Charles Stark Draper Laboratory
Micromechanical resonators are used in a wide variety of applications, including inertial sensing, chemical and biological sensing, acoustic sensing, and microwave transceivers. Despite the distinct design requirements for each of these applications, a ubiquitous resonator performance parameter emerges. This is the resonator’s Quality factor (Q), which describes the mechanical energy damping. ...
Gaillard, N., Pinzelli, L., Gros-Jean, M., Bsiesy, A.
In recent years, a large variety of high dielectric constant materials has been studied as an alternative to silicon dioxide in order to improve the electrical properties in many integrated devices. The authors pointed out MIM electrical properties modifications such as current-voltage shift and the decrease in the voltage gap between the different conduction mechanisms voltage threshold while ...
Kalavagunta, A., Weller, R.A.
Vanderbilt University, Nashville, TN
The four-point probe is a tool for measuring the resistivity of a material by contact with its surface. The tool is widely used in the semiconductor industry and has applications both in research and manufacturing. The method though is quite sensitive to various paramaters like the substrate material, probe separation, probe depth etc. In this paper we show that COMSOL multiphysics can be used ...
Finite-element Analysis of Properties in Real and Idealized Photonic Crystal Fibres, Application to Supercontinuum Generation
Gérôme, F., Viale, P., Tombelaine, V., Leproux, P., Auguste, J.L., Février, S., Blondy, J.M., Couderc, V.
IRCOM, CNRS UMR 6615, Limoges, France
Using a full-vector finite-element method, we calculate modal properties in index-guiding photonic crystal fibres. The influence of the deformation of the geometry in actual fibre structures is evaluated and compared to the idealized-model. These results are applied to the supercontinuum generation. Moreover, development of MATLAB softwares for FEMLAB 3.1 are presented.
Nestlé Waters Italy
Shelf life estimation is a very important issue in the beverage industry. Depending on the packaging application, estimation of the carbon dioxide loss through the plastic bottle walls has always been desirable and challenging at the same time. In this work an FEM approach is presented, which is shown to be able to replace time consuming, expensive lab tests. Gas permeability through the ...
Zampolli, M., Tesei, A., Jensen, F.B.
NATO Undersea Research Centre, 19138 La Spezia, Italy
Acoustic waves are used in SONAR systems for the detection and classification of objects which may be swimming in the water column, proud on the seafloor, or buried below the sediment. In some applications, such as low frequency detection and classification of structurally complex objects immersed in a fluid, signal processing techniques must be aided by a-priori model based knowledge of the ...
Åberg, J., Vynnycky, M., Fredriksson, H.
KTH/Metallernas Gjutning, Stockholm, Sweden
This paper reports on progress in the implementation of COMSOL Multiphysics 3.2 to model thermal stresses in a three-dimensional solidifying shell, as occurs typically in the industrial continuous casting of copper, copper alloys and steel. Computer memory requirements prohibit a direct 3D numerical simulation of the temperature and the stresses. Instead, we use the fact that casting ...
Karpov, S., Krichtafovitch, I.
Kronos Air Technologies, Redmond, Washington
Electrohydrodynamic flow is a flow of electrically neutral gas caused by corona-generated charged particles (ions) drifting through it. The operation principles of electrostatic fluid accelerators that use corona discharge phenomenon can be described as following. High voltage applied between high curvature corona electrode and low curvature collecting electrode provides condition for ionization ...
Numerical simulations of heat effects compared to measurements in III-V semiconductor saturable absorbers.
LePaul, S., Yang, N., Aniel, F.
Institut d’Electronique Fondamentale, Université Paris XI – CNRS UMR 8622, Orsay
The major purpose of this communication is to share our experiences on the numerical difficulties we ended up in simulating heating effects of saturable absorbers based on III-V semiconductors with the commercial finite element software FEMLAB 3.1. Saturable absorbers are devices devoted to full optical signal regeneration in optical telecom systems. The self heating effects in the structures ...
Forssén, C., Edin, H
Electrotechnical Design, KTH - Electrical Engineering
Partial discharges are localized electric discharges that do not bridge the electrodes. For high voltage components measurements of partial discharges are commonly used to diagnose the condition of the insulation system. Traditionally partial discharges are measured at a single frequency of the applied voltage. However the rather newly developed technique of Variable Frequency Phase Resolved ...