SrBi 4 Ti 4 O 15 ceramics were prepared via ordinary firing (OF) and hot forging (HF). Characterization using scanning electron microscopy and X-ray diffractometry shows platelike grains that were highly oriented (F = 0.95) after hot forging. Ferroelectric, dielectric, and piezoelectric characterizations revealed that polarization reorientation was restricted to the ab plane of the orthorhombic structure, parallel to the (Bi 2 O 2 ) 2+ layers. The thickness coupling factor for OF samples was only half that for HF samples oriented parallel to the HF direction (in the ab-plane), as a consequence of poling restrictions in randomly oriented grains.

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This study proposes a new method to obtain hydrophobicity classification (HC) in high voltage polymer insulators. In the method mentioned, the HC was analyzed by fractal dimension (fd) and its processing time was evaluated having as a goal the application in mobile devices. Texture images were created from spraying solutions produced of mixtures of isopropyl alcohol and distilled water in proportions, which ranged from 0 to 100% volume of alcohol (%AIA). Based on these solutions, the contact angles of the drops were measured and the textures were used as patterns for fractal dimension calculations.

Many researchers have been studying coconut fibers due to its being a natural and renewable source. Moreover, coconut waste is discarded in landfills, bringing environmental problems because this material, although natural, takes time to be degraded. The use of natural fibers such as coconut fibers has become industrially attractive because of its low cost, high availability and desired mechanical properties for some applications, such as panels, ceilings, and partition boards and automotive components. In this study, polymers with coconut fiber composites were made by injection processing and mechanically characterized by tensile and dynamic testing. The fiber content ranged from 0 to 30wt%. The results of Young's modulus obtained from both methods decreased with fiber load and were nearly identical up to 15wt% of fiber, about 1.1GPa, but the increase in fiber concentrations distinctly interferes with each method in the values obtained.

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