it is possible to use a much simpler method to determine concentration of gases, i.e. the least-squares method based on the minimization of residual function.However, the estimates obtained by the least-squares method are effective if distribution of measurement errors is according to the normal law. In practice, the law of errors distribution is often non-normal, and loss of estimate efficiency achieved by the least-squares method occurs even at a small share of bursts.With bursts available in the measuring signal, it is necessary to use the stationary estimation methods allowing the significantly reduced impact on the estimate of considerable bursts.To estimate an efficiency of the robust methods for defining a quantitative composition of the multicomponent stationary gas mixes from multispectral laser measurements a mathematical simulation was performed. A gas mixture was considered to be stationary, and n measurements (at each wavelength were taken ( n were specified from 2 to 6 to define a quantitative composition of gases in the mixture. Simulation was implemented for gas mixes with the number of components from 4 to 6.Results of mathematical simulation show that the robust estimate based on the residual function ( x  arctg x , allows us, in conditions of the bursts of a variable signal, to reduce significantly the error of

Flow boiling heat transfer coefficients at cryogenic temperatures for multi-component refrigerant mixtures of nitrogen-hydrocarbons

Science.gov (United States)

Ardhapurkar, P. M.; Sridharan, Arunkumar; Atrey, M. D.

2014-01-01

The recuperative heat exchanger governs the overall performance of the mixed refrigerant Joule-Thomson cryocooler. In these heat exchangers, the non-azeotropic refrigerant mixture of nitrogen-hydrocarbons undergoes boiling and condensation simultaneously at cryogenic temperature. Hence, the design of such heat exchanger is crucial. However, due to lack of empirical correlations to predict two-phase heat transfer coefficients of multi-component mixtures at low temperature, the design of such heat exchanger is difficult.

Density and Compressibility of Multicomponent n-Alkane Mixtures up to 463 K and 140 MPa

DEFF Research Database (Denmark)

Regueira, Teresa; Glykioti, Maria-Lito; Stenby, Erling Halfdan

2017-01-01

Density measurements of two ternary alkane mixtures (methane/n-butane/n-decane and methane/n-butane/n-dodecane) and two multicomponent mixtures composed of methane/n-butane/n-octane/n-dodecane/n-hexadecane/n-eicosane were performed in the temperature range from (278.15 to 463.15) K and pressures ......–Redlich–Kwong (SRK), Peng–Robinson (PR), Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT), and Soave-Benedict-Webb-Rubin (Soave-BWR) were used for predicting the experimental density values as well as the excess volumes....... to 140 MPa. The isothermal compressibility values of these mixtures were obtained by differentiation from a Tait-type fitting of experimental densities as a function of temperature and pressure. Excess volume of the studied mixtures was also determined. Four different equations of state, that is, Soave...

Sedimentation dynamics and equilibrium profiles in multicomponent mixtures of colloidal particles

International Nuclear Information System (INIS)

Spruijt, E; Biesheuvel, P M

2014-01-01

In this paper we give a general theoretical framework that describes the sedimentation of multicomponent mixtures of particles with sizes ranging from molecules to macroscopic bodies. Both equilibrium sedimentation profiles and the dynamic process of settling, or its converse, creaming, are modeled. Equilibrium profiles are found to be in perfect agreement with experiments. Our model reconciles two apparently contradicting points of view about buoyancy, thereby resolving a long-lived paradox about the correct choice of the buoyant density. On the one hand, the buoyancy force follows necessarily from the suspension density, as it relates to the hydrostatic pressure gradient. On the other hand, sedimentation profiles of colloidal suspensions can be calculated directly using the fluid density as apparent buoyant density in colloidal systems in sedimentation–diffusion equilibrium (SDE) as a result of balancing gravitational and thermodynamic forces. Surprisingly, this balance also holds in multicomponent mixtures. This analysis resolves the ongoing debate of the correct choice of buoyant density (fluid or suspension): both approaches can be used in their own domain. We present calculations of equilibrium sedimentation profiles and dynamic sedimentation that show the consequences of these insights. In bidisperse mixtures of colloids, particles with a lower mass density than the homogeneous suspension will first cream and then settle, whereas particles with a suspension-matched mass density form transient, bimodal particle distributions during sedimentation, which disappear when equilibrium is reached. In all these cases, the centers of the distributions of the particles with the lowest mass density of the two, regardless of their actual mass, will be located in equilibrium above the so-called isopycnic point, a natural consequence of their hard-sphere interactions. We include these interactions using the Boublik–Mansoori–Carnahan–Starling–Leland (BMCSL

SIMULTANEOUS DETERMINATION OF PARACETAMOL AND IBUPROFENE MIXTURES BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

Directory of Open Access Journals (Sweden)

Sophi Damayanti

2010-06-01

Full Text Available Analytical method for the determination of paracetamol and ibuprofene mixtures has been developed by High Performance Liquid Chromatography using C-18 column and acetinitrile - phosphate buffer pH = 4.5 (75:25 containing 0.075% sodium hexanesulfunate as a mobile phase. The detector was set at 215 nm. Using such conditions, retention time for paracetamol and ibuprofen was 4.89 and 7.11 min, respectively. The recovery for paracetamol and ibuprofen was found to be 101.07± 0.73% and 102.02 ± 1.58%, respectively. The detector limits of the method was 1.30 and 1.60 μg/mL with the relative standard deviation (RSD 0.74 and 1.52% for paracetamol and ibuprofen, respectively.   Keywords: paracetamol, ibuprofen, multi-component, validation, HPLC.

Absorption from multicomponent gas mixtures comparing with Elemir gasoline plant

Energy Technology Data Exchange (ETDEWEB)

Miscevic, D

1970-10-01

A short description and explanation are outlined of all factors which have influence on hydrocarbon absorption from multicomponent gas mixtures. A short review of these different methods for absorption efficiency calculation is given. On the basis of the explained methods, the absorption from one natural gas at the Elemir plant is calculated and the results are given in tabular data. The number of the theoretical plate and L/V ratio for a given recovery of the key component is fixed by the calculation and by a graphical solution. Special attention is given for absorption oil depending on gas flow, pressure, and temperature. A series of diagrams is presented showing required absorption oil at the Elemir plant for given propane recovery, depending on the variables which are mentioned.

The separation of solid and liquid components of mixtures

International Nuclear Information System (INIS)

Hunter, W.M.

1980-01-01

An improved method of separating solid and liquid components of mixtures is described which is particularly suited for use in automated radioimmunoassay systems in the analysis of bound and free fractions. A second liquid, having a density intermediate between those of the solid and liquid components, is delivered to the solid/ liquid mixture to form a discrete layer below the mixture and the solid separates into this lower liquid layer assisted by centrifugal force. The second liquid of intermediate density is an aqueous solution of a highly hydrophilic and electrically non-polar solute, such as an aqueous sucrose solution. Further liquids of intermediate density and progressively higher density may be delivered to form further discrete layers below the initial layer of the second dense liquid. After separation of the solid and liquid components of the mixture, the supernatant liquid component of the original mixture is removed in a controlled and non-turbulent manner. The method is illustrated in radioimmunoassays for platelet β-thromboglobulin and human follicle stimulating hormone. (U.K.)

Separation of a multicomponent mixture by gaseous diffusion: modelization of the enrichment in a capillary - application to a pilot cascade

International Nuclear Information System (INIS)

Doneddu, F.

1982-01-01

Starting from the modelization of gaseous flow in a porous medium (flow in a capillary), we generalize the law of enrichment in an infinite cylindrical capillary, established for an isotropic linear mixture, to a multicomponent mixture. A generalization is given of the notion of separation yields and characteristic pressure classically used for separations of isotropic linear mixtures. We present formulas for diagonalizing the diffusion operator, modelization of a multistage, gaseous diffusion cascade and comparison with the experimental results of a drain cascade (N 2 -SF 6 -UF 6 mixture). [fr

Separation of alcohols from organic liquid mixtures by pervaporation

NARCIS (Netherlands)

Park, Hyun-Chae

1993-01-01

In the chemical industry, distillation is generally the preferred technique to separate a liquid mixture. However some liquid mixtures such as azeotropic mixtures, close-boiling hydrocarbons, and various isomers are difficult to separate by simple distillation. For the separation of these mixtures

Application of the cubic-plus-association equation of state to mixtures with polar chemicals and high pressures

DEFF Research Database (Denmark)

Folas, Georgios; Kontogeorgis, Georgios; Michelsen, Michael Locht

2006-01-01

was given to low pressures and liquid-liquid equilibria. In this work, CPA is applied to two classes of mixtures containing polar chemicals for which high-pressure data are available: acetone-containing systems and dimethyl ether mixtures. They are of both scientific and industrial importance. Moreover, CPA......The cubic-plus-association (CPA) equation of state has been previously applied to vapor-liquid, liquid-liquid, and solid-liquid equilibria of mixtures containing associating compounds (water, alcohols, glycols, acids, amines). Although some high-pressure applications have been presented, emphasis...... to conventional models such as MHV2. Very good results are also obtained for multicomponent vapor-liquid-liquid equilibria for mixtures containing gases, water, and dimethyl ether. Finally, it is shown that high-pressure SLE can be predicted based on interaction parameters obtained from low-pressure SLE data....

Process and apparatus for fractionating close-boiling components of a multi-component system

International Nuclear Information System (INIS)

Tsao, U.

1983-01-01

A process and apparatus are described for the fractionation of close-boiling components of a multi-component system comprising at least two fractionation columns A, B in series having a plurality of equilibrium stages in which the vapor stream from a downstream fractionation column B is compressed by a compressor and passed into a lower portion of a preceding fractionation column A and a liquid bottom stream from any one of said columns except the last is expanded by an orifice sufficiently to convey the resulting liquid-vapor mixture to the upper portion of the next fractionation column B. In a particularly preferred embodiment, the compressed overhead vapor stream is passed in heat transfer relationship to a liquid stream withdrawn from the preceding fractionation column A prior to introduction into the lower portion of such preceding fractionation column A. In one of the claims, the multi-component close-boiling system is a deuterium oxide-water solution. (author)

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

International Nuclear Information System (INIS)

Tamura, Kazuhiro; Li Xiaoli; Li Hengde

2009-01-01

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

Numerical modeling of a vaporizing multicomponent droplet

Science.gov (United States)

Megaridis, C. M.; Sirignano, W. A.

The fundamental processes governing the energy, mass, and momentum exchange between the liquid and gas phases of vaporizing, multicomponent liquid droplets have been investigated. The axisymmetric configuration under consideration consists of an isolated multicomponent droplet vaporizing in a convective environment. The model considers different volatilities of the liquid components, variable liquid properties due to variation of the species concentrations, and non-Fickian multicomponent gaseous diffusion. The bicomponent droplet model was employed to examine the commonly used assumptions of unity Lewis number in the liquid phase and Fickian gaseous diffusion. It is found that the droplet drag coefficients, the vaporization rates, and the related transfer numbers are not influenced by the above assumptions in a significant way.

CO2 Removal from Multi-component Gas Mixtures Utilizing Spiral-Wound Asymmetric Membranes

International Nuclear Information System (INIS)

Said, W.B.; Fahmy, M.F.M.; Gad, F.K.; EI-Aleem, G.A.

2004-01-01

A systematic procedure and a computer program have been developed for simulating the performance of a spiral-wound gas permeate for the CO 2 removal from natural gas and other hydrocarbon streams. The simulation program is based on the approximate multi-component model derived by Qi and Henson(l), in addition to the membrane parameters achieved from the binary simulation program(2) (permeability and selectivity). Applying the multi-component program on the same data used by Qi and Henson to evaluate the deviation of the approximate model from the basic transport model, showing results more accurate than those of the approximate model, and are very close to those of the basic transport model, while requiring significantly less than 1 % of the computation time. The program was successfully applied on the data of Salam gas plant membrane unit at Khalda Petroleum Company, Egypt, for the separation of CO 2 from hydrocarbons in an eight-component mixture to estimate the stage cut, residue, and permeate compositions, and gave results matched with the actual Gas Chromatography Analysis measured by the lab

Mathematical Modeling of Nonstationary Separation Processes in Gas Centrifuge Cascade for Separation of Multicomponent Isotope Mixtures

OpenAIRE

Orlov Alexey; Ushakov Anton; Sovach Victor

2016-01-01

This article presents results of development of the mathematical model of nonstationary separation processes occurring in gas centrifuge cascades for separation of multicomponent isotope mixtures. This model was used for the calculation parameters of gas centrifuge cascade for separation of germanium isotopes. Comparison of obtained values with results of other authors revealed that developed mathematical model is adequate to describe nonstationary separation processes in gas centrifuge casca...

Phase-field modeling of isothermal quasi-incompressible multicomponent liquids

Science.gov (United States)

Tóth, Gyula I.

2016-09-01

In this paper general dynamic equations describing the time evolution of isothermal quasi-incompressible multicomponent liquids are derived in the framework of the classical Ginzburg-Landau theory of first order phase transformations. Based on the fundamental equations of continuum mechanics, a general convection-diffusion dynamics is set up first for compressible liquids. The constitutive relations for the diffusion fluxes and the capillary stress are determined in the framework of gradient theories. Next the general definition of incompressibility is given, which is taken into account in the derivation by using the Lagrange multiplier method. To validate the theory, the dynamic equations are solved numerically for the quaternary quasi-incompressible Cahn-Hilliard system. It is demonstrated that variable density (i) has no effect on equilibrium (in case of a suitably constructed free energy functional) and (ii) can influence nonequilibrium pattern formation significantly.

Ternary and quaternary (liquid + liquid) equilibria for (water + ethanol + α-pinene, +β-pinene, or +limonene) and (water + ethanol + α-pinene + limonene) at the temperature 298.15 K

International Nuclear Information System (INIS)

Li Hengde; Tamura, Kazuhiro

2006-01-01

(Liquid + liquid) equilibria and tie-lines for the ternary (water + ethanol + α-pinene, or β-pinene or limonene) and quaternary (water + ethanol + α-pinene + limonene) mixtures have been measured at T = 298.15 K. The experimental multicomponent (liquid + liquid) equilibrium data have been successfully represented in terms of the modified UNIQUAC model with binary parameters

Mathematical model of nonstationary hydraulic processes in gas centrifuge cascade for separation of multicomponent isotope mixtures

OpenAIRE

Orlov, Aleksey Alekseevich; Ushakov, Anton; Sovach, Victor

2017-01-01

The article presents results of development of a mathematical model of nonstationary hydraulic processes in gas centrifuge cascade for separation of multicomponent isotope mixtures. This model was used for the calculation parameters of gas centrifuge cascade for separation of silicon isotopes. Comparison of obtained values with results of other authors revealed that developed mathematical model is adequate to describe nonstationary hydraulic processes in gas centrifuge cascades for separation...

High Pressure Multicomponent Adsorption in Porous Media

DEFF Research Database (Denmark)

Shapiro, Alexander; Stenby, Erling Halfdan

1999-01-01

We analyse adsorption of a multicomponent mixture at high pressure on the basis of the potential theory of adsorption. The adsorbate is considered as a segregated mixture in the external field produced by a solid adsorbent. we derive an analytical equation for the thickness of a multicomponent fi...... close to a dew point. This equation (asymptotic adsorption equation, AAE) is a first order approximation with regard to the distance from a phase envelope....

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

NARCIS (Netherlands)

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

2006-01-01

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

Phase behavior of multicomponent membranes: Experimental and computational techniques

DEFF Research Database (Denmark)

Bagatolli, Luis; Kumar, P.B. Sunil

2009-01-01

Recent developments in biology seems to indicate that the Fluid Mosaic model of membrane proposed by Singer and Nicolson, with lipid bilayer functioning only as medium to support protein machinery, may be too simple to be realistic. Many protein functions are now known to depend on the compositio....... This review includes basic foundations on membrane model systems and experimental approaches applied in the membrane research area, stressing on recent advances in the experimental and computational techniques....... membranes. Current increase in interest in the domain formation in multicomponent membranes also stems from the experiments demonstrating liquid ordered-liquid disordered coexistence in mixtures of lipids and cholesterol and the success of several computational models in predicting their behavior...

Generalized modeling of multi-component vaporization/condensation phenomena for multi-phase-flow analysis

International Nuclear Information System (INIS)

Morita, K.; Fukuda, K.; Tobita, Y.; Kondo, Sa.; Suzuki, T.; Maschek, W.

2003-01-01

A new multi-component vaporization/condensation (V/C) model was developed to provide a generalized model for safety analysis codes of liquid metal cooled reactors (LMRs). These codes simulate thermal-hydraulic phenomena of multi-phase, multi-component flows, which is essential to investigate core disruptive accidents of LMRs such as fast breeder reactors and accelerator driven systems. The developed model characterizes the V/C processes associated with phase transition by employing heat transfer and mass-diffusion limited models for analyses of relatively short-time-scale multi-phase, multi-component hydraulic problems, among which vaporization and condensation, or simultaneous heat and mass transfer, play an important role. The heat transfer limited model describes the non-equilibrium phase transition processes occurring at interfaces, while the mass-diffusion limited model is employed to represent effects of non-condensable gases and multi-component mixture on V/C processes. Verification of the model and method employed in the multi-component V/C model of a multi-phase flow code was performed successfully by analyzing a series of multi-bubble condensation experiments. The applicability of the model to the accident analysis of LMRs is also discussed by comparison between steam and metallic vapor systems. (orig.)

Potential Theory of Multicomponent Adsorption

DEFF Research Database (Denmark)

Shapiro, Alexander; Stenby, Erling Halfdan

1998-01-01

We developed a theory of multicomponent adsorption on the basis of the potential concept originally suggested by Polanyi. The mixture is considered as a heterogeneous substance segregated in the external field emitted by the adsorbent. The same standard equation of state, with no additional fitting...... parameters, is used for the segregated and for the bulk phases. With this approach, few parameters are needed to correlate pure component adsorption isotherms. These parameters may be used to predict adsorption equilibria of multicomponent mixtures without additional adjustment. A connection between...... the potential theory and the spreading pressure concept is established, and problems of the theory consistency are studied. Numerical algorithms are suggested for evaluation of the segregated state of the mixture in the potential field of adsorption forces. Comparison with experimental data shows good agreement...

Prediction of vapour-liquid and vapour-liquid-liquid equilibria of nitrogen-hydrocarbon mixtures used in J-T refrigerators

Science.gov (United States)

Narayanan, Vineed; Venkatarathnam, G.

2018-03-01

Nitrogen-hydrocarbon mixtures are widely used as refrigerants in J-T refrigerators operating with mixtures, as well as in natural gas liquefiers. The Peng-Robinson equation of state has traditionally been used to simulate the above cryogenic process. Multi parameter Helmholtz energy equations are now preferred for determining the properties of natural gas. They have, however, been used only to predict vapour-liquid equilibria, and not vapour-liquid-liquid equilibria that can occur in mixtures used in cryogenic mixed refrigerant processes. In this paper the vapour-liquid equilibrium of binary mixtures of nitrogen-methane, nitrogen-ethane, nitrogen-propane, nitrogen-isobutane and three component mixtures of nitrogen-methane-ethane and nitrogen-methane-propane have been studied with the Peng-Robinson and the Helmholtz energy equations of state of NIST REFPROP and compared with experimental data available in the literature.

Testing the accuracy of correlations for multicomponent mass transport of adsorbed gases in metal-organic frameworks: diffusion of H2/CH4 mixtures in CuBTC.

Science.gov (United States)

Keskin, Seda; Liu, Jinchen; Johnson, J Karl; Sholl, David S

2008-08-05

Mass transport of chemical mixtures in nanoporous materials is important in applications such as membrane separations, but measuring diffusion of mixtures experimentally is challenging. Methods that can predict multicomponent diffusion coefficients from single-component data can be extremely useful if these methods are known to be accurate. We present the first test of a method of this kind for molecules adsorbed in a metal-organic framework (MOF). Specifically, we examine the method proposed by Skoulidas, Sholl, and Krishna (SSK) ( Langmuir, 2003, 19, 7977) by comparing predictions made with this method to molecular simulations of mixture transport of H 2/CH 4 mixtures in CuBTC. These calculations provide the first direct information on mixture transport of any species in a MOF. The predictions of the SSK approach are in good agreement with our direct simulations of binary diffusion, suggesting that this approach may be a powerful one for examining multicomponent diffusion in MOFs. We also use our molecular simulation data to test the ideal adsorbed solution theory method for predicting binary adsorption isotherms and a method for predicting mixture self-diffusion coefficients.

Equivalence of Brownian dynamics and dynamic Monte Carlo simulations in multicomponent colloidal suspensions.

Science.gov (United States)

Cuetos, Alejandro; Patti, Alessandro

2015-08-01

We propose a simple but powerful theoretical framework to quantitatively compare Brownian dynamics (BD) and dynamic Monte Carlo (DMC) simulations of multicomponent colloidal suspensions. By extending our previous study focusing on monodisperse systems of rodlike colloids, here we generalize the formalism described there to multicomponent colloidal mixtures and validate it by investigating the dynamics in isotropic and liquid crystalline phases containing spherical and rodlike particles. In order to investigate the dynamics of multicomponent colloidal systems by DMC simulations, it is key to determine the elementary time step of each species and establish a unique timescale. This is crucial to consistently study the dynamics of colloidal particles with different geometry. By analyzing the mean-square displacement, the orientation autocorrelation functions, and the self part of the van Hove correlation functions, we show that DMC simulation is a very convenient and reliable technique to describe the stochastic dynamics of any multicomponent colloidal system. Our theoretical formalism can be easily extended to any colloidal system containing size and/or shape polydisperse particles.

Efficient Discovery of Novel Multicomponent Mixtures for Hydrogen Storage: A Combined Computational/Experimental Approach

Energy Technology Data Exchange (ETDEWEB)

Wolverton, Christopher [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Ozolins, Vidvuds [Univ. of California, Los Angeles, CA (United States). Dept. of Materials Science and Engineering; Kung, Harold H. [Northwestern Univ., Evanston, IL (United States). Dept. of Chemical and Biological Engineering; Yang, Jun [Ford Scientific Research Lab., Dearborn, MI (United States); Hwang, Sonjong [California Inst. of Technology (CalTech), Pasadena, CA (United States). Dept. of Chemistry and Chemical Engineering; Shore, Sheldon [The Ohio State Univ., Columbus, OH (United States). Dept. of Chemistry and Biochemistry

2016-11-28

The objective of the proposed program is to discover novel mixed hydrides for hydrogen storage, which enable the DOE 2010 system-level goals. Our goal is to find a material that desorbs 8.5 wt.% H₂ or more at temperatures below 85°C. The research program will combine first-principles calculations of reaction thermodynamics and kinetics with material and catalyst synthesis, testing, and characterization. We will combine materials from distinct categories (e.g., chemical and complex hydrides) to form novel multicomponent reactions. Systems to be studied include mixtures of complex hydrides and chemical hydrides [e.g. LiNH²⁺NH₃BH₃] and nitrogen-hydrogen based borohydrides [e.g. Al(BH₄)₃(NH₃)₃]. The 2010 and 2015 FreedomCAR/DOE targets for hydrogen storage systems are very challenging, and cannot be met with existing materials. The vast majority of the work to date has delineated materials into various classes, e.g., complex and metal hydrides, chemical hydrides, and sorbents. However, very recent studies indicate that mixtures of storage materials, particularly mixtures between various classes, hold promise to achieve technological attributes that materials within an individual class cannot reach. Our project involves a systematic, rational approach to designing novel multicomponent mixtures of materials with fast hydrogenation/dehydrogenation kinetics and favorable thermodynamics using a combination of state-of-the-art scientific computing and experimentation. We will use the accurate predictive power of first-principles modeling to understand the thermodynamic and microscopic kinetic processes involved in hydrogen release and uptake and to design new material/catalyst systems with improved properties. Detailed characterization and atomic-scale catalysis experiments will elucidate the effect of dopants and nanoscale catalysts in achieving fast kinetics and reversibility. And

A Variational Statistical-Field Theory for Polar Liquid Mixtures

Science.gov (United States)

Zhuang, Bilin; Wang, Zhen-Gang

Using a variational field-theoretic approach, we derive a molecularly-based theory for polar liquid mixtures. The resulting theory consists of simple algebraic expressions for the free energy of mixing and the dielectric constant as functions of mixture composition. Using only the dielectric constants and the molar volumes of the pure liquid constituents, the theory evaluates the mixture dielectric constants in good agreement with the experimental values for a wide range of liquid mixtures, without using adjustable parameters. In addition, the theory predicts that liquids with similar dielectric constants and molar volumes dissolve well in each other, while sufficient disparity in these parameters result in phase separation. The calculated miscibility map on the dielectric constant-molar volume axes agrees well with known experimental observations for a large number of liquid pairs. Thus the theory provides a quantification for the well-known empirical ``like-dissolves-like'' rule. Bz acknowledges the A-STAR fellowship for the financial support.

Efficient and robust relaxation procedures for multi-component mixtures including phase transition

International Nuclear Information System (INIS)

Han, Ee; Hantke, Maren; Müller, Siegfried

2017-01-01

We consider a thermodynamic consistent multi-component model in multi-dimensions that is a generalization of the classical two-phase flow model of Baer and Nunziato. The exchange of mass, momentum and energy between the phases is described by additional source terms. Typically these terms are handled by relaxation procedures. Available relaxation procedures suffer from efficiency and robustness resulting in very costly computations that in general only allow for one-dimensional computations. Therefore we focus on the development of new efficient and robust numerical methods for relaxation processes. We derive exact procedures to determine mechanical and thermal equilibrium states. Further we introduce a novel iterative method to treat the mass transfer for a three component mixture. All new procedures can be extended to an arbitrary number of inert ideal gases. We prove existence, uniqueness and physical admissibility of the resulting states and convergence of our new procedures. Efficiency and robustness of the procedures are verified by means of numerical computations in one and two space dimensions. - Highlights: • We develop novel relaxation procedures for a generalized, thermodynamically consistent Baer–Nunziato type model. • Exact procedures for mechanical and thermal relaxation procedures avoid artificial parameters. • Existence, uniqueness and physical admissibility of the equilibrium states are proven for special mixtures. • A novel iterative method for mass transfer is introduced for a three component mixture providing a unique and admissible equilibrium state.

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

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...... to the model. In this direction, CPA results were obtained using various approaches, i.e. different association schemes for pure CO2 (assuming that it is a non-associating compound, or that it is a self-associating fluid with two, three or four association sites) and different possibilities for modelling...... mixtures of CO2 with water and alcohols (only use of one interaction parameter kij or assuming cross-association interactions and obtaining the relevant parameters either via a combining rule or using an experimental value for the cross-association energy). It is concluded that CPA is a powerful model...

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

density data for both CO2 and CO2–water and for vapor–liquid equilibrium for mixtures of CO2 with various compounds present in transport systems. In all of these cases we consider various possibilities for modeling CO2 (inert, self-associating using two-, three-, and four sites) and the possibility......The CPA (cubic-plus-association) equation of state is applied in this work to a wide range of systems of relevance to CO2 transport. Both phase equilibria and densities over extensive temperature and pressure ranges are considered. More specifically in this study we first evaluate CPA against......” 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...

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

"Self-Shaping" of Multicomponent Drops.

Science.gov (United States)

Cholakova, Diana; Valkova, Zhulieta; Tcholakova, Slavka; Denkov, Nikolai; Smoukov, Stoyan K

2017-06-13

In our recent study we showed that single-component emulsion drops, stabilized by proper surfactants, can spontaneously break symmetry and transform into various polygonal shapes during cooling [ Denkov Nature 2015 , 528 , 392 - 395 ]. This process involves the formation of a plastic rotator phase of self-assembled oil molecules beneath the drop surface. The plastic phase spontaneously forms a frame of plastic rods at the oil drop perimeter which supports the polygonal shapes. However, most of the common substances used in industry appear as mixtures of molecules rather than pure substances. Here we present a systematic study of the ability of multicomponent emulsion drops to deform upon cooling. The observed trends can be summarized as follows: (1) The general drop-shape evolution for multicomponent drops during cooling is the same as with single-component drops; however, some additional shapes are observed. (2) Preservation of the particle shape upon freezing is possible for alkane mixtures with chain length difference Δn ≤ 4; for greater Δn, phase separation within the droplet is observed. (3) Multicomponent particles prepared from alkanes with Δn ≤ 4 plastify upon cooling due to the formation of a bulk rotator phase within the particles. (4) If a compound, which cannot induce self-shaping when pure, is mixed with a certain amount of a compound which induces self-shaping, then drops prepared from this mixture can also self-shape upon cooling. (5) Self-emulsification phenomena are also observed for multicomponent drops. In addition to the three recently reported mechanisms of self-emulsification [ Tcholakova Nat. Commun. 2017 , ( 8 ), 15012 ], a new (fourth) mechanism is observed upon freezing for alkane mixtures with Δn > 4. It involves disintegration of the particles due to a phase separation of alkanes upon freezing.

Emergence of life from multicomponent mixtures of chemicals: the case for experiments with cycling physicochemical gradients.

Science.gov (United States)

Spitzer, Jan

2013-04-01

The emergence of life from planetary multicomponent mixtures of chemicals is arguably the most complicated and least understood natural phenomenon. The fact that living cells are non-equilibrium systems suggests that life can emerge only from non-equilibrium chemical systems. From an astrobiological standpoint, non-equilibrium chemical systems arise naturally when solar irradiation strikes rotating surfaces of habitable planets: the resulting cycling physicochemical gradients persistently drive planetary chemistries toward "embryonic" living systems and an eventual emergence of life. To better understand the factors that lead to the emergence of life, I argue for cycling non-equilibrium experiments with multicomponent chemical systems designed to represent the evolving chemistry of Hadean Earth ("prebiotic soups"). Specifically, I suggest experimentation with chemical engineering simulators of Hadean Earth to observe and analyze (i) the appearances and phase separations of surface active and polymeric materials as precursors of the first "cell envelopes" (membranes) and (ii) the accumulations, commingling, and co-reactivity of chemicals from atmospheric, oceanic, and terrestrial locations.

Modeling phase equilibria for acid gas mixtures using the CPA equation of state. Part IV. Applications to mixtures of CO2 with alkanes

DEFF Research Database (Denmark)

Tsivintzelis, Ioannis; Ali, Shahid; Kontogeorgis, Georgios

2015-01-01

The thermodynamic properties of pure gaseous, liquid or supercritical CO2 and CO2 mixtures with hydrocarbons and other compounds such as water, alcohols, and glycols are very important in many processes in the oil and gas industry. Design of such processes requires use of accurate thermodynamic...... models, capable of predicting the complex phase behavior of multicomponent mixtures as well as their volumetric properties. In this direction, over the last several years, the cubic-plus-association (CPA) thermodynamic model has been successfully used for describing volumetric properties and phase...

Phase-field simulation of solidification in multicomponent alloys coupled with thermodynamic and diffusion mobility databases

International Nuclear Information System (INIS)

Zhang Ruijie; Jing Tao; Jie Wanqi; Liu Baicheng

2006-01-01

To simulate quantitatively the microstructural evolution in the solidification process of multicomponent alloys, we extend the phase-field model for binary alloys to multicomponent alloys with consideration of the solute interactions between different species. These interactions have a great influence not only on the phase equilibria but also on the solute diffusion behaviors. In the model, the interface region is assumed to be a mixture of solid and liquid with the same chemical potential, but with different compositions. The simulation presented is coupled with thermodynamic and diffusion mobility databases, which can accurately predict the phase equilibria and the solute diffusion transportation in the whole system. The phase equilibria in the interface and other thermodynamic quantities are obtained using Thermo-Calc through the TQ interface. As an example, two-dimensional computations for the dendritic growth in Al-Cu-Mg ternary alloy are performed. The quantitative solute distributions and diffusion matrix are obtained in both solid and liquid phases

The stability and stratification of a quantum liquid mixture

International Nuclear Information System (INIS)

Yukalov, V.I.

1980-01-01

A mixture of quantum liquids was investigated microscopically. The spectrum of collective excitations at finite temperature was determined. The form of the spectrum demonstrates whether there is a stability or stratification of the mixture. The influence of a relative motion of liquids on the spectrum was considered. It was demonstrated that beginning with some finite momentun, the spectrum of each component of the solution splits into two branches, one of which continues the spectrum into the single-particle region. The dynamic susceptibility, the dynamic form-factor, the coefficients of compressibility and the structure factor for the mixture of two Bose liquids were obtained. The integral relations that generalize some rules concerning the binary Bose solution was established. (author)

Predicting diffusivities in dense fluid mixtures

Directory of Open Access Journals (Sweden)

C. DARIVA

1999-09-01

Full Text Available In this work the Enskog solution of the Boltzmann equation, as corrected by Speedy, together with the Weeks-Chandler-Andersen (WCA perturbation theory of liquids is employed in correlating and predicting self-diffusivities of dense fluids. Afterwards this theory is used to estimate mutual diffusion coefficients of solutes at infinite dilution in sub and supercritical solvents. We have also investigated the behavior of Fick diffusion coefficients in the proximity of a binary vapor-liquid critical point since this subject is of great interest for extraction purposes. The approach presented here, which makes use of a density and temperature dependent hard-sphere diameter, is shown to be excellent for predicting diffusivities in dense pure fluids and fluid mixtures. The calculations involved highly nonideal mixtures as well as systems with high molecular asymmetry. The predicted diffusivities are in good agreement with the experimental data for the pure and binary systems. The methodology proposed here makes only use of pure component information and density of mixtures. The simple algebraic relations are proposed without any binary adjustable parameters and can be readily used for estimating diffusivities in multicomponent mixtures.

Pore and surface diffusion in multicomponent adsorption and liquid chromatography systems

International Nuclear Information System (INIS)

Ma, Z.; Whitley, R.D.; Wang, N.H.L.

1996-01-01

A generalized parallel pore and surface diffusion model for multicomponent adsorption and liquid chromatography is formulated and solved numerically. Analytical solution for first- and second-order central moments for a pulse on a plateau input is used as benchmarks for the numerical solutions. Theoretical predictions are compared with experimental data for two systems: ion-exchange of strontium, sodium, and calcium in a zeolite and competitive adsorption of two organics on activated carbon. In a linear isotherm region of single-component systems, both surface and pore diffusion cause symmetric spreading in breakthrough curves. In a highly nonlinear isotherm region, however, surface diffusion causes pronounced tailing in breakthrough curves; the larger the step change in concentration, the more pronounced tailing, in contrast to relatively symmetric breakthroughs due to pore diffusion. If only a single diffusion mechanism is assumed in analyzing the data of parallel diffusion systems, a concentration-dependent apparent surface diffusivity or pore diffusivity results; for a convex isotherm, the apparent surface diffusivity increases, whereas the apparent pore diffusivity decreases with increasing concentration. For a multicomponent nonlinear system, elution order can change if pore diffusion dominates for a low-affinity solute, whereas surface diffusion dominates for a high-affinity solute

Numerical analysis of mass transfer with graphite oxidation in a laminar flow of multi-component gas mixture through a circular tube

International Nuclear Information System (INIS)

Ogawa, Masuro

1992-10-01

In the present paper, mass transfer has been numerically studied in a laminar flow through a circular graphite tube to evaluate graphite corrosion rate and generation rate of carbon monoxide during a pipe rupture accident in a high temperature gas cooled reactor. In the analysis, heterogeneous (graphite oxidation and graphite/carbon dioxide reaction) and homogeneous (carbon monoxide combustion) chemical reactions were dealt in the multi-component gas mixture; helium, oxygen, carbon monoxide and carbon dioxide. Multi-component diffusion coefficients were used in a diffusion term. Mass conservation equations of each gas component, mass conservation equation and momentum conservation equations of the gas mixture were solved by using SIMPLE algorism. Chemical reactions between graphite and oxygen, graphite and carbon dioxide, and carbon monoxide combustion were taken into account in the present numerical analysis. An energy equation for the gas mixture was not solved and temperature was held to be constant in order to understand basic mass transfer characteristics without heat transfer. But, an energy conservation equation for single component gas was added to know heat transfer characteristics without mass transfer. The effects of these chemical reactions on the mass transfer coefficients were quantitatively and qualitatively clarified in the range of 50 to 1000 of inlet Reynolds numbers, 0 to 0.5 of inlet oxygen mass fraction and 800 to 1600degC of temperature. (author)

Aerolization During Boron Nanoparticle Multi-Component Fuel Group Burning Studies

Science.gov (United States)

2014-02-03

overall energy density of the multi-component fuel mixture. Boron nanoparticle- doped multi-component hydrocarbon fuels represent a potential high...addressed, Boron nanoparticle- doped multi-component hydrocarbon fuels represent a potential high-efficiency, tactical fuel that could increase thrust...and micron-sized aluminum particles. Combustion and Flame 158(2): 354-368. Gan, Y., Y. S. Lim, and L. Qiao. 2012. Combustion of nanofluid fuels

Relationship between the partial molar and molar quantity of a thermodynamic state function in a multicomponent mixture – revisited

International Nuclear Information System (INIS)

Näfe, H.

2013-01-01

As far as a multicomponent mixture is concerned, different versions exist in the literature for the relationship between the partial molar and molar quantity of a thermodynamic state function with the most prominent example of the two quantities being the activity coefficient of an arbitrary component and the excess Gibbs free energy of a mixture comprising this component. Since the relationships published so far have to a large degree been derived independently of each other and result from apparently conflicting approaches, they are still considered as separate subjects in the literature. It is demonstrated that despite this curious situation all relationships are equivalent to each other from a mathematical point of view

Form of multicomponent Fickian diffusion coefficients matrix

International Nuclear Information System (INIS)

Wambui Mutoru, J.; Firoozabadi, Abbas

2011-01-01

Highlights: → Irreversible thermodynamics establishes form of multicomponent diffusion coefficients. → Phenomenological coefficients and thermodynamic factors affect sign of diffusion coefficients. → Negative diagonal elements of diffusion coefficients matrix can occur in non-ideal mixtures. → Eigenvalues of the matrix of Fickian diffusion coefficients may not be all real. - Abstract: The form of multicomponent Fickian diffusion coefficients matrix in thermodynamically stable mixtures is established based on the form of phenomenological coefficients and thermodynamic factors. While phenomenological coefficients form a symmetric positive definite matrix, the determinant of thermodynamic factors matrix is positive. As a result, the Fickian diffusion coefficients matrix has a positive determinant, but its elements - including diagonal elements - can be negative. Comprehensive survey of reported diffusion coefficients data for ternary and quaternary mixtures, confirms that invariably the determinant of the Fickian diffusion coefficients matrix is positive.

Phase Behavior of Mixtures of Ionic Liquids and Organic Solvents

DEFF Research Database (Denmark)

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

2010-01-01

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

Non-equilibrium Thermodynamic Dissolution Theory for Multi-Component Solid/Liquid Surfaces Involving Surface Adsorption and Radiolysis Kinetics

International Nuclear Information System (INIS)

Stout, R B

2001-01-01

A theoretical expression is developed for the dissolution rate response for multi-component radioactive materials that have surface adsorption kinetics and radiolysis kinetics when wetted by a multi-component aqueous solution. An application for this type of dissolution response is the performance evaluation of multi-component spent nuclear fuels (SNFs) for long term interim storage and for geological disposition. Typically, SNF compositions depend on initial composition, uranium oxide and metal alloys being most common, and on reactor burnup which results in a wide range of fission product and actinide concentrations that decay by alpha, beta, and gamma radiation. These compositional/burnup ranges of SNFs, whether placed in interim storage or emplaced in a geologic repository, will potentially be wetted by multi-component aqueous solutions, and these solutions may be further altered by radiolytic aqueous species due to three radiation fields. The solid states of the SNFs are not thermodynamically stable when wetted and will dissolve, with or without radiolysis. The following development of a dissolution theory is based on a non-equilibrium thermodynamic analysis of energy reactions and energy transport across a solid-liquid phase change discontinuity that propagates at a quasi-steady, dissolution velocity. The integral form of the energy balance equation is used for this spatial surface discontinuity analysis. The integral formulation contains internal energy functional of classical thermodynamics for both the SNFs' solid state and surface adsorption species, and the adjacent liquid state, which includes radiolytic chemical species. The steady-state concentrations of radiolytic chemical species are expressed by an approximate analysis of the decay radiation transport equation. For purposes of illustration a modified Temkin adsorption isotherm was assumed for the surface adsorption kinetics on an arbitrary, finite area of the solid-liquid dissolution interface. For

Predicting liquid immiscibility in multicomponent nuclear waste glasses

International Nuclear Information System (INIS)

Peeler, D.K.; Hrma, P.R.

1994-04-01

Taylor's model for predicting amorphous phase separation in complex, multicomponent systems has been applied to high-level (simulated) radioactive waste glasses at the US Department of Energy's Hanford site. Taylor's model is primarily based on additions of modifying cations to a Na 2 O-B 2 O 3 -SiO 2 (NBS) submixture of the multicomponent glass. The position of the submixture relative to the miscibility dome defines the development probability of amorphous phase separation. Although prediction of amorphous phase separation in Hanford glasses (via experimental SEM/TEM analysis) is the primary thrust of this work; reported durability data is also provides limited insight into the composition/durability relationship. Using a modified model similar to Taylor's, the results indicate that immiscibility may be predicted for multicomponent waste glasses by the addition of Li 2 O to the ''alkali'' corner of the NBS submixture

Investigation on the structure of liquid N-methylformamide-dimethylsulfoxide mixtures

Energy Technology Data Exchange (ETDEWEB)

Cordeiro, Joao M.M., E-mail: cordeiro@dfq.feis.unesp.br [ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxon OX11 0QX (United Kingdom); Soper, Alan K. [ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxon OX11 0QX (United Kingdom)

2011-03-18

Graphical abstract: Structure of liquid NMF and DMSO mixtures investigated using a combination of neutron diffraction techniques augmented with isotopic substitution and empirical potential structure refinement simulations. Research highlights: {yields} NMF-DMSO mixture is a well-structured liquid. {yields} The liquid structure is driven by strong hydrogen bonds. {yields} There is a preference for NMF-DMSO hydrogen bonding compared to the NMF-NMF. {yields} There are very stable NMF-DMSO dimers dispersed through the liquid. {yields} The peptide structure is very well solvated in DMSO. - Abstract: The structures of liquid mixtures of N-methylformamide (NMF) and dimethyl sulfoxide (DMSO) at two concentrations (80% and 50% NMF) are investigated using a combination of neutron diffraction augmented with isotopic substitution and empirical potential structure refinement simulations. The results indicate that the NMF and DMSO molecules are hydrogen-bonded to one another with a preference for NMF-DMSO hydrogen bonding, compared to the NMF-NMF ones. The liquid is orientationally structured as a consequence of these hydrogen bonds between molecules. NMF-DMSO dimers are very stable species in the bulk of the mixture. The structure of the dimers is such that the angle between the molecular dipole moments is around 60{sup o}. The NMF molecules are well solvated in DMSO with potential implications for peptides solvation in this solvent.

Investigation on the structure of liquid N-methylformamide-dimethylsulfoxide mixtures

International Nuclear Information System (INIS)

Cordeiro, Joao M.M.; Soper, Alan K.

2011-01-01

Graphical abstract: Structure of liquid NMF and DMSO mixtures investigated using a combination of neutron diffraction techniques augmented with isotopic substitution and empirical potential structure refinement simulations. Research highlights: → NMF-DMSO mixture is a well-structured liquid. → The liquid structure is driven by strong hydrogen bonds. → There is a preference for NMF-DMSO hydrogen bonding compared to the NMF-NMF. → There are very stable NMF-DMSO dimers dispersed through the liquid. → The peptide structure is very well solvated in DMSO. - Abstract: The structures of liquid mixtures of N-methylformamide (NMF) and dimethyl sulfoxide (DMSO) at two concentrations (80% and 50% NMF) are investigated using a combination of neutron diffraction augmented with isotopic substitution and empirical potential structure refinement simulations. The results indicate that the NMF and DMSO molecules are hydrogen-bonded to one another with a preference for NMF-DMSO hydrogen bonding, compared to the NMF-NMF ones. The liquid is orientationally structured as a consequence of these hydrogen bonds between molecules. NMF-DMSO dimers are very stable species in the bulk of the mixture. The structure of the dimers is such that the angle between the molecular dipole moments is around 60 o . The NMF molecules are well solvated in DMSO with potential implications for peptides solvation in this solvent.

On the predictive capabilities of CPA for applications in the chemical industry: Mulficomponent mixtures containing methyl-methacrylate, dimethyl-ether or acetic acid

DEFF Research Database (Denmark)

Tsivintzelis, Ioannis; Kontogeorgis, Georgios

2014-01-01

mixtures exhibiting vapor-liquid (VLE) and/or liquid-liquid (LLE) equilibrium. The first two cases include mixtures of methyl-methacrylate with acetone or methanol and dimethyl-ether with ethanol, respectively. In these two cases, the classical form of CPA is used. The third case involves aqueous mixtures...... for the acetic acid-water system for which different parameter sets at different temperatures can be recommended. Even with the use of CPA-HV mixing rules, modeling of the acetic acid-water system with few interaction parameters remains a challenging task. Excellent simultaneous VLE and LLE correlation...... is obtained for complex systems such as aqueous mixtures with ethers and esters. The multicomponent results are, with a few exceptions, very satisfactory, especially for the vapor-liquid equilibrium cases. For the demanding aqueous acetic acid-water containing systems, one parameter set is recommended...

