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      • KCI등재

        지주막하출혈에 의한 뇌기저동맥의 형태학적 변화에 미치는 양격산화탕(凉膈散火湯)의 효과

        이동원,이원철,Lee, Dong-Won,Lee, Won-Chul 대한한의학회 1999 대한한의학회지 Vol.20 No.2

        The present study was performed to investigate the effect of Yangkyuksanhoa-tang on the morphological changes of the basilar artery after experimentally induced subarachnoid hemonrrhages(SAH). Yangkyuksanhoa-tang has been used freguently for cerebrovascular accident Sprague Dawley rats weighing between 350-400 g were used. The 6 normal rats and 24 SAH elicited rats were used, The SAH induced by injection of the fresh autologus heart blood (0.3-0.4 ml) into the cisterna magna through the posterior atlanta-occipital membrane, Sample group was given 3.3 ml/kg/day of Yangkyuksanhoa-tang extracts for 2 days after SAH. The experimental animals were killed at 48hrs after SAH. The morphological changes of the arterial walls were examined by light and electron microscopy. Following are the obtained results: 1. In SAH elicited rats, the size of the lumen in basilar artery was diminished by about 45% and the thickness of arterial wall was increased by about 82%. In SAH elicited rats with Yangkyuksanhoa-tang treatment, the size of the lumen in basilar artery was merely diminished by about 18% and the thickness of arterial wall was merely increased by about 19%. 2. In light microscopic examination, the endothelium was swollen into a cuboid shape and the layer of smooth muscle was increased in the basilar artery of SAH elicited rats. In SAH elicited rats with Yangkyuksanhoa-tang treatment, the size of the lumen in basilar artery was enlarged and the thickness was decreased than in SAH elicited rats. The endothelium was flattened into a squamous shape and the layer of smooth muscle was decreased more than in SAH elicited rats. 3. In electron microscopic examination, the endothelial cells with fragmentation nuclei were changed into a cuboid shape and the internal elastic lamina were folded at the basilar artery of SAH elicited rat. The nuclei of smooth muscle cells were changed into a round or crumpled shape. The length of smooth muscle was shorten and thickness was increased. But all kinds of morphologic changes were diminished in SAH elicited rats with Yangkyuksanhoa-tang treatment. Conclusion : Yangkyuksanhoa-tang extracts were effective to treat cerebral vasospasm after experimentally induced subarachnoid hemorrhage in rats.

      • KCI등재

        SHS 공정에 의해 제조된 Mo<sub>x</sub>W<sub>1-x</sub>Si<sub>2</sub> 발열체의 열화메커니즘

        이동원,이상헌,김용남,이성철,구상모,오종민,Lee, Dong-Won,Lee, Sang-Hun,Kim, Yong-Nam,Lee, Sung-Chul,Koo, Sang-Mo,Oh, Jong-Min 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.10

        The degradation mechanism of $Mo_xW_{1-x}Si_2$ ultrahigh-temperature heating elements fabricated by self-propagating high-temperature synthesiswas investigated. The $Mo_xW_{1-x}Si_2$ specimens (with and without post-annealing) were subjected to ADTs (accelerated degradation tests) at temperatures up to $1,700^{\circ}C$ at heating rates of 3, 4, 5, 7, and $14^{\circ}C/min$. The surface loads of all the specimen heaters were increased with the increase in the target temperature. For the $Mo_xW_{1-x}Si_2$ specimens without annealing, many pores and secondary-phase particles were observed in the microstructure; the surface load increased to $23.9W/cm^2$ at $1,700^{\circ}C$, while the bending strength drastically reduced to 242 MPa. In contrast, the $Mo_xW_{1-x}Si_2$ specimens after post-annealing retained $single-Mo_xW_{1-x}Si_2$ phases and showed superior durability after the ADT. Consequently, it is thought that the formation of microcracks and coarse secondary phases during the ADT are the main causes for the degraded performance of the $Mo_xW_{1-x}Si_2$ heating elements without post-annealing.

