Research of the acoustic phenomenon produced by isolated scatterers and its applicability as a noise reducing device in transport infrastructures. Search for an optimised and sustainable design.

Tesis por compendio[ES] El control de ruido ambiental es una preocupación de primera magnitud para las sociedades avanzadas, debido a los problemas derivados que ocasionan en la salud de los ciudadanos. Una de las soluciones más extendidas para el control del ruido en su fase de transmisión en la utilización de pantallas acústicas. La aparición de nuevos materiales formados por redes de dispersores acústicos aislados, denominados cristales de sonido, está revolucionando el campo del apantallamiento acústico, posibilitando el avance tecnológico de esta área. Así, en los últimos años, las pantallas acústicas basadas en cristales de sonido se han posicionado como una alternativa viable a las pantallas acústicas tradicionales, puesto que ofrecen múltiples ventajas frente a las soluciones actuales. En el presente trabajo se muestra primeramente una recopilación de los avances realizados en el campo del apantallamiento acústico mediante esta tipología de pantallas. No obstante, aún existen líneas de investigación abiertas en esta área, que es necesario abordar para conseguir el objetivo de aplicar esta tecnología como atenuadores de sonido en las infraestructuras de transporte. Durante el periodo de formación de la doctoranda, se ha trabajado en algunas de las líneas de investigación activas en este campo del apantallamiento acústico. Una de estas investigaciones condujo al descubrimiento de interferencias entre los efectos de la resonancia y la dispersión múltiple de los cristales de sonido cuando estos efectos se producen en rangos de frecuencia cercanos. También hemos diseñado un nuevo dispositivo de reducción de ruido basado en cristales de sonido, utilizando herramientas de optimización multiobjetivo, que permitan apantallar y reflejar de forma difusa el ruido. El empleo de esta nueva herramienta de diseño identificó la necesidad de realizar un estudio comparativo de los métodos de simulación más utilizados para estimar el rendimiento de los dispositivos basados en cristales de sonido. Por último, hemos realizado un estudio psicoacústico para determinar la percepción de la reducción de molestia que proporcionan las pantallas acústicas basadas en cristales sonido y las barreras tradicionales, determinando si los parámetros objetivos que evalúan su rendimiento coinciden con la respuesta subjetiva de los usuarios.[CA] El control de soroll ambiental és una preocupació de primera magnitud per a les societats avançades, a causa dels problemes derivats que ocasionen en la salut dels ciutadans. Una de les solucions més esteses per al control del soroll en la seua fase de transmissió en la utilització de pantalles acústiques. L'aparició de nous materials formats per xarxes de dispersors acústics aïllats, denominats cristals de so, està revolucionant el camp de l'apantallament acústic, possibilitant l'avanç tecnològic d'esta àrea. Així, en els últims anys, les pantalles acústiques basades en cristals de so s'han posicionat com una alternativa viable a les pantalles acústiques tradicionals, ja que oferixen múltiples avantatges enfront de les solucions actuals. En el present treball es mostra primerament una recopilació dels avanços realitzats en el camp de l'apantallament acústic per mitjà d'esta tipologia de pantalles. No obstant això, encara hi ha línies d'investigació obertes en esta àrea, que és necessari abordar per a aconseguir l'objectiu d'aplicar esta tecnologia com a atenuadors de so en les infraestructures de transport. Durant el període de formació de la doctoranda, s'ha treballat en algunes de