http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Computational fluid dynamics of NiTi stents for Cerebral Aneurysm prevention
Hyo-Geun Nam(남효근),Chang-Min.Yoo(유창민),Jae-Hee Shin(신재희),Min-Ho Hwang(황민호),Seung-Min Baek(백승민),Jung-Hoon Park(박정훈),Jin-Su Jeong(정진수),Jae-Won Lee(이재원),Hyuk Choi(최혁) 대한전자공학회 2016 대한전자공학회 학술대회 Vol.2016 No.6
Stents are significant medical devices broadly used in the prevention of cerebral aneurysm rupture. The performance of stents depends on their mechanical properties and cell configuration, thus, the aim of this study is the optimization of stent design and test the hemodynamic properties by using computational solid mechanics and computational fluid dynamics. In performance tests, computer-based cerebral aneurysm models of human brain were tested. closed-cell type was selected as the strut configuration, and nitinol was chosen as the material due to its flexibility. Three types of ideal samples with different cell configurations were manufactured. There were over 30% difference in results of flexibility in computational solid mechanics analysis. Moreover, in cerebral aneurysm model simulation, we investigated that stent insertion eased the hemodynamic factors of the cerebral aneurysm and reduced the flow velocity influx into the sac. A reduction in flow velocity led to a 50–60% reduction in wall shear stress, which is expected to aid aneurysm rupture prevention under clinical conditions.
Effects of Repeated Seafood Consumption on Urinary Excretion of Arsenic Species by Volunteers
Choi, Byung-Sun,Choi, Seong-Jin,Kim, Dong-Won,Huang, Mingai,Kim, Na-Young,Park, Kyung-Su,Kim, Choong-Yong,Lee, Hyo-Min,Yum, Young-Na,Han, Eui-Sik,Kang, Tae-Seok,Yu, Il-Je,Park, Jung-Duck Springer-Verlag 2010 Archives of environmental contamination and toxico Vol.58 No.1
Effects on the Carbon Matrix as Conductor in Sulfur Electrode for Lithium/Sulfur Battery
Choi, Young Jin,Jeong, Sang Sik,Kim, Ki Won,Ahn, Hyo Jun,Ahn, Jou Hyeon Trans Tech Publications, Ltd. 2006 Materials science forum Vol.510 No.-
<P>Lithium/sulfur battery has some problems such as low utilization of active material and poor cycle life owing to the dissolution of lithium polysulfide into electrolyte, aggregation of sulfur during charge-discharge process, and structural change of sulfur electrode. To overcome such problems, carbon nano tubes (CNTs) and graphitic nano fibers (GNFs) were added into the sulfur electrode. The addition of CNTs and GNFs having a network-like structure is expected to offer the structural stability and good electrical path of sulfur electrode. The morphology of fabricated sulfur electrode was observed by using scanning electron microscope (SEM), and the crystalline structure was characterized by using X-ray diffraction (XRD). The charge/discharge tests were conducted in the voltage range 3.2/1.5V (vs.Li) with a galvanostatic method.</P>
Choi, In-Young,Jeong, Hyun-Ja,An, Hyo-Jin,Kang, Tae-Hee,Zo, Chul-Won,Song, Bong-Keun,Park, Eun-Jeong,Kim, Eun-Cheol,Um, Jae-Young,Kim, Hyung-Min,Hong, Seung-Heon Kyung Hee Oriental Medicine Research Center 2008 Oriental pharmacy and experimental medicine Vol.8 No.4
This study investigated the role of Panax ginseng (PG) on the phorbol myristate acetate (PMA) + calcium ionophore A23187-induced hypoxia-inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) activation, phosphorylation of the extracellular signal-regulated kinase (ERK), and inflammatory cytokine production from the human mast cell line, HMC-1. HIF-$1{\alpha}$ and phosphorylation of ERK were observed by Western blotting. The inflammatory cytokine production was determined by enzyme-linked immunosorbent assay. PG inhibited the PMA+A23187-induced HIF-$1{\alpha}$ expression and the subsequent production of vascular endothelial growth factor. In addition, PG suppressed PMA + A23187-induced phosphorylation of ERK. We also show that the increased cytokines interleukin (IL)-$1{\beta}$, IL-6, and tumour necrosis factor-${\alpha}$ level was significantly inhibited by treatment of PG. In the present study, we report for the first time that PG is an inhibitor of HIF-$1{\alpha}$ and cytokines on the mast cell-mediated inflammatory responses.