Mathematical Model for Multicomponent Adsorption Equilibria Using Only Pure Component Data

DEFF Research Database (Denmark)

Marcussen, Lis

2000-01-01

A mathematical model for nonideal adsorption equilibria in multicomponent mixtures is developed. It is applied with good results for pure substances and for prediction of strongly nonideal multicomponent equilibria using only pure component data. The model accounts for adsorbent...

Multi-component analysis of tetracyclines, sulfonamides and tylosin in swine manure by liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Jacobsen, Anne Marie; Halling-Sørensen, Bent

2006-03-01

A multi-component method focussing on thorough sample preparation has been developed for simultaneous analysis of swine manure for three classes of antibiotic-tetracyclines, sulfonamides, and tylosin. Liquid manure was initially freeze-dried and homogenised by pulverization before extraction by pressurised liquid extraction. The extraction was performed at 75 degrees C and 2,500 psig in three steps using two cycles with 0.2 mol L(-1) citric acid buffer (pH 4.7) and one cycle with a mixture of 80% methanol with 0.2 mol L(-1) citric acid (pH 3). After liquid-liquid extraction with heptane to remove lipids, the pH of the manure was adjusted to 3 with formic acid and the sample was vacuum-filtered through 0.6 mum glass-fibre filters. Finally the samples were pre-concentrated by tandem SPE (SAX-HLB). Recoveries were determined for manure samples spiked at three concentrations (50-5,000 microg kg(-1) dry matter); quantification was achieved by matrix-matched calibration. Recoveries were >70% except for oxytetracycline (42-54%), sulfadiazine (59-73%), and tylosin (9-35%) and did not vary with concentration or from day-to-day. Limits of quantification (LOQ) for all compounds, determined as a signal-to-noise ratio of 10, were in the range 10-100 microg kg(-1) dry matter. The suitability of the method was assessed by analysis of swine manure samples from six different pig-production sites, e.g. finishing pigs, sows, or mixed production. Residues of antibiotics were detected in all samples. The largest amounts were found for tetracyclines (up to 30 mg kg(-1) dry matter for the sum of CTC and ECTC). Sulfonamides were detected at concentrations up to 2 mg kg(-1) dry matter (SDZ); tylosin was not detected in any samples.

Predicting liquid immiscibility in multicomponent nuclear waste glasses

International Nuclear Information System (INIS)

Peeler, D.K.; Hrma, P.R.

1994-01-01

Taylor's model for predicting amorphous phase separation in complex, multicomponent systems has been applied to high-level (simulated) radioactive waste glasses at the U.S. Department of Energy's Hanford site. Taylor's model is primarily based on additions of modifying cations to a Na 2 O-B 2 O 3 -SiO 2 (NBS) submixture of the multicomponent glass. The position of the submixture relative to the immiscibility dome defines the development probability of amorphous phase separation. Although prediction of amorphous phase separation in Hanford glasses (via experimental SEM/TEM analysis) is the primary thrust of this work; reported durability data is also provides limited insight into the composition/durability relationship. Using a modified model similar to Taylor's, the results indicate that immiscibility may be predicted for multicomponent waste glasses by the addition of Li 2 O to the open-quotes alkaliclose quotes corner of the NBS submixture

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

Science.gov (United States)

Cha, Seoncheol; Kim, Doseok

2018-05-01

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

Simplified simulation of multicomponent isotope separation by gas centrifuge

International Nuclear Information System (INIS)

Guo Zhixiong; Ying Chuntong

1995-01-01

The expressions of diffusion equation for multicomponent isotope separation by gas centrifuge are derived by utilizing the simplified diffusion transport vector. A method of radial averaging which was restricted to a binary mixture is extended to multicomponent isotope mixtures by using an iterative scheme. A numerical analysis of tetradic UF 6 or SF 6 gas isotope separation by centrifuge is discussed when a special model of velocity distribution is given. The dependence of mutual separation factor for the components on their molecular weights' difference is obtained. Some aspects of the given model of gas fluid are also discussed

The Viscosity of Organic Liquid Mixtures

Science.gov (United States)

Len, C. W.; Trusler, J. P. M.; Vesovic, V.; Wakeham, W. A.

2006-01-01

The paper reports measurements of the viscosity and density of two heavy hydrocarbon mixtures, Dutrex and Arab Light Flashed Distillate (ALFD), and of their mixtures with hydrogen. The measurements have been carried out with a vibrating-wire device over a range of temperatures from 399 to 547 K and at pressures up to 20 MPa. Measurements have also been carried out on systems in which hydrogen at different concentrations has been dissolved in the liquids. The measurements have an estimated uncertainty of ±5% for viscosity and ±2% for density and represent the first results on these prototypical heavy hydrocarbons. The results reveal that the addition of hydrogen reduces both the density and viscosity of the original hydrocarbon mixture at a particular temperature and pressure.

Quantum statistics and liquid helium 3 - helum 4 mixtures

International Nuclear Information System (INIS)

Cohen, E.G.D.

1979-01-01

The behaviour of liquid helium 3-helium 4 mixtures is considered from the point of view of manifestation of quantum statistics effects in macrophysics. The Boze=Einstein statistics is shown to be of great importance for understanding superfluid helium-4 properties whereas the Fermi-Dirac statistics is of importance for understanding helium-3 properties. Without taking into consideration the interaction between the helium atoms it is impossible to understand the basic properties of liquid helium 33 - helium 4 mixtures at constant pressure. Proposed is a simple model of the liquid helium 3-helium 4 mixture, namely the binary mixture consisting of solid spheres of two types subjecting to the Fermi-Dirac and Bose-Einstein statistics relatively. This model predicts correctly the most surprising peculiarities of phase diagrams of concentration dependence on temperature for helium solutions. In particular, the helium 4 Bose-Einstein statistics is responsible for the phase lamination of helium solutions at low temperatures. It starts in the peculiar critical point. The helium 4 Fermi-Dirac statistics results in incomplete phase lamination close to the absolute zero temperatures, that permits operation of a powerful cooling facility, namely refrigerating machine on helium solution

Experimental measurements and prediction of liquid densities for n-alkane mixtures

International Nuclear Information System (INIS)

Ramos-Estrada, Mariana; Iglesias-Silva, Gustavo A.; Hall, Kenneth R.

2006-01-01

We present experimental liquid densities for n-pentane, n-hexane and n-heptane and their binary mixtures from (273.15 to 363.15) K over the entire composition range (for the mixtures) at atmospheric pressure. A vibrating tube densimeter produces the experimental densities. Also, we present a generalized correlation to predict the liquid densities of n-alkanes and their mixtures. We have combined the principle of congruence with the Tait equation to obtain an equation that uses as variables: temperature, pressure and the equivalent carbon number of the mixture. Also, we present a generalized correlation for the atmospheric liquid densities of n-alkanes. The average absolute percentage deviation of this equation from the literature experimental density values is 0.26%. The Tait equation has an average percentage deviation of 0.15% from experimental density measurements

Multicomponent quantitative spectroscopic analysis without reference substances based on ICA modelling.

Science.gov (United States)

Monakhova, Yulia B; Mushtakova, Svetlana P

2017-05-01

A fast and reliable spectroscopic method for multicomponent quantitative analysis of targeted compounds with overlapping signals in complex mixtures has been established. The innovative analytical approach is based on the preliminary chemometric extraction of qualitative and quantitative information from UV-vis and IR spectral profiles of a calibration system using independent component analysis (ICA). Using this quantitative model and ICA resolution results of spectral profiling of "unknown" model mixtures, the absolute analyte concentrations in multicomponent mixtures and authentic samples were then calculated without reference solutions. Good recoveries generally between 95% and 105% were obtained. The method can be applied to any spectroscopic data that obey the Beer-Lambert-Bouguer law. The proposed method was tested on analysis of vitamins and caffeine in energy drinks and aromatic hydrocarbons in motor fuel with 10% error. The results demonstrated that the proposed method is a promising tool for rapid simultaneous multicomponent analysis in the case of spectral overlap and the absence/inaccessibility of reference materials.

Dynamics of coarsening in multicomponent lipid vesicles with non-uniform mechanical properties

Science.gov (United States)

Funkhouser, Chloe M.; Solis, Francisco J.; Thornton, K.

2014-04-01

Multicomponent lipid vesicles are commonly used as a model system for the complex plasma membrane. One phenomenon that is studied using such model systems is phase separation. Vesicles composed of simple lipid mixtures can phase-separate into liquid-ordered and liquid-disordered phases, and since these phases can have different mechanical properties, this separation can lead to changes in the shape of the vesicle. In this work, we investigate the dynamics of phase separation in multicomponent lipid vesicles, using a model that couples composition to mechanical properties such as bending rigidity and spontaneous curvature. The model allows the vesicle surface to deform while conserving surface area and composition. For vesicles initialized as spheres, we study the effects of phase fraction and spontaneous curvature. We additionally initialize two systems with elongated, spheroidal shapes. Dynamic behavior is contrasted in systems where only one phase has a spontaneous curvature similar to the overall vesicle surface curvature and systems where the spontaneous curvatures of both phases are similar to the overall curvature. The bending energy contribution is typically found to slow the dynamics by stabilizing configurations with multiple domains. Such multiple-domain configurations are found more often in vesicles with spheroidal shapes than in nearly spherical vesicles.

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Boiling of multicomponent working fluids used in refrigeration and cryogenic systems

Science.gov (United States)

Mogorychny, V. I.; Dolzhikov, A. S.

2017-11-01

Working fluids based on mixtures are widely used in cryogenic and refrigeration engineering. One of the main elements of low-temperature units is a recuperative heat exchanger where the return flow cools the direct (cold regeneration is carrying out) resulting in continuous boiling and condensation of the multicomponent working fluid in the channels. The temperature difference between the inlet and outlet of the heat exchanger can be more than 100K, which leads to a strong change in thermophysical properties along its length. In addition, the fraction of the liquid and vapor phases in the flow varies very much, which affects the observed flow regimes in the heat exchanger channels. At the moment there are not so many experimental data and analytical correlations that would allow to estimate the heat transfer coefficient during the flow of a two-phase mixture flow at low temperatures. The work is devoted to the study of the boiling process of multicomponent working fluids used in refrigeration and cryogenic engineering. The description of the method of determination of heat transfer coefficient during boiling of mixtures in horizontal heated channel is given as well as the design of the experimental stand allowing to make such measurements. This stand is designed on the basis of a refrigeration unit operating on the Joule-Thomson throttle cycle and makes it possible to measure the heat transfer coefficient with a good accuracy. Also, the calculated values of the heat transfer coefficient, obtained with the use of various correlations, are compared with the existing experimental data. Knowing of the heat transfer coefficient will be very useful in the design of heat exchangers for low-temperature units operating on a mixture refrigerant.

Algorithms for GPU-based molecular dynamics simulations of complex fluids: Applications to water, mixtures, and liquid crystals.

Science.gov (United States)

Kazachenko, Sergey; Giovinazzo, Mark; Hall, Kyle Wm; Cann, Natalie M

2015-09-15

A custom code for molecular dynamics simulations has been designed to run on CUDA-enabled NVIDIA graphics processing units (GPUs). The double-precision code simulates multicomponent fluids, with intramolecular and intermolecular forces, coarse-grained and atomistic models, holonomic constraints, Nosé-Hoover thermostats, and the generation of distribution functions. Algorithms to compute Lennard-Jones and Gay-Berne interactions, and the electrostatic force using Ewald summations, are discussed. A neighbor list is introduced to improve scaling with respect to system size. Three test systems are examined: SPC/E water; an n-hexane/2-propanol mixture; and a liquid crystal mesogen, 2-(4-butyloxyphenyl)-5-octyloxypyrimidine. Code performance is analyzed for each system. With one GPU, a 33-119 fold increase in performance is achieved compared with the serial code while the use of two GPUs leads to a 69-287 fold improvement and three GPUs yield a 101-377 fold speedup. © 2015 Wiley Periodicals, Inc.

Non-linearity parameter of binary liquid mixtures at elevated pressures

Indian Academy of Sciences (India)

. Ultrasonic studies in liquid mixtures provide valuable information about structure and interaction in such systems. The present investigation comprises of theoretical evaluation of the acoustic non-linearity parameter / of four binary liquid ...

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.

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

Science.gov (United States)

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

2014-05-15

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

Representation and Validation of Liquid Densities for Pure Compounds and Mixtures

DEFF Research Database (Denmark)

O'Connell, J.; V. Dicky, V.; Abildskov, Jens

Reliable correlation and prediction of liquid densities are important for designing chemical processes at normal and elevated pressures. We have extended a corresponding states model from molecular theory to yield a robust method for quality testing of experimental data that also provides predicted...... values at unmeasured conditions. The model has been shown to successfully validate and represent the pressure and temperature dependence of liquid densities greater than 1.5 of the critical density for pure compounds, binary mixtures, and ternary mixtures from the triple to critical temperatures...... at pressures up to 1000 MPa. The systems include the full range of organic compounds, including complex mixtures, and ionic liquids. Minimal data are required for making predictions.The presentation will show the implementation of the method, criteria for its deployment, examples of its application to a wide...

Ultrafast and ultrasensitive dielectric liquids/mixtures: Basic measurements and applications

International Nuclear Information System (INIS)

Christophorou, L.G.; Faidas, H.; McCorkle, D.L.; Tennessee Univ., Knoxville, TN

1989-01-01

Basic properties of cryogenic and room temperature dielectric liquids/mixtures with high electron yields (under irradiation by ionizing particles) and high excess electron drift velocities are discussed. A number of ultrafast and ultrasensitive liquid media -- appropriate for possible use in liquid-filled radiation detectors and other applications -- are identified. 44 refs., 12 figs

Hydrogen Separation by Natural Zeolite Composite Membranes: Single and Multicomponent Gas Transport.

Science.gov (United States)

Farjoo, Afrooz; Kuznicki, Steve M; Sadrzadeh, Mohtada

2017-10-06

Single and multicomponent gas permeation tests were used to evaluate the performance of metal-supported clinoptilolite membranes. The efficiency of hydrogen separation from lower hydrocarbons (methane, ethane, and ethylene) was studied within the temperature and pressure ranges of 25-600 °C and 110-160 kPa, respectively. The hydrogen separation factor was found to reduce noticeably in the gas mixture compared with single gas experiments at 25 °C. The difference between the single and multicomponent gas results decreased as the temperature increased to higher than 300 °C, which is when the competitive adsorption-diffusion mechanism was replaced by Knudsen diffusion or activated diffusion mechanisms. To evaluate the effect of gas adsorption, the zeolite surface isotherms of each gas in the mixture were obtained from 25 °C to 600 °C. The results indicated negligible adsorption of individual gases at temperatures higher than 300 °C. Increasing the feed pressure resulted in a higher separation efficiency for the individual gases compared with the multicomponent mixture, due to the governing effect of the adsorptive mechanism. This study provides valuable insight into the application of natural zeolites for the separation of hydrogen from a mixture of hydrocarbons.

Evaporation of multicomponent chemical spills: When is liquid phase resistance significant?

International Nuclear Information System (INIS)

Berger, D.; Mackay, D.

1993-01-01

When chemicals are spilled on land or water, it is important to be able to estimate evaporation rates accurately. Conventional models used to predict evaporation rates of multicomponent spills assume that the entire resistance to evaporation lies in the vapor phase. Under certain conditions, an additional liquid phase resistance may be introduced, resulting in retarded evaporation rates. Existing models may thus fail to predict spill behavior accurately. A study is described whose objective is to elucidate the significance of the liquid phase resistance. Evaporation experiments were conducted in which a thin layer of synthetic oil (mineral oil enriched with compounds such as pentane, hexane, toluene, octane, and p-xylene) was exposed to prolonged evaporation in a metal tray at controlled wind speeds. Bulk samples of the spill layer were taken at specific time intervals and their composition was determined by gas chromatographic analysis. The results are compared to those from a theoretical model and to gas stripping experiments. The model is based on the evaporative flux equation incorporating Raoult's law; inputs are the air-oil partition coefficient for each component and the composition of the synthetic oil on a volume and mole fraction basis. The study has enabled the formation of vertical concentration profiles to be examined and liquid phase mass transfer coefficients to be estimated. The results imply that liquid-phase resistance effects are likely to be important for the most volatile components. Contaminated areas may thus continue to be hazardous, even though model predictions indicate otherwise. 7 refs., 3 figs., 2 tabs

Liquid-liquid extraction of uranium (VI) using Cyanex 272 in kerosene from sodium salicylate medium

International Nuclear Information System (INIS)

Kamble, Pravin N.; Mohite, Baburao S.; Suryavanshi, Vishal J.; Salunkhe, Suresh T.

2015-01-01

Liquid-liquid extraction of uranium (VI) from sodium salicylate media using Cyanex 272 in kerosene has been carried out. Uranium (VI) was quantitatively extracted from 1x10 -4 M sodium salicylate with 5x10 -4 M Cyanex 272 in kerosene. It was stripped quantitatively from the organic phase with 4M HCl and determined spectrophotometrically with arsenazo(III) at 600 nm. The effects of concentrations of sodium salicylate, metal ions and strippants have been studied. Separation of uranium (VI) from other elements was achieved from binary as well as from multicomponent mixtures. The method is simple, rapid and selective with good reproducibility (approximately ±2%). (author)

Ionic liquids for separation of olefin-paraffin mixtures

Science.gov (United States)

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

2013-09-17

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

Phase equilibria for mixtures containing very many components. development and application of continuous thermodynamics for chemical process design

International Nuclear Information System (INIS)

Cotterman, R.L.; Bender, R.; Prausnitz, J.M.

1984-01-01

For some multicomponent mixtures, where detailed chemical analysis is not feasible, the compositio of the mixture may be described by a continuous distribution function of some convenient macroscopic property suc as normal boiling point or molecular weight. To attain a quantitative description of phase equilibria for such mixtures, this work has developed thermodynamic procedures for continuous systems; that procedure is called continuous thermodynamics. To illustrate, continuous thermodynamics is used to calculate dew points for natural-gas mixtures, solvent loss in a high-pressure absorber, and liquid-liquid phase equilibria in a polymer fractionation process. Continuous thermodynamics provides a rational method for calculating phase equilibria for those mixtures where complete chemical analysis is not available but where composition can be given by some statistical description. While continuous thermodynamics is only the logical limit of the well-known pseudo-component method, it is more efficient than that method because it is less arbitrary and it often requires less computer time

Rigorous Multicomponent Reactive Separations Modelling: Complete Consideration of Reaction-Diffusion Phenomena

International Nuclear Information System (INIS)

Ahmadi, A.; Meyer, M.; Rouzineau, D.; Prevost, M.; Alix, P.; Laloue, N.

2010-01-01

This paper gives the first step of the development of a rigorous multicomponent reactive separation model. Such a model is highly essential to further the optimization of acid gases removal plants (CO 2 capture, gas treating, etc.) in terms of size and energy consumption, since chemical solvents are conventionally used. Firstly, two main modelling approaches are presented: the equilibrium-based and the rate-based approaches. Secondly, an extended rate-based model with rigorous modelling methodology for diffusion-reaction phenomena is proposed. The film theory and the generalized Maxwell-Stefan equations are used in order to characterize multicomponent interactions. The complete chain of chemical reactions is taken into account. The reactions can be kinetically controlled or at chemical equilibrium, and they are considered for both liquid film and liquid bulk. Thirdly, the method of numerical resolution is described. Coupling the generalized Maxwell-Stefan equations with chemical equilibrium equations leads to a highly non-linear Differential-Algebraic Equations system known as DAE index 3. The set of equations is discretized with finite-differences as its integration by Gear method is complex. The resulting algebraic system is resolved by the Newton- Raphson method. Finally, the present model and the associated methods of numerical resolution are validated for the example of esterification of methanol. This archetype non-electrolytic system permits an interesting analysis of reaction impact on mass transfer, especially near the phase interface. The numerical resolution of the model by Newton-Raphson method gives good results in terms of calculation time and convergence. The simulations show that the impact of reactions at chemical equilibrium and that of kinetically controlled reactions with high kinetics on mass transfer is relatively similar. Moreover, the Fick's law is less adapted for multicomponent mixtures where some abnormalities such as counter

Modelling the phase equilibria of multicomponent mixtures containing CO₂, alkanes, water, and/or alcohols using the quadrupolar CPA equation of state

DEFF Research Database (Denmark)

Bjørner, Martin Gamel; Kontogeorgis, Georgios

2016-01-01

In this work, a quadrupolar cubic plus association (qCPA) equation of state is evaluated for its ability to predict the phase equilibria of multicomponent mixtures containing CO2 and alkanes, alcohols, and/or water. A single binary interaction parameter is employed in qCPA for all binary combinat...... CPA yields the best results of all the models for the prediction of dew point pressures....

Thermophysical Properties of Fluid Latent Heat Storage Material using Urea-Water Mixture

Science.gov (United States)

Hokamura, Taku; Ohkubo, Hidetoshi; Ashizawa, Kiyonori

This study is concerned with the measurement of thermophysical properties of a urea-water mixture with the aim of adopting the mixture as a latent heat storage material for air-conditioning systems. The urea-water mixture is made of natural substances and has a good fluidity. The urea concentration in the mixture was controlled by measuring the refractive index of the mixture. Being a multi-component substance, a urea-water solution has a liquid-solid co-existent phase on a phase-diagram. Therefore, the liquidus temperature was measured to establish a relationship between the fraction of the solid-phase and temperature. Furthermore, apparent values of specific heat and coefficient of viscosity were measured in the two-phase region where the solid phase is ice. The apparent specific heat and coefficient of viscosity were measure by using an adiabatic calorimeter and a stirring torque meter respectively. The results revealed that the urea-water mixture can probably be used as a latent heat storage material of good fluidity.

Innovative aspects of protein stability in ionic liquid mixtures.

Science.gov (United States)

Kumar, Awanish; Venkatesu, Pannuru

2018-06-01

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

Velocity of large bubble in liquid-solid mixture in a vertical tube

International Nuclear Information System (INIS)

Hamaguchi, H.; Sakaguchi, T.

1995-01-01

The upward movement of a large bubble in a stationary mixture of liquid and solid is one of the most fundamental phenomena of gas-liquid-solid three phase slug flow in a vertical tube. The purpose of this study is to make clear the characteristic of the rising velocity of this fundamental flow experimentally. The rising velocity of a large bubble V in a liquid-solid mixture was measured and compared with the velocity V o in a liquid (without solid). The experimental results were correlated using a non-dimensional velocity V * (=V/V o ), and the following results were obtained. It was found that the characteristic of the rising velocity differs according to the tube diameter and the liquid viscosity, or the Galileo number in the non-dimensional expression. It can be classified into two regimes. (i) When the liquid viscosity is large (or the tube diameter is small), V * decreases linearly against the volumetric solid fraction ε of the mixture. (ii) When the viscosity is small, on the other hand, the relation between V * and ε is not linear. This classification can be explained by the results in the previous papers by the authors dealing with a large bubble in a liquid

Velocity of large bubble in liquid-solid mixture in a vertical tube

Energy Technology Data Exchange (ETDEWEB)

Hamaguchi, H.; Sakaguchi, T. [Kobe Univ., Kobe (Japan)

1995-09-01

The upward movement of a large bubble in a stationary mixture of liquid and solid is one of the most fundamental phenomena of gas-liquid-solid three phase slug flow in a vertical tube. The purpose of this study is to make clear the characteristic of the rising velocity of this fundamental flow experimentally. The rising velocity of a large bubble V in a liquid-solid mixture was measured and compared with the velocity V{sub o} in a liquid (without solid). The experimental results were correlated using a non-dimensional velocity V{sup *}(=V/V{sub o}), and the following results were obtained. It was found that the characteristic of the rising velocity differs according to the tube diameter and the liquid viscosity, or the Galileo number in the non-dimensional expression. It can be classified into two regimes. (i) When the liquid viscosity is large (or the tube diameter is small), V{sup *} decreases linearly against the volumetric solid fraction {epsilon} of the mixture. (ii) When the viscosity is small, on the other hand, the relation between V{sup *} and {epsilon} is not linear. This classification can be explained by the results in the previous papers by the authors dealing with a large bubble in a liquid.

Ionic-Liquid Based Separation of Azeotropic Mixtures

DEFF Research Database (Denmark)

Kulajanpeng, Kusuma; Suriyapraphadilok, Uthaiporn; Gani, Rafiqul

2014-01-01

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

Potential Theory of Multicomponent Adsorption

DEFF Research Database (Denmark)

Shapiro, Alexander; Stenby, Erling Halfdan

1998-01-01

We developed a theory of multicomponent adsorption on the basis of the potential concept originally suggested by Polanyi. The mixture is considered as a heterogeneous substance segregated in the external field emitted by the adsorbent. The same standard equation of state, with no additional fitting...... and high degree of predictability of the theory developed....... the potential theory and the spreading pressure concept is established, and problems of the theory consistency are studied. Numerical algorithms are suggested for evaluation of the segregated state of the mixture in the potential field of adsorption forces. Comparison with experimental data shows good agreement...

Hydrogen Separation by Natural Zeolite Composite Membranes: Single and Multicomponent Gas Transport

Directory of Open Access Journals (Sweden)

Afrooz Farjoo

2017-10-01

Full Text Available Single and multicomponent gas permeation tests were used to evaluate the performance of metal-supported clinoptilolite membranes. The efficiency of hydrogen separation from lower hydrocarbons (methane, ethane, and ethylene was studied within the temperature and pressure ranges of 25–600 °C and 110–160 kPa, respectively. The hydrogen separation factor was found to reduce noticeably in the gas mixture compared with single gas experiments at 25 °C. The difference between the single and multicomponent gas results decreased as the temperature increased to higher than 300 °C, which is when the competitive adsorption–diffusion mechanism was replaced by Knudsen diffusion or activated diffusion mechanisms. To evaluate the effect of gas adsorption, the zeolite surface isotherms of each gas in the mixture were obtained from 25 °C to 600 °C. The results indicated negligible adsorption of individual gases at temperatures higher than 300 °C. Increasing the feed pressure resulted in a higher separation efficiency for the individual gases compared with the multicomponent mixture, due to the governing effect of the adsorptive mechanism. This study provides valuable insight into the application of natural zeolites for the separation of hydrogen from a mixture of hydrocarbons.

Local composition shift of mixed working fluid in gas–liquid flow with phase transition

International Nuclear Information System (INIS)

Xu Xiongwen; Liu Jinping; Cao Le; Li Zeyu

2012-01-01

Local composition shift is an important characteristic of gas-liquid mixture flow with phase transition. It affects the heat transfer process, stream sonic velocity and the mixture distribution in the thermodynamic cycle. Presently, it is mainly calculated through the empirical models of the void fraction from pure fluid experiments. In this paper, we made efforts to obtain it and its rules basing on conservation equations derivation. The result calculated with propane/i-butane binary mixture was verified by the experiment in the evaporator of a refrigerator. As an extending, it was applied to a ternary mixture with components of methane, propane and butane and more information was presented and analyzed. The calculation approach presented in this paper can be applied any multicomponent mixture, and the rules will be helpful to improve the composition shift theory. - Highlights: ► Local composition shift of mixed working fluid in gas–liquid flow was modelled. ► A solution method for local composition of gas–liquid flow was proposed. ► The solution method was verified by the experimental result. ► Local composition shift mechanism of gas–liquid flow was studied

Representation and validation of liquid densities for pure compounds and mixtures

DEFF Research Database (Denmark)

Diky, Vladimir; O'Connell, John P.; Abildskov, Jens

2015-01-01

Reliable correlation and prediction of liquid densities are important for designing chemical processes at normal and elevated pressures. A corresponding-states model from molecular theory was extended to yield a robust method for quality testing of experimental data that also provides predicted...... values at unmeasured conditions. The model has been shown to successfully represent and validate the pressure and temperature dependence of liquid densities greater than 1.5 of the critical density for pure compounds, binary mixtures, and ternary mixtures from the triple to critical temperatures...

Liquid-liquid extraction of beryllium (II) using Cyanex 923 in kerosene from sodium acetate medium

International Nuclear Information System (INIS)

Kamble, Pravin N.; Madane, Namdev S.; Mohite, Baburao S.

2013-01-01

Liquid-liquid extraction of beryllium(II) from sodium acetate media using cyanex 923 in kerosene has been carried out. Beryllium(II) was quantitatively extracted from 1x10 -1 M sodium acetate with 1x10 -2 M cyanex 923 in kerosene. It was stripped quantitatively from the organic phase with 1M H 2 SO 4 and determined spectrophotometrically with eriochrome cyanine R at 525 nm. The effect of concentrations of sodium acetate, metal ions and strippants have been studied. Separation of beryllium(II) from other elements was achieved from binary as well as from multicomponent mixtures. The method is simple, rapid and selective with good reproducibility (approximately±2%). (author)

Inverse Opal Photonic Crystals as an Optofluidic Platform for Fast Analysis of Hydrocarbon Mixtures.

Science.gov (United States)

Xu, Qiwei; Mahpeykar, Seyed Milad; Burgess, Ian B; Wang, Xihua

2018-06-13

Most of the reported optofluidic devices analyze liquid by measuring its refractive index. Recently, the wettability of liquid on various substrates has also been used as a key sensing parameter in optofluidic sensors. However, the above-mentioned techniques face challenges in the analysis of the relative concentration of components in an alkane hydrocarbon mixture, as both refractive indices and wettabilities of alkane hydrocarbons are very close. Here, we propose to apply volatility of liquid as the key sensing parameter, correlate it to the optical property of liquid inside inverse opal photonic crystals, and construct powerful optofluidic sensors for alkane hydrocarbon identification and analysis. We have demonstrated that via evaporation of hydrocarbons inside the periodic structure of inverse opal photonic crystals and observation of their reflection spectra, an inverse opal film could be used as a fast-response optofluidic sensor to accurately differentiate pure hydrocarbon liquids and relative concentrations of their binary and ternary mixtures in tens of seconds. In these 3D photonic crystals, pure chemicals with different volatilities would have different evaporation rates and can be easily identified via the total drying time. For multicomponent mixtures, the same strategy is applied to determine the relative concentration of each component simply by measuring drying time under different temperatures. Using this optofluidic sensing platform, we have determined the relative concentrations of ternary hydrocarbon mixtures with the difference of only one carbon between alkane hydrocarbons, which is a big step toward detailed hydrocarbon analysis for practical use.

An isotherm-based thermodynamic model of multicomponent aqueous solutions, applicable over the entire concentration range.

Science.gov (United States)

Dutcher, Cari S; Ge, Xinlei; Wexler, Anthony S; Clegg, Simon L

2013-04-18

In previous studies (Dutcher et al. J. Phys. Chem. C 2011, 115, 16474-16487; 2012, 116, 1850-1864), we derived equations for the Gibbs energy, solvent and solute activities, and solute concentrations in multicomponent liquid mixtures, based upon expressions for adsorption isotherms that include arbitrary numbers of hydration layers on each solute. In this work, the long-range electrostatic interactions that dominate in dilute solutions are added to the Gibbs energy expression, thus extending the range of concentrations for which the model can be used from pure liquid solute(s) to infinite dilution in the solvent, water. An equation for the conversion of the reference state for solute activity coefficients to infinite dilution in water has been derived. A number of simplifications are identified, notably the equivalence of the sorption site parameters r and the stoichiometric coefficients of the solutes, resulting in a reduction in the number of model parameters. Solute concentrations in mixtures conform to a modified Zdanovskii-Stokes-Robinson mixing rule, and solute activity coefficients to a modified McKay-Perring relation, when the effects of the long-range (Debye-Hückel) term in the equations are taken into account. Practical applications of the equations to osmotic and activity coefficients of pure aqueous electrolyte solutions and mixtures show both satisfactory accuracy from low to high concentrations, together with a thermodynamically reasonable extrapolation (beyond the range of measurements) to extreme concentration and to the pure liquid solute(s).

Thermodynamics of mixtures containing alkoxyethanols. XXVIII: Liquid-liquid equilibria for 2-phenoxyethanol + selected alkanes

Energy Technology Data Exchange (ETDEWEB)

Alonso, Victor; Garcia, Mario [G.E.T.E.F., Grupo Especializado en Termodinamica de Equilibrio entre Fases, Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, E-47071 Valladolid (Spain); Gonzalez, Juan Antonio, E-mail: jagl@termo.uva.es [G.E.T.E.F., Grupo Especializado en Termodinamica de Equilibrio entre Fases, Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, E-47071 Valladolid (Spain); Garcia De La Fuente, Isaias; Cobos, Jose Carlos [G.E.T.E.F., Grupo Especializado en Termodinamica de Equilibrio entre Fases, Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, E-47071 Valladolid (Spain)

2011-07-10

Highlights: {yields} LLE coexistence curves were determined for mixtures of 2PhEE with alkanes. {yields} UCST values are higher for n-alkane systems than for solutions with cyclic alkanes. {yields} For the latter mixtures, UCST increases with the size of the alkyl group attached. {yields} Alkoxyethanol-alkoxyethanol interactions are enhanced by aromatic group in cellosolve. - Abstract: The coexistence curves of the liquid-liquid equilibria (LLE) for systems of 2-phenoxyethanol (2PhEE) with heptane, octane, cyclohexane, methylcyclohexane or ethylcyclohexane have been determined by the method of the critical opalescence using a laser scattering technique. All the curves show an upper critical solution temperature (UCST), have a rather horizontal top and their symmetry depends on the relative size of the mixture compounds. UCST values are higher for systems with linear alkanes than for solutions including cyclic alkanes. For these mixtures, the UCST increases with the size of the alkyl group attached to the cyclic part of the molecule. It is shown that interactions between alkoxyethanol molecules are stronger when the hydroxyether contains an aromatic group. Data are used to determine the critical exponent for the order parameter mole fraction. Values obtained are consistent with those provided by the Ising model or by the renormalization group theory.

Thermodynamics of mixtures containing alkoxyethanols. XXVIII: Liquid-liquid equilibria for 2-phenoxyethanol + selected alkanes

International Nuclear Information System (INIS)

Alonso, Victor; Garcia, Mario; Gonzalez, Juan Antonio; Garcia De La Fuente, Isaias; Cobos, Jose Carlos

2011-01-01

Highlights: → LLE coexistence curves were determined for mixtures of 2PhEE with alkanes. → UCST values are higher for n-alkane systems than for solutions with cyclic alkanes. → For the latter mixtures, UCST increases with the size of the alkyl group attached. → Alkoxyethanol-alkoxyethanol interactions are enhanced by aromatic group in cellosolve. - Abstract: The coexistence curves of the liquid-liquid equilibria (LLE) for systems of 2-phenoxyethanol (2PhEE) with heptane, octane, cyclohexane, methylcyclohexane or ethylcyclohexane have been determined by the method of the critical opalescence using a laser scattering technique. All the curves show an upper critical solution temperature (UCST), have a rather horizontal top and their symmetry depends on the relative size of the mixture compounds. UCST values are higher for systems with linear alkanes than for solutions including cyclic alkanes. For these mixtures, the UCST increases with the size of the alkyl group attached to the cyclic part of the molecule. It is shown that interactions between alkoxyethanol molecules are stronger when the hydroxyether contains an aromatic group. Data are used to determine the critical exponent for the order parameter mole fraction. Values obtained are consistent with those provided by the Ising model or by the renormalization group theory.

Spinodal decomposition in multicomponent fluid mixtures: A molecular dynamics study

DEFF Research Database (Denmark)

Laradji, Mohamed; Mouritsen, Ole G.; Toxvaerd, Søren

1996-01-01

parameter, leading to large growth-exponent values, the dynamics in multicomponent fluids (p = 3, 4) is found to follow a t(1/3) growth law, where t is time, which we relate to a long-wavelength evaporation-condensation process. These findings, which are proposed to be consequences of the compact domain...

Application of some geometrical and empirical models to excess molar volume for the multi-component mixtures at T = 298.15 K

International Nuclear Information System (INIS)

Iloukhani, H.; Khanlarzadeh, K.

2012-01-01

Highlights: ► Excess molar volume of quartenary mixtures of 1-chlorobutane, 2-chlorobutane, butylamine, and butylacetate was determined. ► The experimental data were correlated by some empirical and semi empirical models. ► A comparison with PFP theory has been successfully applied from binary data. - Abstract: Densities of the quaternary mixture consisting of {1-chlorobutane (1) + 2-chlorobutane (2) + butylamine (3) + butylacetate (4)} and related ternary mixtures of {1-chlorobutane (1) + 2-chlorobutane (2) + butylamine (3)}, {1-chlorobutane (1) + 2-chlorobutane (2) + butylacetate (4)}, {2-chlorobutane (2) + butylamine (3) + butylacetate (4)}, and binary systems of {1-chlorobutane (1) + 2-chlorobutane (2)}, {2-chlorobutane (2) + butylamine (3)}, were measured over the whole range of composition at T = 298.15 K and ambient pressure. Excess molar volumes, V m E , for the mixtures were derived and correlated as a function of mole fraction by using the Redlich–Kister and the Cibulka equations for binary and ternary mixtures, respectively. From the experimental data, partial molar volumes, V m,i and excess partial molar volumes, V m,i E were also calculated for binary systems. The experimental results of the constituted binary mixtures have been used to test the applicability of the Prigogine–Flory–Paterson (PFP) theory. A number of geometrical and empirical equations were also used to verify their ability to predict ternary and quaternary properties from their lower order mixtures. The experimental data were used to evaluate the nature and type of intermolecular interactions in multi-component mixtures.

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Development of an atomic mobility database for liquid phase in multicomponent Al alloys. Focusing on binary systems

Energy Technology Data Exchange (ETDEWEB)

Wang, Shaoqing; Du, Yong; Zhang, Lijun [Central South Univ., Changsha, Hunan (China). State Key Laboratory of Powder Metallurgy; Liu, Dandan [Central South Univ., Changsha, Hunan (China). State Key Laboratory of Powder Metallurgy; Central South Univ., Changsha, Hunan (China). School of Materials Science and Engineering; Chen, Qing; Engstroem, Anders [Thermo-Calc Software AB, Stockholm (Sweden)

2013-08-15

An atomic mobility database for binary liquid phase in multicomponent Al-Cu-Fe-Mg-Mn-Ni-Si-Zn alloys was established based on critically reviewed experimental and theoretical diffusion data by using DICTRA (Diffusion Controlled TRAnsformation) software. The impurity diffusivities of the elements with limited experimental data are obtained by means of the least-squares method and semi-empirical correlations. Comprehensive comparisons between the calculated and measured diffusivities indicate that most of the reported diffusivities can be well reproduced by the currently obtained atomic mobilities. The reliability of this diffusivity database is further validated by comparing the simulated concentration profiles with the measured ones, as well as the measured main inter-diffusion coefficients of liquid Al-Cu-Zn alloys with the extrapolated ones from the present binary atomic mobility database. The approach is of general validity and applicable to establish mobility databases of other liquid alloys. (orig.)

Quantum turbulence in cold multicomponent matter

Science.gov (United States)

Pshenichnyuk, Ivan A.

2018-02-01

Quantum vortices are pivotal for understanding of phenomena in quantum hydrodynamics. Vortices were observed in different physical systems like trapped dilute Bose-Einstein condensates, liquid helium, exciton-polariton condensates and other types of systems. Foreign particles attached to the vortices often serve for a visualization of the vortex shape and kinematics in superfluid experiments. Fascinating discoveries were made in the field of cold quantum mixtures, where vortices created in one component may interact with the other component. This works raise the fundamental question of the interaction between quantum vortices and matter. The generalized nonlinear Schrodinger equation based formalism is applied here to model three different processes involving the interaction of quantum vortices with foreign particles: propagation of a fast classical particle in a superfluid under the influence of sound waves, scattering of a single fermion by a quantized vortex line and dynamics of vortex pairs doped with heavy bosonic matter. The obtained results allow to to clarify the details of recent experiments and acquire a better understanding of the multicomponent quantum turbulence.

Surface Structures of Binary Mixture of Ionic Liquids.

Czech Academy of Sciences Publication Activity Database

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

2017-01-01

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

Phase equilibrium and physical properties of biobased ionic liquid mixtures.

Science.gov (United States)

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

2018-02-28

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

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

Directory of Open Access Journals (Sweden)

Mirjana Lj. Kijevčanin

2008-11-01

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

Liquid-liquid extraction of uranium(VI) using Cyanex 272 in toluene from sodium salicylate medium

International Nuclear Information System (INIS)

Madane, Namdev S.; Nikam, Gurunath H.; Jadhav, Deepali V.; Mohite, Baburao S.

2011-01-01

Liquid-liquid extraction of U(VI) from sodium salicylate media using Cyanex 272 in toluene has been carried out. Uranium(VI) was quantitatively extracted from 1 x 10 -3 M sodium salicylate with 5 x 10 -4 M Cyanex 272 in toluene. It was stripped quantitatively from the organic phase with 1M HCl and determined spectrophotometrically with arsenazo(III) at 660 nm. The effect of concentrations of sodium salicylate, extractant, diluents, metal ion and strippants have been studied. Separation of uranium(VI) from other elements was achieved from binary as well as from multicomponent mixtures. The method was extended to determination of uranium(VI) in geological samples. The method is simple, rapid and selective with good reproducibility (approximately ± 2%). (author)

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

DEFF Research Database (Denmark)

Abildskov, Jens; O’Connell, John P.

2015-01-01

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

Phase Behavior of Aqueous NA-K-MG-CA-CI-NO3 Mixtures: Isopiestic Measurements and Thermodynamic Modeling

Energy Technology Data Exchange (ETDEWEB)

M.S. Gruszkiewiez; D.A. Palmer; R.D. Springer; P. Wang; A. Anderko

2006-09-14

A comprehensive model has been established for calculating thermodynamic properties of multicomponent aqueous systems containing the Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, Cl{sup -}, and NO{sub 3}{sup -} ions. The thermodynamic framework is based on a previously developed model for mixed-solvent electrolyte solutions. The framework has been designed to reproduce the properties of salt solutions at temperatures ranging from the freezing point to 300 C and concentrations ranging from infinite dilution to the fused salt limit. The model has been parameterized using a combination of an extensive literature database and new isopiestic measurements for thirteen salt mixtures at 140 C. The measurements have been performed using Oak Ridge National Laboratory's (ORNL) previously designed gravimetric isopiestic apparatus, which makes it possible to detect solid phase precipitation. Water activities are reported for mixtures with a fixed ratio of salts as a function of the total apparent salt mole fraction. The isopiestic measurements reported here simultaneously reflect two fundamental properties of the system, i.e., the activity of water as a function of solution concentration and the occurrence of solid-liquid transitions. The thermodynamic model accurately reproduces the new isopiestic data as well as literature data for binary, ternary and higher-order subsystems. Because of its high accuracy in calculating vapor-liquid and solid-liquid equilibria, the model is suitable for studying deliquescence behavior of multicomponent salt systems.

Digital holographic microscopy of phase separation in multicomponent lipid membranes

Science.gov (United States)

Farzam Rad, Vahideh; Moradi, Ali-Reza; Darudi, Ahmad; Tayebi, Lobat

2016-12-01

Lateral in-homogeneities in lipid compositions cause microdomains formation and change in the physical properties of biological membranes. With the presence of cholesterol and mixed species of lipids, phospholipid membranes segregate into lateral domains of liquid-ordered and liquid-disordered phases. Coupling of two-dimensional intralayer phase separations and interlayer liquid-crystalline ordering in multicomponent membranes has been previously demonstrated. By the use of digital holographic microscopy (DHMicroscopy), we quantitatively analyzed the volumetric dynamical behavior of such membranes. The specimens are lipid mixtures composed of sphingomyelin, cholesterol, and unsaturated phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine. DHMicroscopy in a transmission mode is an effective tool for quantitative visualization of phase objects. By deriving the associated phase changes, three-dimensional information on the morphology variation of lipid stacks at arbitrary time scales is obtained. Moreover, the thickness distribution of the object at demanded axial planes can be obtained by numerical focusing. Our results show that the volume evolution of lipid domains follows approximately the same universal growth law of previously reported area evolution. However, the thickness of the domains does not alter significantly by time; therefore, the volume evolution is mostly attributed to the changes in area dynamics. These results might be useful in the field of membrane-based functional materials.

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

Directory of Open Access Journals (Sweden)

X. Li

2014-01-01

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

Thermodynamics of liquid mixtures of methane and ethene

Energy Technology Data Exchange (ETDEWEB)

Calado, J C.G.; Soares, V A.M.

1977-08-01

Experiments conducted by Portugal's Instituto Superior Tecnico provide liquid and vapor equilibrium compositions and pressures for the methane-ethene system at 103.94 and -115.77 K as well as the molar volumes of the mixtures at the lower temperature. From the results, researchers estimated the excess Gibbs energies at these tempertures and the molar enthalpy of mixing.

