• Magazine of RCR
• /
• v.4 no.3
• /
• pp.41-44
• /
• 2009

• Journal of Energy Engineering
• /
• v.2 no.1
• /
• pp.1-15
• /
• 1993

내부순환유동층이란 전형적인 기-고체 유동층 내부에 보조장치로서 원형관(draft tube) 또는 평판(partition plate)을 삽입하여 단일용기를 두 개의 층으로 분리하고 층 사이의 개방면적(opening area)을 통하여 입자의 순환이 일어나도록 하는 반응기 형태이다. (중략)

• Journal of Chest Surgery
• /
• v.42 no.4
• /
• pp.464-472
• /
• 2009

Background: We analyzed the clinical results and the factors for survival of patients who underwent extracorporeal life support system after adult cardiovascular surgery. Material and Method: We retrospectively reviewed the medical record of 44 patients (1.6% of the total adult cardiovascular surgical cases) who underwent the use of a ventricular assisted device or extracorporeal membrane oxygenation from January 2002 to August 2008. There were 32 (72.7%) males and their mean age was 61.7$\pm$14.9(range: 20$\sim$73) years old. The mean duration of extracorporeal life support system was 5.3$\pm$3.0 (range: 1$\sim$12) days. Result: Of these 44 patients, 24 (54.5%) patients were successfully weaned from the extracorporeal device. Eighteen (40.9%) survivors were able to be discharged from the hospital. Complications were noted in 38 patients (86.4%). An emergency operation, no usage of a concomitant intraaortic balloon pump and major complications during use of the extra corporeal life support system such as bleeding, flow instability and renal failure were identified as significant risk factors for poor survival on univariated analysis. Owing to educational support and a continuous renal replacement therapy system, the clinical outcomes of these patients have improved since 2006. On multivariated analysis, renal failure and bleeding during extracorporeal life support were significant risk factors for poor survival. Conclusion: Although using. extracorporeal life support systems after adult cardiovascular surgery revealed acceptable clinical results, determining the optimal treatment strategy and further well designed larger studies are needed to improve the survival rate of patients who undergo extracorporeal life support after adult cardiovascular surgery.

• Journal of Chest Surgery
• /
• v.43 no.3
• /
• pp.304-307
• /
• 2010

A 5-day-old neonate (body weight=2.4 kg) with coarctation of the aorta and critical aortic stenosis underwent an interventional balloon valvuloplasty for aortic stenosis. During the intervention, cardiac arrest occurred due to injury of the right carotid artery by the guide wire. An extracorporeal membrane oxygenator (ECMO) was applied. After 1 day's support, total surgical correction was achieved; however, in the immediate postoperative period, cardiac function was severely depressed. We applied a bi-ventricular assist device (bi-VAD) instead of an ECMO and we were able to wean the patient off the bi-VAD device after 3 days' support. The patient was discharged without severe complications.

• Journal of Biomedical Engineering Research
• /
• v.23 no.1
• /
• pp.33-38
• /
• 2002

A Ventricular Assist Device(YAD) is used to support the injured natural heart So. when considering a control algorithm for YAD. it is important to reduce a natural heart's load to enhance its recovery condition. To reduce natural heart's load, a counterpulsation algorithm is used commonly. In this study, we developed a counterpulsation control algorithm for moving-actuator type VAD and tested its usefulness using in vitro MOCK circulatory system. To notice a natural heart's Pumping status, electrocardiogram(ECG) signal was used and as a result of test. the counterpulsation effect between YAD and a natural heart was occurred and Automatic Control Mode Transition was occurred properly.

