Open access
Submitted: 07 February 2012 Published: 01 August 2012
DOI: 10.5772/45791
From the Edited Volume
Edited by Joao Paulo Carmo and Joao Eduardo Ribeiro
Submitted: 07 February 2012 Published: 01 August 2012
© 2012 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.