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  • Author or Editor: G. Della Gatta x
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A miniaturized effusion cell adapted to a Sorption LKB microcalorimeter has been designed, built and tested. Vaporization is performed isothermally into a vacuum through a small orifice permitting a vapour pressure very close to the equilibrium values. The cell has been tested by measuring the enthalpies of vaporization at 298.15 K of reference liquid compounds (water, benzene, propanol-1, propanol-2) with a reproducibility better than 1%. Enthalpies of vaporization of butanol-1 and deuterated water have also been determined.

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Enthalpies and entropies of sublimation for N-acetylglycine amide (NAGA), N-acetyl-L-alanine amide (L-NAAA), and N-acetyl-D-leucine amide (D-NALA) were determined from the dependence of their vapour pressures on temperature, as measured by the torsion-effusion method.

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Journal of Thermal Analysis and Calorimetry
Authors: G. Della Gatta, E. Badea, R. Ceccarelli, T. Usacheva, A. Maši?, and S. Coluccia

Summary  

Environmental impact on parchment was investigated by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Parchments subjected to accelerated ageing and old parchments were compared to evaluate quality and extent of deterioration. Stability of fibrillar collagen within parchment was determined from the changes in thermodynamic parameters associated with thermal denaturation. Parchment surface was characterised, and specific morphological criteria were selected for damage assessment. The thermodynamic and morphological changes of collagen induced by deterioration are discussed, and their correlations are proposed as a means of ranking damage in old parchments.</o:p>

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Abstract  

Molar heat capacities of twelve linear alkane-α,ω-diamides H2NOC-(CH2)(n-2)-CONH2, (n=2 to 12 and n=14) were measured by differential scanning calorimetry at T=183 to 323 K. Heat flow rate calibration of the Mettler DSC 30 calorimeter was carried out by using benzoic acid as reference material. The calibration was checked by determining the molar heat capacity of urea in the same temperature range as that of measurements. The molar heat capacities of alkane-α,ω-diamides increased in function of temperature and fitted into linear equations. Smoothed values of C p,m at 298.15 K displayed a linear increase with the number of carbon atoms. The C p,m contribution of CH2 group was (22.6±0.4) J K−1 mol−1, in agreement with our previous results concerning linear alkane-a,ω-diols and primary alkylamides as well as the literature data on various series of linear alkyl compounds.

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Abstract  

A comprehensive investigation has been made of a set of 14th to 16th-century parchment bookbindings from the Historical Archives of the City of Turin. Advanced physico-chemical techniques, such as thermal analysis (DSC, TG and DTA), spectroscopy (FTIR and UV-Vis-NIR), scanning electron microscopy (SEM) and unilateral nuclear magnetic resonance (NMR-ProFiler) were employed to assess specific deterioration processes occurring at different levels in the hierarchical structure of parchment. Changes in the measured physical and chemical parameter values of parchment due to interaction with the environment were used to identify possible deterioration pathways.

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