Search results for "Physique"

The construction of inequalities between girls and boys of success in physical education at the baccalaureate between girls and boys

2004

This research investigates the effect of social and school processes on explanation of the achievement's differences between girls and boys in PE, particularly when they are assessed in team sports in secondary education. The performances of girls often are lower than those of boys. Traditionally, the differentiated performances may be attributed to physiological or sociological reasons. The object of this research, conducted about 1245 pupils and theirs PE teachers, was to focus on a possible differential treatment at school between girls and boys. Teacher's perceptions about sport as a male domain influence the process in which girls receive at school a poorest learning. The relative fail…

Tight-binding study of the optical properties of GaN/AlN polar and nonpolar quantum wells

2009

The electronic structure of wurtzite semiconductor superlattices (SLs) and quantum wells (QWs) is calculated by using the empirical tight-binding method. The basis used consists of four orbitals per atom (sp3 model), and the calculations include the spin-orbit coupling as well as the strain and electric polarization effects. We focus our study on GaN/AlN QWs wells grown both in polar (C) and nonpolar (A) directions. The band structure, wave functions and optical absorption spectrum are obtained and compared for both cases.

La mixité dans l'enseignement des sports de combat : un faux problème ? Deux études de cas en didactique clinique

2018

International audience; À partir du cadre théorique de la didactique clinique et de ses concepts, nous analysons les séances et les entretiens de deux professeur·es d'EPS (Catherine et Daniel) qui enseignent les activités de combat pour répondre aux deux questions: comment la mixité est-elle prise en compte dans l'enseignement des sports de combat? En quoi l'histoire du sujet détermine-t-elle son traitement de la mixité? Les résultats mettent en évidence le fait que ce n'est pas forcément la mixité qui pose des problèmes d'enseignement mais plutôt le rapport au corps des élèves. Chaque enseignant·e déploie des stratégies didactiques pour traiter au mieux ce problème de la relation au corps …

Characteristics of the diffuse astrophysical electron and Tau neutrino flux with six years of IceCube high energy cascade data

2020

We report on the first measurement of the astrophysical neutrino flux using particle showers (cascades) in IceCube data from 2010-2015. Assuming standard oscillations, the astrophysical neutrinos in this dedicated cascade sample are dominated (∼90%) by electron and tau flavors. The flux, observed in the sensitive energy range from 16 TeV to 2.6 PeV, is consistent with a single power-law model as expected from Fermi-type acceleration of high energy particles at astrophysical sources. We find the flux spectral index to be γ=2.53±0.07 and a flux normalization for each neutrino flavor of φastro=1.66-0.27+0.25 at E0=100 TeV, in agreement with IceCube's complementary muon neutrino results and wit…

Variations in fundamental constants at the cosmic dawn

2020

The observation of space-time variations in fundamental constants would provide strong evidence for the existence of new light degrees of freedom in the theory of Nature. Robustly constraining such scenarios requires exploiting observations that span different scales and probe the state of the Universe at different epochs. In the context of cosmology, both the cosmic microwave background and the Lyman-α forest have proven to be powerful tools capable of constraining variations in electromagnetism, however at the moment there do not exist cosmological probes capable of bridging the gap between recombination and reionization. In the near future, radio telescopes will attempt to measure the 21…

Removing krypton from xenon by cryogenic distillation to the ppq level

2017

The XENON1T experiment aims for the direct detection of dark matter in a detector filled with 3.3 tons of liquid xenon. In order to achieve the desired sensitivity, the background induced by radioactive decays inside the detector has to be sufficiently low. One major contributor is the β-emitter 85Kr which is present in the xenon. For XENON1T a concentration of natural krypton in xenon natKr/Xe<200ppq (parts per quadrillion, 1ppq=10-15mol/mol) is required. In this work, the design, construction and test of a novel cryogenic distillation column using the common McCabe–Thiele approach is described. The system demonstrated a krypton reduction factor of 6.4 · 10 5 with thermodynamic stability a…

Crémation et archéologie : Nouvelles alternatives méthodologiques en ostéologie humaine

2014

Hard-sphere fluids in annular wedges: density distributions and depletion potentials.

2009

We analyze the density distribution and the adsorption of solvent hard spheres in an annular slit formed by two large solute spheres or a large solute and a wall at close distances by means of fundamental measure density functional theory, anisotropic integral equations and simulations. We find that the main features of the density distribution in the slit are described by an effective, two--dimensional system of disks in the vicinity of a central obstacle. For large solute--solvent size ratios, the resulting depletion force has a straightforward geometrical interpretation which gives a precise "colloidal" limit for the depletion interaction. For intermediate size ratios 5...10 and high sol…

Analyse didactique clinique des pratiques d'enseignement et de formation: Les effets du déjà-là expérientiel sportif

2016

Cette note de synthèse s'inscrit dans la suite de mes travaux sur les filtres de l'action didactique qui questionnent le " déjà-là " des sujets. Dans le " déjà-là expérientiel ", je m'intéresse ici aux expériences corporelles importantes des sportifs et plus particulièrement à celles vécues par les professeurs d'EPS. M'appuyant à la fois sur les trois temps de la didactique clinique (le déjà-là, l'épreuve et l'après-coup) et sur une introspection, je montre combien ces expériences sportives liées à la spécialité chez les enseignants d'EPS, expériences souvent traduites en épreuves, laissent des traces profondes qui viennent structurer le rapport au corps, le rapport à soi et aux autres de c…

Enseigner la touche en boxe anglaise : une question de sécurité didactique

2021

International audience