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RESUMENEste trabajo presenta un modelo multiobjetivo no lineal entero mixto (MINLP) para el diseño sostenible de cadenas de suministro para el reciclaje de varios materiales. En él se integran objetivos económicos y medioambientales para soportar la toma de decisiones estratégicas y tácticas tales como la localización de instalaciones, el diseño de los flujos materiales y la selección de medios de transporte. La evaluación del impacto medioambiental se realiza a través de la metodología de Análisis del Ciclo de Vida (LCA) utilizando el Ecoindicador 99. Se modeló un caso de estudio para la cadena de reciclaje de dos tipos de plástico, utilizando el método de las restricciones para obtener la frontera de Pareto. En el desarrollo del caso se mostraron indicadores que permiten evaluar las soluciones encontradas y así facilitar el proceso de toma de decisiones.Palabras clave: diseño de la cadena de suministros, logística inversa, modelo de optimización, sostenibilidad. ABSTRACT This paper presents a multi-objective mixed integer non-linear problem (MINLP) to

The present work shows the fractal analysis for the microstructure of Al-6Si-3Cu-xMg (x = 0.59, 3.80 and 6.78 wt.%) alloys, solution heat treated at 480 °C for times ranging from 4 to 72 h. Microstructural changes were examined using Optical Microscopy (OM) and Scanning Electron Microscopy (SEM), and quantified by measuring conventional characteristics of second phases. The fractal analysis of the microstructures was also carried out using fractal dimension (D f ). Results shown important variations in the microstructure when Mg content is increased, being the eutectic Al-Si and Cu-rich phases the predominant phases for the alloys with low Mg content, while for higher Mg contents predominant phases were Mg 2 Si and Cu-rich phases. The analysis of D f showed that this parameter could be used in order to compare the microstructural solution response of the Al alloys. Besides, it was possible to correlate the fractal dimension with the shape factor of the second phases, mainly for the alloys with only one second phase remaining after heat treatment.

In this paper, the inverse problem of reconstructing reflectivity function of a medium is examined within a blind deconvolution framework. The ultrasound pulse is estimated using higher-order statistics, and Wiener filter is used to obtain the ultrasonic reflectivity function through wavelet-based models. A new approach to the parameter estimation of the inverse filtering step is proposed in the nondestructive evaluation field, which is based on the theory of Fourier-Wavelet regularized deconvolution (ForWaRD). This new approach can be viewed as a solution to the open problem of adaptation of the ForWaRD framework to perform the convolution kernel estimation and deconvolution interdependently. The results indicate stable solutions of the estimated pulse and an improvement in the radio-frequency (RF) signal taking into account its signal-to-noise ratio (SNR) and axial resolution. Simulations and experiments showed that the proposed approach can provide robust and optimal estimates of the reflectivity function.

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