• 제목/요약/키워드: Contaminated surface

검색결과 688건 처리시간 0.035초

환경에 따른 송전용 애자의 누설전류 분석 (Analyses of Leakage Current of Transmission Insulator as a Function of Environmental Condition)

  • 최인혁;이동일;김찬영
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.1166-1170
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    • 2004
  • The leakage currents of transmission insulator were investigated as a function of environmental conditions, such as temperature, humidity, and rainfall. The insulators were artificially contaminated with insoluble yellow soil and kaolin which helped salt to stick on the surface of insulator. The insulators contaminated with the grade of B, C, and D were installed in the KoChang Testing Center. The leakage currents were measured and compared with non-contaminated insulators. The results indicated that the most important factor affecting leakage current was humidity. After heavy rain, the artificially contaminated salt was dissolved, resulting in similar characteristics between with and without contamination

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Fundamental study on volume reduction of cesium contaminated soil by using magnetic force-assisted selection pipe

  • Nishimura, Ryosei;Akiyama, Yoko;Manabe, Yuichiro;Sato, Fuminobu
    • 한국초전도ㆍ저온공학회논문지
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    • 제23권3호
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    • pp.26-31
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    • 2021
  • Advanced classification of Cs contaminated soil by using a magnetic force-assisted selection pipe was investigated. A selection pipe is a device that sort particles depending on their particle size, based on the relationship between buoyancy, drag, and gravity force acting on the particles. Radioactive cesium is concentrated in small-particle size soil components with a large specific surface area. Hence, the volume of the Cs contaminated soil can be reduced by recycling the large-particle size soil components with low radioactive concentration. One of the problems of the selection pipe was that the radioactive concentration of the stayed soil in the selection pipe exceeds 8000 Bq/kg, which is the standard value of recycling of Cs contaminated soil, due to low classification accuracy. In this study, magnetic fields were applied to the lab-scale selection pipe from upper side to improve the classification accuracy and to reduce the radioactive concentration of the stayed soil.

질산성 질소로 오염된 소유역 하천 수질의 계절 변화 (Seasonal Variation of Surface Water Quality in a Catchment Contaminated by $NO_3-N$)

  • 김연태;우남칠;이광식;송윤구
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제10권2호
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    • pp.20-27
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    • 2005
  • 밀집된 축사의 영향으로 충적층 지하수가 질산성 질소로 심하게 오염되어 있는 소유역을 흐르는 화봉천 수질의 계절 변화를 연구하였다. 이 하천에서 축산폐수의 직접 유입이 확인되었으며, 오염된 지하수 유입으로 인한 수질 변화가 나타났다. 건기에는 축산폐수의 직접 유입이 하천수질에 큰 영향을 미치고 있다. 우기에는 강수에 의한 희석효과에도 불구하고 지표수의 질산성 질소 농도가 오히려 증가하였으며, 질산성 질소로 오염된 지하수 유입량 증가가 큰 영향을 미친 것으로 판단된다. 지하수의 하천 유출은 산소, 수소 동위원소 조성을 이용하여 증명하였다. 질산성 질소 농도는 화봉천이 청미천보다 상대적으로 높으므로, 화봉천 유업에 의해 청미천의 질산성 질소 농도가 증가되고 있으며, 하천수의 질산성 질소 농도가 높아지는 우기에 이러한 수질 영향이 더욱 커졌다.

Application of Response Surface Methodology for optimize the Biostimulant ball and stabilize Heavy metals pollutants in contaminated coastal sediments

  • Song, Young-chae;Subha, Bakthacachallam;Woo, Jung Hui
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2015년도 춘계학술대회
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    • pp.179-180
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    • 2015
  • The variety of organic and inorganic pollutants are introduced to coastal sediment and making highly contaminated due to rapid development of industralization and economic development. Numerous contaminants are release into marine sediment and it significantly affect marine aquatic environment. In the present study stated the optimize the biostimulant ball (BSB) in coastal sedimentand stabilse the heavy metals present in the sediment. The effective variables like BSB size, distance and month variables on Cu stabilization was determined by using Response surface methodology(RSM). The analysis of variance (ANOVA) and coefficient determination (R2) of Cu reduction 0.9610 and maximum stabilisation was obtained in 3cm ball size and 5.5cm distance and 4 month interval time. This result revealed that the BSB in effective for Cu reduction in coastal sediment.

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Employing Response Surface Methodology for optimization of slow release Biostimulant ball in contaminated coastal sediments in Busan, South Korea

  • Song, Young-Chae;Subha, Bakthacachallam;Woo, Jung Hui
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2014년도 추계학술대회
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    • pp.87-88
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    • 2014
  • The Coastal sediment is highly contaminated due to ship transportation, industries discharges and urban sources. Various contaminants release into seawater and settle in marine sediment and it significantly affect marine eco system. In the present study evaluated the optimization of slow release biostimulant ball (BSB) in coastal sediment in busan. The effective variables like BSB size, distance and month variables on VS reduction was determined by using Response surface methodology(RSM). The analysis of variance (ANOVA) and coefficient determination (R2) of VS was 0.9369 and maximum reduction of VS was obtained in 3cm ball size and 5.5cm distance and 4 month interval time. This result revealed that the BSB in effective VS reduction in coastal sediment.

