The Effectiveness of Hooks for Plain Steel Reinforcement

As buildings age, their structural integrity must be assessed and reassessed at regular intervals to ensure the safety of their continued use and to advise on retrofits and repairs necessary for preventative maintenance and responsive repair. Historic buildings often contain plain reinforcement whereas modern buildings exclusively contain modern deformed reinforcement. Younger engineers in particular have not been trained with or worked with plain bar. Modern American Concrete Institute (ACI) and Canadian Standards Association (CSA) Group codes largely do not contain adequate provisions to assess the structural integrity of many historic buildings. Twenty-four beam-column joint specimens with four different hook configurations were tested under tension to compare the anchorage capacities of embedded plain and modern deformed 90° and 180° hooked bars. Six replicates of each configuration were tested to determine whether statistically significant differences at the 95% confidence level existed between the anchorage capacities of plain versus modern deformed hooked bars. Visual observations were documented manually to assess differences between crack patterns and observed failure modes. Typical cracking patterns were observed for groups of both specimens containing 90° and 180° hooks. The degree of cracking observed aligned with results of similar studies. All specimens with 90° hooks failed by side blowout whereas those with 180° hooks failed by front blowout. No evidence of group effects (i.e. decreased anchorage capacity) was observed. Statistically significant differences in maximum normalized tensile load at the 95% confidence level were observed between 90° plain and modern deformed bars, wherein the plain bars had a 3.8 kN/MPa lower maximum; 180° plain and modern deformed bars, wherein the plain bars had a 5.6 kN/MPa lower maximum; and 90° and 180° modern deformed hooked bars, wherein the 90° bars had a 4.0 kN/MPa lower maximum. No statistically significant differences in displacement at maximum normalized load were observed. An extensive replicate-based study of plain hooked bar incorporating additional parameters (e.g. lead length, bend angle, etc.) is recommended. The value of the recommended work is in determining the sensitivity of hooked bar performance to variations in these parameters

Enseigner les techniques sportives dans une classe d'Éducation physique en Réseau ambition réussite : une activité " située ", émergente et socialement construite

International audienceThis study in "situated action" analyzes the activity of the pupils, the teacher and the way they are linked in the context of difficult classes in RAR (Réseau Ambition Réussite). It aims at understanding what "appears in act" during physical education lessons in this specific context of RAR and in particular what can explain the difficulties the teacher can have in transmitting sports techniques.Cette étude en anthropologie cognitive située analyse l'activité des élèves, de l'enseignant et leur articulation dans le cadre de classes difficiles en RAR (Réseau ambition réussite). Elle vise à comprendre ce qui " fait l'actualité " de l'Éducation Physique et Sportive (EPS) dans le contexte particulier des RAR et notamment ce qui peut expliquer les difficultés de l'enseignant à transmettre des techniques corporelles et sportives

Mettre une classe au travail en Réseau Ambition Réussite : des formes typiques d'interaction enseignant-élèves lors de leçons d'EPS

International audienceThis study carried out in an "Ambition Réussite" secondary school, aims at understanding how experienced physical education teachers manage in a lasting way, to set a class to work, during a lesson, with pupils who are not prone to engage in a study activity. It analyses: a) the teacher's actions in order to construct a collective activity of viable work, b) of the significances which he allots to the pupils' engagement in work during the lesson, c) in order to identify the typical forms of interaction teacher-pupils which underlie this collective activity of work. It is led on the anthropology framework, under the ideal and methodological model of the "Course of action" (Theureau, 1992/2004). It rests on ethnographic materials and verbalizations during post-protocol interviews. The results reveal the existence of typical forms of interaction in the class, relating to: a) the interactions' management of space b) focusing on prescriptive work, c) a tolerance to ludic transgressions d) a perception of the limit threshold of deviance.Cette étude effectuée dans un collège " Ambition réussite " vise à comprendre comment des enseignants d'EPS expérimentés parviennent de façon durable à mettre une classe au travail au cours d'une leçon avec des élèves peu enclins à s'engager dans une activité d'étude. Elle vise à rendre compte : a) des actions de l'enseignant pour construire une activité collective de travail viable, b) des significations qu'il attribue à l'engagement des élèves dans le travail au cours de leçon, c) des formes typiques d'interaction enseignant-élèves qui sous-tendent cette activité collective de travail. Elle est conduite dans le cadre de l'anthropologie, sous le modèle théorique et méthodologique du " Cours d'action " (Theureau, 1992/2004). Elle s'appuie sur des matériaux ethnographiques et des verbatim d'entretiens d'autoconfrontation. Les résultats révèlent l'existence de formes typiques d'interaction dans la classe, relatives : a) à la gestion spatiale des interactions, b) à la focalisation sur le travail à effectuer, c) à une tolérance aux transgressions ludiques, d) à une perception de seuils-limites de déviance

