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In the Roman wall paintings different white colours were used, named Paraetonium, Melinum, Anularia, Eretria, Argentaria, etc. FTIR, Raman spectroscopy and X-Ray diffraction were applied to study different white pigments, such as calcite, aragonite, dolomite and huntite, white carbonates present in archaeological findings from roman walls in the Mediterranean region. This study showed that it is possible to distinguish and identify these components in white colours. About 450 samples of Roman wall paintings were analysed and it was observed that often aragonite is associated to precious coloured pigments. On the basis of the obtained results some considerations about the period in which the different kinds of white pigments were used are proposed. [ABSTRACT FROM AUTHOR]

In the Roman wall paintings different white colours were used, named Paraetonium, Melinum, Anularia, Eretria, Argentaria, etc. FTIR, Raman spectroscopy and X-Ray diffraction were applied to study different white pigments, such as calcite, aragonite, dolomite and huntite, white carbonates present in archaeological findings from Roman walls in the Mediterranean region. This study showed that it is possible to distinguish and identify these components in white colours. About 450 samples of Roman wall paintings were analysed and it was observed that often aragonite is associated to precious coloured pigments. On the basis of the obtained results some considerations about the period in which the different kinds of white pigments were used are proposed.

Three clayey raw materials for production of traditional ceramics, all with medium to high fluorine content, have been investigated for determining their attitude to fluoride emission during firing, at varying parameters of the firing cycle, maximum firing temperature included, and in the presence or in the absence of calcium carbonate either added to the sample or naturally present in it. Different analytical methods for the determination of fluoride have been tested, together with different sample preparation procedures aimed to obtain minimum loss of fluoride in the pre-treatment step.

Measurements of the refractive index n for the binary mixtures 2-chloroethanol + 2-methoxyethanol in the 0 < or = t/degree C < or = 70 temperature range have been carried out with the purpose of checking the capability of empirical models to express physical quantity as a function of temperature and volume fraction, both separately and together, i.e., in a two independent variables expression. Furthermore, the experimental data have been used to calculate excess properties such as the excess refractive index, the excess molar refraction, and the excess Kirkwood parameter delta g over the whole composition range. The quantities obtained have been discussed and interpreted in terms of the type and nature of the specific intermolecular interactions between the components.

A study on polythiophene coated microelectrodes is reported, the goal being that of checking the capability of these electrochemical systems to work in low conductive media. The possibility of electrochemically p-doping the polymer in the presence of very low concentrations or even in the absence of supporting electrolyte in the solution is ascertained, opening the way to the use of similar systems in pure solvent media. This result is obtained in such conditions that the presence of residual charges--and corresponding counterions--trapped inside the film coating can be reasonably hypothesised.