Multiphase, multicomponent phase behavior prediction

Science.gov (United States)

Dadmohammadi, Younas

Accurate prediction of phase behavior of fluid mixtures in the chemical industry is essential for designing and operating a multitude of processes. Reliable generalized predictions of phase equilibrium properties, such as pressure, temperature, and phase compositions offer an attractive alternative to costly and time consuming experimental measurements. The main purpose of this work was to assess the efficacy of recently generalized activity coefficient models based on binary experimental data to (a) predict binary and ternary vapor-liquid equilibrium systems, and (b) characterize liquid-liquid equilibrium systems. These studies were completed using a diverse binary VLE database consisting of 916 binary and 86 ternary systems involving 140 compounds belonging to 31 chemical classes. Specifically the following tasks were undertaken: First, a comprehensive assessment of the two common approaches (gamma-phi (gamma-ϕ) and phi-phi (ϕ-ϕ)) used for determining the phase behavior of vapor-liquid equilibrium systems is presented. Both the representation and predictive capabilities of these two approaches were examined, as delineated form internal and external consistency tests of 916 binary systems. For the purpose, the universal quasi-chemical (UNIQUAC) model and the Peng-Robinson (PR) equation of state (EOS) were used in this assessment. Second, the efficacy of recently developed generalized UNIQUAC and the nonrandom two-liquid (NRTL) for predicting multicomponent VLE systems were investigated. Third, the abilities of recently modified NRTL model (mNRTL2 and mNRTL1) to characterize liquid-liquid equilibria (LLE) phase conditions and attributes, including phase stability, miscibility, and consolute point coordinates, were assessed. The results of this work indicate that the ϕ-ϕ approach represents the binary VLE systems considered within three times the error of the gamma-ϕ approach. A similar trend was observed for the for the generalized model predictions using

Detailed finite element method modeling of evaporating multi-component droplets

Energy Technology Data Exchange (ETDEWEB)

Diddens, Christian, E-mail: C.Diddens@tue.nl

2017-07-01

The evaporation of sessile multi-component droplets is modeled with an axisymmetic finite element method. The model comprises the coupled processes of mixture evaporation, multi-component flow with composition-dependent fluid properties and thermal effects. Based on representative examples of water–glycerol and water–ethanol droplets, regular and chaotic examples of solutal Marangoni flows are discussed. Furthermore, the relevance of the substrate thickness for the evaporative cooling of volatile binary mixture droplets is pointed out. It is shown how the evaporation of the more volatile component can drastically decrease the interface temperature, so that ambient vapor of the less volatile component condenses on the droplet. Finally, results of this model are compared with corresponding results of a lubrication theory model, showing that the application of lubrication theory can cause considerable errors even for moderate contact angles of 40°. - Graphical abstract:.

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

International Nuclear Information System (INIS)

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

1977-01-01

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

Gas--liquid equilibria in mixtures of hydrogen and thianaphthene

Energy Technology Data Exchange (ETDEWEB)

Sebastian, H M; Simnick, J J; Lin, H M; Chao, K C

1978-12-01

Gas--liquid equilibrium conditions in binary mixtures of hydrogen and thianaphthene were experimentally determined at temperature of 190 to 430/sup 0/C and pressures to 250 atm in a flow apparatus. The same apparatus was also employed to measure the vapor pressure of thianaphthene. Comparisons of the new mixture data with Chao--Seader and Grayson--Streed correlations show that both correlations predict the thianaphthene equilibrium ratios well but are in error by up to about 45 and 35% respectively for K-values of hydrogen. 4 figures, 2 tables.

Liquid, urea group-containing polyisocyanate mixtures and plastics derived therefrom

Energy Technology Data Exchange (ETDEWEB)

Buethe, I.; Marx, M.; Schoenleben, W.

1988-04-05

The invention relates to urea group-containing polyisocyanate mixtures which are liquid at room temperature and have an isocyanate group content of from 15 to 30 weight percent and a diphenylmethane diisocyanate content of from 55 to 90 weight percent. These mixtures are obtained through the reaction of polyoxyalkylene polyamines having a functionality of from 2 to 5 and an amine number from 20 to 250 with a polyisocyanate selected from the group consisting of: a mixture of diphenylmethane diisocyanates and polyphenyl polymethylene polysocyanates having a diphenylmethane diisocyanate content of from 55 to 90 wt%, or at least one diphenylmethane diisocyanate isomer. The polyisocyanate mixtures claimed in the invention are used to prepare dense or cellular polyurethane and/or polyisocyanurate plastics, in particular, flexible polyurethane foams.

Computation of liquid-liquid equilibria and phase stabilities: implications for RH-dependent gas/particle partitioning of organic-inorganic aerosols

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A. Zuend

2010-08-01

Full Text Available Semivolatile organic and inorganic aerosol species partition between the gas and aerosol particle phases to maintain thermodynamic equilibrium. Liquid-liquid phase separation into an organic-rich and an aqueous electrolyte phase can occur in the aerosol as a result of the salting-out effect. Such liquid-liquid equilibria (LLE affect the gas/particle partitioning of the different semivolatile compounds and might significantly alter both particle mass and composition as compared to a one-phase particle. We present a new liquid-liquid equilibrium and gas/particle partitioning model, using as a basis the group-contribution model AIOMFAC (Zuend et al., 2008. This model allows the reliable computation of the liquid-liquid coexistence curve (binodal, corresponding tie-lines, the limit of stability/metastability (spinodal, and further thermodynamic properties of multicomponent systems. Calculations for ternary and multicomponent alcohol/polyol-water-salt mixtures suggest that LLE are a prevalent feature of organic-inorganic aerosol systems. A six-component polyol-water-ammonium sulphate system is used to simulate effects of relative humidity (RH and the presence of liquid-liquid phase separation on the gas/particle partitioning. RH, salt concentration, and hydrophilicity (water-solubility are identified as key features in defining the region of a miscibility gap and govern the extent to which compound partitioning is affected by changes in RH. The model predicts that liquid-liquid phase separation can lead to either an increase or decrease in total particulate mass, depending on the overall composition of a system and the particle water content, which is related to the hydrophilicity of the different organic and inorganic compounds. Neglecting non-ideality and liquid-liquid phase separations by assuming an ideal mixture leads to an overestimation of the total particulate mass by up to 30% for the composition and RH range considered in the six

Investigation on the structure of liquid N-methylformamide-dimethylsulfoxide mixtures

Science.gov (United States)

Cordeiro, João M. M.; Soper, Alan K.

2011-03-01

The structures of liquid mixtures of N-methylformamide (NMF) and dimethyl sulfoxide (DMSO) at two concentrations (80% and 50% NMF) are investigated using a combination of neutron diffraction augmented with isotopic substitution and empirical potential structure refinement simulations. The results indicate that the NMF and DMSO molecules are hydrogen-bonded to one another with a preference for NMF-DMSO hydrogen bonding, compared to the NMF-NMF ones. The liquid is orientationally structured as a consequence of these hydrogen bonds between molecules. NMF-DMSO dimers are very stable species in the bulk of the mixture. The structure of the dimers is such that the angle between the molecular dipole moments is around 60°. The NMF molecules are well solvated in DMSO with potential implications for peptides solvation in this solvent.

Experimental Investigation Evaporation of Liquid Mixture Droplets during Depressurization into Air Stream

Science.gov (United States)

Liu, L.; Bi, Q. C.; Terekhov, Victor I.; Shishkin, Nikolay E.

2010-03-01

The objective of this study is to develop experimental method to study the evaporation process of liquid mixture droplets during depressurization and into air stream. During the experiment, a droplet was suspended on a thermocouple; an infrared thermal imager was used to measure the droplet surface temperature transition. Saltwater droplets were used to investigate the evaporation process during depressurization, and volatile liquid mixtures of ethanol, methanol and acetone in water were applied to experimentally research the evaporation into air stream. According to the results, the composition and concentration has a complex influence on the evaporation rate and the temperature transition. With an increase in the share of more volatile component, the evaporation rate increases. While, a higher salt concentration in water results in a lower evaporation rate. The shape variation of saltwater droplet also depends on the mass concentration in solution, whether it is higher or lower than the eutectic point (22.4%). The results provide important insight into the complex heat and mass transfer of liquid mixture during evaporation.

Studies on Molecular Interaction in Ternary Liquid Mixtures

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R. Uvarani

2010-01-01

Full Text Available Ultrasonic velocity, density and viscosity for the ternary liquid mixtures of cyclohexanone with 1-propanol and 1-butanol in carbon tetrachloride were measured at 303 K. The acoustical parameters and their excess values were calculated. The trends in the variation of these excess parameters were used to discuss the nature and strength of the interactions present between the component molecules.

Thermodynamics of liquid mixtures of methane and ethene

Energy Technology Data Exchange (ETDEWEB)

Calado, J.C.G.; Soares, V.A.M.

1977-08-01

Experiments conducted by Portugal's Instituto Superior Tecnico provide liquid and vapor equilibrium compositions and pressures for the methane-ethene system at 103.94 and -115.77 K as well as the molar volumes of the mixtures at the lower temperature. From the results, researchers estimated the excess Gibbs energies at these tempertures and the molar enthalpy of mixing.

The study on process of recycling uranium in mixture of residue and liquid

International Nuclear Information System (INIS)

Zhang Jie; Shen Weiwei; Hao Jidong; Wu Jiangming

2014-01-01

The treat method of mixture of residue and liquid produced from HWR nuclear fuel chemical process using some kind of U_3O_8 powder was studied in this experiment. For recycling the uranium in mixture of residue and liquid, chemical dissolving method, washing and centrifuging method and dilute nitric acid leaching uranium method was contrasted in this test. The merit of dilute nitric acid leaching uranium method is simpler, more effective and higher uranium recycling ratio. Next, dilute nitric acid leaching uranium method was studied systematically. As a result, the main influence factors of uranium recycling ratio is dip sour degree and dip sour temperature. The influence law of factors to uranium recycling ratio and filtering effect was found out also. Along with increasing of dip sour degree and dip sour temperature, uranium recycling ratio increases and speed of filtrate increases also. At last, the process of batch treating mixture of residue and liquid was build and abundant uranium was recycled. (authors)

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

Science.gov (United States)

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

2017-08-03

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

Mixing Rules Formulation for a Kinetic Model of the Langmuir-Hinshelwood Semipredictive Type Applied to the Heterogeneous Photocatalytic Degradation of Multicomponent Mixtures

Directory of Open Access Journals (Sweden)

John Wilman Rodriguez-Acosta

2014-01-01

Full Text Available Mixing rules coupled to a semipredictive kinetic model of the Langmuir-Hinshelwood type were proposed to determine the behavior of the heterogeneous solar photodegradation with TiO2-P25 of multicomponent mixtures at pilot scale. The kinetic expressions were expressed in terms of the effective concentration of total organic carbon (xTOC. An expression was obtained in a generalized form which is a function of the mixing rules as a product of a global contribution of the reaction rate constant k′ and a mixing function fC. Kinetic parameters of the model were obtained using the Nelder and Mead (N-M algorithm. The kinetic model was validated with experimental data obtained from the degradation of binary mixtures of chlorinated compounds (DCA: dichloroacetic acid and 4-CP: 4-chlorophenol at different initial global concentration, using a CPC reactor at pilot scale. A simplex-lattice {2,3} design experiment was adopted to perform the runs.

Non-linearity parameter of binary liquid mixtures at elevated pressures

Indian Academy of Sciences (India)

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

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

Science.gov (United States)

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

2015-03-28

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

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

Science.gov (United States)

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

2012-05-14

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

Exposure of Mammalian Cells to Air-Pollutant Mixtures at the Air-Liquid Interface

Science.gov (United States)

It has been widely accepted that exposure of mammalian cells to air-pollutant mixtures at the air-liquid interface is a more realistic approach than exposing cell under submerged conditions. The VITROCELL systems, are commercially available systems for air-liquid interface expo...

Viscosity and diffusivity in melts: from unary to multicomponent systems

Science.gov (United States)

Chen, Weimin; Zhang, Lijun; Du, Yong; Huang, Baiyun

2014-05-01

Viscosity and diffusivity, two important transport coefficients, are systematically investigated from unary melt to binary to multicomponent melts in the present work. By coupling with Kaptay's viscosity equation of pure liquid metals and effective radii of diffusion species, the Sutherland equation is modified by taking the size effect into account, and further derived into an Arrhenius formula for the convenient usage. Its reliability for predicting self-diffusivity and impurity diffusivity in unary liquids is then validated by comparing the calculated self-diffusivities and impurity diffusivities in liquid Al- and Fe-based alloys with the experimental and the assessed data. Moreover, the Kozlov model was chosen among various viscosity models as the most reliable one to reproduce the experimental viscosities in binary and multicomponent melts. Based on the reliable viscosities calculated from the Kozlov model, the modified Sutherland equation is utilized to predict the tracer diffusivities in binary and multicomponent melts, and validated in Al-Cu, Al-Ni and Al-Ce-Ni melts. Comprehensive comparisons between the calculated results and the literature data indicate that the experimental tracer diffusivities and the theoretical ones can be well reproduced by the present calculations. In addition, the vacancy-wind factor in binary liquid Al-Ni alloys with the increasing temperature is also discussed. What's more, the calculated inter-diffusivities in liquid Al-Cu, Al-Ni and Al-Ag-Cu alloys are also in excellent agreement with the measured and theoretical data. Comparisons between the simulated concentration profiles and the measured ones in Al-Cu, Al-Ce-Ni and Al-Ag-Cu melts are further used to validate the present calculation method.

Structure and effective interactions in three-component hard sphere liquids.

Science.gov (United States)

König, A; Ashcroft, N W

2001-04-01

Complete and simple analytical expressions for the partial structure factors of the ternary hard sphere mixture are obtained within the Percus-Yevick approximation and presented as functions of relative packing fractions and relative hard sphere diameters. These solutions follow from the Laplace transform method as applied to multicomponent systems by Lebowitz [Phys. Rev. 133, A895 (1964)]. As an important application, we examine effective interactions in hard sphere liquid mixtures using the microscopic information contained in their partial structure factors. Thus the ensuring pair potential for an effective one-component system is obtained from the correlation functions by using an approximate inversion, and examples of effective potentials for three-component hard sphere mixtures are given. These mixtures may be of particular interest for the study of the packing aspects of melts that form glasses or quasicrystals, since noncrystalline solids often emerge from melts with at least three atomic constituents.

Multicomponent fluid flow analysis using a new set of conservation equations

International Nuclear Information System (INIS)

Kamali, Reza; Emdad, Homayoon; Alishahi, Mohammad M

2008-01-01

In this work hydrodynamics of multicomponent ideal gas mixtures have been studied. Starting from the kinetic equations, the Eulerian approach is used to derive a new set of conservation equations for the multicomponent system where each component may have different velocity and kinetic temperature. The equations are based on the Grad's method of moment derived from the kinetic model in a relaxation time approximation (RTA). Based on this model which contains separate equation sets for each component of the system, a computer code has been developed for numerical computation of compressible flows of binary gas mixture in generalized curvilinear boundary conforming coordinates. Since these equations are similar to the Navier-Stokes equations for the single fluid systems, the same numerical methods are applied to these new equations. The Roe's numerical scheme is used to discretize the convective terms of governing fluid flow equations. The prepared algorithm and the computer code are capable of computing and presenting flow fields of each component of the system separately as well as the average flow field of the multicomponent gas system as a whole. Comparison of the present code results with those of a more common algorithm based on the mixture theory in a supersonic converging-diverging nozzle provides the validation of the present formulation. Afterwards, a more involved nozzle cooling problem with a binary ideal gas (helium-xenon) is chosen to compare the present results with those of the ordinary mixture theory. The present model provides the details of the flow fields of each component separately which is not available otherwise. It is also shown that the separate fluids treatment, such as the present study, is crucial when considering time scales on the order of (or shorter than) the intercollisions relaxation times.

The effect of heat exchanger parameters on performance predictions for nonazeotropic refrigerant mixtures in liquid-liquid heat pumps

International Nuclear Information System (INIS)

Stanger, S.; Den Braven, K.R.; Owre, T.A.S.

1990-01-01

The effects of constant heat exchanger area on the coefficient of performance (COP) for liquid-liquid heat pumps were analyzed for systems which use nonazeotropic mixtures as the working fluid. For this analysis, two different computer models were compared. In the first, the log mean temperature differences (LMTDs) through the heat exchangers were specified, and were held constant for all refrigerant compositions. The second method was constructed so that the heat exchanger UA product was held constant, thus approximating constant heat exchanger area over a range of refrigerant compositions. Results from these models show only a one percent difference in COP prediction between holding LMTD constant and holding UA constant over the range of mixture composition. This paper reports the models compared using mixtures of R-22/R-11 and R-22/R-114. It is also shown that changes in glide and lift temperatures have little influence on the differences between the two models

Multicomponent diffusion in two-temperature magnetohydrodynamics

International Nuclear Information System (INIS)

Ramshaw, J.D.; Chang, C.H.

1996-01-01

A recent hydrodynamic theory of multicomponent diffusion in multitemperature gas mixtures [J. D. Ramshaw, J. Non-Equilib. Thermodyn. 18, 121 (1993)] is generalized to include the velocity-dependent Lorentz force on charged species in a magnetic field B. This generalization is used to extend a previous treatment of ambipolar diffusion in two-temperature multicomponent plasmas [J. D. Ramshaw and C. H. Chang, Plasma Chem. Plasma Process. 13, 489 (1993)] to situations in which B and the electrical current density are nonzero. General expressions are thereby derived for the species diffusion fluxes, including thermal diffusion, in both single- and two-temperature multicomponent magnetohydrodynamics (MHD). It is shown that the usual zero-field form of the Stefan-Maxwell equations can be preserved in the presence of B by introducing generalized binary diffusion tensors dependent on B. A self-consistent effective binary diffusion approximation is presented that provides explicit approximate expressions for the diffusion fluxes. Simplifications due to the small electron mass are exploited to obtain an ideal MHD description in which the electron diffusion coefficients drop out, resistive effects vanish, and the electric field reduces to a particularly simple form. This description should be well suited for numerical calculations. copyright 1996 The American Physical Society

Synergy in lipofection by cationic lipid mixtures: superior activity at the gel-liquid crystalline phase transition.

Science.gov (United States)

Koynova, Rumiana; Wang, Li; MacDonald, Robert C

2007-07-12

Some mixtures of two cationic lipids including phospholipid compounds (O-ethylphosphatidylcholines) as well as common, commercially available cationic lipids, such as dimethylammonium bromides and trimethylammonium propanes, deliver therapeutic DNA considerably more efficiently than do the separate molecules. In an effort to rationalize this widespread "mixture synergism", we examined the phase behavior of the cationic lipid mixtures and constructed their binary phase diagrams. Among a group of more than 50 formulations, the compositions with maximum delivery activity resided unambiguously in the solid-liquid crystalline two-phase region at physiological temperature. Thus, the transfection efficacy of formulations exhibiting solid-liquid crystalline phase coexistence is more than 5 times higher than that of formulations in the gel (solid) phase and over twice that of liquid crystalline formulations; phase coexistence occurring at physiological temperature thus appears to contribute significantly to mixture synergism. This relationship between delivery activity and physical property can be rationalized on the basis of the known consequences of lipid-phase transitions, namely, the accumulation of defects and increased disorder at solid-liquid crystalline phase boundaries. Packing defects at the borders of coexisting solid and liquid crystalline domains, as well as large local density fluctuations, could be responsible for the enhanced fusogenicity of mixtures. This study leads to the important conclusion that manipulating the composition of the lipid carriers so that their phase transition takes place at physiological temperature can enhance their delivery efficacy.

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.

Mass flows in N2 - Ar - O2 mixture for a temperature range of 80 K to 100 K in presence of concentration gradients

International Nuclear Information System (INIS)

Cristescu, I.; Peculea, M.; Serban, I.

1992-01-01

In separation processes of multicomponent mixtures by cryogenic distillation, out of mass transfer at liquid-vapor interface, an essential part is played by Fick diffusion of the two phases. In the present study we have developed a calculus of the generalized diffusion coefficients based on the Chapman-Cowling theory, and we applied it for the N 2 - Ar - O 2 mixture in vapor phase. After computing Fick's law of diffusion for a tri-component nonreactive mixture in which diffusion is occurring in x -direction only, under constant pressure, we have established the time variation of the N 2 , Ar, and O 2 concentrations, taking into account the initial distribution of concentrations and boundary conditions. (Author)

Measurements and modeling of quaternary (liquid + liquid) equilibria for mixtures of (methanol or ethanol + water + toluene + n-dodecane)

International Nuclear Information System (INIS)

Mohammad Doulabi, F.S.; Mohsen-Nia, M.; Modarress, H.

2006-01-01

The extraction of aromatic compound toluene from alkane, dodecane, by mixed solvents (water + methanol) (water + ethanol) and (methanol + ethanol) have been studied by (liquid + liquid) equilibrium (LLE) measurements at three temperatures (298.15, 303.15, and 313.15) K and ambient pressure. The compositions of liquid phases at equilibrium were determined by gas liquid chromatography. The experimental tie-line data for three quaternary mixtures of {(water + methanol) + toluene + dodecane}, {(water + ethanol) + toluene + dodecane}, and {(methanol + ethanol) + toluene + dodecane} are presented. The experimental quaternary LLE data have been satisfactorily correlated by using the UNIQUAC and NRTL activity coefficient models. The parameters of the models have been evaluated and presented. The tie-line data of the studied quaternary mixtures also were correlated using the Hand method. The partition coefficients and the selectivity factor of solvent are calculated and compared for the three mixed solvents. The comparisons indicate that the selectivity factor for mixed solvent (methanol + ethanol) is higher than the other two mixed solvents at the three studied temperatures. However, considering the temperature variations of partition coefficients of toluene in two liquid phases at equilibrium, an optimum temperature may be obtained for an efficient extraction of toluene from dodecane by the mixed solvents

Simultaneous determination of 2 aconitum alkaloids and 12 ginsenosides in Shenfu injection by ultraperformance liquid chromatography coupled with a photodiode array detector with few markers to determine multicomponents

Directory of Open Access Journals (Sweden)

Ai-Hua Ge

2015-06-01

Full Text Available A method with few markers to determine multicomponents was established and validated to evaluate the quality of Shenfu injection by ultraperformance liquid chromatography coupled with a photodiode array detector. The separations were performed on an ACQUITY UPLC BEH C18 (2.1 × 50 mm2, 1.7 μm column. Methanol and 0.1% formic acid aqueous solution were used as the mobile phase. The flow rate was 0.3 mL/min. 2 aconitum alkaloids and 12 ginsenosides could be perfectly separated within 15 minutes. Ginsenoside Rg1 and benzoylmesaconine, the easily available active components, were employed as the maker components to calculate the relative correction factors of other components in Shenfu injection, Panax ginseng and Aconitum carmichaeli. The external standard method was also established to validate the feasibility of the method with few markers to determine multicomponents. Parameter p and the principal component analysis method were employed to investigate the disparities among batches for the effective quality control of Shenfu injection. The results demonstrated that the ultraperformance liquid chromatography coupled with a photodiode array detector method with few markers to determine multicomponents could be used as a powerful tool for the quality evaluation of traditional Chinese medicines and their preparations.

Crystallization In Multicomponent Glasses

International Nuclear Information System (INIS)

Kruger, A.A.; Hrma, P.R.

2009-01-01

In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

CRYSTALLIZATION IN MULTICOMPONENT GLASSES

Energy Technology Data Exchange (ETDEWEB)

KRUGER AA; HRMA PR

2009-10-08

In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

Quantum liquid droplets in a mixture of Bose-Einstein condensates

Science.gov (United States)

Cabrera, C. R.; Tanzi, L.; Sanz, J.; Naylor, B.; Thomas, P.; Cheiney, P.; Tarruell, L.

2018-01-01

Quantum droplets are small clusters of atoms self-bound by the balance of attractive and repulsive forces. Here, we report on the observation of droplets solely stabilized by contact interactions in a mixture of two Bose-Einstein condensates. We demonstrate that they are several orders of magnitude more dilute than liquid helium by directly measuring their size and density via in situ imaging. We show that the droplets are stablized against collapse by quantum fluctuations and that they require a minimum atom number to be stable. Below that number, quantum pressure drives a liquid-to-gas transition that we map out as a function of interaction strength. These ultradilute isotropic liquids remain weakly interacting and constitute an ideal platform to benchmark quantum many-body theories.

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

International Nuclear Information System (INIS)

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

2003-01-01

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

Vapor-liquid equilibrium of ethanol/ethyl acetate mixture in ultrasonic intensified environment

Energy Technology Data Exchange (ETDEWEB)

Mahdi, Taha; Ahmad, Arshad; Ripin, Adnan Nasef; Mohamed, Mahmoud [Universiti Teknologi Malaysia, Johor Bahru (Malaysia)

2014-05-15

A vapor-liquid equilibrium (VLE) study was conducted on ethanol/ethylacetate mixture as a preliminary step towards developing an ultrasonic-assisted distillation process for separating azeotropic mixtures. The influence of ultrasonic intensity and frequency on the vapor-liquid equilibrium (VLE) of the mixture was examined using a combination of four ultrasonic intensities in range of 100-400W/cm{sup 2} and three frequencies ranging from 25-68 kHz. The sonication was found to have significant impacts on the VLE of the system as it alters both the relative volatility and azeotrope point, with preference to lower frequency operation. A maximum relative volatility of 2.32 was obtained at an intensity of 300 W/cm{sup 2} and a frequency of 25 kHz coupled with complete elimination of ethanol-ethyl acetate azeotrope. Results from this work were also congruent with some experimental and theoretical works presented in the literature. These findings set a good beginning towards the development of an ultrasonic assisted distillation that is currently in progress.

Vapor-liquid equilibrium of ethanol/ethyl acetate mixture in ultrasonic intensified environment

International Nuclear Information System (INIS)

Mahdi, Taha; Ahmad, Arshad; Ripin, Adnan Nasef; Mohamed, Mahmoud

2014-01-01

A vapor-liquid equilibrium (VLE) study was conducted on ethanol/ethylacetate mixture as a preliminary step towards developing an ultrasonic-assisted distillation process for separating azeotropic mixtures. The influence of ultrasonic intensity and frequency on the vapor-liquid equilibrium (VLE) of the mixture was examined using a combination of four ultrasonic intensities in range of 100-400W/cm 2 and three frequencies ranging from 25-68 kHz. The sonication was found to have significant impacts on the VLE of the system as it alters both the relative volatility and azeotrope point, with preference to lower frequency operation. A maximum relative volatility of 2.32 was obtained at an intensity of 300 W/cm 2 and a frequency of 25 kHz coupled with complete elimination of ethanol-ethyl acetate azeotrope. Results from this work were also congruent with some experimental and theoretical works presented in the literature. These findings set a good beginning towards the development of an ultrasonic assisted distillation that is currently in progress

New models for predicting thermophysical properties of ionic liquid mixtures.

Science.gov (United States)

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

2015-10-28

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

Study on kinetics of description of gases and their mixtures through the interface

International Nuclear Information System (INIS)

Ermashkevich, V.N.; Kachalov, A.B.; Shlejfer, A.A.; Redin, Yu.A.

1986-01-01

The velocity of release of gases into a bubble and a cavity from liquid has been described. It is shown that at simultaneous desorption of several gases dissolved in liquid, into emerging bubble the contribution of each gas is proportional to its coefficient of solubility and is independent of concentration of these gases in liquid. For gases with solubility coefficients above 1000 kg/(m 3 xMPa), partial pressure readily reaches equilibrium. Nitric oxide dissolved in nitrogen tetroxide ranks among them. Alternatively, for gases with low solubility coefficients (for example, nitrogen in N 2 O 4 ), partial pressure in the cavity (bubble) increases slowly. An effect of any gas on the desorption rate of another gas has not been observed. The study allows to evaluate some parameters in formed cavities or in moving gaseous bubbles in multicomponent mixtures (in particular, in dissociating nitrogen tetroxide and in solutions on the basis of nitrogen tetroxide)

Density, viscosity and surface tension of liquid phase Beckmann rearrangement mixtures

NARCIS (Netherlands)

Zuidhof, K.T.; Croon, de M.H.J.M.; Schouten, J.C.; Tinge, J.T.

2015-01-01

We have determined the density, dynamic viscosity, and surface tension of liquid phase Beckmann rearrangement mixtures, consisting of e-caprolactam and fuming oleum. These important properties have been measured in wide ranges of both temperature and molar ratios of acid and e-caprolactam, covering

Phase stability analysis of liquid-liquid equilibrium with stochastic methods

Directory of Open Access Journals (Sweden)

G. Nagatani

2008-09-01

Full Text Available Minimization of Gibbs free energy using activity coefficient models and nonlinear equation solution techniques is commonly applied to phase stability problems. However, when conventional techniques, such as the Newton-Raphson method, are employed, serious convergence problems may arise. Due to the existence of multiple solutions, several problems can be found in modeling liquid-liquid equilibrium of multicomponent systems, which are highly dependent on the initial guess. In this work phase stability analysis of liquid-liquid equilibrium is investigated using the NRTL model. For this purpose, two distinct stochastic numerical algorithms are employed to minimize the tangent plane distance of Gibbs free energy: a subdivision algorithm that can find all roots of nonlinear equations for liquid-liquid stability analysis and the Simulated Annealing method. Results obtained in this work for the two stochastic algorithms are compared with those of the Interval Newton method from the literature. Several different binary and multicomponent systems from the literature were successfully investigated.

The Prediction of Surface Tension of Ternary Mixtures at Different Temperatures Using Artificial Neural Networks

Directory of Open Access Journals (Sweden)

Ali Khazaei

2014-07-01

Full Text Available In this work, artificial neural network (ANN has been employed to propose a practical model for predicting the surface tension of multi-component mixtures. In order to develop a reliable model based on the ANN, a comprehensive experimental data set including 15 ternary liquid mixtures at different temperatures was employed. These systems consist of 777 data points generally containing hydrocarbon components. The ANN model has been developed as a function of temperature, critical properties, and acentric factor of the mixture according to conventional corresponding-state models. 80% of the data points were employed for training ANN and the remaining data were utilized for testing the generated model. The average absolute relative deviations (AARD% of the model for the training set, the testing set, and the total data points were obtained 1.69, 1.86, and 1.72 respectively. Comparing the results with Flory theory, Brok-Bird equation, and group contribution theory has proved the high prediction capability of the attained model.

Combustible gas production (methane) and biodegradation of solid and liquid mixtures of meat industry wastes

Energy Technology Data Exchange (ETDEWEB)

Marcos, A.; Al-Kassir, A.; Cuadros, F.; Lopez-Rodriguez, F. [School of Engineering, University of Extremadura, Avda. De Elva, s/n, 06071, Badajoz (Spain); Mohamad, A.A. [Department of Mechanical and Manufacturing Engineering, University of Calgary, 2500 University Dr. N.W., Calgary, Alberta (Canada)

2010-05-15

This work is devoted to determine the optimal operational conditions on the methane production as well as on the biodegradation obtained from the anaerobic codigestion of solid (fat, intestines, rumen, bowels, whiskers, etc.) and liquid (blood, washing water, manure, etc.) wastes of meat industry, particularly the ones rising from the municipal slaughterhouse of Badajoz (Spain). The experiments were performed using a 2 l capacity discontinuous digester at 38 C. The loading rate were 0.5, 1, 2, 3, and 4.5 g COD for wastewater (washing water and blood; Mixture 1), and 0.5, 1, 2, 3, and 4 g COD for the co-digestion of a mixture of 97% liquid effluent and 3% solid wastes v/v (Mixture 2) which represents the annual mean composition of the waste generated by the slaughterhouse. The maximal biodegradation rates obtained were: Mixture 1, 56.9% for a COD load of 1 g; and Mixture 2, 19.1% for a COD load of 2 g. For both mixtures, the greatest methane production was for the maximum COD load (4.5 g for Mixture 1, and 4 g for Mixture 2), at which values the amounts of methane obtained during and at the end of the co-digestion were practically indistinguishable between the two mixtures. The results will be used to design, construct, and establish the optimal operating conditions of a continuous complete-mixture biodigester. (author)

Mixed-mode chromatography with zwitterionic phosphopeptidomimetic selectors from Ugi multicomponent reaction

NARCIS (Netherlands)

Gargano, Andrea F G; Leek, Tomas; Lindner, Wolfgang; Lämmerhofer, Michael

2013-01-01

In the present contribution a novel Ugi multicomponent reaction (MCR) was used to generate zwitterionic chromatographic selectors with capability for application in mixed-mode chromatography featuring complementary selectivities in reversed-phase (RP) and hydrophilic interaction liquid

Numerical simulations of multicomponent evaporation and gas-phase transport using M{sup 2}NOTS

Energy Technology Data Exchange (ETDEWEB)

Ho, C.K. [Sandia National Laboratories, Albuquerque, NM (United States)

1995-03-01

The multiphase, multicomponent, non-isothermal simulator M{sup 2}NOTS was tested against several one-dimensional experiments. The experiments represented a through-flow limiting condition of soil venting in which air flows through the contaminated region. Predictions using M{sup 2}NOTS of changing in situ compositions and effluent concentrations for toluene and o-xylene mixtures were compared to the observed results. Results showed that M{sup 2}NOTS was able to capture the salient trends and features of multicomponent through-flow venting processes.

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

International Nuclear Information System (INIS)

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

2012-01-01

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

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

DEFF Research Database (Denmark)

Huyghe, Raphaël; Rasmussen, Peter; Thomsen, Kaj

2004-01-01

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

Simulating multi-component liquid phase adsorption systems: ethanol and residual sugar

Energy Technology Data Exchange (ETDEWEB)

Jones, R.; Tezel, F.H.; Thibault, J. [Department of Chemical and Biological Engineering, University of Ottawa (Canada)], email: Jules.Thibault@uottawa.ca

2011-07-01

A series of multi-component adsorption studies was performed to determine the relative advantages of producing ethanol which is to be blended with gasoline. These studies developed a model to describe the competition for adsorption sites between ethanol and sugar molecules on the surface of the adsorbent. Three competitive adsorption models established by batch systems were examined to evaluate the suitability of the experiment data across different ethanol and sugar concentrations and determine their isotherm parameters. Multi-component packed bed adsorption experiments were then performed. The results show that ethanol capacity was decreased only slightly from that obtained in single component adsorption studies. There is significant evidence to indicate that sugar displacement from adsorption sites occurs because adsorption of ethanol is preferred. So the capacity of sugars will be greatly reduced if there are appreciable ethanol concentrations.

Analysis of antibiotics from liquid sample using electrospray ionization-ion mobility spectrometry

International Nuclear Information System (INIS)

Li Shu; Jia Jian; Gao Xiaoguang; He Xiuli; Li Jianping

2012-01-01

Highlights: ► The reduced mobilities of 18 antibiotics are determined. ► Establishing antibiotic mass-mobility correlation using (12,4) potential model. ► Multi-component characteristics of antibiotics can be revealed using ESI-IMS. ► Most mixtures of antibiotics can be analyzed using ESI-IMS. ► The detection limit of amoxicillin is 70 pg. - Abstract: The recent findings of antibiotic residues in aquatic environment at trace level have gained much concern for the detrimental effect on ecological and human health due to bacterial resistance. Here, the feasibility of using electrospray ionization ion mobility spectrometry (ESI-IMS) for analysis antibiotics in liquid sample is demonstrated. Reduced mobilities and collision cross sections of 18 antibiotics are experimentally measured and compared with theoretical values according to mass-mobility correlation. Gentamicin is used as an example to investigate the capability of ESI-IMS for multi-component analysis of antibiotics. Mixtures of antibiotics at different concentrations are analyzed. The estimated detection limit for amoxicillin is 0.7 mg L −1 (70 pg) and the linear range of response maintains over two orders. This method will be a potential technique for the analysis of antibiotics in aquatic environment.

Finite-deformation phase-field chemomechanics for multiphase, multicomponent solids

Science.gov (United States)

Svendsen, Bob; Shanthraj, Pratheek; Raabe, Dierk

2018-03-01

The purpose of this work is the development of a framework for the formulation of geometrically non-linear inelastic chemomechanical models for a mixture of multiple chemical components diffusing among multiple transforming solid phases. The focus here is on general model formulation. No specific model or application is pursued in this work. To this end, basic balance and constitutive relations from non-equilibrium thermodynamics and continuum mixture theory are combined with a phase-field-based description of multicomponent solid phases and their interfaces. Solid phase modeling is based in particular on a chemomechanical free energy and stress relaxation via the evolution of phase-specific concentration fields, order-parameter fields (e.g., related to chemical ordering, structural ordering, or defects), and local internal variables. At the mixture level, differences or contrasts in phase composition and phase local deformation in phase interface regions are treated as mixture internal variables. In this context, various phase interface models are considered. In the equilibrium limit, phase contrasts in composition and local deformation in the phase interface region are determined via bulk energy minimization. On the chemical side, the equilibrium limit of the current model formulation reduces to a multicomponent, multiphase, generalization of existing two-phase binary alloy interface equilibrium conditions (e.g., KKS). On the mechanical side, the equilibrium limit of one interface model considered represents a multiphase generalization of Reuss-Sachs conditions from mechanical homogenization theory. Analogously, other interface models considered represent generalizations of interface equilibrium conditions consistent with laminate and sharp-interface theory. In the last part of the work, selected existing models are formulated within the current framework as special cases and discussed in detail.

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

International Nuclear Information System (INIS)

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

2007-01-01

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

Thermodynamic properties of liquid mixtures of carbon monoxide and methane

Energy Technology Data Exchange (ETDEWEB)

Calado, J.C.G.; Guedes, H.J.R.; Nunes da Ponte, M.; Streett, W.B.

1984-04-01

Researchers conducted pressure-volume-temperature measurements of liquid methane at -230/sup 0/F and of six liquid mixtures of carbon monoxide and methane at -250/sup 0/, -240/sup 0/, and -230/sup 0/F from just above the saturation vapor pressure to the freezing pressure of methane. The excess volume proved to be large and negative at low pressures but less negative as the pressure increased, being almost zero at the highest pressure. Of the thermodynamic functions, excess enthalpy and excess entropy were much more sensitive to pressure than excess Gibbs energy. Conformal solution theory in the van der Waals one-fluid form reproduced the experimental results very successfully.

Convective boiling heat transfer of mixture of immiscible two-liquids

International Nuclear Information System (INIS)

Hijikata, K.; Ito, H.; Mori, Y.

1987-01-01

Thermal energy conversion of low or middle temperature difference to electric power is conventionally made by the Rankine cycle using the organic compound as a working fluid. However, the energy conversion efficiency from thermal energy to electric power is limited by the pinch point temperature difference in the high temperature side heat exchanging. In order to avoid the efficiency ceiling due to the pinch point temperature difference, utilization of mixture of miscible two liquids as the working fluid of the Rankine cycle has been proposed and its cycle efficiency has been calculated. However, in the miscible mixture, mutual diffusion process is considered to greatly affect the thermo-fluid characteristics, but has not been clarified yet because of its complexity

Simultaneous biodegradation of volatile and toxic contaminant mixtures by solid–liquid two-phase partitioning bioreactors

Energy Technology Data Exchange (ETDEWEB)

Poleo, Eduardo E.; Daugulis, Andrew J., E-mail: andrew.daugulis@chee.queensu.ca

2013-06-15

Highlights: • We investigate the simultaneous biodegradation of phenol and butyl acetate. • We identify an effective polymer mixture to selectively absorb each of the substrates and decrease their initial concentration. •The polymer mixture is used to overcome the high phenol cytotoxicity and reduce the abiotic losses of butyl acetate associated with volatility. • The solid–liquid Two Phase Partitioning Bioreactor (TPPB) outperforms the liquid–liquid TPPB and the single phase systems. -- Abstract: Microbial inhibition and stripping of volatile compounds are two common problems encountered in the biotreatment of contaminated wastewaters. Both can be addressed by the addition of a hydrophobic auxiliary phase that can absorb and subsequently re-release the substrates, lowering their initial aqueous concentrations. Such systems have been described as Two Phase Partitioning Bioreactors (TPPBs). In the current work the performances of a solid–liquid TPPB, a liquid–liquid TPPB and a single phase reactor for the simultaneous degradation of butyl acetate (the volatile component) and phenol (the toxic component) have been compared. The auxiliary phase used in the solid–liquid TPPB was a 50:50 polymer mixture of styrene–butadiene rubber and Hytrel{sup ®} 8206, with high affinities for butyl acetate and phenol, respectively. The liquid–liquid TPPB employed silicone oil which has fixed physical properties, and had no capacity to absorb the toxic contaminant (phenol). Butyl acetate degradation was enhanced in both TPPBs relative to the single phase, arising from its sequestration into the auxiliary phase, thereby reducing volatilization losses. The solid–liquid TPPB additionally showed a substantial increase in the phenol degradation rate, relative to the silicone oil system, demonstrating the superiority and versatility of polymer based systems.

Theory of multicomponent disordered magnets

International Nuclear Information System (INIS)

Vakarchuk, I.A.; Margolych, I.F.

1988-01-01

The method of functional integration is used to investigate a topologically disordered multicomponent system of magnetic atoms with Heisenberg exchange interaction. The partition function for a fixed random configuration of the atoms is represented as a functional integral over fluctuations of the magnetization. The first few coefficient functions are calculated in the functional series that represents the free energy functional. The magnetic part of the free energy for the liquid and amorphous states is obtained in the random phase approximation. The structure factor of the liquid magnet is calculated. For a two-component system, the nature of its variation is investigated, and so too is the shift of the point of thermodynamic instability of the liquid under the influence of a magnetic field. The Curie temperature of an amorphous two-species ferromagnet is found with allowance for the magnetic fluctuations and the topological disorder. For a model system with disorder of liquid type modeled by the structure factor of hard spheres an explicit analytic expression is calculated for the concentration dependence of the temperature of ferromagnetic ordering

Growth kinetics in multicomponent fluids

International Nuclear Information System (INIS)

Chen, S.; Lookman, T.

1995-01-01

The hydrodynamic effects on the late-stage kinetics in spinodal decomposition of multicomponent fluids are examined using a lattice Boltzmann scheme with stochastic fluctuations in the fluid and at the interface. In two dimensions, the three- and four-component immiscible fluid mixture (with a 1024 2 lattice) behaves like an off-critical binary fluid with an estimated domain growth of t 0.4 +/= 0.03 rather than t 1/3 as previously estimated, showing the significant influence of hydrodynamics. In three dimensions (with a 256 3 lattice), we estimate the growth as t 0.96 +/= 0.05 for both critical and off-critical quenches, in agreement with phenomenological theory

Phase separation temperatures of a liquid mixture: Dynamic light scattering technique

International Nuclear Information System (INIS)

Dangudom, K.; Wongtawatnugool, C.; Lacharojana, S.

2010-01-01

Light scattering intensity measurements and photon correlation spectroscopy (PCS) techniques were employed in an investigation of liquid-liquid phase separation behaviour of a mixture of cyclohexane and methanol at seven different compositions. It was found that, except for one composition (29% methanol), the temperature at which the scattering intensity was a maximum did not coincide with the one where the diffusion coefficient was a minimum, as would be for the case of a vapour-liquid system. The difference may be explained in terms of the local density fluctuation and the random walk problem responsible for the peak intensity and the minimum in the diffusion coefficient, respectively. The definition of phase separation temperature, as determined from diffusion process, was also proposed in this work.

A visual acoustic high-pressure cell for the study of critical behavior of nonsimple mixtures

Science.gov (United States)

Aguiar-Ricardo, A.; Temtem, M.; Casimiro, T.; Ribeiro, N.

2004-10-01

A visual acoustic high-pressure cell was constructed for the determination of critical data of multicomponent mixtures. The cell was specially designed to include two piezoelectric transducers and two sapphire windows that make this cell well suited to investigate the critical behavior of mixtures, simultaneously using the acoustic technique and the direct visual inspection of the critical opalescence. Critical data obtained on the binary mixtures of CO2+CHF3 were used for comparison with values given in literature using the traditional methods. The acoustic results are in agreement with those obtained by the conventional methods, within the combined experimental errors. Comparison of visual and acoustic data enabled the evaluation of the applicability of the acoustic technique to study the critical behavior of multicomponent mixtures.

Development of multicomponent parts-per-billion-level gas standards of volatile toxic organic compounds

International Nuclear Information System (INIS)

Rhoderick, G.C.; Zielinski, W.L. Jr.

