• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.389-392
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• 2003

Coalfields in Korea have been grouped into thirteen based on mainly geographycal and geological structure, ten out of which have been developed. To classify the phisico-chemical characteristics of mine drainage from each coalfield and, if possible, to clarify the intrinsic reasons of them. Sampling of waters from 59 mines in eight coalfields has been carried out. Higher pH of drainage water from the mines of the Cungchung coalfield belong to the Beading system, Mesozoic era than those belong to the Pyungan system, Proterozoic era is due to the low content of sulfides of neighboring strata. The drainage from coal beds overlying limestone bed mostly show high pH. Waters from the Gangrung and Samchuck coalfields coal beds are located within black shale formation which contains a lot of sulfides showed mostly very high metal and S $O_{4}$$^{2-}$ concentrations.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제39권
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• pp.14.1-14.4
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• 2017

Tissue defect reconstruction using radial forearm free flap (RFFF) is a common surgical technique whose success or failure is mainly dependent on venous drainage. RFFF has two major venous outflow systems, superficial and deep vein. Drainage methods include combining both systems or using one alone. This review aims to recapitulate the vascular anatomy and network of RFFF as well as shed light on deep vein as a reliable venous drainage system. We also discuss basic evidence for and advantages of single microanastomosis with coalesced vein to overcome technical difficulties associated with the deep vein system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1364-1366
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• 2004

When an underground pipeline runs parallel with DC-powered railways, it suffers from electrolytic corrosion caused by the stray current leaked from the railway negative returns. Perforation due to the electrolytic corrosion may bring about large-scale accidents even cathodically protected systems. Traditionally, bonding methods such as direct drainage, polarized drainage and forced drainage have been used in order to mitigate the damage on pipelines. In particular, the forced drainage method is widely adopted in Seoul. In this paper, we report the analysis of the stray current conditions in Seoul subway DC electrification system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.373-375
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• 2003

The subway, a typical electrified transit, is operated by the 1500 V DC-powered system with the overhead positive feeder and the rails negative return. This return path would bring about considerable stray current circuits, that is, from the bottom of rails to sell and then to the station ground, unless the rail-to-soil resistance is sufficiently high. The stray current can cause electrolytic corrosion of subway metallic structures and adjacent underground utilities. In this paper, we reports on-site investigation of the stray current condition, especially influenced by drainage method. The drainage method including both forced drainage and polarized drainage, extensively adopted as a countermeasure for electrolytic corrosion of underground pipelines, was found out to exert a harmful influence upon rail components as well as the pipelines.

• 한국수자원학회논문집
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• 제52권4호
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• pp.301-312
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• 2019

기후 변화로 인한 국지성 호우의 증가로 도시의 내수침수피해가 증가함에 따라 이중배수체계 모형의 중요성이 증가하였다. 이중배수체계 모형은 지표면의 흐름과 관거의 흐름의 현상을 보다 정확히 표현하기 위하여 표면유출과 관거 유출을 각각의 관련 방정식과 매개변수들을 통해 해석하며, 이를 시각별로 연동하여 동시에 시뮬레이션하는 모형으로 이중배수체계 모형의 침수해석 결과는 도시계획 및 침수예방을 위한 계획 수립시 중요한 자료로 사용되고 있다. 본 연구에서는 자연유역과 도시유역이 혼재되어 있는 복합유역에 이중배수체계를 접목하여 해석이 가능한 COBRA 모형을 실제 유역에 적용하여 그 적용성을 파악해 보고 다른 이중배수체계 모형인 XP-SWMM, UFAM과 비교하여 결과의 적합성을 판단해 보았다. 동일한 대상유역에 대해 3가지 형태의 이중배수체계 모형의 침수해석 결과 및 침수양상을 분석한 결과를 종합해볼 때 우수관망의 용량 부족으로 발생하는 내수침수 특징은 XP-SWMM이 비교적 잘 모의하는 것으로 보였으며, UFAM은 도로의 빗물받이를 고려하는 특징에 따라 타 모형에 비해 가장 낮은 침수해석 결과를 나타내었다. 마지막으로 COBRA는 침수면적과 침수면적의 비율, 최대침수심이 강우량 증가에 비례하는 일반적인 결과와 토양조건에 따라 유효우량을 세밀하게 분류하여 모의하는 모형 특성 및 지표 저류에 의한 침수양상이 나타나는 현실성을 고려할 때 모형의 안정성 측면에서 양호하다고 판단되었다.

