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Setsuko Akakabe, Hiroyuki Ishii, Kazuhiro Hoshino, Shoichi Morohashi, ...
1995 Volume 28 Issue 6 Pages
651-655
Published: 1995
Released on J-STAGE: March 26, 2005
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The distribution ratios of copper(II) ion between an aqueous solution containing mixtures of Cu(NO
3)
2-HNO
3-KNO
3, at various pH and the organic phase containing bathocuproine(L) in 1,2-dichloroethane were measured. From the variation in the absorption spectra, it was found that the ligand is distributed between both phases by forming HL
+ in the aqueous phase and HLX in the organic phase, respectively, in the range of pH from about 1 to 5.5. The extractability of copper(II)-complex, CuL
2(NO
3)
2, decreases rapidly with the decrease in pH value of the aqueous solution. As a result, it became clear that the effect of hydrogen ion on the distribution ratio can be utilized for the concentration and separation of copper(II) ion through a liquid membrane between both aqueous phases of Cu(NO
3)
2 at different pH.
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Yasuo Hatate, Yoshimitsu Uemura, Kazuya Ijichi, Yoshio Kato, Tadashi H ...
1995 Volume 28 Issue 6 Pages
656-659
Published: 1995
Released on J-STAGE: March 26, 2005
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Monodispersed porous polystyrene beads crosslinked with divinylbenzene were prepared by
in situ polymerization. For this objective, the preparation of uniform oil microdroplets in water was successfully achieved by using a Shirasu Porous Glass (SPG) membrane emulsifier (POEM® from Reika Kogyo Co. Ltd.). Separation abilities for a gel permeation chromatograph (GPC) column were discussed with polymer microbeads obtained by changing key experimental factors such as the pore sizes of the SPG membrane and diluents. Consequently, it was evident from gel permeation chromatography that the porous beads prepared by SPG emulsification can be used for the effective separation of a molecular weight range of 10
2 to 10
6.
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Susumu Nakamura, Kouji Oguma, Yoshiro Ito
1995 Volume 28 Issue 6 Pages
660-665
Published: 1995
Released on J-STAGE: March 26, 2005
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Recovery of uranium from natural seawater by a circulating fluidized-bed adsorber (CFBA) was carried out using an organic adsorbent-a granular amidoxime resin (AOR). In the adsorption experiments, stability of the circulating fluidized state of adsorbent and uranium uptake were measured as a finiction of adsorption time. Results were compared with those obtained for a typical inorganic adsorbent-hydrous titanium oxide granulated with polyacrylonitrile (PAN-HTO). The circulating fluidized state of AOR was very stable. The total amount of carried-over adsorbent was small enough for an adsorption period of 216 hours. The uranium adsorption rates of AOR increased linearly up to the adsorption time of 100 hours, but the increase rate decreased slightly after this time. The uranium amount adsorbed per unit weight of AOR was larger than that of PAN-HTO. The effect of contacting section height of the CFBA on the uranium uptake was also discussed.
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Wei-Ming Lu, Chih-Ming Lan, Hsu-Wei Fang
1995 Volume 28 Issue 6 Pages
666-672
Published: 1995
Released on J-STAGE: March 26, 2005
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A positive temperature coefficient thermister is devised as a thermal probe to determine local heat transfer coefficients in a stirred vessel with a standard Rushton turbine impeller. The effects of aeration and flow patterns on the value of local heat transfer coefficients are discussed. Under most operating conditions, the highest flux is found at the impeller discharge region and the front side of the baffle plates. The mean Nusselt number for jacket and baffle type heat exchange elements is presented in terms of the modified Reynolds number and the other dimensionless groups, as the results of the integration of the determined values of local heat transfer coefficients.
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Takumi Kinugasa, Yuri Ono, Yuko Kawamura, Kunio Watanabe, Hiroshi Take ...
1995 Volume 28 Issue 6 Pages
673-678
Published: 1995
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Extraction of lithium ion from aqueous alkaline media by a liquid surfactant membrane was performed using a mixture of LIX54 and TOPO as the extractant. Stripping of lithium from the kerosene solution to the acid solution was suppressed with increasing content of polyamine (ECA) surfactant. The extraction rate of lithium by the liquid membrane could be interpreted taking account of an interfacial resistance due to ECA. It was confirmed that swelling of the (W/O) emulsion drops by water permeation through the liquid membrane is evaluated in terms of a change in osmotic pressure gradient between the external and internal aqueous phases during the lithium extraction. In the present operation, the extraction ratio of Li
+ from the external feed and the uptake into the internal phase reached as high as 95%.