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코로나 바이러스 확산억제를 위한 환경 및 건축마감재료 고찰 - 항바이러스 재료 관련 해외 문헌을 중심으로 (Review of Environmental Characteristics and Building Finishes Controlling the Spread of SARS-CoV-2 - Focused on overseas literature related to antiviral experiments)

  • 박용현;이현진;권순정
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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    • 제29권4호
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    • pp.37-44
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    • 2023
  • Purpose: Currently, research on environmental conditions and finishing materials for medical facilities with proven antiviral performance is poor in Korea. Through this study, we have explored environmental characteristics and finishing materials that can be used to control cross-infection when constructing medical facilities. Methods: Experiments in overseas papers related to antiviral effects of environmental conditions, spatial compartments, and interior finishes have been analyzed. Results: The higher the temperature, the higher the humidity, and the higher the illuminance of sunlight, the lower the viability of the corona-virus. The proliferation of viruses was suppressed on the surface of the copper alloy. Materials such as brushed steel are the ones that maintain the strongest viability. Among the characteristics of the surface, survival and propagation power differ depending on whether it is porous or hydrophilic. In the case of infection ward actually operated in Italy, the presence of airborne viruses in contaminated and non-contaminated spaces differed significantly. Corona-virus has been identified in reachable parts such as door handles and medical shelves in quasi-contaminated spaces, which are spaces between contaminated and non-contaminated spaces, but the corona-virus has not been identified in cases of out-of-touch walls. Implications: It is necessary to evaluate the performance by testing the construction finishing materials of infection control facilities according to domestic conditions.

어패류에 오염된 장염비브리오균(Vibrio parahemolyticus)에 대한 차아염소산수의 살균효과 (Bactericidal Effects of Hypochlorous Acid Water against Vibrio parahaemolyticus Contaminated on Raw Fish and Shellfish)

  • 김희연;최진경;신일식
    • 한국식품과학회지
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    • 제47권6호
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    • pp.719-724
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    • 2015
  • 넙치, 방어 어류 2종과 가리비, 참굴 패류 2종에 수산식품의 주요 식중독균인 장염비브리오균(V. parahaemolyticus)을 인위적으로 오염시킨 후, 강산성차아염소산수와 미산성차아염소산수의 살균효과를 조사한 결과를 요약하면 다음과 같다. 넙치에 장염비브리오균을 인위적으로 오염시킨 후, 강산성차아염소산수 및 미산성차아염소산수 공히 10배의 양으로 세정한 결과, 약 4.0 log가 감소하였으며, 30배의 양으로 세정한 경우, 검출한계 이하로 나타나 강력한 살균효과가 있는 것을 확인하였으며 방어에 있어서도 넙치와 비슷한 결과를 확인하였다. 가리비에 장염비브리오균을 인위적으로 오염시킨 후, 강산성차아염소산수 및 미산성차아염소산수 공히 10배의 양으로 세정한 결과, 약 4.2 log가 감소하였으며, 30배의 양으로 세정한 경우에는 장염비브리오균이 검출되지 않아 강력한 살균효과를 나타내었다. 참굴에 장염비브리오균을 인위적으로 오염시킨 후, 강산성차아염소산수 및 미산성차아염소산수 공히 10배의 양으로 세정한 결과, 약 3.8 log가 감소하였으며, 30배의 양으로 세정한 경우, 7.0 log가 감소하여, 강력한 살균효과가 있는 것을 확인하였지만 넙치, 방어, 가리비에 비해서는 살균효과가 다소 낮게 나타났다. 어류 근육이나 가리비에 비해 참굴에 오염된 장염비브리오균에 대한 차아염소산수의 살균효과가 다소 떨어지는 것은 참굴의 표면 구조의 복잡성 때문인 것으로 판단된다.

NOAA/AVHRR 주간 자료로부터 지면 자료 추출을 위한 구름 탐지 알고리즘 개발 (Development of Cloud Detection Algorithm for Extracting the Cloud-free Land Surface from Daytime NOAA/AVHRR Data)

  • 서명석;이동규
    • 대한원격탐사학회지
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    • 제15권3호
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    • pp.239-251
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    • 1999
  • The elimination process of cloud-contaminated pixels is one of important steps before obtaining the accurate parameters of land and ocean surface from AVHRR imagery. We developed a 6step threshold method to detect the cloud-contaminated pixels from NOAA-14/AVHRR datime imagery over land using different combination of channels. This algorithm has two phases : the first is to make a cloud-free characteristic data of land surface using compositing techniques from channel 1 and 5 imagery and a dynamic threshold of brightness temperature, and the second is to identify the each pixel as a cloud-free or cloudy one through 4-step threshold tests. The merits of this method are its simplicity in input data and automation in determining threshold values. The threshold of infrared data is calculated through the combination of brightness temperature of land surface obtained from AVHRR imagery, spatial variance of them and temporal variance of observed land surface temperature. The method detected the could-comtaminated pixels successfully embedded inthe NOAA-14/AVHRR daytime imagery for the August 1 to November 30, 1996 and March 1 to July 30, 1997. This method was evaluated through the comparison with ground-based cloud observations and with the enhanced visible and infrared imagery.