• Title/Summary/Keyword: O-D analysis

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Dynamics of OH Production in the Reaction of O(1D2) with Cyclopropane

  • Jang, Sungwoo;Jin, Sung Il;Kim, Hong Lae;Kim, Hyung Min;Park, Chan Ryang
    • Bulletin of the Korean Chemical Society
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    • v.35 no.6
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    • pp.1706-1712
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    • 2014
  • The OH($X^2{\Pi}$, ${\upsilon}^{\prime\prime}=0,1$) internal state distribution following the reaction of electronically excited oxygen atom ($O(^1D_2)$) with cyclo-$C_3H_6$ has been measured using laser-induced fluorescence, and compared with that following the reaction of $O(^1D_2)$ with $C_3H_8$. The overall characteristics of the OH internal energy distributions for both reactions were qualitatively similar. The population propensity of the ${\Pi}(A^{\prime})$ ${\Lambda}$-doublet sub-level suggested that both reactions proceeded via an insertion/elimination mechanism. Bimodal rotational population distributions supported the existence of two parallel mechanisms for OH production, i.e., statistical insertion and nonstatistical insertion. However, detailed analysis revealed that, despite the higher exoergicity of the reaction, the rotational distribution of the OH following the reaction of $O(^1D_2)$ with $C_3H_8$ was significantly cooler than that with cyclo-$C_3H_6$, especially in the vibrational ground state. This observation was interpreted as the effect of the flexibility of the insertion complex and faster intramolecular vibrational relaxation (IVR).

Inhibitory Effects of Flavonoids Isolated from the Leaves of Stewartia koreana on Nitric-oxide Production in LPS-stimulated RAW 264.7 Cells (노각나무 잎에서 분리된 플라보노이드에 의한 대식세포에서 산화질소 생성 억제효과)

  • Lee, Seung-Su;Bang, Myun-Ho;Park, Se-Ho;Chung, Dae-kyun;Yang, Seun-Ah
    • Journal of Life Science
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    • v.28 no.5
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    • pp.509-516
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    • 2018
  • Five phenolic compounds were isolated from the ethyl acetate fraction of leaves from Stewartia koreana, and their nitric-oxide (NO) inhibitory activities were measured to identify the major active constituents responsible for the efficacy of the extract against inflammatory reactions. These five compounds were quercetin (1), quercitrin (2), hyperin (3), quercetin-3-O-(6"-O-galloyl)-${\beta}$-D-galactopyranoside (4), and kaempferol 3-O-[2",6"-di-O-(trans-p-coumaroyl)]-${\beta}$-D-glucopyranoside (5). Among the separated compounds in the EtOAc fraction, compounds 4 and 5 were isolated for the first time, and no study has yet reported their anti-inflammatory effects. The compounds were identified by spectroscopic analysis, and the isolated compounds showed significant NO inhibitory effects in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Compound 5 showed the most potent inhibitory effect (63.35% inhibition) against LPS-induced NO production compared to that of compound 1 (17.17%), compound 2 (5.0%), compound 3 (3.92%), and compound 4 (6.32%) at $10{\mu}g/ml$ concentration. NO production was inhibited by suppressing the protein expression of inducible nitric-oxide synthase in LPS-stimulated RAW 264.7 macrophages. These results indicate that kaempferol 3-O-[2",6"-di-O-(trans-p-coumaroyl)]-${\beta}$-D-glucopyranoside might be the major active compound responsible for the anti-inflammatory effects of S. koreana.

Designed of rPP/d2w®/ZnO Nanocomposite Flexible Film for Food Packaging and Characterization on Mechanical and Antimicrobial Properties (산화분해촉매를 함유한 rPP/ZnO 나노컴포지트 유연식품포장필름 제조 및 물성 특성 연구)

  • Lee, Jin-kyoung;Gil, Bo-min;Lee, Dong-jin;Lee, Ik-mo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.24 no.1
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    • pp.1-11
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    • 2018
  • In this study, pro-oxidant($d2w^{(R)}$) and rPP/ZnO nanocomposite flexible films for food packaging were prepared, and their mechanical and antimicrobial properties were investigated. As a result, the carbonyl index and hydroxyl index increased with exposured time to heat and UV rays. Surface analysis showed that the addition of zinc oxide improved the dispersibility and compatibility of the polymer, so that the surface of the composite film was smooth and the zinc oxide particles were smaller than the compared film. And it kept the physical properties by heat and UV ray blocking effect, and it worked to reduce decomposition. In the antimicrobial activity test, the microbial reduction rate was 3 logs or more at the use concentration of zinc oxide. The tensile strength was increased and the elongation was decreased. Oxidative degradability of multi-layered film in UV exposured for 72 hours, the molecular weight of the film decreased by 75.6%, 1,294 g/mol Mn and 5,920 g/mol Mw. In the safety analysis of food packaging materials, we obtained that are in standard of polypropylene, a food contact material of domestic law.