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Akira Ito, Kouji Adachi, Yan Feng
1995 Volume 28 Issue 6 Pages
679-683
Published: 1995
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A vapor permeation process for aromatics separation from a hydrocarbon mixture was studied by means of the simultaneous permeation of dimethylsulfoxide vapor as an agent for membrane swelling and preferential permeation of aromatics. The separation performance of the process was demonstrated by a polyvinylalcohol membrane for mixed vapors of benzene/cyclohexane, xylene/octane and a model gasoline. The aromatic vapors preferentially permeated from these mixed vapor feeds. The separation factor was over 10. The separation mechanism of the process mainly depends on the relative solubility of the vapors between aromatics and other hydrocarbons in dimethylsulfoxide.
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Mohammed Zohdi Anabtawi
1995 Volume 28 Issue 6 Pages
684-688
Published: 1995
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Gas holdup in highly viscous fluid in two phase spouted bed operated continuously with respect to the gas flow and batchwise with respect to the liquid was investigated using bed expansion technique. Experiments were carried out in three cylindrical spouted beds having diameters of 74 mm, 114 mm and 144 mm and height of 1000 mm under the conditions of superficial gas velocities between 0.0018 m·s
–1 and 0.29 m·s
–1, liquid viscosities between 0.063 Pa·s and 0.320 Pa·s, six static bed heights of 0.12 m, 0.18 m, 0.24 m, 0.30 m, 0.36 m and 0.48 m, surface tension between 0.0248 N·m
–1 and 0.035 N·m
–1 and density between 906 kg·m
–3 to 928 kg· m
–3 using a single nozzle sparger of 10.0 mm diameter. A correlation for the gas holdup was presented, with maximum deviation of 9%. This correlation was compared with those available in the literature.
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Ali Al-Shawabkeh, Shi-Ying Lin, Hitoki Matsuda, Masanobu Hasatani
1995 Volume 28 Issue 6 Pages
689-696
Published: 1995
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The effect of temperature and O
2 concentration on the product distribution of the CaO-SO
2 reaction was thermogravimettically studied. The accompanied changes in pore characteristics (specific surface area and pore volume) with reaction temperature, time and O
2 concentration were also investigated. Among the sulfation products, CaSO
3 was found to be thermally stable at temperatures below about 973 and 1015 K with and without O
2, respectively.
Within CaSO
3 stability limits, O
2 presence increased the initial sulfation rate, but virtually suppressed SO
2-sorption capacity. On the other hand, at temperatures beyond CaSO
3 stability limits, O
2 presence improved the initial sulfation rate as well as SO
2-sorption capacity, and the reaction order with respect to SO
2 was determined to be around unity independent of O
2 presence.
Regardless of O
2 presence, the reaction order with respect to SO
2 was found to increase from 0.5 to 1.1 with temperature increase from 823 to 1123 K. No influence of O
2 concentration on the initial reaction rates and sorption capacities were observed above 2 vol% O
2 in the tested temperature range (823–1123 K). The temperature dependency of the CaO-SO
2 reaction system was correlated with an activation energy,
E, ranging between 31 and 51 kJ·mol
–1.
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Kazuaki Yamagiwa, Toshiya Sasaki, Satoshi Takesono, Akira Ohkawa, Okih ...
1995 Volume 28 Issue 6 Pages
697-702
Published: 1995
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The adsorption isotherm of the nonionic surfactant Triton X-100, tryptophan and BSA on temperature-sensitive poly(vinylmethylether) gel (PVMEG) was investigated for adsorptive separation of bio-related substances. The adsorbed amount of Triton X-100 on PVMEG was almost independent of pH, and comparable to that of commercial polymeric adsorbents. Tryptophan or BSA was hardly adsorbed on PVMEG. Triton X-100 was preferentially adsorbed on PVMEG from a mixed solution containing the three adsorbates. Temperature-swing adsorption of Triton X-100 was effectively carried out with a temperature span of 6 K. Adsorption and desorption rates were much accelerated by widening the temperature span. The high potentiality of separation of nonionic surfactant from bioproducts by temperature-swing adsorption with PVMEG was confirmed.
