Academical dissertation--Uppsala.

Thèse--Philosophie et lettres--Liège, 1981. / Bibliogr. p. 21-28.

This research studied the effects of the addition of ground granulated blast furnace slag (ggbs), activated by 2% calcium hydroxide (Ca(OHh, on the strength, permeability and porosity development of a laboratory prepared clay mix (kaolinite with and without 6% gypsum) and a natural sulphide-bearing clay soil, Lower Oxford Clay. Based on shear, compressive and indirect tensile strength testing, it was found that an increase in the stabiliser slag/lime ratio results in substantial strength increase even after short curing periods (up to 12 weeks). This increase in strength is more pronounced if curing is at elevated temperatures (30 °C). The presence of sulphates (6% gypsum=2.73% SO3) resulted in an accelerated increase in the strength development for stabilised kaolinite, which was comparable to that of stabilised Lower Oxford Clay. In the absence of sulphates, large ggbs additions were only activated effectively at higher curing temperatures (20 and 30 °C) after curing periods of 24 weeks and beyond, although it is suggested that 2% lime creates a sufficiently alkaline environment for activation. The degree of slag activation and thus the subsequent cementation process was reflected by an increase in the percentage of the pore volume occupied by pores with a radius ::s;0.0Sμm, which is usually associated with the pore fraction characteristic of cementitious gels. The increase in slag addition, for kaolinite mixes, was accompanied by a reduction in total porosity. Specimens made from Lower Oxford Clay exhibited a significant increase in pore volume at higher slag additions. This is interpreted as being due to the creation of pore space resulting from restrained shrinkage of gels by inert particles during drying in this coarser, natural clay. No significant trend in the effect of curing temperature on the pore size distribution could be identified from the data. The development of permeability, however, showed some sensitivity to curing temperature. Results from specimens cured at 20 and 30 °C showed an accelerated reduction in their k-values in comparison to samples which had been cured at 10 °C. However, little correlation between measured permeability and exhibited pore size distribution could be established which is believed to be due to the strong influence of shrinkage during drying prior to mercury intrusion porosimetry in the dimensionally semi-stable soil system. The volume stability of stabilised specimens during frost action was assessed in a series of 12 freeze-thaw cycles, which were carried out in accordance to the German proposal for a European Pre-Standard. Generally an increase in the curing period prior to frost action and higher overall sample porosity resulted in relatively better performance during frost action. The influence of the slag/lime and slag/gypsum ratio on the swelling potential upon soaking was assessed in long-term soaking tests and the underlying causes were identified by findings from microstructural investigations including SEM and TG analysis. These results contributed to a better understanding of the slag activation process. In an alkaline environment slag hydration appears to be triggered earlier by sulphate, due to the more intensive disturbance of a thin protective layer of cementitious products on the slag grains. Disruption of this layer, for example by ettringite formation, exposes more unreacted slag grain surface, which will subsequently start to hydrate. Findings were complemented by two case studies, one which investigated the cause of substantial heave on a German highway on a microscale and the other which assessed the technical performance and the economic implications of a full-scale trial utilising the stabilisation technique with lime and ggbs for a temporary diversion. The overall findings from the projects indicate that soil stabilisation with lime and ggbs is, particularly for soils with significant sulphate/sulphide content, a feasible and environmentally friendly alternative to the classic soil stabilisation methods.

No description available.

No description available.

No description available.

Submitted by Nadir Basilio (nadirsb@uninove.br) on 2016-05-25T14:58:26Z No. of bitstreams: 1 Luciane Beatriz Grohs Contani .pdf: 1089734 bytes, checksum: bd72d901079afdcce655c14f8b2549a8 (MD5) / Made available in DSpace on 2016-05-25T14:58:26Z (GMT). No. of bitstreams: 1 Luciane Beatriz Grohs Contani .pdf: 1089734 bytes, checksum: bd72d901079afdcce655c14f8b2549a8 (MD5) Previous issue date: 2014-12-11 / The aim of the present study was to analyze the Oxford Foot Model (OFM) repeatability of healthy adults during two clinical tests: the Anterior Step down Test (ASDT) and the Lateral Step down Test (LSDT). Five healthy participants (one male, four females, 10 limbs in total), with a mean age of 22.2 (±4.7) years, were assessed in four sessions of tests using an interval of one week. Two independent examiners performed two sessions of each of the tests. For each session (intra-day), nine repetitions were carried out for each clinical test (ASDT and LSDT). After an interval of three hours, the data were collected once more. The tests were conducted after an interval of a week, using the same experimental conditions. The intra and inter-session repeatability of the range of motion of the foot was determined by the standard error of measurement (SEM) of each examiner and between the examiners. Differences between the test and the retest, as well as between the examiners, were assessed using the students t-test (p<0.05). The repeatability of the data was high for the two tests conducted. The SEM results were as follows: 0.26º to 1.59º for the intra-examiner assessment (ASDT); 0.28º to 1.31º for the inter-examiner comparison (ASDT); 0.02º to 1.03º for the intra-examiner assessment (LSDT); 0.28º to 1.00º for the inter-examiner comparison (LSDT). The OFM model was shown to be reproducible in terms of assessing the range of motion during functional tests (ASDT and DAS) in healthy adults. / Os modelos convencionais usados na análise tridimensional da marcha representavam o pé como um único segmento rígido. Desta forma, são considerados, na grande maioria dos laboratórios clínicos e de pesquisa, apenas os movimentos de flexão plantar e dorsiflexão devido a sua fragilidade para mensurar outros movimentos. Por ser o pé uma estrutura complexa, é necessário tratá-lo de maneira multissegmentar. Pesquisas recentes sobre a análise de marcha, têm utilizado o Oxford Foot Model (OFM), que trata o pé de forma segmentada. Uma vez que um modelo é proposto, o estudo de sua reprodutibilidade deve ser realizado em movimentos que ainda não foram estudados, no intuito de identificar possíveis variações entre os dados obtidos, pois os mesmos podem comprometer a interpretação dos resultados e a tomada de decisão clínica. Dessa forma, este estudo tem por objetivo avaliar a reprodutibilidade do Oxford Foot Model em adultos saudáveis durante testes funcionais, notadamente Single Leg Step Down Test Anterior (SDA) e Lateral Step Down Test (SDL), que são exercícios realizados em cadeia cinética fechada. Foi analisada a cinemática do pé de cinco adultos saudáveis (com idade de 22,2 +/- 4,7 anos) durante quatro sessões para cada um dos avaliadores (dois fisioterapeutas). Os resultados apontam alta reprodutibilidade do modelo para estes testes funcionais quando se analisa o erro padrão de medida e a amplitude de movimento articular. Foram encontradas diferenças estatisticamente significativas apenas em três comparações para a atividade SDL, o que aponta a reprodutibilidade do método. Para o SDA também foram encontradas três diferenças, concentradas nas comparações de mesmo dia. O presente estudo mostrou que o número mínimo de repetições (trials) é de três a cinco, por conterem menor erro padrão de medida; para fins estatísticos aqui elencados utilizaram-se cinco repetições.

