巻号一覧
40 巻, 9 号
選択された号の論文の15件中1～15を表示しています
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Physical Properties and Physical Chemistry
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Mohammad Washim Uddin, Maki Takano, Setsuko Akakabe, Kazuhiro Hoshino, ...原稿種別: Short Communication
2007 年 40 巻 9 号 p. 693-697
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありAn experimental investigation concerning the dissociation equilibrium in a gel was carried out by using Chelating Sepharose Fast Flow gel and buffer solutions. It was noted that the gel swelled or shrank somewhat to adsorb or release mobile ions and water, and the degree of change slightly depended on the pH of the solution. It was found that the relationship between the degree of dissociation of fixed two –CH2COOH groups in gel and the concentration of hydrogen ions in the outer aqueous phase could be correlated by an equation based on the dissociation equilibrium. It was shown that the relationships for dissociation equilibrium based on theory were closely consistent with the experimental values. Finally the total concentration of the fixed two –CH2COOH groups in gel was obtained as 2.68 × 10–2 mol/kg-wet gel.抄録全体を表示PDF形式でダウンロード (405K)
Transport Phenomena and Fluid Engineering
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Jalil Moghadasi, Mohammad Mehdi Papari, Fakhri Yousefi, Behzad Haghigh ...原稿種別: Research Paper
2007 年 40 巻 9 号 p. 698-710
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありViscosities, diffusion coefficients, thermal conductivities and thermal diffusion factors for seven binary gaseous mixtures H2–CO2, H2–N2, H2–CH4, H2–C2H6, N2–CH4, N2–C2H6, CH4–C2H6, one ternary gaseous mixture N2–CH4–C2H6 and one quaternary gaseous mixture H2–N2–CH4–C2H6 were determined based on the principle of the corresponding states of viscosity together with the inversion technique. The calculated transport properties have been compared with those obtained from other methods and also from experimental data. Our estimated accuracies are to within ±3% for the viscosity, ±5% for the binary diffusion coefficient and ±14% for the thermal conductivity.抄録全体を表示PDF形式でダウンロード (546K) -
Kyung C. Kwon, YoonKook Park, Paul Jones原稿種別: Research Paper
2007 年 40 巻 9 号 p. 711-717
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありA tank-tube viscometer and its novel non-Newtonian viscosity equation were developed to determine flow characteristics of non-Newtonian fluids. The objective of this study is to test capabilities of the tank-tube viscometer and its novel non-Newtonian viscosity equation by characterizing rheological behaviors of dairy products. The rheological behavior of fluid milk such as simulated fluid milk and grocery fluid milk such as skim milk and whole milk were characterized with the viscometer, using water as a reference calibration fluid. The non-Newtonian viscosity equation was developed under the assumptions that a quasi-steady state approach is valid, and the friction loss due to a sudden contraction between the reservoir tank and the tube is negligible for laminar fluid flows, using L’Hospital’s rule. Simulated fluid milk was prepared by adding dry nonfat milk powder to water, whereas commercial fluid milk such as skim milk and whole milk was purchased from a grocery store. The only experimental data required is the mass of the fluid milk that drains from the viscometer at a given drain duration. The concentration of dry nonfat milk powder in simulated fluid milk ranges from 4 to 10 wt%. As the concentration of dry nonfat milk powder in simulated fluid milk increases, the flow behavior index of simulated fluid milk decreases. Raising the temperature from 12 to 26°C, the flow behavior index of simulated fluid milk containing 4 wt% dry milk powder increases from about 0.7 to 0.9. The apparent viscosity values of the 4 wt% simulated fluid milk exhibits Arrhenius behavior with respect to temperature.抄録全体を表示PDF形式でダウンロード (576K) -
Honghai Xiao, Koji Takahashi原稿種別: Research Paper
2007 年 40 巻 9 号 p. 718-723
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありIn this work the gas dispersion of a Rushton disc turbine impeller was investigated in a horizontal non-baffled stirred vessel in comparison with the normal vertical baffled stirred vessel. The Rushton turbine and vertical baffled vessels are commonly used for gas dispersion mixing. The flooding/loading transition and the gas–liquid mass transfer coefficient kLa were measured at the gas flow rates of 0.5–2vvm. The results indicated that kLa against energy dissipation rate in the horizontal tank was better than that in the vertical baffled tank, and roughly equal loading/flooding transition for the two kinds of vessels was obtained. The correlations of kLa and the loading/flooding transition were correlated according to the present data.抄録全体を表示PDF形式でダウンロード (985K) -
Hirotsugu Hattori, Masatsugu Yamagishi原稿種別: Research Paper
2007 年 40 巻 9 号 p. 724-729
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありThe reason why an atomizer works is frequently explained by applying Bernoulli’s theorem to the air jet which forms behind an air release pipe. As early as 1948, Tani pointed out that applying Bernoulli’s theorem to the air jet of an atomizer was not correct. He described that the pressure should be the atmospheric pressure at anywhere in the air jet. He explained that the reason an atomizer works consists in the fact that the suction pipe is partly located in the air jet. He carried out brief experiments. In spite of the existence of Tani’s theory and his brief experiments, the mistaken explanation, in which Bernoulli’s theorem is applied to the air jet, appears in many publications today.
