Acoustic emission (AE) testing was deployed on details of two large steel Interstate Highway bridges: one cantilever through-truss and one trapezoidal box girder bridge. Quantitative measurements of activity levels at known and suspected crack locations were made by monitoring AE under normal service loads (e.g., live traffic and wind). AE indications were used to direct application of radiogra...

Behavioral audiometry may be of limited value for those patients who have incurred significant brain injury and remain unresponsive to auditory stimuli. Even the more "objective" tests such as auditory brainstem response (ABR) and acoustic reflex testing may be inadequate tools to assess peripheral auditory function when significant brainstem injury has occurred. Determination of peripheral hea...

The objective of this work is to study the influence of the moulding conditions of manufacture on the mechanical behaviour of the composites, when which they are submitted to mechanical loading. In order to evaluate the quality of interfacial adhesion, two non-destructive testing procedures were combined. Laser ultrasonic was employed to evaluate the state of the composite microstructure depend...

Acoustic Emission (AE) Technique is the only Non Destructive Testing (NDT) method that can be thought of to be used as an online monitoring tool for detection, location and characterization of various kinds of active defects during any process. An effective approach of quality control is defect detection during welding process itself rather than by NDT of component after welding. Weld defects g...

Acoustic emission technology relies on detecting and converting elastic (acoustic) waves from solids undergoing internal structural irreversible changes into electrical signals. This technique represents a non-destructive testing method used in industrial fields such as weld monitoring, proof testing, flaw detection of pressure vessels. In this study, the applicability acoustic for monitoring d...

Vibro-acoustography is an ultrasound based imaging modality that can visualize normal and abnormal soft tissue through mapping the acoustic response of the object to a harmonic radiation force at frequency Δf induced by focused ultrasound. In this method, the ultrasound energy is converted from high ultrasound frequencies to a low acoustic frequency (acoustic emission) that is often two orders ...

Acoustic emission activity produced by unrestrained drying shrinkage of an early age normal strength concrete specimen was measured with an array of fourteen broad-band high-fidelity acoustic emission sensors. The specimen was continuously monitored for 17 days, and full waveforms of the acoustic emissions were recorded throughout this time period. We present the source locations in three dimen...