• Journal of Conservation Science
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• v.30 no.2
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• pp.137-148
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• 2014

Large scale anoxic chamber system(volume $28m^3$) was developed and installed at The National Folk Museum of Korea for the first time in Korea. In order to get optimal anoxic treatment condition, we compared the disinfection of adults, larvae and eggs of cigarette beetles using nitrogen and argon. The time for complete disinfection of cigarette beetles in pine wooden blocks exposed to nitrogen at oxygen concentration 0.01% and 50% in relative humidity were 15 days at $20^{\circ}C$, 10 days at $25^{\circ}C$, and 7 days $30^{\circ}C$. Time were 10 days at $20^{\circ}C$, 7 days at $25^{\circ}C$, and 5 days $30^{\circ}C$ in argon anoxic atmosphere. From the mortality of cigarette beetles, optimal disinfection condition was oxygen concentration 0.01%, $25^{\circ}C$ in temperature, 50% in relative humidity and exposure time 21 days at nitrogen atmosphere. And when large scale anoxic chamber system was supplied nitrogen by nitrogen generator for anoxic treatment of many collections or large collections, it could be operated stably. To verify optimal disinfection condition, museum insects(adults, larvae, pupae and eggs of cigarette beetles in pine wooden blocks, cotton fabrics and Korean paper book, adults and larvae of drugstore beetles in pine wooden blocks, cotton fabrics and Korean paper book, larvae of varied carpet beetles in pine wooden block and silk fabrics, adults and larvae of hide beetles and adults of rice weevils in breeding boxes) which exposed at optimal disinfection condition, were completely killed.

• Korean Journal of Veterinary Research
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• v.59 no.2
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• pp.101-104
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• 2019

This study examined the disinfection conditions (exposure time, 0-30 min; exposure temperature, $4^{\circ}C-65^{\circ}C$) of hypochlorous acid water (HOCl) in automobile disinfection equipment. The study tested poliovirus type 1 (PV1), low pathogenic avian influenza virus (AIV, H9N2), and foot and mouth disease virus (FMDV, O type). As a result, the PV1 and FMD viruses were inactivated easily (virus titer 4 log value) by HOCl (> 100 ppm) but the AIV required higher exposure temperatures (> $55^{\circ}C$). In conclusion, the exposure temperature and time are important factors in deactivating AIV and FMDV.

• Journal of Environmental Science International
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• v.19 no.7
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• pp.889-900
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• 2010

The experimental design and response surface methodology (RSM) have been applied to the investigation of the electro-UV complex process for the disinfection of E. coli in the water. The disinfection reactions of electro-UV process were mathematically described as a function of parameters power ($X_1$), NaCl dosage ($X_2$), initial pH ($X_3$) and disinfection time ($X_4$) being modeled by use of the Box-Behnken technique. The application of RSM using the Box-Behnken technique yielded the following regression equation, which is an empirical relationship between the residual E. coli number and test variables in actual variables: Ln (CFU) = 23.57 - 0.87 power - 1.87 NaCl dosage - 2.13 pH - 2.84 time - 0.09 power time - 0.07 NaCl dosage pH + 0.14 pH time + 0.03 $power^2$ + 0.47 NaCl $dosage^2$ + 0.20 $pH^2$+ 0.33 $time^2$. The model predictions agreed well with the experimentally observed result ($R^2$ = 0.9987). Graphical response surface and contour plots were used to locate the optimum point. The estimated ridge of maximum response and optimal conditions for the E. coli disinfection using canonical analysis was Ln 1.06 CFU (power, 15.40 W; NaCl dosage, 1.95 g/L, pH, 5.94 and time, 4.67 min). To confirm this optimum condition, the obtained number of the residual E. coli after three additional experiments were Ln 1.05, 1.10 and Ln 1.12. These values were within range of 0.62 (95% PI low)~1.50 (95% PI high), which indicated that conforming the reproducibility of the model.

