• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.281-285
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• 2000

The effect of the presence of dissolved organic matters(DOM) on the binding of phenanthrene to cetylpyridinium chloride(CPC) coated sand was investigated. The distribution coefficient of phenanthrene increased with increase of sufactant coverage, and decreased with the presence of dissolved organic matters except for the 1.600mg/g coverage case. Both Aldrich humic acid and extracted dissolved organic matter showed the similar tendency. For the quantification of the overall distribution coefficient, this study presented mass distribution model and estimated the sorption equilibrium coefficients of hydrophobic organic compounds(HOCs) in multi system. The suggested model combined a series of sorption equilibrium relationships including the adsorption of DOMs on sorbents, the binding between HOCs and DOMs, and the sorption of HOCs on sorbents with or without DOMs.

• 한국조경학회지
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• 제31권6호
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• pp.77-84
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• 2004

This study was carried out to analyze the vertical and horizontal distribution of fine root biomass of Pinus thunbergii transplanted in reclaimed land from the sea near Gwangyang Bay. The fine-root biomass according to 6 planting ground types were as follows: 98.5 g DM/$m^2$ for P2, 51.1 g DM/$m^2$ for P6, 47.8 g DM$m^2$ for P5, 44.6 g DM/$m^2$ for P3, 38.2 g DM/$m^2$ for P4, 31.8 g DM/$m^2$ for Pl, respectively. The vertical distribution of fine root biomass decreased at descending soil depths of the 6 mounding types. Fine root biomass was 31∼55% in the topsoil of 20cm depth. Fine root biomass that were related to the Spatial distance from the nearest tree were unevenly distributed horizontally in 6 stands. distribution patterns of fine root biomass were closely related to soil hardness and alkalic cation (Ca++, Mg++, Na+, K+) concentrations. Therefore, in order to have good condition for the growth of landscaping plants, we suggest that there is a need for the construction of planting grounds as well as a need for soil improvement in bad soil environments.

• The Korean Journal of Ecology
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• 제12권3호
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• pp.203-208
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• 1989

This study was objected to figure out the soil microarthropod fauna in forests with different flora, and to elucidate how environmental factors affect the diversity of soil microarthropods. Relationships between the distribution density of soil microarthropods and environmental factors were correlated positively with organic matter and C/N ratio. By the calculation of the contribution coefficients, organic matter, amount of precipitation, C/N ratio, and soil moisture were found to be major environmental factors that affect the distribution of soil microarthropods.

• International Journal of Railway
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• 제6권3호
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• pp.90-94
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• 2013

Cement or lime is generally used to improve the strength of soil. However, bacteria were utilized to produce cementation of loose soils in this study. The microo rganism called Bacillus, and $CaCl_2$ was introduced into loose sand and soft silt and $CaCO_3$ in the voids of soil particles were produced, leading to cementation of soil particles. In this study, loose sand and soft silt typically encountered in Korea were bio-treated with 3 types of bacteria concentration. The cementation (or calcite precipitation) in the soil particles induced by the high concentration bacteria treatment was investigated at 7 days after curing. Based on the results of Scanning Electron Microscope (SEM) tests and EDX analyses, high concentration bacteria treatment for loose sand was observed to produce noticeable amount of $CaCO_3$, implying a significant cementation of soil particles. It was observed that higher calcium carbonate depositions were observed in poorly graded distribution as compared to well graded distribution. In addition, effectiveness of biogrouting has also been found to be feasible by bio-treatment without any cementing agent.

• 농촌계획
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• 제11권4호
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• pp.93-98
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• 2005

A aggregate size distribution of soils is an important in successful crop production in reclaimed tidelands. The aggregate size distribution for this study were determined of 0.1mm, 0.25mm, 0.5mm, 1.0mm, and 2.0mm by wet sieving method. Agricultural activity, period of reclamation showed significant effects on aggregate size distribution in reclaimed tidelands. Aggregate MWD was greater in SS and KH(above 1.0m) than in YSG, GHD, SMG, and DH(below 0.5mm) reclaimed tidelands and tidelands. The percentage of aggregates less than < 2mm for SMG, GHD, and SM reclaimed tidelands and tidelands were ranged 8.9%, 36.7%, and 38.0%, respectively. The percentage of > 0.1mm aggregates for SMG, GHD, and SM reclaimed tidelands were ranged 9.0%, 26.0%, and 48.9%, respectively. Results indicated that aggregate size distribution of reclaimed tidelands and tidelands under various agricultural systems vary with reclamation period and soil type.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.99-101
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• 2003

Unsaturated hydraulic conductivity models have been widely used for the numerical modeling of water flow and contaminant transport in soils. In this study, a simple hydraulic conductivity model is developed by using information of particle-size distribution from the lognormal distribution model and its results are compared with those from the Kosugi-Mualem (KM) model. The accuracy of the proposed model is verified for observed data chosen from the international UNSODA database. Results showed that the proposed model produces adequate predictions of hydraulic conductivities. Performance of this model is generally better than the KM function.

