Bioindicator organisms: Heavy metal pollution evaluation in the Ionian Sea (Mediterranean Sea—Italy)

Trace metal concentrations of mercury, cadmium, lead and chromium in Patella caerulea, and Mullus barbatus were investigated to provide information on pollution of Ionian Sea, since these metals have the highest toxic potential. High chromium levels (0.47–0.97 g g^–1 ww) were registered in limpet samples collected from two station near the Gulf of Taranto, while elevated concentration of mercury (0.31–1.50 g g^–1 ww) were found in mullet specimens from Sicily. The metal concentrations recorded at the clean stations may be considered as useful background levels to which to refer for comparison within the Mediterranean area. On the contrary, the high levels of chromium and mercury found respectively in the areas near the Gulf of Taranto and at Capo Passero being of concern in terms of environmental health need frequent monitoring.     

Spectral cullet classification in the mid-infrared field for ceramic glass contaminants detection.

The presence of glass-like contaminants inside waste glass products, usually resulting from both industrial and differentiated urban waste collection, has greatly increased in recent years, due to the introduction to the market of a large amount of goods manufactured from ceramic glass. The presence of contaminants in the glass recycling streams reduces product quality and increases production costs. The detection of ceramic glass detection is an unresolved problem, as such material looks like normal glass and can only be detected by trained personnel. In this study an innovative approach to ceramic glass recognition, based on the spectral signature in the mid-infrared (MIR) field, was proposed and investigated. The study specifically addressed the spectral characterization of glass and ceramic glass fragments collected in a real recycling plant from two different production lines: coloured container glass and white container glass. To define suitable inspection strategies to separate the useful (glass) from the polluting (ceramic glass) materials at the recycling plants, fragments presenting different colour, thickness, size, shape and manufacturing were selected. Both dirty and clean cullet was considered. The analyses, carried out in the MIR spectral field (2280-4480 nm), show that ceramic glass and glass fragments can be recognized according to their different spectral signature. In particular, by selecting a specific wavelength ratio the two classes of materials can be rapidly recognized, suggesting the possibility of developing an integrated hardware and software sorting system for 'on-line' ceramic glass separation.     

Natural resources dynamics: Exhaustible and renewable resources,and the rate of technical substitution

In this paper we study both exhaustible and renewable resources in an endogenous growth model. In particular, we consider the hypotheses in which the rate of technical substitution (RTS) between those two inputs is or is not equal to one. Moreover, we depart from a basic theoretical framework to account for the negative externality constituted by waste accumulation. Finally, a comparative analysis is made between Pigouvian tax and waste recycling, as an environmental policy to correct market failure represented by refuse accumulation.     

Electromagnetic fields: principles of exposure mitigation.

Basic principles of reducing exposure to electromagnetic fields are reviewed in this article. Measures to reduce exposure can be divided into organisational/administrative and technical/engineering actions. Both strategies are briefly analysed and the basic principles of the theory of shielding are presented. A definition of shielding effectiveness (SE) is given, and the results from the general Transmission Lines Theory are presented. Practical situations of shielding static and time-varying electric and magnetic fields are discussed on the basis of the physical properties of the fields and of the shield.