Abstract A relatively new concept of sound absorption herein denominated as Metaporous concrete is presented, consisting a porous concrete-based absorber in which different acoustic resonators are embedded. Two finite element models were implemented, using the fluid-equivalent theory to describe solutions. Helmholtz resonator, samples, and prototype built tested through experimental techniques ...

Modal active control enables modifications of the damping and the frequencies of the different resonances of a system. A self-sustained oscillating wind instrument is modelled as a disturbance coupled to a resonator through a non-linear coupling. The aim of this study is to present simulations of modal active control applied to a modeled simplified self-sustained oscillating wind instrument (e....

Thermoacoustics describes energy conversion processes, activated by interaction temperature oscillation, accompanying the pressure oscillation in a sound wave, with solid boundaries. In ordinary experience this interaction of sound and heat cannot be observed, because of the very low temperature differences, but under suitable conditions, it can be emphasized and amplified to create remarkable ...

We present a numerical investigation of an acoustic sensor based on cylindrical resonator to monitor the properties liquids flowing in tube. The design consists hollow washer surrounding tube, which carries liquid, and can be filled during sensing process. Due impedance mismatch between liquid solid washer, we demonstrate presence high-quality factor resonances associated with (such as velocity...

In this paper, for the first time to our knowledge, we investigate the optical bi-stability in a compact parallel array of micro- ring resonators with 5μm radius, induced by optical nonlinearity. Due to the nature of perfect light confinement, resonance and accumulation process in a ring resonator, optical nonlinear effects, even at small optical power of a few milliwatts in this structure are ...

Acoustic materials such as plastic carpet, gypsum board, styrofoam and plywood can be used to reduce sound intensity. Nevertheless, the existing research has generally focused on single-ingredient studies. In this research, optimum thickness of each material will sought based its efficiency in reducing intensity level. Besides that, various types also tested for level study, a resonator tube wa...

The development of numerical techniques now permits us to analyze complex structures such as dielectric resonator filters and planar passive elements for coplanar monolithic microwave integrated circuits. In this paper, we describe a novel method for designing dielectric resonator filters. Then a Chebychev band pass filter is designed by coaxially placing high-Q TM01Q dielectric resonators ...