Combustion characteristics of gaseous inverse O₂/H₂ coaxial jet flames in a single-element model combustor

Kim, Tae Young,Choi, Sun,Kim, Young Hoo,Ahn, Yeong Jong,Kim, Hee Kyung,Kwon, Oh Chae Elsevier 2018 ENERGY Vol.155 No.-

<P><B>Abstract</B></P> <P>To effectively design hydrogen (H<SUB>2</SUB>)/oxygen (O<SUB>2</SUB>) liquid rocket engines through understanding the combustion characteristics of H<SUB>2</SUB>/O<SUB>2</SUB> bipropellants, fundamental studies for the bipropellants in different phases are needed. This study is focused on the combustion characteristics of inverse gaseous O<SUB>2</SUB>/H<SUB>2</SUB> coaxial jet flames in a single-element model combustor as a preliminary step for succeeding studies of injection at different phases in the combustor, visualizing flame structure by direct imaging, OH<SUP>∗</SUP> chemiluminescence and OH planar laser-induced fluorescence. With increasing Reynolds number (Re), the frequency of occurrence of the local flame extinction increases and the length of the disconnected OH reaction zone is extended. The OH layer thickness increases downstream, while it is almost constant where the local flame extinction occurs and decreases with increasing Re due to the enhanced strain and scalar-dissipation rates. The excessive flame wrinkledness increases the local flame strain rate and results in the local flame extinction, exhibiting the tendency of increasing and then decreasing flame surface density with increasing Re. The probability density function of OH intensity quantifies the fluctuation intensity of OH radicals and the possibility of the local flame extinction. A useful database is provided for modeling the combustion of H<SUB>2</SUB>/O<SUB>2</SUB> bipropellants under different phases.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A useful database for modeling the H<SUB>2</SUB>/O<SUB>2</SUB> bipropellant combustion is provided. </LI> <LI> Local flame extinction frequently occurs at high Reynolds number (<I>Re</I>). </LI> <LI> OH probability density function indicates the possibility of local extinction. </LI> <LI> Flame surface density increases and then decreases with increasing <I>Re</I>. </LI> <LI> Strong burning of O<SUB>2</SUB>/H<SUB>2</SUB> causes laminar-like combustion near the injector lip. </LI> </UL> </P>

신이식에서 이식신의 생존분석

오선미,김종학,황평주,구영선,강민규,나기량,김종섭,김성숙,이강욱,신영태,설종구,배진선,손기섭 충남대학교 의과대학 지역사회의학연구소 1997 충남의대잡지 Vol.24 No.2

To investigate the prognostic factors for the survival of transplanted kidney in patients with end-stage renal failure, 59 cases of renal transplantation from September 1986 to Feburary 1997 in Chungnam National University Hospital were analyzed retrospectively. The results were as follows: 1)The mean age of recipients was 33.8 years and that of doners was 38.9 years. The male to female ratio of recipients was 2.5:1, and that of donors was 1.03:1 2) Living related donore(LRD) were 79.6% and living non-related donors were 20.3%. The HLA-identical donors(ID) in LRD were 18.7% and HLA-haploidentical donors(HID) were 61.0%. In living non-related donors(LNRD), mean matched HLA-AB antigens were 1.56 and mean matched HLA-DR antigens were 0.56. 3) The average 5-year patient survival fate was 94%, and average 5-year graft survival rate was 70%. The 5-year graft survival fate of HLA-ID was 100%, and those HLA-HID and LNR were 70% and 36% respectively. 4) Total 33 episodes of acute rejection were found in 45.8% of transplanted patients. The number of acute rejection episode did not show significant difference between LRD and LNRD(P > 0.05). There was no significant difference in MLC between two groups(p > 0.05). 5) In comparison between the 18 patients who lost their graft function in 5 years and 17 patients who are maintaining graft function for more than 5 years, MLC was significantly lower in patients with functioning graft than of patients with non-functioning graft (p < 0.05). The number of rejection episode was also lower in patients with functioning graft than that of the patients with non-functioning graft(p < 0.05). However, there were no significant difference in recepient and donor age and history of pre-transplantation donor specific transfusion between two groups. With the results above, we can speculate that adequate donor selection according to good matched HLA typing and low MLC is very important for graft survival in renal transplantation. Prevention and treatment of acute rejection in renal transplantation is also na important factor for graft survival.

