• Title/Summary/Keyword: 2D solid

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STEADY-STATE TEMPERATURE ANALYSIS TO 2D ELASTICITY AND THERMO-ELASTICITY PROBLEMS FOR INHOMOGENEOUS SOLIDS IN HALF-PLANE

  • GHADLE, KIRTIWANT P.;ADHE, ABHIJEET B.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.24 no.1
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    • pp.93-102
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    • 2020
  • The concept of temperature distribution in inhomogeneous semi-infinite solids is examined by making use of direct integration method. The analysis is done on the solution of the in-plane steady state heat conduction problem under certain boundary conditions. The method of direct integration has been employed, which is then reduced to Volterra integral equation of second kind, produces the explicit form analytical solution. Using resolvent- kernel algorithm, the governing equation is solved to get present solution. The temperature distribution obtained and calculated numerically and the relation with distribution of heat flux generated by internal heat source is shown graphically.

Polyketides from a Sponge-Derived Fungus, Aspergillus versicolor

  • Lee, Yoon-Mi;Mansoor, Tayyab A.;Hong, Jong-Ki;Lee, Chong-O;Bae, Kyung-Sook;Jung, Jee-H
    • Natural Product Sciences
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    • v.13 no.1
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    • pp.90-96
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    • 2007
  • Bioactivity guided fractionation of the cultured filtrates of Aspergillus versicolor, which was derived from a marine sponge Petrosia sp., yielded three polyketides: decumbenones A (1),B (2), and versiol (3). These compounds were identified on the basis of 1D and 2D NMR spectroscopic and MS analysis. The absolute configuration was defined by the modified Mosher's method. The isolated compounds were tested for cytotoxicity against a panel of five human solid tumor cell lines and antibacterial activity against twenty clinically isolated methicillin-resistant strains. This is the first report on the isolation of these compounds from a marine source.

An Integrated Translation of Nuclear Power Plant Design Data ftom Specification-driven Plant Design Systems to a Neutral Product Model (사양 기반 플랜트 설계 시스템에서 생성된 원자력 플랜트 설계 데이터의 중립 모델로의 통합 변환)

  • Mun, Du-Hwan;Yang, Jeong-Sam;Han, Soon-Hung
    • Korean Journal of Computational Design and Engineering
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    • v.14 no.2
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    • pp.96-104
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    • 2009
  • It gradually becomes important to study on how to efficiently integrate and manage plant lifecycle data such as 2D schematic and 3D solid data, logical configuration data, and equipment specifications data. From this point of view, converting plant design data from various systems into neutral data independent from any commercial systems is one of important technologies for the operation and management of plants which usually have a very long period of life. In order to achieve this goal, a neutral model for efficient integration and management of plant data was defined. After schema mapping between one of specification-driven plant design systems and the neutral model was performed, a plant data translator is also implemented according to the mapping result. Finally, by experiments with nuclear power plant design, the feasibility of the translator was demonstrated.

A boundary radial point interpolation method (BRPIM) for 2-D structural analyses

  • Gu, Y.T.;Liu, G.R.
    • Structural Engineering and Mechanics
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    • v.15 no.5
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    • pp.535-550
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    • 2003
  • In this paper, a boundary-type meshfree method, the boundary radial point interpolation method (BRPIM), is presented for solving boundary value problems of two-dimensional solid mechanics. In the BRPIM, the boundary of a problem domain is represented by a set of properly scattered nodes. A technique is proposed to construct shape functions using radial functions as basis functions. The shape functions so formulated are proven to possess both delta function property and partitions of unity property. Boundary conditions can be easily implemented as in the conventional Boundary Element Method (BEM). The Boundary Integral Equation (BIE) for 2-D elastostatics is discretized using the radial basis point interpolation. Some important parameters on the performance of the BRPIM are investigated thoroughly. Validity and efficiency of the present BRPIM are demonstrated through a number of numerical examples.

A computational setting of calcium leaching in concrete and its coupling with continuum damage mechanics

  • Nguyen, V.H.;Nedjar, B.;Torrenti, J.M.
    • Computers and Concrete
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    • v.1 no.2
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    • pp.131-150
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    • 2004
  • We present in this work a coupled phenomenological chemo-mechanical model that represents the degradation of concrete-like materials. The chemical behaviour is described by the nowadays well known simplified calcium leaching approach. And the mechanical damage behaviour is described by a continuum damage model which involves the gradient of the damage quantity. The coupled nonlinear problem at hand is addressed within the context of the finite element method. For the equation governing the calcium dissolution-diffusion part of the problem, special care is taken to treat the highly nonlinear calcium conductivity and solid calcium functions. The algorithmic design is based on a Newton-type iterative scheme where use is made of a recently proposed relaxed linearization procedure. And for the equation governing the damage part of the problem, an augmented Lagrangian formulation is used to take into account the damage irreversibility constraint. Finally, numerical simulations are compared with experimental results on cement paste.

Fluid-Structure Interaction Analysis for Structure in Viscous Flow (점성 유동장에서 운동하는 구조체의 유탄성 해석)

  • Nho, In-Sik;Shin, Sang-Mook
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.2
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    • pp.168-174
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    • 2008
  • To calculate the fluid-structure interaction(FSI) problem rationally, it should be the basic technology to analyse each domain of fluid and structure accurately. In this paper, a new FSI analysis algorithm was introduced using the 3D solid finite element for structural analysis and CFD code based on the HCIB method for viscous flow analysis. The fluid and structural domain were analysed successively and alternatively in time domain. The structural domain was analysed by the Newmark-b direct time integration scheme using the pressure field calculated by the CFD code. The results for example calculation were compared with other research and it was shown that those coincided each other. So we can conclude that the developed algorithm can be applied to the general FSI problems.

