Jesús Alba Fernandez

Universitat Politècnica de València | UPV · Department of Applied Physics

Brass instruments mouthpieces have been historically built using metal materials, usually brass. With the auge of additive manufacturing technologies new possibilities have arisen, both for testing alternative designs and for using new materials. This work assesses the use of polymers for manufacturing trombone mouthpieces, specifically PLA and Nyl...

Airflow resistivity is an essential parameter for characterizing air-saturated porous sound-absorbing materials theoretically and selecting sound-absorbing materials in practice. Although standardized methods can determine this non-acoustic parameter in the laboratory, many indirect alternative methods have been proposed to measure it. One of them...

La asignatura Aislamiento Acústico en la Edificación, del Máster en Ingeniería Acústica, de la Escuela Politécnica Superior de Gandia, es punto de control de la Competencia Transversal “Conocimientos de problemas contemporáneos” desde hace seis años. En este trabajo se muestra cómo se ha puesto en marcha utilizando la redacción de informes técnicos...

In building acoustics, two different problems usually arise. There is a need to comply with established sound insulation parameters, but there are also legislative conditions concerning reverberation time. It is therefore necessary to acoustically insulate and condition the enclosures. When designing the acoustic treatment of buildings, sound insul...

Noise pollution has been identified as a cause of a broad spectrum of diseases, motivating researchers to identify building materials capable of attenuating this pollution. The most common solution is the use of gypsum boards, which show a good response for low frequencies but have a poorer response for high frequencies. In addition, due to environ...

The use of membranes attached to sound absorbing materials, with the aim of modifying its absorption properties, is quite a usual practice in acoustic conditioning applications. The behavior of the final composition formed by the sound absorbing base material and the attached membrane can serve to characterize the effect of the membrane, if the pro...

Airflow resistance is a non-acoustic parameter of great relevance in the acoustic characterization of porous materials. It is used in several sound absorbing material prediction models and it is also a control parameter for acoustic conditioning and insulation in different building solutions. The ISO 9053 standard defines several methods to obtain...

The ecological transition is a process the building industry is bound to undertake. This study aimed to develop new bio-based building partition typologies and to determine if they are suitable ecological alternatives to the conventional non-renewable ones used today. This work started with the development of a bio-based epoxy composite board and a...

La asignatura Transductores e Instrumentación Acústica, del Grado en Ingeniería de Sistemas de Telecomunicación, Sonido e Imagen, de la Escuela Politécnica Superior de Gandia, es punto de control de la Competencia Transversal “Aprendizaje Permanente” desde hace cinco años. En este trabajo se muestra cómo se ha puesto en marcha utilizando trabajos t...

Research on sound-absorbing materials made of natural fibers is an emerging area in sustainable materials. In this communication, the use of raw esparto grass as an environmentally friendly sound-absorbing material is explored. Measurements of the normal-incidence sound-absorption coefficient and airflow resistivity of three different types of espa...

The acoustic properties of recycled polyurethane foams are well known. Such foams are used as a part of acoustic solutions in different fields such as building or transport. This paper aims to seek improvements in the sound absorption of these recycled foams when they are combined with fabrics. For this aim, foams have been drilled with cylindrical...

In this paper, a method for measuring the airflow resistivity of air-saturated porous sound-absorbing materials is presented. The method is based on a modification of the previous device developed by Dragonetti et al. The approach used in the present work involves a cavity and a Helmholtz resonator that are coupled through a loudspeaker so that the...

In order to assess the airborne sound insulation of a new material or building solution, access to standardized laboratories, large and expensive facilities, and a sample area of at least 10 m2 are required. At the research and development stages of new sustainable acoustic materials for construction, it is not easy to make large sample areas avail...

Traditionally, glass fibre has been used as plastic reinforcement whenever mechanical properties of a matrix, like stiffness, do not meet the specifications. However, current tendencies try to replace glass fibres by more sustainable fibres to obtain eco-friendlier products. Natural fibres show comparatively good physical and mechanical properties...

The role of acoustics in architectural planning processes is often neglected if the designer lacks necessary experience in acoustics. Moreover, few experiments till the date have brought audio design tools to the classrooms. A basic BLA (Bipolar Laddering Assessment) experiment is presented with architectural degree students showing that sound aspe...

Architectural design process contains a crucial stage called "insight", in which the vital creative phase of the design process begins. Additionally, "design fixation", or simply designing from external stimuli, has been one of the most common methods to approach this phase. Sound as external stimuli for designing, has been used in many historical...

