• 한국산림과학회지
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• 제47권1호
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• pp.52-61
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• 1980

본(本) 연구(硏究)는 한국삼림토양(韓國森林土壤)의 특성(特性)을 비악(把握)하여 그 합리적(合理的) 이용(利用) 및 관리방법(管理方法)을 제공하기 위하여 실시되었다. 현재(現在)까지 조사발표(調査發表)된 토양(土壤)의 종류(種類)는 178개(個) 토양통(土壤統)으로 그중 64개(個) 토양통(土壤統)이 삼림토양(森林土壤)이다. 삼림토양(森林土壤)은 그 풍화모재(風化母材)의 종류(種類)에 따라 산악잔적토(山岳殘積土), 구릉잔적토(丘陵殘積土), 곡간붕적토(谷間崩積土), 충적토(沖積土) 및 화산회토(火山灰土)로 구분(區分)하여 분석(分析)하였다. 본(本) 논문(論文)에서는 토양(土壤)의 분류학적(分類學的) 특성(特性)과 모암(母岩), 토성(土性) 및 배수상태(排水狀態)를 다루고 있다. 기타 물리적(物理的), 화학적(化學的) 특성(特性)은 다음 논문(論文)에서 서술될 예정이다. 분류(分類)된 한국삼림토양(韓國森林土壤)의 특징(特徵)은 다음과 같다. 1. 산악잔적토(山岳殘積土)(29개통(個統))는 대부분(大部分) Lithosols로서 토양단면(土壤斷面)의 층위분화(層位分化)가 발달(發達)하지 못하였고 토성(土性)은 석력(石礫)이 있는 양토(壤土)가 가장 많고 점질(粘質)로 갈수록 토양통수(土壤統數)가 감소하며 배수상태(排水狀態)는 과도(過度)하다. 2. 구릉잔적토(丘陵殘積土)(19개통(個統))는 대부분(大部分) Red-yellow Podzolic Soils로서 단면(斷面)이 잘 발달(發達)되어 있고 토성(土性)은 주 로 양토(壤土)와 식토(埴土)로 되어 있으며 토양배수(土壤排水)는 양호(良好)하다. 3. 곡간붕적토(谷間崩積土)(13개통(個統))는 주로 Regosols로서 단면발달(斷面發達)이 미약하나 일부 층위분화(層位分化)가 이루어진 Red-Yellow Podzolic Soils와 Acid Brown Forst Soils 가 있다. 토성(土性)은 다양(多樣)하나 조립질(粗粒質)인 경향(傾向)이 있고 배수(排水)는 양호(良好)하다. 4. 각종모암(各種母岩)의 풍화산물(風化産物)의 토성(土性)을 보면 다음과 같다. 1) 조립질토성(粗粒質土性)을 생산(生産)하는 모암(母岩)들로는 유문암(流紋岩), 화강편마암(花崗片麻巖), 편암(片岩), 혈암(頁岩), 사암(砂岩), 역암(礫岩) 등(等)이 있다. 2) 미립질토성(微拉質土性)을 생산(生産)하는 모암(母岩)들로는 석회암(石灰岩), 현무암(玄武岩), 반려(斑糲岩) 및 안산반암(安山斑岩)이 있다. 3) 여러가지 토성(土性)을 다양(多樣)하게 생산(生産)하는 모암(母岩)으로는 화강암(花崗岩)이 있다.

• 한국토양비료학회지
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• 제45권1호
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• pp.79-82
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• 2012

Blossom-end rot is probably the most recognizable Ca deficiency that affects fruit production including pepper. We investigated the induction of blossom-end rot during the period of rapid vegetative growth and fruit setting, and the effect of Ca fertilization on the suppression of blossom-end rot in pepper plants grown in a plastic-film house. During the first fruit setting period, more than 60% of pepper fruits larger than 8 cm showed the symptoms of blossom-end rot. Under the condition of transpiration occurring at a much faster rate, growing leaves of pepper plants could be the greater sinks for Ca than developing fruits. The incidence of blossom-end rot was significantly decreased after two weeks of Ca fertigation. Calcium application during the rapid vegetative growth and fruit setting period could be suggested as a preventive step to overcome the local Ca deficiency inducing blossom-end rot of pepper fruits.

