• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.316-321
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• 2022

Since 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly, infecting millions of people worldwide. On March 11, 2020, the World Health Organization declared coronavirus disease (COVID-19) a pandemic owing to the worldwide spread of SARS-CoV-2, which created an unprecedented burden on the global healthcare system. In this context, there are increasing concerns regarding co-infections with other respiratory viruses, such as the influenza virus. In this study, clinical data of patients infected with SARS-CoV-2 and other respiratory viruses were compared with patients infected with SARS-CoV-2 alone. The hematology and blood biochemistry results of 178 patients infected with SARS-CoV-2 , who were tested on admission, were retrospectively reviewed. In patients with SARS-CoV-2 and adenovirus co-infection, C-reactive protein levels were elevated on admission, whereas lactate dehydrogenase (LDH), prothrombin time, international normalized ratio, activated partial thromboplastin clotting time, and bilirubin values were all within the normal range. Moreover, patients with SARS-CoV-2 and human bocavirus co-infection had low LDH and high bilirubin levels on admission. These findings reveal the clinical features of respiratory virus and SARS-CoV-2 co-infections and support the development of appropriate approaches for treating patients with SARS-CoV-2 and other respiratory virus co-infections.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.560-564
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• 2004

The optimal design and combustion analysis of the gas generator for Liquid Rocket Engine (LRE) were performed. A fuel-rich gas generator in open cycle turbopump system was designed for 10ton$_{f}$ in thrust with RP-1/Lox propellant. The optimal design was done for maximizing specific impulse of main combustion chamber with constraints of combustion temperature and power matching required by turbopump system. Design variables were selected as total mass flow rate to gas generator, O/F ratio in gas generator, turbine injection angle, partial admission ratio, and turbine rotational speed. Results of optimal design show the dimension of length, diameter, and contraction ratio of gas generator. Also, the combustion test was conducted to evaluate the performance of injector and combustion chamber. And the effect of the turbulence ring was investigated on the mixing enhancement in the chamber.r.

• 한국유체기계학회 논문집
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• 제8권6호
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• pp.26-32
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• 2005

1.6 MW class supersonic partial admission impulse turbine has been designed and tested in Korea Aerospace Research Institute for the liquid rocket engine application. The test has been performed using a high pressure air source facility in KARI. For the turbine power absorption, a hydraulic dynamometer has been used. Appropriate similarity relations are used for the determination of test condition. Various settings of turbine pressure ratio and rotational speed are tested to investigate global turbine characteristics. From measured data, parameters related to the turbine design are derived and validated.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.125-131
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• 2004

1.6 MW class supersonic partial admission impulse turbine has been designed and tested in Korea Aerospace Research Institute for the liquid rocket engine application. The test has been performed using a high pressure air source facility in KARI. For the turbine power absorption, a hydraulic dynamometer is used. Appropriate similarity relations are used for the determination of test condition. Various settings of turbine pressure ratio and rotational speed are tested to investigate global turbine characteristics. From measured data, Parameters related to the turbine design are derived and validated.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.839-847
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• 2004

In this study, the flow characteristics within supersonic cascades are numerically investigated by using Fine Turbo, a commercial CFD code. Cascade flows are computed for three different inlet conditions. : a uniform supersonic inlet condition, a linear nozzle and a converging-diverging nozzle located in front of cascades. The effect of inlet conditions is compared and flow characteristics including shock patterns and shock-boundary layer interaction are analyzed. Also the effect of design parameters such as pitch-chord ratio, blade angle and blade surface curvature on the flow within supersonic cascades are studied.

• 한국항공우주학회지
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• 제32권5호
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• pp.91-96
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• 2004

액체로켓 엔진에 사용되는 가스발생기를 최적설계 하였다. 추진제는 RP-1/LOx 이고, open cycle터보펌프 시스템을 사용하였으며, 가스발생기는 농후 (fuel-rich) 연소를 적용하였다. 최적설계의 목적함수는 주연소설의 비추력의 최대화이고 설계 제한조건은 가스발생기 연소 실온도와 터빈-펌프의 출력일치이다. 가스 발생기의 설계에 사용된 설계변수는 가스발생기 유량, O/F비, 터빈 노즐 입구 각, 부분분사비, 그리고 터빈 원주속도이며 이들을 이용하여 가스발생기의 열역학적 성능을 계산하였다. 그리고 설계 제한조건을 만족하면서 목적함수를 최대화 할 수 있는 가스발생기의 크기와 성능조건을 확인하였다. 설계된 가스발생기 기본형상은 연소시험에 적용된 후 최종적으로 결정된다.

• 항공우주시스템공학회지
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• 제11권1호
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• pp.8-13
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• 2017

한국형 발사체 3단 엔진용 터보펌프 터빈에 관해 성능 시험을 수행하여 성능 특성 결과를 분석하였다. 터빈은 초음속 충동형 방식의 단단 형태이며, 노즐은 시동 노즐 1개와 정상 운전용 노즐 4개로 이루어졌으며, 부분 분사 형태로 되어 있다. 한국항공우주연구원 내의 고압 공기 터빈 상사 시험 설비를 이용하여 상사 시험을 수행하였다. 시험 결과 효율은 회전수 변화에 크게 변화하며, 이에 반해 압력비 변화에는 다소 작게 변화하는 초음속 충동형 터빈의 일반적인 특성을 보이고 있다.

