Carbon Nanofiber Type and Content Dependence of the Physical Properties of Carbon Nanofiber Reinforced Polypropylene Composites

The variation of the physical properties of four differ- ent carbon nanofibers (CNFs), based-polymer nano- composites incorporated in the same polypropylene (PP) matrix by twin-screw extrusion process was investigated. Nanocomposites fabricated with CNFs with highly graphitic outer layer revealed electrical isolation-to-conducting behaviors as function of CNF’s content. Nanocomposites fabricated with CNFs with an outer layer consisting on a disordered pyro- litically stripped layer, in contrast, revealed better mechanical performance and enhanced thermal sta- bility. Further, CNF’s incorporation into the polymer increased the thermal stability and the degree of crystallinity of the polymer, independently on the filler content and type. In addition, dispersion of the CNFs’ clusters in PP was analyzed by transmitted light opti- cal microscopy, and grayscale analysis (GSA). The results showed a correlation between the filler concentration and the variance, a parameter which measures quantitatively the dispersion, for all composites. This method indicated a value of 1.4 vol% above which large clusters of CNFs cannot be dispersed effectively and as a consequence only slight changes in mechanical performance are observed. Finally, this study establishes that for tailoring the physical properties of CNF based-polymer nanocomposites, both adequate CNFs structure and content have to be chosen.

Crime Económico Não Esquecendo Crime Clássico

Fala-se hoje em dia muito e bem no crime económico e social. Crime de colarinho branco. Também crime da ocupação, profissional ou amadora. Falamos sobre direito penal económico e social. Fraude fiscal, corrupção, branqueamento de capitais, crimes da bolsa, abuso de posição dominante, etc.. Contudo, isto não podemos esquecer o crime clássico, furtos, roubos, danos, ofensas à integridade física, violação, tortura, ameaças, ofensas à honra, injúria ou difamação, abuso sexual (não apenas de crianças), violação, homicídios domésticos ou entre estranhos, etc.. § There is talk nowadays long and hard in the economic and social crime. White collar crime. Also crime of occupation, professional or amateur. We talk about economic and social criminal law. Tax fraud, corruption, money laundering, stock crimes, abuse of dominant position, etc .. However, this can not forget the classic crime, theft, robbery, damage, bodily harm, rape, torture, threats, insults to honor, slander or defamation, sexual abuse (not just children), rape, domestic or among strangers murders, etc ..