L’évolution du contexte d’enseignement au cours des quarante dernières années invite à repenser la question de la réussite universitaire. Les métamorphoses de la population étudiante et des systèmes d’organisation des études universitaires ont engendré des difficultés importantes, en particulier sur les modalités d’accès au diplôme universitaire et les conditions d’insertion professionnelle des étudiants. Face à ces difficultés, des études, fortement orientées vers l’analyse des échecs et des abadons, se sont emparées de la question étudiante pour tenter de comprendre les mécanismes explicatifs des phénomènes constatés dans les universités. Notre approche rompt avec cette tradition sociologique mettant l’accent sur les défaillances, les défauts, les manques d’une population. Elle analyse les conditions de réussite des étudiants inscrits au sein de l’UFR SESS-STAPS de l’UPEC. Cette enquête porte sur l’étude des trajectoires des étudiants afin de mieux isoler les facteurs explicatifs de leur réussite. Ceux qui réussissent sont-ils tellement différents de ceux qui échouent ou quittent l’université ?Les éléments de définition de la réussite adoptés dans cette thèse ainsi que les données recueillies permettent de comprendre que les études universitaires sont loin d’être jouées à l’avance, il est possible de constater des réussites importantes de certains étudiants donnés perdants dès l’entrée à l’université. Notre investigation méthodologique appréhende ces différents mécanismes en oeuvre dans le parcours universitaire des étudiants en licence. / The changing educational environment that has occurred over the last four decades invites us to rethink the issue of academic achievement. The metamorphoses of student population and organisational systems of university studies have caused important difficulties, especially on the access to university diploma and on students’ professional integration conditions. Given these difficulties, research, greatly oriented to the analysis of failures and student dropouts, has focused on the student issue in order to try to understand the explanatory mechanisms of phenomena observed in universities. Our approach breaks with this sociological tradition by highlighting the weaknesses, flaws and lacks of a population. It analyses conditions for success concerning students registered in SESS-STAPS UFR at UPEC University. This research focuses on the analysis of students’ path so as to isolate in a better way the explanatory factors of their success. Those who succeed are they really different from those who fail or quit university ?The elements of definition for success in this thesis and the collected data enable us to understand that university studies are far from being a foregone conclusion. It is possible to determine important successes of some students given to be underdogs from the start of the academic year. Our methodological investigation apprehends these different mechanisms working within academic careers of bachelor students.

The purpose of this study was to identify whether three achievement motivation variables (LGO, GNS, and AO) were positively related to work-family balance, and to investigate plausible interactions between these variables and work-family stressors on balance perceptions. Relationships of these variables to work-family conflict and facilitation outcomes were also analyzed in order to identify differential relationships. Data were collected from 428 individuals through a web-based survey. Results indicated that all three achievement motivation variables were clearly related favorably to work-family balance and facilitation, while only AO was negatively related to conflict. The relationships between schedule flexibility and all work-family outcomes were moderated by both LGO and GNS. The majority of proposed interactive effects between achievement motivation variables and work-family stressors on balance were not significant. However, several interactions were significant when conflict or facilitation served as the criterion measure. Overall, the results provide support for LGO, GNS, and AO as both direct and indirect contributors to work-family balance.

