• Journal of Welding and Joining
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• 제6권4호
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• pp.16-26
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• 1988

The effect of carbon content on hot cracking of welded carbon steel was investigated Eight steel plates whose carbon content range from 0.02 to 0.23 percent were welded by autogeous gas tungsten are process. Constant strain was applied to the hot crack test specimen under the strain rate of 0.15 mm per second during welding. The hot cracking susceptibility ws high in the rnage of 0.02-0.05 and 0.12-0.23 percent carbon contents. The critical carbon content immune to hot cracking is in the range from 0.07 to 0.12 percent carbon. By electron probe microanalyser, amanganese segregation was not seen significantly in the whole carbon range. But segregation of silicon was higher in the region of low carbon contents. However, sulphur was segregated remarkably in the region betwen 0.18 and 0.23 percent carbon by peritectic reaction. Very smal lamount of dnedritic structure was observed in the region from 0.02 to 0.05 percent carbon by peritectic reaction. Very small amount of dendritic structure was observed in the region from 0.02 to 0.05 percent carbon but the predominant solidification structure was smooth by cellular growth. The higher the carbon content is, the more the columnar dendritic structure was observed.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7215-7219
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• 2013

Background: Variation in metabolic genes is regarded as an important factor in processes leading to cancer. However, the effect of GSTT1 null genotype is divergent in the form of lung cancer. Methods: Studies were conducted at different research databases from 1990 to 2013 and the total odds ratio (OR) and 95% confidence interval (CI) were calculated for lung cancer. Review Manager 5.2 and STATE 12 are employed. Results: Total OR value is calculated from 17 articles with 2,118 cases and 2,915 controls. We discovered no significant increase in lung cancer risk among subjects carrying GSTT1 null genotype [OR = 1.15; 95% CI 0.97-1.36] in this meta-analysis. Conclusion: The GSTT1 deletion polymorphism does not have a significant effect on the susceptibility to lung cancer overall in China.

• 대한조선학회논문집
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• 제48권5호
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• pp.404-413
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• 2011

It is important to assess and improve the warship survivability for the weapon threats which have a critical effect on warship. The survivability of the warship is defined as the capability of a warship to avoid or withstand a man-made hostile environment. The survivability of the warship consists of three categories (Susceptibility, Vulnerability and Recoverability). Firstly, the susceptibility is defined as the inability of a warship to avoid radars, guns, missiles and etc. Secondly, the vulnerability is defined as the inability of a warship to withstand the man-made hostile environment. Finally, the recoverability is defined as the ability of a warship to recover the damaged components and systems. Among them, this paper has described the vulnerability assessment for the hypothetical system which is composed of critical components. Also, the procedure which is suggested to calculate the vulnerable probability of the damaged warship is based on the Vulnerable Area Method.

• 대한수의학회지
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• 제39권2호
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• pp.376-382
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• 1999

A methicillin-resistant Staphylococcus aureus (MRSA) isolate was recovered from a 9-month-old female Shih-Tzu dog with canine distemper virus infection. We performed in vitro antimicrobial susceptibility test to determine the most effective antimicrobial drug against the isolate and thus, to emphasize its potential clinical importance in animal practices. Isolate was confirmed MRSA by oxacillin agar screening test. The isolate was fully resistant to all $\beta$-lactam antibiotics and was susceptible to glycopeptides. Of the other antibiotics, mupirocin, TMP/SMZ (trimethoprim-sulfamethoxazole), and chloramphenicol showed inhibitory effect at the concentration of 4x MIC. The MICs ranged 0.25->$128{\mu}g/ml$, and MBCs ranged 0.5->$128{\mu}g/ml$. The combined TMP/SMZ with cefamandole or novobiocin showed synergistic effect, whereas the combination of novobiocin plus cefamandole or teicoplanin resulted in antagonistic effects. Although MRSA in animals so far has been reported in the geographically limited countries, at least theoretically, it could be occurred in the future more frequently through either human or animal origin. The use of this combination may be of value in this situation. As with all antimicrobial agents, inappropriate or unnecessarily prolonged therapy may contribute to the emergence of resistance strains and loss of efficacy.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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• pp.377-379
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• 2005

This study has been conducted to clarify the effect of sulfur content and welding thermal cycles on reheat cracking susceptibility in the multi-pass weld metal of Fe-36%Ni alloy. Reheat cracking occurred in the preceding weld pass reheated by subsequent passes. Microscopic observations showed that reheat cracking propagated along grain boundaries which resulted in intergranular brittle fractures. The region where reheat cracking occurred and the number of cracks increased with the increase in sulfur content of the alloys. These experimental results suggested that reheat cracking was associated with the embrittlement of grain boundaries, which was promoted by sulfur and subsequent welding thermal cycles. AES analysis indicated that the sulfur segregation occurred at grain boundaries in the reheated weld metal. On the basis of these results, the cause of reheat cracking in multi-pass welding can be attributed to hot ductility loss of weld metals due to sulfur segregation which was accelerated by the reheating with multi-pass welding thermal cycles.

