64962 research outputs found
Sort by
Gap Waveguide Array Element Filters
No full textThesis (PhD)--Stellenbosch University, 2025.Fourie, J. D. 2025. Gap Waveguide Array Element Filters. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/c150dce2-e349-4d32-a180-08d50cdc1bdbIn order for the next generation of wireless communications to implement higher data rates, devices operating at higher frequencies such as W-band are required. Control of spectral emissions in integrated mm-wave systems has so far been neglected due to the limited amount of devices operating at the frequency range. Gap waveguides are a type of waveguide implemented in a periodic metamaterial that offer several critical advantages over standard waveguides, especially with regards to manufacturability. This research provides the design and analysis of three gap waveguide filters that are integrated into larger transmitter systems in order to prevent out of band emissions. These types of filters, which are directly integrated with antenna array elements are known as array element filters. The first filter is a third order filter centred at 100 GHz with a bandwidth of 4 GHz and 20 dB of passband return loss that was used to develop several filter components for the other filter designs. The filter was integrated with a slotted waveguide antenna array and the effects of the coupling between adjacent filter channels was investigated. The coupling between adjacent channels altered the farfield radiation pattern of the antenna, especially when beam steering is done on the array. The second filter is a seventh order folded filter that was designed and manufactured to meet the electrical specifications of the transmitter system whilst fitting into a transmitter system and minimising coupling between adjacent channels. The filter was designed with an inline topology with a centre frequency of 101 GHz and a bandwidth of 10 GHz with a transversal fold. The filter was manufactured using computer numerical control (CNC) milling from aluminium. The manufactured filter shifted up in frequency by 1 GHz. The measured response showed a large peak in the return loss at 98 GHz which was found to be due to an increase in the gap height of the gap waveguide structure. The lowest insertion loss measured in the passband was 1.34 dB. The third and final filter, a seventh order filter with a centre frequency of 100 GHz and a bandwidth of 5 GHz, implements transmission zeros in a novel structure that fits under a slotted waveguide antenna. The structure implements two transmission zeros in the upper passband of the structure at 103.7 and 107.5 GHz with a minimum passband return loss of 14 dB. Due to manufacturing costs, filters one and three were not manufactured, only verified through full-wave simulation using CST.Doctora
Ronelda Kamfer, Nathan Trantraal, Lynthia Julius en Ryan Pedro in die Afrikaanse literere sisteem : ’n metatekstuele ondersoek na beeldvorming
No full textThesis (MA)--Stellenbosch University, 2025.Muller, A. 2025. Ronelda Kamfer, Nathan Trantraal, Lynthia Julius en Ryan Pedro in die Afrikaanse literêre sisteem: ’n Metatekstuele ondersoek na beeldvorming. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/c1ab402d-d758-4bee-9905-334298025a86ENGLISH ABSTRACT: The dawn of the third millennium announced the beginning of a new age for Afrikaans literature. High expectations were set for the “democratisation”, “transformation” or “renewal” of the Afrikaans literary tradition in a changing South African and global society. Afrikaans literature had to be repositioned and reimagined. A survey of the Afrikaans poetry debuts and follow-up publications that were published up until the second decade in the third millennium indicates signs of a new generation of Afrikaans poets that are positioning themselves in and towards the Afrikaans literary tradition in new ways. This survey shows a marked presence of specifically young black/coloured Afrikaans poets – significant given the historic context of the institutional exclusion of black/coloured Afrikaans authors from the Afrikaans literary canon. Although this increase in publications by black/coloured Afrikaans poets since the turn of the millennium is an indication of a changing literary system, the positioning of young black/coloured Afrikaans poets in the literary-critical discourse – on the one hand by themselves in their work and in interviews, and on the other hand by literary critics in reviews and other reception texts – indicates tensions in the dynamic between these poets and the Afrikaans literary institution. As a possible barometer of the image of the Afrikaans literature, this qualitative study investigated this dynamic by means of four Afrikaans debut voices that could not pass by the gatekeepers of the Afrikaans literature prior to 2008, namely Ronelda Kamfer (Noudat slapende honde, 2008), Nathan Trantraal (Chokers en survivors, 2013), Lynthia Julius (Uit die kroes, 2020) and Ryan Pedro (Pienk ceramic-hondjies, 2020). In total, 73 texts (consisting of written reviews, written and recorded interviews, and other texts relating to the reception