• Journal of Chest Surgery
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• 제19권4호
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• pp.644-662
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• 1986

Seventy cases of open heart surgery were performed in the department of Thoracic and Cardiovascular Surgery, Pusan Paik Hospital, Inje College, from Oct. 1985 to Oct. 1986. And the results were summarized as follows. 1. Among the 70 cases, there were 48 cases of congenital heart anomalies and 22 cases of acquired rheumatic valvular heart diseases. Age range of the congenital patients was 7 months to 31 years with the mean age of 10 years, and the acquired patients was 18 to 62 years with the mean age of 40 years. 2. The heart-lung machine used for cardiopulmonary bypass was Sarns 7000, 5-head roller pump, and the number and type of oxygenators were 5 of membrane type and 65 of bubble type. For all cases GIK [glucose-insulin-potassium] solution was used as cardioplegic solution for myocardial protection during operation. 3. Among the 48 congenital anomalies, there were 12 cases of ASD group, 29 of VSD group, 3 of ECD, 3 of TOF and one of PDA + MR, and to all of which the appropriate radical operations were applied. 4. Among the 22 acquired valvular diseases, there were 11 cases of mitral valve diseases [MS; 4, MSr; 3, MRs; 4], 3 cases of aortic valve diseases [AR:1, ARs;1, ASr;1], 4 cases of double valve diseases [MRs+TR; 3, MRs+ARs; 1] and 4 cases of triple valve diseases [MSr+ASr+TR; 3, MSr+Ar+TR; 1]. To all the diseased mitral and aortic valves, artificial valve replacement was applied except one [As], in which valve plication was applied. And to all the diseased tricuspid valve, DeVega annuloplasty was applied. 5. The number of replaced artificial valves were 29 in 25 patients [congenital; 3, acquire; 22]. In MVR, 6 of mechanical valves [St. Jude Medical valve; 6] and 15 of tissue valves [Carpentier-Edward valve; 11, lonescu-Shiley valve; 4] were used. In AVR, 6 of mechanical valves [St. Jude Medical valve; 6] and 2 of tissue valves [Carpentier-Edward valve; 2] were used. 6. Postoperative complications were occurred in 12 cases. Among them 11 cases were recovered with intensive cares, but one patient [VSD + Fistula of Valsalva sinus] was expired with low cardiac out put syndrome.

• Journal of Chest Surgery
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• 제24권3호
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• pp.265-270
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• 1991

Since advent of the prosthetic cardiac valve replacement, much efforts for accurate assessing value function in-vivo have been attempted. To evaluate the postoperative functional and morphological status of the replaced cardiac valve prosthesis, 33 patients with valve replacement were studied by transthoracic and transesophageal 2-dimensional echocardiac imaging as well as by color Doppler flow velocity imaging. Twenty four patients had mitral valve replacement. 6 patients had aortic valve replacement and 3 patients had both mitral and aortic valve replacement. There were 34 mechanical and 2 biological prosthesis. Comparing to transthoracic echocardiography, transesophageal approach showed transvalvular regurgitant jet flow amid the prosthetic mitral valve ring during. systole and much clear visualization of cardiac chamber behind prosthesis which could give shadowing effect to ultrasound beam. According to the quantitative grading by the length and area of mitral regurgitant flow, 24 out of 27 mitral valves revealed mild degree regurgitation considered as physiological after prosthetic bileaflet valve replacement and the other 3 valves including 2 biological prosthesis had moderate degree regurgitation which was regarded as pathologic one. 2 cases of left atrial thromboses and 1 case of paravalvular leakage which were not visible by transthoracic approach were identified by transesophageal echocardiography in patients with mitral valve replacement and patients with aortic valve replacement respectively. We conclude that in patients with prosthetic mitral valve replacement, transesophageal 2-dimensional imaging with color Doppler can suggest reliable information beyond that available from the transthoracic access even though it gives patient some discomfort to proceed.

