JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 43 , Issue 11
Showing 1-11 articles out of 11 articles from the selected issue
Particle Engineering
  • Mehdi Arasteh, Abdolsamad Zarringhalam Moghaddam, Leila Yunchi, Mohama ...
    Type: Research Paper
    Subject area: Particle Engineering
    2010 Volume 43 Issue 11 Pages 921-926
    Published: September 01, 2010
    Released: November 20, 2010
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    The synthesis of cadmium sulphide (CdS) semiconductor particles by precipitation and the influence of different synthesis parameters on the crystalline size of the particles are reported. The response surface methodology (RSM, Box-Behnken) was used to optimize the operating conditions in order to minimize the crystalline size. The values of the parameters studied were in the following range: pH value of the solution: 5 to 10; treatment time: 2–6 h; and mixing rate: 1.5 × 103 to 4.5 × 103 rpm. The optimal conditions for achieving the minimum crystalline size of CdS were as follows: pH = 7.26, mixing time = 2 h, and mixing rate = 4.5 × 103 rpm, and the minimum crystalline size achieved under these conditions was 6.9 nm.
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Chemical Reaction Engineering
  • Muhammed M. Radhi, Wee T. Tan, Mohamad Z. B Ab Rahman, Anuar Bin Kassi ...
    Type: Research Paper
    Subject area: Chemical Reaction Engineering
    2010 Volume 43 Issue 11 Pages 927-931
    Published: September 01, 2010
    Released: November 20, 2010
    [Advance publication] Released: August 07, 2010
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    A glassy carbon electrode (GCE) was modified with a grafted polymer GP film (polystyrene grafted with acrylonitrile as a monomer using gamma irradiation) using a solution evaporation method to produce a new modified electrode GP/GCE. The redox process of K3[Fe(CN)6] during cyclic voltammetry was studied using the GP/GCE. It was found that the peak separation (ΔEpa-c) between the redox peaks of ferricyanide ion in an aqueous solution is 82 mV and the current ratio of redox peaks, (Ipa/Ipc), is 1 for the GP/GCE, indicating good reversibility with good conductivity of the modified electrode. Hence, it can be used for voltammetric analysis. The physical properties of the modified electrode GP/GCE include good hardness, high adhesion to the metal surfaces of electrode collectors, solubility and good stability of the GP on GCE at different pH levels. Also, the sensitivity under conditions of cyclic voltammetry is significantly dependent on the pH, the electrolyte used and the scan rate. At different scan rates, two oxidation peaks and two reduction peaks of Fe(III) were observed in a reversible process: Fe(III)/Fe(II) and Fe(II)/Fe(0).
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Separation Engineering
  • Masahiro Seshimo, Minoru Ozawa, Masato Sone, Makoto Sakurai, Hideo Kam ...
    Type: Research Paper
    Subject area: Separation Engineering
    2010 Volume 43 Issue 11 Pages 932-937
    Published: September 01, 2010
    Released: November 20, 2010
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    In this study, Pd/γ-alumina graded membranes were fabricated by an electroless plating method on nanoporous γ-alumina formed by anodic oxidation of an etched aluminum support, and the H2 permeability of the membranes was determined. The Pd/γ-alumina graded membrane on the etched aluminum support was prepared by carrying out electroless plating for 30 min, and for 60 min. In the first case of electroless plating for 30 min, Pd/γ-alumina graded membrane with a thickness of 2.5 μm, H2 flux of 0.28 mol m−2 s−1, and H2/N2 permselectivity of 817 were obtained. In the second case of electroless plating for 60 min, Pd/γ-alumina graded membrane with a thickenss of 4.5 μm, H2 flux of 0.17 mol m−2 s−1, H2/N2 permselectivity of 5259 were obtained. In durability tests, it was observed that the H2 flux increased with time in the initial stage and then become approximately constant after 70 h. The graded membrane exhibited high durability. The membrane formed by 60 min of electroless plating was heated at 773 K for 12 h in a furnace (preheated Pd/γ-alumina graded membrane). The H2 flux of the preheated graded membrane remined approximately constant during the durability test. This result implies that the Pd/γ-alumina graded membrane for the optimum H2 permeation was not obtained by heating because the Pd crystals formed by electroless plating, and recrystallized to form larger grains; this happened because of heating, hybridization of γ-alumina and Pd, and influence of annealing. Finally, we successfully fabricated novel Pd/γ-alumina graded membranes that exhibited high H2/N2 permselectivity, H2 permeability, and durability.