1990-01-01

This paper reports that the demand for stable, low-concentration multicomponent standards of volatile toxic organic compounds for quantifying national and state measurement of ambient air quality and hazardous waste incineration emissions has markedly increased in recent years. In response to this demand, a microgravimetric technique was developed and validated for preparing such standards; these standards ranged in concentration from several parts per million (ppm) down to one part per billion (ppb) and in complexity from one organic up to 17. Studies using the gravimetric procedure to prepare mixtures of different groups of organics. including multi-components mixtures in the 5 to 20 ppb range, revealed a very low imprecision. This procedure is based on the separate gravimetric introduction of individual organics into an evacuated gas cylinder, followed by the pressurized addition of a precalculated amount of pure nitrogen. Additional studies confirmed the long-term stability of these mixtures. The uncertainty of the concentrations of the individual organics at the 95% confidence level ranged from less than 1% relative at 1 ppm to less than 10% relative at 1 ppb. Over 100 primary gravimetric standards have been developed, validated, and used for certifying the concentrations of a variety of mixtures for monitoring studies

Simulation on a proposed large-scale liquid hydrogen plant using a multi-component refrigerant refrigeration system

Energy Technology Data Exchange (ETDEWEB)

Krasae-in, Songwut [Norwegian University of Science and Technology, Kolbjorn Hejes vei 1d, NO-7491 Trondheim (Norway); Stang, Jacob H.; Neksa, Petter [SINTEF Energy Research AS, Kolbjorn Hejes vei 1d, NO-7465 Trondheim (Norway)

2010-11-15

A proposed liquid hydrogen plant using a multi-component refrigerant (MR) refrigeration system is explained in this paper. A cycle that is capable of producing 100 tons of liquid hydrogen per day is simulated. The MR system can be used to cool feed normal hydrogen gas from 25 C to the equilibrium temperature of -193 C with a high efficiency. In addition, for the transition from the equilibrium temperature of the hydrogen gas from -193 C to -253 C, the new proposed four H{sub 2} Joule-Brayton cascade refrigeration system is recommended. The overall power consumption of the proposed plant is 5.35 kWh/kg{sub LH2}, with an ideal minimum of 2.89 kWh/kg{sub LH2}. The current plant in Ingolstadt is used as a reference, which has an energy consumption of 13.58 kWh/kg{sub LH2} and an efficiency of 21.28%: the efficiency of the proposed system is 54.02% or more, where this depends on the assumed efficiency values for the compressors and expanders. Moreover, the proposed system has some smaller-size heat exchangers, much smaller compressor motors, and smaller crankcase compressors. Thus, it could represent a plant with the lowest construction cost with respect to the amount of liquid hydrogen produced in comparison to today's plants, e.g., in Ingolstadt and Leuna. Therefore, the proposed system has many improvements that serve as an example for future hydrogen liquefaction plants. (author)

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

Science.gov (United States)

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

2015-10-14

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

Refractive indices of ternary liquid mixtures containing aliphatic alcohols at several temperatures

Directory of Open Access Journals (Sweden)

Sovilj Milan N.

2005-01-01

Full Text Available The refractive indices of ternary liquid mixtures (2-propanol+2-butanol+ethanol and (chloroform+2-propanol+2-butanol were measured at 20, 25, 30, and 35°C, and atmospheric pressure. The results were used to calculate the refractive index deviations over the entire mole fraction range for the mixtures. The refractive index deviations for the ternary mixtures were further fitted to empirical correlations (Cibulka Nagata-Tamura, and Lopez et al to estimate the ternary fitting parameters. Standard deviations and average percentage deviations from the regression lines are shown. The best fit was obtained by the Nagata-Tamura empirical correlation. Some of the existing predictive equations for the refractive index deviations (Tsao-Smith, Köhler, and Colinet were tested.

Topological defects in mixtures of superconducting condensates with different charges

Science.gov (United States)

Garaud, Julien; Babaev, Egor

2014-06-01

We investigate the topological defects in phenomenological models describing mixtures of charged condensates with commensurate electric charges. Such situations are expected to appear for example in liquid metallic deuterium. This is modeled by a multicomponent Ginzburg-Landau theory where the condensates are coupled to the same gauge field by different coupling constants whose ratio is a rational number. We also briefly discuss the case where electric charges are incommensurate. Flux quantization and finiteness of the energy per unit length dictate that the different condensates have different winding and thus different number of (fractional) vortices. Competing attractive and repulsive interactions lead to molecule-like bound states between fractional vortices. Such bound states have finite energy and carry integer flux quanta. These can be characterized by the CP1 topological invariant that motivates their denomination as skyrmions.

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

International Nuclear Information System (INIS)

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

2012-01-01

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

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

International Nuclear Information System (INIS)

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

2016-01-01

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

(Liquid + liquid) equilibrium at T = 298.15 K for ternary mixtures of alkane + aromatic compounds + imidazolium-based ionic liquids

International Nuclear Information System (INIS)

Domínguez, Irene; Requejo, Patricia F.; Canosa, José; Domínguez, Ángeles

2014-01-01

Highlights: • The LLE ternary phase diagrams with 2 imidazolium-based ionic liquids were measured. • The LLE data were experimental determined at T = 298.15 K and p = 1 atm. • Mixtures of (octane or nonane) and (benzene or toluene or ethylbenzene) were studied. • LLE experimental data were correlated with NRTL and UNIQUAC thermodynamic models. - Abstract: Ionic liquids, with their unique and tunable properties, can be an advantageous alternative as extractive solvents in separation processes involving systems containing aliphatic and aromatic hydrocarbons. In this work, (liquid + liquid) equilibrium (LLE) data for the ternary systems {nonane (1) + benzene (2) + 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [BMim][NTf 2 ] (3)}, {octane (1) + benzene (2) + 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, [PMim][NTf 2 ] (3)}, and {nonane (1) + aromatic compound (benzene or toluene or ethylbenzene) (2) + [PMim][NTf 2 ] (3)} were determined at T = 298.15 K and atmospheric pressure. Selectivity and solute distribution ratio, derived from the equilibrium data, were used to determine if this ionic liquid can be considered as a potential solvent for the separation of aromatic compounds (benzene, toluene, and ethylbenzene) from alkanes (octane and nonane). The experimental data were satisfactorily correlated with NRTL and UNIQUAC models

In situ liquid-liquid extraction as a sample preparation method for matrix-assisted laser desorption/ionization MS analysis of polypeptide mixtures

DEFF Research Database (Denmark)

Kjellström, Sven; Jensen, Ole Nørregaard

2003-01-01

A novel liquid-liquid extraction (LLE) procedure was investigated for preparation of peptide and protein samples for matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). LLE using ethyl acetate as the water-immiscible organic solvent enabled segregation of hydrophobic...... matrix to the organic solvent enhanced the efficiency of the LLE-MALDI MS method for analysis of hydrophobic peptides and proteins. LLE-MALDI MS enabled the detection of the hydrophobic membrane protein bacteriorhodopsin as a component in a simple protein mixture. Peptide mixtures containing...... phosphorylated, glycosylated, or acylated peptides were successfully separated and analyzed by the in situ LLE-MALDI MS technique and demonstrate the potential of this method for enhanced separation and structural analysis of posttranslationally modified peptides in proteomics research....

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

Science.gov (United States)

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

2018-03-01

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

Prediction of vapour-liquid equilibria for the kinetic study of processes based on synthesis gas

Energy Technology Data Exchange (ETDEWEB)

Di Serio, M.; Tesser, R.; Cozzolino, M.; Santacesaria, E. [Naples Univ., Napoli (Italy). Dept. of Chemistry

2006-07-01

Syngas is normally used in the production of a broad range of chemicals and fuels. In many of these processes multiphase reactors, gas-liquid or gas-liquid-solid are used. Kinetic studies in multiphase systems are often complicated by the non-ideal behaviour of reagents and/or products that are consistently partitioned between the liquid and the vapour phase. Moreover, as often kinetic data are collected in batch conditions for the liquid phase, activity coefficients of the partitioned components can consistently change during the time as a consequence of changing the composition of the reaction mixture. Therefore, it is necessary, in these cases, to known the vapor-liquid equilibria (VLE) in order to collect and to interpret correctly the kinetic data. The description of phase equilibria, at high pressures, is usually performed by means of an EOS (Equation of State) allowing the calculation of fugacity coefficients, for each component, in both phases and determining the partition coefficients but the EOS approach involves the experimental determination of the interaction parameters for all the possible binary system of the mixture. For multicomponent mixtures a complete experimental determination of vapourliquid equilibria is very hard, also considering the high pressure and temperatures used. Some predictive group contribution methods have been recently developed. In this paper, we will describe in detail the application of these methods to the methanol homologation, as an example, with the scope of determining more reliable kinetic parameters for this reaction. (orig.)

Application of High-Resolution Ultrasonic Spectroscopy for analysis of complex formulations. Compressibility of solutes and solute particles in liquid mixtures

International Nuclear Information System (INIS)

Buckin, V

2012-01-01

The paper describes key aspects of interpretation of compressibility of solutes in liquid mixtures obtained through high-resolution measurements of ultrasonic parameters. It examines the fundamental relationships between the characteristics of solutes and the contributions of solutes to compressibility of liquid mixtures expressed through apparent adiabatic compressibility of solutes, and adiabatic compressibility of solute particles. In addition, it analyses relationships between the adiabatic compressibility of solutes and the measured ultrasonic characteristics of mixtures. Especial attention is given to the effects of solvents on the measured adiabatic compressibility of solutes and on concentration increment of ultrasonic velocity of solutes in mixtures.

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

NARCIS (Netherlands)

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

1991-01-01

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

The study of different methods of bio-liquids production from wood biomass and from biomass/polyolefine mixtures

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, B.N. [Institute of Chemistry and Chemical Technology, Siberian Branch, Russian Academy of Sciences, 660049 Krasnoyarsk, K. Marx str., 42 (Russian Federation); Siberian Federal University, Svobodny, 79, 660041 Krasnoyarsk (Russian Federation); Sharypov, V.I.; Kuznetsova, S.A.; Taraban' ko, V.E.; Ivanchenko, N.M. [Institute of Chemistry and Chemical Technology, Siberian Branch, Russian Academy of Sciences, 660049 Krasnoyarsk, K. Marx str., 42 (Russian Federation)

2009-08-15

The different methods of wood biomass thermal liquefaction at atmospheric and elevated pressures were investigated in order to select the more effective one. Wood biomass liquefaction by melted formate/alkali mixtures and with the use of metallic iron/Na{sub 2}CO{sub 3} system is carried out at low pressures. But these methods give only moderate yield of bio-liquids. The highest yield of bio-liquid was obtained in the process of biomass dissolvation in methanol media in the presence of Zn-Cr-Fe catalyst at 20 MPa. Co-pyrolysis and co-hydropyrolysis of biomass/polyolefine mixtures makes it possible to obtain the rather high yield of bio-liquid at the moderate pressures (3 MPa). (author)

A multi-component matrix loop algebra and a unified expression of the multi-component AKNS hierarchy and the multi-component BPT hierarchy

International Nuclear Information System (INIS)

Zhang Yufeng

2005-01-01

A set of multi-component matrix Lie algebra is constructed, which is devote to obtaining a new loop algebra A-bar M-1 . It follows that an isospectral problem is established. By making use of Tu scheme, a Liouville integrable multi-component hierarchy of soliton equations is generated, which possesses the bi-Hamiltonian structures. As its reduction cases, the multi-component AKNS hierarchy and the formalism of the multi-component BPT hierarchy are given, respectively

Two-phase mixture level swell and liquid entrainment/off-take in a vessel during rapid depressurization

International Nuclear Information System (INIS)

Kim, Chang Hyun

2004-02-01

An experimental study has been performed to analyze the two-phase mixture level swell and the liquid entrainment/off-take through the break in a vessel, which are important phenomena to determine the bleed capacity of the Safety Depressurization System (SDS) of Korea Advanced Power Reactor 1400 (APR1400). Three separate experiments are performed in this study: (a) the depressurization and two-phase mixture level swell experiment: (b) the two-phase mixture level measurement experiment: (c) the liquid entrainment and off-take experiment. A series of experiments has been performed using a scaled pressurized vessel in various depressurization conditions to analyze the two-phase mixture level swell and the liquid entrainment/off-take phenomena from the two-phase mixture surface in the first experiment. The test parameters are the initial pressure (10 - 38.75bars), the initial water level (43.7% - 80.0% of full height), the orifice inner diameter (10mm, 17.5mm, and 20mm). The liquid off-take takes place in certain experimental conditions. The measured parameters in the present experiments are axial void fraction distributions, pressures, temperatures in the test vessel, and the mixture density and mass flowrate through the discharge pipe. An assessment of RELAP5/MOD3 code with the present experimental data has been performed. With appropriate nodalization and time step, RELAP5/MOD3 showed reasonable agreement with the present experimental data for the gradual depressurization without liquid off-take. In the case that the off-take takes place, however, RELAP5/MOD3 under-predicts the amount of liquid entrainment/off-take during depressurization. In the second experiment, an assessment of an ultrasonic sensor and a two-wire type capacitance probe for the two-phase mixture level measurement has been performed under the same experimental conditions to adopt an appropriate measurement method for the two-phase mixture level swell and to investigate pool void fraction by the

Analysis of antibiotics from liquid sample using electrospray ionization-ion mobility spectrometry

Energy Technology Data Exchange (ETDEWEB)

Shu, Li; Jian, Jia; Xiaoguang, Gao; Xiuli, He [State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China); Li Jianping, E-mail: jpli@mail.ie.ac.cn [State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)

2012-03-30

Highlights: Black-Right-Pointing-Pointer The reduced mobilities of 18 antibiotics are determined. Black-Right-Pointing-Pointer Establishing antibiotic mass-mobility correlation using (12,4) potential model. Black-Right-Pointing-Pointer Multi-component characteristics of antibiotics can be revealed using ESI-IMS. Black-Right-Pointing-Pointer Most mixtures of antibiotics can be analyzed using ESI-IMS. Black-Right-Pointing-Pointer The detection limit of amoxicillin is 70 pg. - Abstract: The recent findings of antibiotic residues in aquatic environment at trace level have gained much concern for the detrimental effect on ecological and human health due to bacterial resistance. Here, the feasibility of using electrospray ionization ion mobility spectrometry (ESI-IMS) for analysis antibiotics in liquid sample is demonstrated. Reduced mobilities and collision cross sections of 18 antibiotics are experimentally measured and compared with theoretical values according to mass-mobility correlation. Gentamicin is used as an example to investigate the capability of ESI-IMS for multi-component analysis of antibiotics. Mixtures of antibiotics at different concentrations are analyzed. The estimated detection limit for amoxicillin is 0.7 mg L{sup -1} (70 pg) and the linear range of response maintains over two orders. This method will be a potential technique for the analysis of antibiotics in aquatic environment.

Efficient numerical methods for simulating surface tension of multi-component mixtures with the gradient theory of fluid interfaces

KAUST Repository

Kou, Jisheng

2015-08-01

Surface tension significantly impacts subsurface flow and transport, and it is the main cause of capillary effect, a major immiscible two-phase flow mechanism for systems with a strong wettability preference. In this paper, we consider the numerical simulation of the surface tension of multi-component mixtures with the gradient theory of fluid interfaces. Major numerical challenges include that the system of the Euler-Lagrange equations is solved on the infinite interval and the coefficient matrix is not positive definite. We construct a linear transformation to reduce the Euler-Lagrange equations, and naturally introduce a path function, which is proven to be a monotonic function of the spatial coordinate variable. By using the linear transformation and the path function, we overcome the above difficulties and develop the efficient methods for calculating the interface and its interior compositions. Moreover, the computation of the surface tension is also simplified. The proposed methods do not need to solve the differential equation system, and they are easy to be implemented in practical applications. Numerical examples are tested to verify the efficiency of the proposed methods. © 2014 Elsevier B.V.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

The application of experimental design methodology for the investigation of liquid radioactive waste treatment

Directory of Open Access Journals (Sweden)

Šljivić-Ivanović Marija Z.

2017-01-01

Full Text Available The sorption properties of waste facade, brick, and asphalt sample towards Sr(II, Co(II, and Ni(II ions from single and multicomponent solutions were investigated. The highest sorption capacity was found for Ni(II ions, while the most effective sorbent was facade. Simplex Centroid Mixture Design was used in order to investigate the sorption processes of ions from solutions with different composition as well as the competition between the cations. Based on the statistical analysis results, the equations for data modeling were proposed. According to the observations, the investigated solid matrices can be effectively used for the liquid radioactive waste treatment. Furthermore, the applied methodology turned out to be an easy and operational way for the investigations of multicomponent sorption processes. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 43009 and Grant no. OI 171007

Structure and lifetimes in ionic liquids and their mixtures.

Science.gov (United States)

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

2018-01-01

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

Composition shift in liquid-recirculation refrigerating systems: an experimental investigation for the pure fluid R134a and the mixture R32/134a

Energy Technology Data Exchange (ETDEWEB)

Giuliani, G.; Marchesi Donati, F.; Polonara, F. [Ancona Univ. (Italy). Dip. di Energetica; Hewitt, N.J. [University of Ulster at Coleraine, Northern Ireland (United Kingdom). NICERT

1999-09-01

The ability of zeotropic mixtures with a remarkable temperature glide to operate in liquid-recirculation systems is investigated and the results of an experimental comparison between the performances of the pure fluid R134a and the zeotropic mixture R32/134a (25/75% by mass) are presented. R134a performs slightly better in the liquid-recirculation mode than in the traditional dry-expansion mode; on the other hand, liquid-recirculation configuration has a detrimental effect on the zeotropic mixture's performance. The reason for this detrimental effect is the mixture component separation which occurs at the liquid/vapor separator. The effect of this separation is investigated using gas chromatograph analysis.

Adsorption of gas mixtures on heterogeneous solid surfaces

Energy Technology Data Exchange (ETDEWEB)

Jaroniec, M; Rudzinski, W

1977-01-01

A review of theoretical studies on the physical adsorption from gas mixtures on heterogeneous solid surfaces, mainly by Jaroniec and coworkers, covers the vector notation used in the calculations; adsorption isotherms for multicomponent gases; the generalized integral equation for adsorption of gas mixtures, its numerical and analytical solutions, applied, (e.g., to interpret the experimental adsorption isotherms of ethane/ethylene on Nuxit-AL); thermodynamic relations, applied, (e.g., to calculating isosteric adsorption heats from experimental parameters for the adsorption of propylene from propane/propylene mixtures on Nuxit-AL); and the derivation and use of a simplified integral equation for describing the adsorption from gas mixtures on heterogeneous surfaces. 75 references.

Composition tailoring in the Ce-doped multicomponent garnet epitaxial film scintillators

Czech Academy of Sciences Publication Activity Database

Průša, Petr; Kučera, M.; Mareš, Jiří A.; Onderišinová, Z.; Hanuš, M.; Babin, Vladimir; Beitlerová, Alena; Nikl, Martin

2015-01-01

Roč. 15, č. 8 (2015), s. 3715-3723 ISSN 1528-7483 R&D Projects: GA ČR GAP204/12/0805 Institutional support: RVO:68378271 Keywords : scintillation * liquid phase epitaxy * photoelectron yield * Ce 3+ * multicomponent garnet Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.425, year: 2015

[Theoretical modeling and experimental research on direct compaction characteristics of multi-component pharmaceutical powders based on the Kawakita equation].

Science.gov (United States)

Si, Guo-Ning; Chen, Lan; Li, Bao-Guo

2014-04-01

Base on the Kawakita powder compression equation, a general theoretical model for predicting the compression characteristics of multi-components pharmaceutical powders with different mass ratios was developed. The uniaxial flat-face compression tests of powder lactose, starch and microcrystalline cellulose were carried out, separately. Therefore, the Kawakita equation parameters of the powder materials were obtained. The uniaxial flat-face compression tests of the powder mixtures of lactose, starch, microcrystalline cellulose and sodium stearyl fumarate with five mass ratios were conducted, through which, the correlation between mixture density and loading pressure and the Kawakita equation curves were obtained. Finally, the theoretical prediction values were compared with experimental results. The analysis showed that the errors in predicting mixture densities were less than 5.0% and the errors of Kawakita vertical coordinate were within 4.6%, which indicated that the theoretical model could be used to predict the direct compaction characteristics of multi-component pharmaceutical powders.

A quantum mechanical strategy to investigate the structure of liquids: the cases of acetonitrile, formamide, and their mixture.

Science.gov (United States)

Mennucci, Benedetta; da Silva, Clarissa O

2008-06-05

A computational strategy based on quantum mechanical (QM) calculations and continuum solvation models is used to investigate the structure of liquids (either neat liquids or mixtures). The strategy is based on the comparison of calculated and experimental spectroscopic properties (IR-Raman vibrational frequencies and Raman intensities). In particular, neat formamide, neat acetonitrile, and their equimolar mixture are studied comparing isolated and solvated clusters of different nature and size. In all cases, the study seems to indicate that liquids, even when strongly associated, can be effectively modeled in terms of a shell-like system in which clusters of strongly interacting molecules (the microenvironments) are solvated by a polarizable macroenvironment represented by the rest of the molecules. Only taking into proper account both these effects can a correct picture of the liquid structure be achieved.

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Effect of the oxygen balance on ignition and detonation properties of liquid explosive mixtures

International Nuclear Information System (INIS)

Genetier, M; Osmont, A; Baudin, G

2014-01-01

The objective is to compare the ignition and detonation properties of various liquid high explosives having negative up to positive oxygen balance (OB): nitromethane (OB < 0), saccharose and hydrogen peroxide based mixture (quasi nil OB), hydrogen peroxide with more than 90% purity (OB > 0). The decomposition kinetic rates and the equations of state (EOS) for the liquid mixtures and detonation products (DP) are the input data for a detonation model. EOS are theoretically determined using the Woolfolk et al. universal liquid polar shock law and thermochemical computations for DP. The decomposition kinetic rate laws are determined to reproduce the shock to detonation transition for the mixtures submitted to planar plate impacts. Such a model is not sufficient to compute open field explosions. The aerial overpressure is well reproduced in the first few microseconds, however, after it becomes worse at large expansion of the fireball and the impulse is underestimated. The problem of the DP EOS alone is that it takes only the detonation into account, the secondary combustion DP – air is not considered. To solve this problem a secondary combustion model has been developed to take the OB effect into account. The detonation model has been validated on planar plate impact experiments. The secondary combustion parameters were deduced from thermochemical computations. The whole model has been used to predict the effects of the oxygen balance on open air blast effects of spherical charges.

Energy saving in multicomponent separation using an internally heat-integrated distillation column (HIDiC)

Energy Technology Data Exchange (ETDEWEB)

Iwakabe, Koichi [Department of Chemical Engineering, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro, Tokyo 152-8552 (Japan); Nakaiwa, Masaru; Huang, Kejin; Ohmori, Takao; Endo, Akira; Yamamoto, Takuji [Energy-Efficient Chemical Systems Group, Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1, Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Nakanishi, Toshinari [R and D Department, Kimura Chemical Plants Co., Ltd, 2-1-2, Terajima Kuise, Amagasaki, Hyogo 660-8567 (Japan); Roesjorde, Audun [Department of Chemistry, Norwegian University of Science and Technology, 7491 Tronheim (Norway)

2006-09-15

Energy savings by an internally heat-integrated distillation column (HIDiC) for the separation of multicomponent mixtures were studied. The design and the operating variables of a HIDiC were defined for this purpose, and were systematically varied to carry out a sensitivity analysis. Benzene-toluene-p-xylene (BTX) mixture and 12-component hydrocarbons (12HC) mixture were chosen as model systems. Sensitivity analysis showed that the HIDiC is able to reduce energy consumption by about 30% for the BTX system and an even better 50% for the 12HC system. The effects on energy consumption of the design and the operating variables were also examined. (author)

Experimental and predicted refractive index properties in ternary mixtures of associated liquids

International Nuclear Information System (INIS)

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

2011-01-01

Highlights: → Measurements of refractive indices of 200 different aqueous ternary mixtures have been performed for two wave lengths. → Refractive indices of the associated ternary mixtures can be modeled with a relative error of about 0.9. → Difference between experimental and calculated derivatives of refractive index with concentration is unsatisfactory large. - Abstract: Refractive indices of ternary mixtures formed by (water + ethanol + k-ethylene glycol) (when k is mono, di or tri) and (water + t-butanol + dimethyl sulfoxide) are presented over a wide range of mixture compositions. All measurements have been conducted at 298.15 K and atmospheric pressure using two light sources: one in the visible (λ = 670 nm) and the other in the infrared (λ = 925 nm) spectrum. The performance of several mixing rules that are commonly used in modeling optical constants are examined. We demonstrate that the refractive indices of the associated ternary mixtures can be modeled with a relative error of about 0.9% by using the thermodynamical properties of the pure components. The concentration derivatives of the refractive index are an important parameter, as they are required for different experimental techniques. These derivatives have been determined from the experimental data on refractive indices. However, applying mixing rules for calculation of the derivatives of the refractive indices with respect to concentrations does not provide satisfactory results in the case of ternary mixtures of associated liquids.

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

Science.gov (United States)

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

2018-05-01

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

Diffusion of Charged Species in Liquids

Science.gov (United States)

Del Río, J. A.; Whitaker, S.

2016-11-01

In this study the laws of mechanics for multi-component systems are used to develop a theory for the diffusion of ions in the presence of an electrostatic field. The analysis begins with the governing equation for the species velocity and it leads to the governing equation for the species diffusion velocity. Simplification of this latter result provides a momentum equation containing three dominant forces: (a) the gradient of the partial pressure, (b) the electrostatic force, and (c) the diffusive drag force that is a central feature of the Maxwell-Stefan equations. For ideal gas mixtures we derive the classic Nernst-Planck equation. For liquid-phase diffusion we encounter a situation in which the Nernst-Planck contribution to diffusion differs by several orders of magnitude from that obtained for ideal gases.

Measurements of mixtures with carbon dioxide under supercritical conditions using commercial high pressure equipment

Energy Technology Data Exchange (ETDEWEB)

Andrade, Luciana L.P.R. de; Rutledge, Luis Augusto Medeiros; Moreno, Eesteban L.; Hovell, Ian; Rajagopal, Krishnaswamy [Universidade Federal do Rio de Janeiro (LATCA-EQ-UFRJ), RJ (Brazil). Escola de Quimica. Lab. de Termodinamica e Cinetica Aplicada

2012-07-01

There is a growing interest in studying physical properties of binary and multicomponent fluid mixtures with supercritical carbon dioxide (CO{sub 2}) over an extended range of temperature and pressure. The estimation of properties such as density, viscosity, saturation pressure, compressibility, solubility and surface tension of mixtures is important in design, operation and control as well as optimization of chemical processes especially in extractions, separations, catalytic and enzymatic reactions. The phase behaviour of binary and multicomponent mixtures with supercritical CO{sub 2} is also important in the production and refining of petroleum where mixtures of paraffin, naphthene and aromatics with supercritical fluids are often encountered. Petroleum fluids can present a complex phase behaviour in the presence of CO{sub 2}, where two-phase (VLE and LLE) and three phase regions (VLLE) might occur within ranges of supercritical conditions of temperature and pressure. The objective of this study is to develop an experimental methodology for measuring the phase behaviour of mixtures containing CO{sub 2} in supercritical regions, using commercial high-pressure equipment. (author)

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

International Nuclear Information System (INIS)

Woywod, Dirk; Schoen, Martin

2004-01-01

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

Vapor-liquid critical surface of ternary difluoromethane + pentafluoroethane + 1,1,1,2-tetrafluoroethane (R-32/125/134a) mixtures

Energy Technology Data Exchange (ETDEWEB)

Higashi, Y.

1999-09-01

The plane of vapor-liquid criticality for ternary refrigerant mixtures of difluoromethane (R-32) + pentafluoroethane (R-125) + 1,1,1,2-tetrafluoroethane (R-134a) was determined from data on the vapor-liquid coexistence curve near the mixture critical points. The composition (mass percentage) of the mixtures studied were 23% R-32 + 25% R-125 + 52% R-134a (R-407C). 25% R-32 + 15% R-125 + 60% R-134a (R-407E), and 20% R-32 + 40% R-125 + 40% R-134a (R-407A). The critical temperature of each mixture was determined by observation of the disappearance of the meniscus. The critical density of each mixture was determined on the basis of meniscus disappearance level and the intensity of the critical opalescence. The uncertainties of the temperature, density, and composition measurements are estimated as {+-}10mK, {+-}5kg{center_dot}m{sup {minus}3}, and {+-}0.05%, respectively. In addition, predictive methods for the critical parameters of R-32/125/134a mixtures are discussed.

Modeling adsorption of binary and ternary mixtures on microporous media

DEFF Research Database (Denmark)

Monsalvo, Matias Alfonso; Shapiro, Alexander

2007-01-01

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

Performance test of multicomponent quantum mechanical calculation with polarizable continuum model for proton chemical shift.

Science.gov (United States)

Kanematsu, Yusuke; Tachikawa, Masanori

2015-05-21

Multicomponent quantum mechanical (MC_QM) calculations with polarizable continuum model (PCM) have been tested against liquid (1)H NMR chemical shifts for a test set of 80 molecules. Improvement from conventional quantum mechanical calculations was achieved for MC_QM calculations. The advantage of the multicomponent scheme could be attributed to the geometrical change from the equilibrium geometry by the incorporation of the hydrogen nuclear quantum effect, while that of PCM can be attributed to the change of the electronic structure according to the polarization by solvent effects.

Thermally excited capillary waves at vapor/liquid interfaces of water-alcohol mixtures

International Nuclear Information System (INIS)

Vaknin, David; Bu Wei; Sung, Jaeho; Jeon, Yoonnam; Kim, Doseok

2009-01-01

The density profiles of liquid/vapor interfaces of water-alcohol (methanol, ethanol and propanol) mixtures were studied by surface-sensitive synchrotron x-ray scattering techniques. X-ray reflectivity and diffuse scattering measurements, from the pure and mixed liquids, were analyzed in the framework of capillary wave theory to address the characteristic length scales of the intrinsic roughness and the shortest capillary wavelength (alternatively, the upper wavevector cutoff in capillary wave theory). Our results establish that the intrinsic roughness is dominated by average interatomic distances. The extracted effective upper wavevector cutoff indicates capillary wave theory breaks down at distances of the order of bulk correlation lengths.

Scaling Properties of Spectra in New Exact Solutions of Rotating, Multi-Component Fireball Hydrodynamics

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Tamás Csörgő

2018-03-01

Full Text Available We describe fireballs that rehadronize from a perfect fluid of quark matter, characterized by the lattice QCD equation of state, to a chemically frozen, multi-component mixture, that contains various kinds of observable hadrons. For simplicity and clarity, we apply a non-relativistic approximation to describe the kinematics of this expansion. Unexpectedly, we identify a secondary explosion that may characterize fireball hydrodynamics at the QCD critical point. After rehadronization, the multi-component mixture of hadrons keeps on rotating and expanding together, similarly to a single component fluid. After kinetic freeze-out, the effective temperature T i of the single-particle spectra of hadron type h i is found to be a sum of the kinetic freeze-out temperature T f (that is independent of the hadron type h i and a term proportional to the mass m i of hadron type h i . The coefficient of proportionality to m i is found to be independent of the hadron type h i but to be dependent on the radial flow and vorticity of collective dynamics.

CuInS2/ZnS QD-ferroelectric liquid crystal mixtures for faster electro-optical devices and their energy storage aspects

Science.gov (United States)

Singh, Dharmendra Pratap; Vimal, Tripti; Mange, Yatin J.; Varia, Mahesh C.; Nann, Thomas; Pandey, K. K.; Manohar, Rajiv; Douali, Redouane

2018-01-01

CuInS2/ZnS core/shell quantum dots (CIS/ZnS QDs) dispersed ferroelectric liquid crystal (FLC) mixtures have been characterized for their application in electro-optical devices, energy storage, and solar cells. Physical properties of the CIS/ZnS QD-FLC (ferroelectric liquid crystal) mixtures have also been investigated with varying QD concentrations in order to optimize the critical concentration of QDs in mixtures. The presence of QDs breaks the geometrical symmetry in the FLC matrix, which results in a change in the physical properties of the mixtures. We observed the reduced values of primary and secondary order parameters (tilt angle and spontaneous polarization, respectively) for mixtures, which also depend on the concentration of QDs. The reduction of spontaneous polarization in QDs-FLC mixtures is attributed to the adverse role of flexoelectric contribution in the mixtures. The 92% faster electro-optic response and enhanced capacitance indicate the possible application of these mixtures in electro-optical devices and solar cells. Photoluminescence emission of pure FLC and QDs-FLC mixtures has been thermally tailored, which is explained by suitable models.

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-03-28

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

Bubble and Dew Point Calculations in Multicomponent and Multireactive Mixtures

OpenAIRE

Bonilla-Petriciolet, A.; Acosta-Martínez, A.; Bravo-Sánchez, U. I.; Segovia-Hernández, J. G.

2006-01-01

Bubble and dew point calculations are useful in chemical engineering and play an important role in the study of separation equipments for non-reactive and reactive mixtures. To the best of the authors’s knowledge, few methods have been proposed for these calculations in systems with several chemical reactions. The objective of this paper is to introduce new conditions for performing bubble and dew point calculations in reactive mixtures. We have developed these conditions based on the a...

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

Science.gov (United States)

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

2008-02-28

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-01-15

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

Correlation of vapor - liquid equilibrium data for acetic acid - isopropanol - water - isopropyl acetate mixtures

Directory of Open Access Journals (Sweden)

B. A. Mandagarán

2006-03-01

Full Text Available A correlation procedure for the prediction of vapor - liquid equilibrium of acetic acid - isopropanol - water - isopropyl acetate mixtures has been developed. It is based on the NRTL model for predicting liquid activity coefficients, and on the Hayden-O'Connell second virial coefficients for predicting the vapor phase of systems containing association components. When compared with experimental data the correlation shows a good agreement for binary and ternary data. The correlation also shows good prediction for reactive quaternary data.

Construction of Lines of Constant Density and Constant Refractive Index for Ternary Liquid Mixtures.

Science.gov (United States)

Tasic, Aleksandar Z.; Djordjevic, Bojan D.

1983-01-01

Demonstrates construction of density constant and refractive index constant lines in triangular coordinate system on basis of systematic experimental determinations of density and refractive index for both homogeneous (single-phase) ternary liquid mixtures (of known composition) and the corresponding binary compositions. Background information,…

On a partial differential equation method for determining the free energies and coexisting phase compositions of ternary mixtures from light scattering data.

Science.gov (United States)

Ross, David S; Thurston, George M; Lutzer, Carl V

2008-08-14

In this paper we present a method for determining the free energies of ternary mixtures from light scattering data. We use an approximation that is appropriate for liquid mixtures, which we formulate as a second-order nonlinear partial differential equation. This partial differential equation (PDE) relates the Hessian of the intensive free energy to the efficiency of light scattering in the forward direction. This basic equation applies in regions of the phase diagram in which the mixtures are thermodynamically stable. In regions in which the mixtures are unstable or metastable, the appropriate PDE is the nonlinear equation for the convex hull. We formulate this equation along with continuity conditions for the transition between the two equations at cloud point loci. We show how to discretize this problem to obtain a finite-difference approximation to it, and we present an iterative method for solving the discretized problem. We present the results of calculations that were done with a computer program that implements our method. These calculations show that our method is capable of reconstructing test free energy functions from simulated light scattering data. If the cloud point loci are known, the method also finds the tie lines and tie triangles that describe thermodynamic equilibrium between two or among three liquid phases. A robust method for solving this PDE problem, such as the one presented here, can be a basis for optical, noninvasive means of characterizing the thermodynamics of multicomponent mixtures.

From Trioleoyl glycerol to extra virgin olive oil through multicomponent triacylglycerol mixtures: Crystallization and polymorphic transformation examined with differential scanning calorimetry and X-ray diffration techniques.

Science.gov (United States)

Bayés-García, L; Calvet, T; Cuevas-Diarte, M A; Ueno, S

2017-09-01

The polymorphic crystallization and transformation behavior of extra virgin olive oil (EVOO) was examined by using differential scanning calorimetry (DSC) and X-ray diffraction with both laboratory-scale (XRD) and synchrotron radiation source (SR-XRD). The complex behavior observed was studied by previously analyzing mixtures composed by its main 2 to 6 triacylglycerol (TAG) components. Thus, component TAGs were successively added to simulate EVOO composition, until reaching a 6 TAGs mixture, composed by trioleoyl glycerol (OOO), 1-palmitoyl-2,3-dioleoyl glycerol (POO), 1,2-dioleoyl-3-linoleoyl glycerol (OOL), 1-palmitoyl-2-oleoyl-3-linoleoyl glycerol (POL), 1,2-dipalmitoyl-3-oleoyl glycerol (PPO) and 1-stearoyl-2,3-dioleoyl glycerol (SOO). Molten samples were cooled from 25°C to -80°C at a controlled rate of 2°C/min and subsequently heated at the same rate. The polymorphic behavior observed in multicomponent TAG mixtures was interpreted by considering three main groups of TAGs with different molecular structures: triunsaturated OOO and OOL, saturated-unsaturated-unsaturated POO, POL and SOO, and saturated-saturated-unsaturated PPO. As confirmed by our previous work, TAGs belonging to the same structural group displayed a highly similar polymorphic behavior. EVOO exhibited two different β'-2L polymorphic forms (β' 2 -2L and β' 1 -2L), which transformed into β'-3L when heated. Equivalent polymorphic pathways were detected when the same experimental conditions were applied to the 6 TAG components mixture. Hence, minor components may not exert a strong influence in this case. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental study of single taylor bubbles rising in stagnant liquid mixtures inside of vertical tubes

International Nuclear Information System (INIS)

Azevedo, Marcos B. de; Faccini, Jose L.H.; Su, Jian

2015-01-01

The present work reports an experimental study of single Taylor bubbles rising in vertical tubes filled with water-glycerin mixtures by using the pulse-echo ultrasonic technique. A 2m long acrylic tube with inner diameter of 24 mm was used in the experiments. Initially, the tube was sealed at the ends and filled partially with the liquid mixtures to leave an air pocket of length L 0 at the top end. A Taylor bubble was formed by the inversion of the tube. The rising bubbles were detected by ultrasonic transducers located at the upper part of the tube. The velocity, the length and the pro le of the bubbles and the thickness of the liquid lm around them were obtained from the ultrasonic signals processing. The liquid lm thickness in the vertical tube was also determined by a graphic method that relates the bubble length L b with the initial length of the air pocket L 0 . It was observed that the bubble velocity decreased with increasing viscosity, while the lm thickness increased. It was shown that the liquid lm thickness determined by the graphic method fitted well the higher viscosities data, but overestimated the lower viscosities data. Additionally, the results indicated that some correlations developed to estimate the thickness of liquid films falling down inside/outside of tubes and down a plane surface could be applied to estimate the thickness of liquid films falling around Taylor bubbles in an Inverse Viscosity Number (N f ) range different to those considered in the literature. (author)

Phase Diagram of Binary Mixture E7:TM74A Liquid Crystals

Directory of Open Access Journals (Sweden)

Serafin Delica

1999-12-01

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

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

International Nuclear Information System (INIS)

Choi, K.

1979-01-01

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

Radiation degradation of waste waters. Reverse phase-high performance liquid chromatography and multicomponent UV-VIS analysis of gamma-irradiated aqueous solutions of nitrobenzene Pt.1

International Nuclear Information System (INIS)

Kuruc, J.; Sahoo, M.K.; Locaj, J.; Hutta, M.

1994-01-01

Saturated aqueous solutions of nitrobenzene (in water, 0.1M nitric acid and 0.1M potassium hydroxide) were irradiated with 60 Co γ-rays in deaerated condition. Radiolytic products were analyzed using reverse phase-high performance liquid chromatography (RP-HPLC) and multicomponent UV-VIS spectrometry. With the aid of RP-HPLC retention times of the radiolytic products were found to be identical with those of isomeric nitrophenols, aminophenols and dinitrophenols. According to the primary information obtained from RP-HPLC and literature, we have chosen ten standards and eleven wavelengths for multicomponent UV-VIS analysis (linear multiparametric regression analysis) and the concentrations of nitrobenzene, nitrophenols, aminophenols and dinitrophenols in water, HNO 3 and KOH solutions were calculated. G-values (molecules/100 eV) of the radiolytic products and decomposition of nitrobenzene in aqueous solutions G(-nitrobenzene) were calculated from the dependence of their concentrations with dose. Ph has relatively little influence on the decrease of concentration of nitrobenzene, but has strong influence on the product composition. (author) 7 refs.; 5 figs.; 5 tabs

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

Energy Technology Data Exchange (ETDEWEB)

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

1990-03-01

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

Ignition of alkane-rich FACE gasoline fuels and their surrogate mixtures

KAUST Repository

Sarathy, Mani

2015-01-01

Petroleum derived gasoline is the most used transportation fuel for light-duty vehicles. In order to better understand gasoline combustion, this study investigated the ignition propensity of two alkane-rich FACE (Fuels for Advanced Combustion Engines) gasoline test fuels and their corresponding PRF (primary reference fuel) blend in fundamental combustion experiments. Shock tube ignition delay times were measured in two separate facilities at pressures of 10, 20, and 40 bar, temperatures from 715 to 1500 K, and two equivalence ratios. Rapid compression machine ignition delay times were measured for fuel/air mixtures at pressures of 20 and 40 bar, temperatures from 632 to 745 K, and two equivalence ratios. Detailed hydrocarbon analysis was also performed on the FACE gasoline fuels, and the results were used to formulate multi-component gasoline surrogate mixtures. Detailed chemical kinetic modeling results are presented herein to provide insights into the relevance of utilizing PRF and multi-component surrogate mixtures to reproduce the ignition behavior of the alkane-rich FACE gasoline fuels. The two FACE gasoline fuels and their corresponding PRF mixture displayed similar ignition behavior at intermediate and high temperatures, but differences were observed at low temperatures. These trends were mimicked by corresponding surrogate mixture models, except for the amount of heat release in the first stage of a two-stage ignition events, when observed. © 2014 The Combustion Institute.

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

International Nuclear Information System (INIS)

Song, Dayong; Chen, Jing

2014-01-01

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

Vapor-liquid, liquid-liquid and vapor-liquid-liquid equilibrium of binary and multicomponent systems with MEG modeling with the CPA EoS and an EoS/G(E) model

DEFF Research Database (Denmark)

Folas, Georgios; Kontogeorgis, Georgios; Michelsen, Michael Locht

2006-01-01

The cubic-plus-association (CPA) EoS is applied to multicomponent multiphase equilibria of systems containing MEG as a hydrate inhibitor. It is shown that the model provides very satisfactory prediction of the phase behavior for the systems tested. A more conventional engineering model for handling...

Molar excess volumes of liquid hydrogen and neon mixtures from path integral simulation

International Nuclear Information System (INIS)

Challa, S.R.; Johnson, J.K.

1999-01-01

Volumetric properties of liquid mixtures of neon and hydrogen have been calculated using path integral hybrid Monte Carlo simulations. Realistic potentials have been used for the three interactions involved. Molar volumes and excess volumes of these mixtures have been evaluated for various compositions at 29 and 31.14 K, and 30 atm. Significant quantum effects are observed in molar volumes. Quantum simulations agree well with experimental molar volumes. Calculated excess volumes agree qualitatively with experimental values. However, contrary to the existing understanding that large positive deviations from ideal mixtures are caused due to quantum effects in Ne - H 2 mixtures, both classical as well as quantum simulations predict the large positive deviations from ideal mixtures. Further investigations using two other Ne - H 2 potentials of Lennard - Jones (LJ) type show that excess volumes are very sensitive to the cross-interaction potential. We conclude that the cross-interaction potential employed in our simulations is accurate for volumetric properties. This potential is more repulsive compared to the two LJ potentials tested, which have been obtained by two different combining rules. This repulsion and a comparatively lower potential well depth can explain the positive deviations from ideal mixing. copyright 1999 American Institute of Physics

Self-compacting concrete mixtures for road BUILDING

Directory of Open Access Journals (Sweden)

Tran Tuan My

2012-10-01

Therefore, effective concrete road pavements require self-compacting though non-segregating concrete mixtures to comply with the pre-set values of their properties, namely, bending and compressive strength, corrosion resistance, freeze resistance, etc. Acting in cooperation with Department of Technology of Binders and Concretes of MSUCE, NIIMosstroy developed and examined a self-compacting cast concrete mixture designated for durable monolithic road pavements. The composition in question was generated by adding a multi-component modifier into the mix. The modifier was composed of a hyperplasticiser, active (structureless fine and crystalline silica, and a concrete hardening control agent.

Fully integrated microfluidic measurement system for real-time determination of gas and liquid mixtures composition

NARCIS (Netherlands)

Lötters, Joost Conrad; Groenesteijn, Jarno; van der Wouden, E.J.; Sparreboom, Wouter; Lammerink, Theodorus S.J.; Wiegerink, Remco J.

2015-01-01

We have designed and realised a fully integrated microfluidic measurement system for real-time determination of both flow rate and composition of gas- and liquid mixtures. The system comprises relative permittivity sensors, pressure sensors, a Coriolis flow and density sensor, a thermal flow sensor

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

(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......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...... and three quaternary mixtures are considered. It is shown that overall excellent correlation for binary, mixtures and satisfactory prediction results for multicomponent systems are obtained. There are significant differences between the various modeling approaches and the best results are obtained when...

Mathematical modeling of planar and spherical vapor–liquid phase interfaces for multicomponent fluids

Directory of Open Access Journals (Sweden)

Celný David

2016-01-01

Full Text Available Development of methods for accurate modeling of phase interfaces is important for understanding various natural processes and for applications in technology such as power production and carbon dioxide separation and storage. In particular, prediction of the course of the non-equilibrium phase transition processes requires knowledge of the properties of the strongly curved phase interfaces of microscopic droplets. In our work, we focus on the spherical vapor–liquid phase interfaces for binary mixtures. We developed a robust computational method to determine the density and concentration profiles. The fundamentals of our approach lie in the Cahn-Hilliard gradient theory, allowing to transcribe the functional formulation into a system of ordinary Euler-Langrange equations. This system is then split and modified into a shape suitable for iterative computation. For this task, we combine the Newton-Raphson and the shooting methods providing a good convergence speed. For the thermodynamic roperties, the PC–SAFT equation of state is used. We determine the density and concentration profiles for spherical phase interfaces at various saturation factors for the binary mixture of CO2 and C9H20. The computed concentration profiles allow to the determine the work of formation and other characteristics of the microscopic droplets.

