• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.1192-1201
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• 2009

The ground work with of the research is constructed by a SCP method to improve clay ground in the sedimentary layer and sand ground in the reclamation layer at the same time as a reclaimed soft ground by reclaiming deep depth. Improved fine-grained soils in the sand ground decrease the ground improvement effect and have an influence on replacement ratio of SCP method. Fine-Grained soils which advances in sand ground reduces a from improvement effect, Makes affect in replacement ratio of SCP method. In this study, consideration about replacement ratio of sand ground, Tried to observe affects in replacement ratio of fine-grained soils SCP method of dredging reclamation ground. The result, replacement ratio which follows in the Japan Geotechnical Society experience-chart(1988) recording where fine-grained soils content will increase feebly, was visible the aspect which increases progressively, replacement ratio in compliance with Gibbs and Holts(1973) methods according to fine-grained soils increase is visible the tendency which decreases gradually with the enemy. Specially, according to case fine-grained content of Mizuno(1987) methods increases, replacement ratio suddenly was showing the trend which rises from of 50% and according to fine-grained soils increase was overestimated.

• 한국환경복원기술학회지
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• 제5권3호
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• pp.1-8
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• 2002

Clayey paddy soils should be mixed with other good coarse soils to be used as a material for the lining, or, embankment. However, it has been difficult to separate soil particles from each other because of the internal cohesion in the soil gradation(separation) characteristics of the fine soil were investigated by various laboratory tests including the slaking durability test. Degradation rate of the soil were dependent upon the clay content and the initial water content before the submergence. The amount of degradations decreased as initial water content increased with exponential functions. The dried specimens separated into the particles after 24 hours of the submergence and specimens which water contents were less than 10% also separated into the particles after 2, or 3 days of the submergence. Compaction curves and the unconfined strength were not varied before and after the submergence. However, unconfined strength decreased as water content increased.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.73-76
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• 2005

This study aims to suggest a simple and convenient design for a mix proportion method for high performance concrete by determining the optimum fine aggregate ratio and minimum binder content based on the maximum density theory. The mix design method introduced in this study adopted the optimum fine aggregate ratio with a minimum void and binder content higher than the minimum binder content level. The research results reveal that the method helps to reduce trial and error in the mixing process and is a convenient way of producing high performance concrete with self filler ability. In an experiment based on the mix proportion method, when aggregate with the fine aggregation ratio of 41$\%$ was used, the minimum binder content of high performance concrete was 470kg/$m^{3}$ and maximum aggregate capacity was $0.657m^{3}/m^{3}$. In addition, in mixing high performance concrete, the optimal slump flow to meet filler ability was 65$\pm$5cm, V load flow speed ranged from 0.5 to 1.5.

• 한국지반신소재학회논문집
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• 제15권2호
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• pp.25-33
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• 2016

본 연구는 낙동강 하구 델타 지역의 상부퇴적사질토에 대한 기초적인 연구로 퇴적사질토의 물리적 특성과 세립분 함유율 및 상대밀도에 따른 전단강도와 투수특성에 대해 알아보았다. 전답토층 및 하부연약점토층과 인접한 구간에서 퇴적사질토는 세립분 함유량이 높고, 그 외 구간(일부제외)에서는 5%내외의 세립분을 함유한 것으로 나타났다. 비중은 심도나 위치에 상관없이 거의 일정하고, 퇴적환경에 상관없이 0.1~0.4mm의 가는 모래가 주로 분포하고, 전 구간에서 일라이트 점토광물이 검출되었다. 재성형한 상부퇴적사질토 시료의 직접전단시험 결과 상대밀도가 증가할수록 내부마찰각 및 점착력은 증가하였다. 하지만 상대밀도의 증가에 따른 내부마찰각과 점착력의 증가는 그렇게 크지 않은 것으로 나타났다. 반면 세립분 함유율의 영향이 크게 나타났는데 모래에 세립분이 증가할수록 내부마찰각은 감소하고, 점착력은 선형적으로 증가하는 경향이 나타났다. 상부퇴적사질토의 투수계수는 상대밀도 및 세립분 함유율이 증가할수록 낮아지는데 15% 이상의 세립분이 함유된 모래의 경우 투수계수는 상대밀도의 영향을 받지 않는 것으로 나타났다.

