• Title/Summary/Keyword: 3A

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Fabrication and Oxygen Permeation Properties of ${La_{1-x}Sr_{x}B_{1-{\gamma}}Fe_{\gamma}O_{3-{\delta}}$(B=Co, Ga) Perovskite-Type Ceramic Membranes (${La_{1-x}Sr_{x}B_{1-{\gamma}}Fe_{\gamma}O_{3-{\delta}}$(B=Co, Ga) 페롭스카이트 세라믹 분리막의 제조 및 산소투과특성)

  • 임경태;조통래;이기성;한인섭;서두원
    • Membrane Journal
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    • v.11 no.4
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    • pp.143-151
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    • 2001
  • We have fabricated mixed-ionic conducting membranes, L $a_{0.6}$S $r_{0.4}$ $Co_{0.2}$F $e_{0.8}$ $O_{3-}$$\delta$/ and L $a_{0.7}$S $r_{0.3}$G $a_{0.6}$F $e_{0.4}$ $O_{3-}$$\delta$/ by the solid state method. Ceramic membranes consisted of perovskite-type structures and exhibited high relative density, >95%. Especially, dense L $a_{0.6}$S $r_{0.4}$Co $O_{3-}$$\delta$/ layer was coated on the L $a_{0.7}$S $r_{0.3}$G $a_{0.6}$F $e_{0.4}$ $O_{3-}$$\delta$/ membranes by using screen printing technique in order to improve oxygen ion flux. We measured oxygen ion flux on uncoated L $a_{0.6}$S $r_{0.4}$ $Co_{0.2}$F $e_{0.8}$ $O_{3-}$$\delta$/, uncoated L $a_{0.7}$S $r_{0.3}$G $a_{0.6}$F $e_{0.4}$ $O_{3-}$$\delta$/, and coated L $a_{0.7}$S $r_{0.3}$G $a_{0.6}$F $e_{0.4}$ $O_{3-}$$\delta$/ membranes. The L $a_{0.6}$S $r_{0.4}$ $Co_{0.2}$F $e_{0.8}$ $O_{3-}$$\delta$/ membranes showed the highest flux, 0.26 mL/min.$\textrm{cm}^2$ at 90$0^{\circ}C$, after steady state had been reached. The oxygen flux of coated L $a_{0.7}$S $r_{0.3}$G $a_{0.6}$F $e_{0.4}$ $O_{3-}$$\delta$/ membranes showed higher value, 0.19 mL/min.$\textrm{cm}^2$ at 95$0^{\circ}C$. This flux was as much as 2 or 3 times higher than those of uncoated L $a_{0.7}$S $r_{0.3}$G $a_{0.6}$F $e_{0.4}$ $O_{3-}$$\delta$/ membranes. 3-$\delta$/ membranes.X> 3-$\delta$/ membranes.membranes.

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A Systematic Construction Process of 3D Database for Realtime Virtual Simulation of Transportation Equipments (수송장비의 실시간 가상 시뮬레이션을 위한 3차원 데이터베이스의 체계적인 구축 프로세스)

  • Kim, Bo-Hyun
    • IE interfaces
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    • v.16 no.2
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    • pp.258-267
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    • 2003
  • Recently, virtual reality technologies have been rapidly developed and realtime virtual simulation methods have been extensively employed for several application areas such as game, sports, manufacturing, military, and so on. A 3D database in realtime virtual simulation plays a key role because it makes users feel reality in virtual space. In a application view of 3D database, a systematic construction approach is required to reduce its construction time and increase its quality. However, many researches have been mostly focused on realtime graphic issues and its key technologies. In virtual simulation of transportation equipments, this paper proposes a systematic construction process of 3D database consisting of four stages as follows: 1) determine the activity space of a equipment, 2) collect data related to 3D database construction, 3) make a 3-dimensional modeling strategy, and 4) generate and evaluate a 3D model. This paper also introduces a new procedure of 3D environment modeling, which summarizes and expands our modeling experiences, to be used as a modeling guide.

