The purpose of this study was to compare the thickness of dentin removed from the buccal root of bifurcated maxillary first premolars (BMFP) in the area of furcation groove after instrumentation with WaveOne and LightSpeed LSX files utilizing limited field cone beam computerized tomography. All data was analyzed using repeated-measured mixed-model ANOVA and differences were described using Tukey’s multiple comparison procedure. The thickness of dentin removed with LightSpeed LSX files (0.1 mm) was significantly less than the thickness of dentin removed with WaveOne files (0.2 mm). To conclude, LSX files remove a more predictable and consistent thickness of dentin from the buccal root of BMFP, irrespective of the pre-instrumentation thickness of dentin and the file size when compared to WO files that remove a more variable thickness of dentin.

Este trabalho tem como propósito investigar como a variação geométrica de determinados parâmetros envolvidos na construção de uma geometria bifurcada de seção circular, em forma de Y, afeta a resistência ao escoamento, tanto de fluidos newtonianos como não newtonianos. As geometrias estudadas foram construídas utilizando-se o princípio do Design Construtal. Os parâmetros variados foram a relação entre os comprimentos dos dutos pais e filhos, a relação entre os diâmetros dos mesmos dutos, e o ângulo central da estrutura em forma de Y. Para as relações geométricas lineares foram utilizados os valores de 0,5; 0,6; 0,7; 0,8; 0,9 e 1, enquanto para os ângulos, foram utilizados os valores de 155°, 135°, 115°, 95°, 75°, 45°, 25° e 10°. Os fluidos utilizados foram do tipo newtoniano e não newtoniano, dentre estes últimos, foram estudados fluidos pseudoplásticos e dilatantes. O trabalho foi realizado através de simulações numéricas, implementadas com a utilização do software comercial Ansys Fluent, o qual resolve as equações governantes através do método dos volumes finitos. As malhas utilizadas foram do tipo poliédrica. Os resultados indicam que há uma diferença em relação ao que se espera da literatura para as relações entre os diâmetros e os comprimentos. A Lei Hess-Murray indica que estas relações ótimas seriam de 2-1/3 para as relações entre os diâmetros e comprimentos. No presente trabalho, foram determinadas relações entre os diâmetros próximas de 0,6, e entre os comprimentos, iguais a 1. Os ângulos ótimos ficaram localizados no intervalo entre 100° e 135°. / This work aims to investigate how the geometric variation of certain parameters involved in the construction of a bifurcated Y-shaped circular cross-section geometry affects the flow resistance of both Newtonian and non-Newtonian fluids. The geometries studied were constructed using the Constructal Design principle. The parameters were the relationship between the lengths of the daughter and parent ducts, the relationship between the diameters of the same ducts, and the central angle of the Y-shaped structure. For the linear geometric relations, values of 0.5; 0.6; 0.7; 0.8; 0.9 and 1 where used, for the angles, the values of 155 °, 135 °, 115 °, 95°, 75 °, 45 °, 25 ° and 10 ° were used. The fluids used were of the Newtonian and non-Newtonian type, among the latter, pseudo plastic and dilatant fluids were studied. The work was carried out through numerical simulations, implemented with the commercial software Ansys Fluent, which solves the governing equations through the finite volume method. The meshes used were of the polyhedral type. The results indicate that there is a difference in relation to what is expected from the literature for the relationships between diameters and lengths. The Hess-Murray Law indicates that these optimal relations would be 2-1/3 for the relationships between diameters and lengths. In the present work, relationships between the diameters close to 0,6 were found and s equal to 1 between the lengths. The optimum angles were located in the range between 100 ° and 135 °.

