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Sachio Okayasu, Masaki Katayama, Shigeyori Miyashiro
1995 Volume 21 Issue 5 Pages
847-852
Published: September 10, 1995
Released on J-STAGE: February 19, 2010
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Aiming for stable operation and rationalization of a fermentation plant, a near-infrared analyser was introduced into the on-line analysing system of the fermentation process.
An on-line sampling system with a defoaming apparatus was applied to a fermenter in a commercial scale plant. A new efficient method for obtaining highly accurate calibration curves of the near-infrared analyser was presented. The established method for on-line determination of the main components in the fermentation medium for amino acid production was applied to a real-time measurement system in a commercial fermentation plant. The pattern of sugar concentration change was successfully obtained on a real-time basis.
The system was partially incorporated into operation control, even if there was room for improvement of analytical accuracy in response to raw material differences in each lot.
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Munehiro Yamaguchi, Sogo Sayama, Hirokazu Yoneda, Kin-ya Iwamoto, Mits ...
1995 Volume 21 Issue 5 Pages
853-858
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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Heat storage-type floor heating by hot water from a heat pump driven 8 hrs by night electricity was studied. The phase change material (PCM) used for heat storage was Na
2SO
4·10H
2O package. Properties of the PCM are; melting point 32°C, solidification point 30°C, heat storage 43.0 W ·h/kg (Δ
T=10°C). The floor heating room was a 40 m
2, and without window, Na
2SO
4· 10H
2O package was used as a phase change material for heat storage. Hot water panels laid under PCM packages (26 m
2) were placed on a stage 1.2 m above the floor. The total heat storage was 28.5 kW. The heat pump was operated in an 8 hrs ON-16 hrs OFF cycle so that three times the heat extraction was needed as compared with continuous operation. For this reason, a wet film type vertical tube with a CFC flashing pump at the bottom was developed. From experimental results, the thermal balance of the system was calculated and the applicability for practical use was discussed.
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Kenji Kawasaki, Akira Matsuda
1995 Volume 21 Issue 5 Pages
859-865
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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The effects of dissolved solid concentration on the freezing and thawing treatment of excess activated sludge were investigated in this paper. The floc properties and the solid-liquid separation characteristics of the unfrozen and frozen excess activated sludges in which various amount of sodium chloride (NaCl) were dissolved were measured. The moving and concentrating characteristics of suspended solids during the freezing process deteriorated with increasing NaCl concentration, and the size and density of the sludge floc produced became smaller. Settling and filtration experiments showed that the settling and filtration characteristics of the sludge under 0.2 wt% NaCl were remarkably improved by freezing and thawing treatment, and did not depend on NaCl concentration. However, if the NaCl concentration was over 0.2 wt%, the improvement of the settling and filtration characteristics decreased greatly. Therefore, for excess activated sludge in which the dissolved solid concentration is over 0.2 wt%, it is desirable that the freezing and thawing treatment should be done after washing the sludge with water to decrease its concentration.
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Toshitaka Funazukuri, Hiromasa Takahashi, Ken Miyajima, Noriaki Wakao
1995 Volume 21 Issue 5 Pages
866-870
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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Kraft pulp was bleached with an aqueous solution of hydrogen peroxide and sodium hydroxide at various concentrations in a batch reactor. The effects of H
2O
2 and NaOH concentrations on the brightness and the kappa number of the bleached pulp were studied. The bleaching rate, in terms of the increase in rate of brightness, at H
2O
2 of 0.039 mol/l and NaOH of 0.066 mol/l was expressed with first order reaction kinetics with an activation energy of 29.4 kJ/mol.