A Study on Fractal Analysis and 3D Images of Surface on BST Thin Films. (BST 박막 표면의 프랙탈 분석 및 3D 이미지 특성)

  • Hong, Kyung-Jin;Min, Yong-Ki;Cho, Jae-Cheol
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05b
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    • pp.103-106
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    • 2002
  • The applicability of models based on fractal morphology to characterize $(Ba\;Sr)TiO_{3}$ thin film surfaces was investigated. The fractal morphology of coated barium strontium titan oxide thin film surfaces was described using fractal dimension from scanning electro microscopy image. The $(Ba\;Sr)TiO_{3}$ coating were deposited on silicon wafers using $(Ba\;Sr)TiO_{3}$ solution and spin coater. BST solution was composited by mol ratio, and then spin-coated from 3 times to 5 times coating on $Pt/SiO_{2}/Si$ substrate. Qualitative thin film analysis was performed with scanning electro microscopy (SEM), and surfaces parameters such as average grain diameter, roughness exponent and fractal dimension were determined.

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Genotoxicity of $CeO_2$, $SiO_2$ and $TiO_2$ Nanoparticles in the Freshwater Crustacean Daphnia magna (Daphnia magna를 이용한 세리아, 실리카, 티타늄 나노물질의 유전독성 평가)

  • Kim, Sung-Man;Choi, Jin-Hee
    • Environmental Analysis Health and Toxicology
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    • v.23 no.2
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    • pp.79-85
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    • 2008
  • 본 연구에서는, 세리아($CeO_2$), 실리카($SiO_2$) 및 티타늄($TiO_2$) 나노입자의 유전독성과 생태독성 평가를 위하여 바이오 모니터링에 널리 이용되는 수생생태 감시종인 Daphnia magna를 사용하였다. 합성한 나노입자 세리아와 공업적으로 상용되는 실리카 및 티타늄을 유전독성 및 생태독성평가에 이용하였다. 세리아의 경우, D. magna의 DNA의 파괴가 증가함을 통해 세리아의 유전독성 가능성을 확인할 수 있었으나, 실리카 및 티타늄의 경우에는 두 물질 모두 유전독성 영향이 나타나지 않았다. 실리카는 DNA에는 영향을 미치지 않는 것으로 보이나, 실리카에 노출된 D. magna의 사멸은 증가하는 결과를 보였다. 그러나, 티타늄에 노출된 D. magna에서는 유전독성 및 생태독성 인자의 유의적인 변화를 관찰할 수 없었다. 이상의 전체 결과를 통하여 예상할 수 있는 것은 세리아 나노입자가 D. magna에 유전독성을 일으킬 수 있다는 점이다. 이 결과는 나노입자가 광범위하게 이용되고 있으나 독성 관련 자료가 미약한 현재에 수생태 관련 독성 연구 결과로서 이바지 할 수 있을 것으로 여겨진다.

Characteristics of the NO/$N_2O$ Nitrided Oxide and Reoxidized Nitrided Oxide for NVSM (비휘발성 기억소자를 위한 NO/$N_2O$ 질화산화막과 재산화 질화산화막의 특성에 관한 연구)

  • 이상은;서춘원;서광열
    • Journal of the Korean Vacuum Society
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    • v.10 no.3
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    • pp.328-334
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    • 2001
  • The characteristics of $NO/N_2O$ nitrided oxide and reoxidized nitrided oxide being studied as super thin gate oxide and gate dielectric layers of nonvolatile semiconductor memory(NVSM) was investigated by dynamic secondary ion mass spectrometry(D-SMS), time-of-flight secondary ion mass spectrometry(ToF-SIMS), and x-ray photoelectron spectroscopy (XPS). The specimen was annealed in $NO/N_2O$ ambient after initial oxide process. The result of D-SIMS exhibits that the center of nitrogen exists at the initial oxide interface and the distribution of nitrogen is wider in the annealing process with $N_2O$ than with NO annealing process. For investigating the condition of nitrogen that exists within the nitrided oxide, ToF-SIMS and XPS analysis were carried out. It was shown that the center of nitrogen investigated by D-SIMS was expected the SiON chemical bonds. The nitrogen near the newly formed reoxide/silicon substrate interface was appeared as $Si_2NO$ chemical bonds, and it is agreed with the distribution of SiN and $Si_2NO$ species by ToF-SIMS.

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A Study on the Performance Improvement of Turbo Coded OFDM Systems Considering Frequency Offset (주파수 오프셋을 고려한 Tued OFDM 시스템의 성능 개선에 관한 연구)

  • 이영춘;박기식
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.5
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    • pp.908-915
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    • 2001
  • In this paper, it is analyzed theoretically that the performance degradation, caused by carrier frequency offset, in an OFDM/M-ary PSK system. Then, when Turbo coding is adopted to an OFDM/M-ary PSK system, the degree of performance enhancement is evaluated. Finally, the maximum frequency offset is calculated to satisfy the BER performance required in a Turbo coded OFDM/M-ary PSK system. As results of analysis, it is shown that the more the number of M-ary is, the worse the BER performance is. Moreover, 7dB, 9dB, and 17dB of $E_b/N_o$ are required in QPSK, 8PSK and 16PSK systems, respectively in order to satisfy the error performance, $BER=10^{-3}$ for voice communication. If $E_b/N_o$ are 10㏈ and 15㏈, the frequency offset should be below 0.05 and 0.075, respectively, for voice communication. When Turbo coding is adopted to an OFDM/M-ary PSK system, the less the number of M-ary is, the greater the performance enhancement of Turbo coding is. If the number of a M-ary system of the system is below 16, it is found that required $E_b/N_o$ is about 8dB to satisfy $BER=10^{-5}$ Moreover, in the system the Turbo coding scheme, voice communication is available with greatly low$E_b/N_o$, and 8dB of $E_b/N_o$ is enough for data communication regardless of the permission range of frequency offset.