A comparative LCA from cradle to grave between traditional plasterboard, for drywall applications, and different composite boards, made by natural fiber and a bio-based epoxy resin (Supersap CLR), was carried out. The goal of the study was to determine whether the composites based on such a resin combined with natural fibers could be an eco-friendl...

In recent years, natural materials are becoming a valid alternative to traditional sound absorbers due to reduced production costs and environmental protection. This paper reports the acoustical characterization of sheep wool. Measurements on normal incidence and diffuse-incidence sound absorption coefficients of different samples are reported. The...

This paper presents the design, construction, calibration and automation of a reverberation chamber for small samples. A balance has been sought between reducing sample size, to reduce the manufacturing costs of materials, and finding the appropriate volume of the chamber, to obtain reliable values at high and mid frequencies. The small-sized rever...

The use of pyrotechnics near to the historical heritage such as walls, facades, church, or fortifications of a city is nowadays a topic of discussion. There is not a clear legislation about the use of pyrotechnics near to these buildings and how they can be affected by the expansive wave generated by the use of harquebusiers, fireworks, and cannons...

The formulation of greener composite materials by substituting glass fibers with natural fibers is a current field of research. If such natural fiber reinforcements come from industrial side streams, as hemp core fibers (HCFs) come from the extraction of hemp strands for the textile industry, an additional advantage can be identified. Nonetheless,...

Al “Grup d’Innovación Educativa i Recerca en Matèries Científiques (GIERMAC)”, se le concedió en noviembre de 2016 el proyecto PIME-UPV, “Puesta en marcha de diversas experiencias con el enfoche Flip Teaching en asignaturas de Física y matemáticas”, continuación de otro proyecto anterior titulado“Estudio sobre la aplicación del Flip Teaching en asi...

En este trabajo se muestran los primeros pasos que se han llevado a cabo dentro de un proyecto PIME de la convocatoria 2016-2017 del Vicerrectorado de Estudios, Calidad y Acreditación de la Universidad Politécnica de Valencia titulado “Metodologías activas en asignaturas básicas. Creación de un catálogo de demostraciones experimentales o proyectos...

Resumen Utilizar el aprendizaje de manera estratégica, autónoma y flexible, a lo largo de toda la vida, en función del objetivo perseguido es una de las competencias transversales que es punto de control de la asignatura “Transductores e Instrumentación Acústica” de la titulación del Grado en Ingeniería de Sistemas de Telecomunicación, Sonido e Ima...

El aprendizaje permanente es una de las competencias transversales que la Universitat Politécnica de Valencia pretende acreditar. La asignatura “Transductores e Instrumentación Acústica” de la titulación del Grado en Ingeniería de Sistemas de Telecomunicación, Sonido e Imagen es punto de control de dicha competencia. En el curso 2015-2016 se han pu...

La UPV potencia la aplicación de nuevas metodologías docentes, como es el caso del Flipped Teaching o clase inversa, que consiste, a grandes rasgos, en hacer en casa lo que tradicionalmente se hace en el aula (la exposición teórica) y realizar en el aula lo que comúnmente se hace en casa (resolución de problemas). Este planteamiento supone disponer...

Al “Grup d’Innovación Educativa i Recerca en Matèries Científiques (GIERMAC)”, se le ha concedido en octubre de 2015 el proyecto PIME-UPV, “Estudio sobre la aplicación del Flip Teaching en asignaturas de Matemáticas y Física”. El trabajo que se presenta relata una primera experiencia completa realizada con los alumnos de Física del Grado en Ingenie...

Noise, caused by the society and technical progress, is nowadays considered a pollutant. Noise pollution affects or could affect a great number of people. One the most concerned fields, in part by a growing law framework and by the quality expectations of the clients, is architecture. The solution to sound pollution involves eliminating it or reduc...

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 re...

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 alumno...

Most of the analytical models devoted to determine the acoustic properties of a rigid perforated panel consider the acoustic impedance of a single hole and then use the porosity to determine the impedance for the whole panel. However, in the case of not homogeneous hole distribution or more complex configurations this approach is no longer valid. T...

The present paper investigates the acoustic properties of natural fiber reinforced composites. Fibers from orange tree pruning were obtained and subject to different treatments in order to obtain mechanical, thermomechanical and chemi-thermomechanical pulps. These pulps were used as reinforcement for a polypropylene matrix. The obtained composite m...

