Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The development of variational formulations for thin and thick beams with softening discontinuities adapted to represent strain localization is presented. The formulation for thin beams takes into account the internal strain energy due to bending induced strains, in which the discontinuities are considered as softening hinges. For the case of thick beams, the formulation takes into account the internal strain energy due to bending and shear strains, in which the discontinuities are considered as softening hinges/dislocations. These formulations include the embedded discontinuity model, in which the discontinuity and the strain concentration are lumped into a zero-thickness localization zone. The non-linear behavior of the material is described by a discrete constitutive model, in which linear or exponential softening is considered. The boundary value problems and closed form solutions are developed from the variational formulations and the conventional methods of calculus of variations. The application of closed form solutions to practical examples modeled numerically guarantees the accuracy of the developed solutions.

Three criteria to estimate the crack bandwidth in fracture analyses using continuum damage models are evaluated. The approach developed by Juarez et al. (2021) for closed form solutions was implemented in the finite element method. Four cases were studied, from which the load-displacement curves of the fracture process were obtained. In these examples, the dissipated fracture energy was congruent with the magnitude expected in all the cases studied. Some drawbacks like mesh dependance and elastic energy locking occurred when using empirical formulas to compute the crack bandwidth. From the results, recommendations are given to compute crack bandwidths.

The objective of this work was to measure the expropriating and destructive character that colonialism has had and still has on the reality of indigenous peoples, and how colonialism continues to cast its shadows of destruction globally in times of ecological annihilation. We consider the indigenous-commons as the nucleus from which to understand the proposal of transformation and community resistance of indigenous peoples; the place that gives foundation and meaning to their political practice of rights. We have moved towards a political critique of the concept of Rights of Nature, in a double sense: as a critique of what it is not, of its misrepresentation by the State; as an alternative proposal to understand the centrality that the ecology of living beings has in indigenous worldviews. Finally, we conclude with what we consider the main fractures in the protection of indigenous rights, gaps that ultimately rest on the need to annul and destroy the indigenous understanding of life (s) due to the critical potential that they imply for the new colonial reason.

Equality as an historic process of human emancipation, transcends the strictly legal/formal plane. Furthermore, it is enhanced by the “historic” willingness to democratise society and improve people’s lives. This is the materialistic dimension of the principle of equality, this ethical and historical “willingness” based on the production and development of social justice as a criterion and principle for action. Human rights and democracy, with their fighting practices and traditions, cannot be understood today without the idea of equality as a necessary principle. Human rights have always been linked to processes of reaction against inequalities. They have been and remain a reaction to any kind of oppression and/or domination, because human rights, which are rights and are human, are always actions that refer to human beings in need. The fact that they were formally conceived under the umbrella of normative reasoning does not presuppose that they should be conceived exclusively as individual rights, which demand fulfilment in the future, or even as horizons of possibility (idealistic vision), but as ways of life that make human existence – dignified existence – feasible for all people. The idea of equality is, therefore, not possible without this material judgement of existence.

The isolationist presidency of Donald Trump was only the last, albeit the most radical, of a series of United States administrations that have largely ignored fostering close relations with Latin America and the Caribbean. This apparent withdrawal has resulted in the steady rise of Brazil as a significant regional power as well as the incursion of Russian and Chinese influence in the region. In light of these developments, this article presents a historical overview of United States hegemony in the western hemisphere before outlining how recent setbacks have undermined this trend in the areas of regional trade, diplomacy, and security. As the Biden administration makes its transition, the article finishes by proposing how the United States could regain influence in the region by collaborating with its southern neighbors to promote economic development, defend human rights, and confront the region’s ongoing security issues.

 

The concept of sovereignty and laicism still being instrumented into different projection to that’s which have been conceived and used for through the french revolution and the old regime. This article is not to discuss that, but to delight how another concept deduced from it becomes antagonistic with it in the French context. Laicity referred to the French V constitution, or the act of 1905, it’s not what it appear, and mostly known in the french literature, this article is to reject all that, and go toward an etymological construction of the concept into the french politics since XV century. Then to examination who and how the old regime, and the XIX century have been involved with the religious beliefs then to answer the questions: does the revolution have been laic or atheist? The answer is useful to go forward the examination of the french act of the separation of the State from the churches of 1905, and to determine if that act has been laic or atheist. The questions of how the idea of laicism has been reversed into the interwar period thus to the 1958 constitution to be developed in a further work, but the conclusion proposed here is the evidence of constitutional inter-contradiction and reversed usage of the concept which is being instrumented today further then a constitutional idolatry, but a constitutional nihilism.

In this article we will analyze one of the multiple paths of Marxist criticism and politics, in which the interpretations of the Marxian theory of surplus value intersect with the possibility of a political derivation of its reading. For them, we will address three major moments of this journey, from the popularization of the classical reading of surplus value, to the emergence of divergent readings within the common frameworks of Marxism to, finally, analyze Boris Groys' hypotheses on the subversion of the linguistic order- representation of the capital-labor contradiction.

Since the advent of the so-called Web 2.0 in the 1990s, Social Media has become a key element of election campaigns around the world. However, it has not always been as used and decisive as it is today, it has evolved along with the available technical resources. This article discusses the influence and use of Social Media fore electoral purposes through the last eight U.S. presidential campaigns (1992-2020), as well as their future challenges.