Polycrystalline BaTiO 3 and Ba(Ti 0.96 SnxZr 0.04-x )O 3 ceramics (x = 0.02-0.04) were prepared by a combination of solid-state and mechanochemical process and characterized at room temperature by X-ray diffraction for phase composition. Their crystal structures were found to be of the cubic and tetragonal symmetries, respectively. The grain size and porosity which were determined using Field Emission Scanning Electron Microscope (FESEM) and densitometer, respectively showed decrease and increase of relative density respectively, with increase in doping concentration. The variations of dielectric constant and loss with frequency and temperature show a maximum dielectric constant of 1660 at room temperature for Ba(Ti 0.96 Sn 0.03 Zr 0.01 )O 3 . The remnant polarization (P r ) and coercive field (E c ) of BT were found to be 581.73 V/cm and 0.27 μC/cm 2 . Increase in Sn content led to an increase in Pr of 0.58, 3.07, 3.73 C/cm 2 , and Ec of 1766.8, 2855.7, 2661.1 V/cm, respectively and are expected to lead to a significant reduction in the thickness of the multilayer ceramic capacitors. Impedance spectroscopy of polycrystalline Ba (Ti 0.96 Sn 0.02 Zr 0.02 )O 3 in a wide frequency and temperature range showed Nyquist plots with presence of grain and grain boundary at 400 C and a negative temperature coefficient of resistance (NTCR) for Ba(Ti 0.96 Sn 0.02 Zr 0.02 )O 3 .The dielectric relaxation showed a non-Debye character.

The physical properties of briquettes made from rice husk and coconut shell in different ratios were evaluated based on their thermo-physical properties. The calculated calorific values of the rice husk and coconuts hell are 16.51 MJ/kg and 18.60 MJ/kg, with densities of 1.50 g/cm3 and 3.00 g/cm3, respectively. Coconut shell has lower moisture and ash content of 10% and 26%, respectively, before briquetting. Comparisons of the experimental and calculated calorific values of the briquettes (17 to 21 MJ/kg) showed that they are in agreement with those of the American Standard of Testing Materials (ASTM) and those reported in the literature. The results further showed that the calorific values of the five briquette ratios were not a function of their moisture and ash contents, rather their total carbon contents. The briquette at the ratio 90:10 of rice husk to coconut shell has the highest calorific value and implies that it has more heating advantages and will therefore be suitable as an alternative solid fuel.