Non communiqué / Non communiqué

La FA (Fabrication Additive) est un procédé de fabrication qui rend possible, en ajoutant de la matière couche après couche, la création de pièces en trois dimensions. Cette technologie a de nombreux intérêts car elle permet l’intégration de formes ou de structures complexes, la réduction des déchets, la fabrication sur demande et la réduction du temps de conception. Au cours de cette thèse, nous avons cherché à déterminer des orientations remarquables de pièces afin de les fabriquer par des procédés de FA. Au vu du grand nombre d’effets liés à l’orientation d’une pièce, nous avons choisi une approche multicritères prenant en compte la qualité de surface des pièces, le volume de support, le temps et le coût de fabrication. Afin d’avoir une bonne qualité de surface sur les faces fonctionnelles de la pièce et pour limiter le post-traitement, une orientation précise a été définie pour chacune d’elle. Cette méthodologie a été développée dans le cadre du projet Taal, projet de recherche et développement précurseur du logiciel 4D-Additive de Coretechnologie. Sur ce dernier, en plus de cette méthodologie, de nombreuses fonctions ont été développées pour préparer la fabrication d’une pièce par un procédé additif. L’orientation d’une pièce en FA est une étape à ne surtout pas négliger. Elle pourra permettre de trouver un compromis entre les spécificités liées aux procédés de FA ou entrainer un coût important de fabrication et une qualité de surface de la pièce médiocre. Des évolutions de la méthode sont possibles comme une étude mécanique de la pièce dans les différentes orientations testées car de nombreuses questions se posent sur la résistance des pièces imprimées. / AM (Additive Manufacturing) is a manufacturing process that makes possible, by adding layer-by-layer material, to create three-dimensional parts. This technology has many interests as it allows complex shapes or structures integration, waste reduction, on-demand fabrication and reduced conception time. During this thesis, we tried to determine remarkable orientations of parts in order to manufacture them by AM process. Considering the large number of effects related to part orientation, we chose a multi-criteria approach taking into account the surface quality of the parts, the volume of support, the manufacturing time and cost. In order to have a good surface quality on functional faces of the part and to limit the post-treatment, a precise orientation has been defined. This methodology was developed in the structure of the Taal project, a research and development project precursor of Coretechnologie's 4D-Additive software. On this last, in addition to this methodology, many functions have been developed to prepare the manufacture of a part by an additive process. The orientation of a part in AM is a step that can’t be overlooked. It may make it possible to find a compromise between the specificities related to the AM processes or generate a high manufacturing cost and a poor surface quality of the part. Evolutions of the method are possible as a mechanical study of the part in the different orientations tested because many questions arise on the strength of the printed parts.

In South Africa, there are various stakeholders involved in career guidance services (Stead & Watson, 2006, P.160). The teaching of career guidance within the context of Life Orientation (LO) at schools is the responsibility of Life Orientation teachers. This study explores the experiences of Life Orientation teachers in teaching career guidance in rural high schools at Lephalale Municipality. The study used qualitative approach to obtain rich information about the experiences of Life Orientation teachers in teaching career guidance at rural high schools. The study was conducted in two rural high schools in the Palala North Circuit of Lephalale Municipality. The sample comprised of two Further Education and Training (FET) Phase Life Orientation teachers from two rural high schools (one from each school). The participants were purposefully and conveniently selected. The data was collected by means of the semi-structured interviews. The data was analysed using the inductive thematic data analysis where themes, subthemes and categories emerged. The findings of the study reflected both the negative and positive experiences of Life Orientation teachers in respect of their teaching of careers and career choices, training and support needs, and the career- related activities such as career exhibitions in which both the learners and LO teachers participate. The results of the study will be shared with the two schools in the Palala North Circuit and the Department of Education, Waterberg District in the Limpopo province. It is hoped that the results generated by the study might assist the training personnel or facilitators (education or subject specialists) to know the type of training and support that LO teachers require and to also inform policy makers to develop a model of teaching career guidance at rural high schools. / Dissertation (MEd)--University of Pretoria, 2017. / Educational Psychology / MEd / Unrestricted

