• 농업과학연구
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• 제41권1호
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• pp.35-40
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• 2014

This study was carried out to evaluate the Salmonella cross contamination at retail chicken meat outlets in Kandy, Sri Lanka and to identify the risk factors for Salmonella contamination at retail chicken meat outlets. Fifteen retail chicken meat outlets in Kandy area were randomly selected. Pre-tested questionnaires were used to collect data for identifying risk factors of Salmonella cross contamination at retail outlets and swab samples from meat contact surfaces/utensils were obtained. Out of 57 swab samples collected from meat contact surfaces/utensils, the overall prevalence of Salmonella cross contamination was 21%. Weighing scale (33%), meat containing trays/buckets (27%) and cutting board (25%) showed the highest percentage of Salmonella prevalence whereas knife and showcase showed relatively low percentages, 14% and 9%, respectively. Retail chicken outlets with slaughtering facilities had a significantly higher prevalence of Salmonella cross contamination than those without slaughtering facilities. This higher rate of Salmonella cross contamination at retail chicken meat outlets could be attributed to lack of proper cold chains and minimal facilities, and poor level of hygiene in those outlets.

• 한국표면공학회지
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• 제32권3호
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• pp.239-243
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• 1999

At Present, 200mm wafer technology is being applied for commercial fabrications of 64, 128, and 256 M DRAM devices, and 300mm technology will be evolved for 1G DRAM devices in the early 21th century, recognizing limitations of several process technologies. In particular recognition has been realized in harmful effects of surface contamination of trace metals introduced during devicing processes. Such a guide line for surface metal contamination has been proposed as 1E9 and 1E10 atoms/$\textrm{cm}^2$ of individual metal contamination for wafering and devicing of 1G DRAM, respectively, and so its measurement limit should be at least 1E8 atoms/$\textrm{cm}^2$. The detection limit of present measurement systems is 2E9 atoms/$\textrm{cm}^2$ obtainable with TRXFA(Total Reflection X-Ray Fluorescence Analysis). TRXFA is nondestructive and the simplest in terms of operation, and it maps the whole wafer surfaces but needs detection improvement. X-Ray intensity produced with synchrotron accelerator is much higher than that of conventional X-ray sources by order of 4-5 magnitudes. Hence theoretically its reactivity with silicon surfaces is expected to be much higher than the conventional one, realizing improvement of detection limit. X-ray produced with synchrotron accelerator is illuminated at a very low angle with silicon wafer surfaces such as 0.1 degree and reflects totally. Hence informations only from surface can be collected and utilized without overlapping with bulk informations. This study shows the total reflection phenomenon and quantitative improvement of detection limit for metallic contamination. It is confirmed that synchrotron X-ray can be a very promising alternative for realizing improvement of detection limit for the next generation devices.

• 항공우주기술
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• 제2권1호
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• pp.80-88
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• 2003

본 연구는 임무완성기간까지 다목적실용위성 2호기의 각 표면에 축적되는 입자오염량을 분석한 것이다. 이를 위하여 위성체의 조립 및 시험 기간 및 환경조건을 가정하였다. 본문에서 보여지는바와 같이 다목적실용위성2호의 조립 및 시험이 잘 관리되어지는 조건에서 수행된다면, 위성체의 각 표면에 축적되는 입자 오염량은 적정한 수준내로 관리 될 수 있다. 10,000 class의 발사장 환경을 기준으로 할때, AIT와 발사장에서의 조립 및 시험으로 인해 MSC 및 STA의 내구경에는 500PPM, 외부 표면에는 20000PPM, 위성체의 수평면에는 14000PPM, 수직면에는 1400PPM, radiator에는 1000PPM 및 solar array에는 300PPM의 입자오염량이 축적될 것으로 예상된다.

• 구강회복응용과학지
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• 제18권3호
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• pp.217-224
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• 2002

The purpose of this study was to evaluate the influence of saliva contamination on the resin bonding of the etched metal retainers. The test samples were made of Verabond, and divided into 3 groups. Retainers in group1 had normally etched metal surfaces. Retainers in group2 had normally etched metal surfaces which were saliva-contaminated for 30 seconds and cleaned with streaming, luke-warm for 1 minute and dried thoroughly. Retainers in group3 had normally etched metal surfaces which were saliva- contaminated for 30 seconds and dried thoroughly without water-cleansing. Each 3 group specimen was watched on SEM. A resin core, 5mm in diameter and 6mm in length, was made of Panavia using Teflon mold on the each specimen. These 3 groups were tested to evaluate shear bond strength, using universal testing machine. The results were as follows : 1. The shear bond strength showed no significant difference between group1 and group2. 2. The shear bond strength showed significant difference between group1 and group3. 3. The shear bond strength significant difference between group2 and group3. 4. Scanning electron microscope photographs of group1 and group2 showed no signs of contamination but of group3 showed somewhat contaminated.

