We describe an experimental setup specifically designed for measuring the ultrasonic transmission through liquid foams, over a broad range of frequencies (60-600kHz). The question of determining the ultrasonic properties of the foam (density, phase velocity and attenuation) from the transmission measurements is addressed. An inversion method is proposed, tested on synthetic data, and applied to...

In indoor context awareness applications the location of people, devices or objects is often required. Ultrasound technology enables high resolution indoor position measurements. A disadvantage of stateof-the-art ultrasonic systems is that several base stations are required to estimate 3D position. Since fewer base stations leads to lower cost and easier setup, a novel method is presented that ...

ultrasonic machining (usm) is a mechanical material removal process used to erode holes and cavities in hard or brittle work pieces by using shaped tools, high-frequency and an abrasive slurry. this paper addresses the concept and development of an expert system (es) for hard and brittle material, such as glass, quartz, diamond, carbides, semi conducting materials, ceramic and graphite which ca...

Removal of carbonate impurities in sedimentary phosphate is one of the most important issues in the industry. Poor selective flotation of those ores is due to the similarity of Physico-chemical surface properties, solubility and electrokinetic characteristics of sparingly soluble phosphate and carbonate minerals. In this study, the effect of ultrasonic irradiation as a pretreatment method o...

We present the results of experimental investigation of ultrasonic washing of textiles. The results demonstrate that cavitation bubbles oscillating in acoustic fields are capable of removing soils from textiles. Since the washing performance is mitigated in a large washing bath when using an ultrasonic transducer, we propose a novel washing scheme by combining the ultrasonic vibration with a co...

Time reversal is a very powerful method for focusing through complex and heterogeneous media and shows very promising results in biomedical applications. In this paper, we review some of the main applications investigated during the past decade. An iterative implementation of the time-reversal process allows tracking gallstones in real time during lithotripsy treatments. In this application dom...

Ultrasonic guided waves are used to detect the delamination between skin and honeycomb of a composite helicopter rotor blade. Theoretical work is carried out for guided waves in the trailing edge of a rotor blade, which is a multilayer composite skin/NOMEX half space structure. The dispersion relation is obtained with the global matrix method. Theoretically driven experiments are conducted on a...

For analyzing partial discharge ultrasonic wave characteristic on typical defects in SF6 gas insulation switchgear (GIS), a 110 kV GIS was taken as an object to design and simulate the typical partial discharge models in GIS There are point electrode model on bus and cavity of GIS, floating electrode model, air interstice model in insulator, metal particle and iron core electromagnetic shock mo...