위절제술 환자의 표준진료지침 개발 및 적용 효과

김은희,김철규,이순교,김순덕,이혜옥,권정순,이경미,이민미,심순미,유용만,신종식,강은희,이상일,김병식,오성태,육정환,박수길 한국의료QA학회 2003 한국의료질향상학회지 Vol.10 No.2

Background : Gastric cancer is the most common malignant tumor in Korea. surgical operation is one of the major treatment modalities for gastric cancer patients. Therefore, gastrectomy is one of the most common procedures in General Surgery. There were variation in length of hospital stay and medical treatment for gastrectomy between three surgeons at Asan Medical Center. Clinical pathways have received considerable attention as a tool for recucing the medical practice variation, increasing the efficiency of care process, and improving the quality of care. The aim of this study was to evaluate the effect of a clinical pathway for gastrectomy in gastric cancer patients. Methods : The clinical pathway for gastrectomy was developed and implemented by a multidisciplinary group in Asan Medical Center. A computerized clinical pathway program was developed and revised after a pilot test. A total of 145 patients underwent gastrectomy by three surgeons at Asan Medical Center. We compared the length of hospital stay, patient satisfaction, and unplanned readmission rate between the pre-pathway group(n=67) and the post-pathway group(n=78). We also investigated the degree of satisfaction among the physicians and nurses who were main end-users of the clinical pathway. Results : The clinical pathway was applied to all target patients. The average length of hospital stay was shortened from 12.7days to 10.6days(p<0.01). The degree of patient satisfaction with the care process changed from 90.3% to 89.2% after the implementation of the clinical pathway, but the difference was of satistically significant(p=0.761). Unplanned readmission rate was 2.9% in the pre-pathway group. More than 90% of physicians and nurses answered that the clinical pathway had been a useful tool in their medical practice. Conclusions : The findings of the study demonstrated that implementation of the clinical pathway for gastrectomy produced substantial reduction in the length of hospital stay while improving the quality of patient outcomes. The computerized clinical pathway program can be used as one of the powerful patient management tools for reducing the practice variations and increasing the efficiency of care process in Korea hospital settings.

Rifampicin에 의한 것으로 추정되는 위막성 대장염1예

김수현,이은우,정종혁,문승현,김동한,양혁승,오영상,김호동,김도현,박혁,박정환,박경옥,이영직 朝鮮大學校 附設 醫學硏究所 2006 The Medical Journal of Chosun University Vol.31 No.2

Pseudomembranous colitis, caused by altering the normal colonic flora and allowing the multiplication of Clostridium difficile, is an deleterious adverse effect of antibiotics. But it is rarely reported by rifampicin. Rifampicin is one of the first line drug in the treatment of tuberculosis and many patients are exposed to its potential adverse effects. We experienced a patient that had abdominal discomfort and hematochezia due to pseudomembranous colitis after receiving antituberculous medication, and which was probably caused by rifampicin. A 82 years old man was admitted with abdominal discomfort and hematochezia for one week. On the past history he had been diagnosed as endobronchial tuberculosis about 4 months ago. Colonoscopy revealed multiple discrete whitish mucosal lesion on rectosigmoid colon, and histologic findings were consistent with pseudomembranous colitis. The antituberculous agents were discontinued and vancomycin was administered. The patient's symptoms were resolved within several days. There was no recurrence after reinstitution of the antituberculous agents excluding rifampicin. We report here on a case of pseudomembranous colitis probably due to rifampicin.

기종성 방광염을 동반한 기종성 신우신염 1예

김선두,김순제,이길도,김정수,김지훈,윤호상,송종오,문언수 대한노인병학회 2000 Annals of geriatric medicine and research Vol.4 No.3

수출입 컨테이너 장치장 배정을 위한 소프트웨어의 개발

김갑환,김홍배,홍봉희,김기영,배종욱,최진오,김두열,이영기,박영만,박강태,손행대 한국경영과학회 1995 經營 科學 Vol.12 No.3

The Pusan Container Terminal faces a rapid increase in berthing time of container ships as well as in waiting time of external trucks, which is due to an absolute lack of yard space. This research is focused on the development of a decision support system for the planning of the container terminal yard assignment so that the yard space would be utilized most effectively. Efforts should be given to the reasonable assignment of the yard storage and the dynamic adaptation to the ever changing environment. The software introduced here is based o the know-how of the field exports and its framework takes the approach of the hierarchical decision making.