• Human Ecology Research
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• 제53권4호
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• pp.405-412
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• 2015

This study investigated the moderating effect of negative emotionality on the association between teacher-child intimacy and peer interaction based on a differential susceptibility model. The participants were 252 three-year-old children recruited from a day care center and preschool located in Incheon and Gyeonggi province. The teacher-child relationship was measured on a Student-Teacher Relationship Scale. This measure is a type of teacher's report with ratings based on a teacher's daily observations. This scale is composed of closeness items on the degree of warmth and open communication in teacher-child relationships. Peer interactions were measured with a Penn Interactive Peer Play Scale. This measure is composed of play interaction items, play disruption items and play disconnection. Negative emotionality was measured with Child Behavior Questionnaire. Teachers measured teacher-child intimacy and peer interaction scales. Parents reported children's negative emotionality. The research showed that negative emotionality moderated the association of teacher-child intimacy, play interaction, play isolation and play disruption. The magnitude of association between teacher-child intimacy and play disconnection as well as play interaction was greater for high levels of negative emotionality. Teacher-child intimacy was significantly associated with play disruption only for high levels of negative emotionality. The findings of this study support a differential susceptibility model.

• 농약과학회지
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• 제10권4호
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• pp.329-334
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• 2006

본 연구는 시판되고 있는 4종의 항생제계통 살충제(abamectin, emamectin benzoate, spinosad=등록약제, milbemectin=미등록약제)에 대한 아메리카잎굴파리의 발육단계별 약제감수성을 조사하였다. 4약제 모두 알과 유충에 대해서 높은 살충효과를 나타내었으나, 번데기와 성충에 대해서는 낮은 살충효과를 나타내었다. 암컷성충의 산란억제 효과는 abamectin, emamectin benzoate, spinosad에서 100%를 나타내었으며, milbemectin은 85%의 산란억제율을 나타내었다. 섭식흔적수는 milbemectin을 제외하고는 크게 감소되었으며, 성충수명 역시 milbemectin을 제외하고 무처리의 평균 5.5일에 비하여 0.8-1.4일로 크게 단축되었다. 산란효과는 abamectin, emamectin benzoate 그리고 spinosad는 처리 후 7일까지 높았으나, milbemectin은 낮았다.

• 농업과학연구
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• 제50권2호
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• pp.207-218
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• 2023

Duck farming restriction refers to a program in which duck farms suspend their operations for a certain period at times when the risk of avian influenza (AI) is high and receive compensation from the Korean government. This study analyzed the effect of this duck farming restriction on the incidence of AI using data on regional AI incidence rates, the program participation rate, and characteristics of poultry farming in 2016 (before the implementation of the restriction), as well as data from 2020 and 2021 (when new AI outbreaks occurred). In this study, the treatment group was divided into five subgroups according to the policy participation rate and a difference-in-difference (DID) estimation was conducted using certain covariates, in this case the average number of ducks raised, the land area, the number of high-susceptibility farms, the number of low-susceptibility farms, the average number of farms within a 3 km radius, the average distance to the nearest farm, and a year dummy. The results showed that when more than 30% of all duck farms in a region participated in the farming restriction, it had a statistically significant effect on the incidence of AI. Specifically, when more than 30, 40, 50, and 60% of all duck farms participated in the farming restriction, the AI incidence rate decreased by 0.7184, 1.0025, 1.5844, and 1.5843%p, respectively.

• 항공우주시스템공학회지
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• 제7권2호
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• pp.55-59
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• 2013

Before avionics equipment are installed in aircraft, several environmental tests such as temperature, vibration, lightning, fire etc. must be conducted. One of the environmental tests is to substantiate protection designs of lightning indirect effect. It can be showed through RTCA DO-160G, section22 "Lightning Induced Transient Susceptibility" test. An additional test of aircraft level is required as well after installation of avionics equipment.

• 디지털융복합연구
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• 제12권10호
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• pp.477-484
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• 2014

본 연구는 마늘추출물의 병원성 세균에 대한 항균효과를 검증하기 위한 목적으로 시행된 실험연구이다. 항균효과의 대조 항생제로서 Ampicillin $10{\mu}g$(BBL)을 사용하였다. 실험은 2013년 11월과 2014년 1월로 두 차례에 걸쳐 진행하였다. Kirby-Bauer의 disc diffusion method에 따라 감수성을 측정하였고 CLSI에서 제시한 판독기준에 따라 감수성 여부를 판독하였다. 연구결과, 생마늘은 추출법과 관계없이 Ampicillin $10{\mu}g$에 비해 항균효과가 높게 나타났다. 반면 흑마늘은 제조법과 추출방법과 관계없이 4종의 균주에서 저항성을 발현하였다. CLSI의 감수성 판독기준에 따르면 S. aureus와 E. coli에 Ampicillin $10{\mu}g$은 강력한 항균효과를 발현한 반면, 모든 균주들이 흑마늘 추출물에는 저항성을 발현하였다. 다만, 15일의 자연숙성발효한 흑마늘의 에탄올 추출물은 S. aureus와 E. coli에서 성장저지환이 각각 8 mm와 7 mm로 나타나 항균효과의 가능성을 발견하였다는 점에서 본 연구의 의의가 있다하겠다. 향후 마늘의 천연식품보존제 개발 가능성을 검증하기 위해서 흑마늘의 다양한 추출법을 활용한 항균효과에 대한 반복 연구를 제언한다.