• 제목/요약/키워드: Silt

검색결과 970건 처리시간 0.029초

도로 재비산먼지 이동측정차량을 이용한 도로 재비산먼지 측정과 도로먼지 미량원소 분석 (Road Dust Emissions from Paved Roads Measured by Road Dust Monitoring Vehicle and Analysis of Trace Elements)

  • 이명훈;신정섭;신원근;이상구;김종;이창
    • 한국입자에어로졸학회지
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    • 제8권2호
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    • pp.47-54
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    • 2012
  • Paved road dust emissions were investigated 14 times on 12 main roads in Seo-Cho Gu, Seoul, Korea by vehicle-based mobile sampling system(Road Dust Monitoring System) during September to December 2011. Also, fourteen heavy metals present in the dust samples were analyzed by ICP. ICP analysis showed that one of major source of the road dust would be urban construction. A large amount of silt was found, which might be originated mainly from building construction and open beds of trees. Trace element and pollution indices of heavy metals(Cd, Cu, Ni, Pb, Zn) on the roads adjacent to the commercial area had higher concentrations than those on the roads adjacent to the construction and residential areas because of traffic density and heavy traffic.

해저 연약지반 보강 조건에 따른 인공어초 침하 거동에 대한 실험적 연구 (An Experimental Study of Settlement Behavior of Artificial Reef according to Reinforcement Characteristics)

  • 윤대호;김윤태
    • 한국지반신소재학회논문집
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    • 제16권1호
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    • pp.53-61
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    • 2017
  • 바다 자원의 조성을 위해 시설되는 인공어초는 해저 연약지반에 설치될 경우 침하 및 세굴에 의한 기능 상실이 발생할 수 있다. 따라서 본 연구에서는 해저 연약지반의 보강에 따른 인공어초의 침하 거동을 알아보기 위해 모래, 실트 및 점토 지반을 각각 조성하여 관입실험, 침하실험 등과 같은 다양한 실내실험을 수행하였다. 무보강(unreinforced), 지오그리드(geogrid) 보강 및 하이브리드 대나무매트(hybrid bamboo mat, HBM) 보강과 같은 3종류의 보강과 보강재의 면적에 따른 특성을 살펴보았다. 실험 결과 보강재의 면적이 증가할수록 보강 효과가 증가하는 경향을 보였으며, HBM이 지오그리드 단일 보강에 비해 더 뛰어난 보강 효과를 보였다.

전복, Nordotis discus 의 호흡과 폐사에 미치는 부니의영향 (Effects of Silt and Clay on Respiration and Mortality of the Abalone, Nordotis discus)

  • 정의영;신윤경;이주하
    • 한국패류학회지
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    • 제9권2호
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    • pp.23-29
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    • 1993
  • 전복, Nordotis discus의 1$0^{\circ}C$와 2$0^{\circ}C$의 수온구에서 개체크기별 대사와 폐사에 미치는 부니의 영향에 대한 결과는 다음과 같다.1. 수온 -염분별 산소소비율의 일반적 경향은 고온-고염분에서 큰개체보다는 작은개체에서 그 비율리 높게 나타났다.2. 염분별 두 수온간의 온도계수 (Q $_{10)}$ 는 작은 개체에서 1.2-2.9의 병위를 큰개체의 경우 1.5-3.4의 범위를 나타내었으나 개체크기에 관계없이 유사한 양상을 보였다.3. 부니의 농도별 사망율은 작은 개체의 경우 처리 96시간후 2$0^{\circ}C$수온에서 부니 농도1000ppm에서 가장 높았고. 큰 개체의 경우 50ppm에서 가장 낮았다.4. 96시간-반치사농도(LC$_{50}$)는 1$0^{\circ}C$의 경우, 큰개체에서 1076.58 ppm, 작은 개체에서 812.55 ppm이었으며, 2$0^{\circ}C$의 경우는 큰개체에서 698.28 ppm, 작은 개체에서 546.74ppm으로 나타났다.5. 부니의 영향으로 인한 호흡산소소비량은 개체크기에 관계없이 1$0^{\circ}C$에서 보다 2$0^{\circ}C$에서 더욱 높았으며, 1000ppm에서 70% 이상의 감소율을 나타내었다.