• 대한방사선기술학회지:방사선기술과학
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• 제44권3호
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• pp.231-237
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• 2021

The ongoing coronavirus disease 2019 (COVID-19) pandemic has highlighted the importance of hospital hygiene and infection control in hospital settings. To raise hygiene awareness among ultrasound technicians, we evaluated the hygiene status of an ultrasound room, in comparison with that of objects used in daily life. Using the swab method, the following surfaces were examined: eight surfaces in the ultrasound room including the ultrasound probes (convex, linear, sector, 3D), ultrasound track ball, ultrasound keyboard, ultrasound gel (sealed and in use) and pillow as well as four surfaces of everyday objects including subway handles, common computer keyboards, common computer mouse, and cell phones. The streak plate technique was used for inoculation into media, which was observed for the formation of bacterial colonies following incubation for 24 h. Six bacterial strains were detected from objects used in the ultrasound room, including methicillin-resistant Staphylococcus aureus. Four strains of bacteria were detected on surfaces of everyday objects. The equipment and accessories used in an ultrasound room can act as vehicles for infecting patients. Establishment of standardized hygiene protocols and periodic training of the staff are recommended to avoid cross-infection.

• 한국안전학회지
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• 제24권4호
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• pp.47-52
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• 2009

이 연구는 Fluorouracil(5-FU)가 병원에서 암치료제로 쓰이는 세포독성약제의 한 종류이기 때문에 병원내부에 5-FU의 폭로 정도와 그 관리를 위한 가장 효율적인 세척약제를 조사하기 위한 것이다. 이러한 세포독성 약제실이나 종약학 병동에서 근무하는 실무자들은 세포독성약제로 오염된 표면에 빈번하게 접촉하게 되면 세포유전성이나 DNA손상에 대한 위험이 높게 된다. 따라서 이러한 약제의 세척제실험을 위하여 4가지 약제로서 시행한분해시험에서 0.5%(w/v) NaClO 용액만이 5-FU를 즉시 분해시켰으므로 이 용액은 오염표면의 잔유물을 분해시키는데 사용될 수 있다. 세포독성 약제실의 오염표면에서 확인된 농도범위는 2.0에서 $13.8{\mu}g/m^2$까지이고, 종약학 병동의 오염표면에서 측정한 농도범위는 5.39에서 $11.53{\mu}g/m^2$이었다. 5-FU와 같은 세포독성약제로부터 피부오염을 피하기 위하여 작업장의 노출허용기준과 같은 법적인 조치, 완벽한 표면세척제 및 보호구사용과 같은 엄격한 관리기준이 마련되어야 할 것이다.

• 대한영양사협회학술지
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• 제23권2호
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• pp.180-191
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• 2017

The purpose of this study was to identity the probability of cross-contamination from the environment. For this, we examined foodservices at 20 universities/colleges for microbiological analysis of their working facilities and environment as well as their preventive equipment against cross-contamination. Seventy percent of the 20 foodservices were found to maintain one unified working area, which suggests high probability of contamination of food/utensils/equipment in the cooking area by pre-preparation or dish washing. According to the microbiological analysis, the hygiene acceptance ratio of working facilities in the clean zone was 70%, which was higher than the average 45% hygiene acceptance ratio of working facilities in the contamination operating zone. There was a significant difference in the total plate count (P<0.001) and coliform count (P<0.01), which demonstrates that work tables in the clean zone were in a good state compared to those in the contamination operating zone. In the contamination operating zone, refrigerator shelves had a high probability of cross-contamination. Regarding the floor surface and airborne microbes, cooking areas which should be maintained as clean zones had higher cross-contamination probability than those in the contamination operating zone. So corrective actions such as cleaning and sanitizing, keeping dry floors, lowered temperature and humidity, shoe disinfecting facilities, and checking concentrations, are necessary to manage floor surfaces and airborne microbes in the cooking area.

