• 환경영향평가
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• 제30권4호
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• pp.215-224
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• 2021

본 연구에서는 제련소 주변 납 오염 현장 토양의 위해성 저감을 위한 안정화 적용 효과를 알아보고자 대표적인 상업용 안정화제를 적용 후 안정화 전후의 토양 중 납의 용출 안정성을 TCLP (Toxic Characteristic Leaching Procedure)와 SPLP (Synthetic Precipitation Leaching Procedure) 용출시험을 통해 평가하였으며, 안정화 후 토양내 납의 존재형태 변화를 연속추출(sequential extraction procedure)분석을 통하여 파악하였다. 중금속 오염 토양 안정화 성능을 보유하고 있으며 대량으로 공급이 용이한 안정화제인 석회석, AC-2 (Amron), Metafix (Peroxychem)을 후보로 선정하였다. XRD 분석 결과 AC-2는 CaCO₃, MgO의 결정성을 가지고 있었으며, Metafix는 Fe₇S₈의 결정성을 보유하는 것으로 확인되었다. 안정화 후 토양의 SPLP 용출 시험에서는 대부분의 모든 안정화제 적용 조건에서 국내 환경부 먹는물 기준을 만족하였으며 TCLP 용출시험결과에서는 77.0%의 높은 안정화 효율을 보여주었다. AC-24%와 Metafix 4% 적용에서 SPLP 용출액 중 납의 농도를 검출 한계치 이하로 저감되었으며 TCLP 기준 안정화 효율이 90% 이상인 것으로 확인되었다. 연속추출 결과 Metafix 적용 토양은 이동성이 높은 1, 2단계의 분획 비율이 감소하고 가장 안정한 5단계의 분획 비율이 증가되는 것으로 나타났다. 본 연구의 결과를 종합하였을 때 안정화 효과가 높은 순서는 Metafix>AC-2>석회석인 것으로 판단된다.

• 한국유기농업학회지
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• 제17권1호
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• pp.55-62
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• 2009

저면도포 무처리구에서 유기상토에 느타리버섯 폐배지로 생산한 분립 4-6%의 첨가비율에서 벼의 유식물체의 생육이 가장 좋았다. 저면도포 처리구에서는 대조구(유기상토 100%)에서 벼의 유식물체의 생육이 가장 좋았는데, 이는 신장된 뿌리가 토양표면에 시용된 분립으로부터 생육에 필요한 양분을 흡수하였기 때문으로 추정된다 따라서 장기간 육묘할 경우에는 유기상토에 분립을 혼합하지 않고 토양표면에 분립 100%를 시용하는 저면도포 방법이 효율적이라고 생각된다. 느타리버섯 폐배지로 생산한 분립은 중금속 함량이 낮아서 안전성이 높고. 양분공급능력이 높은 유기상토재로서 이웅 가능성이 높다고 판단된다. 유기상토의 양분공급능력을 높여 유식물체의 생육을 촉진하기 위해서는 분립과 같은 상토재의 첨가를 통하여 질소함량은 높이고, 탄질율은 낮추는 것이 필요하다고 판단된다.

• 상하수도학회지
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• 제26권6호
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• pp.757-766
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• 2012

In this study, we have examined concentration distribution and patterns of PCBs in waters, sediments and soils in an agricultural area of South Korea to investigate the relationship between PCBs sources and concentration levels. The concentration of PCBs in water samples were ranged from lower values below detection limit to 8.25 ug/L and the concentration of PCBs in sediment samples were ranged from lower values below detection limit to 76.67 ug/Kg. The concentration of PCBs in soil samples were ranged from lower values below detection limit to 23.51 ug/Kg. These contamination levels were far below the guideline values suggested for environmental quality assessment. The homologue patterns in samples varied from sample to sample, but isomer patterns were very similar with each other. PCB-138 and PCB-153 were predominant congeners in the soil and sediment, which were similar to the results obtained from previous studies. With these results, the assessment of potential sources of PCBs contamination in the sediments of the Nakdong river basin was performed. The principal components were extracted by Principal Component Analysis(PCA). As the result of PCA, it could be expected that PCBs in samples of this study were more affected by PCB products than combustion processes and mostly affected by already-known sources. The PCBs in the soil and sediment samples were related with commercial PCB products.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1194-1199
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• 2010

