• 제목/요약/키워드: Contaminated air

검색결과 325건 처리시간 0.035초

장시간사용(長時間使用)한 공조용(空調用) 전기집진(電氣集塵)필터의 특성(特性) (Characteristics of long-term operated Electrostatic airclean filter for air-conditioner)

  • 홍영기;강광옥;이성화;손상철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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    • pp.453-455
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    • 1995
  • In electrostatic airclean filter, the collection efficiency defends on particle charge in the ionizer section. The effect of electrostatic airclean filter condition (deposition of dust, variation of corona discharge current) on corona discharge characteristics was well studied. However, it seems not to be studied on corona discharge characteristics of electrostatic airclean filter respect to contaminated electrode which is caused by practical use. In this paper, Long-term(60days) effects are studied experimentally by two methods. The one is ozone concentration, the other is collection efficiency. Generation of ozone level was increased but collection efficiency was slightly reduced in long-term used electrostatic airclean filter.

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The importance of assessing heavy metals in medicinal herbs: a quantitative study

  • Behera, Bhagyashree;Bhattacharya, Sanjib
    • 셀메드
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    • 제6권1호
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    • pp.3.1-3.4
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    • 2016
  • Consumption of herbal products from the medicinal plants contaminated with heavy metals can cause serious consequences on human health. This is a major concern for traditional and herbal medicine. The present study was carried out to analyze and quantify the levels of six potentially toxic heavy metals namely arsenic, lead, cadmium, mercury, chromium and nickel in ten important Indian medicinal herbs. The air dried raw herbs were processed by microwave assisted wet digestion and analyzed by using atomic absorption spectrophotometer equipped with graphite tube atomizer. Except the chromium content in three plants, all the levels of six heavy metals analyzed were found to be quite below the permissible limits in all the ten raw medicinal herbs analyzed. The present work implies that, regular and systematic screening of raw medicinal herbs is necessary to check the levels of the heavy metal contaminants before using them for consumption or preparation of herbal formulations so that the possible contamination cannot cumulate up to the finished products.

제철공정중 오염물질 제어를 위한 BAT (BAT(Best Available Technique) for Control of Contaminated Materials in Steel Works)

  • 임채현;김효진;김영진;고동준
    • 한국대기환경학회:학술대회논문집
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    • 한국대기환경학회 2003년도 추계학술대회 논문집
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    • pp.491-492
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    • 2003
  • 최근 국제적으로는 2005년 대기배출허용기준 강화와 총량규제 도입추진, 대기 배출부과금 제도의 강화 움직임, 대기환경규제지역의 규제지역 확대에 따른 굴뚝자동측정기 부착의무화, VOCs(휘발성유기화합물) 물질 배출원 관리가 강화되는등 환경적 이슈가 점점 높아지고 있는 추세이다. 또 외부적으로 기후변화협약에 따른 온실가스 규제와 스톡홀름협약에 따른 POPs물질(잔류성유기오염물질)규제가 예상되며 이에 따라 국내 환경부에서도 05년까지 오염물질 배출농도 강화와 POPs 물질 inventory 구축작업과 소각로 이외의 다이옥신 배출원에 대한 다이옥신규제 대상시설이 확대될 전망이다. (중략)

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공회전속도 조절용 스텝모터가 AT차량의 급발진 현상에 미치는 영향 (Some Effects on AT Vehicle's Sudden Acceleration due to Stepping Motor for Compensation of Idle Speed)

  • 김종일;차정연;손정배
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집B
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    • pp.879-885
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    • 2000
  • This study is carried out to make clear the reason of occurrence of sudden acceleration incident of AT vehicle. The stepping motor is used to control the engine speed at idle by compensating the volume of air. By the way it's valve is contaminated by blow-by gas, deposit and back fire etc. This contamination could occur the load of motor at low temperature. This plays an important role in damaging the motor's coil with the motor's performance interfered. If it's coil is damaged the ISC could malfunction. If these phenomena occur, the speed of engine may increase or the engine may stall with hunting.

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불포화 토양내에서 가스상 오존 이동특성에 대한 Multiphase liquids의 영향

  • 정해룡;최희철
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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    • pp.124-127
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    • 2003
  • Laboratory scale experiments on in-situ ozonation were carried out to delineate the effects of liquid phases, such as soil water and nonaqeous phase liquid (NAPL) on the transport of gaseous ozone in unsaturated soil. Soil water enhanced the transport of ozone due to water film effect, which prevent direct reaction between soil particles and gaseous ozone, and increased water content reduced the breakthrough time of ozone because of increased average linear velocity of ozone and decreased air-water interface area. Diesel fuel as NAPL also played a similar role with water film, so the breakthrough time of ozone in diesel-contaminated soil was significantly reduced compared with uncontaminated soil. However, ozone breakthrough time was retarded with increased diesel concentration, because of high reactivity of diesel fuel with ozone. In multiphase liquid system of unsaturated soil, the ozone transport was mainly Influenced by nonwetting fluid, diesel fuel in this study.

