• The Korean Journal of Food And Nutrition
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• v.31 no.2
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• pp.308-312
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• 2018

Even though chlorine dioxide ($ClO_2$) is utilized in a pre-treatment due to its effective sterilizing activity for microorganisms and its safety for food, it has a limitation in maintaining freshness of the food product. In this study, a low-concentration $ClO_2$ gas was produced in a packaging form of air-permeable gel pack so that it could be released continuously over several days. The amount of $ClO_2$ gas emission and microbial inactivation effect against foodborne pathogens were measured during the release of $ClO_2$ gas. As a result of measuring the change of color in order to confirm whether the chlorine dioxide gas was eluted in the form of a sustained release, the yellowness was significantly higher at higher gel pack concentration and higher value during storage periods. The slow-released $ClO_2$ gel-pack showed clear inactivation effect against Escherichia coli and Staphylococcus aureus with 99.9% inactivation efficiency. As a result of measuring the sterilization effect of Listeria monocytogenes by the concentration of chlorine dioxide gas, the sterilization effect was increased as the concentration was increased. Therefore, the slow-released $ClO_2$ gel-pack is feasible to apply for industry usages.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.199-206
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• 2016

The aim of this study was to establish the optimal conditions to design a shoe rack that could effectively sterilize and deodorize shoes contaminated by various bacteria. The manufacture and evaluation of a shoe rock was conducted for one year from October 2014 to September 2015. The antibacterial efficacies were evaluated using Escherichia coli and Staphylococcus aureus by JIS Z 2801:2010. The deodorization efficiency was identified by the standard method for deodorization efficiency evaluation of an indoor air cleaner established by Korea Air Cleaning Association, SPS-KACA002-132:2006. The results showed that antibacterial evaluation showed more than 99.9% of the sterilization effects on Escherichia coli and Staphylococcus aureus after exposure to ultraviolet (UV) light for 30 seconds. The average deodorization efficiency for the test gases was 42.5%. The temperature in the shoes and in the shoe rack was lower than $40^{\circ}C$ and $25^{\circ}C$, respectively, when the UV lamp was turned on for 5 minutes and off for 25 minutes repeatedly. This was controlled by turning the UV lamp on and off to maintain the appropriate temperature in the shoes. In conclusion, the real deodorization efficiency is expected to be higher than the measured value because the internal volume of the shoe rack was smaller than the test chamber used to measure the deodorization efficiency. The deodorization effect could be increased further by the sterilization of bacteria causing bad odors in shoes. Further studies will be needed to determine the temperature deviations within the shoe rack to provide constant conditions.

• Food Science and Preservation
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• v.23 no.7
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• pp.960-966
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• 2016

This study was conducted to explore the potential for use of atmospheric pressure dielectric barrier discharge plasma (atmospheric pressure DBD plasma) as a non-thermal sterilization technology for microorganisms in dried red pepper. The effects of key parameters such as power, exposure time and distance on the sterilization efficiency and the quality of red dried pepper by the atmospheric pressure DBD plasma treatment were investigated. The results revealed that the plasma treatment was very effective for sterilization of Staphylococcus aureus, with 15 min of treatment at 1.0 kW and 20 mm sterilizing 82.6% of the S. aureus. Increasing the power or exposure time and decreasing the exposure distance led to improved sterilization efficiency. The atmospheric pressure DBD plasma treatment showed no effect on the ASTA (American spice trade association) value or hardness of dried red pepper. Furthermore, no effects of atmospheric pressure DBD plasma treatment were observed on the sensory properties of dried red pepper. To assess the storage stability, the dried red pepper was treated with atmospheric pressure DBD plasma (1.5 kW power, 15 min exposure time and 10 mm exposure distance), then stored for 12 weeks at $25^{\circ}C$. Consequently, the ASTA value, hardness and capsaicin concentration of dried red pepper were maintained.

• Journal of Biosystems Engineering
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• v.26 no.4
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• pp.391-398
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• 2001

A robot system for clone replication and gridding, which is a preliminary state of the genome research, was developed and evaluated its performance. This gridding robot system consisted of 1) a gridding heat that replicated the clone, 2) a manipulator, as a part of body of robot, which transferred the gridding head along x-, y-, z-axis, 3) a well plate arranging board, 4) a sterilization unit, and 5) a control unit. Performance of the system was evaluated with 1) repeatability of the robot system, 2) clone replication efficiency, 3) time requirement of the replication, and 4) sterilization efficiency. The repeatability error of the robot system showed 0.219 mm and 0.094 mm in the direction of x- and y-axis, respectively. The success rate of the clone replication with the gridding head was 100% on the membrane filter. The time required for the replication was four minutes and fifty-five seconds from the four 96 well plates to a 384 well plate meanwhile the required time with well experienced hand labor was three minutes thirty-five seconds. The gridding operation of clone could not be done by hand labor and the required time with robot system for the gridding on the membrance filter with the control program 5$\times$5: 1 copy and 384 gridding pins was twenty minutes and twenty-five seconds. The efficiency of the sterilization was considered to be satisfactory since no growth of fungi was found around the area of replication in the membrane filter.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.222-227
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• 2017

