• Journal of the East Asian Society of Dietary Life
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• v.19 no.1
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• pp.32-37
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• 2009

This study was carried out to gather basic data on the restoration and extent of Don tea (a coin-shaped tea), the traditional tea of Korea. We examined the physicochemical components and anti-microbial activity of Don tea extracts at 0, 5 and 10 months. The Hunter value $L^*$, of Don tea extracts which were matured for 10 months decreased from 7.01 to 4.97 compared to that when the extracts were first manufactured. However, the $b^*$ value increased from 0.09 to 2.67. There were higher contents of inorganic matter in Don tea extracts following manufacture in the order of K (14.12 mg/100 mL), Mg (0.94 mg/100 mL), P (0.88 mg/100 mL), Ca (0.16 mg/100 mL) and Mn (0.16 mg/100 mL). Classified catechins contents were found in the order of C (19.97 mg/100 mL), EGC (9.30 mg/100 mL), ECG (9.02 mg/100 mL), GCG (8.50 mg/100 mL), GC (7.61 mg/100 mL) and CG (5.63 mg/100 mL). The longer the maturation period of the Don tea extracts, the lower the contents of inorganic matter and catechins. However, this did not apply to the total phenol contents, particularly in the phenol contents of Don tea extracts matured for 10 months which increased by 93.82 mg/l00 mL. Don tea extracts which were matured for longer periods showed higher anti-microbial activities against Bacillus subtilis and Streptococcus mutans. However, there were lower activities against Staphylococcus aureus, Escherichia coli and Salmonella enteritidis. Consequently, it was concluded that a shorter maturation period was required for the effective utilization of the inorganic matter, the catechins and the gram-negative bacteria in the Don tea extracts. However, a longer maturation period of 10 months was found to effectively utilize the total phenol compound contents and the gram-positive bacteria.

• Journal of the Korean GEO-environmental Society
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• v.1 no.1
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• pp.79-85
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• 2000

The environmental assessment on the open dumping landfill of small scale which was situated in local small city was carried out to reuse the landfill site as the residental, commercial and other purposes through the analysis of the leachate of landfill, extracted solution from landfill waste. The waste was landfilled at 5.5~8m depth and the covered layer so poor as 20~50cm thickness. The biodegradable organic matters were almost degraded and the result of the leachate of landfill showed that the BOD/COD ratio were measured as 0.079, pH 7.2~7.6, SS 47736mg/L, COD 6193.8mg/L, T-N 596mg/L, and T-P 123.9mg/L respectively. These results were higher than those of extracted solution of landfill waste as the COD and BOD were measured as low values and T-N 7.77mg/L and T-P as 0.20mg/L lower concentrations the landfill appears the maturation phase. As the result of the assessment on the open dumping landfill of small scale, if appears that this landfill is maturation phase and the formation leachate is reduced. If the treatment facility of leachate from landfill and the layer which protects the inflow/infiltration is prepared, it can be safely used as this landfill site.

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.471-478
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• 2000

The pharmacokinetic properties of KR-V compounds, recently developed as new anti-HIV agents, were studied after i.v. and p.o. administration in rats. The concentrations of the KR-V series were determined in rat plasma using an high-performance liquid chromatography (HPLC)-UV detection system. Of the 19 KR-V compounds investigated in the present study, only KR-V 3, 10, 14, 16 and 18-1 showed oral bioavailability. The plasma concentration-time data could be adequately described by an one-compartment open model. In the i.v. kinetic study (10mg/kg), the CLt of KR-V 3, 10, 14 and 16 (>4L/hr/kg) were significantly higher than that of KR-V 18-1 (1.1 L/hr/kg). The AUC of KR-V 18-1 was greater ($8.97{\mu}g{\cdot}hr/ml$) than that of the other compounds, but the Vd (0.58 L/kg) was lower. In the p.o. kinetic study (50mg/kg), although the t-1/2 of KR-V 18-1 was shorter than that of the other compounds, the AUC ($3.659{\mu}g{\cdot}hr/ml)$ and $C_{max}(1.891{\mu}g/ml$) were markedly higher. In a seperated in vitro experiment, only KR-V 18-1, of the 5 compounds with bioavailibility, exhibits potent activity against HIV-1 mutant strains. Therefore, KR-V 18-1 is expected to become a new potent anti-AIDS drug candidate/lead compound.