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Yoshinobu Kohara, Hiroshi Ueda, Eiji Suzuki
1995 Volume 28 Issue 6 Pages
703-707
Published: 1995
Released on J-STAGE: March 26, 2005
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In perfusion culture of mammalian cells, the cells should be separated from the spent medium and retained in the culture vessel. A possible cell separator for this purpose is a multiple inclined plate space in an agitated or air-circulated culture vessel. Local fluid velocity and cell concentration contours in an assumed hybridoma cell suspension, which was held stationary in such a gravitational cell settler consisting of multiple open-ended spaces partitioned by inclined plates, were estimated by numerically solving the momentum and continuity equations. The simulated maximum convection flow velocity was 20 times the Stokes’ velocity of the cells. The flow penetrated into the space below the lower ends of the inclined plates. The model estimated a larger cell settling rate than the Ponder-Nakamura-Kuroda (PNK) formula. In our experiment, the cell suspension of hybridoma 2E3 was held stationary in a vessel containing multiple inclined plates, and the position of the interface between the clear and turbid fluids was observed. The falling rate of the interface was larger than that predicted by the PNK formula. The model can be utilized for designing such cell separators for perfusion culture of suspended mammalian cells, including optimization of the size and interval of the plates.
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Shi-Ying Lin, Ali Al-Shawabkeh, Hitoki Matsuda, Masanobu Hasatani, Mas ...
1995 Volume 28 Issue 6 Pages
708-714
Published: 1995
Released on J-STAGE: March 26, 2005
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Sulfur capture reactions of CaCO
3-H
2S and CaO-H
2S have been investigated under various gaseous mixtures conditions using limestone and calcined limestone of 1 mm diameter in a thermogravimetric analyzer.
Sulfidation of limestone (CaCO
3-H
2S) had a very low initial reaction rate and final conversion than the sulfidation of calcined limestone (CaO-H
2S) due to its product layer having less porosity than those produced by calcined limestone. The products (CaS) produced by sulfidation of limestone have larger grain size and lower specific surface area than those produced by calcined limestone. Both suffidation reactions of limestone and calcined limestone were first order with respect to H
2S partial pressure. The presence of CO
2 inhibited both the initial reaction rate and final conversion of sulfidation of calcined limestone. This was explained by the fact that CO
2 accelerated sintering of CaO, and thus reduced the specific surface area of CaO. The initial sulfidation rate of limestone decreased linearly with increasing CO
2 partial pressure. The initial reaction rates of both limestone and calcined limestone decreased with increasing steam partial pressure. The effect of steam on final conversion of sulfidation of calcined limestone was found to be insignificant. Only with the presence of CO
2 was the sulfldation rate of calcined limestone appreciably reduced by H
2 addition.
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Hiroyuki Kawasaki, Hisaya Tanaka
1995 Volume 28 Issue 6 Pages
715-720
Published: 1995
Released on J-STAGE: March 26, 2005
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The effects of geometric properties such as diameter,
d, number,
n, and pitch,
p, for holes located on a perforated plate on gas holdup,
φ, in a bubble column were experimentally investigated while varying gas flow rate,
G, and unaerated liquid height,
Z0.
In the case of constant
Z0, the volume of the spouting section above the column bottom increased with increasing
d and decreasing
n and
p, and became negligible compared with that of the calming section at sufficiently large
Z0. As a result, the value of
φ based on the volume of the bubble bed Increased and approached that of
φC based on the volume of the calming section. The value of
φC was correlated to two parameters as a dimensionless expression. One was the flow parameter defined by a ratio of the reference velocities in the free and recirculated rising regions, and another was the distribution parameter for gas holdup in the recirculated rising region. Since the latter was strongly dependent on geometric properties for a perforated plate, its empirical expression was obtained as a function of the properties.
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Vicente Rodriguez, Carlos Lafuente, Felix M. Royo, Jose S. Urieta, Alb ...
1995 Volume 28 Issue 6 Pages
721-726
Published: 1995
Released on J-STAGE: March 26, 2005
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A dynamic recirculating still was employed to measure isobaric vapour-liquid equilibrium at 40.0 and 101.3 kPa for the binary systems 1,2-dibromoethane with 1-butanol, 2-butanol, 2-methyl-l-propanol and 2-methyl-2-propanol. The experimental data were tested for thermodynamic consistency and correlated with the Margules, Van Laar, Wilson, NRTL and UNIQUAC equations. All the systems show minimum temperature azeotropes, except 1,2-dibromoethane with 2-methyl-2-propanot at 101.3 kPa. Predictions with the UNIFAC method were also obtained.