• Safety and Health at Work
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• 제2권3호
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• pp.273-281
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• 2011

Objectives: Studies examining healthcare workers' exposure to antineoplastic drugs have focused on the drug preparation or drug administration areas. However, such an approach has probably underestimated the overall exposure risk as the drugs need to be delivered to the facility, transported internally and then disposed. The objective of this study is to determine whether drug contamination occurs throughout a facility and, simultaneously, to identify those job categories that are potentially exposed. Methods: This was a multi-site study based in Vancouver, British Columbia. Interviews were conducted to determine the departments where the drugs travel. Subsequent site observations were performed to ascertain those surfaces which frequently came into contact with antineoplastic drugs and to determine the job categories which are likely to contact these surfaces. Wipe samples were collected to quantify surface contamination. Results: Surface contamination was found in all six stages of the hospital medication system. Job categories consistently found to be at risk of exposure were nurses, pharmacists, pharmacy technicians, and pharmacy receivers. Up to 11 job categories per site may be at risk of exposure at some point during the hospital medication system. Conclusion: We found drug contamination on select surfaces at every stage of the medication system, which indicates the existence of an exposure potential throughout the facility. Our results suggest that a broader range of workers are potentially exposed than has been previously examined. These results will allow us to develop a more inclusive exposure assessment encompassing all healthcare workers that are at risk throughout the hospital medication system.

• 한국환경보건학회지
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• 제40권6호
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• pp.469-476
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• 2014

Objectives: The purpose of this study was to identify the stains causing infections in dental clinics by analyzing bacterial contamination, as well as to suggest improvements for infection control in dental clinics. Methods: In this study, a questionnaire survey of 47 dental hospitals and clinics located in Gyeonggi-do and Incheon, South Korea was administered from June 2013 to September 2013 and used to investigate the practice rates of infection control by dental hygienists and to analyze the bacterial contamination levels in dental offices. Results: In the studied institutions, the bacterial contamination levels of water lines were $20.9{\times}10^3$ colony forming units (CFU)/mL for three-way syringes, $12.7{\times}10^3CFU/mL$ for high-speed handpieces and $9.8{\times}10^3CFU/mL$ for gargling water. The bacterial contamination levels of surfaces were $44.9{\times}10^3CFU/mL$ in cuspidors, higher than in unit chairs ($2.9{\times}10^3CFU/mL$) and light handles ($6.7{\times}10^3CFU/mL$). The mean bacterial cell count of water lines and surfaces was relatively high in all establishments founded 11 years ago or more, and the mean bacterial cell count of waterline handpieces was $6.27{\times}10^3CFU/mL$ in establishments founded between one and five years ago, $11.16{\times}10^3CFU/mL$ six to ten years ago and $20.04{\times}10^3CFU/mL$ 11 years ago or more, which suggests that earlier foundation is associated with higher bacterial contamination levels with a statistical difference (p<0.01). Similarly, the mean bacterial cell count of cuspidors using water from water lines was also $70.16{\times}10^3CFU/mL$ in at least 11-year-old establishments, statistically significantly higher among in one- to five-year-old ($4.61{\times}10^3CFU/mL$) and six- to ten-year-old clinics ($47.89{\times}10^3CFU/mL$) (p<0.05). Conclusion: This study may be utilized to improve the bacterial contamination levels in dental offices by controlling the characteristics and environmental factors of dental offices that affect the microbial contamination of waterlines and surfaces in such institutions.

• 항공우주기술
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• 제9권2호
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• pp.116-122
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• 2010

우주환경에서 임무를 수행하는 인공위성의 경우, 조립, 시험, 운용시점까지 위성 표면에 흡착되는 오염물질을 최소화하기 위하여 전 기간 동안 세심한 주의를 기울여야 한다. 위성표면에 흡착된 미세한 오염물질은, 고진공 및 고온, 극저온이 반복되는 가혹한 우주환경 속에서 위성의 성능저하 및 효율의 손실을 가져올 수 있다. 예를 들어 위성 표면에 떨어진 입자오염은 별 추적장치의 오류를 발생시킴에 따른 위성 자세제어의 실패를 가져올 수도 있고, 표면에 흡착된 분자오염은 렌즈, 미러, 윈도우 등의 광학기기 및 주요 민감 표면에 작용하여 광학적 특성과 열제어 성능의 저하를 가져올 수 있다. 위성의 조립 및 시험을 관장하는 한국항공우주연구원에서는 위성의 오염물질에 대한 노출을 최소화하기 위해, 오염측정이 이루어지는 청정실을 운용하고 있는데, 본 논문에서는 청정실 및 진공챔버 내의 부유입자측정, 표면입자오염측정, 표면분자오염측정법을 소개하고 오염측정 결과에 대한 분석을 수행하였다.