• Journal of Korean Society of Water and Wastewater
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• v.24 no.4
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• pp.369-376
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• 2010

The purpose of this study is to reprocess Waste-LCD(Liquid Crystal Display), to widely increase specific surface-area by foaming agent in the process of reprocessing and to use as a substrate of water treatment which is increased the ability of biological treatment, as well as to control non-point source pollutants produced by surface run off during rainfall with using this substrate, and to improve water quality of public watershed as developing substrate for water treatment to be able to purify second treated water which is exhausted at the wastewater treatment plant. The average removal efficiency of Waste-LCD that using the foaming technology was SS 71.2%, BOD 55.7%, COD 58.4%, T-N 29.5% and T-P was 50.3%. Almost Media, early stage showed low removal efficiency of SS and BOD. However, it became high when the microorganism adhered the Media. The variation of SS removal efficiency was high by inflow concentration of SS. The reason for the Media 4 showed high SS removal efficiency is that it has wide specific surface-area, and also it has a pore. All in all, it shows floating matter treatment ability not only inside but it also works outside of the substrate.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.178-186
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• 2011

This study was conducted to investigate runoff characteristics of non-point pollutant sources in an agricultural area watershed in Boeun area, Chungbuk Province. The monitoring site represented 1.56 $km^2$, about 44.4% of which was covered with paddy fields. The monitoring was conducted for six events in a period of 5 month. Event Mean Concentration (EMC) and Site Mean Concentration (SMC) of suspended solids (SS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (T-N) and total phosphorus (T-P) were calculated using the results of the water quality parameters. A comparison between arithmetic mean concentration and EMC revealed that nearly all EMCs were higher than the corresponding arithmetic mean concentrations. First-flushing effects were exhibited for SS, BOD, and T-P, with relatively high concentrations in early-stage storm events.

• The Journal of Korean Society for School & Community Health Education
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• v.13 no.1
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• pp.77-87
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• 2012

This study is a descriptive paper addressing the relationship between test anxiety, self-esteem and the mental health levels of freshmen and third year students of Dental Hygienics. In late 2011, we received a total of 298 questionnaires from freshmen and third year Dental Hygienics students of three South Korean universities, located specifically in Seoul and Gyeonggi-do. The timing of this questionnaire was significant because it was one week prior to midterm examinations. The results were as follows:1. There was a statistically significant relationship between age (t=3.017, p<.001) and grade(t=2.665, p<0.05), subjective health status(t=27.513, p<.001). 2. The lower the participants' reported mental health in general, the higher their level of test anxiety (r=.565, p<.001), broken down into two subdivisions: cognitive text anxiety (r=526, p<.001) and emotional test anxiety (r=.534, p<.001). 3. When considering the factors that influence the general mental health of participants, there were age differences. For first year students, their subjeetive health status (${\ss}$=-.300, p<.001) and test anxiety (${\ss}$=.530, p<.001) were significant. For third year students, this was also true (subjective mental condition: ${\ss}$=-.242, p<.001 and test anxiety: ${\ss}$=.350, p<.001) but self-worth was also significant (${\ss}$=.377, p<.001). The results of this study suggest that the key factors that influence the mental health level of students Dental Hygienics are test anxiety, subjective appraisal of health level, and general self-worth. A systematic approach is therefore needed to improve students' mental health and reduce test anxiety. Health management programs which address and test students' physical health will also be important in improving student performance and welfare.

• Journal of Korean Society on Water Environment
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• v.34 no.2
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• pp.202-209
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• 2018

The purpose of this study was to analyze the correlation between the effluent of a sewage treatment plant (STP) and the adjacent stream located downstream of the STP in Nakdong River. Flow and water quality data, such as BOD, COD, SS, T-N, and T-P data, for 12 STPs and adjacent downstream monitoring stations in the main stream and tributaries of Nakdong River were collected from 2012 to 2015. As a result of correlation analysis between river flow and water quality at the river water quality measurement point, COD, SS, and T-P were correlated positively with the river flow rate at 6, 8, and 6 points, respectively. As a result of analyzing the water quality of sewage treatment plant effluents and downstream streams, BOD and COD were correlated at 2 and 3 points, respectively. T-N showed a positive correlation at 9 points, and 7 of them had a strong positive correlation, indicating that sewage treatment effluent had a large effect on downstream streams. In this study, we found that the correlation between the river flow rate and the water quality factors (COD, SS, TP) was high at river water measurement points, and the sewage treatment plant effluent was correlated with the T-N value of adjacent streams.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.493-493
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• 2018

