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HARUO YAMASHITA, MANABU YAMAGUCHI, MANPEI KANEDA, HIDEO NODA
1998 Volume 24 Issue 5 Pages
711-715
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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A novel multistage mixer-settler extraction column is developed in which the heavy phase accumulates on the stator owing to upward projection on the edge of the opening of the stator ring. The effects of the flow rate of the dispersed, continuous phases, the impeller speed on the dispersed phase holdup, and the flooding behavior are investigated experimentally to establish column operation in a system dispersing the heavy phase into the light phase. The hydrodynamic characteristics are also investigated experimentally to examine the flexibility of the equipment in a system dispersing the light phase into the heavy phase.
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TAIZO HANAI, KAZUNORI ANDO, HIDEKI NOGUCHI, HIROYUKI HONDA, CHIYO TAKA ...
1998 Volume 24 Issue 5 Pages
716-721
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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A new selection method for exterior tiles was investigated, in which three colors (standard, light and dark colors) could be decided from the desired images of consumers. FNN (fuzzy neural network) models deciding the standard color and the light and dark colors from sensory evaluation were constructed. Accuracy estimated by the FNN model for the standard color was about 90%, and for that the light and dark colors was about 88%. This selection method is be a promising approach for the direct decision of exterior tiles matching with the image of consumer.
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YUJI YOKOTA, SHIGENOBU TANAKA, ISAO YUMOTO, TETSURO KUSAKABE, MIKIO MO ...
1998 Volume 24 Issue 5 Pages
722-725
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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L-lactic acid was produced by direct fermentation of potato using
Lactobacillus amylophilus which has both the ability to saccharify starch and produce L-lactic acid. Potato was found to be a more suitable fermentation substrate compared to purified potato starch. It is estimated that protein and oligosacchalide which are contained in potato contribute as fermentation promoters. The utilization of squid entrails or scallop entrails as culture nutrients instead of polypeptone and yeast extract is extiemely successful. In particular, fermentation in squid entrails is strongly promoted, and is considered to come from enhancement of saccharification ability of
Lactobacillus amylophilus.
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EIJI NAKANISHI, KAZUFUMI KITAMURA
1998 Volume 24 Issue 5 Pages
726-731
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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When studying the environment assessment of recycling of used plastics products, the following two problems must be overcome ; how to specify the environmental loads on the used plastics products under consideration, and how to assess the environment loads emitted on recovering and processing of used plastics products. In this paper, a new concept for the first problem is presented for the purpose of promoting recycling while a trial model relating environmental load emitted and recycle ratio are proposed for the second problem. Based on the concept and model, an environmental assessments of closed recycling of used PSP (polystyrene paper) trays to pellets, and of an open recycling of PET (polyethylene terephthalate) bottles to carpets are investigated.
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HISAO ITOH, AKIO NISHI, MASAYOSHI NARUSE
1998 Volume 24 Issue 5 Pages
732-736
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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Ion exclusion chromatography for the purification of L-glutamine is studied. L-glutamine is usually produced by fermentation and used in pharmaceuticals. By using a model solution of L-glutamine and L-glutamic acid, the optimum cation exchange resin is examined. As a result of the experiments, it is found that a cation exchange resin which has smaller crosslinkage and smaller diameter is better. Ammonium sulfate, L-glutamic acid and pyrrolidonecarboxylic acid, which are usually contained in fermentation broth as impurities, are effectively separated by this method. Moreover, the experimental data of the chromatography is expressed fairly well by the differential equations which express the mass transfer in the fixed bed.
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TOSHIYUKI NONAKA, YASUO OHAMA, YOSHIYUKI YAMASHITA, MUTSUMI SUZUKI
1998 Volume 24 Issue 5 Pages
737-743
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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The behavior of viscous fingering in a Hele-Shaw cell under various gravity-levels was investigated using the drop shaft of the Japan Microgravity Center (JAMIC) and our high-gravity generator.
When silicone oil was displaced by aqueous solution of potassium citrate through a rectangle Hele-Shaw cell which was made of two plane-parallel acrylic plates, a wave of the unstable horizontal interface between the two fluids was observed to take the form of viscous fingers.
The wave number of viscous fingers decreased as the gravity level grew higher. It is confirmed that the experimental results of the wave number agreem with the prediction by a linear stability analysis, and that gravity tends to reduce the growth rate of the finger pattern if the density of the fluid with lower viscosity is greater than that of the fluid with higher viscosity.
