This master thesis deals with the problematics of CT filters and focuses on Gm – C filter. Three linearisation techniques are listed and compared in terms of linear input range, distortion and retuning. In the practical part – second - order low – pass filter is designed and its tuning capabilities are examined.

This master’s thesis deals with the design of tuneable frequency second order filter in CMOS technology. The thesis describes the design of a transconductor and its utilization for tunable gm-C filter. The design and all simulations were made in Cadence Spectre and Virtuoso software. Limitedly Orcad Pspice and SNAP were also used.

In this dissertation, a high-level management strategy was developed for the museums and collections of the University of Pretoria. Specific areas where improvements to the current operations of the University museums can be made, were identified and solutions proposed. This analysis was based on a survey of the current operations of the University museums, as well as an analysis of the needs of all stakeholder groups. Proposals to improve the operation of the University museums include the following: - Rationalising collections to ensure that available technical and organisational resources are focused on the most valuable collections; - Improving the use and maintenance of collections to ensure that the needs of stakeholders are met; - Ensuring that sufficient financial and organisational resources are mobilised to support the operations of the museums. A brief overview of the steps needed to implement these proposals and to adjust the management strategy on an ongoing basis, is given. The author believes that the implementation of the proposals outlined in this report can contribute towards ensuring that the museums of the University of Pretoria help to fulfil the overall mission and vision of the University of Pretoria. / Dissertation (MA)--University of Pretoria, 2001. / Historical and Heritage Studies / unrestricted

This thesis deconstructs the gender symbolism evident in the opera Faust (1859) by Gounod. The objective is to determine the gendered authenticity, originality and contributing nature of the work, acknowledging the Catholic nineteenth-century French context in which it was written. The study aims to establish the nature of the gender constructs portrayed (whether representative of their conservative milieu, or suggestive of unconventionality, liberalism and innovation) and how these portrayals were executed by Gounod and his librettists. An exploration of the construction of Faust and a comparison with Goethe’s Faust: Der Tragödie Erster Teil (1808), on which the Gounodian creation is loosely based, initiates the study. The theory of performativity by Judith Butler (1990), together with other general gender hypotheses on, for instance, masculine and feminine personalities and perversity, follows. Hereafter, gender in the context of artistic performances, and gender constructs in Christianity are investigated. These general, performance-based and theological theories and ideas are then compared to the gendered characters in Faust. The secular and Catholic gender norms that governed men and women in nineteenth-century France inevitably had an influence on how gender is represented in the opera. Hence, contextual aspects, as well as Gounod’s own interaction with, and exhibition of gender are analysed in order to establish their influential extent on Faust. A deconstruction of the opera as three different texts – libretto, score and DVD productions of three Faust performances – is applied since this contributes to holistic and objective conclusions. The aspects investigated in the study have brought to light that Faust shamelessly highlights the destructive consequences of social, cultural and religious gender stereotypes governing nineteenth-century Catholic France, whilst simultaneously proposing liberated gender identities. Gounod is innovative in presenting a female protagonist through the role of Marguerite. She is an intricate, developing character representative of multiple perplexed femininities, many of which are conquering and symbolic of female empowerment. Siébel serves as a source of great gender ambiguity and contradiction. These aspects are fuelled by an ironic female identity – hence, the notion of performativity is ingeniously incorporated into this character. Both femininity and masculinity is advocated in the portrayals of Méphistophèles and the Christian God, while interesting and unexpected masculinities are embodied through Faust and Valentin. By using the above methodology, I suggest that Gounod’s Faust is an authentic and pioneering work representing ambivalent, controversial, contradictory and empowering gender constructs, making it a composition of considerable worth, both musically and historically. NB: Additional information available on a CD stored at the Merensky Library front Counter. / Dissertation (MMus)--University of Pretoria, Pretoria, 2013. / 5 CDs available with the study. Kept at the Open Scholarship Office in the Embargo room. / Music / unrestricted

