L. Meacci, A. Farina, F. Rosso, I. Borsi, M. Ceseri, and A. Speranza
Dipartimento di Matematica U. Dini, Università degli Studi di Firenze, Firenze, Italy
The problem is to understand how a geothermal field can evolve from a water dominated state into a vapor dominated one. A first answer to this question is given by a simplified mathematical model of the dynamics of a geothermal field in which the geothermal fluid is entirely composed by pure H2O. We considered a 1-D geometry and we developed a dynamic model that presents a clear interface ...
High Coupling Factor Piezoelectric Materials for Bending Actuators: Analytical and Finite Elements Modeling Results
I.A. Ivan, M. Rakotondrabe, and N. Chaillet
FEMTO-ST Institute, University of Franche-Comte, Besançon, France
New giant piezoelectric factor materials such as PMN-PT and PZN-PT were researched during the last decade and are actually becoming commercially available. As they seem very attractive for actuator designs, we studied their potential in replacing PZT ceramics. In a first comparative approach, we tested a series of classic rectangular composite bimorph structures of different combinations of ...
E. Carminati and P. Petricca
Dipartimento di Scienze della Terra, Università di Roma La Sapienza, Roma, Italy
Using 2D viscoelastic plane strain models we investigate the dependency of the stress field of slabs on geometry and kinematics of subduction zones (relative velocity of interacting plates and their absolute velocity with respect to the mantle). We conclude that the concentration of Von Mises stress is controlled by the geometry (curvature) of the slab and that downdip compression in subducting ...
A. Priarone, S. Lazzari, and E. Zanchini
Dipartimento di Ingegneria Energetica, Nucleare e del Controllo Ambientale, Alma Mater Studiorum - Università di Bologna, Bologna, Italy
The long-term performance of double U-tube Borehole Heat Exchangers (BHEs) is studied numerically by considering three different time-dependent heat fluxes exchanged between each BHE and the ground. Since the temperature distribution along the vertical direction has a negligible influence on long-term BHE performance, the problem is studied by means of a 2D conduction model, where the energy ...
A. E. Khabbazi, A.J. Richards, and M. Hoorfar
School of Engineering, UBC Okanagan, Kelowna, BC Canada, Canada
Using COMSOL Multiphysics 3.5, a numerical model has been developed to determine the effect of the channel geometry and electrode configuration on cell performance based on polarization curves. The Butler-Volmer equation was implemented to determine the reaction rates at the electrodes. The Conductive Media DC module is used to model the electric fields within the fuel cell.
J. Torres, and D. Montane
Centre Huile Lourde Ouvert et Experimental (CHLOE), University of Pau, France
Department of Chemical Engineering, Virgili University, Tarragona, Spain
Steam Reforming of Ethanol using a Catalytic Wall Reactor (CWR) was successfully studied using COMSOL Multiphysics. A mathematical model was used to describe the reactor performance in terms of the main variables and dimensionless groups. Simulations showed that at specified conditions CWR maintains a thermal performance adequate for evaluating catalysts under a uniform temperature profile. CWR ...
H. Pakdast, Z. Davis
DTU Nanotech, Technical University of Denmark, Kgs. Lyngby, Denmark
This article describes the development of a bulk mode resonator which can be employed for detection of bio/chemical species in liquids. The goal is to understand the mechanical and electrical properties of a bulk mode resonator device which exhibit high frequency resonance modes and Q-factor. A high resonance frequency is desirable because a small change in the resonator’s mass, for ...
C. Trenado, D. Strauss[1,2], and M. Wittmar
Computational Diagnostics & Biocybernetics Unit, Saarland University Hospital, Homburg, Germany
Leibniz-Institute for New Materials, Saarbrücken, Germany
Progress in coating technology has allowed for the development of free-chromate corrosion inhibitors, which are able to smartly migrate when required. In order to support the coating design, we propose a hybrid mathematical model to study the inhibitor's release by taking into account the thermodynamics and kinetics involved in the corrosion process. The proposed model is ...
Electrical Stimulation of Brain using a realistic 3D Human Head Model: Improvement of Spatial Focality
A. Datta, M. Elwassif, and M. Bikson
Department of Biomedical Engineering, The City College of the CUNY, New York, NY, USA
We calculated the spatial distribution of the electric fields induced in the brain during transcranial current stimulation (TCS). The spatial focality obtained using ‘concentric-ring’ configurations is investigated using a realistic MRI derived 3D finite element model of the human head. Two disc electrode configurations were simulated using COMSOL Multiphysics. The distant-bipolar ...
Department of Chemical Engineering, M.I.T., Cambridge, MA, USA
Magnetic fluids containing nano or submicron magnetic particles and their application in food, biological and pharmaceutical systems have recently attracted increasing attention. Magnetic particles can be collected efficiently in magnetizable matrices (e.g. iron wires) in high gradient magnetic separation (HGMS) process. In this work, the dynamic buildup growth process is treated as a moving ...