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  • Kazuki Akamatsu, Fang Han, Yasunobu Kaneko, Shin-ichi Nakao
    Type: Research Paper
    Subject area: Separation Engineering
    2010 Volume 43 Issue 11 Pages 938-945
    Published: September 01, 2010
    Released: November 20, 2010
    [Advance publication] Released: August 31, 2010
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    The crossflow filtration properties of monodisperse nanoparticle suspensions were investigated systematically by using flat ultrafiltration (UF) membranes for average nanoparticle diameters of 10, 45, and 80 nm. The relationships between (1) permeate flux and filtration time, (2) steady-state flux and applied pressure, and (3) limiting flux and feed concentration were studied under various experimental conditions. These relationships were found to be similar to those observed for the UF of aqueous macromolecular solutions, although the particle size of our target material was much larger than that of such macromolecules. In addition, the experimental data were analyzed by using the concentration polarization model, which is based on the mass balance beneath the membrane. As in the case of aqueous macromolecular solutions, the gel-layer concentration or limiting flux at low feed concentrations could not be explained well by the abovementioned model. Nevertheless, we demonstrated that UF membrane separation has the potential to be an effective processing technique for nanoparticle suspensions.
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Process Systems Engineering and Safety
  • Wensheng Lin, Ting Gao, Anzhong Gu, Xuesheng Lu
    Type: Research Paper
    Subject area: Process Systems Engineering and Safety
    2010 Volume 43 Issue 11 Pages 946-951
    Published: September 01, 2010
    Released: November 20, 2010
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    To investigate conditions that are likely to produce a boiling-liquid-expanding-vapor explosion (BLEVE), the determination of homogeneous nucleation rates of superheated liquids is often crucial. A new approach to estimate nucleation rates of superheated liquids is proposed; the approach is based on the probability distribution of the energy fluctuation within the framework of statistical thermodynamic fluctuation theory. Formulae for calculating the homogeneous nucleation rate in Gibbs canonical ensembles are deduced and tested for some substances. The calculated rates are compared with those obtained by the commonly used kinetic method as well as with experimental values. Finally, the new approach is validated by analyzing pressure rebounds of rapid discharge of pressurized liquefied petroleum gas (LPG). From the pressure rebound conditions, estimates of homogeneous nucleation rates can be obtained with both the kinetic and energy fluctuation approaches. Comparison of calculated results reveals that the new energy fluctuation approach is reasonably effective and has practical relevance in BLEVE research.
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  • Kazunori Kuwana, Kozo Sekimoto, Kozo Saito
    Type: Short Communication
    Subject area: Process Systems Engineering and Safety
    2010 Volume 43 Issue 11 Pages 952-955
    Published: September 01, 2010
    Released: November 20, 2010
    [Advance publication] Released: August 21, 2010
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    This short communication proposes a new scaling law, on the basis of which scale-model experiments on a large-scale wind-aided fire phenomenon can be designed. The proposed scaling law takes into account the Froude number, which is defined using the flame height. The results of two different scale-model experiments on the fire whirls observed after the Great Kanto Earthquake are reported. The wind velocities in the scale-model experiments are determined using the proposed scaling law. The scale-model experiments successfully reproduce fire whirls similar to those observed after the Earthquake, thus validating the proposed scaling law.
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  • Qing Guo, Masaru Noda, Hirokazu Nishitani
    Type: Short Communication
    Subject area: Process Systems Engineering and Safety
    2010 Volume 43 Issue 11 Pages 956-959
    Published: September 01, 2010
    Released: November 20, 2010
    [Advance publication] Released: August 07, 2010
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    In this study, we determine the operating conditions required to produce polymers with specific molecular weight distribution parameters in a continuous free radical polymerization reactor. Structural analysis of the mathematical model reveals that in the case of free radical polymerization that does not involve a termination-by-combination reaction, we cannot determine the set of operating conditions required for the production of polymers with a specific number-average molecular weight (Mn) and polydispersity index (PDI).
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Biochemical, Food and Medical Engineering
  • Satoshi Sasaki, Yusuke Mori, Masahiro Ogawa, Satoshi Funatsuka
    Type: Short Communication
    Subject area: Biochemical, Food and Medical Engineering
    2010 Volume 43 Issue 11 Pages 960-965
    Published: September 01, 2010
    Released: November 20, 2010
    [Advance publication] Released: August 11, 2010
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    The aim of this study was to realize spatially uniform illumination of a bacterial suspension using polydimethylsiloxane (PDMS) cells and to demonstrate the potential of a “quorum sensing reactor array”. After optimizing the conditions to obtain uniform luminescence, bioluminescent bacterial suspensions with different cell densities were encapsulated in 12 PDMS capsules and placed clockwise. Even without stirring, 11 capsules start/finish illumination in the order of cell density (density ratio ranged from 20 to 2−10). To realize such an array, spatially uniform bioluminescence was achieved by employing a geometrically symmetric supply of oxygen. A PDMS cell was suitable for this purpose. Suspensions with a depth of less than 2.71 mm showed spatially uniform luminescence without convection. In this study, for the first time, we provide an insight into an inhomogeneous suspension of bioluminescent bacteria. Understanding bacterial behavior at the suspension level, in addition to the genetic and cellular levels, would provide complementary information to comprehensively illustrate bacterial function.
