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Volume 37 (2011)
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Volume 37, Issue 3
Displaying 1-13 of 13 articles from this issue
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Editorial Note
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2011 Volume 37 Issue 3 Pages edit_3
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL RESTRICTED ACCESSDownload PDF (170K)
Transport Phenomena and Fluid Engineering
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Akiomi Ushida, Tomiichi Hasegawa, Hiroshige Uchiyama, Takatsune NarumiArticle type: Research Papers
Subject area: Transport Phenomena and Fluid Engineering
2011 Volume 37 Issue 3 Pages 203-210
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL RESTRICTED ACCESSWhile many studies have been conducted on the flow properties of visco-elastic and complex fluids, most have conducted shear flows, for example, Poiseuille flow. Among the few studies on elongational flows, so-called Newtonian fluids have been reported to show elasticity in orifice flows. In the present research, slit flows were examined by measuring jet thrusts and pressure drops for water, macromolecular fluids, and aqueous solutions of various surfactants. For water, it was found that the measured values were lower than those predicted the Navier-Stokes equation for slit lengths of less than 68 μm. Elongational stress estimated from jet thrusts and pressure drops was almost equal to the past results and dependent on mean velocity. Also, gradient in elongational stress plotted against mean velocity was about 2.1. For aqueous solutions of surfactants, the results differed according to their polarity. Cationic surfactant caused the biggest decrease from the predicted values, followed by nonionic surfactant. Anionic surfactant gave the same results as water. These effects were attributed to a liquid–solid surface phenomenon. For macromolecular fluids, viscoelastic effects caused marked decreases from predicted values, as has been reported previously.View full abstractDownload PDF (1359K) -
Yoshiro InoueArticle type: Research Papers
Subject area: Transport Phenomena and Fluid Engineering
2011 Volume 37 Issue 3 Pages 211-222
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL RESTRICTED ACCESSThe pattern of time-dependent laminar fluid mixing without molecular diffusion is uniquely determined when the velocity vectors are known. Therefore, the exact mixing pattern can, in principle, be calculated by integration of the velocity vectors with respect to time. Even if the flow is laminar, however, it is extremely difficult to recognize the mechanism of fluid mixing and the overall physical and geometrical image of a complex flow field in a three-dimensional agitated vessel. On the other hand, it is known that laminar fluid mixing in an agitated vessel proceeds following the template made by the streakline growing from the tip of a paddle blade. In this paper, we propose the new mixing model based on the streakline and the mapping on it. This mixing model provides clearer physical images than the ordinary mixing model based on pathlines and clarifies the relation between the time-invariant structure behind the mixing fluid field and the time-variable properties in the mixing pattern that change following the invariant rule.View full abstractDownload PDF (3673K)
Separation Engineering
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Shota Maeda, Kuniko Kuroki, Kaoru Ohe, Tatsuya Oshima, Yoshinari BabaArticle type: Research Papers
Subject area: Separation Engineering
2011 Volume 37 Issue 3 Pages 223-228
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL RESTRICTED ACCESSBioethanol for fuel is a renewable alternative to petroleum, but because it is generally separated and concentrated by distillation, much energy is necessary to produce ethanol with a low water content due to the azeotropic point between ethanol and water. To develop an environmentally friendly method for purification of bioethanol, we examined its adsorption on hydrophobic zeolites. The adsorption properties of ethanol at 303 K and the effect of zeolites on the proliferation and fermentation of yeast at 301 K were investigated. The specific surface areas of zeolites were found to be 300–800 m2 g−1 by the N2 gas adsorption method. The N2 adsorption/desorption isotherms on zeolites were of type I (micro pore), III (atreto) and IV (meso pore). The adsorption rate of ethanol on zeolites in powder form reached equilibrium within 0.5 min, and the adsorption isotherm of ethanol on zeolites from aqueous solution was of the Freundlich type. It was found from the adsorption results that adsorption capacities of ethanol on zeolites were influenced by hydrophobicity, micropore size and percentage of micropore volume of zeolites. The highest adsorption capacity for 5 vol% ethanol was 90 mg g−1 using the commercial zeolite HISIV-3000, which indicates that the molecular diameter of ethanol fit the micropore size of the zeolite. An increase of proliferation and fermentation ability was observed with pellet zeolites because yeast adhered to the pellet zeolites.View full abstractDownload PDF (1578K) -
Hironobu Imakoma, Keiji Tsubota, Takafumi HorieArticle type: Research Papers
Subject area: Separation Engineering
2011 Volume 37 Issue 3 Pages 229-234
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL RESTRICTED ACCESSThe possibility of estimating the quality of dried material from the conductive drying rate curve was investigated, taking the binder segregation in a porous slab as an indicator of quality. A new binder segregation model was proposed for conductive drying of a porous slab by expansion of the authors' previous model for convective drying. Results calculated with the proposed model from a measured drying rate curve showed satisfactory agreement with the authors' previous experimental results using polyvinyl alcohol aqueous solution as the binder.
