• Journal of the Korea Convergence Society
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• v.13 no.3
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• pp.281-289
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• 2022

Plasma ozone is utilized in a variety of applications in the field of sterilization due to its high sterilization performance. Dielectric materials used in DBD(dielectric barrier discharges) are mainly polymer, quartz and ceramics. These dielectric layers have the advantage of limiting the amount of supplied electron charge and allowing plasma to occur evenly on the surface of dielectric. Actually, the target or environment for sterilization is often a complex structure, so research and academic study are needed by utilizing the concept of space sterilization. In this study, the device is applied to generate DBD plasma at atmospheric pressure for disinfection due to the effectiveness in producing radicals and ozone. The generator of plasma ozone is a basic structure of dielectric barrier discharge by placing ceramic tube dielectrics and stainless steel electrical conductors at regular intervals. Various applications can be developed based on the proposed design method. Plasma ozone generation for space sterilization device is recognized as an excellent sterilization device. Through the design and verification of the device, we intend to establish an optimal design of the spatial sterilization device and provide the basis data for sterilization applications.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.1
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• pp.63-70
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• 2009

The air sterilization systems are investigated experimentally in this paper. The goal is to reduce bacteria, mold and viruses in office air by using a UV sterilizer installed inside a partition panel and wall-mounted unit. These systems allow occupants to turn the system on/off and to control the incoming air speed and direction. The partition air sterilization system conditions and sterilizes the air, and then delivers the clean air into the personal task area through the partition panels, which are connected to the pressurized under-floor plenum. Room air exits through the return grills mounted on the ceiling. The wall-mounted air sterilization system sterilizes the air, and then delivers the clean air to the personal task area from the wall. In this study a full-size experimental environment is established to investigate the immunization performance of these air sterilization systems. A typical office space scale is used in this study in order to find an optimal system to achieve a sterilized healthy micro-environment. Multiple system parameters, including volume flow rate and velocity of supplied air, were regulated during the experiments. The more air contact these air sterilization systems had, the better disinfection performance. Over 90% of eradication ratios were obtained by these two air sterilization systems. The results indicate that these systems can efficiently disinfect office air contamination.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.6
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• pp.353-360
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• 2010

Recently H1N1(swine flu) and SARS has been infected widely in the world; we have to care about germs and virus in indoor air environment. The air sterilization system investigated in this study allows occupants to turn on/off and to control the incoming air speed and direction. To predict the performance of air sterilization system without real experiment, a simulation is considered to compare and analyze the performance of the air sterilization systems in a typical office space. Multiple system parameters including volume flow rate and velocity of supply air were varied and investigated during the simulation. The investigation result shows that difference (between simulation and experiment) was about 3.5% in case of minimum air flow rate and about 0.2% in case of maximum air flow rate. The results indicate that multi-zone simulation technique can be used to predict the performance of a sterilization system in personalized office.

• The Korean Journal of Food And Nutrition
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• v.31 no.2
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• pp.301-307
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• 2018

In this study, a relatively effective process is used to sterilize Escherichia coli on the surface of micro-sized calcium citrate powder using nitrogen and argon as process gases in a low-temperature vacuum plasma treatment. The purpose of this study is to confirm and to introduce the effectiveness of homogeneous surface treatment for the sterilization of fine inorganic powder by the rotatable low-temperature RF plasma system designed by ourselves. The results of the test using 3M petrifilm showed that there were no remarkable spots in the case of the surface of plasma treated powder, whereas the untreated powder showed many blue spots, which indicating that the E. coli was alive. After 5 days, in the same samples, the blue spots were seen to be larger and darker than before, while the plasma-treated powder showed no changes. The results from FE-SEM analysis showed that the E. coli was damaged and/or destroyed by reactive species generated in the plasma space, resulting in the E. coli being sterilized. Furthermore, the sterilization effects according to the selected parameters ($N_2$ and Ar; flow rate 30 and 50 sccm) adapted in this study were mutually similar, regardless of such different process parameters, and this indicates that homogeneous treatment of powder surfaces could be more effective than conventional methods. Therefore, the plasma apparatus used in this study may be a practical method to use in a powerful sterilization process in powder-type food.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.1
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• pp.7-13
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• 2013

Bio Clean Room(BCR) and pharmaceutical product manufacturing facilities require careful assessment of many factors, including HVAC, controls, room finishes, process equipment, room operations, and utilities. Flow of equipment, personnel, and product must also be considered along with system flexibility, redundancy, and maintenance shutdown strategies. It is important to involve designers, operators, commissioning staff, quality control, maintenance, constructors, validation personnel, and the production representative during the conceptual stage of design. Critical variables for room environment and types of controls vary greatly with the clean space's intended purpose. It is particularly important to determine critical parameters with quality assurance to set limits and safety factors for temperature, humidity, room pressure, and other control requirements. In this paper, oxygen cluster ion equipment was utilized in order to enhance the indoor air quality and to prevent the airborne infection of ward in hospital. Moreover, the performance test of the equipment was also performed in order to develop the optimal sterilization system of BCR using the equipment.

