• The Journal of Engineering Geology
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• v.8 no.2
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• pp.115-130
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• 1998

An analysis on landslide types and susceptibilities associated with geomorphic characteristics has been conducted with 916 landslide inventories in Yeonchon-Chulwon District, where two day's heavy rainfall was concentrated on July, 1996. The precipitation during the 2 days, which is equivalent to 0.372 of event cofficient, can cause large landslides based on Olivier's equation. Sliding materials are dominantly composed of debris mixed with rock fragments and soil derived from colluvium and residual soils. 66% of the landslides are belong to debris flow md 23% are due to sediments flow, in accordance with the classification of sliding materials. Most of landslides(> 90%) are small and shallow, less than l00m in length and about 1m in depth, and classified as transitional type. Granite is more susceptible as much as 4.7 times than metamorphic rocks and 2.7 times than volcanic rocks, probably due to higher weathering grade of granite. The highest landslide frequency is concentrated on the areas between 200 and 300m in height and on the slopes between $10-20^{\circ}$ in dgree. More than 50% of landslides occurred under these geomorphic conditions. Consequently, colluviums and residual soils distributed on the gentle slopes are most susceptible to the landslides of the area.

• Resources Recycling
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• v.15 no.4 s.72
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• pp.52-59
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• 2006

The purpose of this study was to evaluate the effects of ground granulated blast-furnace slag on strength development and durability of ordinary portland cement concrete (OPC) with steam curing types. Main experimental variables were slag contents(0%, 10%, 30%, 50%, 70%) and curing types (standard, accelerated curing). It were performed to check the basic properties of concretes that compressive strength, rapid chloride ion permeability and chemical resistance. From the result, we have found that increasing the amount of blast-furnace slag produced concrete with increased compressive strength and permeability resistance. Rapid freezing-thawing test showed that they were good enough to protect the concrete structures and to carry out cyclic freezing and thawing. The freeze-thaw resistance of blast-furnace slag produced concretes maintained above 90% of relative dynamic modulus after 300 freezing-thawing cycles. Increasing the amount of blast-furnace slag produced concretes with increased chemical resistance.

• Food Science and Preservation
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• v.13 no.2
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• pp.144-153
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• 2006

The effects on deacidification of citrus fruits produced at early harvesting season for juice products were examined by heating treatment of raw fruits and electrodialysis of juice. Weight and total acidities were decreased by heating treatment for 40 hr at $25^{\circ}C,\;30^{\circ}C,\;35^{\circ}C\;and\;40^{\circ}C$, but $^{\circ}Brix$ and pH increased Sugar to acid ratio also increased. Total acidities were decreased from 1.25 (Oct30, 2004), 1.24 (Nov.5, 2004), 0.99 (Nov.13, 2004) and 0.98% (Nov.19, 2004) to 0.48 (Oct30, 2004), 0.51 (Nov.05, 2004), 0.37 (Nov.13, 2004) and 0.42% (Nov.19, 2004) by electrodialysis for 100 min respectively, and $^{\circ}Brix$ also slightly decreased, but solid to acid ratio was increased as a result. However pH and color remained almost unchanged by electodialysis. Also, free sugar contents of citrus juice little were changed, but organic acid content were decreased fairly. Narirutin and hesperidin content among flavonoids were slightly decreased by electrodialysis, but they were not significantly different. $K^+,\;PO_4^{2-},\;SO_4^{2-}\;and\;Cl^-$ content were decreased by electrodialysis, and $K^+$ contents decreased by more than 80% However, $Na^+$ consent was increased by about 2 times. Total polyphenol contents and electron donating abilities were decreased a little by electrodialysis but nitrite scavenging abilities were little changed. By acceptability test citrus juice prepared by electrodialysis for 100 min was superior to original citrus juice.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.599-604
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• 2005