• 한국수소및신에너지학회논문집
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• 제27권3호
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• pp.311-317
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• 2016

This paper presents the flow characteristics of a ball valve used for a gas pipeline. Understanding of the internal flow of a ball valve is an important to analyze the physical phenomena of the valve. Present experimental study was performed by IEC 60534-2-3, the international standard for an industrial control valve testing procedure. Pressure measured at upstream and downstream of the valve, flow-rate and gas temperature passing the inside of the gas pipeline were measured with respect to valve opening rates. Throughout the experimental measurement of the ball valve, empirical equation of the pressure drop between the ball valve according to the mass flow rates is successively obtained using a polynomial curve fitting method. In addition, flow coefficient for determining the valve capacity is also analyzed with respect to valve opening rates using the curve fitting method.

• 대한기계학회논문집B
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• 제25권8호
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• pp.1097-1102
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• 2001

For the purpose of development of high performance gasoline engine, the design technique of the 5-valve(3 intake valves) combustion chamber for a subcompact vehicle has been studied. 3 intake valves cylinder heads were designed by using a 3-dimension CAD program, and steady state flow experiments have been performed with these model. The 5-valve engines, which have larger valve opening areas, have larger intake flow rates and higher flow coefficient than the 4-valve engines. The effects of intake port design parameters of a 5-valve engine on the intake flow rate and bore size were studied, and the design guidelines for the 5-valve engine were established.

• 한국압력기기공학회 논문집
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• 제17권2호
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• pp.75-82
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• 2021

The 3D printing technology is one of the fourth industrial revolution technology that drives innovation in the manufacturing process, and should be applied to nuclear industry for various purposes according to the manufacturing trend change. In nuclear industry, it can be applied to manufacture obsolete items and new designed parts in advanced reactors or small modular reactors (SMRs), replacing the traditional manufacturing technologies. A gate valve body was manufactured, which was obsolete in nuclear power plant, using DED(Directed Energy Deposition) metal 3D printing technology after restoring design characteristics including 3D design drawing by reverse engineering. The 3D printed valve body was assembled with commercial parts such as seat-ring, disk, stem, and actuator for performance test. For the valve assembly, including 3D printed valve body, several tests were performed, including pressure test, end-loading test, and seismic test according to KEPIC MGG and KEPIC MFC. In the pressure test, hydraulic pressure of 391kgf/cm² was applied to 3D printed valve body, and no leak was detected. Also the 3D printed valve assembly was performed well in end-loading and seismic tests.

• Journal of Chest Surgery
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• 제31권3호
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• pp.247-254
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• 1998

저자들은 1986년 8월부터 1996년 5월까지 172례의 환자에서 St. Jude Medical 판막을 사용하여 승모판 치환술을 시행하였다. 병원사망률(hospital mortaliy rate)은 3.5%(6례)였고, 만기사망률(late mortality rate)은 3.3%(5례)였다. 생존한 161명의 환자에서 추적관찰(follw-up)을 시행하였는데 평균기간은 50.23$\pm$0.27개월이었다. 인공판과 관련된 합병증으로는 좌방혈전 및 이로인한 뇌경색으로 사망한 예가 2례있었고, 인공판 심내막염(Prosthetic valve endocarditis)이 발생하여 사망한 예가 1례 있었으며, 항응고요법에 동반된 것으로 추정되는 출혈성 합병증은 2례에서 발생하였다. 전체환자의 10년 생존률은 92.3%이었다. 이상으로 본 흉부외과교실에서는 St. Jude 기계판을 사용하여 승모판 치환술의 중단기 임상성적을 문헌고찰과 함께 보고하는 바이며, 앞으로 계속해서 장기추적관찰에 노력할 생각이다.

• Journal of Chest Surgery
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• 제8권2호
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• pp.89-100
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• 1975

Sixteen cases of cardiac valve replacements have been done in this department since 1970. Twelve cases of mitral valve replacement were done with Beall valve, 2 cases of aortic valve replacement with Starr-Edwards and Magoven valve and 2 cases of double valve replacement using Beall valve for mitral and Magovern valve for aortic. Three patients [18.8%] died during operation. Two cases [12.5%] of hospital mortality occurred because of congestive heart failure and asphyxia due to tracheomalacia 3 months after operation. Follow-up studies from two to 27 months showed excellent results except three cases of late mortality [18.8 %]. Thromboembolism occurred in two double valve replacement patients[12.5%]who were fatal.

