• 한국대기환경학회지
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• 제20권5호
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• pp.685-695
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• 2004

Size-segregated measurements of aerosol composition are used to estimate the transport of natural and anthropogenic aerosols at Gosan site during May 2002. The results of measurement show that not only soil dust but also anthropogenic aerosols, including sulfur and enriched trace metals such as Pb, Zn, Cu, are transported to Gosan. This study combines the size- and time-resolved aerosol composition measurements with factor analysis in order to identify some source materials. As a result, coarse particles (2.5${\mu}m$~12${\mu}m$) are influenced by soil, sea-salt, coal, coal combustion, and nonferrous sources. But fine particles have different sources. The fine particles, which the diameter is from 0.56${\mu}m$ to 2.5${\mu}m$, are more affected by road dust, oil combustion, industry. municipal incineration, and ferrous metal sources. The very fine particles, from 0.09${\mu}m$ to 0.56${\mu}m$, mainly supplied by biomass burning, oil combustion, nonferrous and ferrous metal sources.

• 한국산학기술학회논문지
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• 제10권7호
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• pp.1642-1647
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• 2009

황사기간 중 천안시 대기 입자의 특성 변화를 파악하기 위해, Cascade Impactor를 장착한 High Volume Air Sampler를 이용하여 대기 시료를 채취하여, 대기 입자의 입경별 질량농도 및 이온, 금속 성분의 농도를 황사기간과 비황사기간에 비교 측정하였다. 황사기간 중 일평균 TSP, PM10, PM2.5 평균 농도가 각각 214.9, 160.3, 95.9${\mu}\;g/m^3$으로, 비황사기간에 비해 각각 평균 3.08, 2.58, 1.95배 증가하였으며, 최대 농도는 TSP, PM10, PM2.5가 각각 850.1, 534.4, 233.3${\mu}\;g/m^3$으로, 비황사기간에 비해 각각 12.19, 8.60, 4.76배까지 증가하였다. 황사기간 중 농도의 증가는 미세입자보다는 조대입자에서 현저하였으며, 미세입자와 조대입자 모두 수용성 이온성분의 증가는 미미한 반면, 토양의 주요 구성 성분인 Fe, Al, Ti의 증가가 뚜렷이 관측되어, 토양구성 금속성분이 황사기간 중 입자 농도 증가의 주요원인 물질임을 확인할 수 있었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권2호
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• pp.1-7
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• 2016

Ferrous slag is a by-product from steel making process and waste concrete is generated from construction activities. Large part of ferrous slag and waste concrete are recycled as construction materials. However, Ca²⁺ leaching out of ferrous slag and waste concrete in the water-contacting environment can cause a strength change. Strength can be reduced due to the dissolution of solid form of CaO which is one of the main contents of ferrous slag and waste concrete. On the other hand, strength can be enhanced due to the pozzolanic reaction of cementitious components with water. In this study, steelmaking slag, blast furnace slag, and waste concrete were aged by exposure to raining events, and the change of their compaction and shear strength characteristics was investigated. Optimum moisture content of all materials used in this study increased with aging period while maximum dry unit weight slightly decreased, implying that the relative contents of fine particles increased as the CaO solid particles were dissolved. Internal friction angle and shear strength of recycled materials also increased with aging period, indicating that the materials became denser by the decrease of void ratio attributed to the fine particles generated during the weathering process and the development of cementitious compounds increasing the bonding and interlocking forces between the particles. The results of this study demonstrated that mechanical strength of recycled materials used as construction materials has little chance to be deteriorated during their service life.

• Journal of Korean Society for Atmospheric Environment
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• 제16권E호
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• pp.29-38
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• 2000

For the detailed characterization of atmospheric aerosol, the analysis of single particle is highly valuable. In this study, to investigate the characteristics of single Asian dust storm particles, scanning electron microscope(SEM) coupled with and energy dispersive X-ray microanalyzer(EDX) and micro-PIXE were applied. Sampling was performed at Kyoto University located in Kyoto, Japan, in spring of 1999. Mass concentration during Asian dust storm events was higher roughly 3∼5 times than measured in the season of the highest concentration. Single particles were generally sharp-edged and irregular in shape and contained mostly crustal elements. Significant amount of S in coarse fraction was detected in individual particles. A large particles in coarse fraction existed as the mixture of soil components and S. A good agreement between the result of SEM-EDX analysis and that iof micro-PIXE analysis was obtained in this study.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.338-341
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• 2002

This work is the basis research to apply Hydrocyclone for the separation and the thickening to the reservoir sediment. Chemical analysis result showed that organic contaminants were abundantly found in smaller sediment particles. As a result of the experiment device that higher reduced efficiency was obtained under the high velocity and low concentration with the small cyclones.

