• 한국작물학회지
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• 제43권1호
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• pp.38-43
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• 1998

This study examined root growth and distribution under the direct seeding of rice cultivars developed in Korea, Japan, and the U.S. Cultivars from the U.S., especially 'M202' and 'Caloro', had a high ratio of the dry matter partitioning for root and top plant components. Caloro had high root and top growth. 'Koshihikari' from Japan showed the lowest ratio of R/T (root/total dry matter) due to the small amount of root and top plant growth. Most Japanese cultivars except transplanted 'Hatsuboshi' showed low ratio of R/T. Patterns of root distribution for each soil block were recorded by the root box-pin board method. Roots of all cultivars were distributed in blocks A, C, and E in the middle of box, i.e., just below the plant base. Roots of 'Dongjin', M202, and Caloro were distributed deeper than the others. Roots of transplanted Hatsuboshi developed much better than direct seeded Hatsuboshi. Total root weight density was highest in Caloro followed by Dongjin, 'Gancheok', 'Calrose', and the others. The root density of Caloro was twice as much as those of the others except Dongjin. According to cumulative percentages of root distribution on each soil layer, roots of most cultivars were distributed below 20cm. The U.S. cultivars showed vertically well developed root systems as compared to others. A large amount of roots were distributed in the top 15cm of soil layer for Hatsuboshi and Koshinikari, and their root systems appeared to be shallow. In contrast, the rates of root distribution in the top 10cm of soil layer were low for Dongjin, Calrose, and Caloro. These cultivars had relatively deep root systems.

• 분석과학
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• 제22권4호
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• pp.293-301
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• 2009

휴대용 형광 분석기의 개발을 위한 사전 기초연구로서 bench-top ED-XRF 및 휴대용 XRF를 이용하여 토양 시료 중의 Cr, As, Se, Hg, Pb, Cd 등 6종의 유해금속 성분들을 비교 분석하였다. 유해금속 원소를 0~1500 mg/kg 농도 범위로 오염시킨 토양 인증표준물질을 구입하여 XRF 분석의 중요 인자인 X-선 튜브 전압 및 측정 시간 등에 따른 최적 분석조건을 확립하고, 각각의 유해 중금속에 대한 검량선을 작성하였다. 유해금속 원소가 포함된 토양 인증표준물질 외에 7종의 다른 토양 시료 중의 유해금속 원소에 대해서도 empirical 법 및 fundamental parameter 법으로 정량분석하고 그 결과를 비교 분석하였다.

• Structural Engineering and Mechanics
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• 제49권1호
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• pp.95-110
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• 2014

The study deals with physical modeling of space frame-pile foundation and soil system using finite element models. The superstructure frame is analyzed using complete three-dimensional finite element method where the component of the frame such as slab, beam and columns are descretized using 20 node isoparametric continuum elements. Initially, the frame is analyzed assuming the fixed column bases. Later the pile foundation is worked out separately wherein the simplified models of finite elements such as beam and plate element are used for pile and pile cap, respectively. The non-linear behaviour of soil mass is incorporated by idealizing the soil as non-linear springs using p-y curve along the lines similar to that by Georgiadis et al. (1992). For analysis of pile foundation, the non-linearity of soil via p-y curve approach is incorporated using the incremental approach. The interaction analysis is conducted for the parametric study. The non-linearity of soil is further incorporated using iterative approach, i.e., secant modulus approach, in the interaction analysis. The effect the various parameters of the pile foundation such as spacing in a group and configuration of the pile group is evaluated on the response of superstructure owing to non-linearity of the soil. The response included the displacement at the top of the frame and bending moment in columns. The non-linearity of soil increases the top displacement in the range of 7.8%-16.7%. However, its effect is found very marginal on the absolute maximum moment in columns. The hogging moment decreases by 0.005% while sagging moment increases by 0.02%.