of the four poets’ debuts) that appeared in the period 2008 to 2021 were analysed using ATLAS.ti, a computer-assisted qualitative data analysis software, and discourse analysis in order to gain insight into the trends in the positioning of the four poets by themselves and by literary critics. The primary goal was to describe the image of the Afrikaans literature that exists from this positioning and dynamic in the literary-critical discourse. For the purposes of this study, Gerard Genette’s concept of metatextuality was used to suggest the relationship that exists between various reception texts in the literary-critical discourse. Systems theory (specifically Even-Zohar’s polysystem theory), theories relating to the author’s image and posture, as well as Lefevere’s concept of rewriting were also used as theoretical departure for the study. Based on the analyses of the four case studies, it was concluded that Kamfer, Trantaal, Julius and Pedro make valuable contributions to the renewal of the Afrikaans literary repertoire, especially relating to the presentation of innovative poet models. However, it was concluded that although there is renewal in terms of the material and symbolic production of marginalised voices in the Afrikaans literature, some reception practices, such as the use of certain metaphors, are signs that the literary system has not yet transformed sufficiently. Finally, suggestions are offered for further studies that might supplement the current one.AFRIKAANSE OPSOMMING: Die derde millennium het die begin van ’n nuwe tydvak vir die Afrikaanse letterkunde ingehuldig. Hoë verwagtinge is in hierdie tydperk in literêre kringe gestel vir die “demokratisering”, “transformasie” of “vernuwing” van die Afrikaanse literêre tradisie in ’n veranderende Suid-Afrikaanse en globale samelewing. Die Afrikaanse letterkunde moes herposisioneer en herverbeel word. ’n Bestekopname van die Afrikaanse poësiedebute en -opvolgbundels wat tot en met die tweede dekade in die derde millennium verskyn, toon tekens van ’n nuwe generasie Afrikaanse digters wat hulleself op vernuwende wyses in en teenoor die Afrikaanse literêre tradisie posisioneer. Opvallend uit hierdie bestekopname is die teenwoordigheid van spesifiek jong swart/bruin Afrikaanse digters – veral beskou in die historiese konteks van die institusionele uitsluiting van swart/bruin Afrikaanse skrywers uit die Afrikaanse literêre kanon. Alhoewel die toename in publikasies deur swart/bruin Afrikaanse digters sedert die millenniumwisseling ’n aanduiding van ’n veranderende literêre sisteem is, dui die posisionering van jong swart/bruin Afrikaanse digters in die literêr-kritiese diskoers – enersyds deur hulleself in hulle werk en in onderhoude, en andersyds deur literêre kritici in resensies en ander resepsietekste – op ’n spanningsvolle dinamiek tussen dié digters en die Afrikaanse literêre institusie. As moontlike barometer van die beeld van die Afrikaanse letterkunde ondersoek hierdie kwalitatiewe studie dié dinamiek aan die hand van vier Afrikaanse debuutdigterstemme wat voor 2008 nie deur die hekwagters van die Afrikaanse letterkunde kon dring nie, naamlik Ronelda Kamfer (Noudatslapende honde, 2008), Nathan Trantraal (Chokers en survivors, 2013), Lynthia Julius (Uit die kroes, 2020) en Ryan Pedro (Pienk ceramic-hondjies, 2020). Altesaam 73 resepsietekste (bestaande uit geskrewe resensies, geskrewe en opgeneemde onderhoude, en ander tekste relevant tot die resepsie van die vier digters se debute) wat in die tydperk 2008 tot 2021 verskyn het, is met behulp van ATLAS.ti, die rekenaargesteunde kwalitatiewe dataontledingsagteware, en diskoersontleding ontleed ten einde insig te verkry in die tendense in die posisionering van die vier digters deur hulleself en deur literêre kritici. Die primêre doel was om die beeld van die Afrikaanse letterkunde wat vanuit hierdie posisionering en dinamika in die literêr-kritiese diskoers ontstaan, te beskryf. Vir die doeleindes van hierdie studie is Gerard Genette se konsep van metatekstualiteit benut om die verhouding tussen verskeie resepsietekste in die literêr-kritiese diskoers voor te stel. Sisteemteorie (spesifiek Even-Zohar se polisisteemteorie), asook beeldvorming- en postuurteorieë en Lefevere se konsep van herskrywing is ook in die studie as teoretiese vertrekpunte benut. Na aanleiding van die ontleding van die vier gevallestudies is bevind dat Kamfer, Trantaal, Julius en Pedro waardevolle bydraes tot die vernuwing van die Afrikaanse literêre repertorium lewer, veral wat betref die aanbied van vernuwende digtersmodelle. Daar is egter tot die gevolgtrekking gekom dat, alhoewel daar sedert 2008 vernuwing met betrekking tot die materiële en simboliese produksie van gemarginaliseerde stemme in die Afrikaanse letterkunde is, sekere resepsiepraktyke, soos die gebruik van bepaalde metafore, steeds dui op ’n literêre sisteem wat nog nie genoegsaam getransformeer het nie. Die studie sluit af met voorstelle vir verdere studies wat die huidige kan aanvul.Master
Does the current traffic impact assessment process followed in South Africa encourage unsustainable transport planning?
