KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 11 , Issue 2
Showing 1-20 articles out of 20 articles from the selected issue
  • Keiichi Tsuto, Mutsuo Nakayama, Shigeyasu Imamura
    1985 Volume 11 Issue 2 Pages 127-133
    Published: March 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Effective gas-liquid interfacial area in a rising-film tubular reactor was experimentally measured. The flow pattern in the reactor was in the region of thin-film annular flow, where liquid holdup was especially very small. The effects of liquid physical properties such as viscosity and surface tension on the liquid-film characteristics were also examined. Effective gas-liquid interfacial area per unit reactor volume, α (m2/m3-reactor volume), was correlated as a function of the energy dissipation term, ε (kPa/s), in which all effects of operational conditions, reactor diameter and fluid properties are included. That is, α=57ε0.412 where ε is described by the terms, (pressure drop per unit length) × (gas velocity), and the ranges examined in this work were 1.1-17.5 kPa/m and 15-50 m/s respectively. The range of liquid holdup examined was 2-6 %.
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  • Hidetoshi Mori, Norio Kimura, Tsutomu Aragaki, Shigeki Toyama, Mompei ...
    1985 Volume 11 Issue 2 Pages 134-139
    Published: March 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    To obtain a simplified method for predicting the initial collection efficiency of granular bed filters in the low-velocity region where diffusion is predominant, an approximate expression representing the collection efficiency of a single sphere is proposed. The expression is based on the Kuwabara-Happel cell model for multiple spheres and takes into account gravity as well as diffusion and interception. The gravity effect was verified experimentally by comparing filter penetration for downflow with that for upflow, and the results were correlated by a sedimentation parameter.
    It is demonstrated that the single-sphere collection efficiency of granular beds can be well evaluated as a sum of diffusion-interception efficiency and sedimentation efficiency presented in this paper. Satisfactory agreement between calculations and experiments are confirmed for particle collection by Granular beds of spheres. under the conditions of filtration velocity, us=0.2-20cm/s, aerosol particle diameter, dp =0.31-2.0μm and packed granule diameter, dc=88-4300μm
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  • Toshio Ohtani, Atsuo Watanabe, Chimaki Hoshino, Shoji Kimura
    1985 Volume 11 Issue 2 Pages 140-146
    Published: March 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    There have been few studies of the dynamic membrane formed on a porous ceramic tube for the purpose of ultra filtration. The results of a study of the possibility of such a dynamic membrane for ultra filtration are described in this paper.
    We found that a solution of ovalbumin, a kind of protein, formed an ultra filtration membrane and also that flux and cut-off molecular weight were controlled by the ovalbumin concentration. Because the mass transfer coefficients determined by the velocity variation method agreed very well with the Le veque correlations, the effect of concentration polarization of the ovalbumin on porous ceramic tube has been corrected. Consequently, membranes having various observed rejections showed the same true rejection after computation by this correlation.
    The dynamic membrane formed by ovalbumin had sufficiently good performance as a ultra filtration membrane.
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  • Koichi Okumura, Ken-ichi Suga
    1985 Volume 11 Issue 2 Pages 147-154
    Published: March 10, 1985
    Released: November 12, 2009
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    A kinetic model for the hydrolysis of amylopectin by glucoamylase was developed and expressed mathematically. A simple structure model of amylopectin based on the cluster model was proposed from structural data obtained experimentally. The kinetic model was based on Michaelis-Menten type kinetics for exowise attack of the non-reducing end of amylopectin, taking account of the degradation pattern of the branch point. The rate equations were presented from the above simple model structure and kinetic model. Rate parameters (Michaelis constant Km, i and molecular activity k0, i) of the rate equations were quantified by empirical equations based on results obtained from the hydrolysis of amylose by glucoamylase.
    The experimental data of the conversion and branch point (α-1, 6-glucosidic linkage) concentration during the degradation of amylopectin showed good agreement with the results calculated from the rate equations.
