• Title/Summary/Keyword: Constituent analysis

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A New Charge Analysis Derived From the Results of Semi-Emprical Mo-Lcao Calculation

  • Yilmaz, Hayriye;Ceyhan, Emre Cahit;Guzel, Yahya
    • Journal of the Korean Chemical Society
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    • v.56 no.2
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    • pp.195-200
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    • 2012
  • In this study we present a new approach for computing the partial atomic charge derived from the wavefunctions of molecules. This charge, which we call the "y_charge", was calculated by taking into account the energy level and orbital populations in each molecular orbital (MO). The charge calculations were performed in the software, which was developed by us, developed using the C# programming language. Partial atomic charges cannot be calculated directly from quantum mechanics. According to a partitioning function, the electron density of constituent molecular atoms depends on the electrostatic attraction field of the nucleus. Taking into account the Boltzmann population of each MO as a function of its energy and temperature we obtain a formula of partial charges.

Lateral Buckling Analysis of Open Section Composite Laminated Beam Under End-Moment (단모멘트를 받는 개단면 박벽 복합재 보의 횡좌굴 해석)

  • 김만호;신동구
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2000.04b
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    • pp.51-58
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    • 2000
  • Lateral buckling behavior of laminated composite thin-walled I-section beams subjected to bending moment is investigated by applying the nonlinear anisotropic thin-walled beam theory. The constituent laminated thin-walled elements of I-section are assumed to be symmetrically laminated. The bending, twisting, and warping stiffnesses of the cross section are obtained based on the definitions of these stiffnesses In the thin-walled anisotropic beam theory In numerical examples, singly-symmetric I-beams with specially orthotropic, quasi-isotropic, angle-plys and various boundary conditions are considered. To validate the proposed theoretical approach, present analytical solutions are compared with three dimensional finite element solutions.

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Phytochemical Constituents from the Seeds of Lithospermum erythrorhizon

  • Park, Jun-Yeon;Lee, Sul-Lim;Han, Saem;Kim, Hye-Min;Lee, Jeong-Min;Ahn, Young-Hee;Lee, Sook-Young;Lee, Sang-Hyun
    • Natural Product Sciences
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    • v.15 no.4
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    • pp.181-184
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    • 2009
  • Phytochemical constituents were isolated from the seeds of Lithospermum erythrorhizon through open column chromatography and prep-HPLC. Their structures were identified as ${\beta}$-sitosterol (1), daucosterol (2), luteolin (3), and allantoin (4) on the basis of spectroscopic analysis. Among them, luteolin (3) was isolated for the first time from the plant.

Dynamic Response Analysis of Composite H-type Cross-section Beams (복합재료 H-형 단면 보의 동적응답 해석)

  • Kim, Sung-Kyun;Song, Oh-Seop
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.6
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    • pp.583-592
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    • 2010
  • Equations of motion of thin-walled composite H-type cross-section beams exposed to concentrated harmonic and non-harmonic time-dependent external excitations, incorporating a number of nonclassical effects of transverse shear, primary and secondary warping, and anisotropy of constituent materials are derived. The forced vibration response characteristics of a composite H-type cross-section beam exhibiting the circumferentially asymmetric stiffness(CAS) configuration are exploited in connection with the structural bending-torsion coupling resulting from directional properties of fiber reinforced composite materials.

Analysis of γ-Aminobutyric Acid Content in Fermented Plant Products by HPLC/UV

  • Lee, Dong Gu;Cho, Sunghun;Lee, Jamin;Cho, Seon Haeng;Lee, Sanghyun
    • Journal of Applied Biological Chemistry
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    • v.58 no.4
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    • pp.303-309
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    • 2015
  • ${\gamma}$-Aminobutyric acid (GABA) content in fermented plant products and their main plant materials (aerial part of Acanthopanax sessiliflorus, fruit of Crataegus pinnatifida, and whole plant of Morus alba) was determined by high-performance liquid chromatography. GABA was quantified using a reverse-phase column with a gradient elution program (water:acetonitrile =90:10 to 0:100 for 40 min). UV detection was conducted at 280 nm. GABA content was measured in fermented plant products (15.07 mg/g), aerial part of A. sessiliflorus (4.49 mg/g), fruit of C. pinnatifida (10.59 mg/g), and whole plant of M. alba (2.31 mg/g). The presence of GABA in fermented plant products, including A. sessiliflorus, C. pinnatifida, and M. alba is important in industrial application for health supplements.

