• 제목/요약/키워드: molecular modeling

검색결과 415건 처리시간 0.026초

Molecular dynamics simulation of bulk silicon under strain

  • Zhao, H.;Aluru, N.R.
    • Interaction and multiscale mechanics
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    • 제1권2호
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    • pp.303-315
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    • 2008
  • In this paper, thermodynamical properties of crystalline silicon under strain are calculated using classical molecular dynamics (MD) simulations based on the Tersoff interatomic potential. The Helmholtz free energy of the silicon crystal under strain is calculated by using the ensemble method developed by Frenkel and Ladd (1984). To account for quantum corrections under strain in the classical MD simulations, we propose an approach where the quantum corrections to the internal energy and the Helmholtz free energy are obtained by using the corresponding energy deviation between the classical and quantum harmonic oscillators. We calculate the variation of thermodynamic properties with temperature and strain and compare them with results obtained by using the quasi-harmonic model in the reciprocal space.

Electrochemical Studies on Heptamethine Cyanine Dyes

  • Kim, Young-Sung;Shin, Jong-Il;Park, Soo-Youl;Jun, Kun;Son, Young-A
    • 한국염색가공학회지
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    • 제21권5호
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    • pp.35-40
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    • 2009
  • Computational calculations of molecular orbital and electrochemical redox/oxidation potentials are of very importance to determine the compound properties. The energy levels of molecular orbital were calculated by the density function theory (DFT) with exchange correction functional of local density approximation (LSA) based on the Perdew-Wang (PWC) setting and cyclic voltammetry.

Atomic and Molecular Data Research for Plasma Applications

  • 윤정식;권득철;송미영;장원석;황성하;박준형
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.32-32
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    • 2010
  • Since the characteristics of plasmas depend strongly on the interactions between plasma particles such as electron, ions, and neutrals, a well-established atomic and molecular database is needed to understand and produce various types of plasma. Thus, National Fusion Research Institute (NFRI) started to establish the plasma property DB for fusion and industrial plasma from last 2002. Here we describe our recent data evaluation activities regarding to production of atomic and molecular data that are needed for modeling plasma in fusion tokamaks and also low temperature industrial plasmas.

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Hologram Quantitative Structure Activity Relationship (HQSAR) Study of Mutagen X

  • Cho, Seung-Joo
    • Bulletin of the Korean Chemical Society
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    • 제26권1호
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    • pp.85-90
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    • 2005
  • MX and its analogs are synthesized and modeled by quantitative structure activity relationship (QSAR) study including comparative molecular field analysis (CoMFA). As a result, factors affecting this class of compounds have been found to be steric and electrostatic effects. Because hologram quantitative structure activity relationship (HQSAR) technique is based on the 2-dimensional descriptors, this is free of ambiguity of conformational selection and molecular alignment. In this study we tried to include all the data available from the literature, and modeled with the HQSAR technique. Among the parameters affecting fragmentation, connectivity was the most important one for the whole compounds, giving good statistics. Considering additional parameters such as bond specification only slightly improved the model. Therefore connectivity has been found to be the most appropriate to explain the mutagenicity for this class of compounds.

Modeling of Liquid-Vapor Interfaces of Condensation Flows Based on Molecular Dynamics Simulations

  • Kannan, Hiroki;Teramoto, Susumu;Nagashima, Toshio
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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    • pp.418-425
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    • 2004
  • Characteristics of a liquid-vapor interface where a nonequilibrium condensation flow exists are considered based on molecular dynamics simulations, The condensation coefficient, the velocity distributions of the reflected and evaporated molecules and the number flux of the evaporated molecules are compared with those under the liquid-vapor equilibrium. The comparison shows that the condensation coefficient under the nonequilibrium condensation is slightly larger and the number flux of the evaporated molecules is considerably smaller than those under the liquid-vapor equilibrium. The net condensation flux under the nonequilibrium condensation is underestimated if it is evaluated from the condensation coefficient and the number flux of the evaporated molecules under the liquid-vapor equilibrium. However the underestimation is relatively small.

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Docking Study of Corticotropin-Releasing Factor-1 Receptor with Its Antagonists

  • Babu, Sathya
    • 통합자연과학논문집
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    • 제11권1호
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    • pp.19-24
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    • 2018
  • CRFR is involved in the pathophysiology of various disorders including depression, stress, anxiety, post-traumatic stress disorder, and addiction. The discovery of novel and structurally diverse CRF1 receptor inhibitors becomes essential. In this study, we have performed molecular docking of CRF1R with the derivatives of 8-substituted-2-aryl-5-alkylaminoquinolines as CRF1R inhibitors. The antagonist molecules were optimized and docked into the binding site of the receptor. On analysing the docked complexes we have identified that the residues HIS214, THR215, ARG227, ARG1008, LYS1060 and ASP1061 are important in forming hydrogen bond with the inhibitors. Further studies on these residues could reveal important structural features required for the formation of CRF1R-inhibitor complex and thus in the discovery of novel and potent inhibitors.

Molecular modeling of COX-2 inhibitors: 3D-QSAR and docking studies

  • Kim, Hye-Jung;Chae, Chong-Hak;Yoo, Sung-Eun;Yi, Kyu-Yang;Park, Kyung-Lae
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.65.2-65.2
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    • 2003
  • 88 selective COX-2 inhibitors belonging to three chemical classes (triaryl rings, diaryl cycloalkanopyrazoles, and diphenyl hydrazides) were studied using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). Partial least squares analysis produced statistically significant models with q values of 0.84 and 0.79 for CoMFA and CoMSIA, respectively. The key spatial properties were detected by careful analysis of the isocontour maps. The binding energies calculated from flexible docking correlated with inhibitory activities by the least-squares fit method. (omitted)

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질소클러스터 이론예측 (A Review of the Theoretical Prediction of Nitrogen Clusters)

  • 이준웅
    • 한국군사과학기술학회지
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    • 제6권3호
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    • pp.86-102
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    • 2003
  • Polynitrogen molecules are of great interest as potential high energy-density materials, and hence such structures of various isomers of nitrogen clusters have been calculated using molecular modeling techniques by the researchers from various sectors of scientific institutions. In this article, the predicted meta-stable structures of these hypothetical molecules have been thoroughly reviewed.