• Title/Summary/Keyword: Solid Formulation

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Analysis of Stress Concentration Problems Using Moving Least Squares Finite Difference Method(I) : Formulation for Solid Mechanics Problem (이동최소제곱 유한차분법을 이용한 응력집중문제 해석(I) : 고체문제의 정식화)

  • Yoon, Young-Cheol;Kim, Hyo-Jin;Kim, Dong-Jo;Liu, Wing Kam;Belytschko, Ted;Lee, Sang-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.4
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    • pp.493-499
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    • 2007
  • The Taylor expansion expresses a differentiable function and its coefficients provide good approximations for the given function and its derivatives. In this study, m-th order Taylor Polynomial is constructed and the coefficients are computed by the Moving Least Squares method. The coefficients are applied to the governing partial differential equation for solid problems including crack problems. The discrete system of difference equations are set up based on the concept of point collocation. The developed method effectively overcomes the shortcomings of the finite difference method which is dependent of the grid structure and has no approximation function, and the Galerkin-based meshfree method which involves time-consuming integration of weak form and differentiation of the shape function and cumbersome treatment of essential boundary.

Determination of major and minor elements in low and medium level radioactive wastes using closed-vessel microwave acid digestion (밀폐형 극초단파 산분해법을 이용한 중${\cdot}$저준위 방사성폐기물의 성분 원소 분석)

  • Lee Jeong-Jin;Pyo Hyung-Yeal;Jeon Jong-Seon;Lee Chang-Heon;Jee Kwang-Yong;Ji Pyung-Kook
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.2 no.4
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    • pp.231-238
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    • 2004
  • The conditions are obtained for the decomposition of solid radioactive wastes, including ion exchange resin, zeolite, charcoal, and sludge from nuclear power plant. In the process of decomposing the radioactive wastes was used the microwave acid digestion method with mixed acid. The solution after acid digestion by the following method was colorless and transparent. Each solution was analyzed with ICP-AES and AAS and the recovery yield for 5 different elements added into the simulated radioactive wastes were over $94{\%}$. The elemental analysis of destructive low and medium level radioactive wastes by the proposed microwave acid digestion conditions concerning the chemical characteristics of each radioactive waste are expected to be useful basic data for development of optimal glass formulation.

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Effect of the Dried-Medicinal-Herbs Mixing Ratio on the Sensory and Quality Characteristics of Samgyetang for Ginseng Chicken Soup (한약재 재료의 혼합비율에 따른 한방 삼계탕의 기호도와 품질특성)

  • Jeong, Dae-Yun;Hwang, Su Jung;Lee, Sung-Hee;Eun, Jong-Bang
    • Food Science and Preservation
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    • v.19 no.5
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    • pp.696-702
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    • 2012
  • The physiochemical characteristics and sensory properties of the Samgyetang herb to which different dried medicinal herbs were added were investigated to find the best formulation for the product. For the Samgyetang herbal product, Schizandra chinensis, Atractylodes lancea, Glycyrrhiza uralensis, and Zizyphus jujube were used at a fixed ratio in the formulation, and Paeonia lactiflora (PL), Codonopsis lanceolata (CL), and Scutellaria baicalensis (SB) were added, with different amounts. The pH of Samgyetang increased along with the SB amount, and the soluble-solid content increased along with the CL amount. S7, which had the highest SB addition level, had the highest L value, and the b values were the highest in S7, which had the highest SB addition level. In the sensory evaluation, S7, which had the highest amount of SB, had the highest score in flavor, taste, and overall acceptability. In conclusion, the best formulation for Samgyetang would include PL 8 g, CL 4 g, SB 12 g, Schizandra chinensis 6 g, Atractylodes lancea 4 g, Glycyrrhiza uralensis 2 g, and Zizyphus jujube 4 g.