The success of the proposed model in reproducing the experimental results obtained under limited conditions suggests the possibility of developing a general model for binder segregation during conductive drying and may also be an example of the possibility of estimating the quality of dried material from the drying rate curve, which is necessary for the design of drying equipment.View full abstractDownload PDF (791K) -
Hironobu Imakoma, Keiji Tsubota, Takafumi HorieArticle type: Research Papers
Subject area: Separation Engineering
2011 Volume 37 Issue 3 Pages 235-240
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL RESTRICTED ACCESSA new binder segregation model incorporating solution diffusion was proposed for convective drying of porous solid without shrinkage by expansion of the authors' previous model without diffusion. Results calculated with the new model revealed that the assumption of negligible diffusion in the previous model was quantitatively appropriate for the previous experimental results, and that the diffusion caused a relaxation of binder segregation. The binder segregation curve calculated with the new model was only valid when the drying rate curve was known. When the drying rate curve was unknown, the range in which the influence of diffusion was negligible could be obtained by use of the “solution diffusion parameter” introduced in this study.View full abstractDownload PDF (675K) -
Takehiro Yamaki, Yasuhiko Suzuki, Keigo Matsuda, Masahiro Shishido, Ko ...Article type: Notes
Subject area: Separation Engineering
2011 Volume 37 Issue 3 Pages 241-245
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL RESTRICTED ACCESSA model for an internally heat-integrated batch distillation column (Batch or Semi-batch HIDiC) was developed, and the separation of a benzene-toluene binary mixture was simulated. The applicability of the model was examined by using the commercial process simulator Aspen Plus Dynamics® to evaluate energy-saving performance and process time against the compression ratio and reflux ratio. The batch or semi-batch HIDiC model results were compared with the conventional batch distillation model. It was found that with the semi-batch HIDiC, the model has the potential to reduce process time and energy consumption more precisely than the conventional batch distillation model.View full abstractDownload PDF (864K) -
Eiji Iritani, Nobuyuki Katagiri, Yasuyuki SanoArticle type: Notes
Subject area: Separation Engineering
2011 Volume 37 Issue 3 Pages 246-250
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL RESTRICTED ACCESSThe performance of microfiltration of humic acid solution flocculated with PACl (polyaluminum chloride) was evaluated by the average specific cake resistance αav determined from the variation of the reciprocal filtration rate with the filtrate volume per unit membrane area. When PACl was added in excess to the solution at pH 5, αav increased remarkably due to the redispersion of flocs. On the basis of the results of the initial transmission of flocculated humic acid through the syringe filter, it was inferred that αav increased due to the increase in the quantity of submicron particles generated by the redispersion of flocs. This suggests that the measurements of the initial transmission by the syringe filter test may be utilized as a simplified method to test flocculation-microfiltration performance. Flocculation at pH 7 and the addition of bentonite to the solution improved the performance of microfiltration of humic acid solution flocculated with PACl by extending the range of PACl concentration in which flocs did not redisperse.View full abstractDownload PDF (926K)
Thermal Engineering
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Kotaro Yasumura, Yasuhiro Saito, Masakazu Shoji, Yohsuke Matsushita, H ...Article type: Research Papers
Subject area: Thermal Engineering
2011 Volume 37 Issue 3 Pages 251-260
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL FREE ACCESSA simulation of spray flow around a high-speed rotary bell-cup was carried out in order to determine the dominating factor decreasing the transfer efficiency. The effect of the inner re-circulation flow and the ghost on the transfer efficiency was numerically investigated by a detailed comparison of adhering and non-adhering droplets. The spray flow was calculated based on the Euler–Lagrangian approach, including the standard κ–ε turbulence model. It was found that the inner re-circulation flow tends to draw in small droplets, and that droplets located at inner side of radial direction tend not to adhere to the target. The ghost is composed of large droplets. In the ghost, the adhering and non-adhering droplets have different trajectories. These findings indicate that the inner re-circulation flow and the ghost have a large effect on small and large droplets, respectively. The location of droplets in the inner re-circulation flow or the ghost is important for the transfer efficiency.View full abstractDownload PDF (2609K) -