• 한국작물학회지
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• 제40권4호
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• pp.512-517
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• 1995

질소의 추비가 품질특성에 미치는 영향을 조사하기 위하여 1993년 일본의 동북농업시험장의 화산회토인 포장에서 미유기 보리를 공시품종으로 하여 재생기, 유효분벽기 그리고 출수기에 유안을 질소 성분량으로 2 또는 4kg을 추비하였다. 도종율 백도 조단백질 등을 조사한 결과를 요약하면 다음과 같다. 1. 55% 도종기간은 2kg을 추비하면 길어지나 추비 시기간에는 차이가 없었다. 백도, 경도 그리고 도종율도 추비에 의한 차이는 없었다. 2. 원맥의 조단백질함량은 추비에 의하여 증가하였으나 시기간에는 차이가 없었다. 3. 원맥의 조단백질함량과 55% 도종기간과는 정의 상관관계가 있었으나 8분 도정림의 백도와는 상관이 없었다. 4. 8분 도종율 및 8분도정립의 백도와는 부의 상관관계가 있었고, 8분 도종율과 55% 도종시간과는 정의 상관관계가 있었다. 백도 형질간에는 상관관계가 없었다. 5. 주사형 전자현미경에 의한 미세구조관찰에서 추비처리에 의한 Protein matrix의 차이는 없었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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• pp.85-88
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• 2001

Since mountainous area has access restrictions for field work, assessors need to establish a conceptual model of the contamination prior to the field investigation. In this study we established a conceptual model of the contamination based on site inspection and geological survey, followed by the field investigation for the petroleum spill site. In the conceptual model, we estimated that tile contamination should have spread by groundwater and topographical characteristics within the top soil layer. The spread of contamination through rock was not considered in the conceptual model due to impermeable characteristics of metasyenite. The contaminated environmental media of the petroleum spill site include soil and groundwater. According to the analysis result of the contamination, the volume of contaminated soil is estimated approximately 4, 150 cubic meters (7, 055 ton) with most contaminants existing along the groundwater flow within top soil layer.

• 대한지리학회지
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• 제39권1호
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• pp.45-55
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• 2004

본 논문은 물순환 기구와 지형 발달에 대한 상호작용을 정량적으로 평가하기 위한 일환으로 조사한 내용 중 'U자형 골' 곡두사면의 강우-유출특성과 수분분포 그리고 지중수이동에 관하여 기술하였다. 그 내용은 다음과 같이 요약할 수 있다. 'U자형 골' 전면에 나타난 fissure와 파이프 입구는 직접유출 성분을 토양 파이프 혹은 토양층에 많은 수량을 유입시킴으로서 토양층의 침식을 가속화시켜 토양 파이프의 확대와 발달에 기여할 것으로 간주된다. 그리고 토양에 침투한 대부분의 강우가 파이프류로 유출되고, 나머지 일부가 지하수에 공급됨으로서 강우강도가 작은 강우 이벤트에도 선행강우의 효과에 의해서 지하수위와 파이프류가 민감하게 반응한 것으로 판단된다. 따라서 토양 파이프는 'U자형 골' 곡두사면의 물질수지를 좌우하는 중요한 요인이라 할 수 있다. 그리고 지중수의 비유속은 곡두사면 하단부보다 상단부에서 큰 변화를 나타내고. 강수량에 따라 곡두사면 상단부에 상대적으로 큰 비유속이 부가됨에 따라 'U자형 골' 곡두사면이 상부로 후퇴하는 조건을 제공한다고 생각할 수 있다.

• 농업과학연구
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• 제6권2호
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• pp.125-133
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• 1979