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Identification of Aspergillus nidulans from cooked eggs produced by permitted factory

  • Park, Hye-Won;Kim, Kook-Joo;Youk, Ji-Hea;Woo, Jong-Tae
    • 한국동물위생학회지
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    • 제30권2호
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    • pp.283-286
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    • 2007
  • Fungus generally doesn't produce toxic or harmful substances so it has low chances to cause food poisoning. However it leads to change appearance, odor and characteristics of the contaminated foods and result in sanitary risk problems. Therefore the contamination of fungi should be prevented since they are not proper for human consumption. Green fungi with white outline raised from the air cell of cooked eggs which were collected by Gyeongi Livestock Veterinary Service in August, 2006. The results came out after the cultivation using Sabouraud's Dextrose Agar(SDA). The conidium appeared white and monospore, the shape of colony was round and oval. Conidiophore was brown and granulated and wrinkles and formed. It was confirmed as Aspergillus nidulans based on the dying using Lactophenol cotton blue, the observation of septum and vesicle from the grown spores, and rDNA sequencing.

The hydrocarbon concentration distribution in the contaminated site using geospatial analysis

  • Lee, Ju-Young;Yang, Jung-Seok;Choi, Jae-Young;Krishinamurshy, Ganeshi
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2007년도 학술발표회 논문집
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    • pp.909-910
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    • 2007
  • The volatile organic compounds exposure is governed by the source distance and dispersion of the pollutant into air and groundwater. The purpose of this study was to validate suggested models for the prediction of concentration distributions. The study design was organized into different methods to simulate industry site. The distribution models generally showed a fair agreement with measured data. For graphical representation of concentration of volatile hydrocarbon, it has to obtain a continuous representation of the contamination of the site. Therefore, the used interpolative methods examined for this project are the IDW(inverse Distance Weighting) and kriging method. In the results, in summary, all two different methods can be used to quantify exposures at a particular source area, and thus provide, a solid foundation for making risk-based decisions. All the calculations can be performed using Excel's built-in functions, and the capabilities of geospatial analysis allow the results to be displayed visually. However, anyone who uses these methods should understand all of the assumptions and limitation.

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휘발성 유기화합물이 포함된 폐기물의 안전성에 관한 연구 (A Study for Safety on the Waste Contaminated with VOCs)

  • 황태준;양성봉;김선
    • 한국대기환경학회:학술대회논문집
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    • 한국대기환경학회 1999년도 추계학술대회 논문집
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    • pp.285-286
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    • 1999
  • 최근 유기성 폐기물을 이용하여 제2의 에너지원으로 재활용하는 업체들이 국내에서도 점점 늘어나고 있는 추세에 있다. 이들 회사들은 각종 폐기물들을 수집ㆍ처리 방법에 따라 다소 차이가 있지만 대부분은 일본 및 유럽 등 선진국들에서 재처리 및 활용기술을 도입하여 얻어진 제품들을 연료 등의 제2의 에너지원으로 사용하고 있다. 그러나 이들 대부분의 업체들은 원료로 사용되는 유기성폐기물들의 수거 및 저장 그리고 나아가서 제품의 보관 및 운송과정에서 상당히 문제점들을 노출 시키고 있음을 알 수 있다.(중략)

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매몰지주변 기저유출 관리 필요성 (Needs for the Management of Baseflow in the Vicinity of Burial Sites)

  • 김영준;정우혁;김건하
    • 상하수도학회지
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    • 제31권3호
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    • pp.219-228
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    • 2017
  • Burial sites are constructed for the purpose of controlling air-born livestock diseases such as avian influenza and foot-and-mouth outbreak. As most of the burial sites are located in the agricultural land use, public concerns are mounting about soil and groundwater contamination. During precipitation events, contaminated baseflows are released from the burial sites into surface waters. Baseflow are therefore required to be managed properly, by monitoring and even by remediation means. We propose each burial sites should be regarded as a point source possibly degrade groundwater, thus be managed in watershed scale for the purpose of surface water quality conservation.

원격지 단체급식을 위한 포장용 도시락 생산설비의 최적화 연구 (Optimization of the Korean Packaged Meal (Dosirak) Production Facilities for Food Service Delivered Long Distance)

  • 박형우;고하영;박노현;강통삼;모수미
    • 한국식생활문화학회지
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    • 제3권1호
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    • pp.89-93
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    • 1988
  • 국내 도시락 공장을 조사 분석하여 대량생산에 적합토록 그 문제점을 보완 개선했다. 특히 식품위생법과 건축법상의 공장허가 사항을 고려해서 3가지 면적별로 모델 도시락 공장을 설계하였다. 작업장은 하나의 개방공간에 배치된 기기류를 오염지역, 준청결지역, 청결지역으로 나누어 작업중의 2차오염 문제를 배제시켰고, 기기류는 밥급속냉각기, 냉장고 겸 냉각기를 설치하여 위생안전성을 부여했으며, 청결실에 멸균(집진)기를 설치하여 완제품의 초기 미생물 농도를 줄이고 2차오염 요인을 제거함으로써 위생적인 도시락 생산유통이 가능한 도시락 생산공장을 설계하였다.

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