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Tamiya Kishimoto, Yasuharu Akagi
1989 Volume 15 Issue 6 Pages
1051-1056
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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To decrease excess sludge in the anaerobic fermentation of excess sludge from a waste water treatment plant by the activated-sludge method and to increase generation of methane gas, the effect of ozonation of excess sludge on methane gas generation and the decrease of sludge volume was investigated experimentally.
When ozone gas was fed in solutions containing excess sludge at concentrations of 6 to 17kg/m
3 for 5 to 15min at a flow rate of 0.378m
3/hr, both
COD and
BOD concentrations of the solution increased with partial decomposition of the excess sludge. Thus, about 20% of the organic material in the excess sludge was decomposed and was solubilized in water, regardless of initial pH. When the solution afterozonation was fermented anaerobically, methane gas and other gases generated perunit weight of organic material increased to 1.5-2.7 and 1.7-3.7 times respectively, compared with levels at no ozonation. Ozonation of the excess sludge was effective for methane fermentation.
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Fuming Chen, Yuji Naka, Hiroyuki Tanaka, Eiji O'Shima
1989 Volume 15 Issue 6 Pages
1057-1063
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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To develop a method for the selection of a diluent that increases D
A, the distribution ratio for extraction of organic acid with amine, diluent effects on the extraction of acetic acid with tri-
n-octylamine (TOA) were investigated. The experimental data show that D
A depends on the kind of diluent and the mixing ratio of TOA to diluent.
A model composed of both dominant association and physical distribution is proposed to describe the extraction equilibrium. The equilibrium constants of the association involved in the model can be estimated on the basis of the excess volume with respect to the pseudo-binary mixture of TOA and acetic acid. The D
A's predicted by the model are consistent with the experimental data. It is found that diluents of strong acceptors decrease the associating order of acetic acid with TOA, and make D
A high in the region of low C
A, aq. Finally, this paper proposes an approach to the selection of diluent based on these results.
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Masashi Kuramae, Makoto Ito
1989 Volume 15 Issue 6 Pages
1064-1072
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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Physical models of a heat pipe for analyzing dynamic heat transfer characteristics have been proposed. These models have been established (a) by lumped parameter approximation, (b) by considering only axial thermal resistance, (c) by considering only radial thermal resistance, and (d) by considering both axial and radial thermal resistances. Theoretical considerations are di scussed for these models regarding physical meanings of the parameter and the relationships between these models. Experimental investigations have been carried out for typical heat pipes and the thermal response results obtained were compared with those predicted from the above-mentioned physical models. It is shown that the estimation of the lumped model has been given too small a value of time constant and that of the homogeneous model has been given too large a value in comparison with experimental results, while relatively good results have been obtained with the structural model or stairs model.
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Norio Arai, Akio Yamamoto, Masanobu Hasatani
1989 Volume 15 Issue 6 Pages
1073-1079
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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An ultrasonic CT method was proposed for a new type of indirect thermometry, and its applicability was demonstrated for measuring the temperature distribution of liquid layer. An axis -symmetrical temperature field of a coaxial jet flow was chosen as the objective field to check the validity of the proposed thermometry. Temperature dependence of sound velocity in an isothermal pure water was preliminarily measured by an ultrasonic pulse technique.
Cross-sectional distribution of sound velocity in the coaxial jet flow, obtained from a two-dimensional Fourier transform (TFT) method using propagation times measured by the ultrasonic pulse technique, was transformed into the temperature distribution, taking account of the predetermined temperature dependence of sound velocity.
The reconstructed temperature distribution thus obtained acoustically was compared, with measurements by the existing thermocouple method. The reconstructed temperatures were a little different from the measured ones in the vicinity of the center of the cross section, but a relative comparison of these two distributions showed that the former was comparable to the latter.
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Hiroshi Kurahashi, Masanao Imai, Shoji Urushiyama, Masaru Shimizu
1989 Volume 15 Issue 6 Pages
1080-1086
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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The water permeation coefficients of a thin organic phase containing an amphiphilic component were determined by measuring the rate of water permeation across the thin organic phase. The organic phase was composed of kerosene and amphiphilic component (Span 80®). It was immobilized in microporous polycarbonate membranes. The water permeation coefficients were inversely proportional to membrane thickness, and not dependent on the concentration difference of hydrochloric acid in the aqueous phase. They increased with the concentration of amphiphilic component in the range lower than 3wt%, but gradually decreased in the concentration range higher than 3 wt%.
