Especially for ageing aircraft the development of fatigue cracks at fastener holes due to stress concentration and varying loading conditions constitutes a significant maintenance problem. High frequency guided waves offer a potential compromise between the capabilities of local bulk ultrasonic measurements with proven defect detection sensitivity and the large area coverage of lower frequency ...

Gelamo et al., on page 331 of this issue, present the elegant work entitled “Effects of reprocessing on chemical and morphological properties of guide wires used in angioplasty” [1], in which they describe significant morphological changes after washing the guide wires once or twice using ultrasonic vibration and enzymatic detergent, and no significant changes when sterilized with ethylene oxid...

Purpose. To develop methods for spatial control over ultrasonic cleaning by using phased array of radiators. simulate the process developed to prove their effectiveness. Methodology. Application as a basic radiator enables redistribution intensity in bath increasing it most contaminated zones cleaned object. Geometric and physical laws provide analytically defined parameters beam. Findings. The...

The condition of the surface through which a sound beam enters a material is an important factor in ultrasonic non-destructive testing(1). Detection of discontinuities such as cracks, voids and porosities in castings is greatly affected by the extent of roughness. Increased roughness reduces the transmitted energy of the sound beam and this, in turn, reduces the amplitude of the received signal...

We address the problem of improving the spatial resolution of ultrasound images through blind deconvolution. The ultrasound image formation process in the RF domaim can be expressed as a spatio-temporal convolution between the tissue response and the ultrasonic system response, plus additive noise. Convolutional components of the dispersive attenuation and aberrations introduced by propagating ...

Submarine groundwater discharge can significantly influence the near shore transport of chemicals into surface waters. Quantification of the sources and rates of such discharge is critical to development of management strategies. Quantification requires a groundwater seepage meter that provides continuous measurements at high resolutions over an extended period of time. An ultrasonic flow meter...

PURPOSE This study investigated the effectiveness of a clamp method combined with bipolar coagulation for anatomical hepatectomy in the treatment of hepatocellular carcinoma (HCC). METHODS In this prospective case-control study, three liver dissection methods were used: clamping combined with bipolar electric coagulation (group A), CUSA (Cavitron ultrasonic surgical aspirator) (group B), and ...

The purpose of this study was to monitor the setting behaviour and elastic modulus of luting cements using an ultrasonic device. The ultrasonic equipment comprised a pulser-receiver, transducers and an oscilloscope. The transit time through the cement disk was multiplied by the thickness of the specimen, and the sonic velocity within the material was then calculated. The sonic velocities of the...

The work reported here is the development of a first prototype portable ultrasonic inspection instrument based on EMAT (electromagnetic acoustic transducer) technology. The goal was to demonstrate EMAT inspection capabilities for small-size flaws in metal parts and to build a self-contained NDE unit that had a high degree of signal processing on-board so that human interpretation was minimized....

B-scan ultrasonography is now widely used in ophthalmology for investigation of orbital lesions and posterior segment lesions when direct visualisation is prevented by opacity in the ocular media. Most authors have concentrated on ultrasonic demonstration of posterior segment lesions, but the separation of diseases of anterior and posterior segments is largely artificial. The present study has ...