Ultrasonic characterization of a fluid layer using a broadband transducer

Monitoring of an ascending air bubble in a viscous fluid/fiber matrix medium using a phased array transducer

“…Thus, signals resulting from round trips in the medium of interest ( Fig. 1(a)), can give the longitudinal and transverse wave velocity [11,12]. Especially ( Fig.…”

“…1(b)), the timeof-flight between two round trip signals s a (t) and s b (t) is involved in the phase of the transfer function T (f ) = S a (f )/S b (f ) between their respective spectra. Therefore, the transfer function T 2L (f ) results from the ratio between spectra of s 2L (t) and s 4L (t) denoted S 2L (f ) and S 4L (f ), respectively [11,12]. Similarly, the transfer function T LT (f ) results from the ratio between spectra of s 2L (t) and s LT (t) denoted S 2L (f ) and S LT (f ), respectively:…”

“…Particularly, for an echo with a Gaussian envelope, its normalized duration t n /T 0 for a given threshold at −n dB can be related directly to the transducer's relative bandwidth f 6 /f 0 [12]. This assumption of Gaussian envelope (Eq.…”

Effect of on-line ultrasonic treatment on the properties of carbon fiber reinforced plastic composites

“…Thus, ultrasonic treatment is widely used in chemical synthesis, depolymerization, extraction, food engineering, materials processing, etc. [20][21][22][23][24][25][26][27][28][29]. The cavitation and agitation action in the liquid induced by ultrasound improve the adsorption, diffusion, and wetting of resin on the surface of carbon fibers, enhance the mechanical properties, and finally use fully the outstanding property of CFRP composites [30][31][32][33][34].…”

Ultrasonic broadband characterization of a viscous liquid: Methods and perturbation factors

“…Their impact is studied in the context of an application on a production monitoring of composite plates by RTM. The dispersion in attenuation characteristic is modeled by power law [12][13][14]. The velocity dispersion is modeled by Szabo [15] and O'Donnell et al [16].…”