• Title/Summary/Keyword: 오염(contamination)

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Effect of metal impurity contamination on silicon wafer and solar cell properties (금속 불순물 오염에 따른 실리콘 기판 및 태양전지 특성의존성 분석)

  • Baek, Sang-Hun;Lee, Jeong-Cheol;Cho, Jun-Sik;Wang, Jin-Seok;Song, Jin-Soo
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.167-167
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    • 2009
  • 결정질실리콘 태양전지를 제조함에 있어 실리콘 기판 내의 금속 불순물들은 소자제작 시에 성능 저하의 원인으로 작용한다. 따라서 본 연구에서는 실리콘 기판에 Cr, Cu, Ni 불순물을 강제 오염시킨 후 태양전지를 제작하여 각각의 불순물에 대한 특성을 조사 하였다. p-type 실리콘 기판을 오염시키기 위해 일정 시간동안 표준용액에 담근 후 질소 분위기에서 열처리 하여 불순물을 확산시켰다. 이후 상용 공정을 이용하여 태양전지를 제작하고 기판내 금속불순물 농도에 따른 태양전지의 동작특성을 분석하였다.

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Assessment of Toxic Effects in Aquatic Environment and the Fish Cytochrome P450 1A(CYP1A) Gene (수서 환경독성 평가와 어류 Cytochrome P450 1A (CYP1A) 유전자)

  • 윤석주;김일찬;윤용달;이재성
    • Korean Journal of Environmental Biology
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    • v.21 no.1
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    • pp.1-7
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    • 2003
  • The CYP1A gene is one of Cytochrome P450 drug-metabolizing enzymes with dose-dependant manner of gene expression and is useful to get the information of alterations on gene expression upon environmental contaminants as well as the biomarker of environmental contamination at the specific places. In this report, we further discuss the usefulness of CYP1A gene in relation to aquatic environmental contamination at several aspects.

Remote Control of Pumping System for Underground Water Pollution and Running Dry Prevention Using Ubiquitous (유비쿼터스를 이용한 지하수 오염과 고갈방지를 위한 펌핑시스템의 원격제어)

  • Tack, Han Ho
    • Journal of Korea Society of Industrial Information Systems
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    • v.18 no.3
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    • pp.9-15
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    • 2013
  • This paper was development of remote controller of pumping system by using ubiquitous for underground water contamination prevention in the area of glasshouse facility. This paper automatically controls from to temperature and humidity for pumping sprinkler at water hanging cultivation. This prevents indiscreetive development of underground water, and prevents damage of environmental pollution without complementary measures in case of water lacked humble-void. The result of this research, confirms decrease of electrical fee, prevention of indiscreet underground water usage and its drying up thought optimum farm products management and pumping control system.

A Study on Isolation of Mixed Heavy Metal-Contaminated Soil and the Waste in Railroad Workshop (철도 정비창의 폐기물과 혼합된 중금속 오염토 분리에 관한 연구)

  • Son, Woohwa;Lee, Seungho
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.12
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    • pp.59-66
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    • 2012
  • In this study, it was sampling from heavy metal-contaminated soil with the waste in railroad workshop. And, the pollution concentration and analysis of particle-size distribution were conducted to design efficient purification process that it was aimed at high contaminated area, low contaminated area and samples containing waste foundry sand. But, it was the other signs of general soil contamination, as construction waste of waste concrete and waste wood, waste foundry sand, incinerator ash, etc is overall buried on the grounds. Thus, the common heavy metal purification technology has not decreased the pollution. However, heavy-metal contamination was reduced by magnetic separation utilizing the magnetic component of the mixed waste.

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

  • Jeong, Hyeon-Cheol;Jeon, Mi-Yang
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.16 no.2
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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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Comparison of Bacterial Contamination according to the Using Period of Feeding Bag and Disinfection Methods in Neurosurgery Intensive Care Unit Patients (신경외과중환자의 간헐적 비위관 경장영양 시 경장영양백 사용기간 및 소독방법에 따른 오염도 비교)

  • Kim, Hyun-Ju
    • Journal of Korean Biological Nursing Science
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    • v.13 no.3
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    • pp.204-210
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    • 2011
  • Purpose: The purpose of this study was to provide basic data for the guidelines for cleaning the feeding bags by comparing the level of contamination according to cleaning and disinfection methods when feeding tube of Neurosurgery Intensive Care Unit patients. Methods: This study was a true-experimental study, with 48 cases in total. The feeding bag of 48 patients were randomly assigned to detergent cleaning method or disinfectant decontamination method. The period of the experiment was January to July 2008, and enteral nutrition was given within 30 minutes for 2 hours, 4 times a day at 7AM, noon, 5PM, and 9PM for seven days. Feeding bags were cleaned after each feeding according to the assigned cleaning and disinfection method followed by microbial cultures on 4th and 8th day before the 7AM feeding. Results: After three and seven days of feeding and cleaning, the level of contamination was significantly lower when bags were cleaned with disinfectant than cleaning with detergent and tepid water. Conclusion: In cases where feeding bags are reused, for example, intensive care unit and home care settings, study findings indicate that cleaning bags with disinfectant is an effective way to prevent contamination of bags.

