• Journal of Chest Surgery
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• v.39 no.12 s.269
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• pp.906-912
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• 2006

Background: Ventricular septal defect(VSD) is rare but feared complication after acute myocardial infarction. The patient could survive by surgery only, but the surgical mortality is still high. We investigate the surgical result and predictors for early surgical mortality. Material and Method: Between August 1993 and February 2006, 8 patients (male, 2: female, 6) with postinfarct VSD underwent surgical repair. Seven patients had one-vessel disease of left anterior descending artery, and 6 of them had wide extension of infarction to posterior septal wall as well as anterior septal wall of both ventricles. One patient had concomitant coronary bypass grafting to a coronary lesion unrelated to the infarction. Two patients had concomitant tricuspid annuloplasty and 1 patient mitral valvuloplasty. Result: Surgical mortality was 37.5%(3 patients). They all had only one-vessel disease of left anterior descending artery, which made extended posterior septal wall infarction as well as anterior septal wall infarction of both ventricles. In preoperative M-mode echocardiographic study of left ventricle, they had lower ejection fraction than survivors($34.9{\pm}4.2\;vs.\;54.8{\pm}12.3$; p=0.036). Conclusion: Most of patients with postinfarction VSD had one-vessel disease of left anterior descending artery. Early surgical mortality occurred in the patients with poor ejection fraction of left ventricle and the wide anterior septal wall infarction extending to the posterior septum.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.4
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• pp.361-367
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• 2013

Many of the nuclear power plant pipe is used in high temperature and high pressure environment. Wall thinning frequently caused by the corrosion. These wall thinning in pipe is expected gradually increase as nuclear power become superannuated. Therefore there is need to evaluate wall thinning in pipe and corrosion defect by non-destructive method to prevent the accident of the nuclear power facility due to pipe corrosion. Especially for real-time assessment of the wall thinning that occurs in nuclear power plant pipe, the laser ultrasonic technology can be measured even in hard-to-reach areas, beyond the limits of earlier existing contact methods. In this study, the optical method using laser was applied for non-destructive and non-contact evaluation. Ultrasonic signals was acquired through generating ultrasonic by pulse laser and using laser interferometer. First the ultrasonic signal was detected in no wall thinning in pipe, then a longitudinal wave velocity was measured inside of pipe. Artificial wall thinning specimen compared to 20, 30, 40 and 50% of thickness of the pipe was produced and the longitudinal wave velocity was measured. It was possible to evaluate quantitatively the wall thinning area(internal defect depth) cause it was able to calculate the thickness of each specimen using measured longitudinal wave velocity.

• Journal of Power System Engineering
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• v.8 no.3
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• pp.52-57
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• 2004

A new non-destructive inspection technique has been developed. One characteristic of the technique is that defects are visualized by laser ray. Magnetic domains and domain walls of a magneto-optical sensor(MO sensor) are varied by the magnetic flux leaked by defects, and the variations are observed by the reflected light of the laser ray. The information of defect can remotely be inspected by this technique in a real time. This paper describes the results estimated on the 2-dimensional surface defects and opposite-side defects in a ferromagnetic material and the natural surface defect in a clutch disk wheel. The light region of a visible image and the magnitude of a reflected light increases as the input current of the magnetizer increases. The natural surface defect, that has not the width of crack's open mouth, can be also visualized like as 2-dimensional artificial defects.

• Journal of Chest Surgery
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• v.26 no.4
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• pp.312-315
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• 1993

The malformation consisted of persistent left SVC terminating in left atrium, absence of coronary sinus, and atrial septal defect is considered as a developmental complex anomaly. We observed such a case associated with partial atrioventricular canal defect and common atrium. We operated it by intraatrial roofing [tunneling] along its course of the posterior wall of the left atrium using bovine pericardial patch, which was designed to contain some of thebesian veins, thereby, left superior vena caval and some coronary venous blood would be drained into venous side. Associated lesions were also corrected.

• Journal of Chest Surgery
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• v.22 no.4
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• pp.655-660
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• 1989

The unroofed coronary sinus syndrome is a spectrum of cardiac anomalies in which part or all the common wall between the coronary sinus and the left atrium is absent. This defect is part of a developmental complex which includes absence of the coronary sinus and termination of a persistent left superior vena cava in the left atrium. Recognition of this complex is important so that interruption or diversion of the left superior vena cava may be done to prevent subsequent central nervous system complications. Surgical correction uses an intraatrial baffle to divert flow from the left superior vena cava to right atrium and to close the atrial septal defect. This report describes a 7 years old female patient in whom the left superior vena cava was identified preoperatively and the complex [unroofed coronary sinus syndrome, common atrium, mitral valve cleft] recognized at the time of operation. Surgical correction, following repair of cleft mitral valve, utilized a Dacron patch baffle to route the left caval blood to the right atrium and included closure of the atrial septal defect

