This paper explains non-linear non-destructive evaluation of concrete aimed at examining the occurrence of non-linearity under non-linear wave propagation through the concrete. Standard cubic concrete sections in damaged and undamaged conditions were investigated. The specimen was first damaged under compression testing and then subjected to non-linear ultrasonic evaluation in two directions i....

Using the technique of terahertz photomixing, a continuous-wave terahertz source is used to characterise various semiconductors in the frequency range from 0.06 to 1.0 THz. By directly analysing the interference pattern of the transmission through semiconductor wafers using Fabry-Pérot theory, information regarding the carrier concentration, sample thickness and refractive index is obtained wit...

6 Common techniques to monitor the quality of fruit at the time of harvest and in storage typically rely on destructive methods to measure physical properties such as firmness and hydration. The complex, inhomogeneous composition of most fruit mean that non-destructive ultrasonic methods for quality evaluation of fruit has typically been unsuccessful. A novel ultrasound method was developed whi...