• 한국안광학회지
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• 제20권1호
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• pp.35-42
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• 2015

목적: 콘택트렌즈 재질 및 렌즈에 침착된 단백질 종류에 따른 균의 흡착력을 비교하고 관리용품의 살균력 차이를 측정하고자 하였다. 방법: FDA 평가기준 및 방법인 Disinfection Efficacy Testing의 Part 2. Regimen Procedure For Disinfecting Regimens에 따라 균 흡착 및 관리용품의 살균력 측정실험을 실시하였다. 결과: 포도상구균을 제외한 녹농균, 세라티아균, 칸디다균은 etafilcon A 렌즈에 더 많이 흡착되었으며, 4종의 다목적용액은 칸디다균을 제외한 모든 균에서 거의 완벽한 살균력을 나타냈다. 눈물 단백질을 침착시킨 렌즈에서 세라티아를 제외한 모든 균은 알부민 침착 렌즈에서의 흡착이 많았으며, 다목적용액의 살균력은 라이소자임 침착 렌즈에 흡착된 균보다 알부민 침착 렌즈에 흡착된 균에서 높은 것으로 나타났다. 또한, 균의 종류에 따라 다목적 용액의 살균력이 달랐다. 결론: 균의 종류, 콘택트렌즈 재질, 침착된 눈물 단백질의 종류가 콘택트렌즈에 흡착되는 균의 양에 영향을 주며, 눈물 단백질의 침착은 다목적용액에 의한 살균력에 변화를 초래할 수 있음을 밝혔다. 이러한 살균력에 영향을 주는 요인에 의해 콘택트렌즈 위생상태가 달라지며 부작용 발생 여부가 영향을 받을 수 있음을 제안한다.

• 한국환경과학회지
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• 제15권7호
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• pp.677-688
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• 2006

Currently, the application of $TiO_2$ photocatalyst has been focused on purification and treatment of wastewater. However, the use of conventional $TiO_2$ slurry photocatalyst results in disadvantage of stirring during the reaction and of separation after the reaction. And the usage of artificial UV lamp has made the cost of photocatalyst treatment system high. Consequently, we studied that solar light/$TiO_2$ film system was designed and developed in order to examine disinfection characteristics of sewage wastewater treatment. The optimum conditions for disinfection such as solar light intensity, characteristic of sewage wastewater, amounts of $TiO_2$ and comparison of solar ligth/$TiO_2$ systems with UV light/$TiO_2$ system was examined. The results are as follows: (1) photocatalytic disinfection process with solar light in the presence of $TiO_2$ film more effectively killed total coliform (TC) than solar light or $TiO_2$ film absorption only. (2) The survival ratio of TC and residual ratio of organic material (BOD, CODcr) decreased with remain resistant material. (3) The survival ratio of TC and residual ratio of organic material (BOD, CODcr) decreased with the increase of amounts of $TiO_2$. (4) TC survival ratio decreased linearly with increasing UV light intensity. (5) The disinfection effect of solar light/$TiO_2$ slurry system decreased more than UV light/$TiO_2$ film systems. (6) The disinfection reaction followed first-order kinetics. We suggest that solar light instead of using artificial UV light was conducted to investigate the applicability of alternative energy source in the disinfection of TC and the degradation of organic material.

• 한국환경보건학회지
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• 제39권2호
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• pp.187-195
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• 2013

Objectives: For the practical application of the dielectric barrier discharge plasma reactor, a plasma reactor able to manage large volumes of water is needed. This study investigated the possibility of the practical application of a multi-plasma reactor which is a scaled-up version of a single plasma reactor. Methods: The multi-plasma reactor consists of several high-voltage transformers and plasma modules (discharge, ground electrodes and quartz dielectric tubes). The effects of water characteristics such as voltage (30-120 V), air flow rate (1-5 l/min), number of high-voltage transformers and plasma modules, and water quality on Escherichia coli (E. coli) disinfection and decrease of COD and $UV_{254}$ absorbance were investigated. Results: The experimental results showed that at a voltage of over 80 V, most of the E. coli were disinfected within 90 seconds. E. coli inactivation was not affected by the air flow rate. E. coli disinfection in the multiplasma process showed the traditional log-linear form of the disinfection curve. E. coli inactivation performance by transformer 3-Reactor 5 and transformer 3-Reactor 3 were similar. The disinfection performance of the UV process was affected by artificial sewage water. However, the plasma process was less affected by the artificial sewage within the standards for effluent water quality. Conclusions: Disinfection performance with several low voltages and plasma modules of three to five in number applied to the plasma process was higher than that concentrating a small amount of high voltage through a single plasma reactor. Removal of COD, $UV_{254}$ absorbance, and E. coli disinfection with the plasma process were better than with the UV process.