This study aimed to explore the potential for food-industry application of atmospheric pressure dielectric barrier discharge plasma (atmospheric pressure DBD plasma) as a non-thermal sterilization technology for microorganism. The effects of the key parameters such as power, oxygen ratio, exposure time and distance on Escherichia coli KCCM 21052 sterilization by the atmospheric pressure DBD plasma treatment were investigated. The experimental results revealed that increasing the power, exposure time or oxygen ratio and decreasing the exposure distance led to an improvement in the sterilization efficiency of E. coli. Furthermore, the atmospheric pressure DBD plasma (1.0 kW power, 1.0% (v/v) $O_2$, 5 min exposure time and 20 mm exposure distance) treatment was very effective for the sterilization of food-borne pathogenic bacteria. The sterilization rate of E. coli, Bacillus cereus KCCM 40935, Bacillus subtilis KCCM 12027, Bacillus thuringiensis KCCM 11429 and Bacillus atrophaeus KCCM 11314 were 72.3%, 74.6%, 88.5%, 84.7% and 91.3%, respectively.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.1169-1174
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• 2013

The objective of this work was to increase the efficiency of ultraviolet-light emitting diodes at 375 nm for sterilization. Since $TiO_2$ had antibacterial properties, which were attributed to the appearance of hydroxyl radicals and superoxide radical anions on the surface species under ultra violet radiation at about 387 nm, photo-reactive layers such as Ag-doped $TiO_2$ were coated on aluminum substrates by electrostatic spraying. Crystallinity and surface morphology of the coating layer were examined by X-ray diffraction ${\theta}-2{\theta}$ scan and field emission-scanning electron microscope, respectively. In an antibacterial test, we observed above 99% reduction of Escherichia coli populations on 3 or 5 mol% Ag-doped $TiO_2$ layers after irradiation for 2 hrs at 375 nm, while very low inactivation on bare aluminum substrates occurred after irradiation as the same condition.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1209-1215
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• 2017

Microwave sterilization was performed to inactivate the spores of biofilms of Bacillus cereus involved in foodborne illness. The sterilization conditions, such as the amount of water and the operating temperature and treatment time, were optimized using statistical analysis based on 15 runs of experimental results designed by the Box-Behnken method. Statistical analysis showed that the optimal conditions for the inactivation of B. cereus biofilms were 14 ml of water, $108^{\circ}C$ of temperature, and 15 min of treatment time. Interestingly, response surface plots showed that the amount of water is the most important factor for microwave sterilization under the present conditions. Complete inactivation by microwaves was achieved in 5 min, and the inactivation efficiency by microwave was obviously higher than that by conventional steam autoclave. Finally, confocal laser scanning microscopy images showed that the principal effect of microwave treatment was cell membrane disruption. Thus, this study can contribute to the development of a process to control food-associated pathogens.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.138-143
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• 2006

This research emphasis the commercialize and experiment in the quality of water treatment by making water treatment reactor. The hybrid water plasma torch used this research is excellent in tans of economical efficiency because of using existent neon transformer. Further more, It has excellent energy efficiency because it is manufactured by low electric power. Especially hybrid water plasma torch used this research has two filed of water plasma and inputs each strong point into the water. Following The data such as dissolved ozone(2.8[ppm]), hydrogen peroxide(100[ppm]), 2[PH], are very affordable data and immensely useful in sterilization. Those data have excellent result: perfect eradication of a colon bacillus within maximum 10 minute applying to sterilization processing of a colon bacillus.

• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.570-575
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• 2005

In this study, we have manufactured electrodeless ultraviolet lamp which has a long life and a high degree of efficiency than the existing electrode UV lamp used in sewage effluent sterilization disinfection. First, we investigated change of UV intensity and temperature of lamp by activation materials. The best results for the dose response experiments were 250 minutes stabilizing to UV intensity of $300{\mu}W/cm^2$ and surface temperature $200{\sim}250^{\circ}C$ in Hg/Ind's weight ratio 95/5. When electrodeless UV lamp emits light for prolonged hours, surface temperature of lamp increases. therefore, temperature change is studied using a duplex lamp for cooling in actual sewerage process. Also, manufactured electrodeless UV lamp showed sterilization efficiency of more than 99.9% as result that experiment manufactured electrodeless UV lamp by E-coli. for sterilization disinfection of sewage effluent.

• Advances in environmental research
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• v.2 no.1
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• pp.1-8
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• 2013

There is a significant demand to make various dissolved gases in water. However, the conventional aeration method shows low gas mass transfer rate and gas utilization efficiency. In this study, a novel rotating wheel entraining gas method was developed for making high dissolved $O_2$ and $O_3$ in water. It produced higher concentration and higher transfer rate of dissolved $O_2$ and $O_3$ than conventional bubble aeration method, especially almost 100% of gas transfer efficiency was achieved for $O_3$ in enclosed reactor. For application of rotating wheel entraining gas method, aerobic bio-reactor and membrane bio-reactor (MBR) were successfully used for treatment of domestic and pharmaceutical wastewater, respectively; and vacuum ultraviolet $(VUV)/UV+O_3/O_2$ reactors were well used for sterilization in air/water, removal of dust particles and toxic gases in air, and degradation of pesticide residue and sterilization on fruits and vegetables.