Solute Distribution Coefficient Research Articles

Effect of a variable solute distribution coefficient on mass separation in hollow fibers

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffect of a variable solute distribution coefficient on mass separation in hollow fibersAne M. Urtiaga, Angel Irabien, and Pieter StroeveCite this: Ind. Eng. Chem. Res. 1992, 31, 5, 1362–1366Publication Date (Print):May 1, 1992Publication History Published online1 May 2002Published inissue 1 May 1992https://doi.org/10.1021/ie00005a016RIGHTS & PERMISSIONSArticle Views163Altmetric-Citations11LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (576 KB) Get e-Alerts Get e-Alerts

Solute Element Distribution and Carbide Formation in Ni-Base Superalloys Fabricated by Rheocasting

An investigation was made on the effect of rotational stirring on the microstructures, distribution of solute elements, carbide formation, phosphorus segregation, and distribution coefficients between solid and liquid phases in the Ni-base superalloy TMP-3 (Ni-11. 15%Cr-6.74%Co-3.12%Mo-3.98%Al-2.74%Ti-3.93%Nb-3.25%W) by rheocasting with the rotation of a stirrer in the range of 20 to 70 rev/s. The main results obtained are summarized as follows: (1) When the TMP-3 superalloy was sufficiently agitated at 70 s -1 from the start of solification, the dentrite structure was broken up and an equiaxed grain structure with the average primary solid particle size of 65±15 μm was formed

Eutectic growth under rapid solidification conditions

The model for rapid solidification of eutectics developed recently by the authors is extended: (1) the effect of the localization of the diffusion field which leads to a complex series solution is described by an approximation which makes the prediction of eutectic microstructures a simple matter and (2) the loss of local equilibrium at the solid-liquid interface is taken into account through a growth rate-dependent effective liquidus slope and solute distribution coefficient, leading to a depression of the eutectic temperature and a substantial increase in the solute content of the eutectic phases at growth rates larger than some centimeters per second. The importance of high growth rate effect is demonstrated for a linearized phase diagram.

Solidification of highly undercooled Fe-P alloys

Rapid solidification behavior of highly undercooled iron-phosphorus alloys was investigated by using a high-speed optical temperature measurement system. The experimental results on solidification rate as a function of bulk undercooling agree well with a model which includes a treatment of nonequilibrium effects during the solidification process. The model is based on an earlier analysis by Boettinger, Coriell, and Trivedi[81] (BCT) and employs temperature-dependent values of equilibrium liquidus slope, equilibrium solute distribution coefficient, and solute interdiffusion coefficient. Values of the kinetic parameters,a0 andV0, in the analysis which best fit the experimental results are 5 x 10-10 m and 600 m/s, respectively. Comparison of experimental results and theory suggests that a transition from local equilibrium to nonequilibrium solidification takes place with increasing undercooling and that interface kinetic effects become predominant at higher undercooling (or growth velocity).

A Semidiscrete Model for Water and Solute Movement in Tile‐Drained Soils: 2. Field Validation and Applications

An exact‐in‐time two‐dimensional finite element model for simulating convective‐dispersive solute transport in a tile‐drained field is validated against observed data from a subsurface drainage experiment. The model is capable of predicting the long‐term effects of different irrigation and drainage practices on the salt distribution in an artificially drained soil‐aquifer system. The model was used to predict transient changes in the salinity of the soil, the shallow ground water table, and the drain effluent. Results are also presented on the effects of imposing alternative drain spacing‐depth combinations, initial groundwater salinities, solute distribution coefficients, and different types of layering of the aquifer, on the computed salinity distributions in the unsaturated zone, the groundwater, and the drain effluent.

回転撹拌凝固したNi基超合金における溶質元素の分布と炭化物生成

An investigation was made on the effect of rotational stirring on the microstructures, distribution of solute elements, carbide formation, phosphorus segregation, and distribution coefficients between solid and liquid phases in the Ni-base superalloy TMP-3 (Ni-11. 15%Cr-6.74%Co-3.12%Mo-3.98%Al-2.74%Ti-3.93%Nb-3.25%W) by rheocasting with the rotation of a stirrer in the range of 20 to 70 rev/s. The main results obtained are summarized as follows: (1) When the TMP-3 superalloy was sufficiently agitated at 70 s -1 from the start of solification, the dentrite structure was broken up and an equiaxed grain structure with the average primary solid particle size of 65±15 μm was formed

Evaluation of solute distribution coefficients in solubilized systems

A theoretical treatment is proposed for the determination of the distribution characteristics of a solubilizate between micellar and aqueous phases from the variation of the critical micelle concentration (CMC) with the molar ratio of components in the system. The theory has been tested by determining the distribution coefficient and free energy of solubilization of n-butanol in the n-butanol/sodium dodecyl sulphate/water system from CMC values determined by conductimetric techniques.

