Synthesis and characterization of (68-x) CuO – xV<inf>2</inf>O<inf>5</inf> – 32TeO<inf>2</inf> (x = 0–68 mol%) and (35-x) CuO – xV<inf>2</inf>O<inf>5</inf> – 65TeO<inf>2</inf> (x = 0–35 mol%) glasses: Conduction mechanism, structure and EPR study

In this work, two series of glasses, i.e. (68-x) CuO – xV2O5 – 32TeO2 (x = 0–68 mol%, Te32 series) and (35-x) CuO – xV2O5 – 65TeO2 (x = 0–35 mol%, Te65 series), were synthesized by the melt-quenching method and subjected to physical, thermal and electrical characterization. Their vitreous nature was confirmed by X-Ray diffraction and differential scanning calorimetry, while their structural units were determined by Raman spectroscopy. CuO substitution by V2O5 led to a decrease in density and glass-transition temperature, together with a conductivity increase. Conduction mechanism was interpreted as mainly due to small polaron hopping from the lower (V4+) to the higher (V5+) vanadium valence states. Te32 glasses, possessing the highest electronic conductivities (ranging from 2 E−4 to 5 E−7 Ω−1 cm−1), were investigated by the Electron Paramagnetic Resonance technique, in order to more deeply analyze their structure-conductivity correlation. Particularly, the observed signals were determined to consist in a superposition of a first line due to paramagnetic Cu2+ ions and a second line due to exchange-coupled CuO clusters. Differences in the spectra were determined between samples with higher (i.e. 20-30 mol%) Cu2+ concentrations and samples with lower Cu2+ concentrations, suggesting they are located in different local environments. Finally, it was found that the Cu2+ ions are not involved in the process of electron transfer

Insects and globalization: sustainable control of exotic species in Italian agro-forestry ecosystems

One of the negative consequences of globalization is the increased introduction of exotic pests into new areas. Italy, in particular, is at high risk of introduction, because of its geographical position and climate, which allows the settlement of (even subtropical) exotic species. In this context, native natural enemies may play a major role in the biological control of exotic species. The mechanisms involved in adaptation processes, which are crucial in studies of biological invasions, are only partially known. A joint effort by researchers operating in Italy and abroad is needed to deeply investigate this phenomenon and to develop appropriate strategies for sustainable control of exotic species. The present work illustrates the objectives and preliminary results of the project \u201cInsects and globalization: sustainable control of exotic species in agro-forestry ecosystems (GEISCA)\u201d focused on control of exotic species by native entomophagous insects. The overall goal of the project is to gain, at the end of three years, useful knowledge on the development of appropriate procedures for sustainable control of target pest species