• 한국관개배수논문집
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• 제13권2호
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• pp.246-253
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• 2006

Experimental laboratory tests were carried out to assess the effect of fine content and salinity of soils on the measurement of TDR(Time Domain Reflectometry). In the test, using soil columm which was made by PVC pipe with the dimension of 25cm height and 20cm diameter, the salinity variation of soil was controlled by the solution which was dissolved NaCl to destilled water in the range of 0-40g.$L^-1$. The fine content of soil was controlled by kaolinite which was mixed with Jumunjin sand in the range of 0-50% to the total dry weight. The water contents of soil tested were measured with the conventional oven dry method beside TDR and compared the these values to figure out the extent of effect. As the results of tests, it was appeared that the water content measurement by TDR can be affected by the salinity level, fine contents, and the degree of saturation of the soil.

• 보존과학회지
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• 제38권4호
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• pp.334-346
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• 2022

The manufacturing technique was studied through the structure and material characteristics of the walls and the painting layers of the Avalokitesvara Bodhisattva mural of Geungnakjeon Hall, Daewonsa Temple. The mural is painted and connected to the earthen wall and the Junggit, and the wall is composed of wooden laths as a frame, the first and middle layers, the finishing layer, and the painting layer. The first layer, middle layer, and finishing layer constituting the wall were made by mixing weathered soil and sand. It was confirmed that the first layer had a high content of loess below silt, and the finishing layer had a high content of fine-sand and very fine sand. For the painting layer, a ground layer was prepared using soil-based mineral pigments, and lead white, white clay, atacamite, minium, and cinnabar (or vermilion) pigments were used on top of it. The Avalokitesvara Bodhisattva mural was confirmed to belong to a category similar to the soil-made buddhist mural paintings of Joseon Dynasty. However, it shows characteristics such as a high content of fine sand in the finishing layer and overlapping over other colors. Such material and structural characteristics can constitute important information for future mural conservation status diagnoses and conservation treatment plans.

• 한국산학기술학회논문지
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• 제14권3호
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• pp.1481-1488
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• 2013

지속적인 경제성장에 따른 콘크리트 구조물의 급증으로 양질의 하천모래가 고갈됨에 따라 콘크리트용 대체 골재 개발이 필요한 실정이다. 따라서 이 연구의 목적은 낙동강 세사를 콘크리트용 대체골재로서 적극적으로 활용하기 위한 기초자료를 제시하는 것이다. 이를 위하여 세사 분포지역인 낙동강 본류의 중 하류에서 세사 시료를 채취한 후, 이들의 밀도, 입도, 단위용적질량 및 0.08mm체 통과량 등의 물성 평가와 세사를 사용한 콘크리트의 배합특성으로 설계기준강도에 대한 단위수량 및 단위시멘트량을 평가하였다. 그 결과, 세사를 사용한 콘크리트의 설계기준강도에 대한 단위수량 및 단위시멘트량은 입도가 좋은 기준모래를 사용한 콘크리트의 경우보다 크게 증가하지 않는 것으로 나타나, 전자와 후자 사이의 배합특성은 별 차이가 없는 것으로 나타났다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 춘계학술논문 발표대회 제6권1호
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• pp.85-88
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• 2006

This study investigated influence of fine aggregate types on fundamental properties of cement mortar. Test showed that concrete using lime stone crushed fine aggregate(L) exhibited the most favorable fluidity due to grain shape and particle distribution, and next was blending aggregate miting L and G, blending aggregate mixing L and N, granite crushed fine aggregate(G), natural fine aggregate(N) in an order. Concrete using N had the highest air content and L was the smallest value because of the effective filling performance by continuos particle distribution. Compressive, tensile and flexural strength of all concrete using L had the highest value due to the smallest value of air content. It is also found that concrete using L resulted in decrease of drying shrinkage length change ratio.

