• Korean Journal of Health Education and Promotion
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• v.23 no.3
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• pp.53-63
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• 2006

Objectives: The purpose of this study was to analyze the effects of microbe inspections on the hygienic improvement of school food service systems. Methods: Thirty-three school food service systems in Incheon metropolitan city participated in the study from Sep. 2004 to Apr. 2005. Major items of microbe inspections were cutting boards, knives, kitchen towels, and kitchen staff's hands. The Rodac plate and hand plate were used to measure the surface contamination level of germs such as Staphylococcus aureus, Vibrio species, Salmonella species and E. coli. Results: This study compared the results of the inspections in Sep. 2004 and Apr. 2005. The surface contamination level of Staphylococcus aureus and Vibrio species on the knives and kitchen towels had significantly improved. However, the surface contamination level of E. coli on the hands of the kitchen staff had worsened. Conclusions: This study showed that microbe inspections could control the hygienic level of the school food service systems. In the future, microbe inspections should be actively used to improve sanitary conditions in the school lunch system.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.2
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• pp.317-321
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• 2021

As the large-scale renewable energy power plant increases, the high-capacity and compact Energy Storage System (ESS) is required. However, this trend could reduce the insulation reliability of ESS. In this study, the surface flashover characteristics for four types of solid insulators are investigated in the uniform electric field with AC and Lightning Impulse (LI) voltage waveforms under various contamination levels. In addtion, insulator surfaces are compared based on the contact angle before and after surface flashover. The experimental results show that AC flashover voltage is dependent on the materials and the contamination level, but LI flashover voltage is only associated with the contamination level. Especially, AC flashover voltage of PC (PolyCarbonate) is higher than that of other insulators, which is associated with the unique and sequential creepage discharge propagation pattern of PC. The localized discharges on the surface of PC form corresponding tracking points. Then, the interconnected trackings result in the complete flashover. This flashover patterns degrade the surface of PC much more than that of epoxy and Bulk Molding Compoud (BMC). Thus, the contact angle of PC is significantly reduced compared to that of other insulators. The increased hydrophilicity in the surface of PC enhances the insulator surface conductivity.

• Journal of dental hygiene science
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• v.17 no.6
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• pp.472-480
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• 2017

The purpose of this study was to investigate Staphylococcus epidermidis contamination on hands of 20 dental hygienists and 140 equipment surface of 20 dental clinics in a local area, from July to August 2017. The degree of S. epidermidis contamination was measured using a hand plate and a rodac plate and then cultured at $35^{\circ}C$ for 24 hours. Based on hand plate criteria, hand contamination was classified into low, middle, and high groups. Analysis of the variance (ANOVA) of the contamination level of the hand parts of the group surface contamination level of the dental clinic equipment was descriptive statistics after clustering lock count. S. epidermidis contamination was moderate in 55% of the hands of dental hygienists. The area of contamination was 29.45 colony-forming units (CFU) on the palm, followed by the middle finger 7.8 CFU, ring finger 6.4 CFU, and thumb 6 CFU. Medical equipment surface contamination was showed that 3-way handle 4.45 CFU, computer mouse 3.37 CFU, mirror handle 1.60 CFU were higher than other areas. The group with high hand contamination had a high positive correlation with the S. epidermidis contamination of the hand. S. epidermidis contamination level was higher on hands than on the medical equipment surface contamination. Therefore, medical staff should recognize the importance of hand hygiene which should be practiced in the manner suggested by World Health Organization. In addition, the medical team needs to be responsible for performing infection control tasks, implementing infection management guidelines and providing systematic education on infectious disease management.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.241-246
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• 2015

Generally a patient who was injected radiopharmaceuticals for nuclear medicine examination is not an object of isolation. Therefore, when the patient uses toilet, we expect surface contamination of a toilet by radioisotope. The measured value is $25.69Bq/cm^2$(a restroom near admission and administration), $19.39Bq/cm^2$(a toilet near department of radiology). The study shows that 9 of 24 locations in controlled area exceed over surface contamination limit. From now on, we should find source of contamination through measurement radioactive nuclide to apply radiation safety management.

