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

This research proposes a reconfigurable photovoltaic cell model and a research platform in solar conversion optimization. The solar park concept has its main objective in scientific field research. That is why it is a space for the analysis of technologies; the model proposed here is based on a reconfigurable scheme, with converter concatenation and feedback, within the framework of regenerative systems. Criteria were established for the configuration of IPVDs intelligent photovoltaic devices, supported by FPGA technology. An intelligent arrangement of solar panels, distributed in the solar field, perform the formulation of the tandem composition and synthesis of reconfigurable structures. Artificial neural networks have been applied, in their specific functions of dynamic modeling, advanced control and reconfigurable schemes. As a result, the conceptual design of the platform is obtained under criteria of sustainability and environmental responsibility, a matrix of codes for the remote configuration of the elements and a model with LFSR architecture for the renewable energy converter system. All this allows us to contribute to the migration towards new technologies and sustainable models of the energy matrix, with online estimation of the environmental impact and efficiency of the new developments. A technological concept is obtained as a conclusion, which is based on a fractal model from quantum physics applied to the design of the photovoltaic converter, to the generalized structure, with the ability to reconfigure the characteristics of its layers.

Common bean is one of the most consumed crops worldwide, and of great importance for food security in Central America. The aim of this study was to determine the speed in which Matambú bean (Phaseolus vulgaris) expands after grain soaking. An automated digital image processing pipeline for measuring individual grain volume and simultaneously retaining its integrity was validated and used. Volumetric expansion was evaluated with Peleg and sigmoid models for water temperatures of 20-70 oC.The equations kinetic parameters weredescribed as functions of temperature using the Arrhenius equation with an activation energy of 22.410kJ mol-1. The obtained results are potentially useful for future studies on food properties, process and packaging design.

In Peru there is a growing demand to improve, expand or remodel existing infrastructure, which has generally been designed with structural standards less demanding than the current ones. It is for this reason that various techniques are used, such as reinforcement using FRP (fiber reinforced polymer) systems. Among the predominant applications of this system is the reinforcement to bending of reinforced concrete (RC) elements such as walls, slabs and especially the beams. During the application of the FRP, various interferences or constructive limitations could occur, which has led to the approach of practical and modern solutions such as the use of FRP band systems, FRP plates and bars, NSM systems, and the use of anchors made of FRP. These procedures are contemplated in the ACI's guide 440.2R (ACI, 2017), used for the construction and design of external reinforcement with FRP on RC elements. The purpose of this article is to show the results on the laboratory experience of four RC beams, considering that only three of them were externally strengthened to bending, a solution with anchors made of FRP was also used, in order to allow the tensile behavior of the FRP external reinforcement. The specimens tested were subjected to cyclic loads by a quasi-static test, and the results indicate that these elements strengthened with FRP bands and anchors have a resistance capacity greater than the nominal flexural capacity. In addition, the behavior exhibited throughout these tests was stable and without unexpected anomalies that have been observed.

This experiment evaluates the effect of the spatial position on the power of a 5W LED which was obtained using a radiometer. For this purpose, the radiant flow emitted by the LED was arranged, taken at different positioning angles and the distance from it from the sensing equipment. Statistical analysis for the validation of the obtained data was checked against the values provided by the manufacturer according to the specification sheet. Finally, the increase in tilt angle and distance resulted in a loss of radiant flow emitted by the LED by 99%.

A preview of the San José canton exposure model to be used in seismic risk assessments, consisting in the structural characterization and spatial distribution of buildings inside the canton is presented. For it generation, a sample of 1 856 buildings, selected by means of a stratified random sampling with proportional allocation was used, following the Rapid Environmental Mapping method, developed by GFZ. Among the main results found was that 50% of the buildings from the sample are classified as confined reinforced masonry with rigid diaphragm and 40% with flexible diaphragm, also the most used lateral load resisting system is the wall type (92%).

Through an optimization algorithm, the behavior of intelligent electrical management based on the multiagent combination of storage and alternative energy is shown. The control algorithm is conceived altogether with the optimization and the energy flow of a residence. With real consumption and expected generation data, the optimization sets a savings limit of 93% compared to a traditional system without electrical management. According to the energy flow and under the same optimization conditions, the operation of the algorithm is verified and the results approach the limit and achieve savings of 86%.

The Discontinuous Conduction Mode analysis of the new 1-FB-1 DC/DC converter is proposed. The mode boundary is established for the designer to appropriately define the continuous o discontinuous operation.  The analysis comprehends the converter inductor current and output voltage waveforms, and their analytical expressions.

Explanatory note regarding the licensing of documents published in Engineering: Journal of the University of Costa Rica

This work has as main objective to present a methodological construction process that can be described as interdisciplinary. It is intended to go through the process whereby the initial methodological research questions and choices, constructed from a disciplinary logic, were linked to methodological tools from other disciplines. Presenting the first steps of this unfinished process, it is also intended to highlight the coincidences between methodological lines that have been developed by various social scientists, in which an operation or an investigative attitude described as “tracking” is claimed, which can be considered a bridge methodological between disciplinary lines of research. This exploration is illustrated by presenting the first results of an ongoing investigation, whose theme is the historical evolution of the links between water and city in San Fernando del Valle de Catamarca (Catamarca, Argentina). Next, some challenges and possible indications are rescued to continue complexing the theoretical-methodological construction proposed.

The article aims to illuminate the contributions of contrast-oriented method from an investigation on the transformations of working-class participation in the suburbs of Paris and Buenos Aires (1930-2010). The first part sets out the framework of the comparison and the construction of the object of the investigation. The second part gives an account of the analysis of the similarities and differences in the forms of working-class sociability in both industrial suburbs (1930-1970). The third part illustrates the contribution of the comparison to analyse the increase of grassroots participation of the working-class in relation with the disaggregation of industrial society (1970-2010). The conclusion underlines the benefits of the method of contrast-oriented comparison to the researcher's reflexivity and creativity.