• 한국지하수토양환경학회지:지하수토양환경
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• 제23권6호
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• pp.90-103
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• 2018

Although fluoride is an essential trace element, ingestion of excessive amount of fluoride could have detrimental effect on human health. Generally, the bioavailability of fluoride in soils was low, but it could be harmful to the environment depending on the soil properties. Therefore, it is necessary to understand the concentration distribution, and fate and transport characteristics of fluoride to establish a resonable management strategy for fluoride pollution. This study was conducted to evaluate nationwide fluoride distribution in soils in Korea, as well as its fate and transport characteristics. The average background concentration was 204.5 (15.3~504.8) mg/kg, which is lower than the values of foreign soils. For the three regions of different land use, the average concentration was 229.6 mg/kg in region 1, 195.7 mg/kg in region 2, and 273.4 mg/kg in region 3. The concentration of fluoride was the highest in soils from Youngnam block within tectonic structure derived from metamorphic rocks. The results of sequential extraction to access F bioavailability showed fluoride in soils mainly existed as a residual form, which suggests the bioavailability of fluoride was relatively low. Soil properties such as soil pH, CEC, and clay content were found to affect F bioavailability of soil.

• 한국토양비료학회지
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• 제40권3호
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• pp.221-228
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• 2007

제주도 토양의 분포특성을 객관적으로 파악하기 위하여 인접정도 및 해발고도별 토양통의 분포를 GIS기법을 이용하여 정량화하고 이를 바탕으로 통계분석을 실시하였다. 토양통 간의 인접정도는 각 통별 경계의 인접비율로 나타내었고 이를 토양통의 고유특성으로 파악하여 군집분석을 실시한 결과 5개의 군집으로 분류할 수 있었고, 이러한 결과는 정밀토양도에서 토색별로 4개의 토양군으로 구분한 분류체계와 유사한 결과였다. 정밀토양도에서는 토색, 해발고도, 토양의 화학적 특성 등 다양한 근거로 분류하였으나 이번 연구에서는 인접성 한 개의 기준으로 분류한 것으로 인접정도의 관점에서 볼 때 관행의 분류체계가 합리적일 수 있음을 의미하고 있다. 해발고도별 토양통 분포면적으로부터 토양통의 대표해발고도를 수치화할 수 있었고, 이를 바탕으로 토양통간 해발고도별 분포순서를 정할 수 있었다. 분포순서는 한라산의 정상에서 4면의 해안방향으로 갈색산림토 - 흑색토 - 농암갈색토 - 암갈색토의 순서로 토양이 연쇄되고 있어, 제주도 토양의 생성과정과 밀접하게 연관되는 것으로 추정되었다.

• 미생물학회지
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• 제12권1호
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• pp.15-24
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• 1974

This experiment has been carried out with a view to elucidating the distribution of Azotobacter and their population size in rhizosphere and sea and designed ro compare the results with some environmental factors. Results of the experiment are summarized as follows: 1) It was observed that the population sizes of Azotobacter were decided upon the moisture content of soil and that the soil pH was one of the most impertant factors influencing the distribution of Azotobacter. 2)Population sizes of Azotobacter in rhizosphere were changed in accordance with the kinds of vegetation on soil: The rhizosphere where bamboo, corn, legume, and oak inhabit showed the largest population size of Azotobacter. On the other hand, rhizosphere of ginseng revealed no Azotobacter. However, the largest population of general fungi were measured at the rhizosphere. 3)Comparing the population sizes of general microbes in rhizosphere with those of non-rhizosphere, the population sizes of microbes in rhizosphere are larger than those of non-rhizosphere. 4)In coastal environments, population sizes of Azotobacter in surface water of sea are similar to those of the soil(mud) of tidal land. But the sizes are generally smaller than those of terrestrial soils.

• 오토저널
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• 제13권4호
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• pp.76-84
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• 1991

The off-road tractive performance of tracked vehicles can be evaluated in terms of soil thrust, motion resistance and drawbar pull. The ability to predict accurately ground pressure distribution under track is of importance since the vehicle sinkage and motion resistance are closely related to it. While the formulation of the method for predicting ground pressure distribution follows closely in spirit the ideas outlined for the terrain with linear pressure- sinkage relation case by Garber and Wong, the analysis of various terrain stiffness is magnified by numerical implementation procedure. The effects of soil parameters on tractive forces can be introduced through the terrain-track interaction such as pressure-sinkage and shearing characteristics. It is illustrated by determining the drawber pull-slip relation and corresponding ground pressure distribution for the terrains typically chosen and by comparing the results with the conventional ones based on normal ground pressure. The factorial experiment method is finally adopted for checking the sensitivity of the values of soil parameters on the drawbar pull.