0000000000890115
AUTHOR
C. Belfiore
Study of the effects of salt crystallisation on degradation of limestone rocks
Salt crystallization is widely recognized as a cause of deterioration of porous building materials. In particular, the crystallization pressure of salt crystals growing in confined pores is found to be the main cause for damage. The aim of this study is to better understand the degradation of porous rocks induced by salt crystallisation and correlate such processes with the intrinsic characteristics of materials. With this intend, an experimental salt weathering simulation has been carried out on two limestones widely used in the Baroque architecture of eastern Sicily. A systematic approach including petrographic, porosimetric and colorimetric analyses, was used to evaluate the correlation …
Electrically conductive hydrogel composites made of polyaniline nanoparticles and poly(N-vinyl-2-pyrrolidone)
Abstract A novel electrically conductive composite material, consisting of polyaniline (PANI) nanoparticles dispersed in a polyvinyl pyrrolidone (PVP) hydrogel, was prepared ‘in situ’ by water dispersion polymerisation (DP) of aniline using PVP as steric stabiliser, followed by γ-irradiation induced crosslinking of the PVP component. Conversion yield of aniline into PANI particles was determined via HPLC and gas chromatography, while structural confirmation of the synthesised polymer was sought by FTIR. Morphology and dimensions of PANI particles into the coloured, optically transparent hydrogel was determined by electronic microscopy; moreover, swelling behaviour of composite hydrogels in …
Taxonomy and phenetic relationships ofElectrogena affinis(Eaton, 1883) (Ephemeroptera : Heptageniidae)
Electrogena affinis est redecrite a tous les stades du cycle de developpement. Les larves ont ete etudiees et comparees aux autres especes europeennes du meme genre sur des caracteres de diagnose standard qui, dans des precedents travaux, se sont montres tres utiles pour la taxonomie d'Electrogena. Le statut d'E. fascioculata est discute et la synonymie E. fascioculata = E. affinis est etablie. Finalement, les liaisons phenetiques entre E. affinis et d'autres especes europeennes voisines sont examinees par une analyse de groupes sur la base de caracteres quantitatifs des larves.