최근 일부 댐유역에서 게릴라성 집중호우와 태풍 등과 같은 특이 호우에 대하여 강우-유출분석을 실시한 결과 유출율이 $100\%$를 상회하는 경우가 발생함에 따라 효율적이고 안전한 치수 및 방재업무를 실시하는데 많은 어려움을 겪고 있다. 본 연구에서 일부 댐유역의 유출율이 $100\%$를 상회하는 원인으로 강우 관측자료의 신뢰성이 결여되어 나타나는 것으로 보았으며, 만일, 강우관측소에서 계측된 강우자료의 신뢰성이 결여 되어 있다면, 이로 인한 유역 강우의 추정오차는 제거될 수 없을 것이다. 일반적으로 강우관측소에서 발생하는 계측오차는 관측소의 고도, 지형적인 장애(산악영향, 지장물 등) 및 기상학적인 장애(기단의 이동방향, 호우의 발생원인, 돌풍 등) 등 외부적인 요인으로 인해 발생할 수 있다. 따라서, 본 연구에서는 강우관측소에서 발생하는 계측오차의 다른 여러 외부적 요인들 중 가장 큰 요인으로 돌풍과 같은 풍속에 의해 발생하는 것으로 판단하였고, 연구대상 유역인 임하댐 유역의 유출율과 치대 풍속간의 상관분석을 실시하였으며 분석결과 유출율은 최대 풍속에 커다란 영향을 받는 것으로 나타났다. 결국, 유출율이 $100\%$를 상회하는 호우에서 강우관측소의 강우는 강우시 돌풍과 같은 외부적인 요인으로 인해 적게 관측된 것으로 추정되며 저평가된 강우자료로부터 산정된 면적평균강우의 추정오차로 인해 유출율이 $100\%$를 상회하는 것으로 나타났다. 따라서 본 연구에서는 유출율과 풍속간의 관계로부터 강우보정계수 추정식을 산정하였으며, 추정된 보정계수를 이용하여 관측된 강우자료를 보정한 후 강우-유출분석을 실시한 결과 댐유입수문곡선을 보정전에 비해 보다 근사하게 모의하였다. 위해서는 대상유역에 적합한 선행 강우일수의 결정이 중요하리라 판단된다.인 분석을 수행하고, 배수갑문 개방에 의한 수질개선효과를 최대화하기 위한 환경관리 방안 제시에 중점을 두어 수행하였다.ncy), 환경성(environmental feasibility) 등을 정성적으로(qualitatively) 파악하여 실현가능한 대안을 선정하였다. 이렇게 선정된 대안들은 중유역별로 검토하여 효과가 있을 것으로 판단되는 대안들을 제시하는 예비타당성(Prefeasibility) 계획을 수립하였다. 이렇게 제시된 계획은 향후 과학적인 분석(세부평가방법)을 통해 대안을 평가하고 구체적인 타당성(feasibility) 계획을 수립하는데 토대가 될 것이다.{0.11R(mm)}(r^2=0.69)$로 나타났다. 이는 토양의 투수특성에 따라 강우량 증가에 비례하여 점증하는 침투수와 구분되는 현상이었다. 경사와 토양이 같은 조건에서 나지의 경우 역시 $Ro_{B10}(mm)=20.3e^{0.08R(mm)(r^2=0.84)$로 지수적으로 증가하는 경향을 나타내었다. 유거수량은 토성별로 양토를 1.0으로 기준할 때 사양토가 0.86으로 가장 작았고, 식양토 1.09, 식토 1.15로 평가되어 침투수에 비해 토성별 차이가 크게 나타났다. 이는 토성이 세립질일 수록 유거수의 저항이 작기 때문으로 생각된다. 경사에 따라서는 경사도가 증가할수록 증가하였으며 $10\% 경사일 때를 기준으로 $Ro(mm)=Ro_{10}{\times}0.797{\times}e^{-0.021s(\%)}$로 나타났다.천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다. 그러나 진단 즉시 직접 좌관상동맥-대동맥 이식술로 수술적 교정을 해줌으로

• The Journal of Engineering Geology
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• v.28 no.1
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• pp.69-79
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• 2018

The Korean government attempts to reduce $CO_2$ emissions by 37% to 314.7 Mt $CO_2$, down from the estimated 850.6 Mt $CO_2$ until 2030 in order to confront green house effect. In this context, in 2014, Korean government launched $CO_2$ Storage Environmental Management Research (K-COSEM) Center for carrying out pilot-scale research on $CO_2$ leakage from underground $CO_2$ storage facilities. For the detection of $CO_2$ leakage, it is necessary to identify hydrologeological and geophysical characteristics of the subject area. In the study site of Naesan-ri, Daeso-myeon, Eumseong-gun, Chungbuk Province, two times injection tests (June 28-July 24, 2017 and August 07-September 11, 2017) of $CO_2$ and $SF_6$ dissolved waters, respectively, was conducted to understand the leakage behavior of $CO_2$ from underground. The injection well was drilled to a depth of 24 m with a 21-m casing and screen interval of 21~24 m depth. Two times resistivity surveys on August 18, 2017 and September 1, 2017, were conducted for revealing the flow of the injected water as well as the electrical properties of the study site. The study results have shown that the high-resistivity zone and the low-resistivity zone are clearly contrasted with each other and the flow direction of the injected water is similar to natural groundwater flow. Besides, the low resistivity zone is widely formed from the depth of injection to the shallow topsoil, indicating that the weathered zone of high permeability has high $CO_2$ leakage potential.