• Korean journal of aerospace and environmental medicine
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• v.30 no.3
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• pp.91-94
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• 2020

The coronavirus infectious disease-19 (COVID-19) pandemic has had a profound impact on the aviation industry. In order to overcome this crisis, airlines have made their efforts in various fields. Therefore, we tried to summarize these efforts of airlines. It is also essential to keep aircraft that have been in landing for a long time in optimal condition. In this paper, we tried to find out about efforts to maintain landing aircraft and maintenance of personnel. Through such constant care, airlines will be able to quickly respond to increasing aviation demand when the infectious disease situation is stabilized in the future. Finally, airlines and passengers must make several efforts to ensure that passengers are free from COVID-19 while traveling by air. These include general precautions to prevent infection, separation of airline personnel and passengers, changes in seat assignments and in-flight services, periodic aircraft disinfection, and prevention of in-flight infections.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.675-681
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• 2011

In this paper, we dealt with the design and fabrication of a medium pressure ultra-violet (UV) lamp and a magnetic ballast which are main components for ballast water treatment systems (BWTS). To acquire an optimal discharge condition of UV lamp, electrical and optical characteristics depending on the argon gas volume and the amount of mercury were experimentally analyzed. Rated voltage, current and power consumption of a prototype lamp were 490 [V], 8.6 [A] and 4.0 [kW], respectively. UV intensity of the lamp was 15 [%] higher than that of an equivalent lamp which is used in a BWTS. The magnetic ballast was designed in a UI core type through theoretical analysis and simulation. The open voltage and the rated power consumption of the ballast were 920 [V] and 8.5 [kVA] respectively. The disinfection efficacy which is carried out in a BWTS equipped with the UV lamp and magnetic ballast was over 99.99 [%], and this satisfy the IMO regulations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1204-1210
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• 2014

New control methods are proposed for indoor air quality by removing fine airborne dust-particles. As suspended fine dust-particles contain inorganic dust as well as fine organic bacteria, studies for simultaneous control of these contaminants are required. In this study, photocatalytic disinfection of indoor suspended microorganisms such as E. coli and Bacillus subtilis is performed by three types of photocatalysts with UVA irradiation. The UVA irradiation strength was controlled to the minimum $3{\mu}W/cm^2$, and ZnO, $TiO_2$, and ZnO/Laponite ball were used as the catalysts. The results indicate that E. coli was removed over 80 % after about 2 hours of reaction with UVA and all three types of photocatalysts, whereas only with UVA, around 50 % E. coli removal was obtained. Among the catalysts, ZnO/Laponite composite ball was found to have similar sterilizing capacity to $TiO_2$. However, in case of B. subtilis, which has thick cell wall in its spore state, disinfection was not effective under the low UVA irradiation condition, even with the catalysts. Further studies need to figure out the optimal UVA irradiation ranges as well as photocatalysts doses to control airborne dust, to provide healthy clean air environment.

• Analytical Science and Technology
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• v.8 no.1
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• pp.91-99
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• 1995

One of alternative conventional technologies used for treatment of livestock wastes is composting process, and recently some mechanical composting processes are being practiced. It is, however, recognized the composting process also has its own limitations such as longer time requirement, and difficulties to estimate the degree of decomposition, etc. The incomplete compost contains potentially harmful materials to crops and public health due to instabilized organic contents and pathogenic organisms. The purpose of this investigation is to develop an innovative system whereby anxious livestock wastes are thoroughly stabilized and disinfected. Thus the overall management scheme should meet the following requirements. 1. A system should be in a cost-effective and environmentally sound manner. 2. Sludges must be chemically stabilized and bacteriologically safe. 3. Odor-free by product should be applied to crop land. 4. Sludges are sources of fertilizer nutrients and/or soil amendments to enhance crop production. 5. And they can be used as potential pH adjusting agent of the acidified soils. Overall effectiveness of the developed system is experimentally tested to satisfy the preset criteria and requirements. Major experiments are divided into four categories: they are 1. chemical stability test, 2. optimal condition test of stabilization process, 3. bacteriological examination and disinfection tests, and 4. deodorization tests The stabilization process is consisted of the stabilizing reaction process and the drying process. Stabilized wastes is dried by both sun dryer and rotary dryer. It is shown that an additive dosage of about g/kg solid in wastes with a minimum of 5-minutes reaction would be necessary for effective stabilization reaction. The stabilization process is consisted of the stabilizing reaction process and drying process. Stabilized wastes are dried by both sun dryer and rotary dryer. It is shown that an additive dosage of about 300g/kg solid in wastes with a minimum of 5-minutes reaction would be necessary for effective stabilization reaction. In the stabilization reaction process, the pH of wastes is lowered from initial values of 12.3 to 8.6. High pH prevents odor production and kills pathogenic organisms. Organic matter contents in the stabilized wastes are about 50% and the sum of contents of fertilizer elements such as total nitrogen, $P_2O_5$ and $K_2O$ are about 5.3%. The livestock wastes that are stabilized chemically and hygienically can be used as a good soil conditioner and/or organic fertilizer.