Ultrasonic techniques have been used for many years for the inspection of rail. These measurements can detect the presence of a wide variety of defects but there are practical difficulties with the technology. While large transverse cracks of the type likely to cause catastrophic failure can be detected, the large, critical defects can be masked by large numbers of small, surface defects along ...

Piezoelectric wafer active sensors (PWAS) are inexpensive, non-intrusive, unobtrusive devices that can be surface-mounted on existing structures or inserted between the layers of new composite structures. The PWAS can be used in both active and passive modes. PWAS generate and detect Lamb waves and enable the development of embedded NDE concepts. This paper will present two embedded NDE concept...

It has been proved that ultrasonic energy can considerably increase the amount of oil recovery in an immiscible displacement process. Although many studies have been performed on investigating the roles of ultrasonic waves, based on the best of our knowledge, little attention has been paid to evaluate wave attenuation parameter, which is an important parameter in the determination of the energy...

Ultrasonic Guided Wave inspection of pipes has been extensively used in various industries such as oil, gas and petrochemical industries. The behavior of guided waves in straight pipes is well known but the presence of features like pipe bends, welds may distort the receiving signals. It is therefore a challenging task to study the behavior of guided waves through these features. However, the 3...

From an acoustical point of view, bone is a complex medium as it is heterogeneous, anisotropic and viscoelastic. This chapter reviews the basic notions of physical acoustics which are necessary to tackle the problem of the ultrasonic propagation in bone, in the perspective of the application of quantitative ultrasound (QUS) techniques to bone characterization. The first section introduces the b...

Most ultrasonic systems employing guided waves for flaw detection require information such as dispersion curves, transducer locations, and expected propagation loss. Degraded system performance may result if assumed parameter values do not accurately reflect the actual environment. By characterizing the propagating environment in situ at the time of test, potentially erroneous a priori estimate...

Ultrasonic guided waves have been used in testing of such an elongated object as pipe. Its sensitivity and distance resolution, however, have been limited by velocity dispersion and interference of numerous propagation modes of guided waves. Trapped energy mode of vibration of thickness shear waves in a quartz plate has been widely used in frequency control and selection due to its high Q and l...

it has been proved that ultrasonic energy can considerably increase the amount of oil recovery in animmiscible displacement process. although many studies have been performed on investigating theroles of ultrasonic waves, based on the best of our knowledge, little attention has been paid to evaluatewave attenuation parameter, which is an important parameter in the determination of the energydel...

Steel strands have been widely used in industrial fields as a reliable load-bearing component. Under the influence of environmental erosion and fatigue stress, different types damage, such corrosion fracture, will occur in-service steel strands, which cause unpredictable loss personnel property. Ultrasonic nondestructive testing technology has become an ideal method for long-distance metal stru...