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Tomoaki Minowa, Yutaka Dote, Shigeki Sawayama, Shin-ya Yokoyama, Masan ...
1995 Volume 28 Issue 6 Pages
727-731
Published: 1995
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The phase of a model garbage was changed from solid to liquid slurry by thermal liquidization for the purpose of easy handling. The garbage was prepared by mixing cabbage, boiled rice, boiled and dried sardine, butter, and the shell of short-necked clam, and its moisture content was 86.4 wt%. It was heated under a pressurized nitrogen atmosphere at 150, 200, or 250°C for 0.1 or 1 h with or without sodium carbonate as a catalyst (5% on a dry solid basis). In the liquidized garbage produced, the solid particles were suspended. Slight sedimentation of the particles was observed for the liquidized garbage obtained at 150 and 200°C, however the particles settled rapidly for the liquidized garbage obtained at 250°C. The liquidized garbage was regarded as a pseudo-plastic fluid from viscosity measurements, and the apparent viscosity decreased significantly with the reaction temperature.
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Satoshi Fukada, Hisanori Tsuru, Masabumi Nishikawa
1995 Volume 28 Issue 6 Pages
732-737
Published: 1995
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Rates of water frost growth in a vessel with a cooled horizontal plate were experimentally determined under reduced pressure atmospheres of hydrogen, helium, methane and nitrogen. The mass deposited on the cooled surface under each of the atmospheres was almost in proportion to time. The Sherwood number under the condition of no mist formation,
Sh0, in the atmospheres of methane and nitrogen was in good agreement with Cotton’s equation for natural convection between horizontal parallel plates.
Sh0 in a hydrogen atmosphere was unity, which corresponds to control by molecular diffusion in the stagnant gas. The tendency of the decrease in
Sh due to mist formation could be evaluated well by multiplying
Sh0 by a factor
ζCSM. The
ζCSM value was calculated based on the critical supersaturation model as a function of the two interface temperatures and the total pressure. Frost growth rates under each atmosphere were in proportion to [(
TS1 –
TW1)
t/(1 + 1/
AS1)
0.5. The proportional constant for hydrogen was greater than that for any other tested gas. Agreement and disagreement of the frost effective thermal conductivity with previous models were discussed.
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Sang Phil Han, Jae-Hun Chun, Seung-Man Yang
1995 Volume 28 Issue 6 Pages
738-744
Published: 1995
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An analytical separation of submicron colloidal polystyrene latex particles of different sizes has been carried out by capillary hydrodynamic fractionation. We examined various factors which affect separation of the colloidal particles such as the ratio of particle to tube diameter, the average eluant velocity, like ionic strength, and the surfactant concentration. In particular, the electrokinetic interaction between the capillary wall and the particle was studied intensively by measuring the
ζ-potentials of the capillary wall and the colloidal particles using capillary electrophoresis. The results showed that the increase in the eluant ionic strength, especially of positive ions, reduced the velocity enhancement factor by the screening effect of positive ions. In addition, we confirmed that sodium dodecyl sulphate molecules, which dissociate in aqueous medium into positive sodium ions and hydrocarbon chains with negative charges, modify the electrokinetic properties of the particles in different way from the case for the capillary wall. For the particles, adsorption of the hydrocarbon chains with negative charges changes the
ζ-potential. On the other hand, the screening effect by the dissociated sodium ions is dominant on the electrokinetic properties of the capillary wall.
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Katsuyoshi Kamakura, Hiroyuki Ozoe
1995 Volume 28 Issue 6 Pages
745-749
Published: 1995
Released on J-STAGE: March 26, 2005
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When a two-layer system which consists of a solvent (upper layer) and a solution (lower layer) is heated from a vertical side wall and cooled from the opposing side wall, convection starts in each layer. A Galerkin finite-element method was employed for the numerical analyses of this two-layer convection. Computations were carried out for the Prandtl number
Pr = 6, the aspect ratio
A = 4, the Rayleigh number
Ra = 10
4, the buoyancy ratio
N = 2 to 10 and the Lewis number
Le = 10 to 100. The concentration in the upper layer increased linearly with time through the transfer of the solute across the interface between the layers. In conclusion, the flux of a solute across the interface was independent of the concentration difference between the layers, but dependent on the diffusion coefficient.
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Servillano Olaño, Jr., Shintaro Nagura, Hitoshi Kos ...
