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.

Looking for the Origin of Power Laws in Electric Field Assisted Tunneling

H. Cabrera[1], D.A. Zanin[1], L.G. De Pietro[1], A. Vindigni[1], U. Ramsperger[1], D. Pescia[1]
[1]Laboratory for Solid State Physics, ETH Zurich, Zurich, Switzerland

A sharp tip approached perpendicular to a conducting surface at subnanometer distances and biased with a small voltage builds a junction across which electrons can be transferred from the tip apex to the nearest surface atom by direct quantum mechanical tunneling. Such a junction is used e.g. in Scanning Tunneling Microscopy (STM). When the distance d between tip and collector is increased ...

Empirical Model Dedicated to the Sensitivity Study of Acoustic Hydrogen Gas Sensors Using COMSOL Multiphysics®

A. Ndieguene[1], I. Kerroum[1], F. Domingue[1], A. Reinhardt[2]
[1]Laboratoire des Microsystèmes et de Télécommunications/Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
[2]Laboratoire d’Électronique et des Technologies de l’Information, CEA, LETI Grenoble, France

Due to the increasing demand for hydrogen gas sensors for applications such as automation, transportation, or environmental monitoring, the need for sensitive and reliable sensors with a short response time is increasing. This paper presents an empirical model that studies the sensitivity of acoustic hydrogen gas sensors. A parametric study based on the variation of physical properties of ...

Water Quality Model for Brewster Lake

Z. Aljobeh[1], G. Argueta[1]
[1]Valparaiso University, Valparaiso, IN, USA

A numerical model was developed to make spatial and temporal predictions of the water quality for Brewster Lake, located in southwestern Michigan. The model considers the hydrodynamics of the lake, hydrologic conditions, physical, chemical and biochemical processes that take place in the lake, and nutrient loadings from the surrounding watershed. Physical, chemical, and biochemical data ...

Modeling an Adsorption Process in a Shell-and-Tube-Heat-Exchanger-Type Adsorber - new

G. Salazar Duarte[1], B. Schürer[1], C. Voss[1], D. Bathen[2]
[1]Linde AG, Munich, Germany
[2]Universität Duisburg-Essen, Duisburg, Germany

Pressure Swing Adsorption (PSA) and Temperature Swing Adsorption (TSA) are commonly used for separation/purification of gas mixtures in industrial processes. The cycle time of industrial TSA processes usually ranges from several hours to days. The reason for this long cycle time is the usage of purge gas for heating and cooling the system (direct heating), which limits the application of TSA ...

Thermal Natural Convection Simulations with COMSOL Multiphysics® in Comparison with Measurements - new

H. van Halewijn[1]
[1]Fontys University of Applied Physics, Eindhoven, The Netherlands

In a laboratory setup a horizontal rod is heated on one side. By natural convection a stable temperature pattern is developed. Using the Nusselt formulation of the natural convection of cylindrical rods, the temperature distribution can be calculated. Only a good match of the simulations and the measurements can be reached when taking into account all the non-linear physics in the system. In ...

Geomagnetic Modeling with COMSOL Multiphysics® Software - new

G. Ha[1], S. S. Kim[1], J. H. Kim[1]
[1]Chungnam National University, Daejeon, Korea

Here we aim to advance geomagnetic modeling approaches using COMSOL Multiphysics® software and improve the degree of detail that can be obtained from the measured magnetic field. First, we carried out benchmark tests by comparing the computed results using the widely used analytic solutions for rectangular bodies with arbitrary direction of magnetization with those from the AC/DC Module of ...

Simulation of MEMS Based Pressure Sensor for Diagnosing Sleep Disorders

J. Vijitha[1], S. S. Priya[1], K. C. Devi[1]
[1]PSG College of Technology, Coimbatore, Tamil Nadu, India

Sleep apnea is a type of sleep disorder characterized by pauses in breathing or instances of shallow or infrequent breathing during sleep. There is a need to diagnose sleep apnea since it leads to fluctuations in the oxygen level that in turn affect the heart rate and blood pressure. In order to detect this disorder, a Micro Electro Mechanical System (MEMS) based piezoelectric pressure sensor ...

Optimum Design for Magneto-Rheological Brake Using COMSOL Multiphysics® Software

J. Thanikachalam[1], P. Nagaraj[1]
[1]Mepco Schlenk Engineering College, Sivakasi, Tamil Nadu, India

The Automotive industry has now become a technology of “Drive by Wire”. This technology is used to replace the conventional mechanical system by electromechanical system which is able to perform the same tasks faster, more reliably and accurately. The problems with the traditional braking systems are unreliable at high speeds, long respond time, more brake pad wear, high temperature operating ...

RF Magnetic Field Simulation of a Novel Planar DNP-NMR Coil

A.I. Dimitriadis [1], M. Soundararajan [1], D. Yoon [1], E. de Rijk [2], J.-Ph. Ansermet [1]
[1] Institute of Condensed Matter Physics, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne, Switzerland
[2] SWISSto12 SA, Lausanne, Switzerland

INTRODUCTION: Nuclear magnetic resonance (NMR) spectroscopy is a broadly used research technique that exploits the magnetic properties of atomic nuclei with non-zero spin in order to determine the physical/chemical properties of the molecules in which they are contained. However, NMR has fundamental sensitivity limitations, as a consequence of the small energy difference between nuclear spin ...

Predicting Critical Current as a Function of Magnetic Field in High-Temperature Superconductors

J. Doody [1], P. Michael [1], R. Vieria [1], W. Beck [1], L. Zhou [1], J. Irby [1],
[1] Massachusetts Institute of Technology - Plasma Science and Fusion Center, Cambridge, MA, USA

REBCO tapes belong to a class of high-temperature superconductors (HTS) that can be superconducting at liquid nitrogen temperatures (77K) as opposed to typical superconductors such as Nb3Sn which need to operate at liquid helium temperatures (4K). One important aspect of designing a super conducting coil is the ability to predict the critical current above which the conductor becomes ...