The scope of this study is to relate the acoustic activity of damage in composites to the failure mechanisms associated with these materials. Cross ply fiber reinforced composites were subjected to tensile loading with recording of their acoustic activity. Acoustic emission (AE) parameters were employed to monitor the transition of the damage mechanism from transverse cracking (mode I) to delam...

introduction: clostridium difficile is the etiologic agent of several infections such as pseudomembranous colitis in human. these diseases are frequently associated with antibiotic useage but many infections with this organisms are seen without antibiotic administration. in addition it is believed that clostridium difficile is one of the most important bacteria involved in acquired hospital inf...

In this paper, we continue to study the mechanisms of the receptivity of the supersonic boundary layer to free-stream disturbances by using both direct numerical simulation and linear stability theory. Specifically, the receptivity of a Mach 4.5 flow over a flat plate to free-stream fast acoustic waves is studied. The receptivity to free-stream slow acoustic waves, entropy waves and vorticity w...

In part 14 of the tutorial series "Acoustofluidics--exploiting ultrasonic standing wave forces and acoustic streaming in microfluidic systems for cell and particle manipulation", we provide a qualitative description of acoustic streaming and review its applications in lab-on-a-chip devices. The paper covers boundary layer driven streaming, including Schlichting and Rayleigh streaming, Eckart st...

A standing problem in the field of acoustic engineering is the automated design of buildings and structures for the purpose of obtaining desired acoustic properties, including noise metrics and metrics related to characteristics of the acoustic impulse response. These goals are related to the usefulness of the building or structure: a lecture hall should have clear and understandable sound from...

accurate permeability estimation has always been a concern in determining flow units, assigning appropriate capillary pressure andrelative permeability curves to reservoir rock types, geological modeling, and dynamic simulation.acoustic method can be used as analternative and effective tool for permeability determination. in this study, a four-step approach is proposed for permeability estimati...

We present a theoretical expression for the acoustic interaction force between small spherical particles suspended in an ideal fluid exposed to an external acoustic wave. The acoustic interaction force is the part of the acoustic radiation force on one given particle involving the scattered waves from the other particles. The particles, either compressible liquid droplets or elastic microsphere...