• Microbiology and Biotechnology Letters
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• v.37 no.1
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• pp.42-48
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• 2009

Anticandidial activity of seven herbal extracts, Taraxacum Platycarpum, Houttuyniae Herba, Lonicerae Flos, Anemarrhena Rhizome, Forsythia Fruit, Paeoniae Ratix, and Coptidis Rhizoma, were determined against five different Candida sp. by agar diffusion assay. The concentration of total phenolic compounds of seven herbal extracts ranged from 0.6 to $2.5{\mu}g/mg$. The total antioxidant activities showed that Taraxacum Platycarpum and Houttuyniae Herba were 60% in 80% ethanol extract and Lonicera Flower and Paeoniae Ratix were 70, 75%, respectively, in 100% ethanol extract. Coptidis Rhizoma extract showed antifungal activity against non-Candida albicans, C. tropicalis and C. glabrata. The MIC values of a compound separated in TLC from Coptidis Rhizoma extract were 24, and $48{\mu}g/mL$ against C. tropicalis and C. glabrata. The above compound showed the same retention time with berberin in HPLC analysis.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.783-792
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• 2007

To investigate the effects of alkalinity on the nitrification capability of the nonwoven fabric filter bioreactor(NFBR), an experiment was performed for 641 days at a hydraulic retention time of approximately 11 hours by changing the influent concentration of $NH_3-N$ from 54 mg/L to 1,400 mg/L and alkalinity from 43 mg/L to 10,480 mg/L. The MLSS concentration reduced from an initial value of 2,650 mg/L down to 830 mg/L, then increased up to 8,340 mg/L. Though the volumetric loading rate varied in a range of $0.120\sim3.130$ kg $NH_3-N/m^3-day$, the F/M ratio showed a narrow range of $0.067\sim0.414$ kg $NH_3-N/kg$ MLSS-day. The average nitrification efficiency at each experimental stage resulted in the range of $35.2\sim100%$, and the maximum nitrification rate was 2.970 kg $N/m^3-day$ or 0.489 g N/g MLVSS-day. The nitrifiers' fraction of the MLVSS increased up to 100% from an initial value of 7.1% and the biofilm formed on the nonwoven fabric filter showed a very low nitrifiers' fraction of mere 2.2%. The growth yield of the MLSS and the alkalinity consumption rate were computed to be 0.117 g VSS/g N removed and 7.08 g alkalinity/g $NO_x^--N$ produced, respectively. Results of the research suggest that NFBR could be an adequate process for nitrification of wastewaters with high ammonia concentrations.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.839-845
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• 2007

Temperature dependence of kinetic constants in the anaerobic acidogenesis was investigated using anaerobic chemostat-type reactor. Glucose was used as a substrate in this experiment. Temperature ranging from 15 to $30^{\circ}C$ were studied. The saturation constant$(k_s\upsilon)$ and growth yield(Y) decreased with increasing temperature, while the maximum specific substrate utilization rate$(\upsilon_{max})$ increased. A temperature correction factor$(Q_{10})$ values of the substrate utilization rate and bacteria growth rate were the range from 1.3 to 2.2 and 1.5 to 2.2, respectively. The growth yield(Y) for the acidogenesis process was less sensitive to temperature changes than the maximum specific substrate utilization rate$(\upsilon_{max})$. The simulation model of the relationship between the substrate and sludge retention time(SRT) at the temperature range of 20 to $30^{\circ}C$ is obtained as the following ; $1/SRT={(6.53){\cdot}(1.038)^{T-20}{\cdot}(S/X)}/{(1.38){\cdot}(0.983)^{T-20}+(S/X)}$.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.5
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• pp.491-499
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• 2008

It is really urgent to develop wastewater treatment system which is economically efficient, occupies small area for buildup, can be easily operated, discharges small amount of sludge due to the more strict water quality standard, the expensive water and energy cost and so on. This study on treatment of wastewater including nonbiodegadable materials using white-rot fungus biofilm were designed to investigate the submerged type of biofilm, hydraulic retention times, recycle rates, and module turning times. Removal efficiencies of fully exposed biofilm type in atmosphere are similar to submerged biofilm of aeration type. The optimum conditions of white-rot fungus biofilm of fully exposed type in atmosphere are HRT 3$\sim$4 hr, recycle rate 6$\sim$10 Q, module turning times 0.5$\sim$2 times/min. At this time, removal efficiencies of organics were COD$_{Cr}$ 65.0$\sim$69.9%, NBDCOD 70.4$\sim$72.7%, BOD$_5$ 88.8$\sim$90.1%, SS 84.2$\sim$90.4%. Moreover average effluent concentration of BOD$_5$(8.9 mg/L) satisfied water quality standard of heavy water(BOD$_5$ less than 10 mg/L) but concentration of NBDCOD(29.6 mg/L) was higher than water quality standard of heavy water(NBDCOD less than 20 mg/L).

