The acoustic power of an oscillating flame is measured. A turbulent premixed propane/air flame is situated near a pressure antinode of a standing wave in a laboratory combustion chamber. This standing wave is generated by a piston. The fluctuating heat release of the flame will supply acoustic power to the standing wave as postulated by Rayleigh. This flame acoustic power is obtained by setting...

Acoustic wave devices coated with a biolayer represent one biosensor approach for the detection of medically relevant biomolecules. In a typical application, the acoustic wave device is connected in an oscillator circuit, and the frequency shift f resulting from a biomolecular event is recorded. In this paper, we discuss our recent work in this field, which has included the use of Rayleigh wave...

Optical parametric chirped pulse amplification (OPCPA) is one of the most powerful techniques for generating high-energy femtosecond laser pulses. Many efforts were devoted to get spectral-band amplification able to support sub-10-fs pulses. In the optical parametric amplification (OPA), broad gain bandwidths can be obtained if the wave-vectors mismatch, ∆k, slowly increases when the signal fre...

OBJECTIVE The aims of this study were to (1) detect the presence and edge frequency (fe) of a cochlear dead region in the ear with residual acoustic hearing for bimodal cochlear implant users, and (2) determine whether amplification based on the presence or absence of a dead region would improve speech understanding and sound quality. DESIGN Twenty-two listeners with a cochlear implant in one...

Insects have evolved diverse and delicate morphological structures in order to capture the inherently low energy of a propagating sound wave. In mosquitoes, the capture of acoustic energy and its transduction into neuronal signals are assisted by the active mechanical participation of the scolopidia. We propose a simple microscopic mechanistic model of the active amplification in the mosquito s...

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...

We study the effect of corotation resonance on the inertial-acoustic oscillations (pmodes) of black-hole accretion discs. Previous works have shown that for barotropic flows (where the pressure depends only on the density), wave absorption at the corotation resonance can lead to mode growth when the disc vortensity, ζ = κ/(2ΩΣ) (where Ω, κ, Σ are the rotation rate, radial epicyclic frequency an...