• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.841-849
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• 2012

The effluent quality of phosphorus is strengthened by the national standard to conserve water resources to lessen the eutrophication threat. The soluble phosphate in the wastewater effluent can be removed using the converter slag as solid waste produced through the steel making process. The experiments for removal efficiencies and removal constants were performed for this research with the artificial wastewater following several different conditions, particle size, phosphate concentration and initial pH. The correlation coefficients of Freundlich adsorption isothem were 0.9505 for $PS_A$, 0.9183 for $PS_B$, respectively. The removal efficiency was 87-94 % for $PS_A$ and 90-96 % for $PS_B$ respectively. The pH of the wastewater was elevated to pH 11.8 for the initial pH 8.5, phosphate removal efficiency was the highest as 84 % ~ 98 %. In case of 10 mg/L of the intial phosphate, the removal efficiency was 96 ~ 98 %. The more initial pH increases, the higher the reaction rate constant is.

• BMB Reports
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• v.28 no.1
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• pp.40-45
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• 1995

Acetolactate synthase purified from Serratia marcescens ATCC 25419 was rapidly inactivated by the thiol specific reagent p-chloromercuribenzoate (PCMB), the tryptophan specific reagent N-bromosuccinimide (NBS), and the arginine modifying reagent phenylglyoxal (PGO). Inactivation by PCMB was prevented by both ${\alpha}$-ketobutyrate and pyruvate, and the second order rate constant for the inactivation was $2480\;M^{-1}{\cdot}min^{-1}$. The reaction order with respect to PCMB was 0.94. The inactivation of the enzyme by NBS was also substantially reduced by both ${\alpha}$-ketobutyrate and pyruvate. The second order rate constant for inactivation by NBS was $15,000\;M^{-1}{\cdot}min^{-1}$, and the reaction order was 2.0. On the other hand, inactivation by PGO was partially prevented by ${\alpha}$-ketobutyrate, but not by pyruvate. The second order rate constant for the inactivation was $1480\;M^{-1}{\cdot}min^{-1}$ and the order of reaction with respect to PGO was 0.75. These results suggest that essential cysteine, tryptophan and arginine are located at or near the substrate binding site.

• Korean Journal of Veterinary Service
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• v.39 no.2
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• pp.93-99
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• 2016

The anesthetic depth and cardiovascular effect of alfaxalone constant rate infusion in dogs premedicated with xylazine or acepromazine were evaluated. Ten dogs were randomly allocated into 2 groups. In group AA, dogs were premedicated with 0.02 mg/kg of intravenous acepromazine at 15 min before induction. In group XA 1.1 mg/kg of intravenous xylazine was premedicated at 5 min before induction. The anesthesia was maintained with 6 mg/kg/hr of alfaxalone after induction with 2 mg/kg alfaxalone in both groups. In both of groups, the qualities of induction were satisfactory without any adverse event, but adequate analgesia could not be provided, according to the withdrawal test. $PaO_2$ and $SaO_2$ implied a slight hypoxemia state in XA group, while those values of group AA were not significantly changed. The acepromazine and alfaxalone combination induce mild tachycardia. The bispectral index score were significantly decreased in group XA, compared with that in group AA. The premedication of xylazine before alfaxalone constant rate infusion in this study could provide adequate analgesia during 30 min, while the premedication with acepromazine could not.

• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.139-145
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• 2005

Artificial neural networks (ANNs), for a first time, were successfully developed for the modeling and prediction of solvent effects on rate constant of [2+2] cycloaddition reaction of diethyl azodicarboxylate with ethyl vinyl ether in various solvents with diverse chemical structures using quantitative structure-activity relationship. The most positive charge of hydrogen atom (q$^+$), dipole moment ($\mu$), the Hildebrand solubility parameter (${\delta}_H^2$) and total charges in molecule (q$_t$) are inputs and output of ANN is log k$_2$ . For evaluation of the predictive power of the generated ANN, the optimized network with 68 various solvents as training set was used to predict log k$_2$ of the reaction in 16 solvents in the prediction set. The results obtained using ANN was compared with the experimental values as well as with those obtained using multi-parameter linear regression (MLR) model and showed superiority of the ANN model over the regression model. Mean square error (MSE) of 0.0806 for the prediction set by MLR model should be compared with the value of 0.0275 for ANN model. These improvements are due to the fact that the reaction rate constant shows non-linear correlations with the descriptors.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.217-229
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• 2000

Adsorption equilibrium experiments for the phenol on granular activated carbon(16~25 mesh) and powder activated carbon(325 mesh) were carried out at $25{\pm}1^{\circ}C$ and the results were expressed with Freundlich isotherm. Adsorption rate experiments were executed in batch adsorption system under the condition that can be neglecting mass transfer resistance at the external surface of the particle. The results were analysed with the Miller's method to evaluate the linear driving force(LDF) adsorption rate constant. Fixed bed adsorption experiments were performed by adopting different flow rates in the activated carbon-phenol system at $25{\pm}1^{\circ}C$. The theoretical breakthrough curves were estimated with the simple constant pattern solution. The adsorption rate constant of LDF model was not a fixed value but variable with adsorption amount. The experimental results were better agreed with the estimation of breakthrough curve using the variable adsorption rate constant than the results estimated using the average fixed adsorption rate constant.