Performance Analysis of Topology for Improvement of LAN Performance in Multimedia Service Environment (멀티미디어 환경에서 LAN성능향상을 위한 토폴로지 성능분석)

  • 조병록;임성진;송재철
    • Journal of Internet Computing and Services
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    • v.2 no.5
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    • pp.93-104
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    • 2001
  • In this paper. we analyze networks in accordance with topology which consists of ATM-LAN in order to enhance performance in multimedia environment, We analyze job processing time of Email, FTP and Http server for variance of node in star, ring and mesh topology, We analyze a load factor of Email, FTP and Http server and variance of sending/receiving rate for various topology, We examined that the constituent networks in this paper can minimize load of server in any other topology.

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Influence of material composition on buckling response of FG plates using a simple plate integral model

  • Bakhti, Karima;Sekkal, Mohamed;Adda Bedia, E.A.;Tounsi, Abdelouahed
    • Smart Structures and Systems
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    • v.25 no.4
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    • pp.447-457
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    • 2020
  • In this study, a simple two-dimensional shear deformation model is employed for buckling analysis of functionally graded (FG) plates. The proposed theory has a kinematic with integral terms which considers the influence of shear deformation without using "shear correction factors". The impact of varying material properties and volume fraction of the constituent on buckling response of the FG plate is examined and discussed. The benefit of this theory over other contributions is that a number of variables is reduced. The basic equations that consider the influence of transverse shear stresses are derived from the principle of virtual displacements. The analytical solutions are obtained utilizing the "Navier method". The accuracy of the proposed theory is proved by comparisons with the different solutions found in the literature.

Suppression Effect of Curcuma longa Rhizome-Derived Components against Nitric Oxide Synthase

  • Lee, Hoi-Seon
    • Journal of Applied Biological Chemistry
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    • v.52 no.4
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    • pp.212-215
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    • 2009
  • The inhibitory effects of Curcuma longa rhizome-derived materials against nitric oxide (NO) production were assessed. The inhibitory effect (57%) on NO production was evidenced by the methanol extract of C. longa at $1\;{\mu}g/mL$. In the fractionation of the methanol extract, the ethyl acetate fraction evidenced an inhibitory effect greater than 62.1% at $1\;{\mu}g/mL$. The active constituent was identified as curcumin. Curcumin exerted potent inhibitory effects of 78.7 and 65.7% at concentrations of 1 and $0.5\;{\mu}g/mL$, respectively. Furthermore, the inhibitory effect of ar-turmerone was measured as 31.3 and 15.8% at 1 and $0.5\;{\mu}g/mL$, respectively. The iNOS expression-suppressive effects of curcumin were assessed via western blot analysis. Our results suggest that curcumin and ar-turmerone may prove useful in the development of new types of NO inhibitors.

Conceptual Design of Life-Detecting Experiment for Future Europa Lander Mission

  • Park, Nuri;Yi, Yu
    • Journal of Astronomy and Space Sciences
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    • v.35 no.2
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    • pp.111-117
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    • 2018
  • A previous exo-terrestrial life-detecting experiment, which was conducted on Mars, sought to detect the products of glucose metabolism, the most common biological process on Earth (Viking biological experiment). Today, glucose metabolism is not considered the universal process of life survival. As NASA plans to launch an orbiter mission in the near future (2020s, the Clipper) and ultimately conduct a lander mission on Europa, a detection experiment that can give broader information regarding habitability is highly required. In this study, we designed a life-detecting experiment using a more universal feature of life, the amphipathic molecular membrane, theoretically considering the environment of Europa (waterdominant environment). This designed experiment focuses on finding and profiling hydrophobic cellular membrane-like microstructures. Expected results are given by conceptual data analysis with plausible hypothetical samples.

A Novel Control Strategy for Input-Parallel-Output-Series Inverter System

  • Song, Chun-Wei;Zhao, Rong-Xiang;Lin, Wang-Qing;Zeng, Zheng
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.2
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    • pp.85-90
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    • 2012
  • This paper presents a topology structure and control method for an input-parallel-output-series(IPOS) inverter system which is suitable for high input current, high output voltage, and high power applications. In order to ensure the normal operation of the IPOS inverter system, the control method should achieve input current sharing(ICS) and output voltage sharing(OVS) among constituent modules. Through the analysis in this paper, ICS is automatically achieved as long as OVS is controlled. The IPOS inverter system is controlled by a three-loop control system which is composed of an outer common-output voltage loop, inner current loops and voltage sharing loops. Simulation results show that this control strategy can achieve low total harmonic distortion(THD) in the system output voltage, fast dynamic response, and good output voltage sharing performance.