• Journal of Chest Surgery
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• v.32 no.7
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• pp.675-680
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• 1999

We describe here two cases of anterior tracheoplasty utilizing an autologous pericardial patch. One patient was a 9 year-old female who had a congenital long tracheal stenosis associated with major vascular anomalies including pulmonary artery sling. One-stage correction was done under the support of an extracorporeal membrane oxygenation system. She required a prolonged ventilation support for 10 days postoperatively until the implanted pericardium was fixed to the mediastinal structures. The other patient was a 8 year-old male who had acquired tracheal stenosis following a complicated tracheostomy. By applying additional support over the pericardial patch with the costal cartilage, an endotracheal tube could be removed immediately after the operation. Both patients have been doing well in a postoperative follow-up of over a year, and there have been evidences of growth in the reconstructed trachea.

• Journal of Korean Biological Nursing Science
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• v.6 no.1
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• pp.43-52
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• 2004

Purpose : The purpose of this study was to find effects of early oral water intake on thirsty feeling, nausea, and vomiting after ambulatory surgery. Method : Sixty patients who received PET(Pressure Equalizing Tube) insertion surgery under general anesthesia were conveniently sampled and divided into two groups. Experimental group was instructed to drink water after two hours and control group was directed to intake water after three hours postoperatively. Data were collected from May 1, 2002 to August 31, 2002 at ambulatory surgery center of Asan Medical Center. The thirsty feeling, nausea and vomiting score between experimental and control group were compared at the time of recovery, recovering consciousness, 2hr, 3hr, right before discharge and/or 24hr(telephone interview) postoperatively. The collected data were analyzed by SPSS 8.0 statistic program. Result : Result of this study are as follows. 1) There was a statistically significant difference(t=-10.31, p=0.00) in the occurrence of thirsty feeling at the 3hr postoperatively between experimental and control groups. 2) There was a statistically significant difference($x^2=6.66$, p=0.02) in the incidence of nausea during the 2hr postoperatively between experimental and control groups. 3) There was no difference($x^2=0.35$, p=0.55) between groups in vomiting scores. Conclusion : It was generally known that the delay of oral water intake decreases post operative complications. But, this study shows that early oral water intake decreases discomfort of thirsty and there was no adverse effects on the occurrence of postoperative nausea and vomiting.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.6
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• pp.503-508
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• 2007

In this study, the aeroelastic response and stability of bearingless rotors are investigated using a large deflection beam theory. The outboard main blade, flexbeam, and torque tube are all assumed to be an elastic beam undergoing arbitrary large displacements and rotations. The finite element equations of motion obtained from Hamilton's principle. Two-dimensional quasi-steady strip theory is used to evaluate aerodynamic forces. In hover, the modal approach method based on coupled rotating natural modes is used for the stability analysis. In forward flight, the nonlinear periodic blade steady response is obtained by integrating the full finite element equation in time through a coupled trim procedure with a vehicle trim. The results of the full finite element analysis using the large deflection beam theory are compared with those of a previously published modal analysis using the moderate deflection-type beam theory.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.473-473
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• 2013

