Abstract: Device and method for detecting a defect in a workpiece with a broadband transducer (10), a driving circuit connected to the transducer to operate the transducer in a actuator mode, a signal output circuit connectable to operate in a sensor mode, a control for selectively connecting the transducer to the driving circuit or signal output circuit wherein the driving circuit includes at least a pair of oscillators for generating signals of at least frequencies F1 and F2 and a summer for summing the signals to provide a driving circuit for the transducer.

Abstract: Device and method for detecting a defect in a workpiece with a broadband transducer (10), a driving circuit connected to the transducer to operate the transducer in a actuator mode, a signal output circuit connectable to operate in a sensor mode, a control for selectively connecting the transducer to the driving circuit or signal output circuit wherein the driving circuit includes at least a pair of oscillators for generating signals of at least frequencies F1 and F2 and a summer for summing the signals to provide a driving circuit for the transducer.

Abstract: Gallium nitride is grown by plasma-assisted molecular-beam epitaxy on (111) and (001) silicon substrates using hafnium nitride buffer layers. Wurtzite GaN epitaxial layers are obtained on both the (111) and (001) HfN/Si surfaces, with crack-free thickness up to 1.2 Om. However, growth on the (001) surface results in nearly stress-free films, suggesting that much thicker crack-free layers could be obtained.

Abstract: A headliner for a vehicle and a method of manufacturing the same is provided. The method includes providing vacuum forming equipment including upper and lower mold halves, providing thermoplastic material including a top and an independent bottom layer, and placing the top and bottom layers into the vacuum forming equipment between the upper and lower mold halves. The method further includes substantially sealing the upper and lower mold halves from atmosphere, joining the top and bottom layers together to form an integral headliner, and applying vacuum to the top and/or bottom layers at predetermined locations so as to form cavities between the top and bottom layers. The headliner made by the aforementioned method includes a plurality of surface contours on its top and/or bottom layers defining convex and concave members for absorption of impact energy during a crash.

Abstract: A seismic processing apparatus comprises a plurality of processing modules (12), each module comprising a transputer (T) and a transversal filter (TF) with these transputers of the modules connected in a linear array by their links. The apparatus is able to carry out real-time demultiplexing of the seismic data from a plurality of receiver channels, and is able to carry out a number of other processing functions in the field, e.g. common depth point stacking, summing, correlation, convolution and two dimensional Fourier transforms.