Low frequency sound propagation in activated carbon

Low frequency sound propagation in activated carbon.

Activated carbon can adsorb and desorb gas molecules onto and off its surface. Research has examined whether this sorption affects low frequency sound waves, with pressures typical of audible sound, interacting with granular activated carbon. Impedance tube measurements were undertaken examining the resonant frequencies of Helmholtz resonators with different backing materials. It was found that...

Low-Frequency Sound Propagation in Lipid Membranes

In the recent years, we have shown that cylindrical biological membranes such as nerve axons under physiological conditions are able to support stable electromechanical pulses called solitons. These pulses sharemany similarities with the nervous impulse, for example, thepropagationvelocityaswell as themeasured reversibleheatproductionandchanges in thickness and length that cannot be explained w...

Sound Wave Propagation in Viscous Liquid-Filled Non-Rigid Carbon Nanotube with Finite Length

   In this paper, numerical results obtained and explained from an exact formula in relation to sound pressure load due to the presence of liquid inside the finite-length non-rigid carbon nanotubes (CNTs), which is coupled with the dynamic equations of motion for the CNT. To demonstrate the accuracy of this work, the obtained formula has been compared to what has been used by other research...

Sound propagation in and low frequency noise absorption by helium-filled porous material.

Low-frequency noise is difficult to deal with by traditional porous material due to its inherent high acoustic impedance. This study seeks to extend the effective range of sound absorption to lower frequencies by filling a low density gas, such as helium, in the porous material. Compared with conventional air-filled absorption material, the helium-filled porous material has a much reduced chara...

Title Sound propagation in and low frequency noise absorption byhelium - filled porous material