Effect of the metal in the production of pollutants during the decomposition of two types of electric wires

Support for this work was provided by the Generalitat Valenciana (Spain) with projects PROMETEO/2009/043/FEDER, and by the Spanish MCT CTQ2008-05520.

Decomposition of two types of electric wires considering the effect of the metal in the production of pollutants

Combustion runs at 700 °C in a horizontal laboratory furnace were carried out on two different electric wires (PVC and halogen-free wire). Tests were performed in the presence and in the absence of the metal conductor of the wires. The analyses of the polycyclic aromatic hydrocarbons (PAHs), chlorobenzenes (CBzs), chlorophenols (CPhs), mono- to octa-chlorodibenzo-p-dioxin and dibenzofurans (PCDD/Fs), and dioxin-like PCBs are shown. Regarding semivolatile compounds, PAHs production decreases in the presence of metal, while a higher amount of chlorinated compounds are emitted. Respect to the PCDD/Fs, the PVC wire in the presence of metal presents the highest emission, with a much more emission of furans than dioxins. The maximum emission is with 2 or 3 chlorine atom PCDD/Fs. PCBs emission correlates with PCDD/F production and represents 3–4% of total toxicity, determined by using WHO2005 factors.

Relationship between sociometric types and academic achievement in a sample of compulsory secondary education students

The aim of this study was to analyse the relationship between sociometric types, behavioural categories and academic achievement in a sample of 1,349 compulsory secondary education students (51.7% boys), ranging in age from 12 to 16 years. The students’ sociometric identification was performed by using the Programa Socio and academic performance was measured by school marks provided by teachers in the subjects of Spanish language, mathematics and average academic performance. The results show that sociometric types were significant predictors of academic achievement, as students who were rated positively by their peers (popular, leaders, collaborators and good students) were more likely to have high academic achievement (in mathematics, Spanish language and average academic achievement) than students rated negatively by peers (rejected-aggressive, rejected-shy, neglected and bullies).