Won, Dong-Seon,Kim, Jin-Hyang,No, Hyo Jin,Cho, You Jin,Lee, Ju-Yeon,Rhee, Bum Ku,Choi, Hee-Dok John Wiley Sons, Ltd. 2010 Polymer international Vol.59 No.2
<P>Stabilization of electrically induced dipole alignment is one of the important criteria in the development of nonlinear optical (NLO) polymers for electro-optic device applications. Polyurethanes for NLO applications have attracted attention because of their high thermal stability due to hydrogen bonding. In the work reported here, we designed and synthesized a new type of NLO polyurethane, in which the pendant NLO chromophores are part of the polymer backbone. This mid-type NLO polymer is expected to have the merits of both main-chain and side-chain NLO polymers, namely stable dipole alignment and good solubility. 1-[3,4-Di-(2-hydroxyethoxy)phenyl]-2-(2-thienyl)ethene was prepared and condensed with 3,3′-dimethoxy-4,4′-biphenylenediisocyanate to yield a polyurethane. This polyurethane was reacted with tetracyanoethylene to give a novel Y-type polyurethane (7) containing 1-(3,4-dioxyphenyl)-2-[5-(1,2,2-tricyanovinyl)-2-thienyl]ethenes as NLO chromophores, which constitute part of the polymer backbone. Polyurethane 7 is soluble in common organic solvents such as N,N-dimethylformamide and dimethylsulfoxide. It shows a thermal stability up to 280 °C from thermogravimetric analysis with a glass transition temperature obtained from differential scanning calorimetry of ca 162 °C. The second harmonic generation (SHG) coefficient (d<SUB>33</SUB>) of a poled polymer film of he polyurethane at 1560 nm fundamental wavelength is ca 1.11 × 10<SUP>−18</SUP> C. Polymer 7 exhibits an enhanced thermal stability and no significant SHG decay is observed below 150 °C, which is acceptable for NLO device applications. Copyright © 2009 Society of Chemical Industry</P> <B>Graphic Abstract</B> <P>A novel Y-type polyurethane containing 1-(3,4-dioxyphenyl)-2-{5-(1,2,2-tricyanovinyl)-2-thienyl}ethenes as NLO-chromophores exhibited SHG coefficient (d<SUB>33</SUB>) of 1.11 × 10<SUP>−18</SUP> C at 1560 nm fundamental wavelength with enhanced thermal stability of SHG up to 150°C, which is acceptable for nonlinear optical device applications. <img src='wiley_img/09598103-2010-59-2-PI2702-gra001.gif' alt='wiley_img/09598103-2010-59-2-PI2702-gra001'> </P>
Choi, Chel-Jong,Kang, Seung-Min,Hong, Hyo-Bong,Lee, Soo-Hyung,Kim, Jin-Gyu,Ahn, Kwang-Soon,Yoon, Jong-Won The Japan Institute of Metals 2010 MATERIALS TRANSACTIONS Vol.51 No.4
<P>We fabricated metal-oxide-semiconductor (MOS) devices with a high-k Er-silicate gate dielectric, and demonstrated their electrical performance. The increase in the rapid thermal annealing (RTA) temperature leads to a reduction of the equivalent oxide thickness (EOT), which is attributed in par to the thickness evolution of Er-silicate film and to the chemical bonding change from an Si-rich to an Er-rich silicate. The <I>in-situ</I> investigation of the interfacial reaction between the Er and SiO<SUB>2</SUB> film using a high-voltage electron microscopy (HVEM) revealed a linear relationship between the squared thickness of Er-silicate layer and <I>in-situ</I> annealing time, indicating that the Er-silicate growth is a diffusion-controlled process. The parabolic growth constants of the Er-silicate film were calculated to be 2.3×10<SUP>−16</SUP> and 9.3×10<SUP>−16</SUP> cm<SUP>2</SUP>/s for <I>in-situ</I> annealing temperatures of 350 and 450°C, respectively.</P>
Choi, Jae Won,Cheruvally, Gouri,Ahn, Jou Hyeon,Kim, Ki Won,Ahn, Hyo Jun Trans Tech Publications, Ltd. 2007 Materials science forum Vol.544 No.-
<P>Iron, sulfur and transition metal powders were used as the starting materials to prepare iron disulfide (FeS2) cathode material at room temperature by high energy mechanical alloying. Modified FeS2 were also prepared by incorporation of transition metals like Co and Ni. Li/FeS2 cells with the prepared iron disulfides as cathodes were studied for discharge properties at room temperature using the 0.5M LiTFSI in tetra(ethylene glycol) dimethyl ether (TEGDME). The first discharge capacities of Li/composite FeS2 cell with 5 wt.% Co and 3 wt.% Ni were 571 and 844 mAh/g, respectively, compared to 389 mAh/g for the cell without any additive. The enhanced properties resulted from the better electronic conductivity of the material containing the metallic additive. The initial capacity and cyclic performance were improved when nickel and cobalt were added to prepare the modified iron disulfide.</P>
Choi, Jin-Hyung,Doh, Deog-Hee,Jo, Hyo-Je,Lee, Yeon-Won,Suzuki, Kiyomi,Kato, Shinji 한국가시화정보학회 2010 한국가시화정보학회지 Vol.8 No.2
Flow characteristics of a free-horizontal-axis-turbine (FHAT) current power generation system have been investigated by the use of a volumetric PTV. Three types of FHAT system (S50, SE50, S65) have been tested under the current speed 1.35 knot, 1.5 knot and 2 knot. The width of the blade installed around the body is 50 mm. Based upon the power generation characteristics of the FHAT, the flow features of the blade have been investigated. Among the three models it has been verified that the S65 is the most appropriate for power generations.