1995 Volume 28 Issue 6 Pages
750-757
Published: 1995
Released on J-STAGE: March 26, 2005
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A mass transfer correlation for distillation using a laboratory size wire-gauze structured packing was developed in terms of dimensionless diffusion flux based on experimental data for an acetone-ethanol system under total reflux conditions. The theoretical basis for mass and heat transfer in distillation that was previously developed for wetted-wall columns is shown to apply to structured packings as well. It is also demonstrated that the Sherwood number for distillation exhibited wide scattering due to the effect of convective flux, which is highly influenced by external heat effects and differences in the latent heat of vaporization of the transferring components.
The model obtained from the binary system, which is based on the total area of the structured packing and corrected for the effect of condensation of mixed vapors, is shown to apply to a ternary system of acetone-methanol-ethanol. Simulation results using the correlation for a short column compared well with experimental results for longer columns for binary and ternary systems.
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Naoto Ohmura, Kunio Kataoka, Takeshi Mizumoto, Masaaki Nakata, Kouji M ...
1995 Volume 28 Issue 6 Pages
758-764
Published: 1995
Released on J-STAGE: March 26, 2005
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Bifurcation phenomena in a finite-length Taylor-Couette flow system have been observed by an electrochemical technique. The axial wavelength was varied as the characteristic parameter of vortex cell structure by varying the aspect ratio of the annular flow space and controlling the inner cylinder acceleration up to a steady rotation speed. Multi-resolution analysis in wavelets was used not only for noise reduction, but also for extraction of low frequency components from the experimental time-series data. When the dimensionless axial wavelength
λ/
d < 1, the first fundamental frequency
f1/
fr of singly periodic wavy vortex flow was fixed at a unique value independent of the magnitude of
λ/
d. When
λ/
d ≥ 1, on the other hand,
f1 was not fixed uniquely but showed some variation, depending on the magnitude of
λ/
d. In the transition to doubly periodic wavy vortex flow, not only Hopf bifurcation but also two-cycle period doubling bifurcation occurred in some cases when
λ/
d < 1. The first and second fundamental frequencies,
f1 and
f2 have tendencies to increase with increasing
λ/
d in spite of some exceptions. In the process of a transition to weakly turbulent wavy vortex flow, two-torus motion in phase space broke up at all wavelengths without frequency locking.
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Eduardo González , Juan Ortega
1995 Volume 28 Issue 6 Pages
765-771
Published: 1995
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Isobraric
p-
T-
x-
y values for four binary mixtures composed of several butyl esters (from methanoate to butanoate) with
n-propanol at 101.32 kPa have been measured using a dynamic method. All mixtures presented positi ve deviations from ideality and they were found to be thermodynamically consistent with the point-to-point test, being then correlated with suitable equations. An azeotrope at
x1 = 0.300 and
T = 363.7 K was found for the mixture (
x1, butyl methanoate +
x2 n-propanol). The group contribution models gave acceptable estimations for the
γi values.
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Masahiro Kino-oka, Masahito Taya, Setsuji Tone
1995 Volume 28 Issue 6 Pages
772-778
Published: 1995
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A kinetic model was proposed to represent the profile of pigment production associated with the growth of red beet hairy roots. This model was constructed on the basis of a concept of cellular age distribution arising from a linear growth mode of the roots. The kinetics of root proliferation were formulated using a Monod-type rate equation of root elongation with intracellular phosphorus as a limiting substrate. A positional dependence of pigment content was observed along with the hairy roots; namely, content increased with increasing distance from the root tips and gradually approached a saturated value correlated with intracellular phosphorus content. The kinetics of pigment formation of hairy roots were presented by considering the variation in pigment content along the roots and the intracellular phosphorus effect. It was demonstrated that the model made it possible to describe the kinetic behaviors of growth and pigmentation during hairy root culture in a fermentor.
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Akio Shimono, Seiichiro Koda
1995 Volume 28 Issue 6 Pages
779-785
Published: 1995
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The transport of trace gaseous species from the bulk atmosphere across aqueous surfaces was studied in order to determine the relevant uptake coefficients. A direct observation of the distribution of the trace species in the gas phase above the surface between the gas and aqueous phase was conducted in an impinging How field using a laser-spectroscopic detection technique. By analyzing the experimental results and comparing them to simulation results, the applicability of the present method to obtaining the uptake coefficients was demonstrated in the case of SO
2.
