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On nonlinear vibration behavior of piezo-magnetic doubly-curved nanoshells

  • Mirjavadi, Sayed Sajad;Bayani, Hassan;Khoshtinat, Navid;Forsat, Masoud;Barati, Mohammad Reza;Hamouda, A.M.S
    • Smart Structures and Systems
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    • v.26 no.5
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    • pp.631-640
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    • 2020
  • In this paper, nonlinear vibration behaviors of multi-phase Magneto-Electro-Elastic (MEE) doubly-curved nanoshells have been studied employing Jacobi elliptic function method. The doubly-curved nanoshell has been modeled by using nonlocal elasticity and classic shell theory. An exact estimation of nonlinear vibrational behavior of smart doubly-curved nanoshell has been obtained via Jacobi elliptic function method. This method can incorporate the influences of higher order harmonics leading to an exact estimation of nonlinear vibration frequency. It will be indicated that nonlinear vibrational frequency of doubly-curved nanoshell relies on nonlocal effect, material composition, curvature radius, center deflection and electro-magnetic field.

Post-buckling of higher-order stiffened metal foam curved shells with porosity distributions and geometrical imperfection

  • Mirjavadi, Seyed Sajad;Forsat, Masoud;Barati, Mohammad Reza;Hamouda, A.M.S.
    • Steel and Composite Structures
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    • v.35 no.4
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    • pp.567-578
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    • 2020
  • Based on third-order shear deformation shell theory, the present paper investigates post-buckling properties of eccentrically stiffened metal foam curved shells/panels having initial geometric imperfectness. Metal foam is considered as porous material with uniform and non-uniform models. The single-curve porous shell is subjected to in-plane compressive loads leading to post-critical stability in nonlinear regime. Via an analytical trend and employing Airy stress function, the nonlinear governing equations have been solved for calculating the post-buckling loads of stiffened geometrically imperfect metal foam curved shell. New findings display the emphasis of porosity distributions, geometrical imperfectness, foundation factors, stiffeners and geometrical parameters on post-buckling properties of porous curved shells/panels.

Post-buckling analysis of geometrically imperfect nanoparticle reinforced annular sector plates under radial compression

  • Mirjavadi, Seyed Sajad;Forsat, Masoud;Mollaee, Saeed;Barati, Mohammad Reza;Afshari, Behzad Mohasel;Hamouda, A.M.S.
    • Computers and Concrete
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    • v.26 no.1
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    • pp.21-30
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    • 2020
  • Buckling and post-buckling behaviors of geometrically imperfect annular sector plates made from nanoparticle reinforced composites have been investigated. Two types of nanoparticles are considered including graphene oxide powders (GOPs) and silicone oxide (SiO2). Nanoparticles are considered to have uniform and functionally graded distributions within the matrix and the material properties are derived using Halpin-Tsai procedure. Annular sector plate is formulated based upon thin shell theory considering geometric nonlinearity and imperfectness. After solving the governing equations via Galerkin's technique, it is showed that the post-buckling curves of annular sector plates rely on the geometric imperfection, nanoparticle type, amount of nanoparticles, sector inner/outer radius and sector open angle.

Porosity effects on post-buckling behavior of geometrically imperfect metal foam doubly-curved shells with stiffeners

  • Mirjavadi, Seyed Sajad;Forsat, Masoud;Yahya, Yahya Zakariya;Barati, Mohammad Reza;Jayasimha, Anirudh Narasimamurthy;Hamouda, AMS
    • Structural Engineering and Mechanics
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    • v.75 no.6
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    • pp.701-711
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    • 2020
  • This papers studies nonlinear stability and post-buckling behaviors of geometrically imperfect metal foam doubly-curved shells with eccentrically stiffeners resting on elastic foundation. Metal foam is considered as porous material with uniform and non-uniform models. The doubly-curved porous shell is subjected to in-plane compressive loads as well as a transverse pressure leading to post-critical stability in nonlinear regime. The nonlinear governing equations are analytically solved with the help of Airy stress function to obtain the post-buckling load-deflection curves of the geometrically imperfect metal foam doubly-curved shell. Obtained results indicate the significance of porosity distribution, geometrical imperfection, foundation factors, stiffeners and geometrical parameters on post-buckling characteristics of porous doubly-curved shells.

Post-buckling analysis of geometrically imperfect tapered curved micro-panels made of graphene oxide powder reinforced composite

  • Mirjavadi, Seyed Sajad;Forsat, Masoud;Barati, Mohammad Reza;Hamouda, AMS
    • Steel and Composite Structures
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    • v.36 no.1
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    • pp.63-74
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    • 2020
  • The present research investigates post-buckling behavior of geometrically imperfect tapered curved micro-panels made of graphene oxide powder (GOP) reinforced composite. Micro-scale effects on the panel structure have been included based on strain gradient elasticity. Micro-panel is considered to be tapered based on thickness variation along longitudinal direction. Weight fractions of uniformly and linearly distributed GOPs are included in material properties based on Halpin-Tsai homogenization scheme considering. Post-buckling curves have been determined based on both perfect and imperfect micro-panel assumptions. It is found that post-buckling curves are varying with the changes of GOPs weight fraction, geometric imperfection, GOP distribution type, variable thickness parameters, panel curvature radius and strain gradient.