Preparation of Ta Powder for Capacitor by SHS Process (자전연소합성법에 의한 콘덴서용 탄탈륨 분말 제조)

  • Lee, Seung Young;Lee, Sang Il;Won, Chang Whan
    • Korean Journal of Metals and Materials
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    • v.47 no.6
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    • pp.338-343
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    • 2009
  • The purpose of this study is to make the tantalum powder for solid electrolyte capacitor with SHS (self-propagating high-temperature synthesis) process. Raw materials for manufacturing Ta powder were used $Ta_{2}O_{5}$, Mg and NaCl. While progressing SHS process, $Ta_{2}O_{5}$ powder was reduced by Mg powder. The combustion temperature and velocity were easily controled by the varying mole ratio of NaCl, Mg and initial reaction pressure. In the case of only using NaCl as an inorganic agent, the shape is unagglomerated and has high surface area. whereas we were given the powder which has good net structure by the addition of excessive Mg as a diluent.

Metabolite Chemical Composition of the Bletilla striata (Thunb.) Reichb. f. Endophyte Penicillium oxalicum

  • Ran Liu;Xuehua Han;Jing Gao;Min Luo;Dale Guo;Guangzhi Wang
    • Mycobiology
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    • v.51 no.3
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    • pp.148-156
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    • 2023
  • Penicillium oxalicum strain can be isolated from the Bletilla striata (Thunb.) Reichb. f. tubers. Its solid-state fermentation products are concentrated by percolation extraction. Separation and purification have been conducted to the ethyl acetate extracts by preparative HPLC. Based on the use of spectrometry, we have determined 17 known compounds, 12,13-dihydroxy-fumitremorgin C (1), pseurotin A (2), tyrosol (3), cyclo-(L-Pro-L-Val) (4), cis-4-hydroxy-8-O-methylmellein (5), uracil (6), cyclo-(L-Pro-L-Ala) (7), 1,2,3,4-tetrahydro-4-hydroxy-4-quinolin carboxylic acid (8), cyclo-(Gly-L-Pro) (9), 2'-deoxyuridine (10), 1-(b-D-ribofuranosyl)thymine (11), cyclo-(L-Val-Gly) (12), 2'-deoxythymidine (13), cyclo-(Gly-D-Phe) (14), cyclo-L-(4-hydroxyprolinyl)-D-leucine (15), cyclo-(L)-4-hydroxy-Pro-(L)-Phe (16), uridine (17). Here, we report compounds 1-3, 5, 7-8, 11-12, 14-17 are first found and isolated from this endophyte.

Thickness-Dependent Properties of Undoped and Mn-doped (001) PMN-29PT [Pb(Mg1/3Nb2/3)O3-29PbTiO3] Single Crystals

  • Oh, Hyun-Taek;Joo, Hyun-Jae;Kim, Moon-Chan;Lee, Ho-Yong
    • Journal of the Korean Ceramic Society
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    • v.55 no.3
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    • pp.290-298
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    • 2018
  • In order to investigate the effect of thickness on the dielectric and piezoelectric properties of (001) PMN-29PT single crystals, three different types of PMN-29PT samples were prepared using the solid-state single crystal growth (SSCG) method: high density crystal [99%], low density crystal [95%], and high density crystal doped with Mn [98.5%]. When their thickness decreased from 0.5 mm to 0.05 mm, their dielectric constant ($K_3{^T}$), piezoelectric constants ($d_{33}$ and $g_{33}$), and electromechanical coupling factor ($k_t$) decreased continuously. However, their dielectric loss (tan ${\delta}$) increased. The addition of Mn to PMN-PT induced an internal bias electric field ($E_I$), increased the coercive electric field ($E_C$), and prevented local depoling. Therefore, Mn-doped PMN-PT crystals show high stability as well as high performance, even in the form of very thin plates (< 0.2 mm), and thus are suitable for application to high frequency composites, medical ultrasound probes, non-destructive testing devices (NDT), and flexible devices.

Magnetoelectric Effect in$CoFe_2O_4-PZT$Composites ($CoFe_2O_4-PZT$ 복합체의 Magnetoelectric 효과)

  • 최임구;권순주;박수현;정윤희
    • Journal of the Korean Magnetics Society
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    • v.7 no.6
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    • pp.285-292
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    • 1997
  • We have studied magnetoelectric effect with cobalt ferrite-Pb(Zr, Ti) $O_3$ composites made by solid state reaction. The maximum magnetoelectric voltage coefficient, $(dE/ dH)_{max}$, increased with longer sintering time and higher volume fraction of the cobalt ferrite. The magnetic field for $(dE/ dH)_{max}$ became lower with increasing the sintering time and decreasing the volume fraction of the cobalt ferrite. The phenomena were explained in terms of grain size change, mechanical coupling efficiency, easiness of magnetization and polarization. We obtained the highest magnetoelectric voltage coefficient of 0.174V/cm-Oe, which is about 30% higher than the best value reported.

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