bluuebunny/crossref_metadata_2025_split huggingface dataset:
The viscosity of liquid metals
Authors: Chapman Thomas W. 
Published: June 2004

AbstractIn order to make the kinetic theory of liquid viscosity tractable, an approximate from is suggested for the perturbation of the radial distribution function of a monatomic liquid by a nonuniform flow field. Substitution of this form into the microscopic expression for the pressure tensor yields an equation for liquid viscosity in terms of the equilibrium distribution function and the interatomic potential energy function. This equation establishes the basis for a corresponding states correlation of the viscosity of liquid metals based on atomic parameters.The viscosity data for twenty‐one molten metals are made to fall on a single curve by the adjustment of one microscopic parameter. It is found that this empirically determined parameter has the proper fundamental significance. Therefore it is possible to estimate it independently and to use the general correlation for estimating the viscosity of a metal for which data are not available. Also it is suggested that the atomic parameters determined from viscosity data in this way might be used to correlate other properties of the liquid metals.
Stability of falling liquid films. Effect of interface and interfacial mass transport
Authors: Whitaker Stephen , Jones L. O. 
Published: June 2004

AbstractPrevious studies of the effect of surface active agents on the stability of falling liquid films indicated that surface elasticity was primarily responsible for the observed stabilizing action. Since the elastic nature of a surface is thought to be controlled by interface and interfacial mass transport, it is of interest to understand how these transport rates affect the stability of the liquid film. The analysis for both soluble and insoluble surface active agents is presented in terms of a perturbation solution of the Orr‐Sommerfeld equation.
Experimental vapor‐liquid equilibrium data for propane‐isobutane
Authors: Hipkin Howard 
Published: June 2004

AbstractIsothermal vapor‐liquid equilibrium data for propane‐isobutane, a system of industrial importance, have been obtained in two pieces of apparatus at temperatures from 20° to 250°F. Over this temperature range, propane‐isobutane form ideal solutions. The paper discusses the sampling errors which occur in volatile systems.
Ion exchange equilibria under pressure
Authors: Hamann S. D. , McCay I. W. 
Published: June 2004

AbstractPrevious work on the ionization equilibria of weak acids and bases at high pressures suggested that compression should favor the transfer of protons from a weakly acidic resin to a weakly basic one in a mixed bed system, and that the resulting increase of ionization should extract cations and anions from the surrounding solution. In agreement with this idea it has now been observed that the equilibrium concentration of a solution of sodium chloride around a mixture of De‐Acidite M and Zeo‐Karb 226 resins is almost halved when the pressure is raised from 1 to 3,000 atm. The change is completely reversible.The measurements indicate that the proton transfer process involves a contraction of about 15 cc. mole−1, which is remarkably close to the analogous contraction [15 to 18 cc. mole−1] that occurs when a proton is transferred from a free carboxylic acid to an amine in solution.
An experimental study of falling liquid films
Authors: Jones L. O. , Whitaker Stephen 
Published: June 2004

AbstractA new method for measuring wavelength and wave velocity is described, and experimental values for water flowing down a vertical plane are compared with a numerical solution of the Orr‐Sommerfeld equation. Good agreement is obtained in the region near the top of the film where small disturbance theory is expected to be valid. Experimental Reynolds numbers ranged from 8 to 120.
Effects of product recycle and temperature on autocatalytic reactions
Authors: Ahn Yong‐Kee , Fan Liang‐Tseng , Erickson Larry E. 
Published: June 2004

AbstractThe effect of product recycle and temperature on the maximum yield of product for several different autocatalytic reactions taking place in a tubular reactor is studied.A generalized version of the maximum principle is used to determine the maximum conversion and optimal temperature profile for each of the reactions considered. The fraction of product recycled, which affects the concentration of autocatalytic agent entering the reactor, is investigated to determine its effect on the maximum conversion.
Diffusion of gases in electrolytic solutions
Authors: Gubbins Keith E. , Bhatia Kamlesh K. , Walker Robert D. 
Published: June 2004

