VOCs의 시료채취 및 보관에 따른 안정성 검토

봉춘근,김동술,김영두,김광래 경희대학교 환경연구소 2002 環境硏究 論文集 Vol.11 No.-

This study was fulfilled to evaluate the durability of VOCs for different sampling methods. The sampling methods widely used to collect atmospheric VOCs are Canister method (EPA method TO-141, Absorbtion tube method (EPA method TO-17), and Tedlar-bag method, and those methods are used in this study. The samples were analyzed after 0, 1, 3, 7, 15, 30 days to figure out the durability of components while keeping under low temperature (4℃) and room temperature (about 20 ℃). Each sample collected by above sampling method was analyzed by high resolution gas chromatography (GC) with flame ionization detector (FID). The test results were shown that the compounds in canisters and absorbtion tubs were stable, but the ones in tedlar-bags were not stable. Heavy components such as Toluene, m/p-Xylene in absorbtion tubes were kept their stability for a long time longer than the ones in canisters. However, the reducing rates of heavy components in canisters were not bigger than those of Tedlar-bags. The VOCs sample collected and stored in tedlar-bag are unstable for analysis, even after a days. As a result of this study, it is found that Canister method and Absorbtion tube method are reliable for collection and storage for a variety of ozone precursors compared to Tedlar-bag method. It is strongly recommended that the samples collected using Tedlar-bag need to be analysed shortly after sampling.

허혈성 심질환에 있어서 아데노신 급속 정맥투여후 관동맥압의 변화에 관한 연구

봉종대,오종용,배성한,신원용,김철현,이광희,최태명,현민수,김성구,권영주 순천향의학연구소 1998 Journal of Soonchunhyang Medical Science Vol.4 No.2

Background: Adenosine interacts with A1 receptors present on the extracellular surface of cardiac cells, activating K+channels in a fashion. It produces coronary vasodilatation and AV nodal block. The half-time is one to six second and has ultra-short action. In ischemic heart disease, fractional flow reserve(FFR) can be achieved safely with intravenous adenosine infusions at a rate of 150㎍/kg/min which cause maximal coronary hyperemia. Purpose: We investigated the patients who have had ischemic heart disease(n=8). After adenosine intravenous administration(150㎍/kg/min), the effect cause maximal hyperemia of coronary artery. During peak maximal hyperemia, we reported clinical findings, coronary hemodynamics and electrocardiogram findings. Methods: After diagnostic coronary angiography and left ventriculography, catheter was advanced into the ostium of coronary artery. We investigated coronary hemodynamics such as systolic coronary artery pressure, diastolic coronary artery pressure, mean coronary artery pressure and heart rate. To assess the use of adenosine for determination of fractional flow reserve, hemodynamics and electrocardiogram were measured at basal state and during peak maximal hyperemia. Results: Symptoms developed 1.5-2 minute after adenosine intravenous administration and each symptom disappeared 2-2.5 minute after adenosine administration. Two patients represented asymptomatic appearance and six patients complained of flushing, chest pain, palpitation and headache. In eight patients with ischemic heart disease, 1.5 minute after venous administration of 150㎍/kg/min of adenosine, coronary artery pressure decreased and heart rate increased significantly. Conduction abnormalities after administration of 150㎍/kg/min of adenosine were transient 2nd degree AV block 2 cases(25%). Conclusions: Adenosine is a potent ultra short-acting vasodilator. Although coronary artery pressure decreased and heart rate increased and mild cardiovascular symptoms occurred after continuous infusion of 150㎍/kg/min of adenosine, it is useful as an agent for determination of fractional flow reserve.

미주신경과 연결된 중추신경로내 Catecholamine성 신경세포에 관한 연구

황광민,이봉희,김은아,김명옥,이봉희,김은아,김명옥,백상호,이부영 대한해부학회 1998 Anatomy & Cell Biology Vol.31 No.1

자동차용 냉각수펌프의 성능 및 캐비테이션 특성 분석

최광호,김경훈,김봉환 慶熙大學校 레이저 工學硏究所 1996 레이저공학 Vol.7 No.-

In automobile cooling system, it is not easy to get the optimal design of the water pump due to limitation of installing location and types of operation of the water pump. The quality and durable water pump have been the resent focus of considerable interest by water pump companies and automobile manufactures. In this study, experiments are performed to get performance and efficency of the water pump at different condition as temperature, rotating speeds, types of coolant. The characteristics of water pump are effected by cavitation. And then, cavitation effects of water pump are investigated for developing the future automoble cooling system.

