• Journal of Chest Surgery
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• v.33 no.8
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• pp.648-654
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• 2000

Background: Cardiopulmonary bypass during open heart surgery causes systemic inflammatory respose. IL-10 is an anti-inflammatory cytokine that inhibits inflammatory process and protects organ function by down regulation of pro-inflammatory cytokine release and maintenance of blood level balance with pro-inflammatory cytokines. Mateial and Method: Plasma IL-10 levels were measured and analyzed in 22 patients who underwent open heart surgery (11 cases of coronary artery bypass graft, 11 cases of valve replacement) under cardiopulmonary bypass since 1988 January to July at Department of Thoracic and Czardiovascular surgery, Yeungnam University Hospital. 1g of methylprednisolone was administrated to thirteen patients randomly. Blood samp.es were taken and collected at the time of induction of anesthesia, 10 min before cardiopulmonary bypass, 10 min after starting of CPB, 10 min aftr aortic cross clamping, 10 min after ACC release, and 10 min, 2 hours, and `5 hours after CPB respectively. The plasma levels of IL-10 were determined by enzyme-linked immunosorbent assays(ELISA). Wilcoxon-Raule Sum test was used for statistical analysis. Result: In all 22 patients, cardiopulmonary bypass time was used for statistical analysis. Result: In all 22 patients, cardiopulmonary bypass time was 171$\pm$41.4 min and aortic cross clamp time was 118$\pm$36.5 min. Peak IL-10 level was achieved at 10 min after ACC(361.0$\pm$52.81pg/ml) and was decreased sharply at 2 hours after CPB. Peak IL-10 level was correlated positively with aortic cross clamp time(p=0.011); however, it did not correlated with bypass time(p=0.181). In valve replacement group, mean IL-10 level at peak point was 567.89$\pm$107.69 pg/ml and was significantly higher than that of coronary artery bypass group(205.67$\pm$192.70 pg/ml)(p<0.001). ACC time in valve replacement group was significantly longer than that of coronary artery bypass group(p<0.01), however, bypass time was not(p=0.212). Thirteen patients with steroid pretreatment before starting of CPB showed relatively higher plasma IL-10 level than in control group, however, no statistical significance was noted(p=0.19). Conclusion: plasma level of IL-10 was increased in association with cardiopulmonary bypass and revealed peak at 10 min after ACC release. IL-10 level was correlated positively with ACC time. Therefore, systemic inflammatory respeonse in association with cardiopulmonary bypass could be decreased by reducing ACC time during cardiac surgery.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.693-696
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• 2003

Hermetic Compressor circulates refrigerant with constant flow rate regardless of operation condition. so, at the operating condition requiring low cooling capacity, too much refrigerant flow deteriorates seasonal energy efficiency ratio(SEER). In this reason, modulated compressor is needed to improve SEER. Among many types of modulated compressor, non-inverter type modulated compressor is required for its low cost and easy to development. In the modulated scroll compressor by bypass method, EER steeply decreases for many loss like re-compression, changes of volume ratio, decrease of motor efficiency by torque variation. So. the range of modulation ratio for optimized SEER must be selected accompany with air conditioner set development.

• Journal of Chest Surgery
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• v.29 no.11
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• pp.1267-1269
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• 1996

Coronary artery bypass grafting without cardiopulmonary bypass is now one of accepted technique of myocardial revascularization. This technique is an alternative method for patients with lesions in the left anterior descending coronary artery and right coronary artery. We report a case of coronary artery bypass grafting without cardiopulmonary bypass or cardiac arrest.

• Transactions on Electrical and Electronic Materials
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• v.15 no.5
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• pp.279-283
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• 2014

In this paper, we present an economical and practical standard to install a bypass diode in a thin-film PV module. This method helps to reduce heat generation and to prevent module degradation due to excess current from reverse bias. The experimental results confirm that for different numbers of solar cells, there is a relation between the excess reverse current and the degradation of solar cells in a-Si:H modules. The optimal number of solar cells that can be connected per bypass diode could be obtained through an analysis of the results to effectively suppress the degradation and to reduce the heat generated by the module. This technique could be expanded for use in high power crystalline Si PV modules.

• Journal of Korean Neurosurgical Society
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• v.48 no.2
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• pp.177-180
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• 2010

Giant serpentine aneurysms are rare and have distinct angiographic findings. The rarity, large size, complex anatomy and hemodynamic characteristics of giant serpentine aneurysms make treatment difficult. We report a case of a giant serpentine aneurysm of the right middle cerebral artery (MCA) that presented as headache. Treatment involved a superficial temporal artery (STA)-MCA bypass followed by aneurysm resection. The patient was discharged without neurological deficits, and early and late follow-up angiography disclosed successful removal of the aneurysm and a patent bypass graft. We conclude that STA-MCA bypass and aneurysm excision is a successful treatment method for a giant serpentine aneurysm.