A Large Slipping Finite Element Model for Geosynthetics Interface Modeling

  • Yi, Chang-Tok
    • Geotechnical Engineering
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    • v.12 no.3
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    • pp.35-48
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    • 1996
  • Reinforced soil structures may experience large local movements between soil and reinforcement. The failure modes of a reinforced structure depend on several factors which are governed by deformation and slipping of the reinforcement. In some cases, pulling out of the reinforcement may occur instead of rupturing, The growing use of geosynthetic liner system for storage of solid and liquid wastes has led to a number of slope instability problems where the synthetic liner may undergo a large amount of stretching and slipping as a result of the loading. The conventional finite element model for the soil-reinforcement interface uses a zero thickness joint element with normal and shear stiffnesses and can only accommodate a small amount of deformation. When a large slippage occurs, the model provides an i ncorrect mechanism for deformation. This paper presents a new interface finite element model which is able to simulate a large amount of slippage between soil and reinforcement. The formulation of the model is presented and the capability of the model is demonstrated using illustrative examples.

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Implementation of Terrain Model Viewer by DirectX (DirectX에 의한 지형 모델 뷰어의 구현)

  • Sohn, Kwang-Hyun;Noh, Yong-Deok
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.9
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    • pp.2403-2411
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    • 1997
  • Direct3D is a recently developed 3D graphic accelerator such that we could make a Windows graphic programs with Direct3D easily. This paper presents the fractal terrain model viewer developed in terms of Direct3D. The object classes and the input dialog box used the model viewer, program initializing process, and the flow of the model viewer are discussed. Finally, the output of terrain formulation in wire-frame, solid, and point type form are presented. To show the results, the data of a terrain model were made by a fractal technique, the midpoint displacement methods with square lattices of points.

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The Stability of Aging and Synthetic Development of Paper Mending Tape for Conservation of Archive Document (종이 기록물 보수용 테이프 점착제 합성 및 열화 안전성 연구)

  • Shin, Joung-Soon;Lee, Kwi-Bok
    • Journal of the Korean Graphic Arts Communication Society
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    • v.30 no.1
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    • pp.35-45
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    • 2012
  • Polyacrylate dispersion(emulsion) as adhesive material was superior in quality such as preservation characteristics and reversibility. The tapes for repairing archival documents manufactured with four different types of formulation resulted in pH 7~8.8, soluble solid 50~52%, and viscosity 1,300~2,500 cps. Sample 4 of those was most excellent. Probably, sample 4 included inorganic materials such as MgO, silica gel, and zeolite. For selecting carrier of tape, tracing papers, were applied for manufacturing tapes and tested for adhesive strength and peel strength. Adhesive strength of tracing papers, was 3.1~3.8(N/10mm), 2.2~2.8(N/10mm), and 1.7-2.3(N/10mm), respectively. Peel strength was similar in all samples. To determine characteristic of conservation to the selected carriers, stability of deterioration was examined at conditions of $105^{\circ}C$ and $80^{\circ}C$ 65% for 7 days.

A local-global scheme for tracking crack path in three-dimensional solids

  • Manzoli, O.L.;Claro, G.K.S.;Rodrigues, E.A.;Lopes, J.A. Jr.
    • Computers and Concrete
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    • v.12 no.3
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    • pp.261-283
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    • 2013
  • This paper aims to contribute to the three-dimensional generalization of numerical prediction of crack propagation through the formulation of finite elements with embedded discontinuities. The analysis of crack propagation in two-dimensional problems yields lines of discontinuity that can be tracked in a relatively simple way through the sequential construction of straight line segments oriented according to the direction of failure within each finite element in the solid. In three-dimensional analysis, the construction of the discontinuity path is more complex because it requires the creation of plane surfaces within each element, which must be continuous between the elements. In the method proposed by Chaves (2003) the crack is determined by solving a problem analogous to the heat conduction problem, established from local failure orientations, based on the stress state of the mechanical problem. To minimize the computational effort, in this paper a new strategy is proposed whereby the analysis for tracking the discontinuity path is restricted to the domain formed by some elements near the crack surface that develops along the loading process. The proposed methodology is validated by performing three-dimensional analyses of basic problems of experimental fractures and comparing their results with those reported in the literature.

