In the prediction of the vapor composition in vapor-liquid equilibrium of the binary system A-B, using boiling points or total pressures as the only equilibrium data, as the concentration of A increases, the nonideality contribution of A changes, not suddenly but gradually, from total, 16/17, 6/7, 4/5, 3/4, 2/3, 1/2... to zero. In addition to the gradual nonideality contribution, by suitable addition of ΔXint to Xint and changing the distribution of the nonideality contribution with the addition, the prediction of vapor composition for systems in which the vapor pressure ratio (PA/PB is much greater than two has become possible. Some forty-two binary systems consisting of Hydrocarbon-Hydrocarbon, Alcohol-Water, Hydrocarbon-Alcohol, and other miscellaneous combinations have been studied and an improved, concise prediction method is illustrated.

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Solubilities of carbon dioxide, ethylene and acetylene in some aqueous solutions containing a single salt or mixed salts are measured at I atm and 25°C by the gas volumetric method. A method of estimating gas solubility in aqueous solutions of mixed salts from the data of aqueous solutions of each salt is discussed, i.e. an additive rule for salting-out parameters is confirmed and, using this rule, solubility data in such aqueous salt solutions can be estimated from the empirical values proposed by Onda et al.
The estimated results agree well with experimental results within 2.4% as the standard deviation and they are more reliable than those of van Krevelen et al.

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Binary interdiffusion coefficients for twenty pairs were determined using gas chromatography at several temperatures higher than room temperature under I atm. Of four equations used to predict the diffusion coefficients the correlation of Fuller, Schettler and Giddings gave the smallest arithmetic deviation of 5% of predicted values from experimental data.

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The second virial coefficient for pure compound is correlated as a power series of the reduced temperature. The three parameters of the equation were calculated by computer and in the calculations of second virial coefficients with all the substances investigated the errors were less than 5% over a substantially wide temperature range.
According to an assumed combination rule, the second virial cross coefficients are considered briefly.
With these second virial coefficients, an effect of the vapor-phase imperfection on vapor-liquid equilibrium has been investigated.

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Quaternary vapor-liquid equilibria with ester if) cation have been formulated mathematically. First, activity coefficients have been related to liquid compositions with polynomial equations derived from the Mar gules model, and second, the parameters Bt defined in an equation of the vapor-liquid equilibrium ratio with esterification reported previously have been represented by polynomials. Both correlations are adequate to describe the behavior of the given systems.
Vapor-liquid equilibrium with reaction of the system acetic acid-ethanol-water-ethyl acetate was predicted from Wilson''s parameters obtained from binary system data only. Association equilibrium constants of dimerization and trimerization in acetic acid vapor were used to calculate modified activity coefficients, and Wilson''s parameters were determined from six binary data. The agreement of the calculated and experimental data may be considered satisfactory for the practical use to design multicomponent distillation column reactors.

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To evaluate the Wilson parameters from the activity coefficients in an infinitely dilute binary solution, nomographs have been prepared which show the following features of the Wilson equation.
i. In a system of positive deviations from ideal behaviour only I set of parameters exists.
ii. In a system of negative deviations, I through 3 sets of parameters satisfy the Wilson equation. By these nomographs, the authors have evaluated the Wilson parameters for the acetone-chloroform system, which give a good representation of the data.

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Isobaric vapor-liquid equilibrium data at 76Omm of Hg were determined for the ternary methyl acetate-2-propanol-benzene system and isothermal equilibrium data at 50°C were obtained for the ternary system methyl acetate-chloroform-benzene and for its binary systems, methyl acetate-chloroform, methyl acetate-benzene, and chloroform-benzene, using a Jones still. The Wilson and NRTL equations were successfully applied for the correlation of the liquid-phase activity coefficient and for the prediction of ternary equilibrium data.

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Simple but systematic expressions for eddy viscosity based on the available experimental results are presented and the universal velocity profile is obtained from the eddy viscosity distribution. The present analysis takes account of the Reynolds number effect on the eddy viscosity.
The friction factor based on the universal velocity profile was in good agreement with the Blasius formula, which was derived from the (1/7)-power law of the velocity profile, and was sepresented precisely by the Prandtls universal law of friction.

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Appropriate equations are solved for the transfer of radiant energy from a heated cylindrical enclosure having walls that are either black or gray to an absorbing gas or a gas containing black particles. The resulting expressions are shown to be valid by experiments utilizing carbon black aerosols of several concentrations.

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A new method for measuring instantaneous and local mass transfer rate is established by observing a rate of conductive heat transfer inside a solid with mass transfer by means of a thin-film resistance thermometer. The principle of the method, the instruments and the procedure are described. To verify the measuring method experimentally, we measured the rate of vaporization of an organic solvent from a porous flat plate surface into an air stream. The experimental results are in good agreement with the previously reported results in the range of the Reynolds number Re= 10³4×10⁴ for laminar and turbulent boundary layers. The experimental error is estimated to be at most about ±10% and the response time to be about 10μ sec. This method may contribute a great deal to the analysis of various instantaneous phenomena in unsteady and transient states as well as in steady states.