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

International Nuclear Information System (INIS)

Jaubert, Silke; Maurer, Gerd

2014-01-01

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

Online combination of reversed-phase/reversed-phase and porous graphitic carbon liquid chromatography for multicomponent separation of proteomics and glycoproteomics samples.

Science.gov (United States)

Lam, Maggie P Y; Lau, Edward; Siu, S O; Ng, Dominic C M; Kong, Ricky P W; Chiu, Philip C N; Yeung, William S B; Lo, Clive; Chu, Ivan K

2011-11-01

In this paper, we describe an online combination of reversed-phase/reversed-phase (RP-RP) and porous graphitic carbon (PGC) liquid chromatography (LC) for multicomponent analysis of proteomics and glycoproteomics samples. The online RP-RP portion of this system provides comprehensive 2-D peptide separation based on sequence hydrophobicity at pH 2 and 10. Hydrophilic components (e.g. glycans, glycopeptides) that are not retained by RP are automatically diverted downstream to a PGC column for further trapping and separation. Furthermore, the RP-RP/PGC system can provide simultaneous extension of the hydropathy range and peak capacity for analysis. Using an 11-protein mixture, we found that the system could efficiently separate native peptides and released N-glycans from a single sample. We evaluated the applicability of the system to the analysis of complex biological samples using 25 μg of the lysate of a human choriocarcinoma cell line (BeWo), confidently identifying a total of 1449 proteins from a single experiment and up to 1909 distinct proteins from technical triplicates. The PGC fraction increased the sequence coverage through the inclusion of additional hydrophilic sequences that accounted for up to 6.9% of the total identified peptides from the BeWo lysate, with apparent preference for the detection of hydrophilic motifs and proteins. In addition, RP-RP/PGC is applicable to the analysis of complex glycomics samples, as demonstrated by our analysis of a concanavalin A-extracted glycoproteome from human serum; in total, 134 potentially N-glycosylated serum proteins, 151 possible N-glycosylation sites, and more than 40 possible N-glycan structures recognized by concanavalin A were simultaneously detected. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Highly tilted liquid crystalline materials possessing a direct phase transition from antiferroelectric to isotropic phase

Energy Technology Data Exchange (ETDEWEB)

Milewska, K.; Drzewiński, W. [Institute of Chemistry, Military University of Technology, 00-908 Warsaw (Poland); Czerwiński, M., E-mail: mczerwinski@wat.edu.pl [Institute of Chemistry, Military University of Technology, 00-908 Warsaw (Poland); Dąbrowski, R. [Institute of Chemistry, Military University of Technology, 00-908 Warsaw (Poland); Piecek, W. [Institute of Applied Physics, Military University of Technology, 00-908 Warsaw (Poland)

2016-03-01

Pure compounds and multicomponent mixtures with a broad temperature range of high tilted liquid crystalline antiferroelectric phase and a direct phase transition from antiferroelectric to isotropic phase, were obtained. X-ray diffraction analysis confirms these kinds of materials form a high tilted anticlinic phase, with a fixed layer spacing and very weak dependency upon temperature, after the transition from the isotropic phase. Due to this, not only pure orthoconic antiferroelectric liquid crystals but also those with a moderate tilt should generate a good dark state. Furthermore, due to the increased potential for forming anticlinic forces, such materials could minimize a commonly observed asymmetry of a rise and fall switching times at a surface stabilized geometry. - Highlights: • The new class of liquid crystalline materials with the direct SmC{sub A}*. • Iso phase transition were obtained. • Materials possess the layer spacing fixed and very weak dependent upon temperature. • Smectic layers without shrinkage are observed. • A good dark state can be generate in SSAFLC.

Investigation of the ionization mechanism of polycyclic aromatic hydrocarbons using an ethanol/bromobenzene/chlorobenzene/anisole mixture as a dopant in liquid chromatography/atmospheric pressure photoionization mass spectrometry

KAUST Repository

Amad, Maan H.

2012-09-23

RATIONALE An ethanol-based multicomponent dopant consisting of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v/v/v) has been used as a dopant for atmospheric pressure photoionization (APPI) of polycyclic aromatic hydrocarbons (PAHs). In this study the mechanism of ionization of PAHs assisted by the ethanol-based multicomponent dopant is investigated. METHODS The reactant background cluster ions of the ethanol-based multicomponent dopant observed in the positive ion APPI were studied. These studies were performed to investigate the mechanism behind the generation of a molecular radical cation (M +•) for PAHs by APPI assisted by the ethanol-based multicomponent dopant. Full scan and MS/MS analyses were conducted using an LTQ Orbitrap mass spectrometer. The effect of acidification of the mobile phase on the dopant cluster ion formation was also investigated. RESULTS With the ethanol-based multicomponent dopant, a single type of molecular radical cation M +• was observed for the studied PAHs. The characteristic ion signal of the multicomponent dopant mixture consisted of mainly anisole photoions at m/z 108.05697 and its adduct ions at m/z 124.05188 and 164.07061. The anisole ion response at m/z 108.05697 was stable in the presence of acetonitrile, methanol, water and 0.1% formic acid mobile phase composition. CONCLUSIONS The abundance formation of anisole photoions shows the universality of this multicomponent dopant in ionizing compounds with ionization energy ranging from 7.1-8.2 eV. Since the ionization energy of anisole is 8.2 eV and is lower than those of chlorobenzene (9.07 eV) and bromobenzene (9.0 eV), the mechanism of formation of anisole photoions even with its very minute amounts was not only governed by its photoionization by the krypton lamp photon energy (10.0 eV and 10.6 eV), but also by charge transfer from bromobenzene and chlorobenzene radical cations. PAH molecules were mainly ionized by charge transfer reaction from

Investigation of the ionization mechanism of polycyclic aromatic hydrocarbons using an ethanol/bromobenzene/chlorobenzene/anisole mixture as a dopant in liquid chromatography/atmospheric pressure photoionization mass spectrometry

KAUST Repository

Amad, Maan H.; Sioud, Salim

2012-01-01

RATIONALE An ethanol-based multicomponent dopant consisting of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v/v/v) has been used as a dopant for atmospheric pressure photoionization (APPI) of polycyclic aromatic hydrocarbons (PAHs). In this study the mechanism of ionization of PAHs assisted by the ethanol-based multicomponent dopant is investigated. METHODS The reactant background cluster ions of the ethanol-based multicomponent dopant observed in the positive ion APPI were studied. These studies were performed to investigate the mechanism behind the generation of a molecular radical cation (M +•) for PAHs by APPI assisted by the ethanol-based multicomponent dopant. Full scan and MS/MS analyses were conducted using an LTQ Orbitrap mass spectrometer. The effect of acidification of the mobile phase on the dopant cluster ion formation was also investigated. RESULTS With the ethanol-based multicomponent dopant, a single type of molecular radical cation M +• was observed for the studied PAHs. The characteristic ion signal of the multicomponent dopant mixture consisted of mainly anisole photoions at m/z 108.05697 and its adduct ions at m/z 124.05188 and 164.07061. The anisole ion response at m/z 108.05697 was stable in the presence of acetonitrile, methanol, water and 0.1% formic acid mobile phase composition. CONCLUSIONS The abundance formation of anisole photoions shows the universality of this multicomponent dopant in ionizing compounds with ionization energy ranging from 7.1-8.2 eV. Since the ionization energy of anisole is 8.2 eV and is lower than those of chlorobenzene (9.07 eV) and bromobenzene (9.0 eV), the mechanism of formation of anisole photoions even with its very minute amounts was not only governed by its photoionization by the krypton lamp photon energy (10.0 eV and 10.6 eV), but also by charge transfer from bromobenzene and chlorobenzene radical cations. PAH molecules were mainly ionized by charge transfer reaction from

Multi-component determination and chemometric analysis of Paris polyphylla by ultra high performance liquid chromatography with photodiode array detection.

Science.gov (United States)

Chen, Pei; Jin, Hong-Yu; Sun, Lei; Ma, Shuang-Cheng

2016-09-01

Multi-source analysis of traditional Chinese medicine is key to ensuring its safety and efficacy. Compared with traditional experimental differentiation, chemometric analysis is a simpler strategy to identify traditional Chinese medicines. Multi-component analysis plays an increasingly vital role in the quality control of traditional Chinese medicines. A novel strategy, based on chemometric analysis and quantitative analysis of multiple components, was proposed to easily and effectively control the quality of traditional Chinese medicines such as Chonglou. Ultra high performance liquid chromatography was more convenient and efficient. Five species of Chonglou were distinguished by chemometric analysis and nine saponins, including Chonglou saponins I, II, V, VI, VII, D, and H, as well as dioscin and gracillin, were determined in 18 min. The method is feasible and credible, and enables to improve quality control of traditional Chinese medicines and natural products. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Liquid viscosity of low-GWP refrigerant mixtures (R32 + R1234yf) and (R125 + R1234yf)

International Nuclear Information System (INIS)

Dang, Yagu; Kamiaka, Takumi; Dang, Chaobin; Hihara, Eiji

2015-01-01

Highlights: • We measured liquid viscosity of low GWP refrigerant R1234yf binary mixtures. • Viscosity of R1234yf mixtures were correlated with the roughness hard-sphere method. • Viscosity of R1234yf mixtures were correlated with the Grunberg and Nissan method. - Abstract: In this work, the viscosity of R1234yf, (R32 + R1234yf), and (R125 + R1234yf) in one-phase liquid was measured. The combined expanded uncertainty of viscosity measurement apparatus of confidence of 0.95 (k = 2) is about 2.0%. The measurements of mixtures containing (30.0, 50.0, and 70.0) wt% R32 or R125 were carried out between T = (283.0 and 323.0) K (at intervals of T = 5 K) and P = (1.58 and 2.74) MPa, with a moving piston viscometer (VISCOpro 1600, accuracy ±1.0%) and a Coriolis flowmeter (Ultramass MKII, accuracy ±0.001 g/ml). The measured data were correlated with a hard-sphere (RSH) method and the Grunberg and Nissan method. The average absolute deviations are (2.2 and 3.3)% for the (R32 + R1234yf) and (R125 + R1234yf) mixtures by RSH method, (2.8 and 1.3)% for the (R32 + R1234yf) and (R125 + R1234yf) mixtures by Grunberg and Nissan method, while (3.5 and 2.4)% for the (R32 + R1234yf) and (R125 + R1234yf) mixtures by RefProp V9.1, respectively

Ferroelectric BaTiO3 and LiNbO3 Nanoparticles Dispersed in Ferroelectric Liquid Crystal Mixtures: Electrooptic and Dielectric (Postprint)

Science.gov (United States)

2016-10-14

strength for non- doped LF4 and LiNbO3/LF4 nanocolloids at temperature 30C. 146 R. K . SHUKLA ET AL. 6 Distribution A. Approved for public release (PA...AFRL-RX-WP-JA-2017-0210 FERROELECTRIC BaTiO3 AND LiNbO3 NANOPARTICLES DISPERSED IN FERROELECTRIC LIQUID CRYSTAL MIXTURES: ELECTROOPTIC...COMMAND UNITED STATES AIR FORCE Ferroelectric BaTiO3 and LiNbO3 nanoparticles dispersed in ferroelectric liquid crystal mixtures: Electrooptic and

Robust optimization of psychotropic drug mixture separation in hydrophilic interaction liquid chromatography.

Science.gov (United States)

Rakić, Tijana; Jovanović, Marko; Dumić, Aleksandra; Pekić, Marina; Ribić, Sanja; Stojanović, Biljana Jancić

2013-01-01

This paper presents multiobjective optimization of complex mixtures separation in hydrophilic interaction liquid chromatography (HILIC). The selected model mixture consisted of five psychotropic drugs: clozapine, thioridazine, sulpiride, pheniramine and lamotrigine. Three factors related to the mobile phase composition (acetonitrile content, pH of the water phase and concentration of ammonium acetate) were optimized in order to achieve the following goals: maximal separation quality, minimal total analysis duration and robustness of an optimum. The consideration of robustness in early phases of the method development provides reliable methods with low risk for failure in validation phase. The simultaneous optimization of all goals was achieved by multiple threshold approach combined with grid point search. The identified optimal separation conditions (acetonitrile content 83%, pH of the water phase 3.5 and ammonium acetate content in water phase 14 mM) were experimentally verified.

Verifying reciprocal relations for experimental diffusion coefficients in multicomponent mixtures

DEFF Research Database (Denmark)

Medvedev, Oleg; Shapiro, Alexander

2003-01-01

The goal of the present study is to verify the agreement of the available data on diffusion in ternary mixtures with the theoretical requirement of linear non-equilibrium thermodynamics consisting in symmetry of the matrix of the phenomenological coefficients. A common set of measured diffusion...... coefficients for a three-component mixture consists of four Fickian diffusion coefficients, each being reported separately. However, the Onsager theory predicts the existence of only three independent coefficients, as one of them disappears due to the symmetry requirement. Re-calculation of the Fickian...... extended sets of experimental data and reliable thermodynamic models were available. The sensitivity of the symmetry property to different thermodynamic parameters of the models was also checked. (C) 2003 Elsevier Science B.V. All rights reserved....

Vapour pressures and osmotic coefficients of binary mixtures containing alcohol and pyrrolidinium-based ionic liquids

International Nuclear Information System (INIS)

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

2013-01-01

Highlights: • Osmotic coefficients of alcohols with pyrrolidinium ILs are determined. • Experimental data were correlated with extended Pitzer model of Archer and MNRTL. • Mean molal activity coefficients and excess Gibbs free energies were calculated. • The results have been interpreted in terms of interactions. -- Abstract: The osmotic and activity coefficients and vapour pressures of mixtures containing primary (1-propanol, 1-butanol and 1-pentanol) and secondary (2-propanol and 2-butanol) alcohols with pyrrolidinium-based ionic liquids (1-butyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide, C 4 MpyrNTf 2 , and 1-butyl-1-methyl pyrrolidinium trifluoromethanesulfonate, C 4 MpyrTFO) have been experimentally determined at T = 323.15 K. For the experimental measurements, the vapour pressure osmometry technique has been used. The results on the influence of the structure of the alcohol and of the anion of the ionic liquid on the determined properties have been discussed and compared with literature data. For the correlation of the osmotic coefficients obtained, the Extended Pitzer model of Archer and the Modified Non-Random Two Liquids model were applied. The mean molal activity coefficients and the excess Gibbs energy for the studied mixtures were calculated from the parameters obtained in the correlation

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

International Nuclear Information System (INIS)

Heintz, Andreas

2005-01-01

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

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

International Nuclear Information System (INIS)

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

2017-01-01

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

PVTxy properties of CO2 mixtures relevant for CO2 capture, transport and storage: Review of available experimental data and theoretical models

International Nuclear Information System (INIS)

Li, Hailong; Jakobsen, Jana P.; Wilhelmsen, Oivind; Yan, Jinyue

2011-01-01

Highlights: → Accurate knowledge about the thermodynamic properties of CO 2 is essential in the design and operation of CCS systems. → Experimental data about the phase equilibrium and density of CO 2 -mixtures have been reviewed. → Equations of state have been reviewed too regarding CO 2 -mixtures. None has shown any clear advantage in CCS applications. → Identified knowledge gaps suggest to conducting more experiments and developing novel models. -- Abstract: The knowledge about pressure-volume-temperature-composition (PVTxy) properties plays an important role in the design and operation of many processes involved in CO 2 capture and storage (CCS) systems. A literature survey was conducted on both the available experimental data and the theoretical models associated with the thermodynamic properties of CO 2 mixtures within the operation window of CCS. Some gaps were identified between available experimental data and requirements of the system design and operation. The major concerns are: for the vapour-liquid equilibrium, there are no data about CO 2 /COS and few data about the CO 2 /N 2 O 4 mixture. For the volume property, there are no published experimental data for CO 2 /O 2 , CO 2 /CO, CO 2 /N 2 O 4 , CO 2 /COS and CO 2 /NH 3 and the liquid volume of CO 2 /H 2 . The experimental data available for multi-component CO 2 mixtures are also scarce. Many equations of state are available for thermodynamic calculations of CO 2 mixtures. The cubic equations of state have the simplest structure and are capable of giving reasonable results for the PVTxy properties. More complex equations of state such as Lee-Kesler, SAFT and GERG typically give better results for the volume property, but not necessarily for the vapour-liquid equilibrium. None of the equations of state evaluated in the literature show any clear advantage in CCS applications for the calculation of all PVTxy properties. A reference equation of state for CCS should, thus, be a future goal.

Characterization of liquid products from the co-cracking of ternary and quaternary mixture of petroleum vacuum residue, polypropylene, Samla coal and Calotropis Procera

Energy Technology Data Exchange (ETDEWEB)

M. Ahmaruzzaman; D.K. Sharma [Indian Institute of Technology Delhi, New Delhi (India). Centre for Energy Studies

2008-08-15

The co-cracking of the petroleum vacuum residue (XVR) with polypropylene (PP), Samla coal (SC) and Calotropis procera (CL) has been carried out in a batch reactor under isothermal conditions at atmospheric pressure. The liquids obtained by co-cracking have been characterized by Fourier transform infrared spectroscopy, high performance liquid chromatography, {sup 1}H nuclear magnetic resonance (NMR), {sup 13}C NMR, gel permeation chromatography (GPC), and inductively coupled argon plasma analyses. It was found that the liquid products obtained from the co-cracking of ternary and quaternary mixtures of the petroleum vacuum residue with polypropylene, coal and C. procera contained less than 1 ppm of Ni and V. The HPLC analyses indicates that the liquids obtained from the cracking of ternary mixture of XVR+PP+CL were mainly aliphatic in nature (saturates content 87.4%). NMR analyses showed that the aromatic carbon contents decreased (15.0%) in the liquid products derived from the co-cracking of quaternary mixtures of XVR+PP+SC+CL compared to their theoretical averages (taking the averages of aromatic carbon contents of the liquids from XVR, PP, SC and CL individually). The overall results indicated that there exists a definite interaction of reactive species when XVR, PP, SC and CL were co-cracked together. 27 refs., 5 tabs.

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Generation of thermodynamic data for organic liquid mixtures from molecular simulations

DEFF Research Database (Denmark)

Christensen, Steen; Peters, Günther H.j.; Hansen, Flemming Yssing

2007-01-01

Fluctuation solution theory (FST) is employed to analyze results of molecular dynamics (MD) simulations of liquid mixtures. The objective is to generate parameters for macroscopic thermodynamic property models. Two benchmark systems, benzene-methyl acetate at 303.15 K and benzene-ethanol at 298.......15 K, are used. MD simulations are performed in the isobaric-isothermal ensemble (NPT) at the respective temperatures and at a pressure of 1 atm. We use the CHARMM27 force field at different mixing ratios. We sample positions to determine the binary (between the centers-of-mass of molecules of a pair...

Modeling and parametric analysis of hollow fiber membrane system for carbon capture from multicomponent flue gas

KAUST Repository

Khalilpour, Rajab

2011-08-12

The modeling and optimal design/operation of gas membranes for postcombustion carbon capture (PCC) is presented. A systematic methodology is presented for analysis of membrane systems considering multicomponent flue gas with CO 2 as target component. Simplifying assumptions is avoided by namely multicomponent flue gas represented by CO 2/N 2 binary mixture or considering the co/countercurrent flow pattern of hollow-fiber membrane system as mixed flow. Optimal regions of flue gas pressures and membrane area were found within which a technoeconomical process system design could be carried out. High selectivity was found to not necessarily have notable impact on PCC membrane performance, rather, a medium selectivity combined with medium or high permeance could be more advantageous. © 2011 American Institute of Chemical Engineers (AIChE).

On the Crystallization of Compacted and Chunky Graphite from Liquid Multicomponent Iron-Carbon-Silicon-Based Melts

Science.gov (United States)

Stefanescu, D. M.; Huff, R.; Alonso, G.; Larrañaga, P.; De la Fuente, E.; Suarez, R.

2016-08-01

Extensive SEM work was carried out on deep-etched specimens to reveal the evolution of compacted and chunky graphite in magnesium-modified multicomponent Fe-C-Si alloys during early solidification and at room temperature. The findings of this research were then integrated in the current body of knowledge to produce an understanding of the crystallization of compacted and chunky graphite. It was confirmed that growth from the liquid for both compacted and chunky graphite occurs radially from a nucleus, as foliated crystals and dendrites. The basic building blocks of the graphite aggregates are hexagonal faceted graphite platelets with nanometer height and micrometer width. Thickening of the platelets occurs through growth of additional graphene layers nucleated at the ledges of the graphite prism. Additional thickening resulting in complete joining of the platelets may occur from the recrystallization of the amorphous carbon that has diffused from the liquid through the austenite, once the graphite aggregate is enveloped in austenite. With increasing magnesium levels, the foliated graphite platelets progressively aggregate along the c-axis forming clusters. The clusters that have random orientation, eventually produce blocky graphite, as the spaces between the parallel platelets disappear. This is typical for compacted graphite irons and tadpole graphite. The chunky graphite aggregates investigated are conical sectors of graphite platelets stacked along the c-axis. The foliated dendrites that originally develop radially from a common nucleus may aggregate along the c-axis forming blocky graphite that sometimes exhibits helical growth. The large number of defects (cavities) observed in all graphite aggregates supports the mechanism of graphite growth as foliated crystals and dendrites.

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

Science.gov (United States)

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

2013-09-14

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

Detection of a new 'nematic-like' phase in liquid crystal-amphiphile mixture by differential scanning calorimetry

Energy Technology Data Exchange (ETDEWEB)

Dan, Kaustabh, E-mail: kaustabhdan@gmail.com; Roy, Madhusudan, E-mail: kaustabhdan@gmail.com; Datta, Alokmay, E-mail: kaustabhdan@gmail.com [Surface Physics and Materials Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar Block, Sector 1, Kolkata-700064 (India)

2014-04-24

Differential Scanning Calorimetry (DSC) studies on phase transitions of the pure liquid crystalline material N-4-methoxybenzylidene-4-butylaniline (MBBA) and mixtures of MBBA and the amphiphile Stearic Acid (StA) show significant changes in the behavior of mixture from pure MBBA, as regards the nematic-isotropic (N-I) transition temperature (T{sub c}) and other thermodynamic parameters like enthalpy, specific heat and activation energy with concentration of StA. In particular, the convexity of the Arrhenius plot in pure MBBA vanishes with StA concentration pointing to the formation of a new, perhaps 'nematic-like', phase in the mixtures.

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

International Nuclear Information System (INIS)

Liu, Baoyou; Liu, Yaru

2016-01-01

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

Industrial aspects of gas-liquid two-phase flow

International Nuclear Information System (INIS)

Hewitt, G.F.

1977-01-01

The lecture begins by reviewing the various types of plant in which two phase flow occurs. Specifically, boiling plant, condensing plant and pipelines are reviewed, and the various two phase flow problems occurring in them are described. Of course, many other kinds of chemical engineering plant involve two phase flow, but are somewhat outside the scope of this lecture. This would include distillation columns, vapor-liquid separators, absorption towers etc. Other areas of industrial two phase flow which have been omitted for space reasons from this lecture are those concerned with gas/solids, liquid/solid and liquid/liquid flows. There then follows a description of some of the two phase flow processes which are relevant in industrial equipment and where special problems occur. The topics chosen are as follows: (1) pressure drop; (2) horizontal tubes - separation effects non-uniformites in heat transfer coefficient, effect of bends on dryout; (3) multicomponent mixtures - effects in pool boiling, mass transfer effects in condensation and Marangoni effects; (4) flow distribution - manifold problems in single phase flow, separation effects at a single T-junction in two phase flow and distribution in manifolds in two phase flow; (5) instability - oscillatory instability, special forms of instability in cryogenic systems; (6) nucleate boiling - effect of variability of surface, unresolved problems in forced convective nucleate boiling; and (7) shell side flows - flow patterns, cross flow boiling, condensation in cross flow

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Vapor-Liquid Equilibrium in the Mixture 1,1-Difluoroethane C2H4F2 + C4H8 2-Methylpropene (EVLM1131, LB5730_E)

Science.gov (United States)

Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Vapor-Liquid Equilibrium in the Mixture 1,1-Difluoroethane C2H4F2 + C4H8 2-Methylpropene (EVLM1131, LB5730_E)' providing data from direct measurement of pressure and mole fraction in vapor phase at variable mole fraction in liquid phase and constant temperature.

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

International Nuclear Information System (INIS)

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

2008-01-01

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

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

NARCIS (Netherlands)

Suttorp, L.G.; Ebeling, W.

1992-01-01

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

Rogue waves in the multicomponent Mel'nikov system and multicomponent Schrödinger-Boussinesq system

Science.gov (United States)

Sun, Baonan; Lian, Zhan

2018-02-01

By virtue of the bilinear method and the KP hierarchy reduction technique, exact explicit rational solutions of the multicomponent Mel'nikov equation and the multicomponent Schrödinger-Boussinesq equation are constructed, which contain multicomponent short waves and single-component long wave. For the multicomponent Mel'nikov equation, the fundamental rational solutions possess two different behaviours: lump and rogue wave. It is shown that the fundamental (simplest) rogue waves are line localised waves which arise from the constant background with a line profile and then disappear into the constant background again. The fundamental line rogue waves can be classified into three: bright, intermediate and dark line rogue waves. Two subclasses of non-fundamental rogue waves, i.e., multirogue waves and higher-order rogue waves are discussed. The multirogue waves describe interaction of several fundamental line rogue waves, in which interesting wave patterns appear in the intermediate time. Higher-order rogue waves exhibit dynamic behaviours that the wave structures start from lump and then retreat back to it. Moreover, by taking the parameter constraints further, general higher-order rogue wave solutions for the multicomponent Schrödinger-Boussinesq system are generated.

Multicomponent Syntheses of Macrocycles

Science.gov (United States)

Masson, Géraldine; Neuville, Luc; Bughin, Carine; Fayol, Aude; Zhu, Jieping

How to access efficiently the macrocyclic structure remained to be a challenging synthetic topic. Although many elegant approaches/reactions have been developed, construction of diverse collection of macrocycles is still elusive. This chapter summarized the recently emerged research area dealing with multicomponent synthesis of macrocycles, with particular emphasis on the approach named "multiple multicomponent reaction using two bifunctional building blocks".

Phase formation in multicomponent monotectic aluminium alloys

Energy Technology Data Exchange (ETDEWEB)

Mirkovic, Djordje; Groebner, Joachim; Schmid-Fetzer, Rainer [Institute of Metallurgy, Clausthal University of Technology (Germany)

2008-07-01

Alloys with a miscibility gap in the liquid state are potential materials for advanced bearings in automotive and other applications. While binary alloys, such as Al-Pb or Al-Bi, are well known, the information available for ternary monotectic Al-alloys is scarce. However, the phase formation in multicomponent alloys is not only more challenging from a scientific aspect, it is also a prerequisite for a focused development of advanced alloys. This motivated our detailed study of monotectic Al-Bi-Cu-Sn alloys including both experimental and computational thermodynamic methods. Based on the initially established systematic classification of monotectic ternary Al-alloys, the first promising monotectic reaction was observed in the ternary Al-Bi-Zn system. Further ternary systems Al-Cu-Sn, Al-Bi-Sn, Al-Bi-Cu and Bi-Cu-Sn were investigated as basis for quaternary Al-Bi-Cu-Sn alloys. Experimental investigations of phase equilibria, enthalpies and solidification microstructures were combined with thermodynamic modeling. The results demonstrate that the developed precise thermodynamic description is vital to reveal the distinct multicomponent monotectic features of pertinent phase diagrams. The solidification paths of ternary monotectic alloy systems, Al-Bi-Zn, Al-Sn-Cu and Al-Bi-Cu, were also studied using thermodynamic calculations, revealing specific details of phase formation during solidification of selected alloys.

Kinetic energy of He atoms in liquid 4He-3He mixtures

International Nuclear Information System (INIS)

Senesi, R.; Andreani, C.; Fielding, A.L.; Mayers, J.; Stirling, W.G.

2003-01-01

Deep inelastic neutron scattering measurements on liquid 3 He- 4 He mixtures in the normal phase have been performed on the VESUVIO spectrometer at the ISIS pulsed neutron source at exchanged wave vectors of about q≅120.0 A -1 . The neutron Compton profiles J(y) of the mixtures were measured along the T=1.96 K isotherm for 3 He concentrations, x, ranging from 0.1 to 1.0 at saturated vapor pressures. Values of kinetic energies of 3 He and 4 He atoms as a function of x, (x), were extracted from the second moment of J(y). The present determinations of (x) confirm previous experimental findings for both isotopes and, in the case of 3 He, a substantial disagreement with theory is found. In particular (x) for the 3 He atoms is found to be independent of concentration yielding a value 3 (x=0.1)≅12 K, much lower than the value suggested by the most recent theoretical estimates of approximately 19 K

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

International Nuclear Information System (INIS)

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

2011-01-01

Research highlights: → This paper reports the density and speed of sound data of binary mixtures {2-hydroxy ethylammonium acetate + (water, or methanol, or ethanol)} measured between the temperatures (298.15 and 313.15) K at atmospheric pressure. → The aggregation, dynamic behavior, and hydrogen-bond network were studied using thermo-acoustic, X-ray, and NMR techniques. → The Peng-Robinson equation of state, coupled with the Wong-Sandler mixing rule using the COSMO-SAC model predicted the density of the solutions with relative mean deviations below than 3.0%. - Abstract: In this work, density and speed of sound data of binary mixtures of an ionic liquid consisting of {2-hydroxy ethylammonium acetate (2-HEAA) + (water, methanol, or ethanol)} have been measured throughout the entire concentration range, from the temperature of (288.15 to 323.15) K at atmospheric pressure. The excess molar volumes, variations of the isentropic compressibility, the apparent molar volume, isentropic apparent molar compressibility, and thermal expansion coefficient were calculated from the experimental data. The excess molar volumes were negative throughout the whole composition range. Compressibility data in combination with low angle X-ray scattering and NMR measurements proved that the presence of micelles formed due to ion pair interaction above a critical concentration of the ionic liquid in the mixtures. The Peng-Robinson equation of state coupled with the Wong-Sandler mixing rule and COSMO-SAC model was used to predict densities and the calculated deviations were lower than 3%, for binary mixtures in all composition range.

Influence of trace elements mixture on bacterial diversity and fermentation characteristics of liquid diet fermented with probiotics under air-tight condition.

Directory of Open Access Journals (Sweden)

Yuyong He

Full Text Available Cu2+, Zn2+, Fe2+ and I- are often supplemented to the diet of suckling and early weaning piglets, but little information is available regarding the effects of different Cu2+, Zn2+, Fe2+ and I- mixtures on bacteria growth, diversity and fermentation characteristics of fermented liquid diet for piglets. Pyrosequencing was performed to investigate the effect of Cu2+, Zn2+, Fe2+ and I- mixtures on the diversity, growth and fermentation characteristics of bacteria in the liquid diet fermented with Bacillus subtilis and Enterococcus faecalis under air-tight condition. Results showed that the mixtures of Cu2+, Zn2+, Fe2+ and I- at different concentrations promoted Bacillus growth, increased bacterial diversity and lactic acid production and lowered pH to about 5. The importance of Cu2+, Zn2+, Fe2+ and I- is different for Bacillus growth with the order Zn2+> Fe2+>Cu2+> I- in a 21-d fermentation and Cu2+>I->Fe2+>Zn2+ in a 42-d fermentation. Cu2+, Zn2+, Fe2+ and I- is recommended at a level of 150, 60, 150 and 0.6 mg/kg respectively for the production of fermented liquid diet with Bacillus subtilis. The findings improve our understanding of the influence of trace elements on liquid diet fermentation with probiotics and support the proper use of trace elements in the production of fermented liquid diet for piglets.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-09-28

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Experimental determination of critical data of multi-component mixtures containing potential gasoline additives 2-butanol by a flow-type apparatus

International Nuclear Information System (INIS)

He, Maogang; Xin, Nan; Wang, Chengjie; Liu, Yang; Zhang, Ying; Liu, Xiangyang

2016-01-01

Graphical abstract: Experimental critical pressures of 2-butanol + hexane + heptane system. - Highlights: • Critical properties of six binary systems and two ternary systems were measured. • Six binary systems containing 2-butanol show non-ideal behavior in their T c –x 1 curves. • Non-ideal behavior of mixtures with 2-butanol relies on azeotropy. • Experimental data for binary systems were fitted well with Redlich–Kister equation. • Critical surfaces of ternary systems were plotted using the Cibulka’s expressions. - Abstract: In this work, we used a flow method for measurement of critical properties of six binary mixtures (2-butanol + cyclohexane, 2-butanol + hexane, 2-butanol + heptane, 2-butanol + octane, 2-butanol + nonane and 2-butanol + decane) and two ternary mixtures (2-butanol + hexane + heptane and 2-butanol + octane + decane). The critical properties were determined by observing the disappearance and reappearance of the gas–liquid phase meniscus in a quartz glass tube. The standard uncertainties of temperatures and pressures for both binary and ternary mixtures were estimated to be less than 0.2 K and 5.2 kPa, respectively. These critical data provide the boundaries of the two-phase regions of the related mixture systems. Six binary systems show non-ideal behaviors in the loci of critical temperatures. We used the Redlich–Kister equations to correlate the critical temperatures and pressures of these systems and listed the binary interaction parameters. The maximum average absolute deviation (AAD) of each binary system between experimental data and calculated results from Redlich–Kister equations is 0.038% for critical temperatures, and 0.244% for critical pressures. Moreover, the two ternary systems were newly reported and correlated by Cibulka’s and Singh’s expressions. The maximum AAD of critical temperatures and critical pressures are 0.103% and 0.433%, respectively.

Phase Equilibrium Calculations for Multi-Component Polar Fluid Mixtures with tPC-PSAFT

DEFF Research Database (Denmark)

Karakatsani, Eirini; Economou, Ioannis

2007-01-01

The truncated Perturbed-Chain Polar Statistical Associating Fluid Theory (tPC-PSAFT) is applied to a number of different mixtures, including binary, ternary and quaternary mixtures of components that differ substantially in terms of intermolecular interactions and molecular size. In contrast to m...

Solidification paths of multicomponent monotectic aluminum alloys

Energy Technology Data Exchange (ETDEWEB)

Mirkovic, Djordje; Groebner, Joachim [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Street 42, D-38678 Clausthal-Zellerfeld (Germany); Schmid-Fetzer, Rainer [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Street 42, D-38678 Clausthal-Zellerfeld (Germany)], E-mail: schmid-fetzer@tu-clausthal.de

2008-10-15

Solidification paths of three ternary monotectic alloy systems, Al-Bi-Zn, Al-Sn-Cu and Al-Bi-Cu, are studied using thermodynamic calculations, both for the pertinent phase diagrams and also for specific details concerning the solidification of selected alloy compositions. The coupled composition variation in two different liquids is quantitatively given. Various ternary monotectic four-phase reactions are encountered during solidification, as opposed to the simple binary monotectic, L' {yields} L'' + solid. These intricacies are reflected in the solidification microstructures, as demonstrated for these three aluminum alloy systems, selected in view of their distinctive features. This examination of solidification paths and microstructure formation may be relevant for advanced solidification processing of multicomponent monotectic alloys.

Shear viscosity of liquid mixtures: Mass dependence

International Nuclear Information System (INIS)

Kaushal, Rohan; Tankeshwar, K.

2002-06-01

Expressions for zeroth, second, and fourth sum rules of transverse stress autocorrelation function of two component fluid have been derived. These sum rules and Mori's memory function formalism have been used to study shear viscosity of Ar-Kr and isotopic mixtures. It has been found that theoretical result is in good agreement with the computer simulation result for the Ar-Kr mixture. The mass dependence of shear viscosity for different mole fraction shows that deviation from ideal linear model comes even from mass difference in two species of fluid mixture. At higher mass ratio shear viscosity of mixture is not explained by any of the emperical model. (author)

Shear viscosity of liquid mixtures Mass dependence

CERN Document Server

Kaushal, R

2002-01-01

Expressions for zeroth, second, and fourth sum rules of transverse stress autocorrelation function of two component fluid have been derived. These sum rules and Mori's memory function formalism have been used to study shear viscosity of Ar-Kr and isotopic mixtures. It has been found that theoretical result is in good agreement with the computer simulation result for the Ar-Kr mixture. The mass dependence of shear viscosity for different mole fraction shows that deviation from ideal linear model comes even from mass difference in two species of fluid mixture. At higher mass ratio shear viscosity of mixture is not explained by any of the emperical model.

On the nonequilibrium segregation state of a two-phase mixture in a porous column

DEFF Research Database (Denmark)

Shapiro, Alexander; Stenby, Erling Halfdan

1996-01-01

The problem of segregation of a two-phase multicomponent mixture under the action of thermal gradient, gravity and capillary forces is studied with respect to component distribution in a thick oil-gas-condensate reservoir. Governing equations are derived on the basis of nonequilibrium...

Experimental evidence for excess entropy discontinuities in glass-forming solutions.

Science.gov (United States)

Lienhard, Daniel M; Zobrist, Bernhard; Zuend, Andreas; Krieger, Ulrich K; Peter, Thomas

2012-02-21

Glass transition temperatures T(g) are investigated in aqueous binary and multi-component solutions consisting of citric acid, calcium nitrate (Ca(NO(3))(2)), malonic acid, raffinose, and ammonium bisulfate (NH(4)HSO(4)) using a differential scanning calorimeter. Based on measured glass transition temperatures of binary aqueous mixtures and fitted binary coefficients, the T(g) of multi-component systems can be predicted using mixing rules. However, the experimentally observed T(g) in multi-component solutions show considerable deviations from two theoretical approaches considered. The deviations from these predictions are explained in terms of the molar excess mixing entropy difference between the supercooled liquid and glassy state at T(g). The multi-component mixtures involve contributions to these excess mixing entropies that the mixing rules do not take into account. © 2012 American Institute of Physics

Problems of hydrogen - water vapor - inert gas mixture use in heavy liquid metal coolant technology

International Nuclear Information System (INIS)

Ul'yanov, V.V.; Martynov, P.N.; Gulevskij, V.A.; Teplyakov, Yu.A.; Fomin, A.S.

2014-01-01

The reasons of slag deposit formation in circulation circuits with heavy liquid metal coolants, which can cause reactor core blockage, are considered. To prevent formation of deposits hydrogen purification of coolant and surfaces of circulation circuit is used. It consists in introduction of gaseous mixtures hydrogen - water vapor - rare gas (argon or helium) directly into coolant flow. The principle scheme of hydrogen purification and the processes occurring during it are under consideration. Measures which make it completely impossible to overlap of the flow cross section of reactor core, steam generators, pumps and other equipment by lead oxides in reactor facilities with heavy liquid metal coolants are listed [ru

(Liquid + liquid) equilibria of perfluorocarbons with fluorinated ionic liquids

International Nuclear Information System (INIS)

Martinho, S.; Araújo, J.M.M.; Rebelo, L.P.N.; Pereiro, A.B.; Marrucho, I.M.

2013-01-01

Highlights: • (Liquid + liquid) equilibria perfluorocarbons and fluorinated ionic liquids. • Non-Random Two Liquid model was successfully applied. • Thermodynamic functions that describe the solvation process were calculated. -- Abstract: In order to evaluate the feasibility of partially replace perfluorocarbons (PFCs) with fluorinated ionic liquids (FILs) in PFCs-in-water emulsions, usually used for biomedical purposes, herein the (liquid + liquid) phase equilibria of FILs containing fluorinated chains longer than four carbons with PFCs were carried out in a wide range of temperatures. With this goal in mind, two PFCs (perfluorooctane and perfluorodecalin) were selected and the (liquid + liquid) equilibria of the binary mixtures of these PFCs and FILs were studied at atmospheric pressure in a temperature range from T (293.15 to 343.15) K. For these studies, FILs containing ammonium, pyridinium and imidazolium cations and different anions with fluorocarbon alkyl chains between 4 and 8 were included. Additionally, Non-Random Two Liquid (NRTL) thermodynamic model was successfully applied to correlate the behaviour of the PFCs + FILs binary mixtures. Moreover, thermodynamic functions that describe the solvation process were calculated from the experimental data

On thermal conductivity of gas mixtures containing hydrogen

Science.gov (United States)

Zhukov, Victor P.; Pätz, Markus

2017-06-01

A brief review of formulas used for the thermal conductivity of gas mixtures in CFD simulations of rocket combustion chambers is carried out in the present work. In most cases, the transport properties of mixtures are calculated from the properties of individual components using special mixing rules. The analysis of different mixing rules starts from basic equations and ends by very complex semi-empirical expressions. The formulas for the thermal conductivity are taken for the analysis from the works on modelling of rocket combustion chambers. \\hbox {H}_2{-}\\hbox {O}_2 mixtures are chosen for the evaluation of the accuracy of the considered mixing rules. The analysis shows that two of them, of Mathur et al. (Mol Phys 12(6):569-579, 1967), and of Mason and Saxena (Phys Fluids 1(5):361-369, 1958), have better agreement with the experimental data than other equations for the thermal conductivity of multicomponent gas mixtures.

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Automated high performance liquid chromatography and liquid scintillation counting determination of pesticide mixture octanol/water partition rates

International Nuclear Information System (INIS)

Moody, R.P.; Carroll, J.M.; Kresta, A.M.

1987-01-01

Two novel methods are reported for measuring octanol/water partition rates of pesticides. A liquid scintillation counting (LSC) method was developed for automated monitoring of 14 C-labeled pesticides partitioning in biphasic water/octanol cocktail systems with limited success. A high performance liquid chromatography (HPLC) method was developed for automated partition rate monitoring of several constituents in a pesticide mixture, simultaneously. The mean log Kow +/- SD determined from triplicate experimental runs were for: 2,4-D-DMA (2,4-dichlorophenoxyacetic acid dimethylamine), 0.65 +/- .17; Deet (N,N-diethyl-m-toluamide), 2.02 +/- .01; Guthion (O,O-dimethyl-S-(4-oxo-1,2,3-benzotriazin-3(4H)-ylmethyl) phosphorodithioate), 2.43 +/- .03; Methyl-Parathion (O,O-dimethyl-O-(p-nitrophenyl) phosphorothioate), 2.68 +/- .05; and Fenitrothion (O,O-dimethyl O-(4-nitro-m-tolyl) phosphorothioate), 3.16 +/- .03. A strong positive linear correlation (r = .9979) was obtained between log Kow and log k' (log Kow = 2.35 (log k') + 0.63). The advantages that this automated procedure has in comparison with the standard manual shake-flask procedure are discussed

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

Czech Academy of Sciences Publication Activity Database

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

2017-01-01

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

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

International Nuclear Information System (INIS)

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

2012-01-01

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

TECHNOLOGY FOR EFFICIENT USAGE OF HYDROCARBON-CONTAINING WASTE IN PRODUCTION OF MULTI-COMPONENT SOLID FUEL

Directory of Open Access Journals (Sweden)

B. M. Khroustalev

2016-01-01

Full Text Available The paper considers modern approaches to usage of hydrocarbon-containing waste as energy resources and presents description of investigations, statistic materials, analysis results on formation of hydrocarbon-containing waste in the Republic of Belarus. Main problems pertaining to usage of waste as a fuel and technologies for their application have been given in the paper. The paper describes main results of the investigations and a method for efficient application of viscous hydrocarbon-containing waste as an energy-packed component and a binding material while producing a solid fuel. A technological scheme, a prototype industrial unit which are necessary to realize a method for obtaining multi-component solid fuel are represented in the paper. A paper also provides a model of technological process with efficient sequence of technological operations and parameters of optimum component composition. Main factors exerting significant structure-formation influence in creation of structural composition of multi-component solid fuel have been presented in the paper. The paper gives a graphical representation of the principle for selection of mixture particles of various coarseness to form a solid fuel while using a briquetting method and comprising viscous hydrocarbon-containing waste. A dependence of dimensionless concentration g of emissions into atmosphere during burning of two-component solid fuel has been described in the paper. The paper analyzes an influence of the developed methodology for emission calculation of multi-component solid fuels and reveals a possibility to optimize the component composition in accordance with ecological function and individual peculiar features of fuel-burning equipment. Special features concerning storage and transportation, advantages and disadvantages, comparative characteristics, practical applicability of the developed multi-component solid fuel have been considered and presented in the paper. The paper

Solidification in Multicomponent Multiphase Systems (SIMMS)

Science.gov (United States)

Rex, S.; Hecht, U.

2005-06-01

The multiphase microstructures that evolve during the solidification of multicomponent alloys are attracting widespread interest for industrial applications and fundamental research.Thermodynamic databases are now well-established for many alloy systems. Thermodynamic calculations provide all the required information about phase equilibria, forming an integral part of both dedicated and comprehensive microstructure models. Among the latter, phase-field modelling has emerged as the method of choice. Solidification experiments are intended to trigger model development or to serve as benchmarks for model validation. For benchmarking, microgravity conditions offer a unique opportunity for avoiding buoyancy-induced convection and buoyancy forces in bulk samples. However, diffusion and the free-energy of interfaces and its anisotropy need to be determined.The measurement of chemical diffusivities in the liquid state can equally benefit from microgravity experiments.

