Magister Artium - MA / This study is an investigation of the application of dual-medium and parallel-medium models of bilingual schooling as implemented at two historically disadvantaged primary schools in the Western Cape. The author assumes that parallel-medium in practice uses only one language of learning and teaching (LoLT), and thus lead to monolingual classroom practice. The author used qualitative techniques (observations, interviews, and document analyses.), and triangulation method, to understand the application of dual-medium and parallel-medium instruction and the support of principals and teachers in their understanding of the design models. Observations were made in Grade 7 classrooms at selected and document analyses, triangulated with interviews conducted with principals and teachers to expound the effective practice of bilingual education at school and classroom level. Document analyses were made of classroom materials (various literary artefacts) used for the development of language proficiency. in addition, how it contributes to the Grade 7 learners academic perform and language development in dual-medium and parallel-medium classrooms. / South Africa

A large portion of the world’s population is multilingual. This trend is reflected in the population with communication disorders, and therefore in people with complex communication needs (CCN). People with CCN may need alternative and augmentative communication (AAC) systems to facilitate their participation in daily life. These systems are often related to the language of the person’s community. Yet, if this person lives in a multilingual community, little current research is available to guide the design of AAC systems that give access to expression in more than one language. This pilot study aimed to determine the ability of typically developing Afrikaans-English bilingual children, between the ages of 4;6 (years;months) and 6;11, to label Picture Communication Symbols (PCS) in both these languages when taught with mono medium (English) versus dual medium (Afrikaans and English) teaching. Four participants, who spoke Afrikaans and English, were included in the study. A withinsubjects crossover design was used. Each participant was taught two sets of symbols, one using mono medium and one dual medium teaching. Treatments were counterbalanced for order and set. Results tentatively showed that the teaching method was successful, with participants being able to label most symbols in English when taught in either mono (English) or dual medium. Participants were also able to label symbols in Afrikaans when taught the symbols by dual medium teaching. Some participants were spontaneously able to translate symbols taught by mono medium teaching (English) to Afrikaans. This pilot study tentatively suggests that this ability is dependent on the child’s receptive vocabulary ability in both languages, as well as their ability to express the concepts depicted by the symbols in both L1 and L2. Future research is needed with studies that include a larger sample size, to be able to draw more robust conclusions. / Mini Dissertation (M(AAC))--University of Pretoria, 2017. / National Research Foundation (NRF) / Centre for Augmentative and Alternative Communication (CAAC) / M(AAC) / Unrestricted

Pour effectuer des simulations d'écoulement diphasique dans les réservoirs fracturés, l'usage des modèles DFM entraîne des temps de calculs exorbitants. L'une des solutions envisageables est le recours aux modèles double milieu. Ces modèles nécessitent la détermination des dimensions du bloc équivalent et la mise à l'échelle des paramètres d'écoulement monophasique et diphasique. Concernant les paramètres d'écoulement monophasique, des méthodes de mise à l'échelle existantes ont déjà fait leur preuve. En contrepartie la mise à l'échelle des paramètres d'écoulement diphasique reste un sujet ouvert nécessitant l'identification de la nature des forces (capillaires, gravitaires ou visqueuses) contrôlant l'écoulement dans le réservoir. Dans le cadre de cette thèse, les formulations mathématiques et les modèles numériques liées à la simulation de type DFM et double milieu ont été explorés. Une étude bibliographique portant sur les méthodes existantes de mise à l'échelle a été développée. Une nouvelle méthode de détermination des dimensions du bloc équivalent (méthode OBS) a été mise en place. Une analyse dimensionnelle servant à identifier la nature des échanges matrice-fractures (capillaire ou visqueuses) lors d'un écoulement diphasique eau-huile, sans gravité, a été mise en place. Le nombre capillaire dérivé a été testé. Enfin, une méthodologie de mise l'échelle des paramètres équivalents double milieu a été mise en place. Cette méthodologie traite le cas d'un écoulement diphasique dans les réservoirs fracturés ayant un milieu matriciel hétérogène dans un contexte d'échanges matrice-fractures dominés par les effets visqueux. / In order to carry-out two phase flow simulations within naturally fractured reservoirs, using DFM models results in huge computational costs. Using dual medium models is one of the available alternative solutions. These models require identifying the equivalent bloc dimensions and upscaling single phase and two phase flow parameters. Available upcaling methods related to single phase parameters reached maturity. Otherwise, upscaling two phase flow parameters is still an open research topic requiring identifying the type of the forces controlling flow in the fractured reservoir (gravity, capillary forces, and viscous forces). During this PhD work, mathematical and numerical models related to DFM and dual medium simulations were explored. A study of the state of the art related to upscaling methods was done. A new and original method allowing determining the dual medium equivalent bloc dimensions (OBS method) was settled down. A dimensional analysis aiming at identifying the type of the forces controlling matrix-fracture exchanges (capillarity, viscous forces) in a water-oil two phase flow within naturally fractured reservoirs without gravity was settled down. The derived capillary number was tested. Finally, an equivalent two phase flow parameters upscaling workflow was also settled down. This workflow treats the particular case of a two phase flow in naturally fractured reservoirs with an heterogeneous matrix medium in a context of matrix-fracture exchanges ruled by viscous forces.