• Title/Summary/Keyword: Domain interaction

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Development of internal inflow/outflow steady mean flow boundary condition using Perfectly Matched Layer for the prediction of turbulence-cascade interaction noise (난류-캐스케이드 상호작용 소음 예측을 위한 Perfectly Matched Layer 을 이용한 내부 입/출구 정상유동 경계조건의 개발)

  • Kim, Dae-Hwan;Cheong, Cheol-Ung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2012.04a
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    • pp.521-526
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    • 2012
  • It is essential for the accurate time-domain prediction of broadband noise due to turbulence-cascade interaction to develop inflow/outflow boundary conditions to satisfy the following three requirements: to maintain the back ground mean flow, to nonreflect the outgoing disturbances and to generate the specified input gust. The preceding study(1) showed that Perfectly Matched Layer (PML) boundary condition was successfully applied to absorb the outgoing disturbances and to generate the specified gust in the time-domain computations of broadband noise due to interaction of incident gust with a cascade of flat-plates. In present study, PML boundary condition is extended in order to predict steady mean flow that is needed for the computation of noise due to interaction of incident gust with a cascade of airfoils. PML boundary condition is originally designed to absorb flow disturbances superimposed on the steady meanflow in the buffer zone. However, the steady meanflow must be computed before PML boundary condition is applied on the flow computation. In the present paper, PML equations are extended by introducing source term to maintain desired mean flow conditions. The extended boundary condition is applied to the benchmark problem where the meanflow around a cascade of airfoils is predicted. These illustrative computations reveal that the extended PML equations can effectively provide and maintain the target meanflow.

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Development of Internal Inflow/outflow Steady Mean Flow Boundary Condition Using Perfectly Matched Layer for the Prediction of Turbulence-cascade Interaction Noise (난류-캐스케이드 상호작용 소음 예측을 위한 Perfectly Matched Layer을 이용한 내부 입/출구 정상유동 경계조건의 개발)

  • Kim, Dae-Hwan;Cheong, Cheol-Ung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.7
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    • pp.685-691
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    • 2012
  • It is essential for the accurate time-domain prediction of broadband noise due to turbulence-cascade interaction to develop inflow/outflow boundary conditions to satisfy the following three requirements: to maintain the back ground mean flow, to nonreflect the outgoing disturbances and to generate the specified input gust. The preceding study showed that perfectly matched layer(PML) boundary condition was successfully applied to absorb the outgoing disturbances and to generate the specified gust in the time-domain computations of broadband noise due to interaction of incident gust with a cascade of flat-plates. In present study, PML boundary condition is extended in order to predict steady mean flow that is needed for the computation of noise due to interaction of incident gust with a cascade of airfoils. PML boundary condition is originally designed to absorb flow disturbances superimposed on the steady meanflow in the buffer zone. However, the steady meanflow must be computed before PML boundary condition is applied on the flow computation. In the present paper, PML equations are extended by introducing source term to maintain desired mean flow conditions. The extended boundary condition is applied to the benchmark problem where the meanflow around a cascade of airfoils is predicted. These illustrative computations reveal that the extended PML equations can effectively provide and maintain the target meanflow.

Nonlinear Soil-Structure Interaction Analysis of a Seismically Isolated Nuclear Power Plant Structure using the Boundary Reaction Method (경계반력법을 이용한 지진격리 원전구조물의 비선형 지반-구조물 상호작용 해석)

  • Lee, Eun-Haeng;Kim, Jae-Min;Lee, Sang-Hoon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.19 no.1
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    • pp.37-43
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    • 2015
  • This paper presents a detailed procedure for a nonlinear soil-structure interaction of a seismically isolated NPP(Nuclear Power Plant) structure using the boundary reaction method (BRM). The BRM offers a two-step method as follows: (1) the calculation of boundary reaction forces in the frequency domain on an interface of linear and nonlinear regions, (2) solving the wave radiation problem subjected to the boundary reaction forces in the time domain. For the purpose of calculating the boundary reaction forces at the base of the isolator, the KIESSI-3D program is employed in this study to solve soil-foundation interaction problem subjected to vertically incident seismic waves. Wave radiation analysis is also employed, in which the nonlinear structure and the linear soil region are modeled by finite elements and energy absorbing elements on the outer model boundary using a general purpose nonlinear FE program. In this study, the MIDAS/Civil program is employed for modeling the wave radiation problem. In order to absorb the outgoing elastic waves to the unbounded soil region, spring and viscous-damper elements are used at the outer FE boundary. The BRM technique utilizing KIESSI-3D and MIDAS/Civil programs is verified using a linear soil-structure analysis problem. Finally the method is applied to nonlinear seismic analysis of a base-isolated NPP structure. The results show that BRM can effectively be applied to nonlinear soil-structure interaction problems.

