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Predecessor
Volume 41, Issue 1
Displaying 1-13 of 13 articles from this issue
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Editorial Note
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2015 Volume 41 Issue 1 Pages edit_1
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSDownload PDF (194K)
Transport Phenomena and Fluid Engineering
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Kenji Matsumoto, Mitsuhiro Ohta, Shuichi IwataArticle type: Research Paper
2015 Volume 41 Issue 1 Pages 1-10
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSNumerical simulations of flow dynamics of milk using a volume-of-fluid (VOF) method were carried out to understand detailed fluid mechanics of milk in a process in which milk was filled into a gable-top carton with the volume of 1000 mL. All physical properties of milk were measured, and it was verified that in its rheological properties, milk was a purely viscous non-Newtonian fluid with shear-thinning property. In the numerical simulation, the shear-thinning property of milk was modeled with the Carreau–Yasuda model, in which the operating condition for the milk-filling process was set as the computational condition. The numerical results showed that the viscosity of milk was drastically changed in the milk-filling process and that a complicated viscosity profile was formed inside the carton. By comparing numerical results of milk with those of Newtonian fluids, the characteristics of the flow dynamics of milk were more visible. Consequently, it was revealed that the shear-thinning property of milk largely influenced fluid flows inside the carton. Hence, the shear-thinning property of milk cannot be ignored in milk-flow simulations. Numerical analysis will be a useful tool for understanding local changes in the shear-thinning viscosity.View full abstractDownload PDF (3941K) -
Yoshihito Kato, Yoshiro Inoue, Masashi Hiramatsu, Shota OhtaniArticle type: Research Paper
2015 Volume 41 Issue 1 Pages 11-15
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSStreak line patterns of several wide-paddle impellers developed by mixer companies in Japan were observed from laminar to turbulent flow regions. The power consumption of all wide-paddle impellers examined was correlated by using the same correlations as in our previous work, but the mixing mechanism of these impellers in the laminar flow region changed greatly with the kind of impeller. It was found that these wide-paddle impellers had distinctive patterns of streak lines depending on the operation conditions. In particular, liquid height greatly affected the streak line pattern. Furthermore, it was found that the impeller Reynolds number was a parameter that controlled the streak line pattern.View full abstractDownload PDF (7948K) -
Yoshihito Kato, Masashi Hiramatsu, Shota Ohtani, Manami Yoshida, Katsu ...Article type: Research Paper
2015 Volume 41 Issue 1 Pages 16-20
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSThe streak line visualization method developed by Inoue et al. (2009) is effective for evaluation of mixing performance in the laminar flow region. In the previous work, the mixing mechanism of large paddle impellers that can be used over a wide range of viscosity was clarified based on this method. In the present work, the geometry of a new impeller that has good mixing performance was optimized based on streak line observation. The new impeller has (1) simple geometry, (2) speedy mixing performance, and (3) stable operating characteristics.View full abstractDownload PDF (7998K) -
Yoshihito Kato, Tomohiro Ito, Haruki Furukawa, Ryo Nagumo, Yutaka Tada ...Article type: Note
2015 Volume 41 Issue 1 Pages 21-24
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSThe Sanmeler, an impeller with asymmetric geometry developed by a Japanese company, can be used over a wide range Reynolds number from laminar to turbulent flow regions. Visualization of streak lines showed that their pattern spread quickly throughout the mixing vessel regardless of the liquid height, indicating that the Sanmeler had good mixing performance. The power consumption of the Sanmeler was correlated with simple modification of the correlations of other wide-paddle impellers.View full abstractDownload PDF (3717K)
Chemical Reaction Engineering
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Takuya Ito, Hideki Suganuma, Seiichi Suzuki, Shigeru Kato, Akimichi Ha ...Article type: Note
2015 Volume 41 Issue 1 Pages 25-28
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSPressure drop and transfer rate of wood powder pellets were measured using a cold model of a horizontally rotating cylinder with two pairs of internal screw cylinders. The transfer rate was one order of magnitude smaller than that when the pellets are moved along by a screw movement, which indicates their flow over the central shaft of screw cylinders. Using internal cylinders of simple design, the operational range showing good gas-solid contact was narrow. Modification of the internal cylinders with partial cover of the entrance sides allowed high packing of pellets with good gas-solid contact and stable pressure drop.View full abstractDownload PDF (595K)
Process Systems Engineering and Safety
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Ippei Kimura, Hiromasa Kaneko, Kimito FunatsuArticle type: Research Paper
2015 Volume 41 Issue 1 Pages 29-37
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSPID controllers and model-predictive controllers are widely used for process control. However, optimization of control parameters is complicated and many processes are operated inefficiently. In order to perform more effective control, we propose a new process control method using soft sensor models. We refer to this method as inverse soft sensor-based feed-forward (ISFF) control. Soft sensor models are constructed between a controlled variable (y) as an objective variable, and manipulated variables (U) and other process variables (X) as explanatory variables. The optimal control strategy of U which optimizes the objective function including y is determined with inverse analysis on the soft sensor models while considering X variables. The proposed method was applied to the change of a set point of a simulated CSTR system, and the validity of ISFF was confirmed.View full abstractDownload PDF (1885K)
Biochemical Food and Medical Engineering
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Kounosuke Hayashi, Yusuke Tomozoe, Kenji Nagai, Kyoichi Matsuba, Masay ...Article type: Research Paper
2015 Volume 41 Issue 1 Pages 38-42
