The structure, adsorption behavior and applications of eggshell waste materials have been
reviewed. The ultrastructure of eggshell particles has been discussed to understand the …

Roughness www. SandV. com MATERIALS REFERENCE ISSUE 13 sound waves to enter
the materials through a multitude of small holes or openings. Materials made from open …

According to the World Health Organization, noise pollution is second only to air pollution in
its impact on health and the environment. Fiber-based sound-absorbing structures have …

This paper presents the development of an acoustic energy harvester using an
electromechanical Helmholtz resonator (EMHR). The EMHR consists of an orifice, cavity …

This work investigates a porous composite with modifiable micro-geometry so that its ability
to absorb noise can be accommodated to different frequency ranges. The polymeric …

The pressure-based, current-driven impedance control technique known as “Electroacoustic
Absorption” has offered new horizons for room modal equalization at low frequencies …

The development of a tunable, multiple degree of freedom (MDOF) electromechanical
Helmholtz resonator (EMHR) is presented. An EMHR consists of an orifice, backing cavity …

This paper deals with active sound attenuation in lined ducts with flow and its application to
duct modes damping in aircraft engine nacelles. It presents an active lining concept based …

We propose and design a new adaptive sound absorption metamaterial targeting
broadband airborne noise at extremely low frequencies. The metamaterial consists of two …

Sound waves are reflected and absorbed by a passive side-branch device in a duct. The
performance is limited at low frequencies if the cavity is compact. In this study, an electro …