Two Crystal Structures of $Tl^+$ and $Zn^{2+}$ Exchanged Zeolite A, $Tl_{12-2x}Zn_x-A$ (x=4.3 and 3.25)

  • Mi Suk Jeong;Seong Hwan Song;Young Wook Han;Yang Kim
    • Bulletin of the Korean Chemical Society
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    • v.11 no.2
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    • pp.150-154
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    • 1990
  • The structures of $Tl_{12-2x}Zn_x-A$ (x = 4.3 and 3.25), vacuum dehydrated zeolite A with all $Na^+$ ions replaced by $Tl^+$ and $Zn^{2+}$ as indicated, have been determined by single-crystal X-ray diffraction techniques in cubic space group Pm3m at 21(1) $^{\circ}C$ (a=12.100(2) ${\AA}$ for $Tl_{3.4}Zn_{4.3}-A$ and a=12.092(2) ${\AA}$ for $Tl_{5.5}Zn_{3.25}-A$). The crystals of $Tl_{3.4}Zn_{4.3}-A$ and $Tl_{5.5}Zn_{3.25}-A$ were prepared by flow method using exchange solutions in which mole ratios of $TlNO_3$,/TEX> and $Zn(NO_3)_2$ were 1:50 and 1:1, respectively, with total concentration of 0.05 M. The structures of the dehydrated $Tl_{3.4}Zn_{4.3}-A$ and $Tl_{5.5}Zn_{3.25}-A$ were refined to yield the final error indices $R_1$ = 0.075 and $R_2$ = 0.075 with 236 reflections, and $R_1$ = 0.057 and $R_2$ = 0.064 with 202 reflections, respectively, for which I > 3$\sigma$(I). Both structures indicate that Zn(II) ions are coordinated by three framework oxygens: the Zn(II) to O(3) distances are 2.08(1) ${\AA}$ for $Tl_{3.4}Zn_{4.3}-A$ and 2.07(1) ${\AA}$ for $Tl_{5.5}Zn_{3.25}-A$, respectively. In each structure, the angle subtended at Zn(II), O(3)-Zn(II)-O(3) is 119.9(3)$^{\circ}$ for $Tl_{3.4}Zn_{4.3}-A$, and 120.0(3)$^{\circ}$ for $Tl_{5.5}Zn_{3.25}-A$, respectively, close to the idealized trigonal-planar value. Zn(II) ions prefer to 6-ring sites. $Tl^+$ ions do not have any preference to a particular site but occupy simultaneously both at the 6-ring sites and 8-ring sites.

Allelic Variation of Glutenin, Granule-Bound Starch Synthase l and Puroindoline in Korean Wheat Cultivar

  • Park, Chul-Soo;Pena, Roberto J.;Baik, Byung-Kee;Kang, Chon-Sik;Heo, Hwa-Young;Cheong, Young-Keun;Woo, Sun-Hee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.54 no.2
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    • pp.181-191
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    • 2009
  • To investigate the genetic variation of high-and low-molecular-weight glutenin subunits (BMW-GS and LMW-GS), granule-bound starch synthase I (GBSSI) and puroindoline in 24 Korean wheat cultivars. At the BMW-GS compositions, three Glu-A1 alleles, five Glu-B1 alleles and three Glu-D1 alleles were identified. The high frequency of alleles at each locus was Glu-A1c allele (15 cultivars), Glu-B1b allele (16 cultivars) and Glu-D1f allele (16 cultivars). Four alleles were identified at the Glu-A3 and Glu-B3 loci and three at Glu-D3 locus and Glu-A3d, Glu-B3d and Glu-D3a were mainly found at each Glu-3 locus. Glu-A3d, Glu-B3d, Glu-D3b or c (4 cultivars, respectively) and Glu-A3d, Glu-B3d, Glu-D3a and Glu-A3c, Glu-B3d or h, Glu-D3a (3 cultivar, respectively) were predominantly found in Korean wheats. At the GBSS compositions, 2 waxy wheat cultivars, Shinmichal and Shinmichal1, showed null alleles on the Wx loci and other cultivars were wild type in GBSS compositions. At the puroindoline gene compositions, Korean wheat cultivars carried 3 genotypes, which 10 cultivars (41.7%) were Pina-D1a and Pinb-D1a, 11 cultivars (45.8%) had Pina-D1a and Pinb-D1b and 3 cultivars (12.5%) carried Pina-D1b and Pinb-D1a. These genetic variations could present the information to improve flour and end-use quality in Korean wheat breeding programs.