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Development of System and Measuring Method
YUKIHIRO SAIKI, ETSURO YAMADA
1998 Volume 24 Issue 5 Pages
744-751
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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For gel-like or solid food products which contain suspended particles, heating or cooling processes cannot always achieve convection heat transfer. The authors have established a basic measuring method for thermal diffusivity α, which is important for heat processing of this unsteady zone, by the Hot-wire method.
With this measuring method, a calibration curve is drawn between τ
1/2 (the half time for Δ
T required to achieve a quasi-steady condition) and the themal diffusivity α. Separately, a “
Time-Temp. difference” curve is created using developmental measuring equipment for a sample with unknown thermal diffusivity α. This curve is used to calculate τ
1/2. From the above calibration curve, the thermal diffusivity α of the unknown sample can be obtained.
The non-dimensional effective thermal diffusivity obtained by this method matchs closely with values obtained by previous researchers.
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HISAO INAMI, MASAFUMI MOCHIZUKI, TAKASHI AKEHATA
1998 Volume 24 Issue 5 Pages
752-758
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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Pyrolytic gasification of polyethylene (HDPE) by partial combustion is carried out in a porous alumina fluidized bed 57.5 mm in diameter and 600 mm in length for the purpose of reusing plastic wastes. Attainment of steady state is confirmed under conditions of 30 to 240 min of feedtime of HDPE. Operating conditions, such as feed rate of HDPE and amount of alumina for efficient gasification, are studied experimentally. Gasification by a porous alumina fluidized bed is characterized by cleanliness due to less formation of soot. The real-time measuring of pressure drop through the fluidized bed is found to be practical to confirm attaining the steady state because when pressure drop through the fluidized bed becomes constant, the mass balance of carbon is closed. Although the bed temperature is constant within 30 min., the runs are non-stationary since pressure drop through the fluidized bed continues to increase. It seems likely that some carbonaceous substances occupy the porous portion of the alumina in the steady state of this gasification operation.
The optimum condition to give both a product gas of high lower heat value and a tolerable amount of oil and char is found to be an air ratio of 0.2 to 0.3 and a bed height/column diameter ratio of 1.0 to 1.5.
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SHINICHI YUU, KENJI NAKASHIMA, TAKAHIRO HIRA
1998 Volume 24 Issue 5 Pages
759-765
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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In this study, a large eddy simulation is used to calculate three-dimensional high Reynolds number free jet flow (
Re=1.0 × 10
4). The fifth-order upwind finite difference scheme and second-order Runge-Kutta method are used for the convective terms and the time developing term, respectively. For the other terms in the basic equations, a second-order central finite difference scheme is adapted. Since the nozzle aspect ratio is 10.0 (limitless length slit is simulated using periodic boundary condition), and the flow field ranges from the nozzle exit to the developed turbulent region, it seems that this is the largest-scale numerical analysis of the jet reported to date. The calculation is from early unsteady-state (air starts at the nozzle outlet) to steady-state (turbulence characteristics become stationary), considering turbulence unsteady motion. Calculated results are in fairly good agreement with experimental data for turbulent characteristics and power spectra. Simulation results are visualized by iso-vorticity and isoturbulence enegy contour plots which show structures of turbulence jet. It may be concluded that the large eddy simulation describes well the turbulence characteristics in a high Reynolds number free jet which are important for various engineering systems.
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LI BAO, YOSHIO OTANI, NORIKAZU NAMIKI, JISAKU MORI, HITOSHI EMI
1998 Volume 24 Issue 5 Pages
766-771
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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Estimation of particle penetration through HEPA (High Efficiency Particulate Air) filters with the conventional filtration theory requires accurate measurements of average fiber size and variance of fiber diameters. However, it is not an easy task to obtain these properties because fiber size distribution varies to a large extent from point to point in a HEPA filter. In the present work, measurements of representative fiber size distribution from scanning electron micrographs of HEPA filter cross-section are performed and the particle penetrations are predicted with the measured fiber size distribution. They are compared with those from the conventional method (measurement from filter surfaces) and experimental data. As a result, even for filters with inhomogeneity factor δ
p<1 by the conventional method, the present method gave δ
p>1, suggesting that δ
p< 1 is caused by the failure in measurement for representative fiber size distribution. However, the improvement in prediction with more reliable filter properties is not satisfactory because the conventional filtration theory cannot account for the contribution of fine fibers properly. Introduction of bimodal fiber size distribution together with the measurement of fiber size distribution in a cross-section of a filter is found to give comparable prediction results with the conventional method without resorting the inhomogeneity factor of filter packing.