The purpose of this study was to analyze the correlation between the effluent of the sewage treatment plant (STP) and the adjacent stream located downstream of the STP in Nakdong River. The flow and water quality such as BOD, COD, SS, T-N, and T-P data for 12 STPs and adjacent downstream monitoring stations in the main stream and tributaries of Nakdong River were collected from 2012 to 2015. As a result of correlation analysis between river flow and water quality at the river water quality measurement point, COD, SS and T-P were correlated positively with river flow rate at 6, 8, and 6 points, respectively. As a result of analyzing the water quality of sewage treatment plant effluent and downstream stream, BOD and COD were correlated at 2 and 3 points, respectively. T-N showed a positive correlation at 9 points, and 7 of them had a strong positive correlation, indicating that sewage treatment effluent had a large effect on downstream streams. In this study, we found that the correlation between river flow rate and water quality factors (COD, SS, TP) was high for river water measurement points, and the sewage treatment plant effluent was correlated with the T-N value of adjacent streams.

• Animal Bioscience
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• v.34 no.4
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• pp.692-700
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• 2021

Objective: This study aimed to determine the effect of dietary selenium (Se) from Se-enriched kale sprout (SeKS), selenomethionine (SeMet), and sodium selenite (SS) on performance, carcass characteristics and Se concentrations in the tissues, and to study the relationship between Se concentrations in muscle and feather in growing quails. Methods: The 320 quails (7 d of age) were divided into four treatments, according to a completely randomized design. The treatments were T1: control diet; T2, T3, and T4: control diets plus 0.2 mg Se/kg from SS, SeMet, and SeKS, respectively. The performance, carcass characteristics, and Se concentrations in the tissues of quails were determined. Results: The results indicated no effect (p>0.05) of Se supplementation on performance, carcass characteristics and glutathione peroxidase (GSH-Px) activity in breast muscle of quails. Supplemental Se from SS, SeMet, and SeKS increased greater (p<0.05) Se concentrations in breast muscle, liver, kidney, heart, and feather, compared to those of quails fed the control diet. Quails fed Se from SeMet had greater (p<0.05) Se concentrations in the tissues than quails fed Se from SeKS and SS. In addition, Se concentrations in breast muscle and feather of quails at 21 and 42-d-old were highly correlated (R2 0.714 to 0.756) (p<0.05). Conclusion: Performance, carcass characteristics and GSH-Px activity in breast muscle of quails were not affected (p>0.05) by dietary Se supplementation. The Se from SeMet was more effective in increasing Se concentrations in the tissues of quails than Se from SeKS and SS. Feather Se concentrations of 21 and 42-d-old quails can be used for assessment of Se bioavailability of Se sources.

• Imaging Science in Dentistry
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• v.45 no.3
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• pp.159-168
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• 2015

Purpose: This study was performed to compare the metal artifacts from common metal orthodontic brackets in magnetic resonance imaging. Material and Methods: A dry mandible with 12 intact premolars was prepared, and was scanned ten times with various types of brackets: American, 3M, Dentaurum, and Masel orthodontic brackets were used, together with either stainless steel (SS) or nickel titanium (NiTi) wires. Subsequently, three different sequences of coronal and axial images were obtained: spin-echo $T_1$-weighted images, fast spin-echo $T_2$-weighted images, and fluid-attenuated inversion recovery images. In each sequence, the two sequential axial and coronal images with the largest signal-void area were selected. The largest diameters of the signal voids in the direction of the X-, Y-, and Z-axes were then measured twice. Finally, the mean linear values associated with different orthodontic brackets were analyzed using one-way analysis of variation, and the results were compared using the independent t-test to assess whether the use of SS or NiTi wires had a significant effect on the images. Results: Statistically significant differences were only observed along the Z-axis among the four different brands of orthodontic brackets with SS wires. A statistically significant difference was observed along all axes among the brackets with NiTi wires. A statistically significant difference was found only along the Z-axis between nickel-free and nickel-containing brackets. Conclusion: With respect to all axes, the 3M bracket was associated with smaller signal-void areas. Overall, the 3M and Dentaurum brackets with NiTi wires induced smaller artifacts along all axes than those with SS wires.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.9
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• pp.469-475
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• 2016