CFD-DEM based numerical simulation of liquid-gas-particle mixture flow in dam break

Science.gov (United States)

Park, Kyung Min; Yoon, Hyun Sik; Kim, Min Il

2018-06-01

This study investigates the multiphase flow of a liquid-gas-particle mixture in dam break. The open source codes, OpenFOAM and CFDEMproject, were used to reproduce the multiphase flow. The results of the present study are compared with those of previous results obtained by numerical and experimental methods, which guarantees validity of present numerical method to handle the multiphase flow. The particle density ranging from 1100 to 2500 kg/m3 is considered to investigate the effect of the particle density on the behavior of the free-surface and the particles. The particle density has no effect on the liquid front, but it makes the particle front move with different velocity. The time when the liquid front reach at the opposite wall is independent of particle density. However, such time for particle front decrease as particle density increases, which turned out to be proportional to particle density. Based on these results, we classified characteristics of the movement by the front positions of the liquid and the particles. Eventually, the response of the free-surface and particles to particle density is identified by three motion regimes of the advancing, overlapping and delaying motions.

Photo polymerization-induced vertical phase separation and homeotropic alignment in liquid crystal and polymer mixtures

International Nuclear Information System (INIS)

Kang, Hyo; Joo, Sangwoo; Kang, Daeseung

2012-01-01

We presented a novel method for the homeotropic alignment of LC by using the irradiation of UV light on the LC/NOA65 mixture cell, in which the photo-initiated-polymerization-induced phase separation lowers the surface energy. When the amount of polymer content is sufficiently small, the gravel and network patterns were formed at the substrates via the vertical phase separation. We found that surface roughness plays an important role in the formation of the homeotropic alignment of LC. We also observed the alignment transition of the cells by varying the mixing ratio of LC/NOA65 or the UV radiation time. Furthermore, the present proposed method has great potential for application in display devices. For decades, studies on the alignment of liquid crystal (LC) molecules have been of significant interest due to their immediate applications for display devices and the intriguing physiochemical properties they exhibit at the surface of mixtures. Usually, homeotropic (or vertical) alignment, in which the long axes of the LC molecules are oriented in a direction perpendicular to the surface, is achieved by using surfactants such as lecithin, silanes or polyimide. Recently homeotropic alignment of liquid crystal molecules was achieved by irradiating photosensitive polymers, by doping nanoparticles into LC, by utilizing nano/micro patterns, or by incorporating self-assembled monolayers (SAMs). However, a clear understanding about the alignment mechanism is still elusive. In this paper, we report a novel method for homeotropic alignment of LC by utilizing the phase separation of LC/polymer mixtures

Liquid entrainment and off-take from the two-phase mixture surface in a vessel

International Nuclear Information System (INIS)

Kim, Chang Hyun; No, Hee Cheon

2003-01-01

In order to determine the bleed capacity of the Safety Depressurization System (SDS) of Advanced Power Reactor 1400 (APR1400) in the case of Total Loss of Feed Water (TLOFW), we performed an experimental study of liquid entrainment and liquid off-take from the swelled two-phase mixture surface in a vessel. A total of 220 experimental data on the entrainment and off-take are obtained using a test vessel with a height of 2.0m and an inner diameter of 0.3m, and a top break with a diameter of 0.05m. Two-phase mixture levels are measured by an ultrasonic sensor within ±1.77% with respect to the visual level data. Droplet entrainment data are obtained with and without the top break and are compared with the existing pool entrainment data. The present droplet entrainment data have higher values than those of the existing pool entrainment due to (a) the pulling toward the break of the liquid deentrained on the top wall of the vessel and (b) gas acceleration in the vicinity of the break. In the present experiment, droplet entrainment, Efg, strongly depends upon jg/h and is proportional to the 7th power of jg/h in the same way as the off-take data. The empirical correlation for the onset of off-take is developed in terms of the Froude number (Frg) at the break and the non-dimensional inception height (hb/d). This correlation shows agreement with the present experimental data within ±15%. The present off-take quality data show agreement with Schrock's off-take quality correlation with the r.m.s. error of 15.8%

Closure relations for the multi-species Euler system. Construction and study of relaxation schemes for the multi-species and multi-components Euler systems; Relations de fermeture pour le systeme des equations d'Euler multi-especes. Construction et etude de schemas de relaxation en multi-especes et en multi-constituants

Energy Technology Data Exchange (ETDEWEB)

Dellacherie, St. [CEA Saclay, Dir. de l' Energie Nucleaire DEN/SFNME/LMPE, Lab. de Modelisation Physique et de l' Enrichissement, 91 - Gif sur Yvette (France); Rency, N. [Paris-11 Univ., CNRS UMR 8628, 91 - Orsay (France)

2001-07-01

After having recalled the formal convergence of the semi-classical multi-species Boltzmann equations toward the multi-species Euler system (i.e. mixture of gases having the same velocity), we generalize to this system the closure relations proposed by B. Despres and by F. Lagoutiere for the multi-components Euler system (i.e. mixture of non miscible fluids having the same velocity). Then, we extend the energy relaxation schemes proposed by F. Coquel and by B. Perthame for the numerical resolution of the mono-species Euler system to the multi-species isothermal Euler system and to the multi-components isobar-isothermal Euler system. This allows to obtain a class of entropic schemes under a CFL criteria. In the multi-components case, this class of entropic schemes is perhaps a way for the treatment of interface problems and, then, for the treatment of the numerical mixture area by using a Lagrange + projection scheme. Nevertheless, we have to find a good projection stage in the multi-components case. At last, in the last chapter, we discuss, through the study of a dynamical system, about a system proposed by R. Abgrall and by R. Saurel for the numerical resolution of the multi-components Euler system.

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

Science.gov (United States)

Dunne, Lawrence J.; Manos, George

2018-03-01

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

Chemical ageing and transformation of diffusivity in semi-solid multi-component organic aerosol particles

Science.gov (United States)

Pfrang, C.; Shiraiwa, M.; Pöschl, U.

2011-07-01

Recent experimental evidence underlines the importance of reduced diffusivity in amorphous semi-solid or glassy atmospheric aerosols. This paper investigates the impact of diffusivity on the ageing of multi-component reactive organic particles approximating atmospheric cooking aerosols. We apply and extend the recently developed KM-SUB model in a study of a 12-component mixture containing oleic and palmitoleic acids. We demonstrate that changes in the diffusivity may explain the evolution of chemical loss rates in ageing semi-solid particles, and we resolve surface and bulk processes under transient reaction conditions considering diffusivities altered by oligomerisation. This new model treatment allows prediction of the ageing of mixed organic multi-component aerosols over atmospherically relevant timescales and conditions. We illustrate the impact of changing diffusivity on the chemical half-life of reactive components in semi-solid particles, and we demonstrate how solidification and crust formation at the particle surface can affect the chemical transformation of organic aerosols.

Chemical ageing and transformation of diffusivity in semi-solid multi-component organic aerosol particles

Directory of Open Access Journals (Sweden)

C. Pfrang

2011-07-01

Full Text Available Recent experimental evidence underlines the importance of reduced diffusivity in amorphous semi-solid or glassy atmospheric aerosols. This paper investigates the impact of diffusivity on the ageing of multi-component reactive organic particles approximating atmospheric cooking aerosols. We apply and extend the recently developed KM-SUB model in a study of a 12-component mixture containing oleic and palmitoleic acids. We demonstrate that changes in the diffusivity may explain the evolution of chemical loss rates in ageing semi-solid particles, and we resolve surface and bulk processes under transient reaction conditions considering diffusivities altered by oligomerisation. This new model treatment allows prediction of the ageing of mixed organic multi-component aerosols over atmospherically relevant timescales and conditions. We illustrate the impact of changing diffusivity on the chemical half-life of reactive components in semi-solid particles, and we demonstrate how solidification and crust formation at the particle surface can affect the chemical transformation of organic aerosols.

Nonlinear Raman spectroscopy of liquid crystals: orientational alignment and switching behaviour in a ferroelectric liquid crystal mixture

Science.gov (United States)

Grofcsik, Andras

Picosecond inverse Raman spectroscopy has been employed to probe the alignment behaviour and switching characteristics of a 6 mum thick ferroelectric liquid crystal based on a host mixture of fluorinated phenyl biphenylcarboxylates and a chiral dopant. Optical bistability is observed in the Raman signal on application of dc electric fields of opposite polarity. For particular polarities of the applied field, the Raman signals display a cos4theta dependence on the angle of rotation around the beam direction. Reorientational rate constants of 300 mus and 590 mus are observed for the aromatic core at the high-voltage limit for the rise and decay of the 1600 cm-1 Raman signal on application of a switching ac electric field.

Analysis of organic solvents and liquid mixtures using a fiber-tip evaporation sensor

Science.gov (United States)

Preter, Eyal; Donlagic, Denis; Artel, Vlada; Katims, Rachel A.; Sukenik, Chaim N.; Zadok, Avi

2014-05-01

The instantaneous size and rate of evaporation of pendant liquid droplets placed on the cleaved facet of a standard fiber are reconstructed based on reflected optical power. Using the evaporation dynamics, the relative contents of ethanol in ethanol-water binary mixtures are assessed with 1% precision and different blends of methanol in gasoline are properly recognized. The latter application, in particular, is significant for the use of alternative fuels in the automotive sector. Also, ten organic solvents are identified based on their evaporation from a fiber facet coated with a hydrophobic, selfassembled monolayer.

Microwave-Assisted Multicomponent Synthesis of Heterocycles

NARCIS (Netherlands)

Kruithof, A.; Ruijter, E.; Orru, R.V.A.

2011-01-01

Multicomponent reactions are valuable tools for the generation of diverse heterocycles. As in many fields or organic chemistry, microwave irradiation is rapidly replacing conventional heating methods in multicomponent chemistry. In this review, we present an overview of recent applications of the

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

International Nuclear Information System (INIS)

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

2012-01-01

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

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Combustion characteristics of nanoaluminum, liquid water, and hydrogen peroxide mixtures

Energy Technology Data Exchange (ETDEWEB)

Sabourin, J.L.; Yetter, R.A. [The Pennsylvania State University, Department of Mechanical and Nuclear Engineering, University Park, PA 16801 (United States); Risha, G.A. [The Pennsylvania State University, Division of Business and Engineering, Altoona, PA 16601 (United States); Son, S.F. [Purdue University, School of Mechanical Engineering, West Lafayette, IN 47907 (United States); Tappan, B.C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2008-08-15

An experimental investigation of the combustion characteristics of nanoaluminum (nAl), liquid water (H{sub 2}O{sub (l)}), and hydrogen peroxide (H{sub 2}O{sub 2}) mixtures has been conducted. Linear and mass-burning rates as functions of pressure, equivalence ratio ({phi}), and concentration of H{sub 2}O{sub 2} in H{sub 2}O{sub (l)} oxidizing solution are reported. Steady-state burning rates were obtained at room temperature using a windowed pressure vessel over an initial pressure range of 0.24 to 12.4 MPa in argon, using average nAl particle diameters of 38 nm, {phi} from 0.5 to 1.3, and H{sub 2}O{sub 2} concentrations between 0 and 32% by mass. At a nominal pressure of 3.65 MPa, under stoichiometric conditions, mass-burning rates per unit area ranged between 6.93 g/cm{sup 2} s (0% H{sub 2}O{sub 2}) and 37.04 g/cm{sup 2} s (32% H{sub 2}O{sub 2}), which corresponded to linear burning rates of 9.58 and 58.2 cm/s, respectively. Burning rate pressure exponents of 0.44 and 0.38 were found for stoichiometric mixtures at room temperature containing 10 and 25% H{sub 2}O{sub 2}, respectively, up to 5 MPa. Burning rates are reduced above {proportional_to}5 MPa due to the pressurization of interstitial spaces of the packed reactant mixture with argon gas, diluting the fuel and oxidizer mixture. Mass burning rates were not measured above {proportional_to}32% H{sub 2}O{sub 2} due to an anomalous burning phenomena, which caused overpressurization within the quartz sample holder, leading to tube rupture. High-speed imaging displayed fingering or jetting ahead of the normal flame front. Localized pressure measurements were taken along the sample length, determining that the combustion process proceeded as a normal deflagration prior to tube rupture, without significant pressure buildup within the tube. In addition to burning rates, chemical efficiencies of the combustion reaction were determined to be within approximately 10% of the theoretical maximum under all conditions

A new correlation for nucleate pool boiling of aqueous mixtures

International Nuclear Information System (INIS)

Thome, J.R.; Shakir, S.

1987-01-01

A new mixture boiling correlation was developed for nucleate pool boiling of aqueous mixtures on plain, smooth tubes. The semi-empirical correlation models the rise in the local bubble point temperature in a mixture caused by the preferential evaporation of the more volatile component during bubble growth. This rise varies from zero at low heat fluxes (where only single-phase natural convection is present) up to nearly the entire boiling range at the peak heat flux (where latent heat transport is dominant). The boiling range, which is the temperature difference between the dew point and bubble point of a mixture, is used to characterize phase equilibrium effects. An exponential term models the rise in the local bubble point temperature as a function of heat flux. The correlation was compared against binary mixture boiling data for ethanol-water, methanol-water, n-propanol-water, and acetone-water. The majority of the data was predicted to within 20%. Further experimental research is currently underway to obtain multicomponent boiling data for aqueous mixtures with up to five components and for wider boiling ranges

Effect of interaction between inclusions in a gas-liquid mixture on interphase heat and mass transfer

International Nuclear Information System (INIS)

Nigmatulin, B.I.; Kroshilin, A.E.; Kroshilin, V.E.

1979-01-01

The effect of interaction between inclusions in a gas-liquid mixture on interphase heat and mass transfer is analyzed. It is taken into account that inclusions (bubbles or drops) are not in a pure carrier phase, but in a disperse medium, mean properties of which are determined by the presence of other inclusions in it and by a temperature field around them. The consideration is carried out in the framework of two model of monodisperse mixture, i.e. that with a chaotic distribution of inclusions, and that with a regular distribution, when the distance between centers of inclusions is fixed. The correlation functions method is shown to be effective for the both models. Mean temperature fields around inclusions are determined along with the intensity of interphase heat and mass transfer. The dependences obtained are in a satisfactory agreement with experimental data. The dependence of interphase heat and mass transfer on the structure of disperse mixture is analyzed

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

International Nuclear Information System (INIS)

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

2017-01-01

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

Characteristics of liquid product from the pyrolysis of waste plastic mixture at low and high temperatures: Influence of lapse time of reaction

International Nuclear Information System (INIS)

Lee, Kyong-Hwan; Shin, Dae-Hyun

2007-01-01

Pyrolysis of a waste plastic mixture (high-density polyethylene: low-density polyethylene: polypropylene: polystyrene = 3:2:3:1) into a liquid product was carried out in a stirred semi-batch reactor at low (350 deg. C) and high (400 deg. C) temperatures. The effect of lapse time of reaction in the reactor and also degradation temperature on the characteristics of the liquid product from pyrolysis of the mixture was investigated. Liquid products were described by cumulative amount distribution, paraffin, olefin, naphthene and aromatic (PONA) distribution and molecular weight distribution. Their characteristic was quite differed with a lapse time of reaction and also at a low and high degradation temperatures, because of the different physicochemical properties of the plastic types in the mixture. With increase of lapse time of reaction, the order for the main products in PONA components obtained at 350 deg. C was firstly aromatic products and then olefin products, while at 400 deg. C the order was firstly aromatic products, then olefin products and finally paraffin products. The experiments also showed from the molecular weight distribution of liquid PONA components that the paraffin and olefin products had a wide distribution by mainly random scission of polymer, but in the case of olefin products were produced by an end-chain scission mechanism as well as random scission mechanism, as evidenced by much more light olefin products. This phenomenon was evident at a higher degradation temperature. Also, both the light olefin and naphthene products with a molecular weight of around 120, as a main product, showed a similar trend as a function of lapse time, which had a maximum fraction at 343 min (at 350 deg. C) and 83 min (at 400 deg. C). Among PONA components, the highest concentrations of aromatic products were obtained with a molecular weight of around 100 at the fastest lapse time of reaction, regardless of degradation temperature. It was concluded that the

Characteristics of liquid product from the pyrolysis of waste plastic mixture at low and high temperatures: influence of lapse time of reaction.

Science.gov (United States)

Lee, Kyong-Hwan; Shin, Dae-Hyun

2007-01-01

Pyrolysis of a waste plastic mixture (high-density polyethylene: low-density polyethylene: polypropylene: polystyrene = 3:2:3:1) into a liquid product was carried out in a stirred semi-batch reactor at low (350 degrees C) and high (400 degrees C) temperatures. The effect of lapse time of reaction in the reactor and also degradation temperature on the characteristics of the liquid product from pyrolysis of the mixture was investigated. Liquid products were described by cumulative amount distribution, paraffin, olefin, naphthene and aromatic (PONA) distribution and molecular weight distribution. Their characteristic was quite differed with a lapse time of reaction and also at a low and high degradation temperatures, because of the different physicochemical properties of the plastic types in the mixture. With increase of lapse time of reaction, the order for the main products in PONA components obtained at 350 degrees C was firstly aromatic products and then olefin products, while at 400 degrees C the order was firstly aromatic products, then olefin products and finally paraffin products. The experiments also showed from the molecular weight distribution of liquid PONA components that the paraffin and olefin products had a wide distribution by mainly random scission of polymer, but in the case of olefin products were produced by an end-chain scission mechanism as well as random scission mechanism, as evidenced by much more light olefin products. This phenomenon was evident at a higher degradation temperature. Also, both the light olefin and naphthene products with a molecular weight of around 120, as a main product, showed a similar trend as a function of lapse time, which had a maximum fraction at 343 min (at 350 degrees C) and 83 min (at 400 degrees C). Among PONA components, the highest concentrations of aromatic products were obtained with a molecular weight of around 100 at the fastest lapse time of reaction, regardless of degradation temperature. It was

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

Directory of Open Access Journals (Sweden)

P. Paul Divakar

2012-01-01

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

Generalized method for calculation and prediction of vapour-liquid equilibria at high pressures

Energy Technology Data Exchange (ETDEWEB)

Drahos, J; Wichterle, I; Hala, E

1978-02-01

Following the approaches of K.C. Chao and J.D. Seader (see Gas Abstr. 18,24 (1962) Jan.) and B.I. Lee, J.H. Erbar, and W.C. Edmister (see Gas Abst. 29, 73-0331), the Czechoslovak Academy of Sciences developed a generalized method for prediction of vapor-liquid equilibria in hydrocarbon mixtures containing some nonhydrocarbon gases at high pressures. The method proposed is based on three equations: (1) a generalized equation of state for vapor-phase calculations; (2) a generalized expression for the pure-liquid fugacity coefficient; and (3) an activity coefficient expression based on a surface modification of the regular solution model. The equations used contain only one partially generalized binary parameter, which was evaluated from experimental K-value data. Researchers tested the proposed method by computing K-values and pressures in binary and multicomponent systems consisting of 13 hydrocarbons and 3 nonhydrocarbon gases. The results show that the method is applicable over a wide range of conditions with a degree of accuracy comparable with that of more complicated methods.

Visualization and measurement of liquid velocity field of gas-liquid metal two-phase flow using neutron radiography

International Nuclear Information System (INIS)

Saito, Yasushi; Suzuki, Tohru; Matsubayashi, Masahito

2000-01-01

In a core melt accident of a fast breeder reactor, a possibility of re-criticality is anticipated in the molten fuel-steel mixture pool. One of the mechanisms to suppress the re-criticality is the boiling of steel in the molten fuel-steel mixture pool because of the negative void reactivity effect. To evaluate the reactivity change due to boiling, it is necessary to know the characteristics of gas-liquid two-phase flow in the molten fuel-steel mixture pool. For this purpose, boiling bubbles in a molten fuel-steel mixture pool were simulated by adiabatic gas bubbles in a liquid metal pool to study the basic characteristics of gas-liquid metal two-phase mixture. Visualization of the two-phase mixture and measurements of liquid phase velocity and void fraction were conducted by using neutron radiography and image processing techniques. From these measurements, the basic characteristics of gas-liquid metal two-phase mixture were clarified. (author)

Composition inversion in mixtures of binary colloids and polymer

Science.gov (United States)

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

2018-05-01

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

Thermophysical properties of biodiesel and related systems. Part I. Vapour–liquid equilibrium at low pressures of binary and ternary systems involving methanol, ethanol, glycerol, water and NaCl

International Nuclear Information System (INIS)

Veneral, Josamaique G.; Benazzi, Tassio; Mazutti, Marcio A.; Voll, Fernando A.P.; Cardozo-Filho, Lúcio; Corazza, Marcos L.; Guirardello, Reginaldo; Vladimir Oliveira, J.

2013-01-01

Highlights: ► Experimental vapour–liquid equilibrium data of multicomponent mixtures of biodiesel-related systems. ► Othmer-type ebulliometer in the pressure range of 6.7 to 66.7 kPa. ► Experimental data satisfactorily represented by the UNIQUAC model. -- Abstract: Experimental vapour–liquid equilibrium data of several binary mixtures (methanol + glycerol), (ethanol + glycerol) and (glycerol + water) and ternary (methanol + glycerol + water), (ethanol + glycerol + water) and (water + glycerol + NaCl) were obtained over the pressure range of 6.7 kPa to 66.7 kPa through an Othmer-type ebulliometer, allowing the construction of temperature – mass fraction and pressure – temperature diagrams. It is shown that the systems without NaCl were satisfactorily represented by the UNIQUAC model with good agreement between theory and experimental results. It was observed that alcohol concentrations lower than 10 wt% increase the phase transition temperature. The systems investigated show positive deviations in relation to Raoult’s law. Results presented in this work may be relevant in process design towards efficient recovering of components in the biodiesel down-stream processes

The effect of the alkyl chain length on physicochemical features of (ionic liquids + γ-butyrolactone) binary mixtures

International Nuclear Information System (INIS)

Papović, Snežana; Bešter-Rogač, Marija; Vraneš, Milan; Gadžurić, Slobodan

2016-01-01

Highlights: • Influence of alkyl substituent length on IL properties was studied. • Nature of interactions between studied [C_nC_1im][NTf_2] and GBL were discussed. • Angell strength parameter indicates [C_nC_1im][NTf_2] are fragile liquids. • ILs properties regularly change with increase of the alkyl chain length. • Absence of GBL self-association upon addition of IL is observed. - Abstract: Densities and viscosities were determined and analysed for γ-butyrolactone (GBL) binary mixtures with 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids (where alkyl = ethyl, hexyl, octyl) as a function of temperature at atmospheric pressure (p = 0.1 MPa) and over the whole composition range. Excess molar volumes have been calculated from the experimental densities and were fitted using Redlich–Kister’s polynomial equation. Other volumetric parameters have been also calculated in order to obtain information about interactions between GBL and imidazolium based ionic liquids with different alkyl chain length. From the viscosity measurements, the Angell strength parameter was calculated for pure ionic liquids indicating that all investigated electrolytes are “fragile” liquids.

Rogue waves in the multicomponent Mel'nikov system and ...

Indian Academy of Sciences (India)

By virtue of the bilinear method and the KP hierarchy reduction technique, exact explicit rational solutions of the multicomponent Mel'nikov equation and the multicomponent Schrödinger–Boussinesq equation are constructed, which contain multicomponent short waves and single-component long wave. For the ...

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

Science.gov (United States)

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

2018-06-01

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

Study of the Vapor-Liquid Coexistence Curve and the Critical Curve for Nonazeotropic Refrigerant Mixture R152a + R114 System

Science.gov (United States)

Kabata, Yasuo; Higashi, Yukihiro; Uematsu, Masahiko; Watanabe, Koichi

Measurements of the vapor-liquid coexistence curve in the critical region for the refrigerant mixture of R152a (CH3CHF2: 1, l-difluoroethane) +R 114 (CCIF2CCIF2 :1, 2-dichloro-1, 1, 2, 2-tetrafluoroethane) system were made by visual observation of the disappearance of the meniscus at the vapor-liquid interface within an optical cell. Forty-eight saturated densities along the vapor-liquid coexistence curve between 204 and 861 kg·m-3 for five different compositions of 10, 20, 50, 80 and 90 wt% R 152a were obtained in the temperature range 370 to 409 K. The experimental errors of temperature, density, and mass fraction were estimated within ±10mK, ±0.5% and +0.05 %, respectively. On the basis of these measurements, the critical parameters of five different compositions for the R 152a +R 114 system were determined in consideration of the meniscus disappearance level as well as intensity of the critical opalescence. In accordance with the previous results of three other refrigerant mixtures, i.e., R 12 +R 22 system, R 22 +R 114 system and R 13B1 + R 114 system, the coexistence curve and critical curve on the temperature-density diagram for binary refrigerant mixtures were discussed. In addition, correlations of its composition dependence for this system were proposed.

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

Directory of Open Access Journals (Sweden)

Benziane M.

2013-07-01

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

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Modeling of liquid phases

CERN Document Server

Soustelle, Michel

2015-01-01

This book is part of a set of books which offers advanced students successive characterization tool phases, the study of all types of phase (liquid, gas and solid, pure or multi-component), process engineering, chemical and electrochemical equilibria, and the properties of surfaces and phases of small sizes. Macroscopic and microscopic models are in turn covered with a constant correlation between the two scales. Particular attention has been given to the rigor of mathematical developments. This second volume in the set is devoted to the study of liquid phases.

On modeling of structured multiphase mixtures

International Nuclear Information System (INIS)

Dobran, F.

1987-01-01

The usual modeling of multiphase mixtures involves a set of conservation and balance equations of mass, momentum, energy and entropy (the basic set) constructed by an averaging procedure or postulated. The averaged models are constructed by averaging, over space or time segments, the local macroscopic field equations of each phase, whereas the postulated models are usually motivated by the single phase multicomponent mixture models. In both situations, the resulting equations yield superimposed continua models and are closed by the constitutive equations which place restrictions on the possible material response during the motion and phase change. In modeling the structured multiphase mixtures, the modeling of intrinsic motion of grains or particles is accomplished by adjoining to the basic set of field equations the additional balance equations, thereby placing restrictions on the motion of phases only within the imposed extrinsic and intrinsic sources. The use of the additional balance equations has been primarily advocated in the postulatory theories of multiphase mixtures and are usually derived through very special assumptions of the material deformation. Nevertheless, the resulting mixture models can predict a wide variety of complex phenomena such as the Mohr-Coulomb yield criterion in granular media, Rayleigh bubble equation, wave dispersion and dilatancy. Fundamental to the construction of structured models of multiphase mixtures are the problems pertaining to the existence and number of additional balance equations to model the structural characteristics of a mixture. Utilizing a volume averaging procedure it is possible not only to derive the basic set of field equation discussed above, but also a very general set of additional balance equations for modeling of structural properties of the mixture

Predictive Local Composition Models for Solid/Liquid Equilibrium in n-Alkane Systems: Wilson Equation for Multicomponent Systems

DEFF Research Database (Denmark)

Coutinho, João A.P.; Stenby, Erling Halfdan

1996-01-01

The predictive local composition model is applied to multicomponent hydrocarbon systems with long-chain n-alkanes as solutes. The results show that it can successfully be extended to highorder systems and accurately predict the solid appearance temperature, also known as cloud point, in solutions...

New and extended parameterization of the thermodynamic model AIOMFAC: calculation of activity coefficients for organic-inorganic mixtures containing carboxyl, hydroxyl, carbonyl, ether, ester, alkenyl, alkyl, and aromatic functional groups

Directory of Open Access Journals (Sweden)

A. Zuend

2011-09-01

algorithms. A number of exemplary calculations for systems containing atmospherically relevant aerosol components are shown. Amongst others, we discuss aqueous mixtures of ammonium sulfate with dicarboxylic acids and with levoglucosan. Overall, the new parameterization of AIOMFAC agrees well with a large number of experimental datasets. However, due to various reasons, for certain mixtures important deviations can occur. The new parameterization makes AIOMFAC a versatile thermodynamic tool. It enables the calculation of activity coefficients of thousands of different organic compounds in organic-inorganic mixtures of numerous components. Models based on AIOMFAC can be used to compute deliquescence relative humidities, liquid-liquid phase separations, and gas-particle partitioning of multicomponent mixtures of relevance for atmospheric chemistry or in other scientific fields.

Solid-Liquid Equilibria for Many-component Mixtures Using Cubic-Plus-Association (CPA) equation of state

DEFF Research Database (Denmark)

Fettouhi, André; Thomsen, Kaj

2010-01-01

In the creation of liquefied natural gas the formation of solids play a substantial role, hence detailed knowledge is needed about solid-liquid equilibria (SLE). In this abstract we shortly summarize the work we have carried out at CERE over the past year with SLE for many-component mixtures usin...... the Cubic-Plus-Association (CPA) equation of state. Components used in this work are highly relevant to the oil and gas industry and include light and heavy hydrocarbons, alcohols, water and carbon dioxide....

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.

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

International Nuclear Information System (INIS)

Sobolev, S.L.

2014-01-01

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

Theoretical approach in optimization of stability of the multicomponent solid waste form

International Nuclear Information System (INIS)

Raicevic, S.; Plecas, I.; Mandic, M.

1998-01-01

Chemical precipitation of radionuclides and their immobilization into the solid matrix represents an important approach in the radioactive wastewater treatment. Unfortunately, because of the complexity of the system, optimization of this process in terms of its efficacy and safety represents a serious practical problem, even in treatment of the monocomponent nuclear waste. This situation is additionally complicated in the case of the polycomponent nuclear waste because of the synergic effects of interactions between the radioactive components and the solid matrix. Recently, we have proposed a general theoretical approach for optimization of the process of precipitation and immobilization of metal impurities by the solid matrix. One of the main advantages of this approach represents the possibility of treatment of the multicomponent liquid waste, immobilized by the solid matrix. This approach was used here for investigation of the stability of the system hydroxyapatite (HAP) - Pb/Cd, which was selected as a model multicomponent waste system. In this analysis, we have used a structurally dependent term of the cohesive energy as a stability criterion. (author)

Induced liquid-crystalline ordering in solutions of stiff and flexible amphiphilic macromolecules: Effect of mixture composition

International Nuclear Information System (INIS)

Glagolev, Mikhail K.; Vasilevskaya, Valentina V.; Khokhlov, Alexei R.

2016-01-01

Impact of mixture composition on self-organization in concentrated solutions of stiff helical and flexible macromolecules was studied by means of molecular dynamics simulation. The macromolecules were composed of identical amphiphilic monomer units but a fraction f of macromolecules had stiff helical backbones and the remaining chains were flexible. In poor solvents the compacted flexible macromolecules coexist with bundles or filament clusters from few intertwined stiff helical macromolecules. The increase of relative content f of helical macromolecules leads to increase of the length of helical clusters, to alignment of clusters with each other, and then to liquid-crystalline-like ordering along a single direction. The formation of filament clusters causes segregation of helical and flexible macromolecules and the alignment of the filaments induces effective liquid-like ordering of flexible macromolecules. A visual analysis and calculation of order parameter relaying the anisotropy of diffraction allow concluding that transition from disordered to liquid-crystalline state proceeds sharply at relatively low content of stiff components.

Shear-induced phase changes in mixtures

International Nuclear Information System (INIS)

Romig, K.D.; Hanley, H.J.M.

1986-01-01

A thermodynamic theory to account for the behavior of liquid mixtures exposed to a shear is developed. One consequence of the theory is that shear-induced phase changes are predicted. The theory is based on a thermodynamics that includes specifically the shear rate in the formalism and is applied to mixtures by a straightforward modification of the corresponding states, conformalsolution approach. The approach is general but is used here for a mixture of Lennard-Jones particles with a Lennard-Jones equation of state as a reference fluid. The results are discussed in the context of the Scott and Van Konynenberg phase classification. It is shown that the influence of a shear does affect substantially the type of the phase behavior. Results from the model mixture are equated loosely with those from real polymeric liquids

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

Science.gov (United States)

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

2015-11-01

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

Measurement of viscosity of gaseous mixtures at atmospheric pressure

Science.gov (United States)

Singh, J. J.; Mall, G. H.; Chegini, H.

1986-01-01

Coefficients of viscosity of various types of gas mixtures, including simulated natural-gas samples, have been measured at atmospheric pressure and room temperature using a modified capillary tube method. Pressure drops across the straight capillary tube section of a thermal mass flowmeter were measured for small, well-defined, volume flow rates for the test gases and for standard air. In this configuration, the flowmeter provides the volumetric flow rates as well as a well-characterized capillary section for differential pressure measurements across it. The coefficients of viscosity of the test gases were calculated using the reported value of 185.6 micro P for the viscosity of air. The coefficients of viscosity for the test mixtures were also calculated using Wilke's approximation of the Chapman-Enskog (C-E) theory. The experimental and calculated values for binary mixtures are in agreement within the reported accuracy of Wilke's approximation of the C-E theory. However, the agreement for multicomponent mixtures is less satisfactory, possible because of the limitations of Wilkes's approximation of the classical dilute-gas state model.

(Vapour + liquid) equilibria for binary and ternary mixtures of 2-propanol, tetrahydropyran, and 2,2,4-trimethylpentane at P = 101.3 kPa

International Nuclear Information System (INIS)

Lin, Dun-Yi; Tu, Chein-Hsiun

2012-01-01

Highlights: ► We report the VLE data at P = 101.3 kPa involving a cyclic ether. ► The activity coefficients of mixtures were obtained from modified Raoult’s law. ► The VLE data were correlated by four liquid activity coefficient models. ► The ternary VLE data were predicted from binary parameters of the four models. - Abstract: (Vapour + liquid) equilibrium (VLE) at P = 101.3 kPa have been determined for a ternary system (2-propanol + tetrahydropyran + 2,2,4-trimethylpentane) and its constituent binary systems (2-propanol + tetrahydropyran, 2-propanol + 2,2,4-trimethylpentane), and (tetrahydropyran + 2,2,4-trimethylpentane). Analysis of VLE data reveals that two binary systems (2-propanol + tetrahydropyran) and (2-propanol + 2,2,4-trimethylpentane) have a minimum boiling azeotrope. No azeotrope was found for the ternary system. The activity coefficients of liquid mixtures were obtained from the modified Raoult’s law and were used to calculate the reduced excess molar Gibbs free energy (g E /RT). Thermodynamic consistency tests were performed for all VLE data using the Van Ness direct test for the binary systems and the test of McDermott–Ellis as modified by Wisniak and Tamir for the ternary system. The VLE data of the binary mixtures were correlated using the three-suffix Margules, Wilson, NRTL, and UNIQUAC activity-coefficient models. The models with their best-fitted interaction parameters of the binary systems were used to predict the ternary (vapour + liquid) equilibrium.

An Improved Computational Method for the Calculation of Mixture Liquid-Vapor Critical Points

Science.gov (United States)

Dimitrakopoulos, Panagiotis; Jia, Wenlong; Li, Changjun

2014-05-01

Knowledge of critical points is important to determine the phase behavior of a mixture. This work proposes a reliable and accurate method in order to locate the liquid-vapor critical point of a given mixture. The theoretical model is developed from the rigorous definition of critical points, based on the SRK equation of state (SRK EoS) or alternatively, on the PR EoS. In order to solve the resulting system of nonlinear equations, an improved method is introduced into an existing Newton-Raphson algorithm, which can calculate all the variables simultaneously in each iteration step. The improvements mainly focus on the derivatives of the Jacobian matrix, on the convergence criteria, and on the damping coefficient. As a result, all equations and related conditions required for the computation of the scheme are illustrated in this paper. Finally, experimental data for the critical points of 44 mixtures are adopted in order to validate the method. For the SRK EoS, average absolute errors of the predicted critical-pressure and critical-temperature values are 123.82 kPa and 3.11 K, respectively, whereas the commercial software package Calsep PVTSIM's prediction errors are 131.02 kPa and 3.24 K. For the PR EoS, the two above mentioned average absolute errors are 129.32 kPa and 2.45 K, while the PVTSIM's errors are 137.24 kPa and 2.55 K, respectively.

A density model based on the Modified Quasichemical Model and applied to the (NaCl + KCl + ZnCl2) liquid

International Nuclear Information System (INIS)

Ouzilleau, Philippe; Robelin, Christian; Chartrand, Patrice

2012-01-01

Highlights: ► A model for the density of multicomponent inorganic liquids. ► The density model is based on the Modified Quasichemical Model. ► Application to the (NaCl + KCl + ZnCl 2 ) ternary liquid. ► A Kohler–Toop-like asymmetric interpolation method was used. - Abstract: A theoretical model for the density of multicomponent inorganic liquids based on the Modified Quasichemical Model has been presented previously. By introducing in the Gibbs free energy of the liquid phase temperature-dependent molar volume expressions for the pure components and pressure-dependent excess parameters for the binary (and sometimes higher-order) interactions, it is possible to reproduce, and eventually predict, the molar volume and the density of the multicomponent liquid phase using standard interpolation methods. In the present article, this density model is applied to the (NaCl + KCl + ZnCl 2 ) ternary liquid and a Kohler–Toop-like asymmetric interpolation method is used. All available density data for the (NaCl + KCl + ZnCl 2 ) liquid were collected and critically evaluated, and optimized pressure-dependent model parameters have been found. This new volumetric model can be used with Gibbs free energy minimization software, to calculate the molar volume and the density of (NaCl + KCl + ZnCl 2 ) ternary melts.

Isobaric (vapour + liquid) equilibria for the (1-pentanol + propionic acid) binary mixture at (53.3 and 91.3) kPa

International Nuclear Information System (INIS)

Mohsen-Nia, M.; Memarzadeh, M.R.

2010-01-01

Isobaric (vapour + liquid) equilibrium measurements have been reported for the binary mixture of (1-pentanol + propionic acid) at (53.3 and 91.3) kPa. Liquid phase activity coefficients were calculated from the equilibrium data. The thermodynamic consistency of the experimental results was checked using the area test and direct test methods. According to these criteria, the measured (vapour + liquid) equilibrium results were found to be consistent thermodynamically. The obtained results showed a maximum boiling temperature azeotrope at both pressures studied. The measured equilibrium results were satisfactorily correlated by the models of Wilson, UNIQUAC, and NRTL activity coefficients. The results obtained indicate that the performance of the NRTL model is superior to the Wilson and UNIQUAC models for correlating the measured isobaric (vapour + liquid) equilibrium data.

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Muonium radicals in benzene-styrene mixtures

International Nuclear Information System (INIS)

Ng, B.W.; Stadlbauer, J.W.; Walker, D.C.

1984-01-01

Muonium radicals were observed through their μ + SR precession frequencies in high transverse magnetic fields in pure benzene, pure styrene and their mixtures, all as liquids at room temperature. In benzene-styrene mixtures, the radicals obtained in each pure liquid are both present, so no slow (10 -9 -10 -5 s) intermolecular exchange occurs; but strong selectivity was found with the formation of the radical from styrene being about eight-times more probable than the radical from benzene. (Auth.)

The analog of Blanc's law for drift velocities of electrons in gas mixtures in weakly ionized plasma

International Nuclear Information System (INIS)

Chiflikian, R.V.

1995-01-01

The analog of Blanc's law for drift velocities of electrons in multicomponent gas mixtures in weakly ionized spatially homogeneous low-temperature plasma is derived. The obtained approximate-analytical expressions are valid for average electron energy in the 1--5 eV range typical for plasma conditions of low-pressure direct current (DC) discharges. The accuracy of these formulas is ±5%. The analytical criterion of the negative differential conductivity (NDC) of electrons in binary mixtures of gases is obtained. NDC of electrons is predicted in He:Kr and He:Xe rare gas mixtures. copyright 1995 American Institute of Physics

Fingerprint analysis, multi-component quantitation, and antioxidant activity for the quality evaluation of Salvia miltiorrhiza var. alba by high-performance liquid chromatography and chemometrics.

Science.gov (United States)

Zhang, Danlu; Duan, Xiaoju; Deng, Shuhong; Nie, Lei; Zang, Hengchang

2015-10-01

Salvia miltiorrhiza Bge. var. alba C.Y. Wu and H.W. Li has wide prospects in clinical practice. A useful comprehensive method was developed for the quality evaluation of S. miltiorrhiza var. alba by three quantitative parameters: high-performance liquid chromatography fingerprint, ten-component contents, and antioxidant activity. The established method was validated for linearity, precision, repeatability, stability, and recovery. Principal components analysis and hierarchical clustering analysis were both used to evaluate the quality of the samples from different origins. The results showed that there were category discrepancies in quality of S. miltiorrhiza var. alba samples according to the three quantitative parameters. Multivariate linear regression was adopted to explore the relationship between components and antioxidant activity. Three constituents, namely, danshensu, rosmarinic acid, and salvianolic acid B, significantly correlated with antioxidant activity, and were successfully elucidated by the optimized multivariate linear regression model. The combined use of high-performance liquid chromatography fingerprint analysis, simultaneous multicomponent quantitative analysis, and antioxidant activity for the quality evaluation of S. miltiorrhiza var. alba is a reliable, comprehensive, and promising approach, which might provide a valuable reference for other herbal products in general to improve their quality control. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical kinetics of detonation in some liquid mixtures

Energy Technology Data Exchange (ETDEWEB)

Raikova, Vlada M.; Likholatov, Evgeny A. [Mendeleev University of Chemical Technology, Moscow (Russian Federation)

2005-09-01

The main objective of this work is to study the chemical kinetics of detonation reactions in some nitroester mixtures and solutions of nitrocompounds in concentrated nitric acid. The main source of information on chemical kinetics in the detonation wave was the experimental dependence of failure diameter on composition of mixtures. Calculations were carried out in terms of classic theory of Dremin using the SGKR computer code. Effective values for the activation energies and pre-exponential factors for detonation reactions in the mixtures under investigation have been defined. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

New theories for smectic and nematic liquid-crystal polymers: Backbone LCPs [liquid crystalline polymers] and their mixtures and side-chain LCPs

International Nuclear Information System (INIS)

Dowell, F.

1987-01-01

A summary of predictions and explanations from statistical-physics theories for both backbone and side-chain liquid crystalline polymers (LCPs) and for mixtures with backbone LCPs are presented. Trends in the thermodynamic and molecular ordering properties have been calculated as a function of pressure, density, temperature, and molecule chemical structures (including degree of polymerization and the following properties of the chemical structures of the repeat units: lengths and shapes, intra-chain rotation energies, dipole moments, site-site polarizabilities and Lennard-Jones potentials, etc.) in nematic and multiple smectic-A LC phases and in the isotropic liquid phase. The theoretical results are found to be in good agreement with existing experimental data. These theories can also be applied to combined LCPs. Since these theories have no ad hoc or arbitrarily adjustable parameters, these theories can be used to design new LCPs and new solvents as well as to predict and explain properties. 27 refs., 4 tabs

Silica-supported ionic liquid as highly efficient catalyst for one-pot ...

Indian Academy of Sciences (India)

4. Conclusion. A novel multicomponent approach for the synthesis of a series of new acenaphthofuran derivatives utilizing the supported ionic liquid catalyst has been elaborated. The efficient catalysing of used ionic liquid in the synthesis of acenaphtho[1,2-b]furans led to high chemical yields as well as short reaction times.

Multicomponent mixed dopant optimization for rapid screening of polycyclic aromatic hydrocarbons using ultra high performance liquid chromatography coupled to atmospheric pressure photoionization high-resolution mass spectrometry

KAUST Repository

Sioud, Salim; Amad, Maan H.; Al-Talla, Zeyad

2012-01-01

with water-soluble organic solvents. In order to achieve a more efficient and less toxic dopant, a multicomponent mixed dopant was explored. METHODS A multicomponent mixed dopant for non-targeted rapid screening of polycyclic aromatic hydrocarbons (PAHs

Improved Oral Bioavailability Using a Solid Self-Microemulsifying Drug Delivery System Containing a Multicomponent Mixture Extracted from Salvia miltiorrhiza

Directory of Open Access Journals (Sweden)

Xiaolin Bi

2016-04-01

Full Text Available The active ingredients of salvia (dried root of Salvia miltiorrhiza include both lipophilic (e.g., tanshinone IIA, tanshinone I, cryptotanshinone and dihydrotanshinone I and hydrophilic (e.g., danshensu and salvianolic acid B constituents. The low oral bioavailability of these constituents may limit their efficacy. A solid self-microemulsifying drug delivery system (S-SMEDDS was developed to load the various active constituents of salvia into a single drug delivery system and improve their oral bioavailability. A prototype SMEDDS was designed using solubility studies and phase diagram construction, and characterized by self-emulsification performance, stability, morphology, droplet size, polydispersity index and zeta potential. Furthermore, the S-SMEDDS was prepared by dispersing liquid SMEDDS containing liposoluble extract into a solution containing aqueous extract and hydrophilic polymer, and then freeze-drying. In vitro release of tanshinone IIA, salvianolic acid B, cryptotanshinone and danshensu from the S-SMEDDS was examined, showing approximately 60%–80% of each active component was released from the S-SMEDDS in vitro within 20 min. In vivo bioavailability of these four constituents indicated that the S-SMEDDS showed superior in vivo oral absorption to a drug suspension after oral administration in rats. It can be concluded that the novel S-SMEDDS developed in this study increased the dissolution rate and improved the oral bioavailability of both lipophilic and hydrophilic constituents of salvia. Thus, the S-SMEDDS can be regarded as a promising new method by which to deliver salvia extract, and potentially other multicomponent drugs, by the oral route.

