Numerical Simulations of Radionuclide Transport through Clay and Confining Units in a Geological Repository using COMSOL
J. Hansmann, M. L. Sentis, B. J. Graupner, A.-K. Leuz, C. Belardinelli
Swiss Federal Nuclear Safety Inspectorate (ENSI), Brugg, Switzerland
Kantonsschule Solothurn, Solothurn, Switzerland
Introduction: The sectoral plan that defines the procedure and criteria of site selection for deep geological repositories for all categories of waste (high-level and low- and intermediate-level waste) in Switzerland started in 2008 and will last for about ten years. ENSI (Swiss Nuclear Safety Inspectorate) is in charge of reviewing the proposals and safety assessments for geological ...
G. Zhang, S. Bearden
Clemson University, Clemson, SC, USA
It is necessary to understand and control nanopore behavior in order to develop biosensors for a variety of applications including DNA sequencing. The fluidics of nanopore devices we fabricated exhibits a range of interesting phenomena, such as enhanced conductance and current rectification. By electrically biasing nanopores, we were able to actively control the nanopore conductance in real time ...
Microscale Simulations of Catalyst Deactivation During Gas-Phase Upgrading of Biomass Pyrolysis Vapors
P. N. Ciesielski , D. Robichaud , B. Donohoe , M. Nimlos ,
 Biosciences Center, National Renewable Energy Laboratory, Golden, CO, USA
 National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, USA
Catalytic fast pyrolysis is a process by which biomass may be converted into liquid hydrocarbon transportation fuels and chemical co-products that are alternative to their petroleum-derived counterparts. Chemical compounds in raw pyrolysis vapor have high oxygen content and therefore must be deoxygenated in order to meet specifications for hydrocarbon fuels. One strategy to accomplish this is ...
Fundamental Three Dimensional Modeling and Parameter Estimation of a Diesel Oxidation Catalyst for Heavy Duty Trucks
A. Holmqvist and C.U.I. Odenbrand
Department of Chemical Engineering, Faculty of Engineering, LTH, Lund University, Lund, Sweden
Mathematical optimization can be used as a computational engine to generate the best solution for a given problem in a systematic and efficient way. In the context of monolithic converter systems, the parameter estimation problem (or inverse problem) is solved using Partial Differential Equations (PDE)-based models of the physical system coupled with an optimization algorithm. These problems are ...
Modeling Of A Strongly Coupled Thermal, Hydraulic And Chemical Problem: Drying And Low-Temperature Pyrolysis Of Chromated Copper Arsenate (CCA)-Wood Waste Particles In A Moving Bed Reactor
J. Govaerts, and L. Helsen
SCK-CEN, Belgian Nuclear Research Centre, Performance Assessment Unit, Mol, Belgium
Department of Mechanical Engineering, Division of Applied Mechanics and Energy Conversion, Katholieke Universiteit Leuven, Heverlee, Belgium
Low temperature thermal carbonisation might be the ultimate solution to the growing disposal problem of CopperChromeArsenic-treated waste wood. This energy and material recuperating technology is currently in the process of upscaling to an industrial level. In the present study, a numerical model is developed in COMSOL Multiphysics that allows to investigate the temperature profiles, gas ...
A. Warning, A. K. Datta, A. Dhall, and D. Mitrea
Department of Biological and Environmental Engineering
A multiphase porous media model involving heat and mass transfer within a potato chip was implemented in COMSOL 3.5a. The diffusive flux in oil and liquid water was modeled from capillary driven flow while the gas phase was modeled using binary diffusion. A non-equilibrium water evaporation rate was used and Darcy's law for the momentum equation to solve for the convection of each species. ...
R. Samso, N. Forquet, P. Molle, J. Garcia
Department of Hydraulic, Maritime and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, Barcelona, Spain
IRSTEA, Freshwater Systems, Ecology and Pollution Research Unit, Villeurbanne, France
Horizontal-Flow Constructed Wetlands (HFCWs) are a particular type of biofilter, and as such they rely mostly on the activity of bacterial communities to treat wastewater. Bacterial growth in HFCWs induces dramatic changes in its hydraulic and hydrodynamic behaviour (bioclogging), which may eventually result in overland flow of wastewater. Consequently, clogging is the main cause of premature ...
Modelling and Simulation of Simultaneous Intrinsic Kinetics, Hydrogen Transport and Heat Transfer in Complex Hydride Hydrogen Storage Systems
G. A. Lozano, J. M. Bellosta von Colbe, T. Klassen, and M. Dornheim
Institute of Materials Research
In proper designs of hydrogen storage systems based on metal hydrides three processes are modelled and simulated: hydrogen flow (through the metal hydride bed), solid-state chemical transformation, and heat transfer (due to the highly exothermic chemical transformation). In this work, modelling and simulation of the hydrogenation in complex hydride tanks is performed using COMSOL, case study is ...
Research & Technology
Rick has a BS in Physics, a ScM in Geological Sciences, and a PhD in Physics. He worked at Air Force Geophysics Laboratory, Conoco Petroleum Exploration Research, and, since 1989, has been at the DuPont Experimental Station. In this industrial setting, Rick has had opportunity to work on a great diversity of problems ranging from traditional engineering studies, using commercial finite-element ...
J. Ebert, S. Ghosal, A. Emami-Naeini
SC Solutions, Sunnyvale, CA, USA
This paper describes the development of a COMSOL model of Electro-Chemical-Mechanical Planarization (ECMP) that was validated with experimental data. ECMP is used for processing of semiconductor wafers. We developed a 2D model of flow of phosphoric acid solution (the electrolyte) between two parallel plates that focuses on the physics and electrochemistry in ECMP. The model includes steady-state ...