Systematic finite element analyses on consolidation were performed with various drainage conditions. Numerical analyses were performed using SAGE CRISP2D, a commercial numerical analysis program for the conventional geotechnical engineering practice. For the input properties of the numerical analyses, incremental loading oedometer tests were performed on reconstituted kaolinite samples. Numerical analyses were performed with various drainage conditions such as vertical, radially inward and outward drainage conditions. For the case of radially inward drainage conditions, a series of numerical analyses were performed with varying the diameter of vertical drains. As a result, the lateral deformation and void ratio variation occurred during consolidation for the radially inward or outward drainage conditions. And the variations of the lateral deformation and void ratio did not fully disappear even after the completion of the consolidation and induced the spatial variations of the soil properties. Keywords : finite element analysis of consolidation, various drainage conditions, lateral deformation, spatial variation of soil properties.

• Advances in Computational Design
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• 제3권2호
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• pp.201-212
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• 2018

Decrease in availability of suitable subbase and base course materials for highway construction leads to a search for economic method of converting locally available troublesome soil to suitable one for highway construction. Present study insights on evaluation of benefits of stabilization of subgrade soils in term of extension in service life (TBR) and layer thickness reduction (LTR). Laboratory investigation consisting of Atterberg limit, Compaction, California Bearing Ratio, unconfined compressive strength and triaxial shear strength tests were carried out on two types of soil for varying percentages of stabilizers. Vertical compressive strains at the top of unstabilized and stabilized subgrade soils were found out by elastoplastic finite element analysis using commercial software ANSYS. The values of vertical compressive strains at the top of unstabilized and stabilized subgrade, were further used to estimate layer thickness reduction or extension in service life of the pavement due to stabilization. Finite element modeling of the flexible pavement layered structure provides modern technology and sophisticated characterization of materials that can be accommodated in the analysis and enhances the reliability for the prediction of pavement response for improved design methodology. If the pavement section is kept same for unstabilized and stabilized subgrade soils, pavement resting on lime, fly ash and fiber stabilized subgrade soil B will have service life 2.84, 1.84 and 1.67 times than that of unstabilized pavement respectively. The flexible pavement resting on stabilized subgrade is beneficial in reducing the construction material. Actual savings would depend on the option exercised by the designer for reducing the thickness of an individual layer.

• International Journal of Industrial Entomology and Biomaterials
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• 제25권1호
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• pp.123-127
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• 2012

An experiment was carried out to boost the production of tasar crops through application of secondary nutrients. Different combinations of secondary nutrients were prepared and its effect was studied on the yield and quality of leaves of tasar food plant Terminalia tomentosa W & A with 2.4 m ${\times}$ 2.4 m spacing and cocoon characters of tasar silkworm Antheraea mylitta Drury reared on them. Among different combinations of secondary nutrients, foliar application of magnesium sulphate (2%, w/v) and basal application of 3 quintal/ha of calcium carbonate (secondary nutrient combination SM5) was found to be the best in crop improvement. It improves the quantity and quality of leaves as well as the commercial characters of cocoons. As a result, silk production improves. Under this combination, leaf yield increased by 26.55% in comparison to control. Average increase in moisture, total mineral, crude protein and total carbohydrate was 3.26%, 20.84%, 15.39% and 17.85% respectively as compared with control. Further, bio assay studies revealed that average larval weight, E.R.R., cocoon weight, shell weight and silk ratio percent increased by 11.25%, 25.71%, 20.05%, 35.14% and 12.17% respectively over control which indicates that secondary nutrient combination $SM_5$ has significant role in improving the production of tasar crops.

