Going to the churches of the Evangelio: Children's Perspectives on Religion in an Indigenous Urban Setting in Buenos Aires

The aim of this article is to reconstruct child perspectives on religion and to analyze them in the context of their participation in social practices (such as family transmission, peer and sibling relationships, and practices within the evangelical community´s churches and a catholic school). For my research, I articulate an ethnographic approach using other methods and fieldwork techniques (usually used in anthropology of childhood, as are certain psychological approaches to children´s points of view), that became fundamental strategies for approaching child voices and practices. In doing so, issues of method and epistemology were contemplated, seeking for ways to critically analyze the link between religious and ethnic identifications. By considering the ways children articulate their own perspectives on the social processes they are involved in, I will specially focus on how Toba children constitute the meaning of the Evangelio (Gospel) religious movement over time.Fil: Garcia Palacios, Mariana Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Optimal boundary geometry in an elasticity problem: a systematic adjoint approach

p. 509-524In different problems of Elasticity the definition of the optimal geometry of the boundary, according to a given objective function, is an issue of great interest. Finding the shape of a hole in the middle of a plate subjected to an arbitrary loading such that the stresses along the hole minimizes some functional or the optimal middle curved concrete vault for a tunnel along which a uniform minimum compression are two typical examples. In these two examples the objective functional depends on the geometry of the boundary that can be either a curve (in case of 2D problems) or a surface boundary (in 3D problems). Typically, optimization is achieved by means of an iterative process which requires the computation of gradients of the objective function with respect to design variables. Gradients can by computed in a variety of ways, although adjoint methods either continuous or discrete ones are the more efficient ones when they are applied in different technical branches. In this paper the adjoint continuous method is introduced in a systematic way to this type of problems and an illustrative simple example, namely the finding of an optimal shape tunnel vault immersed in a linearly elastic terrain, is presented.Garcia-Palacios, J.; Castro, C.; Samartin, A. (2009). Optimal boundary geometry in an elasticity problem: a systematic adjoint approach. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/654

A large displacement structural analysis of a pipeline subjected to gravity and bouyancy forces

p. 489-508A nonlinear analysis of an elastic tube subjected to gravity forces and buoyancy pressure is carried out. An update lagrangian formulation is used. The structural analysis efficiency in terms of computer time and accuracy, has been improved when load stiffness matrices have been introduced. In this way the follower forces characteristics such as their intensity and direction changes can be well represented. A sensitivity study of different involved variables on the final deformed pipeline shape is carried out.Mosquera, JC.; Garcia-Palacios, J.; Samartin, A. (2009). A large displacement structural analysis of a pipeline subjected to gravity and bouyancy forces. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/654

Hybrid finite elements for axially loaded elasto-plastic bars

This work reports on the formulation, implementation and validation of hybrid finite elements for elasto-plastic axially loaded bars, under quasi-static conditions. The equations governing the axially loaded bars are defined for both elastic and elastoplastic ranges. Two different hardening models are considered, kinematic and isotropic. The solution of the governing equations involves their discretization in time and space. The discretization in time is made by expanding in Euler series the time variation of the involved quantities and the integration in space is performed using the hybrid finite element method. Independent approximations of the displacement and plastic strain fields are made in the domain of each finite element using Chebyshev polynomials. Unlike conforming displacement finite elements, the bases are hierarchical and not linked in any way to the nodes of the mesh. The hybrid finite element formulation is derived by enforcing the weak form of the governing equations using the Garlerkin method. The computational implementation of the formulation is developed in the Matlab environment. The implementation offers considerable flexibility for the definition of the structure and its loads, the time steps and the finite element mesh. To validate the implementation and assess the convergence properties of the hybrid formulation, a problem with known analytic solution is used. The displacement and stress solution errors are measured and their reduction rates under mesh (h-), basis (p-) and time step (t-) refinements are computed to understand their relative effect on the quality of the solution. A second problem with a higher complexity level is used to illustrate the performance of the formulation when confronted to multiple loading and unloading cycles, that lead to partial and total yielding under traction and compression regimes