Research methods and didactic to carry out an essay about history of schooling

El alumnado de primer curso del Doble Grado en Educación Primaria y Estudios ingleses, de nueva implantación en la Universidad de Málaga, accede a la asignatura de Historia de la Escuela sin el más mínimo conocimiento de la cuestión, es decir, partiendo de cero, y sin las herramientas crítico-analíticas básicas para aprobar la asignatura, dada su procedencia de un sistema basado en la memorización acrítica. Este material docente universitario pretende ayudar a que aprueben la asignatura

Multimodal electromechanical model of piezoelectric transformers by Hamilton's principle

This work deals with a general energetic approach to establish an accurate electromechanical model of a piezoelectric transformer (PT). Hamilton’s principle is used to obtain the equations of motion for free vibrations. The modal characteristics (mass, stiffness, primary and secondary electromechanical conversion factors) are also deduced. Then, to illustrate this general electromechanical method, the variational principle is applied to both homogeneous and nonhomogeneous Rosen-type PT models. A comparison of modal parameters, mechanical displacements, and electrical potentials are presented for both models. Finally, the validity of the electrodynamical model of nonhomogeneous Rosen-type PT is confirmed by a numerical comparison based on a finite elements method and an experimental identification