• Advances in environmental research
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• 제4권2호
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• pp.105-117
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• 2015

The groundwater is a very important part of the environment and must be protected for the benefit of the present and future generation. The contamination of soil and groundwater by chemicals has become an increasing concern in the recent past. These chemicals enter the groundwater system by a wide variety of mechanisms, including accidental spills, land disposal of domestic and industrial wastes and application of agricultural fertilizers. Once introduced into an aquifer, these contaminants will be transported by flowing groundwater and may degrade water quality at nearby wells and streams. For improving the management and protection of groundwater resources, it is important to first understand the various processes that control the transport of contaminants in groundwater. Predictions of the fate of groundwater contaminants can be made to assess the effect of these chemicals on local water resources and to evaluate the effectiveness of remedial actions. In this study, an attempt has been made to investigate the behaviour of solute transport through porous media using laboratory experiments. Sodium chloride was used as a conservative chemical in the experiment. During the experiment, pulse boundary condition and continuous boundary conditions were used. Experimental results have been presented for conservative solute transport in the sand. The pattern of the break through curve remains almost same in all the cases of varying flow rate and initial concentration of conservative chemical.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.111-118
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• 2002

Recent study of soft clay of Nakdong-River basin has been taken correlation between soil properties by regression analysis without distribution whether the sample is disturbed or not, or treated as a whole area without proposing local correlation equation to Jang-U or Dae-Joe which has a specific locality. Accordingly, Those tendency cause the reliability of correlation between compression index and void ratio low and then design underestimate and uncertain eventually. In this study, Distributing the soft clay of Nakdong-River basin with failure strain of 6%, the suggestion by Skempton(1957), TakeNaka(1966)-the more sample is undisturbed, the more the ratio of E$\_$50/ and ｑ$\_$u/, ${\alpha}$ = E$\_$50//(q$\_$u//2) = 1/$\varepsilon$$\_$50/ is high-is satisfied with the value of which ${\alpha}$ is 50 and It could be taken enough data in the condition of domestic. Besides other indices also make the distribution suitable. In conclusion, This study is supposed to propose the locally subdivided regression equation between compression index and void ratio considering the sample disturbance.

• 상하수도학회지
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• 제16권6호
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• pp.686-699
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• 2002

The purpose of this study is to estimate deterioration factors and weighting factors in pipe network which each local self-governments takes rehabilitation and replacement work present time. Deterioration factors in pipe network are able to effected of specific province or location related with water supply. Most of water supply pipes are laid under the ground, it is hard to quantify deterioration degree of water system. Moreover, the timing and economic limitation and insufficient information on the spot survey gives a difficulty to look over how old water supply system is. Accordingly, this study collects and analyses five data as the laying environment, visual analysis, analysis of soil contents, analysis of pipe material, and questionary survey data in water pipe of A city. The deterioration factor estimates 14 factors with excavation and experimental analysis and 9 factors without excavation and experimental analysis. Also, the weighting factors are estimated by using the multiple linear regressions and the linear programming. The estimated deterioration factor and weighting results are compared the analysis result of visual, pipe material, and soil contents with the Probabilistic Neural Network Model. Consequently, the model results of estimated 9 factors in this study and 14 factors show the 1-2% difference. The result show that the proposed model could be used to decide the deterioration condition of pipe line with real excavation and experimental analysis.

• Earthquakes and Structures
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• 제10권5호
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• pp.1233-1251
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• 2016

In this paper, it is aimed to determine the stochastic response of a suspension bridge subjected to spatially varying ground motions considering the geometric nonlinearity. Bosphorus Suspension Bridge built in Turkey and connects Europe to Asia in Istanbul is selected as a numerical example. The spatial variability of the ground motion is considered with the incoherence, wave-passage and site-response effects. The importance of site-response effect which arises from the difference in the local soil conditions at different support points of the structure is also investigated. At the end of the study, mean of the maximum and variance response values obtained from the spatially varying ground motions are compared with those of the specialised cases of the ground motion model. It is seen that each component of the spatially varying ground motion model has important effects on the dynamic behaviour of the bridge. The response values obtained from the general excitation case, which also includes the site-response effect causes larger response values than those of the homogeneous soil condition cases. The variance values calculated for the general excitation case are dominated by dynamic component at the deck and Asian side tower. The response values obtained for the site-response effect alone are larger than the response values obtained for the incoherence and wave-passage effects, separately. It can be concluded that suspension bridges are sensitive to the spatial variability of ground motion. Therefore, the incoherence, the wave-passage and especially the site-response effects should be considered in the stochastic analysis of this type of engineering structures.