• Analytical Science and Technology
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• v.19 no.3
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• pp.239-243
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• 2006

This method is used for the determination of itraconazole in human plasma by liquid-liquid extraction and high performance liquid chromatography. Felodipine was used as an internal standard. After extraction of the plasma with diethyl ether, the centrifuged upper layer was then transferred. The supernantant was evaporated and then reconsituted with mobile phase. The mobile phase was composed of 10 mM ammonium acetate adjusted to pH 7 by phosphoric acid with a flow rate of 0.2 mL/min. A C18 reversed-phase column with a pre-column was used as the analytial column. Linear detection responses were obtained for itraconzole concentration range for 2~1,000 ng/mL. The correlation coefficient of linear regression($R^2$) was 0.9991, limit of quantification (LOQ) was 2 ng/mL, reproducibility was less than 10.8 %, and accuracy was 97.2~108.2%. This method has been successfully applied to the pharmacokinetic study of itraconazole in human plasma.

• Fisheries and Aquatic Sciences
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• v.5 no.2
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• pp.97-102
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• 2002

Pyricularia oryzae (P. oryzae), the cause of rice blast, is one of the most important fungal pathogens of rice. Seventy strains of marine fungi were isolated from marine algae, and it was measured antifungal activity against P. oryzae. Metabolites of marine fungus A-248 which isolated from marine algae showed strong antifungal activity against P. oryzae. The antifungal substance from the metabolites of marine fungus A-248 was extracted with ethylacetate, and then purified by preparative TLC and reverse-phase HPLC. The minimum inhibitory concentration (MIC) value was $0.18\mu g/mL$ for the antifungal activity of the substance purified from A-248 metabolites. The purified substance was similar to antifungal activity of rhizoxin, which is a commercial antifungal agent.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1997.05a
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• pp.97-100
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• 1997

본 연구에서는 알루미늄 제작 공정에서 폐기물로 발생하는 gibbsite를 이용하여 용액 내에 존재하는 인산염을 제거하였다. 실험을 수행함에 있어 용액의 pH를 3, 7, 10으로 변화시켜 보았고 인산염 제거에 미치는 여러 인자들 중에서 P : Al 의 비율이 미치는 영향을 살펴보고자 인산염의 농도를 100, 200, 500, 800, 1000 mg/l 로 변화시켰으며, gibbsite 의 양을 2, 4, 8, 10 g 으로 변화시켜 실험하였다. 이러한 실험 결과로부터 72 hr 이후에 용액 내의 인산염 농도가 일정하게 유지된다는 것을 알 수 있있다. 인산염의 제거율은 pH가 낮을수록 높아졌다. 또한 인산염의 초기농도가 낮을수록 제거율이 높아졌으며, 투여된 gibbsite 의 양이 많을수록 제거율이 높아지는 것으로 나타났다.

• Journal of Aquaculture
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• v.19 no.1
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• pp.7-13
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• 2006

In this study, environmental parameters of natural habitat were measured to find out suitable place for release and improve the productivity of Protothaca jedoensis in Gamak Bay. Water temperature, salinity of the habitat ranged from 5.4 to 27.6 and from 26.5 to $34.5\%_{\circ}$, respectively. Range of pH, DO, COD, Chl-a, T-N and T-P were $7.82{\sim}8.39,\;5.31{\sim}11.28mg/L,\;0.13{\sim}1.38mg/L,\;3.05{\sim}11.55mg/L,\;0.005{\sim}0.180mg/L\;and\;0.007{\sim}0.028mg/L$ respectively. Dominant grain size was fine silt and the IL of sediment was ranged from $0.75{\sim}7.26%$. The water content was $20.16{\sim}53.65%$ and highest value was observed in Baegyado. The COD and AVS in the sediments ranged from $0.53{\sim}8.67mg/g-dry$ and $0.002{\sim}0.113mg/g-dry$ respectively. The bottom condition of Baegyado was higher than other area.