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSNew fusion proteins for immunoassay were developed as an alternative to the conventional chemical linked enzyme-antibody complex. Human chimeric alkaline phosphatase (IPP) was used as the labeling enzyme, and partial domains of Staphylococcus aureus Protein A and Streptococcus Protein G were used as antibody binding protein (PG). The fusion protein composed of IPP and PG was produced using human cell lines because IPP is derived from human enzymes. The expression system was optimized by changing the plasmid vector, reducing the GC content of the DNA sequence, and employing different cell lines including adherent and suspension cells. As result, a 2,600-fold increase in the protein yield per unit of growth medium was achieved. The resultant IPP-PG fusion protein was successfully utilized for immunoassay applications such as western blotting and immunohistochemistry.View full abstractDownload PDF (2569K)
Materials Engineering and Interfacial Phenomena
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Hiroki Yano, Hitomi Sugiyama, Tsutomu Sawada, Toshimitsu KanaiArticle type: Research Paper
2015 Volume 41 Issue 1 Pages 43-47
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSWe prepared colloidal crystals immobilized in copolymer hydrogel films composed of N-isopropylacrylamide (NIPAM) and N-methylolacrylamide (NMAM) at various mixing ratios and examined the dependence of the degree of swelling and optical stop-band wavelength on ethanol concentration. Colloidal crystals immobilized in NIPAM-rich gels shrank considerably at low ethanol concentrations owing to the cononsolvency of NIPAM in the solvent. The optical stop-band wavelength changed significantly according to the change in the degree of swelling. In contrast, colloidal crystals immobilized in NMAM-rich gels shrank considerably at high ethanol concentrations owing to the nonsolvency of NMAM, resulting in a large shift of the stop-band wavelengths to lower values. These materials also exhibited thermosensitivity and are therefore potentially useful as tunable photonic crystals controlled by multiple stimuli and as sensors for detecting changes in a specific environment.View full abstractDownload PDF (2772K)
Energy
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Keigo Matsumoto, Keiji Takeno, Yoshito Oshima, Makoto KobayashiArticle type: Research Paper
2015 Volume 41 Issue 1 Pages 48-54
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSTo utilize the area contaminated by radiation following the accident at Fukushima-Daiichi nuclear power plant, a case study was conducted of biomass gasification and gas engine system with the energy crop Erianthus grown in the area. The distribution of radioactive cesium in ash and gas components was estimated by the tube type lab-scale gasification test and the equilibrium calculation. As a result, the transfer ratio of cesium to the gas phase by gasification was lower than that by combustion because of less CsNO3 generation. Moreover, Erianthus grown in an area with less than approximately 9 million Bq/m2 can be treated as normal biomass fuel. According to the feasibility study, biomass gasification system is economically feasible. According to the feasibility study, a biomass gasification system was shown to be an effective way of utilizing the radiation-contaminated area of Namie-machi, Fukushima where flat agricultural land exists.View full abstractDownload PDF (814K)
Environment
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Nobusuke Kobayashi, Kento Nakayama, Satoshi Tachibana, Yasuhiro Tanabe ...Article type: Research Paper
2015 Volume 41 Issue 1 Pages 55-61
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSHydrothermal treatment of sludge at 453–513 K and continuous filtration of the treated slurry at the same temperature were carried out, and the concentrations of organic acid, TOC, TON, ammonia, TOP and other components in the filtrate were measured. Filtration at normal temperature was also conducted for comparison. The concentration of organic acid in filtrates varied depending on the treatment temperature, and acetic acid significantly increased in the continuous filtration. Although ammonia concentration was increased by the hydrothermal treatment, the increase could be inhibited by controlling the reaction temperature and time. Phosphorus concentration in the filtrate was not affected by operating conditions, and phosphorus compounds in sludge were found to be concentrated in the solid residue by the hydrothermal treatment.View full abstractDownload PDF (773K) -
Toshiyuki Iwasaki, Shigeru Kato, Yoichi Kodera, Akimichi Hatta, Masahi ...Article type: Research Paper
2015 Volume 41 Issue 1 Pages 62-66
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSThermal decomposition experiments of woody wastes contaminated with radioactive materials were conducted using an externally-heated horizontal kiln in the work area for segregation of disaster wastes at Hirono Town, Futaba County, Fukushima Prefecture. Radioactivity was not detected in gaseous products of thermal decomposition at 923 K and 1123 K after passage through a trap filled with activated carbon. The contents of radioactive cesium (134Cs and 137Cs) were measured in the solid and liquid products of the thermal decomposition experiments and in the residues in the kiln after all of the experiments. Although a trace amount of radioactive cesium was found in the washing trap during the start-up period of operation at 923 K, most of the cesium remained in the char, including the residues in the kiln. These results suggest that most of the radioactive cesium is trapped in char particles and is not emitted in gaseous form.View full abstractDownload PDF (683K) -
Junji Shibata, Norihiro Murayama, Takeshi Masui, Shintaro Yao, Toshihi ...Article type: Research Paper
2015 Volume 41 Issue 1 Pages 67-71
Published: January 20, 2015
Released on J-STAGE: January 20, 2015
JOURNAL RESTRICTED ACCESSThe effects of adding coal fly ash-derived zeolites on the physical properties of mortar such as compressive strength and voidage and on the repression of efflorescence by cation exchange were investigated. It was confirmed that efflorescence can be repressed by adding zeolites to mortar, and especially remarkable repression was observed when 10% or more of the Al-P (Al3+-containing zeolite P) was added. The main mechanism of the repression was thought to be the filler effect of zeolites on voids in mortar, suggesting that the movement of Na2SO4 solution in the mortar can be controlled by this effect.View full abstractDownload PDF (912K)
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