AbstractMeasurements of the diffusion coefficients of hydrogen and methane in strong aqueous electrolytes have been made with the use of the diaphragm cell method. The variation of the diffusion coefficients with electrolyte concentration, type of ion, and temperature has been studied over the electrolyte concentration range zero to saturated, and for temperatures in the range 25° to 65°C.The results have been interpreted with the Eyring rate theory. The presence of ions in water increases the activation energy for diffusion which results in a decrease in the diffusion coefficient. The increase in activation energy is represented by terms that are additive for the ions involved. The influence of ions on the diffusion coefficient increases rapidly with ionic charge, but seems to be little affected by temperature or solute for the systems studied.
Heat transport and temperature distributions in large single drops at low Reynolds numbers: A new experimental technique
Authors: Head Harlan N. , Hellums J. D. 
Published: June 2004

AbstractA new experimental technique has been developed for study of transport from drops. Large single drops are heated dielectrically while suspended motionless in an unheated continuous phase. Direct measurements of temperature distributions within drops are presented both for circulating drops and for drops in which surface‐active materials retard circulation. The results of the measurements will be useful in assessing the validity of the various proposed models.
Application of the Wohl equation to ternary liquid‐vapor equilibria
Authors: Adler Stanley B. , Friend Leo , Pigford Robert L. 
Published: June 2004

AbstractThe use of the Wohl equation for activity coefficients is tested successfully for the most nonideal ternary systems for which experimental data could be found. The three‐suffix form possessing seven constants is found to be successful in many cases. Owing to the high degree of nonideality resulting from one or more components being polar, however, the four‐suffix form employing up to ten constants was required for ten of the twenty‐five ternaries studied. Regardless of the form chosen, all the constants but one, C*, are derived from phase equilibrium data on the constituent binaries.The ternary constant C* was found to be approximately zero. In only two instances did its value not fall in the region of −1.0 to +1.0. With the use of the binary constants and C*, predictions of vapor compositions were made for each experimental ternary liquid composition, temperature, and pressure. The results so obtained yielded average absolute errors in predicted vapor mole fractions, without respect to sign, as follows: for ten systems, less than 0.01; for seventeen systems, less than 0.02; and for twenty‐four systems, less than 0.03. For an additional three sets the error was still less than 0.05. Results were analyzed statistically for twenty‐two of the systems determining mean values of the vapor mole fraction deviations and the confidence limits of the means.The mass testing of the Wohl equation reported here far exceeds the sum of all work previously published in the literature. It appears that this equation provides a very good way of expressing liquid nonideality for a wide range of components.
Uniform flux heat transfer to a gas in laminar forced convection in a circular tube
Authors: Bergman Perry D. , Koppel Lowell B. 
Published: June 2004

AbstractHeat transfer from a circular tube to a contained gas in laminar forced convection was studied dimensionally and experimentally. The boundary condition of uniform heat flux was physically achieved, and the experiments were conducted in a statistically designed pattern. The dimensional analysis, based upon the principle of corresponding states, and more general than any hitherto proposed, indicated four independent variables in this experiment. Of these, only bulk velocity showed a statistically significant effect in the region studied: a reduction in heat transfer coefficient with decreasing bulk velocity. No existing theories could explain this effect.
Stability of autorefrigerated chemical reactors
Authors: Luyben William L. 
Published: June 2004

AbstractStability of exothermic chemical reactors with cooling jackets or internal cooling coils has been extensively studied by steady state, phase plane, and linear analysis techniques. The purpose of this paper is to apply these techniques to the frequently encountered case of autorefrigerated or boiling liquid reactors. In these reactors the exothermic heat of reaction is removed, not by conductive and convective heat transfer, but by vaporization of a liquid phase or, more generally, by any kind of endothermic change in phase.Open‐loop and closed‐loop stability of a continuous stirre‐tank autorefrigerated reactor is studied. General equations are derived and illustrated by numerical examples.Both constant and variable latent heats of vaporization are considered. A particularly interesting aspect of autorefrigerated reactor stability is operation near the critical temperature. Since the latent heat approaches zero, instability of the system is increased, representing a form of positive feedback in a chemical system.
Newtonian jet stability
Authors: Grant Rollin Peter , Middleman Stanley 
Published: June 2004

