Ning Wang^*

Molecular & Cellular Biomechanics, Vol.7, No.1, pp. 33-44, 2010, DOI:10.3970/mcb.2010.007.033

Abstract Professor Y.C. Fung has shown that living tissues remodel extensively in response to mechanical forces such as blood pressure variations. At the cellular level, those mechanical perturbations must be perceived by individual cells. However, mechanisms of mechanochemical transduction in living cells remain a central challenge to cell biologists. Contrary to predictions by existing models of living cells, we reported previously that a local stress, applied via integrin receptors, is propagated to remote sites in the cytoplasm and is concentrated at discrete foci. Here we report that these foci of strains and stresses in the cytoplasm More >

S.L. Li^1,2, S.Y. Long¹, G.Y. Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.60, No.1, pp. 73-94, 2010, DOI:10.3970/cmes.2010.060.073

Abstract A new implementation of topology optimization for the plate described by the Reissner-Mindlin theory based on the meshless natural neighbour Petrov-Galerkin method (NNPG) is proposed in this work. The objective is to produce the stiffest plate for a given volume by redistributing the material throughout the plate. We try to couple the advantages of the meshless numerical method with the topology optimization of moderately thick plate. The numerical approach presented here is based on the solid isotropic material with penalization (SIMP) formulation of the topology optimization problem. The natural neighbour interpolation shape function is employed More >

A. Papacharalampopoulos², G. F. Karlis², A. Charalambopoulos³, D. Polyzos⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.58, No.1, pp. 45-74, 2010, DOI:10.3970/cmes.2010.058.045

Abstract A Boundary Element Method (BEM) for solving two (2D) and three dimensional (3D) dynamic problems in materials with microstructural effects is presented. The analysis is performed in the frequency domain and in the context of Mindlin's Form II gradient elastic theory. The fundamental solution of the differential equation of motion is explicitly derived for both 2D and 3D problems. The integral representation of the problem, consisting of two boundary integral equations, one for displacements and the other for its normal derivative is exploited for the proposed BEM formulation. The global boundary of the analyzed domain More >

D.P. Boso¹, M. Lefik²

CMES-Computer Modeling in Engineering & Sciences, Vol.55, No.3, pp. 319-338, 2010, DOI:10.3970/cmes.2010.055.319

Abstract In this paper we study numerically the mechanical behaviour of wire ropes, particularly the influence of the geometrical configuration on the overall stiffness of the cables. Modelling the behaviour of a cable is a difficult problem, given the complexity of the geometrical layout, contact phenomena occurring among wires and possible yielding of the material. For this reason we pursue a "hierarchical beam approach", to substitute recursively, at each cabling stage, the bundle of wires with an equivalent single strand, having the characteristics computed from the previous level. We consider the first two levels of the… More >

Veturia Chiroiu¹, Ligia Munteanu¹, Pier Paolo Delsanto²

CMC-Computers, Materials & Continua, Vol.16, No.1, pp. 75-100, 2010, DOI:10.3970/cmc.2010.016.075

Abstract Conventional continuum theories are unable to capture the observed indentation size effects, due to the lack of intrinsic length scales that represent the measures of nanostructure in the constitutive relations. In order to overcome this deficiency, the Toupin-Mindlin strain gradient theory of nanoindentation is formulated in this paper and the size dependence of the hardness with respect to the depth and the radius of the indenter for multiple walled carbon nanotubes is investigated. Results show a peculiar size influence on the hardness, which is explained via the shear resistance between the neighboring walls during the More >

J. Sladek¹, V. Sladek¹, P. Stanak¹, Ch. Zhang²

CMC-Computers, Materials & Continua, Vol.15, No.1, pp. 1-26, 2010, DOI:10.3970/cmc.2010.015.001

Abstract A meshless local Petrov-Galerkin (MLPG) method is applied to solve laminate plate problems described by the Reissner-Mindlin theory. Both stationary and transient dynamic loads are analyzed here. The bending moment and the shear force expressions are obtained by integration through the laminated plate for the considered constitutive equations in each lamina. The Reissner-Mindlin theory reduces the original three-dimensional (3-D) thick plate problem to a two-dimensional (2-D) problem. Nodal points are randomly distributed over the mean surface of the considered plate. Each node is the center of a circle surrounding this node. The weak-form on small More >

Diniz SPSS, RC Oliveira

Phyton-International Journal of Experimental Botany, Vol.78, pp. 155-160, 2009, DOI:10.32604/phyton.2009.78.155

Abstract The effects of fusaric acid, a mycotoxin produced by Fusarium sp, were investigated in relation to its action on corn seedlings. The mycotoxin inhibited the development of corn seedlings at 0.2 mM, causing root length reduction. Anatomically, alterations were only visible from 0.5 mM fusaric acid, directly influencing the cell differentiation process. Precocious differentiation reduces the elongation region. This explains (1) that root shortening is morphologically visible, and (2) the differentiation of a great number of lateral roots nearby the apex, which can be seen in longitudinal cuts. More >

Fernanda Gentil¹, Renato Natal Jorge², António Joaquim Mendes Ferreira³, Marco Parente⁴, Pedro Martins⁵, Eurico de Almeida⁶

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.1, pp. 45-56, 2009, DOI:10.3970/icces.2009.009.045

Abstract The interest in finite element method (FEM) concerning biomechanics has been increasing, in particular, to analyze the mechanical behavior of the human ear. In this work, a finite element model of the middle ear was made. A dynamic study based on a structural response to harmonic vibrations, for different sound pressure levels, applied on the eardrum, is presented using the ABAQUS program. The model includes different ligaments and muscle tendons with elastic and hyperelastic behavior of these supportive structure. The non-linear behavior of the ligaments and muscle tendons was considered, being the connection between ossicles More >

A. Colombo¹, U. Galvanetto²

CMES-Computer Modeling in Engineering & Sciences, Vol.53, No.3, pp. 235-254, 2009, DOI:10.3970/cmes.2009.053.235

Abstract The paper addresses the problem of computing the stable manifolds of equilibria and limit cycles of saddle type in piecewise smooth dynamical systems. All singular points that are generically present along one-dimensional or two-dimensional manifolds are classified and such a classification is then used to define a method for the numerical computation of the stable manifolds. Finally the proposed method is applied to the case of a stick-slip oscillator. More >

A. B. Mahmud Hasan^1,2, S.M. Guo¹, M.A. Wahab¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.4, pp. 399-410, 2009, DOI:10.3970/fdmp.2009.005.399

Abstract The effects of gas flow channel design were studied experimentally for increasing fuel cell performance and fuel optimization. Three types of gas flow channels (serpentine, straight and interdigitated) were designed on the basis of water flooding due to electrochemical reactions, electro-osmotic drag, etc. Experimental results indicate that the best cell performance can be obtained by arranging interdigitated gas flow channel at the anode side and serpentine gas flow channel at the cathode side. Detailed analysis on complex two phase water generation and electrochemical phenomena behind those results were analyzed in this work to find out More >