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Yongfu He, Koji Takahashi, Toshio Nomura
1995 Volume 28 Issue 6 Pages
786-789
Published: 1995
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The rate and position of particle-impeller impact for a six-bladed 45°-pitched turbine in the vessels of different scales were measured by the crayon method developed by the authors previously. The impact rate of the pitched turbine pumping upward is higher than that of the pitched turbine pumping downward, but both of them are about 1/6 and 1/17 time, respectively, that of a Rushton turbine. A mathematical model was developed to explain the high dependency of impact rate on impeller speed and impeller diameter. The impact mostly occurs in the outer and upper corners of the blades for the pitched turbine pumping downward, which is consistent with that of the abrasion point of blades of marine impellers used in the chemical industry.
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Atsushi Toyoda, Tatsuo Kanki
1995 Volume 28 Issue 6 Pages
790-796
Published: 1995
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The substrate consumption and microbial growth processes in a PUF (polyurethane foam particles) fluidized bed bioreactor, were formulated by introducing microbial transport between support particle and water phase and the biological predator-prey symbiosis. In formulation, assumptions used were 1) two types of bacteria—motile and flock-forming bacteria—should inhabit simultaneously, 2) two species of protozoa—free-swimming and stalked protozoa—should coexist, 3) bacteria should grow subject to the Mound equation, but flocculation and deflocculation are influenced by protozoa mass concentrations, 4) free-swimming and stalked protozoa should grow preying on motile bacteria subject to the Monod equation, but the rates are subordinatively influenced by substrate concentration. In consequence, the processes were shown to be expressed by a substrate mass balance and eight microbial mass balance equations. The numerical results to these equations were shown to explain well the actual valuations with time passage in TOC and retained and suspended microbial concentrations.
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Ryoichi Kuboi, Tetsuhiro Hasegawa, Koji Yano, Isao Komasawa
1995 Volume 28 Issue 6 Pages
797-802
Published: 1995
Released on J-STAGE: March 26, 2005
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A simple and effective purification process for heat shock proteins (HSPs), in which PEG fractional precipitation was combined with an aqueous two-phase system (ATPS), was successfully developed based upon the proteins’ molecular surface properties. Both GroEL and GroES, typical HSPs from
E. coli, were selectively partitioned to the PEG (top) phase of the ATPS. GroEL and GroES were selectively and stepwisely concentrated from the above PEG phase by PEG fractional precipitation. In addition, the purification of GroEL and GroES as a complex by using biospecific affinity with adenosine triphosphate (ATP) was achieved. GroEL and GroES can be purified either as individual native molecules or as a 1:1 complexed state by the control of ATP addition.
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Koichiro Shiomori, Yoshinobu Kawano, Ryoichi Kuboi, Isao Komasawa
1995 Volume 28 Issue 6 Pages
803-809
Published: 1995
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Hydrophilic bulky proteins with molecular weights larger than 60 kDa, such as catalase,
β-galactosidase, BSA and hemoglobin, can be easily solubilized into a micro water pool of AOT reverse micelles by the injection method. Those proteins and enzymes solubilized into reverse micelles maintain their activities and native structures, and can be back-extracted effectively to a new aqueous phase when the system
pH is kept higher than their isoelectric points,
pI, with low salt concentration, i.e. high water content. The back-extraction of hemoglobin is also partially achieved under these conditions. The efficiency of back-extraction is strongly influenced by the
pH values in the feed protein solution and in the aqueous solution used for back-extraction, as well as KCl concentration in the solution. The
pH values of both solutions should be higher than the protein
pI together with high
Wo or low salt concentration to preserve native structures and activities, since monomers and oligomers with relatively large molecular weight are likely to be denatured by association with ionic surfactant mediated by salt. In this case, both steric and electrostatic interactions between bulky proteins and micelles play dominant roles in the separation. By reducing interactions with micelles or surfactants, proteins solubitized in micelles can be effectively stabilized, and easily back-extracted to the aqueous phase without inactivation. The present method suggests an another way for the effective bioseparation of bulky proteins with high yields of activity.
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Takao Tsukada, Yukihiro Yamamoto, Masahide Sato, Mitsunori Hozawa
1995 Volume 28 Issue 6 Pages
810-815
Published: 1995
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Experiments using a drop tower were carried out to investigate the effects of dc and ac electric fields on the behavior of a bubble in a dielectric liquid under a microgravity environment As a result, the motion of the bubble was strongly affected by electro-hydrodynamic (EHD) convection in the liquid induced by the dc electric field. Bubble motion under the ac electric field was primarily exerted by the dielectrophoretic force acting on the bubble itself. These experimental results were also explained by numerical simulation.
