Ultrasonic tomographic imaging of solid objects in air using an array of fan-shaped-beam electrostatic transducers

Ultrasound tomography

“…Chen and Sanderson (1996) used a reflection system and imaged air bubbles in water using a fixed transmitter and a positionable receiver. Brown and Reilly (1996) also used repositionable transducers, but in a transmission system, and they were capable of imaging solid objects in air. Xu and co-workers (Xu, Han, Xu, & Yang, 1997) used a transmission system to detect bubbles in a liquid flow and were able to use their ultrasound tomography system to classify different types of two-phase flows such as bubble, slug, annular and stratified flow.…”

“…Brown, Reilly, and Mills (1996) used a transmission system with 18 transducers to detect solid objects in a gas system. Chen and Sanderson (1996) used a reflection system and imaged air bubbles in water using a fixed transmitter and a positionable receiver.…”

Fabrication of Ambipolar Organic Heterojunction Transistors with Various Sexithiophene Alkyl-Substituted Derivatives

“…The simplest implementation of the transformation described above is linear back projection (LBP), which was originally developed for hard-field techniques. Variants of LBP have now also been employed in a number of softfield applications [18][19][20]. For example, in ECT,Q is generated by calculating the perturbation to the background capacitance measurements resulting from each pixel in turn being occupied by the target material (such as oil or water) [21].…”

Development of an ultrasonic tomography system for application in pneumatic conveying

“…Use of a convex radiating element is considered the most practical method of producing the required directivity [33]. Angular directivity plots obtained from an aircoupled transducer employing a semi-cylindrical radiating element are presented in figures 7(a) and (b).…”