Since there are insufficient mathematicians to meet economic and educational demands and many well-qualified, successful mathematics students exhibit signs of disaffection, the student experience of undergraduate mathematics is high on the political agenda. Many undergraduates struggle with the school-university transition, which has been associated with students’ prior experiences of mathematics which, at A-level, are regularly criticised for being too easy and too different to undergraduate mathematics. Furthermore, the University of Oxford administers a Mathematics Admissions Test (OxMAT) as a means of identifying those best prepared beyond the limited demands of A-level. Consequently, a study was conducted into the mathematical enculturation of Oxford undergraduates, specifically in terms of examination questions and students’ approaches to learning. Analysis of the Approaches and Study Skills Inventory for Students (ASSIST) (Tait et al., 1998) revealed the majority of students to adopt strategic approaches to learning (ATLs) in all four year-groups, though the descriptions given by students in interviews of the nature of their ATL highlighted some shortcomings of the ASSIST as the motivation for memorisation appeared to be an important factor. The MATH taxonomy (Smith et al., 1996), revealed that most A-level questions require routine use of procedures, whereas the OxMAT tested a variety of skills from applying familiar mathematics in new situations to justifying and interpreting information to form proofs. This is more in-line with the requirements of undergraduate assessment, although the MATH taxonomy and student interviews revealed that these still allowed for rote memorisation and strategic methods. Thus, the changing nature of mathematics and questions posed to students at the secondary-tertiary interface appears to affect students’ ATLs, though this is not reflected by the ASSIST data.

No description available.

When a black student threw feces against a bronze statue of British imperialist, Cecil John Rhodes, located at the University of Cape Town (UCT), it sparked the formation of the #RhodesMustFall (#RMF) student movement in March 2015. The Black-led #RMF movement sought to decolonize the university by confronting institutional racism and patriarchy at UCT through a series of disruptive and creative tactics including occupying university buildings and erecting a shack on campus. As part of their decolonization process, black students tried to make sense of their experiences in a predominantly white university by de-linking from UCT’s dominant model of Euro-American knowledge to construct their own decolonial framework comprised of Pan-Africanism, Black Consciousness and Black radical feminism. A few weeks later in May 2015, students at the University of Oxford in the United Kingdom who were inspired by the student movement at UCT, created the #RhodesMustFall Oxford movement, using the Rhodes statue at Oriel College as a focal point in their call to decolonize the university. This dissertation explores the formation of the radical #RMF student movements at UCT and Oxford—referred to as the Fallist movements. I first consider what led the #RMF movement at UCT to adopt a decolonial framework centered on Black radical feminism, Black Consciousness, and Pan-Africanism, and then examine how the #RMF’s decolonial framework generated the emergent idea of “Fallism” that extended beyond the students’ demand for the Rhodes statue to fall. Finally, I assess the ways in which the formation of #RMF Oxford was influenced by the #RMF movement in Cape Town. The #RMF mission statement characterized the black experience at UCT as “black pain” or as “the dehumanization of black people” informed by the “violence exacted only against black people by a system that privileges whiteness”. In order to better understand their experiences of black pain, student activists de-linked from the university's dominant knowledge production systems that privileged whiteness through its epistemic architecture. The #RMF UCT movement’s de-linking or “epistemic disobedience”, was also employed by students at Oxford who wanted to integrate “subjugated and local epistemologies” into the Eurocentric university curriculum. Based on this empirical analysis of the #RMF’s engagement in epistemic disobedience at both UCT and Oxford, I argue that the university occupies a paradoxical position for Black and other marginalized bodies: it is simultaneously empowering and dehumanizing; it offers the possibility of acquiring knowledge that could serve as a liberatory tool from the violence of socio-economic marginality (Black liberation), while at the same time, the physical and epistemic architecture of the university can create an oppressive, alienating space for Black, queer and disabled bodies among others (Black pain). This assertion leads me to experiment with developing Fallism into an emergent decolonial option that emanates from acts of epistemic disobedience to unveil the hegemonic intellectual architecture of the university. Through a combination of 98 interviews, one year of observations, and document analysis, this study offers insights into the formation and evolution of the #RMF student movements at UCT and Oxford, while contributing to a critical understanding of the university’s paradoxical epistemic architecture.