Method of Particle Contamination Control for Yield Enhancement in the Cleanroom (클린룸 제조공정에서 수율개선을 위한 입자오염제어 방법)

  • Noh, Kwang-Chul;Lee, Hyeon-Cheol;Kim, Dae-Young;Oh, Myung-Do
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.6 s.261
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    • pp.522-530
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    • 2007
  • The practical studies on the method of particle contamination control for yield enhancement in the cleanroom were carried out. The method of the contamination control was proposed, which are composed of data collection, data analysis, improvement action, verification, and implement control. The partition check method and the composition analysis for data collection and data analysis were respectively used in the main board and the cellular phone module production lines. And these methods were evaluated by the variation of yield loss between before and after improvement action. In case that the partition check method was applied, the critical process step was selected and yield loss reduction through improvement actions was observed. While in case that the composition analysis was applied, the critical sources were selected and yield loss reduction through improvement actions was also investigated. From these results, it is concluded that the partition check and the composition analysis are effective solutions for particle contamination control in the cleanroom production lines.

A Comparison between the Contamination Level of Uniforms and the Nasal Staphylococcus aureus Colonization before and after the Clinical Practice of Nursing Students (간호대학생의 실습 전후 실습복 오염도 및 비강내 황색포도알균 집락정도 비교)

  • Park, Jin Hee;Shin, Gisoo;Kim, Jiyoung
    • Journal of Korean Biological Nursing Science
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    • v.16 no.2
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    • pp.90-97
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    • 2014
  • Purpose: The purpose of this study was to compare the contamination level of uniforms with nasal colonization of Staphylococcus aureus before and after the clinical practice of nursing students. Methods: This study was a survey research, conducting microbial culture by smearing the front surface and the pockets of uniforms, and the nasal cavity both before and after clinical practice on 70 nursing students. For the analysis, descriptive statistics, chi-square test, paired t-test were used for statistical analysis using SPSS 19.0. Results: The contamination level of uniforms increased more significantly after clinical practice on the front surface (p=.008) and pockets (p=.031) than before clinical practice, and Staphylococcus aureus, and Enterobacter aerogenes were detected. Conclusion: Through the results above, it is believed that it is reasonable to do the laundering of clinical uniforms of nursing students once a week. Because it is possible to disseminate disease germs with the contamination of clinical practice uniforms in a hospital environment, it is necessary to offer education for the laundering of uniforms with appropriate management.

Contamination Characteristics of Agricultural Groundwater Around Livestock Burial Areas in Korea (가축매몰지 주변 농업지역 지하수의 수질오염 특성 분석)

  • Kim, Hyun Koo;Park, Sun Hwa;Kim, Moon Su;Kim, Hye Jin;Lee, Min Kyeong;Lee, Gyeong-Mi;Kim, So-Hyun;Yang, Jae-Ha;Kim, Tae Seung
    • The Journal of Engineering Geology
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    • v.24 no.2
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    • pp.237-246
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    • 2014
  • Seasonal variations of major contaminants in groundwater around livestock burial areas in Gyeonggi province, Korea, were examined. Seven typical contamination indicators ($NO_3$-N, $NH_3$-N, chloride, pH, DO, ORP, and EC) were monitored in groundwater samples collected from 84 wells located within 60 m of livestock burial sites for the leachate plume emanating from the livestock burial sites. The monitoring results of pH, DO, ORP, and EC revealed minimal seasonal variations, providing no evidence for leachate plumes. The $NO_3$-N concentrations were below 30 mg/L and exhibited minimal seasonal fluctuations, even in the wells located close to (< 20 m) the burial sites; the $NH_3$-N and chloride concentrations also showed similar results. The contamination indicators examined in this study indicate that the observed groundwater contamination is primarily from preexisting pervasive contamination due to agricultural activities and livestock farming, not leachates derived from nearby livestock burial sites.