Cuadernos de Ingeniería

Endomorphisms in R2 : change of basis and ways of thinking in Linear Algebra

2024-11-08T13:48:03-03:00

The objective of this research work was to contribute to the understanding of the Base Change in Endomorphisms of R², through the implementation of the theory of modes of thinking: Synthetic-Geometric, Analytical-Arithmetic and Analytical-Structural proposed by Anna Sierpinska (2000) and induced by the Geometric, Arithmetic and Algebraic languages. For this, didactic activities were designed where these languages are articulated that allow the transition between the different modes of thinking about the change of base in endomorphisms of R². A quantitative approach with posttest only was used. Two groups were randomly selected: the experimental and the control. For the purpose of evaluating the design, the post-test was implemented in both groups. In the experimental group a greater mastery of the subject of study was demonstrated, which resulted in a more solid geometric interpretation in R², as well as a precise use of definition and properties, with very good performance in the manipulation of matrices associated with endomorphism in different bases. On the other hand, the students of the control group will not be able to establish a connection between the modes of thinking, which had an impact on the understanding of the subject under study.

Seismic action directionality effect analysis of a reduced-scale model of buildings

2024-11-08T14:37:25-03:00

Directionality analysis makes it possible to evaluate the influence of the angle of incidence of seismic action on structures. In this work, a small-scale model (metal structure) representative of the typical buildings of the city of Barcelona was used. The numerical analysis was performed with the ETABS software, using moment of inertia modifiers at the ends of the beams until the dynamic parameters resemble those obtained with the experimental model. Three case studies were established: one corresponding to the original structure (without damage) and two others each corresponding to a model with damage on a longitudinal face and on a transverse face. Directionality was applied with the horizontal components of the earthquake accelerogram recorded in Lorca that occurred in 2011. The parameters to be analysed were the displacement in a node of the upper level of the building and the basal shear force. For different damage situations, the same building shows different behaviour, varying depending on the earthquake incidence angle. The displacement obtained for some angles is greater than the one of the initial angle. The value of the maximum basal shear force differs for different cases, being higher in cases with damage and almost independent of rotation in the case without damage.

Nonlinear diffusion problems. Existence and uniqueness of the solution

2024-12-12T15:02:53-03:00

The elliptic type differential equation is the mathematical model for steady-state diffusion problems. In certain engineering cases, the diffusion coefficient may not be constant, for example, depending on concentration or temperature. This leads to nonlinear boundary value problems whose analytical solution is generally complex and very laborious to obtain. On the other hand, the most important thing before addressing the resolution of this type of problem is to determine the existence of the solution and, in that case, the conditions under which its uniqueness can be ensured. In the present work, starting from the weak formulation of the boundary value problem, the theoretical basis of the finite element method, and useful for its implementation in computers, the continuity and coercivity of the nonlinear form associated with the boundary value problem are demonstrated. With these results, the Sobolev space to which the solution belongs is established, and the conditions for the existence and uniqueness of the solution are determined. Finally, the numerical results obtained using the finite element method are validated by comparing them with solutions available in the literature.

Analysis of Gutenberg-Richter b-value and mmax Part IV: New technique to estimate the parameters mmax, mmin and b-value

2025-04-28T13:21:56-03:00

In this paper, we carried out an analysis of the Gutenberg-Richer distribution function, which gives a new technique to estimate the expected values. This estimator, which we referred to as expected value curve estimator, gives a relationship between the Order Statistic and the Maximum Statistic. Also, it was observed that the sample size is unknown parameter in the real seismic catalogs. In addition, we show an algebraic solution for the Gutenberg-Richter distribution problem, where all the unknown parameters , and are estimated using four estimators of the expected values. We also discuss the role of the negative b-value.

The 2030 Agenda and addressing the SDGs. Its application in the Reconquista River Basin Committee. Province of Buenos Aires. Argentina

2025-05-05T13:17:21-03:00

The study focuses on the alignment of the Reconquista River Sanitation Program (Loan BID 3256/OC-AR), with the Sustainable Development Goals of the 2030 Agenda. Although the actions carried out by the Reconquista River Basin Committee contribute significantly to these objectives, a lack of documentation and recognition of its impact on the SDGs is identified. The analysis included a background review, search for government commitments and identification of projects financed by the IDB, which were categorized according to the dimensions of the SDGs.

A relationship matrix was developed and validated in order to improve accountability to national and international organizations. The relationship matrix made it possible to visualize what actions are being carried out regarding SDGs and which objectives are being worked on more or are being postponed; From there, evaluate whether the actions carried out are actually conducive to the priorities of the institution.

It was recognized that global indicators are not suitable to be applied at a regional (watershed) scale. The development of own indicators that could be developed and applied by the institution's technicians was suggested.