An experimental investigation of the concentration fluctuation in a concurrent bubble column is carried out. The continuous stationary tracer injection technique is used and the followings are resulted. The auto-correlation function of the concentration fluctuation, one of the characteristics of the intensity of the time variation, is approximately exponential. The regularity of the concentration fluctuation decreases with the increase of the gas velocity and increases with the liquid velocity.
At some distance from the tracer injection point, the variance of the fluctuating concentration decreases exponentially with distance or mean passage time. The decreasing rate of the variance of the fluctuating concentration is increased with increasing the liquid velocity, the gas velocity and the hole number of the gas distributor.

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The dynamic method to determine intraparticle effective diffusion coefficients from breakthrough curves was applied to the adsorption at elevated pressures. Experiments was carried out on four kinds of adsorbents at a pressure range of 1-120 atm using ⁸⁵Kr in N₂ gas. Effective diffusion coefficients obtained were arranged by the parallel pore model and tortuosity factors of macro and micro pore were calculated.
Relative volatilities of adsorption of Kr from the mixed gas experimentally obtained were compared with calculated values by several prediction methods for mixed gas adsorption.

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The effect of the supplying method of the feed to the piston flow reactor on the yield, selectivity and distribution of the products was considered in mixed reactions which have a course like a lattice, such as the reactions from phenol and formaline to methylol phenols using NaOH as catalyst. If there is no limiting condition for the conversion, the maximum yield and selectivity are obtained by supplying all feed from the starting end of the reactor. If there is an upper limit for the conversion, the maximum yield and selectivity for the first intermediate products are obtained by supplying all feed from the starting end of the reactor but for the second intermediate products and the final products the maximum yield and selectivity are obtained by supplying feed with side flow in some cases.

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For the analysis of the overall rate of gas-liquid reactions, the conditions were discussed under which the mass transfer and chemical reaction processes should occur in series. The experimental data on the liquid-phase oxidation of benzaldehyde were analysed in terms of the consecutive model to separate the chemical and diffusional resistances.
As mechanisms of the liquid-phase oxidations are complex in general, the broader course of the reaction could not be explained by a simple combination of single reaction rate equations which was applicable only to the initial stage of the reaction. Therefore, from the engineering point of view, empirical rate equations were presented taking account of the influence of benzoic acid formed.

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The theoretical study has been carried out on the size determination of the homogeneous aerosol, consisted of spherical particles, by the Owl spectrometer which was constructed for rapid measurement of the number and position of the red bands of the scattering light from the aerosol particles.
From the discussions on the measurable particle size range and the refractive index dependence of the Owl spectrometer performance, it was found that the relations between the number of red bands and the particle diameter were affected considerably by the refractive index, especially in the range of diameter above 1 p, and the relations of the first angle, which is measured from the direction of propagation of the incident light, of red bands and the particle size were no longer unique in the range of particle diameter above a certain value given for a refractive index.
And, it seems to be necessary that the theoretical plots of angular position of the red bands as a function of the particle diameter have been prepared for a refractive index of the aerosol particles measured.

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The theoretical study has been carried on the size determination of the polydisperse aerosol, consisted of the spherical particles, by the Owl spectrometer. Red-green intensity ratios of the vertically polarized scattering light were calculated from Mic theory as a function of the logarithm of geometric standard deviation of the aerosol particles, whose size distribution was assumed to be lognormal, with respect to several values of the geometric mean of particle diameters and several values of the refractive index of the particle.
The larger dispersion of aerosol particles led the lower the peak value of red-green ratio, and the more difficult to detect the red bands of scattering light by Owl. The critical value with dispersion, at which the red band was not detected by Owl, was found about 0.05-0.12 p as a product of the logarithm of geometric standard deviation and the geometric mean of particle diameters, and should seem not to differ by variance of the refractive index of the particle.

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Inertial collection efficiencies of aerosol particles by a sphere are obtained theoretically and experimentally for the Reynolds number range of 5 to 200. The theoretical efficiency curves are calculated assuming the flow field obtained by boundary layer theory or by Jenson's numerical solutions. Experiments are carried out by using 2.68μ monosize polyvinyltoluene latex particles, and particles captured on the target sphere are observed by microscope. The efficiencies are in fairly good agreement with the theoretical ones.

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