les línies d'investigació actives en este camp de l'apantallament acústic. Una d'estes investigacions va conduir al descobriment d'interferències entre els efectes de la ressonància i la dispersió múltiple dels cristals de so quan estos efectes es produïxen en rangs de freqüència pròxims. També hem dissenyat un nou dispositiu de reducció de soroll basat en cristals de so, utilitzant ferramentes d'optimització multiobjectiu, que permeten apantallar i reflectir de forma difusa el soroll. L'ús d'esta nova ferramenta de disseny va identificar la necessitat de realitzar un estudi comparatiu dels mètodes de simulació més utilitzats per a estimar el rendiment dels dispositius basats en cristals de so. Finalment, hem realitzat un estudi psicoacústic per a determinar la percepció de la reducció de molèstia que proporcionen les pantalles acústiques basades en cristals so i les barreres tradicionals, determinant si els paràmetres objectius que avaluen el seu rendiment coincidixen amb la resposta subjectiva dels usuaris.[EN] Control of environmental noise is a major concern for advanced societies because of the resulting problems for citizens' health. One of the most widespread solutions for controlling noise in its transmission phase is the use of acoustic screens. The emergence of new materials made up of arrays of isolated acoustic scatterers, called sonic crystals, is revolutionizing the field of acoustic screening. In recent years, acoustic screens based on sonic crystals have positioned themselves as a viable alternative to traditional acoustic screens, as they offer multiple advantages over current traditional solutions. This Doctoral dissertation compiles the advances in the field of acoustic screening using this type of sonic crystals. However, there is still active research in this area which needs to be addressed and studied in order to apply this technology as noise reduction devices in transport infrastructures. Therefore, during the PhD student's training period, we have researched the acoustic phenomena produced by isolated scatterers in order to better understand the physical phenomena behind the lasts designs of this type of screen. One of these researches led to the discovery of interferences between the effects of resonance and multiple scattering of sonic crystals when occurring in nearby frequency ranges. Also we have designed a new noise reduction device based on sonic crystals, using multi-objective optimization tools, which would block and diffuse the noise. This new designing tool identified the need for a comparative study of the most commonly used simulation methods to estimate the performance of devices based on sonic crystals. Finally, we have carried out a psychoacoustic study that determined the perception of the annoyance reduction provided by acoustic screens based on sonic crystals and traditional barriers, determining whether the objective parameters that evaluate their performance match to the subjective response of the users.Agradezco al Ministerio de Ciencia e Innovación por la ayuda concedida dentro del programa Doctores Industriales. Asimismo, a mi tutor en empresa Dr. Juan José Martín Pino, por posibilitar la realización de esta investigación dentro de la empresa BECSA. Al Departamento de Física Aplicada de la Universitat Politècnica de València, a la Comisión Académica del Programa de Doctorado de Matemáticas y al Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica.Peiró Torres, MDP. (2021). Research of the acoustic phenomenon produced by isolated scatterers and its applicability as a noise reducing device in transport infrastructures. Search for an optimised and sustainable design [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/164903TESISCompendi