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YOSHIO OTANI, LI BAO, NORIKAZU NAMIKI, MAMORU HOSAKA, HITOSHI EMI
1998 Volume 24 Issue 5 Pages
772-778
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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The fiber size of HEPA (High efficiency particulate air) filters has been drastically decreased in the pursuit of higher collection performance, i.e., high collection efficiency and low pressure drop. The reduction of fiber size as well as the importance of collection of ultrafine particles has raised various problems in particle collection at extremely low Peclet numbers,
Pe. The present work focuses on clarifying the filtration problems at low
Pe by studying the collection characteristics of ideal model filters. The main findings of the present work are : (1) the log-penetration equation is not valid at low
Pe because single fiber efficiency in the vicinity of the filter surface is higher than the inside; (2) filter with a lower packing density has a higher collection performance for
Pe<1; (3) the single fiber efficiency of an inclined fiber can be predicted with the prediction equation for perpendicular fibers by defining based on the airflow velocity component normal to the fiber axis; and (4) the effect of inclined fibers on the particle penetration is not significant so the assumption of perpendicular fiber alignment to the main airflow can be introduced without loss in accuracy.
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HEE-JOON KIM, ICHIRO NARUSE, GUO-QING LU, KAZUTOMO OHTAKE, MITSUSHI KA ...
1998 Volume 24 Issue 5 Pages
779-783
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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The characteristics of self-denitrification in biobriquettes are studied experimentally. To enhance effective utilization of low-grade coals, and to control emission of environmental pollutants from combustion, a new artificial solid fuel, a biobriquette with a self-denitrification function, is developed. It was produced by the mixture of low-grade coal, cornstalk as biomass and pulp black liquid as denitrificazer under a high compression pressure condition. Both experiments of pyrolysis and combustion were performed in order to reveal the mechanism of nitrogen-oxide formation and denitrification of the biobriquette.
It is found that the release fraction of fuel-N is raised with increasing pyrolysis temperature in both coal and biomass. The release fraction of fuel-N in biomass is much higher than coal at the same pyrolysis temperature. The conversion fraction of fuel-N to NO slightly ascends and the fraction to N
2O slowly descends with increasing furnace temperature, but the sum of conversion fraction of fuel-N to NO and N
2O appears to be independent of furnace temperature. The denitrification process of the biobriquette with the pulp black liquid appears to proceed as two stages, namely the volatile combustion stage and the char combustion stage. Denitrification mainly happens in the char combustion stage. A denitrification efficiency of 40% can be obtained in the biobriquette combustion with a pulp black liquid of 10 mass%. Finally, it is confirmed for the first time that the pulp black liquid has significant denitrification capabilities in the biobriquette combustion.
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TOSHIMI TOKUI, MOTOTAKE YANO, KENJI ASAMI
1998 Volume 24 Issue 5 Pages
784-790
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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Formation of silica gel through hydrolysis and successive condensation of tetraethoxysilane (TEOS) is studied in the presence of NH
3 as a basic hydrolysis catalyst. The rate of hydrolysis of TEOS was determined by gas chromatography. Dependence of the hydrolysis rate on the initial composition of the reaction mixture is examined in detail; the rate showed first order kinetics for TEOS concentration, and the apparent reaction orders with respect to NH
3, and H
2O are estimated as 1.1, and 1.4, respectively. The particle diameter and numeric concentration of silica gel formed was measured by the dynamic light scattering method. A very narrow distribution of the particle diameter was observed during the growth, showing the formation of monodispersed silica particles. Simulation of the rate of particle growth using the kinetic data above reveals that the hydrolysis of TEOS is the rate determining step. Calculated values of numeric concentration of the particles are in good agreement with experimental values.
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SHIRO KIYOYAMA, KOICHIRO SHIOMORI, YOSHINOBU KAWANO, YASUO HATATE
1998 Volume 24 Issue 5 Pages
791-796
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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Preparation of biodegradable microcapsule using a poly lactic acid as wall material was performed by (W/O/W) emulsion solvent evaporation method. Fractional entrapment of the core material and the average diameter of the microcapsule are independent of the composition of the inner aqueous phase, such as salt concentration, pH and viscosity. On the other hand, by changing the salt concentration of the outer aqueous phase and the hold up of dispersion phase in the (W/O) emulsion, it is possible to increase the fractional entrapment of the core material with the increase in (W/O/W) emulsion stability and amount of wall material. The entmpment effect is controlled by preparation conditions.