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 1997년도 정기학술강연회 발표논문 초록집 Annual Meeting of Korean Society of Coastal and Ocean Engineers
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• pp.45-52
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• 1997

Ocean seabed is usually covered with various types of marine soils. A marine soil is a mixture of two phases: soil particles that forms an interlocking skeletal frame, pore fluids that occupy a major portion of pore space. When gravity water waves propagate over a porous movable seabed, a hydrodynamic pressure on the fluid-seabed interface and fluid flow in the porous medium are induced. (omitted)

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.940-950
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• 2010

In case of uneven surcharge like backfill or embankment after constructing caisson applied on the deep soft marine deposits, lateral deformation of soft soils would happen due to plastic deformation of soil particles by increase of excess pore water pressure. Lateral deformation of soil will result in the caisson displacement which affects soft soil-caisson structure safety. Soft soil was improved by soil compaction pile method, and then gravity caisson was installed. Soil deformations were monitored and analyzed with step by step backfill and embankment behind the caisson. Amount and speed of lateral deformation after the installation of caissons were closely related with the time of backfill and embankment. The relationship between maximum lateral displacement($\Delta_y$) in front of caisson and settlement($\Delta_s$) can be expressed as $\Delta_y=(0.0871)\Delta_s+122.95$. Soft soil depth did not affect the lateral displacement of caisson in this study, which can be explained the soft soil improvement under the caisson by S.C.P. method. Substantially the amount and speed of the lateral deformation of caisson were closely related with the uneven surcharging rate behind caisson.

• 대한공간정보학회지
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• 제12권4호
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• pp.75-81
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• 2004

임하호 유역은 지질 및 토지피복 상태가 토사유실에 취약한 특성을 가지고 있어, 강우발생시 토사가 하천에 유입되어 호소내에 많은 탁수가 발생하고 있다. 본 연구에서는 임하호 탁수 저감대책을 수립하기 위한 기초자료를 생성하기 위해 GIS 기반RUSLE 모형을 이용하여 임하호 유역의 토사유실량을 분석하였다. 2003년도 강우자료를 이용하여 토사유실량을 분석한 결과 5,782,829 ton/yr로 계산되었으며, 소유역별 분석에서는 동부천이 가장 높은 토사유실량을 나타내었다. 또한 태풍매미때의 탁수실측자료를 이용하여 RUSLE 모델로 산정한 토사유실량의 적정성을 평가할 수 있었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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• pp.182-186
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• 2001

An acid forest surface soil as a land farming medium was treated with a water plant alum sludge at 0 to 18%. Indian mustard was grown in the treated soil in a greenhouse for 5 weeks and watered with pH 4 tap water adjusted with a mixed acid (1HNO$_3$: 2H$_2$SO$_4$) during plant growth. Changes in soil property, leachate chemistry, plant growth, and plant uptake of elements by the sludge treatment were determined. The alum sludge treatment increased buffer capacity to acidity, hydraulic conductivity, water holding capacity, and phosphate adsorption of the soil and decreased bulk density and mobility of small particles. The sludge treatment reduced leaching of Al, Mg, K, Na, and root elongation. Plant did uptake less amount of the cations and P but more Ca with the sludge treatment.

• 한국지반환경공학회 논문집
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• 제19권4호
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• pp.17-26
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• 2018

This study systematically examines the changes in the compressive and tensile strength of soil cement reinforced by natural hair fiber, which is regularly produced from human. Extensive experimental tests of various test specimens have been carried out in a laboratory. Several factors are considered, including the soil type, amount of cement, amount of fiber, fiber length, loading type, and curing age. The test results indicate that both the compressive and tensile strengths are significantly affected by the fiber, either increasing or decreasing depending on the conditions. The increase in tensile strength is significant in the sand-based soil cement due to the tensile resistance of the fiber which is interlocked with the surrounding soil or cement particles. The natural fiber provides a larger strain to failure due to its extensibility, which allows greater deformation. Based on the test results, natural hair fibers can be an effective and environmentally friendly way to improve soil ground subjected to tensile loading, such as an embankment slope, road subgrade, or landfill, thus reducing the cost for cement and waste treatment. The study results provide a useful information of better understanding the mechanical behavior of natural hair fiber in soil cement and the practical use of waste materials in civil engineering. The findings can be practically applied for improving earth structures under tensile loading.