• Proceedings of the KIPE Conference
• /
• 2016.07a
• /
• pp.60-61
• /
• 2016

본 논문에서는 interleaved 벅-컨버터를 영-전압 스위칭으로 구동하기 위한 새로운 회로를 제안한다. 제안하는 회로는 두개의 벅-컨버터 모듈과 보조 회로로 구성된다. 보조 회로는 coupled-inductor와 커패시터로 구성된다. Coupled-inductor에 흐르는 전류가 스위치가 꺼지기 전에 스위치의 전류의 방향을 바꾸어서 영 전압 스위칭을 달성한다. 제안하는 회로는 보조회로에 반도체 소자를 추가하지 않고 수동 소자만으로 구성하여 신뢰성의 저하를 막는다. 또한 수동 소자만으로 구성된 보조 회로로 인해 발생하는 도통 손실의 증가를 최소화 한다. 제안하는 회로는 시뮬레이션을 통해 검증하였다.

• Solar Energy
• /
• v.17 no.3
• /
• pp.43-49
• /
• 1997

Cycle simulaton of the double effect parallel flow model is applied to a Lithium-Bromide/water system, with the objective of evaluation the possibilities of effectively utilizing waste-heat as a secondary heat source for the low-temperature generator. In this study, cycle simulation has been carried out to clarify the effect heat exchange in order to predict the performance of absorption refrigeration cycles using waste heat.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.5
• /
• pp.557-562
• /
• 2023

This study reviewed the use of soil injection materials using circulating resources as injection materials for the steel pipe multi-stage construction method. The tests performed were homogel time and homogel compressive strength. The steel pipe multi-stage construction method is an auxiliary construction method for tunnels, and the expression of initial strength after construction is an important factor. The better the strength development in the initial stage, the more it can be used as an injection material suitable for the multi-stage steel pipe construction method. As a result of laboratory test, it was found that the homogel time of the injection material using circulating resources required more time than the mixing ratio using cement as the injection material. In addition, it was found that the initial strength curing time satisfying 2MPa was required for more than 24 hours. Therefore, it was confirmed that the injection material using recycled resources required a longer initial curing time than cement of the same mixing ratio.

• Proceedings of the KIPE Conference
• /
• 2010.07a
• /
• pp.148-149
• /
• 2010

본 논문에서는 친환경 차량용 보조배터리 충 방전을 위한 3상 양방향 DC-DC컨버터를 제안한다. 제안한 컨버터는 클램프 스위치의 동작으로 전압 및 전류공진을 최소화하고 대전류단의 순환전류를 감소시켜 전류정격을 줄였다. 제안하는 컨버터의 이론적 해석과 시뮬레이션을 통해 타당성을 검증하였다.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.06a
• /
• pp.825-828
• /
• 2009

고형원료인 폐기물의 감량화 및 자원화 기술 중 가장 대표적인 기술로 폐기물의 소각(incineration)기술과 가스화(gasification)용융기술을 들 수 있다. 폐기물 가스화 기술은 폐기물 내의 탄소, 수소 성분을 가스화하여 CO, $H_2$가 주성분인 합성가스(synthesis gas, syngas)로 전환하여 불연물은 용융되어 환경적으로 무해한 슬래그로 회수하는 기술이다. 폐기물 가스화 용융 시스템으로 발생된 합성가스를 재순환하여 사용하는 합성가스 재순환시스템을 통해 가스화에 필요한 열을 시스템 내에서 대체하여 사용하는 기술개발은 폐기물 가스화 용융기술의 경제성을 높일 수 있다. 본 연구에서는 고형 폐기물 가스화반응에 의해 발생되는 합성가스를 재순환하여 폐기물 가스화 용융 시스템내의 자체 에너지원으로 활용할 수 있도록 하는 합성가스 재순환 시스템 및 버너의 운전특성을 고찰하였다. 합성가스의 재순환 장치에서의 운전 압력 제어 및 유량제어를 통해서 안정적인 합성가스 재순환 성능과 재순환버너의 연소 성능을 유지할 수 있었다. 합성가스 재순환버너에 의한 16,800 $kcal/Nm^3$ 조건 및 33,600 $kcal/Nm^3$ 조건에서 운전시에도 가스화기의 운전온도는 안정적으로 유지됨에 따라 생산된 합성가스의 가스화기 보조연료 대체 및 에너지절감이 가능한 것으로 판단된다.