Surkay D. Akbarov^1,2, Tamer Kepceler¹, M. Mert Egilmez¹

CMC-Computers, Materials & Continua, Vol.30, No.1, pp. 83-98, 2012, DOI:10.3970/cmc.2012.030.083

Abstract This paper develops the investigations started in a work by Akbarov, Kepceler and Mert Egilmez (2011) and studies the some particularities of the torsional wave dispersion in a finitely pre-deformed sandwich hollow cylinder. The mentioned particularities relate to the influence of the stiffness ratio of the core and face layers' materials and the influence of the thickness ratio of these layers on the dispersion character of the wave under consideration. Moreover, the mentioned influences are studied for the various values of the parameter which characterizes the initial strains in the cylinder's layers. The mechanical relations More >

Chih-Wen Chang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.88, No.2, pp. 65-92, 2012, DOI:10.3970/cmes.2012.088.065

Abstract We utilize a regularized integral equation scheme to resolve the three-dimensional backward advection-dispersion equation (BADE) for identifying the groundwater pollution source identification problems in this research. First, the Fourier series expansion method is employed to estimate the concentration field C(x, y, z, t) at any time t < T. Second, we contemplate a direct regularization by adding an extra term a(x, y, z, 0) to transform a second-kind Fredholm integral equation for C(x, y, z, 0). The termwise separable property of the kernel function permits us to acquire a closed-form regularized solution. In addition, a More >

A. Belcaid^1,2, G. Le Palec², A. Draoui¹, Ph. Bournot¹

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.2, pp. 241-256, 2012, DOI:10.3970/fdmp.2012.008.241

Abstract The study is focused on numerical simulation of the process of coastal pollution by wastewater in the Bay of Tangier in Morocco. The process is governed by flows generated by the tide and the large variations of the discharges from the different Wadis (rivers) flowing into the bay. The simulation requires a number of tests and trials, something that is experimentally expensive and sometimes impossible. Hence the idea was developed of a numerical study aimed at tracking the dispersion of pollutants into the bay and determining the level of degradation of its waters. The simulation… More >

Ryoichi Yamamoto

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.2, pp. 37-38, 2011, DOI:10.3970/icces.2011.018.037

Abstract We developed a unique method for direct numerical simulations (DNS) of dense colloidal dispersions [3, 5]. This method, called the smoothed profile method (SPM), enables us to compute the time evolutions of colloidal particles, ions, and host fluids simultaneously by solving Newton, advection-diffusion, and Navier-Stokes equations so that the electro- hydrodynamic couplings can be fully taken into account. We have applied the SPM successfully for simulating dynamics of various particle dispersions, including colloids in liquid crystals [1, 2], electrophoresis of charged colloids [4, 5], particle diffusion in fluids [7, 8], dispersion rheology [9, 11], tumbling More >

Surkay D. Akbarov^1,2, Tamer Kepceler¹, M. Mert Egilmez¹, Ferhat Dikmen¹

CMC-Computers, Materials & Continua, Vol.26, No.2, pp. 91-110, 2011, DOI:10.3970/cmc.2011.026.091

Abstract This paper studies the torsional wave dispersion in the hollow bi-material compounded cylinder with finite initial strains. The investigations are carried out within the scope of the piecewise homogeneous body model with the use of the three-dimensional linearized theory of elastic waves in initially stressed bodies. The mechanical relations of the materials of the cylinders are described through the harmonic potential. The numerical results on the influence of the initial stretching or compression of the cylinders along the torsional wave propagation direction are presented and discussed More >

Abhijit Sarkar¹, M. V. Kunte², Venkata R. Sonti²

CMES-Computer Modeling in Engineering & Sciences, Vol.81, No.3&4, pp. 249-268, 2011, DOI:10.3970/cmes.2011.081.249

Abstract In this article, we show with some formalism that infinite flexible structural acoustic waveguides have a general form for the dispersion equation. The dispersion equation of all such waveguides should conform to a generic form. This allows us to bring out the common features of structural acoustic waveguides. We take three examples to demonstrate this fact, namely, the rectangular, the circular cylindrical and the elliptical geometries. Where necessary, the equations are simplified for applicability to a particular frequency-regime before demonstrating the conformance to the generic form of the dispersion relation. It is then shown that More >

Gongsheng Li¹, De Yao², Hengyi Jiang³, Xianzheng Jia¹

CMES-Computer Modeling in Engineering & Sciences, Vol.74, No.2, pp. 83-108, 2011, DOI:10.3970/cmes.2011.074.083

Abstract This paper deals with an inverse problem of determining a time-depen -dent reaction coefficient arising from a disturbed soil-column infiltrating experiment based on measured breakthrough data. A purpose of doing such experiment is to simulate and study transport behaviors of contaminants when they vertically penetrating through the soils. Data compatibility of the inverse problem is discussed showing a sufficient condition to the solution's monotonicity and positivity with the help of an adjoint problem. Furthermore, an optimal perturbation regularization algorithm is applied to solve the inverse problem, and two typical numerical examples are presented to support More >

H. Chanson¹, K.K. Tan²

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.4, pp. 403-418, 2011, DOI:10.3970/fdmp.2011.007.403

Abstract A tidal bore is a wall of water propagating upstream as the tidal flow turns to rising into an estuary with a tidal range larger than 5 to 6 m and the bathymetry that amplifies the tidal wave. The bore front is a shock characterised by a singularity of the free-surface and pressure and velocity fields. This study aims to characterise the impact of tidal bores on the turbulent dispersion of fish eggs. Some physical modelling was performed based upon a Froude similitude and the tracking of plastic beads acting as fish egg proxies was More >

R. Abdeljabar¹

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.2, pp. 217-230, 2011, DOI:10.3970/fdmp.2011.007.217

Abstract In this paper, we discuss a new technique for desalination based on the principles of the Soret effect. In particular, the method stems from the peculiar behavior of the solute in a solution of sodium chloride (i.e. salty water layer) of uniform concentration being less or equal to 5wt% under the effect of an imposed temperature gradient with average temperature equal to 12oC. The Soret coefficient may be positive or negative according to whether the temperature of the solution is above or below 12oC. As two diffusion processes (one parallel to the temperature gradient and… More >

Galindo-Tovar¹ ME, AM Arzate-Fernández²

Phyton-International Journal of Experimental Botany, Vol.79, pp. 203-207, 2010, DOI:10.32604/phyton.2010.79.203

Abstract Origin of West Indian avocado has been explained by current-day factors, such as abundance patterns; however, it is still unclear where it originated. Anyhow, there is a history behind the species that reflects, in one way or another, the present geographic distribution and species characteristics. We examined paleohistorical and paleoecological data to explore the West Indian avocado origin. Our results suggest that West Indian avocado originated by domestication and ecological adaptation in the Maya Lowland area; this is where this botanical variety of avocado has an ancient history. More >