Determination and correlation thermodynamic models for solid–liquid equilibrium of the Nifedipine in pure and mixture organic solvents

International Nuclear Information System (INIS)

Wu, Gang; Hu, Yonghong; Gu, Pengfei; Yang, Wenge; Wang, Chunxiao; Ding, Zhiwen; Deng, Renlun; Li, Tao; Hong, Housheng

2016-01-01

Highlights: • The solubility increased with increasing temperature. • The data were fitted using the modified Apelblat equation in pure solvents. • The data were fitted using the CNIBS/R-K model in binary solvent mixture. - Abstract: Knowledge of thermodynamic parameters on corresponding solid-liquid equilibrium of nifedipine in different solvents is essential for a preliminary study of pharmaceutical engineering and industrial applications. In this paper, a gravimetric method was used to correct the solid-liquid equilibrium of nifedipine in methanol, ethanol, 1-butanol, acetone, acetonitrile, ethyl acetate and tetrahydrofuran pure solvents as well as in the (tetrahydrofuran + acetonitrile) mixture solvents at temperatures from 278.15 K to 328.15 K under 0.1 MPa. For the temperature range investigation, the solubility of nifedipine in the solvents increased with increasing temperature. The solubility of nifedipine in tetrahydrofuran is superior to other selected pure solvents. The modified Apelblat model, the Buchowski-Ksiazaczak λh model, and the ideal model were adopted to describe and predict the change tendency of solubility. Computational results showed that the modified Apelblat model stood out to be more suitable with the higher accuracy. The solubility values were fitted using a modified Apelblat model, a variant of the combined nearly ideal binary solvent/Redich-Kister (CNIBS/R-K) model and Jouyban-Acree model in (tetrahydrofuran + acetonitrile) binary solvent mixture. Computational results showed that the CNIBS/R-K model had more advantages than other models.

Catalytic Pyrolysis of Waste Plastic Mixture

Science.gov (United States)

Sembiring, Ferdianta; Wahyu Purnomo, Chandra; Purwono, Suryo

2018-03-01

Inorganic waste especially plastics still become a major problem in many places. Low biodegradability of this materials causes the effort in recycling become very difficult. Most of the municipal solid waste (MSW) recycling facilities in developing country only use composting method to recover the organic fraction of the waste, while the inorganic fraction is still untreated. By pyrolysis, plastic waste can be treated to produce liquid fuels, flammable gas and chars. Reduction in volume and utilization of the liquid and gas as fuel are the major benefits of the process. By heat integration actually this process can become a self-sufficient system in terms of energy demand. However, the drawback of this process is usually due to the diverse type of plastic in the MSW creating low grade of liquid fuel and harmful gases. In this study, the mixture of plastics i.e. polypropylene (PP) and polyethylene terephthalate (PET) is treated using pyrolysis with catalyst in several operating temperature. PET is problematic to be treated using pyrolysis due to wax-like byproduct in liquid which may cause pipe clogging. The catalyst is the mixture of natural zeolite and bentonite which is able to handle PP and PET mixture feed to produce high grade liquid fuels in terms of calorific value and other fuel properties.

Structure and thermodynamics of molten salts

International Nuclear Information System (INIS)

Papatheodorou, G.N.

1983-01-01

This chapter investigates single-component molten salts and multicomponent salt mixtures. Molten salts provide an important testing ground for theories of liquids, solutions, and plasmas. Topics considered include molten salts as liquids (the pair potential, the radial distribution function, methods of characterization), single salts (structure, thermodynamic correlations), and salt mixtures (the thermodynamics of mixing; spectroscopy and structure). Neutron and X-ray scattering techniques are used to determine the structure of molten metal halide salts. The corresponding-states theory is used to obtain thermodynamic correlations on single salts. Structural information on salt mixtures is obtained by using vibrational (Raman) and electronic absorption spectroscopy. Charge-symmetrical systems and charge-unsymmetrical systems are used to examine the thermodynamics of salt mixtures

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

International Nuclear Information System (INIS)

Araki, Takeaki; Tanaka, Hajime

2008-01-01

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

(Liquid + liquid) equilibria for (water + 1-propanol or acetone + β-citronellol) at different temperatures

International Nuclear Information System (INIS)

Li, Hengde; Han, Yongtao; Huang, Cheng; Yang, Chufen

2015-01-01

Graphical abstract: (Liquid + liquid) equilibrium data for systems composed of β-citronellol and aqueous 1-propanol or acetone are presented. Distribution ratios of 1-propanol and acetone in the mixtures are examined. The effect of the temperature on the ternary (liquid + liquid) equilibria is evaluated and discussed. - Highlights: • Ternary (liquid + liquid) equilibria containing β-citronellol are presented. • Distribution ratios of 1-propanol and acetone in the mixtures are examined. • The effect on the temperature of the systems is evaluated and discussed. - Abstract: On this paper, experimental (liquid + liquid) equilibrium (LLE) results are presented for systems composed of β-citronellol and aqueous 1-propanol or acetone. To evaluate the phase separation properties of β-citronellol in aqueous mixtures, LLE values for the ternary systems (water + 1-propanol + β-citronellol) and (water + acetone + β-citronellol) were determined with a tie-line method at T = (283.15, 298.15, and 313.15 ± 0.02) K and atmospheric pressure. The reliability of the experimental tie-lines was verified by the Hand and Bachman equations. Ternary phase diagrams, distribution ratios of 1-propanol and acetone in the mixtures are shown. The effect of the temperature on the ternary (liquid + liquid) equilibria was examined and discussed. The experimental LLE values were satisfactorily correlated by extended UNIQUAC and modified UNIQUAC models

Status of thermophysical properties data for pure fluids and mixtures of cryogenic interest

International Nuclear Information System (INIS)

Haynes, W.M.; Hiza, M.J.; Kidney, A.J.; Olien, N.A.

1984-01-01

This chapter discusses the importance, availability, and deficiencies of the existing data bases for the thermophysical properties of cryogenic fluids, including mixtures, considering both scientific and engineering interests. The following types of phase equilibria are emphasized: liquid-vapor, solid-vapor, liquid-liquid (or liquid-liquid-vapor), and solid-liquid (or solid-liquid-vapor). The available thermophysical properties data for both pure fluids and mixtures are summarized. Specific recommendations are made for future experimental measurements. It is predicted that the major thrust of future studies of cryogenic fluids will involve mixtures. The fluids considered include those involved in cryogenic processing with melting temperatures below ambient

Molecular dynamics simulation for the test of calibrated OPLS-AA force field for binary liquid mixture of tri-iso-amyl phosphate and n-dodecane

Science.gov (United States)

Das, Arya; Ali, Sk. Musharaf

2018-02-01

Tri-isoamyl phosphate (TiAP) has been proposed to be an alternative for tri-butyl phosphate (TBP) in the Plutonium Uranium Extraction (PUREX) process. Recently, we have successfully calibrated and tested all-atom optimized potentials for liquid simulations using Mulliken partial charges for pure TiAP, TBP, and dodecane by performing molecular dynamics (MD) simulation. It is of immense importance to extend this potential for the various molecular properties of TiAP and TiAP/n-dodecane binary mixtures using MD simulation. Earlier, efforts were devoted to find out a suitable force field which can explain both structural and dynamical properties by empirical parameterization. Therefore, the present MD study reports the structural, dynamical, and thermodynamical properties with different mole fractions of TiAP-dodecane mixtures at the entire range of mole fraction of 0-1 employing our calibrated Mulliken embedded optimized potentials for liquid simulation (OPLS) force field. The calculated electric dipole moment of TiAP was seen to be almost unaffected by the TiAP concentration in the dodecane diluent. The calculated liquid densities of the TiAP-dodecane mixture are in good agreement with the experimental data. The mixture densities at different temperatures are also studied which was found to be reduced with temperature as expected. The plot of diffusivities for TiAP and dodecane against mole fraction in the binary mixture intersects at a composition in the range of 25%-30% of TiAP in dodecane, which is very much closer to the TBP/n-dodecane composition used in the PUREX process. The excess volume of mixing was found to be positive for the entire range of mole fraction and the excess enthalpy of mixing was shown to be endothermic for the TBP/n-dodecane mixture as well as TiAP/n-dodecane mixture as reported experimentally. The spatial pair correlation functions are evaluated between TiAP-TiAP and TiAP-dodecane molecules. Further, shear viscosity has been computed by

Molecular dynamics simulation for the test of calibrated OPLS-AA force field for binary liquid mixture of tri-iso-amyl phosphate and n-dodecane.

Science.gov (United States)

Das, Arya; Ali, Sk Musharaf

2018-02-21

Tri-isoamyl phosphate (TiAP) has been proposed to be an alternative for tri-butyl phosphate (TBP) in the Plutonium Uranium Extraction (PUREX) process. Recently, we have successfully calibrated and tested all-atom optimized potentials for liquid simulations using Mulliken partial charges for pure TiAP, TBP, and dodecane by performing molecular dynamics (MD) simulation. It is of immense importance to extend this potential for the various molecular properties of TiAP and TiAP/n-dodecane binary mixtures using MD simulation. Earlier, efforts were devoted to find out a suitable force field which can explain both structural and dynamical properties by empirical parameterization. Therefore, the present MD study reports the structural, dynamical, and thermodynamical properties with different mole fractions of TiAP-dodecane mixtures at the entire range of mole fraction of 0-1 employing our calibrated Mulliken embedded optimized potentials for liquid simulation (OPLS) force field. The calculated electric dipole moment of TiAP was seen to be almost unaffected by the TiAP concentration in the dodecane diluent. The calculated liquid densities of the TiAP-dodecane mixture are in good agreement with the experimental data. The mixture densities at different temperatures are also studied which was found to be reduced with temperature as expected. The plot of diffusivities for TiAP and dodecane against mole fraction in the binary mixture intersects at a composition in the range of 25%-30% of TiAP in dodecane, which is very much closer to the TBP/n-dodecane composition used in the PUREX process. The excess volume of mixing was found to be positive for the entire range of mole fraction and the excess enthalpy of mixing was shown to be endothermic for the TBP/n-dodecane mixture as well as TiAP/n-dodecane mixture as reported experimentally. The spatial pair correlation functions are evaluated between TiAP-TiAP and TiAP-dodecane molecules. Further, shear viscosity has been computed by

A critical test of bivelocity hydrodynamics for mixtures.

Science.gov (United States)

Brenner, Howard

2010-10-21

The present paper provides direct noncircumstantial evidence in support of the existence of a diffuse flux of volume j(v) in mixtures. As such, it supersedes an earlier paper [H. Brenner, J. Chem. Phys. 132, 054106 (2010)], which offered only indirect circumstantial evidence in this regard. Given the relationship of the diffuse volume flux to the fluid's volume velocity, this finding adds additional credibility to the theory of bivelocity hydrodynamics for both gaseous and liquid continua, wherein the term bivelocity refers to the independence of the fluid's respective mass and volume velocities. Explicitly, the present work provides a new and unexpected linkage between a pair of diffuse fluxes entering into bivelocity mixture theory, fluxes that were previously regarded as constitutively independent, except possibly for their coupling arising as a consequence of Onsager reciprocity. In particular, for the case of a binary mixture undergoing an isobaric, isothermal, external force-free, molecular diffusion process we establish by purely macroscopic arguments-while subsequently confirming by purely molecular arguments-the validity of the ansatz j(v)=(v(1)-v(2))j(1) relating the diffuse volume flux j(v) to the diffuse mass fluxes j(1)(=-j(2)) of the two species and, jointly, their partial specific volumes v(1),v(2). Confirmation of that relation is based upon the use of linear irreversible thermodynamic principles to embed this ansatz in a broader context, and to subsequently establish the accord thereof with Shchavaliev's solution of the multicomponent Boltzmann equation for dilute gases [M. Sh. Shchavaliev, Fluid Dyn. 9, 96 (1974)]. Moreover, because the terms v(1), v(2), and j(1) appearing on the right-hand side of the ansatz are all conventional continuum fluid-mechanical terms (with j(1) given, for example, by Fick's law for thermodynamically ideal solutions), parity requires that j(v) appearing on the left-hand side of that relation also be a continuum term

Effects of complex organic mixtures of coal liquid on cardiovascular function

International Nuclear Information System (INIS)

Springer, D.L.; Sasser, L.B.; Zangar, R.C.; Mahlum, D.D.

1986-01-01

The most common diseases in the US are those involving the cardiovascular system. Exposure to certain environmental chemicals and complex mixtures may be involved in some aspects of cardiovascular disease. They have previously reported that high-boiling coal liquids resulted in several affects related to the cardiovascular system of the rate when exposed via whole-body inhalation to the mixture. The most striking observation was a dose dependent elevation in arterial blood pressure for heavy distillate (HD) exposed rates compared to control animals at 2 weeks. They also noted an increase in heart rate and plasma and blood volume. Additional rats were evaluated 6 weeks after exposure, to determine whether these effects represented permanent changes in cardiovascular function, and the effects appeared to be reversible after this longer period. During the past year they have completed the assays of the studies initiated previously and have addressed some possible factors which could explain the effects that they observed. Electrolytes in plasma of rats exposed to the HD were analyzed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Plasma aldosterone and angiotensin were measured by radioimmunoassays, and plasma cholesterol, triglycerides, and high-density lipoprotein were evaluated with an Abbott VP bichromatic chemistry analyzer. In addition, a comparison of the blood pressure of control rats and rats fed a restricted diet were made, to determine if the anorexia which resulted from HD exposure could be responsible for the changes they observed in cardiovascular function

Thermodynamics of binary mixtures of N-methyl-2-pyrrolidinone and ketone. Experimental results and modelling of the (solid + liquid) equilibrium and the (vapour + liquid) equilibrium. The modified UNIFAC (Do) model characterization

International Nuclear Information System (INIS)

Domanska, Urszula; Lachwa, Joanna

2005-01-01

The (solid + liquid) equilibrium (SLE) of eight binary systems containing N-methyl-2-pyrrolidinone (NMP) with (2-propanone, or 2-butanone, or 2-pentanone, or 3-pentanone, or cyclopentanone, or 2-hexanone, or 4-methyl-2-pentanone, or 3-heptanone) were carried out by using a dynamic method from T = 200 K to the melting point of the NMP. The isothermal (vapour + liquid) equilibrium data (VLE) have been measured for three binary mixtures of NMP with 2-propanone, 3-pentanone and 2-hexanone at pressure range from p = 0 kPa to p = 115 kPa. Data were obtained at the temperature T = 333.15 K for the first system and at T = 373.15 K for the second two systems. The experimental results of SLE have been correlated using the binary parameters Wilson, UNIQUAC ASM and two modified NRTL equations. The root-mean-square deviations of the solubility temperatures for all the calculated values vary from (0.32 K to 0.68 K) and depend on the particular equation used. The data of VLE were correlated with one to three parameters in the Redlich-Kister expansion. Binary mixtures of NMP with (2-propanone, or 2-butanone, or 2-pentanone, or 3-pentanone, or cyclopentanone, or 2-hexanone, or 4-methyl-2-pentanone, or 3-heptanone) have been investigated in the framework of the modified UNIFAC (Do) model. The reported new interaction parameters for NMP-group (c-CONCH 3 ) and carbonyl group ( C=O) let the model consistently described a set of thermodynamic properties, including (solid + liquid) equilibrium (vapour + liquid) equilibrium, excess Gibbs energy and molar excess enthalpies of mixing. Our experimental and literature data of binary mixtures containing NMP and ketones were compared with the results of prediction with the modified UNIFAC (Do) model

The effects of LMWOAs on biodegradation of multi-component PAHs in aqueous solution using dual-wavelength fluorimetry

International Nuclear Information System (INIS)

Wei Xingyuan; Sang Lingzi; Chen Jianing; Zhu Yaxian; Zhang Yong

2009-01-01

Biodegradation of dissolved fluorene (Flu), phenanthrene (Ph) and pyrene (Py), three polycyclic aromatic hydrocarbons (PAHs), singly or as a mixture of the three, by two bacterial strains, MEBIC 5140 (Mycobacterium flavescens) and MEBIC 5141 (Mycobacterium scrofulaceum), as well as the effects of low molecular weight organic acids (LMWOAs), e.g. malic acid, citric acid and butyric acid on biodegradation of the three PAHs in mineral salts medium aqueous solution were investigated using a newly established dual-wavelength fluorimetric method. The results showed that biodegradation processes can be monitored simultaneously, quickly and simply by dual-wavelength fluorimetry. Both co-metabolism and inhibitory effects were found during the biodegradation of the three PAHs by MEBIC 5140 and MEBIC 5141. Positive effects of butyric acid and negative effects of citric acid on biodegradation of the three PAHs in a mixture were observed. - Biodegradation processes of dissolved multi-component PAHs in a mixture and effects of LMWOAs were investigated using a dual-wavelength fluorimetry.

Applications of the Simple Multi-Fluid Model to Correlations of the Vapor-Liquid Equilibrium of Refrigerant Mixtures Containing Carbon Dioxide

Science.gov (United States)

Akasaka, Ryo

This study presents a simple multi-fluid model for Helmholtz energy equations of state. The model contains only three parameters, whereas rigorous multi-fluid models developed for several industrially important mixtures usually have more than 10 parameters and coefficients. Therefore, the model can be applied to mixtures where experimental data is limited. Vapor-liquid equilibrium (VLE) of the following seven mixtures have been successfully correlated with the model: CO2 + difluoromethane (R-32), CO2 + trifluoromethane (R-23), CO2 + fluoromethane (R-41), CO2 + 1,1,1,2- tetrafluoroethane (R-134a), CO2 + pentafluoroethane (R-125), CO2 + 1,1-difluoroethane (R-152a), and CO2 + dimethyl ether (DME). The best currently available equations of state for the pure refrigerants were used for the correlations. For all mixtures, average deviations in calculated bubble-point pressures from experimental values are within 2%. The simple multi-fluid model will be helpful for design and simulations of heat pumps and refrigeration systems using the mixtures as working fluid.

Ionic Liquid-Catalyzed Green Protocol for Multi-Component Synthesis of Dihydropyrano[2,3-c]pyrazoles as Potential Anticancer Scaffolds

Directory of Open Access Journals (Sweden)

Urja D. Nimbalkar

2017-09-01

Full Text Available A series of 6-amino-4-substituted-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles 5a–j were synthesized via one-pot, four-component condensation reactions of aryl aldehydes 1a–j, propanedinitrile (2, hydrazine hydrate (3 and ethyl acetoacetate (4 under solvent-free conditions. We report herein the use of the Brønsted acid ionic liquid (BAIL triethylammonium hydrogen sulphate [Et3NH][HSO4] as catalyst for this multi-component synthesis. Compared with the available reaction methodology, this new method has consistent advantages, including excellent yields, a short reaction time, mild reaction conditions and catalyst reusability. Selected synthesized derivatives were evaluated for in vitro anticancer activity against four human cancer cell lines viz. melanoma cancer cell line (SK-MEL-2, breast cancer cell line(MDA-MB-231, leukemia cancer cell line (K-562 and cervical cancer cell line (HeLa. Compounds 5b, 5d, 5g, 5h and 5j exhibited promising anticancer activity against all selected human cancer cell lines, except HeLa. Molecular docking studies also confirmed 5b and 5d as good lead molecules. An in silico ADMET study of the synthesized anticancer agents indicated good oral drug-like behavior and non-toxic nature.

Multicomponent density functional theory embedding formulation

Energy Technology Data Exchange (ETDEWEB)

Culpitt, Tanner; Brorsen, Kurt R.; Pak, Michael V.; Hammes-Schiffer, Sharon, E-mail: shs3@illinois.edu [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Ave, Urbana, Illinois 61801 (United States)

2016-07-28

Multicomponent density functional theory (DFT) methods have been developed to treat two types of particles, such as electrons and nuclei, quantum mechanically at the same level. In the nuclear-electronic orbital (NEO) approach, all electrons and select nuclei, typically key protons, are treated quantum mechanically. For multicomponent DFT methods developed within the NEO framework, electron-proton correlation functionals based on explicitly correlated wavefunctions have been designed and used in conjunction with well-established electronic exchange-correlation functionals. Herein a general theory for multicomponent embedded DFT is developed to enable the accurate treatment of larger systems. In the general theory, the total electronic density is separated into two subsystem densities, denoted as regular and special, and different electron-proton correlation functionals are used for these two electronic densities. In the specific implementation, the special electron density is defined in terms of spatially localized Kohn-Sham electronic orbitals, and electron-proton correlation is included only for the special electron density. The electron-proton correlation functional depends on only the special electron density and the proton density, whereas the electronic exchange-correlation functional depends on the total electronic density. This scheme includes the essential electron-proton correlation, which is a relatively local effect, as well as the electronic exchange-correlation for the entire system. This multicomponent DFT-in-DFT embedding theory is applied to the HCN and FHF{sup −} molecules in conjunction with two different electron-proton correlation functionals and three different electronic exchange-correlation functionals. The results illustrate that this approach provides qualitatively accurate nuclear densities in a computationally tractable manner. The general theory is also easily extended to other types of partitioning schemes for multicomponent systems.

Nonideal mixing in multicomponent lipid/detergent systems

International Nuclear Information System (INIS)

Tsamaloukas, Alekos; Szadkowska, Halina; Heerklotz, Heiko

2006-01-01

A detailed understanding of the mixing properties of membranes to which detergents are added is mandatory for improving the application and interpretation of detergent based protein or lipid extraction assays. For Triton X-100 (TX-100), a nonionic detergent frequently used in the process of solubilizing and purifying membrane proteins and lipids, we present here a detailed study of the mixing properties of binary and ternary lipid mixtures by means of high-sensitivity isothermal titration calorimetry (ITC). To this end the partitioning thermodynamics of TX-100 molecules from the aqueous phase to lipid bilayers composed of various mixtures of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), egg-sphingomyelin (SM), and cholesterol (cho) are characterized. Composition-dependent partition coefficients K are analysed within the frame of a thermodynamic model developed to describe nonideal mixing in multicomponent lipid/detergent systems. The results imply that POPC, fluid SM, and TX-100 mix almost ideally (nonideality parameters ρ α/β SM/cho ≤-6RT) and unfavourable PC/cho interactions (ρ PC/cho = 2RT) may under certain conditions cause POPC/TX-100-enriched domains to segregate from SM/cho-enriched ones. TX-100/cho contacts are unfavourable (ρ cho/TX = 4RT), so the system tends to avoid them. That means, addition of TX-100 promotes the separation of SM/cho-rich from PC/TX-100-rich domains. It appears that cho/detergent interactions are crucial governing the abundance and composition of detergent-resistant membrane patches

Potential theory of adsorption for associating mixtures: possibilities and limitations

DEFF Research Database (Denmark)

Bjørner, Martin Gamel; Shapiro, Alexander; Kontogeorgis, Georgios

2013-01-01

The applicability of the Multicomponent Potential Theory of Adsorption (MPTA) for prediction of the adsorption equilibrium of several associating binary mixtures on different industrial adsorbents is investigated. In the MPTA the adsorbates are considered to be distributed fluids subject...... to describe the solid-fluid interactions. The potential is extended to include adsorbate-absorbent specific capacities rather than an adsorbent specific capacity. Correlations of pure component isotherms are generally excellent with individual capacities, although adsorption on silicas at different...... temperatures still poses a challenge. The quality of the correlations is usually independent on the applied EoS. Predictions for binary mixtures indicate that the MPTA+SRK is superior when adsorption occurs on non-polar or slightly polar adsorbents, while MPTA+CPA performs better for polar adsorbents, or when...

Multiphase flow modeling of molten material-vapor-liquid mixtures in thermal nonequilibrium

International Nuclear Information System (INIS)

Park, Ik Kyu; Park, Goon Cherl; Bang, Kwang Hyun

2000-01-01

This paper presents a numerical model of multiphase flow of the mixtures of molten material-liquid-vapor, particularly in thermal nonequilibrium. It is a two-dimensional, transient, three-fluid model in Eulerian coordinates. The equations are solved numerically using the finite difference method that implicitly couples the rates of phase changes, momentum, and energy exchange to determine the pressure, density, and velocity fields. To examine the model's ability to predict an experimental data, calculations have been performed for tests of pouring hot particles and molten material into a water pool. The predictions show good agreement with the experimental data. It appears, however, that the interfacial heat transfer and breakup of molten material need improved models that can be applied to such high temperature, high pressure, multiphase flow conditions

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-06-24

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

BUFFER CAPACITY IN HETEROGENEOUS MULTICOMPONENT SYSTEMS. REVIEW

Directory of Open Access Journals (Sweden)

Oxana Spinu

2015-12-01

Full Text Available The quantitative basis of the theory of buffer properties for two-phase acid-base buffer systems and for multicomponent heterogeneous systems has been derived. The analytical equations with respect to all components for diverse multicomponent systems were deduced. It has been established, that the buffer capacities of components are mutually proportional.

Equivalence of two models in single-phase multicomponent flow simulations

KAUST Repository

Wu, Yuanqing

2016-02-28

In this work, two models to simulate the single-phase multicomponent flow in reservoirs are introduced: single-phase multicomponent flow model and two-phase compositional flow model. Because the single-phase multicomponent flow is a special case of the two-phase compositional flow, the two-phase compositional flow model can also simulate the case. We compare and analyze the two models when simulating the single-phase multicomponent flow, and then demonstrate the equivalence of the two models mathematically. An experiment is also carried out to verify the equivalence of the two models.

Equivalence of two models in single-phase multicomponent flow simulations

KAUST Repository

Wu, Yuanqing; Sun, Shuyu

2016-01-01

In this work, two models to simulate the single-phase multicomponent flow in reservoirs are introduced: single-phase multicomponent flow model and two-phase compositional flow model. Because the single-phase multicomponent flow is a special case of the two-phase compositional flow, the two-phase compositional flow model can also simulate the case. We compare and analyze the two models when simulating the single-phase multicomponent flow, and then demonstrate the equivalence of the two models mathematically. An experiment is also carried out to verify the equivalence of the two models.

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

Energy Technology Data Exchange (ETDEWEB)

Alvarez, Victor H. [School of Chemical Engineering, State University of Campinas (UNICAMP), P.O. Box 6066, 13083-970 Campinas-SP (Brazil); Chemical Engineering Department, ETSE, University of Santiago de Compostela (USC), P.O. Box 15782, Santiago de Compostela (Spain); Mattedi, Silvana [Chemical Engineering Department, Polytechnic School, Federal University of Bahia (UFBA), 40210-630 Salvador-BA (Brazil); Martin-Pastor, Manuel [Unidade de Resonancia Magnetica, RIAIDT, edif. CACTUS, University of Santiago de Compostela (USC), P.O. Box 15706, Santiago de Compostela (Spain); Aznar, Martin [School of Chemical Engineering, State University of Campinas (UNICAMP), P.O. Box 6066, 13083-970 Campinas-SP (Brazil); Iglesias, Miguel, E-mail: miguel.iglesias@usc.es [Chemical Engineering Department, ETSE, University of Santiago de Compostela (USC), P.O. Box 15782, Santiago de Compostela (Spain)

2011-07-15

Research highlights: > This paper reports the density and speed of sound data of binary mixtures {l_brace}2-hydroxy ethylammonium acetate + (water, or methanol, or ethanol){r_brace} measured between the temperatures (298.15 and 313.15) K at atmospheric pressure. > The aggregation, dynamic behavior, and hydrogen-bond network were studied using thermo-acoustic, X-ray, and NMR techniques. > The Peng-Robinson equation of state, coupled with the Wong-Sandler mixing rule using the COSMO-SAC model predicted the density of the solutions with relative mean deviations below than 3.0%. - Abstract: In this work, density and speed of sound data of binary mixtures of an ionic liquid consisting of {l_brace}2-hydroxy ethylammonium acetate (2-HEAA) + (water, methanol, or ethanol){r_brace} have been measured throughout the entire concentration range, from the temperature of (288.15 to 323.15) K at atmospheric pressure. The excess molar volumes, variations of the isentropic compressibility, the apparent molar volume, isentropic apparent molar compressibility, and thermal expansion coefficient were calculated from the experimental data. The excess molar volumes were negative throughout the whole composition range. Compressibility data in combination with low angle X-ray scattering and NMR measurements proved that the presence of micelles formed due to ion pair interaction above a critical concentration of the ionic liquid in the mixtures. The Peng-Robinson equation of state coupled with the Wong-Sandler mixing rule and COSMO-SAC model was used to predict densities and the calculated deviations were lower than 3%, for binary mixtures in all composition range.

Bonding and structure in dense multi-component molecular mixtures.

Science.gov (United States)

Meyer, Edmund R; Ticknor, Christopher; Bethkenhagen, Mandy; Hamel, Sebastien; Redmer, Ronald; Kress, Joel D; Collins, Lee A

2015-10-28

We have performed finite-temperature density functional theory molecular dynamics simulations on dense methane, ammonia, and water mixtures (CH4:NH3:H2O) for various compositions and temperatures (2000 K ≤ T ≤ 10,000 K) that span a set of possible conditions in the interiors of ice-giant exoplanets. The equation-of-state, pair distribution functions, and bond autocorrelation functions (BACF) were used to probe the structure and dynamics of these complex fluids. In particular, an improvement to the choice of the cutoff in the BACF was developed that allowed analysis refinements for density and temperature effects. We note the relative changes in the nature of these systems engendered by variations in the concentration ratios. A basic tenet emerges from all these comparisons that varying the relative amounts of the three heavy components (C,N,O) can effect considerable changes in the nature of the fluid and may in turn have ramifications for the structure and composition of various planetary layers.

Microstructure and hydrogen bonding in water-acetonitrile mixtures.

Science.gov (United States)

Mountain, Raymond D

2010-12-16

The connection of hydrogen bonding between water and acetonitrile in determining the microheterogeneity of the liquid mixture is examined using NPT molecular dynamics simulations. Mixtures for six, rigid, three-site models for acetonitrile and one water model (SPC/E) were simulated to determine the amount of water-acetonitrile hydrogen bonding. Only one of the six acetonitrile models (TraPPE-UA) was able to reproduce both the liquid density and the experimental estimates of hydrogen bonding derived from Raman scattering of the CN stretch band or from NMR quadrupole relaxation measurements. A simple modification of the acetonitrile model parameters for the models that provided poor estimates produced hydrogen-bonding results consistent with experiments for two of the models. Of these, only one of the modified models also accurately determined the density of the mixtures. The self-diffusion coefficient of liquid acetonitrile provided a final winnowing of the modified model and the successful, unmodified model. The unmodified model is provisionally recommended for simulations of water-acetonitrile mixtures.

Chiral domain formation from the mixture of achiral rod-like liquid crystal and tri boomerang-shaped molecule

Science.gov (United States)

Lee, Ji-Hoon; Yoon, Tae-Hoon

2013-08-01

Spontaneous formation of chiral domains such as a helical filament and a bent-broom texture was observed from the mixture of a rod-like liquid crystal octylcyano-biphenyl (8CB) and a tri boomerang-shaped 2,4,6-triphenoxy-1,3,5-triazine (triphenoxy) molecule. Although the constituent molecules were achiral, their mixture showed the chiral domains with the equal fraction of the opposite handedness. No tilt of 8CB molecules in the smectic layer was observed, implying the chirality is not due to the polar packing and tilt of the molecules. In addition, the splay and bend elastic constant of 8CB was decreased after doping triphenoxy. A structural conformation of triphenoxy and an orientational coupling between 8CB and triphenoxy are considered to be related to the chiral domain formation.

Specificity Switching Pathways in Thermal and Mass Evaporation of Multicomponent Hydrocarbon Droplets: A Mesoscopic Observation.

Science.gov (United States)

Nasiri, Rasoul; Luo, Kai H

2017-07-10

For well over one century, the Hertz-Knudsen equation has established the relationship between thermal - mass transfer coefficients through a liquid - vapour interface and evaporation rate. These coefficients, however, have been often separately estimated for one-component equilibrium systems and their simultaneous influences on evaporation rate of fuel droplets in multicomponent systems have yet to be investigated at the atomic level. Here we first apply atomistic simulation techniques and quantum/statistical mechanics methods to understand how thermal and mass evaporation effects are controlled kinetically/thermodynamically. We then present a new development of a hybrid method of quantum transition state theory/improved kinetic gas theory, for multicomponent hydrocarbon systems to investigate how concerted-distinct conformational changes of hydrocarbons at the interface affect the evaporation rate. The results of this work provide an important physical concept in fundamental understanding of atomistic pathways in topological interface transitions of chain molecules, resolving an open problem in kinetics of fuel droplets evaporation.

Integrating qualitative and quantitative characterization of traditional Chinese medicine injection by high-performance liquid chromatography with diode array detection and tandem mass spectrometry.

Science.gov (United States)

Xie, Yuan-yuan; Xiao, Xue; Luo, Juan-min; Fu, Chan; Wang, Qiao-wei; Wang, Yi-ming; Liang, Qiong-lin; Luo, Guo-an

2014-06-01

The present study aims to describe and exemplify an integrated strategy of the combination of qualitative and quantitative characterization of a multicomponent mixture for the quality control of traditional Chinese medicine injections with the example of Danhong injection (DHI). The standardized chemical profile of DHI has been established based on liquid chromatography with diode array detection. High-performance liquid chromatography coupled with time-of-flight mass spectrometry and high-performance liquid chromatography with electrospray multistage tandem ion-trap mass spectrometry have been developed to identify the major constituents in DHI. The structures of 26 compounds including nucleotides, phenolic acids, and flavonoid glycosides were identified or tentatively characterized. Meanwhile, the simultaneous determination of seven marker constituents, including uridine, adenosine, danshensu, protocatechuic aldehyde, p-coumaric acid, rosmarinic acid, and salvianolic acid B, in DHI was performed by multiwavelength detection based on high-performance liquid chromatography with diode array detection. The integrated qualitative and quantitative characterization strategy provided an effective and reliable pattern for the comprehensive and systematic characterization of the complex traditional Chinese medicine system. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Theoretical Rocket Performance of Liquid Methane with Several Fluorine-Oxygen Mixtures Assuming Frozen Composition

Science.gov (United States)

Gordon, Sanford; Kastner, Michael E

1958-01-01

Theoretical rocket performance for frozen composition during expansion was calculated for liquid methane with several fluorine-oxygen mixtures for a range of pressure ratios and oxidant-fuel ratios. The parameters included are specific impulse, combustion-chamber temperature, nozzle-exit temperature molecular weight, characteristic velocity, coefficient of thrust, ratio of nozzle-exit area to throat area, specific heat at constant pressure, isentropic exponent, viscosity, and thermal conductivity. The maximum calculated value of specific impulse for a chamber pressure of 600 pounds per square inch absolute (40.827atm) and an exit pressure of 1 atmosphere is 315.3 for 79.67 percent fluorine in the oxidant.

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

Thermodynamic properties and phase equilibria of associating mixtures cannot often be satisfactorily modelled using conventional models such as cubic equations of state. CPA (cubic-plus-association) is an equation of state (EoS), which combines the SRK EoS with the association term of SAFT. For non......-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...... thermodynamic models especially those combining cubic EoS with local composition activity coefficient models are included. (C) 2007 Elsevier B.V. All rights reserved....

Empirical equation of state of the products of the detonation of a liquid explosive based on mixtures of tetranitromethane and nitrobenzene of various compositions

International Nuclear Information System (INIS)

Adigamova, T.A.; Davydov, N.B.

2012-01-01

The equation of state of the products of the detonation of liquid explosives has been derived by theoretical analysis and calculations. The dependence of the detonation rate on the oxygen balance has been obtained using the existing data on the physicomechanical and detonation properties of liquid explosive mixtures. Calculation dependences of the density on the weight content of nitrobenzene have been obtained [ru

in Binary Liquid Mixtures of Ethyl benzoate

Directory of Open Access Journals (Sweden)

Shaik Babu

2012-01-01

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

Contact angle determination in multicomponent lattice Boltzmann simultations

NARCIS (Netherlands)

Schmieschek, S.M.P.; Harting, J.D.R.

2011-01-01

Droplets on hydrophobic surfaces are ubiquitous in microfluidic applications and there exists a number of commonly used multicomponent and multiphase lattice Boltzmann schemes to study such systems. In this paper we focus on a popular implementation of a multicomponent model as introduced by Shan

REFRIGERANT/LUBRICANT MIXTURES: PROBLEMS OF APPLICATION AND PROPERTY RESEARCH

Directory of Open Access Journals (Sweden)

Yu. Semenyuk

2013-10-01

Full Text Available The results and generalizations of thermophysical property research for the refrigerant/lubricant mixtures are summarized. The methodological aspects of the experimental studies of the thermal properties of real working media for vapor compression refrigeration machines and the general principles of the thermodynamic properties simulation for such solutions are analyzed. It is shown that the admixtures of compressor oil in the refrigerant make the efficiency parameters of compressor systems much lower. The question of a selective solubility of the multicomponent refrigerants in compressor oils is discussed.

Recent developments in biocatalysis in multiphasic ionic liquid reaction systems.

Science.gov (United States)

Meyer, Lars-Erik; von Langermann, Jan; Kragl, Udo

2018-06-01

Ionic liquids are well known and frequently used 'designer solvents' for biocatalytic reactions. This review highlights recent achievements in the field of multiphasic ionic liquid-based reaction concepts. It covers classical biphasic systems including supported ionic liquid phases, thermo-regulated multi-component solvent systems (TMS) and polymerized ionic liquids. These powerful concepts combine unique reaction conditions with a high potential for future applications on a laboratory and industrial scale. The presence of a multiphasic system simplifies downstream processing due to the distribution of the catalyst and reactants in different phases.

Development of dispersive liquid-liquid microextraction technique using ternary solvents mixture followed by heating for the rapid and sensitive analysis of phthalate esters and di(2-ethylhexyl) adipate.

Science.gov (United States)

Farajzadeh, Mir Ali; Khoshmaram, Leila

2015-01-30

In this study, for the first time, a dispersive liquid-liquid microextraction technique using a ternary solvent mixture is reported. In order to extract five phthalate esters and di(2-ethylhexyl) adipate with different polarities from aqueous samples, a simplex centroid experimental design method was used to select an optimal mixture of ternary solvents prior to gas chromatographyflame ionization detection. In this work, dimethyl formamide as a disperser solvent containing dichloromethane, chloroform, and carbon tetrachloride as a ternary extraction solvent mixture is injected into sample solution and a cloudy solution is formed. After centrifuging, 250μL of the obtained sedimented phase was transferred into another tube and 5μL DMF was added to it. Then, the tube was heated in a water bath at 75°C for 5min in order to evaporate the main portion of the extraction solvents. Finally, 2μL of the remained phase is injected into the separation system. Under the optimum extraction conditions, the method shows wide linear ranges and low limits of detection and quantification between 0.03-0.15 and 0.09-0.55μgL(-1), respectively. Enrichment factors and extraction recoveries are in the ranges of 980-4500 and 20-90%, respectively. The method is successfully applied in the determination of the target analytes in mineral water, soda, lemon juice, vinegar, dough, and yogurt packed in plastic packages. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

Suthar, Shyam Sunder; Purohit, Suresh

2018-05-01

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

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

Directory of Open Access Journals (Sweden)

Sujata S. Patil

2014-12-01

Full Text Available Densities and viscosities for the four binary liquid mixtures of methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate with hexane-1-ol at temperatures 303.15 and 313.15 K and at atmospheric pressure were measured over the entire composition range. These values were used to calculate excess molar volumes and deviation in viscosities which were fitted to Redlich–Kister polynomial equation. Recently proposed Jouyban Acree model was also used to correlate the experimental values of density and viscosity. The mixture viscosities were correlated by several semi-empirical approaches like Hind, Choudhary–Katti, Grunberg–Nissan, Tamura and Kurata, McAllister three and four body model equations. A graphical representation of excess molar volumes and deviation in isentropic compressibility shows positive nature whereas deviation in viscosity shows negative nature at both temperatures for all four binary liquid mixtures. Positive values of excess molar volumes show that volume expansion is taking place causing rupture of H-bonds in self associated alcohols. The results were discussed in terms of molecular interactions prevailing in the mixtures.

Comparative study of three modified numerical spectrophotometric methods: An application on pharmaceutical ternary mixture of aspirin, atorvastatin and clopedogrel

Science.gov (United States)

Issa, Mahmoud Mohamed; Nejem, R.'afat Mahmoud; Shanab, Alaa Abu; Hegazy, Nahed Diab; Stefan-van Staden, Raluca-Ioana

2014-07-01

Three novel numerical methods were developed for the spectrophotometric multi-component analysis of capsules and synthetic mixtures of aspirin, atorvastatin and clopedogrel without any chemical separation. The subtraction method is based on the relationship between the difference in absorbance at four wavelengths and corresponding concentration of analyte. In this method, the linear determination ranges were 0.8-40 μg mL-1 aspirin, 0.8-30 μg mL-1 atorvastatin and 0.5-30 μg mL-1 clopedogrel. In the quotient method, 0.8-40 μg mL-1 aspirin, 0.8-30 μg mL-1 atorvastatin and 1.0-30 μg mL-1 clopedogrel were determine from spectral data at the wavelength pairs that show the same ratio of absorbance for other two species. Standard addition method was used for resolving ternary mixture of 1.0-40 μg mL-1 aspirin, 0.8-30 μg mL-1 atorvastatin and 2.0-30 μg mL-1 clopedogrel. The proposed methods were validated. The reproducibility and repeatability were found satisfactory which evidence was by low values of relative standard deviation (atorvastatin and clopedogrel in capsule dosage forms and results were in good concordance with alternative liquid chromatography.

Micro-/nanostructured multicomponent molecular materials: design, assembly, and functionality.

Science.gov (United States)

Yan, Dongpeng

2015-03-23

Molecule-based micro-/nanomaterials have attracted considerable attention because their properties can vary greatly from the corresponding macro-sized bulk systems. Recently, the construction of multicomponent molecular solids based on crystal engineering principles has emerged as a promising alternative way to develop micro-/nanomaterials. Unlike single-component materials, the resulting multicomponent systems offer the advantages of tunable composition, and adjustable molecular arrangement, and intermolecular interactions within their solid states. The study of these materials also supplies insight into how the crystal structure, molecular components, and micro-/nanoscale effects can influence the performance of molecular materials. In this review, we describe recent advances and current directions in the assembly and applications of crystalline multicomponent micro-/nanostructures. Firstly, the design strategies for multicomponent systems based on molecular recognition and crystal engineering principles are introduced. Attention is then focused on the methods of fabrication of low-dimensional multicomponent micro-/nanostructures. Their new applications are also outlined. Finally, we briefly discuss perspectives for the further development of these molecular crystalline micro-/nanomaterials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Computing bubble-points of CO

NARCIS (Netherlands)

Ramdin, M.; Balaji, S.P.; Vicent Luna, J.M.; Torres-Knoop, A; Chen, Q.; Dubbeldam, D.; Calero, S; de Loos, T.W.; Vlugt, T.J.H.

2016-01-01

Computing bubble-points of multicomponent mixtures using Monte Carlo simulations is a non-trivial task. A new method is used to compute gas compositions from a known temperature, bubble-point pressure, and liquid composition. Monte Carlo simulations are used to calculate the bubble-points of

Manufacturing cycle for pure neon-helium mixture production

International Nuclear Information System (INIS)

Batrakov, B.P.; Kravchenko, V.A.

1980-01-01

The manufacturing cycle for pure neon-helium mixture production with JA-300 nitrogen air distributing device has been developed. Gas mixture containing 2-3% of neon-helium mixture (the rest is mainly nitrogen 96-97%) is selected out of the cover of the JA-300 column condensator and enters the deflegmator under the 2.3-2.5 atm. pressure. The diflegmator presents a heat exchange apparatus in which at 78 K liquid nitrogen the condensation of nitrogen from the mixture of gases entering from the JA-300 column takes place. The enriched gas mixture containing 65-70% of neon-helium mixture and 30-35% of nitrogen goes out from the deflegmator. This enriched neon-helium mixture enters the gasgoeder for impure (65-70%) neon-helium mixture. Full cleaning of-neon helium mixture of nitrogen is performed by means of an adsorber. As adsorbent an activated coal has been used. Adsorption occurs at the 78 K temperature of liquid nitrogen and pressure P=0.1 atm. As activated coal cooled down to nitrogen temperature adsorbs nitrogen better than neon and helium, the nitrogen from the mixture is completely adsorbed. Pure neon-helium mixture from the adsorber comes into a separate gasgolder. In one campaign the cycle allows obtaining 2 m 3 of the mixture. The mixture contains 0.14% of nitrogen, 0.01% of oxygen and 0.06% of hydrogen

Thermodynamic parameters for mixtures of quartz under shock wave loading in views of the equilibrium model

International Nuclear Information System (INIS)

Maevskii, K. K.; Kinelovskii, S. A.