• Tuberculosis and Respiratory Diseases
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• 제39권4호
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• pp.343-347
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• 1992

연구배경 : 한쪽폐의 전체가 파괴되는 경우는 여러 원인이 있을 수 있다. 이중에서 폐결핵으로 인하여 만성적 염증과 섬유화등을 통하여 파괴된 경우 그 좌우 발생빈도에 차이가 있음을 보고 최근 4년간 국립 공주 결핵뱅원 흉부내과에 입원하였던 224명의 환자를 대상으로 하여 조사하였다. 방법 : 입원 당시의 흉부 방사선 소견을 4가지로 분류하고 성별, 연령, 질병기간, 세균학적 검사를 조사하였다. 결과 : 1) 남녀비는 2 : 1이고 연령은 31~40세가 67명 (30%)으로 가장 많았다. 2) 질병기간은 대부분(88%)이 3년 이상 장기간의 병력을 가지고 있었으며, 6~10년 사이가 87명(39%)로 가장 많았다. 3) 객담 검사상 대부분(80%)이 양성이었다. 4) 흉부 방사선 소견상 좌측폐 전체가 파괴되고 우측에 부분적 병변을 가진 경우가 181명(81%)으로 가장 많았으며 우측폐 전체가 파괴되고 좌측에 부분적인 병변을 가진 경우 31명(14%), 좌측 전폐 파괴만 있는 경우 11명(5%) 그리고 우측 전폐 파괴만 있는 경우 1명 이었다. 5) 성별, 연령, 질병기간 그리고 객담 검사와 흉부 방사선 소견 사이에는 뚜렷한 차이점을 발견할 수 없었다. 결론 : 본 조사결과 폐결핵 환자에서 한쪽폐의 전체가 파괴되는 경우 주로 좌측임을 알게 되었다. 이는 폐결핵 자체의 직접전파, 폐결핵 합병증과 그에 따른 2차적 변화, 기관지 결핵 등에 있어서 좌측폐의 파괴가 더 용이하기 때문으로 생각된다. 질병 기간에 따른 소견 및 질병 초기부터의 변화과정에 대하여 더 많은 연구가 필요 하라라 사료된다.

• 대한임상독성학회지
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• 제12권2호
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• pp.92-96
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• 2014

Dabigatran is the first oral direct thrombin inhibitor approved by the US Food and Drug Administration (FDA) for prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. Because dabigatran is excreted mainly by the kidneys, serum levels of dabigatran can be elevated to a supratherapeutic range in patients with renal failure, predisposing to emergent bleeding. We describe the case of a 66-year-old man taking dabigatran 150 mg twice daily for atrial fibrillation and cerebral infarction who presented with hematochezia and disseminated intravascular coagulation. Laboratory evaluation showed a hemoglobin level of 6.3 g/dL, platelets of $138,000/mm^3$, activated partial thromboplastin time (aPTT) of 10 s, and an international normalized ratio (INR) of 8.17. Colonoscopy showed a bleeding anal fissure. Hemostasis was provided by hemoclips and packed red blood cells and fresh frozen plasma were transfused. Since then, there was no further hematochezia, however, bleeding including oral mucosal bleeding, hematuria, and intravenous site bleeding persisted. At presentation, his serum creatinine was 4.96 mg/dL (baseline creatinine, 0.9 mg/dL). Dabigatran toxicity secondary to acute kidney injury was presumed. Because acute kidney injury of unknown cause was progressing after admission, he was treated with hemodialysis. Fresh frozen plasma transfusion was provided with hemodialysis. At 15 days from admission, there was no further bleeding, and laboratory values, including hemoglobin, partial thromboplastin time, and prothrombin time were normalized. He was discharged without bleeding. After 2 months, he undergoes dialysis three times per week and no recurrence of bleeding has been observed.

• 대한임상독성학회지
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• 제14권2호
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• pp.92-99
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• 2016

Purpose: The use of flumazenil administration in the emergency department is still controversial because of concerns about adverse effects. The present study was conducted to re-evaluate the risk-benefit ratio associated with flumazenil administration to patients suspected of having acute hypnotics and sedatives poisoning in the emergency department. Methods: A retrospective chart review study was conducted for patients whose final diagnoses were "poisoning" and "benzodiazepine" or "sedatives-hypnotics" from Mar. 2006 to Feb. 2015. The basal characteristics of the patients, including past medical history, ingredients and dose of ingested drug and co-ingested drugs were investigated. For patients administered flumazenil, responsiveness and time from admission to flumazenil administration were investigated with supplement. All collected data were analyzed in aspect terms of risk/benefit. Results: A total of 678 patients were included in our study. Benzodiazepine was the most common sedative/hypnotic drug prescribed, and the frequency of prescription continuously increased. The proportion of TCA as co-ingestion decreased from 13.1% to 3.9% in patients with acute sedative/hypnotic poisoning. Flumazenil was administered to 55 patients (8.1%), of which 29 patients (52.7%) were applied to contraindications. Fifty-three patients (96.4%) showed positive responsiveness, including partial responsiveness after flumazenil administration. No severe adverse events were identified. Conclusion: Based on the current trends in prescription patterns for sedative/hypnotic drugs, increased use of non-TCA antidepressants, and responsiveness to administration of flumazenil, benefit seemed weighted more in this study, although the observed benefits were based on limited results. Further prospective multicenter studies will be needed to optimize benefit-risk ratio.