• 제목/요약/키워드: Contamination factor

검색결과 332건 처리시간 0.026초

세척과 절연보강에 따른 고압전동기 고정자 권선의 절연상태 분석 (Analysis of Insulation Condition in High Voltage Motor Stator Windings Following Cleaning and Insulation Reinforcement)

  • 김희동
    • 한국전기전자재료학회논문지
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    • 제25권6호
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    • pp.474-480
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    • 2012
  • Diagnostic tests were performed on two high voltage(HV) motor stator windings. These tests included the measurement of insulation resistance, polarization index, AC current, dissipation factor($tan{\delta}$) and partial discharge(PD) magnitude. Surface contamination of HV motor stator windings has an effect on the AC current and $tan{\delta}$. When the stator windings were finished cleaning and insulation reinforcement, the increase rate of AC current(${\Delta}I$) and dissipation factor(${\Delta}tan{\delta}$) were very small compared to those before cleaning. However, the PD magnitude remained the same. These tests show that cleaning and insulation reinforcement of HV motor stator windings can reduce the insulation failure.

광주지역 일곡 매립지 주변에서의 하천수 및 지하수 오염 모니터링 (Monitoring of Stream water and Groundwater Contamination at the Ilgok landfull Site in kwangju, Korea)

  • 차종문
    • 자원환경지질
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    • 제32권5호
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    • pp.485-493
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    • 1999
  • In order to dermine the degree of contamination for the Ilgok landfill site, stream water, groundwater and stream sediment samples were collected in 1998 and 1999, and analyzed for physico-chemical properties. The stream water contains significanr concentrations of TDS $HCO_3^-$and $NO_3^-$, and ground-water is polluted by $NO_3^-$ up to the drinking water standard from landfill leachate. From the point of the horizontal movement of elements, stream water IL-2 at the conjunction point with landfill leachate reached the most high concentrations of $HCO_3^-,Cl^-,Na^+, K^+, NO_3^-,Mg{^2+}$ and $SO_4^{2-}$stream water Il-3 shows the high concentrations of $Ca^{2+}, Pb^{2+}$ and $Mg^{2+}$. The optimum contamination indicator of Ilgok landfill site is $HCO_3^-, C^l-, Na^+, Mn^{2+}$ and TDS from the calculation of contamination factor.

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의치상 수리면 오염원에 따른 수지의 결합강도 (Bond strength of denture base resin repaired according to contamination)

  • 정경풍
    • 대한치과기공학회지
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    • 제25권1호
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    • pp.71-79
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    • 2003
  • The purpose of this study was to investigate bond strength of denture base resin repaired according to contamination. One commercial denture base resin and two different kinds of relines resin were tested; Lusiton 199(denture base resin), Vertex(reline resin) and TokusoRebase(repair resin). The specimens were processed according to the manufacturer's instructions to cured denture base resin(polymethylmethacrylate; PMMA) and reline resin. Bond strengths were examined by use of a three-point transverse flexural strength test. Data were analyzed with two-factor analysis of variance and Duncan's post-hoc test at $\alpha$=0.05. Generally, the bondstrength of heat-cured resin(Lusiton 199) was higher than the other resins. The contaminations produced an decrease in bond strength. Therefore the contamination, such as saliva or water must be avoided during the laboratory repair procedures.

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소규모 돼지도축공정에서 도체오염 미생물의 변화 (Microbial change of pork carcass during processing in small size slaughterhouse)

  • 홍종해;이경환;이성모
    • 한국동물위생학회지
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    • 제25권1호
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    • pp.31-37
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    • 2002
  • Major hazards existed in slaughterhouse are pathogenic microorganisms originated from intestinal microflora of slaughtered animals. This study was intended for the identification of microbial contamination sources during pork slaughtering in small plants. Total aerobic bacteria, Coliform group, Salmonella spp, Listeria monocytogenes, and Campylobacter jejuni/coli were isolated from the surface sample of pork carcasses. Contamination level among different sampling points of ham, belly and neck did not showed statistical differences. Therefore, the mixed sampling from belly and neck of carcass could be effective for microbiological monitoring. Isolation rates of pathogenic microorganisms showed Salmonella spp 20.9%, Listeria monocytogenes 10.5%, and Campylobacter jejuni/coli 8.1% from 296 sampling points. High prevalence rate of Salmonella spp indicated that the contamination of intestinal microflora occurred due to unsanitary processing control, which required HACCP system in small plants. It was recommended that the prerequisite program should be a key factor for a successful HACCP system implementation especially in small size slaughterhouse.