In this study, air flow patterns were observed and pressure distribution was measured mainly by using a large-scale model whose shape is geometrically similar to that of a small prototype of the atomizer, under the condition of dynamic similarity. These experimental results reconfirmed Tani’s theory about why an atomizer works.抄録全体を表示PDF形式でダウンロード (1400K)
Separation Engineering
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Qingfeng Yang, Dmitry Lisitsin, Yangqiao Liu, Hasson David, Raphael Se ...原稿種別: Research Paper
2007 年 40 巻 9 号 p. 730-735
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありOne way for the reuse of reverse osmosis (RO) concentrates and thus increasing the water recovery is to recycle part of the brine concentrate to the feed, after precipitating the scaling salts such as CaSO4/CaCO3 held in solution by antiscalants. However, antiscalants impart considerable stability to the supersaturated solution. In the present study, desupersaturation of RO CaSO4 concentrate in the presence of antiscalants was studied by addition of coagulant polyaluminum chloride (PACl) and surfactant sodium dodecyl sulfate (SDS). Simulated experiments for testing the changes in antiscalant concentration were also conducted. The results indicated that under certain conditions, the above methods were effective for desupersaturation of RO concentrate. After the removal precipitation reactions, the calculated supersaturation ratio of the test solution deceased to about 1.0, which demonstrated that the test solution reached thermodynamic equilibrium. With respect to the removal of scaling salt, it was found to follow the second order kinetics. The removal of scaling salt was always accompanied by the adsorption precipitation of antiscalants. The ecomonic analyses show the proposed methods were feasible.抄録全体を表示PDF形式でダウンロード (478K) -
Kenichiro Suzuki, Toshiya Takeda, Meiyi Le, Maki Shinkai, Shoji Kagawa原稿種別: Short Communication
2007 年 40 巻 9 号 p. 736-740
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありIn this study we propose new techniques for evaluating operating conditions employed for vacuum pressure swing adsorption (VPSA) in the recovery of volatile organic compounds (VOC). The new method incorporates a precoating step for the mesoporous activated carbon in the adsorption column, but does not use purge gas for the desorption step. The evaluation technique employs the arrival time of cyclic steady state (TA) as a measure of effectiveness. By precoating the mesoporous activated carbon with adsorbate, the concentration of purified gas was reduced to the detection limit of measurement without using purge gas, and VOC were recovered in the liquid state. We also performed evaluations under a variety of operating conditions using TA.抄録全体を表示PDF形式でダウンロード (666K)
Chemical Reaction Engineering
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Naoki Takahashi, Kazuhiko Dohmae, Hideo Sobukawa, Hirofumi Shinjoh原稿種別: Research Paper
2007 年 40 巻 9 号 p. 741-748
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありThe predominant factor in catalytic low-temperature NO oxidation under an oxidative condition over supported Pt, Pd and Rh catalysts was investigated and discussed using a thermodynamic calculation, XPS analysis, CO adsorption, and reaction evaluation. New insights were gained as follows; the resistance to metal oxide formation of these metals is important for NO oxidation activity under an excess oxygen condition. In the fresh catalysts, the oxidation status of Pt was affected by the electronegativity of the support cation, and the Pt supported on a more acidic support has a higher NO oxidation activity. After aging treatment, the oxidation status of Pt on each support was almost the same, and a large amount of surface metallic Pt favors Pt catalysts to have high activity. The analysis of the NO oxidation kinetics revealed that the affinity of Pt for NO molecules was improved with the aging treatment. It could be concluded that a suitable combination of Pt and the support facilitates high dispersion of the metallic Pt, even after the aging treatment, which is favorable for the NO oxidation in the presence of excess oxygen at low temperature.抄録全体を表示PDF形式でダウンロード (548K) -
Sho Suzuki, Hidetoshi Sekiguchi, Koichi Takaki原稿種別: Research Paper
2007 年 40 巻 9 号 p. 749-754
