• 산업융합연구
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• 제18권4호
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• pp.15-21
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• 2020

원자력발전소의 순환수 계통 해수배관에 차단밸브가 설치되어 있지 않을 경우 복수기 내부 세관(튜브)에서 해수 누설 등의 이상 발생시, 정비 및 보수를 위해 최소한 순환수 펌프 1대를 정지하여야 하며, 최악의 경우에는 발전정지를 하여야 한다. 그러나 순환수 계통 해수배관에 차단밸브를 설치할 경우, 복수기 이상 발생 시 병열로 연결된 복수기의 해당 수실만 차단 가능함으로 발전소 출력 손실을 최소화 할 수 있다. 본 논문에서는 원자력발전소 순환수 계통의 복수기 수실에 차단밸브를 설치할 경우, 순환수 계통의 유량변화, 계통의 구조적 건전성, 복수기 진공도에의 영향을 평가하였다. 평가결과, 복수기 수실 차단밸브 설치에 따른 유량은 밸브 완전 개방시 0.3% 감소하며, 완전 잠금시에는 4.5% 감소하였다. 또한 유량감소에 따라 복수기 진공도는 떨어지나 계통의 건전성은 유지됨을 알았다.

• 대한수의학회지
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• 제42권3호
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• pp.327-333
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• 2002

The study was carried out to examine the distribution and survival rate of Listeria monocytogenes (L monocytogenes) from various source of waters using improved isolation method. In comparision of enrichment media for isolation of L monocytogenes from water, the isolation rate and 50% detection limit of the pathogen were higher in UVM modified Listeria enrichment broth (UVM) than Listeria enrichment broth (LEB). On the other hand, when compared the selective media for isolation of the pathogen from water, the isolation rate was highest in culture at Oxford agar followed by Fraser agar, and LEB agar. In order to improve enrichment method, 100 ml of water samples with 0.1 CFU/ml of L monocytogenes was inoculated into 10 ml of UVM concentrated at 10-fold, and incubated for 24 h at $36^{\circ}C$. Isolated frequency of the pathogens in improved enrichment method completely corresponded with common (filter) method. Of a total mumber of 147 water samples from river, lake and sea, the pathogen was isolated from 1 of 39 (2.6%) river water samples and 1 of 75 (1.3%) sea water samples, but no pathogen was isolated from 33 lake water samples. Serotypes of 2 isolates were identified as type 1. L monocytogenes decreased in number from 7.2-7.4 to 4.2-4.7 log CFU/ml for 1 week poststorage (5 and $20^{\circ}C$), but the pathogens were able to be detected in river and sea water until 8 weeks after storage. However, in tap water, L monocytogenes were decreased to undetectable level after 2 weeks of storage.

• 대한수의학회지
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• 제35권3호
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• pp.497-504
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• 1995

Isolation of Staphylococcus hyicus subsp. hyicus from the skin of healthy chickens was performed and biochemical characteristics of the isolates were examined. Staphylococcus hyicus subsp hyicus was isolated from 129(14.8%) of 874 healthy chickens. The rate of isolation of this organism from chickens was found to vary depending upon the poultry farms at the isolation rate of 0% to 38.7% and this organism was isolated more frequently from adult chickens of over 1 year old than young chickens. All of the isolates were negative for haemolysis on rabbit, sheep, pig and chicken blood agars, protein A and ${\beta}$-glucuronidase, but positive for coagulase using pig plasma, heat-stable DNase, phosphatase and Tween 80 hydrolysis. Hyaluronidase was positive in 97.7% of isolates, but their reaction was weaker than that of swine strains of Staphylococcus hyicus subsp hyicus. The isolates were biotyped on the basis of the reactions for protease, urease, nitrate, galactose, trehalose and lactose, and 11 biotypes were found among the 129 isolates of Staphylococcus hyicus subsp hyicus.

• 환경위생공학
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• 제10권3호
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• pp.35-44
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• 1995

This study was carried out in order to compare the methods for Salmonella spp. isolation from sewage and to settle the most appropriate conditions for that isolation. The direct enrichment method was more effective than the pre- enrichment method for Salmonella spp. isolation. The rate of detection was much higher when the specimens were enriched at $41.5^{\circ}C$ than when at $35^{\circ}C$. Usage of XLBG agar medium showed better results for Salmonella isolation than that of SS medium. It can be suggested that the most effective combination for Salmonella spp. isolation was the direct centrifugation(3,000 rpm 100m1)- direct enrichment($41.5^{\circ}$C)-usage of XLBG medium.

• 성인간호학회지
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• 제14권1호
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• pp.26-33
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• 2002

Purpose: This is a clinical experimental study aimed to provide basic data to ensure quality care. The purpose of this study is to increase nurses hand washing behavior and decrease respiratory isolation rate of MRSA. Method: This study was conducted in Kangnam St. Marys hospital. The subjects included 5 nurses working at the NS ICU and 165 specimen for nasal swabs and 46 specimen for sputum cultures from 106 patients admitted to the NS ICU. The data were collected from June to September 2000. Results: 1.The percentage of the nurses hand washing was 15.6percent but was improved to 46.5 percent after the educational intervention. In particular, hand washing behavior was increased in situations such as after suctioning, before parenteral nutrition, and after providing hygiene care. 2. Results of nasal swab showed that MRSA isolation rate was reduced from 42.8 percent before the education to 18.6percent after the education. The sputum culture results also showed that the MRSA rate was reduced from 40.7percent before the education to 34.6percent after the education. Conclusion: The findings showed the nurses' strict hand washing behavior and use of disposable gloves and paper towers as well as use of hand sterilization spray by visitors or families can decrease the MRSA isolation rate in the NS ICU patients. Since the NS ICU patients may have respiratory complications due to long-term hospitalization, the nurses regular hand washing is important enough to be emphasized. Future research should be focused on the impact of nurses' hand washing behavior on the incidence of pneumonia, an iatrogenic infection.