Using an institutional ethnographic approach, this research explores the everyday experiences of women living with Multiple Sclerosis and the work they do to understand and manage their illness. Starting with the women's own accounts of their everyday experiences with MS, this research analyzes and explicates the social relations that are involved in their everyday taken-for-granted lifework. An exploration of the ruling institutions coordinating with the everyday work of these women provides insight to some of the struggles and problems people with MS encounter. This project explicates and problematizes the disjuncture between the actual lived experience of having MS and the biomedical institution's authority over the illness. / Graduate

Este trabalho tem como propósito investigar como a variação geométrica de determinados parâmetros envolvidos na construção de uma geometria bifurcada de seção circular, em forma de Y, afeta a resistência ao escoamento, tanto de fluidos newtonianos como não newtonianos. As geometrias estudadas foram construídas utilizando-se o princípio do Design Construtal. Os parâmetros variados foram a relação entre os comprimentos dos dutos pais e filhos, a relação entre os diâmetros dos mesmos dutos, e o ângulo central da estrutura em forma de Y. Para as relações geométricas lineares foram utilizados os valores de 0,5; 0,6; 0,7; 0,8; 0,9 e 1, enquanto para os ângulos, foram utilizados os valores de 155°, 135°, 115°, 95°, 75°, 45°, 25° e 10°. Os fluidos utilizados foram do tipo newtoniano e não newtoniano, dentre estes últimos, foram estudados fluidos pseudoplásticos e dilatantes. O trabalho foi realizado através de simulações numéricas, implementadas com a utilização do software comercial Ansys Fluent, o qual resolve as equações governantes através do método dos volumes finitos. As malhas utilizadas foram do tipo poliédrica. Os resultados indicam que há uma diferença em relação ao que se espera da literatura para as relações entre os diâmetros e os comprimentos. A Lei Hess-Murray indica que estas relações ótimas seriam de 2-1/3 para as relações entre os diâmetros e comprimentos. No presente trabalho, foram determinadas relações entre os diâmetros próximas de 0,6, e entre os comprimentos, iguais a 1. Os ângulos ótimos ficaram localizados no intervalo entre 100° e 135°. / This work aims to investigate how the geometric variation of certain parameters involved in the construction of a bifurcated Y-shaped circular cross-section geometry affects the flow resistance of both Newtonian and non-Newtonian fluids. The geometries studied were constructed using the Constructal Design principle. The parameters were the relationship between the lengths of the daughter and parent ducts, the relationship between the diameters of the same ducts, and the central angle of the Y-shaped structure. For the linear geometric relations, values of 0.5; 0.6; 0.7; 0.8; 0.9 and 1 where used, for the angles, the values of 155 °, 135 °, 115 °, 95°, 75 °, 45 °, 25 ° and 10 ° were used. The fluids used were of the Newtonian and non-Newtonian type, among the latter, pseudo plastic and dilatant fluids were studied. The work was carried out through numerical simulations, implemented with the commercial software Ansys Fluent, which solves the governing equations through the finite volume method. The meshes used were of the polyhedral type. The results indicate that there is a difference in relation to what is expected from the literature for the relationships between diameters and lengths. The Hess-Murray Law indicates that these optimal relations would be 2-1/3 for the relationships between diameters and lengths. In the present work, relationships between the diameters close to 0,6 were found and s equal to 1 between the lengths. The optimum angles were located in the range between 100 ° and 135 °.

