• 환경위생공학
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• 제5권1호
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• pp.73-82
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• 1990

This study was conducted to investigate the vibrio sap contamination of aquarium (water) in Incheon Area The results obtained were as follows : 1. V. parahaemolyticus was detected 20.4% at samples of aquarium water and not detected at underground water 2. V. unlnificus was not detected at all samples 3. Underground water was similar to aquarium water on pH and the concentration of salt 4. Underground water proved it's safety bacteriologically 5. V. parahaemolyticus was common in the sea water between July to October.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.169-172
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• 1995

Establishment of a diagnosing technology for the deterioration of reinforced concrete structures due to salt contamination is urgent, but few analytical methods based on measured data obtained from concrete structures have been presented so far. Chloride penetration into concrete from sea water is generally understood and analysed as diffusion of chloride ion. This paper presents a new method of predicting chloride penetration into concrete based on diffusion theory. Also, it determines the duralility of Marine structure in service with the prediction of remaiing lifetime by the carvonation test.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2004년도 학술발표회
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• pp.77-89
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• 2004

A computer model is developed to assess optimal ground water pumping rates and optimal locations of wells in a coastal region. A sharp interface model is used to simulate the freshwater and salt water flows. Drawdown, upconing, saltwater intrusion and the contamination of well are considered in this model. A genetic algorithm with parallel processing is used to identify the optimal solution.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1476-1477
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• 2007

동일한 오손환경에서 자기재, EPDM, 실리콘 alloy 등의 현수애자에 흐르는 누설전류 변화를 관찰하여 오손과의 상관성을 규명하였다. 고창실증시험장에 신품과 경년품의 배전설비를 전주와 동일한 높이의 구조물에 설치하여 2006년 5월1일부터 11일 1일까지 약 6개월 동안의 누설전류를 측정하여 분석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.262-264
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• 2002

This paper shows the design standard of KEPCO on the contamination design for 345 kV and 154 kV transmission tower. Up to now, because the design standard of KEPCO on the insulation design contains 154 kV transmission system only, we had investigated the 343 kV system for the revision of design standard, with respect to the contamination design, we have used the same design philosophy which were adopted to the 765 kV transmission tower. In order to determine the number of insulator discs, we had investigated the withstand voltage of discs according to the level of ESDD(Equivalent Salt Deposit Density) and kinds of disc types. The TOV(Power Frequency Temporary Overvoltage) were estimated by EMTP(Electromagnetic Transient Program) for both 154 kV and 345 kV transmission system. The overvoltage level was appeared 1.35 p.u. between phase to ground for both 154 kV and 345 kV transmission system, but finally this factor was not applied to the design standard considering current design standard and economic point of view. With regard to classification of contamination area of 345 kV transmission system, we added the clean area which was not specified in the current design practise.

• 자원환경지질
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• 제34권2호
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• pp.175-192
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• 2001

동해안 울진 지역 천부 지하수의 수리지구화학 자료에 대하여 지구통계 분석(이원배치 분산 분석, 군집 분석, 요인 분석)을 수행함으로써, 수질 자료와 오염 특성의 시간적.공간적 변화 양상을 규명하고 대수층에서 일어나는 주요 반응을 고찰하였다. 이원배치 분산 분석 결과, 광역적 수질 특성은 8개 수계분지를 따라 유의한 공간적 변화를 보여주지 않았으나, Ca, HCO$_3$,SO$_4$등 일부 이온종은 수계분지별로 의미 있는 변화를 나타내었다. 시료 채취시기에 따른 계절 변화는 SO$_4$를 제외하고는 인지되지 않았다. 그러나 군집 분석 결과, 수리지구화학 특성의 변화는 해안으로부터의 거리에 따라 아주 잘 설명될 수 있음을 지시하였다. 요인 분석 결과, 연구 지역 천부 지하수의 수리지구화학 특성은 다양한 요인에 의해 지배됨을 확인하였다. 중요 순서로 그 요인을 나열하면, 1) 물-암석 반응(주로 탄산염 광물의 용해), 2) 바다에서 기원한 해염의 혼입, 3) 비료와 각종 농화학 약품에 의한 오염으로 밝혀졌다.