영동지역 주요 3개 하천의 수질실태 및 관리에 관한 연구

박광하,민선홍,최봉종,전방욱 강릉대학교동해안지역연구소 1994 東海岸硏究 Vol.5 No.1

영동지방의 주요 3개 하천의 수질을 조사하고 QUAL-2E 모델을 적용하여 보았다. 강릉남대천은 각 수질항목에서 시기별, 정점별로 큰 차이를 보였으며, 일반적으로 상류의 수질은 하류로 갈수록 생활오수의 유입으로 수질이 악화되는 전형적인 양상을 나타내었다. 양양남대천은 강릉남대천 및 삼척오십천에 비하여 시기별 변이폭이 좁았으며 각 정점별의 수질도 양호한 것으로 나타났다. 삼척오십천은 시기별보다는 정점별 수질차이가 크게 나타났으며 오염된 상류의 수질이 자정작용에 의하여 개선되다가 다시 생활오수의 유입으로 인하여 악화되는 특이한 양상을 보였다. 모델링 결과 하천의 유속, 유량등의 실측 자료가 부족함에도 불구하고 강릉남대천과 양양남대천은 실측치와 예상치가 높은 상관관계를 나타내었다. 또한 이 모델을 사용하여 강릉남대천의 수질예측을 시도하였다. The water quality was monitored and QUAL-2E modelling was applied in three main stream of Youngdong area. Kangnung Namdaecheon was shown to be a typical stream that the downstream water quality was worse than in the upperstream. Water quality of Yangyang Namdaecheon was better than that of Kangnung Namdaecheon and Samchuk Osipcheon. The spatial variation of water quality was greater than the temporal variation in Samchuk Osipcheon: the polluted upperstream water got better in the midstream, but got worse gain in the downstream. Despite of the lack of suitable measurement data, Kangnung Namdaecheon and Ynagyang Namdaecheon showed good relationship between measured and obtained data: however Samchuk Osipcheon, which had many point sources and much pollution load, showed poor relationship. Based on this model, future water quality of Kangnung Namdaecheon was prospected.

1-aryl-3-aminocarbonylpyridinium 염의 환원

고광희,이재봉 충남대학교 1985 忠南科學硏究誌 Vol.12 No.1

Reduction of 1-aryl-3-aminocarbonylpyridinium salts were investigated. Reduction by sodium dithionite gave 1-aryl-3-aminocarbonyl-1,4-dihydropyridines, while reduction by sodium borohydride yielded 1-aryl-3-aminocarbonyl-1,2-dihydropyridine. Spectroscopic and physical data for the above 1,2-and 1,4-dihydropyridine derivatives were given.

Trapezoidal 구동형 브러시리스 직류 전동기의 최적 정류

禹廣俊,李現彰,庾正鳳 단국대학교 1995 論文集 Vol.29 No.-

In this paper, we analyze the optimal commutation of the trapezoidal driving brushless dc motor which has the trapezoidal flux in the airgap. On the basis of this analysis, we design the hard-wired digital-based optimal commutation control system of the trapezoidal driving brushless dc motor. The optimal commutation circuit consists of a commutation angle ROM, a commutation pattern ROM, and presettable counter. Preposed scheme is simple and quite adequate to the high speed operation. As the analysis shows, we confirm that experimental results show the improved driving characteristics, e. g., the torque is increased over all of the operating range, and the operating range is widely enlarged.

Cupola 용탕을 이용한 CV 주철 제조기술 개발

최광림,최양진,신봉문,강세선 한밭대학교 산업과학기술연구소 1994 논문집 Vol.2 No.-

CV cast iron products was carried out in order to cupola process. CV cast iron products by cupola processing were obtained much more than 50kg/㎣ tensile strength and the excellent structure of CV graphite cast iron and gray cast iron. Casting waster due to the depress of pouring temperature by inoculation was reduced by development (improvement) in cast processing.

慶熙大學校 水源캠퍼스 基本計劃에 關한 硏究

金光來,泰熙成,安奉遠,金東贊 慶熙大學校 1980 論文集 Vol.10 No.-

Recently, in response to the demand for a increased effort in education of leader for the next generation, there has been a significant development in the planning of campus, which is the center of research and academic activities of the coming generation. Therefore, many institutions have tried expanding educational facilities both in terms of quality and quantity. But, there always should be more systematic consideration in drafting a campus master plan so that it can meet the demand of the times and future society. Thus, this research has been attempted in order to be prepared for adaptation to growth and change and to carry out the educational goals international current of studies and the characteristic of Suwon Campus, Kyung Hee University.

운동신경원성질환을 동반한 산발성 크로이츠펠트-야곱병 1예

유봉구,김광수,유경무 대한치매학회 2003 Dementia and Neurocognitive Disorders Vol.2 No.1

Dementia with motor neuron disease includes frontotemporal dementia with motor neuron disease, amyotrophic Creuzfeldt-Jakob disease, Parkinson-amyotrophic lateral sclerosis-dementia complex, familial amyotrophic lateral sclerosis, and hereditary spastic paraparesis. A 54-years-old man presented with a eight month history of rapidly progressive dementia. Progressively more severe dementia was accompanied by muscle wasting and visible fasciculations. Cerebrospinal fluid showed the 14-3-3 protein. Brain MRI revealed mild diffuse atrophy in both frontal, temporal and parietal lobes. He died 9 months after onset of the disease. We report a patient with sporadic Creuzfeldt-Jakob disease with motor neuron disease.