• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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• pp.202-205
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• 2001

In this study, the electrokinetic remediation test for the kaolin contaminated by lead was performed and voltage, zeta potential, pH distribution, current, contamination transport in soil sample were studied and finite differential numerical analysis program(HERP) for a contaminated soil were compared with those of test. From the result of HERP, in the anode it was represented that the rest concentration was decreased with the voltage. Hence, if treatment time was continued for a long in the constant voltage, comparing with sample having no change in the rest concentration, it is considered that the voltage gradient is the control factor of the rest concentration.

• Geomechanics and Engineering
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• 제23권5호
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• pp.431-439
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• 2020

Soil-water retention curve (SWRC) contains key information for the application of unsaturated soil mechanics principles to engineering practice. The SWRC variables are commonly used to describe the hydro-mechanics of soils. Generally, these parameters are determined using the graphical method which can be time consuming. The SWRC is highly dependent on the pore size distribution (PSD). Theoretically, the PSD obtained by mercury intrusion porosimetry test can be used to determine some SWRC variables. Moreover, the relationship between SWRC and shrinkage curve has been investigated. A new method to determine total SWRC variables directly without curve-fitting procedure is proposed. Substituting the variables into linear SWRC equations construct SWRC. A good agreement was obtained between predicted and measured SWRCs, indicating the validity of the proposed method for unimodal SWRC.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권6호
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• pp.57-65
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• 2017

Six soil subsampling methods were evaluated with explosive compounds-contaminated soils to quantify the variance associated with each method. The methods include modified grab sampling, simplified ripple splitting, fractional shoveling, coning & quatering, degenerate fractional shoveling, and rolling & quatering. All the methods resulted in significantly lower CV (coefficient of variation) of 1~5%, compared to common grab sampling that gave 8~98% of CV, possibly due to the reduction of grouping and segregation errors described by Gy sampling theory. Among the methods, simplified ripple splitting tends to result in lower explosive compounds concentrations, while the rolling & quatering gave the opposite result. Fractional shoveling method showed the least variance and the highest reproducibility in the analysis.

• 한국CDE학회논문집
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• 제20권3호
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• pp.230-237
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• 2015

Soil deformation on the off-load ground is significantly affected by soil conditions, such as soil type, water content, and etc. Thus, the soil characteristics should be estimated for predicting vehicle movements on the off-load conditions. The plate-sinkage test, a widely-used experimental test for predicting the wheel-soil interaction, provides the soil characteristic parameters from the relationship between soil stress and plate sinkage. In this study, soil stress under the plate-sinkage situation is calculated by the DEM (Discrete Element Method) model. We developed a virtual soil bin with DEM to obtain the vertical reaction forces under the plate pressing the soil surface. Also parametric studies to investigate effects of DEM model parameters, such as, particle density, Young's modulus, dynamic friction, rolling friction, and adhesion, on the characteristic soil parameters were performed.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 춘계학술대회 논문집
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• pp.152-162
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• 2001

Comparison of results from two different methods of soil-structure dynamic interaction analysis is presented. Two methods include transfromed static and seismic response analyes. In seismic response analysis, the difference in result of total stress analysis relative to effective stress analysis is investigated.

• 한국약용작물학회지
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• 제28권3호
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• pp.209-220
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• 2020

Background: This study investigated the effects of soil properties on the soil fungal community in first and continuous cultivation areas of Cnidium officinale Makino. Methods and Results: The soil fungal community was analyzed for relative abundance and principal coordinate analysis (PCoA) was conducted using Illumina MiSeq sequencing. The correlation between the soil chemical properties and the soil fungal community was assessed with distance-based linear models (DISTLM). The soil fungal community showed distinct clusters consisting in the continuous cultivation area of C. officinale Makino. PCoA and DISTLM indicated that soil pH, calcium, and available P₂O₅ significantly affected the soil fungal community in the cultivation area of C. officinale Makino. In addition, considering 5 different pathogenic fungi the relative abundance of Fusarium in the continuous cultivation area was significantly higher compared to that in the first cultivation area of C. officinale Makino. Conclusions: This study is important because it has determinined the effects of soil properties on the soil fungal community in both first and continuous cultivation areas of C. officinale Makino. Moreover, these results will be helpful to investigate the cause of continuous cropping obstacle in C. officinale Makino by examining the changes of soil fungal community.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.57-59
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• 1998

The headspace method has been acknowledged as a cost-effective and convenient method to analyze volatile organic compounds(VOCs) in soil. The headspace analysis is based on equilibrium partitioning of VOCs among water, air and soil in a closed system. However, the headspace method cannot be applied to soils where most of the VOCs remain sorbed even at high temperature. In this study, it was investigated how the sorption characteristics of VOCs varied with soil with different organic carbon contents and temperature. This study showed that all the VOCs were volatilized, not sorved, only in the soil with 5% organic carbon at 45$^{\circ}C$ or higher. Some fraction of VOCs remained in soil with 8% organic carbon at $65^{\circ}C$ of higher. Most of the VOCs remained sorbed in soil with 12% organic content even at 95$^{\circ}C$. This result suggested that the headspace method can be applied only to soils with little organic carbon content (less than 5%). In this case, 45$^{\circ}C$ seems to be high enough to volatilize all the VOCs from soil. Large particles still showed a significant sorption capacity for VOCs from soil. Large Particles still showed a significant sorption capacity for VOCs despite of their low level of organic carbon content. It was also shown that the organic carbon sorption coefficients (Koc) of VOCs varied with soils with different organic carbon content. This suggests that not only the organic matter content of soil but also the property of the organic matter in soil influence the sorption of VOCs to soil.

