• Korean journal of food and cookery science
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• v.27 no.1
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• pp.21-31
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• 2011

The purposes of this study were to investigate the gap in perceived importance-performance between dietitians and food service workers regarding school food service sanitation and to analyze items that should be given priority for improvement. Data were collected by 440 food service workers and 71 dietitians in Gyeongbuk province. All statistical analyses were conducted using the SAS package program (version 8.2 for Windows) for descriptive analysis, t-test, and importance-performance analysis (IPA). According to the performance analysis, there were significant differences between dietitians and food service workers in 18 out of the 20 items. In all of 18 items, the evaluated performance scores according to the food service workers were higher than those of the dietitians. In addition, the results of IPA confirmed the following areas as improvement priorities: proper hand washing of food service workers, cleanliness of trays and utensils, monitoring of temperature of refrigerated/frozen foods and quality of the food materials during inspection, proper washing and disinfection of raw vegetables and fruits and maintenance of CCP records, and control of food holding temperature and methods. In conclusion, dietitians should perform education about sanitation management items that have low perceived importance and should make a plan to improve sanitation management after understanding the gap in perceived importance-performance between dietitians and food service workers.

• Advances in materials Research
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• v.1 no.4
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• pp.311-347
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• 2012

Infections are caused due to the infiltration of tissue or organ space by infectious bacterial agents, among which Staphylococcus aureus bacteria are clinically most relevant. While current treatment modalities are in general quite effective, several bacterial strains exhibit high resistance to them, leading to complications and additional surgeries, thereby increasing the patient morbidity rates. Titanium dioxide is a celebrated photoactive material and has been utilized extensively in antibacterial functions, making it a leading infection mitigating agent. In view of the property amelioration in materials via nanofication, free-standing titania nanofibers (pure and nominally doped) and nanocoatings (on Ti and Ti6Al4V implants) were fabricated and evaluated to assess their efficacy to mitigate the viability and growth of S. aureus upon brief (30 s) activation by a portable hand-held infrared laser. In order to gauge the effect of exposure and its correlation with the antibacterial activities, both isolated (only titania substrate) and simultaneous (substrate submerged in the bacterial suspension) activations were performed. The bactericidal efficacy of the IR-activated $TiO_2$ nanocoatings was also tested against E. coli biofilms. Toxicity study was conducted to assess any potential harm to the tissue cells in the presence of photoactivated materials. These investigations showed that the photoactivated titania nanofibers caused greater than 97% bacterial necrosis of S. aureus. In the case of titania-coated Ti-implant surrogates, the bactericidal efficacy exceeded 90% in the case of pre-activation and was 100% in the case of simultaneous-activation. In addition to their high bactericidal efficacy against S. aureus, the benignity of titania nanofibers and nanocoatings towards tissue cells during in-vivo exposure was also demonstrated, making them safe for use in implant devices.

• Journal of Korean society of Dental Hygiene
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• v.16 no.2
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• pp.313-319
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• 2016

Objectives: The objective of the study was to infection control by analyzing the influence of working environment on infection control activities in the dental hygienists. Methods: The cross-sectional study was based on a survey on a total of 377 dental hygienists working in dental settings. Multiple linear regression analysis was performed to examine the relationship of general characteristics and infection control activities. All statistical analyses were performed using the SPSS for Windows version 20.0, and p<0.05 was considered to be significant. Results: Predictive powers(=Adjusted $R^2$ of the investigated factors such as operation room, sterilization disinfection laundry, dental unit waterline, staff individual, infection control system, personal protective equipment, medical waste, hand hygiene, oral surgical procedures, clinical contact surfaces were adjusted $R^2=0.394$, 0.306, 0.277, 0.244, 0.241, 0.177, 0.165,, 0.154, 0.134, 0.124 respectively. Conclusions: In order to enhance infection control activities, the program development and implementation for the aseptic procedure is very important. The program should include periodic reinforcement of infection control education and regular monitoring of infection control activities.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.3
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• pp.285-291
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• 2016