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금강형 소나무림에 있어서 토양의 이화학적 성질 (Physicochemical Properties of Soil in Pine (Pinus densiflora for. erecta Uyeki) Forests)

  • 주성현;정성철
    • Current Research on Agriculture and Life Sciences
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    • 제19권
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    • pp.31-37
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    • 2001
  • Uyeki(1928) classified Pinus densiflora into six ecotypes(Northeastem type, Middle-southern flat type, middle-southern upland type, Wibong type, Ankang type, and Geumgang type) based on the pine tree type. The bark color of Geumgang type was ash-brown color on the lower parts of stem and yellowed color on the upper parts of stem. We investigated the physicochemical properties of soil forests to obtain basic data for preservation of exellent pine (Pinus densiflora for. erecta Uyeki). The results were as follows; The soil texture of the Pinus densiflora for. erecta Uyeki forests were showed nearly as sandy loam, that is, sand, silt and clay were consisted of 72%, 15% and 13%, respectively. Soil acidity(pH 4.6) was lower than Korea average forest soil acidity(pH 5.2). The average contents of available phosphate was 11.7ppm at Sokwang-ri, 26.8ppm at Mt. Eungbong, 24.2ppm at Mt. Kumma. It was the lowest at Uljin(4.6ppm). The contents of carbon was 6.2% at Mt. Chungok, 6.1% at Mt. Eungbong. This value was more than average of Korea forest soil.

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천안.원주 불량매립지의 수리지질 및 수리지구화학 비교

  • 이진용;윤희성;이성순;천정용;권형표;김종호;김창균;박정구
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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    • pp.394-397
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    • 2006
  • Hydrogeologic and hydrochemlcat conditions of two uncontrolled landfills without reliable underlying liners, leachate collection and treatment systems were compared. With similar weather conditions, spatial distribution and temporal variations of contaminants of concern and redox parameters were different for the two landfills. These differences are highly associated with ages and hydrogeologic settings of the landfills. Groundwater flow diverges from the Cheonan landfill while it converges to downgradient area in the Wonju landfill. Less permeable clayey silt layer or silty soil in the subsurface limited dispersion of leachate plume in the former landfill but highly permeable sandy soil with good lateral extent facilitated rapid plume dispersion in the latter landfill. In addition, hydraulic properties of the cover soil played a role in the different development of redox conditions, which resulted in significantly different concentrations of nitrates. Most problematic contaminants at downgradient wells of the landfills are ammonia and nitrate.

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황색종 담배 (Nicotiana tabacum L.)의 토양중 유효인산의 이용과 그 평가 방법 (UTILIZATION AND EVALUATION Of AVAILABLE PHOSPHORUS IN SOILS FOR FLUE-CURD TOBACCO (NICOTIANA TABACUM L.) II. FIELD EXPERIMENT)

  • 박수준;최정
    • 한국연초학회지
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    • 제6권2호
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    • pp.155-168
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    • 1984
  • Field test were conducted to select the best method for soil phosphorus test and to obtain the critical levels of each method for P fertilizer recommendations based on tobacco production. Truog method was recognized to be the mort suitable one for soil P test. N. Carolina, Bray No.1 and Olsen methods were followed in order. Bray No. 2 and Lancaster methods showed the least satisfaction. The critical levels of available P by lancaster, Bray No. 1, N. Carolina,01sen, and Truog methods were 55ppm, 32ppm, 21ppm, 19ppm, and 22ppm, respectively. Below the critical level a large yield response can be expected with 10kg $P_2O_5$/10a, above critical level little or no response is expected. In soils the more the initial available p, the more available P was carried over, while the more the total amount of silt and clay, the less the residual P was found. The increase in residual P by 10kg of $P_2O_5$ was greater than that of 5kg/10a. The chemical composition and the price of the cured leaf were not affected by the $P_2O_5$ application, indicating that the increase in the rate of $P_2O_5$ application would not exert on the quality of tobacco.

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토양 세정법을 이용한 실제 유류 오염 토양 및 지하수 정화

