No abstract

The outcome of Life Cycle Assessment (LCA) studies is strongly influenced by the selection of the functional unit, which must be defined in such a way that, when products are compared, the amounts compared have identical utilities. LCA studies of cements mostly use mass based functional units (MFU). However, since different cements have a different composition and binding capacity, they result in different compressive strength and durability in their applications, so that MFUs are inadequate. Therefore, this study introduces as functional unit the Cement Functional Performance (CFP): mass of cement needed to obtain 1 MPa of compressive strength during one year of durability (kg/(MPa•year)). To evaluate the effect of the CFP, the environmental performance of three cements is compared. Results show that adding 5% of zeolite to cement results in a similar strength and 1.78 times higher durability of the produced concrete, which is explained by the reduction of chloride diffusion. Moreover, adding 19% of zeolite to cement increases its durability 2.75 times, but reduces compressive strength by 29%. As a result, cement with 5 and 19% of zeolite added has respectively 54 and 36% of the environmental impacts of Portland cement.

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Damage-induced changes in structure dynamic properties are commonly tracked with time-frequency representations (TFRs). One of the most widely accepted tools for determining a TFR is the continuous wavelet transform (CWT). The success of CWT analysis is highly dependent on selecting the most appropriate values for the parameters that define the mother wavelet. This article presents a detailed analytical and numerical study to select optimal wavelet parameters using the complex Morlet wavelet (CMOR) and the Gabor wavelet. The results obtained suggest that it is possible to define optimal parameter values based on identification target, instantaneous frequency, or average damping ratio. This reduces the computational cost of a reliable CWT analysis when compared with currently employed iterative methodologies based on minimal Shannon entropy criteria.

Resumen Este artículo tiene como objetivo caracterizar la innovación a partir de la evolución que ha tenido en el tiempo, y enfatizando los criterios de medición empleados entre los años 2016 y 2018. En primera instancia, se precisan elementos para la comprensión del fenómeno y sus diferentes acepciones, para luego realizar una revisión comparativa entre fuentes y de propuestas existentes. Se aplicó la minería de datos y el análisis cualitativo de las categorías seleccionadas en el estudio, apoyados en información procedente de bases de datos como Scopus, Web of Science y Scielo. El ejercicio se realizó con el apoyo del Programa de Vigilancia Tecnológica e Inteligencia Competitiva del Centro de Investigación para el Desarrollo y la Innovación de la Universidad Pontificia Bolivariana, complementando con búsquedas particulares. Los principales hallazgos muestran tendencias frente a autores y tipologías de métricas utilizadas en nuestro contexto, lo que permite mostrar la creciente importancia de la innovación social y sus mediciones a nivel de resultados, efectos e impactos, como parte del quehacer científico en el campo social latinoamericano.