• KSBB Journal
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• v.11 no.2
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• pp.225-237
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• 1996

Intrinsic binding kinetics of of 125I-bovine serum albumin (125I-BSA) and immobilized monoclonal anti-BSA (MAb 9.1) were studied. Small non-porous polystyrene beads (0.5${\mu}$m diameter) were used as a solid support to minimize the mass transfer interference on rate measurements. We demonstrated both theoretically and experimentally that the binding reaction is kinetically controlled. Rate measurements show that the association reaction is of second order and the dissociation reaction is of first order. Between 4 and $37^{\circ}C$ the measured equilibrium constant agrees well with the equilibrium constant calculated from the rate measurements. The temperature effects on association are much greater than on dissociation; the activation energy for association is about 9Kca1/mole, as compared to 2Kca1/mole for dissociation. The use of small non-porous beads as a solid support in binding studies essentially avoids mass transfer limitations; such a system makes it possible to determine the intrinsic binding characteristics of any immobilized antibody on a solid surface.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.582-587
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• 2022

Biphasic solvents are attracting attention as energy-reducing solvents for capturing CO₂ from flue gas in combustion process. In this study, considering diethylenetriamine (DETA) and diethylethanolamine (DEEA) mixed solvents, one of the biphasic solvents by blending of two types of amines, the CO₂ absorption rates of DETA and DEEA was measured by wetted wall column. The effects of DETA and DEEA concentrations and operating temperature on the overall mass transfer coefficient were investigated. As a result, the overall mass transfer coefficient was proportional to the DETA concentration. However, in the case of the DEEA concentration, the effect was small and when the concentration was exceeded, the overall mass transfer coefficient decreased. The DETA aqueous solution showed little change in the overall mass transfer coefficient with the operating temperature, whereas the DEEA aqueous solution increased the overall mass transfer coefficient with the operating temperature. As a result of obtaining the observed reaction rate constant under the pseudo-first-order reaction assumption, it was found that the observed reaction rate constant in DETA aqueous solution was proportional to the DETA concentration, but DEEA did not fit the pseudo-first-order reaction assumption.

• Journal of Soil and Groundwater Environment
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• v.16 no.6
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• pp.79-94
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• 2011

Black carbon (BC), a kind of high surface area carbonaceous material (HSACM), was isolated from Andong lake sediment. Sorption and desorption kinetics of naphthalene (Naph) and phenanthrene (Phen) in organic carbon (OC) and BC in the Andong lake sediment were investigated. Several kinetic models such as one-site mass transfer model (OSMTM), two-compartment first-order kinetic model (TCFOKM), and a newly proposed modified two-compartment first-order kinetic model (MTCFOKM) were used to describe the sorption and desorption kinetics. The MTCFOKM was the best fitting model. The MTCFOKM for sorption kinetics showed that i) the sorbed amounts of PAHs onto BC were higher than those onto OC, consistent with BET surface area; ii) the equilibration time for sorption onto BC was longer than those onto OC due to smaller size of micropore ($11.67{\AA}$) of BC than OC ($38.18{\AA}$); iii) initial sorption velocity of BC was higher than OC; and iv) the slow sorption velocity in BC caused the later equilibrium time than OC even though the fast sorption velocity was early completed in both BC and OC. The MTCFOKM also described the desorption of PAHs from the OC and BC well. After desorption, the remaining fractions of PAHs in BC were higher than those in OC due to stronger PAHs-BC binding. The remaining fractions increased with aging for both BC and OC.

• Proceedings of the Korean Environmental Health Society Conference
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• 2002.04a
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• pp.9-12
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• 2002

Diffusive transport of volatile organic compounds(VOCs) and their degradation by bacteria in unsaturated soils are couple by poorly understood mass transfer kinetics at the gas/water interface. Determination of the fate of VOCs in unsaturated soil is necessary to evaluate the feasibility of natural attenuation as a VOC remediation strategy. The objective of this study was to develop a mechanistically based mathematical model that would consider the interdependence of VOC transport, microbial activity, and sorptive interaction in a moist, unsaturated soil. Because the focus of the model was on description of natural attenuation, the advective VOC transport that is induced in engineered remediation processes such as vapor extraction was not considered. The utility of the model was assessed through its ability to describe experimental observations form diffusion experiments using toluene as a representative VOC in well-defined soil columns that contained a toluene degrading bacterium, Pseudomonas Putida, as the sole active microbial species. The coefficient for gas-liquid mass-transfer, K$\sub$LA/, was found to be a key parameter controlling the ability of bacteria to degrade VOCs. This finding indicates that soil size and geometry are likely to be important parameters in assessing the possible success of natural attenuation of VOCs in contaminated unsaturated soils.

• Korea-Australia Rheology Journal
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• v.20 no.1
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• pp.1-6
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• 2008

Absorption rate of carbon dioxide was measured in the aqueous xanthan gum (XG) solution in the range of 0-0.15 wt% containing 2-amino-2-methyl-1-propanol (AMP) of $0-2\;kmol/m^3$ in a flat-stirred vessel with an impeller of 0.05m and agitation speed of 50rpm at $25^{\circ}C$ and 0.101 MPa. The volumetric liquid-side mass transfer coefficient ($k_La$) of $CO_2$, which was correlated with the viscosity and the elastic behavior of XG solution containing Deborah number as an empirical formula, was used to estimate the chemical absorption rate of $CO_2\;(R_A)$. $R_A$, which was estimated by mass transfer mechanism based on the film theory using the physicochemical properties and the kinetics of reaction between $CO_2$ and AMP, was compared with the measured rate. The aqueous XG solution with elastic property of non-Newtonian liquid made $R_A$ increased compared with Newtonian liquid based on the same viscosity of the solution.