A Hierarchical User Interface for Large 3D Meshes in Mobile Systems (모바일 시스템의 대용량 3차원 메쉬를 위한 계층적 사용자 인터페이스)

  • Park, Jiro;Lee, Haeyoung
    • Journal of the Korea Computer Graphics Society
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    • v.19 no.1
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    • pp.11-20
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    • 2013
  • This paper introduces a user interface for large 3D meshes in mobile systems, which have limited memory, screen size and battery power. A large 3D mesh is divided into partitions and simplified in multi-resolutions so a large file is transformed into a number of small data files and saved in a PC server. Only selected small files specified by the user are hierarchically transmitted to the mobile system for 3D browsing and rendering. A 3D preview in a pop-up shows a simplified mesh in the lowest resolution. The next step displays simplified meshes whose resolutions are automatically controlled by the user interactions. The last step is to render a set of detailed original partitions in a selected range. As a result, while minimizing using mobile system resources, our interface enables us to browse and display 3D meshes in mobile systems through real-time interactions. A mobile 3D viewer and a 3D app are also presented to show the utility of the proposed user interface.

Chelidonium majus Induces Apoptosis of Human Ovarian Cancer Cells via ATF3-Mediated Regulation of Foxo3a by Tip60

  • Shen, Lei;Lee, Soon;Joo, Jong Cheon;Hong, Eunmi;Cui, Zhen Yang;Jo, Eunbi;Park, Soo Jung;Jang, Hyun-Jin
    • Journal of Microbiology and Biotechnology
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    • v.32 no.4
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    • pp.493-503
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    • 2022
  • Forkhead transcription factor 3a (Foxo3a) is believed to be a tumor suppressor as its inactivation leads to cell transformation and tumor development. However, further investigation is required regarding the involvement of the activating transcription factor 3 (ATF3)-mediated Tat-interactive protein 60 (Tip60)/Foxo3a pathway in cancer cell apoptosis. This study demonstrated that Chelidonium majus upregulated the expression of ATF3 and Tip60 and promoted Foxo3a nuclear translocation, ultimately increasing the level of Bcl-2-associated X protein (Bax) protein. ATF3 overexpression stimulated Tip60 expression, while ATF3 inhibition by siRNA repressed Tip60 expression. Furthermore, siRNA-mediated Tip60 inhibition significantly promoted Foxo3a phosphorylation, leading to blockade of Foxo3a translocation into the nucleus. Thus, we were able to deduce that ATF3 mediates the regulation of Foxo3a by Tip60. Moreover, siRNA-mediated Foxo3a inhibition suppressed the expression of Bax and subsequent apoptosis. Taken together, our data demonstrate that Chelidonium majus induces SKOV-3 cell death by increasing ATF3 levels and its downstream proteins Tip60 and Foxo3a. This suggests a potential therapeutic role of Chelidonium majus against ovarian cancer.

Effect of methylsulfonylmethane on oxidative stress and CYP3A93 expression in fetal horse liver cells