Get PDFNeethling, L. 2025. Does the Current Traffic Impact Assessment Process Followed in South Africa Encourage Unsustainable Transport Planning?. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/c3aea0d3-4265-4d8c-9ff8-6e6939c51209Thesis (MEng)--Stellenbosch University, 2025.ENGLISH ABSTRACT: Traffic Impact Assessments (TIAs) are used to determine the impact that new developments or changes in land use zoning would have on the surrounding road network. These assessments play a key role in urban planning and assist in predicting future transport needs. All TIAs in South Africa must be done in line with the national TIA guidelines published by the Committee of Transport Officials. TIA guidelines have the ability to ensure that sustainable transport planning takes place. The aim of this research was to assess whether the current TIA framework in South Africa promotes unsustainable transport planning. While the South African TIA guidelines include requirements for various transport modes, they emphasise private vehicle use and the impacts that private vehicles would have on the road network. This focus on private vehicles allows TIAs to neglect public transport and non-motorised transport (NMT). These sustainable transport modes are essential for many South Africans in their daily travels. This research compared TIA guidelines from five countries (South Africa, New Zealand, the United Arab Emirates, the United Kingdom and the United States of America) to determine the level of sustainable transport planning required in their TIAs. All guidelines address various transport modes, however the main focus of the TIAs varied. The South African TIA guidelines resembled those of the United Arab Emirates and the United States of America. These guidelines are focussed on the use of private vehicles. In contrast, the TIA guidelines of New Zealand and the United Kingdom incorporate more sustainable transport alongside private vehicle use. A case study of five gated suburban developments was then conducted to evaluate the practical implementation of the South African TIA guidelines. All TIAs adhered to the South African TIA guidelines and focussed on private vehicles use by residents. Most of the information in the TIAs directly related to private vehicle use, accesses, parking and road infrastructure. Minimal attention was given to alternative sustainable transport modes or facilities. Thus, confirming that the South African TIA process promotes private vehicle use and reinforces the view of private vehicles as a necessity in urban planning. The opinions of traffic engineers were sought through a survey to evaluate the implementation and sustainability of South Africa’s current TIA process. It was evident that most transport practitioners agree that the TIA guidelines promote the use of private vehicles and do not require adequate assessment of sustainable transport modes. However, transport practitioners believe that focusing on sustainable transport in South Africa is feasible. Thus, illustrating that despite existing challenges, incorporating more sustainable transport strategies in the South African TIA process would be practical and beneficial.AFRIKAANSE OPSOMMING: Verkeersimpakassesserings (VIAs) word gebruik om die impak te bepaal wat nuwe ontwikkelinge of veranderinge in grondgebruiksonering op die omliggende padnetwerk sal hê. Hierdie assesserings speel ‘n sleutelrol in stedelike beplanning en help om toekomstige vervoerbehoeftes te voorspel. Alle VIAs in Suid-Afrika moet gedoen word in ooreenstemming met die nasionale VIA-riglyne wat deur die Komitee van Vervoerbeamptes gepubliseer is. VIA-riglyne het die vermoë om te verseker dat volhoubare vervoerbeplanning plaasvind. Die doel van hierdie navorsing was om te bepaal of die huidige VIA-raamwerk in SuidAfrika onvolhoubare vervoerbeplanning bevorder. Hoewel die Suid-Afrikaanse VIAriglyne vereistes vir verskeie vervoermetodes insluit, beklemtoon dit die gebruik van privaatvoertuie en die impak wat privaatvoertuie op die padnetwerk sal hê. Hierdie fokus op privaatvoertuie stel VIAs in staat om openbare vervoer en nie-gemotoriseerde vervoer te verwaarloos. Hierdie volhoubare vervoermetodes is noodsaaklik vir baie Suid-Afrikaners in hul daaglikse reise. Hierdie navorsing het VIA-riglyne van vyf lande (Suid-Afrika, Nieu-Seeland, die Verenigde Arabiese Emirate, die Verenigde Koninkryk en die Verenigde State van Amerika) vergelyk om die vlak van volhoubare vervoerbeplanning wat in hul VIAs vereis word, te bepaal. Alle riglyne spreek verskeie vervoermetodes aan, maar die hooffokus van die VIA’s het egter gewissel. Die Suid-Afrikaanse VIA-riglyne het met dié van die Verenigde Arabiese Emirate en die Verenigde State van Amerika ooreengekom. Hierdie riglyne is gefokus op die gebruik van privaatvoertuie. Daarteenoor het die VIA-riglyne van Nieu-Seeland en die Verenigde Koninkryk meer volhoubare vervoer saam met privaat voertuiggebruik in te sluit. ‘n Gevallestudie van vyf omheinde voorstedelike ontwikkelinge was toe gedoen om die praktiese implementering van die Suid-Afrikaanse VIA-riglyne te evalueer. Alle VIAs het die Suid-Afrikaanse VIA-riglyne nagekom en gefokus op die gebruik van privaatvoertuie wat deur inwoners. Die meeste van die inligting in die VIAs hou direk verband met privaat voertuiggebruik, toegange, parkering en padinfrastruktuur. Minimale aandag is gegee aan alternatiewe volhoubare vervoermetodes of fasiliteite. Dit bevestig dus dat die Suid-Afrikaanse VIA-proses die gebruik van privaatvoertuie bevorder en die siening van privaatvoertuie as ‘n noodsaaklikheid in stedelike beplanning versterk. Die menings van verkeersingenieurs was ingewin duer ‘n opname om die implementering en volhoubaarheid van Suid-Afrika se huidige VIA-proses te evalueer. Dit was duidelik dat die meeste verkeerspraktisyne saamstem dat die VIA-riglyne die gebruik van privaatvoertuie bevorder en nie voldoende assessering van volhoubare vervoermetodes vereis nie. Verkeerspraktisyne glo egter dat die haalbaar is om op volhoubare vervoer in Suid-Afrika te fokus. Dit illustreet dus dat ten spyte van bestaande uitdagings, die inkorporering van meer volhoubare vervoerstrategieë in die SuidAfrikaanse VIA-proses prakties en voordelig sal wees
