Ecosystem Services economic Valuation (ESV) is often seen as a tool that can potentially enhance our collective choices regarding ecosystem services as it factors in the costs and benefits of their degradation. Yet, to achieve this, the social processes leading to decisions need to use ESV effectively. This makes it necessary to understand if and how ESV is or is not used by decision-makers.
View Article and Find Full Text PDFTwo poly(L-lactide-co-epsilon-caprolactone) random copolymers containing 5 and 40 mol % of epsilon-CL, namely P(LA-co-CL(5)) and P(LA-co-CL(40)), respectively, have been made macroporous by freeze-drying solutions in dimethylcarbonate. Most of the freeze-dried foams, prepared by varying polymer concentration and cooling rate, exhibited two main pore populations: (1). longitudinally oriented tube-like macropores with diameters >or=100 microm, and (2).
View Article and Find Full Text PDFJ Colloid Interface Sci
June 2000
Fractal analysis has been applied to characterize the structure of Pd-Ag/SiO(2) catalysts dried under vacuum (150 degrees C and 12 hPa) with different concentrations of Pd-Ag. Nitrogen adsorption-desorption, mercury porosimetry, and small-angle X-ray scattering measurements have been used. The different approaches to fractal analysis and their conditions of applicability are briefly described.
View Article and Find Full Text PDFJ Colloid Interface Sci
September 1999
The mechanism of mercury penetration in two different commercial carbon blacks is studied. We show that the volume variation measured by mercury porosimetry in these systems is due to three successive mechanisms, which occur as the pressure increases: (1) mercury invasion of voids between macroscopic grains, (2) compaction and elastic compression of macroscopic grains, (3) intrusion in the voids of aggregates formed by primary particles. The cumulative surface calculated by the Rootare-Prenzlow equation (S(RP)) in the intrusion part and the BET surface area measured by nitrogen adsorption (S(BET)) are compared.
View Article and Find Full Text PDFJ Colloid Interface Sci
June 1999
The thermodynamic method for fractal analysis is applied to mercury intrusion data. The results for representative commercial carbon black samples and a series of resorcinol-formaldehyde (RF) freeze-dried gels for different values of the molar ratio of resorcinol (R) to catalyst (C) are discussed in relation with the type of behavior exhibited by the samples during mercury porosimetry measurements. The obtained surface fractal dimensions are compared with those derived previously from the small-angle X ray scattering (SAXS) and the nitrogen adsorption.
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