• Journal of Radiation Industry
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• v.10 no.4
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• pp.205-210
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• 2016

This study was conducted to evaluate the combined effect of gamma irradiation and different conditions (vacuum packaging, antioxidant and freezing) on the microbiological and sensory characteristics of freeze dried Manila clam porridge (MCP) for immuno-compromised patient food. MCP can be sterilized at 1 kGy to 10 kGy. The initial counts of total aerobic bacteria and yeast molds in the non-irradiated MCP were $2.4{\pm}0.5$ and $1.2{\pm}0.3{\log}\;CFU\;g^{-1}$, respectively, but gamma irradiation significantly decreased the total aerobic bacteria to below the detection limit ($1{\log}\;CFU\;g^{-1}$) (5 kGy). Moreover, gamma irradiation effectively eliminated yeasts/molds at dose below than 1 kGy. However, gamma irradiation accelerated the increase of lipid oxidation and therefore, decreased the sensory characteristics of MCP as irradiation dose increased. To improve the sensory qualities of gamma irradiated MCP, combination treatment (vacuum packaging, 0.1% vitamin C) were applied. There was no significant difference in the overall acceptance scores between the combined-treatment sample (5.6 points) and the non-irradiated samples (6.0). The results indicate that combination treatment (vacuum packaging, 0.1% vitamin C) may help to maintain the quality of MCP. Therefore, it considered that irradiation of MCP with combined treatment and this is an effective method for the consumption as a special purpose food such as for space travel or immuno-compromised patients.

• Journal of Chest Surgery
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• v.7 no.1
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• pp.47-60
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• 1974

During the past 10 years 114 patients with empyema have been treated in hospital of Chonnam University. There were 87 males and 27 females ranging from 20 days to 70 years of age. The etiology was pyogenic pneumonia in 36.7%, tuberculosis in 22.7%, paragonimiasis in 8.8%, post-thoracotomy in 5.4%, post-trauma in 4.4%, lung abscess in 3.5%, malignancy in 3.5%, post-esophageal operation in 1.8%, and sterile in 10.5%. The over-all mortality rate was 2% [3 patients]. The majority of deaths occurred in patients with associated systemic illness [liver cirrhosis in I, and renal tuberculosis in I] and resistant tuberculosis for anti-tuberculosis drugs in one patient. Adequate drainage and obliteration of the pleural space continues to be the most important aspect of treatment and can frequently be achieved by closed chest tube thoracostomy in acute empyema especially in children. The more chronic thick-walled or loculated cavities require open drainage [open window therapy], decortication, thoracoplasty, sterilization, and myoplasty for closure of tracheobronchial fistula.

• The Korean Journal of Pain
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• v.4 no.1
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• pp.26-30
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• 1991

Continuous epidural analgesia is widely used in pain management. We investigates the incidence of contamination of epidural catheters used in epidural catheters for pain control. The tips of epidural catheters were examined for bacterial growth after use. In culture from 250 patients undergoing continuous epidural catheterization, 33(13.2%) catheters were found to be contaminated: staphylococcus epidermis 66.9%; staphylococcus aureus 12.1%; alpha streptococcus 12.1%; and others 9.1%. One significant epidural infection occured. One of the most common causes of the epidural infection during long time epidural block is the transmission of the microorganism from the contaminated skin to the epidural space along the epidural catheter. To prevent epidural infection, sterilization of the skin around the epidural catheter is essential.

• Journal of Chest Surgery
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• v.13 no.4
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• pp.475-485
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• 1980

For the past 5 year 6 months from January 1975 to June 1980, 176 patients with empyema have been treated in Chonnam University Hospital. They were 134 males and 42 females ranging from ] 8 days to 69 years of age. [mean age: 26.1 years] The duration of illness prior to treatment was relatively shorter in pediatric group than in adult group, that is, the duration of less than 1 month was 89.5% in pediatric group and 38.0% in adult group. In bacteria study there were Staphylococcus 26.1%, Streptococcus 17.6%, E. coil 10.8%, Pseudomonas 10.8%, Diplococcus pneumoniae 5.7% and Candidia. And 4 children and 3 adults had infections of two species of bacteria. The underlying pathologic lesions were pyogenic pneumonia 34.7%, tuberculosis 29.5%, paragonimiasis 15.3%, trauma 9.7% and postoperative state. The over-all mortality rate was 1.7% [3 patients]. The causes of death were sepsis In 1 child and sepsis secondary to esophageal fistula in 2 adults. Adequate drainage and obliteration of the pleural space seems to be the most important aspect of treatment and can frequently be achieved by initial tube drainage in acute empyema, especially in the pediatric group. The chronic thick walled or loculated cavities required open window therapy, decortication, resection therapy and sterilization. Modified Eloesser`s operation and 0.3-0.5% potadine irrigation brought good result in the patients who had general weakness, marked pulmonary parenchymal destruction due to pyothorax, and pyothorax with severe bronchopleural fistula.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.1051-1059
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• 2007

Bioterrorism intends to cause mass casualties and social panic by means of malicious pathogenic microorganisms. Environmental decontamination becomes very important as a follow-up measure if that happens. Conventional methods for decontamination is that aqueous disinfectants are being sprayed for killing or not spreading microorganisms with the purpose of preventing infection. However, these procedures are not enough to perfectly sterilize space or surface inside of building, requiring additional measures such as surface disinfection or gas treatment methods. This article deals with the issues about the present decontamination procedures, global trends, in order to formulate suggestion for advanced environmental decontamination.