• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.1
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• pp.105-110
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• 2021

Objectives: The purpose of this study was to develop a new sterilization plasma device that would be proficient at sterilizing and removing pathogenic bacteria and viruses, and applicable to air purification systems. Methods: In order to understand the performance characteristics, the discharge characteristics of a packed bed DBD reactor and the ozone reduction characteristics of an ozone filter installed at the outlet of the reactor were investigated. Results: The novel packed-bed DBD reactor was proposed, and it was confirmed that the plasma discharge was uniformly and stably discharged throughout the entire layer, and sufficient ozone was generated for sterilization. The ozone filter was tested for three methods: adsorption, adsorption-decomposition, and catalytic decomposition. When the filter thickness was 30 mm, the ozone concentrations were 0.03 ppm, 0.01 ppm, and 0.21 ppm, respectively. The adsorption and adsorption-decomposition methods satisfied the EPA standard of less than 0.05ppm, but the catalytic decomposition method did not. Conclusions: It was confirmed that the adsorption-decomposition method has relatively excellent ozone filter performance and can provide the best ozone filter.

• Journal of Nutrition and Health
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• v.49 no.1
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• pp.43-50
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• 2016

Purpose: This study was conducted to examine prerequisite-program performance of the hospital foodservice operation and develop measures for improvement of prerequisite-program performance. Methods: Data were collected through surveys administered to 168 hospital dieticians in the Seoul, Incheon, Gyeonggi-do, Daegu, and North Gyeongsang areas. Out of total questionnaires, 65 questionnaires were usable and the response rate was 38.7%. Statistical analyses were performed using the SPSS program (ver 20.0) for ${\chi}^2-test$ and one-way ANOVA. Results: According to the result of the prerequisite-program evaluation, the percentage of 'appropriate', 'needs to be improved', and 'inappropriate' was 44.6%, 47.7%, and 7.7%, respectively. The score for the 'inappropriate' group was significantly lower than that of the 'appropriate' group or 'needs to be improved' group on the food safety management (p < 0.001), preparation facility management (p < 0.001), water management (p < 0.001), and storage transportation management (p < 0.05) parts. Holding rate of foodservice facility and equipments in the 'appropriate' group were significantly higher than in the others on convection oven (p < 0.01), air conditioner (p < 0.01), three-compartment sink (p < 0.01), hot-holding equipment (p < 0.01), cold-holding equipment (p < 0.05), exclusive thawing refrigerator (p < 0.05), and sterilizer for sanitary shoes (p < 0.05) items. Conclusion: To improve the quality of hospital foodservice, foodservice managers and HACCP specialists should develop and implement a prerequisite-program and a HACCP plan considering the characteristics of the hospital foodservice operation.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.344-351
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• 2023

Purpose: This study aimed to evaluate the effectiveness of a dielectric barrier discharge (DBD) plasma module for sterilizing airborne bacteria in indoor spaces and measure the concentration of ozone generated during plasma discharge. Method: The DBD plasma module was installed in a 76m³ space, and air samples were collected under various discharge times to compare the reduction of airborne bacteria. Result: The results showed a significant decrease in airborne bacteria, ranging from 92.057% to 99.999%, with an average ozone concentration of 0.04 ppm, below the reference value. Conclusion: The study suggests that plasma discharge can be used as a means of preventing the spread of airborne bacteria and viruses, while ensuring safety for human exposure.