Liquid xenon as an ideal probe for many-body effects in impulsive Raman scattering

The collision induced effects in the third-order Raman response of liquid xenon have been studied both experimentally and theoretically. The effect of electron cloud overlap on the polarizability of xenon dimers was studied using accurate time-dependent density functional theory calculations. The dimer polarizabilities were used to fit parameters in a direct reaction field model that can be generalized to condensed phase systems. This model was employed in molecular dynamics simulations in order to calculate the impulsive Raman response of liquid xenon. Excellent agreement is found between the shape of the calculated and the measured anisotropic part of the response. The shape of this response is little affected by the electron overlap effects, but the intensity is strongly influenced by it. The shape of the isotropic response is predicted to be strongly dependent on electron overlap effects

Theorizing practice and practising theory: outlines for an actor-relational approach in planning

Not only in the Netherlands, but also elsewhere, there is stalemate between modern and postmodern/post-structural planning, or alternatively, between state-controlled and neo-liberal planning. Since the 1980s at least, modernist, state-controlled planning has been fundamentally debunked as a highly regulatory and prescriptive operation, resulting in syrupy planning processes, which are very costly, inflexible and inefficient, and suppressing all new and creative initiatives that do not fit within the set framework. Postmodern and post-structural alternatives developed since then have been very effective in counter-attacking the alleged virtues of that planning strategy, but less fruitful at promoting effective and/or sustainable practices. The article assumes that this is related to the fact that time and again these alternatives continue to be formulated from within the existing planning framework, from a specific governmental, or at least a government influenced, view of planning: in essence from the inside-out. From this position, the article goes on to describe the possible outlines for a practical outside-inward, actorrelational- approach. It has been developed from experimental case studies in concrete planning practices, for example, a case study in Southern Limburg in the Netherlands. Concurrently, it has also been derived from a fundamental interaction with behavioural, urban regime and actor-network/network actor theories, with an extensive evaluation of the latter. The article concludes with a call for a new fundamental, but proactive, reassembling of spatial planning in an actor-oriented, as opposed to a government-oriented, way