• 한국염색가공학회지
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• 제8권1호
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• pp.83-89
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• 1996

Carbon black has been used as a particulate soil to prepare artificial soiled fabrics for detergent study but it has two major defects. The one is the difficulty of quantitative analysis of carbon black for evaluate the detergency, the other is that there is no reliable correlation between the removal of carbon black and oily soil which is the major component of natural soil. In this study ferric oxinate was used as a particulate soil since it is in black color and can be soiled on fabric by suspension in water or by solution in chloroform and it is easily analysed quantitatively by extracting it from soiled fabric with chloroform to get correct value of soil removal. The characteristics of soil removal of ferric oxinate were compared with that of carbon black and Sudan black, an oil soluble dye, which had been proved that it's detergency correlated with that of oily soil The soil removal of ferric oxinate and Sudan black estimated from quantitative analysis and from K/S value were in good agreement whereas the result calculated by simple reflectance was consistently low. The soil removal of ferric oxinate was exceeded from that of carbon black without regard to surfactants, Triton and Las, but the effect of washing conditions such as temperature and washing time on soil removal of both soils with different suffactants showed no considerable difference. Though the soil removal of Sudan black was little effected by the conditions, the soil removal in Triton exceeded considerably that of in Las, which is the characteristic of oily soil. Thus the soil removal of Sudan black was in good agreement with ferric oxinate in Triton, a non-ionic surfactant, and with carbon black in Las, an artionic surfactant. We concluded that ferric oxinate is a more realistic model particulate soil for artificial soiled cotton fabric washed with non-ionic surfactant than carbon black.

• 한국지반신소재학회논문집
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• 제5권2호
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• pp.1-8
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• 2006

오염토양의 현장정화에 있어서 지반 및 오염물질의 물성치는 정화에 소요되는 시간과 함께 매우 중요한 고려사항이다. Gabr 등(1996)은 연직배수재가 설치된 오염지반에서 시 공간적 변화에 따른 초기오염농도에 대한 오염농도비($C/C_0$)를 구하는 식을 유도하였다. 본 연구에서는 Gabr 등이 유도한 식의 전산모형 FLUSH1을 이용하여 오염지반 흙의 유효입경, 간극률, 형상계수, 밀도, 지반의 온도와 오염물질의 단위중량 및 점성계수가 오염정화에 미치는 영향을 알아보기 위하여 시 공간적 변화에 따른 오염농도비($C/C_0$)를 분석 하였다. 분석결과 연직배수재가 설치된 오염지반에서 정화에 크게 영향을 미치는 인자는 오염지반 흙입자의 유효입경인 것으로 나타났으며, 그 다음으로 오염물질의 점성, 오염지반 흙의 간극율, 형상계수, 지반의 온도, 오염물질의 단위중량, 흙의 밀도 순으로 분석되었다. 오염지반 흙의 밀도는 오염정화에 미치는 영향이 아주 작은 것으로 나타났다.

• 한국토양비료학회지
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• 제48권5호
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• pp.436-441
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• 2015

The chemical properties of paddy fields in Gyeonggi province were monitored every 4 years from 1999 to 2015 in order to provide basic information for soil fertility management of paddy fields. In 2015, the soil chemical properties of paddy fields were 5.9 in pH, $23g\;kg^{-1}$ in organic matter (OM), and $84mg\;kg^{-1}$ in available phosphate (Avail. $P_2O_5$). Exchangeable (Exch.) potassium (K), calcium (Ca) and magnesium (Mg) were 0.30, 5.1 and $1.3cmol_ckg^{-1}$, respectively, and available silicate (Avail. $SiO_2$) was $129mg\;kg^{-1}$. In the long-term analysis, the contents of Avail. $SiO_2$, Exch. Ca and pH of paddy soils showed increasing tendency. However, Avail. $P_2O_5$ and Exch. K tended to decrease, and there were no significant changes in the contents of OM and Exch. Mg. Paddy soil within appropriate pH range increased from 44% in 1999 to 76% in 2003, 84% in 2007, 63% in 2011, and 80% in 2015. But soil within appropriate range of Exch. Ca tended to decrease, showing 36% in 1999, 42% in 2003, 38% in 2007, 37% in 2011 and 32% in 2015. In case of Avail. $SiO_2$, soil within appropriate range increased from 14% in 1999 to 17% in 2003, 18% in 2007, 16% in 2011, and 31% in 2015. As a result, paddy fields with less in nutrient level need to be more fertilized based on soil analysis. And the application of silicate fertilizer is strongly recommended to those of paddy fields in need. Also soil management such as the cultivation of green manure crop or application of rice straw will be necessary to increase the organic matter content of paddy soil.