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Keisuke Fukui
1995 Volume 21 Issue 5 Pages
871-878
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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The characteristics of periodic unsteady flow in an expanded pipe in which mass flow rate changes sinusoidally were investigated through flow visualization and numerical analysis. The flow patterns at the expansion were classified into four types; three flow patterns of stable two-dimensional flow and another flow pattern of unstable three-dimensional flow at the transition to turbulence. The effects of frequency and two Reynolds numbers based on time-averaged and amplitude flow rate upon the flow characteristics were discussed. It was found that a specific frequency of 1.5 Hz existed in the present study. This frequency contributed sensitively to flow pattern and flow stability. The fine structure of the flow at the expansion were elucidated from numerical predictions and flow-visualized photographs. These results clearly showed the details of the occurrence and dissipation processes of separated vortices and vortex-trajectory at the expansion. The relationships of flow structure and flow stability were also discussed.
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Masahiro Hasegawa, Mitsumasa Kimata, Shoichiro Ishibashi, Yoshiteru Ka ...
1995 Volume 21 Issue 5 Pages
879-885
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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Silica particles of micron size were prepared by hydrolysis and condensation of tetraethyl orthosilicate (TEOS) with silica seed particles synthesized by Stöber's method. Monodisperse silica particles larger than 1μm in diameter were found to be produced by controlling the total surface area of seed particles. The final particle size in this seed growth technique could be predicted if an apparent rate constant of hydrolysis was measured. The preparation of monodisperse composite particles of silica-titania was also attempted by the hydrolysis of titanium tetraisopropoxide (TTIP) with silica seed particles. It was found the monodisperse composite particles of silica-titania were obtained by continuous addition of water.
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Shinichi Yuu, Toshihiko Umekage, Shigeru Sakata
1995 Volume 21 Issue 5 Pages
886-895
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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The three-dimensional flow field of high Reynolds number (
Re=1500) circular Couette flow was numerically simulated by a direct numerical simulation. We calculated instantaneous velocity vector diagrams and flow characteristics (mean velocity distributions, turbulent intensity distributions and auto-correlation coefficients) in a circular Couette flow developed quasi-steady state, and compared them with experimental data. Calculated results agree fairly well with the experimental data obtained by using a Laser Doppler Velocimeter (LDV). These results show that direct numerical simulation by using a third-order upstream finite-difference scheme for the convection term whose computational cell size is roughly two times the averaged Kolmogorov micro-scale of the flow predicts the flow fields of high Reynolds number circular Couette flows in which turbulent flows exist well.
Since tangential velocities near the vortex (cell) boundaries are greatly changed by fluctuations of flow patterns, the intensities become larger than the θ-
Z plane average. Both high and low velocity regions originating in the inner and the outer cylinders exist in the central region of γ-θ plane. So the maximum fluctuating velocities in the central region appear as two times the velocity of those in the inner and outer cylinder surface regions. Auto-correlation coefficients indicate that the flow field at
Re=1500 has both periodic and turbulent characteristics.
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Hisao Makino, Hirofumi Tsuji, Masayoshi Kimoto, Hideto Yoshida, Koichi ...
1995 Volume 21 Issue 5 Pages
896-903
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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It is very important to measure particle size distributions in flue gas. In conventional methods, it is necessary to use a complicated classifier like the Andersen Stack Sampler or particle size measuring instruments after an isokinetic sampling in order to get the particle size distribution. On the other hand, the new measurement method utilizes sampling error due to the anisokinetic sampling as a classification method. When the sampling velocity is not equal to the main flow velocity, the ratio of the main flow velocity to the sampling velocity has a linear relation with the measured concentration and also the ratio of the measured concentration to the actual concentration. As the slope of this line is determined by the particle size distribution, it is possible to estimate the particle size distribution. This method has been experimentally proven for several kinds of particles from 0.5 to 40μm in median diameter, and the results are in good agreement with size distributions measured by conventional methods.
