• Title/Summary/Keyword: Mechanism of C.Z.M

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The Characteristics of Foreign and Domestic C.Z.M Cases (국내외 연안구역관리(C.Z.M)의 특성 비교)

  • Oh, Ji-Hoon;Lee, Seok-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.7
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    • pp.2693-2701
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    • 2010
  • Coastal Zone is a integrated space including both coastal waters and inland. C.Z.M is a strategic practice system which can integrate and coordinate the coastal zone for preserving and making use of coastal resources. Through foreign and domestic C.Z.M Cases, this study analyzes the operating mechanism in the three aspects: role sharing among the administrative agencies, mediation and cooperation among the interested parties, and inducements of voluntary participation. And it achieves the common characteristics of C.Z.M: building the assessment system for establishing desirable policy directions, the stable support system for sustainable coastal management, the mediation system for cooperation of stakeholder, and the education system for reinforcing the management ability and inducing the voluntary participation. Finally it suggests the implications to build the coastal zone management system properly on the basis of common values in this mechanism.

A Study on Hot Deformation Behavior of $SiC_p$/AI2024 Composites Reinforced with Different Sizes of $SiC_p$ ($SiC_p$ 크기를 달리한 $SiC_p$/Al2024 복합재료의 열간 변형특성에 관한연구)

  • Ko, Byung-Chul;Hong, Heung-Ki;Yoo, Yeon-Chul
    • Transactions of Materials Processing
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    • v.7 no.2
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    • pp.158-167
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    • 1998
  • Hot restoration mechanism flow stress and stain of the Al2024 composites reinforced with 1,8,15,36, and $44{\mu}m\;SiC_p$(10 vol. %) were studied by hot torsion tests. The hot restoration mechanism of all the composites was found to be dynamic recrystallization(DRX) at $320^{\circ}C$ while that of the composites reinforced with 1 and $8{\mu}m\;SiC_p$ was found to be dynamic recovery(DRX) at $480^{\circ}C$. It was found that the Al2024 composite with $15{\mu}m\;SiC_p$ showed the highest flow stress(${\sim}$223 MPa) at $320^{\circ}C$ under a strain rate of 1.0/sec. Also the highest flow strain of the composites was obtained at $430^{\circ}C$. The com-posites reinforced with 1 and $8{\mu}m\;SiC_p$ showed lower flow stress and higher flow strain at $480^{\circ}C$ than those of the composites reinforced with 15, 36, and $44\;{\mu}m\;SiC_p$ These result were discussed in relation to the transition of the hot restoration mechanism. $DRX{\leftrightarrow}DRV$. The dependence of flow stress on strain rate and temperature was attempted to fit with the hyperbolic sine equation ($\dot{\varepsilon}=A[sinh({\alpha}{\cdot}{\sigma}_p]^n$ exp(-Q/RT)and Zener-Hollomon parameter($Z=\;\dot{\varepsilon}\;exp(Q/RT))$.

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Experiment of the Precision micro-positioning stage (초정밀 마이크로 위치결정 스테이지의 제작 및 평가)

  • Han, C. S.;Paek, S.;No, M. K.;Lee, C. H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.244-247
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    • 2002
  • The performance of the precision micro-positioning 4-dof stage is presented. The compact design utilizes the monolithic mechanism to achieve the translation in the Z axis and rotation in the $\theta$ z, $\theta$ x and $\theta$ y axes with high stiffness and high damping. Hysteresis, nonlinearity, and drift of the piezoelectric effects are improved by incorporating the sensors in a feedback control. Experiments demonstrate that the micro-positioning stage is capable of 2nm resolution over the travel range of 25$\mu\textrm$ m in the Z axis, 0.0l7 $\mu\textrm$ rad resolution over the 170$\mu\textrm$ rad in the $\theta$ z and 0.011 $\mu\textrm$ rad resolution over the $\mu\textrm$ rad in the $\theta$ x and $\theta$ y axes. The cross-axis interferences among the axes are at a noise range. This stage is available for positioning error compensation of the XY stage with large stroke.

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Insecticidal Activation Mechanism of m-Methylphenyl N-methylcarbamate Derivatives (m-Methylphenyl N-methylcarbamate 유도체들의 살충활성 메카니즘)

  • Park, Seung-Heui;Nam, Sang-Kil;Sung, Nack-Do
    • Korean Journal of Agricultural Science
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    • v.22 no.2
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    • pp.127-133
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    • 1995
  • A Series of meta and para-substituted phenyl N-methylcarbamate derivatives were synthesized and influence of substituents(X) on the molecular orbital(MO) quantities of carbonyl group, carbamylation reaction center, and insecticidal activities($pI_50$) were discussed quantitatively. From these findings, the most stable streo conformer(Z) shows that the planer phenyl group occupies vertical(${\theta}=90^{\circ}$) position on the plane of the N-methylcarbamyl group. The carbamylation mechanism was proposed that the carbamylation process of acetylcholinesterase(ACh.E) by m-methyl substituted phenyl N-methylcarbamate derivatives proceeds via hyperconjugation of m-methyl group and carbonyl oxygene protonation, theromodynamically control reaction with acidic site of ACh.E.