GIS 및 계층분석법을 이용한 지하수 오염 취약성 평가 및 관리 우선 대상 지역 평가 (An Assessment of Groundwater Contamination Vulnerability and Priority Areas for Groundwater Management Using GIS and Analytic Hierarchy Process)

  • 이명진;현윤정;황상일
    • 한국지리정보학회지
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    • 제18권3호
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    • pp.35-51
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    • 2015
  • 본 연구는 기존의 지하수 오염 취약성 평가 방법을 개선하고, 연구지역에 적용하여 보다 정량적인 지하수 오염 취약성 분석을 기반으로 지하수 관리 우선 대상 지역을 선정하는 것이다. 이를 위하여 첫째, 기존의 '잠재오염' 중심의 지하수 오염 취약성 평가 방법을 오염을 완화시키는 '대응 능력'을 고려한 방법론으로 개선하였다. 둘째, 계층분석 방법(AHP)과 지하수 전문가의 설문을 바탕으로 지하수 오염 취약성 평가 인자의 가중치를 산정하였다. 셋째, 광역지자체(경기도)를 연구지역으로 선정하고 개선된 방법론 및 가중치를 GIS로 구현하여 실제 지하수 오염 취약성 평가를 수행하였다. 넷째, 정량적 지하수 오염 취약성 평가도를 바탕으로 지하수 오염 관리 우선 대상 지역을 선정하였다. 본 연구에서 개선된 지하수 오염 취약성 평가 세부 평가인자는 총 15개 이며, 이에 대한 AHP를 활용한 가중치의 산정결과에서 기존의 '잠재오염'에 해당하는 평가인자 보다 신규로 개선된 '대응능력'이 높은 가중치로 분석되었다. 또한 GIS를 활용한 경기도 지역의 지하수 오염 취약성 평가 결과 서울에 인접한 고양시 및 광명시 등이 지하수 오염 취약성이 높았으며, 포천시 및 양평군이 상대적으로 취약성이 낮은 것으로 분석되었다. 본 연구에서는 기존의 지하수 오염 취약성 평가를 개선하였고 실제 연구지역에 적용하였다. 본 연구의 결과는 향후 국가 및 지자체 차원의 지하수 관리 기본계획에 직간접적으로 활용이 가능할 것으로 판단된다.

HACCP 적용을 위한 도계처리 공정내 미생물 오염의 분석 (Analysis of Microbial Contamination in Poultry Slaughtering Operations for the Application of HACCP)

  • 홍종해;권혁무;고주언
    • 한국환경보건학회지
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    • 제22권1호
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    • pp.45-50
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    • 1996
  • The application of HACCP system, which was adopted by Codex Alimentarius Committee for the safe meat and poultry production, is one of the urgent task for competing in the world trade markets. But there have been no useful analytical studies to identify the causes of contamination in the poultry meat processing plants in Korea. This study was conducted to investigate the potential hazards during the operations by the microbiological examination for the poultry meat processing plant (20,000 birds capacity a day) located in Kangwon province. In spite of air contamination of work places, it may not directly affect the surface contamination of poultry meats. But the risk of Campylobacter jejuni/coli contamination was high. The number of total count was decreased about ten times, but remarkable changes of microbial contamination could not be recognized in each procedure during the operations. The washing water was already contaminated as much as $10^{3-6}CFU/ml$ in SPC before the operations. It means that to keep water tanks hygienic is a primary step to prevent the occurrences of microbial contamination. The overflow and recirculation of water in scalding, washing, and chilling was aslo an important factor for a hygienic control. Based on this study, the followings could be regarded as an important factors for hygenic control in the poultry slaughtering plants on a small scale. The temperature of water used for scalding should be constantly maintained on a required temperature, and the overflow rate of 1~1.5 liter per bird. The carcass surface and the body cavity should be washed thoroughly and the cross-contamination due to facilities, workers, and tools should be prevented. The chilling water sholud be maintained under 5$\circ$C of temperature with ice and overflow, and residual chlorine level of 50 ppm.

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중학교 일학년 학생에서 모즐리 강박척도를 이용한 탐색적 요인 분석 (Exploratory Factor Analysis of the Maudsley Obsessive-Compulsive Inventory in Middle School Students)

  • 박경혜;김효원;김진영;정인원
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • 제22권2호
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    • pp.89-94
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    • 2011
  • Objectives : The purpose of this study was to assess the factor structures related to the Maudsley Obsessive-Compulsive Inventory (MOCI) in middle school students. Methods : A total of 1,175 7th grade students from four middle schools in Paju city completed the MOCI, Center for Epidemiological Studies-Depression scale (CES-D), and Self Esteem Scale (SES). An exploratory factor (maximum likelihood method with oblique rotation) and correlation analyses were subsequently performed. Results : The two main factors related to the MOCI were 'intrusive thought' and 'contamination'. 'Intrusive thought' was positively correlated with the CES-D and negatively associated with the SES. 'Contamination' had a negative correlation with self-esteem as measured by the SES. Conclusion : The results of this study revealed a two-factor structure of obsessive and compulsive symptoms in middle school students.

