Sound synthesis methods aim at the auralization of the sound produced by a physical sound source as it is heard by a listener at an arbitrary location. In order to suit the synthesis approach, the physical source is represented by an acoustic equivalent source model which behaves similar in the far field. However, it is not straightforward to determine the number, the position, the type, . . . ...

This work investigates the acoustical properties of a multilayer porous material in which periodic inclusions are embedded. The material is assumed to be backed by a rigid wall. Most of the studies performed in this field used the multipole method and are limited to circular shape inclusions. Here, a mode matching approach, more convenient for a layered system, is adopted. The inclusions can be...

Polyethylene wear increasingly has been blamed for osteolysis and granuloma formation after total joint arthroplasty. The authors evaluated the wear difference between bearing surfaces of stainless steel, cobalt chrome, and titanium alloy. They also compared cemented all-polyethylene molded cups with cemented metal-backed molded acetabular cups. These were compared with molded and machined poly...

We examined radiographic polyethylene wear in 233 cemented total hip arthroplasties (201 patients) with either a metal-backed or a non-metal-backed acetabular cup. All patients had identical cemented one-piece titanium femoral stems with a femoral head diameter of 28 mm. The mean linear wear rate was 0.11 mm/yr in metal-backed sockets and 0.08 mm/yr in non-metal-backed sockets (p = 0.0002). The...

An optimized unit cell design of a micro-slit resonant metamaterial is proposed to increase the size frequency stop-bands and enhance sound absorption at normal incidence. Micro-slit metamaterials offer compact lightweight solution for low-frequency noise reduction, in contrast traditional methods such as absorptive foams. A combination numerical semi-analytical solutions based on dispersion cu...

Design and experimental verification of an ultrawideband planar circularly polarized ultrahigh frequency (UHF) sensor is presented for detection partial discharge (PD) activities in high voltage (HV) equipment. The proposed cavity-backed cosine slot Archimedean spiral (CSAS) antenna with electromagnetic (EM) transparent radome. dual-arm was meandered as wave size reduction optimized broadband o...

The new study has been prompted by indications from researchers at Australia's Casey Station which suggest the subglacial basins could make the East Antarctic ice sheet more vulnerable in a warming world. Satellite data suggest that the Totten Glacier, which dominates the ice of the Aurora subglacial basin, appears to be losing ice at its downstream edge. " We are getting more science done with...