Suchergebnisse

[ES] El proyecto europeo WOOL4BUILD se ubica dentro del programa de ECO-INNOVATION de EASME (Executive Agency for SMEs) de la European Commission. El objetivo de este proyecto es desarrollar un aislante térmico y acústico a partir de lana de oveja que pueda competir en cuanto a características técnicas y económicas con otros aislantes del mercado. En la Escuela Politécnica Superior de Gandía de la Universitat Politécnica de Valencia (EPSG-UPV) se han realizado diferentes ensayos acústicos de muestras elaboradas por otros socios del proyecto: ensayos de control en tubo de Kundt, de la resistividad al flujo del aire, en cámara reverberante, en cámaras a escala, etc. Estas muestras combinan diferentes densidades, espesores y porcentajes de calidad de lana de oveja. También desde la EPSG-UPV se ha confeccionado una herramienta informática, de libre acceso, que permite diseñar y justificar soluciones acústicas y térmicas basadas en estos nuevos materiales. ; [EN] The European WOOL4BUILD project is part of the European Commission's EASME (Executive Agency for SMEs) belonging to ECO-INNOVATION program. The objective of this project is to develop a thermal and acoustic insulation from sheep wool that can compete in terms of technical and economic characteristics with other insulation of this Market. Different acoustic tests have been carried out at the Polytechnic School of Gandía, of the Polytechnic University of Valencia (EPSG-UPV): control tests on Kundt tube, air flow resistivity, measurements in reverberant chamber of different samples made by other partners of the project, measurements in scale chambers, etc. The tested samples combine different densities, thicknesses and percentages of sheep wool quality. Adding to this, the EPSG-UPV has developed a free access computer tool, which allows making designs and also helps to justify acoustic and thermal solutions which are based on these new materials. ; This work was financially supported by Eco-innovation Initiative of the European Union. European Project ...

[EN] Fresnel Zone Plates are planar lenses that can be used to focus ultrasound beams. This kind of acoustic lenses can play a key role in the resolution of ultrasonic NDT systems. In this type of pulse-echo applications, the pulse duration is an important parameter that specifies the axial resolution, and thus, shorter ultrasound pulses provide higher resolutions. However, acoustic lenses exhibit a transient response that should be considered when setting the pulse duration, as pulses shorter than the transient state duration result in degradation in the response of acoustic lenses in terms of focal intensity, focal displacement, and lateral and axial resolutions. In this work, a thorough analysis of the transient response of Fresnel Zone Plates is discussed, demonstrating that the transient state should be considered in order to achieve optimal focusing performance. Theoretical and numerical results are presented, showing very good agreement. ; This work has been supported by Spanish MICINN RTI2018-100792-B-I00 project, Generalitat Valenciana AICO/2020/139 and the Russian Governmental program "Science" project FSWW-2020-0014. The research is carried out within the framework of Tomsk Polytechnic University Competitiveness Enhancement Program grant VIU-MNOL NK 187/2020. S.P.-L. acknowledges financial support from Universitat Politècnica de València grant program PAID-01-18. D.T.-S. acknowledges financial support from MICINN BES-2016-07713 project. ; Pérez-López, S.; Tarrazó-Serrano, D.; Dolmatov, DO.; Rubio Michavila, C.; Candelas Valiente, P. (2020). Transient Analysis of Fresnel Zone Plates for Ultrasound Focusing Applications. Sensors. 20(23):1-9. https://doi.org/10.3390/s20236824 ; S ; 1 ; 9 ; 20 ; 23 ; Albu, S., Joyce, E., Paniwnyk, L., Lorimer, J. P., & Mason, T. J. (2004). Potential for the use of ultrasound in the extraction of antioxidants from Rosmarinus officinalis for the food and pharmaceutical industry. Ultrasonics Sonochemistry, 11(3-4), 261-265. doi:10.1016/j.ultsonch.2004.01.015 ; Li, J.-T., ...

34002p1 34002p5 111 3 ; S ; The design and use of small apertures perforated in opaque plates to control the transmission of ultrasonic waves has been widely studied in recent years. The ultrasonic transmission response of brass plates perforated with Archimedean patterns of subwavelength hole arrays immersed in water is reported, both numerically and experimentally, in this work. It is shown that an increase in the geometrical isotropy of the elementary cells of the Archimedean patterns gives rise to a suppression of both minimum and maximum transmission corresponding to the destructive and constructive interferences, leading to uniformity within the angle-dependent transmitted sound power coefficient. The experimental results are in close agreement with the calculated ones. This property can be used to design ultrasonic devices such as filters and sensors. This work has been supported by the Spanish MICINN (MAT2010-16879) and Generalitat Valenciana (PROM-ETEOII/2014/026). Gómez Lozano, V.; Rubio Michavila, C.; Candelas Valiente, P.; Belmar Ibáñez, F.; Uris Martínez, A. (2015). Geometrical isotropy in perforated plates with subwavelength holes decorated with Archimedean patterns. EPL. 111(3):34002p1-34002p5. https://doi.org/10.1209/0295-5075/111/34002