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  • Title/Summary/Keyword: evaluation of school environment

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Evaluation of Nutrients Removal Efficiency in Effluents of Sewage and Wastewater using Microalgae (미세조류를 이용한 오·폐수 영양염류 제거효율 평가)

  • Kim, Sook-chan;Kim, Han-soon
    • Korean Journal of Ecology and Environment
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    • v.50 no.2
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    • pp.187-194
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    • 2017
  • This study was intended to evaluate the removal efficiency of nutrients in effluents of wastewater using microalgae. Microalgae used in the culture experiment collected in stream and reservoir located in Gyeongsangbuk-do. Dominant species in prior-culture tank were Monoraphidium contortum, Scenedesmus acutus, Coelastrum microporum and Chlorella sp. Dominant species in synthetic wastewater culture under the 4000 Lux and 8000 Lux were Chlorella sp. and Scenedesmus obliquus. The removal efficiency of NO3N under the 4000 Lux and 8000 Lux were 27.2%~88.1% and 63.0%~83.6% respectively. The removal efficiency of PO4P under the 4000 Lux and 8000 Lux showed above 93%. Removal efficiency of nutrients of 1.0×106cellsmL1 inoculation concentration was more higher than that of nutrients of 1.0×105cellsmL1 and 1.0×107cellsmL1 inoculation concentration. Microalgae cultured in synthetic wastewater removed 94.9% of TN and 90.0% of TP. The removal rate of TN and TP in synthetic wastewater were 1.961mgL1day1 and 0.200mgL1day1 respectively. Nutrient removal efficiency of microalgae according to kinds of wastewater showed the highest in the private sewage.

Analysis on the Status of Joint Forestry Project in National Forest (국유림 공동산림사업 실태분석에 관한 연구)

  • Kim, Dong-Hyeon;Ko, Chi-Ung;Kim, Dong-Geun
    • Journal of agriculture & life science
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    • v.53 no.6
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    • pp.45-53
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    • 2019
  • The purpose of this study is to analyze the status of the joint forest project, which is one of the national forest management system, by using stakeholder participation, transparency of decision making, accountability of actors and stakeholders, The questionnaire survey was conducted using the 5 - point scale and the written form. As a result of the questionnaire survey, various stakeholder participation items had the highest opportunity to participate with an average of 3.3 and the lowest score with 2.3 points for establishing conflict and conflict resolution structures. Transparency was analyzed to be 3.4 points for the project disclosure, 2.7 points for information sharing and education promotion activities for local residents, 3.3 points for the detailed role of the project implementer, and 2.7 points for internal and external monitoring and evaluation of the project with various stakeholders. The results of this research, analyzed through the participatory forest management index, are deemed to be used as basic data for the establishment of a plan for the revitalization of national forest participation management.

Evaluation of Removal Efficiencies of Micropollutants in Wastewater Treatment Plants (산업폐수처리장에서의 미량유해물질 제거율 평가)

  • Lee, In-Seok;Sim, Won-Jin;Oh, Jeong-Eun;Kim, Chang-Won;Chang, Yoon-Seok;Yoon, Young-Sam
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.2
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    • pp.214-219
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    • 2007
  • 66 micropollutants analyses in 9 wastewater treatment plants(WWTPs) along Nak-dong river were implemented to identify the concentrations and removal efficiencies before and after treatment processes. As a result of study, the concentration levels discharged from WWTP effluents to water system were below the water quality criteria and the levels of other studies. The removal efficiencies were 84.6%(DAF/CCR) and 81.6%(AC) for 1,4-dioxane. Phenol, Clphs and PAHs were removed 94.6%, 66.4% and 80.6% respectively by the activated sludge(AS) process. The removal efficiencies of Clbzs were 45.3% for the activated sludge(AS) process and 60.6% for the activated carbon(AC) process. However, other processes besides AS and AC, the removal efficiencies of Clbzs were very low(<20%). The sand filtration(SF) process that could remove particle matters showed the best efficiency for PCDDs / Fs removal(99. However, in case of relatively low PCDDs/Fs concentration level in influent, the removal efficiency was not so high(50.

The Proper Capacity of Anchorage in Ulsan Port with Reference to the Anchorage Operating Rate (울산항 정박지 가동률 분석을 통한 적정 정박지 규모 제안에 관한 연구)

  • Park, Jun-Mo;Yun, Gwi-Ho;Jeon, Hae-Dong;Kong, Gil-Young
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.5
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    • pp.380-388
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    • 2016
  • This study suggests methods to evaluate the availability of anchorage in Ulsan port and determine the proper capacity of future anchorage in accordance with port development. Accordingly, the concept of an Anchorage Operating Rate (AOR) is introduced to evaluate the capacity of anchorage that was available in Ulsan port in 2014. Calculations revealed that the operating rate of all anchorages in Ulsan port did not exceed 100 %. However, in 2020 it is estimated that the AOR at E1 anchorage will be the highest with a rate of 168.3 %, followed by E3 with 131.1 %, E2 with 118.5 % and M with 108.7%. These findings indicate a shortage of anchorage by 2020. In order to decrease the AOR to a level that will not exceed 100 %, in accordance with port development in Ulsan, areas to accommodate an additional 11 ships at E1 anchorage, 1 ship at E2 anchorage, 2 ships at E3 anchorage and 1 ship at M anchorage will be necessary.