• Journal of Chest Surgery
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• v.17 no.2
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• pp.189-196
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• 1984

Although the conventional methods of cardiopulmonary bypass for open heart surgery have been employed, it has been usual method to repair of congenital heart disease in infancy using deep hypother-mia and circulatory arrest technique. In 1980, we reported total correction of congenital heart disease using surface induced hypothermia-total circulatory arrest and rewarming with limited cardiopulmonary bypass. in 1981, three patients below 10 kilogram, who had ASD and PDA, and two of VSD with pulmonary hypertension were operated on using simple deep hypothermia without cardiopulmonary bypass. During surface cooling, there were no ventricular fibrillation and arrhythmia. There were no difficulties to resuscitate the heart. Postoperative respiratory and neurologic complication were not occurred. Follow up examination for two to three years gave no evidence of cerebral damage due to circulatory arrest.

• Journal of Chest Surgery
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• v.20 no.1
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• pp.187-190
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• 1987

The Saphenous vein is still the graft of choice for bypass of small calibered peripheral arteries, and many recent studies revealed that the "In Situ" technique had higher rate of long term patency than the conventional "reversed" one. A 71-year-old male who had atherosclerotic obstruction in the superficial femoral and popliteal trifurcation underwent In Situ saphenous vein arterial bypass. The saphenous vein is exposed by a long medial skin incision over the course of the vein. All branches of vein are ligated. A olive-tipped metal needle is introduced into the vein from above and everts the valves. The patient has been followed for 2 months after operation. The graft remained pulsatile and the gangrenous areas on the toe proceeded to heal. We think In situ vein bypass offers an excellent and safe method of revascularization of the arterial occlusion below the knee although it is technically demanding and the time consuming. time consuming.

• Journal of Chest Surgery
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• v.26 no.12
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• pp.950-954
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• 1993

Two patients with chronic Budd-Chiari syndrome resulting from segmental obstruction of the inferior vena cava underwent operation. There were 1 man and 1 woman. The obstructed segment was directly visualized by a transthoracic, transdiaphragmatic, retroperitoneal approach. In these two cases, severe segmental obstruction of the inferior vena cava was observed just above the right hepatic vein. These patients underwent successful retrohepatic cavoatrial bypass with a polytetrafloroethylene [PTFE] graft [ 16mm plain and 16mm ringed graft ]. There were no operative mortality and postoperative complication. These patients have been followed up for 6months and 36months without evidence of re-obstruction. When there is a severe stricture of the IVC with hepatic veins draining freely into the obstructed segment of the IVC, a dorsal cavoatrial bypass with a PTFE graft, preferably ringed, is the method of choice.

• Nuclear Engineering and Technology
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• v.34 no.5
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• pp.421-432
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• 2002

As one of the advanced design features of the APR1400, direct vessel injection (DVI) system is being considered instead of conventional cold leg injection (CLI) system. It is known that the DVI system greatly enhances the reliability of the emergency core cooling (ECC) system. However, there is still a dispute on its performance in terms of water delivery to the reactor core during the reflood phase of a large-break loss-of-coolant accident (LOCA). Thus, experimental validation is under progress. In this paper, test results of direct ECC bypass performed in the steam-water test facility tailed MIDAS (Multi-dimensional Investigation in Downcomer Annulus Simulation) are presented. The test condition is determined, based on the preliminary analysis of TRAC code, by applying the ‘modified linear scaling method’with the l/4.93 length scale . From the tests, ECC direct bypass fraction, steam condensation rate and information on the flow distribution in the upper annulus downcomer region are obtained.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1664_1665
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• 2009

Many years ago, most of thermal power plants built in this country were of subcritical pressure, of medium or small size, of constant pressure operations and of drum type steam generators with circulation type boilers. But, nowadays almost all of them were of high efficiency, of supercritical pressure, of big capacity, of sliding pressure operations, and of once through type steam generator. It has such advantage as the reduction of startup duration, but it control system and operation method are very complicated. It has a big difference in operation method of turbine and boiler. The feedforward control needs to be introduced to prevent such problems as thermal shock during the transit from normal operation into bypass operation. This paper introduces the turbine control and turbine bypass control during startup of thermal power plants.