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The rate of ionic mass transfer at the limiting current density was measured in two-dimensional flows both laminar and turbulent, through a channel between a pair of ion-exchange membranes. The results obtained were independent of the properties of the membranes, because the mass transfer rate at the limiting current density was mainly controlled by the transport process through the boundary layers in the desalting cell.
For laminar flow, the experimental results showed good agreement with those of numerical analysis, in which the rate was assumed to be controlled by the boundary layers produced near the membrane surfaces. For turbulent flow, the analytical results were also brought into good agreement with the experimental results, by introducing a new concept of the "eddy migration coefficient", ε_φ, and by putting εφ≈0.0086(∈M/V>)^1.0. ∈_M is the eddy diffusivity for momentum and v is the kinematic viscosity.
According to these results, the local electric conductivity in an intensely agitatd fluid may be greater than that in a stationary solution by 5 to 10%.

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A calculation method is presented to estimate the temperature and the concentration distribution in a catalyst packed bed by finite difference approximation and by use of the local effectiveness factor, taking into consideration the external and internal transport resistance to catalyst particles.
The method is applied to the hydrogenation of ethylene and to the oxidation of sulfur dioxide, and is compared with experimental results by us and by Schuler et al.

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The (T, X_A) reaction diagram is proposed for non-isothermal analyses of reversible solid-gas reactions based on the unreacted-core shrinking model. When an equilibrium curve, a reaction curve, and a tie-line are drawn on this diagram, the temperature and concentration at the reaction surface, which play an important role in solid-gas reactions but which have so far been calculated only by numerical computations, can easily be obtained. The reaction diagram can also elucidate how the three ratedetermining steps of chemical reaction, mass transfer, and heat transfer are interrelated in reversible processes.

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Drying and thermal dehydration of gypsum in the shape of thick circular plate and sphere ware investigated, especially by using a fluidized bed to reduce the film resistance for heat transfer.
Analyzing the change of temperature profile within the gypsum sample and applying the reaction diagram proposed in the previous paper which is based on the non-isothermal analysis of unreacted-core model, the authors could successfully clarify how the transport rates of diffusion and heat transfer affect the kinetic behavior of the process. The reaction path could be drawn with temperatureconcentration coordinates on the reaction diagram.
The reverse hydration reaction was also studied, and the reaction diagram is also verified to be very useful in this process.

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The selectivity change in a consecutive reactions system brought about by the deactivation of a catalyst is studied from the viewpoint of the intraparticle diffusion effect. First, by analysis based upon three types of simplified deactivation model, it is shown that the deactivation mechanism inside a catalyst particle exerts a strong influence upon the tendency of the selectivity change with deactivation through the time history of the distribution pattern of rate constants. Next, the deactivation of a nickel catalyst for the hydrogenation of acetylene is experimentally observed. The observed relations of the selectivity to the degree of deactivation well accord with one of the three models. In a detailed analysis, the micro-macro pore model proposed in previous papers^{1, 2)}, by the authors is used as the basis of this catalytic system. The mode! is proved to be reasonable for the deactivation process also.

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The catalytic air oxidation of geranioi was carried out in packed-fluidized beds. Copper gauze of various structures were packed as catalysts and glass beads or quartz sand were fluidized through the voidage of packed catalyst to make the reaction isothermal. It was found that a larger value of (u_f - u_mf)/u_mf, smaller diameter of unit packed space and considerably larger fluidized particles tend to improve the reactor efficiency. A two-phase model was applied to interpret the experimental results.

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The electrification of spherical Pyrex beads rolling down an inclined Pyrex tube was studied with respect to its dependence upon time and humidity of the air. The time variables were the time spent by each bead in the tube, the time between successive beads in a lot of IOO beads, and the number of repeated runs of the lot over a period of several weeks. The data are in agreement with electrochemical electrification by oxidation-reduction exchange with the atmosphere, the kinetics of which is treated with respect to the measured quantities.

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On the basis of wall roughness, a simple model is presented to explain the irregular bouncing phenomena of particles in pneumatic conveying. By introducing a random factor to the model, a pneumatic transport process was simulated by Monte Carlo method.
The model could fairly well account for the concentration and velocity distribution and the rate of revolution of particles. Even very small degree of roughness was found to have a great influence upon the behaviour of particles.