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Mechanism on the Hydrolysis of Cinnamonitrile in Strong Acid (强酸性 溶液中에서 Cinnamonitrile의 加水分解 反應메카니즘)

  • Ki-Sung Kwon;Nack-Do Sung;Tae-Rin Kim;Jeon, Yong Gu
    • Journal of the Korean Chemical Society
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    • v.28 no.6
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    • pp.418-424
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    • 1984
  • Rate constants for the hydrolysis of cinnamonitrile in the concentration range of 1 ∼ 5M of perchloric acid at 25$^{\circ}$C have been determined by UV spectrophotometry and from the Bunnett equations, hydration parameters (${\omega}$ = 9.8, ${\omega}^*$ = 0.42 & ${\phi}$=1.6) were obtained. CNDO/2 MO calculations were performed to determine relative stability, net charges, and overlap population of various conformational isomers. The results show that the (E)-planar is more stable than the (Z)-planar and protonation is favored on the nitrogen atom. On the basis of above findings, the acid hydrolysis is initiated by the protonation of the nitrogen atom of cinnamonitrile and then water molecule acting as nucleophile and as a proton transfer agent in the rate determining step. In the transition state of the acid hydrolysis, nucleophilic addition of water molecule occurs by sigma approach to the positively charged $C_7({\alpha}$) atom of the conjugate acid. As the results, we may conclude that the hydrolysis of cinnamonitrile in the strong acidic media proceeds through the A-2 type mechanism.

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Structure-Reactivity Relationships for the Reaction of Aryl Benzoates with Amines (Aryl Benzoates와 Amine류의 반응에 관한 구조-반응성 관계)

  • Cheong, Duk-Young;Kweon, Jeong-Min;Yoh, Soo-Dong;Park, Byung-Soo
    • Journal of the Korean Chemical Society
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    • v.39 no.7
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    • pp.572-577
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    • 1995
  • The reaction rates of aryl substituted(Z)-benzoates with amines were determined by a spectro-photometric method in acetonitrile at various temperatures. Hammett $\rho$, Bronsted ${\beta}$ values, and activation parameters were evaluated from the kinetic data. Linear free energy relationships, activation parameters, and the interpretation of M-O-F-J diagram suggested that these reactions were probably enforced an $S_AN$ mechanism.

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HIGH-RESOLUTION NEAR-INFRARED SPECTRA OF NEARBY QUASARS

  • Le, Huynh Anh Nguyen;Pak, Soojong;Im, Myungshin;Ho, LuisC.
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.91-91
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    • 2012
  • We present high-resolution near-infrared host galaxy spectra of low-z quasars, PG0844+349 (z=0.064), PG1226+023 (z=0.158), and PG1426+015 (z=0.086). The observation was done by using the near-IR high resolution echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. The full width at half maximum of the point spread function was about 0.3 arcsec by using an Adaptive Optics system, which can effectively resolve the quasar spectra from the host galaxy spectra. The signal-to-noise ratios are increased by the total exposure time up to several hours per targets and the development of data reduction method. We compare our results to the stellar spectra library and sample spectra from Dasyra et al. (2007) and Watson et al. (2008). The identified spectral lines will be used to study the physical mechanism of quasars, and the velocity dispersions of the stars in the bulge of the host galaxy.

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Crystallization of a-Si Induced by Ni-Si oxide source

  • Meng, Z.;Liu, Z.;Zhao, S.;Wu, C.;Wong, M.;Kwok, H.;Xiong, S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.985-988
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    • 2008
  • Metal induced crystallization of a-Si with a source of Ni/Si oxide was studied. Its mechanism to induce crystallization was discussed. It was found that new source behaves an effect of self-released nickel and reducing nickel residua, so can provide a wider process tolerance; improve the uniformity and stability of TFTs.

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HIGH RESOLUTION NEAR-INFRARED SPECTRA OF NEARBY QUASAR, PG1426+015

  • Le, Huynh Anh Nguyen;Pak, Soo-Jong;Im, Myung-Shin;Ho, Luis C.
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.51.1-51.1
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    • 2012
  • We observed low-z quasar PG1426+015 (z=0.086), using the near-IR high resolution echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. Using an Adoptive Optics system, the full width at half maximum of the point spread function was about 0.3 arcsec, which can effectively separate the quasar spectra from the host galaxy spectra. We also maximize the total exposure time up to several hours per target, and develop data reduction methods to increase the signal-to-noise ratios. This poster presents the data reduction processes and sample spectra from the quasar and its host galaxy. These spectral lines will be used to study the physical mechanism of quasars, and the velocity dispersions of the stars in the bugle of the host galaxy.

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The Evolution of Dynamically Recrystallized Microstructure for SCM 440 (SCM 440 강재의 동적 재결정 조직 변화에 관한 연구)

  • 한형기;유연철
    • Transactions of Materials Processing
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    • v.10 no.1
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    • pp.35-41
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    • 2001
  • The high temperature deformation behavior of SCM 440 can be characterized by the hot torsion test in the temperature ranges of $900^{\circ}C$~$1100^{\circ}C$ and strain rate ranges of 0.05/sec~5/sec. The aim of this paper is to establish the quantitative equation of the volume fraction of dynamic recrystallization (DRX) as a function of processing variables, such as strain rate ($\varepsilon$), temperature (T), and strain ('$\varepsilon$). During hot deformation, the evolution of microstructure could be analyzed from work hardening rate ($\theta$). For the exact prediction of dynamic softening mechanism the critical strain ($\varepsilon_c$), the strain for maximum softening rate ($\varepsilon^*$ and Avrami' exponent (m') were quantitatively expressed by dimensionless parameter, Z/A, respectively. The transformation-effective strain-temperature curve for DRX could be composed. It was found that the calculated results were agreed with the experimental data for the steel at any deformation conditions.

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