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...

This paper develops a three-dimensional analytical model of a fluid-loaded acoustic coating affixed to a rib-stiffened plate. The system is loaded by a plane wave that is harmonic both spatially and temporally. The model begins with Navier–Cauchy equations of motion for an elastic solid, which produces displacement fields that have unknown wave propagation coefficients. These are inserted into ...

A big challenge in studying organic rich shale is to predict its kerogen content and maturity from indirect observations. Kerogen maturation changes shale texture; for example, it generates microcracks and fractures in the matrix. Assessment of maturity from indirect measurements can be greatly enhanced by exploiting any existing correlations between physical properties, microstructure, and ker...

The initial objective was to implement a 3D Gaussian beam model on multi-core, high-performance computing hardware in order to support mid and high frequency applications like reverberation modeling and acoustic channel simulation. As graphic processing unit or GPU hardware rapidly emerged as a compelling platform for such work, my objective became to adapt selected acoustic wave propagation mo...

With the rapid growth of indoor wireless communication systems, the need to accurately model radio wave propagation inside the building environments has increased. Many site-specific methods have been proposed for modeling indoor radio channels. Among these methods, the ray tracing algorithm and the finite-difference time domain (FDTD) method are the most popular ones. The ray tracing approach ...

The initial objective was to implement a 3D Gaussian beam model on multi-core, high-performance computing hardware in order to support mid and high frequency applications like reverberation modeling and acoustic channel simulation. As graphic processing unit or GPU hardware rapidly emerged as a compelling platform for such work, my objective became to adapt selected acoustic wave propagation mo...

IMPLEMENTATION AND EVALUATION OF DISPERSION-INVARIANT FEATURES FOR SIGNAL CLASSIFICATION Greg Okopal, M.S. University of Pittsburgh, 2007 When a sound wave interacts with an object, the acoustic energy may excite resonances in the object corresponding to its natural modes of vibration. The backscattered wave will then contain information which can be used to distinguish among different objects....

The multi-chamber reactive silencers are widely used to reduce engine exhaust noise as well as blower intake and discharge noise. Davis et al. [1] developed a one-dimensional analytical approach, which assumes plane wave propagation in the axial direction in silencers, to predict the acoustic attenuation performance of double expansion chamber reactive silencers, and compared the predictions wi...