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  • Mitsuo Takahashi, Chiaki Yokoyama, Shinji Takahashi
    1985 Volume 11 Issue 2 Pages 155-161
    Published: March 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Viscosities of R113, R114 and R115 were measured, using an oscillating-disk viscometer at 273.15-473.15 K and in the pressure range up to 7 MPa. Experimental viscosities were represented by equations as a function of temperature and density. The force constants for the Lennard-Jones 12-6 potential were determined from the viscosities at atmospheric pressure and various temperatures as follows.
    R113 : ε/k=240.1 K, σ=0.6521 nm.
    R114 : ε/k=233.6 K, σ=0.6146 nm.
    R115 : ε/k=201.9 K, σ=0.5876 nm.
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  • Mompei Shirato, Toshiro Murase, Haruo Yamazaki, Masashi Iwata, Masato ...
    1985 Volume 11 Issue 2 Pages 162-167
    Published: March 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Dynamic filtration with little or no cake formation can be accomplished by applying an intensive liquid shear to filter medium. Two-dimensional flow behaviour associated with the rotation of a grooved disc enclosed within a filter chamber was studied without permeation, using polymethylmethacrylate as a tracer particle.
    The liquid flow in the axial gap between the disc and medium comprises three regimes : the core and two different boundary layers. The rotating grooved disc significantly accelerates the radial and tangential flow velocity in those regimes. The effects on liquid velocity of the dimensions and rotation of grooves are evaluated in terms of the increase in the core-to-disc ratio K of tangential velocity. The K-value is empirically determined from the calculation of a newly defined factor (Re·a/l), thus providing a method for predicting the velocity profiles in the chamber. It is also shown that over a range of (Re·a/l) =2.5× 103 to 1.4 × 105 the pressure distribution on the medium can be favourably estimated on the basis of the ratio K.
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  • Takuji Shitara, Shigeru Matsumoto, Mutsumi Suzuki
    1985 Volume 11 Issue 2 Pages 168-174
    Published: March 10, 1985
    Released: November 12, 2009
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    Unsteady temperature distribution within laminated material is calculated by using a numerical Laplace inversion technique. This method can be applied to material consisting of up to 100 lamination layers and also to multicomponent laminates. The temperature distribution is much affected, especially in a short elapsed time, by the thermal properties of surface component, resulting in a quite different distribution from that within homogeneous material. The apparent thermal diffusivity of such material is not uniquely determined because it depends on the number of components as well as observation time.
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  • Yukio Fukubayashi, Eiichi Kunugita, Hiroaki Yasuoka, Eiji Nakanishi
    1985 Volume 11 Issue 2 Pages 175-179
    Published: March 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    In many continuous processes, it is often found that plant performance deteriorates during the course of operation. A stage is eventually reached when further deterioration in plant performance is no longer tolerable. This could be either due to economic reasons or product quality limitations. At this point, the operator is forced to shut down the plant and go through the process of reactivation. Plants employing such cyclic stepwise operation require some appropriate methodology to determine the optimum switching time between production and regeneration processes.
    In this study, an attempt has been made to maximize the productivity of such semicontinuous plants. Each process unit involved is separately modeled by a set of ordinary differential equations, and then the problem of finding the optimum switching time for maximizing the production rate is solved analytically. The proposed methodology has been applied to determine the optimum cyclic period of a plant which produces demineralized water, employing a fixed bed composed of a cation exchange resin (Amberlite IR 120B) and an anion exchange resin (Amberlite IRA 410).
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  • Mitsumasa Murakami
    1985 Volume 11 Issue 2 Pages 180-185
    Published: March 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A new method of multi-channel measurement of salt concentration is proposed on the basis of a microcomputer control technique for separation of electric resistivities on platinum probes which sense electrolytes.
    Using analog multiplexers, square-wave current is supplied to each of the probes in due order. The signal detected synchronously is amplified, peak-held, digitalized and stored on the 256-Kbyte RAM which is the outer memory of the microcomputer. The control program codes by machine language.