• 한국약용작물학회지
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• 제16권4호
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• pp.211-217
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• 2008

수삼을 주근 및 세근으로 분리하여 원적외선건조기를 이용하여 건조온도(70, 80, 90, 100, 110, 120, 130 및 $140^{\circ}C$)에 따라 건조한 후, 사포닌, 당, 유기산 및 색도를 분석하였다. 건조한 주근의 총사포닌 함량은 건조온도가 높을수록 미량 증가하여 $130^{\circ}C$에서 가장 높았고 세근에서는 온도가 증가할수록 감소하였다. 세근에서 온도가 증가할수록 급격하게 감소한 ginsenoside는 Re, Rc, Rb1 및 Rb2 이었고 Rg1, Rg3, Rf 및 Rb3는 미량씩 증가하였다. 가용성 당은 주근, 세근 모두 $70^{\circ}C$에서 가장 많이 용출되었고, 유기산 함량은 주근 세근 모두 $120^{\circ}C$에서 가장 많은 함량을 보였다. 건조온도에 따른 색도는 온도가 증가할수록 밝기는 주근 세근 모두 감소하였고 적색도는 온도가 증가할수록 높아져서 $120^{\circ}C$에서 가장 높았고 황색도는 $100^{\circ}C$에서 가장 높았으며 그 이상의 온도에서는 감소하는 경향이었다. 따라서 수삼 건조 시 건조온도에 따라 사포닌 구성함량 변화의 차이를 보임으로서 백삼의 이용목적에 맞게 수삼 건조 시 온도, 건조 형태 및 주근과 세근을 분리하여 건조하는 방법을 이용하는 것이 바람직할 것으로 생각된다.

• 환경위생공학
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• 제11권3호
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• pp.79-84
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• 1996

In order to determine the content of heavy metal in common salts, 35 bay salt samples, 7 refined salt samples, 7 fine salt samples, 5 bake salt samples and 5 bamboo bake salt samples were collected from old market in major cities. Heating bay salt 35 samples, it made heating bay salt of $500^{\circ}C$, /TEX>(34 samples), heating bay salt of $1000^{\circ}C$(35 samples). These were analysed for contents of lead(Pb), cadmium(Cd), iron(Fe) and zinc(Zn) by atomic absorption spectrophotometer. The results were as follows : Mean content of lead in bay salts was $0.124{\pm}0.035ppm$ refined salt was $0.130{\pm}0.019ppm$, fine salt was $0.073{\pm}0.036ppm$ bake salt was $0.097{\pm}0.023ppm$, bamboo bake salt was $0.117{\pm}0.020ppm$, heating bay salt was $0.063{\pm} 0.021ppm$ in $500^{\circ}C$, heating bay salt was $0.063{\pm}0.039ppm$ in $1000^{\circ}C$. And bay salt refined salt bamboo bake salt were not significant one another. Mean content of cadmium in bay salts was $0.031{\pm}0.008ppm$ refined salt was $0.032{\pm}0.003ppm$, fine salt was $0.037{\pm}0.005ppm$, bake salt was $0.169{\pm}0.117ppm$ bamboo bake salt was $0.079{\pm}0.052ppm$, heating bay salt of $500^{\circ}C$ was $0.030{\pm}0.029ppm$ heating bay salt of $1000^{\circ}C$ was $0.017{\pm}0.013ppm$. And bay salt refined salt, fine salt were not significant one another. Mean content of iron in bay salts was $1.025{\pm}0, 634ppm$, refined salt was $0.359{\pm}0.163ppm$ fine salt was $0.267{\pm}0.068ppm$, bake salt was $2.929{\pm}1.963ppm$, bamboo bake salt was $5.378{\pm}3.676ppm$, heating bay salt of $500^{\circ}C$ was $0.847{\pm}0.315ppm$ heating bay salt of $1000^{\circ}C$ was $0.991{\pm}0.868ppm$. And bay salt refined salt, fine salt, bake salt, bamboo bake salt were significant one another(p<0, 01). Mean content of zinc in bay salts was $0.253{\pm}0.154ppm$, refined salt was $0.263{\pm}0.091ppm$ fine salt was $0.187{\pm}0.015ppm$, bake salt was $0.166{\pm}0.034ppm$, bamboo bake salt was $0.282{\pm}0.064ppm$, heating bay salt of $500^{\circ}C$ was $0.253{\pm}0.085ppm$, heating bay salt of $1000^{\circ} C$ was $0.242{\pm}0.179ppm$. And bay salt refined salt fine salt, bake salt, bamboo bake salt were not significant one another.