• Clean Technology
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• v.14 no.4
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• pp.281-286
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• 2008

Absorption rate of carbon dioxide was measured in the aqueous polyacrylamide (PAA) solution containing triethanolamine (TEA) of $0{\sim}2.0\;kg\;mol/m^3$ in a flat-stirred vessel with an impeller of 0.05 m and agitation speed of 50 rpm at $25^{\circ}C$ and 101.3 kPa. The chemical absorption rate of $CO_2$ was estimated by mass transfer mechanism based on the film theory using the physicochemical properties containing the liquid-side mass transfer coefficient of $CO_2$ and the kinetics of reaction between $CO_2$ and TEA to compare with the measured rate. The aqueous PAA solution acted as a reducing agent by viscoelastic property of non-Newtonian liquid based on the same viscosity of the solution.

• Applied Chemistry for Engineering
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• v.4 no.4
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• pp.739-745
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• 1993

The characteristics of mass transfer in an inorganic ion exchange system where Cs and/or Sr are separated by means of zeolites was investigated. Experimental work to separate Cs or Sr was carried out for Cs-AW300 and CS-AW500 systems in case of Cs whereas for Sr-4A and Sr-13X systems in case of Sr. The experimental conditions were chosen as follows in the batch type separation : temperature $25^{\circ}C$, agitation speed 300rpm, amount of zeolite 4g, volume of solution $0.5{\ell}$, and concentrations of solution 1000ppm, 2000ppm, respectively. As a result, it was found that the mass transfer rate is controlled mainly by the liquid film diffusion. The mass transfer coefficients in the film were found to be in the range of $10^{-4}{\sim}10^{-3}cm/sec$, while the apparent diffusivity inside the particles was found to be in the order of $10^{-8}cm^2/sec$.

• Journal of Biomedical Engineering Research
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• v.15 no.1
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• pp.41-50
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• 1994

The chemotherapy using macromolecules, i.e., monoclonal antibodies loaded with anticancer agents hasn't been successful in delivering therapeutic amount of the conjugates. The comprehensive evaluation of mass transfer factors in tumor is prerequisite for the development of the effective chemotherapy. Characterization of neuroblastoma implanted in immunosuppressed athymic nude rats was performed. Its growth kinetics, glucose metabolic rate (GMR) were measured along with the interstitial fluid pressure (IFP), blood perfusion rate (BPR) and pH distribution throughtout the tumor radius. Volume doubling time and GMR were 8.1 days(SD 0.44 day), 23.53 mg/min/100 g(SD 3.54 mg/min/100 g), respectively. The IFP in tumor center was increased with tumor volume, and approached to 3 mmHg (SD 2.6 mmHg) when the tumor was 3 cm high. The radial distribution of IFP, BPR and pH in 2 cm high tumors showed that BPR and pH were decreased, while IFP was increased as the ~ensors moved toward the tumor center. The elevated IFP, decreased BPR and pH in tumor center suggested that the delivery of conjugates might be increased by properly manipulating mass transfer factors.

• Journal of Environmental Science International
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• v.30 no.6
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• pp.429-439
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• 2021

Food waste is both an industrial and residential source of pollution, and there has been a great need for food waste reduction. As a preliminary step in this study, waste reduction is quantitatively modeled. This study presents two models based on kinetics: a simple kinetic model and a mass transport-shrinking model. In the simple kinetic model, the smaller is the reaction rate constant ratio k₁, the lower the rate of conversion from the raw material to intermediate products. Accordingly, the total elapsed reaction time becomes shorter. In the mass transport-shrinking model, the smaller is the microbial decomposition resistance versus the liquid mass transfer resistance, the greater is the reduction rate of the radius of spherical waste particles. Results showed that the computed reduction of waste mass in the second model agreed reasonably with that obtained from a few experimantal trials of biodegradation, in which the microbial effect appeared to dominate. All calculations were performed using MATLAB 2020 on PC.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.297-305
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• 2017

The use of peroxidase in the nitration of phenols is gaining interest as compared with traditional chemical reactions. We investigated the kinetic characteristics of phenol nitration catalyzed by horseradish peroxidase (HRP) in an aqueous-organic biphasic system using n-butanol as the organic solvent and ${NO_2}^-$ and $H_2O_2$ as substrates. The reaction rate was mainly controlled by the reaction kinetics in the aqueous phase when appropriate agitation was used to enhance mass transfer in the biphasic system. The initial velocity of the reaction increased with increasing HRP concentration. Additionally, an increase in the substrate concentrations of phenol (0-2 mM in organic phase) or $H_2O_2$ (0-0.1 mM in aqueous phase) enhanced the nitration efficiency catalyzed by HRP. In contrast, high concentrations of organic solvent decreased the kinetic parameter $V_{max}/K_m$. No inhibition of enzyme activity was observed when the concentrations of phenol and $H_2O_2$ were at or below 10 mM and 0.1 mM, respectively. On the basis of the peroxidase catalytic mechanism, a double-substrate ping-pong kinetic model was established. The kinetic parameters were ${K_m}^{H_2O_2}=1.09mM$, ${K_m}^{PhOH}=9.45mM$, and $V_{max}=0.196mM/min$. The proposed model was well fit to the data obtained from additional independent experiments under the suggested optimal synthesis conditions. The kinetic model developed in this paper lays a foundation for further comprehensive study of enzymatic nitration kinetics.