    This system has six following performance features : 32 channels, high-speed sampling of 100 μsec/channel (max.), response time of 50 psec, stability of ±0.15 %, accuracy of ±0.5% and wide range of salt concentration (50-1200 mg/l or 200-3500 mg/l NaCl).
    The outline of the data processing program codes by BASIC language and some useful graphs such as deviation graph of NaCl tracer and contour map of salt concentration can be obtained.
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  • Hidehiro Kamiya, Jun-ichiro Tsubaki, Genji Jimbo
    1985 Volume 11 Issue 2 Pages 186-192
    Published: March 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    To study more quantitatively the fatigue failure phenomenon of powder beds, which was earlier discovered and reported by the authors, this study was an attempt to obtain the relation between repeated tensile stress and fatigue life, which is usually represented by S-N relation, in a wide range of the repeating number N. Experiments were carried out by using vibration to exert dynamic repeated tensile load on the powder bed, with a vertically vibrating cell and a horizontally splitting cell. The frequency of vibration used was in the region of 5-300 Hz, and Kanto loam powder (JIS-11), fused alumina powder and lactose powder were used as samples.
    The results obtained are analyzed statistically and quantitatively concerning the distribution of fatigue failure life.
    It is found that within the limited range of the number of repeated stress less than 106, the existence of a lower limit of tensile stress (endurance limit) where the powder bed fails is confirmed at a stress ratio of the order of 0.7. The distribution of fatigue life is expressed by a Weibull distribution, and then it is shown quantitatively that the distribution of fatigue life of the powder bed is wide compared with other kinds of material, and it is suggested that the S-N relation of the powder bed obtained previously can be divided into two ranges, a sloping part and a horizontal part.
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  • Kenji Shimizu, Chie Endo, Noriaki Kubota, Toshikuni Yonemoto, Teiriki ...
    1985 Volume 11 Issue 2 Pages 193-197
    Published: March 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    This paper describes the importance of seed crystal pretreatment both in industrial batch crystallization and in experimental studies using seed crystals. Seed crystals, washed by different solvents or stored under different humidities for different periods, were quietly introduced into stagnant supersaturated solution to produce secondary nuclei by the initial breeding mechanism. By washing the seed crystal, the number of secondary nuclei was decreased. Fresh seed crystals, just after sieving operation, produced a large number of secondary nuclei, while other seed crystals, washed by 50 vol. % methanol aqueous solution, produced only about one-fifth the number of nuclei as did fresh seed crystals. Water-washedseed crystals produced no nuclei. By storing the seed crystals at high humidities for a long period, the number of secondary nuclei also decreased. When seed crystals were stored for long periods exceeding 3 days in 92 % humid air, the number of nuclei produced was only 1 %of that from fresh seed crystals. Microscopic observation of the seed crystals proved that these pretreatment effects were due to washing off or dissolution of microcrystallites on the surface of seed crystals.
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  • Tadashi Matsui, Yoshio Harano
    1985 Volume 11 Issue 2 Pages 198-202
    Published: March 10, 1985
    Released: November 12, 2009
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    The effect of agitation rate, Nr, on the metastable zone width, ΔTm, for unseeded aqueous solution of KBrO3 was measured at constant cooling rate, b, and analyzed by a non-isothermal technique proposed previously and the following results were obtained.
    Eq. (1) is useful in approaching the nucleation phenomena in agitated unseeded solution.
    In (b/V) =In (k2/Nobs) -In B-MTTs/ΔTm2 (1)
    MT=M3 (2)
    where V, B, Ts and M0 are the volume of sample solution, an empirical constant, the saturation temperature and a constant defined by the physical properties of solute, respectively.
    ΔTm is markedly affected by b and Nr. With increase in Nr, ΔTm decreases (Region I), increases (R. II) and then decreases (R. III), due to the variation of, not the surface energy, σ, but the frequency factor, k2.Some considerations hrere madeof these agitation effects.