• 한국농공학회논문집
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• 제62권4호
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• pp.87-97
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• 2020

The livestock infections had been happened seasonally, but they have gradually changed to be irrelevant to seasons and have an aspect to rapidly spread after outbreak. Especially in Korea, proactive disinfection measures are very important because the livestock farms are located densely so high as to accelerate the spread of disease between farms. livestock disease outbreaks like HPAI and FMD occurred with high probability due to vehicles visiting the farms, this study is to evaluate the efficiency of livestock vehicle disinfection systems by investigating the disinfectant coverage according to the type of vehicle disinfection system and the type of vehicle quantitatively. In field experiments, water-sensitive papers (WSPs) were attached to 21 locations on the surface of four vehicles (sedan, SUV, truck, and feed transport), respectively, and exposed to disinfectants while the vehicle was sprayed in two vehicle disinfection systems (tunnel type and simplified type). The WSPs were scanned and image-processed to calculate the disinfectant coverage. The results showed that the tunnel-type vehicle disinfection system had a better disinfection performance with an average coverage of 90.27% for all vehicles compared to 32.62% of the simplified type system. The problem of the simplified system was a wide coefficient of variation (1.05-1.31) of the disinfectant coverage between 21 locations indicating a need for further improvement of nozzle location and arrangement.

• Environmental Analysis Health and Toxicology
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• 제16권1호
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• pp.1-8
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• 2001

The main purpose of applying the chlorination process during water treatment is for disinfection. Research results, however, indicate that disinfection by-products including trihalomethanes, haloacetic acids, haloacetonitriles, haloketones, and chloropicrin can be produced by chlorination process. Some of these disinfection by-products are known to be potential human carcinogens. This three-year project is designed to establish a standard analysis procedure for disinfection by-products in drinking water and investigate the distribution and sources of specific disinfection by-products. The occurrence level of DBPs in drinking water was below 50$\mu\textrm{g}$/L in most cases. THMs in plant effluent accounted for 48% of all DBPs measured, whereas HAAs accounted for 24%, HANs 14%, haloketones 5%, chloral hydrate 7%, and chloropicrin 2%. Chloroform was found to be the major THMs compound (71%), followed by bromodichloromethane (21%), dibro-mochloromethane (7%), and bromoform (3%), The concentration of DBPs formed in distribution systems increased from those detected in plant effluent. Results would play an important role in exposure assessment as a part of the risk assessment process, and would give basic information for establishment of disinfection by-products reduction and management procedures.

• 한국환경과학회지
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• 제16권7호
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• pp.785-791
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• 2007

The current study evaluated the technical feasibility of the application of titanium dioxide ($TiO_{2}$) photo-catalytic air cleaners for the disinfection of bioaerosols present in indoor air. The evaluation included both laboratory and field tests and the tests of hydraulic diameter (HD) and lamp type (LT). Disinfection efficiency of photocatalytic oxidation (PCO) technique was estimated by survival ratio of bacteria or fungi calculated from the number of viable cells which form colonies on the nutrient agar plates. It was suggested that the reactor coating with $TiO_{2}$ did not enhance the adsorption of bioaerosols, and that the UV irradiation has certain extent of disinfection efficiency. The disinfection efficiency increased as HD decreased, most likely due to the decrease in the light intensity since the distance of the catalyst from the light source increased when increasing the HD. It was further suggested that the mass transfer effects were not as important as the light intensity effects on the PCO disinfection efficiency of bioaerosols. Germicidal lamp was superior to the black lamp for the disinfection of airborne bacteria and fungi, which is supported by the finding that the disinfection efficiencies were higher when the germicidal lamp was used compared to the black lamp in the laboratory test. These findings, combined with operational attributes such as a low pressure drop across the reactor and ambient temperature operation, can make the PCO reactor a possible tool in the effort to improve indoor bioaerosol levels.

