Effect of cylindrical filler aggregation on the electrical conductivity of composites

This work reports on the effect of carbon nanotube aggregation on the electrical conductivity and other network properties of polymer/carbon nanotube composites by modeling the carbon nanotubes as hard-core cylinders. It is shown that the conductivity decreases for increasing filler aggregation, and that this effect is more significant for higher cylinder volume fractions. It is also demonstrated, for volume fractions at which the giant component is present, that increasing the fraction of cylinders within clusters leads to a break of the giant component and the formation of a set of finite clusters. The decrease of the giant component with the increase of the fraction of cylinders within the cluster can be related to a decrease of the spanning probability due to a decrease of the number of cylinders between the clusters. Finally, it is demonstrated that the effect of aggregation can be understood by employing the network theory.

Inv(f)erno da Universidade de Verão

Despesa em educação é investimento constitucional: art.s 75º e 76º da Constituição. Como referiu o director da Revista Ensino Superior, nº 53, pp. 4-5, ex-presidente do Sindicato Nacional do Ensino Superior, Professor da Faculdade de Economia da Universidade de Coimbra, Doutor Paulo Peixoto, o ensino superior tornou-se em grande parte uma “máquina de triturar intelectuais”. A tentativa de impor uma mentalidade única pode provocar a destruição da génese da própria universalidade. § Spending on education is constitutional investment: Articles 75 and 76 of the Constitution. As the director of the Journal of Higher Education, # 53, pp. 4-5, former president of the National Union of Higher Education, Professor of Economics, University of Coimbra, Dr. Paulo Peixoto, higher education has become largely an 'intellectual grinding machine. "The attempt to impose a single mindset may cause the destruction of the very universality genesis.