A technique known as Time Delay Spectrometry (TDS), which has been used at JPL for ultrasonic tissue characterization, has promise for similar application in materials characterization as well. This technique differs from the approaches based on pulse-echo techniques which are used by other workers. Time Delay Spectrometry operates in the frequency domain directly. The transducer is excited by ...

The purpose of this presentation is to introduce to the NDE community an empirical modeling technique which has been under development during the past thirteen years and applied particularly to many problem areas in the last five. The application of interest to today's audience is that of classification of flaw geometry from ultrasonic signals. Disciplines Materials Science and Engineering | St...

First proposed in the 1970s for non-destructive testing, the modern reincarnation of photoacoustic microscopy (PAM) has major impact in bio-medicine, spanning a wide range of applications from flow cytometry and cancer research to ophthalmology, neuroimaging and cardiovascular diagnostics. The hybrid nature of PAM combining optical excitation and acoustic detection provides it with a number of ...

PURPOSE Ultrasonic lithotriptors are commonly used to fragment and remove stones during percutaneous nephrolithotomy. To date a comparative assessment of current units has not been accomplished without potential operator bias. An objective testing environment is required for optimal appraisal of the efficiency of ultrasonic lithotriptors. MATERIALS AND METHODS An in vitro test system was devi...

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...