• Journal of Chest Surgery
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• v.18 no.3
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• pp.391-397
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• 1985

Ebstein`s anomaly is a rare congenital cardiac malformation and characterized by downward displacement of an abnormal tricuspid valve cusps. But until now, the ideal surgical correction is still controversial. We present a case of Ebstein`s anomaly experienced lately. The patient was 13 year old girl with the complaints of dyspnea on exertion, fatigability and cyanosis. Echocardiography revealed downward displacement of septal leaflet of tricuspid valve and atrialized right ventricle. Cardiac catheterization and cineangiography revealed ASD and large right atrium. During operation, the atrialized right ventricle was plicated and tricuspid annuloplasty was done. And the two secundum type ASD`s were closed by direct suture closure. The patient`s postoperative course was uneventful and discharged on the 24th postoperative days.

• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.333-337
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• 1986

Three cases of intestinal lipoma near the ileocecal valve are described. In patients of cecal and ileocecal valve lipoma, they had right lower quadrant abdominal pain secondary to partial intestinal obstruction. In rarely developed segmental lipomatosis of the ileum, the patient had right abdominal mass and pain to fecal impaction of the diverticula. Diagnosis may be made by an abnormal roentgenographic pattern and confirmed by colonoscopy. Surgical removal of the affected segment results in cure in symptomatic patients.

• Journal of Veterinary Clinics
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• v.18 no.3
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• pp.273-278
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• 2001

Chronic mitral valvular insufficiency (CMVI) is the most common heart disease in dogs. The prevalence of CMVI is age-dependent. CMVI is usually affected to small to medium size breeds. It is more prevalent in males than females. The characteristic lesions of CMVI are caused by an acquired chronic structural degeneration of the mitral valve defined as endocardiosis or myxomatous degeneration. The main clinical signs are cough, respiratory distress, weakness and pleural effusion and ascites by secondary right-sided heart failure. The most prominent clinical finding is a systolic heart murmur. The thoracic radiography and echocardiography are useful methods in diagnosis of CMVI. Thoracic radiographic findings are left atrial enlargement, left main stem bronchial compression and pulmonary edema. Echocardiography is confirmed to increased left atrial and ventricular dimension, mitral regurgitation, mitral valve thickening and abnormal movement. Thoracic radiography and echocardiography are used to obtain a definite diagnosis of CMVI, and then to study the progression of the condition.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.694-699
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• 2004

The purpose of this study is to estimate the availability of acoustic emission method to the internal leak of the valves at nuclear power plants. The acoustic emission method was applied to the valves at the site, and the background noise was measured for the abnormal plant condition. From the comparison of the background noise data with the experimental results as to relation between leak flow and acoustic signal, the minimum leak flow rates that can be detected by acoustic signal was suggested. When the background levels are higher than the acoustic signal, the method described below was considered that the analysis the remainder among the background noise frequency spectrum and the acoustic signal spectrum become a very useful leak detection method. A few experimental examples of the spectrum analysis that varied the background noise characteristic were given.

• Journal of Chest Surgery
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• v.17 no.2
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• pp.244-249
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• 1984

Surgical treatment of partial endocardial cushion defect was accomplished in Feb. 1984 in this department. The 5 year old male patient had history of frequent upper respiratory tract infection and since his age of 3 years dyspnea on exertion and palpitation were noted but there were no cyanosis and clubbing. A thrill was palpable on the apex and grade IV/IV harsh systolic ejection murmur and diastolic murmur was audible on it. Liver was palpable about 3 finger breadths and no ascites. Chest X-ray revealed increased pulmonary vascularity, moderate cardiomegaly [C-T ratio; 0.69], and enlarged left atrium. EKG showed first degree heart block, RVH, LVH, and LAD. Echocardiogram showed paradoxical ventricular septal movement and abnormal diastolic movement of the anterior leaflet of mitral valve. Right heart catheterization resulted left to right shunt [Qp:Qs:2.1:1 ] and moderate pulmonary hypertension [60/40 mmHg]. Left ventriculogram showed mitral regurgitation [Grade III/IV] and filling of left atrium and right atrium nearly same time. Operative findings were: 1.Primum type atrial septal defect [3x2 cm] 2.Cleft on the anterior leaflet of mitral valve. 3.No interventricular communication and cleft of tricuspid valve leaflet. The mitral cleft was repaired with 4 interrupted sutures. The primum type atrial septal defect was closed with Dacron patch intermittently at endocardial cushion and continuously remainder. The post operative course was uneventful and discharged on 22nd postoperative day in good general conditions.

