Dynamic mesh refinement for discrete models of jet electro-hydrodynamics

Nowadays, several models of unidimensional fluid jets exploit discrete element methods. In some cases, as for models aiming at describing the electrospinning nanofabrication process of polymer fibers, discrete element methods suffer a non constant resolution of the jet representation. We develop a dynamic mesh-refinement method for the numerical study of the electro-hydrodynamic behavior of charged jets using discrete element methods. To this purpose, we import ideas and techniques from the string method originally developed in the framework of free-energy landscape simulations. The mesh-refined discrete element method is demonstrated for the case of electrospinning applications.Comment: 16 pages, 7 figures in Journal of Computational Science, 201

Resilience Through Community Landscape Project

The evolutionary process for landscape conservation, planning and management should consider the local (bottom –up) contribution connected to the emerging and rapidly growing models related to social self-organisation and local and community activism in the management of public goods (co-management models). But key issues for landscape resilience are: developing decisional models and integration between self community and planned actions.The case studies considers instead issues for developing a resilient landscape system: management of green areas, ways of enhancing green infrastructure linking rural and urban context, urban agriculture, innovative and inclusive management, urban landscape design, biodiversity and food security, identity valorisation, public and private initiatives linked in coherent strategie

Directed Polymer -- Directed Percolation Transition

We study the relation between the directed polymer and the directed percolation models, for the case of a disordered energy landscape where the energies are taken from bimodal distribution. We find that at the critical concentration of the directed percolation, the directed polymer undergoes a transition from the directed polymer universality class to the directed percolation universality class. We also find that directed percolation clusters affect the characterisrics of the directed polymer below the critical concentration.Comment: LaTeX 2e; 12 pages, 5 figures; in press, will be published in Europhys. Let

Sensitivity of night cooling performance to room/system design: surrogate models based on CFD

Night cooling, especially in offices, attracts growing interest. Unfortunately, building designers face considerable problems with the case-specific convective heat transfer by night. The BES programs they use actually need extra input, from either costly experiments or CFD simulations. Alternatively, up-front research on how to engineer best a generic night cooled office – as in this work – can thrust the application of night cooling. A fully automated configuration of data sampling, geometry/grid generation, CFD solving and surrogate modelling, generates several surrogate models. These models relate the convective heat flow in a night cooled landscape office to the ventilation concept, mass distribution, geometry and driving force for convective heat transfer. The results indicate that cases with a thermally massive floor have the highest night cooling performance

Dynamic models to reconstruct ancient landscapes

In this paper a method of landscape analysis is demonstrated through raster-based digital elevation models (DEM) using the case-study of the Helike Delta, Gulf of Corinth, Greece. In the Classical Period, Helike was the seat of the Achaean League and the worship centre of the god Helikonian Poseidon. With the focus on the earthquake and tsunami of 373BC, DEMs are generated using dynamic models of sea level rise, tectonic and pulse tectonic uplift, sub-sidence, and sediment deposition. Starting with a DEM from the present day landscape, simulated DEM models are generated for the Early Helladic II/III (2500-2100BC), Classical (480-323BC), Hellenistic (323-146 BC), and Roman (1st Century BC – 4th Century AD Periods). The models shed light on archaeological interpretation concerning the continuity and discontinuity of human occupation in the Helike Delta. Moreover, the method demonstrates a new approach to dynamic landscape analysis using GIS that is general and can be applied to any landscape. Keywords: GIS, dynamic models, raster-based DEM, landscape analysis, geomorphology, geoarchaeology, Helike Delt