• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2000.11a
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• pp.18-18
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• 2000

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2000.11a
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• pp.26-26
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• 2000

• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.903-913
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• 1996

총 15두의 초유를 섭취하지 않은 신생자견을 대상으로 난황항체를 경구투여한 후 개 파보바이러스를 경구 접종하여 실험감염을 유발시켜 난황항체의 수동 면역에 의한 예방효과를 알아보고자 한다. 항체역가는 면역화된 산란계로부터 분리한 난황항체를 투여한 자견이 비면역 난황항체를 투여한 자견에 비해 높았다. 개 파보바이러스 접종 직전의 항체역가는 대조군의 경우 1:40에서 1:80, 실험군의 경우는 1:320에서 1:1280이었다. 모든 대조군의 자견들은 바이러스 접종후 4일에 임상증상을 나타내었고 총 7두중 6두가 폐사된 반면 실험군 자견은 2두만이 증상을 나타내었고 폐사 자견은 없었다(p<0.01). 개 파보바이러스를 경구 접종한 후 전체 자견의 혈구응집억제반응역가는 접종후 6일까지 감소하는 경향을 보였다. 접종후 5일의 분변내 혈구 응집반응역가는 실험군 자견의 경우 < 2에서 64였으며 대조자견은 216에서 2048로 높았다.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.3
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• pp.212-221
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• 2011

Wastewater treatment plants (WWTPs) are required to meet the reinforced discharge standards which are differentiated as 0.2, 0.3 and 0.5 mg-TP/L for the district I, II and III, respectively. Although most of WWTPs are operating advanced biological phosphorus removal system, the supplementary phosphorus treatment facility using chemical addition should be required almost at all WWTPs. Therefore, water quality data from several exemplary full-scale plants operating phosphorus treatment process were analyzed to evaluate the reliability of removal performance. Additionally, a series of jar tests were conducted to find optimal coagulants dose for phosphorus removal by chemical precipitation and to describe characteristics of the reaction and sludge production. Chemical costs and the increasing sludge volume in physicochemical phosphorus removal process were estimated based on the results of jar tests. The minimum coagulant (aluminium sulfate and poly aluminium chloride) doses to keep TP concentration below 0.5 and 0.2 mg/L were around 25 and 30 mg/L (as $Al_2O_3$), respectively, in the mixed liquor of activated sludge. In the tertiary treatment facility, relatively lower coagulant doses of 1/12~1/3 the minimum doses for activated sludge were required to achieve the same TP concentrations of 0.2~0.5 mg/L. Increase in suspended solids concentration due to chemical precipitates in mixed liquor was estimated at 10~11%, compared to the concentration without chemical addition. When coagulant was added into mixed liquor, chemical (aluminium sulfate) cost was estimated to be 4~10 times higher than in secondary effluent coagulation/separation process. Sludge production to be wasted was also 4~10 times higher than secondary effluent coagulation/separation process.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.8
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• pp.549-556
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• 2012

T-P removal efficiency was analyzed according to the metal to initial T-P ratio (mole basis) with respect to the samples from different WWTPs having various initial T-P and SS conditions. Also, operating costs were calculated based on the injected coagulant amount and the amount of sludge production. Most experiments were conducted by the standard jar-test protocol. Molar ratio of coagulant dose was varied considerably according to the initial SS concentration range in secondary clarifier effluent samples which had above 0.5 mg/L of initial T-P. Based on 90% T-P removal efficiency, results were: At the initial SS range of below 10 mg/L, Alum (8%) = 11 mol Al/mol P needed and PAC (17%) = 9.6 mol Al/mol P needed; At the initial SS range of above 10 mg/L, Alum (8%) = 3.9 mol Al/mol P needed and PAC (17%) = 3.2 mol Al/mol P needed.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.7
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• pp.483-491
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• 2014

In this study, we developed an M-COS (molit coagulant-dosing optimization system), which enables to apply the optimum coagulant dose determined in real time, in order to satisfy the total phosphorus (TP) regulation (0.5 mg/L), and then tested its field applicability. Field tests were conducted at three different periods in 2014 in a pilot plant where the M-COS was installed. Coagulant reduction rate by the M-COS was 10.4%, 15.3%, and 9.0% for each period (average 11.6%), when comparing with a control where coagulants were applied at a constant rate. Total cost for the M-COS or control was estimated by summing up the coagulant cost and sludge treatment cost, and then the resulting cost increase was predicted. Cost reduction rate by the M-COS was 13.8%, 20.0%, and 11.4% for each period (average 15.0%). This study indicates that the M-COS can be an alternative to a conventional system for TP treatment, with a better cost efficiency.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.877-882
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• 2013