• 대한토목학회논문집
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• 제36권3호
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• pp.471-491
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• 2016

고전적인 한계 평형 해석에서 얕은 기초의 지지력은 토체 내부의 파괴면을 가정하여 시작한다. 하지만 입상체 역학의 관점에서 토체의 파괴는 접촉력 사슬 구조의 국부적인 좌굴에 의해 시작된다. 본 연구에서는 모형 토립자를 이용하여 구성한 입상체 상부에 얕은 기초 하중을 재하하여 파괴 시까지 입상체 내부의 접촉력 사슬 분포가 어떻게 변화하는지 관찰하였다. 초기 결함이 없이 규칙적인 구조를 가지는 조건과 입상체 하부에 초기 국부적인 불완전성이 있는 조건을 가진 두 가지 종류의 입상체를 준비하여 실험하였다. 입상체 내부에서 발생하는 접촉력 사슬 구조의 방향 분포는 초기 불완전성의 여부에 따라 매우 큰 차이를 보였다. 초기 불완전성이 있는 입상체는 결함이 없는 입상체가 견딘 하중의 67%만을 견딜 수 있었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권3호
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• pp.64-81
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• 2016

To analyze the influence of various groundwater flow rates (specific discharge) on BHE system with balanced and unbalanced energy loads under assuming same initial temperature (15℃) of ground and groundwater, numerical modeling using FEFLOW was used for this study. When groundwater flow is increased from 1 × 10⁻⁷ to 4 × 10⁻⁷m/s under balanced energy load, the performance of BHE system is improved about 26.7% in summer and 22.7% at winter time in a single BHE case as well as about 12.0~18.6% in summer and 7.6~8.7% in winter time depending on the number of boreholes in the grid, their array type, and bore hole separation in multiple BHE system case. In other words, the performance of BHE system is improved due to lower avT in summer and higher avT in winter time when groundwater flow becomes larger. On the contrary it is decreased owing to higher avT in summer and lower avT in winter time when the numbers of BHEs in an array are increased, Geothermal plume created at down-gradient area by groundwater flow is relatively small in balanced load condition while quite large in unbalanced load condition. Groundwater flow enhances in general the thermal efficiency by transferring heat away from the BHEs. Therefore it is highly required to obtain and to use adequate informations on hydrogeologic characterristics (K, S, hydraulic gradient, seasonal variation of groundwater temperature and water level) along with integrating groundwater flow and also hydrogeothermal properties (thermal conductivity, seasonal variation of ground temperatures etc.) of the relevant area for achieving the optimal design of BHE system.

• 한국토양비료학회지
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• 제6권3호
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• pp.173-177
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• 1973

장려품종이며 온대형질(溫帶形質)인 진흥(振興)과 열대형질(熱帶形質)인 다수성신품종(多收性新品種) IR667을 사용(使用)하여 포장조건(圃場條件)에서 질소(窒素) 수준(水準)에 따른 생산반응을 비교(比較) 검토(檢討)하여 본 결과(結果) 다음과 같다. 1. IR667은 진흥(振興)에 비(比)하여 질소고수준(窒素高水準)에서 엽면적(葉面積) 및 수량(收量)이 높고, 2. 질소증시(窒素增施)에 따른 수수(穗數), 입수(粒數), 입종(粒重), 등숙율(登熟率)의 증가(增加)가 더 크며, 3. 단위시비질소당(單位施肥窒素當) 곡실(穀實) 및 엽면적(葉面積) 생산효율이 높으며, 4. 단위엽면적당(單位葉面積當) 곡실생산력이 높았으며, 5. IR667은 수수(穗數) 및 입수형(粒數型)인데 비하여 진흥(振興)은 입종형(粒重型)이었다. 6. 이상(以上)의 제특성(諸特性)은 IR667이 진흥(振興)에 비하여 포장(圃場)에서 강(强)한 생산성내비성임을 보여주었다.

• 환경영향평가
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• 제32권5호
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• pp.269-278
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• 2023

서울 도심에 있는 어린이 모래 놀이터의 안전한 사용을 확인하기 위해 토양 중금속(Cd, Cu, As, Pb, Zn, Ni, Hg, Cr⁶⁺) 오염현황을 조사하였다. 시료 채취 장소는 서울시 7개 자치구에서 281개소를 선정하였다. 본 연구에서 중금속의 전체 평균 농도는 Cd 0.21 mg/kg, Cu 5.97 mg/kg, As 2.40 mg/kg, Pb 7.55 mg/kg, Zn 34.08 mg/kg, Ni 4.22 mg/kg, Hg 0.02 mg/kg였다. Cr⁶⁺은 불검출되어, 이를 포함하는 중금속 7종 모두 토양오염우려기준 1 지역 기준보다 낮은 것으로 나타났다. 아울러 토양오염등급(SPC)을 평균값으로 평가했을 경우에 7개 자치구 모든 지점에서 1등급인 100 미만인 것으로 나타나 건전한 토양 상태임을 보였다. 하지만 최대값으로 평가했을 경우 5개 자치구에서 일부 100 이상의 값을 나타내었다. 따라서 안전한 토양환경을 위하여 어린이 놀이터의 관리주체인 지자체의 지속적인 관리와 관심이 필요한 것으로 보인다.