Infinite Boundary Elements for Soil-Structure Interaction Analysis in Time Domain (지반-구조물 상호작용의 시간영역 해석을 위한 무한경계요소)

  • 윤정방;최준성
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1994.04a
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    • pp.137-144
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    • 1994
  • In this study, a new procedure for solving 2-D dynamic problems of semi-infinite medium in time domain by boundary element method (BEM) is presented. Efficient modelling of the far field region, infinite boundary elements are introduced. The shape function of the infinite boundary element is a combination of decay functions and Laguerre functions. Though the present shape functions have been developed for the time domain analysis, they may be also applicable to the frequency domain analysis. Through the response analysis in a 2-D half space under a uniformly distributed dynamic load, it has been found that an excellent accuracy can be achieved compared with the analytical solution

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An analysis of the arm-type site binding domain of bacteriophage .lambda. integrase

  • Cho, Eun-Hee
    • Journal of Microbiology
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    • v.33 no.2
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    • pp.165-170
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    • 1995
  • The 356 amino acid long lambda integrase protein of bacteriophage .lambda. constains two autonomous DNA binding domains with distinct sequence specificities. The amino terminal domain of integrase is implicated to bind to the arm-type sequences and the carboxyl domain interacts with the coretype sequencess. As a first step to understand the molecular mechanism of the integrase-DNA interaction at the arm-type site, the int(am)94 gene carrying an amber mutation at the 94th codon of the int was cloned under the control of the P$\_$tac/ promoter and the lacI$\_$q/ gene. The Int(am)94 mutant protein of amino terminal 93 amino acid residues can be produced at high level from a suppressor free strain harboring the plasmid pInt(am)94. The arm-type binding activity of Int(am)94 were measured in vivo and in vitro. A comparison of the arm-type binding properties of the wild-type integrase and the truncated Int(am)94 mutant indicated that the truncated fragment containing 93 amino acid residues carry all the determinants for DNA binding at the arm-type sites.

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Multiscale simulation based on kriging based finite element method

  • Sommanawat, Wichain;Kanok-Nukulchai, Worsak
    • Interaction and multiscale mechanics
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    • v.2 no.4
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    • pp.353-374
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    • 2009
  • A new seamless multiscale simulation was developed for coupling the continuum model with its molecular dynamics. Kriging-based Finite Element Method (K-FEM) is employed to model the continuum base of the entire domain, while the molecular dynamics (MD) is confined in a localized domain of interest. In the coupling zone, where the MD domain overlaps the continuum model, the overall Hamiltonian is postulated by contributions from the continuum and the molecular overlays, based on a quartic spline scaling parameter. The displacement compatibility in this coupling zone is then enforced by the Lagrange multiplier technique. A multiple-time-step velocity Verlet algorithm is adopted for its time integration. The validation of the present method is reported through numerical tests of one dimensional atomic lattice. The results reveal that at the continuum/MD interface, the commonly reported spurious waves in the literature are effectively eliminated in this study. In addition, the smoothness of the transition from MD to the continuum can be significantly improved by either increasing the size of the coupling zone or expanding the nodal domain of influence associated with K-FEM.

Coexpression and protein-protein complexing of DIX domains of human Dvl1 and Axin1 protein

  • Choi, Seung-Hye;Choi, Kyung-Mi;Ahn, Hyung-Jun
    • BMB Reports
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    • v.43 no.9
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    • pp.609-613
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    • 2010
  • The Dvl and Axin proteins, which are involved in the Wnt signaling pathway, each contain a conserved DIX domain in their sequences. The DIX domain mediates interaction between Dvl and Axin, which together play an important role in signal transduction. However, the extremely low production of DIX domain fragments in E. coli has prevented more widespread functional and structural studies. In this study, we demonstrate that the DIX domains of Dvl and Axin are expressed noticeably in a multi-cistronic system but not in a mono-cistronic system. Formation of the $DIX_{Dvl1}-DIX_{Axin1}$ complex was investigated by affinity chromatography, SEC and crystallization studies. Unstable DIX domains were stabilized by complexing with counterpart DIX domains. The results of the preliminary crystallization and diffraction of the $DIX_{Dvl1}-DIX_{Axin1}$ complex may prove useful for further crystallographic studies.

Pleckstrin homology domain of phospholipase D2 is a negative regulator of focal adhesion kinase

  • Kim, Mi Kyoung;Hwang, Won Chan;Min, Do Sik
    • BMB Reports
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    • v.54 no.2
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    • pp.112-117
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    • 2021
  • Phospholipase D2 (PLD2) has been implicated in the tyrosine kinase-mediated signaling pathways, but the regulation events are yet to be identified. Herein, we demonstrate that pleckstrin homology (PH) domain of PLD2 (PLD2-PH) exerts an antitumorigenic effect via the suppression of PLD2 and focal adhesion kinase (FAK). The kinase domain of FAK interacts with PLD2-PH and induces tyrosine phosphorylation and activation of PLD2. Furthermore, PLD2 increased tyrosine phosphorylation of FAK. However, ectopic expression of the PLD2-PH competes for binding to FAK and reduces the interaction between PLD2 and FAK, thereby suppressing FAK-induced PLD activation and tyrosine phosphorylation of FAK. The PLD2-PH suppressed the migration and invasion of glioblastoma cells, as well as tumor formation in a xenograft mouse model. This study uncovers a novel role of PLD2-PH as a negative regulator of PLD2 and FAK.