• 한국지반환경공학회 논문집
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• 제18권11호
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• pp.35-40
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• 2017

한랭지역에 건설된 터널은 낮은 기온으로 인하여 콘크리트 라이닝 배면의 동결이 발생하게 되며, 콘크리트 라이닝의 손상을 발생시켜 터널구조물의 내구성을 감소시킨다. 터널 라이닝 배면 지반의 동결을 억제시키기 위하여 터널 라이닝 표면에 발열체를 부착하고 일정시간 동안 발열시켜 콘크리트 라이닝 내부의 온도변화를 측정하였다. 냉동챔버를 제작하여 현장현황을 모사하고 발열체는 탄소나노튜브(CNT, Carbon Nano Tube) 재료를 플레이트로 제작하여 표면에 부착하고 전기공급을 통해 발열시켰다. 발열체를 발열시킴에 따라 콘크리트 라이닝의 내부 위치별 온도변화 분포를 측정하였으며, 외기온도 및 발열온도의 유지시간에 따른 영향을 분석하였다.

• KSBB Journal
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• 제16권4호
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• pp.398-402
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• 2001

본 연구에서는 고정화된 한천분해효소가 충진된 packed-bed reactor를 이용하여 한천올리고당을 연속생산하였다. Packed-Bed 형 Reactor의 H/D를 조절하여 생산율이 가장 좋은 조건을 살펴 본 결과, H/D=14인 것으로 나타났으며, 한천올리고당의 연속생산시 35 h에서 효소활성반감기를 나타내었다. Packed-Bed Reactor내에서 기질 1 g/L agar, 1unit 고정화효소, 4$0^{\circ}C$, flow rate 24 mL/min 조건하에서 연속반응 시켰을 때, 중합도 4의 한천올리고당이 주로 생산되었으며 중합도 6당, 2당순으로 생산됨을 알 수 있었다. 또한 다중으로 연결된 반응기를 이용한 결과, 기질 1 g/L agar, 4$0^{\circ}C$, 48 mL/min의 조건하에서 41.7 mg/h의 한천올리고당이 생산됨으로서 다중으로 연결하지 않은 반응기보다 2.3배 한천올리고당의 생산율이 증가하였음을 알 수 있었다.

• Clinical and Experimental Reproductive Medicine
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• 제14권1호
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• pp.1-6
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• 1987

The Radionuclide test (RN test) using radioactively labelled human albumin microspheres was developed recently to evaluate the patency and functional capacity of the fallopian tubes. 57 infertile women underwent this procedure as a part of their infertility work up. The results of the radionuclide evaluation were compared with those of the hysterosalpingography (HSG) and further the surgical findings of the laparoscopy and laparotomy. In 64.9%(37/57) of the cases, there was complete agreement between radionuclide test (RN test), hysterosalpingography(HSG) and surgical findings. In comparison with surgical findings, RN test showed a complete agreement rate of 89.4%(51/57), a partial agreement rate of 5.3%(3/57) and no agreement rate of 5.3%(3/57), respectively. Likewise, HSG revealed a complete agreement rate of 80.7%(46/57), a partial agreement rate of 10.5%(6/57) and no agreement 8.8%(5/57), respectively. It would appear that as opposed to the traditional HSG, RN test may give a better understanding of the functional capacity of the tube and may prove a useful method before and after tubal surgery.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.1068-1071
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• 2017

3단 터빈배기부 구성은 터빈 플랜지, 열교환기, 배기덕트와 추력노즐로 이루어진다. 냉가스 가압 방식에 비하여 열교환기 가압 방식을 사용함으로서 추진제탱크 가압을 위한 헬륨가스 자체 무게와 저장 탱크 무게가 감소하는 장점이 있기 때문에 발사체에 열교환기를 사용한다. 가스발생기는 추진제 연료과농 조건에서 연소가 이루어지며, 연소가스 중에 그을음이 많이 포함되어 있기 때문에 열교환 효율이 감소하는 것을 고려하여 열교환기를 설계해야 한다. 본 논문에서는 터빈배기부 구성품 배치, 열교환기 내부 구조 및 제작성을 고려한 설계기법, 기 설계된 노즐 설계를 바탕으로 3단 터빈배기부 재 노즐 설계 형상에 대한 장점을 기술하였다.