AbstractAlthough Newtonian jet stability has been the object of numerous experimental and theoretical studies, the total problem of jet disintegration is by no means solved. Theories available in the literature are only applicable to low‐speed laminar jets in stagnant air. In practice, the stability of a liquid jet may be influenced by the ambient medium, turbulence in the nozzle, and the extent of development of the velocity profile. None of these factors has received adequate study. This work presents the beginning of a systematic evaluation of the role played by these factors in the destabilization of a liquid jet. Correlations are presented for predicting the stability of both turbulent and high‐speed laminar jets in stagnant air.
Phase equilibria in polymer solutions
Authors: Heil J. F. , Prausnitz J. M. 
Published: June 2004

AbstractA new semiempirical equation is presented for the Gibbs energy of mixing for solutions of polymers in single and mixed solvents. The equation contains two adjustable parameters per binary mixture and can readily be extended to multicomponent systems without additional parameters. The new expression gives a very good representation of the properties of a variety of polymer solutions including those in which there are strong specific interactions such as hydrogen bonding. Parameters are determined from binary vapor pressure data.A graphical method based on the new equation is given for predicting solubility limits in ternary systems containing one polymer and a mixed solvent. Only binary data are used. The method is demonstrated by comparisons of predicted solubility behavior with new experimental data taken on systems composed of polystyrene and the following mixed solvents: acetone‐toluene, acetone‐benzene, methanol‐benzene, methanol‐ethyl acetate, and acetone‐methylcyclo‐hexane.
Reaction of chlorine and uranium tetrachloride in the fused lithium chloride‐potassium chloride eutectic
Authors: Olander Donald R. , Camahort J. L. 
Published: June 2004

AbstractThe rates of the reaction of chlorine gas with uranium tetrachloride dissolved in the lithium chloride‐potassium chloride eutectic have been studied in a wetted‐rod contactor. The reaction was studied at temperatures from 400° to 700°C., uranium tetrachloride concentrations of 1 to 3 wt. %, and chlorine partial pressures of 0.25 to 1 atm. The production of uranium hexachloride appears to be limited by the equilibrium of the reaction UCL4 (solution) + Cl2 (g) = UCl6 (solution) at the interface and by U+4 diffusion in the liquid phase.
Similarity solutions for non‐Newtonian fluids
Authors: Lee S. Y. , Ames W. F. 
Published: June 2004

AbstractSimilarity transformations are possible for power law fluids in the following systems: momentum transfer in general Falkner‐Skan flows and Goldstein flows; and momentum and energy transfer in forced convection about a right angle wedge, natural convection with constant heat flux at the boundary surface, and general Falkner‐Skan flows with nonconstant heat conductivity and a restricted boundary temperature distribution. Similarity transformations are also possible for momentum and heat transfer of Eyring viscous fluids about a right angle wedge. A numerical solution is obtained for forced convection of power law fluids about a right angle wedge with an isothermal surface. From the numerical results an approximate expression is obtained for the local Nusselt number.
Laminar‐Turbulent transition for nonisothermal pipe flow
Authors: Scheele George F. , Greene Howard L. 
Published: June 2004

AbstractFinite disturbance pipe flow stability criteria are evaluated for constant flux heating of liquids flowing through vertical pipes under small disturbances conditions where velocity profile distortion due to natural convection is significat. For Newtonian flow in long heated pipes the analysis of Hanks correctly predicts the transition to turbulence observed for upflow heating and is qualitatively consistent with the transition to asymmetric flow which occurs in downflow heating, whereas the criterion of Ryan and Johnson predicts stability for experimentally unstable flows. In the practically more important case of short pipe lengths experimental data obtained over the viscosity range from 1 to 21 centiposises show that natural convection induced transition will occur at low Reynolds numbers for both Newtonian and non‐Newtonian liquids for conditions consistent with predictions of Hanks' analysis.
The incipience of nucleate boiling in forced convection flow
Authors: Davis E. J. , Anderson G. H. 
Published: June 2004

