Romina del Rey Tormos

Acoustic characterization of recycled textile materials used as core elements in noise barriers

Studies on new acoustic eco-materials are gaining importance as there is an increasing understanding about the benefits of the use of environmentally friendly materials. In producing noise control elements it is not only important to recycle but also to manufacture devices with recycled content. A noise barrier is one of the most used devices to reduce high noise levels. For designing these devices, a sound absorbing material is very often used as the core of the barrier. The main goal of this work is the design and testing of novel green sound absorbingmaterials used as part of noise barriers. Recycled textile materials and nontoxic binder fibers were employed to manufacture the eco-materials studied in this research. Acoustic characterization of prototype noise barriers was carried out in a customdesigned small-scale reverberation chamber for the testing of small samples. Results showed that new materials used in noise barrier prototypes performed very well according to international standards, with performance comparable with those of commercially available noise barriers made of typical sound absorbing materials. These new materials could be part of noise reducing devices incorporating an environmentally conscious technology.

Effect of the estimation of the wall/floor junction type on the acoustic isolation

Deviations between the laboratory measurement and the final in situ measurement, are common in the acoustic isolation. A fundamental difference between both cases is the effect of the lateral flanks. This effect produce that the global acoustic insulation changes substantially. With the standard UNE‐EN‐12354‐1, it can be estimated the effect of the flank, obtaining the vibration reduction indexes and evaluating the insulation of every way. It is also possible to carried out a measurement procedure with the Standard ISO 10848, in it the index is measured and then the index is calculated. This paper shows the differences of results of airborne sound insulation and impact insulation with in situ measurements of the vibration reduction index and the different estimations that the Standard allow. Different unions are studied, and the influence of these in the global result of the insulation is evaluated.

Aplicando Flipped Teaching en Física del Grado en Ingenieria de Sistemas de Telecomunicación, Sonido e Imagen

Este trabajo se ha realizado gracias al apoyo del Vicerrectorado de Estudios, Calidad y Acreditacion de la UPV al Proyecto PIME 2016-2017 “Puesta en marcha de diversas experiencias con el enfoque Flipped Teaching en asignaturas de Matematicas y Fisica”.

Flipped Teaching en Física del Grado en Ingenieria de Sistemas de Telecomunicación, Sonido e Imagen: primeros resultados

Al “Grup d’Innovacion Educativa i Recerca en Materies Cientifiques (GIERMAC)”, se le ha concedido en octubre de 2015 el proyecto PIME-UPV, “Estudio sobre la aplicacion del Flip Teaching en asignaturas de Matematicas y Fisica”. El trabajo que se presenta relata una primera experiencia completa realizada con los alumnos de Fisica del Grado en Ingenieria de Sistemas de Telecomunicacion, Sonido e Imagen (GISTSI) durante los meses de noviembre y diciembre de 2015. En esta experiencia los alumnos se presentan de forma voluntaria a esta estrategia y son compensados con puntos adicionales por el esfuerzo. La experiencia esta centrada en temas de termodinamica, por lo que sera exportable a asignaturas de otras titulaciones que la impartan.

Aprendizaje basado en proyectos: Primera experiencia en la asignatura de Física del Grado en Ingeniería de Telecomunicación, Sonido e Imagen.

Esta comunicacion trata sobre la prueba de aplicacion del aprendizaje basado en proyectos en la asignatura de Fisica del Grado en Ingenieria de Telecomunicacion, Sonido e Imagen. Se realiza esta primera experiencia donde el ultimo bloque tematico dedicado al campo magnetico y a la induccion magnetica se articula en forma de proyectos que los alumnos eligen de forma voluntaria. En la comunicacion se resumen como se ha articulo esta metodologia activa, desde el contexto, objetivos, preguntas motrices, enunciado, planificacion, tipos de actividades, interdependencia, valoracion y conclusiones.

Detección de puntos débiles de aislamiento acústico en edificación ya construida

Este trabajo ha sido financiado por el Ministerio de Educacion y Ciencia. DG RESEARCH (BIA2007-C02-01 y BIA2007-C02-02) y por el Ministerio de Ciencia e Innovacion (BIA2010-17723).

Nuevos materiales absorbentes acústicos basados en fibra de kenaf

This project has been funded by the Ministry of Education and Science. DG Research (BIA2007-C02-01 y BIA2007-C02-02).

A simple empirical model for recycled polyurethane foams for acoustical applications.

In this work, the acoustic behavior of recycled polyurethane foams is studied in the frequency domain. Other authors have described the behavior of porous materials based either on the flow resistance [Dunn & Davern] or the structural characteristics of the pores [Voronina]. The main objective of all these works has been the determination of the propagating constant and the characteristic impedance. Here, the propagating constant and the characteristic impedance are described as a function of the flow resistance. The flow resistance has been obtained from experimental measurements using the method proposed by Ingard & Dear. On the other hand, the normal incidence sound absorption coefficient values are obtained using the procedure described in the standard UNE‐EN ISO 10534‐2:2002. In this way, specific coefficients for recycled polyurethane foams are determined. These coefficients are later compared with the classical coefficients that describe the behavior of any open‐pore material.

Study in the measurement of noise air insulation in laboratory of the effect in the diffuse field

We can obtain, in a transmission chamber, the air transmitted noise insulation. In the standard 140‐1 the characteristics of these chambers are described. One of these characteristics tries to ensure diffuse field inside these chambers. Nevertheless, we cannot assure an incident angle between 0° and 90° on the test wall, there is a limit angle lower than 90°. In this paper, we study the valuation of the committed mistake by limit angle in transmission chambers. Expressions used for calculating the insulation in transmission chambers are obtained from transmission description in diffuse field, in which case the angle is 90°. In this work, for different materials commonly used in transmission chambers tests, the influence of the indetermination of a mistake and the global mistake evolution with limit angle is studied.

Determination of unknown parameters in impervious layers by inverse method

In this work, a novel procedure is shown for the determination of unknown parameters in impervious layers used in multilayer structures by inverse method and using scale models. Experimental pressure and velocity data are obtained by Nearfield Acoustic Holography (NAH) for the calculation of the transmission loss of the different multilayer structures mounted on the window of a wooden box designed for that end. These data are used as input data in the inverse method. The forecast model of acoustic insulation in multilayered structures used in this work was Trochidis&Kalaroutis model based on Spatial Fourier Transform (SFT). By applying Trochidis&Kalaroutis model and adjusting by numerical methods the variables that define the impervious layers of the system, the values of the unknown magnitudes of the layers are calculated. For validation purposes the results are compared to those obtained with Ookura&Saito model.