Assessing the adoptability of limestone calcined clay cement (lc3) in slab-like elements
Get PDFCITATION: Abdrafiu, I.M. 2025. Assessing the Adoptability of Limestone Calcined Clay Cement (LC3) in Slab-like Elements. Unpublished masters thesis. Stellenbosch: Stellenbosch Univeristy [online]. Available: https://scholar.sun.ac.za/handle/10019.1/131995Thesis (MEng)--Stellenbosch University, 2025.ENGLISH ABSTRACT: The cement production industry significantly contributes to global CO2 emissions and consequently, to global warming. Replacing conventional Portland cement with limestone calcined clay cement (LC3) has been identified as a key strategy for reducing the environmental impact of the construction industry. However, the construction industry is laggard in adopting innovative technologies and materials, especially with cement and concrete. Lack of trust and in-depth information on the handling and potential defects associated with such materials contribute to this laggardness. This research aims to holistically investigate the fresh properties, mechanical properties and plastic shrinkage cracking of LC3 from the perspective of a concrete floor contractor who is interested in its use. CEM I was partially replaced with 30%, 45%, and 60% of commercially produced limestone and calcined clay (LC2) blend in concrete mixes to produce LC3 concrete. The flowability, rheology and fresh density of these mixes were evaluated, and their compressive and flexural performance were compared to the control. Plastic shrinkage cracking in the mixes was also examined under extreme and normal climatic conditions. Furthermore, the influence of superplasticiser on the LC3 concrete properties was investigated. Results indicate that with 30% LC2 replacement in CEM I, the flowability of the mix decreased by approximately 41%, the yield stresses (static and dynamic) were more than double, while the fresh density remained similar. The compressive strength of the LC3 concrete at 30% LC2 replacement in CEM I is comparable to the control at 7 days but has a lower strength gain at 28 and 90 days, while LC3 concrete shows higher flexural strength gain over time compared to the control. Plastic shrinkage cracking in LC3 concrete containing 30% LC2 is more than twice that of the control, with cracking intensifying with increasing LC2 content in the mix. The addition of a moderate quantity of superplasticiser to the LC3 mixes significantly improved the flowability and rheology of the mix, while the fresh density (mix containing 30% LC2 and 0.35% superplasticiser) was reduced by about 3%. Regarding mechanical performance, the addition of superplasticiser led to about 3 MPa reduction in the compressive strength at 28 days across all percentage replacements, while no notable impact on the flexural strength of LC3 concrete was recorded. In mixes which required a higher dosage of superplasticiser (0.5% and 0.65%), plastic shrinkage cracking was reduced by about 30%. In conclusion, to promote the adoptability of LC3 concrete, moderate use of polycarboxylate ether-based superplasticiser can effectively modify the rheological properties of the LC3 mixes. A replacement of up to 30% CEM I with LC2 appears suitable to achieve comparable mechanical performance to Portland cement. However, additional preventive measures are necessary to mitigate plastic shrinkage cracking, particularly in extreme climate conditions.AFRIKAANSE OPSOMMING: Die sementvervaardigingsbedryf is 'n groot bydraer tot die probleem van aardverwarming. Daarom is die vervanging van die konvensionele Portland-sement met kalksteen-gekalsineerde klei-sement (LC3) geïdentifiseer as 'n belangrike strategie om aardverwarming binne die konteks van die konstruksiesektor af te weer. Die konstruksiebedryf is egter bekend daarvoor dat dit stadig is om innoverende tegnologieë en materiale aan te neem, veral met betrekking tot sement en beton. 'n Gebrek aan vertroue en in-diepte inligting met betrekking tot die hantering en moontlike gebreke wat geassosieer word met die gebruik van sulke materiale is een van die redes vir hierdie traagheid. Daarom fokus hierdie navorsing op 'n holistiese ondersoek van die vars eienskappe, meganiese prestasie en plastiese krimpkrake wat geassosieer word met die gebruik van LC3 vanuit die perspektief van 'n betonvloerkontrakteur wat belangstel om LC3 te gebruik. CEM I is vervang met 30%, 45% en 60% van kommersieel vervaardigde kalksteen en gekalsineerde klei (LC2) mengsel in 'n betonmengsel. Die werkbaarheid, reologie en varsdigtheid van die mengsels is eerstens geëvalueer, die druk- en buigprestasie van LC3-betonmengsels is vergelyk met Portland-sementbeton, terwyl die plastiese krimp, plastiese versakking en plastiese krimpkrake van die mengsels ondersoek is met inagneming van ’n uiterste en gematige klimaat. Die invloed van superplastiseermiddel op die LC3-beton is ook ondersoek. Resultate toon dat, met die byvoeging van 30% van die LC2-mengsel, die druksterkte van die LC3-beton vergelykbaar is met die konvensionele beton na 7 dae, maar effens laer is by latere ouderdomme, terwyl die buigsterkte oor alle persentasievervangings en kuurouderdomme afgeneem het. Daarbenewens is die plastiese krimpkrake in LC3-beton wat 30% van LC2-mengsel bevat, sowat dubbel die kontrole. Die plastiese krimpkrake het toegeneem met stygende LC2-inhoud in die mengsels. Met betrekking tot die invloed van superplastiseermiddel, is 'n effense vermindering in die druksterkte van LC3-mengsels wat superplastiseermiddel bevat waargeneem in vergelyking met die sonder superplastiseermiddel, terwyl geen noemenswaardige impak van superplastiseermiddel op die buigsterkte van LC3-beton aangeteken is nie. Die plastiese krimpkrake in die LC3-mengsels is aansienlik verminder, veral met hoër superplastiseermiddel-dosisse (0.5% en 0.65%). Dus, om 'n vergelykbare sterkte met Portland-sement te bereik, is tot 30% vervanging geskik gevind, maar verhoogde voorkomingsmaatreëls moet ingestel word met betrekking tot plastiese krimpkrake, veral in uiterste klimaatstreke.Master
