Erwinia berokkent pootgoedsector vele miljoenen schade

De besmetting met Erwinia ontwikkelt zich de laatste jaren tot een serieus probleem in de pootgoedsector. Voor telers ontstaat inkomensderving door lagere opbrengstprijzen en onbruikbare pootgoedvoorraden. Handelshuizen lijden schade door margedaling en reclameringen. Een aantasting van het imago van Nederlands pootgoed kan in de toekomst tot extra schade leiden

Virtual integration platform for computational fluid dynamics

Computational Fluid Dynamics (CFD) tools used in shipbuilding industry involve multiple disciplines, such as resistance, manoeuvring, and cavitation. Traditionally, the analysis was performed separately and sequentially in each discipline, which often resulted in conflict and inconsistency of hydrodynamic prediction. In an effort to solve such problems for future CFD computations, a Virtual Integration Platform (VIP) has been developed in the University of Strathclyde within two EU FP6 projects - VIRTUE and SAFEDOR1. The VIP provides a holistic collaborative environment for designers with features such as Project/Process Management, Distributed Tools Integration, Global Optimisation, Version Management, and Knowledge Management. These features enhance collaboration among customers, ship design companies, shipyards, and consultancies not least because they bring together the best expertise and resources around the world. The platform has been tested in seven European ship design companies including consultancies. Its main functionalities along with advances are presented in this paper with two industrial applications

Spin-dependent transport in metal/semiconductor tunnel junctions

This paper describes a model as well as experiments on spin-polarized tunnelling with the aid of optical spin orientation. This involves tunnel junctions between a magnetic material and gallium arsenide (GaAs), where the latter is optically excited with circularly polarized light in order to generate spin-polarized carriers. A transport model is presented that takes account of carrier capture in the semiconductor surface states, and describes the semiconductor surface in terms of a spin-dependent energy distribution function. The so-called surface spin-splitting can be calculated from the balance of the polarized electron and hole flow in the semiconductor subsurface region, the polarized tunnelling current across the tunnel barrier between the magnetic material and the semiconductor surface, and the spin relaxation at the semiconductor surface. Measurements are presented of the circular-polarization-dependent photocurrent (the so-called helicity asymmetry) in thin-film tunnel junctions of Co/Al2O3/GaAs. In the absence of a tunnel barrier, the helicity asymmetry is caused by magneto-optical effects (magnetic circular dichroism). In the case where a tunnel barrier is present, the data cannot be explained by magneto-optical effects alone; the deviations provide evidence that spin-polarized tunnelling due to optical spin orientation occurs. In Co/τ-MnAl/AlAs/GaAs junctions no deviations from the magneto-optical effects are observed, most probably due to the weak spin polarization of τ-MnAl along the tunnelling direction; the latter is corroborated by bandstructure calculations. Finally, the application of photoexcited GaAs for spin-polarized tunnelling in a scanning tunnelling microscope is discussed.

Natuur & biodiversiteit in de biologische markt: Verkenning van de mogelijkheden om natuur en biodiversiteit in de biologische markt te verwaarden

Het project 'Marktontwikkeling Natuur en biodiversiteit' heeft geresulteerd in twee pakketten aan maatregelen die aansluiten bij consumentenbeleving, haalbaar zijn voor boeren en bijdragen aan natuur en biodiversiteit. Het ene pakket is ontwikkeld voor en met biologische boeren en het andere voor en met biologisch-dynamische boeren. De aangrijpingspunten zijn dezelfde, alleen de zwaarte verschilt. De pakketten hebben draagvlak bij boeren, verwerkers en ngo’s en worden verder ontwikkeld en geïmplementeerd. Samen met boeren, verwerkers en ngo’s zijn twee pakketten aan maatregelen ontwikkeld om natuur en biodiversiteit op de biologische en biodynamische bedrijven een impuls te geven. Doel van het project was een verkenning van de mogelijkheden om natuur en biodiversiteit te vermarkten

Instrumentarium monitoring mestmarkt en enkele analyses

Het nieuwe mestbeleid met daarin een stelsel van gebruiksnormen en de bijbehorende normen grijpen naar verwachting fors in op de mestmarkt. Dit rapport beschrijft onderdelen van het instrumentarium voor de monitoring van de mestmarkt. De onderdelen zijn analyses van derogatiebedrijven (1), van de acceptatie van dierlijke mest op kleiakkerbouwbedrijven (2) en van het gedrag van melkveehouders op het nieuwe mestbeleid (3). Daarnaast beschrijft het rapport de opzet voor een systeem voor monitoring van mestprijzen (4) en de opzet voor interviews met mestdistributeurs (5)

Proximity to Sports Facilities and Sports Participation for Adolescents in Germany

Objectives - To assess the relationship between proximity to specific sports facilities and participation in the corresponding sports activities for adolescents in Germany. Methods - A sample of 1,768 adolescents aged 11–17 years old and living in 161 German communities was examined. Distances to the nearest sports facilities were calculated as an indicator of proximity to sports facilities using Geographic Information Systems (GIS). Participation in specific leisure-time sports activities in sports clubs was assessed using a self-report questionnaire and individual-level socio-demographic variables were derived from a parent questionnaire. Community-level socio-demographics as covariates were selected from the INKAR database, in particular from indicators and maps on land development. Logistic regression analyses were conducted to examine associations between proximity to the nearest sports facilities and participation in the corresponding sports activities. Results - The logisitic regression analyses showed that girls residing longer distances from the nearest gym were less likely to engage in indoor sports activities; a significant interaction between distances to gyms and level of urbanization was identified. Decomposition of the interaction term showed that for adolescent girls living in rural areas participation in indoor sports activities was positively associated with gym proximity. Proximity to tennis courts and indoor pools was not associated with participation in tennis or water sports, respectively. Conclusions - Improved proximity to gyms is likely to be more important for female adolescents living in rural areas