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Masao Sudoh, Yasuyuki Uda, Hayato Komatsubara, Masayuki Katsumata
1995 Volume 28 Issue 6 Pages
816-822
Published: 1995
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The amperometric determination of glucose concentration is classified into two types, oxygen and hydrogen peroxide detector types. The differences in output response of these two detectors are ascribed to the difference of the electrode reaction. Oxygen is reduced to water on the oxygen electrode, while hydrogen peroxide is oxidized to proton and oxygen on the hydrogen peroxide electrode. Since those reaction products, proton and oxygen, relate with the GOD reaction, the sensor current of the hydrogen peroxide detector is considered to be affected by the electrode reaction itself. Theoretical analysis for a rotating-disk electrode covered with an immobilized-enzyme membrane could simulate well experimental outputs of oxygen and hydrogen peroxide electrodes. The output current of the oxygen detector showed asymptotical saturation as glucose concentration increased for the Thiele modulus,
MG, rather than unity. The detection limit of glucose concentration,
CG,lim increased with increasing concentration of the dissolved oxygen,
CO. Oxidation products of hydrogen peroxide affected dominantly with output currents of more than 300 mA·m
–2. The
CG,lim value of the hydrogen peroxide detector was found to be larger than that of the oxygen detector except for the high
CO range at
MG = 1.
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Hajime Tamon, Koji Aburai, Masato Abe, Morio Okazaki
1995 Volume 28 Issue 6 Pages
823-829
Published: 1995
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Adsorption equilibria of eighteen kinds of organic compounds in their aqueous solution were measured on activated carbon and synthetic adsorbents. Affinity coefficients for adsorption were determined by applying the DR equation to measured isotherms. It was found that the affinity coefficient depended on substituent groups of aromatic compounds.
The adsorptive interaction on the activated carbon and the synthetic adsorbents was studied based on the frontier orbital theory. Electronic states of adsorbent, adsorbate and solvent were calculated using the semiempirical molecular orbital method. Then, the characteristic energy of adsorption in aqueous solution was estimated. Affinity coefficients were correlated by the characteristic energy ratio to the energy of the reference adsorbate. It was found that charge transfer interaction played an important role in the adsorption of aromatic compounds in aqueous solution. A correlation procedure of adsorption isotherm was proposed based on the DR equation and the characteristic energy.
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Hideto Matsuyama, Abdul Azis, Mamoru Fujita, Masaaki Teramoto
1995 Volume 28 Issue 6 Pages
830-836
Published: 1995
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Non-equilibrium extraction separation of Pr and Nd was carried out in the presence of diethylenetriaminepentaacetic acid (DTPA) in the aqueous phase. The effects of experimental conditions such as hydrogen ion, DTPA and extractant concentrations on the extraction rates and selectivities were studied. The addition of DTPA was found to be useful to enhance the selectivity. In all cases, the extraction rates of Pr were higher than those of Nd. The extraction rates of Pr and Nd, which are light rare earth metals, were higher than those of the heavy rare earth metals reported previously. This result was attributable to the higher dissociation rates of the DTPA complexes in the aqueous phase for Pr and Nd. The dissociation rate constants of Pr-DTPA and Nd-DTPA complexes were estimated by using the constants available from the literature. The extraction rates and selectivities obtained were satisfactorily analyzed using not fitting parameters, but these estimated values as the dissociation rate constants of the DTPA complexes. This means that it is possible to analyze the extraction rates of the non-equilibrium separation in the presence of DTPA by using the constants available from the literature.
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Fukuji Yamashita
1995 Volume 28 Issue 6 Pages
837-840
Published: 1995
Released on J-STAGE: March 26, 2005
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Axial distribution of gas holdup was measured by static pressure difference and a void sensor in a square bubble column. There were three regions—the entrance region, the bulk region and the foam layer—in the bubble column.
εe, gas holdup in the entrance region, was almost zero and
εb, gas holdup in the bulk region, was axially constant. Gas holdup in the foam layer increased with height above the gas spargers. The clear liquid height and kind of gas sparger had no influence on the form of the axial distribution of static pressure and gas holdup. The thickness of the foam layer and the entrance region was correlated. The effect of the foam layer on the gas holdup was large and was correlated.
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