Modeling of solidification microstructures in concentrated solutions and intermetallic systems

Most of the theoretical models for the predictions of solidification microstructure and solute segregation are based on the assumption mat the solute distribution coefficient,k, is independent of temperature. For concentrated alloys and for alloys near intermetallic compounds,k may vary significantly with temperature. A theoretical analysis which shows the necessary modifications in the theoretical models which must be made ifk varies with temperature is developed. It is shown that for phase diagrams with linear liquidus and solidus segments, many of the results derived with constantk can be used if the solute distribution coefficientk is replaced by a modified parameterk* which includesk as well as the derivative ofk with composition. The application of the model to concentrated alloys and to compositions near intermetallic phases is discussed. It is shown that the variation ink with temperature can significantly alter the composition dependence of dendritic microstructural scales and change the solute segregation profiles in solidified alloys.

Solvent Selection for Extraction from Dilute Solution

An improved strategy for the selection of solvents for recovery of chemicals from dilute solution is presented. Low solvent losses and a high solute distribution coefficient are primary goals for solvent selection. High relative volatility of the solvent also is an important property if the solute is to be recovered from the extract by distillation. Low solvent losses will ensure adequate selectivity and the formation of two phases. High solute-solvent boiling point difference will increase the relative volatility and reduce the chance of azeotrope formation. The dependence of these properties on solvent structure is examined in some detail, and this indicates guidelines for the selection of solvents with the desired properties. The strategy is illustrated with the example of 1-butanol recovery.

Solvent effects in organic chemistry — recent developments

Solvent effects on a number of different processes have been surveyed, and results of the application of multiple linear regression analysis are discussed. The processes examined include examples of solubility of gases or vapours, distribution coefficients of solutes between water and a series of solvents, and solvent effects on conformational equilibria, on keto–enol tautomerism, and on reaction rates. It is shown that two particular equations, that due to Koppel and Palm and extended by Makitra and Pirig, and that due to Abraham, Kamlet, and Taft, can cope quite satisfactorily with solvent effects on these various processes. It is pointed out that interpretation of parameters obtained from equations that involve macroscopic quantities such as ΔG≠ or ΔG0 is not necessarily straightforward, and that some model is needed in order to interpret these macroscopic quantities in terms of microscopic quantities that can characterise, for example, solute–solvent interactions.

Gradient elution for micellar electrokinetic capillary chromatography

A method for performing gradient elution in micellar electrokinetic capillary chromatography is developed. The influence of temperature and mobile phase organic solvent concentration on capacity factors is presented and attributed to changes in phase ratio and solute distribution coefficient. Solvent programming is more effective than temperature programming at adjusting retention due to its greater influence on distribution coefficient. As anticipated, phase ratio changes could not be exploited due to concomitant losses in column efficiency. A stepwise solvent gradient involving increasing concentrations of 2-propanol and Triton-X-100 is used for the separation of a test mixture of derivatized amines.

Thermodynamic treatment of solid/liquid equilibrium distribution coefficients of solutes in multi-component iron alloys.

In this work, the thermodynamic treatment of the equilibrium distribution coefficient kXo in iron base ternary alloys described in the previous work1, 2) was developed for iron base multi-component alloys and the effects of solute-interactions on the equilibrium distribution coefficient in multi-component iron alloys were discussed thermodynamically. A new paramete for the evaluation of such effects was introduced. Furthermore, the equilibrium distribution coefficients of Cr, Ni, Si, Mn and Mo at various compositions in Fe-Cr-Ni base alloys were measured. Small dependence of kXo of those elements on the concentrations of Cr and Ni in those alloys was found and those results were explained by the application of new parameter.

Equiaxed dendrite growth in alloys at small supercooling

A dimensionless model for growth of equiaxed dendrites in alloys under small Peclet number conditions is presented. The behavior of this model is compared with that of Karma and Langer and to experiments of Chopra. Good agreement between both models and with experiments is found. It is shown that the maximum in growth rate,viz., minimum in tip radius with composition, depends strongly on the ratio of heat-to-solute diffusivity and on the solute distribution coefficient.

In situ voltammetric determinations of solute distribution coefficients in emulsions

A method to measure distribution coefficients ( P) of electroactive species in situ in turbid oil-in-water emulsions has been developed and is illustrated for the partitioning of 4-methyl-3-amino- N,N-diethylaniline ( 2) between oil and aqueous phases in an aqueous gelatin/1-undecanol emulsion at 40°C ( P = 55 ± 2). Voltammetry at a rotating platinum disk electrode is used as a probe of 2 concentration in the aqueous gelatin phase. Rheological effects due to the microheterogeneous nature of the emulsion on the limiting currents are quantitatively characterized by the use of 4-amino-3-methyl- N-ethyl- N-(β-sulfoethyl)aniline ( 1), which does not partition measurably into the oil phase.