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Tadashi Ise, Manabu Yamaguchi, Takashi Katayama
1989 Volume 15 Issue 6 Pages
1087-1094
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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The aggregation process of water droplets in oil phase in an a.c. electric field was studied theoretically and experimentally as a fundamental means of electrostatic demulsification of water-in-oil emulsion. The droplets line up into a lengthwise extended chain in the direction of the field (chain formation), and then coalescence between the droplets is promoted by the electric field. An equation for interaction force between a lengthwise extended chain and an isolated droplet was derived and solved numerically.
Behavior of chain formation and coalescence of small water droplets in oil phase in the electric field was studied under a microscope. For chain formation, the calculated results show good agreement with the experimental ones. The electric potential difference required for electrical coalescence between two droplets is about 1-1.5 V.
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Kengo Shimizu, Hayatoshi Sayama, Yoshimasa Kameyama, Kazuhiko Suzuki
1989 Volume 15 Issue 6 Pages
1095-1101
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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A number of computational methods have been proposed for solving multicomponent vapor-liquid equilibrium and distillation problems. Many of these methods employing a gradient-type algorithm involve numerical differentiation for evaluation of the partial derivatives. This may require a large amount of computation time and often gives rise to numerical instability, especially in problems with microcomponent. This paper presents a new computation procedure for multicomponent nonideal vapor-liquid equilibrium problems. The liquid compositions are chosen as the independent variables and the temperature is considered as the dependent variable. The partial derivatives of vapor compositions with respect to the liquid compositions are derived analytically by making use of the implicit function theorem. The iterative solution procedure is based on the gradient method (Newton-Raphson or Gauss-Newton method), which uses analytical equations for the partial derivatives and approach to the solutions with the liquid and vapor composition constraints satisfied. The iteration procedure gives numerically stable and rigorous solutions to multicomponent dew point problems.
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Wataru Eguchi, Masataka Tanigaki, Kunio Mutoh, Hiroshi Tsuchiya, Eiji ...
1989 Volume 15 Issue 6 Pages
1102-1108
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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The consumption rate of nitrous acid in aqueous solutions isolated from gas phase was measured at 288313K.
The decomposition of nitrous acid in an aqueous solution progresses according to the elementary reactions proposed by several investigators based on experiments carried out in gas-liquid systems. However, this reaction must be treated as a reversible one when the aqueous solution is isolated from the gas phase. Furthermore, when oxygen is dissolved into the aqueous solution, nitrous acid also disappears by oxidation in addition to decomposition. The rate-controlling step of the oxidation of nitrous acid is the aqueous-phase oxidation in which nitrogen monoxide formed from nitrous acid reacts with the dissolved oxygen.
On the basis of the above considerations, the rate equations of the overall decomposition of nitrous acid and the oxidation of nitrogen monoxide in aqueous solution are derived, and the rate constants are determined at 288313K. The overall rate equation for the consumption of nitrous acid in aqueous solution containing dissolved oxygen is also derived.
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Wataru Eguchi, Masataka Tanigaki, Kunio Mutoh, Hiroshi Tsuchiya
1989 Volume 15 Issue 6 Pages
1109-1114
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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The oxidation reaction of iodide ion by nitrous acid was examined in an aqueous acidic solution with a spectrophotometer and a stopped-flow rapid reaction analyzer.
The overall reaction is as follows :
2I
-+2HNO
2+2H
+→I
2+2NO+2H
2O
When [I
-] 0< [HNO
2]
0, the production of I
2 stopped at [I
2] ∞= (1/2) [I
-] 0. On the other hand, when [I
-]
0> [HNO
2]
0, the production of I
2 proceeded beyond the stoichiometric level of (1/2) [HNO
2]
0. This was found to be due to the reaction of NO, produced by the above reaction, with the dissolved oxygen, which reproduced HNO
2.
In the present work, the rate of the complex reaction of I
- with HNO
2 was formulated by measuring the initial reaction rate with a stopped-flow rapid reaction analyzer. The time course production of I
2 was successfully followed by this rate expression.