• 한국미생물·생명공학회지
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• 제48권2호
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• pp.167-178
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• 2020

Lipase-producing fungi have been isolated from environments containing lipids. The non-dairy creamer industrial waste has a high amount of lipids so it is a potential source for the isolation of lipase-producing fungi. However, the study of fungi that secrete lipase from this industrial waste has not been reported. The purpose of this study was to obtain lipase-producing filamentous fungi from non-dairy creamer industrial waste. Mineral salt and potato dextrose agar were used as media for the isolation process. The qualitative screening was conducted using phenol red agar medium and the quantitative screening using broth medium containing glucose and olive oil. Isolates producing the highest amounts of lipase were identified with molecular methods. We found that 5 out of 19 isolated filamentous fungi are lipase producers. Further analysis showed that isolate Ms.11 produced the highest amount of lipase compared to others. Based on ITS sequence Ms.11 was identified as Aspergillus aculeatus. The lipase activity in medium containing 1% glucose + 1% olive oil at pH 7.0 and 30℃ after 96 and 120 h of incubation was 5.13 ± 0.30 U/ml and 5.22 ± 0.59 U/ml, respectively. The optimum lipase activity was found at pH 7.0, 30℃ and using methanol or ethanol in the reaction tube. Lipase was more stable at 20-30℃ and maintained 85% of its activity. It was concluded that isolate Ms.11 is a potential source of lipase that catalyzes transesterification reactions. Further studies are required to optimize lipase production to make the strain suitable for industry purposes.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.435-435
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• 2010

A inclined slot-excited plasma source is newly designed and constructed for higher flux HNB(Hyperthermal Neutral Beam) generation. The present source is different from the vertical SLAN(SLot ANtenna) sources [1] in two aspects. One is that the slots are inclined, and the other is that the magnetic field is configured to a cusp type. These modifications are intended to make the source plasma operated in sub-milli-torr pressure regime and as thin as possible, both of which is to get higher HNB flux by decreasing the re-ionization rate of the reflected atoms from the neutralizer [2]. The plasma is generated in a quartz tube of internal diameter 170 mm enclosed in a aluminum application chamber of larger diameter 250 mm. The microwave power is fed to the plasma chamber by 8 inclined slots cut into the application chamber wall. The slots are coupled the chamber to a WR280 waveguide wound around it to form a ring resonator. In order to make two slots $\lambda_g/2$ apart in phase, the adjacent slots are rotated in opposite directions. The rotation angle of the slots are set to $60^{\circ}$ from the chamber axis. Between the quartz chamber and the aluminum cylindrical chamber 8 NdFeB magnets are equally spaced and fixed to form the cusp magnetic field confinement and ECR (Electron Cyclotron Resonance) field. In this presentation, the magnetic and electromagnetic simulations, and the measured plasma parameters are given for both the inclined and the vertical slot-excited plasma sources. We also discuss how the sources can be tailored to suit better-performing HNB sources.

• Acute and Critical Care
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• 제33권4호
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• pp.260-268
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• 2018

Background: The purpose of this study was to evaluate the clinical application of modified Burns Wean Assessment Program (m-BWAP) scoring at first spontaneous breathing trial (SBT) as a predictor of successful liberation from mechanical ventilation (MV) in patients with endotracheal intubation. Methods: Patients requiring MV for more than 72 hours and undergoing more than one SBT in a medical intensive care unit (ICU) were prospectively enrolled over a 3-year period. The m-BWAP score at first SBT was obtained by a critical care nursing practitioner. Results: A total of 103 subjects were included in this study. Their median age was 69 years (range, 22 to 87 years) and 72 subjects (69.9%) were male. The median duration from admission to first SBT was 5 days (range, 3 to 26 days), and the rate of final successful liberation from MV was 84.5% (n=87). In the total group of patients, the successful liberation from MV group at first SBT (n=65) had significantly higher m-BWAP scores than did the unsuccessful group (median, 60; range, 43 to 80 vs. median, 53; range, 33 to 70; P<0.001). Also, the area under the m-BWAP curve for predicting successful liberation of MV was 0.748 (95% confidence interval, 0.650 to 0.847), while the cutoff value based on Youden's index was 53 (sensitivity, 76%; specificity, 64%). Conclusions: The present data show that the m-BWAP score represents a good predictor of weaning success in patients with an endotracheal tube in place at first SBT.