• Journal of Environmental Science International
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• v.21 no.4
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• pp.479-488
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• 2012

A Dielectric barrier discharge (DBD) plasma is shown in the present investigation to be effective of phenol degradation in the aqueous solutions in batch reactor with continuous air bubbling. Removal of phenol and effects of various parameters on the removal efficiency in the aqueous solution with high-voltage streamer discharge plasma are studied. The effect of 1st voltage (80 ~ 220 V), air flow rate (3 ~ 7 L/min), pH (3 ~ 11), electric conductivity of solution (4.16 ${\mu}S$/cm, deionized water) ~ 16.57 mS/cm (addition of NaCl 10 g/L) and initial phenol concentration (2.5 ~ 20.0 mg/L) were investigated. The observed results showed that phenol degradation was higher in the basic solution than that of the acidic. The optimum values on the 1st voltage and air flow rate for phenol degradation were 140 V and 6 L/min, respectively. It was considered that absorbance variation of $UV_{254}$ of phenol solution can be use as an indirect indicator of change of the non-biodegradable organic compounds within the treated phenol solution. Electric conductivity was not influenced the phenol degradation. To obtain the removal efficiency of phenol and COD of phenol over 97 % (initial phenol concentration, 10.0 mg/L), 80 min and 120 min were need, respectively. Phenol and COD degradation showed a pseudo-first order kinetics.

• Journal of the Korean GEO-environmental Society
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• v.14 no.5
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• pp.57-63
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• 2013

In this study, the characteristics of degradation and mineralization of diazinon using a statistical approach based on Box-Behnken design (BBD, one of response surface method) was investigated in an E-beam process, and also the main factors with diazinon concentration ($X_1$), irradiatin intensity ($X_2$) and pH ($X_3$) which consisted of 3 levels in each factor was set up to determine the effects of factors and optimization. At first, effects of pH and diazinon concentration were investigated to determine the proper range of application on response surface method(RSM). In statistical approach, the regression analysis and analysis of variance (ANOVA) were applied to evaluate the quantitative comparison of each factors in order to obtain the effects were irradiation intensity>diazinon concentration>pH. The regression model predicted the optimization point using the response optimizer to consider the effects of operation conditions were $Y_1=81.73-5.58X_1+23.69X_2-14.23X{_2}^2+4.22X{_3}^2(R^2=99.7%)$, $Y_2=35.23-3.01X_1+10.79X_2-7.58X_2{^2}(R^2=97.9%)$ and 95.7% of diazinon degradation, 41.8% of TOC reduction at 12.75mg/L and 4.26kGy, respectively. The pH condition was not significantly affects on E-beam process than other advanced oxidation processes (AOPs).

• Journal of Environmental Science International
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• v.30 no.1
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• pp.69-76
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• 2021

The purposes of this study were to evaluate the removal characteristics of COD, Ni, and P and to derive appropriate operating conditions for the plating wastewater according to NaOCl reaction time and pH operating conditions in the BPC unit process during the plating wastewater treatment process. As a results of evaluating the removal characteristics for raw wastewater by each BPC unit process, the removal efficiencies of COD, Ni and P in BPC 1-1 unit process were 72.8%, 99.1%, and 100.0%. Therefore, the proper reaction time of NaOCl was derived as 21.1 minutes. In order to maintain the +800 mV ORP and the reaction time of 20 minutes, the temporary injection and continuous injection of NaOCl in the BPC unit process were 13.7 mL and 18.7 mL, respectively. It was found that the temporary injection method of NaOCl reduced the chemical cost by 36.5% compared to the continuous injection method. Also, Ni showed the highest removal efficiency of 97.8% at pH 10.5. On the other hand, P showed a removal efficiency of 57.4% at pH 10.0.