MOEMS deformable mirror testing in cryo for future optical instrumentation

MOEMS Deformable Mirrors (DM) are key components for next generation instruments with innovative adaptive optics systems, in existing telescopes and in the future ELTs. These DMs must perform at room temperature as well as in cryogenic and vacuum environment. Ideally, the MOEMS-DMs must be designed to operate in such environment. We present some major rules for designing / operating DMs in cryo and vacuum. We chose to use interferometry for the full characterization of these devices, including surface quality measurement in static and dynamical modes, at ambient and in vacuum/cryo. Thanks to our previous set-up developments, we placed a compact cryo-vacuum chamber designed for reaching 10-6 mbar and 160K, in front of our custom Michelson interferometer, able to measure performances of the DM at actuator/segment level as well as whole mirror level, with a lateral resolution of 2{\mu}m and a sub-nanometric z-resolution. Using this interferometric bench, we tested the Iris AO PTT111 DM: this unique and robust design uses an array of single crystalline silicon hexagonal mirrors with a pitch of 606{\mu}m, able to move in tip, tilt and piston with strokes from 5 to 7{\mu}m, and tilt angle in the range of +/-5mrad. They exhibit typically an open-loop flat surface figure as good as <20nm rms. A specific mount including electronic and opto-mechanical interfaces has been designed for fitting in the test chamber. Segment deformation, mirror shaping, open-loop operation are tested at room and cryo temperature and results are compared. The device could be operated successfully at 160K. An additional, mainly focus-like, 500 nm deformation is measured at 160K; we were able to recover the best flat in cryo by correcting the focus and local tip-tilts on some segments. Tests on DM with different mirror thicknesses (25{\mu}m and 50{\mu}m) and different coatings (silver and gold) are currently under way.Comment: 11 pages, 12 Figure

A New Record Size Wolf, Canis lupus, Group for Ontario

This report documents a group of 19 Wolves (Canis lupus) in northwestern Ontario. This is the largest group observed since record keeping in the Moose Aerial Inventory commenced in 1995. This large group may be a response to a high Moose (Alces alces) population in the Red Lake area

Complex links between dietary lipids, endogenous endotoxins and metabolic inflammation.

International audienceMetabolic diseases such as obesity are characterized by a subclinical inflammatory state that contributes to the development of insulin resistance and atherosclerosis. Recent reports also indicate that (i) there are alterations of the intestinal microbiota in metabolic diseases and (ii) absorption of endogenous endotoxins (namely lipopolysaccharides, LPS) can occur, particularly during the digestion of lipids. The aim of the present review is to highlight recently gained knowledge regarding the links between high fat diets, lipid digestion, intestinal microbiota and metabolic endotoxemia & inflammation

La dynamique du décrochage local des élèves en classe structurée par un faisceau de préoccupations « travail – jeu »

Cette recherche considère le décrochage comme un processus, issu d’un parcours personnel et ayant sa propre dynamique trouvant ses origines à l’intérieur de la classe par des comportements non conformes au travail scolaire. L’objet de notre étude est de comprendre la dynamique du décrochage local, situé, en analysant l’activité des élèves en cours d’éducation physique et sportive (EPS) dans des établissements appartenant à la politique d’éducation prioritaire. Le cadre théorique et méthodologique mobilisé est celui du ‘cours d’action’ (Theureau, 2006). Le décrochage local du travail scolaire est analysé au regard de l’engagement des élèves dans la leçon en fonction de leurs bifurcations de préoccupations. Onze élèves de 6ème et 5ème ont participé à cette étude dans un dispositif de gymnastique par ateliers. Le recueil de matériaux s’est fait à partir d’enregistrements audiovisuels et d’entretiens d’autoconfrontation. Leur traitement a visé à rendre compte de l’activité des élèves et en particulier leurs préoccupations, perceptions et connaissances mobilisées dans l’action. Les résultats montrent que l’activité des élèves est organisée par un faisceau de préoccupations « travail – jeu » comprenant une dynamique propre alternant des phases de décrochage et de raccrochage au travail scolaire.This research considers the dropout as a process, from a personal course and having its own dynamics finding its origins within the classroom by misbehavior. The purpose of our study is to understand the dynamics of local drop-out by analyzing the activity of students during physical education class in middle schools belonging to the compensatory policy. The theoretical and methodological framework used is the “course of action” (Theureau, 2006). The local dropout of school work is analyzed in terms of student engagement in the lesson according to their concerns bifurcations. Eleven students from 6th and 5th in middle schools were studied in a gymnastics workshops. The collection of data is made from video recordings and interviews of self-confrontation. Data processing aimed to analyze the activity of the students and in particular their concerns, perceptions and knowledge used in action. The results show that the activity of the students is organized by two concerns “work - play” including its own dynamic alternating phases of drop-out and of hang up the school work

