Estudo da resistência à corrosão de ligas Ni-Cr-Mo-Ta E Ni-Cr-Mo-W em solução NaF 0,08 mol/L, pH 4,7 para aplicações odontológicas

A large number of metal alloys are used in Dentistry for the manufacture of fixed and removable dentures. In the oral cavity, these structures are exposed to a chemically aggressive medium, like saliva and mechanical efforts, like mastication. In addition, acidic solutions containing fluoride ions are also frequently used in dental treatments to prevent dental plates and decays development. In this context, it was considered important to investigate the influence that a fourth element could exert when added to the ternary alloy Ni-Cr-Mo, largely used in Brazil. Therefore, electrochemical tests were done to evaluate the resistance to corrosion of quaternary alloy 65Ni-25Cr-5Mo-5Ta and 65Ni-25Cr-5Mo-5W in NaF solution 0,08mol / L, pH = 4.7. For greater understanding the microstructure and morphology of alloys were studied, through metallographic analysis, using optics microscopy and electron microscopy scanning. For the electrochemical tests were applied techniques traditionally used in corrosion researches, such as: potential measures in open circuit (OCP) and cyclic polarization (CP). It was found that both quaternary alloys showed very similar results. Comparing these quaternary alloys with the ternary 65Ni-25Cr-10Mo, it was found that the quaternary alloys exhibit greater resistance to corrosion, in other words, less passivation current density than the ternary alloy, showing that it is advantageous to add a fourth element in the alloy

O papel dos conflitos no desenvolvimento do juízo moral em crianças da educação infantil

This research sets up as a reflection on the development of moral judgment in children from 04, 05 years of the Early Childhood Education with the main theoretical reference the studies of Jean Piaget (1932/1994) on the subject. To this end, we conducted a case study in order to understand what types of conflicts that arise among children in the school of early childhood education and how the teacher seeks to solve them, or not assisting in promoting the moral autonomy of the small. Behaviors and conflicts observed were described and analyzed by correlating them to the practice of the teacher in the classroom that is the case study. We found that conflicts are avoided and unwanted by the teacher and, when they arise, are quickly resolved through attitudes centered educator without enable dialogue and reflection among the children involved. In this sense, we infer that the teaching practice focused on the development of moral judgment of children showed failure and ineffective. As a result of feedback from the first phase of this research we deem necessary to investigate about the training of teachers of early childhood education in relation to theories that deal with the development of moral judgment in children of this educational stage and identify the implications that such training reflects teacher practices in. We hope that by making such reflection can contribute to the debate on the need to educate morally in early childhood education, whose main objective is to promote the integral development of children