Interferences in Locally Resonant Sonic Metamaterials Formed from Helmholtz Resonators

[EN] The emergence of materials artificially designed to control the transmission of waves, generally called metamaterials, has been a hot topic in the field of acoustics for several years. The design of these metamaterials is usually carried out by overlapping different wave control mechanisms. An example of this trend is the so-called Locally Resonant Sonic Materials, being one of them the Phononic Crystals with a local resonant structure. These metamaterials are formed by sets of isolated resonators in such a way that the control of the waves is carried out by resonances and by the existence of Bragg bandgaps, which appear due to the ordered distribution of the resonators. Their use is based on the creation of resonance peaks to form additional nontransmission bands mainly in the low frequency regime, usually below the first Bragg frequency. The coupling of both gaps has been made in some cases, but it is not always so. In this work, using a periodic structure formed by Helmholtz resonators, we report the existence of interferences between the resonances and the Bragg bandgaps when they are working in nearby frequency ranges, so that they prevent the coupling of both gaps. We explain their physical principles and present possible solutions to mitigate them. To this end, we have developed numerical models based on the finite element method, and the results have been verified by means of accurate experimental results obtained under controlled conditions. Published under license by AIP Publishing.M.P.P.T. is grateful for the support of pre-doctoral Grant by the "Ministerio de Economia y Competitividad" of Spain through reference No. DI-15-08100.Peiró-Torres, MDP.; Castiñeira Ibáñez, S.; Redondo, J.; Sánchez Pérez, JV. (2019). Interferences in Locally Resonant Sonic Metamaterials Formed from Helmholtz Resonators. Applied Physics Letters. 114(17):1-4. https://doi.org/10.1063/1.5092375S1411417Fok, L., Ambati, M., & Zhang, X. (2008). Acoustic Metamaterials. MRS Bulletin, 33(10), 931-934. doi:10.1557/mrs2008.202Christensen, J., Romero-García, V., Picó, R., Cebrecos, A., de Abajo, F. J. G., Mortensen, N. A., … Sánchez-Morcillo, V. J. (2014). Extraordinary absorption of sound in porous lamella-crystals. Scientific Reports, 4(1). doi:10.1038/srep04674Liang, Z., Willatzen, M., Li, J., & Christensen, J. (2012). Tunable acoustic double negativity metamaterial. Scientific Reports, 2(1). doi:10.1038/srep00859Mei, J., Ma, G., Yang, M., Yang, Z., Wen, W., & Sheng, P. (2012). Dark acoustic metamaterials as super absorbers for low-frequency sound. Nature Communications, 3(1). doi:10.1038/ncomms1758Lee, S. H., Park, C. M., Seo, Y. M., Wang, Z. G., & Kim, C. K. (2010). Composite Acoustic Medium with Simultaneously Negative Density and Modulus. Physical Review Letters, 104(5). doi:10.1103/physrevlett.104.054301Fleury, R., Sounas, D. L., Sieck, C. F., Haberman, M. R., & Alù, A. (2014). Sound Isolation and Giant Linear Nonreciprocity in a Compact Acoustic Circulator. Science, 343(6170), 516-519. doi:10.1126/science.1246957Cheng, Y., Xu, J. Y., & Liu, X. J. (2008). One-dimensional structured ultrasonic metamaterials with simultaneously negative dynamic density and modulus. Physical Review B, 77(4). doi:10.1103/physrevb.77.045134Cheng, Y., Yang, F., Xu, J. Y., & Liu, X. J. (2008). A multilayer structured acoustic cloak with homogeneous isotropic materials. Applied Physics Letters, 92(15), 151913. doi:10.1063/1.2903500Sanchis, L., García-Chocano, V. M., Llopis-Pontiveros, R., Climente, A., Martínez-Pastor, J., Cervera, F., & Sánchez-Dehesa, J. (2013). Three-Dimensional Axisymmetric Cloak Based on the Cancellation of Acoustic Scattering from a Sphere. Physical Review Letters, 110(12). doi:10.1103/physrevlett.110.124301Farhat, M., Chen, P.