Evolution of the Cross-Sectional Area of the Osseous Lumbar Spinal Canal across Decades: A CT Study with Reference Ranges in a Swiss Population.

Spinal canal dimensions may vary according to ethnicity as reported values differ among studies in European and Chinese populations. Here, we studied the change in the cross-sectional area (CSA) of the osseous lumbar spinal canal measured in subjects from three ethnic groups born 70 years apart and established reference values for our local population. This retrospective study included a total of 1050 subjects born between 1930 and 1999 stratified by birth decade. All subjects underwent lumbar spine computed tomography (CT) as a standardized imaging procedure following trauma. Three independent observers measured the CSA of the osseous lumbar spinal canal at the L2 and L4 pedicle levels. Lumbar spine CSA was smaller at both L2 and L4 in subjects born in later generations (p < 0.001; p = 0.001). This difference reached significance for patients born three to five decades apart. This was also true within two of the three ethnic subgroups. Patient height was very weakly correlated with the CSA at both L2 and L4 (r = 0.109, p = 0.005; r = 0.116, p = 0.002). The interobserver reliability of the measurements was good. This study confirms the decrease of osseous lumbar spinal canal dimensions across decades in our local population

Numerical Modeling of Induction-Heating of Long Workpieces

We consider in this paper an induction heating process. A mathematical model is presented, together with numerical methods used in order to describe the magnetic field, as well as the temperature field evolution. Experimental measurements were performed in order to validate the numerical simulation results. A comparison is presented for both ferromagnetic and non-ferromagnetic materials. An error discussion is provided

Numerical modeling in induction heating for axisymmetric geometries

This paper deals with numerical simulation of induction heating for axisymmetric geometries. A mathematical model is presented, together with a numerical scheme based on the Finite Element Method. A numerical simulation code was implemented using the model presented in this paper. A comparison between results given by the code and experimental measurements is provided

Numerical modelling of induction heating of long workpieces

International audienceWe consider in this paper an induction heatingprocess. A mathematical model is presented, together with numericalmethods used in order to describe the magnetic field,as well as the temperature field evolution. Experimental measurementswere performed in order to validate the numericalsimulation results. A comparison is presented for both ferromagneticand non-ferromagnetic materials. An error discussionis provided