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.

Política, eleições e corrupção económica…

Os partidos e candidatos que terão os melhores resultados nas próximas eleições legislativas a realizar em Portugal – que, com elevado grau de probabilidade, serão antecipadas – serão aqueles que melhor consigam convencer os votantes em geral de que a retribuição, prevenção e restauração dos crimes e ilícitos de corrupção, e da criminalidade económica e social em geral, terão um tratamento desta vez eficaz em concreto; Abstract: The parties and candidates who have the best results in the upcoming legislative elections in Portugal - which, with high probability, will be early - will be those who best can convince the general voting that the compensation, prevention and restoration of crimes and illegal corruption, and economic and social crime in general, receive treatment this time effective in concrete.

Survival Analysis Employed in Predicting Corporate Failure: A Forecasting Model Proposal

In face of the current economic and financial environment, predicting corporate bankruptcy is arguably a phenomenon of increasing interest to investors, creditors, borrowing firms, and governments alike. Within the strand of literature focused on bankruptcy forecasting we can find diverse types of research employing a wide variety of techniques, but only a few researchers have used survival analysis for the examination of this issue. We propose a model for the prediction of corporate bankruptcy based on survival analysis, a technique which stands on its own merits. In this research, the hazard rate is the probability of ‘‘bankruptcy’’ as of time t, conditional upon having survived until time t. Many hazard models are applied in a context where the running of time naturally affects the hazard rate. The model employed in this paper uses the time of survival or the hazard risk as dependent variable, considering the unsuccessful companies as censured observations.