Evaluation of a Hydro-ecologic Model, RHESSys (Regional Hydro-Ecologic Simulation System): Parameterization and Application at two Complex Terrain Watersheds (수문생태모형 RHESSys의 평가: 두 복잡지형 유역에서의 모수화와 적용)

  • Lee, Bo-Ra;Kang, Sin-Kyu;Kim, Eun-Sook;Hwang, Tae-Hee;Lim, Jong-Hwan;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.9 no.4
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    • pp.247-259
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    • 2007
  • In this study, we examined the flux of carbon and water using an eco-hydrological model, Regional Hydro-Ecologic Simulation System (RHESSys). Our purposes were to develop a set of parameters optimized for a well-designed experimental watershed (Gwangneung Research Watershed, GN) and then, to test suitability of the parameters for predicting carbon and water fluxes of other watershed with different regimes of climate, topography, and vegetation structure (i.e Gangseonry Watershed in Mt. Jumbong, GS). Field datasets of stream flow, soil water content (SWC), and wood biomass product (WBP) were utilized for model parameterization and validation. After laborious parameterization processes, RHESSys was validated with the field observations from the GN watershed. The parameter set identified at the GN watershed was then applied to the GS watershed in Mt. Jumbong, which resulted in good agreement for SWC but poor predictability for WBP. Our study showed that RHESSys simulated reliable SWC at the GS by adjusting site-specific porosity only. In contrast, vegetation productivity would require more rigorous site-specific parameterization and hence, further study is necessary to identify primary field ecophysiological variables for enhancing model parameterization and application to multiple watersheds.

A Study on the Establishment of Allowable Criteria for Sailing Ships at Offshore Wind Farms (해상풍력발전단지해역 선박 통항 허용기준 설정에 관한 연구)

  • Ohn, Sung-Wook;Lee, Chang-Hyun;Kim, Cheol-Seong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.7
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    • pp.841-847
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    • 2018
  • Since global energy consumption and demand for energy have dramatically risen, a focus on environmental problems and sustainability has become more important. Clean and renewable energy sources such as offshore wind power generation have received attention among new renewable energy options as alternative energy resources. Due to maintenance and operational perspectives, offshore wind farms have been planned for installation in many coastal waters. However, development of offshore wind farms faces interference from existing maritime traffic along the planned areas. In order to safely and effectively govern marine traffic in the vicinity of wind farms and inner areas, standard criteria are suggested to allow vessels to sail the internal waters of offshore wind farm areas. Therefore, the purpose of this study is to establish allowable criteria for sailing vessels and safety zones for offshore wind farms by investigating the local regulations of various offshore wind farm cases overseas. The commended inner safety zone of wind farms is proposed to be a distance of 150 % of the rotation diameter of the wind turbine rotor and a distance of 200 m from the outer wind turbine for the outer safety zone. Besides this, the allowable criteria for sailing vessels within a wind farm is proposed to have an air draft of 14.47 m south-west wind farm sea areas for a minimum margin to avoid hull contact through evaluation of the tide and height of a wind turbine. further studies will be needed to establish vessel sailing criteria among adjacent offshore wind farms as well as vessel sailing criteria within a single offshore wind farm.

A Study on Bilge Pumping Performance of 24,000TEU class Container Ship (24,000TEU급 컨테이너선박의 빌지 펌핑 성능에 대한 고찰)

  • Seo, Jang-Won;Yun, Jeong-In;Lee, Kyoung-Woo;Lee, Won-Ju;Park, Hoyong;Choe, Su-Jeong;Choi, Jae-Hyuk
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.6
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    • pp.1100-1109
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    • 2022
  • Herein, a case study was conducted on the bilge pumping performance of a 24,000TEU class container ship with an overall length of 400m. Although the bilge system of the 24,000TEU class container ship was designed in accordance with the rule requirements of the Classification Society, the bilge system did not satisfy the 2 m/s requirements of SOLAS Reg.II-1/35-1 under the rated flow rate and maximum flow rate conditions of the bilge pump installed in the ship. In particular, assumptions were made that No.1 ~ No.4 cargo holds were flooded and filled entirely by sea water and the evaluation of bilge pumping performance had been performed for No.1 ~ No.4 cargo holds. According to the evaulation results of the, the mean water velocity at the main bilge pipe for No.2, No.3, and No.4 cargo holds did not meet the 2 m/s criterion. To resolve this problem, in this study, the branch bilge pipe in each cargo hold was changed from 150A to 200A and the mean water velocity at the main bilge pipe for No.2, No.3, and No.4 was calculated as 2.479m/s, 2.476m/s, and 2.459m/s, respectively.

