The adiabatic cooling line has been defined for the assumed condition of constant liquid temperature, in connection with air-water system, till now, It cannot have any theoretically correct meaning for other systems, in which the liquid temperatures are not constant.
A modification for the definition is proposed in this reports. The new modified definition differs from the old one in point of quantity ratio of dry gas vs. sum of liquid and its vapor. The authors' proposition is to define its value as equal to a specified value, 1 vs. H_s, without any change in other points. Only the liquid temperature is assumed as equal to the wet bulb temperature of the gas.
By this new definition, we can treat the adiabatic cooling line in connection with all systems without any theoretical obstacle, and evaluate the error of the old one.
In this report, the present theoretical obstacles are discussed at first, and the new definition is proposed and illustrated. The equation of the new adiabatic cooling line is derived as follows: and for the approximate calculation, the following equation can be used, where, α=(t_w-t_s)/(t-t_s), which is assumed as constant in this case.
This newly defined adiabatic cooling line is equal to adiabatic saturation line in the same condition as defined above, which is verified in this report. They, however, are not equal to constant enthalpy line of the humid gas,
The proposed equations are applicable to any general problem, when t_w and H_s in the second term of the right hand formula are replaced by t_L and W₀ respectively. t_L is the liquid temperature, and W₀ is the sum of liquid and its vapor. It is necessary that both liquid and gas are in the complete convection excepting gas film.

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Absorption of carbon dioxide in aqueous solutions of sodium hydroxide was carried out in a 6" diameter packed column. Experimental results were treated in the similar manner as was used in our previous paper on the wetted-wall columns, except for the estimation of the effective contact area of gas and liquid.
Applying the Hatta's theory on chemical absorption to the packed columns, the over-all confficients, KG^a, may be exdressed by Eq. (1), where the values of β are theoretically given by Eq. (3). On the other hand, Eq. (2) is derived from the unsteady-state diffusion theory of Higbie or Matsuyama. These two theoretical relations, Eq. (2) and Eq. (3), are shown in Fig. 1. Using the experimental data of KG^a obtained for 1" Rasching rings (including 1" Berl saddles and 1/2" Raschig rings) and the film coefficients of physical absorption, kG^a and kL^a, calculated from the suitable experimental equations, the values of β are obtained from Eq. (1) and plotted against a_t√kA_mDL/kL^a (=X') in Fig. 1. It may be resonably assumed that the ratio of X to X'for the same β's corresponds to the effective fractional area, a/a_t, in the packed beds, From this point of view the plots of X/X' vs. L/_atμL are shown in Fig. 2-a and compared with the curve obtained by Fujita and Sakuma for the wetted frectional area, which is considered to be larger than the effective area due to the experimental method. The curve AB, 80% of Fujita-Sakuma curve, is used to calculate the average values of a/a_t and the calculated values of (a/at)X' (=X) vs. β are plotted in Fig. 3. Available data in the literature are also shown in Fig. 3. In conclution, it will be possible to estimate the over-all coefficients of absorption of carbon dioxide in aqueous solution of sodium hydroxide in packed columns, by employing Eq. (2) or (3), the curve AB in Fig. 2-a and the film coefficients of physical absorption.

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In the plastic, ceramic and other industries, screw extruders are often used for the purpose of forming materials. On the screw extruding process, many references have been published for viscous materials, but very few deal with plastic materials. And the extruders are designed and operated chiefly according to the experiential information. The object of this research is therefore to get the fundamental theory on the screw extruding process.
The problem was analysed under the assumption that the materials flow strictly according to the Bingham rheological equation. As results of the analysis, theoretical flow equations (9)-(8) were derived. Using the following three non-dimensional terms, these equations were simplified in very convenient forms as (9)-(18), and in the same way, power equations were derived as (23)-(26),
where η_pl: plastic viscosity
K_B: yield point
??_: peripheral velocity of the screw
ξ: pressure gradient
u: mean velocity of the material
h: depth of the screw.
Fig. 4 and 5 show the relations.
For example, by the aid of Fig. 4 and 5, and the B.O.A. Hedstrom's flow diagram, a definitecandition at the exit port, having a small circular hole die was determind.

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Angular velocity distribution, in the liquid in a cylindrical vessel agitated by a paddle, is similar to that of the socalled Rankine's compound vortex.
Therefore, around the agitator axis, there exists a region of liquid which circulates together with the agitator at the same speed as is shown in Fig. 2 by hatching. Its radius is designated as r₀ and varies with liquid viscosities over wide ranges.
As a result, it was revealed that the power requirements of turbines are related with those of paddles and they are equivalent in liquids of relatively low viscosities.
Secondly, it was found that the power requirements are also equivalent for paddles, if the products of the number of plates n_p and blade width b are equal, so far as liquids of relatively low viscosity are concerned.
From these two results, the power requirements of turbines and paddles having arbitrary number of blades are estimated from those of paddles with two blades.

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[in Japanese]

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[in Japanese]

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