—Sodium Acetate Trihydrate—Terumi Inagaki, Genki KitazawaArticle type: Research Papers
Subject area: Thermal Engineering
2011 Volume 37 Issue 3 Pages 261-270
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL RESTRICTED ACCESSThe thermo-physical properties of the phase-change latent heat storage material sodium acetate trihydrate were elucidated in order to examine its temperature dependency and supercooling phenomenon. Heat transfer by natural convection was also investigated in a horizontal enclosed rectangular container filled with sodium acetate trihydrate which was heated at the lower surface heating and cooled at the upper surface. The supercooling of sodium acetate trihydrate was clearly influenced by the cooling rate, and two kinds of supercooling phenomena were found. It was also found that the heat transfer coefficient of the liquid phase coincides well with the conventional heat-transfer correlation of natural convection heat transfer in a horizontal enclosed rectangular container by applying the values of thermo-physical properties obtained in the present work.View full abstractDownload PDF (4401K)
Biochemical, Food and Medical Engineering
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Hidetsugu Ueoka, Yuji Komizu, Koichi Goto, Ryuichi UeokaArticle type: Research Papers
Subject area: Biochemical, Food and Medical Engineering
2011 Volume 37 Issue 3 Pages 271-276
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL RESTRICTED ACCESSInhibitory effects of extracts from fruits and fruit juices of Citrus unshiu Marc. (Unshiumikan) encapsulated in hybrid liposomes (HL) composed of L-α-dimyristoylphosphatidylcholine (DMPC) and polyoxyethylene(20) sorbitan monooleate (Tween 80) on the growth of tumor cells were examined in vitro. The extracts with lower polar solvents significantly inhibited the growth of human hepatoma (HuH-7) cells and human stomach cancer (MKN-45) cells, though the extracts with higher polar solvents showed no or little antitumor activity. These results suggest that hydrophobic antitumor compounds are present in fruits and fruit juices of Unshiumikan.View full abstractDownload PDF (2336K)
Energy
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Tsuyoshi Yamamoto, Takuya Kuwahara, Koichi Nakaso, Takahisa YamamotoArticle type: Research Papers
Subject area: Energy
2011 Volume 37 Issue 3 Pages 277-283
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL RESTRICTED ACCESSHeat transfer techniques involving phase a change process are likely to play an important role in industrial devices that require the ability to remove high heat quickly. In the present work, fine mist cooling as a high heat removal technology was applied to the cooling of high temperature work material. A three-dimensional numerical simulation was developed to investigate the behavior of water particles and temperature of work material. The calculated results were in reasonably good agreement with experimental results for cooling performance of fine mist. It was found that about 50% of mist particles collide with the work material, and 20–30% of these particles evaporate after collision.View full abstractDownload PDF (1544K)
Environment
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Yoshiro Maki, Junji Shibata, Norihiro MurayamaArticle type: Research Papers
Subject area: Environment
2011 Volume 37 Issue 3 Pages 284-288
Published: May 20, 2011
Released on J-STAGE: May 24, 2011
JOURNAL RESTRICTED ACCESSThe contaminated soil used in this study was prepared by adding heavy metals to non-contaminated soil. The heavy metals chosen were Pb, Cd and Cu, because they are potential contamination sources used in components, printed circuit boards and soldering materials in electrical and electronics industries. The chelating agents selected were citric acid and N,N-dicarboxymethyl glutamic acid tetrasodium salt (GLDA), which were used alone and mixed together in order to examine purification of the contaminated soil. It was found that by mixing the soil and the chelating agent, soil purification is completed with a smaller amount of the chelating agent. Reaction in the ball mill proceeded quickly, reaching equilibrium in about 15 min. A flowchart was produced for soil purification in the mill: leaching in the mill, filtration, and washing with water. Treatment of the washing water, which contains heavy metals and chelating agent, was then examined. It was found that sulfide precipitation is a suitable method to remove heavy metals from the waste solution containing chelating agents and heavy metals.View full abstractDownload PDF (878K)
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