直接噴射式 디젤엔진에서 GTL熱料의 EGR率變化에 따른 排出物 特性에 關한 硏究

金秉儁,崔源鶴,柳鍾植,李海喆,車京玉 명지대학교 산업기술연구소 2008 産業技術硏究所論文集 Vol.27 No.-

Recently, altenative fuels are drawing more attentions due to the increasing need for lower emission characteristics and fuel consumption rate in automotive engines. The GTL(gas to luquid) is the one of most favored candidates. It has higher cetane number(more than 75) and almost negligible sulphur and aromatic contents. Therefore, enhanced emission characteristics are expected even in the application in diesel engines without any modification. In this study, the cylinder pressure and heat release, emission characteristics with fuel injection timings are compared between diesel and GTL fuel in the single cylinder diesel engine. Noticeable reduction in PM, THC and CO emission are observed due to lower sulphur and aromatic contents in GTL. Also, the ignition delay decreased due to higher cetane number of GTL , which slightly decreased the amount of NOx emissions. EGR is considered as a most efficient method to reduce the NOx emission. With EGR rates, NOx decreases more for the case of GTL, while the level of THC and CO emissions still remains lower than the case of diesel. With EGR rates, Small size distribution of PM became lager and there amount increased. Bul from all conditions, size distribution of PM for the case GTL was lower than Diesel.

Mycophenolic Acid와 Rapamycin이 흰쥐 사구체 혈관간세포증식과 세포외기질 생성에 미치는 영향

김명수,박제현,하헌주,허규하,서지연,김유선,김혜진,박기일 이화여자대학교 약학연구소 2004 藥學硏究論文集 Vol.- No.14

Background: Excess proliferation and extracellular matrix (ECM) accumulation of mesenchymal cells such as vascular smooth muscle cells (VSMC) and glomerular mesangial cells cause chronic allograft nephropathy showing transplant vascular sclerosis and glomerulosclerosis. Mycophenolic acid (MPA) and rapamycin (RPM) are well known as strong inhibitors of VSMC proliferation, but their effects on the glomerular mesangial cells are not yet clearly understood. This study examined the effects of MPA or RPM on PDGF-induced proliferation and ECM accumulation in rat glomerular mesangial cells. Methods: Mesangial cells isolated from the glomeruli of Sprague-Dawley rats were cultured with DMEM containing 20% fetal bovine serum. Growth arrested and synchronized cells were administered with test drugs (MPA10 nM-10μM, RPM 0.1 nM-1μM) before the addition of PDGF 10 ng/mL. Cell proliferation was assessed by [³H]thymidine incorporation, collagen by [³H]proline incorporation, and fibronectin, ERK, and p38 MAPK by Western blot analysis. Results: PDGF increased mesangial cell proliferation by 4.64-fold. Compared to stimulated control, MPA above 500 nM and RPM above 10nM showed a significant inhibitory effect in a dose-dependent manner. The IC_(50) of MPA and RPM against PDGF-induced mesangial cell proliferation were around 500 nM and 100 nM, respectively. The collagen synthesis was also inhibited by MPA and RPM, but the fibronectin secretion was inhibited by MPA alone. The proliferation of mesangial cell correlated with activation of ERK and. p38 MAPK. MPA, but not RPM, inhibited ERK and p38 MAPK activation. Conclusion: This study demonstrated that MPA and RPM significantly inhibited PDGF-induced proliferation and ECM production in rat glomerular mesangial cells. The inhibitory effects of MPA, but not RPM, are correlated with ERK and p38 MAPK.

수정 몬테칼로법에 의한 鐵筋콘크리트 보의 離散形 最適設計

김유식,이해은,박경현 大田産業大學校 1999 한밭대학교 논문집 Vol.16 No.1

In this study, our effort has been made to review the economics design for the discrete optimum design of the R. C. beam section by modified Monte carlo method. In this discrete optimum formulation, the design variables are the overall depth, width and effective depth of beams and area of longitudinal reinforcement. Total weight has been used as the objective function. The constraints include the code requirements such as flexural strength and steel ratio. The proposed algorithm is applied to a test problem for reliability, and the results are compared with the Monte carlo optimum design and the modified Monte carlo optimum design by strength design method As a result of calculation, In the optimum convergence by the each method, it was very earlist on the case of 5cm unit. Optimum weight was very light in the case of 2cm unit. In the study, Our know to possible of design by the optimum design based on modified Monte carlo method.