There has been an accelerating increase in water reuse due to growing world population, rapid urbanization, and increasing scarcity of water resources. However, it is well recognized that water reuse practice is associated with many human health and ecological risks due to numerous chemicals and pathogenic microorganisms. Especially, the potential transmission of infectious disease by hundreds of pathogenic viruses in wastewater is one of the most serious human health risks associated with water reuse. In this study, we determined the response of different bacteriophages representing various bacteriophage groups to chlorination in real wastewater in order to identify a more reliable bacteriophage indicator system for chlorination in wastewater. Different bacteriophages were spiked into secondary effluents from wastewater plants from three different geographic areas, and then subjected to various doses of free chlorine and contact time at $5^{\circ}C$ in a bench-scale batch disinfection system. The inactivation of ${\phi}X174$ was relatively rapid and reached ~4 log10 with a CT value of 5 mg/L*min. On the other hand, the inactivation of bacteriophage PRD1 and MS2 were much slower than the one for ${\phi}X174$ and only ~1 log10 inactivation was achieved by a CT value of 10 mg/L*min. Overall, the results of this study suggest that bacteriophage both MS2 and PRD1 could be a reliable indicator for human pathogenic viruses for chlorination in wastewater treatment processes and water reuse practice.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2602-2608
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• 2015

The aim of this research was microbiological hazard analysis which is required to application of HACCP(Hazard Analysis Critical Control Point) system to chili powder. A processing had been conducted in Yong-Geum Agricultural Production located in Dongnyang-myeon, Chungju-si between January 10, 2014 to June 13, 2014. A manufacturing process chart was prepared by entire level of processing. A changes of microorganism was tested by changing sterilization time in ultraviolet ray sterilization processing which can control microbiological Hazard. As a result, critical Limits is decided as ultraviolet rays lamp $20W{\times}12EA$, sterilization $63{\pm}3$ min of each. The result of the microorganism test after ultraviolet ray sterilization was safe. On the other hand, a microorganism test of manufacturing environment and workers suggested that the microbiological hazard should be reduced through systematic cleaning and disinfection accompanied by personal hygiene based on hygiene education on workers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.646-653
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• 2016

This study performed a microbiological hazard analysis, which is required for the application of HACCP (Hazard Analysis Critical Control Point) system to Pteridium aquilinum and Platycodon grandiflorum. The manufacturing process was made by referring to the typical manufacturing process. Based on microbiological hazard analysis, grandiflorum root contained $6.2{\times}10^3CFU/g$ of bacteria, which has the largest amount of bacteria among the agricultural materials. On the other hand, microbiological hazard analysis of the raw materials and after the disinfecting process of confectionery showed a safe result. A microorganism test of the manufacturing environment and workers suggests that the microbiological hazard should be reduced through systematic cleaning, disinfection and accompanied by personal hygiene based on hygiene education for workers.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.149-154
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• 2005

Conventionally used flocculation tanks require large space and high energy requirement for mixing. Static flocculators using gravel bed filter operate at a lower flow rate ($5-10m^3/m^2{\cdot}h$). Further, the cleaning of this system is difficult. A novel high rate static flocculator/filter developed at UTS packed with buoyant media such as polystyrene, polypropylene has been found to operate at higher filtration rates (30-45 $5-10m^3/m^2{\cdot}h$). They can easily be cleaned with minimal energy. Detailed experiments conducted with an artificial kaolin clay solution show that buoyant media is an excellent static flocculator in producing uniform filterable microflocs (12-15 m) even when it is operated at a high rate of 30-40 m/h. Detailed filtration experiments were conducted in a wastewater treatment plant to treat the biologically treated effluent with a floating media of depth of 120 cm. This filter was able to remove majority of phosphorus and remaining solids. It reduced significantly the fecal coliforms and fecal streptoccoci, thus requiring less amount of chlorine for disinfection. The advantage of this system is the low energy and water requirement for cleaning of filter bed. The periodic backwash adopted 30 seconds air and water and 30 seconds water cleaning every 90 minutes filter operation. Thisis equivalent to 1-2% of filtered water production. Mechanical cleaning system on the other hand, requires very low energy requirement (<1% of filtered water production).

• Restorative Dentistry and Endodontics
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• v.43 no.4
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• pp.46.1-46.10
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• 2018

Objectives: This study was to evaluate the antibacterial effect of different instrumentation and irrigation techniques using confocal laser scanning microscopy (CLSM) after root canal inoculation with Enterococcus faecalis (E. faecalis). Materials and Methods: Mesiobuccal and mesiolingual canals of extracted mandibular molars were apically enlarged up to a size 25 hand K-file, then autoclaved and inoculated with E. faecalis. The samples were randomly divided into 4 main groups according to the system of instrumentation and irrigation: an XP-endo Shaper (XPS) combined with conventional irrigation (XPS/C) or an XP-endo Finisher (XPF) (XPS/XPF), and iRaCe combined with conventional irrigation (iRaCe/C) or combined with an XPF (iRaCe/XPF). A middle-third sample was taken from each group, and then the bacterial reduction was evaluated using CLSM at a depth of $50{\mu}m$ inside the dentinal tubules. The ratio of red fluorescence (dead cells) to green-and-red fluorescence (live and dead cells) represented the percentage of bacterial reduction. The data were then statistically analyzed using the Kruskal-Wallis test for comparisons across the groups and the Dunn test was used for pairwise comparisons. Results: The instrumentation and irrigation techniques had a significant effect on bacterial reduction (p < 0.05). The iRaCe/XPF group showed the strongest effect, followed by the XPS/XPF and XPS/C group, while the iRaCe/C group had the weakest effect. Conclusions: Combining iRaCe with XPF improved its bacterial reduction effect, while combining XPS with XPF did not yield a significant improvement in its ability to reduce bacteria at a depth of $50{\mu}m$ in the dentinal tubules.

