Ferroelectric, dielectric and piezoelectric properties13; of Pb1x2013;xCex(Zr0.60Ti0.40)O3, 0 xA3; x xA3; 0.08

The ferroelectric, dielectric and piezoelectric13; properties of compositions Pb1x2013;xCex (Zr0.60Ti0.40)O3,13; (x = 0.0, 0.01, 0.02, 0.04, 0.06 and 0.08) are studied. The13; above compositions are prepared from their constituent13; oxides, calcined at 900 C for 4 h and various phases13; present are characterized by X-ray diffraction (XRD)13; technique. The above powders are uniaxially pressed into13; circular compacts, sintered at 1,250 C for 2 h, electroded,13; poled at 2 kV/mm D.C. voltage and their electrical properties13; are measured. The XRD analysis shows the presence13; of rhombohedral phase up to 2 mol% ceria while tetragonal13; phase found at higher concentrations. It is observed that13; the ferroelectric, dielectric and piezoelectric properties13; increase with the addition of ceria with a maximum at13; 2 mol% and then decreases. The higher piezo properties13; associated with low ceria concentration are attributed to13; rhombohedral phase

Stability boundary analysis of magnetohydrodynamic circulator for the intermediate heat transfer system of prototype gen IV sodium fast reactor

One of the most important parts in the development of generation IV nuclear reactors is safety. In the research on generation IV sodium???cooled fast reactors, magnetohydrodynamic (MHD) circulators have received attention for the stable transport of coolants. In this study, the stability of an MHD circulator was evaluated using a mathematical approach to obtain the critical value of the developed pressure. The critical developed pressure equation is a function of the flow rate and dimensionless parameters, which were derived from the theoretical model of the MHD circulator with a dimensionless scaled velocity, flow rate, and pressure. The stability conditions expressed using the critical value of the developed pressure and dimensionless parameters were investigated according to the changes in the main design variables of the MHD circulator. The relationships between the dimensionless parameters, stability, and main design variables constituting the stability boundary of the MHD circulator were analysed. The stability of the MHD circulator is considered safe when the stability criterion ?? is lower than 1. The geometrical variables such as the duct thickness or width of the flow gap and electrical variables such as the frequency were the main parameters affecting the flow stability in the MHD circulator

Design and preliminary test of an annular linear induction electromagnetic pump for a sodium-cooled fast reactor thermal hydraulic experiment

An annular linear induction electromagnetic pump (ALIP) with a flow rate of 2265L/min and a developed pressure of 4bar was designed and fabricated to test the performance of the components of a sodium-cooled fast reactor (SFR) in a sodium thermal hydraulic experimental loop. The design characteristic of the ALIP was calculated using the electrical equivalent circuit method typically used for analyzing linear induction machines. Preliminary tests, such as verification of the moving function using an annular Al pipe, were carried out. The linearity between the input voltage, current, and magnetic flux density was verified. The developed force demonstrated an increase proportional to the square of the input current, whereas the velocity was linearly proportional to the input current. The main design variables of the pump were calculated theoretically for the SFR thermal hydraulic experimental loop. The pump was optimized for the design variables including input frequency, and the characteristics of the optimized pump were compared with those of the pump at the commercially used frequency of 60 Hz