• Journal of Chest Surgery
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• v.44 no.6
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• pp.423-426
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• 2011

We report on two women who underwent myocardial revascularization associated with antiphospholipid syndrome (APS) with different pathogenic patterns. The first woman presented with acute myocardial infarction, and preoperative angiograms demonstrated rapidly progressing coronary lesions, presumptive unstable plaque, and dissection. Operative findings, however, showed fresh thrombi in the coronary arteries, and she was diagnosed postoperatively as having APS. Her one-year angiogram demonstrated improved coronary lesions and a competitive flow pattern in the grafts. The second woman presented with unstable angina and had been treated for systemic lupus erythematosus and secondary APS for more than 14 years. She underwent myocardial revascularization due to accelerated coronary atherosclerosis. Her one-year angiogram demonstrated patent grafts.

• Journal of Chest Surgery
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• v.42 no.2
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• pp.252-255
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• 2009

We performed a hybrid procedure for a 58-year-old man with coronary artery disease and a left subclavian artery stenosis. He underwent left subclavian artery stenting and off-pump coronary artery bypass surgery, including grafting the in situ left internal mammary artery to the left anterior descending coronary artery. The post-operative coronary angiogram and computed tomography showed good patency of the graft and stent. He discharged at postoperative 8 days and he has been followed up for six month with an excellent clinical condition.

• Journal of Chest Surgery
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• v.40 no.11
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• pp.773-776
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• 2007

A 47-year-old male with hypertension, diabetes mellitus and heavy smoking, but no anginal symptoms, presented with claudication of the lower extremities. Extremity angiography with coronary angiography revealed peripheral arterial lesions including a left subclavian artery occlusion with coronary artery disease. The patient underwent an initial off-pump coronary artery bypass with an ascending aorto-axillary bypass. The right internal mammary artery was anastomosed to the left anterior descending coronary artery. The greater saphenous vein graft was connected from the ascending aorto-axillary bypass graft to the diagonal branch. At postoperative day 18, femorofemoral and bilateral femoropopliteal bypasses were performed. We report a case of the combined repair of coronary artery disease and a left subclavian artery occlusion.

• Journal of Chest Surgery
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• v.46 no.1
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• pp.84-87
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• 2013

A 60-year-old man visited the outpatient clinic due to one month of recurrent exertional chest pain. Eleven years earlier he had undergone off-pump coronary artery bypass grafting using bilateral internal thoracic artery (ITA) Y-composite grafts based on the left ITA. Preoperative coronary angiography showed patent distal graft anastomoses and visualized the left ITA retrogradely. The arch aortography revealed near-total occlusion of the left subclavian artery at the level of the ostium. The patient underwent left carotid-to-subclavian artery bypass grafting using a 6 mm vascular conduit. Postoperative computed tomographic angiography revealed a patent bypass conduit between the left common carotid artery and left subclavian artery. The patient was discharged on postoperative day 4 with no symptoms or signs of myocardial ischemia.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.497-504
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• 2015

Apart from hydrates, asphaltenes, and inorganic minerals, paraffinic waxes are also very important in flow assurance area. Evaluation of wax gel behavior has been important as off-shore oil recovery becomes more popular in oil production. Restart after either planned or emergency shutdown requires pump operation in high pressure since a waxy oil forms troublesome gel. In this paper, vane method is introduced to determine wax gel strength by determining yield stress. Prediction of gel strength are discussed in qualitative and quantitative manners.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.528-531
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• 2009

Transesophageal echocardiography (TEE) is widely used to evaluate the heart function and the result of surgery during a cardiac operation. The incidence of complications associated with TEE is low, yet critical complications such as lower pharyngeal injury and esophageal perforation may happen. We report hereon a case of 77-year old male patient who suffered from injury to the pyriform sinus and concurrent deep neck infection after off pump coronary artery bypass surgery and intraoperative TEE.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.520-523
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• 2009

Aortic arch aneurysm generally requires an urgent treatment due to the risk of catastrophic aortic rupture. However conventional surgery for aortic arch repair still carries significant risks of postoperative morbidity and mortality, especially in patients with old age. In an effort to correct the aortic pathology while minimizing the risks of complication, we performed a hybrid technique which comprises the off pump arch aortic stent grafting in an 86-old male patient with an aortic arch aneurysm.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.28-35
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• 2015

Thin film electronic devices which brought the current mobile environment could be fabricated only under the high quality vacuum conditions provided by high vacuum systems. Especially for the development of advanced thin film devices, constant high quality vacuum as the deposition pressure is definitely needed. For this purpose, the variable conductance throttle valves were employed to the high vacuum system. In this study, the effects of throttle valve applications on vacuum characteristics were simulated to obtain the optimum design modelling of variable conductance of high vacuum system. Commercial simulator of vacuum system, $VacSim^{(multi)}$, was used on this investigation. Reliability of employed simulator was verified by the simulation of the commercially available models of high vacuum system. Simulated vacuum characteristics of the proposed modelling were agreed with the observed experimental behaviour of real systems. Pressure limit valve and normally on-off control valve were schematized as the modelling of throttle valve for the constant process-pressure of below $10^{-3}torr$. Simulation results were plotted as pump down curve of chamber, variable valve conductance and conductance logic of throttle valve. Simulated behaviors showed the applications of throttle valve sustained the process-pressure constantly, stably, and reliably.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.4
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• pp.437-444
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• 2008

Many other countries have investigated the new backwash water treatment process to save the existing water resource. There are various methods for reusing backwash water, but the membrane system has received the most interest for its efficiency. The objective of this study was to certify the application of membrane filtration system for the backwash water treatment. The experiment equipment was composed of Lab scale tubular membrane filtration system. Generally, cross-flow operation mode is used in the tubular membrane system but cross-flow operation mode demands high electric cost mainly for the pump energy. So to cut off electric cost, dead-end operation mode was used in this experiment. Filtration and bleed operation cycle was used in this membrane system. Backwash water was concentrated during the filtration process and when backwash water reached our target suspended solid concentration, it was discharged from this system. For efficient operation of filtration and bleed, mathematical matrix was drawn up and with this matrix we could simulate various sets of filtration and bleed time.

• Journal of Chest Surgery
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• v.35 no.7
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• pp.553-555
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• 2002

Transabdominal approach in redo coronary artery bypass grafting(CABG) may avoid the risk related to repeat sternotomy. Redo CABG using this approach can be performed safely in selected cases. We report a case of redo off-pump CABG through a transabdominal approach in a 59-year-old woman with recurrent unstable angina after a previous CABG. Through a curvilinear epigastric incision, right gastroepiploic artery(RGEA) was harvested as a graft, and the RGEA-to-right coronary artery anastomosis was performed on the beating heart. A 1-day postoperative angiographic study showed the patent RGEA graft, and she was discharged on postoperative 4th day without any complication.