2015-01-01

The numerical results of modeling of shock wave loading of mixtures with the SiO 2 component are presented. The TEC (thermodynamic equilibrium component) model is employed to describe the behavior of solid and porous multicomponent mixtures and alloys under shock wave loading. State equations of a Mie–Grüneisen type are used to describe the behavior of condensed phases, taking into account the temperature dependence of the Grüneisen coefficient, gas in pores is one of the components of the environment. The model is based on the assumption that all components of the mixture under shock-wave loading are in thermodynamic equilibrium. The calculation results are compared with the experimental data derived by various authors. The behavior of the mixture containing components with a phase transition under high dynamic loads is described

Seismic reservoir characterization: how can multicomponent data help?

International Nuclear Information System (INIS)

Li, Xiang-Yang; Zhang, Yong-Gang

2011-01-01

This paper discusses the concepts of multicomponent seismology and how it can be applied to characterize hydrocarbon reservoirs, illustrated using a 3D three-component real-data example from southwest China. Hydrocarbon reservoirs formed from subtle lithological changes, such as stratigraphic traps, may be delineated from changes in P- and S-wave velocities and impedances, whilst hydrocarbon reservoirs containing aligned fractures are anisotropic. Examination of the resultant split shear waves can give us a better definition of their internal structures. Furthermore, frequency-dependent variations in seismic attributes derived from multicomponent data can provide us with vital information about fluid type and distribution. Current practice and various examples have demonstrated the undoubted potential of multicomponent seismic in reservoir characterization. Despite all this, there are still substantial challenges ahead. In particular, the improvement and interpretation of converted-wave imaging are major hurdles that need to be overcome before multicomponent seismic becomes a mainstream technology

Seismic reservoir characterization: how can multicomponent data help?

Science.gov (United States)

Li, Xiang-Yang; Zhang, Yong-Gang

2011-06-01

This paper discusses the concepts of multicomponent seismology and how it can be applied to characterize hydrocarbon reservoirs, illustrated using a 3D three-component real-data example from southwest China. Hydrocarbon reservoirs formed from subtle lithological changes, such as stratigraphic traps, may be delineated from changes in P- and S-wave velocities and impedances, whilst hydrocarbon reservoirs containing aligned fractures are anisotropic. Examination of the resultant split shear waves can give us a better definition of their internal structures. Furthermore, frequency-dependent variations in seismic attributes derived from multicomponent data can provide us with vital information about fluid type and distribution. Current practice and various examples have demonstrated the undoubted potential of multicomponent seismic in reservoir characterization. Despite all this, there are still substantial challenges ahead. In particular, the improvement and interpretation of converted-wave imaging are major hurdles that need to be overcome before multicomponent seismic becomes a mainstream technology.

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

DEFF Research Database (Denmark)

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

2011-01-01

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

Thermophysical properties of biodiesel and related systems: (Liquid + liquid) equilibrium data for Jatropha curcas biodiesel

International Nuclear Information System (INIS)

Silva, Juliana R.F.; Mazutti, Marcio A.; Voll, Fernando A.P.; Cardozo-Filho, Lúcio; Corazza, Marcos L.; Lanza, Marcelo; Priamo, Wagner L.; Vladimir Oliveira, J.

2013-01-01

Highlights: ► (Liquid + liquid) equilibrium data for multicomponent Jatropha curcas FAME and FAEE. ► Tie-lines, solubility curves (binodal curves) with low deviations from mass balance. ► Experimental data correlated with the UNIQUAC model. -- Abstract: Reported in this study are (liquid + liquid) equilibrium data for binary, ternary, and quaternary systems formed by fatty acid methyl esters (FAME) and fatty acid ethyl esters (FAEE) of Jatropha curcas oil, water, glycerol, methanol, and ethanol at temperatures of (303.15, 318.15, and 333.15) K. In general, all the systems investigated resulted in good agreement between phase compositions of crunodes of tie-lines, solubility curves (binodal curves) and overall compositions, hence indicating low deviations from mass balance. Experimental results were correlated with the UNIQUAC model, showing low deviations among experimental and calculated values

(Vapour + liquid) equilibria for the binary mixtures (1-propanol + dibromomethane, or + bromochloromethane, or + 1,2-dichloroethane or + 1-bromo-2-chloroethane) at T = 313.15 K

International Nuclear Information System (INIS)

Gil-Hernandez, V.; Garcia-Gimenez, P.; Otin, S.; Artal, M.; Velasco, I.

2005-01-01

Isothermal (vapour + liquid) equilibria (VLE) at 313.15 K have been measured for liquid 1-propanol + dibromomethane, or + bromochloromethane or + 1,2-dichloroethane or + 1-bromo-2-chloroethane mixtures. The VLE data were reduced using the Redlich-Kister equation taking into consideration the vapour phase imperfection in terms of the 2nd molar virial coefficients. The excess molar Gibbs free energies of all the studied mixtures are positive and ranging from 794 J·mol -1 for (1-propanol + bromochloromethane) and 1052 J·mol -1 for (1-propanol + 1-bromo-2-chloroethane), at x = 0.5. The experimental results are compared with modified UNIFAC predictions

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 ...

Challenge of coal-liquid mixtures

Energy Technology Data Exchange (ETDEWEB)

Peirce, T

1985-09-01

The near-term prospect for coal-water (CWMs) mixtures as a convenient replacement fuel for UK oil-fired plant is discussed. Specific use of CWMs in industrial water-tube boilers is presented. The article shows how such developments complement the introduction of new, modern coal-designed industrial combustion equipment in the form of fully automatic stokers and fluidized bed combustion systems. Topics presented include properties and preparation of CWM, combustion characteristics of CWM, and boiler conversion. 9 references, 4 figures.

Thermophysical properties of biodiesel and related systems: (Liquid + liquid) equilibrium data for castor oil biodiesel

International Nuclear Information System (INIS)

Mazutti, Marcio A.; Voll, Fernando A.P.; Cardozo-Filho, Lúcio; Corazza, Marcos L.; Lanza, Marcelo; Priamo, Wagner L.; Oliveira, J. Vladimir

2013-01-01

Highlights: ► (Liquid + liquid) equilibrium data for multicomponent castor oil FAME and FAEE castor oil. ► Tie-lines and solubility curves (binodal) by cloud-point method for FAME and FAEE systems. ► Experimental data correlated using the UNIQUAC model. -- Abstract: This work reports new liquid–liquid solubility values (binodal curves) as well as (liquid + liquid) equilibrium data for, ternary and quaternary systems containing fatty acid methyl esters (FAME) and fatty acid ethyl esters (FAEE) from castor oil, water, glycerol, methanol and anhydrous ethanol at T = (303.15, 318.15, and 333.15) K. Solubility curves (binodal) were also obtained by the cloud-point method for binary systems containing FAME, FAEE, water, or glycerol. All results obtained can be considered of good quality. The experimental values were correlated using the UNIQUAC model, whose results presented good performance and satisfactory fitting of equilibrium values

(Liquid + liquid) equilibria of {benzene + cyclohexane + two ionic liquids} at different temperature and atmospheric pressure

International Nuclear Information System (INIS)

Sakal, Salem A.; Shen, Chong; Li, Chun-xi

2012-01-01

Highlights: ► (Liquid + liquid) equilibrium for two quaternary and two ternary systems were measured. ► The components include cyclohexane, benzene, [MIM][BF4], [MIM][ClO4] and [MMIM][DMP]. ► The (liquid + liquid) equilibrium data can be well correlated by the NRTL model. ► Separation of benzene and cyclohexane by pure ILs and their mixtures were discussed. - Abstract: (Liquid + liquid) equilibrium data of the following ternary and quaternary systems at different temperatures and mass fractions of ionic liquids (ILs) were measured at atmospheric pressure, i.e., {cyclohexane + benzene + 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP])} at 298.2 K, {cyclohexane + benzene + 1-methylimidazolium tetrafluoroborate ([MIM][BF 4 ])} at 338.2 K, {cyclohexane + benzene + [MIM][BF 4 ] + [MMIM][DMP]} at (298.2 and 313.2) K, and {cyclohexane + benzene + 1-methylimidazolium perchlorate [MIM][ClO 4 ] + [MMIM][DMP]} at 298.2 K. The results indicate that both selectivity and distribution factor of the IL mixture for benzene are lower than that of pure IL [MMIM][DMP] at a specified condition, and decrease with the increase of the mass fraction of [MIM][BF 4 ] or [MIM][ClO 4 ] in its mixture of [MMIM][DMP] and the mole fraction of benzene. The extremely high selectivity of [MIM][BF 4 ] and [MIM][ClO 4 ] for aromatic compounds as predicted by the COSMOS-RS model is not justified by the present experimental results, and on the contrary, they show a relatively lower selectivity and extraction capacity for benzene than [MMIM][DMP].

Metal extraction by solid-liquid agglomerates

International Nuclear Information System (INIS)

Fuller, E.F.

1980-01-01

Dissolved metal values are extracted from a liquid e.g. uranium from phosphoric acid by contacting the liquid with agglomerates for a time to load the agglomerate with the metal value, separating the loaded agglomerates from the liquid phase and stripping the metal value from the loaded agglomerate. The agglomerate may be made by combining finely divided solid particles with a binding liquid to form a paste, adding a suspending liquid to form a mixture, the suspending liquid and binding liquid being immiscible in each other and the solid particles being insoluble in the suspending liquid and shearing the mixture to form the agglomerate. (author)

Diffusion in Liquids : Equilibrium Molecular Simulations and Predictive Engineering Models

NARCIS (Netherlands)

Liu, X.

2013-01-01

The aim of this thesis is to study multicomponent diffusion in liquids using Molecular Dynamics (MD) simulations. Diffusion plays an important role in mass transport processes. In binary systems, mass transfer processes have been studied extensively using both experiments and molecular simulations.

Equation of state for thermodynamic properties of pure and mixtures liquid alkali metals

International Nuclear Information System (INIS)

Mousazadeh, M.H.; Faramarzi, E.; Maleki, Z.

2010-01-01

We developed an equation of state based on statistical-mechanical perturbation theory for pure and mixtures alkali metals. Thermodynamic properties were calculated by the equation of state, based on the perturbed-chain statistical associating fluid theory (PC-SAFT). The model uses two parameters for a monatomic system, segment size, σ, and segment energy, ε. In this work, we calculate the saturation and compressed liquid density, heat capacity at constant pressure and constant volume, isobaric expansion coefficient, for which accurate experimental data exist in the literatures. Results on the density of binary and ternary alkali metal alloys of Cs-K, Na-K, Na-K-Cs, at temperatures from the freezing point up to several hundred degrees above the boiling point are presented. The calculated results are in good agreement with experimental data.

Effect of high-order multicomponent on formation and properties of Zr-based bulk glassy alloys

Energy Technology Data Exchange (ETDEWEB)

Inoue, A., E-mail: ainouebmg@yahoo.co.jp [International Institute of Green Materials, Josai International University, Togane 283-8555 (Japan); School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Department of Physics, King Abdulaziz University, Jeddah 22254 (Saudi Arabia); Wang, Z.; Louzguine-Luzgin, D.V. [WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Han, Y. [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Kong, F.L. [International Institute of Green Materials, Josai International University, Togane 283-8555 (Japan); Shalaan, E.; Al-Marzouki, F. [Department of Physics, King Abdulaziz University, Jeddah 22254 (Saudi Arabia)

2015-07-25

Highlights: • A multicomponent Zr{sub 55}Al{sub 10}Fe{sub 6}Co{sub 6}Ni{sub 6}Cu{sub 6}Pd{sub 6}Ag{sub 5} bulk glassy alloy was formed. • The high-order multiplication suppression of the decrease in mechanical strength. • The BGAs show good corrosion resistance and slow growth rate of primary precipitates. - Abstract: We examined the formation, thermal stability, mechanical properties and corrosion behavior of a multicomponent Zr{sub 55}Al{sub 10}Fe{sub 6}Co{sub 6}Ni{sub 6}Cu{sub 6}Pd{sub 6}Ag{sub 5} bulk glassy alloy, with the aim of clarifying the effect of high-order multiplication of the number of components on their properties. The bulk glassy alloy rods of 2 and 6 mm in diameter were formed by suction casting even at the low total content of typical glass-forming 3-d late transition metals like Co, Ni and Cu. The Vickers hardness is different in the center region and in the outer surface region. The difference seems to reflect the relaxation level of glassy structure. The Young’s modulus and the compressive fracture strength are nearly the same for the base Zr{sub 55}Al{sub 10}Ni{sub 5}Cu{sub 30} alloy in spite of the existence of immiscible atomic pairs. Moreover, the multicomponent alloy exhibits better corrosion resistance than that for the base alloy. The glassy phase changes to a supercooled liquid state at 720 K and then starts to crystallize at 754 K with a single exothermic peak, in contrast to the appearance of a wide supercooled liquid region for the base alloy. The primary crystalline phase precipitates with very short incubation time and very low growth rate, which are different from those for the base alloy. The extremely low growth rate of the crystallites is presumably due to the reduction of diffusivity of late transition metal elements resulting from multiplication. Thus, the high-order multiplication has the features of (1) the maintenance of high glass-forming ability even at the lower Co, Ni and Cu content and in the absence of

Experimental (liquid + liquid) equilibrium data for ternary and quaternary mixtures of fatty acid methyl and ethyl esters (FAME/FAEE) from soybean oil

International Nuclear Information System (INIS)

Beneti, Stéphani C.; Lanza, Marcelo; Mazutti, Marcio A.; Kunita, Marcos Hiroiuqui; Cardozo-Filho, Lúcio; Vladimir Oliveira, J.

2014-01-01

Highlights: • Innovative technique for quantification of compounds involved in the biodiesel production. • Easy and quick determination from NIR combined with multivariate calibration. • Reliable LLE correlation and predictions can be attained from the technique. -- Abstract: This work is aimed at providing an easy and quick determination of the biodiesel products using near infrared spectroscopy (NIR) by combination with the multivariate calibration in the analysis of (liquid + liquid) equilibrium (LLE) data for ternary and quaternary mixtures containing soybean fatty acid methyl (FAME) and ethyl (FAEE) esters, glycerol, ethanol, methanol and water, at various temperatures. The mass balance for the compositions obtained for each phase was carried out so as to demonstrate the reliability of the models generated by the multivariate calibration. Two distinct phases are observed, a glycerol-rich and the other ester-rich, while ethanol is dissolved among the phases hence reducing the partial mutual miscibility between glycerol and ester. Through (liquid + liquid) equilibrium (LLE) results, systems containing FAEE at T = 318.15 K and 303.15 K (calibration using data obtained at temperature of 318.15 K), a good agreement is verified among the values determined using conventional and NIR technique for alcoholic phase (AP) or aqueous phase (WP) and biodiesel phase (BP). Likewise in the systems containing FAME at 318.15 K, 303.15 K and 333.15 K (calibration using data obtained at temperature of 318.15 K), the LLE results were reproduced at the upper and lower temperature to the tests of the reproducibility of the models generated by the multivariate calibration

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.

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

International Nuclear Information System (INIS)

Dubey, Gyan Prakash; Kumar, Krishan

2011-01-01

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

Predicting Multicomponent Adsorption Isotherms in Open-Metal Site Materials Using Force Field Calculations Based on Energy Decomposed Density Functional Theory.

Science.gov (United States)

Heinen, Jurn; Burtch, Nicholas C; Walton, Krista S; Fonseca Guerra, Célia; Dubbeldam, David

2016-12-12

For the design of adsorptive-separation units, knowledge is required of the multicomponent adsorption behavior. Ideal adsorbed solution theory (IAST) breaks down for olefin adsorption in open-metal site (OMS) materials due to non-ideal donor-acceptor interactions. Using a density-function-theory-based energy decomposition scheme, we develop a physically justifiable classical force field that incorporates the missing orbital interactions using an appropriate functional form. Our first-principles derived force field shows greatly improved quantitative agreement with the inflection points, initial uptake, saturation capacity, and enthalpies of adsorption obtained from our in-house adsorption experiments. While IAST fails to make accurate predictions, our improved force field model is able to correctly predict the multicomponent behavior. Our approach is also transferable to other OMS structures, allowing the accurate study of their separation performances for olefins/paraffins and further mixtures involving complex donor-acceptor interactions. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Studies on the adsorption behavior of CO2-CH4 mixtures using activated carbon

Directory of Open Access Journals (Sweden)

R. B. Rios

2013-12-01

Full Text Available Separation of CO2 from CO2-CH4 mixtures is an important issue in natural gas and biogas purification. The design of such separation processes depends on the knowledge of the behavior of multicomponent adsorption, particularly that of CO2-CH4 mixtures. In this study, we present a series of experimental binary equilibrium isotherms for CO2-CH4 mixtures on an activated carbon at 293 K and compare them with predicted values using the Ideal Adsorption Solution Theory (IAST and the Extended Langmuir (EL model. Even at concentrations of ca. 20% for all binary isotherms, CO2 already presents higher adsorbed amounts with respect to CH4. A maximum selectivity of around 8.7 was observed for a nearly equimolar mixture at 0.1 MPa. The IAST in conjunction with the Toth equation showed slightly better results than IAST using the Langmuir equation and both showed better results than the EL model.

Semiclassical multicomponent wave function

NARCIS (Netherlands)

Mostovoy, M.V.

A consistent method for obtaining the semiclassical multicomponent wave function for any value of adiabatic parameter is discussed and illustrated by examining the motion of a neutral particle in a nonuniform magnetic field. The method generalizes the Bohr-Sommerfeld quantization rule to

Simultaneous multi-component seismic denoising and reconstruction via K-SVD

Science.gov (United States)

Hou, Sian; Zhang, Feng; Li, Xiangyang; Zhao, Qiang; Dai, Hengchang

2018-06-01

Data denoising and reconstruction play an increasingly significant role in seismic prospecting for their value in enhancing effective signals, dealing with surface obstacles and reducing acquisition costs. In this paper, we propose a novel method to denoise and reconstruct multicomponent seismic data simultaneously. This method lies within the framework of machine learning and the key points are defining a suitable weight function and a modified inner product operator. The purpose of these two processes are to perform missing data machine learning when the random noise deviation is unknown, and building a mathematical relationship for each component to incorporate all the information of multi-component data. Two examples, using synthetic and real multicomponent data, demonstrate that the new method is a feasible alternative for multi-component seismic data processing.

Gas-liquid equilibrium in mixtures of methane + m-xylene, and methane + m-cresol

Energy Technology Data Exchange (ETDEWEB)

Simnick, J J; Sebastian, H M; Lin, H M; Chao, K C

1979-01-01

Compositions of saturated equilibrium liquid and vapor phases as determined in a flow apparatus for methane + m-xylene mixtures at 370/sup 0/, 450/sup 0/, 520/sup 0/, and 600/sup 0/F (190/sup 0/, 230/sup 0/, 270/sup 0/, and 310/sup 0/C) and up to 200 atm, and for methane + m-cresol at 370/sup 0/, 520/sup 0/, 660/sup 0/, and 730/sup 0/F (190/sup 0/, 270/sup 0/, 350/sup 0/, and 390/sup 0/C) and up to 250 atm. Compared with published data on its solubility in benzene, methane appears to be more soluble in m-xylene at similar conditions but substantially less soluble in m-cresol. This difference indicates that the functional groups CH/sub 3/ and OH play different roles in determining the solubility of methane.

Pool Boiling of Hydrocarbon Mixtures on Water

Energy Technology Data Exchange (ETDEWEB)

Boee, R.

1996-09-01

In maritime transport of liquefied natural gas (LNG) there is a risk of spilling cryogenic liquid onto water. The present doctoral thesis discusses transient boiling experiments in which liquid hydrocarbons were poured onto water and left to boil off. Composition changes during boiling are believed to be connected with the initiation of rapid phase transition in LNG spilled on water. 64 experimental runs were carried out, 14 using pure liquid methane, 36 using methane-ethane, and 14 using methane-propane binary mixtures of different composition. The water surface was open to the atmosphere and covered an area of 200 cm{sup 2} at 25 - 40{sup o}C. The heat flux was obtained by monitoring the change of mass vs time. The void fraction in the boiling layer was measured with a gamma densitometer, and a method for adapting this measurement concept to the case of a boiling cryogenic liquid mixture is suggested. Significant differences in the boil-off characteristics between pure methane and binary mixtures revealed by previous studies are confirmed. Pure methane is in film boiling, whereas the mixtures appear to enter the transitional boiling regime with only small amounts of the second component added. The results indicate that the common assumption that LNG will be in film boiling on water because of the high temperature difference, may be questioned. Comparison with previous work shows that at this small scale the results are influenced by the experimental apparatus and procedures. 66 refs., 76 figs., 28 tabs.

Calculation and experimental investigation of multi-component ceramic systems

International Nuclear Information System (INIS)

Rother, M.

1994-12-01

This work shows a way to combine thermodynamic calculations and experiments in order to get useful information on the constitution of metal/non-metal systems. Many data from literature are critically evaluated and used as a basis for experiments and calculations. The following multi-component systems are treated: 1. Multi-component systems of 'ceramic' materials with partially metallic bonding (carbides, nitrides, oxides, borides, carbonitrides, borocarbides, oxinitrides of the 4-8th transition group metals) 2. multi-component systems of non-metallic materials with dominant covalent bonding (SiC, Si 3 N 4 , SiB 6 , BN, Al 4 C 3 , Be 2 C) 3. multi-component systems of non-metallic materials with dominant heteropolar bonding (Al 2 O 3 , TiO 2 , BeO, SiO 2 , ZrO 2 ). The interactions between 1. and 2., 2. and 3., 1. and 3. are also considered. The latest commercially available programmes for the calculation of thermodynamical equilibria and phase diagrams are evaluated and compared considering their facilities and limits. New phase diagrams are presented for many presently unknown multi-component systems; partly known systems are completed on the basis of selected thermodynamic data. The calculations are verified by experimental investigations (metallurgical and powder technology methods). Altogether 690 systems are evaluated, 126 are calculated for the first time and 52 systems are experimentally verified. New data for 60 ternary phases are elaborated by estimating the data limits for the Gibbs energy values. A synthesis of critical evaluation of literature, calculations and experiments leads to new important information about equilibria and reaction behaviour in multi-component systems. This information is necessary to develop new stable and metastable materials. (orig./MM) [de

Quantum liquids get thin

Science.gov (United States)

Ferrier-Barbut, Igor; Pfau, Tilman

2018-01-01

A liquid exists when interactions that attract its constituent particles to each other are counterbalanced by a repulsion acting at higher densities. Other characteristics of liquids are short-range correlations and the existence of surface tension (1). Ultracold atom experiments provide a privileged platform with which to observe exotic states of matter, but the densities are far too low to obtain a conventional liquid because the atoms are too far apart to create repulsive forces arising from the Pauli exclusion principle of the atoms' internal electrons. The observation of quantum liquid droplets in an ultracold mixture of two quantum fluids is now reported on page 301 of this issue by Cabrera et al. (2) and a recent preprint by Semeghini et al. (3). Unlike conventional liquids, these liquids arise from a weak attraction and repulsive many-body correlations in the mixtures.

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

Science.gov (United States)

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

2015-12-01

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

On the optimity of separation cascade for a binary and a multi-component case

International Nuclear Information System (INIS)

Song, T.M.; Zeng, S.

2006-01-01

The optimity discussed in this article means minimum total interstage flow which is studied for two cases, a binary and a multi-component case, using direct numerical optimizations for countercurrent symmetric cascades with the concentrations of the target component specified in the .feed flow, the product and waste withdrawals In binary separation, the ideal cascade in which there are no mixing losses and whose stages are working under symmetric separation is the optimum cascade that has the minimum total flow However when the separation factor is large, there may not exist an ideal cascade for certain prescribed external parameters. Cascades are optimized numerically to minimize mixing losses and total flows, respectively The results are compared for the minimum mixing losses and the minimum total flow, and analyzed with theoretically derived formulas. For the multi-component case, satisfying the non-mixing condition is impossible. There is a counterpart of the binary ideal cascade named MARC which matches the abundance ratio at mixing points. An optimization example for a four-cornponent mixture separation cascade is analyzed with the first and the last components as the targets, respectively. The results show that MARC is not the optimum cascade for the separation of one certain isotope. The separation power of each stage in the optimized cascades is calculated using several different definitions, and the rationality of these definitions is discussed. The Q-iteration method is used to calculate the concentration distribution in both the binary and the multi-component cases. Ns-2 stage cuts out of the Ns stages of the cascade are the optimization variables in the optimization process and a combination of the simulated annealing and the Hooke-Jeeves method is applied as the optimization technique to find the minimum. (authors)

The multi-component WKI hierarchy

International Nuclear Information System (INIS)

Yao Yuqin; Zhang Yufeng

2005-01-01

Firstly a new loop algebra G∼ M with 3M dimensions is constructed, which is devoted to establishing a new isospectral problem. Then the multi-component WKI hierarchy of soliton equations is obtained

Benchmarks for multicomponent diffusion and electrochemical migration

DEFF Research Database (Denmark)

Rasouli, Pejman; Steefel, Carl I.; Mayer, K. Ulrich

2015-01-01

In multicomponent electrolyte solutions, the tendency of ions to diffuse at different rates results in a charge imbalance that is counteracted by the electrostatic coupling between charged species leading to a process called “electrochemical migration” or “electromigration.” Although not commonly...... not been published to date. This contribution provides a set of three benchmark problems that demonstrate the effect of electric coupling during multicomponent diffusion and electrochemical migration and at the same time facilitate the intercomparison of solutions from existing reactive transport codes...

Handbook of heat and mass transfer. Volume 2

International Nuclear Information System (INIS)

Cheremisinoff, N.P.

1986-01-01

This two-volume series, the work of more than 100 contributors, presents advanced topics in industrial heat and mass transfer operations and reactor design technology. Volume 2 emphasizes mass transfer and reactor design. Some of the contents discussed are: MASS TRANSFER PRINCIPLES - Effect of turbulence promoters on mass transfer. Mass transfer principles with homogeneous and heterogeneous reactions. Convective diffusion with reactions in a tube. Transient mass transfer onto small particles and drops. Modeling heat and mass transport in falling liquid films. Heat and mass transfer in film absorption. Multicomponent mass transfer: theory and applications. Diffusion limitation for reaction in porous catalysts. Kinetics and mechanisms of catalytic deactivation. DISTILLATION AND EXTRACTION - Generalized equations of state for process design. Mixture boiling. Estimating vapor pressure from normal boiling points of hydrocarbons. Estimating liquid and vapor molar fractions in distillation columns. Principles of multicomponent distillation. Generalized design methods for multicomponent distillation. Interfacial films in inorganic substances extraction. Liquid-liquid extraction in suspended slugs. MULTIPHASE REACTOR SYSTEMS - Reaction and mass transport in two-phase reactors. Mass transfer and kinetics in three-phase reactors. Estimating liquid film mass transfer coefficients in randomly packed columns. Designing packed tower wet scrubbers - emphasis on nitrogen oxides. Gas absorption in aerated mixers. Axial dispersion and heat transfer in gas-liquid bubble columns. Operation and design of trickle-bed reactors

Acid digestion of organic liquids

International Nuclear Information System (INIS)

Partridge, J.A.; Bosuego, G.P.

1980-10-01

Laboratory studies on the destruction of liquid organic wastes by acid digestion are discussed. A variety of liquid waste types was tested, including those encountered in the nuclear industry as well as some organic liquids representative of non-nuclear industrial wastes. The liquids tested were vacuum pump oil, tri-n-butyl phosphate (TBP), normal paraffin hydrocarbon solvent (NPH), a mixture of 30 vol% TBP in NPH, carbon tetrachloride (CCl 4 ), trichloroethane, toluene, hexone (methyl isobutyl ketone), a mixture of hexone and NPH, polychlorobiphenyl (PCB), isopropanol, normal-decane, and two waste organic solutions from Hanford radioactive waste tanks. The tests demonstrated that several types of organic liquids can be destroyed by the acid digestion process. 8 figures, 19 tables

Thermophysical properties of biodiesel and related systems: (Liquid + liquid) equilibrium data for soybean biodiesel

International Nuclear Information System (INIS)

Mazutti, Marcio A.; Voll, Fernando A.P.; Cardozo-Filho, Lúcio; Corazza, Marcos L.; Lanza, Marcelo; Priamo, Wagner L.; Oliveira, J. Vladimir

2013-01-01

Highlights: ► (Liquid + liquid) equilibrium data for the systems of biodiesel production. ► LLE data for multicomponent FAME and FAEE from (303.15 to 333.15) K. ► Experimental data correlated using the UNIQUAC model. -- Abstract: This work reports (liquid + liquid) equilibrium (LLE) data for the systems of interest in soybean biodiesel production. Numerical data for LLE were obtained for binary, ternary and quaternary systems comprising fatty acid methyl esters (FAME) and fatty acid ethyl esters (FAEE) from soybean oil, water, glycerol, methanol, and ethanol at temperatures of (303.15, 318.15, and 333.15) K. Quantification of compounds in equilibrium in both phases was determined by analytical methods whereas solubility curves (binodal) were obtained by the cloud-point method. For all systems investigated, good alignments were obtained between phase compositions and the initial as well as overall compositions hence indicating low deviations from the mass balance. Experimental results were correlated using the UNIQUAC model with satisfactory agreement between experiment and theory

Flash Points of Secondary Alcohol and n-Alkane Mixtures.

Science.gov (United States)

Esina, Zoya N; Miroshnikov, Alexander M; Korchuganova, Margarita R

2015-11-19

The flash point is one of the most important characteristics used to assess the ignition hazard of mixtures of flammable liquids. To determine the flash points of mixtures of secondary alcohols with n-alkanes, it is necessary to calculate the activity coefficients. In this paper, we use a model that allows us to obtain enthalpy of fusion and enthalpy of vaporization data of the pure components to calculate the liquid-solid equilibrium (LSE) and vapor-liquid equilibrium (VLE). Enthalpy of fusion and enthalpy of vaporization data of secondary alcohols in the literature are limited; thus, the prediction of these characteristics was performed using the method of thermodynamic similarity. Additionally, the empirical models provided the critical temperatures and boiling temperatures of the secondary alcohols. The modeled melting enthalpy and enthalpy of vaporization as well as the calculated LSE and VLE flash points were determined for the secondary alcohol and n-alkane mixtures.

Relationship between composition of mixture charged and that in circulation in an auto refrigerant cascade and a J-T refrigerator operating in liquid refrigerant supply mode

Science.gov (United States)

Sreenivas, Bura; Nayak, H. Gurudath; Venkatarathnam, G.

2017-01-01

The composition of the refrigerant mixture in circulation during steady state operation of J-T and allied refrigerators is not the same as that charged due to liquid hold up in the heat exchangers and phase separators, as well as the differential solubility of different refrigerant components in the compressor lubricating oil. The performance of refrigerators/liquefiers operating on mixed refrigerant cycles is dependent on the mixture composition. It is therefore important to charge the right mixture that results in an optimum composition in circulation during steady state operation. The relationship between the charged and circulating composition has been experimentally studied in a J-T refrigerator operating in the liquid refrigerant supply (LRS) mode and an auto refrigerant cascade refrigerator (with a phase separator) operating in the gas refrigerant supply (GRS) mode. The results of the study are presented in this work. The results show that the method presented earlier for J-T refrigerators operating in GRS mode is also applicable in the case of refrigerators studied in this work.

Simultaneous obtention of multicomponent ferroalloy and slag from black sands for the development of electrical arc welding consumables

International Nuclear Information System (INIS)

Cruz-Crespo, A.; Gomez-Rodriguez, L.; Garcia-Sanchez, L. L.; Quintana-Puchol, R.; Cerpa-Naranjo, A.; Cores-Sanchez, A.

2004-01-01

In this paper, chemical and mineralogical characterizations of the black sands of the Mejias placer of Sagua de Tanamo (the most important beach littoral placer of the northwest of oriental Cuba) are exposed. Starting from these characterizations a calculation strategy is developed for the making of the metallurgical load that allows to obtain simultaneously, when processed by carbothermic reduction in an electrical arc furnace, a multicomponent ferroalloy and a useful slag for the making of electric arch welding consumables. The powder of the obtained slag is agglomerated with liquid glass. The resulting pellets, due to their behavior on the submerged arc welding (SAW) present technological and metallurgical properties that correspond with the requirements of an agglomerated flux matrix. The chemical composition of the multicomponent ferroalloy is constituted by metallic elements of high metallurgical and alloyed values (V, Cr, Mo, Ti, Nb). It is appropriate for the formulation of consumables for manual welding (SMAW) and SAW, as well. (Author) 15 refs

Liquid-liquid equilibria for binary and ternary systems containing glycols, aromatic hydrocarbons, and water: Experimental measurements and modeling with the CPA EoS

DEFF Research Database (Denmark)

Folas, Georgios; Kontogeorgis, Georgios; Michelsen, Michael Locht

2006-01-01

Liquid-liquid equilibrium data of four binary glycol + aromatic hydrocarbon systems and three ternary systems containing water have been measured at atmospheric pressure. The measured systems are monoethylene glycol (MEG) + benzene or toluene, triethylene glycol (TEG) + benzene or toluene, MEG...... + water + benzene, MEG + water + toluene, and TEG + water + toluene. The binary systems are correlated with the Cubic-Plus-Association (CPA) equation of state while the ternary systems are predicted from interaction parameters obtained from the binary systems. Very satisfactory liquid-liquid equilibrium...... correlations are obtained for the binary systems using temperature-independent interaction parameters, while adequate predictions are achieved for multicomponent water + glycol + aromatic hydrocarbons systems when accounting for the solvation between the aromatic hydrocarbons and glycols or water....

Separation of azeotropic mixtures : tools for analysis and studies on batch distillation operation

OpenAIRE

Hilmen, Eva-Katrine

2000-01-01

Separation of azeotropic mixtures is a topic of great practical and industrial interest. Most liquid mixtures of organic components form nonideal systems. The presence of some specific groups, particularly polar groups (oxygen, nitrogen, chlorine and fluorine), often results in the formation of azeotropes. Azeotropic mixtures may often be effectively separated by distillation by adding a liquid material (entrainer) to the system. For the development of separation processes for azeotropic ...

Monotonous and oscillation instability of mechanical equilibrium of isothermal three-components mixture with zero-gradient density

International Nuclear Information System (INIS)

Zhavrin, Yu.I.; Kosov, V.N.; Kul'zhanov, D.U.; Karataev, K.K.

2000-01-01

Presence of two types of instabilities of mechanical equilibrium of a mixture experimentally is shown at an isothermal diffusion of multicomponent system with zero gradient of density/ Theoretically is proved, that partial Rayleigh numbers R 1 , R 2 having different signs, there are two areas with monotonous (R 1 2 < by 0) instability. The experimental data confirm presence of these areas and satisfactory are described by the represented theory. (author)

Notre Dame Geothermal Ionic Liquids Research: Ionic Liquids for Utilization of Geothermal Energy

Energy Technology Data Exchange (ETDEWEB)

Brennecke, Joan F. [Univ. of Notre Dame, IN (United States)

2017-03-07

The goal of this project was to develop ionic liquids for two geothermal energy related applications. The first goal was to design ionic liquids as high temperature heat transfer fluids. We identified appropriate compounds based on both experiments and molecular simulations. We synthesized the new ILs, and measured their thermal stability, measured storage density, viscosity, and thermal conductivity. We found that the most promising compounds for this application are aminopyridinium bis(trifluoromethylsulfonyl)imide based ILs. We also performed some measurements of thermal stability of IL mixtures and used molecular simulations to better understand the thermal conductivity of nanofluids (i.e., mixtures of ILs and nanoparticles). We found that the mixtures do not follow ideal mixture theories and that the addition of nanoparticles to ILs may well have a beneficial influence on the thermal and transport properties of IL-based heat transfer fluids. The second goal was to use ionic liquids in geothermally driven absorption refrigeration systems. We performed copious thermodynamic measurements and modeling of ionic liquid/water systems, including modeling of the absorption refrigeration systems and the resulting coefficients of performance. We explored some IL/organic solvent mixtures as candidates for this application, both with experimentation and molecular simulations. We found that the COPs of all of the IL/water systems were higher than the conventional system – LiBr/H2O. Thus, IL/water systems appear very attractive for absorption refrigeration applications.

Timing of pathogen adaptation to a multicomponent treatment.

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Romain Bourget

Full Text Available The sustainable use of multicomponent treatments such as combination therapies, combination vaccines/chemicals, and plants carrying multigenic resistance requires an understanding of how their population-wide deployment affects the speed of the pathogen adaptation. Here, we develop a stochastic model describing the emergence of a mutant pathogen and its dynamics in a heterogeneous host population split into various types by the management strategy. Based on a multi-type Markov birth and death process, the model can be used to provide a basic understanding of how the life-cycle parameters of the pathogen population, and the controllable parameters of a management strategy affect the speed at which a pathogen adapts to a multicomponent treatment. Our results reveal the importance of coupling stochastic mutation and migration processes, and illustrate how their stochasticity can alter our view of the principles of managing pathogen adaptive dynamics at the population level. In particular, we identify the growth and migration rates that allow pathogens to adapt to a multicomponent treatment even if it is deployed on only small proportions of the host. In contrast to the accepted view, our model suggests that treatment durability should not systematically be identified with mutation cost. We show also that associating a multicomponent treatment with defeated monocomponent treatments can be more durable than associating it with intermediate treatments including only some of the components. We conclude that the explicit modelling of stochastic processes underlying evolutionary dynamics could help to elucidate the principles of the sustainable use of multicomponent treatments in population-wide management strategies intended to impede the evolution of harmful populations.

Multicomponent activation detector measurements of reactor neutron spectra

International Nuclear Information System (INIS)

Sandberg, J.; Aarnio, P. A.; Routti, J. T.

1984-01-01

Information on the neutron flux is required in many applications of research reactors, such as activation analysis or radiation damage measurements. Flux spectrum measurements are commonly carried out with activation foils. The reaction types used are threshold reactions in the fast energy region, resonance reactions in the intermediate region and neutron capture reactions with l/v-cross section in the thermal region. It has been shown that it is possible to combine several detector elements into homogeneous multicomponent detectors. The activities of all detector reaction products can be determined with a single gamma spectrum measurement. The multicomponent principle sets some restrictions on the choice of detector reactions, for example, each product nuclide may be produced in one reaction only. Separate multicomponent threshold and resonance detectors were designed for the fast and intermediate regions, respectively. The detectors were fabricated in polyethylene irradiation capsules or quartz glass ampoules, and they were irradiated in a cadmium cover. The detectors were succesfully used in the irradiation ring and in the core of a Triga reactor. The intermediate and fast neutron spectrum was unfolded with the least-squares unfolding program LOUHI. According to the preliminary results multicomponent activation detectors might constitute a convenient means for carrying out routine neutron spectrum measurements in research reactors. (orig.)

Oxygen reduction reaction properties of nitrogen-incorporated nanographenes synthesized using in-liquid plasma from mixture of ethanol and iron phthalocyanine

Science.gov (United States)

Amano, Tomoki; Kondo, Hiroki; Takeda, Keigo; Ishikawa, Kenji; Hiramatsu, Mineo; Sekine, Makoto; Hori, Masaru

2018-04-01

Nanographenes were synthesized using in-liquid plasma from a mixture of iron phthalocyanine and ethanol. In a previous study, micrometer-scale flakes with nitrogen incorporation were obtained. A nonprecious metal catalytic activity was observed with 3.13 electrons in an oxygen reduction reaction under an acidic solute condition. Large-surface-area, high-graphene-crystallinity, and iron-carbon-bonding sites were found owing to a high catalytic activity in Fe-N/nanographene.

Volumetric properties of binary liquid-phase mixture of (water + glycerol) at temperatures of (278.15 to 323.15) K and pressures of (0.1 to 100) MPa

International Nuclear Information System (INIS)

Egorov, Gennadiy I.; Makarov, Dmitriy M.

2014-01-01

Highlights: • Coefficients of compressibility of liquid binary mixture (water + glycerol) were measured. • Partial molar volumes of the components and excess molar volumes of the mixture were calculated. • Molar isothermal compression, molar isobaric expansion and molar isochoric elasticity of the mixture were evaluated. • Analysis of volume characteristics confirms glycerol hydrophilic nature. - Abstract: The coefficients of compressibility, k = ΔV/V o , of liquid binary mixture of {water (1) + glycerol (2)} were measured over the whole composition range at pressures from (0.1 to 100) MPa and temperatures from (278.15 to 323.15) K. Excess molar volumes of the mixture, V m E , partial molar volumes of the mixture components, V ¯ i , as well as their limiting values, molar isothermal compression K T,m , molar isobaric expansion E P,m , molar isochoric elasticity (isochoric coefficient of thermal pressure) β m were calculated. It was revealed that with glycerol molar fraction increasing the coefficients of compressibility, k, decreased to x 2 ≈ 0.3 ÷ 0.4 (where x 2 was glycerol molar fraction), and further changed insignificantly. It was shown that all isobars of excess molar volumes were negative and their absolute values, V m E , decreased on temperature and pressure rising. No extremes were observed on concentration dependences of partial molar volumes of glycerol in the mixture at its low concentrations. Under the state parameters studied limiting partial volumes of water and glycerol decrease with pressure rising but increase with temperature growth. Dependences of molar isothermal compression and molar isochoric elasticity on glycerol molar fraction passed extremes, and similar dependences of molar isobaric expansion had the temperature inversion regions

Studies on transport behaviour of a binary liquid mixture of ethanol and toluene at 298.15K in terms of viscosity models

Science.gov (United States)

Purohit, Suresh; Suthar, Shyam Sunder; Vyas, Mahendra; Beniwal, Ram Chandra

2018-05-01

The main transport properties of liquid or liquid mixtures are viscosity, diffusion, transference and electrical conductance. Viscosities of various liquid mixtures have been studied and their analyses have also been done by the help of some parameters. For each solution, the excess thermodynamic properties (YE) have been investigated. These excess thermodynamic properties are excess molar volume (VE), viscosity deviation (Δη) and excess Gibbs free energy of activation of viscous flow (ΔG*E). These parameters provide us the important information about interaction between molecules. For example, the negative value of VE and positive value of Δη shows the strong interaction between the solute and solvent molecules while positive value of VE and negative value of Δη shows the weak interaction between solute and solvent molecules. Above parameters and their discussion have been made in our earlier paper. In the present research paper, the viscosity data have been correlated with the equations of Grunberg and Nissan, Hind et al., Tamura and Kurata Katti. The excess values have been correlated using Redlich-Kister polynomial equation to obtain their coefficients and standard deviations. It has been found that in all cases, the data obtained fitted with the values correlated by the corresponding models very well. The results are interpreted in terms of molecular interactions occurring in the solution.

The use of computational thermodynamics for the determination of surface tension and Gibbs-Thomson coefficient of multicomponent alloys

Science.gov (United States)

Ferreira, D. J. S.; Bezerra, B. N.; Collyer, M. N.; Garcia, A.; Ferreira, I. L.

2018-04-01

The simulation of casting processes demands accurate information on the thermophysical properties of the alloy; however, such information is scarce in the literature for multicomponent alloys. Generally, metallic alloys applied in industry have more than three solute components. In the present study, a general solution of Butler's formulation for surface tension is presented for multicomponent alloys and is applied in quaternary Al-Cu-Si-Fe alloys, thus permitting the Gibbs-Thomson coefficient to be determined. Such coefficient is a determining factor to the reliability of predictions furnished by microstructure growth models and by numerical computations of solidification thermal parameters, which will depend on the thermophysical properties assumed in the calculations. The Gibbs-Thomson coefficient for ternary and quaternary alloys is seldom reported in the literature. A numerical model based on Powell's hybrid algorithm and a finite difference Jacobian approximation has been coupled to a Thermo-Calc TCAPI interface to assess the excess Gibbs energy of the liquid phase, permitting liquidus temperature, latent heat, alloy density, surface tension and Gibbs-Thomson coefficient for Al-Cu-Si-Fe hypoeutectic alloys to be calculated, as an example of calculation capabilities for multicomponent alloys of the proposed method. The computed results are compared with thermophysical properties of binary Al-Cu and ternary Al-Cu-Si alloys found in the literature and presented as a function of the Cu solute composition.

Multi-component fiber track modelling of diffusion-weighted magnetic resonance imaging data

Directory of Open Access Journals (Sweden)

Yasser M. Kadah

2010-01-01

Full Text Available In conventional diffusion tensor imaging (DTI based on magnetic resonance data, each voxel is assumed to contain a single component having diffusion properties that can be fully represented by a single tensor. Even though this assumption can be valid in some cases, the general case involves the mixing of components, resulting in significant deviation from the single tensor model. Hence, a strategy that allows the decomposition of data based on a mixture model has the potential of enhancing the diagnostic value of DTI. This project aims to work towards the development and experimental verification of a robust method for solving the problem of multi-component modelling of diffusion tensor imaging data. The new method demonstrates significant error reduction from the single-component model while maintaining practicality for clinical applications, obtaining more accurate Fiber tracking results.

Thermodynamic properties of mixtures of liquids