M. J. Hampe, S. Lang, H. Löhn, and T. Zeeden
Technische Universität Darmstadt
Fachgebiet Thermische Verfahrenstechnik
PEM fuel cells based on Polybenzimidazole doped with phosphoric acid show many benefits in comparison to conventional perfluorinated sulfocationic membrane materials, but they suffer from a degradation partially caused by the loss of electrolyte. The first step to tackle this degradation problem is to understand the electrolyte management in high temperature PEMFCs. COMSOL 4.1 was used to ...
A. Galsa, and M. Herein
Numerical calculations have been carried out to quantify the effect of the eccentric position of normal electric borehole sondes on the current density distribution and the obtained specific resistivity. In the most calculations the distorting influence of the eccentricity (distance between the axis of the borehole and the sonde) on the specific resistivity is less than 2%, but in special cases ...
M. Mutke, and H.-D. Wiemhöfer
Institute of Inorganic and Analytical Chemistry
University of Muenster
In this contribution, ionic mass and charge transport in Li-battery electrolytes is modeled. In particular, incomplete dissociation of the Li-salt, which is a common feature of many commercial electrolytes and which has so far been neglected in most electrolyte models, is considered. For electrolytes in cells under various charging/discharging conditions, the development of local concentration ...
L. Rossini, O. Chételat, E. Onillon, Y. Perriard
Centre Suisse d’Electronique et Microtechnique – CSEM, Neuchâtel, Switzerland
Ecole Polytechnique Federale de Lausanne - EPFL, Lausanne, Switzerland
The reaction sphere is a magnetic bearing electromagnetic spherical actuator for satellite attitude control. The reaction sphere consists in a 3D motor composed of a 20-coil stator and an 8-pole permanent magnet rotor. The rotor is synthesized wit a mosaic of 728 cylindrical magnets glued on the rotor back-iron so as to approximate the selected magnetization pattern. These cylindrical magnets ...
Zeugin Bauberatungen AG
Especially in large offices and call centers the noise pollution of Employees and mutual disturbance is an actual problem. The existing distribution of the sound pressure level in a range of frequency from 100 – 250 Hz show significant noise pollution also at remote workplaces for the current state of the examined large office. For improvements the influence of compact wideband sound ...
J. P. Müller, and T. E. Schäffer
Institute of Applied Physics
University of Erlangen-Nuremberg
One method for investigating the mechanical properties of samples like living cells with an Atomic Force Microscope (AFM) is driving force-curves, i.e. measuring the force applied by the tip of the AFM as a function of the indentation into the sample. By fitting a Hertz-model, which predicts the applied force as a function of the indentation depth, one can infer the elastic modulus of the ...
T. Zandt, C. Gaiser, and B. Fellmuth
Physikalisch-Technische Bundesanstalt (PTB)
The finite-element method (FEM) is a well-established computational methodology for the numerical treatment of partial differential equations. It is primarily used for solving problems in applied engineering and science. In this paper, specific examples are discussed to show how FEM was used for treating problems in temperature metrology, namely primary thermometry applying Dielectric-Constant ...
D. P. Elford, L. Chalmers, F. V. Kusmartsev, and G. M. Swallowe
Department of Physics
The results of numerical modelling of sonic crystals with resonant array elements are reported. The acoustic band structure and transmission characteristics of such systems have been computed with the use of finite element methods. An existence of a separate attenuation mechanism associated with the resonant elements, which increases performance in the lower frequency regime has been ...
S. Kelly, and M. Turner
National Centre for Plasma Science and Technology
Dublin City University
Fluid model calculations are a useful method to simulate the chemistry rich plasma sources often used in applications of cold atmospheric plasmas. Atmospheric pressure plasma jets provide plasmas that are not spatially bound to any electrode. Typically a plasma is generated internally and then convected to an ambient environment via a gas flow. In this work we outline preliminary models for mass ...
S. Grubinskas, and G. Raciukaitis
Center for Physical Sciences and Technology
Structure under consideration was a layered medium consisting of various materials depending on the specific solar cell. Three processes are considered: energy coupling by electrons taking into account interference effects between the layers, energy transfer from electrons to the lattice using a two-temperature model for heat dissipation and phase transitions in materials. Incident ...