Process operators often have process faults and alarms due to recurring failures on process equipment. It is also the case that some processes do not have enough input information or process models to use conventional modelling or machine learning techniques for early fault detection. A proof of concept for online streaming prediction software based on matching process behaviour to historical motifs has been developed, making use of the Basic Local Alignment Search Tool (BLAST) used in the Bioinformatics field. Execution times of as low as 1 second have been recorded, demonstrating that online matching is feasible. Three techniques have been tested and compared in terms of their computational effciency, robustness and selectivity, with results shown in Table 1: • Symbolic Aggregate Approximation combined with PSI-BLAST • Naive Triangular Representation with PSI-BLAST • Dynamic Time Warping Table 1: Properties of different motif-matching methods Property SAX-PSIBLAST TER-PSIBLAST DTW Noise tolerance (Selectivity) Acceptable Inconclusive Good Vertical Shift tolerance None Perfect Poor Matching speed Acceptable Acceptable Fast Match speed scaling O < O(mn) O < O(mn) O(mn) Dimensionality Reduction Tolerance Good Inconclusive Acceptable It is recommended that a method using a weighted confidence measure for each technique be investigated for the purpose of online process event handling and operator alerts. Keywords: SAX, BLAST, motif-matching, Dynamic Time Warping / Dissertation (MEng)--University of Pretoria, 2012. / Chemical Engineering / unrestricted

This dissertation reports on a study that investigated the functions and services that are rendered at the library of ARC-Small Grain Institute in Bethlehem. The study was directed by the research questions that included the investigation in library services and sources globally; the information seeking behaviour of the patrons of the library as well as the skills and competencies needed by librarians to render an effective service in a constant changing environment. These components served as a foundation for the development of a proposed service model, which reflects the incorporation of the changing roles of librarians in a research library. The current services and sources of the ARC-SGI library were discussed and compared to other libraries. A systematic review of the literature included the information seeking behaviour and information needs of researchers as well as the skills and competencies of librarians. A mixed-method approach, using both qualitative and quantitative methods, has been applied in the study. Data was collected through questionnaires and fifteen semi-structured interviews were held with selected patrons of ARC-SGI. The findings showed that information needs depends mostly on the different stages of research and flows directly from the type of work that they do. Attention was given to preferred source choices and problems experienced during information seeking. Training needs were addressed as well as the needs for additional information needed from the library. Based on the results, the study proposed a service model for an agricultural library. The model displays the library within the setting of an organisation as it supports the mission and vision of the parent organisation. It illustrates all the interdependent components that are essential for a successful agricultural library. The model also outlines the strategies of on-going evaluation and monitoring of the library services; the information needs and information seeking behaviour of the patrons as well as the challenges facing the library. The study concluded by making certain recommendations that can benefit the library of ARC-SGI, which will be an improvement added to the current services. A few suggestions are made for future research, which have definite advantages for an agricultural library within an organisation. / Dissertation (MIS)--University of Pretoria, 2013. / Information Science / unrestricted

Traditionally cultural landscape of the past involved a dialogue between natural system, human modifications and the value given by humans to the landscape, ultimately nurturing a healthy interaction between human and natural systems. Development pressures on remnants of these past harmonious cultural landscapes threatens the memory and therewith the future possibility of this healthy interaction. With looming exponential urban growth in African cities in the near future, it is important to learn from and protect the few past remnants that are left. The main question that was explored in the dissertation is how a degraded cultural landscape can be regenerated to establish social and ecological health. The hypothesis proposed that degraded cultural landscapes can be regenerated using principles of past cultural landscapes that can reconnect fragmented human and natural systems. A degraded cultural landscape settled against the backdrop of the Witwatersberg Ridge served as the location for the testing of the hypothesis. This site, situated near Danville and Lotus Gardens in Pretoria West is a former leprosy colony called Fort West. The aim of the dissertation was to find methods for the regeneration of the degraded cultural landscape.It was proposed that an integrated methodology be followed that brings together a site’s cultural, natural and economic ‘capital’ or latent potential. The integration of these three capitals was proposed in two ways: through applying five principles of ecological design as set out by Van der Ryn and Cowan (1996); and by raising awareness and educating society and the community as proposed by Farina (2000). This process delivered a set of design guidelines for degraded cultural landscapes. The approach matches biological diversity with cultural diversity, ensuring that that the ecological relevance of a cultural landscape and its capacity to inform and guide other human activities are met. The design intervention was applied at three different scales: framework, master plan and sketch plan. Interventions are proposed at each scale that can improve the natural and social health of Fort West. The cultural, natural and economic capital of the site is harnessed by reconnecting past and existing potential in these three fields and integrating proposed natural and cultural systems in this way. Education and awareness is at the forefront of all proposed interventions. In this way a public space that facilitates the reintroduction of biodiversity and also assists in the regeneration of the Fort West community can be established. / Dissertation ML(Prof)--University of Pretoria, 2012. / Architecture / ML(Prof) / Unrestricted