AbstractAn analysis of the incipience of nucleate boiling is developed as a modification and extension of previous analyses. The results are compared with data for subcooled boiling of water in forced convection flow. Apparent anomalies in the data for the onset of boiling in two‐phase gas‐liquid flow are shown to be a result of a limited size range of cavities on the heater surfaces. Measurements of the surface characteristics of a copper heating tube were made and compared with incipient boiling heat transfer data taken in that tube. The results predicted from the theoretical analysis are consistent with the experimental heat transfer data.
Vapor‐Liquid equilibria for five cryogenic mixtures
Authors: Sprow F. B. , Prausnitz J. M. 
Published: June 2004

AbstractPhase equilibrium data have been obtained for the binary systems nitrogen‐argon and nitrogen‐carbon monoxide at 83.82°K. and for the systems nitrogen‐methane, argon‐methane, and carbon monoxide‐methane at 9.67°K. Total pressures and compositions of both phases were measured. Parameters have been calculated for the Redlich‐Kister and Wilson equations for the excess Gibbs energies of the mixtures. The data are thermodynamically consistent within experimental error.
Shape of liquid drops moving in liquid media
Authors: Wellek R. M. , Agrawal A. K. , Skelland A. H. P. 
Published: June 2004

AbstractAn investigation of the effects of various physical properties, drop size, and drop velocity on drop shape was carried out for nonoscillating liquid drops falling through stationary liquid continuous phases. The data of forty‐five dispersed‐continuous phase systems were studied with continuous phase viscosities varying from 0.3 to 46 centipoise and interfacial tensions varying from 0.3 to 42 dyne/cm. A theoretical relation was obtained from the Taylor and Acrivos analysis which quite accurately predicts drop eccentricities for drop Reynolds numbers less than about 20, but is highly inaccurate at higher Reynolds numbers. Relatively simple empirical relations involving the Weber number, Eötvös number, and viscosity ratio were obtained which enable the prediction of the eccentricity of nonoscillating drops over a wide range of Reynolds numbers (6.0 to 1,354) with average deviations of 6 to 8%. These relations may be useful in the estimation of the interfacial area, velocity, and continuous phase mass transfer coefficient of drops distorted from spherical shape.
Laminar dispersion in capillaries: Part II. Effect of inlet boundary conditions and turner type of system capacitance
Authors: Gill William N. , Ananthakrishnan V. 
Published: June 2004

AbstractThe effect of inlet boundary conditions on the transient approach to the asymptotic Taylor‐Aris theory was studied for three different cases. It was found that for values of τ of practical interest the solutions for these cases were different only if NPe < 100. The asymptotic solution was independent of inlet conditions in the three cases studied once τ exceeded the necessary minima.A rather complete numerical solution to the equation that describes laminar flow in tubes with a single continuous stagnant pocket of arbitrary depth along the entire length of the pore has been obtained, and results for point, average, and bulk concentration distributions are presented for a wide range of parameters. The range of applicability is extended to infinity for both τ and NPe by the asymptotic theory of Aris.Higher capacitance systems require longer times before their dispersion behavior can be described by error‐function solutions. This is important, since only then is the concept of an equivalent axial dispersion coefficient useful because then it allows the calculation of the complete average concentration distribution from a minimum of data. This suggests that in work on high capacitance systems such as packed beds, one should ensure that experimental systems are long enough for the asymptotic theory to apply if results are to be interpreted in terms of dispersion coefficients.Numerical results for the Turner model agree very well with the modified effective dispersion coefficient, which was suggested by Aris and is given in Equation (15), as long as τ is sufficiently large. These lower limits for τ are given in Table 3. When the lower limits on τ are exceeded, the new solution developed for the point distribution given by Equations (31) and (32) is also valid. This is important for at least two reasons. First, it implies that the dispersion model can be used to describe the local as well as the average behavior of complex transient systems if only the velocity distribution across the system is known. More work is needed to ascertain the limitations and possibilities of the dispersion model in this regard. Second, it shows that one can find simple and accurate approximate local solutions without neglecting axial molecular diffusion.
Viscosities of methane and propane at low temperatures and high pressures
Authors: Huang E. T. S. , Swift G. W. , Kurata Fred 
Published: June 2004