• 태양에너지
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• 제16권2호
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• pp.97-112
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• 1996

본 연구는 가정용 가스 보일러 순환펌프의 문제점 보완은 물론 펌프 외부에 설치되어 있는 3way valve를 하우징 내부에 부착한 3way valve 내장형 펌프 하우징을 개발하기 위한것이다. 기존 하우징이 부착된 canned type 순환펌프의 실험결과를 근거로 3way valve 내장형 하우징을 설계 제작하였으며 신형 하우징이 부착된 canned type 순환펌프의 성능실험 및 보일러 전체 시스템에서의 순환펌프 성능 실험을 실시하였다. 실험 결과 신형 3way valve 내장형 하우징을 부착할경우 펌프의 총양정은 평균 $1{\sim}1.7m$, 펌프 효율은 약 25%정도 높게 나타났으며 축동력은 약 4W 감소하였다. 특히 하우징의 중량은 1.4kg에서 0.4kg으로 줄어들었고 제작비는 개당 약 5000원정도 절감할수 있었으며 조립공정의 단축으로 생산비용은 보일러 1대당 약 2만원 정도의 원가절감을 예상할수 있다.

• Journal of Chest Surgery
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• 제24권10호
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• pp.979-986
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• 1991

From October 1988 to November 1989, seven patients underwent valve replacement during the active phase of native valve endocarditis. There were 4 males and 3 females whose mean age was 41 years[range, 16 to 68 years]. Preoperative two-dimensional and Doppler echocardiography showed vegetations and severe valvular regurgitation in all patients. Blood cultures were positive in 4, and negative in 3 patients Organisms were alpha-hemolytic Streptococcus in 2, Staphylococcus epidermidis in 1, Erysipelothrix rhusiopathiae in 1 patient Valve tissue cultures were negative in all patients. Intravenous antibiotic therapy had been done for 3 to 18 days in 5 patients pre-operatively and was not done in 2 patients, Indications for operation were heart failure in h, and systemic emboli in 1 patient. The aortic valve was involved in 3, mitral in 1, and both aortic and mitral in 3 patients, One operative death[14.4%] occurred in patient with cardiogenic shock before operation. Late death occurred in one on 14 months after operation. The remaining 5 patients were followed up over a two year period in good condition. In conclusion, native valve endocarditis with severe heart failure must be considered for early operation.

• Journal of Chest Surgery
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• 제25권12호
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• pp.1556-1562
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• 1992

Forty two consecutive patients who had had valve replacement with St. Jude Medical prosthesis were studied on a view point of intravascular hemolysis. Patients were consisted of 14 mitral valve replacement, and 7 aortic valve replacement, and 21 double, mitral and aortic, valve replacement. Serum LDH, indirect bilirubin, GOT, hemoglobin levels and ret-iculocyte count were pursued in postopeative 1st day, 3rd day, 7th day, 14th day and 21th day. Postoperatively, all patients were not detected paravalvular leakage on the ech-ocardiographical study. The patients with double valve replacement revealed higher levels of LDH on postopeative 14th day[P<0 05] than those with single valve replacement. Among the patients with single valve replacement, the patients with aortic valve replacement revealed slightly higher levels of entire postopeative data, but considered insignificant. There was correlation between the severity of hemolysis and the size of replaced aortic valve. In the postoperative LDH levels, the patients with small sized-aortic valve[less than 21mm in diameter] replacement revealed higher levels of postoperative 3rd day, 7th day and 14th day than those with large size[more than 23mm in diameter]. The patients with high level LDH of greater than 800 WU /L on postoperative 7th day were 61.9%[26 of 42]. The high LDH frequency of DVR was 71.4%[15 of 21], MVR 50.0%[7 of 14] and AVR, 57.1%[4 of 7]. The level of LDH declined gradualiy thereafter through postoperative 3 weeks. In conclusion, intravascular hemolysis after prosthetic valve replacement was dependent on position of valve replacement and size of valve. And this study supports the conventional valve selection and usage in our hospital. The patients with subclinical hemolysis after valve replacement should be placed on a close observation.