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Studies were made of the de-entrainment efficiency of an 8Omm-diameter sieve plate column for the steam-water system. Variables studied were superficial steam velocities from 22.2 to III cm/sec, reflux ratios from O. I to 3.O and plate spacing from IO to 4Ocm. It was found that some of the droplets formed on the n-th tray and carried up through the n+l-th tray at a ratio f₁ were carried up again through the n+2-th tray at a considerably greater ratio f₂, and some of these droplets carried up through the two trays were carried up again and again through the n + 3-th tray at a slightly greater ratio f₃ than f₂, which seriously impaired the efficiency of the plate column. The maximum values of decontamination factors DF₁, DF₂, and DF₃ obtained were nearly lO², lO³ and lO⁴ respectively.

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An experimental equation to estimate power consumption in the mixing of plastic fluids was derived. For ribbon, anchor, turbine and paddle mixers, the following equation was obtained.
Np = β(Re")^-1 + aNy + 1
where Ny (= τ_y/ρn²d²) is a non-dimensional power number for the yield stress and a is a constant and can be calculated for simple mixers using the following equations.
Fnorizontal = 0.58τ_y, Fvertical = 2.81ry
For turbine and paddle mixers, a drastic transition state was observed between laminar and turbulent regions. In the transition region the periodical generation and disappearance of vortex was observed and the effect was explained by the periodic power consumption of the mixers.

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Experimental studies of the behavior of multi-drops in a drop-layer are carried out to show how to determine the stability of a drop-layer and to compare its stability with that of a single drop at a plane liquid-liquid interface. The stability of drops in a drop-layer is defined by the average time that drops can remain in the layer, and in most cases is almost independent of the volume of drops arriving at the layer. No large difference is seen between the stabilities of a single drop and of multi-drops in a layer in the absence of stabilizing agents, but the stability of drops in a layer is far less than that of a single drop in the presence of stabilizing agents. The relation between stability and concentration of stabilizing agents is similar to that between interfacial pressure and concentration in the cases of both a single drop and of multi-drops in a layer.

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A sufficient condition for the existence of a unique and stable equilibrium state of an adiabatic tubular reactor with recycle is derived from the necessary and sufficient condition for local stability presented in the previous paper¹⁴⁾. Furthermore, the sufficient condition is reduced to relations between recycle ratio, a, and mixing parameter, PeB. This condition requires only simple algebraic calculations to obtain the regions of existence of a unique and stable equilibrium state instead of iterative numerical integrations required in searching the regions where the necessary and sufficient condition is satisfied.
It is also shown that this condition contains the sufficient condition for the existence of a unique and stable equilibrium state of an adiabatic tubular reactor without recycle, presented by Luss and Amundson¹¹⁾, as a special case when a=O.

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The short-cut method of Redlich-Kister was applied to determine the critical locus of forty binary mixtures by adopting the BWR equation which was used to calculate the limiting slopes. This method was shown to be very useful for both critical temperatures and pressures. When critical volumes of components concerned are greatly different, the discrepancy between prediction and experiment becomes significant for critical pressures. In this case, the extent of agreement was successfully improved by introducing the correction factor, m, into the BWR equation.

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The rate of surface renewal, defined by the ratio v_λ/λ₁ at the clean surface of isotropic turbulent liquid flow is highest for the smallest eddies with size λ₀ in the inertial subrange, where λ is the size of eddies and V_λ the fluctuating velocity. The eddies smaller than λ₀ are also shown to have a renewal rate the same as λ₀, thus indicating that the maximum possible liquid film coefficient of mass transfer is given by the equation reported previously for λ₀ New form of surface age distribution function at the clean surface of isotropic turbulent liquid is presented.

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A chart to assess the performance of classification or separation is herein proposed. The fact that this chart includes two parameters means the qualities of fine and coarse products are indicated at the same time. The weight fractions and quite a few classification efficiencies previously proposed can be figured out by using the classification efficiency chart.

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An approximate equation for the drag coefficient of spherical particles is proposed in the form of a quadratic equation in logarithmic co-ordinates. The constants of the equation have been determined by the least square method from experimental values⁵⁾. This equation gives better agreement with experimental values than the equations proposed previously by other authors. The constants of the equation and the comparison of its accuracy are summarized in Tables I and 2. This equation is valid even at Reynolds numbers between O and 70, 000, the standard deviation of the relative error being 5%.

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On the basis of a one-dimensional dispersion model, which was applied by Imafuku et al. to interpret the behavior of suspended solid particles in a bubble column, a procedure for obtaining the age distribution and the spatial age distribution of the particles in a continuously operating bubble column was developed.

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In the previous report³⁾ the method of moment was employed to solve the basic differential equation of forced expression. No explanation, however, was given as to the validity of using the larger root β for the non-dimensional critical time θ_Cri.
It is shown in this complementary report that theoretically the value of ft is restricted to the larger root of Eq. (17)³⁾ with the range of o Some comments on the diffusion process with different boundary conditions are also given.

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