Éditorial

Ce troisième numéro spécial de la revue eJRIEPS est consacré aux actes de la 11ème Biennale de l’Association pour la recherche sur l’intervention en sport qui s’est tenue à Lille du 19-21 juin 2018. Le colloque intitulé « L'intervention dans les pratiques physiques, sportives et artistiques : Responsabilités et Stratégies des acteurs » s’est centré sur l’analyse de l’intervention en sport et en éducation physique. Les activités physiques, sportives, et artistiques apparaissent souvent comme u..

How can video feedback be used in physical education to support novice learning in gymnastics? Effects on motor learning, self-assessment and motivation

Background: Much of the existing research concerning the use of video feedback (VFB) to enhance motor learning has been undertaken under strictly controlled experimental conditions. Few studies have sought to explore the impact of VFB on the skill learning experience of the students in a structured, school-based physical education (PE) setting. Most of those studies have only used qualitative approaches to implicate the potential value of VFB to enhance skill acquisition, students ’ engagement or self- assessment ability. Using a quantitative approach, the aim of this study was to investigate effects of using VFB on motor skill acquisition, self- assessment ability and motivation in a school-based learning environment (structured PE programme) with novice children learning a gymnastic skill. Method: Two French classes of beginners took part in a typical five-week learning programme in gymnastics. During each of the five, weekly lessons participants carried out the same warm-up routine and exercises. The experimental group (10 girls – 8 boys, 12.4 ± 0.5 years) received VFB intermittently when learning a front handstand to flat back landing. VFB was given after every five attempts, combined with self-assessment and verbal instructions from the teacher. The control group (12 girls – 13 boys, 12.6 ± 0.4 years) received exactly the same training but was not given VFB. In order to assess progress in motor skills, the arm-trunk angle (hand- shoulder-hip) was measured in the sagittal plane just as the hips formed a vertical line with the shoulders. Motivation was assessed using the Situational Motivation Scale questionnaire (Guay, F., R. J. Vallerand, and C. Blanchard. 2000. “ On the Assessment of Situational Intrinsic and Extrinsic Motivation: The Situational Motivation Scale (SIMS). ” Motivation and Emotion 24 (3): 175 – 213), and self-assessment ability was measured by self-perception task scores. Results: Statistical analysis of arm-trunk angle values showed significant differences only for the VFB group between the fifth lesson and all other lessons. Between lessons 4 and 5, the arm-trunk angle value increased significantly from 146.6 ± 16.9 degrees to 161.2 ± 14.2 degrees ( p < .001; ES = 0.94). Self-assessment scores improved significantly for the VFB group between lesson 1 and lesson 2 ( p < 0.01, ES = 1.79) and between lesson 4 to lesson 5 ( p < .01, ES = 0.94). Amotivation decreased significantly for the VFB group between lesson 1 and lesson 5 (3.06 ± 1.42 vs. 2.12 ± 0.62, p < .001, ES = − 0.89). Discussion/conclusion: Our quantitative data, identifying key movement changes as a function of experience in a structured PE programme, were congruent with outcomes of previous qualitative research supporting the role of VFB. This study highlights the potential relevance of using VFB in fostering motor learning, motivation and self-assessment during a PE programme with young children. Future pedagogical research is needed to examine the ways students could use VFB technology for greater self- regulation, with the potential to deliver appropriate movement feedback, based on different levels of experience in students