The matched spectrum and correlation characteristics are both important to realize the multichannel ultrasonic sensors working together. The spectrum matching can make full use of the bandwidth of the ultrasonic ranging system, and the good correlation characteristic can eliminate crosstalk among multichannel ultrasonic sensors triggering simultaneously. Linear frequency modulation (LFM) excita...

The aim of this study was to evaluate ultrasonic P-wave velocity as a feature for predicting some physical and mechanical properties that describe the behavior of local building limestone. To this end, both ultrasonic testing and compressive tests were carried out on several limestone specimens and statistical correlation between ultrasonic velocity and density, compressive strength, and modulu...

Modulus of elasticity is one of the important parameters of construction materials, which considerably influence their deformation properties and which can also be determined by means of non-destructive test methods like ultrasonic pulse method. However, measurement results of ultrasonic pulse methods are influenced by various factors, one of which is the natural frequency of the transducers. T...

A series of materials used for oil absorption based on cellulose fiber grafted with butyl acrylate (BuAc) have been prepared by radical polymerization under ultrasonic waves processing. Effects of ultrasonic dose for the maximum graft yield were considered. The dependency of optimum conditions for oil absorption rate on parameters such as ultrasonic processing time and ultrasonic power were als...

The crosstalk in multichannel simultaneously triggered ultrasonic sensors of ultrasonic ranging system may cause false measurement. This paper presents pseudorandom digital modulation excitation sequences for multichannel ultrasonic sensors to avoid crosstalk. To make full use of bandwidth of the ultrasonic sensors, the parameters of the pseudorandom digital modulation methods are configured. A...

Scattering of ultrasonic waves in polycrystals with texture is studied in this article. The attenuations of the three wave modes are determined as a function of dimensionless frequency and propagation direction, respectively, for given orientation distribution coefficients (ODCs). The calculation is done in the case of a statistically orthorhombic sample made up of cubic crystallites. The wave ...

background: bisphenol-a is categorized as a toxic and refractory organic matter. ultrasonic process considered as an effective method for degradation of refractory organic matters in the environment which is achieved by the production of fine bubbles through cavitation process. this study is conducted for assessment of the toxicity of effluents containing bisphenol-a which was treated by ultras...