Ici vous trouverez les présentations issues des Conférences COMSOL à travers le monde. Réalisées par des utilisateurs de COMSOL Multiphysics, ces présentations explorent tous les domaines actuels d'innovation. Les applications couvrent pratiquement tous les secteurs industriels et impliquent des phénomènes électriques, mécaniques, fluidiques et chimiques. Utilisez la recherche rapide pour trouver les présentations les plus intéressantes dans votre domaine d'intérêt.

Detection of E.coli Cell using Capacitance Modulation

A.K. Dwivedi, R.M. Patrikar, R.B. Deshmukh, and G. Pendharkar
Visvesvaraya National Institute of Technology, Nagpur, Maharashtra, India

Testing and verification is very important to increase reliability of a system. In water analysis its purity is verified using different test methods. Biosensors are very useful to detect the microorganisms present in water. This paper presents a method to detect E.coli bacteria in water depending upon the capacitance modulation in the presence and absence of E.coli cell, which is simulated in ...

Microwave Inactivation of Bacteria Under Dynamic Heating Conditions in Solid Media

S. Curet[1], M. Mazen Hamoud-Agha[1]
[1]GEPEA, UMR 6144, CNRS, ONIRIS, Université de Nantes, Nantes, France

In this study, COMSOL®4.2a is used to model a microwave heating process in a TE10 rectangular waveguide. The sample consists of a small cylindrical Ca-alginate gel (D = 8 mm, H = 10 mm) inoculated with bacteria Escherichia Coli K12. The sample is placed along the microwave propagation direction into the waveguide. Maxwell’s equations and heat transfer are coupled to a microbial inactivation ...

Modeling of an Oxygenation-Aided 3D Culture for Functional Beta-Cell Expansion

S. Jin[1], J. McReynolds[1], X. Li[2], J. Guan[2]
[1]Department of Biomedical Engineering, College of Engineering, University of Arkansas, Fayetteville, AR, USA
[2]Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, USA

Currently, researchers are looking for ways to mass-produce biologically functional pancreatic beta cells in vitro because of the shortage of donor tissue needed for diabetes cell therapy. The beta cells will become hypoxic if their high oxygen demands are not met. We hypothesized that the biological function of beta cells can be improved if they are cultured in a 3D collagen scaffold, which ...

Aplicação de Elementos Finitos na Ortodontia

T. O. Bassani [1], T. Bassani [2], A. Andriguetto [1], F. Schneider [2],
[1] Instituto Latino Americano de Pesquisa e Ensino Odontológico - ILAPEO, Curitiba, PR, Brasil
[2] Universidade Tecnológica Federal do Paraná – UTFPR, Curitiba, PR, Brasil

O presente estudo visou a avaliação, por meio do método dos elementos finitos, das tensões geradas em um arco ortodôntico chamado de Arco de Retração Dupla Chave, também conhecido como DKL. Para isso foram modeladas as geometrias do arco DKL, dos bráquets e das coroas dentais, no software COMSOL Multiphysics®. O modelo criado tem como objetivo a substituição dos métodos tradicionais de ...

Modeling of Nerve Stimulation Thresholds and Their Dependence on Electrical Impedance with COMSOL

P. Krastev[1], and B. Tracey[1]
[1]Neurometrix, Inc., Waltham, Massachusetts, USA

Nerve localization is important for applications in regional anesthesia. Localization is achieved by stimulating the nerve with an electric field produced by a current from a needle inserted into the body of the patient, close to the target nerve.  Modeling of the electric field in close proximity to the nerve may help to explain observed variations in threshold currents and can help to ...

Simulation of Convection in Water Phantom Induced by Periodic Radiation Heating

H.H. Chen-Mayer[1], and R. Tosh[1]
[1]Ionizing Radiation Division, National Institute of Standards and Technology, Gaithersburg, Maryland, USA

Water calorimetry is employed to establish a primary reference standard for radiation dosimetry by measuring the temperature rises in a water phantom (a cube of about 30 cm x 30 cm x 30 cm) subjected to a beam of ionizing radiation.  We use COMSOL Multiphysics to model the system using the Heat Transfer module and the Incompressible Navier-Stokes module with a geometry of 2D-axial ...

Simulation and Design of a Microfluidic Respirometer for Semi-Continuous Amperometric Short Time Biochemical Oxygen Demand (BODST) Analysis

F.J. del Campo[1], A. Torrents[1], J. Mas[2], F.X. Muñoz[1]
[1]Instituto de Microelectronica de Barcelona, IMB-CNM (CSIC), Campus Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
[2]Departement de Genètica i Microbiologia, Campus Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain

Introduction: This work presents the design of a novel flow cell based miniaturized electrochemical respirometer to monitor organic content in water samples semi-continuously, in contrast to current Biochemical Oxygen Demand, BOD, methods. Simulation techniques has been used to parameterize and optimize aspects such as height and length of the channels, materials and thickness, flow and oxygen ...

An Assessment of the Suitability of the Body and Adult Head Coils for Transmission during Paediatric Magnetic Resonance Imaging

G.R. Cook[1], M.J. Graves[1], F.J. Robb[2], D.J. Lomas[1]
[1]Department of Radiology, University of Cambridge, Cambridge, United Kingdom
[2]General Electric Healthcare Coils, Aurora, Ohio, USA

MRI offers many advantages over other modalities and its lack of ionizing radiation is important for children, but can be limited by the radio-frequency (RF) coils available. This work calculates Specific Absorption Rate (SAR) and homogeneity of the RF transmit field (B1+) when imaging infants in adult coils. Two birdcage-type coils were loaded by a tissue model and their B1+ homogeneities ...

On the Influence of Cancellous Bone Structure upon the Electric Field Distribution of Electrostimulative Implants - new

U. Zimmermann[1], R.Bader[2], U. van Rienen[1]
[1]Institute of General Electrical Engineering, University of Rostock, Rostock, Germany
[2]Department of Orthopaedics, University Medicine Rostock, Rostock, Germany

Since the 1980s, the accelerating effect of electromagnetic fields on bone regeneration is used to treat complicated fractures and bone diseases. At the University of Rostock, an electrostimulative hip revision system is developed, basing on the method of Kraus-Lechner. This method requires an electric fields between 5 and 70 V/m. The bone used for the simulations consisted of two homogenous ...

Simulation of Normal and Cancerous T-cell Membrane Electroporation - new

O. Henao[1], V. Gómez[1], I. De la Pava[1], J. Sánchez[1]
[1]Grupo Fisiología Celular y Aplicada, Universidad Tecnológica de Pereira, Pereira, Risaralda, Colombia

Electroporation is an increase of the cell membrane permeability due to the formation of aqueous pores in it when the cell is under the influence of an intense electric field [1][2]. The formation of such pores in the membrane can be used to enhance the uptake of chemotherapeutic drugs into the cell in a cancer treatment known as electrochemotherapy [3]. In some cases the direct experimental ...