Title of Dissertation: SMART FOAM FOR ACTIVE VIBRATION AND NOISE CONTROL Wael Nabil Akl, Doctor of Philosophy, 2004 Dissertation Directed By: Professor Amr M. Baz Department Mechanical Engineering A new class of smart foams is introduced to simultaneously control the vibration and noise radiation from flexible plates coupled with acoustic cavities. The proposed smart foam consists of a passive ...

In this study, free vibration of a foam-core orthotropic smart composite cylindrical shell (SCCS) filled with a non-viscous compressible fluid, subjected to combined electro-thermo-mechanical loads is investigated.  Piezoelectric polymeric cylindrical shell, is made from polyvinylidene fluoride (PVDF) and reinforced by armchair double walled boron nitride nanotubes (DWBNNTs). Characteristics of...

This work investigates and compares the potential of adaptive feedforward and feedback methods for a hybrid active/passive radiation control using smart foam. The radiating structure is a vibrating plate mounted in a rigid baffle in an anechoic chamber. The smart foam, designed to reduce sound by the action of the passive absorption of the foam ~which is effective at higher frequencies! and the...

In recent years, textile based wound dressing products have grown from simple gauze to smart dressings with considerable technical and commercial impact. Today, wound dressings are manufactured from a large variety of different materials and applied in all phases of wound healing. In this study, commercially available wound dressing products were investigated and compared in vitro. The dressing...

this investigation presents the effect of various parameters on foam stability and its rheological properties. the underlying idea of this experiment is generating of drilling foam with uniform bubbles. the main problem of foam using is controlling its stability during field application. the most important parameters which cause instability in foam are gravity drainage, gas diffusion and bubble...

The annular foam breaker is one which uses the vacuum and shear force generated by the Coanda effect to break foam. Its effectiveness in destroying drilling foam has been test in wellbore flow simulation loop experimental stand. Experimental results showed that the operating pressure of the annular foam breaker should be larger than 0.6MPa and the stabilizers concentration of the foam drilling ...