The Specific Heat and the Fermi Surface Anisotropy in Sr2RuO4

The influence of the Fermi surface anisotropy on the specific heat jump is studied for the p-wave superconductor with a gap function d = z^(k _x ± ik _y ) in connection with Sr₂RuO₄. It is shown that the normalized specific heat jump, C/T _c , is reduced from its universal value, 1.43, in accordance with experimental findings. We show that this behavior fits well into our present understanding of the quasiparticle spectrum and the impurity effects.     

Market perspectives of stationary fuel cells in a sustainable energy supply system—long-term scenarios for Germany

Because of high efficiency, low environmental impacts and a potential role in transforming our energy system into a hydrogen economy, fuel cells are often considered as a key technology for a sustainable energy supply. However, the future framing conditions under which stationary fuel cells have to prove their technical and economic competitiveness are most likely characterised by a reduced demand for space heating, and a growing contribution of renewable energy sources to heat and electricity supply, which both directly limit the potential for combined heat and power generation, and thus also for fuel cells. Taking Germany as a case study, this paper explores the market potential of stationary fuel cells under the structural changes of the energy demand and supply system required to achieve a sustainable energy supply. Results indicate that among the scenarios analysed it is in particular a strategy oriented towards ambitious CO₂-reduction targets, which due to its changes in the supply structure is in a position to mobilise a market potential that might be large enough for a successful fuel cell commercialisation. However, under the conditions of a business-as-usual trajectory the sales targets of fuel cell manufacturers cannot be met.     

Ermittlung der Aktivität des Kohlenstoffs im System Eisen–Chrom–Kohlenstoff mittels des Diffusionsverfahrens

Beschreibung des Diffusionsverfahrens als Möglichkeit zur Ermittlung von Aktivitätskoeffizienten und seiner besonderen Vorteile. Herstellung von Diffusionspaaren aus Eisen-Chrom-Kohlenstoff-Legierungen und weitgehend entkohltem Reineisen. Aufnahme von Konzentrations-Weg-Kurven und Ermittlung des Wirkungsparameters. Beeinflussung des Diffusionskoeffizienten von Kohlenstoff in Eisen durch Chrom.     

Die Wasserstofflöslichkeit von Schlacken des Systems CaO–„FeO”–SiO2

Untersuchung der Löslichkeit des Wasserstoffs in homogenen flüssigen Schlacken des Systems CaO–?FeO”–SiO₂. Einfluß der Temperatur und der Sehlackenzusammensetzung. Erörterung des Mechanismus der Wasserstofflösung in flüssigen Schlacken.