• Journal of Electrical Engineering and Technology
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• v.1 no.1
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• pp.110-113
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• 2006

A high rate deposition sputtering process of magnesium oxide thin film in oxide mode has been developed using a 20 kW unipolar pulsed power supply. The power supply was operated at a maximum constant voltage of 500 V and a constant current of 40 A. The pulse repetition rate and the duty were changed in the ranges of $10\sim50$ kHz and $10\sim60%$, respectively. The deposition rate increased with rising incident power to the target. Maximum incident power to the magnesium target was obtained by the control of frequency, duty and current. The deposition rate of a moving state was 9 nm m/min at the average power of 1.5 kW. This result shows higher deposition rate than any other previous work involving reactive sputtering in oxide mode. The thickness uniformities over the entire substrate area of $982mm{\times}563mm$ were observed at the processing pressure of $2.8\sim9.5$ mTorr. The thickness distribution was improved at lower pressure. This technique is proposed for application to a high through-put sputtering system for plasma display panels.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.380-385
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• 2009

The absorption rate of carbon dioxide with 2-amino-2-methyl-1-propanol(AMP) was measured in such non-aqueous solvents as methanol, ethanol, n-propanol, n-butanol, ethylene glycol, propylene glycol, and propylene carbonate, and in water at 298 K and 101.3 kPa using a semi-batch stirred tank with a plane gas-liquid interface. The overall reaction rate constant, obtained under the condition of fast reaction regime, from the measured rate of absorption was used to get the elementary reaction rate constants in complicated reactions represented by reaction mechanism of carbamate formation and the order of overall reaction of $CO_2$ with amine. The correlation between the elementary reaction rate constant and the solubility parameter of the solvent was also presented.

• Journal of Pharmaceutical Investigation
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• v.5 no.2
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• pp.51-56
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• 1975

In the course of the investigations on drug metabolism and drug disposition in man, it has been noted that there are often rather striking individual differences in the response to drugs and in the ability to metabolize and dispose of drugs. Some of the person-to-person differences are due to environmental factors, but some have clearly demonstrated to be genetically determined. This report determined the rate of acetylation and some constants of sulfa-methizole to korean. The results are as follows: The overall removal rate of drug from the body is 0.572(k, $hr^{-1}$) the rate constant for acetylation, 0.222($k_2$, $hr^{-1}$) the rate constant for excretion of unchanged drug, 0.350($k_3$, $hr^{-1}$) and the faction of a dose ultimately excreted in the urine as unchanged drug is 0.677. And this report determined the optimal time to make a single blood level determination after an oral dose of the drug and obtain a reasonable index of the rate of sulfamethizole metabolism. The resulting data(sulfamethizole levels at 5 hours after drug administration) clearly established bimodality even though only about 106 subjects were tested.

• Journal of Biosystems Engineering
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• v.11 no.1
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• pp.52-63
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• 1986

This study was performed to find out drying characteristics and develop drying model for the design of an efficient dryer or drying system of red peper. The basic model which describes drying phenomenon of red pepper was firstly established, and drying tests were conducted at 14-different drying conditions. In this test, the effects of drying air temperature and relative humidity on the rate of drying were undertaken. Finally, a new drying model based on these experimental results was developed to describe the drying characteristics of red pepper. The results from this study may be summarized as follows. 1. Drying constant of the basic model established from Lewis' experimental model and diffusion equation was theoretically deduced as a function of moisture content and inner-temperature of red pepper. 2. From the results of drying tests, drying air temperature was found to have the greatest effect on the rate of drying. However, the effect of temperature was small for the condition of high relative humidity, and for low temperature, the effect of relative humidity was found to be large even though the range of relative humidity was low. 3. Modified Henderson equation was found to be better than Chung equation as the EMC model for the estimation of the equilibrium moisture content of red Pepper. 4. Constant-rate drying period did not exist in the red pepper drying test. And falling-rate drying period was divided into three distinct phases. Drying rate was dependent on the moisture content, the inner-temperature of red pepper and the change of physical property due to drying. 5. Drying constant increased with decrease of free moisture content, but it decreased at the end of the drying period. Also, drying constant was dependent on the drying air temperature and relative humidity. 6. The new drying model developed in this study was found to be most suitable in describing the drying characteristics of red pepper. Therefore, it may be concluded that drying time could be accurately estimated by the new drying model.

• Membrane and Water Treatment
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• v.5 no.4
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• pp.281-293
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• 2014

The present work aimed to study the decolorization kinetics and characteristics of a selected azo dye under the influence of two key operational parameters including hydraulic retention time (HRT) and solid retention time (SRT). The decolorization efficiency and the two important criteria of k and normalized k (k/MLSS) were evaluated in lab-scale membrane sequencing batch reactors (MSBRs) at various HRTs of 48, 24 and 16 h (with constant SRT) and in addition, at various SRTs of infinity, 40 and 10 d (with constant HRT). According to the obtained results, both zero and first-order kinetics were properly fitted the decolorization profiles of the selected azo dye in all of the applied HRTs and SRTs. Increase of both HRT and SRT positively affected the decolorization efficiency. More MLSS concentrations corresponded to the lower HRTs and the higher SRTs resulted in higher decolorization rate constants (k). However, the effect of reducing the HRT was not compensated by increase of the MLSS concentration in order to reach higher decolorization efficiency. In addition, increase of the decolorization efficiency, as a consequence of the higher MLSS concentrations at longer SRTs, was restrained by decrease of the time-limited decolorization capability of biomass (represented by normalized k). Evaluation of both k and normalized k is suggested in order to have a more precise study on the decolorization kinetics and characteristics.