  • Kim, Kyoung Hwan;Park, Jeong-Woong;Yang, Young Mok;Song, Ki-Duk;Cho, Byung-Wook
    • Animal Bioscience
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    • v.34 no.2
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    • pp.312-319
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    • 2021
  • Objective: Stress-induced cytotoxicity caused by xenobiotics and endogenous metabolites induces the production of reactive oxygen species and often results in damage to cellular components such as DNA, proteins, and lipids. The cytochrome P450 (CYP) family of enzymes are most abundant in hepatocytes, where they play key roles in regulating cellular stress responses. We aimed to determine the effects of the antioxidant compound, methylsulfonylmethane (MSM), on oxidative stress response, and study the cytochrome P450 family 3 subfamily A (CYP3A) gene expression in fetal horse hepatocytes. Methods: The expression of hepatocyte markers and CYP3A family genes (CYP3A89, CYP3A93, CYP3A94, CYP3A95, CYP3A96, and CYP3A97) were assessed in different organ tissues of the horse and fetal horse liver-derived cells (FHLCs) using quantitative reverse transcription polymerase chain reaction. To elucidate the antioxidant effects of MSM on FHLCs, cell viability, levels of oxidative markers, and gene expression of CYP3A were investigated in H2O2-induced oxidative stress in the presence and absence of MSM. Results: FHLCs exhibited features of liver cells and simultaneously maintained the typical genetic characteristics of normal liver tissue; however, the expression profiles of some liver markers and CYP3A genes, except that of CYP3A93, were different. The expression of CYP3A93 specifically increased after the addition of H2O2 to the culture medium. MSM treatment reduced oxidative stress as well as the expression of CYP3A93 and heme oxygenase 1, an oxidative marker in FHLCs. Conclusion: MSM could reduce oxidative stress and hepatotoxicity in FHLCs by altering CYP3A93 expression and related signaling pathways.

SOME REMARKS ON NON-SYMPLECTIC AUTOMORPHISMS OF K3 SURFACES OVER A FIELD OF ODD CHARACTERISTIC

  • Jang, Junmyeong
    • East Asian mathematical journal
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    • v.30 no.3
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    • pp.321-326
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    • 2014
  • In this paper, we present a simple proof of Corollary 3.3 in [5] using the fact that for a K3 surface of finite height over a field of odd characteristic, the height is a multiple of the non-symplectic order. Also we prove for a non-symplectic CM K3 surface defined over a number field the Frobenius invariant of the reduction over a finite field is determined by the congruence class of residue characteristic modulo the non-symplectic order of the K3 surface.

A Study on the Speed Control System of a 3 phase Induction Motor driven by the Full Bridge Inverter with a Low Pass LC Filter (저역통과 LC필터를 가진 전브리지형 인버터로 구동되는 3상유동전동기의 속도제어 시스템에 관한 연구)

  • 박진길
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.4
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    • pp.538-550
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    • 1998
  • The variable frequency and variable voltage AC source made by a conventional inverter which is composed of power semi-conductors includes much noises in sine wave due to high frequency switching of DC source. In this paper the 3rd low pass LC filter for a variable speed 3 phase induction motor driven by a full bridge inverter is introduced to solve the EMI problem by serious noise current. The utility of a modified 3rd order Butterworth LC filter is confirmed through FFT analysis of sine waves and noiseless ACsource can be obtained by the proposed LC filter. The speed of a 3 phase induction motor driven by a full bridge inverter with a LC filter is satisfactorily controlled by a digital PID controller under the condition of stepwise load and setpoint changes.

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Structures of Fraxinellone Derivatives by Hydrogenation with $PtO_2$ in HOAc (백선피의 성분 Fraxinellone의 백금산 촉매에 의한 환원물질의 구조)

  • Kim, Ju Sun;Kang, Sam Sik
    • Korean Journal of Pharmacognosy
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    • v.44 no.1
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    • pp.6-9
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    • 2013
  • Two fraxinellone-based hydrogenated derivatives were prepared from fraxinellone, a well-known degraded limonin, via catalytic hydrogenation in the presence of $PtO_2$ in HOAc. Their structures were confirmed as (3S,3aR,3'R)-3a,7-dimethyl-3-(tetrahydrofuran-3-yl)-3a,4,5,6-tetrahydroisobenzofuran-1(3H)-one and (3S,3aR,2'R)-3-((R)-1-hydroxybutan-2-yl)-3a,7-dimethyl-3a,4,5,6-tetrahydroisobenzofuran-1(3H)-one on the basis of 2D NMR assignments. The $^{13}C$ NMR assignments of two quaternary carbons in the ${\alpha}$,${\beta}$-unsaturated carbonyl moiety of ${\gamma}$-butyrolactone core of fraxinellone should be revised.