      • SCOPUSKCI등재

        과배란 처치시 우세난포 조절에 의한 한우 수정란 생산성 향상에 관한 연구 II. 과배란 처치 시기에 따른 난소반응

        이동원,이병천,황우석,Lee, Dong-won,Lee, Byeong-chun,Hwang, Woo-suk 대한수의학회 2000 大韓獸醫學會誌 Vol.40 No.4

        This study was investigated the ovarian response following superovulation treatment at different day of diestrus. The criterion for the presence or absence of a dominant follicle based on their morphological examination. Dominant follicle was puntured 48 hrs before the oneset of superovulation treatment by ultrasonography guided aspiration needle. Superovulation was induced by subcutaneous administration of FSH twice a day for 4 day in a decreasing regimen. There was no significant different between presence of dominont follicle and progesterone concentration/diameter of corpus luteum in HanWoo. Number of corpus luteum of donor after superovulation treatment was not significantly different in FSH administration at day 9, 11 and day 13 of estrus($14.5{\pm}4.5$, $15.5{\pm}5.6$ and $11.0{\pm}5.5$, respectively). But, the diameter of CL was significantly correlate(R2 = 0.757) with progesterone levels on day of superovulatory induction. After 7 days of artificial insemination, the embryos at 7 days were collected by uterine flushing after dominant follicle aspiration and superovulation treatment, and evaluated their quality by morphological criteria. Fifty five embryos with excellent, good and fair grade were transferred into 24 recipient cows. Seventeen offsprings, 1 of triplet, 4 of twins and 6 of singlet, were yield from 10 recipient cow. In conclusion, the present study showed that 1) dominant follicle can be determined by ultrasonography with rectal palpation by morphological evaluations, 2) superovulation response after follicular aspiration was not differ at day 9, 11 and 13 of estrus, 3) dominant follicle did not affect to progesterone concentration and diameter of CL, and 4) diameter of CL was significantly correlate to the level of progesterone concentrations in HanWoo.

      • KCI등재

        화학기상응축공정에 의한 WS<sub>2</sub> 나노입자의 합성 및 특성평가

        이동원,김주형,올레그토로츠코,윤중열,김병기,Lee, Dong-Won,Kim, Ju-Hyeong,Tolochko, O.,Yun, Jung-Yeul,Kim, Byung-Kee 한국분말야금학회 2008 한국분말재료학회지 (KPMI) Vol.15 No.4

        Nano-sized tungsten disulfide ($WS_2$) powders were synthesized by chemical vapor condensation (CVC) process using tungsten carbonyl ($W(CO)_6$) as precursor and vaporized pure sulfur. Prior to the synthesis of tungsten disulfide nanoparticles, the pure tungsten nanoparticles were produced by same route to define the optimum synthesis parameters, which were then successfully applied to synthesize tungsten disulfide. The influence of experimental parameters on the phase and chemical composition as well as mean size of the particles for the produced pure tungsten and tungsten disulfide nanoparticles, were investigated.

      • KCI등재

        탄탈륨 산화물의 마그네슘 가스환원에 의한 탄탈륨 금속분말 제조

        이동원,Lee, Dong-Won 한국분말야금학회 2018 한국분말재료학회지 (KPMI) Vol.25 No.5

        Metallic tantalum powder is manufactured by reducing tantalum oxide ($Ta_2O_5$) with magnesium gas at 1,073-1,223 K in a reactor under argon gas. The high thermodynamic stability of magnesium oxide makes the reduction reaction from tantalum oxide into tantalum powder possible. The microstructure after the reduction reaction has the form of a mixture of tantalum and magnesium oxide, and the latter could be entirely eliminated by dissolving in weak hydrochloric acid. The powder size in SEM microstructure for the tantalum powder increases after acid leaching in the range of 50-300 nm, and its internal crystallite sizes are observed to be 11.5 to 24.7 nm with increasing reduction temperatures. Moreover, the optimized reduction temperature is found to be 1,173 K as the minimum oxygen concentration is approximately 1.3 wt.%.