Dans cette thèse, un composite unidirectionnel à renfort lin (composite UD biosourcé) a été développé et élaboré par la technique de presse à chaud. Le comportement en traction des composites à renfort végétal montre en général deux domaines, mais un troisième domaine est identifié dans ce travail. Un modèle phénoménologique développé précédemment pour décrire le comportement en traction d'un composite à renfort en fils torsadés a été testé avec le composite UD biosourcé. Nous montrons que l'ajout d'un phénomène de consolidation au modèle précédent est nécessaire pour simuler correctement le troisième domaine. Un second modèle mécanique a été par ailleurs développé pour identifier expérimentalement les propriétés mécaniques effectives du renfort en lin lorsqu'il est piégé dans la matrice. La distribution statistique de l'orientation locale du renfort a été mesurée pour pouvoir prendre en compte l'orientation des fibres. Pour cela, la technique du tenseur de structure a été appliquée sur des images optiques du pli de lin. Par ailleurs, ce modèle permet d'étudier l'influence des porosités sur les propriétés mécaniques. Les deux modèles permettent d'effectuer des prévisions efficaces du comportement mécanique du composite de fibre de lin unidirectionnel. En complément des modèles de mécanique, le comportement en sorption du composite de lin UD a également été analysé. Le modèle de Langmuir et le modèle de Fick ont été appliqués sur nos composites UD. Les résultats montrent que la configuration unidirectionnelle du renfort de lin favorise la sorption d'eau des composites associés.Résumé en anglais / In this Ph.D work, unidirectional flax fiber composite (UD biobased composite) has been designed and manufactured based on the hot platen press process. Plant fiber composites usually exhibit two regions under tensile load, but three regions have been identified in this work. A phenomenological model, previously developed to describe the tensile mechanical behavior of twisted plant yarn composites, has been tested with the UD biobased composite. We show that the addition of a strengthening phenomenon to the previous model is necessary to simulate correctly the third region. A second mechanical model has also been developed for experimental identification of the effective mechanical properties of flax reinforcement when embeded in matrix. A statistical distribution of local orientation of UD reinforcement was obtained allowing taking the fiber orientation into account. To that end, structure tensor method was applied to optical images of flax ply. Furthermore, this model allows the effect of porosity on mechanical properties to be studied. Both models provide effective forecast of the mechanical behavior of unidirectional flax fiber composite. Besides the mechanic models, sorption behavior of UD flax composite also has been analyzed. Langmuir's model and Fick's model were applied on our UD composite. The results show that the unidirectional configuration of the flax reinforcement promotes the water sorption from the associated composites.

The objective of this study is to investigate the strategic factors that influence the overall performance of manufacturing organisations in different industries. Strategic groups were identified using cluster analysis and their overall performance was evaluated. Structural equation modelling was used to verify the existence of significant linkages between competitive factors and firms' overall performance within the identified strategic groups. The results of this study pointed out to the existence of a relationship between strategic group membership and firm's overall performance. Overall, the results tend to emphasise the importance of viewing manufacturing performance from a system-wide perspective.

Competency-based nurse orientation programs focus on the new nursing graduate and experienced nurse employees' ability to perform skills necessary in a new work setting. The purpose of this project was to develop a learner-focused and competency-based orientation program for new nursing employees at a large urban hospital to enhance patient safety and nurse retention. The Johns Hopkins nursing evidence-based practice model and guideline were used in the selection of articles with higher levels of evidence and research quality for the critical appraisal of literature in support of the program development. The best practices for nursing orientation content and delivery for positive effects on hospital finances, nurse turnover rates, and patient safety were the focus of the literature review. Benner's model of 5 levels of skill development was the theoretical framework for advancing skills of nurses who enter the orientation program with different expertise and skill sets. Nurse orientation materials and processes, comprising a collaborative team approach to orientation and a guideline for preceptor selection, were developed as the essential components for successful orientation at the project hospital. A nursing orientation based on the evidence may provide an infrastructure and operational process for the organization in developing the competencies of all levels of nurses, including experienced nurses transitioning to new units or duties. The social change resulting from the project will be a supportive and seamless transition of nurses into the new practice role and work environment. When implemented, this project is anticipated to increase nurse satisfaction, improve quality of health care delivery, decrease anxiety related to the new nursing role, and improve collegiality among all levels of nurses.