  • 강현민;이민희;정상용;강동환
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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    • pp.418-421
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    • 2003
  • Surfactant enhanced in-situ soil flushing was peformed to remediate the soil and groundwater at an oil contaminated site, and the effluent solution was treated by the chemical treatment process including DAF(Dissolved Air Flotation). A section from the contaminated site(4.5m$\times$4.5m$\times$6.0m) was selected for the research, which was composed of heterogeneous sandy and silt-sandy soils with average Hydraulic conductivity of 2.0$\times$10$^{-4}$ cm/sec. Two percent of sorbitan monooleate(POE 20) and 0.07% of iso-prophyl alcohol were mixed for the surfactant solution and 3 pore volumes of surfactant solution were injected to remove oil from the contaminant section. Four injection wells and two extraction wells were built in the section to flush surfactant solution. Water samples taken from extraction wells and the storage tank were analyzed by GC(gas-chromatography) for TPH concentration with different time. Five pore volumes of solution were extracted while TPH concentration in soil and groundwater at the section were below the Waste Water Discharge Limit(WWDL). Total 18.5kg of oil (TPH) was removed from the section. The concentration of heavy metals in the effluent solution also increased with the increase of TPH concentration, suggesting that the surfactant enhanced in-situ flushing be available to remove not only oil but heavy metals from contaminated sites. Results suggest that in-situ soil flushing and chemical treatment process including DAF could be a successful process to remediate contaminated sites distributed in Korea.

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청계천 홍수량, 유사량 특성 분석 (Analysis of flood and sediment discharge characteristics on Cheonggyecheon)

  • 유철상;김기욱;김경준;박용희;이지호;박현근;김대하;박상형;박창열;김병수;김현준
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2007년도 학술발표회 논문집
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    • pp.1849-1853
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    • 2007
  • In this study, flow-sediment discharge characteristics and relationships are estimated for the Cheonggyecheon basin, newly restored in 2005. Flow and sediment discharge measurement is performed on Ogansugyo, Majanggyo 2 and Yongdugyo during the rainy seasons in 2005-2006. The parameters of Clark UH are estimated using measured data, and sediment rating curves are derived by using grading and concentration analysis. Concentration time and storage coefficient of Clark UH are estimated 0.5 hr and 0.63 hr for Majanggyo 2, and 0.4 hr and 0.45 hr for Yongdugyo, respectively. Grain size of sediments are composed of fine silt to fine sand (0.008-0.25mm) based on the sediment grain size classification (Lane, 1947). Flow-sediment relationships derived by using concentration analysis shows that sediment discharge has no obvious relationship with flow discharge.

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비포화대 오염정화 설계를 위한 공압파쇄 모사 해석 (A Numerical Analysis on Pneumatic Fracturing for in-situ Remediation)

  • 권미선;박은규;이철효;김용성;김남진
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제15권6호
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    • pp.53-63
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    • 2010
  • Pneumatic fracturing is an emerging tool to enhance the remediation efficiency of contaminated unsaturated zones by injecting high pressure air and inducing artificial fracture networks. Pneumatic fracturing is reported to be well suited for the cases where the contaminated unsaturated zone thickness is less than 5 m as many contaminated domestic sites in Korea. Nevertheless, there have been almost no studies carried out on the site-specific efficiency and the optimized design of pneumatic fracturing considering the unsaturated zone characteristics of Korea. In this study, we employ numerical simulations to compare the efficiency of pneumatic fracturing on the aspect of the site remediation and the porosity improvement at several hypothetic unsaturated zones composed of four typical soil types. According to the simulation results, it is found that the zone with fine grains soil such as clay and silt shows better efficiency than the zone composed of coarse grains in terms of air flow and porosity enhancements. The results imply that pneumatic fracturing may improve the efficiency of site reclamation by jointly or independently applied to the many contaminated sites in Korea.

인삼근부병에 관한 연구 3 (Studies on the Root Rot of Ginseng(III))

  • 이민웅
    • 미생물학회지
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    • 제12권4호
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    • pp.153-158
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    • 1974
  • Around and in the area of Wolgot-Muon, Gimpo-Gun, Kyunggi province, I examined total bacteria, general Pseudomonas spp., fluorescent Pseudomonas spp., in soil layers and also in different kinds of soil of respective diseased, uncultivated, and healthy areas, and found the followings. 1. In the diseased and uncultivated areas, the content of moisture and silt was greater than in the healthy area. 2. Contrary to the above, the healthy area contained a greater amount of inorganic elements such as $P_2O_5$, K, Ca and of soil particle such as Cs and Fs. The degree of pH and content of Mg were even in three types of soils. 3. Total bacteria were found in abundance in the healthy soil. It was observed that in all types of areas, bacteria reside in abundance in the rhizosphere, i.e., 10-15 cm layers and that the closer the surface, the greater the numbers of the bacteria. 4. General Pseudomonas spp. were also found to the greater in number on the surface of the soil, especially so in the rhizosphere, with the numbers decreasing as the soil layers increase. Numbers of this bacteria in all types of area were nearly uniform. 5. A great number of fluorescent Pseudomonas spp. were found in the diseased area, especially so in the rhizosphere.

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