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Numerical Analysis of Combustion Characteristics in a Liquid Propellant Rocket Engine with Split-triplet Injector Elements (Split-triplet 분사기를 장착한 액체 추진제 로켓엔진의 연소특성 해석)

  • 문윤완;손채훈;김영목
    • Journal of the Korean Society of Propulsion Engineers
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    • v.5 no.3
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    • pp.41-51
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    • 2001
  • Combustion characteristics of a KSR-III liquid rocket engine with split-triplet (F-O-O-F) type injector elements are investigated numerically from the viewpoints of engine performance and combustion flowfield. To evaluate numerical analysis of liquid rocket engine with radial type injector arrangement, 2-D axisymmetric and 3-D calculations are carried out and the prediction of engine performance for design and off-design conditions is in a good agreement with hot-firing tests. According to 2-D axisymmetric and 3-D calculations, the prediction error is 3∼5 % from the standpoint of performance. Numerical results of combustion characteristics calculated through 3-D analysis agree well with hot-firing tests qualitatively at injector plate. Decreasing impinging angle and changing radial type injector arrangement to H type injector arrangement reduce effectively local high-temperature region. Also, it is examined that those affect the performance seriously. In conclusion, it is revealed that both injector arrangement and impinging angle are critical parameters to affect the performance and combustion characteristics of the liquid rocket engine.

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A Study on the Wayfinding Model of Outpatient Department in General Hospital (종합병원 외래진료부 진로인지계획 모형에 관한 연구)

  • Han, Gi-Jeung;Lee, Teuk-Koo
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.13 no.2
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    • pp.27-36
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    • 2007
  • Recently, hospital patients experience anxiety, confusion, and stress about wayfinding as the spacial layout and treatment circulatory system of hospitals have become complicated due to their oversized and complex structure. As part of finding a solution to the problem, this study seeks to examine what are the essential elements of the wayfinding planning of O.P.D. in general hospitals, to develop the model of wayfinding, and to suggest the methods of improving the wayfinding system. The research methods of this study adopted were literature review in wayfinding cognition, plan analysis of ten general hospitals, space analysis of these hospitals through space syntax, analysis of the system of visual-perceptual information through a field study, and analysis of surveys and follow-up surveys conducted to support the results. Based on these results, the proposals for finding decision points, providing the information, and developing a model planning are listed as follows. 1) The comprehensive understanding of O.P.D. spacial layout and the visual-perceptual information system is necessary to find the essential elements of wayfinding. 2) The decision points are found through the full understanding of spacial functions, circulation systems, and facility configuration, considering the spacial layout, the bound of the visual-perceptual information system, and the circulatory system. Furthermore, the information decision points could be confined by space syntax. 3) The checklist and color compound & color codes, developed through the planning of signage system and color system could be applied to the methods of providing the information. 4) The planning of wayfinding system according to the whole process of practices for outpatients was mentioned above. The system of visual-perceptual information developed through the process of this study should be integrated in the spacial layout of the whole O.P.D.

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Effect of Methanol Extract and Kaempferol Glycosides from Armoracia rusticana on the Formation of Lipid Peroxide in Bromobenzene-treated Rats In Vitro (서양고추냉이 추출물과 분리한 Kaempferol 배당체들의 브로모벤젠 처리 흰쥐에서 in Vitro 지질과산화억제효과)

  • Hur, Jong-Moon;Lee, Jong-Ho;Choi, Jong-Won;Hwang, Gi-WUk;Chung, Shin-Kyo;Kim, Moon-Sung;Park, Jong-Cheol
    • Korean Journal of Pharmacognosy
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    • v.29 no.3
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    • pp.231-236
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    • 1998
  • Three flavonoid glycosides have been isolated from the aerial part of Armoracia rusticana P. (Cruciferae) in Korea and identified by means of spectral analysis as $kaempferol-3-O-{\beta}-D-xylofuranoside(l)$, $kaempferol-3-O-{\beta}-D-galactopyranoside(2)$ and $kaempferol-3-O-{\beta}-D-xylofuranosyl(1\rightarrow2)-b{\beta}-D-galactopyranoside(3)$. When 1 mg/ml of the methanol extract from the aerial part of this plant was added, lipid peroxide formation in the bromobenzene-treated rat liver decreased by 64%. Among the components isolated from title plant, compounds 2 and 3 reduced the formation of lipid peroxide by 16% and 39% respectively at the concentration of ${10}^{-1}$ mg/ml.

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