Articles techniques et présentations

The use of foundation piles as ground heat exchangers coupled to a geothermal heat pump is considered of interest for possible savings in installation costs, compared to conventional borehole heat exchangers. We refer to them as “geothermal piles” or “energy piles”. The main purpose of ... En savoir plus

Vibrations are an essential part of our day to day engineering environment, which happen in automobiles, avionics, machines, electric motors, structures, electronic equipments, etc. When a system is vibrating under higher frequencies leads to higher displacement, noise and heat ... En savoir plus

In this study, a model of in-situ geothermal energy piles was constructed using COMSOL Multiphysics® software. Geothermal energy piles serve two purposes, first to transfer building load into the subsurface, but also to extract thermal heat from surrounding soils. This is achieved using ... En savoir plus

As an effective method to cope with green-house gas emission, and to enhance oil recovery, injection of carbon dioxide into oil reservoirs has obtained increasing attentions. The flooding process involves complex phase behavior among oil, brine and CO2, and geochemical reaction between ... En savoir plus

Various research activities are happening around the world on harvesting energy from green energy sources to satisfy the power requirements. Being an abundant form of green energy acoustic energy harvesting has been gaining importance despite the low power density of its sources. In ... En savoir plus

Alexander Frey received his M.A. degree from the University of Texas, Austin, in 1994, the Dipl. Phys. degree from the University of Wuerzburg, Germany in 1997 and the PhD from the Saarland University, Germany in 2010. In 1997 he joined Research Laboratories of Siemens working on the ... En savoir plus

On the surface of an optical waveguide, there is an evanescent field. The evanescent field decays fast and this steep gradient can be used to pull nano- and microparticles down towards the waveguide surface. Radiation forces will propel the particle forward along the waveguide. Trapping ... En savoir plus

This report mainly discusses the implementation and results of a project proposal, “Modelling using Finite Element Methods”. The report is devoted to implementation, which is a model of an electromagnet. The software tool that is used to model the electromagnet is COMSOL Multiphysics®, a ... En savoir plus

Electronic devices produce a very high rate of specific heat with respect to their dimensions. Exceeding in maximum safe operating temperature means strong reduction of efficiency, reliability and lifetime. In addition, electronic devices are subjected to periodical thermal loading. ... En savoir plus

Analytical methods used for inductance calculation of toroidal coils yield large errors in the case of coils sparsely wound on low permeability cores. Numerical field calculations can provide “exact” figures. We have outlined several simulation methods. Simplifications, assumptions, and ... En savoir plus