• 한국식품위생안전성학회지
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• 제21권4호
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• pp.263-268
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• 2006

본 연구는 비가열 즉석섭취식품 중 과채가공품인 샐러드, 조림류와 양념젓갈류의 오염도를 조사하기 위하여 백화점, 대형할인매장 등에서 유통중인 샐러드 25개, 조림류 11개, 젓갈류 7개 등 총 43개 제품을 대상으로 총호기성균, 대장균군, E. coli의 미생물 오염도를 조사하였다. 총호기성균의 오염수준은 샐러드 $4.56\sim7.45\;log_{10}CFU/g$, 조림류(수산물조림) $2.43\sim7.03\;log_{10}CFU/g$, 젓갈류(양념젓간) $4.51\sim6.71\;log_{10}CFU/g$을 나타내었다. 대장균군의 오염수준은 샐러드 $4.00\sim6.66\;log_{10}CFU/g$, 조림류 $1.70\sim5.20\;log_{10}CFU/g$, 젓갈류(양념젓갈) $2.50\sim4.42\;log_{10}CFU/g$였다. E. coli의 오염수준은 조림류와 전갈류에서는 검출되지 않았고, 샐러드에서는 25개중 8개 시료(32%)에서 검출되었으며, 그 수준은 $0\sim3.58\;log_{10}CFU/g$였다. 샐러드에서 완포장 제품과 즉석포장제품은 미생물오염도에 별다른 차이를 보이지 않았다. 결론적으로 시중에서 판매되고 있는 샐러드 및 조림류, 젓갈류의 위생상태는 좋지 않은 것으로 판단된다. 그래서 식품의 제조단계에서는 원료의 세척 및 살균을 철저히 하고 유통단계에서는 냉장온도 관리를 철저히 하며, 최종 판매단계에 이르기까지 안전을 위한 총체적인 관리방안의 수립이 필요할 것이다.

• 치위생과학회지
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• 제18권5호
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• pp.296-304
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• 2018

The purpose of this study was to propose a method for the effective management of toothbrush contamination. Toothbrush microbial contamination was analyzed according to the duration of toothbrush use, frequency of toothbrush use per day, and toothbrush storage location. We also analyzed the microbial reduction effect of vinegar, antimicrobial mouth rinse, bamboo salt, and baking soda, which are sterilization materials that can be easily used every day. We collected 45 toothbrushes from university dormitories from May to June 2018. To determine the degree of microbiological contamination with general bacteria, coliform bacteria, and Staphylococcus aureus, bristle samples were cultured at $36^{\circ}C$ for 24 hours using 3M$^{TM}$ Petrifilm plates and then measured based on Petrifilm evaluation criteria. Toothbrush microorganisms were analyzed according to the duration of use, frequency of use per day, storage location, and effect of each sterilization material. General bacteria, coliforms, and S. aureus contamination increased with frequency and duration of use (p<0.05). In particular, S. aureus showed a statistically significant increase to 36.15 CFU/ml after 1 month, 504.23 CFU/ml after 2 months, and 2,386.67 CFU/ml after 3 months (p<0.05). We found that 1% vinegar was the most effective substance for reducing general bacteria, coliforms, and S. aureus. In addition, 1% antimicrobial mouth rinse solution applied for 5 minutes was the most effective in reducing S. aureus. It is crucial to recognize the importance of toothbrush care and store toothbrushes in a dry place and replace them periodically. We recommend use of vinegar and antimicrobial mouth rinse solution to disinfect toothbrushes. These should be applied as a 1% solution for at least 1 minute. Proper care of toothbrushes is important in maintaining oral health as well as overall health. Instructions on toothbrush care should be given when teaching children or adults how to brush teeth.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권1호
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• pp.39-45
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• 2002

To determine the representative pollution degree of outdoor insulators during the drought season, we should make an investigation on the long-term accumulation characteristics of contaminants. As the contamination mechanism of outdoor insulator is extremely depend on the climatic condition, there is a large difference between the research result of Japanese utilities. So based on the difference of precipitation of the Korea and Japan, we could say that the accumulation characteristics of the countries have a significant difference. But, based on the result of Japan, the accumulation property of contaminants was ignored in KEPCO\`s specification. So, to determine the accumulation characteristics of Korea, we measured the 2 and 3 month ESDD with brush wiping method and make a statistical analysis on measured data. And, from the results, we understood the accumulation characteristics of Korea and the influence of topographical condition on the distribution characteristics of salt contaminants. coast.

• Journal of Electrical Engineering and Technology
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• 제11권4호
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• pp.961-968
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• 2016

The non-uniform distribution of contamination on insulator surface has appreciable effects on flashover voltage, and corresponding researches are valuable for the better selection of outdoor insulation. In this paper, two typical types of porcelain and glass insulators which are widely used in ac lines were taken as the research subjects, and their corrections of AC flashover voltage under non-uniform pollution were studied. Besides, their flashover characteristics under different ratio (T/B) of top to bottom surface salt deposit density (SDD) were investigated, including the analysis of flashover voltage, surface pollution layer conductivity and critical leakage current. Test results gave the modified formulas for predicting flashover voltage of the two samples, which can be directly applied in the transmission line design. Also, the analysis delivered that, the basic reason why the flashover voltage increases with the decrease of T/B, is due to the decrease of equivalent surface conductivity of the whole surface and the decrease of critical leakage current. This research will be of certain value in providing references for outdoor insulation selection, as well as in proposing more information for revealing pollution flashover mechanism.