• Journal of Korean Society on Water Environment
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• v.30 no.1
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• pp.1-7
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• 2014

The purpose of this study was to investigate the nitrification characteristics of biological aerated filter (BAF) packed with ceramic media, especially focusing on nitrite build-up during nitrification. When increasing the nitrogen load above $1.63kgNH_4{^+}-N/m^3{\cdot}d$, ammonium removal efficiency decreased to less than 60% and the nitrite ratio ($NO_2{^-}-N/NO_x-N$) of higher than 75% was achieved due to the inhibitory free ammonia (FA, $NH_3-N$) concentration and oxygen limitation. FA inhibition, however, is not recommended strategy to promote nitrite build-up since FA concentration in the reactor is coupled with decreased ammonium removal efficiency. Nitrite ratio in the effluent was also affected by aeration rate and influent ammonium concentration. Ammonium oxidation was enhanced at a higher aeration rate regardless of influent ammonium concentration but, the nitrite ratio was dependent on both aeration rate and influent ammonium concentration. While a higher nitrite ratio was obtained when BAFs were fed with $50mgNH_4{^+}-N/L$ of influent, the nitrite ratio significantly decreased for a greater influent concentration of $200-300mgNH_4{^+}-N/L$. Taken together, aeration rate, influent ammonium concentration and FA concentrations kept in the BAF were found to be critical variables for nitrite accumulation in the BAF system.

• Journal of Life Science
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• v.9 no.2
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• pp.201-206
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• 1999

Nitric oxide(NO) is a potent and selective pulmonary artery vasodilator. Erythropoietin(EPO) is produced in the kidney in response to reduced oxygen availability. In this study, blood samples were collected for determination of NO and EPO concentrations in 18 normal newborns and 16 newborns with respiratory distress syndrome(RDS). Serum was measured by Ding's method for NO concentration and by enzyme-linked immunosorbant assay for EPO concentration. Nitric ion concentration in serum was 14.9$\pm$3.2 $\mu$M in normal control group and 12.8$\pm$3.3 $\mu$M in RDS group. EPO concentration in serum was 16.2$\pm$3.4 mU/ml in normal control group and 21.2$\pm$5.4 mU/ml in RDS group. These results show the decrease of NO and increase of EPO in RDS newborn patients in comparison with normal newborns. Such imbalances may contribute to the development of several clinical symptoms.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.157-165
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• 2005

This study was conducted to determine optimum design parameters in nitrification and denitrfication of chemical fertilizer wastewater using pilot plant, Jet Loop Reactor. The chemical fertilizer wastewater which contains low amounts of organic carbon and has a high nitrogen concentration requires a post-denitrfication system. Organic nitrogen is hydrolyzed above $86\%$, and the concentration of organic nitrogen was influent wastewater 126mg/L and of effluent wastewater 16.4mg/L, respectively. The nitrification above $90\%$ was acquired to TKN volumetric loading below $0.5\;kgTKN/m^3{\cdot}d$, TKN sludge loading below $0.1\;kgTKN/kgVSS{\cdot}d$ and SRT over 8days. The nitrification efficiency was $90\%$ or more and the maximum specific nitrification rate was $184.8\;mgTKN/L{\cdot}hr$. The denitrification rate was above $95\%$ and the concentration of $NO_3-N$ was below 20mg/L. This case was required to $3\;kgCH_3OH/kgNO_3-N$, and the effluent concentration of $NO_3^--N$ was below 20mg/L at $NO_3^--N$ volumetric loading below $0.7\;kgNO_3^--N/m^3{\cdot}d$ and v sludge loading below $0.12\;kgNO_3^-N/kgVSS{\cdot}d$. At this case, the maximum sludge production was $0.83\;kgTS/kgT-N_{re}$ and the specific denitrfication rate was $5.5\;mgNO_3-N/gVSS{\cdot}h$.

• Journal of Environmental Science International
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• v.28 no.7
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• pp.595-606
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• 2019

This research investigated the characteristics of CO, $CO_2$, and $NO_2$ concentrations at main subway stations in Busan. The annual mean CO concentrations at the Suyeong and Nampo stations were 0.75 ppm and 0.48 ppm, respectively. Annual $CO_2$ concentration at the Seomyeon 1- platform was 649 ppm. The $NO_2$ concentrations at the Seomyeon 2- waiting room and the Yeonsan station were 0.048 ppm and 0.037 ppm, respectively. CO concentration was highest at two times of the day, and was proportional to the number of passengers commuting to and from work. The CO and $CO_2$ concentrations were highest in winter, but $NO_2$ concentration was highest in spring. CO and $CO_2$ concentrations were highest on Saturday and lowest on Sunday. The correlation of CO and $NO_2$ concentrations measured at the subway stations with those at the ambient air quality station were highest at the Seomyeon 1 and 2- waiting room and Jeonpodong. The correlation was lowest at the Yeonsan and Yeonsandong station. The number of days when $CO_2$ concentration exceeded 700 ppm over the last three years at the Seomyeon 1- platform was 174. The findings of this research are expected to deepen understanding of the fine particle characteristics at subway stations in Busan and be useful for developing a strategy for controlling urban indoor air quality.