In humanity’s current condition, the advantages of organic material sources are supplanted by the qualities of synthetics that allow for rapid growth and altered capabilities, whilst man becomes further removed from his natural existence as a being that once possessed the aptitude to understand and work with these materials. Prior to our industrial, mechanised and materialist consumer culture, the direct interaction with the natural world provided humanity with more comprehensive and experiential ground for growth and learning. As we are connected to the world through our senses, space becomes the primary enabler of such a platform. Relying on the haptic qualities of materials and the body’s ability to experience and embody its immediate surroundings, architecture’s role in the integration between man, nature, and industry is explored. As a natural industry with a significant public interface, architecture acts as a mediator between man’s “constructed nature” and his “first nature” – referring to man’s estrangement from his environment. This dissertation investigates the adaptation of industrial buildings to accommodate public interaction whilst responding to the environmental impact that the production of building materials has on the environment. Alternatives to commonly used materials such as glass, steel and carbon fibres were researched, and so hemp, flax and bamboo became the primary elements used in the making of the architecture. / Dissertation MArch(Prof)--University of Pretoria, 2013. / Architecture / MArch(Prof) / Unrestricted

Indiana University-Purdue University Indianapolis (IUPUI) / The innate and adaptive immune responses are critical for host survival. The TNFα/NF-κB signaling pathway is a major regulator of the immune response. The TNFα/NF-κB signaling pathway has also been proposed to play a role in the regulation of hematopoiesis. In the TNFα signaling pathway, full induction of NF-κB (specifically the p65 subunit) dependent transcription is regulated by a co-activator SIMPL. The biological significance of SIMPL in TNFα dependent responses is poorly understood. To study SIMPL in vitro and in vivo in mammalian cells, a knockdown system utilizing shRNA (short hairpin RNA) was used. Analysis of hematopoietic progenitor cells infected with a retrovirus encoding the SIMPL shRNA was used to study the role of SIMPL in hematopoiesis. The ability of progenitor cells lacking SIMPL to grow and differentiate was not compromised. In contrast in the progenitors cells lacking SIMPL, TNFα mediated inhibition of colony formation was significantly enhanced. These growth inhibitory effects of SIMPL were not due to an increase in apoptosis. The enhanced inhibitory affects were specific for TNFα and not found in other common hematopoietic inhibitors (TGF-β1 and IFNγ). Results of this work reveal that SIMPL is a component of the hematopoiesis that is required for TNFα dependent effects upon myeloid progenitors.

Denna studie bygger på Research through Design (Frayling, 1993), d.v.s att undersökningen syftar till att generera ny kunskap genom analys av datorspel och design av en gestaltning. För att uppnå detta används ett annoterat portfolio och dess underliggande principer (Gaver, 2012; Bowers, 2012). Det annoterade portfoliot består av fyra utvalda datorspel och en egenutvecklad gestaltning. Detta portfolio analyseras för att definiera vilka gemensamma och icke-gemensamma designegenskaper som kan observeras. Efter detta presenteras argument för varför utvalda egenskaper kan göra pedagogiskt inriktade datorspel mer effektiva i syftet att utbilda kring-eller minska påverkan av mis-/desinformation i det specifika inlärningssammanhanget. Faran med mis-/desinformation i samhället illustreras genom kontexten av arbetet med den utvecklade gestaltningen, som bygger på COVID-19 mis-/desinformation och dess konsekvenser. Resultat uppnås efter analysering av samtliga designexempel har genomförts och data har genererats för att utveckla vår egna gestaltning baserat på denna information. / This case study is based on Research through Design (Frayling, 1993), i.e. the purpose of the study is to generate new knowledge through analysis and design of computer games. To achieve this an annotated portfolio and its underlying principles are used (Gaver, 2012; Bowers, 2012). The annotated portfolio consists of four selected computer games and one designed by the authors. This portfolio is analysed to define what design features are shared or not shared between the games. After this, arguments are presented as to why the specified features can make educational computer games more effective in the purpose of educating about or to reduce susceptibility to mis-/disinformation in the specific learning context. The danger of mis-/disinformation is illustrated through the context of the work with the designed computer game, which is based on COVID-19 mis-/disinformation and its consequences. Results are achieved after analysis of the four selected computer games has been carried out and data has been generated to enable the development of the authors own game.