O projeto proposto teve como objetivo principal à avaliação do suporte no desempenho do reator anaeróbio operado em bateladas seqüenciais, com agitação, contendo biomassa imobilizada no tratamento de esgoto sanitário do Campus da USP em São Carlos. O estudo do desempenho global deste tipo de configuração de reator é extremamente vinculado com o suporte inerte o qual proporciona a aderência e crescimento da biomassa. Neste trabalho foram estudados três suportes inertes: espuma de poliuretano, carvão vegetal e polietileno de baixa densidade reciclado. A avaliação global foi realizada sob análise de três diferentes e dependentes variáveis locais: o desempenho do reator, a análise cinética e os exames microbiológicos. A espuma de poliuretano pôde ser considerada como sendo o material mais adequado para tal finalidade, apresentando maiores eficiências de redução da DQO de amostras brutas e filtradas de 61% e 71%, respectivamente, o melhor coeficiente cinético aparente de primeira ordem (k1T): 0,52 ± 0,04 h-1, e uma biomassa predominantemente caracterizada por arqueas metanogênicas e bactérias fototróficas. O carvão vegetal apresentou resultados intermediários, no entanto não satisfatórios, na redução de DQO e ainda uma biomassa não compatível com a esperada para um tratamento anaeróbio biológico. Ou seja, pode-se inferir que neste tipo de suporte houve seleção de biomassa inadequada para se tratar esgoto sanitário. Por fim, o polietileno apresentou os resultados menos expressivos, porém, dada sua caracterização microbiológica constatou-se ser um suporte com potencial para o tratamento de esgoto sanitário quando nele for aplicado um tratamento prévio, objetivando melhores características físico-químicos, como rugosidade, por exemplo. / The main objective of this study was the evaluation of bed materials on the performance of an anaerobic sequencing batch biofilm reactor, with agitation, treating sewage wastewater of the Campus of University of São Paulo in São Carlos. The study of the global performance of this reactor configuration is extremely linked with the bed material which provides adhesive and growing conditions. In this work three different bed materials were investigated : polyurethane foam, vegetal carbon and recycled low-density polyethylene. The global evaluation was performed under analysis of three different and dependant local variables: the reactor performance, kinetic analyses and microbial exams. The polyurethane foam was considered the most suitable material. Using the polyurethane foam as a bed material were obtained the highest COD removal efficiencies, 61% and 71% corresponding to total and filtered samples, respectively. In Addition, the polyurethane foam showed the best modified first-order kinetic model (k1T) of 0,52 ± 0,04 h-1, and a biomass predominately characterized by microorganisms resembling to methanogenic archea and phototrophic bacteria . The vegetal carbon showed intermediate results, which were not satisfactory enough, in the COD removal. Also, the vegetal carbon showed an incompatible biomass in accordance with the expected anaerobic biomass. In others words, it can be inferred that, using this type of material, there was a selective biomass process in which an inappropriate biomass was selected. Finally, the recycled low-density polyethylene showed the less expressive results. However, because of its microbial characterization, it can be concluded that the polyethylene material has potential to be applied as a bed material in the sewage wastewater treatment. Nevertheless, a previous treatment physics-chemical must be applied in this kind of bed material to improve the physics-chemical properties such as porosity and surface area.