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Wataru Eguchi, Masataka Tanigaki, Kunio Mutoh, Hiroshi Tsuchiya
1989 Volume 15 Issue 6 Pages
1115-1119
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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Observation with a spectrophotometer of the reaction of iodide ion with nitrous acid in aqueous solutions revealed that the reaction to produce I
2 to the stoichiometric level of the overall reaction is rapid when the concentration of nitrous acid is higher than that of iodide ion. However, when the concentration of iodide ion is higher than that of nitrous acid, the nitrogen monoxide produced is oxidized by the dissolved oxygen in the solution to form nitrogen dioxide, which in turn produces nitrous acid. The oxidation reaction of iodide ion, consequently, proceeds beyond the stoichiometric level. This additional production of I
2 was found to be controlled by the oxidation reaction of nitrogen monoxide in the aqueous solution.
Based on the above observation, the overall reaction of iodide ion with nitrous acid in the aqueous phase was studied with a stopped-flow rapid reaction analyzer, and the rate expression and the temperature dependency of the oxidation reaction of nitrogen monoxide were clarified. The rate expression obtained was of same form as that of the reaction in gas phase. However, it was found that the reaction has a positive temperature dependency in contrast to that in gas phase.
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Shogo Sudo, Hideji Yamamoto, Mototake Yano, Yoshio Harano
1989 Volume 15 Issue 6 Pages
1120-1125
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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Changes in light transmittance and electrical conductivity of solution with elapsed time and the change in light transmittance due to the sedimentation of final product crystals in a batchwise reactor were inputted directly and continuously in a microcomputer, and the size distribution of final products, secondary nucleation rate and linear growth rate were obtained automatically.
This system was applied to the crystallization of [A] : L-aspartic acid (S
0 = 2.9-3.9) and [B] : fumaric acid (S
0 = 1.3) from aqueous solution. The following results were obtained for [A]. 1) Secondary nucleation rate and the minimum size
rmin were dependent on agitation rate and initial supersaturation ratio. 2) Secondary nuclei were born mainly by collision of mother crystals larger than
rmin, and the secondary nucleation rate was estimated to be expressed by
dN/dt=
knNm2S10, where
Nm, is the number of crystals larger than
rmin in unit volume. 3) Crystal growth rate is determined by surface two-dimensional nucleation rate, and surface energy σ and the radius of two-dimensional critical nucleus
rc' were estimated to be 8.0 erg·cm
-2 and 0.39 nm at S =2.0. For [B], crystal growth rate is explained by the BCF theory.
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Masayuki Sato, Yoshihisa Noguchi, Yoshiko Inoue, Masayoshi Sadakata
1989 Volume 15 Issue 6 Pages
1126-1131
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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New equipment for electrofusion of plant cells was developed for the purpose of automatic cell handling and fusion with electrical control of cell movement under a microscopic view, using the electrode configuration of a convergent electric field. Two cells (A and B) of different species introduced from separate inlet ports were moved toward the position of the convergent electric field by the applied 1MHz high frequency AC gradient field. The cells became attached to each other, making a pearl chain. When a pulsed electric field was applied to the electrodes, the two cells fused into one hybrid cell (A + B cell). The velocity of the dielectrophoretic cell movement and the operative conditions of the electrofusion were obtained using three kinds of plant cells to defermine the functions of applied AC voltage and frequency, pulse voltage and width. respectively.
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Tahei Tomida, Masahiro Kubo
1989 Volume 15 Issue 6 Pages
1132-1137
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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A light beam (wave length 254nm) of 3 mm width was applied to a dispersion of small bubbles through the optical window of a rectangular cell, and the intensity profile of transmitted light throughout the cell was measured with a photocell for 3cm in axial length in steps of 0.3mm length. The effective attenuation coefficient of dispersions of the small bubbles, μ
e, was evaluated from the observed intensity profiles of transmitted light. However, it was shown that the estimated rate of light absorption using μ
e was higher than that measured using the photoreduction of potassium ferrioxalate as an actinometer.
The effective light path length calculated from the volumetric rate of light absorption based on a parallel-plate model was correlated with the gas holdup irrespective of the attenuation coefficient of the solution or the diameter of bubbles.
