• Title/Summary/Keyword: Saltwater

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Behavior Characteristics of Density Currents Due to Salinity Differences in a 2-D Water Tank

  • Lee, Woo-Dong;Mizutani, Norimi;Hur, Dong-Soo
    • Journal of Ocean Engineering and Technology
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    • v.32 no.4
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    • pp.261-271
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    • 2018
  • In this study, a hydraulic model test, to which Particle Image Velocimetry (PIV) system applied, was used to determine the hydrodynamic characteristics of the advection-diffusion of saltwater according to bottom conditions (impermeable/permeability, diameter, and inclination) and the difference of the initial salt. Considering quantitative and qualitative results from the experiment, the characteristics of the density current were discussed. As an experimental result, the advection-diffusion mechanism of salinity was examined by the shape of saltwater wedge and the flow structure of density currents with various bottom conditions. The vertical salt concentration obtained from the experiment was used as quantitative data to calculate the diffusion coefficient that was used in the numerical model of the advection-diffusion of saltwater.

Dynamic Shear Behaviors on the Normally Consolidation Clay-Geosynthetic Interface (토목섬유-정규압밀점토의 접촉면 동적 전단거동 평가)

  • Bae, Hyogon;Jang, Dongin;Kwak, Changwon;Park, Innjoon
    • Journal of the Korean GEO-environmental Society
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    • v.19 no.12
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    • pp.33-39
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    • 2018
  • In this study, important characteristics were identified for the Geosynthetic-soil interface using overburden pressure and saltwater and fresh water to evaluate silt shear behavior of the Geosynthetic-soil interface. In addition, waste landfill can secure spaces for waste disposal in the sea and this spaces can be used for additional facilities which will be necessary in the future. Analysis of behavior characteristics on interface of Geosynthetic-soil shows that, if analyzed using standard consolidometers, the consolidation stress of fresh water increased significantly more than saltwater. When analyzed using cyclic shear apparatus, saltwater and freshwater in both conditions, the displacement value increases as the wire gauges become closer to the lower module, and the shear fracture tends to occur radically under saltwater conditions than fresh water. Therefore, seawater, fresh water that act on the interface of geosynthetic-soil, and installation of facility using geosynthetic should be considered as important parameters that are essential for the dynamic design factor of the water controlling facility.

Evaluation of Electrical Conductivity Reduction of CDI and RO for Salt Removal in Developing Countries (개발도상국 염분 제거를 위한 CDI와 RO의 전기전도도 감소 성능평가)

  • Kim, Beomgyu;Yang, Dongjin
    • Journal of Appropriate Technology
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    • v.6 no.2
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    • pp.183-189
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    • 2020
  • Developing countries are areas where many problems arise from poor drinking water infrastructure. Developing countries often use groundwater as their primary source of drinking water, which causes problems. Among them, coastal areas are easily exposed to saltwater intrusion due to their geographical characteristics. Groundwater in areas exposed to saltwater intrusion has higher salinity than usual. If you continue to consume high salinity groundwater can cause a variety of fatal effects on the human body. Therefore, various alternatives have been proposed. This study explores the applicability of CDI(Capacitive Deionization) and RO(Reverse Osmosis) for water purification systems in areas where saltwater intrusion has occurred. Therefore, we will evaluate this by conducting water purification experiment. On the other hand, the supply of electricity is also important in the operation of water purification facilities. However, in many areas of developing countries, electricity is often not available. Therefore, this study intends to calculate the power consumption required for the actual use of the filter and to include it in the evaluation.

Seawater Intrusion due to Ground Water Developments in Eastern and Central Cheju Watersheds (중-동 제주 수역의 지하수 개발로 인한 해수침투)

  • 박남식;이용두
    • Journal of the Korean Society of Groundwater Environment
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    • v.4 no.1
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    • pp.5-13
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    • 1997
  • The Island of Cheju plans massive ground water development to meet predicted water demand. Effective management of ground water resources requires impact assessment study. Due to the nature of the island, effects of sea water must be considered. In this work, salt water intrusion, due to hypothetical ground water development in Eastern and Central Cheju Watersheds, is predicted using a sharp-interface model. The model considers simultaneously hydrodynamics of both freshwater and saltwater. The hypothetical ground water development was designed such that it follows closely the regional ground water development plan. The numerical model predicted that the saltwater wedge may intude over 1km depending on the location. This observation leaves doubt on impact assement studies based on freshwater-flow only modeling.