AbstractThe viscosities of methane and propane were determined at pressures to 5,000 lb./sq. in. abs. over a temperature range from −170° to 0°C. and −100° to 0°C., respectively, and the densities of propane were measured at pressures to 5,000 lb./sq. in. abs. over the temperature range from −100° to 0°C. Reproducibility of the viscosity data was about ± 1.2% and for the most part agreement with literature values was within ± 2%. the estimated accuracy of the density measurement was ± 0.5%. The data reported were well correlated in terms of residual viscosity vs. density.
Theoretical study of fluid flow accompanied by solid precipitation in porous media
Authors: Kuo Chiang‐Hai , Closmann Philip J. 
Published: June 2004

AbstractThis paper deals with compressible fluid flow accompanied by solid deposition in a porous reservoir. The isothermal fluid flow is considered to be radial and follows Darcy's law. The initially dissolved substances precipitate from the solution as a result of solubility reduction as the pressure declines. These deposits accumulate in the void spaces and hence inhibit the flow. An idealized model describing this transport mechanism has been proposed. On the basis of this model, a numerical technique has been developed to predict the amount of solid precipitation and the pressure distribution as functions of time and radial distance.The method is applied to the production performance of a reservoir containing mainly hydrogen sulfide saturated with elemental sulfur. The solid sulfur builds up rapidly in the vicinity of the production well. A very negligible amount is formed close to the impermeable outer boundary. It is shown that plugging by solid sulfur in the porous medium can be reduced either by reducing the production rate or by choosing closer well spacing.
Coalescence in fibrous beds
Authors: Sareen S. S. , Rose P. M. , Gudesen R. C. , Kintner R. C. 
Published: June 2004

AbstractThe factors affecting the efficacy of a closely packed bed of mixed cotton and a supporting fiber (Teflon, glass, Dynel) were evaluated for oil‐in‐water dispersions. Several other water‐organic systems were also tested. Superficial velocities ranged from 0.2 to 3.5 ft./min. Successful coalescence was attained at interfacial tensions as low as 3.5 dynes/cm. Dispersed phase viscosity was varied form 1.4 to 137 centipoise. For a mixed‐fiber bed with a specific ratio of fiber species, there is an optimum bed depth for best performance. High‐speed cinephotomicrographic observations at 100 × and up to 4,000 frames/sec. indicated that fiber wettability is not the most important factor for successful operation.
Transport properties of a dense fluid of molecules interacting with a square‐well potential: Part II
Authors: Luks K. D. , Miller M. A. , Ted Davis H. 
Published: June 2004

AbstractThe equations developed by Davis, Rice, and Sengers for the transport properties of a model fluid whose molecules interact according to a square‐well potential are utilized herein to calculate the transport coefficients of krypton, xenon, and argon. With the use of theoretically determined pair correlation functions and experimental P‐V‐T data, results are obtained that indicate that the square‐well theory provides a useful model for simple liquids. Master graphs of the transport coefficients as functions of reduced parameters are presented. An investigation of the relative importance of the contributions by kinetic transfer and by intermolecular collisional transfer leads to the conclusion that kinetic transfer can provide a sizable contribution to transport properties.
Diffusion and solution of gases in thermally softened or molten polymers: Part I. Development of technique and determination of data
Authors: Durrill Preston L. , Griskey Richard G. 
Published: June 2004

AbstractA technique has been developed that determines simultaneously solubilities and diffusivities of gases in molten or thermally softened polymers. Henry's law was found to hold up to 20 atm. In addition it was found that pressure had no appreciable effect on diffusion coefficients up to 20 atm. Solubilities and diffusivities were determined for systems involving nitrogen, helium, carbon dioxide, and argon in polyethylene, polyisobutylene, and polypropylene. In addition, solubilities were also determined for the preceding gases in polystyrene and polymethylmethacrylate. Other data were also obtained for neon, krypton, and monochlorodiflouromethane in various polymers.