• 대한영양사협회학술지
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• 제10권1호
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• pp.34-46
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• 2004

The purpose of this study was to investigate disinfection state and effective factors of foodservice facilities and utilities of elementary schools in Busan area. Foodservice facilities and utilities investigated in this study were ceiling, wall, floor, trench, greasetrap, hood, pest and dumb waiter. The questionnaire which was administered to 196 dietitians was used as a survey method. The results were as follows. The washing method of foodservice facilities and utilities was mainly used by detergent washing-natural dry. The disinfection method of foodservice facilities and utilities was mainly sanitized by sodium hypochlorite. Dumb waiter and hood were sanitized by 70% ethyl alcohol and iodine. In washing and disinfection frequencies of foodservice facilities and utilities ceiling was twice/year, wall, hood and pest control facilities were once/week, floor, trench, greasetrap and dumb waiter were everyday, respectively. Floor, trench, greasetrap and dumb waiter were disinfected properly, whereas ceiling, wall, hood and pest were not disinfected properly. The washing method was related to dietitian's marital status and education. The disinfection state was related to dietitian's age and career, having of sanitation check list. The disinfection method was also affected dietitian's marital status, number of employee, duration of foodservice, number of total serving and having of sanitation check list. Therefore based on the results of this study, it should be given to the microbiological study on disinfection of facilities and utilities such as ceiling, wall, floor, trench, greasetrap, hood, pest and dumb waiter and the dietitian and employee's sanitation training also should be conducted continuously.

• 치과방사선
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• 제22권2호
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• pp.329-335
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• 1992

The purpose of the study was to determine whether Sodium hypochlorite and Glutaraldehyde would be effective for the surface disinfection of contaminated radiographic film pockets with saliva The following results were as obtained 1. Proper times for surface disinfection of 2.0% Glutaraldehyde and 3.5% Sodium hypochlorite were 60 seconds. 2. When films were immerged in 2% Glutaraldehyde solution for 1 minute, baterial colonies were present in 24 cases(80%). 3. When films were immerged in 3.5% Sodium hypochlorite solution for 1 minute, bacterial colony was absent in 25 cases(83.3%). 4. Differences of effectiveness on surface disinfection between 2% Glutaraldehyde and 3.5% Sodium hypochlorite were statistically significant.

• 한국환경과학회지
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• 제11권5호
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• pp.411-418
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• 2002

The current study evaluated the disinfection efficiency of free chlorine and chloramine for microorganisms on various pipe materials, such as copper, galvanized steel, carbon steel, and stainless steel. In addition, the effect of internal pipe corrosion and corrosion inhibitors on the bactericidal efficiency was evaluated using a simulated loop. For disinfection with a phosphate corrosion inhibitor, chloramination was found to be more effective than chlorination due to its persistence. Free chlorine disinfection was optimized with a high phosphoric acid concentration, while chloramine disinfection was optimized with a high phosphoric acid or low polyphosphate concentration. In simulated copper and galvanized steel loop tests, chloramination with phosphoric acid was demonstrated to be more effective.

• Environmental Engineering Research
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• 제14권2호
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• pp.126-133
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• 2009

This study investigated the removal characteristics of various micro organic compounds by low-pressure nanofiltration membranes comprised of disinfection by products and pharmaceutically active compounds. The experimental removal of micro organic compounds by low-pressure nanofiltration membranes was compared with the transport model calculations, which consist of diffusion and convection terms including steric hindrance factor. The selected molecule from the disinfection byproducts and pharmaceutical active compounds showed a much lower removal than polysac-charides with a similar molecular size. However,the difference between model calculation and experimental removal of disinfection by-products and pharmaceutically active compounds could be corrected. The correlation of Ks with solute radius was further considered to clarity transport phenomena of micro organic solutes through nanofiltration membranes.