• The Korean Journal of Pain
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• v.19 no.1
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• pp.91-95
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• 2006

Background: Opioid delivered by epidural patient-controlled analgesia (PCA) is effective in relieving pain after surgery, but it is associated with side effects, such as nausea, vomiting, pruritus, respiratory depression, and urinary retention. The purpose of this study was to compare hydromorphone related side effects and the quality of analgesia when naloxone was added to epidural PCA regimen. Methods: Fifty-two thoracotomy patients with PCA were allocated blindly into two groups. Patients in group H (n = 26) received continuous epidural hydromorphone ($16{\mu}g/ml$) in 0.1% bupivacaine; patients in group N (n = 26) received an epidural infusion containing naloxone ($2{\mu}g/ml$) and hydromorphone ($16{\mu}g/ml$) in 0.1% bupivacaine. The basal rate of PCA was 4 ml/hr and the demand dose was 1.5 ml with a lockout time of 15 min. Pain intensity, sedation, pruritus, nausea and vomiting, respiratory depression were checked at 6, 12, 24 hours postoperatively. Results: The Visual Analog Scale (VAS) scores were significantly lower in group H than in group N. There were no significant differences in the overall incidence of pruritus, nausea and sedation between the two groups. Conclusions: Continuous epidural infusion of naloxone combined with hydromorpho-ne is not effective in reducing the incidence and severity of pruritus induced by epidural hydromorphone.

• Korean Journal of Environmental Agriculture
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• v.17 no.4
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• pp.329-334
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• 1998

This study was conducted in order to investigate removal rate of organic matter, nitrogen and phosphorus to reduce environmental polluation with treatment to attach combined septic tank to 3 stage soil filter after mixing anaerobic treated water of livestock wastewater and low concentrated wastewater generated in farm house. Because anaerobic filter bed was packed in combined septic tank and a microorganism was accumulated in combined septic tank with increasing hydraulic retention time(HRT), if HRT $4{\sim}12day$, CODcr was removed $63.4{\sim}84.0%$. Also, $NH_4\;^+-N$ and $PO_4\;^{3-}-P$ were removed $3.9{\sim}5.4%$ and $18.3{\sim}29.0%$, respectively. In being re-treated by 3 stage soil filter, although hydraulic loading rate was gradually increased, CODcr, $NH_4\;^+-N$ and $PO_4\;^{3-}-P$ were removed above 90% due to filtration, adsorption, ion exchange, and action of soil microorganism. Generally, the attached treatment of combined septic tank and 3 stage soil filter did suitably treat livestock wastewater to water standard of discharge applied from '96 year, in view of decreasing pollution loading amount and recycling of agricultural water.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.3
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• pp.116-121
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• 2004

Treatability tests were conducted to study the feasibility of EMMC process as a recycling-water treatment system in high density seawater aquaculture farm. To study the effect of organic and ammonia nitrogen loading rate on system performance, hydraulic retention time was reduced gradually from 12hr to 10min. The conclusions are can be summarized as follows. When the system HRT was reduced from 12hr to 2hr gradually, there was little noticeable change(reduction) in ammonia nitrogen removal efficiencies. However, removal efficiencies were decreased dramatically when the system was operated under the HRT of less than 2hr. In case of organics(COD), there was no dramatic change in removal efficiencies depending on HRT reduction. COD removal efficiencies were maintained successfully higher than 9％ when the system was operated at tile HRT of 10 min. System performances depending on media packing ratio in the reactors were also evaluated. There were little differences in each reactor performances depending on media packing ratio in reactor when the reactors were operated under the HRT of longer than 1hr. However, differences in reactor performances were considerably evident when the reactors were operated under the HRT of shorter than 1hr. When comparing reactor performance among 25％, 50％,7 5％ packed reactor, it can be judged that media packing ratio more than 50％ plays no significant role in increasing reactor performance. For this reason, packing the media less than 50％ is more reasonable way in view of economic. Such a tendency shown in COD removal efficiencies well agreed with the variation of ammonia-nitrogen removal efficiencies according to the media packing ratio in reactors at each HRT. Difference in effluent ammonia-nitrogen concentration between 50％ media packing reactor and 75％ media packing reactor was negligible. When comparing with the results of 25％ packing reactor, difference was not so great.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.246-254
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• 2007