유리앰플 주사제 개봉방법이 유리조각 혼입 및 약물오염에 미치는 영향 (Influence of Different Methods of Cutting Ampules on Drug Contamination by Glass Flakes from the Ampule)

  • 정현철;전미양
    • 기본간호학회지
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    • 제16권2호
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    • pp.207-213
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    • 2009
  • Purpose: This study was done to examine how medication contamination in a single-dose glass ampule is affected by minute glass flakes generated in different methods of cutting the ampule. Method: Sixty medication-containing glass ampules were randomly assigned to two groups. The number of glass flakes, resulting from two different cutting methods (with cotton and without cotton), were counted under the microscope. Contamination was evaluated by extracted the medication with a syringe and culturing it in E. coli, coliform, and aerobic bacteria culture media. Result: Fewer glass flakes were found in the ampules when the ampule was cut with cotton. The use of cotton, however, did not significantly change the degree of drug contamination. Conclusion: Although minute glass flakes generated in the ampule cutting operation did not significantly contaminate the medication and the use of cotton decreased the number of glass flakes in the ampules, glass flakes injected into the blood and tissues of the patient remain a risk factor. Therefore, pre-filled syringes or syringes with filters would be alternative methods and safeguards against the possible injection of glass flakes generated while cutting the ampule.

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Determination of Bioconcentration Factor of Heavy Metal (loid)s in Rice Grown on Soils Vulnerable to Heavy Metal (loid)s Contamination

  • Lee, Seul;Kang, Dae-Won;Yoo, Ji-Hyock;Park, Sang-Won;Oh, Kyeong-Seok;Lee, Jin-Ho;Cho, Il Kyu;Moon, Byeong-Churl;Kim, Won-Il
    • 한국토양비료학회지
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    • 제50권2호
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    • pp.106-114
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    • 2017
  • There is an increasing concern over heavy metal(loid) contamination of soil in agricultural areas including paddy soils. This study was conducted to determine the bioconcentration factor (BCF) for heavy metal(loid)s to brown rice grown in paddy soils vulnerable to heavy metal(loid)s contamination, for the quantitative health risk assessment to the residents living nearby the metal contaminated regions. The samples were collected from 98 sites nationwide in the year 2015. The mean and range BCF values of As, Cd, Cu, Ni, Pb, and Zn in brown rice were 0.027 (0.001 ~ 0.224), 0.143 (0.001 ~ 2.434), 0.165 (0.039 ~ 0.819), 0.028 (0.005 ~ 0.187), 0.006 (0.001 ~ 0.048), and 0.355 (0.113 ~ 1.263), respectively, with Zn showing the highest. Even though the relationship between heavy metal(loid) contents in the vulnerable soils and metal contents in brown rice collected at the same fields was not significantly correlated, the relationship between log contents of heavy metal(loid)s in the vulnerable soils and BCF of brown rice wes significantly correlated with As, Cd, Cu, and Zn in rice. In conclusion, soil environmental risk assessment for crop uptake should consider the bioconcentration factor calculated using both the initial and vulnerable heavy metal(loid) contents in the required soil and the crop cultivated in the same fields.

도심지역 인공호의 수질관리를 위한 지표세균에 관한 연구 (A Study on Indicator Bacteria for Water Quality Management of Urban Artificial Lakes)

  • 추덕성;권혁구;이상은;이장훈
    • 한국환경보건학회지
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    • 제33권4호
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    • pp.299-305
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    • 2007
  • Distribution of fecal pollution indicator bacteria and environmental parameter were investigated of urban artificial lakes. An average concentration of temperature, pH, SS, DO, $COD_{Mn}$, T-P, T-N, Turbidity, Chl-a were $21.5^{\circ}C$, 8.07, 116.70 mg/l, 8.66 mg/l, 2.24 mg/1, 0.52 mg/l, 1.71mg/l, 80.54 NTU, and 52.12 mg/l respectively. From the results of bivariate correlation analysis, fecal contamination indicator bacteria were found to be mutually correlated. And turbidity and suspended solid were correlated. From the results of principal component analysis, four factors were extracted. And four factors of variance explained up to 81.5 percentage. Factor 1 was pollution pattern by fecal contamination, factor 2 was physical pollution pattern by pollution source, factor 3 was natural pollution by precipitation, and factor 4 was artificial pollution pattern by organism.