• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.147-150
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• 2004

Firstly, the precipitation data have to be interpolated for the estimation of water resources. For this purpose, the correlative analysis is made between the topographic variables, which, influence the precipitation phenomena, are classified by elevation(ELEV), slope(SLOPE), distance to the sea(SEA), obstacle (OBST), barrier(BAR), and roughness index(SHIELD), using TOVA(Topographic Variables Extraction Program) and events precipitation during the periods from january the 1st 2000 to December 31 2002. The coefficients of determination show that each event has different topographic influence and ELEV, SLOPE and OBST to the South-West, and SHIELD of every direction have close relationship with the precipitation. The multiple regression model explains 96% of the spatial variation of precipitation.

• Economic and Environmental Geology
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• v.33 no.5
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• pp.435-442
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• 2000

Although the mummies of Lee Myeong-Jung and his wife who were a member of the Moon family, were buried in similar sites in around 1560, the degree of decay of the dead bodies and antiquities between two people were quite different. This study was focused on the cause of-those differences in terms of engineering geology. Cranular soil found several metered depth around the study site has good drainage ability and such characteristic could be a factor of excellent conservation of dead body. From the physical characteristics of the lime-containing material that is considered to be a barrier from water and air, it was observed that the material around dead body of wife was more compact and denser than that of husband. Such results could be a clear evidence that the lime containing material around dead body of wife was excellent barrier for keeping away from water and air. To investigate those differences of physical characteristics and constituent materials between two lime-containing materials, minerals had to be identified from the two materials. It was revealed that lime-containing material around dead body of wife contains gypsum and more calcite, which could be the reason for better barrier preventing from water and air than those around husband.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.1
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• pp.23-34
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• 2004

To validate the previous conceptual design of cover system, construction of the engineered barrier test facility is completed and the performance tests of the disposal cover system are conducted. The disposal test facility is composed of the multi-purpose working space, the six test cells and the disposal information space for the PR center. The dedicated detection system measures the water content, the temperature, the matric potential of each cover layer and the accumulated water volume of lateral drainage. Short-term experiments on the disposal cover layer using the artificial rainfall system are implemented. The sand drainage layer shows the satisfactory performance as intended in the design stage. The artificial rainfall does not affect the temperature of cover layers. It is investigated that high water infiltration of the artificial rainfall changes the matric potential in each cover layer. This facility is expected to increase the public information about the national radioactive waste disposal program and the effort for the safety of the planned disposal facility.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.276-282
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• 2003

The geoscientific study on geological disposal for radioactive wastes has established the stepwise site characterization program, methods and investigation technology. However the intrinsic properties of geological material such as heterogeneity and scale dependent properties make difficulty on satisfactory understanding of geological conditions. To avoid unnecessary time delay and unexpected extra-cost for site investigation, the accurate and complete site investigation program should be established in a stepwise manner and the QC programs for investigation methods and procedures. Moreover, the technical requirements and preferences for a repository should be distinguished and be assessed at the end of each investigation step.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.315-321
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• 2003

In this study, analysis of the disposal tunnel spacing and disposal pit pitch was carried out, as a factor of the design to estimate the scale and layout of the repository To do this, based on the reference repository concept and the engineered barrier concept, the cross section of the disposal tunnel and disposal pit are established and the mechanical and thermal stabilities of the tunnels are analyzed. Also, the optimized disposal tunnel spacing and the disposal pit pitch which minimize the excavation volume was proposed. The detailed analyses by the exact site characteristics data are needed to reduce the uncertainty of the site in the future.

• Journal of computational fluids engineering
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• v.14 no.2
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• pp.9-18
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• 2009

The cargo containment system (CCS) for ships carrying cryogenic fluid consists of at least two levels of barriers and insulation layers. It is because, even though there is a small amount of leak through the primary barrier, the liquid tight secondary barrier blocks further leakage of the cryogenic fluid. However, once the secondary barrier is damaged, it is highly possible that the leaked cryogenic fluid flows through the flat joint made of glass wool and reaches the inner hull of the ship. The primary objective of the present study is to investigate the influence of the damage extent in the secondary barrier on the amount of leaked cryogenic fluid reaching the inner hull and the temperature distribution there. Simulation results using a computational fluid dynamics tool were compared with the experimental data for the leaked cryogenic fluid flow and evaporation in the secondary insulation layer. The experimental and computational results suggest that, unless there is a massive leak, the cryogenic fluid mostly evaporates in the insulation layer and does not reach the inner hull in the state of liquid.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.3
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• pp.173-179
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• 2010

