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a b s t r a c tThe transition to a circular economy, where the value of resources is preserved in the technosphere, must be supported by policies and operational decision-making based on evidence. Existing methods used to provide this evidence (e.g. LCA, LCSA, CBA) are not robust enough to adequately address the creation and dissipation of systemic and multidimensional value that spans the social, environmental, economic and technical domains. This study proposes a novel, conceptual approach that seeks to assess how complex value is created, destroyed and distributed in resource recovery from waste systems. This approach expands beyond conventional methods of estimating value. It combines scientific and engineering methods with a socio-political narrative grounded in the systems of provision (sop) approach, and provides a comprehensive, analytical framework for making the transition to a resource-efficient future. This framework has the potential to connect bottom-up and top-down approaches in assessing resource recovery from waste systems, and address systemic challenges through transparency and flexibility, while accounting for the dynamic and non-linear nature of commodities flow and infrastructure provision in the overall system. This creates the pathway towards circular economy, and lays the foundations for future advances in computational and assessment methodologies in the field of RRfW. Crown

There are many geometrical factors than can influence the aerodynamic parameters of urban surfaces and hence the vertical wind profiles found above. The knowledge of these parameters has applications in numerous fields, such as dispersion modelling, wind loading calculations, and estimating the wind energy resource at urban locations. Using quasiempirical modelling, we estimate the dependence of the aerodynamic roughness length and zero-plane displacement for idealized urban surfaces, on the two most significant geometrical characteristics; surface area density and building height variability. A validation of the spatially-averaged, logarithmic wind profiles predicted by the model is carried out, via comparisons with available wind-tunnel and numerical data for arrays of square based blocks of uniform and heterogeneous heights. The model predicts two important properties of the aerodynamic parameters of surfaces of heterogeneous heights that have been suggested by experiments. Firstly, the zero-plane displacement of a heterogeneous array can exceed the surface mean building height significantly. Secondly, the characteristic peak in roughness length with respect to surface area density becomes much softer for heterogeneous arrays compared to uniform arrays, since a variation in building height can prevent a skimming flow regime from occurring. Overall the simple model performs well against available experimental data and may offer more accurate estimates of surface aerodynamic parameters for complex urban surfaces compared to models that do not include height variability.

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