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Ichiro Naruse, Kiyoshi Nishimura, Kazutomo Ohtake, Teisuke Kawabe
1995 Volume 21 Issue 5 Pages
904-909
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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Desulfurization characteristics of shells (scallop (Hotate), short-necked clam (Asari) and oyster (Kaki)) were studied by using a thermobalance and compared to the results obtained by limestones (Tsukumi-and Funao-Brand) currently used as desulfurizers. First, such physical and chemical properties of these samples as specific surface area, pore size distribution and chemical constituents are identified. In the thermobalance experiments the calcination temperature, the rate of temperature increase to this point, and the desulfurizing temperature are changed, and the particle diameter is fixed in the range of 297-420 μm. After calcination is carried out in N
2 gas, the sample is sulfurized in SO
2+O
2 gas in N
2 balance. The cross-sectional sulfur distribution within the reacted particle is measured by a two-dimensional XMA. Results show there is no correlation between the desulfurization efficiency and the specific surface area. However the desulfurization efficiency depends on the pore size distribution. The desulfurization efficiency of shells becomes higher than that of limestones. In the case of limestone, sulfur is only trapped near the particle surface since the micro-pores are plugged due to CaSO
4. In the case of the shells, however, the sulfur is distributed over the whole body.
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Magnetic buoyancy and restraint of gas-mixing
Kazunari Ohgaki, Koji Matsumura
1995 Volume 21 Issue 5 Pages
910-915
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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Combustion phenomena under slight gravity and magnetic field, which are quite important subjects for science, energy and space chemical engineering, have been reported recently. In the present study, the magnetic effect on gaseous mixtures containing oxygen of paramagnetic body is investigated under a magnetic field of 1T. The magnetic-buoyancy and restraint of gas-mixing process are observed for a lump of mixtures, while the molecular diffusibility is not controlled under such low magnetic flux density.
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Tadaaki Nishiki, Akinori Muto, Takeshi Kataoka
1995 Volume 21 Issue 5 Pages
916-922
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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Equilibria and rates in backward extraction of lysozyme from AOT/isooctane reversed micellar phase to aqueous KCl solutions were investigated by changing temperature and by adding isopropanol to the aqueous stripping phase. As the temperature rose in the range of 288 to 313K, the percent backward extraction decreased slightly, but the rate of release of lysozyme at the interface by which the backward extraction rate is controlled increased. By the addition of isopropanol to the aqueous stripping phase, favorable aqueous conditions (pH, KCl concentration) for backward extraction could be extended, and the rate of release could also be accelerated remarkably.
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Toshiaki Oda, Naotake Katoh
1995 Volume 21 Issue 5 Pages
923-928
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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Frequency response of a continuous cooling crystallizer is examined both by simulation and by experiment using a succinic acid system. The input and output of this process are cooling temperature and crystal production rate, respectively.
Simulation and experimental results showed that sustained oscillation of a crystallizer was strongly dependent on amplitude and angular frequency of the cooling temperature input. This fact suggests the possibility of reduction and prevention of sustained oscillation using the cooling temperature with appropriate amplitude and angular frequency.
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Yoshikazu Miyake, Tetsuya Muta, Katsuya Ishizuka, Tomoyuki Shiraishi, ...
1995 Volume 21 Issue 5 Pages
929-935
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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The reduction of chloroauric acid with acetone-dicarboxylic acid in the aqueous phase was measured by a spectrophotometer. The rate of decrease in chloroauric acid concentration was obtained from the time courses of absorbance at 210 nm. The rate was proportional to both concentrations of chloroauric acid and acetone-dicarboxylic acid. As the activation energy of the rate constant was obtained as -21.2 kJ/mol, the process was deduced to be a nucleation process. The wave length of maximum absorbance of the colloidal gold formed was 530 nm. The time cource of the absorbance at 530 nm had an induction time and was expressed by a sigmoidal curve. The induction period decreased with concentrations of both chloroauric acid and acetone-dicarboxylic acid and with temperature. The activation energy of the induction period was obtained as 85 kJ/mol. Growth of colloidal gold occurs in this induction period.
