background: organophosphorus pesticides are one of the most prevalent usages for pest control in the country. such pesti­cides enter into water sources by different routes. since drinking of contaminated water at the higher doses than the standard level, may causes undesirable effects to human health and ecosystem. the object of this research was to investigate the ef­fect of various parameters...

A noise abatement method using an eigen function in conjunction with optimizer (Genetic Algorithm) under a space-constrain situation is proposed this study concerning high order wave propagation effect. An used to describe acoustical field and shorten the model four-pole transfer matrix form. The system’s estimates Transmission Loss (TL) for silencers by multiplying individual matrices.

We report a newly discovered anomalous incident-angle of an elastically refracted P-wave, arising from a P-wave impinging on an interface between two VTI media with strong anisotropy. This anomalous incident-angle is found to be located in the post-critical incident-angle region corresponding to a refracted P-wave. Invoking Snell's law for a refracted P-wave provides two distinctive solutions b...

We formulate a model for acoustic excitations in a magnetorheological fluid. Constitutive equations are derived for Navier-Stokes flow coupled with Maxwell’s Equations. The viscosity of the fluid is modified to reflect the dependence of waves propagating within the fluid itself and in the case where they propagate along the network of particles.

al’s properties and acoustical characteristics have been studied for a long time and ultrasonic techniques have been used in non-destructive testing and imaging for decades. Ultrasound as an analytical tool has revolutionised diagnostics in medicine, but the application of ultrasound to material’s analyses has been held back by problems with ultrasonic design, electronics, sample handling, comp...

This article is concerned with a version of photoacoustic computed tomography, that uses line detectors (instead of point-like ones) for the recording of induced acoustical data. The three dimensional imaging problem, consisting in reconstructing the unknown density function from recorded data, is reduced to a series of two dimensional problems: First, the initial data of the two dimensional wa...

One of the challenges Internet Underwater Things (IoUT) is design nodes for collecting information from underwater, with features low cost, long term, range, voyage routing, and real-time communications. Wave glider, has shown great potential acting as IoUT through its persistent, long-range traveling, flexibility underwater. In this article, we propose an architecture IoUT, involving multiple ...

The acoustic wave attenuation is described by an experimentally established frequency power law in a variety of complex media, e.g., biological tissue, polymers, rocks, and rubber. Recent papers present a variety of acoustical fractional derivative wave equations that have the ability to model power-law attenuation. On the other hand, a multiple relaxation model is widely recognized as a physic...

We compare two approaches for deriving the fact that the Green’s function in an arbitrary inhomogeneous open system can be obtained by cross correlating recordings of the wave field at two positions. One approach is based on physical arguments, exploiting the principle of time-reversal invariance of the acoustic wave equation. The other approach is based on Rayleigh’s reciprocity theorem. Using...

The advent of transformation optics and metamaterials has made possible devices producing extreme effects on wave propagation. Here we describe a class of invisible reservoirs and amplifiers for waves, which we refer to as Schrödinger hats. The unifying mathematical principle on which these are based admits such devices for any time harmonic waves modeled by either the Helmholtz or Schrödinger ...