In this paper, we propose a novel wavelet coefficient threshold (WCT) depended on both time and frequency information for providing robustness to non-stationary and correlated noisy environments. A perceptual wavelet filter-bank (PWFB) is firstly used to decompose the noisy speech signal into critical bands according to critical bands of psycho-acoustic model of human auditory system. The estim...

A simple correlated channel model for ultrawideband (UWB) multiple-antenna systems is proposed. The authors show that a single numerical value of the spatial correlation coefficient is sufficient to accurately model the performance of UWB spatial multiplexing systems in an indoor environment. The appropriate value of the correlation coefficient is selected by ensuring a close match between the ...

In this work, a liquid chromatography stability-indicating method was developed and applied to study the hydrolytic behavior of simvastatin in different pH values and temperatures. The selected chromatographic conditions were a C18 column; acetonitrile-28 mM phosphate buffer solution, pH 4 (65 + 35) as the mobile phase; 251 degrees C column temperature; and flow rate 1 mL/min. The developed met...

Elucidation and quantitative determination of some of commonly used penicillins (ampicillin, penicillin G and carbenicillin) in the presence of their main degradation product (penicilloic acid) were developed. Forced acidic and basic degradation processes were applied at different time intervals. The formed degradation products were elucidated and quantified using surface enhanced Raman spectro...

The degradation efficiency of organic contaminants and their associated metabolites by co-culture of microbes is mainly limited by toxic intermediates from co-metabolic degradation. In this study, we investigated the degradation of β-cypermethrin (β-CY) and 3-phenoxybenzoic acid (3-PBA) by co-culture of Bacillus licheniformis B-1 and Aspergillus oryzae M-4, as well as the influences of β-CY and...

The expansion of a microbial bank for the degradation of polycyclic aromatic hydrocarbons (PAHs) is crucial for removal of these persistent pollutants. In this study, five gram-negative, aerobic, non-fermentative bacterial strains (III-R3, IV-P11, IV-P13, IV-R13, and V-P18) were isolated from the activated sludge of a petrochemical wastewater treatment plant using enrichment pro­ tocol based on...

A sensitive, selective and stability indicating reverse phase method has been developed for the quantitative determination of potential impurities of Desvenlafaxine succinate monohydrate active pharmaceutical ingredient. Efficient chromatographic separation was achived on C8 stationary phase. Forced degradation study confirmed that the newly developed method was specific and selective to the de...

For laser assisted Shape Deposition Manufacturing (SDM), residual stresses caused by the temperature gradient and material property mismatches result in part inaccuracy, warpage, or even delamination. The use of low coefficient of thermal expansion (CTE) materials such as Invar promises to reduce deformations caused by internal stresses [2]. Thus, to obtain high quality of prototypes for moldin...

The hangers of a suspension bridge is one of the most important stressed members, the thorough research of the deterioration during operation period and the security analysis after the degeneration of hangers is essential. This is the basis of the strategy of preventive maintenance of suspension bridges. Firstly, the paper studies the four stages of degradation mechanisms of sling and calculati...