• Journal of Chest Surgery
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• v.28 no.9
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• pp.857-860
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• 1995

In a 53-year old male with post-infarction ventricular septal defect [VSD , owing to an acute exacerbation of pulmonary edema, respiratory failure developed, and the ventilatory support and intraaortic balloon counterpulsation [IABP were applied. At the following day, operation was performed with the aid of IABP. Under the cardioplumonary bypass, he underwent infarctectomy, trimming of VSD margin, patch closure of VSD and infarctectomy site. Left ventricular free wall rupture was detected during operation, which was confined with pericardial adhesion. Post-operative course was uneventful, and he could be discharged with minimal degree of dyspnea [NYHA class II .

• Journal of Chest Surgery
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• v.24 no.2
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• pp.206-211
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• 1991

Interruption of the aortic arch may be defined as discontinuity of the aortic arch in which either an aortic vessel or a patent ductus arteriosus supplies the descending aorta. This anomaly is a rare congenital malformation that usually occurs with severe associated intracardiac congenital anomalies, such as ventricular septal defect, patent foramen ovale and abnormal arrangement of the brachiocephalic arteries. Rarely, transposition of the great vessel, truncus arteriosus are coexistent. We experienced a case of the interrupted aortic arch [Type A] associated with VSD, PDA and patent foramen ovale in a 16 years old female. One stage total correction was done under profound hypothermia with total circulatory arrest. Aortic continuity was established using patent ductus arteriosus with anterior wall of main pulmonary artery, which was anastomosed obliquely to anteromedial side of the ascending aorta. Ventricular septal defect was closed using Dacron patch and patent foramen ovale was closed directly. Postoperative course was uneventful, except mild hoarseness.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.3
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• pp.731-740
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• 1995

The objective of this paper is to develop defect assessment technology for integrity evaluation of CANDU pressure tubes. In fracture mechanics analysis, three-dimensional and two-dimensional (line-spring model) finite element analyses were performed to obtain the stress intensity factor for axial and circumferential surface cracks. In leak before break (LBB) analysis, heat transfer analyses for through-wall cracks were performed by considering the cooling effect and the LBB application time was computed. It was shown that the analytical results obtained in this study provide less-conservative but accurate solution for defect assessment of CANDU pressure tubes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.141-142
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• 2008

Single crystal $ZnIn_2S_4$ layers were grown on thoroughly etched semi-insulating GaAs(100) substrate at $450^{\circ}C$ with hot wall epitaxy (HWE) system by evaporating $ZnIn_2S_4$ source at $610^{\circ}C$. The temperature dependence of the energy band gap of the $ZnIn_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g$(T) = 2.9514eV - ($7.24\times10^{-4}$ eV/K)$T^2$/(T + 489 K). After the as-grown $ZnIn_2S_4$ single crystal thin films was annealed in Zn-, S-, and In-atmospheres, the origin of point defects of $ZnIn_2S_4$ single crystal thin films has been investigated by the photoluminescence(PL) at 10 K. The native defects of $V_{Zn}$, $V_s$, $Zn_{int}$, and $S_{int}$, obtained by PL measurements were classified as a donors or acceptors type. And we concluded that the heat-treatment in the S-atmosphere converted $ZnIn_2S_4$ single crystal thin films to an optical p-type. Also, we confirmed that In in $ZnIn_2S_4$/GaAs did not form the native defects because In in $ZnIn_2S_4$ single crystal thin films existed in the form of stable bonds.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.98-99
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• 2008

To obtain the single crystal thin films, $AgGaSe_2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperatures were $630^{\circ}C$ and $420^{\circ}C$, respectively. The temperature dependence of the energy band gap of the $AgGaSe_2$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g$(T) 1.9501 eV - ($8.79\times10^{-4}$ eV/K)$T^2$/(T + 250 K). After the as-grown $AgGaSe_2$ single crystal thin films was annealed in Ag-, Se-, and Ga-atmospheres, the origin of point defects of $AgGaSe_2$ single crystal thin films has been investigated by the photoluminescence(PL) at 10K. The native defects of $V_{Ag}$, $V_{Se}$, $Ag_{int}$, and $Se_{int}$ obtained by PL measurements were classified as a donors or acceptors type. And we concluded that the heat-treatment in the Ag-atmosphere converted $AgGaSe_2$ single crystal thin films to an optical p-type. Also, we confirmed that Ga in $AgGaSe_2$/GaAs did not form the native defects because Ga in $AgGaSe_2$ single crystal thin films existed in the form of stable bonds.