• Journal of Korean society of Dental Hygiene
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• v.10 no.5
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• pp.935-945
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• 2010

Objectives : The purpose of this study was to examine the knowledge of dental hygienists on infection control in dental office and their attitude toward that in a bid to provide some information on ways of enhancing the level of infection control in dental office. Methods : The subjects in this study were 220 dental hygienists who worked in dental hospitals and clinics in Busan and South Gyeongsang Province. A survey was conducted from May 17 to June 17, 2010, and the answer sheets from 183 respondents were analyzed with a SPSS WIN 12.0 program. Statistical data on frequency, percentage and mean were obtained, and t-test, Pearson correlation coefficient and one-way ANOVA were utilized. Results : They got a mean of $4.59{\pm}.68$ in six categories of infection control knowledge. They had the best knowledge on dental waste disposal, followed by hand washing, post-sterilization management, instrument disinfection and sterilization, surface management of dental equipment and wearing personal protective equipment. They got a mean of $3.99{\pm}.54$ in attitude, and they scored lowest in practice of surface management of dental equipment. Overall, they scored higher in every aspect of knowledge than in attitude(t=11.410, p=.0.000). There was the greatest gap between their knowledge and practice in surface management of dental equipment (t=13.885, p=0.000), and there was the smallest gap between their knowledge and practice in hand washing(t=5.460, p=0.000). And a positive correlation was found between knowledge and attitude, as better knowledge of infection control led to better attitude toward that(p<.001). Finally, concerning infection control knowledge and attitude by general characteristics, the presence or absence of infection control guidelines made differences to infection control knowledge, and infection control attitude was statistically significantly different according to infection control education experiences(t=6.501, p=.012) and the presence or absence of infection control guidelines(t=22.836, p=.000). Conclusions : In order to bolster infection control in dental office, the related system should be improved to legally require dental personnels to implement infection control. Every dental office must be furnished with infection control guidelines, and sustained education should be provided for dental hygienists to carry out infection control.

• Journal of the Korean Society of Food Culture
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• v.37 no.1
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• pp.1-12
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• 2022

This qualitative study analyzed various environmental factors and difficulties faced by school foodservices during the COVID-19 pandemic. Focus group interviews were conducted by enrolling 12 nutrition teachers and nutritionists. Data collected were subsequently analyzed for changes implemented during the pandemic, in hygiene management, diet management, and distribution management of the school meal. The content and method of delivery of information related to diet guidance and school foodservice by related organizations were also examined. Results of the survey show that personal hygiene (such as maintaining student-to-student distance, checking students for a fever, and hand disinfection) was duly applied, installation of table coverings and distancing between school cafeteria seats were conducted, and mandatory mask-wearing to prevent droplet transmission was enforced. Depending on the COVID-19 situation, the number of students having school meals was limited per grade, and time-spaced meals were provided. To prevent infection, menus that required frequent hand contact were excluded from the meal plan. Overall, it was difficult to manage the meal plan due to frequent changes in tasks, such as the number of orders and meal expenses. These changes were communicated by nutrition teachers and nutritionists wherein the numbers of school meals were adjusted, depending on situations arising from each COVID-19 crisis stage. Furthermore, in some schools, either face-to-face nutrition counseling was stopped entirely, or nutrition education was conducted online. Parent participation was disallowed in the monitoring of school meals, and the prohibition on conversations inside the school cafeteria resulted in the absence of communication among students, nutrition teachers, and nutritionists. Additionally, confusion in meal management was caused by frequent changes in the school meal management guidelines provided by the Office of Education and the School Health Promotion Center in response to COVID-19. In anticipation of the emergence of a new virus or infectious diseases caused by mutations in the years to come, it is suggested that a holistic, well-thought-out response manual for safe meal operation needs to be established, in close collaboration with schools and school foodservice-related institutions.