This paper presents theoretical and experimental research concerning the manufacture of an intelligent piezoceramic sensor for non-destructive tests (NDT) applications in non-metallic materials. The non-destructive impact-echo method is a suitable technique for the flaw detection in the material structure, based on stress wave propagation. A transient stress pulse is introduced into the sample by an impact shock wave hammer placed on the element

Super – fine calcium carbonate was prepared by double jet precipitation method. The values of the estimated kinetics parameters show that nucleation is the dominant mechanism in all experimental runs.

This paper presents theoretical and experimental research concerning the manufacture of an intelligent piezoceramic sensor for non-destructive tests (NDT) applications in non-metallic materials. The impact-echo method is suitable for determination of flaw in the material structure, based on stress wave propagation. This method could be applied for non-metallic materials with rugged and nonhomogeneous structures. The active element of the intelligent

Paper presents aspects concerning the behaviour of PZT piezoceramics at low power electron irradiation. The PZT samples were irradiated into a linear accelerator of electrons with different election doses, namely: 10 kGy; 15 kGy; 20 kGy; 25 kGy. These ceramics change slightly their pellet-winces after low power electron irradiation, but at 25kGy the piezoelectric charge and voltage constants increase more. However, PZT partial decomposition could

Precipitated calcium carbonate as vaterite and small amounts of calcite, with submicron sizes was obtained by a two stages reaction. In the first stage, the limestone was transformed with carbon dioxide in calcium bicarbonate in the absence and the presence of an ultrasonic applied field (35kHz and 0.52 W/cm2). The ultrasonic intensity and specific power, the device immersion depth in column suspension and the cavitation was observed to accelerate

Precipitated calcium carbonate as vaterite and small amounts of calcite, with submicron sizes was obtained by a two stages reaction. In the first stage, the limestone was transformed with carbon dioxide in calcium bicarbonate in the absence and the presence of an ultrasonic applied field (35kHz and 0.52 W/cm2). The ultrasonic intensity and specific power, the device immersion depth in column suspension and the cavitation was observed to accelerate