• Journal of Chest Surgery
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• v.26 no.6
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• pp.457-462
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• 1993

We retrospectively studied 34 patients who underwent operations of ascending aortic aneurysm and aortic valve replacement from August 1979 to July 1992 at the Yonsei Cardiovascular Center. Eight patients underwent supracoroanry non-composite graft replacement and separate aortic valve replacement[group I]. Twenty six patients underwent valved composite graft replacement with reimplantation of coronary arteries[group II]. Two cases in group II died within 1 month after the operation. Among the 32 survivors 28 patients have been followed up for an average of 59 months ranging from 1 months to 159 months. During the follow up periods, a pseudoaneurysm around the ascending aorta and a newly developed dissecting aneurysm in remaining aorta were noted in group II. There were 6 late deaths: 2 cases in group I and 4 cases in group II. Three cases among the 6 late deaths have stigmata of Marfan`s syndrome[1 cases in group I and 2 case in group II]. There was no statistically significant difference in actuarial survival rates between group I and group II[p > 0.05]. This study suggests that non-composite supracoronary graft interposition with separate aortic valve replacement is a safe surgical technique in patients who have normal aortic annulus and normal position of coronary ostia. However in degenerative disease such as cystic medial necrosis, composite graft replacement is recommended because this procedure eliminates entire abnormal tissue.But it seems to be important that the suture technique and strict follow-up in patients with diseased aortic wall.

• Journal of Biomedical Engineering Research
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• v.22 no.5
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• pp.413-418
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• 2001

We developed shunt valves used to treat patients with hydrocephalus. The valves under development were constant Pressure type ventriculoperitoneal (VP) calves made of silicone elastomer. In vitro experiments showed that our valves had similar Pressure-flow control characteristics to the valved currently available in the market. Our valves also showed competent performance in the 28 days of continuous pumping tests acording to the IS07197 specifications. We artificially inducted hydrocephalus to a 10kg beagle do9. The size of the ventricles of the dog was substantially increased and the dog showed abnormal behavior. After our valve being implanted, the ventricles recovered regular size with the normal behavior observed in the dog. The flow orifice of the shunt valve diaphragm was in the older of 10$\mu$m during calve operation and hence the pressure-flow control characteristics tended to change by a small chance in the valve dimension. Therefore, precision design and manufacturing techniques were necessary for successful operations of the shunt valves .

• Corrosion Science and Technology
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• v.15 no.4
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• pp.182-188
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• 2016

Significant piping wall thinning caused by Flow-Accelerated Corrosion (FAC) and Erosion-Corrosion (EC) continues to occur, even after the Mihama Power Station unit 3 secondary pipe rupture in 2004, in which workers were seriously injured or died. Nuclear power plants in many countries have experienced FAC and EC-related cases in steam cycle piping systems. Korea has also experienced piping wall thinning cases including thinning in the downstream straight pipe of a check valve in a feedwater pump line, the downstream elbow of a control valve in a feedwater flow control line, and failure of the straight pipe downstream of an orifice in an auxiliary steam return line. Cause analyses were performed by reviewing thickness data using Ultrasonic Techniques (UT) and, Scanning Electron Microscope (SEM) images for the failed pipe, and numerical simulation results for FAC and EC cases in Korea Nuclear Power Plants. It was concluded that the main cause of wall thinning for the downstream pipe of a check valve is FAC caused by water vortex flow due to the internal flow shape of a check valve, the main cause of wall thinning for the downstream elbow of a control valve is FAC caused by a thickness difference with the upstream pipe, and the main cause of wall thinning for the downstream pipe of an orifice is FAC and EC caused by liquid droplets and vortex flow. In order to investigate more cases, additional analyses were performed with the review of a lot of thickness data for inspected pipes. The results showed that pipe wall thinning was also affected by the operating condition of upstream equipment. Management of FAC and EC based on these cases will focus on the downstream piping of abnormal or unusual operated equipment.

• Tribology and Lubricants
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• v.37 no.6
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• pp.246-252
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• 2021

Among the engine components of an internal combustion engine, the valve train is a series of systems that supply intake gas to the combustion chamber and operate intake and exhaust valves that discharge exhaust gas. If excessive wear occurs in the valve train system, the suction and exhaust valves do not open and close on time, which leads to abnormal combustion and exhaust gas. In this study, we conduct experiments and analyses on friction and wear characteristics of the valve train system. Moreover, we experimentally study the correlation between the pinball and pinball cap on engine oil lubrication, friction experiment, wear amount analysis, and surface analysis. Specifically, we experiment using Ball on reciprocating tribo-tester and apply commercial engine oil sold on the market engine oil. We construct the experimental conditions for each new oil and oil. Accordingly, the completed specimen was subjected to a confocal microscope to check the wear volume, observe the surface of the specimen, and confirm the elemental components using a scanning microscope (SEM) and an energy dispersion X-ray spectrometer (EDS). Through this experiment, we analyze the friction and wear characteristics of valve train components according to engine oil grade, and the obtained data serve as an effective engine oil management method.

• Journal of Chest Surgery
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• v.13 no.4
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• pp.442-447
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• 1980

A 8-year-old boy underwent surgical correction of complete transposition S.D.D. of great arteries combined with subaortic ventricular septal defect and pulmonary stenosis [infundibular and valvular]. The operation consisted of an internal baffling connecting the left ventricle to the aorta through the ventricular septal defect. The pulmonary stenosis was corrected with the method of external connection, the right ventricle to the pulmonary artery using the conduit valve [20 mm] contained Hancock due to abnormal distribution of left coronary artery of which conduit due to abnormal distribution of left coronary artery of which the circumflex branch crossed the portion of right ventricular outflow tract. This case was suitable for corrective surgery-Rastelli operation-and the patient`s condition in very good until present [post-operative 5 months].