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありThe effects of electron density and electron temperature on the partial oxidation of benzene using a micro-plasma reactor have been studied here. The plasma was generated by the dielectric barrier discharge at the atmospheric pressure. The electron density and electron temperature are key parameters for the plasma reaction of benzene. By changing the combinations of discharge conditions including the applied voltage, discharge gap, and discharge frequency, the electron density and electron temperature could be controlled. Applying the higher voltage, both the electron density and electron temperature were increased. Along with increasing the discharge frequency and reducing the discharge gap at a constant input power, the electron density increased whereas the electron temperature decreased. Higher electron densities and higher electron temperatures resulted in the enhancement of the benzene conversion. In addition, the phenol selectivity did not varied greatly with the change of electron density, while it was slightly enhanced with the increase of electron temperature. The micro-plasma reactor made it possible to change the electron density and electron temperature largely, and it has a potential to control chemical reactions effectively.抄録全体を表示PDF形式でダウンロード (481K) -
Nizamettin Demirkiran原稿種別: Research Paper
2007 年 40 巻 9 号 p. 755-760
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありAmong boron minerals, ulexite is one of the most common substances and is found in great amount in Turkey. Ulexite, sodium-calcium-borate hydrate, has a chemical formula of Na2O·2CaO·5B2O3·16H2O. In this study, the leaching kinetics of calcined ulexite in ammonium nitrate solutions was investigated in a batch reactor employing the parameters of calcination temperature, concentration, particle size, stirring speed and reaction temperature. It was found that the dissolution rate increased with increasing concentration and reaction temperature and with decreasing particle size. No effect of stirring speed was observed on the conversion. It was determined that the dissolution rate fit the chemical reaction control model. An empirical equation for the process was derived as 1 – (1 – x)1/3 = 3.5 × 104C0.31D–0.80exp(–46.5/RT)t. The activation energy of this dissolution process was found to be 46.5 kJ mol–1.抄録全体を表示PDF形式でダウンロード (438K) -
Hirotsugu Hattori, Eiki Hata, Tsukasa Uchino原稿種別: Short Communication
2007 年 40 巻 9 号 p. 761-764
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありOzone decomposition on the iron oxide catalyst was carried out in four types of spouted beds and the gas conversions were compared, for the purpose of comparing the gas–solid contacting efficiency of these spouted beds. These four types include a top-sealed spouted bed, a screen-bottomed spouted bed, and top-outlet spouted bed with or without a draft-tube. The top-sealed spouted bed and the screen-bottomed spouted bed provided higher gas conversion compared with the other two types of spouted beds. The gas–solid contacting efficiency of these spouted beds was compared with that of a hypothetically isothermal fixed bed. The top-outlet spouted bed with a draft-tube provided poorer contacting efficiency than the other types of spouted beds.抄録全体を表示PDF形式でダウンロード (478K)
Process Systems Engineering and Safety
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Luo Yan, Liu Xiwei, Masaru Noda, Hirokazu Nishitani原稿種別: Research Paper
2007 年 40 巻 9 号 p. 765-772
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありIndustrial plant alarm systems form an essential part of the operator interfaces for automatically monitoring of plant state deviations and for attracting the plant operator’s attention to the changes that require his/her intervention. To design an efficient alarm system that assists operators to quickly identify the causes of abnormalities and to respond to the situations is vital for the safe operation of the plant. The Engineering Equipment and Materials Users Association (EEMUA) provided the general design and evaluation principles of plant alarm systems. We are proposing a systematic design approach for plant alarm systems using this guide. In the design stage, a set of alarm source signals are selected and then the alarm limits setting is determined. For alarm system rationalization, we have prepared countermeasures against repeating alarm suppression. To evaluate the designed alarm system, we used the criteria provided by the EEMUA 191 guide and other simulation evaluation indexes, such as the malfunction identification time of a human operator model. The design methods were applied to a boiler plant alarm system for this case study and the evaluation results prove the usefulness of the proposed approach.抄録全体を表示PDF形式でダウンロード (546K)