In a HLW repository, the buffer is exposed to an elevated temperature due to a radioactive decay and geochemical conditions for a long time and such a hydrothermal condition may cause a significant loss of its barrier function. This study carried out hydrothermal tests with a domestic smectite clay to investigate the changes in the expandibility, layer charge, and cation exchange capacity of the smectite. When the temperature and potassium concentration in solution was increased for the hydrothermal treatments, the expandibility decreased, the layer charge negatively increased, and the CEC also decreased.

• Journal of Soil and Groundwater Environment
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• v.9 no.3
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• pp.56-61
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• 2004

The topographic variables, which influence the precipitation phenomena, are classified by elevation (ELEV), slope (SLOPE), distance to sea (SEA), obstruction (OBST), barrier (BAR), roughness (SHIELD), extracted and analysed according to resolutions. This study is performed through 100 m, 200 m, 400 m, 600 m, 800 m and 1,000 m based on 50 m DTM using TOVA (Topographic Variables Extraction Program). The result of a case study on Jeju weather station says that the variance according to resolution is generally less than that according to cardinal direction, but particularly SHIELD values and some cases for 600m resolution have a significant results.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.68.1-68.1
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• 2010

염료감응형 태양전지에서 가능한 광전자의 이동경로에 대해 살펴보면 빛 에너지를 흡수한 루테늄계 염료는 기저상태에서 여기상태로 전이한 후 광전자의 반도체 전도띠로 전자주입이 이루어진다. 이러한 전자 중 일부는 반도체산화물의 트랩으로의 전이와 트랩에서 염료 기저상태로의 전이가 일어나고 일부 전자는 전해질의 이온종 또는 산화된 염료와 재결합하는 현상이 일어난다. 본 연구에서는 이러한 전자의 재결합을 막고자 p형 반도체인 NiO paste를 제작하여 $TiO_2$ 광전극 층 위에 코팅하였다. 코팅된 NiO 층은 홀수용체로서 염료에 전자를 제공해 주는 역할과 동시에 $TiO_2$ 가전도대로 이동되었던 전자들이 염료의 기저상태의 홀이나 전해질로의 전자 유입이 이루어지는 전자의 재결합을 막는 방벽의 역할을 동시에 하게 된다. 제작된 염료감응형 태양전지 셀의 에너지 변환효율 특성을 알아보기 위하여 1000 W Xe Arc Lamp와 Air Mass 1.5, filter가 장착된 Thermo-Preal (USA) Solar simulator system을 사용하여 개방전압 (Voc), 광전류 (Isc), fill factor (FF), 에너지변환 효율 (${\eta}$)을 조사하였으며 광학현미경을 통해 염료의 흡착 정도를 비교해 보았다. NiO의 코팅 두께나 NiO 나노입자 크기에 따라 염료감응형태양전지에서 에너지변환효율에 미치는 영향을 조사하였다. NiO가 코팅되지 않은 $TiO_2$ 광전극과 비교해 볼 때 NiO 코팅시 Voc와 Isc의 증가로 인해 에너지변환효율이 20% 이상 향상되는 것을 볼 수 있었다.

• Journal of the Korean Institute of Gas
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• v.17 no.1
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• pp.56-66
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• 2013

The gas production plants supply the inert gas to production plants for maintaining safe operation and also supply combustible, flammable, explosive and toxic gases as functions of basic materials needed for producing chemical goods. In addition, gas plants need to be safe and reliable operation because they are operated under high temperature, high pressure, cryogenic and catalytic reactions. As these plants have a complex process in operation, there has been a risk that major industrial accidents such as a fire, explosion and toxic gas released, also risks of asphyxiations by inert gases and burns caused by high temperature and cryogenic substances. This study is to carry out the semi quantitative risk assesment method which is the generic risk analysis (GRA). This method is applied to air separation unit(ASU) to identify its initial risk, safety barriers, residual risk and elements important for safety(EIS). The result of this study, suggested the management tools and procedures of implementation for EIS management.