-Y., Bağcı, H., Enoch, S., Guenneau, S., & Alù, A. (2014). Platonic Scattering Cancellation for Bending Waves in a Thin Plate. Scientific Reports, 4(1). doi:10.1038/srep04644Fang, N., Xi, D., Xu, J., Ambati, M., Srituravanich, W., Sun, C., & Zhang, X. (2006). Ultrasonic metamaterials with negative modulus. Nature Materials, 5(6), 452-456. doi:10.1038/nmat1644Shen, C., Xu, J., Fang, N. X., & Jing, Y. (2014). Anisotropic Complementary Acoustic Metamaterial for Canceling out Aberrating Layers. Physical Review X, 4(4). doi:10.1103/physrevx.4.041033Li, Y., Liang, B., Zou, X., & Cheng, J. (2013). Extraordinary acoustic transmission through ultrathin acoustic metamaterials by coiling up space. Applied Physics Letters, 103(6), 063509. doi:10.1063/1.4817925Tang, K., Qiu, C., Lu, J., Ke, M., & Liu, Z. (2015). Focusing and directional beaming effects of airborne sound through a planar lens with zigzag slits. Journal of Applied Physics, 117(2), 024503. doi:10.1063/1.4905910Cai, X., Guo, Q., Hu, G., & Yang, J. (2014). Ultrathin low-frequency sound absorbing panels based on coplanar spiral tubes or coplanar Helmholtz resonators. Applied Physics Letters, 105(12), 121901. doi:10.1063/1.4895617Leroy, V., Strybulevych, A., Lanoy, M., Lemoult, F., Tourin, A., & Page, J. H. (2015). Superabsorption of acoustic waves with bubble metascreens. Physical Review B, 91(2). doi:10.1103/physrevb.91.020301Hu, X., Chan, C. T., & Zi, J. (2005). Two-dimensional sonic crystals with Helmholtz resonators. Physical Review E, 71(5). doi:10.1103/physreve.71.055601Karimi, M., Croaker, P., & Kessissoglou, N. (2017). Acoustic scattering for 3D multi-directional periodic structures using the boundary element method. The Journal of the Acoustical Society of America, 141(1), 313-323. doi:10.1121/1.4973908Yang, X. W., Lee, J. S., & Kim, Y. Y. (2016). Effective mass density based topology optimization of locally resonant acoustic metamaterials for bandgap maximization. Journal of Sound and Vibration, 383, 89-107. doi:10.1016/j.jsv.2016.07.022Chen, Y., & Wang, L. (2014). Periodic co-continuous acoustic metamaterials with overlapping locally resonant and Bragg band gaps. Applied Physics Letters, 105(19), 191907. doi:10.1063/1.4902129Theocharis, G., Richoux, O., García, V. R., Merkel, A., & Tournat, V. (2014). Limits of slow sound propagation and transparency in lossy, locally resonant periodic structures. New Journal of Physics, 16(9), 093017. doi:10.1088/1367-2630/16/9/093017Lardeau, A., Groby, J.-P., & Romero-García, V. (2016). Broadband Transmission Loss Using the Overlap of Resonances in 3D Sonic Crystals. Crystals, 6(5), 51. doi:10.3390/cryst6050051Liu, Z., Zhang, X., Mao, Y., Zhu, Y. Y., Yang, Z., Chan, C. T., & Sheng, P. (2000). Locally Resonant Sonic Materials. Science, 289(5485), 1734-1736. doi:10.1126/science.289.5485.1734Park, C. M., & Lee, S. H. (2013). Propagation of acoustic waves in a metamaterial with a refractive index of near zero. Applied Physics Letters, 102(24), 241906. doi:10.1063/1.4811742Wang, T.-T., Wang, Y.-F., Wang, Y.-S., & Laude, V. (2018). Evanescent-wave tuning of a locally resonant sonic crystal. Applied Physics Letters, 113(23), 231901. doi:10.1063/1.5066058Yuan, B., Humphrey, V. F., Wen, J., & Wen, X. (2013). On the coupling of resonance and Bragg scattering effects in three-dimensional locally resonant sonic materials. Ultrasonics, 53(7), 1332-1343. doi:10.1016/j.ultras.2013.03.019Montiel, F., Chung, H., Karimi, M., & Kessissoglou, N. (2017). An analytical and numerical investigation of acoustic attenuation by a finite sonic crystal. Wave Motion, 70, 135-151. doi:10.1016/j.wavemoti.2016.12.002Sigalas, M. M., Economou, E. N., & Kafesaki, M. (1994). Spectral gaps for electromagnetic and scalar waves: Possible explanation for certain differences. Physical Review B, 50(5), 3393-3396. doi:10.1103/physrevb.50.3393Economou, E. N., & Sigalas, M. M. (1993). Classical wave propagation in periodic structures: Cermet versus network topology. Physical Review B, 48(18), 13434-13438. doi:10.1103/physrevb.48.13434Berenger, J.-P. (1994). A perfectly matched layer for the absorption of electromagnetic waves. Journal of Computational Physics, 114(2), 185-200. doi:10.1006/jcph.1994.115

