S. Ozaki¹, K. Hashiguchi², T. Okayasu², D.H. Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.18, No.2, pp. 101-120, 2007, DOI:10.3970/cmes.2007.018.101

Abstract In order to analyze precisely not only the elastoplastic deformation phenomenon of saturated particle assembly such as soils, grains, powdered and tablet medicines or three dimensional cellular materials, but also the frictional sliding phenomenon between saturated particle assembly and other bodies, a particle assembly-water coupled finite element program, that incorporates both the subloading surface and the subloading-friction models, is developed. Subsequently, simulations of the compaction behavior of saturated particle assembly under strain rate control are performed. It is revealed by the numerical experiment adopting the finite element program that the frictional sliding behavior of the contact boundary More >

Amado Alvarez^1,2, Enrique Rubiños Panta¹, Francisco Gavi Reyes¹, Juan José Alarcón Cabañero², Elizabeth Hernández Acosta³, Carlos Ramírez Ayala¹, Enrique Mejía Saenz¹, Francisco Pedrero Salcedo², Emilio Nicolas Nicolas², Enrique Salazar Sosa⁴

Phyton-International Journal of Experimental Botany, Vol.75, pp. 71-83, 2006, DOI:10.32604/phyton.2006.75.071

Abstract A water quality index as a standardized method to compare the category in an integral way, between locations and through time, of the different water, river and stream storages of the Amajac river basin was developed. In addition, it is possible to predict the degree of contamination and establish planning strategies in the management of the water resources for the river basin in issue. The used methodology was based in the quantitative expression of water quality. Three samplings were made (2005-2006) and Dissolved Oxygen, Coliform in feaces, pH, Oxygen Biochemical Demand, Nitrates, Total Phosphorus, Turbidity… More >

Bonvissuto GL¹, CA Busso^2,*

Phyton-International Journal of Experimental Botany, Vol.75, pp. 55-70, 2006, DOI:10.32604/phyton.2006.75.055

Abstract This study was conducted in the Monte Austral Neuquino (MAN), Provincia de Neuquén, Argentina (39°20’ S; 69°19’ W). Vegetation is distributed at the site as vegetation patches. There are two contrasting sites on the soil of these patches: location 1, under the canopy of major perennial grasses and shrubs, and location 2, which includes the vegetation uncovered interspaces between the patches. The hypothesis of this work was that hydraulic lift is greater under than between the vegetation patches. Thermocouple psychrometers were placed under the shrubs and in the interspaces in each of two vegetation patches,… More >

Rincón-Tuexi¹, Sergio Castro-Nava², José Alberto López-Santillán², Alfredo J Huerta³, Carlos Trejo-López⁴, Florencio Briones-Encinia

Phyton-International Journal of Experimental Botany, Vol.75, pp. 31-40, 2006, DOI:10.32604/phyton.2006.75.031

Abstract Effects of water and high temperature stresses, either separately or in combination, over biomass accumulation, grain yield and its direct components grain number per ear and individual grain weight], as well as harvest index were determined in four tropical maize populations. Results indicated that water stress do not significantly affect the studied variables, due to the absence of a severe water stress during flowering. This was the result of the fallen precipitation at this time. The most important factor in this study was high temperature, which significantly reduced all studied variables, except individual grain weight.… More >

A. Wacher¹, D. Givoli²

CMES-Computer Modeling in Engineering & Sciences, Vol.15, No.3, pp. 147-164, 2006, DOI:10.3970/cmes.2006.015.147

Abstract The recently proposed String Gradient Weighted Moving Finite Element (SGWMFE) method is extended to include remeshing and refining. The method simultaneously determines, at each time step, the solution of the governing partial differential equations and an optimal location of the finite element nodes. It has previously been applied to the nonlinear time-dependent two-dimensional shallow water equations, under the demanding conditions of large Coriolis forces, inducing large mesh and field rotation. Such effects are of major importance in geophysical fluid dynamics applications. Two deficiencies of the original SGWMFE method are (1) possible tangling of the mesh… More >

H.K. Mebatsion¹, P. Verboven¹, Q. T. Ho¹, F. Mendoza¹, B. E. Verlinden², T. A. Nguyen¹, B. M. Nicolaï^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.14, No.1, pp. 1-14, 2006, DOI:10.3970/cmes.2006.014.001

Abstract Modeling plant microstructure is of great interest to food engineers to study and explain material properties related to mass transfer and mechanical deformation. In this paper, a novel ellipse tessellation algorithm to generate a 2D geometrical model of apple tissue is presented. Ellipses were used to quantify the orientation and aspect ratio of cells on a microscopic image. The cell areas and centroids of each cell were also determined by means of a numerical procedure. These characteristic quantities were then described by means of probability density functions. The model tissue geometry was generated from the… More >

Sunil Punjabi¹, K. Muralidhar², P. K. Panigrahi²

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.2, pp. 95-106, 2006, DOI:10.3970/fdmp.2006.002.095

Abstract Convection in a differentially heated two-layer system consisting of air and water was studied experimentally, using laser-interferometry. The cavity used for flow visualization was square in cross-section and rectangular in-plan having dimensions of 447 × 32 × 32 mm³. Experiments performed over different layer thicknesses of water filled in a square cross-section cavity, the rest being air, are reported in the present work. The following temperature differences for each layer height were imposed across the hot and the cold walls of the superposed fluid layers: (i) ΔT=10K and (ii)ΔT =18 K. The present study was aimed… More >

X. Liu, A. Scarpas¹

CMES-Computer Modeling in Engineering & Sciences, Vol.9, No.1, pp. 57-74, 2005, DOI:10.3970/cmes.2005.009.057

Abstract Numerical investigations of strain localization have been performed on 3D dense fully saturated sand specimens subjected to triaxial loading and simultaneous inflow or outflow conditions. The role of the water suction field on the formation and evolution of strain localization is addressed computationally. It has been shown that, in a porous medium, the fluid (water) phase plays indeed an important role in strain localization. The formation and evolution of strain localization are influenced both by the material behaviour of the solid component and the interaction between components. In this contribution, after a presentation of the More >

B. Amaziane¹, A. Naji², D. Ouazar³, A. H.-D. Cheng⁴

CMC-Computers, Materials & Continua, Vol.2, No.2, pp. 85-96, 2005, DOI:10.3970/cmc.2005.002.085

Abstract In this paper the optimization of groundwater pumping in coastal aquifers under the threat of saltwater intrusion is investigated. The aquifer is inhomogeneous and contains several hydraulic conductivities zones. The aquifer data such as the hydraulic conductivities are uncertain, but with their expected mean and standard deviation values given. A stochastic boundary element method based on the perturbation technique is employed as the simulation tool. The stochastic optimization is handled by the chance-constrained programming. Genetic algorithm is selected as the optimization tool. Numerical examples of deterministic and stochastic problems are provided to demonstrate the feasibility More >

Q.W. Ma¹

CMES-Computer Modeling in Engineering & Sciences, Vol.9, No.2, pp. 193-210, 2005, DOI:10.3970/cmes.2005.009.193

Abstract Recently, the MLPG (Meshless Local Petrov-Galerkin Method) method has been successfully extended to simulating nonlinear water waves [Ma, (2005)]. In that paper, the author employed the Heaviside step function as the test function to formulate the weak form over local sub-domains, acquiring an expression in terms of pressure gradient. In this paper, the solution for Rankine sources is taken as the test function and the local weak form is expressed in term of pressure rather than pressure gradient. Apart from not including pressure gradient, velocity gradient is also eliminated from the weak form. In addition, More >