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YOSHIRO KITAMURA, AKIHIRO MISHIMA, HIDETO MATSUYAMA, YORISHIGE MATSUBA
1998 Volume 24 Issue 5 Pages
797-802
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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Separation of oleic acid methyl ester/linolic acid methyl ester and oleic acid/linolic acid is carried out by membrane extraction with both hydrophilic and hydrophobic membranes. The hydrophilic and hydrophobic membranes used were hollow fiber types, and polar solution such as acetonitrile with 10 wt % water and organic solution such as heptane were fed inside the fiber and in the shell side, respectively. The polar solution containing unsaturated fatty acid methyl esters was fed to the center of the membrane extraction apparatus so that the apparatus had both an enriching section and a stripping section. By this feed method, higher membrane performances such as solute purity and recovery are obtained than in the case of feeding to the edge of the apparatus. When hydrophobic and hydrophilic membranes are used in the stripping and enriching sections, respectively, the superior membrane performances is obtained. Further, effects of flow rate of polar solution and the hydrophobic membrane length on themembrane performances are investigated. The membrane performances by this membrane extraction method are analyzed, and the calculation results are confirmed to be approximately in agreement with the experimental data.
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YOSHITOMO HANAKUMA, JUNZOU YAMAMOTO, EIJI NAKANISHI
1998 Volume 24 Issue 5 Pages
803-805
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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A method of detecting process abnormal signals using a recursive maximum likelihood method and Bayesian statistical inference has difficulty mselecting the order of an AR model. A method using process signals without trend ingredient by once differential method and Bayesian statistical inference has been developed. The method proposed in this study has the advantage of detecting online process abnormal signals in industrial use. It was applied to abnormal detection of the catalyst feed flow in a linear low-density polyethylene plant to confirm the design philosophy. The actual result indicates that the proposed method is effective in detecting abnormal process signals.
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KENJI FUKUCHI, TAKESHI FURUYA, YOSHITSUGI KIKKAWA, YASUHIKO ARAI
1998 Volume 24 Issue 5 Pages
806-809
Published: September 10, 1998
Released on J-STAGE: November 12, 2009
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A cubic equation of state is proposed to improve the calculation performance for liquid-phase densities. For the repulsive part, the Scott-I expression developed for hard sphere fluid is adopted and the attractive part proposed by Fuller is combined with the repulsive part. For typical binary systems, both vapor-liquid equilibria and saturated densities of vapor and liquid phases were calculated by the equation of state with the conventional mixing rule. Good agreement is found between calculated and experimental saturated liquid densities, as well as vapor-liquid equilibria, though a discrepancy is found in the calculation of liquid densities by SRK equation of state widely used.
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YUTAKA MATSUMOTO, MASAO SUDOH, YOSHIMI SUZUKI
1998 Volume 24 Issue 5 Pages
810-813
Published: September 10, 1998
Released on J-STAGE: February 19, 2010
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Electro-microfiltration of culture broth was studied to control the selective permeation of protein solute. A flat microfiltration membrane was sandwiched between two platinum electrode plates, between which a direct current was applied. Both model suspensions, including bovine serum albumin (BSA) in baker's yeast suspension and real culture broth producing lytic enzyme, were filtrated in cross-flow mode. The influences of the suspension pH and the intensity of the electric field on selective permeation of protein solute were studied.
When the electrode on the permeate side was used as a cathode, BSA was concentrated to the permeate solution because the BSA molecules was charged positively at pH 3.5. Meanwhile, the BSA was rejected at pH 7 because of the electric repulsion force between the molecule and the electrode of permeates side. The effects of electric field on the BSA permeability increased with the lower permeate flux, and the higher intensity of electric current. The electro-microfiltration of real culture broth also has similar properties in the filtration of the model suspension. It was clearly found that a selective permeation of protein solutes could be controlled by changing suspension pH.
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1998 Volume 24 Issue 5 Pages
e1a
Published: 1998
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1998 Volume 24 Issue 5 Pages
e1b
Published: 1998
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1998 Volume 24 Issue 5 Pages
e1c
Published: 1998
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1998 Volume 24 Issue 5 Pages
e1d
Published: 1998
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1998 Volume 24 Issue 5 Pages
e1e
Published: 1998
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