Comparative study of simulation methods for the quantification of the acoustic insulation provided by periodic structures

[EN] Nowadays there are different available methods to perform simulations in acoustics. The suitability of them strongly depends on the system studied in each case. In the present work, a comparison between different methods (Multiple Scattering, Finite Elements Method and Finite Difference Time Domain) is carried out particularized to the quantification of the isolation provided by periodic structures (Sonic crystals). It has been considered a systematic study about computational time, precision and computational cost.[ES] Actualmente existen diferentes métodos para realizar simulaciones acústicas. La conveniencia de utilizar un método u otro depende del sistema que se estudia en cada caso. En este trabajo se realiza una comparativa entre diferentes métodos (Múltiple Scattering, Método de Elementos Finitos y Método de Diferencias Finitas en el Dominio del Tiempo) aplicados a la cuantificación del aislamiento proporcionado por estructuras periódicas (cristales de sonido). Se considera un estudio sistemático sobre tiempo computacional, la precisión y el coste computacional.This work was partially supported by the Spanish “MINISTERIO DE ECONOMIA, INDUSTRIA Y COMPETITIVIDAD” under the project TEC2015-68076-R.Parrilla-Navarro, MJ.; Redondo, J.; Sánchez Pérez, JV.; Peiró-Torres, MDP. (2018). Comparative study of simulation methods for the quantification of the acoustic insulation provided by periodic structures. Revista de Acústica. 49(1-2):3-10. http://hdl.handle.net/10251/112955S310491-

OPEN NOISE BARRIERS BASED ON SONIC CRYSTALS. ADVANCES IN NOISE CONTROL IN TRANSPORT INFRAESTRUCTURES

[EN] Noise control is an environmental problem of first magnitude nowadays. In this work, we present a new concept of acoustic screen designed to control the specific noise generated by transport infrastructures, based on new materials called sonic crystals. These materials are formed by arrangements of acoustic scatterers in air, and provide a new and different mechanism in the fight against noise from those of the classical screens. This mechanism is usually called multiple scattering and is due to their structuring in addition to their physical properties. Due to the separation between scatterers, these barriers are transparent to air and water allowing a reduction on their foundations. Tests carried out in a wind tunnel show a reduction of 42% in the overturning momentum compared to classical barriers. The acoustical performance of these barriers is shown in this work, explaining the new characteristics provided in the control of noise. Finally, an example of these barriers is presented and classified according to acoustic standardization tests. The acoustic barrier reported in this work provides a high technological solution in the field of noise control.Peiró Torres, MDP.; Redondo Pastor, FJ.; Bravo Plana-Sala, JM.; Sánchez Pérez, JV. (2016). OPEN NOISE BARRIERS BASED ON SONIC CRYSTALS. ADVANCES IN NOISE CONTROL IN TRANSPORT INFRAESTRUCTURES. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat Politècnica de València. 607-614. https://doi.org/10.4995/CIT2016.2016.4232OCS60761

Sonic Crystals Acoustic Screens and Diffusers

[EN] This article presents the use of advanced tools applied to the design of devices that can solve specific acoustic problems, improving the already existing devices based on classic technologies. Specifically, we have used two different configurations of a material called Sonic Crystals, which is formed by arrays of acoustic scatterers, to obtain acoustic screens with high diffusion properties by means of an optimization process. This design procedure has been carried out using a multiobjective evolutionary algorithm along to an acoustic simulation model developed with the numerical method called Finite Difference Time Domain. The results obtained are discussed in terms of both the acoustic performance and the robustness of the devices achieved.This work was partially supported by the Spanish "Ministerio de Economia y Competitividad" under the project TEC2015-68076-R.Peiró-Torres, MDP.; Parrilla-Navarro, MJ.; Ferri García, M.; Bravo, JM.; Sánchez Pérez, JV.; Redondo, J. (2019). Sonic Crystals Acoustic Screens and Diffusers. Applied Acoustics. 148:399-408. https://doi.org/10.1016/j.apacoust.2019.01.004S39940814

