• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.1
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• pp.11-19
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• 2001

To establish optimum cycle of the inverter-driven heat pump with a variation of frequency, the bypass orifice, which was a short tube haying a bypass hole in the middle, was designed and tested. Flow characteristics of the bypass orifice were measured as a function of orifice geometry and operating conditions. Flow trends with respect to frequency were compared with those of short tube orifices and capillary tubes. Generally, the bypass orifice showed the best flow trends among them. and it would enhance the seasonal energy efficiency ratio of an inverter heat pump system, Based on experimental data, a semi-empirical flow model was developed to predict mass flow rate through bypass orifices. The maximum difference between measured data and model`s prediction was within $\pm$5%.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.1
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• pp.109-116
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• 1999

To establish optimum cycle of the inverter-driven heat pump with a variation of frequency, the bypass orifice, which is a short tube having a bypass hole in the middle, was designed and tested. Flow characteristics of the bypass orifice were measured as a function of orifice geometry and operating conditions. Flow trends with respect to frequency were compared with those of short tube orifices and capillary tubes. Generally, the bypass orifice showed the best flow trends among them, that will enhance the seasonal energy efficiency ratio of an inverter heat pump system. Based on experimental data, the semi-empirical flow model was developed to predict mass flow rate through bypass orifices. The maximum difference between measured data and model's prediction was within ${\pm}5%$.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.4
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• pp.390-396
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• 2004

A double-inlet pulse tube refrigerator was fabricated as a U-shape with $\Phi$19.0 mm${\times}$125 mm regenerator packed by #200 stainless steel mesh and $\Phi$12.7 mm${\times}$125 mm pulse tube. A pressure sensor was installed at the inlet of the regenerator and a differential pressure sensor was installed across the bypass. Amplitude of the pulsating pressure was independent of the opening of the orifice and the bypass valves. Helium flow through the orifice and the bypass was calculated based on the measured pressure. Energy loss through the orifice and the bypass was evaluated with the measured pressure and the calculated helium flow rate. The energy loss, which is equivalent to the refrigeration capacity at the cold end of the ideal pulse tube refrigerator, was mainly generated through the orifice. It was proportional to the opening of the orifice valve, but the real refrigerator displayed the best performance at the optimized opening of the orifice valve. This optimized performance of the tested pulse tube refrigerator can be explained by additional refrigeration losses. As an example, the shuttle heat transfer loss of the pulse tube was calculated from the measured experimental data.

• Journal of Chest Surgery
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• v.16 no.2
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• pp.175-183
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• 1983

Ventricular aneurysm which was first described by John Hunter on 18th century, has been experienced by many surgeons after successful using of cardiopulmonary bypass by Cooley on 1958. According to Gorlin, the definition of ventricular aneyrysm is portion of the ventricle which is not motile at systole (akinesis) or which has paradoxical dilatation at systole(dyskinesis). The ventricular aneurysm is classified to anatomical and functional. The anatomical ventricular aneurysm is devided into true or false again. Average age incidence is ranged from 49 to 60 and male predominance is reported. The cause is ischemic coronary artery disease in almost cases but hypertropoc cardiomyopathy, congenital abscence of myocardium, complication after mitral valvular replacement and trauma may also cause the ventricular aneurysm. Angina pectoris and congestive heart failure are most common clinical manifestations Ventricular tachycardia and systemic embolization are also complained. Using cardiopulmonary bypass, aneurysmectomy alone or combination with coronary artery revasculization are currently done for surgical treatment with steady improvenment of mortality. The first patient was 33 years old man who had true type of ventricular aneurysm on inferior wall the left ventricle near apex with protruded huge organized thrombus. The thromboembolic phenomenon was noted on both lower extremities. Under cardiopulmonary bypass, aneurysmectomy and thrombectomy were done. The aneurysmal orifice was repaired with Teflon buttless suture. The second patient was 30 years old female who had large true type of ventricular aneurysm on inferior wall of the left ventricle. Under cardiopulmonary bypass, aneurysmectomy with repair of aneurysmmal orifice defect by means of double layered Dacron patch was done with reinforce by outer silastic sheet covering. She was discharged from hospoital at post op. 15th day uneventfully.

• Journal of Chest Surgery
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• v.16 no.1
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• pp.30-33
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• 1983

Truncus Arteriosus is an uncommon congenital anomaly which is now correctable surgically in patients with favorable anatomy. A case of a 9 month old male with truncus arteriosus, type II, is reported operation was done on cardiopulmonary bypass with deep hypothermia and circulatory arrest. The pulmonary arteries were not disconnected from the truncus, and the pulmonary common orifice was closed with a Dacron patch through anterior truncotomy and, for the distal anastomosis, the left pulmonary artery was opened near the common orifice. Continuity between the right ventricle and the left pulmonary artery was established with a valved conduit [Ionescu-Shiley, 14mm]. The postoperative course was excellent and uneventful.

