New insights into spatial characterization of turbulent flows: a complex network-based analysis

Despite much progress has been made, several mechanisms about turbulence dynamics are still unclear. We propose an innovative approach based on complex networks theory, which combines elements from graph theory and statistical physics, providing a powerful framework to investigate complex systems.The network is built on a forced isotropic turbulent field, by evaluating the temporal correlation of the kinetic energy for pairs of nodes within the Taylor microscale, λ. Among all the parameters analyzed, the degree centrality, k, is one of the most meaningful, representing how a node is linked to the others. We observe 3D patterns of high k values, which can be interpreted as regions of spatial coherence. The turbulent network exhibits typical behaviors of real and spatial networks (scale-free property). Similarly to other physical systems where complex networks successfully apply, our approach can give new insights for the spatial characterization of turbulence

Discrete modelling of continuous dynamic recrystallisation by modified Metropolis algorithm

Continuous dynamic recrystallisation (CDRX) is often the primary mechanism for microstructure evolution during severe plastic deformation (SPD) of polycrystalline metals. Its physically realistic simulation remains challenging for the existing modelling approaches based on continuum mathematics because they do not capture important local interactions between microstructure elements and spatial inhomogeneities in plastic strain. An effective discrete method for simulating CDRX is developed in this work. It employs algebraic topology, graph theory and statistical physics tools to represent an evolution of grain boundary networks as a sequence of conversions between low-angle grain boundaries (LAGBs) and high-angle grain boundaries (HAGBs) governed by the principle of minimal energy increase, similar to the well-known Ising model. The energy is minimised by a modified Metropolis algorithm. The model is used to predict the equilibrium fractions of HAGBs in several SPD-processed copper alloys. The analysis captures non-equilibrium features of the transitions from sub-grain structures to new HAGB-dominated grain structures and provides estimations of critical values for HAGB fractions and accumulated strain at these transitions

Guiding Ebola Patients to Suitable Health Facilities: An SMS-based Approach

We propose to utilize mobile phone technology as a vehicle for people to report their symptoms and to receive immediate feedback about the health services readily available, and for predicting spatial disease outbreak risk. Once symptoms are extracted from the patients text message, they undergo complex classification, pattern matching and prediction to recommend the nearest suitable health service. The added benefit of this approach is that it enables health care facilities to anticipate arrival of new potential Ebola cases