The simple method described here was concluded to be useful for estimating the volumetric rate of light absorption in a small bubble dispersion system.
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Yuji Shindo, Naotsugu Itoh, Kenji Haraya, Katsuhiko Wakabayashi
1989 Volume 15 Issue 6 Pages
1138-1143
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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Theoretical analysis of a membrane reactor was performed for a first-order reversible reaction by use of kinetic equations including both reaction-rate and separation-rate terms.
Several fundamental conclusions were drawn with respect to a membrane reactor from the standpoint of chemical reaction engineering.
It was found that there was an ideal maximum value for the overall conversion of a membrane reactor. The relation between ideal maximum conversion, membrane selectivity and equilibrium constant was obtained. Design conditions and operation conditions under which a membrane reactor is effective were examined.
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Masato Tanaka, Kenji Hayashi
1989 Volume 15 Issue 6 Pages
1144-1152
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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Polystyrene particles coated uniformly with ferrite powder were prepared by suspension polymerization. Ferrite powder was treated to vary wettability by a silane coupling agent.
The operational conditions changed stepwise were the amount of ferrite powder added, the contact angle between powder and styrene monomer, and the impeller speed. The effects of the operational conditions on various properties of composite particles such as size distribution and mean size of particles, dispersity, yield, and adhesive strength were investigated.
To investigate how ferrite powder adheres to the surface of particles depending on the contact angle, microscopic observation of the surface and cross section of composite particle was performed.
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Takashi Hibiki, Manabu Yamaguchi, Takashi Katayama
1989 Volume 15 Issue 6 Pages
1153-1159
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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Formation of single charged drops from a laminar liquid jet issuing from an electrified nozzle in a nonuniform electric field was studied for the systems of xyleneair and water-air, -cyclohexane, -hexane and -silicone oil. The field was formed by a configuration of an electrified nozzle arranged vertically above a flat earthed electrode. The jet length, jet radius and drop diameter decrease with applied voltage. It was shown that the experimental drop diameters agree well (within ± 10%) with those calculated by using wave number and growth rate for interfacial wave for all systems. It was clarified experimentally that a whipping action of the jet is caused by applying voltage when the electric pressure acting on the jet is greater than the interfacial one acting on the jet.
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Norihisa Fushida, Nobuyuki Tatsukawa, Masanobu Hasatani, Norio Arai, Y ...
1989 Volume 15 Issue 6 Pages
1160-1165
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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The objective of this study was to develop an analysis of heat transfer in foods during heat treatment. An experiment was conducted to heat stepwise a loaf of bread and/or a B5 brick as a food and a standard sample respectively for comparison in an electric oven. The time behavior of the temperature distribution measured for the brick shows good agreement with the result calculated on the basis of the unsteady three-dimensional conductive heat transfer equation with boundary conditions involving both convective and radiative heat transfer. The results calculated by theoretical analysis agrees well with the experimental data for the bread in the oven undes a temperature of about 335K. However, at oven temperatures higher than 373K a difference between the experimental data and theoretical results appears, and it is suggested that the influence of such interactions as moisture transfer and some chemical and/or physical changes on heat transfer in the bread may be significant.
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Ryuzo Ito, Yushi Hirata, Akio Ikuta
1989 Volume 15 Issue 6 Pages
1166-1171
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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Mixing characteristics in Taylor vortexes have been investigated by flow visualization and concentration response. Laminar Taylor vortexes have a distinctive mixing pattern with extremely low mixing rate in comparison with transition and turbulent Taylor vortexes. The mixing process in the latter two vortex modes hasbeen satisfactorily described by the perfectly mixed tanks in series model, which accounts for the mass exchange through the interface between adjacent vortexes by introducing an intermixing velocity. The Kolmogoroff dissipation velocity scale calculated from the torque acting on the rotating cylinder is found to be a parameter suitable to correlating the intermixing velocity and characterizing the vortex behavior from transition to fully turbulent mode. In fully turbulent Taylor vortexes, the intermixing velocity varies in proportion to the Kolmogoroff velocity scale.
