연소모델 변화에 따른 가스터빈 엔진 연소기의 열유동 해석

구자예,노현석 한국 항공대학교 항공산업기술연구소 1999 航空宇宙産業技術硏究所 硏究誌 Vol.9 No.-

본 연구는 실험용 가스터빈 엔진용 연소기에 대하여 다양한 연소 모델을 적용한 수치 해석적인 연구를 실시하여 실험 측정치와 해석 결과를 온도, 화학종 농도, 속도 분포에 대하여 비교 분석하였다. 계산을 위해서 상용 다용도 열유체 해석 코드인 STAR-CD를 이용하였다. 서로 다른 연소 모델의 차이를 비교하기 위하여 3단계 EBU 모델, 3단계 반응을 선택 모델, PPDF 모델을 이용하였다. 이중 3단계 반응 모델과 PPDF모델은 경향적으로 타당한 결과를 보였으며 이들간에 서로 다른 결과도 모여 주었다. Numerical analysis of the model gasturbine combustor is performed with various chemical reaction models and turbulence intensities and compared with experiment measurements of temperature, chemical species concentration and velocity. For calculation, commercial multi purpose CFD code STAR-CD is used. To study differences of solutions using different combustion models, 3-step eddy break up model, 3-step hybrid chemical reaction rate model and PPDF model are used. Among them 3-step model and PPDF model shows reasonably good agreements to experimental measurements. But each model gives slight differences.

임균의 R-plasmid에 의해 생산되는 Beta-Lactamase의 성상에 관한 연구

구자현 건국대학교 의과학연구소 1992 건국의과학학술지 Vol.2 No.-

The beta-lactamase purified from E. coli transformant having bla gene cloned from R-plasmid of Neisseria gonorrhoeas was partially characterized. The purified beta-lactamase gave a single protein band on SDS-polyacrylamide gel electrophoresis and isoelectric focusing, and also gave a single peak on HPLC-gel filtration, which gave a good indications that this enzyme was protein monomer. The characterization of this enzyme established a molecular weight of approximately 28,000 and an isoelectric point of 5.45. It can be suggested that the beta-lactamase produced in this transformant strain closely resembles the character of TEM-type 1 beta-lactamase.

반복성 혈뇨(IgA 신병증 및 non-IgA 신병증)와 알레르기성 자반증 신염의 면역지표의 변동에 관하여

현명철,고철우,구자훈 慶北大學校 醫科大學 1991 慶北醫大誌 Vol.32 No.1

A prospective study was conducted to see the changes of immune system in recurrent gross hematuria(IgA nephropathy and non-IgA nephropathy) and HSP nephritis in children. Study patients consisted of 60 children with recurrent gross hematuria and Henoch-Scho¨nlein purpura nephritis (8 IgA nephropathy, 24 non-IgA nephropathy and 28 HSP nephritis). The cellular immune indices(total T, T4, T8 cells and T4/T8 ratio) and humoral immune indices (IgG, A, M and E) were measured during the hematuric and non-hematuric period. Following results were obtained. The proportion of T4 cells of peripheral blood during the hematuric period of patients with IgA nephropathy rose to 35.4±14.9% from the non-hematuric value of 20.0±9.1%. The T4/T8 ratio during hematuric period of patients with IgA nephropathy rose to 1.51±0.77 from non-hematuric value of 0.73±0.33. The values of serum IgA and IgE during hematuric period of patients with IgA nephropathy rose to 237±106 ㎎/dl, 231±226 IU/dl from non-hematuric values of 140±10, 28±23, respectively. These changes of cellular and humoral immune indices showed statistically significant differences(p<0.05). However, these changes were not found in patients with non-IgA nephropathy nor HSP nephritis. In conclusion, it can be said that the immune mechanism involved in IgA nephropathy is different from that of HSP nephritis.