Recyclable cellulose loose-fill insulation has been commonly used in heavy timber construction for treating attic areas, under floors, and wall cavities. Through the kraft process, the unbleached cellulose adopts a texture characterized by small crumbs, forming a porous medium. In this work, different samples of a single layer of loose-fill cellulo...

En este artículo se muestra cómo un alumno puede abordar problemas de acústica de salas ya en primer curso de Grado, con el soporte de las asignaturas de Matemáticas. De este modo, el alumno, encuentra una aplicabilidad directa de los conociminetos adquiridos en asignaturas en asignaturas de Matemáticas en su futuro entorno laboral. Este proyecto s...

In the present paper, a methodology is proposed for obtaining empirical equations describing the sound absorption characteristics of an absorbing material obtained from natural fibers, specifically from coconut. The method, which was previously applied to other materials, requires performing measurements of air-flow resistivity and of acoustic impe...

The statistical or random-incidence sound absorption coefficient is the most important pa-rameter to characterize a porous sound absorbing material in practice. According to the ISO standardized procedure this parameter can be measured directly in reverberation chambers where a perfect diffuse sound field is attained. Basically, the procedure compa...

Although the study of the sound pressure radiation from membranes and plates is not new, current and future applications have produced a large body of recent research in the field. Several works have been published on the radiation from general plane surfaces and some particular geometries such as rectangular, circular, elliptic and annular. Howeve...

It is well known that sound absorption and sound transmission properties of open porous materials are highly dependent on their airflow resistance values. Low values of airflow resistance indicate little resistance for air streaming through the porous material and high values are a sign that most of the pores inside the material are closed. The lab...

Characterization of sound‐absorbing materials is one of the investigation fields that is acquiring most interest in the last few years. As a consequence, there is an increase in investigators who are trying to obtain mathematical models to predict the acoustical behavior of the materials, as well as those who are looking for new materials to improv...

The capacity and computing power of programs like Matlab enables first year students of a college degree are able to model using the computer both topographic maps and roads on them, as acoustic maps. In other words, moving from paper to digital model. This article shows several collaborative works made over many years by Gandia Campus students of...

The main contribution of this paper is the formulation of an alternative to experimental determination of loss factor and, consequently, to improve the predictions of airborne sound insulation for any type of monolithic or laminated glass. In addition, a review of the standards related to measurement of mechanical parameters of glass is carried out...

Currently, acoustic isolation is one of the problems raised with building construction in Spain. The publication of the Basic Document for the protection against noise of the Technical Building Code has increased the demand of comfort for citizens. This has created the need to seek new composite materials that meet the new required acoustical build...

Resumen La evaluación del ruido transmitido por flancos en edificación es esencial para el estudio del aislamiento a ruido aéreo. Desde el punto de vista numérico, para la determinación de las transmisiones laterales es necesario conocer un parámetro conocido como índice de reducción vibracional. Para obtener este parámetro con el objetivo de conoc...

Polyurethane foam waste is one of the residues of the manufacturing processes in textile industry, the disposal of which is becoming a severe environmental problem. In this paper the sound absorption properties of different materials developed from ground polyurethane foam waste are studied. Because these recycled materials exhibit good sound absor...

El aislamiento acústico es un problema de difícil solución una vez que la obra ya está acabada. En el caso de que la obra esté finalizada y no se cumplan con los valores de calidad acústicos que nos marca la legislación, deben detectarse los puntos débiles que provocan esa deficiencia de aislamiento acústico. La publicación de catálogos de solucion...

This paper describes the procedure followed to evaluate the vibration reduction index for T-junctions with inserted flexible elements and proposes new equations to complement the standard EN 12354-1:2000. The experiment described in this work is based on a 1:3 scale model of a T-junction with a flexible interlayer. It was used to obtain a significa...

A poor sound insulation of building elements that constitute a building has a difficult solution when the building is finished. If we have a finished building in which not reached the minimum values of sound quality that marks the relevant legislation, we must be able to detect weaknesses that cause gaps in the sound insulation. The publication of...

Resumen La obtención de la presión radiada por superficies planas no es un problema nuevo. Es un problema que está en estudio por la complejidad del tema y por su aplicación al diseño de altavoces planos. Estos son cada vez más comunes en televisores, techos, pantallas de cine, paneles, etc. En estos casos predomina sobre todo la forma rectangular....

The present paper addresses the analysis of structural vibration transmission in the presence of struc- tural joints. The problem is tackled from a numerical point of view, analyzing some scenarios by using finite element models. The numerical results obtained making use of this process are then compared with those evaluated using the EN 12354 stan...