• 한방재활의학과학회지
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• 제31권1호
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• pp.149-163
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• 2021

Objectives This study is to review the effectiveness of exercise after lung cancer surgery. Methods Relevant randomized controlled trials (RCTs) were searched in PubMed database. The systematic review was conducted through flow diagram. The risk of biases were assessed through the Cochrane guideline. Characteristics and outcomes were extracted from each study. Meta-analyses of forced expiratory volume in one second (FEV1), 6-minute walk test (6MWT), quality of life (QoL), pulmonary complications were conducted. Results 14 RCTs were selected. In meta-analysis, exercise improved FEV1 (mean difference [MD] 0.14; 95% confidence interval [CI] 0.04 to 0.25; p=0.009; I2=55%) and mean change of FEV1 (MD 0.11; 95% CI 0.02 to 0.20; p=0.02; I2=0%). Exercise increased the distance of 6MWT, but there was considerable heterogeneity (MD 45; 95% CI 21.16 to 68.83; p=0.0002, I2=89%). There was no differences in QoL scores by 2 questionnaires (European Organisation for Research and Treatment of Cancer quality of life questionnaire, short form-36). Exercise reduced the duration of hospital stay (MD -3.32; 95% CI -5.27 to -1.36; I2=0%; 2 studies) but not duration of chest tube intubation (MD -1.37; 95% CI -2.81 to 0.06; I2=0%) and incidence of pulmonary complications (pooled risk ratio 0.54; 95% CI 0.23 to 1.30; I2=0%). Conclusions Exercise might reduce the duration of hospital stay after lung surgery. There was not enough evidence to prove improvement of lung function, aerobic capacity, muscle strength, QoL, and decline of pulmonary complications. Low-quality risk of bias, different units or estimation of outcome, different exercise type and duration, heterogeneity among studies make the evidence of effectiveness weak. Future researches are required to redeem these defects.

• 대한후두음성언어의학회지
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• 제33권2호
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• pp.97-102
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• 2022

Background and Objectives Tracheostomy is a relatively safe procedure, and the recent emergence of COVID-19 has raised the need to perform tracheostomy immediately in the bed of an intensive care unit (ICU) rather than an operating room. The purpose of this study was to determine the occurrence of complications related to surgical tracheotomy performed in the ICU by an ENT specialist. Materials and Method From March 2019 to January 2022, a total of 101 patients underwent tracheostomy in the ICU. Demographics and complications were classified according to postoperative period. Results Within 24 hours after the procedure, bleeding events were confirmed in 2 patients (2.0%) with mild bleeding. One case (1.0%) of ventricular fibrillation occurred shortly after the procedure. There were no complications from 24 hours to 1 week after procedure. After one week, 4 patients (4.5%) had a local infection, and 3 patients (3.4%) had a tube obstruction. During all follow-up periods, there were no serious side effects such as death, major vascular injury, pneumothroax. No complications were observed throughout the entire period in 6 COVID-19 patients. Conclusion The number of complications of surgical tracheotomy in the ICU performed by a specialist was lower than in previous studies, and there were no complications that delayed treatment or endangered life. The ENT training hospitals should provide sufficient training opportunities for residents to perform surgical tracheostomy and strive to minimize complications associated with the procedure and pre- and post-operative management under the detailed guidance and supervision of specialists.

• Journal of Chest Surgery
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• 제57권1호
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• pp.25-35
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• 2024

Background: Prothrombin complex concentrate (PCC) and fresh frozen plasma (FFP) are commonly used to manage bleeding in patients during cardiac surgery. However, the relative efficacy and safety of these 2 strategies remain uncertain. Methods: MEDLINE, Embase, and Cochrane were searched for studies comparing PCC and FFP in patients who underwent cardiac surgery complicated by bleeding. Review Manager (RevMan) ver. 5.4 (Nordic Cochrane Centre, The Cochrane Collaboration) was used for statistical analysis. Binary and continuous outcomes were compared using pooled risk ratios and mean differences, respectively. The meta-analysis protocol was registered in the International Prospective Register of Systematic Reviews under protocol number CRD42022379144. Results: We included 8 studies with 1,500 patients, of whom 613 (40.9%) received PCC. The mean follow-up period ranged from 28 to 90 days. The PCC group had significantly lower chest tube drainage at 24 hours (mean difference [MD], -148.50 mL; 95% CI, -253.02 to -43.99 mL; p=0.005; I² =42%). Fewer units of red blood cells (RBCs) were transfused within the first 24 hours (MD, -1.02 units; 95% CI, -1.81 to -0.24 units; p=0.01; I² =56%), and fewer patients required RBC transfusion within the first 24 hours (risk ratio, 0.85; 95% CI, 0.78-0.93; p<0.007; I² =45%) in the PCC group. There were no statistically significant differences in secondary outcomes. Nonetheless, a subgroup analysis of randomized controlled trials failed to corroborate the results obtained from the main analysis. Conclusion: Our findings suggest that PCC can be effective, without increased adverse events, when compared with FFP in patients undergoing cardiac surgery complicated by bleeding.