Este trabalho tem como propósito investigar como a variação geométrica de determinados parâmetros envolvidos na construção de uma geometria bifurcada de seção circular, em forma de Y, afeta a resistência ao escoamento, tanto de fluidos newtonianos como não newtonianos. As geometrias estudadas foram construídas utilizando-se o princípio do Design Construtal. Os parâmetros variados foram a relação entre os comprimentos dos dutos pais e filhos, a relação entre os diâmetros dos mesmos dutos, e o ângulo central da estrutura em forma de Y. Para as relações geométricas lineares foram utilizados os valores de 0,5; 0,6; 0,7; 0,8; 0,9 e 1, enquanto para os ângulos, foram utilizados os valores de 155°, 135°, 115°, 95°, 75°, 45°, 25° e 10°. Os fluidos utilizados foram do tipo newtoniano e não newtoniano, dentre estes últimos, foram estudados fluidos pseudoplásticos e dilatantes. O trabalho foi realizado através de simulações numéricas, implementadas com a utilização do software comercial Ansys Fluent, o qual resolve as equações governantes através do método dos volumes finitos. As malhas utilizadas foram do tipo poliédrica. Os resultados indicam que há uma diferença em relação ao que se espera da literatura para as relações entre os diâmetros e os comprimentos. A Lei Hess-Murray indica que estas relações ótimas seriam de 2-1/3 para as relações entre os diâmetros e comprimentos. No presente trabalho, foram determinadas relações entre os diâmetros próximas de 0,6, e entre os comprimentos, iguais a 1. Os ângulos ótimos ficaram localizados no intervalo entre 100° e 135°. / This work aims to investigate how the geometric variation of certain parameters involved in the construction of a bifurcated Y-shaped circular cross-section geometry affects the flow resistance of both Newtonian and non-Newtonian fluids. The geometries studied were constructed using the Constructal Design principle. The parameters were the relationship between the lengths of the daughter and parent ducts, the relationship between the diameters of the same ducts, and the central angle of the Y-shaped structure. For the linear geometric relations, values of 0.5; 0.6; 0.7; 0.8; 0.9 and 1 where used, for the angles, the values of 155 °, 135 °, 115 °, 95°, 75 °, 45 °, 25 ° and 10 ° were used. The fluids used were of the Newtonian and non-Newtonian type, among the latter, pseudo plastic and dilatant fluids were studied. The work was carried out through numerical simulations, implemented with the commercial software Ansys Fluent, which solves the governing equations through the finite volume method. The meshes used were of the polyhedral type. The results indicate that there is a difference in relation to what is expected from the literature for the relationships between diameters and lengths. The Hess-Murray Law indicates that these optimal relations would be 2-1/3 for the relationships between diameters and lengths. In the present work, relationships between the diameters close to 0,6 were found and s equal to 1 between the lengths. The optimum angles were located in the range between 100 ° and 135 °.

An aerodynamic and acoustic investigation was performed on two small-scale supersonic inlets to determine which inlet would be more suitable for a High Speed Civil Transport (HSCT) aircraft during approach and takeoff flight conditions. The comparison was made between an axisymmetric supersonic P inlet and a bifurcated two-dimensional supersonic inlet. The 1/14 scale model supersonic inlets were used in conjunction with a 4.1 in (10.4 cm) turbofan engine simulator to provide the typical characteristics of a turbofan aircraft engine. A bellmouth was utilized on each inlet to eliminate lip separation commonly associated with airplane engine inlets that are tested under static conditions. Steady state measurements of the aerodynamic flowfield and acoustic farfield were made in order to evaluate the aeroacoustic performance of the inlets. The aerodynamic results show the total pressure recovery of the two inlets to be nearly identical, 99% at the approach condition and 98% at the takeoff condition. At the approach fan speed (60% design speed), there was no appreciable difference in the acoustic performance of either inlet over the entire 0° to 110° farfield measurement sector. The inlet flow field results at the takeoff fan speed (88% design speed), show the average inlet throat Mach number for the P inlet (Mach 0.52) to be approximately 2 times that of the 2D inlet (Mach 0.26). The difference in the throat Mach number is a result of the smaller throughflow area of the P inlet. This reduced area resulted in a “soft choking” of the P inlet which lowered the blade passing tone of the simulator by an average of 9 dB in the forward sector, when compared to the 2D inlet. / Master of Science