전자종이, 입을 수 있는 디스플레이, 플렉서블 터치 스크린, 투과성 면 등과 같은 차세대 플렉서블 투명 전자소자는 기계적으로 유연하고 광학적으로 투명하며 무게가 가벼운 특성을 지녀야 할 것으로 예상된다. 현재까지는Indium tin oxide (ITO), zinc tin oxide (ZTO), carbon nano tube (CNT)와 polyimide 계열의 물질들이flexible, wearable, and transparent electronics (FWTEs) 소자의 electrode, active channel, dielectric layers로 제안되어 활발히 연구되었다. 최근에는 높은 이동도(~200,000 cm2/Vs) 및 유연성(fracture strain of 30%), 투명도 (97.5% for monolayer)와 같은 특성을 갖는 그래핀에 대한 연구가 활발히 진행되고 있다. 그러나 그래핀을 차세대 플렉서블 투명 전자소자 구현에 적용하기 위해서는 플렉서블하고 투명한 절연체의 확보 및 그래핀의 진성(intrinsic) 특성 유지 등과 같은 문제점들을 해결해야 한다. 따라서, 본 연구팀에서는 그래핀 기반 플렉서블 투명 전자소자의 게이트 절연층으로 적합한 poly-4-vinylphenol/poly (melamineco-formaldehyde) (PVP/PMF) 물질을 제시하고 이에 대한 전기적 재료적 분석을 수행하였다. 특히 다양한 PVP와 PMF의 비율 및 가열(annealing 혹은 curing) 온도에서 형성된 PVP/PMF 층의 화학 및 전기적 특성을 FT-IR, I-V, 그리고 C-V 측정을 통해 확인하였다. PVP/PMF는 유기절연 물질의 하나로서 높은 유연성과 투명도를 갖고 있을 뿐만 아니라 그래핀에 적용 시 그래핀의 진성 특성을 확보할 수 있다. 이는 PVP/PMF에 존재하는 hydroxyl (-OH) 그룹과 그래핀 상에서 정공(hole)을 공급하는 것으로 알려져 있는 -OH 그룹들간의 cross-linking 메커니즘에 의한 것으로 예상된다. 마지막으로 최적화된 PVP/PMF (낮은 hysteresis 전압)를 게이트 절연층에 적용하여 polyethylene terephthalate (PET) 기판 및 연구원의 손가락 위에 95.8%의 투명도 및 0에 가까운 Dirac point를 갖는 그래핀 기반 플렉서블 투명 전자소자를 성공적으로 집적하였다.

• Journal of Sensor Science and Technology
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• v.15 no.5
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• pp.309-316
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• 2006

The $SnO_{2}$ thin film sensors were fabricated by a thermal oxidation method. $SnO_{2}$ thin film sensors were treated in $N_{2}$ atmosphere. The sensors with $O_{2}$ treatment after $N_{2}$ treatment showed 70 % sensitivity for 1 ppm $H_{2}S$ gas, which is higher than the sensors with only $O_{2}$ treatment. The Ni metal was evaporated on Sn thin film on the $Al_{2}O_{3}$ substrate. And the sensor was heated to grow the Sn nanowire in the tube furnace with $N_{2}$ atmosphere. Sn nanowire was thermally oxidized in $O_{2}$ environments. The sensitivity of $SnO_{2}$ nanowire sensor was measured at 500 ppb $H_{2}S$ gas. The selectivity of $SnO_{2}$ nanowire sensor compared with thin film and thick film $SnO_{2}$ was measured for $H_{2}S$, CO, and $NH_{3}$ in this study.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1527-1535
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• 2018

Bacterial strain BAS23 was isolated from rice field soil and identified as Bacillus amyloliquefaciens. Based on dual culture method results, the bacterium BAS23 exhibited potent in vitro inhibitory activity on mycelial growth against a broad range of dirty panicle fungal pathogens of rice (Curvularia lunata, Fusarium semitectum and Helminthosporium oryzae). Cell-free culture of BAS23 displayed a significant effect on germ tube elongation and mycelial growth. The highest dry weight reduction (%) values of C. lunata, H. oryzae and F. semitectum were 92.7%, 75.7%, and 68.9%, respectively. Analysis of electrospray ionization-mass spectrometry (ESI-MS) and $^1H$ nuclear magnetic resonance (NMR) spectroscopy revealed that the lipopeptides were iturin A with a C14 side chain (C14 iturinic acid), and a C15 side chain (C15 iturinic acid), which were produced by BAS23 when it was cultured in nutrient broth (NB) for 72 h at $30^{\circ}C$. BAS23, the efficient antagonistic bacterium, also possessed in vitro multiple traits for plant growth promotion and improved rice seedling growth. The results indicated that BAS23 represents a useful option either for biocontrol or as a plant growth-promoting agent.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.1
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• pp.39-45
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• 2009