The application of ultrafiltration (UF) and microfiltration (MF) membranes has been increased for drinking water purification. The advantages of UF/MF membrane process compared to conventional treatment processes are stable operation under varying feed water quality, smaller construction area, and automatic operation. Most membrane treatment plants are designed with polymeric membranes. Recently, some studies suggested that the process of treating surface water with ceramic membranes is competitive to the application of polymeric membranes. Higher water flux, less frequent cleaning, and much longer lifetime are the advantages of ceramic membrane comparing to polymeric membrane. Therefore, this research focused on the application of ceramic MF membrane pilot plant at the slow sand filtration plant. The ceramic membrane pilot plant has three trains that used raw water and sand filtered water as a feed water, respectively. For optimizing the pilot plant process, the coagulation with PACl coagulant was used as a pretreatment of ceramic membrane process. In addition, CEB (Chemical Enhanced Backwash) process using $H_2SO_4$ and NaOCl was used for 1.5 days, respectively. The experimental results showed that applying the optimum coagulant dose before membrane filtration showed enhancing membrane fluxes for both raw water and sand filtered water. Also, when using raw water as a feed of membrane, minimum fouling rate was 2.173 kPa/cycle with 25 mg/L of PACl and when using sand filtered water, the minimum fouling rate was 0.301 kPa/cycle with 5 mg/L of PACl.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.5
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• pp.468-473
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• 2014

This study is unrefined ZnO, $TiO_2$ nanoparticles is expose M4 medium to search nanoparticle aggregation and Daphnia magna was any effect by immobilization and mortality. ZnO and $TiO_2$ nanoparticle powder-size is respectively 20 nm and 40 nm. but, M4 medium has about respectively as 1333 nm and 1628 nm, 40 to 70 times were agglomerated. Immobilization of ZnO and $TiO_2$ nanoparticles was influenced both time and concentration the higher to swimming of D.magna. Especially, The immobilization of D.magna in nano-ZnO is greater than that influence in nano-$TiO_2$. Mortality of ZnO nanoparticle is higher rate at long time and high concentration. $TiO_2$ nanoparticle observed mortality at 10ppm concentration after 72h. Consequently, when Nanoparticles is introduced into ocean. Particle size become grow. Additionally, aggregation be caused affect aquatic ecosystems.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.558-566
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• 2019

The purpose of this study is to fine out whether melodic percussion playing group program affects the team cohesion and team efficacy of youth soccer players. In this study fifty seven middle school soccer players were participated. The participants were assigned to either a melodic percussion playing group or a control group. In order to identify the effectiveness of music program, assessments were conducted using the team cohesion and team efficacy scales before and after the program. The results of comparison analysis through t-test are as follows. First, in the posttest of team cohesion between groups, the experimental group showed a significant difference over the control group. In the pretest and posttest examinations within a experimental group, the group also showed a significant difference. Second, in the posttest of team efficacy between groups, the experimental group showed a significant difference over the control group. In the pretest and posttest examinations within a experimental group, the group also showed a significant difference. These results of this study suggest that melodic percussion playing group program may be an effective intervention tool to improve team cohesion and team efficacy of youth soccer players.

• Journal of Environmental Science International
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• v.7 no.6
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• pp.761-772
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• 1998

This study was performed to determine the optimum coagulant dosing amount for effective treatment of raw water. The removal rate of turbidity and the variations of water qualities according to various dosage of coagulants such as Alum, PAC and PACS were investigated. The optimum coagulant dosing amount to make the lowest turbidity of water were 35mg/ι t of Alum, 30mg/ι of PAC and 10mg/ι of PACS in case of 5 NTU of raw water turbidity, and 30mg/ι of Alum, 25mg/ι of PAC and 10mg/ι of PACS in case of 10 NTU of that, respectively. The removal rates of turbidity at 4 min. and 8 min. of settling time were 10 and 72% of Alum, 44 and 62% of PAC and 25 and 55% of PACS in case of 5 NTU, and 52 and 70% of Alum, 90 and 95% of PAC and 10 and 28% of PACS in case of 10 NTU, respectively. Judging from the settling capability of floc., the reaction time of floe. formation and removal efficiency of turbidity, PAC was evaluated as more effective coagulant than Alum and PACS. Also PAC was regarded as the most effective coagulant when the water supply was changed sharply and the fluctuation of the surface loading occured with wide and sharp in settling basin. pH and alkalinity of the water were decreased with increasing coagulants dosage. But pH and alkalinity were not decreased below 5.8 which is the standard for drinking water quality, and 10mg/ι which is the limit concentration of floc. breakage, respectively. Residual Al of the treated water was decreased with increasing coagulants dosage in case of 5 and 10NTU of raw water turbidity. $KMnO_4$ consumption of the water was decreased with increasing coagulants dosage. The reduction rate of $KMnO_4$ consumption at the optimum coagulants dosage were 39% of Alum. 18% of PAC and 11% of PACS in case of 5 NTU of raw water turbidity, and 42% of Alum, 27% of PAC and 36% of PACS in case of 10 NTU of that, respectively. Any relationship was not found between the removal rate of turbidity and KMnO$_4$ consumption. TOC of the water was a bit decreased with increasing coagulants dosage up to 30mg/ι but not changed above 30mg/ι of coagulants dosage. The degree of TOC reduction was increased in the order of Alum, PAC and PACS treatment. Zeta potential of the colloidal floe. at the optimum coagulants dosage was in the range of -20~-15mV in case of 5 NTU of raw water turbidity and 0~0.5mV in case of 10 NTU of that. respectively. Although the kinds and dosages of coagulants were different, zeta potential range were fixed under the conditions of the best coagulation efficiency.