• Water Engineering Research
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• 제2권2호
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• pp.103-112
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• 2001

Issues and problems in formulating South Korea's water resources policy are discussed in terms of water quantity and quality. South Korean needs both water conservation and water supply capability for the growing population and economic activities. The government has attempted to build more large-scale dams to store and supply water for residential, farming and industrial uses, but the environmentalists who emphasize conservation and environmental protection oppose the government. The environmentalists are popular among the general public. Water quality has been deteriorating from point- ad non-point sources. urban and farm runoffs are serious pollutants. All want by preserve water quality. There is no dispute on this matter between the government and the environmentalists. Money is hard to come by to preserve water quality. Economic and financial crises and no self-sufficient local governments' revenue structure are pessimistic. Basic survey on water resources, hydrology and hydraulic is badly needed for the future water resources planning.

• Korean Journal of Chemical Engineering
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• 제35권12호
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• pp.2336-2347
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• 2018

The azeotrope of methyl acetate methanol and water was isolated using extractive distillation with water as entrainer. The pressure-swing extractive distillation (PSED) process and vapor side-stream distillation column (VSDC) with the rectifier process were designed to separate the methyl acetate, methanol and water mixture. It was revealed that the VSDC with the rectifier process had a reduction in energy consumption than the PSED process. Four control schemes of the two process were investigated: Double temperature control scheme (CS1), $Q_R/F$ feedforward control of reboiler duty scheme for PESD (CS2), $Q_R/F$ feedback control scheme for VSDC (CS3), the feedback control scheme of sensitive plate temperature of side-drawing distillation column to dominate the compressor shaft speed (CS4). Feed flow and composition disturbance were used to evaluate the dynamic performance. As a result, CS4 is a preferable choice for separation of methyl acetate-methanol-water mixture. A control scheme combining the operating parameters of dynamic equipment with the control indicators of static equipment was proposed in this paper. It means using the sensitive plate temperature of side-drawing column to control the compressor shaft speed. This is a new control scheme for extractive distillation.

• 보존과학회지
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• 제25권2호
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• pp.171-178
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• 2009

유구 이전의 안정성은 현재 개발되어 사용되고 있는 반수용성 우레탄 1 차 전사체와 2 차 최종 에폭시 생성물의 우수한 물성으로 볼 때, 박리제의 물성과 박리성에 의해 좌우된다. 본 연구에서는 계면활성제를 사용하지 않은 세 가지 형태의 자기분산형 박리제를 합성하여 이들이 나타내는 박리성과 물성, 박리 후의 상태에 대하여 연구하고자 하였다. 이 수용성 자기 분산형 에폭시의 그 간의 박리제에서 문제시 되었던 지속 기간을 5 시간에서 60 일 이상으로 개선하였으며, 30% 수용화 이상에서 안정한 박리성을 보이고 있고, 건조 전후의 표면 색도의 변화도 없었다. 계면활성화제를 사용한 박리제와 비슷한 결과로 박리압을 나타내어 15~50 kg/$cm^2$을 나타내고 있으며, 저점도의 폴리머 사용 시, 고형분의 함량을 높이더라도 백화 현상이 발생하지 않아 저점도형 박리제로 사용이 가능한 것으로 보인다.

• 박물관보존과학
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• 제12권
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• pp.89-92
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• 2011

목제, 칠기, 초본류 등 출토 유기물은 매장환경에서 수분을 함유한 수침상태로 발굴된다. 이러한 유물은 수침상태 그대로 보관하지 않는 경우 수분이 장기간 서서히 증발되어 건조상태가 된다. 수침칠기 목질부는 부후되어 외형의 칠만 남았고, 초본류는 토양에 고착된 상태가 대부분이다. 본 처리에서는 철기시대 유물인 창원 다호리 출토 칠기와 초본류를 밀납, 레이온지를 사용하여 배접기법을 응용한 보존처리하였다. 그 결과 토양이 고착된 유기물에서 토양을 제거하고 칠과 초본류만을 보존처리하는 것이 가능하였다.

• 보존과학회지
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• 제29권1호
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• pp.25-33
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• 2013

전통 단청 교착제인 젤라틴(아교)의 물성에 따른 단청 도막의 성능을 평가하고자 직접 추출하거나 시판되는 아교 및 젤라틴 5종을 선정하고 수분반응성과 촉진내후성을 실험하였다. 실험결과, 겔 강도가 높은 1종의 젤라틴 단청 도막에서는 아교 대체 재료인 아크릴산 에스테르 수지 도막보다 수분 흡수율이 높고 촉진 내후성 시험 후에도 밀착성이 높았을 뿐만 아니라 젤라틴 도막보다 내수성이 우수하였다.