With the transition to a new philosophy of education in post-apartheid South Africa a paradigm shift began from banking education to outcomes-based education. South Africa looked to other countries for a framework on which to build its curriculum. The first post-apartheid curriculum as well as the subsequent revised curriculum seems to be a contentious matter as outcomes-based education as practised in South Africa is widely criticised by educationists. This study endeavours to interrogate the structure and underlying principles of the current curriculum to gain an understanding of whether and how critical consciousness, learning support materials and environmental education feature in the national curriculum. The purpose of the study is to gain an understanding of what happens in South African environmental education classrooms especially with regard to the construction of meaning and the prospects for Freirean critical education. The research questions elucidate the nature of critical education and its capacity to inform the sociology of learning in environmental education within the South African context. The research purpose is therefore exploratory and descriptive. The research questions emerge from the literature review which informs the study and also conceptualises the key tenets of the inquiry. The literature study reveals that there is adequate mention in policy documents regarding the importance of learning support materials in teaching and learning, but there seems to be a gap in the literature about how learning support materials are currently used in South Africa to develop critical consciousness particularly in environmental education classrooms. This research attempts to address this gap. The research conducted falls within the conceptual framework of critical pedagogy. It is however the humanist approach asserted by Paulo Freire that premises the study. The research design and philosophy of the study is delineated and the researcher’s role in the research process is elucidated. An ethnographic case study positioned within the qualitative approach serves as the methodology by which the research questions are explored. The choice of methodology and the ontological premise of the study are accounted for and issues of quality are discussed with regard to credibility, transferability, dependability and conformability. The purpose of this study was not to find solutions and no definitive answers were sought or obtained. The findings of the study point to three critical contentions and the following was established: Firstly, that although the National Curriculum Statement pays lip service to some of the ideals of Freirean pedagogy, it is inherently behaviourist in that it has clearly defined outcomes and assessment standards that learners should attain regardless of learner diversity. Secondly, that the manner in which the educator facilitates the learning support materials is the determining factor in the attainment of the set learning outcomes by the learners. Thirdly, that the manner in which knowledge transmission happens in a lesson influences the development of critical consciousness in learners. The findings only serve as suggestions and the reader is invited to look at the possibilities that Freirean pedagogy has to offer and what might be possible in environmental education classrooms. The findings of the study cannot be generalised and have to be interpreted and applied by the reader within a specific context of teaching and learning. / Dissertation (MEd)--University of Pretoria, 2009. / Humanities Education / unrestricted

The establishment of a culture of teaching and learning in disadvantaged high schools is a challenging phenomenon since the inception of the new democratic South Africa. This study attempts to investigate variables contributing towards the establishment of a culture of teaching and learning in high schools. It is revealed through literature study that some investigations into this research topic has already been done in South Africa, but little if none is done in the disadvantaged high schools in the North-West Province, that is the reason why I was prompted to pursue this topic further. The high failure rate in Grade 12 results according to my opinion is a serious concern and is on the lips of every teacher, learner, parent, politician and relevant stakeholders. This high failure rate is, according to the findings from the literature review, caused by factors such as underqualified and unqualified teachers, inadequate resources, over-crowded classrooms, poor infra-structures (buildings), poor socio economic background of learners’ parents, inconducive environment at school and inadequate role played by teachers and learners in the teaching and learning situation. One expects that the majority of disadvantaged schools would have achieved above the 70% as the pass rate benchmark in the final Grade 12 examinations. However, in most schools in the disadvantaged area this is not the case. Based on the above statement and the complexity of the study in consultation with variables employed, I opted to use both quantitative and qualitative research designs with an aim to attempt to obtain consistency, validity and reliability of the research results. The analyses of the results reveal that most disadvantaged schools still experience a poor culture of teaching and learning. This is evidenced by low Grade 12 pass rate results in some of the provinces, including North-West. The research revealed that the variables impacting on the performance of learners at schools are subjected to a complexity of integrated activities many of which are difficult to isolate as predominantly responsible for poor performance as such. What does appear to be an issue of concern is the apparent lack of dedication one would expect from some teachers working with secondary school learners. One could conclude from the many responses that poor achievement is directly linked to poor teaching and that the latter would again be the result of poor qualifications, lack of resources, poor support systems and most important however, a lack of commitment and dedication needed to ensure a professional approach towards classroom management and teaching. / Dissertation (PhD (Curriculum and Instructional Design and Development))--University of Pretoria, 2006. / Curriculum Studies / unrestricted

