In questa sezione troverete i lavori presentati alle Conferenze mondiali COMSOL. Le presentazioni descrivono ricerche e prodotti innovativi progettati con COMSOL Multiphysics da colleghi di tutto il mondo. I temi delle ricerche presentate abbracciano un'ampia gamma di settori produttivi e aree applicative, in ambito elettrico, meccanico, fluidodinamico e chimico. Lo strumento di Ricerca Rapida vi permetterà di trovare le presentazioni che si riferiscono all'area di vostro interesse.

Thermal Simulation and Package Investigation of Wireless Gas Sensors

A. Paoli[1], L. Seminara[2], D.D. Caviglia[1], A. Garibbo[2], and M. Valle[1]

[1]Department of Biophysical and Electronic Engineering, University of Genova, Genova, Italy
[2]SELEX Communications S.p.A., Genova, Italy

Gas sensor arrays based on metal oxides operating at high temperature are commonly used in many application fields. They can operate on different principles and each sensor may show very different responses to the individual gases in the environment. Data coming from the array can be merged for reliable gas detection. One point which is common to the different sensors types is that the ...

Formation Of Porosities During Spot Laser Welding : Case Of Tantalum Joining

C. Touvrey
CEA Valduc, France

During the welding of tantalum with a ND: YAG pulsed laser, a deep and narrow cavity, called the keyhole, is formed. At the end of the process, surface tension forces provoke the collapse of the keyhole. For important interface deformations, gas bubbles can be trapped into the melting pool. If the solidification time is insufficient, these bubbles give birth to residual porosities. The aim of ...

Theory of Proportional Solenoids and Magnetic Force Calculation Using COMSOL Multiphysics

O. Vogel, and J. Ulm
Heilbronn University
Campus Künzelsau
Künzelsau, Germany

Proportional solenoids are well-known and used in a wide range of applications today. This paper is about methods of influencing the characteristic force-stroke-curves of magnetic actuators by means of different pole geometries. The conical design of the stator pole which is mostly used to accomplish proportional solenoids is analyzed by both a simple analytic reluctance model and a FEM model ...

Super-resolving Properties of Metallodielectric Stacks

N. Katte[1], J. Haus[1], J.B. Serushema[1], and M. Scalora[2]
[1]University of Dayton, Dayton, OH, USA
[2]Charles M. Bowden Research Center, Redstone Arsenal, AL, USA

We show that diffraction can be suppressed in a one-dimensional metallodielectric stack (MDS) at visible wavelengths to achieve super-resolution imaging. In our calculations we use two popular techniques, which can be adapted to investigate the imaging properties of MDSs. The two methods are the transfer matrix method (TMM) and the Finite element method based software, COMSOL Multiphysics. The ...

Time-Resolved Optical Tomography in Preclinical Studies: Propagation of Excitation and Fluorescence Photons.

F. Nouizi[1], R. Chabrier[1], M. Torregrossa[2], and P. Poulet[1]
[1]Laboratoire d’Imagerie et de Neurosciences Cognitives, Straßbourg, France
[2]Laboratoire des Sciences de l'Image, de l'Informatique et de la Télédétection, France

We present time-resolved methods that rely on near-infrared photons to image the optical properties and distribution of fluorescent probes in small laboratory animals. The coupled diffusion equations of excitation and fluorescence photons in highly scattering tissues were solved using the three-dimensional Finite Element Method (FEM) provided by COMSOL. The computed results allowed to yield ...

Study of Effect on Resonance Frequency of Piezoelectric Unimorph Cantilever for Energy Harvesting

G. R. Prakash[1], K. M. V. Swamy[1], S. Huddar[1], B. G. Sheeparamatti[1], Kirankumar B. B.[1]
[1]Basaveshwar Engineering College, Bagalkot, Karnataka, India

The focus of this paper is to study the effect on resonance frequency and power enhancement techniques[1] of piezoelectric MEMS and modeling, design, and optimization of a piezoelectric generator based on a two-layer bending element(Figure 1) using COMSOL Multiphysics. An analytical relation was developed based on the shift in resonance frequency(Figure 2) caused by the addition of a thin film ...

Solution of Inverse Thermal Problem for Assessment of Thermal Parameters of Engineered H2 Storage Materials

I. Fedchenia, and B. van Hassel
United Technologies Research Center
East Hartford, CT

Materials based H2 storage systems for light duty vehicles need to meet challenging performance targets that have been developed by the FreedomCAR and Fuel Partnership. On-board reversible metal hydrides are typically integrated with heat transfer surfaces, e.g. in fin and tube heat exchangers, in order to reject the heat of H2 absorption at a high rate which is set by the refueling time ...

Investigation of the Effect of Spinal Defects on Spondylolysis and Stress Fracture of Vertebral Bodies

M.S. Yeoman[1], C. Quah[2], A. Cizinauskas[1], K. Cooper[1], D. McNally[5], B. Boszczyk[2]
[1]Continuum Blue, Tredomen, Ystrad Mynach, United Kingdom
[2]The Centre for Spinal Studies and Surgery, Queen’s Medical Centre, Nottingham, United Kingdom
[5]Bioengineering Research Group, Faculty of Engineering, The University of Nottingham, Nottingham, United Kingdom

Spondylolysis (SL) is a defect of the spinal vertebra, and is typically caused by stress fracture of the pars interarticularis bone of the vertebral arch. It is especially common in adolescents who over train in sporting activities. Spina bifida occulta (SBO) is a malformation of the spine where the protruding vertebral bodies are not fully formed. In this study we demonstrate the predisposition ...

Modelling of Thermally Induced Electrical Instabilities in Intestine using COMSOL Multiphysics®

A. Gizzi[1][3], C. Cherubini[1][2], S. Migliori[1][3], and S. Filippi[1][2]
[1]Nonlinear Physics and Mathematical Modeling Lab, Engineering Faculty, University Campus Bio-Medico, Roma, Italy
[2]International Center for Relativistic Astrophysics, University of Rome La Sapienza, Roma, Italy
[3]Alberto Sordi Foundation, Research Institute on Aging, Roma, Italy

Postoperative or paralytic Ileus (PI) is a temporary aftermath of major abdominal surgeries. PI prevents the passage of food throughout the lumen leading to bloating, distension, emesis and pain. A plausible mathematical model for this phenomenology physiologically fine tuned including thermal variations, is presented here. Using COMSOL Multiphysics the existing intestinal ionic model have been ...

Stability Analysis of ALE-Methods for Advection-Diffusion Problems

A. Weddemann, and V. Thümmler
Bielefeld University, Germany

ALE-methods are frequently used to solve systems of partial differential equations (PDEs) on moving domains. The main idea of these methods is to incorporate the time evolution of the domain into the equations. However, the motion of the domain with respect to time induces convective fluxes in the resulting equations. These can lead to stability problems of the numerical method if they become ...