• Journal of Chest Surgery
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• v.25 no.12
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• pp.1461-1464
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• 1992

Cor triatriatum is rare congenital heart disease which is another variant of anomalous pulmonary venous return. It has abnormal fibromuscular diaphragm between true left atrium and accessary chamber which has one or more orifice to the left atrium. In classic form, the patient dies within several months after birth due to pulmonary hypertension inevitably, so it is rarely found in adult. With priopertive echocardiogram and cineangiogram we had two impressions, left atrial cystor cortriatriatum. At operative finding, there was no visible combined anomaly except accessary chamber which received all pulmonary venous return that drained into the left atrium through small calcified orifice. The operation was performed by simple resection of the diaphragm under cardiopulmonary bypass. The postope rative course was uneventful.

• Journal of Chest Surgery
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• v.10 no.1
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• pp.164-172
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• 1977

This is a report of a case in which a left atrial myxoma was successfully removed by total cardiopulmonary bypass with total hemodilution and moderate hypothermia. The patient was a 17 old girl with mitral valvular symptoms that occured suddenly three months prior to operation. After the onset of symptoms. it was progressively aggravated to serious general condition. The preoperative diagnosis of left atrial tumor was made from echocardiography. and the tumor was confirmed as myxoma by the histopathological examination of the tumor tissue removed during operation. The myxoma was unusually originated from posterior wall of the left atrium. which was located between drainage orifices of right and left pulmonary veins, The tumor developed in the left atrial cavity and one of the polypoid processes of the myxoma was prolapsed into the the left ventricle through the mitral orifice. Following operation. there was no evidence for peripheral vascular embolism, and all valvular symptoms disappeared. The postoperative course was uneventful.

• Journal of ILASS-Korea
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• v.7 no.1
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• pp.36-42
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• 2002

The objective of this investigation was to obtain an excellent spray at the low injection pressure. When cavitation occurred in the nozzle hole the atomization of the liquid jet enhanced considerably. In this experiments, a acrylic nozzle which was installed the gap and installed the bypass in the nozzle hole was used to enhance the atomization of the liquid jet at the few injection pressure. The liquid flow in the nozzle hole was photographed by a transmitted light using a micro flash. The spray angle was measured by macroscope images of PMAS and the Sauter mean diameter was measured by PDA system. The pressure of the notate hole was measured by pressure transducer. It was found that enhanced atomization of the liquid jet at the low injection pressure was obtained by installing the gap and the bypass at the single hole nozzle.

• Journal of Chest Surgery
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• v.24 no.11
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• pp.1133-1137
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• 1991

Congenital coronary arteriovenous fistula is relatively uncommon and often associated with additional congenital and acquired heart disease. If coronary arteriovenous fistula is suspected, the diagnosis can be made readily by cardiac catheterization and selective coronary arteriography. Surgical treatment is very satisfactory, with a low mortality and apparent good long term result. Recently, we experienced one case of congenital coronary arteriovenous fistula which was associated with aortic stenosis and regurgitation. The tortuous fistula tract was noted between the left anterior descending coronary artery and the main pulmonary artery. Under the cardiopulmonary bypass, aortic valve replacement[Carbomedics 23mm] and suture closure of the draining orifice of coronary arteriovenous fistula in the main pulmonary artery just above the pulmonary valve were performed, Postoperative hospital course was uneventful and the patient was discharged postoperative 9th day without any problems.

• Fire Science and Engineering
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• v.27 no.3
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• pp.30-37
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• 2013

The ultimate purpose of the present study is to secure a effective method for foam liquid discharge when the mixing ratio deviates from the permissible range due to a decrease in the bypass flow rate resulting from a decrease in the cross sectional area of the foam liquid piping ranging from the branching header of one foam proportioner to the branching headers of multiple branching foam fire-extinguishing systems in the region for fire extinguishing and then to the standpipe at the lower part of the storage tank when a fire occurred in a combustible tank. To this end, the cause of mixing ratio variations following changes in the flow rates of existing foam fire extinguishing systems was analyzed, methods for compensation for constant mixing ratios were investigated, and it was proved that metering orifice replacements that could expand the cross sectional area of the stock solution inhaling piping was the most effective way for the improvement of form fire extinguishing systems' mixing ratios through foam proportioner venturi, foam chamber orifice, and metering orifice replacement experiments.