The study is the result of an practical operation analysis for the full scale fishery product wastewater treatment plant with immersed MBR (iMBR) process. Since fishery product industries show a wide range of wastewater generation by the season, design and operation of the equalization basin are very important factor. The aeration system for the equalization basin mixing can save the chemical consumption for followed system through the restriction of acid fermentation. The concentrations of wastewater primary DAF process treated were BOD 2,291 mg/L, $COD_{Mn}$ 530 mg/L, SS 256.8 mg/L, T-N 38 mg/L, T-P 13.5 mg/L respectively. It was considered that iMBR is the most efficient biological process for high salinity content wastewater since It is irrelevant to the capability of the sludge precipitation. SADp and SADm were 0.31, $26.5m^3/hr{\cdot}m^3$ respectively. In iMBR process, the critical F/M ratio was derived at 0.08~0.10 gBOD/gMLSS by analysing the correlations between MLSS, normalized TMP and temperature. The effluent concentrations were BOD 1.8 mg/L, $COD_{Mn}$ 12.4 mg/L, SS 1.0 mg/L, T-N 7.85 mg/L, T-P 0.1 mg/L and removal efficiencies were 99.9%, 97.6%, 96.3%, 95.7%, 97.8% respectively.

• Journal of Wetlands Research
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• v.11 no.1
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• pp.115-121
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• 2009

The hybrid constructed wetland(HCW) as tertiary treatment process of a bio industrial wastewater treatment plant was employed to estimate applications for the reuse of final effluent. Raw wastewater was sequently treated through chemical and biological treatment processes and the biologically treated water was flowed into the HCW. The HCW system was composed of two constructed wetlands connected in series; The one is the aerobic constructed wetland with natural air draft system whose driving force for air supply was the difference between the temperature of the air inside the wetland and the ambient air, and the other is the anaerobic/anoxic constructed wetland. Average influent concentrations of BOD, SS, T-N and T-P in the HCW were 53mg/L, 48mg/L, 34mg/L and 3mg/L, respectively. After being treated at HCW, final effluent concentrations of BOD, SS, T-N and T-P were 2.3mg/L, 1.2mg/L, 7.95mg/L and 0.83mg/L, respectively. Referring to a reuse standard for a sewage wastewater, final effluent could sufficiently be reuse as landscaping, washing or agriculture water. HCW system with the aerobic/anaerobic combined constructed wetland could be achieved a high removal efficiency because each constructed wetland was functionalized to be removed efficiently organics, nitrogen and phosphorus. HCW system could be estimated to be successful application as tertiary treatment process of a various industrial and municipal wastewater.

• Journal of Animal Environmental Science
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• v.10 no.2
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• pp.81-86
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• 2004

This experiment was conducted to evaluate combination system of wood chip trickling system and activated sludge process. The results obtained are summarized as tallows. The trickling filter system using wood chip was used as a biological pre-treatment system for treating piggery wastewater. At pre-treatment the removal efficiencies were BOD $91\%$ CODmn $65\%$, SS $75\%$ T-N $73\%$, T-P $69\%$. After pre-treatment the removal efficiencies in activated sludge process were BOD $99\%$ CODmn $94.6\%$, SS $97.8\%$ T-N $91.1\%$, T-P $91\%$. This study shows a very stable method with pre-treatment of trickling filter using wood chip. These combined treatment system was very useful for piggery wastewater.