Energy
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Ju-Myeung Lee, Taichi Ito, Takeo Yamaguchi原稿種別: Research Paper
2007 年 40 巻 9 号 p. 773-779
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありFor the practical use of a polymer electrolyte membrane fuel cell (PEMFC), the structure optimization of the electrode is important in obtaining high performance. Usually, a perfluorosulfonic acid (PFSA) ionomer is used as a binder in the electrode for a novel hydrocarbon electrolyte membrane by many pieces of research because the optimization of hydrocarbon electrode is difficult. However, to reduce costs and the environment load of the F element, the development and the optimization of hydrocarbon electrode for hydrocarbon instead of the PFSA electrode is necessary in the end. This research focused on the adoption of sulfonated poly(arylene ether sulfone) (SPES) as an example of a hydrocarbon ionomer to the electrode and the relationships between the structure of the catalyst layer and the size (radius of gyration) of the SPES related with the molecular weight as a fundamental research for the optimization of the hydrocarbon electrode. From the aspect of the structure of the electrode, we controlled the molecular weight of the SPES in order to enlarge the three-phase boundary for the electrode reaction. We have examined the correlation of the molecular weight of SPES and catalyst utilization, and the structure change of the catalyst layer was observed. The electrode fabricated with low molecular weight SPES showed a high utilization of the catalyst and good fuel cell performance.抄録全体を表示PDF形式でダウンロード (999K) -
Joelianingsih , Hiroshi Nabetani, Shoji Hagiwara, Yasuyuki Sagara, Tat ...原稿種別: Research Paper
2007 年 40 巻 9 号 p. 780-785
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありA bubble column reactor has been developed to produce fatty acids methyl esters (biodiesel) by blowing superheated methanol continuously into vegetable oils without using any catalysts at atmospheric pressure. Two types of reactions exist in this method for methyl esters formation; transesterification of triglycerides and esterification of fatty acids. A kinetic study for the transesterification of triglyceride has been studied at 250–290°C. However, performance of the bubble column reactor for methyl esterifcation of free fatty acids has not yet been revealed. Therefore, we studied effects of reaction temperatures (200, 225, and 250°C) on the composition of reaction product, conversion of the reaction and the reaction rate constant under a semi-batch mode of operation with oleic acids as free fatty acids. The activation energy and the frequency factor values of the methyl esterification reaction obtained in this experiment were 24.8 kJ/mol and 2.9, respectively. Compared with the obtained results of the transesterification of triglycerides, the reaction rate of methyl esterification of free fatty acids at the same reaction temperature (250°C) was higher than the former, but the quality of the product (the methyl ester content in the gaseous product) was lower.抄録全体を表示PDF形式でダウンロード (438K)
Environment
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Kai Huang, Kedar Nath Ghimire, Katsutoshi Inoue, Keisuke Ohto, Hidetak ...原稿種別: Research Paper
2007 年 40 巻 9 号 p. 786-791
発行日: 2007/09/20
公開日: 2007/09/20
ジャーナル 認証ありThe leaching kinetics of cadmium from scallop waste in dilute sulfuric acid was investigated by examining the effect of temperature (293–333 K), pH (1.5–2.5), and particle size on the leaching rate. The kinetics of the cadmium extraction process with intraparticle diffusion was reasonably interpreted according to the shrinking core model as a rate-determining step in accordance with the value of the activation energy, 15.9 kJ/mol. Increasing temperature, and decreasing pH and particle size positively influence the extraction of cadmium from the uro.抄録全体を表示PDF形式でダウンロード (477K)
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