This work examines the impact of local losses produced by a resistive wiremesh on the modes of an acoustic cavity. In the one-dimensional case, we demonstrate the ability to selectively affect the modes, ranging from being completely unaffected by the wiremesh to being fully absorbed by it. This effect can be used to filter the cavity modes. In the two-dimensional case, higher order modes are considered and we discuss the effect of wiremesh tilt on the cavity modes. A new type of mode that is localized on the wiremesh with a purely imaginary eigenfrequency has been identified. These findings show that wiremeshes are ultrabroadband lossy metasurfaces offering a straightforward way to explore passive non-Hermitian systems.
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http://dx.doi.org/10.1121/10.0026541 | DOI Listing |
J Acoust Soc Am
July 2024
Laboratoire d'Acoustique de l'Université du Mans (LAUM), UMR 6613, Institut d'Acoustique - Graduate School (IA-GS), CNRS, Le Mans Université, Avenue O. Messiaen, 72085 Le Mans Cedex 9, France.
This work examines the impact of local losses produced by a resistive wiremesh on the modes of an acoustic cavity. In the one-dimensional case, we demonstrate the ability to selectively affect the modes, ranging from being completely unaffected by the wiremesh to being fully absorbed by it. This effect can be used to filter the cavity modes.
View Article and Find Full Text PDFSensors (Basel)
June 2022
Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands.
The performance of multiphase flow processes is often determined by the distribution of phases inside the equipment. However, controllers in the field are typically implemented based on flow variables, which are simpler to measure, but indirectly connected to performance (e.g.
View Article and Find Full Text PDFSci Rep
July 2019
Laboratoire d'Acoustique de l'Université du Mans, Centre National de la Recherche Scientifique (CNRS), Le Mans Université, Avenue Olivier Messiaen, 72085, Le Mans, Cedex 9, France.
The acoustic effects of in-parallel resonators is compared to the behavior of a classical single degree of freedom resonator for which the resistance and the mass are in series. In-parallel resonators serve to enhance the acoustic absorption for mid-frequencies thereby extending the active frequency range of perfect acoustic absorbers. Two implementations of these in-parallel absorbers are presented and investigated experimentally as well as numerically.
View Article and Find Full Text PDFActa Trop
May 2018
Centre for International Health, University of Bergen, Bergen, Norway. Electronic address:
House is the major site for malaria infection where most human-vector contact takes place. Hence, improving housing might reduce the risk of malaria infection by limiting house entry of vectors. This study aimed to explore the impact of screening doors and windows with wire meshes on density and entomological inoculation rate (EIR) of malaria vector, and malaria incidence, and assess the acceptability, durability, and cost of the intervention.
View Article and Find Full Text PDFInfect Dis Poverty
November 2017
Unité d'Entomologie Médicale, Institut Pasteur de Madagascar, Ambatofotsikely, 101, Antananarivo, PO box 1274, Madagascar.
Background: Prisons in Madagascar are at high risk of plague outbreak. Occurrence of plague epidemic in prisons can cause significant episode of urban plague through the movement of potentially infected humans, rodents and fleas. Rodent and flea controls are essential in plague prevention, by reducing human contact with plague reservoirs and vectors.
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