• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.17-22
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• 2002

A conventional silica gel/water adsorption chiller has been analyzed numerically. A novel non-dimensional mathematical model has been presented to analyze the design effect of different components of an adsorption chiller. The design parameters of this system are characterized by the number of transfer unit, NTU, of different components and the inert material alpha number, ${\alpha}$of different components of the systems. Results show that condenser NTU$\sub$a/ has the most influential effect on the system performance, which is fellowed by absorber NTU$\sub$e/. It is also seen that coefficient of performance (COP) and non-dimensional specific cooling capacity increases with the increase of NTU$\sub$a/ and NTU$\sub$e/, but decreases with the increase of inert material alpha number. A thermo-economic data of the adsorption chiller and some other heat pump systems those are in practical operation are also presented.

• Journal of Chest Surgery
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• 제44권6호
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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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• 제42권2호
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• pp.252-255
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• 2009

58세 남자 환자가 좌쇄골하동맥협착이 동반된 관상동맥 질환으로 하이브리드술식을 시행받았다. 쇄골하동맥에 대한 스텐트 삽입과 좌내흉동맥의 좌전하행지 문합을 포함한 심폐 바이패스 없이 관상동맥 우회술을 시행하였다. 수술 후 시행한 관상동맥 조영술과 컴퓨터 단층촬영(CT)상에서 이식편의 개방성은 양호하였고 스텐트의 삽입부위는 적절한 것으로 보였고 개방성도 양호하였다. 술 후 8일째 퇴원하였고, 현재 6개월째 외래 경과관찰 중이다.

• Journal of Chest Surgery
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• 제40권11호
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• pp.773-776
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• 2007

47세 남자 환자로 양측 하지의 파행을 주소로 내원하였는데 심한 흡연력, 당뇨와 고혈압을 가지고 있었다. 평소 허혈성 심질환의 증상과 뇌혈류의 역류로 인한 증상은 없었지만 상 하지 혈관조영술과 동시에 시행한 관상동맥조영술 검사에서 좌측쇄골하동맥 폐색을 포함한 말초혈관질환과 관상동맥에 심한 협착이 관찰되었다. 수술은 좌측 늑강을 경유한 상행대동맥-좌액와동맥 혈관우회술을 시행 후 우내흉동맥을 좌전하행지에 문합하고 복재정맥을 사선지와 인조혈관에 문합하였다. 하지 말초혈관의 폐색은 술 후 18일에 혈관우회술로 교정되었고 결과는 양호하였다.

• Journal of Chest Surgery
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• 제46권1호
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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.

• 한국응용과학기술학회지
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• 제32권3호
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• pp.497-504
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• 2015

심해유전개발 중 원유의 흐름보증과 관련하여 하이드레이츠, 아스팔텐, 무기물 침전 등이 주된 관심분야가 될 수 있으며, 특히 왁스에 대해서도 그 특성을 이해하는 것이 중요하다. 원유흐름 중단으로 인한 왁스가 젤을 형성하였을 경우에는, 원유의 흐름을 재시작하기 위해서는 높은 압력의 펌프를 가동해야 하는 어려움이 있다. 본 연구에서는 베인 레오미터를 사용하여 왁스 젤의 항복응력 측정을 통한 왁스 젤의 강도를 측정하고 예측하였다. 또한, 왁스 젤의 강도측정을 통해서 정성적, 정량적인 예측을 시도하였다.

• Journal of Chest Surgery
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• 제42권4호
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• pp.528-531
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• 2009

경식도 초음파는 심장수술에서 비교적 안전하게 수술 중 심장의 기능 및 수술 결과를 평가할 수 있어 그 이용이 일반화되고 있으며, 경식도 초음파 관련 합병증은 드물지만 하인두 손상이나 식도 천공 등 위험한 합병증이 생길 수 있다. 폐부종을 동반한 심근경색으로 진단받은 77세 남자환자에서 심폐 바이패스를 사용하 않는 관상동맥우회술 시행 후, 수술 중 경식도 초음파 시술과 관련되어 발생한 것으로 추정되는 pyriform sinus 천공 및 이에 동반된 경부 심부감염을 경험하여 보고하는 바이다.

• Journal of Chest Surgery
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• 제42권4호
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• pp.520-523
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• 2009

대동맥궁 대동맥류는 파열의 위험성으로 인해 적극적이며 응급에 준하는 치료가 필요하다. 그러나, 전통적인 방법의 대동맥궁 치환술은 나이가 많거나, 여러 질환이 동반된 경우 수술 후 생길 수 있는 위험 및 합병증이 높아 수술을 쉽게 시행하기 어렵다. 저자들은 대동맥궁 대동맥류를 가진 86세 남자환자에게 일반적인 수술이 아닌 Hybrid수술(심폐기를 사용하지 않은, 혈관 내 스텐트 그라프트 삽입술 및 탈분지 혈관 연결)을 시행하여 성공하였기에 문헌고찰과 함께 보고하는 바이다.

• International Journal of Internet, Broadcasting and Communication
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• 제7권2호
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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.

• 상하수도학회지
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• 제22권4호
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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.