코먼레일 單汽筒 디젤엔진에서 GTL 熱料의 噴射時期 變化에 따른 排出物 特性에 關한 硏究

金秉儁,崔源鶴,柳鍾植,李海喆,車京玉 명지대학교 산업기술연구소 2008 産業技術硏究所論文集 Vol.27 No.-

Recently, alternative fuels are drawing more attentions due to the increasing need for lower emission characteristics and fuel consumption rate in automotive engines. The GTL(gas to luquid) is the one of most favored candidates. It has higher cetane number(more than 75) and almost negligible sulphur and aromatic contents. Therefore, enhanced emission characteristics are expected even in the application in diesel engines without any modification. In this study, the cylinder pressure and heat release, emission characteristics with fuel injection timings are compared between diesel and GTL fuel in the single cylinder diesel engine. Noticeable reduction in PM, THC and CO emission are observed due to lower sulphur and aromatic contents in GTL. Also, the ignition delay decreased due to higher cetane number of GTL , which slightly decreased the amount of NOx emissions. With the retards of main injection timing. NOx decreases more for the case of GTL, while the level of THC and CO emissions still remains lower than the case of diesel. Therefore, there is much room for the control of injection timiing for NOx reduction without sacrificing THC and CO emissions. With the retards of main injection timing, Small size distribution of PM became lager and there amount increased. But from all conditions, size distribution of PM for the case GTL was lower than Diesel.

파라미터 적응을 이용하는 로보트 매니퓰레이터의 위치/힘 제어

유동영,김웅석,양해원 한양대학교 공학기술연구소 1992 공학기술논문집 Vol.1 No.1

Adaptive hybrid position/force controller for constrained manipulator with uncer dynamic model parameters and environment stiffness is presented. In this paper, the complia frame model is constructed by independent positions and forces to be controlled. The adap controller based on this compliance frame dynamic model is designed. Lyapunov theory is u for contoller design and stability analysis.

K-이온化를 위한 全斷面積과 阻止能 : Bethe 理論 The Bethe theory

庾基洙,金鎭城,朴海容 圓光大學校 基礎自然科學硏究所 1983 基礎科學硏究誌 Vol.2 No.1

In 1930 Bethe established a quantum mechanical theory based on the Born approximation, and derived a number of important results concerning the collision cross section and the stopping power for fast particles. However, there has been quite a difficulty in the following his original work(which was published in German), so that we rediscuss the subject in an effort to make the theory more accessible and fruitful for further studies on the motion of election in condensed matters.

Cisplatin 병용화학요법시 발생한 오심, 구토에 대한 Ondansetron과 Metoclopramide의 효과에 대한 비교

김미자,국기용,김태원,박유환,김완중,허경,정춘해,홍순표 朝鮮大學校 附設 醫學硏究所 1993 The Medical Journal of Chosun University Vol.18 No.1