• Journal of Korean Biological Nursing Science
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• v.16 no.2
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• pp.90-97
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• 2014

Purpose: The purpose of this study was to compare the contamination level of uniforms with nasal colonization of Staphylococcus aureus before and after the clinical practice of nursing students. Methods: This study was a survey research, conducting microbial culture by smearing the front surface and the pockets of uniforms, and the nasal cavity both before and after clinical practice on 70 nursing students. For the analysis, descriptive statistics, chi-square test, paired t-test were used for statistical analysis using SPSS 19.0. Results: The contamination level of uniforms increased more significantly after clinical practice on the front surface (p=.008) and pockets (p=.031) than before clinical practice, and Staphylococcus aureus, and Enterobacter aerogenes were detected. Conclusion: Through the results above, it is believed that it is reasonable to do the laundering of clinical uniforms of nursing students once a week. Because it is possible to disseminate disease germs with the contamination of clinical practice uniforms in a hospital environment, it is necessary to offer education for the laundering of uniforms with appropriate management.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.21-22
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• 2005

A study on the wear characteristics of the white metal(Sn-base alloy) bearing as a function of particle contamination level was conducted in order to establish control criteria of the lubricant in the 2-stroke marine diesel engine. Particle contamination level of the lubricants ranged from NAS 10 to 12 for the experiments. Bar-on-plate type wear test was performed using reciprocating wear tester. Based on this study it was found that there was no noticeable difference in weight loss of the white metal for NAS10 and NAS11(particle contamination level). Surface roughness of the white metal bearing after the wear test of 8hrs for the highly contaminated lubricant(NAS12 level) was up to $6{\mu}m$ in Rmax whilst that of the less contaminated lubricants(NAS10 & 11) was less than $1.5{\mu}m$ in Rmax.

• Water for future
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• v.6 no.2
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• pp.19-29
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• 1973

The progressive contamination of water resulted from man's activity and the use of fertilizers is not restricted only to surface water, but also the shallow groundwater is affected. This type of groundwater contamination is mainly restricted to areas composed of permeable, nonconsolidated sediments forming a shallow aquifer. The chloride and the sulfate resulted from man's activity and the use of fertilizers were measured to study the variations of the groundwater contamination. In general, (1) When water level rises, the rate of groundwater contamination becomes less and when water level declines, the rate of contamination is increased. (2) The highly contaminated season is the early-summer and the less contaminated season is the winter or after rainy season. (3) The groundwater in weathering zone without covering layer. (4) The degree of contamination of wells is increased with the increase of well depth and lowing the water table, because of increasing contaminated water from enlargement of the area of influence of the well.

• Korean Journal of Veterinary Service
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• v.24 no.2
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• pp.117-126
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• 2001

To ensure the safety of domestic livestock products, the government made it obligatory to enforce the hazard analysis critical control point(HACCP) in all domestic slaughterhouses. Under the HACCP, most of the hazards generated in slaughterhouses are bio-hazards, especially pathogenic bacteria. In order to reduce to the pathogenic bacteria, critical control point (CCP) is established and controled in the process of slaughter. A study was carried out to measure the level of bacterial contamination of swine carcass in 6 slaughterhouses selected. As a result, the aerobic plate counts(cfu/$\textrm{cm}^2$) of all samples was $10^2$-10 in average, except slaughterhouse C. The level of the aerobic plate counts on the surface of lower loin in slaughterhouse C was $10^4$ and it was considered that slaughterhouse C should set the process of manual transport of carcass as the CCP. Escherichia coli level was the highest in middle line cut surface. Especially, E coli level of slaughterhouses C and D were about 6.5- and 3.0-fold higher than that of other 4 slaughterhouses. Thus, it was considered that the slaughterhouses C and D should set the process of the entrails treatment as the CCP. The air contamination was measured at two point in a slaughterhouse. The air contamination level was 4-13 times higher than that of the standard Japanese slaughterhouses.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.10
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• pp.1461-1470
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• 2012

This paper reports the contamination performance of transmission line porcelain insulators tested under five different contaminant conditions - clean and ESDD (equivalent salt deposit density) level (A, B, C, and D) through measurement of their leakage current under drop of potential method. To estimate the contamination for transmission line porcelain insulators, leakage current waveform and its maximum value were measured under step-up power test. In the clean insulators test, % distortion factors decreased with increasing step-up power, and as the ESDD level increased, some characteristics such as frequency analysis, harmonics and % distortion facotor could be used for contamination diagnosis of the transmission line porcelain insulators.

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.171-177
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• 2024

In this study, two general X-ray device, CT, and MRI inspection devices were selected from general hospitals in the Daejeon area and an experiment was conducted to predict the level of infection by measuring the surface contamination of the inspection devices at different times and to use it as basic data for infection prevention. As a result, the surface contamination level by time zone for general X-ray devices and MRI examination devices was in the order of 13H > 8H > 16H, and for CT examination devices, it was 13H > 16H > 8H, which appeared to be influenced by the number of tests. In addition, the surface contamination results for each part of the test device showed that the highest ATP contamination value was found on the stand bucky handle for the general X-ray device, the headrest for the CT examination device, and the operation switch for the MRI examination device, which was closely related to the number of contacts. As a result of comparing before and after disinfection, all devices showed a significant decrease after disinfection. Based on the results of the experiment, it is believed that it can be used as basic data to identify the level of contamination in radiology laboratories and prevent infectious diseases.