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

La evapotranspiración es uno de los procesos del ciclo hidrológico de mayor relevancia en estudios de balance y disponibilidad de agua en las áreas agrícolas de la región árida del Noroeste de México. En este trabajo, se utilizaron imágenes del Índice de Vegetación de la Diferencia Normalizada (NDVI) obtenidas a partir del sistema satelital PROBA-V para elaborar un modelo y estimar la evapotranspiración (ET) de un cultivo de sandía en la zona agrícola de la Costa de Hermosillo, Sonora. El procedimiento se basó en la correlación entre el coef iciente de cultivo (Kc) y el valor del NDVI. Con el modelo se estimó la ET para el cultivo de sandía, los resultados se contrastaron con valores de ET medidos con el método de covarianza de vórtices. La correlación entre los valores medidos y los estimados fue de r2 = 0.729 y, aunque los resultados fueron aceptables, pueden ser mejorados a medida que se incremente el número de imágenes satelitales de buena calidad y la ET sea medida en una mayor variedad de cultivos.

En un transformador de fuerza (TF) de una central termoeléctrica (CTE) cubana, empleando la termografía infrarroja y el Análisis de Gases Disueltos en el aceite (AGD), se detectaron indicios de fallas en el aislamiento sólido.  El trabajo trata sobre los TF, su sistema de aislamiento, la relación mantenimiento-diagnóstico; se brindan datos del TF estudiado, sus funciones estándares y el estado de su diagnóstico; se abordan las técnicas de ensayo y se aplican en el TF estudiado. Se propone la matriz de mantenimiento y diagnóstico del TF. Se realiza un análisis de factibilidad y sostenibilidad de las tareas de diagnóstico y se propone un sistema de monitoreo y diagnóstico para el TF, que permitirá la detección temprana y el seguimiento de las posibles fallas en su sistema de aislamiento sólido, para de esa forma contribuir a mejorar el sistema de mantenimiento establecido para el equipo, o a tomar la decisión de adquirir en su lugar un equipo nuevo.

Context: Is achieved a research through Principal Component Analysis (PCA) for determining the variability and climate patterns of two important cities in the Colombia Caribbean.Method: This research used satellite data with three hourly resolution contained in a 35 year data set (1980 to 2014), and a spatial scaling was performed using information related to Cartagena and Barranquilla cities, located in the north of Colombia.Results:  The correlation results, above 80 %, show an appropriate adjustment for the information analysis of wind speed and temperature. Time lag matrixes were built for the time series with the aim of applying the Principal Component Analysis (PCA), known as Singular Spectrum Analysis. The main components were identified, which represent more than 70% of the temperature and the wind data in both cities.  A  Fourier analysis for the wind speed and the temperature allowed identifying similar oscillation modes (main components) detected by the PCA.Conclusions: Sea and land breezes explain the identified diurnal temperature and wind speed variability in Cartagena. Additionally were observe a quarterly variability associated with fluctuations Maden Julian, semiannual, annual, and 6-year variability associated with ENSO. Finally, the cluster analysis allowed the identification of two-climate pattern in the study area.

Objective: This paper proposes a method to analyze the technical, commercial and social feasibility of software projects in environments of uncertainty. It allows working with multiple experts and multiple criteria and facilitates decision-making.Method: The proposal contains two phases, first the necessary information is collected and in second place projects are evaluated using 2-tuple linguistic representation model. The experts are selected by analyzing their curricular synthesis. The evaluation criteria are defined using the technique Focus Group and weighted in the interval (0,1) according to their importance. three domains are offered to express the preferences: numeric, interval-valued and linguistic. For aggregation extended arithmetic mean and weighted average extended are used, preventing the loss of information. A 2-tuple (feasibility, precision) is obtained as a result for each project.Results: The evaluation of P1 project was a very high feasibility with -0,33 of precision. The P2 project obtained a high feasibility with 0,38 of precision and P3 project achieved a medium feasibility with -0,21 of precision.Conclusions: This method is favorable for software projects feasibility analysis with presence of multiple experts and criteria, in environments of uncertainty. It tries heterogeneous assessments without loss of information. Their results are consistent and useful for decision makers.

Context: The use of construction and demolition waste - CDW, is part of the management that allows us to mitigate environmental pollution and reduces the impact caused by the extraction of natural aggregates. The sector of construction industry has launched aims of implementation of “3R - reduce, reuse and recycle” methodology and “Cleaner production” for the CDW processes; being in Colombia, a sector with annual growth of 13%, which increases the available.Method: It was required to establish a comparative particle size analysis between aggregate natural and recycled, which allowed to identify from the technical point of view, similarities and differences between parameters established in the Colombian technique standard NTC 174 (specifications for aggregates in concrete production). Samples of recycled aggregates were taken from artisanal dumps of Bogotá D.C.; and samples of natural aggregates, obtained from the commercial sector in the city.Results: We obtained grain size curves of the aggregates regarding the limits set by the standard NTC 176. Achieving determines that the CDW do not comply with the normative specifications of the concrete. However it is possible to use as aggregate for concrete structural, no sustainable modular manufacturing.Conclusions: It is needed an assessment and grading comparison of the aggregates to establish that the residuals are reused as raw material: promoting an environmental policy that suggests use as a sustainability strategy in social settings.

Context: Many technological applications are including haptic devices, which send to the user haptic feedback that is traduced to a sensation. This work shows the construction of a type of these devices.Method: This work shows the design and construction of a haptic device of six degrees of independent movement with its force feedback.Results: It was obtained a haptic device of six degrees of freedom that allows the movement of a cursor on a virtual environment formed by a cube in the PC. The haptic device sends to the user a force feedback when the cursor touches any side of the virtual cube.Conclusions: The built haptic device provides a suitable haptic sensation into the virtual environment. This device will be able to test and use in many advanced perception projects.