Inspite of possible effects for emesis following chemotherapy including cisplatin, nausea and vomiting are the most unpleasant side effects of cancer chemotherapy. None of the currently available antiemetic agents is entirely effective preventing emesis. Ondansetron, a 5-HT(5-hydroxytryptamine)_(3) receptor antagonist, has been shown to be effective antiemetic agent in the control of cisplatin induced emesis. Twenty solid tumor patients who are scheduled to receive cisplatin containing combination chemotherapy participated in a prospectively randomized study to compare the antiemetic efficacy and safety of ondansetron and metoclopramide. Ondansetron was given in dose of 8mg intravenous 30min before cisplatin and then 4hours and 8hours after cisplatin on day 1, and Ⅰ.Ⅴ. every 8hours from day 2 to 5. In the metoclopramide group, metoclopramide was given in dose of 2 ㎎/㎏ intravenous every 8hours from day 1 to 5. The control of emesis was graded in the following way : complete response, no vomiting : major response, 1-2 emetic episodes : minor response, 3-5 emetic episodes : failure, above 5 emetic episodes. Complete or major response of emesis was achieved 10 of 12(83.2%) patients receiving ondansetron and in 5 of 8(62.5%) patients receiving metoclopramide, but effectiveness was not significantly different. Ondansetron was at least as effective as metoclopramide therapy in controlling cisplatin induced emesis. Side effects in ondansetron was less than in Metoclopramide.

전화번호안내원의 누적외상성 장애

정해관,최병순,김지용,유선희,임현술,김용민,어경윤,권용욱 大韓産業醫學會 1997 대한직업환경의학회지 Vol.9 No.1

To evaluate the prevalence of cumulative trauma disorders in relation to ergonomic evaluation of their work, 260 female directory assistance operators employed in three branch facilities of the nation-wide telecommunication company. Ergonomic evaluation of the work status was done by two industrial hygienists through inspection. Workers were surveyed with standardized self-administered questionnaire and examined by family physicians and an orthopaedician for cumulative trauma disorders. Laboratory examination of serum aspartate aminotransferase(AST), creatinine phosphokinase(CPK), aldolase and rheumatoid factor was done and X-ray of cervical spine and both shoulders was taken from all subjects and nerve conduction velocity test was done on 57 subjects with suspected nerve entrapment cases. Cumulative trauma disorders were categorized into 3 category according to work-relatedness of the disorders. On ergonomic evaluation of the working posture and work environment, improvement of work posture revealed inappropriate postures and devices. Mean age of the subjects were 39 years old and more than 80% graduated high school or above. Ninety-eight percent of the workers employed in the company for more than 15 years and 74.6% of the workers worked at the VDT job for more than 4 years. Mean daily work hours was 8.0 hours per day and mean break hours was 90.5 minutes per day with mean extra work hours of 10.7 hours per month. Mean daily calls were 1128.6 calls in maximum and 864-8 calls in minimum. On laboratory examination, 13.(5.0%) workers had abnormal AST, 53(20.4%) had abnormal CPK, and 1(0.4%) had abnormal aldolase level. On x-ray examination of cervical spine, 111(42.7%) had loss of or reversed normal cervical lordosis, 10(3.8%) had narrowing of intervertebral space. Nerve conduction velocity test was abnormal in 11(19.2%) among 57 workers. Among disorders categorized as work-related, 131(50.4%) were diagnosed to have fatigue myalgia of levator scapulae, 108(41.5%) had cervical strain or sprain, 47(18.1%) had fatigue arthralgia of phalangeal joints, and 47(18.1%) had probable carpal tunnel syndrome, in 10(3.8%) of those diagnosis was confirmed electrophysiologically. Age, seniority, work duration at present job, workload nor location of facilities were associated with the prevalence of symptoms nor specific diagnoses on simple statistical analysis and multiple logistic regression, which seems to be due to highly selected and homogeneous characteristics of the study subjects. Above results shows that cumulative trauma disorders are very prevalent among directory assistance operators and elaborate effort is needed to reduce the cumulative trauma disorders among the operators.