M.A. Faculty of Humanties, University of the Witwatersrand / The racial discrimination under colonialism and apartheid culminated to the dispossession of black people from their land, and to unequal land distribution between black and white people. Territorial segregation during this period was not only about the displacement of black people from their land and their deprivation to equal access to land compared to their white counterparts, it was also about economic deprivation, eradication of subsistence agriculture and the transformation of blacks into wage labourers (Hall, 2004; Walker, 2008).The post-apartheid land reform process was initiated to redress the injustices and inequalities of the past. It took a market-driven approach to blend the objectives of land reform with those of national reconciliation and maintenance of food security (DLA, 1997). The land reform process took a form of restoring land to its original owners who were forcefully removed from it after June 1913 or compensation if land could not be restored. It was also aimed at securing tenure rights for farm workers, labour tenants, farm dwellers and people residing in communal areas. The aims of the third part of the land reform programme was to redistribute 30% of commercial farms in white hands to black people with the view of redressing racial disparities in landholding. As early as in the initial stages of the development of South Africa’s land policy in the early 1990s, scholars and civil society groups warned about the ineffectiveness of the market to deliver on land reform objectives. This paper adopts a case study approach to study the South African land reform process in relation to the notion of empowerment. It focuses on the Land Reform for Agricultural Development (LRAD) sub-programme by looking at the intersection between race, gender and class. Bambanani Fruits (Pty) Ltd, an LRAD project based in the Gauteng province is used as a case study. This is an LRAD Equity Scheme project, meaning that its beneficiaries (who are former workers on the farm) acquired an LRAD grant to purchase equity shares to be co-owners of the project. Bambanani Fruits is a successful project considering its productivity and access to the market. This paper investigates how much LRAD beneficiaries are part of this success i.e. whether they have agency, whether they feel a sense of ownership and control of the project, and the extent at which they take part in decision making in the project. This task is carried out through the application of Kabeer’s (1999) instrumentalist model of measuring empowerment. Kabeer states that empowerment is measured by looking at three aspects, namely; resources, agency and achievement. Kabeer’s model is applied to the data which was collected through various means including in depth interviews with Bambanani LRAD beneficiaries and land officials from the province, document analysis and review of existing scholarly work on land reform. It is well documented that South Africa’s land reform process has been very slow in delivering to its objectives, and departmental reports used in this paper also confirm this assertion. The research results reveal that even though more land was transferred under LRAD, the sub-programme also encountered some of the challenges and hindrances faced by its predecessor Settlement/Land Acquisition Grant (SLAG). It faced budgetary constraints, complexities of the land market such as price restrictions and resistance by land owners to cede land, and so on. Generally, it was found that LRAD tended to entrench race, gender and class disparities in landholding. At Bambanani, I discovered that LRAD has affected beneficiaries differently. The sub-programme has stratified these beneficiaries into competing class factions. Divergent interests have emerged to distort the actual meaning of empowerment. I have labelled this tension a ‘dichotomous factionalism’. The struggle and conflict is caught up between beneficiaries themselves, and their disunity has left the hegemony of the farm’s management unchallenged. I argue that, their empowerment is firstly condemned from within and this internal condemnation limits their negotiating power with the management. Secondly, their empowerment is curtailed by the farm’s management in such as way that it sometimes uses its majority shares to justify unilateral decision making. According to Kabeer, empowerment ought to encompass egalitarian decision making. Respondents have reported this is not always being the case at Bambanani. One group of participants complained about how things have remained the same on the farm despite the acquisition of LRAD shares to co-own the farm. Another group which is mostly comprised by trust members argued that things have changed for the better compared to the period prior to the attainment of these equity shares. In doing so, this group blames the discontent group for the lack of commitment to the project and for being after money over the interest of the project. The discontent group has also complained that the trust is not representing their interests to the management, and whenever they lay complaints there are often threats of expulsion. Apart from the above mentioned conflict of interests amongst Bambanani beneficiaries, positive elements were also discovered where beneficiaries agreed on some areas of dissatisfaction. I have labelled this a Collective Discontent Spectacle. The plight of beneficiaries is caused by the lack of adequate exposure to the business side of the farm’s operation and the lack of delivery on houses which were promised to them by the management as part of the shareholding package. Having considered the Bambanani case and other literature on LRAD, I concluded that LRAD has failed to fulfil empowerment requirements as per Kabeer’s model.