J. Orjuela, and A. González
Dept. de Ingeniería Química Facultad de Ingeniería
Universidad de los Andes
A bidimensional and pseudo homogenous model was proposed for the study of mass transfer in the bioadsorption process of chromium VI in the S-layer of immobilized Bacillus sphaericus in a packed column. The implementation of such a model in COMSOL Multiphysics will be explained in detail and the final results presented. These include chromium concentration profiles along the column and its ...
M. A. Chetoui , O. Boiron , A. Dogui , V. Deplano ,
 Université de Monastir, Ecole Nationale D'ingénieurs de Monastir; Ecole centrale Marseille, Marseille, France
 Aix-Marseille Université, CNRS, Ecole Centrale, Marseille, France
 Université de Monastir, Ecole Nationale D'ingénieurs de Monastir, Marseille, France
Intervertebral discs (IVD) are fibro-cartilages situated between vertebrae providing their joint flexibility. They play a major role in the transmission and absorption of load through the spine. The disc can undergo progressive structural and quantitative changes in its composition and morphology related to mechanical load applied to the spine which can lead to disc degeneration; this disease is ...
COMSOL Multiphysics for Efficient Solution of a Transient Reaction-Diffusion System with Fast Reaction
M.K. Gobbert, A. Churchill, G. Wang, and T.I. Seidman
Department of Mathematics and Statistics, University of Maryland, Baltimore County, Baltimore, Maryland, USA
A reaction between chemical species is modeled by a particular reaction pathway, in which one reaction is very fast relative to the other one. The diffusion controlled reactions of these species together with a reaction intermediate are described by a system of three transient reaction diffusion equations over a two-dimensional spatial domain. In the asymptotic limit of the reaction parameter ...
O. Kraft , J. Gaiser , M. Stripf ,
 University of Applied Sciences, Karlsruhe, Baden-Würtemberg, Germany
Standard measuring techniques for thermal conductivity cannot be readily applied to determine the load-dependent thermal conductivity of porous adsorbents, because the local ad- and desorption inside the specimen and the thickness of the specimen are not considered. Hence, in this work a new measuring procedure combining the transient hot bridge (THB) with a three dimensional finite element ...
Simeon Cavadias , Cédric Guyon , Gerrardo Vera De la Cruz ,
 Institut Pierre-Gilles de Gennes (IPGG) - UPMC, France
 Chimie-ParisTech - Institut Pierre-Gilles de Gennes (IPGG) , France
 Master Nuclear Energy, ISTN (Saclay), France
Emulsions, small liquid droplets of oil in water or water in oil, find wide application in, pharmaceutical products, fine chemicals, analytical chemistry. Microfluidic devices allow creation of uniform droplets with a tight distribution. The COMSOL Multiphysics® software model presented here is an extension of the tutorial “Droplet Breakup in a T- junction”. In this tutorial uniform droplets ...
A. de Niet, A. van Nieuwenhuijzen, and A. Geilvoet
Witteveen+Bos, Deventer, The Netherlands
Clarifiers are used to separate sludge and water in waste water treatment plants. In this paper we analyze a malfunctioning clarifier using the mixture model. We are able to receive model results that are reasonably close to measurements from the real clarifier. With the model we can explain the bad separation of water and sludge in the clarifier. Engineers have proposed several actions in order ...
A. Warning, A. K. Datta
Department of Biological & Environmental Engineering, Cornell University, Ithaca, NY, USA
Predictive food microbiology currently first requires experimental data for growth on fresh produce and then fitting an empirical or semi-empirical model to the data, making extrapolation to other conditions (temperature, type of produce) difficult. Herein, we develop a mechanistic model for the growth of human pathogenic bacteria (Escherichia coli O157:H7 and Salmonella spp.) on spinach using ...
M. Nickaeen , I. L. Novak , A. Mogilner , B. M. Slepchenko ,
 Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT, USA
 Courant Institute and Department of Biology, New York University, New York, NY, USA
A recently published conservative algorithm for simulating reactions and transport in moving domains have been extended to models in which cell kinematics are coupled with intracellular dynamics. For this, the method that combines a Eulerian approach with tracking an explicit boundary was linked to FronTier, a robust front-tracking technique. The extended algorithm was validated using a set of ...
Study of a Self Heating Process of Tetrafluoroethylene by the Exothermic Dimerization Reaction to Octafluorocyclobutane
M. Beckmann-Kluge, H. Krause, V. Schröder, A. Acikalin, and J. Steinbach
Federal Institute for Materials Research and Testing, Berlin, Germany
Technical University Berlin, Berlin, Germany
The self heating process of Tetrafluoroethylene caused by an exothermic dimerization reaction was studied. The heat of reaction can lead to a thermal explosion by the decomposition of the Tetrafluoroethylene. Different reaction kinetics, including multistep kinetics, were used to describe the mass balance. The COMSOL Chemical Engineering Module was used to perform the simulation which was ...
O. Rouaud, T. Pham
LUNAM Université, ONIRIS, CNRS, GEPEA, UMR, Nantes, France
University of New South Wales, Sydney, Australia
A mathematical model is developed to determine the weight loss and the freezing rate during the freezing of unwrapped foodstuffs. The model allows comparing two freezing processes; the first uses nitrogen gas at -80°C and the second uses cold air. The model includes thermophysical properties that are temperature dependent to take into account the ice formation. The time step has to be chosen ...