A. Delgado-Lima, M. C. Paiva^*, A. V. Machado

Journal of Renewable Materials, Vol.5, No.2, pp. 145-153, 2017, DOI:10.7569/JRM.2017.634104

Abstract Cellulose acetate (CA) is produced from a natural polymer and presents excellent properties, finding applications in a variety of areas. Unlike cellulose, CA is melt processable and may be molded into parts and formed into fibers or films. In this context, the production of conductive CA composites that may be processable and integrated into parts to provide specific functionalities is an area of increasing interest. The present work aims to prepare electrically conductive composites based on CA and carbon nanotubes (CNTs) by melt mixing. The nanocomposites were produced with pure and pyrrolidine-functionalized nanotubes, using a More >

S.D. Akbarov^1,2, M. Negin³

CMC-Computers, Materials & Continua, Vol.53, No.4, pp. 307-341, 2017, DOI:10.3970/cmc.2017.053.307

Abstract Dispersion of the generalized Rayleigh waves propagating in a covered half-space made of viscoelastic materials is investigated by utilizing the exact equations of the theory of linear viscoelasticity. The dispersion equation is obtained for an arbitrary type of hereditary operator of the materials of the constituents and a solution algorithm is developed for obtaining numerical results on the dispersion of the waves under consideration. Dispersion curves are presented for certain attenuation cases and the influence of the viscosity of the materials is studied through three rheological parameters of the viscoelastic materials which characterize the characteristic More >

Monique de Alvarenga Pinto Cotrim^1*, Jessyca Aparecida Paes Dutra², Suzana Gonçalves Carvalho², Janaina Cecília Oliveira Villanova², Eliane Ayres¹

Journal of Renewable Materials, Vol.4, No.1, pp. 9-17, 2016, DOI:10.7569/JRM.2015.634122

Abstract In recent years there has been an increasing demand for the application of natural products to address problems in the environment. The use of products derived from renewable resources can provide a sustainable strategy to replace totally or partially synthetic products. Cymbopogon, commonly known as lemongrass, is a tropical grass cultivated mostly for its essential oil, which has demonstrated several bioactivities, including antibacterial and antifungal properties. In the present work the formation of inclusion complex between β-cyclodextrin (β-CD) and lemongrass essential oil (LGEO) as well as its fi xation onto cotton fabric were investigated. Inclusion More >

S.D. Akbarov^1,2, T. Kocal³, T. Kepceler¹

CMC-Computers, Materials & Continua, Vol.51, No.2, pp. 105-143, 2016, DOI:10.3970/cmc.2016.051.105

Abstract The paper studies the dispersion of axisymmetric longitudinal waves in the bi-material compound circular cylinder made of linear viscoelastic materials. The investigations are carried out within the scope of the piecewise homogeneous body model by utilizing the exact equations of linear viscoelasto-dynamics. The corresponding dispersion equation is derived for an arbitrary type of hereditary operator and the algorithm is developed for its numerical solution. Concrete numerical results are obtained for the case where the relations of the constituents of the cylinder are described through fractional exponential operators. The influence of the viscosity of the materials… More >

Bouchmel Mliki, Mohamed Ammar Abbassi, Ahmed Omri

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.1, pp. 87-114, 2015, DOI:10.3970/fdmp.2015.011.087

Abstract MHD double-diffusive natural convective flow in a C-shaped enclosure filled with a Cu/Water nanofluid is investigated numerically using the Lattice Boltzmann Method (LBM). Much care is devoted to the validation of the numerical code. The effects exerted on the flow, concentration and temperature fields by different parameters such as the Rayleigh number (10³−10⁶), the nanoparticle volume concentration (0−0,1), the Lewis number (1-5), the Hartmann number (0−30) and different types of nanoparticles (Cu, Ag, Al₂O₃ and TiO₃ are assessed in detail. Results for stream function, Nusselt and Sherwood numbers are presented and discussed for various parametric conditions. Results More >

Xiaoming Zhang¹, Jiangong Yu^1,2, Min Zhang¹, Dengpan Zhang¹

CMC-Computers, Materials & Continua, Vol.48, No.3, pp. 163-179, 2015, DOI:10.3970/cmc.2015.048.163

Abstract The characteristics of the guided waves propagation in functionally graded rods with rectangular cross-section (finite width and height) under initial stress are investigated in this paper based on Biot’s theory of incremental deformation. An extended orthogonal polynomial approach is present to solve the coupled wave equations with variable coefficients. By comparisons with the available results of a rectangular aluminum rod, the validity of the present approach is illustrated. The dispersion curves and displacement profiles of various rectangular functionally graded rods are calculated to reveal the wave characteristics, and the effects of different width to height More >

Guoquan Nie^1,2, Jinxi Liu¹, Ming Li¹

CMC-Computers, Materials & Continua, Vol.48, No.3, pp. 133-145, 2015, DOI:10.3970/cmc.2015.048.133

Abstract Propagation of SH-type guided waves in a layered structure with an invariant initial stress is studied, where a piezoelectric thin layer is perfectly bonded on a piezomagnetic substrate. Both the layer and the substrate possess transversely isotropic property. The dispersion relations of SH waves are obtained for four kinds of different electro-magnetic boundary conditions. The effects of initial stress, thickness ratio and electro-magnetic boundary conditions on the propagation behaviors are analyzed in detail. The numerical results show that: 1) The positive initial stresses make the phase velocity increasing, while the negative initial stresses decrease the More >

S.D. Akbarov ^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.97, No.5, pp. 407-424, 2014, DOI:10.3970/cmes.2014.097.407

Abstract Flexural wave dispersion in a bi-material solid and hollow circular cylinders is investigated with the use of the three-dimensional linear theory of elastodynamics. It is assumed that on the interface surface of the cylinders the complete contact conditions satisfy. The analytical solution of the corresponding field equations is presented and, using these solutions, the dispersion equations for the cases under consideration are obtained. The dispersion equations are solved numerically and based on these solutions, dispersion curves are constructed for the concrete selected pairs of materials such as Tungsten (inner cylinder material) + Aluminum (outer cylinder More >

Hui Wei^1,2,3, Wen Chen^1,2,4, HongGuang Sun^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.2, pp. 85-103, 2014, DOI:10.3970/cmes.2014.100.085

Abstract The unknown parameters are critical factors in fractional derivative advection-dispersion equation describing the solute transport in soil. For examples, the fractional derivative order is the index of anomalous dispersion, diffusion coefficient represents the dispersion ability of media and average pore-water velocity denotes the main trend of transport, etc. This paper is to develop a homotopy method to determine the unknown parameters of solute transport with spatial fractional derivative advection-dispersion equation in soil. The homotopy method can be easily developed to solve parameter determination problems of fractional derivative equations whose analytical solutions are difficult to obtain. More >

Xiaoming Zhang¹, Xingxin Xu^1,2, Yuqing Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.1, pp. 1-17, 2014, DOI:10.3970/cmes.2014.100.001

Abstract Orthogonal polynomial approach has been used to deal with the wave propagation in structures that have finite dimension in only one direction, such as horizontally infinite flat plates, axially infinite hollow cylinders. In order to solve wave propagation in two-dimensional piezoelectric rod with rectangular cross section, i.e. the piezoelectric plate with finite dimensions in two directions, an extended orthogonal polynomial approach is proposed in this paper. For validation and illustration purposes, the proposed approach is applied to solving the wave propagation in a square steel rod. The results obtained are in good agreement with the More >