GPAbin to unify principal component analysis biplots from multiple imputations
Get PDFThesis (MCom)--Stellenbosch University, 2025.Ramaisa, M. 2025. GPAbin to unify principal component analysis biplots from multiple imputations. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/d0c890f4-f178-403e-9e1d-1dfca4ba441aENGLISH SUMMARY: Missing data in real world applications are frequently encountered by data practitioners. The strategy to handle missing data is often deletion which results in loss of information and biased results in analyses. It is important to investigate the underlying reason for missingness to decide on an appropriate handling strategy to reduce bias. Multiple imputation is a superior technique to handle missing values, in which multiple possible values for missing data are imputed, resulting in multiple completed data sets. A practitioner may be interested in exploratory data analysis through visualisation, however interpreting and analysing multiple visualisations of completed data sets may lead to subjective bias and may be time intensive. GPAbin has been developed to unify multiple completed multivariate categorical data visualisations, specifically multiple correspondence analysis biplots. This has been achieved using generalised orthogonal Procrustes analysis and Rubin's rules to result in a single unbiased visualisation for practitioners. The extension of the GPAbin methodology to continuous completed data sets is presented in this project. This is achieved by utilising the extension of the classic Gabriel principal component analysis biplot as a starting point. A simulation study is presented to further understand the performance of the newly developed methodology.AFRIKAANSE OPSOMMING: Ontbrekende data work gereeld deur data-praktisyns teegekom in toegepaste probleme. Die strategie om ontbrekende data te hanteer is dikwels weglating, wat lei tot verlies van inligting en sydigheid in ontledings. Dit is belangrik om die onderliggende rede vir ontbreking te ondersoek om te besluit op 'n toepaslike analise strategie om sydigheid te verminder. Meervoudige imputasie, waarin verskeie moontlike waardes vir ontbrekende data imputasie word, is 'n meer gepaste tegniek om ontbrekende waardes te hanteer wat lei tot meervoudige voltooide datastelle. 'n Praktisyn kan belangstel in verkennende data-analise deur middel van visualisering, maar die interpretasie en ontleding van verskeie visualiserings van voltooide datastelle mag lei tot subjektiewe sydigheid en kan tydsintensief wees. GPAbin is ontwikkel om meervoudige voltooide meerveranderlike kategoriese datavisualiserings, spesifiek meervoudige ooreenkomsanalise bi-stippings te verenig. Dit is bereik deur veralgemeende ortogonale Procrustes-analise en Rubin se reels te gebruik om 'n enkele onsydige visualisering vir praktisyns tot gevolg te he. Die uitbreiding van die GPAbin metodologie tot kontinue voltooide datastelle word in hierdie projek aangebied. Dit word bereik deur die uitbreiding van die klassieke Gabriel-hoofkomponent-analise bi stipping as 'n beginpunt te gebruik. 'n Simulasiestudie word aangebied om die sukses van die nuutontwikkelde metodologie beter te verstaan.Master
Love, learning, and identity at New Hope: a critical ethnographic study of how young coloured men construct and perform race, masculinity, and sexuality at a Northern Cape High School
Get PDFThesis (PhD)--Stellenbosch University, 2025.Makhetha, T. 2025. Love, Learning, and Identity at New Hope: A Critical Ethnographic Study of how Young Coloured Men Construct and Perform Race, Masculinity, and Sexuality at a Northern Cape High School. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/d1814024-781f-4e98-98c3-f01533880fdfENGLISH ABSTRACT: This dissertation discusses sixteen young Coloured men’s lives in ways that document in equal measure their failures, suffering, and pain, as well as their victories, pleasures, joys, and how they love. In doing so, I aim to grapple more comprehensively with their complex lives, interpret their behaviours in more nuanced ways, and provide practitioners and researchers working with young men with deeper insights to inform policy, practice, and interventions. This is done without being naïve to the reality that versions of the masculinities available to young Coloured men featured in this study may promote and condone misogyny, homophobia, and violence. Still, this work is crucial at a juncture where boys and men are habitually implicated in gender-based violence, coercive and unsafe sexual practices, and problematic notions of manhood. The corpus of academic scholarship engaging with the harm men inflict on themselves and others suggests that reaching men in their youth may have a lasting impact in reducing the propensity for such behaviour, and may create more egalitarian social relations. My academic, activist, and professional work, which in many ways inspired this study, is in service of this ideal.