Liquid Chromatography with Mixed Mobile Phases: Interpretation of the Model Chromatographic Data by Means of the Simple Linear Relationship

Abstract A discussion is presented concerning the application of the simple linear relationships In Ks vs. In x and In Ks vs. x, where Ks is the solute distribution coefficient and x is the mole fraction of the more efficient eluting solvent in the mobile phase, for analysing LC data calculated for different chromatographic models. It is shewn that these linear relationshipo give a satisfactory representation of the LC data relating to none different models in a limited concentration region of the more efficient eluting solvent. Hence, it in difficult to select the LC nodel properly representing a given chromatographic system on the basis of the parameters obtained by fitting LC data to these linear relationships.

Local composition models in pharmaceutical chemistry. I. Liquid-liquid distribution coefficients from COMMON UNIQUAC parameters

A literature compilation of COMMON UNIQUAC parameters has been employed to correlate mutual solubilities in binary and ternary systems on one side and distribution coefficients between water and organic solvent of infinitely diluted liquid solutes, K d , on the other. The following organic solvents were considered: butan-1-ol, 2-methylpropan-l-ol, ethyl acetate, chloroform, octan-1-ol. benzene, hexane, cyclohexane, heptane, octane and 2,2,4-trimethylpentane. Satisfactory K d predictions were observed for various solutes in 2-methylpropan-l-ol/water and butan-1-ol/water and ethyl acetate/water. For all other systems, the reliability of predicted K d values decreased with decreasing mutual saturabilities, outliers being most frequently found among alkane/water distribution coefficients of hydrogen-bonding and acidic solutes. These results are comparable to those of previous empirical correlation studies and much better than those produced by a solubility parameter concept.

Effects of solute-interaction on the equilibrium distribution of solute between solid and liquid phases in iron base ternary system.

In order to describe the effects of solute-interactions on the equilibrium distributions of solute elements between solid and liquid phases in iron base ternary system, Distribution Interaction Coefficient (DIC), kji, was defined in this work. The coefficient kji is shown as the ratio of the equilibrium distribution coefficient of solute i in Fe-i-j ternary system to that in Fe-i binary one and this is considered to be the parameter indicating the change of the equilibrium distribution coefficient of solute i with the additon of the alloying element j. The influences of solute-interaction on the equilibrium distributions of some solutes in Fe-C, Fe-N, Fe-H, Fe-P and Fe-S base ternary systems could be discussed by the use of the coefficient DIC.

A physicochemical approach for the choice of polymeric membrane materials for water desalination by reverse osmosis

Interfacial properties such as the thickness of interfacial water layer, the distribution coefficient of solute between interfacial and bulk water phases, and the volume of interfacial water per unit mass of polymer material have been identified as relevant physicochemical quantities governing reverse osmosis transport and determined by gas and liquid chromatography methods with respect to different polymeric membrane materials. They are further split into the contribution from the structural component of polymer repeating unit. Force constants A and D for sodium chloride, representing the repulsive force working between membrane surface and solute, have been calculated on the basis of inter-facial properties obtained above. Using these force constants, the pore sizes required to achieve 99.9% of sodium chloride separation are obtained for different polymeric membrane materials. Furthermore, the prediction procedure for the effect of preferentially adsorbed organic molecules on the separation of sodium chloride and product rate is illustrated as a model for “fouling” in the desalination process by reverse osmosis.

Retention time and effective separation factor in series‐coupled columns with different stationary phases

AbstractBasic expressions are derived for both the retention time and the effective separation factor in serially coupled GC columns. The retention time is determined by two main parameters. The first is the fractional time spent by an unretarded solute in each column which, in turn, is determined by the relative column lengths and flow velocities through each column. The second parameter is the relative mass distribution coefficient of a particular solute in each column; a variable that can be adjusted by changing the relative temperatures of the columns. The expression for the effective separation factor relates the measured separation factor for the series combination to the separation factors on the individual columns, the fractional time spent by an unretarded peak in each column, as well as the relative values of the mass distribution coefficients of a particular solute on the different columns.

Analysis of dispersion mechanism in gel chromatography. II. Dispersion mechanism in gel chromatography of proteins.

The dispersion mechanism in gel chromatography of proteins was quantitatively studied on the basis of a dispersion model which gave consideration to the contribution of gel phase diffusion and longitudinal dispersion in a column. Particularly, the effect of gel phase diffusion was examined in detail by comparing the values determined by applying the moment analysis to the elution curve and those obtained for a single gel bead.When the distribution coefficient of solute was small and the particle size of gel was large, the elution curve was asymmetrical and had a prolonged tail of low concentration. The gel phase diffusion coefficient determined from the elution curve was much higher than that for a single gel bead owing to the effect of the tail. This suggested that only a small portion near the gel bead surface was accessible to most of the solute applied owing to the much lower diffusion velocity in gel than the superficial velocity. The column efficiency improved as compared with the theoretical result...