The CRT(Cathode Ray Tube) displays have been substituted for FPDs(Flat Panel Displays) such as LCD(Liquid Crystal Display) and PDP(Plasma Display Panel) because they have a convex surface, large volume and heavy weight. The productivity of FPDs is greatly dependent on the area of thin glass panel with $0.6{\sim}0.8mm$ thickness because FPDs are manufactured by cutting a large-scaled thin glass panel with patterns to the required product dimensions. So FPD's industries are trying to increase the area of thin glass Panel. Through FEM(Finite Element Method) analysis and fluid analysis, we developed an non-contact and air-floating conveyor system which consists of transport-module, distributor, horizontal/vertical changer and controller for the 7th generation glass panel (2,200mm in width, 1,870mm in length and 0.7mm in thickness). The design technology developed in this study can be effectively applied to a conveyor system for a larger-scaled thin glass panel.

• Journal of the Korean Society of Safety
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• v.35 no.4
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• pp.23-31
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• 2020

In the construction sector, there were 99 fatalities from falls associated with steel tube and system scaffolds for three years from 2016 to 2018 and out of which 27.3 percent (27 workers) were found to have occurred during installing and dismantling procedure. To erect scaffolding which is installed for the work at height, the work platforms are generally installed first and the safety guardrails are installed and vice versa to dismantle. As a result, workers are exposed to the risk of falling because they erect and dismantle scaffolding without guardrails. To minimize the risk of falling, it is necessary to study a new construction method that can erect or dismantle scaffolding while guardrails are installed (called advanced guardrail system). This study analyzed advanced guardrail system in terms of safety regulation, workability and economic efficiency by investigating the domestic situation on the use of scaffolding, reviewing domestic and foreign standards for guardrails and conducting economic feasibility study. The results of this study is expected to greatly contribute to preventing falls in scaffolding installation and dismantlement procedure. As a follow-up study, empirical research is required including physical test of scaffolding with advanced guardrail system and effectiveness analysis after trial applications.

• Journal of Veterinary Clinics
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• v.25 no.4
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• pp.227-230
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• 2008

To determine the distribution of feline blood types and then to estimate the risk of neonatal isoerythrolysis (NI) in non-pedigree cats, we typed blood of 482 cats of both genders and various breeds (336 domestic shorthair cat and 146 pedigree) from August 2005 through July 2007. Blood samples from Seoul and Kangwon province were typed within 5 days after collection by the simple tube method. High-titer anti-A antiserum and anti-B reagent, prepared with Triticum vulgaris lectin, were used to determine type A and type B blood, respectively. The majority of cats were type A (n = 465, 96.5%) and only 3.5% (n = 17) were type B. No type AB blood were detected. Blood type distributions among the non-pedigree and pedigree cats were similar: for non-pedigree cats, 96.4% were type A and 3.6% were type B, whereas for pedigree cats, 96.6% were type A and 3.4% were type B. All type B cats had a very strong agglutination reaction to anti-A antiserum: 8 sample for 3+ and 9 for 4+. Assuming 19% of estimated frequency for the type-B allele in domestic cats, the calculated proportion of random mating from this population at risk for developing NI was 3.4%. Based on this finding, it is strongly recommended that blood typing be performed prior to any blood transfusion or breeding to minimize blood type incompatibilities. Further comprehensive studies on the titer of naturally occurring antibodies in cat populations in Korea and the prevalence of possible NI in practice are clearly required.

• Journal of The Korean Association For Science Education
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• v.23 no.2
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• pp.176-188
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• 2003

Self-induction is an important concept in the field of electromagnetism, which is dealt with in all the high school physics textbooks. According to the results of the survey on self-induction, most of general high school students and even science high school students have overgeneralized concepts that high self-induced emf. are produced whenever the switch is turned off in the circuit containing inductors. The reasons of this overgeneralization on self-induction could be explained through the analysis of current high school physics II textbooks. Main reasons can be attributed to the fact that, by depending on their intuitive ideas, students try to vaguely explain the concept, based on lighting up of Ne tube in the special circuit. This study found out qualitative method to have students effectively understand self-induction based on quantitative interpretation to gain scientific understanding on self-induction.