정신분열병의 인지적 표지자와 Catechol-O-Methyltransferase Val158Met 유전자 다형성의 연합연구

박해정,박동연,조은영,김나라,전현옥,이유상,이동수,홍경수 대한신경정신의학회 2008 신경정신의학 Vol.47 No.2

Objectives : Catechol-O-methyltransferase (COMT) gene has been identified as a positional and functional candidate gene of schizophrenia. Although specific mechanism of increasing schizophrenia susceptibility by this gene has not been well described yet, recent studies suggest that the valine allele of COMT Val158Met polymorphism may contribute to cognitive decline in schizophrenia. The present study investigated the association between this polymorphism of COMT gene and cognitive markers related to schizophrenia in both schizophrenia patients and normal controls. Methods : The subjects were 78 patients with schizophrenia diagnosed by DSM-IV and 97 normal controls. Comprehensive neurocognitive tests for which performance deficits have been reported in schizophrenia were administered. Genotyping for COMT Val158Met polymorphism was done with SNapShot method. Association analyses between genotype and cognitive functions were performed using ANCOVA and MANCOVA. Results : In the comparison of allele frequencies between patient and control groups, no significant association between the polymorphism and schizophrenia was observed. Significant differences of cognitive performance among genotype groups were not identified in control group. This trend was also observed in the patient group. In the combined analysis of both patient and control groups, there was no significant genotype or genotype-by group effect on any cognitive function measure. Conclusion : These findings do not support a major role of COMT gene in the regulation of the cognitive processes of schizophrenia.

제1대구치의 석회화와 맹출 양상

정해경,양연미,김재곤,백병주,소유려 大韓小兒齒科學會 2010 大韓小兒齒科學會誌 Vol.37 No.3

Among the permanent teeth, the first permanent molars play the greatest role in occlusion and function. So, early diagnosis for congenital missing, abnormal eruption and abnormal formation is very important to the first permanent molars in the course of arch development. The aim of this study is to analyse the differences between right and left first permanent molar's formation and eruption and between upper and lower one. A total of 545 children were selected am ong children who had visited our clinic, investigate eruption and calcification stage of permanent first molar, based on Gleiser and Hunt criteria for this study. 1. Gingival emergence of mandibular first molar is faster than maxillary first molar by 0.75~0.8 years, gingival emergence of maxillary first molar in girls faster than boys by 0.45 years, and that of mandibular first molar in girls faster than boys by 0.5 years. 2. There is the significant difference between right and left first molar on the eruption score and the calcification stage ; 5 year old children show the significant difference on the eruption score. 7 year old children show the significant difference on both the eruption score and calcification stage. 3. It shows the most active eruption movement of crown on the maxilla while the root is rapidly widening its furcation and completing root formation to 2/3, on the other hand, the most active crown emerging on mandible is shown when the root formation completed to 1/4 to 1/2. 제1대구치는 치열의 교합 및 발육에 중요하게 관여하며 기능적, 형태적으로 건전한 교합의 발육 및 유지에 필수적인 치아이다. 치열의 발육과정에 있어서 제1대구치의 형성, 맹출 및 형태의 이상이나 선천결손의 발생여부를 조기에 진단하는 것은 매우 중요하다. 이 연구의 목적은 제1대구치의 맹출과 석회화 양상에 대해 조사하여 형성과 맹출의 상, 하악과 좌, 우 차이에 대해 평가하는 것이다. 2007년 7월부터 2008년 6월까지 전북대학교 치과병원 소아치과에 내원하여 파노라마 방사선사진을 촬영한 545명의 어린이를 대상으로, 제1대구치의 맹출 위치와, Gleiser and Hunt의 석회화단계의 분류를 이용하여 제1대구치의 석회화에 대해 연구한 결과 다음과 같은 결론을 얻었다. 1. 제1대구치의 구강내 출은은 하악 제1대구치의 구강내 출은이 상악 제1대구치의 출은보다 0.75~0.8년 빠르게 일어났으며, 여성은 남성에 비해 상악은 약 0.45년, 하악은 약 0.5년 먼저 출은했다. 2. 제1대구치의 석회화단계와 맹출 정도의 좌, 우 차이는, 5세에서 상악 좌, 우측 맹출 정도와, 7세에서 상악 좌, 우측 맹출정도, 하악 좌, 우측 석회화단계가 유의한 차이를 보였다. 3. 상악은 치근 분지부의 급속한 확대단계와 치근 2/3완성단계 사이에서, 하악은 치근 1/4완성단계와 치근 1/2완성단계 사이에 가장 많은 맹출 이동량을 보였다.