Analysing the potential for further urban densification: a case study for the Netherlands

Urban areas in the Netherlands are rapidly transforming. Many new houses have been built to replace e.g. vacant industrial buildings or fill under-used sites, but it is unclear whether such transformations can accommodate the projected growth in housing stock. This study analyses the spatial and economic feasibility of further intensification. It focusses on quantifying the costs and benefits of two types of densification: changing the main function of current urban areas (e.g. from industrial to residential), or densifying these areas (i.e. adding extra housing units to existing residential areas). In order to quantify the different components of these transformation costs, a literature study and interviews with sector experts were conducted. These main factors influencing the local costs and benefits for densification include: actual land-use, building-type, building age, soil contamination, accessibility, and others. In cooperation with the municipality of The Hague, a case study was set up to analyse a selection of potential transformation sites in the city. This case study aided in revealing the different costs and benefits of transformation projects. Using the insights gained in the literature review and case study analysis and applying a spatially-explicit modelling approach (Land Use Scanner), we simulated potential transformation under different socio-economic scenarios. In this approach the potential for transformation was calculated based on current land-use, zoning regulations, building characteristics, transformation costs and other location-specific characteristics related to for example local accessibility. These suitability scores were used in combination with the regional projected housing demand to find the most likely areas for urban densification/transformation. Furthermore, this tool is used to evaluate the implications of relevant alternative policy measures

Harmonic Sums and Mellin Transforms up to two-loop Order

A systematic study is performed on the finite harmonic sums up to level four. These sums form the general basis for the Mellin transforms of all individual functions $f_i(x)$ of the momentum fraction $x$ emerging in the quantities of massless QED and QCD up to two--loop order, as the unpolarized and polarized splitting functions, coefficient functions, and hard scattering cross sections for space and time-like momentum transfer. The finite harmonic sums are calculated explicitly in the linear representation. Algebraic relations connecting these sums are derived to obtain representations based on a reduced set of basic functions. The Mellin transforms of all the corresponding Nielsen functions are calculated.Comment: 44 pages Latex, contract number adde

Constraints on the momentum dependence of rho-omega mixing

Within a broad class of models we show that the amplitude for rho^0-omega mixing must vanish at the transition from timelike to spacelike four momentum. Hence in such models the mixing is either zero everywhere or is necessarily momentum-dependent. This lends support to the conclusions of other studies of rho-omega mixing and calls into question standard assumptions about the role of rho-omega mixing in the theoretical understanding of charge-symmetry breaking in nuclear systems.Comment: 8 pages. Publication details added to title pag

One-loop corrections to omega photoproduction near threshold

One-loop corrections to $\omega$ photoproduction near threshold have been investigated by using the approximation that all relevant transition amplitudes are calculated from the tree diagrams of effective Lagrangians. With the parameters constrained by the data of $\gamma N \to \pi N$, $\gamma N \to \rho N$, and $\pi N \to \omega N$ reactions, it is found that the one-loop effects due to the intermediate $\pi N$ and $\rho N$ states can significantly change the differential cross sections and spin observables. The results from this exploratory investigation suggest strongly that the coupled-channel effects should be taken into account in extracting reliable resonance parameters from the data of vector meson photoproduction in the resonance region.Comment: 19 pages, REVTeX, 14 figures, title changed, revised version to appear in Phys. Rev.

Actualisering landgebruiksimulatie Deltascenario’s: Achtergronddocument bij Ruimtescanner inzet. Spinlab Research Memorandum SL-12

De Deltascenario’s beschrijven mogelijke toekomstige ontwikkelingen die van belang zijn voor wateropgaven in Nederland. In opdracht van het Ministerie van Infrastructuur en Milieu werkt Deltares aan het actualiseren van de oorspronkelijke Deltascenario’s die in 2012-2013 door diverse onderzoeksinstellingen zijn opgesteld. Voor de ruimtelijke vertaling van de geactualiseerde scenario’s heeft Deltares beroep gedaan op de VU. Met behulp van het model Ruimtescanner heeft de VU in nauwe samenwerking met PBL Planbureau voor de Leefomgeving gewerkt aan: - het vervaardigen van landgebruikskaarten voor de huidige situatie (2012) en voor de vier deltascenario’s; - het vervaardigen van een landgebruikskaart voor de scenariovariant 'Parijs'; - het vervaardigen van verhardingskaarten in het stedelijke gebied van ieder van de hierboven genoemde landgebruikskaarten