The study of surface phonon dispersion curves is motivated by the quest for a detailed understanding of the forces between the atoms at the surface and in the bulk. In the case of graphene, additional motivation comes from the fact that thermal conductivity is dominated by contributions from acoustic phonons, while optical phonon properties are essential to understand Raman spectra. In this art...

In this paper we present a novel broadband approach for the extraction of dispersion curves of multiple time frequency overlapped dispersive modes such as in borehole acoustic data. The new approach works jointly in the Fourier and space time domains and, in contrast to existing space time approaches that mainly work for time frequency separated signals, efficiently handles multiple signals wit...

Articles you may be interested in Dispersion engineering of high-Q silicon microresonators via thermal oxidation Appl. Investigation on the optimized design of alternate-hole-defect for 2D phononic crystal based silicon microresonators J. External acoustic load on the performance of a travelling-wave thermoacoustic engine AIP Conf.

In the forward problem of acoustic tomography, one needs to be able to implement the wave equation numerically and find the values at each receiver point. In this research the possible solutions are studied and their properties are discussed and one proposed algorithm is selected as the satisfactory result in the sense of less numerical dispersion. Stability conditions for these algorithms are ...

We present the results of kinetic numerical simulations that demonstrate the existence of a novel branch of electrostatic nonlinear waves driven by particle trapping processes. These waves have an acoustic-type dispersion with phase speed comparable to the ion thermal speed and would thus be heavily Landau damped in the linear regime. At variance with the ion-acoustic waves, this novel electros...

by Wenlong Zhang This dissertation studied the interaction of nonuniform flows with propeller blades in a submerged elastic duct. The acoustic radiation from the duct is calculated and correlated to the flow nonuniformities and the propeller and duct characteristics. First, a benchmark problem is studied wherein the sound radiation from an infinite plate with or without ribs is examined for dif...

We investigated theoretically the specific heat of graphene, bilayer graphene and twisted bilayer graphene taking into account the exact phonon dispersion and density of states for each polarization branch. It is shown that contrary to a conventional belief the dispersion of the out-of-plane acoustic phonons - referred to as ZA phonons - deviates strongly from a parabolic law starting from the ...

Dissolved Air Flotation (DAF) is a method for separating suspended, microscopic particles in water and wastewater treatment. The basic idea is to generate huge amounts of microscopic bubbles, which should attach to the particles whereby less dense aggregates are obtained, rising to the water surface. The flow structure in a flotation tank is important for the separation efficiency. ADV measurem...

We simulate the natural frequencies and the acoustic wave propagation characteristics of graphene nanoribbons (GNRs) of the type (8,0) and (0,8) using an equivalent atomistic-continuum FE model previously developed by some of the authors, where the C-C bonds thickness and average equilibrium lengths during the dynamic loading are identified through the minimisation of the system Hamiltonian. A ...

A one-dimensional acoustic negative refractive index metamaterial based on the transmission line approach is presented. This structure implements the dual transmission line concept extensively investigated in microwave engineering. It consists of an acoustic waveguide periodically loaded with membranes realizing the function of series “capacitances” and transversally connected open channels rea...