P. Bala Anki Reddy^a,*, S. Suneetha^b

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-11, 2017, DOI:10.5098/hmt.8.24

Abstract We report on a mathematical model for analyzing the effects of homogeneous-heterogeneous chemical reaction and slip velocity on the MHD stagnation point flow of electrically conducting micropolar fluid over a stretching/shrinking surface embedded in a porous medium. The governing boundary layer coupled partial differential equations are transformed into a system of non-linear ordinary differential equations, which are solved numerically using the MATLAB bvp4c solver. The effects of physical and fluid parameters such as the stretching parameter, micropolar parameter, permeability parameter, strength of homogeneous and heterogeneous reaction parameter on the velocity and concentration are analyzed, and More >

Wenjie Dong, Chenlu Wang, Minyan Gu, Long Yang, Zheng Shen^*, Yalei Zhang^*

Journal of Renewable Materials, Vol.5, Suppl.1, pp. 22-30, 2017, DOI:10.7569/JRM.2017.634126

Abstract Lactic acid can not only be used to produce multiple chemicals, but can also be the building block for biodegradable and biocompatible polylactic acid identified as a renewable resource. As a by-product in biodiesel production, the glycerol yield increases with a rapid expansion of biodiesel. However, in the chemical and environmental fields it is still a great challenge to produce lactic acid or methyl lactate from glycerol. Herein, Sn-Beta zeolite was prepared through solid-state ion exchange (Sn-Beta SSIE) and was tested for base-free one-pot catalytic selective oxidation of glycerol into methyl lactate in methanol. The More >

María Belén Colombo Migliorero, Valeria Palermo^*, Patricia Graciela Vázquez, Gustavo Pablo Romanelli

Journal of Renewable Materials, Vol.5, No.3-4, pp. 167-173, 2017, DOI:10.7569/JRM.2017.634108

Abstract The utilization and valorization of industrial waste is an effective strategy for environmental protection. Since the juice industry generates a huge amount of citrus waste, we studied the application of thermally treated orange peel in catalysis. On the other hand, Keggin heteropolyacids are excellent oxidant catalysts used as a replacement for conventional oxidants; however, their solubility in polar solvents and the low specific area limit their use as heterogeneous catalysts. The utilization of treated orange peel as heteropolyacid support for the selective oxidation of sulfides is presented here. Firstly, orange peel was thermally treated, and More >

C. S. K. Raju^a , N. Sandeep^a, J. Prakash^b,1

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-8, 2016, DOI:10.5098/hmt.7.14

Abstract In this study, we analyzed the effects of nonlinear thermal radiation and induced magnetic field on steady two-dimensional incompressible flow of Jeffrey fluid flow past a stretching/shrinking surface in the presence of homogeneous-heterogeneous reactions. For physical relevance in this study we analyzed the behavior of homogeneous and heterogeneous profiles individually. The transformed governing equations with the help of similarity variables are solved numerically via Runge-Kutta and Newton’s method. We obtained better accuracy of the present results by differentiating with the existed published literature. The effect of pertinent parameters on velocity, induced magnetic field, temperature and More >

Wenxiang Xu^1,2,3,4, Ganquan Yang⁵, Peng Lan², Huaifa Ma¹

CMC-Computers, Materials & Continua, Vol.52, No.1, pp. 25-40, 2016, DOI:10.3970/cmc.2016.052.025

Abstract Understanding the excluded volume of anisotropic particle is of great importance in the evaluation of continuum percolation and random packing behaviors of soft/hard particle systems in heterogeneous disordered media. In this work, we obtain the excluded volumes of several anisotropic convex particles including prolate spheroids, oblate spheroids, spherocylinders, and Platonic particles, using theoretical and numerical approaches. According to the second virial coefficient, we first present a theoretical scheme for determining the excluded volumes of anisotropic particles. Also, the mean tangent diameters of anisotropic convex particles are formulated by the quantitative stereology. Subsequently, Monte Carlo simulations… More >

Isa Ahmadi¹, M.M. Aghdam²

CMES-Computer Modeling in Engineering & Sciences, Vol.108, No.1, pp. 21-48, 2015, DOI:10.3970/cmes.2015.108.021

Abstract In this study, a truly meshless method based on the meshless local Petrov-Galerkin method is formulated for analysis of the elastic-plastic behavior of heterogeneous solid materials. The incremental theory of plasticity is employed for modeling the nonlinearity of the material behavior due to plastic strains. The well-known Prandtl-Reuss flow rule of plasticity is used as the constitutive equation of the material. In the presented method, the computational cost is reduced due to elimination of the domain integration from the formulation. As a practical example, the presented elastic-plastic meshless formulation is employed for micromechanical analysis of More >

Y. T. Wu¹, Y. F. Nie², Z. H. Yang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.4, pp. 297-325, 2014, DOI:10.3970/cmes.2014.099.297

Abstract Four representative multiscale methods, namely asymptotic homogenization method (AHM), heterogeneous multiscale method (HMM), variational multiscale (VMS) method and multiscale finite element method (MsFEM), for elliptic problems with multiscale coefficients are surveyed. According to the features they possess, these methods are divided into two categories. AHM and HMM belong to the up–down framework. The feature of the framework is that the macroscopic solution is solved first with the help of effective information computed in local domains, and then the multiscale solution is resolved in local domains using the macroscopic solution when necessary. VMS method andMsFEM fall More >

Leiting Dong^1,2, Satya N. Atluri^1,3

CMC-Computers, Materials & Continua, Vol.33, No.2, pp. 111-154, 2013, DOI:10.3970/cmc.2013.033.111

Abstract In this study, SGBEM Voronoi Cells (SVCs), with each cell representing a grain of the material at the micro-level, are developed for direct micromechanical numerical modeling of heterogeneous composites. Each SVC can consist of either a (each with a different) homogenous isotropic matrix, and can include micro-inhomogeneities such as inclusions, voids of a different material, and cracks. These inclusions and voids in each SVC can be arbitrarily-shaped, such as circular, elliptical, polygonal, etc., for 2D problems. Further, the cracks in each SVC can be fully-embedded, edge, branching, or intersecting types, with arbitrary curved shapes. By… More >

D.S. Liu^1,2, Z.H. Fong¹, I.H. Lin¹, Z.W. Zhuang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.6, pp. 441-468, 2013, DOI:10.3970/cmes.2013.093.441

Abstract In this study, we proposed a novel numerical technique to simulate the transient moisture diffusion process and to apply it to heterogeneous composite resins. The method is based on a heterogeneous hybrid moisture element (HHME), with properties determined through an equivalent hybrid moisture capacitance/ conductance matrix that was calculated using the conventional finite element formulation in space discretization and the q-method in time discretization, with similar mass/stiffness properties and matrix condensing operations. A coupled HHME with finite element scheme was developed and implemented in the computer code by using the commercial software MATLAB to analyze… More >

Leiting Dong^1,2, Salah H. Gamal³, Satya N. Atluri^2,4

CMC-Computers, Materials & Continua, Vol.37, No.1, pp. 1-21, 2013, DOI:10.3970/cmc.2013.037.001

Abstract In this paper, a simple and reliable procedure of stochastic computation is combined with the highly accurate and efficient Trefftz Computational Grains (TCG), for a direct numerical simulation (DNS) of heterogeneous materials with microscopic randomness. Material properties of each material phase, and geometrical properties such as particles sizes and distribution, are considered to be stochastic with either a uniform or normal probabilistic distributions. The objective here is to determine how this microscopic randomness propagates to the macroscopic scale, and affects the stochastic characteristics of macroscopic material properties. Four steps are included in this procedure: (1)… More >