Muligheder og barrierer for brug af økologiske ingredienser i skolemadsordninger

The report considers the following aspects: 1. The arguments that two Danish municipalities mention in relation to using, or choosing not to use, organic ingredients in school meal systems. 2. The reasons for school meal companies to use, or not to use, organic ingredients in their production as well as the challenges they meet in relation to organic food. In relation to analyzing how the municipalities organize the school meal systems, we include issues such as the most common arguments used to legitimize their choice of meal system, objectives, involvement of users, most relevant decision makers etc. In the case of school meal companies, the project includes an analysis of barriers such as economy, supply of organic ingredients, structural conditions, cooperation with municipalities etc

Alas, the dark matter structures were not that trivial

The radial density profile of dark matter structures has been observed to have an almost universal behaviour in numerical simulations, however, the physical reason for this behaviour remains unclear. It has previously been shown that if the pseudo phase-space density, rho/sigma_d^epsilon, is a beautifully simple power-law in radius, with the "golden values" epsilon=3 and d=r (i.e., the phase-space density is only dependent on the radial component of the velocity dispersion), then one can analytically derive the radial variation of the mass profile, dispersion profile etc. That would imply, if correct, that we just have to explain why rho/sigma^3_r ~r^{-alpha}, and then we would understand everything about equilibrated DM structures. Here we use a set of simulated galaxies and clusters of galaxies to demonstrate that there are no such golden values, but that each structure instead has its own set of values. Considering the same structure at different redshifts shows no evolution of the phase-space parameters towards fixed points. There is also no clear connection between the halo virialized mass and these parameters. This implies that we still do not understand the origin of the profiles of dark matter structures.Comment: 4 pages, 3 figures, accepted for publication in ApJ

First-order layering and critical wetting transitions in non-additive hard sphere mixtures

Using fundamental-measure density functional theory we investigate entropic wetting in an asymmetric binary mixture of hard spheres with positive non-additivity. We consider a general planar hard wall, where preferential adsorption is induced by a difference in closest approach of the different species and the wall. Close to bulk fluid-fluid coexistence the phase rich in the minority component adsorbs either through a series of first-order layering transitions, where an increasing number of liquid layers adsorbs sequentially, or via a critical wetting transition, where a thick film grows continuously.Comment: 4 pages, 4 figure

Organic and conventional public food procurement for youth in Denmark

This report is the first mapping of the activities and state-of-the-art on public organic food procurement for youth. The report, on the Danish activities, comes together with similar reports from Finland, Italy and Norway. These four reports will inform a comparative analysis conducted by DTU in workpackage 2 of the iPOPY project. The major focus of the reports is school meals and the use of and potentials for organic products in this setting. But also other important settings than schools are included. The perspectives of the reports are on the policies and the policy processes influencing the extension of organic school meals. The report is produced within the project “innovative Public Organic food Procurement for Youth”, iPOPY, and will be updated and revised during the project period (2007-2010)

Electro-Hydraulic Variable-Speed Drive Networks—Idea, Perspectives, and Energy Saving Potentials

Electro-hydraulic differential cylinder drives with variable-speed displacement units as their central transmission element are subject to an increasing focus in both industry and academia. A main reason is the potential for substantial efficiency increases due to avoidance of throttling of the main flows. Research contributions have mainly been focusing on appropriate compensation of volume asymmetry and the development of standalone self-contained and compact solutions, with all necessary functions onboard. However, as many hydraulic actuator systems encompass multiple cylinders, such approaches may not be the most feasible ones with respect to efficiency or commercial feasibility. This article presents the idea of multi-cylinder drives, characterized by electrically and hydraulically interconnected variable-speed displacement units essentially allowing for completely avoiding throttle elements, while allowing for hydraulic and electric power sharing as well as the sharing of auxiliary functions and fluid reservoir. With drive topologies taking offset in communication theory, the concept of electro-hydraulic variable-speed drive networks is introduced. Three different drive networks are designed for an example application, including component sizing and controls in order to demonstrate their potentials. It is found that such drive networks may provide simple physical designs with few building blocks and increased energy efficiencies compared to standalone drives, while exhibiting excellent dynamic properties and control performance