• Journal of Environmental Science International
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• v.10 no.3
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• pp.187-194
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• 2001

For the purpose of predicting air pollutants concentration in Pusan coastal urban, we used an Eulerian model of flow and dispersion/chemistry/deposition process considering SST effects which estimate through POM. The results of air quality model including emission from various sources show that the seasonal variation pattern of respective pollutants was affected by the seasonal SST fields and local circulation. Horizontal deviation of diurnal SST was 2.5~4K, especially large gradients in coastal region. Through numerical simulation of wind fields we predicted that local circulation prevailed during daytime in summer and nighttime in winter. So high concentration distribution showed toward inland in spring and summer seasons, while high concentration distribution showed at inland near coast in autumn and winter.

• Journal of the Korean Ceramic Society
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• v.33 no.5
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• pp.495-506
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• 1996

Monodispersed colloidaly yttria(Y2O3) can be used in a variety of applications such as phosphors. IR transparent materials and fine ceramics. For preparing monodispersed yttria homogeneous precipitation has been regarded as a fovorable method that is monodispersed yttria can be obtained through calcining monodispersed colloidal compound of yttrium (eg:Y(OH)CO3.nH2O)which can be prepared by homogeneous precipitation with urea. It is however still required to find out the quantitative effects of important variables of precipitation such as concentration of yttrium and urea reaction temperature and initial pH of reactant even though homogeneous precipitation of Y3+ with urea has been studied extensively. Among the effects of these variables we investiga-ted 1) the effect of yttrium concentration on the shape and size of precipitate and the reation rate 2) range of yttrium concentration required to make monodispersed colloidal particles 3) the reason for limited concentra-tion range of yttrium and 4) the effect of ultrasonic radiation on the limited concentration.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.5
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• pp.431-438
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• 2000

The physical and processing properties of acorn jelly were investigated to see the effect of polysaccharides in seaweed extract and corn starch. The yield of acorn jelly added starch concentration was slightly increased when the concentration was added more. However, moisture content and color had no significant changes with concentration. In the case of acorn jelly added sea tangle, color of acorn jelly was darker, but color of the jelly with carrageenan was lighter. According to the concentration of seaweed extract, the hardness was increased as concentration was added. The texture of acorn Jelly added agar had the highest binding. In the case of acorn jelly added corn starch, there were no significant changes, but this binding was stronger than the acorn jelly added extract of marine algae. In the physical and sensory properties of acorn jelly with corn starch, the ideal mixture ratio between the acorn jelly and the corn starch was 6:4.

• Fashion & Textile Research Journal
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• v.5 no.3
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• pp.283-288
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• 2003

Large quantity of metal mordant in natural dyeing has been used. For environmental reason, there is a need to reduce the amount of metal mordant and suggest the optimum amount of metal mordant in dyeing process. In this study, the relationship between mordant concentration and dyeing property was investigated. Various metal mordant concentrations of AI, Cu, Fe, Sn, were studied (from 1 to 5%). After treatment of mordant on cotton fabric, the concentration of metal ion in used mordant solution was quantified. There was no significant difference of the tone of color in mordant concentration from 1% to 5%, Therefore, there is no need to increase mordant concentration over 1%. chitosan treated cotton fabric showed a significant increase in dyeing affinity compared to untreated cotton fabric (the value of ${\Delta}E$ was 20). chitosan increased dye affinity significantly in the presence of mordant. It can be suggested that chitosan itself can replace metal mordants in the future.

• Korean Journal of Plant Resources
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• v.20 no.6
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• pp.544-547
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• 2007

The effects of hwangryun(Coptidis Rhizoma) on lowering lipid and oxidative stress in the induced obesity rat was observed. The concentration of plasma triglyceride in hwangryun treatment groups showed the low values compared to the control group, and as the increased hwangryun, the concentration of triglyceride decreased. The concentration of plasma total cholesterol decreased in all hwangryun treatment groups. However the concentration of plasma HDL-cholesterol and LDL-cholesterol showed no significantly difference in all the treatment groups. Thiobarbituric acid reactive substance(TBARS) concentration in plasma and liver showed low values in all hwangryun treatment groups compared to the control group. Glutathione peroxidase(GSH-Px) and superoxide dismutase(SOD) activities showed no significantly difference in all the treatment groups. However catalase(CAT) activity showed a tendence to increase in hwangryun groups, and in 200mg/kg hwangryun treatment group showed significantly a high value than the control group. Summarizing the results above, hwangryun has the functional materials that lowering lipid and works with oxidative stress.

• Korean Journal of Plant Resources
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• v.21 no.6
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• pp.457-461
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• 2008

Effects of Gal geun (Puerariae Radix) EtOH ext. on lipid lowering and antioxidant were investigated in hyperlipidemic rat. Concentration of FFA and triglyceride in plasma showed a tendency to decrease in Gal geun ext. groups. Concentration of plasma total cholesterol and LDL-cholesterol decreased in Gal geun ext. groups. However the concentration of HDL-cholesterol showed no significantly different in all treatment groups. Concentration of liver total cholesterol and triglyceride showed a tendence to decrease in Gal geun ext. groups. Concentration of plasma and liver TBARS showed a low values in Gal geun ext. groups. The values of GSH-Px and SOD activity showed no significantly different among all the treatment groups. However the values of SOD and CAT activity showed a high value in the Gal geun ext. groups.