십이지장에서 발생한 간양 선암종 : 1예보고 a case report

구자홍,임현철,김진영 關東大學校醫科大學醫科學硏究所 1998 關東醫大學術誌 Vol.2 No.1

The hepatoid adenocarcinoma is a rare extrahepatic primary neoplasm showing similar histopathologic features of primary hepatocellular carcinnoma and usually produce a large amount of alpha-fetoprotein hepatic type. There ate several pathologic and radiologic reports of adenocarinoma of stomach, lung, pancreas, gallbladder, bile duct, ampulla of Vater, renal pelvis arid urinary bladder. Authors report a case of biopsy-proven hepatoid adrnocarcinoma of the duodenum.

초고진공용 주사형 터널링 현미경의 제작

김달현,박해원,이세경,구자용,김구영 韓國非破壞檢査學會 1994 한국비파괴검사학회지 Vol.14 No.3

진공도가 10-¹¹Torr 수준의 초고진공 상태에서 작동되고 실제공간에서 개별원자를 구별할 수 있는 주사형 터널링 현미경을 제작하였다. 주사형 터널링 현미경의 배경 및 작동원리와 제작에 있어서의 제문제점들을 서술하고 흑연결정과 실리콘에 대해서 관찰한 결과를 보고한다. A scanning tunneling microscope has been built, which can resolve atomic arrangements of conductors and semiconductors in ultra high vacuum below 10-¹¹Torr. Its background operational principles are reviewed and the guide lines in building the scanning tunneling microscope are shown. The results of measurements for highly oriented pyrolytic graphite and Si(111) surface are presented

기관내 삽관 후 발생한 기관 괴사와 협착증 : 증례보고 A case report

권진형,구자욱,유시현 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

Tracheal necrosis and stenosis are rare complications of prolonged endotracheal intubation. A 62 years old female was performed cerebral aneurysmal neck clipping under general anesthesia via endotracheal intubation and transferred to the 12th intensive care unit. The patient was mechanically ventilated and tracheostomy was done on the postoperative day. Necrotic tissue, pus and stenosis were found around the ballooning site of the trachea. T-tube insertion was done on the both postoperative day and the patient was discharged on the 80th postoperative day.

Pb(SCN)₂-KClO₃-Sb₂S₃-TNT 혼합물의 연소에 관한 연구

김우식,구자현,염경호 연세대학교 산업기술연구소 1985 논문집 Vol.17 No.2

The study on the combustion of the Pb(SCN)₂-KCIO₃-Sb₂S₃TNT mixtures are performed with the changes of several operational factors, and its results are as follows; In the drying method, as the increase of the inserting of binders, the impact sensitivity is decreased when the weight of the drop ball is higher, and F, S and ?? of the non-binding mixtures are satisfactory. In the wet method, the squib of mixtures are founded and F, S and ?? are less satisfactory than drying methods, but the impact sensitivity are more satisfactory than drying method. In the measurement of the explosion-delay time of mixtures, the mixtures in drying method are more uniform composition than that in wet method.