The young men I reflect on in this dissertation are creative and resilient individuals who have a deep awareness of their social worlds. I demonstrate how their behaviours and actions, including those that are harmful to themselves and others, are in part shaped by prevailing social norms and by their peers. I theorise the dynamic encounters between my participants, other boys and young men, girls and young women, and teachers – who I call the audience – in different social settings and in different temporal moments, as carefully crafted acts or performances to create specific impressions about themselves. In the same way, I contend that to reveal the nuances, contradictions, and complexities of these young Coloured men’s performances, one must critically reflect on how racialised economic inequalities and racial separation structure social life in this small town, in the Northern Cape Province, South Africa. The data presented in this dissertation are based on a 13-month-long ethnographic study conducted between June 2014 and July 2015. All procedural and situated ethical considerations were adhered to and ethical clearance was granted by the Faculty of Arts and Social Science at Stellenbosch University. The findings of this study show that young Coloured men actively negotiate, conform to, and resist the prevailing social norms or grand narratives in the town and the school. Moreover, the findings suggest that participants' performances are influenced by their peers' verbal and non-verbal cues and expressions. I demonstrate how performances were either welcomed and celebrated through agreement, laughter, and bodily expressions, or rejected through silence, cajoling, and othering. This, in turn, led to adjustments or exaggerations of acts informed by the audience’s reactions. The audience was actively engaged in the performance, rather than being observers or consumers of these acts. Unlike Goffman (1959) who foregrounds the role of the actor and the performance, I argue that the audience is as critical in shaping the performance as the actor and the prevailing grand narratives or scripts are. To this end, I contend that social identities are co-produced through a dynamic engagement I term Audiensciousness: the keen awareness and involvement of actors and audiences in the performance and the production of social identities and the social meanings attached to these.AFRIKAANSE OPSOMMING: Hierdie proefskrif bespreek sestien jong Kleurlingmans se lewens op maniere wat in gelyke mate hul mislukkings, lyding en pyn dokumenteer, sowel as hul oorwinnings, plesier, vreugdes en hoe hulle liefhet. Sodoende beoog ek om meer omvattend met hul komplekse lewens te worstel, hul gedrag op meer genuanseerde maniere te interpreteer en praktisyns en navorsers wat met jong mans werk, dieper insigte te bied om beleid, praktyk en intervensies in te lig. Dit word gedoen sonder om naïef te wees vir die realiteit dat weergawes van die manlikheid wat beskikbaar is vir jong bruin mans wat in hierdie studie verskyn, vrouehaat, homofobie en geweld kan bevorder en goedpraat. Tog is hierdie werk van kardinale belang op 'n tydstip waar seuns en mans gewoonlik betrokke is by geslagsgebaseerde geweld, dwang en onveilige seksuele praktyke, en problematiese idees van manlikheid. Die korpus van akademiese wetenskap wat betrokke is by die skade wat mans hulself en ander berokken, dui daarop dat die bereiking van mans in hul jeug 'n blywende impak kan hê om die geneigdheid tot sulke gedrag te verminder, en meer egalitêre sosiale verhoudings kan skep. My akademiese, aktivistiese en professionele werk, wat in baie opsigte hierdie studie geïnspireer het, staan in diens van hierdie ideaal. Die jong mans oor wie ek in hierdie proefskrif reflekteer, is kreatiewe en veerkragtige individue wat 'n diep bewustheid van hul sosiale wêrelde het. Ek demonstreer hoe hul gedrag en optrede, insluitend dié wat skadelik vir hulself en ander is, deels gevorm word deur heersende sosiale norme en deur hul eweknieë. Ek teoretiseer die dinamiese ontmoetings tussen my deelnemers, ander seuns en jong mans, meisies en jong vroue, en onderwysers – wat ek die gehoor noem – in verskillende sosiale omgewings en in verskillende tydelike oomblikke, as noukeurig vervaardigde handelinge of optredes om spesifieke indrukke te skep oor hulself. Op dieselfde manier voer ek aan dat om die nuanses, teenstrydighede en kompleksiteite van hierdie jong Kleurlingmans se vertonings te openbaar, 'n mens krities moet besin oor hoe gerasseerde ekonomiese ongelykhede en rasseskeiding die sosiale lewe in hierdie klein Noord-Kaapse dorpie struktureer. Die data wat in hierdie proefskrif aangebied word, is gebaseer op 'n 13 maande lange etnografiese studie wat tussen Junie 2014 en Julie 2015 gedoen is. Alle prosedurele en geleë etiese oorwegings is nagekom en etiese klaring is deur die Fakulteit Lettere en Sosiale Wetenskappe aan die Universiteit Stellenbosch verleen. Die bevindinge van hierdie studie toon dat jong bruin mans aktief onderhandel, voldoen aan, en die heersende sosiale norme of groot narratiewe in die dorp en die skool weerstaan. Verder dui die bevindinge daarop dat deelnemers se prestasies beïnvloed word deur hul maats se verbale en nie-verbale leidrade en uitdrukkings. Ek demonstreer hoe optredes óf verwelkom en gevier is deur ooreenkoms, lag en liggaamlike uitdrukkings, óf verwerp is deur stilswye, geskreeu en andersyds. Dit het op sy beurt gelei tot aanpassings of oordrywings van dade wat deur die gehoor se reaksies ingelig is. Die gehoor was aktief betrokke by die opvoering, eerder as om waarnemers of verbruikers van hierdie optredes te wees. Anders as Goffman (1959) wat die rol van die akteur en die vertoning op die voorgrond stel, argumenteer ek dat die gehoor net so krities is in die vorming van die opvoering as wat die akteur en die heersende groot narratiewe of draaiboeke is. Vir hierdie doel voer ek aan dat sosiale identiteite mede-geproduseer word deur 'n dinamiese betrokkenheid wat ek noem Audiensciousness: die skerp bewustheid en betrokkenheid van akteurs en gehore by die opvoering en die produksie van sosiale identiteite en die sosiale betekenisse wat daaraan gekoppel word.Doctora
How do South African women journalists perceive the influence of online information disorder campaigns on their journalistic practices?
