Marcello Lappa^{1, 2}

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.1, pp. 1-20, 2005, DOI:10.3970/fdmp.2005.001.001

Abstract Possible natural transport mechanisms in cubical and shallow cavities with different heating conditions (from below or from the side) are investigated by means of numerical solution of the non-linear model equations and multiprocessor computations. Attention is focused on a variety of three-dimensional steady effects that can arise in such configurations in the case of low-Pr liquids (silicon melt) even for relatively small values of the temperature gradient due to localized boundary effects and/or true instabilities of the flow. Such aspects are still poorly known or completely ignored owing to the fact that most of the More >

Eduardo Divo¹, Alain J. Kassab²

CMC-Computers, Materials & Continua, Vol.2, No.4, pp. 277-288, 2005, DOI:10.3970/cmc.2005.002.277

Abstract A Dual Reciprocity Boundary Element Method is formulated to solve non-linear heat conduction problems. The approach is based on using the Kirchhoff transform along with lagging of the effective non-linear thermal diffusivity. A posteriori error estimate is used to provide effective estimates of the temporal and spatial error. A numerical example is used to demonstrate the approach. More >

Julieta António^1,2, António Tadeu², Luís Godinho², Nuno Simões²

CMC-Computers, Materials & Continua, Vol.2, No.1, pp. 1-12, 2005, DOI:10.3970/cmc.2005.002.001

Abstract The evaluation of heat propagation in the time domain generated by transient heat sources placed in the presence of three-dimensional media requires the use of computationally demanding numerical schemes. The implementation of numerical 3D solutions may benefit from the existence of benchmark solutions to test the accuracy of approximate schemes.
With this purpose inmind, this article presents analyticalnumerical solutions to evaluate the heat-field elicited by monopole heat sources in the presence of three different inclusions, namely, a cylindrical circular solid inclusion, a cylindrical circular cavity with null fluxes and a cavity with null temperatures prescribed along… More >

Yoshihiro Ochiai¹, Vladimir Sladek²

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.6, pp. 525-536, 2004, DOI:10.3970/cmes.2004.006.525

Abstract The conventional boundary element method (BEM) uses internal cells for the domain integralsCwhen solving nonlinear problems or problems with domain effects. This paper is concerned with conversion of the domain integral into boundary ones and some non-integral terms in a three-dimensional BIEM, which does not require the use of internal cells. This method uses arbitrary internal points instead of internal cells. The method is based on a three-dimensional interpolation method in this paper by using a polyharmonic function with volume distribution. In view of this interpolation method, the three-dimensional numerical integration is replaced by boundary More >

António Tadeu¹, Julieta António and Nuno Simões

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.1, pp. 43-58, 2004, DOI:10.3970/cmes.2004.006.043

Abstract This Analytical Green's functions for the steady-state response of homogeneous three-dimensional unbounded, half-space, slab and layered solid media subjected to a spatially sinusoidal harmonic heat line source are presented. In the literature, this problem is frequently referred to as the two-and-a-half dimensional fundamental solution or 2.5D Green's functions.
The proposed equations are theoretically interesting in themselves and they are also useful as benchmark results for validating numerical applications. They are also of great practical use in the formulation of three dimensional heat transfer problems in layered solid formations using integral transform methods and/or boundary elements.… More >

J. Sladek¹, V. Sladek¹, S.N. Atluri²

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.3, pp. 309-318, 2004, DOI:10.3970/cmes.2004.006.309

Abstract Meshless methods based on the local Petrov-Galerkin approach are proposed for solution of steady and transient heat conduction problem in a continuously nonhomogeneous anisotropic medium. Fundamental solution of the governing partial differential equations and the Heaviside step function are used as the test functions in the local weak form. It is leading to derive local boundary integral equations which are given in the Laplace transform domain. The analyzed domain is covered by small subdomains with a simple geometry. To eliminate the number of unknowns on artificial boundaries of subdomains the modified fundamental solution and/or the More >

B. Mochnacki¹, E. Majchrzak²

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 431-438, 2003, DOI:10.3970/cmes.2003.004.431

Abstract In the paper the analysis of transient temperature field in the domain of biological tissue subjected to an external heat source is presented. Because of the geometrical features of the skin the heat exchange in domain considered is assumed to be one-dimensional. The thermophysical parameters of successive skin layers (dermis, epidermis and sub-cutaneous region) are different, at the same time in sub-domains of dermis and sub-cutaneous region the internal heat sources resulting from blood perfusion are taken into account. The degree of the skin burn results from the value of the so-called Henriques integrals. The More >

MARIANA N. MELCHIORRE, HERNÁN R. LASCANO, VICTORIO S.TRIPPI

BIOCELL, Vol.26, No.2, pp. 217-223, 2002, DOI:10.32604/biocell.2002.26.217

Abstract Wheat (Triticum aestivum) transgenic plants of an important commercial cv (Oasis) was obtained with an efficient and short procedure. First, the optimum conditions for the embriogenic calli generation from inmature embryos with a high regeneration percentage were established. The transformation of calli was performed by high velocity microprojectile bombardment, using the pAHC25 plasmid, which contains the reporter gene β-glucuronidase (GUS) and the selectable BAR gene which confers resistance to the herbicide Basta. The transformations were confirmed by β-glucuronidase assay activity, PCR and Southern blot analysis. The efficiency of this procedure was high and similar to other More >

DANIELA CARVALHO DOS SANTOS, ELISA APARECIDA GREGÓRIO

BIOCELL, Vol.26, No.2, pp. 229-235, 2002, DOI:10.32604/biocell.2002.26.229

Abstract The ultrastructure of the ovariole sheath along the Diatraea saccharalis ovariole was studied by scanning and transmission electron microscopy. Each ovariole is surrounded by an epithelial sheath, a tunica propria and scattered lumen cells. These three components of the ovariole sheath show different ultrastructural features along the ovariole, in the germarium or in the vitellarium; these differences are more evident in the epithelial sheath cells. The epithelial sheath is composed by two layers of cells, the external one running longitudinally and the internal one running circularly in the ovariole. These cells, in vitellarium, present cytoplasmic bundles More >

Y. Ochiai

CMES-Computer Modeling in Engineering & Sciences, Vol.2, No.4, pp. 435-446, 2001, DOI:10.3970/cmes.2001.002.435

Abstract The boundary element method (BEM) is useful in solving the steady heat conduction problem of orthotropic bodies without heat generation. However, for cases with arbitrary heat generation, a number of internal cells are necessary. In this paper, it is shown that the problem of steady heat conduction in orthotropic bodies with heat generation can be solved without internal cells by the triple-reciprocity BEM. In this method, the distribution of heat generation is interpolated using integral equations. In order to solve the problem, the values of heat generation at internal points and on the boundary are More >