Multiphysics finite – element modelling of an all – vanadium redox flow battery for stationary energy storage

All-Vanadium Redox Flow Batteries (VRFBs) are emerging as a novel technology for stationary energy storage. Numerical models are useful for exploring the potential performance of such devices, optimizing the structure and operating condition of cell stacks, and studying its interfacing to the electrical grid. A one-dimensional steady-state multiphysics model of a single VRFB, including mass, charge and momentum transport and conservation, and coupled to a kinetic model for electrochemical reactions, is first presented. This model is then extended, including reservoir equations, in order to simulate the VRFB charge and discharge dynamics. These multiphysics models are discretized by the finite element method in a commercial software package (COMSOL). Numerical results of both static and dynamic 1D models are compared to those from 2D models, with the same parameters, showing good agreement. This motivates the use of reduced models for a more efficient system simulation

The effect of a secondary task on kinematics during turning in Parkinson's disease with mild to moderate impairment

Patients with Parkinson's disease (PD) show typical gait asymmetries. These peculiar motor impairments are exacerbated by added cognitive and/or mechanical loading. However, there is scarce literature that chains these two stimuli. The aim of this study was to investigate the combined effects of a dual task (cognitive task) and turning (mechanical task) on the spatiotemporal parameters in mild to moderate PD. Participants (nine patients with PD and nine controls (CRs)) were evaluated while walking at their self-selected pace without a secondary task (single task), and while repeating the days of the week backwards (dual task) along a straight direction and a 60 degrees and 120 degrees turn. As speculated, in single tasking, PD patients preferred to walk with a shorter stride length (p< 0.05) but similar timing parameters, compared to the CR group; in dual tasking, both groups walked slower with shorter strides. As the turn angle increased, the speed will be reduced (p< 0.001), whereas the ground-foot contact will become greater (p< 0.001) in all the participants. We showed that the combination of a simple cognitive task and a mechanical task (especially at larger angles) could represent an important training stimulus in PD at the early stages of the pathology

Automatic Classification of eruptive events by the VAMOS system

An automatic system named VAMOS (Volcanic Activity MOnitoring System) for monitoring volcanic activity at Mt. Etna and Stromboli volcanoes, is at the present under test at the data collection center at IIV (Istituto Internazionale di Vulcanologia, CNR, Catania). This system allows automatic recognition of volcanic activity by on-line processing of images collected by the surveillance cameras positioned close to the summit crater of two above mentioned volcanoes which are worldwide known to be characterized by a persistent eruptive activity. Based on this automatic system, a new software tool to extract quantitative information from collected images is now under developing. Several tasks have been planned to solve by using this tool such as the automatic classification of recorded events and the computation of relaxed energy based on stereo-vision and thermal images. One of the first result of the undertaken research activity has been the automatic classification of the type of volcanic events and the localization of the eruptive event

Adjusted Light and Dark Cycles Can Optimize Photosynthetic Efficiency in Algae Growing in Photobioreactors

Biofuels from algae are highly interesting as renewable energy sources to replace, at least partially, fossil fuels, but great research efforts are still needed to optimize growth parameters to develop competitive large-scale cultivation systems. One factor with a seminal influence on productivity is light availability. Light energy fully supports algal growth, but it leads to oxidative stress if illumination is in excess. In this work, the influence of light intensity on the growth and lipid productivity of Nannochloropsis salina was investigated in a flat-bed photobioreactor designed to minimize cells self-shading. The influence of various light intensities was studied with both continuous illumination and alternation of light and dark cycles at various frequencies, which mimic illumination variations in a photobioreactor due to mixing. Results show that Nannochloropsis can efficiently exploit even very intense light, provided that dark cycles occur to allow for re-oxidation of the electron transporters of the photosynthetic apparatus. If alternation of light and dark is not optimal, algae undergo radiation damage and photosynthetic productivity is greatly reduced. Our results demonstrate that, in a photobioreactor for the cultivation of algae, optimizing mixing is essential in order to ensure that the algae exploit light energy efficiently

Vapor-Liquid Equilibria in Polymer Solutions With Non-Polar Solvents by a Modified Redlich-Kwong-Soave Equation of State

No abstract available

Coefficienti di Attività a Diluizione Infinita di Diversi Solventi in Polimeri Comb e Dendritici

No abstract available