Fresh tea leaves grown in Jeju Island and Jeonnam Province of South Korea were plucked and processed. Volatile compounds (VCs) were analyzed and identified with SPME-GC/GC-MS/GC-O. The VCs of green teas were classified into two major categories based on their aroma characteristics: the Greenish (Group I), and Floral (Group II) odorants. It was found that the VCs were decreased significantly in fresh tea leaves as they were plucked at the later stages of cultivation. The ratio of VCs responsible for Group I and Group II compounds was well-balanced in tea leaves plucked in May, but the balances were changed when the fresh leaves were processed. The major VCs of fresh tea leaves in Jeju and Jeonnam were n-hexanal, E-2-hexenal, Z-3-hexenal, myrcene, benzyl alcohol, linalool, and phenyl alcohol. Also, Jeju and Jeonnam tea leaves had different aroma composition. n-Heptanol, ${\beta}-pinene$, benzaldehyde, and ethyl salicylate were found in Jeju fresh tea leaves, and Z-3-hexenol, E-2-hexenol, and methyl n-heptanoate were detected in Jeju dry tea leaves. On the other hand, Z-linalool oxide and myrcene were found in Jeonnam dry tea leaves. The SPME-GC method showed high reproducibility (RSD, 7.4%) with no-artifact formation. In this study, optimum plucking period of tea leaves could be determined for production of high quality green tea with a well-balanced aroma and characteristic VCs in green tea according to growing areas.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.1
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• pp.7-14
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• 2006

In this study, nitrogen removal characteristics of SBR3 process, which is two-sludge system of sequencing batch reactor(SBR) type, were investigated, with comparison of those of SBR1 process, which is conventional SBR process, and SBR2 process, which was designed to enhance denitrification efficiency through step-feeding of wastewater, using domestic wastewater. SBR3 process of two-sludge type can perform external nitrification, on which nitrification occurs in separated reactor, and enhanced denitrification using biosorbed organics. In the results with domestic wastewater, T-N removal efficiency of SBR3 process was better than those of SBR1 and SBR2 processes. It was observed that bigger difference of T-N removal efficiency between SBR3 process and SBR1 & SBR2 processes was showed at low C/N ratio than that at high C/N ratio resulting from more efficient use of organics by biosorption mechanism in denitrification of SBR3 process than those of SBR1 and SBR2 processes. In addition, T-N removal efficiency of SBR3 process according to influent T-N loading rate was better than those of SBR1 and SBR2, even though influent T-N loading rate of SBR3 process was higher than that of SBR1 and SBR2 process resulting from operation of SBR3 process in short hydraulic retention time(HRT) by external nitrification.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.1
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• pp.1-6
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• 2006

Biological nutrient removal(BNR) process used in this study, which was packed with EPS(expanded polystylene) media, has more many advantages in aspect of reducing hydraulic retention time(HRT) of the process and having less effect of temperature in the winter season than commercial process in the present. Bench-scale study was performed using domestic wastewater. In the results, it was observed that the T-N removal efficiencies in HRT 6 hr and HRT 4 hr were 55% and 51%, respectively, showing the small reduction (about 4%) of T-N removal efficiency according to shortening of HRT. In comparison of T-N removal characteristic in summer and winter seasons, it showed that T-N removal efficiencies in summer and winter seasons were 65% and 54%, respectively, showing the 11% lower T-N removal efficiency in winter season than in summer season due to deterioration of nitrification in winter season. In the studies of influent loading rate and C/N ratio, the process showed stable effluent quality under the condition of broad influent loading rate and C/N ratio. Therefore, it is anticipated that the developed process in this study could be applicable to small wastewater treatment plant in nutrient removal.