2 resultados para HOMOGENEOUS STRUCTURE
em Aston University Research Archive
Resumo:
Using a data set for the 162 largest Hungarian firms during the period of 1994-1999, this paper explores the determinants of equity shares held by both foreign investors and Hungarian corporations. Evidence is found for a post-privatisation evolution towards more homogeneous equity structures, where dominant categories of Hungarian and foreign owners aim at achieving controlling stakes. In addition, focusing on firm-level characteristics we find that exporting firms attract foreign owners who acquire controlling equity stakes. Similarly, firm-size measurements are positively associated with the presence of foreign investors. However, they are negatively associated with 100% foreign ownership, possibly because the marginal costs of acquiring additional equity are growing with the size of the assets. The results are interpreted within the framework of the existing theory. In particular, following Demsetz and Lehn (1985) and Demsetz and Villalonga (2001) we argue that equity should not be treated as an exogenous variable. As for specific determinants of equity levels, we focus on informational asymmetries and (unobserved) ownership-specific characteristics of foreign investors and Hungarian investors.
Resumo:
We have investigated the microstructure and bonding of two biomass-based porous carbon chromatographic stationary phase materials (alginic acid-derived Starbon® and calcium alginate-derived mesoporous carbon spheres (AMCS) and a commercial porous graphitic carbon (PGC), using high resolution transmission electron microscopy, electron energy loss spectroscopy (EELS), N2 porosimetry and X-ray photoelectron spectroscopy (XPS). The planar carbon sp -content of all three material types is similar to that of traditional nongraphitizing carbon although, both biomass-based carbon types contain a greater percentage of fullerene character (i.e. curved graphene sheets) than a non-graphitizing carbon pyrolyzed at the same temperature. This is thought to arise during the pyrolytic breakdown of hexauronic acid residues into C5 intermediates. Energy dispersive X-ray and XPS analysis reveals a homogeneous distribution of calcium in the AMCS and a calcium catalysis mechanism is discussed. That both Starbon® and AMCS, with high-fullerene character, show chromatographic properties similar to those of a commercial PGC material with extended graphitic stacks, suggests that, for separations at the molecular level, curved fullerene- like and planar graphitic sheets are equivalent in PGC chromatography. In addition, variation in the number of graphitic layers suggests that stack depth has minimal effect on the retention mechanism in PGC chromatography. © 2013 Elsevier Ltd. All rights reserved.