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Hideaki Asai, Satoru Kato, Kunio Nagahama
1989 Volume 15 Issue 6 Pages
1172-1178
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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Solubilities of three kinds of aqueous alcohol solutions (methanol-, ethanol- and 1-propanol-water systems) in a Nafion membrane were measured to elucidate permeation mechanisms in pervaporation.
Solubilities of a pure solvent in the membrane could be well estimated by use of Flory -Huggins' equation.
Membrane solubility parameters determined from the equation were independent of the kind of counterions. However, Flory -Huggins' equation could not estimate the solubilities of alcohol-water mixtures in the membrane except for cases in which the solubility of one of the solvents is low. The relations of membrane free composition and equilibrium composition in the liquid phase were successfully correlated by use of apparent activity coefficients.
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Toshiro Murase, Eiji Iritani, P. Chidphong, Katsuhiro Kano
1989 Volume 15 Issue 6 Pages
1179-1186
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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A coaxially rotating cylinder type of dynamic filter with a ceramic membrane was used for microseparation of a “difficult-to-filter” suspension containing very fine particles. In this study a high filtration rate of suspended yeast was investigated, using a periodic dynamic filtration by rotating the cylindrical membrane intermittently.
Periodic dynamic filtration comprises two operational modes : 1) the filtering ofa dilute suspension with a static membrane at a constant pressure, and 2) the sweeping of filter cake from the membrane by closing the filtrate drainage channel and rotating the membrane at a high speed. A much higher filtrate flux can be achieved by this newly developed technique than that produced by conventional dynamic filtration with a continuously rotated medium. Based on the fact that medium resistance can be empirically evaluated in terms of the repeated number of filtration cycles, Ruth's filtration equation is used here to predict the time change of filtrate volume. It is shown that the optimum filtration time, θ
f·opt, gradually increases with the increase of total operational time, θ
t.
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Toshio Kajiuchi, Naohiro Shiragami, Kunio Nagasaka, Toshihiro Asanuma
1989 Volume 15 Issue 6 Pages
1187-1192
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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Flow characteristics in a peristaltic bioreactor were studied experimentally by the flow visualization technique. It was observed by the dye injection method that the fluid close to the peristaltic wall moved forward, and the fluid in the center region moved backward both with forward and backward motions during one period cycle. It was found that the fluid in the container moved only within the compartment which is divided by imaginary walls. The existence of the imaginary walls was confirmed by longitudinal velocity profiles obtained from tracer trajectories. The similarity of the longitudinal velocity profiles was also shown experimentally.
By considering the cross-sectional flow rate, it was shown that the imaginary walls exist at locations which satisfy an integer multiple of the wave length.
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Chikao Arai, Takuo Yoshitama, Kenji Nishihara, Yoshiki Sano
1989 Volume 15 Issue 6 Pages
1193-1195
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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Experimental data were obtained for the solubilities of helium, hydrogen, nitrogen, oxygen and carbon dioxide in methyl, ethyl and
n-butyl esters of oleic acid.
In the range from 273.2 to 343.2 K, Henry constants of helium, hydrogen and nitrogen decrease with increase in temperature, but that of carbon dioxide increases. The temperature dependence of Henry constant is represented by the following equation for
n-butyl oleate :
ln
H=
B1/
T+
B2 ln
T+
B3T+
B4
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Syouji Hirota
1989 Volume 15 Issue 6 Pages
1195-1197
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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Face growth rates were measured on (101) and (100) faces of a KDP (KH
2PO
4) crystal at different supersaturations in the presence of aluminium ion added as impurity. The supercooling temperature was also measured. The growth rate of (100) face decreased dramatically. When the impurity was added, the critical supercooling temperature increased and the crystallized particle size increased.
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Qian-Qiu Zhao, Genji Jimbo
1989 Volume 15 Issue 6 Pages
1197-1200
Published: November 10, 1989
Released on J-STAGE: October 21, 2009
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Dry grinding experiments were carried out with a planetary ball mill. Layer particles adhering to the mill wall and freely movable particles in the mill were separated from each other and changes in their weight fractions, size distributions and specific surface areas with grinding time were measured for various balls, feed sizes and powder fillings. Certain correlation between the decrease of grinding rate and the increase of coating particles was confirmed and a new empirical equation for expressing the change of specific surface area of product in batch grinding were derived.
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