background: a comprehensive database, comprising geometry and properties of human teeth, is needed for dentistry education and dental research. the aim of this study was to create a three-dimensional model of human teeth to improve the dental e-learning and dental research.   methods: in this study, a cross-section picture of the three-dimensional model of the teeth was used. ct-scan images wer...

introduction: mandibular first molar is the most important tooth with complicated morphology. in finite element (fe) studies, investigators usually prefer to model anterior teeth with a simple and single straight root; it makes the results deviate from the actual case. the most complicated and time-consuming step in fe studies is modeling of the desired tooth, thus this study was performed to e...

This paper presents some implementation details of a threephase to three-phase matrix converter prototype. The bidirectional semiconductor switches were built using discrete IGBTs and fast diodes. Design aspects such as protection against overvoltage and short-circuit, commutation process Artigo submetido em 23/04/2010 (Id.: 1132) Revisado em 18/09/2010, 15/07/2011, 30/08/2011 Aceito sob recome...

Frequency-domain modeling is an effective technique in the dynamic analysis of power electronic converters-based systems. In this paper, a unified single-input single-output (SISO) loop gain for three-phase grid-tied voltage source converters (VSCs) under both symmetric and asymmetric AC grids presented, which facilitates physical measurement stability analysis. Based on linear-time-periodic (L...