National and international freight transport models: overview and ideas for further development

This paper contains a review of the literature on freight transport models, focussing on the types of models that have been developed since the nineties for forecasting, policy simulation and project evaluation at the national and international level. Models for production, attraction, distribution, modal split and assignment are discussed in the paper. Furthermore, the paper also includes a number of ideas for future development, especially for the regional and urban components within national freight transport models

The asymptotic regimes of tilted Bianchi II cosmologies

In this paper we give, for the first time, a complete description of the dynamics of tilted spatially homogeneous cosmologies of Bianchi type II. The source is assumed to be a perfect fluid with equation of state $p = (\gamma -1) \mu$, where $\gamma$ is a constant. We show that unless the perfect fluid is stiff, the tilt destabilizes the Kasner solutions, leading to a Mixmaster-like initial singularity, with the tilt being dynamically significant. At late times the tilt becomes dynamically negligible unless the equation of state parameter satisfies $\gamma > {10/7}$. We also find that the tilt does not destabilize the flat FL model, with the result that the presence of tilt increases the likelihood of intermediate isotropization

Determinants of poverty in Kenya : a household level analysis

poverty;statistical analysis;measurement;Kenya;household surveys

On the Relation between Subglacial Tills and the Substratum in Western Allgäu (Germany)

Korngrößen-, Kies- und Schwermineralanalysen würmzeitlicher Grundmoränen-Ablagerungen des Rheingletschers im baden-württembergischen Alpenvorland zeigen einen meist relativ niedrigen Einfluß des aus Molasse bestehenden Substrats auf die Zusammensetzung dieser Sedimente. Auf Grund theoretischer Überlegungen und großmorphologischer Beobachtungen wird geschlossen, daß auch die Aufnahme präexistierender quartärer Ablagerungen untergeordnet war und daß die Petrographie der Moränen-Ablagerungen hauptsächlich bestimmt wird vom während der letzten Vorland-Vergletscherung vom Rheingletscher ins Vorland transportierten Schutt.researc

Dynamics of the molecular orientation field coupled to ions in two-dimensional ferroelectric liquid crystals

Molecular orientation fluctuations in ferroelectric smectic liquid crystals produce space charges, due to the divergence of the spontaneous polarization. These space charges interact with mobile ions, so that one must consider the coupled dynamics of the orientation and ionic degrees of freedom. Previous theory and light scattering experiments on thin free-standing films of ferroelectric liquid crystals have not included this coupling, possibly invalidating their quantitative conclusions. We consider the most important case of very slow ionic dynamics, compared to rapid orientational fluctuations, and focus on the use of a short electric field pulse to quench orientational fluctuations. We find that the resulting change in scattered light intensity must include a term due to the quasistatic ionic configuration, which has previously been ignored. In addition to developing the general theory, we present a simple model to demonstrate the role of this added term