• 한국조경학회지
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• 제23권3호
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• pp.80-93
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• 1995

The purpose of this study was to assess functioni fo urban greenspace to reduce atmospheric CO\sub 2\ concentration. The study quantified carbon storage in urban greenspace and carbon emission by fossil fuel consumptio in Chuncheon. The amount of carbon storage in vegetation by land use type was 0.02kg/$m^2$ for commercial land, 4.36kg/$m^2$ for natural land, and 0.54kg/$m^2$ for the other urban lands. In 1994, total amount of carbon emission by fossil fuel consumption was about 257,358 metric tons, and the per capita carbon emission was 1.4 metric ton. Total amount of carbon storage in vegetation was 42,942 metric tons, approximately 17% of the carbon emission. This study excluded quantification of carbon storage in soils. The role of urban greenspace to sequester atomspheric carbon might be much greater, if a soil greenspace to sequester atmospheric carbon might be much greater, if a soil greenspace to sequester atmospheric carbon might be much greater, if a soil carbon storage is included quantification of carbon storage is included. However, increasing coverage of trees and managing them for healthy growth would not be sufficient for avoiding adverse impacts by future climate change. Additional measures should be followed such as an increase of energy use efficiency and development of substitute energy.

• The Plant Pathology Journal
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• 제26권4호
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• pp.346-352
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• 2010

This study was conducted in Bahar and Lalehjin, Hamadan, Iran to assess the biocontrol efficacy of Coniothyrium minitans Campbell against potato white mold caused by Sclerotinia sclerotiorum (Lib.) de Bary under field and greenhouse conditions. In addition, the resistance of common potato cultivars against S. sclerotiorum was determined in a greenhouse experiment. After straw inoculation of six potato cultivars (Pashandi, Istambouli, Agria, Marfauna, Alpha and Spartaan) with S. sclerotiorum, the least disease severity was observed in Spartaan and Marfauna. Agria showed the most susceptibility to S. sclerotiorum. Compared with the healthy control, different concentrations of C. minitans conidia ($10^7$, $10^8$ and $10^9$ conidia/mL) reduced disease severity under greenhouse condition, and a concentration $10^9$ was the most effective treatment. During 2008 and 2009, four field trials were conducted to evaluate the efficacy of C. minitans in different soil and aerial applications on disease incidence of potato white mold. In 2008, soil application of $Contans^{(R)}$ WG (a commercial product of C. minitans) showed the greatest biocontrol capacity whereas soil application of solid-substrate C. minitans was found inferior when compared with other treatments in both Bahar and Lalehjin field sites. In 2009, benomyl application was the most effective treatment in reducing disease incidence in both tested field sites.

• Earthquakes and Structures
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• 제13권6호
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• pp.573-588
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• 2017

The earthquake input is required when the soil-structure interaction (SSI) analysis is performed by the direct finite element method. In this paper, the earthquake is considered as the obliquely incident plane body wave arising from the truncated linearly elastic layered half space. An earthquake input method is developed for the time-domain three-dimensional SSI analysis. It consists of a new site response analysis method for free field and the viscous-spring artificial boundary condition for scattered field. The proposed earthquake input method can be implemented in the process of building finite element model of commercial software. It can result in the highly accurate solution by using a relatively small SSI model. The initial condition is considered for the nonlinear SSI analysis. The Daikai subway station is analyzed as an example. The effectiveness of the proposed earthquake input method is verified. The effect of the obliquely incident earthquake is studied.

• 한국토양동물학회지
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• 제1권1호
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• pp.28-36
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• 1996

A survey for entomopathogenic nematodes was conducted throughout the nine provinvrd and within three city limits during the summer of 1990 and 1991. Six of the nine provinces and one of the three cities were positive for entomopathogenic nematodes. Out of the total 499 soil samples, 23(4.6%) were positive for entomopathogenic nematodes with 19(3.8%) containing Steinernema and 4(0.8%) containing Heterorhabditis. Heterorhabditis bacteriopora and three distinct groups of Steinernema species were idintified. One groups was indentified as S. carpocapsae, another S. glaseri and the other S. monticola based on cross breeding studies. Positive sample sites in each habitat includes 15 of the 415(3.6%) from forests including regrowth areas with shrubs, 1 of the 27(3.7%) from turfgrass including golf courses and parks, 3 of the 24(12.5%) from agricultural fields, 2 of the 16(12.5%) along riparian areas, and of the 17(11.8%) near the seashore. We advocate that more surveys be conducted for entomopathogenic nematodes before commercial sources of nematodes are widely applied which may obscure the naturally-occurring nematodes. A key to Steinernema is provided for the identification.