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Analysis Saltwater Intrusion using 2-D & 3-D Numerical Model in Seomjin River Estuary (2차원 및 3차원 수치모형을 이용한 섬진강 하구부 염수침입 분석)

  • Jung, Sung-Tae;Noh, Joon-Woo;Hur, Young-Teck
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.785-790
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    • 2009
  • 섬진강 하구역에서 모래채취로 인한 지형변화와, 댐 및 취수장의 증가로 인한 유량감소로 인해 해수의 역류범위가 증가하여 참게나 재첩과 같은 경제성 어종이 감소하고, 염분으로 인한 농업용수사용 불가와 같은 염수피해가 늘어가고 있다. 따라서 본 연구에서는 2차원 수치모형인 RMA-2, 4와 3차원 수치모형인 EFDC를 각각 이용하여 밀물 시 염수가 전파되는 범위 및 염수농도를 모의하고, 동시에 2차원 모형과 3차원 모형을 비교하여 모의목적에 대한 각 모형의 장 단점을 알아보았다. 모의결과를 살펴보면 최저 수위 시 두 모형이 큰 차이를 보이는 것을 볼 수 있었으며, EFDC가 상류쪽으로 더 길게 염수침입이 일어나는 것을 볼 수 있었다.

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Evaluation of Corrosion Protective System for Reinforced Concrete Structures Constructed With Sea Sand (해사 혼입된 콘크리트 구조물의 부식도 평가)

  • 김웅희;홍기섭;오승모;장지원;최응규;최완철
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.04a
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    • pp.203-209
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    • 1997
  • An experimental study to evaluate to evaluate corrosion protection systems was undertaken with 44 reinforced concrete slab specimens subjected to cyclic wet and dry saltwater exposure. Corrosion measurements included monitoring macrocell corrosion currents, which are genrerally accecpted in United States practice. Test results indicate that specimens containing 2 kg/$\textrm{m}^3$ of NaCl and exposed to wet(outdoor) and dry(indoor) conditions but not to saltwater show very low values of corrosion measurements regardless applying any corrosion protective systems. Corrosion currents of the specimens exposed at 10 percent of NaCl were higher than that of the specimen exposed at 5 percent of NaCl, so the density of the salt water had an influential effect on the test. For the specimens with water repellent membrane currents kept relatively low numerical values, but test specimens with surface corrosion inhibitor protective system showed high values of corrosion current. It would be expected that evaluation of the corrosion protective systems need long-term measurement.

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Analysis Saltwater Intrusion by Flushing Discharge in Seomjin River Estuary (섬진강 flushing 방류로 인한 하구부 염수침입 영향분석)

  • Noh, Jun-Woo;Lee, Jin-Young;Kang, Shin-Wook;Lee, Sang-Uk
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.982-985
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    • 2010
  • 섬진강 하구는 남해안 중부에 위치해 있으며, 하구둑이 건조되어 있지 않아 하구역 일대와 광양만이 하나의 넓은 기수역을 형성하고 있다. 또한 섬진강 하구는 상류에 섬진강댐, 주암댐 등이 건설되고 취수량이 증가하면서 하구로 유입되는 수량이 감소해 기수역이 상류로 확대된 것으로 보고되고 있다. 2008년 주암댐에서는 갈수기 때마다 대두되는 수질악화 및 염수침입을 방지하고자 3/10~3/24일에 걸쳐 1차, 4/23~5/7에 걸쳐 2차로 나누어 flushing 방류를 실시하였다. 이에 본 연구에서는 실측된 염분 자료를 토대로 3차원 수리 및 수질해석이 가능한 EFDC 모형을 활용하여 flushing 방류를 실시한 경우와 하지 않았을 경우에 대하여 모의를 수행함으로써 flushing 방류 유무에 따른 하구의 염수침입 및 염해피해 방지 효과에 대해 분석하였다.

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A Study for Physical Properties and Corrosion for Metals after Softening of Wood (포화염수 삶음 처리가 목재의 물리적 특성 및 금속 부식에 미치는 영향)

  • Park, Jin Young;Kim, Soo Chul
    • Journal of Conservation Science
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    • v.35 no.6
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    • pp.621-630
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    • 2019
  • A woodblock softening process using saltwater was investigated in order to reduce the cracks and distortion caused by the woodblock-making process and to make the woodblock softer and sculpturing easier. Although anatomical studies of woodblocks have been ongoing for years, little work has been done on softening treatments using natural materials. Hence, the purpose of this paper is to investigate the change in the physical properties of wood treated with saturated brine and the effect of salt on metal nails found embedded in woodblocks. After boiling for twelve h each in water and saturated brine, the saltwater-boiled specimens have longer drying times than the water-boiled specimens. Further, it was observed that salt particles penetrated the cells in the wood. As a result of exposing the copper and iron nails, which were stuck in each specimen, to a high humidity environment, the weight of the saltwater-boiled specimens increased due to the hygroscopicity of the salt. Corrosion of the nails also occurred. This result is similar to the problem that appears on the edge of a woodblock. In conclusion, it was shown that salt in the wood cells affects the corrosion of metal embedded in the wood.