On the Numerical Procedure for Estimating Structural Stress of Welded Structures (수치해석을 통한 용접구조물의 구조응력 추정에 관한 연구)

  • Kang, Sung-Won;Kim, Myung-Hyun
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.4 s.142
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    • pp.388-395
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    • 2005
  • A numerical procedure is proposed as a mesh-size insensitive structural stress definition that gives a stress state at a weld toe with relatively large mesh size. The structural stress values obtained using different finite element types, i.e. shell element and solid element, are examined for typical weld structures. The calculation procedures are performed using the balanced nodal forces and moments obtained from finite element solutions. A consistent formulation based on work equivalent argument has been implemented to transform the balanced nodal forces and moments from shell to line force and line moments at each nodal position. The mesh-insensitivity, the effect of distance $\delta$(where the stress is calculated) and the potential limitations of the structural stress method are examined for various types of weldments. Based on the results from this study, it is expected to develop a more precise stress estimation technique for fatigue strength assessment of welded structures.

Formulation and Sensory Evaluation of Granule and Tablet from Lotus Rhizome(Nelumbo nucifera Rhizome)

  • Karki, Rajendra;Bang, Kyu-Ho;Kim, Dong-Wook
    • Korean Journal of Plant Resources
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    • v.21 no.1
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    • pp.103-109
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    • 2008
  • Nelumbo nucifera root(NNR) is used to clear summerheat(暑熱), bear Yang(陽) upwards and stop bleeding as mentioned in traditional Korean medicine. Also, it has been known that NNR is effective for lowering blood pressure and hyperlipidemia. The rhizome is considered to be nutritive, demulcent, diuretic and cholagogue and is used to treat piles, dyspepsia and diarrhea. An increasingly growing market for nutraceuticals and functional foods has triggered the study on natural sources for nutraceuticals, health foods and functional foods. But rhizome was inconvenient to formulate liquid dosage form(extract) by way of hot water because of its limited storage. Also the majority of the consumers have a complaint against the dosage. The purpose of this study was to develop the functional materials from NNR without side effects. We formulated the solid dosage form viz tablet and granule from the lotus root. Sensory evaluation was performed in terms of smell, taste, color and overall of lotus root and all colored forms(brown, dark brown, light green and yellow) of tablet and granule to evaluate the acceptability of the formulated tablets and granules. In sensory evaluation, among the formulated tablets and granules, light green granules obtained best score overall and yellow tablets showed the overall improved acceptability. In conclusion, lotus rhizome could be recommended as functional food. Further studies to clarify bioactive functions of Nelumbo nucifera in experimental animal model on atopic dermatitis are in progress.

Deformation characteristics of spherical bubble collapse in Newtonian fluids near the wall using the Finite Element Method with ALE formulation

  • Kim See-Jo;Lim Kyung-Hun;Kim Chong-Youp
    • Korea-Australia Rheology Journal
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    • v.18 no.2
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    • pp.109-118
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    • 2006
  • A finite-element method was employed to analyze axisymmetric unsteady motion of a deformable bubble near the wall. In the present study a deformable bubble in a Newtonian medium near the wall was considered. In solving the governing equations a structured mesh generator was used to describe the collapse of highly deformed bubbles with the Arbitrary Lagrangian Eulerian (ALE) method being employed in order to capture the transient bubble boundary effectively. In order to check the accuracy of the present FE analysis we compared the results of our FE solutions with the result of the collapse of spherical bubbles in a large body of fluid in which solutions can be obtained using a 1D FE analysis. It has been found that 1D and 2D bubble deformations are in good agreement for spherically symmetric problems confirming the validity of the numerical code. Non-spherically symmetric problems were also solved for the collapse of bubble located near a plane solid wall. We have shown that a microjet develops at the bubble boundary away from the wall as already observed experimentally. We have discussed the effect of Reynolds number and distance of the bubble center from the wall on the transient collapse pattern of bubble.