Cette thèse est consacrée à l’étude des mécanismes de dégradation de noirs de carbone de forte surface spécifique (HSAC) utilisés comme supports d’électrocatalyseurs dans une pile à combustible à membrane échangeuse de protons (PEMFC). Nous avons montré que le mécanisme et les cinétiques de la corrosion électrochimique du carbone (COR) sont influencés par la présence d’ionomère Nafion®, la limite supérieure de potentiel électrochimique, la nature et le nombre de caractérisations intermédiaires présentes dans des tests de dégradation accélérés. En utilisant la spectroscopie Raman,il apparaît que la COR est sensible à la structure cristallographique des HSAC et procède plus rapidement sur les domaines désordonnés (carbone amorphe, cristallites de graphite présentant des défauts). Le taux de recouvrement en espèces oxygénées évalué par spectroscopie de photoélectrons X a été comparé à celui trouvé en intégrant l’intensité du pic quinone/hydroquinone (Q/HQ) envol tampérométrie cyclique. Finalement, une comparaison avec des matériaux carbonés ayant fonctionné pendant 12860 heures en PEMFC confirme nos principaux résultats et permet d’élaborer des stratégies pour atténuer les conséquences de la COR. / This thesis investigates the degradation mechanism of high surfacearea carbon (HSAC) supports used in proton-exchange membrane fuel cell (PEMFC) electrodes. The structural and the chemical properties of different HSAC supports were established. The effectof the Nafion® ionomer used as a proton conductor, the gas atmosphere, the upper potential limit and the intermediate electrochemical characterizations used to monitor the changes ofthe electrochemical surface area during accelerated stress tests(ASTs) were investigated. The long-term physical and chemical changes of Pt/HSAC electrocatalysts were investigated insimulated PEMFC operating conditions. Using Raman spectroscopy, we showed that the COR is strongly structure sensitive and proceeds more rapidly on disordered domains of the HSAC (amorphous carbon and defective graphite crystallites) thanon graphitic domains. The coverage with carbon surface oxides was investigated with X-ray photoelectron spectroscopy and bridged tothe intensity of the quinone/hydroquinone (Q/HQ) peak monitored by cyclic voltammetry. Finally, the analyses realized on membrane electrode assemblies operated for 12,860h disclosed a perfect agreement between model and real PEMFC operating conditions, and confirmed the structural dependency of the COR kinetics.

The purpose of this study was to explore teachers’ experiences of curriculum change in two under-resourced primary schools in the Durban area. By examining the experiences of educators using a qualitative approach the researcher was able to identify problems that prevent a smooth transition from one curriculum to another. The introduction of the Curriculum Assessment Policy Statements in January 2012 necessitated a plethora of adjustments for teachers at schools. Changes were made to the number of subjects to be taught, the notional time for each subject as well as a renewed emphasis on textbooks as a vital teaching resource in the classroom. This study was conducted in under-resourced primary schools in the Durban area. Data collection in both these schools shows that despite the lack of essential resources such as text books, teachers still manage to implement change and follow policy, whilst at the same time ensuring that their learners benefit from the curriculum. This study also highlights the challenges experienced by teachers in under-resourced schools that need to be confronted for effective curriculum implementation. The researcher makes recommendations to address these challenges as well as suggestions for future research. / Curriculum and Instructional Studies / M. Ed. (Curriculum Studies)

The purpose of this study was to explore teachers’ experiences of curriculum change in two under-resourced primary schools in the Durban area. By examining the experiences of educators using a qualitative approach the researcher was able to identify problems that prevent a smooth transition from one curriculum to another. The introduction of the Curriculum Assessment Policy Statements in January 2012 necessitated a plethora of adjustments for teachers at schools. Changes were made to the number of subjects to be taught, the notional time for each subject as well as a renewed emphasis on textbooks as a vital teaching resource in the classroom. This study was conducted in under-resourced primary schools in the Durban area. Data collection in both these schools shows that despite the lack of essential resources such as text books, teachers still manage to implement change and follow policy, whilst at the same time ensuring that their learners benefit from the curriculum. This study also highlights the challenges experienced by teachers in under-resourced schools that need to be confronted for effective curriculum implementation. The researcher makes recommendations to address these challenges as well as suggestions for future research. / Curriculum and Instructional Studies / M. Ed. (Curriculum Studies)