Técnicas y tecnologías en hidrología médica e hidroterapia

El objetivo del presente informe es difundir entre los profesionales médicos la información que contribuya a orientarles en la materia, conocer las aplicaciones terapéuticas o rehabilitadoras que pueden ofrecer los distintos centros termales y explorar su interacción con los tratamientos médicos habituales a los que suelen estar sometidos los usuarios de estos programas de termalismo

Clinical and genetic characteristics of late-onset Huntington's disease

Background: The frequency of late-onset Huntington's disease (>59 years) is assumed to be low and the clinical course milder. However, previous literature on late-onset disease is scarce and inconclusive. Objective: Our aim is to study clinical characteristics of late-onset compared to common-onset HD patients in a large cohort of HD patients from the Registry database. Methods: Participants with late- and common-onset (30–50 years)were compared for first clinical symptoms, disease progression, CAG repeat size and family history. Participants with a missing CAG repeat size, a repeat size of ≤35 or a UHDRS motor score of ≤5 were excluded. Results: Of 6007 eligible participants, 687 had late-onset (11.4%) and 3216 (53.5%) common-onset HD. Late-onset (n = 577) had significantly more gait and balance problems as first symptom compared to common-onset (n = 2408) (P <.001). Overall motor and cognitive performance (P <.001) were worse, however only disease motor progression was slower (coefficient, −0.58; SE 0.16; P <.001) compared to the common-onset group. Repeat size was significantly lower in the late-onset (n = 40.8; SD 1.6) compared to common-onset (n = 44.4; SD 2.8) (P <.001). Fewer late-onset patients (n = 451) had a positive family history compared to common-onset (n = 2940) (P <.001). Conclusions: Late-onset patients present more frequently with gait and balance problems as first symptom, and disease progression is not milder compared to common-onset HD patients apart from motor progression. The family history is likely to be negative, which might make diagnosing HD more difficult in this population. However, the balance and gait problems might be helpful in diagnosing HD in elderly patients

Clinical manifestations of intermediate allele carriers in Huntington disease

Objective: There is controversy about the clinical consequences of intermediate alleles (IAs) in Huntington disease (HD). The main objective of this study was to establish the clinical manifestations of IA carriers for a prospective, international, European HD registry. Methods: We assessed a cohort of participants at risk with <36 CAG repeats of the huntingtin (HTT) gene. Outcome measures were the Unified Huntington's Disease Rating Scale (UHDRS) motor, cognitive, and behavior domains, Total Functional Capacity (TFC), and quality of life (Short Form-36 [SF-36]). This cohort was subdivided into IA carriers (27-35 CAG) and controls (<27 CAG) and younger vs older participants. IA carriers and controls were compared for sociodemographic, environmental, and outcome measures. We used regression analysis to estimate the association of age and CAG repeats on the UHDRS scores. Results: Of 12,190 participants, 657 (5.38%) with <36 CAG repeats were identified: 76 IA carriers (11.56%) and 581 controls (88.44%). After correcting for multiple comparisons, at baseline, we found no significant differences between IA carriers and controls for total UHDRS motor, SF-36, behavioral, cognitive, or TFC scores. However, older participants with IAs had higher chorea scores compared to controls (p 0.001). Linear regression analysis showed that aging was the most contributing factor to increased UHDRS motor scores (p 0.002). On the other hand, 1-year follow-up data analysis showed IA carriers had greater cognitive decline compared to controls (p 0.002). Conclusions: Although aging worsened the UHDRS scores independently of the genetic status, IAs might confer a late-onset abnormal motor and cognitive phenotype. These results might have important implications for genetic counseling. ClinicalTrials.gov identifier: NCT01590589