This qualitative case study examined the lack of success by and high attrition rates of adult learners enrolled in online higher education courses at a public research university in the southeastern United States. The conceptual framework integrated Knowles' theory of andragogy with a composited model that combined elements of Tinto's persistence model with Bean and Metzner's student attrition model. The research questions examined factors and characteristics contributing to the unsuccessful completion of online courses for adult learners. The data were collected in 2 separate phases using a purposeful sample comprised of 152 adult learners who volunteered to participate in the study and had enrolled in an online course at the university between the fall 2013 and spring 2015. The findings revealed that factors such as work-related issues, lack of time management, and personal issues contributed to students' unsuccessful completion of online courses. Additionally, the participants' success depended on their strengths and weaknesses with time management skills, motivation and dedication, technological skills, and communication skills in online learning. The findings were used to create a pre-orientation workshop designed to assist adult learners prior to taking their first online course by assessing student readiness levels for online learning and identifying deficiencies in skills required to be successful. Offering a pre-orientation workshop session to first-time online adult learners will increase their likelihood of success and foster a positive effect on social change in this population by improving retention in an online learning environment.

Les nanoparticules luminescentes sont particulièrement étudiées pour leur application dans les systèmes d’éclairages ou comme sondes en bio-imagerie. Parmi elles, les nanoparticules anisotropes de matrices cristallines dopées par des ions lanthanides présentent une émission polarisée, qui dépend de la symétrie des sites des ions émetteurs. Le lien entre direction de polarisation et axes cristallins des nanocristaux permet de déterminer leur orientation, et peut donc être exploité pour suivre l'orientation d’objets ou pour caractériser la déformation de milieux hôtes.Les objectifs de ce doctorat ont été de s’intéresser aux origines fondamentales de l’émission polarisée de nanobâtonnets de phosphate de lanthane dopés par des ions europium trivalents (LaPO4:Eu) et d’utiliser la luminescence polarisée à des mesures d’orientation.Dans une première partie, les nanobâtonnets de LaPO4:Eu ont été synthétisés puis alignés sous forme des films orientés. La luminescence de ces films a permis de suivre avec précision la transition de phase de la matrice hôte, de sa structure hexagonale à une structure monoclinique ; et de mettre en évidence la présence de défauts structuraux. La polarisation des spectres de luminescence a ensuite été étudiée. Les taux de polarisation mesurés sont plus élevés pour la phase monoclinique que pour la phase hexagonale. La sensibilité du spectre de polarisation au milieu diélectrique qui les entoure a été mise en évidence.La seconde partie de cette étude porte sur l’utilisation de la polarisation des nanobâtonnets de LaPO4:Eu pour déterminer leur orientation. La connaissance des spectres polarisés des films parfaitement alignés a permis de déterminer le paramètre d’ordre d’une suspension de nanobâtonnets désordonnés en écoulement dans un canal microfluidique puis d’estimer le taux de cisaillement de cet écoulement. Notre étude a permis de préciser quantitativement les conditions dans lesquelles l’utilisation de la luminescence polarisée comme sonde locale du taux de cisaillement d’un écoulement est valide. / Luminescent nanoparticles have been studied for their applications in lighting devices or as probes in biology. Among these nanoparticles, the anisotropic crystals doped with lanthanides ions emit linearly polarized light. The relation between the polarized directions and the crystallographic axis of the nanocrystals allow determining their 3D orientation, which could be an asset to track objects or to characterize flows.The purposes of this thesis were to investigate the origin of the polarized light of nanorods of lanthanum phosphate doped with europium ions (LaPO4:Eu) and to apply this polarized light to determine their orientation.First, nanorods of LaPO4:Eu are synthesized and aligned to prepare oriented films. The phase transition of the LaPO4 matrix is investigated, from the hexagonal to the monoclinic structure. The luminescence is used to track precisely the transition and show the presence of structural defects. Then the polarized spectra are observed. The polarization degrees of the monoclinic phase are higher than those of the hexagonal one. The sensitivity of the polarization with the dielectric medium is also shown.Then, the polarized light is used to determine the orientation of the nanorods. The knowledge of the polarized spectra along he nanorods axis and perpendicularly to it is used to calculate the order parameter of disoriented nanorods in a microfluidic channel and then to estimate the shear rate of the flow. Our study allows quantifying the conditions in which the nanorods can be used as probes to measure the local shear rate.