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Materials Engineering and Interfacial Phenomena
  • Yoshiyasu Yamada, Shizuka Mitsuya, Takahiro Furuhashi, Shoji Ichihara, ...
    Type: Research Paper
    Subject area: Materials Engineering and Interfacial Phenomena
    2010 Volume 43 Issue 11 Pages 966-971
    Published: September 01, 2010
    Released: November 20, 2010
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    A novel electroplating method in which the foam of an electrolyte solution was used instead of liquid electroplating solutions was developed. The foam of the electrolyte solution was generated by bubbling nitrogen gas at a rate of 50–100 mL/min through 20 mL of modified Watt bath in which 2–6 × 10−3 wt% of sulfuric acid monododecyl ester sodium salt (SDS) was added as a surfactant. The nitrogen gas was introduced through a glass filter. The foam of the electrolyte solution drew electric current sufficient to cause electrochemical deposition. Nickel films deposited on brass substrates by this method had a considerably smaller number of pits and pinholes when compared to films deposited using a liquid electrolyte solution. It is suggested that the reduction in the number of pits and pinholes was a result of the prompt removal of hydrogen bubbles from cathode surface as a result of interaction of the hydrogen bubbles with the bubbles in the foam of the electrolyte solution. Uniform films were obtained by using a foam with an average bubble diameter of the submillimeter scale. The use of the foam of the electrolyte solution also required the use of a lesser amount of electroplating solution.
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Energy
  • Seiichi Inoue
    Type: Short Communication
    Subject area: Energy
    2010 Volume 43 Issue 11 Pages 972-976
    Published: September 01, 2010
    Released: November 20, 2010
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    Disposing of empty fruit bunches (EFBs) is an important problem in the palm oil production industry. Although part of an EFB is used as boiler fuel and fertilizer, most of it goes to waste, and consequently, the valuable energy contained in the woody waste is not utilized in the energy cycle. Herein, we examine EFBs as a fuel. EFBs were treated under hydrothermal conditions between 423 and 623 K without a catalyst to produce charcoal, which was subsequently compared with carbonization under dry nitrogen conditions. The hydrothermal conditions at 573 K and dry conditions at 873 K had similar charcoal yields of 31.4% and 27.8%, respectively. However, the calculated heating value of charcoal obtained from the hydrothermal conditions at 573 K was high (25.8 MJ/kg) compared to that obtained from the dry conditions at 873 K (22.0 MJ/kg). The FT-IR spectra showed that increasing the reaction temperature promoted carbonization of EFBs, and the intensity of the peak due to the –OH of EFBs became weak. Hence, carbonization of EFBs is promoted at low temperature under hydrothermal conditions compared with dry conditions.
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General Research and Others
  • Takahiro Takahashi, Noriyuki Fukui, Masamoto Arakawa, Kimito Funatsu, ...
    Type: Research Paper
    Subject area: General Research and Others
    2010 Volume 43 Issue 11 Pages 977-982
    Published: September 01, 2010
    Released: November 20, 2010
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    We have developed a modeling system for the calculation processes of a process simulator for chemical vapor deposition (CVD). The system consists of a software agent, generalized modeling software and a simulator reproducing cross-sections of the deposited films. The agent autonomously creates appropriate models by operating the simulator and the modeling software. The models are calculated by partial least squares regression (PLS), quadratic PLS (QPLS) and error back propagation (BP) methods using artificial neural networks (ANN) and expresses by mathematical formulas to reproduce the calculated results of the simulator. In addition, we have investigated the performance of the models. The models show good reproducibility and predictability both for uniformity and filling properties of the films calculated by the simulator. The models using the BP method yield the best performance. The filling property data are more suitable to modeling than film uniformity. Since the simulator can be replaced by the models, the models will contribute towards decreasing the calculation costs for predicting the experimental results. This study thus presents an example of creating a robust and reliable predictor as a virtual reactor yielding experimental results that is expected to be free of the difficulties of extrapolation, using ANN and other mathematical models.
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