Effect of synthesis parameters on visible light photocatalytic activity of graphene-TiO₂ nanocomposites for industrial wastewater treatment

Kim, Seu-Run,Ali, Imran,Kim, Jong-Oh THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2018 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.66 No.-

<P><B>Abstract</B></P> <P>Reduced graphene oxide (RGO)-TiO<SUB>2</SUB> nanotubes (TNTs) were used for industrial wastewater treatment that was obtained from Banwol Sihwa Industrial Complex, Korea. RGO-TNT were fabricated using one-step and two-step anodization at different RGO concentrations, RGO deposition times, anodization voltages and anodization times. Synthesized catalysts were characterised using FESEM, XRD, TEM, EDS, XPS, UV–vis DRS, PL, Raman, and pH<SUB>PZC</SUB>. Compared with pure-TNTs, two-step and one-step RGO-TNT exhibited 2.7 and 3.3-times higher photocatalytic activities for industrial wastewater. Scavenger experiments identified that OH and e<SUP>−</SUP> are main species involved in photocatalytic degradation of MB and industrial wastewater. RGO-TNTs are suitable for industrial wastewater treatment.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The photocatalytic degradation of industrial wastewater was performed using RGO-TNT. </LI> <LI> RGO-TNT were synthesized by one-step and two-step anodization method. </LI> <LI> We checked effect of RGO concentration & deposition time, anodization volt & time. </LI> <LI> One-step RGO-TNT synthesis was more efficient and stable than two-step synthesis. </LI> <LI> Scavenger test identified that OH* & e<SUP>−</SUP> are main species for photocatalytic process. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

운동 강도의 차이가 흰쥐의 혈액 성분과 적혈구의 형태에 미치는 영향

김부환,김종오,지용석,최대원,윤진환,정일규,김영욱,오봉석 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.4

This study was to investigate the effects on hematological indices and heinz body formation in various intensity, Male Sprague-Dawley rats were randomly divided into the control group, the low-intensity exercise group, nigh-intensity exercise group (n=7 in each group). Animals of the low-intensity exercise groups were put on exercise 30 min per 1 day, 5 days per week for 6-weeks. Animals of the high-intensity exercise groups were put on exercise 120 min per 1 day, 5 days per week for 6-weeks. Red blood cell count (RBC), hemoglobin (Hgb), hematocrit (Hct), mean ceil volume (MCV), mean hemoglobin corpuscular (MCH), mean hemoglobin corpuscular concentration (MCHC) were analyzed in automated hematology analyzer (ABX Hematology MICROS 60) from 10㎕ of whole blood. Erythrocyte morphology were evaluated in super vital (Brilliant cresyl blue stain) stained blood films. In the present results, Hg, MCHC in the high-intensity exercise group was significantly decreased compared with the different exercise intensity and the control group. MCV in the high-intensity exercise group was significantly increased compared with the different exercise intensity end the control group. Heinz body formation in the high-intensity exercise group was significantly increased compared with the different exercise intensity and the control group. In the present study, it can be suggested that intensity of exercise can influence hematological variables and heinz body formation. These findings suggest that high intensity exercise induces oxidative damage to erythrocyte.