      • KCI등재

        치매(痴呆)에 관(關)한 동서의학적(東西醫學的) 비교(比較) 고찰(考察)

        이동원,신길조,이원철,Lee, Dong-Weon,Shin, Gil-Jo,Lee, Won-Chul 대한한방내과학회 1995 大韓韓方內科學會誌 Vol.16 No.1

        This study was done in order to investigate the etiology and pathology of dementia in the variety literature. Dementia in elderly persons(above the age of 60) mainly classfied Alzheimer disease and Cerebral vascular dementia. The results were as follows: 1. Dementia patients have abnormal mental function, who have no mental weakness but defects of memory, verbal disturbance, behavior disturbance and loss of intellectual function. 2. Dementia regard as 'me-beng(?病)', 'jeon-gwang(癲狂)', and 'heo-ro(虛勞)' in oriental medicine and the symptom is a silence with no response, mixing, a crying or a laugh, a stranger behavior and a amnesia; disturbances of speech, emotion, behavior. 3. Dementia caused by Alzheimer disease, Multi infarct dementia, Parkinson's disease, sequelae of acute CO poisoning, head injury and alcoholism(occidental medically) and the 'Dam(痰) and Damhwa(痰火), weakness of heart and spleen(心脾虛) caused by pent up anger of seven emotions(七情鬱結), the weakness of liver and kidney(肝腎不足)(oriental medically). 4. The causes of Alzheimer disease are various; a heredity factor, a morphological factor of brain tissues, a psychological factor and a biochemical factor (occidental medically) ; the 'Dam(痰) and Damhwa(痰火) caused by weakness of the internal organs and disturbance of the emotions(oriental medically). 5. Cerebral vascular dementia caused by loss of the certain cerebral neurons and oriental medically caused by obstruction of 'dam(痰)' or 'eo heul(瘀血)'. It is recommended that further study of many sided investigations, specially against a weakness of spiritual functions and a certain neurotoxin in the future.

      • KCI등재

        서양의 역사적인 지도제작법의 발달 과정과 수학적 지식의 상호 영향 관계를 통해 본 직교좌표계

        이동원,Lee, Dong Won 한국수학사학회 2012 Journal for history of mathematics Vol.25 No.4

        역사적인 지도제작법에 나타난 좌표계와 수학적 직교좌표계의 발전 과정을 비교하면서 위치를 표시하는 직교좌표계는 수학의 해석기하학과는 상관없이 인간 본연에 내재되어 있었던 공간지각능력의 일환으로 발전되어 왔음을 주장한다. 지도제작법의 발전이 해석기하학의 발명 전후 삼각함수, 로그, 기하학, 미적분학, 통계학 등 수학의 여러 분야와 상호 영향을 미치지만 원점의 표시나 음수 좌표의 사용과 같은 수학적 직교좌표계 자체에 대한 발전은 데카르트의 논문 발표 후 100여년 이상 지난 후에 이루어지는 점, 해석기하학을 발명하는데 공헌한 대부분의 수학자들이 당대의 문제 해결에 집중하면서 직교좌표계에 대한 수학적 설명없이 자연스럽게 사용하였던 점을 바탕으로 이런 결론을 얻는다. By comparing the development history of rectangular coordinate system in Cartography and Mathematics, we assert in this manuscript that the rectangular coordinate system is not so much related to analytic geometry but comes from the space perceiving ability inherent in human beings. We arrived at this conclusion by the followings: First, although the Cartography have much influenced to various area of Mathematics such as trigonometry, logarithm, Geometry, Calculus, Statistics, and so on, which were developed or progressed around the advent of analytic geometry, the mathematical coordinate system itself had not been completely developed in using the origin or negative axis until 100 years and more had passed since Descartes' publication. Second, almost mathematicians who contributed to the invention of rectangular coordinate system had not focused their studying on rectangular coordinate system instead they used it freely on solving mathematical problem.

      • 특집 : 극한환경재료기술 - 지르코늄 금속의 제조 및 개발 동향

        이동원,Lee, Dong-Won 재료연구소 2010 機械와 材料 Vol.21 No.4

        지르코늄은 지구상에 9번째로 풍부한 금속소재이며, 어느 금속소재 보다는 우수한 내식성을 보유하고 있으며 기계적 특성 및 열전도도가 기존의 SUS 계 및 Ti 계 소재와 유사한 특징이 있기 때문에, 핸드폰, 보철재료, 합성섬유, 석유화학 공업용 부품에 널리 사용되고 있다. 지르코늄 부품제조를 위해서는 무엇보다도 초기 금속원자재의 생산기술 확보가 선행되어야 한다. 즉, 초기 금속원자재인 지르코늄 금속스폰지의 제조기술의 확보가 필요하다. 본 고에서는 지르코늄 금속의 용도, 산업동향, 지르코늄 스폰지 제조기술 및 최근 연구개발 동향에 대해 간략히 소개하였다.

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