Evaluation of Hazardous Zones by Evacuation Scenario under Disasters on Training Ships (실습선 재난 시 피난 시나리오 별 위험구역 평가)

  • SangJin Lim;YoonHo Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.30 no.2
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    • pp.200-208
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    • 2024
  • The occurrence a fire on a training ship with a large number of people on board can lead to severe casualties. Hence the Seafarers' Act and Safety Life At Sea(SOLAS) emphasizes the importance of the abandon ship drill. Therefore, in this study, the training ship of Mokpo National Maritime University, Segero, which has a large number of people on board, was selected as the target ship and the likelihood and severity of fire accidents on each deck were predicted through the preliminary hazard analysis(PHA) qualitative risk assessment. Additionally, assuming a fire in a high-risk area, a simulation of evacuation time and population density was performed to quantitatively predict the risk. The the total evacuation time was predicted to be the longest at 501s in the meal time scenario, in which the population distribution was concentrated in one area. Depending on the scenario, some decks had relatively high population densities of over 1.4pers/m2, preventing stagnation in the number of evacuees. The results of this study are expected to be used as basic data to develop training scenarios for training ships by quantifying evacuation time and population density according to various evacuation scenarios, and the research can be expanded in the future through comparison of mathematical models and experimental values.

Setting Development Priorities of Undeveloped Neighborhood Parks in the Downtown of Cheongju City using a Park Development Pressure Index (공원조성 압력지수를 이용한 공원개발 우선순위 선정 - 청주시 도심 미개발근린공원을 대상으로 -)

  • Ban, Yong-Un;Lee, Tae-Ho
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.4
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    • pp.1-11
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    • 2009
  • This study was intended to set development priorities for five undeveloped neighborhood parks scattered throughout the downtown area of Cheongju City using a PDPI(Park Development Pressure Index). In order to calculate the PDPI, this study employed an additive integration method. The PDPI was graded from 1 to 5, based on the evaluation scores in accordance with nine indicators selected through literature reviews and interviews with public officials. The indicators have been classified into three categories: physical environment, utilization possibility, and facility distribution. The indicators are as follows: 1) 'altitude and inclination' and 'NDVI' as physical environment indicators; 2) 'ratio of residential area', 'forecasted utility population', 'undeveloped period', 'redevelopment near parks', 'ratio of area divided by main streets', reflecting utilization possibility; and 3) 'Distance between Neighborhood Parks' and 'Distribution of alternative facilities' as facility distribution. The following results were found: 1) three neighborhood parks including 'Sagic 2', 'Sachen', and 'Dangsan' were ranked in the first grade of PDPI; and, 2) one neighborhood park 'Samsungdang' was ranked in the fifth grade of PDPI. The above results mean that among undeveloped neighborhood parks, three have been exposed to extremely strong park development pressure, and that while two neighborhood parks have had strong exposure to park development pressure due to potential users according to their close location to Sagic Ro, an east-west main axis of Cheongju City, one neighborhood park has had weak exposure to development pressure because of the close location to 'Chuungbuk National University' and a lack of residential areas, showing a low possibility for development.

Evaluation on Adaptation of Zosia japonica as Effected by Different Green Roof System under Rainfed Conditon (무관수 옥상녹화시스템의 차이에 따른 들잔디 적응성 평가)

  • Ju, Jin-Hee;Kim, Won-Tae;Choi, Woo-Young;Yoon, Yong-Han
    • Journal of Environmental Science International
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    • v.19 no.9
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    • pp.1137-1142
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    • 2010
  • This study proposes a guideline of a green roof system suitable for the local environment by verifying the growth of Zoysia japonica in a shallow, extensive, green roof system under rainfed condition. The experimental soil substrates into which excellent drought tolerance and creeping Z. japonica was planted were made with different soil thicknesses(15cm, 25cm) and soil mixing ratios(SL, P7P1L2, P6P2L2, P5P3L2, P4P4L2). The plant height, green coverage ratio, fresh weight, dry weight and chlorophyll contents of Z. japonica were investigated. For the soil thickness of 15cm, the plant height of Z. japonica was significantly as affected by the soil mixing ratio and it was shown in the order SL= P4P4L2 < P7P1L2 = P5P3L2 < P6P2L2. For the soil thickness of 25cm, the plant height was increased in order to SL < P7P1L2, P6P2L2, P5P3L2 < P4P4L2. The green coverage ratio was not observed by soil the mixing ratio or soil thickness. However, the green coverage ratio was 86~90% with a good coverage rate overall. The chlorophyll contents of Z. japonica were not significantly affected by the soil mixing ratio in the soil thickness of 15cm, but were higher in the natural soil than in the artificial soil at 25cm soil thickness. The fresh weight and dry weight of Zoysia japonica were heavier in the 25cm thickness than in the 15cm thickness and in the artificial soil mixture than in the natural soil. The result indicated that the growth of Zoysia japonica was more effective in the 25cm soil thickness with artificial soil than in the 15cm soil thickness with natural soil in the green roof system under rainfed condition.