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Ryuichi Egashira, Junjiro Kawasaki
1995 Volume 21 Issue 5 Pages
936-943
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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The separation of a binary model mixture of benzene and hexane by an emulsion liquid membrane process was calculated with a correlation of the emulsion liquid membrane permeation coefficient. The process consisted of a liquid membrane permeator, a countercurrent packed column with a reflux, and three distillators for the recovery of solvent from the extract and raffinate phases, and for enriching benzene in the permeate. A high yield of high purity benzene, and a high purity hexane could be obtained with the permeator and the two solvent recovery distillators. The size of the permeator and the energy required for the separation were reduced by introducing the benzene enriching distillator. The energy require ment for solvent recovery from the extract phase occupied the largest part of the entire process. The energies for solvent recovery from the raffinate and for enriching benzene were relatively lower. Recycling of a stream in the process and the appropriate means of reflux to the permeator allowed the size of the permeator and the energy requirement for the process to be decreased.
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Tatsumi Yamamoto, Ken-ichi Nishii, Hiroyuki Kawasaki, Hisaya Tanaka
1995 Volume 21 Issue 5 Pages
944-947
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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Continuous emulsification was carried out by jetting into a small mixing chamber with two parallel injection needles (inner diameter
dN= 0.3, 0.5 and 0.7mm) at 303 K. Kerosene or
n-heptane were employed as the continuous phase, and water was used as the dispersed phase. Nonionic surfactant (Span80) was dissolved in the organic phase. Aqueous droplet diameters in emulsion were measured from a micro-photograph. Log-normal distribution with upper-limit applied to the droplet size distribution. The maximum droplet diameter (
dmax) was 2.3 times the Sauter diameter (
d32). The
d32 value was inversely proportional to the velocity (
U) of liquid flow issued from the injection needle.
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Yoshihito Kato, Setsuo Hiraoka, Yutaka Tada, Takeshi Shirota, Seung-Ta ...
1995 Volume 21 Issue 5 Pages
948-952
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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The critical circulating frequency and the power consumption for complete suspension of particles, based on the definition of Zwietering, were measured in a shaking vessel containing a solid-liquid system. The critical frequency was correlated by the equation from Baldi's particle model modified with the physical properties of the particle. The power consumption at the critical suspension condition in the shaking vessel was less than that in an agitated vessel with impeller.
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Hideo Shinagawa, Hiromichi Nakamura, Ken-ichi Miyamoto, Kikuo Okuyama
1995 Volume 21 Issue 5 Pages
952-956
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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The critical temperature and critical vapor pressure in the phase change to solid by heterogeneous nucleation of vapor-liquid coexisting systems in a closed chamber under reduced pressure were measured more than 50 times under the same experimental conditions by cooling liquid condensate. The sample materials were benzene,
p-xylene and water. The phase change to solid in the systems was observed visually to occur either by freezing of liquids or by solidification in vacant sites of a substrate in the same manner as our previous works. It is pointed out experimentally that the phase change to solid by heterogeneous nucleation of the vapor-liquid coexisting systems is a statistical phenomenon dependent on the difference between the pseudo-equilibrium temperature corresponding to the critical vapor pressure and the critical temperature
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Ikuho Yamada, Hideki Mori, Yuuki Kanayama, Liu Fang-Zhi, Zhang Hong Qu ...
1995 Volume 21 Issue 5 Pages
956-959
Published: September 10, 1995
Released on J-STAGE: November 12, 2009
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A calculation algorithm is proposed for solving operation type multistage distillation problems involving non-equimolar reactions. Since in this type of reaction system the total reaction rate cannot be evaluated before calculation, either set of variables, 1) boilup ratio and bottoms rate or 2) reflux ratio and distillate rate, is given as the problem specification.
The proposed algorithm is simple compared with the Newton-Raphson method and consists of two nested loops ; the inner loop determines composition profiles by stagewise calculation with the normalized θ method, and the outer loop finds the boilup rate or reflux rate which yields the specified bottoms rate or distillate rate. The numerical examples show the good convergence characteristics of the algorithm.
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1995 Volume 21 Issue 5 Pages
e1a
Published: 1995
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1995 Volume 21 Issue 5 Pages
e1b
Published: 1995
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1995 Volume 21 Issue 5 Pages
e1c
Published: 1995
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1995 Volume 21 Issue 5 Pages
e1d
Published: 1995
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1995 Volume 21 Issue 5 Pages
e1e
Published: 1995
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