Here you will find presentations given at COMSOL Conferences around the globe. The presentations explore the innovative research and products designed by your peers using COMSOL Multiphysics. Research topics span a wide array of industries and application areas, including the electrical, mechanical, fluid, and chemical disciplines. Use the Quick Search to find presentations pertaining to your application area.

Effect of Local Deformation on the Emission Energy of  Quantum Dots in a Flexible Tube

S. Kiravittaya[1], P. Cendula[2], A. Rastelli[2], and O. Schmidt[2]
[1]Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
[2]Institute for Integrative Nanosciences, Dresden, Germany

Strain induced by local deformation of a flexible micrometer-sized semiconductor tube is quantified by modeling a ball pressing on the tube wall. By changing the pressing condition, we are able to change the strain state of the tube wall incorporating self-assembled quantum dots (QDs) in the wall. The QD emission energy is calculated in COMSOL® by solving the Schrödinger wave equation ...

Electrical Impedance Sensor to Detect Tunnels and Infrastructure in Soil  

R. Gamache, and D. Spinelli
TransTech Systems, Inc., Schenectady, NY, USA

Tunnels and their detection have been a problem in warfare since the ancient world. Recent events have highlighted the ongoing problems of tunnels and the difficulties in locating them, not only in military situations, but also in law enforcement and homeland security applications as well. Electromagnetic and acoustic or seismic techniques may provide the significant advantage of a mobile non ...

Design and Characterization of a Small Volume Reactor for the High Pressure Invacuo Study of Catalytic Surface Reactions

C. Clark[1,2], J. Fulton[3], T. Adams[3], E. Podgornov[4], and F. Zaera[4]
[1]Department of Chemical and Environmental Engineering, University of California, Riverside, CA, USA
[2]Naval Surface Warfare Center, Corona, CA, USA
[3]Naval Surface Warfare Center, Crane, IN, USA
[4]Department of Chemistry, University of California, Riverside, CA, USA

The design and construction of ultra-high vacuum (UHV) systems for the study of surface reactions has lead to high impact innovation in a myriad of industries. A small volume reactor compatible with ultrahigh vacuum (UHV) surface-science instrumentation has been designed, modeled and tested for the study of the kinetics of surface chemical reactions on single crystals. CO oxidation experiments ...

Microscale Modelling of the Frequency Dependent Resistivity of  Porous Media

J. Volkmann, O. Mohnke, N. Klitzsch, and R. Blaschek
E.ON Energy Research Center, RWTH-Aachen, Aachen, Germany

The frequency dependent electrical impedance of porous media is studied by modelling the charge transport in the electrolyte filled pore space using COMSOL Multiphysics.  The corresponding experimental method, called Spectral Induced Polarization (or Impedance Spectroscopy), shows a frequency dependent phase shift between a measured electric current and an applied alternating voltage. It is ...

Modeling of snRNP Motion in the Nucleoplasm

M. Blaziková[1], J. Malínský[2], D. Stanek[3], and P. Herman[1]
[1]Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
[2]Institute of Experimental Medicine, Prague, Czech Republic
[3]Institute of Molecular Genetics, Prague, Czech Republic

Small nuclear ribonucleoprotein particles (snRNPs) are essential supramolecular complexes involved in pre-mRNA splicing, the process of post-transcriptional RNA modifications. The particles undergo complex assembly steps inside the cell nucleus in a highly dynamic compartment called the Cajal body. We have previously shown that the free diffusion model does not fully describe the snRNP motion ...

Analyzing a Malfunctioning Clarifier with COMSOL’s Mixture Model

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 ...

Development and Characterization of High Frequency Bulk Mode Resonators

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 ...

Parameter Optimization for Finite-Element Method (FEM) based modeling of singlet oxygen during PDT

T. Zhu, and K. Wang
Department of Radiation Oncology, School of Medicine, University of Pennsylvania, Philadelphia, PA, USA

Photodynamic therapy(PDT) is a new cancer treatment modality using the photochemical reaction of a photosensitizing drug, light, and oxygen. The objective of this project is to determine the photochemical parameters necessary for singlet oxygen modeling during PDT using parameters obtained from a microscopic model.   FEM calculation in COMSOL Multiphysics was used to determine the model ...

Localization of Chemical Sources Using Stochastic Differential Equations in Realistic Environments

A. Mohammed, and A. Jeremic
McMaster University, Hamilton, L8S4K1, Canada

Signal processing algorithms for chemical sensing/monitoring have been subject of considerable research interest in the recent years mainly due to their diverse applicability. When the concentration of chemical agent is small, the dispersion of particles is governed by stochastic differential equations describing more complex motion mechanisms such as Brownian motion. In this paper we propose ...

Computational Analysis of the Mechanical and Thermal Stresses in a Thin Film PProDOT-Based Redox Capacitor

J. Sotero-Esteva[1], M. Rosario-Canales[2], P. Gopu[3], and J. Santiago-Avilés[3]

[1]Department of Mathematics, University of Puerto Rico at Humacao, Humacao, PR
[2]Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
[3]Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, USA

Among the several types of capacitors, the double-layer and redox types have gathered increasing attention to address some of the heavy power demands of modern technology. In redox capacitors, charge is stored chemically via oxidation/reduction processes in the active materials like electroactive polymers (EAPs) or metal oxides. This work investigates the stresses and heat flux of the electrode ...

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