아미노글리코사이드 사용제한에 따른 병원성 균혈증 유발 그람음성간균의 내성변화 및 임상적 의의

오종택,김신우,손종원,도병훈,한승우,신병철,박지현,이종명,김능수 대한감염학회 2003 감염과 화학요법 Vol.35 No.4

목적 : 항균제 오남용으로 인한 내성균의 출현, 약물부작용의 발생 및 약제 비용의 증가는 환자 개인뿐만 아니라 사회적으로 문제가 되고 있다. 본 연구는 항생제의 오남용을 막기 위한 제도의 일환으로 시행한 아미노글리코사이드 사용 제한정책의 비용 효과적인 측면을 조사하고 그람음성간균에 의해 병원성 균혈증이 발생한 환자들을 대상으로 이 정책이 항생제 내성률과 환자 사망률에 미치는 영향을 연구하였다. 방법 : 930병상 규모의 3차 병원인 일개 대학병원에서 아미노글리코사이드 사용제한정책이 시행된 직후인 2002년 3월에서 9월 사이에 그람음성간균(Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae, Enterobacter aerogenes, Serratia marcescens, Stenotrophomonas maltophilia, Burkholderia cepacia)에 의해 발생한 병원성 균혈증 환자 60명(실험군)과, 이 정책이 시행되기 전에 입원한 환자들 중 균주별로 같은 수만큼 선별한 병원성 균혈증 환자 60명(대조군)의 의무기록을 후향적으로 조사하였다. 결과 : 아미노글리코사이드 사용제한정책이 시행된 시기인 2002년 3월에서 9월 사이에 처방된 아미노글리코사이드 사용량 및 비용을 이 정책이 시행되기 전인 2001년 3월에서 9월 사이와 비교한 결과, 아미노글리코사이드의 사용량(antimicrobial utilization density)은 사용제한 후 225.2에서 130.3으로 42% 감소하였고 약제 비용은 44% 감소하였다. 아미노글리코사이드 사용제한 후 병원성 균혈증을 유발한 그람 음성간균의 이 항생제에 대한 내성률은 유의한 변화를 보이지 않았으며 균혈증과 직접 연관된 사망률도 환자의 나이, 성별, 기저질환 및 원발병소 등을 보정할 경우 유의한 차이를 보이지 않았다(40.4% vs. 24.1%, P=0.11). 결론 : 아미노글리코사이드를 5일을 초과한 사용 시 감염전문가의 사전 승인을 필요로 하는 사용제한정책은 아미노글리코사이드의 사용량과 비용을 유의하게 감소시켰다. 또한 이 정책 시행 후 그람음성간균에 의한 균혈증 환자에서 균혈증으로 인한 사망률과 아미노글리코사이드에 대한 내성률은 유의한 차이가 없었다. Objective : To evaluate the effects of an aminoglycoside restriction policy on expenditures for aminoglycosides, antimicrobial resistance rates and clinical outcome of nosocomial bacteremia caused by Gram-negative bacilli (GNB). Methods : Starting in February, 2002, a prior consultation with an infectious disease specialist for using aminoglycoside antibiotics over 5 days was required in a 930-bed university hospital. In retrospective analysis of medical records 7 months after initiation of the aminoglycoside restriction policy, sixty cases of clinically relevant nosocomial bacteremia caused by GNB were found. These bacteremic patients were compared with sixty, species-matched, control patients with nosocomial Gramnegative bacteremia before the policy for total expenditures for aminoglycosides, susceptibility to antibiotics and clinical outcomes of bacteremia. Results : During the same period of 7 months before and after the restriction policy, total expenditures for aminoglycosides decreased by 44% in cost (from 465,030,841 Won to 259,618,337 Won) and the antimicrobial utilization density of aminoglycosides decreased by 42% (from 225,2 to 130.3). On the other hand, the patterns of antibiotic susceptibility and bacteremia-related in-hospital mortality rates after the policy did not show a significant change, compared with those before the policy. Conclusion : Antibiotic restrictions are among the most popular methods to diminish the practice of antibiotic overuse in hospitals. In this study, requirement for prior approval of aminoglycoside use over 5 days led to a significant decrease in the amount and cost of total aminoglycosides without a significant change in susceptibility patterns and bacteremia-related mortality rates.

