PHARMACOGNOSTICAL STUDIES AND PRELIMINARY PHYTOCHEMICAL INVESTIGATION ON THE BARK OF BAUHINIA VARIEGATA (CAESALPINIACEAEA)

Bauhinia variegata (Family - Caesalpiniaceaea) is a medium-sized, deciduous tree, found throughout India, ascending to an altitude up to 1800m in Himalayas. The objective of the study was to develop various standardization parameters for the evaluation of Bark of this plant. Microscopy, powder characteristics of bark were observed and results were recorded. Physicochemical analysis such as extractive value includes petroleum ether, ethanol, ethyl acetate and aqueous soluble extractive values of 2.88, 6.86, 2.96, and 8.88% w/w respectively; extracts were analysed by chemical test and showed presence of flavonoids, tannins, steroids and triterpenoids etc. The preliminary phytochemical investigation indicated presence of tannins, carbohydrates, flavenoieds and steroids. The results obtained from standardization of bark established the macro and microscopical parameters, physicochemical parameters, TLC profiles that characterize the genuine plant drug (B.variegata) so these parameters are useful for quick identification of drug and are particularly useful in the case of powdered materials

Piezoelectric Properties of Ta (≤ 5 (mole)%) Doped in Na0.685K0.315NbO3

To explore the piezoelectric potential of Ta doping on the MPB- like composition Na0.685K0.315NbO3, ceramic pellets of Na0.685K0.315Nb1-yTayO3 (y ≤ 0.05) were arranged by solid-state reaction method. For piezoelectric measurements, sintered pellets were electroded, in parallel capacitor configuration, with silver coating deposited by direct current (dc) magnetron sputtering of a silver target. Polarization and piezoelectric parameters were measured using a ferroelectric (PE- loop tracer) and piezo- meter (AixACCT Systems, GmbH). Composition (y) variation of remnant polarization, coercive field, converse piezoelectric coefficient (d*33), and polarization current measurements were carried out in the prepared compositions. The remnant polarization (Pr) is 18.439 μC/cm2 with a coercive field (Ec) of 8 kV/cm for NKNT single crystals. d*33 was observed 300.76 pm/V for y = 0.04 at the applied field of 22kV/cm

Electrical Properties of lead free ceremics Na1−XKxNbO3, at x=0.305.

By solid state reaction method, ceramic pellets of Na0.695K0.305NbO3 have been prepared. X-ray- diffraction, Piezo properties, scanning electron microscope, and temperature dependence of dielectric constant and loss tangent of the prepared samples have been studied. It has been observed that, at the transition temperature, dielectric constant peak shifts to lower temperature, and the dielectric constant and loss tangent peak heights decrease, with  increasing frequency, and show three structural phase transitions

Dielectric properties of Na1−xKxNbO3, near x = 0.475 morphotropic phase region

11-17Sodium-potassium niobate (Na1−xKxNbO3) ceramic pellets, with x = 0.465, 0.470, 0.475, 0.480 and 0.485, were prepared by solid state reaction method with double sintering. With varying composition (x), the dielectric properties, X-ray diffraction peaks shifting pattern, in this system. Among the prepared compositions, a break in the X-ray diffraction peaks shifting tendency; minimum dielectric constant, loss tangent and dielectric conductivity indicate a morphotropic phase transition type behavior, at the composition with x = 0.475

Electrical Properties of lead free ceremics Na1−XKxNbO3, at x=0.305.

783-786By solid state reaction method, ceramic pellets of Na0.695K0.305NbO3 have been prepared. X-ray- diffraction, Piezo properties, scanning electron microscope, and temperature dependence of dielectric constant and loss tangent of the prepared samples have been studied. It has been observed that, at the transition temperature, dielectric constant peak shifts to lower temperature, and the dielectric constant and loss tangent peak heights decrease, with increasing frequency, and show three structural phase transitions

Piezoelectric Properties of Ta (≤ 5 (mole)%) Doped in Na_0.685K_0.315NbO₃

740-743To explore the piezoelectric potential of Ta doping on the MPB- like composition Na0.685K0.315NbO3, ceramic pellets of Na0.685K0.315Nb1-yTayO3 (y ≤ 0.05) were arranged by solid-state reaction method. For piezoelectric measurements, sintered pellets were electroded, in parallel capacitor configuration, with silver coating deposited by direct current (dc) magnetron sputtering of a silver target. Polarization and piezoelectric parameters were measured using a ferroelectric (PE- loop tracer) and piezo- meter (AixACCT Systems, GmbH). Composition (y) variation of remnant polarization, coercive field, converse piezoelectric coefficient (d*33), and polarization current measurements were carried out in the prepared compositions. The remnant polarization (Pr) is 18.439 μC/cm2 with a coercive field (Ec) of 8 kV/cm for NKNT single crystals. d*33 was observed 300.76 pm/V for y = 0.04 at the applied field of 22kV/cm