Die Anwendung des elektrischen Stroms zur Reinigung von Säften und Sirupen in der Zuckerindustrie

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Prediction of Electrolyte Solubilities from Minimal Thermodynamic Information

 A method is proposed that permits the proper extrapolation of thermodynamic quantities represented by the Pitzer equations from 25°C to other temperatures. The new method, which assumes temperature independent heat capacities, was tested for the NaCl*H₂O system and found very satisfactory. A new evaluation of the Na₂CO₃*H₂O system according to the CALPHAD method is presented, and solubilities for the quaternary Na₂CO₃*NaCl*NaOH*H₂O and its ternary subsystems are predicted. Limitations of (i) these predictions and of (ii) the Pitzer model regarding extrapolations to high molalities are discussed.     

Prediction of Electrolyte Solubilities from Minimal Thermodynamic Information

Summary.  A method is proposed that permits the proper extrapolation of thermodynamic quantities represented by the Pitzer equations from 25°C to other temperatures. The new method, which assumes temperature independent heat capacities, was tested for the NaCl*H₂O system and found very satisfactory. A new evaluation of the Na₂CO₃*H₂O system according to the CALPHAD method is presented, and solubilities for the quaternary Na₂CO₃*NaCl*NaOH*H₂O and its ternary subsystems are predicted. Limitations of (i) these predictions and of (ii) the Pitzer model regarding extrapolations to high molalities are discussed. Received April 20, 2001. Accepted May 2, 2001     

Über Kapillarsysteme XXII

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Electronic structure calculations and strong correlations: A model study

Metals with strong correlations are a major challenge for realistic electronic structure calculations. The complexity of the systems under consideration precludes a direct fully microscopic treatment by means of the theoretical and computational methods available at present. The present paper analyzes the applicability and restrictions of common approximation schemes by comparing their predictions for a model pertinent to heavy fermion metals to the exact solution. The criteria chosen for the assessment are the density distribution in the ground state as well as the energy scale for low-lying excitations.     

Core,value and equilibria for market games: On a problem of Aumann and Shapley

In this note a partial solution of Open Problem 41C of Aumann and Shapley [1974, pp. 250–251] is presented. A sufficient condition for the Aumann-Shapley value of a market game to exist, to be contained in its core, and to be the competitive payoff distribution of a transferable utility competitive equilibrium is given. In this context, balancedness and σ-balancedness criteria for large classes of cooperative games are proven.     

Wetting barriers

Wetting barriers are edges or lines of a solid surface where different materials meet each other. Typical questions are how much of a fluid rests in a capillary tube or how much can piled up on a glass. We will derive a necessary condition which must be satisfied if a capillary surface hangs on a wetting barrier and if it defines a weak local minimum of the associated energy functional. In general, this functional is not smooth and the set of admissible variations is not a linear space. Then, we derive an eigenvalue criterion which provides a sufficient condition for a given capillary surface to be a weak local minimizer of the associated energy functional. Received: 18 December 2000 / Accepted: 7 June 2001 / Published online: 19 October 2001