5,096 research outputs found

    The Origins of the German Corporation – Finance, Ownership and Control

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    The ownership of German corporations is quite different today from that of Anglo-American firms. How did this come about? To what extent is it attributable to regulation? A specially constructed data set on financing and ownership of German corporations from the end of the 19th century reveals that, as in the UK, there was a high degree of activity on German stock markets with firms issuing equity in preference to borrowing from banks, and insider and family ownership declining rapidly. However, unlike in the UK, other companies and banks emerged as the main holders of equity, with banks holding shares primarily as custodians of other investors rather than on their own account. The changing pattern of ownership concentration was therefore very different from that of the UK with regulation reinforcing the control that banks exercised on behalf of other investors

    Thermodynamic anomalies in a lattice model of water: Solvation properties

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    We investigate a lattice-fluid model of water, defined on a 3-dimensional body-centered cubic lattice. Model molecules possess a tetrahedral symmetry, with four equivalent bonding arms. The model is similar to the one proposed by Roberts and Debenedetti [J. Chem. Phys. 105, 658 (1996)], simplified by removing distinction between "donors" and "acceptors". We focus on solvation properties, mainly as far as an ideally inert (hydrophobic) solute is concerned. As in our previous analysis, devoted to neat water [J. Chem. Phys. 121, 11856 (2004)], we make use of a generalized first order approximation on a tetrahedral cluster. We show that the model exhibits quite a coherent picture of water thermodynamics, reproducing qualitatively several anomalous properties observed both in pure water and in solutions of hydrophobic solutes. As far as supercooled liquid water is concerned, the model is consistent with the second critical point scenario.Comment: 12 pages, 9 figures, 1 tabl

    The Origins of the German Corporation – Finance, Ownership and Control

    Get PDF
    The ownership of German corporations is quite different today from that of Anglo-American firms. How did this come about? To what extent is it attributable to regulation? A specially constructed data set on financing and ownership of German corporations from the end of the 19th century reveals that, as in the UK, there was a high degree of activity on German stock markets with firms issuing equity in preference to borrowing from banks, and insider and family ownership declining rapidly. However, unlike in the UK, other companies and banks emerged as the main holders of equity, with banks holding shares primarily as custodians of other investors rather than on their own account. The changing pattern of ownership concentration was therefore very different from that of the UK with regulation reinforcing the control that banks exercised on behalf of other investors.Evolution of ownership; German stock markets; financial regulation

    A Classification of Minimal Sets of Torus Homeomorphisms

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    We provide a classification of minimal sets of homeomorphisms of the two-torus, in terms of the structure of their complement. We show that this structure is exactly one of the following types: (1) a disjoint union of topological disks, or (2) a disjoint union of essential annuli and topological disks, or (3) a disjoint union of one doubly essential component and bounded topological disks. Periodic bounded disks can only occur in type 3. This result provides a framework for more detailed investigations, and additional information on the torus homeomorphism allows to draw further conclusions. In the non-wandering case, the classification can be significantly strengthened and we obtain that a minimal set other than the whole torus is either a periodic orbit, or the orbit of a periodic circloid, or the extension of a Cantor set. Further special cases are given by torus homeomorphisms homotopic to an Anosov, in which types 1 and 2 cannot occur, and the same holds for homeomorphisms homotopic to the identity with a rotation set which has non-empty interior. If a non-wandering torus homeomorphism has a unique and totally irrational rotation vector, then any minimal set other than the whole torus has to be the extension of a Cantor set.Comment: Published in Mathematische Zeitschrift, June 2013, Volume 274, Issue 1-2, pp 405-42

    Cluster-variation approximation for a network-forming lattice-fluid model

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    We consider a 3-dimensional lattice model of a network-forming fluid, which has been recently investigated by Girardi and coworkers by means of Monte Carlo simulations [J. Chem. Phys. \textbf{126}, 064503 (2007)], with the aim of describing water anomalies. We develop an approximate semi-analytical calculation, based on a cluster-variation technique, which turns out to reproduce almost quantitatively different thermodynamic properties and phase transitions determined by the Monte Carlo method. Nevertheless, our calculation points out the existence of two different phases characterized by long-range orientational order, and of critical transitions between them and to a high-temperature orientationally-disordered phase. Also, the existence of such critical lines allows us to explain certain ``kinks'' in the isotherms and isobars determined by the Monte Carlo analysis. The picture of the phase diagram becomes much more complex and richer, though unfortunately less suitable to describe real water.Comment: 10 pages, 9 figures, submitted to J. Chem. Phy

    Revisiting waterlike network-forming lattice models

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    In a previous paper [J. Chem. Phys. 129, 024506 (2008)] we studied a 3 dimensional lattice model of a network-forming fluid, recently proposed in order to investigate water anomalies. Our semi-analytical calculation, based on a cluster-variation technique, turned out to reproduce almost quantitatively several Monte Carlo results and allowed us to clarify the structure of the phase diagram, including different kinds of orientationally ordered phases. Here, we extend the calculation to different parameter values and to other similar models, known in the literature. We observe that analogous ordered phases occur in all these models. Moreover, we show that certain "waterlike" thermodynamic anomalies, claimed by previous studies, are indeed artifacts of a homogeneity assumption made in the analytical treatment. We argue that such a difficulty is common to a whole class of lattice models for water, and suggest a possible way to overcome the problem.Comment: 13 pages, 12 figure

    The Individual and Collective Effects of Exact Exchange and Dispersion Interactions on the Ab Initio Structure of Liquid Water

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    In this work, we report the results of a series of density functional theory (DFT) based ab initio molecular dynamics (AIMD) simulations of ambient liquid water using a hierarchy of exchange-correlation (XC) functionals to investigate the individual and collective effects of exact exchange (Exx), via the PBE0 hybrid functional, non-local vdW/dispersion interactions, via a fully self-consistent density-dependent dispersion correction, and approximate nuclear quantum effects (aNQE), via a 30 K increase in the simulation temperature, on the microscopic structure of liquid water. Based on these AIMD simulations, we found that the collective inclusion of Exx, vdW, and aNQE as resulting from a large-scale AIMD simulation of (H2_2O)128_{128} at the PBE0+vdW level of theory, significantly softens the structure of ambient liquid water and yields an oxygen-oxygen structure factor, SOO(Q)S_{\rm OO}(Q), and corresponding oxygen-oxygen radial distribution function, gOO(r)g_{\rm OO}(r), that are now in quantitative agreement with the best available experimental data. This level of agreement between simulation and experiment as demonstrated herein originates from an increase in the relative population of water molecules in the interstitial region between the first and second coordination shells, a collective reorganization in the liquid phase which is facilitated by a weakening of the hydrogen bond strength by the use of the PBE0 hybrid XC functional, coupled with a relative stabilization of the resultant disordered liquid water configurations by the inclusion of non-local vdW/dispersion interactions
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