Glass Transition Temperature Depression at the Percolation Threshold in Carbon Nanotube-Epoxy Resin and Polypyrrole-Epoxy Resin Composites

The glass transition temperatures of conducting composites, obtained by blending carbon nanotubes (CNTs) or polypyrrole (PPy) particles with epoxy resin, were investigated by using both differential scanning calorimetry (DSC) and dynamical mechanical thermal analysis (DMTA). For both composites, dc and ac conductivity measurements revealed an electrical percolation threshold at which the glass transition temperature and mechanical modulus of the composites pass through a minimum

Profils motivationnels à l’entrée en Faculté ou en IUT et réussite académique des étudiants

Cette étude vise à identifier les caractéristiques motivationnelles (théorie de l’autodétermination, Ryan & Deci, 2000) des étudiants à l’entrée en 1re année universitaire, selon deux contextes de formation (Faculté des Sciences et Institut Universitaire Technologique) et le lien avec la réussite académique. Trois profils motivationnels sont identifiés dont deux autonomes et contrôlés et un troisième dit amotivé qui se distribuent différemment selon les structures d’accueil. On observe également que la réussite en première année est associée à des sous-modalités distinctes de la motivation selon les structures. Ces résultats conduisent à une réflexion en terme de leviers motivationnels différenciés mais aussi en terme de projet de formation de l’étudiant et de transition lycée-université.This study aims to identify the motivational characteristics (theory of self-determination, Ryan & Deci, 2000) of students entering the first year of university, according to two training contexts (Faculty of Sciences and University Technological Institute) and the link with academic success. Three motivational profiles are identified, two of them are autonomous and controlled, and a third called amotivated. They are distributed differently according to the training structures. It is also observed that success at the first year is associated with distinct sub-modalities of motivation according to the structures. These results lead to some discussion in terms of differentiated motivational triggers but also in terms of student project and on the transition from high school to university

Eruptive history of the Karoo lava flows and their impact on early Jurassic environmental change:

This paper reports new paleomagnetic and geochronologic data from a ~1500 m thick composite section belonging to the Drakensberg group, the thickest remnant of the Karoo lavas in Northern Lesotho. Flow‐by‐flow analysis of paleomagnetic directions reveals 21 magnetic directional groups, corresponding to single eruptive events, and 16 individual lava flows. The new age determinations of lava flows range from 180.1 ± 1.4 to 182.8 ± 2.6 Ma. These data, combined with previous results, allow us to propose that the main part of the Drakensberg group and the Karoo intrusive complex dated around 181–183 Ma may have been erupted over a period as short as 250 kyr and may have coincided with the two main phases of extinction in the Early Toarcian. This scenario agrees well with the discontinuous rhythm of environmental and biotic perturbations in the Late Pliensbachian‐Toarcian interval

Le « monème autonome » : réalité ou fiction ?

Cassignol Jean. Le « monème autonome » : réalité ou fiction ?. In: L'Information Grammaticale, N. 11, 1981. pp. 19-21

Quelques recherches sur la méthode Potassium-Argon.

International audienc

À propos de la réédition (1980) des Éléments de linguistique générale d'André Martinet

Cassignol Jean. À propos de la réédition (1980) des Éléments de linguistique générale d'André Martinet. In: L'Information Grammaticale, N. 14, 1982. pp. 42-43