• 한국터널지하공간학회 논문집
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• 제19권3호
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• pp.533-549
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• 2017

본 연구에서는 지하 콘크리트 구조물 내로 누수된 지하수를 유도하여 배수하는 유도배수공법을 제시하였다. 유도배수공법은 유도배수판, 철망, 고정핀, 광물질 혼입 모르타르로 구성된다. 시공성 향상을 위하여 유도배수판 및 철망은 공압타카와 고정핀를 사용하여 콘크리트 표면에 부착하였다. 고로슬래그미분말을 30% 혼입한 모르타르는 뿜어 붙임 모르타르 장비를 사용하여 유도배수판 및 철망 표면에 타설하였다. 유도배수공법의 현장 시공성 및 성능 검증을 위하여 재래식 콘크리트라이닝 터널과 콘크리트 옹벽에서 시험시공을 수행하였다. 시험시공 완료 3년 후 유도배수공법은 성능저하의 문제점이 없는 것으로 판단되었다. 재령 14일과 3년에 뿜어 붙임 모르타르의 부착력 실험을 수행하였다. 유도배수판 표면에 철망을 적용한 경우 뿜어 붙인 모르타르의 부착력은 재령 14일에 1.04 MPa, 재령 3년에 1.46 MPa로 측정되었다. 철망을 적용하지 않은 경우의 부착력은 재령 14일에 1.13 MPa로 측정되었지만, 재령 3년에는 0.89 MPa로 기준 부착력 1 MPa보다 낮게 측정되었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권4호
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• pp.10-21
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• 2022

In the South Korea, 47% of abandoned mines are suffering from the mining hazards such as the mine drainage (MD), the mine tailings and the waste rocks. Among them the mine drainage which has a low pH and the high concentration of heavy metals can directly contaminate rivers or soil and cause serious damages to human health. The natural/artificial treatment facilities by using neutralizers and coagulants for the mine drainage have been operated in domestic and most of heavy metals in mind drainage are precipitated and removed in the form of metal hydroxide, alumino-silicate or carbonate, generating a large amount of mine drainage treated sludge ('MDS' hereafter) by-product. The MDS has a large surface area and many functional groups, showing high efficiency on the fixation of heavy metals. The purpose of this study is to develop a ingenious heavy metal stabilizer that can effectively stabilize arsenic (As) and heavy metals in soil by recycling the MDS (two types of MDS: the acid mine drainage treated sludge (MMDS) and the coal mine drainage treated sludge (CMDS)). Various analyses, toxicity evaluations, and leaching reduction batch experiments were performed to identify the characteristics of MDS as the stabilizer for soils contaminated with As and heavy metals. As a result of batch experiments, the Pb stabilization efficiency of both of MDSs for soil A was higher than 90% and their Zn stabilization efficiencies were higher than 70%. In the case of soil B and C, which were contaminated with As, their As stabilization efficiencies were higher than 80%. Experimental results suggested that both of MDSs could be successfully applied for the As and heavy metal contaminated soil as the soil stabilizer, because of their low unit price and high stabilization efficiency for As and hevry metals.

• 수산해양교육연구
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• 제28권6호
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• pp.1739-1750
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• 2016

This paper proposed a process for estimating the required capacity of emergency drainage system on a ship when the ship encounters a flooding accident. The process was established by selecting target vessel, making a scenario of flooding accident, considering static behavior of flooding water and the effect of ship motion due to ocean condition. In order to obtain the object of the research, MATLAB codes were developed for analyzing of static behavior of flooding water. Additionally, Ansys AQWA-NAUT was used to analyze the motion of the ship under an ocean condition and then the effect of ship motion was considered when the static behavior of flooding water was studied. The research exploited a trawler as a target vessel, and estimate the necessary capacity of the trawler's emergency drainage system by simulating a flooding water in the vessel.

• 상하수도학회지
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• 제36권5호
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• pp.289-296
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• 2022

Mangyeong River and Dongjin River are highly dependent on external regions for domestic and agricultural water, and the agricultural water supply and use system of those rivers are very complicated. For smooth water supply, rivers are used as a supply system. Of the total river water use permits (as of 2019), agricultural water accounts for 97.5%, 80.4% in Mangyeong River and Dongjin River, respectively. The excessive intake of river water as agricultural purpose is causing the stream to dry out and to deteriorate the ecological health of the river. It is necessary to minimize the water use system that takes in and utilizes river water. In both rivers, the flow rate of agricultural drainage and the load of major water quality items that flowing into the main stream are similar to or higher than those of the major tributaries, indicating that management is necessary to improve the water quality of the river. It is necessary to understand the effect of agricultural drainage on river water quality by establishing a continuous monitoring system for the form of agricultural drainage.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.449-452
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• 2008

Originally developed in Scandinavia over 40 years ago, syphonic roof drainage systems have been in use in the UK since the early 1990's. Since then, many large projects have used the syphonic system to overcome installation problems which would have been difficult to solve using a traditional gravity rainwater system.