B. Bunner , A. Kromidas , M. Kele , and U. Neue
Waters Corp, Milford, MA, USA
High-Performance Liquid Chromatography (HPLC) is a standard method in the pharmaceutical industry for the separation and identification of chemical compounds. Modeling of band transport, or band broadening phenomena, can provide tremendous insight into problems of chromatography that are difficult or impossible to measure experimentally. We used COMSOL to analyze two classes of problems in ...
J.L.Wilson, and R. Dwivedi
New Mexico Institute of Mining and Technology, Socorro, New Mexico, USA
Geothermally driven natural convection in enclosures is a ubiquitous process occurring in many physical environments such as caves, mines, etc. We have numerically simulated laminar and turbulent natural convection in isolated air-filled cavities, buried in a more conductive rock mass. We have modeled heat transfer using COMSOL's Convection and Conduction mode. To better understand the ...
S. Lefeuvre, and O. Gomonova
Eurl Creawave, Toulouse, France
Siberian State Aerospace University, Krasnoyarsk, Russia
The microwave heating and processing of heterogeneous material is usually simulated using a set of coupled PDE equations in an homogeneous medium. Nowadays it is possible to describe more accurately the process with a suitable description of the heterogeneities that is at the grain level. Many authors work with spheres (circles) to represent the grains but it is difficult to achieve an ...
S.M. Musa, M.N.O. Sadiku, and O.D. Momoh
Prairie View A&M University, Prairie View, TX, USA
Indiana University-Purdue University, Fort Wayne, IN, USA
This paper presents an analysis approach of multicondcutor quasi-TEM lines transmission interconnect in a single dielectric region and multimode waveguides using the finite element method (FEM). FEM is especially suitable and effective for the computation of electromagnetic fields in strongly inhomogeneous media. We illustrate that FEM is suitable and effective as other methods for modeling of ...
R. Cumeras, I. Gràcia, E. Figueras, L. Fonseca, J. Santander, M. Salleras, C. Calaza, N. Sabaté, and C. Cané
Instituto de Microelectrónica de Barcelona, Barcelona, Spain
A micro Planar Ion Mobility Spectrometer (P-FAIMS) has been simulated using multiphysics software. In P-FAIMS target ions are discriminated by the application of the proper separation voltages to the electrodes of the system. Modelling of vapour phase ions of two compounds have been studied for different values of electric field amplitude to gas number density (E/N) ratio: a health risky ...
E. Engström, B. Balfors, and R. Thunvik
Royal Institute of Technology, Stockholm, Sweden
In this study we evaluate transport, retention and subsistence of Escherichia coli (E. coli), a common fecal indicator bacteria, in a model (2x1m) of a constructed wetland. Transport occurs in the unsaturated and saturated zone. Inactivation is accounted for as a kinetic first-order process. Retention is assumed to be dominated by solid-air-water interface straining and is modeled with a kinetic ...
W. Booth, J. Schiffbauer, and B. Edwards
West Virginia University
Star City, WV
Ion-selective membranes can be used in lab-on-a-chip devices for various portable applications in this field. These devices can be used as concentrators for analytical chemistry and for micro-scale filtration. Here, a binary aqueous electrolyte solution in a microchannel has a potential bias applied across it and it is driven through an ion-selective membrane. Ion concentration gradients form ...
A. J. Kovacs, and M. Nemenyi
University of West Hungary
Institute of Biosystems Engineering
Our Institute at the West Hungarian University is dealing with modelling of heat physical treatments in agricultural (biological) materials. The essential key in order to gain accurate results is to know the driving forces during heat and mass transfers. In case of mass transfer processes the application of moisture gradient as driving force gives false results. Therefore, we use water ...
A. Talic, S. Cerimovic, M. Mutapcic, R. Beigelbeck, and F. Keplinger
Institute for Integrated Sensor Systems, Austrian Academy of Sciences, Wiener Neustadt, Austria
Institute of Sensor and Actuator Systems, Vienna University of Technology, Vienna, Austria
We present COMSOL-based analyses and design optimizations of a micromachined wind sensor. The sensor relies on eight germanium thermistors embedded in a thin silicon nitride membrane, where two orthogonally arranged ensembles, each consisting of four thermistors, are connected to form a double Wheatstone-bridge. In operation, each bridge is supplied by a constant current and the self-heating of ...
G. Rosi, L. Teresi, A. DiCarlo, and F. dell'Isola
LaMS - Università degli Studi Roma Tre, Roma, Italy
Università degli Studi di Roma "La Sapienza", Roma, Italy
Liquid crystals - as all liquids - are generally modelled as incompressible media. In fact, mass-density changes occurring in these mesophases are minuscule and inconsequential in most regimes of interest. However, liquid crystals exhibit also phenomena that call for a more refined theory. In particular, it is experimentally well established that the Fréedericksz transition - i.e., the sudden ...