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Civil engineering is not just about construction of buildings, towers, bridges etc. but also of their caring and maintenances. For this purpose all the constructed structures have to be monitored for their structural health in terms of damage detection, severity of damage etc., collectively called structural health monitoring (SHM) of structures in civil engineering. For SHM, electromagnetic impedance (EMI) technique is one of the best methods of NDTs being used in the field of civil engineering. EMI uses lead zirconate titnate (PZT) as its piezoelectric component for the purpose of measurement. PZT based devices are widely used in civil engineering. There is a huge demand for health monitoring now a days and to full fill those demands of health monitoring, PZT is one among the most reliable and cost efficient material. Piezoelectric sensor can be used to measure changes in acceleration, strain, pressure and to ensure the better safety measures. These PZT based sensors can be used for predicting the natural disasters like earthquake that helps to save the thousands of lives and can decrease property lose. The piezoelectric sensors can be used to monitor the civil structure which helps an engineer to analyses the characteristics of that structure. It is also used for collecting the data of force that is being exerted on the ground by the building, temperatures and pressure differences in environment etc. Damage detection is a technique that is used to monitor the civil structure, this can improve safety and ensure durability, and for concrete structures, damage detection plays an important role. For the purpose of SHM and damage detection PZT based sensors can be used. For civil engineering applications, PZT-cement based composites have been developed. The concrete and host structure such PZT-cement based composites shows better matching when compared to normal or other piezoelectric ceramics. In this review work we have discussed about SHM/Damage detection, Vibrational control, PZT embedded cement composites and PZT embedded in concrete. [ABSTRACT FROM AUTHOR]

The polycrystalline sample of (Bi0.5Li0.5)(Fe0.5Nb0.5)O3was prepared by a solid-state reaction method. Preliminary X-ray structural analysis of the sample suggests the formation of a tetragonal phase with a new unit cell configuration. Dielectric, electrical, impedance and modulus properties of the material were investigated in a wide range of temperature (25–500 °C) and frequency (1 kHz–1 MHz). Two dielectric anomalies observed at 295 °C and 400 °C clearly suggest the existence of magnetic phase transition and two relaxation processes in the system. Dielectric properties have greatly been improved on addition of LiNbO3to BiFeO3. The appearance of a hysteresis loop at room temperature confirms the ferroelectric properties of the material. The nature of the Nyquist plot confirms the presence of both bulk and grain boundary effects in the material. The ac conductivity was found to obey Jonscher's power law. The dc conductivity variation with temperature follows the Arrhenius equation. The induced voltage changes with the applied magnetic field, showing that the sample is multiferroic. [ABSTRACT FROM AUTHOR]

Tungsten–bronze polycrystalline ceramic Li2Pb2Dy2W2Ti4V4O30was prepared by mixed-oxide method. The preparation conditions were optimized by thermogravimetry analysis and repeated firing. Room-temperature structural analysis confirms the formation of the compound in single phase (orthorhombic). Studies of dielectric parameters () of the compound with temperature at different frequencies suggest the existence of phase transition in the compound. The existence of ferroelectric property (based on dielectric anomaly) of the material was confirmed by polarization study. [ABSTRACT FROM PUBLISHER]

The polycrystalline sample of Li2Pb2Nd2W2Ti4Nb4O30was prepared by a solid-state reaction technique. Room temperature X-ray structural analysis confirms the formation of a single-phase compound. The morphology of the sintered sample recorded by scanning electron microscope exhibits a uniform grain distribution. Detailed studies of the nature of variation of dielectric constant, tangent loss, and polarization with temperature and frequency confirmed the existence of ferroelectricity in the material at room temperature. The temperature and frequency dependence of impedance parameters (impedance, modulus, etc.) of the material exhibits a strong correlation of its microstructure (i.e., bulk, grain boundary, etc.). Furthermore, the temperature dependence of DC conductivity shows a typical Arrhenius behavior of the material. The nature of variation of pyroelectric coefficient and current with temperature suggests that material has good pyroelectric properties useful for pyroelectric detector. [ABSTRACT FROM AUTHOR]

The core-shell Zn-ZnO nanostructures were fabricated from Zn-powder embedded in graphite (i.e. carbon matrix) in a thin-films form by an inexpensive vacuum arc technique followed by laser ablation. The grazing incidence X-ray diffraction pattern shows that intensity of Zn-peak decreases, and subtle ZnO-peak increasing with the increase in laser power. The high resolution transmission electron microscopic study clearly exhibits the formation of a core-shell nanostructure as fabricated by laser ablation. The emission characteristics of laser ablated (with different powers) samples show a strong exciton peak at 388 nm, and a few more weak peaks (due to weak defect states in the visible range). The optical absorption spectra were obtained from the excitonic peaks (from 344 nm to 317 nm) on decreasing laser power. These peaks occur due to the coupling of exciton absorption (from ZnO shell layer) and core metal interband absorption. The Zn-ZnO core-shell nanostructure is useful for nanophotonic applications. [ABSTRACT FROM AUTHOR]

Polycrystalline samples of MgTeO 3 were prepared by a conventional solid-state reaction technique at 750°C. An X-ray powder diffraction (XRD) technique was used to check the formation of a single phase MgTeO 3 compound with cell parameters a = 4.421(1) Å, b = 14.916(1) Å and c = 12.289(1) Å in an orthorhombic crystal system. Detailed studies of dielectric and electrical properties show that the compound has a sharp ferroelectric phase transition of first order. [ABSTRACT FROM AUTHOR]