Investigating nonlinear forced vibration behavior of multi-phase nanocomposite annular sector plates using Jacobi elliptic functions

  • Mirjavadi, Seyed Sajad;Forsat, Masoud;Barati, Mohammad Reza;Hamouda, A.M.S.
    • Steel and Composite Structures
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    • v.36 no.1
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    • pp.87-101
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    • 2020
  • A multi-scale epoxy/CNT/fiberglass annular sector plate is studied in this paper in the view of determining nonlinear forced vibration characteristics. A 3D Mori-Tanaka model is employed for evaluating multi-scale material properties. Thus, all of glass fibers are assumed to have uni-direction alignment and CNTs have random diffusion. The geometry of annular sector plate can be described based on the open angle and the value of inner/outer radius. In order to solve governing equations and derive exact forced vibration curves for the multi-scale annular sector, Jacobi elliptic functions are used. Obtained results demonstrate the significance of CNT distribution, geometric nonlinearity, applied force, fiberglass volume, open angle and fiber directions on forced vibration characteristics of multi-scale annular sector plates.

Digenic or oligogenic mutations in presumed monogenic disorders: A review

  • Afif Ben-Mahmoud;Vijay Gupta;Cheol-Hee Kim;Lawrence C Layman;Hyung-Goo Kim
    • Journal of Genetic Medicine
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    • v.20 no.1
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    • pp.15-24
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    • 2023
  • Monogenic disorders are traditionally attributed to the presence of mutations in a single gene. However, recent advancements in genomics have revealed instances where the phenotypic expression of apparently monogenic disorders cannot be fully explained by mutations in a single gene alone. This review article aims to explore the emerging concept of digenic or oligogenic inheritance in seemingly monogenic disorders. We discuss the underlying mechanisms, clinical implications, and the challenges associated with deciphering the contribution of multiple genes in the development and manifestation of such disorders. We present relevant studies and highlight the importance of adopting a broader genetic approach in understanding the complex genetic architecture of these conditions.

A Comparative Study on the Determinants of the GCC Countries' Exports: A Gravity Approach (중력모형을 이용한 걸프협력회의(GCC) 국가들의 무역 결정요인에 관한 비교연구)

  • Bouhamdi, Abdullah A.;Ko, Jong-Hwan
    • International Area Studies Review
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    • v.22 no.2
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    • pp.19-40
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    • 2018
  • This paper aims to quantify the determinants of the Gulf Cooperation Council (GCC) countries' exports by using an augmented gravity model. The gravity model was applied to the six members of the GCC (Kuwait, Saudi Arabia, Bahrain, Qatar, the United Arab Emirates and Oman) with datasets that consist of their major 55 trading partners. The findings of this paper reveal that the product of the exporter's GDP and its trading partner's GDP had a significantly positive effect on the exports of five GCC members, except for Qatar. Distance had a significant and negative effect on the exports of the UAE, Saudi Arabia and Oman, while it had a significantly positive effect on those of Bahrain and Qatar. The exporter's GDP per capita had a significantly positive effect on the exports of Bahrain, the UAE and Oman, while a negative effect on Saudi Arabia's exports. The exporter's population had a significantly positive effect on the exports of all six GCC members, while the importer's population had a significantly positive effect on the exports of Kuwait, Bahrain and Qatar, yet, a significantly negative effect on Saudi Arabia's exports. Borders had an insignificant effect on the exports of the six members. The common language had a significant and positive effect on the exports of Kuwait, Saudi Arabia, Bahrain and Oman. FTAs had a significantly positive effect on the exports of Bahrain and a significantly negative effect on Qatar's and Oman's exports. The membership of the GCC had a significantly positive effect on the exports of Kuwait, Bahrain and Qatar, while it had a negative effect on Saudi Arabia's exports.

Mass Spectrometry-Based Proteomic Profiling of Pseudopodia of Metastatic Cancer Cells

  • Choi, Sunkyu
    • Mass Spectrometry Letters
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    • v.11 no.2
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    • pp.25-29
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    • 2020
  • Pseudopodia are dynamic actin cytoskeleton-based membrane protrusions of cells that enable directional cell migration. Pseudopodia of cancer cells play key roles in cancer metastasis. Recent studies using pseudopodial subcellular fractionation methodologies combined with mass spectrometry-based proteomic profiling have provided insight into the pseudopodiome that control the protrusions of invasive metastatic cancer cells. This review highlights how to characterize the protein composition of pseudopodia and develop strategies to identify biomarkers or drug candidates that target reduction or prevention of metastatic cancer.