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Application of Thermoporometry Based on Convolutive DSC to Investigation of Mesoporosity in Cohesive Soils

Kozłowski T., Babiarz I., Grobelska E.

Archives of Hydro-Engineering and Environmental Mechanics

2010

Vol. 57, nr 3-4

199-218

In the method of thermoporometry, the characterization of pore space is done by analysis of thermal effects associated with freezing and melting of a liquid in the pores of the material under investigation. Thermoporometry seems particularly well suited to studies of wet porous samples in cases where the process of drying itself is able to destroy the original microstructure, as is the cohesive soils containing montmorillonite. In the paper, a variant of thermoporometry is given in which the blurred calorimetric peak is processed by use of a stochastic-convolutive analysis. As a result, a "sharp" thermogram of real thermal effects is obtained which can be easily transformed into a pore distribution curve. The preliminary results, obtained for samples of three monoionic montmorillonites at different water contents, indicate a greater resolution, sensitivity and precision than the classical thermoporometry using an unprocessed DSC signal. Phenomena corresponding to swelling have been detected in two individual regions on the differential pore distribution curves. The first is a dense spectrum for pores less than 15 nm. The second is a single peak for pores greater than 15 nm. Between the two regions the distribution decays to zero. Apparently, the point of the single peak maximum depends on the total water content, shifting rightward with increasing w. For the region below 20 nm, a strong effect of the kind of exchangeable cation can be observed. The results suggest swelling in the form with bivalent cations (Ca-montmorillonite) and contraction in the form with monovalent cations (Na- and K-montmorillonite).

Wpływ sadzy fulerenowej na odporność oksydacyjną roślinnych kompozycji olejowych

Drabik J., Pawelec E., Huczko A.

Tribologia

2005

nr 4

45-53

W artykule przedstawiono stabilność oksydacyjną kompozycji olejowych, zawierających dodatek czystych fulerenów C60 oraz sadzy fulerenowej o zróżnicowanej zawartości cząstek C60. Oceniono skuteczność działania zastosowanych fulerenów C60 w stosunku do oleju bazowego. Metodę różnicowej kalorymetrii skaningowej zastosowano do wyznaczenia odporności na proces utleniania oleju roślinnego. Na podstawie uzyskanych wyników wyznaczono odporność kompozycji olejowych przygotowanych na bazie surowego oleju rzepakowego na proces termooksydacji.

The fullerene soot containing different concentrations of C60 has been tested as an active additive influencing the lubricating properties of a vegetable oil used as a reference lubricant. The quality assessment of the vegetable oil - compositions has been made using DSC (Differential Scanning Calorimetry). The thermal oxidation stability of both vegetable oils containing the fullerene soot will be assessed, focusing on efficiency of the action of fullerenes.