신생아 황달질환에서의 RDW의 진단적 의의

김행미,신채옥,현명철,이건수,이상범,구자훈 慶北大學校 醫科大學 1995 慶北醫大誌 Vol.36 No.3

목적 : 신생아 적혈구는 그 모양이 불규칙하여 여러 측정치가 성인 및 소아와 다르다, 저자들은 국내에서 보고된 바 없는 신생아의 Red cell distribution width(RDW)를 조사하여 신생아 정상 측정치를 제시하는 동시에 신생아 시기의 적혈구에 손상을 미치는 질환의 RDW를 분석하여 진단상 의의를 조사하였다. 대상 및 방법 : 신생아 집중치료실에 입원한 만삭아중 감염소견이 없었던 78명과 ABO부적합증 및 패혈증 환아에서 hemoglobin, hematocrit, MV, RDW 및 망상적혈구를 측정하였다. 결과 : 생후 1일부터 7일까지의 만삭신생아의 RDW 17.4±1.5로 소아 정상치 13.4±1.2%에 비해 증가되어 있었으나 출생후 7일까지 hemoglobin, hematocrit는 의의있게 감소한 반면 RDW는 변동이 없었다. 같은 연령의 ABO 부적합증 및 패혈증 환아군은 대조군에 비해 의의있게 hemoglobin과 hematocrit가 낮았으나 RDW는 대조군과 질병군 및 각 질병군 사이에 차이를 보이지 않았다. RDW와 망상적혈구는 ABP 부적합증에서만 상관계수 0.91 (p<0.001)의 상관관계를 보였다. 결론 : 출생후 7일까지 계측한 정상 신생아의 RDW는 소아에 비해 증가되어 있으나 출생후 변화는 없었다. ABO 부적합증 및 패혈증 환아군의 RDW는 대조군과 질병군 및 각 질병군 사이에 차이를 보이지 않아 이들 질환의 진단적 의의가 없었다. ABO 부적합증에서 RDW가 망상적혈구 수와 높은 상관관계를 나타내므로서 자동 분석기로 측정된 RDW로서 망상적혈구 수를 추정할 수 있었다. The RBC distribution width(RDW) has been reported to be of value in the early and differential diagnosis of several RBC disorders, with no sufficient studies on the newborn population. Seventy-eight normal fullterm newborns were studied to establish normal values for RDW of 1st week of life. The RDW of 43 patients with ABO incompatibility or sepsis was then evaluated for the usefulness of the RDW in diagnosis of Jaundice. The RDW was 17.7 ± 1.2 and 17.5 ± 0.8 at 1st and 4-7th days of life, revealing no differences de pending on the postnatal age. The RDW of newborns with ABO incompatibility, sepsis with and without jaundice were 18.4 ± 2.2, 18.2 ± 1.1 and 17.3 ± 0.9 respectively. The RDW was found to be consistently elevated in all these newborn infants-the normal newborns and the newborns with ABO incompatibility or sepsis-when compared with normal older children at our hospital. That reveals a physiologic state of anisocytosis in the newborn, showing no significant differences between these infants. Our results suggest that RDW alone cannot be used as an indicator to distingish between jaundice induced by hemolysis and by other causes. In this study all parameters examined except the reticulocyte counts of ABO incompatibility, which showed, by regression analysis, no correlation with the RDW. High RDW in ABO incompatibility is consistent with high reticulocyte count. One clinical value of the RDW therefore may lie in its capacity for reflecting active erythropioesis in ABO incompatibility. Thus the study has confirmed that red blood cell anisocytosis, as determined by RDW, has no value to differentiate the etiology of jaundice in the newborn period but it seems that RDW plays a role in determining the reticulocyte count in newborns with ABO incompatibility.

혈관성 파킨슨증의 경사에코 자기공명촬영 소견 : 환자-대조군 연구 A Case-Control Study

배희준,김병건,구자성,김현숙 대한치매학회 2002 Dementia and Neurocognitive Disorders Vol.1 No.2

Background & objective : Changes of signal intensity in the various Structures of basal ganglia(BG), Which can be detected by gradient echo MRI(GE-MRI). have been reported in different kinds of parkinsonism Altered iron content in these structures may be a possible explanation of above phenomenon Vascular parkinsonism is a kind of parkinsonism syndrome and is common However. There have been no reports about the BG signal changes on GE-MRI in vascular parkinsonism Methods : We investigated the difference of signal intensity in various BG and midbrain structures between 36 patients with vascular parkinsonism. which was defined as clinical parkinsonism+evidence of relevant vascular lesion on MRI+poor or no response to levodopa, and age-& sex- matched controls. The intensity of BG on GE-MRI was graded as 0-3 relative to cortical gray matter Results : There were no significant differences in clinical characteristics between two groups Among patients with vascular parkinsonism, hypointensity was observed in globus pallidus in 94.4%. in putamen in 58.3% in head of caudate in 33.3%, in substantia nigra in 72.2%,& in red nucleus in 52.8% There was no significant linear trend in the association between signal intensity of above structures and the presence of vascular parkinsonism (p>0 05 on Mantel-Haenszel chi-square test) However, the correlation between the degree of white matter lesions and the presence of vascular parkinsonism was statistically significant (p=003). Conclusions : Our GE-MRI study fails to prove that iron content of various BG structures in patients with vascular parkinsonism is different from controls.

한국인 편두통 환자와 미토콘드리아 DNA 11,084 유전자 다형성의 연관성

김병건,배희준,구자성,권오현,김만호 대한두통연구회 2002 두통 Vol.3 No.2