원문 : 저항성 운동이 노화 흰쥐 해마 및 소뇌의 신경가소성 인자 발현 및 미세구조와 신경학적 기능에 미치는 영향

김종오 ( Jong Oh Kim ),윤진환 ( Jin Hwan Yoon ) 한국운동생리학회(구 한국운동과학회) 2014 운동과학 Vol.23 No.3

김종오, 윤진환. 저항성 운동이 노화 흰쥐 해마 및 소뇌의 신경가소성 인자 발현 및 미세구조와 신경학적 기능에 미치는 영향. 운동과학, 제23권 제3호, 217-228, 2014. 본 연구는 노화로 인해 나타나는 기억력 감소와 균형감각의 저하를 저항성 운동이 지연시킬 수 있는지와 그 기전을 밝힘으로써, 노인운동처방학적 운동기전을 제시하고자 하는데 있다. 이러한 목적을 달성하기 위해 노화 흰쥐를 대상으로 tower climbing 운동을 12주간 실시한 후 신경기능학적 향상, 신경가소성 인자인 BDNF, TrkB의 발현 증가와 시냅스 관련 단백질인 synapsin I의 발현을 유도할 수 있는 지와 해마의 연접형성수준의 증가에 어떠한 영향을 미치는 지를 확인하고자 하였다. 본 연구에 이용된 실험동물은 Sprague-Dawley 계열의 노화 흰쥐 72주령 수컷과 대조군으로 10주령 수컷이 이용되었으며, 이들은 실험 전 일주일 동안 운동 환경에 대한 적응기간을 거친 후, 무작위 표본추출에 의하여 노화 쥐는 노화 대조군(aging control group, ACG; n=15)과 노화 운동군(aging and exercise-trained group, AEG; n=15)으로 분류되었고, 10주령의 정상 대조군(normal control group, NCG; n=15)이 비교군으로 이용되었다. 저항성 운동은 tower climbing protocol을 이용하여 1일 약 30분씩 3회(09시, 14시, 20시) 12주 동안 훈련시켰다. 공간학습과 기억력과 균형감각과 신경학적 기능평가는 Morris water maze와 balance beam 검사가 이용되었고, BDNF, TrkB와 synapsin I과 같은 단백질 분석은 Western blotting 방법이 이용되었다. 또한, 해마부위 연접형성수준의 변화는 투과전자현미경(TEM)적 관찰을 통해 확인하였다. 그 결과 본 연구에 수행된 저항성 운동인 tower climbing 운동의 12주간 훈련은 노화로 인해 해마, 소뇌 부위의 신경 및 연접가소성인자 감소로 인해 저하된 공간학습기억능력과 평형감각기능을 지연시키는데 효과적인 운동임을 확인할 수 있었던 연구이다. Kim, Jong-Oh, Yoon, Jin-Hwan. Effects of Resistance Exercise on Synaptic Plasticity Factor, Ultrastructural and Neurologic-Function in Hippocampus and Cerebellum of Aging Rats. Exercise Science, 23(3): 217-228, 2014. Aging results in cognitive and balance decline both in humans and animals. Neurogenesis in the hippocampus and cerebellum also declines with age. Traditionally, exercise has been used for the treatment of several neuro degenerative disorders. Thus, the purpose of this study was to investigate the effects of resistance exercise on spatial learning memory ability, the synapses and the synaptic-plasticity neurotrophic factor in hippocampus and cerebellum in aged-rats. The experimental animals were divided into three groups (n=15 in each group): the normal control group (NCG), the aging control group (ACG), the aging and exercise-trained group (AEG). Animals in the exercise group were performed to daily exercise on the tower climbing during 12 weeks. The spatial learning and memory capability was evaluated by Morris water maze in a separate set of rats. Also, the balance function was evaluated by Balance beam test. Western blotting analysis for the expression of BDNF, TrkB and synapsin I was performed. Electron microscopy were used to evaluate synaptic plasticity and quantitative electron microscopy was used to investigate morphological changes in the hippocampus. Measurements taken from analysis of the electron micrograph sets were used to calculate the spine synapses in hippocampus. Here in this study, it have shown that both synaptic plasticity neurotrophic factor expression and spine synapses were suppressed in aged-rat, whereas tower climbing exercise alleviated the aging-induced suppression of both synaptic-plasticity neurotrophic factor expression and spine synapses in the hippocampus of rats. The results of the present study indicate that tower climbing exercise may facilitate recovery from the CNS complications associated with aging by inducing enhanced the morphological development of synapses in the hippocampus via the augmentation of synaptic plasticity neurotrophic factor expression in the h ippocampus a nd t he cerebel l um.