Get PDFThesis (MA)--Stellenbosch University, 2025.Zwane-Siguqa, B. M. 2025. How do South African women journalists perceive the influence of online information disorder campaigns on their journalistic practices? Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/d7576fc5-3eee-442a-b41d-9aa6c5e08bf7ENGLISH ABSTRACT: Similar to their counterparts in the Global North, women journalists in the Global South face numerous online information disorder campaigns directed at them, predominantly because of their gender. There is, however, disproportionately less academic research on the effects of information disorder campaigns in the Global South. This study highlights and contributes positively to this growing necessity. It investigates the perceptions of South African women journalists about information disorder campaigns against them, as well as these campaigns’ impact on their journalistic practices. The research is grounded in intersectional feminist theory. Using purposive sampling, TA, and CA methods and techniques, the researcher analysed semi-structured interviews with 10 South African women journalists engaged in political and current affairs reporting, alongside a CA of their activities on social media platforms X (formerly Twitter), Facebook and Instagram. The findings reveal varying levels of information disorder campaigns targeted at these journalists, not solely due to their profession but also specifically because of their gender. Multiple forms of gender-targeted information disorder campaigns against these women journalists are identified, and the research findings demonstrate that the information disorder campaigns against South African women journalists are entrenched in cyber misogyny with strong racial undertones. Additionally, the study examines how information disorder o^en shapes the productivity of women journalists and how, in some instances, it even hinders their work. It also describes the various coping mechanisms and self-management techniques these women journalists employ to effectively practise their craft. The study motivates for a multi-stakeholder approach to combating information disorder in South Africa and makes recommendations to media organisations, government, politicians, and civil society on how they can collaborate for future action.AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar nie.Master
Towards business ethics teaching that enables moral development and behaviour
Get PDFRossouw, Nina. 2025. Towards business ethics teaching that enables moral development and behaviour. Unpublished masters thesis. Stellenbosch: Stellenbosch Univeristy [online]. Available: https://scholar.sun.ac.za/handle/10019.1/132454Thesis (MPhil)--Stellenbosch University, 2025.ENGLISH ABSTRACT: Business ethics, and the teaching thereof, has been a contested and deliberated topic. Whether ethics can be taught, how it should be taught, and the aims of such teaching have been some of the questions considered in literature. Furthermore, business ethics sits against the backdrop of corporate failures that happen too often (normally partially as a result of ethics failures). The necessary question to consider is how we can use the teaching of business ethics to affect behavioural change? This thesis argues for a teaching approach to business ethics that incorporates moral development, as moral development could ultimately lead to changed (moral) behaviour. Kohlberg’s theory of moral development confirms that moral development can take place during the lifespan of a person, and further confirms that education can foster this development. Considering the aims of education, and business ethics specifically, teaching (and education) is always a moral undertaking, and education inevitably influence students’ ways of thinking and being. Three teaching frameworks that enable moral development guide the approach forwarded in this thesis on how to teach business ethics. The various frameworks have never been considered as a combined pedagogical approach. This thesis argues that the relevance of the consideration of the frameworks is in their synergy, and how they work together. All of the frameworks enable a different aspect of (eventual) ethical action. The thesis contributes to the field of business ethics teaching by suggesting an appropriate pedagogical approach to teach business ethics to enable moral development and behaviour and furthermore provides guidelines in terms of a teaching framework to do so.AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar.Master
Sensorless control of dual three-phase permanent magnet vernier machine for ship propulsion
Get PDFTeymoori, V. 2025. Sensorless Control of Dual Three-Phase Permanent Magnet Vernier Machine for Ship Propulsion. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/da2adfd7-10f9-488f-8342-7277554c9aeaThesis (PhD)--Stellenbosch University, 2025.ENGLISH ABSTRACT: Permanent magnet (PM) synchronous machines are extensively utilized across various industrial sectors due to their significant advantages, including high efficiency, superior power density, and rapid dynamic response. These features have made PMSMs a preferred choice for many applications, particularly as industries increasingly prioritize environmental sustainability. One notable trend is the growing adoption of PMSMs in ship propulsion systems, driven by the global push towards greener technologies and reduced emissions. In parallel, the past few decades have seen a surge of interest in multiphase machines, which offer several inherent benefits. These include reduced torque ripple, enhanced power distribution capabilities, and greater fault tolerance compared to traditional three-phase machines. Recent advances in science and technology have only bolstered the case for multiphase machines, positioning them as a key solution for future applications. Researchers are actively exploring their potential in fields such as electric vehicles (EVs), railway traction, all-electric ships, more-electric aircraft, and wind power generation systems, among others. For optimal control performance in PMSM systems, particularly in vector control and direct torque control applications, precise information about the rotor’s position is crucial. Traditionally, encoders have been employed to gather this data. However, high-precision position sensors can be expensive, and ship propulsion systems often operate in harsh environments characterized by extreme pressure, humidity, and vibration. Under such conditions, conventional mechanical encoders may malfunction or fail entirely. This has led to a growing interest in sensorless control algorithms, which are rapidly evolving and offer a more robust solution for these challenging environments. This research follows a structured approach, beginning with the development of an observer for standard PMSMs, which is then enhanced and adapted for Vernier machines, and finally extended to Dual Three-Phase Vernier Machines with a specific emphasis on ship propulsion applications. The objective is to evaluate and select the most suitable control technique to ensure efficient and reliable operation in marine environments, pushing forward advancements in sensorless control strategies for next-generation propulsion systems.AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar.Doctora
Conceptual design of an impulse turbine and gas generator for a rocket engine turbopump
Get PDFSchneider, M. D. 2025. Conceptual Design of an Impulse Turbine and Gas Generator for a Rocket Engine Turbopump. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/da903599-6e5f-488d-ab0d-52814d882653Thesis (MEng)--Stellenbosch University, 2025.ENGLISH ABSTRACT: This thesis presents a conceptual design and validation of an impulse turbine and gas generator for a turbopump-fed rocket engine, currently under development by the Aerospace Systems Research Institute (ASRI). With the recent growth in the private space sector and the rise of "NewSpace" companies, the demand for efficient, domestically produced launch systems has increased. South Africa, with a growing satellite industry, but limited launch capabilities, stands to benefit greatly from a domestic launch platform. The goal of this study is to establish foundational design methodologies for a gas generator and impulse turbine, enabling local advancements in rocket propulsion and contributing to the development of South Africa’s First Integrated Rocket Engine (SAFFIRE). A design methodology for a supersonic, partial admission impulse turbine is presented. This methodology was validated through numerical simulation of a baseline design, confirming the performance of the design under operating conditions. A gas generator design methodology was defined to provide an initial conceptual framework for the SAFFIRE gas generator configuration. This methodology, grounded in an extensive literature review, did not incorporate simulation-based analysis. Key interdependencies between the gas generator and turbine were identified, highlighting how these systems interact and influence each other’s performance. This project’s findings serve as a valuable reference for future work within ASRI. The study provides a preliminary roadmap for the development of gas generators and impulse turbines locally, paving the way for further refinement, manufacturing, and experimental testing of these components.AFRIKAANSE OPSOMMING: Hierdie proefskif handel oor die konsepontwerp en validasie van ’n impulsturbine en gas-generator vir ’n vuurpylenjin wat deur ’n turbopomp gevoer word. Die enjin word tans ontwikkel deur ASRI (Aerospace Systems Research Institute). Gegewe die onlangse groei in die private ruimtesektor en die opkoms van "NewSpace" maatskappye, het die vraag na doeltreffende, plaaslik vervaardigde lanseerstelsels toegeneem. Suid-Afrika, met ’n groeiende satellietbedryf, maar beperkte lanseervermoëns, sal baie baat vind by ’n plaaslike lanseerplatform. Die doel van hierdie studie is om basiese ontwerpsmetodologieë vas te stel vir ’n gas-generator en impulsturbine, wat plaaslike vooruitgang in vuurpyl ontwikkeling moontlik sal maak en sal bydra tot die ontwikkeling van die SAFFIRE enjin. ’n Ontwerpmetodologie vir ’n supersoniese, gedeeltelikeinlaat impulsturbine word verduidelik. Hierdie metodologie is deur ’n numeriese simulasie van die basisontwerp, wat die prestasie van die ontwerp onder bedryfstoestande verteenwoordig, bevistig. ’n Gas-generator ontwerpsmetodologie is ook gedefinieer. Die metode verskaf ’n aanvanklike konsepraamwerk vir die SAFFIRE gas-generator. Belangrike verwantskappe tussen die gas-generator en turbine is geïdentifiseer, wat beklemtoon hoe die komponente se prestasie deur stelsel-interaksie beïnvloed word. Hierdie projek se bevindinge dien as ’n verwysing vir toekomstige werk binne ASRI. Die studie verskaf ’n voorlopige padkaart vir die ontwikkeling van plaaslike gas-generators en impulsturbines, wat die weg baan vir verdere verfyning, vervaardiging en eksperimentele evaluasie van hierdie komponente.Master