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  • Masaharu Takao, Hiroshi Yamasaki, Yasuhiro Murakami
    1985 Volume 11 Issue 2 Pages 203-209
    Published: March 10, 1985
    Released: November 12, 2009
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    In an experimental system where a small quantity of liquid A was supplied to a large quantity of liquid B, experiments in both physical mixing and instantaneous reaction were conducted in the turbulent region and the mixing characteristics obtained by measuring local concentrations at seventy-two points in the vessel are compared. Firstly, the probability density distributions of concentrations for KCl tracer and the product were calculated and their changes with time are shown. Next, the probability density distributions of mixing times, which were defined as the times required to reach ±2 % deviation of local concentrations for KCl tracer and the product from the final mean concentrations, were calculated and the shapes of distribution, coefficients of variation and mean mixing times are compared. Further, the mean unreacted fraction for instantaneous reaction at any impeller speed is found to decrease faster than the degree of deviation Dd' and the degree of standard deviation √Is' that are normalized with the mean concentration, but become agreeable with the degree of deviation Dd that is normalized with the first-order absolute centered moment of concentration in the state of complete segregation after the mass balance of mean concentration in the vessel could be accurately measured. Therefore, Kappel's theory is concluded to hold in the turbulent region, even in the system where the volume fractions of liquids A and B are extremely different.
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  • Hidehiro Kamiya, Jun-ichiro Tsubaki, Genji Jimbo
    1985 Volume 11 Issue 2 Pages 210-216
    Published: March 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    To investigate the process of fatigue failure phenomenon of a powder bed, which was analyzed as the relation between repeated stress and fatigue life (S-N relation) by authors, the increasing process of displacement by loading with repeated tensile stress was analyzed.
    Experiments were carried out by using vibration to exert dynamic repeating tensile load on the powder bed with horizontally splitting cell. The frequencies of vibration used were 5 and 20 Hz, and Kanto loam powder (JIS Z8901 Test Dust No. 11), fused alumina powder and lactose powder were used as samples. It was found that the increasing process of displacement is divided into three sections, and an experimental equation, with which it can be used to estimate the fatigue failure life, is proposed. Further, the difference of the increasing process between the sloping part and horizontal part in the S-N relation proposed in the preceding report is characterized.
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  • Ryoichi Nagata, Akitaka Yamasaki, Hidekazu Koya, Shinichiro Gondo
    1985 Volume 11 Issue 2 Pages 217-222
    Published: March 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The decomposition of uric acid by uricase obtained from yeast was studied experimentally in pH 7.0 tris·borate buffer. The effects of allantoin and hydrogen peroxide on the decomposition and the decay of uricase activity were observed as well as the decomposition rates. Experiments in the decomposition of uric acid were carried out at temperatures of 15, 25 and 35°C, at uric acid initial concentrations of 1.0×10-3, 3.0×10-3, and 5.0×10-3 mg/cm3 and at uricase initial concentrations of 3.7×10-4-7.4×10-3 mg/cm3, where the decomposition of uric acid were in the range of about 34-92 %.
    The results are summarized as follows :
    1) Allantoin and hydrogen peroxide showed no inhibition effect on the decomposition of uric acid. 2) The decay of uricase activity was expressed in fractional or linear form. 3) Parameters in the decomposition rate equation containing the term of enzyme activity decay were estimated by using observed data, and the time variation of uric acid concentration was simulated with these parameters to show good agreement with observed results.
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  • Mitsuo Kamiwano, Fumio Saito, Hirotoshi Tanaka, Hiroyoshi Toriyabe, No ...
    1985 Volume 11 Issue 2 Pages 223-245
    Published: March 10, 1985
    Released: November 12, 2009
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  • 1985 Volume 11 Issue 2 Pages 245a
    Published: 1985
    Released: November 22, 2010
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  • 1985 Volume 11 Issue 2 Pages 245b
    Published: 1985
    Released: November 22, 2010
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  • 1985 Volume 11 Issue 2 Pages 245c
    Published: 1985
    Released: November 22, 2010
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  • 1985 Volume 11 Issue 2 Pages 245d
    Published: 1985
    Released: November 22, 2010
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