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.

SHS 공정에 의해 제조된 Mo_xW_1-xSi₂ 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.

단조 산화스케일로부터 철계분말 제조 기술개발 연구

이동원,윤중열,신선명,김인수,왕제필,Lee, Dong-Won,Yun, Jung-Yeul,Shin, Shun-Myung,Kim, In-Soo,Wang, Jei-Pil 한국분말야금학회 2013 한국분말재료학회지 (KPMI) Vol.20 No.3

The study on the fabrication of iron powder from forging scales using hydrogen gas has been conducted on the effect of hydrogen partial pressure, temperature, and reactive time. The mechanism for the reduction of iron oxides was proposed with various steps, and it was found that reduction pattern might be different depending on temperature. The iron content in the scale and reduction ratio of oxygen were both increased with increasing reactive time at 0.1atm of hydrogen partial pressure. On the other hand, for over 30 minutes at 0.5 atm of hydrogen partial pressure, the values were found to be almost same. In the long run, iron metallic powder was obtained with over 90% of iron content and an average size of its powder was observed to be about $100{\mu}m$.

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.

러시아 티타늄계 고융점 화합물 분말합성 신기술

이동원,김병기,Lee, Dong-Won,Kim, Byeong-Gi 재료연구소 2004 機械와 材料 Vol.16 No.1

금속환원법에 의한 바나듐 분말 추출

이동원,허상현,염종택,왕제필,Lee, Dong-Won,Heo, Sang-Hyun,Yeom, Jong-Taek,Wang, Jei-Pil 한국분말야금학회 2013 한국분말재료학회지 (KPMI) Vol.20 No.1

The extraction of metallic pure vanadium powder from raw oxide has been tried by Mg-reduction. In first stage, $V_2O_5$ powders as initial raw material was reduced by hydrogen gas into $V_2O_3$ phase. $V_2O_3$ powder was reduced in next stage by magnesium gas at 1,073K for 24 hours. After reduction reaction, the MgO component mixed with reduced vanadium powder were dissolved and removed fully in 10% HCl solution for 5 hours at room temperature. The oxygen content and particle size of finally produced vanadium powders were 0.84 wt% and 1 ${\mu}m$, respectively

마그네슘 열환원에 의한 저응집 초미립 TiCN 분말합성

이동원,Lee, Dong-Won 한국분말야금학회 2012 한국분말재료학회지 (KPMI) Vol.19 No.5

The ultra-fine and less agglomerated titanium carbonitride particles were successfully synthesized by magnesiothermic reduction with low feeding rate of $TiCl_4+1/4C_2Cl_4$ solution. The sub-stoichiometric titanium carbide ($TiC_{0.5{\sim}0.6}$) particles were produced by reduction of chlorine component by liquid magnesium at $800^{\circ}C$ of gaseous $TiCl_4+1/4C_2Cl_4$ and the heat treatments in vacuum were performed for 5 hours to remove the residual magnesium and magnesium chloride mixed with produced $TiC_{{\sim}0.5}$. The final $TiC_{{\sim}0.5}N_{0{\sim}0.5}$ particle with near 100 nm in mean size and high specific surface area of $65m^2/g$ was obtained by nitrification under nitrogen gas at $1,150^{\circ}C$ for 2 hrs.

무한강하법을 이용한 증명지도의 연구

이동원,김부윤,정영우,Lee, Dong Won,Kim, Boo Yoon,Chung, Young Woo 영남수학회 2016 East Asian mathematical journal Vol.32 No.2

There are three subjects in the study. First, after investigating the development process of the method of infinite descent and the reduction to absurdity, we prove them to be equivalent each other. Second, we apply the method of infinite descent to some problems in textbook and compare it with the reduction to absurdity. Finally, we discuss on teaching proofs with the method of infinite descent.

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.

입자 사이즈에 따른 Cu 필름의 에어로졸 성막 거동에 대한 연구

이동원,오종민,Lee, Dong-Won,Oh, Jong-Min 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.4

The effect of particle sizes on the aerosol deposition (AD) of Cu films is investigated in order to understand the deposition behaviors of metal powder during the AD process. The Cu coatings fabricated by using $2{\mu}m$ Cu powders had a dense microstructure, a high deposition rate ($1.6{\pm}0.2{\mu}m/min$), and low resistance ($9.42{\pm}0.4{\mu}{\Omega}{\cdot}cm$) compared to that from using Cu powder with a particle size greater than $5{\mu}m$. Also, from estimating the internal micro-strain of Cu films, the Cu coatings fabricated by using $2{\mu}m$ Cu particles exhibited a high micro-strain value of $3.307{\times}10^{-3}$. On the other hand, the strain of Cu coatings fabricated with $5{\mu}m$ particles was decreased to $2.76{\times}10^{-3}$. These results seem to show that the impacted Cu particles are compressed and flattened by shock waves, and that their bonding is associated with the high internal micro-strain caused by plastic deformation.