This paper presents an analytical approach of the propagation of an acoustic wave through a normally distributed disordered lattice made up of Helmholtz resonators connected to a cylindrical duct. This approach allows to determine analytically the exact transmission coefficient of a weakly disordered lattice. Analytical results are compared to a well-known numerical method based on a matrix pro...

refractor ambiguities are big problem in seismic refraction method especially in seismic engineering. there can be hidden subsurface geological phenomena such as hidden faults and shear zones which are not simply predicted by the travel-time graph or some geophysical methods. head wave amplitudes are used to show the resolution of refractor ambiguities and the existence of anisotropy in complex...

Fault zone structures at many scales largely dictate earthquake ruptures and are controlled by the geologic setting slip history. Characterizations of these diverse inform better understandings hazards phenomenology. However, characterizing fault zones sub-kilometer has historically been challenging, challenges exacerbated in urban areas, where locating faults is critical for hazard assessment....

A new technique is described for imaging obstacles using the acoustic far "eld response for plane wave incidence. The method requires no a priori information about the surface, nor does it depend upon prior knowledge of the surface boundary conditions. The algorithm is straightforward to implement and is illustrated by imaging multiple targets simultaneously for various surface boundary conditi...

Time-reversal invariant topological insulator is widely recognized as one of the fundamental discoveries in condensed matter physics, for which the most fascinating hallmark is perhaps a spin-based topological protection, the absence of scattering of conduction electrons with certain spins on matter surface. Recently, it has created a paradigm shift for topological insulators, from electronics ...

In thermoacoustic scattering the scattered field consists of a propagating acoustic wave together with a non-progagational “thermal” wave of much shorter wavelength. Although the scattered field may be obtained from a Rayleigh expansion, in cases where the particle radius is small compared with the acoustic wave length, these solutions are ill-conditioned. For this reason asymptotic or perturba...

In Space, minor forces exerted over long periods can produce major results. Force fields of various kinds can be used to build large structures, superseding the human-intensive construction techniques of today. In this paper we consider how several techniques now used in other fields can be generalized and applied to Space-based construction. Radiation pressure exerted by coherent beams on scat...