평창군(平昌郡)에 발생(發生)한 산사태지(山沙汰地)의 유형(類型)은 다음과 같으며 그특징(特徵)을 보면, 1. 석회암(石灰岩) 심토지대(深土地帶) 토양단면상(土壤斷面上)에 점토(粘土)의 집적(集積)으로 토성(土性)의 차이(差異)가 뚜렷하여 수분(水分)에 의한 윤활작용(潤滑作用)으로 니류형산사태(泥流型山沙汰)가 발생(發生)한다. 2. 석회암(石灰岩) 암반지대(岩盤地帶) 표토(表土)의 두께가 얇고 평활(平滑)한 암반층(岩盤層)이 존재(存在)하므로 집중호우시(集中豪雨時) 표층토(表層土)가 쉽게 포화(飽和)되고 암반경계부(岩盤境界部)에 수분윤활작용(水分潤滑作用)으로 표토(表土)가 분리(分離) 붕락(崩落)한다. 3. 화강암지대(花崗岩地帶) 조립질토성(粗粒質土性)의 모재(母材)는 응집력(凝集力)이 적으며 공극(孔隙)이 많고 삼투능이 커서 수분(水分)에 의한 식화(蝕和) 및 분리작용(分離作用)이 신속하여 쉽게 기암층(基岩層)으로부터 붕락(崩落) 계안(溪岸)을 침식(浸蝕)한다. 본지역(本地域)의 산사태예방책(山沙汰豫防策)으로 다음을 들 수 있다. 1. 산사태근원지(山沙汰根源地)의 집중조림(集中造林) 및 사방공작물(砂防工作物) 설치(設置). 2. 급경사지(急傾斜地)($25^{\circ}$이상)의 개벌(皆伐) 및 개간경작(開墾耕作)의 억제(抑制) 3. 산사태방비림(山沙汰防備林) 조성(造成).

• Wind and Structures
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• 제30권4호
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• pp.423-432
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• 2020

A steel high-rise building (HRB) with 15 stories was analyzed under the dynamic load of wind or four different earthquakes taking into consideration the effect of soil-structure interaction (SSI) and using tuned mass damper (TMD) devices to resist these types of dynamic loads. The behavior of the steel HRB as a lightweight structure subjected to dynamic loads is critical especially for wind load with effect maximum at the top of the building and reduced until the base of the building, while on the contrary for seismic load with effect maximum at the base and reduced until the top of the building. The TMDs as a successful passive resistance method against the effect of wind or earthquakes is used to mitigate their effects on the steel high-rise building. Lateral displacements, top accelerations and straining actions were computed to judge the effectiveness of the TMDs on the response of the steel HRB subjected to wind or earthquakes.

• 농업과학연구
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• 제42권4호
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• pp.319-324
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• 2015

An estimation of the requirement of minerals based on growth stage and cropping pattern is very important for greenhouse zucchini. This study was performed at farmer's field which was applied with a fertigation system and a semi-forcing cultivation from Feb. to July in 2014, and nitrogen levels were set up with x0.5, x0.75, x1.0 and x1.5 of the NO3-N-based soil-testing recommendation for zucchini cultivation. Top dressing of nitrogen (basal : top = 4 : 6) and potassium (basal : top = 3 : 7) was applied with an interval of every two weeks from two and six weeks after transplanting, respectively, and phosphorus was totally supplied with basal dressing. The nitrogen uptake was the order of x1.0, x0.75, x1.5 and x0.5, phosphorus, x1.0, x0.75, x0.5 and x1.5, and potassium, x0.75, x1.0, x1.5 and x0.5. From these results, it was suggested that highest mineral uptake could be reached between x0.75 and x1.0 of the NO3-N-based soil-testing recommendation. In conclusion, nutrient management based on the growth stage was proven to be better method for favorable growth and yield of zucchini.

• Ocean Systems Engineering
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• 제4권4호
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• pp.263-278
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• 2014

The spudcan requires the suitable design considering the soil, platform, and environmental conditions. Its shape needs to be designed to secure sufficient reaction of soil so that it can prevent overturning accidents. Its shape also has to minimize the installation and extraction time. Even in the same soil condition, the reaction of soil may be different depending on the shape of spud can, mainly the slope of top and bottom plates. Therefore, in this study, the relation between the slope of plates and the reaction of soil with and without water jetting is analyzed to better understand their interactions and correlations. For the investigation, a wind turbine installation jack-up rig (WTIJ) is selected as the target platform and the Gulf of Mexico is considered as the target site. A multi layered (sand overlying two clays) soil profile is applied as the assumed soil condition and the soil-structure interaction (SSI) analysis is performed by using ANSYS to analyze the effect of the slope change of the bottom plate and water jetting on the reaction of soil. This kind of investigation and simulation is needed to develop optimal and smart spudcan with water-jetting control in the future.