Grégory Munoz

If research works, inspired by the instrumental approach of Rabardel (1995), shone the activities instrumented by the teachers by spotting instrumental geneses (Saujat, 2000), on the other hand, none tried to consider their systems of instruments (Bourmaud, 2006). Inspired by an investigation realized in the branch of industry, we discuss the opportunity of such analysis for the training of the teachers. From a case study based on interviews investigating the redefined task (Leplat, 1997) of professionals in charge of safety in company, we determine the five characteristics of a system of instruments for one of the professionals became trainer. Si des travaux de recherche, inspirés de l'approche instrumentale de Rabardel (1995), ont éclairé les activités instrumentées des enseignants en repérant des genèses instrumentales (Saujat, 2000), en revanche aucun n’a cherché à considérer leurs systèmes d'instruments (Bourmaud, 2006). Inspirés par une investigation réalisée dans le secteur industriel, nous discutons de l'opportunité d’une telle analyse pour la formation des enseignants. A partir d’une étude de cas appuyée sur des d’entretiens explorant la tâche redéfinie (Leplat, 1997) de professionnels chargés de sécurité en entreprise, nous déterminons les cinq caractéristiques d’un système d’instruments chez un des professionnels devenu formateur.

We examine the possible role played by field angular momentum in two systems of vastly different sizes: (i) the nucleon and (ii) highly magnetic white dwarf stars. For the nucleon we study the restrictions on the nucleon's structure that arise from the requirement that the total field angular (spin, orbital and field angular momentum) should satisfy the standard angular momentum commutation relationship. For the magnetic white dwarfs we argue that the magnetic field may alter the statistics of some fraction of the white dwarf's electrons from fermionic to bosonic. This would effect the stars structure, giving it a smaller than expected radius, and a lower than expected temperature. In some extreme cases one could imagine that this effect could lead to the collapse of the white dwarf into a neutron star despite being below the Chandreshekar limit