• Transactions on Electrical and Electronic Materials
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• 제2권3호
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• pp.24-27
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• 2001

The end point of oxide chemical mechanical polishing (CMP) have determined by polishing time calculated from removal rate and target thickness of oxide. This study is about control of oxide removal amounts on the shallow trench isolation (STI) patterned wafers using removal rate and thickness of blanket (non-patterned) wafers. At first, it was investigated the removal properties of PETEOS blanket wafers, and then it was compared with the removal properties and the planarization (step height) as a function of polishing time of the specific STI patterned wafers. We found that there is a relationship between the oxide removal amounts of blanket and patterned wafers. We analyzed this relationship, and the post CMP thickness of patterned wafers could be controlled by removal rate and removal target thickness of blanket wafers. As the result of correlation analysis, we confirmed that there was the strong correlation between patterned and blanket wafer (correlation factor: 0.7109). So, we could confirm the repeatability as applying for STI CMP process from the obtained linear formula. As the result of repeatability test, the differences of calculated polishing time and actual polishing time was about 3.48 seconds. If this time is converted into the thickness, then it is from 104 $\AA$ to 167 $\AA$. It is possible to be ignored because process margin is about 1800 $\AA$.

• Smart Structures and Systems
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• 제25권5호
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• pp.543-557
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• 2020

This paper presents a series of experimental and numerical investigations on a vertical isolation system with quasi-zero stiffness (QZS) property. The isolation system comprises a linear helical spring and disk spring. The disk spring is designed to provide variable stiffness to the system. Orthogonal static tests with different design parameters are conducted to verify the mathematical and mechanical models of the isolation system. The deviations between theoretical and test results influenced by the design parameters are summarized. Then, the dynamic tests for the systems with different under-load degrees are performed, including the fast sweeping tests, harmonic excitation tests, and half-sine impact tests. The displacement transmissibility, vibration reduction rate, and free vibration response are calculated. Based on the test results, the variation of the transmission rule is evaluated and the damping magnitudes and types are identified. In addition, the relevant numerical time history responses are calculated considering the nonlinear behavior of the system. The results indicate that the QZS isolation system has a satisfactory isolation effect, while a higher damping level can potentially promote the isolation performance in the low-frequency range. It is also proved that the numerical calculation method accurately predicts the transmission character of the isolation system.

• 한국의료질향상학회지
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• 제28권2호
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• pp.39-49
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• 2022

Purpose:The infection and isolation program used at a university hospital in A city was assessed and improved to provide medical staff with easy-to-understand information on isolation precautions and infectious diseases. Methods: Based on the results of the root cause analysis, the infection and isolation alarm computer program was improved. Subsequently, a survey was conducted with infection control leaders and unit managers (n=98) within the department to evaluate the degree of improvement. Results: The isolation registration and release procedures were simplified and unified to prevent confusion among the relevant departments. Additionally, the screen composition was improved so that various information related to infection can be easily accessed. After improvement in the program, the rate of isolation registration (53.0% to 100.0%, p<.001) and user satisfaction (67.6% to 92.2%) improved. Conclusion: This study will help improve the program so that other medical institutions can comply with the isolation precautions in accordance with the type of infections.

• 한국환경보건학회지
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• 제33권1호
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• pp.16-20
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• 2007

Vibrio parahaemolyticus was investigated for analysis of distribution and antibiotic susceptibility at the markets, Seoul in 2004. The average isolation rate was 26.8%(306/1,143) and the highest rate with 64.9% was obtained in August. The isolation rates from December to April was 0.0%. It is more effective to inoculate into the enrichment medium, alkaline pepton water by swabbing a sample with a cotton ball rather than pouring mixed sample. The isolation rates were from 24.4% to 37.1% in domestic samples and from 9.8% to 26.8% in imported ones. All of the isolates were resistent to ampicillin and ticarcillin and most of them were sensitive to chloramphenicol, tetracycline, nalidixic acid, amoxicillin, ceftriaxone, streptomycin, kanamycin, trimethoprim/sulfamethoxazol, ampicillin/sulbactam, ciprofloxacin.

• 대한전자공학회논문지
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• 제23권6호
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• pp.801-806
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• 1986

The effect of SiH2Cl2 -HCl gas on the growth rate of epitaxial layer is studied. The temperature, pressure and gas mixing ratio of SiH2Cl2 and HCl are varied to study the growth rate dependence and selective Si epitaxy. The P-n junction diode is fabricated on the epitaxial layer and electrical characteristics are examined. Also, using selective Si epitaxy, a possibility of thin dielectric isolation process, that gives an independent isolation width on the mask dimension, is examined.