• 한국습지학회지
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• 제5권1호
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• pp.1-13
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• 2003

Conservation of wetlands are important because wetlands are hatcheries for fishes and habitat for migratory birds and mammals. Wetlands also function as a filter for polluted water and material and transition zone for harboring numerous species of plants and animals. This paper reviewed the importance of wetland conservation and policy on management of wetlands in Korea. Wetland Conservation Act(1999) and Maritime Management Act(1999) are two legislation for conservation of wetlands. Wetland Conservation Act is issued by both Ministry of Environment and Ministry of Maritime Affairs and Fisheries. The definition of wetlands are so diverse, but this paper categorized wetlands as both natural and man-made lakes, mud flat areas and inland wetlands. Management application was considered for each wetland categories.

• 충청수학회지
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• 제25권3호
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• pp.563-577
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• 2012

This paper presents a moving mesh method for solving the hyperbolic conservation laws. Moving mesh method consists of two independent parts: PDE evolution and mesh- redistribution. We compute numerical solution of shallow water equation by using moving mesh methods. In comparison with computations on a fixed grid, the moving mesh method appears more accurate resolution of discontinuities.

• 한국농공학회지
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• 제42권
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• pp.50-60
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• 2000

In this presentation I would like to introduce the Rural Sewerage Project, subsidized by the Ministry of Agriculture, Forestry and Fisheries (MAFF), for the purpose of water quality conservation and improvement of life in rural areas of Japan. Specifically, it will cover background information on the inauguration of the Project, its strong points, wastewater technology and some of its problems, system of the Project, etc.

• 한국환경복원기술학회지
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• 제9권3호
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• pp.26-38
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• 2006

For both a healthy environment and sustainable development, we frame a habitat assessment method, concerning biodiversity and physical characteristics. With the method, we set up and extract conservation areas from Peace Valley Resort Development Areas which can function as habitats. Absolute and relative assessment items which are the size of area, habitation of species with conservation value, distribution of communities, functions of habitats, ratio of non-native plants, connectivity of habitats, vegetation layers of forests and age of forests, and water systems are considered on newly extracted conservation areas, and the habitat value assessment was calculated on the items in a 3-point scale. By comparing and examining 3 existing proposals for extracted conservation areas, we assess existing proposals, make an alternative proposal, and try to verify the possibility of applicability to extracted conservation areas. Proposal A and C must not be adopted since almost all conservation areas would be developed in the proposals. Proposal B, consisting of 53% development areas and 47% non-development areas, does not have enough development areas, so high density building arrangements should be encouraged in order to preserve conservation areas. Therefore, proposal B would be the best in ecological terms among the 3 proposals, if 3 conditions are considered : 1) new extracted conservation areas should be conserved; 2) 10~15m wide green-zones on both sides of the water system, which can play a role as ecological corridors, should be considered in development areas; 3) building arrangement should not interrupt the ecological corridors.

• 보존과학연구
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• 통권32호
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• pp.99-112
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• 2011

함양 승안사지 삼층석탑은 중립 내지 세립질의 흑운모화강암과 화강편마암이 주를 이루고 있으며 부분적으로 거정질편마암, 백운모편마암, 반려암질암이 혼용되었다. 이 석탑은 주변의 수목 및 잔디에 의해 전면에 걸쳐 지의류와 선태류 등이 서식하고 있어 석탑 표면이 심하게 훼손되어 있다. 따라서 이 연구에서는 이 석탑에 대한 종합적인 풍화훼손도 진단과, 이를 근거로 보존처리를 수행하였다. 보존처리에서는 석탑의 전면에 걸쳐 자생하는 지의류 및 오염물 등에 대해 부드러운 솔과 나무칼을 사용하여 건식세정을 실시하였고 이때 고착지의류 등 잘 제거되지 않는 부분은 증류수를 이용한 습식세정으로 제거하였다. 또한 기존에 설치되어 있는 보호난간을 석탑과의 거리를 고려하여 적당한 높이로 재설치하였으며, 석탑 주변의 지반은 마사토로 정비하고 배수흐름을 원활하게 하기위해 자연구배를 두고 자연측구를 설치하였다.