The first activities related to acoustic detection of particles by DISAO research group in the Univesitat Politècnica de València are described. We are applying some techniques from physic, engineering and oceanographic acoustics to face the high energy neutrino underwater acoustic detection challenge. The work is focused mainly in two topics: desi...

In the building acoustics field usually fibrous materials are used as sound absorbing materials. Nowadays polyester fiber is one of the most used but the pure chip of polyester has a problem. Polyester is obtained of petroleum and its price was increasing last years. This paper, presents an alternative polyester wool which obtained by PET treatment...

Berm mounds are a commonly used technique to reduce the environmental noise levels produced by highways. A berm is a natural noise barrier constructed of soil, stone, rock, or rubble, often landscaped, running along a highway to protect adjacent communities from noise pollution. An earth mound may be constructed using surplus materials at project s...

Characterization of sound absorbing materials is essential to predict its acoustic behaviour. The most commonly used models to do so consider the flow resistivity, porosity, and average fibre diameter as parameters to determine the acoustic impedance and sound absorbing coefficient. Besides direct experimental techniques, numerical approaches appea...

Evaluation of the Simrad EY-500 echosounder for the population control of gilthead seabream Sparus auratus Linnaeus, 1758 cages. The use of the Simrad EY-500 echosounder in the field of marine aquaculture, particularly in the control of gilthead seabream Sparus auratus Linnaeus, 1758 populations, is evaluated. As a first approach to the problem, th...

Foams are widely used as sound absorbing materials in noise control engineering. These sound absorbing materials are used to control the noise and vibration in many mechanical systems, including industrial machines, home appliances, vehicles, and buildings. A foam material is a solid that contains cavities, channels or interstices so that the sound...

Porous materials are widely used as sound absorbing materials in noise control engineering. In view of the growing interest in sustainable construction a new field involves the creation of the acoustic absorbents using recycled material based on industrial residues or derived from plants. Some authors already have models of prediction for this type...

Several alternatives to mitigate road traffic noise impact have been reported, although constructing a noise barrier is probably the most important mitigation measure when the construction of a highway is planned. A noise barrier impedes the transmission of traffic noise, resulting in low noise levels at the receiving point. Earth-mounds, fences, o...

Characterization of sound absorbing materials is needed to predict its behavior. The most commonly used models to do so consider the flow resistivity, porosity, and average fiber diameter as parameters to determine the acoustic impedance and sound absorbing coefficient. Besides direct experimental techniques, numerical approaches appear to be an al...

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 pr...

One of the main corrective measures taken to reduce environmental noise produced by roads is using sound barriers. However, the construction of miles of noise barriers implies a high cost. One solution to reduce the costs is using recycled materials in the noise barriers, for example, plastic wastes, which has great environmental benefits. Accordin...

In controlling environmental noise, a lot of effort is put in place to optimize noise barriers. However, in doing so, the noise barriers are usually made of materials that are difficult to recycle. Currently, several studies are aimed to use textile-based materials, such as polyester wool instead of mineral wool, in manufacturing noise barriers. Ho...

Acoustic Standards in the building are responsible for, companies and individuals, propose new acoustic materials for the sound isolation. This paper presents a new sound-absorbent material, it is based on natural fibres, particularly fibres of kenaf. It also proposes an empirical model for this material, this models depends on the frequency. There...

Acoustic Standards in the building are responsible for, companies and individuals, propose new acoustic materials for the sound isolation. This paper presents a new sound-absorbent material, it is based on natural fibres, particularly fibres of kenaf. It also proposes an empirical model for this material, this models depends on the frequency. There...

In this work we present some results of an experimental study carried out to determine the vibratory response of a structure of concrete. This structure has a soil of 10 cm of thickness. On this base, four vertical elements rise forming a cross centered with the slab, thus the space is divided in four equal parts. Two types of excitation have been...

This paper presents the use of the finite elements method to study the flanking transmission through the use of the vibration reduction index, for the case of constructive solutions that use floating floors. On one side, the insertion of elastic interlayer in new building solutions is now a very common practice. On the other side, the test procedur...

In this work we propose a methodology to characterize laminated glass, and, this way like to predict the acoustic isolation of this type of constructive elements. Taking as starting point the measures of function of transfer acceleration-force for monolithic bars of glass and of laminated glass, there is applied a numerical inverse method to determ...